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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" | |
670ee920 | 55 | #include "system.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" |
2e107e9e | 66 | #include "toplev.h" |
15a63be1 RK |
67 | |
68 | /* ??? Eventually must record somehow the labels used by jumps | |
69 | from nested functions. */ | |
70 | /* Pre-record the next or previous real insn for each label? | |
71 | No, this pass is very fast anyway. */ | |
72 | /* Condense consecutive labels? | |
73 | This would make life analysis faster, maybe. */ | |
74 | /* Optimize jump y; x: ... y: jumpif... x? | |
75 | Don't know if it is worth bothering with. */ | |
76 | /* Optimize two cases of conditional jump to conditional jump? | |
77 | This can never delete any instruction or make anything dead, | |
78 | or even change what is live at any point. | |
79 | So perhaps let combiner do it. */ | |
80 | ||
81 | /* Vector indexed by uid. | |
82 | For each CODE_LABEL, index by its uid to get first unconditional jump | |
83 | that jumps to the label. | |
84 | For each JUMP_INSN, index by its uid to get the next unconditional jump | |
85 | that jumps to the same label. | |
86 | Element 0 is the start of a chain of all return insns. | |
87 | (It is safe to use element 0 because insn uid 0 is not used. */ | |
88 | ||
89 | static rtx *jump_chain; | |
90 | ||
91 | /* List of labels referred to from initializers. | |
92 | These can never be deleted. */ | |
93 | rtx forced_labels; | |
94 | ||
95 | /* Maximum index in jump_chain. */ | |
96 | ||
97 | static int max_jump_chain; | |
98 | ||
99 | /* Set nonzero by jump_optimize if control can fall through | |
100 | to the end of the function. */ | |
101 | int can_reach_end; | |
102 | ||
103 | /* Indicates whether death notes are significant in cross jump analysis. | |
104 | Normally they are not significant, because of A and B jump to C, | |
105 | and R dies in A, it must die in B. But this might not be true after | |
106 | stack register conversion, and we must compare death notes in that | |
0f41302f | 107 | case. */ |
15a63be1 RK |
108 | |
109 | static int cross_jump_death_matters = 0; | |
110 | ||
8cd2aff2 RK |
111 | static int duplicate_loop_exit_test PROTO((rtx)); |
112 | static void find_cross_jump PROTO((rtx, rtx, int, rtx *, rtx *)); | |
113 | static void do_cross_jump PROTO((rtx, rtx, rtx)); | |
114 | static int jump_back_p PROTO((rtx, rtx)); | |
115 | static int tension_vector_labels PROTO((rtx, int)); | |
116 | static void mark_jump_label PROTO((rtx, rtx, int)); | |
117 | static void delete_computation PROTO((rtx)); | |
118 | static void delete_from_jump_chain PROTO((rtx)); | |
119 | static int delete_labelref_insn PROTO((rtx, rtx, int)); | |
e009aaf3 | 120 | static void mark_modified_reg PROTO((rtx, rtx)); |
8cd2aff2 | 121 | static void redirect_tablejump PROTO((rtx, rtx)); |
7a87758d | 122 | #ifndef HAVE_cc0 |
956d6950 | 123 | static rtx find_insert_position PROTO((rtx, rtx)); |
7a87758d | 124 | #endif |
15a63be1 RK |
125 | \f |
126 | /* Delete no-op jumps and optimize jumps to jumps | |
127 | and jumps around jumps. | |
128 | Delete unused labels and unreachable code. | |
129 | ||
130 | If CROSS_JUMP is 1, detect matching code | |
131 | before a jump and its destination and unify them. | |
132 | If CROSS_JUMP is 2, do cross-jumping, but pay attention to death notes. | |
133 | ||
134 | If NOOP_MOVES is nonzero, delete no-op move insns. | |
135 | ||
136 | If AFTER_REGSCAN is nonzero, then this jump pass is being run immediately | |
137 | after regscan, and it is safe to use regno_first_uid and regno_last_uid. | |
138 | ||
139 | If `optimize' is zero, don't change any code, | |
140 | just determine whether control drops off the end of the function. | |
141 | This case occurs when we have -W and not -O. | |
142 | It works because `delete_insn' checks the value of `optimize' | |
143 | and refrains from actually deleting when that is 0. */ | |
144 | ||
145 | void | |
146 | jump_optimize (f, cross_jump, noop_moves, after_regscan) | |
147 | rtx f; | |
148 | int cross_jump; | |
149 | int noop_moves; | |
150 | int after_regscan; | |
151 | { | |
484c3924 | 152 | register rtx insn, next, note; |
15a63be1 | 153 | int changed; |
a87ef323 | 154 | int old_max_reg; |
15a63be1 RK |
155 | int first = 1; |
156 | int max_uid = 0; | |
157 | rtx last_insn; | |
158 | ||
159 | cross_jump_death_matters = (cross_jump == 2); | |
160 | ||
484c3924 RK |
161 | /* Initialize LABEL_NUSES and JUMP_LABEL fields. Delete any REG_LABEL |
162 | notes whose labels don't occur in the insn any more. */ | |
15a63be1 RK |
163 | |
164 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
165 | { | |
166 | if (GET_CODE (insn) == CODE_LABEL) | |
167 | LABEL_NUSES (insn) = (LABEL_PRESERVE_P (insn) != 0); | |
168 | else if (GET_CODE (insn) == JUMP_INSN) | |
169 | JUMP_LABEL (insn) = 0; | |
484c3924 RK |
170 | else if (GET_CODE (insn) == INSN || GET_CODE (insn) == CALL_INSN) |
171 | for (note = REG_NOTES (insn); note; note = next) | |
172 | { | |
173 | next = XEXP (note, 1); | |
174 | if (REG_NOTE_KIND (note) == REG_LABEL | |
175 | && ! reg_mentioned_p (XEXP (note, 0), PATTERN (insn))) | |
176 | remove_note (insn, note); | |
177 | } | |
178 | ||
15a63be1 RK |
179 | if (INSN_UID (insn) > max_uid) |
180 | max_uid = INSN_UID (insn); | |
181 | } | |
182 | ||
183 | max_uid++; | |
184 | ||
185 | /* Delete insns following barriers, up to next label. */ | |
186 | ||
187 | for (insn = f; insn;) | |
188 | { | |
189 | if (GET_CODE (insn) == BARRIER) | |
190 | { | |
191 | insn = NEXT_INSN (insn); | |
192 | while (insn != 0 && GET_CODE (insn) != CODE_LABEL) | |
193 | { | |
194 | if (GET_CODE (insn) == NOTE | |
195 | && NOTE_LINE_NUMBER (insn) != NOTE_INSN_FUNCTION_END) | |
196 | insn = NEXT_INSN (insn); | |
197 | else | |
198 | insn = delete_insn (insn); | |
199 | } | |
200 | /* INSN is now the code_label. */ | |
201 | } | |
202 | else | |
203 | insn = NEXT_INSN (insn); | |
204 | } | |
205 | ||
206 | /* Leave some extra room for labels and duplicate exit test insns | |
207 | we make. */ | |
208 | max_jump_chain = max_uid * 14 / 10; | |
209 | jump_chain = (rtx *) alloca (max_jump_chain * sizeof (rtx)); | |
4c9a05bc | 210 | bzero ((char *) jump_chain, max_jump_chain * sizeof (rtx)); |
15a63be1 RK |
211 | |
212 | /* Mark the label each jump jumps to. | |
213 | Combine consecutive labels, and count uses of labels. | |
214 | ||
215 | For each label, make a chain (using `jump_chain') | |
216 | of all the *unconditional* jumps that jump to it; | |
217 | also make a chain of all returns. */ | |
218 | ||
219 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
ac9b3c97 | 220 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') |
15a63be1 RK |
221 | { |
222 | mark_jump_label (PATTERN (insn), insn, cross_jump); | |
ac9b3c97 | 223 | if (! INSN_DELETED_P (insn) && GET_CODE (insn) == JUMP_INSN) |
15a63be1 RK |
224 | { |
225 | if (JUMP_LABEL (insn) != 0 && simplejump_p (insn)) | |
226 | { | |
227 | jump_chain[INSN_UID (insn)] | |
228 | = jump_chain[INSN_UID (JUMP_LABEL (insn))]; | |
229 | jump_chain[INSN_UID (JUMP_LABEL (insn))] = insn; | |
230 | } | |
231 | if (GET_CODE (PATTERN (insn)) == RETURN) | |
232 | { | |
233 | jump_chain[INSN_UID (insn)] = jump_chain[0]; | |
234 | jump_chain[0] = insn; | |
235 | } | |
236 | } | |
237 | } | |
238 | ||
239 | /* Keep track of labels used from static data; | |
240 | they cannot ever be deleted. */ | |
241 | ||
242 | for (insn = forced_labels; insn; insn = XEXP (insn, 1)) | |
243 | LABEL_NUSES (XEXP (insn, 0))++; | |
244 | ||
6adb4e3a MS |
245 | check_exception_handler_labels (); |
246 | ||
247 | /* Keep track of labels used for marking handlers for exception | |
248 | regions; they cannot usually be deleted. */ | |
249 | ||
250 | for (insn = exception_handler_labels; insn; insn = XEXP (insn, 1)) | |
251 | LABEL_NUSES (XEXP (insn, 0))++; | |
252 | ||
253 | exception_optimize (); | |
254 | ||
15a63be1 RK |
255 | /* Delete all labels already not referenced. |
256 | Also find the last insn. */ | |
257 | ||
258 | last_insn = 0; | |
259 | for (insn = f; insn; ) | |
260 | { | |
261 | if (GET_CODE (insn) == CODE_LABEL && LABEL_NUSES (insn) == 0) | |
262 | insn = delete_insn (insn); | |
263 | else | |
264 | { | |
265 | last_insn = insn; | |
266 | insn = NEXT_INSN (insn); | |
267 | } | |
268 | } | |
269 | ||
270 | if (!optimize) | |
271 | { | |
272 | /* See if there is still a NOTE_INSN_FUNCTION_END in this function. | |
273 | If so record that this function can drop off the end. */ | |
274 | ||
275 | insn = last_insn; | |
276 | { | |
277 | int n_labels = 1; | |
278 | while (insn | |
279 | /* One label can follow the end-note: the return label. */ | |
280 | && ((GET_CODE (insn) == CODE_LABEL && n_labels-- > 0) | |
281 | /* Ordinary insns can follow it if returning a structure. */ | |
282 | || GET_CODE (insn) == INSN | |
283 | /* If machine uses explicit RETURN insns, no epilogue, | |
284 | then one of them follows the note. */ | |
285 | || (GET_CODE (insn) == JUMP_INSN | |
286 | && GET_CODE (PATTERN (insn)) == RETURN) | |
60374599 DE |
287 | /* A barrier can follow the return insn. */ |
288 | || GET_CODE (insn) == BARRIER | |
15a63be1 RK |
289 | /* Other kinds of notes can follow also. */ |
290 | || (GET_CODE (insn) == NOTE | |
291 | && NOTE_LINE_NUMBER (insn) != NOTE_INSN_FUNCTION_END))) | |
292 | insn = PREV_INSN (insn); | |
293 | } | |
294 | ||
295 | /* Report if control can fall through at the end of the function. */ | |
296 | if (insn && GET_CODE (insn) == NOTE | |
297 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_END | |
298 | && ! INSN_DELETED_P (insn)) | |
299 | can_reach_end = 1; | |
300 | ||
301 | /* Zero the "deleted" flag of all the "deleted" insns. */ | |
302 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
303 | INSN_DELETED_P (insn) = 0; | |
81fc4f5c JL |
304 | |
305 | /* Show that the jump chain is not valid. */ | |
306 | jump_chain = 0; | |
15a63be1 RK |
307 | return; |
308 | } | |
309 | ||
310 | #ifdef HAVE_return | |
311 | if (HAVE_return) | |
312 | { | |
313 | /* If we fall through to the epilogue, see if we can insert a RETURN insn | |
314 | in front of it. If the machine allows it at this point (we might be | |
315 | after reload for a leaf routine), it will improve optimization for it | |
316 | to be there. */ | |
317 | insn = get_last_insn (); | |
318 | while (insn && GET_CODE (insn) == NOTE) | |
319 | insn = PREV_INSN (insn); | |
320 | ||
321 | if (insn && GET_CODE (insn) != BARRIER) | |
322 | { | |
323 | emit_jump_insn (gen_return ()); | |
324 | emit_barrier (); | |
325 | } | |
326 | } | |
327 | #endif | |
328 | ||
329 | if (noop_moves) | |
330 | for (insn = f; insn; ) | |
331 | { | |
2156dfe3 | 332 | next = NEXT_INSN (insn); |
15a63be1 RK |
333 | |
334 | if (GET_CODE (insn) == INSN) | |
335 | { | |
336 | register rtx body = PATTERN (insn); | |
337 | ||
338 | /* Combine stack_adjusts with following push_insns. */ | |
339 | #ifdef PUSH_ROUNDING | |
340 | if (GET_CODE (body) == SET | |
341 | && SET_DEST (body) == stack_pointer_rtx | |
342 | && GET_CODE (SET_SRC (body)) == PLUS | |
343 | && XEXP (SET_SRC (body), 0) == stack_pointer_rtx | |
344 | && GET_CODE (XEXP (SET_SRC (body), 1)) == CONST_INT | |
345 | && INTVAL (XEXP (SET_SRC (body), 1)) > 0) | |
346 | { | |
347 | rtx p; | |
348 | rtx stack_adjust_insn = insn; | |
349 | int stack_adjust_amount = INTVAL (XEXP (SET_SRC (body), 1)); | |
350 | int total_pushed = 0; | |
351 | int pushes = 0; | |
352 | ||
353 | /* Find all successive push insns. */ | |
354 | p = insn; | |
355 | /* Don't convert more than three pushes; | |
356 | that starts adding too many displaced addresses | |
357 | and the whole thing starts becoming a losing | |
358 | proposition. */ | |
359 | while (pushes < 3) | |
360 | { | |
361 | rtx pbody, dest; | |
362 | p = next_nonnote_insn (p); | |
363 | if (p == 0 || GET_CODE (p) != INSN) | |
364 | break; | |
365 | pbody = PATTERN (p); | |
366 | if (GET_CODE (pbody) != SET) | |
367 | break; | |
368 | dest = SET_DEST (pbody); | |
369 | /* Allow a no-op move between the adjust and the push. */ | |
370 | if (GET_CODE (dest) == REG | |
371 | && GET_CODE (SET_SRC (pbody)) == REG | |
372 | && REGNO (dest) == REGNO (SET_SRC (pbody))) | |
373 | continue; | |
374 | if (! (GET_CODE (dest) == MEM | |
375 | && GET_CODE (XEXP (dest, 0)) == POST_INC | |
376 | && XEXP (XEXP (dest, 0), 0) == stack_pointer_rtx)) | |
377 | break; | |
378 | pushes++; | |
1ad4c71a | 379 | if (total_pushed + GET_MODE_SIZE (GET_MODE (SET_DEST (pbody))) |
15a63be1 RK |
380 | > stack_adjust_amount) |
381 | break; | |
1ad4c71a | 382 | total_pushed += GET_MODE_SIZE (GET_MODE (SET_DEST (pbody))); |
15a63be1 RK |
383 | } |
384 | ||
385 | /* Discard the amount pushed from the stack adjust; | |
386 | maybe eliminate it entirely. */ | |
387 | if (total_pushed >= stack_adjust_amount) | |
388 | { | |
344a8220 | 389 | delete_computation (stack_adjust_insn); |
15a63be1 RK |
390 | total_pushed = stack_adjust_amount; |
391 | } | |
392 | else | |
393 | XEXP (SET_SRC (PATTERN (stack_adjust_insn)), 1) | |
5f4f0e22 | 394 | = GEN_INT (stack_adjust_amount - total_pushed); |
15a63be1 RK |
395 | |
396 | /* Change the appropriate push insns to ordinary stores. */ | |
397 | p = insn; | |
398 | while (total_pushed > 0) | |
399 | { | |
400 | rtx pbody, dest; | |
401 | p = next_nonnote_insn (p); | |
402 | if (GET_CODE (p) != INSN) | |
403 | break; | |
404 | pbody = PATTERN (p); | |
689fcba8 | 405 | if (GET_CODE (pbody) != SET) |
15a63be1 RK |
406 | break; |
407 | dest = SET_DEST (pbody); | |
689fcba8 DM |
408 | /* Allow a no-op move between the adjust and the push. */ |
409 | if (GET_CODE (dest) == REG | |
410 | && GET_CODE (SET_SRC (pbody)) == REG | |
411 | && REGNO (dest) == REGNO (SET_SRC (pbody))) | |
412 | continue; | |
15a63be1 RK |
413 | if (! (GET_CODE (dest) == MEM |
414 | && GET_CODE (XEXP (dest, 0)) == POST_INC | |
415 | && XEXP (XEXP (dest, 0), 0) == stack_pointer_rtx)) | |
416 | break; | |
1ad4c71a | 417 | total_pushed -= GET_MODE_SIZE (GET_MODE (SET_DEST (pbody))); |
15a63be1 RK |
418 | /* If this push doesn't fully fit in the space |
419 | of the stack adjust that we deleted, | |
420 | make another stack adjust here for what we | |
421 | didn't use up. There should be peepholes | |
422 | to recognize the resulting sequence of insns. */ | |
423 | if (total_pushed < 0) | |
424 | { | |
425 | emit_insn_before (gen_add2_insn (stack_pointer_rtx, | |
5f4f0e22 | 426 | GEN_INT (- total_pushed)), |
15a63be1 RK |
427 | p); |
428 | break; | |
429 | } | |
430 | XEXP (dest, 0) | |
431 | = plus_constant (stack_pointer_rtx, total_pushed); | |
432 | } | |
433 | } | |
434 | #endif | |
435 | ||
436 | /* Detect and delete no-op move instructions | |
437 | resulting from not allocating a parameter in a register. */ | |
438 | ||
439 | if (GET_CODE (body) == SET | |
440 | && (SET_DEST (body) == SET_SRC (body) | |
441 | || (GET_CODE (SET_DEST (body)) == MEM | |
442 | && GET_CODE (SET_SRC (body)) == MEM | |
443 | && rtx_equal_p (SET_SRC (body), SET_DEST (body)))) | |
444 | && ! (GET_CODE (SET_DEST (body)) == MEM | |
445 | && MEM_VOLATILE_P (SET_DEST (body))) | |
446 | && ! (GET_CODE (SET_SRC (body)) == MEM | |
447 | && MEM_VOLATILE_P (SET_SRC (body)))) | |
344a8220 | 448 | delete_computation (insn); |
15a63be1 RK |
449 | |
450 | /* Detect and ignore no-op move instructions | |
451 | resulting from smart or fortuitous register allocation. */ | |
452 | ||
453 | else if (GET_CODE (body) == SET) | |
454 | { | |
455 | int sreg = true_regnum (SET_SRC (body)); | |
456 | int dreg = true_regnum (SET_DEST (body)); | |
457 | ||
458 | if (sreg == dreg && sreg >= 0) | |
459 | delete_insn (insn); | |
460 | else if (sreg >= 0 && dreg >= 0) | |
461 | { | |
462 | rtx trial; | |
5f4f0e22 CH |
463 | rtx tem = find_equiv_reg (NULL_RTX, insn, 0, |
464 | sreg, NULL_PTR, dreg, | |
15a63be1 RK |
465 | GET_MODE (SET_SRC (body))); |
466 | ||
db3cf6fb MS |
467 | if (tem != 0 |
468 | && GET_MODE (tem) == GET_MODE (SET_DEST (body))) | |
15a63be1 RK |
469 | { |
470 | /* DREG may have been the target of a REG_DEAD note in | |
471 | the insn which makes INSN redundant. If so, reorg | |
472 | would still think it is dead. So search for such a | |
473 | note and delete it if we find it. */ | |
59df2b2b RK |
474 | if (! find_regno_note (insn, REG_UNUSED, dreg)) |
475 | for (trial = prev_nonnote_insn (insn); | |
476 | trial && GET_CODE (trial) != CODE_LABEL; | |
477 | trial = prev_nonnote_insn (trial)) | |
478 | if (find_regno_note (trial, REG_DEAD, dreg)) | |
479 | { | |
480 | remove_death (dreg, trial); | |
481 | break; | |
482 | } | |
483 | #ifdef PRESERVE_DEATH_INFO_REGNO_P | |
484 | /* Deleting insn could lose a death-note for SREG | |
485 | so don't do it if final needs accurate | |
486 | death-notes. */ | |
487 | if (PRESERVE_DEATH_INFO_REGNO_P (sreg) | |
488 | && (trial = find_regno_note (insn, REG_DEAD, sreg))) | |
489 | { | |
490 | /* Change this into a USE so that we won't emit | |
491 | code for it, but still can keep the note. */ | |
492 | PATTERN (insn) | |
38a448ca | 493 | = gen_rtx_USE (VOIDmode, XEXP (trial, 0)); |
d8db8192 | 494 | INSN_CODE (insn) = -1; |
59df2b2b RK |
495 | /* Remove all reg notes but the REG_DEAD one. */ |
496 | REG_NOTES (insn) = trial; | |
497 | XEXP (trial, 1) = NULL_RTX; | |
498 | } | |
499 | else | |
500 | #endif | |
15a63be1 RK |
501 | delete_insn (insn); |
502 | } | |
503 | } | |
504 | else if (dreg >= 0 && CONSTANT_P (SET_SRC (body)) | |
5f4f0e22 CH |
505 | && find_equiv_reg (SET_SRC (body), insn, 0, dreg, |
506 | NULL_PTR, 0, | |
507 | GET_MODE (SET_DEST (body)))) | |
15a63be1 RK |
508 | { |
509 | /* This handles the case where we have two consecutive | |
510 | assignments of the same constant to pseudos that didn't | |
511 | get a hard reg. Each SET from the constant will be | |
512 | converted into a SET of the spill register and an | |
513 | output reload will be made following it. This produces | |
514 | two loads of the same constant into the same spill | |
515 | register. */ | |
516 | ||
517 | rtx in_insn = insn; | |
518 | ||
519 | /* Look back for a death note for the first reg. | |
520 | If there is one, it is no longer accurate. */ | |
521 | while (in_insn && GET_CODE (in_insn) != CODE_LABEL) | |
522 | { | |
523 | if ((GET_CODE (in_insn) == INSN | |
524 | || GET_CODE (in_insn) == JUMP_INSN) | |
525 | && find_regno_note (in_insn, REG_DEAD, dreg)) | |
526 | { | |
527 | remove_death (dreg, in_insn); | |
528 | break; | |
529 | } | |
530 | in_insn = PREV_INSN (in_insn); | |
531 | } | |
532 | ||
533 | /* Delete the second load of the value. */ | |
534 | delete_insn (insn); | |
535 | } | |
536 | } | |
537 | else if (GET_CODE (body) == PARALLEL) | |
538 | { | |
539 | /* If each part is a set between two identical registers or | |
0f41302f | 540 | a USE or CLOBBER, delete the insn. */ |
15a63be1 RK |
541 | int i, sreg, dreg; |
542 | rtx tem; | |
543 | ||
544 | for (i = XVECLEN (body, 0) - 1; i >= 0; i--) | |
545 | { | |
546 | tem = XVECEXP (body, 0, i); | |
547 | if (GET_CODE (tem) == USE || GET_CODE (tem) == CLOBBER) | |
548 | continue; | |
549 | ||
550 | if (GET_CODE (tem) != SET | |
551 | || (sreg = true_regnum (SET_SRC (tem))) < 0 | |
552 | || (dreg = true_regnum (SET_DEST (tem))) < 0 | |
553 | || dreg != sreg) | |
554 | break; | |
555 | } | |
556 | ||
557 | if (i < 0) | |
558 | delete_insn (insn); | |
559 | } | |
15a63be1 | 560 | /* Also delete insns to store bit fields if they are no-ops. */ |
f76b9db2 ILT |
561 | /* Not worth the hair to detect this in the big-endian case. */ |
562 | else if (! BYTES_BIG_ENDIAN | |
563 | && GET_CODE (body) == SET | |
15a63be1 RK |
564 | && GET_CODE (SET_DEST (body)) == ZERO_EXTRACT |
565 | && XEXP (SET_DEST (body), 2) == const0_rtx | |
566 | && XEXP (SET_DEST (body), 0) == SET_SRC (body) | |
567 | && ! (GET_CODE (SET_SRC (body)) == MEM | |
568 | && MEM_VOLATILE_P (SET_SRC (body)))) | |
569 | delete_insn (insn); | |
15a63be1 RK |
570 | } |
571 | insn = next; | |
572 | } | |
573 | ||
2156dfe3 RK |
574 | /* If we haven't yet gotten to reload and we have just run regscan, |
575 | delete any insn that sets a register that isn't used elsewhere. | |
576 | This helps some of the optimizations below by having less insns | |
577 | being jumped around. */ | |
578 | ||
579 | if (! reload_completed && after_regscan) | |
580 | for (insn = f; insn; insn = next) | |
581 | { | |
582 | rtx set = single_set (insn); | |
583 | ||
584 | next = NEXT_INSN (insn); | |
585 | ||
586 | if (set && GET_CODE (SET_DEST (set)) == REG | |
587 | && REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER | |
b1f21e0a | 588 | && REGNO_FIRST_UID (REGNO (SET_DEST (set))) == INSN_UID (insn) |
b803fb99 RS |
589 | /* We use regno_last_note_uid so as not to delete the setting |
590 | of a reg that's used in notes. A subsequent optimization | |
591 | might arrange to use that reg for real. */ | |
b1f21e0a | 592 | && REGNO_LAST_NOTE_UID (REGNO (SET_DEST (set))) == INSN_UID (insn) |
d008e26c RK |
593 | && ! side_effects_p (SET_SRC (set)) |
594 | && ! find_reg_note (insn, REG_RETVAL, 0)) | |
2156dfe3 RK |
595 | delete_insn (insn); |
596 | } | |
597 | ||
15a63be1 RK |
598 | /* Now iterate optimizing jumps until nothing changes over one pass. */ |
599 | changed = 1; | |
a87ef323 | 600 | old_max_reg = max_reg_num (); |
15a63be1 RK |
601 | while (changed) |
602 | { | |
15a63be1 RK |
603 | changed = 0; |
604 | ||
605 | for (insn = f; insn; insn = next) | |
606 | { | |
607 | rtx reallabelprev; | |
2156dfe3 | 608 | rtx temp, temp1, temp2, temp3, temp4, temp5, temp6; |
15a63be1 | 609 | rtx nlabel; |
c16ddde3 | 610 | int this_is_simplejump, this_is_condjump, reversep = 0; |
3480bb98 | 611 | int this_is_condjump_in_parallel; |
a87ef323 | 612 | |
15a63be1 RK |
613 | #if 0 |
614 | /* If NOT the first iteration, if this is the last jump pass | |
615 | (just before final), do the special peephole optimizations. | |
616 | Avoiding the first iteration gives ordinary jump opts | |
617 | a chance to work before peephole opts. */ | |
618 | ||
619 | if (reload_completed && !first && !flag_no_peephole) | |
620 | if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN) | |
621 | peephole (insn); | |
622 | #endif | |
623 | ||
624 | /* That could have deleted some insns after INSN, so check now | |
625 | what the following insn is. */ | |
626 | ||
627 | next = NEXT_INSN (insn); | |
628 | ||
629 | /* See if this is a NOTE_INSN_LOOP_BEG followed by an unconditional | |
630 | jump. Try to optimize by duplicating the loop exit test if so. | |
631 | This is only safe immediately after regscan, because it uses | |
632 | the values of regno_first_uid and regno_last_uid. */ | |
633 | if (after_regscan && GET_CODE (insn) == NOTE | |
634 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG | |
635 | && (temp1 = next_nonnote_insn (insn)) != 0 | |
636 | && simplejump_p (temp1)) | |
637 | { | |
638 | temp = PREV_INSN (insn); | |
639 | if (duplicate_loop_exit_test (insn)) | |
640 | { | |
641 | changed = 1; | |
642 | next = NEXT_INSN (temp); | |
643 | continue; | |
644 | } | |
645 | } | |
646 | ||
647 | if (GET_CODE (insn) != JUMP_INSN) | |
648 | continue; | |
649 | ||
650 | this_is_simplejump = simplejump_p (insn); | |
651 | this_is_condjump = condjump_p (insn); | |
3480bb98 | 652 | this_is_condjump_in_parallel = condjump_in_parallel_p (insn); |
15a63be1 RK |
653 | |
654 | /* Tension the labels in dispatch tables. */ | |
655 | ||
656 | if (GET_CODE (PATTERN (insn)) == ADDR_VEC) | |
657 | changed |= tension_vector_labels (PATTERN (insn), 0); | |
658 | if (GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC) | |
659 | changed |= tension_vector_labels (PATTERN (insn), 1); | |
660 | ||
661 | /* If a dispatch table always goes to the same place, | |
662 | get rid of it and replace the insn that uses it. */ | |
663 | ||
664 | if (GET_CODE (PATTERN (insn)) == ADDR_VEC | |
665 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC) | |
666 | { | |
667 | int i; | |
668 | rtx pat = PATTERN (insn); | |
669 | int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC; | |
670 | int len = XVECLEN (pat, diff_vec_p); | |
671 | rtx dispatch = prev_real_insn (insn); | |
672 | ||
673 | for (i = 0; i < len; i++) | |
674 | if (XEXP (XVECEXP (pat, diff_vec_p, i), 0) | |
675 | != XEXP (XVECEXP (pat, diff_vec_p, 0), 0)) | |
676 | break; | |
677 | if (i == len | |
0546e268 | 678 | && dispatch != 0 |
15a63be1 RK |
679 | && GET_CODE (dispatch) == JUMP_INSN |
680 | && JUMP_LABEL (dispatch) != 0 | |
681 | /* Don't mess with a casesi insn. */ | |
682 | && !(GET_CODE (PATTERN (dispatch)) == SET | |
683 | && (GET_CODE (SET_SRC (PATTERN (dispatch))) | |
684 | == IF_THEN_ELSE)) | |
685 | && next_real_insn (JUMP_LABEL (dispatch)) == insn) | |
686 | { | |
687 | redirect_tablejump (dispatch, | |
688 | XEXP (XVECEXP (pat, diff_vec_p, 0), 0)); | |
689 | changed = 1; | |
690 | } | |
691 | } | |
692 | ||
693 | reallabelprev = prev_active_insn (JUMP_LABEL (insn)); | |
694 | ||
695 | /* If a jump references the end of the function, try to turn | |
696 | it into a RETURN insn, possibly a conditional one. */ | |
697 | if (JUMP_LABEL (insn) | |
8e318904 JL |
698 | && (next_active_insn (JUMP_LABEL (insn)) == 0 |
699 | || GET_CODE (PATTERN (next_active_insn (JUMP_LABEL (insn)))) | |
700 | == RETURN)) | |
5f4f0e22 | 701 | changed |= redirect_jump (insn, NULL_RTX); |
15a63be1 RK |
702 | |
703 | /* Detect jump to following insn. */ | |
704 | if (reallabelprev == insn && condjump_p (insn)) | |
705 | { | |
cd423ead | 706 | next = next_real_insn (JUMP_LABEL (insn)); |
15a63be1 RK |
707 | delete_jump (insn); |
708 | changed = 1; | |
709 | continue; | |
710 | } | |
711 | ||
d45cf215 | 712 | /* If we have an unconditional jump preceded by a USE, try to put |
15a63be1 RK |
713 | the USE before the target and jump there. This simplifies many |
714 | of the optimizations below since we don't have to worry about | |
715 | dealing with these USE insns. We only do this if the label | |
716 | being branch to already has the identical USE or if code | |
717 | never falls through to that label. */ | |
718 | ||
719 | if (this_is_simplejump | |
720 | && (temp = prev_nonnote_insn (insn)) != 0 | |
721 | && GET_CODE (temp) == INSN && GET_CODE (PATTERN (temp)) == USE | |
722 | && (temp1 = prev_nonnote_insn (JUMP_LABEL (insn))) != 0 | |
723 | && (GET_CODE (temp1) == BARRIER | |
724 | || (GET_CODE (temp1) == INSN | |
9740123d JW |
725 | && rtx_equal_p (PATTERN (temp), PATTERN (temp1)))) |
726 | /* Don't do this optimization if we have a loop containing only | |
727 | the USE instruction, and the loop start label has a usage | |
728 | count of 1. This is because we will redo this optimization | |
729 | everytime through the outer loop, and jump opt will never | |
730 | exit. */ | |
731 | && ! ((temp2 = prev_nonnote_insn (temp)) != 0 | |
732 | && temp2 == JUMP_LABEL (insn) | |
733 | && LABEL_NUSES (temp2) == 1)) | |
15a63be1 RK |
734 | { |
735 | if (GET_CODE (temp1) == BARRIER) | |
736 | { | |
2156dfe3 | 737 | emit_insn_after (PATTERN (temp), temp1); |
15a63be1 RK |
738 | temp1 = NEXT_INSN (temp1); |
739 | } | |
15a63be1 | 740 | |
2156dfe3 | 741 | delete_insn (temp); |
15a63be1 RK |
742 | redirect_jump (insn, get_label_before (temp1)); |
743 | reallabelprev = prev_real_insn (temp1); | |
744 | changed = 1; | |
745 | } | |
746 | ||
747 | /* Simplify if (...) x = a; else x = b; by converting it | |
748 | to x = b; if (...) x = a; | |
749 | if B is sufficiently simple, the test doesn't involve X, | |
750 | and nothing in the test modifies B or X. | |
751 | ||
752 | If we have small register classes, we also can't do this if X | |
753 | is a hard register. | |
754 | ||
755 | If the "x = b;" insn has any REG_NOTES, we don't do this because | |
756 | of the possibility that we are running after CSE and there is a | |
757 | REG_EQUAL note that is only valid if the branch has already been | |
758 | taken. If we move the insn with the REG_EQUAL note, we may | |
759 | fold the comparison to always be false in a later CSE pass. | |
760 | (We could also delete the REG_NOTES when moving the insn, but it | |
761 | seems simpler to not move it.) An exception is that we can move | |
762 | the insn if the only note is a REG_EQUAL or REG_EQUIV whose | |
763 | value is the same as "b". | |
764 | ||
765 | INSN is the branch over the `else' part. | |
766 | ||
767 | We set: | |
768 | ||
d45cf215 | 769 | TEMP to the jump insn preceding "x = a;" |
15a63be1 RK |
770 | TEMP1 to X |
771 | TEMP2 to the insn that sets "x = b;" | |
2156dfe3 RK |
772 | TEMP3 to the insn that sets "x = a;" |
773 | TEMP4 to the set of "x = b"; */ | |
15a63be1 RK |
774 | |
775 | if (this_is_simplejump | |
776 | && (temp3 = prev_active_insn (insn)) != 0 | |
777 | && GET_CODE (temp3) == INSN | |
2156dfe3 RK |
778 | && (temp4 = single_set (temp3)) != 0 |
779 | && GET_CODE (temp1 = SET_DEST (temp4)) == REG | |
f95182a4 ILT |
780 | && (! SMALL_REGISTER_CLASSES |
781 | || REGNO (temp1) >= FIRST_PSEUDO_REGISTER) | |
15a63be1 RK |
782 | && (temp2 = next_active_insn (insn)) != 0 |
783 | && GET_CODE (temp2) == INSN | |
2156dfe3 RK |
784 | && (temp4 = single_set (temp2)) != 0 |
785 | && rtx_equal_p (SET_DEST (temp4), temp1) | |
0bef9b8d RH |
786 | && ! side_effects_p (SET_SRC (temp4)) |
787 | && ! may_trap_p (SET_SRC (temp4)) | |
15a63be1 RK |
788 | && (REG_NOTES (temp2) == 0 |
789 | || ((REG_NOTE_KIND (REG_NOTES (temp2)) == REG_EQUAL | |
790 | || REG_NOTE_KIND (REG_NOTES (temp2)) == REG_EQUIV) | |
791 | && XEXP (REG_NOTES (temp2), 1) == 0 | |
792 | && rtx_equal_p (XEXP (REG_NOTES (temp2), 0), | |
2156dfe3 | 793 | SET_SRC (temp4)))) |
15a63be1 RK |
794 | && (temp = prev_active_insn (temp3)) != 0 |
795 | && condjump_p (temp) && ! simplejump_p (temp) | |
796 | /* TEMP must skip over the "x = a;" insn */ | |
797 | && prev_real_insn (JUMP_LABEL (temp)) == insn | |
798 | && no_labels_between_p (insn, JUMP_LABEL (temp)) | |
799 | /* There must be no other entries to the "x = b;" insn. */ | |
800 | && no_labels_between_p (JUMP_LABEL (temp), temp2) | |
801 | /* INSN must either branch to the insn after TEMP2 or the insn | |
802 | after TEMP2 must branch to the same place as INSN. */ | |
803 | && (reallabelprev == temp2 | |
2156dfe3 RK |
804 | || ((temp5 = next_active_insn (temp2)) != 0 |
805 | && simplejump_p (temp5) | |
806 | && JUMP_LABEL (temp5) == JUMP_LABEL (insn)))) | |
15a63be1 RK |
807 | { |
808 | /* The test expression, X, may be a complicated test with | |
809 | multiple branches. See if we can find all the uses of | |
810 | the label that TEMP branches to without hitting a CALL_INSN | |
811 | or a jump to somewhere else. */ | |
812 | rtx target = JUMP_LABEL (temp); | |
813 | int nuses = LABEL_NUSES (target); | |
51723711 KG |
814 | rtx p; |
815 | #ifdef HAVE_cc0 | |
816 | rtx q; | |
817 | #endif | |
15a63be1 RK |
818 | |
819 | /* Set P to the first jump insn that goes around "x = a;". */ | |
820 | for (p = temp; nuses && p; p = prev_nonnote_insn (p)) | |
821 | { | |
822 | if (GET_CODE (p) == JUMP_INSN) | |
823 | { | |
824 | if (condjump_p (p) && ! simplejump_p (p) | |
825 | && JUMP_LABEL (p) == target) | |
826 | { | |
827 | nuses--; | |
828 | if (nuses == 0) | |
829 | break; | |
830 | } | |
831 | else | |
832 | break; | |
833 | } | |
834 | else if (GET_CODE (p) == CALL_INSN) | |
835 | break; | |
836 | } | |
837 | ||
838 | #ifdef HAVE_cc0 | |
839 | /* We cannot insert anything between a set of cc and its use | |
840 | so if P uses cc0, we must back up to the previous insn. */ | |
841 | q = prev_nonnote_insn (p); | |
842 | if (q && GET_RTX_CLASS (GET_CODE (q)) == 'i' | |
843 | && sets_cc0_p (PATTERN (q))) | |
844 | p = q; | |
845 | #endif | |
846 | ||
847 | if (p) | |
848 | p = PREV_INSN (p); | |
849 | ||
850 | /* If we found all the uses and there was no data conflict, we | |
851 | can move the assignment unless we can branch into the middle | |
852 | from somewhere. */ | |
853 | if (nuses == 0 && p | |
854 | && no_labels_between_p (p, insn) | |
855 | && ! reg_referenced_between_p (temp1, p, NEXT_INSN (temp3)) | |
856 | && ! reg_set_between_p (temp1, p, temp3) | |
2156dfe3 | 857 | && (GET_CODE (SET_SRC (temp4)) == CONST_INT |
8127f74f JW |
858 | || ! modified_between_p (SET_SRC (temp4), p, temp2)) |
859 | /* Verify that registers used by the jump are not clobbered | |
860 | by the instruction being moved. */ | |
861 | && ! modified_between_p (PATTERN (temp), temp2, | |
862 | NEXT_INSN (temp2))) | |
15a63be1 | 863 | { |
2156dfe3 RK |
864 | emit_insn_after_with_line_notes (PATTERN (temp2), p, temp2); |
865 | delete_insn (temp2); | |
15a63be1 RK |
866 | |
867 | /* Set NEXT to an insn that we know won't go away. */ | |
868 | next = next_active_insn (insn); | |
869 | ||
870 | /* Delete the jump around the set. Note that we must do | |
871 | this before we redirect the test jumps so that it won't | |
872 | delete the code immediately following the assignment | |
873 | we moved (which might be a jump). */ | |
874 | ||
875 | delete_insn (insn); | |
876 | ||
877 | /* We either have two consecutive labels or a jump to | |
878 | a jump, so adjust all the JUMP_INSNs to branch to where | |
879 | INSN branches to. */ | |
880 | for (p = NEXT_INSN (p); p != next; p = NEXT_INSN (p)) | |
881 | if (GET_CODE (p) == JUMP_INSN) | |
882 | redirect_jump (p, target); | |
883 | ||
884 | changed = 1; | |
885 | continue; | |
886 | } | |
887 | } | |
888 | ||
66bd9361 JW |
889 | /* Simplify if (...) { x = a; goto l; } x = b; by converting it |
890 | to x = a; if (...) goto l; x = b; | |
891 | if A is sufficiently simple, the test doesn't involve X, | |
892 | and nothing in the test modifies A or X. | |
893 | ||
894 | If we have small register classes, we also can't do this if X | |
895 | is a hard register. | |
896 | ||
897 | If the "x = a;" insn has any REG_NOTES, we don't do this because | |
898 | of the possibility that we are running after CSE and there is a | |
899 | REG_EQUAL note that is only valid if the branch has already been | |
900 | taken. If we move the insn with the REG_EQUAL note, we may | |
901 | fold the comparison to always be false in a later CSE pass. | |
902 | (We could also delete the REG_NOTES when moving the insn, but it | |
903 | seems simpler to not move it.) An exception is that we can move | |
904 | the insn if the only note is a REG_EQUAL or REG_EQUIV whose | |
905 | value is the same as "a". | |
906 | ||
907 | INSN is the goto. | |
908 | ||
909 | We set: | |
910 | ||
911 | TEMP to the jump insn preceding "x = a;" | |
912 | TEMP1 to X | |
913 | TEMP2 to the insn that sets "x = b;" | |
914 | TEMP3 to the insn that sets "x = a;" | |
915 | TEMP4 to the set of "x = a"; */ | |
916 | ||
917 | if (this_is_simplejump | |
918 | && (temp2 = next_active_insn (insn)) != 0 | |
919 | && GET_CODE (temp2) == INSN | |
920 | && (temp4 = single_set (temp2)) != 0 | |
921 | && GET_CODE (temp1 = SET_DEST (temp4)) == REG | |
f95182a4 ILT |
922 | && (! SMALL_REGISTER_CLASSES |
923 | || REGNO (temp1) >= FIRST_PSEUDO_REGISTER) | |
66bd9361 JW |
924 | && (temp3 = prev_active_insn (insn)) != 0 |
925 | && GET_CODE (temp3) == INSN | |
926 | && (temp4 = single_set (temp3)) != 0 | |
927 | && rtx_equal_p (SET_DEST (temp4), temp1) | |
0bef9b8d RH |
928 | && ! side_effects_p (SET_SRC (temp4)) |
929 | && ! may_trap_p (SET_SRC (temp4)) | |
66bd9361 JW |
930 | && (REG_NOTES (temp3) == 0 |
931 | || ((REG_NOTE_KIND (REG_NOTES (temp3)) == REG_EQUAL | |
932 | || REG_NOTE_KIND (REG_NOTES (temp3)) == REG_EQUIV) | |
933 | && XEXP (REG_NOTES (temp3), 1) == 0 | |
934 | && rtx_equal_p (XEXP (REG_NOTES (temp3), 0), | |
935 | SET_SRC (temp4)))) | |
936 | && (temp = prev_active_insn (temp3)) != 0 | |
937 | && condjump_p (temp) && ! simplejump_p (temp) | |
938 | /* TEMP must skip over the "x = a;" insn */ | |
939 | && prev_real_insn (JUMP_LABEL (temp)) == insn | |
940 | && no_labels_between_p (temp, insn)) | |
941 | { | |
942 | rtx prev_label = JUMP_LABEL (temp); | |
943 | rtx insert_after = prev_nonnote_insn (temp); | |
944 | ||
945 | #ifdef HAVE_cc0 | |
946 | /* We cannot insert anything between a set of cc and its use. */ | |
947 | if (insert_after && GET_RTX_CLASS (GET_CODE (insert_after)) == 'i' | |
948 | && sets_cc0_p (PATTERN (insert_after))) | |
949 | insert_after = prev_nonnote_insn (insert_after); | |
950 | #endif | |
951 | ++LABEL_NUSES (prev_label); | |
952 | ||
953 | if (insert_after | |
954 | && no_labels_between_p (insert_after, temp) | |
7a7233ff | 955 | && ! reg_referenced_between_p (temp1, insert_after, temp3) |
04bd0246 DE |
956 | && ! reg_referenced_between_p (temp1, temp3, |
957 | NEXT_INSN (temp2)) | |
66bd9361 | 958 | && ! reg_set_between_p (temp1, insert_after, temp) |
0bef9b8d | 959 | && ! modified_between_p (SET_SRC (temp4), insert_after, temp) |
8127f74f JW |
960 | /* Verify that registers used by the jump are not clobbered |
961 | by the instruction being moved. */ | |
962 | && ! modified_between_p (PATTERN (temp), temp3, | |
963 | NEXT_INSN (temp3)) | |
66bd9361 JW |
964 | && invert_jump (temp, JUMP_LABEL (insn))) |
965 | { | |
966 | emit_insn_after_with_line_notes (PATTERN (temp3), | |
967 | insert_after, temp3); | |
968 | delete_insn (temp3); | |
969 | delete_insn (insn); | |
970 | /* Set NEXT to an insn that we know won't go away. */ | |
971 | next = temp2; | |
972 | changed = 1; | |
973 | } | |
974 | if (prev_label && --LABEL_NUSES (prev_label) == 0) | |
975 | delete_insn (prev_label); | |
976 | if (changed) | |
977 | continue; | |
978 | } | |
979 | ||
2156dfe3 RK |
980 | #ifndef HAVE_cc0 |
981 | /* If we have if (...) x = exp; and branches are expensive, | |
982 | EXP is a single insn, does not have any side effects, cannot | |
983 | trap, and is not too costly, convert this to | |
984 | t = exp; if (...) x = t; | |
985 | ||
986 | Don't do this when we have CC0 because it is unlikely to help | |
987 | and we'd need to worry about where to place the new insn and | |
988 | the potential for conflicts. We also can't do this when we have | |
989 | notes on the insn for the same reason as above. | |
990 | ||
991 | We set: | |
992 | ||
993 | TEMP to the "x = exp;" insn. | |
f903b91f | 994 | TEMP1 to the single set in the "x = exp;" insn. |
2156dfe3 RK |
995 | TEMP2 to "x". */ |
996 | ||
997 | if (! reload_completed | |
998 | && this_is_condjump && ! this_is_simplejump | |
999 | && BRANCH_COST >= 3 | |
1000 | && (temp = next_nonnote_insn (insn)) != 0 | |
a8fc41af | 1001 | && GET_CODE (temp) == INSN |
2156dfe3 RK |
1002 | && REG_NOTES (temp) == 0 |
1003 | && (reallabelprev == temp | |
1004 | || ((temp2 = next_active_insn (temp)) != 0 | |
1005 | && simplejump_p (temp2) | |
1006 | && JUMP_LABEL (temp2) == JUMP_LABEL (insn))) | |
1007 | && (temp1 = single_set (temp)) != 0 | |
1008 | && (temp2 = SET_DEST (temp1), GET_CODE (temp2) == REG) | |
f95182a4 ILT |
1009 | && (! SMALL_REGISTER_CLASSES |
1010 | || REGNO (temp2) >= FIRST_PSEUDO_REGISTER) | |
2156dfe3 RK |
1011 | && GET_CODE (SET_SRC (temp1)) != REG |
1012 | && GET_CODE (SET_SRC (temp1)) != SUBREG | |
1013 | && GET_CODE (SET_SRC (temp1)) != CONST_INT | |
1014 | && ! side_effects_p (SET_SRC (temp1)) | |
1015 | && ! may_trap_p (SET_SRC (temp1)) | |
97fa962f | 1016 | && rtx_cost (SET_SRC (temp1), SET) < 10) |
2156dfe3 RK |
1017 | { |
1018 | rtx new = gen_reg_rtx (GET_MODE (temp2)); | |
1019 | ||
956d6950 JL |
1020 | if ((temp3 = find_insert_position (insn, temp)) |
1021 | && validate_change (temp, &SET_DEST (temp1), new, 0)) | |
2156dfe3 RK |
1022 | { |
1023 | next = emit_insn_after (gen_move_insn (temp2, new), insn); | |
1024 | emit_insn_after_with_line_notes (PATTERN (temp), | |
956d6950 | 1025 | PREV_INSN (temp3), temp); |
2156dfe3 | 1026 | delete_insn (temp); |
5954c8a8 | 1027 | reallabelprev = prev_active_insn (JUMP_LABEL (insn)); |
f903b91f DM |
1028 | |
1029 | if (after_regscan) | |
1030 | { | |
1031 | reg_scan_update (temp3, NEXT_INSN (next), old_max_reg); | |
1032 | old_max_reg = max_reg_num (); | |
1033 | } | |
2156dfe3 RK |
1034 | } |
1035 | } | |
1036 | ||
1037 | /* Similarly, if it takes two insns to compute EXP but they | |
1038 | have the same destination. Here TEMP3 will be the second | |
1039 | insn and TEMP4 the SET from that insn. */ | |
1040 | ||
1041 | if (! reload_completed | |
1042 | && this_is_condjump && ! this_is_simplejump | |
1043 | && BRANCH_COST >= 4 | |
1044 | && (temp = next_nonnote_insn (insn)) != 0 | |
a8fc41af | 1045 | && GET_CODE (temp) == INSN |
2156dfe3 RK |
1046 | && REG_NOTES (temp) == 0 |
1047 | && (temp3 = next_nonnote_insn (temp)) != 0 | |
a8fc41af | 1048 | && GET_CODE (temp3) == INSN |
2156dfe3 RK |
1049 | && REG_NOTES (temp3) == 0 |
1050 | && (reallabelprev == temp3 | |
1051 | || ((temp2 = next_active_insn (temp3)) != 0 | |
1052 | && simplejump_p (temp2) | |
1053 | && JUMP_LABEL (temp2) == JUMP_LABEL (insn))) | |
1054 | && (temp1 = single_set (temp)) != 0 | |
1055 | && (temp2 = SET_DEST (temp1), GET_CODE (temp2) == REG) | |
1056 | && GET_MODE_CLASS (GET_MODE (temp2)) == MODE_INT | |
f95182a4 ILT |
1057 | && (! SMALL_REGISTER_CLASSES |
1058 | || REGNO (temp2) >= FIRST_PSEUDO_REGISTER) | |
2156dfe3 RK |
1059 | && ! side_effects_p (SET_SRC (temp1)) |
1060 | && ! may_trap_p (SET_SRC (temp1)) | |
97fa962f | 1061 | && rtx_cost (SET_SRC (temp1), SET) < 10 |
2156dfe3 RK |
1062 | && (temp4 = single_set (temp3)) != 0 |
1063 | && rtx_equal_p (SET_DEST (temp4), temp2) | |
1064 | && ! side_effects_p (SET_SRC (temp4)) | |
1065 | && ! may_trap_p (SET_SRC (temp4)) | |
97fa962f | 1066 | && rtx_cost (SET_SRC (temp4), SET) < 10) |
2156dfe3 RK |
1067 | { |
1068 | rtx new = gen_reg_rtx (GET_MODE (temp2)); | |
1069 | ||
956d6950 JL |
1070 | if ((temp5 = find_insert_position (insn, temp)) |
1071 | && (temp6 = find_insert_position (insn, temp3)) | |
1072 | && validate_change (temp, &SET_DEST (temp1), new, 0)) | |
2156dfe3 | 1073 | { |
956d6950 JL |
1074 | /* Use the earliest of temp5 and temp6. */ |
1075 | if (temp5 != insn) | |
1076 | temp6 = temp5; | |
2156dfe3 RK |
1077 | next = emit_insn_after (gen_move_insn (temp2, new), insn); |
1078 | emit_insn_after_with_line_notes (PATTERN (temp), | |
956d6950 | 1079 | PREV_INSN (temp6), temp); |
2156dfe3 RK |
1080 | emit_insn_after_with_line_notes |
1081 | (replace_rtx (PATTERN (temp3), temp2, new), | |
956d6950 | 1082 | PREV_INSN (temp6), temp3); |
2156dfe3 RK |
1083 | delete_insn (temp); |
1084 | delete_insn (temp3); | |
5954c8a8 | 1085 | reallabelprev = prev_active_insn (JUMP_LABEL (insn)); |
f903b91f DM |
1086 | |
1087 | if (after_regscan) | |
1088 | { | |
1089 | reg_scan_update (temp6, NEXT_INSN (next), old_max_reg); | |
1090 | old_max_reg = max_reg_num (); | |
1091 | } | |
2156dfe3 RK |
1092 | } |
1093 | } | |
1094 | ||
1095 | /* Finally, handle the case where two insns are used to | |
1096 | compute EXP but a temporary register is used. Here we must | |
0f41302f | 1097 | ensure that the temporary register is not used anywhere else. */ |
2156dfe3 RK |
1098 | |
1099 | if (! reload_completed | |
1100 | && after_regscan | |
1101 | && this_is_condjump && ! this_is_simplejump | |
1102 | && BRANCH_COST >= 4 | |
1103 | && (temp = next_nonnote_insn (insn)) != 0 | |
a8fc41af | 1104 | && GET_CODE (temp) == INSN |
2156dfe3 RK |
1105 | && REG_NOTES (temp) == 0 |
1106 | && (temp3 = next_nonnote_insn (temp)) != 0 | |
a8fc41af | 1107 | && GET_CODE (temp3) == INSN |
2156dfe3 RK |
1108 | && REG_NOTES (temp3) == 0 |
1109 | && (reallabelprev == temp3 | |
1110 | || ((temp2 = next_active_insn (temp3)) != 0 | |
1111 | && simplejump_p (temp2) | |
1112 | && JUMP_LABEL (temp2) == JUMP_LABEL (insn))) | |
1113 | && (temp1 = single_set (temp)) != 0 | |
c03c4711 RK |
1114 | && (temp5 = SET_DEST (temp1), |
1115 | (GET_CODE (temp5) == REG | |
1116 | || (GET_CODE (temp5) == SUBREG | |
1117 | && (temp5 = SUBREG_REG (temp5), | |
1118 | GET_CODE (temp5) == REG)))) | |
2156dfe3 | 1119 | && REGNO (temp5) >= FIRST_PSEUDO_REGISTER |
b1f21e0a MM |
1120 | && REGNO_FIRST_UID (REGNO (temp5)) == INSN_UID (temp) |
1121 | && REGNO_LAST_UID (REGNO (temp5)) == INSN_UID (temp3) | |
2156dfe3 RK |
1122 | && ! side_effects_p (SET_SRC (temp1)) |
1123 | && ! may_trap_p (SET_SRC (temp1)) | |
97fa962f | 1124 | && rtx_cost (SET_SRC (temp1), SET) < 10 |
2156dfe3 RK |
1125 | && (temp4 = single_set (temp3)) != 0 |
1126 | && (temp2 = SET_DEST (temp4), GET_CODE (temp2) == REG) | |
1127 | && GET_MODE_CLASS (GET_MODE (temp2)) == MODE_INT | |
f95182a4 ILT |
1128 | && (! SMALL_REGISTER_CLASSES |
1129 | || REGNO (temp2) >= FIRST_PSEUDO_REGISTER) | |
2156dfe3 RK |
1130 | && rtx_equal_p (SET_DEST (temp4), temp2) |
1131 | && ! side_effects_p (SET_SRC (temp4)) | |
1132 | && ! may_trap_p (SET_SRC (temp4)) | |
97fa962f | 1133 | && rtx_cost (SET_SRC (temp4), SET) < 10) |
2156dfe3 RK |
1134 | { |
1135 | rtx new = gen_reg_rtx (GET_MODE (temp2)); | |
1136 | ||
956d6950 JL |
1137 | if ((temp5 = find_insert_position (insn, temp)) |
1138 | && (temp6 = find_insert_position (insn, temp3)) | |
1139 | && validate_change (temp3, &SET_DEST (temp4), new, 0)) | |
2156dfe3 | 1140 | { |
956d6950 JL |
1141 | /* Use the earliest of temp5 and temp6. */ |
1142 | if (temp5 != insn) | |
1143 | temp6 = temp5; | |
2156dfe3 RK |
1144 | next = emit_insn_after (gen_move_insn (temp2, new), insn); |
1145 | emit_insn_after_with_line_notes (PATTERN (temp), | |
956d6950 | 1146 | PREV_INSN (temp6), temp); |
2156dfe3 | 1147 | emit_insn_after_with_line_notes (PATTERN (temp3), |
956d6950 | 1148 | PREV_INSN (temp6), temp3); |
2156dfe3 RK |
1149 | delete_insn (temp); |
1150 | delete_insn (temp3); | |
5954c8a8 | 1151 | reallabelprev = prev_active_insn (JUMP_LABEL (insn)); |
f903b91f DM |
1152 | |
1153 | if (after_regscan) | |
1154 | { | |
1155 | reg_scan_update (temp6, NEXT_INSN (next), old_max_reg); | |
1156 | old_max_reg = max_reg_num (); | |
1157 | } | |
2156dfe3 RK |
1158 | } |
1159 | } | |
1160 | #endif /* HAVE_cc0 */ | |
1161 | ||
7209f1f9 DE |
1162 | /* Try to use a conditional move (if the target has them), or a |
1163 | store-flag insn. The general case is: | |
1164 | ||
1165 | 1) x = a; if (...) x = b; and | |
1166 | 2) if (...) x = b; | |
1167 | ||
1168 | If the jump would be faster, the machine should not have defined | |
1169 | the movcc or scc insns!. These cases are often made by the | |
3915de94 | 1170 | previous optimization. |
15a63be1 | 1171 | |
7209f1f9 DE |
1172 | The second case is treated as x = x; if (...) x = b;. |
1173 | ||
15a63be1 RK |
1174 | INSN here is the jump around the store. We set: |
1175 | ||
1176 | TEMP to the "x = b;" insn. | |
1177 | TEMP1 to X. | |
7209f1f9 | 1178 | TEMP2 to B. |
15a63be1 RK |
1179 | TEMP3 to A (X in the second case). |
1180 | TEMP4 to the condition being tested. | |
1181 | TEMP5 to the earliest insn used to find the condition. */ | |
1182 | ||
1183 | if (/* We can't do this after reload has completed. */ | |
1184 | ! reload_completed | |
1185 | && this_is_condjump && ! this_is_simplejump | |
1186 | /* Set TEMP to the "x = b;" insn. */ | |
1187 | && (temp = next_nonnote_insn (insn)) != 0 | |
1188 | && GET_CODE (temp) == INSN | |
1189 | && GET_CODE (PATTERN (temp)) == SET | |
1190 | && GET_CODE (temp1 = SET_DEST (PATTERN (temp))) == REG | |
f95182a4 ILT |
1191 | && (! SMALL_REGISTER_CLASSES |
1192 | || REGNO (temp1) >= FIRST_PSEUDO_REGISTER) | |
0bef9b8d RH |
1193 | && ! side_effects_p (temp2 = SET_SRC (PATTERN (temp))) |
1194 | && ! may_trap_p (temp2) | |
2156dfe3 RK |
1195 | /* Allow either form, but prefer the former if both apply. |
1196 | There is no point in using the old value of TEMP1 if | |
1197 | it is a register, since cse will alias them. It can | |
1198 | lose if the old value were a hard register since CSE | |
c85f7c16 JL |
1199 | won't replace hard registers. Avoid using TEMP3 if |
1200 | small register classes and it is a hard register. */ | |
1201 | && (((temp3 = reg_set_last (temp1, insn)) != 0 | |
1202 | && ! (SMALL_REGISTER_CLASSES && GET_CODE (temp3) == REG | |
1203 | && REGNO (temp3) < FIRST_PSEUDO_REGISTER)) | |
7209f1f9 DE |
1204 | /* Make the latter case look like x = x; if (...) x = b; */ |
1205 | || (temp3 = temp1, 1)) | |
15a63be1 RK |
1206 | /* INSN must either branch to the insn after TEMP or the insn |
1207 | after TEMP must branch to the same place as INSN. */ | |
1208 | && (reallabelprev == temp | |
1209 | || ((temp4 = next_active_insn (temp)) != 0 | |
1210 | && simplejump_p (temp4) | |
1211 | && JUMP_LABEL (temp4) == JUMP_LABEL (insn))) | |
1212 | && (temp4 = get_condition (insn, &temp5)) != 0 | |
7124e1e5 RS |
1213 | /* We must be comparing objects whose modes imply the size. |
1214 | We could handle BLKmode if (1) emit_store_flag could | |
1215 | and (2) we could find the size reliably. */ | |
1216 | && GET_MODE (XEXP (temp4, 0)) != BLKmode | |
04d23d7c RK |
1217 | /* Even if branches are cheap, the store_flag optimization |
1218 | can win when the operation to be performed can be | |
1219 | expressed directly. */ | |
2156dfe3 RK |
1220 | #ifdef HAVE_cc0 |
1221 | /* If the previous insn sets CC0 and something else, we can't | |
1222 | do this since we are going to delete that insn. */ | |
1223 | ||
1224 | && ! ((temp6 = prev_nonnote_insn (insn)) != 0 | |
1225 | && GET_CODE (temp6) == INSN | |
01ca1b91 RK |
1226 | && (sets_cc0_p (PATTERN (temp6)) == -1 |
1227 | || (sets_cc0_p (PATTERN (temp6)) == 1 | |
1228 | && FIND_REG_INC_NOTE (temp6, NULL_RTX)))) | |
2156dfe3 RK |
1229 | #endif |
1230 | ) | |
15a63be1 | 1231 | { |
7209f1f9 DE |
1232 | #ifdef HAVE_conditional_move |
1233 | /* First try a conditional move. */ | |
1234 | { | |
1235 | enum rtx_code code = GET_CODE (temp4); | |
1236 | rtx var = temp1; | |
1237 | rtx cond0, cond1, aval, bval; | |
1238 | rtx target; | |
1239 | ||
1240 | /* Copy the compared variables into cond0 and cond1, so that | |
1241 | any side effects performed in or after the old comparison, | |
1242 | will not affect our compare which will come later. */ | |
1243 | /* ??? Is it possible to just use the comparison in the jump | |
1244 | insn? After all, we're going to delete it. We'd have | |
1245 | to modify emit_conditional_move to take a comparison rtx | |
1246 | instead or write a new function. */ | |
1247 | cond0 = gen_reg_rtx (GET_MODE (XEXP (temp4, 0))); | |
1248 | /* We want the target to be able to simplify comparisons with | |
1249 | zero (and maybe other constants as well), so don't create | |
1250 | pseudos for them. There's no need to either. */ | |
1251 | if (GET_CODE (XEXP (temp4, 1)) == CONST_INT | |
1252 | || GET_CODE (XEXP (temp4, 1)) == CONST_DOUBLE) | |
1253 | cond1 = XEXP (temp4, 1); | |
1254 | else | |
1255 | cond1 = gen_reg_rtx (GET_MODE (XEXP (temp4, 1))); | |
1256 | ||
1257 | aval = temp3; | |
1258 | bval = temp2; | |
1259 | ||
1260 | start_sequence (); | |
1261 | target = emit_conditional_move (var, code, | |
1262 | cond0, cond1, VOIDmode, | |
1263 | aval, bval, GET_MODE (var), | |
1264 | (code == LTU || code == GEU | |
1265 | || code == LEU || code == GTU)); | |
1266 | ||
1267 | if (target) | |
1268 | { | |
f903b91f | 1269 | rtx seq1,seq2,last; |
7209f1f9 DE |
1270 | |
1271 | /* Save the conditional move sequence but don't emit it | |
1272 | yet. On some machines, like the alpha, it is possible | |
1273 | that temp5 == insn, so next generate the sequence that | |
1274 | saves the compared values and then emit both | |
1275 | sequences ensuring seq1 occurs before seq2. */ | |
1276 | seq2 = get_insns (); | |
1277 | end_sequence (); | |
1278 | ||
1279 | /* Now that we can't fail, generate the copy insns that | |
1280 | preserve the compared values. */ | |
1281 | start_sequence (); | |
1282 | emit_move_insn (cond0, XEXP (temp4, 0)); | |
1283 | if (cond1 != XEXP (temp4, 1)) | |
1284 | emit_move_insn (cond1, XEXP (temp4, 1)); | |
1285 | seq1 = get_insns (); | |
1286 | end_sequence (); | |
1287 | ||
1288 | emit_insns_before (seq1, temp5); | |
777e434c RK |
1289 | /* Insert conditional move after insn, to be sure that |
1290 | the jump and a possible compare won't be separated */ | |
f903b91f | 1291 | last = emit_insns_after (seq2, insn); |
7209f1f9 DE |
1292 | |
1293 | /* ??? We can also delete the insn that sets X to A. | |
1294 | Flow will do it too though. */ | |
1295 | delete_insn (temp); | |
1296 | next = NEXT_INSN (insn); | |
1297 | delete_jump (insn); | |
f903b91f DM |
1298 | |
1299 | if (after_regscan) | |
1300 | { | |
1301 | reg_scan_update (seq1, NEXT_INSN (last), old_max_reg); | |
1302 | old_max_reg = max_reg_num (); | |
1303 | } | |
1304 | ||
7209f1f9 DE |
1305 | changed = 1; |
1306 | continue; | |
1307 | } | |
1308 | else | |
2156dfe3 | 1309 | end_sequence (); |
7209f1f9 DE |
1310 | } |
1311 | #endif | |
2156dfe3 | 1312 | |
7209f1f9 DE |
1313 | /* That didn't work, try a store-flag insn. |
1314 | ||
1315 | We further divide the cases into: | |
1316 | ||
1317 | 1) x = a; if (...) x = b; and either A or B is zero, | |
1318 | 2) if (...) x = 0; and jumps are expensive, | |
1319 | 3) x = a; if (...) x = b; and A and B are constants where all | |
1320 | the set bits in A are also set in B and jumps are expensive, | |
1321 | 4) x = a; if (...) x = b; and A and B non-zero, and jumps are | |
1322 | more expensive, and | |
1323 | 5) if (...) x = b; if jumps are even more expensive. */ | |
1324 | ||
1325 | if (GET_MODE_CLASS (GET_MODE (temp1)) == MODE_INT | |
1326 | && ((GET_CODE (temp3) == CONST_INT) | |
1327 | /* Make the latter case look like | |
1328 | x = x; if (...) x = 0; */ | |
1329 | || (temp3 = temp1, | |
1330 | ((BRANCH_COST >= 2 | |
1331 | && temp2 == const0_rtx) | |
1332 | || BRANCH_COST >= 3))) | |
1333 | /* If B is zero, OK; if A is zero, can only do (1) if we | |
1334 | can reverse the condition. See if (3) applies possibly | |
1335 | by reversing the condition. Prefer reversing to (4) when | |
1336 | branches are very expensive. */ | |
04d23d7c RK |
1337 | && (((BRANCH_COST >= 2 |
1338 | || STORE_FLAG_VALUE == -1 | |
1339 | || (STORE_FLAG_VALUE == 1 | |
1340 | /* Check that the mask is a power of two, | |
1341 | so that it can probably be generated | |
1342 | with a shift. */ | |
702d7434 | 1343 | && GET_CODE (temp3) == CONST_INT |
04d23d7c RK |
1344 | && exact_log2 (INTVAL (temp3)) >= 0)) |
1345 | && (reversep = 0, temp2 == const0_rtx)) | |
1346 | || ((BRANCH_COST >= 2 | |
1347 | || STORE_FLAG_VALUE == -1 | |
1348 | || (STORE_FLAG_VALUE == 1 | |
702d7434 | 1349 | && GET_CODE (temp2) == CONST_INT |
04d23d7c RK |
1350 | && exact_log2 (INTVAL (temp2)) >= 0)) |
1351 | && temp3 == const0_rtx | |
7209f1f9 DE |
1352 | && (reversep = can_reverse_comparison_p (temp4, insn))) |
1353 | || (BRANCH_COST >= 2 | |
1354 | && GET_CODE (temp2) == CONST_INT | |
1355 | && GET_CODE (temp3) == CONST_INT | |
1356 | && ((INTVAL (temp2) & INTVAL (temp3)) == INTVAL (temp2) | |
1357 | || ((INTVAL (temp2) & INTVAL (temp3)) == INTVAL (temp3) | |
1358 | && (reversep = can_reverse_comparison_p (temp4, | |
1359 | insn))))) | |
1360 | || BRANCH_COST >= 3) | |
1361 | ) | |
1362 | { | |
1363 | enum rtx_code code = GET_CODE (temp4); | |
1364 | rtx uval, cval, var = temp1; | |
1365 | int normalizep; | |
1366 | rtx target; | |
1367 | ||
1368 | /* If necessary, reverse the condition. */ | |
1369 | if (reversep) | |
1370 | code = reverse_condition (code), uval = temp2, cval = temp3; | |
1371 | else | |
1372 | uval = temp3, cval = temp2; | |
1373 | ||
1374 | /* If CVAL is non-zero, normalize to -1. Otherwise, if UVAL | |
1375 | is the constant 1, it is best to just compute the result | |
1376 | directly. If UVAL is constant and STORE_FLAG_VALUE | |
1377 | includes all of its bits, it is best to compute the flag | |
1378 | value unnormalized and `and' it with UVAL. Otherwise, | |
1379 | normalize to -1 and `and' with UVAL. */ | |
1380 | normalizep = (cval != const0_rtx ? -1 | |
1381 | : (uval == const1_rtx ? 1 | |
1382 | : (GET_CODE (uval) == CONST_INT | |
1383 | && (INTVAL (uval) & ~STORE_FLAG_VALUE) == 0) | |
1384 | ? 0 : -1)); | |
1385 | ||
1386 | /* We will be putting the store-flag insn immediately in | |
1387 | front of the comparison that was originally being done, | |
1388 | so we know all the variables in TEMP4 will be valid. | |
1389 | However, this might be in front of the assignment of | |
1390 | A to VAR. If it is, it would clobber the store-flag | |
1391 | we will be emitting. | |
1392 | ||
1393 | Therefore, emit into a temporary which will be copied to | |
1394 | VAR immediately after TEMP. */ | |
2156dfe3 RK |
1395 | |
1396 | start_sequence (); | |
7209f1f9 DE |
1397 | target = emit_store_flag (gen_reg_rtx (GET_MODE (var)), code, |
1398 | XEXP (temp4, 0), XEXP (temp4, 1), | |
1399 | VOIDmode, | |
1400 | (code == LTU || code == LEU | |
1401 | || code == GEU || code == GTU), | |
1402 | normalizep); | |
1403 | if (target) | |
3915de94 | 1404 | { |
7209f1f9 DE |
1405 | rtx seq; |
1406 | rtx before = insn; | |
3915de94 | 1407 | |
7209f1f9 DE |
1408 | seq = get_insns (); |
1409 | end_sequence (); | |
3915de94 | 1410 | |
7209f1f9 DE |
1411 | /* Put the store-flag insns in front of the first insn |
1412 | used to compute the condition to ensure that we | |
1413 | use the same values of them as the current | |
1414 | comparison. However, the remainder of the insns we | |
1415 | generate will be placed directly in front of the | |
1416 | jump insn, in case any of the pseudos we use | |
1417 | are modified earlier. */ | |
3915de94 | 1418 | |
7209f1f9 | 1419 | emit_insns_before (seq, temp5); |
3915de94 | 1420 | |
7209f1f9 DE |
1421 | start_sequence (); |
1422 | ||
1423 | /* Both CVAL and UVAL are non-zero. */ | |
1424 | if (cval != const0_rtx && uval != const0_rtx) | |
c71ebae3 | 1425 | { |
7209f1f9 DE |
1426 | rtx tem1, tem2; |
1427 | ||
1428 | tem1 = expand_and (uval, target, NULL_RTX); | |
1429 | if (GET_CODE (cval) == CONST_INT | |
1430 | && GET_CODE (uval) == CONST_INT | |
1431 | && (INTVAL (cval) & INTVAL (uval)) == INTVAL (cval)) | |
1432 | tem2 = cval; | |
1433 | else | |
1434 | { | |
1435 | tem2 = expand_unop (GET_MODE (var), one_cmpl_optab, | |
1436 | target, NULL_RTX, 0); | |
1437 | tem2 = expand_and (cval, tem2, | |
1438 | (GET_CODE (tem2) == REG | |
1439 | ? tem2 : 0)); | |
1440 | } | |
1441 | ||
1442 | /* If we usually make new pseudos, do so here. This | |
1443 | turns out to help machines that have conditional | |
1444 | move insns. */ | |
1445 | /* ??? Conditional moves have already been handled. | |
1446 | This may be obsolete. */ | |
1447 | ||
1448 | if (flag_expensive_optimizations) | |
1449 | target = 0; | |
1450 | ||
1451 | target = expand_binop (GET_MODE (var), ior_optab, | |
1452 | tem1, tem2, target, | |
1453 | 1, OPTAB_WIDEN); | |
c71ebae3 | 1454 | } |
7209f1f9 DE |
1455 | else if (normalizep != 1) |
1456 | { | |
1457 | /* We know that either CVAL or UVAL is zero. If | |
1458 | UVAL is zero, negate TARGET and `and' with CVAL. | |
1459 | Otherwise, `and' with UVAL. */ | |
1460 | if (uval == const0_rtx) | |
1461 | { | |
1462 | target = expand_unop (GET_MODE (var), one_cmpl_optab, | |
1463 | target, NULL_RTX, 0); | |
1464 | uval = cval; | |
1465 | } | |
c71ebae3 | 1466 | |
7209f1f9 DE |
1467 | target = expand_and (uval, target, |
1468 | (GET_CODE (target) == REG | |
1469 | && ! preserve_subexpressions_p () | |
1470 | ? target : NULL_RTX)); | |
1471 | } | |
3915de94 | 1472 | |
7209f1f9 DE |
1473 | emit_move_insn (var, target); |
1474 | seq = get_insns (); | |
1475 | end_sequence (); | |
01ca1b91 | 1476 | #ifdef HAVE_cc0 |
7209f1f9 DE |
1477 | /* If INSN uses CC0, we must not separate it from the |
1478 | insn that sets cc0. */ | |
1479 | if (reg_mentioned_p (cc0_rtx, PATTERN (before))) | |
1480 | before = prev_nonnote_insn (before); | |
01ca1b91 | 1481 | #endif |
7209f1f9 | 1482 | emit_insns_before (seq, before); |
01ca1b91 | 1483 | |
7209f1f9 DE |
1484 | delete_insn (temp); |
1485 | next = NEXT_INSN (insn); | |
1486 | delete_jump (insn); | |
f903b91f DM |
1487 | |
1488 | if (after_regscan) | |
1489 | { | |
1490 | reg_scan_update (seq, NEXT_INSN (next), old_max_reg); | |
1491 | old_max_reg = max_reg_num (); | |
1492 | } | |
1493 | ||
7209f1f9 DE |
1494 | changed = 1; |
1495 | continue; | |
1496 | } | |
1497 | else | |
1498 | end_sequence (); | |
15a63be1 | 1499 | } |
15a63be1 RK |
1500 | } |
1501 | ||
1502 | /* If branches are expensive, convert | |
1503 | if (foo) bar++; to bar += (foo != 0); | |
1504 | and similarly for "bar--;" | |
1505 | ||
1506 | INSN is the conditional branch around the arithmetic. We set: | |
1507 | ||
1508 | TEMP is the arithmetic insn. | |
6dc42e49 | 1509 | TEMP1 is the SET doing the arithmetic. |
15a63be1 RK |
1510 | TEMP2 is the operand being incremented or decremented. |
1511 | TEMP3 to the condition being tested. | |
1512 | TEMP4 to the earliest insn used to find the condition. */ | |
1513 | ||
a8d916d3 | 1514 | if ((BRANCH_COST >= 2 |
48f16828 | 1515 | #ifdef HAVE_incscc |
a8d916d3 | 1516 | || HAVE_incscc |
48f16828 RK |
1517 | #endif |
1518 | #ifdef HAVE_decscc | |
d3907945 | 1519 | || HAVE_decscc |
a8d916d3 JL |
1520 | #endif |
1521 | ) | |
15a63be1 RK |
1522 | && ! reload_completed |
1523 | && this_is_condjump && ! this_is_simplejump | |
1524 | && (temp = next_nonnote_insn (insn)) != 0 | |
1525 | && (temp1 = single_set (temp)) != 0 | |
1526 | && (temp2 = SET_DEST (temp1), | |
1527 | GET_MODE_CLASS (GET_MODE (temp2)) == MODE_INT) | |
1528 | && GET_CODE (SET_SRC (temp1)) == PLUS | |
1529 | && (XEXP (SET_SRC (temp1), 1) == const1_rtx | |
1530 | || XEXP (SET_SRC (temp1), 1) == constm1_rtx) | |
1531 | && rtx_equal_p (temp2, XEXP (SET_SRC (temp1), 0)) | |
8743ede9 RK |
1532 | && ! side_effects_p (temp2) |
1533 | && ! may_trap_p (temp2) | |
15a63be1 RK |
1534 | /* INSN must either branch to the insn after TEMP or the insn |
1535 | after TEMP must branch to the same place as INSN. */ | |
1536 | && (reallabelprev == temp | |
1537 | || ((temp3 = next_active_insn (temp)) != 0 | |
1538 | && simplejump_p (temp3) | |
1539 | && JUMP_LABEL (temp3) == JUMP_LABEL (insn))) | |
1540 | && (temp3 = get_condition (insn, &temp4)) != 0 | |
7124e1e5 RS |
1541 | /* We must be comparing objects whose modes imply the size. |
1542 | We could handle BLKmode if (1) emit_store_flag could | |
1543 | and (2) we could find the size reliably. */ | |
1544 | && GET_MODE (XEXP (temp3, 0)) != BLKmode | |
15a63be1 RK |
1545 | && can_reverse_comparison_p (temp3, insn)) |
1546 | { | |
626d0d1d | 1547 | rtx temp6, target = 0, seq, init_insn = 0, init = temp2; |
15a63be1 RK |
1548 | enum rtx_code code = reverse_condition (GET_CODE (temp3)); |
1549 | ||
1550 | start_sequence (); | |
1551 | ||
626d0d1d RK |
1552 | /* It must be the case that TEMP2 is not modified in the range |
1553 | [TEMP4, INSN). The one exception we make is if the insn | |
1554 | before INSN sets TEMP2 to something which is also unchanged | |
1555 | in that range. In that case, we can move the initialization | |
1556 | into our sequence. */ | |
1557 | ||
1558 | if ((temp5 = prev_active_insn (insn)) != 0 | |
19f5ce60 | 1559 | && no_labels_between_p (temp5, insn) |
626d0d1d RK |
1560 | && GET_CODE (temp5) == INSN |
1561 | && (temp6 = single_set (temp5)) != 0 | |
1562 | && rtx_equal_p (temp2, SET_DEST (temp6)) | |
1563 | && (CONSTANT_P (SET_SRC (temp6)) | |
1564 | || GET_CODE (SET_SRC (temp6)) == REG | |
1565 | || GET_CODE (SET_SRC (temp6)) == SUBREG)) | |
1566 | { | |
1567 | emit_insn (PATTERN (temp5)); | |
1568 | init_insn = temp5; | |
1569 | init = SET_SRC (temp6); | |
1570 | } | |
1571 | ||
1572 | if (CONSTANT_P (init) | |
1573 | || ! reg_set_between_p (init, PREV_INSN (temp4), insn)) | |
1574 | target = emit_store_flag (gen_reg_rtx (GET_MODE (temp2)), code, | |
1575 | XEXP (temp3, 0), XEXP (temp3, 1), | |
1576 | VOIDmode, | |
1577 | (code == LTU || code == LEU | |
1578 | || code == GTU || code == GEU), 1); | |
15a63be1 RK |
1579 | |
1580 | /* If we can do the store-flag, do the addition or | |
1581 | subtraction. */ | |
1582 | ||
1583 | if (target) | |
1584 | target = expand_binop (GET_MODE (temp2), | |
1585 | (XEXP (SET_SRC (temp1), 1) == const1_rtx | |
1586 | ? add_optab : sub_optab), | |
58f066d1 | 1587 | temp2, target, temp2, 0, OPTAB_WIDEN); |
15a63be1 RK |
1588 | |
1589 | if (target != 0) | |
1590 | { | |
1591 | /* Put the result back in temp2 in case it isn't already. | |
1592 | Then replace the jump, possible a CC0-setting insn in | |
1593 | front of the jump, and TEMP, with the sequence we have | |
1594 | made. */ | |
1595 | ||
1596 | if (target != temp2) | |
1597 | emit_move_insn (temp2, target); | |
1598 | ||
1599 | seq = get_insns (); | |
1600 | end_sequence (); | |
1601 | ||
1602 | emit_insns_before (seq, temp4); | |
1603 | delete_insn (temp); | |
626d0d1d RK |
1604 | |
1605 | if (init_insn) | |
1606 | delete_insn (init_insn); | |
1607 | ||
15a63be1 RK |
1608 | next = NEXT_INSN (insn); |
1609 | #ifdef HAVE_cc0 | |
1610 | delete_insn (prev_nonnote_insn (insn)); | |
1611 | #endif | |
1612 | delete_insn (insn); | |
f903b91f DM |
1613 | |
1614 | if (after_regscan) | |
1615 | { | |
1616 | reg_scan_update (seq, NEXT_INSN (next), old_max_reg); | |
1617 | old_max_reg = max_reg_num (); | |
1618 | } | |
1619 | ||
15a63be1 RK |
1620 | changed = 1; |
1621 | continue; | |
1622 | } | |
1623 | else | |
1624 | end_sequence (); | |
1625 | } | |
1626 | ||
1627 | /* Simplify if (...) x = 1; else {...} if (x) ... | |
1628 | We recognize this case scanning backwards as well. | |
1629 | ||
1630 | TEMP is the assignment to x; | |
1631 | TEMP1 is the label at the head of the second if. */ | |
1632 | /* ?? This should call get_condition to find the values being | |
1633 | compared, instead of looking for a COMPARE insn when HAVE_cc0 | |
1634 | is not defined. This would allow it to work on the m88k. */ | |
1635 | /* ?? This optimization is only safe before cse is run if HAVE_cc0 | |
1636 | is not defined and the condition is tested by a separate compare | |
1637 | insn. This is because the code below assumes that the result | |
1638 | of the compare dies in the following branch. | |
1639 | ||
1640 | Not only that, but there might be other insns between the | |
1641 | compare and branch whose results are live. Those insns need | |
1642 | to be executed. | |
1643 | ||
1644 | A way to fix this is to move the insns at JUMP_LABEL (insn) | |
1645 | to before INSN. If we are running before flow, they will | |
1646 | be deleted if they aren't needed. But this doesn't work | |
1647 | well after flow. | |
1648 | ||
1649 | This is really a special-case of jump threading, anyway. The | |
1650 | right thing to do is to replace this and jump threading with | |
1651 | much simpler code in cse. | |
1652 | ||
1653 | This code has been turned off in the non-cc0 case in the | |
1654 | meantime. */ | |
1655 | ||
1656 | #ifdef HAVE_cc0 | |
1657 | else if (this_is_simplejump | |
1658 | /* Safe to skip USE and CLOBBER insns here | |
1659 | since they will not be deleted. */ | |
1660 | && (temp = prev_active_insn (insn)) | |
1661 | && no_labels_between_p (temp, insn) | |
1662 | && GET_CODE (temp) == INSN | |
1663 | && GET_CODE (PATTERN (temp)) == SET | |
1664 | && GET_CODE (SET_DEST (PATTERN (temp))) == REG | |
1665 | && CONSTANT_P (SET_SRC (PATTERN (temp))) | |
1666 | && (temp1 = next_active_insn (JUMP_LABEL (insn))) | |
1667 | /* If we find that the next value tested is `x' | |
1668 | (TEMP1 is the insn where this happens), win. */ | |
1669 | && GET_CODE (temp1) == INSN | |
1670 | && GET_CODE (PATTERN (temp1)) == SET | |
1671 | #ifdef HAVE_cc0 | |
1672 | /* Does temp1 `tst' the value of x? */ | |
1673 | && SET_SRC (PATTERN (temp1)) == SET_DEST (PATTERN (temp)) | |
1674 | && SET_DEST (PATTERN (temp1)) == cc0_rtx | |
1675 | && (temp1 = next_nonnote_insn (temp1)) | |
1676 | #else | |
1677 | /* Does temp1 compare the value of x against zero? */ | |
1678 | && GET_CODE (SET_SRC (PATTERN (temp1))) == COMPARE | |
1679 | && XEXP (SET_SRC (PATTERN (temp1)), 1) == const0_rtx | |
1680 | && (XEXP (SET_SRC (PATTERN (temp1)), 0) | |
1681 | == SET_DEST (PATTERN (temp))) | |
1682 | && GET_CODE (SET_DEST (PATTERN (temp1))) == REG | |
1683 | && (temp1 = find_next_ref (SET_DEST (PATTERN (temp1)), temp1)) | |
1684 | #endif | |
1685 | && condjump_p (temp1)) | |
1686 | { | |
1687 | /* Get the if_then_else from the condjump. */ | |
1688 | rtx choice = SET_SRC (PATTERN (temp1)); | |
1689 | if (GET_CODE (choice) == IF_THEN_ELSE) | |
1690 | { | |
1691 | enum rtx_code code = GET_CODE (XEXP (choice, 0)); | |
1692 | rtx val = SET_SRC (PATTERN (temp)); | |
1693 | rtx cond | |
1694 | = simplify_relational_operation (code, GET_MODE (SET_DEST (PATTERN (temp))), | |
1695 | val, const0_rtx); | |
1696 | rtx ultimate; | |
1697 | ||
1698 | if (cond == const_true_rtx) | |
1699 | ultimate = XEXP (choice, 1); | |
1700 | else if (cond == const0_rtx) | |
1701 | ultimate = XEXP (choice, 2); | |
1702 | else | |
1703 | ultimate = 0; | |
1704 | ||
1705 | if (ultimate == pc_rtx) | |
1706 | ultimate = get_label_after (temp1); | |
1707 | else if (ultimate && GET_CODE (ultimate) != RETURN) | |
1708 | ultimate = XEXP (ultimate, 0); | |
1709 | ||
9e390837 | 1710 | if (ultimate && JUMP_LABEL(insn) != ultimate) |
15a63be1 RK |
1711 | changed |= redirect_jump (insn, ultimate); |
1712 | } | |
1713 | } | |
1714 | #endif | |
1715 | ||
1716 | #if 0 | |
1717 | /* @@ This needs a bit of work before it will be right. | |
1718 | ||
1719 | Any type of comparison can be accepted for the first and | |
1720 | second compare. When rewriting the first jump, we must | |
1721 | compute the what conditions can reach label3, and use the | |
1722 | appropriate code. We can not simply reverse/swap the code | |
1723 | of the first jump. In some cases, the second jump must be | |
1724 | rewritten also. | |
1725 | ||
1726 | For example, | |
1727 | < == converts to > == | |
1728 | < != converts to == > | |
1729 | etc. | |
1730 | ||
1731 | If the code is written to only accept an '==' test for the second | |
1732 | compare, then all that needs to be done is to swap the condition | |
1733 | of the first branch. | |
1734 | ||
1735 | It is questionable whether we want this optimization anyways, | |
1736 | since if the user wrote code like this because he/she knew that | |
6dc42e49 | 1737 | the jump to label1 is taken most of the time, then rewriting |
15a63be1 RK |
1738 | this gives slower code. */ |
1739 | /* @@ This should call get_condition to find the values being | |
1740 | compared, instead of looking for a COMPARE insn when HAVE_cc0 | |
1741 | is not defined. This would allow it to work on the m88k. */ | |
1742 | /* @@ This optimization is only safe before cse is run if HAVE_cc0 | |
1743 | is not defined and the condition is tested by a separate compare | |
1744 | insn. This is because the code below assumes that the result | |
1745 | of the compare dies in the following branch. */ | |
1746 | ||
1747 | /* Simplify test a ~= b | |
1748 | condjump label1; | |
1749 | test a == b | |
1750 | condjump label2; | |
1751 | jump label3; | |
1752 | label1: | |
1753 | ||
1754 | rewriting as | |
1755 | test a ~~= b | |
1756 | condjump label3 | |
1757 | test a == b | |
1758 | condjump label2 | |
1759 | label1: | |
1760 | ||
1761 | where ~= is an inequality, e.g. >, and ~~= is the swapped | |
1762 | inequality, e.g. <. | |
1763 | ||
1764 | We recognize this case scanning backwards. | |
1765 | ||
1766 | TEMP is the conditional jump to `label2'; | |
1767 | TEMP1 is the test for `a == b'; | |
1768 | TEMP2 is the conditional jump to `label1'; | |
1769 | TEMP3 is the test for `a ~= b'. */ | |
1770 | else if (this_is_simplejump | |
1771 | && (temp = prev_active_insn (insn)) | |
1772 | && no_labels_between_p (temp, insn) | |
1773 | && condjump_p (temp) | |
1774 | && (temp1 = prev_active_insn (temp)) | |
1775 | && no_labels_between_p (temp1, temp) | |
1776 | && GET_CODE (temp1) == INSN | |
1777 | && GET_CODE (PATTERN (temp1)) == SET | |
1778 | #ifdef HAVE_cc0 | |
1779 | && sets_cc0_p (PATTERN (temp1)) == 1 | |
1780 | #else | |
1781 | && GET_CODE (SET_SRC (PATTERN (temp1))) == COMPARE | |
1782 | && GET_CODE (SET_DEST (PATTERN (temp1))) == REG | |
1783 | && (temp == find_next_ref (SET_DEST (PATTERN (temp1)), temp1)) | |
1784 | #endif | |
1785 | && (temp2 = prev_active_insn (temp1)) | |
1786 | && no_labels_between_p (temp2, temp1) | |
1787 | && condjump_p (temp2) | |
1788 | && JUMP_LABEL (temp2) == next_nonnote_insn (NEXT_INSN (insn)) | |
1789 | && (temp3 = prev_active_insn (temp2)) | |
1790 | && no_labels_between_p (temp3, temp2) | |
1791 | && GET_CODE (PATTERN (temp3)) == SET | |
1792 | && rtx_equal_p (SET_DEST (PATTERN (temp3)), | |
1793 | SET_DEST (PATTERN (temp1))) | |
1794 | && rtx_equal_p (SET_SRC (PATTERN (temp1)), | |
1795 | SET_SRC (PATTERN (temp3))) | |
1796 | && ! inequality_comparisons_p (PATTERN (temp)) | |
1797 | && inequality_comparisons_p (PATTERN (temp2))) | |
1798 | { | |
1799 | rtx fallthrough_label = JUMP_LABEL (temp2); | |
1800 | ||
1801 | ++LABEL_NUSES (fallthrough_label); | |
1802 | if (swap_jump (temp2, JUMP_LABEL (insn))) | |
1803 | { | |
1804 | delete_insn (insn); | |
1805 | changed = 1; | |
1806 | } | |
1807 | ||
1808 | if (--LABEL_NUSES (fallthrough_label) == 0) | |
1809 | delete_insn (fallthrough_label); | |
1810 | } | |
1811 | #endif | |
1812 | /* Simplify if (...) {... x = 1;} if (x) ... | |
1813 | ||
1814 | We recognize this case backwards. | |
1815 | ||
1816 | TEMP is the test of `x'; | |
1817 | TEMP1 is the assignment to `x' at the end of the | |
1818 | previous statement. */ | |
1819 | /* @@ This should call get_condition to find the values being | |
1820 | compared, instead of looking for a COMPARE insn when HAVE_cc0 | |
1821 | is not defined. This would allow it to work on the m88k. */ | |
1822 | /* @@ This optimization is only safe before cse is run if HAVE_cc0 | |
1823 | is not defined and the condition is tested by a separate compare | |
1824 | insn. This is because the code below assumes that the result | |
1825 | of the compare dies in the following branch. */ | |
2d20b9df RS |
1826 | |
1827 | /* ??? This has to be turned off. The problem is that the | |
1828 | unconditional jump might indirectly end up branching to the | |
1829 | label between TEMP1 and TEMP. We can't detect this, in general, | |
1830 | since it may become a jump to there after further optimizations. | |
1831 | If that jump is done, it will be deleted, so we will retry | |
1832 | this optimization in the next pass, thus an infinite loop. | |
1833 | ||
1834 | The present code prevents this by putting the jump after the | |
1835 | label, but this is not logically correct. */ | |
1836 | #if 0 | |
15a63be1 RK |
1837 | else if (this_is_condjump |
1838 | /* Safe to skip USE and CLOBBER insns here | |
1839 | since they will not be deleted. */ | |
1840 | && (temp = prev_active_insn (insn)) | |
1841 | && no_labels_between_p (temp, insn) | |
1842 | && GET_CODE (temp) == INSN | |
1843 | && GET_CODE (PATTERN (temp)) == SET | |
1844 | #ifdef HAVE_cc0 | |
1845 | && sets_cc0_p (PATTERN (temp)) == 1 | |
1846 | && GET_CODE (SET_SRC (PATTERN (temp))) == REG | |
1847 | #else | |
1848 | /* Temp must be a compare insn, we can not accept a register | |
1849 | to register move here, since it may not be simply a | |
1850 | tst insn. */ | |
1851 | && GET_CODE (SET_SRC (PATTERN (temp))) == COMPARE | |
1852 | && XEXP (SET_SRC (PATTERN (temp)), 1) == const0_rtx | |
1853 | && GET_CODE (XEXP (SET_SRC (PATTERN (temp)), 0)) == REG | |
1854 | && GET_CODE (SET_DEST (PATTERN (temp))) == REG | |
1855 | && insn == find_next_ref (SET_DEST (PATTERN (temp)), temp) | |
1856 | #endif | |
1857 | /* May skip USE or CLOBBER insns here | |
1858 | for checking for opportunity, since we | |
1859 | take care of them later. */ | |
1860 | && (temp1 = prev_active_insn (temp)) | |
1861 | && GET_CODE (temp1) == INSN | |
1862 | && GET_CODE (PATTERN (temp1)) == SET | |
1863 | #ifdef HAVE_cc0 | |
1864 | && SET_SRC (PATTERN (temp)) == SET_DEST (PATTERN (temp1)) | |
1865 | #else | |
1866 | && (XEXP (SET_SRC (PATTERN (temp)), 0) | |
1867 | == SET_DEST (PATTERN (temp1))) | |
1868 | #endif | |
1869 | && CONSTANT_P (SET_SRC (PATTERN (temp1))) | |
1870 | /* If this isn't true, cse will do the job. */ | |
1871 | && ! no_labels_between_p (temp1, temp)) | |
1872 | { | |
1873 | /* Get the if_then_else from the condjump. */ | |
1874 | rtx choice = SET_SRC (PATTERN (insn)); | |
1875 | if (GET_CODE (choice) == IF_THEN_ELSE | |
1876 | && (GET_CODE (XEXP (choice, 0)) == EQ | |
1877 | || GET_CODE (XEXP (choice, 0)) == NE)) | |
1878 | { | |
1879 | int want_nonzero = (GET_CODE (XEXP (choice, 0)) == NE); | |
1880 | rtx last_insn; | |
1881 | rtx ultimate; | |
1882 | rtx p; | |
1883 | ||
1884 | /* Get the place that condjump will jump to | |
1885 | if it is reached from here. */ | |
1886 | if ((SET_SRC (PATTERN (temp1)) != const0_rtx) | |
1887 | == want_nonzero) | |
1888 | ultimate = XEXP (choice, 1); | |
1889 | else | |
1890 | ultimate = XEXP (choice, 2); | |
1891 | /* Get it as a CODE_LABEL. */ | |
1892 | if (ultimate == pc_rtx) | |
1893 | ultimate = get_label_after (insn); | |
1894 | else | |
1895 | /* Get the label out of the LABEL_REF. */ | |
1896 | ultimate = XEXP (ultimate, 0); | |
1897 | ||
2d20b9df RS |
1898 | /* Insert the jump immediately before TEMP, specifically |
1899 | after the label that is between TEMP1 and TEMP. */ | |
1900 | last_insn = PREV_INSN (temp); | |
15a63be1 RK |
1901 | |
1902 | /* If we would be branching to the next insn, the jump | |
1903 | would immediately be deleted and the re-inserted in | |
1904 | a subsequent pass over the code. So don't do anything | |
1905 | in that case. */ | |
1906 | if (next_active_insn (last_insn) | |
1907 | != next_active_insn (ultimate)) | |
1908 | { | |
1909 | emit_barrier_after (last_insn); | |
1910 | p = emit_jump_insn_after (gen_jump (ultimate), | |
1911 | last_insn); | |
1912 | JUMP_LABEL (p) = ultimate; | |
1913 | ++LABEL_NUSES (ultimate); | |
1914 | if (INSN_UID (ultimate) < max_jump_chain | |
1915 | && INSN_CODE (p) < max_jump_chain) | |
1916 | { | |
1917 | jump_chain[INSN_UID (p)] | |
1918 | = jump_chain[INSN_UID (ultimate)]; | |
1919 | jump_chain[INSN_UID (ultimate)] = p; | |
1920 | } | |
1921 | changed = 1; | |
1922 | continue; | |
1923 | } | |
1924 | } | |
1925 | } | |
2d20b9df | 1926 | #endif |
15a63be1 RK |
1927 | /* Detect a conditional jump going to the same place |
1928 | as an immediately following unconditional jump. */ | |
1929 | else if (this_is_condjump | |
1930 | && (temp = next_active_insn (insn)) != 0 | |
1931 | && simplejump_p (temp) | |
1932 | && (next_active_insn (JUMP_LABEL (insn)) | |
1933 | == next_active_insn (JUMP_LABEL (temp)))) | |
1934 | { | |
f6a6a1b3 DE |
1935 | rtx tem = temp; |
1936 | ||
1937 | /* ??? Optional. Disables some optimizations, but makes | |
1938 | gcov output more accurate with -O. */ | |
1939 | if (flag_test_coverage && !reload_completed) | |
1940 | for (tem = insn; tem != temp; tem = NEXT_INSN (tem)) | |
1941 | if (GET_CODE (tem) == NOTE && NOTE_LINE_NUMBER (tem) > 0) | |
1942 | break; | |
1943 | ||
1944 | if (tem == temp) | |
1945 | { | |
1946 | delete_jump (insn); | |
1947 | changed = 1; | |
1948 | continue; | |
1949 | } | |
15a63be1 | 1950 | } |
e0cd0770 JC |
1951 | #ifdef HAVE_trap |
1952 | /* Detect a conditional jump jumping over an unconditional trap. */ | |
1953 | else if (HAVE_trap | |
1954 | && this_is_condjump && ! this_is_simplejump | |
1955 | && reallabelprev != 0 | |
1956 | && GET_CODE (reallabelprev) == INSN | |
1957 | && GET_CODE (PATTERN (reallabelprev)) == TRAP_IF | |
1958 | && TRAP_CONDITION (PATTERN (reallabelprev)) == const_true_rtx | |
1959 | && prev_active_insn (reallabelprev) == insn | |
1960 | && no_labels_between_p (insn, reallabelprev) | |
1961 | && (temp2 = get_condition (insn, &temp4)) | |
1962 | && can_reverse_comparison_p (temp2, insn)) | |
1963 | { | |
1964 | rtx new = gen_cond_trap (reverse_condition (GET_CODE (temp2)), | |
1965 | XEXP (temp2, 0), XEXP (temp2, 1), | |
1966 | TRAP_CODE (PATTERN (reallabelprev))); | |
1967 | ||
1968 | if (new) | |
1969 | { | |
1970 | emit_insn_before (new, temp4); | |
1971 | delete_insn (reallabelprev); | |
1972 | delete_jump (insn); | |
1973 | changed = 1; | |
1974 | continue; | |
1975 | } | |
1976 | } | |
1977 | /* Detect a jump jumping to an unconditional trap. */ | |
1978 | else if (HAVE_trap && this_is_condjump | |
1979 | && (temp = next_active_insn (JUMP_LABEL (insn))) | |
1980 | && GET_CODE (temp) == INSN | |
1981 | && GET_CODE (PATTERN (temp)) == TRAP_IF | |
1982 | && (this_is_simplejump | |
1983 | || (temp2 = get_condition (insn, &temp4)))) | |
1984 | { | |
1985 | rtx tc = TRAP_CONDITION (PATTERN (temp)); | |
1986 | ||
1987 | if (tc == const_true_rtx | |
1988 | || (! this_is_simplejump && rtx_equal_p (temp2, tc))) | |
1989 | { | |
1990 | rtx new; | |
1991 | /* Replace an unconditional jump to a trap with a trap. */ | |
1992 | if (this_is_simplejump) | |
1993 | { | |
1994 | emit_barrier_after (emit_insn_before (gen_trap (), insn)); | |
1995 | delete_jump (insn); | |
1996 | changed = 1; | |
1997 | continue; | |
1998 | } | |
1999 | new = gen_cond_trap (GET_CODE (temp2), XEXP (temp2, 0), | |
2000 | XEXP (temp2, 1), | |
2001 | TRAP_CODE (PATTERN (temp))); | |
2002 | if (new) | |
2003 | { | |
2004 | emit_insn_before (new, temp4); | |
2005 | delete_jump (insn); | |
2006 | changed = 1; | |
2007 | continue; | |
2008 | } | |
2009 | } | |
2010 | /* If the trap condition and jump condition are mutually | |
2011 | exclusive, redirect the jump to the following insn. */ | |
2012 | else if (GET_RTX_CLASS (GET_CODE (tc)) == '<' | |
2013 | && ! this_is_simplejump | |
2014 | && swap_condition (GET_CODE (temp2)) == GET_CODE (tc) | |
2015 | && rtx_equal_p (XEXP (tc, 0), XEXP (temp2, 0)) | |
2016 | && rtx_equal_p (XEXP (tc, 1), XEXP (temp2, 1)) | |
2017 | && redirect_jump (insn, get_label_after (temp))) | |
2018 | { | |
2019 | changed = 1; | |
2020 | continue; | |
2021 | } | |
2022 | } | |
2023 | #endif | |
2024 | ||
15a63be1 RK |
2025 | /* Detect a conditional jump jumping over an unconditional jump. */ |
2026 | ||
3480bb98 JL |
2027 | else if ((this_is_condjump || this_is_condjump_in_parallel) |
2028 | && ! this_is_simplejump | |
15a63be1 RK |
2029 | && reallabelprev != 0 |
2030 | && GET_CODE (reallabelprev) == JUMP_INSN | |
2031 | && prev_active_insn (reallabelprev) == insn | |
2032 | && no_labels_between_p (insn, reallabelprev) | |
2033 | && simplejump_p (reallabelprev)) | |
2034 | { | |
2035 | /* When we invert the unconditional jump, we will be | |
2036 | decrementing the usage count of its old label. | |
2037 | Make sure that we don't delete it now because that | |
2038 | might cause the following code to be deleted. */ | |
2039 | rtx prev_uses = prev_nonnote_insn (reallabelprev); | |
2040 | rtx prev_label = JUMP_LABEL (insn); | |
2041 | ||
e26a82e4 JW |
2042 | if (prev_label) |
2043 | ++LABEL_NUSES (prev_label); | |
15a63be1 RK |
2044 | |
2045 | if (invert_jump (insn, JUMP_LABEL (reallabelprev))) | |
2046 | { | |
2047 | /* It is very likely that if there are USE insns before | |
2048 | this jump, they hold REG_DEAD notes. These REG_DEAD | |
2049 | notes are no longer valid due to this optimization, | |
2050 | and will cause the life-analysis that following passes | |
2051 | (notably delayed-branch scheduling) to think that | |
2052 | these registers are dead when they are not. | |
2053 | ||
2054 | To prevent this trouble, we just remove the USE insns | |
2055 | from the insn chain. */ | |
2056 | ||
2057 | while (prev_uses && GET_CODE (prev_uses) == INSN | |
2058 | && GET_CODE (PATTERN (prev_uses)) == USE) | |
2059 | { | |
2060 | rtx useless = prev_uses; | |
2061 | prev_uses = prev_nonnote_insn (prev_uses); | |
2062 | delete_insn (useless); | |
2063 | } | |
2064 | ||
2065 | delete_insn (reallabelprev); | |
2066 | next = insn; | |
2067 | changed = 1; | |
2068 | } | |
2069 | ||
2070 | /* We can now safely delete the label if it is unreferenced | |
2071 | since the delete_insn above has deleted the BARRIER. */ | |
e26a82e4 | 2072 | if (prev_label && --LABEL_NUSES (prev_label) == 0) |
15a63be1 RK |
2073 | delete_insn (prev_label); |
2074 | continue; | |
2075 | } | |
2076 | else | |
2077 | { | |
2078 | /* Detect a jump to a jump. */ | |
2079 | ||
2080 | nlabel = follow_jumps (JUMP_LABEL (insn)); | |
2081 | if (nlabel != JUMP_LABEL (insn) | |
2082 | && redirect_jump (insn, nlabel)) | |
2083 | { | |
2084 | changed = 1; | |
2085 | next = insn; | |
2086 | } | |
2087 | ||
2088 | /* Look for if (foo) bar; else break; */ | |
2089 | /* The insns look like this: | |
2090 | insn = condjump label1; | |
2091 | ...range1 (some insns)... | |
2092 | jump label2; | |
2093 | label1: | |
2094 | ...range2 (some insns)... | |
2095 | jump somewhere unconditionally | |
2096 | label2: */ | |
2097 | { | |
2098 | rtx label1 = next_label (insn); | |
2099 | rtx range1end = label1 ? prev_active_insn (label1) : 0; | |
2100 | /* Don't do this optimization on the first round, so that | |
2101 | jump-around-a-jump gets simplified before we ask here | |
2102 | whether a jump is unconditional. | |
2103 | ||
2104 | Also don't do it when we are called after reload since | |
2105 | it will confuse reorg. */ | |
2106 | if (! first | |
2107 | && (reload_completed ? ! flag_delayed_branch : 1) | |
2108 | /* Make sure INSN is something we can invert. */ | |
2109 | && condjump_p (insn) | |
2110 | && label1 != 0 | |
2111 | && JUMP_LABEL (insn) == label1 | |
2112 | && LABEL_NUSES (label1) == 1 | |
2113 | && GET_CODE (range1end) == JUMP_INSN | |
2114 | && simplejump_p (range1end)) | |
2115 | { | |
2116 | rtx label2 = next_label (label1); | |
2117 | rtx range2end = label2 ? prev_active_insn (label2) : 0; | |
2118 | if (range1end != range2end | |
2119 | && JUMP_LABEL (range1end) == label2 | |
2120 | && GET_CODE (range2end) == JUMP_INSN | |
2121 | && GET_CODE (NEXT_INSN (range2end)) == BARRIER | |
2122 | /* Invert the jump condition, so we | |
2123 | still execute the same insns in each case. */ | |
2124 | && invert_jump (insn, label1)) | |
2125 | { | |
2126 | rtx range1beg = next_active_insn (insn); | |
2127 | rtx range2beg = next_active_insn (label1); | |
2128 | rtx range1after, range2after; | |
2129 | rtx range1before, range2before; | |
f0e1b9a9 | 2130 | rtx rangenext; |
15a63be1 | 2131 | |
1f109a14 JW |
2132 | /* Include in each range any notes before it, to be |
2133 | sure that we get the line number note if any, even | |
2134 | if there are other notes here. */ | |
0e690bdb | 2135 | while (PREV_INSN (range1beg) |
1f109a14 | 2136 | && GET_CODE (PREV_INSN (range1beg)) == NOTE) |
0e690bdb RS |
2137 | range1beg = PREV_INSN (range1beg); |
2138 | ||
2139 | while (PREV_INSN (range2beg) | |
1f109a14 | 2140 | && GET_CODE (PREV_INSN (range2beg)) == NOTE) |
0e690bdb RS |
2141 | range2beg = PREV_INSN (range2beg); |
2142 | ||
15a63be1 RK |
2143 | /* Don't move NOTEs for blocks or loops; shift them |
2144 | outside the ranges, where they'll stay put. */ | |
915f619f JW |
2145 | range1beg = squeeze_notes (range1beg, range1end); |
2146 | range2beg = squeeze_notes (range2beg, range2end); | |
15a63be1 RK |
2147 | |
2148 | /* Get current surrounds of the 2 ranges. */ | |
2149 | range1before = PREV_INSN (range1beg); | |
2150 | range2before = PREV_INSN (range2beg); | |
2151 | range1after = NEXT_INSN (range1end); | |
2152 | range2after = NEXT_INSN (range2end); | |
2153 | ||
2154 | /* Splice range2 where range1 was. */ | |
2155 | NEXT_INSN (range1before) = range2beg; | |
2156 | PREV_INSN (range2beg) = range1before; | |
2157 | NEXT_INSN (range2end) = range1after; | |
2158 | PREV_INSN (range1after) = range2end; | |
2159 | /* Splice range1 where range2 was. */ | |
2160 | NEXT_INSN (range2before) = range1beg; | |
2161 | PREV_INSN (range1beg) = range2before; | |
2162 | NEXT_INSN (range1end) = range2after; | |
2163 | PREV_INSN (range2after) = range1end; | |
f0e1b9a9 RE |
2164 | |
2165 | /* Check for a loop end note between the end of | |
2166 | range2, and the next code label. If there is one, | |
2167 | then what we have really seen is | |
2168 | if (foo) break; end_of_loop; | |
2169 | and moved the break sequence outside the loop. | |
2170 | We must move the LOOP_END note to where the | |
2171 | loop really ends now, or we will confuse loop | |
ca188f16 JW |
2172 | optimization. Stop if we find a LOOP_BEG note |
2173 | first, since we don't want to move the LOOP_END | |
2174 | note in that case. */ | |
f0e1b9a9 RE |
2175 | for (;range2after != label2; range2after = rangenext) |
2176 | { | |
2177 | rangenext = NEXT_INSN (range2after); | |
ca188f16 | 2178 | if (GET_CODE (range2after) == NOTE) |
f0e1b9a9 | 2179 | { |
ca188f16 JW |
2180 | if (NOTE_LINE_NUMBER (range2after) |
2181 | == NOTE_INSN_LOOP_END) | |
2182 | { | |
2183 | NEXT_INSN (PREV_INSN (range2after)) | |
2184 | = rangenext; | |
2185 | PREV_INSN (rangenext) | |
2186 | = PREV_INSN (range2after); | |
2187 | PREV_INSN (range2after) | |
2188 | = PREV_INSN (range1beg); | |
2189 | NEXT_INSN (range2after) = range1beg; | |
2190 | NEXT_INSN (PREV_INSN (range1beg)) | |
2191 | = range2after; | |
2192 | PREV_INSN (range1beg) = range2after; | |
2193 | } | |
2194 | else if (NOTE_LINE_NUMBER (range2after) | |
2195 | == NOTE_INSN_LOOP_BEG) | |
2196 | break; | |
f0e1b9a9 RE |
2197 | } |
2198 | } | |
15a63be1 RK |
2199 | changed = 1; |
2200 | continue; | |
2201 | } | |
2202 | } | |
2203 | } | |
2204 | ||
2205 | /* Now that the jump has been tensioned, | |
2206 | try cross jumping: check for identical code | |
0f41302f | 2207 | before the jump and before its target label. */ |
15a63be1 RK |
2208 | |
2209 | /* First, cross jumping of conditional jumps: */ | |
2210 | ||
2211 | if (cross_jump && condjump_p (insn)) | |
2212 | { | |
2213 | rtx newjpos, newlpos; | |
2214 | rtx x = prev_real_insn (JUMP_LABEL (insn)); | |
2215 | ||
2216 | /* A conditional jump may be crossjumped | |
2217 | only if the place it jumps to follows | |
2218 | an opposing jump that comes back here. */ | |
2219 | ||
2220 | if (x != 0 && ! jump_back_p (x, insn)) | |
2221 | /* We have no opposing jump; | |
2222 | cannot cross jump this insn. */ | |
2223 | x = 0; | |
2224 | ||
2225 | newjpos = 0; | |
2226 | /* TARGET is nonzero if it is ok to cross jump | |
2227 | to code before TARGET. If so, see if matches. */ | |
2228 | if (x != 0) | |
2229 | find_cross_jump (insn, x, 2, | |
2230 | &newjpos, &newlpos); | |
2231 | ||
2232 | if (newjpos != 0) | |
2233 | { | |
2234 | do_cross_jump (insn, newjpos, newlpos); | |
2235 | /* Make the old conditional jump | |
2236 | into an unconditional one. */ | |
2237 | SET_SRC (PATTERN (insn)) | |
38a448ca | 2238 | = gen_rtx_LABEL_REF (VOIDmode, JUMP_LABEL (insn)); |
15a63be1 RK |
2239 | INSN_CODE (insn) = -1; |
2240 | emit_barrier_after (insn); | |
2241 | /* Add to jump_chain unless this is a new label | |
0f41302f | 2242 | whose UID is too large. */ |
15a63be1 RK |
2243 | if (INSN_UID (JUMP_LABEL (insn)) < max_jump_chain) |
2244 | { | |
2245 | jump_chain[INSN_UID (insn)] | |
2246 | = jump_chain[INSN_UID (JUMP_LABEL (insn))]; | |
2247 | jump_chain[INSN_UID (JUMP_LABEL (insn))] = insn; | |
2248 | } | |
2249 | changed = 1; | |
2250 | next = insn; | |
2251 | } | |
2252 | } | |
2253 | ||
2254 | /* Cross jumping of unconditional jumps: | |
2255 | a few differences. */ | |
2256 | ||
2257 | if (cross_jump && simplejump_p (insn)) | |
2258 | { | |
2259 | rtx newjpos, newlpos; | |
2260 | rtx target; | |
2261 | ||
2262 | newjpos = 0; | |
2263 | ||
2264 | /* TARGET is nonzero if it is ok to cross jump | |
2265 | to code before TARGET. If so, see if matches. */ | |
2266 | find_cross_jump (insn, JUMP_LABEL (insn), 1, | |
2267 | &newjpos, &newlpos); | |
2268 | ||
2269 | /* If cannot cross jump to code before the label, | |
2270 | see if we can cross jump to another jump to | |
2271 | the same label. */ | |
2272 | /* Try each other jump to this label. */ | |
2273 | if (INSN_UID (JUMP_LABEL (insn)) < max_uid) | |
2274 | for (target = jump_chain[INSN_UID (JUMP_LABEL (insn))]; | |
2275 | target != 0 && newjpos == 0; | |
2276 | target = jump_chain[INSN_UID (target)]) | |
2277 | if (target != insn | |
2278 | && JUMP_LABEL (target) == JUMP_LABEL (insn) | |
2279 | /* Ignore TARGET if it's deleted. */ | |
2280 | && ! INSN_DELETED_P (target)) | |
2281 | find_cross_jump (insn, target, 2, | |
2282 | &newjpos, &newlpos); | |
2283 | ||
2284 | if (newjpos != 0) | |
2285 | { | |
2286 | do_cross_jump (insn, newjpos, newlpos); | |
2287 | changed = 1; | |
2288 | next = insn; | |
2289 | } | |
2290 | } | |
2291 | ||
2292 | /* This code was dead in the previous jump.c! */ | |
2293 | if (cross_jump && GET_CODE (PATTERN (insn)) == RETURN) | |
2294 | { | |
2295 | /* Return insns all "jump to the same place" | |
2296 | so we can cross-jump between any two of them. */ | |
2297 | ||
2298 | rtx newjpos, newlpos, target; | |
2299 | ||
2300 | newjpos = 0; | |
2301 | ||
2302 | /* If cannot cross jump to code before the label, | |
2303 | see if we can cross jump to another jump to | |
2304 | the same label. */ | |
2305 | /* Try each other jump to this label. */ | |
2306 | for (target = jump_chain[0]; | |
2307 | target != 0 && newjpos == 0; | |
2308 | target = jump_chain[INSN_UID (target)]) | |
2309 | if (target != insn | |
2310 | && ! INSN_DELETED_P (target) | |
2311 | && GET_CODE (PATTERN (target)) == RETURN) | |
2312 | find_cross_jump (insn, target, 2, | |
2313 | &newjpos, &newlpos); | |
2314 | ||
2315 | if (newjpos != 0) | |
2316 | { | |
2317 | do_cross_jump (insn, newjpos, newlpos); | |
2318 | changed = 1; | |
2319 | next = insn; | |
2320 | } | |
2321 | } | |
2322 | } | |
2323 | } | |
2324 | ||
2325 | first = 0; | |
2326 | } | |
2327 | ||
2328 | /* Delete extraneous line number notes. | |
2329 | Note that two consecutive notes for different lines are not really | |
2330 | extraneous. There should be some indication where that line belonged, | |
2331 | even if it became empty. */ | |
2332 | ||
2333 | { | |
2334 | rtx last_note = 0; | |
2335 | ||
2336 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
2337 | if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) >= 0) | |
2338 | { | |
2339 | /* Delete this note if it is identical to previous note. */ | |
2340 | if (last_note | |
2341 | && NOTE_SOURCE_FILE (insn) == NOTE_SOURCE_FILE (last_note) | |
2342 | && NOTE_LINE_NUMBER (insn) == NOTE_LINE_NUMBER (last_note)) | |
2343 | { | |
2344 | delete_insn (insn); | |
2345 | continue; | |
2346 | } | |
2347 | ||
2348 | last_note = insn; | |
2349 | } | |
2350 | } | |
2351 | ||
683e6ccd RK |
2352 | #ifdef HAVE_return |
2353 | if (HAVE_return) | |
2354 | { | |
2355 | /* If we fall through to the epilogue, see if we can insert a RETURN insn | |
2356 | in front of it. If the machine allows it at this point (we might be | |
2357 | after reload for a leaf routine), it will improve optimization for it | |
2358 | to be there. We do this both here and at the start of this pass since | |
2359 | the RETURN might have been deleted by some of our optimizations. */ | |
2360 | insn = get_last_insn (); | |
2361 | while (insn && GET_CODE (insn) == NOTE) | |
2362 | insn = PREV_INSN (insn); | |
2363 | ||
2364 | if (insn && GET_CODE (insn) != BARRIER) | |
2365 | { | |
2366 | emit_jump_insn (gen_return ()); | |
2367 | emit_barrier (); | |
2368 | } | |
2369 | } | |
2370 | #endif | |
2371 | ||
15a63be1 RK |
2372 | /* See if there is still a NOTE_INSN_FUNCTION_END in this function. |
2373 | If so, delete it, and record that this function can drop off the end. */ | |
2374 | ||
2375 | insn = last_insn; | |
2376 | { | |
2377 | int n_labels = 1; | |
2378 | while (insn | |
2379 | /* One label can follow the end-note: the return label. */ | |
2380 | && ((GET_CODE (insn) == CODE_LABEL && n_labels-- > 0) | |
2381 | /* Ordinary insns can follow it if returning a structure. */ | |
2382 | || GET_CODE (insn) == INSN | |
2383 | /* If machine uses explicit RETURN insns, no epilogue, | |
2384 | then one of them follows the note. */ | |
2385 | || (GET_CODE (insn) == JUMP_INSN | |
2386 | && GET_CODE (PATTERN (insn)) == RETURN) | |
60374599 DE |
2387 | /* A barrier can follow the return insn. */ |
2388 | || GET_CODE (insn) == BARRIER | |
15a63be1 RK |
2389 | /* Other kinds of notes can follow also. */ |
2390 | || (GET_CODE (insn) == NOTE | |
2391 | && NOTE_LINE_NUMBER (insn) != NOTE_INSN_FUNCTION_END))) | |
2392 | insn = PREV_INSN (insn); | |
2393 | } | |
2394 | ||
2395 | /* Report if control can fall through at the end of the function. */ | |
2396 | if (insn && GET_CODE (insn) == NOTE | |
2397 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_END) | |
2398 | { | |
2399 | can_reach_end = 1; | |
2400 | delete_insn (insn); | |
2401 | } | |
2402 | ||
2403 | /* Show JUMP_CHAIN no longer valid. */ | |
2404 | jump_chain = 0; | |
2405 | } | |
2406 | \f | |
2407 | /* LOOP_START is a NOTE_INSN_LOOP_BEG note that is followed by an unconditional | |
2408 | jump. Assume that this unconditional jump is to the exit test code. If | |
2409 | the code is sufficiently simple, make a copy of it before INSN, | |
2410 | followed by a jump to the exit of the loop. Then delete the unconditional | |
2411 | jump after INSN. | |
2412 | ||
15a63be1 RK |
2413 | Return 1 if we made the change, else 0. |
2414 | ||
2415 | This is only safe immediately after a regscan pass because it uses the | |
2416 | values of regno_first_uid and regno_last_uid. */ | |
2417 | ||
2418 | static int | |
2419 | duplicate_loop_exit_test (loop_start) | |
2420 | rtx loop_start; | |
2421 | { | |
e33477be | 2422 | rtx insn, set, reg, p, link; |
9c066566 | 2423 | rtx copy = 0; |
15a63be1 RK |
2424 | int num_insns = 0; |
2425 | rtx exitcode = NEXT_INSN (JUMP_LABEL (next_nonnote_insn (loop_start))); | |
2426 | rtx lastexit; | |
2427 | int max_reg = max_reg_num (); | |
2428 | rtx *reg_map = 0; | |
2429 | ||
2430 | /* Scan the exit code. We do not perform this optimization if any insn: | |
2431 | ||
2432 | is a CALL_INSN | |
2433 | is a CODE_LABEL | |
2434 | has a REG_RETVAL or REG_LIBCALL note (hard to adjust) | |
2435 | is a NOTE_INSN_LOOP_BEG because this means we have a nested loop | |
2436 | is a NOTE_INSN_BLOCK_{BEG,END} because duplicating these notes | |
2437 | are not valid | |
752e74f9 JL |
2438 | |
2439 | ||
2440 | We also do not do this if we find an insn with ASM_OPERANDS. While | |
2441 | this restriction should not be necessary, copying an insn with | |
2442 | ASM_OPERANDS can confuse asm_noperands in some cases. | |
15a63be1 RK |
2443 | |
2444 | Also, don't do this if the exit code is more than 20 insns. */ | |
2445 | ||
2446 | for (insn = exitcode; | |
2447 | insn | |
2448 | && ! (GET_CODE (insn) == NOTE | |
2449 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END); | |
2450 | insn = NEXT_INSN (insn)) | |
2451 | { | |
2452 | switch (GET_CODE (insn)) | |
2453 | { | |
2454 | case CODE_LABEL: | |
2455 | case CALL_INSN: | |
2456 | return 0; | |
2457 | case NOTE: | |
fe464caf RK |
2458 | /* We could be in front of the wrong NOTE_INSN_LOOP_END if there is |
2459 | a jump immediately after the loop start that branches outside | |
2460 | the loop but within an outer loop, near the exit test. | |
2461 | If we copied this exit test and created a phony | |
2462 | NOTE_INSN_LOOP_VTOP, this could make instructions immediately | |
2463 | before the exit test look like these could be safely moved | |
2464 | out of the loop even if they actually may be never executed. | |
2465 | This can be avoided by checking here for NOTE_INSN_LOOP_CONT. */ | |
2466 | ||
15a63be1 | 2467 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG |
fe464caf | 2468 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_CONT) |
15a63be1 | 2469 | return 0; |
93de5c31 MM |
2470 | |
2471 | if (optimize < 2 | |
2472 | && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG | |
2473 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)) | |
2474 | /* If we were to duplicate this code, we would not move | |
2475 | the BLOCK notes, and so debugging the moved code would | |
2476 | be difficult. Thus, we only move the code with -O2 or | |
2477 | higher. */ | |
2478 | return 0; | |
2479 | ||
15a63be1 RK |
2480 | break; |
2481 | case JUMP_INSN: | |
2482 | case INSN: | |
2483 | if (++num_insns > 20 | |
5f4f0e22 | 2484 | || find_reg_note (insn, REG_RETVAL, NULL_RTX) |
752e74f9 | 2485 | || find_reg_note (insn, REG_LIBCALL, NULL_RTX) |
1eb6762b | 2486 | || asm_noperands (PATTERN (insn)) > 0) |
15a63be1 RK |
2487 | return 0; |
2488 | break; | |
e9a25f70 JL |
2489 | default: |
2490 | break; | |
15a63be1 RK |
2491 | } |
2492 | } | |
2493 | ||
2494 | /* Unless INSN is zero, we can do the optimization. */ | |
2495 | if (insn == 0) | |
2496 | return 0; | |
2497 | ||
2498 | lastexit = insn; | |
2499 | ||
2500 | /* See if any insn sets a register only used in the loop exit code and | |
2501 | not a user variable. If so, replace it with a new register. */ | |
2502 | for (insn = exitcode; insn != lastexit; insn = NEXT_INSN (insn)) | |
2503 | if (GET_CODE (insn) == INSN | |
2504 | && (set = single_set (insn)) != 0 | |
e33477be RK |
2505 | && ((reg = SET_DEST (set), GET_CODE (reg) == REG) |
2506 | || (GET_CODE (reg) == SUBREG | |
2507 | && (reg = SUBREG_REG (reg), GET_CODE (reg) == REG))) | |
2508 | && REGNO (reg) >= FIRST_PSEUDO_REGISTER | |
b1f21e0a | 2509 | && REGNO_FIRST_UID (REGNO (reg)) == INSN_UID (insn)) |
15a63be1 RK |
2510 | { |
2511 | for (p = NEXT_INSN (insn); p != lastexit; p = NEXT_INSN (p)) | |
b1f21e0a | 2512 | if (REGNO_LAST_UID (REGNO (reg)) == INSN_UID (p)) |
15a63be1 RK |
2513 | break; |
2514 | ||
2515 | if (p != lastexit) | |
2516 | { | |
2517 | /* We can do the replacement. Allocate reg_map if this is the | |
2518 | first replacement we found. */ | |
2519 | if (reg_map == 0) | |
2520 | { | |
2521 | reg_map = (rtx *) alloca (max_reg * sizeof (rtx)); | |
4c9a05bc | 2522 | bzero ((char *) reg_map, max_reg * sizeof (rtx)); |
15a63be1 RK |
2523 | } |
2524 | ||
e33477be | 2525 | REG_LOOP_TEST_P (reg) = 1; |
15a63be1 | 2526 | |
e33477be | 2527 | reg_map[REGNO (reg)] = gen_reg_rtx (GET_MODE (reg)); |
15a63be1 RK |
2528 | } |
2529 | } | |
2530 | ||
2531 | /* Now copy each insn. */ | |
2532 | for (insn = exitcode; insn != lastexit; insn = NEXT_INSN (insn)) | |
2533 | switch (GET_CODE (insn)) | |
2534 | { | |
2535 | case BARRIER: | |
2536 | copy = emit_barrier_before (loop_start); | |
2537 | break; | |
2538 | case NOTE: | |
2539 | /* Only copy line-number notes. */ | |
2540 | if (NOTE_LINE_NUMBER (insn) >= 0) | |
2541 | { | |
2542 | copy = emit_note_before (NOTE_LINE_NUMBER (insn), loop_start); | |
2543 | NOTE_SOURCE_FILE (copy) = NOTE_SOURCE_FILE (insn); | |
2544 | } | |
2545 | break; | |
2546 | ||
2547 | case INSN: | |
2548 | copy = emit_insn_before (copy_rtx (PATTERN (insn)), loop_start); | |
2549 | if (reg_map) | |
2550 | replace_regs (PATTERN (copy), reg_map, max_reg, 1); | |
2551 | ||
2552 | mark_jump_label (PATTERN (copy), copy, 0); | |
2553 | ||
2554 | /* Copy all REG_NOTES except REG_LABEL since mark_jump_label will | |
2555 | make them. */ | |
2556 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
2557 | if (REG_NOTE_KIND (link) != REG_LABEL) | |
2558 | REG_NOTES (copy) | |
38a448ca RH |
2559 | = copy_rtx (gen_rtx_EXPR_LIST (REG_NOTE_KIND (link), |
2560 | XEXP (link, 0), | |
2561 | REG_NOTES (copy))); | |
15a63be1 RK |
2562 | if (reg_map && REG_NOTES (copy)) |
2563 | replace_regs (REG_NOTES (copy), reg_map, max_reg, 1); | |
2564 | break; | |
2565 | ||
2566 | case JUMP_INSN: | |
2567 | copy = emit_jump_insn_before (copy_rtx (PATTERN (insn)), loop_start); | |
2568 | if (reg_map) | |
2569 | replace_regs (PATTERN (copy), reg_map, max_reg, 1); | |
2570 | mark_jump_label (PATTERN (copy), copy, 0); | |
2571 | if (REG_NOTES (insn)) | |
2572 | { | |
2573 | REG_NOTES (copy) = copy_rtx (REG_NOTES (insn)); | |
2574 | if (reg_map) | |
2575 | replace_regs (REG_NOTES (copy), reg_map, max_reg, 1); | |
2576 | } | |
2577 | ||
2578 | /* If this is a simple jump, add it to the jump chain. */ | |
2579 | ||
2580 | if (INSN_UID (copy) < max_jump_chain && JUMP_LABEL (copy) | |
2581 | && simplejump_p (copy)) | |
2582 | { | |
2583 | jump_chain[INSN_UID (copy)] | |
2584 | = jump_chain[INSN_UID (JUMP_LABEL (copy))]; | |
2585 | jump_chain[INSN_UID (JUMP_LABEL (copy))] = copy; | |
2586 | } | |
2587 | break; | |
2588 | ||
2589 | default: | |
2590 | abort (); | |
2591 | } | |
2592 | ||
2593 | /* Now clean up by emitting a jump to the end label and deleting the jump | |
2594 | at the start of the loop. */ | |
9c066566 | 2595 | if (! copy || GET_CODE (copy) != BARRIER) |
15a63be1 RK |
2596 | { |
2597 | copy = emit_jump_insn_before (gen_jump (get_label_after (insn)), | |
2598 | loop_start); | |
2599 | mark_jump_label (PATTERN (copy), copy, 0); | |
2600 | if (INSN_UID (copy) < max_jump_chain | |
2601 | && INSN_UID (JUMP_LABEL (copy)) < max_jump_chain) | |
2602 | { | |
2603 | jump_chain[INSN_UID (copy)] | |
2604 | = jump_chain[INSN_UID (JUMP_LABEL (copy))]; | |
2605 | jump_chain[INSN_UID (JUMP_LABEL (copy))] = copy; | |
2606 | } | |
2607 | emit_barrier_before (loop_start); | |
2608 | } | |
2609 | ||
15a63be1 RK |
2610 | /* Mark the exit code as the virtual top of the converted loop. */ |
2611 | emit_note_before (NOTE_INSN_LOOP_VTOP, exitcode); | |
2612 | ||
cd423ead RK |
2613 | delete_insn (next_nonnote_insn (loop_start)); |
2614 | ||
15a63be1 RK |
2615 | return 1; |
2616 | } | |
2617 | \f | |
2618 | /* Move all block-beg, block-end, loop-beg, loop-cont, loop-vtop, and | |
915f619f JW |
2619 | loop-end notes between START and END out before START. Assume that |
2620 | END is not such a note. START may be such a note. Returns the value | |
2621 | of the new starting insn, which may be different if the original start | |
2622 | was such a note. */ | |
15a63be1 | 2623 | |
915f619f | 2624 | rtx |
15a63be1 RK |
2625 | squeeze_notes (start, end) |
2626 | rtx start, end; | |
2627 | { | |
2628 | rtx insn; | |
2629 | rtx next; | |
2630 | ||
2631 | for (insn = start; insn != end; insn = next) | |
2632 | { | |
2633 | next = NEXT_INSN (insn); | |
2634 | if (GET_CODE (insn) == NOTE | |
2635 | && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END | |
2636 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG | |
2637 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG | |
2638 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END | |
2639 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_CONT | |
2640 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_VTOP)) | |
2641 | { | |
915f619f JW |
2642 | if (insn == start) |
2643 | start = next; | |
2644 | else | |
2645 | { | |
2646 | rtx prev = PREV_INSN (insn); | |
2647 | PREV_INSN (insn) = PREV_INSN (start); | |
2648 | NEXT_INSN (insn) = start; | |
2649 | NEXT_INSN (PREV_INSN (insn)) = insn; | |
2650 | PREV_INSN (NEXT_INSN (insn)) = insn; | |
2651 | NEXT_INSN (prev) = next; | |
2652 | PREV_INSN (next) = prev; | |
2653 | } | |
15a63be1 RK |
2654 | } |
2655 | } | |
915f619f JW |
2656 | |
2657 | return start; | |
15a63be1 RK |
2658 | } |
2659 | \f | |
2660 | /* Compare the instructions before insn E1 with those before E2 | |
2661 | to find an opportunity for cross jumping. | |
2662 | (This means detecting identical sequences of insns followed by | |
2663 | jumps to the same place, or followed by a label and a jump | |
2664 | to that label, and replacing one with a jump to the other.) | |
2665 | ||
2666 | Assume E1 is a jump that jumps to label E2 | |
2667 | (that is not always true but it might as well be). | |
2668 | Find the longest possible equivalent sequences | |
2669 | and store the first insns of those sequences into *F1 and *F2. | |
2670 | Store zero there if no equivalent preceding instructions are found. | |
2671 | ||
2672 | We give up if we find a label in stream 1. | |
2673 | Actually we could transfer that label into stream 2. */ | |
2674 | ||
2675 | static void | |
2676 | find_cross_jump (e1, e2, minimum, f1, f2) | |
2677 | rtx e1, e2; | |
2678 | int minimum; | |
2679 | rtx *f1, *f2; | |
2680 | { | |
2681 | register rtx i1 = e1, i2 = e2; | |
2682 | register rtx p1, p2; | |
2683 | int lose = 0; | |
2684 | ||
2685 | rtx last1 = 0, last2 = 0; | |
2686 | rtx afterlast1 = 0, afterlast2 = 0; | |
15a63be1 RK |
2687 | |
2688 | *f1 = 0; | |
2689 | *f2 = 0; | |
2690 | ||
2691 | while (1) | |
2692 | { | |
2693 | i1 = prev_nonnote_insn (i1); | |
2694 | ||
2695 | i2 = PREV_INSN (i2); | |
2696 | while (i2 && (GET_CODE (i2) == NOTE || GET_CODE (i2) == CODE_LABEL)) | |
2697 | i2 = PREV_INSN (i2); | |
2698 | ||
2699 | if (i1 == 0) | |
2700 | break; | |
2701 | ||
2702 | /* Don't allow the range of insns preceding E1 or E2 | |
2703 | to include the other (E2 or E1). */ | |
2704 | if (i2 == e1 || i1 == e2) | |
2705 | break; | |
2706 | ||
2707 | /* If we will get to this code by jumping, those jumps will be | |
2708 | tensioned to go directly to the new label (before I2), | |
2709 | so this cross-jumping won't cost extra. So reduce the minimum. */ | |
2710 | if (GET_CODE (i1) == CODE_LABEL) | |
2711 | { | |
2712 | --minimum; | |
2713 | break; | |
2714 | } | |
2715 | ||
2716 | if (i2 == 0 || GET_CODE (i1) != GET_CODE (i2)) | |
2717 | break; | |
2718 | ||
2719 | p1 = PATTERN (i1); | |
2720 | p2 = PATTERN (i2); | |
2721 | ||
4d367579 DE |
2722 | /* If this is a CALL_INSN, compare register usage information. |
2723 | If we don't check this on stack register machines, the two | |
2724 | CALL_INSNs might be merged leaving reg-stack.c with mismatching | |
2725 | numbers of stack registers in the same basic block. | |
2726 | If we don't check this on machines with delay slots, a delay slot may | |
2727 | be filled that clobbers a parameter expected by the subroutine. | |
47b0bb94 | 2728 | |
4d367579 DE |
2729 | ??? We take the simple route for now and assume that if they're |
2730 | equal, they were constructed identically. */ | |
2731 | ||
2732 | if (GET_CODE (i1) == CALL_INSN | |
2733 | && ! rtx_equal_p (CALL_INSN_FUNCTION_USAGE (i1), | |
2734 | CALL_INSN_FUNCTION_USAGE (i2))) | |
2735 | lose = 1; | |
2736 | ||
2737 | #ifdef STACK_REGS | |
15a63be1 RK |
2738 | /* If cross_jump_death_matters is not 0, the insn's mode |
2739 | indicates whether or not the insn contains any stack-like | |
0f41302f | 2740 | regs. */ |
15a63be1 | 2741 | |
47b0bb94 | 2742 | if (!lose && cross_jump_death_matters && GET_MODE (i1) == QImode) |
15a63be1 RK |
2743 | { |
2744 | /* If register stack conversion has already been done, then | |
2745 | death notes must also be compared before it is certain that | |
0f41302f | 2746 | the two instruction streams match. */ |
15a63be1 RK |
2747 | |
2748 | rtx note; | |
2749 | HARD_REG_SET i1_regset, i2_regset; | |
2750 | ||
2751 | CLEAR_HARD_REG_SET (i1_regset); | |
2752 | CLEAR_HARD_REG_SET (i2_regset); | |
2753 | ||
2754 | for (note = REG_NOTES (i1); note; note = XEXP (note, 1)) | |
2755 | if (REG_NOTE_KIND (note) == REG_DEAD | |
2756 | && STACK_REG_P (XEXP (note, 0))) | |
2757 | SET_HARD_REG_BIT (i1_regset, REGNO (XEXP (note, 0))); | |
2758 | ||
2759 | for (note = REG_NOTES (i2); note; note = XEXP (note, 1)) | |
2760 | if (REG_NOTE_KIND (note) == REG_DEAD | |
2761 | && STACK_REG_P (XEXP (note, 0))) | |
2762 | SET_HARD_REG_BIT (i2_regset, REGNO (XEXP (note, 0))); | |
2763 | ||
2764 | GO_IF_HARD_REG_EQUAL (i1_regset, i2_regset, done); | |
2765 | ||
2766 | lose = 1; | |
2767 | ||
2768 | done: | |
2769 | ; | |
2770 | } | |
2771 | #endif | |
2772 | ||
44c389e4 JW |
2773 | /* Don't allow old-style asm or volatile extended asms to be accepted |
2774 | for cross jumping purposes. It is conceptually correct to allow | |
2775 | them, since cross-jumping preserves the dynamic instruction order | |
2776 | even though it is changing the static instruction order. However, | |
2777 | if an asm is being used to emit an assembler pseudo-op, such as | |
2778 | the MIPS `.set reorder' pseudo-op, then the static instruction order | |
2779 | matters and it must be preserved. */ | |
2780 | if (GET_CODE (p1) == ASM_INPUT || GET_CODE (p2) == ASM_INPUT | |
2781 | || (GET_CODE (p1) == ASM_OPERANDS && MEM_VOLATILE_P (p1)) | |
2782 | || (GET_CODE (p2) == ASM_OPERANDS && MEM_VOLATILE_P (p2))) | |
2783 | lose = 1; | |
2784 | ||
2785 | if (lose || GET_CODE (p1) != GET_CODE (p2) | |
15a63be1 RK |
2786 | || ! rtx_renumbered_equal_p (p1, p2)) |
2787 | { | |
2788 | /* The following code helps take care of G++ cleanups. */ | |
2789 | rtx equiv1; | |
2790 | rtx equiv2; | |
2791 | ||
2792 | if (!lose && GET_CODE (p1) == GET_CODE (p2) | |
5f4f0e22 CH |
2793 | && ((equiv1 = find_reg_note (i1, REG_EQUAL, NULL_RTX)) != 0 |
2794 | || (equiv1 = find_reg_note (i1, REG_EQUIV, NULL_RTX)) != 0) | |
2795 | && ((equiv2 = find_reg_note (i2, REG_EQUAL, NULL_RTX)) != 0 | |
2796 | || (equiv2 = find_reg_note (i2, REG_EQUIV, NULL_RTX)) != 0) | |
15a63be1 RK |
2797 | /* If the equivalences are not to a constant, they may |
2798 | reference pseudos that no longer exist, so we can't | |
2799 | use them. */ | |
2800 | && CONSTANT_P (XEXP (equiv1, 0)) | |
2801 | && rtx_equal_p (XEXP (equiv1, 0), XEXP (equiv2, 0))) | |
2802 | { | |
2803 | rtx s1 = single_set (i1); | |
2804 | rtx s2 = single_set (i2); | |
2805 | if (s1 != 0 && s2 != 0 | |
2806 | && rtx_renumbered_equal_p (SET_DEST (s1), SET_DEST (s2))) | |
2807 | { | |
2808 | validate_change (i1, &SET_SRC (s1), XEXP (equiv1, 0), 1); | |
2809 | validate_change (i2, &SET_SRC (s2), XEXP (equiv2, 0), 1); | |
2810 | if (! rtx_renumbered_equal_p (p1, p2)) | |
2811 | cancel_changes (0); | |
2812 | else if (apply_change_group ()) | |
2813 | goto win; | |
2814 | } | |
2815 | } | |
2816 | ||
2817 | /* Insns fail to match; cross jumping is limited to the following | |
2818 | insns. */ | |
2819 | ||
2820 | #ifdef HAVE_cc0 | |
2821 | /* Don't allow the insn after a compare to be shared by | |
2822 | cross-jumping unless the compare is also shared. | |
2823 | Here, if either of these non-matching insns is a compare, | |
2824 | exclude the following insn from possible cross-jumping. */ | |
2825 | if (sets_cc0_p (p1) || sets_cc0_p (p2)) | |
2826 | last1 = afterlast1, last2 = afterlast2, ++minimum; | |
2827 | #endif | |
2828 | ||
2829 | /* If cross-jumping here will feed a jump-around-jump | |
2830 | optimization, this jump won't cost extra, so reduce | |
2831 | the minimum. */ | |
2832 | if (GET_CODE (i1) == JUMP_INSN | |
2833 | && JUMP_LABEL (i1) | |
2834 | && prev_real_insn (JUMP_LABEL (i1)) == e1) | |
2835 | --minimum; | |
2836 | break; | |
2837 | } | |
2838 | ||
2839 | win: | |
2840 | if (GET_CODE (p1) != USE && GET_CODE (p1) != CLOBBER) | |
2841 | { | |
2842 | /* Ok, this insn is potentially includable in a cross-jump here. */ | |
2843 | afterlast1 = last1, afterlast2 = last2; | |
2844 | last1 = i1, last2 = i2, --minimum; | |
2845 | } | |
2846 | } | |
2847 | ||
15a63be1 RK |
2848 | if (minimum <= 0 && last1 != 0 && last1 != e1) |
2849 | *f1 = last1, *f2 = last2; | |
2850 | } | |
2851 | ||
2852 | static void | |
2853 | do_cross_jump (insn, newjpos, newlpos) | |
2854 | rtx insn, newjpos, newlpos; | |
2855 | { | |
2856 | /* Find an existing label at this point | |
2857 | or make a new one if there is none. */ | |
2858 | register rtx label = get_label_before (newlpos); | |
2859 | ||
2860 | /* Make the same jump insn jump to the new point. */ | |
2861 | if (GET_CODE (PATTERN (insn)) == RETURN) | |
2862 | { | |
2863 | /* Remove from jump chain of returns. */ | |
2864 | delete_from_jump_chain (insn); | |
2865 | /* Change the insn. */ | |
2866 | PATTERN (insn) = gen_jump (label); | |
2867 | INSN_CODE (insn) = -1; | |
2868 | JUMP_LABEL (insn) = label; | |
2869 | LABEL_NUSES (label)++; | |
2870 | /* Add to new the jump chain. */ | |
2871 | if (INSN_UID (label) < max_jump_chain | |
2872 | && INSN_UID (insn) < max_jump_chain) | |
2873 | { | |
2874 | jump_chain[INSN_UID (insn)] = jump_chain[INSN_UID (label)]; | |
2875 | jump_chain[INSN_UID (label)] = insn; | |
2876 | } | |
2877 | } | |
2878 | else | |
2879 | redirect_jump (insn, label); | |
2880 | ||
2881 | /* Delete the matching insns before the jump. Also, remove any REG_EQUAL | |
2882 | or REG_EQUIV note in the NEWLPOS stream that isn't also present in | |
2883 | the NEWJPOS stream. */ | |
2884 | ||
2885 | while (newjpos != insn) | |
2886 | { | |
2887 | rtx lnote; | |
2888 | ||
2889 | for (lnote = REG_NOTES (newlpos); lnote; lnote = XEXP (lnote, 1)) | |
2890 | if ((REG_NOTE_KIND (lnote) == REG_EQUAL | |
2891 | || REG_NOTE_KIND (lnote) == REG_EQUIV) | |
2892 | && ! find_reg_note (newjpos, REG_EQUAL, XEXP (lnote, 0)) | |
2893 | && ! find_reg_note (newjpos, REG_EQUIV, XEXP (lnote, 0))) | |
2894 | remove_note (newlpos, lnote); | |
2895 | ||
2896 | delete_insn (newjpos); | |
2897 | newjpos = next_real_insn (newjpos); | |
2898 | newlpos = next_real_insn (newlpos); | |
2899 | } | |
2900 | } | |
2901 | \f | |
2902 | /* Return the label before INSN, or put a new label there. */ | |
2903 | ||
2904 | rtx | |
2905 | get_label_before (insn) | |
2906 | rtx insn; | |
2907 | { | |
2908 | rtx label; | |
2909 | ||
2910 | /* Find an existing label at this point | |
2911 | or make a new one if there is none. */ | |
2912 | label = prev_nonnote_insn (insn); | |
2913 | ||
2914 | if (label == 0 || GET_CODE (label) != CODE_LABEL) | |
2915 | { | |
2916 | rtx prev = PREV_INSN (insn); | |
2917 | ||
15a63be1 RK |
2918 | label = gen_label_rtx (); |
2919 | emit_label_after (label, prev); | |
2920 | LABEL_NUSES (label) = 0; | |
2921 | } | |
2922 | return label; | |
2923 | } | |
2924 | ||
2925 | /* Return the label after INSN, or put a new label there. */ | |
2926 | ||
2927 | rtx | |
2928 | get_label_after (insn) | |
2929 | rtx insn; | |
2930 | { | |
2931 | rtx label; | |
2932 | ||
2933 | /* Find an existing label at this point | |
2934 | or make a new one if there is none. */ | |
2935 | label = next_nonnote_insn (insn); | |
2936 | ||
2937 | if (label == 0 || GET_CODE (label) != CODE_LABEL) | |
2938 | { | |
15a63be1 RK |
2939 | label = gen_label_rtx (); |
2940 | emit_label_after (label, insn); | |
2941 | LABEL_NUSES (label) = 0; | |
2942 | } | |
2943 | return label; | |
2944 | } | |
2945 | \f | |
2946 | /* Return 1 if INSN is a jump that jumps to right after TARGET | |
2947 | only on the condition that TARGET itself would drop through. | |
2948 | Assumes that TARGET is a conditional jump. */ | |
2949 | ||
2950 | static int | |
2951 | jump_back_p (insn, target) | |
2952 | rtx insn, target; | |
2953 | { | |
2954 | rtx cinsn, ctarget; | |
2955 | enum rtx_code codei, codet; | |
2956 | ||
2957 | if (simplejump_p (insn) || ! condjump_p (insn) | |
2958 | || simplejump_p (target) | |
2959 | || target != prev_real_insn (JUMP_LABEL (insn))) | |
2960 | return 0; | |
2961 | ||
2962 | cinsn = XEXP (SET_SRC (PATTERN (insn)), 0); | |
2963 | ctarget = XEXP (SET_SRC (PATTERN (target)), 0); | |
2964 | ||
2965 | codei = GET_CODE (cinsn); | |
2966 | codet = GET_CODE (ctarget); | |
2967 | ||
2968 | if (XEXP (SET_SRC (PATTERN (insn)), 1) == pc_rtx) | |
2969 | { | |
2970 | if (! can_reverse_comparison_p (cinsn, insn)) | |
2971 | return 0; | |
2972 | codei = reverse_condition (codei); | |
2973 | } | |
2974 | ||
2975 | if (XEXP (SET_SRC (PATTERN (target)), 2) == pc_rtx) | |
2976 | { | |
2977 | if (! can_reverse_comparison_p (ctarget, target)) | |
2978 | return 0; | |
2979 | codet = reverse_condition (codet); | |
2980 | } | |
2981 | ||
2982 | return (codei == codet | |
2983 | && rtx_renumbered_equal_p (XEXP (cinsn, 0), XEXP (ctarget, 0)) | |
2984 | && rtx_renumbered_equal_p (XEXP (cinsn, 1), XEXP (ctarget, 1))); | |
2985 | } | |
2986 | \f | |
2987 | /* Given a comparison, COMPARISON, inside a conditional jump insn, INSN, | |
2988 | return non-zero if it is safe to reverse this comparison. It is if our | |
2989 | floating-point is not IEEE, if this is an NE or EQ comparison, or if | |
2990 | this is known to be an integer comparison. */ | |
2991 | ||
2992 | int | |
2993 | can_reverse_comparison_p (comparison, insn) | |
2994 | rtx comparison; | |
2995 | rtx insn; | |
2996 | { | |
2997 | rtx arg0; | |
2998 | ||
2999 | /* If this is not actually a comparison, we can't reverse it. */ | |
3000 | if (GET_RTX_CLASS (GET_CODE (comparison)) != '<') | |
3001 | return 0; | |
3002 | ||
3003 | if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT | |
3004 | /* If this is an NE comparison, it is safe to reverse it to an EQ | |
3005 | comparison and vice versa, even for floating point. If no operands | |
3006 | are NaNs, the reversal is valid. If some operand is a NaN, EQ is | |
3007 | always false and NE is always true, so the reversal is also valid. */ | |
9b2e59ad | 3008 | || flag_fast_math |
15a63be1 RK |
3009 | || GET_CODE (comparison) == NE |
3010 | || GET_CODE (comparison) == EQ) | |
3011 | return 1; | |
3012 | ||
3013 | arg0 = XEXP (comparison, 0); | |
3014 | ||
3015 | /* Make sure ARG0 is one of the actual objects being compared. If we | |
3016 | can't do this, we can't be sure the comparison can be reversed. | |
3017 | ||
3018 | Handle cc0 and a MODE_CC register. */ | |
3019 | if ((GET_CODE (arg0) == REG && GET_MODE_CLASS (GET_MODE (arg0)) == MODE_CC) | |
3020 | #ifdef HAVE_cc0 | |
3021 | || arg0 == cc0_rtx | |
3022 | #endif | |
3023 | ) | |
3024 | { | |
3025 | rtx prev = prev_nonnote_insn (insn); | |
3026 | rtx set = single_set (prev); | |
3027 | ||
3028 | if (set == 0 || SET_DEST (set) != arg0) | |
3029 | return 0; | |
3030 | ||
3031 | arg0 = SET_SRC (set); | |
3032 | ||
3033 | if (GET_CODE (arg0) == COMPARE) | |
3034 | arg0 = XEXP (arg0, 0); | |
3035 | } | |
3036 | ||
3037 | /* We can reverse this if ARG0 is a CONST_INT or if its mode is | |
3038 | not VOIDmode and neither a MODE_CC nor MODE_FLOAT type. */ | |
3039 | return (GET_CODE (arg0) == CONST_INT | |
3040 | || (GET_MODE (arg0) != VOIDmode | |
3041 | && GET_MODE_CLASS (GET_MODE (arg0)) != MODE_CC | |
3042 | && GET_MODE_CLASS (GET_MODE (arg0)) != MODE_FLOAT)); | |
3043 | } | |
3044 | ||
3045 | /* Given an rtx-code for a comparison, return the code | |
3046 | for the negated comparison. | |
3047 | WATCH OUT! reverse_condition is not safe to use on a jump | |
3048 | that might be acting on the results of an IEEE floating point comparison, | |
3049 | because of the special treatment of non-signaling nans in comparisons. | |
3050 | Use can_reverse_comparison_p to be sure. */ | |
3051 | ||
3052 | enum rtx_code | |
3053 | reverse_condition (code) | |
3054 | enum rtx_code code; | |
3055 | { | |
3056 | switch (code) | |
3057 | { | |
3058 | case EQ: | |
3059 | return NE; | |
3060 | ||
3061 | case NE: | |
3062 | return EQ; | |
3063 | ||
3064 | case GT: | |
3065 | return LE; | |
3066 | ||
3067 | case GE: | |
3068 | return LT; | |
3069 | ||
3070 | case LT: | |
3071 | return GE; | |
3072 | ||
3073 | case LE: | |
3074 | return GT; | |
3075 | ||
3076 | case GTU: | |
3077 | return LEU; | |
3078 | ||
3079 | case GEU: | |
3080 | return LTU; | |
3081 | ||
3082 | case LTU: | |
3083 | return GEU; | |
3084 | ||
3085 | case LEU: | |
3086 | return GTU; | |
3087 | ||
3088 | default: | |
3089 | abort (); | |
3090 | return UNKNOWN; | |
3091 | } | |
3092 | } | |
3093 | ||
3094 | /* Similar, but return the code when two operands of a comparison are swapped. | |
3095 | This IS safe for IEEE floating-point. */ | |
3096 | ||
3097 | enum rtx_code | |
3098 | swap_condition (code) | |
3099 | enum rtx_code code; | |
3100 | { | |
3101 | switch (code) | |
3102 | { | |
3103 | case EQ: | |
3104 | case NE: | |
3105 | return code; | |
3106 | ||
3107 | case GT: | |
3108 | return LT; | |
3109 | ||
3110 | case GE: | |
3111 | return LE; | |
3112 | ||
3113 | case LT: | |
3114 | return GT; | |
3115 | ||
3116 | case LE: | |
3117 | return GE; | |
3118 | ||
3119 | case GTU: | |
3120 | return LTU; | |
3121 | ||
3122 | case GEU: | |
3123 | return LEU; | |
3124 | ||
3125 | case LTU: | |
3126 | return GTU; | |
3127 | ||
3128 | case LEU: | |
3129 | return GEU; | |
3130 | ||
3131 | default: | |
3132 | abort (); | |
3133 | return UNKNOWN; | |
3134 | } | |
3135 | } | |
3136 | ||
3137 | /* Given a comparison CODE, return the corresponding unsigned comparison. | |
3138 | If CODE is an equality comparison or already an unsigned comparison, | |
3139 | CODE is returned. */ | |
3140 | ||
3141 | enum rtx_code | |
3142 | unsigned_condition (code) | |
3143 | enum rtx_code code; | |
3144 | { | |
3145 | switch (code) | |
3146 | { | |
3147 | case EQ: | |
3148 | case NE: | |
3149 | case GTU: | |
3150 | case GEU: | |
3151 | case LTU: | |
3152 | case LEU: | |
3153 | return code; | |
3154 | ||
3155 | case GT: | |
3156 | return GTU; | |
3157 | ||
3158 | case GE: | |
3159 | return GEU; | |
3160 | ||
3161 | case LT: | |
3162 | return LTU; | |
3163 | ||
3164 | case LE: | |
3165 | return LEU; | |
3166 | ||
3167 | default: | |
3168 | abort (); | |
3169 | } | |
3170 | } | |
3171 | ||
3172 | /* Similarly, return the signed version of a comparison. */ | |
3173 | ||
3174 | enum rtx_code | |
3175 | signed_condition (code) | |
3176 | enum rtx_code code; | |
3177 | { | |
3178 | switch (code) | |
3179 | { | |
3180 | case EQ: | |
3181 | case NE: | |
3182 | case GT: | |
3183 | case GE: | |
3184 | case LT: | |
3185 | case LE: | |
3186 | return code; | |
3187 | ||
3188 | case GTU: | |
3189 | return GT; | |
3190 | ||
3191 | case GEU: | |
3192 | return GE; | |
3193 | ||
3194 | case LTU: | |
3195 | return LT; | |
3196 | ||
3197 | case LEU: | |
3198 | return LE; | |
3199 | ||
3200 | default: | |
3201 | abort (); | |
3202 | } | |
3203 | } | |
3204 | \f | |
3205 | /* Return non-zero if CODE1 is more strict than CODE2, i.e., if the | |
3206 | truth of CODE1 implies the truth of CODE2. */ | |
3207 | ||
3208 | int | |
3209 | comparison_dominates_p (code1, code2) | |
3210 | enum rtx_code code1, code2; | |
3211 | { | |
3212 | if (code1 == code2) | |
3213 | return 1; | |
3214 | ||
3215 | switch (code1) | |
3216 | { | |
3217 | case EQ: | |
3218 | if (code2 == LE || code2 == LEU || code2 == GE || code2 == GEU) | |
3219 | return 1; | |
3220 | break; | |
3221 | ||
3222 | case LT: | |
b0c38416 | 3223 | if (code2 == LE || code2 == NE) |
15a63be1 RK |
3224 | return 1; |
3225 | break; | |
3226 | ||
3227 | case GT: | |
b0c38416 | 3228 | if (code2 == GE || code2 == NE) |
15a63be1 RK |
3229 | return 1; |
3230 | break; | |
3231 | ||
3232 | case LTU: | |
b0c38416 | 3233 | if (code2 == LEU || code2 == NE) |
15a63be1 RK |
3234 | return 1; |
3235 | break; | |
3236 | ||
3237 | case GTU: | |
b0c38416 | 3238 | if (code2 == GEU || code2 == NE) |
15a63be1 RK |
3239 | return 1; |
3240 | break; | |
e9a25f70 JL |
3241 | |
3242 | default: | |
3243 | break; | |
15a63be1 RK |
3244 | } |
3245 | ||
3246 | return 0; | |
3247 | } | |
3248 | \f | |
3249 | /* Return 1 if INSN is an unconditional jump and nothing else. */ | |
3250 | ||
3251 | int | |
3252 | simplejump_p (insn) | |
3253 | rtx insn; | |
3254 | { | |
3255 | return (GET_CODE (insn) == JUMP_INSN | |
3256 | && GET_CODE (PATTERN (insn)) == SET | |
3257 | && GET_CODE (SET_DEST (PATTERN (insn))) == PC | |
3258 | && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF); | |
3259 | } | |
3260 | ||
3261 | /* Return nonzero if INSN is a (possibly) conditional jump | |
3262 | and nothing more. */ | |
3263 | ||
3264 | int | |
3265 | condjump_p (insn) | |
3266 | rtx insn; | |
3267 | { | |
3268 | register rtx x = PATTERN (insn); | |
3480bb98 JL |
3269 | if (GET_CODE (x) != SET) |
3270 | return 0; | |
3271 | if (GET_CODE (SET_DEST (x)) != PC) | |
3272 | return 0; | |
3273 | if (GET_CODE (SET_SRC (x)) == LABEL_REF) | |
3274 | return 1; | |
3275 | if (GET_CODE (SET_SRC (x)) != IF_THEN_ELSE) | |
3276 | return 0; | |
3277 | if (XEXP (SET_SRC (x), 2) == pc_rtx | |
3278 | && (GET_CODE (XEXP (SET_SRC (x), 1)) == LABEL_REF | |
3279 | || GET_CODE (XEXP (SET_SRC (x), 1)) == RETURN)) | |
3280 | return 1; | |
3281 | if (XEXP (SET_SRC (x), 1) == pc_rtx | |
3282 | && (GET_CODE (XEXP (SET_SRC (x), 2)) == LABEL_REF | |
3283 | || GET_CODE (XEXP (SET_SRC (x), 2)) == RETURN)) | |
3284 | return 1; | |
3285 | return 0; | |
3286 | } | |
3287 | ||
3288 | /* Return nonzero if INSN is a (possibly) conditional jump | |
3289 | and nothing more. */ | |
3290 | ||
3291 | int | |
3292 | condjump_in_parallel_p (insn) | |
3293 | rtx insn; | |
3294 | { | |
3295 | register rtx x = PATTERN (insn); | |
3296 | ||
3297 | if (GET_CODE (x) != PARALLEL) | |
3298 | return 0; | |
3299 | else | |
3300 | x = XVECEXP (x, 0, 0); | |
3301 | ||
15a63be1 RK |
3302 | if (GET_CODE (x) != SET) |
3303 | return 0; | |
3304 | if (GET_CODE (SET_DEST (x)) != PC) | |
3305 | return 0; | |
3306 | if (GET_CODE (SET_SRC (x)) == LABEL_REF) | |
3307 | return 1; | |
3308 | if (GET_CODE (SET_SRC (x)) != IF_THEN_ELSE) | |
3309 | return 0; | |
3310 | if (XEXP (SET_SRC (x), 2) == pc_rtx | |
3311 | && (GET_CODE (XEXP (SET_SRC (x), 1)) == LABEL_REF | |
3312 | || GET_CODE (XEXP (SET_SRC (x), 1)) == RETURN)) | |
3313 | return 1; | |
3314 | if (XEXP (SET_SRC (x), 1) == pc_rtx | |
3315 | && (GET_CODE (XEXP (SET_SRC (x), 2)) == LABEL_REF | |
3316 | || GET_CODE (XEXP (SET_SRC (x), 2)) == RETURN)) | |
3317 | return 1; | |
3318 | return 0; | |
3319 | } | |
3320 | ||
3321 | /* Return 1 if X is an RTX that does nothing but set the condition codes | |
3322 | and CLOBBER or USE registers. | |
3323 | Return -1 if X does explicitly set the condition codes, | |
3324 | but also does other things. */ | |
3325 | ||
3326 | int | |
3327 | sets_cc0_p (x) | |
3328 | rtx x; | |
3329 | { | |
3330 | #ifdef HAVE_cc0 | |
3331 | if (GET_CODE (x) == SET && SET_DEST (x) == cc0_rtx) | |
3332 | return 1; | |
3333 | if (GET_CODE (x) == PARALLEL) | |
3334 | { | |
3335 | int i; | |
3336 | int sets_cc0 = 0; | |
3337 | int other_things = 0; | |
3338 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
3339 | { | |
3340 | if (GET_CODE (XVECEXP (x, 0, i)) == SET | |
3341 | && SET_DEST (XVECEXP (x, 0, i)) == cc0_rtx) | |
3342 | sets_cc0 = 1; | |
3343 | else if (GET_CODE (XVECEXP (x, 0, i)) == SET) | |
3344 | other_things = 1; | |
3345 | } | |
3346 | return ! sets_cc0 ? 0 : other_things ? -1 : 1; | |
3347 | } | |
3348 | return 0; | |
3349 | #else | |
3350 | abort (); | |
3351 | #endif | |
3352 | } | |
3353 | \f | |
3354 | /* Follow any unconditional jump at LABEL; | |
3355 | return the ultimate label reached by any such chain of jumps. | |
3356 | If LABEL is not followed by a jump, return LABEL. | |
2d20b9df RS |
3357 | If the chain loops or we can't find end, return LABEL, |
3358 | since that tells caller to avoid changing the insn. | |
15a63be1 RK |
3359 | |
3360 | If RELOAD_COMPLETED is 0, we do not chain across a NOTE_INSN_LOOP_BEG or | |
3361 | a USE or CLOBBER. */ | |
3362 | ||
3363 | rtx | |
3364 | follow_jumps (label) | |
3365 | rtx label; | |
3366 | { | |
3367 | register rtx insn; | |
3368 | register rtx next; | |
3369 | register rtx value = label; | |
3370 | register int depth; | |
3371 | ||
3372 | for (depth = 0; | |
3373 | (depth < 10 | |
3374 | && (insn = next_active_insn (value)) != 0 | |
3375 | && GET_CODE (insn) == JUMP_INSN | |
a9cc9061 JL |
3376 | && ((JUMP_LABEL (insn) != 0 && simplejump_p (insn)) |
3377 | || GET_CODE (PATTERN (insn)) == RETURN) | |
15a63be1 RK |
3378 | && (next = NEXT_INSN (insn)) |
3379 | && GET_CODE (next) == BARRIER); | |
3380 | depth++) | |
3381 | { | |
3382 | /* Don't chain through the insn that jumps into a loop | |
3383 | from outside the loop, | |
3384 | since that would create multiple loop entry jumps | |
3385 | and prevent loop optimization. */ | |
3386 | rtx tem; | |
3387 | if (!reload_completed) | |
3388 | for (tem = value; tem != insn; tem = NEXT_INSN (tem)) | |
3389 | if (GET_CODE (tem) == NOTE | |
f6a6a1b3 DE |
3390 | && (NOTE_LINE_NUMBER (tem) == NOTE_INSN_LOOP_BEG |
3391 | /* ??? Optional. Disables some optimizations, but makes | |
3392 | gcov output more accurate with -O. */ | |
3393 | || (flag_test_coverage && NOTE_LINE_NUMBER (tem) > 0))) | |
15a63be1 RK |
3394 | return value; |
3395 | ||
3396 | /* If we have found a cycle, make the insn jump to itself. */ | |
3397 | if (JUMP_LABEL (insn) == label) | |
2d20b9df | 3398 | return label; |
b209b3c5 JVA |
3399 | |
3400 | tem = next_active_insn (JUMP_LABEL (insn)); | |
3401 | if (tem && (GET_CODE (PATTERN (tem)) == ADDR_VEC | |
3402 | || GET_CODE (PATTERN (tem)) == ADDR_DIFF_VEC)) | |
3403 | break; | |
3404 | ||
15a63be1 RK |
3405 | value = JUMP_LABEL (insn); |
3406 | } | |
2d20b9df RS |
3407 | if (depth == 10) |
3408 | return label; | |
15a63be1 RK |
3409 | return value; |
3410 | } | |
3411 | ||
3412 | /* Assuming that field IDX of X is a vector of label_refs, | |
3413 | replace each of them by the ultimate label reached by it. | |
3414 | Return nonzero if a change is made. | |
3415 | If IGNORE_LOOPS is 0, we do not chain across a NOTE_INSN_LOOP_BEG. */ | |
3416 | ||
3417 | static int | |
3418 | tension_vector_labels (x, idx) | |
3419 | register rtx x; | |
3420 | register int idx; | |
3421 | { | |
3422 | int changed = 0; | |
3423 | register int i; | |
3424 | for (i = XVECLEN (x, idx) - 1; i >= 0; i--) | |
3425 | { | |
3426 | register rtx olabel = XEXP (XVECEXP (x, idx, i), 0); | |
3427 | register rtx nlabel = follow_jumps (olabel); | |
3428 | if (nlabel && nlabel != olabel) | |
3429 | { | |
3430 | XEXP (XVECEXP (x, idx, i), 0) = nlabel; | |
3431 | ++LABEL_NUSES (nlabel); | |
3432 | if (--LABEL_NUSES (olabel) == 0) | |
3433 | delete_insn (olabel); | |
3434 | changed = 1; | |
3435 | } | |
3436 | } | |
3437 | return changed; | |
3438 | } | |
3439 | \f | |
3440 | /* Find all CODE_LABELs referred to in X, and increment their use counts. | |
3441 | If INSN is a JUMP_INSN and there is at least one CODE_LABEL referenced | |
3442 | in INSN, then store one of them in JUMP_LABEL (INSN). | |
3443 | If INSN is an INSN or a CALL_INSN and there is at least one CODE_LABEL | |
3444 | referenced in INSN, add a REG_LABEL note containing that label to INSN. | |
3445 | Also, when there are consecutive labels, canonicalize on the last of them. | |
3446 | ||
3447 | Note that two labels separated by a loop-beginning note | |
3448 | must be kept distinct if we have not yet done loop-optimization, | |
3449 | because the gap between them is where loop-optimize | |
3450 | will want to move invariant code to. CROSS_JUMP tells us | |
3451 | that loop-optimization is done with. | |
3452 | ||
3453 | Once reload has completed (CROSS_JUMP non-zero), we need not consider | |
3454 | two labels distinct if they are separated by only USE or CLOBBER insns. */ | |
3455 | ||
3456 | static void | |
3457 | mark_jump_label (x, insn, cross_jump) | |
3458 | register rtx x; | |
3459 | rtx insn; | |
3460 | int cross_jump; | |
3461 | { | |
3462 | register RTX_CODE code = GET_CODE (x); | |
3463 | register int i; | |
3464 | register char *fmt; | |
3465 | ||
3466 | switch (code) | |
3467 | { | |
3468 | case PC: | |
3469 | case CC0: | |
3470 | case REG: | |
3471 | case SUBREG: | |
3472 | case CONST_INT: | |
3473 | case SYMBOL_REF: | |
3474 | case CONST_DOUBLE: | |
3475 | case CLOBBER: | |
3476 | case CALL: | |
3477 | return; | |
3478 | ||
d7ea4cf6 RK |
3479 | case MEM: |
3480 | /* If this is a constant-pool reference, see if it is a label. */ | |
3481 | if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF | |
3482 | && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0))) | |
3483 | mark_jump_label (get_pool_constant (XEXP (x, 0)), insn, cross_jump); | |
3484 | break; | |
3485 | ||
15a63be1 RK |
3486 | case LABEL_REF: |
3487 | { | |
5c5e36c5 RK |
3488 | rtx label = XEXP (x, 0); |
3489 | rtx olabel = label; | |
3490 | rtx note; | |
3491 | rtx next; | |
3492 | ||
15a63be1 RK |
3493 | if (GET_CODE (label) != CODE_LABEL) |
3494 | abort (); | |
5c5e36c5 | 3495 | |
705f26cf RS |
3496 | /* Ignore references to labels of containing functions. */ |
3497 | if (LABEL_REF_NONLOCAL_P (x)) | |
3498 | break; | |
5c5e36c5 | 3499 | |
15a63be1 RK |
3500 | /* If there are other labels following this one, |
3501 | replace it with the last of the consecutive labels. */ | |
3502 | for (next = NEXT_INSN (label); next; next = NEXT_INSN (next)) | |
3503 | { | |
3504 | if (GET_CODE (next) == CODE_LABEL) | |
3505 | label = next; | |
3506 | else if (cross_jump && GET_CODE (next) == INSN | |
3507 | && (GET_CODE (PATTERN (next)) == USE | |
3508 | || GET_CODE (PATTERN (next)) == CLOBBER)) | |
3509 | continue; | |
3510 | else if (GET_CODE (next) != NOTE) | |
3511 | break; | |
3512 | else if (! cross_jump | |
3513 | && (NOTE_LINE_NUMBER (next) == NOTE_INSN_LOOP_BEG | |
f6a6a1b3 DE |
3514 | || NOTE_LINE_NUMBER (next) == NOTE_INSN_FUNCTION_END |
3515 | /* ??? Optional. Disables some optimizations, but | |
3516 | makes gcov output more accurate with -O. */ | |
3517 | || (flag_test_coverage && NOTE_LINE_NUMBER (next) > 0))) | |
15a63be1 RK |
3518 | break; |
3519 | } | |
5c5e36c5 | 3520 | |
15a63be1 | 3521 | XEXP (x, 0) = label; |
ac9b3c97 R |
3522 | if (! insn || ! INSN_DELETED_P (insn)) |
3523 | ++LABEL_NUSES (label); | |
5c5e36c5 | 3524 | |
15a63be1 RK |
3525 | if (insn) |
3526 | { | |
3527 | if (GET_CODE (insn) == JUMP_INSN) | |
3528 | JUMP_LABEL (insn) = label; | |
5c5e36c5 RK |
3529 | |
3530 | /* If we've changed OLABEL and we had a REG_LABEL note | |
3531 | for it, update it as well. */ | |
3532 | else if (label != olabel | |
3533 | && (note = find_reg_note (insn, REG_LABEL, olabel)) != 0) | |
3534 | XEXP (note, 0) = label; | |
3535 | ||
3536 | /* Otherwise, add a REG_LABEL note for LABEL unless there already | |
3537 | is one. */ | |
0e690bdb | 3538 | else if (! find_reg_note (insn, REG_LABEL, label)) |
15a63be1 | 3539 | { |
e105f02c JL |
3540 | /* This code used to ignore labels which refered to dispatch |
3541 | tables to avoid flow.c generating worse code. | |
3542 | ||
3543 | However, in the presense of global optimizations like | |
3544 | gcse which call find_basic_blocks without calling | |
3545 | life_analysis, not recording such labels will lead | |
3546 | to compiler aborts because of inconsistencies in the | |
3547 | flow graph. So we go ahead and record the label. | |
3548 | ||
3549 | It may also be the case that the optimization argument | |
3550 | is no longer valid because of the more accurate cfg | |
3551 | we build in find_basic_blocks -- it no longer pessimizes | |
3552 | code when it finds a REG_LABEL note. */ | |
3553 | REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_LABEL, label, | |
3554 | REG_NOTES (insn)); | |
15a63be1 RK |
3555 | } |
3556 | } | |
3557 | return; | |
3558 | } | |
3559 | ||
3560 | /* Do walk the labels in a vector, but not the first operand of an | |
3561 | ADDR_DIFF_VEC. Don't set the JUMP_LABEL of a vector. */ | |
3562 | case ADDR_VEC: | |
3563 | case ADDR_DIFF_VEC: | |
ac9b3c97 R |
3564 | if (! INSN_DELETED_P (insn)) |
3565 | { | |
3566 | int eltnum = code == ADDR_DIFF_VEC ? 1 : 0; | |
15a63be1 | 3567 | |
ac9b3c97 R |
3568 | for (i = 0; i < XVECLEN (x, eltnum); i++) |
3569 | mark_jump_label (XVECEXP (x, eltnum, i), NULL_RTX, cross_jump); | |
3570 | } | |
e9a25f70 JL |
3571 | return; |
3572 | ||
3573 | default: | |
3574 | break; | |
15a63be1 RK |
3575 | } |
3576 | ||
3577 | fmt = GET_RTX_FORMAT (code); | |
3578 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
3579 | { | |
3580 | if (fmt[i] == 'e') | |
3581 | mark_jump_label (XEXP (x, i), insn, cross_jump); | |
3582 | else if (fmt[i] == 'E') | |
3583 | { | |
3584 | register int j; | |
3585 | for (j = 0; j < XVECLEN (x, i); j++) | |
3586 | mark_jump_label (XVECEXP (x, i, j), insn, cross_jump); | |
3587 | } | |
3588 | } | |
3589 | } | |
3590 | ||
3591 | /* If all INSN does is set the pc, delete it, | |
3592 | and delete the insn that set the condition codes for it | |
3593 | if that's what the previous thing was. */ | |
3594 | ||
3595 | void | |
3596 | delete_jump (insn) | |
3597 | rtx insn; | |
3598 | { | |
3e5478ea RK |
3599 | register rtx set = single_set (insn); |
3600 | ||
3601 | if (set && GET_CODE (SET_DEST (set)) == PC) | |
3602 | delete_computation (insn); | |
3603 | } | |
3604 | ||
3605 | /* Delete INSN and recursively delete insns that compute values used only | |
3606 | by INSN. This uses the REG_DEAD notes computed during flow analysis. | |
3607 | If we are running before flow.c, we need do nothing since flow.c will | |
3608 | delete dead code. We also can't know if the registers being used are | |
3609 | dead or not at this point. | |
3610 | ||
3611 | Otherwise, look at all our REG_DEAD notes. If a previous insn does | |
3612 | nothing other than set a register that dies in this insn, we can delete | |
3613 | that insn as well. | |
3614 | ||
3615 | On machines with CC0, if CC0 is used in this insn, we may be able to | |
3616 | delete the insn that set it. */ | |
3617 | ||
8cd2aff2 | 3618 | static void |
3e5478ea RK |
3619 | delete_computation (insn) |
3620 | rtx insn; | |
3621 | { | |
3622 | rtx note, next; | |
15a63be1 | 3623 | |
15a63be1 | 3624 | #ifdef HAVE_cc0 |
2fb95912 | 3625 | if (reg_referenced_p (cc0_rtx, PATTERN (insn))) |
3e5478ea | 3626 | { |
77472c5a | 3627 | rtx prev = prev_nonnote_insn (insn); |
15a63be1 RK |
3628 | /* We assume that at this stage |
3629 | CC's are always set explicitly | |
3630 | and always immediately before the jump that | |
3631 | will use them. So if the previous insn | |
3632 | exists to set the CC's, delete it | |
3633 | (unless it performs auto-increments, etc.). */ | |
3634 | if (prev && GET_CODE (prev) == INSN | |
3635 | && sets_cc0_p (PATTERN (prev))) | |
3636 | { | |
3637 | if (sets_cc0_p (PATTERN (prev)) > 0 | |
5f4f0e22 | 3638 | && !FIND_REG_INC_NOTE (prev, NULL_RTX)) |
3e5478ea | 3639 | delete_computation (prev); |
15a63be1 RK |
3640 | else |
3641 | /* Otherwise, show that cc0 won't be used. */ | |
38a448ca RH |
3642 | REG_NOTES (prev) = gen_rtx_EXPR_LIST (REG_UNUSED, |
3643 | cc0_rtx, REG_NOTES (prev)); | |
15a63be1 | 3644 | } |
77472c5a | 3645 | } |
3e5478ea | 3646 | #endif |
15a63be1 | 3647 | |
77472c5a TW |
3648 | for (note = REG_NOTES (insn); note; note = next) |
3649 | { | |
3650 | rtx our_prev; | |
15a63be1 | 3651 | |
77472c5a | 3652 | next = XEXP (note, 1); |
15a63be1 | 3653 | |
77472c5a TW |
3654 | if (REG_NOTE_KIND (note) != REG_DEAD |
3655 | /* Verify that the REG_NOTE is legitimate. */ | |
3656 | || GET_CODE (XEXP (note, 0)) != REG) | |
3657 | continue; | |
15a63be1 | 3658 | |
77472c5a TW |
3659 | for (our_prev = prev_nonnote_insn (insn); |
3660 | our_prev && GET_CODE (our_prev) == INSN; | |
3661 | our_prev = prev_nonnote_insn (our_prev)) | |
3662 | { | |
3663 | /* If we reach a SEQUENCE, it is too complex to try to | |
3664 | do anything with it, so give up. */ | |
3665 | if (GET_CODE (PATTERN (our_prev)) == SEQUENCE) | |
3666 | break; | |
15a63be1 | 3667 | |
77472c5a TW |
3668 | if (GET_CODE (PATTERN (our_prev)) == USE |
3669 | && GET_CODE (XEXP (PATTERN (our_prev), 0)) == INSN) | |
3670 | /* reorg creates USEs that look like this. We leave them | |
3671 | alone because reorg needs them for its own purposes. */ | |
3672 | break; | |
15a63be1 | 3673 | |
77472c5a TW |
3674 | if (reg_set_p (XEXP (note, 0), PATTERN (our_prev))) |
3675 | { | |
3676 | if (FIND_REG_INC_NOTE (our_prev, NULL_RTX)) | |
3677 | break; | |
15a63be1 | 3678 | |
77472c5a TW |
3679 | if (GET_CODE (PATTERN (our_prev)) == PARALLEL) |
3680 | { | |
3681 | /* If we find a SET of something else, we can't | |
3682 | delete the insn. */ | |
15a63be1 | 3683 | |
77472c5a | 3684 | int i; |
15a63be1 | 3685 | |
77472c5a TW |
3686 | for (i = 0; i < XVECLEN (PATTERN (our_prev), 0); i++) |
3687 | { | |
3688 | rtx part = XVECEXP (PATTERN (our_prev), 0, i); | |
15a63be1 | 3689 | |
77472c5a TW |
3690 | if (GET_CODE (part) == SET |
3691 | && SET_DEST (part) != XEXP (note, 0)) | |
3692 | break; | |
3693 | } | |
15a63be1 | 3694 | |
77472c5a TW |
3695 | if (i == XVECLEN (PATTERN (our_prev), 0)) |
3696 | delete_computation (our_prev); | |
3697 | } | |
3698 | else if (GET_CODE (PATTERN (our_prev)) == SET | |
3699 | && SET_DEST (PATTERN (our_prev)) == XEXP (note, 0)) | |
3700 | delete_computation (our_prev); | |
3701 | ||
3702 | break; | |
3703 | } | |
3704 | ||
3705 | /* If OUR_PREV references the register that dies here, it is an | |
3706 | additional use. Hence any prior SET isn't dead. However, this | |
3707 | insn becomes the new place for the REG_DEAD note. */ | |
3708 | if (reg_overlap_mentioned_p (XEXP (note, 0), | |
3709 | PATTERN (our_prev))) | |
3710 | { | |
3711 | XEXP (note, 1) = REG_NOTES (our_prev); | |
3712 | REG_NOTES (our_prev) = note; | |
3713 | break; | |
3714 | } | |
3715 | } | |
15a63be1 | 3716 | } |
3e5478ea | 3717 | |
77472c5a | 3718 | delete_insn (insn); |
15a63be1 RK |
3719 | } |
3720 | \f | |
3721 | /* Delete insn INSN from the chain of insns and update label ref counts. | |
3722 | May delete some following insns as a consequence; may even delete | |
3723 | a label elsewhere and insns that follow it. | |
3724 | ||
3725 | Returns the first insn after INSN that was not deleted. */ | |
3726 | ||
3727 | rtx | |
3728 | delete_insn (insn) | |
3729 | register rtx insn; | |
3730 | { | |
3731 | register rtx next = NEXT_INSN (insn); | |
3732 | register rtx prev = PREV_INSN (insn); | |
196cedd0 RS |
3733 | register int was_code_label = (GET_CODE (insn) == CODE_LABEL); |
3734 | register int dont_really_delete = 0; | |
15a63be1 RK |
3735 | |
3736 | while (next && INSN_DELETED_P (next)) | |
3737 | next = NEXT_INSN (next); | |
3738 | ||
3739 | /* This insn is already deleted => return first following nondeleted. */ | |
3740 | if (INSN_DELETED_P (insn)) | |
3741 | return next; | |
3742 | ||
196cedd0 RS |
3743 | /* Don't delete user-declared labels. Convert them to special NOTEs |
3744 | instead. */ | |
9571f079 RK |
3745 | if (was_code_label && LABEL_NAME (insn) != 0 |
3746 | && optimize && ! dont_really_delete) | |
196cedd0 RS |
3747 | { |
3748 | PUT_CODE (insn, NOTE); | |
3749 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED_LABEL; | |
3750 | NOTE_SOURCE_FILE (insn) = 0; | |
3751 | dont_really_delete = 1; | |
3752 | } | |
3753 | else | |
3754 | /* Mark this insn as deleted. */ | |
3755 | INSN_DELETED_P (insn) = 1; | |
15a63be1 RK |
3756 | |
3757 | /* If this is an unconditional jump, delete it from the jump chain. */ | |
3758 | if (simplejump_p (insn)) | |
3759 | delete_from_jump_chain (insn); | |
3760 | ||
3761 | /* If instruction is followed by a barrier, | |
3762 | delete the barrier too. */ | |
3763 | ||
3764 | if (next != 0 && GET_CODE (next) == BARRIER) | |
3765 | { | |
3766 | INSN_DELETED_P (next) = 1; | |
3767 | next = NEXT_INSN (next); | |
3768 | } | |
3769 | ||
3770 | /* Patch out INSN (and the barrier if any) */ | |
3771 | ||
196cedd0 | 3772 | if (optimize && ! dont_really_delete) |
15a63be1 RK |
3773 | { |
3774 | if (prev) | |
3775 | { | |
3776 | NEXT_INSN (prev) = next; | |
3777 | if (GET_CODE (prev) == INSN && GET_CODE (PATTERN (prev)) == SEQUENCE) | |
3778 | NEXT_INSN (XVECEXP (PATTERN (prev), 0, | |
3779 | XVECLEN (PATTERN (prev), 0) - 1)) = next; | |
3780 | } | |
3781 | ||
3782 | if (next) | |
3783 | { | |
3784 | PREV_INSN (next) = prev; | |
3785 | if (GET_CODE (next) == INSN && GET_CODE (PATTERN (next)) == SEQUENCE) | |
3786 | PREV_INSN (XVECEXP (PATTERN (next), 0, 0)) = prev; | |
3787 | } | |
3788 | ||
3789 | if (prev && NEXT_INSN (prev) == 0) | |
3790 | set_last_insn (prev); | |
3791 | } | |
3792 | ||
3793 | /* If deleting a jump, decrement the count of the label, | |
3794 | and delete the label if it is now unused. */ | |
3795 | ||
3796 | if (GET_CODE (insn) == JUMP_INSN && JUMP_LABEL (insn)) | |
3797 | if (--LABEL_NUSES (JUMP_LABEL (insn)) == 0) | |
3798 | { | |
3799 | /* This can delete NEXT or PREV, | |
3800 | either directly if NEXT is JUMP_LABEL (INSN), | |
3801 | or indirectly through more levels of jumps. */ | |
3802 | delete_insn (JUMP_LABEL (insn)); | |
3803 | /* I feel a little doubtful about this loop, | |
3804 | but I see no clean and sure alternative way | |
3805 | to find the first insn after INSN that is not now deleted. | |
3806 | I hope this works. */ | |
3807 | while (next && INSN_DELETED_P (next)) | |
3808 | next = NEXT_INSN (next); | |
3809 | return next; | |
3810 | } | |
3811 | ||
3c7d7a4a DE |
3812 | /* Likewise if we're deleting a dispatch table. */ |
3813 | ||
3814 | if (GET_CODE (insn) == JUMP_INSN | |
3815 | && (GET_CODE (PATTERN (insn)) == ADDR_VEC | |
3816 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)) | |
3817 | { | |
3818 | rtx pat = PATTERN (insn); | |
3819 | int i, diff_vec_p = GET_CODE (pat) == ADDR_DIFF_VEC; | |
3820 | int len = XVECLEN (pat, diff_vec_p); | |
3821 | ||
3822 | for (i = 0; i < len; i++) | |
3823 | if (--LABEL_NUSES (XEXP (XVECEXP (pat, diff_vec_p, i), 0)) == 0) | |
3824 | delete_insn (XEXP (XVECEXP (pat, diff_vec_p, i), 0)); | |
3825 | while (next && INSN_DELETED_P (next)) | |
3826 | next = NEXT_INSN (next); | |
3827 | return next; | |
3828 | } | |
3829 | ||
15a63be1 RK |
3830 | while (prev && (INSN_DELETED_P (prev) || GET_CODE (prev) == NOTE)) |
3831 | prev = PREV_INSN (prev); | |
3832 | ||
3833 | /* If INSN was a label and a dispatch table follows it, | |
3834 | delete the dispatch table. The tablejump must have gone already. | |
3835 | It isn't useful to fall through into a table. */ | |
3836 | ||
196cedd0 | 3837 | if (was_code_label |
15a63be1 RK |
3838 | && NEXT_INSN (insn) != 0 |
3839 | && GET_CODE (NEXT_INSN (insn)) == JUMP_INSN | |
3840 | && (GET_CODE (PATTERN (NEXT_INSN (insn))) == ADDR_VEC | |
3841 | || GET_CODE (PATTERN (NEXT_INSN (insn))) == ADDR_DIFF_VEC)) | |
3842 | next = delete_insn (NEXT_INSN (insn)); | |
3843 | ||
3844 | /* If INSN was a label, delete insns following it if now unreachable. */ | |
3845 | ||
196cedd0 | 3846 | if (was_code_label && prev && GET_CODE (prev) == BARRIER) |
15a63be1 RK |
3847 | { |
3848 | register RTX_CODE code; | |
3849 | while (next != 0 | |
8cd2aff2 | 3850 | && (GET_RTX_CLASS (code = GET_CODE (next)) == 'i' |
4134d7fc | 3851 | || code == NOTE || code == BARRIER |
2e1dbf22 | 3852 | || (code == CODE_LABEL && INSN_DELETED_P (next)))) |
15a63be1 RK |
3853 | { |
3854 | if (code == NOTE | |
3855 | && NOTE_LINE_NUMBER (next) != NOTE_INSN_FUNCTION_END) | |
3856 | next = NEXT_INSN (next); | |
2e1dbf22 RS |
3857 | /* Keep going past other deleted labels to delete what follows. */ |
3858 | else if (code == CODE_LABEL && INSN_DELETED_P (next)) | |
3859 | next = NEXT_INSN (next); | |
15a63be1 RK |
3860 | else |
3861 | /* Note: if this deletes a jump, it can cause more | |
3862 | deletion of unreachable code, after a different label. | |
3863 | As long as the value from this recursive call is correct, | |
3864 | this invocation functions correctly. */ | |
3865 | next = delete_insn (next); | |
3866 | } | |
3867 | } | |
3868 | ||
3869 | return next; | |
3870 | } | |
3871 | ||
3872 | /* Advance from INSN till reaching something not deleted | |
3873 | then return that. May return INSN itself. */ | |
3874 | ||
3875 | rtx | |
3876 | next_nondeleted_insn (insn) | |
3877 | rtx insn; | |
3878 | { | |
3879 | while (INSN_DELETED_P (insn)) | |
3880 | insn = NEXT_INSN (insn); | |
3881 | return insn; | |
3882 | } | |
3883 | \f | |
3884 | /* Delete a range of insns from FROM to TO, inclusive. | |
3885 | This is for the sake of peephole optimization, so assume | |
3886 | that whatever these insns do will still be done by a new | |
3887 | peephole insn that will replace them. */ | |
3888 | ||
3889 | void | |
3890 | delete_for_peephole (from, to) | |
3891 | register rtx from, to; | |
3892 | { | |
3893 | register rtx insn = from; | |
3894 | ||
3895 | while (1) | |
3896 | { | |
3897 | register rtx next = NEXT_INSN (insn); | |
3898 | register rtx prev = PREV_INSN (insn); | |
3899 | ||
3900 | if (GET_CODE (insn) != NOTE) | |
3901 | { | |
3902 | INSN_DELETED_P (insn) = 1; | |
3903 | ||
3904 | /* Patch this insn out of the chain. */ | |
3905 | /* We don't do this all at once, because we | |
3906 | must preserve all NOTEs. */ | |
3907 | if (prev) | |
3908 | NEXT_INSN (prev) = next; | |
3909 | ||
3910 | if (next) | |
3911 | PREV_INSN (next) = prev; | |
3912 | } | |
3913 | ||
3914 | if (insn == to) | |
3915 | break; | |
3916 | insn = next; | |
3917 | } | |
3918 | ||
3919 | /* Note that if TO is an unconditional jump | |
3920 | we *do not* delete the BARRIER that follows, | |
3921 | since the peephole that replaces this sequence | |
3922 | is also an unconditional jump in that case. */ | |
3923 | } | |
3924 | \f | |
3925 | /* Invert the condition of the jump JUMP, and make it jump | |
3926 | to label NLABEL instead of where it jumps now. */ | |
3927 | ||
3928 | int | |
3929 | invert_jump (jump, nlabel) | |
3930 | rtx jump, nlabel; | |
3931 | { | |
15a63be1 RK |
3932 | /* We have to either invert the condition and change the label or |
3933 | do neither. Either operation could fail. We first try to invert | |
3934 | the jump. If that succeeds, we try changing the label. If that fails, | |
3935 | we invert the jump back to what it was. */ | |
3936 | ||
3937 | if (! invert_exp (PATTERN (jump), jump)) | |
3938 | return 0; | |
3939 | ||
3940 | if (redirect_jump (jump, nlabel)) | |
f6a6a1b3 DE |
3941 | { |
3942 | if (flag_branch_probabilities) | |
3943 | { | |
3944 | rtx note = find_reg_note (jump, REG_BR_PROB, 0); | |
3945 | ||
3946 | /* An inverted jump means that a probability taken becomes a | |
3947 | probability not taken. Subtract the branch probability from the | |
3948 | probability base to convert it back to a taken probability. | |
3949 | (We don't flip the probability on a branch that's never taken. */ | |
3950 | if (note && XINT (XEXP (note, 0), 0) >= 0) | |
3951 | XINT (XEXP (note, 0), 0) = REG_BR_PROB_BASE - XINT (XEXP (note, 0), 0); | |
3952 | } | |
3953 | ||
3954 | return 1; | |
3955 | } | |
15a63be1 RK |
3956 | |
3957 | if (! invert_exp (PATTERN (jump), jump)) | |
3958 | /* This should just be putting it back the way it was. */ | |
3959 | abort (); | |
3960 | ||
3961 | return 0; | |
3962 | } | |
3963 | ||
3964 | /* Invert the jump condition of rtx X contained in jump insn, INSN. | |
3965 | ||
3966 | Return 1 if we can do so, 0 if we cannot find a way to do so that | |
3967 | matches a pattern. */ | |
3968 | ||
4214a505 | 3969 | int |
15a63be1 RK |
3970 | invert_exp (x, insn) |
3971 | rtx x; | |
3972 | rtx insn; | |
3973 | { | |
3974 | register RTX_CODE code; | |
3975 | register int i; | |
3976 | register char *fmt; | |
3977 | ||
3978 | code = GET_CODE (x); | |
3979 | ||
3980 | if (code == IF_THEN_ELSE) | |
3981 | { | |
3982 | register rtx comp = XEXP (x, 0); | |
3983 | register rtx tem; | |
3984 | ||
3985 | /* We can do this in two ways: The preferable way, which can only | |
3986 | be done if this is not an integer comparison, is to reverse | |
3987 | the comparison code. Otherwise, swap the THEN-part and ELSE-part | |
3988 | of the IF_THEN_ELSE. If we can't do either, fail. */ | |
3989 | ||
3990 | if (can_reverse_comparison_p (comp, insn) | |
3991 | && validate_change (insn, &XEXP (x, 0), | |
38a448ca RH |
3992 | gen_rtx_fmt_ee (reverse_condition (GET_CODE (comp)), |
3993 | GET_MODE (comp), XEXP (comp, 0), | |
3994 | XEXP (comp, 1)), 0)) | |
15a63be1 RK |
3995 | return 1; |
3996 | ||
3997 | tem = XEXP (x, 1); | |
3998 | validate_change (insn, &XEXP (x, 1), XEXP (x, 2), 1); | |
3999 | validate_change (insn, &XEXP (x, 2), tem, 1); | |
4000 | return apply_change_group (); | |
4001 | } | |
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 (! invert_exp (XEXP (x, i), 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 (!invert_exp (XVECEXP (x, i, j), insn)) | |
4014 | return 0; | |
4015 | } | |
4016 | } | |
4017 | ||
4018 | return 1; | |
4019 | } | |
4020 | \f | |
4021 | /* Make jump JUMP jump to label NLABEL instead of where it jumps now. | |
4022 | If the old jump target label is unused as a result, | |
4023 | it and the code following it may be deleted. | |
4024 | ||
4025 | If NLABEL is zero, we are to turn the jump into a (possibly conditional) | |
4026 | RETURN insn. | |
4027 | ||
4028 | The return value will be 1 if the change was made, 0 if it wasn't (this | |
4029 | can only occur for NLABEL == 0). */ | |
4030 | ||
4031 | int | |
4032 | redirect_jump (jump, nlabel) | |
4033 | rtx jump, nlabel; | |
4034 | { | |
4035 | register rtx olabel = JUMP_LABEL (jump); | |
4036 | ||
4037 | if (nlabel == olabel) | |
4038 | return 1; | |
4039 | ||
4040 | if (! redirect_exp (&PATTERN (jump), olabel, nlabel, jump)) | |
4041 | return 0; | |
4042 | ||
4043 | /* If this is an unconditional branch, delete it from the jump_chain of | |
4044 | OLABEL and add it to the jump_chain of NLABEL (assuming both labels | |
4045 | have UID's in range and JUMP_CHAIN is valid). */ | |
4046 | if (jump_chain && (simplejump_p (jump) | |
4047 | || GET_CODE (PATTERN (jump)) == RETURN)) | |
4048 | { | |
4049 | int label_index = nlabel ? INSN_UID (nlabel) : 0; | |
4050 | ||
4051 | delete_from_jump_chain (jump); | |
2d20b9df RS |
4052 | if (label_index < max_jump_chain |
4053 | && INSN_UID (jump) < max_jump_chain) | |
15a63be1 RK |
4054 | { |
4055 | jump_chain[INSN_UID (jump)] = jump_chain[label_index]; | |
4056 | jump_chain[label_index] = jump; | |
4057 | } | |
4058 | } | |
4059 | ||
4060 | JUMP_LABEL (jump) = nlabel; | |
4061 | if (nlabel) | |
4062 | ++LABEL_NUSES (nlabel); | |
4063 | ||
4064 | if (olabel && --LABEL_NUSES (olabel) == 0) | |
4065 | delete_insn (olabel); | |
4066 | ||
4067 | return 1; | |
4068 | } | |
4069 | ||
4070 | /* Delete the instruction JUMP from any jump chain it might be on. */ | |
4071 | ||
4072 | static void | |
4073 | delete_from_jump_chain (jump) | |
4074 | rtx jump; | |
4075 | { | |
4076 | int index; | |
4077 | rtx olabel = JUMP_LABEL (jump); | |
4078 | ||
4079 | /* Handle unconditional jumps. */ | |
4080 | if (jump_chain && olabel != 0 | |
4081 | && INSN_UID (olabel) < max_jump_chain | |
4082 | && simplejump_p (jump)) | |
4083 | index = INSN_UID (olabel); | |
4084 | /* Handle return insns. */ | |
4085 | else if (jump_chain && GET_CODE (PATTERN (jump)) == RETURN) | |
4086 | index = 0; | |
4087 | else return; | |
4088 | ||
4089 | if (jump_chain[index] == jump) | |
4090 | jump_chain[index] = jump_chain[INSN_UID (jump)]; | |
4091 | else | |
4092 | { | |
4093 | rtx insn; | |
4094 | ||
4095 | for (insn = jump_chain[index]; | |
4096 | insn != 0; | |
4097 | insn = jump_chain[INSN_UID (insn)]) | |
4098 | if (jump_chain[INSN_UID (insn)] == jump) | |
4099 | { | |
4100 | jump_chain[INSN_UID (insn)] = jump_chain[INSN_UID (jump)]; | |
4101 | break; | |
4102 | } | |
4103 | } | |
4104 | } | |
4105 | ||
4106 | /* If NLABEL is nonzero, throughout the rtx at LOC, | |
4107 | alter (LABEL_REF OLABEL) to (LABEL_REF NLABEL). If OLABEL is | |
4108 | zero, alter (RETURN) to (LABEL_REF NLABEL). | |
4109 | ||
4110 | If NLABEL is zero, alter (LABEL_REF OLABEL) to (RETURN) and check | |
4111 | validity with validate_change. Convert (set (pc) (label_ref olabel)) | |
4112 | to (return). | |
4113 | ||
4114 | Return 0 if we found a change we would like to make but it is invalid. | |
4115 | Otherwise, return 1. */ | |
4116 | ||
4214a505 | 4117 | int |
15a63be1 RK |
4118 | redirect_exp (loc, olabel, nlabel, insn) |
4119 | rtx *loc; | |
4120 | rtx olabel, nlabel; | |
4121 | rtx insn; | |
4122 | { | |
4123 | register rtx x = *loc; | |
4124 | register RTX_CODE code = GET_CODE (x); | |
4125 | register int i; | |
4126 | register char *fmt; | |
4127 | ||
4128 | if (code == LABEL_REF) | |
4129 | { | |
4130 | if (XEXP (x, 0) == olabel) | |
4131 | { | |
4132 | if (nlabel) | |
4133 | XEXP (x, 0) = nlabel; | |
4134 | else | |
38a448ca | 4135 | return validate_change (insn, loc, gen_rtx_RETURN (VOIDmode), 0); |
15a63be1 RK |
4136 | return 1; |
4137 | } | |
4138 | } | |
4139 | else if (code == RETURN && olabel == 0) | |
4140 | { | |
38a448ca | 4141 | x = gen_rtx_LABEL_REF (VOIDmode, nlabel); |
15a63be1 | 4142 | if (loc == &PATTERN (insn)) |
38a448ca | 4143 | x = gen_rtx_SET (VOIDmode, pc_rtx, x); |
15a63be1 RK |
4144 | return validate_change (insn, loc, x, 0); |
4145 | } | |
4146 | ||
4147 | if (code == SET && nlabel == 0 && SET_DEST (x) == pc_rtx | |
4148 | && GET_CODE (SET_SRC (x)) == LABEL_REF | |
4149 | && XEXP (SET_SRC (x), 0) == olabel) | |
38a448ca | 4150 | return validate_change (insn, loc, gen_rtx_RETURN (VOIDmode), 0); |
15a63be1 RK |
4151 | |
4152 | fmt = GET_RTX_FORMAT (code); | |
4153 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
4154 | { | |
4155 | if (fmt[i] == 'e') | |
4156 | if (! redirect_exp (&XEXP (x, i), olabel, nlabel, insn)) | |
4157 | return 0; | |
4158 | if (fmt[i] == 'E') | |
4159 | { | |
4160 | register int j; | |
4161 | for (j = 0; j < XVECLEN (x, i); j++) | |
4162 | if (! redirect_exp (&XVECEXP (x, i, j), olabel, nlabel, insn)) | |
4163 | return 0; | |
4164 | } | |
4165 | } | |
4166 | ||
4167 | return 1; | |
4168 | } | |
4169 | \f | |
4170 | /* Make jump JUMP jump to label NLABEL, assuming it used to be a tablejump. | |
4171 | ||
4172 | If the old jump target label (before the dispatch table) becomes unused, | |
4173 | it and the dispatch table may be deleted. In that case, find the insn | |
6dc42e49 | 4174 | before the jump references that label and delete it and logical successors |
15a63be1 RK |
4175 | too. */ |
4176 | ||
8cd2aff2 | 4177 | static void |
15a63be1 RK |
4178 | redirect_tablejump (jump, nlabel) |
4179 | rtx jump, nlabel; | |
4180 | { | |
4181 | register rtx olabel = JUMP_LABEL (jump); | |
4182 | ||
4183 | /* Add this jump to the jump_chain of NLABEL. */ | |
4184 | if (jump_chain && INSN_UID (nlabel) < max_jump_chain | |
4185 | && INSN_UID (jump) < max_jump_chain) | |
4186 | { | |
4187 | jump_chain[INSN_UID (jump)] = jump_chain[INSN_UID (nlabel)]; | |
4188 | jump_chain[INSN_UID (nlabel)] = jump; | |
4189 | } | |
4190 | ||
4191 | PATTERN (jump) = gen_jump (nlabel); | |
4192 | JUMP_LABEL (jump) = nlabel; | |
4193 | ++LABEL_NUSES (nlabel); | |
4194 | INSN_CODE (jump) = -1; | |
4195 | ||
4196 | if (--LABEL_NUSES (olabel) == 0) | |
4197 | { | |
4198 | delete_labelref_insn (jump, olabel, 0); | |
4199 | delete_insn (olabel); | |
4200 | } | |
4201 | } | |
4202 | ||
4203 | /* Find the insn referencing LABEL that is a logical predecessor of INSN. | |
4204 | If we found one, delete it and then delete this insn if DELETE_THIS is | |
4205 | non-zero. Return non-zero if INSN or a predecessor references LABEL. */ | |
4206 | ||
4207 | static int | |
4208 | delete_labelref_insn (insn, label, delete_this) | |
4209 | rtx insn, label; | |
4210 | int delete_this; | |
4211 | { | |
4212 | int deleted = 0; | |
4213 | rtx link; | |
4214 | ||
4215 | if (GET_CODE (insn) != NOTE | |
4216 | && reg_mentioned_p (label, PATTERN (insn))) | |
4217 | { | |
4218 | if (delete_this) | |
4219 | { | |
4220 | delete_insn (insn); | |
4221 | deleted = 1; | |
4222 | } | |
4223 | else | |
4224 | return 1; | |
4225 | } | |
4226 | ||
4227 | for (link = LOG_LINKS (insn); link; link = XEXP (link, 1)) | |
4228 | if (delete_labelref_insn (XEXP (link, 0), label, 1)) | |
4229 | { | |
4230 | if (delete_this) | |
4231 | { | |
4232 | delete_insn (insn); | |
4233 | deleted = 1; | |
4234 | } | |
4235 | else | |
4236 | return 1; | |
4237 | } | |
4238 | ||
4239 | return deleted; | |
4240 | } | |
4241 | \f | |
4242 | /* Like rtx_equal_p except that it considers two REGs as equal | |
4fe73cc1 RK |
4243 | if they renumber to the same value and considers two commutative |
4244 | operations to be the same if the order of the operands has been | |
8fc001f9 JL |
4245 | reversed. |
4246 | ||
4247 | ??? Addition is not commutative on the PA due to the weird implicit | |
4248 | space register selection rules for memory addresses. Therefore, we | |
4249 | don't consider a + b == b + a. | |
4250 | ||
4251 | We could/should make this test a little tighter. Possibly only | |
4252 | disabling it on the PA via some backend macro or only disabling this | |
4253 | case when the PLUS is inside a MEM. */ | |
15a63be1 RK |
4254 | |
4255 | int | |
4256 | rtx_renumbered_equal_p (x, y) | |
4257 | rtx x, y; | |
4258 | { | |
4259 | register int i; | |
4260 | register RTX_CODE code = GET_CODE (x); | |
4261 | register char *fmt; | |
4262 | ||
4263 | if (x == y) | |
4264 | return 1; | |
4fe73cc1 | 4265 | |
15a63be1 RK |
4266 | if ((code == REG || (code == SUBREG && GET_CODE (SUBREG_REG (x)) == REG)) |
4267 | && (GET_CODE (y) == REG || (GET_CODE (y) == SUBREG | |
4268 | && GET_CODE (SUBREG_REG (y)) == REG))) | |
4269 | { | |
4fe73cc1 RK |
4270 | int reg_x = -1, reg_y = -1; |
4271 | int word_x = 0, word_y = 0; | |
15a63be1 RK |
4272 | |
4273 | if (GET_MODE (x) != GET_MODE (y)) | |
4274 | return 0; | |
4275 | ||
4276 | /* If we haven't done any renumbering, don't | |
4277 | make any assumptions. */ | |
4278 | if (reg_renumber == 0) | |
4279 | return rtx_equal_p (x, y); | |
4280 | ||
4281 | if (code == SUBREG) | |
4282 | { | |
4fe73cc1 RK |
4283 | reg_x = REGNO (SUBREG_REG (x)); |
4284 | word_x = SUBREG_WORD (x); | |
4285 | ||
4286 | if (reg_renumber[reg_x] >= 0) | |
4287 | { | |
4288 | reg_x = reg_renumber[reg_x] + word_x; | |
4289 | word_x = 0; | |
4290 | } | |
15a63be1 | 4291 | } |
4fe73cc1 | 4292 | |
15a63be1 RK |
4293 | else |
4294 | { | |
4fe73cc1 RK |
4295 | reg_x = REGNO (x); |
4296 | if (reg_renumber[reg_x] >= 0) | |
4297 | reg_x = reg_renumber[reg_x]; | |
15a63be1 | 4298 | } |
4fe73cc1 | 4299 | |
15a63be1 RK |
4300 | if (GET_CODE (y) == SUBREG) |
4301 | { | |
4fe73cc1 RK |
4302 | reg_y = REGNO (SUBREG_REG (y)); |
4303 | word_y = SUBREG_WORD (y); | |
4304 | ||
4305 | if (reg_renumber[reg_y] >= 0) | |
4306 | { | |
4307 | reg_y = reg_renumber[reg_y]; | |
4308 | word_y = 0; | |
4309 | } | |
15a63be1 | 4310 | } |
4fe73cc1 | 4311 | |
15a63be1 RK |
4312 | else |
4313 | { | |
4fe73cc1 RK |
4314 | reg_y = REGNO (y); |
4315 | if (reg_renumber[reg_y] >= 0) | |
4316 | reg_y = reg_renumber[reg_y]; | |
15a63be1 | 4317 | } |
4fe73cc1 RK |
4318 | |
4319 | return reg_x >= 0 && reg_x == reg_y && word_x == word_y; | |
15a63be1 | 4320 | } |
4fe73cc1 | 4321 | |
15a63be1 RK |
4322 | /* Now we have disposed of all the cases |
4323 | in which different rtx codes can match. */ | |
4324 | if (code != GET_CODE (y)) | |
4325 | return 0; | |
4fe73cc1 | 4326 | |
15a63be1 RK |
4327 | switch (code) |
4328 | { | |
4329 | case PC: | |
4330 | case CC0: | |
4331 | case ADDR_VEC: | |
4332 | case ADDR_DIFF_VEC: | |
4333 | return 0; | |
4334 | ||
4335 | case CONST_INT: | |
38b3167e | 4336 | return INTVAL (x) == INTVAL (y); |
15a63be1 RK |
4337 | |
4338 | case LABEL_REF: | |
705f26cf RS |
4339 | /* We can't assume nonlocal labels have their following insns yet. */ |
4340 | if (LABEL_REF_NONLOCAL_P (x) || LABEL_REF_NONLOCAL_P (y)) | |
4341 | return XEXP (x, 0) == XEXP (y, 0); | |
4fe73cc1 | 4342 | |
15a63be1 RK |
4343 | /* Two label-refs are equivalent if they point at labels |
4344 | in the same position in the instruction stream. */ | |
4345 | return (next_real_insn (XEXP (x, 0)) | |
4346 | == next_real_insn (XEXP (y, 0))); | |
4347 | ||
4348 | case SYMBOL_REF: | |
4349 | return XSTR (x, 0) == XSTR (y, 0); | |
e9a25f70 JL |
4350 | |
4351 | default: | |
4352 | break; | |
15a63be1 RK |
4353 | } |
4354 | ||
4355 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. */ | |
4356 | ||
4357 | if (GET_MODE (x) != GET_MODE (y)) | |
4358 | return 0; | |
4359 | ||
4fe73cc1 | 4360 | /* For commutative operations, the RTX match if the operand match in any |
8fc001f9 JL |
4361 | order. Also handle the simple binary and unary cases without a loop. |
4362 | ||
4363 | ??? Don't consider PLUS a commutative operator; see comments above. */ | |
4364 | if ((code == EQ || code == NE || GET_RTX_CLASS (code) == 'c') | |
4365 | && code != PLUS) | |
4fe73cc1 RK |
4366 | return ((rtx_renumbered_equal_p (XEXP (x, 0), XEXP (y, 0)) |
4367 | && rtx_renumbered_equal_p (XEXP (x, 1), XEXP (y, 1))) | |
4368 | || (rtx_renumbered_equal_p (XEXP (x, 0), XEXP (y, 1)) | |
4369 | && rtx_renumbered_equal_p (XEXP (x, 1), XEXP (y, 0)))); | |
4370 | else if (GET_RTX_CLASS (code) == '<' || GET_RTX_CLASS (code) == '2') | |
4371 | return (rtx_renumbered_equal_p (XEXP (x, 0), XEXP (y, 0)) | |
4372 | && rtx_renumbered_equal_p (XEXP (x, 1), XEXP (y, 1))); | |
4373 | else if (GET_RTX_CLASS (code) == '1') | |
4374 | return rtx_renumbered_equal_p (XEXP (x, 0), XEXP (y, 0)); | |
4375 | ||
15a63be1 RK |
4376 | /* Compare the elements. If any pair of corresponding elements |
4377 | fail to match, return 0 for the whole things. */ | |
4378 | ||
4379 | fmt = GET_RTX_FORMAT (code); | |
4380 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
4381 | { | |
4382 | register int j; | |
4383 | switch (fmt[i]) | |
4384 | { | |
5f4f0e22 CH |
4385 | case 'w': |
4386 | if (XWINT (x, i) != XWINT (y, i)) | |
4387 | return 0; | |
4388 | break; | |
4389 | ||
15a63be1 RK |
4390 | case 'i': |
4391 | if (XINT (x, i) != XINT (y, i)) | |
4392 | return 0; | |
4393 | break; | |
4394 | ||
4395 | case 's': | |
4396 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
4397 | return 0; | |
4398 | break; | |
4399 | ||
4400 | case 'e': | |
4401 | if (! rtx_renumbered_equal_p (XEXP (x, i), XEXP (y, i))) | |
4402 | return 0; | |
4403 | break; | |
4404 | ||
4405 | case 'u': | |
4406 | if (XEXP (x, i) != XEXP (y, i)) | |
4407 | return 0; | |
4408 | /* fall through. */ | |
4409 | case '0': | |
4410 | break; | |
4411 | ||
4412 | case 'E': | |
4413 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
4414 | return 0; | |
4415 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
4416 | if (!rtx_renumbered_equal_p (XVECEXP (x, i, j), XVECEXP (y, i, j))) | |
4417 | return 0; | |
4418 | break; | |
4419 | ||
4420 | default: | |
4421 | abort (); | |
4422 | } | |
4423 | } | |
4424 | return 1; | |
4425 | } | |
4426 | \f | |
4427 | /* If X is a hard register or equivalent to one or a subregister of one, | |
4428 | return the hard register number. If X is a pseudo register that was not | |
4429 | assigned a hard register, return the pseudo register number. Otherwise, | |
4430 | return -1. Any rtx is valid for X. */ | |
4431 | ||
4432 | int | |
4433 | true_regnum (x) | |
4434 | rtx x; | |
4435 | { | |
4436 | if (GET_CODE (x) == REG) | |
4437 | { | |
4438 | if (REGNO (x) >= FIRST_PSEUDO_REGISTER && reg_renumber[REGNO (x)] >= 0) | |
4439 | return reg_renumber[REGNO (x)]; | |
4440 | return REGNO (x); | |
4441 | } | |
4442 | if (GET_CODE (x) == SUBREG) | |
4443 | { | |
4444 | int base = true_regnum (SUBREG_REG (x)); | |
4445 | if (base >= 0 && base < FIRST_PSEUDO_REGISTER) | |
4446 | return SUBREG_WORD (x) + base; | |
4447 | } | |
4448 | return -1; | |
4449 | } | |
4450 | \f | |
4451 | /* Optimize code of the form: | |
4452 | ||
4453 | for (x = a[i]; x; ...) | |
4454 | ... | |
4455 | for (x = a[i]; x; ...) | |
4456 | ... | |
4457 | foo: | |
4458 | ||
4459 | Loop optimize will change the above code into | |
4460 | ||
4461 | if (x = a[i]) | |
4462 | for (;;) | |
4463 | { ...; if (! (x = ...)) break; } | |
4464 | if (x = a[i]) | |
4465 | for (;;) | |
4466 | { ...; if (! (x = ...)) break; } | |
4467 | foo: | |
4468 | ||
4469 | In general, if the first test fails, the program can branch | |
4470 | directly to `foo' and skip the second try which is doomed to fail. | |
4471 | We run this after loop optimization and before flow analysis. */ | |
4472 | ||
4473 | /* When comparing the insn patterns, we track the fact that different | |
4474 | pseudo-register numbers may have been used in each computation. | |
4475 | The following array stores an equivalence -- same_regs[I] == J means | |
4476 | that pseudo register I was used in the first set of tests in a context | |
4477 | where J was used in the second set. We also count the number of such | |
4478 | pending equivalences. If nonzero, the expressions really aren't the | |
4479 | same. */ | |
4480 | ||
7ee8a9d5 | 4481 | static int *same_regs; |
15a63be1 RK |
4482 | |
4483 | static int num_same_regs; | |
4484 | ||
4485 | /* Track any registers modified between the target of the first jump and | |
4486 | the second jump. They never compare equal. */ | |
4487 | ||
4488 | static char *modified_regs; | |
4489 | ||
4490 | /* Record if memory was modified. */ | |
4491 | ||
4492 | static int modified_mem; | |
4493 | ||
4494 | /* Called via note_stores on each insn between the target of the first | |
4495 | branch and the second branch. It marks any changed registers. */ | |
4496 | ||
4497 | static void | |
4498 | mark_modified_reg (dest, x) | |
4499 | rtx dest; | |
487a6e06 | 4500 | rtx x ATTRIBUTE_UNUSED; |
15a63be1 RK |
4501 | { |
4502 | int regno, i; | |
4503 | ||
4504 | if (GET_CODE (dest) == SUBREG) | |
4505 | dest = SUBREG_REG (dest); | |
4506 | ||
4507 | if (GET_CODE (dest) == MEM) | |
4508 | modified_mem = 1; | |
4509 | ||
4510 | if (GET_CODE (dest) != REG) | |
4511 | return; | |
4512 | ||
4513 | regno = REGNO (dest); | |
4514 | if (regno >= FIRST_PSEUDO_REGISTER) | |
4515 | modified_regs[regno] = 1; | |
4516 | else | |
4517 | for (i = 0; i < HARD_REGNO_NREGS (regno, GET_MODE (dest)); i++) | |
4518 | modified_regs[regno + i] = 1; | |
4519 | } | |
4520 | ||
4521 | /* F is the first insn in the chain of insns. */ | |
4522 | ||
4523 | void | |
aa38b201 | 4524 | thread_jumps (f, max_reg, flag_before_loop) |
15a63be1 RK |
4525 | rtx f; |
4526 | int max_reg; | |
aa38b201 | 4527 | int flag_before_loop; |
15a63be1 RK |
4528 | { |
4529 | /* Basic algorithm is to find a conditional branch, | |
4530 | the label it may branch to, and the branch after | |
4531 | that label. If the two branches test the same condition, | |
4532 | walk back from both branch paths until the insn patterns | |
4533 | differ, or code labels are hit. If we make it back to | |
4534 | the target of the first branch, then we know that the first branch | |
4535 | will either always succeed or always fail depending on the relative | |
4536 | senses of the two branches. So adjust the first branch accordingly | |
4537 | in this case. */ | |
4538 | ||
4539 | rtx label, b1, b2, t1, t2; | |
4540 | enum rtx_code code1, code2; | |
4541 | rtx b1op0, b1op1, b2op0, b2op1; | |
4542 | int changed = 1; | |
4543 | int i; | |
7ee8a9d5 | 4544 | int *all_reset; |
15a63be1 RK |
4545 | |
4546 | /* Allocate register tables and quick-reset table. */ | |
4547 | modified_regs = (char *) alloca (max_reg * sizeof (char)); | |
7ee8a9d5 RK |
4548 | same_regs = (int *) alloca (max_reg * sizeof (int)); |
4549 | all_reset = (int *) alloca (max_reg * sizeof (int)); | |
15a63be1 RK |
4550 | for (i = 0; i < max_reg; i++) |
4551 | all_reset[i] = -1; | |
4552 | ||
4553 | while (changed) | |
4554 | { | |
4555 | changed = 0; | |
4556 | ||
4557 | for (b1 = f; b1; b1 = NEXT_INSN (b1)) | |
4558 | { | |
4559 | /* Get to a candidate branch insn. */ | |
4560 | if (GET_CODE (b1) != JUMP_INSN | |
4561 | || ! condjump_p (b1) || simplejump_p (b1) | |
4562 | || JUMP_LABEL (b1) == 0) | |
4563 | continue; | |
4564 | ||
4565 | bzero (modified_regs, max_reg * sizeof (char)); | |
4566 | modified_mem = 0; | |
4567 | ||
4c9a05bc RK |
4568 | bcopy ((char *) all_reset, (char *) same_regs, |
4569 | max_reg * sizeof (int)); | |
15a63be1 RK |
4570 | num_same_regs = 0; |
4571 | ||
4572 | label = JUMP_LABEL (b1); | |
4573 | ||
4574 | /* Look for a branch after the target. Record any registers and | |
4575 | memory modified between the target and the branch. Stop when we | |
4576 | get to a label since we can't know what was changed there. */ | |
4577 | for (b2 = NEXT_INSN (label); b2; b2 = NEXT_INSN (b2)) | |
4578 | { | |
4579 | if (GET_CODE (b2) == CODE_LABEL) | |
4580 | break; | |
4581 | ||
4582 | else if (GET_CODE (b2) == JUMP_INSN) | |
4583 | { | |
4584 | /* If this is an unconditional jump and is the only use of | |
4585 | its target label, we can follow it. */ | |
4586 | if (simplejump_p (b2) | |
4587 | && JUMP_LABEL (b2) != 0 | |
4588 | && LABEL_NUSES (JUMP_LABEL (b2)) == 1) | |
4589 | { | |
4590 | b2 = JUMP_LABEL (b2); | |
4591 | continue; | |
4592 | } | |
4593 | else | |
4594 | break; | |
4595 | } | |
4596 | ||
4597 | if (GET_CODE (b2) != CALL_INSN && GET_CODE (b2) != INSN) | |
4598 | continue; | |
4599 | ||
4600 | if (GET_CODE (b2) == CALL_INSN) | |
4601 | { | |
4602 | modified_mem = 1; | |
4603 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
4604 | if (call_used_regs[i] && ! fixed_regs[i] | |
4605 | && i != STACK_POINTER_REGNUM | |
4606 | && i != FRAME_POINTER_REGNUM | |
cbe23927 | 4607 | && i != HARD_FRAME_POINTER_REGNUM |
15a63be1 RK |
4608 | && i != ARG_POINTER_REGNUM) |
4609 | modified_regs[i] = 1; | |
4610 | } | |
4611 | ||
4612 | note_stores (PATTERN (b2), mark_modified_reg); | |
4613 | } | |
4614 | ||
4615 | /* Check the next candidate branch insn from the label | |
4616 | of the first. */ | |
4617 | if (b2 == 0 | |
4618 | || GET_CODE (b2) != JUMP_INSN | |
4619 | || b2 == b1 | |
4620 | || ! condjump_p (b2) | |
4621 | || simplejump_p (b2)) | |
4622 | continue; | |
4623 | ||
4624 | /* Get the comparison codes and operands, reversing the | |
4625 | codes if appropriate. If we don't have comparison codes, | |
4626 | we can't do anything. */ | |
4627 | b1op0 = XEXP (XEXP (SET_SRC (PATTERN (b1)), 0), 0); | |
4628 | b1op1 = XEXP (XEXP (SET_SRC (PATTERN (b1)), 0), 1); | |
4629 | code1 = GET_CODE (XEXP (SET_SRC (PATTERN (b1)), 0)); | |
4630 | if (XEXP (SET_SRC (PATTERN (b1)), 1) == pc_rtx) | |
4631 | code1 = reverse_condition (code1); | |
4632 | ||
4633 | b2op0 = XEXP (XEXP (SET_SRC (PATTERN (b2)), 0), 0); | |
4634 | b2op1 = XEXP (XEXP (SET_SRC (PATTERN (b2)), 0), 1); | |
4635 | code2 = GET_CODE (XEXP (SET_SRC (PATTERN (b2)), 0)); | |
4636 | if (XEXP (SET_SRC (PATTERN (b2)), 1) == pc_rtx) | |
4637 | code2 = reverse_condition (code2); | |
4638 | ||
4639 | /* If they test the same things and knowing that B1 branches | |
4640 | tells us whether or not B2 branches, check if we | |
4641 | can thread the branch. */ | |
4642 | if (rtx_equal_for_thread_p (b1op0, b2op0, b2) | |
4643 | && rtx_equal_for_thread_p (b1op1, b2op1, b2) | |
4644 | && (comparison_dominates_p (code1, code2) | |
cc5e1642 R |
4645 | || (comparison_dominates_p (code1, reverse_condition (code2)) |
4646 | && can_reverse_comparison_p (XEXP (SET_SRC (PATTERN (b1)), | |
4647 | 0), | |
4648 | b1)))) | |
15a63be1 RK |
4649 | { |
4650 | t1 = prev_nonnote_insn (b1); | |
4651 | t2 = prev_nonnote_insn (b2); | |
4652 | ||
4653 | while (t1 != 0 && t2 != 0) | |
4654 | { | |
15a63be1 RK |
4655 | if (t2 == label) |
4656 | { | |
4657 | /* We have reached the target of the first branch. | |
4658 | If there are no pending register equivalents, | |
4659 | we know that this branch will either always | |
4660 | succeed (if the senses of the two branches are | |
4661 | the same) or always fail (if not). */ | |
4662 | rtx new_label; | |
4663 | ||
4664 | if (num_same_regs != 0) | |
4665 | break; | |
4666 | ||
4667 | if (comparison_dominates_p (code1, code2)) | |
4668 | new_label = JUMP_LABEL (b2); | |
4669 | else | |
4670 | new_label = get_label_after (b2); | |
4671 | ||
aa38b201 TG |
4672 | if (JUMP_LABEL (b1) != new_label) |
4673 | { | |
4674 | rtx prev = PREV_INSN (new_label); | |
4675 | ||
4676 | if (flag_before_loop | |
c71407f9 | 4677 | && GET_CODE (prev) == NOTE |
aa38b201 TG |
4678 | && NOTE_LINE_NUMBER (prev) == NOTE_INSN_LOOP_BEG) |
4679 | { | |
4680 | /* Don't thread to the loop label. If a loop | |
4681 | label is reused, loop optimization will | |
4682 | be disabled for that loop. */ | |
4683 | new_label = gen_label_rtx (); | |
4684 | emit_label_after (new_label, PREV_INSN (prev)); | |
4685 | } | |
4686 | changed |= redirect_jump (b1, new_label); | |
4687 | } | |
15a63be1 RK |
4688 | break; |
4689 | } | |
4690 | ||
4691 | /* If either of these is not a normal insn (it might be | |
4692 | a JUMP_INSN, CALL_INSN, or CODE_LABEL) we fail. (NOTEs | |
4693 | have already been skipped above.) Similarly, fail | |
4694 | if the insns are different. */ | |
4695 | if (GET_CODE (t1) != INSN || GET_CODE (t2) != INSN | |
4696 | || recog_memoized (t1) != recog_memoized (t2) | |
4697 | || ! rtx_equal_for_thread_p (PATTERN (t1), | |
4698 | PATTERN (t2), t2)) | |
4699 | break; | |
4700 | ||
4701 | t1 = prev_nonnote_insn (t1); | |
4702 | t2 = prev_nonnote_insn (t2); | |
4703 | } | |
4704 | } | |
4705 | } | |
4706 | } | |
4707 | } | |
4708 | \f | |
4709 | /* This is like RTX_EQUAL_P except that it knows about our handling of | |
4710 | possibly equivalent registers and knows to consider volatile and | |
4711 | modified objects as not equal. | |
4712 | ||
4713 | YINSN is the insn containing Y. */ | |
4714 | ||
4715 | int | |
4716 | rtx_equal_for_thread_p (x, y, yinsn) | |
4717 | rtx x, y; | |
4718 | rtx yinsn; | |
4719 | { | |
4720 | register int i; | |
4721 | register int j; | |
4722 | register enum rtx_code code; | |
4723 | register char *fmt; | |
4724 | ||
4725 | code = GET_CODE (x); | |
4726 | /* Rtx's of different codes cannot be equal. */ | |
4727 | if (code != GET_CODE (y)) | |
4728 | return 0; | |
4729 | ||
4730 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. | |
4731 | (REG:SI x) and (REG:HI x) are NOT equivalent. */ | |
4732 | ||
4733 | if (GET_MODE (x) != GET_MODE (y)) | |
4734 | return 0; | |
4735 | ||
35d9eabb RK |
4736 | /* For floating-point, consider everything unequal. This is a bit |
4737 | pessimistic, but this pass would only rarely do anything for FP | |
4738 | anyway. */ | |
4739 | if (TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT | |
4740 | && FLOAT_MODE_P (GET_MODE (x)) && ! flag_fast_math) | |
4741 | return 0; | |
4742 | ||
413c72c2 RK |
4743 | /* For commutative operations, the RTX match if the operand match in any |
4744 | order. Also handle the simple binary and unary cases without a loop. */ | |
4745 | if (code == EQ || code == NE || GET_RTX_CLASS (code) == 'c') | |
c5ea5f3b RK |
4746 | return ((rtx_equal_for_thread_p (XEXP (x, 0), XEXP (y, 0), yinsn) |
4747 | && rtx_equal_for_thread_p (XEXP (x, 1), XEXP (y, 1), yinsn)) | |
4748 | || (rtx_equal_for_thread_p (XEXP (x, 0), XEXP (y, 1), yinsn) | |
4749 | && rtx_equal_for_thread_p (XEXP (x, 1), XEXP (y, 0), yinsn))); | |
413c72c2 | 4750 | else if (GET_RTX_CLASS (code) == '<' || GET_RTX_CLASS (code) == '2') |
c5ea5f3b RK |
4751 | return (rtx_equal_for_thread_p (XEXP (x, 0), XEXP (y, 0), yinsn) |
4752 | && rtx_equal_for_thread_p (XEXP (x, 1), XEXP (y, 1), yinsn)); | |
413c72c2 | 4753 | else if (GET_RTX_CLASS (code) == '1') |
c5ea5f3b | 4754 | return rtx_equal_for_thread_p (XEXP (x, 0), XEXP (y, 0), yinsn); |
413c72c2 | 4755 | |
15a63be1 RK |
4756 | /* Handle special-cases first. */ |
4757 | switch (code) | |
4758 | { | |
4759 | case REG: | |
4760 | if (REGNO (x) == REGNO (y) && ! modified_regs[REGNO (x)]) | |
4761 | return 1; | |
4762 | ||
4763 | /* If neither is user variable or hard register, check for possible | |
4764 | equivalence. */ | |
4765 | if (REG_USERVAR_P (x) || REG_USERVAR_P (y) | |
4766 | || REGNO (x) < FIRST_PSEUDO_REGISTER | |
4767 | || REGNO (y) < FIRST_PSEUDO_REGISTER) | |
4768 | return 0; | |
4769 | ||
4770 | if (same_regs[REGNO (x)] == -1) | |
4771 | { | |
4772 | same_regs[REGNO (x)] = REGNO (y); | |
4773 | num_same_regs++; | |
4774 | ||
4775 | /* If this is the first time we are seeing a register on the `Y' | |
4776 | side, see if it is the last use. If not, we can't thread the | |
4777 | jump, so mark it as not equivalent. */ | |
b1f21e0a | 4778 | if (REGNO_LAST_UID (REGNO (y)) != INSN_UID (yinsn)) |
15a63be1 RK |
4779 | return 0; |
4780 | ||
4781 | return 1; | |
4782 | } | |
4783 | else | |
4784 | return (same_regs[REGNO (x)] == REGNO (y)); | |
4785 | ||
4786 | break; | |
4787 | ||
4788 | case MEM: | |
6dc42e49 | 4789 | /* If memory modified or either volatile, not equivalent. |
0f41302f | 4790 | Else, check address. */ |
15a63be1 RK |
4791 | if (modified_mem || MEM_VOLATILE_P (x) || MEM_VOLATILE_P (y)) |
4792 | return 0; | |
4793 | ||
4794 | return rtx_equal_for_thread_p (XEXP (x, 0), XEXP (y, 0), yinsn); | |
4795 | ||
4796 | case ASM_INPUT: | |
4797 | if (MEM_VOLATILE_P (x) || MEM_VOLATILE_P (y)) | |
4798 | return 0; | |
4799 | ||
4800 | break; | |
4801 | ||
4802 | case SET: | |
4803 | /* Cancel a pending `same_regs' if setting equivalenced registers. | |
4804 | Then process source. */ | |
4805 | if (GET_CODE (SET_DEST (x)) == REG | |
4806 | && GET_CODE (SET_DEST (y)) == REG) | |
4807 | { | |
4808 | if (same_regs[REGNO (SET_DEST (x))] == REGNO (SET_DEST (y))) | |
4809 | { | |
4810 | same_regs[REGNO (SET_DEST (x))] = -1; | |
4811 | num_same_regs--; | |
4812 | } | |
4813 | else if (REGNO (SET_DEST (x)) != REGNO (SET_DEST (y))) | |
4814 | return 0; | |
4815 | } | |
4816 | else | |
4817 | if (rtx_equal_for_thread_p (SET_DEST (x), SET_DEST (y), yinsn) == 0) | |
4818 | return 0; | |
4819 | ||
4820 | return rtx_equal_for_thread_p (SET_SRC (x), SET_SRC (y), yinsn); | |
4821 | ||
4822 | case LABEL_REF: | |
4823 | return XEXP (x, 0) == XEXP (y, 0); | |
4824 | ||
4825 | case SYMBOL_REF: | |
4826 | return XSTR (x, 0) == XSTR (y, 0); | |
e9a25f70 JL |
4827 | |
4828 | default: | |
4829 | break; | |
15a63be1 RK |
4830 | } |
4831 | ||
4832 | if (x == y) | |
4833 | return 1; | |
4834 | ||
4835 | fmt = GET_RTX_FORMAT (code); | |
4836 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
4837 | { | |
4838 | switch (fmt[i]) | |
4839 | { | |
5f4f0e22 CH |
4840 | case 'w': |
4841 | if (XWINT (x, i) != XWINT (y, i)) | |
4842 | return 0; | |
4843 | break; | |
4844 | ||
15a63be1 RK |
4845 | case 'n': |
4846 | case 'i': | |
4847 | if (XINT (x, i) != XINT (y, i)) | |
4848 | return 0; | |
4849 | break; | |
4850 | ||
4851 | case 'V': | |
4852 | case 'E': | |
4853 | /* Two vectors must have the same length. */ | |
4854 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
4855 | return 0; | |
4856 | ||
4857 | /* And the corresponding elements must match. */ | |
4858 | for (j = 0; j < XVECLEN (x, i); j++) | |
4859 | if (rtx_equal_for_thread_p (XVECEXP (x, i, j), | |
4860 | XVECEXP (y, i, j), yinsn) == 0) | |
4861 | return 0; | |
4862 | break; | |
4863 | ||
4864 | case 'e': | |
4865 | if (rtx_equal_for_thread_p (XEXP (x, i), XEXP (y, i), yinsn) == 0) | |
4866 | return 0; | |
4867 | break; | |
4868 | ||
4869 | case 'S': | |
4870 | case 's': | |
4871 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
4872 | return 0; | |
4873 | break; | |
4874 | ||
4875 | case 'u': | |
4876 | /* These are just backpointers, so they don't matter. */ | |
4877 | break; | |
4878 | ||
4879 | case '0': | |
4880 | break; | |
4881 | ||
4882 | /* It is believed that rtx's at this level will never | |
4883 | contain anything but integers and other rtx's, | |
4884 | except for within LABEL_REFs and SYMBOL_REFs. */ | |
4885 | default: | |
4886 | abort (); | |
4887 | } | |
4888 | } | |
4889 | return 1; | |
4890 | } | |
956d6950 JL |
4891 | \f |
4892 | ||
7a87758d | 4893 | #ifndef HAVE_cc0 |
956d6950 JL |
4894 | /* Return the insn that NEW can be safely inserted in front of starting at |
4895 | the jump insn INSN. Return 0 if it is not safe to do this jump | |
4896 | optimization. Note that NEW must contain a single set. */ | |
4897 | ||
4898 | static rtx | |
4899 | find_insert_position (insn, new) | |
4900 | rtx insn; | |
4901 | rtx new; | |
4902 | { | |
4903 | int i; | |
4904 | rtx prev; | |
4905 | ||
4906 | /* If NEW does not clobber, it is safe to insert NEW before INSN. */ | |
4907 | if (GET_CODE (PATTERN (new)) != PARALLEL) | |
4908 | return insn; | |
4909 | ||
4910 | for (i = XVECLEN (PATTERN (new), 0) - 1; i >= 0; i--) | |
4911 | if (GET_CODE (XVECEXP (PATTERN (new), 0, i)) == CLOBBER | |
4912 | && reg_overlap_mentioned_p (XEXP (XVECEXP (PATTERN (new), 0, i), 0), | |
4913 | insn)) | |
4914 | break; | |
4915 | ||
4916 | if (i < 0) | |
4917 | return insn; | |
4918 | ||
4919 | /* There is a good chance that the previous insn PREV sets the thing | |
4920 | being clobbered (often the CC in a hard reg). If PREV does not | |
4921 | use what NEW sets, we can insert NEW before PREV. */ | |
4922 | ||
4923 | prev = prev_active_insn (insn); | |
4924 | for (i = XVECLEN (PATTERN (new), 0) - 1; i >= 0; i--) | |
4925 | if (GET_CODE (XVECEXP (PATTERN (new), 0, i)) == CLOBBER | |
4926 | && reg_overlap_mentioned_p (XEXP (XVECEXP (PATTERN (new), 0, i), 0), | |
4927 | insn) | |
4928 | && ! modified_in_p (XEXP (XVECEXP (PATTERN (new), 0, i), 0), | |
4929 | prev)) | |
4930 | return 0; | |
4931 | ||
4932 | return reg_mentioned_p (SET_DEST (single_set (new)), prev) ? 0 : prev; | |
4933 | } | |
06abe5a4 | 4934 | #endif /* !HAVE_cc0 */ |