]>
Commit | Line | Data |
---|---|---|
d7429b6a | 1 | /* Data flow analysis for GNU compiler. |
c9bacfdb | 2 | Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, |
3b708058 | 3 | 1999, 2000 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" |
e881bb1b | 136 | #include "insn-flags.h" |
11bdd2ae | 137 | #include "expr.h" |
b53978a3 | 138 | #include "ssa.h" |
d7429b6a RK |
139 | |
140 | #include "obstack.h" | |
11ae508b | 141 | #include "splay-tree.h" |
c5c76735 | 142 | |
d7429b6a RK |
143 | #define obstack_chunk_alloc xmalloc |
144 | #define obstack_chunk_free free | |
145 | ||
e881bb1b RH |
146 | /* EXIT_IGNORE_STACK should be nonzero if, when returning from a function, |
147 | the stack pointer does not matter. The value is tested only in | |
148 | functions that have frame pointers. | |
149 | No definition is equivalent to always zero. */ | |
150 | #ifndef EXIT_IGNORE_STACK | |
151 | #define EXIT_IGNORE_STACK 0 | |
152 | #endif | |
153 | ||
d3a923ee RH |
154 | #ifndef HAVE_epilogue |
155 | #define HAVE_epilogue 0 | |
156 | #endif | |
d3a923ee RH |
157 | #ifndef HAVE_prologue |
158 | #define HAVE_prologue 0 | |
159 | #endif | |
0a1c58a2 JL |
160 | #ifndef HAVE_sibcall_epilogue |
161 | #define HAVE_sibcall_epilogue 0 | |
162 | #endif | |
d3a923ee | 163 | |
2a3e384f RH |
164 | #ifndef LOCAL_REGNO |
165 | #define LOCAL_REGNO(REGNO) 0 | |
166 | #endif | |
167 | #ifndef EPILOGUE_USES | |
168 | #define EPILOGUE_USES(REGNO) 0 | |
169 | #endif | |
170 | ||
1f8f4a0b | 171 | /* The obstack on which the flow graph components are allocated. */ |
7eb136d6 | 172 | |
1f8f4a0b MM |
173 | struct obstack flow_obstack; |
174 | static char *flow_firstobj; | |
7eb136d6 | 175 | |
e881bb1b | 176 | /* Number of basic blocks in the current function. */ |
d7429b6a | 177 | |
e881bb1b | 178 | int n_basic_blocks; |
d7429b6a | 179 | |
d3a923ee RH |
180 | /* Number of edges in the current function. */ |
181 | ||
182 | int n_edges; | |
183 | ||
e881bb1b | 184 | /* The basic block array. */ |
d7429b6a | 185 | |
e881bb1b | 186 | varray_type basic_block_info; |
d7429b6a | 187 | |
e881bb1b | 188 | /* The special entry and exit blocks. */ |
d7429b6a | 189 | |
d4b60170 RK |
190 | struct basic_block_def entry_exit_blocks[2] |
191 | = {{NULL, /* head */ | |
e881bb1b RH |
192 | NULL, /* end */ |
193 | NULL, /* pred */ | |
194 | NULL, /* succ */ | |
195 | NULL, /* local_set */ | |
7dfc0fbe | 196 | NULL, /* cond_local_set */ |
e881bb1b RH |
197 | NULL, /* global_live_at_start */ |
198 | NULL, /* global_live_at_end */ | |
199 | NULL, /* aux */ | |
200 | ENTRY_BLOCK, /* index */ | |
336a6399 | 201 | 0, /* loop_depth */ |
51891abe JH |
202 | -1, -1, /* eh_beg, eh_end */ |
203 | 0 /* count */ | |
e881bb1b RH |
204 | }, |
205 | { | |
206 | NULL, /* head */ | |
207 | NULL, /* end */ | |
208 | NULL, /* pred */ | |
209 | NULL, /* succ */ | |
210 | NULL, /* local_set */ | |
7dfc0fbe | 211 | NULL, /* cond_local_set */ |
e881bb1b RH |
212 | NULL, /* global_live_at_start */ |
213 | NULL, /* global_live_at_end */ | |
214 | NULL, /* aux */ | |
215 | EXIT_BLOCK, /* index */ | |
336a6399 | 216 | 0, /* loop_depth */ |
51891abe JH |
217 | -1, -1, /* eh_beg, eh_end */ |
218 | 0 /* count */ | |
e881bb1b RH |
219 | } |
220 | }; | |
d7429b6a | 221 | |
56744d1a JL |
222 | /* Nonzero if the second flow pass has completed. */ |
223 | int flow2_completed; | |
224 | ||
d7429b6a RK |
225 | /* Maximum register number used in this function, plus one. */ |
226 | ||
227 | int max_regno; | |
228 | ||
b1f21e0a | 229 | /* Indexed by n, giving various register information */ |
d7429b6a | 230 | |
6feacd09 | 231 | varray_type reg_n_info; |
d7429b6a | 232 | |
d7429b6a RK |
233 | /* Size of a regset for the current function, |
234 | in (1) bytes and (2) elements. */ | |
235 | ||
236 | int regset_bytes; | |
237 | int regset_size; | |
238 | ||
d7429b6a | 239 | /* Regset of regs live when calls to `setjmp'-like functions happen. */ |
e881bb1b | 240 | /* ??? Does this exist only for the setjmp-clobbered warning message? */ |
d7429b6a RK |
241 | |
242 | regset regs_live_at_setjmp; | |
243 | ||
244 | /* List made of EXPR_LIST rtx's which gives pairs of pseudo registers | |
245 | that have to go in the same hard reg. | |
246 | The first two regs in the list are a pair, and the next two | |
247 | are another pair, etc. */ | |
248 | rtx regs_may_share; | |
249 | ||
d7429b6a RK |
250 | /* Set of registers that may be eliminable. These are handled specially |
251 | in updating regs_ever_live. */ | |
252 | ||
253 | static HARD_REG_SET elim_reg_set; | |
254 | ||
e881bb1b RH |
255 | /* The basic block structure for every insn, indexed by uid. */ |
256 | ||
257 | varray_type basic_block_for_insn; | |
258 | ||
259 | /* The labels mentioned in non-jump rtl. Valid during find_basic_blocks. */ | |
c9bacfdb | 260 | /* ??? Should probably be using LABEL_NUSES instead. It would take a |
e881bb1b RH |
261 | bit of surgery to be able to use or co-opt the routines in jump. */ |
262 | ||
263 | static rtx label_value_list; | |
be1bb652 | 264 | static rtx tail_recursion_label_list; |
e881bb1b | 265 | |
11ae508b RH |
266 | /* Holds information for tracking conditional register life information. */ |
267 | struct reg_cond_life_info | |
268 | { | |
269 | /* An EXPR_LIST of conditions under which a register is dead. */ | |
270 | rtx condition; | |
271 | ||
272 | /* ??? Could store mask of bytes that are dead, so that we could finally | |
273 | track lifetimes of multi-word registers accessed via subregs. */ | |
274 | }; | |
275 | ||
62828c00 RH |
276 | /* For use in communicating between propagate_block and its subroutines. |
277 | Holds all information needed to compute life and def-use information. */ | |
278 | ||
279 | struct propagate_block_info | |
280 | { | |
281 | /* The basic block we're considering. */ | |
282 | basic_block bb; | |
283 | ||
284 | /* Bit N is set if register N is conditionally or unconditionally live. */ | |
285 | regset reg_live; | |
286 | ||
9785c68d RH |
287 | /* Bit N is set if register N is set this insn. */ |
288 | regset new_set; | |
8e3f9094 | 289 | |
62828c00 RH |
290 | /* Element N is the next insn that uses (hard or pseudo) register N |
291 | within the current basic block; or zero, if there is no such insn. */ | |
292 | rtx *reg_next_use; | |
293 | ||
294 | /* Contains a list of all the MEMs we are tracking for dead store | |
295 | elimination. */ | |
296 | rtx mem_set_list; | |
297 | ||
7dfc0fbe BS |
298 | /* If non-null, record the set of registers set unconditionally in the |
299 | basic block. */ | |
62828c00 RH |
300 | regset local_set; |
301 | ||
7dfc0fbe BS |
302 | /* If non-null, record the set of registers set conditionally in the |
303 | basic block. */ | |
304 | regset cond_local_set; | |
305 | ||
11ae508b RH |
306 | #ifdef HAVE_conditional_execution |
307 | /* Indexed by register number, holds a reg_cond_life_info for each | |
308 | register that is not unconditionally live or dead. */ | |
309 | splay_tree reg_cond_dead; | |
310 | ||
311 | /* Bit N is set if register N is in an expression in reg_cond_dead. */ | |
312 | regset reg_cond_reg; | |
313 | #endif | |
314 | ||
62828c00 RH |
315 | /* Non-zero if the value of CC0 is live. */ |
316 | int cc0_live; | |
317 | ||
318 | /* Flags controling the set of information propagate_block collects. */ | |
319 | int flags; | |
320 | }; | |
321 | ||
c9bacfdb | 322 | /* Store the data structures necessary for depth-first search. */ |
b53978a3 JO |
323 | struct depth_first_search_dsS { |
324 | /* stack for backtracking during the algorithm */ | |
325 | basic_block *stack; | |
326 | ||
327 | /* number of edges in the stack. That is, positions 0, ..., sp-1 | |
c9bacfdb | 328 | have edges. */ |
b53978a3 JO |
329 | unsigned int sp; |
330 | ||
331 | /* record of basic blocks already seen by depth-first search */ | |
332 | sbitmap visited_blocks; | |
333 | }; | |
334 | typedef struct depth_first_search_dsS *depth_first_search_ds; | |
335 | ||
d7429b6a | 336 | /* Forward declarations */ |
711d877c | 337 | static int count_basic_blocks PARAMS ((rtx)); |
be1bb652 | 338 | static void find_basic_blocks_1 PARAMS ((rtx)); |
1bc48f82 | 339 | static rtx find_label_refs PARAMS ((rtx, rtx)); |
711d877c KG |
340 | static void clear_edges PARAMS ((void)); |
341 | static void make_edges PARAMS ((rtx)); | |
711d877c KG |
342 | static void make_label_edge PARAMS ((sbitmap *, basic_block, |
343 | rtx, int)); | |
344 | static void make_eh_edge PARAMS ((sbitmap *, eh_nesting_info *, | |
345 | basic_block, rtx, int)); | |
346 | static void mark_critical_edges PARAMS ((void)); | |
347 | static void move_stray_eh_region_notes PARAMS ((void)); | |
348 | static void record_active_eh_regions PARAMS ((rtx)); | |
349 | ||
350 | static void commit_one_edge_insertion PARAMS ((edge)); | |
351 | ||
352 | static void delete_unreachable_blocks PARAMS ((void)); | |
353 | static void delete_eh_regions PARAMS ((void)); | |
354 | static int can_delete_note_p PARAMS ((rtx)); | |
711d877c | 355 | static void expunge_block PARAMS ((basic_block)); |
711d877c | 356 | static int can_delete_label_p PARAMS ((rtx)); |
be1bb652 | 357 | static int tail_recursion_label_p PARAMS ((rtx)); |
711d877c KG |
358 | static int merge_blocks_move_predecessor_nojumps PARAMS ((basic_block, |
359 | basic_block)); | |
360 | static int merge_blocks_move_successor_nojumps PARAMS ((basic_block, | |
336a6399 | 361 | basic_block)); |
711d877c KG |
362 | static int merge_blocks PARAMS ((edge,basic_block,basic_block)); |
363 | static void try_merge_blocks PARAMS ((void)); | |
5568fb48 | 364 | static void tidy_fallthru_edges PARAMS ((void)); |
711d877c KG |
365 | static int verify_wide_reg_1 PARAMS ((rtx *, void *)); |
366 | static void verify_wide_reg PARAMS ((int, rtx, rtx)); | |
367 | static void verify_local_live_at_start PARAMS ((regset, basic_block)); | |
368 | static int set_noop_p PARAMS ((rtx)); | |
369 | static int noop_move_p PARAMS ((rtx)); | |
3ea8083f JL |
370 | static void delete_noop_moves PARAMS ((rtx)); |
371 | static void notice_stack_pointer_modification_1 PARAMS ((rtx, rtx, void *)); | |
372 | static void notice_stack_pointer_modification PARAMS ((rtx)); | |
c13fde05 | 373 | static void mark_reg PARAMS ((rtx, void *)); |
711d877c | 374 | static void mark_regs_live_at_end PARAMS ((regset)); |
4e872036 | 375 | static int set_phi_alternative_reg PARAMS ((rtx, int, int, void *)); |
711d877c | 376 | static void calculate_global_regs_live PARAMS ((sbitmap, sbitmap, int)); |
62828c00 RH |
377 | static void propagate_block_delete_insn PARAMS ((basic_block, rtx)); |
378 | static rtx propagate_block_delete_libcall PARAMS ((basic_block, rtx, rtx)); | |
62828c00 RH |
379 | static int insn_dead_p PARAMS ((struct propagate_block_info *, |
380 | rtx, int, rtx)); | |
381 | static int libcall_dead_p PARAMS ((struct propagate_block_info *, | |
01fbc97d | 382 | rtx, rtx)); |
62828c00 | 383 | static void mark_set_regs PARAMS ((struct propagate_block_info *, |
8e3f9094 | 384 | rtx, rtx)); |
62828c00 | 385 | static void mark_set_1 PARAMS ((struct propagate_block_info *, |
b4593d17 RH |
386 | enum rtx_code, rtx, rtx, |
387 | rtx, int)); | |
11ae508b RH |
388 | #ifdef HAVE_conditional_execution |
389 | static int mark_regno_cond_dead PARAMS ((struct propagate_block_info *, | |
390 | int, rtx)); | |
391 | static void free_reg_cond_life_info PARAMS ((splay_tree_value)); | |
392 | static int flush_reg_cond_reg_1 PARAMS ((splay_tree_node, void *)); | |
393 | static void flush_reg_cond_reg PARAMS ((struct propagate_block_info *, | |
394 | int)); | |
395 | static rtx ior_reg_cond PARAMS ((rtx, rtx)); | |
396 | static rtx not_reg_cond PARAMS ((rtx)); | |
397 | static rtx nand_reg_cond PARAMS ((rtx, rtx)); | |
398 | #endif | |
1d300e19 | 399 | #ifdef AUTO_INC_DEC |
4b983fdc RH |
400 | static void attempt_auto_inc PARAMS ((struct propagate_block_info *, |
401 | rtx, rtx, rtx, rtx, rtx)); | |
62828c00 RH |
402 | static void find_auto_inc PARAMS ((struct propagate_block_info *, |
403 | rtx, rtx)); | |
404 | static int try_pre_increment_1 PARAMS ((struct propagate_block_info *, | |
405 | rtx)); | |
711d877c | 406 | static int try_pre_increment PARAMS ((rtx, rtx, HOST_WIDE_INT)); |
1d300e19 | 407 | #endif |
62828c00 | 408 | static void mark_used_reg PARAMS ((struct propagate_block_info *, |
8e3f9094 | 409 | rtx, rtx, rtx)); |
62828c00 | 410 | static void mark_used_regs PARAMS ((struct propagate_block_info *, |
8e3f9094 | 411 | rtx, rtx, rtx)); |
711d877c KG |
412 | void dump_flow_info PARAMS ((FILE *)); |
413 | void debug_flow_info PARAMS ((void)); | |
414 | static void dump_edge_info PARAMS ((FILE *, edge, int)); | |
f9b697bf | 415 | static void print_rtl_and_abort PARAMS ((void)); |
711d877c | 416 | |
62828c00 RH |
417 | static void invalidate_mems_from_autoinc PARAMS ((struct propagate_block_info *, |
418 | rtx)); | |
1288c070 RH |
419 | static void invalidate_mems_from_set PARAMS ((struct propagate_block_info *, |
420 | rtx)); | |
711d877c | 421 | static void remove_fake_successors PARAMS ((basic_block)); |
135ebc36 MH |
422 | static void flow_nodes_print PARAMS ((const char *, const sbitmap, |
423 | FILE *)); | |
424 | static void flow_edge_list_print PARAMS ((const char *, const edge *, | |
425 | int, FILE *)); | |
426 | static void flow_loops_cfg_dump PARAMS ((const struct loops *, | |
427 | FILE *)); | |
428 | static int flow_loop_nested_p PARAMS ((struct loop *, | |
429 | struct loop *)); | |
430 | static int flow_loop_entry_edges_find PARAMS ((basic_block, const sbitmap, | |
431 | edge **)); | |
432 | static int flow_loop_exit_edges_find PARAMS ((const sbitmap, edge **)); | |
711d877c | 433 | static int flow_loop_nodes_find PARAMS ((basic_block, basic_block, sbitmap)); |
c34d5374 | 434 | static int flow_depth_first_order_compute PARAMS ((int *, int *)); |
b53978a3 JO |
435 | static void flow_dfs_compute_reverse_init |
436 | PARAMS ((depth_first_search_ds)); | |
437 | static void flow_dfs_compute_reverse_add_bb | |
438 | PARAMS ((depth_first_search_ds, basic_block)); | |
439 | static basic_block flow_dfs_compute_reverse_execute | |
440 | PARAMS ((depth_first_search_ds)); | |
441 | static void flow_dfs_compute_reverse_finish | |
442 | PARAMS ((depth_first_search_ds)); | |
5d6a16e2 MH |
443 | static void flow_loop_pre_header_scan PARAMS ((struct loop *)); |
444 | static basic_block flow_loop_pre_header_find PARAMS ((basic_block, | |
445 | const sbitmap *)); | |
711d877c KG |
446 | static void flow_loop_tree_node_add PARAMS ((struct loop *, struct loop *)); |
447 | static void flow_loops_tree_build PARAMS ((struct loops *)); | |
448 | static int flow_loop_level_compute PARAMS ((struct loop *, int)); | |
449 | static int flow_loops_level_compute PARAMS ((struct loops *)); | |
1f8f4a0b | 450 | static void allocate_bb_life_data PARAMS ((void)); |
d7429b6a | 451 | \f |
5ece9746 | 452 | /* Find basic blocks of the current function. |
e881bb1b RH |
453 | F is the first insn of the function and NREGS the number of register |
454 | numbers in use. */ | |
d7429b6a RK |
455 | |
456 | void | |
19d3c25c | 457 | find_basic_blocks (f, nregs, file) |
d7429b6a | 458 | rtx f; |
e881bb1b RH |
459 | int nregs ATTRIBUTE_UNUSED; |
460 | FILE *file ATTRIBUTE_UNUSED; | |
d7429b6a | 461 | { |
e881bb1b | 462 | int max_uid; |
d7429b6a | 463 | |
e881bb1b RH |
464 | /* Flush out existing data. */ |
465 | if (basic_block_info != NULL) | |
466 | { | |
467 | int i; | |
421382ac | 468 | |
e881bb1b | 469 | clear_edges (); |
d7429b6a | 470 | |
c9bacfdb | 471 | /* Clear bb->aux on all extant basic blocks. We'll use this as a |
e881bb1b RH |
472 | tag for reuse during create_basic_block, just in case some pass |
473 | copies around basic block notes improperly. */ | |
474 | for (i = 0; i < n_basic_blocks; ++i) | |
475 | BASIC_BLOCK (i)->aux = NULL; | |
d7429b6a | 476 | |
e881bb1b RH |
477 | VARRAY_FREE (basic_block_info); |
478 | } | |
27249135 | 479 | |
e881bb1b | 480 | n_basic_blocks = count_basic_blocks (f); |
27249135 | 481 | |
e881bb1b RH |
482 | /* Size the basic block table. The actual structures will be allocated |
483 | by find_basic_blocks_1, since we want to keep the structure pointers | |
484 | stable across calls to find_basic_blocks. */ | |
485 | /* ??? This whole issue would be much simpler if we called find_basic_blocks | |
c9bacfdb | 486 | exactly once, and thereafter we don't have a single long chain of |
e881bb1b RH |
487 | instructions at all until close to the end of compilation when we |
488 | actually lay them out. */ | |
8cfe18d6 | 489 | |
e881bb1b RH |
490 | VARRAY_BB_INIT (basic_block_info, n_basic_blocks, "basic_block_info"); |
491 | ||
be1bb652 | 492 | find_basic_blocks_1 (f); |
c9bacfdb | 493 | |
e881bb1b RH |
494 | /* Record the block to which an insn belongs. */ |
495 | /* ??? This should be done another way, by which (perhaps) a label is | |
496 | tagged directly with the basic block that it starts. It is used for | |
497 | more than that currently, but IMO that is the only valid use. */ | |
498 | ||
499 | max_uid = get_max_uid (); | |
d7429b6a | 500 | #ifdef AUTO_INC_DEC |
5ece9746 JL |
501 | /* Leave space for insns life_analysis makes in some cases for auto-inc. |
502 | These cases are rare, so we don't need too much space. */ | |
e881bb1b | 503 | max_uid += max_uid / 10; |
d7429b6a RK |
504 | #endif |
505 | ||
2307e372 | 506 | compute_bb_for_insn (max_uid); |
e881bb1b RH |
507 | |
508 | /* Discover the edges of our cfg. */ | |
336a6399 RH |
509 | record_active_eh_regions (f); |
510 | make_edges (label_value_list); | |
5568fb48 RH |
511 | |
512 | /* Do very simple cleanup now, for the benefit of code that runs between | |
513 | here and cleanup_cfg, e.g. thread_prologue_and_epilogue_insns. */ | |
514 | tidy_fallthru_edges (); | |
515 | ||
e881bb1b RH |
516 | mark_critical_edges (); |
517 | ||
34487bf8 RH |
518 | #ifdef ENABLE_CHECKING |
519 | verify_flow_info (); | |
520 | #endif | |
d7429b6a | 521 | } |
5ece9746 | 522 | |
b313a0fe RH |
523 | void |
524 | check_function_return_warnings () | |
525 | { | |
526 | if (warn_missing_noreturn | |
527 | && !TREE_THIS_VOLATILE (cfun->decl) | |
528 | && EXIT_BLOCK_PTR->pred == NULL) | |
529 | warning ("function might be possible candidate for attribute `noreturn'"); | |
530 | ||
531 | /* If we have a path to EXIT, then we do return. */ | |
532 | if (TREE_THIS_VOLATILE (cfun->decl) | |
533 | && EXIT_BLOCK_PTR->pred != NULL) | |
534 | warning ("`noreturn' function does return"); | |
535 | ||
536 | /* If the clobber_return_insn appears in some basic block, then we | |
537 | do reach the end without returning a value. */ | |
538 | else if (warn_return_type | |
539 | && cfun->x_clobber_return_insn != NULL | |
540 | && EXIT_BLOCK_PTR->pred != NULL) | |
541 | { | |
542 | int max_uid = get_max_uid (); | |
543 | ||
544 | /* If clobber_return_insn was excised by jump1, then renumber_insns | |
545 | can make max_uid smaller than the number still recorded in our rtx. | |
546 | That's fine, since this is a quick way of verifying that the insn | |
547 | is no longer in the chain. */ | |
548 | if (INSN_UID (cfun->x_clobber_return_insn) < max_uid) | |
549 | { | |
550 | /* Recompute insn->block mapping, since the initial mapping is | |
551 | set before we delete unreachable blocks. */ | |
552 | compute_bb_for_insn (max_uid); | |
553 | ||
554 | if (BLOCK_FOR_INSN (cfun->x_clobber_return_insn) != NULL) | |
555 | warning ("control reaches end of non-void function"); | |
556 | } | |
557 | } | |
558 | } | |
559 | ||
e881bb1b | 560 | /* Count the basic blocks of the function. */ |
dc2ede84 | 561 | |
c9bacfdb | 562 | static int |
e881bb1b RH |
563 | count_basic_blocks (f) |
564 | rtx f; | |
565 | { | |
566 | register rtx insn; | |
567 | register RTX_CODE prev_code; | |
568 | register int count = 0; | |
569 | int eh_region = 0; | |
e881bb1b | 570 | int call_had_abnormal_edge = 0; |
dc2ede84 | 571 | |
e881bb1b RH |
572 | prev_code = JUMP_INSN; |
573 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
574 | { | |
575 | register RTX_CODE code = GET_CODE (insn); | |
576 | ||
e881bb1b RH |
577 | if (code == CODE_LABEL |
578 | || (GET_RTX_CLASS (code) == 'i' | |
579 | && (prev_code == JUMP_INSN | |
580 | || prev_code == BARRIER | |
c29ea88a | 581 | || (prev_code == CALL_INSN && call_had_abnormal_edge)))) |
314883b8 RK |
582 | count++; |
583 | ||
e881bb1b RH |
584 | /* Record whether this call created an edge. */ |
585 | if (code == CALL_INSN) | |
586 | { | |
6af57aae | 587 | rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); |
8ad52449 | 588 | int region = (note ? INTVAL (XEXP (note, 0)) : 1); |
314883b8 | 589 | |
e881bb1b | 590 | call_had_abnormal_edge = 0; |
6af57aae | 591 | |
6814a8a0 JM |
592 | /* If there is an EH region or rethrow, we have an edge. */ |
593 | if ((eh_region && region > 0) | |
594 | || find_reg_note (insn, REG_EH_RETHROW, NULL_RTX)) | |
6af57aae | 595 | call_had_abnormal_edge = 1; |
314883b8 RK |
596 | else if (nonlocal_goto_handler_labels && region >= 0) |
597 | /* If there is a nonlocal goto label and the specified | |
598 | region number isn't -1, we have an edge. (0 means | |
599 | no throw, but might have a nonlocal goto). */ | |
600 | call_had_abnormal_edge = 1; | |
e881bb1b | 601 | } |
e881bb1b RH |
602 | |
603 | if (code != NOTE) | |
604 | prev_code = code; | |
605 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG) | |
606 | ++eh_region; | |
607 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END) | |
608 | --eh_region; | |
e881bb1b RH |
609 | } |
610 | ||
611 | /* The rest of the compiler works a bit smoother when we don't have to | |
612 | check for the edge case of do-nothing functions with no basic blocks. */ | |
613 | if (count == 0) | |
614 | { | |
615 | emit_insn (gen_rtx_USE (VOIDmode, const0_rtx)); | |
616 | count = 1; | |
617 | } | |
618 | ||
619 | return count; | |
620 | } | |
dc2ede84 | 621 | |
4eb00163 | 622 | /* Scan a list of insns for labels referred to other than by jumps. |
1bc48f82 | 623 | This is used to scan the alternatives of a call placeholder. */ |
4eb00163 JO |
624 | static rtx |
625 | find_label_refs (f, lvl) | |
1bc48f82 RE |
626 | rtx f; |
627 | rtx lvl; | |
628 | { | |
629 | rtx insn; | |
630 | ||
631 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
2c3c49de | 632 | if (INSN_P (insn)) |
1bc48f82 RE |
633 | { |
634 | rtx note; | |
635 | ||
636 | /* Make a list of all labels referred to other than by jumps | |
c9bacfdb | 637 | (which just don't have the REG_LABEL notes). |
1bc48f82 RE |
638 | |
639 | Make a special exception for labels followed by an ADDR*VEC, | |
c9bacfdb | 640 | as this would be a part of the tablejump setup code. |
1bc48f82 RE |
641 | |
642 | Make a special exception for the eh_return_stub_label, which | |
643 | we know isn't part of any otherwise visible control flow. */ | |
c9bacfdb | 644 | |
1bc48f82 RE |
645 | for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) |
646 | if (REG_NOTE_KIND (note) == REG_LABEL) | |
647 | { | |
648 | rtx lab = XEXP (note, 0), next; | |
649 | ||
650 | if (lab == eh_return_stub_label) | |
651 | ; | |
652 | else if ((next = next_nonnote_insn (lab)) != NULL | |
653 | && GET_CODE (next) == JUMP_INSN | |
654 | && (GET_CODE (PATTERN (next)) == ADDR_VEC | |
655 | || GET_CODE (PATTERN (next)) == ADDR_DIFF_VEC)) | |
656 | ; | |
657 | else if (GET_CODE (lab) == NOTE) | |
658 | ; | |
659 | else | |
660 | lvl = alloc_EXPR_LIST (0, XEXP (note, 0), lvl); | |
661 | } | |
662 | } | |
663 | ||
664 | return lvl; | |
665 | } | |
666 | ||
d7429b6a | 667 | /* Find all basic blocks of the function whose first insn is F. |
d7429b6a | 668 | |
336a6399 RH |
669 | Collect and return a list of labels whose addresses are taken. This |
670 | will be used in make_edges for use with computed gotos. */ | |
8329b5ec | 671 | |
be1bb652 | 672 | static void |
336a6399 | 673 | find_basic_blocks_1 (f) |
e881bb1b | 674 | rtx f; |
e881bb1b RH |
675 | { |
676 | register rtx insn, next; | |
e881bb1b RH |
677 | int i = 0; |
678 | rtx bb_note = NULL_RTX; | |
679 | rtx eh_list = NULL_RTX; | |
be1bb652 RH |
680 | rtx lvl = NULL_RTX; |
681 | rtx trll = NULL_RTX; | |
e881bb1b RH |
682 | rtx head = NULL_RTX; |
683 | rtx end = NULL_RTX; | |
c9bacfdb | 684 | |
e881bb1b RH |
685 | /* We process the instructions in a slightly different way than we did |
686 | previously. This is so that we see a NOTE_BASIC_BLOCK after we have | |
687 | closed out the previous block, so that it gets attached at the proper | |
688 | place. Since this form should be equivalent to the previous, | |
336a6399 | 689 | count_basic_blocks continues to use the old form as a check. */ |
d7429b6a | 690 | |
e881bb1b RH |
691 | for (insn = f; insn; insn = next) |
692 | { | |
693 | enum rtx_code code = GET_CODE (insn); | |
d7429b6a | 694 | |
e881bb1b | 695 | next = NEXT_INSN (insn); |
d7429b6a | 696 | |
e881bb1b | 697 | switch (code) |
e658434c | 698 | { |
e881bb1b RH |
699 | case NOTE: |
700 | { | |
701 | int kind = NOTE_LINE_NUMBER (insn); | |
702 | ||
703 | /* Keep a LIFO list of the currently active exception notes. */ | |
704 | if (kind == NOTE_INSN_EH_REGION_BEG) | |
336a6399 | 705 | eh_list = alloc_INSN_LIST (insn, eh_list); |
e881bb1b | 706 | else if (kind == NOTE_INSN_EH_REGION_END) |
336a6399 RH |
707 | { |
708 | rtx t = eh_list; | |
314883b8 | 709 | |
336a6399 RH |
710 | eh_list = XEXP (eh_list, 1); |
711 | free_INSN_LIST_node (t); | |
712 | } | |
e881bb1b | 713 | |
c9bacfdb | 714 | /* Look for basic block notes with which to keep the |
e881bb1b RH |
715 | basic_block_info pointers stable. Unthread the note now; |
716 | we'll put it back at the right place in create_basic_block. | |
717 | Or not at all if we've already found a note in this block. */ | |
718 | else if (kind == NOTE_INSN_BASIC_BLOCK) | |
719 | { | |
720 | if (bb_note == NULL_RTX) | |
721 | bb_note = insn; | |
47095bfc RH |
722 | else |
723 | next = flow_delete_insn (insn); | |
e881bb1b | 724 | } |
e881bb1b RH |
725 | break; |
726 | } | |
d7429b6a | 727 | |
e881bb1b | 728 | case CODE_LABEL: |
c9bacfdb | 729 | /* A basic block starts at a label. If we've closed one off due |
e881bb1b RH |
730 | to a barrier or some such, no need to do it again. */ |
731 | if (head != NULL_RTX) | |
2ec1535d | 732 | { |
e881bb1b RH |
733 | /* While we now have edge lists with which other portions of |
734 | the compiler might determine a call ending a basic block | |
735 | does not imply an abnormal edge, it will be a bit before | |
736 | everything can be updated. So continue to emit a noop at | |
737 | the end of such a block. */ | |
314883b8 | 738 | if (GET_CODE (end) == CALL_INSN && ! SIBLING_CALL_P (end)) |
e881bb1b RH |
739 | { |
740 | rtx nop = gen_rtx_USE (VOIDmode, const0_rtx); | |
741 | end = emit_insn_after (nop, end); | |
742 | } | |
743 | ||
e881bb1b RH |
744 | create_basic_block (i++, head, end, bb_note); |
745 | bb_note = NULL_RTX; | |
2ec1535d | 746 | } |
314883b8 | 747 | |
e881bb1b RH |
748 | head = end = insn; |
749 | break; | |
d06c6389 | 750 | |
e881bb1b RH |
751 | case JUMP_INSN: |
752 | /* A basic block ends at a jump. */ | |
753 | if (head == NULL_RTX) | |
754 | head = insn; | |
755 | else | |
756 | { | |
c9bacfdb | 757 | /* ??? Make a special check for table jumps. The way this |
7a3b7acb | 758 | happens is truly and amazingly gross. We are about to |
e881bb1b RH |
759 | create a basic block that contains just a code label and |
760 | an addr*vec jump insn. Worse, an addr_diff_vec creates | |
761 | its own natural loop. | |
5c35539b | 762 | |
e881bb1b | 763 | Prevent this bit of brain damage, pasting things together |
c9bacfdb | 764 | correctly in make_edges. |
2c3a56ad | 765 | |
e881bb1b RH |
766 | The correct solution involves emitting the table directly |
767 | on the tablejump instruction as a note, or JUMP_LABEL. */ | |
e658434c | 768 | |
e881bb1b RH |
769 | if (GET_CODE (PATTERN (insn)) == ADDR_VEC |
770 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC) | |
771 | { | |
772 | head = end = NULL; | |
773 | n_basic_blocks--; | |
774 | break; | |
775 | } | |
776 | } | |
777 | end = insn; | |
778 | goto new_bb_inclusive; | |
d7429b6a | 779 | |
e881bb1b RH |
780 | case BARRIER: |
781 | /* A basic block ends at a barrier. It may be that an unconditional | |
782 | jump already closed the basic block -- no need to do it again. */ | |
783 | if (head == NULL_RTX) | |
784 | break; | |
d7429b6a | 785 | |
e881bb1b RH |
786 | /* While we now have edge lists with which other portions of the |
787 | compiler might determine a call ending a basic block does not | |
788 | imply an abnormal edge, it will be a bit before everything can | |
789 | be updated. So continue to emit a noop at the end of such a | |
790 | block. */ | |
314883b8 | 791 | if (GET_CODE (end) == CALL_INSN && ! SIBLING_CALL_P (end)) |
e881bb1b RH |
792 | { |
793 | rtx nop = gen_rtx_USE (VOIDmode, const0_rtx); | |
794 | end = emit_insn_after (nop, end); | |
795 | } | |
796 | goto new_bb_exclusive; | |
797 | ||
798 | case CALL_INSN: | |
314883b8 RK |
799 | { |
800 | /* Record whether this call created an edge. */ | |
801 | rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); | |
802 | int region = (note ? INTVAL (XEXP (note, 0)) : 1); | |
803 | int call_has_abnormal_edge = 0; | |
804 | ||
1bc48f82 RE |
805 | if (GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER) |
806 | { | |
807 | /* Scan each of the alternatives for label refs. */ | |
808 | lvl = find_label_refs (XEXP (PATTERN (insn), 0), lvl); | |
809 | lvl = find_label_refs (XEXP (PATTERN (insn), 1), lvl); | |
810 | lvl = find_label_refs (XEXP (PATTERN (insn), 2), lvl); | |
811 | /* Record its tail recursion label, if any. */ | |
812 | if (XEXP (PATTERN (insn), 3) != NULL_RTX) | |
813 | trll = alloc_EXPR_LIST (0, XEXP (PATTERN (insn), 3), trll); | |
814 | } | |
be1bb652 | 815 | |
314883b8 RK |
816 | /* If there is an EH region or rethrow, we have an edge. */ |
817 | if ((eh_list && region > 0) | |
818 | || find_reg_note (insn, REG_EH_RETHROW, NULL_RTX)) | |
819 | call_has_abnormal_edge = 1; | |
820 | else if (nonlocal_goto_handler_labels && region >= 0) | |
821 | /* If there is a nonlocal goto label and the specified | |
822 | region number isn't -1, we have an edge. (0 means | |
823 | no throw, but might have a nonlocal goto). */ | |
824 | call_has_abnormal_edge = 1; | |
e881bb1b | 825 | |
314883b8 | 826 | /* A basic block ends at a call that can either throw or |
c29ea88a RK |
827 | do a non-local goto. */ |
828 | if (call_has_abnormal_edge) | |
314883b8 RK |
829 | { |
830 | new_bb_inclusive: | |
831 | if (head == NULL_RTX) | |
832 | head = insn; | |
833 | end = insn; | |
834 | ||
835 | new_bb_exclusive: | |
836 | create_basic_block (i++, head, end, bb_note); | |
837 | head = end = NULL_RTX; | |
838 | bb_note = NULL_RTX; | |
839 | break; | |
840 | } | |
c9bacfdb KH |
841 | } |
842 | /* Fall through. */ | |
d7429b6a | 843 | |
e881bb1b RH |
844 | default: |
845 | if (GET_RTX_CLASS (code) == 'i') | |
846 | { | |
847 | if (head == NULL_RTX) | |
848 | head = insn; | |
849 | end = insn; | |
850 | } | |
851 | break; | |
852 | } | |
d7429b6a | 853 | |
e881bb1b | 854 | if (GET_RTX_CLASS (code) == 'i') |
d7429b6a | 855 | { |
e881bb1b | 856 | rtx note; |
421382ac | 857 | |
e881bb1b | 858 | /* Make a list of all labels referred to other than by jumps |
c9bacfdb | 859 | (which just don't have the REG_LABEL notes). |
2ec1535d | 860 | |
e881bb1b | 861 | Make a special exception for labels followed by an ADDR*VEC, |
c9bacfdb | 862 | as this would be a part of the tablejump setup code. |
421382ac | 863 | |
e881bb1b RH |
864 | Make a special exception for the eh_return_stub_label, which |
865 | we know isn't part of any otherwise visible control flow. */ | |
c9bacfdb | 866 | |
e881bb1b | 867 | for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) |
c29ea88a RK |
868 | if (REG_NOTE_KIND (note) == REG_LABEL) |
869 | { | |
870 | rtx lab = XEXP (note, 0), next; | |
314883b8 | 871 | |
c29ea88a | 872 | if (lab == eh_return_stub_label) |
be1bb652 | 873 | ; |
c29ea88a RK |
874 | else if ((next = next_nonnote_insn (lab)) != NULL |
875 | && GET_CODE (next) == JUMP_INSN | |
876 | && (GET_CODE (PATTERN (next)) == ADDR_VEC | |
877 | || GET_CODE (PATTERN (next)) == ADDR_DIFF_VEC)) | |
878 | ; | |
be1bb652 RH |
879 | else if (GET_CODE (lab) == NOTE) |
880 | ; | |
c29ea88a | 881 | else |
be1bb652 | 882 | lvl = alloc_EXPR_LIST (0, XEXP (note, 0), lvl); |
c29ea88a | 883 | } |
d7429b6a | 884 | } |
e881bb1b | 885 | } |
d7429b6a | 886 | |
e881bb1b | 887 | if (head != NULL_RTX) |
336a6399 | 888 | create_basic_block (i++, head, end, bb_note); |
0d12ea97 RH |
889 | else if (bb_note) |
890 | flow_delete_insn (bb_note); | |
af14ce9c | 891 | |
e881bb1b RH |
892 | if (i != n_basic_blocks) |
893 | abort (); | |
af14ce9c | 894 | |
be1bb652 RH |
895 | label_value_list = lvl; |
896 | tail_recursion_label_list = trll; | |
d7429b6a | 897 | } |
5ece9746 | 898 | |
19d3c25c RH |
899 | /* Tidy the CFG by deleting unreachable code and whatnot. */ |
900 | ||
901 | void | |
902 | cleanup_cfg (f) | |
903 | rtx f; | |
904 | { | |
905 | delete_unreachable_blocks (); | |
906 | move_stray_eh_region_notes (); | |
907 | record_active_eh_regions (f); | |
908 | try_merge_blocks (); | |
909 | mark_critical_edges (); | |
2cade2ad CP |
910 | |
911 | /* Kill the data we won't maintain. */ | |
be1bb652 RH |
912 | free_EXPR_LIST_list (&label_value_list); |
913 | free_EXPR_LIST_list (&tail_recursion_label_list); | |
19d3c25c RH |
914 | } |
915 | ||
e881bb1b RH |
916 | /* Create a new basic block consisting of the instructions between |
917 | HEAD and END inclusive. Reuses the note and basic block struct | |
918 | in BB_NOTE, if any. */ | |
5ece9746 | 919 | |
295ae817 | 920 | void |
e881bb1b RH |
921 | create_basic_block (index, head, end, bb_note) |
922 | int index; | |
923 | rtx head, end, bb_note; | |
5ece9746 | 924 | { |
e881bb1b RH |
925 | basic_block bb; |
926 | ||
927 | if (bb_note | |
b3bf5bde | 928 | && ! RTX_INTEGRATED_P (bb_note) |
e881bb1b RH |
929 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL |
930 | && bb->aux == NULL) | |
5ece9746 | 931 | { |
e881bb1b RH |
932 | /* If we found an existing note, thread it back onto the chain. */ |
933 | ||
47095bfc RH |
934 | rtx after; |
935 | ||
e881bb1b | 936 | if (GET_CODE (head) == CODE_LABEL) |
47095bfc | 937 | after = head; |
e881bb1b RH |
938 | else |
939 | { | |
47095bfc | 940 | after = PREV_INSN (head); |
e881bb1b RH |
941 | head = bb_note; |
942 | } | |
47095bfc RH |
943 | |
944 | if (after != bb_note && NEXT_INSN (after) != bb_note) | |
945 | reorder_insns (bb_note, bb_note, after); | |
5ece9746 | 946 | } |
e881bb1b RH |
947 | else |
948 | { | |
949 | /* Otherwise we must create a note and a basic block structure. | |
950 | Since we allow basic block structs in rtl, give the struct | |
951 | the same lifetime by allocating it off the function obstack | |
952 | rather than using malloc. */ | |
8329b5ec | 953 | |
1f8f4a0b | 954 | bb = (basic_block) obstack_alloc (&flow_obstack, sizeof (*bb)); |
e881bb1b | 955 | memset (bb, 0, sizeof (*bb)); |
421382ac | 956 | |
e881bb1b RH |
957 | if (GET_CODE (head) == CODE_LABEL) |
958 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
959 | else | |
960 | { | |
961 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
962 | head = bb_note; | |
963 | } | |
964 | NOTE_BASIC_BLOCK (bb_note) = bb; | |
965 | } | |
966 | ||
eeea333e RH |
967 | /* Always include the bb note in the block. */ |
968 | if (NEXT_INSN (end) == bb_note) | |
969 | end = bb_note; | |
970 | ||
e881bb1b RH |
971 | bb->head = head; |
972 | bb->end = end; | |
973 | bb->index = index; | |
974 | BASIC_BLOCK (index) = bb; | |
975 | ||
976 | /* Tag the block so that we know it has been used when considering | |
977 | other basic block notes. */ | |
978 | bb->aux = bb; | |
421382ac | 979 | } |
e881bb1b RH |
980 | \f |
981 | /* Records the basic block struct in BB_FOR_INSN, for every instruction | |
982 | indexed by INSN_UID. MAX is the size of the array. */ | |
421382ac | 983 | |
2307e372 RH |
984 | void |
985 | compute_bb_for_insn (max) | |
e881bb1b | 986 | int max; |
421382ac | 987 | { |
e881bb1b | 988 | int i; |
421382ac | 989 | |
49c3bb12 RH |
990 | if (basic_block_for_insn) |
991 | VARRAY_FREE (basic_block_for_insn); | |
2307e372 RH |
992 | VARRAY_BB_INIT (basic_block_for_insn, max, "basic_block_for_insn"); |
993 | ||
e881bb1b RH |
994 | for (i = 0; i < n_basic_blocks; ++i) |
995 | { | |
996 | basic_block bb = BASIC_BLOCK (i); | |
997 | rtx insn, end; | |
998 | ||
999 | end = bb->end; | |
1000 | insn = bb->head; | |
1001 | while (1) | |
1002 | { | |
1003 | int uid = INSN_UID (insn); | |
1004 | if (uid < max) | |
2307e372 | 1005 | VARRAY_BB (basic_block_for_insn, uid) = bb; |
e881bb1b RH |
1006 | if (insn == end) |
1007 | break; | |
1008 | insn = NEXT_INSN (insn); | |
1009 | } | |
1010 | } | |
421382ac BS |
1011 | } |
1012 | ||
e881bb1b | 1013 | /* Free the memory associated with the edge structures. */ |
421382ac BS |
1014 | |
1015 | static void | |
e881bb1b | 1016 | clear_edges () |
421382ac | 1017 | { |
e881bb1b RH |
1018 | int i; |
1019 | edge n, e; | |
421382ac | 1020 | |
e881bb1b | 1021 | for (i = 0; i < n_basic_blocks; ++i) |
421382ac | 1022 | { |
e881bb1b | 1023 | basic_block bb = BASIC_BLOCK (i); |
421382ac | 1024 | |
c9bacfdb | 1025 | for (e = bb->succ; e; e = n) |
421382ac | 1026 | { |
e881bb1b RH |
1027 | n = e->succ_next; |
1028 | free (e); | |
421382ac | 1029 | } |
e881bb1b RH |
1030 | |
1031 | bb->succ = 0; | |
1032 | bb->pred = 0; | |
1033 | } | |
1034 | ||
c9bacfdb | 1035 | for (e = ENTRY_BLOCK_PTR->succ; e; e = n) |
e881bb1b RH |
1036 | { |
1037 | n = e->succ_next; | |
1038 | free (e); | |
421382ac | 1039 | } |
e881bb1b RH |
1040 | |
1041 | ENTRY_BLOCK_PTR->succ = 0; | |
1042 | EXIT_BLOCK_PTR->pred = 0; | |
d3a923ee RH |
1043 | |
1044 | n_edges = 0; | |
421382ac BS |
1045 | } |
1046 | ||
e881bb1b RH |
1047 | /* Identify the edges between basic blocks. |
1048 | ||
1049 | NONLOCAL_LABEL_LIST is a list of non-local labels in the function. Blocks | |
1050 | that are otherwise unreachable may be reachable with a non-local goto. | |
1051 | ||
c9bacfdb | 1052 | BB_EH_END is an array indexed by basic block number in which we record |
e881bb1b RH |
1053 | the list of exception regions active at the end of the basic block. */ |
1054 | ||
dc2ede84 | 1055 | static void |
336a6399 | 1056 | make_edges (label_value_list) |
e881bb1b | 1057 | rtx label_value_list; |
dc2ede84 | 1058 | { |
e881bb1b | 1059 | int i; |
1ef1bf06 | 1060 | eh_nesting_info *eh_nest_info = init_eh_nesting_info (); |
dbf08f94 | 1061 | sbitmap *edge_cache = NULL; |
e881bb1b RH |
1062 | |
1063 | /* Assume no computed jump; revise as we create edges. */ | |
1064 | current_function_has_computed_jump = 0; | |
1065 | ||
dbf08f94 RH |
1066 | /* Heavy use of computed goto in machine-generated code can lead to |
1067 | nearly fully-connected CFGs. In that case we spend a significant | |
1068 | amount of time searching the edge lists for duplicates. */ | |
1069 | if (forced_labels || label_value_list) | |
1070 | { | |
1071 | edge_cache = sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks); | |
1072 | sbitmap_vector_zero (edge_cache, n_basic_blocks); | |
1073 | } | |
1074 | ||
e881bb1b | 1075 | /* By nature of the way these get numbered, block 0 is always the entry. */ |
dbf08f94 | 1076 | make_edge (edge_cache, ENTRY_BLOCK_PTR, BASIC_BLOCK (0), EDGE_FALLTHRU); |
dc2ede84 | 1077 | |
e881bb1b | 1078 | for (i = 0; i < n_basic_blocks; ++i) |
421382ac | 1079 | { |
e881bb1b | 1080 | basic_block bb = BASIC_BLOCK (i); |
336a6399 | 1081 | rtx insn, x; |
e881bb1b | 1082 | enum rtx_code code; |
4b523fc4 | 1083 | int force_fallthru = 0; |
421382ac | 1084 | |
336a6399 | 1085 | /* Examine the last instruction of the block, and discover the |
e881bb1b RH |
1086 | ways we can leave the block. */ |
1087 | ||
1088 | insn = bb->end; | |
1089 | code = GET_CODE (insn); | |
1090 | ||
1091 | /* A branch. */ | |
1092 | if (code == JUMP_INSN) | |
1093 | { | |
1094 | rtx tmp; | |
1095 | ||
1096 | /* ??? Recognize a tablejump and do the right thing. */ | |
1097 | if ((tmp = JUMP_LABEL (insn)) != NULL_RTX | |
1098 | && (tmp = NEXT_INSN (tmp)) != NULL_RTX | |
1099 | && GET_CODE (tmp) == JUMP_INSN | |
1100 | && (GET_CODE (PATTERN (tmp)) == ADDR_VEC | |
1101 | || GET_CODE (PATTERN (tmp)) == ADDR_DIFF_VEC)) | |
1102 | { | |
1103 | rtvec vec; | |
1104 | int j; | |
1105 | ||
1106 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) | |
1107 | vec = XVEC (PATTERN (tmp), 0); | |
1108 | else | |
1109 | vec = XVEC (PATTERN (tmp), 1); | |
1110 | ||
1111 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
dbf08f94 RH |
1112 | make_label_edge (edge_cache, bb, |
1113 | XEXP (RTVEC_ELT (vec, j), 0), 0); | |
4b523fc4 RE |
1114 | |
1115 | /* Some targets (eg, ARM) emit a conditional jump that also | |
1116 | contains the out-of-range target. Scan for these and | |
1117 | add an edge if necessary. */ | |
1118 | if ((tmp = single_set (insn)) != NULL | |
1119 | && SET_DEST (tmp) == pc_rtx | |
1120 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
1121 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF) | |
dbf08f94 RH |
1122 | make_label_edge (edge_cache, bb, |
1123 | XEXP (XEXP (SET_SRC (tmp), 2), 0), 0); | |
4b523fc4 RE |
1124 | |
1125 | #ifdef CASE_DROPS_THROUGH | |
1126 | /* Silly VAXen. The ADDR_VEC is going to be in the way of | |
1127 | us naturally detecting fallthru into the next block. */ | |
1128 | force_fallthru = 1; | |
1129 | #endif | |
e881bb1b RH |
1130 | } |
1131 | ||
1132 | /* If this is a computed jump, then mark it as reaching | |
1133 | everything on the label_value_list and forced_labels list. */ | |
1134 | else if (computed_jump_p (insn)) | |
1135 | { | |
dc2ede84 | 1136 | current_function_has_computed_jump = 1; |
dc2ede84 | 1137 | |
e881bb1b | 1138 | for (x = label_value_list; x; x = XEXP (x, 1)) |
dbf08f94 | 1139 | make_label_edge (edge_cache, bb, XEXP (x, 0), EDGE_ABNORMAL); |
c9bacfdb | 1140 | |
dc2ede84 | 1141 | for (x = forced_labels; x; x = XEXP (x, 1)) |
dbf08f94 | 1142 | make_label_edge (edge_cache, bb, XEXP (x, 0), EDGE_ABNORMAL); |
dc2ede84 BS |
1143 | } |
1144 | ||
e881bb1b RH |
1145 | /* Returns create an exit out. */ |
1146 | else if (returnjump_p (insn)) | |
dbf08f94 | 1147 | make_edge (edge_cache, bb, EXIT_BLOCK_PTR, 0); |
e881bb1b RH |
1148 | |
1149 | /* Otherwise, we have a plain conditional or unconditional jump. */ | |
1150 | else | |
dc2ede84 | 1151 | { |
e881bb1b RH |
1152 | if (! JUMP_LABEL (insn)) |
1153 | abort (); | |
dbf08f94 | 1154 | make_label_edge (edge_cache, bb, JUMP_LABEL (insn), 0); |
e881bb1b RH |
1155 | } |
1156 | } | |
1157 | ||
c9bacfdb | 1158 | /* If this is a sibling call insn, then this is in effect a |
0a1c58a2 JL |
1159 | combined call and return, and so we need an edge to the |
1160 | exit block. No need to worry about EH edges, since we | |
1161 | wouldn't have created the sibling call in the first place. */ | |
1162 | ||
1163 | if (code == CALL_INSN && SIBLING_CALL_P (insn)) | |
9a1ba437 RH |
1164 | make_edge (edge_cache, bb, EXIT_BLOCK_PTR, |
1165 | EDGE_ABNORMAL | EDGE_ABNORMAL_CALL); | |
0a1c58a2 | 1166 | |
e881bb1b RH |
1167 | /* If this is a CALL_INSN, then mark it as reaching the active EH |
1168 | handler for this CALL_INSN. If we're handling asynchronous | |
1169 | exceptions then any insn can reach any of the active handlers. | |
b472794d | 1170 | |
e881bb1b | 1171 | Also mark the CALL_INSN as reaching any nonlocal goto handler. */ |
b472794d | 1172 | |
9a1ba437 | 1173 | else if (code == CALL_INSN || asynchronous_exceptions) |
e881bb1b | 1174 | { |
6814a8a0 JM |
1175 | /* Add any appropriate EH edges. We do this unconditionally |
1176 | since there may be a REG_EH_REGION or REG_EH_RETHROW note | |
1177 | on the call, and this needn't be within an EH region. */ | |
1178 | make_eh_edge (edge_cache, eh_nest_info, bb, insn, bb->eh_end); | |
336a6399 RH |
1179 | |
1180 | /* If we have asynchronous exceptions, do the same for *all* | |
1181 | exception regions active in the block. */ | |
1182 | if (asynchronous_exceptions | |
1183 | && bb->eh_beg != bb->eh_end) | |
e881bb1b | 1184 | { |
336a6399 | 1185 | if (bb->eh_beg >= 0) |
dbf08f94 RH |
1186 | make_eh_edge (edge_cache, eh_nest_info, bb, |
1187 | NULL_RTX, bb->eh_beg); | |
336a6399 | 1188 | |
7a3b7acb | 1189 | for (x = bb->head; x != bb->end; x = NEXT_INSN (x)) |
336a6399 RH |
1190 | if (GET_CODE (x) == NOTE |
1191 | && (NOTE_LINE_NUMBER (x) == NOTE_INSN_EH_REGION_BEG | |
1192 | || NOTE_LINE_NUMBER (x) == NOTE_INSN_EH_REGION_END)) | |
1193 | { | |
1194 | int region = NOTE_EH_HANDLER (x); | |
dbf08f94 RH |
1195 | make_eh_edge (edge_cache, eh_nest_info, bb, |
1196 | NULL_RTX, region); | |
336a6399 | 1197 | } |
e881bb1b RH |
1198 | } |
1199 | ||
1200 | if (code == CALL_INSN && nonlocal_goto_handler_labels) | |
1201 | { | |
dc2ede84 BS |
1202 | /* ??? This could be made smarter: in some cases it's possible |
1203 | to tell that certain calls will not do a nonlocal goto. | |
1204 | ||
1205 | For example, if the nested functions that do the nonlocal | |
1206 | gotos do not have their addresses taken, then only calls to | |
1207 | those functions or to other nested functions that use them | |
1208 | could possibly do nonlocal gotos. */ | |
1ef1bf06 AM |
1209 | /* We do know that a REG_EH_REGION note with a value less |
1210 | than 0 is guaranteed not to perform a non-local goto. */ | |
1211 | rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); | |
12a41c48 | 1212 | if (!note || INTVAL (XEXP (note, 0)) >= 0) |
c9bacfdb | 1213 | for (x = nonlocal_goto_handler_labels; x; x = XEXP (x, 1)) |
dbf08f94 | 1214 | make_label_edge (edge_cache, bb, XEXP (x, 0), |
1ef1bf06 | 1215 | EDGE_ABNORMAL | EDGE_ABNORMAL_CALL); |
dc2ede84 BS |
1216 | } |
1217 | } | |
e881bb1b RH |
1218 | |
1219 | /* We know something about the structure of the function __throw in | |
1220 | libgcc2.c. It is the only function that ever contains eh_stub | |
1221 | labels. It modifies its return address so that the last block | |
1222 | returns to one of the eh_stub labels within it. So we have to | |
1223 | make additional edges in the flow graph. */ | |
1224 | if (i + 1 == n_basic_blocks && eh_return_stub_label != 0) | |
dbf08f94 | 1225 | make_label_edge (edge_cache, bb, eh_return_stub_label, EDGE_EH); |
e881bb1b RH |
1226 | |
1227 | /* Find out if we can drop through to the next block. */ | |
1228 | insn = next_nonnote_insn (insn); | |
4b523fc4 | 1229 | if (!insn || (i + 1 == n_basic_blocks && force_fallthru)) |
dbf08f94 | 1230 | make_edge (edge_cache, bb, EXIT_BLOCK_PTR, EDGE_FALLTHRU); |
e881bb1b RH |
1231 | else if (i + 1 < n_basic_blocks) |
1232 | { | |
1233 | rtx tmp = BLOCK_HEAD (i + 1); | |
1234 | if (GET_CODE (tmp) == NOTE) | |
1235 | tmp = next_nonnote_insn (tmp); | |
4b523fc4 | 1236 | if (force_fallthru || insn == tmp) |
dbf08f94 | 1237 | make_edge (edge_cache, bb, BASIC_BLOCK (i + 1), EDGE_FALLTHRU); |
e881bb1b | 1238 | } |
dc2ede84 | 1239 | } |
dbf08f94 | 1240 | |
1ef1bf06 | 1241 | free_eh_nesting_info (eh_nest_info); |
dbf08f94 RH |
1242 | if (edge_cache) |
1243 | sbitmap_vector_free (edge_cache); | |
e881bb1b RH |
1244 | } |
1245 | ||
1246 | /* Create an edge between two basic blocks. FLAGS are auxiliary information | |
1247 | about the edge that is accumulated between calls. */ | |
1248 | ||
69732dcb | 1249 | void |
dbf08f94 RH |
1250 | make_edge (edge_cache, src, dst, flags) |
1251 | sbitmap *edge_cache; | |
e881bb1b RH |
1252 | basic_block src, dst; |
1253 | int flags; | |
1254 | { | |
dbf08f94 | 1255 | int use_edge_cache; |
e881bb1b RH |
1256 | edge e; |
1257 | ||
dbf08f94 RH |
1258 | /* Don't bother with edge cache for ENTRY or EXIT; there aren't that |
1259 | many edges to them, and we didn't allocate memory for it. */ | |
1260 | use_edge_cache = (edge_cache | |
1261 | && src != ENTRY_BLOCK_PTR | |
1262 | && dst != EXIT_BLOCK_PTR); | |
e881bb1b | 1263 | |
dbf08f94 | 1264 | /* Make sure we don't add duplicate edges. */ |
25e4379f MM |
1265 | switch (use_edge_cache) |
1266 | { | |
1267 | default: | |
1268 | /* Quick test for non-existance of the edge. */ | |
1269 | if (! TEST_BIT (edge_cache[src->index], dst->index)) | |
1270 | break; | |
1271 | ||
1272 | /* The edge exists; early exit if no work to do. */ | |
1273 | if (flags == 0) | |
1274 | return; | |
1275 | ||
1276 | /* FALLTHRU */ | |
1277 | case 0: | |
1278 | for (e = src->succ; e; e = e->succ_next) | |
1279 | if (e->dest == dst) | |
1280 | { | |
1281 | e->flags |= flags; | |
1282 | return; | |
1283 | } | |
1284 | break; | |
1285 | } | |
e881bb1b RH |
1286 | |
1287 | e = (edge) xcalloc (1, sizeof (*e)); | |
d3a923ee | 1288 | n_edges++; |
e881bb1b RH |
1289 | |
1290 | e->succ_next = src->succ; | |
1291 | e->pred_next = dst->pred; | |
1292 | e->src = src; | |
1293 | e->dest = dst; | |
1294 | e->flags = flags; | |
1295 | ||
1296 | src->succ = e; | |
1297 | dst->pred = e; | |
dbf08f94 RH |
1298 | |
1299 | if (use_edge_cache) | |
1300 | SET_BIT (edge_cache[src->index], dst->index); | |
e881bb1b RH |
1301 | } |
1302 | ||
1303 | /* Create an edge from a basic block to a label. */ | |
1304 | ||
1305 | static void | |
dbf08f94 RH |
1306 | make_label_edge (edge_cache, src, label, flags) |
1307 | sbitmap *edge_cache; | |
e881bb1b RH |
1308 | basic_block src; |
1309 | rtx label; | |
1310 | int flags; | |
1311 | { | |
1312 | if (GET_CODE (label) != CODE_LABEL) | |
1313 | abort (); | |
1314 | ||
1315 | /* If the label was never emitted, this insn is junk, but avoid a | |
1316 | crash trying to refer to BLOCK_FOR_INSN (label). This can happen | |
1317 | as a result of a syntax error and a diagnostic has already been | |
1318 | printed. */ | |
1319 | ||
1320 | if (INSN_UID (label) == 0) | |
1321 | return; | |
1322 | ||
dbf08f94 | 1323 | make_edge (edge_cache, src, BLOCK_FOR_INSN (label), flags); |
e881bb1b | 1324 | } |
e6cfb550 | 1325 | |
336a6399 RH |
1326 | /* Create the edges generated by INSN in REGION. */ |
1327 | ||
1328 | static void | |
dbf08f94 RH |
1329 | make_eh_edge (edge_cache, eh_nest_info, src, insn, region) |
1330 | sbitmap *edge_cache; | |
336a6399 RH |
1331 | eh_nesting_info *eh_nest_info; |
1332 | basic_block src; | |
1333 | rtx insn; | |
1334 | int region; | |
1335 | { | |
1336 | handler_info **handler_list; | |
1337 | int num, is_call; | |
1338 | ||
1339 | is_call = (insn && GET_CODE (insn) == CALL_INSN ? EDGE_ABNORMAL_CALL : 0); | |
1340 | num = reachable_handlers (region, eh_nest_info, insn, &handler_list); | |
1341 | while (--num >= 0) | |
1342 | { | |
dbf08f94 | 1343 | make_label_edge (edge_cache, src, handler_list[num]->handler_label, |
336a6399 RH |
1344 | EDGE_ABNORMAL | EDGE_EH | is_call); |
1345 | } | |
1346 | } | |
1347 | ||
1348 | /* EH_REGION notes appearing between basic blocks is ambiguous, and even | |
1349 | dangerous if we intend to move basic blocks around. Move such notes | |
1350 | into the following block. */ | |
1351 | ||
1352 | static void | |
1353 | move_stray_eh_region_notes () | |
1354 | { | |
1355 | int i; | |
1356 | basic_block b1, b2; | |
1357 | ||
1358 | if (n_basic_blocks < 2) | |
1359 | return; | |
1360 | ||
1361 | b2 = BASIC_BLOCK (n_basic_blocks - 1); | |
1362 | for (i = n_basic_blocks - 2; i >= 0; --i, b2 = b1) | |
1363 | { | |
1364 | rtx insn, next, list = NULL_RTX; | |
1365 | ||
1366 | b1 = BASIC_BLOCK (i); | |
1367 | for (insn = NEXT_INSN (b1->end); insn != b2->head; insn = next) | |
1368 | { | |
1369 | next = NEXT_INSN (insn); | |
1370 | if (GET_CODE (insn) == NOTE | |
1371 | && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG | |
1372 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)) | |
1373 | { | |
1374 | /* Unlink from the insn chain. */ | |
1375 | NEXT_INSN (PREV_INSN (insn)) = next; | |
1376 | PREV_INSN (next) = PREV_INSN (insn); | |
1377 | ||
1378 | /* Queue it. */ | |
1379 | NEXT_INSN (insn) = list; | |
1380 | list = insn; | |
1381 | } | |
1382 | } | |
1383 | ||
1384 | if (list == NULL_RTX) | |
1385 | continue; | |
1386 | ||
1387 | /* Find where to insert these things. */ | |
1388 | insn = b2->head; | |
1389 | if (GET_CODE (insn) == CODE_LABEL) | |
1390 | insn = NEXT_INSN (insn); | |
1391 | ||
1392 | while (list) | |
1393 | { | |
1394 | next = NEXT_INSN (list); | |
1395 | add_insn_after (list, insn); | |
1396 | list = next; | |
1397 | } | |
1398 | } | |
1399 | } | |
1400 | ||
1401 | /* Recompute eh_beg/eh_end for each basic block. */ | |
1402 | ||
1403 | static void | |
1404 | record_active_eh_regions (f) | |
1405 | rtx f; | |
1406 | { | |
1407 | rtx insn, eh_list = NULL_RTX; | |
1408 | int i = 0; | |
1409 | basic_block bb = BASIC_BLOCK (0); | |
1410 | ||
c9bacfdb | 1411 | for (insn = f; insn; insn = NEXT_INSN (insn)) |
336a6399 RH |
1412 | { |
1413 | if (bb->head == insn) | |
1414 | bb->eh_beg = (eh_list ? NOTE_EH_HANDLER (XEXP (eh_list, 0)) : -1); | |
1415 | ||
1416 | if (GET_CODE (insn) == NOTE) | |
1417 | { | |
1418 | int kind = NOTE_LINE_NUMBER (insn); | |
1419 | if (kind == NOTE_INSN_EH_REGION_BEG) | |
1420 | eh_list = alloc_INSN_LIST (insn, eh_list); | |
1421 | else if (kind == NOTE_INSN_EH_REGION_END) | |
1422 | { | |
1423 | rtx t = XEXP (eh_list, 1); | |
1424 | free_INSN_LIST_node (eh_list); | |
1425 | eh_list = t; | |
1426 | } | |
1427 | } | |
1428 | ||
1429 | if (bb->end == insn) | |
1430 | { | |
1431 | bb->eh_end = (eh_list ? NOTE_EH_HANDLER (XEXP (eh_list, 0)) : -1); | |
1432 | i += 1; | |
30439f29 JL |
1433 | if (i == n_basic_blocks) |
1434 | break; | |
336a6399 RH |
1435 | bb = BASIC_BLOCK (i); |
1436 | } | |
1437 | } | |
1438 | } | |
1439 | ||
e881bb1b | 1440 | /* Identify critical edges and set the bits appropriately. */ |
336a6399 | 1441 | |
e881bb1b RH |
1442 | static void |
1443 | mark_critical_edges () | |
1444 | { | |
1445 | int i, n = n_basic_blocks; | |
1446 | basic_block bb; | |
1447 | ||
1448 | /* We begin with the entry block. This is not terribly important now, | |
1449 | but could be if a front end (Fortran) implemented alternate entry | |
1450 | points. */ | |
1451 | bb = ENTRY_BLOCK_PTR; | |
1452 | i = -1; | |
1453 | ||
1454 | while (1) | |
e6cfb550 | 1455 | { |
e881bb1b RH |
1456 | edge e; |
1457 | ||
1458 | /* (1) Critical edges must have a source with multiple successors. */ | |
1459 | if (bb->succ && bb->succ->succ_next) | |
1460 | { | |
c9bacfdb | 1461 | for (e = bb->succ; e; e = e->succ_next) |
e881bb1b RH |
1462 | { |
1463 | /* (2) Critical edges must have a destination with multiple | |
1464 | predecessors. Note that we know there is at least one | |
1465 | predecessor -- the edge we followed to get here. */ | |
1466 | if (e->dest->pred->pred_next) | |
1467 | e->flags |= EDGE_CRITICAL; | |
1468 | else | |
1469 | e->flags &= ~EDGE_CRITICAL; | |
1470 | } | |
1471 | } | |
1472 | else | |
1473 | { | |
c9bacfdb | 1474 | for (e = bb->succ; e; e = e->succ_next) |
e881bb1b RH |
1475 | e->flags &= ~EDGE_CRITICAL; |
1476 | } | |
1477 | ||
1478 | if (++i >= n) | |
1479 | break; | |
1480 | bb = BASIC_BLOCK (i); | |
e6cfb550 | 1481 | } |
e881bb1b RH |
1482 | } |
1483 | \f | |
c586192c MH |
1484 | /* Split a block BB after insn INSN creating a new fallthru edge. |
1485 | Return the new edge. Note that to keep other parts of the compiler happy, | |
1486 | this function renumbers all the basic blocks so that the new | |
1487 | one has a number one greater than the block split. */ | |
1488 | ||
1489 | edge | |
1490 | split_block (bb, insn) | |
1491 | basic_block bb; | |
1492 | rtx insn; | |
1493 | { | |
1494 | basic_block new_bb; | |
1495 | edge new_edge; | |
1496 | edge e; | |
1497 | rtx bb_note; | |
1498 | int i, j; | |
1499 | ||
c586192c MH |
1500 | /* There is no point splitting the block after its end. */ |
1501 | if (bb->end == insn) | |
1502 | return 0; | |
1503 | ||
1504 | /* Create the new structures. */ | |
1f8f4a0b | 1505 | new_bb = (basic_block) obstack_alloc (&flow_obstack, sizeof (*new_bb)); |
c586192c MH |
1506 | new_edge = (edge) xcalloc (1, sizeof (*new_edge)); |
1507 | n_edges++; | |
1508 | ||
1509 | memset (new_bb, 0, sizeof (*new_bb)); | |
1510 | ||
1511 | new_bb->head = NEXT_INSN (insn); | |
1512 | new_bb->end = bb->end; | |
1513 | bb->end = insn; | |
1514 | ||
1515 | new_bb->succ = bb->succ; | |
1516 | bb->succ = new_edge; | |
1517 | new_bb->pred = new_edge; | |
1518 | new_bb->count = bb->count; | |
1519 | new_bb->loop_depth = bb->loop_depth; | |
1520 | ||
1521 | new_edge->src = bb; | |
1522 | new_edge->dest = new_bb; | |
1523 | new_edge->flags = EDGE_FALLTHRU; | |
1524 | new_edge->probability = REG_BR_PROB_BASE; | |
1525 | new_edge->count = bb->count; | |
1526 | ||
1527 | /* Redirect the src of the successor edges of bb to point to new_bb. */ | |
1528 | for (e = new_bb->succ; e; e = e->succ_next) | |
1529 | e->src = new_bb; | |
1530 | ||
1531 | /* Place the new block just after the block being split. */ | |
1532 | VARRAY_GROW (basic_block_info, ++n_basic_blocks); | |
1533 | ||
1534 | /* Some parts of the compiler expect blocks to be number in | |
1535 | sequential order so insert the new block immediately after the | |
1536 | block being split.. */ | |
1537 | j = bb->index; | |
1538 | for (i = n_basic_blocks - 1; i > j + 1; --i) | |
1539 | { | |
1540 | basic_block tmp = BASIC_BLOCK (i - 1); | |
1541 | BASIC_BLOCK (i) = tmp; | |
1542 | tmp->index = i; | |
1543 | } | |
1544 | ||
1545 | BASIC_BLOCK (i) = new_bb; | |
1546 | new_bb->index = i; | |
1547 | ||
1548 | /* Create the basic block note. */ | |
1549 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, | |
1550 | new_bb->head); | |
1551 | NOTE_BASIC_BLOCK (bb_note) = new_bb; | |
1552 | new_bb->head = bb_note; | |
1553 | ||
1554 | update_bb_for_insn (new_bb); | |
1555 | ||
1556 | if (bb->global_live_at_start) | |
1557 | { | |
1f8f4a0b MM |
1558 | new_bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); |
1559 | new_bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
c586192c MH |
1560 | COPY_REG_SET (new_bb->global_live_at_end, bb->global_live_at_end); |
1561 | ||
1562 | /* We now have to calculate which registers are live at the end | |
1563 | of the split basic block and at the start of the new basic | |
1564 | block. Start with those registers that are known to be live | |
1565 | at the end of the original basic block and get | |
1566 | propagate_block to determine which registers are live. */ | |
1567 | COPY_REG_SET (new_bb->global_live_at_start, bb->global_live_at_end); | |
7dfc0fbe | 1568 | propagate_block (new_bb, new_bb->global_live_at_start, NULL, NULL, 0); |
97ca9316 | 1569 | COPY_REG_SET (bb->global_live_at_end, |
c586192c MH |
1570 | new_bb->global_live_at_start); |
1571 | } | |
1572 | ||
1573 | return new_edge; | |
1574 | } | |
1575 | ||
1576 | ||
e881bb1b | 1577 | /* Split a (typically critical) edge. Return the new block. |
c9bacfdb | 1578 | Abort on abnormal edges. |
e881bb1b RH |
1579 | |
1580 | ??? The code generally expects to be called on critical edges. | |
c9bacfdb | 1581 | The case of a block ending in an unconditional jump to a |
e881bb1b RH |
1582 | block with multiple predecessors is not handled optimally. */ |
1583 | ||
1584 | basic_block | |
1585 | split_edge (edge_in) | |
1586 | edge edge_in; | |
1587 | { | |
1588 | basic_block old_pred, bb, old_succ; | |
1589 | edge edge_out; | |
1590 | rtx bb_note; | |
abb14ef5 | 1591 | int i, j; |
c9bacfdb | 1592 | |
e881bb1b RH |
1593 | /* Abnormal edges cannot be split. */ |
1594 | if ((edge_in->flags & EDGE_ABNORMAL) != 0) | |
1595 | abort (); | |
1596 | ||
1597 | old_pred = edge_in->src; | |
1598 | old_succ = edge_in->dest; | |
1599 | ||
1600 | /* Remove the existing edge from the destination's pred list. */ | |
1601 | { | |
1602 | edge *pp; | |
1603 | for (pp = &old_succ->pred; *pp != edge_in; pp = &(*pp)->pred_next) | |
1604 | continue; | |
1605 | *pp = edge_in->pred_next; | |
1e7d57a3 | 1606 | edge_in->pred_next = NULL; |
e881bb1b RH |
1607 | } |
1608 | ||
1609 | /* Create the new structures. */ | |
1f8f4a0b | 1610 | bb = (basic_block) obstack_alloc (&flow_obstack, sizeof (*bb)); |
e881bb1b | 1611 | edge_out = (edge) xcalloc (1, sizeof (*edge_out)); |
d3a923ee | 1612 | n_edges++; |
e881bb1b RH |
1613 | |
1614 | memset (bb, 0, sizeof (*bb)); | |
e881bb1b RH |
1615 | |
1616 | /* ??? This info is likely going to be out of date very soon. */ | |
e881bb1b RH |
1617 | if (old_succ->global_live_at_start) |
1618 | { | |
1f8f4a0b MM |
1619 | bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); |
1620 | bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
e881bb1b RH |
1621 | COPY_REG_SET (bb->global_live_at_start, old_succ->global_live_at_start); |
1622 | COPY_REG_SET (bb->global_live_at_end, old_succ->global_live_at_start); | |
1623 | } | |
e881bb1b RH |
1624 | |
1625 | /* Wire them up. */ | |
1626 | bb->pred = edge_in; | |
1627 | bb->succ = edge_out; | |
51891abe | 1628 | bb->count = edge_in->count; |
1e7d57a3 | 1629 | |
e881bb1b | 1630 | edge_in->dest = bb; |
1e7d57a3 JH |
1631 | edge_in->flags &= ~EDGE_CRITICAL; |
1632 | ||
1633 | edge_out->pred_next = old_succ->pred; | |
1634 | edge_out->succ_next = NULL; | |
e881bb1b RH |
1635 | edge_out->src = bb; |
1636 | edge_out->dest = old_succ; | |
1e7d57a3 JH |
1637 | edge_out->flags = EDGE_FALLTHRU; |
1638 | edge_out->probability = REG_BR_PROB_BASE; | |
51891abe | 1639 | edge_out->count = edge_in->count; |
1e7d57a3 JH |
1640 | |
1641 | old_succ->pred = edge_out; | |
e881bb1b RH |
1642 | |
1643 | /* Tricky case -- if there existed a fallthru into the successor | |
1644 | (and we're not it) we must add a new unconditional jump around | |
c9bacfdb | 1645 | the new block we're actually interested in. |
e881bb1b RH |
1646 | |
1647 | Further, if that edge is critical, this means a second new basic | |
1648 | block must be created to hold it. In order to simplify correct | |
1649 | insn placement, do this before we touch the existing basic block | |
1650 | ordering for the block we were really wanting. */ | |
1651 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1652 | { | |
1653 | edge e; | |
c9bacfdb | 1654 | for (e = edge_out->pred_next; e; e = e->pred_next) |
e881bb1b RH |
1655 | if (e->flags & EDGE_FALLTHRU) |
1656 | break; | |
1657 | ||
1658 | if (e) | |
1659 | { | |
1660 | basic_block jump_block; | |
1661 | rtx pos; | |
1662 | ||
d9d4fb43 AS |
1663 | if ((e->flags & EDGE_CRITICAL) == 0 |
1664 | && e->src != ENTRY_BLOCK_PTR) | |
e881bb1b RH |
1665 | { |
1666 | /* Non critical -- we can simply add a jump to the end | |
1667 | of the existing predecessor. */ | |
1668 | jump_block = e->src; | |
e881bb1b RH |
1669 | } |
1670 | else | |
1671 | { | |
1672 | /* We need a new block to hold the jump. The simplest | |
1673 | way to do the bulk of the work here is to recursively | |
1674 | call ourselves. */ | |
1675 | jump_block = split_edge (e); | |
1676 | e = jump_block->succ; | |
e881bb1b RH |
1677 | } |
1678 | ||
1e7d57a3 JH |
1679 | /* Now add the jump insn ... */ |
1680 | pos = emit_jump_insn_after (gen_jump (old_succ->head), | |
1681 | jump_block->end); | |
e881bb1b | 1682 | jump_block->end = pos; |
414094de JL |
1683 | if (basic_block_for_insn) |
1684 | set_block_for_insn (pos, jump_block); | |
e881bb1b | 1685 | emit_barrier_after (pos); |
1e7d57a3 JH |
1686 | |
1687 | /* ... let jump know that label is in use, ... */ | |
a8688bd6 | 1688 | JUMP_LABEL (pos) = old_succ->head; |
1e7d57a3 | 1689 | ++LABEL_NUSES (old_succ->head); |
c9bacfdb | 1690 | |
e881bb1b RH |
1691 | /* ... and clear fallthru on the outgoing edge. */ |
1692 | e->flags &= ~EDGE_FALLTHRU; | |
1693 | ||
1694 | /* Continue splitting the interesting edge. */ | |
1695 | } | |
1696 | } | |
1697 | ||
1698 | /* Place the new block just in front of the successor. */ | |
1699 | VARRAY_GROW (basic_block_info, ++n_basic_blocks); | |
abb14ef5 AM |
1700 | if (old_succ == EXIT_BLOCK_PTR) |
1701 | j = n_basic_blocks - 1; | |
1702 | else | |
1703 | j = old_succ->index; | |
1704 | for (i = n_basic_blocks - 1; i > j; --i) | |
e881bb1b RH |
1705 | { |
1706 | basic_block tmp = BASIC_BLOCK (i - 1); | |
1707 | BASIC_BLOCK (i) = tmp; | |
1708 | tmp->index = i; | |
1709 | } | |
1710 | BASIC_BLOCK (i) = bb; | |
1711 | bb->index = i; | |
1712 | ||
c9bacfdb | 1713 | /* Create the basic block note. |
9aa137f3 JL |
1714 | |
1715 | Where we place the note can have a noticable impact on the generated | |
c9bacfdb | 1716 | code. Consider this cfg: |
9aa137f3 JL |
1717 | |
1718 | E | |
1719 | | | |
1720 | 0 | |
1721 | / \ | |
1722 | +->1-->2--->E | |
1723 | | | | |
1724 | +--+ | |
1725 | ||
1726 | If we need to insert an insn on the edge from block 0 to block 1, | |
1727 | we want to ensure the instructions we insert are outside of any | |
1728 | loop notes that physically sit between block 0 and block 1. Otherwise | |
1729 | we confuse the loop optimizer into thinking the loop is a phony. */ | |
1730 | if (old_succ != EXIT_BLOCK_PTR | |
1731 | && PREV_INSN (old_succ->head) | |
1732 | && GET_CODE (PREV_INSN (old_succ->head)) == NOTE | |
1733 | && NOTE_LINE_NUMBER (PREV_INSN (old_succ->head)) == NOTE_INSN_LOOP_BEG) | |
1734 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, | |
1735 | PREV_INSN (old_succ->head)); | |
1736 | else if (old_succ != EXIT_BLOCK_PTR) | |
abb14ef5 AM |
1737 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, old_succ->head); |
1738 | else | |
1739 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
e881bb1b RH |
1740 | NOTE_BASIC_BLOCK (bb_note) = bb; |
1741 | bb->head = bb->end = bb_note; | |
1742 | ||
1743 | /* Not quite simple -- for non-fallthru edges, we must adjust the | |
1744 | predecessor's jump instruction to target our new block. */ | |
1745 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1746 | { | |
1747 | rtx tmp, insn = old_pred->end; | |
1748 | rtx old_label = old_succ->head; | |
1749 | rtx new_label = gen_label_rtx (); | |
1750 | ||
1751 | if (GET_CODE (insn) != JUMP_INSN) | |
1752 | abort (); | |
1753 | ||
1754 | /* ??? Recognize a tablejump and adjust all matching cases. */ | |
1755 | if ((tmp = JUMP_LABEL (insn)) != NULL_RTX | |
1756 | && (tmp = NEXT_INSN (tmp)) != NULL_RTX | |
1757 | && GET_CODE (tmp) == JUMP_INSN | |
1758 | && (GET_CODE (PATTERN (tmp)) == ADDR_VEC | |
1759 | || GET_CODE (PATTERN (tmp)) == ADDR_DIFF_VEC)) | |
1760 | { | |
1761 | rtvec vec; | |
1762 | int j; | |
1763 | ||
1764 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) | |
1765 | vec = XVEC (PATTERN (tmp), 0); | |
1766 | else | |
1767 | vec = XVEC (PATTERN (tmp), 1); | |
1768 | ||
1769 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
1770 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
1771 | { | |
c9bacfdb | 1772 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (VOIDmode, new_label); |
e881bb1b RH |
1773 | --LABEL_NUSES (old_label); |
1774 | ++LABEL_NUSES (new_label); | |
1775 | } | |
506f9fbf RE |
1776 | |
1777 | /* Handle casesi dispatch insns */ | |
1778 | if ((tmp = single_set (insn)) != NULL | |
1779 | && SET_DEST (tmp) == pc_rtx | |
1780 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
1781 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF | |
1782 | && XEXP (XEXP (SET_SRC (tmp), 2), 0) == old_label) | |
1783 | { | |
c9bacfdb | 1784 | XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (VOIDmode, |
506f9fbf RE |
1785 | new_label); |
1786 | --LABEL_NUSES (old_label); | |
1787 | ++LABEL_NUSES (new_label); | |
1788 | } | |
e881bb1b RH |
1789 | } |
1790 | else | |
1791 | { | |
1792 | /* This would have indicated an abnormal edge. */ | |
1793 | if (computed_jump_p (insn)) | |
1794 | abort (); | |
1795 | ||
1796 | /* A return instruction can't be redirected. */ | |
1797 | if (returnjump_p (insn)) | |
1798 | abort (); | |
1799 | ||
1800 | /* If the insn doesn't go where we think, we're confused. */ | |
1801 | if (JUMP_LABEL (insn) != old_label) | |
1802 | abort (); | |
1803 | ||
9ba11d5a | 1804 | redirect_jump (insn, new_label, 0); |
e881bb1b RH |
1805 | } |
1806 | ||
1807 | emit_label_before (new_label, bb_note); | |
1808 | bb->head = new_label; | |
1809 | } | |
1810 | ||
e881bb1b RH |
1811 | return bb; |
1812 | } | |
1813 | ||
1814 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1815 | The new instructions and basic blocks (if any) will not appear in the | |
1816 | CFG until commit_edge_insertions is called. */ | |
1817 | ||
1818 | void | |
1819 | insert_insn_on_edge (pattern, e) | |
1820 | rtx pattern; | |
1821 | edge e; | |
1822 | { | |
1823 | /* We cannot insert instructions on an abnormal critical edge. | |
1824 | It will be easier to find the culprit if we die now. */ | |
1825 | if ((e->flags & (EDGE_ABNORMAL|EDGE_CRITICAL)) | |
1826 | == (EDGE_ABNORMAL|EDGE_CRITICAL)) | |
1827 | abort (); | |
1828 | ||
1829 | if (e->insns == NULL_RTX) | |
1830 | start_sequence (); | |
1831 | else | |
1832 | push_to_sequence (e->insns); | |
1833 | ||
1834 | emit_insn (pattern); | |
1835 | ||
1836 | e->insns = get_insns (); | |
c9bacfdb | 1837 | end_sequence (); |
e881bb1b RH |
1838 | } |
1839 | ||
1840 | /* Update the CFG for the instructions queued on edge E. */ | |
1841 | ||
1842 | static void | |
1843 | commit_one_edge_insertion (e) | |
1844 | edge e; | |
1845 | { | |
f5540cd4 | 1846 | rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last; |
e881bb1b RH |
1847 | basic_block bb; |
1848 | ||
19d3c25c RH |
1849 | /* Pull the insns off the edge now since the edge might go away. */ |
1850 | insns = e->insns; | |
1851 | e->insns = NULL_RTX; | |
1852 | ||
e881bb1b RH |
1853 | /* Figure out where to put these things. If the destination has |
1854 | one predecessor, insert there. Except for the exit block. */ | |
1855 | if (e->dest->pred->pred_next == NULL | |
1856 | && e->dest != EXIT_BLOCK_PTR) | |
1857 | { | |
1858 | bb = e->dest; | |
1859 | ||
1860 | /* Get the location correct wrt a code label, and "nice" wrt | |
1861 | a basic block note, and before everything else. */ | |
1862 | tmp = bb->head; | |
1863 | if (GET_CODE (tmp) == CODE_LABEL) | |
1864 | tmp = NEXT_INSN (tmp); | |
589ca5cb | 1865 | if (NOTE_INSN_BASIC_BLOCK_P (tmp)) |
e881bb1b RH |
1866 | tmp = NEXT_INSN (tmp); |
1867 | if (tmp == bb->head) | |
1868 | before = tmp; | |
1869 | else | |
1870 | after = PREV_INSN (tmp); | |
1871 | } | |
c9bacfdb | 1872 | |
e881bb1b RH |
1873 | /* If the source has one successor and the edge is not abnormal, |
1874 | insert there. Except for the entry block. */ | |
1875 | else if ((e->flags & EDGE_ABNORMAL) == 0 | |
1876 | && e->src->succ->succ_next == NULL | |
1877 | && e->src != ENTRY_BLOCK_PTR) | |
1878 | { | |
1879 | bb = e->src; | |
08520ad8 JL |
1880 | /* It is possible to have a non-simple jump here. Consider a target |
1881 | where some forms of unconditional jumps clobber a register. This | |
c9bacfdb | 1882 | happens on the fr30 for example. |
08520ad8 JL |
1883 | |
1884 | We know this block has a single successor, so we can just emit | |
1885 | the queued insns before the jump. */ | |
e881bb1b RH |
1886 | if (GET_CODE (bb->end) == JUMP_INSN) |
1887 | { | |
e881bb1b RH |
1888 | before = bb->end; |
1889 | } | |
1890 | else | |
1891 | { | |
1892 | /* We'd better be fallthru, or we've lost track of what's what. */ | |
1893 | if ((e->flags & EDGE_FALLTHRU) == 0) | |
1894 | abort (); | |
1895 | ||
1896 | after = bb->end; | |
1897 | } | |
1898 | } | |
1899 | ||
1900 | /* Otherwise we must split the edge. */ | |
1901 | else | |
1902 | { | |
1903 | bb = split_edge (e); | |
1904 | after = bb->end; | |
1905 | } | |
1906 | ||
1907 | /* Now that we've found the spot, do the insertion. */ | |
a8688bd6 AM |
1908 | |
1909 | /* Set the new block number for these insns, if structure is allocated. */ | |
1910 | if (basic_block_for_insn) | |
1911 | { | |
1912 | rtx i; | |
19d3c25c | 1913 | for (i = insns; i != NULL_RTX; i = NEXT_INSN (i)) |
a8688bd6 AM |
1914 | set_block_for_insn (i, bb); |
1915 | } | |
1916 | ||
e881bb1b RH |
1917 | if (before) |
1918 | { | |
19d3c25c | 1919 | emit_insns_before (insns, before); |
e881bb1b | 1920 | if (before == bb->head) |
19d3c25c | 1921 | bb->head = insns; |
f5540cd4 RH |
1922 | |
1923 | last = prev_nonnote_insn (before); | |
e881bb1b RH |
1924 | } |
1925 | else | |
1926 | { | |
f5540cd4 | 1927 | last = emit_insns_after (insns, after); |
e881bb1b | 1928 | if (after == bb->end) |
f5540cd4 RH |
1929 | bb->end = last; |
1930 | } | |
19d3c25c | 1931 | |
f5540cd4 RH |
1932 | if (returnjump_p (last)) |
1933 | { | |
c9bacfdb | 1934 | /* ??? Remove all outgoing edges from BB and add one for EXIT. |
f5540cd4 RH |
1935 | This is not currently a problem because this only happens |
1936 | for the (single) epilogue, which already has a fallthru edge | |
1937 | to EXIT. */ | |
1938 | ||
1939 | e = bb->succ; | |
1940 | if (e->dest != EXIT_BLOCK_PTR | |
1941 | || e->succ_next != NULL | |
1942 | || (e->flags & EDGE_FALLTHRU) == 0) | |
1943 | abort (); | |
1944 | e->flags &= ~EDGE_FALLTHRU; | |
1945 | ||
1946 | emit_barrier_after (last); | |
1947 | bb->end = last; | |
1948 | ||
1949 | if (before) | |
1950 | flow_delete_insn (before); | |
e881bb1b | 1951 | } |
f5540cd4 RH |
1952 | else if (GET_CODE (last) == JUMP_INSN) |
1953 | abort (); | |
e881bb1b RH |
1954 | } |
1955 | ||
1956 | /* Update the CFG for all queued instructions. */ | |
1957 | ||
1958 | void | |
1959 | commit_edge_insertions () | |
1960 | { | |
1961 | int i; | |
1962 | basic_block bb; | |
1963 | ||
19d3c25c RH |
1964 | #ifdef ENABLE_CHECKING |
1965 | verify_flow_info (); | |
1966 | #endif | |
c9bacfdb | 1967 | |
e881bb1b RH |
1968 | i = -1; |
1969 | bb = ENTRY_BLOCK_PTR; | |
1970 | while (1) | |
1971 | { | |
1972 | edge e, next; | |
1973 | ||
c9bacfdb | 1974 | for (e = bb->succ; e; e = next) |
e881bb1b RH |
1975 | { |
1976 | next = e->succ_next; | |
1977 | if (e->insns) | |
1978 | commit_one_edge_insertion (e); | |
1979 | } | |
1980 | ||
1981 | if (++i >= n_basic_blocks) | |
1982 | break; | |
1983 | bb = BASIC_BLOCK (i); | |
1984 | } | |
1985 | } | |
1986 | \f | |
1987 | /* Delete all unreachable basic blocks. */ | |
1988 | ||
1989 | static void | |
1990 | delete_unreachable_blocks () | |
1991 | { | |
1992 | basic_block *worklist, *tos; | |
1993 | int deleted_handler; | |
1994 | edge e; | |
1995 | int i, n; | |
1996 | ||
1997 | n = n_basic_blocks; | |
67289ea6 | 1998 | tos = worklist = (basic_block *) xmalloc (sizeof (basic_block) * n); |
e881bb1b RH |
1999 | |
2000 | /* Use basic_block->aux as a marker. Clear them all. */ | |
2001 | ||
2002 | for (i = 0; i < n; ++i) | |
2003 | BASIC_BLOCK (i)->aux = NULL; | |
2004 | ||
2005 | /* Add our starting points to the worklist. Almost always there will | |
2006 | be only one. It isn't inconcievable that we might one day directly | |
2007 | support Fortran alternate entry points. */ | |
2008 | ||
c9bacfdb | 2009 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) |
aa3d4bf9 RH |
2010 | { |
2011 | *tos++ = e->dest; | |
2012 | ||
2013 | /* Mark the block with a handy non-null value. */ | |
2014 | e->dest->aux = e; | |
2015 | } | |
c9bacfdb | 2016 | |
e881bb1b RH |
2017 | /* Iterate: find everything reachable from what we've already seen. */ |
2018 | ||
2019 | while (tos != worklist) | |
2020 | { | |
2021 | basic_block b = *--tos; | |
2022 | ||
c9bacfdb | 2023 | for (e = b->succ; e; e = e->succ_next) |
e881bb1b | 2024 | if (!e->dest->aux) |
aa3d4bf9 RH |
2025 | { |
2026 | *tos++ = e->dest; | |
2027 | e->dest->aux = e; | |
2028 | } | |
e881bb1b RH |
2029 | } |
2030 | ||
2031 | /* Delete all unreachable basic blocks. Count down so that we don't | |
c9bacfdb | 2032 | interfere with the block renumbering that happens in flow_delete_block. */ |
e881bb1b RH |
2033 | |
2034 | deleted_handler = 0; | |
2035 | ||
2036 | for (i = n - 1; i >= 0; --i) | |
2037 | { | |
2038 | basic_block b = BASIC_BLOCK (i); | |
2039 | ||
2040 | if (b->aux != NULL) | |
2041 | /* This block was found. Tidy up the mark. */ | |
2042 | b->aux = NULL; | |
2043 | else | |
52294521 | 2044 | deleted_handler |= flow_delete_block (b); |
e881bb1b RH |
2045 | } |
2046 | ||
5568fb48 | 2047 | tidy_fallthru_edges (); |
e881bb1b | 2048 | |
e881bb1b | 2049 | /* If we deleted an exception handler, we may have EH region begin/end |
c9bacfdb | 2050 | blocks to remove as well. */ |
e881bb1b RH |
2051 | if (deleted_handler) |
2052 | delete_eh_regions (); | |
67289ea6 MM |
2053 | |
2054 | free (worklist); | |
e881bb1b RH |
2055 | } |
2056 | ||
2057 | /* Find EH regions for which there is no longer a handler, and delete them. */ | |
2058 | ||
2059 | static void | |
2060 | delete_eh_regions () | |
2061 | { | |
2062 | rtx insn; | |
2063 | ||
1ef1bf06 AM |
2064 | update_rethrow_references (); |
2065 | ||
e881bb1b RH |
2066 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) |
2067 | if (GET_CODE (insn) == NOTE) | |
2068 | { | |
c9bacfdb KH |
2069 | if ((NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG) |
2070 | || (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)) | |
e881bb1b | 2071 | { |
ef178af3 | 2072 | int num = NOTE_EH_HANDLER (insn); |
1ef1bf06 | 2073 | /* A NULL handler indicates a region is no longer needed, |
6814a8a0 | 2074 | as long as its rethrow label isn't used. */ |
1ef1bf06 | 2075 | if (get_first_handler (num) == NULL && ! rethrow_used (num)) |
e881bb1b RH |
2076 | { |
2077 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
2078 | NOTE_SOURCE_FILE (insn) = 0; | |
2079 | } | |
2080 | } | |
2081 | } | |
2082 | } | |
2083 | ||
2084 | /* Return true if NOTE is not one of the ones that must be kept paired, | |
2085 | so that we may simply delete them. */ | |
2086 | ||
2087 | static int | |
eeea333e | 2088 | can_delete_note_p (note) |
e881bb1b RH |
2089 | rtx note; |
2090 | { | |
2091 | return (NOTE_LINE_NUMBER (note) == NOTE_INSN_DELETED | |
2092 | || NOTE_LINE_NUMBER (note) == NOTE_INSN_BASIC_BLOCK); | |
2093 | } | |
2094 | ||
2095 | /* Unlink a chain of insns between START and FINISH, leaving notes | |
2096 | that must be paired. */ | |
2097 | ||
d3a923ee | 2098 | void |
5aabad00 | 2099 | flow_delete_insn_chain (start, finish) |
e881bb1b RH |
2100 | rtx start, finish; |
2101 | { | |
2102 | /* Unchain the insns one by one. It would be quicker to delete all | |
2103 | of these with a single unchaining, rather than one at a time, but | |
2104 | we need to keep the NOTE's. */ | |
2105 | ||
2106 | rtx next; | |
2107 | ||
2108 | while (1) | |
2109 | { | |
2110 | next = NEXT_INSN (start); | |
eeea333e RH |
2111 | if (GET_CODE (start) == NOTE && !can_delete_note_p (start)) |
2112 | ; | |
be1bb652 RH |
2113 | else if (GET_CODE (start) == CODE_LABEL |
2114 | && ! can_delete_label_p (start)) | |
2115 | { | |
2116 | const char *name = LABEL_NAME (start); | |
2117 | PUT_CODE (start, NOTE); | |
2118 | NOTE_LINE_NUMBER (start) = NOTE_INSN_DELETED_LABEL; | |
2119 | NOTE_SOURCE_FILE (start) = name; | |
2120 | } | |
eeea333e | 2121 | else |
e881bb1b RH |
2122 | next = flow_delete_insn (start); |
2123 | ||
2124 | if (start == finish) | |
2125 | break; | |
2126 | start = next; | |
2127 | } | |
2128 | } | |
2129 | ||
2130 | /* Delete the insns in a (non-live) block. We physically delete every | |
2131 | non-deleted-note insn, and update the flow graph appropriately. | |
2132 | ||
2133 | Return nonzero if we deleted an exception handler. */ | |
2134 | ||
2135 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
2136 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
2137 | ||
52294521 RH |
2138 | int |
2139 | flow_delete_block (b) | |
e881bb1b RH |
2140 | basic_block b; |
2141 | { | |
2142 | int deleted_handler = 0; | |
1519ae2c | 2143 | rtx insn, end, tmp; |
e881bb1b RH |
2144 | |
2145 | /* If the head of this block is a CODE_LABEL, then it might be the | |
2146 | label for an exception handler which can't be reached. | |
2147 | ||
2148 | We need to remove the label from the exception_handler_label list | |
3ad47811 MM |
2149 | and remove the associated NOTE_INSN_EH_REGION_BEG and |
2150 | NOTE_INSN_EH_REGION_END notes. */ | |
e881bb1b RH |
2151 | |
2152 | insn = b->head; | |
c9bacfdb | 2153 | |
312f6255 GK |
2154 | never_reached_warning (insn); |
2155 | ||
e881bb1b RH |
2156 | if (GET_CODE (insn) == CODE_LABEL) |
2157 | { | |
2158 | rtx x, *prev = &exception_handler_labels; | |
2159 | ||
2160 | for (x = exception_handler_labels; x; x = XEXP (x, 1)) | |
2161 | { | |
2162 | if (XEXP (x, 0) == insn) | |
2163 | { | |
2164 | /* Found a match, splice this label out of the EH label list. */ | |
2165 | *prev = XEXP (x, 1); | |
2166 | XEXP (x, 1) = NULL_RTX; | |
2167 | XEXP (x, 0) = NULL_RTX; | |
2168 | ||
2169 | /* Remove the handler from all regions */ | |
2170 | remove_handler (insn); | |
2171 | deleted_handler = 1; | |
2172 | break; | |
2173 | } | |
2174 | prev = &XEXP (x, 1); | |
2175 | } | |
e881bb1b RH |
2176 | } |
2177 | ||
1519ae2c RH |
2178 | /* Include any jump table following the basic block. */ |
2179 | end = b->end; | |
2180 | if (GET_CODE (end) == JUMP_INSN | |
2181 | && (tmp = JUMP_LABEL (end)) != NULL_RTX | |
2182 | && (tmp = NEXT_INSN (tmp)) != NULL_RTX | |
2183 | && GET_CODE (tmp) == JUMP_INSN | |
2184 | && (GET_CODE (PATTERN (tmp)) == ADDR_VEC | |
2185 | || GET_CODE (PATTERN (tmp)) == ADDR_DIFF_VEC)) | |
2186 | end = tmp; | |
2187 | ||
2188 | /* Include any barrier that may follow the basic block. */ | |
1fa4609a | 2189 | tmp = next_nonnote_insn (end); |
1519ae2c RH |
2190 | if (tmp && GET_CODE (tmp) == BARRIER) |
2191 | end = tmp; | |
2192 | ||
2193 | /* Selectively delete the entire chain. */ | |
5aabad00 | 2194 | flow_delete_insn_chain (insn, end); |
e881bb1b | 2195 | |
c9bacfdb | 2196 | /* Remove the edges into and out of this block. Note that there may |
e881bb1b RH |
2197 | indeed be edges in, if we are removing an unreachable loop. */ |
2198 | { | |
2199 | edge e, next, *q; | |
2200 | ||
c9bacfdb | 2201 | for (e = b->pred; e; e = next) |
e881bb1b RH |
2202 | { |
2203 | for (q = &e->src->succ; *q != e; q = &(*q)->succ_next) | |
2204 | continue; | |
2205 | *q = e->succ_next; | |
2206 | next = e->pred_next; | |
d3a923ee | 2207 | n_edges--; |
e881bb1b RH |
2208 | free (e); |
2209 | } | |
c9bacfdb | 2210 | for (e = b->succ; e; e = next) |
e881bb1b RH |
2211 | { |
2212 | for (q = &e->dest->pred; *q != e; q = &(*q)->pred_next) | |
2213 | continue; | |
2214 | *q = e->pred_next; | |
2215 | next = e->succ_next; | |
d3a923ee | 2216 | n_edges--; |
e881bb1b RH |
2217 | free (e); |
2218 | } | |
2219 | ||
2220 | b->pred = NULL; | |
2221 | b->succ = NULL; | |
2222 | } | |
2223 | ||
2224 | /* Remove the basic block from the array, and compact behind it. */ | |
2225 | expunge_block (b); | |
2226 | ||
2227 | return deleted_handler; | |
2228 | } | |
2229 | ||
2230 | /* Remove block B from the basic block array and compact behind it. */ | |
2231 | ||
2232 | static void | |
2233 | expunge_block (b) | |
2234 | basic_block b; | |
2235 | { | |
2236 | int i, n = n_basic_blocks; | |
2237 | ||
2238 | for (i = b->index; i + 1 < n; ++i) | |
2239 | { | |
2240 | basic_block x = BASIC_BLOCK (i + 1); | |
2241 | BASIC_BLOCK (i) = x; | |
2242 | x->index = i; | |
2243 | } | |
2244 | ||
2245 | basic_block_info->num_elements--; | |
2246 | n_basic_blocks--; | |
2247 | } | |
2248 | ||
2249 | /* Delete INSN by patching it out. Return the next insn. */ | |
2250 | ||
69732dcb | 2251 | rtx |
e881bb1b RH |
2252 | flow_delete_insn (insn) |
2253 | rtx insn; | |
2254 | { | |
2255 | rtx prev = PREV_INSN (insn); | |
2256 | rtx next = NEXT_INSN (insn); | |
1519ae2c | 2257 | rtx note; |
e881bb1b RH |
2258 | |
2259 | PREV_INSN (insn) = NULL_RTX; | |
2260 | NEXT_INSN (insn) = NULL_RTX; | |
aa9e158d | 2261 | INSN_DELETED_P (insn) = 1; |
c9bacfdb | 2262 | |
e881bb1b RH |
2263 | if (prev) |
2264 | NEXT_INSN (prev) = next; | |
2265 | if (next) | |
2266 | PREV_INSN (next) = prev; | |
2267 | else | |
2268 | set_last_insn (prev); | |
e6cfb550 | 2269 | |
55a98783 JL |
2270 | if (GET_CODE (insn) == CODE_LABEL) |
2271 | remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels); | |
2272 | ||
e881bb1b RH |
2273 | /* If deleting a jump, decrement the use count of the label. Deleting |
2274 | the label itself should happen in the normal course of block merging. */ | |
f5540cd4 RH |
2275 | if (GET_CODE (insn) == JUMP_INSN |
2276 | && JUMP_LABEL (insn) | |
2277 | && GET_CODE (JUMP_LABEL (insn)) == CODE_LABEL) | |
e881bb1b RH |
2278 | LABEL_NUSES (JUMP_LABEL (insn))--; |
2279 | ||
1519ae2c | 2280 | /* Also if deleting an insn that references a label. */ |
f5540cd4 RH |
2281 | else if ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)) != NULL_RTX |
2282 | && GET_CODE (XEXP (note, 0)) == CODE_LABEL) | |
1519ae2c RH |
2283 | LABEL_NUSES (XEXP (note, 0))--; |
2284 | ||
e881bb1b | 2285 | return next; |
d7429b6a | 2286 | } |
8329b5ec | 2287 | |
e881bb1b RH |
2288 | /* True if a given label can be deleted. */ |
2289 | ||
c9bacfdb | 2290 | static int |
e881bb1b RH |
2291 | can_delete_label_p (label) |
2292 | rtx label; | |
dc2ede84 | 2293 | { |
e881bb1b | 2294 | rtx x; |
dc2ede84 | 2295 | |
e881bb1b RH |
2296 | if (LABEL_PRESERVE_P (label)) |
2297 | return 0; | |
421382ac | 2298 | |
c9bacfdb | 2299 | for (x = forced_labels; x; x = XEXP (x, 1)) |
e881bb1b RH |
2300 | if (label == XEXP (x, 0)) |
2301 | return 0; | |
c9bacfdb | 2302 | for (x = label_value_list; x; x = XEXP (x, 1)) |
e881bb1b RH |
2303 | if (label == XEXP (x, 0)) |
2304 | return 0; | |
c9bacfdb | 2305 | for (x = exception_handler_labels; x; x = XEXP (x, 1)) |
e881bb1b RH |
2306 | if (label == XEXP (x, 0)) |
2307 | return 0; | |
dc2ede84 | 2308 | |
abb3f0a9 | 2309 | /* User declared labels must be preserved. */ |
088e7160 | 2310 | if (LABEL_NAME (label) != 0) |
abb3f0a9 | 2311 | return 0; |
c9bacfdb | 2312 | |
e881bb1b RH |
2313 | return 1; |
2314 | } | |
421382ac | 2315 | |
be1bb652 RH |
2316 | static int |
2317 | tail_recursion_label_p (label) | |
2318 | rtx label; | |
2319 | { | |
2320 | rtx x; | |
2321 | ||
c9bacfdb | 2322 | for (x = tail_recursion_label_list; x; x = XEXP (x, 1)) |
be1bb652 RH |
2323 | if (label == XEXP (x, 0)) |
2324 | return 1; | |
2325 | ||
2326 | return 0; | |
2327 | } | |
2328 | ||
dc108b7a RH |
2329 | /* Blocks A and B are to be merged into a single block A. The insns |
2330 | are already contiguous, hence `nomove'. */ | |
2331 | ||
2332 | void | |
2333 | merge_blocks_nomove (a, b) | |
2334 | basic_block a, b; | |
2335 | { | |
2336 | edge e; | |
2337 | rtx b_head, b_end, a_end; | |
2338 | rtx del_first = NULL_RTX, del_last = NULL_RTX; | |
2339 | int b_empty = 0; | |
2340 | ||
2341 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
2342 | b_head = b->head; | |
2343 | b_end = b->end; | |
2344 | if (GET_CODE (b_head) == CODE_LABEL) | |
2345 | { | |
2346 | /* Detect basic blocks with nothing but a label. This can happen | |
2347 | in particular at the end of a function. */ | |
2348 | if (b_head == b_end) | |
2349 | b_empty = 1; | |
2350 | del_first = del_last = b_head; | |
2351 | b_head = NEXT_INSN (b_head); | |
2352 | } | |
2353 | ||
2354 | /* Delete the basic block note. */ | |
589ca5cb | 2355 | if (NOTE_INSN_BASIC_BLOCK_P (b_head)) |
dc108b7a RH |
2356 | { |
2357 | if (b_head == b_end) | |
2358 | b_empty = 1; | |
2359 | if (! del_last) | |
2360 | del_first = b_head; | |
2361 | del_last = b_head; | |
2362 | b_head = NEXT_INSN (b_head); | |
2363 | } | |
2364 | ||
2365 | /* If there was a jump out of A, delete it. */ | |
2366 | a_end = a->end; | |
2367 | if (GET_CODE (a_end) == JUMP_INSN) | |
2368 | { | |
2369 | rtx prev; | |
2370 | ||
8416f80a | 2371 | for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev)) |
7171b491 RH |
2372 | if (GET_CODE (prev) != NOTE |
2373 | || NOTE_LINE_NUMBER (prev) == NOTE_INSN_BASIC_BLOCK | |
2374 | || prev == a->head) | |
8416f80a | 2375 | break; |
dc108b7a RH |
2376 | |
2377 | del_first = a_end; | |
2378 | ||
2379 | #ifdef HAVE_cc0 | |
2380 | /* If this was a conditional jump, we need to also delete | |
2381 | the insn that set cc0. */ | |
2382 | if (prev && sets_cc0_p (prev)) | |
2383 | { | |
c9bacfdb | 2384 | rtx tmp = prev; |
dc108b7a RH |
2385 | prev = prev_nonnote_insn (prev); |
2386 | if (!prev) | |
2387 | prev = a->head; | |
2388 | del_first = tmp; | |
2389 | } | |
2390 | #endif | |
2391 | ||
2392 | a_end = prev; | |
2393 | } | |
abb9a4c5 RH |
2394 | else if (GET_CODE (NEXT_INSN (a_end)) == BARRIER) |
2395 | del_first = NEXT_INSN (a_end); | |
dc108b7a RH |
2396 | |
2397 | /* Delete everything marked above as well as crap that might be | |
2398 | hanging out between the two blocks. */ | |
2399 | flow_delete_insn_chain (del_first, del_last); | |
2400 | ||
2401 | /* Normally there should only be one successor of A and that is B, but | |
2402 | partway though the merge of blocks for conditional_execution we'll | |
2403 | be merging a TEST block with THEN and ELSE successors. Free the | |
2404 | whole lot of them and hope the caller knows what they're doing. */ | |
2405 | while (a->succ) | |
2406 | remove_edge (a->succ); | |
2407 | ||
2408 | /* Adjust the edges out of B for the new owner. */ | |
c9bacfdb | 2409 | for (e = b->succ; e; e = e->succ_next) |
dc108b7a RH |
2410 | e->src = a; |
2411 | a->succ = b->succ; | |
2412 | ||
2413 | /* B hasn't quite yet ceased to exist. Attempt to prevent mishap. */ | |
2414 | b->pred = b->succ = NULL; | |
2415 | ||
2416 | /* Reassociate the insns of B with A. */ | |
2417 | if (!b_empty) | |
2418 | { | |
2419 | if (basic_block_for_insn) | |
2420 | { | |
2421 | BLOCK_FOR_INSN (b_head) = a; | |
2422 | while (b_head != b_end) | |
2423 | { | |
2424 | b_head = NEXT_INSN (b_head); | |
2425 | BLOCK_FOR_INSN (b_head) = a; | |
2426 | } | |
2427 | } | |
2428 | a_end = b_end; | |
2429 | } | |
2430 | a->end = a_end; | |
2431 | ||
2432 | expunge_block (b); | |
2433 | } | |
2434 | ||
558389e3 JL |
2435 | /* Blocks A and B are to be merged into a single block. A has no incoming |
2436 | fallthru edge, so it can be moved before B without adding or modifying | |
2437 | any jumps (aside from the jump from A to B). */ | |
2438 | ||
2439 | static int | |
336a6399 | 2440 | merge_blocks_move_predecessor_nojumps (a, b) |
558389e3 JL |
2441 | basic_block a, b; |
2442 | { | |
93cba993 | 2443 | rtx start, end, barrier; |
ee7b8369 | 2444 | int index; |
558389e3 JL |
2445 | |
2446 | start = a->head; | |
2447 | end = a->end; | |
558389e3 | 2448 | |
558389e3 | 2449 | barrier = next_nonnote_insn (end); |
be1bb652 RH |
2450 | if (GET_CODE (barrier) != BARRIER) |
2451 | abort (); | |
2452 | flow_delete_insn (barrier); | |
558389e3 JL |
2453 | |
2454 | /* Move block and loop notes out of the chain so that we do not | |
2455 | disturb their order. | |
2456 | ||
2457 | ??? A better solution would be to squeeze out all the non-nested notes | |
2458 | and adjust the block trees appropriately. Even better would be to have | |
2459 | a tighter connection between block trees and rtl so that this is not | |
2460 | necessary. */ | |
2461 | start = squeeze_notes (start, end); | |
2462 | ||
2463 | /* Scramble the insn chain. */ | |
93cba993 RH |
2464 | if (end != PREV_INSN (b->head)) |
2465 | reorder_insns (start, end, PREV_INSN (b->head)); | |
558389e3 | 2466 | |
336a6399 RH |
2467 | if (rtl_dump_file) |
2468 | { | |
2469 | fprintf (rtl_dump_file, "Moved block %d before %d and merged.\n", | |
2470 | a->index, b->index); | |
2471 | } | |
2472 | ||
ee7b8369 RE |
2473 | /* Swap the records for the two blocks around. Although we are deleting B, |
2474 | A is now where B was and we want to compact the BB array from where | |
2475 | A used to be. */ | |
c9bacfdb KH |
2476 | BASIC_BLOCK (a->index) = b; |
2477 | BASIC_BLOCK (b->index) = a; | |
ee7b8369 RE |
2478 | index = a->index; |
2479 | a->index = b->index; | |
2480 | b->index = index; | |
c9bacfdb | 2481 | |
ee7b8369 RE |
2482 | /* Now blocks A and B are contiguous. Merge them. */ |
2483 | merge_blocks_nomove (a, b); | |
2484 | ||
558389e3 JL |
2485 | return 1; |
2486 | } | |
2487 | ||
2488 | /* Blocks A and B are to be merged into a single block. B has no outgoing | |
2489 | fallthru edge, so it can be moved after A without adding or modifying | |
2490 | any jumps (aside from the jump from A to B). */ | |
2491 | ||
2492 | static int | |
336a6399 | 2493 | merge_blocks_move_successor_nojumps (a, b) |
558389e3 JL |
2494 | basic_block a, b; |
2495 | { | |
93cba993 | 2496 | rtx start, end, barrier; |
558389e3 JL |
2497 | |
2498 | start = b->head; | |
2499 | end = b->end; | |
be1bb652 RH |
2500 | barrier = NEXT_INSN (end); |
2501 | ||
2502 | /* Recognize a jump table following block B. */ | |
2503 | if (GET_CODE (barrier) == CODE_LABEL | |
2504 | && NEXT_INSN (barrier) | |
2505 | && GET_CODE (NEXT_INSN (barrier)) == JUMP_INSN | |
2506 | && (GET_CODE (PATTERN (NEXT_INSN (barrier))) == ADDR_VEC | |
2507 | || GET_CODE (PATTERN (NEXT_INSN (barrier))) == ADDR_DIFF_VEC)) | |
2508 | { | |
2509 | end = NEXT_INSN (barrier); | |
2510 | barrier = NEXT_INSN (end); | |
2511 | } | |
558389e3 | 2512 | |
be1bb652 RH |
2513 | /* There had better have been a barrier there. Delete it. */ |
2514 | if (GET_CODE (barrier) != BARRIER) | |
2515 | abort (); | |
2516 | flow_delete_insn (barrier); | |
558389e3 JL |
2517 | |
2518 | /* Move block and loop notes out of the chain so that we do not | |
2519 | disturb their order. | |
2520 | ||
2521 | ??? A better solution would be to squeeze out all the non-nested notes | |
2522 | and adjust the block trees appropriately. Even better would be to have | |
2523 | a tighter connection between block trees and rtl so that this is not | |
2524 | necessary. */ | |
2525 | start = squeeze_notes (start, end); | |
2526 | ||
2527 | /* Scramble the insn chain. */ | |
93cba993 | 2528 | reorder_insns (start, end, a->end); |
558389e3 JL |
2529 | |
2530 | /* Now blocks A and B are contiguous. Merge them. */ | |
2531 | merge_blocks_nomove (a, b); | |
336a6399 RH |
2532 | |
2533 | if (rtl_dump_file) | |
2534 | { | |
2535 | fprintf (rtl_dump_file, "Moved block %d after %d and merged.\n", | |
2536 | b->index, a->index); | |
2537 | } | |
2538 | ||
558389e3 JL |
2539 | return 1; |
2540 | } | |
2541 | ||
c9bacfdb | 2542 | /* Attempt to merge basic blocks that are potentially non-adjacent. |
e881bb1b | 2543 | Return true iff the attempt succeeded. */ |
dc2ede84 | 2544 | |
dc2ede84 | 2545 | static int |
e881bb1b RH |
2546 | merge_blocks (e, b, c) |
2547 | edge e; | |
2548 | basic_block b, c; | |
dc2ede84 | 2549 | { |
be1bb652 RH |
2550 | /* If C has a tail recursion label, do not merge. There is no |
2551 | edge recorded from the call_placeholder back to this label, as | |
2552 | that would make optimize_sibling_and_tail_recursive_calls more | |
2553 | complex for no gain. */ | |
2554 | if (GET_CODE (c->head) == CODE_LABEL | |
2555 | && tail_recursion_label_p (c->head)) | |
2556 | return 0; | |
2557 | ||
e881bb1b | 2558 | /* If B has a fallthru edge to C, no need to move anything. */ |
336a6399 | 2559 | if (e->flags & EDGE_FALLTHRU) |
e881bb1b | 2560 | { |
336a6399 | 2561 | merge_blocks_nomove (b, c); |
558389e3 | 2562 | |
336a6399 RH |
2563 | if (rtl_dump_file) |
2564 | { | |
2565 | fprintf (rtl_dump_file, "Merged %d and %d without moving.\n", | |
2566 | b->index, c->index); | |
2567 | } | |
e881bb1b | 2568 | |
336a6399 RH |
2569 | return 1; |
2570 | } | |
2571 | else | |
2572 | { | |
2573 | edge tmp_edge; | |
2574 | basic_block d; | |
2575 | int c_has_outgoing_fallthru; | |
2576 | int b_has_incoming_fallthru; | |
e881bb1b | 2577 | |
336a6399 RH |
2578 | /* We must make sure to not munge nesting of exception regions, |
2579 | lexical blocks, and loop notes. | |
c9bacfdb | 2580 | |
336a6399 RH |
2581 | The first is taken care of by requiring that the active eh |
2582 | region at the end of one block always matches the active eh | |
2583 | region at the beginning of the next block. | |
c9bacfdb | 2584 | |
336a6399 | 2585 | The later two are taken care of by squeezing out all the notes. */ |
c9bacfdb | 2586 | |
336a6399 RH |
2587 | /* ??? A throw/catch edge (or any abnormal edge) should be rarely |
2588 | executed and we may want to treat blocks which have two out | |
2589 | edges, one normal, one abnormal as only having one edge for | |
2590 | block merging purposes. */ | |
558389e3 | 2591 | |
c9bacfdb | 2592 | for (tmp_edge = c->succ; tmp_edge; tmp_edge = tmp_edge->succ_next) |
558389e3 JL |
2593 | if (tmp_edge->flags & EDGE_FALLTHRU) |
2594 | break; | |
2595 | c_has_outgoing_fallthru = (tmp_edge != NULL); | |
2596 | ||
c9bacfdb | 2597 | for (tmp_edge = b->pred; tmp_edge; tmp_edge = tmp_edge->pred_next) |
558389e3 JL |
2598 | if (tmp_edge->flags & EDGE_FALLTHRU) |
2599 | break; | |
2600 | b_has_incoming_fallthru = (tmp_edge != NULL); | |
2601 | ||
336a6399 RH |
2602 | /* If B does not have an incoming fallthru, and the exception regions |
2603 | match, then it can be moved immediately before C without introducing | |
ff54d46b JL |
2604 | or modifying jumps. |
2605 | ||
2606 | C can not be the first block, so we do not have to worry about | |
2607 | accessing a non-existent block. */ | |
336a6399 RH |
2608 | d = BASIC_BLOCK (c->index - 1); |
2609 | if (! b_has_incoming_fallthru | |
2610 | && d->eh_end == b->eh_beg | |
2611 | && b->eh_end == c->eh_beg) | |
2612 | return merge_blocks_move_predecessor_nojumps (b, c); | |
2613 | ||
2614 | /* Otherwise, we're going to try to move C after B. Make sure the | |
ff54d46b JL |
2615 | exception regions match. |
2616 | ||
2617 | If B is the last basic block, then we must not try to access the | |
2618 | block structure for block B + 1. Luckily in that case we do not | |
2619 | need to worry about matching exception regions. */ | |
2620 | d = (b->index + 1 < n_basic_blocks ? BASIC_BLOCK (b->index + 1) : NULL); | |
336a6399 | 2621 | if (b->eh_end == c->eh_beg |
ff54d46b | 2622 | && (d == NULL || c->eh_end == d->eh_beg)) |
336a6399 RH |
2623 | { |
2624 | /* If C does not have an outgoing fallthru, then it can be moved | |
2625 | immediately after B without introducing or modifying jumps. */ | |
2626 | if (! c_has_outgoing_fallthru) | |
2627 | return merge_blocks_move_successor_nojumps (b, c); | |
2628 | ||
2629 | /* Otherwise, we'll need to insert an extra jump, and possibly | |
2630 | a new block to contain it. */ | |
2631 | /* ??? Not implemented yet. */ | |
2632 | } | |
558389e3 | 2633 | |
336a6399 | 2634 | return 0; |
e881bb1b | 2635 | } |
336a6399 | 2636 | } |
dc2ede84 | 2637 | |
336a6399 | 2638 | /* Top level driver for merge_blocks. */ |
421382ac | 2639 | |
336a6399 RH |
2640 | static void |
2641 | try_merge_blocks () | |
2642 | { | |
2643 | int i; | |
2644 | ||
2645 | /* Attempt to merge blocks as made possible by edge removal. If a block | |
c9bacfdb | 2646 | has only one successor, and the successor has only one predecessor, |
336a6399 RH |
2647 | they may be combined. */ |
2648 | ||
c9bacfdb | 2649 | for (i = 0; i < n_basic_blocks;) |
336a6399 RH |
2650 | { |
2651 | basic_block c, b = BASIC_BLOCK (i); | |
2652 | edge s; | |
2653 | ||
2654 | /* A loop because chains of blocks might be combineable. */ | |
2655 | while ((s = b->succ) != NULL | |
2656 | && s->succ_next == NULL | |
2657 | && (s->flags & EDGE_EH) == 0 | |
2658 | && (c = s->dest) != EXIT_BLOCK_PTR | |
2659 | && c->pred->pred_next == NULL | |
2660 | /* If the jump insn has side effects, we can't kill the edge. */ | |
2661 | && (GET_CODE (b->end) != JUMP_INSN | |
2662 | || onlyjump_p (b->end)) | |
2663 | && merge_blocks (s, b, c)) | |
2664 | continue; | |
2665 | ||
2666 | /* Don't get confused by the index shift caused by deleting blocks. */ | |
2667 | i = b->index + 1; | |
2668 | } | |
e881bb1b | 2669 | } |
421382ac | 2670 | |
5568fb48 RH |
2671 | /* The given edge should potentially be a fallthru edge. If that is in |
2672 | fact true, delete the jump and barriers that are in the way. */ | |
e881bb1b | 2673 | |
dc108b7a | 2674 | void |
e881bb1b RH |
2675 | tidy_fallthru_edge (e, b, c) |
2676 | edge e; | |
2677 | basic_block b, c; | |
2678 | { | |
eeea333e | 2679 | rtx q; |
e881bb1b RH |
2680 | |
2681 | /* ??? In a late-running flow pass, other folks may have deleted basic | |
2682 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
2683 | and the target label. They ought to be chastized and fixed. | |
2684 | ||
eeea333e RH |
2685 | We can also wind up with a sequence of undeletable labels between |
2686 | one block and the next. | |
dc2ede84 | 2687 | |
eeea333e RH |
2688 | So search through a sequence of barriers, labels, and notes for |
2689 | the head of block C and assert that we really do fall through. */ | |
421382ac | 2690 | |
eeea333e | 2691 | if (next_real_insn (b->end) != next_real_insn (PREV_INSN (c->head))) |
e881bb1b | 2692 | return; |
421382ac | 2693 | |
e881bb1b RH |
2694 | /* Remove what will soon cease being the jump insn from the source block. |
2695 | If block B consisted only of this single jump, turn it into a deleted | |
2696 | note. */ | |
2697 | q = b->end; | |
56aba4a8 | 2698 | if (GET_CODE (q) == JUMP_INSN |
7f1c097d JH |
2699 | && onlyjump_p (q) |
2700 | && (any_uncondjump_p (q) | |
56aba4a8 | 2701 | || (b->succ == e && e->succ_next == NULL))) |
421382ac | 2702 | { |
86a1db60 RH |
2703 | #ifdef HAVE_cc0 |
2704 | /* If this was a conditional jump, we need to also delete | |
2705 | the insn that set cc0. */ | |
7f1c097d | 2706 | if (any_condjump_p (q) && sets_cc0_p (PREV_INSN (q))) |
86a1db60 RH |
2707 | q = PREV_INSN (q); |
2708 | #endif | |
2709 | ||
e881bb1b RH |
2710 | if (b->head == q) |
2711 | { | |
2712 | PUT_CODE (q, NOTE); | |
2713 | NOTE_LINE_NUMBER (q) = NOTE_INSN_DELETED; | |
2714 | NOTE_SOURCE_FILE (q) = 0; | |
2715 | } | |
e3f6ee23 | 2716 | else |
b578dbd7 RH |
2717 | q = PREV_INSN (q); |
2718 | ||
2719 | b->end = q; | |
421382ac | 2720 | } |
421382ac | 2721 | |
e881bb1b | 2722 | /* Selectively unlink the sequence. */ |
86a1db60 | 2723 | if (q != PREV_INSN (c->head)) |
5aabad00 | 2724 | flow_delete_insn_chain (NEXT_INSN (q), PREV_INSN (c->head)); |
b7f7462b | 2725 | |
e881bb1b RH |
2726 | e->flags |= EDGE_FALLTHRU; |
2727 | } | |
dc2ede84 | 2728 | |
5568fb48 RH |
2729 | /* Fix up edges that now fall through, or rather should now fall through |
2730 | but previously required a jump around now deleted blocks. Simplify | |
2731 | the search by only examining blocks numerically adjacent, since this | |
2732 | is how find_basic_blocks created them. */ | |
2733 | ||
2734 | static void | |
2735 | tidy_fallthru_edges () | |
2736 | { | |
2737 | int i; | |
2738 | ||
2739 | for (i = 1; i < n_basic_blocks; ++i) | |
2740 | { | |
2741 | basic_block b = BASIC_BLOCK (i - 1); | |
2742 | basic_block c = BASIC_BLOCK (i); | |
2743 | edge s; | |
2744 | ||
2745 | /* We care about simple conditional or unconditional jumps with | |
2746 | a single successor. | |
2747 | ||
2748 | If we had a conditional branch to the next instruction when | |
2749 | find_basic_blocks was called, then there will only be one | |
2750 | out edge for the block which ended with the conditional | |
2751 | branch (since we do not create duplicate edges). | |
2752 | ||
2753 | Furthermore, the edge will be marked as a fallthru because we | |
2754 | merge the flags for the duplicate edges. So we do not want to | |
2755 | check that the edge is not a FALLTHRU edge. */ | |
2756 | if ((s = b->succ) != NULL | |
2757 | && s->succ_next == NULL | |
2758 | && s->dest == c | |
2759 | /* If the jump insn has side effects, we can't tidy the edge. */ | |
2760 | && (GET_CODE (b->end) != JUMP_INSN | |
2761 | || onlyjump_p (b->end))) | |
2762 | tidy_fallthru_edge (s, b, c); | |
2763 | } | |
2764 | } | |
d7429b6a | 2765 | \f |
5ece9746 | 2766 | /* Perform data flow analysis. |
7f8a79ba RH |
2767 | F is the first insn of the function; FLAGS is a set of PROP_* flags |
2768 | to be used in accumulating flow info. */ | |
5ece9746 JL |
2769 | |
2770 | void | |
7f8a79ba | 2771 | life_analysis (f, file, flags) |
5ece9746 | 2772 | rtx f; |
5ece9746 | 2773 | FILE *file; |
7f8a79ba | 2774 | int flags; |
5ece9746 | 2775 | { |
5ece9746 | 2776 | #ifdef ELIMINABLE_REGS |
47ee9bcb | 2777 | register int i; |
5ece9746 JL |
2778 | static struct {int from, to; } eliminables[] = ELIMINABLE_REGS; |
2779 | #endif | |
4e872036 | 2780 | |
5ece9746 JL |
2781 | /* Record which registers will be eliminated. We use this in |
2782 | mark_used_regs. */ | |
2783 | ||
2784 | CLEAR_HARD_REG_SET (elim_reg_set); | |
2785 | ||
2786 | #ifdef ELIMINABLE_REGS | |
b6a1cbae | 2787 | for (i = 0; i < (int) ARRAY_SIZE (eliminables); i++) |
5ece9746 JL |
2788 | SET_HARD_REG_BIT (elim_reg_set, eliminables[i].from); |
2789 | #else | |
2790 | SET_HARD_REG_BIT (elim_reg_set, FRAME_POINTER_REGNUM); | |
2791 | #endif | |
2792 | ||
d29c259b | 2793 | if (! optimize) |
b2262f4a | 2794 | flags &= ~(PROP_LOG_LINKS | PROP_AUTOINC); |
7790df19 | 2795 | |
3ea8083f JL |
2796 | /* The post-reload life analysis have (on a global basis) the same |
2797 | registers live as was computed by reload itself. elimination | |
2798 | Otherwise offsets and such may be incorrect. | |
2799 | ||
2800 | Reload will make some registers as live even though they do not | |
c9bacfdb | 2801 | appear in the rtl. |
61f286b6 RE |
2802 | |
2803 | We don't want to create new auto-incs after reload, since they | |
2804 | are unlikely to be useful and can cause problems with shared | |
2805 | stack slots. */ | |
3ea8083f | 2806 | if (reload_completed) |
61f286b6 | 2807 | flags &= ~(PROP_REG_INFO | PROP_AUTOINC); |
3ea8083f | 2808 | |
7f8a79ba | 2809 | /* We want alias analysis information for local dead store elimination. */ |
b2262f4a | 2810 | if (optimize && (flags & PROP_SCAN_DEAD_CODE)) |
7f8a79ba RH |
2811 | init_alias_analysis (); |
2812 | ||
3ea8083f JL |
2813 | /* Always remove no-op moves. Do this before other processing so |
2814 | that we don't have to keep re-scanning them. */ | |
2815 | delete_noop_moves (f); | |
2816 | ||
2817 | /* Some targets can emit simpler epilogues if they know that sp was | |
2818 | not ever modified during the function. After reload, of course, | |
2819 | we've already emitted the epilogue so there's no sense searching. */ | |
7790df19 | 2820 | if (! reload_completed) |
3ea8083f | 2821 | notice_stack_pointer_modification (f); |
c9bacfdb | 2822 | |
3ea8083f JL |
2823 | /* Allocate and zero out data structures that will record the |
2824 | data from lifetime analysis. */ | |
2825 | allocate_reg_life_data (); | |
2826 | allocate_bb_life_data (); | |
7790df19 | 2827 | |
3ea8083f JL |
2828 | /* Find the set of registers live on function exit. */ |
2829 | mark_regs_live_at_end (EXIT_BLOCK_PTR->global_live_at_start); | |
2830 | ||
2831 | /* "Update" life info from zero. It'd be nice to begin the | |
2832 | relaxation with just the exit and noreturn blocks, but that set | |
2833 | is not immediately handy. */ | |
c8082519 RH |
2834 | |
2835 | if (flags & PROP_REG_INFO) | |
c9bacfdb | 2836 | memset (regs_ever_live, 0, sizeof (regs_ever_live)); |
693d9e2f | 2837 | update_life_info (NULL, UPDATE_LIFE_GLOBAL, flags); |
3ea8083f JL |
2838 | |
2839 | /* Clean up. */ | |
b2262f4a | 2840 | if (optimize && (flags & PROP_SCAN_DEAD_CODE)) |
7f8a79ba | 2841 | end_alias_analysis (); |
db3a887b | 2842 | |
5ece9746 JL |
2843 | if (file) |
2844 | dump_flow_info (file); | |
2845 | ||
2846 | free_basic_block_vars (1); | |
2847 | } | |
2848 | ||
d3a923ee RH |
2849 | /* A subroutine of verify_wide_reg, called through for_each_rtx. |
2850 | Search for REGNO. If found, abort if it is not wider than word_mode. */ | |
2851 | ||
2852 | static int | |
2853 | verify_wide_reg_1 (px, pregno) | |
2854 | rtx *px; | |
2855 | void *pregno; | |
2856 | { | |
2857 | rtx x = *px; | |
770ae6cc | 2858 | unsigned int regno = *(int *) pregno; |
d3a923ee RH |
2859 | |
2860 | if (GET_CODE (x) == REG && REGNO (x) == regno) | |
2861 | { | |
2862 | if (GET_MODE_BITSIZE (GET_MODE (x)) <= BITS_PER_WORD) | |
2863 | abort (); | |
2864 | return 1; | |
2865 | } | |
2866 | return 0; | |
2867 | } | |
2868 | ||
2869 | /* A subroutine of verify_local_live_at_start. Search through insns | |
2870 | between HEAD and END looking for register REGNO. */ | |
2871 | ||
2872 | static void | |
2873 | verify_wide_reg (regno, head, end) | |
2874 | int regno; | |
2875 | rtx head, end; | |
2876 | { | |
2877 | while (1) | |
2878 | { | |
2c3c49de | 2879 | if (INSN_P (head) |
d3a923ee RH |
2880 | && for_each_rtx (&PATTERN (head), verify_wide_reg_1, ®no)) |
2881 | return; | |
2882 | if (head == end) | |
2883 | break; | |
2884 | head = NEXT_INSN (head); | |
2885 | } | |
2886 | ||
2887 | /* We didn't find the register at all. Something's way screwy. */ | |
f9b697bf BS |
2888 | if (rtl_dump_file) |
2889 | fprintf (rtl_dump_file, "Aborting in verify_wide_reg; reg %d\n", regno); | |
2890 | print_rtl_and_abort (); | |
d3a923ee RH |
2891 | } |
2892 | ||
2893 | /* A subroutine of update_life_info. Verify that there are no untoward | |
2894 | changes in live_at_start during a local update. */ | |
2895 | ||
2896 | static void | |
2897 | verify_local_live_at_start (new_live_at_start, bb) | |
2898 | regset new_live_at_start; | |
2899 | basic_block bb; | |
2900 | { | |
2901 | if (reload_completed) | |
2902 | { | |
2903 | /* After reload, there are no pseudos, nor subregs of multi-word | |
2904 | registers. The regsets should exactly match. */ | |
2905 | if (! REG_SET_EQUAL_P (new_live_at_start, bb->global_live_at_start)) | |
f9b697bf BS |
2906 | { |
2907 | if (rtl_dump_file) | |
2908 | { | |
2909 | fprintf (rtl_dump_file, | |
2910 | "live_at_start mismatch in bb %d, aborting\n", | |
2911 | bb->index); | |
2912 | debug_bitmap_file (rtl_dump_file, bb->global_live_at_start); | |
2913 | debug_bitmap_file (rtl_dump_file, new_live_at_start); | |
2914 | } | |
2915 | print_rtl_and_abort (); | |
2916 | } | |
d3a923ee RH |
2917 | } |
2918 | else | |
2919 | { | |
2920 | int i; | |
2921 | ||
2922 | /* Find the set of changed registers. */ | |
2923 | XOR_REG_SET (new_live_at_start, bb->global_live_at_start); | |
2924 | ||
2925 | EXECUTE_IF_SET_IN_REG_SET (new_live_at_start, 0, i, | |
2926 | { | |
c762163e | 2927 | /* No registers should die. */ |
d3a923ee | 2928 | if (REGNO_REG_SET_P (bb->global_live_at_start, i)) |
f9b697bf BS |
2929 | { |
2930 | if (rtl_dump_file) | |
2931 | fprintf (rtl_dump_file, | |
2932 | "Register %d died unexpectedly in block %d\n", i, | |
2933 | bb->index); | |
2934 | print_rtl_and_abort (); | |
2935 | } | |
2936 | ||
c762163e R |
2937 | /* Verify that the now-live register is wider than word_mode. */ |
2938 | verify_wide_reg (i, bb->head, bb->end); | |
d3a923ee RH |
2939 | }); |
2940 | } | |
2941 | } | |
2942 | ||
3ea8083f | 2943 | /* Updates life information starting with the basic blocks set in BLOCKS. |
693d9e2f | 2944 | If BLOCKS is null, consider it to be the universal set. |
c9bacfdb | 2945 | |
693d9e2f RH |
2946 | If EXTENT is UPDATE_LIFE_LOCAL, such as after splitting or peepholeing, |
2947 | we are only expecting local modifications to basic blocks. If we find | |
2948 | extra registers live at the beginning of a block, then we either killed | |
d3a923ee RH |
2949 | useful data, or we have a broken split that wants data not provided. |
2950 | If we find registers removed from live_at_start, that means we have | |
2951 | a broken peephole that is killing a register it shouldn't. | |
2952 | ||
2953 | ??? This is not true in one situation -- when a pre-reload splitter | |
2954 | generates subregs of a multi-word pseudo, current life analysis will | |
49c3bb12 RH |
2955 | lose the kill. So we _can_ have a pseudo go live. How irritating. |
2956 | ||
62828c00 RH |
2957 | Including PROP_REG_INFO does not properly refresh regs_ever_live |
2958 | unless the caller resets it to zero. */ | |
d3a923ee RH |
2959 | |
2960 | void | |
49c3bb12 | 2961 | update_life_info (blocks, extent, prop_flags) |
d3a923ee | 2962 | sbitmap blocks; |
715e7fbc | 2963 | enum update_life_extent extent; |
49c3bb12 | 2964 | int prop_flags; |
d3a923ee RH |
2965 | { |
2966 | regset tmp; | |
ee25a7a5 | 2967 | regset_head tmp_head; |
d3a923ee RH |
2968 | int i; |
2969 | ||
ee25a7a5 | 2970 | tmp = INITIALIZE_REG_SET (tmp_head); |
d3a923ee RH |
2971 | |
2972 | /* For a global update, we go through the relaxation process again. */ | |
715e7fbc RH |
2973 | if (extent != UPDATE_LIFE_LOCAL) |
2974 | { | |
49c3bb12 RH |
2975 | calculate_global_regs_live (blocks, blocks, |
2976 | prop_flags & PROP_SCAN_DEAD_CODE); | |
715e7fbc RH |
2977 | |
2978 | /* If asked, remove notes from the blocks we'll update. */ | |
2979 | if (extent == UPDATE_LIFE_GLOBAL_RM_NOTES) | |
2980 | count_or_remove_death_notes (blocks, 1); | |
2981 | } | |
d3a923ee | 2982 | |
693d9e2f | 2983 | if (blocks) |
d3a923ee | 2984 | { |
693d9e2f RH |
2985 | EXECUTE_IF_SET_IN_SBITMAP (blocks, 0, i, |
2986 | { | |
2987 | basic_block bb = BASIC_BLOCK (i); | |
2988 | ||
2989 | COPY_REG_SET (tmp, bb->global_live_at_end); | |
7dfc0fbe | 2990 | propagate_block (bb, tmp, NULL, NULL, prop_flags); |
693d9e2f RH |
2991 | |
2992 | if (extent == UPDATE_LIFE_LOCAL) | |
2993 | verify_local_live_at_start (tmp, bb); | |
2994 | }); | |
2995 | } | |
2996 | else | |
2997 | { | |
2998 | for (i = n_basic_blocks - 1; i >= 0; --i) | |
2999 | { | |
3000 | basic_block bb = BASIC_BLOCK (i); | |
d3a923ee | 3001 | |
693d9e2f | 3002 | COPY_REG_SET (tmp, bb->global_live_at_end); |
7dfc0fbe | 3003 | propagate_block (bb, tmp, NULL, NULL, prop_flags); |
d3a923ee | 3004 | |
693d9e2f RH |
3005 | if (extent == UPDATE_LIFE_LOCAL) |
3006 | verify_local_live_at_start (tmp, bb); | |
3007 | } | |
3008 | } | |
d3a923ee RH |
3009 | |
3010 | FREE_REG_SET (tmp); | |
3ea8083f JL |
3011 | |
3012 | if (prop_flags & PROP_REG_INFO) | |
3013 | { | |
3014 | /* The only pseudos that are live at the beginning of the function | |
3015 | are those that were not set anywhere in the function. local-alloc | |
3016 | doesn't know how to handle these correctly, so mark them as not | |
3017 | local to any one basic block. */ | |
3018 | EXECUTE_IF_SET_IN_REG_SET (ENTRY_BLOCK_PTR->global_live_at_end, | |
3019 | FIRST_PSEUDO_REGISTER, i, | |
3020 | { REG_BASIC_BLOCK (i) = REG_BLOCK_GLOBAL; }); | |
3021 | ||
c9bacfdb | 3022 | /* We have a problem with any pseudoreg that lives across the setjmp. |
3ea8083f JL |
3023 | ANSI says that if a user variable does not change in value between |
3024 | the setjmp and the longjmp, then the longjmp preserves it. This | |
3025 | includes longjmp from a place where the pseudo appears dead. | |
3026 | (In principle, the value still exists if it is in scope.) | |
3027 | If the pseudo goes in a hard reg, some other value may occupy | |
3028 | that hard reg where this pseudo is dead, thus clobbering the pseudo. | |
3029 | Conclusion: such a pseudo must not go in a hard reg. */ | |
3030 | EXECUTE_IF_SET_IN_REG_SET (regs_live_at_setjmp, | |
3031 | FIRST_PSEUDO_REGISTER, i, | |
3032 | { | |
3033 | if (regno_reg_rtx[i] != 0) | |
3034 | { | |
3035 | REG_LIVE_LENGTH (i) = -1; | |
3036 | REG_BASIC_BLOCK (i) = REG_BLOCK_UNKNOWN; | |
3037 | } | |
3038 | }); | |
3039 | } | |
d3a923ee RH |
3040 | } |
3041 | ||
5ece9746 JL |
3042 | /* Free the variables allocated by find_basic_blocks. |
3043 | ||
e881bb1b | 3044 | KEEP_HEAD_END_P is non-zero if basic_block_info is not to be freed. */ |
5ece9746 JL |
3045 | |
3046 | void | |
3047 | free_basic_block_vars (keep_head_end_p) | |
3048 | int keep_head_end_p; | |
3049 | { | |
e881bb1b | 3050 | if (basic_block_for_insn) |
5ece9746 | 3051 | { |
e881bb1b RH |
3052 | VARRAY_FREE (basic_block_for_insn); |
3053 | basic_block_for_insn = NULL; | |
5ece9746 JL |
3054 | } |
3055 | ||
e881bb1b | 3056 | if (! keep_head_end_p) |
5ece9746 | 3057 | { |
e881bb1b RH |
3058 | clear_edges (); |
3059 | VARRAY_FREE (basic_block_info); | |
3060 | n_basic_blocks = 0; | |
359da67d RH |
3061 | |
3062 | ENTRY_BLOCK_PTR->aux = NULL; | |
3063 | ENTRY_BLOCK_PTR->global_live_at_end = NULL; | |
3064 | EXIT_BLOCK_PTR->aux = NULL; | |
3065 | EXIT_BLOCK_PTR->global_live_at_start = NULL; | |
5ece9746 JL |
3066 | } |
3067 | } | |
3068 | ||
dc2ede84 | 3069 | /* Return nonzero if the destination of SET equals the source. */ |
c9bacfdb | 3070 | |
dc2ede84 BS |
3071 | static int |
3072 | set_noop_p (set) | |
3073 | rtx set; | |
3074 | { | |
3075 | rtx src = SET_SRC (set); | |
3076 | rtx dst = SET_DEST (set); | |
3ea8083f JL |
3077 | |
3078 | if (GET_CODE (src) == SUBREG && GET_CODE (dst) == SUBREG) | |
3079 | { | |
3080 | if (SUBREG_WORD (src) != SUBREG_WORD (dst)) | |
3081 | return 0; | |
3082 | src = SUBREG_REG (src); | |
3083 | dst = SUBREG_REG (dst); | |
3084 | } | |
3085 | ||
3086 | return (GET_CODE (src) == REG && GET_CODE (dst) == REG | |
3087 | && REGNO (src) == REGNO (dst)); | |
dc2ede84 BS |
3088 | } |
3089 | ||
3090 | /* Return nonzero if an insn consists only of SETs, each of which only sets a | |
3091 | value to itself. */ | |
c9bacfdb | 3092 | |
dc2ede84 BS |
3093 | static int |
3094 | noop_move_p (insn) | |
3095 | rtx insn; | |
3096 | { | |
3097 | rtx pat = PATTERN (insn); | |
3098 | ||
3099 | /* Insns carrying these notes are useful later on. */ | |
3100 | if (find_reg_note (insn, REG_EQUAL, NULL_RTX)) | |
3101 | return 0; | |
3102 | ||
3103 | if (GET_CODE (pat) == SET && set_noop_p (pat)) | |
3104 | return 1; | |
3105 | ||
3106 | if (GET_CODE (pat) == PARALLEL) | |
3107 | { | |
3108 | int i; | |
3109 | /* If nothing but SETs of registers to themselves, | |
3110 | this insn can also be deleted. */ | |
3111 | for (i = 0; i < XVECLEN (pat, 0); i++) | |
3112 | { | |
3113 | rtx tem = XVECEXP (pat, 0, i); | |
3114 | ||
3115 | if (GET_CODE (tem) == USE | |
3116 | || GET_CODE (tem) == CLOBBER) | |
3117 | continue; | |
3118 | ||
3119 | if (GET_CODE (tem) != SET || ! set_noop_p (tem)) | |
3120 | return 0; | |
3121 | } | |
3122 | ||
3123 | return 1; | |
3124 | } | |
3125 | return 0; | |
3126 | } | |
3127 | ||
3ea8083f JL |
3128 | /* Delete any insns that copy a register to itself. */ |
3129 | ||
3130 | static void | |
3131 | delete_noop_moves (f) | |
3132 | rtx f; | |
3133 | { | |
3134 | rtx insn; | |
3135 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
3136 | { | |
3137 | if (GET_CODE (insn) == INSN && noop_move_p (insn)) | |
3138 | { | |
3139 | PUT_CODE (insn, NOTE); | |
3140 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
3141 | NOTE_SOURCE_FILE (insn) = 0; | |
3142 | } | |
3143 | } | |
3144 | } | |
3145 | ||
3146 | /* Determine if the stack pointer is constant over the life of the function. | |
3147 | Only useful before prologues have been emitted. */ | |
3148 | ||
fdb8a883 | 3149 | static void |
3ea8083f | 3150 | notice_stack_pointer_modification_1 (x, pat, data) |
fdb8a883 JW |
3151 | rtx x; |
3152 | rtx pat ATTRIBUTE_UNUSED; | |
84832317 | 3153 | void *data ATTRIBUTE_UNUSED; |
fdb8a883 JW |
3154 | { |
3155 | if (x == stack_pointer_rtx | |
3156 | /* The stack pointer is only modified indirectly as the result | |
3157 | of a push until later in flow. See the comments in rtl.texi | |
3158 | regarding Embedded Side-Effects on Addresses. */ | |
3159 | || (GET_CODE (x) == MEM | |
3160 | && (GET_CODE (XEXP (x, 0)) == PRE_DEC | |
3161 | || GET_CODE (XEXP (x, 0)) == PRE_INC | |
3162 | || GET_CODE (XEXP (x, 0)) == POST_DEC | |
3163 | || GET_CODE (XEXP (x, 0)) == POST_INC) | |
3164 | && XEXP (XEXP (x, 0), 0) == stack_pointer_rtx)) | |
3165 | current_function_sp_is_unchanging = 0; | |
3166 | } | |
3167 | ||
dc2ede84 | 3168 | static void |
3ea8083f | 3169 | notice_stack_pointer_modification (f) |
dc2ede84 BS |
3170 | rtx f; |
3171 | { | |
3172 | rtx insn; | |
3ea8083f JL |
3173 | |
3174 | /* Assume that the stack pointer is unchanging if alloca hasn't | |
3175 | been used. */ | |
3176 | current_function_sp_is_unchanging = !current_function_calls_alloca; | |
3177 | if (! current_function_sp_is_unchanging) | |
3178 | return; | |
3179 | ||
dc2ede84 BS |
3180 | for (insn = f; insn; insn = NEXT_INSN (insn)) |
3181 | { | |
2c3c49de | 3182 | if (INSN_P (insn)) |
dc2ede84 | 3183 | { |
3ea8083f JL |
3184 | /* Check if insn modifies the stack pointer. */ |
3185 | note_stores (PATTERN (insn), notice_stack_pointer_modification_1, | |
3186 | NULL); | |
3187 | if (! current_function_sp_is_unchanging) | |
3188 | return; | |
dc2ede84 BS |
3189 | } |
3190 | } | |
3191 | } | |
3192 | ||
d3a923ee RH |
3193 | /* Mark a register in SET. Hard registers in large modes get all |
3194 | of their component registers set as well. */ | |
c9bacfdb | 3195 | |
d3a923ee | 3196 | static void |
c13fde05 | 3197 | mark_reg (reg, xset) |
d3a923ee | 3198 | rtx reg; |
c13fde05 | 3199 | void *xset; |
d3a923ee | 3200 | { |
c13fde05 | 3201 | regset set = (regset) xset; |
d3a923ee RH |
3202 | int regno = REGNO (reg); |
3203 | ||
c13fde05 RH |
3204 | if (GET_MODE (reg) == BLKmode) |
3205 | abort (); | |
3206 | ||
d3a923ee RH |
3207 | SET_REGNO_REG_SET (set, regno); |
3208 | if (regno < FIRST_PSEUDO_REGISTER) | |
3209 | { | |
3210 | int n = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
3211 | while (--n > 0) | |
3212 | SET_REGNO_REG_SET (set, regno + n); | |
3213 | } | |
3214 | } | |
3215 | ||
dc2ede84 BS |
3216 | /* Mark those regs which are needed at the end of the function as live |
3217 | at the end of the last basic block. */ | |
c9bacfdb | 3218 | |
dc2ede84 BS |
3219 | static void |
3220 | mark_regs_live_at_end (set) | |
3221 | regset set; | |
3222 | { | |
3223 | int i; | |
d3a923ee | 3224 | |
e881bb1b RH |
3225 | /* If exiting needs the right stack value, consider the stack pointer |
3226 | live at the end of the function. */ | |
d3a923ee RH |
3227 | if ((HAVE_epilogue && reload_completed) |
3228 | || ! EXIT_IGNORE_STACK | |
dc2ede84 BS |
3229 | || (! FRAME_POINTER_REQUIRED |
3230 | && ! current_function_calls_alloca | |
fdb8a883 JW |
3231 | && flag_omit_frame_pointer) |
3232 | || current_function_sp_is_unchanging) | |
e881bb1b RH |
3233 | { |
3234 | SET_REGNO_REG_SET (set, STACK_POINTER_REGNUM); | |
3235 | } | |
dc2ede84 | 3236 | |
e881bb1b | 3237 | /* Mark the frame pointer if needed at the end of the function. If |
dc2ede84 BS |
3238 | we end up eliminating it, it will be removed from the live list |
3239 | of each basic block by reload. */ | |
3240 | ||
e4b8a413 JW |
3241 | if (! reload_completed || frame_pointer_needed) |
3242 | { | |
3243 | SET_REGNO_REG_SET (set, FRAME_POINTER_REGNUM); | |
dc2ede84 | 3244 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
2a3e384f RH |
3245 | /* If they are different, also mark the hard frame pointer as live. */ |
3246 | if (! LOCAL_REGNO (HARD_FRAME_POINTER_REGNUM)) | |
3247 | SET_REGNO_REG_SET (set, HARD_FRAME_POINTER_REGNUM); | |
c9bacfdb | 3248 | #endif |
e4b8a413 | 3249 | } |
dc2ede84 | 3250 | |
d3a923ee RH |
3251 | #ifdef PIC_OFFSET_TABLE_REGNUM |
3252 | #ifndef PIC_OFFSET_TABLE_REG_CALL_CLOBBERED | |
3253 | /* Many architectures have a GP register even without flag_pic. | |
3254 | Assume the pic register is not in use, or will be handled by | |
3255 | other means, if it is not fixed. */ | |
3256 | if (fixed_regs[PIC_OFFSET_TABLE_REGNUM]) | |
3257 | SET_REGNO_REG_SET (set, PIC_OFFSET_TABLE_REGNUM); | |
3258 | #endif | |
3259 | #endif | |
3260 | ||
e881bb1b | 3261 | /* Mark all global registers, and all registers used by the epilogue |
dc2ede84 BS |
3262 | as being live at the end of the function since they may be |
3263 | referenced by our caller. */ | |
3264 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
2a3e384f | 3265 | if (global_regs[i] || EPILOGUE_USES (i)) |
dc2ede84 | 3266 | SET_REGNO_REG_SET (set, i); |
e881bb1b | 3267 | |
d3a923ee RH |
3268 | /* Mark all call-saved registers that we actaully used. */ |
3269 | if (HAVE_epilogue && reload_completed) | |
3270 | { | |
3271 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
2a3e384f | 3272 | if (regs_ever_live[i] && ! call_used_regs[i] && ! LOCAL_REGNO (i)) |
d3a923ee RH |
3273 | SET_REGNO_REG_SET (set, i); |
3274 | } | |
3275 | ||
3276 | /* Mark function return value. */ | |
c13fde05 | 3277 | diddle_return_value (mark_reg, set); |
dc2ede84 BS |
3278 | } |
3279 | ||
4e872036 AS |
3280 | /* Callback function for for_each_successor_phi. DATA is a regset. |
3281 | Sets the SRC_REGNO, the regno of the phi alternative for phi node | |
3282 | INSN, in the regset. */ | |
3283 | ||
3284 | static int | |
3285 | set_phi_alternative_reg (insn, dest_regno, src_regno, data) | |
3286 | rtx insn ATTRIBUTE_UNUSED; | |
3287 | int dest_regno ATTRIBUTE_UNUSED; | |
3288 | int src_regno; | |
3289 | void *data; | |
3290 | { | |
3291 | regset live = (regset) data; | |
3292 | SET_REGNO_REG_SET (live, src_regno); | |
3293 | return 0; | |
3294 | } | |
3295 | ||
d3a923ee | 3296 | /* Propagate global life info around the graph of basic blocks. Begin |
c9bacfdb | 3297 | considering blocks with their corresponding bit set in BLOCKS_IN. |
693d9e2f RH |
3298 | If BLOCKS_IN is null, consider it the universal set. |
3299 | ||
d3a923ee RH |
3300 | BLOCKS_OUT is set for every block that was changed. */ |
3301 | ||
3302 | static void | |
3303 | calculate_global_regs_live (blocks_in, blocks_out, flags) | |
3304 | sbitmap blocks_in, blocks_out; | |
3305 | int flags; | |
3306 | { | |
3307 | basic_block *queue, *qhead, *qtail, *qend; | |
3308 | regset tmp, new_live_at_end; | |
ee25a7a5 MM |
3309 | regset_head tmp_head; |
3310 | regset_head new_live_at_end_head; | |
d3a923ee RH |
3311 | int i; |
3312 | ||
ee25a7a5 MM |
3313 | tmp = INITIALIZE_REG_SET (tmp_head); |
3314 | new_live_at_end = INITIALIZE_REG_SET (new_live_at_end_head); | |
d3a923ee RH |
3315 | |
3316 | /* Create a worklist. Allocate an extra slot for ENTRY_BLOCK, and one | |
c9bacfdb | 3317 | because the `head == tail' style test for an empty queue doesn't |
d3a923ee | 3318 | work with a full queue. */ |
67289ea6 | 3319 | queue = (basic_block *) xmalloc ((n_basic_blocks + 2) * sizeof (*queue)); |
d3a923ee RH |
3320 | qtail = queue; |
3321 | qhead = qend = queue + n_basic_blocks + 2; | |
3322 | ||
3323 | /* Queue the blocks set in the initial mask. Do this in reverse block | |
c9bacfdb | 3324 | number order so that we are more likely for the first round to do |
d3a923ee | 3325 | useful work. We use AUX non-null to flag that the block is queued. */ |
693d9e2f | 3326 | if (blocks_in) |
d3a923ee | 3327 | { |
25e4379f MM |
3328 | /* Clear out the garbage that might be hanging out in bb->aux. */ |
3329 | for (i = n_basic_blocks - 1; i >= 0; --i) | |
3330 | BASIC_BLOCK (i)->aux = NULL; | |
3331 | ||
693d9e2f RH |
3332 | EXECUTE_IF_SET_IN_SBITMAP (blocks_in, 0, i, |
3333 | { | |
3334 | basic_block bb = BASIC_BLOCK (i); | |
3335 | *--qhead = bb; | |
3336 | bb->aux = bb; | |
3337 | }); | |
3338 | } | |
3339 | else | |
3340 | { | |
3341 | for (i = 0; i < n_basic_blocks; ++i) | |
3342 | { | |
3343 | basic_block bb = BASIC_BLOCK (i); | |
3344 | *--qhead = bb; | |
3345 | bb->aux = bb; | |
3346 | } | |
3347 | } | |
d3a923ee | 3348 | |
693d9e2f RH |
3349 | if (blocks_out) |
3350 | sbitmap_zero (blocks_out); | |
d3a923ee RH |
3351 | |
3352 | while (qhead != qtail) | |
3353 | { | |
3354 | int rescan, changed; | |
3355 | basic_block bb; | |
3356 | edge e; | |
3357 | ||
3358 | bb = *qhead++; | |
3359 | if (qhead == qend) | |
3360 | qhead = queue; | |
3361 | bb->aux = NULL; | |
3362 | ||
3363 | /* Begin by propogating live_at_start from the successor blocks. */ | |
3364 | CLEAR_REG_SET (new_live_at_end); | |
c9bacfdb | 3365 | for (e = bb->succ; e; e = e->succ_next) |
d3a923ee RH |
3366 | { |
3367 | basic_block sb = e->dest; | |
3368 | IOR_REG_SET (new_live_at_end, sb->global_live_at_start); | |
3369 | } | |
3370 | ||
39c39be9 RH |
3371 | /* Before reload, there are a few registers that must be forced |
3372 | live everywhere -- which might not already be the case for | |
3373 | blocks within infinite loops. */ | |
770a7feb | 3374 | if (! reload_completed) |
39c39be9 RH |
3375 | { |
3376 | /* The all-important stack pointer. */ | |
3377 | SET_REGNO_REG_SET (new_live_at_end, STACK_POINTER_REGNUM); | |
3378 | ||
3379 | /* Any reference to any pseudo before reload is a potential | |
3380 | reference of the frame pointer. */ | |
3381 | SET_REGNO_REG_SET (new_live_at_end, FRAME_POINTER_REGNUM); | |
3382 | ||
3383 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM | |
3384 | /* Pseudos with argument area equivalences may require | |
3385 | reloading via the argument pointer. */ | |
3386 | if (fixed_regs[ARG_POINTER_REGNUM]) | |
3387 | SET_REGNO_REG_SET (new_live_at_end, ARG_POINTER_REGNUM); | |
3388 | #endif | |
3389 | ||
3390 | #ifdef PIC_OFFSET_TABLE_REGNUM | |
3391 | /* Any constant, or pseudo with constant equivalences, may | |
3392 | require reloading from memory using the pic register. */ | |
3393 | if (fixed_regs[PIC_OFFSET_TABLE_REGNUM]) | |
3394 | SET_REGNO_REG_SET (new_live_at_end, PIC_OFFSET_TABLE_REGNUM); | |
3395 | #endif | |
3396 | } | |
770a7feb | 3397 | |
4e872036 AS |
3398 | /* Regs used in phi nodes are not included in |
3399 | global_live_at_start, since they are live only along a | |
3400 | particular edge. Set those regs that are live because of a | |
3401 | phi node alternative corresponding to this particular block. */ | |
1868a0d4 | 3402 | if (in_ssa_form) |
c9bacfdb | 3403 | for_each_successor_phi (bb, &set_phi_alternative_reg, |
1868a0d4 | 3404 | new_live_at_end); |
4e872036 | 3405 | |
d3a923ee RH |
3406 | if (bb == ENTRY_BLOCK_PTR) |
3407 | { | |
3408 | COPY_REG_SET (bb->global_live_at_end, new_live_at_end); | |
3409 | continue; | |
3410 | } | |
3411 | ||
c9bacfdb | 3412 | /* On our first pass through this block, we'll go ahead and continue. |
d3a923ee RH |
3413 | Recognize first pass by local_set NULL. On subsequent passes, we |
3414 | get to skip out early if live_at_end wouldn't have changed. */ | |
3415 | ||
3416 | if (bb->local_set == NULL) | |
3417 | { | |
1f8f4a0b | 3418 | bb->local_set = OBSTACK_ALLOC_REG_SET (&flow_obstack); |
7dfc0fbe | 3419 | bb->cond_local_set = OBSTACK_ALLOC_REG_SET (&flow_obstack); |
d3a923ee RH |
3420 | rescan = 1; |
3421 | } | |
3422 | else | |
3423 | { | |
3424 | /* If any bits were removed from live_at_end, we'll have to | |
3425 | rescan the block. This wouldn't be necessary if we had | |
3426 | precalculated local_live, however with PROP_SCAN_DEAD_CODE | |
4eb00163 | 3427 | local_live is really dependent on live_at_end. */ |
d3a923ee RH |
3428 | CLEAR_REG_SET (tmp); |
3429 | rescan = bitmap_operation (tmp, bb->global_live_at_end, | |
3430 | new_live_at_end, BITMAP_AND_COMPL); | |
3431 | ||
7dfc0fbe BS |
3432 | if (! rescan) |
3433 | { | |
3434 | /* If any of the registers in the new live_at_end set are | |
3435 | conditionally set in this basic block, we must rescan. | |
3436 | This is because conditional lifetimes at the end of the | |
3437 | block do not just take the live_at_end set into account, | |
3438 | but also the liveness at the start of each successor | |
3439 | block. We can miss changes in those sets if we only | |
3440 | compare the new live_at_end against the previous one. */ | |
3441 | CLEAR_REG_SET (tmp); | |
3442 | rescan = bitmap_operation (tmp, new_live_at_end, | |
3443 | bb->cond_local_set, BITMAP_AND); | |
3444 | } | |
3445 | ||
d3a923ee RH |
3446 | if (! rescan) |
3447 | { | |
3448 | /* Find the set of changed bits. Take this opportunity | |
3449 | to notice that this set is empty and early out. */ | |
3450 | CLEAR_REG_SET (tmp); | |
3451 | changed = bitmap_operation (tmp, bb->global_live_at_end, | |
3452 | new_live_at_end, BITMAP_XOR); | |
3453 | if (! changed) | |
3454 | continue; | |
3455 | ||
3456 | /* If any of the changed bits overlap with local_set, | |
3457 | we'll have to rescan the block. Detect overlap by | |
3458 | the AND with ~local_set turning off bits. */ | |
3459 | rescan = bitmap_operation (tmp, tmp, bb->local_set, | |
3460 | BITMAP_AND_COMPL); | |
3461 | } | |
3462 | } | |
3463 | ||
3464 | /* Let our caller know that BB changed enough to require its | |
3465 | death notes updated. */ | |
693d9e2f RH |
3466 | if (blocks_out) |
3467 | SET_BIT (blocks_out, bb->index); | |
d3a923ee RH |
3468 | |
3469 | if (! rescan) | |
3470 | { | |
3471 | /* Add to live_at_start the set of all registers in | |
3472 | new_live_at_end that aren't in the old live_at_end. */ | |
3473 | ||
3474 | bitmap_operation (tmp, new_live_at_end, bb->global_live_at_end, | |
3475 | BITMAP_AND_COMPL); | |
3476 | COPY_REG_SET (bb->global_live_at_end, new_live_at_end); | |
3477 | ||
3478 | changed = bitmap_operation (bb->global_live_at_start, | |
3479 | bb->global_live_at_start, | |
3480 | tmp, BITMAP_IOR); | |
3481 | if (! changed) | |
3482 | continue; | |
3483 | } | |
3484 | else | |
3485 | { | |
3486 | COPY_REG_SET (bb->global_live_at_end, new_live_at_end); | |
3487 | ||
3488 | /* Rescan the block insn by insn to turn (a copy of) live_at_end | |
3489 | into live_at_start. */ | |
7dfc0fbe BS |
3490 | propagate_block (bb, new_live_at_end, bb->local_set, |
3491 | bb->cond_local_set, flags); | |
d3a923ee RH |
3492 | |
3493 | /* If live_at start didn't change, no need to go farther. */ | |
3494 | if (REG_SET_EQUAL_P (bb->global_live_at_start, new_live_at_end)) | |
3495 | continue; | |
3496 | ||
3497 | COPY_REG_SET (bb->global_live_at_start, new_live_at_end); | |
3498 | } | |
3499 | ||
3500 | /* Queue all predecessors of BB so that we may re-examine | |
3501 | their live_at_end. */ | |
c9bacfdb | 3502 | for (e = bb->pred; e; e = e->pred_next) |
d3a923ee RH |
3503 | { |
3504 | basic_block pb = e->src; | |
3505 | if (pb->aux == NULL) | |
3506 | { | |
3507 | *qtail++ = pb; | |
3508 | if (qtail == qend) | |
3509 | qtail = queue; | |
3510 | pb->aux = pb; | |
3511 | } | |
3512 | } | |
3513 | } | |
3514 | ||
3515 | FREE_REG_SET (tmp); | |
3516 | FREE_REG_SET (new_live_at_end); | |
3517 | ||
693d9e2f | 3518 | if (blocks_out) |
d3a923ee | 3519 | { |
693d9e2f RH |
3520 | EXECUTE_IF_SET_IN_SBITMAP (blocks_out, 0, i, |
3521 | { | |
3522 | basic_block bb = BASIC_BLOCK (i); | |
3523 | FREE_REG_SET (bb->local_set); | |
7dfc0fbe | 3524 | FREE_REG_SET (bb->cond_local_set); |
693d9e2f RH |
3525 | }); |
3526 | } | |
3527 | else | |
3528 | { | |
3529 | for (i = n_basic_blocks - 1; i >= 0; --i) | |
3530 | { | |
3531 | basic_block bb = BASIC_BLOCK (i); | |
3532 | FREE_REG_SET (bb->local_set); | |
7dfc0fbe | 3533 | FREE_REG_SET (bb->cond_local_set); |
693d9e2f RH |
3534 | } |
3535 | } | |
67289ea6 MM |
3536 | |
3537 | free (queue); | |
d7429b6a RK |
3538 | } |
3539 | \f | |
3540 | /* Subroutines of life analysis. */ | |
3541 | ||
3542 | /* Allocate the permanent data structures that represent the results | |
3543 | of life analysis. Not static since used also for stupid life analysis. */ | |
3544 | ||
1f8f4a0b | 3545 | static void |
359da67d | 3546 | allocate_bb_life_data () |
d7429b6a RK |
3547 | { |
3548 | register int i; | |
d7429b6a | 3549 | |
e881bb1b RH |
3550 | for (i = 0; i < n_basic_blocks; i++) |
3551 | { | |
3552 | basic_block bb = BASIC_BLOCK (i); | |
3553 | ||
1f8f4a0b MM |
3554 | bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); |
3555 | bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
e881bb1b RH |
3556 | } |
3557 | ||
3558 | ENTRY_BLOCK_PTR->global_live_at_end | |
1f8f4a0b | 3559 | = OBSTACK_ALLOC_REG_SET (&flow_obstack); |
e881bb1b | 3560 | EXIT_BLOCK_PTR->global_live_at_start |
1f8f4a0b | 3561 | = OBSTACK_ALLOC_REG_SET (&flow_obstack); |
d7429b6a | 3562 | |
1f8f4a0b | 3563 | regs_live_at_setjmp = OBSTACK_ALLOC_REG_SET (&flow_obstack); |
359da67d RH |
3564 | } |
3565 | ||
3566 | void | |
3567 | allocate_reg_life_data () | |
3568 | { | |
3569 | int i; | |
3570 | ||
a9f531a6 RH |
3571 | max_regno = max_reg_num (); |
3572 | ||
359da67d RH |
3573 | /* Recalculate the register space, in case it has grown. Old style |
3574 | vector oriented regsets would set regset_{size,bytes} here also. */ | |
3575 | allocate_reg_info (max_regno, FALSE, FALSE); | |
3576 | ||
c9bacfdb | 3577 | /* Reset all the data we'll collect in propagate_block and its |
49c3bb12 | 3578 | subroutines. */ |
359da67d | 3579 | for (i = 0; i < max_regno; i++) |
49c3bb12 RH |
3580 | { |
3581 | REG_N_SETS (i) = 0; | |
3582 | REG_N_REFS (i) = 0; | |
3583 | REG_N_DEATHS (i) = 0; | |
3584 | REG_N_CALLS_CROSSED (i) = 0; | |
3585 | REG_LIVE_LENGTH (i) = 0; | |
3586 | REG_BASIC_BLOCK (i) = REG_BLOCK_UNKNOWN; | |
3587 | } | |
d7429b6a RK |
3588 | } |
3589 | ||
62828c00 | 3590 | /* Delete dead instructions for propagate_block. */ |
d7429b6a | 3591 | |
62828c00 RH |
3592 | static void |
3593 | propagate_block_delete_insn (bb, insn) | |
3594 | basic_block bb; | |
3595 | rtx insn; | |
3596 | { | |
3597 | rtx inote = find_reg_note (insn, REG_LABEL, NULL_RTX); | |
d7429b6a | 3598 | |
62828c00 RH |
3599 | /* If the insn referred to a label, and that label was attached to |
3600 | an ADDR_VEC, it's safe to delete the ADDR_VEC. In fact, it's | |
3601 | pretty much mandatory to delete it, because the ADDR_VEC may be | |
3602 | referencing labels that no longer exist. */ | |
d7429b6a | 3603 | |
62828c00 RH |
3604 | if (inote) |
3605 | { | |
3606 | rtx label = XEXP (inote, 0); | |
3607 | rtx next; | |
3608 | ||
3609 | if (LABEL_NUSES (label) == 1 | |
3610 | && (next = next_nonnote_insn (label)) != NULL | |
3611 | && GET_CODE (next) == JUMP_INSN | |
3612 | && (GET_CODE (PATTERN (next)) == ADDR_VEC | |
3613 | || GET_CODE (PATTERN (next)) == ADDR_DIFF_VEC)) | |
3614 | { | |
3615 | rtx pat = PATTERN (next); | |
3616 | int diff_vec_p = GET_CODE (pat) == ADDR_DIFF_VEC; | |
3617 | int len = XVECLEN (pat, diff_vec_p); | |
3618 | int i; | |
d7429b6a | 3619 | |
62828c00 RH |
3620 | for (i = 0; i < len; i++) |
3621 | LABEL_NUSES (XEXP (XVECEXP (pat, diff_vec_p, i), 0))--; | |
d7429b6a | 3622 | |
62828c00 RH |
3623 | flow_delete_insn (next); |
3624 | } | |
3625 | } | |
3626 | ||
3627 | if (bb->end == insn) | |
3628 | bb->end = PREV_INSN (insn); | |
3629 | flow_delete_insn (insn); | |
3630 | } | |
3631 | ||
3632 | /* Delete dead libcalls for propagate_block. Return the insn | |
3633 | before the libcall. */ | |
3634 | ||
3635 | static rtx | |
3636 | propagate_block_delete_libcall (bb, insn, note) | |
65f6fa24 | 3637 | basic_block bb; |
62828c00 | 3638 | rtx insn, note; |
d7429b6a | 3639 | { |
62828c00 RH |
3640 | rtx first = XEXP (note, 0); |
3641 | rtx before = PREV_INSN (first); | |
d7429b6a | 3642 | |
62828c00 RH |
3643 | if (insn == bb->end) |
3644 | bb->end = before; | |
c9bacfdb | 3645 | |
62828c00 RH |
3646 | flow_delete_insn_chain (first, insn); |
3647 | return before; | |
3648 | } | |
d7429b6a | 3649 | |
292f3869 RH |
3650 | /* Update the life-status of regs for one insn. Return the previous insn. */ |
3651 | ||
3652 | rtx | |
3653 | propagate_one_insn (pbi, insn) | |
3654 | struct propagate_block_info *pbi; | |
3655 | rtx insn; | |
3656 | { | |
3657 | rtx prev = PREV_INSN (insn); | |
3658 | int flags = pbi->flags; | |
3659 | int insn_is_dead = 0; | |
3660 | int libcall_is_dead = 0; | |
3661 | rtx note; | |
3662 | int i; | |
3663 | ||
3664 | if (! INSN_P (insn)) | |
3665 | return prev; | |
3666 | ||
3667 | note = find_reg_note (insn, REG_RETVAL, NULL_RTX); | |
3668 | if (flags & PROP_SCAN_DEAD_CODE) | |
3669 | { | |
3670 | insn_is_dead = insn_dead_p (pbi, PATTERN (insn), 0, | |
3671 | REG_NOTES (insn)); | |
3672 | libcall_is_dead = (insn_is_dead && note != 0 | |
01fbc97d | 3673 | && libcall_dead_p (pbi, note, insn)); |
292f3869 RH |
3674 | } |
3675 | ||
3676 | /* We almost certainly don't want to delete prologue or epilogue | |
3677 | instructions. Warn about probable compiler losage. */ | |
3678 | if (insn_is_dead | |
3679 | && reload_completed | |
3680 | && (((HAVE_epilogue || HAVE_prologue) | |
3681 | && prologue_epilogue_contains (insn)) | |
3682 | || (HAVE_sibcall_epilogue | |
8cd8f856 GK |
3683 | && sibcall_epilogue_contains (insn))) |
3684 | && find_reg_note (insn, REG_MAYBE_DEAD, NULL_RTX) == 0) | |
292f3869 RH |
3685 | { |
3686 | if (flags & PROP_KILL_DEAD_CODE) | |
c9bacfdb | 3687 | { |
292f3869 RH |
3688 | warning ("ICE: would have deleted prologue/epilogue insn"); |
3689 | if (!inhibit_warnings) | |
3690 | debug_rtx (insn); | |
3691 | } | |
3692 | libcall_is_dead = insn_is_dead = 0; | |
3693 | } | |
3694 | ||
3695 | /* If an instruction consists of just dead store(s) on final pass, | |
3696 | delete it. */ | |
3697 | if ((flags & PROP_KILL_DEAD_CODE) && insn_is_dead) | |
3698 | { | |
5e9e738c RH |
3699 | /* Record sets. Do this even for dead instructions, since they |
3700 | would have killed the values if they hadn't been deleted. */ | |
3701 | mark_set_regs (pbi, PATTERN (insn), insn); | |
3702 | ||
3703 | /* CC0 is now known to be dead. Either this insn used it, | |
3704 | in which case it doesn't anymore, or clobbered it, | |
3705 | so the next insn can't use it. */ | |
3706 | pbi->cc0_live = 0; | |
3707 | ||
292f3869 RH |
3708 | if (libcall_is_dead) |
3709 | { | |
3710 | prev = propagate_block_delete_libcall (pbi->bb, insn, note); | |
3711 | insn = NEXT_INSN (prev); | |
3712 | } | |
3713 | else | |
3714 | propagate_block_delete_insn (pbi->bb, insn); | |
3715 | ||
292f3869 RH |
3716 | return prev; |
3717 | } | |
3718 | ||
3719 | /* See if this is an increment or decrement that can be merged into | |
3720 | a following memory address. */ | |
3721 | #ifdef AUTO_INC_DEC | |
3722 | { | |
3723 | register rtx x = single_set (insn); | |
3724 | ||
3725 | /* Does this instruction increment or decrement a register? */ | |
61f286b6 | 3726 | if ((flags & PROP_AUTOINC) |
292f3869 RH |
3727 | && x != 0 |
3728 | && GET_CODE (SET_DEST (x)) == REG | |
3729 | && (GET_CODE (SET_SRC (x)) == PLUS | |
3730 | || GET_CODE (SET_SRC (x)) == MINUS) | |
3731 | && XEXP (SET_SRC (x), 0) == SET_DEST (x) | |
3732 | && GET_CODE (XEXP (SET_SRC (x), 1)) == CONST_INT | |
3733 | /* Ok, look for a following memory ref we can combine with. | |
3734 | If one is found, change the memory ref to a PRE_INC | |
3735 | or PRE_DEC, cancel this insn, and return 1. | |
3736 | Return 0 if nothing has been done. */ | |
3737 | && try_pre_increment_1 (pbi, insn)) | |
3738 | return prev; | |
3739 | } | |
3740 | #endif /* AUTO_INC_DEC */ | |
3741 | ||
9785c68d | 3742 | CLEAR_REG_SET (pbi->new_set); |
292f3869 RH |
3743 | |
3744 | /* If this is not the final pass, and this insn is copying the value of | |
3745 | a library call and it's dead, don't scan the insns that perform the | |
3746 | library call, so that the call's arguments are not marked live. */ | |
3747 | if (libcall_is_dead) | |
3748 | { | |
3749 | /* Record the death of the dest reg. */ | |
3750 | mark_set_regs (pbi, PATTERN (insn), insn); | |
3751 | ||
3752 | insn = XEXP (note, 0); | |
3753 | return PREV_INSN (insn); | |
3754 | } | |
3755 | else if (GET_CODE (PATTERN (insn)) == SET | |
3756 | && SET_DEST (PATTERN (insn)) == stack_pointer_rtx | |
3757 | && GET_CODE (SET_SRC (PATTERN (insn))) == PLUS | |
3758 | && XEXP (SET_SRC (PATTERN (insn)), 0) == stack_pointer_rtx | |
3759 | && GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == CONST_INT) | |
3760 | /* We have an insn to pop a constant amount off the stack. | |
3761 | (Such insns use PLUS regardless of the direction of the stack, | |
3762 | and any insn to adjust the stack by a constant is always a pop.) | |
3763 | These insns, if not dead stores, have no effect on life. */ | |
3764 | ; | |
3765 | else | |
3766 | { | |
3767 | /* Any regs live at the time of a call instruction must not go | |
3768 | in a register clobbered by calls. Find all regs now live and | |
3769 | record this for them. */ | |
3770 | ||
3771 | if (GET_CODE (insn) == CALL_INSN && (flags & PROP_REG_INFO)) | |
3772 | EXECUTE_IF_SET_IN_REG_SET (pbi->reg_live, 0, i, | |
3773 | { REG_N_CALLS_CROSSED (i)++; }); | |
3774 | ||
3775 | /* Record sets. Do this even for dead instructions, since they | |
3776 | would have killed the values if they hadn't been deleted. */ | |
3777 | mark_set_regs (pbi, PATTERN (insn), insn); | |
3778 | ||
3779 | if (GET_CODE (insn) == CALL_INSN) | |
3780 | { | |
3781 | register int i; | |
3782 | rtx note, cond; | |
3783 | ||
3784 | cond = NULL_RTX; | |
3785 | if (GET_CODE (PATTERN (insn)) == COND_EXEC) | |
3786 | cond = COND_EXEC_TEST (PATTERN (insn)); | |
3787 | ||
3788 | /* Non-constant calls clobber memory. */ | |
3789 | if (! CONST_CALL_P (insn)) | |
3790 | free_EXPR_LIST_list (&pbi->mem_set_list); | |
3791 | ||
3792 | /* There may be extra registers to be clobbered. */ | |
3793 | for (note = CALL_INSN_FUNCTION_USAGE (insn); | |
3794 | note; | |
3795 | note = XEXP (note, 1)) | |
3796 | if (GET_CODE (XEXP (note, 0)) == CLOBBER) | |
b4593d17 RH |
3797 | mark_set_1 (pbi, CLOBBER, XEXP (XEXP (note, 0), 0), |
3798 | cond, insn, pbi->flags); | |
292f3869 RH |
3799 | |
3800 | /* Calls change all call-used and global registers. */ | |
3801 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
3802 | if (call_used_regs[i] && ! global_regs[i] | |
3803 | && ! fixed_regs[i]) | |
3804 | { | |
b4593d17 RH |
3805 | /* We do not want REG_UNUSED notes for these registers. */ |
3806 | mark_set_1 (pbi, CLOBBER, gen_rtx_REG (reg_raw_mode[i], i), | |
8d6fe133 RH |
3807 | cond, insn, |
3808 | pbi->flags & ~(PROP_DEATH_NOTES | PROP_REG_INFO)); | |
292f3869 RH |
3809 | } |
3810 | } | |
3811 | ||
3812 | /* If an insn doesn't use CC0, it becomes dead since we assume | |
3813 | that every insn clobbers it. So show it dead here; | |
3814 | mark_used_regs will set it live if it is referenced. */ | |
3815 | pbi->cc0_live = 0; | |
3816 | ||
3817 | /* Record uses. */ | |
3818 | if (! insn_is_dead) | |
3819 | mark_used_regs (pbi, PATTERN (insn), NULL_RTX, insn); | |
3820 | ||
3821 | /* Sometimes we may have inserted something before INSN (such as a move) | |
3822 | when we make an auto-inc. So ensure we will scan those insns. */ | |
3823 | #ifdef AUTO_INC_DEC | |
3824 | prev = PREV_INSN (insn); | |
3825 | #endif | |
3826 | ||
3827 | if (! insn_is_dead && GET_CODE (insn) == CALL_INSN) | |
3828 | { | |
3829 | register int i; | |
3830 | rtx note, cond; | |
3831 | ||
3832 | cond = NULL_RTX; | |
3833 | if (GET_CODE (PATTERN (insn)) == COND_EXEC) | |
3834 | cond = COND_EXEC_TEST (PATTERN (insn)); | |
3835 | ||
3836 | /* Calls use their arguments. */ | |
3837 | for (note = CALL_INSN_FUNCTION_USAGE (insn); | |
3838 | note; | |
3839 | note = XEXP (note, 1)) | |
3840 | if (GET_CODE (XEXP (note, 0)) == USE) | |
3841 | mark_used_regs (pbi, XEXP (XEXP (note, 0), 0), | |
3842 | cond, insn); | |
3843 | ||
3844 | /* The stack ptr is used (honorarily) by a CALL insn. */ | |
3845 | SET_REGNO_REG_SET (pbi->reg_live, STACK_POINTER_REGNUM); | |
3846 | ||
3847 | /* Calls may also reference any of the global registers, | |
3848 | so they are made live. */ | |
3849 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
3850 | if (global_regs[i]) | |
3851 | mark_used_reg (pbi, gen_rtx_REG (reg_raw_mode[i], i), | |
3852 | cond, insn); | |
3853 | } | |
3854 | } | |
3855 | ||
292f3869 RH |
3856 | /* On final pass, update counts of how many insns in which each reg |
3857 | is live. */ | |
3858 | if (flags & PROP_REG_INFO) | |
3859 | EXECUTE_IF_SET_IN_REG_SET (pbi->reg_live, 0, i, | |
3860 | { REG_LIVE_LENGTH (i)++; }); | |
3861 | ||
3862 | return prev; | |
3863 | } | |
3864 | ||
3865 | /* Initialize a propagate_block_info struct for public consumption. | |
3866 | Note that the structure itself is opaque to this file, but that | |
3867 | the user can use the regsets provided here. */ | |
3868 | ||
3869 | struct propagate_block_info * | |
7dfc0fbe | 3870 | init_propagate_block_info (bb, live, local_set, cond_local_set, flags) |
292f3869 | 3871 | basic_block bb; |
7dfc0fbe | 3872 | regset live, local_set, cond_local_set; |
292f3869 RH |
3873 | int flags; |
3874 | { | |
c9bacfdb | 3875 | struct propagate_block_info *pbi = xmalloc (sizeof (*pbi)); |
292f3869 RH |
3876 | |
3877 | pbi->bb = bb; | |
3878 | pbi->reg_live = live; | |
3879 | pbi->mem_set_list = NULL_RTX; | |
3880 | pbi->local_set = local_set; | |
7dfc0fbe | 3881 | pbi->cond_local_set = cond_local_set; |
292f3869 RH |
3882 | pbi->cc0_live = 0; |
3883 | pbi->flags = flags; | |
3884 | ||
3885 | if (flags & (PROP_LOG_LINKS | PROP_AUTOINC)) | |
3886 | pbi->reg_next_use = (rtx *) xcalloc (max_reg_num (), sizeof (rtx)); | |
3887 | else | |
3888 | pbi->reg_next_use = NULL; | |
3889 | ||
9785c68d | 3890 | pbi->new_set = BITMAP_XMALLOC (); |
292f3869 | 3891 | |
11ae508b RH |
3892 | #ifdef HAVE_conditional_execution |
3893 | pbi->reg_cond_dead = splay_tree_new (splay_tree_compare_ints, NULL, | |
3894 | free_reg_cond_life_info); | |
3895 | pbi->reg_cond_reg = BITMAP_XMALLOC (); | |
3896 | ||
3897 | /* If this block ends in a conditional branch, for each register live | |
3898 | from one side of the branch and not the other, record the register | |
3899 | as conditionally dead. */ | |
eb7e5da2 RH |
3900 | if ((flags & (PROP_DEATH_NOTES | PROP_SCAN_DEAD_CODE)) |
3901 | && GET_CODE (bb->end) == JUMP_INSN | |
7f1c097d | 3902 | && any_condjump_p (bb->end)) |
11ae508b RH |
3903 | { |
3904 | regset_head diff_head; | |
3905 | regset diff = INITIALIZE_REG_SET (diff_head); | |
3906 | basic_block bb_true, bb_false; | |
3a8c5c77 | 3907 | rtx cond_true, cond_false, set_src; |
11ae508b RH |
3908 | int i; |
3909 | ||
3910 | /* Identify the successor blocks. */ | |
11ae508b | 3911 | bb_true = bb->succ->dest; |
4fb9b830 | 3912 | if (bb->succ->succ_next != NULL) |
11ae508b | 3913 | { |
c9bacfdb | 3914 | bb_false = bb->succ->succ_next->dest; |
4fb9b830 RH |
3915 | |
3916 | if (bb->succ->flags & EDGE_FALLTHRU) | |
3917 | { | |
3918 | basic_block t = bb_false; | |
3919 | bb_false = bb_true; | |
3920 | bb_true = t; | |
3921 | } | |
3922 | else if (! (bb->succ->succ_next->flags & EDGE_FALLTHRU)) | |
3923 | abort (); | |
3924 | } | |
3925 | else | |
3926 | { | |
3927 | /* This can happen with a conditional jump to the next insn. */ | |
3928 | if (JUMP_LABEL (bb->end) != bb_true->head) | |
3929 | abort (); | |
3930 | ||
3931 | /* Simplest way to do nothing. */ | |
11ae508b | 3932 | bb_false = bb_true; |
11ae508b | 3933 | } |
c9bacfdb | 3934 | |
11ae508b | 3935 | /* Extract the condition from the branch. */ |
3a8c5c77 RH |
3936 | set_src = SET_SRC (pc_set (bb->end)); |
3937 | cond_true = XEXP (set_src, 0); | |
11ae508b RH |
3938 | cond_false = gen_rtx_fmt_ee (reverse_condition (GET_CODE (cond_true)), |
3939 | GET_MODE (cond_true), XEXP (cond_true, 0), | |
3940 | XEXP (cond_true, 1)); | |
3a8c5c77 | 3941 | if (GET_CODE (XEXP (set_src, 1)) == PC) |
11ae508b RH |
3942 | { |
3943 | rtx t = cond_false; | |
3944 | cond_false = cond_true; | |
3945 | cond_true = t; | |
3946 | } | |
3947 | ||
3948 | /* Compute which register lead different lives in the successors. */ | |
3949 | if (bitmap_operation (diff, bb_true->global_live_at_start, | |
3950 | bb_false->global_live_at_start, BITMAP_XOR)) | |
3951 | { | |
056b6841 RE |
3952 | rtx reg = XEXP (cond_true, 0); |
3953 | ||
3954 | if (GET_CODE (reg) == SUBREG) | |
3955 | reg = SUBREG_REG (reg); | |
3956 | ||
3957 | if (GET_CODE (reg) != REG) | |
11ae508b | 3958 | abort (); |
056b6841 RE |
3959 | |
3960 | SET_REGNO_REG_SET (pbi->reg_cond_reg, REGNO (reg)); | |
11ae508b RH |
3961 | |
3962 | /* For each such register, mark it conditionally dead. */ | |
3963 | EXECUTE_IF_SET_IN_REG_SET | |
3964 | (diff, 0, i, | |
3965 | { | |
3966 | struct reg_cond_life_info *rcli; | |
3967 | rtx cond; | |
3968 | ||
3969 | rcli = (struct reg_cond_life_info *) xmalloc (sizeof (*rcli)); | |
3970 | ||
3971 | if (REGNO_REG_SET_P (bb_true->global_live_at_start, i)) | |
3972 | cond = cond_false; | |
3973 | else | |
3974 | cond = cond_true; | |
3975 | rcli->condition = alloc_EXPR_LIST (0, cond, NULL_RTX); | |
3976 | ||
ad3958e7 | 3977 | splay_tree_insert (pbi->reg_cond_dead, i, |
11ae508b RH |
3978 | (splay_tree_value) rcli); |
3979 | }); | |
3980 | } | |
3981 | ||
3982 | FREE_REG_SET (diff); | |
3983 | } | |
3984 | #endif | |
3985 | ||
eb7e5da2 RH |
3986 | /* If this block has no successors, any stores to the frame that aren't |
3987 | used later in the block are dead. So make a pass over the block | |
3988 | recording any such that are made and show them dead at the end. We do | |
3989 | a very conservative and simple job here. */ | |
b2262f4a | 3990 | if (optimize |
6324d2bb RK |
3991 | && ! (TREE_CODE (TREE_TYPE (current_function_decl)) == FUNCTION_TYPE |
3992 | && (TYPE_RETURNS_STACK_DEPRESSED | |
3993 | (TREE_TYPE (current_function_decl)))) | |
b2262f4a | 3994 | && (flags & PROP_SCAN_DEAD_CODE) |
eb7e5da2 | 3995 | && (bb->succ == NULL |
c9bacfdb | 3996 | || (bb->succ->succ_next == NULL |
eb7e5da2 RH |
3997 | && bb->succ->dest == EXIT_BLOCK_PTR))) |
3998 | { | |
3999 | rtx insn; | |
4000 | for (insn = bb->end; insn != bb->head; insn = PREV_INSN (insn)) | |
4001 | if (GET_CODE (insn) == INSN | |
4002 | && GET_CODE (PATTERN (insn)) == SET | |
4003 | && GET_CODE (SET_DEST (PATTERN (insn))) == MEM) | |
4004 | { | |
4005 | rtx mem = SET_DEST (PATTERN (insn)); | |
c9bacfdb | 4006 | |
eb7e5da2 RH |
4007 | if (XEXP (mem, 0) == frame_pointer_rtx |
4008 | || (GET_CODE (XEXP (mem, 0)) == PLUS | |
4009 | && XEXP (XEXP (mem, 0), 0) == frame_pointer_rtx | |
4010 | && GET_CODE (XEXP (XEXP (mem, 0), 1)) == CONST_INT)) | |
c32e1e6f RH |
4011 | { |
4012 | #ifdef AUTO_INC_DEC | |
4013 | /* Store a copy of mem, otherwise the address may be scrogged | |
4014 | by find_auto_inc. This matters because insn_dead_p uses | |
4015 | an rtx_equal_p check to determine if two addresses are | |
4016 | the same. This works before find_auto_inc, but fails | |
4017 | after find_auto_inc, causing discrepencies between the | |
4018 | set of live registers calculated during the | |
4019 | calculate_global_regs_live phase and what actually exists | |
4020 | after flow completes, leading to aborts. */ | |
4021 | if (flags & PROP_AUTOINC) | |
4022 | mem = shallow_copy_rtx (mem); | |
4023 | #endif | |
4024 | pbi->mem_set_list = alloc_EXPR_LIST (0, mem, pbi->mem_set_list); | |
4025 | } | |
eb7e5da2 RH |
4026 | } |
4027 | } | |
4028 | ||
292f3869 RH |
4029 | return pbi; |
4030 | } | |
4031 | ||
4032 | /* Release a propagate_block_info struct. */ | |
4033 | ||
4034 | void | |
4035 | free_propagate_block_info (pbi) | |
4036 | struct propagate_block_info *pbi; | |
4037 | { | |
4038 | free_EXPR_LIST_list (&pbi->mem_set_list); | |
4039 | ||
9785c68d | 4040 | BITMAP_XFREE (pbi->new_set); |
292f3869 | 4041 | |
11ae508b RH |
4042 | #ifdef HAVE_conditional_execution |
4043 | splay_tree_delete (pbi->reg_cond_dead); | |
4044 | BITMAP_XFREE (pbi->reg_cond_reg); | |
4045 | #endif | |
4046 | ||
292f3869 RH |
4047 | if (pbi->reg_next_use) |
4048 | free (pbi->reg_next_use); | |
4049 | ||
4050 | free (pbi); | |
4051 | } | |
4052 | ||
62828c00 RH |
4053 | /* Compute the registers live at the beginning of a basic block BB from |
4054 | those live at the end. | |
d7429b6a | 4055 | |
62828c00 RH |
4056 | When called, REG_LIVE contains those live at the end. On return, it |
4057 | contains those live at the beginning. | |
4058 | ||
7dfc0fbe BS |
4059 | LOCAL_SET, if non-null, will be set with all registers killed |
4060 | unconditionally by this basic block. | |
4061 | Likewise, COND_LOCAL_SET, if non-null, will be set with all registers | |
4062 | killed conditionally by this basic block. If there is any unconditional | |
4063 | set of a register, then the corresponding bit will be set in LOCAL_SET | |
4064 | and cleared in COND_LOCAL_SET. | |
4065 | It is valid for LOCAL_SET and COND_LOCAL_SET to be the same set. In this | |
4066 | case, the resulting set will be equal to the union of the two sets that | |
4067 | would otherwise be computed. */ | |
62828c00 | 4068 | |
292f3869 | 4069 | void |
7dfc0fbe | 4070 | propagate_block (bb, live, local_set, cond_local_set, flags) |
62828c00 RH |
4071 | basic_block bb; |
4072 | regset live; | |
4073 | regset local_set; | |
7dfc0fbe | 4074 | regset cond_local_set; |
62828c00 RH |
4075 | int flags; |
4076 | { | |
292f3869 | 4077 | struct propagate_block_info *pbi; |
62828c00 | 4078 | rtx insn, prev; |
c9bacfdb | 4079 | |
7dfc0fbe | 4080 | pbi = init_propagate_block_info (bb, live, local_set, cond_local_set, flags); |
d7429b6a | 4081 | |
d3a923ee | 4082 | if (flags & PROP_REG_INFO) |
d7429b6a | 4083 | { |
916b1701 | 4084 | register int i; |
d7429b6a | 4085 | |
d7429b6a | 4086 | /* Process the regs live at the end of the block. |
c9bacfdb | 4087 | Mark them as not local to any one basic block. */ |
62828c00 | 4088 | EXECUTE_IF_SET_IN_REG_SET (live, 0, i, |
292f3869 | 4089 | { REG_BASIC_BLOCK (i) = REG_BLOCK_GLOBAL; }); |
d7429b6a RK |
4090 | } |
4091 | ||
4092 | /* Scan the block an insn at a time from end to beginning. */ | |
4093 | ||
c9bacfdb | 4094 | for (insn = bb->end;; insn = prev) |
d7429b6a | 4095 | { |
292f3869 RH |
4096 | /* If this is a call to `setjmp' et al, warn if any |
4097 | non-volatile datum is live. */ | |
4098 | if ((flags & PROP_REG_INFO) | |
4099 | && GET_CODE (insn) == NOTE | |
4100 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_SETJMP) | |
4101 | IOR_REG_SET (regs_live_at_setjmp, pbi->reg_live); | |
11f246f6 | 4102 | |
292f3869 | 4103 | prev = propagate_one_insn (pbi, insn); |
d7429b6a | 4104 | |
65f6fa24 | 4105 | if (insn == bb->head) |
d7429b6a RK |
4106 | break; |
4107 | } | |
4108 | ||
292f3869 | 4109 | free_propagate_block_info (pbi); |
d7429b6a RK |
4110 | } |
4111 | \f | |
4112 | /* Return 1 if X (the body of an insn, or part of it) is just dead stores | |
4113 | (SET expressions whose destinations are registers dead after the insn). | |
4114 | NEEDED is the regset that says which regs are alive after the insn. | |
4115 | ||
e398aa80 R |
4116 | Unless CALL_OK is non-zero, an insn is needed if it contains a CALL. |
4117 | ||
4118 | If X is the entire body of an insn, NOTES contains the reg notes | |
4119 | pertaining to the insn. */ | |
d7429b6a RK |
4120 | |
4121 | static int | |
62828c00 RH |
4122 | insn_dead_p (pbi, x, call_ok, notes) |
4123 | struct propagate_block_info *pbi; | |
d7429b6a | 4124 | rtx x; |
d7429b6a | 4125 | int call_ok; |
e398aa80 | 4126 | rtx notes ATTRIBUTE_UNUSED; |
d7429b6a | 4127 | { |
e5e809f4 JL |
4128 | enum rtx_code code = GET_CODE (x); |
4129 | ||
e398aa80 R |
4130 | #ifdef AUTO_INC_DEC |
4131 | /* If flow is invoked after reload, we must take existing AUTO_INC | |
4132 | expresions into account. */ | |
4133 | if (reload_completed) | |
4134 | { | |
c9bacfdb | 4135 | for (; notes; notes = XEXP (notes, 1)) |
e398aa80 R |
4136 | { |
4137 | if (REG_NOTE_KIND (notes) == REG_INC) | |
4138 | { | |
4139 | int regno = REGNO (XEXP (notes, 0)); | |
4140 | ||
4141 | /* Don't delete insns to set global regs. */ | |
4142 | if ((regno < FIRST_PSEUDO_REGISTER && global_regs[regno]) | |
62828c00 | 4143 | || REGNO_REG_SET_P (pbi->reg_live, regno)) |
e398aa80 R |
4144 | return 0; |
4145 | } | |
4146 | } | |
4147 | } | |
4148 | #endif | |
4149 | ||
d7429b6a RK |
4150 | /* If setting something that's a reg or part of one, |
4151 | see if that register's altered value will be live. */ | |
4152 | ||
4153 | if (code == SET) | |
4154 | { | |
e5e809f4 JL |
4155 | rtx r = SET_DEST (x); |
4156 | ||
d7429b6a RK |
4157 | #ifdef HAVE_cc0 |
4158 | if (GET_CODE (r) == CC0) | |
62828c00 | 4159 | return ! pbi->cc0_live; |
d7429b6a | 4160 | #endif |
c9bacfdb | 4161 | |
3ea8083f JL |
4162 | /* A SET that is a subroutine call cannot be dead. */ |
4163 | if (GET_CODE (SET_SRC (x)) == CALL) | |
4164 | { | |
4165 | if (! call_ok) | |
4166 | return 0; | |
4167 | } | |
4168 | ||
4169 | /* Don't eliminate loads from volatile memory or volatile asms. */ | |
4170 | else if (volatile_refs_p (SET_SRC (x))) | |
4171 | return 0; | |
4172 | ||
4173 | if (GET_CODE (r) == MEM) | |
db3a887b CB |
4174 | { |
4175 | rtx temp; | |
3ea8083f JL |
4176 | |
4177 | if (MEM_VOLATILE_P (r)) | |
4178 | return 0; | |
4179 | ||
db3a887b CB |
4180 | /* Walk the set of memory locations we are currently tracking |
4181 | and see if one is an identical match to this memory location. | |
4182 | If so, this memory write is dead (remember, we're walking | |
51891abe | 4183 | backwards from the end of the block to the start). */ |
62828c00 | 4184 | temp = pbi->mem_set_list; |
db3a887b CB |
4185 | while (temp) |
4186 | { | |
4f4b88d0 HB |
4187 | rtx mem = XEXP (temp, 0); |
4188 | ||
4189 | if (rtx_equal_p (mem, r)) | |
4190 | return 1; | |
4191 | #ifdef AUTO_INC_DEC | |
4192 | /* Check if memory reference matches an auto increment. Only | |
4193 | post increment/decrement or modify are valid. */ | |
4194 | if (GET_MODE (mem) == GET_MODE (r) | |
4195 | && (GET_CODE (XEXP (mem, 0)) == POST_DEC | |
4196 | || GET_CODE (XEXP (mem, 0)) == POST_INC | |
4197 | || GET_CODE (XEXP (mem, 0)) == POST_MODIFY) | |
4198 | && GET_MODE (XEXP (mem, 0)) == GET_MODE (r) | |
4199 | && rtx_equal_p (XEXP (XEXP (mem, 0), 0), XEXP (r, 0))) | |
db3a887b | 4200 | return 1; |
4f4b88d0 | 4201 | #endif |
db3a887b CB |
4202 | temp = XEXP (temp, 1); |
4203 | } | |
4204 | } | |
3ea8083f JL |
4205 | else |
4206 | { | |
4207 | while (GET_CODE (r) == SUBREG | |
4208 | || GET_CODE (r) == STRICT_LOW_PART | |
4209 | || GET_CODE (r) == ZERO_EXTRACT) | |
4210 | r = XEXP (r, 0); | |
d7429b6a | 4211 | |
3ea8083f JL |
4212 | if (GET_CODE (r) == REG) |
4213 | { | |
4214 | int regno = REGNO (r); | |
d7429b6a | 4215 | |
3ea8083f | 4216 | /* Obvious. */ |
62828c00 | 4217 | if (REGNO_REG_SET_P (pbi->reg_live, regno)) |
3ea8083f JL |
4218 | return 0; |
4219 | ||
4220 | /* If this is a hard register, verify that subsequent | |
4221 | words are not needed. */ | |
4222 | if (regno < FIRST_PSEUDO_REGISTER) | |
4223 | { | |
4224 | int n = HARD_REGNO_NREGS (regno, GET_MODE (r)); | |
4225 | ||
4226 | while (--n > 0) | |
62828c00 | 4227 | if (REGNO_REG_SET_P (pbi->reg_live, regno+n)) |
3ea8083f JL |
4228 | return 0; |
4229 | } | |
4230 | ||
4231 | /* Don't delete insns to set global regs. */ | |
4232 | if (regno < FIRST_PSEUDO_REGISTER && global_regs[regno]) | |
4233 | return 0; | |
4234 | ||
4235 | /* Make sure insns to set the stack pointer aren't deleted. */ | |
4236 | if (regno == STACK_POINTER_REGNUM) | |
4237 | return 0; | |
d7429b6a | 4238 | |
39c39be9 RH |
4239 | /* ??? These bits might be redundant with the force live bits |
4240 | in calculate_global_regs_live. We would delete from | |
4241 | sequential sets; whether this actually affects real code | |
4242 | for anything but the stack pointer I don't know. */ | |
3ea8083f JL |
4243 | /* Make sure insns to set the frame pointer aren't deleted. */ |
4244 | if (regno == FRAME_POINTER_REGNUM | |
e4b8a413 | 4245 | && (! reload_completed || frame_pointer_needed)) |
3ea8083f | 4246 | return 0; |
73a187c1 | 4247 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
3ea8083f | 4248 | if (regno == HARD_FRAME_POINTER_REGNUM |
e4b8a413 | 4249 | && (! reload_completed || frame_pointer_needed)) |
3ea8083f | 4250 | return 0; |
73a187c1 | 4251 | #endif |
3ea8083f | 4252 | |
d7e4fe8b RS |
4253 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
4254 | /* Make sure insns to set arg pointer are never deleted | |
3ea8083f JL |
4255 | (if the arg pointer isn't fixed, there will be a USE |
4256 | for it, so we can treat it normally). */ | |
4257 | if (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) | |
4258 | return 0; | |
d7e4fe8b | 4259 | #endif |
d7429b6a | 4260 | |
3ea8083f JL |
4261 | /* Otherwise, the set is dead. */ |
4262 | return 1; | |
d7429b6a | 4263 | } |
d7429b6a RK |
4264 | } |
4265 | } | |
e5e809f4 | 4266 | |
3ea8083f JL |
4267 | /* If performing several activities, insn is dead if each activity |
4268 | is individually dead. Also, CLOBBERs and USEs can be ignored; a | |
4269 | CLOBBER or USE that's inside a PARALLEL doesn't make the insn | |
4270 | worth keeping. */ | |
d7429b6a RK |
4271 | else if (code == PARALLEL) |
4272 | { | |
e5e809f4 JL |
4273 | int i = XVECLEN (x, 0); |
4274 | ||
d7429b6a | 4275 | for (i--; i >= 0; i--) |
e5e809f4 JL |
4276 | if (GET_CODE (XVECEXP (x, 0, i)) != CLOBBER |
4277 | && GET_CODE (XVECEXP (x, 0, i)) != USE | |
62828c00 | 4278 | && ! insn_dead_p (pbi, XVECEXP (x, 0, i), call_ok, NULL_RTX)) |
e5e809f4 JL |
4279 | return 0; |
4280 | ||
d7429b6a RK |
4281 | return 1; |
4282 | } | |
e5e809f4 JL |
4283 | |
4284 | /* A CLOBBER of a pseudo-register that is dead serves no purpose. That | |
4285 | is not necessarily true for hard registers. */ | |
4286 | else if (code == CLOBBER && GET_CODE (XEXP (x, 0)) == REG | |
4287 | && REGNO (XEXP (x, 0)) >= FIRST_PSEUDO_REGISTER | |
62828c00 | 4288 | && ! REGNO_REG_SET_P (pbi->reg_live, REGNO (XEXP (x, 0)))) |
e5e809f4 JL |
4289 | return 1; |
4290 | ||
4291 | /* We do not check other CLOBBER or USE here. An insn consisting of just | |
4292 | a CLOBBER or just a USE should not be deleted. */ | |
d7429b6a RK |
4293 | return 0; |
4294 | } | |
4295 | ||
01fbc97d | 4296 | /* If INSN is the last insn in a libcall, and assuming INSN is dead, |
d7429b6a | 4297 | return 1 if the entire library call is dead. |
01fbc97d SC |
4298 | This is true if INSN copies a register (hard or pseudo) |
4299 | and if the hard return reg of the call insn is dead. | |
4300 | (The caller should have tested the destination of the SET inside | |
4301 | INSN already for death.) | |
d7429b6a RK |
4302 | |
4303 | If this insn doesn't just copy a register, then we don't | |
4304 | have an ordinary libcall. In that case, cse could not have | |
4305 | managed to substitute the source for the dest later on, | |
4306 | so we can assume the libcall is dead. | |
4307 | ||
01fbc97d SC |
4308 | PBI is the block info giving pseudoregs live before this insn. |
4309 | NOTE is the REG_RETVAL note of the insn. */ | |
d7429b6a RK |
4310 | |
4311 | static int | |
01fbc97d | 4312 | libcall_dead_p (pbi, note, insn) |
62828c00 | 4313 | struct propagate_block_info *pbi; |
d7429b6a RK |
4314 | rtx note; |
4315 | rtx insn; | |
4316 | { | |
01fbc97d | 4317 | rtx x = single_set (insn); |
d7429b6a | 4318 | |
01fbc97d | 4319 | if (x) |
d7429b6a RK |
4320 | { |
4321 | register rtx r = SET_SRC (x); | |
4322 | if (GET_CODE (r) == REG) | |
4323 | { | |
4324 | rtx call = XEXP (note, 0); | |
e398aa80 | 4325 | rtx call_pat; |
d7429b6a RK |
4326 | register int i; |
4327 | ||
4328 | /* Find the call insn. */ | |
4329 | while (call != insn && GET_CODE (call) != CALL_INSN) | |
4330 | call = NEXT_INSN (call); | |
4331 | ||
4332 | /* If there is none, do nothing special, | |
4333 | since ordinary death handling can understand these insns. */ | |
4334 | if (call == insn) | |
4335 | return 0; | |
4336 | ||
4337 | /* See if the hard reg holding the value is dead. | |
4338 | If this is a PARALLEL, find the call within it. */ | |
e398aa80 R |
4339 | call_pat = PATTERN (call); |
4340 | if (GET_CODE (call_pat) == PARALLEL) | |
d7429b6a | 4341 | { |
e398aa80 R |
4342 | for (i = XVECLEN (call_pat, 0) - 1; i >= 0; i--) |
4343 | if (GET_CODE (XVECEXP (call_pat, 0, i)) == SET | |
4344 | && GET_CODE (SET_SRC (XVECEXP (call_pat, 0, i))) == CALL) | |
d7429b6a RK |
4345 | break; |
4346 | ||
761a5bcd JW |
4347 | /* This may be a library call that is returning a value |
4348 | via invisible pointer. Do nothing special, since | |
4349 | ordinary death handling can understand these insns. */ | |
d7429b6a | 4350 | if (i < 0) |
761a5bcd | 4351 | return 0; |
d7429b6a | 4352 | |
e398aa80 | 4353 | call_pat = XVECEXP (call_pat, 0, i); |
d7429b6a RK |
4354 | } |
4355 | ||
62828c00 | 4356 | return insn_dead_p (pbi, call_pat, 1, REG_NOTES (call)); |
d7429b6a RK |
4357 | } |
4358 | } | |
4359 | return 1; | |
4360 | } | |
4361 | ||
bd80fbde RH |
4362 | /* Return 1 if register REGNO was used before it was set, i.e. if it is |
4363 | live at function entry. Don't count global register variables, variables | |
4364 | in registers that can be used for function arg passing, or variables in | |
4365 | fixed hard registers. */ | |
d7429b6a RK |
4366 | |
4367 | int | |
4368 | regno_uninitialized (regno) | |
4369 | int regno; | |
4370 | { | |
b0b7b46a | 4371 | if (n_basic_blocks == 0 |
6a45254e | 4372 | || (regno < FIRST_PSEUDO_REGISTER |
bd80fbde RH |
4373 | && (global_regs[regno] |
4374 | || fixed_regs[regno] | |
4375 | || FUNCTION_ARG_REGNO_P (regno)))) | |
d7429b6a RK |
4376 | return 0; |
4377 | ||
e881bb1b | 4378 | return REGNO_REG_SET_P (BASIC_BLOCK (0)->global_live_at_start, regno); |
d7429b6a RK |
4379 | } |
4380 | ||
4381 | /* 1 if register REGNO was alive at a place where `setjmp' was called | |
4382 | and was set more than once or is an argument. | |
4383 | Such regs may be clobbered by `longjmp'. */ | |
4384 | ||
4385 | int | |
4386 | regno_clobbered_at_setjmp (regno) | |
4387 | int regno; | |
4388 | { | |
4389 | if (n_basic_blocks == 0) | |
4390 | return 0; | |
4391 | ||
b1f21e0a | 4392 | return ((REG_N_SETS (regno) > 1 |
e881bb1b | 4393 | || REGNO_REG_SET_P (BASIC_BLOCK (0)->global_live_at_start, regno)) |
916b1701 | 4394 | && REGNO_REG_SET_P (regs_live_at_setjmp, regno)); |
d7429b6a RK |
4395 | } |
4396 | \f | |
15e088b2 JL |
4397 | /* INSN references memory, possibly using autoincrement addressing modes. |
4398 | Find any entries on the mem_set_list that need to be invalidated due | |
4399 | to an address change. */ | |
a4c44acf | 4400 | |
15e088b2 | 4401 | static void |
62828c00 RH |
4402 | invalidate_mems_from_autoinc (pbi, insn) |
4403 | struct propagate_block_info *pbi; | |
15e088b2 JL |
4404 | rtx insn; |
4405 | { | |
4406 | rtx note = REG_NOTES (insn); | |
4407 | for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) | |
4408 | { | |
4409 | if (REG_NOTE_KIND (note) == REG_INC) | |
c9bacfdb KH |
4410 | { |
4411 | rtx temp = pbi->mem_set_list; | |
4412 | rtx prev = NULL_RTX; | |
ff666313 | 4413 | rtx next; |
15e088b2 | 4414 | |
c9bacfdb | 4415 | while (temp) |
15e088b2 | 4416 | { |
ff666313 | 4417 | next = XEXP (temp, 1); |
15e088b2 | 4418 | if (reg_overlap_mentioned_p (XEXP (note, 0), XEXP (temp, 0))) |
c9bacfdb KH |
4419 | { |
4420 | /* Splice temp out of list. */ | |
4421 | if (prev) | |
4422 | XEXP (prev, 1) = next; | |
4423 | else | |
4424 | pbi->mem_set_list = next; | |
ff666313 | 4425 | free_EXPR_LIST_node (temp); |
c9bacfdb | 4426 | } |
15e088b2 | 4427 | else |
c9bacfdb KH |
4428 | prev = temp; |
4429 | temp = next; | |
15e088b2 JL |
4430 | } |
4431 | } | |
4432 | } | |
4433 | } | |
4434 | ||
1288c070 RH |
4435 | /* EXP is either a MEM or a REG. Remove any dependant entries |
4436 | from pbi->mem_set_list. */ | |
4437 | ||
4438 | static void | |
4439 | invalidate_mems_from_set (pbi, exp) | |
4440 | struct propagate_block_info *pbi; | |
4441 | rtx exp; | |
4442 | { | |
4443 | rtx temp = pbi->mem_set_list; | |
4444 | rtx prev = NULL_RTX; | |
4445 | rtx next; | |
4446 | ||
4447 | while (temp) | |
4448 | { | |
4449 | next = XEXP (temp, 1); | |
4450 | if ((GET_CODE (exp) == MEM | |
4451 | && output_dependence (XEXP (temp, 0), exp)) | |
4452 | || (GET_CODE (exp) == REG | |
4453 | && reg_overlap_mentioned_p (exp, XEXP (temp, 0)))) | |
4454 | { | |
4455 | /* Splice this entry out of the list. */ | |
4456 | if (prev) | |
4457 | XEXP (prev, 1) = next; | |
4458 | else | |
4459 | pbi->mem_set_list = next; | |
4460 | free_EXPR_LIST_node (temp); | |
4461 | } | |
4462 | else | |
4463 | prev = temp; | |
4464 | temp = next; | |
4465 | } | |
4466 | } | |
4467 | ||
d3a923ee RH |
4468 | /* Process the registers that are set within X. Their bits are set to |
4469 | 1 in the regset DEAD, because they are dead prior to this insn. | |
d7429b6a | 4470 | |
d3a923ee RH |
4471 | If INSN is nonzero, it is the insn being processed. |
4472 | ||
4473 | FLAGS is the set of operations to perform. */ | |
d7429b6a | 4474 | |
d7429b6a | 4475 | static void |
8e3f9094 | 4476 | mark_set_regs (pbi, x, insn) |
62828c00 | 4477 | struct propagate_block_info *pbi; |
62828c00 | 4478 | rtx x, insn; |
d7429b6a | 4479 | { |
62828c00 | 4480 | rtx cond = NULL_RTX; |
8ba7b396 | 4481 | rtx link; |
b4593d17 | 4482 | enum rtx_code code; |
d7429b6a | 4483 | |
8ba7b396 R |
4484 | if (insn) |
4485 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
4486 | { | |
4487 | if (REG_NOTE_KIND (link) == REG_INC) | |
4488 | mark_set_1 (pbi, SET, XEXP (link, 0), | |
4489 | (GET_CODE (x) == COND_EXEC | |
4490 | ? COND_EXEC_TEST (x) : NULL_RTX), | |
4491 | insn, pbi->flags); | |
4492 | } | |
62828c00 | 4493 | retry: |
b4593d17 | 4494 | switch (code = GET_CODE (x)) |
d7429b6a | 4495 | { |
62828c00 RH |
4496 | case SET: |
4497 | case CLOBBER: | |
b4593d17 | 4498 | mark_set_1 (pbi, code, SET_DEST (x), cond, insn, pbi->flags); |
62828c00 RH |
4499 | return; |
4500 | ||
4501 | case COND_EXEC: | |
4502 | cond = COND_EXEC_TEST (x); | |
4503 | x = COND_EXEC_CODE (x); | |
4504 | goto retry; | |
4505 | ||
4506 | case PARALLEL: | |
4507 | { | |
4508 | register int i; | |
4509 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
4510 | { | |
4511 | rtx sub = XVECEXP (x, 0, i); | |
b4593d17 | 4512 | switch (code = GET_CODE (sub)) |
62828c00 RH |
4513 | { |
4514 | case COND_EXEC: | |
4515 | if (cond != NULL_RTX) | |
4516 | abort (); | |
4517 | ||
4518 | cond = COND_EXEC_TEST (sub); | |
4519 | sub = COND_EXEC_CODE (sub); | |
4520 | if (GET_CODE (sub) != SET && GET_CODE (sub) != CLOBBER) | |
4521 | break; | |
c9bacfdb | 4522 | /* Fall through. */ |
62828c00 RH |
4523 | |
4524 | case SET: | |
4525 | case CLOBBER: | |
b4593d17 | 4526 | mark_set_1 (pbi, code, SET_DEST (sub), cond, insn, pbi->flags); |
62828c00 RH |
4527 | break; |
4528 | ||
4529 | default: | |
4530 | break; | |
4531 | } | |
4532 | } | |
4533 | break; | |
4534 | } | |
4535 | ||
4536 | default: | |
4537 | break; | |
d7429b6a RK |
4538 | } |
4539 | } | |
4540 | ||
4541 | /* Process a single SET rtx, X. */ | |
4542 | ||
4543 | static void | |
b4593d17 | 4544 | mark_set_1 (pbi, code, reg, cond, insn, flags) |
62828c00 | 4545 | struct propagate_block_info *pbi; |
b4593d17 | 4546 | enum rtx_code code; |
62828c00 | 4547 | rtx reg, cond, insn; |
b4593d17 | 4548 | int flags; |
d7429b6a | 4549 | { |
b4593d17 | 4550 | int regno_first = -1, regno_last = -1; |
9785c68d | 4551 | int not_dead = 0; |
b4593d17 | 4552 | int i; |
d7429b6a | 4553 | |
86465af7 DM |
4554 | /* Some targets place small structures in registers for |
4555 | return values of functions. We have to detect this | |
4556 | case specially here to get correct flow information. */ | |
4557 | if (GET_CODE (reg) == PARALLEL | |
4558 | && GET_MODE (reg) == BLKmode) | |
4559 | { | |
86465af7 | 4560 | for (i = XVECLEN (reg, 0) - 1; i >= 0; i--) |
b4593d17 | 4561 | mark_set_1 (pbi, code, XVECEXP (reg, 0, i), cond, insn, flags); |
86465af7 DM |
4562 | return; |
4563 | } | |
4564 | ||
8e3f9094 RH |
4565 | /* Modifying just one hardware register of a multi-reg value or just a |
4566 | byte field of a register does not mean the value from before this insn | |
9785c68d | 4567 | is now dead. Of course, if it was dead after it's unused now. */ |
8e3f9094 | 4568 | |
9785c68d RH |
4569 | switch (GET_CODE (reg)) |
4570 | { | |
4571 | case ZERO_EXTRACT: | |
4572 | case SIGN_EXTRACT: | |
4573 | case STRICT_LOW_PART: | |
4574 | /* ??? Assumes STRICT_LOW_PART not used on multi-word registers. */ | |
4575 | do | |
4576 | reg = XEXP (reg, 0); | |
4577 | while (GET_CODE (reg) == SUBREG | |
4578 | || GET_CODE (reg) == ZERO_EXTRACT | |
4579 | || GET_CODE (reg) == SIGN_EXTRACT | |
4580 | || GET_CODE (reg) == STRICT_LOW_PART); | |
1b513b77 JH |
4581 | if (GET_CODE (reg) == MEM) |
4582 | break; | |
9785c68d | 4583 | not_dead = REGNO_REG_SET_P (pbi->reg_live, REGNO (reg)); |
c9bacfdb | 4584 | /* Fall through. */ |
9785c68d RH |
4585 | |
4586 | case REG: | |
4587 | regno_last = regno_first = REGNO (reg); | |
4588 | if (regno_first < FIRST_PSEUDO_REGISTER) | |
4589 | regno_last += HARD_REGNO_NREGS (regno_first, GET_MODE (reg)) - 1; | |
4590 | break; | |
d7429b6a | 4591 | |
9785c68d RH |
4592 | case SUBREG: |
4593 | if (GET_CODE (SUBREG_REG (reg)) == REG) | |
4594 | { | |
4595 | enum machine_mode outer_mode = GET_MODE (reg); | |
4596 | enum machine_mode inner_mode = GET_MODE (SUBREG_REG (reg)); | |
d7429b6a | 4597 | |
9785c68d RH |
4598 | /* Identify the range of registers affected. This is moderately |
4599 | tricky for hard registers. See alter_subreg. */ | |
4600 | ||
4601 | regno_last = regno_first = REGNO (SUBREG_REG (reg)); | |
4602 | if (regno_first < FIRST_PSEUDO_REGISTER) | |
4603 | { | |
4604 | #ifdef ALTER_HARD_SUBREG | |
4605 | regno_first = ALTER_HARD_SUBREG (outer_mode, SUBREG_WORD (reg), | |
4606 | inner_mode, regno_first); | |
4607 | #else | |
4608 | regno_first += SUBREG_WORD (reg); | |
4609 | #endif | |
4610 | regno_last = (regno_first | |
4611 | + HARD_REGNO_NREGS (regno_first, outer_mode) - 1); | |
4612 | ||
4613 | /* Since we've just adjusted the register number ranges, make | |
4614 | sure REG matches. Otherwise some_was_live will be clear | |
4615 | when it shouldn't have been, and we'll create incorrect | |
4616 | REG_UNUSED notes. */ | |
4617 | reg = gen_rtx_REG (outer_mode, regno_first); | |
4618 | } | |
4619 | else | |
4620 | { | |
4621 | /* If the number of words in the subreg is less than the number | |
4622 | of words in the full register, we have a well-defined partial | |
4623 | set. Otherwise the high bits are undefined. | |
4624 | ||
4625 | This is only really applicable to pseudos, since we just took | |
4626 | care of multi-word hard registers. */ | |
4627 | if (((GET_MODE_SIZE (outer_mode) | |
4628 | + UNITS_PER_WORD - 1) / UNITS_PER_WORD) | |
4629 | < ((GET_MODE_SIZE (inner_mode) | |
4630 | + UNITS_PER_WORD - 1) / UNITS_PER_WORD)) | |
4631 | not_dead = REGNO_REG_SET_P (pbi->reg_live, regno_first); | |
4632 | ||
4633 | reg = SUBREG_REG (reg); | |
4634 | } | |
4635 | } | |
4636 | else | |
4637 | reg = SUBREG_REG (reg); | |
4638 | break; | |
4639 | ||
4640 | default: | |
4641 | break; | |
4642 | } | |
d7429b6a | 4643 | |
c9bacfdb | 4644 | /* If this set is a MEM, then it kills any aliased writes. |
db3a887b | 4645 | If this set is a REG, then it kills any MEMs which use the reg. */ |
b2262f4a | 4646 | if (optimize && (flags & PROP_SCAN_DEAD_CODE)) |
db3a887b | 4647 | { |
62828c00 | 4648 | if (GET_CODE (reg) == MEM || GET_CODE (reg) == REG) |
1288c070 | 4649 | invalidate_mems_from_set (pbi, reg); |
15e088b2 | 4650 | |
d3a923ee RH |
4651 | /* If the memory reference had embedded side effects (autoincrement |
4652 | address modes. Then we may need to kill some entries on the | |
4653 | memory set list. */ | |
4654 | if (insn && GET_CODE (reg) == MEM) | |
62828c00 | 4655 | invalidate_mems_from_autoinc (pbi, insn); |
d3a923ee RH |
4656 | |
4657 | if (GET_CODE (reg) == MEM && ! side_effects_p (reg) | |
a0ee3b83 RH |
4658 | /* ??? With more effort we could track conditional memory life. */ |
4659 | && ! cond | |
d3a923ee RH |
4660 | /* We do not know the size of a BLKmode store, so we do not track |
4661 | them for redundant store elimination. */ | |
4662 | && GET_MODE (reg) != BLKmode | |
c9bacfdb | 4663 | /* There are no REG_INC notes for SP, so we can't assume we'll see |
d3a923ee RH |
4664 | everything that invalidates it. To be safe, don't eliminate any |
4665 | stores though SP; none of them should be redundant anyway. */ | |
4666 | && ! reg_mentioned_p (stack_pointer_rtx, reg)) | |
c32e1e6f RH |
4667 | { |
4668 | #ifdef AUTO_INC_DEC | |
4669 | /* Store a copy of mem, otherwise the address may be | |
4670 | scrogged by find_auto_inc. */ | |
4671 | if (flags & PROP_AUTOINC) | |
4672 | reg = shallow_copy_rtx (reg); | |
4673 | #endif | |
4674 | pbi->mem_set_list = alloc_EXPR_LIST (0, reg, pbi->mem_set_list); | |
4675 | } | |
d3a923ee | 4676 | } |
d7429b6a RK |
4677 | |
4678 | if (GET_CODE (reg) == REG | |
9785c68d RH |
4679 | && ! (regno_first == FRAME_POINTER_REGNUM |
4680 | && (! reload_completed || frame_pointer_needed)) | |
73a187c1 | 4681 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
b4593d17 | 4682 | && ! (regno_first == HARD_FRAME_POINTER_REGNUM |
e4b8a413 | 4683 | && (! reload_completed || frame_pointer_needed)) |
73a187c1 | 4684 | #endif |
d7e4fe8b | 4685 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
b4593d17 | 4686 | && ! (regno_first == ARG_POINTER_REGNUM && fixed_regs[regno_first]) |
d7e4fe8b | 4687 | #endif |
62828c00 | 4688 | ) |
d7429b6a | 4689 | { |
b4593d17 | 4690 | int some_was_live = 0, some_was_dead = 0; |
d7429b6a | 4691 | |
b4593d17 RH |
4692 | for (i = regno_first; i <= regno_last; ++i) |
4693 | { | |
4694 | int needed_regno = REGNO_REG_SET_P (pbi->reg_live, i); | |
4695 | if (pbi->local_set) | |
7dfc0fbe BS |
4696 | { |
4697 | /* Order of the set operation matters here since both | |
4698 | sets may be the same. */ | |
4699 | CLEAR_REGNO_REG_SET (pbi->cond_local_set, i); | |
4700 | if (cond != NULL_RTX | |
4701 | && ! REGNO_REG_SET_P (pbi->local_set, i)) | |
4702 | SET_REGNO_REG_SET (pbi->cond_local_set, i); | |
4703 | else | |
4704 | SET_REGNO_REG_SET (pbi->local_set, i); | |
4705 | } | |
9785c68d RH |
4706 | if (code != CLOBBER) |
4707 | SET_REGNO_REG_SET (pbi->new_set, i); | |
b4593d17 RH |
4708 | |
4709 | some_was_live |= needed_regno; | |
4710 | some_was_dead |= ! needed_regno; | |
4711 | } | |
d3a923ee | 4712 | |
11ae508b RH |
4713 | #ifdef HAVE_conditional_execution |
4714 | /* Consider conditional death in deciding that the register needs | |
4715 | a death note. */ | |
f0acaf02 | 4716 | if (some_was_live && ! not_dead |
11ae508b RH |
4717 | /* The stack pointer is never dead. Well, not strictly true, |
4718 | but it's very difficult to tell from here. Hopefully | |
4719 | combine_stack_adjustments will fix up the most egregious | |
4720 | errors. */ | |
4721 | && regno_first != STACK_POINTER_REGNUM) | |
4722 | { | |
4723 | for (i = regno_first; i <= regno_last; ++i) | |
4724 | if (! mark_regno_cond_dead (pbi, i, cond)) | |
4725 | not_dead = 1; | |
4726 | } | |
4727 | #endif | |
4728 | ||
d7429b6a | 4729 | /* Additional data to record if this is the final pass. */ |
d3a923ee RH |
4730 | if (flags & (PROP_LOG_LINKS | PROP_REG_INFO |
4731 | | PROP_DEATH_NOTES | PROP_AUTOINC)) | |
d7429b6a | 4732 | { |
d3a923ee | 4733 | register rtx y; |
62828c00 | 4734 | register int blocknum = pbi->bb->index; |
d7429b6a | 4735 | |
d3a923ee RH |
4736 | y = NULL_RTX; |
4737 | if (flags & (PROP_LOG_LINKS | PROP_AUTOINC)) | |
d7429b6a | 4738 | { |
b4593d17 | 4739 | y = pbi->reg_next_use[regno_first]; |
93514916 | 4740 | |
b4593d17 RH |
4741 | /* The next use is no longer next, since a store intervenes. */ |
4742 | for (i = regno_first; i <= regno_last; ++i) | |
4743 | pbi->reg_next_use[i] = 0; | |
d7429b6a | 4744 | } |
93514916 | 4745 | |
b4593d17 RH |
4746 | if (flags & PROP_REG_INFO) |
4747 | { | |
4748 | for (i = regno_first; i <= regno_last; ++i) | |
d3a923ee | 4749 | { |
b4593d17 | 4750 | /* Count (weighted) references, stores, etc. This counts a |
d3a923ee | 4751 | register twice if it is modified, but that is correct. */ |
b4593d17 RH |
4752 | REG_N_SETS (i) += 1; |
4753 | REG_N_REFS (i) += (optimize_size ? 1 | |
4754 | : pbi->bb->loop_depth + 1); | |
4755 | ||
d3a923ee RH |
4756 | /* The insns where a reg is live are normally counted |
4757 | elsewhere, but we want the count to include the insn | |
4758 | where the reg is set, and the normal counting mechanism | |
4759 | would not count it. */ | |
c9bacfdb | 4760 | REG_LIVE_LENGTH (i) += 1; |
b4593d17 RH |
4761 | } |
4762 | ||
4763 | /* If this is a hard reg, record this function uses the reg. */ | |
4764 | if (regno_first < FIRST_PSEUDO_REGISTER) | |
4765 | { | |
4766 | for (i = regno_first; i <= regno_last; i++) | |
4767 | regs_ever_live[i] = 1; | |
4768 | } | |
4769 | else | |
4770 | { | |
4771 | /* Keep track of which basic blocks each reg appears in. */ | |
4772 | if (REG_BASIC_BLOCK (regno_first) == REG_BLOCK_UNKNOWN) | |
4773 | REG_BASIC_BLOCK (regno_first) = blocknum; | |
4774 | else if (REG_BASIC_BLOCK (regno_first) != blocknum) | |
4775 | REG_BASIC_BLOCK (regno_first) = REG_BLOCK_GLOBAL; | |
d3a923ee | 4776 | } |
d7429b6a RK |
4777 | } |
4778 | ||
62828c00 | 4779 | if (! some_was_dead) |
d7429b6a | 4780 | { |
d3a923ee RH |
4781 | if (flags & PROP_LOG_LINKS) |
4782 | { | |
4783 | /* Make a logical link from the next following insn | |
4784 | that uses this register, back to this insn. | |
4785 | The following insns have already been processed. | |
4786 | ||
4787 | We don't build a LOG_LINK for hard registers containing | |
4788 | in ASM_OPERANDs. If these registers get replaced, | |
4789 | we might wind up changing the semantics of the insn, | |
4790 | even if reload can make what appear to be valid | |
4791 | assignments later. */ | |
4792 | if (y && (BLOCK_NUM (y) == blocknum) | |
b4593d17 | 4793 | && (regno_first >= FIRST_PSEUDO_REGISTER |
d3a923ee RH |
4794 | || asm_noperands (PATTERN (y)) < 0)) |
4795 | LOG_LINKS (y) = alloc_INSN_LIST (insn, LOG_LINKS (y)); | |
4796 | } | |
d7429b6a | 4797 | } |
9785c68d RH |
4798 | else if (not_dead) |
4799 | ; | |
62828c00 | 4800 | else if (! some_was_live) |
d7429b6a | 4801 | { |
d3a923ee | 4802 | if (flags & PROP_REG_INFO) |
b4593d17 | 4803 | REG_N_DEATHS (regno_first) += 1; |
d3a923ee RH |
4804 | |
4805 | if (flags & PROP_DEATH_NOTES) | |
4806 | { | |
4807 | /* Note that dead stores have already been deleted | |
4808 | when possible. If we get here, we have found a | |
4809 | dead store that cannot be eliminated (because the | |
4810 | same insn does something useful). Indicate this | |
4811 | by marking the reg being set as dying here. */ | |
4812 | REG_NOTES (insn) | |
4813 | = alloc_EXPR_LIST (REG_UNUSED, reg, REG_NOTES (insn)); | |
4814 | } | |
d7429b6a RK |
4815 | } |
4816 | else | |
4817 | { | |
d3a923ee RH |
4818 | if (flags & PROP_DEATH_NOTES) |
4819 | { | |
4820 | /* This is a case where we have a multi-word hard register | |
4821 | and some, but not all, of the words of the register are | |
4822 | needed in subsequent insns. Write REG_UNUSED notes | |
4823 | for those parts that were not needed. This case should | |
4824 | be rare. */ | |
4825 | ||
b4593d17 RH |
4826 | for (i = regno_first; i <= regno_last; ++i) |
4827 | if (! REGNO_REG_SET_P (pbi->reg_live, i)) | |
d3a923ee | 4828 | REG_NOTES (insn) |
b4593d17 RH |
4829 | = alloc_EXPR_LIST (REG_UNUSED, |
4830 | gen_rtx_REG (reg_raw_mode[i], i), | |
4831 | REG_NOTES (insn)); | |
d3a923ee | 4832 | } |
d7429b6a RK |
4833 | } |
4834 | } | |
b4593d17 RH |
4835 | |
4836 | /* Mark the register as being dead. */ | |
4837 | if (some_was_live | |
507741dd | 4838 | && ! not_dead |
b4593d17 RH |
4839 | /* The stack pointer is never dead. Well, not strictly true, |
4840 | but it's very difficult to tell from here. Hopefully | |
4841 | combine_stack_adjustments will fix up the most egregious | |
4842 | errors. */ | |
4843 | && regno_first != STACK_POINTER_REGNUM) | |
4844 | { | |
4845 | for (i = regno_first; i <= regno_last; ++i) | |
9785c68d | 4846 | CLEAR_REGNO_REG_SET (pbi->reg_live, i); |
b4593d17 | 4847 | } |
d7429b6a | 4848 | } |
8244fc4f | 4849 | else if (GET_CODE (reg) == REG) |
d3a923ee RH |
4850 | { |
4851 | if (flags & (PROP_LOG_LINKS | PROP_AUTOINC)) | |
b4593d17 | 4852 | pbi->reg_next_use[regno_first] = 0; |
d3a923ee | 4853 | } |
d7429b6a RK |
4854 | |
4855 | /* If this is the last pass and this is a SCRATCH, show it will be dying | |
4856 | here and count it. */ | |
d3a923ee | 4857 | else if (GET_CODE (reg) == SCRATCH) |
d7429b6a | 4858 | { |
d3a923ee RH |
4859 | if (flags & PROP_DEATH_NOTES) |
4860 | REG_NOTES (insn) | |
4861 | = alloc_EXPR_LIST (REG_UNUSED, reg, REG_NOTES (insn)); | |
d7429b6a RK |
4862 | } |
4863 | } | |
4864 | \f | |
11ae508b | 4865 | #ifdef HAVE_conditional_execution |
c9bacfdb KH |
4866 | /* Mark REGNO conditionally dead. |
4867 | Return true if the register is now unconditionally dead. */ | |
11ae508b RH |
4868 | |
4869 | static int | |
4870 | mark_regno_cond_dead (pbi, regno, cond) | |
4871 | struct propagate_block_info *pbi; | |
4872 | int regno; | |
4873 | rtx cond; | |
4874 | { | |
4875 | /* If this is a store to a predicate register, the value of the | |
4876 | predicate is changing, we don't know that the predicate as seen | |
4eb00163 | 4877 | before is the same as that seen after. Flush all dependent |
11ae508b RH |
4878 | conditions from reg_cond_dead. This will make all such |
4879 | conditionally live registers unconditionally live. */ | |
4880 | if (REGNO_REG_SET_P (pbi->reg_cond_reg, regno)) | |
4881 | flush_reg_cond_reg (pbi, regno); | |
4882 | ||
4883 | /* If this is an unconditional store, remove any conditional | |
4884 | life that may have existed. */ | |
4885 | if (cond == NULL_RTX) | |
4886 | splay_tree_remove (pbi->reg_cond_dead, regno); | |
4887 | else | |
4888 | { | |
4889 | splay_tree_node node; | |
4890 | struct reg_cond_life_info *rcli; | |
4891 | rtx ncond; | |
4892 | ||
4893 | /* Otherwise this is a conditional set. Record that fact. | |
4894 | It may have been conditionally used, or there may be a | |
4895 | subsequent set with a complimentary condition. */ | |
4896 | ||
4897 | node = splay_tree_lookup (pbi->reg_cond_dead, regno); | |
4898 | if (node == NULL) | |
4899 | { | |
4900 | /* The register was unconditionally live previously. | |
4901 | Record the current condition as the condition under | |
4902 | which it is dead. */ | |
c9bacfdb | 4903 | rcli = (struct reg_cond_life_info *) xmalloc (sizeof (*rcli)); |
11ae508b RH |
4904 | rcli->condition = alloc_EXPR_LIST (0, cond, NULL_RTX); |
4905 | splay_tree_insert (pbi->reg_cond_dead, regno, | |
4906 | (splay_tree_value) rcli); | |
4907 | ||
7791b7f9 | 4908 | SET_REGNO_REG_SET (pbi->reg_cond_reg, REGNO (XEXP (cond, 0))); |
11ae508b RH |
4909 | |
4910 | /* Not unconditionaly dead. */ | |
4911 | return 0; | |
4912 | } | |
4913 | else | |
4914 | { | |
c9bacfdb | 4915 | /* The register was conditionally live previously. |
11ae508b RH |
4916 | Add the new condition to the old. */ |
4917 | rcli = (struct reg_cond_life_info *) node->value; | |
4918 | ncond = rcli->condition; | |
4919 | ncond = ior_reg_cond (ncond, cond); | |
4920 | ||
4921 | /* If the register is now unconditionally dead, | |
4922 | remove the entry in the splay_tree. */ | |
4923 | if (ncond == const1_rtx) | |
4924 | splay_tree_remove (pbi->reg_cond_dead, regno); | |
4925 | else | |
4926 | { | |
4927 | rcli->condition = ncond; | |
4928 | ||
7791b7f9 | 4929 | SET_REGNO_REG_SET (pbi->reg_cond_reg, REGNO (XEXP (cond, 0))); |
11ae508b RH |
4930 | |
4931 | /* Not unconditionaly dead. */ | |
4932 | return 0; | |
4933 | } | |
4934 | } | |
4935 | } | |
4936 | ||
4937 | return 1; | |
4938 | } | |
4939 | ||
4940 | /* Called from splay_tree_delete for pbi->reg_cond_life. */ | |
4941 | ||
4942 | static void | |
4943 | free_reg_cond_life_info (value) | |
4944 | splay_tree_value value; | |
4945 | { | |
4946 | struct reg_cond_life_info *rcli = (struct reg_cond_life_info *) value; | |
4947 | free_EXPR_LIST_list (&rcli->condition); | |
4948 | free (rcli); | |
4949 | } | |
4950 | ||
4951 | /* Helper function for flush_reg_cond_reg. */ | |
4952 | ||
4953 | static int | |
4954 | flush_reg_cond_reg_1 (node, data) | |
4955 | splay_tree_node node; | |
4956 | void *data; | |
4957 | { | |
4958 | struct reg_cond_life_info *rcli; | |
4959 | int *xdata = (int *) data; | |
4960 | unsigned int regno = xdata[0]; | |
4961 | rtx c, *prev; | |
4962 | ||
4963 | /* Don't need to search if last flushed value was farther on in | |
4964 | the in-order traversal. */ | |
4965 | if (xdata[1] >= (int) node->key) | |
4966 | return 0; | |
4967 | ||
4968 | /* Splice out portions of the expression that refer to regno. */ | |
4969 | rcli = (struct reg_cond_life_info *) node->value; | |
4970 | c = *(prev = &rcli->condition); | |
4971 | while (c) | |
4972 | { | |
4973 | if (regno == REGNO (XEXP (XEXP (c, 0), 0))) | |
4974 | { | |
4975 | rtx next = XEXP (c, 1); | |
4976 | free_EXPR_LIST_node (c); | |
4977 | c = *prev = next; | |
4978 | } | |
4979 | else | |
4980 | c = *(prev = &XEXP (c, 1)); | |
4981 | } | |
4982 | ||
4983 | /* If the entire condition is now NULL, signal the node to be removed. */ | |
4984 | if (! rcli->condition) | |
4985 | { | |
4986 | xdata[1] = node->key; | |
4987 | return -1; | |
4988 | } | |
4989 | else | |
4990 | return 0; | |
4991 | } | |
4992 | ||
4993 | /* Flush all (sub) expressions referring to REGNO from REG_COND_LIVE. */ | |
4994 | ||
4995 | static void | |
4996 | flush_reg_cond_reg (pbi, regno) | |
4997 | struct propagate_block_info *pbi; | |
4998 | int regno; | |
4999 | { | |
5000 | int pair[2]; | |
5001 | ||
5002 | pair[0] = regno; | |
5003 | pair[1] = -1; | |
5004 | while (splay_tree_foreach (pbi->reg_cond_dead, | |
5005 | flush_reg_cond_reg_1, pair) == -1) | |
5006 | splay_tree_remove (pbi->reg_cond_dead, pair[1]); | |
5007 | ||
5008 | CLEAR_REGNO_REG_SET (pbi->reg_cond_reg, regno); | |
5009 | } | |
5010 | ||
5011 | /* Logical arithmetic on predicate conditions. IOR, NOT and NAND. | |
5012 | We actually use EXPR_LIST to chain the sub-expressions together | |
c9bacfdb | 5013 | instead of IOR because it's easier to manipulate and we have |
11ae508b | 5014 | the lists.c functions to reuse nodes. |
c9bacfdb | 5015 | |
11ae508b RH |
5016 | Return a new rtl expression as appropriate. */ |
5017 | ||
5018 | static rtx | |
5019 | ior_reg_cond (old, x) | |
5020 | rtx old, x; | |
5021 | { | |
5022 | enum rtx_code x_code; | |
5023 | rtx x_reg; | |
5024 | rtx c; | |
5025 | ||
5026 | /* We expect these conditions to be of the form (eq reg 0). */ | |
5027 | x_code = GET_CODE (x); | |
5028 | if (GET_RTX_CLASS (x_code) != '<' | |
5029 | || GET_CODE (x_reg = XEXP (x, 0)) != REG | |
5030 | || XEXP (x, 1) != const0_rtx) | |
5031 | abort (); | |
5032 | ||
5033 | /* Search the expression for an existing sub-expression of X_REG. */ | |
c9bacfdb | 5034 | for (c = old; c; c = XEXP (c, 1)) |
11ae508b RH |
5035 | { |
5036 | rtx y = XEXP (c, 0); | |
5037 | if (REGNO (XEXP (y, 0)) == REGNO (x_reg)) | |
5038 | { | |
5039 | /* If we find X already present in OLD, we need do nothing. */ | |
5040 | if (GET_CODE (y) == x_code) | |
5041 | return old; | |
5042 | ||
c9bacfdb | 5043 | /* If we find X being a compliment of a condition in OLD, |
11ae508b RH |
5044 | then the entire condition is true. */ |
5045 | if (GET_CODE (y) == reverse_condition (x_code)) | |
5046 | return const1_rtx; | |
5047 | } | |
5048 | } | |
5049 | ||
5050 | /* Otherwise just add to the chain. */ | |
5051 | return alloc_EXPR_LIST (0, x, old); | |
5052 | } | |
5053 | ||
5054 | static rtx | |
5055 | not_reg_cond (x) | |
5056 | rtx x; | |
5057 | { | |
5058 | enum rtx_code x_code; | |
5059 | rtx x_reg; | |
5060 | ||
5061 | /* We expect these conditions to be of the form (eq reg 0). */ | |
5062 | x_code = GET_CODE (x); | |
5063 | if (GET_RTX_CLASS (x_code) != '<' | |
5064 | || GET_CODE (x_reg = XEXP (x, 0)) != REG | |
5065 | || XEXP (x, 1) != const0_rtx) | |
5066 | abort (); | |
5067 | ||
5068 | return alloc_EXPR_LIST (0, gen_rtx_fmt_ee (reverse_condition (x_code), | |
5069 | VOIDmode, x_reg, const0_rtx), | |
5070 | NULL_RTX); | |
5071 | } | |
5072 | ||
5073 | static rtx | |
5074 | nand_reg_cond (old, x) | |
5075 | rtx old, x; | |
5076 | { | |
5077 | enum rtx_code x_code; | |
5078 | rtx x_reg; | |
5079 | rtx c, *prev; | |
5080 | ||
5081 | /* We expect these conditions to be of the form (eq reg 0). */ | |
5082 | x_code = GET_CODE (x); | |
5083 | if (GET_RTX_CLASS (x_code) != '<' | |
5084 | || GET_CODE (x_reg = XEXP (x, 0)) != REG | |
5085 | || XEXP (x, 1) != const0_rtx) | |
5086 | abort (); | |
5087 | ||
5088 | /* Search the expression for an existing sub-expression of X_REG. */ | |
5089 | ||
c9bacfdb | 5090 | for (c = *(prev = &old); c; c = *(prev = &XEXP (c, 1))) |
11ae508b RH |
5091 | { |
5092 | rtx y = XEXP (c, 0); | |
5093 | if (REGNO (XEXP (y, 0)) == REGNO (x_reg)) | |
5094 | { | |
c9bacfdb | 5095 | /* If we find X already present in OLD, then we need to |
11ae508b RH |
5096 | splice it out. */ |
5097 | if (GET_CODE (y) == x_code) | |
5098 | { | |
5099 | *prev = XEXP (c, 1); | |
5100 | free_EXPR_LIST_node (c); | |
5101 | return old ? old : const0_rtx; | |
5102 | } | |
5103 | ||
c9bacfdb | 5104 | /* If we find X being a compliment of a condition in OLD, |
11ae508b RH |
5105 | then we need do nothing. */ |
5106 | if (GET_CODE (y) == reverse_condition (x_code)) | |
5107 | return old; | |
5108 | } | |
5109 | } | |
5110 | ||
5111 | /* Otherwise, by implication, the register in question is now live for | |
5112 | the inverse of the condition X. */ | |
5113 | return alloc_EXPR_LIST (0, gen_rtx_fmt_ee (reverse_condition (x_code), | |
5114 | VOIDmode, x_reg, const0_rtx), | |
5115 | old); | |
5116 | } | |
5117 | #endif /* HAVE_conditional_execution */ | |
5118 | \f | |
d7429b6a RK |
5119 | #ifdef AUTO_INC_DEC |
5120 | ||
4b983fdc RH |
5121 | /* Try to substitute the auto-inc expression INC as the address inside |
5122 | MEM which occurs in INSN. Currently, the address of MEM is an expression | |
5123 | involving INCR_REG, and INCR is the next use of INCR_REG; it is an insn | |
5124 | that has a single set whose source is a PLUS of INCR_REG and something | |
5125 | else. */ | |
5126 | ||
5127 | static void | |
5128 | attempt_auto_inc (pbi, inc, insn, mem, incr, incr_reg) | |
5129 | struct propagate_block_info *pbi; | |
5130 | rtx inc, insn, mem, incr, incr_reg; | |
5131 | { | |
5132 | int regno = REGNO (incr_reg); | |
5133 | rtx set = single_set (incr); | |
5134 | rtx q = SET_DEST (set); | |
5135 | rtx y = SET_SRC (set); | |
5136 | int opnum = XEXP (y, 0) == incr_reg ? 0 : 1; | |
5137 | ||
5138 | /* Make sure this reg appears only once in this insn. */ | |
5139 | if (count_occurrences (PATTERN (insn), incr_reg, 1) != 1) | |
5140 | return; | |
5141 | ||
5142 | if (dead_or_set_p (incr, incr_reg) | |
5143 | /* Mustn't autoinc an eliminable register. */ | |
5144 | && (regno >= FIRST_PSEUDO_REGISTER | |
5145 | || ! TEST_HARD_REG_BIT (elim_reg_set, regno))) | |
5146 | { | |
5147 | /* This is the simple case. Try to make the auto-inc. If | |
5148 | we can't, we are done. Otherwise, we will do any | |
5149 | needed updates below. */ | |
5150 | if (! validate_change (insn, &XEXP (mem, 0), inc, 0)) | |
5151 | return; | |
5152 | } | |
5153 | else if (GET_CODE (q) == REG | |
5154 | /* PREV_INSN used here to check the semi-open interval | |
5155 | [insn,incr). */ | |
5156 | && ! reg_used_between_p (q, PREV_INSN (insn), incr) | |
5157 | /* We must also check for sets of q as q may be | |
5158 | a call clobbered hard register and there may | |
5159 | be a call between PREV_INSN (insn) and incr. */ | |
5160 | && ! reg_set_between_p (q, PREV_INSN (insn), incr)) | |
5161 | { | |
5162 | /* We have *p followed sometime later by q = p+size. | |
5163 | Both p and q must be live afterward, | |
5164 | and q is not used between INSN and its assignment. | |
5165 | Change it to q = p, ...*q..., q = q+size. | |
5166 | Then fall into the usual case. */ | |
5167 | rtx insns, temp; | |
4b983fdc RH |
5168 | |
5169 | start_sequence (); | |
5170 | emit_move_insn (q, incr_reg); | |
5171 | insns = get_insns (); | |
5172 | end_sequence (); | |
5173 | ||
5174 | if (basic_block_for_insn) | |
5175 | for (temp = insns; temp; temp = NEXT_INSN (temp)) | |
5176 | set_block_for_insn (temp, pbi->bb); | |
5177 | ||
5178 | /* If we can't make the auto-inc, or can't make the | |
5179 | replacement into Y, exit. There's no point in making | |
5180 | the change below if we can't do the auto-inc and doing | |
5181 | so is not correct in the pre-inc case. */ | |
5182 | ||
5183 | XEXP (inc, 0) = q; | |
5184 | validate_change (insn, &XEXP (mem, 0), inc, 1); | |
5185 | validate_change (incr, &XEXP (y, opnum), q, 1); | |
5186 | if (! apply_change_group ()) | |
5187 | return; | |
5188 | ||
5189 | /* We now know we'll be doing this change, so emit the | |
5190 | new insn(s) and do the updates. */ | |
5191 | emit_insns_before (insns, insn); | |
5192 | ||
5193 | if (pbi->bb->head == insn) | |
5194 | pbi->bb->head = insns; | |
5195 | ||
5196 | /* INCR will become a NOTE and INSN won't contain a | |
5197 | use of INCR_REG. If a use of INCR_REG was just placed in | |
c9bacfdb | 5198 | the insn before INSN, make that the next use. |
4b983fdc RH |
5199 | Otherwise, invalidate it. */ |
5200 | if (GET_CODE (PREV_INSN (insn)) == INSN | |
5201 | && GET_CODE (PATTERN (PREV_INSN (insn))) == SET | |
5202 | && SET_SRC (PATTERN (PREV_INSN (insn))) == incr_reg) | |
5203 | pbi->reg_next_use[regno] = PREV_INSN (insn); | |
5204 | else | |
5205 | pbi->reg_next_use[regno] = 0; | |
5206 | ||
5207 | incr_reg = q; | |
5208 | regno = REGNO (q); | |
5209 | ||
5210 | /* REGNO is now used in INCR which is below INSN, but | |
5211 | it previously wasn't live here. If we don't mark | |
5212 | it as live, we'll put a REG_DEAD note for it | |
5213 | on this insn, which is incorrect. */ | |
5214 | SET_REGNO_REG_SET (pbi->reg_live, regno); | |
5215 | ||
5216 | /* If there are any calls between INSN and INCR, show | |
5217 | that REGNO now crosses them. */ | |
5218 | for (temp = insn; temp != incr; temp = NEXT_INSN (temp)) | |
5219 | if (GET_CODE (temp) == CALL_INSN) | |
5220 | REG_N_CALLS_CROSSED (regno)++; | |
5221 | } | |
5222 | else | |
5223 | return; | |
5224 | ||
5225 | /* If we haven't returned, it means we were able to make the | |
5226 | auto-inc, so update the status. First, record that this insn | |
5227 | has an implicit side effect. */ | |
5228 | ||
c9bacfdb | 5229 | REG_NOTES (insn) = alloc_EXPR_LIST (REG_INC, incr_reg, REG_NOTES (insn)); |
4b983fdc RH |
5230 | |
5231 | /* Modify the old increment-insn to simply copy | |
5232 | the already-incremented value of our register. */ | |
5233 | if (! validate_change (incr, &SET_SRC (set), incr_reg, 0)) | |
5234 | abort (); | |
5235 | ||
5236 | /* If that makes it a no-op (copying the register into itself) delete | |
5237 | it so it won't appear to be a "use" and a "set" of this | |
5238 | register. */ | |
5239 | if (REGNO (SET_DEST (set)) == REGNO (incr_reg)) | |
5240 | { | |
5241 | /* If the original source was dead, it's dead now. */ | |
5242 | rtx note; | |
c9bacfdb | 5243 | |
0858c623 | 5244 | while ((note = find_reg_note (incr, REG_DEAD, NULL_RTX)) != NULL_RTX) |
4b983fdc RH |
5245 | { |
5246 | remove_note (incr, note); | |
5247 | if (XEXP (note, 0) != incr_reg) | |
5248 | CLEAR_REGNO_REG_SET (pbi->reg_live, REGNO (XEXP (note, 0))); | |
5249 | } | |
5250 | ||
5251 | PUT_CODE (incr, NOTE); | |
5252 | NOTE_LINE_NUMBER (incr) = NOTE_INSN_DELETED; | |
5253 | NOTE_SOURCE_FILE (incr) = 0; | |
5254 | } | |
5255 | ||
5256 | if (regno >= FIRST_PSEUDO_REGISTER) | |
5257 | { | |
5258 | /* Count an extra reference to the reg. When a reg is | |
5259 | incremented, spilling it is worse, so we want to make | |
5260 | that less likely. */ | |
5261 | REG_N_REFS (regno) += (optimize_size ? 1 : pbi->bb->loop_depth + 1); | |
5262 | ||
5263 | /* Count the increment as a setting of the register, | |
5264 | even though it isn't a SET in rtl. */ | |
5265 | REG_N_SETS (regno)++; | |
5266 | } | |
5267 | } | |
5268 | ||
d7429b6a RK |
5269 | /* X is a MEM found in INSN. See if we can convert it into an auto-increment |
5270 | reference. */ | |
5271 | ||
5272 | static void | |
62828c00 RH |
5273 | find_auto_inc (pbi, x, insn) |
5274 | struct propagate_block_info *pbi; | |
d7429b6a RK |
5275 | rtx x; |
5276 | rtx insn; | |
5277 | { | |
5278 | rtx addr = XEXP (x, 0); | |
e658434c | 5279 | HOST_WIDE_INT offset = 0; |
4b983fdc RH |
5280 | rtx set, y, incr, inc_val; |
5281 | int regno; | |
5282 | int size = GET_MODE_SIZE (GET_MODE (x)); | |
5283 | ||
5284 | if (GET_CODE (insn) == JUMP_INSN) | |
5285 | return; | |
d7429b6a RK |
5286 | |
5287 | /* Here we detect use of an index register which might be good for | |
5288 | postincrement, postdecrement, preincrement, or predecrement. */ | |
5289 | ||
5290 | if (GET_CODE (addr) == PLUS && GET_CODE (XEXP (addr, 1)) == CONST_INT) | |
5291 | offset = INTVAL (XEXP (addr, 1)), addr = XEXP (addr, 0); | |
5292 | ||
4b983fdc RH |
5293 | if (GET_CODE (addr) != REG) |
5294 | return; | |
d7429b6a | 5295 | |
4b983fdc | 5296 | regno = REGNO (addr); |
7280c2a4 | 5297 | |
4b983fdc RH |
5298 | /* Is the next use an increment that might make auto-increment? */ |
5299 | incr = pbi->reg_next_use[regno]; | |
5300 | if (incr == 0 || BLOCK_NUM (incr) != BLOCK_NUM (insn)) | |
5301 | return; | |
5302 | set = single_set (incr); | |
5303 | if (set == 0 || GET_CODE (set) != SET) | |
5304 | return; | |
5305 | y = SET_SRC (set); | |
7280c2a4 | 5306 | |
4b983fdc RH |
5307 | if (GET_CODE (y) != PLUS) |
5308 | return; | |
7280c2a4 | 5309 | |
66ed03f8 | 5310 | if (REG_P (XEXP (y, 0)) && REGNO (XEXP (y, 0)) == REGNO (addr)) |
4b983fdc | 5311 | inc_val = XEXP (y, 1); |
66ed03f8 | 5312 | else if (REG_P (XEXP (y, 1)) && REGNO (XEXP (y, 1)) == REGNO (addr)) |
4b983fdc RH |
5313 | inc_val = XEXP (y, 0); |
5314 | else | |
66ed03f8 | 5315 | return; |
d7429b6a | 5316 | |
4b983fdc RH |
5317 | if (GET_CODE (inc_val) == CONST_INT) |
5318 | { | |
5319 | if (HAVE_POST_INCREMENT | |
5320 | && (INTVAL (inc_val) == size && offset == 0)) | |
5321 | attempt_auto_inc (pbi, gen_rtx_POST_INC (Pmode, addr), insn, x, | |
5322 | incr, addr); | |
5323 | else if (HAVE_POST_DECREMENT | |
c9bacfdb | 5324 | && (INTVAL (inc_val) == -size && offset == 0)) |
4b983fdc RH |
5325 | attempt_auto_inc (pbi, gen_rtx_POST_DEC (Pmode, addr), insn, x, |
5326 | incr, addr); | |
5327 | else if (HAVE_PRE_INCREMENT | |
5328 | && (INTVAL (inc_val) == size && offset == size)) | |
5329 | attempt_auto_inc (pbi, gen_rtx_PRE_INC (Pmode, addr), insn, x, | |
5330 | incr, addr); | |
5331 | else if (HAVE_PRE_DECREMENT | |
c9bacfdb | 5332 | && (INTVAL (inc_val) == -size && offset == -size)) |
4b983fdc RH |
5333 | attempt_auto_inc (pbi, gen_rtx_PRE_DEC (Pmode, addr), insn, x, |
5334 | incr, addr); | |
5335 | else if (HAVE_POST_MODIFY_DISP && offset == 0) | |
5336 | attempt_auto_inc (pbi, gen_rtx_POST_MODIFY (Pmode, addr, | |
5337 | gen_rtx_PLUS (Pmode, | |
5338 | addr, | |
5339 | inc_val)), | |
5340 | insn, x, incr, addr); | |
5341 | } | |
5342 | else if (GET_CODE (inc_val) == REG | |
5343 | && ! reg_set_between_p (inc_val, PREV_INSN (insn), | |
5344 | NEXT_INSN (incr))) | |
7280c2a4 | 5345 | |
4b983fdc RH |
5346 | { |
5347 | if (HAVE_POST_MODIFY_REG && offset == 0) | |
5348 | attempt_auto_inc (pbi, gen_rtx_POST_MODIFY (Pmode, addr, | |
5349 | gen_rtx_PLUS (Pmode, | |
5350 | addr, | |
5351 | inc_val)), | |
5352 | insn, x, incr, addr); | |
d7429b6a RK |
5353 | } |
5354 | } | |
4b983fdc | 5355 | |
d7429b6a RK |
5356 | #endif /* AUTO_INC_DEC */ |
5357 | \f | |
62828c00 | 5358 | static void |
8e3f9094 | 5359 | mark_used_reg (pbi, reg, cond, insn) |
62828c00 | 5360 | struct propagate_block_info *pbi; |
62828c00 RH |
5361 | rtx reg; |
5362 | rtx cond ATTRIBUTE_UNUSED; | |
5363 | rtx insn; | |
5364 | { | |
5365 | int regno = REGNO (reg); | |
5366 | int some_was_live = REGNO_REG_SET_P (pbi->reg_live, regno); | |
5367 | int some_was_dead = ! some_was_live; | |
9785c68d RH |
5368 | int some_not_set; |
5369 | int n; | |
62828c00 RH |
5370 | |
5371 | /* A hard reg in a wide mode may really be multiple registers. | |
5372 | If so, mark all of them just like the first. */ | |
5373 | if (regno < FIRST_PSEUDO_REGISTER) | |
5374 | { | |
9785c68d | 5375 | n = HARD_REGNO_NREGS (regno, GET_MODE (reg)); |
62828c00 RH |
5376 | while (--n > 0) |
5377 | { | |
9785c68d | 5378 | int needed_regno = REGNO_REG_SET_P (pbi->reg_live, regno + n); |
62828c00 RH |
5379 | some_was_live |= needed_regno; |
5380 | some_was_dead |= ! needed_regno; | |
5381 | } | |
5382 | } | |
5383 | ||
5384 | if (pbi->flags & (PROP_LOG_LINKS | PROP_AUTOINC)) | |
5385 | { | |
5386 | /* Record where each reg is used, so when the reg is set we know | |
5387 | the next insn that uses it. */ | |
5388 | pbi->reg_next_use[regno] = insn; | |
5389 | } | |
5390 | ||
5391 | if (pbi->flags & PROP_REG_INFO) | |
5392 | { | |
5393 | if (regno < FIRST_PSEUDO_REGISTER) | |
5394 | { | |
5395 | /* If this is a register we are going to try to eliminate, | |
5396 | don't mark it live here. If we are successful in | |
5397 | eliminating it, it need not be live unless it is used for | |
5398 | pseudos, in which case it will have been set live when it | |
5399 | was allocated to the pseudos. If the register will not | |
5400 | be eliminated, reload will set it live at that point. | |
5401 | ||
5402 | Otherwise, record that this function uses this register. */ | |
b2433fcd RH |
5403 | /* ??? The PPC backend tries to "eliminate" on the pic |
5404 | register to itself. This should be fixed. In the mean | |
5405 | time, hack around it. */ | |
d7429b6a | 5406 | |
b2433fcd RH |
5407 | if (! (TEST_HARD_REG_BIT (elim_reg_set, regno) |
5408 | && (regno == FRAME_POINTER_REGNUM | |
5409 | || regno == ARG_POINTER_REGNUM))) | |
62828c00 RH |
5410 | { |
5411 | int n = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
62828c00 RH |
5412 | do |
5413 | regs_ever_live[regno + --n] = 1; | |
5414 | while (n > 0); | |
5415 | } | |
5416 | } | |
5417 | else | |
5418 | { | |
5419 | /* Keep track of which basic block each reg appears in. */ | |
5420 | ||
5421 | register int blocknum = pbi->bb->index; | |
5422 | if (REG_BASIC_BLOCK (regno) == REG_BLOCK_UNKNOWN) | |
5423 | REG_BASIC_BLOCK (regno) = blocknum; | |
5424 | else if (REG_BASIC_BLOCK (regno) != blocknum) | |
5425 | REG_BASIC_BLOCK (regno) = REG_BLOCK_GLOBAL; | |
5426 | ||
5427 | /* Count (weighted) number of uses of each reg. */ | |
ebfe71a8 NC |
5428 | REG_N_REFS (regno) += (optimize_size ? 1 |
5429 | : pbi->bb->loop_depth + 1); | |
62828c00 RH |
5430 | } |
5431 | } | |
d7429b6a | 5432 | |
9785c68d RH |
5433 | /* Find out if any of the register was set this insn. */ |
5434 | some_not_set = ! REGNO_REG_SET_P (pbi->new_set, regno); | |
5435 | if (regno < FIRST_PSEUDO_REGISTER) | |
5436 | { | |
5437 | n = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
5438 | while (--n > 0) | |
5439 | some_not_set |= ! REGNO_REG_SET_P (pbi->new_set, regno + n); | |
5440 | } | |
5441 | ||
62828c00 RH |
5442 | /* Record and count the insns in which a reg dies. If it is used in |
5443 | this insn and was dead below the insn then it dies in this insn. | |
5444 | If it was set in this insn, we do not make a REG_DEAD note; | |
9785c68d RH |
5445 | likewise if we already made such a note. */ |
5446 | if ((pbi->flags & (PROP_DEATH_NOTES | PROP_REG_INFO)) | |
62828c00 | 5447 | && some_was_dead |
9785c68d | 5448 | && some_not_set) |
62828c00 | 5449 | { |
62828c00 RH |
5450 | /* Check for the case where the register dying partially |
5451 | overlaps the register set by this insn. */ | |
5452 | if (regno < FIRST_PSEUDO_REGISTER | |
5453 | && HARD_REGNO_NREGS (regno, GET_MODE (reg)) > 1) | |
5454 | { | |
5455 | n = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
5456 | while (--n >= 0) | |
9785c68d | 5457 | some_was_live |= REGNO_REG_SET_P (pbi->new_set, regno + n); |
62828c00 RH |
5458 | } |
5459 | ||
5460 | /* If none of the words in X is needed, make a REG_DEAD note. | |
5461 | Otherwise, we must make partial REG_DEAD notes. */ | |
5462 | if (! some_was_live) | |
5463 | { | |
9785c68d RH |
5464 | if ((pbi->flags & PROP_DEATH_NOTES) |
5465 | && ! find_regno_note (insn, REG_DEAD, regno)) | |
5466 | REG_NOTES (insn) | |
5467 | = alloc_EXPR_LIST (REG_DEAD, reg, REG_NOTES (insn)); | |
5468 | ||
5469 | if (pbi->flags & PROP_REG_INFO) | |
5470 | REG_N_DEATHS (regno)++; | |
62828c00 RH |
5471 | } |
5472 | else | |
5473 | { | |
5474 | /* Don't make a REG_DEAD note for a part of a register | |
5475 | that is set in the insn. */ | |
5476 | ||
5477 | n = regno + HARD_REGNO_NREGS (regno, GET_MODE (reg)) - 1; | |
5478 | for (; n >= regno; n--) | |
9785c68d | 5479 | if (! REGNO_REG_SET_P (pbi->reg_live, n) |
62828c00 RH |
5480 | && ! dead_or_set_regno_p (insn, n)) |
5481 | REG_NOTES (insn) | |
5482 | = alloc_EXPR_LIST (REG_DEAD, | |
5483 | gen_rtx_REG (reg_raw_mode[n], n), | |
5484 | REG_NOTES (insn)); | |
5485 | } | |
5486 | } | |
9785c68d RH |
5487 | |
5488 | SET_REGNO_REG_SET (pbi->reg_live, regno); | |
5489 | if (regno < FIRST_PSEUDO_REGISTER) | |
5490 | { | |
5491 | n = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
5492 | while (--n > 0) | |
5493 | SET_REGNO_REG_SET (pbi->reg_live, regno + n); | |
5494 | } | |
11ae508b RH |
5495 | |
5496 | #ifdef HAVE_conditional_execution | |
5497 | /* If this is a conditional use, record that fact. If it is later | |
5498 | conditionally set, we'll know to kill the register. */ | |
5499 | if (cond != NULL_RTX) | |
5500 | { | |
5501 | splay_tree_node node; | |
5502 | struct reg_cond_life_info *rcli; | |
5503 | rtx ncond; | |
5504 | ||
5505 | if (some_was_live) | |
5506 | { | |
5507 | node = splay_tree_lookup (pbi->reg_cond_dead, regno); | |
5508 | if (node == NULL) | |
5509 | { | |
5510 | /* The register was unconditionally live previously. | |
5511 | No need to do anything. */ | |
5512 | } | |
5513 | else | |
5514 | { | |
c9bacfdb | 5515 | /* The register was conditionally live previously. |
11ae508b RH |
5516 | Subtract the new life cond from the old death cond. */ |
5517 | rcli = (struct reg_cond_life_info *) node->value; | |
5518 | ncond = rcli->condition; | |
5519 | ncond = nand_reg_cond (ncond, cond); | |
5520 | ||
5521 | /* If the register is now unconditionally live, remove the | |
5522 | entry in the splay_tree. */ | |
5523 | if (ncond == const0_rtx) | |
5524 | { | |
5525 | rcli->condition = NULL_RTX; | |
5526 | splay_tree_remove (pbi->reg_cond_dead, regno); | |
5527 | } | |
5528 | else | |
7791b7f9 RH |
5529 | { |
5530 | rcli->condition = ncond; | |
5531 | SET_REGNO_REG_SET (pbi->reg_cond_reg, REGNO (XEXP (cond, 0))); | |
5532 | } | |
11ae508b RH |
5533 | } |
5534 | } | |
5535 | else | |
5536 | { | |
5537 | /* The register was not previously live at all. Record | |
5538 | the condition under which it is still dead. */ | |
5539 | rcli = (struct reg_cond_life_info *) xmalloc (sizeof (*rcli)); | |
5540 | rcli->condition = not_reg_cond (cond); | |
5541 | splay_tree_insert (pbi->reg_cond_dead, regno, | |
5542 | (splay_tree_value) rcli); | |
7791b7f9 RH |
5543 | |
5544 | SET_REGNO_REG_SET (pbi->reg_cond_reg, REGNO (XEXP (cond, 0))); | |
11ae508b RH |
5545 | } |
5546 | } | |
6a3dbe65 RE |
5547 | else if (some_was_live) |
5548 | { | |
5549 | splay_tree_node node; | |
5550 | struct reg_cond_life_info *rcli; | |
5551 | ||
5552 | node = splay_tree_lookup (pbi->reg_cond_dead, regno); | |
5553 | if (node != NULL) | |
5554 | { | |
5555 | /* The register was conditionally live previously, but is now | |
5556 | unconditionally so. Remove it from the conditionally dead | |
5557 | list, so that a conditional set won't cause us to think | |
5558 | it dead. */ | |
5559 | rcli = (struct reg_cond_life_info *) node->value; | |
5560 | rcli->condition = NULL_RTX; | |
5561 | splay_tree_remove (pbi->reg_cond_dead, regno); | |
5562 | } | |
5563 | } | |
5564 | ||
11ae508b | 5565 | #endif |
62828c00 RH |
5566 | } |
5567 | ||
5568 | /* Scan expression X and store a 1-bit in NEW_LIVE for each reg it uses. | |
5569 | This is done assuming the registers needed from X are those that | |
5570 | have 1-bits in PBI->REG_LIVE. | |
5571 | ||
5572 | INSN is the containing instruction. If INSN is dead, this function | |
5573 | is not called. */ | |
d7429b6a RK |
5574 | |
5575 | static void | |
8e3f9094 | 5576 | mark_used_regs (pbi, x, cond, insn) |
62828c00 | 5577 | struct propagate_block_info *pbi; |
62828c00 | 5578 | rtx x, cond, insn; |
d7429b6a RK |
5579 | { |
5580 | register RTX_CODE code; | |
5581 | register int regno; | |
62828c00 | 5582 | int flags = pbi->flags; |
d7429b6a RK |
5583 | |
5584 | retry: | |
5585 | code = GET_CODE (x); | |
5586 | switch (code) | |
5587 | { | |
5588 | case LABEL_REF: | |
5589 | case SYMBOL_REF: | |
5590 | case CONST_INT: | |
5591 | case CONST: | |
5592 | case CONST_DOUBLE: | |
5593 | case PC: | |
d7429b6a RK |
5594 | case ADDR_VEC: |
5595 | case ADDR_DIFF_VEC: | |
d7429b6a RK |
5596 | return; |
5597 | ||
5598 | #ifdef HAVE_cc0 | |
5599 | case CC0: | |
62828c00 | 5600 | pbi->cc0_live = 1; |
d7429b6a RK |
5601 | return; |
5602 | #endif | |
5603 | ||
2f1553a4 RK |
5604 | case CLOBBER: |
5605 | /* If we are clobbering a MEM, mark any registers inside the address | |
5606 | as being used. */ | |
5607 | if (GET_CODE (XEXP (x, 0)) == MEM) | |
8e3f9094 | 5608 | mark_used_regs (pbi, XEXP (XEXP (x, 0), 0), cond, insn); |
2f1553a4 RK |
5609 | return; |
5610 | ||
d7429b6a | 5611 | case MEM: |
c9bacfdb | 5612 | /* Don't bother watching stores to mems if this is not the |
d3a923ee | 5613 | final pass. We'll not be deleting dead stores this round. */ |
b2262f4a | 5614 | if (optimize && (flags & PROP_SCAN_DEAD_CODE)) |
db3a887b | 5615 | { |
c9bacfdb | 5616 | /* Invalidate the data for the last MEM stored, but only if MEM is |
d3a923ee | 5617 | something that can be stored into. */ |
c9bacfdb | 5618 | if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF |
d3a923ee | 5619 | && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0))) |
c9bacfdb KH |
5620 | /* Needn't clear the memory set list. */ |
5621 | ; | |
5622 | else | |
db3a887b | 5623 | { |
62828c00 | 5624 | rtx temp = pbi->mem_set_list; |
d3a923ee | 5625 | rtx prev = NULL_RTX; |
ff666313 | 5626 | rtx next; |
d3a923ee RH |
5627 | |
5628 | while (temp) | |
db3a887b | 5629 | { |
ff666313 | 5630 | next = XEXP (temp, 1); |
d3a923ee RH |
5631 | if (anti_dependence (XEXP (temp, 0), x)) |
5632 | { | |
5633 | /* Splice temp out of the list. */ | |
5634 | if (prev) | |
ff666313 | 5635 | XEXP (prev, 1) = next; |
d3a923ee | 5636 | else |
62828c00 | 5637 | pbi->mem_set_list = next; |
ff666313 | 5638 | free_EXPR_LIST_node (temp); |
d3a923ee | 5639 | } |
db3a887b | 5640 | else |
d3a923ee | 5641 | prev = temp; |
ff666313 | 5642 | temp = next; |
db3a887b | 5643 | } |
db3a887b | 5644 | } |
d7429b6a | 5645 | |
d3a923ee RH |
5646 | /* If the memory reference had embedded side effects (autoincrement |
5647 | address modes. Then we may need to kill some entries on the | |
5648 | memory set list. */ | |
5649 | if (insn) | |
62828c00 | 5650 | invalidate_mems_from_autoinc (pbi, insn); |
d3a923ee | 5651 | } |
15e088b2 | 5652 | |
d7429b6a | 5653 | #ifdef AUTO_INC_DEC |
61f286b6 | 5654 | if (flags & PROP_AUTOINC) |
62828c00 | 5655 | find_auto_inc (pbi, x, insn); |
d7429b6a RK |
5656 | #endif |
5657 | break; | |
5658 | ||
80f8f04a | 5659 | case SUBREG: |
02188693 | 5660 | #ifdef CLASS_CANNOT_CHANGE_MODE |
80f8f04a RK |
5661 | if (GET_CODE (SUBREG_REG (x)) == REG |
5662 | && REGNO (SUBREG_REG (x)) >= FIRST_PSEUDO_REGISTER | |
02188693 RH |
5663 | && CLASS_CANNOT_CHANGE_MODE_P (GET_MODE (x), |
5664 | GET_MODE (SUBREG_REG (x)))) | |
5665 | REG_CHANGES_MODE (REGNO (SUBREG_REG (x))) = 1; | |
5666 | #endif | |
80f8f04a RK |
5667 | |
5668 | /* While we're here, optimize this case. */ | |
5669 | x = SUBREG_REG (x); | |
ce79abf3 | 5670 | if (GET_CODE (x) != REG) |
62828c00 | 5671 | goto retry; |
c9bacfdb | 5672 | /* Fall through. */ |
80f8f04a | 5673 | |
d7429b6a | 5674 | case REG: |
62828c00 | 5675 | /* See a register other than being set => mark it as needed. */ |
8e3f9094 | 5676 | mark_used_reg (pbi, x, cond, insn); |
d7429b6a RK |
5677 | return; |
5678 | ||
5679 | case SET: | |
5680 | { | |
5681 | register rtx testreg = SET_DEST (x); | |
5682 | int mark_dest = 0; | |
5683 | ||
5684 | /* If storing into MEM, don't show it as being used. But do | |
5685 | show the address as being used. */ | |
5686 | if (GET_CODE (testreg) == MEM) | |
5687 | { | |
5688 | #ifdef AUTO_INC_DEC | |
61f286b6 | 5689 | if (flags & PROP_AUTOINC) |
62828c00 | 5690 | find_auto_inc (pbi, testreg, insn); |
d7429b6a | 5691 | #endif |
8e3f9094 RH |
5692 | mark_used_regs (pbi, XEXP (testreg, 0), cond, insn); |
5693 | mark_used_regs (pbi, SET_SRC (x), cond, insn); | |
d7429b6a RK |
5694 | return; |
5695 | } | |
c9bacfdb | 5696 | |
d7429b6a RK |
5697 | /* Storing in STRICT_LOW_PART is like storing in a reg |
5698 | in that this SET might be dead, so ignore it in TESTREG. | |
5699 | but in some other ways it is like using the reg. | |
5700 | ||
5701 | Storing in a SUBREG or a bit field is like storing the entire | |
5702 | register in that if the register's value is not used | |
5703 | then this SET is not needed. */ | |
5704 | while (GET_CODE (testreg) == STRICT_LOW_PART | |
5705 | || GET_CODE (testreg) == ZERO_EXTRACT | |
5706 | || GET_CODE (testreg) == SIGN_EXTRACT | |
5707 | || GET_CODE (testreg) == SUBREG) | |
5708 | { | |
02188693 | 5709 | #ifdef CLASS_CANNOT_CHANGE_MODE |
88285acf RK |
5710 | if (GET_CODE (testreg) == SUBREG |
5711 | && GET_CODE (SUBREG_REG (testreg)) == REG | |
5712 | && REGNO (SUBREG_REG (testreg)) >= FIRST_PSEUDO_REGISTER | |
02188693 RH |
5713 | && CLASS_CANNOT_CHANGE_MODE_P (GET_MODE (SUBREG_REG (testreg)), |
5714 | GET_MODE (testreg))) | |
5715 | REG_CHANGES_MODE (REGNO (SUBREG_REG (testreg))) = 1; | |
5716 | #endif | |
88285acf | 5717 | |
d7429b6a RK |
5718 | /* Modifying a single register in an alternate mode |
5719 | does not use any of the old value. But these other | |
5720 | ways of storing in a register do use the old value. */ | |
5721 | if (GET_CODE (testreg) == SUBREG | |
5722 | && !(REG_SIZE (SUBREG_REG (testreg)) > REG_SIZE (testreg))) | |
5723 | ; | |
5724 | else | |
5725 | mark_dest = 1; | |
5726 | ||
5727 | testreg = XEXP (testreg, 0); | |
5728 | } | |
5729 | ||
62828c00 RH |
5730 | /* If this is a store into a register, recursively scan the |
5731 | value being stored. */ | |
d7429b6a | 5732 | |
86465af7 DM |
5733 | if ((GET_CODE (testreg) == PARALLEL |
5734 | && GET_MODE (testreg) == BLKmode) | |
5735 | || (GET_CODE (testreg) == REG | |
62828c00 RH |
5736 | && (regno = REGNO (testreg), |
5737 | ! (regno == FRAME_POINTER_REGNUM | |
5738 | && (! reload_completed || frame_pointer_needed))) | |
73a187c1 | 5739 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
e4b8a413 JW |
5740 | && ! (regno == HARD_FRAME_POINTER_REGNUM |
5741 | && (! reload_completed || frame_pointer_needed)) | |
73a187c1 | 5742 | #endif |
d7e4fe8b | 5743 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
86465af7 | 5744 | && ! (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) |
d7e4fe8b | 5745 | #endif |
86465af7 | 5746 | )) |
d7429b6a | 5747 | { |
d7429b6a | 5748 | if (mark_dest) |
8e3f9094 RH |
5749 | mark_used_regs (pbi, SET_DEST (x), cond, insn); |
5750 | mark_used_regs (pbi, SET_SRC (x), cond, insn); | |
d7429b6a RK |
5751 | return; |
5752 | } | |
5753 | } | |
5754 | break; | |
5755 | ||
40b5a77c JL |
5756 | case ASM_OPERANDS: |
5757 | case UNSPEC_VOLATILE: | |
5758 | case TRAP_IF: | |
5759 | case ASM_INPUT: | |
5760 | { | |
5761 | /* Traditional and volatile asm instructions must be considered to use | |
5762 | and clobber all hard registers, all pseudo-registers and all of | |
5763 | memory. So must TRAP_IF and UNSPEC_VOLATILE operations. | |
5764 | ||
5765 | Consider for instance a volatile asm that changes the fpu rounding | |
5766 | mode. An insn should not be moved across this even if it only uses | |
c9bacfdb | 5767 | pseudo-regs because it might give an incorrectly rounded result. |
40b5a77c JL |
5768 | |
5769 | ?!? Unfortunately, marking all hard registers as live causes massive | |
5770 | problems for the register allocator and marking all pseudos as live | |
5771 | creates mountains of uninitialized variable warnings. | |
5772 | ||
5773 | So for now, just clear the memory set list and mark any regs | |
5774 | we can find in ASM_OPERANDS as used. */ | |
5775 | if (code != ASM_OPERANDS || MEM_VOLATILE_P (x)) | |
62828c00 | 5776 | free_EXPR_LIST_list (&pbi->mem_set_list); |
40b5a77c | 5777 | |
c9bacfdb | 5778 | /* For all ASM_OPERANDS, we must traverse the vector of input operands. |
40b5a77c JL |
5779 | We can not just fall through here since then we would be confused |
5780 | by the ASM_INPUT rtx inside ASM_OPERANDS, which do not indicate | |
5781 | traditional asms unlike their normal usage. */ | |
5782 | if (code == ASM_OPERANDS) | |
5783 | { | |
5784 | int j; | |
5785 | ||
5786 | for (j = 0; j < ASM_OPERANDS_INPUT_LENGTH (x); j++) | |
8e3f9094 | 5787 | mark_used_regs (pbi, ASM_OPERANDS_INPUT (x, j), cond, insn); |
40b5a77c JL |
5788 | } |
5789 | break; | |
5790 | } | |
5791 | ||
62828c00 RH |
5792 | case COND_EXEC: |
5793 | if (cond != NULL_RTX) | |
5794 | abort (); | |
5795 | ||
8e3f9094 | 5796 | mark_used_regs (pbi, COND_EXEC_TEST (x), NULL_RTX, insn); |
62828c00 RH |
5797 | |
5798 | cond = COND_EXEC_TEST (x); | |
5799 | x = COND_EXEC_CODE (x); | |
5800 | goto retry; | |
5801 | ||
4e872036 AS |
5802 | case PHI: |
5803 | /* We _do_not_ want to scan operands of phi nodes. Operands of | |
5804 | a phi function are evaluated only when control reaches this | |
5805 | block along a particular edge. Therefore, regs that appear | |
5806 | as arguments to phi should not be added to the global live at | |
5807 | start. */ | |
5808 | return; | |
40b5a77c | 5809 | |
e9a25f70 JL |
5810 | default: |
5811 | break; | |
d7429b6a RK |
5812 | } |
5813 | ||
5814 | /* Recursively scan the operands of this expression. */ | |
5815 | ||
5816 | { | |
6f7d635c | 5817 | register const char *fmt = GET_RTX_FORMAT (code); |
d7429b6a | 5818 | register int i; |
c9bacfdb | 5819 | |
d7429b6a RK |
5820 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) |
5821 | { | |
5822 | if (fmt[i] == 'e') | |
5823 | { | |
5824 | /* Tail recursive case: save a function call level. */ | |
5825 | if (i == 0) | |
5826 | { | |
5827 | x = XEXP (x, 0); | |
5828 | goto retry; | |
5829 | } | |
8e3f9094 | 5830 | mark_used_regs (pbi, XEXP (x, i), cond, insn); |
d7429b6a RK |
5831 | } |
5832 | else if (fmt[i] == 'E') | |
5833 | { | |
5834 | register int j; | |
5835 | for (j = 0; j < XVECLEN (x, i); j++) | |
8e3f9094 | 5836 | mark_used_regs (pbi, XVECEXP (x, i, j), cond, insn); |
d7429b6a RK |
5837 | } |
5838 | } | |
5839 | } | |
5840 | } | |
5841 | \f | |
5842 | #ifdef AUTO_INC_DEC | |
5843 | ||
5844 | static int | |
62828c00 RH |
5845 | try_pre_increment_1 (pbi, insn) |
5846 | struct propagate_block_info *pbi; | |
d7429b6a RK |
5847 | rtx insn; |
5848 | { | |
5849 | /* Find the next use of this reg. If in same basic block, | |
5850 | make it do pre-increment or pre-decrement if appropriate. */ | |
956d6950 | 5851 | rtx x = single_set (insn); |
5f4f0e22 | 5852 | HOST_WIDE_INT amount = ((GET_CODE (SET_SRC (x)) == PLUS ? 1 : -1) |
c9bacfdb | 5853 | * INTVAL (XEXP (SET_SRC (x), 1))); |
d7429b6a | 5854 | int regno = REGNO (SET_DEST (x)); |
62828c00 | 5855 | rtx y = pbi->reg_next_use[regno]; |
d7429b6a | 5856 | if (y != 0 |
24948ccc | 5857 | && SET_DEST (x) != stack_pointer_rtx |
d7429b6a | 5858 | && BLOCK_NUM (y) == BLOCK_NUM (insn) |
89861c38 | 5859 | /* Don't do this if the reg dies, or gets set in y; a standard addressing |
0f41302f | 5860 | mode would be better. */ |
89861c38 | 5861 | && ! dead_or_set_p (y, SET_DEST (x)) |
956d6950 | 5862 | && try_pre_increment (y, SET_DEST (x), amount)) |
d7429b6a | 5863 | { |
1288c070 RH |
5864 | /* We have found a suitable auto-increment and already changed |
5865 | insn Y to do it. So flush this increment instruction. */ | |
5866 | propagate_block_delete_insn (pbi->bb, insn); | |
5867 | ||
5868 | /* Count a reference to this reg for the increment insn we are | |
5869 | deleting. When a reg is incremented, spilling it is worse, | |
5870 | so we want to make that less likely. */ | |
d7429b6a RK |
5871 | if (regno >= FIRST_PSEUDO_REGISTER) |
5872 | { | |
ebfe71a8 NC |
5873 | REG_N_REFS (regno) += (optimize_size ? 1 |
5874 | : pbi->bb->loop_depth + 1); | |
b1f21e0a | 5875 | REG_N_SETS (regno)++; |
d7429b6a | 5876 | } |
1288c070 RH |
5877 | |
5878 | /* Flush any remembered memories depending on the value of | |
5879 | the incremented register. */ | |
5880 | invalidate_mems_from_set (pbi, SET_DEST (x)); | |
5881 | ||
d7429b6a RK |
5882 | return 1; |
5883 | } | |
5884 | return 0; | |
5885 | } | |
5886 | ||
5887 | /* Try to change INSN so that it does pre-increment or pre-decrement | |
5888 | addressing on register REG in order to add AMOUNT to REG. | |
5889 | AMOUNT is negative for pre-decrement. | |
5890 | Returns 1 if the change could be made. | |
5891 | This checks all about the validity of the result of modifying INSN. */ | |
5892 | ||
5893 | static int | |
5894 | try_pre_increment (insn, reg, amount) | |
5895 | rtx insn, reg; | |
5f4f0e22 | 5896 | HOST_WIDE_INT amount; |
d7429b6a RK |
5897 | { |
5898 | register rtx use; | |
5899 | ||
5900 | /* Nonzero if we can try to make a pre-increment or pre-decrement. | |
5901 | For example, addl $4,r1; movl (r1),... can become movl +(r1),... */ | |
5902 | int pre_ok = 0; | |
5903 | /* Nonzero if we can try to make a post-increment or post-decrement. | |
5904 | For example, addl $4,r1; movl -4(r1),... can become movl (r1)+,... | |
5905 | It is possible for both PRE_OK and POST_OK to be nonzero if the machine | |
5906 | supports both pre-inc and post-inc, or both pre-dec and post-dec. */ | |
5907 | int post_ok = 0; | |
5908 | ||
5909 | /* Nonzero if the opportunity actually requires post-inc or post-dec. */ | |
5910 | int do_post = 0; | |
5911 | ||
5912 | /* From the sign of increment, see which possibilities are conceivable | |
5913 | on this target machine. */ | |
940da324 | 5914 | if (HAVE_PRE_INCREMENT && amount > 0) |
d7429b6a | 5915 | pre_ok = 1; |
940da324 | 5916 | if (HAVE_POST_INCREMENT && amount > 0) |
d7429b6a | 5917 | post_ok = 1; |
d7429b6a | 5918 | |
940da324 | 5919 | if (HAVE_PRE_DECREMENT && amount < 0) |
d7429b6a | 5920 | pre_ok = 1; |
940da324 | 5921 | if (HAVE_POST_DECREMENT && amount < 0) |
d7429b6a | 5922 | post_ok = 1; |
d7429b6a RK |
5923 | |
5924 | if (! (pre_ok || post_ok)) | |
5925 | return 0; | |
5926 | ||
5927 | /* It is not safe to add a side effect to a jump insn | |
5928 | because if the incremented register is spilled and must be reloaded | |
5929 | there would be no way to store the incremented value back in memory. */ | |
5930 | ||
5931 | if (GET_CODE (insn) == JUMP_INSN) | |
5932 | return 0; | |
5933 | ||
5934 | use = 0; | |
5935 | if (pre_ok) | |
5936 | use = find_use_as_address (PATTERN (insn), reg, 0); | |
5937 | if (post_ok && (use == 0 || use == (rtx) 1)) | |
5938 | { | |
5939 | use = find_use_as_address (PATTERN (insn), reg, -amount); | |
5940 | do_post = 1; | |
5941 | } | |
5942 | ||
5943 | if (use == 0 || use == (rtx) 1) | |
5944 | return 0; | |
5945 | ||
5946 | if (GET_MODE_SIZE (GET_MODE (use)) != (amount > 0 ? amount : - amount)) | |
5947 | return 0; | |
5948 | ||
a0fbc3a9 SC |
5949 | /* See if this combination of instruction and addressing mode exists. */ |
5950 | if (! validate_change (insn, &XEXP (use, 0), | |
38a448ca RH |
5951 | gen_rtx_fmt_e (amount > 0 |
5952 | ? (do_post ? POST_INC : PRE_INC) | |
5953 | : (do_post ? POST_DEC : PRE_DEC), | |
5954 | Pmode, reg), 0)) | |
a0fbc3a9 | 5955 | return 0; |
d7429b6a RK |
5956 | |
5957 | /* Record that this insn now has an implicit side effect on X. */ | |
d3a923ee | 5958 | REG_NOTES (insn) = alloc_EXPR_LIST (REG_INC, reg, REG_NOTES (insn)); |
d7429b6a RK |
5959 | return 1; |
5960 | } | |
5961 | ||
5962 | #endif /* AUTO_INC_DEC */ | |
5963 | \f | |
5964 | /* Find the place in the rtx X where REG is used as a memory address. | |
5965 | Return the MEM rtx that so uses it. | |
5966 | If PLUSCONST is nonzero, search instead for a memory address equivalent to | |
5967 | (plus REG (const_int PLUSCONST)). | |
5968 | ||
5969 | If such an address does not appear, return 0. | |
5970 | If REG appears more than once, or is used other than in such an address, | |
5971 | return (rtx)1. */ | |
5972 | ||
8c660648 | 5973 | rtx |
d7429b6a RK |
5974 | find_use_as_address (x, reg, plusconst) |
5975 | register rtx x; | |
5976 | rtx reg; | |
e658434c | 5977 | HOST_WIDE_INT plusconst; |
d7429b6a RK |
5978 | { |
5979 | enum rtx_code code = GET_CODE (x); | |
6f7d635c | 5980 | const char *fmt = GET_RTX_FORMAT (code); |
d7429b6a RK |
5981 | register int i; |
5982 | register rtx value = 0; | |
5983 | register rtx tem; | |
5984 | ||
5985 | if (code == MEM && XEXP (x, 0) == reg && plusconst == 0) | |
5986 | return x; | |
5987 | ||
5988 | if (code == MEM && GET_CODE (XEXP (x, 0)) == PLUS | |
5989 | && XEXP (XEXP (x, 0), 0) == reg | |
5990 | && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT | |
5991 | && INTVAL (XEXP (XEXP (x, 0), 1)) == plusconst) | |
5992 | return x; | |
5993 | ||
5994 | if (code == SIGN_EXTRACT || code == ZERO_EXTRACT) | |
5995 | { | |
5996 | /* If REG occurs inside a MEM used in a bit-field reference, | |
5997 | that is unacceptable. */ | |
5998 | if (find_use_as_address (XEXP (x, 0), reg, 0) != 0) | |
6fa5c106 | 5999 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
6000 | } |
6001 | ||
6002 | if (x == reg) | |
6fa5c106 | 6003 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
6004 | |
6005 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
6006 | { | |
6007 | if (fmt[i] == 'e') | |
6008 | { | |
6009 | tem = find_use_as_address (XEXP (x, i), reg, plusconst); | |
6010 | if (value == 0) | |
6011 | value = tem; | |
6012 | else if (tem != 0) | |
6fa5c106 | 6013 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a | 6014 | } |
d4757e6a | 6015 | else if (fmt[i] == 'E') |
d7429b6a RK |
6016 | { |
6017 | register int j; | |
6018 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
6019 | { | |
6020 | tem = find_use_as_address (XVECEXP (x, i, j), reg, plusconst); | |
6021 | if (value == 0) | |
6022 | value = tem; | |
6023 | else if (tem != 0) | |
6fa5c106 | 6024 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
6025 | } |
6026 | } | |
6027 | } | |
6028 | ||
6029 | return value; | |
6030 | } | |
6031 | \f | |
6032 | /* Write information about registers and basic blocks into FILE. | |
6033 | This is part of making a debugging dump. */ | |
6034 | ||
b7ba4d8d ZW |
6035 | void |
6036 | dump_regset (r, outf) | |
6037 | regset r; | |
6038 | FILE *outf; | |
6039 | { | |
6040 | int i; | |
6041 | if (r == NULL) | |
6042 | { | |
6043 | fputs (" (nil)", outf); | |
6044 | return; | |
6045 | } | |
6046 | ||
6047 | EXECUTE_IF_SET_IN_REG_SET (r, 0, i, | |
6048 | { | |
6049 | fprintf (outf, " %d", i); | |
6050 | if (i < FIRST_PSEUDO_REGISTER) | |
6051 | fprintf (outf, " [%s]", | |
6052 | reg_names[i]); | |
6053 | }); | |
6054 | } | |
6055 | ||
6056 | void | |
6057 | debug_regset (r) | |
6058 | regset r; | |
6059 | { | |
6060 | dump_regset (r, stderr); | |
6061 | putc ('\n', stderr); | |
6062 | } | |
6063 | ||
d7429b6a RK |
6064 | void |
6065 | dump_flow_info (file) | |
6066 | FILE *file; | |
6067 | { | |
6068 | register int i; | |
6f7d635c | 6069 | static const char * const reg_class_names[] = REG_CLASS_NAMES; |
d7429b6a RK |
6070 | |
6071 | fprintf (file, "%d registers.\n", max_regno); | |
d7429b6a | 6072 | for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) |
b1f21e0a | 6073 | if (REG_N_REFS (i)) |
d7429b6a | 6074 | { |
e4600702 | 6075 | enum reg_class class, altclass; |
d7429b6a | 6076 | fprintf (file, "\nRegister %d used %d times across %d insns", |
b1f21e0a MM |
6077 | i, REG_N_REFS (i), REG_LIVE_LENGTH (i)); |
6078 | if (REG_BASIC_BLOCK (i) >= 0) | |
6079 | fprintf (file, " in block %d", REG_BASIC_BLOCK (i)); | |
6fc4610b | 6080 | if (REG_N_SETS (i)) |
c9bacfdb KH |
6081 | fprintf (file, "; set %d time%s", REG_N_SETS (i), |
6082 | (REG_N_SETS (i) == 1) ? "" : "s"); | |
6fc4610b | 6083 | if (REG_USERVAR_P (regno_reg_rtx[i])) |
c9bacfdb | 6084 | fprintf (file, "; user var"); |
b1f21e0a MM |
6085 | if (REG_N_DEATHS (i) != 1) |
6086 | fprintf (file, "; dies in %d places", REG_N_DEATHS (i)); | |
6087 | if (REG_N_CALLS_CROSSED (i) == 1) | |
d7429b6a | 6088 | fprintf (file, "; crosses 1 call"); |
b1f21e0a MM |
6089 | else if (REG_N_CALLS_CROSSED (i)) |
6090 | fprintf (file, "; crosses %d calls", REG_N_CALLS_CROSSED (i)); | |
d7429b6a RK |
6091 | if (PSEUDO_REGNO_BYTES (i) != UNITS_PER_WORD) |
6092 | fprintf (file, "; %d bytes", PSEUDO_REGNO_BYTES (i)); | |
6093 | class = reg_preferred_class (i); | |
e4600702 RK |
6094 | altclass = reg_alternate_class (i); |
6095 | if (class != GENERAL_REGS || altclass != ALL_REGS) | |
d7429b6a | 6096 | { |
e4600702 RK |
6097 | if (altclass == ALL_REGS || class == ALL_REGS) |
6098 | fprintf (file, "; pref %s", reg_class_names[(int) class]); | |
6099 | else if (altclass == NO_REGS) | |
d7429b6a RK |
6100 | fprintf (file, "; %s or none", reg_class_names[(int) class]); |
6101 | else | |
e4600702 RK |
6102 | fprintf (file, "; pref %s, else %s", |
6103 | reg_class_names[(int) class], | |
6104 | reg_class_names[(int) altclass]); | |
d7429b6a | 6105 | } |
3502dc9c | 6106 | if (REG_POINTER (regno_reg_rtx[i])) |
d7429b6a RK |
6107 | fprintf (file, "; pointer"); |
6108 | fprintf (file, ".\n"); | |
6109 | } | |
e881bb1b | 6110 | |
d3a923ee | 6111 | fprintf (file, "\n%d basic blocks, %d edges.\n", n_basic_blocks, n_edges); |
e881bb1b RH |
6112 | for (i = 0; i < n_basic_blocks; i++) |
6113 | { | |
6114 | register basic_block bb = BASIC_BLOCK (i); | |
e881bb1b RH |
6115 | register edge e; |
6116 | ||
51891abe JH |
6117 | fprintf (file, "\nBasic block %d: first insn %d, last %d, loop_depth %d, count %d.\n", |
6118 | i, INSN_UID (bb->head), INSN_UID (bb->end), bb->loop_depth, bb->count); | |
e881bb1b RH |
6119 | |
6120 | fprintf (file, "Predecessors: "); | |
c9bacfdb | 6121 | for (e = bb->pred; e; e = e->pred_next) |
e881bb1b RH |
6122 | dump_edge_info (file, e, 0); |
6123 | ||
6124 | fprintf (file, "\nSuccessors: "); | |
c9bacfdb | 6125 | for (e = bb->succ; e; e = e->succ_next) |
e881bb1b RH |
6126 | dump_edge_info (file, e, 1); |
6127 | ||
6128 | fprintf (file, "\nRegisters live at start:"); | |
b7ba4d8d | 6129 | dump_regset (bb->global_live_at_start, file); |
e881bb1b RH |
6130 | |
6131 | fprintf (file, "\nRegisters live at end:"); | |
b7ba4d8d | 6132 | dump_regset (bb->global_live_at_end, file); |
e881bb1b | 6133 | |
c9bacfdb | 6134 | putc ('\n', file); |
e881bb1b RH |
6135 | } |
6136 | ||
c9bacfdb | 6137 | putc ('\n', file); |
e881bb1b RH |
6138 | } |
6139 | ||
93cba993 RH |
6140 | void |
6141 | debug_flow_info () | |
6142 | { | |
6143 | dump_flow_info (stderr); | |
6144 | } | |
6145 | ||
e881bb1b RH |
6146 | static void |
6147 | dump_edge_info (file, e, do_succ) | |
6148 | FILE *file; | |
6149 | edge e; | |
6150 | int do_succ; | |
6151 | { | |
6152 | basic_block side = (do_succ ? e->dest : e->src); | |
6153 | ||
6154 | if (side == ENTRY_BLOCK_PTR) | |
6155 | fputs (" ENTRY", file); | |
6156 | else if (side == EXIT_BLOCK_PTR) | |
6157 | fputs (" EXIT", file); | |
6158 | else | |
6159 | fprintf (file, " %d", side->index); | |
6160 | ||
51891abe JH |
6161 | if (e->count) |
6162 | fprintf (file, " count:%d", e->count); | |
6163 | ||
e881bb1b RH |
6164 | if (e->flags) |
6165 | { | |
6f7d635c | 6166 | static const char * const bitnames[] = { |
e881bb1b RH |
6167 | "fallthru", "crit", "ab", "abcall", "eh", "fake" |
6168 | }; | |
6169 | int comma = 0; | |
6170 | int i, flags = e->flags; | |
6171 | ||
6172 | fputc (' ', file); | |
6173 | fputc ('(', file); | |
6174 | for (i = 0; flags; i++) | |
6175 | if (flags & (1 << i)) | |
6176 | { | |
6177 | flags &= ~(1 << i); | |
6178 | ||
6179 | if (comma) | |
6180 | fputc (',', file); | |
9a56f4f6 | 6181 | if (i < (int) ARRAY_SIZE (bitnames)) |
e881bb1b RH |
6182 | fputs (bitnames[i], file); |
6183 | else | |
6184 | fprintf (file, "%d", i); | |
6185 | comma = 1; | |
6186 | } | |
6187 | fputc (')', file); | |
6188 | } | |
d7429b6a | 6189 | } |
3e28fe44 | 6190 | \f |
b7ba4d8d | 6191 | /* Print out one basic block with live information at start and end. */ |
c9bacfdb | 6192 | |
b7ba4d8d ZW |
6193 | void |
6194 | dump_bb (bb, outf) | |
6195 | basic_block bb; | |
6196 | FILE *outf; | |
6197 | { | |
6198 | rtx insn; | |
6199 | rtx last; | |
6200 | edge e; | |
6201 | ||
51891abe JH |
6202 | fprintf (outf, ";; Basic block %d, loop depth %d, count %d", |
6203 | bb->index, bb->loop_depth, bb->count); | |
b7ba4d8d ZW |
6204 | if (bb->eh_beg != -1 || bb->eh_end != -1) |
6205 | fprintf (outf, ", eh regions %d/%d", bb->eh_beg, bb->eh_end); | |
6206 | putc ('\n', outf); | |
6207 | ||
6208 | fputs (";; Predecessors: ", outf); | |
c9bacfdb | 6209 | for (e = bb->pred; e; e = e->pred_next) |
b7ba4d8d ZW |
6210 | dump_edge_info (outf, e, 0); |
6211 | putc ('\n', outf); | |
6212 | ||
6213 | fputs (";; Registers live at start:", outf); | |
6214 | dump_regset (bb->global_live_at_start, outf); | |
6215 | putc ('\n', outf); | |
6216 | ||
6217 | for (insn = bb->head, last = NEXT_INSN (bb->end); | |
6218 | insn != last; | |
6219 | insn = NEXT_INSN (insn)) | |
6220 | print_rtl_single (outf, insn); | |
6221 | ||
6222 | fputs (";; Registers live at end:", outf); | |
6223 | dump_regset (bb->global_live_at_end, outf); | |
6224 | putc ('\n', outf); | |
6225 | ||
6226 | fputs (";; Successors: ", outf); | |
6227 | for (e = bb->succ; e; e = e->succ_next) | |
6228 | dump_edge_info (outf, e, 1); | |
6229 | putc ('\n', outf); | |
6230 | } | |
6231 | ||
6232 | void | |
6233 | debug_bb (bb) | |
6234 | basic_block bb; | |
6235 | { | |
6236 | dump_bb (bb, stderr); | |
6237 | } | |
6238 | ||
6239 | void | |
6240 | debug_bb_n (n) | |
6241 | int n; | |
6242 | { | |
c9bacfdb | 6243 | dump_bb (BASIC_BLOCK (n), stderr); |
b7ba4d8d ZW |
6244 | } |
6245 | ||
3e28fe44 MM |
6246 | /* Like print_rtl, but also print out live information for the start of each |
6247 | basic block. */ | |
6248 | ||
6249 | void | |
6250 | print_rtl_with_bb (outf, rtx_first) | |
6251 | FILE *outf; | |
6252 | rtx rtx_first; | |
6253 | { | |
6254 | register rtx tmp_rtx; | |
6255 | ||
6256 | if (rtx_first == 0) | |
6257 | fprintf (outf, "(nil)\n"); | |
3e28fe44 MM |
6258 | else |
6259 | { | |
e881bb1b | 6260 | int i; |
3e28fe44 MM |
6261 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
6262 | int max_uid = get_max_uid (); | |
54ea1de9 | 6263 | basic_block *start = (basic_block *) |
67289ea6 | 6264 | xcalloc (max_uid, sizeof (basic_block)); |
54ea1de9 | 6265 | basic_block *end = (basic_block *) |
67289ea6 | 6266 | xcalloc (max_uid, sizeof (basic_block)); |
2a92c071 | 6267 | enum bb_state *in_bb_p = (enum bb_state *) |
67289ea6 | 6268 | xcalloc (max_uid, sizeof (enum bb_state)); |
3e28fe44 | 6269 | |
e881bb1b | 6270 | for (i = n_basic_blocks - 1; i >= 0; i--) |
3e28fe44 | 6271 | { |
e881bb1b | 6272 | basic_block bb = BASIC_BLOCK (i); |
3e28fe44 | 6273 | rtx x; |
e881bb1b RH |
6274 | |
6275 | start[INSN_UID (bb->head)] = bb; | |
6276 | end[INSN_UID (bb->end)] = bb; | |
6277 | for (x = bb->head; x != NULL_RTX; x = NEXT_INSN (x)) | |
3e28fe44 | 6278 | { |
e881bb1b | 6279 | enum bb_state state = IN_MULTIPLE_BB; |
c9bacfdb | 6280 | if (in_bb_p[INSN_UID (x)] == NOT_IN_BB) |
e881bb1b | 6281 | state = IN_ONE_BB; |
c9bacfdb | 6282 | in_bb_p[INSN_UID (x)] = state; |
e881bb1b RH |
6283 | |
6284 | if (x == bb->end) | |
3e28fe44 MM |
6285 | break; |
6286 | } | |
6287 | } | |
6288 | ||
6289 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
6290 | { | |
b707b450 | 6291 | int did_output; |
e881bb1b | 6292 | basic_block bb; |
b707b450 | 6293 | |
e881bb1b | 6294 | if ((bb = start[INSN_UID (tmp_rtx)]) != NULL) |
3e28fe44 MM |
6295 | { |
6296 | fprintf (outf, ";; Start of basic block %d, registers live:", | |
e881bb1b | 6297 | bb->index); |
b7ba4d8d | 6298 | dump_regset (bb->global_live_at_start, outf); |
3e28fe44 MM |
6299 | putc ('\n', outf); |
6300 | } | |
6301 | ||
c9bacfdb | 6302 | if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB |
3e28fe44 | 6303 | && GET_CODE (tmp_rtx) != NOTE |
d29c259b | 6304 | && GET_CODE (tmp_rtx) != BARRIER) |
3e28fe44 | 6305 | fprintf (outf, ";; Insn is not within a basic block\n"); |
c9bacfdb | 6306 | else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB) |
3e28fe44 MM |
6307 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); |
6308 | ||
b707b450 | 6309 | did_output = print_rtl_single (outf, tmp_rtx); |
3e28fe44 | 6310 | |
e881bb1b | 6311 | if ((bb = end[INSN_UID (tmp_rtx)]) != NULL) |
62828c00 RH |
6312 | { |
6313 | fprintf (outf, ";; End of basic block %d, registers live:\n", | |
6314 | bb->index); | |
6315 | dump_regset (bb->global_live_at_end, outf); | |
6316 | putc ('\n', outf); | |
6317 | } | |
3e28fe44 | 6318 | |
b707b450 | 6319 | if (did_output) |
9ec36da5 | 6320 | putc ('\n', outf); |
3e28fe44 | 6321 | } |
67289ea6 MM |
6322 | |
6323 | free (start); | |
6324 | free (end); | |
6325 | free (in_bb_p); | |
3e28fe44 | 6326 | } |
c5c76735 JL |
6327 | |
6328 | if (current_function_epilogue_delay_list != 0) | |
6329 | { | |
6330 | fprintf (outf, "\n;; Insns in epilogue delay list:\n\n"); | |
6331 | for (tmp_rtx = current_function_epilogue_delay_list; tmp_rtx != 0; | |
6332 | tmp_rtx = XEXP (tmp_rtx, 1)) | |
6333 | print_rtl_single (outf, XEXP (tmp_rtx, 0)); | |
6334 | } | |
3e28fe44 | 6335 | } |
5ece9746 | 6336 | |
f9b697bf BS |
6337 | /* Dump the rtl into the current debugging dump file, then abort. */ |
6338 | static void | |
c3ff75c4 | 6339 | print_rtl_and_abort () |
f9b697bf BS |
6340 | { |
6341 | if (rtl_dump_file) | |
6342 | { | |
6343 | print_rtl_with_bb (rtl_dump_file, get_insns ()); | |
6344 | fclose (rtl_dump_file); | |
6345 | } | |
6346 | abort (); | |
6347 | } | |
6348 | ||
4c649323 JL |
6349 | /* Recompute register set/reference counts immediately prior to register |
6350 | allocation. | |
6351 | ||
6352 | This avoids problems with set/reference counts changing to/from values | |
6353 | which have special meanings to the register allocators. | |
6354 | ||
6355 | Additionally, the reference counts are the primary component used by the | |
6356 | register allocators to prioritize pseudos for allocation to hard regs. | |
6357 | More accurate reference counts generally lead to better register allocation. | |
6358 | ||
213c4983 | 6359 | F is the first insn to be scanned. |
9b15c17f | 6360 | |
213c4983 | 6361 | LOOP_STEP denotes how much loop_depth should be incremented per |
9b15c17f RH |
6362 | loop nesting level in order to increase the ref count more for |
6363 | references in a loop. | |
213c4983 | 6364 | |
4c649323 JL |
6365 | It might be worthwhile to update REG_LIVE_LENGTH, REG_BASIC_BLOCK and |
6366 | possibly other information which is used by the register allocators. */ | |
6367 | ||
762a1d90 | 6368 | void |
213c4983 | 6369 | recompute_reg_usage (f, loop_step) |
272df862 KG |
6370 | rtx f ATTRIBUTE_UNUSED; |
6371 | int loop_step ATTRIBUTE_UNUSED; | |
4c649323 | 6372 | { |
f134997f RH |
6373 | allocate_reg_life_data (); |
6374 | update_life_info (NULL, UPDATE_LIFE_LOCAL, PROP_REG_INFO); | |
4c649323 | 6375 | } |
e881bb1b | 6376 | |
d3a923ee | 6377 | /* Optionally removes all the REG_DEAD and REG_UNUSED notes from a set of |
3071fab5 RH |
6378 | blocks. If BLOCKS is NULL, assume the universal set. Returns a count |
6379 | of the number of registers that died. */ | |
d3a923ee RH |
6380 | |
6381 | int | |
6382 | count_or_remove_death_notes (blocks, kill) | |
c9bacfdb KH |
6383 | sbitmap blocks; |
6384 | int kill; | |
d3a923ee RH |
6385 | { |
6386 | int i, count = 0; | |
6387 | ||
6388 | for (i = n_basic_blocks - 1; i >= 0; --i) | |
6389 | { | |
6390 | basic_block bb; | |
6391 | rtx insn; | |
6392 | ||
3071fab5 | 6393 | if (blocks && ! TEST_BIT (blocks, i)) |
d3a923ee RH |
6394 | continue; |
6395 | ||
6396 | bb = BASIC_BLOCK (i); | |
6397 | ||
c9bacfdb | 6398 | for (insn = bb->head;; insn = NEXT_INSN (insn)) |
d3a923ee | 6399 | { |
2c3c49de | 6400 | if (INSN_P (insn)) |
d3a923ee RH |
6401 | { |
6402 | rtx *pprev = ®_NOTES (insn); | |
6403 | rtx link = *pprev; | |
6404 | ||
6405 | while (link) | |
6406 | { | |
6407 | switch (REG_NOTE_KIND (link)) | |
6408 | { | |
6409 | case REG_DEAD: | |
6410 | if (GET_CODE (XEXP (link, 0)) == REG) | |
6411 | { | |
6412 | rtx reg = XEXP (link, 0); | |
6413 | int n; | |
6414 | ||
6415 | if (REGNO (reg) >= FIRST_PSEUDO_REGISTER) | |
6416 | n = 1; | |
6417 | else | |
6418 | n = HARD_REGNO_NREGS (REGNO (reg), GET_MODE (reg)); | |
6419 | count += n; | |
6420 | } | |
c9bacfdb | 6421 | /* Fall through. */ |
d3a923ee RH |
6422 | |
6423 | case REG_UNUSED: | |
6424 | if (kill) | |
6425 | { | |
6426 | rtx next = XEXP (link, 1); | |
6427 | free_EXPR_LIST_node (link); | |
c9bacfdb KH |
6428 | *pprev = link = next; |
6429 | break; | |
d3a923ee | 6430 | } |
c9bacfdb | 6431 | /* Fall through. */ |
d3a923ee RH |
6432 | |
6433 | default: | |
6434 | pprev = &XEXP (link, 1); | |
6435 | link = *pprev; | |
6436 | break; | |
6437 | } | |
6438 | } | |
6439 | } | |
6440 | ||
6441 | if (insn == bb->end) | |
6442 | break; | |
6443 | } | |
6444 | } | |
6445 | ||
6446 | return count; | |
6447 | } | |
6448 | ||
c586192c MH |
6449 | |
6450 | /* Update insns block within BB. */ | |
6451 | ||
6452 | void | |
6453 | update_bb_for_insn (bb) | |
6454 | basic_block bb; | |
6455 | { | |
6456 | rtx insn; | |
6457 | ||
6458 | if (! basic_block_for_insn) | |
6459 | return; | |
6460 | ||
6461 | for (insn = bb->head; ; insn = NEXT_INSN (insn)) | |
6462 | { | |
6463 | set_block_for_insn (insn, bb); | |
6464 | ||
6465 | if (insn == bb->end) | |
6466 | break; | |
6467 | } | |
6468 | } | |
6469 | ||
6470 | ||
e881bb1b RH |
6471 | /* Record INSN's block as BB. */ |
6472 | ||
6473 | void | |
6474 | set_block_for_insn (insn, bb) | |
6475 | rtx insn; | |
6476 | basic_block bb; | |
6477 | { | |
6478 | size_t uid = INSN_UID (insn); | |
6479 | if (uid >= basic_block_for_insn->num_elements) | |
6480 | { | |
6481 | int new_size; | |
c9bacfdb | 6482 | |
e881bb1b RH |
6483 | /* Add one-eighth the size so we don't keep calling xrealloc. */ |
6484 | new_size = uid + (uid + 7) / 8; | |
6485 | ||
6486 | VARRAY_GROW (basic_block_for_insn, new_size); | |
6487 | } | |
6488 | VARRAY_BB (basic_block_for_insn, uid) = bb; | |
6489 | } | |
6490 | ||
6491 | /* Record INSN's block number as BB. */ | |
6492 | /* ??? This has got to go. */ | |
6493 | ||
6494 | void | |
6495 | set_block_num (insn, bb) | |
6496 | rtx insn; | |
6497 | int bb; | |
6498 | { | |
6499 | set_block_for_insn (insn, BASIC_BLOCK (bb)); | |
6500 | } | |
34487bf8 | 6501 | \f |
d3a923ee RH |
6502 | /* Verify the CFG consistency. This function check some CFG invariants and |
6503 | aborts when something is wrong. Hope that this function will help to | |
6504 | convert many optimization passes to preserve CFG consistent. | |
f2a1bc02 | 6505 | |
c9bacfdb | 6506 | Currently it does following checks: |
f2a1bc02 | 6507 | |
d3a923ee RH |
6508 | - test head/end pointers |
6509 | - overlapping of basic blocks | |
6510 | - edge list corectness | |
6511 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) | |
6512 | - tails of basic blocks (ensure that boundary is necesary) | |
6513 | - scans body of the basic block for JUMP_INSN, CODE_LABEL | |
6514 | and NOTE_INSN_BASIC_BLOCK | |
c9bacfdb | 6515 | - check that all insns are in the basic blocks |
d3a923ee | 6516 | (except the switch handling code, barriers and notes) |
0edd203b | 6517 | - check that all returns are followed by barriers |
f2a1bc02 | 6518 | |
d3a923ee RH |
6519 | In future it can be extended check a lot of other stuff as well |
6520 | (reachability of basic blocks, life information, etc. etc.). */ | |
f2a1bc02 | 6521 | |
d3a923ee RH |
6522 | void |
6523 | verify_flow_info () | |
f2a1bc02 | 6524 | { |
d3a923ee RH |
6525 | const int max_uid = get_max_uid (); |
6526 | const rtx rtx_first = get_insns (); | |
6ff71a97 | 6527 | rtx last_head = get_last_insn (); |
d3a923ee RH |
6528 | basic_block *bb_info; |
6529 | rtx x; | |
18ca529b | 6530 | int i, last_bb_num_seen, num_bb_notes, err = 0; |
f2a1bc02 | 6531 | |
67289ea6 | 6532 | bb_info = (basic_block *) xcalloc (max_uid, sizeof (basic_block)); |
f2a1bc02 | 6533 | |
d3a923ee | 6534 | for (i = n_basic_blocks - 1; i >= 0; i--) |
f2a1bc02 | 6535 | { |
d3a923ee | 6536 | basic_block bb = BASIC_BLOCK (i); |
6ff71a97 JL |
6537 | rtx head = bb->head; |
6538 | rtx end = bb->end; | |
f2a1bc02 | 6539 | |
6ff71a97 JL |
6540 | /* Verify the end of the basic block is in the INSN chain. */ |
6541 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) | |
6542 | if (x == end) | |
d3a923ee RH |
6543 | break; |
6544 | if (!x) | |
6545 | { | |
6ff71a97 JL |
6546 | error ("End insn %d for block %d not found in the insn stream.", |
6547 | INSN_UID (end), bb->index); | |
d3a923ee RH |
6548 | err = 1; |
6549 | } | |
f2a1bc02 | 6550 | |
6ff71a97 JL |
6551 | /* Work backwards from the end to the head of the basic block |
6552 | to verify the head is in the RTL chain. */ | |
c9bacfdb | 6553 | for (; x != NULL_RTX; x = PREV_INSN (x)) |
f2a1bc02 | 6554 | { |
6ff71a97 JL |
6555 | /* While walking over the insn chain, verify insns appear |
6556 | in only one basic block and initialize the BB_INFO array | |
6557 | used by other passes. */ | |
d3a923ee | 6558 | if (bb_info[INSN_UID (x)] != NULL) |
f2a1bc02 | 6559 | { |
d3a923ee RH |
6560 | error ("Insn %d is in multiple basic blocks (%d and %d)", |
6561 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); | |
6562 | err = 1; | |
f2a1bc02 | 6563 | } |
d3a923ee RH |
6564 | bb_info[INSN_UID (x)] = bb; |
6565 | ||
6ff71a97 | 6566 | if (x == head) |
f2a1bc02 BM |
6567 | break; |
6568 | } | |
d3a923ee RH |
6569 | if (!x) |
6570 | { | |
6ff71a97 JL |
6571 | error ("Head insn %d for block %d not found in the insn stream.", |
6572 | INSN_UID (head), bb->index); | |
d3a923ee RH |
6573 | err = 1; |
6574 | } | |
6ff71a97 JL |
6575 | |
6576 | last_head = x; | |
f2a1bc02 | 6577 | } |
f2a1bc02 | 6578 | |
d3a923ee RH |
6579 | /* Now check the basic blocks (boundaries etc.) */ |
6580 | for (i = n_basic_blocks - 1; i >= 0; i--) | |
f2a1bc02 | 6581 | { |
d3a923ee RH |
6582 | basic_block bb = BASIC_BLOCK (i); |
6583 | /* Check corectness of edge lists */ | |
6584 | edge e; | |
f2a1bc02 | 6585 | |
d3a923ee RH |
6586 | e = bb->succ; |
6587 | while (e) | |
f2a1bc02 | 6588 | { |
d3a923ee | 6589 | if (e->src != bb) |
f2a1bc02 | 6590 | { |
c9bacfdb KH |
6591 | fprintf (stderr, |
6592 | "verify_flow_info: Basic block %d succ edge is corrupted\n", | |
d3a923ee RH |
6593 | bb->index); |
6594 | fprintf (stderr, "Predecessor: "); | |
6595 | dump_edge_info (stderr, e, 0); | |
6596 | fprintf (stderr, "\nSuccessor: "); | |
6597 | dump_edge_info (stderr, e, 1); | |
6598 | fflush (stderr); | |
6599 | err = 1; | |
f2a1bc02 | 6600 | } |
d3a923ee | 6601 | if (e->dest != EXIT_BLOCK_PTR) |
f2a1bc02 | 6602 | { |
d3a923ee RH |
6603 | edge e2 = e->dest->pred; |
6604 | while (e2 && e2 != e) | |
6605 | e2 = e2->pred_next; | |
6606 | if (!e2) | |
6607 | { | |
6608 | error ("Basic block %i edge lists are corrupted", bb->index); | |
6609 | err = 1; | |
6610 | } | |
f2a1bc02 | 6611 | } |
d3a923ee | 6612 | e = e->succ_next; |
f2a1bc02 | 6613 | } |
f2a1bc02 | 6614 | |
d3a923ee RH |
6615 | e = bb->pred; |
6616 | while (e) | |
f2a1bc02 | 6617 | { |
d3a923ee | 6618 | if (e->dest != bb) |
f2a1bc02 | 6619 | { |
d3a923ee RH |
6620 | error ("Basic block %d pred edge is corrupted", bb->index); |
6621 | fputs ("Predecessor: ", stderr); | |
6622 | dump_edge_info (stderr, e, 0); | |
6623 | fputs ("\nSuccessor: ", stderr); | |
6624 | dump_edge_info (stderr, e, 1); | |
6625 | fputc ('\n', stderr); | |
6626 | err = 1; | |
34487bf8 RH |
6627 | } |
6628 | if (e->src != ENTRY_BLOCK_PTR) | |
6629 | { | |
6630 | edge e2 = e->src->succ; | |
6631 | while (e2 && e2 != e) | |
6632 | e2 = e2->succ_next; | |
6633 | if (!e2) | |
6634 | { | |
987009bf | 6635 | error ("Basic block %i edge lists are corrupted", bb->index); |
d3a923ee | 6636 | err = 1; |
34487bf8 RH |
6637 | } |
6638 | } | |
6639 | e = e->pred_next; | |
6640 | } | |
6641 | ||
6642 | /* OK pointers are correct. Now check the header of basic | |
6643 | block. It ought to contain optional CODE_LABEL followed | |
6644 | by NOTE_BASIC_BLOCK. */ | |
6645 | x = bb->head; | |
6646 | if (GET_CODE (x) == CODE_LABEL) | |
6647 | { | |
6648 | if (bb->end == x) | |
6649 | { | |
987009bf ZW |
6650 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", |
6651 | bb->index); | |
d3a923ee | 6652 | err = 1; |
34487bf8 RH |
6653 | } |
6654 | x = NEXT_INSN (x); | |
6655 | } | |
589ca5cb | 6656 | if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb) |
34487bf8 | 6657 | { |
987009bf | 6658 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d\n", |
34487bf8 | 6659 | bb->index); |
d3a923ee | 6660 | err = 1; |
34487bf8 RH |
6661 | } |
6662 | ||
6663 | if (bb->end == x) | |
6664 | { | |
6665 | /* Do checks for empty blocks here */ | |
6666 | } | |
6667 | else | |
6668 | { | |
6669 | x = NEXT_INSN (x); | |
6670 | while (x) | |
6671 | { | |
589ca5cb | 6672 | if (NOTE_INSN_BASIC_BLOCK_P (x)) |
34487bf8 | 6673 | { |
987009bf | 6674 | error ("NOTE_INSN_BASIC_BLOCK %d in the middle of basic block %d", |
34487bf8 | 6675 | INSN_UID (x), bb->index); |
d3a923ee | 6676 | err = 1; |
34487bf8 RH |
6677 | } |
6678 | ||
6679 | if (x == bb->end) | |
6680 | break; | |
6681 | ||
6682 | if (GET_CODE (x) == JUMP_INSN | |
6683 | || GET_CODE (x) == CODE_LABEL | |
6684 | || GET_CODE (x) == BARRIER) | |
6685 | { | |
987009bf ZW |
6686 | error ("In basic block %d:", bb->index); |
6687 | fatal_insn ("Flow control insn inside a basic block", x); | |
34487bf8 RH |
6688 | } |
6689 | ||
6690 | x = NEXT_INSN (x); | |
6691 | } | |
6692 | } | |
6693 | } | |
6694 | ||
18ca529b JE |
6695 | last_bb_num_seen = -1; |
6696 | num_bb_notes = 0; | |
34487bf8 RH |
6697 | x = rtx_first; |
6698 | while (x) | |
6699 | { | |
589ca5cb | 6700 | if (NOTE_INSN_BASIC_BLOCK_P (x)) |
18ca529b JE |
6701 | { |
6702 | basic_block bb = NOTE_BASIC_BLOCK (x); | |
6703 | num_bb_notes++; | |
6704 | if (bb->index != last_bb_num_seen + 1) | |
6705 | fatal ("Basic blocks not numbered consecutively"); | |
6706 | last_bb_num_seen = bb->index; | |
6707 | } | |
6708 | ||
34487bf8 RH |
6709 | if (!bb_info[INSN_UID (x)]) |
6710 | { | |
6711 | switch (GET_CODE (x)) | |
6712 | { | |
6713 | case BARRIER: | |
6714 | case NOTE: | |
6715 | break; | |
6716 | ||
6717 | case CODE_LABEL: | |
6718 | /* An addr_vec is placed outside any block block. */ | |
6719 | if (NEXT_INSN (x) | |
6720 | && GET_CODE (NEXT_INSN (x)) == JUMP_INSN | |
6721 | && (GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_DIFF_VEC | |
6722 | || GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_VEC)) | |
6723 | { | |
6724 | x = NEXT_INSN (x); | |
6725 | } | |
6726 | ||
6727 | /* But in any case, non-deletable labels can appear anywhere. */ | |
6728 | break; | |
6729 | ||
6730 | default: | |
987009bf | 6731 | fatal_insn ("Insn outside basic block", x); |
34487bf8 RH |
6732 | } |
6733 | } | |
6734 | ||
2c3c49de | 6735 | if (INSN_P (x) |
0edd203b | 6736 | && GET_CODE (x) == JUMP_INSN |
2ca19d5e | 6737 | && returnjump_p (x) && ! condjump_p (x) |
0edd203b JE |
6738 | && ! (NEXT_INSN (x) && GET_CODE (NEXT_INSN (x)) == BARRIER)) |
6739 | fatal_insn ("Return not followed by barrier", x); | |
6740 | ||
34487bf8 RH |
6741 | x = NEXT_INSN (x); |
6742 | } | |
d3a923ee | 6743 | |
18ca529b JE |
6744 | if (num_bb_notes != n_basic_blocks) |
6745 | fatal ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)", | |
6746 | num_bb_notes, n_basic_blocks); | |
6747 | ||
d3a923ee RH |
6748 | if (err) |
6749 | abort (); | |
67289ea6 MM |
6750 | |
6751 | /* Clean up. */ | |
6752 | free (bb_info); | |
34487bf8 | 6753 | } |
410538ea AM |
6754 | \f |
6755 | /* Functions to access an edge list with a vector representation. | |
c9bacfdb | 6756 | Enough data is kept such that given an index number, the |
4eb00163 JO |
6757 | pred and succ that edge represents can be determined, or |
6758 | given a pred and a succ, its index number can be returned. | |
c9bacfdb | 6759 | This allows algorithms which consume a lot of memory to |
410538ea AM |
6760 | represent the normally full matrix of edge (pred,succ) with a |
6761 | single indexed vector, edge (EDGE_INDEX (pred, succ)), with no | |
6762 | wasted space in the client code due to sparse flow graphs. */ | |
6763 | ||
c9bacfdb | 6764 | /* This functions initializes the edge list. Basically the entire |
410538ea | 6765 | flowgraph is processed, and all edges are assigned a number, |
4eb00163 | 6766 | and the data structure is filled in. */ |
c9bacfdb | 6767 | |
410538ea AM |
6768 | struct edge_list * |
6769 | create_edge_list () | |
6770 | { | |
6771 | struct edge_list *elist; | |
6772 | edge e; | |
6773 | int num_edges; | |
e2bef702 | 6774 | int x; |
410538ea AM |
6775 | int block_count; |
6776 | ||
6777 | block_count = n_basic_blocks + 2; /* Include the entry and exit blocks. */ | |
6778 | ||
6779 | num_edges = 0; | |
6780 | ||
6781 | /* Determine the number of edges in the flow graph by counting successor | |
6782 | edges on each basic block. */ | |
6783 | for (x = 0; x < n_basic_blocks; x++) | |
6784 | { | |
6785 | basic_block bb = BASIC_BLOCK (x); | |
6786 | ||
6787 | for (e = bb->succ; e; e = e->succ_next) | |
6788 | num_edges++; | |
6789 | } | |
6790 | /* Don't forget successors of the entry block. */ | |
6791 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) | |
6792 | num_edges++; | |
6793 | ||
2c852885 | 6794 | elist = (struct edge_list *) xmalloc (sizeof (struct edge_list)); |
410538ea AM |
6795 | elist->num_blocks = block_count; |
6796 | elist->num_edges = num_edges; | |
2c852885 | 6797 | elist->index_to_edge = (edge *) xmalloc (sizeof (edge) * num_edges); |
410538ea AM |
6798 | |
6799 | num_edges = 0; | |
6800 | ||
6801 | /* Follow successors of the entry block, and register these edges. */ | |
6802 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) | |
6803 | { | |
6804 | elist->index_to_edge[num_edges] = e; | |
6805 | num_edges++; | |
6806 | } | |
c9bacfdb | 6807 | |
410538ea AM |
6808 | for (x = 0; x < n_basic_blocks; x++) |
6809 | { | |
6810 | basic_block bb = BASIC_BLOCK (x); | |
6811 | ||
6812 | /* Follow all successors of blocks, and register these edges. */ | |
6813 | for (e = bb->succ; e; e = e->succ_next) | |
6814 | { | |
6815 | elist->index_to_edge[num_edges] = e; | |
6816 | num_edges++; | |
6817 | } | |
6818 | } | |
6819 | return elist; | |
6820 | } | |
6821 | ||
6822 | /* This function free's memory associated with an edge list. */ | |
c9bacfdb | 6823 | |
410538ea AM |
6824 | void |
6825 | free_edge_list (elist) | |
6826 | struct edge_list *elist; | |
6827 | { | |
6828 | if (elist) | |
6829 | { | |
6830 | free (elist->index_to_edge); | |
6831 | free (elist); | |
6832 | } | |
6833 | } | |
6834 | ||
6835 | /* This function provides debug output showing an edge list. */ | |
c9bacfdb KH |
6836 | |
6837 | void | |
410538ea AM |
6838 | print_edge_list (f, elist) |
6839 | FILE *f; | |
6840 | struct edge_list *elist; | |
6841 | { | |
6842 | int x; | |
c9bacfdb KH |
6843 | fprintf (f, "Compressed edge list, %d BBs + entry & exit, and %d edges\n", |
6844 | elist->num_blocks - 2, elist->num_edges); | |
410538ea AM |
6845 | |
6846 | for (x = 0; x < elist->num_edges; x++) | |
6847 | { | |
6848 | fprintf (f, " %-4d - edge(", x); | |
6849 | if (INDEX_EDGE_PRED_BB (elist, x) == ENTRY_BLOCK_PTR) | |
c9bacfdb | 6850 | fprintf (f, "entry,"); |
410538ea | 6851 | else |
c9bacfdb | 6852 | fprintf (f, "%d,", INDEX_EDGE_PRED_BB (elist, x)->index); |
410538ea AM |
6853 | |
6854 | if (INDEX_EDGE_SUCC_BB (elist, x) == EXIT_BLOCK_PTR) | |
c9bacfdb | 6855 | fprintf (f, "exit)\n"); |
410538ea | 6856 | else |
c9bacfdb | 6857 | fprintf (f, "%d)\n", INDEX_EDGE_SUCC_BB (elist, x)->index); |
410538ea AM |
6858 | } |
6859 | } | |
6860 | ||
4eb00163 | 6861 | /* This function provides an internal consistency check of an edge list, |
c9bacfdb | 6862 | verifying that all edges are present, and that there are no |
410538ea | 6863 | extra edges. */ |
c9bacfdb | 6864 | |
410538ea AM |
6865 | void |
6866 | verify_edge_list (f, elist) | |
6867 | FILE *f; | |
6868 | struct edge_list *elist; | |
6869 | { | |
6870 | int x, pred, succ, index; | |
410538ea AM |
6871 | edge e; |
6872 | ||
6873 | for (x = 0; x < n_basic_blocks; x++) | |
6874 | { | |
6875 | basic_block bb = BASIC_BLOCK (x); | |
6876 | ||
6877 | for (e = bb->succ; e; e = e->succ_next) | |
6878 | { | |
6879 | pred = e->src->index; | |
6880 | succ = e->dest->index; | |
d675a426 | 6881 | index = EDGE_INDEX (elist, e->src, e->dest); |
410538ea AM |
6882 | if (index == EDGE_INDEX_NO_EDGE) |
6883 | { | |
c9bacfdb | 6884 | fprintf (f, "*p* No index for edge from %d to %d\n", pred, succ); |
410538ea AM |
6885 | continue; |
6886 | } | |
6887 | if (INDEX_EDGE_PRED_BB (elist, index)->index != pred) | |
6888 | fprintf (f, "*p* Pred for index %d should be %d not %d\n", | |
6889 | index, pred, INDEX_EDGE_PRED_BB (elist, index)->index); | |
6890 | if (INDEX_EDGE_SUCC_BB (elist, index)->index != succ) | |
6891 | fprintf (f, "*p* Succ for index %d should be %d not %d\n", | |
6892 | index, succ, INDEX_EDGE_SUCC_BB (elist, index)->index); | |
6893 | } | |
6894 | } | |
6895 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) | |
6896 | { | |
6897 | pred = e->src->index; | |
6898 | succ = e->dest->index; | |
d675a426 | 6899 | index = EDGE_INDEX (elist, e->src, e->dest); |
410538ea AM |
6900 | if (index == EDGE_INDEX_NO_EDGE) |
6901 | { | |
c9bacfdb | 6902 | fprintf (f, "*p* No index for edge from %d to %d\n", pred, succ); |
410538ea AM |
6903 | continue; |
6904 | } | |
6905 | if (INDEX_EDGE_PRED_BB (elist, index)->index != pred) | |
6906 | fprintf (f, "*p* Pred for index %d should be %d not %d\n", | |
6907 | index, pred, INDEX_EDGE_PRED_BB (elist, index)->index); | |
6908 | if (INDEX_EDGE_SUCC_BB (elist, index)->index != succ) | |
6909 | fprintf (f, "*p* Succ for index %d should be %d not %d\n", | |
6910 | index, succ, INDEX_EDGE_SUCC_BB (elist, index)->index); | |
6911 | } | |
6912 | /* We've verified that all the edges are in the list, no lets make sure | |
6913 | there are no spurious edges in the list. */ | |
c9bacfdb KH |
6914 | |
6915 | for (pred = 0; pred < n_basic_blocks; pred++) | |
6916 | for (succ = 0; succ < n_basic_blocks; succ++) | |
410538ea | 6917 | { |
c9bacfdb KH |
6918 | basic_block p = BASIC_BLOCK (pred); |
6919 | basic_block s = BASIC_BLOCK (succ); | |
410538ea | 6920 | |
c9bacfdb | 6921 | int found_edge = 0; |
410538ea | 6922 | |
c9bacfdb KH |
6923 | for (e = p->succ; e; e = e->succ_next) |
6924 | if (e->dest == s) | |
410538ea AM |
6925 | { |
6926 | found_edge = 1; | |
6927 | break; | |
6928 | } | |
c9bacfdb KH |
6929 | for (e = s->pred; e; e = e->pred_next) |
6930 | if (e->src == p) | |
410538ea AM |
6931 | { |
6932 | found_edge = 1; | |
6933 | break; | |
6934 | } | |
c9bacfdb | 6935 | if (EDGE_INDEX (elist, BASIC_BLOCK (pred), BASIC_BLOCK (succ)) |
d675a426 | 6936 | == EDGE_INDEX_NO_EDGE && found_edge != 0) |
410538ea | 6937 | fprintf (f, "*** Edge (%d, %d) appears to not have an index\n", |
c9bacfdb KH |
6938 | pred, succ); |
6939 | if (EDGE_INDEX (elist, BASIC_BLOCK (pred), BASIC_BLOCK (succ)) | |
d675a426 | 6940 | != EDGE_INDEX_NO_EDGE && found_edge == 0) |
410538ea | 6941 | fprintf (f, "*** Edge (%d, %d) has index %d, but there is no edge\n", |
c9bacfdb | 6942 | pred, succ, EDGE_INDEX (elist, BASIC_BLOCK (pred), |
d675a426 | 6943 | BASIC_BLOCK (succ))); |
410538ea | 6944 | } |
c9bacfdb KH |
6945 | for (succ = 0; succ < n_basic_blocks; succ++) |
6946 | { | |
6947 | basic_block p = ENTRY_BLOCK_PTR; | |
6948 | basic_block s = BASIC_BLOCK (succ); | |
410538ea | 6949 | |
c9bacfdb | 6950 | int found_edge = 0; |
410538ea | 6951 | |
c9bacfdb KH |
6952 | for (e = p->succ; e; e = e->succ_next) |
6953 | if (e->dest == s) | |
6954 | { | |
6955 | found_edge = 1; | |
6956 | break; | |
6957 | } | |
6958 | for (e = s->pred; e; e = e->pred_next) | |
6959 | if (e->src == p) | |
6960 | { | |
6961 | found_edge = 1; | |
6962 | break; | |
6963 | } | |
6964 | if (EDGE_INDEX (elist, ENTRY_BLOCK_PTR, BASIC_BLOCK (succ)) | |
6965 | == EDGE_INDEX_NO_EDGE && found_edge != 0) | |
6966 | fprintf (f, "*** Edge (entry, %d) appears to not have an index\n", | |
6967 | succ); | |
6968 | if (EDGE_INDEX (elist, ENTRY_BLOCK_PTR, BASIC_BLOCK (succ)) | |
6969 | != EDGE_INDEX_NO_EDGE && found_edge == 0) | |
6970 | fprintf (f, "*** Edge (entry, %d) has index %d, but no edge exists\n", | |
6971 | succ, EDGE_INDEX (elist, ENTRY_BLOCK_PTR, | |
6972 | BASIC_BLOCK (succ))); | |
6973 | } | |
6974 | for (pred = 0; pred < n_basic_blocks; pred++) | |
6975 | { | |
6976 | basic_block p = BASIC_BLOCK (pred); | |
6977 | basic_block s = EXIT_BLOCK_PTR; | |
410538ea | 6978 | |
c9bacfdb | 6979 | int found_edge = 0; |
410538ea | 6980 | |
c9bacfdb KH |
6981 | for (e = p->succ; e; e = e->succ_next) |
6982 | if (e->dest == s) | |
6983 | { | |
6984 | found_edge = 1; | |
6985 | break; | |
6986 | } | |
6987 | for (e = s->pred; e; e = e->pred_next) | |
6988 | if (e->src == p) | |
6989 | { | |
6990 | found_edge = 1; | |
6991 | break; | |
6992 | } | |
6993 | if (EDGE_INDEX (elist, BASIC_BLOCK (pred), EXIT_BLOCK_PTR) | |
6994 | == EDGE_INDEX_NO_EDGE && found_edge != 0) | |
6995 | fprintf (f, "*** Edge (%d, exit) appears to not have an index\n", | |
6996 | pred); | |
6997 | if (EDGE_INDEX (elist, BASIC_BLOCK (pred), EXIT_BLOCK_PTR) | |
6998 | != EDGE_INDEX_NO_EDGE && found_edge == 0) | |
6999 | fprintf (f, "*** Edge (%d, exit) has index %d, but no edge exists\n", | |
7000 | pred, EDGE_INDEX (elist, BASIC_BLOCK (pred), | |
7001 | EXIT_BLOCK_PTR)); | |
7002 | } | |
410538ea AM |
7003 | } |
7004 | ||
7005 | /* This routine will determine what, if any, edge there is between | |
7006 | a specified predecessor and successor. */ | |
c9bacfdb | 7007 | |
410538ea AM |
7008 | int |
7009 | find_edge_index (edge_list, pred, succ) | |
7010 | struct edge_list *edge_list; | |
d675a426 | 7011 | basic_block pred, succ; |
410538ea AM |
7012 | { |
7013 | int x; | |
7014 | for (x = 0; x < NUM_EDGES (edge_list); x++) | |
7015 | { | |
d675a426 AM |
7016 | if (INDEX_EDGE_PRED_BB (edge_list, x) == pred |
7017 | && INDEX_EDGE_SUCC_BB (edge_list, x) == succ) | |
410538ea AM |
7018 | return x; |
7019 | } | |
7020 | return (EDGE_INDEX_NO_EDGE); | |
7021 | } | |
7022 | ||
87fdf7ff | 7023 | /* This function will remove an edge from the flow graph. */ |
c9bacfdb | 7024 | |
69732dcb | 7025 | void |
87fdf7ff AM |
7026 | remove_edge (e) |
7027 | edge e; | |
7028 | { | |
7029 | edge last_pred = NULL; | |
7030 | edge last_succ = NULL; | |
7031 | edge tmp; | |
7032 | basic_block src, dest; | |
7033 | src = e->src; | |
7034 | dest = e->dest; | |
7035 | for (tmp = src->succ; tmp && tmp != e; tmp = tmp->succ_next) | |
7036 | last_succ = tmp; | |
7037 | ||
7038 | if (!tmp) | |
7039 | abort (); | |
7040 | if (last_succ) | |
7041 | last_succ->succ_next = e->succ_next; | |
7042 | else | |
7043 | src->succ = e->succ_next; | |
7044 | ||
7045 | for (tmp = dest->pred; tmp && tmp != e; tmp = tmp->pred_next) | |
7046 | last_pred = tmp; | |
7047 | ||
7048 | if (!tmp) | |
7049 | abort (); | |
7050 | if (last_pred) | |
7051 | last_pred->pred_next = e->pred_next; | |
7052 | else | |
7053 | dest->pred = e->pred_next; | |
7054 | ||
d3a923ee | 7055 | n_edges--; |
87fdf7ff | 7056 | free (e); |
87fdf7ff AM |
7057 | } |
7058 | ||
7059 | /* This routine will remove any fake successor edges for a basic block. | |
7060 | When the edge is removed, it is also removed from whatever predecessor | |
7061 | list it is in. */ | |
c9bacfdb | 7062 | |
87fdf7ff AM |
7063 | static void |
7064 | remove_fake_successors (bb) | |
7065 | basic_block bb; | |
7066 | { | |
7067 | edge e; | |
c9bacfdb | 7068 | for (e = bb->succ; e;) |
87fdf7ff AM |
7069 | { |
7070 | edge tmp = e; | |
7071 | e = e->succ_next; | |
7072 | if ((tmp->flags & EDGE_FAKE) == EDGE_FAKE) | |
7073 | remove_edge (tmp); | |
7074 | } | |
7075 | } | |
7076 | ||
7077 | /* This routine will remove all fake edges from the flow graph. If | |
7078 | we remove all fake successors, it will automatically remove all | |
7079 | fake predecessors. */ | |
c9bacfdb | 7080 | |
87fdf7ff AM |
7081 | void |
7082 | remove_fake_edges () | |
7083 | { | |
7084 | int x; | |
87fdf7ff AM |
7085 | |
7086 | for (x = 0; x < n_basic_blocks; x++) | |
d3a923ee RH |
7087 | remove_fake_successors (BASIC_BLOCK (x)); |
7088 | ||
c7d04f29 | 7089 | /* We've handled all successors except the entry block's. */ |
87fdf7ff AM |
7090 | remove_fake_successors (ENTRY_BLOCK_PTR); |
7091 | } | |
7092 | ||
4eb00163 | 7093 | /* This function will add a fake edge between any block which has no |
87fdf7ff AM |
7094 | successors, and the exit block. Some data flow equations require these |
7095 | edges to exist. */ | |
c9bacfdb | 7096 | |
87fdf7ff | 7097 | void |
c7d04f29 | 7098 | add_noreturn_fake_exit_edges () |
87fdf7ff AM |
7099 | { |
7100 | int x; | |
7101 | ||
7102 | for (x = 0; x < n_basic_blocks; x++) | |
7103 | if (BASIC_BLOCK (x)->succ == NULL) | |
dbf08f94 | 7104 | make_edge (NULL, BASIC_BLOCK (x), EXIT_BLOCK_PTR, EDGE_FAKE); |
87fdf7ff | 7105 | } |
f008a564 | 7106 | |
b53978a3 JO |
7107 | /* This function adds a fake edge between any infinite loops to the |
7108 | exit block. Some optimizations require a path from each node to | |
7109 | the exit node. | |
f008a564 | 7110 | |
b53978a3 JO |
7111 | See also Morgan, Figure 3.10, pp. 82-83. |
7112 | ||
7113 | The current implementation is ugly, not attempting to minimize the | |
7114 | number of inserted fake edges. To reduce the number of fake edges | |
7115 | to insert, add fake edges from _innermost_ loops containing only | |
c9bacfdb KH |
7116 | nodes not reachable from the exit block. */ |
7117 | ||
b53978a3 JO |
7118 | void |
7119 | connect_infinite_loops_to_exit () | |
7120 | { | |
7121 | basic_block unvisited_block; | |
7122 | ||
7123 | /* Perform depth-first search in the reverse graph to find nodes | |
c9bacfdb | 7124 | reachable from the exit block. */ |
b53978a3 JO |
7125 | struct depth_first_search_dsS dfs_ds; |
7126 | ||
7127 | flow_dfs_compute_reverse_init (&dfs_ds); | |
7128 | flow_dfs_compute_reverse_add_bb (&dfs_ds, EXIT_BLOCK_PTR); | |
c9bacfdb KH |
7129 | |
7130 | /* Repeatedly add fake edges, updating the unreachable nodes. */ | |
b53978a3 JO |
7131 | while (1) |
7132 | { | |
7133 | unvisited_block = flow_dfs_compute_reverse_execute (&dfs_ds); | |
7134 | if (!unvisited_block) | |
7135 | break; | |
7136 | make_edge (NULL, unvisited_block, EXIT_BLOCK_PTR, EDGE_FAKE); | |
7137 | flow_dfs_compute_reverse_add_bb (&dfs_ds, unvisited_block); | |
7138 | } | |
7139 | ||
7140 | flow_dfs_compute_reverse_finish (&dfs_ds); | |
7141 | ||
7142 | return; | |
7143 | } | |
7144 | ||
7145 | /* Redirect an edge's successor from one block to another. */ | |
c9bacfdb | 7146 | |
f008a564 RH |
7147 | void |
7148 | redirect_edge_succ (e, new_succ) | |
7149 | edge e; | |
7150 | basic_block new_succ; | |
7151 | { | |
7152 | edge *pe; | |
7153 | ||
7154 | /* Disconnect the edge from the old successor block. */ | |
c9bacfdb | 7155 | for (pe = &e->dest->pred; *pe != e; pe = &(*pe)->pred_next) |
f008a564 RH |
7156 | continue; |
7157 | *pe = (*pe)->pred_next; | |
7158 | ||
7159 | /* Reconnect the edge to the new successor block. */ | |
7160 | e->pred_next = new_succ->pred; | |
7161 | new_succ->pred = e; | |
7162 | e->dest = new_succ; | |
7163 | } | |
7164 | ||
7165 | /* Redirect an edge's predecessor from one block to another. */ | |
c9bacfdb | 7166 | |
f008a564 RH |
7167 | void |
7168 | redirect_edge_pred (e, new_pred) | |
7169 | edge e; | |
7170 | basic_block new_pred; | |
7171 | { | |
7172 | edge *pe; | |
7173 | ||
7174 | /* Disconnect the edge from the old predecessor block. */ | |
c9bacfdb | 7175 | for (pe = &e->src->succ; *pe != e; pe = &(*pe)->succ_next) |
f008a564 RH |
7176 | continue; |
7177 | *pe = (*pe)->succ_next; | |
7178 | ||
7179 | /* Reconnect the edge to the new predecessor block. */ | |
7180 | e->succ_next = new_pred->succ; | |
7181 | new_pred->succ = e; | |
7182 | e->src = new_pred; | |
7183 | } | |
4dc9341c MH |
7184 | \f |
7185 | /* Dump the list of basic blocks in the bitmap NODES. */ | |
c9bacfdb | 7186 | |
135ebc36 | 7187 | static void |
4dc9341c MH |
7188 | flow_nodes_print (str, nodes, file) |
7189 | const char *str; | |
7190 | const sbitmap nodes; | |
7191 | FILE *file; | |
7192 | { | |
7193 | int node; | |
7194 | ||
135ebc36 MH |
7195 | if (! nodes) |
7196 | return; | |
7197 | ||
4dc9341c MH |
7198 | fprintf (file, "%s { ", str); |
7199 | EXECUTE_IF_SET_IN_SBITMAP (nodes, 0, node, {fprintf (file, "%d ", node);}); | |
7200 | fputs ("}\n", file); | |
7201 | } | |
7202 | ||
c9bacfdb | 7203 | |
135ebc36 MH |
7204 | /* Dump the list of edges in the array EDGE_LIST. */ |
7205 | ||
7206 | static void | |
7207 | flow_edge_list_print (str, edge_list, num_edges, file) | |
4dc9341c | 7208 | const char *str; |
135ebc36 | 7209 | const edge *edge_list; |
4dc9341c MH |
7210 | int num_edges; |
7211 | FILE *file; | |
7212 | { | |
7213 | int i; | |
7214 | ||
135ebc36 MH |
7215 | if (! edge_list) |
7216 | return; | |
7217 | ||
4dc9341c MH |
7218 | fprintf (file, "%s { ", str); |
7219 | for (i = 0; i < num_edges; i++) | |
135ebc36 MH |
7220 | fprintf (file, "%d->%d ", edge_list[i]->src->index, |
7221 | edge_list[i]->dest->index); | |
4dc9341c MH |
7222 | fputs ("}\n", file); |
7223 | } | |
7224 | ||
135ebc36 | 7225 | |
4dc9341c | 7226 | /* Dump loop related CFG information. */ |
c9bacfdb | 7227 | |
4dc9341c MH |
7228 | static void |
7229 | flow_loops_cfg_dump (loops, file) | |
7230 | const struct loops *loops; | |
7231 | FILE *file; | |
7232 | { | |
7233 | int i; | |
7234 | ||
7235 | if (! loops->num || ! file || ! loops->cfg.dom) | |
7236 | return; | |
7237 | ||
7238 | for (i = 0; i < n_basic_blocks; i++) | |
7239 | { | |
7240 | edge succ; | |
7241 | ||
7242 | fprintf (file, ";; %d succs { ", i); | |
7243 | for (succ = BASIC_BLOCK (i)->succ; succ; succ = succ->succ_next) | |
7244 | fprintf (file, "%d ", succ->dest->index); | |
c9bacfdb | 7245 | flow_nodes_print ("} dom", loops->cfg.dom[i], file); |
4dc9341c MH |
7246 | } |
7247 | ||
4dc9341c MH |
7248 | /* Dump the DFS node order. */ |
7249 | if (loops->cfg.dfs_order) | |
7250 | { | |
7251 | fputs (";; DFS order: ", file); | |
7252 | for (i = 0; i < n_basic_blocks; i++) | |
7253 | fprintf (file, "%d ", loops->cfg.dfs_order[i]); | |
7254 | fputs ("\n", file); | |
7255 | } | |
c34d5374 MH |
7256 | /* Dump the reverse completion node order. */ |
7257 | if (loops->cfg.rc_order) | |
7258 | { | |
7259 | fputs (";; RC order: ", file); | |
7260 | for (i = 0; i < n_basic_blocks; i++) | |
7261 | fprintf (file, "%d ", loops->cfg.rc_order[i]); | |
7262 | fputs ("\n", file); | |
7263 | } | |
4dc9341c MH |
7264 | } |
7265 | ||
4dc9341c | 7266 | /* Return non-zero if the nodes of LOOP are a subset of OUTER. */ |
c9bacfdb | 7267 | |
272df862 | 7268 | static int |
4dc9341c MH |
7269 | flow_loop_nested_p (outer, loop) |
7270 | struct loop *outer; | |
7271 | struct loop *loop; | |
7272 | { | |
7273 | return sbitmap_a_subset_b_p (loop->nodes, outer->nodes); | |
7274 | } | |
7275 | ||
c9bacfdb | 7276 | |
6057c0e6 MH |
7277 | /* Dump the loop information specified by LOOP to the stream FILE |
7278 | using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ | |
c9bacfdb | 7279 | void |
6057c0e6 MH |
7280 | flow_loop_dump (loop, file, loop_dump_aux, verbose) |
7281 | const struct loop *loop; | |
7282 | FILE *file; | |
31a1fdad | 7283 | void (*loop_dump_aux) PARAMS((const struct loop *, FILE *, int)); |
6057c0e6 MH |
7284 | int verbose; |
7285 | { | |
7286 | if (! loop || ! loop->header) | |
7287 | return; | |
7288 | ||
7289 | fprintf (file, ";;\n;; Loop %d (%d to %d):%s%s\n", | |
7290 | loop->num, INSN_UID (loop->first->head), | |
7291 | INSN_UID (loop->last->end), | |
7292 | loop->shared ? " shared" : "", | |
7293 | loop->invalid ? " invalid" : ""); | |
7294 | fprintf (file, ";; header %d, latch %d, pre-header %d, first %d, last %d\n", | |
7295 | loop->header->index, loop->latch->index, | |
7296 | loop->pre_header ? loop->pre_header->index : -1, | |
7297 | loop->first->index, loop->last->index); | |
7298 | fprintf (file, ";; depth %d, level %d, outer %ld\n", | |
7299 | loop->depth, loop->level, | |
7300 | (long) (loop->outer ? loop->outer->num : -1)); | |
7301 | ||
4a7da9b5 MH |
7302 | if (loop->pre_header_edges) |
7303 | flow_edge_list_print (";; pre-header edges", loop->pre_header_edges, | |
7304 | loop->num_pre_header_edges, file); | |
5d6a16e2 | 7305 | flow_edge_list_print (";; entry edges", loop->entry_edges, |
135ebc36 | 7306 | loop->num_entries, file); |
6057c0e6 MH |
7307 | fprintf (file, ";; %d", loop->num_nodes); |
7308 | flow_nodes_print (" nodes", loop->nodes, file); | |
5d6a16e2 | 7309 | flow_edge_list_print (";; exit edges", loop->exit_edges, |
135ebc36 | 7310 | loop->num_exits, file); |
5d6a16e2 MH |
7311 | if (loop->exits_doms) |
7312 | flow_nodes_print (";; exit doms", loop->exits_doms, file); | |
6057c0e6 MH |
7313 | if (loop_dump_aux) |
7314 | loop_dump_aux (loop, file, verbose); | |
7315 | } | |
7316 | ||
7317 | ||
7318 | /* Dump the loop information specified by LOOPS to the stream FILE, | |
7319 | using auxiliary dump callback function LOOP_DUMP_AUX if non null. */ | |
7320 | void | |
7321 | flow_loops_dump (loops, file, loop_dump_aux, verbose) | |
4dc9341c MH |
7322 | const struct loops *loops; |
7323 | FILE *file; | |
31a1fdad | 7324 | void (*loop_dump_aux) PARAMS((const struct loop *, FILE *, int)); |
4dc9341c MH |
7325 | int verbose; |
7326 | { | |
7327 | int i; | |
7328 | int num_loops; | |
7329 | ||
7330 | num_loops = loops->num; | |
7331 | if (! num_loops || ! file) | |
7332 | return; | |
7333 | ||
6057c0e6 | 7334 | fprintf (file, ";; %d loops found, %d levels\n", |
d6181b1b | 7335 | num_loops, loops->levels); |
4dc9341c MH |
7336 | |
7337 | for (i = 0; i < num_loops; i++) | |
7338 | { | |
7339 | struct loop *loop = &loops->array[i]; | |
7340 | ||
6057c0e6 | 7341 | flow_loop_dump (loop, file, loop_dump_aux, verbose); |
4dc9341c MH |
7342 | |
7343 | if (loop->shared) | |
7344 | { | |
7345 | int j; | |
7346 | ||
7347 | for (j = 0; j < i; j++) | |
7348 | { | |
7349 | struct loop *oloop = &loops->array[j]; | |
7350 | ||
7351 | if (loop->header == oloop->header) | |
7352 | { | |
7353 | int disjoint; | |
7354 | int smaller; | |
7355 | ||
7356 | smaller = loop->num_nodes < oloop->num_nodes; | |
7357 | ||
7358 | /* If the union of LOOP and OLOOP is different than | |
7359 | the larger of LOOP and OLOOP then LOOP and OLOOP | |
7360 | must be disjoint. */ | |
b760c4b1 MH |
7361 | disjoint = ! flow_loop_nested_p (smaller ? loop : oloop, |
7362 | smaller ? oloop : loop); | |
6057c0e6 | 7363 | fprintf (file, |
c34d5374 | 7364 | ";; loop header %d shared by loops %d, %d %s\n", |
4dc9341c MH |
7365 | loop->header->index, i, j, |
7366 | disjoint ? "disjoint" : "nested"); | |
7367 | } | |
7368 | } | |
7369 | } | |
4dc9341c MH |
7370 | } |
7371 | ||
7372 | if (verbose) | |
7373 | flow_loops_cfg_dump (loops, file); | |
7374 | } | |
7375 | ||
6057c0e6 | 7376 | |
4dc9341c | 7377 | /* Free all the memory allocated for LOOPS. */ |
c9bacfdb KH |
7378 | |
7379 | void | |
4dc9341c | 7380 | flow_loops_free (loops) |
c9bacfdb | 7381 | struct loops *loops; |
4dc9341c MH |
7382 | { |
7383 | if (loops->array) | |
7384 | { | |
7385 | int i; | |
7386 | ||
7387 | if (! loops->num) | |
7388 | abort (); | |
7389 | ||
7390 | /* Free the loop descriptors. */ | |
7391 | for (i = 0; i < loops->num; i++) | |
7392 | { | |
7393 | struct loop *loop = &loops->array[i]; | |
c9bacfdb | 7394 | |
4a7da9b5 MH |
7395 | if (loop->pre_header_edges) |
7396 | free (loop->pre_header_edges); | |
4dc9341c MH |
7397 | if (loop->nodes) |
7398 | sbitmap_free (loop->nodes); | |
135ebc36 MH |
7399 | if (loop->entry_edges) |
7400 | free (loop->entry_edges); | |
7401 | if (loop->exit_edges) | |
7402 | free (loop->exit_edges); | |
5d6a16e2 MH |
7403 | if (loop->exits_doms) |
7404 | sbitmap_free (loop->exits_doms); | |
4dc9341c MH |
7405 | } |
7406 | free (loops->array); | |
7407 | loops->array = NULL; | |
c9bacfdb | 7408 | |
4dc9341c MH |
7409 | if (loops->cfg.dom) |
7410 | sbitmap_vector_free (loops->cfg.dom); | |
7411 | if (loops->cfg.dfs_order) | |
7412 | free (loops->cfg.dfs_order); | |
7413 | ||
5d6a16e2 MH |
7414 | if (loops->shared_headers) |
7415 | sbitmap_free (loops->shared_headers); | |
4dc9341c MH |
7416 | } |
7417 | } | |
7418 | ||
6057c0e6 | 7419 | |
135ebc36 MH |
7420 | /* Find the entry edges into the loop with header HEADER and nodes |
7421 | NODES and store in ENTRY_EDGES array. Return the number of entry | |
7422 | edges from the loop. */ | |
7423 | ||
7424 | static int | |
7425 | flow_loop_entry_edges_find (header, nodes, entry_edges) | |
7426 | basic_block header; | |
7427 | const sbitmap nodes; | |
7428 | edge **entry_edges; | |
7429 | { | |
7430 | edge e; | |
7431 | int num_entries; | |
7432 | ||
7433 | *entry_edges = NULL; | |
7434 | ||
7435 | num_entries = 0; | |
7436 | for (e = header->pred; e; e = e->pred_next) | |
7437 | { | |
7438 | basic_block src = e->src; | |
7439 | ||
7440 | if (src == ENTRY_BLOCK_PTR || ! TEST_BIT (nodes, src->index)) | |
7441 | num_entries++; | |
7442 | } | |
7443 | ||
7444 | if (! num_entries) | |
7445 | abort (); | |
7446 | ||
7447 | *entry_edges = (edge *) xmalloc (num_entries * sizeof (edge *)); | |
7448 | ||
7449 | num_entries = 0; | |
7450 | for (e = header->pred; e; e = e->pred_next) | |
7451 | { | |
7452 | basic_block src = e->src; | |
7453 | ||
7454 | if (src == ENTRY_BLOCK_PTR || ! TEST_BIT (nodes, src->index)) | |
7455 | (*entry_edges)[num_entries++] = e; | |
7456 | } | |
7457 | ||
7458 | return num_entries; | |
7459 | } | |
7460 | ||
7461 | ||
7462 | /* Find the exit edges from the loop using the bitmap of loop nodes | |
7463 | NODES and store in EXIT_EDGES array. Return the number of | |
7464 | exit edges from the loop. */ | |
c9bacfdb | 7465 | |
4dc9341c | 7466 | static int |
135ebc36 | 7467 | flow_loop_exit_edges_find (nodes, exit_edges) |
4dc9341c | 7468 | const sbitmap nodes; |
135ebc36 | 7469 | edge **exit_edges; |
4dc9341c MH |
7470 | { |
7471 | edge e; | |
7472 | int node; | |
7473 | int num_exits; | |
7474 | ||
135ebc36 | 7475 | *exit_edges = NULL; |
4dc9341c MH |
7476 | |
7477 | /* Check all nodes within the loop to see if there are any | |
7478 | successors not in the loop. Note that a node may have multiple | |
135ebc36 MH |
7479 | exiting edges ????? A node can have one jumping edge and one fallthru |
7480 | edge so only one of these can exit the loop. */ | |
4dc9341c MH |
7481 | num_exits = 0; |
7482 | EXECUTE_IF_SET_IN_SBITMAP (nodes, 0, node, { | |
7483 | for (e = BASIC_BLOCK (node)->succ; e; e = e->succ_next) | |
7484 | { | |
135ebc36 | 7485 | basic_block dest = e->dest; |
4dc9341c MH |
7486 | |
7487 | if (dest == EXIT_BLOCK_PTR || ! TEST_BIT (nodes, dest->index)) | |
7488 | num_exits++; | |
7489 | } | |
7490 | }); | |
7491 | ||
7492 | if (! num_exits) | |
7493 | return 0; | |
7494 | ||
135ebc36 | 7495 | *exit_edges = (edge *) xmalloc (num_exits * sizeof (edge *)); |
4dc9341c MH |
7496 | |
7497 | /* Store all exiting edges into an array. */ | |
7498 | num_exits = 0; | |
7499 | EXECUTE_IF_SET_IN_SBITMAP (nodes, 0, node, { | |
7500 | for (e = BASIC_BLOCK (node)->succ; e; e = e->succ_next) | |
7501 | { | |
135ebc36 | 7502 | basic_block dest = e->dest; |
4dc9341c MH |
7503 | |
7504 | if (dest == EXIT_BLOCK_PTR || ! TEST_BIT (nodes, dest->index)) | |
135ebc36 | 7505 | (*exit_edges)[num_exits++] = e; |
4dc9341c MH |
7506 | } |
7507 | }); | |
7508 | ||
7509 | return num_exits; | |
7510 | } | |
7511 | ||
135ebc36 | 7512 | |
4dc9341c MH |
7513 | /* Find the nodes contained within the loop with header HEADER and |
7514 | latch LATCH and store in NODES. Return the number of nodes within | |
7515 | the loop. */ | |
c9bacfdb KH |
7516 | |
7517 | static int | |
4dc9341c MH |
7518 | flow_loop_nodes_find (header, latch, nodes) |
7519 | basic_block header; | |
7520 | basic_block latch; | |
7521 | sbitmap nodes; | |
7522 | { | |
7523 | basic_block *stack; | |
7524 | int sp; | |
7525 | int num_nodes = 0; | |
7526 | ||
7527 | stack = (basic_block *) xmalloc (n_basic_blocks * sizeof (basic_block)); | |
7528 | sp = 0; | |
7529 | ||
7530 | /* Start with only the loop header in the set of loop nodes. */ | |
7531 | sbitmap_zero (nodes); | |
7532 | SET_BIT (nodes, header->index); | |
7533 | num_nodes++; | |
ce4bbac7 | 7534 | header->loop_depth++; |
4dc9341c MH |
7535 | |
7536 | /* Push the loop latch on to the stack. */ | |
7537 | if (! TEST_BIT (nodes, latch->index)) | |
7538 | { | |
7539 | SET_BIT (nodes, latch->index); | |
ce4bbac7 | 7540 | latch->loop_depth++; |
4dc9341c MH |
7541 | num_nodes++; |
7542 | stack[sp++] = latch; | |
7543 | } | |
7544 | ||
7545 | while (sp) | |
7546 | { | |
7547 | basic_block node; | |
7548 | edge e; | |
7549 | ||
7550 | node = stack[--sp]; | |
7551 | for (e = node->pred; e; e = e->pred_next) | |
7552 | { | |
7553 | basic_block ancestor = e->src; | |
c9bacfdb | 7554 | |
4dc9341c MH |
7555 | /* If each ancestor not marked as part of loop, add to set of |
7556 | loop nodes and push on to stack. */ | |
7557 | if (ancestor != ENTRY_BLOCK_PTR | |
7558 | && ! TEST_BIT (nodes, ancestor->index)) | |
7559 | { | |
7560 | SET_BIT (nodes, ancestor->index); | |
ce4bbac7 | 7561 | ancestor->loop_depth++; |
4dc9341c MH |
7562 | num_nodes++; |
7563 | stack[sp++] = ancestor; | |
7564 | } | |
7565 | } | |
7566 | } | |
7567 | free (stack); | |
7568 | return num_nodes; | |
7569 | } | |
7570 | ||
4dc9341c | 7571 | /* Compute the depth first search order and store in the array |
c34d5374 MH |
7572 | DFS_ORDER if non-zero, marking the nodes visited in VISITED. If |
7573 | RC_ORDER is non-zero, return the reverse completion number for each | |
7574 | node. Returns the number of nodes visited. A depth first search | |
7575 | tries to get as far away from the starting point as quickly as | |
7576 | possible. */ | |
c9bacfdb | 7577 | |
4dc9341c | 7578 | static int |
c34d5374 | 7579 | flow_depth_first_order_compute (dfs_order, rc_order) |
4dc9341c | 7580 | int *dfs_order; |
c34d5374 | 7581 | int *rc_order; |
4dc9341c | 7582 | { |
4dc9341c MH |
7583 | edge *stack; |
7584 | int sp; | |
7585 | int dfsnum = 0; | |
c34d5374 | 7586 | int rcnum = n_basic_blocks - 1; |
4dc9341c MH |
7587 | sbitmap visited; |
7588 | ||
7589 | /* Allocate stack for back-tracking up CFG. */ | |
628f05b4 | 7590 | stack = (edge *) xmalloc ((n_basic_blocks + 1) * sizeof (edge)); |
4dc9341c MH |
7591 | sp = 0; |
7592 | ||
7593 | /* Allocate bitmap to track nodes that have been visited. */ | |
7594 | visited = sbitmap_alloc (n_basic_blocks); | |
7595 | ||
7596 | /* None of the nodes in the CFG have been visited yet. */ | |
7597 | sbitmap_zero (visited); | |
c9bacfdb | 7598 | |
628f05b4 MH |
7599 | /* Push the first edge on to the stack. */ |
7600 | stack[sp++] = ENTRY_BLOCK_PTR->succ; | |
7601 | ||
7602 | while (sp) | |
4dc9341c | 7603 | { |
628f05b4 MH |
7604 | edge e; |
7605 | basic_block src; | |
7606 | basic_block dest; | |
7607 | ||
7608 | /* Look at the edge on the top of the stack. */ | |
7609 | e = stack[sp - 1]; | |
7610 | src = e->src; | |
7611 | dest = e->dest; | |
c9bacfdb | 7612 | |
628f05b4 MH |
7613 | /* Check if the edge destination has been visited yet. */ |
7614 | if (dest != EXIT_BLOCK_PTR && ! TEST_BIT (visited, dest->index)) | |
4dc9341c | 7615 | { |
628f05b4 MH |
7616 | /* Mark that we have visited the destination. */ |
7617 | SET_BIT (visited, dest->index); | |
c9bacfdb | 7618 | |
c34d5374 MH |
7619 | if (dfs_order) |
7620 | dfs_order[dfsnum++] = dest->index; | |
628f05b4 | 7621 | |
c9bacfdb KH |
7622 | if (dest->succ) |
7623 | { | |
7624 | /* Since the DEST node has been visited for the first | |
7625 | time, check its successors. */ | |
7626 | stack[sp++] = dest->succ; | |
7627 | } | |
7628 | else | |
7629 | { | |
7630 | /* There are no successors for the DEST node so assign | |
7631 | its reverse completion number. */ | |
c34d5374 MH |
7632 | if (rc_order) |
7633 | rc_order[rcnum--] = dest->index; | |
c9bacfdb | 7634 | } |
4dc9341c MH |
7635 | } |
7636 | else | |
7637 | { | |
628f05b4 | 7638 | if (! e->succ_next && src != ENTRY_BLOCK_PTR) |
c9bacfdb KH |
7639 | { |
7640 | /* There are no more successors for the SRC node | |
7641 | so assign its reverse completion number. */ | |
c34d5374 MH |
7642 | if (rc_order) |
7643 | rc_order[rcnum--] = src->index; | |
c9bacfdb KH |
7644 | } |
7645 | ||
628f05b4 MH |
7646 | if (e->succ_next) |
7647 | stack[sp - 1] = e->succ_next; | |
7648 | else | |
7649 | sp--; | |
4dc9341c MH |
7650 | } |
7651 | } | |
628f05b4 | 7652 | |
4dc9341c MH |
7653 | free (stack); |
7654 | sbitmap_free (visited); | |
7655 | ||
7656 | /* The number of nodes visited should not be greater than | |
7657 | n_basic_blocks. */ | |
7658 | if (dfsnum > n_basic_blocks) | |
7659 | abort (); | |
7660 | ||
7661 | /* There are some nodes left in the CFG that are unreachable. */ | |
7662 | if (dfsnum < n_basic_blocks) | |
7663 | abort (); | |
7664 | return dfsnum; | |
7665 | } | |
7666 | ||
b53978a3 JO |
7667 | /* Compute the depth first search order on the _reverse_ graph and |
7668 | store in the array DFS_ORDER, marking the nodes visited in VISITED. | |
7669 | Returns the number of nodes visited. | |
7670 | ||
7671 | The computation is split into three pieces: | |
7672 | ||
7673 | flow_dfs_compute_reverse_init () creates the necessary data | |
7674 | structures. | |
7675 | ||
7676 | flow_dfs_compute_reverse_add_bb () adds a basic block to the data | |
7677 | structures. The block will start the search. | |
7678 | ||
7679 | flow_dfs_compute_reverse_execute () continues (or starts) the | |
7680 | search using the block on the top of the stack, stopping when the | |
7681 | stack is empty. | |
7682 | ||
7683 | flow_dfs_compute_reverse_finish () destroys the necessary data | |
7684 | structures. | |
7685 | ||
7686 | Thus, the user will probably call ..._init(), call ..._add_bb() to | |
7687 | add a beginning basic block to the stack, call ..._execute(), | |
7688 | possibly add another bb to the stack and again call ..._execute(), | |
c9bacfdb | 7689 | ..., and finally call _finish(). */ |
b53978a3 JO |
7690 | |
7691 | /* Initialize the data structures used for depth-first search on the | |
7692 | reverse graph. If INITIALIZE_STACK is nonzero, the exit block is | |
7693 | added to the basic block stack. DATA is the current depth-first | |
7694 | search context. If INITIALIZE_STACK is non-zero, there is an | |
7695 | element on the stack. */ | |
7696 | ||
7697 | static void | |
7698 | flow_dfs_compute_reverse_init (data) | |
7699 | depth_first_search_ds data; | |
7700 | { | |
7701 | /* Allocate stack for back-tracking up CFG. */ | |
7702 | data->stack = | |
c9bacfdb | 7703 | (basic_block *) xmalloc ((n_basic_blocks - (INVALID_BLOCK + 1)) |
b53978a3 JO |
7704 | * sizeof (basic_block)); |
7705 | data->sp = 0; | |
7706 | ||
7707 | /* Allocate bitmap to track nodes that have been visited. */ | |
c9bacfdb | 7708 | data->visited_blocks = sbitmap_alloc (n_basic_blocks - (INVALID_BLOCK + 1)); |
b53978a3 JO |
7709 | |
7710 | /* None of the nodes in the CFG have been visited yet. */ | |
7711 | sbitmap_zero (data->visited_blocks); | |
7712 | ||
7713 | return; | |
7714 | } | |
7715 | ||
7716 | /* Add the specified basic block to the top of the dfs data | |
7717 | structures. When the search continues, it will start at the | |
c9bacfdb | 7718 | block. */ |
b53978a3 JO |
7719 | |
7720 | static void | |
7721 | flow_dfs_compute_reverse_add_bb (data, bb) | |
7722 | depth_first_search_ds data; | |
7723 | basic_block bb; | |
7724 | { | |
7725 | data->stack[data->sp++] = bb; | |
7726 | return; | |
7727 | } | |
7728 | ||
7729 | /* Continue the depth-first search through the reverse graph starting | |
7730 | with the block at the stack's top and ending when the stack is | |
7731 | empty. Visited nodes are marked. Returns an unvisited basic | |
7732 | block, or NULL if there is none available. */ | |
c9bacfdb | 7733 | |
b53978a3 JO |
7734 | static basic_block |
7735 | flow_dfs_compute_reverse_execute (data) | |
7736 | depth_first_search_ds data; | |
7737 | { | |
7738 | basic_block bb; | |
7739 | edge e; | |
7740 | int i; | |
7741 | ||
7742 | while (data->sp > 0) | |
7743 | { | |
7744 | bb = data->stack[--data->sp]; | |
7745 | ||
c9bacfdb KH |
7746 | /* Mark that we have visited this node. */ |
7747 | if (!TEST_BIT (data->visited_blocks, bb->index - (INVALID_BLOCK + 1))) | |
b53978a3 | 7748 | { |
c9bacfdb | 7749 | SET_BIT (data->visited_blocks, bb->index - (INVALID_BLOCK + 1)); |
b53978a3 | 7750 | |
c9bacfdb | 7751 | /* Perform depth-first search on adjacent vertices. */ |
b53978a3 JO |
7752 | for (e = bb->pred; e; e = e->pred_next) |
7753 | flow_dfs_compute_reverse_add_bb (data, e->src); | |
7754 | } | |
7755 | } | |
7756 | ||
c9bacfdb KH |
7757 | /* Determine if there are unvisited basic blocks. */ |
7758 | for (i = n_basic_blocks - (INVALID_BLOCK + 1); --i >= 0;) | |
b53978a3 | 7759 | if (!TEST_BIT (data->visited_blocks, i)) |
c9bacfdb | 7760 | return BASIC_BLOCK (i + (INVALID_BLOCK + 1)); |
b53978a3 JO |
7761 | return NULL; |
7762 | } | |
7763 | ||
7764 | /* Destroy the data structures needed for depth-first search on the | |
c9bacfdb | 7765 | reverse graph. */ |
b53978a3 JO |
7766 | |
7767 | static void | |
7768 | flow_dfs_compute_reverse_finish (data) | |
7769 | depth_first_search_ds data; | |
7770 | { | |
7771 | free (data->stack); | |
7772 | sbitmap_free (data->visited_blocks); | |
7773 | return; | |
7774 | } | |
7775 | ||
5d6a16e2 MH |
7776 | |
7777 | /* Find the root node of the loop pre-header extended basic block and | |
4a7da9b5 | 7778 | the edges along the trace from the root node to the loop header. */ |
5d6a16e2 MH |
7779 | |
7780 | static void | |
7781 | flow_loop_pre_header_scan (loop) | |
7782 | struct loop *loop; | |
7783 | { | |
4a7da9b5 | 7784 | int num = 0; |
5d6a16e2 MH |
7785 | basic_block ebb; |
7786 | ||
4a7da9b5 MH |
7787 | loop->num_pre_header_edges = 0; |
7788 | ||
5d6a16e2 MH |
7789 | if (loop->num_entries != 1) |
7790 | return; | |
7791 | ||
5d6a16e2 | 7792 | ebb = loop->entry_edges[0]->src; |
ef120fc0 MH |
7793 | |
7794 | if (ebb != ENTRY_BLOCK_PTR) | |
5d6a16e2 | 7795 | { |
4a7da9b5 MH |
7796 | edge e; |
7797 | ||
7798 | /* Count number of edges along trace from loop header to | |
7799 | root of pre-header extended basic block. Usually this is | |
7800 | only one or two edges. */ | |
7801 | num++; | |
7802 | while (ebb->pred->src != ENTRY_BLOCK_PTR && ! ebb->pred->pred_next) | |
ef120fc0 MH |
7803 | { |
7804 | ebb = ebb->pred->src; | |
4a7da9b5 MH |
7805 | num++; |
7806 | } | |
7807 | ||
7808 | loop->pre_header_edges = (edge *) xmalloc (num * sizeof (edge *)); | |
7809 | loop->num_pre_header_edges = num; | |
7810 | ||
7811 | /* Store edges in order that they are followed. The source | |
7812 | of the first edge is the root node of the pre-header extended | |
7813 | basic block and the destination of the last last edge is | |
7814 | the loop header. */ | |
7815 | for (e = loop->entry_edges[0]; num; e = e->src->pred) | |
7816 | { | |
7817 | loop->pre_header_edges[--num] = e; | |
ef120fc0 | 7818 | } |
5d6a16e2 | 7819 | } |
5d6a16e2 MH |
7820 | } |
7821 | ||
7822 | ||
4dc9341c MH |
7823 | /* Return the block for the pre-header of the loop with header |
7824 | HEADER where DOM specifies the dominator information. Return NULL if | |
7825 | there is no pre-header. */ | |
c9bacfdb | 7826 | |
4dc9341c MH |
7827 | static basic_block |
7828 | flow_loop_pre_header_find (header, dom) | |
7829 | basic_block header; | |
c9bacfdb | 7830 | const sbitmap *dom; |
4dc9341c MH |
7831 | { |
7832 | basic_block pre_header; | |
7833 | edge e; | |
7834 | ||
7835 | /* If block p is a predecessor of the header and is the only block | |
7836 | that the header does not dominate, then it is the pre-header. */ | |
7837 | pre_header = NULL; | |
7838 | for (e = header->pred; e; e = e->pred_next) | |
7839 | { | |
7840 | basic_block node = e->src; | |
c9bacfdb | 7841 | |
4dc9341c MH |
7842 | if (node != ENTRY_BLOCK_PTR |
7843 | && ! TEST_BIT (dom[node->index], header->index)) | |
7844 | { | |
7845 | if (pre_header == NULL) | |
7846 | pre_header = node; | |
7847 | else | |
7848 | { | |
c9bacfdb | 7849 | /* There are multiple edges into the header from outside |
4dc9341c MH |
7850 | the loop so there is no pre-header block. */ |
7851 | pre_header = NULL; | |
7852 | break; | |
7853 | } | |
7854 | } | |
7855 | } | |
7856 | return pre_header; | |
7857 | } | |
7858 | ||
3abd3239 MH |
7859 | /* Add LOOP to the loop hierarchy tree where PREVLOOP was the loop |
7860 | previously added. The insertion algorithm assumes that the loops | |
7861 | are added in the order found by a depth first search of the CFG. */ | |
c9bacfdb | 7862 | |
4dc9341c | 7863 | static void |
3abd3239 MH |
7864 | flow_loop_tree_node_add (prevloop, loop) |
7865 | struct loop *prevloop; | |
4dc9341c MH |
7866 | struct loop *loop; |
7867 | { | |
4dc9341c | 7868 | |
3abd3239 MH |
7869 | if (flow_loop_nested_p (prevloop, loop)) |
7870 | { | |
7871 | prevloop->inner = loop; | |
7872 | loop->outer = prevloop; | |
7873 | return; | |
7874 | } | |
4dc9341c | 7875 | |
3abd3239 | 7876 | while (prevloop->outer) |
4dc9341c | 7877 | { |
3abd3239 | 7878 | if (flow_loop_nested_p (prevloop->outer, loop)) |
4dc9341c | 7879 | { |
3abd3239 MH |
7880 | prevloop->next = loop; |
7881 | loop->outer = prevloop->outer; | |
4dc9341c MH |
7882 | return; |
7883 | } | |
3abd3239 | 7884 | prevloop = prevloop->outer; |
4dc9341c | 7885 | } |
c9bacfdb | 7886 | |
3abd3239 MH |
7887 | prevloop->next = loop; |
7888 | loop->outer = NULL; | |
4dc9341c MH |
7889 | } |
7890 | ||
4dc9341c | 7891 | /* Build the loop hierarchy tree for LOOPS. */ |
c9bacfdb | 7892 | |
4dc9341c MH |
7893 | static void |
7894 | flow_loops_tree_build (loops) | |
c9bacfdb | 7895 | struct loops *loops; |
4dc9341c MH |
7896 | { |
7897 | int i; | |
7898 | int num_loops; | |
7899 | ||
7900 | num_loops = loops->num; | |
7901 | if (! num_loops) | |
7902 | return; | |
7903 | ||
7904 | /* Root the loop hierarchy tree with the first loop found. | |
c9bacfdb | 7905 | Since we used a depth first search this should be the |
4dc9341c MH |
7906 | outermost loop. */ |
7907 | loops->tree = &loops->array[0]; | |
7908 | loops->tree->outer = loops->tree->inner = loops->tree->next = NULL; | |
7909 | ||
7910 | /* Add the remaining loops to the tree. */ | |
7911 | for (i = 1; i < num_loops; i++) | |
3abd3239 | 7912 | flow_loop_tree_node_add (&loops->array[i - 1], &loops->array[i]); |
4dc9341c MH |
7913 | } |
7914 | ||
4dc9341c | 7915 | /* Helper function to compute loop nesting depth and enclosed loop level |
c9bacfdb | 7916 | for the natural loop specified by LOOP at the loop depth DEPTH. |
4dc9341c | 7917 | Returns the loop level. */ |
c9bacfdb | 7918 | |
4dc9341c MH |
7919 | static int |
7920 | flow_loop_level_compute (loop, depth) | |
7921 | struct loop *loop; | |
7922 | int depth; | |
7923 | { | |
7924 | struct loop *inner; | |
d6181b1b | 7925 | int level = 1; |
4dc9341c MH |
7926 | |
7927 | if (! loop) | |
7928 | return 0; | |
7929 | ||
7930 | /* Traverse loop tree assigning depth and computing level as the | |
7931 | maximum level of all the inner loops of this loop. The loop | |
7932 | level is equivalent to the height of the loop in the loop tree | |
d6181b1b MH |
7933 | and corresponds to the number of enclosed loop levels (including |
7934 | itself). */ | |
4dc9341c MH |
7935 | for (inner = loop->inner; inner; inner = inner->next) |
7936 | { | |
7937 | int ilevel; | |
7938 | ||
7939 | ilevel = flow_loop_level_compute (inner, depth + 1) + 1; | |
7940 | ||
7941 | if (ilevel > level) | |
7942 | level = ilevel; | |
7943 | } | |
7944 | loop->level = level; | |
7945 | loop->depth = depth; | |
7946 | return level; | |
7947 | } | |
7948 | ||
4dc9341c MH |
7949 | /* Compute the loop nesting depth and enclosed loop level for the loop |
7950 | hierarchy tree specfied by LOOPS. Return the maximum enclosed loop | |
7951 | level. */ | |
d4b60170 | 7952 | |
d6181b1b | 7953 | static int |
4dc9341c MH |
7954 | flow_loops_level_compute (loops) |
7955 | struct loops *loops; | |
7956 | { | |
d6181b1b MH |
7957 | struct loop *loop; |
7958 | int level; | |
7959 | int levels = 0; | |
7960 | ||
7961 | /* Traverse all the outer level loops. */ | |
7962 | for (loop = loops->tree; loop; loop = loop->next) | |
7963 | { | |
7964 | level = flow_loop_level_compute (loop, 1); | |
7965 | if (level > levels) | |
7966 | levels = level; | |
7967 | } | |
7968 | return levels; | |
4dc9341c MH |
7969 | } |
7970 | ||
5d6a16e2 | 7971 | |
ce4bbac7 JH |
7972 | /* Find all the natural loops in the function and save in LOOPS structure |
7973 | and recalculate loop_depth information in basic block structures. | |
5d6a16e2 | 7974 | FLAGS controls which loop information is collected. |
4dc9341c | 7975 | Return the number of natural loops found. */ |
d4b60170 | 7976 | |
c9bacfdb | 7977 | int |
5d6a16e2 | 7978 | flow_loops_find (loops, flags) |
c9bacfdb | 7979 | struct loops *loops; |
5d6a16e2 | 7980 | int flags; |
4dc9341c MH |
7981 | { |
7982 | int i; | |
7983 | int b; | |
7984 | int num_loops; | |
7985 | edge e; | |
7986 | sbitmap headers; | |
7987 | sbitmap *dom; | |
7988 | int *dfs_order; | |
c34d5374 | 7989 | int *rc_order; |
c9bacfdb | 7990 | |
5d6a16e2 MH |
7991 | /* This function cannot be repeatedly called with different |
7992 | flags to build up the loop information. The loop tree | |
7993 | must always be built if this function is called. */ | |
7994 | if (! (flags & LOOP_TREE)) | |
7995 | abort (); | |
7996 | ||
7997 | memset (loops, 0, sizeof (*loops)); | |
4dc9341c MH |
7998 | |
7999 | /* Taking care of this degenerate case makes the rest of | |
8000 | this code simpler. */ | |
8001 | if (n_basic_blocks == 0) | |
8002 | return 0; | |
8003 | ||
5d6a16e2 MH |
8004 | dfs_order = NULL; |
8005 | rc_order = NULL; | |
8006 | ||
4dc9341c MH |
8007 | /* Compute the dominators. */ |
8008 | dom = sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks); | |
f8032688 | 8009 | calculate_dominance_info (NULL, dom, CDI_DOMINATORS); |
4dc9341c MH |
8010 | |
8011 | /* Count the number of loop edges (back edges). This should be the | |
5d6a16e2 | 8012 | same as the number of natural loops. */ |
ce4bbac7 | 8013 | |
4dc9341c MH |
8014 | num_loops = 0; |
8015 | for (b = 0; b < n_basic_blocks; b++) | |
8016 | { | |
5d6a16e2 MH |
8017 | basic_block header; |
8018 | ||
8019 | header = BASIC_BLOCK (b); | |
8020 | header->loop_depth = 0; | |
8021 | ||
8022 | for (e = header->pred; e; e = e->pred_next) | |
4dc9341c MH |
8023 | { |
8024 | basic_block latch = e->src; | |
c9bacfdb | 8025 | |
4dc9341c MH |
8026 | /* Look for back edges where a predecessor is dominated |
8027 | by this block. A natural loop has a single entry | |
8028 | node (header) that dominates all the nodes in the | |
8029 | loop. It also has single back edge to the header | |
8030 | from a latch node. Note that multiple natural loops | |
8031 | may share the same header. */ | |
5d6a16e2 MH |
8032 | if (b != header->index) |
8033 | abort (); | |
8034 | ||
4dc9341c MH |
8035 | if (latch != ENTRY_BLOCK_PTR && TEST_BIT (dom[latch->index], b)) |
8036 | num_loops++; | |
8037 | } | |
8038 | } | |
c9bacfdb | 8039 | |
4dc9341c MH |
8040 | if (num_loops) |
8041 | { | |
8042 | /* Compute depth first search order of the CFG so that outer | |
8043 | natural loops will be found before inner natural loops. */ | |
8044 | dfs_order = (int *) xmalloc (n_basic_blocks * sizeof (int)); | |
c34d5374 MH |
8045 | rc_order = (int *) xmalloc (n_basic_blocks * sizeof (int)); |
8046 | flow_depth_first_order_compute (dfs_order, rc_order); | |
4dc9341c MH |
8047 | |
8048 | /* Allocate loop structures. */ | |
d4b60170 RK |
8049 | loops->array |
8050 | = (struct loop *) xcalloc (num_loops, sizeof (struct loop)); | |
c9bacfdb | 8051 | |
4dc9341c MH |
8052 | headers = sbitmap_alloc (n_basic_blocks); |
8053 | sbitmap_zero (headers); | |
8054 | ||
8055 | loops->shared_headers = sbitmap_alloc (n_basic_blocks); | |
8056 | sbitmap_zero (loops->shared_headers); | |
8057 | ||
8058 | /* Find and record information about all the natural loops | |
8059 | in the CFG. */ | |
8060 | num_loops = 0; | |
8061 | for (b = 0; b < n_basic_blocks; b++) | |
8062 | { | |
8063 | basic_block header; | |
8064 | ||
5d6a16e2 MH |
8065 | /* Search the nodes of the CFG in reverse completion order |
8066 | so that we can find outer loops first. */ | |
c34d5374 | 8067 | header = BASIC_BLOCK (rc_order[b]); |
c9bacfdb | 8068 | |
4dc9341c MH |
8069 | /* Look for all the possible latch blocks for this header. */ |
8070 | for (e = header->pred; e; e = e->pred_next) | |
8071 | { | |
8072 | basic_block latch = e->src; | |
c9bacfdb | 8073 | |
4dc9341c MH |
8074 | /* Look for back edges where a predecessor is dominated |
8075 | by this block. A natural loop has a single entry | |
8076 | node (header) that dominates all the nodes in the | |
8077 | loop. It also has single back edge to the header | |
8078 | from a latch node. Note that multiple natural loops | |
8079 | may share the same header. */ | |
8080 | if (latch != ENTRY_BLOCK_PTR | |
8081 | && TEST_BIT (dom[latch->index], header->index)) | |
8082 | { | |
8083 | struct loop *loop; | |
c9bacfdb | 8084 | |
4dc9341c | 8085 | loop = loops->array + num_loops; |
c9bacfdb | 8086 | |
4dc9341c MH |
8087 | loop->header = header; |
8088 | loop->latch = latch; | |
c34d5374 | 8089 | loop->num = num_loops; |
c9bacfdb | 8090 | |
4dc9341c MH |
8091 | num_loops++; |
8092 | } | |
8093 | } | |
8094 | } | |
c9bacfdb | 8095 | |
5d6a16e2 MH |
8096 | for (i = 0; i < num_loops; i++) |
8097 | { | |
8098 | struct loop *loop = &loops->array[i]; | |
8099 | int j; | |
8100 | ||
8101 | /* Keep track of blocks that are loop headers so | |
8102 | that we can tell which loops should be merged. */ | |
8103 | if (TEST_BIT (headers, loop->header->index)) | |
8104 | SET_BIT (loops->shared_headers, loop->header->index); | |
8105 | SET_BIT (headers, loop->header->index); | |
8106 | ||
8107 | /* Find nodes contained within the loop. */ | |
8108 | loop->nodes = sbitmap_alloc (n_basic_blocks); | |
8109 | loop->num_nodes | |
8110 | = flow_loop_nodes_find (loop->header, loop->latch, loop->nodes); | |
8111 | ||
8112 | /* Compute first and last blocks within the loop. | |
8113 | These are often the same as the loop header and | |
8114 | loop latch respectively, but this is not always | |
8115 | the case. */ | |
8116 | loop->first | |
8117 | = BASIC_BLOCK (sbitmap_first_set_bit (loop->nodes)); | |
8118 | loop->last | |
8119 | = BASIC_BLOCK (sbitmap_last_set_bit (loop->nodes)); | |
8120 | ||
8121 | if (flags & LOOP_EDGES) | |
8122 | { | |
8123 | /* Find edges which enter the loop header. | |
8124 | Note that the entry edges should only | |
8125 | enter the header of a natural loop. */ | |
8126 | loop->num_entries | |
8127 | = flow_loop_entry_edges_find (loop->header, | |
8128 | loop->nodes, | |
8129 | &loop->entry_edges); | |
8130 | ||
8131 | /* Find edges which exit the loop. */ | |
8132 | loop->num_exits | |
8133 | = flow_loop_exit_edges_find (loop->nodes, | |
8134 | &loop->exit_edges); | |
8135 | ||
8136 | /* Determine which loop nodes dominate all the exits | |
8137 | of the loop. */ | |
8138 | loop->exits_doms = sbitmap_alloc (n_basic_blocks); | |
8139 | sbitmap_copy (loop->exits_doms, loop->nodes); | |
8140 | for (j = 0; j < loop->num_exits; j++) | |
8141 | sbitmap_a_and_b (loop->exits_doms, loop->exits_doms, | |
8142 | dom[loop->exit_edges[j]->src->index]); | |
8143 | ||
8144 | /* The header of a natural loop must dominate | |
8145 | all exits. */ | |
8146 | if (! TEST_BIT (loop->exits_doms, loop->header->index)) | |
8147 | abort (); | |
8148 | } | |
8149 | ||
8150 | if (flags & LOOP_PRE_HEADER) | |
8151 | { | |
8152 | /* Look to see if the loop has a pre-header node. */ | |
8153 | loop->pre_header | |
8154 | = flow_loop_pre_header_find (loop->header, dom); | |
8155 | ||
8156 | flow_loop_pre_header_scan (loop); | |
8157 | } | |
8158 | } | |
8159 | ||
4dc9341c MH |
8160 | /* Natural loops with shared headers may either be disjoint or |
8161 | nested. Disjoint loops with shared headers cannot be inner | |
8162 | loops and should be merged. For now just mark loops that share | |
8163 | headers. */ | |
8164 | for (i = 0; i < num_loops; i++) | |
8165 | if (TEST_BIT (loops->shared_headers, loops->array[i].header->index)) | |
8166 | loops->array[i].shared = 1; | |
8167 | ||
8168 | sbitmap_free (headers); | |
8169 | } | |
8170 | ||
8171 | loops->num = num_loops; | |
8172 | ||
8173 | /* Save CFG derived information to avoid recomputing it. */ | |
8174 | loops->cfg.dom = dom; | |
8175 | loops->cfg.dfs_order = dfs_order; | |
c34d5374 | 8176 | loops->cfg.rc_order = rc_order; |
4dc9341c MH |
8177 | |
8178 | /* Build the loop hierarchy tree. */ | |
8179 | flow_loops_tree_build (loops); | |
8180 | ||
8181 | /* Assign the loop nesting depth and enclosed loop level for each | |
8182 | loop. */ | |
d6181b1b | 8183 | loops->levels = flow_loops_level_compute (loops); |
4dc9341c MH |
8184 | |
8185 | return num_loops; | |
8186 | } | |
8187 | ||
5d6a16e2 MH |
8188 | |
8189 | /* Update the information regarding the loops in the CFG | |
8190 | specified by LOOPS. */ | |
8191 | int | |
8192 | flow_loops_update (loops, flags) | |
8193 | struct loops *loops; | |
8194 | int flags; | |
8195 | { | |
8196 | /* One day we may want to update the current loop data. For now | |
8197 | throw away the old stuff and rebuild what we need. */ | |
8198 | if (loops->array) | |
8199 | flow_loops_free (loops); | |
8200 | ||
8201 | return flow_loops_find (loops, flags); | |
8202 | } | |
8203 | ||
8204 | ||
4dc9341c | 8205 | /* Return non-zero if edge E enters header of LOOP from outside of LOOP. */ |
efc9bd41 | 8206 | |
4dc9341c MH |
8207 | int |
8208 | flow_loop_outside_edge_p (loop, e) | |
8209 | const struct loop *loop; | |
8210 | edge e; | |
8211 | { | |
8212 | if (e->dest != loop->header) | |
8213 | abort (); | |
8214 | return (e->src == ENTRY_BLOCK_PTR) | |
8215 | || ! TEST_BIT (loop->nodes, e->src->index); | |
8216 | } | |
11bdd2ae | 8217 | |
c9bacfdb | 8218 | /* Clear LOG_LINKS fields of insns in a chain. |
1868b439 GK |
8219 | Also clear the global_live_at_{start,end} fields of the basic block |
8220 | structures. */ | |
efc9bd41 | 8221 | |
d9d4fb43 AS |
8222 | void |
8223 | clear_log_links (insns) | |
8224 | rtx insns; | |
8225 | { | |
8226 | rtx i; | |
1868b439 GK |
8227 | int b; |
8228 | ||
d9d4fb43 | 8229 | for (i = insns; i; i = NEXT_INSN (i)) |
2c3c49de | 8230 | if (INSN_P (i)) |
d9d4fb43 | 8231 | LOG_LINKS (i) = 0; |
1868b439 GK |
8232 | |
8233 | for (b = 0; b < n_basic_blocks; b++) | |
8234 | { | |
da92f7ff | 8235 | basic_block bb = BASIC_BLOCK (b); |
1868b439 GK |
8236 | |
8237 | bb->global_live_at_start = NULL; | |
8238 | bb->global_live_at_end = NULL; | |
8239 | } | |
8240 | ||
8241 | ENTRY_BLOCK_PTR->global_live_at_end = NULL; | |
8242 | EXIT_BLOCK_PTR->global_live_at_start = NULL; | |
d9d4fb43 | 8243 | } |
efc9bd41 RK |
8244 | |
8245 | /* Given a register bitmap, turn on the bits in a HARD_REG_SET that | |
8246 | correspond to the hard registers, if any, set in that map. This | |
8247 | could be done far more efficiently by having all sorts of special-cases | |
8248 | with moving single words, but probably isn't worth the trouble. */ | |
8249 | ||
8250 | void | |
8251 | reg_set_to_hard_reg_set (to, from) | |
8252 | HARD_REG_SET *to; | |
8253 | bitmap from; | |
8254 | { | |
8255 | int i; | |
8256 | ||
8257 | EXECUTE_IF_SET_IN_BITMAP | |
8258 | (from, 0, i, | |
8259 | { | |
8260 | if (i >= FIRST_PSEUDO_REGISTER) | |
8261 | return; | |
8262 | SET_HARD_REG_BIT (*to, i); | |
8263 | }); | |
8264 | } | |
1f8f4a0b MM |
8265 | |
8266 | /* Called once at intialization time. */ | |
8267 | ||
8268 | void | |
8269 | init_flow () | |
8270 | { | |
8271 | static int initialized; | |
8272 | ||
8273 | if (!initialized) | |
8274 | { | |
8275 | gcc_obstack_init (&flow_obstack); | |
8276 | flow_firstobj = (char *) obstack_alloc (&flow_obstack, 0); | |
8277 | initialized = 1; | |
8278 | } | |
8279 | else | |
8280 | { | |
8281 | obstack_free (&flow_obstack, flow_firstobj); | |
8282 | flow_firstobj = (char *) obstack_alloc (&flow_obstack, 0); | |
8283 | } | |
8284 | } |