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5924de0b | 1 | /* Optimize jump instructions, for GNU compiler. |
c773fc10 | 2 | Copyright (C) 1987, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997 |
3 | 1998, 1999, 2000 Free Software Foundation, Inc. | |
5924de0b | 4 | |
5 | This file is part of GNU CC. | |
6 | ||
7 | GNU CC is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GNU CC is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GNU CC; see the file COPYING. If not, write to | |
0355838f | 19 | the Free Software Foundation, 59 Temple Place - Suite 330, |
20 | Boston, MA 02111-1307, USA. */ | |
5924de0b | 21 | |
5924de0b | 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" | |
405711de | 55 | #include "system.h" |
5924de0b | 56 | #include "rtl.h" |
7953c610 | 57 | #include "tm_p.h" |
5924de0b | 58 | #include "flags.h" |
59 | #include "hard-reg-set.h" | |
60 | #include "regs.h" | |
5924de0b | 61 | #include "insn-config.h" |
62 | #include "insn-flags.h" | |
fe3b47be | 63 | #include "insn-attr.h" |
0dbd1c74 | 64 | #include "recog.h" |
0a893c29 | 65 | #include "function.h" |
fa9157fe | 66 | #include "expr.h" |
5924de0b | 67 | #include "real.h" |
485aaaaf | 68 | #include "except.h" |
ce1fd7fc | 69 | #include "toplev.h" |
5924de0b | 70 | |
71 | /* ??? Eventually must record somehow the labels used by jumps | |
72 | from nested functions. */ | |
73 | /* Pre-record the next or previous real insn for each label? | |
74 | No, this pass is very fast anyway. */ | |
75 | /* Condense consecutive labels? | |
76 | This would make life analysis faster, maybe. */ | |
77 | /* Optimize jump y; x: ... y: jumpif... x? | |
78 | Don't know if it is worth bothering with. */ | |
79 | /* Optimize two cases of conditional jump to conditional jump? | |
80 | This can never delete any instruction or make anything dead, | |
81 | or even change what is live at any point. | |
82 | So perhaps let combiner do it. */ | |
83 | ||
84 | /* Vector indexed by uid. | |
85 | For each CODE_LABEL, index by its uid to get first unconditional jump | |
86 | that jumps to the label. | |
87 | For each JUMP_INSN, index by its uid to get the next unconditional jump | |
88 | that jumps to the same label. | |
89 | Element 0 is the start of a chain of all return insns. | |
90 | (It is safe to use element 0 because insn uid 0 is not used. */ | |
91 | ||
92 | static rtx *jump_chain; | |
93 | ||
5924de0b | 94 | /* Maximum index in jump_chain. */ |
95 | ||
96 | static int max_jump_chain; | |
97 | ||
5924de0b | 98 | /* Indicates whether death notes are significant in cross jump analysis. |
99 | Normally they are not significant, because of A and B jump to C, | |
100 | and R dies in A, it must die in B. But this might not be true after | |
101 | stack register conversion, and we must compare death notes in that | |
a92771b8 | 102 | case. */ |
5924de0b | 103 | |
104 | static int cross_jump_death_matters = 0; | |
105 | ||
38b9004f | 106 | static int init_label_info PARAMS ((rtx)); |
107 | static void delete_barrier_successors PARAMS ((rtx)); | |
108 | static void mark_all_labels PARAMS ((rtx, int)); | |
109 | static rtx delete_unreferenced_labels PARAMS ((rtx)); | |
110 | static void delete_noop_moves PARAMS ((rtx)); | |
38b9004f | 111 | static int duplicate_loop_exit_test PARAMS ((rtx)); |
112 | static void find_cross_jump PARAMS ((rtx, rtx, int, rtx *, rtx *)); | |
113 | static void do_cross_jump PARAMS ((rtx, rtx, rtx)); | |
114 | static int jump_back_p PARAMS ((rtx, rtx)); | |
115 | static int tension_vector_labels PARAMS ((rtx, int)); | |
190099a6 | 116 | static void mark_jump_label PARAMS ((rtx, rtx, int, int)); |
38b9004f | 117 | static void delete_computation PARAMS ((rtx)); |
a8b5d014 | 118 | static void redirect_exp_1 PARAMS ((rtx *, rtx, rtx, rtx)); |
ba08b7e7 | 119 | static int redirect_exp PARAMS ((rtx, rtx, rtx)); |
120 | static void invert_exp_1 PARAMS ((rtx)); | |
121 | static int invert_exp PARAMS ((rtx)); | |
38b9004f | 122 | static void delete_from_jump_chain PARAMS ((rtx)); |
123 | static int delete_labelref_insn PARAMS ((rtx, rtx, int)); | |
124 | static void mark_modified_reg PARAMS ((rtx, rtx, void *)); | |
125 | static void redirect_tablejump PARAMS ((rtx, rtx)); | |
60ecc450 | 126 | static void jump_optimize_1 PARAMS ((rtx, int, int, int, int, int)); |
38b9004f | 127 | static int returnjump_p_1 PARAMS ((rtx *, void *)); |
128 | static void delete_prior_computation PARAMS ((rtx, rtx)); | |
60ecc450 | 129 | \f |
8b946ced | 130 | /* Main external entry point into the jump optimizer. See comments before |
131 | jump_optimize_1 for descriptions of the arguments. */ | |
132 | void | |
133 | jump_optimize (f, cross_jump, noop_moves, after_regscan) | |
134 | rtx f; | |
135 | int cross_jump; | |
136 | int noop_moves; | |
137 | int after_regscan; | |
138 | { | |
60ecc450 | 139 | jump_optimize_1 (f, cross_jump, noop_moves, after_regscan, 0, 0); |
8b946ced | 140 | } |
141 | ||
142 | /* Alternate entry into the jump optimizer. This entry point only rebuilds | |
143 | the JUMP_LABEL field in jumping insns and REG_LABEL notes in non-jumping | |
144 | instructions. */ | |
145 | void | |
146 | rebuild_jump_labels (f) | |
147 | rtx f; | |
148 | { | |
60ecc450 | 149 | jump_optimize_1 (f, 0, 0, 0, 1, 0); |
8b946ced | 150 | } |
151 | ||
60ecc450 | 152 | /* Alternate entry into the jump optimizer. Do only trivial optimizations. */ |
7113a566 | 153 | |
60ecc450 | 154 | void |
155 | jump_optimize_minimal (f) | |
156 | rtx f; | |
157 | { | |
158 | jump_optimize_1 (f, 0, 0, 0, 0, 1); | |
159 | } | |
5924de0b | 160 | \f |
161 | /* Delete no-op jumps and optimize jumps to jumps | |
162 | and jumps around jumps. | |
163 | Delete unused labels and unreachable code. | |
164 | ||
165 | If CROSS_JUMP is 1, detect matching code | |
166 | before a jump and its destination and unify them. | |
167 | If CROSS_JUMP is 2, do cross-jumping, but pay attention to death notes. | |
168 | ||
169 | If NOOP_MOVES is nonzero, delete no-op move insns. | |
170 | ||
171 | If AFTER_REGSCAN is nonzero, then this jump pass is being run immediately | |
172 | after regscan, and it is safe to use regno_first_uid and regno_last_uid. | |
173 | ||
8b946ced | 174 | If MARK_LABELS_ONLY is nonzero, then we only rebuild the jump chain |
175 | and JUMP_LABEL field for jumping insns. | |
176 | ||
5924de0b | 177 | If `optimize' is zero, don't change any code, |
178 | just determine whether control drops off the end of the function. | |
179 | This case occurs when we have -W and not -O. | |
180 | It works because `delete_insn' checks the value of `optimize' | |
60ecc450 | 181 | and refrains from actually deleting when that is 0. |
182 | ||
183 | If MINIMAL is nonzero, then we only perform trivial optimizations: | |
184 | ||
185 | * Removal of unreachable code after BARRIERs. | |
186 | * Removal of unreferenced CODE_LABELs. | |
187 | * Removal of a jump to the next instruction. | |
188 | * Removal of a conditional jump followed by an unconditional jump | |
189 | to the same target as the conditional jump. | |
190 | * Simplify a conditional jump around an unconditional jump. | |
191 | * Simplify a jump to a jump. | |
192 | * Delete extraneous line number notes. | |
193 | */ | |
5924de0b | 194 | |
79c0d658 | 195 | static void |
60ecc450 | 196 | jump_optimize_1 (f, cross_jump, noop_moves, after_regscan, |
197 | mark_labels_only, minimal) | |
5924de0b | 198 | rtx f; |
199 | int cross_jump; | |
200 | int noop_moves; | |
201 | int after_regscan; | |
8b946ced | 202 | int mark_labels_only; |
60ecc450 | 203 | int minimal; |
5924de0b | 204 | { |
c785719f | 205 | register rtx insn, next; |
5924de0b | 206 | int changed; |
eb6df919 | 207 | int old_max_reg; |
5924de0b | 208 | int first = 1; |
209 | int max_uid = 0; | |
210 | rtx last_insn; | |
211 | ||
212 | cross_jump_death_matters = (cross_jump == 2); | |
e8d75e01 | 213 | max_uid = init_label_info (f) + 1; |
5924de0b | 214 | |
fa924cfb | 215 | /* If we are performing cross jump optimizations, then initialize |
216 | tables mapping UIDs to EH regions to avoid incorrect movement | |
217 | of insns from one EH region to another. */ | |
218 | if (flag_exceptions && cross_jump) | |
219 | init_insn_eh_region (f, max_uid); | |
220 | ||
9247fbd7 | 221 | if (! mark_labels_only) |
222 | delete_barrier_successors (f); | |
5924de0b | 223 | |
224 | /* Leave some extra room for labels and duplicate exit test insns | |
225 | we make. */ | |
226 | max_jump_chain = max_uid * 14 / 10; | |
8b861be4 | 227 | jump_chain = (rtx *) xcalloc (max_jump_chain, sizeof (rtx)); |
5924de0b | 228 | |
e8d75e01 | 229 | mark_all_labels (f, cross_jump); |
5924de0b | 230 | |
cbd914e1 | 231 | /* Keep track of labels used from static data; we don't track them |
232 | closely enough to delete them here, so make sure their reference | |
233 | count doesn't drop to zero. */ | |
5924de0b | 234 | |
235 | for (insn = forced_labels; insn; insn = XEXP (insn, 1)) | |
cbd914e1 | 236 | if (GET_CODE (XEXP (insn, 0)) == CODE_LABEL) |
237 | LABEL_NUSES (XEXP (insn, 0))++; | |
5924de0b | 238 | |
485aaaaf | 239 | check_exception_handler_labels (); |
240 | ||
241 | /* Keep track of labels used for marking handlers for exception | |
242 | regions; they cannot usually be deleted. */ | |
243 | ||
244 | for (insn = exception_handler_labels; insn; insn = XEXP (insn, 1)) | |
7d27371b | 245 | if (GET_CODE (XEXP (insn, 0)) == CODE_LABEL) |
246 | LABEL_NUSES (XEXP (insn, 0))++; | |
485aaaaf | 247 | |
13d60e7c | 248 | /* Quit now if we just wanted to rebuild the JUMP_LABEL and REG_LABEL |
249 | notes and recompute LABEL_NUSES. */ | |
250 | if (mark_labels_only) | |
8b861be4 | 251 | goto end; |
13d60e7c | 252 | |
60ecc450 | 253 | if (! minimal) |
254 | exception_optimize (); | |
485aaaaf | 255 | |
e8d75e01 | 256 | last_insn = delete_unreferenced_labels (f); |
5924de0b | 257 | |
5924de0b | 258 | if (noop_moves) |
e8d75e01 | 259 | delete_noop_moves (f); |
5924de0b | 260 | |
d78fbdae | 261 | /* If we haven't yet gotten to reload and we have just run regscan, |
262 | delete any insn that sets a register that isn't used elsewhere. | |
263 | This helps some of the optimizations below by having less insns | |
264 | being jumped around. */ | |
265 | ||
dd2acd83 | 266 | if (optimize && ! reload_completed && after_regscan) |
d78fbdae | 267 | for (insn = f; insn; insn = next) |
268 | { | |
269 | rtx set = single_set (insn); | |
270 | ||
271 | next = NEXT_INSN (insn); | |
272 | ||
273 | if (set && GET_CODE (SET_DEST (set)) == REG | |
274 | && REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER | |
394685a4 | 275 | && REGNO_FIRST_UID (REGNO (SET_DEST (set))) == INSN_UID (insn) |
a1bab3d1 | 276 | /* We use regno_last_note_uid so as not to delete the setting |
277 | of a reg that's used in notes. A subsequent optimization | |
7113a566 | 278 | might arrange to use that reg for real. */ |
394685a4 | 279 | && REGNO_LAST_NOTE_UID (REGNO (SET_DEST (set))) == INSN_UID (insn) |
05745bc6 | 280 | && ! side_effects_p (SET_SRC (set)) |
15cec1c3 | 281 | && ! find_reg_note (insn, REG_RETVAL, 0) |
282 | /* An ADDRESSOF expression can turn into a use of the internal arg | |
283 | pointer, so do not delete the initialization of the internal | |
284 | arg pointer yet. If it is truly dead, flow will delete the | |
285 | initializing insn. */ | |
286 | && SET_DEST (set) != current_function_internal_arg_pointer) | |
d78fbdae | 287 | delete_insn (insn); |
288 | } | |
289 | ||
5924de0b | 290 | /* Now iterate optimizing jumps until nothing changes over one pass. */ |
291 | changed = 1; | |
eb6df919 | 292 | old_max_reg = max_reg_num (); |
5924de0b | 293 | while (changed) |
294 | { | |
5924de0b | 295 | changed = 0; |
296 | ||
297 | for (insn = f; insn; insn = next) | |
298 | { | |
299 | rtx reallabelprev; | |
0bb604ca | 300 | rtx temp, temp1, temp2 = NULL_RTX; |
301 | rtx temp4 ATTRIBUTE_UNUSED; | |
5924de0b | 302 | rtx nlabel; |
ba08b7e7 | 303 | int this_is_any_uncondjump; |
304 | int this_is_any_condjump; | |
305 | int this_is_onlyjump; | |
eb6df919 | 306 | |
5924de0b | 307 | next = NEXT_INSN (insn); |
308 | ||
309 | /* See if this is a NOTE_INSN_LOOP_BEG followed by an unconditional | |
310 | jump. Try to optimize by duplicating the loop exit test if so. | |
311 | This is only safe immediately after regscan, because it uses | |
46db9635 | 312 | the values of regno_first_uid and regno_last_uid. */ |
313 | if (after_regscan && GET_CODE (insn) == NOTE | |
5924de0b | 314 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG |
315 | && (temp1 = next_nonnote_insn (insn)) != 0 | |
ba08b7e7 | 316 | && any_uncondjump_p (temp1) |
317 | && onlyjump_p (temp1)) | |
5924de0b | 318 | { |
319 | temp = PREV_INSN (insn); | |
320 | if (duplicate_loop_exit_test (insn)) | |
321 | { | |
322 | changed = 1; | |
323 | next = NEXT_INSN (temp); | |
324 | continue; | |
325 | } | |
326 | } | |
327 | ||
328 | if (GET_CODE (insn) != JUMP_INSN) | |
329 | continue; | |
330 | ||
ba08b7e7 | 331 | this_is_any_condjump = any_condjump_p (insn); |
332 | this_is_any_uncondjump = any_uncondjump_p (insn); | |
333 | this_is_onlyjump = onlyjump_p (insn); | |
5924de0b | 334 | |
335 | /* Tension the labels in dispatch tables. */ | |
336 | ||
337 | if (GET_CODE (PATTERN (insn)) == ADDR_VEC) | |
338 | changed |= tension_vector_labels (PATTERN (insn), 0); | |
339 | if (GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC) | |
340 | changed |= tension_vector_labels (PATTERN (insn), 1); | |
341 | ||
7014838c | 342 | /* See if this jump goes to another jump and redirect if so. */ |
343 | nlabel = follow_jumps (JUMP_LABEL (insn)); | |
344 | if (nlabel != JUMP_LABEL (insn)) | |
f8cacb57 | 345 | changed |= redirect_jump (insn, nlabel, 1); |
7014838c | 346 | |
e3b14ee4 | 347 | if (! optimize || minimal) |
574a2ea5 | 348 | continue; |
349 | ||
5924de0b | 350 | /* If a dispatch table always goes to the same place, |
351 | get rid of it and replace the insn that uses it. */ | |
352 | ||
353 | if (GET_CODE (PATTERN (insn)) == ADDR_VEC | |
354 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC) | |
355 | { | |
356 | int i; | |
357 | rtx pat = PATTERN (insn); | |
358 | int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC; | |
359 | int len = XVECLEN (pat, diff_vec_p); | |
360 | rtx dispatch = prev_real_insn (insn); | |
6ce9e198 | 361 | rtx set; |
5924de0b | 362 | |
363 | for (i = 0; i < len; i++) | |
364 | if (XEXP (XVECEXP (pat, diff_vec_p, i), 0) | |
365 | != XEXP (XVECEXP (pat, diff_vec_p, 0), 0)) | |
366 | break; | |
6ce9e198 | 367 | |
5924de0b | 368 | if (i == len |
4ca1604c | 369 | && dispatch != 0 |
5924de0b | 370 | && GET_CODE (dispatch) == JUMP_INSN |
371 | && JUMP_LABEL (dispatch) != 0 | |
7113a566 | 372 | /* Don't mess with a casesi insn. |
6ce9e198 | 373 | XXX according to the comment before computed_jump_p(), |
374 | all casesi insns should be a parallel of the jump | |
375 | and a USE of a LABEL_REF. */ | |
376 | && ! ((set = single_set (dispatch)) != NULL | |
377 | && (GET_CODE (SET_SRC (set)) == IF_THEN_ELSE)) | |
5924de0b | 378 | && next_real_insn (JUMP_LABEL (dispatch)) == insn) |
379 | { | |
380 | redirect_tablejump (dispatch, | |
381 | XEXP (XVECEXP (pat, diff_vec_p, 0), 0)); | |
382 | changed = 1; | |
383 | } | |
384 | } | |
385 | ||
7014838c | 386 | reallabelprev = prev_active_insn (JUMP_LABEL (insn)); |
387 | ||
5924de0b | 388 | /* Detect jump to following insn. */ |
ba08b7e7 | 389 | if (reallabelprev == insn |
390 | && (this_is_any_condjump || this_is_any_uncondjump) | |
391 | && this_is_onlyjump) | |
5924de0b | 392 | { |
92d3c3ad | 393 | next = next_real_insn (JUMP_LABEL (insn)); |
5924de0b | 394 | delete_jump (insn); |
1f94660f | 395 | |
396 | /* Remove the "inactive" but "real" insns (i.e. uses and | |
397 | clobbers) in between here and there. */ | |
398 | temp = insn; | |
399 | while ((temp = next_real_insn (temp)) != next) | |
400 | delete_insn (temp); | |
401 | ||
5924de0b | 402 | changed = 1; |
403 | continue; | |
404 | } | |
405 | ||
7014838c | 406 | /* Detect a conditional jump going to the same place |
407 | as an immediately following unconditional jump. */ | |
ba08b7e7 | 408 | else if (this_is_any_condjump && this_is_onlyjump |
7014838c | 409 | && (temp = next_active_insn (insn)) != 0 |
410 | && simplejump_p (temp) | |
411 | && (next_active_insn (JUMP_LABEL (insn)) | |
412 | == next_active_insn (JUMP_LABEL (temp)))) | |
413 | { | |
414 | /* Don't mess up test coverage analysis. */ | |
415 | temp2 = temp; | |
416 | if (flag_test_coverage && !reload_completed) | |
417 | for (temp2 = insn; temp2 != temp; temp2 = NEXT_INSN (temp2)) | |
418 | if (GET_CODE (temp2) == NOTE && NOTE_LINE_NUMBER (temp2) > 0) | |
419 | break; | |
7113a566 | 420 | |
7014838c | 421 | if (temp2 == temp) |
422 | { | |
423 | delete_jump (insn); | |
424 | changed = 1; | |
425 | continue; | |
426 | } | |
427 | } | |
428 | ||
429 | /* Detect a conditional jump jumping over an unconditional jump. */ | |
430 | ||
ba08b7e7 | 431 | else if (this_is_any_condjump |
7014838c | 432 | && reallabelprev != 0 |
433 | && GET_CODE (reallabelprev) == JUMP_INSN | |
434 | && prev_active_insn (reallabelprev) == insn | |
435 | && no_labels_between_p (insn, reallabelprev) | |
ba08b7e7 | 436 | && any_uncondjump_p (reallabelprev) |
437 | && onlyjump_p (reallabelprev)) | |
7014838c | 438 | { |
439 | /* When we invert the unconditional jump, we will be | |
440 | decrementing the usage count of its old label. | |
441 | Make sure that we don't delete it now because that | |
442 | might cause the following code to be deleted. */ | |
443 | rtx prev_uses = prev_nonnote_insn (reallabelprev); | |
444 | rtx prev_label = JUMP_LABEL (insn); | |
445 | ||
446 | if (prev_label) | |
447 | ++LABEL_NUSES (prev_label); | |
448 | ||
f8cacb57 | 449 | if (invert_jump (insn, JUMP_LABEL (reallabelprev), 1)) |
7014838c | 450 | { |
451 | /* It is very likely that if there are USE insns before | |
452 | this jump, they hold REG_DEAD notes. These REG_DEAD | |
453 | notes are no longer valid due to this optimization, | |
454 | and will cause the life-analysis that following passes | |
455 | (notably delayed-branch scheduling) to think that | |
456 | these registers are dead when they are not. | |
457 | ||
458 | To prevent this trouble, we just remove the USE insns | |
459 | from the insn chain. */ | |
460 | ||
461 | while (prev_uses && GET_CODE (prev_uses) == INSN | |
462 | && GET_CODE (PATTERN (prev_uses)) == USE) | |
463 | { | |
464 | rtx useless = prev_uses; | |
465 | prev_uses = prev_nonnote_insn (prev_uses); | |
466 | delete_insn (useless); | |
467 | } | |
468 | ||
469 | delete_insn (reallabelprev); | |
470 | changed = 1; | |
471 | } | |
472 | ||
473 | /* We can now safely delete the label if it is unreferenced | |
474 | since the delete_insn above has deleted the BARRIER. */ | |
475 | if (prev_label && --LABEL_NUSES (prev_label) == 0) | |
476 | delete_insn (prev_label); | |
477 | ||
478 | next = NEXT_INSN (insn); | |
479 | } | |
480 | ||
f9e15121 | 481 | /* If we have an unconditional jump preceded by a USE, try to put |
5924de0b | 482 | the USE before the target and jump there. This simplifies many |
483 | of the optimizations below since we don't have to worry about | |
484 | dealing with these USE insns. We only do this if the label | |
485 | being branch to already has the identical USE or if code | |
486 | never falls through to that label. */ | |
487 | ||
ba08b7e7 | 488 | else if (this_is_any_uncondjump |
7014838c | 489 | && (temp = prev_nonnote_insn (insn)) != 0 |
490 | && GET_CODE (temp) == INSN | |
491 | && GET_CODE (PATTERN (temp)) == USE | |
492 | && (temp1 = prev_nonnote_insn (JUMP_LABEL (insn))) != 0 | |
493 | && (GET_CODE (temp1) == BARRIER | |
494 | || (GET_CODE (temp1) == INSN | |
495 | && rtx_equal_p (PATTERN (temp), PATTERN (temp1)))) | |
496 | /* Don't do this optimization if we have a loop containing | |
497 | only the USE instruction, and the loop start label has | |
498 | a usage count of 1. This is because we will redo this | |
499 | optimization everytime through the outer loop, and jump | |
500 | opt will never exit. */ | |
501 | && ! ((temp2 = prev_nonnote_insn (temp)) != 0 | |
502 | && temp2 == JUMP_LABEL (insn) | |
503 | && LABEL_NUSES (temp2) == 1)) | |
5924de0b | 504 | { |
505 | if (GET_CODE (temp1) == BARRIER) | |
506 | { | |
d78fbdae | 507 | emit_insn_after (PATTERN (temp), temp1); |
5924de0b | 508 | temp1 = NEXT_INSN (temp1); |
509 | } | |
5924de0b | 510 | |
d78fbdae | 511 | delete_insn (temp); |
f8cacb57 | 512 | redirect_jump (insn, get_label_before (temp1), 1); |
5924de0b | 513 | reallabelprev = prev_real_insn (temp1); |
514 | changed = 1; | |
7014838c | 515 | next = NEXT_INSN (insn); |
5924de0b | 516 | } |
517 | ||
9e5192ed | 518 | #ifdef HAVE_trap |
519 | /* Detect a conditional jump jumping over an unconditional trap. */ | |
0bb604ca | 520 | if (HAVE_trap |
ba08b7e7 | 521 | && this_is_any_condjump && this_is_onlyjump |
0bb604ca | 522 | && reallabelprev != 0 |
523 | && GET_CODE (reallabelprev) == INSN | |
524 | && GET_CODE (PATTERN (reallabelprev)) == TRAP_IF | |
525 | && TRAP_CONDITION (PATTERN (reallabelprev)) == const_true_rtx | |
526 | && prev_active_insn (reallabelprev) == insn | |
527 | && no_labels_between_p (insn, reallabelprev) | |
528 | && (temp2 = get_condition (insn, &temp4)) | |
529 | && can_reverse_comparison_p (temp2, insn)) | |
9e5192ed | 530 | { |
531 | rtx new = gen_cond_trap (reverse_condition (GET_CODE (temp2)), | |
532 | XEXP (temp2, 0), XEXP (temp2, 1), | |
533 | TRAP_CODE (PATTERN (reallabelprev))); | |
534 | ||
535 | if (new) | |
536 | { | |
537 | emit_insn_before (new, temp4); | |
538 | delete_insn (reallabelprev); | |
539 | delete_jump (insn); | |
540 | changed = 1; | |
541 | continue; | |
542 | } | |
543 | } | |
544 | /* Detect a jump jumping to an unconditional trap. */ | |
ba08b7e7 | 545 | else if (HAVE_trap && this_is_onlyjump |
9e5192ed | 546 | && (temp = next_active_insn (JUMP_LABEL (insn))) |
547 | && GET_CODE (temp) == INSN | |
548 | && GET_CODE (PATTERN (temp)) == TRAP_IF | |
ba08b7e7 | 549 | && (this_is_any_uncondjump |
550 | || (this_is_any_condjump | |
b2816317 | 551 | && (temp2 = get_condition (insn, &temp4))))) |
9e5192ed | 552 | { |
553 | rtx tc = TRAP_CONDITION (PATTERN (temp)); | |
554 | ||
555 | if (tc == const_true_rtx | |
b2816317 | 556 | || (! this_is_any_uncondjump && rtx_equal_p (temp2, tc))) |
9e5192ed | 557 | { |
558 | rtx new; | |
559 | /* Replace an unconditional jump to a trap with a trap. */ | |
b2816317 | 560 | if (this_is_any_uncondjump) |
9e5192ed | 561 | { |
562 | emit_barrier_after (emit_insn_before (gen_trap (), insn)); | |
563 | delete_jump (insn); | |
564 | changed = 1; | |
565 | continue; | |
566 | } | |
567 | new = gen_cond_trap (GET_CODE (temp2), XEXP (temp2, 0), | |
568 | XEXP (temp2, 1), | |
569 | TRAP_CODE (PATTERN (temp))); | |
570 | if (new) | |
571 | { | |
572 | emit_insn_before (new, temp4); | |
573 | delete_jump (insn); | |
574 | changed = 1; | |
575 | continue; | |
576 | } | |
577 | } | |
578 | /* If the trap condition and jump condition are mutually | |
579 | exclusive, redirect the jump to the following insn. */ | |
580 | else if (GET_RTX_CLASS (GET_CODE (tc)) == '<' | |
ba08b7e7 | 581 | && this_is_any_condjump |
9e5192ed | 582 | && swap_condition (GET_CODE (temp2)) == GET_CODE (tc) |
583 | && rtx_equal_p (XEXP (tc, 0), XEXP (temp2, 0)) | |
584 | && rtx_equal_p (XEXP (tc, 1), XEXP (temp2, 1)) | |
f8cacb57 | 585 | && redirect_jump (insn, get_label_after (temp), 1)) |
9e5192ed | 586 | { |
587 | changed = 1; | |
588 | continue; | |
589 | } | |
590 | } | |
591 | #endif | |
5924de0b | 592 | else |
593 | { | |
5924de0b | 594 | /* Now that the jump has been tensioned, |
595 | try cross jumping: check for identical code | |
a92771b8 | 596 | before the jump and before its target label. */ |
5924de0b | 597 | |
598 | /* First, cross jumping of conditional jumps: */ | |
599 | ||
600 | if (cross_jump && condjump_p (insn)) | |
601 | { | |
602 | rtx newjpos, newlpos; | |
603 | rtx x = prev_real_insn (JUMP_LABEL (insn)); | |
604 | ||
605 | /* A conditional jump may be crossjumped | |
606 | only if the place it jumps to follows | |
607 | an opposing jump that comes back here. */ | |
608 | ||
609 | if (x != 0 && ! jump_back_p (x, insn)) | |
610 | /* We have no opposing jump; | |
611 | cannot cross jump this insn. */ | |
612 | x = 0; | |
613 | ||
614 | newjpos = 0; | |
615 | /* TARGET is nonzero if it is ok to cross jump | |
616 | to code before TARGET. If so, see if matches. */ | |
617 | if (x != 0) | |
e3975dea | 618 | find_cross_jump (insn, x, 2, |
5924de0b | 619 | &newjpos, &newlpos); |
620 | ||
621 | if (newjpos != 0) | |
622 | { | |
623 | do_cross_jump (insn, newjpos, newlpos); | |
624 | /* Make the old conditional jump | |
625 | into an unconditional one. */ | |
626 | SET_SRC (PATTERN (insn)) | |
941522d6 | 627 | = gen_rtx_LABEL_REF (VOIDmode, JUMP_LABEL (insn)); |
5924de0b | 628 | INSN_CODE (insn) = -1; |
629 | emit_barrier_after (insn); | |
630 | /* Add to jump_chain unless this is a new label | |
a92771b8 | 631 | whose UID is too large. */ |
5924de0b | 632 | if (INSN_UID (JUMP_LABEL (insn)) < max_jump_chain) |
633 | { | |
634 | jump_chain[INSN_UID (insn)] | |
635 | = jump_chain[INSN_UID (JUMP_LABEL (insn))]; | |
636 | jump_chain[INSN_UID (JUMP_LABEL (insn))] = insn; | |
637 | } | |
638 | changed = 1; | |
639 | next = insn; | |
640 | } | |
641 | } | |
642 | ||
643 | /* Cross jumping of unconditional jumps: | |
644 | a few differences. */ | |
645 | ||
646 | if (cross_jump && simplejump_p (insn)) | |
647 | { | |
648 | rtx newjpos, newlpos; | |
649 | rtx target; | |
650 | ||
651 | newjpos = 0; | |
652 | ||
653 | /* TARGET is nonzero if it is ok to cross jump | |
654 | to code before TARGET. If so, see if matches. */ | |
e3975dea | 655 | find_cross_jump (insn, JUMP_LABEL (insn), 1, |
5924de0b | 656 | &newjpos, &newlpos); |
657 | ||
658 | /* If cannot cross jump to code before the label, | |
659 | see if we can cross jump to another jump to | |
660 | the same label. */ | |
661 | /* Try each other jump to this label. */ | |
662 | if (INSN_UID (JUMP_LABEL (insn)) < max_uid) | |
663 | for (target = jump_chain[INSN_UID (JUMP_LABEL (insn))]; | |
664 | target != 0 && newjpos == 0; | |
665 | target = jump_chain[INSN_UID (target)]) | |
666 | if (target != insn | |
667 | && JUMP_LABEL (target) == JUMP_LABEL (insn) | |
668 | /* Ignore TARGET if it's deleted. */ | |
669 | && ! INSN_DELETED_P (target)) | |
e3975dea | 670 | find_cross_jump (insn, target, 2, |
5924de0b | 671 | &newjpos, &newlpos); |
672 | ||
673 | if (newjpos != 0) | |
674 | { | |
675 | do_cross_jump (insn, newjpos, newlpos); | |
676 | changed = 1; | |
677 | next = insn; | |
678 | } | |
679 | } | |
680 | ||
681 | /* This code was dead in the previous jump.c! */ | |
682 | if (cross_jump && GET_CODE (PATTERN (insn)) == RETURN) | |
683 | { | |
684 | /* Return insns all "jump to the same place" | |
685 | so we can cross-jump between any two of them. */ | |
686 | ||
687 | rtx newjpos, newlpos, target; | |
688 | ||
689 | newjpos = 0; | |
690 | ||
691 | /* If cannot cross jump to code before the label, | |
692 | see if we can cross jump to another jump to | |
693 | the same label. */ | |
694 | /* Try each other jump to this label. */ | |
695 | for (target = jump_chain[0]; | |
696 | target != 0 && newjpos == 0; | |
697 | target = jump_chain[INSN_UID (target)]) | |
698 | if (target != insn | |
699 | && ! INSN_DELETED_P (target) | |
700 | && GET_CODE (PATTERN (target)) == RETURN) | |
e3975dea | 701 | find_cross_jump (insn, target, 2, |
5924de0b | 702 | &newjpos, &newlpos); |
703 | ||
704 | if (newjpos != 0) | |
705 | { | |
706 | do_cross_jump (insn, newjpos, newlpos); | |
707 | changed = 1; | |
708 | next = insn; | |
709 | } | |
710 | } | |
711 | } | |
712 | } | |
713 | ||
714 | first = 0; | |
715 | } | |
716 | ||
717 | /* Delete extraneous line number notes. | |
718 | Note that two consecutive notes for different lines are not really | |
719 | extraneous. There should be some indication where that line belonged, | |
720 | even if it became empty. */ | |
721 | ||
722 | { | |
723 | rtx last_note = 0; | |
724 | ||
725 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
726 | if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) >= 0) | |
727 | { | |
728 | /* Delete this note if it is identical to previous note. */ | |
729 | if (last_note | |
730 | && NOTE_SOURCE_FILE (insn) == NOTE_SOURCE_FILE (last_note) | |
731 | && NOTE_LINE_NUMBER (insn) == NOTE_LINE_NUMBER (last_note)) | |
732 | { | |
733 | delete_insn (insn); | |
734 | continue; | |
735 | } | |
736 | ||
737 | last_note = insn; | |
738 | } | |
739 | } | |
740 | ||
8b861be4 | 741 | end: |
742 | /* Clean up. */ | |
743 | free (jump_chain); | |
e8d75e01 | 744 | jump_chain = 0; |
745 | } | |
746 | \f | |
747 | /* Initialize LABEL_NUSES and JUMP_LABEL fields. Delete any REG_LABEL | |
748 | notes whose labels don't occur in the insn any more. Returns the | |
749 | largest INSN_UID found. */ | |
750 | static int | |
751 | init_label_info (f) | |
752 | rtx f; | |
753 | { | |
754 | int largest_uid = 0; | |
755 | rtx insn; | |
756 | ||
757 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
758 | { | |
759 | if (GET_CODE (insn) == CODE_LABEL) | |
760 | LABEL_NUSES (insn) = (LABEL_PRESERVE_P (insn) != 0); | |
761 | else if (GET_CODE (insn) == JUMP_INSN) | |
762 | JUMP_LABEL (insn) = 0; | |
763 | else if (GET_CODE (insn) == INSN || GET_CODE (insn) == CALL_INSN) | |
764 | { | |
765 | rtx note, next; | |
766 | ||
767 | for (note = REG_NOTES (insn); note; note = next) | |
768 | { | |
769 | next = XEXP (note, 1); | |
770 | if (REG_NOTE_KIND (note) == REG_LABEL | |
771 | && ! reg_mentioned_p (XEXP (note, 0), PATTERN (insn))) | |
772 | remove_note (insn, note); | |
773 | } | |
774 | } | |
775 | if (INSN_UID (insn) > largest_uid) | |
776 | largest_uid = INSN_UID (insn); | |
777 | } | |
778 | ||
779 | return largest_uid; | |
780 | } | |
781 | ||
7113a566 | 782 | /* Delete insns following barriers, up to next label. |
c5826237 | 783 | |
784 | Also delete no-op jumps created by gcse. */ | |
9247fbd7 | 785 | |
e8d75e01 | 786 | static void |
787 | delete_barrier_successors (f) | |
788 | rtx f; | |
789 | { | |
790 | rtx insn; | |
ba08b7e7 | 791 | rtx set; |
e8d75e01 | 792 | |
793 | for (insn = f; insn;) | |
794 | { | |
795 | if (GET_CODE (insn) == BARRIER) | |
796 | { | |
797 | insn = NEXT_INSN (insn); | |
71a3455a | 798 | |
799 | never_reached_warning (insn); | |
800 | ||
e8d75e01 | 801 | while (insn != 0 && GET_CODE (insn) != CODE_LABEL) |
802 | { | |
803 | if (GET_CODE (insn) == NOTE | |
804 | && NOTE_LINE_NUMBER (insn) != NOTE_INSN_FUNCTION_END) | |
805 | insn = NEXT_INSN (insn); | |
806 | else | |
807 | insn = delete_insn (insn); | |
808 | } | |
809 | /* INSN is now the code_label. */ | |
810 | } | |
9247fbd7 | 811 | |
c5826237 | 812 | /* Also remove (set (pc) (pc)) insns which can be created by |
813 | gcse. We eliminate such insns now to avoid having them | |
814 | cause problems later. */ | |
815 | else if (GET_CODE (insn) == JUMP_INSN | |
ba08b7e7 | 816 | && (set = pc_set (insn)) != NULL |
817 | && SET_SRC (set) == pc_rtx | |
818 | && SET_DEST (set) == pc_rtx | |
819 | && onlyjump_p (insn)) | |
c5826237 | 820 | insn = delete_insn (insn); |
821 | ||
e8d75e01 | 822 | else |
823 | insn = NEXT_INSN (insn); | |
824 | } | |
825 | } | |
826 | ||
827 | /* Mark the label each jump jumps to. | |
828 | Combine consecutive labels, and count uses of labels. | |
829 | ||
830 | For each label, make a chain (using `jump_chain') | |
831 | of all the *unconditional* jumps that jump to it; | |
832 | also make a chain of all returns. | |
833 | ||
834 | CROSS_JUMP indicates whether we are doing cross jumping | |
835 | and if we are whether we will be paying attention to | |
836 | death notes or not. */ | |
837 | ||
838 | static void | |
839 | mark_all_labels (f, cross_jump) | |
840 | rtx f; | |
841 | int cross_jump; | |
842 | { | |
843 | rtx insn; | |
844 | ||
845 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
9204e736 | 846 | if (INSN_P (insn)) |
e8d75e01 | 847 | { |
0e3150ce | 848 | if (GET_CODE (insn) == CALL_INSN |
849 | && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER) | |
850 | { | |
851 | mark_all_labels (XEXP (PATTERN (insn), 0), cross_jump); | |
852 | mark_all_labels (XEXP (PATTERN (insn), 1), cross_jump); | |
853 | mark_all_labels (XEXP (PATTERN (insn), 2), cross_jump); | |
854 | continue; | |
855 | } | |
7113a566 | 856 | |
190099a6 | 857 | mark_jump_label (PATTERN (insn), insn, cross_jump, 0); |
e8d75e01 | 858 | if (! INSN_DELETED_P (insn) && GET_CODE (insn) == JUMP_INSN) |
859 | { | |
860 | if (JUMP_LABEL (insn) != 0 && simplejump_p (insn)) | |
861 | { | |
862 | jump_chain[INSN_UID (insn)] | |
863 | = jump_chain[INSN_UID (JUMP_LABEL (insn))]; | |
864 | jump_chain[INSN_UID (JUMP_LABEL (insn))] = insn; | |
865 | } | |
866 | if (GET_CODE (PATTERN (insn)) == RETURN) | |
867 | { | |
868 | jump_chain[INSN_UID (insn)] = jump_chain[0]; | |
869 | jump_chain[0] = insn; | |
870 | } | |
871 | } | |
872 | } | |
873 | } | |
874 | ||
875 | /* Delete all labels already not referenced. | |
876 | Also find and return the last insn. */ | |
877 | ||
878 | static rtx | |
879 | delete_unreferenced_labels (f) | |
880 | rtx f; | |
881 | { | |
882 | rtx final = NULL_RTX; | |
883 | rtx insn; | |
884 | ||
7113a566 | 885 | for (insn = f; insn;) |
e8d75e01 | 886 | { |
bfee5366 | 887 | if (GET_CODE (insn) == CODE_LABEL |
7113a566 | 888 | && LABEL_NUSES (insn) == 0 |
889 | && LABEL_ALTERNATE_NAME (insn) == NULL) | |
e8d75e01 | 890 | insn = delete_insn (insn); |
891 | else | |
892 | { | |
893 | final = insn; | |
894 | insn = NEXT_INSN (insn); | |
895 | } | |
896 | } | |
897 | ||
898 | return final; | |
899 | } | |
900 | ||
901 | /* Delete various simple forms of moves which have no necessary | |
902 | side effect. */ | |
903 | ||
904 | static void | |
905 | delete_noop_moves (f) | |
906 | rtx f; | |
907 | { | |
908 | rtx insn, next; | |
909 | ||
7113a566 | 910 | for (insn = f; insn;) |
e8d75e01 | 911 | { |
912 | next = NEXT_INSN (insn); | |
913 | ||
914 | if (GET_CODE (insn) == INSN) | |
915 | { | |
916 | register rtx body = PATTERN (insn); | |
917 | ||
e8d75e01 | 918 | /* Detect and delete no-op move instructions |
919 | resulting from not allocating a parameter in a register. */ | |
920 | ||
921 | if (GET_CODE (body) == SET | |
922 | && (SET_DEST (body) == SET_SRC (body) | |
923 | || (GET_CODE (SET_DEST (body)) == MEM | |
924 | && GET_CODE (SET_SRC (body)) == MEM | |
925 | && rtx_equal_p (SET_SRC (body), SET_DEST (body)))) | |
926 | && ! (GET_CODE (SET_DEST (body)) == MEM | |
927 | && MEM_VOLATILE_P (SET_DEST (body))) | |
928 | && ! (GET_CODE (SET_SRC (body)) == MEM | |
929 | && MEM_VOLATILE_P (SET_SRC (body)))) | |
930 | delete_computation (insn); | |
931 | ||
932 | /* Detect and ignore no-op move instructions | |
933 | resulting from smart or fortuitous register allocation. */ | |
934 | ||
935 | else if (GET_CODE (body) == SET) | |
936 | { | |
937 | int sreg = true_regnum (SET_SRC (body)); | |
938 | int dreg = true_regnum (SET_DEST (body)); | |
939 | ||
940 | if (sreg == dreg && sreg >= 0) | |
941 | delete_insn (insn); | |
942 | else if (sreg >= 0 && dreg >= 0) | |
943 | { | |
944 | rtx trial; | |
945 | rtx tem = find_equiv_reg (NULL_RTX, insn, 0, | |
946 | sreg, NULL_PTR, dreg, | |
947 | GET_MODE (SET_SRC (body))); | |
948 | ||
949 | if (tem != 0 | |
950 | && GET_MODE (tem) == GET_MODE (SET_DEST (body))) | |
951 | { | |
952 | /* DREG may have been the target of a REG_DEAD note in | |
953 | the insn which makes INSN redundant. If so, reorg | |
954 | would still think it is dead. So search for such a | |
955 | note and delete it if we find it. */ | |
956 | if (! find_regno_note (insn, REG_UNUSED, dreg)) | |
957 | for (trial = prev_nonnote_insn (insn); | |
958 | trial && GET_CODE (trial) != CODE_LABEL; | |
959 | trial = prev_nonnote_insn (trial)) | |
960 | if (find_regno_note (trial, REG_DEAD, dreg)) | |
961 | { | |
962 | remove_death (dreg, trial); | |
963 | break; | |
964 | } | |
965 | ||
966 | /* Deleting insn could lose a death-note for SREG. */ | |
967 | if ((trial = find_regno_note (insn, REG_DEAD, sreg))) | |
968 | { | |
969 | /* Change this into a USE so that we won't emit | |
970 | code for it, but still can keep the note. */ | |
971 | PATTERN (insn) | |
972 | = gen_rtx_USE (VOIDmode, XEXP (trial, 0)); | |
973 | INSN_CODE (insn) = -1; | |
974 | /* Remove all reg notes but the REG_DEAD one. */ | |
975 | REG_NOTES (insn) = trial; | |
976 | XEXP (trial, 1) = NULL_RTX; | |
977 | } | |
978 | else | |
979 | delete_insn (insn); | |
980 | } | |
981 | } | |
982 | else if (dreg >= 0 && CONSTANT_P (SET_SRC (body)) | |
983 | && find_equiv_reg (SET_SRC (body), insn, 0, dreg, | |
984 | NULL_PTR, 0, | |
985 | GET_MODE (SET_DEST (body)))) | |
986 | { | |
987 | /* This handles the case where we have two consecutive | |
988 | assignments of the same constant to pseudos that didn't | |
989 | get a hard reg. Each SET from the constant will be | |
990 | converted into a SET of the spill register and an | |
991 | output reload will be made following it. This produces | |
992 | two loads of the same constant into the same spill | |
993 | register. */ | |
994 | ||
995 | rtx in_insn = insn; | |
996 | ||
997 | /* Look back for a death note for the first reg. | |
998 | If there is one, it is no longer accurate. */ | |
999 | while (in_insn && GET_CODE (in_insn) != CODE_LABEL) | |
1000 | { | |
1001 | if ((GET_CODE (in_insn) == INSN | |
1002 | || GET_CODE (in_insn) == JUMP_INSN) | |
1003 | && find_regno_note (in_insn, REG_DEAD, dreg)) | |
1004 | { | |
1005 | remove_death (dreg, in_insn); | |
1006 | break; | |
1007 | } | |
1008 | in_insn = PREV_INSN (in_insn); | |
1009 | } | |
1010 | ||
1011 | /* Delete the second load of the value. */ | |
1012 | delete_insn (insn); | |
1013 | } | |
1014 | } | |
1015 | else if (GET_CODE (body) == PARALLEL) | |
1016 | { | |
1017 | /* If each part is a set between two identical registers or | |
1018 | a USE or CLOBBER, delete the insn. */ | |
1019 | int i, sreg, dreg; | |
1020 | rtx tem; | |
1021 | ||
1022 | for (i = XVECLEN (body, 0) - 1; i >= 0; i--) | |
1023 | { | |
1024 | tem = XVECEXP (body, 0, i); | |
1025 | if (GET_CODE (tem) == USE || GET_CODE (tem) == CLOBBER) | |
1026 | continue; | |
1027 | ||
1028 | if (GET_CODE (tem) != SET | |
1029 | || (sreg = true_regnum (SET_SRC (tem))) < 0 | |
1030 | || (dreg = true_regnum (SET_DEST (tem))) < 0 | |
1031 | || dreg != sreg) | |
1032 | break; | |
1033 | } | |
7113a566 | 1034 | |
e8d75e01 | 1035 | if (i < 0) |
1036 | delete_insn (insn); | |
1037 | } | |
1038 | /* Also delete insns to store bit fields if they are no-ops. */ | |
1039 | /* Not worth the hair to detect this in the big-endian case. */ | |
1040 | else if (! BYTES_BIG_ENDIAN | |
1041 | && GET_CODE (body) == SET | |
1042 | && GET_CODE (SET_DEST (body)) == ZERO_EXTRACT | |
1043 | && XEXP (SET_DEST (body), 2) == const0_rtx | |
1044 | && XEXP (SET_DEST (body), 0) == SET_SRC (body) | |
1045 | && ! (GET_CODE (SET_SRC (body)) == MEM | |
1046 | && MEM_VOLATILE_P (SET_SRC (body)))) | |
1047 | delete_insn (insn); | |
1048 | } | |
1049 | insn = next; | |
1050 | } | |
1051 | } | |
1052 | ||
5924de0b | 1053 | /* LOOP_START is a NOTE_INSN_LOOP_BEG note that is followed by an unconditional |
1054 | jump. Assume that this unconditional jump is to the exit test code. If | |
1055 | the code is sufficiently simple, make a copy of it before INSN, | |
1056 | followed by a jump to the exit of the loop. Then delete the unconditional | |
1057 | jump after INSN. | |
1058 | ||
5924de0b | 1059 | Return 1 if we made the change, else 0. |
1060 | ||
1061 | This is only safe immediately after a regscan pass because it uses the | |
1062 | values of regno_first_uid and regno_last_uid. */ | |
1063 | ||
1064 | static int | |
1065 | duplicate_loop_exit_test (loop_start) | |
1066 | rtx loop_start; | |
1067 | { | |
3a348c93 | 1068 | rtx insn, set, reg, p, link; |
4e717234 | 1069 | rtx copy = 0, first_copy = 0; |
5924de0b | 1070 | int num_insns = 0; |
1071 | rtx exitcode = NEXT_INSN (JUMP_LABEL (next_nonnote_insn (loop_start))); | |
1072 | rtx lastexit; | |
1073 | int max_reg = max_reg_num (); | |
1074 | rtx *reg_map = 0; | |
1075 | ||
1076 | /* Scan the exit code. We do not perform this optimization if any insn: | |
1077 | ||
1078 | is a CALL_INSN | |
1079 | is a CODE_LABEL | |
1080 | has a REG_RETVAL or REG_LIBCALL note (hard to adjust) | |
1081 | is a NOTE_INSN_LOOP_BEG because this means we have a nested loop | |
1082 | is a NOTE_INSN_BLOCK_{BEG,END} because duplicating these notes | |
7665c376 | 1083 | is not valid. |
17b1950c | 1084 | |
1085 | We also do not do this if we find an insn with ASM_OPERANDS. While | |
1086 | this restriction should not be necessary, copying an insn with | |
1087 | ASM_OPERANDS can confuse asm_noperands in some cases. | |
5924de0b | 1088 | |
1089 | Also, don't do this if the exit code is more than 20 insns. */ | |
1090 | ||
1091 | for (insn = exitcode; | |
1092 | insn | |
1093 | && ! (GET_CODE (insn) == NOTE | |
1094 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END); | |
1095 | insn = NEXT_INSN (insn)) | |
1096 | { | |
1097 | switch (GET_CODE (insn)) | |
1098 | { | |
1099 | case CODE_LABEL: | |
1100 | case CALL_INSN: | |
1101 | return 0; | |
1102 | case NOTE: | |
801acb81 | 1103 | /* We could be in front of the wrong NOTE_INSN_LOOP_END if there is |
1104 | a jump immediately after the loop start that branches outside | |
1105 | the loop but within an outer loop, near the exit test. | |
1106 | If we copied this exit test and created a phony | |
1107 | NOTE_INSN_LOOP_VTOP, this could make instructions immediately | |
1108 | before the exit test look like these could be safely moved | |
1109 | out of the loop even if they actually may be never executed. | |
1110 | This can be avoided by checking here for NOTE_INSN_LOOP_CONT. */ | |
1111 | ||
5924de0b | 1112 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG |
801acb81 | 1113 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_CONT) |
5924de0b | 1114 | return 0; |
ec6be638 | 1115 | |
1116 | if (optimize < 2 | |
1117 | && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG | |
1118 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)) | |
1119 | /* If we were to duplicate this code, we would not move | |
1120 | the BLOCK notes, and so debugging the moved code would | |
1121 | be difficult. Thus, we only move the code with -O2 or | |
1122 | higher. */ | |
1123 | return 0; | |
1124 | ||
5924de0b | 1125 | break; |
1126 | case JUMP_INSN: | |
1127 | case INSN: | |
7665c376 | 1128 | /* The code below would grossly mishandle REG_WAS_0 notes, |
1129 | so get rid of them here. */ | |
1130 | while ((p = find_reg_note (insn, REG_WAS_0, NULL_RTX)) != 0) | |
1131 | remove_note (insn, p); | |
5924de0b | 1132 | if (++num_insns > 20 |
1bb04728 | 1133 | || find_reg_note (insn, REG_RETVAL, NULL_RTX) |
928d57e3 | 1134 | || find_reg_note (insn, REG_LIBCALL, NULL_RTX)) |
5924de0b | 1135 | return 0; |
1136 | break; | |
0dbd1c74 | 1137 | default: |
1138 | break; | |
5924de0b | 1139 | } |
1140 | } | |
1141 | ||
1142 | /* Unless INSN is zero, we can do the optimization. */ | |
1143 | if (insn == 0) | |
1144 | return 0; | |
1145 | ||
1146 | lastexit = insn; | |
1147 | ||
1148 | /* See if any insn sets a register only used in the loop exit code and | |
1149 | not a user variable. If so, replace it with a new register. */ | |
1150 | for (insn = exitcode; insn != lastexit; insn = NEXT_INSN (insn)) | |
1151 | if (GET_CODE (insn) == INSN | |
1152 | && (set = single_set (insn)) != 0 | |
3a348c93 | 1153 | && ((reg = SET_DEST (set), GET_CODE (reg) == REG) |
1154 | || (GET_CODE (reg) == SUBREG | |
1155 | && (reg = SUBREG_REG (reg), GET_CODE (reg) == REG))) | |
1156 | && REGNO (reg) >= FIRST_PSEUDO_REGISTER | |
394685a4 | 1157 | && REGNO_FIRST_UID (REGNO (reg)) == INSN_UID (insn)) |
5924de0b | 1158 | { |
1159 | for (p = NEXT_INSN (insn); p != lastexit; p = NEXT_INSN (p)) | |
394685a4 | 1160 | if (REGNO_LAST_UID (REGNO (reg)) == INSN_UID (p)) |
5924de0b | 1161 | break; |
1162 | ||
1163 | if (p != lastexit) | |
1164 | { | |
1165 | /* We can do the replacement. Allocate reg_map if this is the | |
1166 | first replacement we found. */ | |
1167 | if (reg_map == 0) | |
8b861be4 | 1168 | reg_map = (rtx *) xcalloc (max_reg, sizeof (rtx)); |
5924de0b | 1169 | |
3a348c93 | 1170 | REG_LOOP_TEST_P (reg) = 1; |
5924de0b | 1171 | |
3a348c93 | 1172 | reg_map[REGNO (reg)] = gen_reg_rtx (GET_MODE (reg)); |
5924de0b | 1173 | } |
1174 | } | |
1175 | ||
1176 | /* Now copy each insn. */ | |
1177 | for (insn = exitcode; insn != lastexit; insn = NEXT_INSN (insn)) | |
4e717234 | 1178 | { |
1179 | switch (GET_CODE (insn)) | |
1180 | { | |
1181 | case BARRIER: | |
1182 | copy = emit_barrier_before (loop_start); | |
1183 | break; | |
1184 | case NOTE: | |
1185 | /* Only copy line-number notes. */ | |
1186 | if (NOTE_LINE_NUMBER (insn) >= 0) | |
1187 | { | |
1188 | copy = emit_note_before (NOTE_LINE_NUMBER (insn), loop_start); | |
1189 | NOTE_SOURCE_FILE (copy) = NOTE_SOURCE_FILE (insn); | |
1190 | } | |
1191 | break; | |
7113a566 | 1192 | |
4e717234 | 1193 | case INSN: |
928d57e3 | 1194 | copy = emit_insn_before (copy_insn (PATTERN (insn)), loop_start); |
4e717234 | 1195 | if (reg_map) |
1196 | replace_regs (PATTERN (copy), reg_map, max_reg, 1); | |
7113a566 | 1197 | |
190099a6 | 1198 | mark_jump_label (PATTERN (copy), copy, 0, 0); |
7113a566 | 1199 | |
4e717234 | 1200 | /* Copy all REG_NOTES except REG_LABEL since mark_jump_label will |
1201 | make them. */ | |
1202 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
1203 | if (REG_NOTE_KIND (link) != REG_LABEL) | |
74b0991d | 1204 | { |
1205 | if (GET_CODE (link) == EXPR_LIST) | |
1206 | REG_NOTES (copy) | |
1207 | = copy_insn_1 (gen_rtx_EXPR_LIST (REG_NOTE_KIND (link), | |
1208 | XEXP (link, 0), | |
1209 | REG_NOTES (copy))); | |
1210 | else | |
1211 | REG_NOTES (copy) | |
1212 | = copy_insn_1 (gen_rtx_INSN_LIST (REG_NOTE_KIND (link), | |
1213 | XEXP (link, 0), | |
1214 | REG_NOTES (copy))); | |
1215 | } | |
1216 | ||
4e717234 | 1217 | if (reg_map && REG_NOTES (copy)) |
1218 | replace_regs (REG_NOTES (copy), reg_map, max_reg, 1); | |
1219 | break; | |
7113a566 | 1220 | |
4e717234 | 1221 | case JUMP_INSN: |
7113a566 | 1222 | copy = emit_jump_insn_before (copy_insn (PATTERN (insn)), |
1223 | loop_start); | |
4e717234 | 1224 | if (reg_map) |
1225 | replace_regs (PATTERN (copy), reg_map, max_reg, 1); | |
190099a6 | 1226 | mark_jump_label (PATTERN (copy), copy, 0, 0); |
4e717234 | 1227 | if (REG_NOTES (insn)) |
1228 | { | |
928d57e3 | 1229 | REG_NOTES (copy) = copy_insn_1 (REG_NOTES (insn)); |
4e717234 | 1230 | if (reg_map) |
1231 | replace_regs (REG_NOTES (copy), reg_map, max_reg, 1); | |
1232 | } | |
7113a566 | 1233 | |
4e717234 | 1234 | /* If this is a simple jump, add it to the jump chain. */ |
7113a566 | 1235 | |
4e717234 | 1236 | if (INSN_UID (copy) < max_jump_chain && JUMP_LABEL (copy) |
1237 | && simplejump_p (copy)) | |
1238 | { | |
1239 | jump_chain[INSN_UID (copy)] | |
1240 | = jump_chain[INSN_UID (JUMP_LABEL (copy))]; | |
1241 | jump_chain[INSN_UID (JUMP_LABEL (copy))] = copy; | |
1242 | } | |
1243 | break; | |
7113a566 | 1244 | |
4e717234 | 1245 | default: |
1246 | abort (); | |
1247 | } | |
5924de0b | 1248 | |
4e717234 | 1249 | /* Record the first insn we copied. We need it so that we can |
1250 | scan the copied insns for new pseudo registers. */ | |
1251 | if (! first_copy) | |
1252 | first_copy = copy; | |
1253 | } | |
5924de0b | 1254 | |
1255 | /* Now clean up by emitting a jump to the end label and deleting the jump | |
1256 | at the start of the loop. */ | |
b8778d98 | 1257 | if (! copy || GET_CODE (copy) != BARRIER) |
5924de0b | 1258 | { |
1259 | copy = emit_jump_insn_before (gen_jump (get_label_after (insn)), | |
1260 | loop_start); | |
4e717234 | 1261 | |
1262 | /* Record the first insn we copied. We need it so that we can | |
1263 | scan the copied insns for new pseudo registers. This may not | |
1264 | be strictly necessary since we should have copied at least one | |
1265 | insn above. But I am going to be safe. */ | |
1266 | if (! first_copy) | |
1267 | first_copy = copy; | |
1268 | ||
190099a6 | 1269 | mark_jump_label (PATTERN (copy), copy, 0, 0); |
5924de0b | 1270 | if (INSN_UID (copy) < max_jump_chain |
1271 | && INSN_UID (JUMP_LABEL (copy)) < max_jump_chain) | |
1272 | { | |
1273 | jump_chain[INSN_UID (copy)] | |
1274 | = jump_chain[INSN_UID (JUMP_LABEL (copy))]; | |
1275 | jump_chain[INSN_UID (JUMP_LABEL (copy))] = copy; | |
1276 | } | |
1277 | emit_barrier_before (loop_start); | |
1278 | } | |
1279 | ||
4e717234 | 1280 | /* Now scan from the first insn we copied to the last insn we copied |
1281 | (copy) for new pseudo registers. Do this after the code to jump to | |
1282 | the end label since that might create a new pseudo too. */ | |
1283 | reg_scan_update (first_copy, copy, max_reg); | |
1284 | ||
5924de0b | 1285 | /* Mark the exit code as the virtual top of the converted loop. */ |
1286 | emit_note_before (NOTE_INSN_LOOP_VTOP, exitcode); | |
1287 | ||
92d3c3ad | 1288 | delete_insn (next_nonnote_insn (loop_start)); |
7113a566 | 1289 | |
8b861be4 | 1290 | /* Clean up. */ |
1291 | if (reg_map) | |
1292 | free (reg_map); | |
92d3c3ad | 1293 | |
5924de0b | 1294 | return 1; |
1295 | } | |
1296 | \f | |
74b0991d | 1297 | /* Move all block-beg, block-end, loop-beg, loop-cont, loop-vtop, loop-end, |
1298 | eh-beg, eh-end notes between START and END out before START. Assume that | |
d2d45541 | 1299 | END is not such a note. START may be such a note. Returns the value |
1300 | of the new starting insn, which may be different if the original start | |
1301 | was such a note. */ | |
5924de0b | 1302 | |
d2d45541 | 1303 | rtx |
5924de0b | 1304 | squeeze_notes (start, end) |
1305 | rtx start, end; | |
1306 | { | |
1307 | rtx insn; | |
1308 | rtx next; | |
1309 | ||
1310 | for (insn = start; insn != end; insn = next) | |
1311 | { | |
1312 | next = NEXT_INSN (insn); | |
1313 | if (GET_CODE (insn) == NOTE | |
1314 | && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END | |
1315 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG | |
1316 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG | |
1317 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END | |
1318 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_CONT | |
74b0991d | 1319 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_VTOP |
1320 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG | |
1321 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)) | |
5924de0b | 1322 | { |
d2d45541 | 1323 | if (insn == start) |
1324 | start = next; | |
1325 | else | |
1326 | { | |
1327 | rtx prev = PREV_INSN (insn); | |
1328 | PREV_INSN (insn) = PREV_INSN (start); | |
1329 | NEXT_INSN (insn) = start; | |
1330 | NEXT_INSN (PREV_INSN (insn)) = insn; | |
1331 | PREV_INSN (NEXT_INSN (insn)) = insn; | |
1332 | NEXT_INSN (prev) = next; | |
1333 | PREV_INSN (next) = prev; | |
1334 | } | |
5924de0b | 1335 | } |
1336 | } | |
d2d45541 | 1337 | |
1338 | return start; | |
5924de0b | 1339 | } |
1340 | \f | |
1341 | /* Compare the instructions before insn E1 with those before E2 | |
1342 | to find an opportunity for cross jumping. | |
1343 | (This means detecting identical sequences of insns followed by | |
1344 | jumps to the same place, or followed by a label and a jump | |
1345 | to that label, and replacing one with a jump to the other.) | |
1346 | ||
1347 | Assume E1 is a jump that jumps to label E2 | |
1348 | (that is not always true but it might as well be). | |
1349 | Find the longest possible equivalent sequences | |
1350 | and store the first insns of those sequences into *F1 and *F2. | |
1351 | Store zero there if no equivalent preceding instructions are found. | |
1352 | ||
1353 | We give up if we find a label in stream 1. | |
1354 | Actually we could transfer that label into stream 2. */ | |
1355 | ||
1356 | static void | |
1357 | find_cross_jump (e1, e2, minimum, f1, f2) | |
1358 | rtx e1, e2; | |
1359 | int minimum; | |
1360 | rtx *f1, *f2; | |
1361 | { | |
1362 | register rtx i1 = e1, i2 = e2; | |
1363 | register rtx p1, p2; | |
1364 | int lose = 0; | |
1365 | ||
1366 | rtx last1 = 0, last2 = 0; | |
1367 | rtx afterlast1 = 0, afterlast2 = 0; | |
5924de0b | 1368 | |
1369 | *f1 = 0; | |
1370 | *f2 = 0; | |
1371 | ||
1372 | while (1) | |
1373 | { | |
1374 | i1 = prev_nonnote_insn (i1); | |
1375 | ||
1376 | i2 = PREV_INSN (i2); | |
1377 | while (i2 && (GET_CODE (i2) == NOTE || GET_CODE (i2) == CODE_LABEL)) | |
1378 | i2 = PREV_INSN (i2); | |
1379 | ||
1380 | if (i1 == 0) | |
1381 | break; | |
1382 | ||
1383 | /* Don't allow the range of insns preceding E1 or E2 | |
1384 | to include the other (E2 or E1). */ | |
1385 | if (i2 == e1 || i1 == e2) | |
1386 | break; | |
1387 | ||
1388 | /* If we will get to this code by jumping, those jumps will be | |
1389 | tensioned to go directly to the new label (before I2), | |
1390 | so this cross-jumping won't cost extra. So reduce the minimum. */ | |
1391 | if (GET_CODE (i1) == CODE_LABEL) | |
1392 | { | |
1393 | --minimum; | |
1394 | break; | |
1395 | } | |
1396 | ||
1397 | if (i2 == 0 || GET_CODE (i1) != GET_CODE (i2)) | |
1398 | break; | |
1399 | ||
fa924cfb | 1400 | /* Avoid moving insns across EH regions if either of the insns |
1401 | can throw. */ | |
1402 | if (flag_exceptions | |
1403 | && (asynchronous_exceptions || GET_CODE (i1) == CALL_INSN) | |
1404 | && !in_same_eh_region (i1, i2)) | |
1405 | break; | |
1406 | ||
5924de0b | 1407 | p1 = PATTERN (i1); |
1408 | p2 = PATTERN (i2); | |
7113a566 | 1409 | |
73b36b50 | 1410 | /* If this is a CALL_INSN, compare register usage information. |
1411 | If we don't check this on stack register machines, the two | |
1412 | CALL_INSNs might be merged leaving reg-stack.c with mismatching | |
1413 | numbers of stack registers in the same basic block. | |
1414 | If we don't check this on machines with delay slots, a delay slot may | |
1415 | be filled that clobbers a parameter expected by the subroutine. | |
b433f129 | 1416 | |
73b36b50 | 1417 | ??? We take the simple route for now and assume that if they're |
1418 | equal, they were constructed identically. */ | |
1419 | ||
1420 | if (GET_CODE (i1) == CALL_INSN | |
1421 | && ! rtx_equal_p (CALL_INSN_FUNCTION_USAGE (i1), | |
1422 | CALL_INSN_FUNCTION_USAGE (i2))) | |
1423 | lose = 1; | |
1424 | ||
1425 | #ifdef STACK_REGS | |
5924de0b | 1426 | /* If cross_jump_death_matters is not 0, the insn's mode |
1427 | indicates whether or not the insn contains any stack-like | |
a92771b8 | 1428 | regs. */ |
5924de0b | 1429 | |
b67ec609 | 1430 | if (!lose && cross_jump_death_matters && stack_regs_mentioned (i1)) |
5924de0b | 1431 | { |
1432 | /* If register stack conversion has already been done, then | |
1433 | death notes must also be compared before it is certain that | |
a92771b8 | 1434 | the two instruction streams match. */ |
5924de0b | 1435 | |
1436 | rtx note; | |
1437 | HARD_REG_SET i1_regset, i2_regset; | |
1438 | ||
1439 | CLEAR_HARD_REG_SET (i1_regset); | |
1440 | CLEAR_HARD_REG_SET (i2_regset); | |
1441 | ||
1442 | for (note = REG_NOTES (i1); note; note = XEXP (note, 1)) | |
1443 | if (REG_NOTE_KIND (note) == REG_DEAD | |
1444 | && STACK_REG_P (XEXP (note, 0))) | |
1445 | SET_HARD_REG_BIT (i1_regset, REGNO (XEXP (note, 0))); | |
1446 | ||
1447 | for (note = REG_NOTES (i2); note; note = XEXP (note, 1)) | |
1448 | if (REG_NOTE_KIND (note) == REG_DEAD | |
1449 | && STACK_REG_P (XEXP (note, 0))) | |
1450 | SET_HARD_REG_BIT (i2_regset, REGNO (XEXP (note, 0))); | |
1451 | ||
1452 | GO_IF_HARD_REG_EQUAL (i1_regset, i2_regset, done); | |
1453 | ||
1454 | lose = 1; | |
1455 | ||
1456 | done: | |
1457 | ; | |
1458 | } | |
1459 | #endif | |
1460 | ||
b65d0152 | 1461 | /* Don't allow old-style asm or volatile extended asms to be accepted |
1462 | for cross jumping purposes. It is conceptually correct to allow | |
1463 | them, since cross-jumping preserves the dynamic instruction order | |
1464 | even though it is changing the static instruction order. However, | |
1465 | if an asm is being used to emit an assembler pseudo-op, such as | |
1466 | the MIPS `.set reorder' pseudo-op, then the static instruction order | |
1467 | matters and it must be preserved. */ | |
1468 | if (GET_CODE (p1) == ASM_INPUT || GET_CODE (p2) == ASM_INPUT | |
1469 | || (GET_CODE (p1) == ASM_OPERANDS && MEM_VOLATILE_P (p1)) | |
1470 | || (GET_CODE (p2) == ASM_OPERANDS && MEM_VOLATILE_P (p2))) | |
1471 | lose = 1; | |
1472 | ||
1473 | if (lose || GET_CODE (p1) != GET_CODE (p2) | |
5924de0b | 1474 | || ! rtx_renumbered_equal_p (p1, p2)) |
1475 | { | |
1476 | /* The following code helps take care of G++ cleanups. */ | |
1477 | rtx equiv1; | |
1478 | rtx equiv2; | |
1479 | ||
1480 | if (!lose && GET_CODE (p1) == GET_CODE (p2) | |
1bb04728 | 1481 | && ((equiv1 = find_reg_note (i1, REG_EQUAL, NULL_RTX)) != 0 |
1482 | || (equiv1 = find_reg_note (i1, REG_EQUIV, NULL_RTX)) != 0) | |
1483 | && ((equiv2 = find_reg_note (i2, REG_EQUAL, NULL_RTX)) != 0 | |
1484 | || (equiv2 = find_reg_note (i2, REG_EQUIV, NULL_RTX)) != 0) | |
5924de0b | 1485 | /* If the equivalences are not to a constant, they may |
1486 | reference pseudos that no longer exist, so we can't | |
1487 | use them. */ | |
1488 | && CONSTANT_P (XEXP (equiv1, 0)) | |
1489 | && rtx_equal_p (XEXP (equiv1, 0), XEXP (equiv2, 0))) | |
1490 | { | |
1491 | rtx s1 = single_set (i1); | |
1492 | rtx s2 = single_set (i2); | |
1493 | if (s1 != 0 && s2 != 0 | |
1494 | && rtx_renumbered_equal_p (SET_DEST (s1), SET_DEST (s2))) | |
1495 | { | |
1496 | validate_change (i1, &SET_SRC (s1), XEXP (equiv1, 0), 1); | |
1497 | validate_change (i2, &SET_SRC (s2), XEXP (equiv2, 0), 1); | |
1498 | if (! rtx_renumbered_equal_p (p1, p2)) | |
1499 | cancel_changes (0); | |
1500 | else if (apply_change_group ()) | |
1501 | goto win; | |
1502 | } | |
1503 | } | |
1504 | ||
1505 | /* Insns fail to match; cross jumping is limited to the following | |
1506 | insns. */ | |
1507 | ||
1508 | #ifdef HAVE_cc0 | |
1509 | /* Don't allow the insn after a compare to be shared by | |
1510 | cross-jumping unless the compare is also shared. | |
1511 | Here, if either of these non-matching insns is a compare, | |
1512 | exclude the following insn from possible cross-jumping. */ | |
1513 | if (sets_cc0_p (p1) || sets_cc0_p (p2)) | |
1514 | last1 = afterlast1, last2 = afterlast2, ++minimum; | |
1515 | #endif | |
1516 | ||
1517 | /* If cross-jumping here will feed a jump-around-jump | |
1518 | optimization, this jump won't cost extra, so reduce | |
1519 | the minimum. */ | |
1520 | if (GET_CODE (i1) == JUMP_INSN | |
1521 | && JUMP_LABEL (i1) | |
1522 | && prev_real_insn (JUMP_LABEL (i1)) == e1) | |
1523 | --minimum; | |
1524 | break; | |
1525 | } | |
1526 | ||
1527 | win: | |
1528 | if (GET_CODE (p1) != USE && GET_CODE (p1) != CLOBBER) | |
1529 | { | |
1530 | /* Ok, this insn is potentially includable in a cross-jump here. */ | |
1531 | afterlast1 = last1, afterlast2 = last2; | |
1532 | last1 = i1, last2 = i2, --minimum; | |
1533 | } | |
1534 | } | |
1535 | ||
5924de0b | 1536 | if (minimum <= 0 && last1 != 0 && last1 != e1) |
1537 | *f1 = last1, *f2 = last2; | |
1538 | } | |
1539 | ||
1540 | static void | |
1541 | do_cross_jump (insn, newjpos, newlpos) | |
1542 | rtx insn, newjpos, newlpos; | |
1543 | { | |
1544 | /* Find an existing label at this point | |
1545 | or make a new one if there is none. */ | |
1546 | register rtx label = get_label_before (newlpos); | |
1547 | ||
1548 | /* Make the same jump insn jump to the new point. */ | |
1549 | if (GET_CODE (PATTERN (insn)) == RETURN) | |
1550 | { | |
1551 | /* Remove from jump chain of returns. */ | |
1552 | delete_from_jump_chain (insn); | |
1553 | /* Change the insn. */ | |
1554 | PATTERN (insn) = gen_jump (label); | |
1555 | INSN_CODE (insn) = -1; | |
1556 | JUMP_LABEL (insn) = label; | |
1557 | LABEL_NUSES (label)++; | |
1558 | /* Add to new the jump chain. */ | |
1559 | if (INSN_UID (label) < max_jump_chain | |
1560 | && INSN_UID (insn) < max_jump_chain) | |
1561 | { | |
1562 | jump_chain[INSN_UID (insn)] = jump_chain[INSN_UID (label)]; | |
1563 | jump_chain[INSN_UID (label)] = insn; | |
1564 | } | |
1565 | } | |
1566 | else | |
f8cacb57 | 1567 | redirect_jump (insn, label, 1); |
5924de0b | 1568 | |
1569 | /* Delete the matching insns before the jump. Also, remove any REG_EQUAL | |
1570 | or REG_EQUIV note in the NEWLPOS stream that isn't also present in | |
1571 | the NEWJPOS stream. */ | |
1572 | ||
1573 | while (newjpos != insn) | |
1574 | { | |
1575 | rtx lnote; | |
1576 | ||
1577 | for (lnote = REG_NOTES (newlpos); lnote; lnote = XEXP (lnote, 1)) | |
1578 | if ((REG_NOTE_KIND (lnote) == REG_EQUAL | |
1579 | || REG_NOTE_KIND (lnote) == REG_EQUIV) | |
1580 | && ! find_reg_note (newjpos, REG_EQUAL, XEXP (lnote, 0)) | |
1581 | && ! find_reg_note (newjpos, REG_EQUIV, XEXP (lnote, 0))) | |
1582 | remove_note (newlpos, lnote); | |
1583 | ||
1584 | delete_insn (newjpos); | |
1585 | newjpos = next_real_insn (newjpos); | |
1586 | newlpos = next_real_insn (newlpos); | |
1587 | } | |
1588 | } | |
1589 | \f | |
1590 | /* Return the label before INSN, or put a new label there. */ | |
1591 | ||
1592 | rtx | |
1593 | get_label_before (insn) | |
1594 | rtx insn; | |
1595 | { | |
1596 | rtx label; | |
1597 | ||
1598 | /* Find an existing label at this point | |
1599 | or make a new one if there is none. */ | |
1600 | label = prev_nonnote_insn (insn); | |
1601 | ||
1602 | if (label == 0 || GET_CODE (label) != CODE_LABEL) | |
1603 | { | |
1604 | rtx prev = PREV_INSN (insn); | |
1605 | ||
5924de0b | 1606 | label = gen_label_rtx (); |
1607 | emit_label_after (label, prev); | |
1608 | LABEL_NUSES (label) = 0; | |
1609 | } | |
1610 | return label; | |
1611 | } | |
1612 | ||
1613 | /* Return the label after INSN, or put a new label there. */ | |
1614 | ||
1615 | rtx | |
1616 | get_label_after (insn) | |
1617 | rtx insn; | |
1618 | { | |
1619 | rtx label; | |
1620 | ||
1621 | /* Find an existing label at this point | |
1622 | or make a new one if there is none. */ | |
1623 | label = next_nonnote_insn (insn); | |
1624 | ||
1625 | if (label == 0 || GET_CODE (label) != CODE_LABEL) | |
1626 | { | |
5924de0b | 1627 | label = gen_label_rtx (); |
1628 | emit_label_after (label, insn); | |
1629 | LABEL_NUSES (label) = 0; | |
1630 | } | |
1631 | return label; | |
1632 | } | |
1633 | \f | |
1634 | /* Return 1 if INSN is a jump that jumps to right after TARGET | |
1635 | only on the condition that TARGET itself would drop through. | |
1636 | Assumes that TARGET is a conditional jump. */ | |
1637 | ||
1638 | static int | |
1639 | jump_back_p (insn, target) | |
1640 | rtx insn, target; | |
1641 | { | |
1642 | rtx cinsn, ctarget; | |
1643 | enum rtx_code codei, codet; | |
ba08b7e7 | 1644 | rtx set, tset; |
5924de0b | 1645 | |
ba08b7e7 | 1646 | if (! any_condjump_p (insn) |
1647 | || any_uncondjump_p (target) | |
5924de0b | 1648 | || target != prev_real_insn (JUMP_LABEL (insn))) |
1649 | return 0; | |
ba08b7e7 | 1650 | set = pc_set (insn); |
1651 | tset = pc_set (target); | |
5924de0b | 1652 | |
ba08b7e7 | 1653 | cinsn = XEXP (SET_SRC (set), 0); |
1654 | ctarget = XEXP (SET_SRC (tset), 0); | |
5924de0b | 1655 | |
1656 | codei = GET_CODE (cinsn); | |
1657 | codet = GET_CODE (ctarget); | |
1658 | ||
ba08b7e7 | 1659 | if (XEXP (SET_SRC (set), 1) == pc_rtx) |
5924de0b | 1660 | { |
1661 | if (! can_reverse_comparison_p (cinsn, insn)) | |
1662 | return 0; | |
1663 | codei = reverse_condition (codei); | |
1664 | } | |
1665 | ||
ba08b7e7 | 1666 | if (XEXP (SET_SRC (tset), 2) == pc_rtx) |
5924de0b | 1667 | { |
1668 | if (! can_reverse_comparison_p (ctarget, target)) | |
1669 | return 0; | |
1670 | codet = reverse_condition (codet); | |
1671 | } | |
1672 | ||
1673 | return (codei == codet | |
1674 | && rtx_renumbered_equal_p (XEXP (cinsn, 0), XEXP (ctarget, 0)) | |
1675 | && rtx_renumbered_equal_p (XEXP (cinsn, 1), XEXP (ctarget, 1))); | |
1676 | } | |
1677 | \f | |
1678 | /* Given a comparison, COMPARISON, inside a conditional jump insn, INSN, | |
1679 | return non-zero if it is safe to reverse this comparison. It is if our | |
1680 | floating-point is not IEEE, if this is an NE or EQ comparison, or if | |
1681 | this is known to be an integer comparison. */ | |
1682 | ||
1683 | int | |
1684 | can_reverse_comparison_p (comparison, insn) | |
1685 | rtx comparison; | |
1686 | rtx insn; | |
1687 | { | |
1688 | rtx arg0; | |
1689 | ||
1690 | /* If this is not actually a comparison, we can't reverse it. */ | |
1691 | if (GET_RTX_CLASS (GET_CODE (comparison)) != '<') | |
1692 | return 0; | |
1693 | ||
1694 | if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT | |
1695 | /* If this is an NE comparison, it is safe to reverse it to an EQ | |
1696 | comparison and vice versa, even for floating point. If no operands | |
1697 | are NaNs, the reversal is valid. If some operand is a NaN, EQ is | |
1698 | always false and NE is always true, so the reversal is also valid. */ | |
5addad0a | 1699 | || flag_fast_math |
5924de0b | 1700 | || GET_CODE (comparison) == NE |
1701 | || GET_CODE (comparison) == EQ) | |
1702 | return 1; | |
1703 | ||
1704 | arg0 = XEXP (comparison, 0); | |
1705 | ||
1706 | /* Make sure ARG0 is one of the actual objects being compared. If we | |
7113a566 | 1707 | can't do this, we can't be sure the comparison can be reversed. |
5924de0b | 1708 | |
1709 | Handle cc0 and a MODE_CC register. */ | |
1710 | if ((GET_CODE (arg0) == REG && GET_MODE_CLASS (GET_MODE (arg0)) == MODE_CC) | |
1711 | #ifdef HAVE_cc0 | |
1712 | || arg0 == cc0_rtx | |
1713 | #endif | |
1714 | ) | |
1715 | { | |
111f2389 | 1716 | rtx prev, set; |
5924de0b | 1717 | |
7014838c | 1718 | /* First see if the condition code mode alone if enough to say we can |
1719 | reverse the condition. If not, then search backwards for a set of | |
1720 | ARG0. We do not need to check for an insn clobbering it since valid | |
1721 | code will contain set a set with no intervening clobber. But | |
1722 | stop when we reach a label. */ | |
1723 | #ifdef REVERSIBLE_CC_MODE | |
1724 | if (GET_MODE_CLASS (GET_MODE (arg0)) == MODE_CC | |
1725 | && REVERSIBLE_CC_MODE (GET_MODE (arg0))) | |
1726 | return 1; | |
1727 | #endif | |
111f2389 | 1728 | |
1729 | if (! insn) | |
1730 | return 0; | |
7113a566 | 1731 | |
7014838c | 1732 | for (prev = prev_nonnote_insn (insn); |
1733 | prev != 0 && GET_CODE (prev) != CODE_LABEL; | |
1734 | prev = prev_nonnote_insn (prev)) | |
1735 | if ((set = single_set (prev)) != 0 | |
1736 | && rtx_equal_p (SET_DEST (set), arg0)) | |
1737 | { | |
1738 | arg0 = SET_SRC (set); | |
5924de0b | 1739 | |
7014838c | 1740 | if (GET_CODE (arg0) == COMPARE) |
1741 | arg0 = XEXP (arg0, 0); | |
1742 | break; | |
1743 | } | |
5924de0b | 1744 | } |
1745 | ||
1746 | /* We can reverse this if ARG0 is a CONST_INT or if its mode is | |
1747 | not VOIDmode and neither a MODE_CC nor MODE_FLOAT type. */ | |
1748 | return (GET_CODE (arg0) == CONST_INT | |
1749 | || (GET_MODE (arg0) != VOIDmode | |
1750 | && GET_MODE_CLASS (GET_MODE (arg0)) != MODE_CC | |
1751 | && GET_MODE_CLASS (GET_MODE (arg0)) != MODE_FLOAT)); | |
1752 | } | |
1753 | ||
a4110d9a | 1754 | /* Given an rtx-code for a comparison, return the code for the negated |
1755 | comparison. If no such code exists, return UNKNOWN. | |
1756 | ||
1757 | WATCH OUT! reverse_condition is not safe to use on a jump that might | |
1758 | be acting on the results of an IEEE floating point comparison, because | |
7113a566 | 1759 | of the special treatment of non-signaling nans in comparisons. |
5924de0b | 1760 | Use can_reverse_comparison_p to be sure. */ |
1761 | ||
1762 | enum rtx_code | |
1763 | reverse_condition (code) | |
1764 | enum rtx_code code; | |
1765 | { | |
1766 | switch (code) | |
1767 | { | |
1768 | case EQ: | |
1769 | return NE; | |
5924de0b | 1770 | case NE: |
1771 | return EQ; | |
5924de0b | 1772 | case GT: |
1773 | return LE; | |
5924de0b | 1774 | case GE: |
1775 | return LT; | |
5924de0b | 1776 | case LT: |
1777 | return GE; | |
5924de0b | 1778 | case LE: |
1779 | return GT; | |
5924de0b | 1780 | case GTU: |
1781 | return LEU; | |
5924de0b | 1782 | case GEU: |
1783 | return LTU; | |
5924de0b | 1784 | case LTU: |
1785 | return GEU; | |
5924de0b | 1786 | case LEU: |
1787 | return GTU; | |
a4110d9a | 1788 | case UNORDERED: |
1789 | return ORDERED; | |
1790 | case ORDERED: | |
1791 | return UNORDERED; | |
1792 | ||
1793 | case UNLT: | |
1794 | case UNLE: | |
1795 | case UNGT: | |
1796 | case UNGE: | |
1797 | case UNEQ: | |
79777bad | 1798 | case LTGT: |
a4110d9a | 1799 | return UNKNOWN; |
5924de0b | 1800 | |
1801 | default: | |
1802 | abort (); | |
5924de0b | 1803 | } |
1804 | } | |
1805 | ||
79777bad | 1806 | /* Similar, but we're allowed to generate unordered comparisons, which |
1807 | makes it safe for IEEE floating-point. Of course, we have to recognize | |
1808 | that the target will support them too... */ | |
1809 | ||
1810 | enum rtx_code | |
1811 | reverse_condition_maybe_unordered (code) | |
1812 | enum rtx_code code; | |
1813 | { | |
1814 | /* Non-IEEE formats don't have unordered conditions. */ | |
1815 | if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT) | |
1816 | return reverse_condition (code); | |
1817 | ||
1818 | switch (code) | |
1819 | { | |
1820 | case EQ: | |
1821 | return NE; | |
1822 | case NE: | |
1823 | return EQ; | |
1824 | case GT: | |
1825 | return UNLE; | |
1826 | case GE: | |
1827 | return UNLT; | |
1828 | case LT: | |
1829 | return UNGE; | |
1830 | case LE: | |
1831 | return UNGT; | |
1832 | case LTGT: | |
1833 | return UNEQ; | |
1834 | case GTU: | |
1835 | return LEU; | |
1836 | case GEU: | |
1837 | return LTU; | |
1838 | case LTU: | |
1839 | return GEU; | |
1840 | case LEU: | |
1841 | return GTU; | |
1842 | case UNORDERED: | |
1843 | return ORDERED; | |
1844 | case ORDERED: | |
1845 | return UNORDERED; | |
1846 | case UNLT: | |
1847 | return GE; | |
1848 | case UNLE: | |
1849 | return GT; | |
1850 | case UNGT: | |
1851 | return LE; | |
1852 | case UNGE: | |
1853 | return LT; | |
1854 | case UNEQ: | |
1855 | return LTGT; | |
1856 | ||
1857 | default: | |
1858 | abort (); | |
1859 | } | |
1860 | } | |
1861 | ||
5924de0b | 1862 | /* Similar, but return the code when two operands of a comparison are swapped. |
1863 | This IS safe for IEEE floating-point. */ | |
1864 | ||
1865 | enum rtx_code | |
1866 | swap_condition (code) | |
1867 | enum rtx_code code; | |
1868 | { | |
1869 | switch (code) | |
1870 | { | |
1871 | case EQ: | |
1872 | case NE: | |
a4110d9a | 1873 | case UNORDERED: |
1874 | case ORDERED: | |
1875 | case UNEQ: | |
79777bad | 1876 | case LTGT: |
5924de0b | 1877 | return code; |
1878 | ||
1879 | case GT: | |
1880 | return LT; | |
5924de0b | 1881 | case GE: |
1882 | return LE; | |
5924de0b | 1883 | case LT: |
1884 | return GT; | |
5924de0b | 1885 | case LE: |
1886 | return GE; | |
5924de0b | 1887 | case GTU: |
1888 | return LTU; | |
5924de0b | 1889 | case GEU: |
1890 | return LEU; | |
5924de0b | 1891 | case LTU: |
1892 | return GTU; | |
5924de0b | 1893 | case LEU: |
1894 | return GEU; | |
a4110d9a | 1895 | case UNLT: |
1896 | return UNGT; | |
1897 | case UNLE: | |
1898 | return UNGE; | |
1899 | case UNGT: | |
1900 | return UNLT; | |
1901 | case UNGE: | |
1902 | return UNLE; | |
1903 | ||
5924de0b | 1904 | default: |
1905 | abort (); | |
5924de0b | 1906 | } |
1907 | } | |
1908 | ||
1909 | /* Given a comparison CODE, return the corresponding unsigned comparison. | |
1910 | If CODE is an equality comparison or already an unsigned comparison, | |
1911 | CODE is returned. */ | |
1912 | ||
1913 | enum rtx_code | |
1914 | unsigned_condition (code) | |
1915 | enum rtx_code code; | |
1916 | { | |
1917 | switch (code) | |
1918 | { | |
1919 | case EQ: | |
1920 | case NE: | |
1921 | case GTU: | |
1922 | case GEU: | |
1923 | case LTU: | |
1924 | case LEU: | |
1925 | return code; | |
1926 | ||
1927 | case GT: | |
1928 | return GTU; | |
5924de0b | 1929 | case GE: |
1930 | return GEU; | |
5924de0b | 1931 | case LT: |
1932 | return LTU; | |
5924de0b | 1933 | case LE: |
1934 | return LEU; | |
1935 | ||
1936 | default: | |
1937 | abort (); | |
1938 | } | |
1939 | } | |
1940 | ||
1941 | /* Similarly, return the signed version of a comparison. */ | |
1942 | ||
1943 | enum rtx_code | |
1944 | signed_condition (code) | |
1945 | enum rtx_code code; | |
1946 | { | |
1947 | switch (code) | |
1948 | { | |
1949 | case EQ: | |
1950 | case NE: | |
1951 | case GT: | |
1952 | case GE: | |
1953 | case LT: | |
1954 | case LE: | |
1955 | return code; | |
1956 | ||
1957 | case GTU: | |
1958 | return GT; | |
5924de0b | 1959 | case GEU: |
1960 | return GE; | |
5924de0b | 1961 | case LTU: |
1962 | return LT; | |
5924de0b | 1963 | case LEU: |
1964 | return LE; | |
1965 | ||
1966 | default: | |
1967 | abort (); | |
1968 | } | |
1969 | } | |
1970 | \f | |
1971 | /* Return non-zero if CODE1 is more strict than CODE2, i.e., if the | |
1972 | truth of CODE1 implies the truth of CODE2. */ | |
1973 | ||
1974 | int | |
1975 | comparison_dominates_p (code1, code2) | |
1976 | enum rtx_code code1, code2; | |
1977 | { | |
1978 | if (code1 == code2) | |
1979 | return 1; | |
1980 | ||
1981 | switch (code1) | |
1982 | { | |
1983 | case EQ: | |
79777bad | 1984 | if (code2 == LE || code2 == LEU || code2 == GE || code2 == GEU |
1985 | || code2 == ORDERED) | |
5924de0b | 1986 | return 1; |
1987 | break; | |
1988 | ||
1989 | case LT: | |
79777bad | 1990 | if (code2 == LE || code2 == NE || code2 == ORDERED) |
5924de0b | 1991 | return 1; |
1992 | break; | |
1993 | ||
1994 | case GT: | |
79777bad | 1995 | if (code2 == GE || code2 == NE || code2 == ORDERED) |
1996 | return 1; | |
1997 | break; | |
1998 | ||
1999 | case GE: | |
2000 | case LE: | |
2001 | if (code2 == ORDERED) | |
2002 | return 1; | |
2003 | break; | |
2004 | ||
2005 | case LTGT: | |
2006 | if (code2 == NE || code2 == ORDERED) | |
5924de0b | 2007 | return 1; |
2008 | break; | |
2009 | ||
2010 | case LTU: | |
11088b43 | 2011 | if (code2 == LEU || code2 == NE) |
5924de0b | 2012 | return 1; |
2013 | break; | |
2014 | ||
2015 | case GTU: | |
11088b43 | 2016 | if (code2 == GEU || code2 == NE) |
5924de0b | 2017 | return 1; |
2018 | break; | |
79777bad | 2019 | |
2020 | case UNORDERED: | |
2021 | if (code2 == NE) | |
2022 | return 1; | |
2023 | break; | |
7113a566 | 2024 | |
0dbd1c74 | 2025 | default: |
2026 | break; | |
5924de0b | 2027 | } |
2028 | ||
2029 | return 0; | |
2030 | } | |
2031 | \f | |
2032 | /* Return 1 if INSN is an unconditional jump and nothing else. */ | |
2033 | ||
2034 | int | |
2035 | simplejump_p (insn) | |
2036 | rtx insn; | |
2037 | { | |
2038 | return (GET_CODE (insn) == JUMP_INSN | |
2039 | && GET_CODE (PATTERN (insn)) == SET | |
2040 | && GET_CODE (SET_DEST (PATTERN (insn))) == PC | |
2041 | && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF); | |
2042 | } | |
2043 | ||
2044 | /* Return nonzero if INSN is a (possibly) conditional jump | |
7113a566 | 2045 | and nothing more. |
2046 | ||
d670e794 | 2047 | Use this function is deprecated, since we need to support combined |
2048 | branch and compare insns. Use any_condjump_p instead whenever possible. */ | |
5924de0b | 2049 | |
2050 | int | |
2051 | condjump_p (insn) | |
2052 | rtx insn; | |
2053 | { | |
2054 | register rtx x = PATTERN (insn); | |
7014838c | 2055 | |
2056 | if (GET_CODE (x) != SET | |
2057 | || GET_CODE (SET_DEST (x)) != PC) | |
4fbe8fa7 | 2058 | return 0; |
7014838c | 2059 | |
2060 | x = SET_SRC (x); | |
2061 | if (GET_CODE (x) == LABEL_REF) | |
4fbe8fa7 | 2062 | return 1; |
7113a566 | 2063 | else |
2064 | return (GET_CODE (x) == IF_THEN_ELSE | |
2065 | && ((GET_CODE (XEXP (x, 2)) == PC | |
2066 | && (GET_CODE (XEXP (x, 1)) == LABEL_REF | |
2067 | || GET_CODE (XEXP (x, 1)) == RETURN)) | |
2068 | || (GET_CODE (XEXP (x, 1)) == PC | |
2069 | && (GET_CODE (XEXP (x, 2)) == LABEL_REF | |
2070 | || GET_CODE (XEXP (x, 2)) == RETURN)))); | |
7014838c | 2071 | |
4fbe8fa7 | 2072 | return 0; |
2073 | } | |
2074 | ||
7014838c | 2075 | /* Return nonzero if INSN is a (possibly) conditional jump inside a |
3a941ad5 | 2076 | PARALLEL. |
7113a566 | 2077 | |
d670e794 | 2078 | Use this function is deprecated, since we need to support combined |
2079 | branch and compare insns. Use any_condjump_p instead whenever possible. */ | |
4fbe8fa7 | 2080 | |
2081 | int | |
2082 | condjump_in_parallel_p (insn) | |
2083 | rtx insn; | |
2084 | { | |
2085 | register rtx x = PATTERN (insn); | |
2086 | ||
2087 | if (GET_CODE (x) != PARALLEL) | |
2088 | return 0; | |
2089 | else | |
2090 | x = XVECEXP (x, 0, 0); | |
2091 | ||
5924de0b | 2092 | if (GET_CODE (x) != SET) |
2093 | return 0; | |
2094 | if (GET_CODE (SET_DEST (x)) != PC) | |
2095 | return 0; | |
2096 | if (GET_CODE (SET_SRC (x)) == LABEL_REF) | |
2097 | return 1; | |
2098 | if (GET_CODE (SET_SRC (x)) != IF_THEN_ELSE) | |
2099 | return 0; | |
2100 | if (XEXP (SET_SRC (x), 2) == pc_rtx | |
2101 | && (GET_CODE (XEXP (SET_SRC (x), 1)) == LABEL_REF | |
2102 | || GET_CODE (XEXP (SET_SRC (x), 1)) == RETURN)) | |
2103 | return 1; | |
2104 | if (XEXP (SET_SRC (x), 1) == pc_rtx | |
2105 | && (GET_CODE (XEXP (SET_SRC (x), 2)) == LABEL_REF | |
2106 | || GET_CODE (XEXP (SET_SRC (x), 2)) == RETURN)) | |
2107 | return 1; | |
2108 | return 0; | |
2109 | } | |
2110 | ||
d670e794 | 2111 | /* Return set of PC, otherwise NULL. */ |
2112 | ||
3a941ad5 | 2113 | rtx |
2114 | pc_set (insn) | |
2115 | rtx insn; | |
2116 | { | |
2117 | rtx pat; | |
2118 | if (GET_CODE (insn) != JUMP_INSN) | |
d670e794 | 2119 | return NULL_RTX; |
3a941ad5 | 2120 | pat = PATTERN (insn); |
d670e794 | 2121 | |
2122 | /* The set is allowed to appear either as the insn pattern or | |
2123 | the first set in a PARALLEL. */ | |
2124 | if (GET_CODE (pat) == PARALLEL) | |
2125 | pat = XVECEXP (pat, 0, 0); | |
3a941ad5 | 2126 | if (GET_CODE (pat) == SET && GET_CODE (SET_DEST (pat)) == PC) |
2127 | return pat; | |
d670e794 | 2128 | |
2129 | return NULL_RTX; | |
3a941ad5 | 2130 | } |
2131 | ||
d670e794 | 2132 | /* Return true when insn is an unconditional direct jump, |
2133 | possibly bundled inside a PARALLEL. */ | |
2134 | ||
3a941ad5 | 2135 | int |
2136 | any_uncondjump_p (insn) | |
2137 | rtx insn; | |
2138 | { | |
2139 | rtx x = pc_set (insn); | |
2140 | if (!x) | |
2141 | return 0; | |
2142 | if (GET_CODE (SET_SRC (x)) != LABEL_REF) | |
2143 | return 0; | |
2144 | return 1; | |
2145 | } | |
2146 | ||
d670e794 | 2147 | /* Return true when insn is a conditional jump. This function works for |
3a941ad5 | 2148 | instructions containing PC sets in PARALLELs. The instruction may have |
2149 | various other effects so before removing the jump you must verify | |
9641f63c | 2150 | onlyjump_p. |
3a941ad5 | 2151 | |
d670e794 | 2152 | Note that unlike condjump_p it returns false for unconditional jumps. */ |
2153 | ||
3a941ad5 | 2154 | int |
2155 | any_condjump_p (insn) | |
2156 | rtx insn; | |
2157 | { | |
2158 | rtx x = pc_set (insn); | |
d670e794 | 2159 | enum rtx_code a, b; |
2160 | ||
3a941ad5 | 2161 | if (!x) |
2162 | return 0; | |
d670e794 | 2163 | if (GET_CODE (SET_SRC (x)) != IF_THEN_ELSE) |
2164 | return 0; | |
3a941ad5 | 2165 | |
d670e794 | 2166 | a = GET_CODE (XEXP (SET_SRC (x), 1)); |
2167 | b = GET_CODE (XEXP (SET_SRC (x), 2)); | |
3a941ad5 | 2168 | |
d670e794 | 2169 | return ((b == PC && (a == LABEL_REF || a == RETURN)) |
7113a566 | 2170 | || (a == PC && (b == LABEL_REF || b == RETURN))); |
3a941ad5 | 2171 | } |
2172 | ||
8f7b24f3 | 2173 | /* Return the label of a conditional jump. */ |
2174 | ||
2175 | rtx | |
2176 | condjump_label (insn) | |
2177 | rtx insn; | |
2178 | { | |
d670e794 | 2179 | rtx x = pc_set (insn); |
8f7b24f3 | 2180 | |
d670e794 | 2181 | if (!x) |
8f7b24f3 | 2182 | return NULL_RTX; |
2183 | x = SET_SRC (x); | |
2184 | if (GET_CODE (x) == LABEL_REF) | |
2185 | return x; | |
2186 | if (GET_CODE (x) != IF_THEN_ELSE) | |
2187 | return NULL_RTX; | |
2188 | if (XEXP (x, 2) == pc_rtx && GET_CODE (XEXP (x, 1)) == LABEL_REF) | |
2189 | return XEXP (x, 1); | |
2190 | if (XEXP (x, 1) == pc_rtx && GET_CODE (XEXP (x, 2)) == LABEL_REF) | |
2191 | return XEXP (x, 2); | |
2192 | return NULL_RTX; | |
2193 | } | |
2194 | ||
71caadc0 | 2195 | /* Return true if INSN is a (possibly conditional) return insn. */ |
2196 | ||
2197 | static int | |
2198 | returnjump_p_1 (loc, data) | |
2199 | rtx *loc; | |
2200 | void *data ATTRIBUTE_UNUSED; | |
2201 | { | |
2202 | rtx x = *loc; | |
8386a92a | 2203 | return x && GET_CODE (x) == RETURN; |
71caadc0 | 2204 | } |
2205 | ||
2206 | int | |
2207 | returnjump_p (insn) | |
2208 | rtx insn; | |
2209 | { | |
cbd914e1 | 2210 | if (GET_CODE (insn) != JUMP_INSN) |
2211 | return 0; | |
71caadc0 | 2212 | return for_each_rtx (&PATTERN (insn), returnjump_p_1, NULL); |
2213 | } | |
2214 | ||
459e9193 | 2215 | /* Return true if INSN is a jump that only transfers control and |
2216 | nothing more. */ | |
2217 | ||
2218 | int | |
2219 | onlyjump_p (insn) | |
2220 | rtx insn; | |
2221 | { | |
2222 | rtx set; | |
2223 | ||
2224 | if (GET_CODE (insn) != JUMP_INSN) | |
2225 | return 0; | |
2226 | ||
2227 | set = single_set (insn); | |
2228 | if (set == NULL) | |
2229 | return 0; | |
2230 | if (GET_CODE (SET_DEST (set)) != PC) | |
2231 | return 0; | |
2232 | if (side_effects_p (SET_SRC (set))) | |
2233 | return 0; | |
2234 | ||
2235 | return 1; | |
2236 | } | |
2237 | ||
9bf8c346 | 2238 | #ifdef HAVE_cc0 |
2239 | ||
5924de0b | 2240 | /* Return 1 if X is an RTX that does nothing but set the condition codes |
2241 | and CLOBBER or USE registers. | |
2242 | Return -1 if X does explicitly set the condition codes, | |
2243 | but also does other things. */ | |
2244 | ||
2245 | int | |
2246 | sets_cc0_p (x) | |
274c11d8 | 2247 | rtx x ATTRIBUTE_UNUSED; |
5924de0b | 2248 | { |
5924de0b | 2249 | if (GET_CODE (x) == SET && SET_DEST (x) == cc0_rtx) |
2250 | return 1; | |
2251 | if (GET_CODE (x) == PARALLEL) | |
2252 | { | |
2253 | int i; | |
2254 | int sets_cc0 = 0; | |
2255 | int other_things = 0; | |
2256 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
2257 | { | |
2258 | if (GET_CODE (XVECEXP (x, 0, i)) == SET | |
2259 | && SET_DEST (XVECEXP (x, 0, i)) == cc0_rtx) | |
2260 | sets_cc0 = 1; | |
2261 | else if (GET_CODE (XVECEXP (x, 0, i)) == SET) | |
2262 | other_things = 1; | |
2263 | } | |
2264 | return ! sets_cc0 ? 0 : other_things ? -1 : 1; | |
2265 | } | |
2266 | return 0; | |
5924de0b | 2267 | } |
9bf8c346 | 2268 | #endif |
5924de0b | 2269 | \f |
2270 | /* Follow any unconditional jump at LABEL; | |
2271 | return the ultimate label reached by any such chain of jumps. | |
2272 | If LABEL is not followed by a jump, return LABEL. | |
35e0b416 | 2273 | If the chain loops or we can't find end, return LABEL, |
2274 | since that tells caller to avoid changing the insn. | |
5924de0b | 2275 | |
2276 | If RELOAD_COMPLETED is 0, we do not chain across a NOTE_INSN_LOOP_BEG or | |
2277 | a USE or CLOBBER. */ | |
2278 | ||
2279 | rtx | |
2280 | follow_jumps (label) | |
2281 | rtx label; | |
2282 | { | |
2283 | register rtx insn; | |
2284 | register rtx next; | |
2285 | register rtx value = label; | |
2286 | register int depth; | |
2287 | ||
2288 | for (depth = 0; | |
2289 | (depth < 10 | |
2290 | && (insn = next_active_insn (value)) != 0 | |
2291 | && GET_CODE (insn) == JUMP_INSN | |
ba08b7e7 | 2292 | && ((JUMP_LABEL (insn) != 0 && any_uncondjump_p (insn) |
2293 | && onlyjump_p (insn)) | |
f93ed41b | 2294 | || GET_CODE (PATTERN (insn)) == RETURN) |
5924de0b | 2295 | && (next = NEXT_INSN (insn)) |
2296 | && GET_CODE (next) == BARRIER); | |
2297 | depth++) | |
2298 | { | |
2299 | /* Don't chain through the insn that jumps into a loop | |
2300 | from outside the loop, | |
2301 | since that would create multiple loop entry jumps | |
2302 | and prevent loop optimization. */ | |
2303 | rtx tem; | |
2304 | if (!reload_completed) | |
2305 | for (tem = value; tem != insn; tem = NEXT_INSN (tem)) | |
2306 | if (GET_CODE (tem) == NOTE | |
55b8f81a | 2307 | && (NOTE_LINE_NUMBER (tem) == NOTE_INSN_LOOP_BEG |
2308 | /* ??? Optional. Disables some optimizations, but makes | |
2309 | gcov output more accurate with -O. */ | |
2310 | || (flag_test_coverage && NOTE_LINE_NUMBER (tem) > 0))) | |
5924de0b | 2311 | return value; |
2312 | ||
2313 | /* If we have found a cycle, make the insn jump to itself. */ | |
2314 | if (JUMP_LABEL (insn) == label) | |
35e0b416 | 2315 | return label; |
cf03b15b | 2316 | |
2317 | tem = next_active_insn (JUMP_LABEL (insn)); | |
2318 | if (tem && (GET_CODE (PATTERN (tem)) == ADDR_VEC | |
2319 | || GET_CODE (PATTERN (tem)) == ADDR_DIFF_VEC)) | |
2320 | break; | |
2321 | ||
5924de0b | 2322 | value = JUMP_LABEL (insn); |
2323 | } | |
35e0b416 | 2324 | if (depth == 10) |
2325 | return label; | |
5924de0b | 2326 | return value; |
2327 | } | |
2328 | ||
2329 | /* Assuming that field IDX of X is a vector of label_refs, | |
2330 | replace each of them by the ultimate label reached by it. | |
2331 | Return nonzero if a change is made. | |
2332 | If IGNORE_LOOPS is 0, we do not chain across a NOTE_INSN_LOOP_BEG. */ | |
2333 | ||
2334 | static int | |
2335 | tension_vector_labels (x, idx) | |
2336 | register rtx x; | |
2337 | register int idx; | |
2338 | { | |
2339 | int changed = 0; | |
2340 | register int i; | |
2341 | for (i = XVECLEN (x, idx) - 1; i >= 0; i--) | |
2342 | { | |
2343 | register rtx olabel = XEXP (XVECEXP (x, idx, i), 0); | |
2344 | register rtx nlabel = follow_jumps (olabel); | |
2345 | if (nlabel && nlabel != olabel) | |
2346 | { | |
2347 | XEXP (XVECEXP (x, idx, i), 0) = nlabel; | |
2348 | ++LABEL_NUSES (nlabel); | |
2349 | if (--LABEL_NUSES (olabel) == 0) | |
2350 | delete_insn (olabel); | |
2351 | changed = 1; | |
2352 | } | |
2353 | } | |
2354 | return changed; | |
2355 | } | |
2356 | \f | |
2357 | /* Find all CODE_LABELs referred to in X, and increment their use counts. | |
2358 | If INSN is a JUMP_INSN and there is at least one CODE_LABEL referenced | |
2359 | in INSN, then store one of them in JUMP_LABEL (INSN). | |
2360 | If INSN is an INSN or a CALL_INSN and there is at least one CODE_LABEL | |
2361 | referenced in INSN, add a REG_LABEL note containing that label to INSN. | |
2362 | Also, when there are consecutive labels, canonicalize on the last of them. | |
2363 | ||
2364 | Note that two labels separated by a loop-beginning note | |
2365 | must be kept distinct if we have not yet done loop-optimization, | |
2366 | because the gap between them is where loop-optimize | |
2367 | will want to move invariant code to. CROSS_JUMP tells us | |
2368 | that loop-optimization is done with. | |
2369 | ||
2370 | Once reload has completed (CROSS_JUMP non-zero), we need not consider | |
2371 | two labels distinct if they are separated by only USE or CLOBBER insns. */ | |
2372 | ||
2373 | static void | |
190099a6 | 2374 | mark_jump_label (x, insn, cross_jump, in_mem) |
5924de0b | 2375 | register rtx x; |
2376 | rtx insn; | |
2377 | int cross_jump; | |
190099a6 | 2378 | int in_mem; |
5924de0b | 2379 | { |
2380 | register RTX_CODE code = GET_CODE (x); | |
2381 | register int i; | |
d2ca078f | 2382 | register const char *fmt; |
5924de0b | 2383 | |
2384 | switch (code) | |
2385 | { | |
2386 | case PC: | |
2387 | case CC0: | |
2388 | case REG: | |
2389 | case SUBREG: | |
2390 | case CONST_INT: | |
5924de0b | 2391 | case CONST_DOUBLE: |
2392 | case CLOBBER: | |
2393 | case CALL: | |
2394 | return; | |
2395 | ||
d8e0d332 | 2396 | case MEM: |
190099a6 | 2397 | in_mem = 1; |
2398 | break; | |
2399 | ||
2400 | case SYMBOL_REF: | |
2401 | if (!in_mem) | |
7113a566 | 2402 | return; |
190099a6 | 2403 | |
d8e0d332 | 2404 | /* If this is a constant-pool reference, see if it is a label. */ |
190099a6 | 2405 | if (CONSTANT_POOL_ADDRESS_P (x)) |
7113a566 | 2406 | mark_jump_label (get_pool_constant (x), insn, cross_jump, in_mem); |
d8e0d332 | 2407 | break; |
2408 | ||
5924de0b | 2409 | case LABEL_REF: |
2410 | { | |
b4d3bcce | 2411 | rtx label = XEXP (x, 0); |
2412 | rtx olabel = label; | |
2413 | rtx note; | |
2414 | rtx next; | |
2415 | ||
74b0991d | 2416 | /* Ignore remaining references to unreachable labels that |
2417 | have been deleted. */ | |
7113a566 | 2418 | if (GET_CODE (label) == NOTE |
74b0991d | 2419 | && NOTE_LINE_NUMBER (label) == NOTE_INSN_DELETED_LABEL) |
2420 | break; | |
2421 | ||
5924de0b | 2422 | if (GET_CODE (label) != CODE_LABEL) |
2423 | abort (); | |
b4d3bcce | 2424 | |
f08cae9d | 2425 | /* Ignore references to labels of containing functions. */ |
2426 | if (LABEL_REF_NONLOCAL_P (x)) | |
2427 | break; | |
b4d3bcce | 2428 | |
5924de0b | 2429 | /* If there are other labels following this one, |
2430 | replace it with the last of the consecutive labels. */ | |
2431 | for (next = NEXT_INSN (label); next; next = NEXT_INSN (next)) | |
2432 | { | |
2433 | if (GET_CODE (next) == CODE_LABEL) | |
2434 | label = next; | |
2435 | else if (cross_jump && GET_CODE (next) == INSN | |
2436 | && (GET_CODE (PATTERN (next)) == USE | |
2437 | || GET_CODE (PATTERN (next)) == CLOBBER)) | |
2438 | continue; | |
2439 | else if (GET_CODE (next) != NOTE) | |
2440 | break; | |
2441 | else if (! cross_jump | |
2442 | && (NOTE_LINE_NUMBER (next) == NOTE_INSN_LOOP_BEG | |
55b8f81a | 2443 | || NOTE_LINE_NUMBER (next) == NOTE_INSN_FUNCTION_END |
2444 | /* ??? Optional. Disables some optimizations, but | |
2445 | makes gcov output more accurate with -O. */ | |
7113a566 | 2446 | || (flag_test_coverage |
2447 | && NOTE_LINE_NUMBER (next) > 0))) | |
5924de0b | 2448 | break; |
2449 | } | |
b4d3bcce | 2450 | |
5924de0b | 2451 | XEXP (x, 0) = label; |
943e16d8 | 2452 | if (! insn || ! INSN_DELETED_P (insn)) |
2453 | ++LABEL_NUSES (label); | |
b4d3bcce | 2454 | |
5924de0b | 2455 | if (insn) |
2456 | { | |
2457 | if (GET_CODE (insn) == JUMP_INSN) | |
2458 | JUMP_LABEL (insn) = label; | |
b4d3bcce | 2459 | |
2460 | /* If we've changed OLABEL and we had a REG_LABEL note | |
2461 | for it, update it as well. */ | |
2462 | else if (label != olabel | |
2463 | && (note = find_reg_note (insn, REG_LABEL, olabel)) != 0) | |
2464 | XEXP (note, 0) = label; | |
2465 | ||
2466 | /* Otherwise, add a REG_LABEL note for LABEL unless there already | |
2467 | is one. */ | |
d69b16d3 | 2468 | else if (! find_reg_note (insn, REG_LABEL, label)) |
5924de0b | 2469 | { |
295fce46 | 2470 | /* This code used to ignore labels which refered to dispatch |
2471 | tables to avoid flow.c generating worse code. | |
2472 | ||
2473 | However, in the presense of global optimizations like | |
2474 | gcse which call find_basic_blocks without calling | |
2475 | life_analysis, not recording such labels will lead | |
2476 | to compiler aborts because of inconsistencies in the | |
2477 | flow graph. So we go ahead and record the label. | |
2478 | ||
2479 | It may also be the case that the optimization argument | |
2480 | is no longer valid because of the more accurate cfg | |
2481 | we build in find_basic_blocks -- it no longer pessimizes | |
2482 | code when it finds a REG_LABEL note. */ | |
74b0991d | 2483 | REG_NOTES (insn) = gen_rtx_INSN_LIST (REG_LABEL, label, |
295fce46 | 2484 | REG_NOTES (insn)); |
5924de0b | 2485 | } |
2486 | } | |
2487 | return; | |
2488 | } | |
2489 | ||
2490 | /* Do walk the labels in a vector, but not the first operand of an | |
2491 | ADDR_DIFF_VEC. Don't set the JUMP_LABEL of a vector. */ | |
2492 | case ADDR_VEC: | |
2493 | case ADDR_DIFF_VEC: | |
943e16d8 | 2494 | if (! INSN_DELETED_P (insn)) |
2495 | { | |
2496 | int eltnum = code == ADDR_DIFF_VEC ? 1 : 0; | |
5924de0b | 2497 | |
943e16d8 | 2498 | for (i = 0; i < XVECLEN (x, eltnum); i++) |
7113a566 | 2499 | mark_jump_label (XVECEXP (x, eltnum, i), NULL_RTX, |
2500 | cross_jump, in_mem); | |
943e16d8 | 2501 | } |
0dbd1c74 | 2502 | return; |
7113a566 | 2503 | |
0dbd1c74 | 2504 | default: |
2505 | break; | |
5924de0b | 2506 | } |
2507 | ||
2508 | fmt = GET_RTX_FORMAT (code); | |
2509 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
2510 | { | |
2511 | if (fmt[i] == 'e') | |
190099a6 | 2512 | mark_jump_label (XEXP (x, i), insn, cross_jump, in_mem); |
5924de0b | 2513 | else if (fmt[i] == 'E') |
2514 | { | |
2515 | register int j; | |
2516 | for (j = 0; j < XVECLEN (x, i); j++) | |
190099a6 | 2517 | mark_jump_label (XVECEXP (x, i, j), insn, cross_jump, in_mem); |
5924de0b | 2518 | } |
2519 | } | |
2520 | } | |
2521 | ||
2522 | /* If all INSN does is set the pc, delete it, | |
2523 | and delete the insn that set the condition codes for it | |
2524 | if that's what the previous thing was. */ | |
2525 | ||
2526 | void | |
2527 | delete_jump (insn) | |
2528 | rtx insn; | |
2529 | { | |
f4ef05ab | 2530 | register rtx set = single_set (insn); |
2531 | ||
2532 | if (set && GET_CODE (SET_DEST (set)) == PC) | |
2533 | delete_computation (insn); | |
2534 | } | |
2535 | ||
155b05dc | 2536 | /* Verify INSN is a BARRIER and delete it. */ |
2537 | ||
2538 | void | |
2539 | delete_barrier (insn) | |
2540 | rtx insn; | |
2541 | { | |
2542 | if (GET_CODE (insn) != BARRIER) | |
2543 | abort (); | |
2544 | ||
2545 | delete_insn (insn); | |
2546 | } | |
2547 | ||
ab1241f2 | 2548 | /* Recursively delete prior insns that compute the value (used only by INSN |
2549 | which the caller is deleting) stored in the register mentioned by NOTE | |
2550 | which is a REG_DEAD note associated with INSN. */ | |
2551 | ||
2552 | static void | |
2553 | delete_prior_computation (note, insn) | |
2554 | rtx note; | |
2555 | rtx insn; | |
2556 | { | |
2557 | rtx our_prev; | |
2558 | rtx reg = XEXP (note, 0); | |
2559 | ||
2560 | for (our_prev = prev_nonnote_insn (insn); | |
272a2170 | 2561 | our_prev && (GET_CODE (our_prev) == INSN |
2562 | || GET_CODE (our_prev) == CALL_INSN); | |
ab1241f2 | 2563 | our_prev = prev_nonnote_insn (our_prev)) |
2564 | { | |
2565 | rtx pat = PATTERN (our_prev); | |
2566 | ||
272a2170 | 2567 | /* If we reach a CALL which is not calling a const function |
2568 | or the callee pops the arguments, then give up. */ | |
2569 | if (GET_CODE (our_prev) == CALL_INSN | |
2570 | && (! CONST_CALL_P (our_prev) | |
2571 | || GET_CODE (pat) != SET || GET_CODE (SET_SRC (pat)) != CALL)) | |
2572 | break; | |
2573 | ||
ab1241f2 | 2574 | /* If we reach a SEQUENCE, it is too complex to try to |
2575 | do anything with it, so give up. */ | |
2576 | if (GET_CODE (pat) == SEQUENCE) | |
2577 | break; | |
2578 | ||
2579 | if (GET_CODE (pat) == USE | |
2580 | && GET_CODE (XEXP (pat, 0)) == INSN) | |
2581 | /* reorg creates USEs that look like this. We leave them | |
2582 | alone because reorg needs them for its own purposes. */ | |
2583 | break; | |
2584 | ||
2585 | if (reg_set_p (reg, pat)) | |
2586 | { | |
272a2170 | 2587 | if (side_effects_p (pat) && GET_CODE (our_prev) != CALL_INSN) |
ab1241f2 | 2588 | break; |
2589 | ||
2590 | if (GET_CODE (pat) == PARALLEL) | |
2591 | { | |
2592 | /* If we find a SET of something else, we can't | |
2593 | delete the insn. */ | |
2594 | ||
2595 | int i; | |
2596 | ||
2597 | for (i = 0; i < XVECLEN (pat, 0); i++) | |
2598 | { | |
2599 | rtx part = XVECEXP (pat, 0, i); | |
2600 | ||
2601 | if (GET_CODE (part) == SET | |
2602 | && SET_DEST (part) != reg) | |
2603 | break; | |
2604 | } | |
2605 | ||
2606 | if (i == XVECLEN (pat, 0)) | |
2607 | delete_computation (our_prev); | |
2608 | } | |
2609 | else if (GET_CODE (pat) == SET | |
2610 | && GET_CODE (SET_DEST (pat)) == REG) | |
2611 | { | |
2612 | int dest_regno = REGNO (SET_DEST (pat)); | |
2613 | int dest_endregno | |
7113a566 | 2614 | = (dest_regno |
2615 | + (dest_regno < FIRST_PSEUDO_REGISTER | |
ab1241f2 | 2616 | ? HARD_REGNO_NREGS (dest_regno, |
7113a566 | 2617 | GET_MODE (SET_DEST (pat))) : 1)); |
ab1241f2 | 2618 | int regno = REGNO (reg); |
7113a566 | 2619 | int endregno |
2620 | = (regno | |
2621 | + (regno < FIRST_PSEUDO_REGISTER | |
2622 | ? HARD_REGNO_NREGS (regno, GET_MODE (reg)) : 1)); | |
ab1241f2 | 2623 | |
2624 | if (dest_regno >= regno | |
2625 | && dest_endregno <= endregno) | |
2626 | delete_computation (our_prev); | |
2627 | ||
2628 | /* We may have a multi-word hard register and some, but not | |
2629 | all, of the words of the register are needed in subsequent | |
2630 | insns. Write REG_UNUSED notes for those parts that were not | |
2631 | needed. */ | |
2632 | else if (dest_regno <= regno | |
272a2170 | 2633 | && dest_endregno >= endregno) |
ab1241f2 | 2634 | { |
2635 | int i; | |
2636 | ||
2637 | REG_NOTES (our_prev) | |
7113a566 | 2638 | = gen_rtx_EXPR_LIST (REG_UNUSED, reg, |
2639 | REG_NOTES (our_prev)); | |
ab1241f2 | 2640 | |
2641 | for (i = dest_regno; i < dest_endregno; i++) | |
2642 | if (! find_regno_note (our_prev, REG_UNUSED, i)) | |
2643 | break; | |
2644 | ||
2645 | if (i == dest_endregno) | |
2646 | delete_computation (our_prev); | |
2647 | } | |
2648 | } | |
2649 | ||
2650 | break; | |
2651 | } | |
2652 | ||
2653 | /* If PAT references the register that dies here, it is an | |
2654 | additional use. Hence any prior SET isn't dead. However, this | |
2655 | insn becomes the new place for the REG_DEAD note. */ | |
2656 | if (reg_overlap_mentioned_p (reg, pat)) | |
2657 | { | |
2658 | XEXP (note, 1) = REG_NOTES (our_prev); | |
2659 | REG_NOTES (our_prev) = note; | |
2660 | break; | |
2661 | } | |
2662 | } | |
2663 | } | |
2664 | ||
f4ef05ab | 2665 | /* Delete INSN and recursively delete insns that compute values used only |
2666 | by INSN. This uses the REG_DEAD notes computed during flow analysis. | |
2667 | If we are running before flow.c, we need do nothing since flow.c will | |
2668 | delete dead code. We also can't know if the registers being used are | |
2669 | dead or not at this point. | |
2670 | ||
2671 | Otherwise, look at all our REG_DEAD notes. If a previous insn does | |
2672 | nothing other than set a register that dies in this insn, we can delete | |
2673 | that insn as well. | |
2674 | ||
2675 | On machines with CC0, if CC0 is used in this insn, we may be able to | |
2676 | delete the insn that set it. */ | |
2677 | ||
fb374064 | 2678 | static void |
f4ef05ab | 2679 | delete_computation (insn) |
2680 | rtx insn; | |
2681 | { | |
2682 | rtx note, next; | |
5924de0b | 2683 | |
5924de0b | 2684 | #ifdef HAVE_cc0 |
41d75671 | 2685 | if (reg_referenced_p (cc0_rtx, PATTERN (insn))) |
f4ef05ab | 2686 | { |
5b39732e | 2687 | rtx prev = prev_nonnote_insn (insn); |
5924de0b | 2688 | /* We assume that at this stage |
2689 | CC's are always set explicitly | |
2690 | and always immediately before the jump that | |
2691 | will use them. So if the previous insn | |
2692 | exists to set the CC's, delete it | |
2693 | (unless it performs auto-increments, etc.). */ | |
2694 | if (prev && GET_CODE (prev) == INSN | |
2695 | && sets_cc0_p (PATTERN (prev))) | |
2696 | { | |
2697 | if (sets_cc0_p (PATTERN (prev)) > 0 | |
ab1241f2 | 2698 | && ! side_effects_p (PATTERN (prev))) |
f4ef05ab | 2699 | delete_computation (prev); |
5924de0b | 2700 | else |
2701 | /* Otherwise, show that cc0 won't be used. */ | |
941522d6 | 2702 | REG_NOTES (prev) = gen_rtx_EXPR_LIST (REG_UNUSED, |
2703 | cc0_rtx, REG_NOTES (prev)); | |
5924de0b | 2704 | } |
5b39732e | 2705 | } |
f4ef05ab | 2706 | #endif |
5924de0b | 2707 | |
5b39732e | 2708 | for (note = REG_NOTES (insn); note; note = next) |
2709 | { | |
5b39732e | 2710 | next = XEXP (note, 1); |
5924de0b | 2711 | |
5b39732e | 2712 | if (REG_NOTE_KIND (note) != REG_DEAD |
2713 | /* Verify that the REG_NOTE is legitimate. */ | |
2714 | || GET_CODE (XEXP (note, 0)) != REG) | |
2715 | continue; | |
5924de0b | 2716 | |
ab1241f2 | 2717 | delete_prior_computation (note, insn); |
5924de0b | 2718 | } |
f4ef05ab | 2719 | |
5b39732e | 2720 | delete_insn (insn); |
5924de0b | 2721 | } |
2722 | \f | |
2723 | /* Delete insn INSN from the chain of insns and update label ref counts. | |
2724 | May delete some following insns as a consequence; may even delete | |
2725 | a label elsewhere and insns that follow it. | |
2726 | ||
2727 | Returns the first insn after INSN that was not deleted. */ | |
2728 | ||
2729 | rtx | |
2730 | delete_insn (insn) | |
2731 | register rtx insn; | |
2732 | { | |
2733 | register rtx next = NEXT_INSN (insn); | |
2734 | register rtx prev = PREV_INSN (insn); | |
9cdc08c6 | 2735 | register int was_code_label = (GET_CODE (insn) == CODE_LABEL); |
2736 | register int dont_really_delete = 0; | |
d3df77e9 | 2737 | rtx note; |
5924de0b | 2738 | |
2739 | while (next && INSN_DELETED_P (next)) | |
2740 | next = NEXT_INSN (next); | |
2741 | ||
2742 | /* This insn is already deleted => return first following nondeleted. */ | |
2743 | if (INSN_DELETED_P (insn)) | |
2744 | return next; | |
2745 | ||
13d60e7c | 2746 | if (was_code_label) |
2747 | remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels); | |
2748 | ||
a311e300 | 2749 | /* Don't delete user-declared labels. When optimizing, convert them |
2750 | to special NOTEs instead. When not optimizing, leave them alone. */ | |
2751 | if (was_code_label && LABEL_NAME (insn) != 0) | |
9cdc08c6 | 2752 | { |
a311e300 | 2753 | if (! optimize) |
2754 | dont_really_delete = 1; | |
2755 | else if (! dont_really_delete) | |
2756 | { | |
74b0991d | 2757 | const char *name = LABEL_NAME (insn); |
a311e300 | 2758 | PUT_CODE (insn, NOTE); |
2759 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED_LABEL; | |
74b0991d | 2760 | NOTE_SOURCE_FILE (insn) = name; |
a311e300 | 2761 | dont_really_delete = 1; |
2762 | } | |
9cdc08c6 | 2763 | } |
2764 | else | |
2765 | /* Mark this insn as deleted. */ | |
2766 | INSN_DELETED_P (insn) = 1; | |
5924de0b | 2767 | |
2768 | /* If this is an unconditional jump, delete it from the jump chain. */ | |
2769 | if (simplejump_p (insn)) | |
2770 | delete_from_jump_chain (insn); | |
2771 | ||
2772 | /* If instruction is followed by a barrier, | |
2773 | delete the barrier too. */ | |
2774 | ||
2775 | if (next != 0 && GET_CODE (next) == BARRIER) | |
2776 | { | |
2777 | INSN_DELETED_P (next) = 1; | |
2778 | next = NEXT_INSN (next); | |
2779 | } | |
2780 | ||
2781 | /* Patch out INSN (and the barrier if any) */ | |
2782 | ||
dd2acd83 | 2783 | if (! dont_really_delete) |
5924de0b | 2784 | { |
2785 | if (prev) | |
2786 | { | |
2787 | NEXT_INSN (prev) = next; | |
2788 | if (GET_CODE (prev) == INSN && GET_CODE (PATTERN (prev)) == SEQUENCE) | |
2789 | NEXT_INSN (XVECEXP (PATTERN (prev), 0, | |
2790 | XVECLEN (PATTERN (prev), 0) - 1)) = next; | |
2791 | } | |
2792 | ||
2793 | if (next) | |
2794 | { | |
2795 | PREV_INSN (next) = prev; | |
2796 | if (GET_CODE (next) == INSN && GET_CODE (PATTERN (next)) == SEQUENCE) | |
2797 | PREV_INSN (XVECEXP (PATTERN (next), 0, 0)) = prev; | |
2798 | } | |
2799 | ||
2800 | if (prev && NEXT_INSN (prev) == 0) | |
2801 | set_last_insn (prev); | |
2802 | } | |
2803 | ||
2804 | /* If deleting a jump, decrement the count of the label, | |
2805 | and delete the label if it is now unused. */ | |
2806 | ||
2807 | if (GET_CODE (insn) == JUMP_INSN && JUMP_LABEL (insn)) | |
1793cd6b | 2808 | { |
2809 | rtx lab = JUMP_LABEL (insn), lab_next; | |
2810 | ||
2811 | if (--LABEL_NUSES (lab) == 0) | |
2812 | { | |
2813 | /* This can delete NEXT or PREV, | |
2814 | either directly if NEXT is JUMP_LABEL (INSN), | |
2815 | or indirectly through more levels of jumps. */ | |
2816 | delete_insn (lab); | |
2817 | ||
2818 | /* I feel a little doubtful about this loop, | |
2819 | but I see no clean and sure alternative way | |
2820 | to find the first insn after INSN that is not now deleted. | |
2821 | I hope this works. */ | |
2822 | while (next && INSN_DELETED_P (next)) | |
2823 | next = NEXT_INSN (next); | |
2824 | return next; | |
2825 | } | |
2826 | else if ((lab_next = next_nonnote_insn (lab)) != NULL | |
2827 | && GET_CODE (lab_next) == JUMP_INSN | |
2828 | && (GET_CODE (PATTERN (lab_next)) == ADDR_VEC | |
2829 | || GET_CODE (PATTERN (lab_next)) == ADDR_DIFF_VEC)) | |
2830 | { | |
2831 | /* If we're deleting the tablejump, delete the dispatch table. | |
2832 | We may not be able to kill the label immediately preceeding | |
2833 | just yet, as it might be referenced in code leading up to | |
2834 | the tablejump. */ | |
2835 | delete_insn (lab_next); | |
2836 | } | |
2837 | } | |
5924de0b | 2838 | |
9c9e0c01 | 2839 | /* Likewise if we're deleting a dispatch table. */ |
2840 | ||
2841 | if (GET_CODE (insn) == JUMP_INSN | |
2842 | && (GET_CODE (PATTERN (insn)) == ADDR_VEC | |
2843 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)) | |
2844 | { | |
2845 | rtx pat = PATTERN (insn); | |
2846 | int i, diff_vec_p = GET_CODE (pat) == ADDR_DIFF_VEC; | |
2847 | int len = XVECLEN (pat, diff_vec_p); | |
2848 | ||
2849 | for (i = 0; i < len; i++) | |
2850 | if (--LABEL_NUSES (XEXP (XVECEXP (pat, diff_vec_p, i), 0)) == 0) | |
2851 | delete_insn (XEXP (XVECEXP (pat, diff_vec_p, i), 0)); | |
2852 | while (next && INSN_DELETED_P (next)) | |
2853 | next = NEXT_INSN (next); | |
2854 | return next; | |
2855 | } | |
2856 | ||
d3df77e9 | 2857 | /* Likewise for an ordinary INSN / CALL_INSN with a REG_LABEL note. */ |
2858 | if (GET_CODE (insn) == INSN || GET_CODE (insn) == CALL_INSN) | |
2859 | for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) | |
2860 | if (REG_NOTE_KIND (note) == REG_LABEL) | |
2861 | if (--LABEL_NUSES (XEXP (note, 0)) == 0) | |
2862 | delete_insn (XEXP (note, 0)); | |
2863 | ||
5924de0b | 2864 | while (prev && (INSN_DELETED_P (prev) || GET_CODE (prev) == NOTE)) |
2865 | prev = PREV_INSN (prev); | |
2866 | ||
2867 | /* If INSN was a label and a dispatch table follows it, | |
2868 | delete the dispatch table. The tablejump must have gone already. | |
2869 | It isn't useful to fall through into a table. */ | |
2870 | ||
9cdc08c6 | 2871 | if (was_code_label |
5924de0b | 2872 | && NEXT_INSN (insn) != 0 |
2873 | && GET_CODE (NEXT_INSN (insn)) == JUMP_INSN | |
2874 | && (GET_CODE (PATTERN (NEXT_INSN (insn))) == ADDR_VEC | |
2875 | || GET_CODE (PATTERN (NEXT_INSN (insn))) == ADDR_DIFF_VEC)) | |
2876 | next = delete_insn (NEXT_INSN (insn)); | |
2877 | ||
2878 | /* If INSN was a label, delete insns following it if now unreachable. */ | |
2879 | ||
9cdc08c6 | 2880 | if (was_code_label && prev && GET_CODE (prev) == BARRIER) |
5924de0b | 2881 | { |
2882 | register RTX_CODE code; | |
2883 | while (next != 0 | |
fb374064 | 2884 | && (GET_RTX_CLASS (code = GET_CODE (next)) == 'i' |
64f0b11f | 2885 | || code == NOTE || code == BARRIER |
59bee35e | 2886 | || (code == CODE_LABEL && INSN_DELETED_P (next)))) |
5924de0b | 2887 | { |
2888 | if (code == NOTE | |
2889 | && NOTE_LINE_NUMBER (next) != NOTE_INSN_FUNCTION_END) | |
2890 | next = NEXT_INSN (next); | |
59bee35e | 2891 | /* Keep going past other deleted labels to delete what follows. */ |
2892 | else if (code == CODE_LABEL && INSN_DELETED_P (next)) | |
2893 | next = NEXT_INSN (next); | |
5924de0b | 2894 | else |
2895 | /* Note: if this deletes a jump, it can cause more | |
2896 | deletion of unreachable code, after a different label. | |
2897 | As long as the value from this recursive call is correct, | |
2898 | this invocation functions correctly. */ | |
2899 | next = delete_insn (next); | |
2900 | } | |
2901 | } | |
2902 | ||
2903 | return next; | |
2904 | } | |
2905 | ||
2906 | /* Advance from INSN till reaching something not deleted | |
2907 | then return that. May return INSN itself. */ | |
2908 | ||
2909 | rtx | |
2910 | next_nondeleted_insn (insn) | |
2911 | rtx insn; | |
2912 | { | |
2913 | while (INSN_DELETED_P (insn)) | |
2914 | insn = NEXT_INSN (insn); | |
2915 | return insn; | |
2916 | } | |
2917 | \f | |
2918 | /* Delete a range of insns from FROM to TO, inclusive. | |
2919 | This is for the sake of peephole optimization, so assume | |
2920 | that whatever these insns do will still be done by a new | |
2921 | peephole insn that will replace them. */ | |
2922 | ||
2923 | void | |
2924 | delete_for_peephole (from, to) | |
2925 | register rtx from, to; | |
2926 | { | |
2927 | register rtx insn = from; | |
2928 | ||
2929 | while (1) | |
2930 | { | |
2931 | register rtx next = NEXT_INSN (insn); | |
2932 | register rtx prev = PREV_INSN (insn); | |
2933 | ||
2934 | if (GET_CODE (insn) != NOTE) | |
2935 | { | |
2936 | INSN_DELETED_P (insn) = 1; | |
2937 | ||
2938 | /* Patch this insn out of the chain. */ | |
2939 | /* We don't do this all at once, because we | |
2940 | must preserve all NOTEs. */ | |
2941 | if (prev) | |
2942 | NEXT_INSN (prev) = next; | |
2943 | ||
2944 | if (next) | |
2945 | PREV_INSN (next) = prev; | |
2946 | } | |
2947 | ||
2948 | if (insn == to) | |
2949 | break; | |
2950 | insn = next; | |
2951 | } | |
2952 | ||
2953 | /* Note that if TO is an unconditional jump | |
2954 | we *do not* delete the BARRIER that follows, | |
2955 | since the peephole that replaces this sequence | |
2956 | is also an unconditional jump in that case. */ | |
2957 | } | |
2958 | \f | |
71a3455a | 2959 | /* We have determined that INSN is never reached, and are about to |
2960 | delete it. Print a warning if the user asked for one. | |
2961 | ||
2962 | To try to make this warning more useful, this should only be called | |
2963 | once per basic block not reached, and it only warns when the basic | |
2964 | block contains more than one line from the current function, and | |
2965 | contains at least one operation. CSE and inlining can duplicate insns, | |
2966 | so it's possible to get spurious warnings from this. */ | |
2967 | ||
2968 | void | |
2969 | never_reached_warning (avoided_insn) | |
2970 | rtx avoided_insn; | |
2971 | { | |
2972 | rtx insn; | |
2973 | rtx a_line_note = NULL; | |
2974 | int two_avoided_lines = 0; | |
2975 | int contains_insn = 0; | |
7113a566 | 2976 | |
71a3455a | 2977 | if (! warn_notreached) |
2978 | return; | |
2979 | ||
2980 | /* Scan forwards, looking at LINE_NUMBER notes, until | |
2981 | we hit a LABEL or we run out of insns. */ | |
7113a566 | 2982 | |
71a3455a | 2983 | for (insn = avoided_insn; insn != NULL; insn = NEXT_INSN (insn)) |
2984 | { | |
7113a566 | 2985 | if (GET_CODE (insn) == CODE_LABEL) |
2986 | break; | |
2987 | else if (GET_CODE (insn) == NOTE /* A line number note? */ | |
2988 | && NOTE_LINE_NUMBER (insn) >= 0) | |
71a3455a | 2989 | { |
2990 | if (a_line_note == NULL) | |
2991 | a_line_note = insn; | |
2992 | else | |
2993 | two_avoided_lines |= (NOTE_LINE_NUMBER (a_line_note) | |
2994 | != NOTE_LINE_NUMBER (insn)); | |
2995 | } | |
9204e736 | 2996 | else if (INSN_P (insn)) |
7113a566 | 2997 | contains_insn = 1; |
71a3455a | 2998 | } |
2999 | if (two_avoided_lines && contains_insn) | |
3000 | warning_with_file_and_line (NOTE_SOURCE_FILE (a_line_note), | |
3001 | NOTE_LINE_NUMBER (a_line_note), | |
3002 | "will never be executed"); | |
3003 | } | |
3004 | \f | |
a8b5d014 | 3005 | /* Throughout LOC, redirect OLABEL to NLABEL. Treat null OLABEL or |
3006 | NLABEL as a return. Accrue modifications into the change group. */ | |
5924de0b | 3007 | |
a8b5d014 | 3008 | static void |
3009 | redirect_exp_1 (loc, olabel, nlabel, insn) | |
3010 | rtx *loc; | |
3011 | rtx olabel, nlabel; | |
5924de0b | 3012 | rtx insn; |
3013 | { | |
a8b5d014 | 3014 | register rtx x = *loc; |
3015 | register RTX_CODE code = GET_CODE (x); | |
5924de0b | 3016 | register int i; |
d2ca078f | 3017 | register const char *fmt; |
5924de0b | 3018 | |
a8b5d014 | 3019 | if (code == LABEL_REF) |
5924de0b | 3020 | { |
a8b5d014 | 3021 | if (XEXP (x, 0) == olabel) |
3022 | { | |
3023 | rtx n; | |
3024 | if (nlabel) | |
3025 | n = gen_rtx_LABEL_REF (VOIDmode, nlabel); | |
3026 | else | |
7113a566 | 3027 | n = gen_rtx_RETURN (VOIDmode); |
5924de0b | 3028 | |
a8b5d014 | 3029 | validate_change (insn, loc, n, 1); |
3030 | return; | |
3031 | } | |
3032 | } | |
3033 | else if (code == RETURN && olabel == 0) | |
3034 | { | |
3035 | x = gen_rtx_LABEL_REF (VOIDmode, nlabel); | |
3036 | if (loc == &PATTERN (insn)) | |
3037 | x = gen_rtx_SET (VOIDmode, pc_rtx, x); | |
3038 | validate_change (insn, loc, x, 1); | |
3039 | return; | |
3040 | } | |
5924de0b | 3041 | |
a8b5d014 | 3042 | if (code == SET && nlabel == 0 && SET_DEST (x) == pc_rtx |
3043 | && GET_CODE (SET_SRC (x)) == LABEL_REF | |
3044 | && XEXP (SET_SRC (x), 0) == olabel) | |
3045 | { | |
3046 | validate_change (insn, loc, gen_rtx_RETURN (VOIDmode), 1); | |
3047 | return; | |
5924de0b | 3048 | } |
3049 | ||
3050 | fmt = GET_RTX_FORMAT (code); | |
3051 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
3052 | { | |
3053 | if (fmt[i] == 'e') | |
a8b5d014 | 3054 | redirect_exp_1 (&XEXP (x, i), olabel, nlabel, insn); |
1bd8ca86 | 3055 | else if (fmt[i] == 'E') |
5924de0b | 3056 | { |
3057 | register int j; | |
3058 | for (j = 0; j < XVECLEN (x, i); j++) | |
a8b5d014 | 3059 | redirect_exp_1 (&XVECEXP (x, i, j), olabel, nlabel, insn); |
5924de0b | 3060 | } |
3061 | } | |
a8b5d014 | 3062 | } |
5924de0b | 3063 | |
a8b5d014 | 3064 | /* Similar, but apply the change group and report success or failure. */ |
3065 | ||
ba08b7e7 | 3066 | static int |
3067 | redirect_exp (olabel, nlabel, insn) | |
a8b5d014 | 3068 | rtx olabel, nlabel; |
3069 | rtx insn; | |
3070 | { | |
ba08b7e7 | 3071 | rtx *loc; |
3072 | ||
3073 | if (GET_CODE (PATTERN (insn)) == PARALLEL) | |
3074 | loc = &XVECEXP (PATTERN (insn), 0, 0); | |
3075 | else | |
3076 | loc = &PATTERN (insn); | |
3077 | ||
a8b5d014 | 3078 | redirect_exp_1 (loc, olabel, nlabel, insn); |
3079 | if (num_validated_changes () == 0) | |
3080 | return 0; | |
3081 | ||
3082 | return apply_change_group (); | |
5924de0b | 3083 | } |
a8b5d014 | 3084 | |
3085 | /* Make JUMP go to NLABEL instead of where it jumps now. Accrue | |
3086 | the modifications into the change group. Return false if we did | |
3087 | not see how to do that. */ | |
3088 | ||
3089 | int | |
3090 | redirect_jump_1 (jump, nlabel) | |
3091 | rtx jump, nlabel; | |
3092 | { | |
3093 | int ochanges = num_validated_changes (); | |
ba08b7e7 | 3094 | rtx *loc; |
3095 | ||
3096 | if (GET_CODE (PATTERN (jump)) == PARALLEL) | |
3097 | loc = &XVECEXP (PATTERN (jump), 0, 0); | |
3098 | else | |
3099 | loc = &PATTERN (jump); | |
3100 | ||
3101 | redirect_exp_1 (loc, JUMP_LABEL (jump), nlabel, jump); | |
a8b5d014 | 3102 | return num_validated_changes () > ochanges; |
3103 | } | |
3104 | ||
3105 | /* Make JUMP go to NLABEL instead of where it jumps now. If the old | |
3106 | jump target label is unused as a result, it and the code following | |
3107 | it may be deleted. | |
5924de0b | 3108 | |
3109 | If NLABEL is zero, we are to turn the jump into a (possibly conditional) | |
3110 | RETURN insn. | |
3111 | ||
a8b5d014 | 3112 | The return value will be 1 if the change was made, 0 if it wasn't |
3113 | (this can only occur for NLABEL == 0). */ | |
5924de0b | 3114 | |
3115 | int | |
f8cacb57 | 3116 | redirect_jump (jump, nlabel, delete_unused) |
5924de0b | 3117 | rtx jump, nlabel; |
f8cacb57 | 3118 | int delete_unused; |
5924de0b | 3119 | { |
3120 | register rtx olabel = JUMP_LABEL (jump); | |
3121 | ||
3122 | if (nlabel == olabel) | |
3123 | return 1; | |
3124 | ||
ba08b7e7 | 3125 | if (! redirect_exp (olabel, nlabel, jump)) |
5924de0b | 3126 | return 0; |
3127 | ||
3128 | /* If this is an unconditional branch, delete it from the jump_chain of | |
3129 | OLABEL and add it to the jump_chain of NLABEL (assuming both labels | |
3130 | have UID's in range and JUMP_CHAIN is valid). */ | |
3131 | if (jump_chain && (simplejump_p (jump) | |
3132 | || GET_CODE (PATTERN (jump)) == RETURN)) | |
3133 | { | |
3134 | int label_index = nlabel ? INSN_UID (nlabel) : 0; | |
3135 | ||
3136 | delete_from_jump_chain (jump); | |
35e0b416 | 3137 | if (label_index < max_jump_chain |
3138 | && INSN_UID (jump) < max_jump_chain) | |
5924de0b | 3139 | { |
3140 | jump_chain[INSN_UID (jump)] = jump_chain[label_index]; | |
3141 | jump_chain[label_index] = jump; | |
3142 | } | |
3143 | } | |
3144 | ||
3145 | JUMP_LABEL (jump) = nlabel; | |
3146 | if (nlabel) | |
3147 | ++LABEL_NUSES (nlabel); | |
3148 | ||
9cf49039 | 3149 | /* If we're eliding the jump over exception cleanups at the end of a |
3150 | function, move the function end note so that -Wreturn-type works. */ | |
4476207f | 3151 | if (olabel && nlabel |
3152 | && NEXT_INSN (olabel) | |
9cf49039 | 3153 | && GET_CODE (NEXT_INSN (olabel)) == NOTE |
3154 | && NOTE_LINE_NUMBER (NEXT_INSN (olabel)) == NOTE_INSN_FUNCTION_END) | |
3155 | emit_note_after (NOTE_INSN_FUNCTION_END, nlabel); | |
3156 | ||
f8cacb57 | 3157 | if (olabel && --LABEL_NUSES (olabel) == 0 && delete_unused) |
5924de0b | 3158 | delete_insn (olabel); |
3159 | ||
3160 | return 1; | |
3161 | } | |
3162 | ||
7113a566 | 3163 | /* Invert the jump condition of rtx X contained in jump insn, INSN. |
a8b5d014 | 3164 | Accrue the modifications into the change group. */ |
3165 | ||
3166 | static void | |
ba08b7e7 | 3167 | invert_exp_1 (insn) |
a8b5d014 | 3168 | rtx insn; |
3169 | { | |
3170 | register RTX_CODE code; | |
ba08b7e7 | 3171 | rtx x = pc_set (insn); |
3172 | ||
3173 | if (!x) | |
7113a566 | 3174 | abort (); |
ba08b7e7 | 3175 | x = SET_SRC (x); |
a8b5d014 | 3176 | |
3177 | code = GET_CODE (x); | |
3178 | ||
3179 | if (code == IF_THEN_ELSE) | |
3180 | { | |
3181 | register rtx comp = XEXP (x, 0); | |
3182 | register rtx tem; | |
3183 | ||
3184 | /* We can do this in two ways: The preferable way, which can only | |
3185 | be done if this is not an integer comparison, is to reverse | |
3186 | the comparison code. Otherwise, swap the THEN-part and ELSE-part | |
3187 | of the IF_THEN_ELSE. If we can't do either, fail. */ | |
3188 | ||
3189 | if (can_reverse_comparison_p (comp, insn)) | |
3190 | { | |
3191 | validate_change (insn, &XEXP (x, 0), | |
3192 | gen_rtx_fmt_ee (reverse_condition (GET_CODE (comp)), | |
3193 | GET_MODE (comp), XEXP (comp, 0), | |
3194 | XEXP (comp, 1)), | |
3195 | 1); | |
3196 | return; | |
3197 | } | |
7113a566 | 3198 | |
a8b5d014 | 3199 | tem = XEXP (x, 1); |
3200 | validate_change (insn, &XEXP (x, 1), XEXP (x, 2), 1); | |
3201 | validate_change (insn, &XEXP (x, 2), tem, 1); | |
a8b5d014 | 3202 | } |
ba08b7e7 | 3203 | else |
3204 | abort (); | |
a8b5d014 | 3205 | } |
3206 | ||
7113a566 | 3207 | /* Invert the jump condition of conditional jump insn, INSN. |
a8b5d014 | 3208 | |
3209 | Return 1 if we can do so, 0 if we cannot find a way to do so that | |
3210 | matches a pattern. */ | |
3211 | ||
ba08b7e7 | 3212 | static int |
3213 | invert_exp (insn) | |
a8b5d014 | 3214 | rtx insn; |
3215 | { | |
ba08b7e7 | 3216 | invert_exp_1 (insn); |
a8b5d014 | 3217 | if (num_validated_changes () == 0) |
3218 | return 0; | |
3219 | ||
3220 | return apply_change_group (); | |
3221 | } | |
3222 | ||
3223 | /* Invert the condition of the jump JUMP, and make it jump to label | |
3224 | NLABEL instead of where it jumps now. Accrue changes into the | |
3225 | change group. Return false if we didn't see how to perform the | |
3226 | inversion and redirection. */ | |
3227 | ||
3228 | int | |
3229 | invert_jump_1 (jump, nlabel) | |
3230 | rtx jump, nlabel; | |
3231 | { | |
3232 | int ochanges; | |
3233 | ||
3234 | ochanges = num_validated_changes (); | |
ba08b7e7 | 3235 | invert_exp_1 (jump); |
a8b5d014 | 3236 | if (num_validated_changes () == ochanges) |
3237 | return 0; | |
3238 | ||
3239 | return redirect_jump_1 (jump, nlabel); | |
3240 | } | |
3241 | ||
3242 | /* Invert the condition of the jump JUMP, and make it jump to label | |
3243 | NLABEL instead of where it jumps now. Return true if successful. */ | |
3244 | ||
3245 | int | |
f8cacb57 | 3246 | invert_jump (jump, nlabel, delete_unused) |
a8b5d014 | 3247 | rtx jump, nlabel; |
f8cacb57 | 3248 | int delete_unused; |
a8b5d014 | 3249 | { |
3250 | /* We have to either invert the condition and change the label or | |
3251 | do neither. Either operation could fail. We first try to invert | |
3252 | the jump. If that succeeds, we try changing the label. If that fails, | |
3253 | we invert the jump back to what it was. */ | |
3254 | ||
ba08b7e7 | 3255 | if (! invert_exp (jump)) |
a8b5d014 | 3256 | return 0; |
3257 | ||
f8cacb57 | 3258 | if (redirect_jump (jump, nlabel, delete_unused)) |
a8b5d014 | 3259 | { |
3260 | /* An inverted jump means that a probability taken becomes a | |
3261 | probability not taken. Subtract the branch probability from the | |
3262 | probability base to convert it back to a taken probability. */ | |
3263 | ||
3264 | rtx note = find_reg_note (jump, REG_BR_PROB, NULL_RTX); | |
3265 | if (note) | |
3266 | XEXP (note, 0) = GEN_INT (REG_BR_PROB_BASE - INTVAL (XEXP (note, 0))); | |
3267 | ||
3268 | return 1; | |
3269 | } | |
3270 | ||
ba08b7e7 | 3271 | if (! invert_exp (jump)) |
a8b5d014 | 3272 | /* This should just be putting it back the way it was. */ |
3273 | abort (); | |
3274 | ||
3275 | return 0; | |
3276 | } | |
3277 | ||
5924de0b | 3278 | /* Delete the instruction JUMP from any jump chain it might be on. */ |
3279 | ||
3280 | static void | |
3281 | delete_from_jump_chain (jump) | |
3282 | rtx jump; | |
3283 | { | |
3284 | int index; | |
3285 | rtx olabel = JUMP_LABEL (jump); | |
3286 | ||
3287 | /* Handle unconditional jumps. */ | |
3288 | if (jump_chain && olabel != 0 | |
3289 | && INSN_UID (olabel) < max_jump_chain | |
3290 | && simplejump_p (jump)) | |
3291 | index = INSN_UID (olabel); | |
3292 | /* Handle return insns. */ | |
3293 | else if (jump_chain && GET_CODE (PATTERN (jump)) == RETURN) | |
3294 | index = 0; | |
7113a566 | 3295 | else |
3296 | return; | |
5924de0b | 3297 | |
3298 | if (jump_chain[index] == jump) | |
3299 | jump_chain[index] = jump_chain[INSN_UID (jump)]; | |
3300 | else | |
3301 | { | |
3302 | rtx insn; | |
3303 | ||
3304 | for (insn = jump_chain[index]; | |
3305 | insn != 0; | |
3306 | insn = jump_chain[INSN_UID (insn)]) | |
3307 | if (jump_chain[INSN_UID (insn)] == jump) | |
3308 | { | |
3309 | jump_chain[INSN_UID (insn)] = jump_chain[INSN_UID (jump)]; | |
3310 | break; | |
3311 | } | |
3312 | } | |
3313 | } | |
5924de0b | 3314 | \f |
3315 | /* Make jump JUMP jump to label NLABEL, assuming it used to be a tablejump. | |
3316 | ||
3317 | If the old jump target label (before the dispatch table) becomes unused, | |
3318 | it and the dispatch table may be deleted. In that case, find the insn | |
4bbea254 | 3319 | before the jump references that label and delete it and logical successors |
5924de0b | 3320 | too. */ |
3321 | ||
fb374064 | 3322 | static void |
5924de0b | 3323 | redirect_tablejump (jump, nlabel) |
3324 | rtx jump, nlabel; | |
3325 | { | |
3326 | register rtx olabel = JUMP_LABEL (jump); | |
d3df77e9 | 3327 | rtx *notep, note, next; |
5924de0b | 3328 | |
3329 | /* Add this jump to the jump_chain of NLABEL. */ | |
3330 | if (jump_chain && INSN_UID (nlabel) < max_jump_chain | |
3331 | && INSN_UID (jump) < max_jump_chain) | |
3332 | { | |
3333 | jump_chain[INSN_UID (jump)] = jump_chain[INSN_UID (nlabel)]; | |
3334 | jump_chain[INSN_UID (nlabel)] = jump; | |
3335 | } | |
3336 | ||
d3df77e9 | 3337 | for (notep = ®_NOTES (jump), note = *notep; note; note = next) |
3338 | { | |
3339 | next = XEXP (note, 1); | |
3340 | ||
3341 | if (REG_NOTE_KIND (note) != REG_DEAD | |
3342 | /* Verify that the REG_NOTE is legitimate. */ | |
3343 | || GET_CODE (XEXP (note, 0)) != REG | |
3344 | || ! reg_mentioned_p (XEXP (note, 0), PATTERN (jump))) | |
3345 | notep = &XEXP (note, 1); | |
3346 | else | |
3347 | { | |
3348 | delete_prior_computation (note, jump); | |
3349 | *notep = next; | |
3350 | } | |
3351 | } | |
3352 | ||
5924de0b | 3353 | PATTERN (jump) = gen_jump (nlabel); |
3354 | JUMP_LABEL (jump) = nlabel; | |
3355 | ++LABEL_NUSES (nlabel); | |
3356 | INSN_CODE (jump) = -1; | |
3357 | ||
3358 | if (--LABEL_NUSES (olabel) == 0) | |
3359 | { | |
3360 | delete_labelref_insn (jump, olabel, 0); | |
3361 | delete_insn (olabel); | |
3362 | } | |
3363 | } | |
3364 | ||
3365 | /* Find the insn referencing LABEL that is a logical predecessor of INSN. | |
3366 | If we found one, delete it and then delete this insn if DELETE_THIS is | |
3367 | non-zero. Return non-zero if INSN or a predecessor references LABEL. */ | |
3368 | ||
3369 | static int | |
3370 | delete_labelref_insn (insn, label, delete_this) | |
3371 | rtx insn, label; | |
3372 | int delete_this; | |
3373 | { | |
3374 | int deleted = 0; | |
3375 | rtx link; | |
3376 | ||
3377 | if (GET_CODE (insn) != NOTE | |
3378 | && reg_mentioned_p (label, PATTERN (insn))) | |
3379 | { | |
3380 | if (delete_this) | |
3381 | { | |
3382 | delete_insn (insn); | |
3383 | deleted = 1; | |
3384 | } | |
3385 | else | |
3386 | return 1; | |
3387 | } | |
3388 | ||
3389 | for (link = LOG_LINKS (insn); link; link = XEXP (link, 1)) | |
3390 | if (delete_labelref_insn (XEXP (link, 0), label, 1)) | |
3391 | { | |
3392 | if (delete_this) | |
3393 | { | |
3394 | delete_insn (insn); | |
3395 | deleted = 1; | |
3396 | } | |
3397 | else | |
3398 | return 1; | |
3399 | } | |
3400 | ||
3401 | return deleted; | |
3402 | } | |
3403 | \f | |
3404 | /* Like rtx_equal_p except that it considers two REGs as equal | |
6c60c295 | 3405 | if they renumber to the same value and considers two commutative |
3406 | operations to be the same if the order of the operands has been | |
2207ad6a | 3407 | reversed. |
3408 | ||
3409 | ??? Addition is not commutative on the PA due to the weird implicit | |
3410 | space register selection rules for memory addresses. Therefore, we | |
3411 | don't consider a + b == b + a. | |
3412 | ||
3413 | We could/should make this test a little tighter. Possibly only | |
3414 | disabling it on the PA via some backend macro or only disabling this | |
3415 | case when the PLUS is inside a MEM. */ | |
5924de0b | 3416 | |
3417 | int | |
3418 | rtx_renumbered_equal_p (x, y) | |
3419 | rtx x, y; | |
3420 | { | |
3421 | register int i; | |
3422 | register RTX_CODE code = GET_CODE (x); | |
d2ca078f | 3423 | register const char *fmt; |
7113a566 | 3424 | |
5924de0b | 3425 | if (x == y) |
3426 | return 1; | |
6c60c295 | 3427 | |
5924de0b | 3428 | if ((code == REG || (code == SUBREG && GET_CODE (SUBREG_REG (x)) == REG)) |
3429 | && (GET_CODE (y) == REG || (GET_CODE (y) == SUBREG | |
3430 | && GET_CODE (SUBREG_REG (y)) == REG))) | |
3431 | { | |
6c60c295 | 3432 | int reg_x = -1, reg_y = -1; |
3433 | int word_x = 0, word_y = 0; | |
5924de0b | 3434 | |
3435 | if (GET_MODE (x) != GET_MODE (y)) | |
3436 | return 0; | |
3437 | ||
3438 | /* If we haven't done any renumbering, don't | |
3439 | make any assumptions. */ | |
3440 | if (reg_renumber == 0) | |
3441 | return rtx_equal_p (x, y); | |
3442 | ||
3443 | if (code == SUBREG) | |
3444 | { | |
6c60c295 | 3445 | reg_x = REGNO (SUBREG_REG (x)); |
3446 | word_x = SUBREG_WORD (x); | |
3447 | ||
3448 | if (reg_renumber[reg_x] >= 0) | |
3449 | { | |
3450 | reg_x = reg_renumber[reg_x] + word_x; | |
3451 | word_x = 0; | |
3452 | } | |
5924de0b | 3453 | } |
6c60c295 | 3454 | |
5924de0b | 3455 | else |
3456 | { | |
6c60c295 | 3457 | reg_x = REGNO (x); |
3458 | if (reg_renumber[reg_x] >= 0) | |
3459 | reg_x = reg_renumber[reg_x]; | |
5924de0b | 3460 | } |
6c60c295 | 3461 | |
5924de0b | 3462 | if (GET_CODE (y) == SUBREG) |
3463 | { | |
6c60c295 | 3464 | reg_y = REGNO (SUBREG_REG (y)); |
3465 | word_y = SUBREG_WORD (y); | |
3466 | ||
3467 | if (reg_renumber[reg_y] >= 0) | |
3468 | { | |
3469 | reg_y = reg_renumber[reg_y]; | |
3470 | word_y = 0; | |
3471 | } | |
5924de0b | 3472 | } |
6c60c295 | 3473 | |
5924de0b | 3474 | else |
3475 | { | |
6c60c295 | 3476 | reg_y = REGNO (y); |
3477 | if (reg_renumber[reg_y] >= 0) | |
3478 | reg_y = reg_renumber[reg_y]; | |
5924de0b | 3479 | } |
6c60c295 | 3480 | |
3481 | return reg_x >= 0 && reg_x == reg_y && word_x == word_y; | |
5924de0b | 3482 | } |
6c60c295 | 3483 | |
7113a566 | 3484 | /* Now we have disposed of all the cases |
5924de0b | 3485 | in which different rtx codes can match. */ |
3486 | if (code != GET_CODE (y)) | |
3487 | return 0; | |
6c60c295 | 3488 | |
5924de0b | 3489 | switch (code) |
3490 | { | |
3491 | case PC: | |
3492 | case CC0: | |
3493 | case ADDR_VEC: | |
3494 | case ADDR_DIFF_VEC: | |
3495 | return 0; | |
3496 | ||
3497 | case CONST_INT: | |
5fbd420b | 3498 | return INTVAL (x) == INTVAL (y); |
5924de0b | 3499 | |
3500 | case LABEL_REF: | |
f08cae9d | 3501 | /* We can't assume nonlocal labels have their following insns yet. */ |
3502 | if (LABEL_REF_NONLOCAL_P (x) || LABEL_REF_NONLOCAL_P (y)) | |
3503 | return XEXP (x, 0) == XEXP (y, 0); | |
6c60c295 | 3504 | |
5924de0b | 3505 | /* Two label-refs are equivalent if they point at labels |
3506 | in the same position in the instruction stream. */ | |
3507 | return (next_real_insn (XEXP (x, 0)) | |
3508 | == next_real_insn (XEXP (y, 0))); | |
3509 | ||
3510 | case SYMBOL_REF: | |
3511 | return XSTR (x, 0) == XSTR (y, 0); | |
0dbd1c74 | 3512 | |
fc41ccae | 3513 | case CODE_LABEL: |
3514 | /* If we didn't match EQ equality above, they aren't the same. */ | |
3515 | return 0; | |
3516 | ||
0dbd1c74 | 3517 | default: |
3518 | break; | |
5924de0b | 3519 | } |
3520 | ||
3521 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. */ | |
3522 | ||
3523 | if (GET_MODE (x) != GET_MODE (y)) | |
3524 | return 0; | |
3525 | ||
6c60c295 | 3526 | /* For commutative operations, the RTX match if the operand match in any |
2207ad6a | 3527 | order. Also handle the simple binary and unary cases without a loop. |
3528 | ||
3529 | ??? Don't consider PLUS a commutative operator; see comments above. */ | |
3530 | if ((code == EQ || code == NE || GET_RTX_CLASS (code) == 'c') | |
3531 | && code != PLUS) | |
6c60c295 | 3532 | return ((rtx_renumbered_equal_p (XEXP (x, 0), XEXP (y, 0)) |
3533 | && rtx_renumbered_equal_p (XEXP (x, 1), XEXP (y, 1))) | |
3534 | || (rtx_renumbered_equal_p (XEXP (x, 0), XEXP (y, 1)) | |
3535 | && rtx_renumbered_equal_p (XEXP (x, 1), XEXP (y, 0)))); | |
3536 | else if (GET_RTX_CLASS (code) == '<' || GET_RTX_CLASS (code) == '2') | |
3537 | return (rtx_renumbered_equal_p (XEXP (x, 0), XEXP (y, 0)) | |
3538 | && rtx_renumbered_equal_p (XEXP (x, 1), XEXP (y, 1))); | |
3539 | else if (GET_RTX_CLASS (code) == '1') | |
3540 | return rtx_renumbered_equal_p (XEXP (x, 0), XEXP (y, 0)); | |
3541 | ||
5924de0b | 3542 | /* Compare the elements. If any pair of corresponding elements |
3543 | fail to match, return 0 for the whole things. */ | |
3544 | ||
3545 | fmt = GET_RTX_FORMAT (code); | |
3546 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
3547 | { | |
3548 | register int j; | |
3549 | switch (fmt[i]) | |
3550 | { | |
1bb04728 | 3551 | case 'w': |
3552 | if (XWINT (x, i) != XWINT (y, i)) | |
3553 | return 0; | |
3554 | break; | |
3555 | ||
5924de0b | 3556 | case 'i': |
3557 | if (XINT (x, i) != XINT (y, i)) | |
3558 | return 0; | |
3559 | break; | |
3560 | ||
3561 | case 's': | |
3562 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
3563 | return 0; | |
3564 | break; | |
3565 | ||
3566 | case 'e': | |
3567 | if (! rtx_renumbered_equal_p (XEXP (x, i), XEXP (y, i))) | |
3568 | return 0; | |
3569 | break; | |
3570 | ||
3571 | case 'u': | |
3572 | if (XEXP (x, i) != XEXP (y, i)) | |
3573 | return 0; | |
3574 | /* fall through. */ | |
3575 | case '0': | |
3576 | break; | |
3577 | ||
3578 | case 'E': | |
3579 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
3580 | return 0; | |
3581 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
3582 | if (!rtx_renumbered_equal_p (XVECEXP (x, i, j), XVECEXP (y, i, j))) | |
3583 | return 0; | |
3584 | break; | |
3585 | ||
3586 | default: | |
3587 | abort (); | |
3588 | } | |
3589 | } | |
3590 | return 1; | |
3591 | } | |
3592 | \f | |
3593 | /* If X is a hard register or equivalent to one or a subregister of one, | |
3594 | return the hard register number. If X is a pseudo register that was not | |
3595 | assigned a hard register, return the pseudo register number. Otherwise, | |
3596 | return -1. Any rtx is valid for X. */ | |
3597 | ||
3598 | int | |
3599 | true_regnum (x) | |
3600 | rtx x; | |
3601 | { | |
3602 | if (GET_CODE (x) == REG) | |
3603 | { | |
3604 | if (REGNO (x) >= FIRST_PSEUDO_REGISTER && reg_renumber[REGNO (x)] >= 0) | |
3605 | return reg_renumber[REGNO (x)]; | |
3606 | return REGNO (x); | |
3607 | } | |
3608 | if (GET_CODE (x) == SUBREG) | |
3609 | { | |
3610 | int base = true_regnum (SUBREG_REG (x)); | |
3611 | if (base >= 0 && base < FIRST_PSEUDO_REGISTER) | |
3612 | return SUBREG_WORD (x) + base; | |
3613 | } | |
3614 | return -1; | |
3615 | } | |
3616 | \f | |
3617 | /* Optimize code of the form: | |
3618 | ||
3619 | for (x = a[i]; x; ...) | |
3620 | ... | |
3621 | for (x = a[i]; x; ...) | |
3622 | ... | |
3623 | foo: | |
3624 | ||
3625 | Loop optimize will change the above code into | |
3626 | ||
3627 | if (x = a[i]) | |
3628 | for (;;) | |
3629 | { ...; if (! (x = ...)) break; } | |
3630 | if (x = a[i]) | |
3631 | for (;;) | |
3632 | { ...; if (! (x = ...)) break; } | |
3633 | foo: | |
3634 | ||
3635 | In general, if the first test fails, the program can branch | |
3636 | directly to `foo' and skip the second try which is doomed to fail. | |
3637 | We run this after loop optimization and before flow analysis. */ | |
7113a566 | 3638 | |
5924de0b | 3639 | /* When comparing the insn patterns, we track the fact that different |
3640 | pseudo-register numbers may have been used in each computation. | |
3641 | The following array stores an equivalence -- same_regs[I] == J means | |
3642 | that pseudo register I was used in the first set of tests in a context | |
3643 | where J was used in the second set. We also count the number of such | |
3644 | pending equivalences. If nonzero, the expressions really aren't the | |
3645 | same. */ | |
3646 | ||
30d7d56b | 3647 | static int *same_regs; |
5924de0b | 3648 | |
3649 | static int num_same_regs; | |
3650 | ||
3651 | /* Track any registers modified between the target of the first jump and | |
3652 | the second jump. They never compare equal. */ | |
3653 | ||
3654 | static char *modified_regs; | |
3655 | ||
3656 | /* Record if memory was modified. */ | |
3657 | ||
3658 | static int modified_mem; | |
3659 | ||
7113a566 | 3660 | /* Called via note_stores on each insn between the target of the first |
5924de0b | 3661 | branch and the second branch. It marks any changed registers. */ |
3662 | ||
3663 | static void | |
ec8895d7 | 3664 | mark_modified_reg (dest, x, data) |
5924de0b | 3665 | rtx dest; |
0e93a6ac | 3666 | rtx x ATTRIBUTE_UNUSED; |
ec8895d7 | 3667 | void *data ATTRIBUTE_UNUSED; |
5924de0b | 3668 | { |
02e7a332 | 3669 | int regno; |
3670 | unsigned int i; | |
5924de0b | 3671 | |
3672 | if (GET_CODE (dest) == SUBREG) | |
3673 | dest = SUBREG_REG (dest); | |
3674 | ||
3675 | if (GET_CODE (dest) == MEM) | |
3676 | modified_mem = 1; | |
3677 | ||
3678 | if (GET_CODE (dest) != REG) | |
3679 | return; | |
3680 | ||
3681 | regno = REGNO (dest); | |
3682 | if (regno >= FIRST_PSEUDO_REGISTER) | |
3683 | modified_regs[regno] = 1; | |
3684 | else | |
3685 | for (i = 0; i < HARD_REGNO_NREGS (regno, GET_MODE (dest)); i++) | |
3686 | modified_regs[regno + i] = 1; | |
3687 | } | |
3688 | ||
3689 | /* F is the first insn in the chain of insns. */ | |
7113a566 | 3690 | |
5924de0b | 3691 | void |
3e2d414f | 3692 | thread_jumps (f, max_reg, flag_before_loop) |
5924de0b | 3693 | rtx f; |
3694 | int max_reg; | |
3e2d414f | 3695 | int flag_before_loop; |
5924de0b | 3696 | { |
3697 | /* Basic algorithm is to find a conditional branch, | |
3698 | the label it may branch to, and the branch after | |
3699 | that label. If the two branches test the same condition, | |
3700 | walk back from both branch paths until the insn patterns | |
3701 | differ, or code labels are hit. If we make it back to | |
3702 | the target of the first branch, then we know that the first branch | |
3703 | will either always succeed or always fail depending on the relative | |
3704 | senses of the two branches. So adjust the first branch accordingly | |
3705 | in this case. */ | |
7113a566 | 3706 | |
5924de0b | 3707 | rtx label, b1, b2, t1, t2; |
3708 | enum rtx_code code1, code2; | |
3709 | rtx b1op0, b1op1, b2op0, b2op1; | |
3710 | int changed = 1; | |
3711 | int i; | |
30d7d56b | 3712 | int *all_reset; |
5924de0b | 3713 | |
3714 | /* Allocate register tables and quick-reset table. */ | |
8b861be4 | 3715 | modified_regs = (char *) xmalloc (max_reg * sizeof (char)); |
3716 | same_regs = (int *) xmalloc (max_reg * sizeof (int)); | |
3717 | all_reset = (int *) xmalloc (max_reg * sizeof (int)); | |
5924de0b | 3718 | for (i = 0; i < max_reg; i++) |
3719 | all_reset[i] = -1; | |
7113a566 | 3720 | |
5924de0b | 3721 | while (changed) |
3722 | { | |
3723 | changed = 0; | |
3724 | ||
3725 | for (b1 = f; b1; b1 = NEXT_INSN (b1)) | |
3726 | { | |
ba08b7e7 | 3727 | rtx set; |
3728 | rtx set2; | |
7113a566 | 3729 | |
5924de0b | 3730 | /* Get to a candidate branch insn. */ |
3731 | if (GET_CODE (b1) != JUMP_INSN | |
ba08b7e7 | 3732 | || ! any_condjump_p (b1) || JUMP_LABEL (b1) == 0) |
5924de0b | 3733 | continue; |
3734 | ||
93d3b7de | 3735 | memset (modified_regs, 0, max_reg * sizeof (char)); |
5924de0b | 3736 | modified_mem = 0; |
3737 | ||
b1b63592 | 3738 | memcpy (same_regs, all_reset, max_reg * sizeof (int)); |
5924de0b | 3739 | num_same_regs = 0; |
3740 | ||
3741 | label = JUMP_LABEL (b1); | |
3742 | ||
3743 | /* Look for a branch after the target. Record any registers and | |
3744 | memory modified between the target and the branch. Stop when we | |
3745 | get to a label since we can't know what was changed there. */ | |
3746 | for (b2 = NEXT_INSN (label); b2; b2 = NEXT_INSN (b2)) | |
3747 | { | |
3748 | if (GET_CODE (b2) == CODE_LABEL) | |
3749 | break; | |
3750 | ||
3751 | else if (GET_CODE (b2) == JUMP_INSN) | |
3752 | { | |
3753 | /* If this is an unconditional jump and is the only use of | |
3754 | its target label, we can follow it. */ | |
ba08b7e7 | 3755 | if (any_uncondjump_p (b2) |
3756 | && onlyjump_p (b2) | |
5924de0b | 3757 | && JUMP_LABEL (b2) != 0 |
3758 | && LABEL_NUSES (JUMP_LABEL (b2)) == 1) | |
3759 | { | |
3760 | b2 = JUMP_LABEL (b2); | |
3761 | continue; | |
3762 | } | |
3763 | else | |
3764 | break; | |
3765 | } | |
3766 | ||
3767 | if (GET_CODE (b2) != CALL_INSN && GET_CODE (b2) != INSN) | |
3768 | continue; | |
3769 | ||
3770 | if (GET_CODE (b2) == CALL_INSN) | |
3771 | { | |
3772 | modified_mem = 1; | |
3773 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
3774 | if (call_used_regs[i] && ! fixed_regs[i] | |
3775 | && i != STACK_POINTER_REGNUM | |
3776 | && i != FRAME_POINTER_REGNUM | |
c7cac72e | 3777 | && i != HARD_FRAME_POINTER_REGNUM |
5924de0b | 3778 | && i != ARG_POINTER_REGNUM) |
3779 | modified_regs[i] = 1; | |
3780 | } | |
3781 | ||
ec8895d7 | 3782 | note_stores (PATTERN (b2), mark_modified_reg, NULL); |
5924de0b | 3783 | } |
3784 | ||
3785 | /* Check the next candidate branch insn from the label | |
3786 | of the first. */ | |
3787 | if (b2 == 0 | |
3788 | || GET_CODE (b2) != JUMP_INSN | |
3789 | || b2 == b1 | |
ba08b7e7 | 3790 | || !any_condjump_p (b2) |
3791 | || !onlyjump_p (b2)) | |
5924de0b | 3792 | continue; |
ba08b7e7 | 3793 | set = pc_set (b1); |
3794 | set2 = pc_set (b2); | |
5924de0b | 3795 | |
3796 | /* Get the comparison codes and operands, reversing the | |
3797 | codes if appropriate. If we don't have comparison codes, | |
3798 | we can't do anything. */ | |
ba08b7e7 | 3799 | b1op0 = XEXP (XEXP (SET_SRC (set), 0), 0); |
3800 | b1op1 = XEXP (XEXP (SET_SRC (set), 0), 1); | |
3801 | code1 = GET_CODE (XEXP (SET_SRC (set), 0)); | |
3802 | if (XEXP (SET_SRC (set), 1) == pc_rtx) | |
5924de0b | 3803 | code1 = reverse_condition (code1); |
3804 | ||
ba08b7e7 | 3805 | b2op0 = XEXP (XEXP (SET_SRC (set2), 0), 0); |
3806 | b2op1 = XEXP (XEXP (SET_SRC (set2), 0), 1); | |
3807 | code2 = GET_CODE (XEXP (SET_SRC (set2), 0)); | |
3808 | if (XEXP (SET_SRC (set2), 1) == pc_rtx) | |
5924de0b | 3809 | code2 = reverse_condition (code2); |
3810 | ||
3811 | /* If they test the same things and knowing that B1 branches | |
3812 | tells us whether or not B2 branches, check if we | |
3813 | can thread the branch. */ | |
3814 | if (rtx_equal_for_thread_p (b1op0, b2op0, b2) | |
3815 | && rtx_equal_for_thread_p (b1op1, b2op1, b2) | |
3816 | && (comparison_dominates_p (code1, code2) | |
ba08b7e7 | 3817 | || (can_reverse_comparison_p (XEXP (SET_SRC (set), 0), b1) |
7113a566 | 3818 | && comparison_dominates_p (code1, |
3819 | reverse_condition (code2))))) | |
a4110d9a | 3820 | |
5924de0b | 3821 | { |
3822 | t1 = prev_nonnote_insn (b1); | |
3823 | t2 = prev_nonnote_insn (b2); | |
7113a566 | 3824 | |
5924de0b | 3825 | while (t1 != 0 && t2 != 0) |
3826 | { | |
5924de0b | 3827 | if (t2 == label) |
3828 | { | |
3829 | /* We have reached the target of the first branch. | |
3830 | If there are no pending register equivalents, | |
3831 | we know that this branch will either always | |
3832 | succeed (if the senses of the two branches are | |
3833 | the same) or always fail (if not). */ | |
3834 | rtx new_label; | |
3835 | ||
3836 | if (num_same_regs != 0) | |
3837 | break; | |
3838 | ||
3839 | if (comparison_dominates_p (code1, code2)) | |
7113a566 | 3840 | new_label = JUMP_LABEL (b2); |
5924de0b | 3841 | else |
3842 | new_label = get_label_after (b2); | |
3843 | ||
3e2d414f | 3844 | if (JUMP_LABEL (b1) != new_label) |
3845 | { | |
3846 | rtx prev = PREV_INSN (new_label); | |
3847 | ||
3848 | if (flag_before_loop | |
2d9da7e1 | 3849 | && GET_CODE (prev) == NOTE |
3e2d414f | 3850 | && NOTE_LINE_NUMBER (prev) == NOTE_INSN_LOOP_BEG) |
3851 | { | |
3852 | /* Don't thread to the loop label. If a loop | |
3853 | label is reused, loop optimization will | |
3854 | be disabled for that loop. */ | |
3855 | new_label = gen_label_rtx (); | |
3856 | emit_label_after (new_label, PREV_INSN (prev)); | |
3857 | } | |
f8cacb57 | 3858 | changed |= redirect_jump (b1, new_label, 1); |
3e2d414f | 3859 | } |
5924de0b | 3860 | break; |
3861 | } | |
7113a566 | 3862 | |
5924de0b | 3863 | /* If either of these is not a normal insn (it might be |
3864 | a JUMP_INSN, CALL_INSN, or CODE_LABEL) we fail. (NOTEs | |
3865 | have already been skipped above.) Similarly, fail | |
3866 | if the insns are different. */ | |
3867 | if (GET_CODE (t1) != INSN || GET_CODE (t2) != INSN | |
3868 | || recog_memoized (t1) != recog_memoized (t2) | |
3869 | || ! rtx_equal_for_thread_p (PATTERN (t1), | |
3870 | PATTERN (t2), t2)) | |
3871 | break; | |
7113a566 | 3872 | |
5924de0b | 3873 | t1 = prev_nonnote_insn (t1); |
3874 | t2 = prev_nonnote_insn (t2); | |
3875 | } | |
3876 | } | |
3877 | } | |
3878 | } | |
8b861be4 | 3879 | |
3880 | /* Clean up. */ | |
3881 | free (modified_regs); | |
3882 | free (same_regs); | |
3883 | free (all_reset); | |
5924de0b | 3884 | } |
3885 | \f | |
3886 | /* This is like RTX_EQUAL_P except that it knows about our handling of | |
3887 | possibly equivalent registers and knows to consider volatile and | |
3888 | modified objects as not equal. | |
7113a566 | 3889 | |
5924de0b | 3890 | YINSN is the insn containing Y. */ |
3891 | ||
3892 | int | |
3893 | rtx_equal_for_thread_p (x, y, yinsn) | |
3894 | rtx x, y; | |
3895 | rtx yinsn; | |
3896 | { | |
3897 | register int i; | |
3898 | register int j; | |
3899 | register enum rtx_code code; | |
d2ca078f | 3900 | register const char *fmt; |
5924de0b | 3901 | |
3902 | code = GET_CODE (x); | |
3903 | /* Rtx's of different codes cannot be equal. */ | |
3904 | if (code != GET_CODE (y)) | |
3905 | return 0; | |
3906 | ||
3907 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. | |
3908 | (REG:SI x) and (REG:HI x) are NOT equivalent. */ | |
3909 | ||
3910 | if (GET_MODE (x) != GET_MODE (y)) | |
3911 | return 0; | |
3912 | ||
968ae6d5 | 3913 | /* For floating-point, consider everything unequal. This is a bit |
3914 | pessimistic, but this pass would only rarely do anything for FP | |
3915 | anyway. */ | |
3916 | if (TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT | |
3917 | && FLOAT_MODE_P (GET_MODE (x)) && ! flag_fast_math) | |
3918 | return 0; | |
3919 | ||
a8cc57a8 | 3920 | /* For commutative operations, the RTX match if the operand match in any |
3921 | order. Also handle the simple binary and unary cases without a loop. */ | |
3922 | if (code == EQ || code == NE || GET_RTX_CLASS (code) == 'c') | |
e81f0781 | 3923 | return ((rtx_equal_for_thread_p (XEXP (x, 0), XEXP (y, 0), yinsn) |
3924 | && rtx_equal_for_thread_p (XEXP (x, 1), XEXP (y, 1), yinsn)) | |
3925 | || (rtx_equal_for_thread_p (XEXP (x, 0), XEXP (y, 1), yinsn) | |
3926 | && rtx_equal_for_thread_p (XEXP (x, 1), XEXP (y, 0), yinsn))); | |
a8cc57a8 | 3927 | else if (GET_RTX_CLASS (code) == '<' || GET_RTX_CLASS (code) == '2') |
e81f0781 | 3928 | return (rtx_equal_for_thread_p (XEXP (x, 0), XEXP (y, 0), yinsn) |
3929 | && rtx_equal_for_thread_p (XEXP (x, 1), XEXP (y, 1), yinsn)); | |
a8cc57a8 | 3930 | else if (GET_RTX_CLASS (code) == '1') |
e81f0781 | 3931 | return rtx_equal_for_thread_p (XEXP (x, 0), XEXP (y, 0), yinsn); |
a8cc57a8 | 3932 | |
5924de0b | 3933 | /* Handle special-cases first. */ |
3934 | switch (code) | |
3935 | { | |
3936 | case REG: | |
3937 | if (REGNO (x) == REGNO (y) && ! modified_regs[REGNO (x)]) | |
3938 | return 1; | |
3939 | ||
3940 | /* If neither is user variable or hard register, check for possible | |
3941 | equivalence. */ | |
3942 | if (REG_USERVAR_P (x) || REG_USERVAR_P (y) | |
3943 | || REGNO (x) < FIRST_PSEUDO_REGISTER | |
3944 | || REGNO (y) < FIRST_PSEUDO_REGISTER) | |
3945 | return 0; | |
3946 | ||
3947 | if (same_regs[REGNO (x)] == -1) | |
3948 | { | |
3949 | same_regs[REGNO (x)] = REGNO (y); | |
3950 | num_same_regs++; | |
3951 | ||
3952 | /* If this is the first time we are seeing a register on the `Y' | |
7113a566 | 3953 | side, see if it is the last use. If not, we can't thread the |
5924de0b | 3954 | jump, so mark it as not equivalent. */ |
394685a4 | 3955 | if (REGNO_LAST_UID (REGNO (y)) != INSN_UID (yinsn)) |
5924de0b | 3956 | return 0; |
3957 | ||
3958 | return 1; | |
3959 | } | |
3960 | else | |
02e7a332 | 3961 | return (same_regs[REGNO (x)] == (int) REGNO (y)); |
5924de0b | 3962 | |
3963 | break; | |
3964 | ||
3965 | case MEM: | |
4bbea254 | 3966 | /* If memory modified or either volatile, not equivalent. |
a92771b8 | 3967 | Else, check address. */ |
5924de0b | 3968 | if (modified_mem || MEM_VOLATILE_P (x) || MEM_VOLATILE_P (y)) |
3969 | return 0; | |
3970 | ||
3971 | return rtx_equal_for_thread_p (XEXP (x, 0), XEXP (y, 0), yinsn); | |
3972 | ||
3973 | case ASM_INPUT: | |
3974 | if (MEM_VOLATILE_P (x) || MEM_VOLATILE_P (y)) | |
3975 | return 0; | |
3976 | ||
3977 | break; | |
3978 | ||
3979 | case SET: | |
3980 | /* Cancel a pending `same_regs' if setting equivalenced registers. | |
3981 | Then process source. */ | |
3982 | if (GET_CODE (SET_DEST (x)) == REG | |
3983 | && GET_CODE (SET_DEST (y)) == REG) | |
3984 | { | |
7113a566 | 3985 | if (same_regs[REGNO (SET_DEST (x))] == (int) REGNO (SET_DEST (y))) |
5924de0b | 3986 | { |
3987 | same_regs[REGNO (SET_DEST (x))] = -1; | |
3988 | num_same_regs--; | |
3989 | } | |
3990 | else if (REGNO (SET_DEST (x)) != REGNO (SET_DEST (y))) | |
3991 | return 0; | |
3992 | } | |
3993 | else | |
7113a566 | 3994 | { |
3995 | if (rtx_equal_for_thread_p (SET_DEST (x), SET_DEST (y), yinsn) == 0) | |
3996 | return 0; | |
3997 | } | |
5924de0b | 3998 | |
3999 | return rtx_equal_for_thread_p (SET_SRC (x), SET_SRC (y), yinsn); | |
4000 | ||
4001 | case LABEL_REF: | |
4002 | return XEXP (x, 0) == XEXP (y, 0); | |
4003 | ||
4004 | case SYMBOL_REF: | |
4005 | return XSTR (x, 0) == XSTR (y, 0); | |
7113a566 | 4006 | |
0dbd1c74 | 4007 | default: |
4008 | break; | |
5924de0b | 4009 | } |
4010 | ||
4011 | if (x == y) | |
4012 | return 1; | |
4013 | ||
4014 | fmt = GET_RTX_FORMAT (code); | |
4015 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
4016 | { | |
4017 | switch (fmt[i]) | |
4018 | { | |
1bb04728 | 4019 | case 'w': |
4020 | if (XWINT (x, i) != XWINT (y, i)) | |
4021 | return 0; | |
4022 | break; | |
4023 | ||
5924de0b | 4024 | case 'n': |
4025 | case 'i': | |
4026 | if (XINT (x, i) != XINT (y, i)) | |
4027 | return 0; | |
4028 | break; | |
4029 | ||
4030 | case 'V': | |
4031 | case 'E': | |
4032 | /* Two vectors must have the same length. */ | |
4033 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
4034 | return 0; | |
4035 | ||
4036 | /* And the corresponding elements must match. */ | |
4037 | for (j = 0; j < XVECLEN (x, i); j++) | |
4038 | if (rtx_equal_for_thread_p (XVECEXP (x, i, j), | |
7113a566 | 4039 | XVECEXP (y, i, j), yinsn) == 0) |
5924de0b | 4040 | return 0; |
4041 | break; | |
4042 | ||
4043 | case 'e': | |
4044 | if (rtx_equal_for_thread_p (XEXP (x, i), XEXP (y, i), yinsn) == 0) | |
4045 | return 0; | |
4046 | break; | |
4047 | ||
4048 | case 'S': | |
4049 | case 's': | |
4050 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
4051 | return 0; | |
4052 | break; | |
4053 | ||
4054 | case 'u': | |
4055 | /* These are just backpointers, so they don't matter. */ | |
4056 | break; | |
4057 | ||
4058 | case '0': | |
a4070a91 | 4059 | case 't': |
5924de0b | 4060 | break; |
4061 | ||
4062 | /* It is believed that rtx's at this level will never | |
4063 | contain anything but integers and other rtx's, | |
4064 | except for within LABEL_REFs and SYMBOL_REFs. */ | |
4065 | default: | |
4066 | abort (); | |
4067 | } | |
4068 | } | |
4069 | return 1; | |
4070 | } |