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15a63be1 | 1 | /* Optimize jump instructions, for GNU compiler. |
c85f7c16 | 2 | Copyright (C) 1987, 88, 89, 91-97, 1998 Free Software Foundation, Inc. |
15a63be1 RK |
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 | |
a35311b0 RK |
18 | the Free Software Foundation, 59 Temple Place - Suite 330, |
19 | Boston, MA 02111-1307, USA. */ | |
15a63be1 RK |
20 | |
21 | ||
22 | /* This is the jump-optimization pass of the compiler. | |
23 | It is run two or three times: once before cse, sometimes once after cse, | |
24 | and once after reload (before final). | |
25 | ||
26 | jump_optimize deletes unreachable code and labels that are not used. | |
27 | It also deletes jumps that jump to the following insn, | |
28 | and simplifies jumps around unconditional jumps and jumps | |
29 | to unconditional jumps. | |
30 | ||
31 | Each CODE_LABEL has a count of the times it is used | |
32 | stored in the LABEL_NUSES internal field, and each JUMP_INSN | |
33 | has one label that it refers to stored in the | |
34 | JUMP_LABEL internal field. With this we can detect labels that | |
35 | become unused because of the deletion of all the jumps that | |
36 | formerly used them. The JUMP_LABEL info is sometimes looked | |
37 | at by later passes. | |
38 | ||
39 | Optionally, cross-jumping can be done. Currently it is done | |
40 | only the last time (when after reload and before final). | |
41 | In fact, the code for cross-jumping now assumes that register | |
42 | allocation has been done, since it uses `rtx_renumbered_equal_p'. | |
43 | ||
44 | Jump optimization is done after cse when cse's constant-propagation | |
45 | causes jumps to become unconditional or to be deleted. | |
46 | ||
47 | Unreachable loops are not detected here, because the labels | |
48 | have references and the insns appear reachable from the labels. | |
49 | find_basic_blocks in flow.c finds and deletes such loops. | |
50 | ||
51 | The subroutines delete_insn, redirect_jump, and invert_jump are used | |
52 | from other passes as well. */ | |
53 | ||
54 | #include "config.h" | |
e9a25f70 | 55 | #include <stdio.h> |
15a63be1 RK |
56 | #include "rtl.h" |
57 | #include "flags.h" | |
58 | #include "hard-reg-set.h" | |
59 | #include "regs.h" | |
15a63be1 RK |
60 | #include "insn-config.h" |
61 | #include "insn-flags.h" | |
e9a25f70 | 62 | #include "recog.h" |
3c86a619 | 63 | #include "expr.h" |
15a63be1 | 64 | #include "real.h" |
6adb4e3a | 65 | #include "except.h" |
15a63be1 RK |
66 | |
67 | /* ??? Eventually must record somehow the labels used by jumps | |
68 | from nested functions. */ | |
69 | /* Pre-record the next or previous real insn for each label? | |
70 | No, this pass is very fast anyway. */ | |
71 | /* Condense consecutive labels? | |
72 | This would make life analysis faster, maybe. */ | |
73 | /* Optimize jump y; x: ... y: jumpif... x? | |
74 | Don't know if it is worth bothering with. */ | |
75 | /* Optimize two cases of conditional jump to conditional jump? | |
76 | This can never delete any instruction or make anything dead, | |
77 | or even change what is live at any point. | |
78 | So perhaps let combiner do it. */ | |
79 | ||
80 | /* Vector indexed by uid. | |
81 | For each CODE_LABEL, index by its uid to get first unconditional jump | |
82 | that jumps to the label. | |
83 | For each JUMP_INSN, index by its uid to get the next unconditional jump | |
84 | that jumps to the same label. | |
85 | Element 0 is the start of a chain of all return insns. | |
86 | (It is safe to use element 0 because insn uid 0 is not used. */ | |
87 | ||
88 | static rtx *jump_chain; | |
89 | ||
90 | /* List of labels referred to from initializers. | |
91 | These can never be deleted. */ | |
92 | rtx forced_labels; | |
93 | ||
94 | /* Maximum index in jump_chain. */ | |
95 | ||
96 | static int max_jump_chain; | |
97 | ||
98 | /* Set nonzero by jump_optimize if control can fall through | |
99 | to the end of the function. */ | |
100 | int can_reach_end; | |
101 | ||
102 | /* Indicates whether death notes are significant in cross jump analysis. | |
103 | Normally they are not significant, because of A and B jump to C, | |
104 | and R dies in A, it must die in B. But this might not be true after | |
105 | stack register conversion, and we must compare death notes in that | |
0f41302f | 106 | case. */ |
15a63be1 RK |
107 | |
108 | static int cross_jump_death_matters = 0; | |
109 | ||
8cd2aff2 RK |
110 | static int duplicate_loop_exit_test PROTO((rtx)); |
111 | static void find_cross_jump PROTO((rtx, rtx, int, rtx *, rtx *)); | |
112 | static void do_cross_jump PROTO((rtx, rtx, rtx)); | |
113 | static int jump_back_p PROTO((rtx, rtx)); | |
114 | static int tension_vector_labels PROTO((rtx, int)); | |
115 | static void mark_jump_label PROTO((rtx, rtx, int)); | |
116 | static void delete_computation PROTO((rtx)); | |
117 | static void delete_from_jump_chain PROTO((rtx)); | |
118 | static int delete_labelref_insn PROTO((rtx, rtx, int)); | |
119 | static void redirect_tablejump PROTO((rtx, rtx)); | |
956d6950 | 120 | static rtx find_insert_position PROTO((rtx, rtx)); |
15a63be1 RK |
121 | \f |
122 | /* Delete no-op jumps and optimize jumps to jumps | |
123 | and jumps around jumps. | |
124 | Delete unused labels and unreachable code. | |
125 | ||
126 | If CROSS_JUMP is 1, detect matching code | |
127 | before a jump and its destination and unify them. | |
128 | If CROSS_JUMP is 2, do cross-jumping, but pay attention to death notes. | |
129 | ||
130 | If NOOP_MOVES is nonzero, delete no-op move insns. | |
131 | ||
132 | If AFTER_REGSCAN is nonzero, then this jump pass is being run immediately | |
133 | after regscan, and it is safe to use regno_first_uid and regno_last_uid. | |
134 | ||
135 | If `optimize' is zero, don't change any code, | |
136 | just determine whether control drops off the end of the function. | |
137 | This case occurs when we have -W and not -O. | |
138 | It works because `delete_insn' checks the value of `optimize' | |
139 | and refrains from actually deleting when that is 0. */ | |
140 | ||
141 | void | |
142 | jump_optimize (f, cross_jump, noop_moves, after_regscan) | |
143 | rtx f; | |
144 | int cross_jump; | |
145 | int noop_moves; | |
146 | int after_regscan; | |
147 | { | |
484c3924 | 148 | register rtx insn, next, note; |
15a63be1 RK |
149 | int changed; |
150 | int first = 1; | |
151 | int max_uid = 0; | |
152 | rtx last_insn; | |
153 | ||
154 | cross_jump_death_matters = (cross_jump == 2); | |
155 | ||
484c3924 RK |
156 | /* Initialize LABEL_NUSES and JUMP_LABEL fields. Delete any REG_LABEL |
157 | notes whose labels don't occur in the insn any more. */ | |
15a63be1 RK |
158 | |
159 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
160 | { | |
161 | if (GET_CODE (insn) == CODE_LABEL) | |
162 | LABEL_NUSES (insn) = (LABEL_PRESERVE_P (insn) != 0); | |
163 | else if (GET_CODE (insn) == JUMP_INSN) | |
164 | JUMP_LABEL (insn) = 0; | |
484c3924 RK |
165 | else if (GET_CODE (insn) == INSN || GET_CODE (insn) == CALL_INSN) |
166 | for (note = REG_NOTES (insn); note; note = next) | |
167 | { | |
168 | next = XEXP (note, 1); | |
169 | if (REG_NOTE_KIND (note) == REG_LABEL | |
170 | && ! reg_mentioned_p (XEXP (note, 0), PATTERN (insn))) | |
171 | remove_note (insn, note); | |
172 | } | |
173 | ||
15a63be1 RK |
174 | if (INSN_UID (insn) > max_uid) |
175 | max_uid = INSN_UID (insn); | |
176 | } | |
177 | ||
178 | max_uid++; | |
179 | ||
180 | /* Delete insns following barriers, up to next label. */ | |
181 | ||
182 | for (insn = f; insn;) | |
183 | { | |
184 | if (GET_CODE (insn) == BARRIER) | |
185 | { | |
186 | insn = NEXT_INSN (insn); | |
187 | while (insn != 0 && GET_CODE (insn) != CODE_LABEL) | |
188 | { | |
189 | if (GET_CODE (insn) == NOTE | |
190 | && NOTE_LINE_NUMBER (insn) != NOTE_INSN_FUNCTION_END) | |
191 | insn = NEXT_INSN (insn); | |
192 | else | |
193 | insn = delete_insn (insn); | |
194 | } | |
195 | /* INSN is now the code_label. */ | |
196 | } | |
197 | else | |
198 | insn = NEXT_INSN (insn); | |
199 | } | |
200 | ||
201 | /* Leave some extra room for labels and duplicate exit test insns | |
202 | we make. */ | |
203 | max_jump_chain = max_uid * 14 / 10; | |
204 | jump_chain = (rtx *) alloca (max_jump_chain * sizeof (rtx)); | |
4c9a05bc | 205 | bzero ((char *) jump_chain, max_jump_chain * sizeof (rtx)); |
15a63be1 RK |
206 | |
207 | /* Mark the label each jump jumps to. | |
208 | Combine consecutive labels, and count uses of labels. | |
209 | ||
210 | For each label, make a chain (using `jump_chain') | |
211 | of all the *unconditional* jumps that jump to it; | |
212 | also make a chain of all returns. */ | |
213 | ||
214 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
8cd2aff2 | 215 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' |
15a63be1 RK |
216 | && ! INSN_DELETED_P (insn)) |
217 | { | |
218 | mark_jump_label (PATTERN (insn), insn, cross_jump); | |
219 | if (GET_CODE (insn) == JUMP_INSN) | |
220 | { | |
221 | if (JUMP_LABEL (insn) != 0 && simplejump_p (insn)) | |
222 | { | |
223 | jump_chain[INSN_UID (insn)] | |
224 | = jump_chain[INSN_UID (JUMP_LABEL (insn))]; | |
225 | jump_chain[INSN_UID (JUMP_LABEL (insn))] = insn; | |
226 | } | |
227 | if (GET_CODE (PATTERN (insn)) == RETURN) | |
228 | { | |
229 | jump_chain[INSN_UID (insn)] = jump_chain[0]; | |
230 | jump_chain[0] = insn; | |
231 | } | |
232 | } | |
233 | } | |
234 | ||
235 | /* Keep track of labels used from static data; | |
236 | they cannot ever be deleted. */ | |
237 | ||
238 | for (insn = forced_labels; insn; insn = XEXP (insn, 1)) | |
239 | LABEL_NUSES (XEXP (insn, 0))++; | |
240 | ||
6adb4e3a MS |
241 | check_exception_handler_labels (); |
242 | ||
243 | /* Keep track of labels used for marking handlers for exception | |
244 | regions; they cannot usually be deleted. */ | |
245 | ||
246 | for (insn = exception_handler_labels; insn; insn = XEXP (insn, 1)) | |
247 | LABEL_NUSES (XEXP (insn, 0))++; | |
248 | ||
249 | exception_optimize (); | |
250 | ||
15a63be1 RK |
251 | /* Delete all labels already not referenced. |
252 | Also find the last insn. */ | |
253 | ||
254 | last_insn = 0; | |
255 | for (insn = f; insn; ) | |
256 | { | |
257 | if (GET_CODE (insn) == CODE_LABEL && LABEL_NUSES (insn) == 0) | |
258 | insn = delete_insn (insn); | |
259 | else | |
260 | { | |
261 | last_insn = insn; | |
262 | insn = NEXT_INSN (insn); | |
263 | } | |
264 | } | |
265 | ||
266 | if (!optimize) | |
267 | { | |
268 | /* See if there is still a NOTE_INSN_FUNCTION_END in this function. | |
269 | If so record that this function can drop off the end. */ | |
270 | ||
271 | insn = last_insn; | |
272 | { | |
273 | int n_labels = 1; | |
274 | while (insn | |
275 | /* One label can follow the end-note: the return label. */ | |
276 | && ((GET_CODE (insn) == CODE_LABEL && n_labels-- > 0) | |
277 | /* Ordinary insns can follow it if returning a structure. */ | |
278 | || GET_CODE (insn) == INSN | |
279 | /* If machine uses explicit RETURN insns, no epilogue, | |
280 | then one of them follows the note. */ | |
281 | || (GET_CODE (insn) == JUMP_INSN | |
282 | && GET_CODE (PATTERN (insn)) == RETURN) | |
60374599 DE |
283 | /* A barrier can follow the return insn. */ |
284 | || GET_CODE (insn) == BARRIER | |
15a63be1 RK |
285 | /* Other kinds of notes can follow also. */ |
286 | || (GET_CODE (insn) == NOTE | |
287 | && NOTE_LINE_NUMBER (insn) != NOTE_INSN_FUNCTION_END))) | |
288 | insn = PREV_INSN (insn); | |
289 | } | |
290 | ||
291 | /* Report if control can fall through at the end of the function. */ | |
292 | if (insn && GET_CODE (insn) == NOTE | |
293 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_END | |
294 | && ! INSN_DELETED_P (insn)) | |
295 | can_reach_end = 1; | |
296 | ||
297 | /* Zero the "deleted" flag of all the "deleted" insns. */ | |
298 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
299 | INSN_DELETED_P (insn) = 0; | |
300 | return; | |
301 | } | |
302 | ||
303 | #ifdef HAVE_return | |
304 | if (HAVE_return) | |
305 | { | |
306 | /* If we fall through to the epilogue, see if we can insert a RETURN insn | |
307 | in front of it. If the machine allows it at this point (we might be | |
308 | after reload for a leaf routine), it will improve optimization for it | |
309 | to be there. */ | |
310 | insn = get_last_insn (); | |
311 | while (insn && GET_CODE (insn) == NOTE) | |
312 | insn = PREV_INSN (insn); | |
313 | ||
314 | if (insn && GET_CODE (insn) != BARRIER) | |
315 | { | |
316 | emit_jump_insn (gen_return ()); | |
317 | emit_barrier (); | |
318 | } | |
319 | } | |
320 | #endif | |
321 | ||
322 | if (noop_moves) | |
323 | for (insn = f; insn; ) | |
324 | { | |
2156dfe3 | 325 | next = NEXT_INSN (insn); |
15a63be1 RK |
326 | |
327 | if (GET_CODE (insn) == INSN) | |
328 | { | |
329 | register rtx body = PATTERN (insn); | |
330 | ||
331 | /* Combine stack_adjusts with following push_insns. */ | |
332 | #ifdef PUSH_ROUNDING | |
333 | if (GET_CODE (body) == SET | |
334 | && SET_DEST (body) == stack_pointer_rtx | |
335 | && GET_CODE (SET_SRC (body)) == PLUS | |
336 | && XEXP (SET_SRC (body), 0) == stack_pointer_rtx | |
337 | && GET_CODE (XEXP (SET_SRC (body), 1)) == CONST_INT | |
338 | && INTVAL (XEXP (SET_SRC (body), 1)) > 0) | |
339 | { | |
340 | rtx p; | |
341 | rtx stack_adjust_insn = insn; | |
342 | int stack_adjust_amount = INTVAL (XEXP (SET_SRC (body), 1)); | |
343 | int total_pushed = 0; | |
344 | int pushes = 0; | |
345 | ||
346 | /* Find all successive push insns. */ | |
347 | p = insn; | |
348 | /* Don't convert more than three pushes; | |
349 | that starts adding too many displaced addresses | |
350 | and the whole thing starts becoming a losing | |
351 | proposition. */ | |
352 | while (pushes < 3) | |
353 | { | |
354 | rtx pbody, dest; | |
355 | p = next_nonnote_insn (p); | |
356 | if (p == 0 || GET_CODE (p) != INSN) | |
357 | break; | |
358 | pbody = PATTERN (p); | |
359 | if (GET_CODE (pbody) != SET) | |
360 | break; | |
361 | dest = SET_DEST (pbody); | |
362 | /* Allow a no-op move between the adjust and the push. */ | |
363 | if (GET_CODE (dest) == REG | |
364 | && GET_CODE (SET_SRC (pbody)) == REG | |
365 | && REGNO (dest) == REGNO (SET_SRC (pbody))) | |
366 | continue; | |
367 | if (! (GET_CODE (dest) == MEM | |
368 | && GET_CODE (XEXP (dest, 0)) == POST_INC | |
369 | && XEXP (XEXP (dest, 0), 0) == stack_pointer_rtx)) | |
370 | break; | |
371 | pushes++; | |
1ad4c71a | 372 | if (total_pushed + GET_MODE_SIZE (GET_MODE (SET_DEST (pbody))) |
15a63be1 RK |
373 | > stack_adjust_amount) |
374 | break; | |
1ad4c71a | 375 | total_pushed += GET_MODE_SIZE (GET_MODE (SET_DEST (pbody))); |
15a63be1 RK |
376 | } |
377 | ||
378 | /* Discard the amount pushed from the stack adjust; | |
379 | maybe eliminate it entirely. */ | |
380 | if (total_pushed >= stack_adjust_amount) | |
381 | { | |
344a8220 | 382 | delete_computation (stack_adjust_insn); |
15a63be1 RK |
383 | total_pushed = stack_adjust_amount; |
384 | } | |
385 | else | |
386 | XEXP (SET_SRC (PATTERN (stack_adjust_insn)), 1) | |
5f4f0e22 | 387 | = GEN_INT (stack_adjust_amount - total_pushed); |
15a63be1 RK |
388 | |
389 | /* Change the appropriate push insns to ordinary stores. */ | |
390 | p = insn; | |
391 | while (total_pushed > 0) | |
392 | { | |
393 | rtx pbody, dest; | |
394 | p = next_nonnote_insn (p); | |
395 | if (GET_CODE (p) != INSN) | |
396 | break; | |
397 | pbody = PATTERN (p); | |
398 | if (GET_CODE (pbody) == SET) | |
399 | break; | |
400 | dest = SET_DEST (pbody); | |
401 | if (! (GET_CODE (dest) == MEM | |
402 | && GET_CODE (XEXP (dest, 0)) == POST_INC | |
403 | && XEXP (XEXP (dest, 0), 0) == stack_pointer_rtx)) | |
404 | break; | |
1ad4c71a | 405 | total_pushed -= GET_MODE_SIZE (GET_MODE (SET_DEST (pbody))); |
15a63be1 RK |
406 | /* If this push doesn't fully fit in the space |
407 | of the stack adjust that we deleted, | |
408 | make another stack adjust here for what we | |
409 | didn't use up. There should be peepholes | |
410 | to recognize the resulting sequence of insns. */ | |
411 | if (total_pushed < 0) | |
412 | { | |
413 | emit_insn_before (gen_add2_insn (stack_pointer_rtx, | |
5f4f0e22 | 414 | GEN_INT (- total_pushed)), |
15a63be1 RK |
415 | p); |
416 | break; | |
417 | } | |
418 | XEXP (dest, 0) | |
419 | = plus_constant (stack_pointer_rtx, total_pushed); | |
420 | } | |
421 | } | |
422 | #endif | |
423 | ||
424 | /* Detect and delete no-op move instructions | |
425 | resulting from not allocating a parameter in a register. */ | |
426 | ||
427 | if (GET_CODE (body) == SET | |
428 | && (SET_DEST (body) == SET_SRC (body) | |
429 | || (GET_CODE (SET_DEST (body)) == MEM | |
430 | && GET_CODE (SET_SRC (body)) == MEM | |
431 | && rtx_equal_p (SET_SRC (body), SET_DEST (body)))) | |
432 | && ! (GET_CODE (SET_DEST (body)) == MEM | |
433 | && MEM_VOLATILE_P (SET_DEST (body))) | |
434 | && ! (GET_CODE (SET_SRC (body)) == MEM | |
435 | && MEM_VOLATILE_P (SET_SRC (body)))) | |
344a8220 | 436 | delete_computation (insn); |
15a63be1 RK |
437 | |
438 | /* Detect and ignore no-op move instructions | |
439 | resulting from smart or fortuitous register allocation. */ | |
440 | ||
441 | else if (GET_CODE (body) == SET) | |
442 | { | |
443 | int sreg = true_regnum (SET_SRC (body)); | |
444 | int dreg = true_regnum (SET_DEST (body)); | |
445 | ||
446 | if (sreg == dreg && sreg >= 0) | |
447 | delete_insn (insn); | |
448 | else if (sreg >= 0 && dreg >= 0) | |
449 | { | |
450 | rtx trial; | |
5f4f0e22 CH |
451 | rtx tem = find_equiv_reg (NULL_RTX, insn, 0, |
452 | sreg, NULL_PTR, dreg, | |
15a63be1 RK |
453 | GET_MODE (SET_SRC (body))); |
454 | ||
db3cf6fb MS |
455 | if (tem != 0 |
456 | && GET_MODE (tem) == GET_MODE (SET_DEST (body))) | |
15a63be1 RK |
457 | { |
458 | /* DREG may have been the target of a REG_DEAD note in | |
459 | the insn which makes INSN redundant. If so, reorg | |
460 | would still think it is dead. So search for such a | |
461 | note and delete it if we find it. */ | |
59df2b2b RK |
462 | if (! find_regno_note (insn, REG_UNUSED, dreg)) |
463 | for (trial = prev_nonnote_insn (insn); | |
464 | trial && GET_CODE (trial) != CODE_LABEL; | |
465 | trial = prev_nonnote_insn (trial)) | |
466 | if (find_regno_note (trial, REG_DEAD, dreg)) | |
467 | { | |
468 | remove_death (dreg, trial); | |
469 | break; | |
470 | } | |
471 | #ifdef PRESERVE_DEATH_INFO_REGNO_P | |
472 | /* Deleting insn could lose a death-note for SREG | |
473 | so don't do it if final needs accurate | |
474 | death-notes. */ | |
475 | if (PRESERVE_DEATH_INFO_REGNO_P (sreg) | |
476 | && (trial = find_regno_note (insn, REG_DEAD, sreg))) | |
477 | { | |
478 | /* Change this into a USE so that we won't emit | |
479 | code for it, but still can keep the note. */ | |
480 | PATTERN (insn) | |
481 | = gen_rtx (USE, VOIDmode, XEXP (trial, 0)); | |
d8db8192 | 482 | INSN_CODE (insn) = -1; |
59df2b2b RK |
483 | /* Remove all reg notes but the REG_DEAD one. */ |
484 | REG_NOTES (insn) = trial; | |
485 | XEXP (trial, 1) = NULL_RTX; | |
486 | } | |
487 | else | |
488 | #endif | |
15a63be1 RK |
489 | delete_insn (insn); |
490 | } | |
491 | } | |
492 | else if (dreg >= 0 && CONSTANT_P (SET_SRC (body)) | |
5f4f0e22 CH |
493 | && find_equiv_reg (SET_SRC (body), insn, 0, dreg, |
494 | NULL_PTR, 0, | |
495 | GET_MODE (SET_DEST (body)))) | |
15a63be1 RK |
496 | { |
497 | /* This handles the case where we have two consecutive | |
498 | assignments of the same constant to pseudos that didn't | |
499 | get a hard reg. Each SET from the constant will be | |
500 | converted into a SET of the spill register and an | |
501 | output reload will be made following it. This produces | |
502 | two loads of the same constant into the same spill | |
503 | register. */ | |
504 | ||
505 | rtx in_insn = insn; | |
506 | ||
507 | /* Look back for a death note for the first reg. | |
508 | If there is one, it is no longer accurate. */ | |
509 | while (in_insn && GET_CODE (in_insn) != CODE_LABEL) | |
510 | { | |
511 | if ((GET_CODE (in_insn) == INSN | |
512 | || GET_CODE (in_insn) == JUMP_INSN) | |
513 | && find_regno_note (in_insn, REG_DEAD, dreg)) | |
514 | { | |
515 | remove_death (dreg, in_insn); | |
516 | break; | |
517 | } | |
518 | in_insn = PREV_INSN (in_insn); | |
519 | } | |
520 | ||
521 | /* Delete the second load of the value. */ | |
522 | delete_insn (insn); | |
523 | } | |
524 | } | |
525 | else if (GET_CODE (body) == PARALLEL) | |
526 | { | |
527 | /* If each part is a set between two identical registers or | |
0f41302f | 528 | a USE or CLOBBER, delete the insn. */ |
15a63be1 RK |
529 | int i, sreg, dreg; |
530 | rtx tem; | |
531 | ||
532 | for (i = XVECLEN (body, 0) - 1; i >= 0; i--) | |
533 | { | |
534 | tem = XVECEXP (body, 0, i); | |
535 | if (GET_CODE (tem) == USE || GET_CODE (tem) == CLOBBER) | |
536 | continue; | |
537 | ||
538 | if (GET_CODE (tem) != SET | |
539 | || (sreg = true_regnum (SET_SRC (tem))) < 0 | |
540 | || (dreg = true_regnum (SET_DEST (tem))) < 0 | |
541 | || dreg != sreg) | |
542 | break; | |
543 | } | |
544 | ||
545 | if (i < 0) | |
546 | delete_insn (insn); | |
547 | } | |
15a63be1 | 548 | /* Also delete insns to store bit fields if they are no-ops. */ |
f76b9db2 ILT |
549 | /* Not worth the hair to detect this in the big-endian case. */ |
550 | else if (! BYTES_BIG_ENDIAN | |
551 | && GET_CODE (body) == SET | |
15a63be1 RK |
552 | && GET_CODE (SET_DEST (body)) == ZERO_EXTRACT |
553 | && XEXP (SET_DEST (body), 2) == const0_rtx | |
554 | && XEXP (SET_DEST (body), 0) == SET_SRC (body) | |
555 | && ! (GET_CODE (SET_SRC (body)) == MEM | |
556 | && MEM_VOLATILE_P (SET_SRC (body)))) | |
557 | delete_insn (insn); | |
15a63be1 RK |
558 | } |
559 | insn = next; | |
560 | } | |
561 | ||
2156dfe3 RK |
562 | /* If we haven't yet gotten to reload and we have just run regscan, |
563 | delete any insn that sets a register that isn't used elsewhere. | |
564 | This helps some of the optimizations below by having less insns | |
565 | being jumped around. */ | |
566 | ||
567 | if (! reload_completed && after_regscan) | |
568 | for (insn = f; insn; insn = next) | |
569 | { | |
570 | rtx set = single_set (insn); | |
571 | ||
572 | next = NEXT_INSN (insn); | |
573 | ||
574 | if (set && GET_CODE (SET_DEST (set)) == REG | |
575 | && REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER | |
b1f21e0a | 576 | && REGNO_FIRST_UID (REGNO (SET_DEST (set))) == INSN_UID (insn) |
b803fb99 RS |
577 | /* We use regno_last_note_uid so as not to delete the setting |
578 | of a reg that's used in notes. A subsequent optimization | |
579 | might arrange to use that reg for real. */ | |
b1f21e0a | 580 | && REGNO_LAST_NOTE_UID (REGNO (SET_DEST (set))) == INSN_UID (insn) |
d008e26c RK |
581 | && ! side_effects_p (SET_SRC (set)) |
582 | && ! find_reg_note (insn, REG_RETVAL, 0)) | |
2156dfe3 RK |
583 | delete_insn (insn); |
584 | } | |
585 | ||
15a63be1 RK |
586 | /* Now iterate optimizing jumps until nothing changes over one pass. */ |
587 | changed = 1; | |
588 | while (changed) | |
589 | { | |
15a63be1 RK |
590 | changed = 0; |
591 | ||
592 | for (insn = f; insn; insn = next) | |
593 | { | |
594 | rtx reallabelprev; | |
2156dfe3 | 595 | rtx temp, temp1, temp2, temp3, temp4, temp5, temp6; |
15a63be1 | 596 | rtx nlabel; |
3915de94 | 597 | int this_is_simplejump, this_is_condjump, reversep; |
3480bb98 | 598 | int this_is_condjump_in_parallel; |
15a63be1 RK |
599 | #if 0 |
600 | /* If NOT the first iteration, if this is the last jump pass | |
601 | (just before final), do the special peephole optimizations. | |
602 | Avoiding the first iteration gives ordinary jump opts | |
603 | a chance to work before peephole opts. */ | |
604 | ||
605 | if (reload_completed && !first && !flag_no_peephole) | |
606 | if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN) | |
607 | peephole (insn); | |
608 | #endif | |
609 | ||
610 | /* That could have deleted some insns after INSN, so check now | |
611 | what the following insn is. */ | |
612 | ||
613 | next = NEXT_INSN (insn); | |
614 | ||
615 | /* See if this is a NOTE_INSN_LOOP_BEG followed by an unconditional | |
616 | jump. Try to optimize by duplicating the loop exit test if so. | |
617 | This is only safe immediately after regscan, because it uses | |
618 | the values of regno_first_uid and regno_last_uid. */ | |
619 | if (after_regscan && GET_CODE (insn) == NOTE | |
620 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG | |
621 | && (temp1 = next_nonnote_insn (insn)) != 0 | |
622 | && simplejump_p (temp1)) | |
623 | { | |
624 | temp = PREV_INSN (insn); | |
625 | if (duplicate_loop_exit_test (insn)) | |
626 | { | |
627 | changed = 1; | |
628 | next = NEXT_INSN (temp); | |
629 | continue; | |
630 | } | |
631 | } | |
632 | ||
633 | if (GET_CODE (insn) != JUMP_INSN) | |
634 | continue; | |
635 | ||
636 | this_is_simplejump = simplejump_p (insn); | |
637 | this_is_condjump = condjump_p (insn); | |
3480bb98 | 638 | this_is_condjump_in_parallel = condjump_in_parallel_p (insn); |
15a63be1 RK |
639 | |
640 | /* Tension the labels in dispatch tables. */ | |
641 | ||
642 | if (GET_CODE (PATTERN (insn)) == ADDR_VEC) | |
643 | changed |= tension_vector_labels (PATTERN (insn), 0); | |
644 | if (GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC) | |
645 | changed |= tension_vector_labels (PATTERN (insn), 1); | |
646 | ||
647 | /* If a dispatch table always goes to the same place, | |
648 | get rid of it and replace the insn that uses it. */ | |
649 | ||
650 | if (GET_CODE (PATTERN (insn)) == ADDR_VEC | |
651 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC) | |
652 | { | |
653 | int i; | |
654 | rtx pat = PATTERN (insn); | |
655 | int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC; | |
656 | int len = XVECLEN (pat, diff_vec_p); | |
657 | rtx dispatch = prev_real_insn (insn); | |
658 | ||
659 | for (i = 0; i < len; i++) | |
660 | if (XEXP (XVECEXP (pat, diff_vec_p, i), 0) | |
661 | != XEXP (XVECEXP (pat, diff_vec_p, 0), 0)) | |
662 | break; | |
663 | if (i == len | |
0546e268 | 664 | && dispatch != 0 |
15a63be1 RK |
665 | && GET_CODE (dispatch) == JUMP_INSN |
666 | && JUMP_LABEL (dispatch) != 0 | |
667 | /* Don't mess with a casesi insn. */ | |
668 | && !(GET_CODE (PATTERN (dispatch)) == SET | |
669 | && (GET_CODE (SET_SRC (PATTERN (dispatch))) | |
670 | == IF_THEN_ELSE)) | |
671 | && next_real_insn (JUMP_LABEL (dispatch)) == insn) | |
672 | { | |
673 | redirect_tablejump (dispatch, | |
674 | XEXP (XVECEXP (pat, diff_vec_p, 0), 0)); | |
675 | changed = 1; | |
676 | } | |
677 | } | |
678 | ||
679 | reallabelprev = prev_active_insn (JUMP_LABEL (insn)); | |
680 | ||
681 | /* If a jump references the end of the function, try to turn | |
682 | it into a RETURN insn, possibly a conditional one. */ | |
683 | if (JUMP_LABEL (insn) | |
8e318904 JL |
684 | && (next_active_insn (JUMP_LABEL (insn)) == 0 |
685 | || GET_CODE (PATTERN (next_active_insn (JUMP_LABEL (insn)))) | |
686 | == RETURN)) | |
5f4f0e22 | 687 | changed |= redirect_jump (insn, NULL_RTX); |
15a63be1 RK |
688 | |
689 | /* Detect jump to following insn. */ | |
690 | if (reallabelprev == insn && condjump_p (insn)) | |
691 | { | |
cd423ead | 692 | next = next_real_insn (JUMP_LABEL (insn)); |
15a63be1 RK |
693 | delete_jump (insn); |
694 | changed = 1; | |
695 | continue; | |
696 | } | |
697 | ||
d45cf215 | 698 | /* If we have an unconditional jump preceded by a USE, try to put |
15a63be1 RK |
699 | the USE before the target and jump there. This simplifies many |
700 | of the optimizations below since we don't have to worry about | |
701 | dealing with these USE insns. We only do this if the label | |
702 | being branch to already has the identical USE or if code | |
703 | never falls through to that label. */ | |
704 | ||
705 | if (this_is_simplejump | |
706 | && (temp = prev_nonnote_insn (insn)) != 0 | |
707 | && GET_CODE (temp) == INSN && GET_CODE (PATTERN (temp)) == USE | |
708 | && (temp1 = prev_nonnote_insn (JUMP_LABEL (insn))) != 0 | |
709 | && (GET_CODE (temp1) == BARRIER | |
710 | || (GET_CODE (temp1) == INSN | |
9740123d JW |
711 | && rtx_equal_p (PATTERN (temp), PATTERN (temp1)))) |
712 | /* Don't do this optimization if we have a loop containing only | |
713 | the USE instruction, and the loop start label has a usage | |
714 | count of 1. This is because we will redo this optimization | |
715 | everytime through the outer loop, and jump opt will never | |
716 | exit. */ | |
717 | && ! ((temp2 = prev_nonnote_insn (temp)) != 0 | |
718 | && temp2 == JUMP_LABEL (insn) | |
719 | && LABEL_NUSES (temp2) == 1)) | |
15a63be1 RK |
720 | { |
721 | if (GET_CODE (temp1) == BARRIER) | |
722 | { | |
2156dfe3 | 723 | emit_insn_after (PATTERN (temp), temp1); |
15a63be1 RK |
724 | temp1 = NEXT_INSN (temp1); |
725 | } | |
15a63be1 | 726 | |
2156dfe3 | 727 | delete_insn (temp); |
15a63be1 RK |
728 | redirect_jump (insn, get_label_before (temp1)); |
729 | reallabelprev = prev_real_insn (temp1); | |
730 | changed = 1; | |
731 | } | |
732 | ||
733 | /* Simplify if (...) x = a; else x = b; by converting it | |
734 | to x = b; if (...) x = a; | |
735 | if B is sufficiently simple, the test doesn't involve X, | |
736 | and nothing in the test modifies B or X. | |
737 | ||
738 | If we have small register classes, we also can't do this if X | |
739 | is a hard register. | |
740 | ||
741 | If the "x = b;" insn has any REG_NOTES, we don't do this because | |
742 | of the possibility that we are running after CSE and there is a | |
743 | REG_EQUAL note that is only valid if the branch has already been | |
744 | taken. If we move the insn with the REG_EQUAL note, we may | |
745 | fold the comparison to always be false in a later CSE pass. | |
746 | (We could also delete the REG_NOTES when moving the insn, but it | |
747 | seems simpler to not move it.) An exception is that we can move | |
748 | the insn if the only note is a REG_EQUAL or REG_EQUIV whose | |
749 | value is the same as "b". | |
750 | ||
751 | INSN is the branch over the `else' part. | |
752 | ||
753 | We set: | |
754 | ||
d45cf215 | 755 | TEMP to the jump insn preceding "x = a;" |
15a63be1 RK |
756 | TEMP1 to X |
757 | TEMP2 to the insn that sets "x = b;" | |
2156dfe3 RK |
758 | TEMP3 to the insn that sets "x = a;" |
759 | TEMP4 to the set of "x = b"; */ | |
15a63be1 RK |
760 | |
761 | if (this_is_simplejump | |
762 | && (temp3 = prev_active_insn (insn)) != 0 | |
763 | && GET_CODE (temp3) == INSN | |
2156dfe3 RK |
764 | && (temp4 = single_set (temp3)) != 0 |
765 | && GET_CODE (temp1 = SET_DEST (temp4)) == REG | |
f95182a4 ILT |
766 | && (! SMALL_REGISTER_CLASSES |
767 | || REGNO (temp1) >= FIRST_PSEUDO_REGISTER) | |
15a63be1 RK |
768 | && (temp2 = next_active_insn (insn)) != 0 |
769 | && GET_CODE (temp2) == INSN | |
2156dfe3 RK |
770 | && (temp4 = single_set (temp2)) != 0 |
771 | && rtx_equal_p (SET_DEST (temp4), temp1) | |
772 | && (GET_CODE (SET_SRC (temp4)) == REG | |
773 | || GET_CODE (SET_SRC (temp4)) == SUBREG | |
774 | || CONSTANT_P (SET_SRC (temp4))) | |
15a63be1 RK |
775 | && (REG_NOTES (temp2) == 0 |
776 | || ((REG_NOTE_KIND (REG_NOTES (temp2)) == REG_EQUAL | |
777 | || REG_NOTE_KIND (REG_NOTES (temp2)) == REG_EQUIV) | |
778 | && XEXP (REG_NOTES (temp2), 1) == 0 | |
779 | && rtx_equal_p (XEXP (REG_NOTES (temp2), 0), | |
2156dfe3 | 780 | SET_SRC (temp4)))) |
15a63be1 RK |
781 | && (temp = prev_active_insn (temp3)) != 0 |
782 | && condjump_p (temp) && ! simplejump_p (temp) | |
783 | /* TEMP must skip over the "x = a;" insn */ | |
784 | && prev_real_insn (JUMP_LABEL (temp)) == insn | |
785 | && no_labels_between_p (insn, JUMP_LABEL (temp)) | |
786 | /* There must be no other entries to the "x = b;" insn. */ | |
787 | && no_labels_between_p (JUMP_LABEL (temp), temp2) | |
788 | /* INSN must either branch to the insn after TEMP2 or the insn | |
789 | after TEMP2 must branch to the same place as INSN. */ | |
790 | && (reallabelprev == temp2 | |
2156dfe3 RK |
791 | || ((temp5 = next_active_insn (temp2)) != 0 |
792 | && simplejump_p (temp5) | |
793 | && JUMP_LABEL (temp5) == JUMP_LABEL (insn)))) | |
15a63be1 RK |
794 | { |
795 | /* The test expression, X, may be a complicated test with | |
796 | multiple branches. See if we can find all the uses of | |
797 | the label that TEMP branches to without hitting a CALL_INSN | |
798 | or a jump to somewhere else. */ | |
799 | rtx target = JUMP_LABEL (temp); | |
800 | int nuses = LABEL_NUSES (target); | |
801 | rtx p, q; | |
802 | ||
803 | /* Set P to the first jump insn that goes around "x = a;". */ | |
804 | for (p = temp; nuses && p; p = prev_nonnote_insn (p)) | |
805 | { | |
806 | if (GET_CODE (p) == JUMP_INSN) | |
807 | { | |
808 | if (condjump_p (p) && ! simplejump_p (p) | |
809 | && JUMP_LABEL (p) == target) | |
810 | { | |
811 | nuses--; | |
812 | if (nuses == 0) | |
813 | break; | |
814 | } | |
815 | else | |
816 | break; | |
817 | } | |
818 | else if (GET_CODE (p) == CALL_INSN) | |
819 | break; | |
820 | } | |
821 | ||
822 | #ifdef HAVE_cc0 | |
823 | /* We cannot insert anything between a set of cc and its use | |
824 | so if P uses cc0, we must back up to the previous insn. */ | |
825 | q = prev_nonnote_insn (p); | |
826 | if (q && GET_RTX_CLASS (GET_CODE (q)) == 'i' | |
827 | && sets_cc0_p (PATTERN (q))) | |
828 | p = q; | |
829 | #endif | |
830 | ||
831 | if (p) | |
832 | p = PREV_INSN (p); | |
833 | ||
834 | /* If we found all the uses and there was no data conflict, we | |
835 | can move the assignment unless we can branch into the middle | |
836 | from somewhere. */ | |
837 | if (nuses == 0 && p | |
838 | && no_labels_between_p (p, insn) | |
839 | && ! reg_referenced_between_p (temp1, p, NEXT_INSN (temp3)) | |
840 | && ! reg_set_between_p (temp1, p, temp3) | |
2156dfe3 RK |
841 | && (GET_CODE (SET_SRC (temp4)) == CONST_INT |
842 | || ! reg_set_between_p (SET_SRC (temp4), p, temp2))) | |
15a63be1 | 843 | { |
2156dfe3 RK |
844 | emit_insn_after_with_line_notes (PATTERN (temp2), p, temp2); |
845 | delete_insn (temp2); | |
15a63be1 RK |
846 | |
847 | /* Set NEXT to an insn that we know won't go away. */ | |
848 | next = next_active_insn (insn); | |
849 | ||
850 | /* Delete the jump around the set. Note that we must do | |
851 | this before we redirect the test jumps so that it won't | |
852 | delete the code immediately following the assignment | |
853 | we moved (which might be a jump). */ | |
854 | ||
855 | delete_insn (insn); | |
856 | ||
857 | /* We either have two consecutive labels or a jump to | |
858 | a jump, so adjust all the JUMP_INSNs to branch to where | |
859 | INSN branches to. */ | |
860 | for (p = NEXT_INSN (p); p != next; p = NEXT_INSN (p)) | |
861 | if (GET_CODE (p) == JUMP_INSN) | |
862 | redirect_jump (p, target); | |
863 | ||
864 | changed = 1; | |
865 | continue; | |
866 | } | |
867 | } | |
868 | ||
66bd9361 JW |
869 | /* Simplify if (...) { x = a; goto l; } x = b; by converting it |
870 | to x = a; if (...) goto l; x = b; | |
871 | if A is sufficiently simple, the test doesn't involve X, | |
872 | and nothing in the test modifies A or X. | |
873 | ||
874 | If we have small register classes, we also can't do this if X | |
875 | is a hard register. | |
876 | ||
877 | If the "x = a;" insn has any REG_NOTES, we don't do this because | |
878 | of the possibility that we are running after CSE and there is a | |
879 | REG_EQUAL note that is only valid if the branch has already been | |
880 | taken. If we move the insn with the REG_EQUAL note, we may | |
881 | fold the comparison to always be false in a later CSE pass. | |
882 | (We could also delete the REG_NOTES when moving the insn, but it | |
883 | seems simpler to not move it.) An exception is that we can move | |
884 | the insn if the only note is a REG_EQUAL or REG_EQUIV whose | |
885 | value is the same as "a". | |
886 | ||
887 | INSN is the goto. | |
888 | ||
889 | We set: | |
890 | ||
891 | TEMP to the jump insn preceding "x = a;" | |
892 | TEMP1 to X | |
893 | TEMP2 to the insn that sets "x = b;" | |
894 | TEMP3 to the insn that sets "x = a;" | |
895 | TEMP4 to the set of "x = a"; */ | |
896 | ||
897 | if (this_is_simplejump | |
898 | && (temp2 = next_active_insn (insn)) != 0 | |
899 | && GET_CODE (temp2) == INSN | |
900 | && (temp4 = single_set (temp2)) != 0 | |
901 | && GET_CODE (temp1 = SET_DEST (temp4)) == REG | |
f95182a4 ILT |
902 | && (! SMALL_REGISTER_CLASSES |
903 | || REGNO (temp1) >= FIRST_PSEUDO_REGISTER) | |
66bd9361 JW |
904 | && (temp3 = prev_active_insn (insn)) != 0 |
905 | && GET_CODE (temp3) == INSN | |
906 | && (temp4 = single_set (temp3)) != 0 | |
907 | && rtx_equal_p (SET_DEST (temp4), temp1) | |
908 | && (GET_CODE (SET_SRC (temp4)) == REG | |
909 | || GET_CODE (SET_SRC (temp4)) == SUBREG | |
910 | || CONSTANT_P (SET_SRC (temp4))) | |
911 | && (REG_NOTES (temp3) == 0 | |
912 | || ((REG_NOTE_KIND (REG_NOTES (temp3)) == REG_EQUAL | |
913 | || REG_NOTE_KIND (REG_NOTES (temp3)) == REG_EQUIV) | |
914 | && XEXP (REG_NOTES (temp3), 1) == 0 | |
915 | && rtx_equal_p (XEXP (REG_NOTES (temp3), 0), | |
916 | SET_SRC (temp4)))) | |
917 | && (temp = prev_active_insn (temp3)) != 0 | |
918 | && condjump_p (temp) && ! simplejump_p (temp) | |
919 | /* TEMP must skip over the "x = a;" insn */ | |
920 | && prev_real_insn (JUMP_LABEL (temp)) == insn | |
921 | && no_labels_between_p (temp, insn)) | |
922 | { | |
923 | rtx prev_label = JUMP_LABEL (temp); | |
924 | rtx insert_after = prev_nonnote_insn (temp); | |
925 | ||
926 | #ifdef HAVE_cc0 | |
927 | /* We cannot insert anything between a set of cc and its use. */ | |
928 | if (insert_after && GET_RTX_CLASS (GET_CODE (insert_after)) == 'i' | |
929 | && sets_cc0_p (PATTERN (insert_after))) | |
930 | insert_after = prev_nonnote_insn (insert_after); | |
931 | #endif | |
932 | ++LABEL_NUSES (prev_label); | |
933 | ||
934 | if (insert_after | |
935 | && no_labels_between_p (insert_after, temp) | |
7a7233ff | 936 | && ! reg_referenced_between_p (temp1, insert_after, temp3) |
04bd0246 DE |
937 | && ! reg_referenced_between_p (temp1, temp3, |
938 | NEXT_INSN (temp2)) | |
66bd9361 JW |
939 | && ! reg_set_between_p (temp1, insert_after, temp) |
940 | && (GET_CODE (SET_SRC (temp4)) == CONST_INT | |
941 | || ! reg_set_between_p (SET_SRC (temp4), | |
942 | insert_after, temp)) | |
943 | && invert_jump (temp, JUMP_LABEL (insn))) | |
944 | { | |
945 | emit_insn_after_with_line_notes (PATTERN (temp3), | |
946 | insert_after, temp3); | |
947 | delete_insn (temp3); | |
948 | delete_insn (insn); | |
949 | /* Set NEXT to an insn that we know won't go away. */ | |
950 | next = temp2; | |
951 | changed = 1; | |
952 | } | |
953 | if (prev_label && --LABEL_NUSES (prev_label) == 0) | |
954 | delete_insn (prev_label); | |
955 | if (changed) | |
956 | continue; | |
957 | } | |
958 | ||
2156dfe3 RK |
959 | #ifndef HAVE_cc0 |
960 | /* If we have if (...) x = exp; and branches are expensive, | |
961 | EXP is a single insn, does not have any side effects, cannot | |
962 | trap, and is not too costly, convert this to | |
963 | t = exp; if (...) x = t; | |
964 | ||
965 | Don't do this when we have CC0 because it is unlikely to help | |
966 | and we'd need to worry about where to place the new insn and | |
967 | the potential for conflicts. We also can't do this when we have | |
968 | notes on the insn for the same reason as above. | |
969 | ||
970 | We set: | |
971 | ||
972 | TEMP to the "x = exp;" insn. | |
973 | TEMP1 to the single set in the "x = exp; insn. | |
974 | TEMP2 to "x". */ | |
975 | ||
976 | if (! reload_completed | |
977 | && this_is_condjump && ! this_is_simplejump | |
978 | && BRANCH_COST >= 3 | |
979 | && (temp = next_nonnote_insn (insn)) != 0 | |
a8fc41af | 980 | && GET_CODE (temp) == INSN |
2156dfe3 RK |
981 | && REG_NOTES (temp) == 0 |
982 | && (reallabelprev == temp | |
983 | || ((temp2 = next_active_insn (temp)) != 0 | |
984 | && simplejump_p (temp2) | |
985 | && JUMP_LABEL (temp2) == JUMP_LABEL (insn))) | |
986 | && (temp1 = single_set (temp)) != 0 | |
987 | && (temp2 = SET_DEST (temp1), GET_CODE (temp2) == REG) | |
988 | && GET_MODE_CLASS (GET_MODE (temp2)) == MODE_INT | |
f95182a4 ILT |
989 | && (! SMALL_REGISTER_CLASSES |
990 | || REGNO (temp2) >= FIRST_PSEUDO_REGISTER) | |
2156dfe3 RK |
991 | && GET_CODE (SET_SRC (temp1)) != REG |
992 | && GET_CODE (SET_SRC (temp1)) != SUBREG | |
993 | && GET_CODE (SET_SRC (temp1)) != CONST_INT | |
994 | && ! side_effects_p (SET_SRC (temp1)) | |
995 | && ! may_trap_p (SET_SRC (temp1)) | |
97fa962f | 996 | && rtx_cost (SET_SRC (temp1), SET) < 10) |
2156dfe3 RK |
997 | { |
998 | rtx new = gen_reg_rtx (GET_MODE (temp2)); | |
999 | ||
956d6950 JL |
1000 | if ((temp3 = find_insert_position (insn, temp)) |
1001 | && validate_change (temp, &SET_DEST (temp1), new, 0)) | |
2156dfe3 RK |
1002 | { |
1003 | next = emit_insn_after (gen_move_insn (temp2, new), insn); | |
1004 | emit_insn_after_with_line_notes (PATTERN (temp), | |
956d6950 | 1005 | PREV_INSN (temp3), temp); |
2156dfe3 | 1006 | delete_insn (temp); |
5954c8a8 | 1007 | reallabelprev = prev_active_insn (JUMP_LABEL (insn)); |
2156dfe3 RK |
1008 | } |
1009 | } | |
1010 | ||
1011 | /* Similarly, if it takes two insns to compute EXP but they | |
1012 | have the same destination. Here TEMP3 will be the second | |
1013 | insn and TEMP4 the SET from that insn. */ | |
1014 | ||
1015 | if (! reload_completed | |
1016 | && this_is_condjump && ! this_is_simplejump | |
1017 | && BRANCH_COST >= 4 | |
1018 | && (temp = next_nonnote_insn (insn)) != 0 | |
a8fc41af | 1019 | && GET_CODE (temp) == INSN |
2156dfe3 RK |
1020 | && REG_NOTES (temp) == 0 |
1021 | && (temp3 = next_nonnote_insn (temp)) != 0 | |
a8fc41af | 1022 | && GET_CODE (temp3) == INSN |
2156dfe3 RK |
1023 | && REG_NOTES (temp3) == 0 |
1024 | && (reallabelprev == temp3 | |
1025 | || ((temp2 = next_active_insn (temp3)) != 0 | |
1026 | && simplejump_p (temp2) | |
1027 | && JUMP_LABEL (temp2) == JUMP_LABEL (insn))) | |
1028 | && (temp1 = single_set (temp)) != 0 | |
1029 | && (temp2 = SET_DEST (temp1), GET_CODE (temp2) == REG) | |
1030 | && GET_MODE_CLASS (GET_MODE (temp2)) == MODE_INT | |
f95182a4 ILT |
1031 | && (! SMALL_REGISTER_CLASSES |
1032 | || REGNO (temp2) >= FIRST_PSEUDO_REGISTER) | |
2156dfe3 RK |
1033 | && ! side_effects_p (SET_SRC (temp1)) |
1034 | && ! may_trap_p (SET_SRC (temp1)) | |
97fa962f | 1035 | && rtx_cost (SET_SRC (temp1), SET) < 10 |
2156dfe3 RK |
1036 | && (temp4 = single_set (temp3)) != 0 |
1037 | && rtx_equal_p (SET_DEST (temp4), temp2) | |
1038 | && ! side_effects_p (SET_SRC (temp4)) | |
1039 | && ! may_trap_p (SET_SRC (temp4)) | |
97fa962f | 1040 | && rtx_cost (SET_SRC (temp4), SET) < 10) |
2156dfe3 RK |
1041 | { |
1042 | rtx new = gen_reg_rtx (GET_MODE (temp2)); | |
1043 | ||
956d6950 JL |
1044 | if ((temp5 = find_insert_position (insn, temp)) |
1045 | && (temp6 = find_insert_position (insn, temp3)) | |
1046 | && validate_change (temp, &SET_DEST (temp1), new, 0)) | |
2156dfe3 | 1047 | { |
956d6950 JL |
1048 | /* Use the earliest of temp5 and temp6. */ |
1049 | if (temp5 != insn) | |
1050 | temp6 = temp5; | |
2156dfe3 RK |
1051 | next = emit_insn_after (gen_move_insn (temp2, new), insn); |
1052 | emit_insn_after_with_line_notes (PATTERN (temp), | |
956d6950 | 1053 | PREV_INSN (temp6), temp); |
2156dfe3 RK |
1054 | emit_insn_after_with_line_notes |
1055 | (replace_rtx (PATTERN (temp3), temp2, new), | |
956d6950 | 1056 | PREV_INSN (temp6), temp3); |
2156dfe3 RK |
1057 | delete_insn (temp); |
1058 | delete_insn (temp3); | |
5954c8a8 | 1059 | reallabelprev = prev_active_insn (JUMP_LABEL (insn)); |
2156dfe3 RK |
1060 | } |
1061 | } | |
1062 | ||
1063 | /* Finally, handle the case where two insns are used to | |
1064 | compute EXP but a temporary register is used. Here we must | |
0f41302f | 1065 | ensure that the temporary register is not used anywhere else. */ |
2156dfe3 RK |
1066 | |
1067 | if (! reload_completed | |
1068 | && after_regscan | |
1069 | && this_is_condjump && ! this_is_simplejump | |
1070 | && BRANCH_COST >= 4 | |
1071 | && (temp = next_nonnote_insn (insn)) != 0 | |
a8fc41af | 1072 | && GET_CODE (temp) == INSN |
2156dfe3 RK |
1073 | && REG_NOTES (temp) == 0 |
1074 | && (temp3 = next_nonnote_insn (temp)) != 0 | |
a8fc41af | 1075 | && GET_CODE (temp3) == INSN |
2156dfe3 RK |
1076 | && REG_NOTES (temp3) == 0 |
1077 | && (reallabelprev == temp3 | |
1078 | || ((temp2 = next_active_insn (temp3)) != 0 | |
1079 | && simplejump_p (temp2) | |
1080 | && JUMP_LABEL (temp2) == JUMP_LABEL (insn))) | |
1081 | && (temp1 = single_set (temp)) != 0 | |
c03c4711 RK |
1082 | && (temp5 = SET_DEST (temp1), |
1083 | (GET_CODE (temp5) == REG | |
1084 | || (GET_CODE (temp5) == SUBREG | |
1085 | && (temp5 = SUBREG_REG (temp5), | |
1086 | GET_CODE (temp5) == REG)))) | |
2156dfe3 | 1087 | && REGNO (temp5) >= FIRST_PSEUDO_REGISTER |
b1f21e0a MM |
1088 | && REGNO_FIRST_UID (REGNO (temp5)) == INSN_UID (temp) |
1089 | && REGNO_LAST_UID (REGNO (temp5)) == INSN_UID (temp3) | |
2156dfe3 RK |
1090 | && ! side_effects_p (SET_SRC (temp1)) |
1091 | && ! may_trap_p (SET_SRC (temp1)) | |
97fa962f | 1092 | && rtx_cost (SET_SRC (temp1), SET) < 10 |
2156dfe3 RK |
1093 | && (temp4 = single_set (temp3)) != 0 |
1094 | && (temp2 = SET_DEST (temp4), GET_CODE (temp2) == REG) | |
1095 | && GET_MODE_CLASS (GET_MODE (temp2)) == MODE_INT | |
f95182a4 ILT |
1096 | && (! SMALL_REGISTER_CLASSES |
1097 | || REGNO (temp2) >= FIRST_PSEUDO_REGISTER) | |
2156dfe3 RK |
1098 | && rtx_equal_p (SET_DEST (temp4), temp2) |
1099 | && ! side_effects_p (SET_SRC (temp4)) | |
1100 | && ! may_trap_p (SET_SRC (temp4)) | |
97fa962f | 1101 | && rtx_cost (SET_SRC (temp4), SET) < 10) |
2156dfe3 RK |
1102 | { |
1103 | rtx new = gen_reg_rtx (GET_MODE (temp2)); | |
1104 | ||
956d6950 JL |
1105 | if ((temp5 = find_insert_position (insn, temp)) |
1106 | && (temp6 = find_insert_position (insn, temp3)) | |
1107 | && validate_change (temp3, &SET_DEST (temp4), new, 0)) | |
2156dfe3 | 1108 | { |
956d6950 JL |
1109 | /* Use the earliest of temp5 and temp6. */ |
1110 | if (temp5 != insn) | |
1111 | temp6 = temp5; | |
2156dfe3 RK |
1112 | next = emit_insn_after (gen_move_insn (temp2, new), insn); |
1113 | emit_insn_after_with_line_notes (PATTERN (temp), | |
956d6950 | 1114 | PREV_INSN (temp6), temp); |
2156dfe3 | 1115 | emit_insn_after_with_line_notes (PATTERN (temp3), |
956d6950 | 1116 | PREV_INSN (temp6), temp3); |
2156dfe3 RK |
1117 | delete_insn (temp); |
1118 | delete_insn (temp3); | |
5954c8a8 | 1119 | reallabelprev = prev_active_insn (JUMP_LABEL (insn)); |
2156dfe3 RK |
1120 | } |
1121 | } | |
1122 | #endif /* HAVE_cc0 */ | |
1123 | ||
7209f1f9 DE |
1124 | /* Try to use a conditional move (if the target has them), or a |
1125 | store-flag insn. The general case is: | |
1126 | ||
1127 | 1) x = a; if (...) x = b; and | |
1128 | 2) if (...) x = b; | |
1129 | ||
1130 | If the jump would be faster, the machine should not have defined | |
1131 | the movcc or scc insns!. These cases are often made by the | |
3915de94 | 1132 | previous optimization. |
15a63be1 | 1133 | |
7209f1f9 DE |
1134 | The second case is treated as x = x; if (...) x = b;. |
1135 | ||
15a63be1 RK |
1136 | INSN here is the jump around the store. We set: |
1137 | ||
1138 | TEMP to the "x = b;" insn. | |
1139 | TEMP1 to X. | |
7209f1f9 | 1140 | TEMP2 to B. |
15a63be1 RK |
1141 | TEMP3 to A (X in the second case). |
1142 | TEMP4 to the condition being tested. | |
1143 | TEMP5 to the earliest insn used to find the condition. */ | |
1144 | ||
1145 | if (/* We can't do this after reload has completed. */ | |
1146 | ! reload_completed | |
1147 | && this_is_condjump && ! this_is_simplejump | |
1148 | /* Set TEMP to the "x = b;" insn. */ | |
1149 | && (temp = next_nonnote_insn (insn)) != 0 | |
1150 | && GET_CODE (temp) == INSN | |
1151 | && GET_CODE (PATTERN (temp)) == SET | |
1152 | && GET_CODE (temp1 = SET_DEST (PATTERN (temp))) == REG | |
f95182a4 ILT |
1153 | && (! SMALL_REGISTER_CLASSES |
1154 | || REGNO (temp1) >= FIRST_PSEUDO_REGISTER) | |
15a63be1 | 1155 | && (GET_CODE (temp2 = SET_SRC (PATTERN (temp))) == REG |
a73f9fc9 | 1156 | || GET_CODE (temp2) == SUBREG |
7209f1f9 | 1157 | /* ??? How about floating point constants? */ |
15a63be1 | 1158 | || GET_CODE (temp2) == CONST_INT) |
2156dfe3 RK |
1159 | /* Allow either form, but prefer the former if both apply. |
1160 | There is no point in using the old value of TEMP1 if | |
1161 | it is a register, since cse will alias them. It can | |
1162 | lose if the old value were a hard register since CSE | |
c85f7c16 JL |
1163 | won't replace hard registers. Avoid using TEMP3 if |
1164 | small register classes and it is a hard register. */ | |
1165 | && (((temp3 = reg_set_last (temp1, insn)) != 0 | |
1166 | && ! (SMALL_REGISTER_CLASSES && GET_CODE (temp3) == REG | |
1167 | && REGNO (temp3) < FIRST_PSEUDO_REGISTER)) | |
7209f1f9 DE |
1168 | /* Make the latter case look like x = x; if (...) x = b; */ |
1169 | || (temp3 = temp1, 1)) | |
15a63be1 RK |
1170 | /* INSN must either branch to the insn after TEMP or the insn |
1171 | after TEMP must branch to the same place as INSN. */ | |
1172 | && (reallabelprev == temp | |
1173 | || ((temp4 = next_active_insn (temp)) != 0 | |
1174 | && simplejump_p (temp4) | |
1175 | && JUMP_LABEL (temp4) == JUMP_LABEL (insn))) | |
1176 | && (temp4 = get_condition (insn, &temp5)) != 0 | |
7124e1e5 RS |
1177 | /* We must be comparing objects whose modes imply the size. |
1178 | We could handle BLKmode if (1) emit_store_flag could | |
1179 | and (2) we could find the size reliably. */ | |
1180 | && GET_MODE (XEXP (temp4, 0)) != BLKmode | |
04d23d7c RK |
1181 | /* Even if branches are cheap, the store_flag optimization |
1182 | can win when the operation to be performed can be | |
1183 | expressed directly. */ | |
2156dfe3 RK |
1184 | #ifdef HAVE_cc0 |
1185 | /* If the previous insn sets CC0 and something else, we can't | |
1186 | do this since we are going to delete that insn. */ | |
1187 | ||
1188 | && ! ((temp6 = prev_nonnote_insn (insn)) != 0 | |
1189 | && GET_CODE (temp6) == INSN | |
01ca1b91 RK |
1190 | && (sets_cc0_p (PATTERN (temp6)) == -1 |
1191 | || (sets_cc0_p (PATTERN (temp6)) == 1 | |
1192 | && FIND_REG_INC_NOTE (temp6, NULL_RTX)))) | |
2156dfe3 RK |
1193 | #endif |
1194 | ) | |
15a63be1 | 1195 | { |
7209f1f9 DE |
1196 | #ifdef HAVE_conditional_move |
1197 | /* First try a conditional move. */ | |
1198 | { | |
1199 | enum rtx_code code = GET_CODE (temp4); | |
1200 | rtx var = temp1; | |
1201 | rtx cond0, cond1, aval, bval; | |
1202 | rtx target; | |
1203 | ||
a99503b1 SC |
1204 | if (SMALL_REGISTER_CLASSES |
1205 | && FUNCTION_VALUE_REGNO_P (REGNO (temp3))) | |
1206 | temp3 = temp1; | |
1207 | ||
7209f1f9 DE |
1208 | /* Copy the compared variables into cond0 and cond1, so that |
1209 | any side effects performed in or after the old comparison, | |
1210 | will not affect our compare which will come later. */ | |
1211 | /* ??? Is it possible to just use the comparison in the jump | |
1212 | insn? After all, we're going to delete it. We'd have | |
1213 | to modify emit_conditional_move to take a comparison rtx | |
1214 | instead or write a new function. */ | |
1215 | cond0 = gen_reg_rtx (GET_MODE (XEXP (temp4, 0))); | |
1216 | /* We want the target to be able to simplify comparisons with | |
1217 | zero (and maybe other constants as well), so don't create | |
1218 | pseudos for them. There's no need to either. */ | |
1219 | if (GET_CODE (XEXP (temp4, 1)) == CONST_INT | |
1220 | || GET_CODE (XEXP (temp4, 1)) == CONST_DOUBLE) | |
1221 | cond1 = XEXP (temp4, 1); | |
1222 | else | |
1223 | cond1 = gen_reg_rtx (GET_MODE (XEXP (temp4, 1))); | |
1224 | ||
1225 | aval = temp3; | |
1226 | bval = temp2; | |
1227 | ||
1228 | start_sequence (); | |
1229 | target = emit_conditional_move (var, code, | |
1230 | cond0, cond1, VOIDmode, | |
1231 | aval, bval, GET_MODE (var), | |
1232 | (code == LTU || code == GEU | |
1233 | || code == LEU || code == GTU)); | |
1234 | ||
1235 | if (target) | |
1236 | { | |
1237 | rtx seq1,seq2; | |
1238 | ||
1239 | /* Save the conditional move sequence but don't emit it | |
1240 | yet. On some machines, like the alpha, it is possible | |
1241 | that temp5 == insn, so next generate the sequence that | |
1242 | saves the compared values and then emit both | |
1243 | sequences ensuring seq1 occurs before seq2. */ | |
1244 | seq2 = get_insns (); | |
1245 | end_sequence (); | |
1246 | ||
1247 | /* Now that we can't fail, generate the copy insns that | |
1248 | preserve the compared values. */ | |
1249 | start_sequence (); | |
1250 | emit_move_insn (cond0, XEXP (temp4, 0)); | |
1251 | if (cond1 != XEXP (temp4, 1)) | |
1252 | emit_move_insn (cond1, XEXP (temp4, 1)); | |
1253 | seq1 = get_insns (); | |
1254 | end_sequence (); | |
1255 | ||
1256 | emit_insns_before (seq1, temp5); | |
777e434c RK |
1257 | /* Insert conditional move after insn, to be sure that |
1258 | the jump and a possible compare won't be separated */ | |
1259 | emit_insns_after (seq2, insn); | |
7209f1f9 DE |
1260 | |
1261 | /* ??? We can also delete the insn that sets X to A. | |
1262 | Flow will do it too though. */ | |
1263 | delete_insn (temp); | |
1264 | next = NEXT_INSN (insn); | |
1265 | delete_jump (insn); | |
1266 | changed = 1; | |
1267 | continue; | |
1268 | } | |
1269 | else | |
2156dfe3 | 1270 | end_sequence (); |
7209f1f9 DE |
1271 | } |
1272 | #endif | |
2156dfe3 | 1273 | |
7209f1f9 DE |
1274 | /* That didn't work, try a store-flag insn. |
1275 | ||
1276 | We further divide the cases into: | |
1277 | ||
1278 | 1) x = a; if (...) x = b; and either A or B is zero, | |
1279 | 2) if (...) x = 0; and jumps are expensive, | |
1280 | 3) x = a; if (...) x = b; and A and B are constants where all | |
1281 | the set bits in A are also set in B and jumps are expensive, | |
1282 | 4) x = a; if (...) x = b; and A and B non-zero, and jumps are | |
1283 | more expensive, and | |
1284 | 5) if (...) x = b; if jumps are even more expensive. */ | |
1285 | ||
1286 | if (GET_MODE_CLASS (GET_MODE (temp1)) == MODE_INT | |
1287 | && ((GET_CODE (temp3) == CONST_INT) | |
1288 | /* Make the latter case look like | |
1289 | x = x; if (...) x = 0; */ | |
1290 | || (temp3 = temp1, | |
1291 | ((BRANCH_COST >= 2 | |
1292 | && temp2 == const0_rtx) | |
1293 | || BRANCH_COST >= 3))) | |
1294 | /* If B is zero, OK; if A is zero, can only do (1) if we | |
1295 | can reverse the condition. See if (3) applies possibly | |
1296 | by reversing the condition. Prefer reversing to (4) when | |
1297 | branches are very expensive. */ | |
04d23d7c RK |
1298 | && (((BRANCH_COST >= 2 |
1299 | || STORE_FLAG_VALUE == -1 | |
1300 | || (STORE_FLAG_VALUE == 1 | |
1301 | /* Check that the mask is a power of two, | |
1302 | so that it can probably be generated | |
1303 | with a shift. */ | |
1304 | && exact_log2 (INTVAL (temp3)) >= 0)) | |
1305 | && (reversep = 0, temp2 == const0_rtx)) | |
1306 | || ((BRANCH_COST >= 2 | |
1307 | || STORE_FLAG_VALUE == -1 | |
1308 | || (STORE_FLAG_VALUE == 1 | |
1309 | && exact_log2 (INTVAL (temp2)) >= 0)) | |
1310 | && temp3 == const0_rtx | |
7209f1f9 DE |
1311 | && (reversep = can_reverse_comparison_p (temp4, insn))) |
1312 | || (BRANCH_COST >= 2 | |
1313 | && GET_CODE (temp2) == CONST_INT | |
1314 | && GET_CODE (temp3) == CONST_INT | |
1315 | && ((INTVAL (temp2) & INTVAL (temp3)) == INTVAL (temp2) | |
1316 | || ((INTVAL (temp2) & INTVAL (temp3)) == INTVAL (temp3) | |
1317 | && (reversep = can_reverse_comparison_p (temp4, | |
1318 | insn))))) | |
1319 | || BRANCH_COST >= 3) | |
1320 | ) | |
1321 | { | |
1322 | enum rtx_code code = GET_CODE (temp4); | |
1323 | rtx uval, cval, var = temp1; | |
1324 | int normalizep; | |
1325 | rtx target; | |
1326 | ||
1327 | /* If necessary, reverse the condition. */ | |
1328 | if (reversep) | |
1329 | code = reverse_condition (code), uval = temp2, cval = temp3; | |
1330 | else | |
1331 | uval = temp3, cval = temp2; | |
1332 | ||
1333 | /* If CVAL is non-zero, normalize to -1. Otherwise, if UVAL | |
1334 | is the constant 1, it is best to just compute the result | |
1335 | directly. If UVAL is constant and STORE_FLAG_VALUE | |
1336 | includes all of its bits, it is best to compute the flag | |
1337 | value unnormalized and `and' it with UVAL. Otherwise, | |
1338 | normalize to -1 and `and' with UVAL. */ | |
1339 | normalizep = (cval != const0_rtx ? -1 | |
1340 | : (uval == const1_rtx ? 1 | |
1341 | : (GET_CODE (uval) == CONST_INT | |
1342 | && (INTVAL (uval) & ~STORE_FLAG_VALUE) == 0) | |
1343 | ? 0 : -1)); | |
1344 | ||
1345 | /* We will be putting the store-flag insn immediately in | |
1346 | front of the comparison that was originally being done, | |
1347 | so we know all the variables in TEMP4 will be valid. | |
1348 | However, this might be in front of the assignment of | |
1349 | A to VAR. If it is, it would clobber the store-flag | |
1350 | we will be emitting. | |
1351 | ||
1352 | Therefore, emit into a temporary which will be copied to | |
1353 | VAR immediately after TEMP. */ | |
2156dfe3 RK |
1354 | |
1355 | start_sequence (); | |
7209f1f9 DE |
1356 | target = emit_store_flag (gen_reg_rtx (GET_MODE (var)), code, |
1357 | XEXP (temp4, 0), XEXP (temp4, 1), | |
1358 | VOIDmode, | |
1359 | (code == LTU || code == LEU | |
1360 | || code == GEU || code == GTU), | |
1361 | normalizep); | |
1362 | if (target) | |
3915de94 | 1363 | { |
7209f1f9 DE |
1364 | rtx seq; |
1365 | rtx before = insn; | |
3915de94 | 1366 | |
7209f1f9 DE |
1367 | seq = get_insns (); |
1368 | end_sequence (); | |
3915de94 | 1369 | |
7209f1f9 DE |
1370 | /* Put the store-flag insns in front of the first insn |
1371 | used to compute the condition to ensure that we | |
1372 | use the same values of them as the current | |
1373 | comparison. However, the remainder of the insns we | |
1374 | generate will be placed directly in front of the | |
1375 | jump insn, in case any of the pseudos we use | |
1376 | are modified earlier. */ | |
3915de94 | 1377 | |
7209f1f9 | 1378 | emit_insns_before (seq, temp5); |
3915de94 | 1379 | |
7209f1f9 DE |
1380 | start_sequence (); |
1381 | ||
1382 | /* Both CVAL and UVAL are non-zero. */ | |
1383 | if (cval != const0_rtx && uval != const0_rtx) | |
c71ebae3 | 1384 | { |
7209f1f9 DE |
1385 | rtx tem1, tem2; |
1386 | ||
1387 | tem1 = expand_and (uval, target, NULL_RTX); | |
1388 | if (GET_CODE (cval) == CONST_INT | |
1389 | && GET_CODE (uval) == CONST_INT | |
1390 | && (INTVAL (cval) & INTVAL (uval)) == INTVAL (cval)) | |
1391 | tem2 = cval; | |
1392 | else | |
1393 | { | |
1394 | tem2 = expand_unop (GET_MODE (var), one_cmpl_optab, | |
1395 | target, NULL_RTX, 0); | |
1396 | tem2 = expand_and (cval, tem2, | |
1397 | (GET_CODE (tem2) == REG | |
1398 | ? tem2 : 0)); | |
1399 | } | |
1400 | ||
1401 | /* If we usually make new pseudos, do so here. This | |
1402 | turns out to help machines that have conditional | |
1403 | move insns. */ | |
1404 | /* ??? Conditional moves have already been handled. | |
1405 | This may be obsolete. */ | |
1406 | ||
1407 | if (flag_expensive_optimizations) | |
1408 | target = 0; | |
1409 | ||
1410 | target = expand_binop (GET_MODE (var), ior_optab, | |
1411 | tem1, tem2, target, | |
1412 | 1, OPTAB_WIDEN); | |
c71ebae3 | 1413 | } |
7209f1f9 DE |
1414 | else if (normalizep != 1) |
1415 | { | |
1416 | /* We know that either CVAL or UVAL is zero. If | |
1417 | UVAL is zero, negate TARGET and `and' with CVAL. | |
1418 | Otherwise, `and' with UVAL. */ | |
1419 | if (uval == const0_rtx) | |
1420 | { | |
1421 | target = expand_unop (GET_MODE (var), one_cmpl_optab, | |
1422 | target, NULL_RTX, 0); | |
1423 | uval = cval; | |
1424 | } | |
c71ebae3 | 1425 | |
7209f1f9 DE |
1426 | target = expand_and (uval, target, |
1427 | (GET_CODE (target) == REG | |
1428 | && ! preserve_subexpressions_p () | |
1429 | ? target : NULL_RTX)); | |
1430 | } | |
3915de94 | 1431 | |
7209f1f9 DE |
1432 | emit_move_insn (var, target); |
1433 | seq = get_insns (); | |
1434 | end_sequence (); | |
01ca1b91 | 1435 | #ifdef HAVE_cc0 |
7209f1f9 DE |
1436 | /* If INSN uses CC0, we must not separate it from the |
1437 | insn that sets cc0. */ | |
1438 | if (reg_mentioned_p (cc0_rtx, PATTERN (before))) | |
1439 | before = prev_nonnote_insn (before); | |
01ca1b91 | 1440 | #endif |
7209f1f9 | 1441 | emit_insns_before (seq, before); |
01ca1b91 | 1442 | |
7209f1f9 DE |
1443 | delete_insn (temp); |
1444 | next = NEXT_INSN (insn); | |
1445 | delete_jump (insn); | |
1446 | changed = 1; | |
1447 | continue; | |
1448 | } | |
1449 | else | |
1450 | end_sequence (); | |
15a63be1 | 1451 | } |
15a63be1 RK |
1452 | } |
1453 | ||
1454 | /* If branches are expensive, convert | |
1455 | if (foo) bar++; to bar += (foo != 0); | |
1456 | and similarly for "bar--;" | |
1457 | ||
1458 | INSN is the conditional branch around the arithmetic. We set: | |
1459 | ||
1460 | TEMP is the arithmetic insn. | |
6dc42e49 | 1461 | TEMP1 is the SET doing the arithmetic. |
15a63be1 RK |
1462 | TEMP2 is the operand being incremented or decremented. |
1463 | TEMP3 to the condition being tested. | |
1464 | TEMP4 to the earliest insn used to find the condition. */ | |
1465 | ||
a8d916d3 | 1466 | if ((BRANCH_COST >= 2 |
48f16828 | 1467 | #ifdef HAVE_incscc |
a8d916d3 | 1468 | || HAVE_incscc |
48f16828 RK |
1469 | #endif |
1470 | #ifdef HAVE_decscc | |
d3907945 | 1471 | || HAVE_decscc |
a8d916d3 JL |
1472 | #endif |
1473 | ) | |
15a63be1 RK |
1474 | && ! reload_completed |
1475 | && this_is_condjump && ! this_is_simplejump | |
1476 | && (temp = next_nonnote_insn (insn)) != 0 | |
1477 | && (temp1 = single_set (temp)) != 0 | |
1478 | && (temp2 = SET_DEST (temp1), | |
1479 | GET_MODE_CLASS (GET_MODE (temp2)) == MODE_INT) | |
1480 | && GET_CODE (SET_SRC (temp1)) == PLUS | |
1481 | && (XEXP (SET_SRC (temp1), 1) == const1_rtx | |
1482 | || XEXP (SET_SRC (temp1), 1) == constm1_rtx) | |
1483 | && rtx_equal_p (temp2, XEXP (SET_SRC (temp1), 0)) | |
8743ede9 RK |
1484 | && ! side_effects_p (temp2) |
1485 | && ! may_trap_p (temp2) | |
15a63be1 RK |
1486 | /* INSN must either branch to the insn after TEMP or the insn |
1487 | after TEMP must branch to the same place as INSN. */ | |
1488 | && (reallabelprev == temp | |
1489 | || ((temp3 = next_active_insn (temp)) != 0 | |
1490 | && simplejump_p (temp3) | |
1491 | && JUMP_LABEL (temp3) == JUMP_LABEL (insn))) | |
1492 | && (temp3 = get_condition (insn, &temp4)) != 0 | |
7124e1e5 RS |
1493 | /* We must be comparing objects whose modes imply the size. |
1494 | We could handle BLKmode if (1) emit_store_flag could | |
1495 | and (2) we could find the size reliably. */ | |
1496 | && GET_MODE (XEXP (temp3, 0)) != BLKmode | |
15a63be1 RK |
1497 | && can_reverse_comparison_p (temp3, insn)) |
1498 | { | |
626d0d1d | 1499 | rtx temp6, target = 0, seq, init_insn = 0, init = temp2; |
15a63be1 RK |
1500 | enum rtx_code code = reverse_condition (GET_CODE (temp3)); |
1501 | ||
1502 | start_sequence (); | |
1503 | ||
626d0d1d RK |
1504 | /* It must be the case that TEMP2 is not modified in the range |
1505 | [TEMP4, INSN). The one exception we make is if the insn | |
1506 | before INSN sets TEMP2 to something which is also unchanged | |
1507 | in that range. In that case, we can move the initialization | |
1508 | into our sequence. */ | |
1509 | ||
1510 | if ((temp5 = prev_active_insn (insn)) != 0 | |
19f5ce60 | 1511 | && no_labels_between_p (temp5, insn) |
626d0d1d RK |
1512 | && GET_CODE (temp5) == INSN |
1513 | && (temp6 = single_set (temp5)) != 0 | |
1514 | && rtx_equal_p (temp2, SET_DEST (temp6)) | |
1515 | && (CONSTANT_P (SET_SRC (temp6)) | |
1516 | || GET_CODE (SET_SRC (temp6)) == REG | |
1517 | || GET_CODE (SET_SRC (temp6)) == SUBREG)) | |
1518 | { | |
1519 | emit_insn (PATTERN (temp5)); | |
1520 | init_insn = temp5; | |
1521 | init = SET_SRC (temp6); | |
1522 | } | |
1523 | ||
1524 | if (CONSTANT_P (init) | |
1525 | || ! reg_set_between_p (init, PREV_INSN (temp4), insn)) | |
1526 | target = emit_store_flag (gen_reg_rtx (GET_MODE (temp2)), code, | |
1527 | XEXP (temp3, 0), XEXP (temp3, 1), | |
1528 | VOIDmode, | |
1529 | (code == LTU || code == LEU | |
1530 | || code == GTU || code == GEU), 1); | |
15a63be1 RK |
1531 | |
1532 | /* If we can do the store-flag, do the addition or | |
1533 | subtraction. */ | |
1534 | ||
1535 | if (target) | |
1536 | target = expand_binop (GET_MODE (temp2), | |
1537 | (XEXP (SET_SRC (temp1), 1) == const1_rtx | |
1538 | ? add_optab : sub_optab), | |
58f066d1 | 1539 | temp2, target, temp2, 0, OPTAB_WIDEN); |
15a63be1 RK |
1540 | |
1541 | if (target != 0) | |
1542 | { | |
1543 | /* Put the result back in temp2 in case it isn't already. | |
1544 | Then replace the jump, possible a CC0-setting insn in | |
1545 | front of the jump, and TEMP, with the sequence we have | |
1546 | made. */ | |
1547 | ||
1548 | if (target != temp2) | |
1549 | emit_move_insn (temp2, target); | |
1550 | ||
1551 | seq = get_insns (); | |
1552 | end_sequence (); | |
1553 | ||
1554 | emit_insns_before (seq, temp4); | |
1555 | delete_insn (temp); | |
626d0d1d RK |
1556 | |
1557 | if (init_insn) | |
1558 | delete_insn (init_insn); | |
1559 | ||
15a63be1 RK |
1560 | next = NEXT_INSN (insn); |
1561 | #ifdef HAVE_cc0 | |
1562 | delete_insn (prev_nonnote_insn (insn)); | |
1563 | #endif | |
1564 | delete_insn (insn); | |
1565 | changed = 1; | |
1566 | continue; | |
1567 | } | |
1568 | else | |
1569 | end_sequence (); | |
1570 | } | |
1571 | ||
1572 | /* Simplify if (...) x = 1; else {...} if (x) ... | |
1573 | We recognize this case scanning backwards as well. | |
1574 | ||
1575 | TEMP is the assignment to x; | |
1576 | TEMP1 is the label at the head of the second if. */ | |
1577 | /* ?? This should call get_condition to find the values being | |
1578 | compared, instead of looking for a COMPARE insn when HAVE_cc0 | |
1579 | is not defined. This would allow it to work on the m88k. */ | |
1580 | /* ?? This optimization is only safe before cse is run if HAVE_cc0 | |
1581 | is not defined and the condition is tested by a separate compare | |
1582 | insn. This is because the code below assumes that the result | |
1583 | of the compare dies in the following branch. | |
1584 | ||
1585 | Not only that, but there might be other insns between the | |
1586 | compare and branch whose results are live. Those insns need | |
1587 | to be executed. | |
1588 | ||
1589 | A way to fix this is to move the insns at JUMP_LABEL (insn) | |
1590 | to before INSN. If we are running before flow, they will | |
1591 | be deleted if they aren't needed. But this doesn't work | |
1592 | well after flow. | |
1593 | ||
1594 | This is really a special-case of jump threading, anyway. The | |
1595 | right thing to do is to replace this and jump threading with | |
1596 | much simpler code in cse. | |
1597 | ||
1598 | This code has been turned off in the non-cc0 case in the | |
1599 | meantime. */ | |
1600 | ||
1601 | #ifdef HAVE_cc0 | |
1602 | else if (this_is_simplejump | |
1603 | /* Safe to skip USE and CLOBBER insns here | |
1604 | since they will not be deleted. */ | |
1605 | && (temp = prev_active_insn (insn)) | |
1606 | && no_labels_between_p (temp, insn) | |
1607 | && GET_CODE (temp) == INSN | |
1608 | && GET_CODE (PATTERN (temp)) == SET | |
1609 | && GET_CODE (SET_DEST (PATTERN (temp))) == REG | |
1610 | && CONSTANT_P (SET_SRC (PATTERN (temp))) | |
1611 | && (temp1 = next_active_insn (JUMP_LABEL (insn))) | |
1612 | /* If we find that the next value tested is `x' | |
1613 | (TEMP1 is the insn where this happens), win. */ | |
1614 | && GET_CODE (temp1) == INSN | |
1615 | && GET_CODE (PATTERN (temp1)) == SET | |
1616 | #ifdef HAVE_cc0 | |
1617 | /* Does temp1 `tst' the value of x? */ | |
1618 | && SET_SRC (PATTERN (temp1)) == SET_DEST (PATTERN (temp)) | |
1619 | && SET_DEST (PATTERN (temp1)) == cc0_rtx | |
1620 | && (temp1 = next_nonnote_insn (temp1)) | |
1621 | #else | |
1622 | /* Does temp1 compare the value of x against zero? */ | |
1623 | && GET_CODE (SET_SRC (PATTERN (temp1))) == COMPARE | |
1624 | && XEXP (SET_SRC (PATTERN (temp1)), 1) == const0_rtx | |
1625 | && (XEXP (SET_SRC (PATTERN (temp1)), 0) | |
1626 | == SET_DEST (PATTERN (temp))) | |
1627 | && GET_CODE (SET_DEST (PATTERN (temp1))) == REG | |
1628 | && (temp1 = find_next_ref (SET_DEST (PATTERN (temp1)), temp1)) | |
1629 | #endif | |
1630 | && condjump_p (temp1)) | |
1631 | { | |
1632 | /* Get the if_then_else from the condjump. */ | |
1633 | rtx choice = SET_SRC (PATTERN (temp1)); | |
1634 | if (GET_CODE (choice) == IF_THEN_ELSE) | |
1635 | { | |
1636 | enum rtx_code code = GET_CODE (XEXP (choice, 0)); | |
1637 | rtx val = SET_SRC (PATTERN (temp)); | |
1638 | rtx cond | |
1639 | = simplify_relational_operation (code, GET_MODE (SET_DEST (PATTERN (temp))), | |
1640 | val, const0_rtx); | |
1641 | rtx ultimate; | |
1642 | ||
1643 | if (cond == const_true_rtx) | |
1644 | ultimate = XEXP (choice, 1); | |
1645 | else if (cond == const0_rtx) | |
1646 | ultimate = XEXP (choice, 2); | |
1647 | else | |
1648 | ultimate = 0; | |
1649 | ||
1650 | if (ultimate == pc_rtx) | |
1651 | ultimate = get_label_after (temp1); | |
1652 | else if (ultimate && GET_CODE (ultimate) != RETURN) | |
1653 | ultimate = XEXP (ultimate, 0); | |
1654 | ||
9e390837 | 1655 | if (ultimate && JUMP_LABEL(insn) != ultimate) |
15a63be1 RK |
1656 | changed |= redirect_jump (insn, ultimate); |
1657 | } | |
1658 | } | |
1659 | #endif | |
1660 | ||
1661 | #if 0 | |
1662 | /* @@ This needs a bit of work before it will be right. | |
1663 | ||
1664 | Any type of comparison can be accepted for the first and | |
1665 | second compare. When rewriting the first jump, we must | |
1666 | compute the what conditions can reach label3, and use the | |
1667 | appropriate code. We can not simply reverse/swap the code | |
1668 | of the first jump. In some cases, the second jump must be | |
1669 | rewritten also. | |
1670 | ||
1671 | For example, | |
1672 | < == converts to > == | |
1673 | < != converts to == > | |
1674 | etc. | |
1675 | ||
1676 | If the code is written to only accept an '==' test for the second | |
1677 | compare, then all that needs to be done is to swap the condition | |
1678 | of the first branch. | |
1679 | ||
1680 | It is questionable whether we want this optimization anyways, | |
1681 | since if the user wrote code like this because he/she knew that | |
6dc42e49 | 1682 | the jump to label1 is taken most of the time, then rewriting |
15a63be1 RK |
1683 | this gives slower code. */ |
1684 | /* @@ This should call get_condition to find the values being | |
1685 | compared, instead of looking for a COMPARE insn when HAVE_cc0 | |
1686 | is not defined. This would allow it to work on the m88k. */ | |
1687 | /* @@ This optimization is only safe before cse is run if HAVE_cc0 | |
1688 | is not defined and the condition is tested by a separate compare | |
1689 | insn. This is because the code below assumes that the result | |
1690 | of the compare dies in the following branch. */ | |
1691 | ||
1692 | /* Simplify test a ~= b | |
1693 | condjump label1; | |
1694 | test a == b | |
1695 | condjump label2; | |
1696 | jump label3; | |
1697 | label1: | |
1698 | ||
1699 | rewriting as | |
1700 | test a ~~= b | |
1701 | condjump label3 | |
1702 | test a == b | |
1703 | condjump label2 | |
1704 | label1: | |
1705 | ||
1706 | where ~= is an inequality, e.g. >, and ~~= is the swapped | |
1707 | inequality, e.g. <. | |
1708 | ||
1709 | We recognize this case scanning backwards. | |
1710 | ||
1711 | TEMP is the conditional jump to `label2'; | |
1712 | TEMP1 is the test for `a == b'; | |
1713 | TEMP2 is the conditional jump to `label1'; | |
1714 | TEMP3 is the test for `a ~= b'. */ | |
1715 | else if (this_is_simplejump | |
1716 | && (temp = prev_active_insn (insn)) | |
1717 | && no_labels_between_p (temp, insn) | |
1718 | && condjump_p (temp) | |
1719 | && (temp1 = prev_active_insn (temp)) | |
1720 | && no_labels_between_p (temp1, temp) | |
1721 | && GET_CODE (temp1) == INSN | |
1722 | && GET_CODE (PATTERN (temp1)) == SET | |
1723 | #ifdef HAVE_cc0 | |
1724 | && sets_cc0_p (PATTERN (temp1)) == 1 | |
1725 | #else | |
1726 | && GET_CODE (SET_SRC (PATTERN (temp1))) == COMPARE | |
1727 | && GET_CODE (SET_DEST (PATTERN (temp1))) == REG | |
1728 | && (temp == find_next_ref (SET_DEST (PATTERN (temp1)), temp1)) | |
1729 | #endif | |
1730 | && (temp2 = prev_active_insn (temp1)) | |
1731 | && no_labels_between_p (temp2, temp1) | |
1732 | && condjump_p (temp2) | |
1733 | && JUMP_LABEL (temp2) == next_nonnote_insn (NEXT_INSN (insn)) | |
1734 | && (temp3 = prev_active_insn (temp2)) | |
1735 | && no_labels_between_p (temp3, temp2) | |
1736 | && GET_CODE (PATTERN (temp3)) == SET | |
1737 | && rtx_equal_p (SET_DEST (PATTERN (temp3)), | |
1738 | SET_DEST (PATTERN (temp1))) | |
1739 | && rtx_equal_p (SET_SRC (PATTERN (temp1)), | |
1740 | SET_SRC (PATTERN (temp3))) | |
1741 | && ! inequality_comparisons_p (PATTERN (temp)) | |
1742 | && inequality_comparisons_p (PATTERN (temp2))) | |
1743 | { | |
1744 | rtx fallthrough_label = JUMP_LABEL (temp2); | |
1745 | ||
1746 | ++LABEL_NUSES (fallthrough_label); | |
1747 | if (swap_jump (temp2, JUMP_LABEL (insn))) | |
1748 | { | |
1749 | delete_insn (insn); | |
1750 | changed = 1; | |
1751 | } | |
1752 | ||
1753 | if (--LABEL_NUSES (fallthrough_label) == 0) | |
1754 | delete_insn (fallthrough_label); | |
1755 | } | |
1756 | #endif | |
1757 | /* Simplify if (...) {... x = 1;} if (x) ... | |
1758 | ||
1759 | We recognize this case backwards. | |
1760 | ||
1761 | TEMP is the test of `x'; | |
1762 | TEMP1 is the assignment to `x' at the end of the | |
1763 | previous statement. */ | |
1764 | /* @@ This should call get_condition to find the values being | |
1765 | compared, instead of looking for a COMPARE insn when HAVE_cc0 | |
1766 | is not defined. This would allow it to work on the m88k. */ | |
1767 | /* @@ This optimization is only safe before cse is run if HAVE_cc0 | |
1768 | is not defined and the condition is tested by a separate compare | |
1769 | insn. This is because the code below assumes that the result | |
1770 | of the compare dies in the following branch. */ | |
2d20b9df RS |
1771 | |
1772 | /* ??? This has to be turned off. The problem is that the | |
1773 | unconditional jump might indirectly end up branching to the | |
1774 | label between TEMP1 and TEMP. We can't detect this, in general, | |
1775 | since it may become a jump to there after further optimizations. | |
1776 | If that jump is done, it will be deleted, so we will retry | |
1777 | this optimization in the next pass, thus an infinite loop. | |
1778 | ||
1779 | The present code prevents this by putting the jump after the | |
1780 | label, but this is not logically correct. */ | |
1781 | #if 0 | |
15a63be1 RK |
1782 | else if (this_is_condjump |
1783 | /* Safe to skip USE and CLOBBER insns here | |
1784 | since they will not be deleted. */ | |
1785 | && (temp = prev_active_insn (insn)) | |
1786 | && no_labels_between_p (temp, insn) | |
1787 | && GET_CODE (temp) == INSN | |
1788 | && GET_CODE (PATTERN (temp)) == SET | |
1789 | #ifdef HAVE_cc0 | |
1790 | && sets_cc0_p (PATTERN (temp)) == 1 | |
1791 | && GET_CODE (SET_SRC (PATTERN (temp))) == REG | |
1792 | #else | |
1793 | /* Temp must be a compare insn, we can not accept a register | |
1794 | to register move here, since it may not be simply a | |
1795 | tst insn. */ | |
1796 | && GET_CODE (SET_SRC (PATTERN (temp))) == COMPARE | |
1797 | && XEXP (SET_SRC (PATTERN (temp)), 1) == const0_rtx | |
1798 | && GET_CODE (XEXP (SET_SRC (PATTERN (temp)), 0)) == REG | |
1799 | && GET_CODE (SET_DEST (PATTERN (temp))) == REG | |
1800 | && insn == find_next_ref (SET_DEST (PATTERN (temp)), temp) | |
1801 | #endif | |
1802 | /* May skip USE or CLOBBER insns here | |
1803 | for checking for opportunity, since we | |
1804 | take care of them later. */ | |
1805 | && (temp1 = prev_active_insn (temp)) | |
1806 | && GET_CODE (temp1) == INSN | |
1807 | && GET_CODE (PATTERN (temp1)) == SET | |
1808 | #ifdef HAVE_cc0 | |
1809 | && SET_SRC (PATTERN (temp)) == SET_DEST (PATTERN (temp1)) | |
1810 | #else | |
1811 | && (XEXP (SET_SRC (PATTERN (temp)), 0) | |
1812 | == SET_DEST (PATTERN (temp1))) | |
1813 | #endif | |
1814 | && CONSTANT_P (SET_SRC (PATTERN (temp1))) | |
1815 | /* If this isn't true, cse will do the job. */ | |
1816 | && ! no_labels_between_p (temp1, temp)) | |
1817 | { | |
1818 | /* Get the if_then_else from the condjump. */ | |
1819 | rtx choice = SET_SRC (PATTERN (insn)); | |
1820 | if (GET_CODE (choice) == IF_THEN_ELSE | |
1821 | && (GET_CODE (XEXP (choice, 0)) == EQ | |
1822 | || GET_CODE (XEXP (choice, 0)) == NE)) | |
1823 | { | |
1824 | int want_nonzero = (GET_CODE (XEXP (choice, 0)) == NE); | |
1825 | rtx last_insn; | |
1826 | rtx ultimate; | |
1827 | rtx p; | |
1828 | ||
1829 | /* Get the place that condjump will jump to | |
1830 | if it is reached from here. */ | |
1831 | if ((SET_SRC (PATTERN (temp1)) != const0_rtx) | |
1832 | == want_nonzero) | |
1833 | ultimate = XEXP (choice, 1); | |
1834 | else | |
1835 | ultimate = XEXP (choice, 2); | |
1836 | /* Get it as a CODE_LABEL. */ | |
1837 | if (ultimate == pc_rtx) | |
1838 | ultimate = get_label_after (insn); | |
1839 | else | |
1840 | /* Get the label out of the LABEL_REF. */ | |
1841 | ultimate = XEXP (ultimate, 0); | |
1842 | ||
2d20b9df RS |
1843 | /* Insert the jump immediately before TEMP, specifically |
1844 | after the label that is between TEMP1 and TEMP. */ | |
1845 | last_insn = PREV_INSN (temp); | |
15a63be1 RK |
1846 | |
1847 | /* If we would be branching to the next insn, the jump | |
1848 | would immediately be deleted and the re-inserted in | |
1849 | a subsequent pass over the code. So don't do anything | |
1850 | in that case. */ | |
1851 | if (next_active_insn (last_insn) | |
1852 | != next_active_insn (ultimate)) | |
1853 | { | |
1854 | emit_barrier_after (last_insn); | |
1855 | p = emit_jump_insn_after (gen_jump (ultimate), | |
1856 | last_insn); | |
1857 | JUMP_LABEL (p) = ultimate; | |
1858 | ++LABEL_NUSES (ultimate); | |
1859 | if (INSN_UID (ultimate) < max_jump_chain | |
1860 | && INSN_CODE (p) < max_jump_chain) | |
1861 | { | |
1862 | jump_chain[INSN_UID (p)] | |
1863 | = jump_chain[INSN_UID (ultimate)]; | |
1864 | jump_chain[INSN_UID (ultimate)] = p; | |
1865 | } | |
1866 | changed = 1; | |
1867 | continue; | |
1868 | } | |
1869 | } | |
1870 | } | |
2d20b9df | 1871 | #endif |
15a63be1 RK |
1872 | /* Detect a conditional jump going to the same place |
1873 | as an immediately following unconditional jump. */ | |
1874 | else if (this_is_condjump | |
1875 | && (temp = next_active_insn (insn)) != 0 | |
1876 | && simplejump_p (temp) | |
1877 | && (next_active_insn (JUMP_LABEL (insn)) | |
1878 | == next_active_insn (JUMP_LABEL (temp)))) | |
1879 | { | |
f6a6a1b3 DE |
1880 | rtx tem = temp; |
1881 | ||
1882 | /* ??? Optional. Disables some optimizations, but makes | |
1883 | gcov output more accurate with -O. */ | |
1884 | if (flag_test_coverage && !reload_completed) | |
1885 | for (tem = insn; tem != temp; tem = NEXT_INSN (tem)) | |
1886 | if (GET_CODE (tem) == NOTE && NOTE_LINE_NUMBER (tem) > 0) | |
1887 | break; | |
1888 | ||
1889 | if (tem == temp) | |
1890 | { | |
1891 | delete_jump (insn); | |
1892 | changed = 1; | |
1893 | continue; | |
1894 | } | |
15a63be1 RK |
1895 | } |
1896 | /* Detect a conditional jump jumping over an unconditional jump. */ | |
1897 | ||
3480bb98 JL |
1898 | else if ((this_is_condjump || this_is_condjump_in_parallel) |
1899 | && ! this_is_simplejump | |
15a63be1 RK |
1900 | && reallabelprev != 0 |
1901 | && GET_CODE (reallabelprev) == JUMP_INSN | |
1902 | && prev_active_insn (reallabelprev) == insn | |
1903 | && no_labels_between_p (insn, reallabelprev) | |
1904 | && simplejump_p (reallabelprev)) | |
1905 | { | |
1906 | /* When we invert the unconditional jump, we will be | |
1907 | decrementing the usage count of its old label. | |
1908 | Make sure that we don't delete it now because that | |
1909 | might cause the following code to be deleted. */ | |
1910 | rtx prev_uses = prev_nonnote_insn (reallabelprev); | |
1911 | rtx prev_label = JUMP_LABEL (insn); | |
1912 | ||
e26a82e4 JW |
1913 | if (prev_label) |
1914 | ++LABEL_NUSES (prev_label); | |
15a63be1 RK |
1915 | |
1916 | if (invert_jump (insn, JUMP_LABEL (reallabelprev))) | |
1917 | { | |
1918 | /* It is very likely that if there are USE insns before | |
1919 | this jump, they hold REG_DEAD notes. These REG_DEAD | |
1920 | notes are no longer valid due to this optimization, | |
1921 | and will cause the life-analysis that following passes | |
1922 | (notably delayed-branch scheduling) to think that | |
1923 | these registers are dead when they are not. | |
1924 | ||
1925 | To prevent this trouble, we just remove the USE insns | |
1926 | from the insn chain. */ | |
1927 | ||
1928 | while (prev_uses && GET_CODE (prev_uses) == INSN | |
1929 | && GET_CODE (PATTERN (prev_uses)) == USE) | |
1930 | { | |
1931 | rtx useless = prev_uses; | |
1932 | prev_uses = prev_nonnote_insn (prev_uses); | |
1933 | delete_insn (useless); | |
1934 | } | |
1935 | ||
1936 | delete_insn (reallabelprev); | |
1937 | next = insn; | |
1938 | changed = 1; | |
1939 | } | |
1940 | ||
1941 | /* We can now safely delete the label if it is unreferenced | |
1942 | since the delete_insn above has deleted the BARRIER. */ | |
e26a82e4 | 1943 | if (prev_label && --LABEL_NUSES (prev_label) == 0) |
15a63be1 RK |
1944 | delete_insn (prev_label); |
1945 | continue; | |
1946 | } | |
1947 | else | |
1948 | { | |
1949 | /* Detect a jump to a jump. */ | |
1950 | ||
1951 | nlabel = follow_jumps (JUMP_LABEL (insn)); | |
1952 | if (nlabel != JUMP_LABEL (insn) | |
1953 | && redirect_jump (insn, nlabel)) | |
1954 | { | |
1955 | changed = 1; | |
1956 | next = insn; | |
1957 | } | |
1958 | ||
1959 | /* Look for if (foo) bar; else break; */ | |
1960 | /* The insns look like this: | |
1961 | insn = condjump label1; | |
1962 | ...range1 (some insns)... | |
1963 | jump label2; | |
1964 | label1: | |
1965 | ...range2 (some insns)... | |
1966 | jump somewhere unconditionally | |
1967 | label2: */ | |
1968 | { | |
1969 | rtx label1 = next_label (insn); | |
1970 | rtx range1end = label1 ? prev_active_insn (label1) : 0; | |
1971 | /* Don't do this optimization on the first round, so that | |
1972 | jump-around-a-jump gets simplified before we ask here | |
1973 | whether a jump is unconditional. | |
1974 | ||
1975 | Also don't do it when we are called after reload since | |
1976 | it will confuse reorg. */ | |
1977 | if (! first | |
1978 | && (reload_completed ? ! flag_delayed_branch : 1) | |
1979 | /* Make sure INSN is something we can invert. */ | |
1980 | && condjump_p (insn) | |
1981 | && label1 != 0 | |
1982 | && JUMP_LABEL (insn) == label1 | |
1983 | && LABEL_NUSES (label1) == 1 | |
1984 | && GET_CODE (range1end) == JUMP_INSN | |
1985 | && simplejump_p (range1end)) | |
1986 | { | |
1987 | rtx label2 = next_label (label1); | |
1988 | rtx range2end = label2 ? prev_active_insn (label2) : 0; | |
1989 | if (range1end != range2end | |
1990 | && JUMP_LABEL (range1end) == label2 | |
1991 | && GET_CODE (range2end) == JUMP_INSN | |
1992 | && GET_CODE (NEXT_INSN (range2end)) == BARRIER | |
1993 | /* Invert the jump condition, so we | |
1994 | still execute the same insns in each case. */ | |
1995 | && invert_jump (insn, label1)) | |
1996 | { | |
1997 | rtx range1beg = next_active_insn (insn); | |
1998 | rtx range2beg = next_active_insn (label1); | |
1999 | rtx range1after, range2after; | |
2000 | rtx range1before, range2before; | |
f0e1b9a9 | 2001 | rtx rangenext; |
15a63be1 | 2002 | |
1f109a14 JW |
2003 | /* Include in each range any notes before it, to be |
2004 | sure that we get the line number note if any, even | |
2005 | if there are other notes here. */ | |
0e690bdb | 2006 | while (PREV_INSN (range1beg) |
1f109a14 | 2007 | && GET_CODE (PREV_INSN (range1beg)) == NOTE) |
0e690bdb RS |
2008 | range1beg = PREV_INSN (range1beg); |
2009 | ||
2010 | while (PREV_INSN (range2beg) | |
1f109a14 | 2011 | && GET_CODE (PREV_INSN (range2beg)) == NOTE) |
0e690bdb RS |
2012 | range2beg = PREV_INSN (range2beg); |
2013 | ||
15a63be1 RK |
2014 | /* Don't move NOTEs for blocks or loops; shift them |
2015 | outside the ranges, where they'll stay put. */ | |
915f619f JW |
2016 | range1beg = squeeze_notes (range1beg, range1end); |
2017 | range2beg = squeeze_notes (range2beg, range2end); | |
15a63be1 RK |
2018 | |
2019 | /* Get current surrounds of the 2 ranges. */ | |
2020 | range1before = PREV_INSN (range1beg); | |
2021 | range2before = PREV_INSN (range2beg); | |
2022 | range1after = NEXT_INSN (range1end); | |
2023 | range2after = NEXT_INSN (range2end); | |
2024 | ||
2025 | /* Splice range2 where range1 was. */ | |
2026 | NEXT_INSN (range1before) = range2beg; | |
2027 | PREV_INSN (range2beg) = range1before; | |
2028 | NEXT_INSN (range2end) = range1after; | |
2029 | PREV_INSN (range1after) = range2end; | |
2030 | /* Splice range1 where range2 was. */ | |
2031 | NEXT_INSN (range2before) = range1beg; | |
2032 | PREV_INSN (range1beg) = range2before; | |
2033 | NEXT_INSN (range1end) = range2after; | |
2034 | PREV_INSN (range2after) = range1end; | |
f0e1b9a9 RE |
2035 | |
2036 | /* Check for a loop end note between the end of | |
2037 | range2, and the next code label. If there is one, | |
2038 | then what we have really seen is | |
2039 | if (foo) break; end_of_loop; | |
2040 | and moved the break sequence outside the loop. | |
2041 | We must move the LOOP_END note to where the | |
2042 | loop really ends now, or we will confuse loop | |
ca188f16 JW |
2043 | optimization. Stop if we find a LOOP_BEG note |
2044 | first, since we don't want to move the LOOP_END | |
2045 | note in that case. */ | |
f0e1b9a9 RE |
2046 | for (;range2after != label2; range2after = rangenext) |
2047 | { | |
2048 | rangenext = NEXT_INSN (range2after); | |
ca188f16 | 2049 | if (GET_CODE (range2after) == NOTE) |
f0e1b9a9 | 2050 | { |
ca188f16 JW |
2051 | if (NOTE_LINE_NUMBER (range2after) |
2052 | == NOTE_INSN_LOOP_END) | |
2053 | { | |
2054 | NEXT_INSN (PREV_INSN (range2after)) | |
2055 | = rangenext; | |
2056 | PREV_INSN (rangenext) | |
2057 | = PREV_INSN (range2after); | |
2058 | PREV_INSN (range2after) | |
2059 | = PREV_INSN (range1beg); | |
2060 | NEXT_INSN (range2after) = range1beg; | |
2061 | NEXT_INSN (PREV_INSN (range1beg)) | |
2062 | = range2after; | |
2063 | PREV_INSN (range1beg) = range2after; | |
2064 | } | |
2065 | else if (NOTE_LINE_NUMBER (range2after) | |
2066 | == NOTE_INSN_LOOP_BEG) | |
2067 | break; | |
f0e1b9a9 RE |
2068 | } |
2069 | } | |
15a63be1 RK |
2070 | changed = 1; |
2071 | continue; | |
2072 | } | |
2073 | } | |
2074 | } | |
2075 | ||
2076 | /* Now that the jump has been tensioned, | |
2077 | try cross jumping: check for identical code | |
0f41302f | 2078 | before the jump and before its target label. */ |
15a63be1 RK |
2079 | |
2080 | /* First, cross jumping of conditional jumps: */ | |
2081 | ||
2082 | if (cross_jump && condjump_p (insn)) | |
2083 | { | |
2084 | rtx newjpos, newlpos; | |
2085 | rtx x = prev_real_insn (JUMP_LABEL (insn)); | |
2086 | ||
2087 | /* A conditional jump may be crossjumped | |
2088 | only if the place it jumps to follows | |
2089 | an opposing jump that comes back here. */ | |
2090 | ||
2091 | if (x != 0 && ! jump_back_p (x, insn)) | |
2092 | /* We have no opposing jump; | |
2093 | cannot cross jump this insn. */ | |
2094 | x = 0; | |
2095 | ||
2096 | newjpos = 0; | |
2097 | /* TARGET is nonzero if it is ok to cross jump | |
2098 | to code before TARGET. If so, see if matches. */ | |
2099 | if (x != 0) | |
2100 | find_cross_jump (insn, x, 2, | |
2101 | &newjpos, &newlpos); | |
2102 | ||
2103 | if (newjpos != 0) | |
2104 | { | |
2105 | do_cross_jump (insn, newjpos, newlpos); | |
2106 | /* Make the old conditional jump | |
2107 | into an unconditional one. */ | |
2108 | SET_SRC (PATTERN (insn)) | |
2109 | = gen_rtx (LABEL_REF, VOIDmode, JUMP_LABEL (insn)); | |
2110 | INSN_CODE (insn) = -1; | |
2111 | emit_barrier_after (insn); | |
2112 | /* Add to jump_chain unless this is a new label | |
0f41302f | 2113 | whose UID is too large. */ |
15a63be1 RK |
2114 | if (INSN_UID (JUMP_LABEL (insn)) < max_jump_chain) |
2115 | { | |
2116 | jump_chain[INSN_UID (insn)] | |
2117 | = jump_chain[INSN_UID (JUMP_LABEL (insn))]; | |
2118 | jump_chain[INSN_UID (JUMP_LABEL (insn))] = insn; | |
2119 | } | |
2120 | changed = 1; | |
2121 | next = insn; | |
2122 | } | |
2123 | } | |
2124 | ||
2125 | /* Cross jumping of unconditional jumps: | |
2126 | a few differences. */ | |
2127 | ||
2128 | if (cross_jump && simplejump_p (insn)) | |
2129 | { | |
2130 | rtx newjpos, newlpos; | |
2131 | rtx target; | |
2132 | ||
2133 | newjpos = 0; | |
2134 | ||
2135 | /* TARGET is nonzero if it is ok to cross jump | |
2136 | to code before TARGET. If so, see if matches. */ | |
2137 | find_cross_jump (insn, JUMP_LABEL (insn), 1, | |
2138 | &newjpos, &newlpos); | |
2139 | ||
2140 | /* If cannot cross jump to code before the label, | |
2141 | see if we can cross jump to another jump to | |
2142 | the same label. */ | |
2143 | /* Try each other jump to this label. */ | |
2144 | if (INSN_UID (JUMP_LABEL (insn)) < max_uid) | |
2145 | for (target = jump_chain[INSN_UID (JUMP_LABEL (insn))]; | |
2146 | target != 0 && newjpos == 0; | |
2147 | target = jump_chain[INSN_UID (target)]) | |
2148 | if (target != insn | |
2149 | && JUMP_LABEL (target) == JUMP_LABEL (insn) | |
2150 | /* Ignore TARGET if it's deleted. */ | |
2151 | && ! INSN_DELETED_P (target)) | |
2152 | find_cross_jump (insn, target, 2, | |
2153 | &newjpos, &newlpos); | |
2154 | ||
2155 | if (newjpos != 0) | |
2156 | { | |
2157 | do_cross_jump (insn, newjpos, newlpos); | |
2158 | changed = 1; | |
2159 | next = insn; | |
2160 | } | |
2161 | } | |
2162 | ||
2163 | /* This code was dead in the previous jump.c! */ | |
2164 | if (cross_jump && GET_CODE (PATTERN (insn)) == RETURN) | |
2165 | { | |
2166 | /* Return insns all "jump to the same place" | |
2167 | so we can cross-jump between any two of them. */ | |
2168 | ||
2169 | rtx newjpos, newlpos, target; | |
2170 | ||
2171 | newjpos = 0; | |
2172 | ||
2173 | /* If cannot cross jump to code before the label, | |
2174 | see if we can cross jump to another jump to | |
2175 | the same label. */ | |
2176 | /* Try each other jump to this label. */ | |
2177 | for (target = jump_chain[0]; | |
2178 | target != 0 && newjpos == 0; | |
2179 | target = jump_chain[INSN_UID (target)]) | |
2180 | if (target != insn | |
2181 | && ! INSN_DELETED_P (target) | |
2182 | && GET_CODE (PATTERN (target)) == RETURN) | |
2183 | find_cross_jump (insn, target, 2, | |
2184 | &newjpos, &newlpos); | |
2185 | ||
2186 | if (newjpos != 0) | |
2187 | { | |
2188 | do_cross_jump (insn, newjpos, newlpos); | |
2189 | changed = 1; | |
2190 | next = insn; | |
2191 | } | |
2192 | } | |
2193 | } | |
2194 | } | |
2195 | ||
2196 | first = 0; | |
2197 | } | |
2198 | ||
2199 | /* Delete extraneous line number notes. | |
2200 | Note that two consecutive notes for different lines are not really | |
2201 | extraneous. There should be some indication where that line belonged, | |
2202 | even if it became empty. */ | |
2203 | ||
2204 | { | |
2205 | rtx last_note = 0; | |
2206 | ||
2207 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
2208 | if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) >= 0) | |
2209 | { | |
2210 | /* Delete this note if it is identical to previous note. */ | |
2211 | if (last_note | |
2212 | && NOTE_SOURCE_FILE (insn) == NOTE_SOURCE_FILE (last_note) | |
2213 | && NOTE_LINE_NUMBER (insn) == NOTE_LINE_NUMBER (last_note)) | |
2214 | { | |
2215 | delete_insn (insn); | |
2216 | continue; | |
2217 | } | |
2218 | ||
2219 | last_note = insn; | |
2220 | } | |
2221 | } | |
2222 | ||
683e6ccd RK |
2223 | #ifdef HAVE_return |
2224 | if (HAVE_return) | |
2225 | { | |
2226 | /* If we fall through to the epilogue, see if we can insert a RETURN insn | |
2227 | in front of it. If the machine allows it at this point (we might be | |
2228 | after reload for a leaf routine), it will improve optimization for it | |
2229 | to be there. We do this both here and at the start of this pass since | |
2230 | the RETURN might have been deleted by some of our optimizations. */ | |
2231 | insn = get_last_insn (); | |
2232 | while (insn && GET_CODE (insn) == NOTE) | |
2233 | insn = PREV_INSN (insn); | |
2234 | ||
2235 | if (insn && GET_CODE (insn) != BARRIER) | |
2236 | { | |
2237 | emit_jump_insn (gen_return ()); | |
2238 | emit_barrier (); | |
2239 | } | |
2240 | } | |
2241 | #endif | |
2242 | ||
15a63be1 RK |
2243 | /* See if there is still a NOTE_INSN_FUNCTION_END in this function. |
2244 | If so, delete it, and record that this function can drop off the end. */ | |
2245 | ||
2246 | insn = last_insn; | |
2247 | { | |
2248 | int n_labels = 1; | |
2249 | while (insn | |
2250 | /* One label can follow the end-note: the return label. */ | |
2251 | && ((GET_CODE (insn) == CODE_LABEL && n_labels-- > 0) | |
2252 | /* Ordinary insns can follow it if returning a structure. */ | |
2253 | || GET_CODE (insn) == INSN | |
2254 | /* If machine uses explicit RETURN insns, no epilogue, | |
2255 | then one of them follows the note. */ | |
2256 | || (GET_CODE (insn) == JUMP_INSN | |
2257 | && GET_CODE (PATTERN (insn)) == RETURN) | |
60374599 DE |
2258 | /* A barrier can follow the return insn. */ |
2259 | || GET_CODE (insn) == BARRIER | |
15a63be1 RK |
2260 | /* Other kinds of notes can follow also. */ |
2261 | || (GET_CODE (insn) == NOTE | |
2262 | && NOTE_LINE_NUMBER (insn) != NOTE_INSN_FUNCTION_END))) | |
2263 | insn = PREV_INSN (insn); | |
2264 | } | |
2265 | ||
2266 | /* Report if control can fall through at the end of the function. */ | |
2267 | if (insn && GET_CODE (insn) == NOTE | |
2268 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_END) | |
2269 | { | |
2270 | can_reach_end = 1; | |
2271 | delete_insn (insn); | |
2272 | } | |
2273 | ||
2274 | /* Show JUMP_CHAIN no longer valid. */ | |
2275 | jump_chain = 0; | |
2276 | } | |
2277 | \f | |
2278 | /* LOOP_START is a NOTE_INSN_LOOP_BEG note that is followed by an unconditional | |
2279 | jump. Assume that this unconditional jump is to the exit test code. If | |
2280 | the code is sufficiently simple, make a copy of it before INSN, | |
2281 | followed by a jump to the exit of the loop. Then delete the unconditional | |
2282 | jump after INSN. | |
2283 | ||
15a63be1 RK |
2284 | Return 1 if we made the change, else 0. |
2285 | ||
2286 | This is only safe immediately after a regscan pass because it uses the | |
2287 | values of regno_first_uid and regno_last_uid. */ | |
2288 | ||
2289 | static int | |
2290 | duplicate_loop_exit_test (loop_start) | |
2291 | rtx loop_start; | |
2292 | { | |
e33477be | 2293 | rtx insn, set, reg, p, link; |
9c066566 | 2294 | rtx copy = 0; |
15a63be1 RK |
2295 | int num_insns = 0; |
2296 | rtx exitcode = NEXT_INSN (JUMP_LABEL (next_nonnote_insn (loop_start))); | |
2297 | rtx lastexit; | |
2298 | int max_reg = max_reg_num (); | |
2299 | rtx *reg_map = 0; | |
2300 | ||
2301 | /* Scan the exit code. We do not perform this optimization if any insn: | |
2302 | ||
2303 | is a CALL_INSN | |
2304 | is a CODE_LABEL | |
2305 | has a REG_RETVAL or REG_LIBCALL note (hard to adjust) | |
2306 | is a NOTE_INSN_LOOP_BEG because this means we have a nested loop | |
2307 | is a NOTE_INSN_BLOCK_{BEG,END} because duplicating these notes | |
2308 | are not valid | |
2309 | ||
2310 | Also, don't do this if the exit code is more than 20 insns. */ | |
2311 | ||
2312 | for (insn = exitcode; | |
2313 | insn | |
2314 | && ! (GET_CODE (insn) == NOTE | |
2315 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END); | |
2316 | insn = NEXT_INSN (insn)) | |
2317 | { | |
2318 | switch (GET_CODE (insn)) | |
2319 | { | |
2320 | case CODE_LABEL: | |
2321 | case CALL_INSN: | |
2322 | return 0; | |
2323 | case NOTE: | |
fe464caf RK |
2324 | /* We could be in front of the wrong NOTE_INSN_LOOP_END if there is |
2325 | a jump immediately after the loop start that branches outside | |
2326 | the loop but within an outer loop, near the exit test. | |
2327 | If we copied this exit test and created a phony | |
2328 | NOTE_INSN_LOOP_VTOP, this could make instructions immediately | |
2329 | before the exit test look like these could be safely moved | |
2330 | out of the loop even if they actually may be never executed. | |
2331 | This can be avoided by checking here for NOTE_INSN_LOOP_CONT. */ | |
2332 | ||
15a63be1 RK |
2333 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG |
2334 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG | |
fe464caf RK |
2335 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END |
2336 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_CONT) | |
15a63be1 RK |
2337 | return 0; |
2338 | break; | |
2339 | case JUMP_INSN: | |
2340 | case INSN: | |
2341 | if (++num_insns > 20 | |
5f4f0e22 CH |
2342 | || find_reg_note (insn, REG_RETVAL, NULL_RTX) |
2343 | || find_reg_note (insn, REG_LIBCALL, NULL_RTX)) | |
15a63be1 RK |
2344 | return 0; |
2345 | break; | |
e9a25f70 JL |
2346 | default: |
2347 | break; | |
15a63be1 RK |
2348 | } |
2349 | } | |
2350 | ||
2351 | /* Unless INSN is zero, we can do the optimization. */ | |
2352 | if (insn == 0) | |
2353 | return 0; | |
2354 | ||
2355 | lastexit = insn; | |
2356 | ||
2357 | /* See if any insn sets a register only used in the loop exit code and | |
2358 | not a user variable. If so, replace it with a new register. */ | |
2359 | for (insn = exitcode; insn != lastexit; insn = NEXT_INSN (insn)) | |
2360 | if (GET_CODE (insn) == INSN | |
2361 | && (set = single_set (insn)) != 0 | |
e33477be RK |
2362 | && ((reg = SET_DEST (set), GET_CODE (reg) == REG) |
2363 | || (GET_CODE (reg) == SUBREG | |
2364 | && (reg = SUBREG_REG (reg), GET_CODE (reg) == REG))) | |
2365 | && REGNO (reg) >= FIRST_PSEUDO_REGISTER | |
b1f21e0a | 2366 | && REGNO_FIRST_UID (REGNO (reg)) == INSN_UID (insn)) |
15a63be1 RK |
2367 | { |
2368 | for (p = NEXT_INSN (insn); p != lastexit; p = NEXT_INSN (p)) | |
b1f21e0a | 2369 | if (REGNO_LAST_UID (REGNO (reg)) == INSN_UID (p)) |
15a63be1 RK |
2370 | break; |
2371 | ||
2372 | if (p != lastexit) | |
2373 | { | |
2374 | /* We can do the replacement. Allocate reg_map if this is the | |
2375 | first replacement we found. */ | |
2376 | if (reg_map == 0) | |
2377 | { | |
2378 | reg_map = (rtx *) alloca (max_reg * sizeof (rtx)); | |
4c9a05bc | 2379 | bzero ((char *) reg_map, max_reg * sizeof (rtx)); |
15a63be1 RK |
2380 | } |
2381 | ||
e33477be | 2382 | REG_LOOP_TEST_P (reg) = 1; |
15a63be1 | 2383 | |
e33477be | 2384 | reg_map[REGNO (reg)] = gen_reg_rtx (GET_MODE (reg)); |
15a63be1 RK |
2385 | } |
2386 | } | |
2387 | ||
2388 | /* Now copy each insn. */ | |
2389 | for (insn = exitcode; insn != lastexit; insn = NEXT_INSN (insn)) | |
2390 | switch (GET_CODE (insn)) | |
2391 | { | |
2392 | case BARRIER: | |
2393 | copy = emit_barrier_before (loop_start); | |
2394 | break; | |
2395 | case NOTE: | |
2396 | /* Only copy line-number notes. */ | |
2397 | if (NOTE_LINE_NUMBER (insn) >= 0) | |
2398 | { | |
2399 | copy = emit_note_before (NOTE_LINE_NUMBER (insn), loop_start); | |
2400 | NOTE_SOURCE_FILE (copy) = NOTE_SOURCE_FILE (insn); | |
2401 | } | |
2402 | break; | |
2403 | ||
2404 | case INSN: | |
2405 | copy = emit_insn_before (copy_rtx (PATTERN (insn)), loop_start); | |
2406 | if (reg_map) | |
2407 | replace_regs (PATTERN (copy), reg_map, max_reg, 1); | |
2408 | ||
2409 | mark_jump_label (PATTERN (copy), copy, 0); | |
2410 | ||
2411 | /* Copy all REG_NOTES except REG_LABEL since mark_jump_label will | |
2412 | make them. */ | |
2413 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
2414 | if (REG_NOTE_KIND (link) != REG_LABEL) | |
2415 | REG_NOTES (copy) | |
2416 | = copy_rtx (gen_rtx (EXPR_LIST, REG_NOTE_KIND (link), | |
2417 | XEXP (link, 0), REG_NOTES (copy))); | |
2418 | if (reg_map && REG_NOTES (copy)) | |
2419 | replace_regs (REG_NOTES (copy), reg_map, max_reg, 1); | |
2420 | break; | |
2421 | ||
2422 | case JUMP_INSN: | |
2423 | copy = emit_jump_insn_before (copy_rtx (PATTERN (insn)), loop_start); | |
2424 | if (reg_map) | |
2425 | replace_regs (PATTERN (copy), reg_map, max_reg, 1); | |
2426 | mark_jump_label (PATTERN (copy), copy, 0); | |
2427 | if (REG_NOTES (insn)) | |
2428 | { | |
2429 | REG_NOTES (copy) = copy_rtx (REG_NOTES (insn)); | |
2430 | if (reg_map) | |
2431 | replace_regs (REG_NOTES (copy), reg_map, max_reg, 1); | |
2432 | } | |
2433 | ||
2434 | /* If this is a simple jump, add it to the jump chain. */ | |
2435 | ||
2436 | if (INSN_UID (copy) < max_jump_chain && JUMP_LABEL (copy) | |
2437 | && simplejump_p (copy)) | |
2438 | { | |
2439 | jump_chain[INSN_UID (copy)] | |
2440 | = jump_chain[INSN_UID (JUMP_LABEL (copy))]; | |
2441 | jump_chain[INSN_UID (JUMP_LABEL (copy))] = copy; | |
2442 | } | |
2443 | break; | |
2444 | ||
2445 | default: | |
2446 | abort (); | |
2447 | } | |
2448 | ||
2449 | /* Now clean up by emitting a jump to the end label and deleting the jump | |
2450 | at the start of the loop. */ | |
9c066566 | 2451 | if (! copy || GET_CODE (copy) != BARRIER) |
15a63be1 RK |
2452 | { |
2453 | copy = emit_jump_insn_before (gen_jump (get_label_after (insn)), | |
2454 | loop_start); | |
2455 | mark_jump_label (PATTERN (copy), copy, 0); | |
2456 | if (INSN_UID (copy) < max_jump_chain | |
2457 | && INSN_UID (JUMP_LABEL (copy)) < max_jump_chain) | |
2458 | { | |
2459 | jump_chain[INSN_UID (copy)] | |
2460 | = jump_chain[INSN_UID (JUMP_LABEL (copy))]; | |
2461 | jump_chain[INSN_UID (JUMP_LABEL (copy))] = copy; | |
2462 | } | |
2463 | emit_barrier_before (loop_start); | |
2464 | } | |
2465 | ||
15a63be1 RK |
2466 | /* Mark the exit code as the virtual top of the converted loop. */ |
2467 | emit_note_before (NOTE_INSN_LOOP_VTOP, exitcode); | |
2468 | ||
cd423ead RK |
2469 | delete_insn (next_nonnote_insn (loop_start)); |
2470 | ||
15a63be1 RK |
2471 | return 1; |
2472 | } | |
2473 | \f | |
2474 | /* Move all block-beg, block-end, loop-beg, loop-cont, loop-vtop, and | |
915f619f JW |
2475 | loop-end notes between START and END out before START. Assume that |
2476 | END is not such a note. START may be such a note. Returns the value | |
2477 | of the new starting insn, which may be different if the original start | |
2478 | was such a note. */ | |
15a63be1 | 2479 | |
915f619f | 2480 | rtx |
15a63be1 RK |
2481 | squeeze_notes (start, end) |
2482 | rtx start, end; | |
2483 | { | |
2484 | rtx insn; | |
2485 | rtx next; | |
2486 | ||
2487 | for (insn = start; insn != end; insn = next) | |
2488 | { | |
2489 | next = NEXT_INSN (insn); | |
2490 | if (GET_CODE (insn) == NOTE | |
2491 | && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END | |
2492 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG | |
2493 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG | |
2494 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END | |
2495 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_CONT | |
2496 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_VTOP)) | |
2497 | { | |
915f619f JW |
2498 | if (insn == start) |
2499 | start = next; | |
2500 | else | |
2501 | { | |
2502 | rtx prev = PREV_INSN (insn); | |
2503 | PREV_INSN (insn) = PREV_INSN (start); | |
2504 | NEXT_INSN (insn) = start; | |
2505 | NEXT_INSN (PREV_INSN (insn)) = insn; | |
2506 | PREV_INSN (NEXT_INSN (insn)) = insn; | |
2507 | NEXT_INSN (prev) = next; | |
2508 | PREV_INSN (next) = prev; | |
2509 | } | |
15a63be1 RK |
2510 | } |
2511 | } | |
915f619f JW |
2512 | |
2513 | return start; | |
15a63be1 RK |
2514 | } |
2515 | \f | |
2516 | /* Compare the instructions before insn E1 with those before E2 | |
2517 | to find an opportunity for cross jumping. | |
2518 | (This means detecting identical sequences of insns followed by | |
2519 | jumps to the same place, or followed by a label and a jump | |
2520 | to that label, and replacing one with a jump to the other.) | |
2521 | ||
2522 | Assume E1 is a jump that jumps to label E2 | |
2523 | (that is not always true but it might as well be). | |
2524 | Find the longest possible equivalent sequences | |
2525 | and store the first insns of those sequences into *F1 and *F2. | |
2526 | Store zero there if no equivalent preceding instructions are found. | |
2527 | ||
2528 | We give up if we find a label in stream 1. | |
2529 | Actually we could transfer that label into stream 2. */ | |
2530 | ||
2531 | static void | |
2532 | find_cross_jump (e1, e2, minimum, f1, f2) | |
2533 | rtx e1, e2; | |
2534 | int minimum; | |
2535 | rtx *f1, *f2; | |
2536 | { | |
2537 | register rtx i1 = e1, i2 = e2; | |
2538 | register rtx p1, p2; | |
2539 | int lose = 0; | |
2540 | ||
2541 | rtx last1 = 0, last2 = 0; | |
2542 | rtx afterlast1 = 0, afterlast2 = 0; | |
2543 | rtx prev1; | |
2544 | ||
2545 | *f1 = 0; | |
2546 | *f2 = 0; | |
2547 | ||
2548 | while (1) | |
2549 | { | |
2550 | i1 = prev_nonnote_insn (i1); | |
2551 | ||
2552 | i2 = PREV_INSN (i2); | |
2553 | while (i2 && (GET_CODE (i2) == NOTE || GET_CODE (i2) == CODE_LABEL)) | |
2554 | i2 = PREV_INSN (i2); | |
2555 | ||
2556 | if (i1 == 0) | |
2557 | break; | |
2558 | ||
2559 | /* Don't allow the range of insns preceding E1 or E2 | |
2560 | to include the other (E2 or E1). */ | |
2561 | if (i2 == e1 || i1 == e2) | |
2562 | break; | |
2563 | ||
2564 | /* If we will get to this code by jumping, those jumps will be | |
2565 | tensioned to go directly to the new label (before I2), | |
2566 | so this cross-jumping won't cost extra. So reduce the minimum. */ | |
2567 | if (GET_CODE (i1) == CODE_LABEL) | |
2568 | { | |
2569 | --minimum; | |
2570 | break; | |
2571 | } | |
2572 | ||
2573 | if (i2 == 0 || GET_CODE (i1) != GET_CODE (i2)) | |
2574 | break; | |
2575 | ||
2576 | p1 = PATTERN (i1); | |
2577 | p2 = PATTERN (i2); | |
2578 | ||
4d367579 DE |
2579 | /* If this is a CALL_INSN, compare register usage information. |
2580 | If we don't check this on stack register machines, the two | |
2581 | CALL_INSNs might be merged leaving reg-stack.c with mismatching | |
2582 | numbers of stack registers in the same basic block. | |
2583 | If we don't check this on machines with delay slots, a delay slot may | |
2584 | be filled that clobbers a parameter expected by the subroutine. | |
47b0bb94 | 2585 | |
4d367579 DE |
2586 | ??? We take the simple route for now and assume that if they're |
2587 | equal, they were constructed identically. */ | |
2588 | ||
2589 | if (GET_CODE (i1) == CALL_INSN | |
2590 | && ! rtx_equal_p (CALL_INSN_FUNCTION_USAGE (i1), | |
2591 | CALL_INSN_FUNCTION_USAGE (i2))) | |
2592 | lose = 1; | |
2593 | ||
2594 | #ifdef STACK_REGS | |
15a63be1 RK |
2595 | /* If cross_jump_death_matters is not 0, the insn's mode |
2596 | indicates whether or not the insn contains any stack-like | |
0f41302f | 2597 | regs. */ |
15a63be1 | 2598 | |
47b0bb94 | 2599 | if (!lose && cross_jump_death_matters && GET_MODE (i1) == QImode) |
15a63be1 RK |
2600 | { |
2601 | /* If register stack conversion has already been done, then | |
2602 | death notes must also be compared before it is certain that | |
0f41302f | 2603 | the two instruction streams match. */ |
15a63be1 RK |
2604 | |
2605 | rtx note; | |
2606 | HARD_REG_SET i1_regset, i2_regset; | |
2607 | ||
2608 | CLEAR_HARD_REG_SET (i1_regset); | |
2609 | CLEAR_HARD_REG_SET (i2_regset); | |
2610 | ||
2611 | for (note = REG_NOTES (i1); note; note = XEXP (note, 1)) | |
2612 | if (REG_NOTE_KIND (note) == REG_DEAD | |
2613 | && STACK_REG_P (XEXP (note, 0))) | |
2614 | SET_HARD_REG_BIT (i1_regset, REGNO (XEXP (note, 0))); | |
2615 | ||
2616 | for (note = REG_NOTES (i2); note; note = XEXP (note, 1)) | |
2617 | if (REG_NOTE_KIND (note) == REG_DEAD | |
2618 | && STACK_REG_P (XEXP (note, 0))) | |
2619 | SET_HARD_REG_BIT (i2_regset, REGNO (XEXP (note, 0))); | |
2620 | ||
2621 | GO_IF_HARD_REG_EQUAL (i1_regset, i2_regset, done); | |
2622 | ||
2623 | lose = 1; | |
2624 | ||
2625 | done: | |
2626 | ; | |
2627 | } | |
2628 | #endif | |
2629 | ||
44c389e4 JW |
2630 | /* Don't allow old-style asm or volatile extended asms to be accepted |
2631 | for cross jumping purposes. It is conceptually correct to allow | |
2632 | them, since cross-jumping preserves the dynamic instruction order | |
2633 | even though it is changing the static instruction order. However, | |
2634 | if an asm is being used to emit an assembler pseudo-op, such as | |
2635 | the MIPS `.set reorder' pseudo-op, then the static instruction order | |
2636 | matters and it must be preserved. */ | |
2637 | if (GET_CODE (p1) == ASM_INPUT || GET_CODE (p2) == ASM_INPUT | |
2638 | || (GET_CODE (p1) == ASM_OPERANDS && MEM_VOLATILE_P (p1)) | |
2639 | || (GET_CODE (p2) == ASM_OPERANDS && MEM_VOLATILE_P (p2))) | |
2640 | lose = 1; | |
2641 | ||
2642 | if (lose || GET_CODE (p1) != GET_CODE (p2) | |
15a63be1 RK |
2643 | || ! rtx_renumbered_equal_p (p1, p2)) |
2644 | { | |
2645 | /* The following code helps take care of G++ cleanups. */ | |
2646 | rtx equiv1; | |
2647 | rtx equiv2; | |
2648 | ||
2649 | if (!lose && GET_CODE (p1) == GET_CODE (p2) | |
5f4f0e22 CH |
2650 | && ((equiv1 = find_reg_note (i1, REG_EQUAL, NULL_RTX)) != 0 |
2651 | || (equiv1 = find_reg_note (i1, REG_EQUIV, NULL_RTX)) != 0) | |
2652 | && ((equiv2 = find_reg_note (i2, REG_EQUAL, NULL_RTX)) != 0 | |
2653 | || (equiv2 = find_reg_note (i2, REG_EQUIV, NULL_RTX)) != 0) | |
15a63be1 RK |
2654 | /* If the equivalences are not to a constant, they may |
2655 | reference pseudos that no longer exist, so we can't | |
2656 | use them. */ | |
2657 | && CONSTANT_P (XEXP (equiv1, 0)) | |
2658 | && rtx_equal_p (XEXP (equiv1, 0), XEXP (equiv2, 0))) | |
2659 | { | |
2660 | rtx s1 = single_set (i1); | |
2661 | rtx s2 = single_set (i2); | |
2662 | if (s1 != 0 && s2 != 0 | |
2663 | && rtx_renumbered_equal_p (SET_DEST (s1), SET_DEST (s2))) | |
2664 | { | |
2665 | validate_change (i1, &SET_SRC (s1), XEXP (equiv1, 0), 1); | |
2666 | validate_change (i2, &SET_SRC (s2), XEXP (equiv2, 0), 1); | |
2667 | if (! rtx_renumbered_equal_p (p1, p2)) | |
2668 | cancel_changes (0); | |
2669 | else if (apply_change_group ()) | |
2670 | goto win; | |
2671 | } | |
2672 | } | |
2673 | ||
2674 | /* Insns fail to match; cross jumping is limited to the following | |
2675 | insns. */ | |
2676 | ||
2677 | #ifdef HAVE_cc0 | |
2678 | /* Don't allow the insn after a compare to be shared by | |
2679 | cross-jumping unless the compare is also shared. | |
2680 | Here, if either of these non-matching insns is a compare, | |
2681 | exclude the following insn from possible cross-jumping. */ | |
2682 | if (sets_cc0_p (p1) || sets_cc0_p (p2)) | |
2683 | last1 = afterlast1, last2 = afterlast2, ++minimum; | |
2684 | #endif | |
2685 | ||
2686 | /* If cross-jumping here will feed a jump-around-jump | |
2687 | optimization, this jump won't cost extra, so reduce | |
2688 | the minimum. */ | |
2689 | if (GET_CODE (i1) == JUMP_INSN | |
2690 | && JUMP_LABEL (i1) | |
2691 | && prev_real_insn (JUMP_LABEL (i1)) == e1) | |
2692 | --minimum; | |
2693 | break; | |
2694 | } | |
2695 | ||
2696 | win: | |
2697 | if (GET_CODE (p1) != USE && GET_CODE (p1) != CLOBBER) | |
2698 | { | |
2699 | /* Ok, this insn is potentially includable in a cross-jump here. */ | |
2700 | afterlast1 = last1, afterlast2 = last2; | |
2701 | last1 = i1, last2 = i2, --minimum; | |
2702 | } | |
2703 | } | |
2704 | ||
15a63be1 RK |
2705 | if (minimum <= 0 && last1 != 0 && last1 != e1) |
2706 | *f1 = last1, *f2 = last2; | |
2707 | } | |
2708 | ||
2709 | static void | |
2710 | do_cross_jump (insn, newjpos, newlpos) | |
2711 | rtx insn, newjpos, newlpos; | |
2712 | { | |
2713 | /* Find an existing label at this point | |
2714 | or make a new one if there is none. */ | |
2715 | register rtx label = get_label_before (newlpos); | |
2716 | ||
2717 | /* Make the same jump insn jump to the new point. */ | |
2718 | if (GET_CODE (PATTERN (insn)) == RETURN) | |
2719 | { | |
2720 | /* Remove from jump chain of returns. */ | |
2721 | delete_from_jump_chain (insn); | |
2722 | /* Change the insn. */ | |
2723 | PATTERN (insn) = gen_jump (label); | |
2724 | INSN_CODE (insn) = -1; | |
2725 | JUMP_LABEL (insn) = label; | |
2726 | LABEL_NUSES (label)++; | |
2727 | /* Add to new the jump chain. */ | |
2728 | if (INSN_UID (label) < max_jump_chain | |
2729 | && INSN_UID (insn) < max_jump_chain) | |
2730 | { | |
2731 | jump_chain[INSN_UID (insn)] = jump_chain[INSN_UID (label)]; | |
2732 | jump_chain[INSN_UID (label)] = insn; | |
2733 | } | |
2734 | } | |
2735 | else | |
2736 | redirect_jump (insn, label); | |
2737 | ||
2738 | /* Delete the matching insns before the jump. Also, remove any REG_EQUAL | |
2739 | or REG_EQUIV note in the NEWLPOS stream that isn't also present in | |
2740 | the NEWJPOS stream. */ | |
2741 | ||
2742 | while (newjpos != insn) | |
2743 | { | |
2744 | rtx lnote; | |
2745 | ||
2746 | for (lnote = REG_NOTES (newlpos); lnote; lnote = XEXP (lnote, 1)) | |
2747 | if ((REG_NOTE_KIND (lnote) == REG_EQUAL | |
2748 | || REG_NOTE_KIND (lnote) == REG_EQUIV) | |
2749 | && ! find_reg_note (newjpos, REG_EQUAL, XEXP (lnote, 0)) | |
2750 | && ! find_reg_note (newjpos, REG_EQUIV, XEXP (lnote, 0))) | |
2751 | remove_note (newlpos, lnote); | |
2752 | ||
2753 | delete_insn (newjpos); | |
2754 | newjpos = next_real_insn (newjpos); | |
2755 | newlpos = next_real_insn (newlpos); | |
2756 | } | |
2757 | } | |
2758 | \f | |
2759 | /* Return the label before INSN, or put a new label there. */ | |
2760 | ||
2761 | rtx | |
2762 | get_label_before (insn) | |
2763 | rtx insn; | |
2764 | { | |
2765 | rtx label; | |
2766 | ||
2767 | /* Find an existing label at this point | |
2768 | or make a new one if there is none. */ | |
2769 | label = prev_nonnote_insn (insn); | |
2770 | ||
2771 | if (label == 0 || GET_CODE (label) != CODE_LABEL) | |
2772 | { | |
2773 | rtx prev = PREV_INSN (insn); | |
2774 | ||
15a63be1 RK |
2775 | label = gen_label_rtx (); |
2776 | emit_label_after (label, prev); | |
2777 | LABEL_NUSES (label) = 0; | |
2778 | } | |
2779 | return label; | |
2780 | } | |
2781 | ||
2782 | /* Return the label after INSN, or put a new label there. */ | |
2783 | ||
2784 | rtx | |
2785 | get_label_after (insn) | |
2786 | rtx insn; | |
2787 | { | |
2788 | rtx label; | |
2789 | ||
2790 | /* Find an existing label at this point | |
2791 | or make a new one if there is none. */ | |
2792 | label = next_nonnote_insn (insn); | |
2793 | ||
2794 | if (label == 0 || GET_CODE (label) != CODE_LABEL) | |
2795 | { | |
15a63be1 RK |
2796 | label = gen_label_rtx (); |
2797 | emit_label_after (label, insn); | |
2798 | LABEL_NUSES (label) = 0; | |
2799 | } | |
2800 | return label; | |
2801 | } | |
2802 | \f | |
2803 | /* Return 1 if INSN is a jump that jumps to right after TARGET | |
2804 | only on the condition that TARGET itself would drop through. | |
2805 | Assumes that TARGET is a conditional jump. */ | |
2806 | ||
2807 | static int | |
2808 | jump_back_p (insn, target) | |
2809 | rtx insn, target; | |
2810 | { | |
2811 | rtx cinsn, ctarget; | |
2812 | enum rtx_code codei, codet; | |
2813 | ||
2814 | if (simplejump_p (insn) || ! condjump_p (insn) | |
2815 | || simplejump_p (target) | |
2816 | || target != prev_real_insn (JUMP_LABEL (insn))) | |
2817 | return 0; | |
2818 | ||
2819 | cinsn = XEXP (SET_SRC (PATTERN (insn)), 0); | |
2820 | ctarget = XEXP (SET_SRC (PATTERN (target)), 0); | |
2821 | ||
2822 | codei = GET_CODE (cinsn); | |
2823 | codet = GET_CODE (ctarget); | |
2824 | ||
2825 | if (XEXP (SET_SRC (PATTERN (insn)), 1) == pc_rtx) | |
2826 | { | |
2827 | if (! can_reverse_comparison_p (cinsn, insn)) | |
2828 | return 0; | |
2829 | codei = reverse_condition (codei); | |
2830 | } | |
2831 | ||
2832 | if (XEXP (SET_SRC (PATTERN (target)), 2) == pc_rtx) | |
2833 | { | |
2834 | if (! can_reverse_comparison_p (ctarget, target)) | |
2835 | return 0; | |
2836 | codet = reverse_condition (codet); | |
2837 | } | |
2838 | ||
2839 | return (codei == codet | |
2840 | && rtx_renumbered_equal_p (XEXP (cinsn, 0), XEXP (ctarget, 0)) | |
2841 | && rtx_renumbered_equal_p (XEXP (cinsn, 1), XEXP (ctarget, 1))); | |
2842 | } | |
2843 | \f | |
2844 | /* Given a comparison, COMPARISON, inside a conditional jump insn, INSN, | |
2845 | return non-zero if it is safe to reverse this comparison. It is if our | |
2846 | floating-point is not IEEE, if this is an NE or EQ comparison, or if | |
2847 | this is known to be an integer comparison. */ | |
2848 | ||
2849 | int | |
2850 | can_reverse_comparison_p (comparison, insn) | |
2851 | rtx comparison; | |
2852 | rtx insn; | |
2853 | { | |
2854 | rtx arg0; | |
2855 | ||
2856 | /* If this is not actually a comparison, we can't reverse it. */ | |
2857 | if (GET_RTX_CLASS (GET_CODE (comparison)) != '<') | |
2858 | return 0; | |
2859 | ||
2860 | if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT | |
2861 | /* If this is an NE comparison, it is safe to reverse it to an EQ | |
2862 | comparison and vice versa, even for floating point. If no operands | |
2863 | are NaNs, the reversal is valid. If some operand is a NaN, EQ is | |
2864 | always false and NE is always true, so the reversal is also valid. */ | |
9b2e59ad | 2865 | || flag_fast_math |
15a63be1 RK |
2866 | || GET_CODE (comparison) == NE |
2867 | || GET_CODE (comparison) == EQ) | |
2868 | return 1; | |
2869 | ||
2870 | arg0 = XEXP (comparison, 0); | |
2871 | ||
2872 | /* Make sure ARG0 is one of the actual objects being compared. If we | |
2873 | can't do this, we can't be sure the comparison can be reversed. | |
2874 | ||
2875 | Handle cc0 and a MODE_CC register. */ | |
2876 | if ((GET_CODE (arg0) == REG && GET_MODE_CLASS (GET_MODE (arg0)) == MODE_CC) | |
2877 | #ifdef HAVE_cc0 | |
2878 | || arg0 == cc0_rtx | |
2879 | #endif | |
2880 | ) | |
2881 | { | |
2882 | rtx prev = prev_nonnote_insn (insn); | |
2883 | rtx set = single_set (prev); | |
2884 | ||
2885 | if (set == 0 || SET_DEST (set) != arg0) | |
2886 | return 0; | |
2887 | ||
2888 | arg0 = SET_SRC (set); | |
2889 | ||
2890 | if (GET_CODE (arg0) == COMPARE) | |
2891 | arg0 = XEXP (arg0, 0); | |
2892 | } | |
2893 | ||
2894 | /* We can reverse this if ARG0 is a CONST_INT or if its mode is | |
2895 | not VOIDmode and neither a MODE_CC nor MODE_FLOAT type. */ | |
2896 | return (GET_CODE (arg0) == CONST_INT | |
2897 | || (GET_MODE (arg0) != VOIDmode | |
2898 | && GET_MODE_CLASS (GET_MODE (arg0)) != MODE_CC | |
2899 | && GET_MODE_CLASS (GET_MODE (arg0)) != MODE_FLOAT)); | |
2900 | } | |
2901 | ||
2902 | /* Given an rtx-code for a comparison, return the code | |
2903 | for the negated comparison. | |
2904 | WATCH OUT! reverse_condition is not safe to use on a jump | |
2905 | that might be acting on the results of an IEEE floating point comparison, | |
2906 | because of the special treatment of non-signaling nans in comparisons. | |
2907 | Use can_reverse_comparison_p to be sure. */ | |
2908 | ||
2909 | enum rtx_code | |
2910 | reverse_condition (code) | |
2911 | enum rtx_code code; | |
2912 | { | |
2913 | switch (code) | |
2914 | { | |
2915 | case EQ: | |
2916 | return NE; | |
2917 | ||
2918 | case NE: | |
2919 | return EQ; | |
2920 | ||
2921 | case GT: | |
2922 | return LE; | |
2923 | ||
2924 | case GE: | |
2925 | return LT; | |
2926 | ||
2927 | case LT: | |
2928 | return GE; | |
2929 | ||
2930 | case LE: | |
2931 | return GT; | |
2932 | ||
2933 | case GTU: | |
2934 | return LEU; | |
2935 | ||
2936 | case GEU: | |
2937 | return LTU; | |
2938 | ||
2939 | case LTU: | |
2940 | return GEU; | |
2941 | ||
2942 | case LEU: | |
2943 | return GTU; | |
2944 | ||
2945 | default: | |
2946 | abort (); | |
2947 | return UNKNOWN; | |
2948 | } | |
2949 | } | |
2950 | ||
2951 | /* Similar, but return the code when two operands of a comparison are swapped. | |
2952 | This IS safe for IEEE floating-point. */ | |
2953 | ||
2954 | enum rtx_code | |
2955 | swap_condition (code) | |
2956 | enum rtx_code code; | |
2957 | { | |
2958 | switch (code) | |
2959 | { | |
2960 | case EQ: | |
2961 | case NE: | |
2962 | return code; | |
2963 | ||
2964 | case GT: | |
2965 | return LT; | |
2966 | ||
2967 | case GE: | |
2968 | return LE; | |
2969 | ||
2970 | case LT: | |
2971 | return GT; | |
2972 | ||
2973 | case LE: | |
2974 | return GE; | |
2975 | ||
2976 | case GTU: | |
2977 | return LTU; | |
2978 | ||
2979 | case GEU: | |
2980 | return LEU; | |
2981 | ||
2982 | case LTU: | |
2983 | return GTU; | |
2984 | ||
2985 | case LEU: | |
2986 | return GEU; | |
2987 | ||
2988 | default: | |
2989 | abort (); | |
2990 | return UNKNOWN; | |
2991 | } | |
2992 | } | |
2993 | ||
2994 | /* Given a comparison CODE, return the corresponding unsigned comparison. | |
2995 | If CODE is an equality comparison or already an unsigned comparison, | |
2996 | CODE is returned. */ | |
2997 | ||
2998 | enum rtx_code | |
2999 | unsigned_condition (code) | |
3000 | enum rtx_code code; | |
3001 | { | |
3002 | switch (code) | |
3003 | { | |
3004 | case EQ: | |
3005 | case NE: | |
3006 | case GTU: | |
3007 | case GEU: | |
3008 | case LTU: | |
3009 | case LEU: | |
3010 | return code; | |
3011 | ||
3012 | case GT: | |
3013 | return GTU; | |
3014 | ||
3015 | case GE: | |
3016 | return GEU; | |
3017 | ||
3018 | case LT: | |
3019 | return LTU; | |
3020 | ||
3021 | case LE: | |
3022 | return LEU; | |
3023 | ||
3024 | default: | |
3025 | abort (); | |
3026 | } | |
3027 | } | |
3028 | ||
3029 | /* Similarly, return the signed version of a comparison. */ | |
3030 | ||
3031 | enum rtx_code | |
3032 | signed_condition (code) | |
3033 | enum rtx_code code; | |
3034 | { | |
3035 | switch (code) | |
3036 | { | |
3037 | case EQ: | |
3038 | case NE: | |
3039 | case GT: | |
3040 | case GE: | |
3041 | case LT: | |
3042 | case LE: | |
3043 | return code; | |
3044 | ||
3045 | case GTU: | |
3046 | return GT; | |
3047 | ||
3048 | case GEU: | |
3049 | return GE; | |
3050 | ||
3051 | case LTU: | |
3052 | return LT; | |
3053 | ||
3054 | case LEU: | |
3055 | return LE; | |
3056 | ||
3057 | default: | |
3058 | abort (); | |
3059 | } | |
3060 | } | |
3061 | \f | |
3062 | /* Return non-zero if CODE1 is more strict than CODE2, i.e., if the | |
3063 | truth of CODE1 implies the truth of CODE2. */ | |
3064 | ||
3065 | int | |
3066 | comparison_dominates_p (code1, code2) | |
3067 | enum rtx_code code1, code2; | |
3068 | { | |
3069 | if (code1 == code2) | |
3070 | return 1; | |
3071 | ||
3072 | switch (code1) | |
3073 | { | |
3074 | case EQ: | |
3075 | if (code2 == LE || code2 == LEU || code2 == GE || code2 == GEU) | |
3076 | return 1; | |
3077 | break; | |
3078 | ||
3079 | case LT: | |
b0c38416 | 3080 | if (code2 == LE || code2 == NE) |
15a63be1 RK |
3081 | return 1; |
3082 | break; | |
3083 | ||
3084 | case GT: | |
b0c38416 | 3085 | if (code2 == GE || code2 == NE) |
15a63be1 RK |
3086 | return 1; |
3087 | break; | |
3088 | ||
3089 | case LTU: | |
b0c38416 | 3090 | if (code2 == LEU || code2 == NE) |
15a63be1 RK |
3091 | return 1; |
3092 | break; | |
3093 | ||
3094 | case GTU: | |
b0c38416 | 3095 | if (code2 == GEU || code2 == NE) |
15a63be1 RK |
3096 | return 1; |
3097 | break; | |
e9a25f70 JL |
3098 | |
3099 | default: | |
3100 | break; | |
15a63be1 RK |
3101 | } |
3102 | ||
3103 | return 0; | |
3104 | } | |
3105 | \f | |
3106 | /* Return 1 if INSN is an unconditional jump and nothing else. */ | |
3107 | ||
3108 | int | |
3109 | simplejump_p (insn) | |
3110 | rtx insn; | |
3111 | { | |
3112 | return (GET_CODE (insn) == JUMP_INSN | |
3113 | && GET_CODE (PATTERN (insn)) == SET | |
3114 | && GET_CODE (SET_DEST (PATTERN (insn))) == PC | |
3115 | && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF); | |
3116 | } | |
3117 | ||
3118 | /* Return nonzero if INSN is a (possibly) conditional jump | |
3119 | and nothing more. */ | |
3120 | ||
3121 | int | |
3122 | condjump_p (insn) | |
3123 | rtx insn; | |
3124 | { | |
3125 | register rtx x = PATTERN (insn); | |
3480bb98 JL |
3126 | if (GET_CODE (x) != SET) |
3127 | return 0; | |
3128 | if (GET_CODE (SET_DEST (x)) != PC) | |
3129 | return 0; | |
3130 | if (GET_CODE (SET_SRC (x)) == LABEL_REF) | |
3131 | return 1; | |
3132 | if (GET_CODE (SET_SRC (x)) != IF_THEN_ELSE) | |
3133 | return 0; | |
3134 | if (XEXP (SET_SRC (x), 2) == pc_rtx | |
3135 | && (GET_CODE (XEXP (SET_SRC (x), 1)) == LABEL_REF | |
3136 | || GET_CODE (XEXP (SET_SRC (x), 1)) == RETURN)) | |
3137 | return 1; | |
3138 | if (XEXP (SET_SRC (x), 1) == pc_rtx | |
3139 | && (GET_CODE (XEXP (SET_SRC (x), 2)) == LABEL_REF | |
3140 | || GET_CODE (XEXP (SET_SRC (x), 2)) == RETURN)) | |
3141 | return 1; | |
3142 | return 0; | |
3143 | } | |
3144 | ||
3145 | /* Return nonzero if INSN is a (possibly) conditional jump | |
3146 | and nothing more. */ | |
3147 | ||
3148 | int | |
3149 | condjump_in_parallel_p (insn) | |
3150 | rtx insn; | |
3151 | { | |
3152 | register rtx x = PATTERN (insn); | |
3153 | ||
3154 | if (GET_CODE (x) != PARALLEL) | |
3155 | return 0; | |
3156 | else | |
3157 | x = XVECEXP (x, 0, 0); | |
3158 | ||
15a63be1 RK |
3159 | if (GET_CODE (x) != SET) |
3160 | return 0; | |
3161 | if (GET_CODE (SET_DEST (x)) != PC) | |
3162 | return 0; | |
3163 | if (GET_CODE (SET_SRC (x)) == LABEL_REF) | |
3164 | return 1; | |
3165 | if (GET_CODE (SET_SRC (x)) != IF_THEN_ELSE) | |
3166 | return 0; | |
3167 | if (XEXP (SET_SRC (x), 2) == pc_rtx | |
3168 | && (GET_CODE (XEXP (SET_SRC (x), 1)) == LABEL_REF | |
3169 | || GET_CODE (XEXP (SET_SRC (x), 1)) == RETURN)) | |
3170 | return 1; | |
3171 | if (XEXP (SET_SRC (x), 1) == pc_rtx | |
3172 | && (GET_CODE (XEXP (SET_SRC (x), 2)) == LABEL_REF | |
3173 | || GET_CODE (XEXP (SET_SRC (x), 2)) == RETURN)) | |
3174 | return 1; | |
3175 | return 0; | |
3176 | } | |
3177 | ||
3178 | /* Return 1 if X is an RTX that does nothing but set the condition codes | |
3179 | and CLOBBER or USE registers. | |
3180 | Return -1 if X does explicitly set the condition codes, | |
3181 | but also does other things. */ | |
3182 | ||
3183 | int | |
3184 | sets_cc0_p (x) | |
3185 | rtx x; | |
3186 | { | |
3187 | #ifdef HAVE_cc0 | |
3188 | if (GET_CODE (x) == SET && SET_DEST (x) == cc0_rtx) | |
3189 | return 1; | |
3190 | if (GET_CODE (x) == PARALLEL) | |
3191 | { | |
3192 | int i; | |
3193 | int sets_cc0 = 0; | |
3194 | int other_things = 0; | |
3195 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
3196 | { | |
3197 | if (GET_CODE (XVECEXP (x, 0, i)) == SET | |
3198 | && SET_DEST (XVECEXP (x, 0, i)) == cc0_rtx) | |
3199 | sets_cc0 = 1; | |
3200 | else if (GET_CODE (XVECEXP (x, 0, i)) == SET) | |
3201 | other_things = 1; | |
3202 | } | |
3203 | return ! sets_cc0 ? 0 : other_things ? -1 : 1; | |
3204 | } | |
3205 | return 0; | |
3206 | #else | |
3207 | abort (); | |
3208 | #endif | |
3209 | } | |
3210 | \f | |
3211 | /* Follow any unconditional jump at LABEL; | |
3212 | return the ultimate label reached by any such chain of jumps. | |
3213 | If LABEL is not followed by a jump, return LABEL. | |
2d20b9df RS |
3214 | If the chain loops or we can't find end, return LABEL, |
3215 | since that tells caller to avoid changing the insn. | |
15a63be1 RK |
3216 | |
3217 | If RELOAD_COMPLETED is 0, we do not chain across a NOTE_INSN_LOOP_BEG or | |
3218 | a USE or CLOBBER. */ | |
3219 | ||
3220 | rtx | |
3221 | follow_jumps (label) | |
3222 | rtx label; | |
3223 | { | |
3224 | register rtx insn; | |
3225 | register rtx next; | |
3226 | register rtx value = label; | |
3227 | register int depth; | |
3228 | ||
3229 | for (depth = 0; | |
3230 | (depth < 10 | |
3231 | && (insn = next_active_insn (value)) != 0 | |
3232 | && GET_CODE (insn) == JUMP_INSN | |
a9cc9061 JL |
3233 | && ((JUMP_LABEL (insn) != 0 && simplejump_p (insn)) |
3234 | || GET_CODE (PATTERN (insn)) == RETURN) | |
15a63be1 RK |
3235 | && (next = NEXT_INSN (insn)) |
3236 | && GET_CODE (next) == BARRIER); | |
3237 | depth++) | |
3238 | { | |
3239 | /* Don't chain through the insn that jumps into a loop | |
3240 | from outside the loop, | |
3241 | since that would create multiple loop entry jumps | |
3242 | and prevent loop optimization. */ | |
3243 | rtx tem; | |
3244 | if (!reload_completed) | |
3245 | for (tem = value; tem != insn; tem = NEXT_INSN (tem)) | |
3246 | if (GET_CODE (tem) == NOTE | |
f6a6a1b3 DE |
3247 | && (NOTE_LINE_NUMBER (tem) == NOTE_INSN_LOOP_BEG |
3248 | /* ??? Optional. Disables some optimizations, but makes | |
3249 | gcov output more accurate with -O. */ | |
3250 | || (flag_test_coverage && NOTE_LINE_NUMBER (tem) > 0))) | |
15a63be1 RK |
3251 | return value; |
3252 | ||
3253 | /* If we have found a cycle, make the insn jump to itself. */ | |
3254 | if (JUMP_LABEL (insn) == label) | |
2d20b9df | 3255 | return label; |
b209b3c5 JVA |
3256 | |
3257 | tem = next_active_insn (JUMP_LABEL (insn)); | |
3258 | if (tem && (GET_CODE (PATTERN (tem)) == ADDR_VEC | |
3259 | || GET_CODE (PATTERN (tem)) == ADDR_DIFF_VEC)) | |
3260 | break; | |
3261 | ||
15a63be1 RK |
3262 | value = JUMP_LABEL (insn); |
3263 | } | |
2d20b9df RS |
3264 | if (depth == 10) |
3265 | return label; | |
15a63be1 RK |
3266 | return value; |
3267 | } | |
3268 | ||
3269 | /* Assuming that field IDX of X is a vector of label_refs, | |
3270 | replace each of them by the ultimate label reached by it. | |
3271 | Return nonzero if a change is made. | |
3272 | If IGNORE_LOOPS is 0, we do not chain across a NOTE_INSN_LOOP_BEG. */ | |
3273 | ||
3274 | static int | |
3275 | tension_vector_labels (x, idx) | |
3276 | register rtx x; | |
3277 | register int idx; | |
3278 | { | |
3279 | int changed = 0; | |
3280 | register int i; | |
3281 | for (i = XVECLEN (x, idx) - 1; i >= 0; i--) | |
3282 | { | |
3283 | register rtx olabel = XEXP (XVECEXP (x, idx, i), 0); | |
3284 | register rtx nlabel = follow_jumps (olabel); | |
3285 | if (nlabel && nlabel != olabel) | |
3286 | { | |
3287 | XEXP (XVECEXP (x, idx, i), 0) = nlabel; | |
3288 | ++LABEL_NUSES (nlabel); | |
3289 | if (--LABEL_NUSES (olabel) == 0) | |
3290 | delete_insn (olabel); | |
3291 | changed = 1; | |
3292 | } | |
3293 | } | |
3294 | return changed; | |
3295 | } | |
3296 | \f | |
3297 | /* Find all CODE_LABELs referred to in X, and increment their use counts. | |
3298 | If INSN is a JUMP_INSN and there is at least one CODE_LABEL referenced | |
3299 | in INSN, then store one of them in JUMP_LABEL (INSN). | |
3300 | If INSN is an INSN or a CALL_INSN and there is at least one CODE_LABEL | |
3301 | referenced in INSN, add a REG_LABEL note containing that label to INSN. | |
3302 | Also, when there are consecutive labels, canonicalize on the last of them. | |
3303 | ||
3304 | Note that two labels separated by a loop-beginning note | |
3305 | must be kept distinct if we have not yet done loop-optimization, | |
3306 | because the gap between them is where loop-optimize | |
3307 | will want to move invariant code to. CROSS_JUMP tells us | |
3308 | that loop-optimization is done with. | |
3309 | ||
3310 | Once reload has completed (CROSS_JUMP non-zero), we need not consider | |
3311 | two labels distinct if they are separated by only USE or CLOBBER insns. */ | |
3312 | ||
3313 | static void | |
3314 | mark_jump_label (x, insn, cross_jump) | |
3315 | register rtx x; | |
3316 | rtx insn; | |
3317 | int cross_jump; | |
3318 | { | |
3319 | register RTX_CODE code = GET_CODE (x); | |
3320 | register int i; | |
3321 | register char *fmt; | |
3322 | ||
3323 | switch (code) | |
3324 | { | |
3325 | case PC: | |
3326 | case CC0: | |
3327 | case REG: | |
3328 | case SUBREG: | |
3329 | case CONST_INT: | |
3330 | case SYMBOL_REF: | |
3331 | case CONST_DOUBLE: | |
3332 | case CLOBBER: | |
3333 | case CALL: | |
3334 | return; | |
3335 | ||
d7ea4cf6 RK |
3336 | case MEM: |
3337 | /* If this is a constant-pool reference, see if it is a label. */ | |
3338 | if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF | |
3339 | && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0))) | |
3340 | mark_jump_label (get_pool_constant (XEXP (x, 0)), insn, cross_jump); | |
3341 | break; | |
3342 | ||
15a63be1 RK |
3343 | case LABEL_REF: |
3344 | { | |
5c5e36c5 RK |
3345 | rtx label = XEXP (x, 0); |
3346 | rtx olabel = label; | |
3347 | rtx note; | |
3348 | rtx next; | |
3349 | ||
15a63be1 RK |
3350 | if (GET_CODE (label) != CODE_LABEL) |
3351 | abort (); | |
5c5e36c5 | 3352 | |
705f26cf RS |
3353 | /* Ignore references to labels of containing functions. */ |
3354 | if (LABEL_REF_NONLOCAL_P (x)) | |
3355 | break; | |
5c5e36c5 | 3356 | |
15a63be1 RK |
3357 | /* If there are other labels following this one, |
3358 | replace it with the last of the consecutive labels. */ | |
3359 | for (next = NEXT_INSN (label); next; next = NEXT_INSN (next)) | |
3360 | { | |
3361 | if (GET_CODE (next) == CODE_LABEL) | |
3362 | label = next; | |
3363 | else if (cross_jump && GET_CODE (next) == INSN | |
3364 | && (GET_CODE (PATTERN (next)) == USE | |
3365 | || GET_CODE (PATTERN (next)) == CLOBBER)) | |
3366 | continue; | |
3367 | else if (GET_CODE (next) != NOTE) | |
3368 | break; | |
3369 | else if (! cross_jump | |
3370 | && (NOTE_LINE_NUMBER (next) == NOTE_INSN_LOOP_BEG | |
f6a6a1b3 DE |
3371 | || NOTE_LINE_NUMBER (next) == NOTE_INSN_FUNCTION_END |
3372 | /* ??? Optional. Disables some optimizations, but | |
3373 | makes gcov output more accurate with -O. */ | |
3374 | || (flag_test_coverage && NOTE_LINE_NUMBER (next) > 0))) | |
15a63be1 RK |
3375 | break; |
3376 | } | |
5c5e36c5 | 3377 | |
15a63be1 RK |
3378 | XEXP (x, 0) = label; |
3379 | ++LABEL_NUSES (label); | |
5c5e36c5 | 3380 | |
15a63be1 RK |
3381 | if (insn) |
3382 | { | |
3383 | if (GET_CODE (insn) == JUMP_INSN) | |
3384 | JUMP_LABEL (insn) = label; | |
5c5e36c5 RK |
3385 | |
3386 | /* If we've changed OLABEL and we had a REG_LABEL note | |
3387 | for it, update it as well. */ | |
3388 | else if (label != olabel | |
3389 | && (note = find_reg_note (insn, REG_LABEL, olabel)) != 0) | |
3390 | XEXP (note, 0) = label; | |
3391 | ||
3392 | /* Otherwise, add a REG_LABEL note for LABEL unless there already | |
3393 | is one. */ | |
0e690bdb | 3394 | else if (! find_reg_note (insn, REG_LABEL, label)) |
15a63be1 RK |
3395 | { |
3396 | rtx next = next_real_insn (label); | |
3397 | /* Don't record labels that refer to dispatch tables. | |
3398 | This is not necessary, since the tablejump | |
3399 | references the same label. | |
3400 | And if we did record them, flow.c would make worse code. */ | |
3401 | if (next == 0 | |
3402 | || ! (GET_CODE (next) == JUMP_INSN | |
3403 | && (GET_CODE (PATTERN (next)) == ADDR_VEC | |
3404 | || GET_CODE (PATTERN (next)) == ADDR_DIFF_VEC))) | |
8cd2aff2 RK |
3405 | REG_NOTES (insn) = gen_rtx (EXPR_LIST, REG_LABEL, label, |
3406 | REG_NOTES (insn)); | |
15a63be1 RK |
3407 | } |
3408 | } | |
3409 | return; | |
3410 | } | |
3411 | ||
3412 | /* Do walk the labels in a vector, but not the first operand of an | |
3413 | ADDR_DIFF_VEC. Don't set the JUMP_LABEL of a vector. */ | |
3414 | case ADDR_VEC: | |
3415 | case ADDR_DIFF_VEC: | |
3416 | { | |
3417 | int eltnum = code == ADDR_DIFF_VEC ? 1 : 0; | |
3418 | ||
3419 | for (i = 0; i < XVECLEN (x, eltnum); i++) | |
5f4f0e22 | 3420 | mark_jump_label (XVECEXP (x, eltnum, i), NULL_RTX, cross_jump); |
15a63be1 | 3421 | } |
e9a25f70 JL |
3422 | return; |
3423 | ||
3424 | default: | |
3425 | break; | |
15a63be1 RK |
3426 | } |
3427 | ||
3428 | fmt = GET_RTX_FORMAT (code); | |
3429 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
3430 | { | |
3431 | if (fmt[i] == 'e') | |
3432 | mark_jump_label (XEXP (x, i), insn, cross_jump); | |
3433 | else if (fmt[i] == 'E') | |
3434 | { | |
3435 | register int j; | |
3436 | for (j = 0; j < XVECLEN (x, i); j++) | |
3437 | mark_jump_label (XVECEXP (x, i, j), insn, cross_jump); | |
3438 | } | |
3439 | } | |
3440 | } | |
3441 | ||
3442 | /* If all INSN does is set the pc, delete it, | |
3443 | and delete the insn that set the condition codes for it | |
3444 | if that's what the previous thing was. */ | |
3445 | ||
3446 | void | |
3447 | delete_jump (insn) | |
3448 | rtx insn; | |
3449 | { | |
3e5478ea RK |
3450 | register rtx set = single_set (insn); |
3451 | ||
3452 | if (set && GET_CODE (SET_DEST (set)) == PC) | |
3453 | delete_computation (insn); | |
3454 | } | |
3455 | ||
3456 | /* Delete INSN and recursively delete insns that compute values used only | |
3457 | by INSN. This uses the REG_DEAD notes computed during flow analysis. | |
3458 | If we are running before flow.c, we need do nothing since flow.c will | |
3459 | delete dead code. We also can't know if the registers being used are | |
3460 | dead or not at this point. | |
3461 | ||
3462 | Otherwise, look at all our REG_DEAD notes. If a previous insn does | |
3463 | nothing other than set a register that dies in this insn, we can delete | |
3464 | that insn as well. | |
3465 | ||
3466 | On machines with CC0, if CC0 is used in this insn, we may be able to | |
3467 | delete the insn that set it. */ | |
3468 | ||
8cd2aff2 | 3469 | static void |
3e5478ea RK |
3470 | delete_computation (insn) |
3471 | rtx insn; | |
3472 | { | |
3473 | rtx note, next; | |
15a63be1 | 3474 | |
15a63be1 | 3475 | #ifdef HAVE_cc0 |
2fb95912 | 3476 | if (reg_referenced_p (cc0_rtx, PATTERN (insn))) |
3e5478ea | 3477 | { |
77472c5a | 3478 | rtx prev = prev_nonnote_insn (insn); |
15a63be1 RK |
3479 | /* We assume that at this stage |
3480 | CC's are always set explicitly | |
3481 | and always immediately before the jump that | |
3482 | will use them. So if the previous insn | |
3483 | exists to set the CC's, delete it | |
3484 | (unless it performs auto-increments, etc.). */ | |
3485 | if (prev && GET_CODE (prev) == INSN | |
3486 | && sets_cc0_p (PATTERN (prev))) | |
3487 | { | |
3488 | if (sets_cc0_p (PATTERN (prev)) > 0 | |
5f4f0e22 | 3489 | && !FIND_REG_INC_NOTE (prev, NULL_RTX)) |
3e5478ea | 3490 | delete_computation (prev); |
15a63be1 RK |
3491 | else |
3492 | /* Otherwise, show that cc0 won't be used. */ | |
3493 | REG_NOTES (prev) = gen_rtx (EXPR_LIST, REG_UNUSED, | |
3494 | cc0_rtx, REG_NOTES (prev)); | |
3495 | } | |
77472c5a | 3496 | } |
3e5478ea | 3497 | #endif |
15a63be1 | 3498 | |
77472c5a TW |
3499 | for (note = REG_NOTES (insn); note; note = next) |
3500 | { | |
3501 | rtx our_prev; | |
15a63be1 | 3502 | |
77472c5a | 3503 | next = XEXP (note, 1); |
15a63be1 | 3504 | |
77472c5a TW |
3505 | if (REG_NOTE_KIND (note) != REG_DEAD |
3506 | /* Verify that the REG_NOTE is legitimate. */ | |
3507 | || GET_CODE (XEXP (note, 0)) != REG) | |
3508 | continue; | |
15a63be1 | 3509 | |
77472c5a TW |
3510 | for (our_prev = prev_nonnote_insn (insn); |
3511 | our_prev && GET_CODE (our_prev) == INSN; | |
3512 | our_prev = prev_nonnote_insn (our_prev)) | |
3513 | { | |
3514 | /* If we reach a SEQUENCE, it is too complex to try to | |
3515 | do anything with it, so give up. */ | |
3516 | if (GET_CODE (PATTERN (our_prev)) == SEQUENCE) | |
3517 | break; | |
15a63be1 | 3518 | |
77472c5a TW |
3519 | if (GET_CODE (PATTERN (our_prev)) == USE |
3520 | && GET_CODE (XEXP (PATTERN (our_prev), 0)) == INSN) | |
3521 | /* reorg creates USEs that look like this. We leave them | |
3522 | alone because reorg needs them for its own purposes. */ | |
3523 | break; | |
15a63be1 | 3524 | |
77472c5a TW |
3525 | if (reg_set_p (XEXP (note, 0), PATTERN (our_prev))) |
3526 | { | |
3527 | if (FIND_REG_INC_NOTE (our_prev, NULL_RTX)) | |
3528 | break; | |
15a63be1 | 3529 | |
77472c5a TW |
3530 | if (GET_CODE (PATTERN (our_prev)) == PARALLEL) |
3531 | { | |
3532 | /* If we find a SET of something else, we can't | |
3533 | delete the insn. */ | |
15a63be1 | 3534 | |
77472c5a | 3535 | int i; |
15a63be1 | 3536 | |
77472c5a TW |
3537 | for (i = 0; i < XVECLEN (PATTERN (our_prev), 0); i++) |
3538 | { | |
3539 | rtx part = XVECEXP (PATTERN (our_prev), 0, i); | |
15a63be1 | 3540 | |
77472c5a TW |
3541 | if (GET_CODE (part) == SET |
3542 | && SET_DEST (part) != XEXP (note, 0)) | |
3543 | break; | |
3544 | } | |
15a63be1 | 3545 | |
77472c5a TW |
3546 | if (i == XVECLEN (PATTERN (our_prev), 0)) |
3547 | delete_computation (our_prev); | |
3548 | } | |
3549 | else if (GET_CODE (PATTERN (our_prev)) == SET | |
3550 | && SET_DEST (PATTERN (our_prev)) == XEXP (note, 0)) | |
3551 | delete_computation (our_prev); | |
3552 | ||
3553 | break; | |
3554 | } | |
3555 | ||
3556 | /* If OUR_PREV references the register that dies here, it is an | |
3557 | additional use. Hence any prior SET isn't dead. However, this | |
3558 | insn becomes the new place for the REG_DEAD note. */ | |
3559 | if (reg_overlap_mentioned_p (XEXP (note, 0), | |
3560 | PATTERN (our_prev))) | |
3561 | { | |
3562 | XEXP (note, 1) = REG_NOTES (our_prev); | |
3563 | REG_NOTES (our_prev) = note; | |
3564 | break; | |
3565 | } | |
3566 | } | |
15a63be1 | 3567 | } |
3e5478ea | 3568 | |
77472c5a | 3569 | delete_insn (insn); |
15a63be1 RK |
3570 | } |
3571 | \f | |
3572 | /* Delete insn INSN from the chain of insns and update label ref counts. | |
3573 | May delete some following insns as a consequence; may even delete | |
3574 | a label elsewhere and insns that follow it. | |
3575 | ||
3576 | Returns the first insn after INSN that was not deleted. */ | |
3577 | ||
3578 | rtx | |
3579 | delete_insn (insn) | |
3580 | register rtx insn; | |
3581 | { | |
3582 | register rtx next = NEXT_INSN (insn); | |
3583 | register rtx prev = PREV_INSN (insn); | |
196cedd0 RS |
3584 | register int was_code_label = (GET_CODE (insn) == CODE_LABEL); |
3585 | register int dont_really_delete = 0; | |
15a63be1 RK |
3586 | |
3587 | while (next && INSN_DELETED_P (next)) | |
3588 | next = NEXT_INSN (next); | |
3589 | ||
3590 | /* This insn is already deleted => return first following nondeleted. */ | |
3591 | if (INSN_DELETED_P (insn)) | |
3592 | return next; | |
3593 | ||
196cedd0 RS |
3594 | /* Don't delete user-declared labels. Convert them to special NOTEs |
3595 | instead. */ | |
9571f079 RK |
3596 | if (was_code_label && LABEL_NAME (insn) != 0 |
3597 | && optimize && ! dont_really_delete) | |
196cedd0 RS |
3598 | { |
3599 | PUT_CODE (insn, NOTE); | |
3600 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED_LABEL; | |
3601 | NOTE_SOURCE_FILE (insn) = 0; | |
3602 | dont_really_delete = 1; | |
3603 | } | |
3604 | else | |
3605 | /* Mark this insn as deleted. */ | |
3606 | INSN_DELETED_P (insn) = 1; | |
15a63be1 RK |
3607 | |
3608 | /* If this is an unconditional jump, delete it from the jump chain. */ | |
3609 | if (simplejump_p (insn)) | |
3610 | delete_from_jump_chain (insn); | |
3611 | ||
3612 | /* If instruction is followed by a barrier, | |
3613 | delete the barrier too. */ | |
3614 | ||
3615 | if (next != 0 && GET_CODE (next) == BARRIER) | |
3616 | { | |
3617 | INSN_DELETED_P (next) = 1; | |
3618 | next = NEXT_INSN (next); | |
3619 | } | |
3620 | ||
3621 | /* Patch out INSN (and the barrier if any) */ | |
3622 | ||
196cedd0 | 3623 | if (optimize && ! dont_really_delete) |
15a63be1 RK |
3624 | { |
3625 | if (prev) | |
3626 | { | |
3627 | NEXT_INSN (prev) = next; | |
3628 | if (GET_CODE (prev) == INSN && GET_CODE (PATTERN (prev)) == SEQUENCE) | |
3629 | NEXT_INSN (XVECEXP (PATTERN (prev), 0, | |
3630 | XVECLEN (PATTERN (prev), 0) - 1)) = next; | |
3631 | } | |
3632 | ||
3633 | if (next) | |
3634 | { | |
3635 | PREV_INSN (next) = prev; | |
3636 | if (GET_CODE (next) == INSN && GET_CODE (PATTERN (next)) == SEQUENCE) | |
3637 | PREV_INSN (XVECEXP (PATTERN (next), 0, 0)) = prev; | |
3638 | } | |
3639 | ||
3640 | if (prev && NEXT_INSN (prev) == 0) | |
3641 | set_last_insn (prev); | |
3642 | } | |
3643 | ||
3644 | /* If deleting a jump, decrement the count of the label, | |
3645 | and delete the label if it is now unused. */ | |
3646 | ||
3647 | if (GET_CODE (insn) == JUMP_INSN && JUMP_LABEL (insn)) | |
3648 | if (--LABEL_NUSES (JUMP_LABEL (insn)) == 0) | |
3649 | { | |
3650 | /* This can delete NEXT or PREV, | |
3651 | either directly if NEXT is JUMP_LABEL (INSN), | |
3652 | or indirectly through more levels of jumps. */ | |
3653 | delete_insn (JUMP_LABEL (insn)); | |
3654 | /* I feel a little doubtful about this loop, | |
3655 | but I see no clean and sure alternative way | |
3656 | to find the first insn after INSN that is not now deleted. | |
3657 | I hope this works. */ | |
3658 | while (next && INSN_DELETED_P (next)) | |
3659 | next = NEXT_INSN (next); | |
3660 | return next; | |
3661 | } | |
3662 | ||
3c7d7a4a DE |
3663 | /* Likewise if we're deleting a dispatch table. */ |
3664 | ||
3665 | if (GET_CODE (insn) == JUMP_INSN | |
3666 | && (GET_CODE (PATTERN (insn)) == ADDR_VEC | |
3667 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)) | |
3668 | { | |
3669 | rtx pat = PATTERN (insn); | |
3670 | int i, diff_vec_p = GET_CODE (pat) == ADDR_DIFF_VEC; | |
3671 | int len = XVECLEN (pat, diff_vec_p); | |
3672 | ||
3673 | for (i = 0; i < len; i++) | |
3674 | if (--LABEL_NUSES (XEXP (XVECEXP (pat, diff_vec_p, i), 0)) == 0) | |
3675 | delete_insn (XEXP (XVECEXP (pat, diff_vec_p, i), 0)); | |
3676 | while (next && INSN_DELETED_P (next)) | |
3677 | next = NEXT_INSN (next); | |
3678 | return next; | |
3679 | } | |
3680 | ||
15a63be1 RK |
3681 | while (prev && (INSN_DELETED_P (prev) || GET_CODE (prev) == NOTE)) |
3682 | prev = PREV_INSN (prev); | |
3683 | ||
3684 | /* If INSN was a label and a dispatch table follows it, | |
3685 | delete the dispatch table. The tablejump must have gone already. | |
3686 | It isn't useful to fall through into a table. */ | |
3687 | ||
196cedd0 | 3688 | if (was_code_label |
15a63be1 RK |
3689 | && NEXT_INSN (insn) != 0 |
3690 | && GET_CODE (NEXT_INSN (insn)) == JUMP_INSN | |
3691 | && (GET_CODE (PATTERN (NEXT_INSN (insn))) == ADDR_VEC | |
3692 | || GET_CODE (PATTERN (NEXT_INSN (insn))) == ADDR_DIFF_VEC)) | |
3693 | next = delete_insn (NEXT_INSN (insn)); | |
3694 | ||
3695 | /* If INSN was a label, delete insns following it if now unreachable. */ | |
3696 | ||
196cedd0 | 3697 | if (was_code_label && prev && GET_CODE (prev) == BARRIER) |
15a63be1 RK |
3698 | { |
3699 | register RTX_CODE code; | |
3700 | while (next != 0 | |
8cd2aff2 | 3701 | && (GET_RTX_CLASS (code = GET_CODE (next)) == 'i' |
4134d7fc | 3702 | || code == NOTE || code == BARRIER |
2e1dbf22 | 3703 | || (code == CODE_LABEL && INSN_DELETED_P (next)))) |
15a63be1 RK |
3704 | { |
3705 | if (code == NOTE | |
3706 | && NOTE_LINE_NUMBER (next) != NOTE_INSN_FUNCTION_END) | |
3707 | next = NEXT_INSN (next); | |
2e1dbf22 RS |
3708 | /* Keep going past other deleted labels to delete what follows. */ |
3709 | else if (code == CODE_LABEL && INSN_DELETED_P (next)) | |
3710 | next = NEXT_INSN (next); | |
15a63be1 RK |
3711 | else |
3712 | /* Note: if this deletes a jump, it can cause more | |
3713 | deletion of unreachable code, after a different label. | |
3714 | As long as the value from this recursive call is correct, | |
3715 | this invocation functions correctly. */ | |
3716 | next = delete_insn (next); | |
3717 | } | |
3718 | } | |
3719 | ||
3720 | return next; | |
3721 | } | |
3722 | ||
3723 | /* Advance from INSN till reaching something not deleted | |
3724 | then return that. May return INSN itself. */ | |
3725 | ||
3726 | rtx | |
3727 | next_nondeleted_insn (insn) | |
3728 | rtx insn; | |
3729 | { | |
3730 | while (INSN_DELETED_P (insn)) | |
3731 | insn = NEXT_INSN (insn); | |
3732 | return insn; | |
3733 | } | |
3734 | \f | |
3735 | /* Delete a range of insns from FROM to TO, inclusive. | |
3736 | This is for the sake of peephole optimization, so assume | |
3737 | that whatever these insns do will still be done by a new | |
3738 | peephole insn that will replace them. */ | |
3739 | ||
3740 | void | |
3741 | delete_for_peephole (from, to) | |
3742 | register rtx from, to; | |
3743 | { | |
3744 | register rtx insn = from; | |
3745 | ||
3746 | while (1) | |
3747 | { | |
3748 | register rtx next = NEXT_INSN (insn); | |
3749 | register rtx prev = PREV_INSN (insn); | |
3750 | ||
3751 | if (GET_CODE (insn) != NOTE) | |
3752 | { | |
3753 | INSN_DELETED_P (insn) = 1; | |
3754 | ||
3755 | /* Patch this insn out of the chain. */ | |
3756 | /* We don't do this all at once, because we | |
3757 | must preserve all NOTEs. */ | |
3758 | if (prev) | |
3759 | NEXT_INSN (prev) = next; | |
3760 | ||
3761 | if (next) | |
3762 | PREV_INSN (next) = prev; | |
3763 | } | |
3764 | ||
3765 | if (insn == to) | |
3766 | break; | |
3767 | insn = next; | |
3768 | } | |
3769 | ||
3770 | /* Note that if TO is an unconditional jump | |
3771 | we *do not* delete the BARRIER that follows, | |
3772 | since the peephole that replaces this sequence | |
3773 | is also an unconditional jump in that case. */ | |
3774 | } | |
3775 | \f | |
3776 | /* Invert the condition of the jump JUMP, and make it jump | |
3777 | to label NLABEL instead of where it jumps now. */ | |
3778 | ||
3779 | int | |
3780 | invert_jump (jump, nlabel) | |
3781 | rtx jump, nlabel; | |
3782 | { | |
15a63be1 RK |
3783 | /* We have to either invert the condition and change the label or |
3784 | do neither. Either operation could fail. We first try to invert | |
3785 | the jump. If that succeeds, we try changing the label. If that fails, | |
3786 | we invert the jump back to what it was. */ | |
3787 | ||
3788 | if (! invert_exp (PATTERN (jump), jump)) | |
3789 | return 0; | |
3790 | ||
3791 | if (redirect_jump (jump, nlabel)) | |
f6a6a1b3 DE |
3792 | { |
3793 | if (flag_branch_probabilities) | |
3794 | { | |
3795 | rtx note = find_reg_note (jump, REG_BR_PROB, 0); | |
3796 | ||
3797 | /* An inverted jump means that a probability taken becomes a | |
3798 | probability not taken. Subtract the branch probability from the | |
3799 | probability base to convert it back to a taken probability. | |
3800 | (We don't flip the probability on a branch that's never taken. */ | |
3801 | if (note && XINT (XEXP (note, 0), 0) >= 0) | |
3802 | XINT (XEXP (note, 0), 0) = REG_BR_PROB_BASE - XINT (XEXP (note, 0), 0); | |
3803 | } | |
3804 | ||
3805 | return 1; | |
3806 | } | |
15a63be1 RK |
3807 | |
3808 | if (! invert_exp (PATTERN (jump), jump)) | |
3809 | /* This should just be putting it back the way it was. */ | |
3810 | abort (); | |
3811 | ||
3812 | return 0; | |
3813 | } | |
3814 | ||
3815 | /* Invert the jump condition of rtx X contained in jump insn, INSN. | |
3816 | ||
3817 | Return 1 if we can do so, 0 if we cannot find a way to do so that | |
3818 | matches a pattern. */ | |
3819 | ||
4214a505 | 3820 | int |
15a63be1 RK |
3821 | invert_exp (x, insn) |
3822 | rtx x; | |
3823 | rtx insn; | |
3824 | { | |
3825 | register RTX_CODE code; | |
3826 | register int i; | |
3827 | register char *fmt; | |
3828 | ||
3829 | code = GET_CODE (x); | |
3830 | ||
3831 | if (code == IF_THEN_ELSE) | |
3832 | { | |
3833 | register rtx comp = XEXP (x, 0); | |
3834 | register rtx tem; | |
3835 | ||
3836 | /* We can do this in two ways: The preferable way, which can only | |
3837 | be done if this is not an integer comparison, is to reverse | |
3838 | the comparison code. Otherwise, swap the THEN-part and ELSE-part | |
3839 | of the IF_THEN_ELSE. If we can't do either, fail. */ | |
3840 | ||
3841 | if (can_reverse_comparison_p (comp, insn) | |
3842 | && validate_change (insn, &XEXP (x, 0), | |
3843 | gen_rtx (reverse_condition (GET_CODE (comp)), | |
3844 | GET_MODE (comp), XEXP (comp, 0), | |
3845 | XEXP (comp, 1)), 0)) | |
3846 | return 1; | |
3847 | ||
3848 | tem = XEXP (x, 1); | |
3849 | validate_change (insn, &XEXP (x, 1), XEXP (x, 2), 1); | |
3850 | validate_change (insn, &XEXP (x, 2), tem, 1); | |
3851 | return apply_change_group (); | |
3852 | } | |
3853 | ||
3854 | fmt = GET_RTX_FORMAT (code); | |
3855 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
3856 | { | |
3857 | if (fmt[i] == 'e') | |
3858 | if (! invert_exp (XEXP (x, i), insn)) | |
3859 | return 0; | |
3860 | if (fmt[i] == 'E') | |
3861 | { | |
3862 | register int j; | |
3863 | for (j = 0; j < XVECLEN (x, i); j++) | |
3864 | if (!invert_exp (XVECEXP (x, i, j), insn)) | |
3865 | return 0; | |
3866 | } | |
3867 | } | |
3868 | ||
3869 | return 1; | |
3870 | } | |
3871 | \f | |
3872 | /* Make jump JUMP jump to label NLABEL instead of where it jumps now. | |
3873 | If the old jump target label is unused as a result, | |
3874 | it and the code following it may be deleted. | |
3875 | ||
3876 | If NLABEL is zero, we are to turn the jump into a (possibly conditional) | |
3877 | RETURN insn. | |
3878 | ||
3879 | The return value will be 1 if the change was made, 0 if it wasn't (this | |
3880 | can only occur for NLABEL == 0). */ | |
3881 | ||
3882 | int | |
3883 | redirect_jump (jump, nlabel) | |
3884 | rtx jump, nlabel; | |
3885 | { | |
3886 | register rtx olabel = JUMP_LABEL (jump); | |
3887 | ||
3888 | if (nlabel == olabel) | |
3889 | return 1; | |
3890 | ||
3891 | if (! redirect_exp (&PATTERN (jump), olabel, nlabel, jump)) | |
3892 | return 0; | |
3893 | ||
3894 | /* If this is an unconditional branch, delete it from the jump_chain of | |
3895 | OLABEL and add it to the jump_chain of NLABEL (assuming both labels | |
3896 | have UID's in range and JUMP_CHAIN is valid). */ | |
3897 | if (jump_chain && (simplejump_p (jump) | |
3898 | || GET_CODE (PATTERN (jump)) == RETURN)) | |
3899 | { | |
3900 | int label_index = nlabel ? INSN_UID (nlabel) : 0; | |
3901 | ||
3902 | delete_from_jump_chain (jump); | |
2d20b9df RS |
3903 | if (label_index < max_jump_chain |
3904 | && INSN_UID (jump) < max_jump_chain) | |
15a63be1 RK |
3905 | { |
3906 | jump_chain[INSN_UID (jump)] = jump_chain[label_index]; | |
3907 | jump_chain[label_index] = jump; | |
3908 | } | |
3909 | } | |
3910 | ||
3911 | JUMP_LABEL (jump) = nlabel; | |
3912 | if (nlabel) | |
3913 | ++LABEL_NUSES (nlabel); | |
3914 | ||
3915 | if (olabel && --LABEL_NUSES (olabel) == 0) | |
3916 | delete_insn (olabel); | |
3917 | ||
3918 | return 1; | |
3919 | } | |
3920 | ||
3921 | /* Delete the instruction JUMP from any jump chain it might be on. */ | |
3922 | ||
3923 | static void | |
3924 | delete_from_jump_chain (jump) | |
3925 | rtx jump; | |
3926 | { | |
3927 | int index; | |
3928 | rtx olabel = JUMP_LABEL (jump); | |
3929 | ||
3930 | /* Handle unconditional jumps. */ | |
3931 | if (jump_chain && olabel != 0 | |
3932 | && INSN_UID (olabel) < max_jump_chain | |
3933 | && simplejump_p (jump)) | |
3934 | index = INSN_UID (olabel); | |
3935 | /* Handle return insns. */ | |
3936 | else if (jump_chain && GET_CODE (PATTERN (jump)) == RETURN) | |
3937 | index = 0; | |
3938 | else return; | |
3939 | ||
3940 | if (jump_chain[index] == jump) | |
3941 | jump_chain[index] = jump_chain[INSN_UID (jump)]; | |
3942 | else | |
3943 | { | |
3944 | rtx insn; | |
3945 | ||
3946 | for (insn = jump_chain[index]; | |
3947 | insn != 0; | |
3948 | insn = jump_chain[INSN_UID (insn)]) | |
3949 | if (jump_chain[INSN_UID (insn)] == jump) | |
3950 | { | |
3951 | jump_chain[INSN_UID (insn)] = jump_chain[INSN_UID (jump)]; | |
3952 | break; | |
3953 | } | |
3954 | } | |
3955 | } | |
3956 | ||
3957 | /* If NLABEL is nonzero, throughout the rtx at LOC, | |
3958 | alter (LABEL_REF OLABEL) to (LABEL_REF NLABEL). If OLABEL is | |
3959 | zero, alter (RETURN) to (LABEL_REF NLABEL). | |
3960 | ||
3961 | If NLABEL is zero, alter (LABEL_REF OLABEL) to (RETURN) and check | |
3962 | validity with validate_change. Convert (set (pc) (label_ref olabel)) | |
3963 | to (return). | |
3964 | ||
3965 | Return 0 if we found a change we would like to make but it is invalid. | |
3966 | Otherwise, return 1. */ | |
3967 | ||
4214a505 | 3968 | int |
15a63be1 RK |
3969 | redirect_exp (loc, olabel, nlabel, insn) |
3970 | rtx *loc; | |
3971 | rtx olabel, nlabel; | |
3972 | rtx insn; | |
3973 | { | |
3974 | register rtx x = *loc; | |
3975 | register RTX_CODE code = GET_CODE (x); | |
3976 | register int i; | |
3977 | register char *fmt; | |
3978 | ||
3979 | if (code == LABEL_REF) | |
3980 | { | |
3981 | if (XEXP (x, 0) == olabel) | |
3982 | { | |
3983 | if (nlabel) | |
3984 | XEXP (x, 0) = nlabel; | |
3985 | else | |
3986 | return validate_change (insn, loc, gen_rtx (RETURN, VOIDmode), 0); | |
3987 | return 1; | |
3988 | } | |
3989 | } | |
3990 | else if (code == RETURN && olabel == 0) | |
3991 | { | |
3992 | x = gen_rtx (LABEL_REF, VOIDmode, nlabel); | |
3993 | if (loc == &PATTERN (insn)) | |
3994 | x = gen_rtx (SET, VOIDmode, pc_rtx, x); | |
3995 | return validate_change (insn, loc, x, 0); | |
3996 | } | |
3997 | ||
3998 | if (code == SET && nlabel == 0 && SET_DEST (x) == pc_rtx | |
3999 | && GET_CODE (SET_SRC (x)) == LABEL_REF | |
4000 | && XEXP (SET_SRC (x), 0) == olabel) | |
4001 | return validate_change (insn, loc, gen_rtx (RETURN, VOIDmode), 0); | |
4002 | ||
4003 | fmt = GET_RTX_FORMAT (code); | |
4004 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
4005 | { | |
4006 | if (fmt[i] == 'e') | |
4007 | if (! redirect_exp (&XEXP (x, i), olabel, nlabel, insn)) | |
4008 | return 0; | |
4009 | if (fmt[i] == 'E') | |
4010 | { | |
4011 | register int j; | |
4012 | for (j = 0; j < XVECLEN (x, i); j++) | |
4013 | if (! redirect_exp (&XVECEXP (x, i, j), olabel, nlabel, insn)) | |
4014 | return 0; | |
4015 | } | |
4016 | } | |
4017 | ||
4018 | return 1; | |
4019 | } | |
4020 | \f | |
4021 | /* Make jump JUMP jump to label NLABEL, assuming it used to be a tablejump. | |
4022 | ||
4023 | If the old jump target label (before the dispatch table) becomes unused, | |
4024 | it and the dispatch table may be deleted. In that case, find the insn | |
6dc42e49 | 4025 | before the jump references that label and delete it and logical successors |
15a63be1 RK |
4026 | too. */ |
4027 | ||
8cd2aff2 | 4028 | static void |
15a63be1 RK |
4029 | redirect_tablejump (jump, nlabel) |
4030 | rtx jump, nlabel; | |
4031 | { | |
4032 | register rtx olabel = JUMP_LABEL (jump); | |
4033 | ||
4034 | /* Add this jump to the jump_chain of NLABEL. */ | |
4035 | if (jump_chain && INSN_UID (nlabel) < max_jump_chain | |
4036 | && INSN_UID (jump) < max_jump_chain) | |
4037 | { | |
4038 | jump_chain[INSN_UID (jump)] = jump_chain[INSN_UID (nlabel)]; | |
4039 | jump_chain[INSN_UID (nlabel)] = jump; | |
4040 | } | |
4041 | ||
4042 | PATTERN (jump) = gen_jump (nlabel); | |
4043 | JUMP_LABEL (jump) = nlabel; | |
4044 | ++LABEL_NUSES (nlabel); | |
4045 | INSN_CODE (jump) = -1; | |
4046 | ||
4047 | if (--LABEL_NUSES (olabel) == 0) | |
4048 | { | |
4049 | delete_labelref_insn (jump, olabel, 0); | |
4050 | delete_insn (olabel); | |
4051 | } | |
4052 | } | |
4053 | ||
4054 | /* Find the insn referencing LABEL that is a logical predecessor of INSN. | |
4055 | If we found one, delete it and then delete this insn if DELETE_THIS is | |
4056 | non-zero. Return non-zero if INSN or a predecessor references LABEL. */ | |
4057 | ||
4058 | static int | |
4059 | delete_labelref_insn (insn, label, delete_this) | |
4060 | rtx insn, label; | |
4061 | int delete_this; | |
4062 | { | |
4063 | int deleted = 0; | |
4064 | rtx link; | |
4065 | ||
4066 | if (GET_CODE (insn) != NOTE | |
4067 | && reg_mentioned_p (label, PATTERN (insn))) | |
4068 | { | |
4069 | if (delete_this) | |
4070 | { | |
4071 | delete_insn (insn); | |
4072 | deleted = 1; | |
4073 | } | |
4074 | else | |
4075 | return 1; | |
4076 | } | |
4077 | ||
4078 | for (link = LOG_LINKS (insn); link; link = XEXP (link, 1)) | |
4079 | if (delete_labelref_insn (XEXP (link, 0), label, 1)) | |
4080 | { | |
4081 | if (delete_this) | |
4082 | { | |
4083 | delete_insn (insn); | |
4084 | deleted = 1; | |
4085 | } | |
4086 | else | |
4087 | return 1; | |
4088 | } | |
4089 | ||
4090 | return deleted; | |
4091 | } | |
4092 | \f | |
4093 | /* Like rtx_equal_p except that it considers two REGs as equal | |
4fe73cc1 RK |
4094 | if they renumber to the same value and considers two commutative |
4095 | operations to be the same if the order of the operands has been | |
4096 | reversed. */ | |
15a63be1 RK |
4097 | |
4098 | int | |
4099 | rtx_renumbered_equal_p (x, y) | |
4100 | rtx x, y; | |
4101 | { | |
4102 | register int i; | |
4103 | register RTX_CODE code = GET_CODE (x); | |
4104 | register char *fmt; | |
4105 | ||
4106 | if (x == y) | |
4107 | return 1; | |
4fe73cc1 | 4108 | |
15a63be1 RK |
4109 | if ((code == REG || (code == SUBREG && GET_CODE (SUBREG_REG (x)) == REG)) |
4110 | && (GET_CODE (y) == REG || (GET_CODE (y) == SUBREG | |
4111 | && GET_CODE (SUBREG_REG (y)) == REG))) | |
4112 | { | |
4fe73cc1 RK |
4113 | int reg_x = -1, reg_y = -1; |
4114 | int word_x = 0, word_y = 0; | |
15a63be1 RK |
4115 | |
4116 | if (GET_MODE (x) != GET_MODE (y)) | |
4117 | return 0; | |
4118 | ||
4119 | /* If we haven't done any renumbering, don't | |
4120 | make any assumptions. */ | |
4121 | if (reg_renumber == 0) | |
4122 | return rtx_equal_p (x, y); | |
4123 | ||
4124 | if (code == SUBREG) | |
4125 | { | |
4fe73cc1 RK |
4126 | reg_x = REGNO (SUBREG_REG (x)); |
4127 | word_x = SUBREG_WORD (x); | |
4128 | ||
4129 | if (reg_renumber[reg_x] >= 0) | |
4130 | { | |
4131 | reg_x = reg_renumber[reg_x] + word_x; | |
4132 | word_x = 0; | |
4133 | } | |
15a63be1 | 4134 | } |
4fe73cc1 | 4135 | |
15a63be1 RK |
4136 | else |
4137 | { | |
4fe73cc1 RK |
4138 | reg_x = REGNO (x); |
4139 | if (reg_renumber[reg_x] >= 0) | |
4140 | reg_x = reg_renumber[reg_x]; | |
15a63be1 | 4141 | } |
4fe73cc1 | 4142 | |
15a63be1 RK |
4143 | if (GET_CODE (y) == SUBREG) |
4144 | { | |
4fe73cc1 RK |
4145 | reg_y = REGNO (SUBREG_REG (y)); |
4146 | word_y = SUBREG_WORD (y); | |
4147 | ||
4148 | if (reg_renumber[reg_y] >= 0) | |
4149 | { | |
4150 | reg_y = reg_renumber[reg_y]; | |
4151 | word_y = 0; | |
4152 | } | |
15a63be1 | 4153 | } |
4fe73cc1 | 4154 | |
15a63be1 RK |
4155 | else |
4156 | { | |
4fe73cc1 RK |
4157 | reg_y = REGNO (y); |
4158 | if (reg_renumber[reg_y] >= 0) | |
4159 | reg_y = reg_renumber[reg_y]; | |
15a63be1 | 4160 | } |
4fe73cc1 RK |
4161 | |
4162 | return reg_x >= 0 && reg_x == reg_y && word_x == word_y; | |
15a63be1 | 4163 | } |
4fe73cc1 | 4164 | |
15a63be1 RK |
4165 | /* Now we have disposed of all the cases |
4166 | in which different rtx codes can match. */ | |
4167 | if (code != GET_CODE (y)) | |
4168 | return 0; | |
4fe73cc1 | 4169 | |
15a63be1 RK |
4170 | switch (code) |
4171 | { | |
4172 | case PC: | |
4173 | case CC0: | |
4174 | case ADDR_VEC: | |
4175 | case ADDR_DIFF_VEC: | |
4176 | return 0; | |
4177 | ||
4178 | case CONST_INT: | |
38b3167e | 4179 | return INTVAL (x) == INTVAL (y); |
15a63be1 RK |
4180 | |
4181 | case LABEL_REF: | |
705f26cf RS |
4182 | /* We can't assume nonlocal labels have their following insns yet. */ |
4183 | if (LABEL_REF_NONLOCAL_P (x) || LABEL_REF_NONLOCAL_P (y)) | |
4184 | return XEXP (x, 0) == XEXP (y, 0); | |
4fe73cc1 | 4185 | |
15a63be1 RK |
4186 | /* Two label-refs are equivalent if they point at labels |
4187 | in the same position in the instruction stream. */ | |
4188 | return (next_real_insn (XEXP (x, 0)) | |
4189 | == next_real_insn (XEXP (y, 0))); | |
4190 | ||
4191 | case SYMBOL_REF: | |
4192 | return XSTR (x, 0) == XSTR (y, 0); | |
e9a25f70 JL |
4193 | |
4194 | default: | |
4195 | break; | |
15a63be1 RK |
4196 | } |
4197 | ||
4198 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. */ | |
4199 | ||
4200 | if (GET_MODE (x) != GET_MODE (y)) | |
4201 | return 0; | |
4202 | ||
4fe73cc1 RK |
4203 | /* For commutative operations, the RTX match if the operand match in any |
4204 | order. Also handle the simple binary and unary cases without a loop. */ | |
4205 | if (code == EQ || code == NE || GET_RTX_CLASS (code) == 'c') | |
4206 | return ((rtx_renumbered_equal_p (XEXP (x, 0), XEXP (y, 0)) | |
4207 | && rtx_renumbered_equal_p (XEXP (x, 1), XEXP (y, 1))) | |
4208 | || (rtx_renumbered_equal_p (XEXP (x, 0), XEXP (y, 1)) | |
4209 | && rtx_renumbered_equal_p (XEXP (x, 1), XEXP (y, 0)))); | |
4210 | else if (GET_RTX_CLASS (code) == '<' || GET_RTX_CLASS (code) == '2') | |
4211 | return (rtx_renumbered_equal_p (XEXP (x, 0), XEXP (y, 0)) | |
4212 | && rtx_renumbered_equal_p (XEXP (x, 1), XEXP (y, 1))); | |
4213 | else if (GET_RTX_CLASS (code) == '1') | |
4214 | return rtx_renumbered_equal_p (XEXP (x, 0), XEXP (y, 0)); | |
4215 | ||
15a63be1 RK |
4216 | /* Compare the elements. If any pair of corresponding elements |
4217 | fail to match, return 0 for the whole things. */ | |
4218 | ||
4219 | fmt = GET_RTX_FORMAT (code); | |
4220 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
4221 | { | |
4222 | register int j; | |
4223 | switch (fmt[i]) | |
4224 | { | |
5f4f0e22 CH |
4225 | case 'w': |
4226 | if (XWINT (x, i) != XWINT (y, i)) | |
4227 | return 0; | |
4228 | break; | |
4229 | ||
15a63be1 RK |
4230 | case 'i': |
4231 | if (XINT (x, i) != XINT (y, i)) | |
4232 | return 0; | |
4233 | break; | |
4234 | ||
4235 | case 's': | |
4236 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
4237 | return 0; | |
4238 | break; | |
4239 | ||
4240 | case 'e': | |
4241 | if (! rtx_renumbered_equal_p (XEXP (x, i), XEXP (y, i))) | |
4242 | return 0; | |
4243 | break; | |
4244 | ||
4245 | case 'u': | |
4246 | if (XEXP (x, i) != XEXP (y, i)) | |
4247 | return 0; | |
4248 | /* fall through. */ | |
4249 | case '0': | |
4250 | break; | |
4251 | ||
4252 | case 'E': | |
4253 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
4254 | return 0; | |
4255 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
4256 | if (!rtx_renumbered_equal_p (XVECEXP (x, i, j), XVECEXP (y, i, j))) | |
4257 | return 0; | |
4258 | break; | |
4259 | ||
4260 | default: | |
4261 | abort (); | |
4262 | } | |
4263 | } | |
4264 | return 1; | |
4265 | } | |
4266 | \f | |
4267 | /* If X is a hard register or equivalent to one or a subregister of one, | |
4268 | return the hard register number. If X is a pseudo register that was not | |
4269 | assigned a hard register, return the pseudo register number. Otherwise, | |
4270 | return -1. Any rtx is valid for X. */ | |
4271 | ||
4272 | int | |
4273 | true_regnum (x) | |
4274 | rtx x; | |
4275 | { | |
4276 | if (GET_CODE (x) == REG) | |
4277 | { | |
4278 | if (REGNO (x) >= FIRST_PSEUDO_REGISTER && reg_renumber[REGNO (x)] >= 0) | |
4279 | return reg_renumber[REGNO (x)]; | |
4280 | return REGNO (x); | |
4281 | } | |
4282 | if (GET_CODE (x) == SUBREG) | |
4283 | { | |
4284 | int base = true_regnum (SUBREG_REG (x)); | |
4285 | if (base >= 0 && base < FIRST_PSEUDO_REGISTER) | |
4286 | return SUBREG_WORD (x) + base; | |
4287 | } | |
4288 | return -1; | |
4289 | } | |
4290 | \f | |
4291 | /* Optimize code of the form: | |
4292 | ||
4293 | for (x = a[i]; x; ...) | |
4294 | ... | |
4295 | for (x = a[i]; x; ...) | |
4296 | ... | |
4297 | foo: | |
4298 | ||
4299 | Loop optimize will change the above code into | |
4300 | ||
4301 | if (x = a[i]) | |
4302 | for (;;) | |
4303 | { ...; if (! (x = ...)) break; } | |
4304 | if (x = a[i]) | |
4305 | for (;;) | |
4306 | { ...; if (! (x = ...)) break; } | |
4307 | foo: | |
4308 | ||
4309 | In general, if the first test fails, the program can branch | |
4310 | directly to `foo' and skip the second try which is doomed to fail. | |
4311 | We run this after loop optimization and before flow analysis. */ | |
4312 | ||
4313 | /* When comparing the insn patterns, we track the fact that different | |
4314 | pseudo-register numbers may have been used in each computation. | |
4315 | The following array stores an equivalence -- same_regs[I] == J means | |
4316 | that pseudo register I was used in the first set of tests in a context | |
4317 | where J was used in the second set. We also count the number of such | |
4318 | pending equivalences. If nonzero, the expressions really aren't the | |
4319 | same. */ | |
4320 | ||
7ee8a9d5 | 4321 | static int *same_regs; |
15a63be1 RK |
4322 | |
4323 | static int num_same_regs; | |
4324 | ||
4325 | /* Track any registers modified between the target of the first jump and | |
4326 | the second jump. They never compare equal. */ | |
4327 | ||
4328 | static char *modified_regs; | |
4329 | ||
4330 | /* Record if memory was modified. */ | |
4331 | ||
4332 | static int modified_mem; | |
4333 | ||
4334 | /* Called via note_stores on each insn between the target of the first | |
4335 | branch and the second branch. It marks any changed registers. */ | |
4336 | ||
4337 | static void | |
4338 | mark_modified_reg (dest, x) | |
4339 | rtx dest; | |
4340 | rtx x; | |
4341 | { | |
4342 | int regno, i; | |
4343 | ||
4344 | if (GET_CODE (dest) == SUBREG) | |
4345 | dest = SUBREG_REG (dest); | |
4346 | ||
4347 | if (GET_CODE (dest) == MEM) | |
4348 | modified_mem = 1; | |
4349 | ||
4350 | if (GET_CODE (dest) != REG) | |
4351 | return; | |
4352 | ||
4353 | regno = REGNO (dest); | |
4354 | if (regno >= FIRST_PSEUDO_REGISTER) | |
4355 | modified_regs[regno] = 1; | |
4356 | else | |
4357 | for (i = 0; i < HARD_REGNO_NREGS (regno, GET_MODE (dest)); i++) | |
4358 | modified_regs[regno + i] = 1; | |
4359 | } | |
4360 | ||
4361 | /* F is the first insn in the chain of insns. */ | |
4362 | ||
4363 | void | |
aa38b201 | 4364 | thread_jumps (f, max_reg, flag_before_loop) |
15a63be1 RK |
4365 | rtx f; |
4366 | int max_reg; | |
aa38b201 | 4367 | int flag_before_loop; |
15a63be1 RK |
4368 | { |
4369 | /* Basic algorithm is to find a conditional branch, | |
4370 | the label it may branch to, and the branch after | |
4371 | that label. If the two branches test the same condition, | |
4372 | walk back from both branch paths until the insn patterns | |
4373 | differ, or code labels are hit. If we make it back to | |
4374 | the target of the first branch, then we know that the first branch | |
4375 | will either always succeed or always fail depending on the relative | |
4376 | senses of the two branches. So adjust the first branch accordingly | |
4377 | in this case. */ | |
4378 | ||
4379 | rtx label, b1, b2, t1, t2; | |
4380 | enum rtx_code code1, code2; | |
4381 | rtx b1op0, b1op1, b2op0, b2op1; | |
4382 | int changed = 1; | |
4383 | int i; | |
7ee8a9d5 | 4384 | int *all_reset; |
15a63be1 RK |
4385 | |
4386 | /* Allocate register tables and quick-reset table. */ | |
4387 | modified_regs = (char *) alloca (max_reg * sizeof (char)); | |
7ee8a9d5 RK |
4388 | same_regs = (int *) alloca (max_reg * sizeof (int)); |
4389 | all_reset = (int *) alloca (max_reg * sizeof (int)); | |
15a63be1 RK |
4390 | for (i = 0; i < max_reg; i++) |
4391 | all_reset[i] = -1; | |
4392 | ||
4393 | while (changed) | |
4394 | { | |
4395 | changed = 0; | |
4396 | ||
4397 | for (b1 = f; b1; b1 = NEXT_INSN (b1)) | |
4398 | { | |
4399 | /* Get to a candidate branch insn. */ | |
4400 | if (GET_CODE (b1) != JUMP_INSN | |
4401 | || ! condjump_p (b1) || simplejump_p (b1) | |
4402 | || JUMP_LABEL (b1) == 0) | |
4403 | continue; | |
4404 | ||
4405 | bzero (modified_regs, max_reg * sizeof (char)); | |
4406 | modified_mem = 0; | |
4407 | ||
4c9a05bc RK |
4408 | bcopy ((char *) all_reset, (char *) same_regs, |
4409 | max_reg * sizeof (int)); | |
15a63be1 RK |
4410 | num_same_regs = 0; |
4411 | ||
4412 | label = JUMP_LABEL (b1); | |
4413 | ||
4414 | /* Look for a branch after the target. Record any registers and | |
4415 | memory modified between the target and the branch. Stop when we | |
4416 | get to a label since we can't know what was changed there. */ | |
4417 | for (b2 = NEXT_INSN (label); b2; b2 = NEXT_INSN (b2)) | |
4418 | { | |
4419 | if (GET_CODE (b2) == CODE_LABEL) | |
4420 | break; | |
4421 | ||
4422 | else if (GET_CODE (b2) == JUMP_INSN) | |
4423 | { | |
4424 | /* If this is an unconditional jump and is the only use of | |
4425 | its target label, we can follow it. */ | |
4426 | if (simplejump_p (b2) | |
4427 | && JUMP_LABEL (b2) != 0 | |
4428 | && LABEL_NUSES (JUMP_LABEL (b2)) == 1) | |
4429 | { | |
4430 | b2 = JUMP_LABEL (b2); | |
4431 | continue; | |
4432 | } | |
4433 | else | |
4434 | break; | |
4435 | } | |
4436 | ||
4437 | if (GET_CODE (b2) != CALL_INSN && GET_CODE (b2) != INSN) | |
4438 | continue; | |
4439 | ||
4440 | if (GET_CODE (b2) == CALL_INSN) | |
4441 | { | |
4442 | modified_mem = 1; | |
4443 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
4444 | if (call_used_regs[i] && ! fixed_regs[i] | |
4445 | && i != STACK_POINTER_REGNUM | |
4446 | && i != FRAME_POINTER_REGNUM | |
cbe23927 | 4447 | && i != HARD_FRAME_POINTER_REGNUM |
15a63be1 RK |
4448 | && i != ARG_POINTER_REGNUM) |
4449 | modified_regs[i] = 1; | |
4450 | } | |
4451 | ||
4452 | note_stores (PATTERN (b2), mark_modified_reg); | |
4453 | } | |
4454 | ||
4455 | /* Check the next candidate branch insn from the label | |
4456 | of the first. */ | |
4457 | if (b2 == 0 | |
4458 | || GET_CODE (b2) != JUMP_INSN | |
4459 | || b2 == b1 | |
4460 | || ! condjump_p (b2) | |
4461 | || simplejump_p (b2)) | |
4462 | continue; | |
4463 | ||
4464 | /* Get the comparison codes and operands, reversing the | |
4465 | codes if appropriate. If we don't have comparison codes, | |
4466 | we can't do anything. */ | |
4467 | b1op0 = XEXP (XEXP (SET_SRC (PATTERN (b1)), 0), 0); | |
4468 | b1op1 = XEXP (XEXP (SET_SRC (PATTERN (b1)), 0), 1); | |
4469 | code1 = GET_CODE (XEXP (SET_SRC (PATTERN (b1)), 0)); | |
4470 | if (XEXP (SET_SRC (PATTERN (b1)), 1) == pc_rtx) | |
4471 | code1 = reverse_condition (code1); | |
4472 | ||
4473 | b2op0 = XEXP (XEXP (SET_SRC (PATTERN (b2)), 0), 0); | |
4474 | b2op1 = XEXP (XEXP (SET_SRC (PATTERN (b2)), 0), 1); | |
4475 | code2 = GET_CODE (XEXP (SET_SRC (PATTERN (b2)), 0)); | |
4476 | if (XEXP (SET_SRC (PATTERN (b2)), 1) == pc_rtx) | |
4477 | code2 = reverse_condition (code2); | |
4478 | ||
4479 | /* If they test the same things and knowing that B1 branches | |
4480 | tells us whether or not B2 branches, check if we | |
4481 | can thread the branch. */ | |
4482 | if (rtx_equal_for_thread_p (b1op0, b2op0, b2) | |
4483 | && rtx_equal_for_thread_p (b1op1, b2op1, b2) | |
4484 | && (comparison_dominates_p (code1, code2) | |
cc5e1642 R |
4485 | || (comparison_dominates_p (code1, reverse_condition (code2)) |
4486 | && can_reverse_comparison_p (XEXP (SET_SRC (PATTERN (b1)), | |
4487 | 0), | |
4488 | b1)))) | |
15a63be1 RK |
4489 | { |
4490 | t1 = prev_nonnote_insn (b1); | |
4491 | t2 = prev_nonnote_insn (b2); | |
4492 | ||
4493 | while (t1 != 0 && t2 != 0) | |
4494 | { | |
15a63be1 RK |
4495 | if (t2 == label) |
4496 | { | |
4497 | /* We have reached the target of the first branch. | |
4498 | If there are no pending register equivalents, | |
4499 | we know that this branch will either always | |
4500 | succeed (if the senses of the two branches are | |
4501 | the same) or always fail (if not). */ | |
4502 | rtx new_label; | |
4503 | ||
4504 | if (num_same_regs != 0) | |
4505 | break; | |
4506 | ||
4507 | if (comparison_dominates_p (code1, code2)) | |
4508 | new_label = JUMP_LABEL (b2); | |
4509 | else | |
4510 | new_label = get_label_after (b2); | |
4511 | ||
aa38b201 TG |
4512 | if (JUMP_LABEL (b1) != new_label) |
4513 | { | |
4514 | rtx prev = PREV_INSN (new_label); | |
4515 | ||
4516 | if (flag_before_loop | |
4517 | && NOTE_LINE_NUMBER (prev) == NOTE_INSN_LOOP_BEG) | |
4518 | { | |
4519 | /* Don't thread to the loop label. If a loop | |
4520 | label is reused, loop optimization will | |
4521 | be disabled for that loop. */ | |
4522 | new_label = gen_label_rtx (); | |
4523 | emit_label_after (new_label, PREV_INSN (prev)); | |
4524 | } | |
4525 | changed |= redirect_jump (b1, new_label); | |
4526 | } | |
15a63be1 RK |
4527 | break; |
4528 | } | |
4529 | ||
4530 | /* If either of these is not a normal insn (it might be | |
4531 | a JUMP_INSN, CALL_INSN, or CODE_LABEL) we fail. (NOTEs | |
4532 | have already been skipped above.) Similarly, fail | |
4533 | if the insns are different. */ | |
4534 | if (GET_CODE (t1) != INSN || GET_CODE (t2) != INSN | |
4535 | || recog_memoized (t1) != recog_memoized (t2) | |
4536 | || ! rtx_equal_for_thread_p (PATTERN (t1), | |
4537 | PATTERN (t2), t2)) | |
4538 | break; | |
4539 | ||
4540 | t1 = prev_nonnote_insn (t1); | |
4541 | t2 = prev_nonnote_insn (t2); | |
4542 | } | |
4543 | } | |
4544 | } | |
4545 | } | |
4546 | } | |
4547 | \f | |
4548 | /* This is like RTX_EQUAL_P except that it knows about our handling of | |
4549 | possibly equivalent registers and knows to consider volatile and | |
4550 | modified objects as not equal. | |
4551 | ||
4552 | YINSN is the insn containing Y. */ | |
4553 | ||
4554 | int | |
4555 | rtx_equal_for_thread_p (x, y, yinsn) | |
4556 | rtx x, y; | |
4557 | rtx yinsn; | |
4558 | { | |
4559 | register int i; | |
4560 | register int j; | |
4561 | register enum rtx_code code; | |
4562 | register char *fmt; | |
4563 | ||
4564 | code = GET_CODE (x); | |
4565 | /* Rtx's of different codes cannot be equal. */ | |
4566 | if (code != GET_CODE (y)) | |
4567 | return 0; | |
4568 | ||
4569 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. | |
4570 | (REG:SI x) and (REG:HI x) are NOT equivalent. */ | |
4571 | ||
4572 | if (GET_MODE (x) != GET_MODE (y)) | |
4573 | return 0; | |
4574 | ||
35d9eabb RK |
4575 | /* For floating-point, consider everything unequal. This is a bit |
4576 | pessimistic, but this pass would only rarely do anything for FP | |
4577 | anyway. */ | |
4578 | if (TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT | |
4579 | && FLOAT_MODE_P (GET_MODE (x)) && ! flag_fast_math) | |
4580 | return 0; | |
4581 | ||
413c72c2 RK |
4582 | /* For commutative operations, the RTX match if the operand match in any |
4583 | order. Also handle the simple binary and unary cases without a loop. */ | |
4584 | if (code == EQ || code == NE || GET_RTX_CLASS (code) == 'c') | |
c5ea5f3b RK |
4585 | return ((rtx_equal_for_thread_p (XEXP (x, 0), XEXP (y, 0), yinsn) |
4586 | && rtx_equal_for_thread_p (XEXP (x, 1), XEXP (y, 1), yinsn)) | |
4587 | || (rtx_equal_for_thread_p (XEXP (x, 0), XEXP (y, 1), yinsn) | |
4588 | && rtx_equal_for_thread_p (XEXP (x, 1), XEXP (y, 0), yinsn))); | |
413c72c2 | 4589 | else if (GET_RTX_CLASS (code) == '<' || GET_RTX_CLASS (code) == '2') |
c5ea5f3b RK |
4590 | return (rtx_equal_for_thread_p (XEXP (x, 0), XEXP (y, 0), yinsn) |
4591 | && rtx_equal_for_thread_p (XEXP (x, 1), XEXP (y, 1), yinsn)); | |
413c72c2 | 4592 | else if (GET_RTX_CLASS (code) == '1') |
c5ea5f3b | 4593 | return rtx_equal_for_thread_p (XEXP (x, 0), XEXP (y, 0), yinsn); |
413c72c2 | 4594 | |
15a63be1 RK |
4595 | /* Handle special-cases first. */ |
4596 | switch (code) | |
4597 | { | |
4598 | case REG: | |
4599 | if (REGNO (x) == REGNO (y) && ! modified_regs[REGNO (x)]) | |
4600 | return 1; | |
4601 | ||
4602 | /* If neither is user variable or hard register, check for possible | |
4603 | equivalence. */ | |
4604 | if (REG_USERVAR_P (x) || REG_USERVAR_P (y) | |
4605 | || REGNO (x) < FIRST_PSEUDO_REGISTER | |
4606 | || REGNO (y) < FIRST_PSEUDO_REGISTER) | |
4607 | return 0; | |
4608 | ||
4609 | if (same_regs[REGNO (x)] == -1) | |
4610 | { | |
4611 | same_regs[REGNO (x)] = REGNO (y); | |
4612 | num_same_regs++; | |
4613 | ||
4614 | /* If this is the first time we are seeing a register on the `Y' | |
4615 | side, see if it is the last use. If not, we can't thread the | |
4616 | jump, so mark it as not equivalent. */ | |
b1f21e0a | 4617 | if (REGNO_LAST_UID (REGNO (y)) != INSN_UID (yinsn)) |
15a63be1 RK |
4618 | return 0; |
4619 | ||
4620 | return 1; | |
4621 | } | |
4622 | else | |
4623 | return (same_regs[REGNO (x)] == REGNO (y)); | |
4624 | ||
4625 | break; | |
4626 | ||
4627 | case MEM: | |
6dc42e49 | 4628 | /* If memory modified or either volatile, not equivalent. |
0f41302f | 4629 | Else, check address. */ |
15a63be1 RK |
4630 | if (modified_mem || MEM_VOLATILE_P (x) || MEM_VOLATILE_P (y)) |
4631 | return 0; | |
4632 | ||
4633 | return rtx_equal_for_thread_p (XEXP (x, 0), XEXP (y, 0), yinsn); | |
4634 | ||
4635 | case ASM_INPUT: | |
4636 | if (MEM_VOLATILE_P (x) || MEM_VOLATILE_P (y)) | |
4637 | return 0; | |
4638 | ||
4639 | break; | |
4640 | ||
4641 | case SET: | |
4642 | /* Cancel a pending `same_regs' if setting equivalenced registers. | |
4643 | Then process source. */ | |
4644 | if (GET_CODE (SET_DEST (x)) == REG | |
4645 | && GET_CODE (SET_DEST (y)) == REG) | |
4646 | { | |
4647 | if (same_regs[REGNO (SET_DEST (x))] == REGNO (SET_DEST (y))) | |
4648 | { | |
4649 | same_regs[REGNO (SET_DEST (x))] = -1; | |
4650 | num_same_regs--; | |
4651 | } | |
4652 | else if (REGNO (SET_DEST (x)) != REGNO (SET_DEST (y))) | |
4653 | return 0; | |
4654 | } | |
4655 | else | |
4656 | if (rtx_equal_for_thread_p (SET_DEST (x), SET_DEST (y), yinsn) == 0) | |
4657 | return 0; | |
4658 | ||
4659 | return rtx_equal_for_thread_p (SET_SRC (x), SET_SRC (y), yinsn); | |
4660 | ||
4661 | case LABEL_REF: | |
4662 | return XEXP (x, 0) == XEXP (y, 0); | |
4663 | ||
4664 | case SYMBOL_REF: | |
4665 | return XSTR (x, 0) == XSTR (y, 0); | |
e9a25f70 JL |
4666 | |
4667 | default: | |
4668 | break; | |
15a63be1 RK |
4669 | } |
4670 | ||
4671 | if (x == y) | |
4672 | return 1; | |
4673 | ||
4674 | fmt = GET_RTX_FORMAT (code); | |
4675 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
4676 | { | |
4677 | switch (fmt[i]) | |
4678 | { | |
5f4f0e22 CH |
4679 | case 'w': |
4680 | if (XWINT (x, i) != XWINT (y, i)) | |
4681 | return 0; | |
4682 | break; | |
4683 | ||
15a63be1 RK |
4684 | case 'n': |
4685 | case 'i': | |
4686 | if (XINT (x, i) != XINT (y, i)) | |
4687 | return 0; | |
4688 | break; | |
4689 | ||
4690 | case 'V': | |
4691 | case 'E': | |
4692 | /* Two vectors must have the same length. */ | |
4693 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
4694 | return 0; | |
4695 | ||
4696 | /* And the corresponding elements must match. */ | |
4697 | for (j = 0; j < XVECLEN (x, i); j++) | |
4698 | if (rtx_equal_for_thread_p (XVECEXP (x, i, j), | |
4699 | XVECEXP (y, i, j), yinsn) == 0) | |
4700 | return 0; | |
4701 | break; | |
4702 | ||
4703 | case 'e': | |
4704 | if (rtx_equal_for_thread_p (XEXP (x, i), XEXP (y, i), yinsn) == 0) | |
4705 | return 0; | |
4706 | break; | |
4707 | ||
4708 | case 'S': | |
4709 | case 's': | |
4710 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
4711 | return 0; | |
4712 | break; | |
4713 | ||
4714 | case 'u': | |
4715 | /* These are just backpointers, so they don't matter. */ | |
4716 | break; | |
4717 | ||
4718 | case '0': | |
4719 | break; | |
4720 | ||
4721 | /* It is believed that rtx's at this level will never | |
4722 | contain anything but integers and other rtx's, | |
4723 | except for within LABEL_REFs and SYMBOL_REFs. */ | |
4724 | default: | |
4725 | abort (); | |
4726 | } | |
4727 | } | |
4728 | return 1; | |
4729 | } | |
956d6950 JL |
4730 | \f |
4731 | ||
4732 | /* Return the insn that NEW can be safely inserted in front of starting at | |
4733 | the jump insn INSN. Return 0 if it is not safe to do this jump | |
4734 | optimization. Note that NEW must contain a single set. */ | |
4735 | ||
4736 | static rtx | |
4737 | find_insert_position (insn, new) | |
4738 | rtx insn; | |
4739 | rtx new; | |
4740 | { | |
4741 | int i; | |
4742 | rtx prev; | |
4743 | ||
4744 | /* If NEW does not clobber, it is safe to insert NEW before INSN. */ | |
4745 | if (GET_CODE (PATTERN (new)) != PARALLEL) | |
4746 | return insn; | |
4747 | ||
4748 | for (i = XVECLEN (PATTERN (new), 0) - 1; i >= 0; i--) | |
4749 | if (GET_CODE (XVECEXP (PATTERN (new), 0, i)) == CLOBBER | |
4750 | && reg_overlap_mentioned_p (XEXP (XVECEXP (PATTERN (new), 0, i), 0), | |
4751 | insn)) | |
4752 | break; | |
4753 | ||
4754 | if (i < 0) | |
4755 | return insn; | |
4756 | ||
4757 | /* There is a good chance that the previous insn PREV sets the thing | |
4758 | being clobbered (often the CC in a hard reg). If PREV does not | |
4759 | use what NEW sets, we can insert NEW before PREV. */ | |
4760 | ||
4761 | prev = prev_active_insn (insn); | |
4762 | for (i = XVECLEN (PATTERN (new), 0) - 1; i >= 0; i--) | |
4763 | if (GET_CODE (XVECEXP (PATTERN (new), 0, i)) == CLOBBER | |
4764 | && reg_overlap_mentioned_p (XEXP (XVECEXP (PATTERN (new), 0, i), 0), | |
4765 | insn) | |
4766 | && ! modified_in_p (XEXP (XVECEXP (PATTERN (new), 0, i), 0), | |
4767 | prev)) | |
4768 | return 0; | |
4769 | ||
4770 | return reg_mentioned_p (SET_DEST (single_set (new)), prev) ? 0 : prev; | |
4771 | } |