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d7429b6a | 1 | /* Data flow analysis for GNU compiler. |
3b708058 JL |
2 | Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, |
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 RK |
21 | |
22 | ||
e881bb1b RH |
23 | /* This file contains the data flow analysis pass of the compiler. It |
24 | computes data flow information which tells combine_instructions | |
25 | which insns to consider combining and controls register allocation. | |
d7429b6a | 26 | |
e881bb1b RH |
27 | Additional data flow information that is too bulky to record is |
28 | generated during the analysis, and is used at that time to create | |
29 | autoincrement and autodecrement addressing. | |
d7429b6a RK |
30 | |
31 | The first step is dividing the function into basic blocks. | |
32 | find_basic_blocks does this. Then life_analysis determines | |
33 | where each register is live and where it is dead. | |
34 | ||
35 | ** find_basic_blocks ** | |
36 | ||
e881bb1b RH |
37 | find_basic_blocks divides the current function's rtl into basic |
38 | blocks and constructs the CFG. The blocks are recorded in the | |
39 | basic_block_info array; the CFG exists in the edge structures | |
40 | referenced by the blocks. | |
d7429b6a | 41 | |
e881bb1b | 42 | find_basic_blocks also finds any unreachable loops and deletes them. |
d7429b6a RK |
43 | |
44 | ** life_analysis ** | |
45 | ||
46 | life_analysis is called immediately after find_basic_blocks. | |
47 | It uses the basic block information to determine where each | |
48 | hard or pseudo register is live. | |
49 | ||
50 | ** live-register info ** | |
51 | ||
52 | The information about where each register is live is in two parts: | |
e881bb1b | 53 | the REG_NOTES of insns, and the vector basic_block->global_live_at_start. |
d7429b6a | 54 | |
e881bb1b RH |
55 | basic_block->global_live_at_start has an element for each basic |
56 | block, and the element is a bit-vector with a bit for each hard or | |
57 | pseudo register. The bit is 1 if the register is live at the | |
58 | beginning of the basic block. | |
d7429b6a RK |
59 | |
60 | Two types of elements can be added to an insn's REG_NOTES. | |
61 | A REG_DEAD note is added to an insn's REG_NOTES for any register | |
62 | that meets both of two conditions: The value in the register is not | |
63 | needed in subsequent insns and the insn does not replace the value in | |
64 | the register (in the case of multi-word hard registers, the value in | |
65 | each register must be replaced by the insn to avoid a REG_DEAD note). | |
66 | ||
67 | In the vast majority of cases, an object in a REG_DEAD note will be | |
68 | used somewhere in the insn. The (rare) exception to this is if an | |
69 | insn uses a multi-word hard register and only some of the registers are | |
70 | needed in subsequent insns. In that case, REG_DEAD notes will be | |
71 | provided for those hard registers that are not subsequently needed. | |
72 | Partial REG_DEAD notes of this type do not occur when an insn sets | |
73 | only some of the hard registers used in such a multi-word operand; | |
74 | omitting REG_DEAD notes for objects stored in an insn is optional and | |
75 | the desire to do so does not justify the complexity of the partial | |
76 | REG_DEAD notes. | |
77 | ||
78 | REG_UNUSED notes are added for each register that is set by the insn | |
79 | but is unused subsequently (if every register set by the insn is unused | |
80 | and the insn does not reference memory or have some other side-effect, | |
81 | the insn is deleted instead). If only part of a multi-word hard | |
82 | register is used in a subsequent insn, REG_UNUSED notes are made for | |
83 | the parts that will not be used. | |
84 | ||
85 | To determine which registers are live after any insn, one can | |
86 | start from the beginning of the basic block and scan insns, noting | |
87 | which registers are set by each insn and which die there. | |
88 | ||
89 | ** Other actions of life_analysis ** | |
90 | ||
91 | life_analysis sets up the LOG_LINKS fields of insns because the | |
92 | information needed to do so is readily available. | |
93 | ||
94 | life_analysis deletes insns whose only effect is to store a value | |
95 | that is never used. | |
96 | ||
97 | life_analysis notices cases where a reference to a register as | |
98 | a memory address can be combined with a preceding or following | |
99 | incrementation or decrementation of the register. The separate | |
100 | instruction to increment or decrement is deleted and the address | |
101 | is changed to a POST_INC or similar rtx. | |
102 | ||
103 | Each time an incrementing or decrementing address is created, | |
104 | a REG_INC element is added to the insn's REG_NOTES list. | |
105 | ||
106 | life_analysis fills in certain vectors containing information about | |
d4b60170 RK |
107 | register usage: REG_N_REFS, REG_N_DEATHS, REG_N_SETS, REG_LIVE_LENGTH, |
108 | REG_N_CALLS_CROSSED and REG_BASIC_BLOCK. | |
fdb8a883 JW |
109 | |
110 | life_analysis sets current_function_sp_is_unchanging if the function | |
111 | doesn't modify the stack pointer. */ | |
e881bb1b RH |
112 | |
113 | /* TODO: | |
114 | ||
115 | Split out from life_analysis: | |
116 | - local property discovery (bb->local_live, bb->local_set) | |
117 | - global property computation | |
118 | - log links creation | |
119 | - pre/post modify transformation | |
120 | */ | |
d7429b6a | 121 | \f |
d7429b6a | 122 | #include "config.h" |
670ee920 | 123 | #include "system.h" |
d3a923ee | 124 | #include "tree.h" |
d7429b6a | 125 | #include "rtl.h" |
6baf1cc8 | 126 | #include "tm_p.h" |
d7429b6a RK |
127 | #include "basic-block.h" |
128 | #include "insn-config.h" | |
129 | #include "regs.h" | |
130 | #include "hard-reg-set.h" | |
131 | #include "flags.h" | |
132 | #include "output.h" | |
b384405b | 133 | #include "function.h" |
3d195391 | 134 | #include "except.h" |
2e107e9e | 135 | #include "toplev.h" |
79c9824e | 136 | #include "recog.h" |
e881bb1b | 137 | #include "insn-flags.h" |
11bdd2ae | 138 | #include "expr.h" |
d7429b6a RK |
139 | |
140 | #include "obstack.h" | |
c5c76735 | 141 | |
d7429b6a RK |
142 | #define obstack_chunk_alloc xmalloc |
143 | #define obstack_chunk_free free | |
144 | ||
e881bb1b RH |
145 | |
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 | |
7eb136d6 MM |
164 | /* The contents of the current function definition are allocated |
165 | in this obstack, and all are freed at the end of the function. | |
166 | For top-level functions, this is temporary_obstack. | |
167 | Separate obstacks are made for nested functions. */ | |
168 | ||
169 | extern struct obstack *function_obstack; | |
170 | ||
e881bb1b | 171 | /* Number of basic blocks in the current function. */ |
d7429b6a | 172 | |
e881bb1b | 173 | int n_basic_blocks; |
d7429b6a | 174 | |
d3a923ee RH |
175 | /* Number of edges in the current function. */ |
176 | ||
177 | int n_edges; | |
178 | ||
e881bb1b | 179 | /* The basic block array. */ |
d7429b6a | 180 | |
e881bb1b | 181 | varray_type basic_block_info; |
d7429b6a | 182 | |
e881bb1b | 183 | /* The special entry and exit blocks. */ |
d7429b6a | 184 | |
d4b60170 RK |
185 | struct basic_block_def entry_exit_blocks[2] |
186 | = {{NULL, /* head */ | |
e881bb1b RH |
187 | NULL, /* end */ |
188 | NULL, /* pred */ | |
189 | NULL, /* succ */ | |
190 | NULL, /* local_set */ | |
191 | NULL, /* global_live_at_start */ | |
192 | NULL, /* global_live_at_end */ | |
193 | NULL, /* aux */ | |
194 | ENTRY_BLOCK, /* index */ | |
336a6399 RH |
195 | 0, /* loop_depth */ |
196 | -1, -1 /* eh_beg, eh_end */ | |
e881bb1b RH |
197 | }, |
198 | { | |
199 | NULL, /* head */ | |
200 | NULL, /* end */ | |
201 | NULL, /* pred */ | |
202 | NULL, /* succ */ | |
203 | NULL, /* local_set */ | |
204 | NULL, /* global_live_at_start */ | |
205 | NULL, /* global_live_at_end */ | |
206 | NULL, /* aux */ | |
207 | EXIT_BLOCK, /* index */ | |
336a6399 RH |
208 | 0, /* loop_depth */ |
209 | -1, -1 /* eh_beg, eh_end */ | |
e881bb1b RH |
210 | } |
211 | }; | |
d7429b6a | 212 | |
56744d1a JL |
213 | /* Nonzero if the second flow pass has completed. */ |
214 | int flow2_completed; | |
215 | ||
d7429b6a RK |
216 | /* Maximum register number used in this function, plus one. */ |
217 | ||
218 | int max_regno; | |
219 | ||
b1f21e0a | 220 | /* Indexed by n, giving various register information */ |
d7429b6a | 221 | |
6feacd09 | 222 | varray_type reg_n_info; |
d7429b6a | 223 | |
a494747c MM |
224 | /* Size of the reg_n_info table. */ |
225 | ||
226 | unsigned int reg_n_max; | |
227 | ||
d7429b6a RK |
228 | /* Element N is the next insn that uses (hard or pseudo) register number N |
229 | within the current basic block; or zero, if there is no such insn. | |
230 | This is valid only during the final backward scan in propagate_block. */ | |
231 | ||
232 | static rtx *reg_next_use; | |
233 | ||
234 | /* Size of a regset for the current function, | |
235 | in (1) bytes and (2) elements. */ | |
236 | ||
237 | int regset_bytes; | |
238 | int regset_size; | |
239 | ||
d7429b6a | 240 | /* Regset of regs live when calls to `setjmp'-like functions happen. */ |
e881bb1b | 241 | /* ??? Does this exist only for the setjmp-clobbered warning message? */ |
d7429b6a RK |
242 | |
243 | regset regs_live_at_setjmp; | |
244 | ||
245 | /* List made of EXPR_LIST rtx's which gives pairs of pseudo registers | |
246 | that have to go in the same hard reg. | |
247 | The first two regs in the list are a pair, and the next two | |
248 | are another pair, etc. */ | |
249 | rtx regs_may_share; | |
250 | ||
d7429b6a RK |
251 | /* Depth within loops of basic block being scanned for lifetime analysis, |
252 | plus one. This is the weight attached to references to registers. */ | |
253 | ||
254 | static int loop_depth; | |
255 | ||
256 | /* During propagate_block, this is non-zero if the value of CC0 is live. */ | |
257 | ||
258 | static int cc0_live; | |
259 | ||
db3a887b | 260 | /* During propagate_block, this contains a list of all the MEMs we are |
ff666313 | 261 | tracking for dead store elimination. */ |
d7429b6a | 262 | |
db3a887b | 263 | static rtx mem_set_list; |
d7429b6a RK |
264 | |
265 | /* Set of registers that may be eliminable. These are handled specially | |
266 | in updating regs_ever_live. */ | |
267 | ||
268 | static HARD_REG_SET elim_reg_set; | |
269 | ||
e881bb1b RH |
270 | /* The basic block structure for every insn, indexed by uid. */ |
271 | ||
272 | varray_type basic_block_for_insn; | |
273 | ||
274 | /* The labels mentioned in non-jump rtl. Valid during find_basic_blocks. */ | |
275 | /* ??? Should probably be using LABEL_NUSES instead. It would take a | |
276 | bit of surgery to be able to use or co-opt the routines in jump. */ | |
277 | ||
278 | static rtx label_value_list; | |
279 | ||
d7429b6a | 280 | /* Forward declarations */ |
711d877c KG |
281 | static int count_basic_blocks PARAMS ((rtx)); |
282 | static rtx find_basic_blocks_1 PARAMS ((rtx)); | |
711d877c KG |
283 | static void clear_edges PARAMS ((void)); |
284 | static void make_edges PARAMS ((rtx)); | |
711d877c KG |
285 | static void make_label_edge PARAMS ((sbitmap *, basic_block, |
286 | rtx, int)); | |
287 | static void make_eh_edge PARAMS ((sbitmap *, eh_nesting_info *, | |
288 | basic_block, rtx, int)); | |
289 | static void mark_critical_edges PARAMS ((void)); | |
290 | static void move_stray_eh_region_notes PARAMS ((void)); | |
291 | static void record_active_eh_regions PARAMS ((rtx)); | |
292 | ||
293 | static void commit_one_edge_insertion PARAMS ((edge)); | |
294 | ||
295 | static void delete_unreachable_blocks PARAMS ((void)); | |
296 | static void delete_eh_regions PARAMS ((void)); | |
297 | static int can_delete_note_p PARAMS ((rtx)); | |
298 | static int delete_block PARAMS ((basic_block)); | |
299 | static void expunge_block PARAMS ((basic_block)); | |
711d877c KG |
300 | static int can_delete_label_p PARAMS ((rtx)); |
301 | static int merge_blocks_move_predecessor_nojumps PARAMS ((basic_block, | |
302 | basic_block)); | |
303 | static int merge_blocks_move_successor_nojumps PARAMS ((basic_block, | |
336a6399 | 304 | basic_block)); |
711d877c KG |
305 | static void merge_blocks_nomove PARAMS ((basic_block, basic_block)); |
306 | static int merge_blocks PARAMS ((edge,basic_block,basic_block)); | |
307 | static void try_merge_blocks PARAMS ((void)); | |
308 | static void tidy_fallthru_edge PARAMS ((edge,basic_block,basic_block)); | |
5568fb48 | 309 | static void tidy_fallthru_edges PARAMS ((void)); |
711d877c KG |
310 | static int verify_wide_reg_1 PARAMS ((rtx *, void *)); |
311 | static void verify_wide_reg PARAMS ((int, rtx, rtx)); | |
312 | static void verify_local_live_at_start PARAMS ((regset, basic_block)); | |
313 | static int set_noop_p PARAMS ((rtx)); | |
314 | static int noop_move_p PARAMS ((rtx)); | |
3ea8083f JL |
315 | static void delete_noop_moves PARAMS ((rtx)); |
316 | static void notice_stack_pointer_modification_1 PARAMS ((rtx, rtx, void *)); | |
317 | static void notice_stack_pointer_modification PARAMS ((rtx)); | |
c13fde05 | 318 | static void mark_reg PARAMS ((rtx, void *)); |
711d877c | 319 | static void mark_regs_live_at_end PARAMS ((regset)); |
4e872036 | 320 | static int set_phi_alternative_reg PARAMS ((rtx, int, int, void *)); |
711d877c | 321 | static void calculate_global_regs_live PARAMS ((sbitmap, sbitmap, int)); |
65f6fa24 RH |
322 | static void propagate_block PARAMS ((basic_block, regset, |
323 | regset, int)); | |
711d877c KG |
324 | static int insn_dead_p PARAMS ((rtx, regset, int, rtx)); |
325 | static int libcall_dead_p PARAMS ((rtx, regset, rtx, rtx)); | |
326 | static void mark_set_regs PARAMS ((regset, regset, rtx, | |
327 | rtx, regset, int)); | |
328 | static void mark_set_1 PARAMS ((regset, regset, rtx, | |
329 | rtx, regset, int)); | |
1d300e19 | 330 | #ifdef AUTO_INC_DEC |
711d877c KG |
331 | static void find_auto_inc PARAMS ((regset, rtx, rtx)); |
332 | static int try_pre_increment_1 PARAMS ((rtx)); | |
333 | static int try_pre_increment PARAMS ((rtx, rtx, HOST_WIDE_INT)); | |
1d300e19 | 334 | #endif |
711d877c KG |
335 | static void mark_used_regs PARAMS ((regset, regset, rtx, int, rtx)); |
336 | void dump_flow_info PARAMS ((FILE *)); | |
337 | void debug_flow_info PARAMS ((void)); | |
338 | static void dump_edge_info PARAMS ((FILE *, edge, int)); | |
339 | ||
340 | static void count_reg_sets_1 PARAMS ((rtx)); | |
341 | static void count_reg_sets PARAMS ((rtx)); | |
342 | static void count_reg_references PARAMS ((rtx)); | |
343 | static void invalidate_mems_from_autoinc PARAMS ((rtx)); | |
711d877c KG |
344 | static void remove_fake_successors PARAMS ((basic_block)); |
345 | static void flow_nodes_print PARAMS ((const char *, const sbitmap, FILE *)); | |
346 | static void flow_exits_print PARAMS ((const char *, const edge *, int, FILE *)); | |
347 | static void flow_loops_cfg_dump PARAMS ((const struct loops *, FILE *)); | |
348 | static int flow_loop_nested_p PARAMS ((struct loop *, struct loop *)); | |
349 | static int flow_loop_exits_find PARAMS ((const sbitmap, edge **)); | |
350 | static int flow_loop_nodes_find PARAMS ((basic_block, basic_block, sbitmap)); | |
351 | static int flow_depth_first_order_compute PARAMS ((int *)); | |
352 | static basic_block flow_loop_pre_header_find PARAMS ((basic_block, const sbitmap *)); | |
353 | static void flow_loop_tree_node_add PARAMS ((struct loop *, struct loop *)); | |
354 | static void flow_loops_tree_build PARAMS ((struct loops *)); | |
355 | static int flow_loop_level_compute PARAMS ((struct loop *, int)); | |
356 | static int flow_loops_level_compute PARAMS ((struct loops *)); | |
d7429b6a | 357 | \f |
5ece9746 | 358 | /* Find basic blocks of the current function. |
e881bb1b RH |
359 | F is the first insn of the function and NREGS the number of register |
360 | numbers in use. */ | |
d7429b6a RK |
361 | |
362 | void | |
19d3c25c | 363 | find_basic_blocks (f, nregs, file) |
d7429b6a | 364 | rtx f; |
e881bb1b RH |
365 | int nregs ATTRIBUTE_UNUSED; |
366 | FILE *file ATTRIBUTE_UNUSED; | |
d7429b6a | 367 | { |
e881bb1b | 368 | int max_uid; |
d7429b6a | 369 | |
e881bb1b RH |
370 | /* Flush out existing data. */ |
371 | if (basic_block_info != NULL) | |
372 | { | |
373 | int i; | |
421382ac | 374 | |
e881bb1b | 375 | clear_edges (); |
d7429b6a | 376 | |
e881bb1b RH |
377 | /* Clear bb->aux on all extant basic blocks. We'll use this as a |
378 | tag for reuse during create_basic_block, just in case some pass | |
379 | copies around basic block notes improperly. */ | |
380 | for (i = 0; i < n_basic_blocks; ++i) | |
381 | BASIC_BLOCK (i)->aux = NULL; | |
d7429b6a | 382 | |
e881bb1b RH |
383 | VARRAY_FREE (basic_block_info); |
384 | } | |
27249135 | 385 | |
e881bb1b | 386 | n_basic_blocks = count_basic_blocks (f); |
27249135 | 387 | |
e881bb1b RH |
388 | /* Size the basic block table. The actual structures will be allocated |
389 | by find_basic_blocks_1, since we want to keep the structure pointers | |
390 | stable across calls to find_basic_blocks. */ | |
391 | /* ??? This whole issue would be much simpler if we called find_basic_blocks | |
392 | exactly once, and thereafter we don't have a single long chain of | |
393 | instructions at all until close to the end of compilation when we | |
394 | actually lay them out. */ | |
8cfe18d6 | 395 | |
e881bb1b RH |
396 | VARRAY_BB_INIT (basic_block_info, n_basic_blocks, "basic_block_info"); |
397 | ||
336a6399 | 398 | label_value_list = find_basic_blocks_1 (f); |
088e7160 | 399 | |
e881bb1b RH |
400 | /* Record the block to which an insn belongs. */ |
401 | /* ??? This should be done another way, by which (perhaps) a label is | |
402 | tagged directly with the basic block that it starts. It is used for | |
403 | more than that currently, but IMO that is the only valid use. */ | |
404 | ||
405 | max_uid = get_max_uid (); | |
d7429b6a | 406 | #ifdef AUTO_INC_DEC |
5ece9746 JL |
407 | /* Leave space for insns life_analysis makes in some cases for auto-inc. |
408 | These cases are rare, so we don't need too much space. */ | |
e881bb1b | 409 | max_uid += max_uid / 10; |
d7429b6a RK |
410 | #endif |
411 | ||
2307e372 | 412 | compute_bb_for_insn (max_uid); |
e881bb1b RH |
413 | |
414 | /* Discover the edges of our cfg. */ | |
336a6399 RH |
415 | record_active_eh_regions (f); |
416 | make_edges (label_value_list); | |
5568fb48 RH |
417 | |
418 | /* Do very simple cleanup now, for the benefit of code that runs between | |
419 | here and cleanup_cfg, e.g. thread_prologue_and_epilogue_insns. */ | |
420 | tidy_fallthru_edges (); | |
421 | ||
e881bb1b RH |
422 | mark_critical_edges (); |
423 | ||
34487bf8 RH |
424 | #ifdef ENABLE_CHECKING |
425 | verify_flow_info (); | |
426 | #endif | |
d7429b6a | 427 | } |
5ece9746 | 428 | |
e881bb1b | 429 | /* Count the basic blocks of the function. */ |
dc2ede84 | 430 | |
e881bb1b RH |
431 | static int |
432 | count_basic_blocks (f) | |
433 | rtx f; | |
434 | { | |
435 | register rtx insn; | |
436 | register RTX_CODE prev_code; | |
437 | register int count = 0; | |
438 | int eh_region = 0; | |
e881bb1b RH |
439 | int call_had_abnormal_edge = 0; |
440 | rtx prev_call = NULL_RTX; | |
dc2ede84 | 441 | |
e881bb1b RH |
442 | prev_code = JUMP_INSN; |
443 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
444 | { | |
445 | register RTX_CODE code = GET_CODE (insn); | |
446 | ||
e881bb1b RH |
447 | if (code == CODE_LABEL |
448 | || (GET_RTX_CLASS (code) == 'i' | |
449 | && (prev_code == JUMP_INSN | |
450 | || prev_code == BARRIER | |
451 | || (prev_code == CALL_INSN && call_had_abnormal_edge)))) | |
452 | { | |
453 | count++; | |
e881bb1b | 454 | } |
dc2ede84 | 455 | |
e881bb1b RH |
456 | /* Record whether this call created an edge. */ |
457 | if (code == CALL_INSN) | |
458 | { | |
6af57aae | 459 | rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); |
8ad52449 | 460 | int region = (note ? INTVAL (XEXP (note, 0)) : 1); |
e881bb1b RH |
461 | prev_call = insn; |
462 | call_had_abnormal_edge = 0; | |
6af57aae | 463 | |
6814a8a0 JM |
464 | /* If there is an EH region or rethrow, we have an edge. */ |
465 | if ((eh_region && region > 0) | |
466 | || find_reg_note (insn, REG_EH_RETHROW, NULL_RTX)) | |
6af57aae AM |
467 | call_had_abnormal_edge = 1; |
468 | else | |
e881bb1b | 469 | { |
6af57aae AM |
470 | /* If there is a nonlocal goto label and the specified |
471 | region number isn't -1, we have an edge. (0 means | |
472 | no throw, but might have a nonlocal goto). */ | |
473 | if (nonlocal_goto_handler_labels && region >= 0) | |
e881bb1b RH |
474 | call_had_abnormal_edge = 1; |
475 | } | |
476 | } | |
477 | else if (code != NOTE) | |
478 | prev_call = NULL_RTX; | |
479 | ||
480 | if (code != NOTE) | |
481 | prev_code = code; | |
482 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG) | |
483 | ++eh_region; | |
484 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END) | |
485 | --eh_region; | |
486 | ||
e881bb1b RH |
487 | } |
488 | ||
489 | /* The rest of the compiler works a bit smoother when we don't have to | |
490 | check for the edge case of do-nothing functions with no basic blocks. */ | |
491 | if (count == 0) | |
492 | { | |
493 | emit_insn (gen_rtx_USE (VOIDmode, const0_rtx)); | |
494 | count = 1; | |
495 | } | |
496 | ||
497 | return count; | |
498 | } | |
dc2ede84 | 499 | |
d7429b6a | 500 | /* Find all basic blocks of the function whose first insn is F. |
d7429b6a | 501 | |
336a6399 RH |
502 | Collect and return a list of labels whose addresses are taken. This |
503 | will be used in make_edges for use with computed gotos. */ | |
8329b5ec | 504 | |
e881bb1b | 505 | static rtx |
336a6399 | 506 | find_basic_blocks_1 (f) |
e881bb1b | 507 | rtx f; |
e881bb1b RH |
508 | { |
509 | register rtx insn, next; | |
e881bb1b RH |
510 | int call_has_abnormal_edge = 0; |
511 | int i = 0; | |
512 | rtx bb_note = NULL_RTX; | |
513 | rtx eh_list = NULL_RTX; | |
514 | rtx label_value_list = NULL_RTX; | |
515 | rtx head = NULL_RTX; | |
516 | rtx end = NULL_RTX; | |
517 | ||
518 | /* We process the instructions in a slightly different way than we did | |
519 | previously. This is so that we see a NOTE_BASIC_BLOCK after we have | |
520 | closed out the previous block, so that it gets attached at the proper | |
521 | place. Since this form should be equivalent to the previous, | |
336a6399 | 522 | count_basic_blocks continues to use the old form as a check. */ |
d7429b6a | 523 | |
e881bb1b RH |
524 | for (insn = f; insn; insn = next) |
525 | { | |
526 | enum rtx_code code = GET_CODE (insn); | |
d7429b6a | 527 | |
e881bb1b | 528 | next = NEXT_INSN (insn); |
d7429b6a | 529 | |
e881bb1b | 530 | if (code == CALL_INSN) |
e658434c | 531 | { |
e881bb1b | 532 | /* Record whether this call created an edge. */ |
6af57aae | 533 | rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); |
8ad52449 | 534 | int region = (note ? INTVAL (XEXP (note, 0)) : 1); |
e881bb1b | 535 | call_has_abnormal_edge = 0; |
6af57aae | 536 | |
6814a8a0 JM |
537 | /* If there is an EH region or rethrow, we have an edge. */ |
538 | if ((eh_list && region > 0) | |
539 | || find_reg_note (insn, REG_EH_RETHROW, NULL_RTX)) | |
6af57aae AM |
540 | call_has_abnormal_edge = 1; |
541 | else | |
e658434c | 542 | { |
6af57aae AM |
543 | /* If there is a nonlocal goto label and the specified |
544 | region number isn't -1, we have an edge. (0 means | |
545 | no throw, but might have a nonlocal goto). */ | |
546 | if (nonlocal_goto_handler_labels && region >= 0) | |
e881bb1b | 547 | call_has_abnormal_edge = 1; |
5c35539b | 548 | } |
e658434c | 549 | } |
d7429b6a | 550 | |
e881bb1b | 551 | switch (code) |
e658434c | 552 | { |
e881bb1b RH |
553 | case NOTE: |
554 | { | |
555 | int kind = NOTE_LINE_NUMBER (insn); | |
556 | ||
557 | /* Keep a LIFO list of the currently active exception notes. */ | |
558 | if (kind == NOTE_INSN_EH_REGION_BEG) | |
336a6399 | 559 | eh_list = alloc_INSN_LIST (insn, eh_list); |
e881bb1b | 560 | else if (kind == NOTE_INSN_EH_REGION_END) |
336a6399 RH |
561 | { |
562 | rtx t = eh_list; | |
563 | eh_list = XEXP (eh_list, 1); | |
564 | free_INSN_LIST_node (t); | |
565 | } | |
e881bb1b RH |
566 | |
567 | /* Look for basic block notes with which to keep the | |
568 | basic_block_info pointers stable. Unthread the note now; | |
569 | we'll put it back at the right place in create_basic_block. | |
570 | Or not at all if we've already found a note in this block. */ | |
571 | else if (kind == NOTE_INSN_BASIC_BLOCK) | |
572 | { | |
573 | if (bb_note == NULL_RTX) | |
574 | bb_note = insn; | |
575 | next = flow_delete_insn (insn); | |
576 | } | |
e658434c | 577 | |
e881bb1b RH |
578 | break; |
579 | } | |
d7429b6a | 580 | |
e881bb1b RH |
581 | case CODE_LABEL: |
582 | /* A basic block starts at a label. If we've closed one off due | |
583 | to a barrier or some such, no need to do it again. */ | |
584 | if (head != NULL_RTX) | |
2ec1535d | 585 | { |
e881bb1b RH |
586 | /* While we now have edge lists with which other portions of |
587 | the compiler might determine a call ending a basic block | |
588 | does not imply an abnormal edge, it will be a bit before | |
589 | everything can be updated. So continue to emit a noop at | |
590 | the end of such a block. */ | |
0a1c58a2 JL |
591 | if (GET_CODE (end) == CALL_INSN |
592 | && ! SIBLING_CALL_P (end)) | |
e881bb1b RH |
593 | { |
594 | rtx nop = gen_rtx_USE (VOIDmode, const0_rtx); | |
595 | end = emit_insn_after (nop, end); | |
596 | } | |
597 | ||
e881bb1b RH |
598 | create_basic_block (i++, head, end, bb_note); |
599 | bb_note = NULL_RTX; | |
2ec1535d | 600 | } |
e881bb1b RH |
601 | head = end = insn; |
602 | break; | |
d06c6389 | 603 | |
e881bb1b RH |
604 | case JUMP_INSN: |
605 | /* A basic block ends at a jump. */ | |
606 | if (head == NULL_RTX) | |
607 | head = insn; | |
608 | else | |
609 | { | |
610 | /* ??? Make a special check for table jumps. The way this | |
7a3b7acb | 611 | happens is truly and amazingly gross. We are about to |
e881bb1b RH |
612 | create a basic block that contains just a code label and |
613 | an addr*vec jump insn. Worse, an addr_diff_vec creates | |
614 | its own natural loop. | |
5c35539b | 615 | |
e881bb1b RH |
616 | Prevent this bit of brain damage, pasting things together |
617 | correctly in make_edges. | |
2c3a56ad | 618 | |
e881bb1b RH |
619 | The correct solution involves emitting the table directly |
620 | on the tablejump instruction as a note, or JUMP_LABEL. */ | |
e658434c | 621 | |
e881bb1b RH |
622 | if (GET_CODE (PATTERN (insn)) == ADDR_VEC |
623 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC) | |
624 | { | |
625 | head = end = NULL; | |
626 | n_basic_blocks--; | |
627 | break; | |
628 | } | |
629 | } | |
630 | end = insn; | |
631 | goto new_bb_inclusive; | |
d7429b6a | 632 | |
e881bb1b RH |
633 | case BARRIER: |
634 | /* A basic block ends at a barrier. It may be that an unconditional | |
635 | jump already closed the basic block -- no need to do it again. */ | |
636 | if (head == NULL_RTX) | |
637 | break; | |
d7429b6a | 638 | |
e881bb1b RH |
639 | /* While we now have edge lists with which other portions of the |
640 | compiler might determine a call ending a basic block does not | |
641 | imply an abnormal edge, it will be a bit before everything can | |
642 | be updated. So continue to emit a noop at the end of such a | |
643 | block. */ | |
0a1c58a2 JL |
644 | if (GET_CODE (end) == CALL_INSN |
645 | && ! SIBLING_CALL_P (end)) | |
e881bb1b RH |
646 | { |
647 | rtx nop = gen_rtx_USE (VOIDmode, const0_rtx); | |
648 | end = emit_insn_after (nop, end); | |
649 | } | |
650 | goto new_bb_exclusive; | |
651 | ||
652 | case CALL_INSN: | |
653 | /* A basic block ends at a call that can either throw or | |
654 | do a non-local goto. */ | |
655 | if (call_has_abnormal_edge) | |
656 | { | |
657 | new_bb_inclusive: | |
658 | if (head == NULL_RTX) | |
659 | head = insn; | |
660 | end = insn; | |
661 | ||
662 | new_bb_exclusive: | |
e881bb1b RH |
663 | create_basic_block (i++, head, end, bb_note); |
664 | head = end = NULL_RTX; | |
665 | bb_note = NULL_RTX; | |
666 | break; | |
667 | } | |
668 | /* FALLTHRU */ | |
d7429b6a | 669 | |
e881bb1b RH |
670 | default: |
671 | if (GET_RTX_CLASS (code) == 'i') | |
672 | { | |
673 | if (head == NULL_RTX) | |
674 | head = insn; | |
675 | end = insn; | |
676 | } | |
677 | break; | |
678 | } | |
d7429b6a | 679 | |
e881bb1b | 680 | if (GET_RTX_CLASS (code) == 'i') |
d7429b6a | 681 | { |
e881bb1b | 682 | rtx note; |
421382ac | 683 | |
e881bb1b RH |
684 | /* Make a list of all labels referred to other than by jumps |
685 | (which just don't have the REG_LABEL notes). | |
2ec1535d | 686 | |
e881bb1b RH |
687 | Make a special exception for labels followed by an ADDR*VEC, |
688 | as this would be a part of the tablejump setup code. | |
421382ac | 689 | |
e881bb1b RH |
690 | Make a special exception for the eh_return_stub_label, which |
691 | we know isn't part of any otherwise visible control flow. */ | |
692 | ||
693 | for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) | |
694 | if (REG_NOTE_KIND (note) == REG_LABEL) | |
695 | { | |
696 | rtx lab = XEXP (note, 0), next; | |
697 | ||
698 | if (lab == eh_return_stub_label) | |
699 | ; | |
700 | else if ((next = next_nonnote_insn (lab)) != NULL | |
701 | && GET_CODE (next) == JUMP_INSN | |
702 | && (GET_CODE (PATTERN (next)) == ADDR_VEC | |
703 | || GET_CODE (PATTERN (next)) == ADDR_DIFF_VEC)) | |
704 | ; | |
705 | else | |
706 | label_value_list | |
d3a923ee | 707 | = alloc_EXPR_LIST (0, XEXP (note, 0), label_value_list); |
d7429b6a RK |
708 | } |
709 | } | |
e881bb1b | 710 | } |
d7429b6a | 711 | |
e881bb1b | 712 | if (head != NULL_RTX) |
336a6399 | 713 | create_basic_block (i++, head, end, bb_note); |
af14ce9c | 714 | |
e881bb1b RH |
715 | if (i != n_basic_blocks) |
716 | abort (); | |
af14ce9c | 717 | |
e881bb1b | 718 | return label_value_list; |
d7429b6a | 719 | } |
5ece9746 | 720 | |
19d3c25c RH |
721 | /* Tidy the CFG by deleting unreachable code and whatnot. */ |
722 | ||
723 | void | |
724 | cleanup_cfg (f) | |
725 | rtx f; | |
726 | { | |
727 | delete_unreachable_blocks (); | |
728 | move_stray_eh_region_notes (); | |
729 | record_active_eh_regions (f); | |
730 | try_merge_blocks (); | |
731 | mark_critical_edges (); | |
2cade2ad CP |
732 | |
733 | /* Kill the data we won't maintain. */ | |
734 | label_value_list = NULL_RTX; | |
19d3c25c RH |
735 | } |
736 | ||
e881bb1b RH |
737 | /* Create a new basic block consisting of the instructions between |
738 | HEAD and END inclusive. Reuses the note and basic block struct | |
739 | in BB_NOTE, if any. */ | |
5ece9746 | 740 | |
295ae817 | 741 | void |
e881bb1b RH |
742 | create_basic_block (index, head, end, bb_note) |
743 | int index; | |
744 | rtx head, end, bb_note; | |
5ece9746 | 745 | { |
e881bb1b RH |
746 | basic_block bb; |
747 | ||
748 | if (bb_note | |
b3bf5bde | 749 | && ! RTX_INTEGRATED_P (bb_note) |
e881bb1b RH |
750 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL |
751 | && bb->aux == NULL) | |
5ece9746 | 752 | { |
e881bb1b RH |
753 | /* If we found an existing note, thread it back onto the chain. */ |
754 | ||
755 | if (GET_CODE (head) == CODE_LABEL) | |
756 | add_insn_after (bb_note, head); | |
757 | else | |
758 | { | |
759 | add_insn_before (bb_note, head); | |
760 | head = bb_note; | |
761 | } | |
5ece9746 | 762 | } |
e881bb1b RH |
763 | else |
764 | { | |
765 | /* Otherwise we must create a note and a basic block structure. | |
766 | Since we allow basic block structs in rtl, give the struct | |
767 | the same lifetime by allocating it off the function obstack | |
768 | rather than using malloc. */ | |
8329b5ec | 769 | |
e881bb1b RH |
770 | bb = (basic_block) obstack_alloc (function_obstack, sizeof (*bb)); |
771 | memset (bb, 0, sizeof (*bb)); | |
421382ac | 772 | |
e881bb1b RH |
773 | if (GET_CODE (head) == CODE_LABEL) |
774 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
775 | else | |
776 | { | |
777 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
778 | head = bb_note; | |
779 | } | |
780 | NOTE_BASIC_BLOCK (bb_note) = bb; | |
781 | } | |
782 | ||
eeea333e RH |
783 | /* Always include the bb note in the block. */ |
784 | if (NEXT_INSN (end) == bb_note) | |
785 | end = bb_note; | |
786 | ||
e881bb1b RH |
787 | bb->head = head; |
788 | bb->end = end; | |
789 | bb->index = index; | |
790 | BASIC_BLOCK (index) = bb; | |
791 | ||
792 | /* Tag the block so that we know it has been used when considering | |
793 | other basic block notes. */ | |
794 | bb->aux = bb; | |
421382ac | 795 | } |
e881bb1b RH |
796 | \f |
797 | /* Records the basic block struct in BB_FOR_INSN, for every instruction | |
798 | indexed by INSN_UID. MAX is the size of the array. */ | |
421382ac | 799 | |
2307e372 RH |
800 | void |
801 | compute_bb_for_insn (max) | |
e881bb1b | 802 | int max; |
421382ac | 803 | { |
e881bb1b | 804 | int i; |
421382ac | 805 | |
49c3bb12 RH |
806 | if (basic_block_for_insn) |
807 | VARRAY_FREE (basic_block_for_insn); | |
2307e372 RH |
808 | VARRAY_BB_INIT (basic_block_for_insn, max, "basic_block_for_insn"); |
809 | ||
e881bb1b RH |
810 | for (i = 0; i < n_basic_blocks; ++i) |
811 | { | |
812 | basic_block bb = BASIC_BLOCK (i); | |
813 | rtx insn, end; | |
814 | ||
815 | end = bb->end; | |
816 | insn = bb->head; | |
817 | while (1) | |
818 | { | |
819 | int uid = INSN_UID (insn); | |
820 | if (uid < max) | |
2307e372 | 821 | VARRAY_BB (basic_block_for_insn, uid) = bb; |
e881bb1b RH |
822 | if (insn == end) |
823 | break; | |
824 | insn = NEXT_INSN (insn); | |
825 | } | |
826 | } | |
421382ac BS |
827 | } |
828 | ||
e881bb1b | 829 | /* Free the memory associated with the edge structures. */ |
421382ac BS |
830 | |
831 | static void | |
e881bb1b | 832 | clear_edges () |
421382ac | 833 | { |
e881bb1b RH |
834 | int i; |
835 | edge n, e; | |
421382ac | 836 | |
e881bb1b | 837 | for (i = 0; i < n_basic_blocks; ++i) |
421382ac | 838 | { |
e881bb1b | 839 | basic_block bb = BASIC_BLOCK (i); |
421382ac | 840 | |
e881bb1b | 841 | for (e = bb->succ; e ; e = n) |
421382ac | 842 | { |
e881bb1b RH |
843 | n = e->succ_next; |
844 | free (e); | |
421382ac | 845 | } |
e881bb1b RH |
846 | |
847 | bb->succ = 0; | |
848 | bb->pred = 0; | |
849 | } | |
850 | ||
851 | for (e = ENTRY_BLOCK_PTR->succ; e ; e = n) | |
852 | { | |
853 | n = e->succ_next; | |
854 | free (e); | |
421382ac | 855 | } |
e881bb1b RH |
856 | |
857 | ENTRY_BLOCK_PTR->succ = 0; | |
858 | EXIT_BLOCK_PTR->pred = 0; | |
d3a923ee RH |
859 | |
860 | n_edges = 0; | |
421382ac BS |
861 | } |
862 | ||
e881bb1b RH |
863 | /* Identify the edges between basic blocks. |
864 | ||
865 | NONLOCAL_LABEL_LIST is a list of non-local labels in the function. Blocks | |
866 | that are otherwise unreachable may be reachable with a non-local goto. | |
867 | ||
868 | BB_EH_END is an array indexed by basic block number in which we record | |
869 | the list of exception regions active at the end of the basic block. */ | |
870 | ||
dc2ede84 | 871 | static void |
336a6399 | 872 | make_edges (label_value_list) |
e881bb1b | 873 | rtx label_value_list; |
dc2ede84 | 874 | { |
e881bb1b | 875 | int i; |
1ef1bf06 | 876 | eh_nesting_info *eh_nest_info = init_eh_nesting_info (); |
dbf08f94 | 877 | sbitmap *edge_cache = NULL; |
e881bb1b RH |
878 | |
879 | /* Assume no computed jump; revise as we create edges. */ | |
880 | current_function_has_computed_jump = 0; | |
881 | ||
dbf08f94 RH |
882 | /* Heavy use of computed goto in machine-generated code can lead to |
883 | nearly fully-connected CFGs. In that case we spend a significant | |
884 | amount of time searching the edge lists for duplicates. */ | |
885 | if (forced_labels || label_value_list) | |
886 | { | |
887 | edge_cache = sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks); | |
888 | sbitmap_vector_zero (edge_cache, n_basic_blocks); | |
889 | } | |
890 | ||
e881bb1b | 891 | /* By nature of the way these get numbered, block 0 is always the entry. */ |
dbf08f94 | 892 | make_edge (edge_cache, ENTRY_BLOCK_PTR, BASIC_BLOCK (0), EDGE_FALLTHRU); |
dc2ede84 | 893 | |
e881bb1b | 894 | for (i = 0; i < n_basic_blocks; ++i) |
421382ac | 895 | { |
e881bb1b | 896 | basic_block bb = BASIC_BLOCK (i); |
336a6399 | 897 | rtx insn, x; |
e881bb1b | 898 | enum rtx_code code; |
4b523fc4 | 899 | int force_fallthru = 0; |
421382ac | 900 | |
336a6399 | 901 | /* Examine the last instruction of the block, and discover the |
e881bb1b RH |
902 | ways we can leave the block. */ |
903 | ||
904 | insn = bb->end; | |
905 | code = GET_CODE (insn); | |
906 | ||
907 | /* A branch. */ | |
908 | if (code == JUMP_INSN) | |
909 | { | |
910 | rtx tmp; | |
911 | ||
912 | /* ??? Recognize a tablejump and do the right thing. */ | |
913 | if ((tmp = JUMP_LABEL (insn)) != NULL_RTX | |
914 | && (tmp = NEXT_INSN (tmp)) != NULL_RTX | |
915 | && GET_CODE (tmp) == JUMP_INSN | |
916 | && (GET_CODE (PATTERN (tmp)) == ADDR_VEC | |
917 | || GET_CODE (PATTERN (tmp)) == ADDR_DIFF_VEC)) | |
918 | { | |
919 | rtvec vec; | |
920 | int j; | |
921 | ||
922 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) | |
923 | vec = XVEC (PATTERN (tmp), 0); | |
924 | else | |
925 | vec = XVEC (PATTERN (tmp), 1); | |
926 | ||
927 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
dbf08f94 RH |
928 | make_label_edge (edge_cache, bb, |
929 | XEXP (RTVEC_ELT (vec, j), 0), 0); | |
4b523fc4 RE |
930 | |
931 | /* Some targets (eg, ARM) emit a conditional jump that also | |
932 | contains the out-of-range target. Scan for these and | |
933 | add an edge if necessary. */ | |
934 | if ((tmp = single_set (insn)) != NULL | |
935 | && SET_DEST (tmp) == pc_rtx | |
936 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
937 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF) | |
dbf08f94 RH |
938 | make_label_edge (edge_cache, bb, |
939 | XEXP (XEXP (SET_SRC (tmp), 2), 0), 0); | |
4b523fc4 RE |
940 | |
941 | #ifdef CASE_DROPS_THROUGH | |
942 | /* Silly VAXen. The ADDR_VEC is going to be in the way of | |
943 | us naturally detecting fallthru into the next block. */ | |
944 | force_fallthru = 1; | |
945 | #endif | |
e881bb1b RH |
946 | } |
947 | ||
948 | /* If this is a computed jump, then mark it as reaching | |
949 | everything on the label_value_list and forced_labels list. */ | |
950 | else if (computed_jump_p (insn)) | |
951 | { | |
dc2ede84 | 952 | current_function_has_computed_jump = 1; |
dc2ede84 | 953 | |
e881bb1b | 954 | for (x = label_value_list; x; x = XEXP (x, 1)) |
dbf08f94 | 955 | make_label_edge (edge_cache, bb, XEXP (x, 0), EDGE_ABNORMAL); |
e881bb1b | 956 | |
dc2ede84 | 957 | for (x = forced_labels; x; x = XEXP (x, 1)) |
dbf08f94 | 958 | make_label_edge (edge_cache, bb, XEXP (x, 0), EDGE_ABNORMAL); |
dc2ede84 BS |
959 | } |
960 | ||
e881bb1b RH |
961 | /* Returns create an exit out. */ |
962 | else if (returnjump_p (insn)) | |
dbf08f94 | 963 | make_edge (edge_cache, bb, EXIT_BLOCK_PTR, 0); |
e881bb1b RH |
964 | |
965 | /* Otherwise, we have a plain conditional or unconditional jump. */ | |
966 | else | |
dc2ede84 | 967 | { |
e881bb1b RH |
968 | if (! JUMP_LABEL (insn)) |
969 | abort (); | |
dbf08f94 | 970 | make_label_edge (edge_cache, bb, JUMP_LABEL (insn), 0); |
e881bb1b RH |
971 | } |
972 | } | |
973 | ||
0a1c58a2 JL |
974 | /* If this is a sibling call insn, then this is in effect a |
975 | combined call and return, and so we need an edge to the | |
976 | exit block. No need to worry about EH edges, since we | |
977 | wouldn't have created the sibling call in the first place. */ | |
978 | ||
979 | if (code == CALL_INSN && SIBLING_CALL_P (insn)) | |
980 | make_edge (edge_cache, bb, EXIT_BLOCK_PTR, 0); | |
981 | else | |
982 | ||
e881bb1b RH |
983 | /* If this is a CALL_INSN, then mark it as reaching the active EH |
984 | handler for this CALL_INSN. If we're handling asynchronous | |
985 | exceptions then any insn can reach any of the active handlers. | |
b472794d | 986 | |
e881bb1b | 987 | Also mark the CALL_INSN as reaching any nonlocal goto handler. */ |
b472794d | 988 | |
a3e924fc | 989 | if (code == CALL_INSN || asynchronous_exceptions) |
e881bb1b | 990 | { |
6814a8a0 JM |
991 | /* Add any appropriate EH edges. We do this unconditionally |
992 | since there may be a REG_EH_REGION or REG_EH_RETHROW note | |
993 | on the call, and this needn't be within an EH region. */ | |
994 | make_eh_edge (edge_cache, eh_nest_info, bb, insn, bb->eh_end); | |
336a6399 RH |
995 | |
996 | /* If we have asynchronous exceptions, do the same for *all* | |
997 | exception regions active in the block. */ | |
998 | if (asynchronous_exceptions | |
999 | && bb->eh_beg != bb->eh_end) | |
e881bb1b | 1000 | { |
336a6399 | 1001 | if (bb->eh_beg >= 0) |
dbf08f94 RH |
1002 | make_eh_edge (edge_cache, eh_nest_info, bb, |
1003 | NULL_RTX, bb->eh_beg); | |
336a6399 | 1004 | |
7a3b7acb | 1005 | for (x = bb->head; x != bb->end; x = NEXT_INSN (x)) |
336a6399 RH |
1006 | if (GET_CODE (x) == NOTE |
1007 | && (NOTE_LINE_NUMBER (x) == NOTE_INSN_EH_REGION_BEG | |
1008 | || NOTE_LINE_NUMBER (x) == NOTE_INSN_EH_REGION_END)) | |
1009 | { | |
1010 | int region = NOTE_EH_HANDLER (x); | |
dbf08f94 RH |
1011 | make_eh_edge (edge_cache, eh_nest_info, bb, |
1012 | NULL_RTX, region); | |
336a6399 | 1013 | } |
e881bb1b RH |
1014 | } |
1015 | ||
1016 | if (code == CALL_INSN && nonlocal_goto_handler_labels) | |
1017 | { | |
dc2ede84 BS |
1018 | /* ??? This could be made smarter: in some cases it's possible |
1019 | to tell that certain calls will not do a nonlocal goto. | |
1020 | ||
1021 | For example, if the nested functions that do the nonlocal | |
1022 | gotos do not have their addresses taken, then only calls to | |
1023 | those functions or to other nested functions that use them | |
1024 | could possibly do nonlocal gotos. */ | |
1ef1bf06 AM |
1025 | /* We do know that a REG_EH_REGION note with a value less |
1026 | than 0 is guaranteed not to perform a non-local goto. */ | |
1027 | rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); | |
12a41c48 | 1028 | if (!note || INTVAL (XEXP (note, 0)) >= 0) |
1ef1bf06 | 1029 | for (x = nonlocal_goto_handler_labels; x ; x = XEXP (x, 1)) |
dbf08f94 | 1030 | make_label_edge (edge_cache, bb, XEXP (x, 0), |
1ef1bf06 | 1031 | EDGE_ABNORMAL | EDGE_ABNORMAL_CALL); |
dc2ede84 BS |
1032 | } |
1033 | } | |
e881bb1b RH |
1034 | |
1035 | /* We know something about the structure of the function __throw in | |
1036 | libgcc2.c. It is the only function that ever contains eh_stub | |
1037 | labels. It modifies its return address so that the last block | |
1038 | returns to one of the eh_stub labels within it. So we have to | |
1039 | make additional edges in the flow graph. */ | |
1040 | if (i + 1 == n_basic_blocks && eh_return_stub_label != 0) | |
dbf08f94 | 1041 | make_label_edge (edge_cache, bb, eh_return_stub_label, EDGE_EH); |
e881bb1b RH |
1042 | |
1043 | /* Find out if we can drop through to the next block. */ | |
1044 | insn = next_nonnote_insn (insn); | |
4b523fc4 | 1045 | if (!insn || (i + 1 == n_basic_blocks && force_fallthru)) |
dbf08f94 | 1046 | make_edge (edge_cache, bb, EXIT_BLOCK_PTR, EDGE_FALLTHRU); |
e881bb1b RH |
1047 | else if (i + 1 < n_basic_blocks) |
1048 | { | |
1049 | rtx tmp = BLOCK_HEAD (i + 1); | |
1050 | if (GET_CODE (tmp) == NOTE) | |
1051 | tmp = next_nonnote_insn (tmp); | |
4b523fc4 | 1052 | if (force_fallthru || insn == tmp) |
dbf08f94 | 1053 | make_edge (edge_cache, bb, BASIC_BLOCK (i + 1), EDGE_FALLTHRU); |
e881bb1b | 1054 | } |
dc2ede84 | 1055 | } |
dbf08f94 | 1056 | |
1ef1bf06 | 1057 | free_eh_nesting_info (eh_nest_info); |
dbf08f94 RH |
1058 | if (edge_cache) |
1059 | sbitmap_vector_free (edge_cache); | |
e881bb1b RH |
1060 | } |
1061 | ||
1062 | /* Create an edge between two basic blocks. FLAGS are auxiliary information | |
1063 | about the edge that is accumulated between calls. */ | |
1064 | ||
69732dcb | 1065 | void |
dbf08f94 RH |
1066 | make_edge (edge_cache, src, dst, flags) |
1067 | sbitmap *edge_cache; | |
e881bb1b RH |
1068 | basic_block src, dst; |
1069 | int flags; | |
1070 | { | |
dbf08f94 | 1071 | int use_edge_cache; |
e881bb1b RH |
1072 | edge e; |
1073 | ||
dbf08f94 RH |
1074 | /* Don't bother with edge cache for ENTRY or EXIT; there aren't that |
1075 | many edges to them, and we didn't allocate memory for it. */ | |
1076 | use_edge_cache = (edge_cache | |
1077 | && src != ENTRY_BLOCK_PTR | |
1078 | && dst != EXIT_BLOCK_PTR); | |
e881bb1b | 1079 | |
dbf08f94 RH |
1080 | /* Make sure we don't add duplicate edges. */ |
1081 | if (! use_edge_cache || TEST_BIT (edge_cache[src->index], dst->index)) | |
1082 | for (e = src->succ; e ; e = e->succ_next) | |
1083 | if (e->dest == dst) | |
1084 | { | |
1085 | e->flags |= flags; | |
1086 | return; | |
1087 | } | |
e881bb1b RH |
1088 | |
1089 | e = (edge) xcalloc (1, sizeof (*e)); | |
d3a923ee | 1090 | n_edges++; |
e881bb1b RH |
1091 | |
1092 | e->succ_next = src->succ; | |
1093 | e->pred_next = dst->pred; | |
1094 | e->src = src; | |
1095 | e->dest = dst; | |
1096 | e->flags = flags; | |
1097 | ||
1098 | src->succ = e; | |
1099 | dst->pred = e; | |
dbf08f94 RH |
1100 | |
1101 | if (use_edge_cache) | |
1102 | SET_BIT (edge_cache[src->index], dst->index); | |
e881bb1b RH |
1103 | } |
1104 | ||
1105 | /* Create an edge from a basic block to a label. */ | |
1106 | ||
1107 | static void | |
dbf08f94 RH |
1108 | make_label_edge (edge_cache, src, label, flags) |
1109 | sbitmap *edge_cache; | |
e881bb1b RH |
1110 | basic_block src; |
1111 | rtx label; | |
1112 | int flags; | |
1113 | { | |
1114 | if (GET_CODE (label) != CODE_LABEL) | |
1115 | abort (); | |
1116 | ||
1117 | /* If the label was never emitted, this insn is junk, but avoid a | |
1118 | crash trying to refer to BLOCK_FOR_INSN (label). This can happen | |
1119 | as a result of a syntax error and a diagnostic has already been | |
1120 | printed. */ | |
1121 | ||
1122 | if (INSN_UID (label) == 0) | |
1123 | return; | |
1124 | ||
dbf08f94 | 1125 | make_edge (edge_cache, src, BLOCK_FOR_INSN (label), flags); |
e881bb1b | 1126 | } |
e6cfb550 | 1127 | |
336a6399 RH |
1128 | /* Create the edges generated by INSN in REGION. */ |
1129 | ||
1130 | static void | |
dbf08f94 RH |
1131 | make_eh_edge (edge_cache, eh_nest_info, src, insn, region) |
1132 | sbitmap *edge_cache; | |
336a6399 RH |
1133 | eh_nesting_info *eh_nest_info; |
1134 | basic_block src; | |
1135 | rtx insn; | |
1136 | int region; | |
1137 | { | |
1138 | handler_info **handler_list; | |
1139 | int num, is_call; | |
1140 | ||
1141 | is_call = (insn && GET_CODE (insn) == CALL_INSN ? EDGE_ABNORMAL_CALL : 0); | |
1142 | num = reachable_handlers (region, eh_nest_info, insn, &handler_list); | |
1143 | while (--num >= 0) | |
1144 | { | |
dbf08f94 | 1145 | make_label_edge (edge_cache, src, handler_list[num]->handler_label, |
336a6399 RH |
1146 | EDGE_ABNORMAL | EDGE_EH | is_call); |
1147 | } | |
1148 | } | |
1149 | ||
1150 | /* EH_REGION notes appearing between basic blocks is ambiguous, and even | |
1151 | dangerous if we intend to move basic blocks around. Move such notes | |
1152 | into the following block. */ | |
1153 | ||
1154 | static void | |
1155 | move_stray_eh_region_notes () | |
1156 | { | |
1157 | int i; | |
1158 | basic_block b1, b2; | |
1159 | ||
1160 | if (n_basic_blocks < 2) | |
1161 | return; | |
1162 | ||
1163 | b2 = BASIC_BLOCK (n_basic_blocks - 1); | |
1164 | for (i = n_basic_blocks - 2; i >= 0; --i, b2 = b1) | |
1165 | { | |
1166 | rtx insn, next, list = NULL_RTX; | |
1167 | ||
1168 | b1 = BASIC_BLOCK (i); | |
1169 | for (insn = NEXT_INSN (b1->end); insn != b2->head; insn = next) | |
1170 | { | |
1171 | next = NEXT_INSN (insn); | |
1172 | if (GET_CODE (insn) == NOTE | |
1173 | && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG | |
1174 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)) | |
1175 | { | |
1176 | /* Unlink from the insn chain. */ | |
1177 | NEXT_INSN (PREV_INSN (insn)) = next; | |
1178 | PREV_INSN (next) = PREV_INSN (insn); | |
1179 | ||
1180 | /* Queue it. */ | |
1181 | NEXT_INSN (insn) = list; | |
1182 | list = insn; | |
1183 | } | |
1184 | } | |
1185 | ||
1186 | if (list == NULL_RTX) | |
1187 | continue; | |
1188 | ||
1189 | /* Find where to insert these things. */ | |
1190 | insn = b2->head; | |
1191 | if (GET_CODE (insn) == CODE_LABEL) | |
1192 | insn = NEXT_INSN (insn); | |
1193 | ||
1194 | while (list) | |
1195 | { | |
1196 | next = NEXT_INSN (list); | |
1197 | add_insn_after (list, insn); | |
1198 | list = next; | |
1199 | } | |
1200 | } | |
1201 | } | |
1202 | ||
1203 | /* Recompute eh_beg/eh_end for each basic block. */ | |
1204 | ||
1205 | static void | |
1206 | record_active_eh_regions (f) | |
1207 | rtx f; | |
1208 | { | |
1209 | rtx insn, eh_list = NULL_RTX; | |
1210 | int i = 0; | |
1211 | basic_block bb = BASIC_BLOCK (0); | |
1212 | ||
1213 | for (insn = f; insn ; insn = NEXT_INSN (insn)) | |
1214 | { | |
1215 | if (bb->head == insn) | |
1216 | bb->eh_beg = (eh_list ? NOTE_EH_HANDLER (XEXP (eh_list, 0)) : -1); | |
1217 | ||
1218 | if (GET_CODE (insn) == NOTE) | |
1219 | { | |
1220 | int kind = NOTE_LINE_NUMBER (insn); | |
1221 | if (kind == NOTE_INSN_EH_REGION_BEG) | |
1222 | eh_list = alloc_INSN_LIST (insn, eh_list); | |
1223 | else if (kind == NOTE_INSN_EH_REGION_END) | |
1224 | { | |
1225 | rtx t = XEXP (eh_list, 1); | |
1226 | free_INSN_LIST_node (eh_list); | |
1227 | eh_list = t; | |
1228 | } | |
1229 | } | |
1230 | ||
1231 | if (bb->end == insn) | |
1232 | { | |
1233 | bb->eh_end = (eh_list ? NOTE_EH_HANDLER (XEXP (eh_list, 0)) : -1); | |
1234 | i += 1; | |
30439f29 JL |
1235 | if (i == n_basic_blocks) |
1236 | break; | |
336a6399 RH |
1237 | bb = BASIC_BLOCK (i); |
1238 | } | |
1239 | } | |
1240 | } | |
1241 | ||
e881bb1b | 1242 | /* Identify critical edges and set the bits appropriately. */ |
336a6399 | 1243 | |
e881bb1b RH |
1244 | static void |
1245 | mark_critical_edges () | |
1246 | { | |
1247 | int i, n = n_basic_blocks; | |
1248 | basic_block bb; | |
1249 | ||
1250 | /* We begin with the entry block. This is not terribly important now, | |
1251 | but could be if a front end (Fortran) implemented alternate entry | |
1252 | points. */ | |
1253 | bb = ENTRY_BLOCK_PTR; | |
1254 | i = -1; | |
1255 | ||
1256 | while (1) | |
e6cfb550 | 1257 | { |
e881bb1b RH |
1258 | edge e; |
1259 | ||
1260 | /* (1) Critical edges must have a source with multiple successors. */ | |
1261 | if (bb->succ && bb->succ->succ_next) | |
1262 | { | |
1263 | for (e = bb->succ; e ; e = e->succ_next) | |
1264 | { | |
1265 | /* (2) Critical edges must have a destination with multiple | |
1266 | predecessors. Note that we know there is at least one | |
1267 | predecessor -- the edge we followed to get here. */ | |
1268 | if (e->dest->pred->pred_next) | |
1269 | e->flags |= EDGE_CRITICAL; | |
1270 | else | |
1271 | e->flags &= ~EDGE_CRITICAL; | |
1272 | } | |
1273 | } | |
1274 | else | |
1275 | { | |
1276 | for (e = bb->succ; e ; e = e->succ_next) | |
1277 | e->flags &= ~EDGE_CRITICAL; | |
1278 | } | |
1279 | ||
1280 | if (++i >= n) | |
1281 | break; | |
1282 | bb = BASIC_BLOCK (i); | |
e6cfb550 | 1283 | } |
e881bb1b RH |
1284 | } |
1285 | \f | |
1286 | /* Split a (typically critical) edge. Return the new block. | |
1287 | Abort on abnormal edges. | |
1288 | ||
1289 | ??? The code generally expects to be called on critical edges. | |
1290 | The case of a block ending in an unconditional jump to a | |
1291 | block with multiple predecessors is not handled optimally. */ | |
1292 | ||
1293 | basic_block | |
1294 | split_edge (edge_in) | |
1295 | edge edge_in; | |
1296 | { | |
1297 | basic_block old_pred, bb, old_succ; | |
1298 | edge edge_out; | |
1299 | rtx bb_note; | |
abb14ef5 | 1300 | int i, j; |
e881bb1b RH |
1301 | |
1302 | /* Abnormal edges cannot be split. */ | |
1303 | if ((edge_in->flags & EDGE_ABNORMAL) != 0) | |
1304 | abort (); | |
1305 | ||
1306 | old_pred = edge_in->src; | |
1307 | old_succ = edge_in->dest; | |
1308 | ||
1309 | /* Remove the existing edge from the destination's pred list. */ | |
1310 | { | |
1311 | edge *pp; | |
1312 | for (pp = &old_succ->pred; *pp != edge_in; pp = &(*pp)->pred_next) | |
1313 | continue; | |
1314 | *pp = edge_in->pred_next; | |
1e7d57a3 | 1315 | edge_in->pred_next = NULL; |
e881bb1b RH |
1316 | } |
1317 | ||
1318 | /* Create the new structures. */ | |
1319 | bb = (basic_block) obstack_alloc (function_obstack, sizeof (*bb)); | |
1320 | edge_out = (edge) xcalloc (1, sizeof (*edge_out)); | |
d3a923ee | 1321 | n_edges++; |
e881bb1b RH |
1322 | |
1323 | memset (bb, 0, sizeof (*bb)); | |
e881bb1b RH |
1324 | bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (function_obstack); |
1325 | bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (function_obstack); | |
1326 | ||
1327 | /* ??? This info is likely going to be out of date very soon. */ | |
e881bb1b RH |
1328 | if (old_succ->global_live_at_start) |
1329 | { | |
1330 | COPY_REG_SET (bb->global_live_at_start, old_succ->global_live_at_start); | |
1331 | COPY_REG_SET (bb->global_live_at_end, old_succ->global_live_at_start); | |
1332 | } | |
1333 | else | |
1334 | { | |
1335 | CLEAR_REG_SET (bb->global_live_at_start); | |
1336 | CLEAR_REG_SET (bb->global_live_at_end); | |
1337 | } | |
1338 | ||
1339 | /* Wire them up. */ | |
1340 | bb->pred = edge_in; | |
1341 | bb->succ = edge_out; | |
1e7d57a3 | 1342 | |
e881bb1b | 1343 | edge_in->dest = bb; |
1e7d57a3 JH |
1344 | edge_in->flags &= ~EDGE_CRITICAL; |
1345 | ||
1346 | edge_out->pred_next = old_succ->pred; | |
1347 | edge_out->succ_next = NULL; | |
e881bb1b RH |
1348 | edge_out->src = bb; |
1349 | edge_out->dest = old_succ; | |
1e7d57a3 JH |
1350 | edge_out->flags = EDGE_FALLTHRU; |
1351 | edge_out->probability = REG_BR_PROB_BASE; | |
1352 | ||
1353 | old_succ->pred = edge_out; | |
e881bb1b RH |
1354 | |
1355 | /* Tricky case -- if there existed a fallthru into the successor | |
1356 | (and we're not it) we must add a new unconditional jump around | |
1357 | the new block we're actually interested in. | |
1358 | ||
1359 | Further, if that edge is critical, this means a second new basic | |
1360 | block must be created to hold it. In order to simplify correct | |
1361 | insn placement, do this before we touch the existing basic block | |
1362 | ordering for the block we were really wanting. */ | |
1363 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1364 | { | |
1365 | edge e; | |
1e7d57a3 | 1366 | for (e = edge_out->pred_next; e ; e = e->pred_next) |
e881bb1b RH |
1367 | if (e->flags & EDGE_FALLTHRU) |
1368 | break; | |
1369 | ||
1370 | if (e) | |
1371 | { | |
1372 | basic_block jump_block; | |
1373 | rtx pos; | |
1374 | ||
d9d4fb43 AS |
1375 | if ((e->flags & EDGE_CRITICAL) == 0 |
1376 | && e->src != ENTRY_BLOCK_PTR) | |
e881bb1b RH |
1377 | { |
1378 | /* Non critical -- we can simply add a jump to the end | |
1379 | of the existing predecessor. */ | |
1380 | jump_block = e->src; | |
e881bb1b RH |
1381 | } |
1382 | else | |
1383 | { | |
1384 | /* We need a new block to hold the jump. The simplest | |
1385 | way to do the bulk of the work here is to recursively | |
1386 | call ourselves. */ | |
1387 | jump_block = split_edge (e); | |
1388 | e = jump_block->succ; | |
e881bb1b RH |
1389 | } |
1390 | ||
1e7d57a3 JH |
1391 | /* Now add the jump insn ... */ |
1392 | pos = emit_jump_insn_after (gen_jump (old_succ->head), | |
1393 | jump_block->end); | |
e881bb1b | 1394 | jump_block->end = pos; |
414094de JL |
1395 | if (basic_block_for_insn) |
1396 | set_block_for_insn (pos, jump_block); | |
e881bb1b | 1397 | emit_barrier_after (pos); |
1e7d57a3 JH |
1398 | |
1399 | /* ... let jump know that label is in use, ... */ | |
a8688bd6 | 1400 | JUMP_LABEL (pos) = old_succ->head; |
1e7d57a3 | 1401 | ++LABEL_NUSES (old_succ->head); |
088e7160 | 1402 | |
e881bb1b RH |
1403 | /* ... and clear fallthru on the outgoing edge. */ |
1404 | e->flags &= ~EDGE_FALLTHRU; | |
1405 | ||
1406 | /* Continue splitting the interesting edge. */ | |
1407 | } | |
1408 | } | |
1409 | ||
1410 | /* Place the new block just in front of the successor. */ | |
1411 | VARRAY_GROW (basic_block_info, ++n_basic_blocks); | |
abb14ef5 AM |
1412 | if (old_succ == EXIT_BLOCK_PTR) |
1413 | j = n_basic_blocks - 1; | |
1414 | else | |
1415 | j = old_succ->index; | |
1416 | for (i = n_basic_blocks - 1; i > j; --i) | |
e881bb1b RH |
1417 | { |
1418 | basic_block tmp = BASIC_BLOCK (i - 1); | |
1419 | BASIC_BLOCK (i) = tmp; | |
1420 | tmp->index = i; | |
1421 | } | |
1422 | BASIC_BLOCK (i) = bb; | |
1423 | bb->index = i; | |
1424 | ||
9aa137f3 JL |
1425 | /* Create the basic block note. |
1426 | ||
1427 | Where we place the note can have a noticable impact on the generated | |
1428 | code. Consider this cfg: | |
1429 | ||
1430 | ||
1431 | E | |
1432 | | | |
1433 | 0 | |
1434 | / \ | |
1435 | +->1-->2--->E | |
1436 | | | | |
1437 | +--+ | |
1438 | ||
1439 | If we need to insert an insn on the edge from block 0 to block 1, | |
1440 | we want to ensure the instructions we insert are outside of any | |
1441 | loop notes that physically sit between block 0 and block 1. Otherwise | |
1442 | we confuse the loop optimizer into thinking the loop is a phony. */ | |
1443 | if (old_succ != EXIT_BLOCK_PTR | |
1444 | && PREV_INSN (old_succ->head) | |
1445 | && GET_CODE (PREV_INSN (old_succ->head)) == NOTE | |
1446 | && NOTE_LINE_NUMBER (PREV_INSN (old_succ->head)) == NOTE_INSN_LOOP_BEG) | |
1447 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, | |
1448 | PREV_INSN (old_succ->head)); | |
1449 | else if (old_succ != EXIT_BLOCK_PTR) | |
abb14ef5 AM |
1450 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, old_succ->head); |
1451 | else | |
1452 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
e881bb1b RH |
1453 | NOTE_BASIC_BLOCK (bb_note) = bb; |
1454 | bb->head = bb->end = bb_note; | |
1455 | ||
1456 | /* Not quite simple -- for non-fallthru edges, we must adjust the | |
1457 | predecessor's jump instruction to target our new block. */ | |
1458 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1459 | { | |
1460 | rtx tmp, insn = old_pred->end; | |
1461 | rtx old_label = old_succ->head; | |
1462 | rtx new_label = gen_label_rtx (); | |
1463 | ||
1464 | if (GET_CODE (insn) != JUMP_INSN) | |
1465 | abort (); | |
1466 | ||
1467 | /* ??? Recognize a tablejump and adjust all matching cases. */ | |
1468 | if ((tmp = JUMP_LABEL (insn)) != NULL_RTX | |
1469 | && (tmp = NEXT_INSN (tmp)) != NULL_RTX | |
1470 | && GET_CODE (tmp) == JUMP_INSN | |
1471 | && (GET_CODE (PATTERN (tmp)) == ADDR_VEC | |
1472 | || GET_CODE (PATTERN (tmp)) == ADDR_DIFF_VEC)) | |
1473 | { | |
1474 | rtvec vec; | |
1475 | int j; | |
1476 | ||
1477 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) | |
1478 | vec = XVEC (PATTERN (tmp), 0); | |
1479 | else | |
1480 | vec = XVEC (PATTERN (tmp), 1); | |
1481 | ||
1482 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
1483 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
1484 | { | |
1485 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (VOIDmode, new_label); | |
1486 | --LABEL_NUSES (old_label); | |
1487 | ++LABEL_NUSES (new_label); | |
1488 | } | |
506f9fbf RE |
1489 | |
1490 | /* Handle casesi dispatch insns */ | |
1491 | if ((tmp = single_set (insn)) != NULL | |
1492 | && SET_DEST (tmp) == pc_rtx | |
1493 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
1494 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF | |
1495 | && XEXP (XEXP (SET_SRC (tmp), 2), 0) == old_label) | |
1496 | { | |
1497 | XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (VOIDmode, | |
1498 | new_label); | |
1499 | --LABEL_NUSES (old_label); | |
1500 | ++LABEL_NUSES (new_label); | |
1501 | } | |
e881bb1b RH |
1502 | } |
1503 | else | |
1504 | { | |
1505 | /* This would have indicated an abnormal edge. */ | |
1506 | if (computed_jump_p (insn)) | |
1507 | abort (); | |
1508 | ||
1509 | /* A return instruction can't be redirected. */ | |
1510 | if (returnjump_p (insn)) | |
1511 | abort (); | |
1512 | ||
1513 | /* If the insn doesn't go where we think, we're confused. */ | |
1514 | if (JUMP_LABEL (insn) != old_label) | |
1515 | abort (); | |
1516 | ||
1517 | redirect_jump (insn, new_label); | |
1518 | } | |
1519 | ||
1520 | emit_label_before (new_label, bb_note); | |
1521 | bb->head = new_label; | |
1522 | } | |
1523 | ||
e881bb1b RH |
1524 | return bb; |
1525 | } | |
1526 | ||
1527 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1528 | The new instructions and basic blocks (if any) will not appear in the | |
1529 | CFG until commit_edge_insertions is called. */ | |
1530 | ||
1531 | void | |
1532 | insert_insn_on_edge (pattern, e) | |
1533 | rtx pattern; | |
1534 | edge e; | |
1535 | { | |
1536 | /* We cannot insert instructions on an abnormal critical edge. | |
1537 | It will be easier to find the culprit if we die now. */ | |
1538 | if ((e->flags & (EDGE_ABNORMAL|EDGE_CRITICAL)) | |
1539 | == (EDGE_ABNORMAL|EDGE_CRITICAL)) | |
1540 | abort (); | |
1541 | ||
1542 | if (e->insns == NULL_RTX) | |
1543 | start_sequence (); | |
1544 | else | |
1545 | push_to_sequence (e->insns); | |
1546 | ||
1547 | emit_insn (pattern); | |
1548 | ||
1549 | e->insns = get_insns (); | |
1550 | end_sequence(); | |
1551 | } | |
1552 | ||
1553 | /* Update the CFG for the instructions queued on edge E. */ | |
1554 | ||
1555 | static void | |
1556 | commit_one_edge_insertion (e) | |
1557 | edge e; | |
1558 | { | |
19d3c25c | 1559 | rtx before = NULL_RTX, after = NULL_RTX, insns, tmp; |
e881bb1b RH |
1560 | basic_block bb; |
1561 | ||
19d3c25c RH |
1562 | /* Pull the insns off the edge now since the edge might go away. */ |
1563 | insns = e->insns; | |
1564 | e->insns = NULL_RTX; | |
1565 | ||
e881bb1b RH |
1566 | /* Figure out where to put these things. If the destination has |
1567 | one predecessor, insert there. Except for the exit block. */ | |
1568 | if (e->dest->pred->pred_next == NULL | |
1569 | && e->dest != EXIT_BLOCK_PTR) | |
1570 | { | |
1571 | bb = e->dest; | |
1572 | ||
1573 | /* Get the location correct wrt a code label, and "nice" wrt | |
1574 | a basic block note, and before everything else. */ | |
1575 | tmp = bb->head; | |
1576 | if (GET_CODE (tmp) == CODE_LABEL) | |
1577 | tmp = NEXT_INSN (tmp); | |
1578 | if (GET_CODE (tmp) == NOTE | |
1579 | && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_BASIC_BLOCK) | |
1580 | tmp = NEXT_INSN (tmp); | |
1581 | if (tmp == bb->head) | |
1582 | before = tmp; | |
1583 | else | |
1584 | after = PREV_INSN (tmp); | |
1585 | } | |
1586 | ||
1587 | /* If the source has one successor and the edge is not abnormal, | |
1588 | insert there. Except for the entry block. */ | |
1589 | else if ((e->flags & EDGE_ABNORMAL) == 0 | |
1590 | && e->src->succ->succ_next == NULL | |
1591 | && e->src != ENTRY_BLOCK_PTR) | |
1592 | { | |
1593 | bb = e->src; | |
08520ad8 JL |
1594 | /* It is possible to have a non-simple jump here. Consider a target |
1595 | where some forms of unconditional jumps clobber a register. This | |
1596 | happens on the fr30 for example. | |
1597 | ||
1598 | We know this block has a single successor, so we can just emit | |
1599 | the queued insns before the jump. */ | |
e881bb1b RH |
1600 | if (GET_CODE (bb->end) == JUMP_INSN) |
1601 | { | |
e881bb1b RH |
1602 | before = bb->end; |
1603 | } | |
1604 | else | |
1605 | { | |
1606 | /* We'd better be fallthru, or we've lost track of what's what. */ | |
1607 | if ((e->flags & EDGE_FALLTHRU) == 0) | |
1608 | abort (); | |
1609 | ||
1610 | after = bb->end; | |
1611 | } | |
1612 | } | |
1613 | ||
1614 | /* Otherwise we must split the edge. */ | |
1615 | else | |
1616 | { | |
1617 | bb = split_edge (e); | |
1618 | after = bb->end; | |
1619 | } | |
1620 | ||
1621 | /* Now that we've found the spot, do the insertion. */ | |
a8688bd6 AM |
1622 | |
1623 | /* Set the new block number for these insns, if structure is allocated. */ | |
1624 | if (basic_block_for_insn) | |
1625 | { | |
1626 | rtx i; | |
19d3c25c | 1627 | for (i = insns; i != NULL_RTX; i = NEXT_INSN (i)) |
a8688bd6 AM |
1628 | set_block_for_insn (i, bb); |
1629 | } | |
1630 | ||
e881bb1b RH |
1631 | if (before) |
1632 | { | |
19d3c25c | 1633 | emit_insns_before (insns, before); |
e881bb1b | 1634 | if (before == bb->head) |
19d3c25c | 1635 | bb->head = insns; |
e881bb1b RH |
1636 | } |
1637 | else | |
1638 | { | |
19d3c25c | 1639 | rtx last = emit_insns_after (insns, after); |
e881bb1b | 1640 | if (after == bb->end) |
19d3c25c RH |
1641 | { |
1642 | bb->end = last; | |
1643 | ||
1644 | if (GET_CODE (last) == JUMP_INSN) | |
1645 | { | |
1646 | if (returnjump_p (last)) | |
1647 | { | |
1648 | /* ??? Remove all outgoing edges from BB and add one | |
1649 | for EXIT. This is not currently a problem because | |
1650 | this only happens for the (single) epilogue, which | |
1651 | already has a fallthru edge to EXIT. */ | |
1652 | ||
1653 | e = bb->succ; | |
1654 | if (e->dest != EXIT_BLOCK_PTR | |
1655 | || e->succ_next != NULL | |
1656 | || (e->flags & EDGE_FALLTHRU) == 0) | |
1657 | abort (); | |
1658 | e->flags &= ~EDGE_FALLTHRU; | |
1659 | ||
1660 | emit_barrier_after (last); | |
1661 | } | |
1662 | else | |
1663 | abort (); | |
1664 | } | |
1665 | } | |
e881bb1b RH |
1666 | } |
1667 | } | |
1668 | ||
1669 | /* Update the CFG for all queued instructions. */ | |
1670 | ||
1671 | void | |
1672 | commit_edge_insertions () | |
1673 | { | |
1674 | int i; | |
1675 | basic_block bb; | |
1676 | ||
19d3c25c RH |
1677 | #ifdef ENABLE_CHECKING |
1678 | verify_flow_info (); | |
1679 | #endif | |
1680 | ||
e881bb1b RH |
1681 | i = -1; |
1682 | bb = ENTRY_BLOCK_PTR; | |
1683 | while (1) | |
1684 | { | |
1685 | edge e, next; | |
1686 | ||
1687 | for (e = bb->succ; e ; e = next) | |
1688 | { | |
1689 | next = e->succ_next; | |
1690 | if (e->insns) | |
1691 | commit_one_edge_insertion (e); | |
1692 | } | |
1693 | ||
1694 | if (++i >= n_basic_blocks) | |
1695 | break; | |
1696 | bb = BASIC_BLOCK (i); | |
1697 | } | |
1698 | } | |
1699 | \f | |
1700 | /* Delete all unreachable basic blocks. */ | |
1701 | ||
1702 | static void | |
1703 | delete_unreachable_blocks () | |
1704 | { | |
1705 | basic_block *worklist, *tos; | |
1706 | int deleted_handler; | |
1707 | edge e; | |
1708 | int i, n; | |
1709 | ||
1710 | n = n_basic_blocks; | |
67289ea6 | 1711 | tos = worklist = (basic_block *) xmalloc (sizeof (basic_block) * n); |
e881bb1b RH |
1712 | |
1713 | /* Use basic_block->aux as a marker. Clear them all. */ | |
1714 | ||
1715 | for (i = 0; i < n; ++i) | |
1716 | BASIC_BLOCK (i)->aux = NULL; | |
1717 | ||
1718 | /* Add our starting points to the worklist. Almost always there will | |
1719 | be only one. It isn't inconcievable that we might one day directly | |
1720 | support Fortran alternate entry points. */ | |
1721 | ||
1722 | for (e = ENTRY_BLOCK_PTR->succ; e ; e = e->succ_next) | |
aa3d4bf9 RH |
1723 | { |
1724 | *tos++ = e->dest; | |
1725 | ||
1726 | /* Mark the block with a handy non-null value. */ | |
1727 | e->dest->aux = e; | |
1728 | } | |
e881bb1b RH |
1729 | |
1730 | /* Iterate: find everything reachable from what we've already seen. */ | |
1731 | ||
1732 | while (tos != worklist) | |
1733 | { | |
1734 | basic_block b = *--tos; | |
1735 | ||
e881bb1b RH |
1736 | for (e = b->succ; e ; e = e->succ_next) |
1737 | if (!e->dest->aux) | |
aa3d4bf9 RH |
1738 | { |
1739 | *tos++ = e->dest; | |
1740 | e->dest->aux = e; | |
1741 | } | |
e881bb1b RH |
1742 | } |
1743 | ||
1744 | /* Delete all unreachable basic blocks. Count down so that we don't | |
1745 | interfere with the block renumbering that happens in delete_block. */ | |
1746 | ||
1747 | deleted_handler = 0; | |
1748 | ||
1749 | for (i = n - 1; i >= 0; --i) | |
1750 | { | |
1751 | basic_block b = BASIC_BLOCK (i); | |
1752 | ||
1753 | if (b->aux != NULL) | |
1754 | /* This block was found. Tidy up the mark. */ | |
1755 | b->aux = NULL; | |
1756 | else | |
1757 | deleted_handler |= delete_block (b); | |
1758 | } | |
1759 | ||
5568fb48 | 1760 | tidy_fallthru_edges (); |
e881bb1b | 1761 | |
e881bb1b RH |
1762 | /* If we deleted an exception handler, we may have EH region begin/end |
1763 | blocks to remove as well. */ | |
1764 | if (deleted_handler) | |
1765 | delete_eh_regions (); | |
67289ea6 MM |
1766 | |
1767 | free (worklist); | |
e881bb1b RH |
1768 | } |
1769 | ||
1770 | /* Find EH regions for which there is no longer a handler, and delete them. */ | |
1771 | ||
1772 | static void | |
1773 | delete_eh_regions () | |
1774 | { | |
1775 | rtx insn; | |
1776 | ||
1ef1bf06 AM |
1777 | update_rethrow_references (); |
1778 | ||
e881bb1b RH |
1779 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) |
1780 | if (GET_CODE (insn) == NOTE) | |
1781 | { | |
1782 | if ((NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG) || | |
1783 | (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)) | |
1784 | { | |
ef178af3 | 1785 | int num = NOTE_EH_HANDLER (insn); |
1ef1bf06 | 1786 | /* A NULL handler indicates a region is no longer needed, |
6814a8a0 | 1787 | as long as its rethrow label isn't used. */ |
1ef1bf06 | 1788 | if (get_first_handler (num) == NULL && ! rethrow_used (num)) |
e881bb1b RH |
1789 | { |
1790 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
1791 | NOTE_SOURCE_FILE (insn) = 0; | |
1792 | } | |
1793 | } | |
1794 | } | |
1795 | } | |
1796 | ||
1797 | /* Return true if NOTE is not one of the ones that must be kept paired, | |
1798 | so that we may simply delete them. */ | |
1799 | ||
1800 | static int | |
eeea333e | 1801 | can_delete_note_p (note) |
e881bb1b RH |
1802 | rtx note; |
1803 | { | |
1804 | return (NOTE_LINE_NUMBER (note) == NOTE_INSN_DELETED | |
1805 | || NOTE_LINE_NUMBER (note) == NOTE_INSN_BASIC_BLOCK); | |
1806 | } | |
1807 | ||
1808 | /* Unlink a chain of insns between START and FINISH, leaving notes | |
1809 | that must be paired. */ | |
1810 | ||
d3a923ee | 1811 | void |
5aabad00 | 1812 | flow_delete_insn_chain (start, finish) |
e881bb1b RH |
1813 | rtx start, finish; |
1814 | { | |
1815 | /* Unchain the insns one by one. It would be quicker to delete all | |
1816 | of these with a single unchaining, rather than one at a time, but | |
1817 | we need to keep the NOTE's. */ | |
1818 | ||
1819 | rtx next; | |
1820 | ||
1821 | while (1) | |
1822 | { | |
1823 | next = NEXT_INSN (start); | |
eeea333e RH |
1824 | if (GET_CODE (start) == NOTE && !can_delete_note_p (start)) |
1825 | ; | |
1826 | else if (GET_CODE (start) == CODE_LABEL && !can_delete_label_p (start)) | |
1827 | ; | |
1828 | else | |
e881bb1b RH |
1829 | next = flow_delete_insn (start); |
1830 | ||
1831 | if (start == finish) | |
1832 | break; | |
1833 | start = next; | |
1834 | } | |
1835 | } | |
1836 | ||
1837 | /* Delete the insns in a (non-live) block. We physically delete every | |
1838 | non-deleted-note insn, and update the flow graph appropriately. | |
1839 | ||
1840 | Return nonzero if we deleted an exception handler. */ | |
1841 | ||
1842 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
1843 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
1844 | ||
1845 | static int | |
1846 | delete_block (b) | |
1847 | basic_block b; | |
1848 | { | |
1849 | int deleted_handler = 0; | |
1519ae2c | 1850 | rtx insn, end, tmp; |
e881bb1b RH |
1851 | |
1852 | /* If the head of this block is a CODE_LABEL, then it might be the | |
1853 | label for an exception handler which can't be reached. | |
1854 | ||
1855 | We need to remove the label from the exception_handler_label list | |
3ad47811 MM |
1856 | and remove the associated NOTE_INSN_EH_REGION_BEG and |
1857 | NOTE_INSN_EH_REGION_END notes. */ | |
e881bb1b RH |
1858 | |
1859 | insn = b->head; | |
088e7160 | 1860 | |
312f6255 GK |
1861 | never_reached_warning (insn); |
1862 | ||
e881bb1b RH |
1863 | if (GET_CODE (insn) == CODE_LABEL) |
1864 | { | |
1865 | rtx x, *prev = &exception_handler_labels; | |
1866 | ||
1867 | for (x = exception_handler_labels; x; x = XEXP (x, 1)) | |
1868 | { | |
1869 | if (XEXP (x, 0) == insn) | |
1870 | { | |
1871 | /* Found a match, splice this label out of the EH label list. */ | |
1872 | *prev = XEXP (x, 1); | |
1873 | XEXP (x, 1) = NULL_RTX; | |
1874 | XEXP (x, 0) = NULL_RTX; | |
1875 | ||
1876 | /* Remove the handler from all regions */ | |
1877 | remove_handler (insn); | |
1878 | deleted_handler = 1; | |
1879 | break; | |
1880 | } | |
1881 | prev = &XEXP (x, 1); | |
1882 | } | |
1883 | ||
1884 | /* This label may be referenced by code solely for its value, or | |
1885 | referenced by static data, or something. We have determined | |
1886 | that it is not reachable, but cannot delete the label itself. | |
1887 | Save code space and continue to delete the balance of the block, | |
1888 | along with properly updating the cfg. */ | |
1889 | if (!can_delete_label_p (insn)) | |
1890 | { | |
1891 | /* If we've only got one of these, skip the whole deleting | |
1892 | insns thing. */ | |
1893 | if (insn == b->end) | |
1894 | goto no_delete_insns; | |
1895 | insn = NEXT_INSN (insn); | |
1896 | } | |
1897 | } | |
1898 | ||
1519ae2c RH |
1899 | /* Include any jump table following the basic block. */ |
1900 | end = b->end; | |
1901 | if (GET_CODE (end) == JUMP_INSN | |
1902 | && (tmp = JUMP_LABEL (end)) != NULL_RTX | |
1903 | && (tmp = NEXT_INSN (tmp)) != NULL_RTX | |
1904 | && GET_CODE (tmp) == JUMP_INSN | |
1905 | && (GET_CODE (PATTERN (tmp)) == ADDR_VEC | |
1906 | || GET_CODE (PATTERN (tmp)) == ADDR_DIFF_VEC)) | |
1907 | end = tmp; | |
1908 | ||
1909 | /* Include any barrier that may follow the basic block. */ | |
1fa4609a | 1910 | tmp = next_nonnote_insn (end); |
1519ae2c RH |
1911 | if (tmp && GET_CODE (tmp) == BARRIER) |
1912 | end = tmp; | |
1913 | ||
1914 | /* Selectively delete the entire chain. */ | |
5aabad00 | 1915 | flow_delete_insn_chain (insn, end); |
e881bb1b | 1916 | |
d3a923ee | 1917 | no_delete_insns: |
e881bb1b RH |
1918 | |
1919 | /* Remove the edges into and out of this block. Note that there may | |
1920 | indeed be edges in, if we are removing an unreachable loop. */ | |
1921 | { | |
1922 | edge e, next, *q; | |
1923 | ||
1924 | for (e = b->pred; e ; e = next) | |
1925 | { | |
1926 | for (q = &e->src->succ; *q != e; q = &(*q)->succ_next) | |
1927 | continue; | |
1928 | *q = e->succ_next; | |
1929 | next = e->pred_next; | |
d3a923ee | 1930 | n_edges--; |
e881bb1b RH |
1931 | free (e); |
1932 | } | |
1933 | for (e = b->succ; e ; e = next) | |
1934 | { | |
1935 | for (q = &e->dest->pred; *q != e; q = &(*q)->pred_next) | |
1936 | continue; | |
1937 | *q = e->pred_next; | |
1938 | next = e->succ_next; | |
d3a923ee | 1939 | n_edges--; |
e881bb1b RH |
1940 | free (e); |
1941 | } | |
1942 | ||
1943 | b->pred = NULL; | |
1944 | b->succ = NULL; | |
1945 | } | |
1946 | ||
1947 | /* Remove the basic block from the array, and compact behind it. */ | |
1948 | expunge_block (b); | |
1949 | ||
1950 | return deleted_handler; | |
1951 | } | |
1952 | ||
1953 | /* Remove block B from the basic block array and compact behind it. */ | |
1954 | ||
1955 | static void | |
1956 | expunge_block (b) | |
1957 | basic_block b; | |
1958 | { | |
1959 | int i, n = n_basic_blocks; | |
1960 | ||
1961 | for (i = b->index; i + 1 < n; ++i) | |
1962 | { | |
1963 | basic_block x = BASIC_BLOCK (i + 1); | |
1964 | BASIC_BLOCK (i) = x; | |
1965 | x->index = i; | |
1966 | } | |
1967 | ||
1968 | basic_block_info->num_elements--; | |
1969 | n_basic_blocks--; | |
1970 | } | |
1971 | ||
1972 | /* Delete INSN by patching it out. Return the next insn. */ | |
1973 | ||
69732dcb | 1974 | rtx |
e881bb1b RH |
1975 | flow_delete_insn (insn) |
1976 | rtx insn; | |
1977 | { | |
1978 | rtx prev = PREV_INSN (insn); | |
1979 | rtx next = NEXT_INSN (insn); | |
1519ae2c | 1980 | rtx note; |
e881bb1b RH |
1981 | |
1982 | PREV_INSN (insn) = NULL_RTX; | |
1983 | NEXT_INSN (insn) = NULL_RTX; | |
1984 | ||
1985 | if (prev) | |
1986 | NEXT_INSN (prev) = next; | |
1987 | if (next) | |
1988 | PREV_INSN (next) = prev; | |
1989 | else | |
1990 | set_last_insn (prev); | |
e6cfb550 | 1991 | |
55a98783 JL |
1992 | if (GET_CODE (insn) == CODE_LABEL) |
1993 | remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels); | |
1994 | ||
e881bb1b RH |
1995 | /* If deleting a jump, decrement the use count of the label. Deleting |
1996 | the label itself should happen in the normal course of block merging. */ | |
1997 | if (GET_CODE (insn) == JUMP_INSN && JUMP_LABEL (insn)) | |
1998 | LABEL_NUSES (JUMP_LABEL (insn))--; | |
1999 | ||
1519ae2c RH |
2000 | /* Also if deleting an insn that references a label. */ |
2001 | else if ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)) != NULL_RTX) | |
2002 | LABEL_NUSES (XEXP (note, 0))--; | |
2003 | ||
e881bb1b | 2004 | return next; |
d7429b6a | 2005 | } |
8329b5ec | 2006 | |
e881bb1b RH |
2007 | /* True if a given label can be deleted. */ |
2008 | ||
2009 | static int | |
2010 | can_delete_label_p (label) | |
2011 | rtx label; | |
dc2ede84 | 2012 | { |
e881bb1b | 2013 | rtx x; |
dc2ede84 | 2014 | |
e881bb1b RH |
2015 | if (LABEL_PRESERVE_P (label)) |
2016 | return 0; | |
421382ac | 2017 | |
e881bb1b RH |
2018 | for (x = forced_labels; x ; x = XEXP (x, 1)) |
2019 | if (label == XEXP (x, 0)) | |
2020 | return 0; | |
2021 | for (x = label_value_list; x ; x = XEXP (x, 1)) | |
2022 | if (label == XEXP (x, 0)) | |
2023 | return 0; | |
2024 | for (x = exception_handler_labels; x ; x = XEXP (x, 1)) | |
2025 | if (label == XEXP (x, 0)) | |
2026 | return 0; | |
dc2ede84 | 2027 | |
abb3f0a9 | 2028 | /* User declared labels must be preserved. */ |
088e7160 | 2029 | if (LABEL_NAME (label) != 0) |
abb3f0a9 | 2030 | return 0; |
088e7160 | 2031 | |
e881bb1b RH |
2032 | return 1; |
2033 | } | |
421382ac | 2034 | |
558389e3 JL |
2035 | /* Blocks A and B are to be merged into a single block. A has no incoming |
2036 | fallthru edge, so it can be moved before B without adding or modifying | |
2037 | any jumps (aside from the jump from A to B). */ | |
2038 | ||
2039 | static int | |
336a6399 | 2040 | merge_blocks_move_predecessor_nojumps (a, b) |
558389e3 JL |
2041 | basic_block a, b; |
2042 | { | |
93cba993 | 2043 | rtx start, end, barrier; |
ee7b8369 | 2044 | int index; |
558389e3 JL |
2045 | |
2046 | start = a->head; | |
2047 | end = a->end; | |
558389e3 JL |
2048 | |
2049 | /* We want to delete the BARRIER after the end of the insns we are | |
2050 | going to move. If we don't find a BARRIER, then do nothing. This | |
2051 | can happen in some cases if we have labels we can not delete. | |
2052 | ||
2053 | Similarly, do nothing if we can not delete the label at the start | |
2054 | of the target block. */ | |
2055 | barrier = next_nonnote_insn (end); | |
2056 | if (GET_CODE (barrier) != BARRIER | |
2057 | || (GET_CODE (b->head) == CODE_LABEL | |
2058 | && ! can_delete_label_p (b->head))) | |
2059 | return 0; | |
2060 | else | |
2061 | flow_delete_insn (barrier); | |
2062 | ||
2063 | /* Move block and loop notes out of the chain so that we do not | |
2064 | disturb their order. | |
2065 | ||
2066 | ??? A better solution would be to squeeze out all the non-nested notes | |
2067 | and adjust the block trees appropriately. Even better would be to have | |
2068 | a tighter connection between block trees and rtl so that this is not | |
2069 | necessary. */ | |
2070 | start = squeeze_notes (start, end); | |
2071 | ||
2072 | /* Scramble the insn chain. */ | |
93cba993 RH |
2073 | if (end != PREV_INSN (b->head)) |
2074 | reorder_insns (start, end, PREV_INSN (b->head)); | |
558389e3 | 2075 | |
336a6399 RH |
2076 | if (rtl_dump_file) |
2077 | { | |
2078 | fprintf (rtl_dump_file, "Moved block %d before %d and merged.\n", | |
2079 | a->index, b->index); | |
2080 | } | |
2081 | ||
ee7b8369 RE |
2082 | /* Swap the records for the two blocks around. Although we are deleting B, |
2083 | A is now where B was and we want to compact the BB array from where | |
2084 | A used to be. */ | |
2085 | BASIC_BLOCK(a->index) = b; | |
2086 | BASIC_BLOCK(b->index) = a; | |
2087 | index = a->index; | |
2088 | a->index = b->index; | |
2089 | b->index = index; | |
2090 | ||
2091 | /* Now blocks A and B are contiguous. Merge them. */ | |
2092 | merge_blocks_nomove (a, b); | |
2093 | ||
558389e3 JL |
2094 | return 1; |
2095 | } | |
2096 | ||
2097 | /* Blocks A and B are to be merged into a single block. B has no outgoing | |
2098 | fallthru edge, so it can be moved after A without adding or modifying | |
2099 | any jumps (aside from the jump from A to B). */ | |
2100 | ||
2101 | static int | |
336a6399 | 2102 | merge_blocks_move_successor_nojumps (a, b) |
558389e3 JL |
2103 | basic_block a, b; |
2104 | { | |
93cba993 | 2105 | rtx start, end, barrier; |
558389e3 JL |
2106 | |
2107 | start = b->head; | |
2108 | end = b->end; | |
558389e3 | 2109 | |
8288909f | 2110 | /* We want to delete the BARRIER after the end of the insns we are |
558389e3 | 2111 | going to move. If we don't find a BARRIER, then do nothing. This |
8288909f JL |
2112 | can happen in some cases if we have labels we can not delete. |
2113 | ||
2114 | Similarly, do nothing if we can not delete the label at the start | |
2115 | of the target block. */ | |
2116 | barrier = next_nonnote_insn (end); | |
558389e3 JL |
2117 | if (GET_CODE (barrier) != BARRIER |
2118 | || (GET_CODE (b->head) == CODE_LABEL | |
2119 | && ! can_delete_label_p (b->head))) | |
2120 | return 0; | |
2121 | else | |
2122 | flow_delete_insn (barrier); | |
2123 | ||
2124 | /* Move block and loop notes out of the chain so that we do not | |
2125 | disturb their order. | |
2126 | ||
2127 | ??? A better solution would be to squeeze out all the non-nested notes | |
2128 | and adjust the block trees appropriately. Even better would be to have | |
2129 | a tighter connection between block trees and rtl so that this is not | |
2130 | necessary. */ | |
2131 | start = squeeze_notes (start, end); | |
2132 | ||
2133 | /* Scramble the insn chain. */ | |
93cba993 | 2134 | reorder_insns (start, end, a->end); |
558389e3 JL |
2135 | |
2136 | /* Now blocks A and B are contiguous. Merge them. */ | |
2137 | merge_blocks_nomove (a, b); | |
336a6399 RH |
2138 | |
2139 | if (rtl_dump_file) | |
2140 | { | |
2141 | fprintf (rtl_dump_file, "Moved block %d after %d and merged.\n", | |
2142 | b->index, a->index); | |
2143 | } | |
2144 | ||
558389e3 JL |
2145 | return 1; |
2146 | } | |
2147 | ||
e881bb1b RH |
2148 | /* Blocks A and B are to be merged into a single block. The insns |
2149 | are already contiguous, hence `nomove'. */ | |
421382ac | 2150 | |
e881bb1b RH |
2151 | static void |
2152 | merge_blocks_nomove (a, b) | |
2153 | basic_block a, b; | |
2154 | { | |
2155 | edge e; | |
f5c14c21 RH |
2156 | rtx b_head, b_end, a_end; |
2157 | int b_empty = 0; | |
2158 | ||
2159 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
2160 | b_head = b->head; | |
2161 | b_end = b->end; | |
2162 | if (GET_CODE (b_head) == CODE_LABEL) | |
2163 | { | |
2164 | /* Detect basic blocks with nothing but a label. This can happen | |
2165 | in particular at the end of a function. */ | |
2166 | if (b_head == b_end) | |
2167 | b_empty = 1; | |
2168 | b_head = flow_delete_insn (b_head); | |
2169 | } | |
2170 | ||
2171 | /* Delete the basic block note. */ | |
2172 | if (GET_CODE (b_head) == NOTE | |
2173 | && NOTE_LINE_NUMBER (b_head) == NOTE_INSN_BASIC_BLOCK) | |
2174 | { | |
2175 | if (b_head == b_end) | |
2176 | b_empty = 1; | |
2177 | b_head = flow_delete_insn (b_head); | |
2178 | } | |
421382ac | 2179 | |
e881bb1b | 2180 | /* If there was a jump out of A, delete it. */ |
f5c14c21 RH |
2181 | a_end = a->end; |
2182 | if (GET_CODE (a_end) == JUMP_INSN) | |
e881bb1b | 2183 | { |
f5c14c21 | 2184 | rtx prev; |
86879c21 | 2185 | |
f5c14c21 RH |
2186 | prev = prev_nonnote_insn (a_end); |
2187 | if (!prev) | |
2188 | prev = a->head; | |
86879c21 JL |
2189 | |
2190 | #ifdef HAVE_cc0 | |
f5c14c21 RH |
2191 | /* If this was a conditional jump, we need to also delete |
2192 | the insn that set cc0. */ | |
86879c21 | 2193 | |
f5c14c21 RH |
2194 | if (prev && sets_cc0_p (prev)) |
2195 | { | |
2196 | rtx tmp = prev; | |
2197 | prev = prev_nonnote_insn (prev); | |
2198 | if (!prev) | |
2199 | prev = a->head; | |
e881bb1b | 2200 | flow_delete_insn (tmp); |
421382ac | 2201 | } |
f5c14c21 RH |
2202 | #endif |
2203 | ||
2204 | /* Note that a->head != a->end, since we should have at least a | |
2205 | bb note plus the jump, so prev != insn. */ | |
2206 | flow_delete_insn (a_end); | |
2207 | a_end = prev; | |
421382ac | 2208 | } |
421382ac | 2209 | |
e881bb1b RH |
2210 | /* By definition, there should only be one successor of A, and that is |
2211 | B. Free that edge struct. */ | |
d3a923ee | 2212 | n_edges--; |
e881bb1b RH |
2213 | free (a->succ); |
2214 | ||
2215 | /* Adjust the edges out of B for the new owner. */ | |
2216 | for (e = b->succ; e ; e = e->succ_next) | |
2217 | e->src = a; | |
2218 | a->succ = b->succ; | |
2219 | ||
e881bb1b | 2220 | /* Reassociate the insns of B with A. */ |
f5c14c21 | 2221 | if (!b_empty) |
e881bb1b | 2222 | { |
f5c14c21 RH |
2223 | BLOCK_FOR_INSN (b_head) = a; |
2224 | while (b_head != b_end) | |
dc2ede84 | 2225 | { |
f5c14c21 RH |
2226 | b_head = NEXT_INSN (b_head); |
2227 | BLOCK_FOR_INSN (b_head) = a; | |
dc2ede84 | 2228 | } |
f5c14c21 | 2229 | a_end = b_head; |
e881bb1b | 2230 | } |
f5c14c21 | 2231 | a->end = a_end; |
e881bb1b RH |
2232 | |
2233 | /* Compact the basic block array. */ | |
2234 | expunge_block (b); | |
dc2ede84 BS |
2235 | } |
2236 | ||
e881bb1b RH |
2237 | /* Attempt to merge basic blocks that are potentially non-adjacent. |
2238 | Return true iff the attempt succeeded. */ | |
dc2ede84 | 2239 | |
dc2ede84 | 2240 | static int |
e881bb1b RH |
2241 | merge_blocks (e, b, c) |
2242 | edge e; | |
2243 | basic_block b, c; | |
dc2ede84 | 2244 | { |
e881bb1b | 2245 | /* If B has a fallthru edge to C, no need to move anything. */ |
336a6399 | 2246 | if (e->flags & EDGE_FALLTHRU) |
e881bb1b | 2247 | { |
336a6399 RH |
2248 | /* If a label still appears somewhere and we cannot delete the label, |
2249 | then we cannot merge the blocks. The edge was tidied already. */ | |
558389e3 | 2250 | |
336a6399 RH |
2251 | rtx insn, stop = NEXT_INSN (c->head); |
2252 | for (insn = NEXT_INSN (b->end); insn != stop; insn = NEXT_INSN (insn)) | |
2253 | if (GET_CODE (insn) == CODE_LABEL && !can_delete_label_p (insn)) | |
2254 | return 0; | |
558389e3 | 2255 | |
336a6399 | 2256 | merge_blocks_nomove (b, c); |
558389e3 | 2257 | |
336a6399 RH |
2258 | if (rtl_dump_file) |
2259 | { | |
2260 | fprintf (rtl_dump_file, "Merged %d and %d without moving.\n", | |
2261 | b->index, c->index); | |
2262 | } | |
e881bb1b | 2263 | |
336a6399 RH |
2264 | return 1; |
2265 | } | |
2266 | else | |
2267 | { | |
2268 | edge tmp_edge; | |
2269 | basic_block d; | |
2270 | int c_has_outgoing_fallthru; | |
2271 | int b_has_incoming_fallthru; | |
e881bb1b | 2272 | |
336a6399 RH |
2273 | /* We must make sure to not munge nesting of exception regions, |
2274 | lexical blocks, and loop notes. | |
2275 | ||
2276 | The first is taken care of by requiring that the active eh | |
2277 | region at the end of one block always matches the active eh | |
2278 | region at the beginning of the next block. | |
2279 | ||
2280 | The later two are taken care of by squeezing out all the notes. */ | |
2281 | ||
2282 | /* ??? A throw/catch edge (or any abnormal edge) should be rarely | |
2283 | executed and we may want to treat blocks which have two out | |
2284 | edges, one normal, one abnormal as only having one edge for | |
2285 | block merging purposes. */ | |
558389e3 JL |
2286 | |
2287 | for (tmp_edge = c->succ; tmp_edge ; tmp_edge = tmp_edge->succ_next) | |
2288 | if (tmp_edge->flags & EDGE_FALLTHRU) | |
2289 | break; | |
2290 | c_has_outgoing_fallthru = (tmp_edge != NULL); | |
2291 | ||
2292 | for (tmp_edge = b->pred; tmp_edge ; tmp_edge = tmp_edge->pred_next) | |
2293 | if (tmp_edge->flags & EDGE_FALLTHRU) | |
2294 | break; | |
2295 | b_has_incoming_fallthru = (tmp_edge != NULL); | |
2296 | ||
336a6399 RH |
2297 | /* If B does not have an incoming fallthru, and the exception regions |
2298 | match, then it can be moved immediately before C without introducing | |
ff54d46b JL |
2299 | or modifying jumps. |
2300 | ||
2301 | C can not be the first block, so we do not have to worry about | |
2302 | accessing a non-existent block. */ | |
336a6399 RH |
2303 | d = BASIC_BLOCK (c->index - 1); |
2304 | if (! b_has_incoming_fallthru | |
2305 | && d->eh_end == b->eh_beg | |
2306 | && b->eh_end == c->eh_beg) | |
2307 | return merge_blocks_move_predecessor_nojumps (b, c); | |
2308 | ||
2309 | /* Otherwise, we're going to try to move C after B. Make sure the | |
ff54d46b JL |
2310 | exception regions match. |
2311 | ||
2312 | If B is the last basic block, then we must not try to access the | |
2313 | block structure for block B + 1. Luckily in that case we do not | |
2314 | need to worry about matching exception regions. */ | |
2315 | d = (b->index + 1 < n_basic_blocks ? BASIC_BLOCK (b->index + 1) : NULL); | |
336a6399 | 2316 | if (b->eh_end == c->eh_beg |
ff54d46b | 2317 | && (d == NULL || c->eh_end == d->eh_beg)) |
336a6399 RH |
2318 | { |
2319 | /* If C does not have an outgoing fallthru, then it can be moved | |
2320 | immediately after B without introducing or modifying jumps. */ | |
2321 | if (! c_has_outgoing_fallthru) | |
2322 | return merge_blocks_move_successor_nojumps (b, c); | |
2323 | ||
2324 | /* Otherwise, we'll need to insert an extra jump, and possibly | |
2325 | a new block to contain it. */ | |
2326 | /* ??? Not implemented yet. */ | |
2327 | } | |
558389e3 | 2328 | |
336a6399 | 2329 | return 0; |
e881bb1b | 2330 | } |
336a6399 | 2331 | } |
dc2ede84 | 2332 | |
336a6399 | 2333 | /* Top level driver for merge_blocks. */ |
421382ac | 2334 | |
336a6399 RH |
2335 | static void |
2336 | try_merge_blocks () | |
2337 | { | |
2338 | int i; | |
2339 | ||
2340 | /* Attempt to merge blocks as made possible by edge removal. If a block | |
2341 | has only one successor, and the successor has only one predecessor, | |
2342 | they may be combined. */ | |
2343 | ||
2344 | for (i = 0; i < n_basic_blocks; ) | |
2345 | { | |
2346 | basic_block c, b = BASIC_BLOCK (i); | |
2347 | edge s; | |
2348 | ||
2349 | /* A loop because chains of blocks might be combineable. */ | |
2350 | while ((s = b->succ) != NULL | |
2351 | && s->succ_next == NULL | |
2352 | && (s->flags & EDGE_EH) == 0 | |
2353 | && (c = s->dest) != EXIT_BLOCK_PTR | |
2354 | && c->pred->pred_next == NULL | |
2355 | /* If the jump insn has side effects, we can't kill the edge. */ | |
2356 | && (GET_CODE (b->end) != JUMP_INSN | |
2357 | || onlyjump_p (b->end)) | |
2358 | && merge_blocks (s, b, c)) | |
2359 | continue; | |
2360 | ||
2361 | /* Don't get confused by the index shift caused by deleting blocks. */ | |
2362 | i = b->index + 1; | |
2363 | } | |
e881bb1b | 2364 | } |
421382ac | 2365 | |
5568fb48 RH |
2366 | /* The given edge should potentially be a fallthru edge. If that is in |
2367 | fact true, delete the jump and barriers that are in the way. */ | |
e881bb1b RH |
2368 | |
2369 | static void | |
2370 | tidy_fallthru_edge (e, b, c) | |
2371 | edge e; | |
2372 | basic_block b, c; | |
2373 | { | |
eeea333e | 2374 | rtx q; |
e881bb1b RH |
2375 | |
2376 | /* ??? In a late-running flow pass, other folks may have deleted basic | |
2377 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
2378 | and the target label. They ought to be chastized and fixed. | |
2379 | ||
eeea333e RH |
2380 | We can also wind up with a sequence of undeletable labels between |
2381 | one block and the next. | |
dc2ede84 | 2382 | |
eeea333e RH |
2383 | So search through a sequence of barriers, labels, and notes for |
2384 | the head of block C and assert that we really do fall through. */ | |
421382ac | 2385 | |
eeea333e | 2386 | if (next_real_insn (b->end) != next_real_insn (PREV_INSN (c->head))) |
e881bb1b | 2387 | return; |
421382ac | 2388 | |
e881bb1b RH |
2389 | /* Remove what will soon cease being the jump insn from the source block. |
2390 | If block B consisted only of this single jump, turn it into a deleted | |
2391 | note. */ | |
2392 | q = b->end; | |
2393 | if (GET_CODE (q) == JUMP_INSN) | |
421382ac | 2394 | { |
86a1db60 RH |
2395 | #ifdef HAVE_cc0 |
2396 | /* If this was a conditional jump, we need to also delete | |
2397 | the insn that set cc0. */ | |
b30f05db | 2398 | if (! simplejump_p (q) && condjump_p (q) && sets_cc0_p (PREV_INSN (q))) |
86a1db60 RH |
2399 | q = PREV_INSN (q); |
2400 | #endif | |
2401 | ||
e881bb1b RH |
2402 | if (b->head == q) |
2403 | { | |
2404 | PUT_CODE (q, NOTE); | |
2405 | NOTE_LINE_NUMBER (q) = NOTE_INSN_DELETED; | |
2406 | NOTE_SOURCE_FILE (q) = 0; | |
2407 | } | |
e3f6ee23 | 2408 | else |
e881bb1b | 2409 | b->end = q = PREV_INSN (q); |
421382ac | 2410 | } |
421382ac | 2411 | |
e881bb1b | 2412 | /* Selectively unlink the sequence. */ |
86a1db60 | 2413 | if (q != PREV_INSN (c->head)) |
5aabad00 | 2414 | flow_delete_insn_chain (NEXT_INSN (q), PREV_INSN (c->head)); |
b7f7462b | 2415 | |
e881bb1b RH |
2416 | e->flags |= EDGE_FALLTHRU; |
2417 | } | |
dc2ede84 | 2418 | |
5568fb48 RH |
2419 | /* Fix up edges that now fall through, or rather should now fall through |
2420 | but previously required a jump around now deleted blocks. Simplify | |
2421 | the search by only examining blocks numerically adjacent, since this | |
2422 | is how find_basic_blocks created them. */ | |
2423 | ||
2424 | static void | |
2425 | tidy_fallthru_edges () | |
2426 | { | |
2427 | int i; | |
2428 | ||
2429 | for (i = 1; i < n_basic_blocks; ++i) | |
2430 | { | |
2431 | basic_block b = BASIC_BLOCK (i - 1); | |
2432 | basic_block c = BASIC_BLOCK (i); | |
2433 | edge s; | |
2434 | ||
2435 | /* We care about simple conditional or unconditional jumps with | |
2436 | a single successor. | |
2437 | ||
2438 | If we had a conditional branch to the next instruction when | |
2439 | find_basic_blocks was called, then there will only be one | |
2440 | out edge for the block which ended with the conditional | |
2441 | branch (since we do not create duplicate edges). | |
2442 | ||
2443 | Furthermore, the edge will be marked as a fallthru because we | |
2444 | merge the flags for the duplicate edges. So we do not want to | |
2445 | check that the edge is not a FALLTHRU edge. */ | |
2446 | if ((s = b->succ) != NULL | |
2447 | && s->succ_next == NULL | |
2448 | && s->dest == c | |
2449 | /* If the jump insn has side effects, we can't tidy the edge. */ | |
2450 | && (GET_CODE (b->end) != JUMP_INSN | |
2451 | || onlyjump_p (b->end))) | |
2452 | tidy_fallthru_edge (s, b, c); | |
2453 | } | |
2454 | } | |
2455 | ||
e881bb1b RH |
2456 | /* Discover and record the loop depth at the head of each basic block. */ |
2457 | ||
35836a43 JH |
2458 | void |
2459 | calculate_loop_depth (dump) | |
2460 | FILE *dump; | |
e881bb1b | 2461 | { |
35836a43 | 2462 | struct loops loops; |
dc2ede84 | 2463 | |
35836a43 JH |
2464 | /* The loop infrastructure does the real job for us. */ |
2465 | flow_loops_find (&loops); | |
d4b60170 | 2466 | |
35836a43 JH |
2467 | if (dump) |
2468 | flow_loops_dump (&loops, dump, 0); | |
d4b60170 | 2469 | |
35836a43 | 2470 | flow_loops_free (&loops); |
dc2ede84 | 2471 | } |
d7429b6a | 2472 | \f |
5ece9746 JL |
2473 | /* Perform data flow analysis. |
2474 | F is the first insn of the function and NREGS the number of register numbers | |
2475 | in use. */ | |
2476 | ||
2477 | void | |
11f246f6 | 2478 | life_analysis (f, nregs, file, remove_dead_code) |
5ece9746 JL |
2479 | rtx f; |
2480 | int nregs; | |
2481 | FILE *file; | |
11f246f6 | 2482 | int remove_dead_code; |
5ece9746 | 2483 | { |
5ece9746 | 2484 | #ifdef ELIMINABLE_REGS |
47ee9bcb | 2485 | register int i; |
5ece9746 JL |
2486 | static struct {int from, to; } eliminables[] = ELIMINABLE_REGS; |
2487 | #endif | |
d3a923ee | 2488 | int flags; |
3ea8083f | 2489 | sbitmap all_blocks; |
4e872036 AS |
2490 | |
2491 | /* Dead code elimination changes basic block structure and therefore | |
2492 | breaks the SSA phi representation. Particularly, a phi node | |
2493 | can have an alternative value for each incoming block, referenced | |
2494 | by the block number. Removing dead code can bump entire blocks | |
2495 | and therefore cause blocks to be renumbered, invalidating the | |
2496 | numbering of phi alternatives. */ | |
2497 | if (remove_dead_code && in_ssa_form) | |
2498 | abort (); | |
3ea8083f | 2499 | |
5ece9746 JL |
2500 | /* Record which registers will be eliminated. We use this in |
2501 | mark_used_regs. */ | |
2502 | ||
2503 | CLEAR_HARD_REG_SET (elim_reg_set); | |
2504 | ||
2505 | #ifdef ELIMINABLE_REGS | |
3ea8083f | 2506 | for (i = 0; i < (int) (sizeof eliminables / sizeof eliminables[0]); i++) |
5ece9746 JL |
2507 | SET_HARD_REG_BIT (elim_reg_set, eliminables[i].from); |
2508 | #else | |
2509 | SET_HARD_REG_BIT (elim_reg_set, FRAME_POINTER_REGNUM); | |
2510 | #endif | |
2511 | ||
db3a887b CB |
2512 | /* We want alias analysis information for local dead store elimination. */ |
2513 | init_alias_analysis (); | |
7790df19 | 2514 | |
d29c259b RH |
2515 | if (! optimize) |
2516 | flags = PROP_DEATH_NOTES | PROP_REG_INFO; | |
2517 | else | |
2518 | { | |
2519 | flags = PROP_FINAL; | |
2520 | if (! remove_dead_code) | |
2521 | flags &= ~(PROP_SCAN_DEAD_CODE | PROP_KILL_DEAD_CODE); | |
2522 | } | |
7790df19 | 2523 | |
3ea8083f JL |
2524 | /* The post-reload life analysis have (on a global basis) the same |
2525 | registers live as was computed by reload itself. elimination | |
2526 | Otherwise offsets and such may be incorrect. | |
2527 | ||
2528 | Reload will make some registers as live even though they do not | |
2529 | appear in the rtl. */ | |
2530 | if (reload_completed) | |
2531 | flags &= ~PROP_REG_INFO; | |
2532 | ||
2533 | max_regno = nregs; | |
2534 | ||
2535 | /* Always remove no-op moves. Do this before other processing so | |
2536 | that we don't have to keep re-scanning them. */ | |
2537 | delete_noop_moves (f); | |
2538 | ||
2539 | /* Some targets can emit simpler epilogues if they know that sp was | |
2540 | not ever modified during the function. After reload, of course, | |
2541 | we've already emitted the epilogue so there's no sense searching. */ | |
7790df19 | 2542 | if (! reload_completed) |
3ea8083f JL |
2543 | notice_stack_pointer_modification (f); |
2544 | ||
2545 | /* Allocate and zero out data structures that will record the | |
2546 | data from lifetime analysis. */ | |
2547 | allocate_reg_life_data (); | |
2548 | allocate_bb_life_data (); | |
2549 | reg_next_use = (rtx *) xcalloc (nregs, sizeof (rtx)); | |
2550 | all_blocks = sbitmap_alloc (n_basic_blocks); | |
2551 | sbitmap_ones (all_blocks); | |
7790df19 | 2552 | |
3ea8083f JL |
2553 | /* Find the set of registers live on function exit. */ |
2554 | mark_regs_live_at_end (EXIT_BLOCK_PTR->global_live_at_start); | |
2555 | ||
2556 | /* "Update" life info from zero. It'd be nice to begin the | |
2557 | relaxation with just the exit and noreturn blocks, but that set | |
2558 | is not immediately handy. */ | |
c8082519 RH |
2559 | |
2560 | if (flags & PROP_REG_INFO) | |
2561 | memset (regs_ever_live, 0, sizeof(regs_ever_live)); | |
3ea8083f JL |
2562 | update_life_info (all_blocks, UPDATE_LIFE_GLOBAL, flags); |
2563 | ||
2564 | /* Clean up. */ | |
2565 | sbitmap_free (all_blocks); | |
2566 | free (reg_next_use); | |
2567 | reg_next_use = NULL; | |
db3a887b CB |
2568 | end_alias_analysis (); |
2569 | ||
5ece9746 JL |
2570 | if (file) |
2571 | dump_flow_info (file); | |
2572 | ||
2573 | free_basic_block_vars (1); | |
2574 | } | |
2575 | ||
d3a923ee RH |
2576 | /* A subroutine of verify_wide_reg, called through for_each_rtx. |
2577 | Search for REGNO. If found, abort if it is not wider than word_mode. */ | |
2578 | ||
2579 | static int | |
2580 | verify_wide_reg_1 (px, pregno) | |
2581 | rtx *px; | |
2582 | void *pregno; | |
2583 | { | |
2584 | rtx x = *px; | |
770ae6cc | 2585 | unsigned int regno = *(int *) pregno; |
d3a923ee RH |
2586 | |
2587 | if (GET_CODE (x) == REG && REGNO (x) == regno) | |
2588 | { | |
2589 | if (GET_MODE_BITSIZE (GET_MODE (x)) <= BITS_PER_WORD) | |
2590 | abort (); | |
2591 | return 1; | |
2592 | } | |
2593 | return 0; | |
2594 | } | |
2595 | ||
2596 | /* A subroutine of verify_local_live_at_start. Search through insns | |
2597 | between HEAD and END looking for register REGNO. */ | |
2598 | ||
2599 | static void | |
2600 | verify_wide_reg (regno, head, end) | |
2601 | int regno; | |
2602 | rtx head, end; | |
2603 | { | |
2604 | while (1) | |
2605 | { | |
2606 | if (GET_RTX_CLASS (GET_CODE (head)) == 'i' | |
2607 | && for_each_rtx (&PATTERN (head), verify_wide_reg_1, ®no)) | |
2608 | return; | |
2609 | if (head == end) | |
2610 | break; | |
2611 | head = NEXT_INSN (head); | |
2612 | } | |
2613 | ||
2614 | /* We didn't find the register at all. Something's way screwy. */ | |
2615 | abort (); | |
2616 | } | |
2617 | ||
2618 | /* A subroutine of update_life_info. Verify that there are no untoward | |
2619 | changes in live_at_start during a local update. */ | |
2620 | ||
2621 | static void | |
2622 | verify_local_live_at_start (new_live_at_start, bb) | |
2623 | regset new_live_at_start; | |
2624 | basic_block bb; | |
2625 | { | |
2626 | if (reload_completed) | |
2627 | { | |
2628 | /* After reload, there are no pseudos, nor subregs of multi-word | |
2629 | registers. The regsets should exactly match. */ | |
2630 | if (! REG_SET_EQUAL_P (new_live_at_start, bb->global_live_at_start)) | |
2631 | abort (); | |
2632 | } | |
2633 | else | |
2634 | { | |
2635 | int i; | |
2636 | ||
2637 | /* Find the set of changed registers. */ | |
2638 | XOR_REG_SET (new_live_at_start, bb->global_live_at_start); | |
2639 | ||
2640 | EXECUTE_IF_SET_IN_REG_SET (new_live_at_start, 0, i, | |
2641 | { | |
2642 | /* No registers should die. */ | |
2643 | if (REGNO_REG_SET_P (bb->global_live_at_start, i)) | |
2644 | abort (); | |
2645 | /* Verify that the now-live register is wider than word_mode. */ | |
2646 | verify_wide_reg (i, bb->head, bb->end); | |
2647 | }); | |
2648 | } | |
2649 | } | |
2650 | ||
3ea8083f | 2651 | /* Updates life information starting with the basic blocks set in BLOCKS. |
d3a923ee RH |
2652 | |
2653 | If LOCAL_ONLY, such as after splitting or peepholeing, we are only | |
2654 | expecting local modifications to basic blocks. If we find extra | |
2655 | registers live at the beginning of a block, then we either killed | |
2656 | useful data, or we have a broken split that wants data not provided. | |
2657 | If we find registers removed from live_at_start, that means we have | |
2658 | a broken peephole that is killing a register it shouldn't. | |
2659 | ||
2660 | ??? This is not true in one situation -- when a pre-reload splitter | |
2661 | generates subregs of a multi-word pseudo, current life analysis will | |
49c3bb12 RH |
2662 | lose the kill. So we _can_ have a pseudo go live. How irritating. |
2663 | ||
2664 | BLOCK_FOR_INSN is assumed to be correct. | |
2665 | ||
3ea8083f JL |
2666 | PROP_FLAGS should not contain PROP_LOG_LINKS unless the caller sets |
2667 | up reg_next_use. Including PROP_REG_INFO does not properly refresh | |
49c3bb12 | 2668 | regs_ever_live unless the caller resets it to zero. */ |
d3a923ee RH |
2669 | |
2670 | void | |
49c3bb12 | 2671 | update_life_info (blocks, extent, prop_flags) |
d3a923ee | 2672 | sbitmap blocks; |
715e7fbc | 2673 | enum update_life_extent extent; |
49c3bb12 | 2674 | int prop_flags; |
d3a923ee RH |
2675 | { |
2676 | regset tmp; | |
ee25a7a5 | 2677 | regset_head tmp_head; |
d3a923ee RH |
2678 | int i; |
2679 | ||
ee25a7a5 | 2680 | tmp = INITIALIZE_REG_SET (tmp_head); |
d3a923ee RH |
2681 | |
2682 | /* For a global update, we go through the relaxation process again. */ | |
715e7fbc RH |
2683 | if (extent != UPDATE_LIFE_LOCAL) |
2684 | { | |
49c3bb12 RH |
2685 | calculate_global_regs_live (blocks, blocks, |
2686 | prop_flags & PROP_SCAN_DEAD_CODE); | |
715e7fbc RH |
2687 | |
2688 | /* If asked, remove notes from the blocks we'll update. */ | |
2689 | if (extent == UPDATE_LIFE_GLOBAL_RM_NOTES) | |
2690 | count_or_remove_death_notes (blocks, 1); | |
2691 | } | |
d3a923ee RH |
2692 | |
2693 | EXECUTE_IF_SET_IN_SBITMAP (blocks, 0, i, | |
2694 | { | |
2695 | basic_block bb = BASIC_BLOCK (i); | |
2696 | ||
2697 | COPY_REG_SET (tmp, bb->global_live_at_end); | |
65f6fa24 | 2698 | propagate_block (bb, tmp, (regset) NULL, prop_flags); |
d3a923ee | 2699 | |
715e7fbc | 2700 | if (extent == UPDATE_LIFE_LOCAL) |
d3a923ee | 2701 | verify_local_live_at_start (tmp, bb); |
d3a923ee RH |
2702 | }); |
2703 | ||
2704 | FREE_REG_SET (tmp); | |
3ea8083f JL |
2705 | |
2706 | if (prop_flags & PROP_REG_INFO) | |
2707 | { | |
2708 | /* The only pseudos that are live at the beginning of the function | |
2709 | are those that were not set anywhere in the function. local-alloc | |
2710 | doesn't know how to handle these correctly, so mark them as not | |
2711 | local to any one basic block. */ | |
2712 | EXECUTE_IF_SET_IN_REG_SET (ENTRY_BLOCK_PTR->global_live_at_end, | |
2713 | FIRST_PSEUDO_REGISTER, i, | |
2714 | { REG_BASIC_BLOCK (i) = REG_BLOCK_GLOBAL; }); | |
2715 | ||
2716 | /* We have a problem with any pseudoreg that lives across the setjmp. | |
2717 | ANSI says that if a user variable does not change in value between | |
2718 | the setjmp and the longjmp, then the longjmp preserves it. This | |
2719 | includes longjmp from a place where the pseudo appears dead. | |
2720 | (In principle, the value still exists if it is in scope.) | |
2721 | If the pseudo goes in a hard reg, some other value may occupy | |
2722 | that hard reg where this pseudo is dead, thus clobbering the pseudo. | |
2723 | Conclusion: such a pseudo must not go in a hard reg. */ | |
2724 | EXECUTE_IF_SET_IN_REG_SET (regs_live_at_setjmp, | |
2725 | FIRST_PSEUDO_REGISTER, i, | |
2726 | { | |
2727 | if (regno_reg_rtx[i] != 0) | |
2728 | { | |
2729 | REG_LIVE_LENGTH (i) = -1; | |
2730 | REG_BASIC_BLOCK (i) = REG_BLOCK_UNKNOWN; | |
2731 | } | |
2732 | }); | |
2733 | } | |
d3a923ee RH |
2734 | } |
2735 | ||
5ece9746 JL |
2736 | /* Free the variables allocated by find_basic_blocks. |
2737 | ||
e881bb1b | 2738 | KEEP_HEAD_END_P is non-zero if basic_block_info is not to be freed. */ |
5ece9746 JL |
2739 | |
2740 | void | |
2741 | free_basic_block_vars (keep_head_end_p) | |
2742 | int keep_head_end_p; | |
2743 | { | |
e881bb1b | 2744 | if (basic_block_for_insn) |
5ece9746 | 2745 | { |
e881bb1b RH |
2746 | VARRAY_FREE (basic_block_for_insn); |
2747 | basic_block_for_insn = NULL; | |
5ece9746 JL |
2748 | } |
2749 | ||
e881bb1b | 2750 | if (! keep_head_end_p) |
5ece9746 | 2751 | { |
e881bb1b RH |
2752 | clear_edges (); |
2753 | VARRAY_FREE (basic_block_info); | |
2754 | n_basic_blocks = 0; | |
359da67d RH |
2755 | |
2756 | ENTRY_BLOCK_PTR->aux = NULL; | |
2757 | ENTRY_BLOCK_PTR->global_live_at_end = NULL; | |
2758 | EXIT_BLOCK_PTR->aux = NULL; | |
2759 | EXIT_BLOCK_PTR->global_live_at_start = NULL; | |
5ece9746 JL |
2760 | } |
2761 | } | |
2762 | ||
dc2ede84 BS |
2763 | /* Return nonzero if the destination of SET equals the source. */ |
2764 | static int | |
2765 | set_noop_p (set) | |
2766 | rtx set; | |
2767 | { | |
2768 | rtx src = SET_SRC (set); | |
2769 | rtx dst = SET_DEST (set); | |
3ea8083f JL |
2770 | |
2771 | if (GET_CODE (src) == SUBREG && GET_CODE (dst) == SUBREG) | |
2772 | { | |
2773 | if (SUBREG_WORD (src) != SUBREG_WORD (dst)) | |
2774 | return 0; | |
2775 | src = SUBREG_REG (src); | |
2776 | dst = SUBREG_REG (dst); | |
2777 | } | |
2778 | ||
2779 | return (GET_CODE (src) == REG && GET_CODE (dst) == REG | |
2780 | && REGNO (src) == REGNO (dst)); | |
dc2ede84 BS |
2781 | } |
2782 | ||
2783 | /* Return nonzero if an insn consists only of SETs, each of which only sets a | |
2784 | value to itself. */ | |
2785 | static int | |
2786 | noop_move_p (insn) | |
2787 | rtx insn; | |
2788 | { | |
2789 | rtx pat = PATTERN (insn); | |
2790 | ||
2791 | /* Insns carrying these notes are useful later on. */ | |
2792 | if (find_reg_note (insn, REG_EQUAL, NULL_RTX)) | |
2793 | return 0; | |
2794 | ||
2795 | if (GET_CODE (pat) == SET && set_noop_p (pat)) | |
2796 | return 1; | |
2797 | ||
2798 | if (GET_CODE (pat) == PARALLEL) | |
2799 | { | |
2800 | int i; | |
2801 | /* If nothing but SETs of registers to themselves, | |
2802 | this insn can also be deleted. */ | |
2803 | for (i = 0; i < XVECLEN (pat, 0); i++) | |
2804 | { | |
2805 | rtx tem = XVECEXP (pat, 0, i); | |
2806 | ||
2807 | if (GET_CODE (tem) == USE | |
2808 | || GET_CODE (tem) == CLOBBER) | |
2809 | continue; | |
2810 | ||
2811 | if (GET_CODE (tem) != SET || ! set_noop_p (tem)) | |
2812 | return 0; | |
2813 | } | |
2814 | ||
2815 | return 1; | |
2816 | } | |
2817 | return 0; | |
2818 | } | |
2819 | ||
3ea8083f JL |
2820 | /* Delete any insns that copy a register to itself. */ |
2821 | ||
2822 | static void | |
2823 | delete_noop_moves (f) | |
2824 | rtx f; | |
2825 | { | |
2826 | rtx insn; | |
2827 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
2828 | { | |
2829 | if (GET_CODE (insn) == INSN && noop_move_p (insn)) | |
2830 | { | |
2831 | PUT_CODE (insn, NOTE); | |
2832 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
2833 | NOTE_SOURCE_FILE (insn) = 0; | |
2834 | } | |
2835 | } | |
2836 | } | |
2837 | ||
2838 | /* Determine if the stack pointer is constant over the life of the function. | |
2839 | Only useful before prologues have been emitted. */ | |
2840 | ||
fdb8a883 | 2841 | static void |
3ea8083f | 2842 | notice_stack_pointer_modification_1 (x, pat, data) |
fdb8a883 JW |
2843 | rtx x; |
2844 | rtx pat ATTRIBUTE_UNUSED; | |
84832317 | 2845 | void *data ATTRIBUTE_UNUSED; |
fdb8a883 JW |
2846 | { |
2847 | if (x == stack_pointer_rtx | |
2848 | /* The stack pointer is only modified indirectly as the result | |
2849 | of a push until later in flow. See the comments in rtl.texi | |
2850 | regarding Embedded Side-Effects on Addresses. */ | |
2851 | || (GET_CODE (x) == MEM | |
2852 | && (GET_CODE (XEXP (x, 0)) == PRE_DEC | |
2853 | || GET_CODE (XEXP (x, 0)) == PRE_INC | |
2854 | || GET_CODE (XEXP (x, 0)) == POST_DEC | |
2855 | || GET_CODE (XEXP (x, 0)) == POST_INC) | |
2856 | && XEXP (XEXP (x, 0), 0) == stack_pointer_rtx)) | |
2857 | current_function_sp_is_unchanging = 0; | |
2858 | } | |
2859 | ||
dc2ede84 | 2860 | static void |
3ea8083f | 2861 | notice_stack_pointer_modification (f) |
dc2ede84 BS |
2862 | rtx f; |
2863 | { | |
2864 | rtx insn; | |
3ea8083f JL |
2865 | |
2866 | /* Assume that the stack pointer is unchanging if alloca hasn't | |
2867 | been used. */ | |
2868 | current_function_sp_is_unchanging = !current_function_calls_alloca; | |
2869 | if (! current_function_sp_is_unchanging) | |
2870 | return; | |
2871 | ||
dc2ede84 BS |
2872 | for (insn = f; insn; insn = NEXT_INSN (insn)) |
2873 | { | |
3ea8083f | 2874 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') |
dc2ede84 | 2875 | { |
3ea8083f JL |
2876 | /* Check if insn modifies the stack pointer. */ |
2877 | note_stores (PATTERN (insn), notice_stack_pointer_modification_1, | |
2878 | NULL); | |
2879 | if (! current_function_sp_is_unchanging) | |
2880 | return; | |
dc2ede84 BS |
2881 | } |
2882 | } | |
2883 | } | |
2884 | ||
d3a923ee RH |
2885 | /* Mark a register in SET. Hard registers in large modes get all |
2886 | of their component registers set as well. */ | |
2887 | static void | |
c13fde05 | 2888 | mark_reg (reg, xset) |
d3a923ee | 2889 | rtx reg; |
c13fde05 | 2890 | void *xset; |
d3a923ee | 2891 | { |
c13fde05 | 2892 | regset set = (regset) xset; |
d3a923ee RH |
2893 | int regno = REGNO (reg); |
2894 | ||
c13fde05 RH |
2895 | if (GET_MODE (reg) == BLKmode) |
2896 | abort (); | |
2897 | ||
d3a923ee RH |
2898 | SET_REGNO_REG_SET (set, regno); |
2899 | if (regno < FIRST_PSEUDO_REGISTER) | |
2900 | { | |
2901 | int n = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
2902 | while (--n > 0) | |
2903 | SET_REGNO_REG_SET (set, regno + n); | |
2904 | } | |
2905 | } | |
2906 | ||
dc2ede84 BS |
2907 | /* Mark those regs which are needed at the end of the function as live |
2908 | at the end of the last basic block. */ | |
2909 | static void | |
2910 | mark_regs_live_at_end (set) | |
2911 | regset set; | |
2912 | { | |
2913 | int i; | |
d3a923ee | 2914 | |
e881bb1b RH |
2915 | /* If exiting needs the right stack value, consider the stack pointer |
2916 | live at the end of the function. */ | |
d3a923ee RH |
2917 | if ((HAVE_epilogue && reload_completed) |
2918 | || ! EXIT_IGNORE_STACK | |
dc2ede84 BS |
2919 | || (! FRAME_POINTER_REQUIRED |
2920 | && ! current_function_calls_alloca | |
fdb8a883 JW |
2921 | && flag_omit_frame_pointer) |
2922 | || current_function_sp_is_unchanging) | |
e881bb1b RH |
2923 | { |
2924 | SET_REGNO_REG_SET (set, STACK_POINTER_REGNUM); | |
2925 | } | |
dc2ede84 | 2926 | |
e881bb1b | 2927 | /* Mark the frame pointer if needed at the end of the function. If |
dc2ede84 BS |
2928 | we end up eliminating it, it will be removed from the live list |
2929 | of each basic block by reload. */ | |
2930 | ||
e4b8a413 JW |
2931 | if (! reload_completed || frame_pointer_needed) |
2932 | { | |
2933 | SET_REGNO_REG_SET (set, FRAME_POINTER_REGNUM); | |
dc2ede84 | 2934 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
e4b8a413 JW |
2935 | /* If they are different, also mark the hard frame pointer as live */ |
2936 | SET_REGNO_REG_SET (set, HARD_FRAME_POINTER_REGNUM); | |
dc2ede84 | 2937 | #endif |
e4b8a413 | 2938 | } |
dc2ede84 | 2939 | |
d3a923ee RH |
2940 | #ifdef PIC_OFFSET_TABLE_REGNUM |
2941 | #ifndef PIC_OFFSET_TABLE_REG_CALL_CLOBBERED | |
2942 | /* Many architectures have a GP register even without flag_pic. | |
2943 | Assume the pic register is not in use, or will be handled by | |
2944 | other means, if it is not fixed. */ | |
2945 | if (fixed_regs[PIC_OFFSET_TABLE_REGNUM]) | |
2946 | SET_REGNO_REG_SET (set, PIC_OFFSET_TABLE_REGNUM); | |
2947 | #endif | |
2948 | #endif | |
2949 | ||
e881bb1b | 2950 | /* Mark all global registers, and all registers used by the epilogue |
dc2ede84 BS |
2951 | as being live at the end of the function since they may be |
2952 | referenced by our caller. */ | |
2953 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
2954 | if (global_regs[i] | |
2955 | #ifdef EPILOGUE_USES | |
2956 | || EPILOGUE_USES (i) | |
2957 | #endif | |
2958 | ) | |
2959 | SET_REGNO_REG_SET (set, i); | |
e881bb1b | 2960 | |
d3a923ee RH |
2961 | /* Mark all call-saved registers that we actaully used. */ |
2962 | if (HAVE_epilogue && reload_completed) | |
2963 | { | |
2964 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
2965 | if (! call_used_regs[i] && regs_ever_live[i]) | |
2966 | SET_REGNO_REG_SET (set, i); | |
2967 | } | |
2968 | ||
2969 | /* Mark function return value. */ | |
c13fde05 | 2970 | diddle_return_value (mark_reg, set); |
dc2ede84 BS |
2971 | } |
2972 | ||
4e872036 AS |
2973 | /* Callback function for for_each_successor_phi. DATA is a regset. |
2974 | Sets the SRC_REGNO, the regno of the phi alternative for phi node | |
2975 | INSN, in the regset. */ | |
2976 | ||
2977 | static int | |
2978 | set_phi_alternative_reg (insn, dest_regno, src_regno, data) | |
2979 | rtx insn ATTRIBUTE_UNUSED; | |
2980 | int dest_regno ATTRIBUTE_UNUSED; | |
2981 | int src_regno; | |
2982 | void *data; | |
2983 | { | |
2984 | regset live = (regset) data; | |
2985 | SET_REGNO_REG_SET (live, src_regno); | |
2986 | return 0; | |
2987 | } | |
2988 | ||
d3a923ee RH |
2989 | /* Propagate global life info around the graph of basic blocks. Begin |
2990 | considering blocks with their corresponding bit set in BLOCKS_IN. | |
2991 | BLOCKS_OUT is set for every block that was changed. */ | |
2992 | ||
2993 | static void | |
2994 | calculate_global_regs_live (blocks_in, blocks_out, flags) | |
2995 | sbitmap blocks_in, blocks_out; | |
2996 | int flags; | |
2997 | { | |
2998 | basic_block *queue, *qhead, *qtail, *qend; | |
2999 | regset tmp, new_live_at_end; | |
ee25a7a5 MM |
3000 | regset_head tmp_head; |
3001 | regset_head new_live_at_end_head; | |
d3a923ee RH |
3002 | int i; |
3003 | ||
ee25a7a5 MM |
3004 | tmp = INITIALIZE_REG_SET (tmp_head); |
3005 | new_live_at_end = INITIALIZE_REG_SET (new_live_at_end_head); | |
d3a923ee RH |
3006 | |
3007 | /* Create a worklist. Allocate an extra slot for ENTRY_BLOCK, and one | |
3008 | because the `head == tail' style test for an empty queue doesn't | |
3009 | work with a full queue. */ | |
67289ea6 | 3010 | queue = (basic_block *) xmalloc ((n_basic_blocks + 2) * sizeof (*queue)); |
d3a923ee RH |
3011 | qtail = queue; |
3012 | qhead = qend = queue + n_basic_blocks + 2; | |
3013 | ||
1344f8d5 RH |
3014 | /* Clear out the garbage that might be hanging out in bb->aux. */ |
3015 | for (i = n_basic_blocks - 1; i >= 0; --i) | |
3016 | BASIC_BLOCK (i)->aux = NULL; | |
3017 | ||
d3a923ee RH |
3018 | /* Queue the blocks set in the initial mask. Do this in reverse block |
3019 | number order so that we are more likely for the first round to do | |
3020 | useful work. We use AUX non-null to flag that the block is queued. */ | |
3021 | EXECUTE_IF_SET_IN_SBITMAP (blocks_in, 0, i, | |
3022 | { | |
3023 | basic_block bb = BASIC_BLOCK (i); | |
3024 | *--qhead = bb; | |
3025 | bb->aux = bb; | |
3026 | }); | |
3027 | ||
3028 | sbitmap_zero (blocks_out); | |
3029 | ||
3030 | while (qhead != qtail) | |
3031 | { | |
3032 | int rescan, changed; | |
3033 | basic_block bb; | |
3034 | edge e; | |
3035 | ||
3036 | bb = *qhead++; | |
3037 | if (qhead == qend) | |
3038 | qhead = queue; | |
3039 | bb->aux = NULL; | |
3040 | ||
3041 | /* Begin by propogating live_at_start from the successor blocks. */ | |
3042 | CLEAR_REG_SET (new_live_at_end); | |
3043 | for (e = bb->succ; e ; e = e->succ_next) | |
3044 | { | |
3045 | basic_block sb = e->dest; | |
3046 | IOR_REG_SET (new_live_at_end, sb->global_live_at_start); | |
3047 | } | |
3048 | ||
4e872036 AS |
3049 | /* Regs used in phi nodes are not included in |
3050 | global_live_at_start, since they are live only along a | |
3051 | particular edge. Set those regs that are live because of a | |
3052 | phi node alternative corresponding to this particular block. */ | |
3053 | for_each_successor_phi (bb->index, &set_phi_alternative_reg, | |
3054 | new_live_at_end); | |
3055 | ||
d3a923ee RH |
3056 | if (bb == ENTRY_BLOCK_PTR) |
3057 | { | |
3058 | COPY_REG_SET (bb->global_live_at_end, new_live_at_end); | |
3059 | continue; | |
3060 | } | |
3061 | ||
3062 | /* On our first pass through this block, we'll go ahead and continue. | |
3063 | Recognize first pass by local_set NULL. On subsequent passes, we | |
3064 | get to skip out early if live_at_end wouldn't have changed. */ | |
3065 | ||
3066 | if (bb->local_set == NULL) | |
3067 | { | |
3068 | bb->local_set = OBSTACK_ALLOC_REG_SET (function_obstack); | |
3069 | rescan = 1; | |
3070 | } | |
3071 | else | |
3072 | { | |
3073 | /* If any bits were removed from live_at_end, we'll have to | |
3074 | rescan the block. This wouldn't be necessary if we had | |
3075 | precalculated local_live, however with PROP_SCAN_DEAD_CODE | |
3076 | local_live is really dependant on live_at_end. */ | |
3077 | CLEAR_REG_SET (tmp); | |
3078 | rescan = bitmap_operation (tmp, bb->global_live_at_end, | |
3079 | new_live_at_end, BITMAP_AND_COMPL); | |
3080 | ||
3081 | if (! rescan) | |
3082 | { | |
3083 | /* Find the set of changed bits. Take this opportunity | |
3084 | to notice that this set is empty and early out. */ | |
3085 | CLEAR_REG_SET (tmp); | |
3086 | changed = bitmap_operation (tmp, bb->global_live_at_end, | |
3087 | new_live_at_end, BITMAP_XOR); | |
3088 | if (! changed) | |
3089 | continue; | |
3090 | ||
3091 | /* If any of the changed bits overlap with local_set, | |
3092 | we'll have to rescan the block. Detect overlap by | |
3093 | the AND with ~local_set turning off bits. */ | |
3094 | rescan = bitmap_operation (tmp, tmp, bb->local_set, | |
3095 | BITMAP_AND_COMPL); | |
3096 | } | |
3097 | } | |
3098 | ||
3099 | /* Let our caller know that BB changed enough to require its | |
3100 | death notes updated. */ | |
3101 | SET_BIT (blocks_out, bb->index); | |
3102 | ||
3103 | if (! rescan) | |
3104 | { | |
3105 | /* Add to live_at_start the set of all registers in | |
3106 | new_live_at_end that aren't in the old live_at_end. */ | |
3107 | ||
3108 | bitmap_operation (tmp, new_live_at_end, bb->global_live_at_end, | |
3109 | BITMAP_AND_COMPL); | |
3110 | COPY_REG_SET (bb->global_live_at_end, new_live_at_end); | |
3111 | ||
3112 | changed = bitmap_operation (bb->global_live_at_start, | |
3113 | bb->global_live_at_start, | |
3114 | tmp, BITMAP_IOR); | |
3115 | if (! changed) | |
3116 | continue; | |
3117 | } | |
3118 | else | |
3119 | { | |
3120 | COPY_REG_SET (bb->global_live_at_end, new_live_at_end); | |
3121 | ||
3122 | /* Rescan the block insn by insn to turn (a copy of) live_at_end | |
3123 | into live_at_start. */ | |
65f6fa24 | 3124 | propagate_block (bb, new_live_at_end, bb->local_set, flags); |
d3a923ee RH |
3125 | |
3126 | /* If live_at start didn't change, no need to go farther. */ | |
3127 | if (REG_SET_EQUAL_P (bb->global_live_at_start, new_live_at_end)) | |
3128 | continue; | |
3129 | ||
3130 | COPY_REG_SET (bb->global_live_at_start, new_live_at_end); | |
3131 | } | |
3132 | ||
3133 | /* Queue all predecessors of BB so that we may re-examine | |
3134 | their live_at_end. */ | |
3135 | for (e = bb->pred; e ; e = e->pred_next) | |
3136 | { | |
3137 | basic_block pb = e->src; | |
3138 | if (pb->aux == NULL) | |
3139 | { | |
3140 | *qtail++ = pb; | |
3141 | if (qtail == qend) | |
3142 | qtail = queue; | |
3143 | pb->aux = pb; | |
3144 | } | |
3145 | } | |
3146 | } | |
3147 | ||
3148 | FREE_REG_SET (tmp); | |
3149 | FREE_REG_SET (new_live_at_end); | |
3150 | ||
3151 | EXECUTE_IF_SET_IN_SBITMAP (blocks_out, 0, i, | |
3152 | { | |
3153 | basic_block bb = BASIC_BLOCK (i); | |
3154 | FREE_REG_SET (bb->local_set); | |
3155 | }); | |
67289ea6 MM |
3156 | |
3157 | free (queue); | |
d7429b6a RK |
3158 | } |
3159 | \f | |
3160 | /* Subroutines of life analysis. */ | |
3161 | ||
3162 | /* Allocate the permanent data structures that represent the results | |
3163 | of life analysis. Not static since used also for stupid life analysis. */ | |
3164 | ||
3165 | void | |
359da67d | 3166 | allocate_bb_life_data () |
d7429b6a RK |
3167 | { |
3168 | register int i; | |
d7429b6a | 3169 | |
e881bb1b RH |
3170 | for (i = 0; i < n_basic_blocks; i++) |
3171 | { | |
3172 | basic_block bb = BASIC_BLOCK (i); | |
3173 | ||
e881bb1b RH |
3174 | bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (function_obstack); |
3175 | bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (function_obstack); | |
3176 | } | |
3177 | ||
3178 | ENTRY_BLOCK_PTR->global_live_at_end | |
3179 | = OBSTACK_ALLOC_REG_SET (function_obstack); | |
3180 | EXIT_BLOCK_PTR->global_live_at_start | |
3181 | = OBSTACK_ALLOC_REG_SET (function_obstack); | |
d7429b6a | 3182 | |
7eb136d6 | 3183 | regs_live_at_setjmp = OBSTACK_ALLOC_REG_SET (function_obstack); |
359da67d RH |
3184 | } |
3185 | ||
3186 | void | |
3187 | allocate_reg_life_data () | |
3188 | { | |
3189 | int i; | |
3190 | ||
3191 | /* Recalculate the register space, in case it has grown. Old style | |
3192 | vector oriented regsets would set regset_{size,bytes} here also. */ | |
3193 | allocate_reg_info (max_regno, FALSE, FALSE); | |
3194 | ||
49c3bb12 RH |
3195 | /* Reset all the data we'll collect in propagate_block and its |
3196 | subroutines. */ | |
359da67d | 3197 | for (i = 0; i < max_regno; i++) |
49c3bb12 RH |
3198 | { |
3199 | REG_N_SETS (i) = 0; | |
3200 | REG_N_REFS (i) = 0; | |
3201 | REG_N_DEATHS (i) = 0; | |
3202 | REG_N_CALLS_CROSSED (i) = 0; | |
3203 | REG_LIVE_LENGTH (i) = 0; | |
3204 | REG_BASIC_BLOCK (i) = REG_BLOCK_UNKNOWN; | |
3205 | } | |
d7429b6a RK |
3206 | } |
3207 | ||
d7429b6a RK |
3208 | /* Compute the registers live at the beginning of a basic block |
3209 | from those live at the end. | |
3210 | ||
3211 | When called, OLD contains those live at the end. | |
3212 | On return, it contains those live at the beginning. | |
3213 | FIRST and LAST are the first and last insns of the basic block. | |
3214 | ||
3215 | FINAL is nonzero if we are doing the final pass which is not | |
3216 | for computing the life info (since that has already been done) | |
3217 | but for acting on it. On this pass, we delete dead stores, | |
3218 | set up the logical links and dead-variables lists of instructions, | |
3219 | and merge instructions for autoincrement and autodecrement addresses. | |
3220 | ||
3221 | SIGNIFICANT is nonzero only the first time for each basic block. | |
3222 | If it is nonzero, it points to a regset in which we store | |
3223 | a 1 for each register that is set within the block. | |
3224 | ||
3225 | BNUM is the number of the basic block. */ | |
3226 | ||
3227 | static void | |
65f6fa24 RH |
3228 | propagate_block (bb, old, significant, flags) |
3229 | basic_block bb; | |
3230 | regset old; | |
d7429b6a | 3231 | regset significant; |
d3a923ee | 3232 | int flags; |
d7429b6a RK |
3233 | { |
3234 | register rtx insn; | |
3235 | rtx prev; | |
3236 | regset live; | |
ee25a7a5 | 3237 | regset_head live_head; |
d7429b6a | 3238 | regset dead; |
ee25a7a5 | 3239 | regset_head dead_head; |
d7429b6a | 3240 | |
e881bb1b RH |
3241 | /* Find the loop depth for this block. Ignore loop level changes in the |
3242 | middle of the basic block -- for register allocation purposes, the | |
3243 | important uses will be in the blocks wholely contained within the loop | |
3244 | not in the loop pre-header or post-trailer. */ | |
65f6fa24 | 3245 | loop_depth = bb->loop_depth; |
d7429b6a | 3246 | |
ee25a7a5 MM |
3247 | dead = INITIALIZE_REG_SET (live_head); |
3248 | live = INITIALIZE_REG_SET (dead_head); | |
d7429b6a RK |
3249 | |
3250 | cc0_live = 0; | |
d7429b6a | 3251 | |
d3a923ee | 3252 | if (flags & PROP_REG_INFO) |
d7429b6a | 3253 | { |
916b1701 | 3254 | register int i; |
d7429b6a | 3255 | |
d7429b6a | 3256 | /* Process the regs live at the end of the block. |
f8dd7f98 | 3257 | Mark them as not local to any one basic block. */ |
916b1701 MM |
3258 | EXECUTE_IF_SET_IN_REG_SET (old, 0, i, |
3259 | { | |
3260 | REG_BASIC_BLOCK (i) = REG_BLOCK_GLOBAL; | |
916b1701 | 3261 | }); |
d7429b6a RK |
3262 | } |
3263 | ||
3264 | /* Scan the block an insn at a time from end to beginning. */ | |
3265 | ||
65f6fa24 | 3266 | for (insn = bb->end; ; insn = prev) |
d7429b6a RK |
3267 | { |
3268 | prev = PREV_INSN (insn); | |
3269 | ||
8329b5ec | 3270 | if (GET_CODE (insn) == NOTE) |
d7429b6a | 3271 | { |
8329b5ec DE |
3272 | /* If this is a call to `setjmp' et al, |
3273 | warn if any non-volatile datum is live. */ | |
3274 | ||
d3a923ee RH |
3275 | if ((flags & PROP_REG_INFO) |
3276 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_SETJMP) | |
916b1701 | 3277 | IOR_REG_SET (regs_live_at_setjmp, old); |
d7429b6a RK |
3278 | } |
3279 | ||
3280 | /* Update the life-status of regs for this insn. | |
3281 | First DEAD gets which regs are set in this insn | |
3282 | then LIVE gets which regs are used in this insn. | |
3283 | Then the regs live before the insn | |
3284 | are those live after, with DEAD regs turned off, | |
3285 | and then LIVE regs turned on. */ | |
3286 | ||
8329b5ec | 3287 | else if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') |
d7429b6a RK |
3288 | { |
3289 | register int i; | |
5f4f0e22 | 3290 | rtx note = find_reg_note (insn, REG_RETVAL, NULL_RTX); |
11f246f6 JH |
3291 | int insn_is_dead = 0; |
3292 | int libcall_is_dead = 0; | |
3293 | ||
d3a923ee | 3294 | if (flags & PROP_SCAN_DEAD_CODE) |
11f246f6 | 3295 | { |
3ea8083f JL |
3296 | insn_is_dead = insn_dead_p (PATTERN (insn), old, 0, |
3297 | REG_NOTES (insn)); | |
11f246f6 | 3298 | libcall_is_dead = (insn_is_dead && note != 0 |
65f6fa24 RH |
3299 | && libcall_dead_p (PATTERN (insn), old, |
3300 | note, insn)); | |
11f246f6 | 3301 | } |
d7429b6a | 3302 | |
d3a923ee RH |
3303 | /* We almost certainly don't want to delete prologue or epilogue |
3304 | instructions. Warn about probable compiler losage. */ | |
a249decd | 3305 | if (insn_is_dead |
d3a923ee | 3306 | && reload_completed |
0a1c58a2 JL |
3307 | && (((HAVE_epilogue || HAVE_prologue) |
3308 | && prologue_epilogue_contains (insn)) | |
3309 | || (HAVE_sibcall_epilogue | |
3310 | && sibcall_epilogue_contains (insn)))) | |
d3a923ee | 3311 | { |
a249decd CP |
3312 | if (flags & PROP_KILL_DEAD_CODE) |
3313 | { | |
3314 | warning ("ICE: would have deleted prologue/epilogue insn"); | |
3315 | if (!inhibit_warnings) | |
3316 | debug_rtx (insn); | |
3317 | } | |
d3a923ee RH |
3318 | libcall_is_dead = insn_is_dead = 0; |
3319 | } | |
3320 | ||
d7429b6a RK |
3321 | /* If an instruction consists of just dead store(s) on final pass, |
3322 | "delete" it by turning it into a NOTE of type NOTE_INSN_DELETED. | |
3323 | We could really delete it with delete_insn, but that | |
3324 | can cause trouble for first or last insn in a basic block. */ | |
d3a923ee | 3325 | if ((flags & PROP_KILL_DEAD_CODE) && insn_is_dead) |
d7429b6a | 3326 | { |
a6092975 GK |
3327 | rtx inote; |
3328 | /* If the insn referred to a label, note that the label is | |
3329 | now less used. */ | |
3330 | for (inote = REG_NOTES (insn); inote; inote = XEXP (inote, 1)) | |
3331 | { | |
3332 | if (REG_NOTE_KIND (inote) == REG_LABEL) | |
3333 | { | |
3334 | rtx label = XEXP (inote, 0); | |
3335 | rtx next; | |
3336 | LABEL_NUSES (label)--; | |
3337 | ||
3338 | /* If this label was attached to an ADDR_VEC, it's | |
65f6fa24 RH |
3339 | safe to delete the ADDR_VEC. In fact, it's pretty |
3340 | much mandatory to delete it, because the ADDR_VEC may | |
a6092975 GK |
3341 | be referencing labels that no longer exist. */ |
3342 | if (LABEL_NUSES (label) == 0 | |
3343 | && (next = next_nonnote_insn (label)) != NULL | |
3344 | && GET_CODE (next) == JUMP_INSN | |
3345 | && (GET_CODE (PATTERN (next)) == ADDR_VEC | |
3346 | || GET_CODE (PATTERN (next)) == ADDR_DIFF_VEC)) | |
3347 | { | |
3348 | rtx pat = PATTERN (next); | |
3349 | int diff_vec_p = GET_CODE (pat) == ADDR_DIFF_VEC; | |
3350 | int len = XVECLEN (pat, diff_vec_p); | |
3351 | int i; | |
3352 | for (i = 0; i < len; i++) | |
3353 | LABEL_NUSES (XEXP (XVECEXP (pat, diff_vec_p, i), 0))--; | |
3354 | PUT_CODE (next, NOTE); | |
3355 | NOTE_LINE_NUMBER (next) = NOTE_INSN_DELETED; | |
3356 | NOTE_SOURCE_FILE (next) = 0; | |
02ce8f4e GK |
3357 | |
3358 | if ((next = next_nonnote_insn (label)) != NULL | |
3359 | && GET_CODE (next) == BARRIER) | |
3360 | { | |
3361 | PUT_CODE (next, NOTE); | |
3362 | NOTE_LINE_NUMBER (next) = NOTE_INSN_DELETED; | |
3363 | NOTE_SOURCE_FILE (next) = 0; | |
3364 | } | |
a6092975 GK |
3365 | } |
3366 | } | |
3367 | } | |
3368 | ||
d7429b6a RK |
3369 | PUT_CODE (insn, NOTE); |
3370 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
3371 | NOTE_SOURCE_FILE (insn) = 0; | |
3372 | ||
e5df1ea3 RK |
3373 | /* CC0 is now known to be dead. Either this insn used it, |
3374 | in which case it doesn't anymore, or clobbered it, | |
3375 | so the next insn can't use it. */ | |
3376 | cc0_live = 0; | |
3377 | ||
d7429b6a RK |
3378 | /* If this insn is copying the return value from a library call, |
3379 | delete the entire library call. */ | |
3380 | if (libcall_is_dead) | |
3381 | { | |
3382 | rtx first = XEXP (note, 0); | |
3383 | rtx p = insn; | |
3384 | while (INSN_DELETED_P (first)) | |
3385 | first = NEXT_INSN (first); | |
3386 | while (p != first) | |
3387 | { | |
3388 | p = PREV_INSN (p); | |
3389 | PUT_CODE (p, NOTE); | |
3390 | NOTE_LINE_NUMBER (p) = NOTE_INSN_DELETED; | |
3391 | NOTE_SOURCE_FILE (p) = 0; | |
3392 | } | |
3393 | } | |
3394 | goto flushed; | |
3395 | } | |
3396 | ||
916b1701 MM |
3397 | CLEAR_REG_SET (dead); |
3398 | CLEAR_REG_SET (live); | |
d7429b6a RK |
3399 | |
3400 | /* See if this is an increment or decrement that can be | |
3401 | merged into a following memory address. */ | |
3402 | #ifdef AUTO_INC_DEC | |
3403 | { | |
956d6950 JL |
3404 | register rtx x = single_set (insn); |
3405 | ||
d7429b6a | 3406 | /* Does this instruction increment or decrement a register? */ |
6764d250 | 3407 | if (!reload_completed |
d3a923ee RH |
3408 | && (flags & PROP_AUTOINC) |
3409 | && x != 0 | |
d7429b6a RK |
3410 | && GET_CODE (SET_DEST (x)) == REG |
3411 | && (GET_CODE (SET_SRC (x)) == PLUS | |
3412 | || GET_CODE (SET_SRC (x)) == MINUS) | |
3413 | && XEXP (SET_SRC (x), 0) == SET_DEST (x) | |
3414 | && GET_CODE (XEXP (SET_SRC (x), 1)) == CONST_INT | |
3415 | /* Ok, look for a following memory ref we can combine with. | |
3416 | If one is found, change the memory ref to a PRE_INC | |
3417 | or PRE_DEC, cancel this insn, and return 1. | |
3418 | Return 0 if nothing has been done. */ | |
3419 | && try_pre_increment_1 (insn)) | |
3420 | goto flushed; | |
3421 | } | |
3422 | #endif /* AUTO_INC_DEC */ | |
3423 | ||
3424 | /* If this is not the final pass, and this insn is copying the | |
3425 | value of a library call and it's dead, don't scan the | |
3426 | insns that perform the library call, so that the call's | |
3427 | arguments are not marked live. */ | |
3428 | if (libcall_is_dead) | |
3429 | { | |
3430 | /* Mark the dest reg as `significant'. */ | |
d3a923ee RH |
3431 | mark_set_regs (old, dead, PATTERN (insn), NULL_RTX, |
3432 | significant, flags); | |
d7429b6a RK |
3433 | |
3434 | insn = XEXP (note, 0); | |
3435 | prev = PREV_INSN (insn); | |
3436 | } | |
3437 | else if (GET_CODE (PATTERN (insn)) == SET | |
3438 | && SET_DEST (PATTERN (insn)) == stack_pointer_rtx | |
3439 | && GET_CODE (SET_SRC (PATTERN (insn))) == PLUS | |
3440 | && XEXP (SET_SRC (PATTERN (insn)), 0) == stack_pointer_rtx | |
3441 | && GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == CONST_INT) | |
3442 | /* We have an insn to pop a constant amount off the stack. | |
3443 | (Such insns use PLUS regardless of the direction of the stack, | |
3444 | and any insn to adjust the stack by a constant is always a pop.) | |
3445 | These insns, if not dead stores, have no effect on life. */ | |
3446 | ; | |
3447 | else | |
3448 | { | |
f8dd7f98 BS |
3449 | /* Any regs live at the time of a call instruction |
3450 | must not go in a register clobbered by calls. | |
3451 | Find all regs now live and record this for them. */ | |
3452 | ||
d3a923ee RH |
3453 | if (GET_CODE (insn) == CALL_INSN |
3454 | && (flags & PROP_REG_INFO)) | |
f8dd7f98 BS |
3455 | EXECUTE_IF_SET_IN_REG_SET (old, 0, i, |
3456 | { | |
3457 | REG_N_CALLS_CROSSED (i)++; | |
3458 | }); | |
3459 | ||
d7429b6a RK |
3460 | /* LIVE gets the regs used in INSN; |
3461 | DEAD gets those set by it. Dead insns don't make anything | |
3462 | live. */ | |
3463 | ||
5f4f0e22 | 3464 | mark_set_regs (old, dead, PATTERN (insn), |
d3a923ee | 3465 | insn, significant, flags); |
d7429b6a RK |
3466 | |
3467 | /* If an insn doesn't use CC0, it becomes dead since we | |
3468 | assume that every insn clobbers it. So show it dead here; | |
3469 | mark_used_regs will set it live if it is referenced. */ | |
3470 | cc0_live = 0; | |
3471 | ||
3472 | if (! insn_is_dead) | |
d3a923ee | 3473 | mark_used_regs (old, live, PATTERN (insn), flags, insn); |
d7429b6a RK |
3474 | |
3475 | /* Sometimes we may have inserted something before INSN (such as | |
3476 | a move) when we make an auto-inc. So ensure we will scan | |
3477 | those insns. */ | |
3478 | #ifdef AUTO_INC_DEC | |
3479 | prev = PREV_INSN (insn); | |
3480 | #endif | |
3481 | ||
3482 | if (! insn_is_dead && GET_CODE (insn) == CALL_INSN) | |
3483 | { | |
3484 | register int i; | |
3485 | ||
6b67ec08 RK |
3486 | rtx note; |
3487 | ||
3488 | for (note = CALL_INSN_FUNCTION_USAGE (insn); | |
3489 | note; | |
3490 | note = XEXP (note, 1)) | |
3491 | if (GET_CODE (XEXP (note, 0)) == USE) | |
83ab3839 | 3492 | mark_used_regs (old, live, XEXP (XEXP (note, 0), 0), |
d3a923ee | 3493 | flags, insn); |
6b67ec08 | 3494 | |
d7429b6a | 3495 | /* Each call clobbers all call-clobbered regs that are not |
e4329280 | 3496 | global or fixed. Note that the function-value reg is a |
d7429b6a RK |
3497 | call-clobbered reg, and mark_set_regs has already had |
3498 | a chance to handle it. */ | |
3499 | ||
3500 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
e4329280 RK |
3501 | if (call_used_regs[i] && ! global_regs[i] |
3502 | && ! fixed_regs[i]) | |
d1abb925 RH |
3503 | { |
3504 | SET_REGNO_REG_SET (dead, i); | |
3505 | if (significant) | |
3506 | SET_REGNO_REG_SET (significant, i); | |
3507 | } | |
d7429b6a RK |
3508 | |
3509 | /* The stack ptr is used (honorarily) by a CALL insn. */ | |
916b1701 | 3510 | SET_REGNO_REG_SET (live, STACK_POINTER_REGNUM); |
d7429b6a RK |
3511 | |
3512 | /* Calls may also reference any of the global registers, | |
3513 | so they are made live. */ | |
d7429b6a RK |
3514 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) |
3515 | if (global_regs[i]) | |
9b316aa2 | 3516 | mark_used_regs (old, live, |
38a448ca | 3517 | gen_rtx_REG (reg_raw_mode[i], i), |
d3a923ee | 3518 | flags, insn); |
d7429b6a RK |
3519 | |
3520 | /* Calls also clobber memory. */ | |
ff666313 | 3521 | free_EXPR_LIST_list (&mem_set_list); |
d7429b6a RK |
3522 | } |
3523 | ||
3524 | /* Update OLD for the registers used or set. */ | |
916b1701 MM |
3525 | AND_COMPL_REG_SET (old, dead); |
3526 | IOR_REG_SET (old, live); | |
d7429b6a | 3527 | |
d7429b6a RK |
3528 | } |
3529 | ||
65f6fa24 RH |
3530 | /* On final pass, update counts of how many insns in which |
3531 | each reg is live. */ | |
d3a923ee | 3532 | if (flags & PROP_REG_INFO) |
65f6fa24 | 3533 | EXECUTE_IF_SET_IN_REG_SET (old, 0, i, { REG_LIVE_LENGTH (i)++; }); |
d7429b6a | 3534 | } |
65f6fa24 RH |
3535 | flushed: |
3536 | if (insn == bb->head) | |
d7429b6a RK |
3537 | break; |
3538 | } | |
3539 | ||
67f0e213 RK |
3540 | FREE_REG_SET (dead); |
3541 | FREE_REG_SET (live); | |
ff666313 | 3542 | free_EXPR_LIST_list (&mem_set_list); |
d7429b6a RK |
3543 | } |
3544 | \f | |
3545 | /* Return 1 if X (the body of an insn, or part of it) is just dead stores | |
3546 | (SET expressions whose destinations are registers dead after the insn). | |
3547 | NEEDED is the regset that says which regs are alive after the insn. | |
3548 | ||
e398aa80 R |
3549 | Unless CALL_OK is non-zero, an insn is needed if it contains a CALL. |
3550 | ||
3551 | If X is the entire body of an insn, NOTES contains the reg notes | |
3552 | pertaining to the insn. */ | |
d7429b6a RK |
3553 | |
3554 | static int | |
e398aa80 | 3555 | insn_dead_p (x, needed, call_ok, notes) |
d7429b6a RK |
3556 | rtx x; |
3557 | regset needed; | |
3558 | int call_ok; | |
e398aa80 | 3559 | rtx notes ATTRIBUTE_UNUSED; |
d7429b6a | 3560 | { |
e5e809f4 JL |
3561 | enum rtx_code code = GET_CODE (x); |
3562 | ||
e398aa80 R |
3563 | #ifdef AUTO_INC_DEC |
3564 | /* If flow is invoked after reload, we must take existing AUTO_INC | |
3565 | expresions into account. */ | |
3566 | if (reload_completed) | |
3567 | { | |
3568 | for ( ; notes; notes = XEXP (notes, 1)) | |
3569 | { | |
3570 | if (REG_NOTE_KIND (notes) == REG_INC) | |
3571 | { | |
3572 | int regno = REGNO (XEXP (notes, 0)); | |
3573 | ||
3574 | /* Don't delete insns to set global regs. */ | |
3575 | if ((regno < FIRST_PSEUDO_REGISTER && global_regs[regno]) | |
3576 | || REGNO_REG_SET_P (needed, regno)) | |
3577 | return 0; | |
3578 | } | |
3579 | } | |
3580 | } | |
3581 | #endif | |
3582 | ||
d7429b6a RK |
3583 | /* If setting something that's a reg or part of one, |
3584 | see if that register's altered value will be live. */ | |
3585 | ||
3586 | if (code == SET) | |
3587 | { | |
e5e809f4 JL |
3588 | rtx r = SET_DEST (x); |
3589 | ||
d7429b6a RK |
3590 | #ifdef HAVE_cc0 |
3591 | if (GET_CODE (r) == CC0) | |
3592 | return ! cc0_live; | |
3593 | #endif | |
3594 | ||
3ea8083f JL |
3595 | /* A SET that is a subroutine call cannot be dead. */ |
3596 | if (GET_CODE (SET_SRC (x)) == CALL) | |
3597 | { | |
3598 | if (! call_ok) | |
3599 | return 0; | |
3600 | } | |
3601 | ||
3602 | /* Don't eliminate loads from volatile memory or volatile asms. */ | |
3603 | else if (volatile_refs_p (SET_SRC (x))) | |
3604 | return 0; | |
3605 | ||
3606 | if (GET_CODE (r) == MEM) | |
db3a887b CB |
3607 | { |
3608 | rtx temp; | |
3ea8083f JL |
3609 | |
3610 | if (MEM_VOLATILE_P (r)) | |
3611 | return 0; | |
3612 | ||
db3a887b CB |
3613 | /* Walk the set of memory locations we are currently tracking |
3614 | and see if one is an identical match to this memory location. | |
3615 | If so, this memory write is dead (remember, we're walking | |
3616 | backwards from the end of the block to the start. */ | |
3617 | temp = mem_set_list; | |
3618 | while (temp) | |
3619 | { | |
3620 | if (rtx_equal_p (XEXP (temp, 0), r)) | |
3621 | return 1; | |
3622 | temp = XEXP (temp, 1); | |
3623 | } | |
3624 | } | |
3ea8083f JL |
3625 | else |
3626 | { | |
3627 | while (GET_CODE (r) == SUBREG | |
3628 | || GET_CODE (r) == STRICT_LOW_PART | |
3629 | || GET_CODE (r) == ZERO_EXTRACT) | |
3630 | r = XEXP (r, 0); | |
d7429b6a | 3631 | |
3ea8083f JL |
3632 | if (GET_CODE (r) == REG) |
3633 | { | |
3634 | int regno = REGNO (r); | |
d7429b6a | 3635 | |
3ea8083f JL |
3636 | /* Obvious. */ |
3637 | if (REGNO_REG_SET_P (needed, regno)) | |
3638 | return 0; | |
3639 | ||
3640 | /* If this is a hard register, verify that subsequent | |
3641 | words are not needed. */ | |
3642 | if (regno < FIRST_PSEUDO_REGISTER) | |
3643 | { | |
3644 | int n = HARD_REGNO_NREGS (regno, GET_MODE (r)); | |
3645 | ||
3646 | while (--n > 0) | |
3647 | if (REGNO_REG_SET_P (needed, regno+n)) | |
3648 | return 0; | |
3649 | } | |
3650 | ||
3651 | /* Don't delete insns to set global regs. */ | |
3652 | if (regno < FIRST_PSEUDO_REGISTER && global_regs[regno]) | |
3653 | return 0; | |
3654 | ||
3655 | /* Make sure insns to set the stack pointer aren't deleted. */ | |
3656 | if (regno == STACK_POINTER_REGNUM) | |
3657 | return 0; | |
d7429b6a | 3658 | |
3ea8083f JL |
3659 | /* Make sure insns to set the frame pointer aren't deleted. */ |
3660 | if (regno == FRAME_POINTER_REGNUM | |
e4b8a413 | 3661 | && (! reload_completed || frame_pointer_needed)) |
3ea8083f | 3662 | return 0; |
73a187c1 | 3663 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
3ea8083f | 3664 | if (regno == HARD_FRAME_POINTER_REGNUM |
e4b8a413 | 3665 | && (! reload_completed || frame_pointer_needed)) |
3ea8083f | 3666 | return 0; |
73a187c1 | 3667 | #endif |
3ea8083f | 3668 | |
d7e4fe8b RS |
3669 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
3670 | /* Make sure insns to set arg pointer are never deleted | |
3ea8083f JL |
3671 | (if the arg pointer isn't fixed, there will be a USE |
3672 | for it, so we can treat it normally). */ | |
3673 | if (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) | |
3674 | return 0; | |
d7e4fe8b | 3675 | #endif |
d7429b6a | 3676 | |
3ea8083f JL |
3677 | /* Otherwise, the set is dead. */ |
3678 | return 1; | |
d7429b6a | 3679 | } |
d7429b6a RK |
3680 | } |
3681 | } | |
e5e809f4 | 3682 | |
3ea8083f JL |
3683 | /* If performing several activities, insn is dead if each activity |
3684 | is individually dead. Also, CLOBBERs and USEs can be ignored; a | |
3685 | CLOBBER or USE that's inside a PARALLEL doesn't make the insn | |
3686 | worth keeping. */ | |
d7429b6a RK |
3687 | else if (code == PARALLEL) |
3688 | { | |
e5e809f4 JL |
3689 | int i = XVECLEN (x, 0); |
3690 | ||
d7429b6a | 3691 | for (i--; i >= 0; i--) |
e5e809f4 JL |
3692 | if (GET_CODE (XVECEXP (x, 0, i)) != CLOBBER |
3693 | && GET_CODE (XVECEXP (x, 0, i)) != USE | |
e398aa80 | 3694 | && ! insn_dead_p (XVECEXP (x, 0, i), needed, call_ok, NULL_RTX)) |
e5e809f4 JL |
3695 | return 0; |
3696 | ||
d7429b6a RK |
3697 | return 1; |
3698 | } | |
e5e809f4 JL |
3699 | |
3700 | /* A CLOBBER of a pseudo-register that is dead serves no purpose. That | |
3701 | is not necessarily true for hard registers. */ | |
3702 | else if (code == CLOBBER && GET_CODE (XEXP (x, 0)) == REG | |
3703 | && REGNO (XEXP (x, 0)) >= FIRST_PSEUDO_REGISTER | |
3704 | && ! REGNO_REG_SET_P (needed, REGNO (XEXP (x, 0)))) | |
3705 | return 1; | |
3706 | ||
3707 | /* We do not check other CLOBBER or USE here. An insn consisting of just | |
3708 | a CLOBBER or just a USE should not be deleted. */ | |
d7429b6a RK |
3709 | return 0; |
3710 | } | |
3711 | ||
3712 | /* If X is the pattern of the last insn in a libcall, and assuming X is dead, | |
3713 | return 1 if the entire library call is dead. | |
3714 | This is true if X copies a register (hard or pseudo) | |
3715 | and if the hard return reg of the call insn is dead. | |
3716 | (The caller should have tested the destination of X already for death.) | |
3717 | ||
3718 | If this insn doesn't just copy a register, then we don't | |
3719 | have an ordinary libcall. In that case, cse could not have | |
3720 | managed to substitute the source for the dest later on, | |
3721 | so we can assume the libcall is dead. | |
3722 | ||
3723 | NEEDED is the bit vector of pseudoregs live before this insn. | |
3724 | NOTE is the REG_RETVAL note of the insn. INSN is the insn itself. */ | |
3725 | ||
3726 | static int | |
3727 | libcall_dead_p (x, needed, note, insn) | |
3728 | rtx x; | |
3729 | regset needed; | |
3730 | rtx note; | |
3731 | rtx insn; | |
3732 | { | |
3733 | register RTX_CODE code = GET_CODE (x); | |
3734 | ||
3735 | if (code == SET) | |
3736 | { | |
3737 | register rtx r = SET_SRC (x); | |
3738 | if (GET_CODE (r) == REG) | |
3739 | { | |
3740 | rtx call = XEXP (note, 0); | |
e398aa80 | 3741 | rtx call_pat; |
d7429b6a RK |
3742 | register int i; |
3743 | ||
3744 | /* Find the call insn. */ | |
3745 | while (call != insn && GET_CODE (call) != CALL_INSN) | |
3746 | call = NEXT_INSN (call); | |
3747 | ||
3748 | /* If there is none, do nothing special, | |
3749 | since ordinary death handling can understand these insns. */ | |
3750 | if (call == insn) | |
3751 | return 0; | |
3752 | ||
3753 | /* See if the hard reg holding the value is dead. | |
3754 | If this is a PARALLEL, find the call within it. */ | |
e398aa80 R |
3755 | call_pat = PATTERN (call); |
3756 | if (GET_CODE (call_pat) == PARALLEL) | |
d7429b6a | 3757 | { |
e398aa80 R |
3758 | for (i = XVECLEN (call_pat, 0) - 1; i >= 0; i--) |
3759 | if (GET_CODE (XVECEXP (call_pat, 0, i)) == SET | |
3760 | && GET_CODE (SET_SRC (XVECEXP (call_pat, 0, i))) == CALL) | |
d7429b6a RK |
3761 | break; |
3762 | ||
761a5bcd JW |
3763 | /* This may be a library call that is returning a value |
3764 | via invisible pointer. Do nothing special, since | |
3765 | ordinary death handling can understand these insns. */ | |
d7429b6a | 3766 | if (i < 0) |
761a5bcd | 3767 | return 0; |
d7429b6a | 3768 | |
e398aa80 | 3769 | call_pat = XVECEXP (call_pat, 0, i); |
d7429b6a RK |
3770 | } |
3771 | ||
e398aa80 | 3772 | return insn_dead_p (call_pat, needed, 1, REG_NOTES (call)); |
d7429b6a RK |
3773 | } |
3774 | } | |
3775 | return 1; | |
3776 | } | |
3777 | ||
bd80fbde RH |
3778 | /* Return 1 if register REGNO was used before it was set, i.e. if it is |
3779 | live at function entry. Don't count global register variables, variables | |
3780 | in registers that can be used for function arg passing, or variables in | |
3781 | fixed hard registers. */ | |
d7429b6a RK |
3782 | |
3783 | int | |
3784 | regno_uninitialized (regno) | |
3785 | int regno; | |
3786 | { | |
b0b7b46a | 3787 | if (n_basic_blocks == 0 |
6a45254e | 3788 | || (regno < FIRST_PSEUDO_REGISTER |
bd80fbde RH |
3789 | && (global_regs[regno] |
3790 | || fixed_regs[regno] | |
3791 | || FUNCTION_ARG_REGNO_P (regno)))) | |
d7429b6a RK |
3792 | return 0; |
3793 | ||
e881bb1b | 3794 | return REGNO_REG_SET_P (BASIC_BLOCK (0)->global_live_at_start, regno); |
d7429b6a RK |
3795 | } |
3796 | ||
3797 | /* 1 if register REGNO was alive at a place where `setjmp' was called | |
3798 | and was set more than once or is an argument. | |
3799 | Such regs may be clobbered by `longjmp'. */ | |
3800 | ||
3801 | int | |
3802 | regno_clobbered_at_setjmp (regno) | |
3803 | int regno; | |
3804 | { | |
3805 | if (n_basic_blocks == 0) | |
3806 | return 0; | |
3807 | ||
b1f21e0a | 3808 | return ((REG_N_SETS (regno) > 1 |
e881bb1b | 3809 | || REGNO_REG_SET_P (BASIC_BLOCK (0)->global_live_at_start, regno)) |
916b1701 | 3810 | && REGNO_REG_SET_P (regs_live_at_setjmp, regno)); |
d7429b6a RK |
3811 | } |
3812 | \f | |
15e088b2 JL |
3813 | /* INSN references memory, possibly using autoincrement addressing modes. |
3814 | Find any entries on the mem_set_list that need to be invalidated due | |
3815 | to an address change. */ | |
3816 | static void | |
3817 | invalidate_mems_from_autoinc (insn) | |
3818 | rtx insn; | |
3819 | { | |
3820 | rtx note = REG_NOTES (insn); | |
3821 | for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) | |
3822 | { | |
3823 | if (REG_NOTE_KIND (note) == REG_INC) | |
3824 | { | |
3825 | rtx temp = mem_set_list; | |
3826 | rtx prev = NULL_RTX; | |
ff666313 | 3827 | rtx next; |
15e088b2 JL |
3828 | |
3829 | while (temp) | |
3830 | { | |
ff666313 | 3831 | next = XEXP (temp, 1); |
15e088b2 JL |
3832 | if (reg_overlap_mentioned_p (XEXP (note, 0), XEXP (temp, 0))) |
3833 | { | |
3834 | /* Splice temp out of list. */ | |
3835 | if (prev) | |
ff666313 | 3836 | XEXP (prev, 1) = next; |
15e088b2 | 3837 | else |
ff666313 RH |
3838 | mem_set_list = next; |
3839 | free_EXPR_LIST_node (temp); | |
15e088b2 JL |
3840 | } |
3841 | else | |
3842 | prev = temp; | |
ff666313 | 3843 | temp = next; |
15e088b2 JL |
3844 | } |
3845 | } | |
3846 | } | |
3847 | } | |
3848 | ||
d3a923ee RH |
3849 | /* Process the registers that are set within X. Their bits are set to |
3850 | 1 in the regset DEAD, because they are dead prior to this insn. | |
d7429b6a | 3851 | |
d3a923ee RH |
3852 | If INSN is nonzero, it is the insn being processed. |
3853 | ||
3854 | FLAGS is the set of operations to perform. */ | |
d7429b6a | 3855 | |
d7429b6a | 3856 | static void |
d3a923ee | 3857 | mark_set_regs (needed, dead, x, insn, significant, flags) |
d7429b6a RK |
3858 | regset needed; |
3859 | regset dead; | |
3860 | rtx x; | |
3861 | rtx insn; | |
3862 | regset significant; | |
d3a923ee | 3863 | int flags; |
d7429b6a RK |
3864 | { |
3865 | register RTX_CODE code = GET_CODE (x); | |
3866 | ||
3867 | if (code == SET || code == CLOBBER) | |
d3a923ee | 3868 | mark_set_1 (needed, dead, x, insn, significant, flags); |
d7429b6a RK |
3869 | else if (code == PARALLEL) |
3870 | { | |
3871 | register int i; | |
3872 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
3873 | { | |
3874 | code = GET_CODE (XVECEXP (x, 0, i)); | |
3875 | if (code == SET || code == CLOBBER) | |
d3a923ee RH |
3876 | mark_set_1 (needed, dead, XVECEXP (x, 0, i), insn, |
3877 | significant, flags); | |
d7429b6a RK |
3878 | } |
3879 | } | |
3880 | } | |
3881 | ||
3882 | /* Process a single SET rtx, X. */ | |
3883 | ||
3884 | static void | |
d3a923ee | 3885 | mark_set_1 (needed, dead, x, insn, significant, flags) |
d7429b6a RK |
3886 | regset needed; |
3887 | regset dead; | |
3888 | rtx x; | |
3889 | rtx insn; | |
3890 | regset significant; | |
d3a923ee | 3891 | int flags; |
d7429b6a | 3892 | { |
f428f252 | 3893 | register int regno = -1; |
d7429b6a RK |
3894 | register rtx reg = SET_DEST (x); |
3895 | ||
86465af7 DM |
3896 | /* Some targets place small structures in registers for |
3897 | return values of functions. We have to detect this | |
3898 | case specially here to get correct flow information. */ | |
3899 | if (GET_CODE (reg) == PARALLEL | |
3900 | && GET_MODE (reg) == BLKmode) | |
3901 | { | |
3902 | register int i; | |
3903 | ||
3904 | for (i = XVECLEN (reg, 0) - 1; i >= 0; i--) | |
d3a923ee RH |
3905 | mark_set_1 (needed, dead, XVECEXP (reg, 0, i), insn, |
3906 | significant, flags); | |
86465af7 DM |
3907 | return; |
3908 | } | |
3909 | ||
d7429b6a RK |
3910 | /* Modifying just one hardware register of a multi-reg value |
3911 | or just a byte field of a register | |
3912 | does not mean the value from before this insn is now dead. | |
3913 | But it does mean liveness of that register at the end of the block | |
3914 | is significant. | |
3915 | ||
3916 | Within mark_set_1, however, we treat it as if the register is | |
3917 | indeed modified. mark_used_regs will, however, also treat this | |
3918 | register as being used. Thus, we treat these insns as setting a | |
3919 | new value for the register as a function of its old value. This | |
3920 | cases LOG_LINKS to be made appropriately and this will help combine. */ | |
3921 | ||
3922 | while (GET_CODE (reg) == SUBREG || GET_CODE (reg) == ZERO_EXTRACT | |
3923 | || GET_CODE (reg) == SIGN_EXTRACT | |
3924 | || GET_CODE (reg) == STRICT_LOW_PART) | |
3925 | reg = XEXP (reg, 0); | |
3926 | ||
db3a887b CB |
3927 | /* If this set is a MEM, then it kills any aliased writes. |
3928 | If this set is a REG, then it kills any MEMs which use the reg. */ | |
d3a923ee | 3929 | if (flags & PROP_SCAN_DEAD_CODE) |
db3a887b | 3930 | { |
d3a923ee RH |
3931 | if (GET_CODE (reg) == MEM |
3932 | || GET_CODE (reg) == REG) | |
db3a887b | 3933 | { |
d3a923ee RH |
3934 | rtx temp = mem_set_list; |
3935 | rtx prev = NULL_RTX; | |
ff666313 | 3936 | rtx next; |
d3a923ee RH |
3937 | |
3938 | while (temp) | |
db3a887b | 3939 | { |
ff666313 | 3940 | next = XEXP (temp, 1); |
d3a923ee RH |
3941 | if ((GET_CODE (reg) == MEM |
3942 | && output_dependence (XEXP (temp, 0), reg)) | |
3943 | || (GET_CODE (reg) == REG | |
3944 | && reg_overlap_mentioned_p (reg, XEXP (temp, 0)))) | |
3945 | { | |
3946 | /* Splice this entry out of the list. */ | |
3947 | if (prev) | |
ff666313 | 3948 | XEXP (prev, 1) = next; |
d3a923ee | 3949 | else |
ff666313 RH |
3950 | mem_set_list = next; |
3951 | free_EXPR_LIST_node (temp); | |
d3a923ee | 3952 | } |
db3a887b | 3953 | else |
d3a923ee | 3954 | prev = temp; |
ff666313 | 3955 | temp = next; |
db3a887b | 3956 | } |
db3a887b | 3957 | } |
15e088b2 | 3958 | |
d3a923ee RH |
3959 | /* If the memory reference had embedded side effects (autoincrement |
3960 | address modes. Then we may need to kill some entries on the | |
3961 | memory set list. */ | |
3962 | if (insn && GET_CODE (reg) == MEM) | |
3963 | invalidate_mems_from_autoinc (insn); | |
3964 | ||
3965 | if (GET_CODE (reg) == MEM && ! side_effects_p (reg) | |
3966 | /* We do not know the size of a BLKmode store, so we do not track | |
3967 | them for redundant store elimination. */ | |
3968 | && GET_MODE (reg) != BLKmode | |
3969 | /* There are no REG_INC notes for SP, so we can't assume we'll see | |
3970 | everything that invalidates it. To be safe, don't eliminate any | |
3971 | stores though SP; none of them should be redundant anyway. */ | |
3972 | && ! reg_mentioned_p (stack_pointer_rtx, reg)) | |
3973 | mem_set_list = alloc_EXPR_LIST (0, reg, mem_set_list); | |
3974 | } | |
d7429b6a RK |
3975 | |
3976 | if (GET_CODE (reg) == REG | |
d3a923ee RH |
3977 | && (regno = REGNO (reg), |
3978 | ! (regno == FRAME_POINTER_REGNUM | |
3979 | && (! reload_completed || frame_pointer_needed))) | |
73a187c1 | 3980 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
e4b8a413 JW |
3981 | && ! (regno == HARD_FRAME_POINTER_REGNUM |
3982 | && (! reload_completed || frame_pointer_needed)) | |
73a187c1 | 3983 | #endif |
d7e4fe8b RS |
3984 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
3985 | && ! (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) | |
3986 | #endif | |
d7429b6a | 3987 | && ! (regno < FIRST_PSEUDO_REGISTER && global_regs[regno])) |
d3a923ee | 3988 | /* && regno != STACK_POINTER_REGNUM) -- let's try without this. */ |
d7429b6a | 3989 | { |
916b1701 MM |
3990 | int some_needed = REGNO_REG_SET_P (needed, regno); |
3991 | int some_not_needed = ! some_needed; | |
d7429b6a RK |
3992 | |
3993 | /* Mark it as a significant register for this basic block. */ | |
3994 | if (significant) | |
916b1701 | 3995 | SET_REGNO_REG_SET (significant, regno); |
d7429b6a | 3996 | |
38e01259 | 3997 | /* Mark it as dead before this insn. */ |
916b1701 | 3998 | SET_REGNO_REG_SET (dead, regno); |
d7429b6a RK |
3999 | |
4000 | /* A hard reg in a wide mode may really be multiple registers. | |
4001 | If so, mark all of them just like the first. */ | |
4002 | if (regno < FIRST_PSEUDO_REGISTER) | |
4003 | { | |
4004 | int n; | |
4005 | ||
4006 | /* Nothing below is needed for the stack pointer; get out asap. | |
4007 | Eg, log links aren't needed, since combine won't use them. */ | |
4008 | if (regno == STACK_POINTER_REGNUM) | |
4009 | return; | |
4010 | ||
4011 | n = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
4012 | while (--n > 0) | |
4013 | { | |
916b1701 MM |
4014 | int regno_n = regno + n; |
4015 | int needed_regno = REGNO_REG_SET_P (needed, regno_n); | |
d7429b6a | 4016 | if (significant) |
916b1701 | 4017 | SET_REGNO_REG_SET (significant, regno_n); |
cb9e8ad1 | 4018 | |
916b1701 MM |
4019 | SET_REGNO_REG_SET (dead, regno_n); |
4020 | some_needed |= needed_regno; | |
4021 | some_not_needed |= ! needed_regno; | |
d7429b6a RK |
4022 | } |
4023 | } | |
d3a923ee | 4024 | |
d7429b6a | 4025 | /* Additional data to record if this is the final pass. */ |
d3a923ee RH |
4026 | if (flags & (PROP_LOG_LINKS | PROP_REG_INFO |
4027 | | PROP_DEATH_NOTES | PROP_AUTOINC)) | |
d7429b6a | 4028 | { |
d3a923ee | 4029 | register rtx y; |
d7429b6a RK |
4030 | register int blocknum = BLOCK_NUM (insn); |
4031 | ||
d3a923ee RH |
4032 | y = NULL_RTX; |
4033 | if (flags & (PROP_LOG_LINKS | PROP_AUTOINC)) | |
4034 | y = reg_next_use[regno]; | |
4035 | ||
d7429b6a RK |
4036 | /* If this is a hard reg, record this function uses the reg. */ |
4037 | ||
4038 | if (regno < FIRST_PSEUDO_REGISTER) | |
4039 | { | |
4040 | register int i; | |
4041 | int endregno = regno + HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
4042 | ||
d3a923ee RH |
4043 | if (flags & (PROP_LOG_LINKS | PROP_AUTOINC)) |
4044 | for (i = regno; i < endregno; i++) | |
4045 | { | |
4046 | /* The next use is no longer "next", since a store | |
4047 | intervenes. */ | |
4048 | reg_next_use[i] = 0; | |
4049 | } | |
93514916 | 4050 | |
d3a923ee RH |
4051 | if (flags & PROP_REG_INFO) |
4052 | for (i = regno; i < endregno; i++) | |
4053 | { | |
4054 | regs_ever_live[i] = 1; | |
4055 | REG_N_SETS (i)++; | |
4056 | } | |
d7429b6a RK |
4057 | } |
4058 | else | |
4059 | { | |
93514916 JW |
4060 | /* The next use is no longer "next", since a store |
4061 | intervenes. */ | |
d3a923ee RH |
4062 | if (flags & (PROP_LOG_LINKS | PROP_AUTOINC)) |
4063 | reg_next_use[regno] = 0; | |
93514916 | 4064 | |
d7429b6a RK |
4065 | /* Keep track of which basic blocks each reg appears in. */ |
4066 | ||
d3a923ee RH |
4067 | if (flags & PROP_REG_INFO) |
4068 | { | |
4069 | if (REG_BASIC_BLOCK (regno) == REG_BLOCK_UNKNOWN) | |
4070 | REG_BASIC_BLOCK (regno) = blocknum; | |
4071 | else if (REG_BASIC_BLOCK (regno) != blocknum) | |
4072 | REG_BASIC_BLOCK (regno) = REG_BLOCK_GLOBAL; | |
4073 | ||
4074 | /* Count (weighted) references, stores, etc. This counts a | |
4075 | register twice if it is modified, but that is correct. */ | |
4076 | REG_N_SETS (regno)++; | |
9b15c17f | 4077 | REG_N_REFS (regno) += loop_depth + 1; |
d7429b6a | 4078 | |
d3a923ee RH |
4079 | /* The insns where a reg is live are normally counted |
4080 | elsewhere, but we want the count to include the insn | |
4081 | where the reg is set, and the normal counting mechanism | |
4082 | would not count it. */ | |
4083 | REG_LIVE_LENGTH (regno)++; | |
4084 | } | |
d7429b6a RK |
4085 | } |
4086 | ||
cb9e8ad1 | 4087 | if (! some_not_needed) |
d7429b6a | 4088 | { |
d3a923ee RH |
4089 | if (flags & PROP_LOG_LINKS) |
4090 | { | |
4091 | /* Make a logical link from the next following insn | |
4092 | that uses this register, back to this insn. | |
4093 | The following insns have already been processed. | |
4094 | ||
4095 | We don't build a LOG_LINK for hard registers containing | |
4096 | in ASM_OPERANDs. If these registers get replaced, | |
4097 | we might wind up changing the semantics of the insn, | |
4098 | even if reload can make what appear to be valid | |
4099 | assignments later. */ | |
4100 | if (y && (BLOCK_NUM (y) == blocknum) | |
4101 | && (regno >= FIRST_PSEUDO_REGISTER | |
4102 | || asm_noperands (PATTERN (y)) < 0)) | |
4103 | LOG_LINKS (y) = alloc_INSN_LIST (insn, LOG_LINKS (y)); | |
4104 | } | |
d7429b6a RK |
4105 | } |
4106 | else if (! some_needed) | |
4107 | { | |
d3a923ee RH |
4108 | if (flags & PROP_REG_INFO) |
4109 | REG_N_DEATHS (REGNO (reg))++; | |
4110 | ||
4111 | if (flags & PROP_DEATH_NOTES) | |
4112 | { | |
4113 | /* Note that dead stores have already been deleted | |
4114 | when possible. If we get here, we have found a | |
4115 | dead store that cannot be eliminated (because the | |
4116 | same insn does something useful). Indicate this | |
4117 | by marking the reg being set as dying here. */ | |
4118 | REG_NOTES (insn) | |
4119 | = alloc_EXPR_LIST (REG_UNUSED, reg, REG_NOTES (insn)); | |
4120 | } | |
d7429b6a RK |
4121 | } |
4122 | else | |
4123 | { | |
d3a923ee RH |
4124 | if (flags & PROP_DEATH_NOTES) |
4125 | { | |
4126 | /* This is a case where we have a multi-word hard register | |
4127 | and some, but not all, of the words of the register are | |
4128 | needed in subsequent insns. Write REG_UNUSED notes | |
4129 | for those parts that were not needed. This case should | |
4130 | be rare. */ | |
4131 | ||
4132 | int i; | |
4133 | ||
4134 | for (i = HARD_REGNO_NREGS (regno, GET_MODE (reg)) - 1; | |
4135 | i >= 0; i--) | |
4136 | if (!REGNO_REG_SET_P (needed, regno + i)) | |
4137 | REG_NOTES (insn) | |
4138 | = (alloc_EXPR_LIST | |
4139 | (REG_UNUSED, | |
4140 | gen_rtx_REG (reg_raw_mode[regno + i], regno + i), | |
4141 | REG_NOTES (insn))); | |
4142 | } | |
d7429b6a RK |
4143 | } |
4144 | } | |
4145 | } | |
8244fc4f | 4146 | else if (GET_CODE (reg) == REG) |
d3a923ee RH |
4147 | { |
4148 | if (flags & (PROP_LOG_LINKS | PROP_AUTOINC)) | |
4149 | reg_next_use[regno] = 0; | |
4150 | } | |
d7429b6a RK |
4151 | |
4152 | /* If this is the last pass and this is a SCRATCH, show it will be dying | |
4153 | here and count it. */ | |
d3a923ee | 4154 | else if (GET_CODE (reg) == SCRATCH) |
d7429b6a | 4155 | { |
d3a923ee RH |
4156 | if (flags & PROP_DEATH_NOTES) |
4157 | REG_NOTES (insn) | |
4158 | = alloc_EXPR_LIST (REG_UNUSED, reg, REG_NOTES (insn)); | |
d7429b6a RK |
4159 | } |
4160 | } | |
4161 | \f | |
4162 | #ifdef AUTO_INC_DEC | |
4163 | ||
4164 | /* X is a MEM found in INSN. See if we can convert it into an auto-increment | |
4165 | reference. */ | |
4166 | ||
4167 | static void | |
4168 | find_auto_inc (needed, x, insn) | |
4169 | regset needed; | |
4170 | rtx x; | |
4171 | rtx insn; | |
4172 | { | |
4173 | rtx addr = XEXP (x, 0); | |
e658434c | 4174 | HOST_WIDE_INT offset = 0; |
05ed5d57 | 4175 | rtx set; |
d7429b6a RK |
4176 | |
4177 | /* Here we detect use of an index register which might be good for | |
4178 | postincrement, postdecrement, preincrement, or predecrement. */ | |
4179 | ||
4180 | if (GET_CODE (addr) == PLUS && GET_CODE (XEXP (addr, 1)) == CONST_INT) | |
4181 | offset = INTVAL (XEXP (addr, 1)), addr = XEXP (addr, 0); | |
4182 | ||
4183 | if (GET_CODE (addr) == REG) | |
4184 | { | |
4185 | register rtx y; | |
4186 | register int size = GET_MODE_SIZE (GET_MODE (x)); | |
4187 | rtx use; | |
4188 | rtx incr; | |
4189 | int regno = REGNO (addr); | |
4190 | ||
4191 | /* Is the next use an increment that might make auto-increment? */ | |
05ed5d57 RK |
4192 | if ((incr = reg_next_use[regno]) != 0 |
4193 | && (set = single_set (incr)) != 0 | |
4194 | && GET_CODE (set) == SET | |
d7429b6a RK |
4195 | && BLOCK_NUM (incr) == BLOCK_NUM (insn) |
4196 | /* Can't add side effects to jumps; if reg is spilled and | |
4197 | reloaded, there's no way to store back the altered value. */ | |
4198 | && GET_CODE (insn) != JUMP_INSN | |
05ed5d57 | 4199 | && (y = SET_SRC (set), GET_CODE (y) == PLUS) |
d7429b6a RK |
4200 | && XEXP (y, 0) == addr |
4201 | && GET_CODE (XEXP (y, 1)) == CONST_INT | |
940da324 JL |
4202 | && ((HAVE_POST_INCREMENT |
4203 | && (INTVAL (XEXP (y, 1)) == size && offset == 0)) | |
4204 | || (HAVE_POST_DECREMENT | |
4205 | && (INTVAL (XEXP (y, 1)) == - size && offset == 0)) | |
4206 | || (HAVE_PRE_INCREMENT | |
4207 | && (INTVAL (XEXP (y, 1)) == size && offset == size)) | |
4208 | || (HAVE_PRE_DECREMENT | |
4209 | && (INTVAL (XEXP (y, 1)) == - size && offset == - size))) | |
d7429b6a RK |
4210 | /* Make sure this reg appears only once in this insn. */ |
4211 | && (use = find_use_as_address (PATTERN (insn), addr, offset), | |
4212 | use != 0 && use != (rtx) 1)) | |
4213 | { | |
05ed5d57 | 4214 | rtx q = SET_DEST (set); |
7280c2a4 RK |
4215 | enum rtx_code inc_code = (INTVAL (XEXP (y, 1)) == size |
4216 | ? (offset ? PRE_INC : POST_INC) | |
4217 | : (offset ? PRE_DEC : POST_DEC)); | |
d7429b6a RK |
4218 | |
4219 | if (dead_or_set_p (incr, addr)) | |
7280c2a4 RK |
4220 | { |
4221 | /* This is the simple case. Try to make the auto-inc. If | |
4222 | we can't, we are done. Otherwise, we will do any | |
4223 | needed updates below. */ | |
4224 | if (! validate_change (insn, &XEXP (x, 0), | |
38a448ca | 4225 | gen_rtx_fmt_e (inc_code, Pmode, addr), |
7280c2a4 RK |
4226 | 0)) |
4227 | return; | |
4228 | } | |
5175ad37 DE |
4229 | else if (GET_CODE (q) == REG |
4230 | /* PREV_INSN used here to check the semi-open interval | |
4231 | [insn,incr). */ | |
b24884cd JL |
4232 | && ! reg_used_between_p (q, PREV_INSN (insn), incr) |
4233 | /* We must also check for sets of q as q may be | |
4234 | a call clobbered hard register and there may | |
4235 | be a call between PREV_INSN (insn) and incr. */ | |
4236 | && ! reg_set_between_p (q, PREV_INSN (insn), incr)) | |
d7429b6a | 4237 | { |
5175ad37 | 4238 | /* We have *p followed sometime later by q = p+size. |
d7429b6a | 4239 | Both p and q must be live afterward, |
9ec36da5 | 4240 | and q is not used between INSN and its assignment. |
d7429b6a RK |
4241 | Change it to q = p, ...*q..., q = q+size. |
4242 | Then fall into the usual case. */ | |
4243 | rtx insns, temp; | |
e881bb1b | 4244 | basic_block bb; |
d7429b6a RK |
4245 | |
4246 | start_sequence (); | |
4247 | emit_move_insn (q, addr); | |
4248 | insns = get_insns (); | |
4249 | end_sequence (); | |
4250 | ||
e881bb1b | 4251 | bb = BLOCK_FOR_INSN (insn); |
d7429b6a | 4252 | for (temp = insns; temp; temp = NEXT_INSN (temp)) |
e881bb1b | 4253 | set_block_for_insn (temp, bb); |
d7429b6a | 4254 | |
7280c2a4 RK |
4255 | /* If we can't make the auto-inc, or can't make the |
4256 | replacement into Y, exit. There's no point in making | |
4257 | the change below if we can't do the auto-inc and doing | |
4258 | so is not correct in the pre-inc case. */ | |
4259 | ||
4260 | validate_change (insn, &XEXP (x, 0), | |
38a448ca | 4261 | gen_rtx_fmt_e (inc_code, Pmode, q), |
7280c2a4 RK |
4262 | 1); |
4263 | validate_change (incr, &XEXP (y, 0), q, 1); | |
4264 | if (! apply_change_group ()) | |
4265 | return; | |
4266 | ||
4267 | /* We now know we'll be doing this change, so emit the | |
4268 | new insn(s) and do the updates. */ | |
d7429b6a | 4269 | emit_insns_before (insns, insn); |
e8b641a1 | 4270 | |
e881bb1b RH |
4271 | if (BLOCK_FOR_INSN (insn)->head == insn) |
4272 | BLOCK_FOR_INSN (insn)->head = insns; | |
e8b641a1 | 4273 | |
d7429b6a RK |
4274 | /* INCR will become a NOTE and INSN won't contain a |
4275 | use of ADDR. If a use of ADDR was just placed in | |
4276 | the insn before INSN, make that the next use. | |
4277 | Otherwise, invalidate it. */ | |
4278 | if (GET_CODE (PREV_INSN (insn)) == INSN | |
4279 | && GET_CODE (PATTERN (PREV_INSN (insn))) == SET | |
4280 | && SET_SRC (PATTERN (PREV_INSN (insn))) == addr) | |
4281 | reg_next_use[regno] = PREV_INSN (insn); | |
4282 | else | |
4283 | reg_next_use[regno] = 0; | |
4284 | ||
4285 | addr = q; | |
4286 | regno = REGNO (q); | |
d7429b6a RK |
4287 | |
4288 | /* REGNO is now used in INCR which is below INSN, but | |
4289 | it previously wasn't live here. If we don't mark | |
4290 | it as needed, we'll put a REG_DEAD note for it | |
4291 | on this insn, which is incorrect. */ | |
916b1701 | 4292 | SET_REGNO_REG_SET (needed, regno); |
d7429b6a RK |
4293 | |
4294 | /* If there are any calls between INSN and INCR, show | |
4295 | that REGNO now crosses them. */ | |
4296 | for (temp = insn; temp != incr; temp = NEXT_INSN (temp)) | |
4297 | if (GET_CODE (temp) == CALL_INSN) | |
b1f21e0a | 4298 | REG_N_CALLS_CROSSED (regno)++; |
d7429b6a | 4299 | } |
02df8aba RK |
4300 | else |
4301 | return; | |
d7429b6a | 4302 | |
7280c2a4 RK |
4303 | /* If we haven't returned, it means we were able to make the |
4304 | auto-inc, so update the status. First, record that this insn | |
4305 | has an implicit side effect. */ | |
4306 | ||
4307 | REG_NOTES (insn) | |
d3a923ee | 4308 | = alloc_EXPR_LIST (REG_INC, addr, REG_NOTES (insn)); |
7280c2a4 RK |
4309 | |
4310 | /* Modify the old increment-insn to simply copy | |
4311 | the already-incremented value of our register. */ | |
4312 | if (! validate_change (incr, &SET_SRC (set), addr, 0)) | |
4313 | abort (); | |
4314 | ||
4315 | /* If that makes it a no-op (copying the register into itself) delete | |
4316 | it so it won't appear to be a "use" and a "set" of this | |
4317 | register. */ | |
4318 | if (SET_DEST (set) == addr) | |
d7429b6a | 4319 | { |
7280c2a4 RK |
4320 | PUT_CODE (incr, NOTE); |
4321 | NOTE_LINE_NUMBER (incr) = NOTE_INSN_DELETED; | |
4322 | NOTE_SOURCE_FILE (incr) = 0; | |
4323 | } | |
d7429b6a | 4324 | |
7280c2a4 RK |
4325 | if (regno >= FIRST_PSEUDO_REGISTER) |
4326 | { | |
4327 | /* Count an extra reference to the reg. When a reg is | |
4328 | incremented, spilling it is worse, so we want to make | |
4329 | that less likely. */ | |
9b15c17f | 4330 | REG_N_REFS (regno) += loop_depth + 1; |
7280c2a4 RK |
4331 | |
4332 | /* Count the increment as a setting of the register, | |
4333 | even though it isn't a SET in rtl. */ | |
b1f21e0a | 4334 | REG_N_SETS (regno)++; |
d7429b6a RK |
4335 | } |
4336 | } | |
4337 | } | |
4338 | } | |
4339 | #endif /* AUTO_INC_DEC */ | |
4340 | \f | |
4341 | /* Scan expression X and store a 1-bit in LIVE for each reg it uses. | |
4342 | This is done assuming the registers needed from X | |
4343 | are those that have 1-bits in NEEDED. | |
4344 | ||
d3a923ee | 4345 | FLAGS is the set of enabled operations. |
d7429b6a RK |
4346 | |
4347 | INSN is the containing instruction. If INSN is dead, this function is not | |
4348 | called. */ | |
4349 | ||
4350 | static void | |
d3a923ee | 4351 | mark_used_regs (needed, live, x, flags, insn) |
d7429b6a RK |
4352 | regset needed; |
4353 | regset live; | |
4354 | rtx x; | |
d3a923ee | 4355 | int flags; |
e658434c | 4356 | rtx insn; |
d7429b6a RK |
4357 | { |
4358 | register RTX_CODE code; | |
4359 | register int regno; | |
4360 | int i; | |
4361 | ||
4362 | retry: | |
4363 | code = GET_CODE (x); | |
4364 | switch (code) | |
4365 | { | |
4366 | case LABEL_REF: | |
4367 | case SYMBOL_REF: | |
4368 | case CONST_INT: | |
4369 | case CONST: | |
4370 | case CONST_DOUBLE: | |
4371 | case PC: | |
d7429b6a RK |
4372 | case ADDR_VEC: |
4373 | case ADDR_DIFF_VEC: | |
d7429b6a RK |
4374 | return; |
4375 | ||
4376 | #ifdef HAVE_cc0 | |
4377 | case CC0: | |
4378 | cc0_live = 1; | |
4379 | return; | |
4380 | #endif | |
4381 | ||
2f1553a4 RK |
4382 | case CLOBBER: |
4383 | /* If we are clobbering a MEM, mark any registers inside the address | |
4384 | as being used. */ | |
4385 | if (GET_CODE (XEXP (x, 0)) == MEM) | |
d3a923ee | 4386 | mark_used_regs (needed, live, XEXP (XEXP (x, 0), 0), flags, insn); |
2f1553a4 RK |
4387 | return; |
4388 | ||
d7429b6a | 4389 | case MEM: |
d3a923ee RH |
4390 | /* Don't bother watching stores to mems if this is not the |
4391 | final pass. We'll not be deleting dead stores this round. */ | |
4392 | if (flags & PROP_SCAN_DEAD_CODE) | |
db3a887b | 4393 | { |
d3a923ee RH |
4394 | /* Invalidate the data for the last MEM stored, but only if MEM is |
4395 | something that can be stored into. */ | |
4396 | if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF | |
4397 | && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0))) | |
4398 | ; /* needn't clear the memory set list */ | |
4399 | else | |
db3a887b | 4400 | { |
d3a923ee RH |
4401 | rtx temp = mem_set_list; |
4402 | rtx prev = NULL_RTX; | |
ff666313 | 4403 | rtx next; |
d3a923ee RH |
4404 | |
4405 | while (temp) | |
db3a887b | 4406 | { |
ff666313 | 4407 | next = XEXP (temp, 1); |
d3a923ee RH |
4408 | if (anti_dependence (XEXP (temp, 0), x)) |
4409 | { | |
4410 | /* Splice temp out of the list. */ | |
4411 | if (prev) | |
ff666313 | 4412 | XEXP (prev, 1) = next; |
d3a923ee | 4413 | else |
ff666313 RH |
4414 | mem_set_list = next; |
4415 | free_EXPR_LIST_node (temp); | |
d3a923ee | 4416 | } |
db3a887b | 4417 | else |
d3a923ee | 4418 | prev = temp; |
ff666313 | 4419 | temp = next; |
db3a887b | 4420 | } |
db3a887b | 4421 | } |
d7429b6a | 4422 | |
d3a923ee RH |
4423 | /* If the memory reference had embedded side effects (autoincrement |
4424 | address modes. Then we may need to kill some entries on the | |
4425 | memory set list. */ | |
4426 | if (insn) | |
4427 | invalidate_mems_from_autoinc (insn); | |
4428 | } | |
15e088b2 | 4429 | |
d7429b6a | 4430 | #ifdef AUTO_INC_DEC |
d3a923ee RH |
4431 | if (flags & PROP_AUTOINC) |
4432 | find_auto_inc (needed, x, insn); | |
d7429b6a RK |
4433 | #endif |
4434 | break; | |
4435 | ||
80f8f04a RK |
4436 | case SUBREG: |
4437 | if (GET_CODE (SUBREG_REG (x)) == REG | |
4438 | && REGNO (SUBREG_REG (x)) >= FIRST_PSEUDO_REGISTER | |
4439 | && (GET_MODE_SIZE (GET_MODE (x)) | |
88285acf | 4440 | != GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))) |
b1f21e0a | 4441 | REG_CHANGES_SIZE (REGNO (SUBREG_REG (x))) = 1; |
80f8f04a RK |
4442 | |
4443 | /* While we're here, optimize this case. */ | |
4444 | x = SUBREG_REG (x); | |
4445 | ||
e100a3bb | 4446 | /* In case the SUBREG is not of a register, don't optimize */ |
ce79abf3 | 4447 | if (GET_CODE (x) != REG) |
e100a3bb | 4448 | { |
d3a923ee | 4449 | mark_used_regs (needed, live, x, flags, insn); |
e100a3bb MM |
4450 | return; |
4451 | } | |
ce79abf3 | 4452 | |
0f41302f | 4453 | /* ... fall through ... */ |
80f8f04a | 4454 | |
d7429b6a RK |
4455 | case REG: |
4456 | /* See a register other than being set | |
4457 | => mark it as needed. */ | |
4458 | ||
4459 | regno = REGNO (x); | |
4460 | { | |
67f0e213 RK |
4461 | int some_needed = REGNO_REG_SET_P (needed, regno); |
4462 | int some_not_needed = ! some_needed; | |
d7429b6a | 4463 | |
916b1701 | 4464 | SET_REGNO_REG_SET (live, regno); |
cb9e8ad1 | 4465 | |
d7429b6a RK |
4466 | /* A hard reg in a wide mode may really be multiple registers. |
4467 | If so, mark all of them just like the first. */ | |
4468 | if (regno < FIRST_PSEUDO_REGISTER) | |
4469 | { | |
4470 | int n; | |
4471 | ||
d7e4fe8b | 4472 | /* For stack ptr or fixed arg pointer, |
d7429b6a RK |
4473 | nothing below can be necessary, so waste no more time. */ |
4474 | if (regno == STACK_POINTER_REGNUM | |
73a187c1 | 4475 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
e4b8a413 JW |
4476 | || (regno == HARD_FRAME_POINTER_REGNUM |
4477 | && (! reload_completed || frame_pointer_needed)) | |
73a187c1 | 4478 | #endif |
d7e4fe8b RS |
4479 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
4480 | || (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) | |
4481 | #endif | |
e4b8a413 JW |
4482 | || (regno == FRAME_POINTER_REGNUM |
4483 | && (! reload_completed || frame_pointer_needed))) | |
d7429b6a RK |
4484 | { |
4485 | /* If this is a register we are going to try to eliminate, | |
4486 | don't mark it live here. If we are successful in | |
4487 | eliminating it, it need not be live unless it is used for | |
4488 | pseudos, in which case it will have been set live when | |
4489 | it was allocated to the pseudos. If the register will not | |
4490 | be eliminated, reload will set it live at that point. */ | |
4491 | ||
3ea8083f JL |
4492 | if ((flags & PROP_REG_INFO) |
4493 | && ! TEST_HARD_REG_BIT (elim_reg_set, regno)) | |
d7429b6a RK |
4494 | regs_ever_live[regno] = 1; |
4495 | return; | |
4496 | } | |
4497 | /* No death notes for global register variables; | |
4498 | their values are live after this function exits. */ | |
4499 | if (global_regs[regno]) | |
d8c8b8e3 | 4500 | { |
d3a923ee | 4501 | if (flags & (PROP_LOG_LINKS | PROP_AUTOINC)) |
d8c8b8e3 RS |
4502 | reg_next_use[regno] = insn; |
4503 | return; | |
4504 | } | |
d7429b6a RK |
4505 | |
4506 | n = HARD_REGNO_NREGS (regno, GET_MODE (x)); | |
4507 | while (--n > 0) | |
4508 | { | |
916b1701 MM |
4509 | int regno_n = regno + n; |
4510 | int needed_regno = REGNO_REG_SET_P (needed, regno_n); | |
cb9e8ad1 | 4511 | |
916b1701 MM |
4512 | SET_REGNO_REG_SET (live, regno_n); |
4513 | some_needed |= needed_regno; | |
931c6c7a | 4514 | some_not_needed |= ! needed_regno; |
d7429b6a RK |
4515 | } |
4516 | } | |
d3a923ee RH |
4517 | |
4518 | if (flags & (PROP_LOG_LINKS | PROP_AUTOINC)) | |
d7429b6a RK |
4519 | { |
4520 | /* Record where each reg is used, so when the reg | |
4521 | is set we know the next insn that uses it. */ | |
4522 | ||
4523 | reg_next_use[regno] = insn; | |
d3a923ee RH |
4524 | } |
4525 | if (flags & PROP_REG_INFO) | |
4526 | { | |
d7429b6a RK |
4527 | if (regno < FIRST_PSEUDO_REGISTER) |
4528 | { | |
4529 | /* If a hard reg is being used, | |
4530 | record that this function does use it. */ | |
4531 | ||
4532 | i = HARD_REGNO_NREGS (regno, GET_MODE (x)); | |
4533 | if (i == 0) | |
4534 | i = 1; | |
4535 | do | |
4536 | regs_ever_live[regno + --i] = 1; | |
4537 | while (i > 0); | |
4538 | } | |
4539 | else | |
4540 | { | |
4541 | /* Keep track of which basic block each reg appears in. */ | |
4542 | ||
4543 | register int blocknum = BLOCK_NUM (insn); | |
4544 | ||
b1f21e0a MM |
4545 | if (REG_BASIC_BLOCK (regno) == REG_BLOCK_UNKNOWN) |
4546 | REG_BASIC_BLOCK (regno) = blocknum; | |
4547 | else if (REG_BASIC_BLOCK (regno) != blocknum) | |
4548 | REG_BASIC_BLOCK (regno) = REG_BLOCK_GLOBAL; | |
d7429b6a RK |
4549 | |
4550 | /* Count (weighted) number of uses of each reg. */ | |
4551 | ||
9b15c17f | 4552 | REG_N_REFS (regno) += loop_depth + 1; |
d7429b6a | 4553 | } |
d3a923ee | 4554 | } |
d7429b6a | 4555 | |
d3a923ee RH |
4556 | /* Record and count the insns in which a reg dies. |
4557 | If it is used in this insn and was dead below the insn | |
4558 | then it dies in this insn. If it was set in this insn, | |
4559 | we do not make a REG_DEAD note; likewise if we already | |
4560 | made such a note. */ | |
d7429b6a | 4561 | |
d3a923ee RH |
4562 | if (flags & PROP_DEATH_NOTES) |
4563 | { | |
cb9e8ad1 | 4564 | if (some_not_needed |
d7429b6a RK |
4565 | && ! dead_or_set_p (insn, x) |
4566 | #if 0 | |
4567 | && (regno >= FIRST_PSEUDO_REGISTER || ! fixed_regs[regno]) | |
4568 | #endif | |
4569 | ) | |
4570 | { | |
ab28041e JW |
4571 | /* Check for the case where the register dying partially |
4572 | overlaps the register set by this insn. */ | |
4573 | if (regno < FIRST_PSEUDO_REGISTER | |
4574 | && HARD_REGNO_NREGS (regno, GET_MODE (x)) > 1) | |
4575 | { | |
480eac3b | 4576 | int n = HARD_REGNO_NREGS (regno, GET_MODE (x)); |
ab28041e JW |
4577 | while (--n >= 0) |
4578 | some_needed |= dead_or_set_regno_p (insn, regno + n); | |
4579 | } | |
4580 | ||
d7429b6a RK |
4581 | /* If none of the words in X is needed, make a REG_DEAD |
4582 | note. Otherwise, we must make partial REG_DEAD notes. */ | |
4583 | if (! some_needed) | |
4584 | { | |
4585 | REG_NOTES (insn) | |
d3a923ee | 4586 | = alloc_EXPR_LIST (REG_DEAD, x, REG_NOTES (insn)); |
b1f21e0a | 4587 | REG_N_DEATHS (regno)++; |
d7429b6a RK |
4588 | } |
4589 | else | |
4590 | { | |
4591 | int i; | |
4592 | ||
4593 | /* Don't make a REG_DEAD note for a part of a register | |
4594 | that is set in the insn. */ | |
4595 | ||
4596 | for (i = HARD_REGNO_NREGS (regno, GET_MODE (x)) - 1; | |
4597 | i >= 0; i--) | |
916b1701 | 4598 | if (!REGNO_REG_SET_P (needed, regno + i) |
d7429b6a RK |
4599 | && ! dead_or_set_regno_p (insn, regno + i)) |
4600 | REG_NOTES (insn) | |
d3a923ee RH |
4601 | = (alloc_EXPR_LIST |
4602 | (REG_DEAD, gen_rtx_REG (reg_raw_mode[regno + i], | |
4603 | regno + i), | |
4604 | REG_NOTES (insn))); | |
d7429b6a RK |
4605 | } |
4606 | } | |
4607 | } | |
4608 | } | |
4609 | return; | |
4610 | ||
4611 | case SET: | |
4612 | { | |
4613 | register rtx testreg = SET_DEST (x); | |
4614 | int mark_dest = 0; | |
4615 | ||
4616 | /* If storing into MEM, don't show it as being used. But do | |
4617 | show the address as being used. */ | |
4618 | if (GET_CODE (testreg) == MEM) | |
4619 | { | |
4620 | #ifdef AUTO_INC_DEC | |
d3a923ee | 4621 | if (flags & PROP_AUTOINC) |
d7429b6a RK |
4622 | find_auto_inc (needed, testreg, insn); |
4623 | #endif | |
d3a923ee RH |
4624 | mark_used_regs (needed, live, XEXP (testreg, 0), flags, insn); |
4625 | mark_used_regs (needed, live, SET_SRC (x), flags, insn); | |
d7429b6a RK |
4626 | return; |
4627 | } | |
4628 | ||
4629 | /* Storing in STRICT_LOW_PART is like storing in a reg | |
4630 | in that this SET might be dead, so ignore it in TESTREG. | |
4631 | but in some other ways it is like using the reg. | |
4632 | ||
4633 | Storing in a SUBREG or a bit field is like storing the entire | |
4634 | register in that if the register's value is not used | |
4635 | then this SET is not needed. */ | |
4636 | while (GET_CODE (testreg) == STRICT_LOW_PART | |
4637 | || GET_CODE (testreg) == ZERO_EXTRACT | |
4638 | || GET_CODE (testreg) == SIGN_EXTRACT | |
4639 | || GET_CODE (testreg) == SUBREG) | |
4640 | { | |
88285acf RK |
4641 | if (GET_CODE (testreg) == SUBREG |
4642 | && GET_CODE (SUBREG_REG (testreg)) == REG | |
4643 | && REGNO (SUBREG_REG (testreg)) >= FIRST_PSEUDO_REGISTER | |
4644 | && (GET_MODE_SIZE (GET_MODE (testreg)) | |
4645 | != GET_MODE_SIZE (GET_MODE (SUBREG_REG (testreg))))) | |
b1f21e0a | 4646 | REG_CHANGES_SIZE (REGNO (SUBREG_REG (testreg))) = 1; |
88285acf | 4647 | |
d7429b6a RK |
4648 | /* Modifying a single register in an alternate mode |
4649 | does not use any of the old value. But these other | |
4650 | ways of storing in a register do use the old value. */ | |
4651 | if (GET_CODE (testreg) == SUBREG | |
4652 | && !(REG_SIZE (SUBREG_REG (testreg)) > REG_SIZE (testreg))) | |
4653 | ; | |
4654 | else | |
4655 | mark_dest = 1; | |
4656 | ||
4657 | testreg = XEXP (testreg, 0); | |
4658 | } | |
4659 | ||
4660 | /* If this is a store into a register, | |
4661 | recursively scan the value being stored. */ | |
4662 | ||
86465af7 DM |
4663 | if ((GET_CODE (testreg) == PARALLEL |
4664 | && GET_MODE (testreg) == BLKmode) | |
4665 | || (GET_CODE (testreg) == REG | |
e4b8a413 JW |
4666 | && (regno = REGNO (testreg), ! (regno == FRAME_POINTER_REGNUM |
4667 | && (! reload_completed || frame_pointer_needed))) | |
73a187c1 | 4668 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
e4b8a413 JW |
4669 | && ! (regno == HARD_FRAME_POINTER_REGNUM |
4670 | && (! reload_completed || frame_pointer_needed)) | |
73a187c1 | 4671 | #endif |
d7e4fe8b | 4672 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
86465af7 | 4673 | && ! (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) |
d7e4fe8b | 4674 | #endif |
86465af7 | 4675 | )) |
d8c8b8e3 RS |
4676 | /* We used to exclude global_regs here, but that seems wrong. |
4677 | Storing in them is like storing in mem. */ | |
d7429b6a | 4678 | { |
d3a923ee | 4679 | mark_used_regs (needed, live, SET_SRC (x), flags, insn); |
d7429b6a | 4680 | if (mark_dest) |
d3a923ee | 4681 | mark_used_regs (needed, live, SET_DEST (x), flags, insn); |
d7429b6a RK |
4682 | return; |
4683 | } | |
4684 | } | |
4685 | break; | |
4686 | ||
40b5a77c JL |
4687 | case ASM_OPERANDS: |
4688 | case UNSPEC_VOLATILE: | |
4689 | case TRAP_IF: | |
4690 | case ASM_INPUT: | |
4691 | { | |
4692 | /* Traditional and volatile asm instructions must be considered to use | |
4693 | and clobber all hard registers, all pseudo-registers and all of | |
4694 | memory. So must TRAP_IF and UNSPEC_VOLATILE operations. | |
4695 | ||
4696 | Consider for instance a volatile asm that changes the fpu rounding | |
4697 | mode. An insn should not be moved across this even if it only uses | |
4698 | pseudo-regs because it might give an incorrectly rounded result. | |
4699 | ||
4700 | ?!? Unfortunately, marking all hard registers as live causes massive | |
4701 | problems for the register allocator and marking all pseudos as live | |
4702 | creates mountains of uninitialized variable warnings. | |
4703 | ||
4704 | So for now, just clear the memory set list and mark any regs | |
4705 | we can find in ASM_OPERANDS as used. */ | |
4706 | if (code != ASM_OPERANDS || MEM_VOLATILE_P (x)) | |
ff666313 | 4707 | free_EXPR_LIST_list (&mem_set_list); |
40b5a77c JL |
4708 | |
4709 | /* For all ASM_OPERANDS, we must traverse the vector of input operands. | |
4710 | We can not just fall through here since then we would be confused | |
4711 | by the ASM_INPUT rtx inside ASM_OPERANDS, which do not indicate | |
4712 | traditional asms unlike their normal usage. */ | |
4713 | if (code == ASM_OPERANDS) | |
4714 | { | |
4715 | int j; | |
4716 | ||
4717 | for (j = 0; j < ASM_OPERANDS_INPUT_LENGTH (x); j++) | |
4718 | mark_used_regs (needed, live, ASM_OPERANDS_INPUT (x, j), | |
d3a923ee | 4719 | flags, insn); |
40b5a77c JL |
4720 | } |
4721 | break; | |
4722 | } | |
4723 | ||
4e872036 AS |
4724 | case PHI: |
4725 | /* We _do_not_ want to scan operands of phi nodes. Operands of | |
4726 | a phi function are evaluated only when control reaches this | |
4727 | block along a particular edge. Therefore, regs that appear | |
4728 | as arguments to phi should not be added to the global live at | |
4729 | start. */ | |
4730 | return; | |
40b5a77c | 4731 | |
e9a25f70 JL |
4732 | default: |
4733 | break; | |
d7429b6a RK |
4734 | } |
4735 | ||
4736 | /* Recursively scan the operands of this expression. */ | |
4737 | ||
4738 | { | |
6f7d635c | 4739 | register const char *fmt = GET_RTX_FORMAT (code); |
d7429b6a RK |
4740 | register int i; |
4741 | ||
4742 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
4743 | { | |
4744 | if (fmt[i] == 'e') | |
4745 | { | |
4746 | /* Tail recursive case: save a function call level. */ | |
4747 | if (i == 0) | |
4748 | { | |
4749 | x = XEXP (x, 0); | |
4750 | goto retry; | |
4751 | } | |
d3a923ee | 4752 | mark_used_regs (needed, live, XEXP (x, i), flags, insn); |
d7429b6a RK |
4753 | } |
4754 | else if (fmt[i] == 'E') | |
4755 | { | |
4756 | register int j; | |
4757 | for (j = 0; j < XVECLEN (x, i); j++) | |
d3a923ee | 4758 | mark_used_regs (needed, live, XVECEXP (x, i, j), flags, insn); |
d7429b6a RK |
4759 | } |
4760 | } | |
4761 | } | |
4762 | } | |
4763 | \f | |
4764 | #ifdef AUTO_INC_DEC | |
4765 | ||
4766 | static int | |
4767 | try_pre_increment_1 (insn) | |
4768 | rtx insn; | |
4769 | { | |
4770 | /* Find the next use of this reg. If in same basic block, | |
4771 | make it do pre-increment or pre-decrement if appropriate. */ | |
956d6950 | 4772 | rtx x = single_set (insn); |
5f4f0e22 | 4773 | HOST_WIDE_INT amount = ((GET_CODE (SET_SRC (x)) == PLUS ? 1 : -1) |
d7429b6a RK |
4774 | * INTVAL (XEXP (SET_SRC (x), 1))); |
4775 | int regno = REGNO (SET_DEST (x)); | |
4776 | rtx y = reg_next_use[regno]; | |
4777 | if (y != 0 | |
4778 | && BLOCK_NUM (y) == BLOCK_NUM (insn) | |
89861c38 | 4779 | /* Don't do this if the reg dies, or gets set in y; a standard addressing |
0f41302f | 4780 | mode would be better. */ |
89861c38 | 4781 | && ! dead_or_set_p (y, SET_DEST (x)) |
956d6950 | 4782 | && try_pre_increment (y, SET_DEST (x), amount)) |
d7429b6a RK |
4783 | { |
4784 | /* We have found a suitable auto-increment | |
4785 | and already changed insn Y to do it. | |
4786 | So flush this increment-instruction. */ | |
4787 | PUT_CODE (insn, NOTE); | |
4788 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
4789 | NOTE_SOURCE_FILE (insn) = 0; | |
4790 | /* Count a reference to this reg for the increment | |
4791 | insn we are deleting. When a reg is incremented. | |
4792 | spilling it is worse, so we want to make that | |
4793 | less likely. */ | |
4794 | if (regno >= FIRST_PSEUDO_REGISTER) | |
4795 | { | |
9b15c17f | 4796 | REG_N_REFS (regno) += loop_depth + 1; |
b1f21e0a | 4797 | REG_N_SETS (regno)++; |
d7429b6a RK |
4798 | } |
4799 | return 1; | |
4800 | } | |
4801 | return 0; | |
4802 | } | |
4803 | ||
4804 | /* Try to change INSN so that it does pre-increment or pre-decrement | |
4805 | addressing on register REG in order to add AMOUNT to REG. | |
4806 | AMOUNT is negative for pre-decrement. | |
4807 | Returns 1 if the change could be made. | |
4808 | This checks all about the validity of the result of modifying INSN. */ | |
4809 | ||
4810 | static int | |
4811 | try_pre_increment (insn, reg, amount) | |
4812 | rtx insn, reg; | |
5f4f0e22 | 4813 | HOST_WIDE_INT amount; |
d7429b6a RK |
4814 | { |
4815 | register rtx use; | |
4816 | ||
4817 | /* Nonzero if we can try to make a pre-increment or pre-decrement. | |
4818 | For example, addl $4,r1; movl (r1),... can become movl +(r1),... */ | |
4819 | int pre_ok = 0; | |
4820 | /* Nonzero if we can try to make a post-increment or post-decrement. | |
4821 | For example, addl $4,r1; movl -4(r1),... can become movl (r1)+,... | |
4822 | It is possible for both PRE_OK and POST_OK to be nonzero if the machine | |
4823 | supports both pre-inc and post-inc, or both pre-dec and post-dec. */ | |
4824 | int post_ok = 0; | |
4825 | ||
4826 | /* Nonzero if the opportunity actually requires post-inc or post-dec. */ | |
4827 | int do_post = 0; | |
4828 | ||
4829 | /* From the sign of increment, see which possibilities are conceivable | |
4830 | on this target machine. */ | |
940da324 | 4831 | if (HAVE_PRE_INCREMENT && amount > 0) |
d7429b6a | 4832 | pre_ok = 1; |
940da324 | 4833 | if (HAVE_POST_INCREMENT && amount > 0) |
d7429b6a | 4834 | post_ok = 1; |
d7429b6a | 4835 | |
940da324 | 4836 | if (HAVE_PRE_DECREMENT && amount < 0) |
d7429b6a | 4837 | pre_ok = 1; |
940da324 | 4838 | if (HAVE_POST_DECREMENT && amount < 0) |
d7429b6a | 4839 | post_ok = 1; |
d7429b6a RK |
4840 | |
4841 | if (! (pre_ok || post_ok)) | |
4842 | return 0; | |
4843 | ||
4844 | /* It is not safe to add a side effect to a jump insn | |
4845 | because if the incremented register is spilled and must be reloaded | |
4846 | there would be no way to store the incremented value back in memory. */ | |
4847 | ||
4848 | if (GET_CODE (insn) == JUMP_INSN) | |
4849 | return 0; | |
4850 | ||
4851 | use = 0; | |
4852 | if (pre_ok) | |
4853 | use = find_use_as_address (PATTERN (insn), reg, 0); | |
4854 | if (post_ok && (use == 0 || use == (rtx) 1)) | |
4855 | { | |
4856 | use = find_use_as_address (PATTERN (insn), reg, -amount); | |
4857 | do_post = 1; | |
4858 | } | |
4859 | ||
4860 | if (use == 0 || use == (rtx) 1) | |
4861 | return 0; | |
4862 | ||
4863 | if (GET_MODE_SIZE (GET_MODE (use)) != (amount > 0 ? amount : - amount)) | |
4864 | return 0; | |
4865 | ||
a0fbc3a9 SC |
4866 | /* See if this combination of instruction and addressing mode exists. */ |
4867 | if (! validate_change (insn, &XEXP (use, 0), | |
38a448ca RH |
4868 | gen_rtx_fmt_e (amount > 0 |
4869 | ? (do_post ? POST_INC : PRE_INC) | |
4870 | : (do_post ? POST_DEC : PRE_DEC), | |
4871 | Pmode, reg), 0)) | |
a0fbc3a9 | 4872 | return 0; |
d7429b6a RK |
4873 | |
4874 | /* Record that this insn now has an implicit side effect on X. */ | |
d3a923ee | 4875 | REG_NOTES (insn) = alloc_EXPR_LIST (REG_INC, reg, REG_NOTES (insn)); |
d7429b6a RK |
4876 | return 1; |
4877 | } | |
4878 | ||
4879 | #endif /* AUTO_INC_DEC */ | |
4880 | \f | |
4881 | /* Find the place in the rtx X where REG is used as a memory address. | |
4882 | Return the MEM rtx that so uses it. | |
4883 | If PLUSCONST is nonzero, search instead for a memory address equivalent to | |
4884 | (plus REG (const_int PLUSCONST)). | |
4885 | ||
4886 | If such an address does not appear, return 0. | |
4887 | If REG appears more than once, or is used other than in such an address, | |
4888 | return (rtx)1. */ | |
4889 | ||
8c660648 | 4890 | rtx |
d7429b6a RK |
4891 | find_use_as_address (x, reg, plusconst) |
4892 | register rtx x; | |
4893 | rtx reg; | |
e658434c | 4894 | HOST_WIDE_INT plusconst; |
d7429b6a RK |
4895 | { |
4896 | enum rtx_code code = GET_CODE (x); | |
6f7d635c | 4897 | const char *fmt = GET_RTX_FORMAT (code); |
d7429b6a RK |
4898 | register int i; |
4899 | register rtx value = 0; | |
4900 | register rtx tem; | |
4901 | ||
4902 | if (code == MEM && XEXP (x, 0) == reg && plusconst == 0) | |
4903 | return x; | |
4904 | ||
4905 | if (code == MEM && GET_CODE (XEXP (x, 0)) == PLUS | |
4906 | && XEXP (XEXP (x, 0), 0) == reg | |
4907 | && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT | |
4908 | && INTVAL (XEXP (XEXP (x, 0), 1)) == plusconst) | |
4909 | return x; | |
4910 | ||
4911 | if (code == SIGN_EXTRACT || code == ZERO_EXTRACT) | |
4912 | { | |
4913 | /* If REG occurs inside a MEM used in a bit-field reference, | |
4914 | that is unacceptable. */ | |
4915 | if (find_use_as_address (XEXP (x, 0), reg, 0) != 0) | |
6fa5c106 | 4916 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
4917 | } |
4918 | ||
4919 | if (x == reg) | |
6fa5c106 | 4920 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
4921 | |
4922 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
4923 | { | |
4924 | if (fmt[i] == 'e') | |
4925 | { | |
4926 | tem = find_use_as_address (XEXP (x, i), reg, plusconst); | |
4927 | if (value == 0) | |
4928 | value = tem; | |
4929 | else if (tem != 0) | |
6fa5c106 | 4930 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a | 4931 | } |
d4757e6a | 4932 | else if (fmt[i] == 'E') |
d7429b6a RK |
4933 | { |
4934 | register int j; | |
4935 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
4936 | { | |
4937 | tem = find_use_as_address (XVECEXP (x, i, j), reg, plusconst); | |
4938 | if (value == 0) | |
4939 | value = tem; | |
4940 | else if (tem != 0) | |
6fa5c106 | 4941 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
4942 | } |
4943 | } | |
4944 | } | |
4945 | ||
4946 | return value; | |
4947 | } | |
4948 | \f | |
4949 | /* Write information about registers and basic blocks into FILE. | |
4950 | This is part of making a debugging dump. */ | |
4951 | ||
b7ba4d8d ZW |
4952 | void |
4953 | dump_regset (r, outf) | |
4954 | regset r; | |
4955 | FILE *outf; | |
4956 | { | |
4957 | int i; | |
4958 | if (r == NULL) | |
4959 | { | |
4960 | fputs (" (nil)", outf); | |
4961 | return; | |
4962 | } | |
4963 | ||
4964 | EXECUTE_IF_SET_IN_REG_SET (r, 0, i, | |
4965 | { | |
4966 | fprintf (outf, " %d", i); | |
4967 | if (i < FIRST_PSEUDO_REGISTER) | |
4968 | fprintf (outf, " [%s]", | |
4969 | reg_names[i]); | |
4970 | }); | |
4971 | } | |
4972 | ||
4973 | void | |
4974 | debug_regset (r) | |
4975 | regset r; | |
4976 | { | |
4977 | dump_regset (r, stderr); | |
4978 | putc ('\n', stderr); | |
4979 | } | |
4980 | ||
d7429b6a RK |
4981 | void |
4982 | dump_flow_info (file) | |
4983 | FILE *file; | |
4984 | { | |
4985 | register int i; | |
6f7d635c | 4986 | static const char * const reg_class_names[] = REG_CLASS_NAMES; |
d7429b6a RK |
4987 | |
4988 | fprintf (file, "%d registers.\n", max_regno); | |
d7429b6a | 4989 | for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) |
b1f21e0a | 4990 | if (REG_N_REFS (i)) |
d7429b6a | 4991 | { |
e4600702 | 4992 | enum reg_class class, altclass; |
d7429b6a | 4993 | fprintf (file, "\nRegister %d used %d times across %d insns", |
b1f21e0a MM |
4994 | i, REG_N_REFS (i), REG_LIVE_LENGTH (i)); |
4995 | if (REG_BASIC_BLOCK (i) >= 0) | |
4996 | fprintf (file, " in block %d", REG_BASIC_BLOCK (i)); | |
6fc4610b MM |
4997 | if (REG_N_SETS (i)) |
4998 | fprintf (file, "; set %d time%s", REG_N_SETS (i), | |
4999 | (REG_N_SETS (i) == 1) ? "" : "s"); | |
5000 | if (REG_USERVAR_P (regno_reg_rtx[i])) | |
5001 | fprintf (file, "; user var"); | |
b1f21e0a MM |
5002 | if (REG_N_DEATHS (i) != 1) |
5003 | fprintf (file, "; dies in %d places", REG_N_DEATHS (i)); | |
5004 | if (REG_N_CALLS_CROSSED (i) == 1) | |
d7429b6a | 5005 | fprintf (file, "; crosses 1 call"); |
b1f21e0a MM |
5006 | else if (REG_N_CALLS_CROSSED (i)) |
5007 | fprintf (file, "; crosses %d calls", REG_N_CALLS_CROSSED (i)); | |
d7429b6a RK |
5008 | if (PSEUDO_REGNO_BYTES (i) != UNITS_PER_WORD) |
5009 | fprintf (file, "; %d bytes", PSEUDO_REGNO_BYTES (i)); | |
5010 | class = reg_preferred_class (i); | |
e4600702 RK |
5011 | altclass = reg_alternate_class (i); |
5012 | if (class != GENERAL_REGS || altclass != ALL_REGS) | |
d7429b6a | 5013 | { |
e4600702 RK |
5014 | if (altclass == ALL_REGS || class == ALL_REGS) |
5015 | fprintf (file, "; pref %s", reg_class_names[(int) class]); | |
5016 | else if (altclass == NO_REGS) | |
d7429b6a RK |
5017 | fprintf (file, "; %s or none", reg_class_names[(int) class]); |
5018 | else | |
e4600702 RK |
5019 | fprintf (file, "; pref %s, else %s", |
5020 | reg_class_names[(int) class], | |
5021 | reg_class_names[(int) altclass]); | |
d7429b6a RK |
5022 | } |
5023 | if (REGNO_POINTER_FLAG (i)) | |
5024 | fprintf (file, "; pointer"); | |
5025 | fprintf (file, ".\n"); | |
5026 | } | |
e881bb1b | 5027 | |
d3a923ee | 5028 | fprintf (file, "\n%d basic blocks, %d edges.\n", n_basic_blocks, n_edges); |
e881bb1b RH |
5029 | for (i = 0; i < n_basic_blocks; i++) |
5030 | { | |
5031 | register basic_block bb = BASIC_BLOCK (i); | |
e881bb1b RH |
5032 | register edge e; |
5033 | ||
ce4bbac7 JH |
5034 | fprintf (file, "\nBasic block %d: first insn %d, last %d, loop_depth %d.\n", |
5035 | i, INSN_UID (bb->head), INSN_UID (bb->end), bb->loop_depth); | |
e881bb1b RH |
5036 | |
5037 | fprintf (file, "Predecessors: "); | |
5038 | for (e = bb->pred; e ; e = e->pred_next) | |
5039 | dump_edge_info (file, e, 0); | |
5040 | ||
5041 | fprintf (file, "\nSuccessors: "); | |
5042 | for (e = bb->succ; e ; e = e->succ_next) | |
5043 | dump_edge_info (file, e, 1); | |
5044 | ||
5045 | fprintf (file, "\nRegisters live at start:"); | |
b7ba4d8d | 5046 | dump_regset (bb->global_live_at_start, file); |
e881bb1b RH |
5047 | |
5048 | fprintf (file, "\nRegisters live at end:"); | |
b7ba4d8d | 5049 | dump_regset (bb->global_live_at_end, file); |
e881bb1b RH |
5050 | |
5051 | putc('\n', file); | |
5052 | } | |
5053 | ||
5054 | putc('\n', file); | |
5055 | } | |
5056 | ||
93cba993 RH |
5057 | void |
5058 | debug_flow_info () | |
5059 | { | |
5060 | dump_flow_info (stderr); | |
5061 | } | |
5062 | ||
e881bb1b RH |
5063 | static void |
5064 | dump_edge_info (file, e, do_succ) | |
5065 | FILE *file; | |
5066 | edge e; | |
5067 | int do_succ; | |
5068 | { | |
5069 | basic_block side = (do_succ ? e->dest : e->src); | |
5070 | ||
5071 | if (side == ENTRY_BLOCK_PTR) | |
5072 | fputs (" ENTRY", file); | |
5073 | else if (side == EXIT_BLOCK_PTR) | |
5074 | fputs (" EXIT", file); | |
5075 | else | |
5076 | fprintf (file, " %d", side->index); | |
5077 | ||
5078 | if (e->flags) | |
5079 | { | |
6f7d635c | 5080 | static const char * const bitnames[] = { |
e881bb1b RH |
5081 | "fallthru", "crit", "ab", "abcall", "eh", "fake" |
5082 | }; | |
5083 | int comma = 0; | |
5084 | int i, flags = e->flags; | |
5085 | ||
5086 | fputc (' ', file); | |
5087 | fputc ('(', file); | |
5088 | for (i = 0; flags; i++) | |
5089 | if (flags & (1 << i)) | |
5090 | { | |
5091 | flags &= ~(1 << i); | |
5092 | ||
5093 | if (comma) | |
5094 | fputc (',', file); | |
5095 | if (i < (int)(sizeof (bitnames) / sizeof (*bitnames))) | |
5096 | fputs (bitnames[i], file); | |
5097 | else | |
5098 | fprintf (file, "%d", i); | |
5099 | comma = 1; | |
5100 | } | |
5101 | fputc (')', file); | |
5102 | } | |
d7429b6a | 5103 | } |
3e28fe44 MM |
5104 | |
5105 | \f | |
b7ba4d8d ZW |
5106 | /* Print out one basic block with live information at start and end. */ |
5107 | void | |
5108 | dump_bb (bb, outf) | |
5109 | basic_block bb; | |
5110 | FILE *outf; | |
5111 | { | |
5112 | rtx insn; | |
5113 | rtx last; | |
5114 | edge e; | |
5115 | ||
5116 | fprintf (outf, ";; Basic block %d, loop depth %d", | |
5117 | bb->index, bb->loop_depth - 1); | |
5118 | if (bb->eh_beg != -1 || bb->eh_end != -1) | |
5119 | fprintf (outf, ", eh regions %d/%d", bb->eh_beg, bb->eh_end); | |
5120 | putc ('\n', outf); | |
5121 | ||
5122 | fputs (";; Predecessors: ", outf); | |
5123 | for (e = bb->pred; e ; e = e->pred_next) | |
5124 | dump_edge_info (outf, e, 0); | |
5125 | putc ('\n', outf); | |
5126 | ||
5127 | fputs (";; Registers live at start:", outf); | |
5128 | dump_regset (bb->global_live_at_start, outf); | |
5129 | putc ('\n', outf); | |
5130 | ||
5131 | for (insn = bb->head, last = NEXT_INSN (bb->end); | |
5132 | insn != last; | |
5133 | insn = NEXT_INSN (insn)) | |
5134 | print_rtl_single (outf, insn); | |
5135 | ||
5136 | fputs (";; Registers live at end:", outf); | |
5137 | dump_regset (bb->global_live_at_end, outf); | |
5138 | putc ('\n', outf); | |
5139 | ||
5140 | fputs (";; Successors: ", outf); | |
5141 | for (e = bb->succ; e; e = e->succ_next) | |
5142 | dump_edge_info (outf, e, 1); | |
5143 | putc ('\n', outf); | |
5144 | } | |
5145 | ||
5146 | void | |
5147 | debug_bb (bb) | |
5148 | basic_block bb; | |
5149 | { | |
5150 | dump_bb (bb, stderr); | |
5151 | } | |
5152 | ||
5153 | void | |
5154 | debug_bb_n (n) | |
5155 | int n; | |
5156 | { | |
5157 | dump_bb (BASIC_BLOCK(n), stderr); | |
5158 | } | |
5159 | ||
3e28fe44 MM |
5160 | /* Like print_rtl, but also print out live information for the start of each |
5161 | basic block. */ | |
5162 | ||
5163 | void | |
5164 | print_rtl_with_bb (outf, rtx_first) | |
5165 | FILE *outf; | |
5166 | rtx rtx_first; | |
5167 | { | |
5168 | register rtx tmp_rtx; | |
5169 | ||
5170 | if (rtx_first == 0) | |
5171 | fprintf (outf, "(nil)\n"); | |
3e28fe44 MM |
5172 | else |
5173 | { | |
e881bb1b | 5174 | int i; |
3e28fe44 MM |
5175 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
5176 | int max_uid = get_max_uid (); | |
54ea1de9 | 5177 | basic_block *start = (basic_block *) |
67289ea6 | 5178 | xcalloc (max_uid, sizeof (basic_block)); |
54ea1de9 | 5179 | basic_block *end = (basic_block *) |
67289ea6 | 5180 | xcalloc (max_uid, sizeof (basic_block)); |
2a92c071 | 5181 | enum bb_state *in_bb_p = (enum bb_state *) |
67289ea6 | 5182 | xcalloc (max_uid, sizeof (enum bb_state)); |
3e28fe44 | 5183 | |
e881bb1b | 5184 | for (i = n_basic_blocks - 1; i >= 0; i--) |
3e28fe44 | 5185 | { |
e881bb1b | 5186 | basic_block bb = BASIC_BLOCK (i); |
3e28fe44 | 5187 | rtx x; |
e881bb1b RH |
5188 | |
5189 | start[INSN_UID (bb->head)] = bb; | |
5190 | end[INSN_UID (bb->end)] = bb; | |
5191 | for (x = bb->head; x != NULL_RTX; x = NEXT_INSN (x)) | |
3e28fe44 | 5192 | { |
e881bb1b RH |
5193 | enum bb_state state = IN_MULTIPLE_BB; |
5194 | if (in_bb_p[INSN_UID(x)] == NOT_IN_BB) | |
5195 | state = IN_ONE_BB; | |
5196 | in_bb_p[INSN_UID(x)] = state; | |
5197 | ||
5198 | if (x == bb->end) | |
3e28fe44 MM |
5199 | break; |
5200 | } | |
5201 | } | |
5202 | ||
5203 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
5204 | { | |
b707b450 | 5205 | int did_output; |
e881bb1b | 5206 | basic_block bb; |
b707b450 | 5207 | |
e881bb1b | 5208 | if ((bb = start[INSN_UID (tmp_rtx)]) != NULL) |
3e28fe44 MM |
5209 | { |
5210 | fprintf (outf, ";; Start of basic block %d, registers live:", | |
e881bb1b | 5211 | bb->index); |
b7ba4d8d | 5212 | dump_regset (bb->global_live_at_start, outf); |
3e28fe44 MM |
5213 | putc ('\n', outf); |
5214 | } | |
5215 | ||
ab87f8c8 | 5216 | if (in_bb_p[INSN_UID(tmp_rtx)] == NOT_IN_BB |
3e28fe44 | 5217 | && GET_CODE (tmp_rtx) != NOTE |
d29c259b | 5218 | && GET_CODE (tmp_rtx) != BARRIER) |
3e28fe44 | 5219 | fprintf (outf, ";; Insn is not within a basic block\n"); |
e881bb1b | 5220 | else if (in_bb_p[INSN_UID(tmp_rtx)] == IN_MULTIPLE_BB) |
3e28fe44 MM |
5221 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); |
5222 | ||
b707b450 | 5223 | did_output = print_rtl_single (outf, tmp_rtx); |
3e28fe44 | 5224 | |
e881bb1b RH |
5225 | if ((bb = end[INSN_UID (tmp_rtx)]) != NULL) |
5226 | fprintf (outf, ";; End of basic block %d\n", bb->index); | |
3e28fe44 | 5227 | |
b707b450 | 5228 | if (did_output) |
9ec36da5 | 5229 | putc ('\n', outf); |
3e28fe44 | 5230 | } |
67289ea6 MM |
5231 | |
5232 | free (start); | |
5233 | free (end); | |
5234 | free (in_bb_p); | |
3e28fe44 | 5235 | } |
c5c76735 JL |
5236 | |
5237 | if (current_function_epilogue_delay_list != 0) | |
5238 | { | |
5239 | fprintf (outf, "\n;; Insns in epilogue delay list:\n\n"); | |
5240 | for (tmp_rtx = current_function_epilogue_delay_list; tmp_rtx != 0; | |
5241 | tmp_rtx = XEXP (tmp_rtx, 1)) | |
5242 | print_rtl_single (outf, XEXP (tmp_rtx, 0)); | |
5243 | } | |
3e28fe44 | 5244 | } |
5ece9746 | 5245 | |
092ae4ba | 5246 | /* Compute dominator relationships using new flow graph structures. */ |
5ece9746 | 5247 | void |
092ae4ba | 5248 | compute_flow_dominators (dominators, post_dominators) |
5ece9746 JL |
5249 | sbitmap *dominators; |
5250 | sbitmap *post_dominators; | |
5ece9746 | 5251 | { |
092ae4ba | 5252 | int bb; |
5ece9746 | 5253 | sbitmap *temp_bitmap; |
092ae4ba | 5254 | edge e; |
987db028 RH |
5255 | basic_block *worklist, *workend, *qin, *qout; |
5256 | int qlen; | |
092ae4ba JL |
5257 | |
5258 | /* Allocate a worklist array/queue. Entries are only added to the | |
5259 | list if they were not already on the list. So the size is | |
5260 | bounded by the number of basic blocks. */ | |
987db028 RH |
5261 | worklist = (basic_block *) xmalloc (sizeof (basic_block) * n_basic_blocks); |
5262 | workend = &worklist[n_basic_blocks]; | |
5ece9746 JL |
5263 | |
5264 | temp_bitmap = sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks); | |
5ece9746 JL |
5265 | sbitmap_vector_zero (temp_bitmap, n_basic_blocks); |
5266 | ||
092ae4ba | 5267 | if (dominators) |
5ece9746 | 5268 | { |
ce724250 JL |
5269 | /* The optimistic setting of dominators requires us to put every |
5270 | block on the work list initially. */ | |
987db028 | 5271 | qin = qout = worklist; |
973d12cb | 5272 | for (bb = 0; bb < n_basic_blocks; bb++) |
ce724250 | 5273 | { |
987db028 | 5274 | *qin++ = BASIC_BLOCK (bb); |
ce724250 JL |
5275 | BASIC_BLOCK (bb)->aux = BASIC_BLOCK (bb); |
5276 | } | |
987db028 RH |
5277 | qlen = n_basic_blocks; |
5278 | qin = worklist; | |
973d12cb JL |
5279 | |
5280 | /* We want a maximal solution, so initially assume everything dominates | |
5281 | everything else. */ | |
092ae4ba | 5282 | sbitmap_vector_ones (dominators, n_basic_blocks); |
092ae4ba | 5283 | |
ce724250 | 5284 | /* Mark successors of the entry block so we can identify them below. */ |
973d12cb | 5285 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) |
ce724250 | 5286 | e->dest->aux = ENTRY_BLOCK_PTR; |
5ece9746 | 5287 | |
092ae4ba | 5288 | /* Iterate until the worklist is empty. */ |
987db028 | 5289 | while (qlen) |
092ae4ba JL |
5290 | { |
5291 | /* Take the first entry off the worklist. */ | |
987db028 RH |
5292 | basic_block b = *qout++; |
5293 | if (qout >= workend) | |
5294 | qout = worklist; | |
5295 | qlen--; | |
5296 | ||
092ae4ba | 5297 | bb = b->index; |
4c649323 | 5298 | |
973d12cb JL |
5299 | /* Compute the intersection of the dominators of all the |
5300 | predecessor blocks. | |
5301 | ||
5302 | If one of the predecessor blocks is the ENTRY block, then the | |
5303 | intersection of the dominators of the predecessor blocks is | |
5304 | defined as the null set. We can identify such blocks by the | |
5305 | special value in the AUX field in the block structure. */ | |
5306 | if (b->aux == ENTRY_BLOCK_PTR) | |
5307 | { | |
5308 | /* Do not clear the aux field for blocks which are | |
5309 | successors of the ENTRY block. That way we we never | |
5310 | add them to the worklist again. | |
5311 | ||
5312 | The intersect of dominators of the preds of this block is | |
5313 | defined as the null set. */ | |
5314 | sbitmap_zero (temp_bitmap[bb]); | |
5315 | } | |
5316 | else | |
5317 | { | |
5318 | /* Clear the aux field of this block so it can be added to | |
5319 | the worklist again if necessary. */ | |
5320 | b->aux = NULL; | |
5321 | sbitmap_intersection_of_preds (temp_bitmap[bb], dominators, bb); | |
5322 | } | |
5323 | ||
5324 | /* Make sure each block always dominates itself. */ | |
092ae4ba | 5325 | SET_BIT (temp_bitmap[bb], bb); |
36349f8b | 5326 | |
092ae4ba JL |
5327 | /* If the out state of this block changed, then we need to |
5328 | add the successors of this block to the worklist if they | |
5329 | are not already on the worklist. */ | |
5330 | if (sbitmap_a_and_b (dominators[bb], dominators[bb], temp_bitmap[bb])) | |
5331 | { | |
5332 | for (e = b->succ; e; e = e->succ_next) | |
5333 | { | |
5334 | if (!e->dest->aux && e->dest != EXIT_BLOCK_PTR) | |
5335 | { | |
987db028 RH |
5336 | *qin++ = e->dest; |
5337 | if (qin >= workend) | |
5338 | qin = worklist; | |
5339 | qlen++; | |
5340 | ||
092ae4ba JL |
5341 | e->dest->aux = e; |
5342 | } | |
5343 | } | |
5344 | } | |
5345 | } | |
5346 | } | |
36349f8b | 5347 | |
092ae4ba JL |
5348 | if (post_dominators) |
5349 | { | |
ce724250 JL |
5350 | /* The optimistic setting of dominators requires us to put every |
5351 | block on the work list initially. */ | |
987db028 | 5352 | qin = qout = worklist; |
973d12cb | 5353 | for (bb = 0; bb < n_basic_blocks; bb++) |
ce724250 | 5354 | { |
987db028 | 5355 | *qin++ = BASIC_BLOCK (bb); |
ce724250 JL |
5356 | BASIC_BLOCK (bb)->aux = BASIC_BLOCK (bb); |
5357 | } | |
987db028 RH |
5358 | qlen = n_basic_blocks; |
5359 | qin = worklist; | |
973d12cb JL |
5360 | |
5361 | /* We want a maximal solution, so initially assume everything post | |
5362 | dominates everything else. */ | |
092ae4ba | 5363 | sbitmap_vector_ones (post_dominators, n_basic_blocks); |
36349f8b | 5364 | |
ce724250 | 5365 | /* Mark predecessors of the exit block so we can identify them below. */ |
973d12cb | 5366 | for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next) |
ce724250 | 5367 | e->src->aux = EXIT_BLOCK_PTR; |
36349f8b | 5368 | |
092ae4ba | 5369 | /* Iterate until the worklist is empty. */ |
987db028 | 5370 | while (qlen) |
36349f8b | 5371 | { |
092ae4ba | 5372 | /* Take the first entry off the worklist. */ |
987db028 RH |
5373 | basic_block b = *qout++; |
5374 | if (qout >= workend) | |
5375 | qout = worklist; | |
5376 | qlen--; | |
5377 | ||
092ae4ba JL |
5378 | bb = b->index; |
5379 | ||
973d12cb JL |
5380 | /* Compute the intersection of the post dominators of all the |
5381 | successor blocks. | |
5382 | ||
5383 | If one of the successor blocks is the EXIT block, then the | |
5384 | intersection of the dominators of the successor blocks is | |
5385 | defined as the null set. We can identify such blocks by the | |
5386 | special value in the AUX field in the block structure. */ | |
5387 | if (b->aux == EXIT_BLOCK_PTR) | |
5388 | { | |
5389 | /* Do not clear the aux field for blocks which are | |
5390 | predecessors of the EXIT block. That way we we never | |
5391 | add them to the worklist again. | |
5392 | ||
5393 | The intersect of dominators of the succs of this block is | |
5394 | defined as the null set. */ | |
5395 | sbitmap_zero (temp_bitmap[bb]); | |
5396 | } | |
5397 | else | |
5398 | { | |
5399 | /* Clear the aux field of this block so it can be added to | |
5400 | the worklist again if necessary. */ | |
5401 | b->aux = NULL; | |
5402 | sbitmap_intersection_of_succs (temp_bitmap[bb], | |
5403 | post_dominators, bb); | |
5404 | } | |
5405 | ||
5406 | /* Make sure each block always post dominates itself. */ | |
36349f8b | 5407 | SET_BIT (temp_bitmap[bb], bb); |
092ae4ba JL |
5408 | |
5409 | /* If the out state of this block changed, then we need to | |
5410 | add the successors of this block to the worklist if they | |
5411 | are not already on the worklist. */ | |
5412 | if (sbitmap_a_and_b (post_dominators[bb], | |
5413 | post_dominators[bb], | |
5414 | temp_bitmap[bb])) | |
5415 | { | |
5416 | for (e = b->pred; e; e = e->pred_next) | |
5417 | { | |
5418 | if (!e->src->aux && e->src != ENTRY_BLOCK_PTR) | |
5419 | { | |
987db028 RH |
5420 | *qin++ = e->src; |
5421 | if (qin >= workend) | |
5422 | qin = worklist; | |
5423 | qlen++; | |
5424 | ||
092ae4ba JL |
5425 | e->src->aux = e; |
5426 | } | |
5427 | } | |
5428 | } | |
36349f8b | 5429 | } |
36349f8b | 5430 | } |
987db028 | 5431 | |
391b788c | 5432 | free (worklist); |
36349f8b AM |
5433 | free (temp_bitmap); |
5434 | } | |
5435 | ||
422d0fb0 RH |
5436 | /* Given DOMINATORS, compute the immediate dominators into IDOM. */ |
5437 | ||
5438 | void | |
5439 | compute_immediate_dominators (idom, dominators) | |
5440 | int *idom; | |
5441 | sbitmap *dominators; | |
5442 | { | |
5443 | sbitmap *tmp; | |
5444 | int b; | |
5445 | ||
5446 | tmp = sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks); | |
5447 | ||
5448 | /* Begin with tmp(n) = dom(n) - { n }. */ | |
5449 | for (b = n_basic_blocks; --b >= 0; ) | |
5450 | { | |
5451 | sbitmap_copy (tmp[b], dominators[b]); | |
5452 | RESET_BIT (tmp[b], b); | |
5453 | } | |
5454 | ||
5455 | /* Subtract out all of our dominator's dominators. */ | |
5456 | for (b = n_basic_blocks; --b >= 0; ) | |
5457 | { | |
5458 | sbitmap tmp_b = tmp[b]; | |
5459 | int s; | |
5460 | ||
5461 | for (s = n_basic_blocks; --s >= 0; ) | |
5462 | if (TEST_BIT (tmp_b, s)) | |
5463 | sbitmap_difference (tmp_b, tmp_b, tmp[s]); | |
5464 | } | |
5465 | ||
5466 | /* Find the one bit set in the bitmap and put it in the output array. */ | |
5467 | for (b = n_basic_blocks; --b >= 0; ) | |
5468 | { | |
5469 | int t; | |
5470 | EXECUTE_IF_SET_IN_SBITMAP (tmp[b], 0, t, { idom[b] = t; }); | |
5471 | } | |
5472 | ||
5473 | sbitmap_vector_free (tmp); | |
5474 | } | |
5475 | ||
4c649323 JL |
5476 | /* Count for a single SET rtx, X. */ |
5477 | ||
5478 | static void | |
5479 | count_reg_sets_1 (x) | |
5480 | rtx x; | |
5481 | { | |
5482 | register int regno; | |
5483 | register rtx reg = SET_DEST (x); | |
5484 | ||
5485 | /* Find the register that's set/clobbered. */ | |
5486 | while (GET_CODE (reg) == SUBREG || GET_CODE (reg) == ZERO_EXTRACT | |
5487 | || GET_CODE (reg) == SIGN_EXTRACT | |
5488 | || GET_CODE (reg) == STRICT_LOW_PART) | |
5489 | reg = XEXP (reg, 0); | |
5490 | ||
86465af7 DM |
5491 | if (GET_CODE (reg) == PARALLEL |
5492 | && GET_MODE (reg) == BLKmode) | |
5493 | { | |
5494 | register int i; | |
5495 | for (i = XVECLEN (reg, 0) - 1; i >= 0; i--) | |
5496 | count_reg_sets_1 (XVECEXP (reg, 0, i)); | |
5497 | return; | |
5498 | } | |
5499 | ||
4c649323 JL |
5500 | if (GET_CODE (reg) == REG) |
5501 | { | |
5502 | regno = REGNO (reg); | |
5503 | if (regno >= FIRST_PSEUDO_REGISTER) | |
5504 | { | |
5505 | /* Count (weighted) references, stores, etc. This counts a | |
5506 | register twice if it is modified, but that is correct. */ | |
5507 | REG_N_SETS (regno)++; | |
9b15c17f | 5508 | REG_N_REFS (regno) += loop_depth + 1; |
4c649323 JL |
5509 | } |
5510 | } | |
5511 | } | |
5512 | ||
5513 | /* Increment REG_N_SETS for each SET or CLOBBER found in X; also increment | |
5514 | REG_N_REFS by the current loop depth for each SET or CLOBBER found. */ | |
5515 | ||
5516 | static void | |
5517 | count_reg_sets (x) | |
5518 | rtx x; | |
5519 | { | |
5520 | register RTX_CODE code = GET_CODE (x); | |
5521 | ||
5522 | if (code == SET || code == CLOBBER) | |
5523 | count_reg_sets_1 (x); | |
5524 | else if (code == PARALLEL) | |
5525 | { | |
5526 | register int i; | |
5527 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
5528 | { | |
5529 | code = GET_CODE (XVECEXP (x, 0, i)); | |
5530 | if (code == SET || code == CLOBBER) | |
5531 | count_reg_sets_1 (XVECEXP (x, 0, i)); | |
5532 | } | |
5533 | } | |
5534 | } | |
5535 | ||
5536 | /* Increment REG_N_REFS by the current loop depth each register reference | |
5537 | found in X. */ | |
5538 | ||
5539 | static void | |
5540 | count_reg_references (x) | |
5541 | rtx x; | |
5542 | { | |
5543 | register RTX_CODE code; | |
4c649323 JL |
5544 | |
5545 | retry: | |
5546 | code = GET_CODE (x); | |
5547 | switch (code) | |
5548 | { | |
5549 | case LABEL_REF: | |
5550 | case SYMBOL_REF: | |
5551 | case CONST_INT: | |
5552 | case CONST: | |
5553 | case CONST_DOUBLE: | |
5554 | case PC: | |
5555 | case ADDR_VEC: | |
5556 | case ADDR_DIFF_VEC: | |
5557 | case ASM_INPUT: | |
5558 | return; | |
5559 | ||
5560 | #ifdef HAVE_cc0 | |
5561 | case CC0: | |
5562 | return; | |
5563 | #endif | |
5564 | ||
5565 | case CLOBBER: | |
5566 | /* If we are clobbering a MEM, mark any registers inside the address | |
5567 | as being used. */ | |
5568 | if (GET_CODE (XEXP (x, 0)) == MEM) | |
5569 | count_reg_references (XEXP (XEXP (x, 0), 0)); | |
5570 | return; | |
5571 | ||
5572 | case SUBREG: | |
5573 | /* While we're here, optimize this case. */ | |
5574 | x = SUBREG_REG (x); | |
5575 | ||
5576 | /* In case the SUBREG is not of a register, don't optimize */ | |
5577 | if (GET_CODE (x) != REG) | |
5578 | { | |
5579 | count_reg_references (x); | |
5580 | return; | |
5581 | } | |
5582 | ||
5583 | /* ... fall through ... */ | |
5584 | ||
5585 | case REG: | |
5586 | if (REGNO (x) >= FIRST_PSEUDO_REGISTER) | |
9b15c17f | 5587 | REG_N_REFS (REGNO (x)) += loop_depth + 1; |
4c649323 JL |
5588 | return; |
5589 | ||
5590 | case SET: | |
5591 | { | |
5592 | register rtx testreg = SET_DEST (x); | |
5593 | int mark_dest = 0; | |
5594 | ||
5595 | /* If storing into MEM, don't show it as being used. But do | |
5596 | show the address as being used. */ | |
5597 | if (GET_CODE (testreg) == MEM) | |
5598 | { | |
5599 | count_reg_references (XEXP (testreg, 0)); | |
5600 | count_reg_references (SET_SRC (x)); | |
5601 | return; | |
5602 | } | |
5603 | ||
5604 | /* Storing in STRICT_LOW_PART is like storing in a reg | |
5605 | in that this SET might be dead, so ignore it in TESTREG. | |
5606 | but in some other ways it is like using the reg. | |
5607 | ||
5608 | Storing in a SUBREG or a bit field is like storing the entire | |
5609 | register in that if the register's value is not used | |
5610 | then this SET is not needed. */ | |
5611 | while (GET_CODE (testreg) == STRICT_LOW_PART | |
5612 | || GET_CODE (testreg) == ZERO_EXTRACT | |
5613 | || GET_CODE (testreg) == SIGN_EXTRACT | |
5614 | || GET_CODE (testreg) == SUBREG) | |
5615 | { | |
5616 | /* Modifying a single register in an alternate mode | |
5617 | does not use any of the old value. But these other | |
5618 | ways of storing in a register do use the old value. */ | |
5619 | if (GET_CODE (testreg) == SUBREG | |
5620 | && !(REG_SIZE (SUBREG_REG (testreg)) > REG_SIZE (testreg))) | |
5621 | ; | |
5622 | else | |
5623 | mark_dest = 1; | |
5624 | ||
5625 | testreg = XEXP (testreg, 0); | |
5626 | } | |
5627 | ||
5628 | /* If this is a store into a register, | |
5629 | recursively scan the value being stored. */ | |
5630 | ||
86465af7 DM |
5631 | if ((GET_CODE (testreg) == PARALLEL |
5632 | && GET_MODE (testreg) == BLKmode) | |
5633 | || GET_CODE (testreg) == REG) | |
4c649323 JL |
5634 | { |
5635 | count_reg_references (SET_SRC (x)); | |
5636 | if (mark_dest) | |
5637 | count_reg_references (SET_DEST (x)); | |
5638 | return; | |
5639 | } | |
5640 | } | |
5641 | break; | |
5642 | ||
5643 | default: | |
5644 | break; | |
5645 | } | |
5646 | ||
5647 | /* Recursively scan the operands of this expression. */ | |
5648 | ||
5649 | { | |
6f7d635c | 5650 | register const char *fmt = GET_RTX_FORMAT (code); |
4c649323 JL |
5651 | register int i; |
5652 | ||
5653 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
5654 | { | |
5655 | if (fmt[i] == 'e') | |
5656 | { | |
5657 | /* Tail recursive case: save a function call level. */ | |
5658 | if (i == 0) | |
5659 | { | |
5660 | x = XEXP (x, 0); | |
5661 | goto retry; | |
5662 | } | |
5663 | count_reg_references (XEXP (x, i)); | |
5664 | } | |
5665 | else if (fmt[i] == 'E') | |
5666 | { | |
5667 | register int j; | |
5668 | for (j = 0; j < XVECLEN (x, i); j++) | |
5669 | count_reg_references (XVECEXP (x, i, j)); | |
5670 | } | |
5671 | } | |
5672 | } | |
5673 | } | |
5674 | ||
5675 | /* Recompute register set/reference counts immediately prior to register | |
5676 | allocation. | |
5677 | ||
5678 | This avoids problems with set/reference counts changing to/from values | |
5679 | which have special meanings to the register allocators. | |
5680 | ||
5681 | Additionally, the reference counts are the primary component used by the | |
5682 | register allocators to prioritize pseudos for allocation to hard regs. | |
5683 | More accurate reference counts generally lead to better register allocation. | |
5684 | ||
213c4983 | 5685 | F is the first insn to be scanned. |
9b15c17f | 5686 | |
213c4983 | 5687 | LOOP_STEP denotes how much loop_depth should be incremented per |
9b15c17f RH |
5688 | loop nesting level in order to increase the ref count more for |
5689 | references in a loop. | |
213c4983 | 5690 | |
4c649323 JL |
5691 | It might be worthwhile to update REG_LIVE_LENGTH, REG_BASIC_BLOCK and |
5692 | possibly other information which is used by the register allocators. */ | |
5693 | ||
762a1d90 | 5694 | void |
213c4983 | 5695 | recompute_reg_usage (f, loop_step) |
272df862 KG |
5696 | rtx f ATTRIBUTE_UNUSED; |
5697 | int loop_step ATTRIBUTE_UNUSED; | |
4c649323 JL |
5698 | { |
5699 | rtx insn; | |
5700 | int i, max_reg; | |
5dd56a93 | 5701 | int index; |
4c649323 JL |
5702 | |
5703 | /* Clear out the old data. */ | |
5704 | max_reg = max_reg_num (); | |
5705 | for (i = FIRST_PSEUDO_REGISTER; i < max_reg; i++) | |
5706 | { | |
5707 | REG_N_SETS (i) = 0; | |
5708 | REG_N_REFS (i) = 0; | |
5709 | } | |
5710 | ||
5711 | /* Scan each insn in the chain and count how many times each register is | |
5712 | set/used. */ | |
5dd56a93 | 5713 | for (index = 0; index < n_basic_blocks; index++) |
4c649323 | 5714 | { |
5dd56a93 JH |
5715 | basic_block bb = BASIC_BLOCK (index); |
5716 | loop_depth = bb->loop_depth; | |
5717 | for (insn = bb->head; insn; insn = NEXT_INSN (insn)) | |
5718 | { | |
5719 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
5720 | { | |
5721 | rtx links; | |
4c649323 | 5722 | |
5dd56a93 JH |
5723 | /* This call will increment REG_N_SETS for each SET or CLOBBER |
5724 | of a register in INSN. It will also increment REG_N_REFS | |
5725 | by the loop depth for each set of a register in INSN. */ | |
5726 | count_reg_sets (PATTERN (insn)); | |
4c649323 | 5727 | |
5dd56a93 JH |
5728 | /* count_reg_sets does not detect autoincrement address modes, so |
5729 | detect them here by looking at the notes attached to INSN. */ | |
5730 | for (links = REG_NOTES (insn); links; links = XEXP (links, 1)) | |
5731 | { | |
5732 | if (REG_NOTE_KIND (links) == REG_INC) | |
5733 | /* Count (weighted) references, stores, etc. This counts a | |
5734 | register twice if it is modified, but that is correct. */ | |
5735 | REG_N_SETS (REGNO (XEXP (links, 0)))++; | |
5736 | } | |
4c649323 | 5737 | |
5dd56a93 JH |
5738 | /* This call will increment REG_N_REFS by the current loop depth for |
5739 | each reference to a register in INSN. */ | |
5740 | count_reg_references (PATTERN (insn)); | |
4c649323 | 5741 | |
5dd56a93 JH |
5742 | /* count_reg_references will not include counts for arguments to |
5743 | function calls, so detect them here by examining the | |
5744 | CALL_INSN_FUNCTION_USAGE data. */ | |
5745 | if (GET_CODE (insn) == CALL_INSN) | |
5746 | { | |
5747 | rtx note; | |
4c649323 | 5748 | |
5dd56a93 JH |
5749 | for (note = CALL_INSN_FUNCTION_USAGE (insn); |
5750 | note; | |
5751 | note = XEXP (note, 1)) | |
5752 | if (GET_CODE (XEXP (note, 0)) == USE) | |
5753 | count_reg_references (XEXP (XEXP (note, 0), 0)); | |
5754 | } | |
4c649323 | 5755 | } |
5dd56a93 JH |
5756 | if (insn == bb->end) |
5757 | break; | |
4c649323 JL |
5758 | } |
5759 | } | |
5760 | } | |
e881bb1b | 5761 | |
d3a923ee | 5762 | /* Optionally removes all the REG_DEAD and REG_UNUSED notes from a set of |
3071fab5 RH |
5763 | blocks. If BLOCKS is NULL, assume the universal set. Returns a count |
5764 | of the number of registers that died. */ | |
d3a923ee RH |
5765 | |
5766 | int | |
5767 | count_or_remove_death_notes (blocks, kill) | |
5768 | sbitmap blocks; | |
5769 | int kill; | |
5770 | { | |
5771 | int i, count = 0; | |
5772 | ||
5773 | for (i = n_basic_blocks - 1; i >= 0; --i) | |
5774 | { | |
5775 | basic_block bb; | |
5776 | rtx insn; | |
5777 | ||
3071fab5 | 5778 | if (blocks && ! TEST_BIT (blocks, i)) |
d3a923ee RH |
5779 | continue; |
5780 | ||
5781 | bb = BASIC_BLOCK (i); | |
5782 | ||
5783 | for (insn = bb->head; ; insn = NEXT_INSN (insn)) | |
5784 | { | |
5785 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
5786 | { | |
5787 | rtx *pprev = ®_NOTES (insn); | |
5788 | rtx link = *pprev; | |
5789 | ||
5790 | while (link) | |
5791 | { | |
5792 | switch (REG_NOTE_KIND (link)) | |
5793 | { | |
5794 | case REG_DEAD: | |
5795 | if (GET_CODE (XEXP (link, 0)) == REG) | |
5796 | { | |
5797 | rtx reg = XEXP (link, 0); | |
5798 | int n; | |
5799 | ||
5800 | if (REGNO (reg) >= FIRST_PSEUDO_REGISTER) | |
5801 | n = 1; | |
5802 | else | |
5803 | n = HARD_REGNO_NREGS (REGNO (reg), GET_MODE (reg)); | |
5804 | count += n; | |
5805 | } | |
5806 | /* FALLTHRU */ | |
5807 | ||
5808 | case REG_UNUSED: | |
5809 | if (kill) | |
5810 | { | |
5811 | rtx next = XEXP (link, 1); | |
5812 | free_EXPR_LIST_node (link); | |
5813 | *pprev = link = next; | |
5814 | break; | |
5815 | } | |
5816 | /* FALLTHRU */ | |
5817 | ||
5818 | default: | |
5819 | pprev = &XEXP (link, 1); | |
5820 | link = *pprev; | |
5821 | break; | |
5822 | } | |
5823 | } | |
5824 | } | |
5825 | ||
5826 | if (insn == bb->end) | |
5827 | break; | |
5828 | } | |
5829 | } | |
5830 | ||
5831 | return count; | |
5832 | } | |
5833 | ||
e881bb1b RH |
5834 | /* Record INSN's block as BB. */ |
5835 | ||
5836 | void | |
5837 | set_block_for_insn (insn, bb) | |
5838 | rtx insn; | |
5839 | basic_block bb; | |
5840 | { | |
5841 | size_t uid = INSN_UID (insn); | |
5842 | if (uid >= basic_block_for_insn->num_elements) | |
5843 | { | |
5844 | int new_size; | |
5845 | ||
5846 | /* Add one-eighth the size so we don't keep calling xrealloc. */ | |
5847 | new_size = uid + (uid + 7) / 8; | |
5848 | ||
5849 | VARRAY_GROW (basic_block_for_insn, new_size); | |
5850 | } | |
5851 | VARRAY_BB (basic_block_for_insn, uid) = bb; | |
5852 | } | |
5853 | ||
5854 | /* Record INSN's block number as BB. */ | |
5855 | /* ??? This has got to go. */ | |
5856 | ||
5857 | void | |
5858 | set_block_num (insn, bb) | |
5859 | rtx insn; | |
5860 | int bb; | |
5861 | { | |
5862 | set_block_for_insn (insn, BASIC_BLOCK (bb)); | |
5863 | } | |
34487bf8 | 5864 | \f |
d3a923ee RH |
5865 | /* Verify the CFG consistency. This function check some CFG invariants and |
5866 | aborts when something is wrong. Hope that this function will help to | |
5867 | convert many optimization passes to preserve CFG consistent. | |
f2a1bc02 | 5868 | |
d3a923ee | 5869 | Currently it does following checks: |
f2a1bc02 | 5870 | |
d3a923ee RH |
5871 | - test head/end pointers |
5872 | - overlapping of basic blocks | |
5873 | - edge list corectness | |
5874 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) | |
5875 | - tails of basic blocks (ensure that boundary is necesary) | |
5876 | - scans body of the basic block for JUMP_INSN, CODE_LABEL | |
5877 | and NOTE_INSN_BASIC_BLOCK | |
5878 | - check that all insns are in the basic blocks | |
5879 | (except the switch handling code, barriers and notes) | |
0edd203b | 5880 | - check that all returns are followed by barriers |
f2a1bc02 | 5881 | |
d3a923ee RH |
5882 | In future it can be extended check a lot of other stuff as well |
5883 | (reachability of basic blocks, life information, etc. etc.). */ | |
f2a1bc02 | 5884 | |
d3a923ee RH |
5885 | void |
5886 | verify_flow_info () | |
f2a1bc02 | 5887 | { |
d3a923ee RH |
5888 | const int max_uid = get_max_uid (); |
5889 | const rtx rtx_first = get_insns (); | |
5890 | basic_block *bb_info; | |
5891 | rtx x; | |
5892 | int i, err = 0; | |
f2a1bc02 | 5893 | |
67289ea6 | 5894 | bb_info = (basic_block *) xcalloc (max_uid, sizeof (basic_block)); |
f2a1bc02 | 5895 | |
d3a923ee RH |
5896 | /* First pass check head/end pointers and set bb_info array used by |
5897 | later passes. */ | |
5898 | for (i = n_basic_blocks - 1; i >= 0; i--) | |
f2a1bc02 | 5899 | { |
d3a923ee | 5900 | basic_block bb = BASIC_BLOCK (i); |
f2a1bc02 | 5901 | |
d3a923ee RH |
5902 | /* Check the head pointer and make sure that it is pointing into |
5903 | insn list. */ | |
5904 | for (x = rtx_first; x != NULL_RTX; x = NEXT_INSN (x)) | |
5905 | if (x == bb->head) | |
5906 | break; | |
5907 | if (!x) | |
5908 | { | |
5909 | error ("Head insn %d for block %d not found in the insn stream.", | |
5910 | INSN_UID (bb->head), bb->index); | |
5911 | err = 1; | |
5912 | } | |
f2a1bc02 | 5913 | |
d3a923ee RH |
5914 | /* Check the end pointer and make sure that it is pointing into |
5915 | insn list. */ | |
5916 | for (x = bb->head; x != NULL_RTX; x = NEXT_INSN (x)) | |
f2a1bc02 | 5917 | { |
d3a923ee | 5918 | if (bb_info[INSN_UID (x)] != NULL) |
f2a1bc02 | 5919 | { |
d3a923ee RH |
5920 | error ("Insn %d is in multiple basic blocks (%d and %d)", |
5921 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); | |
5922 | err = 1; | |
f2a1bc02 | 5923 | } |
d3a923ee RH |
5924 | bb_info[INSN_UID (x)] = bb; |
5925 | ||
5926 | if (x == bb->end) | |
f2a1bc02 BM |
5927 | break; |
5928 | } | |
d3a923ee RH |
5929 | if (!x) |
5930 | { | |
5931 | error ("End insn %d for block %d not found in the insn stream.", | |
5932 | INSN_UID (bb->end), bb->index); | |
5933 | err = 1; | |
5934 | } | |
f2a1bc02 | 5935 | } |
f2a1bc02 | 5936 | |
d3a923ee RH |
5937 | /* Now check the basic blocks (boundaries etc.) */ |
5938 | for (i = n_basic_blocks - 1; i >= 0; i--) | |
f2a1bc02 | 5939 | { |
d3a923ee RH |
5940 | basic_block bb = BASIC_BLOCK (i); |
5941 | /* Check corectness of edge lists */ | |
5942 | edge e; | |
f2a1bc02 | 5943 | |
d3a923ee RH |
5944 | e = bb->succ; |
5945 | while (e) | |
f2a1bc02 | 5946 | { |
d3a923ee | 5947 | if (e->src != bb) |
f2a1bc02 | 5948 | { |
d3a923ee RH |
5949 | fprintf (stderr, "verify_flow_info: Basic block %d succ edge is corrupted\n", |
5950 | bb->index); | |
5951 | fprintf (stderr, "Predecessor: "); | |
5952 | dump_edge_info (stderr, e, 0); | |
5953 | fprintf (stderr, "\nSuccessor: "); | |
5954 | dump_edge_info (stderr, e, 1); | |
5955 | fflush (stderr); | |
5956 | err = 1; | |
f2a1bc02 | 5957 | } |
d3a923ee | 5958 | if (e->dest != EXIT_BLOCK_PTR) |
f2a1bc02 | 5959 | { |
d3a923ee RH |
5960 | edge e2 = e->dest->pred; |
5961 | while (e2 && e2 != e) | |
5962 | e2 = e2->pred_next; | |
5963 | if (!e2) | |
5964 | { | |
5965 | error ("Basic block %i edge lists are corrupted", bb->index); | |
5966 | err = 1; | |
5967 | } | |
f2a1bc02 | 5968 | } |
d3a923ee | 5969 | e = e->succ_next; |
f2a1bc02 | 5970 | } |
f2a1bc02 | 5971 | |
d3a923ee RH |
5972 | e = bb->pred; |
5973 | while (e) | |
f2a1bc02 | 5974 | { |
d3a923ee | 5975 | if (e->dest != bb) |
f2a1bc02 | 5976 | { |
d3a923ee RH |
5977 | error ("Basic block %d pred edge is corrupted", bb->index); |
5978 | fputs ("Predecessor: ", stderr); | |
5979 | dump_edge_info (stderr, e, 0); | |
5980 | fputs ("\nSuccessor: ", stderr); | |
5981 | dump_edge_info (stderr, e, 1); | |
5982 | fputc ('\n', stderr); | |
5983 | err = 1; | |
34487bf8 RH |
5984 | } |
5985 | if (e->src != ENTRY_BLOCK_PTR) | |
5986 | { | |
5987 | edge e2 = e->src->succ; | |
5988 | while (e2 && e2 != e) | |
5989 | e2 = e2->succ_next; | |
5990 | if (!e2) | |
5991 | { | |
987009bf | 5992 | error ("Basic block %i edge lists are corrupted", bb->index); |
d3a923ee | 5993 | err = 1; |
34487bf8 RH |
5994 | } |
5995 | } | |
5996 | e = e->pred_next; | |
5997 | } | |
5998 | ||
5999 | /* OK pointers are correct. Now check the header of basic | |
6000 | block. It ought to contain optional CODE_LABEL followed | |
6001 | by NOTE_BASIC_BLOCK. */ | |
6002 | x = bb->head; | |
6003 | if (GET_CODE (x) == CODE_LABEL) | |
6004 | { | |
6005 | if (bb->end == x) | |
6006 | { | |
987009bf ZW |
6007 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", |
6008 | bb->index); | |
d3a923ee | 6009 | err = 1; |
34487bf8 RH |
6010 | } |
6011 | x = NEXT_INSN (x); | |
6012 | } | |
6013 | if (GET_CODE (x) != NOTE | |
6014 | || NOTE_LINE_NUMBER (x) != NOTE_INSN_BASIC_BLOCK | |
6015 | || NOTE_BASIC_BLOCK (x) != bb) | |
6016 | { | |
987009bf | 6017 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d\n", |
34487bf8 | 6018 | bb->index); |
d3a923ee | 6019 | err = 1; |
34487bf8 RH |
6020 | } |
6021 | ||
6022 | if (bb->end == x) | |
6023 | { | |
6024 | /* Do checks for empty blocks here */ | |
6025 | } | |
6026 | else | |
6027 | { | |
6028 | x = NEXT_INSN (x); | |
6029 | while (x) | |
6030 | { | |
6031 | if (GET_CODE (x) == NOTE | |
6032 | && NOTE_LINE_NUMBER (x) == NOTE_INSN_BASIC_BLOCK) | |
6033 | { | |
987009bf | 6034 | error ("NOTE_INSN_BASIC_BLOCK %d in the middle of basic block %d", |
34487bf8 | 6035 | INSN_UID (x), bb->index); |
d3a923ee | 6036 | err = 1; |
34487bf8 RH |
6037 | } |
6038 | ||
6039 | if (x == bb->end) | |
6040 | break; | |
6041 | ||
6042 | if (GET_CODE (x) == JUMP_INSN | |
6043 | || GET_CODE (x) == CODE_LABEL | |
6044 | || GET_CODE (x) == BARRIER) | |
6045 | { | |
987009bf ZW |
6046 | error ("In basic block %d:", bb->index); |
6047 | fatal_insn ("Flow control insn inside a basic block", x); | |
34487bf8 RH |
6048 | } |
6049 | ||
6050 | x = NEXT_INSN (x); | |
6051 | } | |
6052 | } | |
6053 | } | |
6054 | ||
6055 | x = rtx_first; | |
6056 | while (x) | |
6057 | { | |
6058 | if (!bb_info[INSN_UID (x)]) | |
6059 | { | |
6060 | switch (GET_CODE (x)) | |
6061 | { | |
6062 | case BARRIER: | |
6063 | case NOTE: | |
6064 | break; | |
6065 | ||
6066 | case CODE_LABEL: | |
6067 | /* An addr_vec is placed outside any block block. */ | |
6068 | if (NEXT_INSN (x) | |
6069 | && GET_CODE (NEXT_INSN (x)) == JUMP_INSN | |
6070 | && (GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_DIFF_VEC | |
6071 | || GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_VEC)) | |
6072 | { | |
6073 | x = NEXT_INSN (x); | |
6074 | } | |
6075 | ||
6076 | /* But in any case, non-deletable labels can appear anywhere. */ | |
6077 | break; | |
6078 | ||
6079 | default: | |
987009bf | 6080 | fatal_insn ("Insn outside basic block", x); |
34487bf8 RH |
6081 | } |
6082 | } | |
6083 | ||
0edd203b JE |
6084 | if (GET_RTX_CLASS (GET_CODE (x)) == 'i' |
6085 | && GET_CODE (x) == JUMP_INSN | |
2ca19d5e | 6086 | && returnjump_p (x) && ! condjump_p (x) |
0edd203b JE |
6087 | && ! (NEXT_INSN (x) && GET_CODE (NEXT_INSN (x)) == BARRIER)) |
6088 | fatal_insn ("Return not followed by barrier", x); | |
6089 | ||
34487bf8 RH |
6090 | x = NEXT_INSN (x); |
6091 | } | |
d3a923ee RH |
6092 | |
6093 | if (err) | |
6094 | abort (); | |
67289ea6 MM |
6095 | |
6096 | /* Clean up. */ | |
6097 | free (bb_info); | |
34487bf8 | 6098 | } |
410538ea AM |
6099 | \f |
6100 | /* Functions to access an edge list with a vector representation. | |
6101 | Enough data is kept such that given an index number, the | |
6102 | pred and succ that edge reprsents can be determined, or | |
6103 | given a pred and a succ, it's index number can be returned. | |
6104 | This allows algorithms which comsume a lot of memory to | |
6105 | represent the normally full matrix of edge (pred,succ) with a | |
6106 | single indexed vector, edge (EDGE_INDEX (pred, succ)), with no | |
6107 | wasted space in the client code due to sparse flow graphs. */ | |
6108 | ||
6109 | /* This functions initializes the edge list. Basically the entire | |
6110 | flowgraph is processed, and all edges are assigned a number, | |
6111 | and the data structure is filed in. */ | |
6112 | struct edge_list * | |
6113 | create_edge_list () | |
6114 | { | |
6115 | struct edge_list *elist; | |
6116 | edge e; | |
6117 | int num_edges; | |
e2bef702 | 6118 | int x; |
410538ea AM |
6119 | int block_count; |
6120 | ||
6121 | block_count = n_basic_blocks + 2; /* Include the entry and exit blocks. */ | |
6122 | ||
6123 | num_edges = 0; | |
6124 | ||
6125 | /* Determine the number of edges in the flow graph by counting successor | |
6126 | edges on each basic block. */ | |
6127 | for (x = 0; x < n_basic_blocks; x++) | |
6128 | { | |
6129 | basic_block bb = BASIC_BLOCK (x); | |
6130 | ||
6131 | for (e = bb->succ; e; e = e->succ_next) | |
6132 | num_edges++; | |
6133 | } | |
6134 | /* Don't forget successors of the entry block. */ | |
6135 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) | |
6136 | num_edges++; | |
6137 | ||
2c852885 | 6138 | elist = (struct edge_list *) xmalloc (sizeof (struct edge_list)); |
410538ea AM |
6139 | elist->num_blocks = block_count; |
6140 | elist->num_edges = num_edges; | |
2c852885 | 6141 | elist->index_to_edge = (edge *) xmalloc (sizeof (edge) * num_edges); |
410538ea AM |
6142 | |
6143 | num_edges = 0; | |
6144 | ||
6145 | /* Follow successors of the entry block, and register these edges. */ | |
6146 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) | |
6147 | { | |
6148 | elist->index_to_edge[num_edges] = e; | |
6149 | num_edges++; | |
6150 | } | |
6151 | ||
6152 | for (x = 0; x < n_basic_blocks; x++) | |
6153 | { | |
6154 | basic_block bb = BASIC_BLOCK (x); | |
6155 | ||
6156 | /* Follow all successors of blocks, and register these edges. */ | |
6157 | for (e = bb->succ; e; e = e->succ_next) | |
6158 | { | |
6159 | elist->index_to_edge[num_edges] = e; | |
6160 | num_edges++; | |
6161 | } | |
6162 | } | |
6163 | return elist; | |
6164 | } | |
6165 | ||
6166 | /* This function free's memory associated with an edge list. */ | |
6167 | void | |
6168 | free_edge_list (elist) | |
6169 | struct edge_list *elist; | |
6170 | { | |
6171 | if (elist) | |
6172 | { | |
6173 | free (elist->index_to_edge); | |
6174 | free (elist); | |
6175 | } | |
6176 | } | |
6177 | ||
6178 | /* This function provides debug output showing an edge list. */ | |
6179 | void | |
6180 | print_edge_list (f, elist) | |
6181 | FILE *f; | |
6182 | struct edge_list *elist; | |
6183 | { | |
6184 | int x; | |
6185 | fprintf(f, "Compressed edge list, %d BBs + entry & exit, and %d edges\n", | |
6186 | elist->num_blocks - 2, elist->num_edges); | |
6187 | ||
6188 | for (x = 0; x < elist->num_edges; x++) | |
6189 | { | |
6190 | fprintf (f, " %-4d - edge(", x); | |
6191 | if (INDEX_EDGE_PRED_BB (elist, x) == ENTRY_BLOCK_PTR) | |
6192 | fprintf (f,"entry,"); | |
6193 | else | |
6194 | fprintf (f,"%d,", INDEX_EDGE_PRED_BB (elist, x)->index); | |
6195 | ||
6196 | if (INDEX_EDGE_SUCC_BB (elist, x) == EXIT_BLOCK_PTR) | |
6197 | fprintf (f,"exit)\n"); | |
6198 | else | |
6199 | fprintf (f,"%d)\n", INDEX_EDGE_SUCC_BB (elist, x)->index); | |
6200 | } | |
6201 | } | |
6202 | ||
6203 | /* This function provides an internal consistancy check of an edge list, | |
6204 | verifying that all edges are present, and that there are no | |
6205 | extra edges. */ | |
6206 | void | |
6207 | verify_edge_list (f, elist) | |
6208 | FILE *f; | |
6209 | struct edge_list *elist; | |
6210 | { | |
6211 | int x, pred, succ, index; | |
410538ea AM |
6212 | edge e; |
6213 | ||
6214 | for (x = 0; x < n_basic_blocks; x++) | |
6215 | { | |
6216 | basic_block bb = BASIC_BLOCK (x); | |
6217 | ||
6218 | for (e = bb->succ; e; e = e->succ_next) | |
6219 | { | |
6220 | pred = e->src->index; | |
6221 | succ = e->dest->index; | |
d675a426 | 6222 | index = EDGE_INDEX (elist, e->src, e->dest); |
410538ea AM |
6223 | if (index == EDGE_INDEX_NO_EDGE) |
6224 | { | |
6225 | fprintf (f, "*p* No index for edge from %d to %d\n",pred, succ); | |
6226 | continue; | |
6227 | } | |
6228 | if (INDEX_EDGE_PRED_BB (elist, index)->index != pred) | |
6229 | fprintf (f, "*p* Pred for index %d should be %d not %d\n", | |
6230 | index, pred, INDEX_EDGE_PRED_BB (elist, index)->index); | |
6231 | if (INDEX_EDGE_SUCC_BB (elist, index)->index != succ) | |
6232 | fprintf (f, "*p* Succ for index %d should be %d not %d\n", | |
6233 | index, succ, INDEX_EDGE_SUCC_BB (elist, index)->index); | |
6234 | } | |
6235 | } | |
6236 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) | |
6237 | { | |
6238 | pred = e->src->index; | |
6239 | succ = e->dest->index; | |
d675a426 | 6240 | index = EDGE_INDEX (elist, e->src, e->dest); |
410538ea AM |
6241 | if (index == EDGE_INDEX_NO_EDGE) |
6242 | { | |
6243 | fprintf (f, "*p* No index for edge from %d to %d\n",pred, succ); | |
6244 | continue; | |
6245 | } | |
6246 | if (INDEX_EDGE_PRED_BB (elist, index)->index != pred) | |
6247 | fprintf (f, "*p* Pred for index %d should be %d not %d\n", | |
6248 | index, pred, INDEX_EDGE_PRED_BB (elist, index)->index); | |
6249 | if (INDEX_EDGE_SUCC_BB (elist, index)->index != succ) | |
6250 | fprintf (f, "*p* Succ for index %d should be %d not %d\n", | |
6251 | index, succ, INDEX_EDGE_SUCC_BB (elist, index)->index); | |
6252 | } | |
6253 | /* We've verified that all the edges are in the list, no lets make sure | |
6254 | there are no spurious edges in the list. */ | |
6255 | ||
6256 | for (pred = 0 ; pred < n_basic_blocks; pred++) | |
6257 | for (succ = 0 ; succ < n_basic_blocks; succ++) | |
6258 | { | |
6259 | basic_block p = BASIC_BLOCK (pred); | |
6260 | basic_block s = BASIC_BLOCK (succ); | |
6261 | ||
6262 | int found_edge = 0; | |
6263 | ||
6264 | for (e = p->succ; e; e = e->succ_next) | |
6265 | if (e->dest == s) | |
6266 | { | |
6267 | found_edge = 1; | |
6268 | break; | |
6269 | } | |
6270 | for (e = s->pred; e; e = e->pred_next) | |
6271 | if (e->src == p) | |
6272 | { | |
6273 | found_edge = 1; | |
6274 | break; | |
6275 | } | |
d675a426 AM |
6276 | if (EDGE_INDEX (elist, BASIC_BLOCK (pred), BASIC_BLOCK (succ)) |
6277 | == EDGE_INDEX_NO_EDGE && found_edge != 0) | |
410538ea AM |
6278 | fprintf (f, "*** Edge (%d, %d) appears to not have an index\n", |
6279 | pred, succ); | |
d675a426 AM |
6280 | if (EDGE_INDEX (elist, BASIC_BLOCK (pred), BASIC_BLOCK (succ)) |
6281 | != EDGE_INDEX_NO_EDGE && found_edge == 0) | |
410538ea | 6282 | fprintf (f, "*** Edge (%d, %d) has index %d, but there is no edge\n", |
d675a426 AM |
6283 | pred, succ, EDGE_INDEX (elist, BASIC_BLOCK (pred), |
6284 | BASIC_BLOCK (succ))); | |
410538ea AM |
6285 | } |
6286 | for (succ = 0 ; succ < n_basic_blocks; succ++) | |
6287 | { | |
6288 | basic_block p = ENTRY_BLOCK_PTR; | |
6289 | basic_block s = BASIC_BLOCK (succ); | |
6290 | ||
6291 | int found_edge = 0; | |
6292 | ||
6293 | for (e = p->succ; e; e = e->succ_next) | |
6294 | if (e->dest == s) | |
6295 | { | |
6296 | found_edge = 1; | |
6297 | break; | |
6298 | } | |
6299 | for (e = s->pred; e; e = e->pred_next) | |
6300 | if (e->src == p) | |
6301 | { | |
6302 | found_edge = 1; | |
6303 | break; | |
6304 | } | |
d675a426 AM |
6305 | if (EDGE_INDEX (elist, ENTRY_BLOCK_PTR, BASIC_BLOCK (succ)) |
6306 | == EDGE_INDEX_NO_EDGE && found_edge != 0) | |
410538ea AM |
6307 | fprintf (f, "*** Edge (entry, %d) appears to not have an index\n", |
6308 | succ); | |
d675a426 AM |
6309 | if (EDGE_INDEX (elist, ENTRY_BLOCK_PTR, BASIC_BLOCK (succ)) |
6310 | != EDGE_INDEX_NO_EDGE && found_edge == 0) | |
410538ea | 6311 | fprintf (f, "*** Edge (entry, %d) has index %d, but no edge exists\n", |
d675a426 AM |
6312 | succ, EDGE_INDEX (elist, ENTRY_BLOCK_PTR, |
6313 | BASIC_BLOCK (succ))); | |
410538ea AM |
6314 | } |
6315 | for (pred = 0 ; pred < n_basic_blocks; pred++) | |
6316 | { | |
6317 | basic_block p = BASIC_BLOCK (pred); | |
6318 | basic_block s = EXIT_BLOCK_PTR; | |
6319 | ||
6320 | int found_edge = 0; | |
6321 | ||
6322 | for (e = p->succ; e; e = e->succ_next) | |
6323 | if (e->dest == s) | |
6324 | { | |
6325 | found_edge = 1; | |
6326 | break; | |
6327 | } | |
6328 | for (e = s->pred; e; e = e->pred_next) | |
6329 | if (e->src == p) | |
6330 | { | |
6331 | found_edge = 1; | |
6332 | break; | |
6333 | } | |
d675a426 AM |
6334 | if (EDGE_INDEX (elist, BASIC_BLOCK (pred), EXIT_BLOCK_PTR) |
6335 | == EDGE_INDEX_NO_EDGE && found_edge != 0) | |
410538ea AM |
6336 | fprintf (f, "*** Edge (%d, exit) appears to not have an index\n", |
6337 | pred); | |
d675a426 AM |
6338 | if (EDGE_INDEX (elist, BASIC_BLOCK (pred), EXIT_BLOCK_PTR) |
6339 | != EDGE_INDEX_NO_EDGE && found_edge == 0) | |
410538ea | 6340 | fprintf (f, "*** Edge (%d, exit) has index %d, but no edge exists\n", |
d675a426 AM |
6341 | pred, EDGE_INDEX (elist, BASIC_BLOCK (pred), |
6342 | EXIT_BLOCK_PTR)); | |
410538ea AM |
6343 | } |
6344 | } | |
6345 | ||
6346 | /* This routine will determine what, if any, edge there is between | |
6347 | a specified predecessor and successor. */ | |
6348 | ||
6349 | int | |
6350 | find_edge_index (edge_list, pred, succ) | |
6351 | struct edge_list *edge_list; | |
d675a426 | 6352 | basic_block pred, succ; |
410538ea AM |
6353 | { |
6354 | int x; | |
6355 | for (x = 0; x < NUM_EDGES (edge_list); x++) | |
6356 | { | |
d675a426 AM |
6357 | if (INDEX_EDGE_PRED_BB (edge_list, x) == pred |
6358 | && INDEX_EDGE_SUCC_BB (edge_list, x) == succ) | |
410538ea AM |
6359 | return x; |
6360 | } | |
6361 | return (EDGE_INDEX_NO_EDGE); | |
6362 | } | |
6363 | ||
87fdf7ff | 6364 | /* This function will remove an edge from the flow graph. */ |
69732dcb | 6365 | void |
87fdf7ff AM |
6366 | remove_edge (e) |
6367 | edge e; | |
6368 | { | |
6369 | edge last_pred = NULL; | |
6370 | edge last_succ = NULL; | |
6371 | edge tmp; | |
6372 | basic_block src, dest; | |
6373 | src = e->src; | |
6374 | dest = e->dest; | |
6375 | for (tmp = src->succ; tmp && tmp != e; tmp = tmp->succ_next) | |
6376 | last_succ = tmp; | |
6377 | ||
6378 | if (!tmp) | |
6379 | abort (); | |
6380 | if (last_succ) | |
6381 | last_succ->succ_next = e->succ_next; | |
6382 | else | |
6383 | src->succ = e->succ_next; | |
6384 | ||
6385 | for (tmp = dest->pred; tmp && tmp != e; tmp = tmp->pred_next) | |
6386 | last_pred = tmp; | |
6387 | ||
6388 | if (!tmp) | |
6389 | abort (); | |
6390 | if (last_pred) | |
6391 | last_pred->pred_next = e->pred_next; | |
6392 | else | |
6393 | dest->pred = e->pred_next; | |
6394 | ||
d3a923ee | 6395 | n_edges--; |
87fdf7ff | 6396 | free (e); |
87fdf7ff AM |
6397 | } |
6398 | ||
6399 | /* This routine will remove any fake successor edges for a basic block. | |
6400 | When the edge is removed, it is also removed from whatever predecessor | |
6401 | list it is in. */ | |
6402 | static void | |
6403 | remove_fake_successors (bb) | |
6404 | basic_block bb; | |
6405 | { | |
6406 | edge e; | |
6407 | for (e = bb->succ; e ; ) | |
6408 | { | |
6409 | edge tmp = e; | |
6410 | e = e->succ_next; | |
6411 | if ((tmp->flags & EDGE_FAKE) == EDGE_FAKE) | |
6412 | remove_edge (tmp); | |
6413 | } | |
6414 | } | |
6415 | ||
6416 | /* This routine will remove all fake edges from the flow graph. If | |
6417 | we remove all fake successors, it will automatically remove all | |
6418 | fake predecessors. */ | |
6419 | void | |
6420 | remove_fake_edges () | |
6421 | { | |
6422 | int x; | |
87fdf7ff AM |
6423 | |
6424 | for (x = 0; x < n_basic_blocks; x++) | |
d3a923ee RH |
6425 | remove_fake_successors (BASIC_BLOCK (x)); |
6426 | ||
c7d04f29 | 6427 | /* We've handled all successors except the entry block's. */ |
87fdf7ff AM |
6428 | remove_fake_successors (ENTRY_BLOCK_PTR); |
6429 | } | |
6430 | ||
6431 | /* This functions will add a fake edge between any block which has no | |
6432 | successors, and the exit block. Some data flow equations require these | |
6433 | edges to exist. */ | |
6434 | void | |
c7d04f29 | 6435 | add_noreturn_fake_exit_edges () |
87fdf7ff AM |
6436 | { |
6437 | int x; | |
6438 | ||
6439 | for (x = 0; x < n_basic_blocks; x++) | |
6440 | if (BASIC_BLOCK (x)->succ == NULL) | |
dbf08f94 | 6441 | make_edge (NULL, BASIC_BLOCK (x), EXIT_BLOCK_PTR, EDGE_FAKE); |
87fdf7ff | 6442 | } |
4dc9341c MH |
6443 | \f |
6444 | /* Dump the list of basic blocks in the bitmap NODES. */ | |
6445 | static void | |
6446 | flow_nodes_print (str, nodes, file) | |
6447 | const char *str; | |
6448 | const sbitmap nodes; | |
6449 | FILE *file; | |
6450 | { | |
6451 | int node; | |
6452 | ||
6453 | fprintf (file, "%s { ", str); | |
6454 | EXECUTE_IF_SET_IN_SBITMAP (nodes, 0, node, {fprintf (file, "%d ", node);}); | |
6455 | fputs ("}\n", file); | |
6456 | } | |
6457 | ||
6458 | ||
6459 | /* Dump the list of exiting edges in the array EDGES. */ | |
6460 | static void | |
6461 | flow_exits_print (str, edges, num_edges, file) | |
6462 | const char *str; | |
6463 | const edge *edges; | |
6464 | int num_edges; | |
6465 | FILE *file; | |
6466 | { | |
6467 | int i; | |
6468 | ||
6469 | fprintf (file, "%s { ", str); | |
6470 | for (i = 0; i < num_edges; i++) | |
6471 | fprintf (file, "%d->%d ", edges[i]->src->index, edges[i]->dest->index); | |
6472 | fputs ("}\n", file); | |
6473 | } | |
6474 | ||
6475 | ||
6476 | /* Dump loop related CFG information. */ | |
6477 | static void | |
6478 | flow_loops_cfg_dump (loops, file) | |
6479 | const struct loops *loops; | |
6480 | FILE *file; | |
6481 | { | |
6482 | int i; | |
6483 | ||
6484 | if (! loops->num || ! file || ! loops->cfg.dom) | |
6485 | return; | |
6486 | ||
6487 | for (i = 0; i < n_basic_blocks; i++) | |
6488 | { | |
6489 | edge succ; | |
6490 | ||
6491 | fprintf (file, ";; %d succs { ", i); | |
6492 | for (succ = BASIC_BLOCK (i)->succ; succ; succ = succ->succ_next) | |
6493 | fprintf (file, "%d ", succ->dest->index); | |
6494 | flow_nodes_print ("} dom", loops->cfg.dom[i], file); | |
6495 | } | |
6496 | ||
6497 | ||
6498 | /* Dump the DFS node order. */ | |
6499 | if (loops->cfg.dfs_order) | |
6500 | { | |
6501 | fputs (";; DFS order: ", file); | |
6502 | for (i = 0; i < n_basic_blocks; i++) | |
6503 | fprintf (file, "%d ", loops->cfg.dfs_order[i]); | |
6504 | fputs ("\n", file); | |
6505 | } | |
6506 | } | |
6507 | ||
6508 | ||
6509 | /* Return non-zero if the nodes of LOOP are a subset of OUTER. */ | |
272df862 | 6510 | static int |
4dc9341c MH |
6511 | flow_loop_nested_p (outer, loop) |
6512 | struct loop *outer; | |
6513 | struct loop *loop; | |
6514 | { | |
6515 | return sbitmap_a_subset_b_p (loop->nodes, outer->nodes); | |
6516 | } | |
6517 | ||
6518 | ||
6519 | /* Dump the loop information specified by LOOPS to the stream FILE. */ | |
6520 | void | |
6521 | flow_loops_dump (loops, file, verbose) | |
6522 | const struct loops *loops; | |
6523 | FILE *file; | |
6524 | int verbose; | |
6525 | { | |
6526 | int i; | |
6527 | int num_loops; | |
6528 | ||
6529 | num_loops = loops->num; | |
6530 | if (! num_loops || ! file) | |
6531 | return; | |
6532 | ||
d6181b1b MH |
6533 | fprintf (file, ";; %d loops found, %d levels\n", |
6534 | num_loops, loops->levels); | |
4dc9341c MH |
6535 | |
6536 | for (i = 0; i < num_loops; i++) | |
6537 | { | |
6538 | struct loop *loop = &loops->array[i]; | |
6539 | ||
d92398a2 | 6540 | fprintf (file, ";; loop %d (%d to %d):\n;; header %d, latch %d, pre-header %d, depth %d, level %d, outer %ld\n", |
4dc9341c MH |
6541 | i, INSN_UID (loop->header->head), INSN_UID (loop->latch->end), |
6542 | loop->header->index, loop->latch->index, | |
6543 | loop->pre_header ? loop->pre_header->index : -1, | |
6544 | loop->depth, loop->level, | |
d92398a2 | 6545 | (long) (loop->outer ? (loop->outer - loops->array) : -1)); |
4dc9341c MH |
6546 | fprintf (file, ";; %d", loop->num_nodes); |
6547 | flow_nodes_print (" nodes", loop->nodes, file); | |
6548 | fprintf (file, ";; %d", loop->num_exits); | |
6549 | flow_exits_print (" exits", loop->exits, loop->num_exits, file); | |
6550 | ||
6551 | if (loop->shared) | |
6552 | { | |
6553 | int j; | |
6554 | ||
6555 | for (j = 0; j < i; j++) | |
6556 | { | |
6557 | struct loop *oloop = &loops->array[j]; | |
6558 | ||
6559 | if (loop->header == oloop->header) | |
6560 | { | |
6561 | int disjoint; | |
6562 | int smaller; | |
6563 | ||
6564 | smaller = loop->num_nodes < oloop->num_nodes; | |
6565 | ||
6566 | /* If the union of LOOP and OLOOP is different than | |
6567 | the larger of LOOP and OLOOP then LOOP and OLOOP | |
6568 | must be disjoint. */ | |
b760c4b1 MH |
6569 | disjoint = ! flow_loop_nested_p (smaller ? loop : oloop, |
6570 | smaller ? oloop : loop); | |
d92398a2 | 6571 | fprintf (file, ";; loop header %d shared by loops %d, %d %s\n", |
4dc9341c MH |
6572 | loop->header->index, i, j, |
6573 | disjoint ? "disjoint" : "nested"); | |
6574 | } | |
6575 | } | |
6576 | } | |
6577 | ||
6578 | if (verbose) | |
6579 | { | |
6580 | /* Print diagnostics to compare our concept of a loop with | |
6581 | what the loop notes say. */ | |
65169dcf JE |
6582 | if (GET_CODE (PREV_INSN (loop->first->head)) != NOTE |
6583 | || NOTE_LINE_NUMBER (PREV_INSN (loop->first->head)) | |
4dc9341c MH |
6584 | != NOTE_INSN_LOOP_BEG) |
6585 | fprintf (file, ";; No NOTE_INSN_LOOP_BEG at %d\n", | |
65169dcf JE |
6586 | INSN_UID (PREV_INSN (loop->first->head))); |
6587 | if (GET_CODE (NEXT_INSN (loop->last->end)) != NOTE | |
6588 | || NOTE_LINE_NUMBER (NEXT_INSN (loop->last->end)) | |
4dc9341c MH |
6589 | != NOTE_INSN_LOOP_END) |
6590 | fprintf (file, ";; No NOTE_INSN_LOOP_END at %d\n", | |
65169dcf | 6591 | INSN_UID (NEXT_INSN (loop->last->end))); |
4dc9341c MH |
6592 | } |
6593 | } | |
6594 | ||
6595 | if (verbose) | |
6596 | flow_loops_cfg_dump (loops, file); | |
6597 | } | |
6598 | ||
6599 | ||
6600 | /* Free all the memory allocated for LOOPS. */ | |
6601 | void | |
6602 | flow_loops_free (loops) | |
6603 | struct loops *loops; | |
6604 | { | |
6605 | if (loops->array) | |
6606 | { | |
6607 | int i; | |
6608 | ||
6609 | if (! loops->num) | |
6610 | abort (); | |
6611 | ||
6612 | /* Free the loop descriptors. */ | |
6613 | for (i = 0; i < loops->num; i++) | |
6614 | { | |
6615 | struct loop *loop = &loops->array[i]; | |
6616 | ||
6617 | if (loop->nodes) | |
6618 | sbitmap_free (loop->nodes); | |
6619 | if (loop->exits) | |
6620 | free (loop->exits); | |
6621 | } | |
6622 | free (loops->array); | |
6623 | loops->array = NULL; | |
6624 | ||
6625 | if (loops->cfg.dom) | |
6626 | sbitmap_vector_free (loops->cfg.dom); | |
6627 | if (loops->cfg.dfs_order) | |
6628 | free (loops->cfg.dfs_order); | |
6629 | ||
6630 | sbitmap_free (loops->shared_headers); | |
6631 | } | |
6632 | } | |
6633 | ||
6634 | ||
6635 | /* Find the exits from the loop using the bitmap of loop nodes NODES | |
6636 | and store in EXITS array. Return the number of exits from the | |
6637 | loop. */ | |
6638 | static int | |
6639 | flow_loop_exits_find (nodes, exits) | |
6640 | const sbitmap nodes; | |
6641 | edge **exits; | |
6642 | { | |
6643 | edge e; | |
6644 | int node; | |
6645 | int num_exits; | |
6646 | ||
6647 | *exits = NULL; | |
6648 | ||
6649 | /* Check all nodes within the loop to see if there are any | |
6650 | successors not in the loop. Note that a node may have multiple | |
6651 | exiting edges. */ | |
6652 | num_exits = 0; | |
6653 | EXECUTE_IF_SET_IN_SBITMAP (nodes, 0, node, { | |
6654 | for (e = BASIC_BLOCK (node)->succ; e; e = e->succ_next) | |
6655 | { | |
6656 | basic_block dest = e->dest; | |
6657 | ||
6658 | if (dest == EXIT_BLOCK_PTR || ! TEST_BIT (nodes, dest->index)) | |
6659 | num_exits++; | |
6660 | } | |
6661 | }); | |
6662 | ||
6663 | if (! num_exits) | |
6664 | return 0; | |
6665 | ||
6666 | *exits = (edge *) xmalloc (num_exits * sizeof (edge *)); | |
6667 | ||
6668 | /* Store all exiting edges into an array. */ | |
6669 | num_exits = 0; | |
6670 | EXECUTE_IF_SET_IN_SBITMAP (nodes, 0, node, { | |
6671 | for (e = BASIC_BLOCK (node)->succ; e; e = e->succ_next) | |
6672 | { | |
6673 | basic_block dest = e->dest; | |
6674 | ||
6675 | if (dest == EXIT_BLOCK_PTR || ! TEST_BIT (nodes, dest->index)) | |
6676 | (*exits)[num_exits++] = e; | |
6677 | } | |
6678 | }); | |
6679 | ||
6680 | return num_exits; | |
6681 | } | |
6682 | ||
6683 | ||
6684 | /* Find the nodes contained within the loop with header HEADER and | |
6685 | latch LATCH and store in NODES. Return the number of nodes within | |
6686 | the loop. */ | |
6687 | static int | |
6688 | flow_loop_nodes_find (header, latch, nodes) | |
6689 | basic_block header; | |
6690 | basic_block latch; | |
6691 | sbitmap nodes; | |
6692 | { | |
6693 | basic_block *stack; | |
6694 | int sp; | |
6695 | int num_nodes = 0; | |
6696 | ||
6697 | stack = (basic_block *) xmalloc (n_basic_blocks * sizeof (basic_block)); | |
6698 | sp = 0; | |
6699 | ||
6700 | /* Start with only the loop header in the set of loop nodes. */ | |
6701 | sbitmap_zero (nodes); | |
6702 | SET_BIT (nodes, header->index); | |
6703 | num_nodes++; | |
ce4bbac7 | 6704 | header->loop_depth++; |
4dc9341c MH |
6705 | |
6706 | /* Push the loop latch on to the stack. */ | |
6707 | if (! TEST_BIT (nodes, latch->index)) | |
6708 | { | |
6709 | SET_BIT (nodes, latch->index); | |
ce4bbac7 | 6710 | latch->loop_depth++; |
4dc9341c MH |
6711 | num_nodes++; |
6712 | stack[sp++] = latch; | |
6713 | } | |
6714 | ||
6715 | while (sp) | |
6716 | { | |
6717 | basic_block node; | |
6718 | edge e; | |
6719 | ||
6720 | node = stack[--sp]; | |
6721 | for (e = node->pred; e; e = e->pred_next) | |
6722 | { | |
6723 | basic_block ancestor = e->src; | |
6724 | ||
6725 | /* If each ancestor not marked as part of loop, add to set of | |
6726 | loop nodes and push on to stack. */ | |
6727 | if (ancestor != ENTRY_BLOCK_PTR | |
6728 | && ! TEST_BIT (nodes, ancestor->index)) | |
6729 | { | |
6730 | SET_BIT (nodes, ancestor->index); | |
ce4bbac7 | 6731 | ancestor->loop_depth++; |
4dc9341c MH |
6732 | num_nodes++; |
6733 | stack[sp++] = ancestor; | |
6734 | } | |
6735 | } | |
6736 | } | |
6737 | free (stack); | |
6738 | return num_nodes; | |
6739 | } | |
6740 | ||
6741 | ||
6742 | /* Compute the depth first search order and store in the array | |
6743 | DFS_ORDER, marking the nodes visited in VISITED. Returns the | |
6744 | number of nodes visited. */ | |
6745 | static int | |
6746 | flow_depth_first_order_compute (dfs_order) | |
6747 | int *dfs_order; | |
6748 | { | |
6749 | edge e; | |
6750 | edge *stack; | |
6751 | int sp; | |
6752 | int dfsnum = 0; | |
6753 | sbitmap visited; | |
6754 | ||
6755 | /* Allocate stack for back-tracking up CFG. */ | |
6756 | stack = (edge *) xmalloc (n_basic_blocks * sizeof (edge)); | |
6757 | sp = 0; | |
6758 | ||
6759 | /* Allocate bitmap to track nodes that have been visited. */ | |
6760 | visited = sbitmap_alloc (n_basic_blocks); | |
6761 | ||
6762 | /* None of the nodes in the CFG have been visited yet. */ | |
6763 | sbitmap_zero (visited); | |
6764 | ||
6765 | /* Start with the first successor edge from the entry block. */ | |
6766 | e = ENTRY_BLOCK_PTR->succ; | |
6767 | while (e) | |
6768 | { | |
6769 | basic_block src = e->src; | |
6770 | basic_block dest = e->dest; | |
6771 | ||
6772 | /* Mark that we have visited this node. */ | |
6773 | if (src != ENTRY_BLOCK_PTR) | |
6774 | SET_BIT (visited, src->index); | |
6775 | ||
6776 | /* If this node has not been visited before, push the current | |
6777 | edge on to the stack and proceed with the first successor | |
6778 | edge of this node. */ | |
6779 | if (dest != EXIT_BLOCK_PTR && ! TEST_BIT (visited, dest->index) | |
6780 | && dest->succ) | |
6781 | { | |
6782 | stack[sp++] = e; | |
6783 | e = dest->succ; | |
6784 | } | |
6785 | else | |
6786 | { | |
6787 | if (dest != EXIT_BLOCK_PTR && ! TEST_BIT (visited, dest->index) | |
6788 | && ! dest->succ) | |
6789 | { | |
6790 | /* DEST has no successors (for example, a non-returning | |
6791 | function is called) so do not push the current edge | |
6792 | but carry on with its next successor. */ | |
6793 | dfs_order[dest->index] = n_basic_blocks - ++dfsnum; | |
6794 | SET_BIT (visited, dest->index); | |
6795 | } | |
6796 | ||
6797 | while (! e->succ_next && src != ENTRY_BLOCK_PTR) | |
6798 | { | |
6799 | dfs_order[src->index] = n_basic_blocks - ++dfsnum; | |
6800 | ||
6801 | /* Pop edge off stack. */ | |
6802 | e = stack[--sp]; | |
6803 | src = e->src; | |
6804 | } | |
6805 | e = e->succ_next; | |
6806 | } | |
6807 | } | |
6808 | free (stack); | |
6809 | sbitmap_free (visited); | |
6810 | ||
6811 | /* The number of nodes visited should not be greater than | |
6812 | n_basic_blocks. */ | |
6813 | if (dfsnum > n_basic_blocks) | |
6814 | abort (); | |
6815 | ||
6816 | /* There are some nodes left in the CFG that are unreachable. */ | |
6817 | if (dfsnum < n_basic_blocks) | |
6818 | abort (); | |
6819 | return dfsnum; | |
6820 | } | |
6821 | ||
6822 | ||
6823 | /* Return the block for the pre-header of the loop with header | |
6824 | HEADER where DOM specifies the dominator information. Return NULL if | |
6825 | there is no pre-header. */ | |
6826 | static basic_block | |
6827 | flow_loop_pre_header_find (header, dom) | |
6828 | basic_block header; | |
6829 | const sbitmap *dom; | |
6830 | { | |
6831 | basic_block pre_header; | |
6832 | edge e; | |
6833 | ||
6834 | /* If block p is a predecessor of the header and is the only block | |
6835 | that the header does not dominate, then it is the pre-header. */ | |
6836 | pre_header = NULL; | |
6837 | for (e = header->pred; e; e = e->pred_next) | |
6838 | { | |
6839 | basic_block node = e->src; | |
6840 | ||
6841 | if (node != ENTRY_BLOCK_PTR | |
6842 | && ! TEST_BIT (dom[node->index], header->index)) | |
6843 | { | |
6844 | if (pre_header == NULL) | |
6845 | pre_header = node; | |
6846 | else | |
6847 | { | |
6848 | /* There are multiple edges into the header from outside | |
6849 | the loop so there is no pre-header block. */ | |
6850 | pre_header = NULL; | |
6851 | break; | |
6852 | } | |
6853 | } | |
6854 | } | |
6855 | return pre_header; | |
6856 | } | |
6857 | ||
6858 | ||
3abd3239 MH |
6859 | /* Add LOOP to the loop hierarchy tree where PREVLOOP was the loop |
6860 | previously added. The insertion algorithm assumes that the loops | |
6861 | are added in the order found by a depth first search of the CFG. */ | |
4dc9341c | 6862 | static void |
3abd3239 MH |
6863 | flow_loop_tree_node_add (prevloop, loop) |
6864 | struct loop *prevloop; | |
4dc9341c MH |
6865 | struct loop *loop; |
6866 | { | |
4dc9341c | 6867 | |
3abd3239 MH |
6868 | if (flow_loop_nested_p (prevloop, loop)) |
6869 | { | |
6870 | prevloop->inner = loop; | |
6871 | loop->outer = prevloop; | |
6872 | return; | |
6873 | } | |
4dc9341c | 6874 | |
3abd3239 | 6875 | while (prevloop->outer) |
4dc9341c | 6876 | { |
3abd3239 | 6877 | if (flow_loop_nested_p (prevloop->outer, loop)) |
4dc9341c | 6878 | { |
3abd3239 MH |
6879 | prevloop->next = loop; |
6880 | loop->outer = prevloop->outer; | |
4dc9341c MH |
6881 | return; |
6882 | } | |
3abd3239 | 6883 | prevloop = prevloop->outer; |
4dc9341c | 6884 | } |
3abd3239 MH |
6885 | |
6886 | prevloop->next = loop; | |
6887 | loop->outer = NULL; | |
4dc9341c MH |
6888 | } |
6889 | ||
6890 | ||
6891 | /* Build the loop hierarchy tree for LOOPS. */ | |
6892 | static void | |
6893 | flow_loops_tree_build (loops) | |
6894 | struct loops *loops; | |
6895 | { | |
6896 | int i; | |
6897 | int num_loops; | |
6898 | ||
6899 | num_loops = loops->num; | |
6900 | if (! num_loops) | |
6901 | return; | |
6902 | ||
6903 | /* Root the loop hierarchy tree with the first loop found. | |
6904 | Since we used a depth first search this should be the | |
6905 | outermost loop. */ | |
6906 | loops->tree = &loops->array[0]; | |
6907 | loops->tree->outer = loops->tree->inner = loops->tree->next = NULL; | |
6908 | ||
6909 | /* Add the remaining loops to the tree. */ | |
6910 | for (i = 1; i < num_loops; i++) | |
3abd3239 | 6911 | flow_loop_tree_node_add (&loops->array[i - 1], &loops->array[i]); |
4dc9341c MH |
6912 | } |
6913 | ||
6914 | ||
6915 | /* Helper function to compute loop nesting depth and enclosed loop level | |
6916 | for the natural loop specified by LOOP at the loop depth DEPTH. | |
6917 | Returns the loop level. */ | |
6918 | static int | |
6919 | flow_loop_level_compute (loop, depth) | |
6920 | struct loop *loop; | |
6921 | int depth; | |
6922 | { | |
6923 | struct loop *inner; | |
d6181b1b | 6924 | int level = 1; |
4dc9341c MH |
6925 | |
6926 | if (! loop) | |
6927 | return 0; | |
6928 | ||
6929 | /* Traverse loop tree assigning depth and computing level as the | |
6930 | maximum level of all the inner loops of this loop. The loop | |
6931 | level is equivalent to the height of the loop in the loop tree | |
d6181b1b MH |
6932 | and corresponds to the number of enclosed loop levels (including |
6933 | itself). */ | |
4dc9341c MH |
6934 | for (inner = loop->inner; inner; inner = inner->next) |
6935 | { | |
6936 | int ilevel; | |
6937 | ||
6938 | ilevel = flow_loop_level_compute (inner, depth + 1) + 1; | |
6939 | ||
6940 | if (ilevel > level) | |
6941 | level = ilevel; | |
6942 | } | |
6943 | loop->level = level; | |
6944 | loop->depth = depth; | |
6945 | return level; | |
6946 | } | |
6947 | ||
6948 | ||
6949 | /* Compute the loop nesting depth and enclosed loop level for the loop | |
6950 | hierarchy tree specfied by LOOPS. Return the maximum enclosed loop | |
6951 | level. */ | |
d4b60170 | 6952 | |
d6181b1b | 6953 | static int |
4dc9341c MH |
6954 | flow_loops_level_compute (loops) |
6955 | struct loops *loops; | |
6956 | { | |
d6181b1b MH |
6957 | struct loop *loop; |
6958 | int level; | |
6959 | int levels = 0; | |
6960 | ||
6961 | /* Traverse all the outer level loops. */ | |
6962 | for (loop = loops->tree; loop; loop = loop->next) | |
6963 | { | |
6964 | level = flow_loop_level_compute (loop, 1); | |
6965 | if (level > levels) | |
6966 | levels = level; | |
6967 | } | |
6968 | return levels; | |
4dc9341c MH |
6969 | } |
6970 | ||
6971 | ||
ce4bbac7 JH |
6972 | /* Find all the natural loops in the function and save in LOOPS structure |
6973 | and recalculate loop_depth information in basic block structures. | |
4dc9341c | 6974 | Return the number of natural loops found. */ |
d4b60170 | 6975 | |
4dc9341c MH |
6976 | int |
6977 | flow_loops_find (loops) | |
6978 | struct loops *loops; | |
6979 | { | |
6980 | int i; | |
6981 | int b; | |
6982 | int num_loops; | |
6983 | edge e; | |
6984 | sbitmap headers; | |
6985 | sbitmap *dom; | |
6986 | int *dfs_order; | |
6987 | ||
6988 | loops->num = 0; | |
6989 | loops->array = NULL; | |
6990 | loops->tree = NULL; | |
6991 | dfs_order = NULL; | |
6992 | ||
6993 | /* Taking care of this degenerate case makes the rest of | |
6994 | this code simpler. */ | |
6995 | if (n_basic_blocks == 0) | |
6996 | return 0; | |
6997 | ||
6998 | /* Compute the dominators. */ | |
6999 | dom = sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks); | |
7000 | compute_flow_dominators (dom, NULL); | |
7001 | ||
7002 | /* Count the number of loop edges (back edges). This should be the | |
ce4bbac7 JH |
7003 | same as the number of natural loops. Also clear the loop_depth |
7004 | and as we work from inner->outer in a loop nest we call | |
7005 | find_loop_nodes_find which will increment loop_depth for nodes | |
7006 | within the current loop, which happens to enclose inner loops. */ | |
7007 | ||
4dc9341c MH |
7008 | num_loops = 0; |
7009 | for (b = 0; b < n_basic_blocks; b++) | |
7010 | { | |
9b15c17f | 7011 | BASIC_BLOCK (b)->loop_depth = 0; |
4dc9341c MH |
7012 | for (e = BASIC_BLOCK (b)->pred; e; e = e->pred_next) |
7013 | { | |
7014 | basic_block latch = e->src; | |
7015 | ||
7016 | /* Look for back edges where a predecessor is dominated | |
7017 | by this block. A natural loop has a single entry | |
7018 | node (header) that dominates all the nodes in the | |
7019 | loop. It also has single back edge to the header | |
7020 | from a latch node. Note that multiple natural loops | |
7021 | may share the same header. */ | |
7022 | if (latch != ENTRY_BLOCK_PTR && TEST_BIT (dom[latch->index], b)) | |
7023 | num_loops++; | |
7024 | } | |
7025 | } | |
7026 | ||
7027 | if (num_loops) | |
7028 | { | |
7029 | /* Compute depth first search order of the CFG so that outer | |
7030 | natural loops will be found before inner natural loops. */ | |
7031 | dfs_order = (int *) xmalloc (n_basic_blocks * sizeof (int)); | |
7032 | flow_depth_first_order_compute (dfs_order); | |
7033 | ||
7034 | /* Allocate loop structures. */ | |
d4b60170 RK |
7035 | loops->array |
7036 | = (struct loop *) xcalloc (num_loops, sizeof (struct loop)); | |
4dc9341c MH |
7037 | |
7038 | headers = sbitmap_alloc (n_basic_blocks); | |
7039 | sbitmap_zero (headers); | |
7040 | ||
7041 | loops->shared_headers = sbitmap_alloc (n_basic_blocks); | |
7042 | sbitmap_zero (loops->shared_headers); | |
7043 | ||
7044 | /* Find and record information about all the natural loops | |
7045 | in the CFG. */ | |
7046 | num_loops = 0; | |
7047 | for (b = 0; b < n_basic_blocks; b++) | |
7048 | { | |
7049 | basic_block header; | |
7050 | ||
7051 | /* Search the nodes of the CFG in DFS order that we can find | |
7052 | outer loops first. */ | |
7053 | header = BASIC_BLOCK (dfs_order[b]); | |
7054 | ||
7055 | /* Look for all the possible latch blocks for this header. */ | |
7056 | for (e = header->pred; e; e = e->pred_next) | |
7057 | { | |
7058 | basic_block latch = e->src; | |
7059 | ||
7060 | /* Look for back edges where a predecessor is dominated | |
7061 | by this block. A natural loop has a single entry | |
7062 | node (header) that dominates all the nodes in the | |
7063 | loop. It also has single back edge to the header | |
7064 | from a latch node. Note that multiple natural loops | |
7065 | may share the same header. */ | |
7066 | if (latch != ENTRY_BLOCK_PTR | |
7067 | && TEST_BIT (dom[latch->index], header->index)) | |
7068 | { | |
7069 | struct loop *loop; | |
7070 | ||
7071 | loop = loops->array + num_loops; | |
7072 | ||
7073 | loop->header = header; | |
7074 | loop->latch = latch; | |
7075 | ||
7076 | /* Keep track of blocks that are loop headers so | |
7077 | that we can tell which loops should be merged. */ | |
7078 | if (TEST_BIT (headers, header->index)) | |
7079 | SET_BIT (loops->shared_headers, header->index); | |
7080 | SET_BIT (headers, header->index); | |
7081 | ||
7082 | /* Find nodes contained within the loop. */ | |
7083 | loop->nodes = sbitmap_alloc (n_basic_blocks); | |
d4b60170 RK |
7084 | loop->num_nodes |
7085 | = flow_loop_nodes_find (header, latch, loop->nodes); | |
65169dcf JE |
7086 | |
7087 | /* Compute first and last blocks within the loop. | |
7088 | These are often the same as the loop header and | |
7089 | loop latch respectively, but this is not always | |
7090 | the case. */ | |
7091 | loop->first | |
7092 | = BASIC_BLOCK (sbitmap_first_set_bit (loop->nodes)); | |
7093 | loop->last | |
7094 | = BASIC_BLOCK (sbitmap_last_set_bit (loop->nodes)); | |
7095 | ||
4dc9341c MH |
7096 | /* Find edges which exit the loop. Note that a node |
7097 | may have several exit edges. */ | |
7098 | loop->num_exits | |
7099 | = flow_loop_exits_find (loop->nodes, &loop->exits); | |
7100 | ||
7101 | /* Look to see if the loop has a pre-header node. */ | |
7102 | loop->pre_header | |
7103 | = flow_loop_pre_header_find (header, dom); | |
7104 | ||
7105 | num_loops++; | |
7106 | } | |
7107 | } | |
7108 | } | |
7109 | ||
7110 | /* Natural loops with shared headers may either be disjoint or | |
7111 | nested. Disjoint loops with shared headers cannot be inner | |
7112 | loops and should be merged. For now just mark loops that share | |
7113 | headers. */ | |
7114 | for (i = 0; i < num_loops; i++) | |
7115 | if (TEST_BIT (loops->shared_headers, loops->array[i].header->index)) | |
7116 | loops->array[i].shared = 1; | |
7117 | ||
7118 | sbitmap_free (headers); | |
7119 | } | |
7120 | ||
7121 | loops->num = num_loops; | |
7122 | ||
7123 | /* Save CFG derived information to avoid recomputing it. */ | |
7124 | loops->cfg.dom = dom; | |
7125 | loops->cfg.dfs_order = dfs_order; | |
7126 | ||
7127 | /* Build the loop hierarchy tree. */ | |
7128 | flow_loops_tree_build (loops); | |
7129 | ||
7130 | /* Assign the loop nesting depth and enclosed loop level for each | |
7131 | loop. */ | |
d6181b1b | 7132 | loops->levels = flow_loops_level_compute (loops); |
4dc9341c MH |
7133 | |
7134 | return num_loops; | |
7135 | } | |
7136 | ||
7137 | ||
7138 | /* Return non-zero if edge E enters header of LOOP from outside of LOOP. */ | |
7139 | int | |
7140 | flow_loop_outside_edge_p (loop, e) | |
7141 | const struct loop *loop; | |
7142 | edge e; | |
7143 | { | |
7144 | if (e->dest != loop->header) | |
7145 | abort (); | |
7146 | return (e->src == ENTRY_BLOCK_PTR) | |
7147 | || ! TEST_BIT (loop->nodes, e->src->index); | |
7148 | } | |
11bdd2ae SC |
7149 | |
7150 | ||
d9d4fb43 AS |
7151 | /* Clear LOG_LINKS fields of insns in a chain. */ |
7152 | void | |
7153 | clear_log_links (insns) | |
7154 | rtx insns; | |
7155 | { | |
7156 | rtx i; | |
7157 | for (i = insns; i; i = NEXT_INSN (i)) | |
7158 | if (GET_RTX_CLASS (GET_CODE (i)) == 'i') | |
7159 | LOG_LINKS (i) = 0; | |
7160 | } |