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d7429b6a | 1 | /* Data flow analysis for GNU compiler. |
c9bacfdb | 2 | Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, |
21c7361e | 3 | 1999, 2000, 2001 Free Software Foundation, Inc. |
d7429b6a RK |
4 | |
5 | This file is part of GNU CC. | |
6 | ||
7 | GNU CC is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GNU CC is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GNU CC; see the file COPYING. If not, write to | |
a35311b0 RK |
19 | the Free Software Foundation, 59 Temple Place - Suite 330, |
20 | Boston, MA 02111-1307, USA. */ | |
d7429b6a | 21 | |
e881bb1b RH |
22 | /* This file contains the data flow analysis pass of the compiler. It |
23 | computes data flow information which tells combine_instructions | |
24 | which insns to consider combining and controls register allocation. | |
d7429b6a | 25 | |
e881bb1b RH |
26 | Additional data flow information that is too bulky to record is |
27 | generated during the analysis, and is used at that time to create | |
28 | autoincrement and autodecrement addressing. | |
d7429b6a RK |
29 | |
30 | The first step is dividing the function into basic blocks. | |
31 | find_basic_blocks does this. Then life_analysis determines | |
32 | where each register is live and where it is dead. | |
33 | ||
34 | ** find_basic_blocks ** | |
35 | ||
e881bb1b RH |
36 | find_basic_blocks divides the current function's rtl into basic |
37 | blocks and constructs the CFG. The blocks are recorded in the | |
38 | basic_block_info array; the CFG exists in the edge structures | |
39 | referenced by the blocks. | |
d7429b6a | 40 | |
e881bb1b | 41 | find_basic_blocks also finds any unreachable loops and deletes them. |
d7429b6a RK |
42 | |
43 | ** life_analysis ** | |
44 | ||
45 | life_analysis is called immediately after find_basic_blocks. | |
46 | It uses the basic block information to determine where each | |
47 | hard or pseudo register is live. | |
48 | ||
49 | ** live-register info ** | |
50 | ||
51 | The information about where each register is live is in two parts: | |
e881bb1b | 52 | the REG_NOTES of insns, and the vector basic_block->global_live_at_start. |
d7429b6a | 53 | |
e881bb1b RH |
54 | basic_block->global_live_at_start has an element for each basic |
55 | block, and the element is a bit-vector with a bit for each hard or | |
56 | pseudo register. The bit is 1 if the register is live at the | |
57 | beginning of the basic block. | |
d7429b6a | 58 | |
c9bacfdb | 59 | Two types of elements can be added to an insn's REG_NOTES. |
d7429b6a RK |
60 | A REG_DEAD note is added to an insn's REG_NOTES for any register |
61 | that meets both of two conditions: The value in the register is not | |
62 | needed in subsequent insns and the insn does not replace the value in | |
63 | the register (in the case of multi-word hard registers, the value in | |
64 | each register must be replaced by the insn to avoid a REG_DEAD note). | |
65 | ||
66 | In the vast majority of cases, an object in a REG_DEAD note will be | |
67 | used somewhere in the insn. The (rare) exception to this is if an | |
68 | insn uses a multi-word hard register and only some of the registers are | |
69 | needed in subsequent insns. In that case, REG_DEAD notes will be | |
70 | provided for those hard registers that are not subsequently needed. | |
71 | Partial REG_DEAD notes of this type do not occur when an insn sets | |
72 | only some of the hard registers used in such a multi-word operand; | |
73 | omitting REG_DEAD notes for objects stored in an insn is optional and | |
74 | the desire to do so does not justify the complexity of the partial | |
75 | REG_DEAD notes. | |
76 | ||
77 | REG_UNUSED notes are added for each register that is set by the insn | |
78 | but is unused subsequently (if every register set by the insn is unused | |
79 | and the insn does not reference memory or have some other side-effect, | |
80 | the insn is deleted instead). If only part of a multi-word hard | |
81 | register is used in a subsequent insn, REG_UNUSED notes are made for | |
82 | the parts that will not be used. | |
83 | ||
84 | To determine which registers are live after any insn, one can | |
85 | start from the beginning of the basic block and scan insns, noting | |
86 | which registers are set by each insn and which die there. | |
87 | ||
88 | ** Other actions of life_analysis ** | |
89 | ||
90 | life_analysis sets up the LOG_LINKS fields of insns because the | |
91 | information needed to do so is readily available. | |
92 | ||
93 | life_analysis deletes insns whose only effect is to store a value | |
94 | that is never used. | |
95 | ||
96 | life_analysis notices cases where a reference to a register as | |
97 | a memory address can be combined with a preceding or following | |
98 | incrementation or decrementation of the register. The separate | |
99 | instruction to increment or decrement is deleted and the address | |
100 | is changed to a POST_INC or similar rtx. | |
101 | ||
102 | Each time an incrementing or decrementing address is created, | |
103 | a REG_INC element is added to the insn's REG_NOTES list. | |
104 | ||
105 | life_analysis fills in certain vectors containing information about | |
d4b60170 RK |
106 | register usage: REG_N_REFS, REG_N_DEATHS, REG_N_SETS, REG_LIVE_LENGTH, |
107 | REG_N_CALLS_CROSSED and REG_BASIC_BLOCK. | |
fdb8a883 JW |
108 | |
109 | life_analysis sets current_function_sp_is_unchanging if the function | |
110 | doesn't modify the stack pointer. */ | |
e881bb1b | 111 | |
c9bacfdb | 112 | /* TODO: |
e881bb1b RH |
113 | |
114 | Split out from life_analysis: | |
115 | - local property discovery (bb->local_live, bb->local_set) | |
116 | - global property computation | |
117 | - log links creation | |
118 | - pre/post modify transformation | |
119 | */ | |
d7429b6a | 120 | \f |
d7429b6a | 121 | #include "config.h" |
670ee920 | 122 | #include "system.h" |
d3a923ee | 123 | #include "tree.h" |
d7429b6a | 124 | #include "rtl.h" |
6baf1cc8 | 125 | #include "tm_p.h" |
efc9bd41 | 126 | #include "hard-reg-set.h" |
d7429b6a RK |
127 | #include "basic-block.h" |
128 | #include "insn-config.h" | |
129 | #include "regs.h" | |
d7429b6a RK |
130 | #include "flags.h" |
131 | #include "output.h" | |
b384405b | 132 | #include "function.h" |
3d195391 | 133 | #include "except.h" |
2e107e9e | 134 | #include "toplev.h" |
79c9824e | 135 | #include "recog.h" |
11bdd2ae | 136 | #include "expr.h" |
b53978a3 | 137 | #include "ssa.h" |
d7429b6a RK |
138 | |
139 | #include "obstack.h" | |
11ae508b | 140 | #include "splay-tree.h" |
c5c76735 | 141 | |
d7429b6a RK |
142 | #define obstack_chunk_alloc xmalloc |
143 | #define obstack_chunk_free free | |
144 | ||
e881bb1b RH |
145 | /* EXIT_IGNORE_STACK should be nonzero if, when returning from a function, |
146 | the stack pointer does not matter. The value is tested only in | |
147 | functions that have frame pointers. | |
148 | No definition is equivalent to always zero. */ | |
149 | #ifndef EXIT_IGNORE_STACK | |
150 | #define EXIT_IGNORE_STACK 0 | |
151 | #endif | |
152 | ||
d3a923ee RH |
153 | #ifndef HAVE_epilogue |
154 | #define HAVE_epilogue 0 | |
155 | #endif | |
d3a923ee RH |
156 | #ifndef HAVE_prologue |
157 | #define HAVE_prologue 0 | |
158 | #endif | |
0a1c58a2 JL |
159 | #ifndef HAVE_sibcall_epilogue |
160 | #define HAVE_sibcall_epilogue 0 | |
161 | #endif | |
d3a923ee | 162 | |
2a3e384f RH |
163 | #ifndef LOCAL_REGNO |
164 | #define LOCAL_REGNO(REGNO) 0 | |
165 | #endif | |
166 | #ifndef EPILOGUE_USES | |
167 | #define EPILOGUE_USES(REGNO) 0 | |
168 | #endif | |
169 | ||
7e6d8ba1 AH |
170 | #ifdef HAVE_conditional_execution |
171 | #ifndef REVERSE_CONDEXEC_PREDICATES_P | |
172 | #define REVERSE_CONDEXEC_PREDICATES_P(x, y) ((x) == reverse_condition (y)) | |
173 | #endif | |
174 | #endif | |
175 | ||
1f8f4a0b | 176 | /* The obstack on which the flow graph components are allocated. */ |
7eb136d6 | 177 | |
1f8f4a0b MM |
178 | struct obstack flow_obstack; |
179 | static char *flow_firstobj; | |
7eb136d6 | 180 | |
e881bb1b | 181 | /* Number of basic blocks in the current function. */ |
d7429b6a | 182 | |
e881bb1b | 183 | int n_basic_blocks; |
d7429b6a | 184 | |
d3a923ee RH |
185 | /* Number of edges in the current function. */ |
186 | ||
187 | int n_edges; | |
188 | ||
e881bb1b | 189 | /* The basic block array. */ |
d7429b6a | 190 | |
e881bb1b | 191 | varray_type basic_block_info; |
d7429b6a | 192 | |
e881bb1b | 193 | /* The special entry and exit blocks. */ |
d7429b6a | 194 | |
d4b60170 RK |
195 | struct basic_block_def entry_exit_blocks[2] |
196 | = {{NULL, /* head */ | |
e881bb1b RH |
197 | NULL, /* end */ |
198 | NULL, /* pred */ | |
199 | NULL, /* succ */ | |
200 | NULL, /* local_set */ | |
7dfc0fbe | 201 | NULL, /* cond_local_set */ |
e881bb1b RH |
202 | NULL, /* global_live_at_start */ |
203 | NULL, /* global_live_at_end */ | |
204 | NULL, /* aux */ | |
205 | ENTRY_BLOCK, /* index */ | |
336a6399 | 206 | 0, /* loop_depth */ |
51891abe | 207 | 0 /* count */ |
e881bb1b RH |
208 | }, |
209 | { | |
210 | NULL, /* head */ | |
211 | NULL, /* end */ | |
212 | NULL, /* pred */ | |
213 | NULL, /* succ */ | |
214 | NULL, /* local_set */ | |
7dfc0fbe | 215 | NULL, /* cond_local_set */ |
e881bb1b RH |
216 | NULL, /* global_live_at_start */ |
217 | NULL, /* global_live_at_end */ | |
218 | NULL, /* aux */ | |
219 | EXIT_BLOCK, /* index */ | |
336a6399 | 220 | 0, /* loop_depth */ |
51891abe | 221 | 0 /* count */ |
e881bb1b RH |
222 | } |
223 | }; | |
d7429b6a | 224 | |
56744d1a JL |
225 | /* Nonzero if the second flow pass has completed. */ |
226 | int flow2_completed; | |
227 | ||
d7429b6a RK |
228 | /* Maximum register number used in this function, plus one. */ |
229 | ||
230 | int max_regno; | |
231 | ||
b1f21e0a | 232 | /* Indexed by n, giving various register information */ |
d7429b6a | 233 | |
6feacd09 | 234 | varray_type reg_n_info; |
d7429b6a | 235 | |
d7429b6a RK |
236 | /* Size of a regset for the current function, |
237 | in (1) bytes and (2) elements. */ | |
238 | ||
239 | int regset_bytes; | |
240 | int regset_size; | |
241 | ||
d7429b6a | 242 | /* Regset of regs live when calls to `setjmp'-like functions happen. */ |
e881bb1b | 243 | /* ??? Does this exist only for the setjmp-clobbered warning message? */ |
d7429b6a RK |
244 | |
245 | regset regs_live_at_setjmp; | |
246 | ||
247 | /* List made of EXPR_LIST rtx's which gives pairs of pseudo registers | |
248 | that have to go in the same hard reg. | |
249 | The first two regs in the list are a pair, and the next two | |
250 | are another pair, etc. */ | |
251 | rtx regs_may_share; | |
252 | ||
21c7361e AJ |
253 | /* Callback that determines if it's ok for a function to have no |
254 | noreturn attribute. */ | |
255 | int (*lang_missing_noreturn_ok_p) PARAMS ((tree)); | |
256 | ||
d7429b6a RK |
257 | /* Set of registers that may be eliminable. These are handled specially |
258 | in updating regs_ever_live. */ | |
259 | ||
260 | static HARD_REG_SET elim_reg_set; | |
261 | ||
e881bb1b RH |
262 | /* The basic block structure for every insn, indexed by uid. */ |
263 | ||
264 | varray_type basic_block_for_insn; | |
265 | ||
266 | /* The labels mentioned in non-jump rtl. Valid during find_basic_blocks. */ | |
c9bacfdb | 267 | /* ??? Should probably be using LABEL_NUSES instead. It would take a |
e881bb1b RH |
268 | bit of surgery to be able to use or co-opt the routines in jump. */ |
269 | ||
270 | static rtx label_value_list; | |
be1bb652 | 271 | static rtx tail_recursion_label_list; |
e881bb1b | 272 | |
11ae508b RH |
273 | /* Holds information for tracking conditional register life information. */ |
274 | struct reg_cond_life_info | |
275 | { | |
685af3af | 276 | /* A boolean expression of conditions under which a register is dead. */ |
11ae508b | 277 | rtx condition; |
685af3af JW |
278 | /* Conditions under which a register is dead at the basic block end. */ |
279 | rtx orig_condition; | |
280 | ||
281 | /* A boolean expression of conditions under which a register has been | |
282 | stored into. */ | |
283 | rtx stores; | |
11ae508b RH |
284 | |
285 | /* ??? Could store mask of bytes that are dead, so that we could finally | |
286 | track lifetimes of multi-word registers accessed via subregs. */ | |
287 | }; | |
288 | ||
62828c00 RH |
289 | /* For use in communicating between propagate_block and its subroutines. |
290 | Holds all information needed to compute life and def-use information. */ | |
291 | ||
292 | struct propagate_block_info | |
293 | { | |
294 | /* The basic block we're considering. */ | |
295 | basic_block bb; | |
296 | ||
297 | /* Bit N is set if register N is conditionally or unconditionally live. */ | |
298 | regset reg_live; | |
299 | ||
9785c68d RH |
300 | /* Bit N is set if register N is set this insn. */ |
301 | regset new_set; | |
8e3f9094 | 302 | |
62828c00 RH |
303 | /* Element N is the next insn that uses (hard or pseudo) register N |
304 | within the current basic block; or zero, if there is no such insn. */ | |
305 | rtx *reg_next_use; | |
306 | ||
307 | /* Contains a list of all the MEMs we are tracking for dead store | |
308 | elimination. */ | |
309 | rtx mem_set_list; | |
310 | ||
7dfc0fbe BS |
311 | /* If non-null, record the set of registers set unconditionally in the |
312 | basic block. */ | |
62828c00 RH |
313 | regset local_set; |
314 | ||
7dfc0fbe BS |
315 | /* If non-null, record the set of registers set conditionally in the |
316 | basic block. */ | |
317 | regset cond_local_set; | |
318 | ||
11ae508b RH |
319 | #ifdef HAVE_conditional_execution |
320 | /* Indexed by register number, holds a reg_cond_life_info for each | |
321 | register that is not unconditionally live or dead. */ | |
322 | splay_tree reg_cond_dead; | |
323 | ||
324 | /* Bit N is set if register N is in an expression in reg_cond_dead. */ | |
325 | regset reg_cond_reg; | |
326 | #endif | |
327 | ||
0875baa0 RH |
328 | /* The length of mem_set_list. */ |
329 | int mem_set_list_len; | |
330 | ||
62828c00 RH |
331 | /* Non-zero if the value of CC0 is live. */ |
332 | int cc0_live; | |
333 | ||
334 | /* Flags controling the set of information propagate_block collects. */ | |
335 | int flags; | |
336 | }; | |
337 | ||
0875baa0 RH |
338 | /* Maximum length of pbi->mem_set_list before we start dropping |
339 | new elements on the floor. */ | |
340 | #define MAX_MEM_SET_LIST_LEN 100 | |
341 | ||
c9bacfdb | 342 | /* Store the data structures necessary for depth-first search. */ |
b53978a3 JO |
343 | struct depth_first_search_dsS { |
344 | /* stack for backtracking during the algorithm */ | |
345 | basic_block *stack; | |
346 | ||
347 | /* number of edges in the stack. That is, positions 0, ..., sp-1 | |
c9bacfdb | 348 | have edges. */ |
b53978a3 JO |
349 | unsigned int sp; |
350 | ||
351 | /* record of basic blocks already seen by depth-first search */ | |
352 | sbitmap visited_blocks; | |
353 | }; | |
354 | typedef struct depth_first_search_dsS *depth_first_search_ds; | |
355 | ||
63c499dc RK |
356 | /* Have print_rtl_and_abort give the same information that fancy_abort |
357 | does. */ | |
358 | #define print_rtl_and_abort() \ | |
359 | print_rtl_and_abort_fcn (__FILE__, __LINE__, __FUNCTION__) | |
360 | ||
d7429b6a | 361 | /* Forward declarations */ |
711d877c | 362 | static int count_basic_blocks PARAMS ((rtx)); |
be1bb652 | 363 | static void find_basic_blocks_1 PARAMS ((rtx)); |
1bc48f82 | 364 | static rtx find_label_refs PARAMS ((rtx, rtx)); |
711d877c KG |
365 | static void clear_edges PARAMS ((void)); |
366 | static void make_edges PARAMS ((rtx)); | |
711d877c KG |
367 | static void make_label_edge PARAMS ((sbitmap *, basic_block, |
368 | rtx, int)); | |
52a11cbf | 369 | static void make_eh_edge PARAMS ((sbitmap *, basic_block, rtx)); |
711d877c | 370 | static void mark_critical_edges PARAMS ((void)); |
711d877c KG |
371 | |
372 | static void commit_one_edge_insertion PARAMS ((edge)); | |
373 | ||
374 | static void delete_unreachable_blocks PARAMS ((void)); | |
711d877c | 375 | static int can_delete_note_p PARAMS ((rtx)); |
711d877c | 376 | static void expunge_block PARAMS ((basic_block)); |
711d877c | 377 | static int can_delete_label_p PARAMS ((rtx)); |
be1bb652 | 378 | static int tail_recursion_label_p PARAMS ((rtx)); |
711d877c KG |
379 | static int merge_blocks_move_predecessor_nojumps PARAMS ((basic_block, |
380 | basic_block)); | |
381 | static int merge_blocks_move_successor_nojumps PARAMS ((basic_block, | |
336a6399 | 382 | basic_block)); |
711d877c KG |
383 | static int merge_blocks PARAMS ((edge,basic_block,basic_block)); |
384 | static void try_merge_blocks PARAMS ((void)); | |
5568fb48 | 385 | static void tidy_fallthru_edges PARAMS ((void)); |
711d877c KG |
386 | static int verify_wide_reg_1 PARAMS ((rtx *, void *)); |
387 | static void verify_wide_reg PARAMS ((int, rtx, rtx)); | |
388 | static void verify_local_live_at_start PARAMS ((regset, basic_block)); | |
389 | static int set_noop_p PARAMS ((rtx)); | |
390 | static int noop_move_p PARAMS ((rtx)); | |
3ea8083f JL |
391 | static void delete_noop_moves PARAMS ((rtx)); |
392 | static void notice_stack_pointer_modification_1 PARAMS ((rtx, rtx, void *)); | |
393 | static void notice_stack_pointer_modification PARAMS ((rtx)); | |
c13fde05 | 394 | static void mark_reg PARAMS ((rtx, void *)); |
711d877c | 395 | static void mark_regs_live_at_end PARAMS ((regset)); |
4e872036 | 396 | static int set_phi_alternative_reg PARAMS ((rtx, int, int, void *)); |
711d877c | 397 | static void calculate_global_regs_live PARAMS ((sbitmap, sbitmap, int)); |
62828c00 RH |
398 | static void propagate_block_delete_insn PARAMS ((basic_block, rtx)); |
399 | static rtx propagate_block_delete_libcall PARAMS ((basic_block, rtx, rtx)); | |
62828c00 RH |
400 | static int insn_dead_p PARAMS ((struct propagate_block_info *, |
401 | rtx, int, rtx)); | |
402 | static int libcall_dead_p PARAMS ((struct propagate_block_info *, | |
01fbc97d | 403 | rtx, rtx)); |
62828c00 | 404 | static void mark_set_regs PARAMS ((struct propagate_block_info *, |
8e3f9094 | 405 | rtx, rtx)); |
62828c00 | 406 | static void mark_set_1 PARAMS ((struct propagate_block_info *, |
b4593d17 RH |
407 | enum rtx_code, rtx, rtx, |
408 | rtx, int)); | |
11ae508b RH |
409 | #ifdef HAVE_conditional_execution |
410 | static int mark_regno_cond_dead PARAMS ((struct propagate_block_info *, | |
411 | int, rtx)); | |
412 | static void free_reg_cond_life_info PARAMS ((splay_tree_value)); | |
413 | static int flush_reg_cond_reg_1 PARAMS ((splay_tree_node, void *)); | |
414 | static void flush_reg_cond_reg PARAMS ((struct propagate_block_info *, | |
415 | int)); | |
288c2c9e BS |
416 | static rtx elim_reg_cond PARAMS ((rtx, unsigned int)); |
417 | static rtx ior_reg_cond PARAMS ((rtx, rtx, int)); | |
11ae508b | 418 | static rtx not_reg_cond PARAMS ((rtx)); |
288c2c9e | 419 | static rtx and_reg_cond PARAMS ((rtx, rtx, int)); |
11ae508b | 420 | #endif |
1d300e19 | 421 | #ifdef AUTO_INC_DEC |
4b983fdc RH |
422 | static void attempt_auto_inc PARAMS ((struct propagate_block_info *, |
423 | rtx, rtx, rtx, rtx, rtx)); | |
62828c00 RH |
424 | static void find_auto_inc PARAMS ((struct propagate_block_info *, |
425 | rtx, rtx)); | |
426 | static int try_pre_increment_1 PARAMS ((struct propagate_block_info *, | |
427 | rtx)); | |
711d877c | 428 | static int try_pre_increment PARAMS ((rtx, rtx, HOST_WIDE_INT)); |
1d300e19 | 429 | #endif |
62828c00 | 430 | static void mark_used_reg PARAMS ((struct propagate_block_info *, |
8e3f9094 | 431 | rtx, rtx, rtx)); |
62828c00 | 432 | static void mark_used_regs PARAMS ((struct propagate_block_info *, |
8e3f9094 | 433 | rtx, rtx, rtx)); |
711d877c KG |
434 | void dump_flow_info PARAMS ((FILE *)); |
435 | void debug_flow_info PARAMS ((void)); | |
436 | static void dump_edge_info PARAMS ((FILE *, edge, int)); | |
63c499dc RK |
437 | static void print_rtl_and_abort_fcn PARAMS ((const char *, int, |
438 | const char *)) | |
439 | ATTRIBUTE_NORETURN; | |
711d877c | 440 | |
62828c00 RH |
441 | static void invalidate_mems_from_autoinc PARAMS ((struct propagate_block_info *, |
442 | rtx)); | |
1288c070 RH |
443 | static void invalidate_mems_from_set PARAMS ((struct propagate_block_info *, |
444 | rtx)); | |
711d877c | 445 | static void remove_fake_successors PARAMS ((basic_block)); |
21c7361e | 446 | static void flow_nodes_print PARAMS ((const char *, const sbitmap, |
135ebc36 MH |
447 | FILE *)); |
448 | static void flow_edge_list_print PARAMS ((const char *, const edge *, | |
449 | int, FILE *)); | |
450 | static void flow_loops_cfg_dump PARAMS ((const struct loops *, | |
451 | FILE *)); | |
21c7361e | 452 | static int flow_loop_nested_p PARAMS ((struct loop *, |
135ebc36 | 453 | struct loop *)); |
21c7361e | 454 | static int flow_loop_entry_edges_find PARAMS ((basic_block, const sbitmap, |
135ebc36 MH |
455 | edge **)); |
456 | static int flow_loop_exit_edges_find PARAMS ((const sbitmap, edge **)); | |
711d877c | 457 | static int flow_loop_nodes_find PARAMS ((basic_block, basic_block, sbitmap)); |
c34d5374 | 458 | static int flow_depth_first_order_compute PARAMS ((int *, int *)); |
b53978a3 JO |
459 | static void flow_dfs_compute_reverse_init |
460 | PARAMS ((depth_first_search_ds)); | |
461 | static void flow_dfs_compute_reverse_add_bb | |
462 | PARAMS ((depth_first_search_ds, basic_block)); | |
463 | static basic_block flow_dfs_compute_reverse_execute | |
464 | PARAMS ((depth_first_search_ds)); | |
465 | static void flow_dfs_compute_reverse_finish | |
466 | PARAMS ((depth_first_search_ds)); | |
5d6a16e2 MH |
467 | static void flow_loop_pre_header_scan PARAMS ((struct loop *)); |
468 | static basic_block flow_loop_pre_header_find PARAMS ((basic_block, | |
469 | const sbitmap *)); | |
711d877c KG |
470 | static void flow_loop_tree_node_add PARAMS ((struct loop *, struct loop *)); |
471 | static void flow_loops_tree_build PARAMS ((struct loops *)); | |
472 | static int flow_loop_level_compute PARAMS ((struct loop *, int)); | |
473 | static int flow_loops_level_compute PARAMS ((struct loops *)); | |
1f8f4a0b | 474 | static void allocate_bb_life_data PARAMS ((void)); |
a686dbf8 | 475 | static void find_sub_basic_blocks PARAMS ((basic_block)); |
d7429b6a | 476 | \f |
5ece9746 | 477 | /* Find basic blocks of the current function. |
e881bb1b RH |
478 | F is the first insn of the function and NREGS the number of register |
479 | numbers in use. */ | |
d7429b6a RK |
480 | |
481 | void | |
19d3c25c | 482 | find_basic_blocks (f, nregs, file) |
d7429b6a | 483 | rtx f; |
e881bb1b RH |
484 | int nregs ATTRIBUTE_UNUSED; |
485 | FILE *file ATTRIBUTE_UNUSED; | |
d7429b6a | 486 | { |
e881bb1b | 487 | int max_uid; |
d7429b6a | 488 | |
e881bb1b RH |
489 | /* Flush out existing data. */ |
490 | if (basic_block_info != NULL) | |
491 | { | |
492 | int i; | |
421382ac | 493 | |
e881bb1b | 494 | clear_edges (); |
d7429b6a | 495 | |
c9bacfdb | 496 | /* Clear bb->aux on all extant basic blocks. We'll use this as a |
e881bb1b RH |
497 | tag for reuse during create_basic_block, just in case some pass |
498 | copies around basic block notes improperly. */ | |
499 | for (i = 0; i < n_basic_blocks; ++i) | |
500 | BASIC_BLOCK (i)->aux = NULL; | |
d7429b6a | 501 | |
e881bb1b RH |
502 | VARRAY_FREE (basic_block_info); |
503 | } | |
27249135 | 504 | |
e881bb1b | 505 | n_basic_blocks = count_basic_blocks (f); |
27249135 | 506 | |
e881bb1b RH |
507 | /* Size the basic block table. The actual structures will be allocated |
508 | by find_basic_blocks_1, since we want to keep the structure pointers | |
509 | stable across calls to find_basic_blocks. */ | |
510 | /* ??? This whole issue would be much simpler if we called find_basic_blocks | |
c9bacfdb | 511 | exactly once, and thereafter we don't have a single long chain of |
e881bb1b RH |
512 | instructions at all until close to the end of compilation when we |
513 | actually lay them out. */ | |
8cfe18d6 | 514 | |
e881bb1b RH |
515 | VARRAY_BB_INIT (basic_block_info, n_basic_blocks, "basic_block_info"); |
516 | ||
be1bb652 | 517 | find_basic_blocks_1 (f); |
c9bacfdb | 518 | |
e881bb1b RH |
519 | /* Record the block to which an insn belongs. */ |
520 | /* ??? This should be done another way, by which (perhaps) a label is | |
521 | tagged directly with the basic block that it starts. It is used for | |
522 | more than that currently, but IMO that is the only valid use. */ | |
523 | ||
524 | max_uid = get_max_uid (); | |
d7429b6a | 525 | #ifdef AUTO_INC_DEC |
5ece9746 JL |
526 | /* Leave space for insns life_analysis makes in some cases for auto-inc. |
527 | These cases are rare, so we don't need too much space. */ | |
e881bb1b | 528 | max_uid += max_uid / 10; |
d7429b6a RK |
529 | #endif |
530 | ||
2307e372 | 531 | compute_bb_for_insn (max_uid); |
e881bb1b RH |
532 | |
533 | /* Discover the edges of our cfg. */ | |
336a6399 | 534 | make_edges (label_value_list); |
5568fb48 RH |
535 | |
536 | /* Do very simple cleanup now, for the benefit of code that runs between | |
537 | here and cleanup_cfg, e.g. thread_prologue_and_epilogue_insns. */ | |
538 | tidy_fallthru_edges (); | |
539 | ||
e881bb1b RH |
540 | mark_critical_edges (); |
541 | ||
34487bf8 RH |
542 | #ifdef ENABLE_CHECKING |
543 | verify_flow_info (); | |
544 | #endif | |
d7429b6a | 545 | } |
5ece9746 | 546 | |
b313a0fe RH |
547 | void |
548 | check_function_return_warnings () | |
549 | { | |
550 | if (warn_missing_noreturn | |
551 | && !TREE_THIS_VOLATILE (cfun->decl) | |
21c7361e AJ |
552 | && EXIT_BLOCK_PTR->pred == NULL |
553 | && (lang_missing_noreturn_ok_p | |
554 | && !lang_missing_noreturn_ok_p (cfun->decl))) | |
b313a0fe RH |
555 | warning ("function might be possible candidate for attribute `noreturn'"); |
556 | ||
557 | /* If we have a path to EXIT, then we do return. */ | |
558 | if (TREE_THIS_VOLATILE (cfun->decl) | |
559 | && EXIT_BLOCK_PTR->pred != NULL) | |
560 | warning ("`noreturn' function does return"); | |
561 | ||
562 | /* If the clobber_return_insn appears in some basic block, then we | |
563 | do reach the end without returning a value. */ | |
564 | else if (warn_return_type | |
565 | && cfun->x_clobber_return_insn != NULL | |
566 | && EXIT_BLOCK_PTR->pred != NULL) | |
567 | { | |
568 | int max_uid = get_max_uid (); | |
569 | ||
570 | /* If clobber_return_insn was excised by jump1, then renumber_insns | |
571 | can make max_uid smaller than the number still recorded in our rtx. | |
572 | That's fine, since this is a quick way of verifying that the insn | |
573 | is no longer in the chain. */ | |
574 | if (INSN_UID (cfun->x_clobber_return_insn) < max_uid) | |
575 | { | |
576 | /* Recompute insn->block mapping, since the initial mapping is | |
577 | set before we delete unreachable blocks. */ | |
578 | compute_bb_for_insn (max_uid); | |
579 | ||
580 | if (BLOCK_FOR_INSN (cfun->x_clobber_return_insn) != NULL) | |
581 | warning ("control reaches end of non-void function"); | |
582 | } | |
583 | } | |
584 | } | |
585 | ||
e881bb1b | 586 | /* Count the basic blocks of the function. */ |
dc2ede84 | 587 | |
c9bacfdb | 588 | static int |
e881bb1b RH |
589 | count_basic_blocks (f) |
590 | rtx f; | |
591 | { | |
592 | register rtx insn; | |
593 | register RTX_CODE prev_code; | |
594 | register int count = 0; | |
52a11cbf | 595 | int saw_abnormal_edge = 0; |
dc2ede84 | 596 | |
e881bb1b RH |
597 | prev_code = JUMP_INSN; |
598 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
599 | { | |
52a11cbf | 600 | enum rtx_code code = GET_CODE (insn); |
e881bb1b | 601 | |
e881bb1b RH |
602 | if (code == CODE_LABEL |
603 | || (GET_RTX_CLASS (code) == 'i' | |
604 | && (prev_code == JUMP_INSN | |
605 | || prev_code == BARRIER | |
52a11cbf RH |
606 | || saw_abnormal_edge))) |
607 | { | |
608 | saw_abnormal_edge = 0; | |
609 | count++; | |
610 | } | |
314883b8 | 611 | |
52a11cbf | 612 | /* Record whether this insn created an edge. */ |
e881bb1b RH |
613 | if (code == CALL_INSN) |
614 | { | |
52a11cbf RH |
615 | rtx note; |
616 | ||
617 | /* If there is a nonlocal goto label and the specified | |
618 | region number isn't -1, we have an edge. */ | |
619 | if (nonlocal_goto_handler_labels | |
620 | && ((note = find_reg_note (insn, REG_EH_REGION, NULL_RTX)) == 0 | |
621 | || INTVAL (XEXP (note, 0)) >= 0)) | |
622 | saw_abnormal_edge = 1; | |
623 | ||
624 | else if (can_throw_internal (insn)) | |
625 | saw_abnormal_edge = 1; | |
e881bb1b | 626 | } |
52a11cbf RH |
627 | else if (flag_non_call_exceptions |
628 | && code == INSN | |
629 | && can_throw_internal (insn)) | |
630 | saw_abnormal_edge = 1; | |
e881bb1b RH |
631 | |
632 | if (code != NOTE) | |
633 | prev_code = code; | |
e881bb1b RH |
634 | } |
635 | ||
636 | /* The rest of the compiler works a bit smoother when we don't have to | |
637 | check for the edge case of do-nothing functions with no basic blocks. */ | |
638 | if (count == 0) | |
639 | { | |
640 | emit_insn (gen_rtx_USE (VOIDmode, const0_rtx)); | |
641 | count = 1; | |
642 | } | |
643 | ||
644 | return count; | |
645 | } | |
dc2ede84 | 646 | |
4eb00163 | 647 | /* Scan a list of insns for labels referred to other than by jumps. |
1bc48f82 | 648 | This is used to scan the alternatives of a call placeholder. */ |
4eb00163 JO |
649 | static rtx |
650 | find_label_refs (f, lvl) | |
1bc48f82 RE |
651 | rtx f; |
652 | rtx lvl; | |
653 | { | |
654 | rtx insn; | |
655 | ||
656 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
f759eb8b | 657 | if (INSN_P (insn) && GET_CODE (insn) != JUMP_INSN) |
1bc48f82 RE |
658 | { |
659 | rtx note; | |
660 | ||
661 | /* Make a list of all labels referred to other than by jumps | |
c9bacfdb | 662 | (which just don't have the REG_LABEL notes). |
1bc48f82 RE |
663 | |
664 | Make a special exception for labels followed by an ADDR*VEC, | |
c9bacfdb | 665 | as this would be a part of the tablejump setup code. |
1bc48f82 | 666 | |
f759eb8b AO |
667 | Make a special exception to registers loaded with label |
668 | values just before jump insns that use them. */ | |
c9bacfdb | 669 | |
1bc48f82 RE |
670 | for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) |
671 | if (REG_NOTE_KIND (note) == REG_LABEL) | |
672 | { | |
673 | rtx lab = XEXP (note, 0), next; | |
674 | ||
52a11cbf | 675 | if ((next = next_nonnote_insn (lab)) != NULL |
1bc48f82 RE |
676 | && GET_CODE (next) == JUMP_INSN |
677 | && (GET_CODE (PATTERN (next)) == ADDR_VEC | |
678 | || GET_CODE (PATTERN (next)) == ADDR_DIFF_VEC)) | |
679 | ; | |
680 | else if (GET_CODE (lab) == NOTE) | |
681 | ; | |
f759eb8b AO |
682 | else if (GET_CODE (NEXT_INSN (insn)) == JUMP_INSN |
683 | && find_reg_note (NEXT_INSN (insn), REG_LABEL, lab)) | |
684 | ; | |
1bc48f82 RE |
685 | else |
686 | lvl = alloc_EXPR_LIST (0, XEXP (note, 0), lvl); | |
687 | } | |
688 | } | |
689 | ||
690 | return lvl; | |
691 | } | |
692 | ||
a686dbf8 JH |
693 | /* Assume that someone emitted code with control flow instructions to the |
694 | basic block. Update the data structure. */ | |
695 | static void | |
696 | find_sub_basic_blocks (bb) | |
697 | basic_block bb; | |
698 | { | |
699 | rtx first_insn = bb->head, insn; | |
700 | rtx end = bb->end; | |
701 | edge succ_list = bb->succ; | |
702 | rtx jump_insn = NULL_RTX; | |
703 | int created = 0; | |
704 | int barrier = 0; | |
705 | edge falltru = 0; | |
706 | basic_block first_bb = bb, last_bb; | |
707 | int i; | |
708 | ||
709 | if (GET_CODE (first_insn) == LABEL_REF) | |
710 | first_insn = NEXT_INSN (first_insn); | |
711 | first_insn = NEXT_INSN (first_insn); | |
712 | bb->succ = NULL; | |
713 | ||
714 | insn = first_insn; | |
715 | /* Scan insn chain and try to find new basic block boundaries. */ | |
716 | while (insn != end) | |
717 | { | |
718 | enum rtx_code code = GET_CODE (insn); | |
719 | switch (code) | |
720 | { | |
721 | case JUMP_INSN: | |
722 | /* We need some special care for those expressions. */ | |
723 | if (GET_CODE (PATTERN (insn)) == ADDR_VEC | |
724 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC) | |
725 | abort(); | |
726 | jump_insn = insn; | |
727 | break; | |
728 | case BARRIER: | |
729 | if (!jump_insn) | |
730 | abort (); | |
731 | barrier = 1; | |
732 | break; | |
733 | /* On code label, split current basic block. */ | |
734 | case CODE_LABEL: | |
735 | falltru = split_block (bb, PREV_INSN (insn)); | |
736 | if (jump_insn) | |
737 | bb->end = jump_insn; | |
738 | bb = falltru->dest; | |
739 | if (barrier) | |
740 | remove_edge (falltru); | |
741 | barrier = 0; | |
742 | jump_insn = 0; | |
743 | created = 1; | |
744 | if (LABEL_ALTERNATE_NAME (insn)) | |
745 | make_edge (NULL, ENTRY_BLOCK_PTR, bb, 0); | |
746 | break; | |
747 | case INSN: | |
748 | /* In case we've previously split insn on the JUMP_INSN, move the | |
749 | block header to proper place. */ | |
750 | if (jump_insn) | |
751 | { | |
752 | falltru = split_block (bb, PREV_INSN (insn)); | |
753 | bb->end = jump_insn; | |
754 | bb = falltru->dest; | |
755 | if (barrier) | |
756 | abort (); | |
757 | jump_insn = 0; | |
758 | } | |
759 | default: | |
760 | break; | |
761 | } | |
762 | insn = NEXT_INSN (insn); | |
763 | } | |
764 | /* Last basic block must end in the original BB end. */ | |
765 | if (jump_insn) | |
766 | abort (); | |
767 | ||
768 | /* Wire in the original edges for last basic block. */ | |
769 | if (created) | |
770 | { | |
771 | bb->succ = succ_list; | |
772 | while (succ_list) | |
773 | succ_list->src = bb, succ_list = succ_list->succ_next; | |
774 | } | |
775 | else | |
776 | bb->succ = succ_list; | |
777 | ||
778 | /* Now re-scan and wire in all edges. This expect simple (conditional) | |
779 | jumps at the end of each new basic blocks. */ | |
780 | last_bb = bb; | |
781 | for (i = first_bb->index; i < last_bb->index; i++) | |
782 | { | |
783 | bb = BASIC_BLOCK (i); | |
784 | if (GET_CODE (bb->end) == JUMP_INSN) | |
785 | { | |
786 | mark_jump_label (PATTERN (bb->end), bb->end, 0, 0); | |
787 | make_label_edge (NULL, bb, JUMP_LABEL (bb->end), 0); | |
788 | } | |
789 | insn = NEXT_INSN (insn); | |
790 | } | |
791 | } | |
792 | ||
d7429b6a | 793 | /* Find all basic blocks of the function whose first insn is F. |
d7429b6a | 794 | |
336a6399 RH |
795 | Collect and return a list of labels whose addresses are taken. This |
796 | will be used in make_edges for use with computed gotos. */ | |
8329b5ec | 797 | |
be1bb652 | 798 | static void |
336a6399 | 799 | find_basic_blocks_1 (f) |
e881bb1b | 800 | rtx f; |
e881bb1b RH |
801 | { |
802 | register rtx insn, next; | |
e881bb1b RH |
803 | int i = 0; |
804 | rtx bb_note = NULL_RTX; | |
be1bb652 RH |
805 | rtx lvl = NULL_RTX; |
806 | rtx trll = NULL_RTX; | |
e881bb1b RH |
807 | rtx head = NULL_RTX; |
808 | rtx end = NULL_RTX; | |
c9bacfdb | 809 | |
e881bb1b RH |
810 | /* We process the instructions in a slightly different way than we did |
811 | previously. This is so that we see a NOTE_BASIC_BLOCK after we have | |
812 | closed out the previous block, so that it gets attached at the proper | |
813 | place. Since this form should be equivalent to the previous, | |
336a6399 | 814 | count_basic_blocks continues to use the old form as a check. */ |
d7429b6a | 815 | |
e881bb1b RH |
816 | for (insn = f; insn; insn = next) |
817 | { | |
818 | enum rtx_code code = GET_CODE (insn); | |
d7429b6a | 819 | |
e881bb1b | 820 | next = NEXT_INSN (insn); |
d7429b6a | 821 | |
e881bb1b | 822 | switch (code) |
e658434c | 823 | { |
e881bb1b RH |
824 | case NOTE: |
825 | { | |
826 | int kind = NOTE_LINE_NUMBER (insn); | |
827 | ||
c9bacfdb | 828 | /* Look for basic block notes with which to keep the |
e881bb1b RH |
829 | basic_block_info pointers stable. Unthread the note now; |
830 | we'll put it back at the right place in create_basic_block. | |
831 | Or not at all if we've already found a note in this block. */ | |
52a11cbf | 832 | if (kind == NOTE_INSN_BASIC_BLOCK) |
e881bb1b RH |
833 | { |
834 | if (bb_note == NULL_RTX) | |
835 | bb_note = insn; | |
47095bfc RH |
836 | else |
837 | next = flow_delete_insn (insn); | |
e881bb1b | 838 | } |
e881bb1b RH |
839 | break; |
840 | } | |
d7429b6a | 841 | |
e881bb1b | 842 | case CODE_LABEL: |
c9bacfdb | 843 | /* A basic block starts at a label. If we've closed one off due |
e881bb1b RH |
844 | to a barrier or some such, no need to do it again. */ |
845 | if (head != NULL_RTX) | |
2ec1535d | 846 | { |
e881bb1b RH |
847 | /* While we now have edge lists with which other portions of |
848 | the compiler might determine a call ending a basic block | |
849 | does not imply an abnormal edge, it will be a bit before | |
850 | everything can be updated. So continue to emit a noop at | |
851 | the end of such a block. */ | |
314883b8 | 852 | if (GET_CODE (end) == CALL_INSN && ! SIBLING_CALL_P (end)) |
e881bb1b RH |
853 | { |
854 | rtx nop = gen_rtx_USE (VOIDmode, const0_rtx); | |
855 | end = emit_insn_after (nop, end); | |
856 | } | |
857 | ||
e881bb1b RH |
858 | create_basic_block (i++, head, end, bb_note); |
859 | bb_note = NULL_RTX; | |
2ec1535d | 860 | } |
314883b8 | 861 | |
e881bb1b RH |
862 | head = end = insn; |
863 | break; | |
d06c6389 | 864 | |
e881bb1b RH |
865 | case JUMP_INSN: |
866 | /* A basic block ends at a jump. */ | |
867 | if (head == NULL_RTX) | |
868 | head = insn; | |
869 | else | |
870 | { | |
c9bacfdb | 871 | /* ??? Make a special check for table jumps. The way this |
7a3b7acb | 872 | happens is truly and amazingly gross. We are about to |
e881bb1b RH |
873 | create a basic block that contains just a code label and |
874 | an addr*vec jump insn. Worse, an addr_diff_vec creates | |
875 | its own natural loop. | |
5c35539b | 876 | |
e881bb1b | 877 | Prevent this bit of brain damage, pasting things together |
c9bacfdb | 878 | correctly in make_edges. |
2c3a56ad | 879 | |
e881bb1b RH |
880 | The correct solution involves emitting the table directly |
881 | on the tablejump instruction as a note, or JUMP_LABEL. */ | |
e658434c | 882 | |
e881bb1b RH |
883 | if (GET_CODE (PATTERN (insn)) == ADDR_VEC |
884 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC) | |
885 | { | |
886 | head = end = NULL; | |
887 | n_basic_blocks--; | |
888 | break; | |
889 | } | |
890 | } | |
891 | end = insn; | |
892 | goto new_bb_inclusive; | |
d7429b6a | 893 | |
e881bb1b RH |
894 | case BARRIER: |
895 | /* A basic block ends at a barrier. It may be that an unconditional | |
896 | jump already closed the basic block -- no need to do it again. */ | |
897 | if (head == NULL_RTX) | |
898 | break; | |
d7429b6a | 899 | |
e881bb1b RH |
900 | /* While we now have edge lists with which other portions of the |
901 | compiler might determine a call ending a basic block does not | |
902 | imply an abnormal edge, it will be a bit before everything can | |
903 | be updated. So continue to emit a noop at the end of such a | |
904 | block. */ | |
314883b8 | 905 | if (GET_CODE (end) == CALL_INSN && ! SIBLING_CALL_P (end)) |
e881bb1b RH |
906 | { |
907 | rtx nop = gen_rtx_USE (VOIDmode, const0_rtx); | |
908 | end = emit_insn_after (nop, end); | |
909 | } | |
910 | goto new_bb_exclusive; | |
911 | ||
912 | case CALL_INSN: | |
314883b8 RK |
913 | { |
914 | /* Record whether this call created an edge. */ | |
915 | rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); | |
52a11cbf | 916 | int region = (note ? INTVAL (XEXP (note, 0)) : 0); |
314883b8 | 917 | |
1bc48f82 RE |
918 | if (GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER) |
919 | { | |
920 | /* Scan each of the alternatives for label refs. */ | |
921 | lvl = find_label_refs (XEXP (PATTERN (insn), 0), lvl); | |
922 | lvl = find_label_refs (XEXP (PATTERN (insn), 1), lvl); | |
923 | lvl = find_label_refs (XEXP (PATTERN (insn), 2), lvl); | |
924 | /* Record its tail recursion label, if any. */ | |
925 | if (XEXP (PATTERN (insn), 3) != NULL_RTX) | |
926 | trll = alloc_EXPR_LIST (0, XEXP (PATTERN (insn), 3), trll); | |
927 | } | |
be1bb652 | 928 | |
314883b8 | 929 | /* A basic block ends at a call that can either throw or |
c29ea88a | 930 | do a non-local goto. */ |
52a11cbf RH |
931 | if ((nonlocal_goto_handler_labels && region >= 0) |
932 | || can_throw_internal (insn)) | |
314883b8 RK |
933 | { |
934 | new_bb_inclusive: | |
935 | if (head == NULL_RTX) | |
936 | head = insn; | |
937 | end = insn; | |
938 | ||
939 | new_bb_exclusive: | |
940 | create_basic_block (i++, head, end, bb_note); | |
941 | head = end = NULL_RTX; | |
942 | bb_note = NULL_RTX; | |
943 | break; | |
944 | } | |
c9bacfdb KH |
945 | } |
946 | /* Fall through. */ | |
d7429b6a | 947 | |
52a11cbf RH |
948 | case INSN: |
949 | /* Non-call exceptions generate new blocks just like calls. */ | |
950 | if (flag_non_call_exceptions && can_throw_internal (insn)) | |
951 | goto new_bb_inclusive; | |
952 | ||
953 | if (head == NULL_RTX) | |
954 | head = insn; | |
955 | end = insn; | |
e881bb1b | 956 | break; |
52a11cbf RH |
957 | |
958 | default: | |
959 | abort (); | |
e881bb1b | 960 | } |
d7429b6a | 961 | |
52a11cbf | 962 | if (GET_CODE (insn) == INSN || GET_CODE (insn) == CALL_INSN) |
d7429b6a | 963 | { |
e881bb1b | 964 | rtx note; |
421382ac | 965 | |
f759eb8b | 966 | /* Make a list of all labels referred to other than by jumps. |
2ec1535d | 967 | |
e881bb1b | 968 | Make a special exception for labels followed by an ADDR*VEC, |
c9bacfdb | 969 | as this would be a part of the tablejump setup code. |
421382ac | 970 | |
f759eb8b AO |
971 | Make a special exception to registers loaded with label |
972 | values just before jump insns that use them. */ | |
c9bacfdb | 973 | |
e881bb1b | 974 | for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) |
c29ea88a RK |
975 | if (REG_NOTE_KIND (note) == REG_LABEL) |
976 | { | |
977 | rtx lab = XEXP (note, 0), next; | |
314883b8 | 978 | |
52a11cbf | 979 | if ((next = next_nonnote_insn (lab)) != NULL |
c29ea88a RK |
980 | && GET_CODE (next) == JUMP_INSN |
981 | && (GET_CODE (PATTERN (next)) == ADDR_VEC | |
982 | || GET_CODE (PATTERN (next)) == ADDR_DIFF_VEC)) | |
983 | ; | |
be1bb652 RH |
984 | else if (GET_CODE (lab) == NOTE) |
985 | ; | |
f759eb8b AO |
986 | else if (GET_CODE (NEXT_INSN (insn)) == JUMP_INSN |
987 | && find_reg_note (NEXT_INSN (insn), REG_LABEL, lab)) | |
988 | ; | |
c29ea88a | 989 | else |
be1bb652 | 990 | lvl = alloc_EXPR_LIST (0, XEXP (note, 0), lvl); |
c29ea88a | 991 | } |
d7429b6a | 992 | } |
e881bb1b | 993 | } |
d7429b6a | 994 | |
e881bb1b | 995 | if (head != NULL_RTX) |
336a6399 | 996 | create_basic_block (i++, head, end, bb_note); |
0d12ea97 RH |
997 | else if (bb_note) |
998 | flow_delete_insn (bb_note); | |
af14ce9c | 999 | |
e881bb1b RH |
1000 | if (i != n_basic_blocks) |
1001 | abort (); | |
af14ce9c | 1002 | |
be1bb652 RH |
1003 | label_value_list = lvl; |
1004 | tail_recursion_label_list = trll; | |
d7429b6a | 1005 | } |
5ece9746 | 1006 | |
19d3c25c RH |
1007 | /* Tidy the CFG by deleting unreachable code and whatnot. */ |
1008 | ||
1009 | void | |
2f2ee4bb | 1010 | cleanup_cfg () |
19d3c25c RH |
1011 | { |
1012 | delete_unreachable_blocks (); | |
19d3c25c RH |
1013 | try_merge_blocks (); |
1014 | mark_critical_edges (); | |
2cade2ad CP |
1015 | |
1016 | /* Kill the data we won't maintain. */ | |
be1bb652 RH |
1017 | free_EXPR_LIST_list (&label_value_list); |
1018 | free_EXPR_LIST_list (&tail_recursion_label_list); | |
19d3c25c RH |
1019 | } |
1020 | ||
e881bb1b RH |
1021 | /* Create a new basic block consisting of the instructions between |
1022 | HEAD and END inclusive. Reuses the note and basic block struct | |
1023 | in BB_NOTE, if any. */ | |
5ece9746 | 1024 | |
295ae817 | 1025 | void |
e881bb1b RH |
1026 | create_basic_block (index, head, end, bb_note) |
1027 | int index; | |
1028 | rtx head, end, bb_note; | |
5ece9746 | 1029 | { |
e881bb1b RH |
1030 | basic_block bb; |
1031 | ||
1032 | if (bb_note | |
b3bf5bde | 1033 | && ! RTX_INTEGRATED_P (bb_note) |
e881bb1b RH |
1034 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL |
1035 | && bb->aux == NULL) | |
5ece9746 | 1036 | { |
e881bb1b RH |
1037 | /* If we found an existing note, thread it back onto the chain. */ |
1038 | ||
47095bfc RH |
1039 | rtx after; |
1040 | ||
e881bb1b | 1041 | if (GET_CODE (head) == CODE_LABEL) |
47095bfc | 1042 | after = head; |
e881bb1b RH |
1043 | else |
1044 | { | |
47095bfc | 1045 | after = PREV_INSN (head); |
e881bb1b RH |
1046 | head = bb_note; |
1047 | } | |
47095bfc RH |
1048 | |
1049 | if (after != bb_note && NEXT_INSN (after) != bb_note) | |
1050 | reorder_insns (bb_note, bb_note, after); | |
5ece9746 | 1051 | } |
e881bb1b RH |
1052 | else |
1053 | { | |
1054 | /* Otherwise we must create a note and a basic block structure. | |
1055 | Since we allow basic block structs in rtl, give the struct | |
1056 | the same lifetime by allocating it off the function obstack | |
1057 | rather than using malloc. */ | |
8329b5ec | 1058 | |
1f8f4a0b | 1059 | bb = (basic_block) obstack_alloc (&flow_obstack, sizeof (*bb)); |
e881bb1b | 1060 | memset (bb, 0, sizeof (*bb)); |
421382ac | 1061 | |
e881bb1b RH |
1062 | if (GET_CODE (head) == CODE_LABEL) |
1063 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
1064 | else | |
1065 | { | |
1066 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
1067 | head = bb_note; | |
1068 | } | |
1069 | NOTE_BASIC_BLOCK (bb_note) = bb; | |
1070 | } | |
1071 | ||
eeea333e RH |
1072 | /* Always include the bb note in the block. */ |
1073 | if (NEXT_INSN (end) == bb_note) | |
1074 | end = bb_note; | |
1075 | ||
e881bb1b RH |
1076 | bb->head = head; |
1077 | bb->end = end; | |
1078 | bb->index = index; | |
1079 | BASIC_BLOCK (index) = bb; | |
1080 | ||
1081 | /* Tag the block so that we know it has been used when considering | |
1082 | other basic block notes. */ | |
1083 | bb->aux = bb; | |
421382ac | 1084 | } |
e881bb1b RH |
1085 | \f |
1086 | /* Records the basic block struct in BB_FOR_INSN, for every instruction | |
1087 | indexed by INSN_UID. MAX is the size of the array. */ | |
421382ac | 1088 | |
2307e372 RH |
1089 | void |
1090 | compute_bb_for_insn (max) | |
e881bb1b | 1091 | int max; |
421382ac | 1092 | { |
e881bb1b | 1093 | int i; |
421382ac | 1094 | |
49c3bb12 RH |
1095 | if (basic_block_for_insn) |
1096 | VARRAY_FREE (basic_block_for_insn); | |
2307e372 RH |
1097 | VARRAY_BB_INIT (basic_block_for_insn, max, "basic_block_for_insn"); |
1098 | ||
e881bb1b RH |
1099 | for (i = 0; i < n_basic_blocks; ++i) |
1100 | { | |
1101 | basic_block bb = BASIC_BLOCK (i); | |
1102 | rtx insn, end; | |
1103 | ||
1104 | end = bb->end; | |
1105 | insn = bb->head; | |
1106 | while (1) | |
1107 | { | |
1108 | int uid = INSN_UID (insn); | |
1109 | if (uid < max) | |
2307e372 | 1110 | VARRAY_BB (basic_block_for_insn, uid) = bb; |
e881bb1b RH |
1111 | if (insn == end) |
1112 | break; | |
1113 | insn = NEXT_INSN (insn); | |
1114 | } | |
1115 | } | |
421382ac BS |
1116 | } |
1117 | ||
e881bb1b | 1118 | /* Free the memory associated with the edge structures. */ |
421382ac BS |
1119 | |
1120 | static void | |
e881bb1b | 1121 | clear_edges () |
421382ac | 1122 | { |
e881bb1b RH |
1123 | int i; |
1124 | edge n, e; | |
421382ac | 1125 | |
e881bb1b | 1126 | for (i = 0; i < n_basic_blocks; ++i) |
421382ac | 1127 | { |
e881bb1b | 1128 | basic_block bb = BASIC_BLOCK (i); |
421382ac | 1129 | |
c9bacfdb | 1130 | for (e = bb->succ; e; e = n) |
421382ac | 1131 | { |
e881bb1b RH |
1132 | n = e->succ_next; |
1133 | free (e); | |
421382ac | 1134 | } |
e881bb1b RH |
1135 | |
1136 | bb->succ = 0; | |
1137 | bb->pred = 0; | |
1138 | } | |
1139 | ||
c9bacfdb | 1140 | for (e = ENTRY_BLOCK_PTR->succ; e; e = n) |
e881bb1b RH |
1141 | { |
1142 | n = e->succ_next; | |
1143 | free (e); | |
421382ac | 1144 | } |
e881bb1b RH |
1145 | |
1146 | ENTRY_BLOCK_PTR->succ = 0; | |
1147 | EXIT_BLOCK_PTR->pred = 0; | |
d3a923ee RH |
1148 | |
1149 | n_edges = 0; | |
421382ac BS |
1150 | } |
1151 | ||
e881bb1b RH |
1152 | /* Identify the edges between basic blocks. |
1153 | ||
1154 | NONLOCAL_LABEL_LIST is a list of non-local labels in the function. Blocks | |
1155 | that are otherwise unreachable may be reachable with a non-local goto. | |
1156 | ||
c9bacfdb | 1157 | BB_EH_END is an array indexed by basic block number in which we record |
e881bb1b RH |
1158 | the list of exception regions active at the end of the basic block. */ |
1159 | ||
dc2ede84 | 1160 | static void |
336a6399 | 1161 | make_edges (label_value_list) |
e881bb1b | 1162 | rtx label_value_list; |
dc2ede84 | 1163 | { |
e881bb1b | 1164 | int i; |
dbf08f94 | 1165 | sbitmap *edge_cache = NULL; |
e881bb1b RH |
1166 | |
1167 | /* Assume no computed jump; revise as we create edges. */ | |
1168 | current_function_has_computed_jump = 0; | |
1169 | ||
dbf08f94 RH |
1170 | /* Heavy use of computed goto in machine-generated code can lead to |
1171 | nearly fully-connected CFGs. In that case we spend a significant | |
1172 | amount of time searching the edge lists for duplicates. */ | |
1173 | if (forced_labels || label_value_list) | |
1174 | { | |
1175 | edge_cache = sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks); | |
1176 | sbitmap_vector_zero (edge_cache, n_basic_blocks); | |
1177 | } | |
1178 | ||
e881bb1b | 1179 | /* By nature of the way these get numbered, block 0 is always the entry. */ |
dbf08f94 | 1180 | make_edge (edge_cache, ENTRY_BLOCK_PTR, BASIC_BLOCK (0), EDGE_FALLTHRU); |
dc2ede84 | 1181 | |
e881bb1b | 1182 | for (i = 0; i < n_basic_blocks; ++i) |
421382ac | 1183 | { |
e881bb1b | 1184 | basic_block bb = BASIC_BLOCK (i); |
336a6399 | 1185 | rtx insn, x; |
e881bb1b | 1186 | enum rtx_code code; |
4b523fc4 | 1187 | int force_fallthru = 0; |
421382ac | 1188 | |
a686dbf8 JH |
1189 | if (GET_CODE (bb->head) == CODE_LABEL |
1190 | && LABEL_ALTERNATE_NAME (bb->head)) | |
1191 | make_edge (NULL, ENTRY_BLOCK_PTR, bb, 0); | |
1192 | ||
336a6399 | 1193 | /* Examine the last instruction of the block, and discover the |
e881bb1b RH |
1194 | ways we can leave the block. */ |
1195 | ||
1196 | insn = bb->end; | |
1197 | code = GET_CODE (insn); | |
1198 | ||
1199 | /* A branch. */ | |
1200 | if (code == JUMP_INSN) | |
1201 | { | |
1202 | rtx tmp; | |
1203 | ||
52a11cbf RH |
1204 | /* Recognize exception handling placeholders. */ |
1205 | if (GET_CODE (PATTERN (insn)) == RESX) | |
1206 | make_eh_edge (edge_cache, bb, insn); | |
1207 | ||
4b01bd16 RH |
1208 | /* Recognize a non-local goto as a branch outside the |
1209 | current function. */ | |
52a11cbf | 1210 | else if (find_reg_note (insn, REG_NON_LOCAL_GOTO, NULL_RTX)) |
4b01bd16 RH |
1211 | ; |
1212 | ||
e881bb1b | 1213 | /* ??? Recognize a tablejump and do the right thing. */ |
4b01bd16 RH |
1214 | else if ((tmp = JUMP_LABEL (insn)) != NULL_RTX |
1215 | && (tmp = NEXT_INSN (tmp)) != NULL_RTX | |
1216 | && GET_CODE (tmp) == JUMP_INSN | |
1217 | && (GET_CODE (PATTERN (tmp)) == ADDR_VEC | |
1218 | || GET_CODE (PATTERN (tmp)) == ADDR_DIFF_VEC)) | |
e881bb1b RH |
1219 | { |
1220 | rtvec vec; | |
1221 | int j; | |
1222 | ||
1223 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) | |
1224 | vec = XVEC (PATTERN (tmp), 0); | |
1225 | else | |
1226 | vec = XVEC (PATTERN (tmp), 1); | |
1227 | ||
1228 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
dbf08f94 RH |
1229 | make_label_edge (edge_cache, bb, |
1230 | XEXP (RTVEC_ELT (vec, j), 0), 0); | |
4b523fc4 RE |
1231 | |
1232 | /* Some targets (eg, ARM) emit a conditional jump that also | |
1233 | contains the out-of-range target. Scan for these and | |
1234 | add an edge if necessary. */ | |
1235 | if ((tmp = single_set (insn)) != NULL | |
1236 | && SET_DEST (tmp) == pc_rtx | |
1237 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
1238 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF) | |
dbf08f94 RH |
1239 | make_label_edge (edge_cache, bb, |
1240 | XEXP (XEXP (SET_SRC (tmp), 2), 0), 0); | |
4b523fc4 RE |
1241 | |
1242 | #ifdef CASE_DROPS_THROUGH | |
1243 | /* Silly VAXen. The ADDR_VEC is going to be in the way of | |
1244 | us naturally detecting fallthru into the next block. */ | |
1245 | force_fallthru = 1; | |
1246 | #endif | |
e881bb1b RH |
1247 | } |
1248 | ||
1249 | /* If this is a computed jump, then mark it as reaching | |
1250 | everything on the label_value_list and forced_labels list. */ | |
1251 | else if (computed_jump_p (insn)) | |
1252 | { | |
dc2ede84 | 1253 | current_function_has_computed_jump = 1; |
dc2ede84 | 1254 | |
e881bb1b | 1255 | for (x = label_value_list; x; x = XEXP (x, 1)) |
dbf08f94 | 1256 | make_label_edge (edge_cache, bb, XEXP (x, 0), EDGE_ABNORMAL); |
c9bacfdb | 1257 | |
dc2ede84 | 1258 | for (x = forced_labels; x; x = XEXP (x, 1)) |
dbf08f94 | 1259 | make_label_edge (edge_cache, bb, XEXP (x, 0), EDGE_ABNORMAL); |
dc2ede84 BS |
1260 | } |
1261 | ||
e881bb1b RH |
1262 | /* Returns create an exit out. */ |
1263 | else if (returnjump_p (insn)) | |
dbf08f94 | 1264 | make_edge (edge_cache, bb, EXIT_BLOCK_PTR, 0); |
e881bb1b RH |
1265 | |
1266 | /* Otherwise, we have a plain conditional or unconditional jump. */ | |
1267 | else | |
dc2ede84 | 1268 | { |
e881bb1b RH |
1269 | if (! JUMP_LABEL (insn)) |
1270 | abort (); | |
dbf08f94 | 1271 | make_label_edge (edge_cache, bb, JUMP_LABEL (insn), 0); |
e881bb1b RH |
1272 | } |
1273 | } | |
1274 | ||
c9bacfdb | 1275 | /* If this is a sibling call insn, then this is in effect a |
0a1c58a2 JL |
1276 | combined call and return, and so we need an edge to the |
1277 | exit block. No need to worry about EH edges, since we | |
1278 | wouldn't have created the sibling call in the first place. */ | |
1279 | ||
1280 | if (code == CALL_INSN && SIBLING_CALL_P (insn)) | |
9a1ba437 RH |
1281 | make_edge (edge_cache, bb, EXIT_BLOCK_PTR, |
1282 | EDGE_ABNORMAL | EDGE_ABNORMAL_CALL); | |
0a1c58a2 | 1283 | |
e881bb1b | 1284 | /* If this is a CALL_INSN, then mark it as reaching the active EH |
52a11cbf | 1285 | handler for this CALL_INSN. If we're handling non-call |
e881bb1b | 1286 | exceptions then any insn can reach any of the active handlers. |
b472794d | 1287 | |
e881bb1b | 1288 | Also mark the CALL_INSN as reaching any nonlocal goto handler. */ |
b472794d | 1289 | |
c1e9f663 | 1290 | else if (code == CALL_INSN || flag_non_call_exceptions) |
e881bb1b | 1291 | { |
52a11cbf RH |
1292 | /* Add any appropriate EH edges. */ |
1293 | make_eh_edge (edge_cache, bb, insn); | |
e881bb1b RH |
1294 | |
1295 | if (code == CALL_INSN && nonlocal_goto_handler_labels) | |
1296 | { | |
dc2ede84 BS |
1297 | /* ??? This could be made smarter: in some cases it's possible |
1298 | to tell that certain calls will not do a nonlocal goto. | |
1299 | ||
1300 | For example, if the nested functions that do the nonlocal | |
1301 | gotos do not have their addresses taken, then only calls to | |
1302 | those functions or to other nested functions that use them | |
1303 | could possibly do nonlocal gotos. */ | |
1ef1bf06 AM |
1304 | /* We do know that a REG_EH_REGION note with a value less |
1305 | than 0 is guaranteed not to perform a non-local goto. */ | |
1306 | rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); | |
12a41c48 | 1307 | if (!note || INTVAL (XEXP (note, 0)) >= 0) |
c9bacfdb | 1308 | for (x = nonlocal_goto_handler_labels; x; x = XEXP (x, 1)) |
dbf08f94 | 1309 | make_label_edge (edge_cache, bb, XEXP (x, 0), |
1ef1bf06 | 1310 | EDGE_ABNORMAL | EDGE_ABNORMAL_CALL); |
dc2ede84 BS |
1311 | } |
1312 | } | |
e881bb1b | 1313 | |
e881bb1b RH |
1314 | /* Find out if we can drop through to the next block. */ |
1315 | insn = next_nonnote_insn (insn); | |
4b523fc4 | 1316 | if (!insn || (i + 1 == n_basic_blocks && force_fallthru)) |
dbf08f94 | 1317 | make_edge (edge_cache, bb, EXIT_BLOCK_PTR, EDGE_FALLTHRU); |
e881bb1b RH |
1318 | else if (i + 1 < n_basic_blocks) |
1319 | { | |
1320 | rtx tmp = BLOCK_HEAD (i + 1); | |
1321 | if (GET_CODE (tmp) == NOTE) | |
1322 | tmp = next_nonnote_insn (tmp); | |
4b523fc4 | 1323 | if (force_fallthru || insn == tmp) |
dbf08f94 | 1324 | make_edge (edge_cache, bb, BASIC_BLOCK (i + 1), EDGE_FALLTHRU); |
e881bb1b | 1325 | } |
dc2ede84 | 1326 | } |
dbf08f94 | 1327 | |
dbf08f94 RH |
1328 | if (edge_cache) |
1329 | sbitmap_vector_free (edge_cache); | |
e881bb1b RH |
1330 | } |
1331 | ||
1332 | /* Create an edge between two basic blocks. FLAGS are auxiliary information | |
1333 | about the edge that is accumulated between calls. */ | |
1334 | ||
69732dcb | 1335 | void |
dbf08f94 RH |
1336 | make_edge (edge_cache, src, dst, flags) |
1337 | sbitmap *edge_cache; | |
e881bb1b RH |
1338 | basic_block src, dst; |
1339 | int flags; | |
1340 | { | |
dbf08f94 | 1341 | int use_edge_cache; |
e881bb1b RH |
1342 | edge e; |
1343 | ||
dbf08f94 RH |
1344 | /* Don't bother with edge cache for ENTRY or EXIT; there aren't that |
1345 | many edges to them, and we didn't allocate memory for it. */ | |
1346 | use_edge_cache = (edge_cache | |
1347 | && src != ENTRY_BLOCK_PTR | |
1348 | && dst != EXIT_BLOCK_PTR); | |
e881bb1b | 1349 | |
dbf08f94 | 1350 | /* Make sure we don't add duplicate edges. */ |
25e4379f MM |
1351 | switch (use_edge_cache) |
1352 | { | |
1353 | default: | |
1354 | /* Quick test for non-existance of the edge. */ | |
1355 | if (! TEST_BIT (edge_cache[src->index], dst->index)) | |
1356 | break; | |
1357 | ||
1358 | /* The edge exists; early exit if no work to do. */ | |
1359 | if (flags == 0) | |
1360 | return; | |
1361 | ||
1362 | /* FALLTHRU */ | |
1363 | case 0: | |
1364 | for (e = src->succ; e; e = e->succ_next) | |
1365 | if (e->dest == dst) | |
1366 | { | |
1367 | e->flags |= flags; | |
1368 | return; | |
1369 | } | |
1370 | break; | |
1371 | } | |
e881bb1b RH |
1372 | |
1373 | e = (edge) xcalloc (1, sizeof (*e)); | |
d3a923ee | 1374 | n_edges++; |
e881bb1b RH |
1375 | |
1376 | e->succ_next = src->succ; | |
1377 | e->pred_next = dst->pred; | |
1378 | e->src = src; | |
1379 | e->dest = dst; | |
1380 | e->flags = flags; | |
1381 | ||
1382 | src->succ = e; | |
1383 | dst->pred = e; | |
dbf08f94 RH |
1384 | |
1385 | if (use_edge_cache) | |
1386 | SET_BIT (edge_cache[src->index], dst->index); | |
e881bb1b RH |
1387 | } |
1388 | ||
1389 | /* Create an edge from a basic block to a label. */ | |
1390 | ||
1391 | static void | |
dbf08f94 RH |
1392 | make_label_edge (edge_cache, src, label, flags) |
1393 | sbitmap *edge_cache; | |
e881bb1b RH |
1394 | basic_block src; |
1395 | rtx label; | |
1396 | int flags; | |
1397 | { | |
1398 | if (GET_CODE (label) != CODE_LABEL) | |
1399 | abort (); | |
1400 | ||
1401 | /* If the label was never emitted, this insn is junk, but avoid a | |
1402 | crash trying to refer to BLOCK_FOR_INSN (label). This can happen | |
1403 | as a result of a syntax error and a diagnostic has already been | |
1404 | printed. */ | |
1405 | ||
1406 | if (INSN_UID (label) == 0) | |
1407 | return; | |
1408 | ||
dbf08f94 | 1409 | make_edge (edge_cache, src, BLOCK_FOR_INSN (label), flags); |
e881bb1b | 1410 | } |
e6cfb550 | 1411 | |
336a6399 RH |
1412 | /* Create the edges generated by INSN in REGION. */ |
1413 | ||
1414 | static void | |
52a11cbf | 1415 | make_eh_edge (edge_cache, src, insn) |
dbf08f94 | 1416 | sbitmap *edge_cache; |
336a6399 RH |
1417 | basic_block src; |
1418 | rtx insn; | |
336a6399 | 1419 | { |
52a11cbf RH |
1420 | int is_call = (GET_CODE (insn) == CALL_INSN ? EDGE_ABNORMAL_CALL : 0); |
1421 | rtx handlers, i; | |
336a6399 | 1422 | |
52a11cbf | 1423 | handlers = reachable_handlers (insn); |
336a6399 | 1424 | |
52a11cbf RH |
1425 | for (i = handlers; i; i = XEXP (i, 1)) |
1426 | make_label_edge (edge_cache, src, XEXP (i, 0), | |
1427 | EDGE_ABNORMAL | EDGE_EH | is_call); | |
336a6399 | 1428 | |
52a11cbf | 1429 | free_INSN_LIST_list (&handlers); |
336a6399 RH |
1430 | } |
1431 | ||
e881bb1b | 1432 | /* Identify critical edges and set the bits appropriately. */ |
336a6399 | 1433 | |
e881bb1b RH |
1434 | static void |
1435 | mark_critical_edges () | |
1436 | { | |
1437 | int i, n = n_basic_blocks; | |
1438 | basic_block bb; | |
1439 | ||
1440 | /* We begin with the entry block. This is not terribly important now, | |
1441 | but could be if a front end (Fortran) implemented alternate entry | |
1442 | points. */ | |
1443 | bb = ENTRY_BLOCK_PTR; | |
1444 | i = -1; | |
1445 | ||
1446 | while (1) | |
e6cfb550 | 1447 | { |
e881bb1b RH |
1448 | edge e; |
1449 | ||
1450 | /* (1) Critical edges must have a source with multiple successors. */ | |
1451 | if (bb->succ && bb->succ->succ_next) | |
1452 | { | |
c9bacfdb | 1453 | for (e = bb->succ; e; e = e->succ_next) |
e881bb1b RH |
1454 | { |
1455 | /* (2) Critical edges must have a destination with multiple | |
1456 | predecessors. Note that we know there is at least one | |
1457 | predecessor -- the edge we followed to get here. */ | |
1458 | if (e->dest->pred->pred_next) | |
1459 | e->flags |= EDGE_CRITICAL; | |
1460 | else | |
1461 | e->flags &= ~EDGE_CRITICAL; | |
1462 | } | |
1463 | } | |
1464 | else | |
1465 | { | |
c9bacfdb | 1466 | for (e = bb->succ; e; e = e->succ_next) |
e881bb1b RH |
1467 | e->flags &= ~EDGE_CRITICAL; |
1468 | } | |
1469 | ||
1470 | if (++i >= n) | |
1471 | break; | |
1472 | bb = BASIC_BLOCK (i); | |
e6cfb550 | 1473 | } |
e881bb1b RH |
1474 | } |
1475 | \f | |
c586192c MH |
1476 | /* Split a block BB after insn INSN creating a new fallthru edge. |
1477 | Return the new edge. Note that to keep other parts of the compiler happy, | |
1478 | this function renumbers all the basic blocks so that the new | |
1479 | one has a number one greater than the block split. */ | |
1480 | ||
1481 | edge | |
1482 | split_block (bb, insn) | |
1483 | basic_block bb; | |
1484 | rtx insn; | |
1485 | { | |
1486 | basic_block new_bb; | |
1487 | edge new_edge; | |
1488 | edge e; | |
1489 | rtx bb_note; | |
1490 | int i, j; | |
1491 | ||
c586192c MH |
1492 | /* There is no point splitting the block after its end. */ |
1493 | if (bb->end == insn) | |
1494 | return 0; | |
1495 | ||
1496 | /* Create the new structures. */ | |
1f8f4a0b | 1497 | new_bb = (basic_block) obstack_alloc (&flow_obstack, sizeof (*new_bb)); |
c586192c MH |
1498 | new_edge = (edge) xcalloc (1, sizeof (*new_edge)); |
1499 | n_edges++; | |
1500 | ||
1501 | memset (new_bb, 0, sizeof (*new_bb)); | |
1502 | ||
1503 | new_bb->head = NEXT_INSN (insn); | |
1504 | new_bb->end = bb->end; | |
1505 | bb->end = insn; | |
1506 | ||
1507 | new_bb->succ = bb->succ; | |
1508 | bb->succ = new_edge; | |
1509 | new_bb->pred = new_edge; | |
1510 | new_bb->count = bb->count; | |
1511 | new_bb->loop_depth = bb->loop_depth; | |
1512 | ||
1513 | new_edge->src = bb; | |
1514 | new_edge->dest = new_bb; | |
1515 | new_edge->flags = EDGE_FALLTHRU; | |
1516 | new_edge->probability = REG_BR_PROB_BASE; | |
1517 | new_edge->count = bb->count; | |
1518 | ||
1519 | /* Redirect the src of the successor edges of bb to point to new_bb. */ | |
1520 | for (e = new_bb->succ; e; e = e->succ_next) | |
1521 | e->src = new_bb; | |
21c7361e | 1522 | |
c586192c MH |
1523 | /* Place the new block just after the block being split. */ |
1524 | VARRAY_GROW (basic_block_info, ++n_basic_blocks); | |
1525 | ||
1526 | /* Some parts of the compiler expect blocks to be number in | |
1527 | sequential order so insert the new block immediately after the | |
1528 | block being split.. */ | |
1529 | j = bb->index; | |
1530 | for (i = n_basic_blocks - 1; i > j + 1; --i) | |
1531 | { | |
1532 | basic_block tmp = BASIC_BLOCK (i - 1); | |
1533 | BASIC_BLOCK (i) = tmp; | |
1534 | tmp->index = i; | |
1535 | } | |
1536 | ||
1537 | BASIC_BLOCK (i) = new_bb; | |
1538 | new_bb->index = i; | |
1539 | ||
a686dbf8 JH |
1540 | if (GET_CODE (new_bb->head) == CODE_LABEL) |
1541 | { | |
1542 | /* Create the basic block note. */ | |
1543 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, | |
1544 | new_bb->head); | |
1545 | NOTE_BASIC_BLOCK (bb_note) = new_bb; | |
1546 | } | |
1547 | else | |
1548 | { | |
1549 | /* Create the basic block note. */ | |
1550 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, | |
1551 | new_bb->head); | |
1552 | NOTE_BASIC_BLOCK (bb_note) = new_bb; | |
1553 | new_bb->head = bb_note; | |
1554 | } | |
c586192c MH |
1555 | |
1556 | update_bb_for_insn (new_bb); | |
1557 | ||
1558 | if (bb->global_live_at_start) | |
1559 | { | |
1f8f4a0b MM |
1560 | new_bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); |
1561 | new_bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
c586192c MH |
1562 | COPY_REG_SET (new_bb->global_live_at_end, bb->global_live_at_end); |
1563 | ||
1564 | /* We now have to calculate which registers are live at the end | |
1565 | of the split basic block and at the start of the new basic | |
1566 | block. Start with those registers that are known to be live | |
1567 | at the end of the original basic block and get | |
1568 | propagate_block to determine which registers are live. */ | |
1569 | COPY_REG_SET (new_bb->global_live_at_start, bb->global_live_at_end); | |
7dfc0fbe | 1570 | propagate_block (new_bb, new_bb->global_live_at_start, NULL, NULL, 0); |
21c7361e | 1571 | COPY_REG_SET (bb->global_live_at_end, |
c586192c MH |
1572 | new_bb->global_live_at_start); |
1573 | } | |
1574 | ||
1575 | return new_edge; | |
1576 | } | |
1577 | ||
1578 | ||
e881bb1b | 1579 | /* Split a (typically critical) edge. Return the new block. |
c9bacfdb | 1580 | Abort on abnormal edges. |
e881bb1b RH |
1581 | |
1582 | ??? The code generally expects to be called on critical edges. | |
c9bacfdb | 1583 | The case of a block ending in an unconditional jump to a |
e881bb1b RH |
1584 | block with multiple predecessors is not handled optimally. */ |
1585 | ||
1586 | basic_block | |
1587 | split_edge (edge_in) | |
1588 | edge edge_in; | |
1589 | { | |
1590 | basic_block old_pred, bb, old_succ; | |
1591 | edge edge_out; | |
1592 | rtx bb_note; | |
abb14ef5 | 1593 | int i, j; |
c9bacfdb | 1594 | |
e881bb1b RH |
1595 | /* Abnormal edges cannot be split. */ |
1596 | if ((edge_in->flags & EDGE_ABNORMAL) != 0) | |
1597 | abort (); | |
1598 | ||
1599 | old_pred = edge_in->src; | |
1600 | old_succ = edge_in->dest; | |
1601 | ||
1602 | /* Remove the existing edge from the destination's pred list. */ | |
1603 | { | |
1604 | edge *pp; | |
1605 | for (pp = &old_succ->pred; *pp != edge_in; pp = &(*pp)->pred_next) | |
1606 | continue; | |
1607 | *pp = edge_in->pred_next; | |
1e7d57a3 | 1608 | edge_in->pred_next = NULL; |
e881bb1b RH |
1609 | } |
1610 | ||
1611 | /* Create the new structures. */ | |
1f8f4a0b | 1612 | bb = (basic_block) obstack_alloc (&flow_obstack, sizeof (*bb)); |
e881bb1b | 1613 | edge_out = (edge) xcalloc (1, sizeof (*edge_out)); |
d3a923ee | 1614 | n_edges++; |
e881bb1b RH |
1615 | |
1616 | memset (bb, 0, sizeof (*bb)); | |
e881bb1b RH |
1617 | |
1618 | /* ??? This info is likely going to be out of date very soon. */ | |
e881bb1b RH |
1619 | if (old_succ->global_live_at_start) |
1620 | { | |
1f8f4a0b MM |
1621 | bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); |
1622 | bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
e881bb1b RH |
1623 | COPY_REG_SET (bb->global_live_at_start, old_succ->global_live_at_start); |
1624 | COPY_REG_SET (bb->global_live_at_end, old_succ->global_live_at_start); | |
1625 | } | |
e881bb1b RH |
1626 | |
1627 | /* Wire them up. */ | |
1628 | bb->pred = edge_in; | |
1629 | bb->succ = edge_out; | |
51891abe | 1630 | bb->count = edge_in->count; |
1e7d57a3 | 1631 | |
e881bb1b | 1632 | edge_in->dest = bb; |
1e7d57a3 JH |
1633 | edge_in->flags &= ~EDGE_CRITICAL; |
1634 | ||
1635 | edge_out->pred_next = old_succ->pred; | |
1636 | edge_out->succ_next = NULL; | |
e881bb1b RH |
1637 | edge_out->src = bb; |
1638 | edge_out->dest = old_succ; | |
1e7d57a3 JH |
1639 | edge_out->flags = EDGE_FALLTHRU; |
1640 | edge_out->probability = REG_BR_PROB_BASE; | |
51891abe | 1641 | edge_out->count = edge_in->count; |
1e7d57a3 JH |
1642 | |
1643 | old_succ->pred = edge_out; | |
e881bb1b RH |
1644 | |
1645 | /* Tricky case -- if there existed a fallthru into the successor | |
1646 | (and we're not it) we must add a new unconditional jump around | |
c9bacfdb | 1647 | the new block we're actually interested in. |
e881bb1b RH |
1648 | |
1649 | Further, if that edge is critical, this means a second new basic | |
1650 | block must be created to hold it. In order to simplify correct | |
1651 | insn placement, do this before we touch the existing basic block | |
1652 | ordering for the block we were really wanting. */ | |
1653 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1654 | { | |
1655 | edge e; | |
c9bacfdb | 1656 | for (e = edge_out->pred_next; e; e = e->pred_next) |
e881bb1b RH |
1657 | if (e->flags & EDGE_FALLTHRU) |
1658 | break; | |
1659 | ||
1660 | if (e) | |
1661 | { | |
1662 | basic_block jump_block; | |
1663 | rtx pos; | |
1664 | ||
d9d4fb43 AS |
1665 | if ((e->flags & EDGE_CRITICAL) == 0 |
1666 | && e->src != ENTRY_BLOCK_PTR) | |
e881bb1b RH |
1667 | { |
1668 | /* Non critical -- we can simply add a jump to the end | |
1669 | of the existing predecessor. */ | |
1670 | jump_block = e->src; | |
e881bb1b RH |
1671 | } |
1672 | else | |
1673 | { | |
1674 | /* We need a new block to hold the jump. The simplest | |
1675 | way to do the bulk of the work here is to recursively | |
1676 | call ourselves. */ | |
1677 | jump_block = split_edge (e); | |
1678 | e = jump_block->succ; | |
e881bb1b RH |
1679 | } |
1680 | ||
1e7d57a3 JH |
1681 | /* Now add the jump insn ... */ |
1682 | pos = emit_jump_insn_after (gen_jump (old_succ->head), | |
1683 | jump_block->end); | |
e881bb1b | 1684 | jump_block->end = pos; |
414094de JL |
1685 | if (basic_block_for_insn) |
1686 | set_block_for_insn (pos, jump_block); | |
e881bb1b | 1687 | emit_barrier_after (pos); |
1e7d57a3 JH |
1688 | |
1689 | /* ... let jump know that label is in use, ... */ | |
a8688bd6 | 1690 | JUMP_LABEL (pos) = old_succ->head; |
1e7d57a3 | 1691 | ++LABEL_NUSES (old_succ->head); |
c9bacfdb | 1692 | |
e881bb1b RH |
1693 | /* ... and clear fallthru on the outgoing edge. */ |
1694 | e->flags &= ~EDGE_FALLTHRU; | |
1695 | ||
1696 | /* Continue splitting the interesting edge. */ | |
1697 | } | |
1698 | } | |
1699 | ||
1700 | /* Place the new block just in front of the successor. */ | |
1701 | VARRAY_GROW (basic_block_info, ++n_basic_blocks); | |
abb14ef5 AM |
1702 | if (old_succ == EXIT_BLOCK_PTR) |
1703 | j = n_basic_blocks - 1; | |
1704 | else | |
1705 | j = old_succ->index; | |
1706 | for (i = n_basic_blocks - 1; i > j; --i) | |
e881bb1b RH |
1707 | { |
1708 | basic_block tmp = BASIC_BLOCK (i - 1); | |
1709 | BASIC_BLOCK (i) = tmp; | |
1710 | tmp->index = i; | |
1711 | } | |
1712 | BASIC_BLOCK (i) = bb; | |
1713 | bb->index = i; | |
1714 | ||
c9bacfdb | 1715 | /* Create the basic block note. |
9aa137f3 JL |
1716 | |
1717 | Where we place the note can have a noticable impact on the generated | |
c9bacfdb | 1718 | code. Consider this cfg: |
9aa137f3 JL |
1719 | |
1720 | E | |
1721 | | | |
1722 | 0 | |
1723 | / \ | |
1724 | +->1-->2--->E | |
1725 | | | | |
1726 | +--+ | |
1727 | ||
1728 | If we need to insert an insn on the edge from block 0 to block 1, | |
1729 | we want to ensure the instructions we insert are outside of any | |
1730 | loop notes that physically sit between block 0 and block 1. Otherwise | |
1731 | we confuse the loop optimizer into thinking the loop is a phony. */ | |
1732 | if (old_succ != EXIT_BLOCK_PTR | |
1733 | && PREV_INSN (old_succ->head) | |
1734 | && GET_CODE (PREV_INSN (old_succ->head)) == NOTE | |
1735 | && NOTE_LINE_NUMBER (PREV_INSN (old_succ->head)) == NOTE_INSN_LOOP_BEG) | |
1736 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, | |
1737 | PREV_INSN (old_succ->head)); | |
1738 | else if (old_succ != EXIT_BLOCK_PTR) | |
abb14ef5 AM |
1739 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, old_succ->head); |
1740 | else | |
1741 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
e881bb1b RH |
1742 | NOTE_BASIC_BLOCK (bb_note) = bb; |
1743 | bb->head = bb->end = bb_note; | |
1744 | ||
1745 | /* Not quite simple -- for non-fallthru edges, we must adjust the | |
1746 | predecessor's jump instruction to target our new block. */ | |
1747 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1748 | { | |
1749 | rtx tmp, insn = old_pred->end; | |
1750 | rtx old_label = old_succ->head; | |
1751 | rtx new_label = gen_label_rtx (); | |
1752 | ||
1753 | if (GET_CODE (insn) != JUMP_INSN) | |
1754 | abort (); | |
1755 | ||
1756 | /* ??? Recognize a tablejump and adjust all matching cases. */ | |
1757 | if ((tmp = JUMP_LABEL (insn)) != NULL_RTX | |
1758 | && (tmp = NEXT_INSN (tmp)) != NULL_RTX | |
1759 | && GET_CODE (tmp) == JUMP_INSN | |
1760 | && (GET_CODE (PATTERN (tmp)) == ADDR_VEC | |
1761 | || GET_CODE (PATTERN (tmp)) == ADDR_DIFF_VEC)) | |
1762 | { | |
1763 | rtvec vec; | |
1764 | int j; | |
1765 | ||
1766 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) | |
1767 | vec = XVEC (PATTERN (tmp), 0); | |
1768 | else | |
1769 | vec = XVEC (PATTERN (tmp), 1); | |
1770 | ||
1771 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
1772 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
1773 | { | |
c9bacfdb | 1774 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (VOIDmode, new_label); |
e881bb1b RH |
1775 | --LABEL_NUSES (old_label); |
1776 | ++LABEL_NUSES (new_label); | |
1777 | } | |
506f9fbf RE |
1778 | |
1779 | /* Handle casesi dispatch insns */ | |
1780 | if ((tmp = single_set (insn)) != NULL | |
1781 | && SET_DEST (tmp) == pc_rtx | |
1782 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
1783 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF | |
1784 | && XEXP (XEXP (SET_SRC (tmp), 2), 0) == old_label) | |
1785 | { | |
c9bacfdb | 1786 | XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (VOIDmode, |
506f9fbf RE |
1787 | new_label); |
1788 | --LABEL_NUSES (old_label); | |
1789 | ++LABEL_NUSES (new_label); | |
1790 | } | |
e881bb1b RH |
1791 | } |
1792 | else | |
1793 | { | |
1794 | /* This would have indicated an abnormal edge. */ | |
1795 | if (computed_jump_p (insn)) | |
1796 | abort (); | |
1797 | ||
1798 | /* A return instruction can't be redirected. */ | |
1799 | if (returnjump_p (insn)) | |
1800 | abort (); | |
1801 | ||
1802 | /* If the insn doesn't go where we think, we're confused. */ | |
1803 | if (JUMP_LABEL (insn) != old_label) | |
1804 | abort (); | |
1805 | ||
9ba11d5a | 1806 | redirect_jump (insn, new_label, 0); |
e881bb1b RH |
1807 | } |
1808 | ||
1809 | emit_label_before (new_label, bb_note); | |
1810 | bb->head = new_label; | |
1811 | } | |
1812 | ||
e881bb1b RH |
1813 | return bb; |
1814 | } | |
1815 | ||
1816 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1817 | The new instructions and basic blocks (if any) will not appear in the | |
1818 | CFG until commit_edge_insertions is called. */ | |
1819 | ||
1820 | void | |
1821 | insert_insn_on_edge (pattern, e) | |
1822 | rtx pattern; | |
1823 | edge e; | |
1824 | { | |
1825 | /* We cannot insert instructions on an abnormal critical edge. | |
1826 | It will be easier to find the culprit if we die now. */ | |
1827 | if ((e->flags & (EDGE_ABNORMAL|EDGE_CRITICAL)) | |
1828 | == (EDGE_ABNORMAL|EDGE_CRITICAL)) | |
1829 | abort (); | |
1830 | ||
1831 | if (e->insns == NULL_RTX) | |
1832 | start_sequence (); | |
1833 | else | |
1834 | push_to_sequence (e->insns); | |
1835 | ||
1836 | emit_insn (pattern); | |
1837 | ||
1838 | e->insns = get_insns (); | |
c9bacfdb | 1839 | end_sequence (); |
e881bb1b RH |
1840 | } |
1841 | ||
1842 | /* Update the CFG for the instructions queued on edge E. */ | |
1843 | ||
1844 | static void | |
1845 | commit_one_edge_insertion (e) | |
1846 | edge e; | |
1847 | { | |
f5540cd4 | 1848 | rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last; |
e881bb1b RH |
1849 | basic_block bb; |
1850 | ||
19d3c25c RH |
1851 | /* Pull the insns off the edge now since the edge might go away. */ |
1852 | insns = e->insns; | |
1853 | e->insns = NULL_RTX; | |
1854 | ||
e881bb1b RH |
1855 | /* Figure out where to put these things. If the destination has |
1856 | one predecessor, insert there. Except for the exit block. */ | |
1857 | if (e->dest->pred->pred_next == NULL | |
1858 | && e->dest != EXIT_BLOCK_PTR) | |
1859 | { | |
1860 | bb = e->dest; | |
1861 | ||
1862 | /* Get the location correct wrt a code label, and "nice" wrt | |
1863 | a basic block note, and before everything else. */ | |
1864 | tmp = bb->head; | |
1865 | if (GET_CODE (tmp) == CODE_LABEL) | |
1866 | tmp = NEXT_INSN (tmp); | |
589ca5cb | 1867 | if (NOTE_INSN_BASIC_BLOCK_P (tmp)) |
e881bb1b RH |
1868 | tmp = NEXT_INSN (tmp); |
1869 | if (tmp == bb->head) | |
1870 | before = tmp; | |
1871 | else | |
1872 | after = PREV_INSN (tmp); | |
1873 | } | |
c9bacfdb | 1874 | |
e881bb1b RH |
1875 | /* If the source has one successor and the edge is not abnormal, |
1876 | insert there. Except for the entry block. */ | |
1877 | else if ((e->flags & EDGE_ABNORMAL) == 0 | |
1878 | && e->src->succ->succ_next == NULL | |
1879 | && e->src != ENTRY_BLOCK_PTR) | |
1880 | { | |
1881 | bb = e->src; | |
08520ad8 JL |
1882 | /* It is possible to have a non-simple jump here. Consider a target |
1883 | where some forms of unconditional jumps clobber a register. This | |
c9bacfdb | 1884 | happens on the fr30 for example. |
08520ad8 JL |
1885 | |
1886 | We know this block has a single successor, so we can just emit | |
1887 | the queued insns before the jump. */ | |
e881bb1b RH |
1888 | if (GET_CODE (bb->end) == JUMP_INSN) |
1889 | { | |
e881bb1b RH |
1890 | before = bb->end; |
1891 | } | |
1892 | else | |
1893 | { | |
1894 | /* We'd better be fallthru, or we've lost track of what's what. */ | |
1895 | if ((e->flags & EDGE_FALLTHRU) == 0) | |
1896 | abort (); | |
1897 | ||
1898 | after = bb->end; | |
1899 | } | |
1900 | } | |
1901 | ||
1902 | /* Otherwise we must split the edge. */ | |
1903 | else | |
1904 | { | |
1905 | bb = split_edge (e); | |
1906 | after = bb->end; | |
1907 | } | |
1908 | ||
1909 | /* Now that we've found the spot, do the insertion. */ | |
a8688bd6 AM |
1910 | |
1911 | /* Set the new block number for these insns, if structure is allocated. */ | |
1912 | if (basic_block_for_insn) | |
1913 | { | |
1914 | rtx i; | |
19d3c25c | 1915 | for (i = insns; i != NULL_RTX; i = NEXT_INSN (i)) |
a8688bd6 AM |
1916 | set_block_for_insn (i, bb); |
1917 | } | |
1918 | ||
e881bb1b RH |
1919 | if (before) |
1920 | { | |
19d3c25c | 1921 | emit_insns_before (insns, before); |
e881bb1b | 1922 | if (before == bb->head) |
19d3c25c | 1923 | bb->head = insns; |
f5540cd4 RH |
1924 | |
1925 | last = prev_nonnote_insn (before); | |
e881bb1b RH |
1926 | } |
1927 | else | |
1928 | { | |
f5540cd4 | 1929 | last = emit_insns_after (insns, after); |
e881bb1b | 1930 | if (after == bb->end) |
f5540cd4 RH |
1931 | bb->end = last; |
1932 | } | |
19d3c25c | 1933 | |
f5540cd4 RH |
1934 | if (returnjump_p (last)) |
1935 | { | |
c9bacfdb | 1936 | /* ??? Remove all outgoing edges from BB and add one for EXIT. |
f5540cd4 RH |
1937 | This is not currently a problem because this only happens |
1938 | for the (single) epilogue, which already has a fallthru edge | |
1939 | to EXIT. */ | |
1940 | ||
1941 | e = bb->succ; | |
1942 | if (e->dest != EXIT_BLOCK_PTR | |
1943 | || e->succ_next != NULL | |
1944 | || (e->flags & EDGE_FALLTHRU) == 0) | |
1945 | abort (); | |
1946 | e->flags &= ~EDGE_FALLTHRU; | |
1947 | ||
1948 | emit_barrier_after (last); | |
1949 | bb->end = last; | |
1950 | ||
1951 | if (before) | |
1952 | flow_delete_insn (before); | |
e881bb1b | 1953 | } |
f5540cd4 RH |
1954 | else if (GET_CODE (last) == JUMP_INSN) |
1955 | abort (); | |
a686dbf8 | 1956 | find_sub_basic_blocks (bb); |
e881bb1b RH |
1957 | } |
1958 | ||
1959 | /* Update the CFG for all queued instructions. */ | |
1960 | ||
1961 | void | |
1962 | commit_edge_insertions () | |
1963 | { | |
1964 | int i; | |
1965 | basic_block bb; | |
1966 | ||
19d3c25c RH |
1967 | #ifdef ENABLE_CHECKING |
1968 | verify_flow_info (); | |
1969 | #endif | |
c9bacfdb | 1970 | |
e881bb1b RH |
1971 | i = -1; |
1972 | bb = ENTRY_BLOCK_PTR; | |
1973 | while (1) | |
1974 | { | |
1975 | edge e, next; | |
1976 | ||
c9bacfdb | 1977 | for (e = bb->succ; e; e = next) |
e881bb1b RH |
1978 | { |
1979 | next = e->succ_next; | |
1980 | if (e->insns) | |
1981 | commit_one_edge_insertion (e); | |
1982 | } | |
1983 | ||
1984 | if (++i >= n_basic_blocks) | |
1985 | break; | |
1986 | bb = BASIC_BLOCK (i); | |
1987 | } | |
1988 | } | |
0ab409ed MH |
1989 | |
1990 | /* Add fake edges to the function exit for any non constant calls in | |
1991 | the bitmap of blocks specified by BLOCKS or to the whole CFG if | |
1992 | BLOCKS is zero. Return the nuber of blocks that were split. */ | |
1993 | ||
1994 | int | |
1995 | flow_call_edges_add (blocks) | |
1996 | sbitmap blocks; | |
1997 | { | |
1998 | int i; | |
1999 | int blocks_split = 0; | |
2000 | int bb_num = 0; | |
2001 | basic_block *bbs; | |
2002 | ||
2003 | /* Map bb indicies into basic block pointers since split_block | |
2004 | will renumber the basic blocks. */ | |
2005 | ||
2006 | bbs = xmalloc (n_basic_blocks * sizeof (*bbs)); | |
2007 | ||
2008 | if (! blocks) | |
2009 | { | |
2010 | for (i = 0; i < n_basic_blocks; i++) | |
2011 | bbs[bb_num++] = BASIC_BLOCK (i); | |
2012 | } | |
2013 | else | |
2014 | { | |
2015 | EXECUTE_IF_SET_IN_SBITMAP (blocks, 0, i, | |
2016 | { | |
2017 | bbs[bb_num++] = BASIC_BLOCK (i); | |
2018 | }); | |
2019 | } | |
2020 | ||
2021 | ||
2022 | /* Now add fake edges to the function exit for any non constant | |
2023 | calls since there is no way that we can determine if they will | |
2024 | return or not... */ | |
2025 | ||
2026 | for (i = 0; i < bb_num; i++) | |
2027 | { | |
2028 | basic_block bb = bbs[i]; | |
2029 | rtx insn; | |
2030 | rtx prev_insn; | |
2031 | ||
2032 | for (insn = bb->end; ; insn = prev_insn) | |
2033 | { | |
2034 | prev_insn = PREV_INSN (insn); | |
2035 | if (GET_CODE (insn) == CALL_INSN && ! CONST_CALL_P (insn)) | |
2036 | { | |
2037 | edge e; | |
2038 | ||
2039 | /* Note that the following may create a new basic block | |
2040 | and renumber the existing basic blocks. */ | |
2041 | e = split_block (bb, insn); | |
2042 | if (e) | |
2043 | blocks_split++; | |
2044 | ||
2045 | make_edge (NULL, bb, EXIT_BLOCK_PTR, EDGE_FAKE); | |
2046 | } | |
2047 | if (insn == bb->head) | |
2048 | break; | |
2049 | } | |
2050 | } | |
2051 | ||
2052 | if (blocks_split) | |
2053 | verify_flow_info (); | |
2054 | ||
2055 | free (bbs); | |
2056 | return blocks_split; | |
2057 | } | |
e881bb1b RH |
2058 | \f |
2059 | /* Delete all unreachable basic blocks. */ | |
2060 | ||
2061 | static void | |
2062 | delete_unreachable_blocks () | |
2063 | { | |
2064 | basic_block *worklist, *tos; | |
e881bb1b RH |
2065 | edge e; |
2066 | int i, n; | |
2067 | ||
2068 | n = n_basic_blocks; | |
67289ea6 | 2069 | tos = worklist = (basic_block *) xmalloc (sizeof (basic_block) * n); |
e881bb1b RH |
2070 | |
2071 | /* Use basic_block->aux as a marker. Clear them all. */ | |
2072 | ||
2073 | for (i = 0; i < n; ++i) | |
2074 | BASIC_BLOCK (i)->aux = NULL; | |
2075 | ||
2076 | /* Add our starting points to the worklist. Almost always there will | |
2077 | be only one. It isn't inconcievable that we might one day directly | |
2078 | support Fortran alternate entry points. */ | |
2079 | ||
c9bacfdb | 2080 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) |
aa3d4bf9 RH |
2081 | { |
2082 | *tos++ = e->dest; | |
2083 | ||
2084 | /* Mark the block with a handy non-null value. */ | |
2085 | e->dest->aux = e; | |
2086 | } | |
c9bacfdb | 2087 | |
e881bb1b RH |
2088 | /* Iterate: find everything reachable from what we've already seen. */ |
2089 | ||
2090 | while (tos != worklist) | |
2091 | { | |
2092 | basic_block b = *--tos; | |
2093 | ||
c9bacfdb | 2094 | for (e = b->succ; e; e = e->succ_next) |
e881bb1b | 2095 | if (!e->dest->aux) |
aa3d4bf9 RH |
2096 | { |
2097 | *tos++ = e->dest; | |
2098 | e->dest->aux = e; | |
2099 | } | |
e881bb1b RH |
2100 | } |
2101 | ||
52a11cbf RH |
2102 | /* Delete all unreachable basic blocks. Count down so that we |
2103 | don't interfere with the block renumbering that happens in | |
2104 | flow_delete_block. */ | |
e881bb1b RH |
2105 | |
2106 | for (i = n - 1; i >= 0; --i) | |
2107 | { | |
2108 | basic_block b = BASIC_BLOCK (i); | |
2109 | ||
2110 | if (b->aux != NULL) | |
2111 | /* This block was found. Tidy up the mark. */ | |
2112 | b->aux = NULL; | |
2113 | else | |
52a11cbf | 2114 | flow_delete_block (b); |
e881bb1b RH |
2115 | } |
2116 | ||
5568fb48 | 2117 | tidy_fallthru_edges (); |
e881bb1b | 2118 | |
67289ea6 | 2119 | free (worklist); |
e881bb1b RH |
2120 | } |
2121 | ||
e881bb1b RH |
2122 | /* Return true if NOTE is not one of the ones that must be kept paired, |
2123 | so that we may simply delete them. */ | |
2124 | ||
2125 | static int | |
eeea333e | 2126 | can_delete_note_p (note) |
e881bb1b RH |
2127 | rtx note; |
2128 | { | |
2129 | return (NOTE_LINE_NUMBER (note) == NOTE_INSN_DELETED | |
2130 | || NOTE_LINE_NUMBER (note) == NOTE_INSN_BASIC_BLOCK); | |
2131 | } | |
2132 | ||
2133 | /* Unlink a chain of insns between START and FINISH, leaving notes | |
2134 | that must be paired. */ | |
2135 | ||
d3a923ee | 2136 | void |
5aabad00 | 2137 | flow_delete_insn_chain (start, finish) |
e881bb1b RH |
2138 | rtx start, finish; |
2139 | { | |
2140 | /* Unchain the insns one by one. It would be quicker to delete all | |
2141 | of these with a single unchaining, rather than one at a time, but | |
2142 | we need to keep the NOTE's. */ | |
2143 | ||
2144 | rtx next; | |
2145 | ||
2146 | while (1) | |
2147 | { | |
2148 | next = NEXT_INSN (start); | |
eeea333e RH |
2149 | if (GET_CODE (start) == NOTE && !can_delete_note_p (start)) |
2150 | ; | |
be1bb652 RH |
2151 | else if (GET_CODE (start) == CODE_LABEL |
2152 | && ! can_delete_label_p (start)) | |
2153 | { | |
2154 | const char *name = LABEL_NAME (start); | |
2155 | PUT_CODE (start, NOTE); | |
2156 | NOTE_LINE_NUMBER (start) = NOTE_INSN_DELETED_LABEL; | |
2157 | NOTE_SOURCE_FILE (start) = name; | |
2158 | } | |
eeea333e | 2159 | else |
e881bb1b RH |
2160 | next = flow_delete_insn (start); |
2161 | ||
2162 | if (start == finish) | |
2163 | break; | |
2164 | start = next; | |
2165 | } | |
2166 | } | |
2167 | ||
2168 | /* Delete the insns in a (non-live) block. We physically delete every | |
2169 | non-deleted-note insn, and update the flow graph appropriately. | |
2170 | ||
2171 | Return nonzero if we deleted an exception handler. */ | |
2172 | ||
2173 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
2174 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
2175 | ||
52294521 RH |
2176 | int |
2177 | flow_delete_block (b) | |
e881bb1b RH |
2178 | basic_block b; |
2179 | { | |
2180 | int deleted_handler = 0; | |
1519ae2c | 2181 | rtx insn, end, tmp; |
e881bb1b RH |
2182 | |
2183 | /* If the head of this block is a CODE_LABEL, then it might be the | |
2184 | label for an exception handler which can't be reached. | |
2185 | ||
2186 | We need to remove the label from the exception_handler_label list | |
3ad47811 MM |
2187 | and remove the associated NOTE_INSN_EH_REGION_BEG and |
2188 | NOTE_INSN_EH_REGION_END notes. */ | |
e881bb1b RH |
2189 | |
2190 | insn = b->head; | |
c9bacfdb | 2191 | |
312f6255 GK |
2192 | never_reached_warning (insn); |
2193 | ||
e881bb1b | 2194 | if (GET_CODE (insn) == CODE_LABEL) |
52a11cbf | 2195 | maybe_remove_eh_handler (insn); |
e881bb1b | 2196 | |
1519ae2c RH |
2197 | /* Include any jump table following the basic block. */ |
2198 | end = b->end; | |
2199 | if (GET_CODE (end) == JUMP_INSN | |
2200 | && (tmp = JUMP_LABEL (end)) != NULL_RTX | |
2201 | && (tmp = NEXT_INSN (tmp)) != NULL_RTX | |
2202 | && GET_CODE (tmp) == JUMP_INSN | |
2203 | && (GET_CODE (PATTERN (tmp)) == ADDR_VEC | |
2204 | || GET_CODE (PATTERN (tmp)) == ADDR_DIFF_VEC)) | |
2205 | end = tmp; | |
2206 | ||
2207 | /* Include any barrier that may follow the basic block. */ | |
1fa4609a | 2208 | tmp = next_nonnote_insn (end); |
1519ae2c RH |
2209 | if (tmp && GET_CODE (tmp) == BARRIER) |
2210 | end = tmp; | |
2211 | ||
2212 | /* Selectively delete the entire chain. */ | |
5aabad00 | 2213 | flow_delete_insn_chain (insn, end); |
e881bb1b | 2214 | |
c9bacfdb | 2215 | /* Remove the edges into and out of this block. Note that there may |
e881bb1b RH |
2216 | indeed be edges in, if we are removing an unreachable loop. */ |
2217 | { | |
2218 | edge e, next, *q; | |
2219 | ||
c9bacfdb | 2220 | for (e = b->pred; e; e = next) |
e881bb1b RH |
2221 | { |
2222 | for (q = &e->src->succ; *q != e; q = &(*q)->succ_next) | |
2223 | continue; | |
2224 | *q = e->succ_next; | |
2225 | next = e->pred_next; | |
d3a923ee | 2226 | n_edges--; |
e881bb1b RH |
2227 | free (e); |
2228 | } | |
c9bacfdb | 2229 | for (e = b->succ; e; e = next) |
e881bb1b RH |
2230 | { |
2231 | for (q = &e->dest->pred; *q != e; q = &(*q)->pred_next) | |
2232 | continue; | |
2233 | *q = e->pred_next; | |
2234 | next = e->succ_next; | |
d3a923ee | 2235 | n_edges--; |
e881bb1b RH |
2236 | free (e); |
2237 | } | |
2238 | ||
2239 | b->pred = NULL; | |
2240 | b->succ = NULL; | |
2241 | } | |
2242 | ||
2243 | /* Remove the basic block from the array, and compact behind it. */ | |
2244 | expunge_block (b); | |
2245 | ||
2246 | return deleted_handler; | |
2247 | } | |
2248 | ||
2249 | /* Remove block B from the basic block array and compact behind it. */ | |
2250 | ||
2251 | static void | |
2252 | expunge_block (b) | |
2253 | basic_block b; | |
2254 | { | |
2255 | int i, n = n_basic_blocks; | |
2256 | ||
2257 | for (i = b->index; i + 1 < n; ++i) | |
2258 | { | |
2259 | basic_block x = BASIC_BLOCK (i + 1); | |
2260 | BASIC_BLOCK (i) = x; | |
2261 | x->index = i; | |
2262 | } | |
2263 | ||
2264 | basic_block_info->num_elements--; | |
2265 | n_basic_blocks--; | |
2266 | } | |
2267 | ||
2268 | /* Delete INSN by patching it out. Return the next insn. */ | |
2269 | ||
69732dcb | 2270 | rtx |
e881bb1b RH |
2271 | flow_delete_insn (insn) |
2272 | rtx insn; | |
2273 | { | |
2274 | rtx prev = PREV_INSN (insn); | |
2275 | rtx next = NEXT_INSN (insn); | |
1519ae2c | 2276 | rtx note; |
e881bb1b RH |
2277 | |
2278 | PREV_INSN (insn) = NULL_RTX; | |
2279 | NEXT_INSN (insn) = NULL_RTX; | |
aa9e158d | 2280 | INSN_DELETED_P (insn) = 1; |
c9bacfdb | 2281 | |
e881bb1b RH |
2282 | if (prev) |
2283 | NEXT_INSN (prev) = next; | |
2284 | if (next) | |
2285 | PREV_INSN (next) = prev; | |
2286 | else | |
2287 | set_last_insn (prev); | |
e6cfb550 | 2288 | |
55a98783 JL |
2289 | if (GET_CODE (insn) == CODE_LABEL) |
2290 | remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels); | |
2291 | ||
e881bb1b RH |
2292 | /* If deleting a jump, decrement the use count of the label. Deleting |
2293 | the label itself should happen in the normal course of block merging. */ | |
f5540cd4 RH |
2294 | if (GET_CODE (insn) == JUMP_INSN |
2295 | && JUMP_LABEL (insn) | |
2296 | && GET_CODE (JUMP_LABEL (insn)) == CODE_LABEL) | |
e881bb1b RH |
2297 | LABEL_NUSES (JUMP_LABEL (insn))--; |
2298 | ||
1519ae2c | 2299 | /* Also if deleting an insn that references a label. */ |
f5540cd4 RH |
2300 | else if ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)) != NULL_RTX |
2301 | && GET_CODE (XEXP (note, 0)) == CODE_LABEL) | |
1519ae2c RH |
2302 | LABEL_NUSES (XEXP (note, 0))--; |
2303 | ||
e881bb1b | 2304 | return next; |
d7429b6a | 2305 | } |
8329b5ec | 2306 | |
e881bb1b RH |
2307 | /* True if a given label can be deleted. */ |
2308 | ||
c9bacfdb | 2309 | static int |
e881bb1b RH |
2310 | can_delete_label_p (label) |
2311 | rtx label; | |
dc2ede84 | 2312 | { |
e881bb1b | 2313 | rtx x; |
dc2ede84 | 2314 | |
e881bb1b RH |
2315 | if (LABEL_PRESERVE_P (label)) |
2316 | return 0; | |
421382ac | 2317 | |
c9bacfdb | 2318 | for (x = forced_labels; x; x = XEXP (x, 1)) |
e881bb1b RH |
2319 | if (label == XEXP (x, 0)) |
2320 | return 0; | |
c9bacfdb | 2321 | for (x = label_value_list; x; x = XEXP (x, 1)) |
e881bb1b RH |
2322 | if (label == XEXP (x, 0)) |
2323 | return 0; | |
c9bacfdb | 2324 | for (x = exception_handler_labels; x; x = XEXP (x, 1)) |
e881bb1b RH |
2325 | if (label == XEXP (x, 0)) |
2326 | return 0; | |
dc2ede84 | 2327 | |
abb3f0a9 | 2328 | /* User declared labels must be preserved. */ |
088e7160 | 2329 | if (LABEL_NAME (label) != 0) |
abb3f0a9 | 2330 | return 0; |
c9bacfdb | 2331 | |
e881bb1b RH |
2332 | return 1; |
2333 | } | |
421382ac | 2334 | |
be1bb652 RH |
2335 | static int |
2336 | tail_recursion_label_p (label) | |
2337 | rtx label; | |
2338 | { | |
2339 | rtx x; | |
2340 | ||
c9bacfdb | 2341 | for (x = tail_recursion_label_list; x; x = XEXP (x, 1)) |
be1bb652 RH |
2342 | if (label == XEXP (x, 0)) |
2343 | return 1; | |
2344 | ||
2345 | return 0; | |
2346 | } | |
2347 | ||
dc108b7a RH |
2348 | /* Blocks A and B are to be merged into a single block A. The insns |
2349 | are already contiguous, hence `nomove'. */ | |
2350 | ||
2351 | void | |
2352 | merge_blocks_nomove (a, b) | |
2353 | basic_block a, b; | |
2354 | { | |
2355 | edge e; | |
2356 | rtx b_head, b_end, a_end; | |
2357 | rtx del_first = NULL_RTX, del_last = NULL_RTX; | |
2358 | int b_empty = 0; | |
2359 | ||
2360 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
2361 | b_head = b->head; | |
2362 | b_end = b->end; | |
2363 | if (GET_CODE (b_head) == CODE_LABEL) | |
2364 | { | |
2365 | /* Detect basic blocks with nothing but a label. This can happen | |
2366 | in particular at the end of a function. */ | |
2367 | if (b_head == b_end) | |
2368 | b_empty = 1; | |
2369 | del_first = del_last = b_head; | |
2370 | b_head = NEXT_INSN (b_head); | |
2371 | } | |
2372 | ||
2373 | /* Delete the basic block note. */ | |
589ca5cb | 2374 | if (NOTE_INSN_BASIC_BLOCK_P (b_head)) |
dc108b7a RH |
2375 | { |
2376 | if (b_head == b_end) | |
2377 | b_empty = 1; | |
2378 | if (! del_last) | |
2379 | del_first = b_head; | |
2380 | del_last = b_head; | |
2381 | b_head = NEXT_INSN (b_head); | |
2382 | } | |
2383 | ||
2384 | /* If there was a jump out of A, delete it. */ | |
2385 | a_end = a->end; | |
2386 | if (GET_CODE (a_end) == JUMP_INSN) | |
2387 | { | |
2388 | rtx prev; | |
2389 | ||
8416f80a | 2390 | for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev)) |
7171b491 RH |
2391 | if (GET_CODE (prev) != NOTE |
2392 | || NOTE_LINE_NUMBER (prev) == NOTE_INSN_BASIC_BLOCK | |
2393 | || prev == a->head) | |
8416f80a | 2394 | break; |
dc108b7a RH |
2395 | |
2396 | del_first = a_end; | |
2397 | ||
2398 | #ifdef HAVE_cc0 | |
2399 | /* If this was a conditional jump, we need to also delete | |
2400 | the insn that set cc0. */ | |
2401 | if (prev && sets_cc0_p (prev)) | |
2402 | { | |
c9bacfdb | 2403 | rtx tmp = prev; |
dc108b7a RH |
2404 | prev = prev_nonnote_insn (prev); |
2405 | if (!prev) | |
2406 | prev = a->head; | |
2407 | del_first = tmp; | |
2408 | } | |
2409 | #endif | |
2410 | ||
2411 | a_end = prev; | |
2412 | } | |
abb9a4c5 RH |
2413 | else if (GET_CODE (NEXT_INSN (a_end)) == BARRIER) |
2414 | del_first = NEXT_INSN (a_end); | |
dc108b7a RH |
2415 | |
2416 | /* Delete everything marked above as well as crap that might be | |
2417 | hanging out between the two blocks. */ | |
2418 | flow_delete_insn_chain (del_first, del_last); | |
2419 | ||
2420 | /* Normally there should only be one successor of A and that is B, but | |
2421 | partway though the merge of blocks for conditional_execution we'll | |
2422 | be merging a TEST block with THEN and ELSE successors. Free the | |
2423 | whole lot of them and hope the caller knows what they're doing. */ | |
2424 | while (a->succ) | |
2425 | remove_edge (a->succ); | |
2426 | ||
2427 | /* Adjust the edges out of B for the new owner. */ | |
c9bacfdb | 2428 | for (e = b->succ; e; e = e->succ_next) |
dc108b7a RH |
2429 | e->src = a; |
2430 | a->succ = b->succ; | |
2431 | ||
2432 | /* B hasn't quite yet ceased to exist. Attempt to prevent mishap. */ | |
2433 | b->pred = b->succ = NULL; | |
2434 | ||
2435 | /* Reassociate the insns of B with A. */ | |
2436 | if (!b_empty) | |
2437 | { | |
2438 | if (basic_block_for_insn) | |
2439 | { | |
2440 | BLOCK_FOR_INSN (b_head) = a; | |
2441 | while (b_head != b_end) | |
2442 | { | |
2443 | b_head = NEXT_INSN (b_head); | |
2444 | BLOCK_FOR_INSN (b_head) = a; | |
2445 | } | |
2446 | } | |
2447 | a_end = b_end; | |
2448 | } | |
2449 | a->end = a_end; | |
2450 | ||
2451 | expunge_block (b); | |
2452 | } | |
2453 | ||
558389e3 JL |
2454 | /* Blocks A and B are to be merged into a single block. A has no incoming |
2455 | fallthru edge, so it can be moved before B without adding or modifying | |
2456 | any jumps (aside from the jump from A to B). */ | |
2457 | ||
2458 | static int | |
336a6399 | 2459 | merge_blocks_move_predecessor_nojumps (a, b) |
558389e3 JL |
2460 | basic_block a, b; |
2461 | { | |
93cba993 | 2462 | rtx start, end, barrier; |
ee7b8369 | 2463 | int index; |
558389e3 JL |
2464 | |
2465 | start = a->head; | |
2466 | end = a->end; | |
558389e3 | 2467 | |
558389e3 | 2468 | barrier = next_nonnote_insn (end); |
be1bb652 RH |
2469 | if (GET_CODE (barrier) != BARRIER) |
2470 | abort (); | |
2471 | flow_delete_insn (barrier); | |
558389e3 JL |
2472 | |
2473 | /* Move block and loop notes out of the chain so that we do not | |
2474 | disturb their order. | |
2475 | ||
2476 | ??? A better solution would be to squeeze out all the non-nested notes | |
2477 | and adjust the block trees appropriately. Even better would be to have | |
2478 | a tighter connection between block trees and rtl so that this is not | |
2479 | necessary. */ | |
2480 | start = squeeze_notes (start, end); | |
2481 | ||
2482 | /* Scramble the insn chain. */ | |
93cba993 RH |
2483 | if (end != PREV_INSN (b->head)) |
2484 | reorder_insns (start, end, PREV_INSN (b->head)); | |
558389e3 | 2485 | |
336a6399 RH |
2486 | if (rtl_dump_file) |
2487 | { | |
2488 | fprintf (rtl_dump_file, "Moved block %d before %d and merged.\n", | |
2489 | a->index, b->index); | |
2490 | } | |
2491 | ||
ee7b8369 RE |
2492 | /* Swap the records for the two blocks around. Although we are deleting B, |
2493 | A is now where B was and we want to compact the BB array from where | |
2494 | A used to be. */ | |
c9bacfdb KH |
2495 | BASIC_BLOCK (a->index) = b; |
2496 | BASIC_BLOCK (b->index) = a; | |
ee7b8369 RE |
2497 | index = a->index; |
2498 | a->index = b->index; | |
2499 | b->index = index; | |
c9bacfdb | 2500 | |
ee7b8369 RE |
2501 | /* Now blocks A and B are contiguous. Merge them. */ |
2502 | merge_blocks_nomove (a, b); | |
2503 | ||
558389e3 JL |
2504 | return 1; |
2505 | } | |
2506 | ||
2507 | /* Blocks A and B are to be merged into a single block. B has no outgoing | |
2508 | fallthru edge, so it can be moved after A without adding or modifying | |
2509 | any jumps (aside from the jump from A to B). */ | |
2510 | ||
2511 | static int | |
336a6399 | 2512 | merge_blocks_move_successor_nojumps (a, b) |
558389e3 JL |
2513 | basic_block a, b; |
2514 | { | |
93cba993 | 2515 | rtx start, end, barrier; |
558389e3 JL |
2516 | |
2517 | start = b->head; | |
2518 | end = b->end; | |
be1bb652 RH |
2519 | barrier = NEXT_INSN (end); |
2520 | ||
2521 | /* Recognize a jump table following block B. */ | |
2522 | if (GET_CODE (barrier) == CODE_LABEL | |
2523 | && NEXT_INSN (barrier) | |
2524 | && GET_CODE (NEXT_INSN (barrier)) == JUMP_INSN | |
2525 | && (GET_CODE (PATTERN (NEXT_INSN (barrier))) == ADDR_VEC | |
2526 | || GET_CODE (PATTERN (NEXT_INSN (barrier))) == ADDR_DIFF_VEC)) | |
2527 | { | |
2528 | end = NEXT_INSN (barrier); | |
2529 | barrier = NEXT_INSN (end); | |
2530 | } | |
558389e3 | 2531 | |
be1bb652 RH |
2532 | /* There had better have been a barrier there. Delete it. */ |
2533 | if (GET_CODE (barrier) != BARRIER) | |
2534 | abort (); | |
2535 | flow_delete_insn (barrier); | |
558389e3 JL |
2536 | |
2537 | /* Move block and loop notes out of the chain so that we do not | |
2538 | disturb their order. | |
2539 | ||
2540 | ??? A better solution would be to squeeze out all the non-nested notes | |
2541 | and adjust the block trees appropriately. Even better would be to have | |
2542 | a tighter connection between block trees and rtl so that this is not | |
2543 | necessary. */ | |
2544 | start = squeeze_notes (start, end); | |
2545 | ||
2546 | /* Scramble the insn chain. */ | |
93cba993 | 2547 | reorder_insns (start, end, a->end); |
558389e3 JL |
2548 | |
2549 | /* Now blocks A and B are contiguous. Merge them. */ | |
2550 | merge_blocks_nomove (a, b); | |
336a6399 RH |
2551 | |
2552 | if (rtl_dump_file) | |
2553 | { | |
2554 | fprintf (rtl_dump_file, "Moved block %d after %d and merged.\n", | |
2555 | b->index, a->index); | |
2556 | } | |
2557 | ||
558389e3 JL |
2558 | return 1; |
2559 | } | |
2560 | ||
c9bacfdb | 2561 | /* Attempt to merge basic blocks that are potentially non-adjacent. |
e881bb1b | 2562 | Return true iff the attempt succeeded. */ |
dc2ede84 | 2563 | |
dc2ede84 | 2564 | static int |
e881bb1b RH |
2565 | merge_blocks (e, b, c) |
2566 | edge e; | |
2567 | basic_block b, c; | |
dc2ede84 | 2568 | { |
be1bb652 RH |
2569 | /* If C has a tail recursion label, do not merge. There is no |
2570 | edge recorded from the call_placeholder back to this label, as | |
2571 | that would make optimize_sibling_and_tail_recursive_calls more | |
2572 | complex for no gain. */ | |
2573 | if (GET_CODE (c->head) == CODE_LABEL | |
2574 | && tail_recursion_label_p (c->head)) | |
2575 | return 0; | |
2576 | ||
e881bb1b | 2577 | /* If B has a fallthru edge to C, no need to move anything. */ |
336a6399 | 2578 | if (e->flags & EDGE_FALLTHRU) |
e881bb1b | 2579 | { |
336a6399 | 2580 | merge_blocks_nomove (b, c); |
558389e3 | 2581 | |
336a6399 RH |
2582 | if (rtl_dump_file) |
2583 | { | |
2584 | fprintf (rtl_dump_file, "Merged %d and %d without moving.\n", | |
2585 | b->index, c->index); | |
2586 | } | |
e881bb1b | 2587 | |
336a6399 RH |
2588 | return 1; |
2589 | } | |
2590 | else | |
2591 | { | |
2592 | edge tmp_edge; | |
336a6399 RH |
2593 | int c_has_outgoing_fallthru; |
2594 | int b_has_incoming_fallthru; | |
e881bb1b | 2595 | |
336a6399 RH |
2596 | /* We must make sure to not munge nesting of exception regions, |
2597 | lexical blocks, and loop notes. | |
c9bacfdb | 2598 | |
336a6399 RH |
2599 | The first is taken care of by requiring that the active eh |
2600 | region at the end of one block always matches the active eh | |
2601 | region at the beginning of the next block. | |
c9bacfdb | 2602 | |
336a6399 | 2603 | The later two are taken care of by squeezing out all the notes. */ |
c9bacfdb | 2604 | |
336a6399 RH |
2605 | /* ??? A throw/catch edge (or any abnormal edge) should be rarely |
2606 | executed and we may want to treat blocks which have two out | |
2607 | edges, one normal, one abnormal as only having one edge for | |
2608 | block merging purposes. */ | |
558389e3 | 2609 | |
c9bacfdb | 2610 | for (tmp_edge = c->succ; tmp_edge; tmp_edge = tmp_edge->succ_next) |
558389e3 JL |
2611 | if (tmp_edge->flags & EDGE_FALLTHRU) |
2612 | break; | |
2613 | c_has_outgoing_fallthru = (tmp_edge != NULL); | |
2614 | ||
c9bacfdb | 2615 | for (tmp_edge = b->pred; tmp_edge; tmp_edge = tmp_edge->pred_next) |
558389e3 JL |
2616 | if (tmp_edge->flags & EDGE_FALLTHRU) |
2617 | break; | |
2618 | b_has_incoming_fallthru = (tmp_edge != NULL); | |
2619 | ||
52a11cbf RH |
2620 | /* If B does not have an incoming fallthru, then it can be moved |
2621 | immediately before C without introducing or modifying jumps. | |
2622 | C cannot be the first block, so we do not have to worry about | |
ff54d46b | 2623 | accessing a non-existent block. */ |
52a11cbf | 2624 | if (! b_has_incoming_fallthru) |
336a6399 RH |
2625 | return merge_blocks_move_predecessor_nojumps (b, c); |
2626 | ||
52a11cbf RH |
2627 | /* Otherwise, we're going to try to move C after B. If C does |
2628 | not have an outgoing fallthru, then it can be moved | |
2629 | immediately after B without introducing or modifying jumps. */ | |
2630 | if (! c_has_outgoing_fallthru) | |
2631 | return merge_blocks_move_successor_nojumps (b, c); | |
ff54d46b | 2632 | |
52a11cbf RH |
2633 | /* Otherwise, we'll need to insert an extra jump, and possibly |
2634 | a new block to contain it. */ | |
2635 | /* ??? Not implemented yet. */ | |
558389e3 | 2636 | |
336a6399 | 2637 | return 0; |
e881bb1b | 2638 | } |
336a6399 | 2639 | } |
dc2ede84 | 2640 | |
336a6399 | 2641 | /* Top level driver for merge_blocks. */ |
421382ac | 2642 | |
336a6399 RH |
2643 | static void |
2644 | try_merge_blocks () | |
2645 | { | |
2646 | int i; | |
2647 | ||
2648 | /* Attempt to merge blocks as made possible by edge removal. If a block | |
c9bacfdb | 2649 | has only one successor, and the successor has only one predecessor, |
336a6399 RH |
2650 | they may be combined. */ |
2651 | ||
c9bacfdb | 2652 | for (i = 0; i < n_basic_blocks;) |
336a6399 RH |
2653 | { |
2654 | basic_block c, b = BASIC_BLOCK (i); | |
2655 | edge s; | |
2656 | ||
2657 | /* A loop because chains of blocks might be combineable. */ | |
2658 | while ((s = b->succ) != NULL | |
2659 | && s->succ_next == NULL | |
2660 | && (s->flags & EDGE_EH) == 0 | |
2661 | && (c = s->dest) != EXIT_BLOCK_PTR | |
2662 | && c->pred->pred_next == NULL | |
2663 | /* If the jump insn has side effects, we can't kill the edge. */ | |
2664 | && (GET_CODE (b->end) != JUMP_INSN | |
2665 | || onlyjump_p (b->end)) | |
2666 | && merge_blocks (s, b, c)) | |
2667 | continue; | |
2668 | ||
2669 | /* Don't get confused by the index shift caused by deleting blocks. */ | |
2670 | i = b->index + 1; | |
2671 | } | |
e881bb1b | 2672 | } |
421382ac | 2673 | |
5568fb48 RH |
2674 | /* The given edge should potentially be a fallthru edge. If that is in |
2675 | fact true, delete the jump and barriers that are in the way. */ | |
e881bb1b | 2676 | |
dc108b7a | 2677 | void |
e881bb1b RH |
2678 | tidy_fallthru_edge (e, b, c) |
2679 | edge e; | |
2680 | basic_block b, c; | |
2681 | { | |
eeea333e | 2682 | rtx q; |
e881bb1b RH |
2683 | |
2684 | /* ??? In a late-running flow pass, other folks may have deleted basic | |
2685 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
2686 | and the target label. They ought to be chastized and fixed. | |
2687 | ||
eeea333e RH |
2688 | We can also wind up with a sequence of undeletable labels between |
2689 | one block and the next. | |
dc2ede84 | 2690 | |
eeea333e RH |
2691 | So search through a sequence of barriers, labels, and notes for |
2692 | the head of block C and assert that we really do fall through. */ | |
421382ac | 2693 | |
eeea333e | 2694 | if (next_real_insn (b->end) != next_real_insn (PREV_INSN (c->head))) |
e881bb1b | 2695 | return; |
421382ac | 2696 | |
e881bb1b RH |
2697 | /* Remove what will soon cease being the jump insn from the source block. |
2698 | If block B consisted only of this single jump, turn it into a deleted | |
2699 | note. */ | |
2700 | q = b->end; | |
56aba4a8 | 2701 | if (GET_CODE (q) == JUMP_INSN |
7f1c097d JH |
2702 | && onlyjump_p (q) |
2703 | && (any_uncondjump_p (q) | |
56aba4a8 | 2704 | || (b->succ == e && e->succ_next == NULL))) |
421382ac | 2705 | { |
86a1db60 RH |
2706 | #ifdef HAVE_cc0 |
2707 | /* If this was a conditional jump, we need to also delete | |
2708 | the insn that set cc0. */ | |
7f1c097d | 2709 | if (any_condjump_p (q) && sets_cc0_p (PREV_INSN (q))) |
86a1db60 RH |
2710 | q = PREV_INSN (q); |
2711 | #endif | |
2712 | ||
e881bb1b RH |
2713 | if (b->head == q) |
2714 | { | |
2715 | PUT_CODE (q, NOTE); | |
2716 | NOTE_LINE_NUMBER (q) = NOTE_INSN_DELETED; | |
2717 | NOTE_SOURCE_FILE (q) = 0; | |
2718 | } | |
e3f6ee23 | 2719 | else |
a8b94b40 RK |
2720 | { |
2721 | q = PREV_INSN (q); | |
2722 | ||
2723 | /* We don't want a block to end on a line-number note since that has | |
2724 | the potential of changing the code between -g and not -g. */ | |
2725 | while (GET_CODE (q) == NOTE && NOTE_LINE_NUMBER (q) >= 0) | |
2726 | q = PREV_INSN (q); | |
2727 | } | |
b578dbd7 RH |
2728 | |
2729 | b->end = q; | |
421382ac | 2730 | } |
421382ac | 2731 | |
e881bb1b | 2732 | /* Selectively unlink the sequence. */ |
86a1db60 | 2733 | if (q != PREV_INSN (c->head)) |
5aabad00 | 2734 | flow_delete_insn_chain (NEXT_INSN (q), PREV_INSN (c->head)); |
b7f7462b | 2735 | |
e881bb1b RH |
2736 | e->flags |= EDGE_FALLTHRU; |
2737 | } | |
dc2ede84 | 2738 | |
5568fb48 RH |
2739 | /* Fix up edges that now fall through, or rather should now fall through |
2740 | but previously required a jump around now deleted blocks. Simplify | |
2741 | the search by only examining blocks numerically adjacent, since this | |
2742 | is how find_basic_blocks created them. */ | |
2743 | ||
2744 | static void | |
2745 | tidy_fallthru_edges () | |
2746 | { | |
2747 | int i; | |
2748 | ||
2749 | for (i = 1; i < n_basic_blocks; ++i) | |
2750 | { | |
2751 | basic_block b = BASIC_BLOCK (i - 1); | |
2752 | basic_block c = BASIC_BLOCK (i); | |
2753 | edge s; | |
2754 | ||
2755 | /* We care about simple conditional or unconditional jumps with | |
2756 | a single successor. | |
2757 | ||
2758 | If we had a conditional branch to the next instruction when | |
2759 | find_basic_blocks was called, then there will only be one | |
2760 | out edge for the block which ended with the conditional | |
2761 | branch (since we do not create duplicate edges). | |
2762 | ||
2763 | Furthermore, the edge will be marked as a fallthru because we | |
2764 | merge the flags for the duplicate edges. So we do not want to | |
2765 | check that the edge is not a FALLTHRU edge. */ | |
2766 | if ((s = b->succ) != NULL | |
ad73b558 | 2767 | && ! (s->flags & EDGE_COMPLEX) |
5568fb48 RH |
2768 | && s->succ_next == NULL |
2769 | && s->dest == c | |
2770 | /* If the jump insn has side effects, we can't tidy the edge. */ | |
2771 | && (GET_CODE (b->end) != JUMP_INSN | |
2772 | || onlyjump_p (b->end))) | |
2773 | tidy_fallthru_edge (s, b, c); | |
2774 | } | |
2775 | } | |
d7429b6a | 2776 | \f |
5ece9746 | 2777 | /* Perform data flow analysis. |
7f8a79ba RH |
2778 | F is the first insn of the function; FLAGS is a set of PROP_* flags |
2779 | to be used in accumulating flow info. */ | |
5ece9746 JL |
2780 | |
2781 | void | |
7f8a79ba | 2782 | life_analysis (f, file, flags) |
5ece9746 | 2783 | rtx f; |
5ece9746 | 2784 | FILE *file; |
7f8a79ba | 2785 | int flags; |
5ece9746 | 2786 | { |
5ece9746 | 2787 | #ifdef ELIMINABLE_REGS |
47ee9bcb | 2788 | register int i; |
5ece9746 JL |
2789 | static struct {int from, to; } eliminables[] = ELIMINABLE_REGS; |
2790 | #endif | |
4e872036 | 2791 | |
5ece9746 JL |
2792 | /* Record which registers will be eliminated. We use this in |
2793 | mark_used_regs. */ | |
2794 | ||
2795 | CLEAR_HARD_REG_SET (elim_reg_set); | |
2796 | ||
2797 | #ifdef ELIMINABLE_REGS | |
b6a1cbae | 2798 | for (i = 0; i < (int) ARRAY_SIZE (eliminables); i++) |
5ece9746 JL |
2799 | SET_HARD_REG_BIT (elim_reg_set, eliminables[i].from); |
2800 | #else | |
2801 | SET_HARD_REG_BIT (elim_reg_set, FRAME_POINTER_REGNUM); | |
2802 | #endif | |
2803 | ||
d29c259b | 2804 | if (! optimize) |
b2262f4a | 2805 | flags &= ~(PROP_LOG_LINKS | PROP_AUTOINC); |
7790df19 | 2806 | |
3ea8083f JL |
2807 | /* The post-reload life analysis have (on a global basis) the same |
2808 | registers live as was computed by reload itself. elimination | |
2809 | Otherwise offsets and such may be incorrect. | |
2810 | ||
2811 | Reload will make some registers as live even though they do not | |
c9bacfdb | 2812 | appear in the rtl. |
61f286b6 RE |
2813 | |
2814 | We don't want to create new auto-incs after reload, since they | |
2815 | are unlikely to be useful and can cause problems with shared | |
2816 | stack slots. */ | |
3ea8083f | 2817 | if (reload_completed) |
61f286b6 | 2818 | flags &= ~(PROP_REG_INFO | PROP_AUTOINC); |
3ea8083f | 2819 | |
7f8a79ba | 2820 | /* We want alias analysis information for local dead store elimination. */ |
b2262f4a | 2821 | if (optimize && (flags & PROP_SCAN_DEAD_CODE)) |
7f8a79ba RH |
2822 | init_alias_analysis (); |
2823 | ||
3ea8083f JL |
2824 | /* Always remove no-op moves. Do this before other processing so |
2825 | that we don't have to keep re-scanning them. */ | |
2826 | delete_noop_moves (f); | |
2827 | ||
2828 | /* Some targets can emit simpler epilogues if they know that sp was | |
2829 | not ever modified during the function. After reload, of course, | |
2830 | we've already emitted the epilogue so there's no sense searching. */ | |
7790df19 | 2831 | if (! reload_completed) |
3ea8083f | 2832 | notice_stack_pointer_modification (f); |
c9bacfdb | 2833 | |
3ea8083f JL |
2834 | /* Allocate and zero out data structures that will record the |
2835 | data from lifetime analysis. */ | |
2836 | allocate_reg_life_data (); | |
2837 | allocate_bb_life_data (); | |
7790df19 | 2838 | |
3ea8083f JL |
2839 | /* Find the set of registers live on function exit. */ |
2840 | mark_regs_live_at_end (EXIT_BLOCK_PTR->global_live_at_start); | |
2841 | ||
2842 | /* "Update" life info from zero. It'd be nice to begin the | |
2843 | relaxation with just the exit and noreturn blocks, but that set | |
2844 | is not immediately handy. */ | |
c8082519 RH |
2845 | |
2846 | if (flags & PROP_REG_INFO) | |
c9bacfdb | 2847 | memset (regs_ever_live, 0, sizeof (regs_ever_live)); |
693d9e2f | 2848 | update_life_info (NULL, UPDATE_LIFE_GLOBAL, flags); |
3ea8083f JL |
2849 | |
2850 | /* Clean up. */ | |
b2262f4a | 2851 | if (optimize && (flags & PROP_SCAN_DEAD_CODE)) |
7f8a79ba | 2852 | end_alias_analysis (); |
db3a887b | 2853 | |
5ece9746 JL |
2854 | if (file) |
2855 | dump_flow_info (file); | |
2856 | ||
2857 | free_basic_block_vars (1); | |
2858 | } | |
2859 | ||
d3a923ee RH |
2860 | /* A subroutine of verify_wide_reg, called through for_each_rtx. |
2861 | Search for REGNO. If found, abort if it is not wider than word_mode. */ | |
2862 | ||
2863 | static int | |
2864 | verify_wide_reg_1 (px, pregno) | |
2865 | rtx *px; | |
2866 | void *pregno; | |
2867 | { | |
2868 | rtx x = *px; | |
770ae6cc | 2869 | unsigned int regno = *(int *) pregno; |
d3a923ee RH |
2870 | |
2871 | if (GET_CODE (x) == REG && REGNO (x) == regno) | |
2872 | { | |
2873 | if (GET_MODE_BITSIZE (GET_MODE (x)) <= BITS_PER_WORD) | |
2874 | abort (); | |
2875 | return 1; | |
2876 | } | |
2877 | return 0; | |
2878 | } | |
2879 | ||
2880 | /* A subroutine of verify_local_live_at_start. Search through insns | |
2881 | between HEAD and END looking for register REGNO. */ | |
2882 | ||
2883 | static void | |
2884 | verify_wide_reg (regno, head, end) | |
2885 | int regno; | |
2886 | rtx head, end; | |
2887 | { | |
2888 | while (1) | |
2889 | { | |
2c3c49de | 2890 | if (INSN_P (head) |
d3a923ee RH |
2891 | && for_each_rtx (&PATTERN (head), verify_wide_reg_1, ®no)) |
2892 | return; | |
2893 | if (head == end) | |
2894 | break; | |
2895 | head = NEXT_INSN (head); | |
2896 | } | |
2897 | ||
2898 | /* We didn't find the register at all. Something's way screwy. */ | |
f9b697bf BS |
2899 | if (rtl_dump_file) |
2900 | fprintf (rtl_dump_file, "Aborting in verify_wide_reg; reg %d\n", regno); | |
2901 | print_rtl_and_abort (); | |
d3a923ee RH |
2902 | } |
2903 | ||
2904 | /* A subroutine of update_life_info. Verify that there are no untoward | |
2905 | changes in live_at_start during a local update. */ | |
2906 | ||
2907 | static void | |
2908 | verify_local_live_at_start (new_live_at_start, bb) | |
2909 | regset new_live_at_start; | |
2910 | basic_block bb; | |
2911 | { | |
2912 | if (reload_completed) | |
2913 | { | |
2914 | /* After reload, there are no pseudos, nor subregs of multi-word | |
2915 | registers. The regsets should exactly match. */ | |
2916 | if (! REG_SET_EQUAL_P (new_live_at_start, bb->global_live_at_start)) | |
f9b697bf BS |
2917 | { |
2918 | if (rtl_dump_file) | |
2919 | { | |
2920 | fprintf (rtl_dump_file, | |
2921 | "live_at_start mismatch in bb %d, aborting\n", | |
2922 | bb->index); | |
2923 | debug_bitmap_file (rtl_dump_file, bb->global_live_at_start); | |
2924 | debug_bitmap_file (rtl_dump_file, new_live_at_start); | |
2925 | } | |
2926 | print_rtl_and_abort (); | |
2927 | } | |
d3a923ee RH |
2928 | } |
2929 | else | |
2930 | { | |
2931 | int i; | |
2932 | ||
2933 | /* Find the set of changed registers. */ | |
2934 | XOR_REG_SET (new_live_at_start, bb->global_live_at_start); | |
2935 | ||
2936 | EXECUTE_IF_SET_IN_REG_SET (new_live_at_start, 0, i, | |
2937 | { | |
c762163e | 2938 | /* No registers should die. */ |
d3a923ee | 2939 | if (REGNO_REG_SET_P (bb->global_live_at_start, i)) |
f9b697bf BS |
2940 | { |
2941 | if (rtl_dump_file) | |
2942 | fprintf (rtl_dump_file, | |
2943 | "Register %d died unexpectedly in block %d\n", i, | |
2944 | bb->index); | |
2945 | print_rtl_and_abort (); | |
2946 | } | |
2947 | ||
c762163e R |
2948 | /* Verify that the now-live register is wider than word_mode. */ |
2949 | verify_wide_reg (i, bb->head, bb->end); | |
d3a923ee RH |
2950 | }); |
2951 | } | |
2952 | } | |
2953 | ||
3ea8083f | 2954 | /* Updates life information starting with the basic blocks set in BLOCKS. |
693d9e2f | 2955 | If BLOCKS is null, consider it to be the universal set. |
c9bacfdb | 2956 | |
693d9e2f RH |
2957 | If EXTENT is UPDATE_LIFE_LOCAL, such as after splitting or peepholeing, |
2958 | we are only expecting local modifications to basic blocks. If we find | |
2959 | extra registers live at the beginning of a block, then we either killed | |
d3a923ee RH |
2960 | useful data, or we have a broken split that wants data not provided. |
2961 | If we find registers removed from live_at_start, that means we have | |
2962 | a broken peephole that is killing a register it shouldn't. | |
2963 | ||
2964 | ??? This is not true in one situation -- when a pre-reload splitter | |
2965 | generates subregs of a multi-word pseudo, current life analysis will | |
49c3bb12 RH |
2966 | lose the kill. So we _can_ have a pseudo go live. How irritating. |
2967 | ||
62828c00 RH |
2968 | Including PROP_REG_INFO does not properly refresh regs_ever_live |
2969 | unless the caller resets it to zero. */ | |
d3a923ee RH |
2970 | |
2971 | void | |
49c3bb12 | 2972 | update_life_info (blocks, extent, prop_flags) |
d3a923ee | 2973 | sbitmap blocks; |
715e7fbc | 2974 | enum update_life_extent extent; |
49c3bb12 | 2975 | int prop_flags; |
d3a923ee RH |
2976 | { |
2977 | regset tmp; | |
ee25a7a5 | 2978 | regset_head tmp_head; |
d3a923ee RH |
2979 | int i; |
2980 | ||
ee25a7a5 | 2981 | tmp = INITIALIZE_REG_SET (tmp_head); |
d3a923ee RH |
2982 | |
2983 | /* For a global update, we go through the relaxation process again. */ | |
715e7fbc RH |
2984 | if (extent != UPDATE_LIFE_LOCAL) |
2985 | { | |
49c3bb12 RH |
2986 | calculate_global_regs_live (blocks, blocks, |
2987 | prop_flags & PROP_SCAN_DEAD_CODE); | |
715e7fbc RH |
2988 | |
2989 | /* If asked, remove notes from the blocks we'll update. */ | |
2990 | if (extent == UPDATE_LIFE_GLOBAL_RM_NOTES) | |
2991 | count_or_remove_death_notes (blocks, 1); | |
2992 | } | |
d3a923ee | 2993 | |
693d9e2f | 2994 | if (blocks) |
d3a923ee | 2995 | { |
693d9e2f RH |
2996 | EXECUTE_IF_SET_IN_SBITMAP (blocks, 0, i, |
2997 | { | |
2998 | basic_block bb = BASIC_BLOCK (i); | |
2999 | ||
3000 | COPY_REG_SET (tmp, bb->global_live_at_end); | |
7dfc0fbe | 3001 | propagate_block (bb, tmp, NULL, NULL, prop_flags); |
693d9e2f RH |
3002 | |
3003 | if (extent == UPDATE_LIFE_LOCAL) | |
3004 | verify_local_live_at_start (tmp, bb); | |
3005 | }); | |
3006 | } | |
3007 | else | |
3008 | { | |
3009 | for (i = n_basic_blocks - 1; i >= 0; --i) | |
3010 | { | |
3011 | basic_block bb = BASIC_BLOCK (i); | |
d3a923ee | 3012 | |
693d9e2f | 3013 | COPY_REG_SET (tmp, bb->global_live_at_end); |
7dfc0fbe | 3014 | propagate_block (bb, tmp, NULL, NULL, prop_flags); |
d3a923ee | 3015 | |
693d9e2f RH |
3016 | if (extent == UPDATE_LIFE_LOCAL) |
3017 | verify_local_live_at_start (tmp, bb); | |
3018 | } | |
3019 | } | |
d3a923ee RH |
3020 | |
3021 | FREE_REG_SET (tmp); | |
3ea8083f JL |
3022 | |
3023 | if (prop_flags & PROP_REG_INFO) | |
3024 | { | |
3025 | /* The only pseudos that are live at the beginning of the function | |
3026 | are those that were not set anywhere in the function. local-alloc | |
3027 | doesn't know how to handle these correctly, so mark them as not | |
3028 | local to any one basic block. */ | |
3029 | EXECUTE_IF_SET_IN_REG_SET (ENTRY_BLOCK_PTR->global_live_at_end, | |
3030 | FIRST_PSEUDO_REGISTER, i, | |
3031 | { REG_BASIC_BLOCK (i) = REG_BLOCK_GLOBAL; }); | |
3032 | ||
c9bacfdb | 3033 | /* We have a problem with any pseudoreg that lives across the setjmp. |
3ea8083f JL |
3034 | ANSI says that if a user variable does not change in value between |
3035 | the setjmp and the longjmp, then the longjmp preserves it. This | |
3036 | includes longjmp from a place where the pseudo appears dead. | |
3037 | (In principle, the value still exists if it is in scope.) | |
3038 | If the pseudo goes in a hard reg, some other value may occupy | |
3039 | that hard reg where this pseudo is dead, thus clobbering the pseudo. | |
3040 | Conclusion: such a pseudo must not go in a hard reg. */ | |
3041 | EXECUTE_IF_SET_IN_REG_SET (regs_live_at_setjmp, | |
3042 | FIRST_PSEUDO_REGISTER, i, | |
3043 | { | |
3044 | if (regno_reg_rtx[i] != 0) | |
3045 | { | |
3046 | REG_LIVE_LENGTH (i) = -1; | |
3047 | REG_BASIC_BLOCK (i) = REG_BLOCK_UNKNOWN; | |
3048 | } | |
3049 | }); | |
3050 | } | |
d3a923ee RH |
3051 | } |
3052 | ||
5ece9746 JL |
3053 | /* Free the variables allocated by find_basic_blocks. |
3054 | ||
e881bb1b | 3055 | KEEP_HEAD_END_P is non-zero if basic_block_info is not to be freed. */ |
5ece9746 JL |
3056 | |
3057 | void | |
3058 | free_basic_block_vars (keep_head_end_p) | |
3059 | int keep_head_end_p; | |
3060 | { | |
e881bb1b | 3061 | if (basic_block_for_insn) |
5ece9746 | 3062 | { |
e881bb1b RH |
3063 | VARRAY_FREE (basic_block_for_insn); |
3064 | basic_block_for_insn = NULL; | |
5ece9746 JL |
3065 | } |
3066 | ||
e881bb1b | 3067 | if (! keep_head_end_p) |
5ece9746 | 3068 | { |
e881bb1b RH |
3069 | clear_edges (); |
3070 | VARRAY_FREE (basic_block_info); | |
3071 | n_basic_blocks = 0; | |
359da67d RH |
3072 | |
3073 | ENTRY_BLOCK_PTR->aux = NULL; | |
3074 | ENTRY_BLOCK_PTR->global_live_at_end = NULL; | |
3075 | EXIT_BLOCK_PTR->aux = NULL; | |
3076 | EXIT_BLOCK_PTR->global_live_at_start = NULL; | |
5ece9746 JL |
3077 | } |
3078 | } | |
3079 | ||
dc2ede84 | 3080 | /* Return nonzero if the destination of SET equals the source. */ |
c9bacfdb | 3081 | |
dc2ede84 BS |
3082 | static int |
3083 | set_noop_p (set) | |
3084 | rtx set; | |
3085 | { | |
3086 | rtx src = SET_SRC (set); | |
3087 | rtx dst = SET_DEST (set); | |
3ea8083f JL |
3088 | |
3089 | if (GET_CODE (src) == SUBREG && GET_CODE (dst) == SUBREG) | |
3090 | { | |
ddef6bc7 | 3091 | if (SUBREG_BYTE (src) != SUBREG_BYTE (dst)) |
3ea8083f JL |
3092 | return 0; |
3093 | src = SUBREG_REG (src); | |
3094 | dst = SUBREG_REG (dst); | |
3095 | } | |
3096 | ||
3097 | return (GET_CODE (src) == REG && GET_CODE (dst) == REG | |
3098 | && REGNO (src) == REGNO (dst)); | |
dc2ede84 BS |
3099 | } |
3100 | ||
3101 | /* Return nonzero if an insn consists only of SETs, each of which only sets a | |
3102 | value to itself. */ | |
c9bacfdb | 3103 | |
dc2ede84 BS |
3104 | static int |
3105 | noop_move_p (insn) | |
3106 | rtx insn; | |
3107 | { | |
3108 | rtx pat = PATTERN (insn); | |
3109 | ||
3110 | /* Insns carrying these notes are useful later on. */ | |
3111 | if (find_reg_note (insn, REG_EQUAL, NULL_RTX)) | |
3112 | return 0; | |
3113 | ||
3114 | if (GET_CODE (pat) == SET && set_noop_p (pat)) | |
3115 | return 1; | |
3116 | ||
3117 | if (GET_CODE (pat) == PARALLEL) | |
3118 | { | |
3119 | int i; | |
3120 | /* If nothing but SETs of registers to themselves, | |
3121 | this insn can also be deleted. */ | |
3122 | for (i = 0; i < XVECLEN (pat, 0); i++) | |
3123 | { | |
3124 | rtx tem = XVECEXP (pat, 0, i); | |
3125 | ||
3126 | if (GET_CODE (tem) == USE | |
3127 | || GET_CODE (tem) == CLOBBER) | |
3128 | continue; | |
3129 | ||
3130 | if (GET_CODE (tem) != SET || ! set_noop_p (tem)) | |
3131 | return 0; | |
3132 | } | |
3133 | ||
3134 | return 1; | |
3135 | } | |
3136 | return 0; | |
3137 | } | |
3138 | ||
3ea8083f JL |
3139 | /* Delete any insns that copy a register to itself. */ |
3140 | ||
3141 | static void | |
3142 | delete_noop_moves (f) | |
3143 | rtx f; | |
3144 | { | |
3145 | rtx insn; | |
3146 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
3147 | { | |
3148 | if (GET_CODE (insn) == INSN && noop_move_p (insn)) | |
3149 | { | |
3150 | PUT_CODE (insn, NOTE); | |
3151 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
3152 | NOTE_SOURCE_FILE (insn) = 0; | |
3153 | } | |
3154 | } | |
3155 | } | |
3156 | ||
3157 | /* Determine if the stack pointer is constant over the life of the function. | |
3158 | Only useful before prologues have been emitted. */ | |
3159 | ||
fdb8a883 | 3160 | static void |
3ea8083f | 3161 | notice_stack_pointer_modification_1 (x, pat, data) |
fdb8a883 JW |
3162 | rtx x; |
3163 | rtx pat ATTRIBUTE_UNUSED; | |
84832317 | 3164 | void *data ATTRIBUTE_UNUSED; |
fdb8a883 JW |
3165 | { |
3166 | if (x == stack_pointer_rtx | |
3167 | /* The stack pointer is only modified indirectly as the result | |
3168 | of a push until later in flow. See the comments in rtl.texi | |
3169 | regarding Embedded Side-Effects on Addresses. */ | |
3170 | || (GET_CODE (x) == MEM | |
0bf7d71a | 3171 | && GET_RTX_CLASS (GET_CODE (XEXP (x, 0))) == 'a' |
fdb8a883 JW |
3172 | && XEXP (XEXP (x, 0), 0) == stack_pointer_rtx)) |
3173 | current_function_sp_is_unchanging = 0; | |
3174 | } | |
3175 | ||
dc2ede84 | 3176 | static void |
3ea8083f | 3177 | notice_stack_pointer_modification (f) |
dc2ede84 BS |
3178 | rtx f; |
3179 | { | |
3180 | rtx insn; | |
3ea8083f JL |
3181 | |
3182 | /* Assume that the stack pointer is unchanging if alloca hasn't | |
3183 | been used. */ | |
3184 | current_function_sp_is_unchanging = !current_function_calls_alloca; | |
3185 | if (! current_function_sp_is_unchanging) | |
3186 | return; | |
3187 | ||
dc2ede84 BS |
3188 | for (insn = f; insn; insn = NEXT_INSN (insn)) |
3189 | { | |
2c3c49de | 3190 | if (INSN_P (insn)) |
dc2ede84 | 3191 | { |
3ea8083f JL |
3192 | /* Check if insn modifies the stack pointer. */ |
3193 | note_stores (PATTERN (insn), notice_stack_pointer_modification_1, | |
3194 | NULL); | |
3195 | if (! current_function_sp_is_unchanging) | |
3196 | return; | |
dc2ede84 BS |
3197 | } |
3198 | } | |
3199 | } | |
3200 | ||
d3a923ee RH |
3201 | /* Mark a register in SET. Hard registers in large modes get all |
3202 | of their component registers set as well. */ | |
c9bacfdb | 3203 | |
d3a923ee | 3204 | static void |
c13fde05 | 3205 | mark_reg (reg, xset) |
d3a923ee | 3206 | rtx reg; |
c13fde05 | 3207 | void *xset; |
d3a923ee | 3208 | { |
c13fde05 | 3209 | regset set = (regset) xset; |
d3a923ee RH |
3210 | int regno = REGNO (reg); |
3211 | ||
c13fde05 RH |
3212 | if (GET_MODE (reg) == BLKmode) |
3213 | abort (); | |
3214 | ||
d3a923ee RH |
3215 | SET_REGNO_REG_SET (set, regno); |
3216 | if (regno < FIRST_PSEUDO_REGISTER) | |
3217 | { | |
3218 | int n = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
3219 | while (--n > 0) | |
3220 | SET_REGNO_REG_SET (set, regno + n); | |
3221 | } | |
3222 | } | |
3223 | ||
dc2ede84 BS |
3224 | /* Mark those regs which are needed at the end of the function as live |
3225 | at the end of the last basic block. */ | |
c9bacfdb | 3226 | |
dc2ede84 BS |
3227 | static void |
3228 | mark_regs_live_at_end (set) | |
3229 | regset set; | |
3230 | { | |
3231 | int i; | |
d3a923ee | 3232 | |
e881bb1b RH |
3233 | /* If exiting needs the right stack value, consider the stack pointer |
3234 | live at the end of the function. */ | |
d3a923ee RH |
3235 | if ((HAVE_epilogue && reload_completed) |
3236 | || ! EXIT_IGNORE_STACK | |
dc2ede84 BS |
3237 | || (! FRAME_POINTER_REQUIRED |
3238 | && ! current_function_calls_alloca | |
fdb8a883 JW |
3239 | && flag_omit_frame_pointer) |
3240 | || current_function_sp_is_unchanging) | |
e881bb1b RH |
3241 | { |
3242 | SET_REGNO_REG_SET (set, STACK_POINTER_REGNUM); | |
3243 | } | |
dc2ede84 | 3244 | |
e881bb1b | 3245 | /* Mark the frame pointer if needed at the end of the function. If |
dc2ede84 BS |
3246 | we end up eliminating it, it will be removed from the live list |
3247 | of each basic block by reload. */ | |
3248 | ||
e4b8a413 JW |
3249 | if (! reload_completed || frame_pointer_needed) |
3250 | { | |
3251 | SET_REGNO_REG_SET (set, FRAME_POINTER_REGNUM); | |
dc2ede84 | 3252 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
2a3e384f RH |
3253 | /* If they are different, also mark the hard frame pointer as live. */ |
3254 | if (! LOCAL_REGNO (HARD_FRAME_POINTER_REGNUM)) | |
3255 | SET_REGNO_REG_SET (set, HARD_FRAME_POINTER_REGNUM); | |
c9bacfdb | 3256 | #endif |
e4b8a413 | 3257 | } |
dc2ede84 | 3258 | |
d3a923ee RH |
3259 | #ifndef PIC_OFFSET_TABLE_REG_CALL_CLOBBERED |
3260 | /* Many architectures have a GP register even without flag_pic. | |
3261 | Assume the pic register is not in use, or will be handled by | |
3262 | other means, if it is not fixed. */ | |
848e0190 JH |
3263 | if (PIC_OFFSET_TABLE_REGNUM != INVALID_REGNUM |
3264 | && fixed_regs[PIC_OFFSET_TABLE_REGNUM]) | |
d3a923ee | 3265 | SET_REGNO_REG_SET (set, PIC_OFFSET_TABLE_REGNUM); |
d3a923ee RH |
3266 | #endif |
3267 | ||
e881bb1b | 3268 | /* Mark all global registers, and all registers used by the epilogue |
dc2ede84 BS |
3269 | as being live at the end of the function since they may be |
3270 | referenced by our caller. */ | |
3271 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
2a3e384f | 3272 | if (global_regs[i] || EPILOGUE_USES (i)) |
dc2ede84 | 3273 | SET_REGNO_REG_SET (set, i); |
e881bb1b | 3274 | |
d3a923ee RH |
3275 | if (HAVE_epilogue && reload_completed) |
3276 | { | |
52a11cbf | 3277 | /* Mark all call-saved registers that we actually used. */ |
d3a923ee | 3278 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) |
2a3e384f | 3279 | if (regs_ever_live[i] && ! call_used_regs[i] && ! LOCAL_REGNO (i)) |
d3a923ee RH |
3280 | SET_REGNO_REG_SET (set, i); |
3281 | } | |
3282 | ||
52a11cbf RH |
3283 | #ifdef EH_RETURN_DATA_REGNO |
3284 | /* Mark the registers that will contain data for the handler. */ | |
3285 | if (reload_completed && current_function_calls_eh_return) | |
3286 | for (i = 0; ; ++i) | |
3287 | { | |
3288 | unsigned regno = EH_RETURN_DATA_REGNO(i); | |
3289 | if (regno == INVALID_REGNUM) | |
3290 | break; | |
3291 | SET_REGNO_REG_SET (set, regno); | |
3292 | } | |
3293 | #endif | |
3294 | #ifdef EH_RETURN_STACKADJ_RTX | |
3295 | if ((! HAVE_epilogue || ! reload_completed) | |
3296 | && current_function_calls_eh_return) | |
3297 | { | |
3298 | rtx tmp = EH_RETURN_STACKADJ_RTX; | |
3299 | if (tmp && REG_P (tmp)) | |
3300 | mark_reg (tmp, set); | |
3301 | } | |
3302 | #endif | |
3303 | #ifdef EH_RETURN_HANDLER_RTX | |
3304 | if ((! HAVE_epilogue || ! reload_completed) | |
3305 | && current_function_calls_eh_return) | |
3306 | { | |
3307 | rtx tmp = EH_RETURN_HANDLER_RTX; | |
3308 | if (tmp && REG_P (tmp)) | |
3309 | mark_reg (tmp, set); | |
3310 | } | |
3311 | #endif | |
3312 | ||
d3a923ee | 3313 | /* Mark function return value. */ |
c13fde05 | 3314 | diddle_return_value (mark_reg, set); |
dc2ede84 BS |
3315 | } |
3316 | ||
4e872036 AS |
3317 | /* Callback function for for_each_successor_phi. DATA is a regset. |
3318 | Sets the SRC_REGNO, the regno of the phi alternative for phi node | |
3319 | INSN, in the regset. */ | |
3320 | ||
3321 | static int | |
3322 | set_phi_alternative_reg (insn, dest_regno, src_regno, data) | |
3323 | rtx insn ATTRIBUTE_UNUSED; | |
3324 | int dest_regno ATTRIBUTE_UNUSED; | |
3325 | int src_regno; | |
3326 | void *data; | |
3327 | { | |
3328 | regset live = (regset) data; | |
3329 | SET_REGNO_REG_SET (live, src_regno); | |
3330 | return 0; | |
3331 | } | |
3332 | ||
d3a923ee | 3333 | /* Propagate global life info around the graph of basic blocks. Begin |
c9bacfdb | 3334 | considering blocks with their corresponding bit set in BLOCKS_IN. |
693d9e2f RH |
3335 | If BLOCKS_IN is null, consider it the universal set. |
3336 | ||
d3a923ee RH |
3337 | BLOCKS_OUT is set for every block that was changed. */ |
3338 | ||
3339 | static void | |
3340 | calculate_global_regs_live (blocks_in, blocks_out, flags) | |
3341 | sbitmap blocks_in, blocks_out; | |
3342 | int flags; | |
3343 | { | |
3344 | basic_block *queue, *qhead, *qtail, *qend; | |
ad73b558 RH |
3345 | regset tmp, new_live_at_end, call_used; |
3346 | regset_head tmp_head, call_used_head; | |
ee25a7a5 | 3347 | regset_head new_live_at_end_head; |
d3a923ee RH |
3348 | int i; |
3349 | ||
ee25a7a5 MM |
3350 | tmp = INITIALIZE_REG_SET (tmp_head); |
3351 | new_live_at_end = INITIALIZE_REG_SET (new_live_at_end_head); | |
ad73b558 RH |
3352 | call_used = INITIALIZE_REG_SET (call_used_head); |
3353 | ||
3354 | /* Inconveniently, this is only redily available in hard reg set form. */ | |
3355 | for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i) | |
3356 | if (call_used_regs[i]) | |
3357 | SET_REGNO_REG_SET (call_used, i); | |
d3a923ee RH |
3358 | |
3359 | /* Create a worklist. Allocate an extra slot for ENTRY_BLOCK, and one | |
c9bacfdb | 3360 | because the `head == tail' style test for an empty queue doesn't |
d3a923ee | 3361 | work with a full queue. */ |
67289ea6 | 3362 | queue = (basic_block *) xmalloc ((n_basic_blocks + 2) * sizeof (*queue)); |
d3a923ee RH |
3363 | qtail = queue; |
3364 | qhead = qend = queue + n_basic_blocks + 2; | |
3365 | ||
3366 | /* Queue the blocks set in the initial mask. Do this in reverse block | |
c9bacfdb | 3367 | number order so that we are more likely for the first round to do |
d3a923ee | 3368 | useful work. We use AUX non-null to flag that the block is queued. */ |
693d9e2f | 3369 | if (blocks_in) |
d3a923ee | 3370 | { |
25e4379f MM |
3371 | /* Clear out the garbage that might be hanging out in bb->aux. */ |
3372 | for (i = n_basic_blocks - 1; i >= 0; --i) | |
3373 | BASIC_BLOCK (i)->aux = NULL; | |
3374 | ||
693d9e2f RH |
3375 | EXECUTE_IF_SET_IN_SBITMAP (blocks_in, 0, i, |
3376 | { | |
3377 | basic_block bb = BASIC_BLOCK (i); | |
3378 | *--qhead = bb; | |
3379 | bb->aux = bb; | |
3380 | }); | |
3381 | } | |
3382 | else | |
3383 | { | |
3384 | for (i = 0; i < n_basic_blocks; ++i) | |
3385 | { | |
3386 | basic_block bb = BASIC_BLOCK (i); | |
3387 | *--qhead = bb; | |
3388 | bb->aux = bb; | |
3389 | } | |
3390 | } | |
d3a923ee | 3391 | |
693d9e2f RH |
3392 | if (blocks_out) |
3393 | sbitmap_zero (blocks_out); | |
d3a923ee RH |
3394 | |
3395 | while (qhead != qtail) | |
3396 | { | |
3397 | int rescan, changed; | |
3398 | basic_block bb; | |
3399 | edge e; | |
3400 | ||
3401 | bb = *qhead++; | |
3402 | if (qhead == qend) | |
3403 | qhead = queue; | |
3404 | bb->aux = NULL; | |
3405 | ||
3406 | /* Begin by propogating live_at_start from the successor blocks. */ | |
3407 | CLEAR_REG_SET (new_live_at_end); | |
c9bacfdb | 3408 | for (e = bb->succ; e; e = e->succ_next) |
d3a923ee RH |
3409 | { |
3410 | basic_block sb = e->dest; | |
ad73b558 RH |
3411 | |
3412 | /* Call-clobbered registers die across exception and call edges. */ | |
3413 | /* ??? Abnormal call edges ignored for the moment, as this gets | |
3414 | confused by sibling call edges, which crashes reg-stack. */ | |
3415 | if (e->flags & EDGE_EH) | |
3416 | { | |
3417 | bitmap_operation (tmp, sb->global_live_at_start, | |
3418 | call_used, BITMAP_AND_COMPL); | |
3419 | IOR_REG_SET (new_live_at_end, tmp); | |
3420 | } | |
3421 | else | |
3422 | IOR_REG_SET (new_live_at_end, sb->global_live_at_start); | |
d3a923ee RH |
3423 | } |
3424 | ||
f846e0de RH |
3425 | /* The all-important stack pointer must always be live. */ |
3426 | SET_REGNO_REG_SET (new_live_at_end, STACK_POINTER_REGNUM); | |
3427 | ||
39c39be9 | 3428 | /* Before reload, there are a few registers that must be forced |
21c7361e | 3429 | live everywhere -- which might not already be the case for |
39c39be9 | 3430 | blocks within infinite loops. */ |
770a7feb | 3431 | if (! reload_completed) |
39c39be9 | 3432 | { |
39c39be9 RH |
3433 | /* Any reference to any pseudo before reload is a potential |
3434 | reference of the frame pointer. */ | |
3435 | SET_REGNO_REG_SET (new_live_at_end, FRAME_POINTER_REGNUM); | |
3436 | ||
3437 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM | |
3438 | /* Pseudos with argument area equivalences may require | |
3439 | reloading via the argument pointer. */ | |
3440 | if (fixed_regs[ARG_POINTER_REGNUM]) | |
3441 | SET_REGNO_REG_SET (new_live_at_end, ARG_POINTER_REGNUM); | |
3442 | #endif | |
3443 | ||
39c39be9 RH |
3444 | /* Any constant, or pseudo with constant equivalences, may |
3445 | require reloading from memory using the pic register. */ | |
848e0190 JH |
3446 | if (PIC_OFFSET_TABLE_REGNUM != INVALID_REGNUM |
3447 | && fixed_regs[PIC_OFFSET_TABLE_REGNUM]) | |
39c39be9 | 3448 | SET_REGNO_REG_SET (new_live_at_end, PIC_OFFSET_TABLE_REGNUM); |
39c39be9 | 3449 | } |
770a7feb | 3450 | |
4e872036 AS |
3451 | /* Regs used in phi nodes are not included in |
3452 | global_live_at_start, since they are live only along a | |
3453 | particular edge. Set those regs that are live because of a | |
3454 | phi node alternative corresponding to this particular block. */ | |
1868a0d4 | 3455 | if (in_ssa_form) |
c9bacfdb | 3456 | for_each_successor_phi (bb, &set_phi_alternative_reg, |
1868a0d4 | 3457 | new_live_at_end); |
4e872036 | 3458 | |
d3a923ee RH |
3459 | if (bb == ENTRY_BLOCK_PTR) |
3460 | { | |
3461 | COPY_REG_SET (bb->global_live_at_end, new_live_at_end); | |
3462 | continue; | |
3463 | } | |
3464 | ||
c9bacfdb | 3465 | /* On our first pass through this block, we'll go ahead and continue. |
d3a923ee RH |
3466 | Recognize first pass by local_set NULL. On subsequent passes, we |
3467 | get to skip out early if live_at_end wouldn't have changed. */ | |
3468 | ||
3469 | if (bb->local_set == NULL) | |
3470 | { | |
1f8f4a0b | 3471 | bb->local_set = OBSTACK_ALLOC_REG_SET (&flow_obstack); |
7dfc0fbe | 3472 | bb->cond_local_set = OBSTACK_ALLOC_REG_SET (&flow_obstack); |
d3a923ee RH |
3473 | rescan = 1; |
3474 | } | |
3475 | else | |
3476 | { | |
3477 | /* If any bits were removed from live_at_end, we'll have to | |
3478 | rescan the block. This wouldn't be necessary if we had | |
3479 | precalculated local_live, however with PROP_SCAN_DEAD_CODE | |
4eb00163 | 3480 | local_live is really dependent on live_at_end. */ |
d3a923ee RH |
3481 | CLEAR_REG_SET (tmp); |
3482 | rescan = bitmap_operation (tmp, bb->global_live_at_end, | |
3483 | new_live_at_end, BITMAP_AND_COMPL); | |
3484 | ||
7dfc0fbe BS |
3485 | if (! rescan) |
3486 | { | |
3487 | /* If any of the registers in the new live_at_end set are | |
3488 | conditionally set in this basic block, we must rescan. | |
3489 | This is because conditional lifetimes at the end of the | |
3490 | block do not just take the live_at_end set into account, | |
3491 | but also the liveness at the start of each successor | |
3492 | block. We can miss changes in those sets if we only | |
3493 | compare the new live_at_end against the previous one. */ | |
3494 | CLEAR_REG_SET (tmp); | |
3495 | rescan = bitmap_operation (tmp, new_live_at_end, | |
3496 | bb->cond_local_set, BITMAP_AND); | |
3497 | } | |
3498 | ||
d3a923ee RH |
3499 | if (! rescan) |
3500 | { | |
3501 | /* Find the set of changed bits. Take this opportunity | |
3502 | to notice that this set is empty and early out. */ | |
3503 | CLEAR_REG_SET (tmp); | |
3504 | changed = bitmap_operation (tmp, bb->global_live_at_end, | |
3505 | new_live_at_end, BITMAP_XOR); | |
3506 | if (! changed) | |
3507 | continue; | |
3508 | ||
3509 | /* If any of the changed bits overlap with local_set, | |
3510 | we'll have to rescan the block. Detect overlap by | |
3511 | the AND with ~local_set turning off bits. */ | |
3512 | rescan = bitmap_operation (tmp, tmp, bb->local_set, | |
3513 | BITMAP_AND_COMPL); | |
3514 | } | |
3515 | } | |
3516 | ||
3517 | /* Let our caller know that BB changed enough to require its | |
3518 | death notes updated. */ | |
693d9e2f RH |
3519 | if (blocks_out) |
3520 | SET_BIT (blocks_out, bb->index); | |
d3a923ee RH |
3521 | |
3522 | if (! rescan) | |
3523 | { | |
3524 | /* Add to live_at_start the set of all registers in | |
3525 | new_live_at_end that aren't in the old live_at_end. */ | |
3526 | ||
3527 | bitmap_operation (tmp, new_live_at_end, bb->global_live_at_end, | |
3528 | BITMAP_AND_COMPL); | |
3529 | COPY_REG_SET (bb->global_live_at_end, new_live_at_end); | |
3530 | ||
3531 | changed = bitmap_operation (bb->global_live_at_start, | |
3532 | bb->global_live_at_start, | |
3533 | tmp, BITMAP_IOR); | |
3534 | if (! changed) | |
3535 | continue; | |
3536 | } | |
3537 | else | |
3538 | { | |
3539 | COPY_REG_SET (bb->global_live_at_end, new_live_at_end); | |
3540 | ||
3541 | /* Rescan the block insn by insn to turn (a copy of) live_at_end | |
3542 | into live_at_start. */ | |
7dfc0fbe BS |
3543 | propagate_block (bb, new_live_at_end, bb->local_set, |
3544 | bb->cond_local_set, flags); | |
d3a923ee RH |
3545 | |
3546 | /* If live_at start didn't change, no need to go farther. */ | |
3547 | if (REG_SET_EQUAL_P (bb->global_live_at_start, new_live_at_end)) | |
3548 | continue; | |
3549 | ||
3550 | COPY_REG_SET (bb->global_live_at_start, new_live_at_end); | |
3551 | } | |
3552 | ||
3553 | /* Queue all predecessors of BB so that we may re-examine | |
3554 | their live_at_end. */ | |
c9bacfdb | 3555 | for (e = bb->pred; e; e = e->pred_next) |
d3a923ee RH |
3556 | { |
3557 | basic_block pb = e->src; | |
3558 | if (pb->aux == NULL) | |
3559 | { | |
3560 | *qtail++ = pb; | |
3561 | if (qtail == qend) | |
3562 | qtail = queue; | |
3563 | pb->aux = pb; | |
3564 | } | |
3565 | } | |
3566 | } | |
3567 | ||
3568 | FREE_REG_SET (tmp); | |
3569 | FREE_REG_SET (new_live_at_end); | |
ad73b558 | 3570 | FREE_REG_SET (call_used); |
d3a923ee | 3571 | |
693d9e2f | 3572 | if (blocks_out) |
d3a923ee | 3573 | { |
693d9e2f RH |
3574 | EXECUTE_IF_SET_IN_SBITMAP (blocks_out, 0, i, |
3575 | { | |
3576 | basic_block bb = BASIC_BLOCK (i); | |
3577 | FREE_REG_SET (bb->local_set); | |
7dfc0fbe | 3578 | FREE_REG_SET (bb->cond_local_set); |
693d9e2f RH |
3579 | }); |
3580 | } | |
3581 | else | |
3582 | { | |
3583 | for (i = n_basic_blocks - 1; i >= 0; --i) | |
3584 | { | |
3585 | basic_block bb = BASIC_BLOCK (i); | |
3586 | FREE_REG_SET (bb->local_set); | |
7dfc0fbe | 3587 | FREE_REG_SET (bb->cond_local_set); |
693d9e2f RH |
3588 | } |
3589 | } | |
67289ea6 MM |
3590 | |
3591 | free (queue); | |
d7429b6a RK |
3592 | } |
3593 | \f | |
3594 | /* Subroutines of life analysis. */ | |
3595 | ||
3596 | /* Allocate the permanent data structures that represent the results | |
3597 | of life analysis. Not static since used also for stupid life analysis. */ | |
3598 | ||
1f8f4a0b | 3599 | static void |
359da67d | 3600 | allocate_bb_life_data () |
d7429b6a RK |
3601 | { |
3602 | register int i; | |
d7429b6a | 3603 | |
e881bb1b RH |
3604 | for (i = 0; i < n_basic_blocks; i++) |
3605 | { | |
3606 | basic_block bb = BASIC_BLOCK (i); | |
3607 | ||
1f8f4a0b MM |
3608 | bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); |
3609 | bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
e881bb1b RH |
3610 | } |
3611 | ||
3612 | ENTRY_BLOCK_PTR->global_live_at_end | |
1f8f4a0b | 3613 | = OBSTACK_ALLOC_REG_SET (&flow_obstack); |
e881bb1b | 3614 | EXIT_BLOCK_PTR->global_live_at_start |
1f8f4a0b | 3615 | = OBSTACK_ALLOC_REG_SET (&flow_obstack); |
d7429b6a | 3616 | |
1f8f4a0b | 3617 | regs_live_at_setjmp = OBSTACK_ALLOC_REG_SET (&flow_obstack); |
359da67d RH |
3618 | } |
3619 | ||
3620 | void | |
3621 | allocate_reg_life_data () | |
3622 | { | |
3623 | int i; | |
3624 | ||
a9f531a6 RH |
3625 | max_regno = max_reg_num (); |
3626 | ||
359da67d RH |
3627 | /* Recalculate the register space, in case it has grown. Old style |
3628 | vector oriented regsets would set regset_{size,bytes} here also. */ | |
3629 | allocate_reg_info (max_regno, FALSE, FALSE); | |
3630 | ||
c9bacfdb | 3631 | /* Reset all the data we'll collect in propagate_block and its |
49c3bb12 | 3632 | subroutines. */ |
359da67d | 3633 | for (i = 0; i < max_regno; i++) |
49c3bb12 RH |
3634 | { |
3635 | REG_N_SETS (i) = 0; | |
3636 | REG_N_REFS (i) = 0; | |
3637 | REG_N_DEATHS (i) = 0; | |
3638 | REG_N_CALLS_CROSSED (i) = 0; | |
3639 | REG_LIVE_LENGTH (i) = 0; | |
3640 | REG_BASIC_BLOCK (i) = REG_BLOCK_UNKNOWN; | |
3641 | } | |
d7429b6a RK |
3642 | } |
3643 | ||
62828c00 | 3644 | /* Delete dead instructions for propagate_block. */ |
d7429b6a | 3645 | |
62828c00 RH |
3646 | static void |
3647 | propagate_block_delete_insn (bb, insn) | |
3648 | basic_block bb; | |
3649 | rtx insn; | |
3650 | { | |
3651 | rtx inote = find_reg_note (insn, REG_LABEL, NULL_RTX); | |
d7429b6a | 3652 | |
62828c00 RH |
3653 | /* If the insn referred to a label, and that label was attached to |
3654 | an ADDR_VEC, it's safe to delete the ADDR_VEC. In fact, it's | |
3655 | pretty much mandatory to delete it, because the ADDR_VEC may be | |
3656 | referencing labels that no longer exist. */ | |
d7429b6a | 3657 | |
62828c00 RH |
3658 | if (inote) |
3659 | { | |
3660 | rtx label = XEXP (inote, 0); | |
3661 | rtx next; | |
3662 | ||
3663 | if (LABEL_NUSES (label) == 1 | |
3664 | && (next = next_nonnote_insn (label)) != NULL | |
3665 | && GET_CODE (next) == JUMP_INSN | |
3666 | && (GET_CODE (PATTERN (next)) == ADDR_VEC | |
3667 | || GET_CODE (PATTERN (next)) == ADDR_DIFF_VEC)) | |
3668 | { | |
3669 | rtx pat = PATTERN (next); | |
3670 | int diff_vec_p = GET_CODE (pat) == ADDR_DIFF_VEC; | |
3671 | int len = XVECLEN (pat, diff_vec_p); | |
3672 | int i; | |
d7429b6a | 3673 | |
62828c00 RH |
3674 | for (i = 0; i < len; i++) |
3675 | LABEL_NUSES (XEXP (XVECEXP (pat, diff_vec_p, i), 0))--; | |
d7429b6a | 3676 | |
62828c00 RH |
3677 | flow_delete_insn (next); |
3678 | } | |
3679 | } | |
3680 | ||
3681 | if (bb->end == insn) | |
3682 | bb->end = PREV_INSN (insn); | |
3683 | flow_delete_insn (insn); | |
3684 | } | |
3685 | ||
3686 | /* Delete dead libcalls for propagate_block. Return the insn | |
3687 | before the libcall. */ | |
3688 | ||
3689 | static rtx | |
3690 | propagate_block_delete_libcall (bb, insn, note) | |
65f6fa24 | 3691 | basic_block bb; |
62828c00 | 3692 | rtx insn, note; |
d7429b6a | 3693 | { |
62828c00 RH |
3694 | rtx first = XEXP (note, 0); |
3695 | rtx before = PREV_INSN (first); | |
d7429b6a | 3696 | |
62828c00 RH |
3697 | if (insn == bb->end) |
3698 | bb->end = before; | |
c9bacfdb | 3699 | |
62828c00 RH |
3700 | flow_delete_insn_chain (first, insn); |
3701 | return before; | |
3702 | } | |
d7429b6a | 3703 | |
292f3869 RH |
3704 | /* Update the life-status of regs for one insn. Return the previous insn. */ |
3705 | ||
3706 | rtx | |
3707 | propagate_one_insn (pbi, insn) | |
3708 | struct propagate_block_info *pbi; | |
3709 | rtx insn; | |
3710 | { | |
3711 | rtx prev = PREV_INSN (insn); | |
3712 | int flags = pbi->flags; | |
3713 | int insn_is_dead = 0; | |
3714 | int libcall_is_dead = 0; | |
3715 | rtx note; | |
3716 | int i; | |
3717 | ||
3718 | if (! INSN_P (insn)) | |
3719 | return prev; | |
3720 | ||
3721 | note = find_reg_note (insn, REG_RETVAL, NULL_RTX); | |
3722 | if (flags & PROP_SCAN_DEAD_CODE) | |
3723 | { | |
50e9b3f1 | 3724 | insn_is_dead = insn_dead_p (pbi, PATTERN (insn), 0, REG_NOTES (insn)); |
292f3869 | 3725 | libcall_is_dead = (insn_is_dead && note != 0 |
01fbc97d | 3726 | && libcall_dead_p (pbi, note, insn)); |
292f3869 RH |
3727 | } |
3728 | ||
292f3869 RH |
3729 | /* If an instruction consists of just dead store(s) on final pass, |
3730 | delete it. */ | |
3731 | if ((flags & PROP_KILL_DEAD_CODE) && insn_is_dead) | |
3732 | { | |
50e9b3f1 RK |
3733 | /* If we're trying to delete a prologue or epilogue instruction |
3734 | that isn't flagged as possibly being dead, something is wrong. | |
3735 | But if we are keeping the stack pointer depressed, we might well | |
3736 | be deleting insns that are used to compute the amount to update | |
3737 | it by, so they are fine. */ | |
3738 | if (reload_completed | |
3739 | && !(TREE_CODE (TREE_TYPE (current_function_decl)) == FUNCTION_TYPE | |
3740 | && (TYPE_RETURNS_STACK_DEPRESSED | |
3741 | (TREE_TYPE (current_function_decl)))) | |
3742 | && (((HAVE_epilogue || HAVE_prologue) | |
3743 | && prologue_epilogue_contains (insn)) | |
3744 | || (HAVE_sibcall_epilogue | |
3745 | && sibcall_epilogue_contains (insn))) | |
3746 | && find_reg_note (insn, REG_MAYBE_DEAD, NULL_RTX) == 0) | |
3747 | abort (); | |
3748 | ||
5e9e738c RH |
3749 | /* Record sets. Do this even for dead instructions, since they |
3750 | would have killed the values if they hadn't been deleted. */ | |
3751 | mark_set_regs (pbi, PATTERN (insn), insn); | |
3752 | ||
3753 | /* CC0 is now known to be dead. Either this insn used it, | |
3754 | in which case it doesn't anymore, or clobbered it, | |
3755 | so the next insn can't use it. */ | |
3756 | pbi->cc0_live = 0; | |
3757 | ||
292f3869 RH |
3758 | if (libcall_is_dead) |
3759 | { | |
3760 | prev = propagate_block_delete_libcall (pbi->bb, insn, note); | |
3761 | insn = NEXT_INSN (prev); | |
3762 | } | |
3763 | else | |
3764 | propagate_block_delete_insn (pbi->bb, insn); | |
3765 | ||
292f3869 RH |
3766 | return prev; |
3767 | } | |
3768 | ||
3769 | /* See if this is an increment or decrement that can be merged into | |
3770 | a following memory address. */ | |
3771 | #ifdef AUTO_INC_DEC | |
3772 | { | |
3773 | register rtx x = single_set (insn); | |
3774 | ||
3775 | /* Does this instruction increment or decrement a register? */ | |
61f286b6 | 3776 | if ((flags & PROP_AUTOINC) |
292f3869 RH |
3777 | && x != 0 |
3778 | && GET_CODE (SET_DEST (x)) == REG | |
3779 | && (GET_CODE (SET_SRC (x)) == PLUS | |
3780 | || GET_CODE (SET_SRC (x)) == MINUS) | |
3781 | && XEXP (SET_SRC (x), 0) == SET_DEST (x) | |
3782 | && GET_CODE (XEXP (SET_SRC (x), 1)) == CONST_INT | |
3783 | /* Ok, look for a following memory ref we can combine with. | |
3784 | If one is found, change the memory ref to a PRE_INC | |
3785 | or PRE_DEC, cancel this insn, and return 1. | |
3786 | Return 0 if nothing has been done. */ | |
3787 | && try_pre_increment_1 (pbi, insn)) | |
3788 | return prev; | |
3789 | } | |
3790 | #endif /* AUTO_INC_DEC */ | |
3791 | ||
9785c68d | 3792 | CLEAR_REG_SET (pbi->new_set); |
292f3869 RH |
3793 | |
3794 | /* If this is not the final pass, and this insn is copying the value of | |
3795 | a library call and it's dead, don't scan the insns that perform the | |
3796 | library call, so that the call's arguments are not marked live. */ | |
3797 | if (libcall_is_dead) | |
3798 | { | |
3799 | /* Record the death of the dest reg. */ | |
3800 | mark_set_regs (pbi, PATTERN (insn), insn); | |
3801 | ||
3802 | insn = XEXP (note, 0); | |
3803 | return PREV_INSN (insn); | |
3804 | } | |
3805 | else if (GET_CODE (PATTERN (insn)) == SET | |
3806 | && SET_DEST (PATTERN (insn)) == stack_pointer_rtx | |
3807 | && GET_CODE (SET_SRC (PATTERN (insn))) == PLUS | |
3808 | && XEXP (SET_SRC (PATTERN (insn)), 0) == stack_pointer_rtx | |
3809 | && GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == CONST_INT) | |
3810 | /* We have an insn to pop a constant amount off the stack. | |
3811 | (Such insns use PLUS regardless of the direction of the stack, | |
3812 | and any insn to adjust the stack by a constant is always a pop.) | |
3813 | These insns, if not dead stores, have no effect on life. */ | |
3814 | ; | |
3815 | else | |
3816 | { | |
3817 | /* Any regs live at the time of a call instruction must not go | |
3818 | in a register clobbered by calls. Find all regs now live and | |
3819 | record this for them. */ | |
3820 | ||
3821 | if (GET_CODE (insn) == CALL_INSN && (flags & PROP_REG_INFO)) | |
3822 | EXECUTE_IF_SET_IN_REG_SET (pbi->reg_live, 0, i, | |
3823 | { REG_N_CALLS_CROSSED (i)++; }); | |
3824 | ||
3825 | /* Record sets. Do this even for dead instructions, since they | |
3826 | would have killed the values if they hadn't been deleted. */ | |
3827 | mark_set_regs (pbi, PATTERN (insn), insn); | |
3828 | ||
3829 | if (GET_CODE (insn) == CALL_INSN) | |
3830 | { | |
3831 | register int i; | |
3832 | rtx note, cond; | |
3833 | ||
3834 | cond = NULL_RTX; | |
3835 | if (GET_CODE (PATTERN (insn)) == COND_EXEC) | |
3836 | cond = COND_EXEC_TEST (PATTERN (insn)); | |
3837 | ||
3838 | /* Non-constant calls clobber memory. */ | |
3839 | if (! CONST_CALL_P (insn)) | |
0875baa0 RH |
3840 | { |
3841 | free_EXPR_LIST_list (&pbi->mem_set_list); | |
3842 | pbi->mem_set_list_len = 0; | |
3843 | } | |
292f3869 RH |
3844 | |
3845 | /* There may be extra registers to be clobbered. */ | |
3846 | for (note = CALL_INSN_FUNCTION_USAGE (insn); | |
3847 | note; | |
3848 | note = XEXP (note, 1)) | |
3849 | if (GET_CODE (XEXP (note, 0)) == CLOBBER) | |
b4593d17 RH |
3850 | mark_set_1 (pbi, CLOBBER, XEXP (XEXP (note, 0), 0), |
3851 | cond, insn, pbi->flags); | |
292f3869 RH |
3852 | |
3853 | /* Calls change all call-used and global registers. */ | |
3854 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
3855 | if (call_used_regs[i] && ! global_regs[i] | |
3856 | && ! fixed_regs[i]) | |
3857 | { | |
b4593d17 RH |
3858 | /* We do not want REG_UNUSED notes for these registers. */ |
3859 | mark_set_1 (pbi, CLOBBER, gen_rtx_REG (reg_raw_mode[i], i), | |
8d6fe133 RH |
3860 | cond, insn, |
3861 | pbi->flags & ~(PROP_DEATH_NOTES | PROP_REG_INFO)); | |
292f3869 RH |
3862 | } |
3863 | } | |
3864 | ||
3865 | /* If an insn doesn't use CC0, it becomes dead since we assume | |
3866 | that every insn clobbers it. So show it dead here; | |
3867 | mark_used_regs will set it live if it is referenced. */ | |
3868 | pbi->cc0_live = 0; | |
3869 | ||
3870 | /* Record uses. */ | |
3871 | if (! insn_is_dead) | |
3872 | mark_used_regs (pbi, PATTERN (insn), NULL_RTX, insn); | |
3873 | ||
3874 | /* Sometimes we may have inserted something before INSN (such as a move) | |
3875 | when we make an auto-inc. So ensure we will scan those insns. */ | |
3876 | #ifdef AUTO_INC_DEC | |
3877 | prev = PREV_INSN (insn); | |
3878 | #endif | |
3879 | ||
3880 | if (! insn_is_dead && GET_CODE (insn) == CALL_INSN) | |
3881 | { | |
3882 | register int i; | |
3883 | rtx note, cond; | |
3884 | ||
3885 | cond = NULL_RTX; | |
3886 | if (GET_CODE (PATTERN (insn)) == COND_EXEC) | |
3887 | cond = COND_EXEC_TEST (PATTERN (insn)); | |
3888 | ||
3889 | /* Calls use their arguments. */ | |
3890 | for (note = CALL_INSN_FUNCTION_USAGE (insn); | |
3891 | note; | |
3892 | note = XEXP (note, 1)) | |
3893 | if (GET_CODE (XEXP (note, 0)) == USE) | |
3894 | mark_used_regs (pbi, XEXP (XEXP (note, 0), 0), | |
3895 | cond, insn); | |
3896 | ||
3897 | /* The stack ptr is used (honorarily) by a CALL insn. */ | |
3898 | SET_REGNO_REG_SET (pbi->reg_live, STACK_POINTER_REGNUM); | |
3899 | ||
3900 | /* Calls may also reference any of the global registers, | |
3901 | so they are made live. */ | |
3902 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
3903 | if (global_regs[i]) | |
3904 | mark_used_reg (pbi, gen_rtx_REG (reg_raw_mode[i], i), | |
3905 | cond, insn); | |
3906 | } | |
3907 | } | |
3908 | ||
292f3869 RH |
3909 | /* On final pass, update counts of how many insns in which each reg |
3910 | is live. */ | |
3911 | if (flags & PROP_REG_INFO) | |
3912 | EXECUTE_IF_SET_IN_REG_SET (pbi->reg_live, 0, i, | |
3913 | { REG_LIVE_LENGTH (i)++; }); | |
3914 | ||
3915 | return prev; | |
3916 | } | |
3917 | ||
3918 | /* Initialize a propagate_block_info struct for public consumption. | |
3919 | Note that the structure itself is opaque to this file, but that | |
3920 | the user can use the regsets provided here. */ | |
3921 | ||
3922 | struct propagate_block_info * | |
7dfc0fbe | 3923 | init_propagate_block_info (bb, live, local_set, cond_local_set, flags) |
292f3869 | 3924 | basic_block bb; |
7dfc0fbe | 3925 | regset live, local_set, cond_local_set; |
292f3869 RH |
3926 | int flags; |
3927 | { | |
c9bacfdb | 3928 | struct propagate_block_info *pbi = xmalloc (sizeof (*pbi)); |
292f3869 RH |
3929 | |
3930 | pbi->bb = bb; | |
3931 | pbi->reg_live = live; | |
3932 | pbi->mem_set_list = NULL_RTX; | |
0875baa0 | 3933 | pbi->mem_set_list_len = 0; |
292f3869 | 3934 | pbi->local_set = local_set; |
7dfc0fbe | 3935 | pbi->cond_local_set = cond_local_set; |
292f3869 RH |
3936 | pbi->cc0_live = 0; |
3937 | pbi->flags = flags; | |
3938 | ||
3939 | if (flags & (PROP_LOG_LINKS | PROP_AUTOINC)) | |
3940 | pbi->reg_next_use = (rtx *) xcalloc (max_reg_num (), sizeof (rtx)); | |
3941 | else | |
3942 | pbi->reg_next_use = NULL; | |
3943 | ||
9785c68d | 3944 | pbi->new_set = BITMAP_XMALLOC (); |
292f3869 | 3945 | |
11ae508b RH |
3946 | #ifdef HAVE_conditional_execution |
3947 | pbi->reg_cond_dead = splay_tree_new (splay_tree_compare_ints, NULL, | |
3948 | free_reg_cond_life_info); | |
3949 | pbi->reg_cond_reg = BITMAP_XMALLOC (); | |
3950 | ||
3951 | /* If this block ends in a conditional branch, for each register live | |
3952 | from one side of the branch and not the other, record the register | |
3953 | as conditionally dead. */ | |
288c2c9e | 3954 | if (GET_CODE (bb->end) == JUMP_INSN |
7f1c097d | 3955 | && any_condjump_p (bb->end)) |
11ae508b RH |
3956 | { |
3957 | regset_head diff_head; | |
3958 | regset diff = INITIALIZE_REG_SET (diff_head); | |
3959 | basic_block bb_true, bb_false; | |
3a8c5c77 | 3960 | rtx cond_true, cond_false, set_src; |
11ae508b RH |
3961 | int i; |
3962 | ||
3963 | /* Identify the successor blocks. */ | |
11ae508b | 3964 | bb_true = bb->succ->dest; |
4fb9b830 | 3965 | if (bb->succ->succ_next != NULL) |
11ae508b | 3966 | { |
c9bacfdb | 3967 | bb_false = bb->succ->succ_next->dest; |
4fb9b830 RH |
3968 | |
3969 | if (bb->succ->flags & EDGE_FALLTHRU) | |
3970 | { | |
3971 | basic_block t = bb_false; | |
3972 | bb_false = bb_true; | |
3973 | bb_true = t; | |
3974 | } | |
3975 | else if (! (bb->succ->succ_next->flags & EDGE_FALLTHRU)) | |
3976 | abort (); | |
3977 | } | |
3978 | else | |
3979 | { | |
3980 | /* This can happen with a conditional jump to the next insn. */ | |
3981 | if (JUMP_LABEL (bb->end) != bb_true->head) | |
3982 | abort (); | |
3983 | ||
3984 | /* Simplest way to do nothing. */ | |
11ae508b | 3985 | bb_false = bb_true; |
11ae508b | 3986 | } |
c9bacfdb | 3987 | |
11ae508b | 3988 | /* Extract the condition from the branch. */ |
3a8c5c77 RH |
3989 | set_src = SET_SRC (pc_set (bb->end)); |
3990 | cond_true = XEXP (set_src, 0); | |
11ae508b RH |
3991 | cond_false = gen_rtx_fmt_ee (reverse_condition (GET_CODE (cond_true)), |
3992 | GET_MODE (cond_true), XEXP (cond_true, 0), | |
3993 | XEXP (cond_true, 1)); | |
3a8c5c77 | 3994 | if (GET_CODE (XEXP (set_src, 1)) == PC) |
11ae508b RH |
3995 | { |
3996 | rtx t = cond_false; | |
3997 | cond_false = cond_true; | |
3998 | cond_true = t; | |
3999 | } | |
4000 | ||
4001 | /* Compute which register lead different lives in the successors. */ | |
4002 | if (bitmap_operation (diff, bb_true->global_live_at_start, | |
4003 | bb_false->global_live_at_start, BITMAP_XOR)) | |
4004 | { | |
056b6841 RE |
4005 | rtx reg = XEXP (cond_true, 0); |
4006 | ||
4007 | if (GET_CODE (reg) == SUBREG) | |
4008 | reg = SUBREG_REG (reg); | |
4009 | ||
4010 | if (GET_CODE (reg) != REG) | |
11ae508b | 4011 | abort (); |
056b6841 RE |
4012 | |
4013 | SET_REGNO_REG_SET (pbi->reg_cond_reg, REGNO (reg)); | |
11ae508b RH |
4014 | |
4015 | /* For each such register, mark it conditionally dead. */ | |
4016 | EXECUTE_IF_SET_IN_REG_SET | |
4017 | (diff, 0, i, | |
4018 | { | |
4019 | struct reg_cond_life_info *rcli; | |
4020 | rtx cond; | |
4021 | ||
4022 | rcli = (struct reg_cond_life_info *) xmalloc (sizeof (*rcli)); | |
4023 | ||
4024 | if (REGNO_REG_SET_P (bb_true->global_live_at_start, i)) | |
4025 | cond = cond_false; | |
4026 | else | |
4027 | cond = cond_true; | |
288c2c9e | 4028 | rcli->condition = cond; |
685af3af JW |
4029 | rcli->stores = const0_rtx; |
4030 | rcli->orig_condition = cond; | |
11ae508b | 4031 | |
ad3958e7 | 4032 | splay_tree_insert (pbi->reg_cond_dead, i, |
11ae508b RH |
4033 | (splay_tree_value) rcli); |
4034 | }); | |
4035 | } | |
4036 | ||
4037 | FREE_REG_SET (diff); | |
4038 | } | |
4039 | #endif | |
4040 | ||
eb7e5da2 RH |
4041 | /* If this block has no successors, any stores to the frame that aren't |
4042 | used later in the block are dead. So make a pass over the block | |
4043 | recording any such that are made and show them dead at the end. We do | |
4044 | a very conservative and simple job here. */ | |
b2262f4a | 4045 | if (optimize |
6324d2bb RK |
4046 | && ! (TREE_CODE (TREE_TYPE (current_function_decl)) == FUNCTION_TYPE |
4047 | && (TYPE_RETURNS_STACK_DEPRESSED | |
4048 | (TREE_TYPE (current_function_decl)))) | |
b2262f4a | 4049 | && (flags & PROP_SCAN_DEAD_CODE) |
eb7e5da2 | 4050 | && (bb->succ == NULL |
c9bacfdb | 4051 | || (bb->succ->succ_next == NULL |
52a11cbf RH |
4052 | && bb->succ->dest == EXIT_BLOCK_PTR |
4053 | && ! current_function_calls_eh_return))) | |
eb7e5da2 | 4054 | { |
ccfce8d2 | 4055 | rtx insn, set; |
eb7e5da2 RH |
4056 | for (insn = bb->end; insn != bb->head; insn = PREV_INSN (insn)) |
4057 | if (GET_CODE (insn) == INSN | |
ccfce8d2 JH |
4058 | && (set = single_set (insn)) |
4059 | && GET_CODE (SET_DEST (set)) == MEM) | |
eb7e5da2 | 4060 | { |
ccfce8d2 JH |
4061 | rtx mem = SET_DEST (set); |
4062 | rtx canon_mem = canon_rtx (mem); | |
c9bacfdb | 4063 | |
240f9c2b RH |
4064 | /* This optimization is performed by faking a store to the |
4065 | memory at the end of the block. This doesn't work for | |
4066 | unchanging memories because multiple stores to unchanging | |
4067 | memory is illegal and alias analysis doesn't consider it. */ | |
ccfce8d2 | 4068 | if (RTX_UNCHANGING_P (canon_mem)) |
240f9c2b RH |
4069 | continue; |
4070 | ||
ccfce8d2 JH |
4071 | if (XEXP (canon_mem, 0) == frame_pointer_rtx |
4072 | || (GET_CODE (XEXP (canon_mem, 0)) == PLUS | |
4073 | && XEXP (XEXP (canon_mem, 0), 0) == frame_pointer_rtx | |
4074 | && GET_CODE (XEXP (XEXP (canon_mem, 0), 1)) == CONST_INT)) | |
c32e1e6f RH |
4075 | { |
4076 | #ifdef AUTO_INC_DEC | |
4077 | /* Store a copy of mem, otherwise the address may be scrogged | |
4078 | by find_auto_inc. This matters because insn_dead_p uses | |
4079 | an rtx_equal_p check to determine if two addresses are | |
4080 | the same. This works before find_auto_inc, but fails | |
4081 | after find_auto_inc, causing discrepencies between the | |
4082 | set of live registers calculated during the | |
4083 | calculate_global_regs_live phase and what actually exists | |
4084 | after flow completes, leading to aborts. */ | |
4085 | if (flags & PROP_AUTOINC) | |
4086 | mem = shallow_copy_rtx (mem); | |
4087 | #endif | |
4088 | pbi->mem_set_list = alloc_EXPR_LIST (0, mem, pbi->mem_set_list); | |
0875baa0 RH |
4089 | if (++pbi->mem_set_list_len >= MAX_MEM_SET_LIST_LEN) |
4090 | break; | |
c32e1e6f | 4091 | } |
eb7e5da2 RH |
4092 | } |
4093 | } | |
4094 | ||
292f3869 RH |
4095 | return pbi; |
4096 | } | |
4097 | ||
4098 | /* Release a propagate_block_info struct. */ | |
4099 | ||
4100 | void | |
4101 | free_propagate_block_info (pbi) | |
4102 | struct propagate_block_info *pbi; | |
4103 | { | |
4104 | free_EXPR_LIST_list (&pbi->mem_set_list); | |
4105 | ||
9785c68d | 4106 | BITMAP_XFREE (pbi->new_set); |
292f3869 | 4107 | |
11ae508b RH |
4108 | #ifdef HAVE_conditional_execution |
4109 | splay_tree_delete (pbi->reg_cond_dead); | |
4110 | BITMAP_XFREE (pbi->reg_cond_reg); | |
4111 | #endif | |
4112 | ||
292f3869 RH |
4113 | if (pbi->reg_next_use) |
4114 | free (pbi->reg_next_use); | |
4115 | ||
4116 | free (pbi); | |
4117 | } | |
4118 | ||
62828c00 RH |
4119 | /* Compute the registers live at the beginning of a basic block BB from |
4120 | those live at the end. | |
d7429b6a | 4121 | |
62828c00 RH |
4122 | When called, REG_LIVE contains those live at the end. On return, it |
4123 | contains those live at the beginning. | |
4124 | ||
7dfc0fbe BS |
4125 | LOCAL_SET, if non-null, will be set with all registers killed |
4126 | unconditionally by this basic block. | |
4127 | Likewise, COND_LOCAL_SET, if non-null, will be set with all registers | |
4128 | killed conditionally by this basic block. If there is any unconditional | |
4129 | set of a register, then the corresponding bit will be set in LOCAL_SET | |
4130 | and cleared in COND_LOCAL_SET. | |
4131 | It is valid for LOCAL_SET and COND_LOCAL_SET to be the same set. In this | |
4132 | case, the resulting set will be equal to the union of the two sets that | |
4133 | would otherwise be computed. */ | |
62828c00 | 4134 | |
292f3869 | 4135 | void |
7dfc0fbe | 4136 | propagate_block (bb, live, local_set, cond_local_set, flags) |
62828c00 RH |
4137 | basic_block bb; |
4138 | regset live; | |
4139 | regset local_set; | |
7dfc0fbe | 4140 | regset cond_local_set; |
62828c00 RH |
4141 | int flags; |
4142 | { | |
292f3869 | 4143 | struct propagate_block_info *pbi; |
62828c00 | 4144 | rtx insn, prev; |
c9bacfdb | 4145 | |
7dfc0fbe | 4146 | pbi = init_propagate_block_info (bb, live, local_set, cond_local_set, flags); |
d7429b6a | 4147 | |
d3a923ee | 4148 | if (flags & PROP_REG_INFO) |
d7429b6a | 4149 | { |
916b1701 | 4150 | register int i; |
d7429b6a | 4151 | |
d7429b6a | 4152 | /* Process the regs live at the end of the block. |
c9bacfdb | 4153 | Mark them as not local to any one basic block. */ |
62828c00 | 4154 | EXECUTE_IF_SET_IN_REG_SET (live, 0, i, |
292f3869 | 4155 | { REG_BASIC_BLOCK (i) = REG_BLOCK_GLOBAL; }); |
d7429b6a RK |
4156 | } |
4157 | ||
4158 | /* Scan the block an insn at a time from end to beginning. */ | |
4159 | ||
c9bacfdb | 4160 | for (insn = bb->end;; insn = prev) |
d7429b6a | 4161 | { |
292f3869 RH |
4162 | /* If this is a call to `setjmp' et al, warn if any |
4163 | non-volatile datum is live. */ | |
4164 | if ((flags & PROP_REG_INFO) | |
4165 | && GET_CODE (insn) == NOTE | |
4166 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_SETJMP) | |
4167 | IOR_REG_SET (regs_live_at_setjmp, pbi->reg_live); | |
11f246f6 | 4168 | |
292f3869 | 4169 | prev = propagate_one_insn (pbi, insn); |
d7429b6a | 4170 | |
65f6fa24 | 4171 | if (insn == bb->head) |
d7429b6a RK |
4172 | break; |
4173 | } | |
4174 | ||
292f3869 | 4175 | free_propagate_block_info (pbi); |
d7429b6a RK |
4176 | } |
4177 | \f | |
4178 | /* Return 1 if X (the body of an insn, or part of it) is just dead stores | |
4179 | (SET expressions whose destinations are registers dead after the insn). | |
4180 | NEEDED is the regset that says which regs are alive after the insn. | |
4181 | ||
e398aa80 R |
4182 | Unless CALL_OK is non-zero, an insn is needed if it contains a CALL. |
4183 | ||
4184 | If X is the entire body of an insn, NOTES contains the reg notes | |
4185 | pertaining to the insn. */ | |
d7429b6a RK |
4186 | |
4187 | static int | |
62828c00 RH |
4188 | insn_dead_p (pbi, x, call_ok, notes) |
4189 | struct propagate_block_info *pbi; | |
d7429b6a | 4190 | rtx x; |
d7429b6a | 4191 | int call_ok; |
e398aa80 | 4192 | rtx notes ATTRIBUTE_UNUSED; |
d7429b6a | 4193 | { |
e5e809f4 JL |
4194 | enum rtx_code code = GET_CODE (x); |
4195 | ||
e398aa80 R |
4196 | #ifdef AUTO_INC_DEC |
4197 | /* If flow is invoked after reload, we must take existing AUTO_INC | |
4198 | expresions into account. */ | |
4199 | if (reload_completed) | |
4200 | { | |
c9bacfdb | 4201 | for (; notes; notes = XEXP (notes, 1)) |
e398aa80 R |
4202 | { |
4203 | if (REG_NOTE_KIND (notes) == REG_INC) | |
4204 | { | |
4205 | int regno = REGNO (XEXP (notes, 0)); | |
4206 | ||
4207 | /* Don't delete insns to set global regs. */ | |
4208 | if ((regno < FIRST_PSEUDO_REGISTER && global_regs[regno]) | |
62828c00 | 4209 | || REGNO_REG_SET_P (pbi->reg_live, regno)) |
e398aa80 R |
4210 | return 0; |
4211 | } | |
4212 | } | |
4213 | } | |
4214 | #endif | |
4215 | ||
d7429b6a RK |
4216 | /* If setting something that's a reg or part of one, |
4217 | see if that register's altered value will be live. */ | |
4218 | ||
4219 | if (code == SET) | |
4220 | { | |
e5e809f4 JL |
4221 | rtx r = SET_DEST (x); |
4222 | ||
d7429b6a RK |
4223 | #ifdef HAVE_cc0 |
4224 | if (GET_CODE (r) == CC0) | |
62828c00 | 4225 | return ! pbi->cc0_live; |
d7429b6a | 4226 | #endif |
c9bacfdb | 4227 | |
3ea8083f JL |
4228 | /* A SET that is a subroutine call cannot be dead. */ |
4229 | if (GET_CODE (SET_SRC (x)) == CALL) | |
4230 | { | |
4231 | if (! call_ok) | |
4232 | return 0; | |
4233 | } | |
4234 | ||
4235 | /* Don't eliminate loads from volatile memory or volatile asms. */ | |
4236 | else if (volatile_refs_p (SET_SRC (x))) | |
4237 | return 0; | |
4238 | ||
4239 | if (GET_CODE (r) == MEM) | |
db3a887b CB |
4240 | { |
4241 | rtx temp; | |
3ea8083f JL |
4242 | |
4243 | if (MEM_VOLATILE_P (r)) | |
4244 | return 0; | |
4245 | ||
db3a887b CB |
4246 | /* Walk the set of memory locations we are currently tracking |
4247 | and see if one is an identical match to this memory location. | |
4248 | If so, this memory write is dead (remember, we're walking | |
e8ea2809 RK |
4249 | backwards from the end of the block to the start). Since |
4250 | rtx_equal_p does not check the alias set or flags, we also | |
4251 | must have the potential for them to conflict (anti_dependence). */ | |
4252 | for (temp = pbi->mem_set_list; temp != 0; temp = XEXP (temp, 1)) | |
4253 | if (anti_dependence (r, XEXP (temp, 0))) | |
4254 | { | |
4255 | rtx mem = XEXP (temp, 0); | |
4f4b88d0 | 4256 | |
e8ea2809 RK |
4257 | if (rtx_equal_p (mem, r)) |
4258 | return 1; | |
4f4b88d0 | 4259 | #ifdef AUTO_INC_DEC |
e8ea2809 RK |
4260 | /* Check if memory reference matches an auto increment. Only |
4261 | post increment/decrement or modify are valid. */ | |
4262 | if (GET_MODE (mem) == GET_MODE (r) | |
4263 | && (GET_CODE (XEXP (mem, 0)) == POST_DEC | |
4264 | || GET_CODE (XEXP (mem, 0)) == POST_INC | |
4265 | || GET_CODE (XEXP (mem, 0)) == POST_MODIFY) | |
4266 | && GET_MODE (XEXP (mem, 0)) == GET_MODE (r) | |
4267 | && rtx_equal_p (XEXP (XEXP (mem, 0), 0), XEXP (r, 0))) | |
4268 | return 1; | |
4f4b88d0 | 4269 | #endif |
e8ea2809 | 4270 | } |
db3a887b | 4271 | } |
3ea8083f JL |
4272 | else |
4273 | { | |
4274 | while (GET_CODE (r) == SUBREG | |
4275 | || GET_CODE (r) == STRICT_LOW_PART | |
4276 | || GET_CODE (r) == ZERO_EXTRACT) | |
4277 | r = XEXP (r, 0); | |
d7429b6a | 4278 | |
3ea8083f JL |
4279 | if (GET_CODE (r) == REG) |
4280 | { | |
4281 | int regno = REGNO (r); | |
d7429b6a | 4282 | |
3ea8083f | 4283 | /* Obvious. */ |
62828c00 | 4284 | if (REGNO_REG_SET_P (pbi->reg_live, regno)) |
3ea8083f JL |
4285 | return 0; |
4286 | ||
4287 | /* If this is a hard register, verify that subsequent | |
4288 | words are not needed. */ | |
4289 | if (regno < FIRST_PSEUDO_REGISTER) | |
4290 | { | |
4291 | int n = HARD_REGNO_NREGS (regno, GET_MODE (r)); | |
4292 | ||
4293 | while (--n > 0) | |
62828c00 | 4294 | if (REGNO_REG_SET_P (pbi->reg_live, regno+n)) |
3ea8083f JL |
4295 | return 0; |
4296 | } | |
4297 | ||
4298 | /* Don't delete insns to set global regs. */ | |
4299 | if (regno < FIRST_PSEUDO_REGISTER && global_regs[regno]) | |
4300 | return 0; | |
4301 | ||
4302 | /* Make sure insns to set the stack pointer aren't deleted. */ | |
4303 | if (regno == STACK_POINTER_REGNUM) | |
4304 | return 0; | |
d7429b6a | 4305 | |
39c39be9 RH |
4306 | /* ??? These bits might be redundant with the force live bits |
4307 | in calculate_global_regs_live. We would delete from | |
4308 | sequential sets; whether this actually affects real code | |
4309 | for anything but the stack pointer I don't know. */ | |
3ea8083f JL |
4310 | /* Make sure insns to set the frame pointer aren't deleted. */ |
4311 | if (regno == FRAME_POINTER_REGNUM | |
e4b8a413 | 4312 | && (! reload_completed || frame_pointer_needed)) |
3ea8083f | 4313 | return 0; |
73a187c1 | 4314 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
3ea8083f | 4315 | if (regno == HARD_FRAME_POINTER_REGNUM |
e4b8a413 | 4316 | && (! reload_completed || frame_pointer_needed)) |
3ea8083f | 4317 | return 0; |
73a187c1 | 4318 | #endif |
3ea8083f | 4319 | |
d7e4fe8b RS |
4320 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
4321 | /* Make sure insns to set arg pointer are never deleted | |
3ea8083f JL |
4322 | (if the arg pointer isn't fixed, there will be a USE |
4323 | for it, so we can treat it normally). */ | |
4324 | if (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) | |
4325 | return 0; | |
d7e4fe8b | 4326 | #endif |
d7429b6a | 4327 | |
3ea8083f JL |
4328 | /* Otherwise, the set is dead. */ |
4329 | return 1; | |
d7429b6a | 4330 | } |
d7429b6a RK |
4331 | } |
4332 | } | |
e5e809f4 | 4333 | |
3ea8083f JL |
4334 | /* If performing several activities, insn is dead if each activity |
4335 | is individually dead. Also, CLOBBERs and USEs can be ignored; a | |
4336 | CLOBBER or USE that's inside a PARALLEL doesn't make the insn | |
4337 | worth keeping. */ | |
d7429b6a RK |
4338 | else if (code == PARALLEL) |
4339 | { | |
e5e809f4 JL |
4340 | int i = XVECLEN (x, 0); |
4341 | ||
d7429b6a | 4342 | for (i--; i >= 0; i--) |
e5e809f4 JL |
4343 | if (GET_CODE (XVECEXP (x, 0, i)) != CLOBBER |
4344 | && GET_CODE (XVECEXP (x, 0, i)) != USE | |
62828c00 | 4345 | && ! insn_dead_p (pbi, XVECEXP (x, 0, i), call_ok, NULL_RTX)) |
e5e809f4 JL |
4346 | return 0; |
4347 | ||
d7429b6a RK |
4348 | return 1; |
4349 | } | |
e5e809f4 JL |
4350 | |
4351 | /* A CLOBBER of a pseudo-register that is dead serves no purpose. That | |
4352 | is not necessarily true for hard registers. */ | |
4353 | else if (code == CLOBBER && GET_CODE (XEXP (x, 0)) == REG | |
4354 | && REGNO (XEXP (x, 0)) >= FIRST_PSEUDO_REGISTER | |
62828c00 | 4355 | && ! REGNO_REG_SET_P (pbi->reg_live, REGNO (XEXP (x, 0)))) |
e5e809f4 JL |
4356 | return 1; |
4357 | ||
4358 | /* We do not check other CLOBBER or USE here. An insn consisting of just | |
4359 | a CLOBBER or just a USE should not be deleted. */ | |
d7429b6a RK |
4360 | return 0; |
4361 | } | |
4362 | ||
01fbc97d | 4363 | /* If INSN is the last insn in a libcall, and assuming INSN is dead, |
d7429b6a | 4364 | return 1 if the entire library call is dead. |
01fbc97d SC |
4365 | This is true if INSN copies a register (hard or pseudo) |
4366 | and if the hard return reg of the call insn is dead. | |
4367 | (The caller should have tested the destination of the SET inside | |
4368 | INSN already for death.) | |
d7429b6a RK |
4369 | |
4370 | If this insn doesn't just copy a register, then we don't | |
4371 | have an ordinary libcall. In that case, cse could not have | |
4372 | managed to substitute the source for the dest later on, | |
4373 | so we can assume the libcall is dead. | |
4374 | ||
01fbc97d SC |
4375 | PBI is the block info giving pseudoregs live before this insn. |
4376 | NOTE is the REG_RETVAL note of the insn. */ | |
d7429b6a RK |
4377 | |
4378 | static int | |
01fbc97d | 4379 | libcall_dead_p (pbi, note, insn) |
62828c00 | 4380 | struct propagate_block_info *pbi; |
d7429b6a RK |
4381 | rtx note; |
4382 | rtx insn; | |
4383 | { | |
01fbc97d | 4384 | rtx x = single_set (insn); |
d7429b6a | 4385 | |
01fbc97d | 4386 | if (x) |
d7429b6a RK |
4387 | { |
4388 | register rtx r = SET_SRC (x); | |
4389 | if (GET_CODE (r) == REG) | |
4390 | { | |
4391 | rtx call = XEXP (note, 0); | |
e398aa80 | 4392 | rtx call_pat; |
d7429b6a RK |
4393 | register int i; |
4394 | ||
4395 | /* Find the call insn. */ | |
4396 | while (call != insn && GET_CODE (call) != CALL_INSN) | |
4397 | call = NEXT_INSN (call); | |
4398 | ||
4399 | /* If there is none, do nothing special, | |
4400 | since ordinary death handling can understand these insns. */ | |
4401 | if (call == insn) | |
4402 | return 0; | |
4403 | ||
4404 | /* See if the hard reg holding the value is dead. | |
4405 | If this is a PARALLEL, find the call within it. */ | |
e398aa80 R |
4406 | call_pat = PATTERN (call); |
4407 | if (GET_CODE (call_pat) == PARALLEL) | |
d7429b6a | 4408 | { |
e398aa80 R |
4409 | for (i = XVECLEN (call_pat, 0) - 1; i >= 0; i--) |
4410 | if (GET_CODE (XVECEXP (call_pat, 0, i)) == SET | |
4411 | && GET_CODE (SET_SRC (XVECEXP (call_pat, 0, i))) == CALL) | |
d7429b6a RK |
4412 | break; |
4413 | ||
761a5bcd JW |
4414 | /* This may be a library call that is returning a value |
4415 | via invisible pointer. Do nothing special, since | |
4416 | ordinary death handling can understand these insns. */ | |
d7429b6a | 4417 | if (i < 0) |
761a5bcd | 4418 | return 0; |
d7429b6a | 4419 | |
e398aa80 | 4420 | call_pat = XVECEXP (call_pat, 0, i); |
d7429b6a RK |
4421 | } |
4422 | ||
62828c00 | 4423 | return insn_dead_p (pbi, call_pat, 1, REG_NOTES (call)); |
d7429b6a RK |
4424 | } |
4425 | } | |
4426 | return 1; | |
4427 | } | |
4428 | ||
bd80fbde RH |
4429 | /* Return 1 if register REGNO was used before it was set, i.e. if it is |
4430 | live at function entry. Don't count global register variables, variables | |
4431 | in registers that can be used for function arg passing, or variables in | |
4432 | fixed hard registers. */ | |
d7429b6a RK |
4433 | |
4434 | int | |
4435 | regno_uninitialized (regno) | |
4436 | int regno; | |
4437 | { | |
b0b7b46a | 4438 | if (n_basic_blocks == 0 |
6a45254e | 4439 | || (regno < FIRST_PSEUDO_REGISTER |
bd80fbde RH |
4440 | && (global_regs[regno] |
4441 | || fixed_regs[regno] | |
4442 | || FUNCTION_ARG_REGNO_P (regno)))) | |
d7429b6a RK |
4443 | return 0; |
4444 | ||
e881bb1b | 4445 | return REGNO_REG_SET_P (BASIC_BLOCK (0)->global_live_at_start, regno); |
d7429b6a RK |
4446 | } |
4447 | ||
4448 | /* 1 if register REGNO was alive at a place where `setjmp' was called | |
4449 | and was set more than once or is an argument. | |
4450 | Such regs may be clobbered by `longjmp'. */ | |
4451 | ||
4452 | int | |
4453 | regno_clobbered_at_setjmp (regno) | |
4454 | int regno; | |
4455 | { | |
4456 | if (n_basic_blocks == 0) | |
4457 | return 0; | |
4458 | ||
b1f21e0a | 4459 | return ((REG_N_SETS (regno) > 1 |
e881bb1b | 4460 | || REGNO_REG_SET_P (BASIC_BLOCK (0)->global_live_at_start, regno)) |
916b1701 | 4461 | && REGNO_REG_SET_P (regs_live_at_setjmp, regno)); |
d7429b6a RK |
4462 | } |
4463 | \f | |
15e088b2 JL |
4464 | /* INSN references memory, possibly using autoincrement addressing modes. |
4465 | Find any entries on the mem_set_list that need to be invalidated due | |
4466 | to an address change. */ | |
a4c44acf | 4467 | |
15e088b2 | 4468 | static void |
62828c00 RH |
4469 | invalidate_mems_from_autoinc (pbi, insn) |
4470 | struct propagate_block_info *pbi; | |
15e088b2 JL |
4471 | rtx insn; |
4472 | { | |
4473 | rtx note = REG_NOTES (insn); | |
4474 | for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) | |
4475 | { | |
4476 | if (REG_NOTE_KIND (note) == REG_INC) | |
c9bacfdb KH |
4477 | { |
4478 | rtx temp = pbi->mem_set_list; | |
4479 | rtx prev = NULL_RTX; | |
ff666313 | 4480 | rtx next; |
15e088b2 | 4481 | |
c9bacfdb | 4482 | while (temp) |
15e088b2 | 4483 | { |
ff666313 | 4484 | next = XEXP (temp, 1); |
15e088b2 | 4485 | if (reg_overlap_mentioned_p (XEXP (note, 0), XEXP (temp, 0))) |
c9bacfdb KH |
4486 | { |
4487 | /* Splice temp out of list. */ | |
4488 | if (prev) | |
4489 | XEXP (prev, 1) = next; | |
4490 | else | |
4491 | pbi->mem_set_list = next; | |
ff666313 | 4492 | free_EXPR_LIST_node (temp); |
0875baa0 | 4493 | pbi->mem_set_list_len--; |
c9bacfdb | 4494 | } |
15e088b2 | 4495 | else |
c9bacfdb KH |
4496 | prev = temp; |
4497 | temp = next; | |
15e088b2 JL |
4498 | } |
4499 | } | |
4500 | } | |
4501 | } | |
4502 | ||
1288c070 RH |
4503 | /* EXP is either a MEM or a REG. Remove any dependant entries |
4504 | from pbi->mem_set_list. */ | |
4505 | ||
4506 | static void | |
4507 | invalidate_mems_from_set (pbi, exp) | |
4508 | struct propagate_block_info *pbi; | |
4509 | rtx exp; | |
4510 | { | |
4511 | rtx temp = pbi->mem_set_list; | |
4512 | rtx prev = NULL_RTX; | |
4513 | rtx next; | |
4514 | ||
4515 | while (temp) | |
4516 | { | |
4517 | next = XEXP (temp, 1); | |
4518 | if ((GET_CODE (exp) == MEM | |
4519 | && output_dependence (XEXP (temp, 0), exp)) | |
4520 | || (GET_CODE (exp) == REG | |
4521 | && reg_overlap_mentioned_p (exp, XEXP (temp, 0)))) | |
4522 | { | |
4523 | /* Splice this entry out of the list. */ | |
4524 | if (prev) | |
4525 | XEXP (prev, 1) = next; | |
4526 | else | |
4527 | pbi->mem_set_list = next; | |
4528 | free_EXPR_LIST_node (temp); | |
0875baa0 | 4529 | pbi->mem_set_list_len--; |
1288c070 RH |
4530 | } |
4531 | else | |
4532 | prev = temp; | |
4533 | temp = next; | |
4534 | } | |
4535 | } | |
4536 | ||
d3a923ee RH |
4537 | /* Process the registers that are set within X. Their bits are set to |
4538 | 1 in the regset DEAD, because they are dead prior to this insn. | |
d7429b6a | 4539 | |
d3a923ee RH |
4540 | If INSN is nonzero, it is the insn being processed. |
4541 | ||
4542 | FLAGS is the set of operations to perform. */ | |
d7429b6a | 4543 | |
d7429b6a | 4544 | static void |
8e3f9094 | 4545 | mark_set_regs (pbi, x, insn) |
62828c00 | 4546 | struct propagate_block_info *pbi; |
62828c00 | 4547 | rtx x, insn; |
d7429b6a | 4548 | { |
62828c00 | 4549 | rtx cond = NULL_RTX; |
8ba7b396 | 4550 | rtx link; |
b4593d17 | 4551 | enum rtx_code code; |
d7429b6a | 4552 | |
8ba7b396 R |
4553 | if (insn) |
4554 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
4555 | { | |
4556 | if (REG_NOTE_KIND (link) == REG_INC) | |
4557 | mark_set_1 (pbi, SET, XEXP (link, 0), | |
4558 | (GET_CODE (x) == COND_EXEC | |
4559 | ? COND_EXEC_TEST (x) : NULL_RTX), | |
4560 | insn, pbi->flags); | |
4561 | } | |
62828c00 | 4562 | retry: |
b4593d17 | 4563 | switch (code = GET_CODE (x)) |
d7429b6a | 4564 | { |
62828c00 RH |
4565 | case SET: |
4566 | case CLOBBER: | |
b4593d17 | 4567 | mark_set_1 (pbi, code, SET_DEST (x), cond, insn, pbi->flags); |
62828c00 RH |
4568 | return; |
4569 | ||
4570 | case COND_EXEC: | |
4571 | cond = COND_EXEC_TEST (x); | |
4572 | x = COND_EXEC_CODE (x); | |
4573 | goto retry; | |
4574 | ||
4575 | case PARALLEL: | |
4576 | { | |
4577 | register int i; | |
4578 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
4579 | { | |
4580 | rtx sub = XVECEXP (x, 0, i); | |
b4593d17 | 4581 | switch (code = GET_CODE (sub)) |
62828c00 RH |
4582 | { |
4583 | case COND_EXEC: | |
4584 | if (cond != NULL_RTX) | |
4585 | abort (); | |
4586 | ||
4587 | cond = COND_EXEC_TEST (sub); | |
4588 | sub = COND_EXEC_CODE (sub); | |
4589 | if (GET_CODE (sub) != SET && GET_CODE (sub) != CLOBBER) | |
4590 | break; | |
c9bacfdb | 4591 | /* Fall through. */ |
62828c00 RH |
4592 | |
4593 | case SET: | |
4594 | case CLOBBER: | |
b4593d17 | 4595 | mark_set_1 (pbi, code, SET_DEST (sub), cond, insn, pbi->flags); |
62828c00 RH |
4596 | break; |
4597 | ||
4598 | default: | |
4599 | break; | |
4600 | } | |
4601 | } | |
4602 | break; | |
4603 | } | |
4604 | ||
4605 | default: | |
4606 | break; | |
d7429b6a RK |
4607 | } |
4608 | } | |
4609 | ||
4610 | /* Process a single SET rtx, X. */ | |
4611 | ||
4612 | static void | |
b4593d17 | 4613 | mark_set_1 (pbi, code, reg, cond, insn, flags) |
62828c00 | 4614 | struct propagate_block_info *pbi; |
b4593d17 | 4615 | enum rtx_code code; |
62828c00 | 4616 | rtx reg, cond, insn; |
b4593d17 | 4617 | int flags; |
d7429b6a | 4618 | { |
b4593d17 | 4619 | int regno_first = -1, regno_last = -1; |
3c88f366 | 4620 | unsigned long not_dead = 0; |
b4593d17 | 4621 | int i; |
d7429b6a | 4622 | |
8e3f9094 RH |
4623 | /* Modifying just one hardware register of a multi-reg value or just a |
4624 | byte field of a register does not mean the value from before this insn | |
9785c68d | 4625 | is now dead. Of course, if it was dead after it's unused now. */ |
8e3f9094 | 4626 | |
9785c68d RH |
4627 | switch (GET_CODE (reg)) |
4628 | { | |
90d036a0 RK |
4629 | case PARALLEL: |
4630 | /* Some targets place small structures in registers for return values of | |
4631 | functions. We have to detect this case specially here to get correct | |
7193d1dc | 4632 | flow information. */ |
90d036a0 | 4633 | for (i = XVECLEN (reg, 0) - 1; i >= 0; i--) |
7193d1dc RK |
4634 | if (XEXP (XVECEXP (reg, 0, i), 0) != 0) |
4635 | mark_set_1 (pbi, code, XEXP (XVECEXP (reg, 0, i), 0), cond, insn, | |
4636 | flags); | |
90d036a0 RK |
4637 | return; |
4638 | ||
9785c68d RH |
4639 | case ZERO_EXTRACT: |
4640 | case SIGN_EXTRACT: | |
4641 | case STRICT_LOW_PART: | |
4642 | /* ??? Assumes STRICT_LOW_PART not used on multi-word registers. */ | |
4643 | do | |
4644 | reg = XEXP (reg, 0); | |
4645 | while (GET_CODE (reg) == SUBREG | |
4646 | || GET_CODE (reg) == ZERO_EXTRACT | |
4647 | || GET_CODE (reg) == SIGN_EXTRACT | |
4648 | || GET_CODE (reg) == STRICT_LOW_PART); | |
1b513b77 JH |
4649 | if (GET_CODE (reg) == MEM) |
4650 | break; | |
3c88f366 | 4651 | not_dead = (unsigned long) REGNO_REG_SET_P (pbi->reg_live, REGNO (reg)); |
c9bacfdb | 4652 | /* Fall through. */ |
9785c68d RH |
4653 | |
4654 | case REG: | |
4655 | regno_last = regno_first = REGNO (reg); | |
4656 | if (regno_first < FIRST_PSEUDO_REGISTER) | |
4657 | regno_last += HARD_REGNO_NREGS (regno_first, GET_MODE (reg)) - 1; | |
4658 | break; | |
d7429b6a | 4659 | |
9785c68d RH |
4660 | case SUBREG: |
4661 | if (GET_CODE (SUBREG_REG (reg)) == REG) | |
4662 | { | |
4663 | enum machine_mode outer_mode = GET_MODE (reg); | |
4664 | enum machine_mode inner_mode = GET_MODE (SUBREG_REG (reg)); | |
d7429b6a | 4665 | |
9785c68d RH |
4666 | /* Identify the range of registers affected. This is moderately |
4667 | tricky for hard registers. See alter_subreg. */ | |
4668 | ||
4669 | regno_last = regno_first = REGNO (SUBREG_REG (reg)); | |
4670 | if (regno_first < FIRST_PSEUDO_REGISTER) | |
4671 | { | |
ddef6bc7 JJ |
4672 | regno_first += subreg_regno_offset (regno_first, inner_mode, |
4673 | SUBREG_BYTE (reg), | |
4674 | outer_mode); | |
9785c68d RH |
4675 | regno_last = (regno_first |
4676 | + HARD_REGNO_NREGS (regno_first, outer_mode) - 1); | |
4677 | ||
4678 | /* Since we've just adjusted the register number ranges, make | |
4679 | sure REG matches. Otherwise some_was_live will be clear | |
4680 | when it shouldn't have been, and we'll create incorrect | |
4681 | REG_UNUSED notes. */ | |
4682 | reg = gen_rtx_REG (outer_mode, regno_first); | |
4683 | } | |
4684 | else | |
4685 | { | |
4686 | /* If the number of words in the subreg is less than the number | |
4687 | of words in the full register, we have a well-defined partial | |
4688 | set. Otherwise the high bits are undefined. | |
4689 | ||
4690 | This is only really applicable to pseudos, since we just took | |
4691 | care of multi-word hard registers. */ | |
4692 | if (((GET_MODE_SIZE (outer_mode) | |
4693 | + UNITS_PER_WORD - 1) / UNITS_PER_WORD) | |
4694 | < ((GET_MODE_SIZE (inner_mode) | |
4695 | + UNITS_PER_WORD - 1) / UNITS_PER_WORD)) | |
3c88f366 RE |
4696 | not_dead = (unsigned long) REGNO_REG_SET_P (pbi->reg_live, |
4697 | regno_first); | |
9785c68d RH |
4698 | |
4699 | reg = SUBREG_REG (reg); | |
4700 | } | |
4701 | } | |
4702 | else | |
4703 | reg = SUBREG_REG (reg); | |
4704 | break; | |
4705 | ||
4706 | default: | |
4707 | break; | |
4708 | } | |
d7429b6a | 4709 | |
c9bacfdb | 4710 | /* If this set is a MEM, then it kills any aliased writes. |
db3a887b | 4711 | If this set is a REG, then it kills any MEMs which use the reg. */ |
b2262f4a | 4712 | if (optimize && (flags & PROP_SCAN_DEAD_CODE)) |
db3a887b | 4713 | { |
62828c00 | 4714 | if (GET_CODE (reg) == MEM || GET_CODE (reg) == REG) |
1288c070 | 4715 | invalidate_mems_from_set (pbi, reg); |
15e088b2 | 4716 | |
d3a923ee RH |
4717 | /* If the memory reference had embedded side effects (autoincrement |
4718 | address modes. Then we may need to kill some entries on the | |
4719 | memory set list. */ | |
4720 | if (insn && GET_CODE (reg) == MEM) | |
62828c00 | 4721 | invalidate_mems_from_autoinc (pbi, insn); |
d3a923ee | 4722 | |
0875baa0 RH |
4723 | if (pbi->mem_set_list_len < MAX_MEM_SET_LIST_LEN |
4724 | && GET_CODE (reg) == MEM && ! side_effects_p (reg) | |
a0ee3b83 RH |
4725 | /* ??? With more effort we could track conditional memory life. */ |
4726 | && ! cond | |
d3a923ee RH |
4727 | /* We do not know the size of a BLKmode store, so we do not track |
4728 | them for redundant store elimination. */ | |
4729 | && GET_MODE (reg) != BLKmode | |
c9bacfdb | 4730 | /* There are no REG_INC notes for SP, so we can't assume we'll see |
d3a923ee RH |
4731 | everything that invalidates it. To be safe, don't eliminate any |
4732 | stores though SP; none of them should be redundant anyway. */ | |
4733 | && ! reg_mentioned_p (stack_pointer_rtx, reg)) | |
c32e1e6f RH |
4734 | { |
4735 | #ifdef AUTO_INC_DEC | |
4736 | /* Store a copy of mem, otherwise the address may be | |
4737 | scrogged by find_auto_inc. */ | |
4738 | if (flags & PROP_AUTOINC) | |
4739 | reg = shallow_copy_rtx (reg); | |
4740 | #endif | |
4741 | pbi->mem_set_list = alloc_EXPR_LIST (0, reg, pbi->mem_set_list); | |
0875baa0 | 4742 | pbi->mem_set_list_len++; |
c32e1e6f | 4743 | } |
d3a923ee | 4744 | } |
d7429b6a RK |
4745 | |
4746 | if (GET_CODE (reg) == REG | |
9785c68d RH |
4747 | && ! (regno_first == FRAME_POINTER_REGNUM |
4748 | && (! reload_completed || frame_pointer_needed)) | |
73a187c1 | 4749 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
b4593d17 | 4750 | && ! (regno_first == HARD_FRAME_POINTER_REGNUM |
e4b8a413 | 4751 | && (! reload_completed || frame_pointer_needed)) |
73a187c1 | 4752 | #endif |
d7e4fe8b | 4753 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
b4593d17 | 4754 | && ! (regno_first == ARG_POINTER_REGNUM && fixed_regs[regno_first]) |
d7e4fe8b | 4755 | #endif |
62828c00 | 4756 | ) |
d7429b6a | 4757 | { |
b4593d17 | 4758 | int some_was_live = 0, some_was_dead = 0; |
d7429b6a | 4759 | |
b4593d17 RH |
4760 | for (i = regno_first; i <= regno_last; ++i) |
4761 | { | |
4762 | int needed_regno = REGNO_REG_SET_P (pbi->reg_live, i); | |
4763 | if (pbi->local_set) | |
7dfc0fbe BS |
4764 | { |
4765 | /* Order of the set operation matters here since both | |
4766 | sets may be the same. */ | |
4767 | CLEAR_REGNO_REG_SET (pbi->cond_local_set, i); | |
4768 | if (cond != NULL_RTX | |
4769 | && ! REGNO_REG_SET_P (pbi->local_set, i)) | |
4770 | SET_REGNO_REG_SET (pbi->cond_local_set, i); | |
4771 | else | |
4772 | SET_REGNO_REG_SET (pbi->local_set, i); | |
4773 | } | |
9785c68d RH |
4774 | if (code != CLOBBER) |
4775 | SET_REGNO_REG_SET (pbi->new_set, i); | |
b4593d17 RH |
4776 | |
4777 | some_was_live |= needed_regno; | |
4778 | some_was_dead |= ! needed_regno; | |
4779 | } | |
d3a923ee | 4780 | |
11ae508b RH |
4781 | #ifdef HAVE_conditional_execution |
4782 | /* Consider conditional death in deciding that the register needs | |
4783 | a death note. */ | |
f0acaf02 | 4784 | if (some_was_live && ! not_dead |
11ae508b RH |
4785 | /* The stack pointer is never dead. Well, not strictly true, |
4786 | but it's very difficult to tell from here. Hopefully | |
4787 | combine_stack_adjustments will fix up the most egregious | |
4788 | errors. */ | |
4789 | && regno_first != STACK_POINTER_REGNUM) | |
4790 | { | |
4791 | for (i = regno_first; i <= regno_last; ++i) | |
4792 | if (! mark_regno_cond_dead (pbi, i, cond)) | |
3c88f366 | 4793 | not_dead |= ((unsigned long) 1) << (i - regno_first); |
11ae508b RH |
4794 | } |
4795 | #endif | |
4796 | ||
d7429b6a | 4797 | /* Additional data to record if this is the final pass. */ |
d3a923ee | 4798 | if (flags & (PROP_LOG_LINKS | PROP_REG_INFO |
fb6754f0 | 4799 | | PROP_DEATH_NOTES | PROP_AUTOINC)) |
d7429b6a | 4800 | { |
d3a923ee | 4801 | register rtx y; |
62828c00 | 4802 | register int blocknum = pbi->bb->index; |
d7429b6a | 4803 | |
d3a923ee RH |
4804 | y = NULL_RTX; |
4805 | if (flags & (PROP_LOG_LINKS | PROP_AUTOINC)) | |
d7429b6a | 4806 | { |
b4593d17 | 4807 | y = pbi->reg_next_use[regno_first]; |
93514916 | 4808 | |
b4593d17 RH |
4809 | /* The next use is no longer next, since a store intervenes. */ |
4810 | for (i = regno_first; i <= regno_last; ++i) | |
4811 | pbi->reg_next_use[i] = 0; | |
d7429b6a | 4812 | } |
93514916 | 4813 | |
b4593d17 RH |
4814 | if (flags & PROP_REG_INFO) |
4815 | { | |
4816 | for (i = regno_first; i <= regno_last; ++i) | |
d3a923ee | 4817 | { |
b4593d17 | 4818 | /* Count (weighted) references, stores, etc. This counts a |
d3a923ee | 4819 | register twice if it is modified, but that is correct. */ |
b4593d17 RH |
4820 | REG_N_SETS (i) += 1; |
4821 | REG_N_REFS (i) += (optimize_size ? 1 | |
4822 | : pbi->bb->loop_depth + 1); | |
4823 | ||
d3a923ee RH |
4824 | /* The insns where a reg is live are normally counted |
4825 | elsewhere, but we want the count to include the insn | |
4826 | where the reg is set, and the normal counting mechanism | |
4827 | would not count it. */ | |
c9bacfdb | 4828 | REG_LIVE_LENGTH (i) += 1; |
b4593d17 RH |
4829 | } |
4830 | ||
4831 | /* If this is a hard reg, record this function uses the reg. */ | |
4832 | if (regno_first < FIRST_PSEUDO_REGISTER) | |
4833 | { | |
4834 | for (i = regno_first; i <= regno_last; i++) | |
4835 | regs_ever_live[i] = 1; | |
4836 | } | |
4837 | else | |
4838 | { | |
4839 | /* Keep track of which basic blocks each reg appears in. */ | |
4840 | if (REG_BASIC_BLOCK (regno_first) == REG_BLOCK_UNKNOWN) | |
4841 | REG_BASIC_BLOCK (regno_first) = blocknum; | |
4842 | else if (REG_BASIC_BLOCK (regno_first) != blocknum) | |
4843 | REG_BASIC_BLOCK (regno_first) = REG_BLOCK_GLOBAL; | |
d3a923ee | 4844 | } |
d7429b6a RK |
4845 | } |
4846 | ||
62828c00 | 4847 | if (! some_was_dead) |
d7429b6a | 4848 | { |
d3a923ee RH |
4849 | if (flags & PROP_LOG_LINKS) |
4850 | { | |
4851 | /* Make a logical link from the next following insn | |
4852 | that uses this register, back to this insn. | |
4853 | The following insns have already been processed. | |
4854 | ||
4855 | We don't build a LOG_LINK for hard registers containing | |
4856 | in ASM_OPERANDs. If these registers get replaced, | |
4857 | we might wind up changing the semantics of the insn, | |
4858 | even if reload can make what appear to be valid | |
4859 | assignments later. */ | |
4860 | if (y && (BLOCK_NUM (y) == blocknum) | |
b4593d17 | 4861 | && (regno_first >= FIRST_PSEUDO_REGISTER |
d3a923ee RH |
4862 | || asm_noperands (PATTERN (y)) < 0)) |
4863 | LOG_LINKS (y) = alloc_INSN_LIST (insn, LOG_LINKS (y)); | |
4864 | } | |
d7429b6a | 4865 | } |
9785c68d RH |
4866 | else if (not_dead) |
4867 | ; | |
62828c00 | 4868 | else if (! some_was_live) |
d7429b6a | 4869 | { |
d3a923ee | 4870 | if (flags & PROP_REG_INFO) |
b4593d17 | 4871 | REG_N_DEATHS (regno_first) += 1; |
d3a923ee RH |
4872 | |
4873 | if (flags & PROP_DEATH_NOTES) | |
4874 | { | |
4875 | /* Note that dead stores have already been deleted | |
4876 | when possible. If we get here, we have found a | |
4877 | dead store that cannot be eliminated (because the | |
4878 | same insn does something useful). Indicate this | |
4879 | by marking the reg being set as dying here. */ | |
4880 | REG_NOTES (insn) | |
4881 | = alloc_EXPR_LIST (REG_UNUSED, reg, REG_NOTES (insn)); | |
4882 | } | |
d7429b6a RK |
4883 | } |
4884 | else | |
4885 | { | |
d3a923ee RH |
4886 | if (flags & PROP_DEATH_NOTES) |
4887 | { | |
4888 | /* This is a case where we have a multi-word hard register | |
4889 | and some, but not all, of the words of the register are | |
4890 | needed in subsequent insns. Write REG_UNUSED notes | |
4891 | for those parts that were not needed. This case should | |
4892 | be rare. */ | |
4893 | ||
b4593d17 RH |
4894 | for (i = regno_first; i <= regno_last; ++i) |
4895 | if (! REGNO_REG_SET_P (pbi->reg_live, i)) | |
d3a923ee | 4896 | REG_NOTES (insn) |
b4593d17 RH |
4897 | = alloc_EXPR_LIST (REG_UNUSED, |
4898 | gen_rtx_REG (reg_raw_mode[i], i), | |
4899 | REG_NOTES (insn)); | |
d3a923ee | 4900 | } |
d7429b6a RK |
4901 | } |
4902 | } | |
b4593d17 RH |
4903 | |
4904 | /* Mark the register as being dead. */ | |
4905 | if (some_was_live | |
4906 | /* The stack pointer is never dead. Well, not strictly true, | |
4907 | but it's very difficult to tell from here. Hopefully | |
4908 | combine_stack_adjustments will fix up the most egregious | |
4909 | errors. */ | |
4910 | && regno_first != STACK_POINTER_REGNUM) | |
4911 | { | |
4912 | for (i = regno_first; i <= regno_last; ++i) | |
3c88f366 RE |
4913 | if (!(not_dead & (((unsigned long) 1) << (i - regno_first)))) |
4914 | CLEAR_REGNO_REG_SET (pbi->reg_live, i); | |
b4593d17 | 4915 | } |
d7429b6a | 4916 | } |
8244fc4f | 4917 | else if (GET_CODE (reg) == REG) |
d3a923ee RH |
4918 | { |
4919 | if (flags & (PROP_LOG_LINKS | PROP_AUTOINC)) | |
b4593d17 | 4920 | pbi->reg_next_use[regno_first] = 0; |
d3a923ee | 4921 | } |
d7429b6a RK |
4922 | |
4923 | /* If this is the last pass and this is a SCRATCH, show it will be dying | |
4924 | here and count it. */ | |
d3a923ee | 4925 | else if (GET_CODE (reg) == SCRATCH) |
d7429b6a | 4926 | { |
d3a923ee RH |
4927 | if (flags & PROP_DEATH_NOTES) |
4928 | REG_NOTES (insn) | |
4929 | = alloc_EXPR_LIST (REG_UNUSED, reg, REG_NOTES (insn)); | |
d7429b6a RK |
4930 | } |
4931 | } | |
4932 | \f | |
11ae508b | 4933 | #ifdef HAVE_conditional_execution |
c9bacfdb KH |
4934 | /* Mark REGNO conditionally dead. |
4935 | Return true if the register is now unconditionally dead. */ | |
11ae508b RH |
4936 | |
4937 | static int | |
4938 | mark_regno_cond_dead (pbi, regno, cond) | |
4939 | struct propagate_block_info *pbi; | |
4940 | int regno; | |
4941 | rtx cond; | |
4942 | { | |
4943 | /* If this is a store to a predicate register, the value of the | |
4944 | predicate is changing, we don't know that the predicate as seen | |
4eb00163 | 4945 | before is the same as that seen after. Flush all dependent |
11ae508b RH |
4946 | conditions from reg_cond_dead. This will make all such |
4947 | conditionally live registers unconditionally live. */ | |
4948 | if (REGNO_REG_SET_P (pbi->reg_cond_reg, regno)) | |
4949 | flush_reg_cond_reg (pbi, regno); | |
4950 | ||
4951 | /* If this is an unconditional store, remove any conditional | |
4952 | life that may have existed. */ | |
4953 | if (cond == NULL_RTX) | |
4954 | splay_tree_remove (pbi->reg_cond_dead, regno); | |
4955 | else | |
4956 | { | |
4957 | splay_tree_node node; | |
4958 | struct reg_cond_life_info *rcli; | |
4959 | rtx ncond; | |
4960 | ||
4961 | /* Otherwise this is a conditional set. Record that fact. | |
4962 | It may have been conditionally used, or there may be a | |
4963 | subsequent set with a complimentary condition. */ | |
4964 | ||
4965 | node = splay_tree_lookup (pbi->reg_cond_dead, regno); | |
4966 | if (node == NULL) | |
4967 | { | |
4968 | /* The register was unconditionally live previously. | |
4969 | Record the current condition as the condition under | |
4970 | which it is dead. */ | |
c9bacfdb | 4971 | rcli = (struct reg_cond_life_info *) xmalloc (sizeof (*rcli)); |
288c2c9e | 4972 | rcli->condition = cond; |
685af3af JW |
4973 | rcli->stores = cond; |
4974 | rcli->orig_condition = const0_rtx; | |
11ae508b RH |
4975 | splay_tree_insert (pbi->reg_cond_dead, regno, |
4976 | (splay_tree_value) rcli); | |
4977 | ||
7791b7f9 | 4978 | SET_REGNO_REG_SET (pbi->reg_cond_reg, REGNO (XEXP (cond, 0))); |
11ae508b RH |
4979 | |
4980 | /* Not unconditionaly dead. */ | |
4981 | return 0; | |
4982 | } | |
4983 | else | |
4984 | { | |
c9bacfdb | 4985 | /* The register was conditionally live previously. |
11ae508b RH |
4986 | Add the new condition to the old. */ |
4987 | rcli = (struct reg_cond_life_info *) node->value; | |
4988 | ncond = rcli->condition; | |
288c2c9e | 4989 | ncond = ior_reg_cond (ncond, cond, 1); |
685af3af JW |
4990 | if (rcli->stores == const0_rtx) |
4991 | rcli->stores = cond; | |
4992 | else if (rcli->stores != const1_rtx) | |
4993 | rcli->stores = ior_reg_cond (rcli->stores, cond, 1); | |
4994 | ||
4995 | /* If the register is now unconditionally dead, remove the entry | |
4996 | in the splay_tree. A register is unconditionally dead if the | |
4997 | dead condition ncond is true. A register is also unconditionally | |
4998 | dead if the sum of all conditional stores is an unconditional | |
4999 | store (stores is true), and the dead condition is identically the | |
5000 | same as the original dead condition initialized at the end of | |
5001 | the block. This is a pointer compare, not an rtx_equal_p | |
5002 | compare. */ | |
5003 | if (ncond == const1_rtx | |
5004 | || (ncond == rcli->orig_condition && rcli->stores == const1_rtx)) | |
11ae508b RH |
5005 | splay_tree_remove (pbi->reg_cond_dead, regno); |
5006 | else | |
5007 | { | |
5008 | rcli->condition = ncond; | |
5009 | ||
7791b7f9 | 5010 | SET_REGNO_REG_SET (pbi->reg_cond_reg, REGNO (XEXP (cond, 0))); |
11ae508b RH |
5011 | |
5012 | /* Not unconditionaly dead. */ | |
5013 | return 0; | |
5014 | } | |
5015 | } | |
5016 | } | |
5017 | ||
5018 | return 1; | |
5019 | } | |
5020 | ||
5021 | /* Called from splay_tree_delete for pbi->reg_cond_life. */ | |
5022 | ||
5023 | static void | |
5024 | free_reg_cond_life_info (value) | |
5025 | splay_tree_value value; | |
5026 | { | |
5027 | struct reg_cond_life_info *rcli = (struct reg_cond_life_info *) value; | |
11ae508b RH |
5028 | free (rcli); |
5029 | } | |
5030 | ||
5031 | /* Helper function for flush_reg_cond_reg. */ | |
5032 | ||
5033 | static int | |
5034 | flush_reg_cond_reg_1 (node, data) | |
5035 | splay_tree_node node; | |
5036 | void *data; | |
5037 | { | |
5038 | struct reg_cond_life_info *rcli; | |
5039 | int *xdata = (int *) data; | |
5040 | unsigned int regno = xdata[0]; | |
11ae508b RH |
5041 | |
5042 | /* Don't need to search if last flushed value was farther on in | |
5043 | the in-order traversal. */ | |
5044 | if (xdata[1] >= (int) node->key) | |
5045 | return 0; | |
21c7361e | 5046 | |
11ae508b RH |
5047 | /* Splice out portions of the expression that refer to regno. */ |
5048 | rcli = (struct reg_cond_life_info *) node->value; | |
288c2c9e | 5049 | rcli->condition = elim_reg_cond (rcli->condition, regno); |
685af3af JW |
5050 | if (rcli->stores != const0_rtx && rcli->stores != const1_rtx) |
5051 | rcli->stores = elim_reg_cond (rcli->stores, regno); | |
11ae508b | 5052 | |
288c2c9e BS |
5053 | /* If the entire condition is now false, signal the node to be removed. */ |
5054 | if (rcli->condition == const0_rtx) | |
11ae508b RH |
5055 | { |
5056 | xdata[1] = node->key; | |
5057 | return -1; | |
5058 | } | |
288c2c9e BS |
5059 | else if (rcli->condition == const1_rtx) |
5060 | abort (); | |
5061 | ||
5062 | return 0; | |
11ae508b RH |
5063 | } |
5064 | ||
5065 | /* Flush all (sub) expressions referring to REGNO from REG_COND_LIVE. */ | |
5066 | ||
5067 | static void | |
5068 | flush_reg_cond_reg (pbi, regno) | |
5069 | struct propagate_block_info *pbi; | |
5070 | int regno; | |
5071 | { | |
5072 | int pair[2]; | |
5073 | ||
5074 | pair[0] = regno; | |
5075 | pair[1] = -1; | |
5076 | while (splay_tree_foreach (pbi->reg_cond_dead, | |
5077 | flush_reg_cond_reg_1, pair) == -1) | |
5078 | splay_tree_remove (pbi->reg_cond_dead, pair[1]); | |
5079 | ||
5080 | CLEAR_REGNO_REG_SET (pbi->reg_cond_reg, regno); | |
5081 | } | |
5082 | ||
288c2c9e BS |
5083 | /* Logical arithmetic on predicate conditions. IOR, NOT and AND. |
5084 | For ior/and, the ADD flag determines whether we want to add the new | |
5085 | condition X to the old one unconditionally. If it is zero, we will | |
5086 | only return a new expression if X allows us to simplify part of | |
5087 | OLD, otherwise we return OLD unchanged to the caller. | |
5088 | If ADD is nonzero, we will return a new condition in all cases. The | |
5089 | toplevel caller of one of these functions should always pass 1 for | |
5090 | ADD. */ | |
11ae508b RH |
5091 | |
5092 | static rtx | |
288c2c9e | 5093 | ior_reg_cond (old, x, add) |
11ae508b | 5094 | rtx old, x; |
288c2c9e | 5095 | int add; |
11ae508b | 5096 | { |
288c2c9e | 5097 | rtx op0, op1; |
11ae508b | 5098 | |
fd7bcd6f BS |
5099 | if (GET_RTX_CLASS (GET_CODE (old)) == '<') |
5100 | { | |
5101 | if (GET_RTX_CLASS (GET_CODE (x)) == '<' | |
7e6d8ba1 | 5102 | && REVERSE_CONDEXEC_PREDICATES_P (GET_CODE (x), GET_CODE (old)) |
fd7bcd6f BS |
5103 | && REGNO (XEXP (x, 0)) == REGNO (XEXP (old, 0))) |
5104 | return const1_rtx; | |
5105 | if (GET_CODE (x) == GET_CODE (old) | |
5106 | && REGNO (XEXP (x, 0)) == REGNO (XEXP (old, 0))) | |
5107 | return old; | |
5108 | if (! add) | |
5109 | return old; | |
5110 | return gen_rtx_IOR (0, old, x); | |
5111 | } | |
5112 | ||
288c2c9e | 5113 | switch (GET_CODE (old)) |
11ae508b | 5114 | { |
288c2c9e BS |
5115 | case IOR: |
5116 | op0 = ior_reg_cond (XEXP (old, 0), x, 0); | |
5117 | op1 = ior_reg_cond (XEXP (old, 1), x, 0); | |
5118 | if (op0 != XEXP (old, 0) || op1 != XEXP (old, 1)) | |
11ae508b | 5119 | { |
288c2c9e BS |
5120 | if (op0 == const0_rtx) |
5121 | return op1; | |
5122 | if (op1 == const0_rtx) | |
5123 | return op0; | |
5124 | if (op0 == const1_rtx || op1 == const1_rtx) | |
11ae508b | 5125 | return const1_rtx; |
288c2c9e BS |
5126 | if (op0 == XEXP (old, 0)) |
5127 | op0 = gen_rtx_IOR (0, op0, x); | |
5128 | else | |
5129 | op1 = gen_rtx_IOR (0, op1, x); | |
5130 | return gen_rtx_IOR (0, op0, op1); | |
11ae508b | 5131 | } |
288c2c9e BS |
5132 | if (! add) |
5133 | return old; | |
5134 | return gen_rtx_IOR (0, old, x); | |
5135 | ||
5136 | case AND: | |
5137 | op0 = ior_reg_cond (XEXP (old, 0), x, 0); | |
5138 | op1 = ior_reg_cond (XEXP (old, 1), x, 0); | |
5139 | if (op0 != XEXP (old, 0) || op1 != XEXP (old, 1)) | |
5140 | { | |
5141 | if (op0 == const1_rtx) | |
5142 | return op1; | |
5143 | if (op1 == const1_rtx) | |
5144 | return op0; | |
5145 | if (op0 == const0_rtx || op1 == const0_rtx) | |
5146 | return const0_rtx; | |
5147 | if (op0 == XEXP (old, 0)) | |
5148 | op0 = gen_rtx_IOR (0, op0, x); | |
5149 | else | |
5150 | op1 = gen_rtx_IOR (0, op1, x); | |
5151 | return gen_rtx_AND (0, op0, op1); | |
5152 | } | |
5153 | if (! add) | |
5154 | return old; | |
5155 | return gen_rtx_IOR (0, old, x); | |
5156 | ||
5157 | case NOT: | |
5158 | op0 = and_reg_cond (XEXP (old, 0), not_reg_cond (x), 0); | |
5159 | if (op0 != XEXP (old, 0)) | |
5160 | return not_reg_cond (op0); | |
5161 | if (! add) | |
5162 | return old; | |
5163 | return gen_rtx_IOR (0, old, x); | |
5164 | ||
288c2c9e BS |
5165 | default: |
5166 | abort (); | |
5167 | } | |
11ae508b RH |
5168 | } |
5169 | ||
5170 | static rtx | |
5171 | not_reg_cond (x) | |
5172 | rtx x; | |
5173 | { | |
5174 | enum rtx_code x_code; | |
11ae508b | 5175 | |
288c2c9e BS |
5176 | if (x == const0_rtx) |
5177 | return const1_rtx; | |
5178 | else if (x == const1_rtx) | |
5179 | return const0_rtx; | |
11ae508b | 5180 | x_code = GET_CODE (x); |
288c2c9e BS |
5181 | if (x_code == NOT) |
5182 | return XEXP (x, 0); | |
5183 | if (GET_RTX_CLASS (x_code) == '<' | |
5184 | && GET_CODE (XEXP (x, 0)) == REG) | |
5185 | { | |
5186 | if (XEXP (x, 1) != const0_rtx) | |
5187 | abort (); | |
11ae508b | 5188 | |
288c2c9e BS |
5189 | return gen_rtx_fmt_ee (reverse_condition (x_code), |
5190 | VOIDmode, XEXP (x, 0), const0_rtx); | |
5191 | } | |
5192 | return gen_rtx_NOT (0, x); | |
11ae508b RH |
5193 | } |
5194 | ||
5195 | static rtx | |
288c2c9e | 5196 | and_reg_cond (old, x, add) |
11ae508b | 5197 | rtx old, x; |
288c2c9e | 5198 | int add; |
11ae508b | 5199 | { |
288c2c9e | 5200 | rtx op0, op1; |
11ae508b | 5201 | |
fd7bcd6f BS |
5202 | if (GET_RTX_CLASS (GET_CODE (old)) == '<') |
5203 | { | |
5204 | if (GET_RTX_CLASS (GET_CODE (x)) == '<' | |
5205 | && GET_CODE (x) == reverse_condition (GET_CODE (old)) | |
5206 | && REGNO (XEXP (x, 0)) == REGNO (XEXP (old, 0))) | |
5207 | return const0_rtx; | |
5208 | if (GET_CODE (x) == GET_CODE (old) | |
5209 | && REGNO (XEXP (x, 0)) == REGNO (XEXP (old, 0))) | |
5210 | return old; | |
5211 | if (! add) | |
5212 | return old; | |
5213 | return gen_rtx_AND (0, old, x); | |
5214 | } | |
5215 | ||
288c2c9e | 5216 | switch (GET_CODE (old)) |
11ae508b | 5217 | { |
288c2c9e BS |
5218 | case IOR: |
5219 | op0 = and_reg_cond (XEXP (old, 0), x, 0); | |
5220 | op1 = and_reg_cond (XEXP (old, 1), x, 0); | |
5221 | if (op0 != XEXP (old, 0) || op1 != XEXP (old, 1)) | |
11ae508b | 5222 | { |
288c2c9e BS |
5223 | if (op0 == const0_rtx) |
5224 | return op1; | |
5225 | if (op1 == const0_rtx) | |
5226 | return op0; | |
5227 | if (op0 == const1_rtx || op1 == const1_rtx) | |
5228 | return const1_rtx; | |
5229 | if (op0 == XEXP (old, 0)) | |
5230 | op0 = gen_rtx_AND (0, op0, x); | |
5231 | else | |
5232 | op1 = gen_rtx_AND (0, op1, x); | |
5233 | return gen_rtx_IOR (0, op0, op1); | |
11ae508b | 5234 | } |
288c2c9e BS |
5235 | if (! add) |
5236 | return old; | |
5237 | return gen_rtx_AND (0, old, x); | |
5238 | ||
5239 | case AND: | |
5240 | op0 = and_reg_cond (XEXP (old, 0), x, 0); | |
5241 | op1 = and_reg_cond (XEXP (old, 1), x, 0); | |
5242 | if (op0 != XEXP (old, 0) || op1 != XEXP (old, 1)) | |
5243 | { | |
5244 | if (op0 == const1_rtx) | |
5245 | return op1; | |
5246 | if (op1 == const1_rtx) | |
5247 | return op0; | |
5248 | if (op0 == const0_rtx || op1 == const0_rtx) | |
5249 | return const0_rtx; | |
5250 | if (op0 == XEXP (old, 0)) | |
5251 | op0 = gen_rtx_AND (0, op0, x); | |
5252 | else | |
5253 | op1 = gen_rtx_AND (0, op1, x); | |
5254 | return gen_rtx_AND (0, op0, op1); | |
5255 | } | |
5256 | if (! add) | |
5257 | return old; | |
685af3af JW |
5258 | |
5259 | /* If X is identical to one of the existing terms of the AND, | |
5260 | then just return what we already have. */ | |
5261 | /* ??? There really should be some sort of recursive check here in | |
5262 | case there are nested ANDs. */ | |
5263 | if ((GET_CODE (XEXP (old, 0)) == GET_CODE (x) | |
5264 | && REGNO (XEXP (XEXP (old, 0), 0)) == REGNO (XEXP (x, 0))) | |
5265 | || (GET_CODE (XEXP (old, 1)) == GET_CODE (x) | |
5266 | && REGNO (XEXP (XEXP (old, 1), 0)) == REGNO (XEXP (x, 0)))) | |
5267 | return old; | |
5268 | ||
288c2c9e BS |
5269 | return gen_rtx_AND (0, old, x); |
5270 | ||
5271 | case NOT: | |
5272 | op0 = ior_reg_cond (XEXP (old, 0), not_reg_cond (x), 0); | |
5273 | if (op0 != XEXP (old, 0)) | |
5274 | return not_reg_cond (op0); | |
5275 | if (! add) | |
5276 | return old; | |
5277 | return gen_rtx_AND (0, old, x); | |
5278 | ||
288c2c9e BS |
5279 | default: |
5280 | abort (); | |
11ae508b | 5281 | } |
288c2c9e BS |
5282 | } |
5283 | ||
5284 | /* Given a condition X, remove references to reg REGNO and return the | |
5285 | new condition. The removal will be done so that all conditions | |
5286 | involving REGNO are considered to evaluate to false. This function | |
5287 | is used when the value of REGNO changes. */ | |
11ae508b | 5288 | |
288c2c9e BS |
5289 | static rtx |
5290 | elim_reg_cond (x, regno) | |
5291 | rtx x; | |
5292 | unsigned int regno; | |
5293 | { | |
5294 | rtx op0, op1; | |
fd7bcd6f BS |
5295 | |
5296 | if (GET_RTX_CLASS (GET_CODE (x)) == '<') | |
5297 | { | |
5298 | if (REGNO (XEXP (x, 0)) == regno) | |
5299 | return const0_rtx; | |
5300 | return x; | |
5301 | } | |
5302 | ||
288c2c9e BS |
5303 | switch (GET_CODE (x)) |
5304 | { | |
5305 | case AND: | |
5306 | op0 = elim_reg_cond (XEXP (x, 0), regno); | |
5307 | op1 = elim_reg_cond (XEXP (x, 1), regno); | |
5308 | if (op0 == const0_rtx || op1 == const0_rtx) | |
5309 | return const0_rtx; | |
5310 | if (op0 == const1_rtx) | |
5311 | return op1; | |
5312 | if (op1 == const1_rtx) | |
5313 | return op0; | |
5314 | if (op0 == XEXP (x, 0) && op1 == XEXP (x, 1)) | |
5315 | return x; | |
5316 | return gen_rtx_AND (0, op0, op1); | |
5317 | ||
5318 | case IOR: | |
5319 | op0 = elim_reg_cond (XEXP (x, 0), regno); | |
5320 | op1 = elim_reg_cond (XEXP (x, 1), regno); | |
5321 | if (op0 == const1_rtx || op1 == const1_rtx) | |
5322 | return const1_rtx; | |
5323 | if (op0 == const0_rtx) | |
5324 | return op1; | |
5325 | if (op1 == const0_rtx) | |
5326 | return op0; | |
5327 | if (op0 == XEXP (x, 0) && op1 == XEXP (x, 1)) | |
5328 | return x; | |
5329 | return gen_rtx_IOR (0, op0, op1); | |
5330 | ||
5331 | case NOT: | |
5332 | op0 = elim_reg_cond (XEXP (x, 0), regno); | |
5333 | if (op0 == const0_rtx) | |
5334 | return const1_rtx; | |
5335 | if (op0 == const1_rtx) | |
5336 | return const0_rtx; | |
5337 | if (op0 != XEXP (x, 0)) | |
5338 | return not_reg_cond (op0); | |
5339 | return x; | |
5340 | ||
288c2c9e BS |
5341 | default: |
5342 | abort (); | |
5343 | } | |
11ae508b RH |
5344 | } |
5345 | #endif /* HAVE_conditional_execution */ | |
5346 | \f | |
d7429b6a RK |
5347 | #ifdef AUTO_INC_DEC |
5348 | ||
4b983fdc RH |
5349 | /* Try to substitute the auto-inc expression INC as the address inside |
5350 | MEM which occurs in INSN. Currently, the address of MEM is an expression | |
5351 | involving INCR_REG, and INCR is the next use of INCR_REG; it is an insn | |
5352 | that has a single set whose source is a PLUS of INCR_REG and something | |
5353 | else. */ | |
5354 | ||
5355 | static void | |
5356 | attempt_auto_inc (pbi, inc, insn, mem, incr, incr_reg) | |
5357 | struct propagate_block_info *pbi; | |
5358 | rtx inc, insn, mem, incr, incr_reg; | |
5359 | { | |
5360 | int regno = REGNO (incr_reg); | |
5361 | rtx set = single_set (incr); | |
5362 | rtx q = SET_DEST (set); | |
5363 | rtx y = SET_SRC (set); | |
5364 | int opnum = XEXP (y, 0) == incr_reg ? 0 : 1; | |
5365 | ||
5366 | /* Make sure this reg appears only once in this insn. */ | |
5367 | if (count_occurrences (PATTERN (insn), incr_reg, 1) != 1) | |
5368 | return; | |
5369 | ||
5370 | if (dead_or_set_p (incr, incr_reg) | |
5371 | /* Mustn't autoinc an eliminable register. */ | |
5372 | && (regno >= FIRST_PSEUDO_REGISTER | |
5373 | || ! TEST_HARD_REG_BIT (elim_reg_set, regno))) | |
5374 | { | |
5375 | /* This is the simple case. Try to make the auto-inc. If | |
5376 | we can't, we are done. Otherwise, we will do any | |
5377 | needed updates below. */ | |
5378 | if (! validate_change (insn, &XEXP (mem, 0), inc, 0)) | |
5379 | return; | |
5380 | } | |
5381 | else if (GET_CODE (q) == REG | |
5382 | /* PREV_INSN used here to check the semi-open interval | |
5383 | [insn,incr). */ | |
5384 | && ! reg_used_between_p (q, PREV_INSN (insn), incr) | |
5385 | /* We must also check for sets of q as q may be | |
5386 | a call clobbered hard register and there may | |
5387 | be a call between PREV_INSN (insn) and incr. */ | |
5388 | && ! reg_set_between_p (q, PREV_INSN (insn), incr)) | |
5389 | { | |
5390 | /* We have *p followed sometime later by q = p+size. | |
5391 | Both p and q must be live afterward, | |
5392 | and q is not used between INSN and its assignment. | |
5393 | Change it to q = p, ...*q..., q = q+size. | |
5394 | Then fall into the usual case. */ | |
5395 | rtx insns, temp; | |
4b983fdc RH |
5396 | |
5397 | start_sequence (); | |
5398 | emit_move_insn (q, incr_reg); | |
5399 | insns = get_insns (); | |
5400 | end_sequence (); | |
5401 | ||
5402 | if (basic_block_for_insn) | |
5403 | for (temp = insns; temp; temp = NEXT_INSN (temp)) | |
5404 | set_block_for_insn (temp, pbi->bb); | |
5405 | ||
5406 | /* If we can't make the auto-inc, or can't make the | |
5407 | replacement into Y, exit. There's no point in making | |
5408 | the change below if we can't do the auto-inc and doing | |
5409 | so is not correct in the pre-inc case. */ | |
5410 | ||
5411 | XEXP (inc, 0) = q; | |
5412 | validate_change (insn, &XEXP (mem, 0), inc, 1); | |
5413 | validate_change (incr, &XEXP (y, opnum), q, 1); | |
5414 | if (! apply_change_group ()) | |
5415 | return; | |
5416 | ||
5417 | /* We now know we'll be doing this change, so emit the | |
5418 | new insn(s) and do the updates. */ | |
5419 | emit_insns_before (insns, insn); | |
5420 | ||
5421 | if (pbi->bb->head == insn) | |
5422 | pbi->bb->head = insns; | |
5423 | ||
5424 | /* INCR will become a NOTE and INSN won't contain a | |
5425 | use of INCR_REG. If a use of INCR_REG was just placed in | |
c9bacfdb | 5426 | the insn before INSN, make that the next use. |
4b983fdc RH |
5427 | Otherwise, invalidate it. */ |
5428 | if (GET_CODE (PREV_INSN (insn)) == INSN | |
5429 | && GET_CODE (PATTERN (PREV_INSN (insn))) == SET | |
5430 | && SET_SRC (PATTERN (PREV_INSN (insn))) == incr_reg) | |
5431 | pbi->reg_next_use[regno] = PREV_INSN (insn); | |
5432 | else | |
5433 | pbi->reg_next_use[regno] = 0; | |
5434 | ||
5435 | incr_reg = q; | |
5436 | regno = REGNO (q); | |
5437 | ||
5438 | /* REGNO is now used in INCR which is below INSN, but | |
5439 | it previously wasn't live here. If we don't mark | |
5440 | it as live, we'll put a REG_DEAD note for it | |
5441 | on this insn, which is incorrect. */ | |
5442 | SET_REGNO_REG_SET (pbi->reg_live, regno); | |
5443 | ||
5444 | /* If there are any calls between INSN and INCR, show | |
5445 | that REGNO now crosses them. */ | |
5446 | for (temp = insn; temp != incr; temp = NEXT_INSN (temp)) | |
5447 | if (GET_CODE (temp) == CALL_INSN) | |
5448 | REG_N_CALLS_CROSSED (regno)++; | |
5449 | } | |
5450 | else | |
5451 | return; | |
5452 | ||
5453 | /* If we haven't returned, it means we were able to make the | |
5454 | auto-inc, so update the status. First, record that this insn | |
5455 | has an implicit side effect. */ | |
5456 | ||
c9bacfdb | 5457 | REG_NOTES (insn) = alloc_EXPR_LIST (REG_INC, incr_reg, REG_NOTES (insn)); |
4b983fdc RH |
5458 | |
5459 | /* Modify the old increment-insn to simply copy | |
5460 | the already-incremented value of our register. */ | |
5461 | if (! validate_change (incr, &SET_SRC (set), incr_reg, 0)) | |
5462 | abort (); | |
5463 | ||
5464 | /* If that makes it a no-op (copying the register into itself) delete | |
5465 | it so it won't appear to be a "use" and a "set" of this | |
5466 | register. */ | |
5467 | if (REGNO (SET_DEST (set)) == REGNO (incr_reg)) | |
5468 | { | |
5469 | /* If the original source was dead, it's dead now. */ | |
5470 | rtx note; | |
c9bacfdb | 5471 | |
0858c623 | 5472 | while ((note = find_reg_note (incr, REG_DEAD, NULL_RTX)) != NULL_RTX) |
4b983fdc RH |
5473 | { |
5474 | remove_note (incr, note); | |
5475 | if (XEXP (note, 0) != incr_reg) | |
5476 | CLEAR_REGNO_REG_SET (pbi->reg_live, REGNO (XEXP (note, 0))); | |
5477 | } | |
5478 | ||
5479 | PUT_CODE (incr, NOTE); | |
5480 | NOTE_LINE_NUMBER (incr) = NOTE_INSN_DELETED; | |
5481 | NOTE_SOURCE_FILE (incr) = 0; | |
5482 | } | |
5483 | ||
5484 | if (regno >= FIRST_PSEUDO_REGISTER) | |
5485 | { | |
5486 | /* Count an extra reference to the reg. When a reg is | |
5487 | incremented, spilling it is worse, so we want to make | |
5488 | that less likely. */ | |
5489 | REG_N_REFS (regno) += (optimize_size ? 1 : pbi->bb->loop_depth + 1); | |
5490 | ||
5491 | /* Count the increment as a setting of the register, | |
5492 | even though it isn't a SET in rtl. */ | |
5493 | REG_N_SETS (regno)++; | |
5494 | } | |
5495 | } | |
5496 | ||
d7429b6a RK |
5497 | /* X is a MEM found in INSN. See if we can convert it into an auto-increment |
5498 | reference. */ | |
5499 | ||
5500 | static void | |
62828c00 RH |
5501 | find_auto_inc (pbi, x, insn) |
5502 | struct propagate_block_info *pbi; | |
d7429b6a RK |
5503 | rtx x; |
5504 | rtx insn; | |
5505 | { | |
5506 | rtx addr = XEXP (x, 0); | |
e658434c | 5507 | HOST_WIDE_INT offset = 0; |
4b983fdc RH |
5508 | rtx set, y, incr, inc_val; |
5509 | int regno; | |
5510 | int size = GET_MODE_SIZE (GET_MODE (x)); | |
5511 | ||
5512 | if (GET_CODE (insn) == JUMP_INSN) | |
5513 | return; | |
d7429b6a RK |
5514 | |
5515 | /* Here we detect use of an index register which might be good for | |
5516 | postincrement, postdecrement, preincrement, or predecrement. */ | |
5517 | ||
5518 | if (GET_CODE (addr) == PLUS && GET_CODE (XEXP (addr, 1)) == CONST_INT) | |
5519 | offset = INTVAL (XEXP (addr, 1)), addr = XEXP (addr, 0); | |
5520 | ||
4b983fdc RH |
5521 | if (GET_CODE (addr) != REG) |
5522 | return; | |
d7429b6a | 5523 | |
4b983fdc | 5524 | regno = REGNO (addr); |
7280c2a4 | 5525 | |
4b983fdc RH |
5526 | /* Is the next use an increment that might make auto-increment? */ |
5527 | incr = pbi->reg_next_use[regno]; | |
5528 | if (incr == 0 || BLOCK_NUM (incr) != BLOCK_NUM (insn)) | |
5529 | return; | |
5530 | set = single_set (incr); | |
5531 | if (set == 0 || GET_CODE (set) != SET) | |
5532 | return; | |
5533 | y = SET_SRC (set); | |
7280c2a4 | 5534 | |
4b983fdc RH |
5535 | if (GET_CODE (y) != PLUS) |
5536 | return; | |
7280c2a4 | 5537 | |
66ed03f8 | 5538 | if (REG_P (XEXP (y, 0)) && REGNO (XEXP (y, 0)) == REGNO (addr)) |
4b983fdc | 5539 | inc_val = XEXP (y, 1); |
66ed03f8 | 5540 | else if (REG_P (XEXP (y, 1)) && REGNO (XEXP (y, 1)) == REGNO (addr)) |
4b983fdc RH |
5541 | inc_val = XEXP (y, 0); |
5542 | else | |
66ed03f8 | 5543 | return; |
d7429b6a | 5544 | |
4b983fdc RH |
5545 | if (GET_CODE (inc_val) == CONST_INT) |
5546 | { | |
5547 | if (HAVE_POST_INCREMENT | |
5548 | && (INTVAL (inc_val) == size && offset == 0)) | |
5549 | attempt_auto_inc (pbi, gen_rtx_POST_INC (Pmode, addr), insn, x, | |
5550 | incr, addr); | |
5551 | else if (HAVE_POST_DECREMENT | |
c9bacfdb | 5552 | && (INTVAL (inc_val) == -size && offset == 0)) |
4b983fdc RH |
5553 | attempt_auto_inc (pbi, gen_rtx_POST_DEC (Pmode, addr), insn, x, |
5554 | incr, addr); | |
5555 | else if (HAVE_PRE_INCREMENT | |
5556 | && (INTVAL (inc_val) == size && offset == size)) | |
5557 | attempt_auto_inc (pbi, gen_rtx_PRE_INC (Pmode, addr), insn, x, | |
5558 | incr, addr); | |
5559 | else if (HAVE_PRE_DECREMENT | |
c9bacfdb | 5560 | && (INTVAL (inc_val) == -size && offset == -size)) |
4b983fdc RH |
5561 | attempt_auto_inc (pbi, gen_rtx_PRE_DEC (Pmode, addr), insn, x, |
5562 | incr, addr); | |
5563 | else if (HAVE_POST_MODIFY_DISP && offset == 0) | |
5564 | attempt_auto_inc (pbi, gen_rtx_POST_MODIFY (Pmode, addr, | |
5565 | gen_rtx_PLUS (Pmode, | |
5566 | addr, | |
5567 | inc_val)), | |
5568 | insn, x, incr, addr); | |
5569 | } | |
5570 | else if (GET_CODE (inc_val) == REG | |
5571 | && ! reg_set_between_p (inc_val, PREV_INSN (insn), | |
5572 | NEXT_INSN (incr))) | |
7280c2a4 | 5573 | |
4b983fdc RH |
5574 | { |
5575 | if (HAVE_POST_MODIFY_REG && offset == 0) | |
5576 | attempt_auto_inc (pbi, gen_rtx_POST_MODIFY (Pmode, addr, | |
5577 | gen_rtx_PLUS (Pmode, | |
5578 | addr, | |
5579 | inc_val)), | |
5580 | insn, x, incr, addr); | |
d7429b6a RK |
5581 | } |
5582 | } | |
4b983fdc | 5583 | |
d7429b6a RK |
5584 | #endif /* AUTO_INC_DEC */ |
5585 | \f | |
62828c00 | 5586 | static void |
8e3f9094 | 5587 | mark_used_reg (pbi, reg, cond, insn) |
62828c00 | 5588 | struct propagate_block_info *pbi; |
62828c00 RH |
5589 | rtx reg; |
5590 | rtx cond ATTRIBUTE_UNUSED; | |
5591 | rtx insn; | |
5592 | { | |
5593 | int regno = REGNO (reg); | |
5594 | int some_was_live = REGNO_REG_SET_P (pbi->reg_live, regno); | |
5595 | int some_was_dead = ! some_was_live; | |
9785c68d RH |
5596 | int some_not_set; |
5597 | int n; | |
62828c00 RH |
5598 | |
5599 | /* A hard reg in a wide mode may really be multiple registers. | |
5600 | If so, mark all of them just like the first. */ | |
5601 | if (regno < FIRST_PSEUDO_REGISTER) | |
5602 | { | |
9785c68d | 5603 | n = HARD_REGNO_NREGS (regno, GET_MODE (reg)); |
62828c00 RH |
5604 | while (--n > 0) |
5605 | { | |
9785c68d | 5606 | int needed_regno = REGNO_REG_SET_P (pbi->reg_live, regno + n); |
62828c00 RH |
5607 | some_was_live |= needed_regno; |
5608 | some_was_dead |= ! needed_regno; | |
5609 | } | |
5610 | } | |
5611 | ||
5612 | if (pbi->flags & (PROP_LOG_LINKS | PROP_AUTOINC)) | |
5613 | { | |
5614 | /* Record where each reg is used, so when the reg is set we know | |
5615 | the next insn that uses it. */ | |
5616 | pbi->reg_next_use[regno] = insn; | |
5617 | } | |
5618 | ||
5619 | if (pbi->flags & PROP_REG_INFO) | |
5620 | { | |
5621 | if (regno < FIRST_PSEUDO_REGISTER) | |
5622 | { | |
5623 | /* If this is a register we are going to try to eliminate, | |
5624 | don't mark it live here. If we are successful in | |
5625 | eliminating it, it need not be live unless it is used for | |
5626 | pseudos, in which case it will have been set live when it | |
5627 | was allocated to the pseudos. If the register will not | |
5628 | be eliminated, reload will set it live at that point. | |
5629 | ||
5630 | Otherwise, record that this function uses this register. */ | |
b2433fcd RH |
5631 | /* ??? The PPC backend tries to "eliminate" on the pic |
5632 | register to itself. This should be fixed. In the mean | |
5633 | time, hack around it. */ | |
d7429b6a | 5634 | |
b2433fcd RH |
5635 | if (! (TEST_HARD_REG_BIT (elim_reg_set, regno) |
5636 | && (regno == FRAME_POINTER_REGNUM | |
5637 | || regno == ARG_POINTER_REGNUM))) | |
62828c00 RH |
5638 | { |
5639 | int n = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
62828c00 RH |
5640 | do |
5641 | regs_ever_live[regno + --n] = 1; | |
5642 | while (n > 0); | |
5643 | } | |
5644 | } | |
5645 | else | |
5646 | { | |
5647 | /* Keep track of which basic block each reg appears in. */ | |
5648 | ||
5649 | register int blocknum = pbi->bb->index; | |
5650 | if (REG_BASIC_BLOCK (regno) == REG_BLOCK_UNKNOWN) | |
5651 | REG_BASIC_BLOCK (regno) = blocknum; | |
5652 | else if (REG_BASIC_BLOCK (regno) != blocknum) | |
5653 | REG_BASIC_BLOCK (regno) = REG_BLOCK_GLOBAL; | |
5654 | ||
5655 | /* Count (weighted) number of uses of each reg. */ | |
ebfe71a8 NC |
5656 | REG_N_REFS (regno) += (optimize_size ? 1 |
5657 | : pbi->bb->loop_depth + 1); | |
62828c00 RH |
5658 | } |
5659 | } | |
d7429b6a | 5660 | |
9785c68d RH |
5661 | /* Find out if any of the register was set this insn. */ |
5662 | some_not_set = ! REGNO_REG_SET_P (pbi->new_set, regno); | |
5663 | if (regno < FIRST_PSEUDO_REGISTER) | |
5664 | { | |
5665 | n = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
5666 | while (--n > 0) | |
5667 | some_not_set |= ! REGNO_REG_SET_P (pbi->new_set, regno + n); | |
5668 | } | |
5669 | ||
62828c00 RH |
5670 | /* Record and count the insns in which a reg dies. If it is used in |
5671 | this insn and was dead below the insn then it dies in this insn. | |
5672 | If it was set in this insn, we do not make a REG_DEAD note; | |
9785c68d RH |
5673 | likewise if we already made such a note. */ |
5674 | if ((pbi->flags & (PROP_DEATH_NOTES | PROP_REG_INFO)) | |
62828c00 | 5675 | && some_was_dead |
9785c68d | 5676 | && some_not_set) |
62828c00 | 5677 | { |
62828c00 RH |
5678 | /* Check for the case where the register dying partially |
5679 | overlaps the register set by this insn. */ | |
5680 | if (regno < FIRST_PSEUDO_REGISTER | |
5681 | && HARD_REGNO_NREGS (regno, GET_MODE (reg)) > 1) | |
5682 | { | |
5683 | n = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
5684 | while (--n >= 0) | |
9785c68d | 5685 | some_was_live |= REGNO_REG_SET_P (pbi->new_set, regno + n); |
62828c00 RH |
5686 | } |
5687 | ||
5688 | /* If none of the words in X is needed, make a REG_DEAD note. | |
5689 | Otherwise, we must make partial REG_DEAD notes. */ | |
5690 | if (! some_was_live) | |
5691 | { | |
9785c68d RH |
5692 | if ((pbi->flags & PROP_DEATH_NOTES) |
5693 | && ! find_regno_note (insn, REG_DEAD, regno)) | |
5694 | REG_NOTES (insn) | |
5695 | = alloc_EXPR_LIST (REG_DEAD, reg, REG_NOTES (insn)); | |
5696 | ||
5697 | if (pbi->flags & PROP_REG_INFO) | |
5698 | REG_N_DEATHS (regno)++; | |
62828c00 RH |
5699 | } |
5700 | else | |
5701 | { | |
5702 | /* Don't make a REG_DEAD note for a part of a register | |
5703 | that is set in the insn. */ | |
5704 | ||
5705 | n = regno + HARD_REGNO_NREGS (regno, GET_MODE (reg)) - 1; | |
5706 | for (; n >= regno; n--) | |
9785c68d | 5707 | if (! REGNO_REG_SET_P (pbi->reg_live, n) |
62828c00 RH |
5708 | && ! dead_or_set_regno_p (insn, n)) |
5709 | REG_NOTES (insn) | |
5710 | = alloc_EXPR_LIST (REG_DEAD, | |
5711 | gen_rtx_REG (reg_raw_mode[n], n), | |
5712 | REG_NOTES (insn)); | |
5713 | } | |
5714 | } | |
9785c68d RH |
5715 | |
5716 | SET_REGNO_REG_SET (pbi->reg_live, regno); | |
5717 | if (regno < FIRST_PSEUDO_REGISTER) | |
5718 | { | |
5719 | n = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
5720 | while (--n > 0) | |
5721 | SET_REGNO_REG_SET (pbi->reg_live, regno + n); | |
5722 | } | |
11ae508b RH |
5723 | |
5724 | #ifdef HAVE_conditional_execution | |
5725 | /* If this is a conditional use, record that fact. If it is later | |
5726 | conditionally set, we'll know to kill the register. */ | |
5727 | if (cond != NULL_RTX) | |
5728 | { | |
5729 | splay_tree_node node; | |
5730 | struct reg_cond_life_info *rcli; | |
5731 | rtx ncond; | |
5732 | ||
5733 | if (some_was_live) | |
5734 | { | |
5735 | node = splay_tree_lookup (pbi->reg_cond_dead, regno); | |
5736 | if (node == NULL) | |
5737 | { | |
5738 | /* The register was unconditionally live previously. | |
5739 | No need to do anything. */ | |
5740 | } | |
5741 | else | |
5742 | { | |
c9bacfdb | 5743 | /* The register was conditionally live previously. |
11ae508b RH |
5744 | Subtract the new life cond from the old death cond. */ |
5745 | rcli = (struct reg_cond_life_info *) node->value; | |
5746 | ncond = rcli->condition; | |
288c2c9e | 5747 | ncond = and_reg_cond (ncond, not_reg_cond (cond), 1); |
11ae508b RH |
5748 | |
5749 | /* If the register is now unconditionally live, remove the | |
5750 | entry in the splay_tree. */ | |
5751 | if (ncond == const0_rtx) | |
685af3af | 5752 | splay_tree_remove (pbi->reg_cond_dead, regno); |
11ae508b | 5753 | else |
7791b7f9 RH |
5754 | { |
5755 | rcli->condition = ncond; | |
5756 | SET_REGNO_REG_SET (pbi->reg_cond_reg, REGNO (XEXP (cond, 0))); | |
5757 | } | |
11ae508b RH |
5758 | } |
5759 | } | |
5760 | else | |
5761 | { | |
5762 | /* The register was not previously live at all. Record | |
5763 | the condition under which it is still dead. */ | |
5764 | rcli = (struct reg_cond_life_info *) xmalloc (sizeof (*rcli)); | |
5765 | rcli->condition = not_reg_cond (cond); | |
685af3af JW |
5766 | rcli->stores = const0_rtx; |
5767 | rcli->orig_condition = const0_rtx; | |
11ae508b RH |
5768 | splay_tree_insert (pbi->reg_cond_dead, regno, |
5769 | (splay_tree_value) rcli); | |
7791b7f9 RH |
5770 | |
5771 | SET_REGNO_REG_SET (pbi->reg_cond_reg, REGNO (XEXP (cond, 0))); | |
11ae508b RH |
5772 | } |
5773 | } | |
6a3dbe65 RE |
5774 | else if (some_was_live) |
5775 | { | |
5776 | splay_tree_node node; | |
6a3dbe65 RE |
5777 | |
5778 | node = splay_tree_lookup (pbi->reg_cond_dead, regno); | |
5779 | if (node != NULL) | |
5780 | { | |
5781 | /* The register was conditionally live previously, but is now | |
5782 | unconditionally so. Remove it from the conditionally dead | |
5783 | list, so that a conditional set won't cause us to think | |
5784 | it dead. */ | |
6a3dbe65 RE |
5785 | splay_tree_remove (pbi->reg_cond_dead, regno); |
5786 | } | |
5787 | } | |
5788 | ||
11ae508b | 5789 | #endif |
62828c00 RH |
5790 | } |
5791 | ||
5792 | /* Scan expression X and store a 1-bit in NEW_LIVE for each reg it uses. | |
5793 | This is done assuming the registers needed from X are those that | |
5794 | have 1-bits in PBI->REG_LIVE. | |
5795 | ||
5796 | INSN is the containing instruction. If INSN is dead, this function | |
5797 | is not called. */ | |
d7429b6a RK |
5798 | |
5799 | static void | |
8e3f9094 | 5800 | mark_used_regs (pbi, x, cond, insn) |
62828c00 | 5801 | struct propagate_block_info *pbi; |
62828c00 | 5802 | rtx x, cond, insn; |
d7429b6a RK |
5803 | { |
5804 | register RTX_CODE code; | |
5805 | register int regno; | |
62828c00 | 5806 | int flags = pbi->flags; |
d7429b6a RK |
5807 | |
5808 | retry: | |
5809 | code = GET_CODE (x); | |
5810 | switch (code) | |
5811 | { | |
5812 | case LABEL_REF: | |
5813 | case SYMBOL_REF: | |
5814 | case CONST_INT: | |
5815 | case CONST: | |
5816 | case CONST_DOUBLE: | |
5817 | case PC: | |
d7429b6a RK |
5818 | case ADDR_VEC: |
5819 | case ADDR_DIFF_VEC: | |
d7429b6a RK |
5820 | return; |
5821 | ||
5822 | #ifdef HAVE_cc0 | |
5823 | case CC0: | |
62828c00 | 5824 | pbi->cc0_live = 1; |
d7429b6a RK |
5825 | return; |
5826 | #endif | |
5827 | ||
2f1553a4 RK |
5828 | case CLOBBER: |
5829 | /* If we are clobbering a MEM, mark any registers inside the address | |
5830 | as being used. */ | |
5831 | if (GET_CODE (XEXP (x, 0)) == MEM) | |
8e3f9094 | 5832 | mark_used_regs (pbi, XEXP (XEXP (x, 0), 0), cond, insn); |
2f1553a4 RK |
5833 | return; |
5834 | ||
d7429b6a | 5835 | case MEM: |
c9bacfdb | 5836 | /* Don't bother watching stores to mems if this is not the |
d3a923ee | 5837 | final pass. We'll not be deleting dead stores this round. */ |
b2262f4a | 5838 | if (optimize && (flags & PROP_SCAN_DEAD_CODE)) |
db3a887b | 5839 | { |
c9bacfdb | 5840 | /* Invalidate the data for the last MEM stored, but only if MEM is |
d3a923ee | 5841 | something that can be stored into. */ |
c9bacfdb | 5842 | if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF |
d3a923ee | 5843 | && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0))) |
c9bacfdb KH |
5844 | /* Needn't clear the memory set list. */ |
5845 | ; | |
5846 | else | |
db3a887b | 5847 | { |
62828c00 | 5848 | rtx temp = pbi->mem_set_list; |
d3a923ee | 5849 | rtx prev = NULL_RTX; |
ff666313 | 5850 | rtx next; |
d3a923ee RH |
5851 | |
5852 | while (temp) | |
db3a887b | 5853 | { |
ff666313 | 5854 | next = XEXP (temp, 1); |
d3a923ee RH |
5855 | if (anti_dependence (XEXP (temp, 0), x)) |
5856 | { | |
5857 | /* Splice temp out of the list. */ | |
5858 | if (prev) | |
ff666313 | 5859 | XEXP (prev, 1) = next; |
d3a923ee | 5860 | else |
62828c00 | 5861 | pbi->mem_set_list = next; |
ff666313 | 5862 | free_EXPR_LIST_node (temp); |
0875baa0 | 5863 | pbi->mem_set_list_len--; |
d3a923ee | 5864 | } |
db3a887b | 5865 | else |
d3a923ee | 5866 | prev = temp; |
ff666313 | 5867 | temp = next; |
db3a887b | 5868 | } |
db3a887b | 5869 | } |
d7429b6a | 5870 | |
d3a923ee RH |
5871 | /* If the memory reference had embedded side effects (autoincrement |
5872 | address modes. Then we may need to kill some entries on the | |
5873 | memory set list. */ | |
5874 | if (insn) | |
62828c00 | 5875 | invalidate_mems_from_autoinc (pbi, insn); |
d3a923ee | 5876 | } |
15e088b2 | 5877 | |
d7429b6a | 5878 | #ifdef AUTO_INC_DEC |
61f286b6 | 5879 | if (flags & PROP_AUTOINC) |
62828c00 | 5880 | find_auto_inc (pbi, x, insn); |
d7429b6a RK |
5881 | #endif |
5882 | break; | |
5883 | ||
80f8f04a | 5884 | case SUBREG: |
02188693 | 5885 | #ifdef CLASS_CANNOT_CHANGE_MODE |
80f8f04a RK |
5886 | if (GET_CODE (SUBREG_REG (x)) == REG |
5887 | && REGNO (SUBREG_REG (x)) >= FIRST_PSEUDO_REGISTER | |
02188693 RH |
5888 | && CLASS_CANNOT_CHANGE_MODE_P (GET_MODE (x), |
5889 | GET_MODE (SUBREG_REG (x)))) | |
5890 | REG_CHANGES_MODE (REGNO (SUBREG_REG (x))) = 1; | |
5891 | #endif | |
80f8f04a RK |
5892 | |
5893 | /* While we're here, optimize this case. */ | |
5894 | x = SUBREG_REG (x); | |
ce79abf3 | 5895 | if (GET_CODE (x) != REG) |
62828c00 | 5896 | goto retry; |
c9bacfdb | 5897 | /* Fall through. */ |
80f8f04a | 5898 | |
d7429b6a | 5899 | case REG: |
62828c00 | 5900 | /* See a register other than being set => mark it as needed. */ |
8e3f9094 | 5901 | mark_used_reg (pbi, x, cond, insn); |
d7429b6a RK |
5902 | return; |
5903 | ||
5904 | case SET: | |
5905 | { | |
5906 | register rtx testreg = SET_DEST (x); | |
5907 | int mark_dest = 0; | |
5908 | ||
5909 | /* If storing into MEM, don't show it as being used. But do | |
5910 | show the address as being used. */ | |
5911 | if (GET_CODE (testreg) == MEM) | |
5912 | { | |
5913 | #ifdef AUTO_INC_DEC | |
61f286b6 | 5914 | if (flags & PROP_AUTOINC) |
62828c00 | 5915 | find_auto_inc (pbi, testreg, insn); |
d7429b6a | 5916 | #endif |
8e3f9094 RH |
5917 | mark_used_regs (pbi, XEXP (testreg, 0), cond, insn); |
5918 | mark_used_regs (pbi, SET_SRC (x), cond, insn); | |
d7429b6a RK |
5919 | return; |
5920 | } | |
c9bacfdb | 5921 | |
d7429b6a RK |
5922 | /* Storing in STRICT_LOW_PART is like storing in a reg |
5923 | in that this SET might be dead, so ignore it in TESTREG. | |
5924 | but in some other ways it is like using the reg. | |
5925 | ||
5926 | Storing in a SUBREG or a bit field is like storing the entire | |
5927 | register in that if the register's value is not used | |
5928 | then this SET is not needed. */ | |
5929 | while (GET_CODE (testreg) == STRICT_LOW_PART | |
5930 | || GET_CODE (testreg) == ZERO_EXTRACT | |
5931 | || GET_CODE (testreg) == SIGN_EXTRACT | |
5932 | || GET_CODE (testreg) == SUBREG) | |
5933 | { | |
02188693 | 5934 | #ifdef CLASS_CANNOT_CHANGE_MODE |
88285acf RK |
5935 | if (GET_CODE (testreg) == SUBREG |
5936 | && GET_CODE (SUBREG_REG (testreg)) == REG | |
5937 | && REGNO (SUBREG_REG (testreg)) >= FIRST_PSEUDO_REGISTER | |
02188693 RH |
5938 | && CLASS_CANNOT_CHANGE_MODE_P (GET_MODE (SUBREG_REG (testreg)), |
5939 | GET_MODE (testreg))) | |
5940 | REG_CHANGES_MODE (REGNO (SUBREG_REG (testreg))) = 1; | |
5941 | #endif | |
88285acf | 5942 | |
d7429b6a RK |
5943 | /* Modifying a single register in an alternate mode |
5944 | does not use any of the old value. But these other | |
5945 | ways of storing in a register do use the old value. */ | |
5946 | if (GET_CODE (testreg) == SUBREG | |
5947 | && !(REG_SIZE (SUBREG_REG (testreg)) > REG_SIZE (testreg))) | |
5948 | ; | |
5949 | else | |
5950 | mark_dest = 1; | |
5951 | ||
5952 | testreg = XEXP (testreg, 0); | |
5953 | } | |
5954 | ||
90d036a0 RK |
5955 | /* If this is a store into a register or group of registers, |
5956 | recursively scan the value being stored. */ | |
d7429b6a | 5957 | |
86465af7 DM |
5958 | if ((GET_CODE (testreg) == PARALLEL |
5959 | && GET_MODE (testreg) == BLKmode) | |
5960 | || (GET_CODE (testreg) == REG | |
62828c00 RH |
5961 | && (regno = REGNO (testreg), |
5962 | ! (regno == FRAME_POINTER_REGNUM | |
5963 | && (! reload_completed || frame_pointer_needed))) | |
73a187c1 | 5964 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
e4b8a413 JW |
5965 | && ! (regno == HARD_FRAME_POINTER_REGNUM |
5966 | && (! reload_completed || frame_pointer_needed)) | |
73a187c1 | 5967 | #endif |
d7e4fe8b | 5968 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
86465af7 | 5969 | && ! (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) |
d7e4fe8b | 5970 | #endif |
86465af7 | 5971 | )) |
d7429b6a | 5972 | { |
d7429b6a | 5973 | if (mark_dest) |
8e3f9094 RH |
5974 | mark_used_regs (pbi, SET_DEST (x), cond, insn); |
5975 | mark_used_regs (pbi, SET_SRC (x), cond, insn); | |
d7429b6a RK |
5976 | return; |
5977 | } | |
5978 | } | |
5979 | break; | |
5980 | ||
40b5a77c JL |
5981 | case ASM_OPERANDS: |
5982 | case UNSPEC_VOLATILE: | |
5983 | case TRAP_IF: | |
5984 | case ASM_INPUT: | |
5985 | { | |
5986 | /* Traditional and volatile asm instructions must be considered to use | |
5987 | and clobber all hard registers, all pseudo-registers and all of | |
5988 | memory. So must TRAP_IF and UNSPEC_VOLATILE operations. | |
5989 | ||
5990 | Consider for instance a volatile asm that changes the fpu rounding | |
5991 | mode. An insn should not be moved across this even if it only uses | |
c9bacfdb | 5992 | pseudo-regs because it might give an incorrectly rounded result. |
40b5a77c JL |
5993 | |
5994 | ?!? Unfortunately, marking all hard registers as live causes massive | |
5995 | problems for the register allocator and marking all pseudos as live | |
5996 | creates mountains of uninitialized variable warnings. | |
5997 | ||
5998 | So for now, just clear the memory set list and mark any regs | |
5999 | we can find in ASM_OPERANDS as used. */ | |
6000 | if (code != ASM_OPERANDS || MEM_VOLATILE_P (x)) | |
0875baa0 RH |
6001 | { |
6002 | free_EXPR_LIST_list (&pbi->mem_set_list); | |
6003 | pbi->mem_set_list_len = 0; | |
6004 | } | |
40b5a77c | 6005 | |
c9bacfdb | 6006 | /* For all ASM_OPERANDS, we must traverse the vector of input operands. |
40b5a77c JL |
6007 | We can not just fall through here since then we would be confused |
6008 | by the ASM_INPUT rtx inside ASM_OPERANDS, which do not indicate | |
6009 | traditional asms unlike their normal usage. */ | |
6010 | if (code == ASM_OPERANDS) | |
6011 | { | |
6012 | int j; | |
6013 | ||
6014 | for (j = 0; j < ASM_OPERANDS_INPUT_LENGTH (x); j++) | |
8e3f9094 | 6015 | mark_used_regs (pbi, ASM_OPERANDS_INPUT (x, j), cond, insn); |
40b5a77c JL |
6016 | } |
6017 | break; | |
6018 | } | |
6019 | ||
62828c00 RH |
6020 | case COND_EXEC: |
6021 | if (cond != NULL_RTX) | |
6022 | abort (); | |
6023 | ||
8e3f9094 | 6024 | mark_used_regs (pbi, COND_EXEC_TEST (x), NULL_RTX, insn); |
62828c00 RH |
6025 | |
6026 | cond = COND_EXEC_TEST (x); | |
6027 | x = COND_EXEC_CODE (x); | |
6028 | goto retry; | |
6029 | ||
4e872036 AS |
6030 | case PHI: |
6031 | /* We _do_not_ want to scan operands of phi nodes. Operands of | |
6032 | a phi function are evaluated only when control reaches this | |
6033 | block along a particular edge. Therefore, regs that appear | |
6034 | as arguments to phi should not be added to the global live at | |
6035 | start. */ | |
6036 | return; | |
40b5a77c | 6037 | |
e9a25f70 JL |
6038 | default: |
6039 | break; | |
d7429b6a RK |
6040 | } |
6041 | ||
6042 | /* Recursively scan the operands of this expression. */ | |
6043 | ||
6044 | { | |
6f7d635c | 6045 | register const char *fmt = GET_RTX_FORMAT (code); |
d7429b6a | 6046 | register int i; |
c9bacfdb | 6047 | |
d7429b6a RK |
6048 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) |
6049 | { | |
6050 | if (fmt[i] == 'e') | |
6051 | { | |
6052 | /* Tail recursive case: save a function call level. */ | |
6053 | if (i == 0) | |
6054 | { | |
6055 | x = XEXP (x, 0); | |
6056 | goto retry; | |
6057 | } | |
8e3f9094 | 6058 | mark_used_regs (pbi, XEXP (x, i), cond, insn); |
d7429b6a RK |
6059 | } |
6060 | else if (fmt[i] == 'E') | |
6061 | { | |
6062 | register int j; | |
6063 | for (j = 0; j < XVECLEN (x, i); j++) | |
8e3f9094 | 6064 | mark_used_regs (pbi, XVECEXP (x, i, j), cond, insn); |
d7429b6a RK |
6065 | } |
6066 | } | |
6067 | } | |
6068 | } | |
6069 | \f | |
6070 | #ifdef AUTO_INC_DEC | |
6071 | ||
6072 | static int | |
62828c00 RH |
6073 | try_pre_increment_1 (pbi, insn) |
6074 | struct propagate_block_info *pbi; | |
d7429b6a RK |
6075 | rtx insn; |
6076 | { | |
6077 | /* Find the next use of this reg. If in same basic block, | |
6078 | make it do pre-increment or pre-decrement if appropriate. */ | |
956d6950 | 6079 | rtx x = single_set (insn); |
5f4f0e22 | 6080 | HOST_WIDE_INT amount = ((GET_CODE (SET_SRC (x)) == PLUS ? 1 : -1) |
c9bacfdb | 6081 | * INTVAL (XEXP (SET_SRC (x), 1))); |
d7429b6a | 6082 | int regno = REGNO (SET_DEST (x)); |
62828c00 | 6083 | rtx y = pbi->reg_next_use[regno]; |
d7429b6a | 6084 | if (y != 0 |
24948ccc | 6085 | && SET_DEST (x) != stack_pointer_rtx |
d7429b6a | 6086 | && BLOCK_NUM (y) == BLOCK_NUM (insn) |
89861c38 | 6087 | /* Don't do this if the reg dies, or gets set in y; a standard addressing |
0f41302f | 6088 | mode would be better. */ |
89861c38 | 6089 | && ! dead_or_set_p (y, SET_DEST (x)) |
956d6950 | 6090 | && try_pre_increment (y, SET_DEST (x), amount)) |
d7429b6a | 6091 | { |
1288c070 RH |
6092 | /* We have found a suitable auto-increment and already changed |
6093 | insn Y to do it. So flush this increment instruction. */ | |
6094 | propagate_block_delete_insn (pbi->bb, insn); | |
6095 | ||
6096 | /* Count a reference to this reg for the increment insn we are | |
6097 | deleting. When a reg is incremented, spilling it is worse, | |
6098 | so we want to make that less likely. */ | |
d7429b6a RK |
6099 | if (regno >= FIRST_PSEUDO_REGISTER) |
6100 | { | |
ebfe71a8 NC |
6101 | REG_N_REFS (regno) += (optimize_size ? 1 |
6102 | : pbi->bb->loop_depth + 1); | |
b1f21e0a | 6103 | REG_N_SETS (regno)++; |
d7429b6a | 6104 | } |
1288c070 RH |
6105 | |
6106 | /* Flush any remembered memories depending on the value of | |
6107 | the incremented register. */ | |
6108 | invalidate_mems_from_set (pbi, SET_DEST (x)); | |
6109 | ||
d7429b6a RK |
6110 | return 1; |
6111 | } | |
6112 | return 0; | |
6113 | } | |
6114 | ||
6115 | /* Try to change INSN so that it does pre-increment or pre-decrement | |
6116 | addressing on register REG in order to add AMOUNT to REG. | |
6117 | AMOUNT is negative for pre-decrement. | |
6118 | Returns 1 if the change could be made. | |
6119 | This checks all about the validity of the result of modifying INSN. */ | |
6120 | ||
6121 | static int | |
6122 | try_pre_increment (insn, reg, amount) | |
6123 | rtx insn, reg; | |
5f4f0e22 | 6124 | HOST_WIDE_INT amount; |
d7429b6a RK |
6125 | { |
6126 | register rtx use; | |
6127 | ||
6128 | /* Nonzero if we can try to make a pre-increment or pre-decrement. | |
6129 | For example, addl $4,r1; movl (r1),... can become movl +(r1),... */ | |
6130 | int pre_ok = 0; | |
6131 | /* Nonzero if we can try to make a post-increment or post-decrement. | |
6132 | For example, addl $4,r1; movl -4(r1),... can become movl (r1)+,... | |
6133 | It is possible for both PRE_OK and POST_OK to be nonzero if the machine | |
6134 | supports both pre-inc and post-inc, or both pre-dec and post-dec. */ | |
6135 | int post_ok = 0; | |
6136 | ||
6137 | /* Nonzero if the opportunity actually requires post-inc or post-dec. */ | |
6138 | int do_post = 0; | |
6139 | ||
6140 | /* From the sign of increment, see which possibilities are conceivable | |
6141 | on this target machine. */ | |
940da324 | 6142 | if (HAVE_PRE_INCREMENT && amount > 0) |
d7429b6a | 6143 | pre_ok = 1; |
940da324 | 6144 | if (HAVE_POST_INCREMENT && amount > 0) |
d7429b6a | 6145 | post_ok = 1; |
d7429b6a | 6146 | |
940da324 | 6147 | if (HAVE_PRE_DECREMENT && amount < 0) |
d7429b6a | 6148 | pre_ok = 1; |
940da324 | 6149 | if (HAVE_POST_DECREMENT && amount < 0) |
d7429b6a | 6150 | post_ok = 1; |
d7429b6a RK |
6151 | |
6152 | if (! (pre_ok || post_ok)) | |
6153 | return 0; | |
6154 | ||
6155 | /* It is not safe to add a side effect to a jump insn | |
6156 | because if the incremented register is spilled and must be reloaded | |
6157 | there would be no way to store the incremented value back in memory. */ | |
6158 | ||
6159 | if (GET_CODE (insn) == JUMP_INSN) | |
6160 | return 0; | |
6161 | ||
6162 | use = 0; | |
6163 | if (pre_ok) | |
6164 | use = find_use_as_address (PATTERN (insn), reg, 0); | |
6165 | if (post_ok && (use == 0 || use == (rtx) 1)) | |
6166 | { | |
6167 | use = find_use_as_address (PATTERN (insn), reg, -amount); | |
6168 | do_post = 1; | |
6169 | } | |
6170 | ||
6171 | if (use == 0 || use == (rtx) 1) | |
6172 | return 0; | |
6173 | ||
6174 | if (GET_MODE_SIZE (GET_MODE (use)) != (amount > 0 ? amount : - amount)) | |
6175 | return 0; | |
6176 | ||
a0fbc3a9 SC |
6177 | /* See if this combination of instruction and addressing mode exists. */ |
6178 | if (! validate_change (insn, &XEXP (use, 0), | |
38a448ca RH |
6179 | gen_rtx_fmt_e (amount > 0 |
6180 | ? (do_post ? POST_INC : PRE_INC) | |
6181 | : (do_post ? POST_DEC : PRE_DEC), | |
6182 | Pmode, reg), 0)) | |
a0fbc3a9 | 6183 | return 0; |
d7429b6a RK |
6184 | |
6185 | /* Record that this insn now has an implicit side effect on X. */ | |
d3a923ee | 6186 | REG_NOTES (insn) = alloc_EXPR_LIST (REG_INC, reg, REG_NOTES (insn)); |
d7429b6a RK |
6187 | return 1; |
6188 | } | |
6189 | ||
6190 | #endif /* AUTO_INC_DEC */ | |
6191 | \f | |
6192 | /* Find the place in the rtx X where REG is used as a memory address. | |
6193 | Return the MEM rtx that so uses it. | |
6194 | If PLUSCONST is nonzero, search instead for a memory address equivalent to | |
6195 | (plus REG (const_int PLUSCONST)). | |
6196 | ||
6197 | If such an address does not appear, return 0. | |
6198 | If REG appears more than once, or is used other than in such an address, | |
6199 | return (rtx)1. */ | |
6200 | ||
8c660648 | 6201 | rtx |
d7429b6a RK |
6202 | find_use_as_address (x, reg, plusconst) |
6203 | register rtx x; | |
6204 | rtx reg; | |
e658434c | 6205 | HOST_WIDE_INT plusconst; |
d7429b6a RK |
6206 | { |
6207 | enum rtx_code code = GET_CODE (x); | |
6f7d635c | 6208 | const char *fmt = GET_RTX_FORMAT (code); |
d7429b6a RK |
6209 | register int i; |
6210 | register rtx value = 0; | |
6211 | register rtx tem; | |
6212 | ||
6213 | if (code == MEM && XEXP (x, 0) == reg && plusconst == 0) | |
6214 | return x; | |
6215 | ||
6216 | if (code == MEM && GET_CODE (XEXP (x, 0)) == PLUS | |
6217 | && XEXP (XEXP (x, 0), 0) == reg | |
6218 | && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT | |
6219 | && INTVAL (XEXP (XEXP (x, 0), 1)) == plusconst) | |
6220 | return x; | |
6221 | ||
6222 | if (code == SIGN_EXTRACT || code == ZERO_EXTRACT) | |
6223 | { | |
6224 | /* If REG occurs inside a MEM used in a bit-field reference, | |
6225 | that is unacceptable. */ | |
6226 | if (find_use_as_address (XEXP (x, 0), reg, 0) != 0) | |
6fa5c106 | 6227 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
6228 | } |
6229 | ||
6230 | if (x == reg) | |
6fa5c106 | 6231 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
6232 | |
6233 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
6234 | { | |
6235 | if (fmt[i] == 'e') | |
6236 | { | |
6237 | tem = find_use_as_address (XEXP (x, i), reg, plusconst); | |
6238 | if (value == 0) | |
6239 | value = tem; | |
6240 | else if (tem != 0) | |
6fa5c106 | 6241 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a | 6242 | } |
d4757e6a | 6243 | else if (fmt[i] == 'E') |
d7429b6a RK |
6244 | { |
6245 | register int j; | |
6246 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
6247 | { | |
6248 | tem = find_use_as_address (XVECEXP (x, i, j), reg, plusconst); | |
6249 | if (value == 0) | |
6250 | value = tem; | |
6251 | else if (tem != 0) | |
6fa5c106 | 6252 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
6253 | } |
6254 | } | |
6255 | } | |
6256 | ||
6257 | return value; | |
6258 | } | |
6259 | \f | |
6260 | /* Write information about registers and basic blocks into FILE. | |
6261 | This is part of making a debugging dump. */ | |
6262 | ||
b7ba4d8d ZW |
6263 | void |
6264 | dump_regset (r, outf) | |
6265 | regset r; | |
6266 | FILE *outf; | |
6267 | { | |
6268 | int i; | |
6269 | if (r == NULL) | |
6270 | { | |
6271 | fputs (" (nil)", outf); | |
6272 | return; | |
6273 | } | |
6274 | ||
6275 | EXECUTE_IF_SET_IN_REG_SET (r, 0, i, | |
6276 | { | |
6277 | fprintf (outf, " %d", i); | |
6278 | if (i < FIRST_PSEUDO_REGISTER) | |
6279 | fprintf (outf, " [%s]", | |
6280 | reg_names[i]); | |
6281 | }); | |
6282 | } | |
6283 | ||
6284 | void | |
6285 | debug_regset (r) | |
6286 | regset r; | |
6287 | { | |
6288 | dump_regset (r, stderr); | |
6289 | putc ('\n', stderr); | |
6290 | } | |
6291 | ||
d7429b6a RK |
6292 | void |
6293 | dump_flow_info (file) | |
6294 | FILE *file; | |
6295 | { | |
6296 | register int i; | |
6f7d635c | 6297 | static const char * const reg_class_names[] = REG_CLASS_NAMES; |
d7429b6a RK |
6298 | |
6299 | fprintf (file, "%d registers.\n", max_regno); | |
d7429b6a | 6300 | for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) |
b1f21e0a | 6301 | if (REG_N_REFS (i)) |
d7429b6a | 6302 | { |
e4600702 | 6303 | enum reg_class class, altclass; |
d7429b6a | 6304 | fprintf (file, "\nRegister %d used %d times across %d insns", |
b1f21e0a MM |
6305 | i, REG_N_REFS (i), REG_LIVE_LENGTH (i)); |
6306 | if (REG_BASIC_BLOCK (i) >= 0) | |
6307 | fprintf (file, " in block %d", REG_BASIC_BLOCK (i)); | |
6fc4610b | 6308 | if (REG_N_SETS (i)) |
c9bacfdb KH |
6309 | fprintf (file, "; set %d time%s", REG_N_SETS (i), |
6310 | (REG_N_SETS (i) == 1) ? "" : "s"); | |
6fc4610b | 6311 | if (REG_USERVAR_P (regno_reg_rtx[i])) |
c9bacfdb | 6312 | fprintf (file, "; user var"); |
b1f21e0a MM |
6313 | if (REG_N_DEATHS (i) != 1) |
6314 | fprintf (file, "; dies in %d places", REG_N_DEATHS (i)); | |
6315 | if (REG_N_CALLS_CROSSED (i) == 1) | |
d7429b6a | 6316 | fprintf (file, "; crosses 1 call"); |
b1f21e0a MM |
6317 | else if (REG_N_CALLS_CROSSED (i)) |
6318 | fprintf (file, "; crosses %d calls", REG_N_CALLS_CROSSED (i)); | |
d7429b6a RK |
6319 | if (PSEUDO_REGNO_BYTES (i) != UNITS_PER_WORD) |
6320 | fprintf (file, "; %d bytes", PSEUDO_REGNO_BYTES (i)); | |
6321 | class = reg_preferred_class (i); | |
e4600702 RK |
6322 | altclass = reg_alternate_class (i); |
6323 | if (class != GENERAL_REGS || altclass != ALL_REGS) | |
d7429b6a | 6324 | { |
e4600702 RK |
6325 | if (altclass == ALL_REGS || class == ALL_REGS) |
6326 | fprintf (file, "; pref %s", reg_class_names[(int) class]); | |
6327 | else if (altclass == NO_REGS) | |
d7429b6a RK |
6328 | fprintf (file, "; %s or none", reg_class_names[(int) class]); |
6329 | else | |
e4600702 RK |
6330 | fprintf (file, "; pref %s, else %s", |
6331 | reg_class_names[(int) class], | |
6332 | reg_class_names[(int) altclass]); | |
d7429b6a | 6333 | } |
3502dc9c | 6334 | if (REG_POINTER (regno_reg_rtx[i])) |
d7429b6a RK |
6335 | fprintf (file, "; pointer"); |
6336 | fprintf (file, ".\n"); | |
6337 | } | |
e881bb1b | 6338 | |
d3a923ee | 6339 | fprintf (file, "\n%d basic blocks, %d edges.\n", n_basic_blocks, n_edges); |
e881bb1b RH |
6340 | for (i = 0; i < n_basic_blocks; i++) |
6341 | { | |
6342 | register basic_block bb = BASIC_BLOCK (i); | |
e881bb1b RH |
6343 | register edge e; |
6344 | ||
51891abe JH |
6345 | fprintf (file, "\nBasic block %d: first insn %d, last %d, loop_depth %d, count %d.\n", |
6346 | i, INSN_UID (bb->head), INSN_UID (bb->end), bb->loop_depth, bb->count); | |
e881bb1b RH |
6347 | |
6348 | fprintf (file, "Predecessors: "); | |
c9bacfdb | 6349 | for (e = bb->pred; e; e = e->pred_next) |
e881bb1b RH |
6350 | dump_edge_info (file, e, 0); |
6351 | ||
6352 | fprintf (file, "\nSuccessors: "); | |
c9bacfdb | 6353 | for (e = bb->succ; e; e = e->succ_next) |
e881bb1b RH |
6354 | dump_edge_info (file, e, 1); |
6355 | ||
6356 | fprintf (file, "\nRegisters live at start:"); | |
b7ba4d8d | 6357 | dump_regset (bb->global_live_at_start, file); |
e881bb1b RH |
6358 | |
6359 | fprintf (file, "\nRegisters live at end:"); | |
b7ba4d8d | 6360 | dump_regset (bb->global_live_at_end, file); |
e881bb1b | 6361 | |
c9bacfdb | 6362 | putc ('\n', file); |
e881bb1b RH |
6363 | } |
6364 | ||
c9bacfdb | 6365 | putc ('\n', file); |
e881bb1b RH |
6366 | } |
6367 | ||
93cba993 RH |
6368 | void |
6369 | debug_flow_info () | |
6370 | { | |
6371 | dump_flow_info (stderr); | |
6372 | } | |
6373 | ||
e881bb1b RH |
6374 | static void |
6375 | dump_edge_info (file, e, do_succ) | |
6376 | FILE *file; | |
6377 | edge e; | |
6378 | int do_succ; | |
6379 | { | |
6380 | basic_block side = (do_succ ? e->dest : e->src); | |
6381 | ||
6382 | if (side == ENTRY_BLOCK_PTR) | |
6383 | fputs (" ENTRY", file); | |
6384 | else if (side == EXIT_BLOCK_PTR) | |
6385 | fputs (" EXIT", file); | |
6386 | else | |
6387 | fprintf (file, " %d", side->index); | |
6388 | ||
51891abe JH |
6389 | if (e->count) |
6390 | fprintf (file, " count:%d", e->count); | |
6391 | ||
e881bb1b RH |
6392 | if (e->flags) |
6393 | { | |
6f7d635c | 6394 | static const char * const bitnames[] = { |
e881bb1b RH |
6395 | "fallthru", "crit", "ab", "abcall", "eh", "fake" |
6396 | }; | |
6397 | int comma = 0; | |
6398 | int i, flags = e->flags; | |
6399 | ||
6400 | fputc (' ', file); | |
6401 | fputc ('(', file); | |
6402 | for (i = 0; flags; i++) | |
6403 | if (flags & (1 << i)) | |
6404 | { | |
6405 | flags &= ~(1 << i); | |
6406 | ||
6407 | if (comma) | |
6408 | fputc (',', file); | |
9a56f4f6 | 6409 | if (i < (int) ARRAY_SIZE (bitnames)) |
e881bb1b RH |
6410 | fputs (bitnames[i], file); |
6411 | else | |
6412 | fprintf (file, "%d", i); | |
6413 | comma = 1; | |
6414 | } | |
6415 | fputc (')', file); | |
6416 | } | |
d7429b6a | 6417 | } |
3e28fe44 | 6418 | \f |
b7ba4d8d | 6419 | /* Print out one basic block with live information at start and end. */ |
c9bacfdb | 6420 | |
b7ba4d8d ZW |
6421 | void |
6422 | dump_bb (bb, outf) | |
6423 | basic_block bb; | |
6424 | FILE *outf; | |
6425 | { | |
6426 | rtx insn; | |
6427 | rtx last; | |
6428 | edge e; | |
6429 | ||
51891abe JH |
6430 | fprintf (outf, ";; Basic block %d, loop depth %d, count %d", |
6431 | bb->index, bb->loop_depth, bb->count); | |
b7ba4d8d ZW |
6432 | putc ('\n', outf); |
6433 | ||
6434 | fputs (";; Predecessors: ", outf); | |
c9bacfdb | 6435 | for (e = bb->pred; e; e = e->pred_next) |
b7ba4d8d ZW |
6436 | dump_edge_info (outf, e, 0); |
6437 | putc ('\n', outf); | |
6438 | ||
6439 | fputs (";; Registers live at start:", outf); | |
6440 | dump_regset (bb->global_live_at_start, outf); | |
6441 | putc ('\n', outf); | |
6442 | ||
6443 | for (insn = bb->head, last = NEXT_INSN (bb->end); | |
6444 | insn != last; | |
6445 | insn = NEXT_INSN (insn)) | |
6446 | print_rtl_single (outf, insn); | |
6447 | ||
6448 | fputs (";; Registers live at end:", outf); | |
6449 | dump_regset (bb->global_live_at_end, outf); | |
6450 | putc ('\n', outf); | |
6451 | ||
6452 | fputs (";; Successors: ", outf); | |
6453 | for (e = bb->succ; e; e = e->succ_next) | |
6454 | dump_edge_info (outf, e, 1); | |
6455 | putc ('\n', outf); | |
6456 | } | |
6457 | ||
6458 | void | |
6459 | debug_bb (bb) | |
6460 | basic_block bb; | |
6461 | { | |
6462 | dump_bb (bb, stderr); | |
6463 | } | |
6464 | ||
6465 | void | |
6466 | debug_bb_n (n) | |
6467 | int n; | |
6468 | { | |
c9bacfdb | 6469 | dump_bb (BASIC_BLOCK (n), stderr); |
b7ba4d8d ZW |
6470 | } |
6471 | ||
3e28fe44 MM |
6472 | /* Like print_rtl, but also print out live information for the start of each |
6473 | basic block. */ | |
6474 | ||
6475 | void | |
6476 | print_rtl_with_bb (outf, rtx_first) | |
6477 | FILE *outf; | |
6478 | rtx rtx_first; | |
6479 | { | |
6480 | register rtx tmp_rtx; | |
6481 | ||
6482 | if (rtx_first == 0) | |
6483 | fprintf (outf, "(nil)\n"); | |
3e28fe44 MM |
6484 | else |
6485 | { | |
e881bb1b | 6486 | int i; |
3e28fe44 MM |
6487 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
6488 | int max_uid = get_max_uid (); | |
54ea1de9 | 6489 | basic_block *start = (basic_block *) |
67289ea6 | 6490 | xcalloc (max_uid, sizeof (basic_block)); |
54ea1de9 | 6491 | basic_block *end = (basic_block *) |
67289ea6 | 6492 | xcalloc (max_uid, sizeof (basic_block)); |
2a92c071 | 6493 | enum bb_state *in_bb_p = (enum bb_state *) |
67289ea6 | 6494 | xcalloc (max_uid, sizeof (enum bb_state)); |
3e28fe44 | 6495 | |
e881bb1b | 6496 | for (i = n_basic_blocks - 1; i >= 0; i--) |
3e28fe44 | 6497 | { |
e881bb1b | 6498 | basic_block bb = BASIC_BLOCK (i); |
3e28fe44 | 6499 | rtx x; |
e881bb1b RH |
6500 | |
6501 | start[INSN_UID (bb->head)] = bb; | |
6502 | end[INSN_UID (bb->end)] = bb; | |
6503 | for (x = bb->head; x != NULL_RTX; x = NEXT_INSN (x)) | |
3e28fe44 | 6504 | { |
e881bb1b | 6505 | enum bb_state state = IN_MULTIPLE_BB; |
c9bacfdb | 6506 | if (in_bb_p[INSN_UID (x)] == NOT_IN_BB) |
e881bb1b | 6507 | state = IN_ONE_BB; |
c9bacfdb | 6508 | in_bb_p[INSN_UID (x)] = state; |
e881bb1b RH |
6509 | |
6510 | if (x == bb->end) | |
3e28fe44 MM |
6511 | break; |
6512 | } | |
6513 | } | |
6514 | ||
6515 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
6516 | { | |
b707b450 | 6517 | int did_output; |
e881bb1b | 6518 | basic_block bb; |
b707b450 | 6519 | |
e881bb1b | 6520 | if ((bb = start[INSN_UID (tmp_rtx)]) != NULL) |
3e28fe44 MM |
6521 | { |
6522 | fprintf (outf, ";; Start of basic block %d, registers live:", | |
e881bb1b | 6523 | bb->index); |
b7ba4d8d | 6524 | dump_regset (bb->global_live_at_start, outf); |
3e28fe44 MM |
6525 | putc ('\n', outf); |
6526 | } | |
6527 | ||
c9bacfdb | 6528 | if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB |
3e28fe44 | 6529 | && GET_CODE (tmp_rtx) != NOTE |
d29c259b | 6530 | && GET_CODE (tmp_rtx) != BARRIER) |
3e28fe44 | 6531 | fprintf (outf, ";; Insn is not within a basic block\n"); |
c9bacfdb | 6532 | else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB) |
3e28fe44 MM |
6533 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); |
6534 | ||
b707b450 | 6535 | did_output = print_rtl_single (outf, tmp_rtx); |
3e28fe44 | 6536 | |
e881bb1b | 6537 | if ((bb = end[INSN_UID (tmp_rtx)]) != NULL) |
62828c00 RH |
6538 | { |
6539 | fprintf (outf, ";; End of basic block %d, registers live:\n", | |
6540 | bb->index); | |
6541 | dump_regset (bb->global_live_at_end, outf); | |
6542 | putc ('\n', outf); | |
6543 | } | |
3e28fe44 | 6544 | |
b707b450 | 6545 | if (did_output) |
9ec36da5 | 6546 | putc ('\n', outf); |
3e28fe44 | 6547 | } |
67289ea6 MM |
6548 | |
6549 | free (start); | |
6550 | free (end); | |
6551 | free (in_bb_p); | |
3e28fe44 | 6552 | } |
c5c76735 JL |
6553 | |
6554 | if (current_function_epilogue_delay_list != 0) | |
6555 | { | |
6556 | fprintf (outf, "\n;; Insns in epilogue delay list:\n\n"); | |
6557 | for (tmp_rtx = current_function_epilogue_delay_list; tmp_rtx != 0; | |
6558 | tmp_rtx = XEXP (tmp_rtx, 1)) | |
6559 | print_rtl_single (outf, XEXP (tmp_rtx, 0)); | |
6560 | } | |
3e28fe44 | 6561 | } |
5ece9746 | 6562 | |
f9b697bf | 6563 | /* Dump the rtl into the current debugging dump file, then abort. */ |
63c499dc | 6564 | |
f9b697bf | 6565 | static void |
63c499dc RK |
6566 | print_rtl_and_abort_fcn (file, line, function) |
6567 | const char *file; | |
6568 | int line; | |
6569 | const char *function; | |
f9b697bf BS |
6570 | { |
6571 | if (rtl_dump_file) | |
6572 | { | |
6573 | print_rtl_with_bb (rtl_dump_file, get_insns ()); | |
6574 | fclose (rtl_dump_file); | |
6575 | } | |
63c499dc RK |
6576 | |
6577 | fancy_abort (file, line, function); | |
f9b697bf BS |
6578 | } |
6579 | ||
4c649323 JL |
6580 | /* Recompute register set/reference counts immediately prior to register |
6581 | allocation. | |
6582 | ||
6583 | This avoids problems with set/reference counts changing to/from values | |
6584 | which have special meanings to the register allocators. | |
6585 | ||
6586 | Additionally, the reference counts are the primary component used by the | |
6587 | register allocators to prioritize pseudos for allocation to hard regs. | |
6588 | More accurate reference counts generally lead to better register allocation. | |
6589 | ||
213c4983 | 6590 | F is the first insn to be scanned. |
9b15c17f | 6591 | |
213c4983 | 6592 | LOOP_STEP denotes how much loop_depth should be incremented per |
9b15c17f RH |
6593 | loop nesting level in order to increase the ref count more for |
6594 | references in a loop. | |
213c4983 | 6595 | |
4c649323 JL |
6596 | It might be worthwhile to update REG_LIVE_LENGTH, REG_BASIC_BLOCK and |
6597 | possibly other information which is used by the register allocators. */ | |
6598 | ||
762a1d90 | 6599 | void |
213c4983 | 6600 | recompute_reg_usage (f, loop_step) |
272df862 KG |
6601 | rtx f ATTRIBUTE_UNUSED; |
6602 | int loop_step ATTRIBUTE_UNUSED; | |
4c649323 | 6603 | { |
f134997f RH |
6604 | allocate_reg_life_data (); |
6605 | update_life_info (NULL, UPDATE_LIFE_LOCAL, PROP_REG_INFO); | |
4c649323 | 6606 | } |
e881bb1b | 6607 | |
d3a923ee | 6608 | /* Optionally removes all the REG_DEAD and REG_UNUSED notes from a set of |
3071fab5 RH |
6609 | blocks. If BLOCKS is NULL, assume the universal set. Returns a count |
6610 | of the number of registers that died. */ | |
d3a923ee RH |
6611 | |
6612 | int | |
6613 | count_or_remove_death_notes (blocks, kill) | |
c9bacfdb KH |
6614 | sbitmap blocks; |
6615 | int kill; | |
d3a923ee RH |
6616 | { |
6617 | int i, count = 0; | |
6618 | ||
6619 | for (i = n_basic_blocks - 1; i >= 0; --i) | |
6620 | { | |
6621 | basic_block bb; | |
6622 | rtx insn; | |
6623 | ||
3071fab5 | 6624 | if (blocks && ! TEST_BIT (blocks, i)) |
d3a923ee RH |
6625 | continue; |
6626 | ||
6627 | bb = BASIC_BLOCK (i); | |
6628 | ||
c9bacfdb | 6629 | for (insn = bb->head;; insn = NEXT_INSN (insn)) |
d3a923ee | 6630 | { |
2c3c49de | 6631 | if (INSN_P (insn)) |
d3a923ee RH |
6632 | { |
6633 | rtx *pprev = ®_NOTES (insn); | |
6634 | rtx link = *pprev; | |
6635 | ||
6636 | while (link) | |
6637 | { | |
6638 | switch (REG_NOTE_KIND (link)) | |
6639 | { | |
6640 | case REG_DEAD: | |
6641 | if (GET_CODE (XEXP (link, 0)) == REG) | |
6642 | { | |
6643 | rtx reg = XEXP (link, 0); | |
6644 | int n; | |
6645 | ||
6646 | if (REGNO (reg) >= FIRST_PSEUDO_REGISTER) | |
6647 | n = 1; | |
6648 | else | |
6649 | n = HARD_REGNO_NREGS (REGNO (reg), GET_MODE (reg)); | |
6650 | count += n; | |
6651 | } | |
c9bacfdb | 6652 | /* Fall through. */ |
d3a923ee RH |
6653 | |
6654 | case REG_UNUSED: | |
6655 | if (kill) | |
6656 | { | |
6657 | rtx next = XEXP (link, 1); | |
6658 | free_EXPR_LIST_node (link); | |
c9bacfdb KH |
6659 | *pprev = link = next; |
6660 | break; | |
d3a923ee | 6661 | } |
c9bacfdb | 6662 | /* Fall through. */ |
d3a923ee RH |
6663 | |
6664 | default: | |
6665 | pprev = &XEXP (link, 1); | |
6666 | link = *pprev; | |
6667 | break; | |
6668 | } | |
6669 | } | |
6670 | } | |
6671 | ||
6672 | if (insn == bb->end) | |
6673 | break; | |
6674 | } | |
6675 | } | |
6676 | ||
6677 | return count; | |
6678 | } | |
6679 | ||
c586192c MH |
6680 | |
6681 | /* Update insns block within BB. */ | |
6682 | ||
21c7361e | 6683 | void |
c586192c MH |
6684 | update_bb_for_insn (bb) |
6685 | basic_block bb; | |
6686 | { | |
6687 | rtx insn; | |
6688 | ||
6689 | if (! basic_block_for_insn) | |
6690 | return; | |
6691 | ||
6692 | for (insn = bb->head; ; insn = NEXT_INSN (insn)) | |
6693 | { | |
6694 | set_block_for_insn (insn, bb); | |
6695 | ||
6696 | if (insn == bb->end) | |
6697 | break; | |
6698 | } | |
6699 | } | |
6700 | ||
6701 | ||
e881bb1b RH |
6702 | /* Record INSN's block as BB. */ |
6703 | ||
6704 | void | |
6705 | set_block_for_insn (insn, bb) | |
6706 | rtx insn; | |
6707 | basic_block bb; | |
6708 | { | |
6709 | size_t uid = INSN_UID (insn); | |
6710 | if (uid >= basic_block_for_insn->num_elements) | |
6711 | { | |
6712 | int new_size; | |
c9bacfdb | 6713 | |
e881bb1b RH |
6714 | /* Add one-eighth the size so we don't keep calling xrealloc. */ |
6715 | new_size = uid + (uid + 7) / 8; | |
6716 | ||
6717 | VARRAY_GROW (basic_block_for_insn, new_size); | |
6718 | } | |
6719 | VARRAY_BB (basic_block_for_insn, uid) = bb; | |
6720 | } | |
6721 | ||
6722 | /* Record INSN's block number as BB. */ | |
6723 | /* ??? This has got to go. */ | |
6724 | ||
6725 | void | |
6726 | set_block_num (insn, bb) | |
6727 | rtx insn; | |
6728 | int bb; | |
6729 | { | |
6730 | set_block_for_insn (insn, BASIC_BLOCK (bb)); | |
6731 | } | |
34487bf8 | 6732 | \f |
d3a923ee RH |
6733 | /* Verify the CFG consistency. This function check some CFG invariants and |
6734 | aborts when something is wrong. Hope that this function will help to | |
6735 | convert many optimization passes to preserve CFG consistent. | |
f2a1bc02 | 6736 | |
c9bacfdb | 6737 | Currently it does following checks: |
f2a1bc02 | 6738 | |
d3a923ee RH |
6739 | - test head/end pointers |
6740 | - overlapping of basic blocks | |
6741 | - edge list corectness | |
6742 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) | |
6743 | - tails of basic blocks (ensure that boundary is necesary) | |
6744 | - scans body of the basic block for JUMP_INSN, CODE_LABEL | |
6745 | and NOTE_INSN_BASIC_BLOCK | |
c9bacfdb | 6746 | - check that all insns are in the basic blocks |
d3a923ee | 6747 | (except the switch handling code, barriers and notes) |
0edd203b | 6748 | - check that all returns are followed by barriers |
f2a1bc02 | 6749 | |
d3a923ee RH |
6750 | In future it can be extended check a lot of other stuff as well |
6751 | (reachability of basic blocks, life information, etc. etc.). */ | |
f2a1bc02 | 6752 | |
d3a923ee RH |
6753 | void |
6754 | verify_flow_info () | |
f2a1bc02 | 6755 | { |
d3a923ee RH |
6756 | const int max_uid = get_max_uid (); |
6757 | const rtx rtx_first = get_insns (); | |
6ff71a97 | 6758 | rtx last_head = get_last_insn (); |
d3a923ee RH |
6759 | basic_block *bb_info; |
6760 | rtx x; | |
18ca529b | 6761 | int i, last_bb_num_seen, num_bb_notes, err = 0; |
f2a1bc02 | 6762 | |
67289ea6 | 6763 | bb_info = (basic_block *) xcalloc (max_uid, sizeof (basic_block)); |
f2a1bc02 | 6764 | |
d3a923ee | 6765 | for (i = n_basic_blocks - 1; i >= 0; i--) |
f2a1bc02 | 6766 | { |
d3a923ee | 6767 | basic_block bb = BASIC_BLOCK (i); |
6ff71a97 JL |
6768 | rtx head = bb->head; |
6769 | rtx end = bb->end; | |
f2a1bc02 | 6770 | |
6ff71a97 JL |
6771 | /* Verify the end of the basic block is in the INSN chain. */ |
6772 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) | |
6773 | if (x == end) | |
d3a923ee RH |
6774 | break; |
6775 | if (!x) | |
6776 | { | |
6ff71a97 JL |
6777 | error ("End insn %d for block %d not found in the insn stream.", |
6778 | INSN_UID (end), bb->index); | |
d3a923ee RH |
6779 | err = 1; |
6780 | } | |
f2a1bc02 | 6781 | |
6ff71a97 JL |
6782 | /* Work backwards from the end to the head of the basic block |
6783 | to verify the head is in the RTL chain. */ | |
c9bacfdb | 6784 | for (; x != NULL_RTX; x = PREV_INSN (x)) |
f2a1bc02 | 6785 | { |
6ff71a97 JL |
6786 | /* While walking over the insn chain, verify insns appear |
6787 | in only one basic block and initialize the BB_INFO array | |
6788 | used by other passes. */ | |
d3a923ee | 6789 | if (bb_info[INSN_UID (x)] != NULL) |
f2a1bc02 | 6790 | { |
d3a923ee RH |
6791 | error ("Insn %d is in multiple basic blocks (%d and %d)", |
6792 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); | |
6793 | err = 1; | |
f2a1bc02 | 6794 | } |
d3a923ee RH |
6795 | bb_info[INSN_UID (x)] = bb; |
6796 | ||
6ff71a97 | 6797 | if (x == head) |
f2a1bc02 BM |
6798 | break; |
6799 | } | |
d3a923ee RH |
6800 | if (!x) |
6801 | { | |
6ff71a97 JL |
6802 | error ("Head insn %d for block %d not found in the insn stream.", |
6803 | INSN_UID (head), bb->index); | |
d3a923ee RH |
6804 | err = 1; |
6805 | } | |
6ff71a97 JL |
6806 | |
6807 | last_head = x; | |
f2a1bc02 | 6808 | } |
f2a1bc02 | 6809 | |
d3a923ee RH |
6810 | /* Now check the basic blocks (boundaries etc.) */ |
6811 | for (i = n_basic_blocks - 1; i >= 0; i--) | |
f2a1bc02 | 6812 | { |
d3a923ee RH |
6813 | basic_block bb = BASIC_BLOCK (i); |
6814 | /* Check corectness of edge lists */ | |
6815 | edge e; | |
f2a1bc02 | 6816 | |
d3a923ee RH |
6817 | e = bb->succ; |
6818 | while (e) | |
f2a1bc02 | 6819 | { |
d3a923ee | 6820 | if (e->src != bb) |
f2a1bc02 | 6821 | { |
c9bacfdb KH |
6822 | fprintf (stderr, |
6823 | "verify_flow_info: Basic block %d succ edge is corrupted\n", | |
d3a923ee RH |
6824 | bb->index); |
6825 | fprintf (stderr, "Predecessor: "); | |
6826 | dump_edge_info (stderr, e, 0); | |
6827 | fprintf (stderr, "\nSuccessor: "); | |
6828 | dump_edge_info (stderr, e, 1); | |
6829 | fflush (stderr); | |
6830 | err = 1; | |
f2a1bc02 | 6831 | } |
d3a923ee | 6832 | if (e->dest != EXIT_BLOCK_PTR) |
f2a1bc02 | 6833 | { |
d3a923ee RH |
6834 | edge e2 = e->dest->pred; |
6835 | while (e2 && e2 != e) | |
6836 | e2 = e2->pred_next; | |
6837 | if (!e2) | |
6838 | { | |
6839 | error ("Basic block %i edge lists are corrupted", bb->index); | |
6840 | err = 1; | |
6841 | } | |
f2a1bc02 | 6842 | } |
d3a923ee | 6843 | e = e->succ_next; |
f2a1bc02 | 6844 | } |
f2a1bc02 | 6845 | |
d3a923ee RH |
6846 | e = bb->pred; |
6847 | while (e) | |
f2a1bc02 | 6848 | { |
d3a923ee | 6849 | if (e->dest != bb) |
f2a1bc02 | 6850 | { |
d3a923ee RH |
6851 | error ("Basic block %d pred edge is corrupted", bb->index); |
6852 | fputs ("Predecessor: ", stderr); | |
6853 | dump_edge_info (stderr, e, 0); | |
6854 | fputs ("\nSuccessor: ", stderr); | |
6855 | dump_edge_info (stderr, e, 1); | |
6856 | fputc ('\n', stderr); | |
6857 | err = 1; | |
34487bf8 RH |
6858 | } |
6859 | if (e->src != ENTRY_BLOCK_PTR) | |
6860 | { | |
6861 | edge e2 = e->src->succ; | |
6862 | while (e2 && e2 != e) | |
6863 | e2 = e2->succ_next; | |
6864 | if (!e2) | |
6865 | { | |
987009bf | 6866 | error ("Basic block %i edge lists are corrupted", bb->index); |
d3a923ee | 6867 | err = 1; |
34487bf8 RH |
6868 | } |
6869 | } | |
6870 | e = e->pred_next; | |
6871 | } | |
6872 | ||
6873 | /* OK pointers are correct. Now check the header of basic | |
6874 | block. It ought to contain optional CODE_LABEL followed | |
6875 | by NOTE_BASIC_BLOCK. */ | |
6876 | x = bb->head; | |
6877 | if (GET_CODE (x) == CODE_LABEL) | |
6878 | { | |
6879 | if (bb->end == x) | |
6880 | { | |
987009bf ZW |
6881 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", |
6882 | bb->index); | |
d3a923ee | 6883 | err = 1; |
34487bf8 RH |
6884 | } |
6885 | x = NEXT_INSN (x); | |
6886 | } | |
589ca5cb | 6887 | if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb) |
34487bf8 | 6888 | { |
987009bf | 6889 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d\n", |
34487bf8 | 6890 | bb->index); |
d3a923ee | 6891 | err = 1; |
34487bf8 RH |
6892 | } |
6893 | ||
6894 | if (bb->end == x) | |
6895 | { | |
6896 | /* Do checks for empty blocks here */ | |
6897 | } | |
6898 | else | |
6899 | { | |
6900 | x = NEXT_INSN (x); | |
6901 | while (x) | |
6902 | { | |
589ca5cb | 6903 | if (NOTE_INSN_BASIC_BLOCK_P (x)) |
34487bf8 | 6904 | { |
987009bf | 6905 | error ("NOTE_INSN_BASIC_BLOCK %d in the middle of basic block %d", |
34487bf8 | 6906 | INSN_UID (x), bb->index); |
d3a923ee | 6907 | err = 1; |
34487bf8 RH |
6908 | } |
6909 | ||
6910 | if (x == bb->end) | |
6911 | break; | |
6912 | ||
6913 | if (GET_CODE (x) == JUMP_INSN | |
6914 | || GET_CODE (x) == CODE_LABEL | |
6915 | || GET_CODE (x) == BARRIER) | |
6916 | { | |
987009bf ZW |
6917 | error ("In basic block %d:", bb->index); |
6918 | fatal_insn ("Flow control insn inside a basic block", x); | |
34487bf8 RH |
6919 | } |
6920 | ||
6921 | x = NEXT_INSN (x); | |
6922 | } | |
6923 | } | |
6924 | } | |
6925 | ||
18ca529b JE |
6926 | last_bb_num_seen = -1; |
6927 | num_bb_notes = 0; | |
34487bf8 RH |
6928 | x = rtx_first; |
6929 | while (x) | |
6930 | { | |
589ca5cb | 6931 | if (NOTE_INSN_BASIC_BLOCK_P (x)) |
18ca529b JE |
6932 | { |
6933 | basic_block bb = NOTE_BASIC_BLOCK (x); | |
6934 | num_bb_notes++; | |
6935 | if (bb->index != last_bb_num_seen + 1) | |
400500c4 RK |
6936 | /* Basic blocks not numbered consecutively. */ |
6937 | abort (); | |
6938 | ||
18ca529b JE |
6939 | last_bb_num_seen = bb->index; |
6940 | } | |
6941 | ||
34487bf8 RH |
6942 | if (!bb_info[INSN_UID (x)]) |
6943 | { | |
6944 | switch (GET_CODE (x)) | |
6945 | { | |
6946 | case BARRIER: | |
6947 | case NOTE: | |
6948 | break; | |
6949 | ||
6950 | case CODE_LABEL: | |
6951 | /* An addr_vec is placed outside any block block. */ | |
6952 | if (NEXT_INSN (x) | |
6953 | && GET_CODE (NEXT_INSN (x)) == JUMP_INSN | |
6954 | && (GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_DIFF_VEC | |
6955 | || GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_VEC)) | |
6956 | { | |
6957 | x = NEXT_INSN (x); | |
6958 | } | |
6959 | ||
6960 | /* But in any case, non-deletable labels can appear anywhere. */ | |
6961 | break; | |
6962 | ||
6963 | default: | |
987009bf | 6964 | fatal_insn ("Insn outside basic block", x); |
34487bf8 RH |
6965 | } |
6966 | } | |
6967 | ||
2c3c49de | 6968 | if (INSN_P (x) |
0edd203b | 6969 | && GET_CODE (x) == JUMP_INSN |
2ca19d5e | 6970 | && returnjump_p (x) && ! condjump_p (x) |
0edd203b JE |
6971 | && ! (NEXT_INSN (x) && GET_CODE (NEXT_INSN (x)) == BARRIER)) |
6972 | fatal_insn ("Return not followed by barrier", x); | |
6973 | ||
34487bf8 RH |
6974 | x = NEXT_INSN (x); |
6975 | } | |
d3a923ee | 6976 | |
18ca529b | 6977 | if (num_bb_notes != n_basic_blocks) |
400500c4 RK |
6978 | internal_error |
6979 | ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)", | |
6980 | num_bb_notes, n_basic_blocks); | |
18ca529b | 6981 | |
d3a923ee RH |
6982 | if (err) |
6983 | abort (); | |
67289ea6 MM |
6984 | |
6985 | /* Clean up. */ | |
6986 | free (bb_info); | |
34487bf8 | 6987 | } |
410538ea AM |
6988 | \f |
6989 | /* Functions to access an edge list with a vector representation. | |
c9bacfdb | 6990 | Enough data is kept such that given an index number, the |
4eb00163 JO |
6991 | pred and succ that edge represents can be determined, or |
6992 | given a pred and a succ, its index number can be returned. | |
c9bacfdb | 6993 | This allows algorithms which consume a lot of memory to |
410538ea AM |
6994 | represent the normally full matrix of edge (pred,succ) with a |
6995 | single indexed vector, edge (EDGE_INDEX (pred, succ)), with no | |
6996 | wasted space in the client code due to sparse flow graphs. */ | |
6997 | ||
c9bacfdb | 6998 | /* This functions initializes the edge list. Basically the entire |
410538ea | 6999 | flowgraph is processed, and all edges are assigned a number, |
4eb00163 | 7000 | and the data structure is filled in. */ |
c9bacfdb | 7001 | |
410538ea AM |
7002 | struct edge_list * |
7003 | create_edge_list () | |
7004 | { | |
7005 | struct edge_list *elist; | |
7006 | edge e; | |
7007 | int num_edges; | |
e2bef702 | 7008 | int x; |
410538ea AM |
7009 | int block_count; |
7010 | ||
7011 | block_count = n_basic_blocks + 2; /* Include the entry and exit blocks. */ | |
7012 | ||
7013 | num_edges = 0; | |
7014 | ||
7015 | /* Determine the number of edges in the flow graph by counting successor | |
7016 | edges on each basic block. */ | |
7017 | for (x = 0; x < n_basic_blocks; x++) | |
7018 | { | |
7019 | basic_block bb = BASIC_BLOCK (x); | |
7020 | ||
7021 | for (e = bb->succ; e; e = e->succ_next) | |
7022 | num_edges++; | |
7023 | } | |
7024 | /* Don't forget successors of the entry block. */ | |
7025 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) | |
7026 | num_edges++; | |
7027 | ||
2c852885 | 7028 | elist = (struct edge_list *) xmalloc (sizeof (struct edge_list)); |
410538ea AM |
7029 | elist->num_blocks = block_count; |
7030 | elist->num_edges = num_edges; | |
2c852885 | 7031 | elist->index_to_edge = (edge *) xmalloc (sizeof (edge) * num_edges); |
410538ea AM |
7032 | |
7033 | num_edges = 0; | |
7034 | ||
7035 | /* Follow successors of the entry block, and register these edges. */ | |
7036 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) | |
7037 | { | |
7038 | elist->index_to_edge[num_edges] = e; | |
7039 | num_edges++; | |
7040 | } | |
c9bacfdb | 7041 | |
410538ea AM |
7042 | for (x = 0; x < n_basic_blocks; x++) |
7043 | { | |
7044 | basic_block bb = BASIC_BLOCK (x); | |
7045 | ||
7046 | /* Follow all successors of blocks, and register these edges. */ | |
7047 | for (e = bb->succ; e; e = e->succ_next) | |
7048 | { | |
7049 | elist->index_to_edge[num_edges] = e; | |
7050 | num_edges++; | |
7051 | } | |
7052 | } | |
7053 | return elist; | |
7054 | } | |
7055 | ||
7056 | /* This function free's memory associated with an edge list. */ | |
c9bacfdb | 7057 | |
410538ea AM |
7058 | void |
7059 | free_edge_list (elist) | |
7060 | struct edge_list *elist; | |
7061 | { | |
7062 | if (elist) | |
7063 | { | |
7064 | free (elist->index_to_edge); | |
7065 | free (elist); | |
7066 | } | |
7067 | } | |
7068 | ||
7069 | /* This function provides debug output showing an edge list. */ | |
c9bacfdb KH |
7070 | |
7071 | void | |
410538ea AM |
7072 | print_edge_list (f, elist) |
7073 | FILE *f; | |
7074 | struct edge_list *elist; | |
7075 | { | |
7076 | int x; | |
c9bacfdb KH |
7077 | fprintf (f, "Compressed edge list, %d BBs + entry & exit, and %d edges\n", |
7078 | elist->num_blocks - 2, elist->num_edges); | |
410538ea AM |
7079 | |
7080 | for (x = 0; x < elist->num_edges; x++) | |
7081 | { | |
7082 | fprintf (f, " %-4d - edge(", x); | |
7083 | if (INDEX_EDGE_PRED_BB (elist, x) == ENTRY_BLOCK_PTR) | |
c9bacfdb | 7084 | fprintf (f, "entry,"); |
410538ea | 7085 | else |
c9bacfdb | 7086 | fprintf (f, "%d,", INDEX_EDGE_PRED_BB (elist, x)->index); |
410538ea AM |
7087 | |
7088 | if (INDEX_EDGE_SUCC_BB (elist, x) == EXIT_BLOCK_PTR) | |
c9bacfdb | 7089 | fprintf (f, "exit)\n"); |
410538ea | 7090 | else |
c9bacfdb | 7091 | fprintf (f, "%d)\n", INDEX_EDGE_SUCC_BB (elist, x)->index); |
410538ea AM |
7092 | } |
7093 | } | |
7094 | ||
4eb00163 | 7095 | /* This function provides an internal consistency check of an edge list, |
c9bacfdb | 7096 | verifying that all edges are present, and that there are no |
410538ea | 7097 | extra edges. */ |
c9bacfdb | 7098 | |
410538ea AM |
7099 | void |
7100 | verify_edge_list (f, elist) | |
7101 | FILE *f; | |
7102 | struct edge_list *elist; | |
7103 | { | |
7104 | int x, pred, succ, index; | |
410538ea AM |
7105 | edge e; |
7106 | ||
7107 | for (x = 0; x < n_basic_blocks; x++) | |
7108 | { | |
7109 | basic_block bb = BASIC_BLOCK (x); | |
7110 | ||
7111 | for (e = bb->succ; e; e = e->succ_next) | |
7112 | { | |
7113 | pred = e->src->index; | |
7114 | succ = e->dest->index; | |
d675a426 | 7115 | index = EDGE_INDEX (elist, e->src, e->dest); |
410538ea AM |
7116 | if (index == EDGE_INDEX_NO_EDGE) |
7117 | { | |
c9bacfdb | 7118 | fprintf (f, "*p* No index for edge from %d to %d\n", pred, succ); |
410538ea AM |
7119 | continue; |
7120 | } | |
7121 | if (INDEX_EDGE_PRED_BB (elist, index)->index != pred) | |
7122 | fprintf (f, "*p* Pred for index %d should be %d not %d\n", | |
7123 | index, pred, INDEX_EDGE_PRED_BB (elist, index)->index); | |
7124 | if (INDEX_EDGE_SUCC_BB (elist, index)->index != succ) | |
7125 | fprintf (f, "*p* Succ for index %d should be %d not %d\n", | |
7126 | index, succ, INDEX_EDGE_SUCC_BB (elist, index)->index); | |
7127 | } | |
7128 | } | |
7129 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) | |
7130 | { | |
7131 | pred = e->src->index; | |
7132 | succ = e->dest->index; | |
d675a426 | 7133 | index = EDGE_INDEX (elist, e->src, e->dest); |
410538ea AM |
7134 | if (index == EDGE_INDEX_NO_EDGE) |
7135 | { | |
c9bacfdb | 7136 | fprintf (f, "*p* No index for edge from %d to %d\n", pred, succ); |
410538ea AM |
7137 | continue; |
7138 | } | |
7139 | if (INDEX_EDGE_PRED_BB (elist, index)->index != pred) | |
7140 | fprintf (f, "*p* Pred for index %d should be %d not %d\n", | |
7141 | index, pred, INDEX_EDGE_PRED_BB (elist, index)->index); | |
7142 | if (INDEX_EDGE_SUCC_BB (elist, index)->index != succ) | |
7143 | fprintf (f, "*p* Succ for index %d should be %d not %d\n", | |
7144 | index, succ, INDEX_EDGE_SUCC_BB (elist, index)->index); | |
7145 | } | |
7146 | /* We've verified that all the edges are in the list, no lets make sure | |
7147 | there are no spurious edges in the list. */ | |
c9bacfdb KH |
7148 | |
7149 | for (pred = 0; pred < n_basic_blocks; pred++) | |
7150 | for (succ = 0; succ < n_basic_blocks; succ++) | |
410538ea | 7151 | { |
c9bacfdb KH |
7152 | basic_block p = BASIC_BLOCK (pred); |
7153 | basic_block s = BASIC_BLOCK (succ); | |
410538ea | 7154 | |
c9bacfdb | 7155 | int found_edge = 0; |
410538ea | 7156 | |
c9bacfdb KH |
7157 | for (e = p->succ; e; e = e->succ_next) |
7158 | if (e->dest == s) | |
410538ea AM |
7159 | { |
7160 | found_edge = 1; | |
7161 | break; | |
7162 | } | |
c9bacfdb KH |
7163 | for (e = s->pred; e; e = e->pred_next) |
7164 | if (e->src == p) | |
410538ea AM |
7165 | { |
7166 | found_edge = 1; | |
7167 | break; | |
7168 | } | |
c9bacfdb | 7169 | if (EDGE_INDEX (elist, BASIC_BLOCK (pred), BASIC_BLOCK (succ)) |
d675a426 | 7170 | == EDGE_INDEX_NO_EDGE && found_edge != 0) |
410538ea | 7171 | fprintf (f, "*** Edge (%d, %d) appears to not have an index\n", |
c9bacfdb KH |
7172 | pred, succ); |
7173 | if (EDGE_INDEX (elist, BASIC_BLOCK (pred), BASIC_BLOCK (succ)) | |
d675a426 | 7174 | != EDGE_INDEX_NO_EDGE && found_edge == 0) |
410538ea | 7175 | fprintf (f, "*** Edge (%d, %d) has index %d, but there is no edge\n", |
21c7361e | 7176 | pred, succ, EDGE_INDEX (elist, BASIC_BLOCK (pred), |
d675a426 | 7177 | BASIC_BLOCK (succ))); |
410538ea | 7178 | } |
c9bacfdb KH |
7179 | for (succ = 0; succ < n_basic_blocks; succ++) |
7180 | { | |
7181 | basic_block p = ENTRY_BLOCK_PTR; | |
7182 | basic_block s = BASIC_BLOCK (succ); | |
410538ea | 7183 | |
c9bacfdb | 7184 | int found_edge = 0; |
410538ea | 7185 | |
c9bacfdb KH |
7186 | for (e = p->succ; e; e = e->succ_next) |
7187 | if (e->dest == s) | |
7188 | { | |
7189 | found_edge = 1; | |
7190 | break; | |
7191 | } | |
7192 | for (e = s->pred; e; e = e->pred_next) | |
7193 | if (e->src == p) | |
7194 | { | |
7195 | found_edge = 1; | |
7196 | break; | |
7197 | } | |
7198 | if (EDGE_INDEX (elist, ENTRY_BLOCK_PTR, BASIC_BLOCK (succ)) | |
7199 | == EDGE_INDEX_NO_EDGE && found_edge != 0) | |
7200 | fprintf (f, "*** Edge (entry, %d) appears to not have an index\n", | |
7201 | succ); | |
7202 | if (EDGE_INDEX (elist, ENTRY_BLOCK_PTR, BASIC_BLOCK (succ)) | |
7203 | != EDGE_INDEX_NO_EDGE && found_edge == 0) | |
7204 | fprintf (f, "*** Edge (entry, %d) has index %d, but no edge exists\n", | |
7205 | succ, EDGE_INDEX (elist, ENTRY_BLOCK_PTR, | |
7206 | BASIC_BLOCK (succ))); | |
7207 | } | |
7208 | for (pred = 0; pred < n_basic_blocks; pred++) | |
7209 | { | |
7210 | basic_block p = BASIC_BLOCK (pred); | |
7211 | basic_block s = EXIT_BLOCK_PTR; | |
410538ea | 7212 | |
c9bacfdb | 7213 | int found_edge = 0; |
410538ea | 7214 | |
c9bacfdb KH |
7215 | for (e = p->succ; e; e = e->succ_next) |
7216 | if (e->dest == s) | |
7217 | { | |
7218 | found_edge = 1; | |
7219 | break; | |
7220 | } | |
7221 | for (e = s->pred; e; e = e->pred_next) | |
7222 | if (e->src == p) | |
7223 | { | |
7224 | found_edge = 1; | |
7225 | break; | |
7226 | } | |
7227 | if (EDGE_INDEX (elist, BASIC_BLOCK (pred), EXIT_BLOCK_PTR) | |
7228 | == EDGE_INDEX_NO_EDGE && found_edge != 0) | |
7229 | fprintf (f, "*** Edge (%d, exit) appears to not have an index\n", | |
7230 | pred); | |
7231 | if (EDGE_INDEX (elist, BASIC_BLOCK (pred), EXIT_BLOCK_PTR) | |
7232 | != EDGE_INDEX_NO_EDGE && found_edge == 0) | |
7233 | fprintf (f, "*** Edge (%d, exit) has index %d, but no edge exists\n", | |
7234 | pred, EDGE_INDEX (elist, BASIC_BLOCK (pred), | |
7235 | EXIT_BLOCK_PTR)); | |
7236 | } | |
410538ea AM |
7237 | } |
7238 | ||
7239 | /* This routine will determine what, if any, edge there is between | |
7240 | a specified predecessor and successor. */ | |
c9bacfdb | 7241 | |
410538ea AM |
7242 | int |
7243 | find_edge_index (edge_list, pred, succ) | |
7244 | struct edge_list *edge_list; | |
d675a426 | 7245 | basic_block pred, succ; |
410538ea AM |
7246 | { |
7247 | int x; | |
7248 | for (x = 0; x < NUM_EDGES (edge_list); x++) | |
7249 | { | |
d675a426 AM |
7250 | if (INDEX_EDGE_PRED_BB (edge_list, x) == pred |
7251 | && INDEX_EDGE_SUCC_BB (edge_list, x) == succ) | |
410538ea AM |
7252 | return x; |
7253 | } | |
7254 | return (EDGE_INDEX_NO_EDGE); | |
7255 | } | |
7256 | ||
87fdf7ff | 7257 | /* This function will remove an edge from the flow graph. */ |
c9bacfdb | 7258 | |
69732dcb | 7259 | void |
87fdf7ff AM |
7260 | remove_edge (e) |
7261 | edge e; | |
7262 | { | |
7263 | edge last_pred = NULL; | |
7264 | edge last_succ = NULL; | |
7265 | edge tmp; | |
7266 | basic_block src, dest; | |
7267 | src = e->src; | |
7268 | dest = e->dest; | |
7269 | for (tmp = src->succ; tmp && tmp != e; tmp = tmp->succ_next) | |
7270 | last_succ = tmp; | |
7271 | ||
7272 | if (!tmp) | |
7273 | abort (); | |
7274 | if (last_succ) | |
7275 | last_succ->succ_next = e->succ_next; | |
7276 | else | |
7277 | src->succ = e->succ_next; | |
7278 | ||
7279 | for (tmp = dest->pred; tmp && tmp != e; tmp = tmp->pred_next) | |
7280 | last_pred = tmp; | |
7281 | ||
7282 | if (!tmp) | |
7283 | abort (); | |
7284 | if (last_pred) | |
7285 | last_pred->pred_next = e->pred_next; | |
7286 | else | |
7287 | dest->pred = e->pred_next; | |
7288 | ||
d3a923ee | 7289 | n_edges--; |
87fdf7ff | 7290 | free (e); |
87fdf7ff AM |
7291 | } |
7292 | ||
7293 | /* This routine will remove any fake successor edges for a basic block. | |
7294 | When the edge is removed, it is also removed from whatever predecessor | |
7295 | list it is in. */ | |
c9bacfdb | 7296 | |
87fdf7ff AM |
7297 | static void |
7298 | remove_fake_successors (bb) | |
7299 | basic_block bb; | |
7300 | { | |
7301 | edge e; | |
c9bacfdb | 7302 | for (e = bb->succ; e;) |
87fdf7ff AM |
7303 | { |
7304 | edge tmp = e; | |
7305 | e = e->succ_next; | |
7306 | if ((tmp->flags & EDGE_FAKE) == EDGE_FAKE) | |
7307 | remove_edge (tmp); | |
7308 | } | |
7309 | } | |
7310 | ||
7311 | /* This routine will remove all fake edges from the flow graph. If | |
7312 | we remove all fake successors, it will automatically remove all | |
7313 | fake predecessors. */ | |
c9bacfdb | 7314 | |
87fdf7ff AM |
7315 | void |
7316 | remove_fake_edges () | |
7317 | { | |
7318 | int x; | |
87fdf7ff AM |
7319 | |
7320 | for (x = 0; x < n_basic_blocks; x++) | |
d3a923ee RH |
7321 | remove_fake_successors (BASIC_BLOCK (x)); |
7322 | ||
c7d04f29 | 7323 | /* We've handled all successors except the entry block's. */ |
87fdf7ff AM |
7324 | remove_fake_successors (ENTRY_BLOCK_PTR); |
7325 | } | |
7326 | ||
4eb00163 | 7327 | /* This function will add a fake edge between any block which has no |
87fdf7ff AM |
7328 | successors, and the exit block. Some data flow equations require these |
7329 | edges to exist. */ | |
c9bacfdb | 7330 | |
87fdf7ff | 7331 | void |
c7d04f29 | 7332 | add_noreturn_fake_exit_edges () |
87fdf7ff AM |
7333 | { |
7334 | int x; | |
7335 | ||
7336 | for (x = 0; x < n_basic_blocks; x++) | |
7337 | if (BASIC_BLOCK (x)->succ == NULL) | |
dbf08f94 | 7338 | make_edge (NULL, BASIC_BLOCK (x), EXIT_BLOCK_PTR, EDGE_FAKE); |
87fdf7ff | 7339 | } |
f008a564 | 7340 | |
b53978a3 JO |
7341 | /* This function adds a fake edge between any infinite loops to the |
7342 | exit block. Some optimizations require a path from each node to | |
7343 | the exit node. | |
f008a564 | 7344 | |
b53978a3 JO |
7345 | See also Morgan, Figure 3.10, pp. 82-83. |
7346 | ||
7347 | The current implementation is ugly, not attempting to minimize the | |
7348 | number of inserted fake edges. To reduce the number of fake edges | |
7349 | to insert, add fake edges from _innermost_ loops containing only | |
c9bacfdb KH |
7350 | nodes not reachable from the exit block. */ |
7351 | ||
b53978a3 JO |
7352 | void |
7353 | connect_infinite_loops_to_exit () | |
7354 | { | |
7355 | basic_block unvisited_block; | |
7356 | ||
7357 | /* Perform depth-first search in the reverse graph to find nodes | |
c9bacfdb | 7358 | reachable from the exit block. */ |
b53978a3 JO |
7359 | struct depth_first_search_dsS dfs_ds; |
7360 | ||
7361 | flow_dfs_compute_reverse_init (&dfs_ds); | |
7362 | flow_dfs_compute_reverse_add_bb (&dfs_ds, EXIT_BLOCK_PTR); | |
c9bacfdb KH |
7363 | |
7364 | /* Repeatedly add fake edges, updating the unreachable nodes. */ | |
b53978a3 JO |
7365 | while (1) |
7366 | { | |
7367 | unvisited_block = flow_dfs_compute_reverse_execute (&dfs_ds); | |
7368 | if (!unvisited_block) | |
7369 | break; | |
7370 | make_edge (NULL, unvisited_block, EXIT_BLOCK_PTR, EDGE_FAKE); | |
7371 | flow_dfs_compute_reverse_add_bb (&dfs_ds, unvisited_block); | |
7372 | } | |
7373 | ||
7374 | flow_dfs_compute_reverse_finish (&dfs_ds); | |
7375 | ||
7376 | return; | |
7377 | } | |
7378 | ||
7379 | /* Redirect an edge's successor from one block to another. */ | |
c9bacfdb | 7380 | |
f008a564 RH |
7381 | void |
7382 | redirect_edge_succ (e, new_succ) | |
7383 | edge e; | |
7384 | basic_block new_succ; | |
7385 | { | |
7386 | edge *pe; | |
7387 | ||
7388 | /* Disconnect the edge from the old successor block. */ | |
c9bacfdb | 7389 | for (pe = &e->dest->pred; *pe != e; pe = &(*pe)->pred_next) |
f008a564 RH |
7390 | continue; |
7391 | *pe = (*pe)->pred_next; | |
7392 | ||
7393 | /* Reconnect the edge to the new successor block. */ | |
7394 | e->pred_next = new_succ->pred; | |
7395 | new_succ->pred = e; | |
7396 | e->dest = new_succ; | |
7397 | } | |
7398 | ||
7399 | /* Redirect an edge's predecessor from one block to another. */ | |
c9bacfdb | 7400 | |
f008a564 RH |
7401 | void |
7402 | redirect_edge_pred (e, new_pred) | |
7403 | edge e; | |
7404 | basic_block new_pred; | |
7405 | { | |
7406 | edge *pe; | |
7407 | ||
7408 | /* Disconnect the edge from the old predecessor block. */ | |
c9bacfdb | 7409 | for (pe = &e->src->succ; *pe != e; pe = &(*pe)->succ_next) |
f008a564 RH |
7410 | continue; |
7411 | *pe = (*pe)->succ_next; | |
7412 | ||
7413 | /* Reconnect the edge to the new predecessor block. */ | |
7414 | e->succ_next = new_pred->succ; | |
7415 | new_pred->succ = e; | |
7416 | e->src = new_pred; | |
7417 | } | |
4dc9341c MH |
7418 | \f |
7419 | /* Dump the list of basic blocks in the bitmap NODES. */ | |
c9bacfdb | 7420 | |
21c7361e | 7421 | static void |
4dc9341c MH |
7422 | flow_nodes_print (str, nodes, file) |
7423 | const char *str; | |
7424 | const sbitmap nodes; | |
7425 | FILE *file; | |
7426 | { | |
7427 | int node; | |
7428 | ||
135ebc36 MH |
7429 | if (! nodes) |
7430 | return; | |
7431 | ||
4dc9341c MH |
7432 | fprintf (file, "%s { ", str); |
7433 | EXECUTE_IF_SET_IN_SBITMAP (nodes, 0, node, {fprintf (file, "%d ", node);}); | |
7434 | fputs ("}\n", file); | |
7435 | } | |
7436 | ||
c9bacfdb | 7437 | |
135ebc36 MH |
7438 | /* Dump the list of edges in the array EDGE_LIST. */ |
7439 | ||
21c7361e | 7440 | static void |
135ebc36 | 7441 | flow_edge_list_print (str, edge_list, num_edges, file) |
4dc9341c | 7442 | const char *str; |
135ebc36 | 7443 | const edge *edge_list; |
4dc9341c MH |
7444 | int num_edges; |
7445 | FILE *file; | |
7446 | { | |
7447 | int i; | |
7448 | ||
135ebc36 MH |
7449 | if (! edge_list) |
7450 | return; | |
7451 | ||
4dc9341c MH |
7452 | fprintf (file, "%s { ", str); |
7453 | for (i = 0; i < num_edges; i++) | |
135ebc36 MH |
7454 | fprintf (file, "%d->%d ", edge_list[i]->src->index, |
7455 | edge_list[i]->dest->index); | |
4dc9341c MH |
7456 | fputs ("}\n", file); |
7457 | } | |
7458 | ||
135ebc36 | 7459 | |
4dc9341c | 7460 | /* Dump loop related CFG information. */ |
c9bacfdb | 7461 | |
4dc9341c MH |
7462 | static void |
7463 | flow_loops_cfg_dump (loops, file) | |
7464 | const struct loops *loops; | |
7465 | FILE *file; | |
7466 | { | |
7467 | int i; | |
7468 | ||
7469 | if (! loops->num || ! file || ! loops->cfg.dom) | |
7470 | return; | |
7471 | ||
7472 | for (i = 0; i < n_basic_blocks; i++) | |
7473 | { | |
7474 | edge succ; | |
7475 | ||
7476 | fprintf (file, ";; %d succs { ", i); | |
7477 | for (succ = BASIC_BLOCK (i)->succ; succ; succ = succ->succ_next) | |
7478 | fprintf (file, "%d ", succ->dest->index); | |
c9bacfdb | 7479 | flow_nodes_print ("} dom", loops->cfg.dom[i], file); |
4dc9341c MH |
7480 | } |
7481 | ||
4dc9341c MH |
7482 | /* Dump the DFS node order. */ |
7483 | if (loops->cfg.dfs_order) | |
7484 | { | |
7485 | fputs (";; DFS order: ", file); | |
7486 | for (i = 0; i < n_basic_blocks; i++) | |
7487 | fprintf (file, "%d ", loops->cfg.dfs_order[i]); | |
7488 | fputs ("\n", file); | |
7489 | } | |
c34d5374 MH |
7490 | /* Dump the reverse completion node order. */ |
7491 | if (loops->cfg.rc_order) | |
7492 | { | |
7493 | fputs (";; RC order: ", file); | |
7494 | for (i = 0; i < n_basic_blocks; i++) | |
7495 | fprintf (file, "%d ", loops->cfg.rc_order[i]); | |
7496 | fputs ("\n", file); | |
7497 | } | |
4dc9341c MH |
7498 | } |
7499 | ||
4dc9341c | 7500 | /* Return non-zero if the nodes of LOOP are a subset of OUTER. */ |
c9bacfdb | 7501 | |
272df862 | 7502 | static int |
4dc9341c MH |
7503 | flow_loop_nested_p (outer, loop) |
7504 | struct loop *outer; | |
7505 | struct loop *loop; | |
7506 | { | |
7507 | return sbitmap_a_subset_b_p (loop->nodes, outer->nodes); | |
7508 | } | |
7509 | ||
c9bacfdb | 7510 | |
6057c0e6 MH |
7511 | /* Dump the loop information specified by LOOP to the stream FILE |
7512 | using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ | |
c9bacfdb | 7513 | void |
6057c0e6 MH |
7514 | flow_loop_dump (loop, file, loop_dump_aux, verbose) |
7515 | const struct loop *loop; | |
7516 | FILE *file; | |
31a1fdad | 7517 | void (*loop_dump_aux) PARAMS((const struct loop *, FILE *, int)); |
6057c0e6 MH |
7518 | int verbose; |
7519 | { | |
7520 | if (! loop || ! loop->header) | |
7521 | return; | |
7522 | ||
7523 | fprintf (file, ";;\n;; Loop %d (%d to %d):%s%s\n", | |
7524 | loop->num, INSN_UID (loop->first->head), | |
7525 | INSN_UID (loop->last->end), | |
7526 | loop->shared ? " shared" : "", | |
7527 | loop->invalid ? " invalid" : ""); | |
7528 | fprintf (file, ";; header %d, latch %d, pre-header %d, first %d, last %d\n", | |
7529 | loop->header->index, loop->latch->index, | |
7530 | loop->pre_header ? loop->pre_header->index : -1, | |
7531 | loop->first->index, loop->last->index); | |
7532 | fprintf (file, ";; depth %d, level %d, outer %ld\n", | |
7533 | loop->depth, loop->level, | |
7534 | (long) (loop->outer ? loop->outer->num : -1)); | |
7535 | ||
4a7da9b5 MH |
7536 | if (loop->pre_header_edges) |
7537 | flow_edge_list_print (";; pre-header edges", loop->pre_header_edges, | |
7538 | loop->num_pre_header_edges, file); | |
5d6a16e2 | 7539 | flow_edge_list_print (";; entry edges", loop->entry_edges, |
135ebc36 | 7540 | loop->num_entries, file); |
6057c0e6 MH |
7541 | fprintf (file, ";; %d", loop->num_nodes); |
7542 | flow_nodes_print (" nodes", loop->nodes, file); | |
5d6a16e2 | 7543 | flow_edge_list_print (";; exit edges", loop->exit_edges, |
135ebc36 | 7544 | loop->num_exits, file); |
5d6a16e2 MH |
7545 | if (loop->exits_doms) |
7546 | flow_nodes_print (";; exit doms", loop->exits_doms, file); | |
6057c0e6 MH |
7547 | if (loop_dump_aux) |
7548 | loop_dump_aux (loop, file, verbose); | |
7549 | } | |
7550 | ||
7551 | ||
7552 | /* Dump the loop information specified by LOOPS to the stream FILE, | |
7553 | using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ | |
21c7361e | 7554 | void |
6057c0e6 | 7555 | flow_loops_dump (loops, file, loop_dump_aux, verbose) |
4dc9341c MH |
7556 | const struct loops *loops; |
7557 | FILE *file; | |
31a1fdad | 7558 | void (*loop_dump_aux) PARAMS((const struct loop *, FILE *, int)); |
4dc9341c MH |
7559 | int verbose; |
7560 | { | |
7561 | int i; | |
7562 | int num_loops; | |
7563 | ||
7564 | num_loops = loops->num; | |
7565 | if (! num_loops || ! file) | |
7566 | return; | |
7567 | ||
21c7361e | 7568 | fprintf (file, ";; %d loops found, %d levels\n", |
d6181b1b | 7569 | num_loops, loops->levels); |
4dc9341c MH |
7570 | |
7571 | for (i = 0; i < num_loops; i++) | |
7572 | { | |
7573 | struct loop *loop = &loops->array[i]; | |
7574 | ||
6057c0e6 | 7575 | flow_loop_dump (loop, file, loop_dump_aux, verbose); |
4dc9341c MH |
7576 | |
7577 | if (loop->shared) | |
7578 | { | |
7579 | int j; | |
7580 | ||
7581 | for (j = 0; j < i; j++) | |
7582 | { | |
7583 | struct loop *oloop = &loops->array[j]; | |
7584 | ||
7585 | if (loop->header == oloop->header) | |
7586 | { | |
7587 | int disjoint; | |
7588 | int smaller; | |
7589 | ||
7590 | smaller = loop->num_nodes < oloop->num_nodes; | |
7591 | ||
7592 | /* If the union of LOOP and OLOOP is different than | |
7593 | the larger of LOOP and OLOOP then LOOP and OLOOP | |
7594 | must be disjoint. */ | |
b760c4b1 MH |
7595 | disjoint = ! flow_loop_nested_p (smaller ? loop : oloop, |
7596 | smaller ? oloop : loop); | |
21c7361e | 7597 | fprintf (file, |
c34d5374 | 7598 | ";; loop header %d shared by loops %d, %d %s\n", |
4dc9341c MH |
7599 | loop->header->index, i, j, |
7600 | disjoint ? "disjoint" : "nested"); | |
7601 | } | |
7602 | } | |
7603 | } | |
4dc9341c MH |
7604 | } |
7605 | ||
7606 | if (verbose) | |
7607 | flow_loops_cfg_dump (loops, file); | |
7608 | } | |
7609 | ||
6057c0e6 | 7610 | |
4dc9341c | 7611 | /* Free all the memory allocated for LOOPS. */ |
c9bacfdb KH |
7612 | |
7613 | void | |
4dc9341c | 7614 | flow_loops_free (loops) |
c9bacfdb | 7615 | struct loops *loops; |
4dc9341c MH |
7616 | { |
7617 | if (loops->array) | |
7618 | { | |
7619 | int i; | |
7620 | ||
7621 | if (! loops->num) | |
7622 | abort (); | |
7623 | ||
7624 | /* Free the loop descriptors. */ | |
7625 | for (i = 0; i < loops->num; i++) | |
7626 | { | |
7627 | struct loop *loop = &loops->array[i]; | |
c9bacfdb | 7628 | |
4a7da9b5 MH |
7629 | if (loop->pre_header_edges) |
7630 | free (loop->pre_header_edges); | |
4dc9341c MH |
7631 | if (loop->nodes) |
7632 | sbitmap_free (loop->nodes); | |
135ebc36 MH |
7633 | if (loop->entry_edges) |
7634 | free (loop->entry_edges); | |
7635 | if (loop->exit_edges) | |
7636 | free (loop->exit_edges); | |
5d6a16e2 MH |
7637 | if (loop->exits_doms) |
7638 | sbitmap_free (loop->exits_doms); | |
4dc9341c MH |
7639 | } |
7640 | free (loops->array); | |
7641 | loops->array = NULL; | |
c9bacfdb | 7642 | |
4dc9341c MH |
7643 | if (loops->cfg.dom) |
7644 | sbitmap_vector_free (loops->cfg.dom); | |
7645 | if (loops->cfg.dfs_order) | |
7646 | free (loops->cfg.dfs_order); | |
7647 | ||
5d6a16e2 MH |
7648 | if (loops->shared_headers) |
7649 | sbitmap_free (loops->shared_headers); | |
4dc9341c MH |
7650 | } |
7651 | } | |
7652 | ||
6057c0e6 | 7653 | |
135ebc36 MH |
7654 | /* Find the entry edges into the loop with header HEADER and nodes |
7655 | NODES and store in ENTRY_EDGES array. Return the number of entry | |
7656 | edges from the loop. */ | |
7657 | ||
7658 | static int | |
7659 | flow_loop_entry_edges_find (header, nodes, entry_edges) | |
7660 | basic_block header; | |
7661 | const sbitmap nodes; | |
7662 | edge **entry_edges; | |
7663 | { | |
7664 | edge e; | |
7665 | int num_entries; | |
7666 | ||
7667 | *entry_edges = NULL; | |
7668 | ||
7669 | num_entries = 0; | |
7670 | for (e = header->pred; e; e = e->pred_next) | |
7671 | { | |
7672 | basic_block src = e->src; | |
21c7361e | 7673 | |
135ebc36 MH |
7674 | if (src == ENTRY_BLOCK_PTR || ! TEST_BIT (nodes, src->index)) |
7675 | num_entries++; | |
7676 | } | |
7677 | ||
7678 | if (! num_entries) | |
7679 | abort (); | |
7680 | ||
7681 | *entry_edges = (edge *) xmalloc (num_entries * sizeof (edge *)); | |
7682 | ||
7683 | num_entries = 0; | |
7684 | for (e = header->pred; e; e = e->pred_next) | |
7685 | { | |
7686 | basic_block src = e->src; | |
21c7361e | 7687 | |
135ebc36 MH |
7688 | if (src == ENTRY_BLOCK_PTR || ! TEST_BIT (nodes, src->index)) |
7689 | (*entry_edges)[num_entries++] = e; | |
7690 | } | |
7691 | ||
7692 | return num_entries; | |
7693 | } | |
7694 | ||
7695 | ||
7696 | /* Find the exit edges from the loop using the bitmap of loop nodes | |
7697 | NODES and store in EXIT_EDGES array. Return the number of | |
7698 | exit edges from the loop. */ | |
c9bacfdb | 7699 | |
4dc9341c | 7700 | static int |
135ebc36 | 7701 | flow_loop_exit_edges_find (nodes, exit_edges) |
4dc9341c | 7702 | const sbitmap nodes; |
135ebc36 | 7703 | edge **exit_edges; |
4dc9341c MH |
7704 | { |
7705 | edge e; | |
7706 | int node; | |
7707 | int num_exits; | |
7708 | ||
135ebc36 | 7709 | *exit_edges = NULL; |
4dc9341c MH |
7710 | |
7711 | /* Check all nodes within the loop to see if there are any | |
7712 | successors not in the loop. Note that a node may have multiple | |
135ebc36 MH |
7713 | exiting edges ????? A node can have one jumping edge and one fallthru |
7714 | edge so only one of these can exit the loop. */ | |
4dc9341c MH |
7715 | num_exits = 0; |
7716 | EXECUTE_IF_SET_IN_SBITMAP (nodes, 0, node, { | |
7717 | for (e = BASIC_BLOCK (node)->succ; e; e = e->succ_next) | |
7718 | { | |
21c7361e | 7719 | basic_block dest = e->dest; |
4dc9341c MH |
7720 | |
7721 | if (dest == EXIT_BLOCK_PTR || ! TEST_BIT (nodes, dest->index)) | |
7722 | num_exits++; | |
7723 | } | |
7724 | }); | |
7725 | ||
7726 | if (! num_exits) | |
7727 | return 0; | |
7728 | ||
135ebc36 | 7729 | *exit_edges = (edge *) xmalloc (num_exits * sizeof (edge *)); |
4dc9341c MH |
7730 | |
7731 | /* Store all exiting edges into an array. */ | |
7732 | num_exits = 0; | |
7733 | EXECUTE_IF_SET_IN_SBITMAP (nodes, 0, node, { | |
7734 | for (e = BASIC_BLOCK (node)->succ; e; e = e->succ_next) | |
7735 | { | |
21c7361e | 7736 | basic_block dest = e->dest; |
4dc9341c MH |
7737 | |
7738 | if (dest == EXIT_BLOCK_PTR || ! TEST_BIT (nodes, dest->index)) | |
135ebc36 | 7739 | (*exit_edges)[num_exits++] = e; |
4dc9341c MH |
7740 | } |
7741 | }); | |
7742 | ||
7743 | return num_exits; | |
7744 | } | |
7745 | ||
135ebc36 | 7746 | |
4dc9341c MH |
7747 | /* Find the nodes contained within the loop with header HEADER and |
7748 | latch LATCH and store in NODES. Return the number of nodes within | |
7749 | the loop. */ | |
c9bacfdb KH |
7750 | |
7751 | static int | |
4dc9341c MH |
7752 | flow_loop_nodes_find (header, latch, nodes) |
7753 | basic_block header; | |
7754 | basic_block latch; | |
7755 | sbitmap nodes; | |
7756 | { | |
7757 | basic_block *stack; | |
7758 | int sp; | |
7759 | int num_nodes = 0; | |
7760 | ||
7761 | stack = (basic_block *) xmalloc (n_basic_blocks * sizeof (basic_block)); | |
7762 | sp = 0; | |
7763 | ||
7764 | /* Start with only the loop header in the set of loop nodes. */ | |
7765 | sbitmap_zero (nodes); | |
7766 | SET_BIT (nodes, header->index); | |
7767 | num_nodes++; | |
ce4bbac7 | 7768 | header->loop_depth++; |
4dc9341c MH |
7769 | |
7770 | /* Push the loop latch on to the stack. */ | |
7771 | if (! TEST_BIT (nodes, latch->index)) | |
7772 | { | |
7773 | SET_BIT (nodes, latch->index); | |
ce4bbac7 | 7774 | latch->loop_depth++; |
4dc9341c MH |
7775 | num_nodes++; |
7776 | stack[sp++] = latch; | |
7777 | } | |
7778 | ||
7779 | while (sp) | |
7780 | { | |
7781 | basic_block node; | |
7782 | edge e; | |
7783 | ||
7784 | node = stack[--sp]; | |
7785 | for (e = node->pred; e; e = e->pred_next) | |
7786 | { | |
7787 | basic_block ancestor = e->src; | |
c9bacfdb | 7788 | |
4dc9341c MH |
7789 | /* If each ancestor not marked as part of loop, add to set of |
7790 | loop nodes and push on to stack. */ | |
7791 | if (ancestor != ENTRY_BLOCK_PTR | |
7792 | && ! TEST_BIT (nodes, ancestor->index)) | |
7793 | { | |
7794 | SET_BIT (nodes, ancestor->index); | |
ce4bbac7 | 7795 | ancestor->loop_depth++; |
4dc9341c MH |
7796 | num_nodes++; |
7797 | stack[sp++] = ancestor; | |
7798 | } | |
7799 | } | |
7800 | } | |
7801 | free (stack); | |
7802 | return num_nodes; | |
7803 | } | |
7804 | ||
4dc9341c | 7805 | /* Compute the depth first search order and store in the array |
c34d5374 MH |
7806 | DFS_ORDER if non-zero, marking the nodes visited in VISITED. If |
7807 | RC_ORDER is non-zero, return the reverse completion number for each | |
7808 | node. Returns the number of nodes visited. A depth first search | |
7809 | tries to get as far away from the starting point as quickly as | |
7810 | possible. */ | |
c9bacfdb | 7811 | |
4dc9341c | 7812 | static int |
c34d5374 | 7813 | flow_depth_first_order_compute (dfs_order, rc_order) |
4dc9341c | 7814 | int *dfs_order; |
c34d5374 | 7815 | int *rc_order; |
4dc9341c | 7816 | { |
4dc9341c MH |
7817 | edge *stack; |
7818 | int sp; | |
7819 | int dfsnum = 0; | |
c34d5374 | 7820 | int rcnum = n_basic_blocks - 1; |
4dc9341c MH |
7821 | sbitmap visited; |
7822 | ||
7823 | /* Allocate stack for back-tracking up CFG. */ | |
628f05b4 | 7824 | stack = (edge *) xmalloc ((n_basic_blocks + 1) * sizeof (edge)); |
4dc9341c MH |
7825 | sp = 0; |
7826 | ||
7827 | /* Allocate bitmap to track nodes that have been visited. */ | |
7828 | visited = sbitmap_alloc (n_basic_blocks); | |
7829 | ||
7830 | /* None of the nodes in the CFG have been visited yet. */ | |
7831 | sbitmap_zero (visited); | |
c9bacfdb | 7832 | |
628f05b4 MH |
7833 | /* Push the first edge on to the stack. */ |
7834 | stack[sp++] = ENTRY_BLOCK_PTR->succ; | |
7835 | ||
7836 | while (sp) | |
4dc9341c | 7837 | { |
628f05b4 MH |
7838 | edge e; |
7839 | basic_block src; | |
7840 | basic_block dest; | |
7841 | ||
7842 | /* Look at the edge on the top of the stack. */ | |
7843 | e = stack[sp - 1]; | |
7844 | src = e->src; | |
7845 | dest = e->dest; | |
c9bacfdb | 7846 | |
628f05b4 MH |
7847 | /* Check if the edge destination has been visited yet. */ |
7848 | if (dest != EXIT_BLOCK_PTR && ! TEST_BIT (visited, dest->index)) | |
4dc9341c | 7849 | { |
628f05b4 MH |
7850 | /* Mark that we have visited the destination. */ |
7851 | SET_BIT (visited, dest->index); | |
c9bacfdb | 7852 | |
c34d5374 MH |
7853 | if (dfs_order) |
7854 | dfs_order[dfsnum++] = dest->index; | |
628f05b4 | 7855 | |
c9bacfdb KH |
7856 | if (dest->succ) |
7857 | { | |
7858 | /* Since the DEST node has been visited for the first | |
7859 | time, check its successors. */ | |
7860 | stack[sp++] = dest->succ; | |
7861 | } | |
7862 | else | |
7863 | { | |
7864 | /* There are no successors for the DEST node so assign | |
7865 | its reverse completion number. */ | |
c34d5374 MH |
7866 | if (rc_order) |
7867 | rc_order[rcnum--] = dest->index; | |
c9bacfdb | 7868 | } |
4dc9341c MH |
7869 | } |
7870 | else | |
7871 | { | |
628f05b4 | 7872 | if (! e->succ_next && src != ENTRY_BLOCK_PTR) |
c9bacfdb KH |
7873 | { |
7874 | /* There are no more successors for the SRC node | |
7875 | so assign its reverse completion number. */ | |
c34d5374 MH |
7876 | if (rc_order) |
7877 | rc_order[rcnum--] = src->index; | |
c9bacfdb KH |
7878 | } |
7879 | ||
628f05b4 MH |
7880 | if (e->succ_next) |
7881 | stack[sp - 1] = e->succ_next; | |
7882 | else | |
7883 | sp--; | |
4dc9341c MH |
7884 | } |
7885 | } | |
628f05b4 | 7886 | |
4dc9341c MH |
7887 | free (stack); |
7888 | sbitmap_free (visited); | |
7889 | ||
7890 | /* The number of nodes visited should not be greater than | |
7891 | n_basic_blocks. */ | |
7892 | if (dfsnum > n_basic_blocks) | |
7893 | abort (); | |
7894 | ||
7895 | /* There are some nodes left in the CFG that are unreachable. */ | |
7896 | if (dfsnum < n_basic_blocks) | |
7897 | abort (); | |
7898 | return dfsnum; | |
7899 | } | |
7900 | ||
b53978a3 JO |
7901 | /* Compute the depth first search order on the _reverse_ graph and |
7902 | store in the array DFS_ORDER, marking the nodes visited in VISITED. | |
7903 | Returns the number of nodes visited. | |
7904 | ||
7905 | The computation is split into three pieces: | |
7906 | ||
7907 | flow_dfs_compute_reverse_init () creates the necessary data | |
7908 | structures. | |
7909 | ||
7910 | flow_dfs_compute_reverse_add_bb () adds a basic block to the data | |
7911 | structures. The block will start the search. | |
7912 | ||
7913 | flow_dfs_compute_reverse_execute () continues (or starts) the | |
7914 | search using the block on the top of the stack, stopping when the | |
7915 | stack is empty. | |
7916 | ||
7917 | flow_dfs_compute_reverse_finish () destroys the necessary data | |
7918 | structures. | |
7919 | ||
7920 | Thus, the user will probably call ..._init(), call ..._add_bb() to | |
7921 | add a beginning basic block to the stack, call ..._execute(), | |
7922 | possibly add another bb to the stack and again call ..._execute(), | |
c9bacfdb | 7923 | ..., and finally call _finish(). */ |
b53978a3 JO |
7924 | |
7925 | /* Initialize the data structures used for depth-first search on the | |
7926 | reverse graph. If INITIALIZE_STACK is nonzero, the exit block is | |
7927 | added to the basic block stack. DATA is the current depth-first | |
7928 | search context. If INITIALIZE_STACK is non-zero, there is an | |
7929 | element on the stack. */ | |
7930 | ||
7931 | static void | |
7932 | flow_dfs_compute_reverse_init (data) | |
7933 | depth_first_search_ds data; | |
7934 | { | |
7935 | /* Allocate stack for back-tracking up CFG. */ | |
7936 | data->stack = | |
c9bacfdb | 7937 | (basic_block *) xmalloc ((n_basic_blocks - (INVALID_BLOCK + 1)) |
b53978a3 JO |
7938 | * sizeof (basic_block)); |
7939 | data->sp = 0; | |
7940 | ||
7941 | /* Allocate bitmap to track nodes that have been visited. */ | |
c9bacfdb | 7942 | data->visited_blocks = sbitmap_alloc (n_basic_blocks - (INVALID_BLOCK + 1)); |
b53978a3 JO |
7943 | |
7944 | /* None of the nodes in the CFG have been visited yet. */ | |
7945 | sbitmap_zero (data->visited_blocks); | |
7946 | ||
7947 | return; | |
7948 | } | |
7949 | ||
7950 | /* Add the specified basic block to the top of the dfs data | |
7951 | structures. When the search continues, it will start at the | |
c9bacfdb | 7952 | block. */ |
b53978a3 JO |
7953 | |
7954 | static void | |
7955 | flow_dfs_compute_reverse_add_bb (data, bb) | |
7956 | depth_first_search_ds data; | |
7957 | basic_block bb; | |
7958 | { | |
7959 | data->stack[data->sp++] = bb; | |
7960 | return; | |
7961 | } | |
7962 | ||
7963 | /* Continue the depth-first search through the reverse graph starting | |
7964 | with the block at the stack's top and ending when the stack is | |
7965 | empty. Visited nodes are marked. Returns an unvisited basic | |
7966 | block, or NULL if there is none available. */ | |
c9bacfdb | 7967 | |
b53978a3 JO |
7968 | static basic_block |
7969 | flow_dfs_compute_reverse_execute (data) | |
7970 | depth_first_search_ds data; | |
7971 | { | |
7972 | basic_block bb; | |
7973 | edge e; | |
7974 | int i; | |
7975 | ||
7976 | while (data->sp > 0) | |
7977 | { | |
7978 | bb = data->stack[--data->sp]; | |
7979 | ||
c9bacfdb KH |
7980 | /* Mark that we have visited this node. */ |
7981 | if (!TEST_BIT (data->visited_blocks, bb->index - (INVALID_BLOCK + 1))) | |
b53978a3 | 7982 | { |
c9bacfdb | 7983 | SET_BIT (data->visited_blocks, bb->index - (INVALID_BLOCK + 1)); |
b53978a3 | 7984 | |
c9bacfdb | 7985 | /* Perform depth-first search on adjacent vertices. */ |
b53978a3 JO |
7986 | for (e = bb->pred; e; e = e->pred_next) |
7987 | flow_dfs_compute_reverse_add_bb (data, e->src); | |
7988 | } | |
7989 | } | |
7990 | ||
c9bacfdb KH |
7991 | /* Determine if there are unvisited basic blocks. */ |
7992 | for (i = n_basic_blocks - (INVALID_BLOCK + 1); --i >= 0;) | |
b53978a3 | 7993 | if (!TEST_BIT (data->visited_blocks, i)) |
c9bacfdb | 7994 | return BASIC_BLOCK (i + (INVALID_BLOCK + 1)); |
b53978a3 JO |
7995 | return NULL; |
7996 | } | |
7997 | ||
7998 | /* Destroy the data structures needed for depth-first search on the | |
c9bacfdb | 7999 | reverse graph. */ |
b53978a3 JO |
8000 | |
8001 | static void | |
8002 | flow_dfs_compute_reverse_finish (data) | |
8003 | depth_first_search_ds data; | |
8004 | { | |
8005 | free (data->stack); | |
8006 | sbitmap_free (data->visited_blocks); | |
8007 | return; | |
8008 | } | |
8009 | ||
5d6a16e2 MH |
8010 | |
8011 | /* Find the root node of the loop pre-header extended basic block and | |
4a7da9b5 | 8012 | the edges along the trace from the root node to the loop header. */ |
5d6a16e2 MH |
8013 | |
8014 | static void | |
8015 | flow_loop_pre_header_scan (loop) | |
8016 | struct loop *loop; | |
8017 | { | |
4a7da9b5 | 8018 | int num = 0; |
5d6a16e2 MH |
8019 | basic_block ebb; |
8020 | ||
4a7da9b5 MH |
8021 | loop->num_pre_header_edges = 0; |
8022 | ||
5d6a16e2 MH |
8023 | if (loop->num_entries != 1) |
8024 | return; | |
8025 | ||
5d6a16e2 | 8026 | ebb = loop->entry_edges[0]->src; |
ef120fc0 MH |
8027 | |
8028 | if (ebb != ENTRY_BLOCK_PTR) | |
5d6a16e2 | 8029 | { |
4a7da9b5 MH |
8030 | edge e; |
8031 | ||
8032 | /* Count number of edges along trace from loop header to | |
8033 | root of pre-header extended basic block. Usually this is | |
8034 | only one or two edges. */ | |
8035 | num++; | |
8036 | while (ebb->pred->src != ENTRY_BLOCK_PTR && ! ebb->pred->pred_next) | |
ef120fc0 MH |
8037 | { |
8038 | ebb = ebb->pred->src; | |
4a7da9b5 MH |
8039 | num++; |
8040 | } | |
8041 | ||
8042 | loop->pre_header_edges = (edge *) xmalloc (num * sizeof (edge *)); | |
8043 | loop->num_pre_header_edges = num; | |
8044 | ||
8045 | /* Store edges in order that they are followed. The source | |
8046 | of the first edge is the root node of the pre-header extended | |
8047 | basic block and the destination of the last last edge is | |
8048 | the loop header. */ | |
8049 | for (e = loop->entry_edges[0]; num; e = e->src->pred) | |
8050 | { | |
8051 | loop->pre_header_edges[--num] = e; | |
ef120fc0 | 8052 | } |
5d6a16e2 | 8053 | } |
5d6a16e2 MH |
8054 | } |
8055 | ||
8056 | ||
4dc9341c MH |
8057 | /* Return the block for the pre-header of the loop with header |
8058 | HEADER where DOM specifies the dominator information. Return NULL if | |
8059 | there is no pre-header. */ | |
c9bacfdb | 8060 | |
4dc9341c MH |
8061 | static basic_block |
8062 | flow_loop_pre_header_find (header, dom) | |
8063 | basic_block header; | |
c9bacfdb | 8064 | const sbitmap *dom; |
4dc9341c MH |
8065 | { |
8066 | basic_block pre_header; | |
8067 | edge e; | |
8068 | ||
8069 | /* If block p is a predecessor of the header and is the only block | |
8070 | that the header does not dominate, then it is the pre-header. */ | |
8071 | pre_header = NULL; | |
8072 | for (e = header->pred; e; e = e->pred_next) | |
8073 | { | |
8074 | basic_block node = e->src; | |
c9bacfdb | 8075 | |
4dc9341c MH |
8076 | if (node != ENTRY_BLOCK_PTR |
8077 | && ! TEST_BIT (dom[node->index], header->index)) | |
8078 | { | |
8079 | if (pre_header == NULL) | |
8080 | pre_header = node; | |
8081 | else | |
8082 | { | |
c9bacfdb | 8083 | /* There are multiple edges into the header from outside |
4dc9341c MH |
8084 | the loop so there is no pre-header block. */ |
8085 | pre_header = NULL; | |
8086 | break; | |
8087 | } | |
8088 | } | |
8089 | } | |
8090 | return pre_header; | |
8091 | } | |
8092 | ||
3abd3239 MH |
8093 | /* Add LOOP to the loop hierarchy tree where PREVLOOP was the loop |
8094 | previously added. The insertion algorithm assumes that the loops | |
8095 | are added in the order found by a depth first search of the CFG. */ | |
c9bacfdb | 8096 | |
4dc9341c | 8097 | static void |
3abd3239 MH |
8098 | flow_loop_tree_node_add (prevloop, loop) |
8099 | struct loop *prevloop; | |
4dc9341c MH |
8100 | struct loop *loop; |
8101 | { | |
4dc9341c | 8102 | |
3abd3239 MH |
8103 | if (flow_loop_nested_p (prevloop, loop)) |
8104 | { | |
8105 | prevloop->inner = loop; | |
8106 | loop->outer = prevloop; | |
8107 | return; | |
8108 | } | |
4dc9341c | 8109 | |
3abd3239 | 8110 | while (prevloop->outer) |
4dc9341c | 8111 | { |
3abd3239 | 8112 | if (flow_loop_nested_p (prevloop->outer, loop)) |
4dc9341c | 8113 | { |
3abd3239 MH |
8114 | prevloop->next = loop; |
8115 | loop->outer = prevloop->outer; | |
4dc9341c MH |
8116 | return; |
8117 | } | |
3abd3239 | 8118 | prevloop = prevloop->outer; |
4dc9341c | 8119 | } |
c9bacfdb | 8120 | |
3abd3239 MH |
8121 | prevloop->next = loop; |
8122 | loop->outer = NULL; | |
4dc9341c MH |
8123 | } |
8124 | ||
4dc9341c | 8125 | /* Build the loop hierarchy tree for LOOPS. */ |
c9bacfdb | 8126 | |
4dc9341c MH |
8127 | static void |
8128 | flow_loops_tree_build (loops) | |
c9bacfdb | 8129 | struct loops *loops; |
4dc9341c MH |
8130 | { |
8131 | int i; | |
8132 | int num_loops; | |
8133 | ||
8134 | num_loops = loops->num; | |
8135 | if (! num_loops) | |
8136 | return; | |
8137 | ||
8138 | /* Root the loop hierarchy tree with the first loop found. | |
c9bacfdb | 8139 | Since we used a depth first search this should be the |
4dc9341c MH |
8140 | outermost loop. */ |
8141 | loops->tree = &loops->array[0]; | |
8142 | loops->tree->outer = loops->tree->inner = loops->tree->next = NULL; | |
8143 | ||
8144 | /* Add the remaining loops to the tree. */ | |
8145 | for (i = 1; i < num_loops; i++) | |
3abd3239 | 8146 | flow_loop_tree_node_add (&loops->array[i - 1], &loops->array[i]); |
4dc9341c MH |
8147 | } |
8148 | ||
4dc9341c | 8149 | /* Helper function to compute loop nesting depth and enclosed loop level |
c9bacfdb | 8150 | for the natural loop specified by LOOP at the loop depth DEPTH. |
4dc9341c | 8151 | Returns the loop level. */ |
c9bacfdb | 8152 | |
4dc9341c MH |
8153 | static int |
8154 | flow_loop_level_compute (loop, depth) | |
8155 | struct loop *loop; | |
8156 | int depth; | |
8157 | { | |
8158 | struct loop *inner; | |
d6181b1b | 8159 | int level = 1; |
4dc9341c MH |
8160 | |
8161 | if (! loop) | |
8162 | return 0; | |
8163 | ||
8164 | /* Traverse loop tree assigning depth and computing level as the | |
8165 | maximum level of all the inner loops of this loop. The loop | |
8166 | level is equivalent to the height of the loop in the loop tree | |
d6181b1b MH |
8167 | and corresponds to the number of enclosed loop levels (including |
8168 | itself). */ | |
4dc9341c MH |
8169 | for (inner = loop->inner; inner; inner = inner->next) |
8170 | { | |
8171 | int ilevel; | |
8172 | ||
8173 | ilevel = flow_loop_level_compute (inner, depth + 1) + 1; | |
8174 | ||
8175 | if (ilevel > level) | |
8176 | level = ilevel; | |
8177 | } | |
8178 | loop->level = level; | |
8179 | loop->depth = depth; | |
8180 | return level; | |
8181 | } | |
8182 | ||
4dc9341c MH |
8183 | /* Compute the loop nesting depth and enclosed loop level for the loop |
8184 | hierarchy tree specfied by LOOPS. Return the maximum enclosed loop | |
8185 | level. */ | |
d4b60170 | 8186 | |
d6181b1b | 8187 | static int |
4dc9341c MH |
8188 | flow_loops_level_compute (loops) |
8189 | struct loops *loops; | |
8190 | { | |
d6181b1b MH |
8191 | struct loop *loop; |
8192 | int level; | |
8193 | int levels = 0; | |
8194 | ||
8195 | /* Traverse all the outer level loops. */ | |
8196 | for (loop = loops->tree; loop; loop = loop->next) | |
8197 | { | |
8198 | level = flow_loop_level_compute (loop, 1); | |
8199 | if (level > levels) | |
8200 | levels = level; | |
8201 | } | |
8202 | return levels; | |
4dc9341c MH |
8203 | } |
8204 | ||
5d6a16e2 | 8205 | |
eab02feb MH |
8206 | /* Scan a single natural loop specified by LOOP collecting information |
8207 | about it specified by FLAGS. */ | |
8208 | ||
8209 | int | |
8210 | flow_loop_scan (loops, loop, flags) | |
8211 | struct loops *loops; | |
8212 | struct loop *loop; | |
8213 | int flags; | |
8214 | { | |
8215 | /* Determine prerequisites. */ | |
8216 | if ((flags & LOOP_EXITS_DOMS) && ! loop->exit_edges) | |
8217 | flags |= LOOP_EXIT_EDGES; | |
8218 | ||
8219 | if (flags & LOOP_ENTRY_EDGES) | |
8220 | { | |
8221 | /* Find edges which enter the loop header. | |
8222 | Note that the entry edges should only | |
8223 | enter the header of a natural loop. */ | |
8224 | loop->num_entries | |
8225 | = flow_loop_entry_edges_find (loop->header, | |
8226 | loop->nodes, | |
8227 | &loop->entry_edges); | |
8228 | } | |
8229 | ||
8230 | if (flags & LOOP_EXIT_EDGES) | |
8231 | { | |
8232 | /* Find edges which exit the loop. */ | |
8233 | loop->num_exits | |
8234 | = flow_loop_exit_edges_find (loop->nodes, | |
8235 | &loop->exit_edges); | |
8236 | } | |
8237 | ||
8238 | if (flags & LOOP_EXITS_DOMS) | |
8239 | { | |
8240 | int j; | |
8241 | ||
8242 | /* Determine which loop nodes dominate all the exits | |
8243 | of the loop. */ | |
8244 | loop->exits_doms = sbitmap_alloc (n_basic_blocks); | |
8245 | sbitmap_copy (loop->exits_doms, loop->nodes); | |
8246 | for (j = 0; j < loop->num_exits; j++) | |
8247 | sbitmap_a_and_b (loop->exits_doms, loop->exits_doms, | |
8248 | loops->cfg.dom[loop->exit_edges[j]->src->index]); | |
8249 | ||
8250 | /* The header of a natural loop must dominate | |
8251 | all exits. */ | |
8252 | if (! TEST_BIT (loop->exits_doms, loop->header->index)) | |
8253 | abort (); | |
8254 | } | |
8255 | ||
8256 | if (flags & LOOP_PRE_HEADER) | |
8257 | { | |
8258 | /* Look to see if the loop has a pre-header node. */ | |
8259 | loop->pre_header | |
8260 | = flow_loop_pre_header_find (loop->header, loops->cfg.dom); | |
8261 | ||
8262 | /* Find the blocks within the extended basic block of | |
8263 | the loop pre-header. */ | |
8264 | flow_loop_pre_header_scan (loop); | |
8265 | } | |
8266 | return 1; | |
8267 | } | |
8268 | ||
8269 | ||
ce4bbac7 JH |
8270 | /* Find all the natural loops in the function and save in LOOPS structure |
8271 | and recalculate loop_depth information in basic block structures. | |
5d6a16e2 | 8272 | FLAGS controls which loop information is collected. |
4dc9341c | 8273 | Return the number of natural loops found. */ |
d4b60170 | 8274 | |
c9bacfdb | 8275 | int |
5d6a16e2 | 8276 | flow_loops_find (loops, flags) |
c9bacfdb | 8277 | struct loops *loops; |
5d6a16e2 | 8278 | int flags; |
4dc9341c MH |
8279 | { |
8280 | int i; | |
8281 | int b; | |
8282 | int num_loops; | |
8283 | edge e; | |
8284 | sbitmap headers; | |
8285 | sbitmap *dom; | |
8286 | int *dfs_order; | |
c34d5374 | 8287 | int *rc_order; |
c9bacfdb | 8288 | |
5d6a16e2 MH |
8289 | /* This function cannot be repeatedly called with different |
8290 | flags to build up the loop information. The loop tree | |
8291 | must always be built if this function is called. */ | |
8292 | if (! (flags & LOOP_TREE)) | |
8293 | abort (); | |
21c7361e | 8294 | |
5d6a16e2 | 8295 | memset (loops, 0, sizeof (*loops)); |
4dc9341c MH |
8296 | |
8297 | /* Taking care of this degenerate case makes the rest of | |
8298 | this code simpler. */ | |
8299 | if (n_basic_blocks == 0) | |
8300 | return 0; | |
8301 | ||
5d6a16e2 MH |
8302 | dfs_order = NULL; |
8303 | rc_order = NULL; | |
8304 | ||
4dc9341c MH |
8305 | /* Compute the dominators. */ |
8306 | dom = sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks); | |
f8032688 | 8307 | calculate_dominance_info (NULL, dom, CDI_DOMINATORS); |
4dc9341c MH |
8308 | |
8309 | /* Count the number of loop edges (back edges). This should be the | |
5d6a16e2 | 8310 | same as the number of natural loops. */ |
ce4bbac7 | 8311 | |
4dc9341c MH |
8312 | num_loops = 0; |
8313 | for (b = 0; b < n_basic_blocks; b++) | |
8314 | { | |
5d6a16e2 MH |
8315 | basic_block header; |
8316 | ||
8317 | header = BASIC_BLOCK (b); | |
8318 | header->loop_depth = 0; | |
8319 | ||
8320 | for (e = header->pred; e; e = e->pred_next) | |
4dc9341c MH |
8321 | { |
8322 | basic_block latch = e->src; | |
c9bacfdb | 8323 | |
4dc9341c MH |
8324 | /* Look for back edges where a predecessor is dominated |
8325 | by this block. A natural loop has a single entry | |
8326 | node (header) that dominates all the nodes in the | |
8327 | loop. It also has single back edge to the header | |
8328 | from a latch node. Note that multiple natural loops | |
8329 | may share the same header. */ | |
5d6a16e2 MH |
8330 | if (b != header->index) |
8331 | abort (); | |
8332 | ||
4dc9341c MH |
8333 | if (latch != ENTRY_BLOCK_PTR && TEST_BIT (dom[latch->index], b)) |
8334 | num_loops++; | |
8335 | } | |
8336 | } | |
c9bacfdb | 8337 | |
4dc9341c MH |
8338 | if (num_loops) |
8339 | { | |
8340 | /* Compute depth first search order of the CFG so that outer | |
8341 | natural loops will be found before inner natural loops. */ | |
8342 | dfs_order = (int *) xmalloc (n_basic_blocks * sizeof (int)); | |
c34d5374 MH |
8343 | rc_order = (int *) xmalloc (n_basic_blocks * sizeof (int)); |
8344 | flow_depth_first_order_compute (dfs_order, rc_order); | |
4dc9341c | 8345 | |
eab02feb MH |
8346 | /* Save CFG derived information to avoid recomputing it. */ |
8347 | loops->cfg.dom = dom; | |
8348 | loops->cfg.dfs_order = dfs_order; | |
8349 | loops->cfg.rc_order = rc_order; | |
8350 | ||
4dc9341c | 8351 | /* Allocate loop structures. */ |
d4b60170 RK |
8352 | loops->array |
8353 | = (struct loop *) xcalloc (num_loops, sizeof (struct loop)); | |
c9bacfdb | 8354 | |
4dc9341c MH |
8355 | headers = sbitmap_alloc (n_basic_blocks); |
8356 | sbitmap_zero (headers); | |
8357 | ||
8358 | loops->shared_headers = sbitmap_alloc (n_basic_blocks); | |
8359 | sbitmap_zero (loops->shared_headers); | |
8360 | ||
8361 | /* Find and record information about all the natural loops | |
8362 | in the CFG. */ | |
8363 | num_loops = 0; | |
8364 | for (b = 0; b < n_basic_blocks; b++) | |
8365 | { | |
8366 | basic_block header; | |
8367 | ||
5d6a16e2 MH |
8368 | /* Search the nodes of the CFG in reverse completion order |
8369 | so that we can find outer loops first. */ | |
c34d5374 | 8370 | header = BASIC_BLOCK (rc_order[b]); |
c9bacfdb | 8371 | |
4dc9341c MH |
8372 | /* Look for all the possible latch blocks for this header. */ |
8373 | for (e = header->pred; e; e = e->pred_next) | |
8374 | { | |
8375 | basic_block latch = e->src; | |
c9bacfdb | 8376 | |
4dc9341c MH |
8377 | /* Look for back edges where a predecessor is dominated |
8378 | by this block. A natural loop has a single entry | |
8379 | node (header) that dominates all the nodes in the | |
8380 | loop. It also has single back edge to the header | |
8381 | from a latch node. Note that multiple natural loops | |
8382 | may share the same header. */ | |
8383 | if (latch != ENTRY_BLOCK_PTR | |
8384 | && TEST_BIT (dom[latch->index], header->index)) | |
8385 | { | |
8386 | struct loop *loop; | |
c9bacfdb | 8387 | |
4dc9341c | 8388 | loop = loops->array + num_loops; |
c9bacfdb | 8389 | |
4dc9341c MH |
8390 | loop->header = header; |
8391 | loop->latch = latch; | |
c34d5374 | 8392 | loop->num = num_loops; |
c9bacfdb | 8393 | |
4dc9341c MH |
8394 | num_loops++; |
8395 | } | |
8396 | } | |
8397 | } | |
c9bacfdb | 8398 | |
5d6a16e2 MH |
8399 | for (i = 0; i < num_loops; i++) |
8400 | { | |
8401 | struct loop *loop = &loops->array[i]; | |
5d6a16e2 MH |
8402 | |
8403 | /* Keep track of blocks that are loop headers so | |
8404 | that we can tell which loops should be merged. */ | |
8405 | if (TEST_BIT (headers, loop->header->index)) | |
8406 | SET_BIT (loops->shared_headers, loop->header->index); | |
8407 | SET_BIT (headers, loop->header->index); | |
8408 | ||
8409 | /* Find nodes contained within the loop. */ | |
8410 | loop->nodes = sbitmap_alloc (n_basic_blocks); | |
8411 | loop->num_nodes | |
8412 | = flow_loop_nodes_find (loop->header, loop->latch, loop->nodes); | |
21c7361e | 8413 | |
5d6a16e2 MH |
8414 | /* Compute first and last blocks within the loop. |
8415 | These are often the same as the loop header and | |
8416 | loop latch respectively, but this is not always | |
8417 | the case. */ | |
8418 | loop->first | |
8419 | = BASIC_BLOCK (sbitmap_first_set_bit (loop->nodes)); | |
8420 | loop->last | |
8421 | = BASIC_BLOCK (sbitmap_last_set_bit (loop->nodes)); | |
21c7361e | 8422 | |
eab02feb | 8423 | flow_loop_scan (loops, loop, flags); |
5d6a16e2 MH |
8424 | } |
8425 | ||
4dc9341c MH |
8426 | /* Natural loops with shared headers may either be disjoint or |
8427 | nested. Disjoint loops with shared headers cannot be inner | |
8428 | loops and should be merged. For now just mark loops that share | |
8429 | headers. */ | |
8430 | for (i = 0; i < num_loops; i++) | |
8431 | if (TEST_BIT (loops->shared_headers, loops->array[i].header->index)) | |
8432 | loops->array[i].shared = 1; | |
8433 | ||
8434 | sbitmap_free (headers); | |
8435 | } | |
8436 | ||
8437 | loops->num = num_loops; | |
8438 | ||
4dc9341c MH |
8439 | /* Build the loop hierarchy tree. */ |
8440 | flow_loops_tree_build (loops); | |
8441 | ||
8442 | /* Assign the loop nesting depth and enclosed loop level for each | |
8443 | loop. */ | |
d6181b1b | 8444 | loops->levels = flow_loops_level_compute (loops); |
4dc9341c MH |
8445 | |
8446 | return num_loops; | |
8447 | } | |
8448 | ||
5d6a16e2 MH |
8449 | |
8450 | /* Update the information regarding the loops in the CFG | |
8451 | specified by LOOPS. */ | |
8452 | int | |
8453 | flow_loops_update (loops, flags) | |
8454 | struct loops *loops; | |
8455 | int flags; | |
8456 | { | |
8457 | /* One day we may want to update the current loop data. For now | |
8458 | throw away the old stuff and rebuild what we need. */ | |
8459 | if (loops->array) | |
8460 | flow_loops_free (loops); | |
21c7361e | 8461 | |
5d6a16e2 MH |
8462 | return flow_loops_find (loops, flags); |
8463 | } | |
8464 | ||
8465 | ||
4dc9341c | 8466 | /* Return non-zero if edge E enters header of LOOP from outside of LOOP. */ |
efc9bd41 | 8467 | |
4dc9341c MH |
8468 | int |
8469 | flow_loop_outside_edge_p (loop, e) | |
8470 | const struct loop *loop; | |
8471 | edge e; | |
8472 | { | |
8473 | if (e->dest != loop->header) | |
8474 | abort (); | |
8475 | return (e->src == ENTRY_BLOCK_PTR) | |
8476 | || ! TEST_BIT (loop->nodes, e->src->index); | |
8477 | } | |
11bdd2ae | 8478 | |
c9bacfdb | 8479 | /* Clear LOG_LINKS fields of insns in a chain. |
1868b439 GK |
8480 | Also clear the global_live_at_{start,end} fields of the basic block |
8481 | structures. */ | |
efc9bd41 | 8482 | |
d9d4fb43 AS |
8483 | void |
8484 | clear_log_links (insns) | |
8485 | rtx insns; | |
8486 | { | |
8487 | rtx i; | |
1868b439 GK |
8488 | int b; |
8489 | ||
d9d4fb43 | 8490 | for (i = insns; i; i = NEXT_INSN (i)) |
2c3c49de | 8491 | if (INSN_P (i)) |
d9d4fb43 | 8492 | LOG_LINKS (i) = 0; |
1868b439 GK |
8493 | |
8494 | for (b = 0; b < n_basic_blocks; b++) | |
8495 | { | |
da92f7ff | 8496 | basic_block bb = BASIC_BLOCK (b); |
1868b439 GK |
8497 | |
8498 | bb->global_live_at_start = NULL; | |
8499 | bb->global_live_at_end = NULL; | |
8500 | } | |
8501 | ||
8502 | ENTRY_BLOCK_PTR->global_live_at_end = NULL; | |
8503 | EXIT_BLOCK_PTR->global_live_at_start = NULL; | |
d9d4fb43 | 8504 | } |
efc9bd41 RK |
8505 | |
8506 | /* Given a register bitmap, turn on the bits in a HARD_REG_SET that | |
8507 | correspond to the hard registers, if any, set in that map. This | |
8508 | could be done far more efficiently by having all sorts of special-cases | |
8509 | with moving single words, but probably isn't worth the trouble. */ | |
8510 | ||
8511 | void | |
8512 | reg_set_to_hard_reg_set (to, from) | |
8513 | HARD_REG_SET *to; | |
8514 | bitmap from; | |
8515 | { | |
8516 | int i; | |
8517 | ||
8518 | EXECUTE_IF_SET_IN_BITMAP | |
8519 | (from, 0, i, | |
8520 | { | |
8521 | if (i >= FIRST_PSEUDO_REGISTER) | |
8522 | return; | |
8523 | SET_HARD_REG_BIT (*to, i); | |
8524 | }); | |
8525 | } | |
1f8f4a0b MM |
8526 | |
8527 | /* Called once at intialization time. */ | |
8528 | ||
8529 | void | |
8530 | init_flow () | |
8531 | { | |
8532 | static int initialized; | |
8533 | ||
8534 | if (!initialized) | |
8535 | { | |
8536 | gcc_obstack_init (&flow_obstack); | |
8537 | flow_firstobj = (char *) obstack_alloc (&flow_obstack, 0); | |
8538 | initialized = 1; | |
8539 | } | |
8540 | else | |
8541 | { | |
8542 | obstack_free (&flow_obstack, flow_firstobj); | |
8543 | flow_firstobj = (char *) obstack_alloc (&flow_obstack, 0); | |
8544 | } | |
8545 | } |