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9ec6d7ab | 1 | /* If-conversion support. |
7f646877 | 2 | Copyright (C) 2000, 2001 Free Software Foundation, Inc. |
9ec6d7ab RH |
3 | |
4 | This file is part of GNU CC. | |
5 | ||
6 | GNU CC is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GNU CC is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GNU CC; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, 59 Temple Place - Suite 330, | |
19 | Boston, MA 02111-1307, USA. */ | |
20 | ||
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | ||
24 | #include "rtl.h" | |
25 | #include "regs.h" | |
26 | #include "function.h" | |
27 | #include "flags.h" | |
28 | #include "insn-config.h" | |
29 | #include "recog.h" | |
efc9bd41 | 30 | #include "hard-reg-set.h" |
9ec6d7ab RH |
31 | #include "basic-block.h" |
32 | #include "expr.h" | |
05cc23e8 | 33 | #include "real.h" |
9ec6d7ab | 34 | #include "output.h" |
d6684bc8 | 35 | #include "toplev.h" |
9ec6d7ab RH |
36 | #include "tm_p.h" |
37 | ||
38 | ||
39 | #ifndef HAVE_conditional_execution | |
40 | #define HAVE_conditional_execution 0 | |
41 | #endif | |
42 | #ifndef HAVE_conditional_move | |
43 | #define HAVE_conditional_move 0 | |
44 | #endif | |
45 | #ifndef HAVE_incscc | |
46 | #define HAVE_incscc 0 | |
47 | #endif | |
48 | #ifndef HAVE_decscc | |
49 | #define HAVE_decscc 0 | |
50 | #endif | |
999c0669 RH |
51 | #ifndef HAVE_trap |
52 | #define HAVE_trap 0 | |
53 | #endif | |
54 | #ifndef HAVE_conditional_trap | |
55 | #define HAVE_conditional_trap 0 | |
56 | #endif | |
9ec6d7ab RH |
57 | |
58 | #ifndef MAX_CONDITIONAL_EXECUTE | |
59 | #define MAX_CONDITIONAL_EXECUTE (BRANCH_COST + 1) | |
60 | #endif | |
61 | ||
9ec6d7ab RH |
62 | #define NULL_EDGE ((struct edge_def *)NULL) |
63 | #define NULL_BLOCK ((struct basic_block_def *)NULL) | |
64 | ||
65 | /* # of IF-THEN or IF-THEN-ELSE blocks we looked at */ | |
66 | static int num_possible_if_blocks; | |
67 | ||
68 | /* # of IF-THEN or IF-THEN-ELSE blocks were converted to conditional | |
69 | execution. */ | |
70 | static int num_updated_if_blocks; | |
71 | ||
72 | /* # of basic blocks that were removed. */ | |
73 | static int num_removed_blocks; | |
74 | ||
e16d045d RH |
75 | /* True if life data ok at present. */ |
76 | static bool life_data_ok; | |
77 | ||
9ec6d7ab RH |
78 | /* The post-dominator relation on the original block numbers. */ |
79 | static sbitmap *post_dominators; | |
80 | ||
81 | /* Forward references. */ | |
82 | static int count_bb_insns PARAMS ((basic_block)); | |
83 | static rtx first_active_insn PARAMS ((basic_block)); | |
84 | static int last_active_insn_p PARAMS ((basic_block, rtx)); | |
4e4017cb | 85 | static int seq_contains_jump PARAMS ((rtx)); |
9ec6d7ab | 86 | |
2ff00dd4 | 87 | static int cond_exec_process_insns PARAMS ((rtx, rtx, rtx, rtx, int)); |
9ec6d7ab RH |
88 | static rtx cond_exec_get_condition PARAMS ((rtx)); |
89 | static int cond_exec_process_if_block PARAMS ((basic_block, basic_block, | |
90 | basic_block, basic_block)); | |
91 | ||
92 | static rtx noce_get_condition PARAMS ((rtx, rtx *)); | |
05cc23e8 | 93 | static int noce_operand_ok PARAMS ((rtx)); |
9ec6d7ab RH |
94 | static int noce_process_if_block PARAMS ((basic_block, basic_block, |
95 | basic_block, basic_block)); | |
96 | ||
97 | static int process_if_block PARAMS ((basic_block, basic_block, | |
98 | basic_block, basic_block)); | |
99 | static void merge_if_block PARAMS ((basic_block, basic_block, | |
100 | basic_block, basic_block)); | |
101 | ||
102 | static int find_if_header PARAMS ((basic_block)); | |
103 | static int find_if_block PARAMS ((basic_block, edge, edge)); | |
104 | static int find_if_case_1 PARAMS ((basic_block, edge, edge)); | |
105 | static int find_if_case_2 PARAMS ((basic_block, edge, edge)); | |
999c0669 | 106 | static int find_cond_trap PARAMS ((basic_block, edge, edge)); |
9ec6d7ab RH |
107 | static int find_memory PARAMS ((rtx *, void *)); |
108 | static int dead_or_predicable PARAMS ((basic_block, basic_block, | |
6b24c259 | 109 | basic_block, basic_block, int)); |
32ff70d2 | 110 | static void noce_emit_move_insn PARAMS ((rtx, rtx)); |
9ec6d7ab RH |
111 | \f |
112 | /* Abuse the basic_block AUX field to store the original block index, | |
113 | as well as a flag indicating that the block should be rescaned for | |
114 | life analysis. */ | |
115 | ||
116 | #define SET_ORIG_INDEX(BB,I) ((BB)->aux = (void *)((size_t)(I) << 1)) | |
117 | #define ORIG_INDEX(BB) ((size_t)(BB)->aux >> 1) | |
118 | #define SET_UPDATE_LIFE(BB) ((BB)->aux = (void *)((size_t)(BB)->aux | 1)) | |
119 | #define UPDATE_LIFE(BB) ((size_t)(BB)->aux & 1) | |
120 | ||
121 | \f | |
122 | /* Count the number of non-jump active insns in BB. */ | |
123 | ||
124 | static int | |
125 | count_bb_insns (bb) | |
126 | basic_block bb; | |
127 | { | |
128 | int count = 0; | |
129 | rtx insn = bb->head; | |
130 | ||
131 | while (1) | |
132 | { | |
133 | if (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == INSN) | |
134 | count++; | |
135 | ||
136 | if (insn == bb->end) | |
137 | break; | |
138 | insn = NEXT_INSN (insn); | |
139 | } | |
140 | ||
141 | return count; | |
142 | } | |
143 | ||
144 | /* Return the first non-jump active insn in the basic block. */ | |
145 | ||
146 | static rtx | |
147 | first_active_insn (bb) | |
148 | basic_block bb; | |
149 | { | |
150 | rtx insn = bb->head; | |
151 | ||
152 | if (GET_CODE (insn) == CODE_LABEL) | |
153 | { | |
154 | if (insn == bb->end) | |
155 | return NULL_RTX; | |
156 | insn = NEXT_INSN (insn); | |
157 | } | |
158 | ||
159 | while (GET_CODE (insn) == NOTE) | |
160 | { | |
161 | if (insn == bb->end) | |
162 | return NULL_RTX; | |
163 | insn = NEXT_INSN (insn); | |
164 | } | |
165 | ||
166 | if (GET_CODE (insn) == JUMP_INSN) | |
167 | return NULL_RTX; | |
168 | ||
169 | return insn; | |
170 | } | |
171 | ||
172 | /* Return true if INSN is the last active non-jump insn in BB. */ | |
173 | ||
174 | static int | |
175 | last_active_insn_p (bb, insn) | |
176 | basic_block bb; | |
177 | rtx insn; | |
178 | { | |
179 | do | |
180 | { | |
181 | if (insn == bb->end) | |
182 | return TRUE; | |
183 | insn = NEXT_INSN (insn); | |
184 | } | |
185 | while (GET_CODE (insn) == NOTE); | |
186 | ||
187 | return GET_CODE (insn) == JUMP_INSN; | |
188 | } | |
4e4017cb RH |
189 | |
190 | /* It is possible, especially when having dealt with multi-word | |
191 | arithmetic, for the expanders to have emitted jumps. Search | |
192 | through the sequence and return TRUE if a jump exists so that | |
193 | we can abort the conversion. */ | |
194 | ||
195 | static int | |
196 | seq_contains_jump (insn) | |
197 | rtx insn; | |
198 | { | |
199 | while (insn) | |
200 | { | |
201 | if (GET_CODE (insn) == JUMP_INSN) | |
202 | return 1; | |
203 | insn = NEXT_INSN (insn); | |
204 | } | |
205 | return 0; | |
206 | } | |
9ec6d7ab RH |
207 | \f |
208 | /* Go through a bunch of insns, converting them to conditional | |
209 | execution format if possible. Return TRUE if all of the non-note | |
210 | insns were processed. */ | |
211 | ||
212 | static int | |
2ff00dd4 | 213 | cond_exec_process_insns (start, end, test, prob_val, mod_ok) |
9ec6d7ab RH |
214 | rtx start; /* first insn to look at */ |
215 | rtx end; /* last insn to look at */ | |
216 | rtx test; /* conditional execution test */ | |
2ff00dd4 | 217 | rtx prob_val; /* probability of branch taken. */ |
9ec6d7ab RH |
218 | int mod_ok; /* true if modifications ok last insn. */ |
219 | { | |
220 | int must_be_last = FALSE; | |
221 | rtx insn; | |
90280148 | 222 | rtx pattern; |
9ec6d7ab RH |
223 | |
224 | for (insn = start; ; insn = NEXT_INSN (insn)) | |
225 | { | |
226 | if (GET_CODE (insn) == NOTE) | |
227 | goto insn_done; | |
228 | ||
229 | if (GET_CODE (insn) != INSN && GET_CODE (insn) != CALL_INSN) | |
230 | abort (); | |
231 | ||
e0fa93b3 RH |
232 | /* Remove USE insns that get in the way. */ |
233 | if (reload_completed && GET_CODE (PATTERN (insn)) == USE) | |
7f9d9ea1 RH |
234 | { |
235 | /* ??? Ug. Actually unlinking the thing is problematic, | |
236 | given what we'd have to coordinate with our callers. */ | |
237 | PUT_CODE (insn, NOTE); | |
238 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
239 | NOTE_SOURCE_FILE (insn) = 0; | |
240 | goto insn_done; | |
241 | } | |
242 | ||
9ec6d7ab RH |
243 | /* Last insn wasn't last? */ |
244 | if (must_be_last) | |
245 | return FALSE; | |
246 | ||
247 | if (modified_in_p (test, insn)) | |
248 | { | |
249 | if (!mod_ok) | |
250 | return FALSE; | |
251 | must_be_last = TRUE; | |
252 | } | |
253 | ||
254 | /* Now build the conditional form of the instruction. */ | |
90280148 MM |
255 | pattern = PATTERN (insn); |
256 | ||
257 | /* If the machine needs to modify the insn being conditionally executed, | |
258 | say for example to force a constant integer operand into a temp | |
259 | register, do so here. */ | |
260 | #ifdef IFCVT_MODIFY_INSN | |
261 | IFCVT_MODIFY_INSN (pattern, insn); | |
262 | if (! pattern) | |
263 | return FALSE; | |
264 | #endif | |
265 | ||
9ec6d7ab RH |
266 | validate_change (insn, &PATTERN (insn), |
267 | gen_rtx_COND_EXEC (VOIDmode, copy_rtx (test), | |
90280148 | 268 | pattern), 1); |
9ec6d7ab | 269 | |
2ff00dd4 RH |
270 | if (GET_CODE (insn) == CALL_INSN && prob_val) |
271 | validate_change (insn, ®_NOTES (insn), | |
272 | alloc_EXPR_LIST (REG_BR_PROB, prob_val, | |
273 | REG_NOTES (insn)), 1); | |
274 | ||
9ec6d7ab RH |
275 | insn_done: |
276 | if (insn == end) | |
277 | break; | |
278 | } | |
279 | ||
280 | return TRUE; | |
281 | } | |
282 | ||
283 | /* Return the condition for a jump. Do not do any special processing. */ | |
284 | ||
285 | static rtx | |
286 | cond_exec_get_condition (jump) | |
287 | rtx jump; | |
288 | { | |
289 | rtx test_if, cond; | |
290 | ||
7f1c097d | 291 | if (any_condjump_p (jump)) |
5f361012 | 292 | test_if = SET_SRC (pc_set (jump)); |
9ec6d7ab RH |
293 | else |
294 | return NULL_RTX; | |
295 | cond = XEXP (test_if, 0); | |
296 | ||
297 | /* If this branches to JUMP_LABEL when the condition is false, | |
298 | reverse the condition. */ | |
299 | if (GET_CODE (XEXP (test_if, 2)) == LABEL_REF | |
300 | && XEXP (XEXP (test_if, 2), 0) == JUMP_LABEL (jump)) | |
b1b0700d RH |
301 | { |
302 | enum rtx_code rev = reversed_comparison_code (cond, jump); | |
303 | if (rev == UNKNOWN) | |
304 | return NULL_RTX; | |
305 | ||
306 | cond = gen_rtx_fmt_ee (rev, GET_MODE (cond), XEXP (cond, 0), | |
307 | XEXP (cond, 1)); | |
308 | } | |
9ec6d7ab RH |
309 | |
310 | return cond; | |
311 | } | |
312 | ||
313 | /* Given a simple IF-THEN or IF-THEN-ELSE block, attempt to convert it | |
314 | to conditional execution. Return TRUE if we were successful at | |
315 | converting the the block. */ | |
316 | ||
317 | static int | |
318 | cond_exec_process_if_block (test_bb, then_bb, else_bb, join_bb) | |
319 | basic_block test_bb; /* Basic block test is in */ | |
320 | basic_block then_bb; /* Basic block for THEN block */ | |
321 | basic_block else_bb; /* Basic block for ELSE block */ | |
322 | basic_block join_bb; /* Basic block the join label is in */ | |
323 | { | |
324 | rtx test_expr; /* expression in IF_THEN_ELSE that is tested */ | |
325 | rtx then_start; /* first insn in THEN block */ | |
326 | rtx then_end; /* last insn + 1 in THEN block */ | |
5ac9118e KG |
327 | rtx else_start = NULL_RTX; /* first insn in ELSE block or NULL */ |
328 | rtx else_end = NULL_RTX; /* last insn + 1 in ELSE block */ | |
dc297297 | 329 | int max; /* max # of insns to convert. */ |
9ec6d7ab RH |
330 | int then_mod_ok; /* whether conditional mods are ok in THEN */ |
331 | rtx true_expr; /* test for else block insns */ | |
332 | rtx false_expr; /* test for then block insns */ | |
2ff00dd4 RH |
333 | rtx true_prob_val; /* probability of else block */ |
334 | rtx false_prob_val; /* probability of then block */ | |
9ec6d7ab | 335 | int n_insns; |
b1b0700d | 336 | enum rtx_code false_code; |
9ec6d7ab RH |
337 | |
338 | /* Find the conditional jump to the ELSE or JOIN part, and isolate | |
339 | the test. */ | |
340 | test_expr = cond_exec_get_condition (test_bb->end); | |
341 | if (! test_expr) | |
342 | return FALSE; | |
343 | ||
2bc63114 JL |
344 | /* If the conditional jump is more than just a conditional jump, |
345 | then we can not do conditional execution conversion on this block. */ | |
346 | if (!onlyjump_p (test_bb->end)) | |
347 | return FALSE; | |
348 | ||
9ec6d7ab RH |
349 | /* Collect the bounds of where we're to search. */ |
350 | ||
351 | then_start = then_bb->head; | |
352 | then_end = then_bb->end; | |
353 | ||
7f9d9ea1 RH |
354 | /* Skip a label heading THEN block. */ |
355 | if (GET_CODE (then_start) == CODE_LABEL) | |
356 | then_start = NEXT_INSN (then_start); | |
357 | ||
9ec6d7ab RH |
358 | /* Skip a (use (const_int 0)) or branch as the final insn. */ |
359 | if (GET_CODE (then_end) == INSN | |
360 | && GET_CODE (PATTERN (then_end)) == USE | |
361 | && GET_CODE (XEXP (PATTERN (then_end), 0)) == CONST_INT) | |
362 | then_end = PREV_INSN (then_end); | |
363 | else if (GET_CODE (then_end) == JUMP_INSN) | |
364 | then_end = PREV_INSN (then_end); | |
365 | ||
366 | if (else_bb) | |
367 | { | |
368 | /* Skip the ELSE block's label. */ | |
369 | else_start = NEXT_INSN (else_bb->head); | |
370 | else_end = else_bb->end; | |
371 | ||
372 | /* Skip a (use (const_int 0)) or branch as the final insn. */ | |
373 | if (GET_CODE (else_end) == INSN | |
374 | && GET_CODE (PATTERN (else_end)) == USE | |
375 | && GET_CODE (XEXP (PATTERN (else_end), 0)) == CONST_INT) | |
376 | else_end = PREV_INSN (else_end); | |
377 | else if (GET_CODE (else_end) == JUMP_INSN) | |
378 | else_end = PREV_INSN (else_end); | |
379 | } | |
380 | ||
381 | /* How many instructions should we convert in total? */ | |
382 | n_insns = 0; | |
383 | if (else_bb) | |
384 | { | |
385 | max = 2 * MAX_CONDITIONAL_EXECUTE; | |
386 | n_insns = count_bb_insns (else_bb); | |
387 | } | |
388 | else | |
389 | max = MAX_CONDITIONAL_EXECUTE; | |
390 | n_insns += count_bb_insns (then_bb); | |
391 | if (n_insns > max) | |
392 | return FALSE; | |
393 | ||
394 | /* Map test_expr/test_jump into the appropriate MD tests to use on | |
395 | the conditionally executed code. */ | |
396 | ||
397 | true_expr = test_expr; | |
b1b0700d RH |
398 | |
399 | false_code = reversed_comparison_code (true_expr, test_bb->end); | |
400 | if (false_code != UNKNOWN) | |
401 | false_expr = gen_rtx_fmt_ee (false_code, GET_MODE (true_expr), | |
402 | XEXP (true_expr, 0), XEXP (true_expr, 1)); | |
403 | else | |
404 | false_expr = NULL_RTX; | |
9ec6d7ab | 405 | |
90280148 MM |
406 | #ifdef IFCVT_MODIFY_TESTS |
407 | /* If the machine description needs to modify the tests, such as setting a | |
408 | conditional execution register from a comparison, it can do so here. */ | |
409 | IFCVT_MODIFY_TESTS (true_expr, false_expr, test_bb, then_bb, else_bb, | |
410 | join_bb); | |
411 | ||
412 | /* See if the conversion failed */ | |
413 | if (!true_expr || !false_expr) | |
414 | goto fail; | |
415 | #endif | |
416 | ||
2ff00dd4 RH |
417 | true_prob_val = find_reg_note (test_bb->end, REG_BR_PROB, NULL_RTX); |
418 | if (true_prob_val) | |
419 | { | |
420 | true_prob_val = XEXP (true_prob_val, 0); | |
421 | false_prob_val = GEN_INT (REG_BR_PROB_BASE - INTVAL (true_prob_val)); | |
422 | } | |
423 | else | |
424 | false_prob_val = NULL_RTX; | |
425 | ||
9ec6d7ab RH |
426 | /* For IF-THEN-ELSE blocks, we don't allow modifications of the test |
427 | on then THEN block. */ | |
428 | then_mod_ok = (else_bb == NULL_BLOCK); | |
429 | ||
430 | /* Go through the THEN and ELSE blocks converting the insns if possible | |
431 | to conditional execution. */ | |
432 | ||
433 | if (then_end | |
b1b0700d RH |
434 | && (! false_expr |
435 | || ! cond_exec_process_insns (then_start, then_end, false_expr, | |
436 | false_prob_val, then_mod_ok))) | |
9ec6d7ab RH |
437 | goto fail; |
438 | ||
439 | if (else_bb | |
440 | && ! cond_exec_process_insns (else_start, else_end, | |
2ff00dd4 | 441 | true_expr, true_prob_val, TRUE)) |
9ec6d7ab RH |
442 | goto fail; |
443 | ||
444 | if (! apply_change_group ()) | |
445 | return FALSE; | |
446 | ||
90280148 MM |
447 | #ifdef IFCVT_MODIFY_FINAL |
448 | /* Do any machine dependent final modifications */ | |
449 | IFCVT_MODIFY_FINAL (test_bb, then_bb, else_bb, join_bb); | |
450 | #endif | |
451 | ||
9ec6d7ab RH |
452 | /* Conversion succeeded. */ |
453 | if (rtl_dump_file) | |
454 | fprintf (rtl_dump_file, "%d insn%s converted to conditional execution.\n", | |
455 | n_insns, (n_insns == 1) ? " was" : "s were"); | |
456 | ||
457 | /* Merge the blocks! */ | |
458 | merge_if_block (test_bb, then_bb, else_bb, join_bb); | |
459 | return TRUE; | |
460 | ||
461 | fail: | |
90280148 MM |
462 | #ifdef IFCVT_MODIFY_CANCEL |
463 | /* Cancel any machine dependent changes. */ | |
464 | IFCVT_MODIFY_CANCEL (test_bb, then_bb, else_bb, join_bb); | |
465 | #endif | |
466 | ||
9ec6d7ab RH |
467 | cancel_changes (0); |
468 | return FALSE; | |
469 | } | |
470 | \f | |
471 | /* Used by noce_process_if_block to communicate with its subroutines. | |
472 | ||
473 | The subroutines know that A and B may be evaluated freely. They | |
474 | know that X is a register. They should insert new instructions | |
475 | before cond_earliest. */ | |
476 | ||
477 | struct noce_if_info | |
478 | { | |
05cc23e8 | 479 | basic_block test_bb; |
9ec6d7ab RH |
480 | rtx insn_a, insn_b; |
481 | rtx x, a, b; | |
482 | rtx jump, cond, cond_earliest; | |
483 | }; | |
484 | ||
485 | static rtx noce_emit_store_flag PARAMS ((struct noce_if_info *, | |
486 | rtx, int, int)); | |
487 | static int noce_try_store_flag PARAMS ((struct noce_if_info *)); | |
488 | static int noce_try_store_flag_inc PARAMS ((struct noce_if_info *)); | |
489 | static int noce_try_store_flag_constants PARAMS ((struct noce_if_info *)); | |
490 | static int noce_try_store_flag_mask PARAMS ((struct noce_if_info *)); | |
491 | static rtx noce_emit_cmove PARAMS ((struct noce_if_info *, | |
492 | rtx, enum rtx_code, rtx, | |
493 | rtx, rtx, rtx)); | |
494 | static int noce_try_cmove PARAMS ((struct noce_if_info *)); | |
495 | static int noce_try_cmove_arith PARAMS ((struct noce_if_info *)); | |
05cc23e8 RH |
496 | static rtx noce_get_alt_condition PARAMS ((struct noce_if_info *, |
497 | rtx, rtx *)); | |
498 | static int noce_try_minmax PARAMS ((struct noce_if_info *)); | |
499 | static int noce_try_abs PARAMS ((struct noce_if_info *)); | |
9ec6d7ab RH |
500 | |
501 | /* Helper function for noce_try_store_flag*. */ | |
502 | ||
503 | static rtx | |
504 | noce_emit_store_flag (if_info, x, reversep, normalize) | |
505 | struct noce_if_info *if_info; | |
506 | rtx x; | |
507 | int reversep, normalize; | |
508 | { | |
509 | rtx cond = if_info->cond; | |
510 | int cond_complex; | |
511 | enum rtx_code code; | |
512 | ||
513 | cond_complex = (! general_operand (XEXP (cond, 0), VOIDmode) | |
514 | || ! general_operand (XEXP (cond, 1), VOIDmode)); | |
515 | ||
516 | /* If earliest == jump, or when the condition is complex, try to | |
517 | build the store_flag insn directly. */ | |
518 | ||
519 | if (cond_complex) | |
37f25cb9 | 520 | cond = XEXP (SET_SRC (pc_set (if_info->jump)), 0); |
9ec6d7ab | 521 | |
dc2698bc JH |
522 | if (reversep) |
523 | code = reversed_comparison_code (cond, if_info->jump); | |
524 | else | |
525 | code = GET_CODE (cond); | |
526 | ||
9ec6d7ab RH |
527 | if ((if_info->cond_earliest == if_info->jump || cond_complex) |
528 | && (normalize == 0 || STORE_FLAG_VALUE == normalize)) | |
529 | { | |
530 | rtx tmp; | |
531 | ||
9ec6d7ab RH |
532 | tmp = gen_rtx_fmt_ee (code, GET_MODE (x), XEXP (cond, 0), |
533 | XEXP (cond, 1)); | |
534 | tmp = gen_rtx_SET (VOIDmode, x, tmp); | |
535 | ||
536 | start_sequence (); | |
537 | tmp = emit_insn (tmp); | |
538 | ||
539 | if (recog_memoized (tmp) >= 0) | |
540 | { | |
541 | tmp = get_insns (); | |
542 | end_sequence (); | |
543 | emit_insns (tmp); | |
544 | ||
545 | if_info->cond_earliest = if_info->jump; | |
546 | ||
547 | return x; | |
548 | } | |
549 | ||
550 | end_sequence (); | |
551 | } | |
552 | ||
553 | /* Don't even try if the comparison operands are weird. */ | |
554 | if (cond_complex) | |
555 | return NULL_RTX; | |
556 | ||
9ec6d7ab RH |
557 | return emit_store_flag (x, code, XEXP (cond, 0), |
558 | XEXP (cond, 1), VOIDmode, | |
559 | (code == LTU || code == LEU | |
560 | || code == GEU || code == GTU), normalize); | |
561 | } | |
562 | ||
32ff70d2 JJ |
563 | /* Emit instruction to move a rtx into STRICT_LOW_PART. */ |
564 | static void | |
565 | noce_emit_move_insn (x, y) | |
566 | rtx x, y; | |
567 | { | |
568 | enum machine_mode outmode, inmode; | |
569 | rtx outer, inner; | |
570 | int bitpos; | |
571 | ||
572 | if (GET_CODE (x) != STRICT_LOW_PART) | |
573 | { | |
574 | emit_move_insn (x, y); | |
575 | return; | |
576 | } | |
577 | ||
578 | outer = XEXP (x, 0); | |
579 | inner = XEXP (outer, 0); | |
580 | outmode = GET_MODE (outer); | |
581 | inmode = GET_MODE (inner); | |
ddef6bc7 | 582 | bitpos = SUBREG_BYTE (outer) * BITS_PER_UNIT; |
32ff70d2 JJ |
583 | store_bit_field (inner, GET_MODE_BITSIZE (outmode), |
584 | bitpos, outmode, y, GET_MODE_BITSIZE (inmode), | |
585 | GET_MODE_BITSIZE (inmode)); | |
586 | } | |
587 | ||
9ec6d7ab RH |
588 | /* Convert "if (test) x = 1; else x = 0". |
589 | ||
590 | Only try 0 and STORE_FLAG_VALUE here. Other combinations will be | |
591 | tried in noce_try_store_flag_constants after noce_try_cmove has had | |
592 | a go at the conversion. */ | |
593 | ||
594 | static int | |
595 | noce_try_store_flag (if_info) | |
596 | struct noce_if_info *if_info; | |
597 | { | |
598 | int reversep; | |
599 | rtx target, seq; | |
600 | ||
601 | if (GET_CODE (if_info->b) == CONST_INT | |
602 | && INTVAL (if_info->b) == STORE_FLAG_VALUE | |
603 | && if_info->a == const0_rtx) | |
604 | reversep = 0; | |
605 | else if (if_info->b == const0_rtx | |
606 | && GET_CODE (if_info->a) == CONST_INT | |
607 | && INTVAL (if_info->a) == STORE_FLAG_VALUE | |
dc2698bc JH |
608 | && (reversed_comparison_code (if_info->cond, if_info->jump) |
609 | != UNKNOWN)) | |
9ec6d7ab RH |
610 | reversep = 1; |
611 | else | |
612 | return FALSE; | |
613 | ||
614 | start_sequence (); | |
615 | ||
616 | target = noce_emit_store_flag (if_info, if_info->x, reversep, 0); | |
617 | if (target) | |
618 | { | |
619 | if (target != if_info->x) | |
32ff70d2 | 620 | noce_emit_move_insn (if_info->x, target); |
9ec6d7ab RH |
621 | |
622 | seq = get_insns (); | |
623 | end_sequence (); | |
624 | emit_insns_before (seq, if_info->cond_earliest); | |
625 | ||
626 | return TRUE; | |
627 | } | |
628 | else | |
629 | { | |
630 | end_sequence (); | |
631 | return FALSE; | |
632 | } | |
633 | } | |
634 | ||
635 | /* Convert "if (test) x = a; else x = b", for A and B constant. */ | |
636 | ||
637 | static int | |
638 | noce_try_store_flag_constants (if_info) | |
639 | struct noce_if_info *if_info; | |
640 | { | |
641 | rtx target, seq; | |
642 | int reversep; | |
643 | HOST_WIDE_INT itrue, ifalse, diff, tmp; | |
644 | int normalize, can_reverse; | |
d54ef62c | 645 | enum machine_mode mode; |
9ec6d7ab RH |
646 | |
647 | if (! no_new_pseudos | |
648 | && GET_CODE (if_info->a) == CONST_INT | |
649 | && GET_CODE (if_info->b) == CONST_INT) | |
650 | { | |
d54ef62c | 651 | mode = GET_MODE (if_info->x); |
9ec6d7ab RH |
652 | ifalse = INTVAL (if_info->a); |
653 | itrue = INTVAL (if_info->b); | |
038fb2bc | 654 | diff = trunc_int_for_mode (itrue - ifalse, mode); |
9ec6d7ab | 655 | |
dc2698bc JH |
656 | can_reverse = (reversed_comparison_code (if_info->cond, if_info->jump) |
657 | != UNKNOWN); | |
9ec6d7ab RH |
658 | |
659 | reversep = 0; | |
660 | if (diff == STORE_FLAG_VALUE || diff == -STORE_FLAG_VALUE) | |
661 | normalize = 0; | |
662 | else if (ifalse == 0 && exact_log2 (itrue) >= 0 | |
663 | && (STORE_FLAG_VALUE == 1 | |
664 | || BRANCH_COST >= 2)) | |
665 | normalize = 1; | |
666 | else if (itrue == 0 && exact_log2 (ifalse) >= 0 && can_reverse | |
667 | && (STORE_FLAG_VALUE == 1 || BRANCH_COST >= 2)) | |
668 | normalize = 1, reversep = 1; | |
669 | else if (itrue == -1 | |
670 | && (STORE_FLAG_VALUE == -1 | |
671 | || BRANCH_COST >= 2)) | |
672 | normalize = -1; | |
673 | else if (ifalse == -1 && can_reverse | |
674 | && (STORE_FLAG_VALUE == -1 || BRANCH_COST >= 2)) | |
675 | normalize = -1, reversep = 1; | |
676 | else if ((BRANCH_COST >= 2 && STORE_FLAG_VALUE == -1) | |
677 | || BRANCH_COST >= 3) | |
678 | normalize = -1; | |
679 | else | |
680 | return FALSE; | |
681 | ||
682 | if (reversep) | |
683 | { | |
684 | tmp = itrue; itrue = ifalse; ifalse = tmp; | |
038fb2bc | 685 | diff = trunc_int_for_mode (-diff, mode); |
9ec6d7ab RH |
686 | } |
687 | ||
688 | start_sequence (); | |
689 | target = noce_emit_store_flag (if_info, if_info->x, reversep, normalize); | |
690 | if (! target) | |
691 | { | |
692 | end_sequence (); | |
693 | return FALSE; | |
694 | } | |
695 | ||
696 | /* if (test) x = 3; else x = 4; | |
697 | => x = 3 + (test == 0); */ | |
698 | if (diff == STORE_FLAG_VALUE || diff == -STORE_FLAG_VALUE) | |
699 | { | |
d54ef62c | 700 | target = expand_binop (mode, |
9ec6d7ab RH |
701 | (diff == STORE_FLAG_VALUE |
702 | ? add_optab : sub_optab), | |
703 | GEN_INT (ifalse), target, if_info->x, 0, | |
704 | OPTAB_WIDEN); | |
705 | } | |
706 | ||
707 | /* if (test) x = 8; else x = 0; | |
708 | => x = (test != 0) << 3; */ | |
709 | else if (ifalse == 0 && (tmp = exact_log2 (itrue)) >= 0) | |
710 | { | |
d54ef62c | 711 | target = expand_binop (mode, ashl_optab, |
9ec6d7ab RH |
712 | target, GEN_INT (tmp), if_info->x, 0, |
713 | OPTAB_WIDEN); | |
714 | } | |
715 | ||
716 | /* if (test) x = -1; else x = b; | |
717 | => x = -(test != 0) | b; */ | |
718 | else if (itrue == -1) | |
719 | { | |
d54ef62c | 720 | target = expand_binop (mode, ior_optab, |
9ec6d7ab RH |
721 | target, GEN_INT (ifalse), if_info->x, 0, |
722 | OPTAB_WIDEN); | |
723 | } | |
724 | ||
725 | /* if (test) x = a; else x = b; | |
726 | => x = (-(test != 0) & (b - a)) + a; */ | |
727 | else | |
728 | { | |
d54ef62c | 729 | target = expand_binop (mode, and_optab, |
9ec6d7ab RH |
730 | target, GEN_INT (diff), if_info->x, 0, |
731 | OPTAB_WIDEN); | |
732 | if (target) | |
d54ef62c | 733 | target = expand_binop (mode, add_optab, |
9ec6d7ab RH |
734 | target, GEN_INT (ifalse), if_info->x, 0, |
735 | OPTAB_WIDEN); | |
736 | } | |
737 | ||
738 | if (! target) | |
739 | { | |
740 | end_sequence (); | |
741 | return FALSE; | |
742 | } | |
743 | ||
744 | if (target != if_info->x) | |
32ff70d2 | 745 | noce_emit_move_insn (if_info->x, target); |
9ec6d7ab RH |
746 | |
747 | seq = get_insns (); | |
748 | end_sequence (); | |
4e4017cb RH |
749 | |
750 | if (seq_contains_jump (seq)) | |
751 | return FALSE; | |
752 | ||
9ec6d7ab RH |
753 | emit_insns_before (seq, if_info->cond_earliest); |
754 | ||
755 | return TRUE; | |
756 | } | |
757 | ||
758 | return FALSE; | |
759 | } | |
760 | ||
761 | /* Convert "if (test) foo++" into "foo += (test != 0)", and | |
762 | similarly for "foo--". */ | |
763 | ||
764 | static int | |
765 | noce_try_store_flag_inc (if_info) | |
766 | struct noce_if_info *if_info; | |
767 | { | |
768 | rtx target, seq; | |
769 | int subtract, normalize; | |
770 | ||
771 | if (! no_new_pseudos | |
772 | && (BRANCH_COST >= 2 | |
773 | || HAVE_incscc | |
774 | || HAVE_decscc) | |
775 | /* Should be no `else' case to worry about. */ | |
776 | && if_info->b == if_info->x | |
777 | && GET_CODE (if_info->a) == PLUS | |
778 | && (XEXP (if_info->a, 1) == const1_rtx | |
779 | || XEXP (if_info->a, 1) == constm1_rtx) | |
780 | && rtx_equal_p (XEXP (if_info->a, 0), if_info->x) | |
dc2698bc JH |
781 | && (reversed_comparison_code (if_info->cond, if_info->jump) |
782 | != UNKNOWN)) | |
9ec6d7ab RH |
783 | { |
784 | if (STORE_FLAG_VALUE == INTVAL (XEXP (if_info->a, 1))) | |
785 | subtract = 0, normalize = 0; | |
786 | else if (-STORE_FLAG_VALUE == INTVAL (XEXP (if_info->a, 1))) | |
787 | subtract = 1, normalize = 0; | |
788 | else | |
789 | subtract = 0, normalize = INTVAL (XEXP (if_info->a, 1)); | |
790 | ||
791 | start_sequence (); | |
792 | ||
793 | target = noce_emit_store_flag (if_info, | |
794 | gen_reg_rtx (GET_MODE (if_info->x)), | |
795 | 1, normalize); | |
796 | ||
797 | if (target) | |
798 | target = expand_binop (GET_MODE (if_info->x), | |
799 | subtract ? sub_optab : add_optab, | |
800 | if_info->x, target, if_info->x, 0, OPTAB_WIDEN); | |
801 | if (target) | |
802 | { | |
803 | if (target != if_info->x) | |
32ff70d2 | 804 | noce_emit_move_insn (if_info->x, target); |
9ec6d7ab RH |
805 | |
806 | seq = get_insns (); | |
807 | end_sequence (); | |
4e4017cb RH |
808 | |
809 | if (seq_contains_jump (seq)) | |
810 | return FALSE; | |
811 | ||
9ec6d7ab RH |
812 | emit_insns_before (seq, if_info->cond_earliest); |
813 | ||
814 | return TRUE; | |
815 | } | |
816 | ||
817 | end_sequence (); | |
818 | } | |
819 | ||
820 | return FALSE; | |
821 | } | |
822 | ||
823 | /* Convert "if (test) x = 0;" to "x &= -(test == 0);" */ | |
824 | ||
825 | static int | |
826 | noce_try_store_flag_mask (if_info) | |
827 | struct noce_if_info *if_info; | |
828 | { | |
829 | rtx target, seq; | |
830 | int reversep; | |
831 | ||
832 | reversep = 0; | |
833 | if (! no_new_pseudos | |
834 | && (BRANCH_COST >= 2 | |
835 | || STORE_FLAG_VALUE == -1) | |
836 | && ((if_info->a == const0_rtx | |
837 | && rtx_equal_p (if_info->b, if_info->x)) | |
dc2698bc JH |
838 | || ((reversep = (reversed_comparison_code (if_info->cond, |
839 | if_info->jump) | |
840 | != UNKNOWN)) | |
9ec6d7ab RH |
841 | && if_info->b == const0_rtx |
842 | && rtx_equal_p (if_info->a, if_info->x)))) | |
843 | { | |
844 | start_sequence (); | |
845 | target = noce_emit_store_flag (if_info, | |
846 | gen_reg_rtx (GET_MODE (if_info->x)), | |
847 | reversep, -1); | |
848 | if (target) | |
849 | target = expand_binop (GET_MODE (if_info->x), and_optab, | |
850 | if_info->x, target, if_info->x, 0, | |
851 | OPTAB_WIDEN); | |
852 | ||
853 | if (target) | |
854 | { | |
855 | if (target != if_info->x) | |
32ff70d2 | 856 | noce_emit_move_insn (if_info->x, target); |
9ec6d7ab RH |
857 | |
858 | seq = get_insns (); | |
859 | end_sequence (); | |
4e4017cb RH |
860 | |
861 | if (seq_contains_jump (seq)) | |
862 | return FALSE; | |
863 | ||
9ec6d7ab RH |
864 | emit_insns_before (seq, if_info->cond_earliest); |
865 | ||
866 | return TRUE; | |
867 | } | |
868 | ||
869 | end_sequence (); | |
870 | } | |
871 | ||
872 | return FALSE; | |
873 | } | |
874 | ||
875 | /* Helper function for noce_try_cmove and noce_try_cmove_arith. */ | |
876 | ||
877 | static rtx | |
878 | noce_emit_cmove (if_info, x, code, cmp_a, cmp_b, vfalse, vtrue) | |
879 | struct noce_if_info *if_info; | |
880 | rtx x, cmp_a, cmp_b, vfalse, vtrue; | |
881 | enum rtx_code code; | |
882 | { | |
883 | /* If earliest == jump, try to build the cmove insn directly. | |
884 | This is helpful when combine has created some complex condition | |
885 | (like for alpha's cmovlbs) that we can't hope to regenerate | |
886 | through the normal interface. */ | |
887 | ||
888 | if (if_info->cond_earliest == if_info->jump) | |
889 | { | |
890 | rtx tmp; | |
891 | ||
892 | tmp = gen_rtx_fmt_ee (code, GET_MODE (if_info->cond), cmp_a, cmp_b); | |
893 | tmp = gen_rtx_IF_THEN_ELSE (GET_MODE (x), tmp, vtrue, vfalse); | |
894 | tmp = gen_rtx_SET (VOIDmode, x, tmp); | |
895 | ||
896 | start_sequence (); | |
897 | tmp = emit_insn (tmp); | |
898 | ||
899 | if (recog_memoized (tmp) >= 0) | |
900 | { | |
901 | tmp = get_insns (); | |
902 | end_sequence (); | |
903 | emit_insns (tmp); | |
904 | ||
905 | return x; | |
906 | } | |
907 | ||
908 | end_sequence (); | |
909 | } | |
910 | ||
911 | /* Don't even try if the comparison operands are weird. */ | |
912 | if (! general_operand (cmp_a, GET_MODE (cmp_a)) | |
913 | || ! general_operand (cmp_b, GET_MODE (cmp_b))) | |
914 | return NULL_RTX; | |
915 | ||
7e04d3c7 | 916 | #if HAVE_conditional_move |
9ec6d7ab RH |
917 | return emit_conditional_move (x, code, cmp_a, cmp_b, VOIDmode, |
918 | vtrue, vfalse, GET_MODE (x), | |
919 | (code == LTU || code == GEU | |
920 | || code == LEU || code == GTU)); | |
7e04d3c7 RH |
921 | #else |
922 | /* We'll never get here, as noce_process_if_block doesn't call the | |
923 | functions involved. Ifdef code, however, should be discouraged | |
924 | because it leads to typos in the code not selected. However, | |
925 | emit_conditional_move won't exist either. */ | |
926 | return NULL_RTX; | |
927 | #endif | |
9ec6d7ab RH |
928 | } |
929 | ||
930 | /* Try only simple constants and registers here. More complex cases | |
931 | are handled in noce_try_cmove_arith after noce_try_store_flag_arith | |
932 | has had a go at it. */ | |
933 | ||
934 | static int | |
935 | noce_try_cmove (if_info) | |
936 | struct noce_if_info *if_info; | |
937 | { | |
938 | enum rtx_code code; | |
939 | rtx target, seq; | |
940 | ||
941 | if ((CONSTANT_P (if_info->a) || register_operand (if_info->a, VOIDmode)) | |
942 | && (CONSTANT_P (if_info->b) || register_operand (if_info->b, VOIDmode))) | |
943 | { | |
944 | start_sequence (); | |
945 | ||
946 | code = GET_CODE (if_info->cond); | |
947 | target = noce_emit_cmove (if_info, if_info->x, code, | |
948 | XEXP (if_info->cond, 0), | |
949 | XEXP (if_info->cond, 1), | |
950 | if_info->a, if_info->b); | |
951 | ||
952 | if (target) | |
953 | { | |
954 | if (target != if_info->x) | |
32ff70d2 | 955 | noce_emit_move_insn (if_info->x, target); |
9ec6d7ab RH |
956 | |
957 | seq = get_insns (); | |
958 | end_sequence (); | |
959 | emit_insns_before (seq, if_info->cond_earliest); | |
960 | return TRUE; | |
961 | } | |
962 | else | |
963 | { | |
964 | end_sequence (); | |
965 | return FALSE; | |
966 | } | |
967 | } | |
968 | ||
969 | return FALSE; | |
970 | } | |
971 | ||
972 | /* Try more complex cases involving conditional_move. */ | |
973 | ||
974 | static int | |
975 | noce_try_cmove_arith (if_info) | |
976 | struct noce_if_info *if_info; | |
977 | { | |
978 | rtx a = if_info->a; | |
979 | rtx b = if_info->b; | |
980 | rtx x = if_info->x; | |
981 | rtx insn_a, insn_b; | |
982 | rtx tmp, target; | |
983 | int is_mem = 0; | |
984 | enum rtx_code code; | |
985 | ||
986 | /* A conditional move from two memory sources is equivalent to a | |
987 | conditional on their addresses followed by a load. Don't do this | |
988 | early because it'll screw alias analysis. Note that we've | |
989 | already checked for no side effects. */ | |
990 | if (! no_new_pseudos && cse_not_expected | |
991 | && GET_CODE (a) == MEM && GET_CODE (b) == MEM | |
992 | && BRANCH_COST >= 5) | |
993 | { | |
994 | a = XEXP (a, 0); | |
995 | b = XEXP (b, 0); | |
996 | x = gen_reg_rtx (Pmode); | |
997 | is_mem = 1; | |
998 | } | |
999 | ||
1000 | /* ??? We could handle this if we knew that a load from A or B could | |
ea49bef6 | 1001 | not fault. This is also true if we've already loaded |
9ec6d7ab | 1002 | from the address along the path from ENTRY. */ |
ea49bef6 | 1003 | else if (may_trap_p (a) || may_trap_p (b)) |
9ec6d7ab RH |
1004 | return FALSE; |
1005 | ||
1006 | /* if (test) x = a + b; else x = c - d; | |
1007 | => y = a + b; | |
1008 | x = c - d; | |
1009 | if (test) | |
1010 | x = y; | |
1011 | */ | |
1012 | ||
1013 | code = GET_CODE (if_info->cond); | |
1014 | insn_a = if_info->insn_a; | |
1015 | insn_b = if_info->insn_b; | |
1016 | ||
1017 | /* Possibly rearrange operands to make things come out more natural. */ | |
dc2698bc | 1018 | if (reversed_comparison_code (if_info->cond, if_info->jump) != UNKNOWN) |
9ec6d7ab RH |
1019 | { |
1020 | int reversep = 0; | |
1021 | if (rtx_equal_p (b, x)) | |
1022 | reversep = 1; | |
1023 | else if (general_operand (b, GET_MODE (b))) | |
1024 | reversep = 1; | |
1025 | ||
1026 | if (reversep) | |
1027 | { | |
dc2698bc | 1028 | code = reversed_comparison_code (if_info->cond, if_info->jump); |
9ec6d7ab RH |
1029 | tmp = a, a = b, b = tmp; |
1030 | tmp = insn_a, insn_a = insn_b, insn_b = tmp; | |
1031 | } | |
1032 | } | |
1033 | ||
1034 | start_sequence (); | |
1035 | ||
1036 | /* If either operand is complex, load it into a register first. | |
1037 | The best way to do this is to copy the original insn. In this | |
1038 | way we preserve any clobbers etc that the insn may have had. | |
1039 | This is of course not possible in the IS_MEM case. */ | |
1040 | if (! general_operand (a, GET_MODE (a))) | |
1041 | { | |
1042 | rtx set; | |
1043 | ||
1044 | if (no_new_pseudos) | |
1045 | goto end_seq_and_fail; | |
1046 | ||
1047 | if (is_mem) | |
1048 | { | |
1049 | tmp = gen_reg_rtx (GET_MODE (a)); | |
1050 | tmp = emit_insn (gen_rtx_SET (VOIDmode, tmp, a)); | |
1051 | } | |
1052 | else if (! insn_a) | |
1053 | goto end_seq_and_fail; | |
1054 | else | |
1055 | { | |
1056 | a = gen_reg_rtx (GET_MODE (a)); | |
1057 | tmp = copy_rtx (insn_a); | |
1058 | set = single_set (tmp); | |
1059 | SET_DEST (set) = a; | |
1060 | tmp = emit_insn (PATTERN (tmp)); | |
1061 | } | |
1062 | if (recog_memoized (tmp) < 0) | |
1063 | goto end_seq_and_fail; | |
1064 | } | |
1065 | if (! general_operand (b, GET_MODE (b))) | |
1066 | { | |
1067 | rtx set; | |
1068 | ||
1069 | if (no_new_pseudos) | |
1070 | goto end_seq_and_fail; | |
1071 | ||
1072 | if (is_mem) | |
1073 | { | |
1074 | tmp = gen_reg_rtx (GET_MODE (b)); | |
1075 | tmp = emit_insn (gen_rtx_SET (VOIDmode, tmp, b)); | |
1076 | } | |
1077 | else if (! insn_b) | |
1078 | goto end_seq_and_fail; | |
1079 | else | |
1080 | { | |
1081 | b = gen_reg_rtx (GET_MODE (b)); | |
1082 | tmp = copy_rtx (insn_b); | |
1083 | set = single_set (tmp); | |
1084 | SET_DEST (set) = b; | |
1085 | tmp = emit_insn (PATTERN (tmp)); | |
1086 | } | |
1087 | if (recog_memoized (tmp) < 0) | |
1088 | goto end_seq_and_fail; | |
1089 | } | |
1090 | ||
1091 | target = noce_emit_cmove (if_info, x, code, XEXP (if_info->cond, 0), | |
1092 | XEXP (if_info->cond, 1), a, b); | |
1093 | ||
1094 | if (! target) | |
1095 | goto end_seq_and_fail; | |
1096 | ||
1097 | /* If we're handling a memory for above, emit the load now. */ | |
1098 | if (is_mem) | |
1099 | { | |
1100 | tmp = gen_rtx_MEM (GET_MODE (if_info->x), target); | |
1101 | ||
1102 | /* Copy over flags as appropriate. */ | |
1103 | if (MEM_VOLATILE_P (if_info->a) || MEM_VOLATILE_P (if_info->b)) | |
1104 | MEM_VOLATILE_P (tmp) = 1; | |
1105 | if (MEM_IN_STRUCT_P (if_info->a) && MEM_IN_STRUCT_P (if_info->b)) | |
1106 | MEM_IN_STRUCT_P (tmp) = 1; | |
1107 | if (MEM_SCALAR_P (if_info->a) && MEM_SCALAR_P (if_info->b)) | |
1108 | MEM_SCALAR_P (tmp) = 1; | |
1109 | if (MEM_ALIAS_SET (if_info->a) == MEM_ALIAS_SET (if_info->b)) | |
ba4828e0 | 1110 | set_mem_alias_set (tmp, MEM_ALIAS_SET (if_info->a)); |
9ec6d7ab | 1111 | |
32ff70d2 | 1112 | noce_emit_move_insn (if_info->x, tmp); |
9ec6d7ab RH |
1113 | } |
1114 | else if (target != x) | |
32ff70d2 | 1115 | noce_emit_move_insn (x, target); |
9ec6d7ab RH |
1116 | |
1117 | tmp = get_insns (); | |
1118 | end_sequence (); | |
1119 | emit_insns_before (tmp, if_info->cond_earliest); | |
1120 | return TRUE; | |
1121 | ||
1122 | end_seq_and_fail: | |
1123 | end_sequence (); | |
1124 | return FALSE; | |
1125 | } | |
1126 | ||
05cc23e8 RH |
1127 | /* For most cases, the simplified condition we found is the best |
1128 | choice, but this is not the case for the min/max/abs transforms. | |
1129 | For these we wish to know that it is A or B in the condition. */ | |
1130 | ||
1131 | static rtx | |
1132 | noce_get_alt_condition (if_info, target, earliest) | |
1133 | struct noce_if_info *if_info; | |
1134 | rtx target; | |
1135 | rtx *earliest; | |
1136 | { | |
1137 | rtx cond, set, insn; | |
1138 | int reverse; | |
1139 | ||
1140 | /* If target is already mentioned in the known condition, return it. */ | |
1141 | if (reg_mentioned_p (target, if_info->cond)) | |
1142 | { | |
1143 | *earliest = if_info->cond_earliest; | |
1144 | return if_info->cond; | |
1145 | } | |
1146 | ||
1147 | set = pc_set (if_info->jump); | |
1148 | cond = XEXP (SET_SRC (set), 0); | |
1149 | reverse | |
1150 | = GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF | |
1151 | && XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (if_info->jump); | |
1152 | ||
7f646877 DD |
1153 | /* If we're looking for a constant, try to make the conditional |
1154 | have that constant in it. There are two reasons why it may | |
1155 | not have the constant we want: | |
1156 | ||
1157 | 1. GCC may have needed to put the constant in a register, because | |
1158 | the target can't compare directly against that constant. For | |
1159 | this case, we look for a SET immediately before the comparison | |
1160 | that puts a constant in that register. | |
1161 | ||
1162 | 2. GCC may have canonicalized the conditional, for example | |
1163 | replacing "if x < 4" with "if x <= 3". We can undo that (or | |
1164 | make equivalent types of changes) to get the constants we need | |
1165 | if they're off by one in the right direction. */ | |
1166 | ||
1167 | if (GET_CODE (target) == CONST_INT) | |
1168 | { | |
1169 | enum rtx_code code = GET_CODE (if_info->cond); | |
1170 | rtx op_a = XEXP (if_info->cond, 0); | |
1171 | rtx op_b = XEXP (if_info->cond, 1); | |
1172 | rtx prev_insn; | |
1173 | ||
1174 | /* First, look to see if we put a constant in a register. */ | |
1175 | prev_insn = PREV_INSN (if_info->cond_earliest); | |
1176 | if (prev_insn | |
1177 | && INSN_P (prev_insn) | |
1178 | && GET_CODE (PATTERN (prev_insn)) == SET) | |
1179 | { | |
1180 | rtx src = find_reg_equal_equiv_note (prev_insn); | |
1181 | if (!src) | |
1182 | src = SET_SRC (PATTERN (prev_insn)); | |
1183 | if (GET_CODE (src) == CONST_INT) | |
1184 | { | |
1185 | if (rtx_equal_p (op_a, SET_DEST (PATTERN (prev_insn)))) | |
667ccf73 | 1186 | op_a = src; |
7f646877 | 1187 | else if (rtx_equal_p (op_b, SET_DEST (PATTERN (prev_insn)))) |
667ccf73 | 1188 | op_b = src; |
7f646877 DD |
1189 | |
1190 | if (GET_CODE (op_a) == CONST_INT) | |
1191 | { | |
1192 | rtx tmp = op_a; | |
1193 | op_a = op_b; | |
1194 | op_b = tmp; | |
1195 | code = swap_condition (code); | |
1196 | } | |
1197 | } | |
1198 | } | |
1199 | ||
1200 | /* Now, look to see if we can get the right constant by | |
1201 | adjusting the conditional. */ | |
1202 | if (GET_CODE (op_b) == CONST_INT) | |
1203 | { | |
1204 | HOST_WIDE_INT desired_val = INTVAL (target); | |
1205 | HOST_WIDE_INT actual_val = INTVAL (op_b); | |
1206 | ||
1207 | switch (code) | |
1208 | { | |
1209 | case LT: | |
1210 | if (actual_val == desired_val + 1) | |
1211 | { | |
1212 | code = LE; | |
1213 | op_b = GEN_INT (desired_val); | |
1214 | } | |
1215 | break; | |
1216 | case LE: | |
1217 | if (actual_val == desired_val - 1) | |
1218 | { | |
1219 | code = LT; | |
1220 | op_b = GEN_INT (desired_val); | |
1221 | } | |
1222 | break; | |
1223 | case GT: | |
1224 | if (actual_val == desired_val - 1) | |
1225 | { | |
1226 | code = GE; | |
1227 | op_b = GEN_INT (desired_val); | |
1228 | } | |
1229 | break; | |
1230 | case GE: | |
1231 | if (actual_val == desired_val + 1) | |
1232 | { | |
1233 | code = GT; | |
1234 | op_b = GEN_INT (desired_val); | |
1235 | } | |
1236 | break; | |
1237 | default: | |
1238 | break; | |
1239 | } | |
1240 | } | |
1241 | ||
1242 | /* If we made any changes, generate a new conditional that is | |
1243 | equivalent to what we started with, but has the right | |
1244 | constants in it. */ | |
1245 | if (code != GET_CODE (if_info->cond) | |
1246 | || op_a != XEXP (if_info->cond, 0) | |
1247 | || op_b != XEXP (if_info->cond, 1)) | |
1248 | { | |
1249 | cond = gen_rtx_fmt_ee (code, GET_MODE (cond), op_a, op_b); | |
1250 | *earliest = if_info->cond_earliest; | |
1251 | return cond; | |
1252 | } | |
1253 | } | |
1254 | ||
05cc23e8 RH |
1255 | cond = canonicalize_condition (if_info->jump, cond, reverse, |
1256 | earliest, target); | |
1257 | if (! cond || ! reg_mentioned_p (target, cond)) | |
1258 | return NULL; | |
1259 | ||
1260 | /* We almost certainly searched back to a different place. | |
1261 | Need to re-verify correct lifetimes. */ | |
1262 | ||
1263 | /* X may not be mentioned in the range (cond_earliest, jump]. */ | |
1264 | for (insn = if_info->jump; insn != *earliest; insn = PREV_INSN (insn)) | |
1265 | if (INSN_P (insn) && reg_mentioned_p (if_info->x, insn)) | |
1266 | return NULL; | |
1267 | ||
1268 | /* A and B may not be modified in the range [cond_earliest, jump). */ | |
1269 | for (insn = *earliest; insn != if_info->jump; insn = NEXT_INSN (insn)) | |
1270 | if (INSN_P (insn) | |
1271 | && (modified_in_p (if_info->a, insn) | |
1272 | || modified_in_p (if_info->b, insn))) | |
1273 | return NULL; | |
1274 | ||
1275 | return cond; | |
1276 | } | |
1277 | ||
1278 | /* Convert "if (a < b) x = a; else x = b;" to "x = min(a, b);", etc. */ | |
1279 | ||
1280 | static int | |
1281 | noce_try_minmax (if_info) | |
1282 | struct noce_if_info *if_info; | |
1283 | { | |
1284 | rtx cond, earliest, target, seq; | |
1285 | enum rtx_code code; | |
1286 | int unsignedp; | |
1287 | optab op; | |
1288 | ||
1289 | /* ??? Can't guarantee that expand_binop won't create pseudos. */ | |
1290 | if (no_new_pseudos) | |
1291 | return FALSE; | |
1292 | ||
1293 | /* ??? Reject FP modes since we don't know how 0 vs -0 or NaNs | |
1294 | will be resolved with an SMIN/SMAX. It wouldn't be too hard | |
1295 | to get the target to tell us... */ | |
1296 | if (FLOAT_MODE_P (GET_MODE (if_info->x)) | |
1297 | && TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT | |
de6c5979 | 1298 | && ! flag_unsafe_math_optimizations) |
05cc23e8 RH |
1299 | return FALSE; |
1300 | ||
1301 | cond = noce_get_alt_condition (if_info, if_info->a, &earliest); | |
1302 | if (!cond) | |
1303 | return FALSE; | |
1304 | ||
1305 | /* Verify the condition is of the form we expect, and canonicalize | |
1306 | the comparison code. */ | |
1307 | code = GET_CODE (cond); | |
1308 | if (rtx_equal_p (XEXP (cond, 0), if_info->a)) | |
1309 | { | |
1310 | if (! rtx_equal_p (XEXP (cond, 1), if_info->b)) | |
1311 | return FALSE; | |
1312 | } | |
1313 | else if (rtx_equal_p (XEXP (cond, 1), if_info->a)) | |
1314 | { | |
1315 | if (! rtx_equal_p (XEXP (cond, 0), if_info->b)) | |
1316 | return FALSE; | |
1317 | code = swap_condition (code); | |
1318 | } | |
1319 | else | |
1320 | return FALSE; | |
1321 | ||
1322 | /* Determine what sort of operation this is. Note that the code is for | |
1323 | a taken branch, so the code->operation mapping appears backwards. */ | |
1324 | switch (code) | |
1325 | { | |
1326 | case LT: | |
1327 | case LE: | |
1328 | case UNLT: | |
1329 | case UNLE: | |
1330 | op = smax_optab; | |
1331 | unsignedp = 0; | |
1332 | break; | |
1333 | case GT: | |
1334 | case GE: | |
1335 | case UNGT: | |
1336 | case UNGE: | |
1337 | op = smin_optab; | |
1338 | unsignedp = 0; | |
1339 | break; | |
1340 | case LTU: | |
1341 | case LEU: | |
1342 | op = umax_optab; | |
1343 | unsignedp = 1; | |
1344 | break; | |
1345 | case GTU: | |
1346 | case GEU: | |
1347 | op = umin_optab; | |
1348 | unsignedp = 1; | |
1349 | break; | |
1350 | default: | |
1351 | return FALSE; | |
1352 | } | |
1353 | ||
1354 | start_sequence (); | |
1355 | ||
1356 | target = expand_binop (GET_MODE (if_info->x), op, if_info->a, if_info->b, | |
1357 | if_info->x, unsignedp, OPTAB_WIDEN); | |
1358 | if (! target) | |
1359 | { | |
1360 | end_sequence (); | |
1361 | return FALSE; | |
1362 | } | |
1363 | if (target != if_info->x) | |
32ff70d2 | 1364 | noce_emit_move_insn (if_info->x, target); |
05cc23e8 RH |
1365 | |
1366 | seq = get_insns (); | |
1367 | end_sequence (); | |
1368 | ||
1369 | if (seq_contains_jump (seq)) | |
1370 | return FALSE; | |
1371 | ||
1372 | emit_insns_before (seq, earliest); | |
1373 | if_info->cond = cond; | |
1374 | if_info->cond_earliest = earliest; | |
1375 | ||
1376 | return TRUE; | |
1377 | } | |
1378 | ||
1379 | /* Convert "if (a < 0) x = -a; else x = a;" to "x = abs(a);", etc. */ | |
1380 | ||
1381 | static int | |
1382 | noce_try_abs (if_info) | |
1383 | struct noce_if_info *if_info; | |
1384 | { | |
1385 | rtx cond, earliest, target, seq, a, b, c; | |
1386 | int negate; | |
1387 | ||
1388 | /* ??? Can't guarantee that expand_binop won't create pseudos. */ | |
1389 | if (no_new_pseudos) | |
1390 | return FALSE; | |
1391 | ||
1392 | /* Recognize A and B as constituting an ABS or NABS. */ | |
1393 | a = if_info->a; | |
1394 | b = if_info->b; | |
1395 | if (GET_CODE (a) == NEG && rtx_equal_p (XEXP (a, 0), b)) | |
1396 | negate = 0; | |
1397 | else if (GET_CODE (b) == NEG && rtx_equal_p (XEXP (b, 0), a)) | |
1398 | { | |
1399 | c = a; a = b; b = c; | |
1400 | negate = 1; | |
1401 | } | |
1402 | else | |
1403 | return FALSE; | |
1404 | ||
1405 | cond = noce_get_alt_condition (if_info, b, &earliest); | |
1406 | if (!cond) | |
1407 | return FALSE; | |
1408 | ||
1409 | /* Verify the condition is of the form we expect. */ | |
1410 | if (rtx_equal_p (XEXP (cond, 0), b)) | |
1411 | c = XEXP (cond, 1); | |
1412 | else if (rtx_equal_p (XEXP (cond, 1), b)) | |
1413 | c = XEXP (cond, 0); | |
1414 | else | |
1415 | return FALSE; | |
1416 | ||
1417 | /* Verify that C is zero. Search backward through the block for | |
1418 | a REG_EQUAL note if necessary. */ | |
1419 | if (REG_P (c)) | |
1420 | { | |
1421 | rtx insn, note = NULL; | |
1422 | for (insn = earliest; | |
1423 | insn != if_info->test_bb->head; | |
1424 | insn = PREV_INSN (insn)) | |
1425 | if (INSN_P (insn) | |
1426 | && ((note = find_reg_note (insn, REG_EQUAL, c)) | |
1427 | || (note = find_reg_note (insn, REG_EQUIV, c)))) | |
1428 | break; | |
1429 | if (! note) | |
1430 | return FALSE; | |
1431 | c = XEXP (note, 0); | |
1432 | } | |
1433 | if (GET_CODE (c) == MEM | |
1434 | && GET_CODE (XEXP (c, 0)) == SYMBOL_REF | |
1435 | && CONSTANT_POOL_ADDRESS_P (XEXP (c, 0))) | |
1436 | c = get_pool_constant (XEXP (c, 0)); | |
1437 | ||
1438 | /* Work around funny ideas get_condition has wrt canonicalization. | |
1439 | Note that these rtx constants are known to be CONST_INT, and | |
1440 | therefore imply integer comparisons. */ | |
1441 | if (c == constm1_rtx && GET_CODE (cond) == GT) | |
1442 | ; | |
1443 | else if (c == const1_rtx && GET_CODE (cond) == LT) | |
1444 | ; | |
1445 | else if (c != CONST0_RTX (GET_MODE (b))) | |
1446 | return FALSE; | |
1447 | ||
1448 | /* Determine what sort of operation this is. */ | |
1449 | switch (GET_CODE (cond)) | |
1450 | { | |
1451 | case LT: | |
1452 | case LE: | |
1453 | case UNLT: | |
1454 | case UNLE: | |
1455 | negate = !negate; | |
1456 | break; | |
1457 | case GT: | |
1458 | case GE: | |
1459 | case UNGT: | |
1460 | case UNGE: | |
1461 | break; | |
1462 | default: | |
1463 | return FALSE; | |
1464 | } | |
1465 | ||
1466 | start_sequence (); | |
1467 | ||
1468 | target = expand_unop (GET_MODE (if_info->x), abs_optab, b, if_info->x, 0); | |
1469 | ||
1470 | /* ??? It's a quandry whether cmove would be better here, especially | |
1471 | for integers. Perhaps combine will clean things up. */ | |
1472 | if (target && negate) | |
1473 | target = expand_unop (GET_MODE (target), neg_optab, target, if_info->x, 0); | |
1474 | ||
1475 | if (! target) | |
1476 | { | |
1477 | end_sequence (); | |
1478 | return FALSE; | |
1479 | } | |
1480 | ||
1481 | if (target != if_info->x) | |
32ff70d2 | 1482 | noce_emit_move_insn (if_info->x, target); |
05cc23e8 RH |
1483 | |
1484 | seq = get_insns (); | |
1485 | end_sequence (); | |
1486 | ||
1487 | if (seq_contains_jump (seq)) | |
1488 | return FALSE; | |
1489 | ||
1490 | emit_insns_before (seq, earliest); | |
1491 | if_info->cond = cond; | |
1492 | if_info->cond_earliest = earliest; | |
1493 | ||
1494 | return TRUE; | |
1495 | } | |
1496 | ||
9ec6d7ab RH |
1497 | /* Look for the condition for the jump first. We'd prefer to avoid |
1498 | get_condition if we can -- it tries to look back for the contents | |
1499 | of an original compare. On targets that use normal integers for | |
1500 | comparisons, e.g. alpha, this is wasteful. */ | |
1501 | ||
1502 | static rtx | |
1503 | noce_get_condition (jump, earliest) | |
1504 | rtx jump; | |
1505 | rtx *earliest; | |
1506 | { | |
1507 | rtx cond; | |
7f1c097d | 1508 | rtx set; |
9ec6d7ab RH |
1509 | |
1510 | /* If the condition variable is a register and is MODE_INT, accept it. | |
1511 | Otherwise, fall back on get_condition. */ | |
1512 | ||
7f1c097d | 1513 | if (! any_condjump_p (jump)) |
9ec6d7ab RH |
1514 | return NULL_RTX; |
1515 | ||
7f1c097d JH |
1516 | set = pc_set (jump); |
1517 | ||
1518 | cond = XEXP (SET_SRC (set), 0); | |
9ec6d7ab RH |
1519 | if (GET_CODE (XEXP (cond, 0)) == REG |
1520 | && GET_MODE_CLASS (GET_MODE (XEXP (cond, 0))) == MODE_INT) | |
1521 | { | |
1522 | *earliest = jump; | |
1523 | ||
1524 | /* If this branches to JUMP_LABEL when the condition is false, | |
1525 | reverse the condition. */ | |
7f1c097d JH |
1526 | if (GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF |
1527 | && XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (jump)) | |
9ec6d7ab RH |
1528 | cond = gen_rtx_fmt_ee (reverse_condition (GET_CODE (cond)), |
1529 | GET_MODE (cond), XEXP (cond, 0), | |
1530 | XEXP (cond, 1)); | |
1531 | } | |
1532 | else | |
1533 | cond = get_condition (jump, earliest); | |
1534 | ||
1535 | return cond; | |
1536 | } | |
1537 | ||
05cc23e8 RH |
1538 | /* Return true if OP is ok for if-then-else processing. */ |
1539 | ||
1540 | static int | |
1541 | noce_operand_ok (op) | |
1542 | rtx op; | |
1543 | { | |
1544 | /* We special-case memories, so handle any of them with | |
1545 | no address side effects. */ | |
1546 | if (GET_CODE (op) == MEM) | |
1547 | return ! side_effects_p (XEXP (op, 0)); | |
1548 | ||
1549 | if (side_effects_p (op)) | |
1550 | return FALSE; | |
1551 | ||
de6c5979 | 1552 | /* ??? Unfortuantely may_trap_p can't look at flag_trapping_math, due to |
05cc23e8 RH |
1553 | being linked into the genfoo programs. This is probably a mistake. |
1554 | With finite operands, most fp operations don't trap. */ | |
de6c5979 | 1555 | if (!flag_trapping_math && FLOAT_MODE_P (GET_MODE (op))) |
05cc23e8 RH |
1556 | switch (GET_CODE (op)) |
1557 | { | |
1558 | case DIV: | |
1559 | case MOD: | |
1560 | case UDIV: | |
1561 | case UMOD: | |
1562 | /* ??? This is kinda lame -- almost every target will have forced | |
1563 | the constant into a register first. But given the expense of | |
1564 | division, this is probably for the best. */ | |
1565 | return (CONSTANT_P (XEXP (op, 1)) | |
1566 | && XEXP (op, 1) != CONST0_RTX (GET_MODE (op)) | |
1567 | && ! may_trap_p (XEXP (op, 0))); | |
1568 | ||
1569 | default: | |
1570 | switch (GET_RTX_CLASS (GET_CODE (op))) | |
1571 | { | |
05cc23e8 | 1572 | case '1': |
68af29ce JH |
1573 | return ! may_trap_p (XEXP (op, 0)); |
1574 | case 'c': | |
05cc23e8 RH |
1575 | case '2': |
1576 | return ! may_trap_p (XEXP (op, 0)) && ! may_trap_p (XEXP (op, 1)); | |
1577 | } | |
1578 | break; | |
1579 | } | |
1580 | ||
1581 | return ! may_trap_p (op); | |
1582 | } | |
1583 | ||
9ec6d7ab RH |
1584 | /* Given a simple IF-THEN or IF-THEN-ELSE block, attempt to convert it |
1585 | without using conditional execution. Return TRUE if we were | |
1586 | successful at converting the the block. */ | |
1587 | ||
1588 | static int | |
1589 | noce_process_if_block (test_bb, then_bb, else_bb, join_bb) | |
1590 | basic_block test_bb; /* Basic block test is in */ | |
1591 | basic_block then_bb; /* Basic block for THEN block */ | |
1592 | basic_block else_bb; /* Basic block for ELSE block */ | |
1593 | basic_block join_bb; /* Basic block the join label is in */ | |
1594 | { | |
1595 | /* We're looking for patterns of the form | |
1596 | ||
1597 | (1) if (...) x = a; else x = b; | |
1598 | (2) x = b; if (...) x = a; | |
1599 | (3) if (...) x = a; // as if with an initial x = x. | |
1600 | ||
1601 | The later patterns require jumps to be more expensive. | |
1602 | ||
1603 | ??? For future expansion, look for multiple X in such patterns. */ | |
1604 | ||
1605 | struct noce_if_info if_info; | |
1606 | rtx insn_a, insn_b; | |
1607 | rtx set_a, set_b; | |
1608 | rtx orig_x, x, a, b; | |
c4686982 | 1609 | rtx jump, cond, insn; |
9ec6d7ab RH |
1610 | |
1611 | /* If this is not a standard conditional jump, we can't parse it. */ | |
1612 | jump = test_bb->end; | |
1613 | cond = noce_get_condition (jump, &if_info.cond_earliest); | |
1614 | if (! cond) | |
1615 | return FALSE; | |
1616 | ||
2bc63114 JL |
1617 | /* If the conditional jump is more than just a conditional jump, |
1618 | then we can not do if-conversion on this block. */ | |
1619 | if (! onlyjump_p (jump)) | |
1620 | return FALSE; | |
1621 | ||
9ec6d7ab RH |
1622 | /* We must be comparing objects whose modes imply the size. */ |
1623 | if (GET_MODE (XEXP (cond, 0)) == BLKmode) | |
1624 | return FALSE; | |
1625 | ||
1626 | /* Look for one of the potential sets. */ | |
1627 | insn_a = first_active_insn (then_bb); | |
1628 | if (! insn_a | |
1629 | || ! last_active_insn_p (then_bb, insn_a) | |
1630 | || (set_a = single_set (insn_a)) == NULL_RTX) | |
1631 | return FALSE; | |
1632 | ||
1633 | x = SET_DEST (set_a); | |
1634 | a = SET_SRC (set_a); | |
1635 | ||
1636 | /* Look for the other potential set. Make sure we've got equivalent | |
1637 | destinations. */ | |
1638 | /* ??? This is overconservative. Storing to two different mems is | |
1639 | as easy as conditionally computing the address. Storing to a | |
1640 | single mem merely requires a scratch memory to use as one of the | |
1641 | destination addresses; often the memory immediately below the | |
1642 | stack pointer is available for this. */ | |
1643 | set_b = NULL_RTX; | |
1644 | if (else_bb) | |
1645 | { | |
1646 | insn_b = first_active_insn (else_bb); | |
1647 | if (! insn_b | |
1648 | || ! last_active_insn_p (else_bb, insn_b) | |
1649 | || (set_b = single_set (insn_b)) == NULL_RTX | |
1650 | || ! rtx_equal_p (x, SET_DEST (set_b))) | |
1651 | return FALSE; | |
1652 | } | |
1653 | else | |
1654 | { | |
1655 | insn_b = prev_nonnote_insn (if_info.cond_earliest); | |
1656 | if (! insn_b | |
1657 | || GET_CODE (insn_b) != INSN | |
1658 | || (set_b = single_set (insn_b)) == NULL_RTX | |
1659 | || ! rtx_equal_p (x, SET_DEST (set_b)) | |
65189757 | 1660 | || reg_mentioned_p (x, cond) |
02a749ec RH |
1661 | || reg_mentioned_p (x, a) |
1662 | || reg_mentioned_p (x, SET_SRC (set_b))) | |
9ec6d7ab RH |
1663 | insn_b = set_b = NULL_RTX; |
1664 | } | |
1665 | b = (set_b ? SET_SRC (set_b) : x); | |
1666 | ||
0927ce96 RH |
1667 | /* X may not be mentioned in the range (cond_earliest, jump]. */ |
1668 | for (insn = jump; insn != if_info.cond_earliest; insn = PREV_INSN (insn)) | |
1669 | if (INSN_P (insn) && reg_mentioned_p (x, insn)) | |
1670 | return FALSE; | |
1671 | ||
1672 | /* A and B may not be modified in the range [cond_earliest, jump). */ | |
1673 | for (insn = if_info.cond_earliest; insn != jump; insn = NEXT_INSN (insn)) | |
1674 | if (INSN_P (insn) | |
1675 | && (modified_in_p (a, insn) || modified_in_p (b, insn))) | |
1676 | return FALSE; | |
1677 | ||
9ec6d7ab RH |
1678 | /* Only operate on register destinations, and even then avoid extending |
1679 | the lifetime of hard registers on small register class machines. */ | |
1680 | orig_x = x; | |
1681 | if (GET_CODE (x) != REG | |
1682 | || (SMALL_REGISTER_CLASSES | |
1683 | && REGNO (x) < FIRST_PSEUDO_REGISTER)) | |
1684 | { | |
1685 | if (no_new_pseudos) | |
1686 | return FALSE; | |
32ff70d2 JJ |
1687 | x = gen_reg_rtx (GET_MODE (GET_CODE (x) == STRICT_LOW_PART |
1688 | ? XEXP (x, 0) : x)); | |
9ec6d7ab RH |
1689 | } |
1690 | ||
1691 | /* Don't operate on sources that may trap or are volatile. */ | |
05cc23e8 | 1692 | if (! noce_operand_ok (a) || ! noce_operand_ok (b)) |
9ec6d7ab RH |
1693 | return FALSE; |
1694 | ||
1695 | /* Set up the info block for our subroutines. */ | |
05cc23e8 | 1696 | if_info.test_bb = test_bb; |
9ec6d7ab RH |
1697 | if_info.cond = cond; |
1698 | if_info.jump = jump; | |
1699 | if_info.insn_a = insn_a; | |
1700 | if_info.insn_b = insn_b; | |
1701 | if_info.x = x; | |
1702 | if_info.a = a; | |
1703 | if_info.b = b; | |
1704 | ||
1705 | /* Try optimizations in some approximation of a useful order. */ | |
1706 | /* ??? Should first look to see if X is live incoming at all. If it | |
1707 | isn't, we don't need anything but an unconditional set. */ | |
1708 | ||
1709 | /* Look and see if A and B are really the same. Avoid creating silly | |
1710 | cmove constructs that no one will fix up later. */ | |
1711 | if (rtx_equal_p (a, b)) | |
1712 | { | |
1713 | /* If we have an INSN_B, we don't have to create any new rtl. Just | |
1714 | move the instruction that we already have. If we don't have an | |
1715 | INSN_B, that means that A == X, and we've got a noop move. In | |
1716 | that case don't do anything and let the code below delete INSN_A. */ | |
1717 | if (insn_b && else_bb) | |
1718 | { | |
bca05d20 RK |
1719 | rtx note; |
1720 | ||
9ec6d7ab RH |
1721 | if (else_bb && insn_b == else_bb->end) |
1722 | else_bb->end = PREV_INSN (insn_b); | |
1723 | reorder_insns (insn_b, insn_b, PREV_INSN (if_info.cond_earliest)); | |
bca05d20 RK |
1724 | |
1725 | /* If there was a REG_EQUAL note, delete it since it may have been | |
1726 | true due to this insn being after a jump. */ | |
1727 | if ((note = find_reg_note (insn_b, REG_EQUAL, NULL_RTX)) != 0) | |
1728 | remove_note (insn_b, note); | |
1729 | ||
9ec6d7ab | 1730 | insn_b = NULL_RTX; |
9ec6d7ab | 1731 | } |
cc2999aa JW |
1732 | /* If we have "x = b; if (...) x = a;", and x has side-effects, then |
1733 | x must be executed twice. */ | |
1734 | else if (insn_b && side_effects_p (orig_x)) | |
1735 | return FALSE; | |
1736 | ||
8eeb3159 | 1737 | x = orig_x; |
9ec6d7ab RH |
1738 | goto success; |
1739 | } | |
1740 | ||
1741 | if (noce_try_store_flag (&if_info)) | |
1742 | goto success; | |
05cc23e8 RH |
1743 | if (noce_try_minmax (&if_info)) |
1744 | goto success; | |
1745 | if (noce_try_abs (&if_info)) | |
1746 | goto success; | |
9ec6d7ab RH |
1747 | if (HAVE_conditional_move |
1748 | && noce_try_cmove (&if_info)) | |
1749 | goto success; | |
1750 | if (! HAVE_conditional_execution) | |
1751 | { | |
1752 | if (noce_try_store_flag_constants (&if_info)) | |
1753 | goto success; | |
1754 | if (noce_try_store_flag_inc (&if_info)) | |
1755 | goto success; | |
1756 | if (noce_try_store_flag_mask (&if_info)) | |
1757 | goto success; | |
1758 | if (HAVE_conditional_move | |
1759 | && noce_try_cmove_arith (&if_info)) | |
1760 | goto success; | |
1761 | } | |
1762 | ||
1763 | return FALSE; | |
1764 | ||
1765 | success: | |
1766 | /* The original sets may now be killed. */ | |
1767 | if (insn_a == then_bb->end) | |
1768 | then_bb->end = PREV_INSN (insn_a); | |
1769 | flow_delete_insn (insn_a); | |
1770 | ||
1771 | /* Several special cases here: First, we may have reused insn_b above, | |
1772 | in which case insn_b is now NULL. Second, we want to delete insn_b | |
1773 | if it came from the ELSE block, because follows the now correct | |
1774 | write that appears in the TEST block. However, if we got insn_b from | |
1775 | the TEST block, it may in fact be loading data needed for the comparison. | |
1776 | We'll let life_analysis remove the insn if it's really dead. */ | |
1777 | if (insn_b && else_bb) | |
1778 | { | |
1779 | if (insn_b == else_bb->end) | |
1780 | else_bb->end = PREV_INSN (insn_b); | |
1781 | flow_delete_insn (insn_b); | |
1782 | } | |
1783 | ||
1784 | /* The new insns will have been inserted before cond_earliest. We should | |
c4686982 RH |
1785 | be able to remove the jump with impunity, but the condition itself may |
1786 | have been modified by gcse to be shared across basic blocks. */ | |
1787 | test_bb->end = PREV_INSN (jump); | |
1788 | flow_delete_insn (jump); | |
9ec6d7ab RH |
1789 | |
1790 | /* If we used a temporary, fix it up now. */ | |
1791 | if (orig_x != x) | |
1792 | { | |
1793 | start_sequence (); | |
32ff70d2 | 1794 | noce_emit_move_insn (orig_x, x); |
9ec6d7ab RH |
1795 | insn_b = gen_sequence (); |
1796 | end_sequence (); | |
1797 | ||
c4686982 | 1798 | test_bb->end = emit_insn_after (insn_b, test_bb->end); |
9ec6d7ab RH |
1799 | } |
1800 | ||
1801 | /* Merge the blocks! */ | |
1802 | merge_if_block (test_bb, then_bb, else_bb, join_bb); | |
1803 | ||
1804 | return TRUE; | |
1805 | } | |
1806 | \f | |
1807 | /* Attempt to convert an IF-THEN or IF-THEN-ELSE block into | |
1808 | straight line code. Return true if successful. */ | |
1809 | ||
1810 | static int | |
1811 | process_if_block (test_bb, then_bb, else_bb, join_bb) | |
1812 | basic_block test_bb; /* Basic block test is in */ | |
1813 | basic_block then_bb; /* Basic block for THEN block */ | |
1814 | basic_block else_bb; /* Basic block for ELSE block */ | |
1815 | basic_block join_bb; /* Basic block the join label is in */ | |
1816 | { | |
1817 | if (! reload_completed | |
1818 | && noce_process_if_block (test_bb, then_bb, else_bb, join_bb)) | |
1819 | return TRUE; | |
1820 | ||
1821 | if (HAVE_conditional_execution | |
1822 | && reload_completed | |
1823 | && cond_exec_process_if_block (test_bb, then_bb, else_bb, join_bb)) | |
1824 | return TRUE; | |
1825 | ||
1826 | return FALSE; | |
1827 | } | |
1828 | ||
1829 | /* Merge the blocks and mark for local life update. */ | |
1830 | ||
1831 | static void | |
1832 | merge_if_block (test_bb, then_bb, else_bb, join_bb) | |
1833 | basic_block test_bb; /* Basic block test is in */ | |
1834 | basic_block then_bb; /* Basic block for THEN block */ | |
1835 | basic_block else_bb; /* Basic block for ELSE block */ | |
1836 | basic_block join_bb; /* Basic block the join label is in */ | |
1837 | { | |
1838 | basic_block combo_bb; | |
1839 | ||
1840 | /* All block merging is done into the lower block numbers. */ | |
1841 | ||
1842 | combo_bb = test_bb; | |
1843 | ||
1844 | /* First merge TEST block into THEN block. This is a no-brainer since | |
1845 | the THEN block did not have a code label to begin with. */ | |
1846 | ||
e16d045d | 1847 | if (life_data_ok) |
9ec6d7ab RH |
1848 | COPY_REG_SET (combo_bb->global_live_at_end, then_bb->global_live_at_end); |
1849 | merge_blocks_nomove (combo_bb, then_bb); | |
1850 | num_removed_blocks++; | |
1851 | ||
1852 | /* The ELSE block, if it existed, had a label. That label count | |
1853 | will almost always be zero, but odd things can happen when labels | |
1854 | get their addresses taken. */ | |
1855 | if (else_bb) | |
1856 | { | |
be1bb652 RH |
1857 | merge_blocks_nomove (combo_bb, else_bb); |
1858 | num_removed_blocks++; | |
9ec6d7ab RH |
1859 | } |
1860 | ||
1861 | /* If there was no join block reported, that means it was not adjacent | |
1862 | to the others, and so we cannot merge them. */ | |
1863 | ||
1864 | if (! join_bb) | |
1865 | { | |
1866 | /* The outgoing edge for the current COMBO block should already | |
1867 | be correct. Verify this. */ | |
1868 | if (combo_bb->succ == NULL_EDGE) | |
1869 | abort (); | |
1870 | ||
999c0669 | 1871 | /* There should still be a branch at the end of the THEN or ELSE |
9ec6d7ab | 1872 | blocks taking us to our final destination. */ |
999c0669 | 1873 | if (GET_CODE (combo_bb->end) != JUMP_INSN) |
9ec6d7ab RH |
1874 | abort (); |
1875 | } | |
1876 | ||
be1bb652 RH |
1877 | /* The JOIN block may have had quite a number of other predecessors too. |
1878 | Since we've already merged the TEST, THEN and ELSE blocks, we should | |
1879 | have only one remaining edge from our if-then-else diamond. If there | |
18153f6c RH |
1880 | is more than one remaining edge, it must come from elsewhere. There |
1881 | may be zero incoming edges if the THEN block didn't actually join | |
1882 | back up (as with a call to abort). */ | |
1883 | else if (join_bb->pred == NULL || join_bb->pred->pred_next == NULL) | |
9ec6d7ab RH |
1884 | { |
1885 | /* We can merge the JOIN. */ | |
e16d045d | 1886 | if (life_data_ok) |
9ec6d7ab RH |
1887 | COPY_REG_SET (combo_bb->global_live_at_end, |
1888 | join_bb->global_live_at_end); | |
1889 | merge_blocks_nomove (combo_bb, join_bb); | |
1890 | num_removed_blocks++; | |
1891 | } | |
1892 | else | |
1893 | { | |
1894 | /* We cannot merge the JOIN. */ | |
1895 | ||
1896 | /* The outgoing edge for the current COMBO block should already | |
1897 | be correct. Verify this. */ | |
1898 | if (combo_bb->succ->succ_next != NULL_EDGE | |
1899 | || combo_bb->succ->dest != join_bb) | |
1900 | abort (); | |
1901 | ||
1902 | /* Remove the jump and cruft from the end of the COMBO block. */ | |
1903 | tidy_fallthru_edge (combo_bb->succ, combo_bb, join_bb); | |
1904 | } | |
1905 | ||
1906 | /* Make sure we update life info properly. */ | |
1907 | SET_UPDATE_LIFE (combo_bb); | |
1908 | ||
1909 | num_updated_if_blocks++; | |
1910 | } | |
1911 | \f | |
1912 | /* Find a block ending in a simple IF condition. Return TRUE if | |
1913 | we were able to transform it in some way. */ | |
1914 | ||
1915 | static int | |
1916 | find_if_header (test_bb) | |
1917 | basic_block test_bb; | |
1918 | { | |
1919 | edge then_edge; | |
1920 | edge else_edge; | |
1921 | ||
1922 | /* The kind of block we're looking for has exactly two successors. */ | |
1923 | if ((then_edge = test_bb->succ) == NULL_EDGE | |
1924 | || (else_edge = then_edge->succ_next) == NULL_EDGE | |
1925 | || else_edge->succ_next != NULL_EDGE) | |
1926 | return FALSE; | |
1927 | ||
1928 | /* Neither edge should be abnormal. */ | |
1929 | if ((then_edge->flags & EDGE_COMPLEX) | |
1930 | || (else_edge->flags & EDGE_COMPLEX)) | |
1931 | return FALSE; | |
1932 | ||
1933 | /* The THEN edge is canonically the one that falls through. */ | |
1934 | if (then_edge->flags & EDGE_FALLTHRU) | |
1935 | ; | |
1936 | else if (else_edge->flags & EDGE_FALLTHRU) | |
1937 | { | |
1938 | edge e = else_edge; | |
1939 | else_edge = then_edge; | |
1940 | then_edge = e; | |
1941 | } | |
1942 | else | |
1943 | /* Otherwise this must be a multiway branch of some sort. */ | |
1944 | return FALSE; | |
1945 | ||
1946 | if (find_if_block (test_bb, then_edge, else_edge)) | |
1947 | goto success; | |
999c0669 RH |
1948 | if (HAVE_trap && HAVE_conditional_trap |
1949 | && find_cond_trap (test_bb, then_edge, else_edge)) | |
1950 | goto success; | |
9ec6d7ab RH |
1951 | if (post_dominators |
1952 | && (! HAVE_conditional_execution || reload_completed)) | |
1953 | { | |
1954 | if (find_if_case_1 (test_bb, then_edge, else_edge)) | |
1955 | goto success; | |
1956 | if (find_if_case_2 (test_bb, then_edge, else_edge)) | |
1957 | goto success; | |
1958 | } | |
1959 | ||
1960 | return FALSE; | |
1961 | ||
1962 | success: | |
1963 | if (rtl_dump_file) | |
1964 | fprintf (rtl_dump_file, "Conversion succeeded.\n"); | |
1965 | return TRUE; | |
1966 | } | |
1967 | ||
1968 | /* Determine if a given basic block heads a simple IF-THEN or IF-THEN-ELSE | |
1969 | block. If so, we'll try to convert the insns to not require the branch. | |
1970 | Return TRUE if we were successful at converting the the block. */ | |
1971 | ||
1972 | static int | |
1973 | find_if_block (test_bb, then_edge, else_edge) | |
1974 | basic_block test_bb; | |
1975 | edge then_edge, else_edge; | |
1976 | { | |
1977 | basic_block then_bb = then_edge->dest; | |
1978 | basic_block else_bb = else_edge->dest; | |
1979 | basic_block join_bb = NULL_BLOCK; | |
1980 | edge then_succ = then_bb->succ; | |
1981 | edge else_succ = else_bb->succ; | |
1982 | int next_index; | |
1983 | ||
1984 | /* The THEN block of an IF-THEN combo must have exactly one predecessor. */ | |
1985 | if (then_bb->pred->pred_next != NULL_EDGE) | |
1986 | return FALSE; | |
1987 | ||
18153f6c RH |
1988 | /* The THEN block of an IF-THEN combo must have zero or one successors. */ |
1989 | if (then_succ != NULL_EDGE | |
1990 | && (then_succ->succ_next != NULL_EDGE | |
1991 | || (then_succ->flags & EDGE_COMPLEX))) | |
9ec6d7ab RH |
1992 | return FALSE; |
1993 | ||
18153f6c RH |
1994 | /* If the THEN block has no successors, conditional execution can still |
1995 | make a conditional call. Don't do this unless the ELSE block has | |
f1e42c81 MM |
1996 | only one incoming edge -- the CFG manipulation is too ugly otherwise. |
1997 | Check for the last insn of the THEN block being an indirect jump, which | |
1998 | is listed as not having any successors, but confuses the rest of the CE | |
1999 | code processing. XXX we should fix this in the future. */ | |
18153f6c RH |
2000 | if (then_succ == NULL) |
2001 | { | |
2002 | if (else_bb->pred->pred_next == NULL_EDGE) | |
2003 | { | |
f1e42c81 MM |
2004 | rtx last_insn = then_bb->end; |
2005 | ||
34c9e848 MM |
2006 | while (last_insn |
2007 | && GET_CODE (last_insn) == NOTE | |
2008 | && last_insn != then_bb->head) | |
2009 | last_insn = PREV_INSN (last_insn); | |
f1e42c81 | 2010 | |
34c9e848 MM |
2011 | if (last_insn |
2012 | && GET_CODE (last_insn) == JUMP_INSN | |
f1e42c81 MM |
2013 | && ! simplejump_p (last_insn)) |
2014 | return FALSE; | |
2015 | ||
18153f6c RH |
2016 | join_bb = else_bb; |
2017 | else_bb = NULL_BLOCK; | |
2018 | } | |
2019 | else | |
2020 | return FALSE; | |
2021 | } | |
2022 | ||
9ec6d7ab RH |
2023 | /* If the THEN block's successor is the other edge out of the TEST block, |
2024 | then we have an IF-THEN combo without an ELSE. */ | |
18153f6c | 2025 | else if (then_succ->dest == else_bb) |
9ec6d7ab RH |
2026 | { |
2027 | join_bb = else_bb; | |
2028 | else_bb = NULL_BLOCK; | |
2029 | } | |
2030 | ||
2031 | /* If the THEN and ELSE block meet in a subsequent block, and the ELSE | |
2032 | has exactly one predecessor and one successor, and the outgoing edge | |
2033 | is not complex, then we have an IF-THEN-ELSE combo. */ | |
2034 | else if (else_succ != NULL_EDGE | |
2035 | && then_succ->dest == else_succ->dest | |
2036 | && else_bb->pred->pred_next == NULL_EDGE | |
2037 | && else_succ->succ_next == NULL_EDGE | |
2038 | && ! (else_succ->flags & EDGE_COMPLEX)) | |
2039 | join_bb = else_succ->dest; | |
2040 | ||
2041 | /* Otherwise it is not an IF-THEN or IF-THEN-ELSE combination. */ | |
2042 | else | |
2043 | return FALSE; | |
2044 | ||
2045 | num_possible_if_blocks++; | |
2046 | ||
2047 | if (rtl_dump_file) | |
2048 | { | |
2049 | if (else_bb) | |
2050 | fprintf (rtl_dump_file, | |
2051 | "\nIF-THEN-ELSE block found, start %d, then %d, else %d, join %d\n", | |
2052 | test_bb->index, then_bb->index, else_bb->index, | |
2053 | join_bb->index); | |
2054 | else | |
2055 | fprintf (rtl_dump_file, | |
2056 | "\nIF-THEN block found, start %d, then %d, join %d\n", | |
2057 | test_bb->index, then_bb->index, join_bb->index); | |
2058 | } | |
2059 | ||
2060 | /* Make sure IF, THEN, and ELSE, blocks are adjacent. Actually, we | |
2061 | get the first condition for free, since we've already asserted that | |
2062 | there's a fallthru edge from IF to THEN. */ | |
52a11cbf | 2063 | /* ??? As an enhancement, move the ELSE block. Have to deal with |
9ec6d7ab RH |
2064 | BLOCK notes, if by no other means than aborting the merge if they |
2065 | exist. Sticky enough I don't want to think about it now. */ | |
2066 | next_index = then_bb->index; | |
2067 | if (else_bb && ++next_index != else_bb->index) | |
2068 | return FALSE; | |
2069 | if (++next_index != join_bb->index) | |
2070 | { | |
2071 | if (else_bb) | |
2072 | join_bb = NULL; | |
2073 | else | |
2074 | return FALSE; | |
2075 | } | |
2076 | ||
2077 | /* Do the real work. */ | |
2078 | return process_if_block (test_bb, then_bb, else_bb, join_bb); | |
2079 | } | |
2080 | ||
999c0669 RH |
2081 | /* Convert a branch over a trap, or a branch to a trap, |
2082 | into a conditional trap. */ | |
2083 | ||
2084 | static int | |
2085 | find_cond_trap (test_bb, then_edge, else_edge) | |
2086 | basic_block test_bb; | |
2087 | edge then_edge, else_edge; | |
2088 | { | |
2089 | basic_block then_bb, else_bb, join_bb, trap_bb; | |
2090 | rtx trap, jump, cond, cond_earliest, seq; | |
2091 | enum rtx_code code; | |
2092 | ||
2093 | then_bb = then_edge->dest; | |
2094 | else_bb = else_edge->dest; | |
2095 | join_bb = NULL; | |
2096 | ||
2097 | /* Locate the block with the trap instruction. */ | |
2098 | /* ??? While we look for no successors, we really ought to allow | |
2099 | EH successors. Need to fix merge_if_block for that to work. */ | |
2100 | /* ??? We can't currently handle merging the blocks if they are not | |
2101 | already adjacent. Prevent losage in merge_if_block by detecting | |
2102 | this now. */ | |
2103 | if (then_bb->succ == NULL) | |
2104 | { | |
2105 | trap_bb = then_bb; | |
2106 | if (else_bb->index != then_bb->index + 1) | |
2107 | return FALSE; | |
2108 | join_bb = else_bb; | |
2109 | else_bb = NULL; | |
2110 | } | |
2111 | else if (else_bb->succ == NULL) | |
2112 | { | |
2113 | trap_bb = else_bb; | |
2114 | if (else_bb->index != then_bb->index + 1) | |
2115 | else_bb = NULL; | |
2116 | else if (then_bb->succ | |
2117 | && ! then_bb->succ->succ_next | |
2118 | && ! (then_bb->succ->flags & EDGE_COMPLEX) | |
2119 | && then_bb->succ->dest->index == else_bb->index + 1) | |
2120 | join_bb = then_bb->succ->dest; | |
2121 | } | |
2122 | else | |
2123 | return FALSE; | |
2124 | ||
35cbdf6f RH |
2125 | /* Don't confuse a conditional return with something we want to |
2126 | optimize here. */ | |
2127 | if (trap_bb == EXIT_BLOCK_PTR) | |
2128 | return FALSE; | |
2129 | ||
999c0669 RH |
2130 | /* The only instruction in the THEN block must be the trap. */ |
2131 | trap = first_active_insn (trap_bb); | |
2132 | if (! (trap == trap_bb->end | |
2133 | && GET_CODE (PATTERN (trap)) == TRAP_IF | |
2134 | && TRAP_CONDITION (PATTERN (trap)) == const_true_rtx)) | |
2135 | return FALSE; | |
2136 | ||
2137 | if (rtl_dump_file) | |
2138 | { | |
2139 | if (trap_bb == then_bb) | |
2140 | fprintf (rtl_dump_file, | |
2141 | "\nTRAP-IF block found, start %d, trap %d", | |
2142 | test_bb->index, then_bb->index); | |
2143 | else | |
2144 | fprintf (rtl_dump_file, | |
2145 | "\nTRAP-IF block found, start %d, then %d, trap %d", | |
2146 | test_bb->index, then_bb->index, trap_bb->index); | |
2147 | if (join_bb) | |
2148 | fprintf (rtl_dump_file, ", join %d\n", join_bb->index); | |
2149 | else | |
2150 | fputc ('\n', rtl_dump_file); | |
2151 | } | |
2152 | ||
2153 | /* If this is not a standard conditional jump, we can't parse it. */ | |
2154 | jump = test_bb->end; | |
2155 | cond = noce_get_condition (jump, &cond_earliest); | |
2156 | if (! cond) | |
2157 | return FALSE; | |
2158 | ||
2159 | /* If the conditional jump is more than just a conditional jump, | |
2160 | then we can not do if-conversion on this block. */ | |
2161 | if (! onlyjump_p (jump)) | |
2162 | return FALSE; | |
2163 | ||
2164 | /* We must be comparing objects whose modes imply the size. */ | |
2165 | if (GET_MODE (XEXP (cond, 0)) == BLKmode) | |
2166 | return FALSE; | |
2167 | ||
2168 | /* Reverse the comparison code, if necessary. */ | |
2169 | code = GET_CODE (cond); | |
2170 | if (then_bb == trap_bb) | |
2171 | { | |
2172 | code = reversed_comparison_code (cond, jump); | |
2173 | if (code == UNKNOWN) | |
2174 | return FALSE; | |
2175 | } | |
2176 | ||
2177 | /* Attempt to generate the conditional trap. */ | |
2178 | seq = gen_cond_trap (code, XEXP (cond, 0), XEXP (cond, 1), | |
2179 | TRAP_CODE (PATTERN (trap))); | |
2180 | if (seq == NULL) | |
2181 | return FALSE; | |
2182 | ||
2183 | /* Emit the new insns before cond_earliest; delete the old jump | |
2184 | and trap insns. */ | |
2185 | ||
2186 | emit_insn_before (seq, cond_earliest); | |
2187 | ||
2188 | test_bb->end = PREV_INSN (jump); | |
2189 | flow_delete_insn (jump); | |
2190 | ||
2191 | trap_bb->end = PREV_INSN (trap); | |
2192 | flow_delete_insn (trap); | |
2193 | ||
2194 | /* Merge the blocks! */ | |
2195 | if (trap_bb != then_bb && ! else_bb) | |
2196 | { | |
2197 | flow_delete_block (trap_bb); | |
2198 | num_removed_blocks++; | |
2199 | } | |
2200 | merge_if_block (test_bb, then_bb, else_bb, join_bb); | |
2201 | ||
2202 | return TRUE; | |
2203 | } | |
2204 | ||
9ec6d7ab RH |
2205 | /* Look for IF-THEN-ELSE cases in which one of THEN or ELSE is |
2206 | transformable, but not necessarily the other. There need be no | |
2207 | JOIN block. | |
2208 | ||
2209 | Return TRUE if we were successful at converting the the block. | |
2210 | ||
2211 | Cases we'd like to look at: | |
2212 | ||
2213 | (1) | |
2214 | if (test) goto over; // x not live | |
2215 | x = a; | |
2216 | goto label; | |
2217 | over: | |
2218 | ||
2219 | becomes | |
2220 | ||
2221 | x = a; | |
2222 | if (! test) goto label; | |
2223 | ||
2224 | (2) | |
2225 | if (test) goto E; // x not live | |
2226 | x = big(); | |
2227 | goto L; | |
2228 | E: | |
2229 | x = b; | |
2230 | goto M; | |
2231 | ||
2232 | becomes | |
2233 | ||
2234 | x = b; | |
2235 | if (test) goto M; | |
2236 | x = big(); | |
2237 | goto L; | |
2238 | ||
2239 | (3) // This one's really only interesting for targets that can do | |
2240 | // multiway branching, e.g. IA-64 BBB bundles. For other targets | |
2241 | // it results in multiple branches on a cache line, which often | |
2242 | // does not sit well with predictors. | |
2243 | ||
2244 | if (test1) goto E; // predicted not taken | |
2245 | x = a; | |
2246 | if (test2) goto F; | |
2247 | ... | |
2248 | E: | |
2249 | x = b; | |
2250 | J: | |
2251 | ||
2252 | becomes | |
2253 | ||
2254 | x = a; | |
2255 | if (test1) goto E; | |
2256 | if (test2) goto F; | |
2257 | ||
2258 | Notes: | |
2259 | ||
2260 | (A) Don't do (2) if the branch is predicted against the block we're | |
2261 | eliminating. Do it anyway if we can eliminate a branch; this requires | |
2262 | that the sole successor of the eliminated block postdominate the other | |
2263 | side of the if. | |
2264 | ||
2265 | (B) With CE, on (3) we can steal from both sides of the if, creating | |
2266 | ||
2267 | if (test1) x = a; | |
2268 | if (!test1) x = b; | |
2269 | if (test1) goto J; | |
2270 | if (test2) goto F; | |
2271 | ... | |
2272 | J: | |
2273 | ||
2274 | Again, this is most useful if J postdominates. | |
2275 | ||
2276 | (C) CE substitutes for helpful life information. | |
2277 | ||
2278 | (D) These heuristics need a lot of work. */ | |
2279 | ||
2280 | /* Tests for case 1 above. */ | |
2281 | ||
2282 | static int | |
2283 | find_if_case_1 (test_bb, then_edge, else_edge) | |
2284 | basic_block test_bb; | |
2285 | edge then_edge, else_edge; | |
2286 | { | |
2287 | basic_block then_bb = then_edge->dest; | |
6b24c259 | 2288 | basic_block else_bb = else_edge->dest, new_bb; |
9ec6d7ab | 2289 | edge then_succ = then_bb->succ; |
9ec6d7ab RH |
2290 | |
2291 | /* THEN has one successor. */ | |
2292 | if (!then_succ || then_succ->succ_next != NULL) | |
2293 | return FALSE; | |
2294 | ||
2295 | /* THEN does not fall through, but is not strange either. */ | |
2296 | if (then_succ->flags & (EDGE_COMPLEX | EDGE_FALLTHRU)) | |
2297 | return FALSE; | |
2298 | ||
2299 | /* THEN has one predecessor. */ | |
2300 | if (then_bb->pred->pred_next != NULL) | |
2301 | return FALSE; | |
2302 | ||
6b24c259 JH |
2303 | /* THEN must do something. */ |
2304 | if (forwarder_block_p (then_bb)) | |
9ec6d7ab RH |
2305 | return FALSE; |
2306 | ||
2307 | num_possible_if_blocks++; | |
2308 | if (rtl_dump_file) | |
2309 | fprintf (rtl_dump_file, | |
2310 | "\nIF-CASE-1 found, start %d, then %d\n", | |
2311 | test_bb->index, then_bb->index); | |
2312 | ||
2313 | /* THEN is small. */ | |
2314 | if (count_bb_insns (then_bb) > BRANCH_COST) | |
2315 | return FALSE; | |
2316 | ||
9ec6d7ab | 2317 | /* Registers set are dead, or are predicable. */ |
6b24c259 JH |
2318 | if (! dead_or_predicable (test_bb, then_bb, else_bb, |
2319 | then_bb->succ->dest, 1)) | |
9ec6d7ab RH |
2320 | return FALSE; |
2321 | ||
2322 | /* Conversion went ok, including moving the insns and fixing up the | |
2323 | jump. Adjust the CFG to match. */ | |
2324 | ||
2325 | SET_UPDATE_LIFE (test_bb); | |
2326 | bitmap_operation (test_bb->global_live_at_end, | |
2327 | else_bb->global_live_at_start, | |
2328 | then_bb->global_live_at_end, BITMAP_IOR); | |
2329 | ||
6b24c259 JH |
2330 | new_bb = redirect_edge_and_branch_force (FALLTHRU_EDGE (test_bb), else_bb); |
2331 | /* Make rest of code believe that the newly created block is the THEN_BB | |
2332 | block we are going to remove. */ | |
2333 | if (new_bb) | |
2334 | { | |
2335 | new_bb->aux = then_bb->aux; | |
2336 | SET_UPDATE_LIFE (then_bb); | |
2337 | } | |
9ec6d7ab | 2338 | flow_delete_block (then_bb); |
6b24c259 JH |
2339 | /* We've possibly created jump to next insn, cleanup_cfg will solve that |
2340 | later. */ | |
9ec6d7ab RH |
2341 | |
2342 | num_removed_blocks++; | |
2343 | num_updated_if_blocks++; | |
2344 | ||
2345 | return TRUE; | |
2346 | } | |
2347 | ||
2348 | /* Test for case 2 above. */ | |
2349 | ||
2350 | static int | |
2351 | find_if_case_2 (test_bb, then_edge, else_edge) | |
2352 | basic_block test_bb; | |
2353 | edge then_edge, else_edge; | |
2354 | { | |
2355 | basic_block then_bb = then_edge->dest; | |
2356 | basic_block else_bb = else_edge->dest; | |
2357 | edge else_succ = else_bb->succ; | |
6b24c259 | 2358 | rtx note; |
9ec6d7ab RH |
2359 | |
2360 | /* ELSE has one successor. */ | |
2361 | if (!else_succ || else_succ->succ_next != NULL) | |
2362 | return FALSE; | |
2363 | ||
2364 | /* ELSE outgoing edge is not complex. */ | |
2365 | if (else_succ->flags & EDGE_COMPLEX) | |
2366 | return FALSE; | |
2367 | ||
2368 | /* ELSE has one predecessor. */ | |
2369 | if (else_bb->pred->pred_next != NULL) | |
2370 | return FALSE; | |
2371 | ||
b6cfd264 RH |
2372 | /* THEN is not EXIT. */ |
2373 | if (then_bb->index < 0) | |
2374 | return FALSE; | |
2375 | ||
9ec6d7ab RH |
2376 | /* ELSE is predicted or SUCC(ELSE) postdominates THEN. */ |
2377 | note = find_reg_note (test_bb->end, REG_BR_PROB, NULL_RTX); | |
2378 | if (note && INTVAL (XEXP (note, 0)) >= REG_BR_PROB_BASE / 2) | |
2379 | ; | |
2380 | else if (else_succ->dest->index < 0 | |
b6cfd264 RH |
2381 | || TEST_BIT (post_dominators[ORIG_INDEX (then_bb)], |
2382 | ORIG_INDEX (else_succ->dest))) | |
9ec6d7ab RH |
2383 | ; |
2384 | else | |
2385 | return FALSE; | |
2386 | ||
2387 | num_possible_if_blocks++; | |
2388 | if (rtl_dump_file) | |
2389 | fprintf (rtl_dump_file, | |
2390 | "\nIF-CASE-2 found, start %d, else %d\n", | |
2391 | test_bb->index, else_bb->index); | |
2392 | ||
2393 | /* ELSE is small. */ | |
2394 | if (count_bb_insns (then_bb) > BRANCH_COST) | |
2395 | return FALSE; | |
2396 | ||
9ec6d7ab | 2397 | /* Registers set are dead, or are predicable. */ |
6b24c259 | 2398 | if (! dead_or_predicable (test_bb, else_bb, then_bb, else_succ->dest, 0)) |
9ec6d7ab RH |
2399 | return FALSE; |
2400 | ||
2401 | /* Conversion went ok, including moving the insns and fixing up the | |
2402 | jump. Adjust the CFG to match. */ | |
2403 | ||
2404 | SET_UPDATE_LIFE (test_bb); | |
2405 | bitmap_operation (test_bb->global_live_at_end, | |
2406 | then_bb->global_live_at_start, | |
2407 | else_bb->global_live_at_end, BITMAP_IOR); | |
2408 | ||
9ec6d7ab RH |
2409 | flow_delete_block (else_bb); |
2410 | ||
2411 | num_removed_blocks++; | |
2412 | num_updated_if_blocks++; | |
2413 | ||
2414 | /* ??? We may now fallthru from one of THEN's successors into a join | |
2415 | block. Rerun cleanup_cfg? Examine things manually? Wait? */ | |
2416 | ||
2417 | return TRUE; | |
2418 | } | |
2419 | ||
2420 | /* A subroutine of dead_or_predicable called through for_each_rtx. | |
2421 | Return 1 if a memory is found. */ | |
2422 | ||
2423 | static int | |
2424 | find_memory (px, data) | |
2425 | rtx *px; | |
2426 | void *data ATTRIBUTE_UNUSED; | |
2427 | { | |
2428 | return GET_CODE (*px) == MEM; | |
2429 | } | |
2430 | ||
2431 | /* Used by the code above to perform the actual rtl transformations. | |
2432 | Return TRUE if successful. | |
2433 | ||
2434 | TEST_BB is the block containing the conditional branch. MERGE_BB | |
2435 | is the block containing the code to manipulate. NEW_DEST is the | |
2436 | label TEST_BB should be branching to after the conversion. | |
2437 | REVERSEP is true if the sense of the branch should be reversed. */ | |
2438 | ||
2439 | static int | |
2440 | dead_or_predicable (test_bb, merge_bb, other_bb, new_dest, reversep) | |
2441 | basic_block test_bb, merge_bb, other_bb; | |
6b24c259 | 2442 | basic_block new_dest; |
9ec6d7ab RH |
2443 | int reversep; |
2444 | { | |
6b24c259 | 2445 | rtx head, end, jump, earliest, old_dest, new_label; |
9ec6d7ab RH |
2446 | |
2447 | jump = test_bb->end; | |
2448 | ||
2449 | /* Find the extent of the real code in the merge block. */ | |
2450 | head = merge_bb->head; | |
2451 | end = merge_bb->end; | |
2452 | ||
2453 | if (GET_CODE (head) == CODE_LABEL) | |
2454 | head = NEXT_INSN (head); | |
2455 | if (GET_CODE (head) == NOTE) | |
2456 | { | |
2457 | if (head == end) | |
2458 | { | |
2459 | head = end = NULL_RTX; | |
2460 | goto no_body; | |
2461 | } | |
2462 | head = NEXT_INSN (head); | |
2463 | } | |
2464 | ||
2465 | if (GET_CODE (end) == JUMP_INSN) | |
2466 | { | |
2467 | if (head == end) | |
2468 | { | |
2469 | head = end = NULL_RTX; | |
2470 | goto no_body; | |
2471 | } | |
2472 | end = PREV_INSN (end); | |
2473 | } | |
2474 | ||
89d237bf MM |
2475 | /* Disable handling dead code by conditional execution if the machine needs |
2476 | to do anything funny with the tests, etc. */ | |
2477 | #ifndef IFCVT_MODIFY_TESTS | |
9ec6d7ab RH |
2478 | if (HAVE_conditional_execution) |
2479 | { | |
2480 | /* In the conditional execution case, we have things easy. We know | |
2481 | the condition is reversable. We don't have to check life info, | |
2482 | becase we're going to conditionally execute the code anyway. | |
2483 | All that's left is making sure the insns involved can actually | |
2484 | be predicated. */ | |
2485 | ||
2ff00dd4 | 2486 | rtx cond, prob_val; |
9ec6d7ab RH |
2487 | |
2488 | cond = cond_exec_get_condition (jump); | |
b1b0700d RH |
2489 | if (! cond) |
2490 | return FALSE; | |
2ff00dd4 RH |
2491 | |
2492 | prob_val = find_reg_note (jump, REG_BR_PROB, NULL_RTX); | |
2493 | if (prob_val) | |
2494 | prob_val = XEXP (prob_val, 0); | |
2495 | ||
9ec6d7ab | 2496 | if (reversep) |
2ff00dd4 | 2497 | { |
b1b0700d RH |
2498 | enum rtx_code rev = reversed_comparison_code (cond, jump); |
2499 | if (rev == UNKNOWN) | |
037e3d1f | 2500 | return FALSE; |
b1b0700d | 2501 | cond = gen_rtx_fmt_ee (rev, GET_MODE (cond), XEXP (cond, 0), |
2ff00dd4 RH |
2502 | XEXP (cond, 1)); |
2503 | if (prob_val) | |
2504 | prob_val = GEN_INT (REG_BR_PROB_BASE - INTVAL (prob_val)); | |
2505 | } | |
9ec6d7ab | 2506 | |
2ff00dd4 | 2507 | if (! cond_exec_process_insns (head, end, cond, prob_val, 0)) |
9ec6d7ab RH |
2508 | goto cancel; |
2509 | ||
2510 | earliest = jump; | |
2511 | } | |
2512 | else | |
89d237bf | 2513 | #endif |
9ec6d7ab RH |
2514 | { |
2515 | /* In the non-conditional execution case, we have to verify that there | |
2516 | are no trapping operations, no calls, no references to memory, and | |
2517 | that any registers modified are dead at the branch site. */ | |
2518 | ||
2519 | rtx insn, cond, prev; | |
2520 | regset_head merge_set_head, tmp_head, test_live_head, test_set_head; | |
2521 | regset merge_set, tmp, test_live, test_set; | |
2522 | struct propagate_block_info *pbi; | |
2523 | int i, fail = 0; | |
2524 | ||
2525 | /* Check for no calls or trapping operations. */ | |
2526 | for (insn = head; ; insn = NEXT_INSN (insn)) | |
2527 | { | |
2528 | if (GET_CODE (insn) == CALL_INSN) | |
2529 | return FALSE; | |
2530 | if (INSN_P (insn)) | |
2531 | { | |
2532 | if (may_trap_p (PATTERN (insn))) | |
2533 | return FALSE; | |
2534 | ||
2535 | /* ??? Even non-trapping memories such as stack frame | |
2536 | references must be avoided. For stores, we collect | |
2537 | no lifetime info; for reads, we'd have to assert | |
2538 | true_dependance false against every store in the | |
2539 | TEST range. */ | |
2540 | if (for_each_rtx (&PATTERN (insn), find_memory, NULL)) | |
2541 | return FALSE; | |
2542 | } | |
2543 | if (insn == end) | |
2544 | break; | |
2545 | } | |
2546 | ||
7f1c097d | 2547 | if (! any_condjump_p (jump)) |
9ec6d7ab RH |
2548 | return FALSE; |
2549 | ||
2550 | /* Find the extent of the conditional. */ | |
2551 | cond = noce_get_condition (jump, &earliest); | |
2552 | if (! cond) | |
2553 | return FALSE; | |
2554 | ||
2555 | /* Collect: | |
2556 | MERGE_SET = set of registers set in MERGE_BB | |
2557 | TEST_LIVE = set of registers live at EARLIEST | |
2558 | TEST_SET = set of registers set between EARLIEST and the | |
2559 | end of the block. */ | |
2560 | ||
2561 | tmp = INITIALIZE_REG_SET (tmp_head); | |
2562 | merge_set = INITIALIZE_REG_SET (merge_set_head); | |
2563 | test_live = INITIALIZE_REG_SET (test_live_head); | |
2564 | test_set = INITIALIZE_REG_SET (test_set_head); | |
2565 | ||
2566 | /* ??? bb->local_set is only valid during calculate_global_regs_live, | |
2567 | so we must recompute usage for MERGE_BB. Not so bad, I suppose, | |
2568 | since we've already asserted that MERGE_BB is small. */ | |
7dfc0fbe | 2569 | propagate_block (merge_bb, tmp, merge_set, merge_set, 0); |
9ec6d7ab RH |
2570 | |
2571 | /* For small register class machines, don't lengthen lifetimes of | |
2572 | hard registers before reload. */ | |
2573 | if (SMALL_REGISTER_CLASSES && ! reload_completed) | |
2574 | { | |
2575 | EXECUTE_IF_SET_IN_BITMAP | |
2576 | (merge_set, 0, i, | |
2577 | { | |
2578 | if (i < FIRST_PSEUDO_REGISTER | |
2579 | && ! fixed_regs[i] | |
2580 | && ! global_regs[i]) | |
2581 | fail = 1; | |
2582 | }); | |
2583 | } | |
2584 | ||
2585 | /* For TEST, we're interested in a range of insns, not a whole block. | |
2586 | Moreover, we're interested in the insns live from OTHER_BB. */ | |
2587 | ||
2588 | COPY_REG_SET (test_live, other_bb->global_live_at_start); | |
7dfc0fbe BS |
2589 | pbi = init_propagate_block_info (test_bb, test_live, test_set, test_set, |
2590 | 0); | |
9ec6d7ab RH |
2591 | |
2592 | for (insn = jump; ; insn = prev) | |
2593 | { | |
2594 | prev = propagate_one_insn (pbi, insn); | |
2595 | if (insn == earliest) | |
2596 | break; | |
2597 | } | |
2598 | ||
2599 | free_propagate_block_info (pbi); | |
2600 | ||
2601 | /* We can perform the transformation if | |
2602 | MERGE_SET & (TEST_SET | TEST_LIVE) | |
2603 | and | |
2604 | TEST_SET & merge_bb->global_live_at_start | |
2605 | are empty. */ | |
2606 | ||
2607 | bitmap_operation (tmp, test_set, test_live, BITMAP_IOR); | |
2608 | bitmap_operation (tmp, tmp, merge_set, BITMAP_AND); | |
2609 | EXECUTE_IF_SET_IN_BITMAP(tmp, 0, i, fail = 1); | |
2610 | ||
2611 | bitmap_operation (tmp, test_set, merge_bb->global_live_at_start, | |
2612 | BITMAP_AND); | |
2613 | EXECUTE_IF_SET_IN_BITMAP(tmp, 0, i, fail = 1); | |
2614 | ||
2615 | FREE_REG_SET (tmp); | |
2616 | FREE_REG_SET (merge_set); | |
2617 | FREE_REG_SET (test_live); | |
2618 | FREE_REG_SET (test_set); | |
2619 | ||
2620 | if (fail) | |
2621 | return FALSE; | |
2622 | } | |
2623 | ||
2624 | no_body: | |
2625 | /* We don't want to use normal invert_jump or redirect_jump because | |
2626 | we don't want to delete_insn called. Also, we want to do our own | |
2627 | change group management. */ | |
2628 | ||
2629 | old_dest = JUMP_LABEL (jump); | |
6b24c259 | 2630 | new_label = block_label (new_dest); |
9ec6d7ab | 2631 | if (reversep |
6b24c259 JH |
2632 | ? ! invert_jump_1 (jump, new_label) |
2633 | : ! redirect_jump_1 (jump, new_label)) | |
9ec6d7ab RH |
2634 | goto cancel; |
2635 | ||
2636 | if (! apply_change_group ()) | |
2637 | return FALSE; | |
2638 | ||
2639 | if (old_dest) | |
2640 | LABEL_NUSES (old_dest) -= 1; | |
6b24c259 JH |
2641 | if (new_label) |
2642 | LABEL_NUSES (new_label) += 1; | |
2643 | JUMP_LABEL (jump) = new_label; | |
9ec6d7ab RH |
2644 | |
2645 | if (reversep) | |
4db384c9 | 2646 | invert_br_probabilities (jump); |
9ec6d7ab | 2647 | |
6b24c259 JH |
2648 | redirect_edge_succ (BRANCH_EDGE (test_bb), new_dest); |
2649 | if (reversep) | |
2650 | { | |
2651 | gcov_type count, probability; | |
2652 | count = BRANCH_EDGE (test_bb)->count; | |
2653 | BRANCH_EDGE (test_bb)->count = FALLTHRU_EDGE (test_bb)->count; | |
2654 | FALLTHRU_EDGE (test_bb)->count = count; | |
2655 | probability = BRANCH_EDGE (test_bb)->probability; | |
2656 | BRANCH_EDGE (test_bb)->probability = FALLTHRU_EDGE (test_bb)->probability; | |
2657 | FALLTHRU_EDGE (test_bb)->probability = probability; | |
2658 | } | |
2659 | ||
9ec6d7ab | 2660 | /* Move the insns out of MERGE_BB to before the branch. */ |
9ec6d7ab RH |
2661 | if (head != NULL) |
2662 | { | |
15ac7707 RH |
2663 | if (end == merge_bb->end) |
2664 | merge_bb->end = PREV_INSN (head); | |
2665 | ||
9ec6d7ab | 2666 | head = squeeze_notes (head, end); |
0ca4f243 RH |
2667 | if (GET_CODE (end) == NOTE |
2668 | && (NOTE_LINE_NUMBER (end) == NOTE_INSN_BLOCK_END | |
2669 | || NOTE_LINE_NUMBER (end) == NOTE_INSN_BLOCK_BEG | |
2670 | || NOTE_LINE_NUMBER (end) == NOTE_INSN_LOOP_BEG | |
2671 | || NOTE_LINE_NUMBER (end) == NOTE_INSN_LOOP_END | |
2672 | || NOTE_LINE_NUMBER (end) == NOTE_INSN_LOOP_CONT | |
2673 | || NOTE_LINE_NUMBER (end) == NOTE_INSN_LOOP_VTOP)) | |
2674 | { | |
2675 | if (head == end) | |
2676 | return TRUE; | |
2677 | end = PREV_INSN (end); | |
2678 | } | |
2679 | ||
9ec6d7ab RH |
2680 | reorder_insns (head, end, PREV_INSN (earliest)); |
2681 | } | |
2682 | return TRUE; | |
2683 | ||
2684 | cancel: | |
2685 | cancel_changes (0); | |
2686 | return FALSE; | |
2687 | } | |
2688 | \f | |
2689 | /* Main entry point for all if-conversion. */ | |
2690 | ||
2691 | void | |
e16d045d RH |
2692 | if_convert (x_life_data_ok) |
2693 | int x_life_data_ok; | |
9ec6d7ab RH |
2694 | { |
2695 | int block_num; | |
2696 | ||
2697 | num_possible_if_blocks = 0; | |
2698 | num_updated_if_blocks = 0; | |
2699 | num_removed_blocks = 0; | |
e16d045d | 2700 | life_data_ok = (x_life_data_ok != 0); |
9ec6d7ab RH |
2701 | |
2702 | /* Free up basic_block_for_insn so that we don't have to keep it | |
2703 | up to date, either here or in merge_blocks_nomove. */ | |
2704 | free_basic_block_vars (1); | |
2705 | ||
2706 | /* Compute postdominators if we think we'll use them. */ | |
2707 | post_dominators = NULL; | |
2708 | if (HAVE_conditional_execution || life_data_ok) | |
2709 | { | |
2710 | post_dominators = sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks); | |
f8032688 | 2711 | calculate_dominance_info (NULL, post_dominators, CDI_POST_DOMINATORS); |
9ec6d7ab RH |
2712 | } |
2713 | ||
2714 | /* Record initial block numbers. */ | |
2715 | for (block_num = 0; block_num < n_basic_blocks; block_num++) | |
2716 | SET_ORIG_INDEX (BASIC_BLOCK (block_num), block_num); | |
2717 | ||
2718 | /* Go through each of the basic blocks looking for things to convert. */ | |
2719 | for (block_num = 0; block_num < n_basic_blocks; ) | |
2720 | { | |
2721 | basic_block bb = BASIC_BLOCK (block_num); | |
2722 | if (find_if_header (bb)) | |
2723 | block_num = bb->index; | |
2724 | else | |
2725 | block_num++; | |
2726 | } | |
2727 | ||
8701a6a4 PDM |
2728 | if (post_dominators) |
2729 | sbitmap_vector_free (post_dominators); | |
9ec6d7ab RH |
2730 | |
2731 | if (rtl_dump_file) | |
2732 | fflush (rtl_dump_file); | |
2733 | ||
2734 | /* Rebuild basic_block_for_insn for update_life_info and for gcse. */ | |
2735 | compute_bb_for_insn (get_max_uid ()); | |
2736 | ||
2737 | /* Rebuild life info for basic blocks that require it. */ | |
2738 | if (num_removed_blocks && life_data_ok) | |
2739 | { | |
2740 | sbitmap update_life_blocks = sbitmap_alloc (n_basic_blocks); | |
2741 | sbitmap_zero (update_life_blocks); | |
2742 | ||
2743 | /* If we allocated new pseudos, we must resize the array for sched1. */ | |
2744 | if (max_regno < max_reg_num ()) | |
2745 | { | |
2746 | max_regno = max_reg_num (); | |
2747 | allocate_reg_info (max_regno, FALSE, FALSE); | |
2748 | } | |
2749 | ||
2750 | for (block_num = 0; block_num < n_basic_blocks; block_num++) | |
2751 | if (UPDATE_LIFE (BASIC_BLOCK (block_num))) | |
2752 | SET_BIT (update_life_blocks, block_num); | |
2753 | ||
2754 | count_or_remove_death_notes (update_life_blocks, 1); | |
5896bebb JJ |
2755 | /* ??? See about adding a mode that verifies that the initial |
2756 | set of blocks don't let registers come live. */ | |
2757 | update_life_info (update_life_blocks, UPDATE_LIFE_GLOBAL, | |
13462862 AO |
2758 | PROP_DEATH_NOTES | PROP_SCAN_DEAD_CODE |
2759 | | PROP_KILL_DEAD_CODE); | |
9ec6d7ab RH |
2760 | |
2761 | sbitmap_free (update_life_blocks); | |
2762 | } | |
2763 | ||
2764 | /* Write the final stats. */ | |
2765 | if (rtl_dump_file && num_possible_if_blocks > 0) | |
2766 | { | |
2767 | fprintf (rtl_dump_file, | |
2768 | "\n%d possible IF blocks searched.\n", | |
2769 | num_possible_if_blocks); | |
2770 | fprintf (rtl_dump_file, | |
2771 | "%d IF blocks converted.\n", | |
2772 | num_updated_if_blocks); | |
2773 | fprintf (rtl_dump_file, | |
2774 | "%d basic blocks deleted.\n\n\n", | |
2775 | num_removed_blocks); | |
2776 | } | |
2777 | ||
7aa88bcf | 2778 | #ifdef ENABLE_CHECKING |
dcfa721d | 2779 | verify_flow_info (); |
7aa88bcf | 2780 | #endif |
9ec6d7ab | 2781 | } |