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75040552 | 1 | /* Perform instruction reorganizations for delay slot filling. |
d353bf18 | 2 | Copyright (C) 1992-2015 Free Software Foundation, Inc. |
02b3d2b6 | 3 | Contributed by Richard Kenner (kenner@vlsi1.ultra.nyu.edu). |
75040552 | 4 | Hacked by Michael Tiemann (tiemann@cygnus.com). |
5 | ||
f12b58b3 | 6 | This file is part of GCC. |
75040552 | 7 | |
f12b58b3 | 8 | GCC is free software; you can redistribute it and/or modify it under |
9 | the terms of the GNU General Public License as published by the Free | |
8c4c00c1 | 10 | Software Foundation; either version 3, or (at your option) any later |
f12b58b3 | 11 | version. |
75040552 | 12 | |
f12b58b3 | 13 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
14 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
75040552 | 17 | |
18 | You should have received a copy of the GNU General Public License | |
8c4c00c1 | 19 | along with GCC; see the file COPYING3. If not see |
20 | <http://www.gnu.org/licenses/>. */ | |
75040552 | 21 | |
75040552 | 22 | /* Instruction reorganization pass. |
23 | ||
24 | This pass runs after register allocation and final jump | |
25 | optimization. It should be the last pass to run before peephole. | |
26 | It serves primarily to fill delay slots of insns, typically branch | |
27 | and call insns. Other insns typically involve more complicated | |
4bbea254 | 28 | interactions of data dependencies and resource constraints, and |
75040552 | 29 | are better handled by scheduling before register allocation (by the |
30 | function `schedule_insns'). | |
31 | ||
32 | The Branch Penalty is the number of extra cycles that are needed to | |
33 | execute a branch insn. On an ideal machine, branches take a single | |
34 | cycle, and the Branch Penalty is 0. Several RISC machines approach | |
35 | branch delays differently: | |
36 | ||
ea1d1c38 | 37 | The MIPS has a single branch delay slot. Most insns |
75040552 | 38 | (except other branches) can be used to fill this slot. When the |
39 | slot is filled, two insns execute in two cycles, reducing the | |
40 | branch penalty to zero. | |
41 | ||
75040552 | 42 | The SPARC always has a branch delay slot, but its effects can be |
43 | annulled when the branch is not taken. This means that failing to | |
44 | find other sources of insns, we can hoist an insn from the branch | |
45 | target that would only be safe to execute knowing that the branch | |
46 | is taken. | |
47 | ||
45c67dee | 48 | The HP-PA always has a branch delay slot. For unconditional branches |
875b3f3b | 49 | its effects can be annulled when the branch is taken. The effects |
45c67dee | 50 | of the delay slot in a conditional branch can be nullified for forward |
51 | taken branches, or for untaken backward branches. This means | |
52 | we can hoist insns from the fall-through path for forward branches or | |
53 | steal insns from the target of backward branches. | |
54 | ||
86236ca9 | 55 | The TMS320C3x and C4x have three branch delay slots. When the three |
56 | slots are filled, the branch penalty is zero. Most insns can fill the | |
57 | delay slots except jump insns. | |
58 | ||
75040552 | 59 | Three techniques for filling delay slots have been implemented so far: |
60 | ||
61 | (1) `fill_simple_delay_slots' is the simplest, most efficient way | |
62 | to fill delay slots. This pass first looks for insns which come | |
63 | from before the branch and which are safe to execute after the | |
64 | branch. Then it searches after the insn requiring delay slots or, | |
65 | in the case of a branch, for insns that are after the point at | |
66 | which the branch merges into the fallthrough code, if such a point | |
67 | exists. When such insns are found, the branch penalty decreases | |
68 | and no code expansion takes place. | |
69 | ||
70 | (2) `fill_eager_delay_slots' is more complicated: it is used for | |
71 | scheduling conditional jumps, or for scheduling jumps which cannot | |
72 | be filled using (1). A machine need not have annulled jumps to use | |
73 | this strategy, but it helps (by keeping more options open). | |
74 | `fill_eager_delay_slots' tries to guess the direction the branch | |
75 | will go; if it guesses right 100% of the time, it can reduce the | |
fba5c27c | 76 | branch penalty as much as `fill_simple_delay_slots' does. If it |
ea1d1c38 | 77 | guesses wrong 100% of the time, it might as well schedule nops. When |
75040552 | 78 | `fill_eager_delay_slots' takes insns from the fall-through path of |
79 | the jump, usually there is no code expansion; when it takes insns | |
80 | from the branch target, there is code expansion if it is not the | |
81 | only way to reach that target. | |
82 | ||
83 | (3) `relax_delay_slots' uses a set of rules to simplify code that | |
84 | has been reorganized by (1) and (2). It finds cases where | |
85 | conditional test can be eliminated, jumps can be threaded, extra | |
86 | insns can be eliminated, etc. It is the job of (1) and (2) to do a | |
87 | good job of scheduling locally; `relax_delay_slots' takes care of | |
88 | making the various individual schedules work well together. It is | |
89 | especially tuned to handle the control flow interactions of branch | |
90 | insns. It does nothing for insns with delay slots that do not | |
91 | branch. | |
92 | ||
93 | On machines that use CC0, we are very conservative. We will not make | |
94 | a copy of an insn involving CC0 since we want to maintain a 1-1 | |
f9e15121 | 95 | correspondence between the insn that sets and uses CC0. The insns are |
75040552 | 96 | allowed to be separated by placing an insn that sets CC0 (but not an insn |
97 | that uses CC0; we could do this, but it doesn't seem worthwhile) in a | |
98 | delay slot. In that case, we point each insn at the other with REG_CC_USER | |
99 | and REG_CC_SETTER notes. Note that these restrictions affect very few | |
100 | machines because most RISC machines with delay slots will not use CC0 | |
5ff3bbb5 | 101 | (the RT is the only known exception at this point). */ |
75040552 | 102 | |
75040552 | 103 | #include "config.h" |
405711de | 104 | #include "system.h" |
805e22b2 | 105 | #include "coretypes.h" |
9ef16211 | 106 | #include "backend.h" |
7c29e30e | 107 | #include "target.h" |
75040552 | 108 | #include "rtl.h" |
7c29e30e | 109 | #include "tree.h" |
110 | #include "predict.h" | |
9ef16211 | 111 | #include "df.h" |
7953c610 | 112 | #include "tm_p.h" |
7c29e30e | 113 | #include "expmed.h" |
114 | #include "insn-config.h" | |
115 | #include "regs.h" | |
116 | #include "emit-rtl.h" | |
117 | #include "recog.h" | |
118 | #include "diagnostic-core.h" | |
d53441c8 | 119 | #include "flags.h" |
d53441c8 | 120 | #include "alias.h" |
d53441c8 | 121 | #include "dojump.h" |
122 | #include "explow.h" | |
123 | #include "calls.h" | |
d53441c8 | 124 | #include "varasm.h" |
125 | #include "stmt.h" | |
126 | #include "expr.h" | |
75040552 | 127 | #include "conditions.h" |
ce671537 | 128 | #include "insn-attr.h" |
29bd1808 | 129 | #include "resource.h" |
cb9dac39 | 130 | #include "except.h" |
21b80b12 | 131 | #include "params.h" |
77fce4cd | 132 | #include "tree-pass.h" |
ce671537 | 133 | |
9d853199 | 134 | \f |
135 | /* First, some functions that were used before GCC got a control flow graph. | |
136 | These functions are now only used here in reorg.c, and have therefore | |
137 | been moved here to avoid inadvertent misuse elsewhere in the compiler. */ | |
138 | ||
139 | /* Return the last label to mark the same position as LABEL. Return LABEL | |
140 | itself if it is null or any return rtx. */ | |
141 | ||
c2c03a95 | 142 | static rtx |
143 | skip_consecutive_labels (rtx label_or_return) | |
9d853199 | 144 | { |
575a12f2 | 145 | rtx_insn *insn; |
9d853199 | 146 | |
c2c03a95 | 147 | if (label_or_return && ANY_RETURN_P (label_or_return)) |
148 | return label_or_return; | |
149 | ||
150 | rtx_insn *label = as_a <rtx_insn *> (label_or_return); | |
9d853199 | 151 | |
152 | for (insn = label; insn != 0 && !INSN_P (insn); insn = NEXT_INSN (insn)) | |
153 | if (LABEL_P (insn)) | |
154 | label = insn; | |
155 | ||
156 | return label; | |
157 | } | |
158 | ||
159 | /* INSN uses CC0 and is being moved into a delay slot. Set up REG_CC_SETTER | |
160 | and REG_CC_USER notes so we can find it. */ | |
161 | ||
162 | static void | |
f6860e7f | 163 | link_cc0_insns (rtx_insn *insn) |
9d853199 | 164 | { |
165 | rtx user = next_nonnote_insn (insn); | |
166 | ||
167 | if (NONJUMP_INSN_P (user) && GET_CODE (PATTERN (user)) == SEQUENCE) | |
168 | user = XVECEXP (PATTERN (user), 0, 0); | |
169 | ||
170 | add_reg_note (user, REG_CC_SETTER, insn); | |
171 | add_reg_note (insn, REG_CC_USER, user); | |
172 | } | |
173 | \f | |
75040552 | 174 | /* Insns which have delay slots that have not yet been filled. */ |
175 | ||
176 | static struct obstack unfilled_slots_obstack; | |
177 | static rtx *unfilled_firstobj; | |
178 | ||
179 | /* Define macros to refer to the first and last slot containing unfilled | |
180 | insns. These are used because the list may move and its address | |
181 | should be recomputed at each use. */ | |
182 | ||
183 | #define unfilled_slots_base \ | |
575a12f2 | 184 | ((rtx_insn **) obstack_base (&unfilled_slots_obstack)) |
75040552 | 185 | |
186 | #define unfilled_slots_next \ | |
575a12f2 | 187 | ((rtx_insn **) obstack_next_free (&unfilled_slots_obstack)) |
75040552 | 188 | |
9cb2517e | 189 | /* Points to the label before the end of the function, or before a |
190 | return insn. */ | |
575a12f2 | 191 | static rtx_code_label *function_return_label; |
9cb2517e | 192 | /* Likewise for a simple_return. */ |
575a12f2 | 193 | static rtx_code_label *function_simple_return_label; |
75040552 | 194 | |
75040552 | 195 | /* Mapping between INSN_UID's and position in the code since INSN_UID's do |
196 | not always monotonically increase. */ | |
197 | static int *uid_to_ruid; | |
198 | ||
199 | /* Highest valid index in `uid_to_ruid'. */ | |
200 | static int max_uid; | |
201 | ||
31886f96 | 202 | static int stop_search_p (rtx_insn *, int); |
3ad4992f | 203 | static int resource_conflicts_p (struct resources *, struct resources *); |
10a15ee4 | 204 | static int insn_references_resource_p (rtx, struct resources *, bool); |
205 | static int insn_sets_resource_p (rtx, struct resources *, bool); | |
575a12f2 | 206 | static rtx_code_label *find_end_label (rtx); |
28cb74c5 | 207 | static rtx_insn *emit_delay_sequence (rtx_insn *, const vec<rtx_insn *> &, |
208 | int); | |
209 | static void add_to_delay_list (rtx_insn *, vec<rtx_insn *> *); | |
575a12f2 | 210 | static rtx_insn *delete_from_delay_slot (rtx_insn *); |
2cf26c51 | 211 | static void delete_scheduled_jump (rtx_insn *); |
3ad4992f | 212 | static void note_delay_statistics (int, int); |
93ee8dfb | 213 | static int get_jump_flags (const rtx_insn *, rtx); |
9ddd9ef9 | 214 | static int mostly_true_jump (rtx); |
93ee8dfb | 215 | static rtx get_branch_condition (const rtx_insn *, rtx); |
216 | static int condition_dominates_p (rtx, const rtx_insn *); | |
91a55c11 | 217 | static int redirect_with_delay_slots_safe_p (rtx_insn *, rtx, rtx); |
28cb74c5 | 218 | static int redirect_with_delay_list_safe_p (rtx_insn *, rtx, |
219 | const vec<rtx_insn *> &); | |
220 | static int check_annul_list_true_false (int, const vec<rtx_insn *> &); | |
221 | static void steal_delay_list_from_target (rtx_insn *, rtx, rtx_sequence *, | |
222 | vec<rtx_insn *> *, | |
223 | struct resources *, | |
224 | struct resources *, | |
225 | struct resources *, | |
226 | int, int *, int *, | |
227 | rtx *); | |
228 | static void steal_delay_list_from_fallthrough (rtx_insn *, rtx, rtx_sequence *, | |
229 | vec<rtx_insn *> *, | |
230 | struct resources *, | |
231 | struct resources *, | |
232 | struct resources *, | |
233 | int, int *, int *); | |
f6860e7f | 234 | static void try_merge_delay_insns (rtx_insn *, rtx_insn *); |
28cb74c5 | 235 | static rtx redundant_insn (rtx, rtx_insn *, const vec<rtx_insn *> &); |
c2c03a95 | 236 | static int own_thread_p (rtx, rtx, int); |
2cf26c51 | 237 | static void update_block (rtx_insn *, rtx); |
f9a00e9e | 238 | static int reorg_redirect_jump (rtx_jump_insn *, rtx); |
f6860e7f | 239 | static void update_reg_dead_notes (rtx_insn *, rtx_insn *); |
3ad4992f | 240 | static void fix_reg_dead_note (rtx, rtx); |
241 | static void update_reg_unused_notes (rtx, rtx); | |
242 | static void fill_simple_delay_slots (int); | |
28cb74c5 | 243 | static void fill_slots_from_thread (rtx_jump_insn *, rtx, rtx, rtx, |
244 | int, int, int, int, | |
245 | int *, vec<rtx_insn *> *); | |
3ad4992f | 246 | static void fill_eager_delay_slots (void); |
575a12f2 | 247 | static void relax_delay_slots (rtx_insn *); |
91a55c11 | 248 | static void make_return_insns (rtx_insn *); |
75040552 | 249 | \f |
4115ac36 | 250 | /* A wrapper around next_active_insn which takes care to return ret_rtx |
251 | unchanged. */ | |
252 | ||
c2c03a95 | 253 | static rtx |
254 | first_active_target_insn (rtx insn) | |
4115ac36 | 255 | { |
256 | if (ANY_RETURN_P (insn)) | |
257 | return insn; | |
c2c03a95 | 258 | return next_active_insn (as_a <rtx_insn *> (insn)); |
4115ac36 | 259 | } |
260 | \f | |
9cb2517e | 261 | /* Return true iff INSN is a simplejump, or any kind of return insn. */ |
262 | ||
263 | static bool | |
264 | simplejump_or_return_p (rtx insn) | |
265 | { | |
266 | return (JUMP_P (insn) | |
93ee8dfb | 267 | && (simplejump_p (as_a <rtx_insn *> (insn)) |
268 | || ANY_RETURN_P (PATTERN (insn)))); | |
9cb2517e | 269 | } |
270 | \f | |
75040552 | 271 | /* Return TRUE if this insn should stop the search for insn to fill delay |
272 | slots. LABELS_P indicates that labels should terminate the search. | |
273 | In all cases, jumps terminate the search. */ | |
274 | ||
275 | static int | |
31886f96 | 276 | stop_search_p (rtx_insn *insn, int labels_p) |
75040552 | 277 | { |
278 | if (insn == 0) | |
279 | return 1; | |
280 | ||
9ef1d65a | 281 | /* If the insn can throw an exception that is caught within the function, |
282 | it may effectively perform a jump from the viewpoint of the function. | |
283 | Therefore act like for a jump. */ | |
284 | if (can_throw_internal (insn)) | |
285 | return 1; | |
286 | ||
75040552 | 287 | switch (GET_CODE (insn)) |
288 | { | |
289 | case NOTE: | |
290 | case CALL_INSN: | |
291 | return 0; | |
292 | ||
293 | case CODE_LABEL: | |
294 | return labels_p; | |
295 | ||
296 | case JUMP_INSN: | |
297 | case BARRIER: | |
298 | return 1; | |
299 | ||
300 | case INSN: | |
301 | /* OK unless it contains a delay slot or is an `asm' insn of some type. | |
302 | We don't know anything about these. */ | |
303 | return (GET_CODE (PATTERN (insn)) == SEQUENCE | |
304 | || GET_CODE (PATTERN (insn)) == ASM_INPUT | |
305 | || asm_noperands (PATTERN (insn)) >= 0); | |
306 | ||
307 | default: | |
04e579b6 | 308 | gcc_unreachable (); |
75040552 | 309 | } |
310 | } | |
311 | \f | |
312 | /* Return TRUE if any resources are marked in both RES1 and RES2 or if either | |
313 | resource set contains a volatile memory reference. Otherwise, return FALSE. */ | |
314 | ||
315 | static int | |
3ad4992f | 316 | resource_conflicts_p (struct resources *res1, struct resources *res2) |
75040552 | 317 | { |
318 | if ((res1->cc && res2->cc) || (res1->memory && res2->memory) | |
319 | || res1->volatil || res2->volatil) | |
320 | return 1; | |
321 | ||
9ddd9ef9 | 322 | return hard_reg_set_intersect_p (res1->regs, res2->regs); |
75040552 | 323 | } |
324 | ||
325 | /* Return TRUE if any resource marked in RES, a `struct resources', is | |
37c4d6c2 | 326 | referenced by INSN. If INCLUDE_DELAYED_EFFECTS is set, return if the called |
75040552 | 327 | routine is using those resources. |
328 | ||
329 | We compute this by computing all the resources referenced by INSN and | |
330 | seeing if this conflicts with RES. It might be faster to directly check | |
331 | ourselves, and this is the way it used to work, but it means duplicating | |
332 | a large block of complex code. */ | |
333 | ||
334 | static int | |
3ad4992f | 335 | insn_references_resource_p (rtx insn, struct resources *res, |
10a15ee4 | 336 | bool include_delayed_effects) |
75040552 | 337 | { |
338 | struct resources insn_res; | |
339 | ||
340 | CLEAR_RESOURCE (&insn_res); | |
5e7b80f9 | 341 | mark_referenced_resources (insn, &insn_res, include_delayed_effects); |
75040552 | 342 | return resource_conflicts_p (&insn_res, res); |
343 | } | |
344 | ||
345 | /* Return TRUE if INSN modifies resources that are marked in RES. | |
37c4d6c2 | 346 | INCLUDE_DELAYED_EFFECTS is set if the actions of that routine should be |
75040552 | 347 | included. CC0 is only modified if it is explicitly set; see comments |
348 | in front of mark_set_resources for details. */ | |
349 | ||
350 | static int | |
3ad4992f | 351 | insn_sets_resource_p (rtx insn, struct resources *res, |
10a15ee4 | 352 | bool include_delayed_effects) |
75040552 | 353 | { |
354 | struct resources insn_sets; | |
355 | ||
356 | CLEAR_RESOURCE (&insn_sets); | |
b9c74b4d | 357 | mark_set_resources (insn, &insn_sets, 0, |
358 | (include_delayed_effects | |
359 | ? MARK_SRC_DEST_CALL | |
360 | : MARK_SRC_DEST)); | |
75040552 | 361 | return resource_conflicts_p (&insn_sets, res); |
362 | } | |
363 | \f | |
920d6e22 | 364 | /* Find a label at the end of the function or before a RETURN. If there |
365 | is none, try to make one. If that fails, returns 0. | |
366 | ||
367 | The property of such a label is that it is placed just before the | |
368 | epilogue or a bare RETURN insn, so that another bare RETURN can be | |
369 | turned into a jump to the label unconditionally. In particular, the | |
370 | label cannot be placed before a RETURN insn with a filled delay slot. | |
371 | ||
372 | ??? There may be a problem with the current implementation. Suppose | |
373 | we start with a bare RETURN insn and call find_end_label. It may set | |
9cb2517e | 374 | function_return_label just before the RETURN. Suppose the machinery |
920d6e22 | 375 | is able to fill the delay slot of the RETURN insn afterwards. Then |
9cb2517e | 376 | function_return_label is no longer valid according to the property |
920d6e22 | 377 | described above and find_end_label will still return it unmodified. |
378 | Note that this is probably mitigated by the following observation: | |
9cb2517e | 379 | once function_return_label is made, it is very likely the target of |
920d6e22 | 380 | a jump, so filling the delay slot of the RETURN will be much more |
9cb2517e | 381 | difficult. |
382 | KIND is either simple_return_rtx or ret_rtx, indicating which type of | |
383 | return we're looking for. */ | |
75040552 | 384 | |
575a12f2 | 385 | static rtx_code_label * |
9cb2517e | 386 | find_end_label (rtx kind) |
75040552 | 387 | { |
575a12f2 | 388 | rtx_insn *insn; |
389 | rtx_code_label **plabel; | |
9cb2517e | 390 | |
391 | if (kind == ret_rtx) | |
392 | plabel = &function_return_label; | |
393 | else | |
394 | { | |
395 | gcc_assert (kind == simple_return_rtx); | |
396 | plabel = &function_simple_return_label; | |
397 | } | |
75040552 | 398 | |
399 | /* If we found one previously, return it. */ | |
9cb2517e | 400 | if (*plabel) |
401 | return *plabel; | |
75040552 | 402 | |
403 | /* Otherwise, see if there is a label at the end of the function. If there | |
404 | is, it must be that RETURN insns aren't needed, so that is our return | |
405 | label and we don't have to do anything else. */ | |
406 | ||
407 | insn = get_last_insn (); | |
6d7dc5b9 | 408 | while (NOTE_P (insn) |
409 | || (NONJUMP_INSN_P (insn) | |
75040552 | 410 | && (GET_CODE (PATTERN (insn)) == USE |
411 | || GET_CODE (PATTERN (insn)) == CLOBBER))) | |
412 | insn = PREV_INSN (insn); | |
413 | ||
875b3f3b | 414 | /* When a target threads its epilogue we might already have a |
57cd42ba | 415 | suitable return insn. If so put a label before it for the |
9cb2517e | 416 | function_return_label. */ |
6d7dc5b9 | 417 | if (BARRIER_P (insn) |
418 | && JUMP_P (PREV_INSN (insn)) | |
9cb2517e | 419 | && PATTERN (PREV_INSN (insn)) == kind) |
57cd42ba | 420 | { |
575a12f2 | 421 | rtx_insn *temp = PREV_INSN (PREV_INSN (insn)); |
422 | rtx_code_label *label = gen_label_rtx (); | |
9cb2517e | 423 | LABEL_NUSES (label) = 0; |
57cd42ba | 424 | |
9cb2517e | 425 | /* Put the label before any USE insns that may precede the RETURN |
426 | insn. */ | |
57cd42ba | 427 | while (GET_CODE (temp) == USE) |
428 | temp = PREV_INSN (temp); | |
429 | ||
9cb2517e | 430 | emit_label_after (label, temp); |
431 | *plabel = label; | |
57cd42ba | 432 | } |
433 | ||
6d7dc5b9 | 434 | else if (LABEL_P (insn)) |
575a12f2 | 435 | *plabel = as_a <rtx_code_label *> (insn); |
75040552 | 436 | else |
437 | { | |
575a12f2 | 438 | rtx_code_label *label = gen_label_rtx (); |
9cb2517e | 439 | LABEL_NUSES (label) = 0; |
f636b0a9 | 440 | /* If the basic block reorder pass moves the return insn to |
441 | some other place try to locate it again and put our | |
9cb2517e | 442 | function_return_label there. */ |
443 | while (insn && ! (JUMP_P (insn) && (PATTERN (insn) == kind))) | |
f636b0a9 | 444 | insn = PREV_INSN (insn); |
445 | if (insn) | |
75040552 | 446 | { |
f636b0a9 | 447 | insn = PREV_INSN (insn); |
448 | ||
9cb2517e | 449 | /* Put the label before any USE insns that may precede the |
f636b0a9 | 450 | RETURN insn. */ |
875b3f3b | 451 | while (GET_CODE (insn) == USE) |
f636b0a9 | 452 | insn = PREV_INSN (insn); |
453 | ||
9cb2517e | 454 | emit_label_after (label, insn); |
75040552 | 455 | } |
f636b0a9 | 456 | else |
457 | { | |
cf3a33c8 | 458 | if (targetm.have_epilogue () && ! targetm.have_return ()) |
9cb2517e | 459 | /* The RETURN insn has its delay slot filled so we cannot |
460 | emit the label just before it. Since we already have | |
461 | an epilogue and cannot emit a new RETURN, we cannot | |
462 | emit the label at all. */ | |
575a12f2 | 463 | return NULL; |
920d6e22 | 464 | |
875b3f3b | 465 | /* Otherwise, make a new label and emit a RETURN and BARRIER, |
f636b0a9 | 466 | if needed. */ |
9cb2517e | 467 | emit_label (label); |
5da5e283 | 468 | if (targetm.have_return ()) |
f636b0a9 | 469 | { |
470 | /* The return we make may have delay slots too. */ | |
5da5e283 | 471 | rtx_insn *pat = targetm.gen_return (); |
d3ffa7b4 | 472 | rtx_insn *insn = emit_jump_insn (pat); |
31a53363 | 473 | set_return_jump_label (insn); |
f636b0a9 | 474 | emit_barrier (); |
875b3f3b | 475 | if (num_delay_slots (insn) > 0) |
476 | obstack_ptr_grow (&unfilled_slots_obstack, insn); | |
f636b0a9 | 477 | } |
f636b0a9 | 478 | } |
9cb2517e | 479 | *plabel = label; |
75040552 | 480 | } |
481 | ||
482 | /* Show one additional use for this label so it won't go away until | |
483 | we are done. */ | |
9cb2517e | 484 | ++LABEL_NUSES (*plabel); |
75040552 | 485 | |
9cb2517e | 486 | return *plabel; |
75040552 | 487 | } |
488 | \f | |
489 | /* Put INSN and LIST together in a SEQUENCE rtx of LENGTH, and replace | |
490 | the pattern of INSN with the SEQUENCE. | |
491 | ||
575a12f2 | 492 | Returns the insn containing the SEQUENCE that replaces INSN. */ |
75040552 | 493 | |
575a12f2 | 494 | static rtx_insn * |
28cb74c5 | 495 | emit_delay_sequence (rtx_insn *insn, const vec<rtx_insn *> &list, int length) |
75040552 | 496 | { |
3398e91d | 497 | /* Allocate the rtvec to hold the insns and the SEQUENCE. */ |
75040552 | 498 | rtvec seqv = rtvec_alloc (length + 1); |
941522d6 | 499 | rtx seq = gen_rtx_SEQUENCE (VOIDmode, seqv); |
575a12f2 | 500 | rtx_insn *seq_insn = make_insn_raw (seq); |
cd11e340 | 501 | |
34f5b9ac | 502 | /* If DELAY_INSN has a location, use it for SEQ_INSN. If DELAY_INSN does |
503 | not have a location, but one of the delayed insns does, we pick up a | |
504 | location from there later. */ | |
505 | INSN_LOCATION (seq_insn) = INSN_LOCATION (insn); | |
75040552 | 506 | |
34f5b9ac | 507 | /* Unlink INSN from the insn chain, so that we can put it into |
508 | the SEQUENCE. Remember where we want to emit SEQUENCE in AFTER. */ | |
bf79ca12 | 509 | rtx_insn *after = PREV_INSN (insn); |
34f5b9ac | 510 | remove_insn (insn); |
4a57a2e8 | 511 | SET_NEXT_INSN (insn) = SET_PREV_INSN (insn) = NULL; |
75040552 | 512 | |
513 | /* Build our SEQUENCE and rebuild the insn chain. */ | |
34f5b9ac | 514 | start_sequence (); |
515 | XVECEXP (seq, 0, 0) = emit_insn (insn); | |
28cb74c5 | 516 | |
517 | unsigned int delay_insns = list.length (); | |
518 | gcc_assert (delay_insns == (unsigned int) length); | |
519 | for (unsigned int i = 0; i < delay_insns; i++) | |
75040552 | 520 | { |
28cb74c5 | 521 | rtx_insn *tem = list[i]; |
9b7d4a8f | 522 | rtx note, next; |
75040552 | 523 | |
524 | /* Show that this copy of the insn isn't deleted. */ | |
dd1286fb | 525 | tem->set_undeleted (); |
75040552 | 526 | |
34f5b9ac | 527 | /* Unlink insn from its original place, and re-emit it into |
528 | the sequence. */ | |
4a57a2e8 | 529 | SET_NEXT_INSN (tem) = SET_PREV_INSN (tem) = NULL; |
28cb74c5 | 530 | XVECEXP (seq, 0, i + 1) = emit_insn (tem); |
75040552 | 531 | |
ad2637b1 | 532 | /* SPARC assembler, for instance, emit warning when debug info is output |
533 | into the delay slot. */ | |
5169661d | 534 | if (INSN_LOCATION (tem) && !INSN_LOCATION (seq_insn)) |
535 | INSN_LOCATION (seq_insn) = INSN_LOCATION (tem); | |
536 | INSN_LOCATION (tem) = 0; | |
ad2637b1 | 537 | |
9b7d4a8f | 538 | for (note = REG_NOTES (tem); note; note = next) |
539 | { | |
540 | next = XEXP (note, 1); | |
541 | switch (REG_NOTE_KIND (note)) | |
542 | { | |
543 | case REG_DEAD: | |
544 | /* Remove any REG_DEAD notes because we can't rely on them now | |
545 | that the insn has been moved. */ | |
546 | remove_note (tem, note); | |
547 | break; | |
548 | ||
19d2fe05 | 549 | case REG_LABEL_OPERAND: |
550 | case REG_LABEL_TARGET: | |
9b7d4a8f | 551 | /* Keep the label reference count up to date. */ |
6d7dc5b9 | 552 | if (LABEL_P (XEXP (note, 0))) |
80563b56 | 553 | LABEL_NUSES (XEXP (note, 0)) ++; |
9b7d4a8f | 554 | break; |
555 | ||
556 | default: | |
557 | break; | |
558 | } | |
559 | } | |
75040552 | 560 | } |
34f5b9ac | 561 | end_sequence (); |
75040552 | 562 | |
34f5b9ac | 563 | /* Splice our SEQUENCE into the insn stream where INSN used to be. */ |
564 | add_insn_after (seq_insn, after, NULL); | |
565 | ||
75040552 | 566 | return seq_insn; |
567 | } | |
568 | ||
569 | /* Add INSN to DELAY_LIST and return the head of the new list. The list must | |
570 | be in the order in which the insns are to be executed. */ | |
571 | ||
28cb74c5 | 572 | static void |
573 | add_to_delay_list (rtx_insn *insn, vec<rtx_insn *> *delay_list) | |
75040552 | 574 | { |
28cb74c5 | 575 | /* If INSN has its block number recorded, clear it since we may |
004f4425 | 576 | be moving the insn to a new block. */ |
29bd1808 | 577 | clear_hashed_info_for_insn (insn); |
28cb74c5 | 578 | delay_list->safe_push (insn); |
875b3f3b | 579 | } |
75040552 | 580 | \f |
be2828ce | 581 | /* Delete INSN from the delay slot of the insn that it is in, which may |
582 | produce an insn with no delay slots. Return the new insn. */ | |
75040552 | 583 | |
575a12f2 | 584 | static rtx_insn * |
585 | delete_from_delay_slot (rtx_insn *insn) | |
75040552 | 586 | { |
575a12f2 | 587 | rtx_insn *trial, *seq_insn, *prev; |
588 | rtx_sequence *seq; | |
75040552 | 589 | int i; |
a85234d1 | 590 | int had_barrier = 0; |
75040552 | 591 | |
592 | /* We first must find the insn containing the SEQUENCE with INSN in its | |
593 | delay slot. Do this by finding an insn, TRIAL, where | |
594 | PREV_INSN (NEXT_INSN (TRIAL)) != TRIAL. */ | |
595 | ||
596 | for (trial = insn; | |
597 | PREV_INSN (NEXT_INSN (trial)) == trial; | |
598 | trial = NEXT_INSN (trial)) | |
599 | ; | |
600 | ||
601 | seq_insn = PREV_INSN (NEXT_INSN (trial)); | |
575a12f2 | 602 | seq = as_a <rtx_sequence *> (PATTERN (seq_insn)); |
75040552 | 603 | |
6d7dc5b9 | 604 | if (NEXT_INSN (seq_insn) && BARRIER_P (NEXT_INSN (seq_insn))) |
a85234d1 | 605 | had_barrier = 1; |
606 | ||
75040552 | 607 | /* Create a delay list consisting of all the insns other than the one |
608 | we are deleting (unless we were the only one). */ | |
28cb74c5 | 609 | auto_vec<rtx_insn *, 5> delay_list; |
575a12f2 | 610 | if (seq->len () > 2) |
611 | for (i = 1; i < seq->len (); i++) | |
612 | if (seq->insn (i) != insn) | |
28cb74c5 | 613 | add_to_delay_list (seq->insn (i), &delay_list); |
75040552 | 614 | |
615 | /* Delete the old SEQUENCE, re-emit the insn that used to have the delay | |
616 | list, and rebuild the delay list if non-empty. */ | |
617 | prev = PREV_INSN (seq_insn); | |
575a12f2 | 618 | trial = seq->insn (0); |
e4bf866d | 619 | delete_related_insns (seq_insn); |
3072d30e | 620 | add_insn_after (trial, prev, NULL); |
75040552 | 621 | |
a85234d1 | 622 | /* If there was a barrier after the old SEQUENCE, remit it. */ |
623 | if (had_barrier) | |
75040552 | 624 | emit_barrier_after (trial); |
625 | ||
626 | /* If there are any delay insns, remit them. Otherwise clear the | |
627 | annul flag. */ | |
28cb74c5 | 628 | if (!delay_list.is_empty ()) |
b44bc055 | 629 | trial = emit_delay_sequence (trial, delay_list, XVECLEN (seq, 0) - 2); |
7e66a69e | 630 | else if (JUMP_P (trial)) |
75040552 | 631 | INSN_ANNULLED_BRANCH_P (trial) = 0; |
632 | ||
633 | INSN_FROM_TARGET_P (insn) = 0; | |
634 | ||
635 | /* Show we need to fill this insn again. */ | |
636 | obstack_ptr_grow (&unfilled_slots_obstack, trial); | |
18418794 | 637 | |
638 | return trial; | |
75040552 | 639 | } |
640 | \f | |
641 | /* Delete INSN, a JUMP_INSN. If it is a conditional jump, we must track down | |
642 | the insn that sets CC0 for it and delete it too. */ | |
643 | ||
644 | static void | |
2cf26c51 | 645 | delete_scheduled_jump (rtx_insn *insn) |
75040552 | 646 | { |
647 | /* Delete the insn that sets cc0 for us. On machines without cc0, we could | |
648 | delete the insn that sets the condition code, but it is hard to find it. | |
649 | Since this case is rare anyway, don't bother trying; there would likely | |
650 | be other insns that became dead anyway, which we wouldn't know to | |
651 | delete. */ | |
652 | ||
ff900b8e | 653 | if (HAVE_cc0 && reg_mentioned_p (cc0_rtx, insn)) |
75040552 | 654 | { |
e5fdd564 | 655 | rtx note = find_reg_note (insn, REG_CC_SETTER, NULL_RTX); |
75040552 | 656 | |
657 | /* If a reg-note was found, it points to an insn to set CC0. This | |
658 | insn is in the delay list of some other insn. So delete it from | |
659 | the delay list it was in. */ | |
660 | if (note) | |
661 | { | |
e5fdd564 | 662 | if (! FIND_REG_INC_NOTE (XEXP (note, 0), NULL_RTX) |
75040552 | 663 | && sets_cc0_p (PATTERN (XEXP (note, 0))) == 1) |
575a12f2 | 664 | delete_from_delay_slot (as_a <rtx_insn *> (XEXP (note, 0))); |
75040552 | 665 | } |
666 | else | |
667 | { | |
668 | /* The insn setting CC0 is our previous insn, but it may be in | |
669 | a delay slot. It will be the last insn in the delay slot, if | |
670 | it is. */ | |
575a12f2 | 671 | rtx_insn *trial = previous_insn (insn); |
6d7dc5b9 | 672 | if (NOTE_P (trial)) |
75040552 | 673 | trial = prev_nonnote_insn (trial); |
674 | if (sets_cc0_p (PATTERN (trial)) != 1 | |
ed1e5d40 | 675 | || FIND_REG_INC_NOTE (trial, NULL_RTX)) |
75040552 | 676 | return; |
677 | if (PREV_INSN (NEXT_INSN (trial)) == trial) | |
e4bf866d | 678 | delete_related_insns (trial); |
75040552 | 679 | else |
680 | delete_from_delay_slot (trial); | |
681 | } | |
682 | } | |
75040552 | 683 | |
e4bf866d | 684 | delete_related_insns (insn); |
75040552 | 685 | } |
686 | \f | |
687 | /* Counters for delay-slot filling. */ | |
688 | ||
689 | #define NUM_REORG_FUNCTIONS 2 | |
690 | #define MAX_DELAY_HISTOGRAM 3 | |
691 | #define MAX_REORG_PASSES 2 | |
692 | ||
693 | static int num_insns_needing_delays[NUM_REORG_FUNCTIONS][MAX_REORG_PASSES]; | |
694 | ||
695 | static int num_filled_delays[NUM_REORG_FUNCTIONS][MAX_DELAY_HISTOGRAM+1][MAX_REORG_PASSES]; | |
696 | ||
697 | static int reorg_pass_number; | |
698 | ||
699 | static void | |
3ad4992f | 700 | note_delay_statistics (int slots_filled, int index) |
75040552 | 701 | { |
702 | num_insns_needing_delays[index][reorg_pass_number]++; | |
703 | if (slots_filled > MAX_DELAY_HISTOGRAM) | |
704 | slots_filled = MAX_DELAY_HISTOGRAM; | |
705 | num_filled_delays[index][slots_filled][reorg_pass_number]++; | |
706 | } | |
707 | \f | |
75040552 | 708 | /* Optimize the following cases: |
709 | ||
710 | 1. When a conditional branch skips over only one instruction, | |
711 | use an annulling branch and put that insn in the delay slot. | |
4bbea254 | 712 | Use either a branch that annuls when the condition if true or |
713 | invert the test with a branch that annuls when the condition is | |
75040552 | 714 | false. This saves insns, since otherwise we must copy an insn |
715 | from the L1 target. | |
716 | ||
717 | (orig) (skip) (otherwise) | |
718 | Bcc.n L1 Bcc',a L1 Bcc,a L1' | |
719 | insn insn insn2 | |
720 | L1: L1: L1: | |
721 | insn2 insn2 insn2 | |
722 | insn3 insn3 L1': | |
723 | insn3 | |
724 | ||
725 | 2. When a conditional branch skips over only one instruction, | |
726 | and after that, it unconditionally branches somewhere else, | |
727 | perform the similar optimization. This saves executing the | |
728 | second branch in the case where the inverted condition is true. | |
729 | ||
730 | Bcc.n L1 Bcc',a L2 | |
731 | insn insn | |
732 | L1: L1: | |
733 | Bra L2 Bra L2 | |
734 | ||
735 | INSN is a JUMP_INSN. | |
736 | ||
737 | This should be expanded to skip over N insns, where N is the number | |
738 | of delay slots required. */ | |
739 | ||
28cb74c5 | 740 | static void |
741 | optimize_skip (rtx_jump_insn *insn, vec<rtx_insn *> *delay_list) | |
75040552 | 742 | { |
575a12f2 | 743 | rtx_insn *trial = next_nonnote_insn (insn); |
4cd001d5 | 744 | rtx_insn *next_trial = next_active_insn (trial); |
45c67dee | 745 | int flags; |
746 | ||
747 | flags = get_jump_flags (insn, JUMP_LABEL (insn)); | |
75040552 | 748 | |
749 | if (trial == 0 | |
6d7dc5b9 | 750 | || !NONJUMP_INSN_P (trial) |
75040552 | 751 | || GET_CODE (PATTERN (trial)) == SEQUENCE |
752 | || recog_memoized (trial) < 0 | |
45c67dee | 753 | || (! eligible_for_annul_false (insn, 0, trial, flags) |
55427c62 | 754 | && ! eligible_for_annul_true (insn, 0, trial, flags)) |
755 | || can_throw_internal (trial)) | |
28cb74c5 | 756 | return; |
75040552 | 757 | |
758 | /* There are two cases where we are just executing one insn (we assume | |
759 | here that a branch requires only one insn; this should be generalized | |
760 | at some point): Where the branch goes around a single insn or where | |
761 | we have one insn followed by a branch to the same label we branch to. | |
762 | In both of these cases, inverting the jump and annulling the delay | |
763 | slot give the same effect in fewer insns. */ | |
d052c312 | 764 | if (next_trial == next_active_insn (JUMP_LABEL (insn)) |
75040552 | 765 | || (next_trial != 0 |
9cb2517e | 766 | && simplejump_or_return_p (next_trial) |
767 | && JUMP_LABEL (insn) == JUMP_LABEL (next_trial))) | |
75040552 | 768 | { |
45c67dee | 769 | if (eligible_for_annul_false (insn, 0, trial, flags)) |
75040552 | 770 | { |
f8cacb57 | 771 | if (invert_jump (insn, JUMP_LABEL (insn), 1)) |
75040552 | 772 | INSN_FROM_TARGET_P (trial) = 1; |
45c67dee | 773 | else if (! eligible_for_annul_true (insn, 0, trial, flags)) |
28cb74c5 | 774 | return; |
75040552 | 775 | } |
776 | ||
28cb74c5 | 777 | add_to_delay_list (trial, delay_list); |
75040552 | 778 | next_trial = next_active_insn (trial); |
779 | update_block (trial, trial); | |
e4bf866d | 780 | delete_related_insns (trial); |
75040552 | 781 | |
782 | /* Also, if we are targeting an unconditional | |
783 | branch, thread our jump to the target of that branch. Don't | |
784 | change this into a RETURN here, because it may not accept what | |
785 | we have in the delay slot. We'll fix this up later. */ | |
9cb2517e | 786 | if (next_trial && simplejump_or_return_p (next_trial)) |
75040552 | 787 | { |
920d6e22 | 788 | rtx target_label = JUMP_LABEL (next_trial); |
4115ac36 | 789 | if (ANY_RETURN_P (target_label)) |
9cb2517e | 790 | target_label = find_end_label (target_label); |
0742a0b2 | 791 | |
920d6e22 | 792 | if (target_label) |
793 | { | |
794 | /* Recompute the flags based on TARGET_LABEL since threading | |
795 | the jump to TARGET_LABEL may change the direction of the | |
796 | jump (which may change the circumstances in which the | |
797 | delay slot is nullified). */ | |
798 | flags = get_jump_flags (insn, target_label); | |
799 | if (eligible_for_annul_true (insn, 0, trial, flags)) | |
800 | reorg_redirect_jump (insn, target_label); | |
801 | } | |
75040552 | 802 | } |
803 | ||
804 | INSN_ANNULLED_BRANCH_P (insn) = 1; | |
805 | } | |
75040552 | 806 | } |
75040552 | 807 | \f |
45c67dee | 808 | /* Encode and return branch direction and prediction information for |
809 | INSN assuming it will jump to LABEL. | |
810 | ||
811 | Non conditional branches return no direction information and | |
812 | are predicted as very likely taken. */ | |
a92771b8 | 813 | |
45c67dee | 814 | static int |
93ee8dfb | 815 | get_jump_flags (const rtx_insn *insn, rtx label) |
45c67dee | 816 | { |
817 | int flags; | |
818 | ||
819 | /* get_jump_flags can be passed any insn with delay slots, these may | |
820 | be INSNs, CALL_INSNs, or JUMP_INSNs. Only JUMP_INSNs have branch | |
821 | direction information, and only if they are conditional jumps. | |
822 | ||
4115ac36 | 823 | If LABEL is a return, then there is no way to determine the branch |
45c67dee | 824 | direction. */ |
6d7dc5b9 | 825 | if (JUMP_P (insn) |
4fbe8fa7 | 826 | && (condjump_p (insn) || condjump_in_parallel_p (insn)) |
4115ac36 | 827 | && !ANY_RETURN_P (label) |
45c67dee | 828 | && INSN_UID (insn) <= max_uid |
9ac62cce | 829 | && INSN_UID (label) <= max_uid) |
875b3f3b | 830 | flags |
45c67dee | 831 | = (uid_to_ruid[INSN_UID (label)] > uid_to_ruid[INSN_UID (insn)]) |
832 | ? ATTR_FLAG_forward : ATTR_FLAG_backward; | |
833 | /* No valid direction information. */ | |
834 | else | |
835 | flags = 0; | |
875b3f3b | 836 | |
45c67dee | 837 | return flags; |
838 | } | |
839 | ||
75040552 | 840 | /* Return truth value of the statement that this branch |
841 | is mostly taken. If we think that the branch is extremely likely | |
842 | to be taken, we return 2. If the branch is slightly more likely to be | |
ea727872 | 843 | taken, return 1. If the branch is slightly less likely to be taken, |
9ddd9ef9 | 844 | return 0 and if the branch is highly unlikely to be taken, return -1. */ |
75040552 | 845 | |
846 | static int | |
9ddd9ef9 | 847 | mostly_true_jump (rtx jump_insn) |
75040552 | 848 | { |
0a29623e | 849 | /* If branch probabilities are available, then use that number since it |
850 | always gives a correct answer. */ | |
9ddd9ef9 | 851 | rtx note = find_reg_note (jump_insn, REG_BR_PROB, 0); |
124d766d | 852 | if (note) |
0a29623e | 853 | { |
9eb946de | 854 | int prob = XINT (note, 0); |
124d766d | 855 | |
856 | if (prob >= REG_BR_PROB_BASE * 9 / 10) | |
875b3f3b | 857 | return 2; |
124d766d | 858 | else if (prob >= REG_BR_PROB_BASE / 2) |
875b3f3b | 859 | return 1; |
124d766d | 860 | else if (prob >= REG_BR_PROB_BASE / 10) |
875b3f3b | 861 | return 0; |
124d766d | 862 | else |
875b3f3b | 863 | return -1; |
0a29623e | 864 | } |
865 | ||
9ddd9ef9 | 866 | /* If there is no note, assume branches are not taken. |
867 | This should be rare. */ | |
75040552 | 868 | return 0; |
75040552 | 869 | } |
870 | ||
871 | /* Return the condition under which INSN will branch to TARGET. If TARGET | |
872 | is zero, return the condition under which INSN will return. If INSN is | |
873 | an unconditional branch, return const_true_rtx. If INSN isn't a simple | |
874 | type of jump, or it doesn't go to TARGET, return 0. */ | |
875 | ||
876 | static rtx | |
93ee8dfb | 877 | get_branch_condition (const rtx_insn *insn, rtx target) |
75040552 | 878 | { |
879 | rtx pat = PATTERN (insn); | |
880 | rtx src; | |
875b3f3b | 881 | |
4fbe8fa7 | 882 | if (condjump_in_parallel_p (insn)) |
883 | pat = XVECEXP (pat, 0, 0); | |
884 | ||
965df672 | 885 | if (ANY_RETURN_P (pat) && pat == target) |
886 | return const_true_rtx; | |
75040552 | 887 | |
4115ac36 | 888 | if (GET_CODE (pat) != SET || SET_DEST (pat) != pc_rtx) |
75040552 | 889 | return 0; |
890 | ||
891 | src = SET_SRC (pat); | |
b49f2e4b | 892 | if (GET_CODE (src) == LABEL_REF && LABEL_REF_LABEL (src) == target) |
75040552 | 893 | return const_true_rtx; |
894 | ||
895 | else if (GET_CODE (src) == IF_THEN_ELSE | |
7e66a69e | 896 | && XEXP (src, 2) == pc_rtx |
965df672 | 897 | && ((GET_CODE (XEXP (src, 1)) == LABEL_REF |
b49f2e4b | 898 | && LABEL_REF_LABEL (XEXP (src, 1)) == target) |
965df672 | 899 | || (ANY_RETURN_P (XEXP (src, 1)) && XEXP (src, 1) == target))) |
75040552 | 900 | return XEXP (src, 0); |
901 | ||
902 | else if (GET_CODE (src) == IF_THEN_ELSE | |
7e66a69e | 903 | && XEXP (src, 1) == pc_rtx |
965df672 | 904 | && ((GET_CODE (XEXP (src, 2)) == LABEL_REF |
b49f2e4b | 905 | && LABEL_REF_LABEL (XEXP (src, 2)) == target) |
965df672 | 906 | || (ANY_RETURN_P (XEXP (src, 2)) && XEXP (src, 2) == target))) |
045a0eef | 907 | { |
908 | enum rtx_code rev; | |
909 | rev = reversed_comparison_code (XEXP (src, 0), insn); | |
910 | if (rev != UNKNOWN) | |
911 | return gen_rtx_fmt_ee (rev, GET_MODE (XEXP (src, 0)), | |
912 | XEXP (XEXP (src, 0), 0), | |
913 | XEXP (XEXP (src, 0), 1)); | |
914 | } | |
607e8d51 | 915 | |
916 | return 0; | |
75040552 | 917 | } |
918 | ||
7fd957fe | 919 | /* Return nonzero if CONDITION is more strict than the condition of |
75040552 | 920 | INSN, i.e., if INSN will always branch if CONDITION is true. */ |
921 | ||
922 | static int | |
93ee8dfb | 923 | condition_dominates_p (rtx condition, const rtx_insn *insn) |
75040552 | 924 | { |
925 | rtx other_condition = get_branch_condition (insn, JUMP_LABEL (insn)); | |
926 | enum rtx_code code = GET_CODE (condition); | |
927 | enum rtx_code other_code; | |
928 | ||
929 | if (rtx_equal_p (condition, other_condition) | |
930 | || other_condition == const_true_rtx) | |
931 | return 1; | |
932 | ||
933 | else if (condition == const_true_rtx || other_condition == 0) | |
934 | return 0; | |
935 | ||
936 | other_code = GET_CODE (other_condition); | |
937 | if (GET_RTX_LENGTH (code) != 2 || GET_RTX_LENGTH (other_code) != 2 | |
938 | || ! rtx_equal_p (XEXP (condition, 0), XEXP (other_condition, 0)) | |
939 | || ! rtx_equal_p (XEXP (condition, 1), XEXP (other_condition, 1))) | |
940 | return 0; | |
941 | ||
942 | return comparison_dominates_p (code, other_code); | |
943 | } | |
1ee06916 | 944 | |
7fd957fe | 945 | /* Return nonzero if redirecting JUMP to NEWLABEL does not invalidate |
1ee06916 | 946 | any insns already in the delay slot of JUMP. */ |
947 | ||
948 | static int | |
91a55c11 | 949 | redirect_with_delay_slots_safe_p (rtx_insn *jump, rtx newlabel, rtx seq) |
1ee06916 | 950 | { |
b44bc055 | 951 | int flags, i; |
91a55c11 | 952 | rtx_sequence *pat = as_a <rtx_sequence *> (PATTERN (seq)); |
1ee06916 | 953 | |
954 | /* Make sure all the delay slots of this jump would still | |
955 | be valid after threading the jump. If they are still | |
7fd957fe | 956 | valid, then return nonzero. */ |
1ee06916 | 957 | |
958 | flags = get_jump_flags (jump, newlabel); | |
91a55c11 | 959 | for (i = 1; i < pat->len (); i++) |
1ee06916 | 960 | if (! ( |
9d463a01 | 961 | #if ANNUL_IFFALSE_SLOTS |
1ee06916 | 962 | (INSN_ANNULLED_BRANCH_P (jump) |
91a55c11 | 963 | && INSN_FROM_TARGET_P (pat->insn (i))) |
964 | ? eligible_for_annul_false (jump, i - 1, pat->insn (i), flags) : | |
1ee06916 | 965 | #endif |
9d463a01 | 966 | #if ANNUL_IFTRUE_SLOTS |
1ee06916 | 967 | (INSN_ANNULLED_BRANCH_P (jump) |
968 | && ! INSN_FROM_TARGET_P (XVECEXP (pat, 0, i))) | |
91a55c11 | 969 | ? eligible_for_annul_true (jump, i - 1, pat->insn (i), flags) : |
1ee06916 | 970 | #endif |
91a55c11 | 971 | eligible_for_delay (jump, i - 1, pat->insn (i), flags))) |
1ee06916 | 972 | break; |
973 | ||
91a55c11 | 974 | return (i == pat->len ()); |
1ee06916 | 975 | } |
976 | ||
7fd957fe | 977 | /* Return nonzero if redirecting JUMP to NEWLABEL does not invalidate |
c80ad736 | 978 | any insns we wish to place in the delay slot of JUMP. */ |
979 | ||
980 | static int | |
91a55c11 | 981 | redirect_with_delay_list_safe_p (rtx_insn *jump, rtx newlabel, |
28cb74c5 | 982 | const vec<rtx_insn *> &delay_list) |
c80ad736 | 983 | { |
c80ad736 | 984 | /* Make sure all the insns in DELAY_LIST would still be |
985 | valid after threading the jump. If they are still | |
7fd957fe | 986 | valid, then return nonzero. */ |
c80ad736 | 987 | |
28cb74c5 | 988 | int flags = get_jump_flags (jump, newlabel); |
989 | unsigned int delay_insns = delay_list.length (); | |
990 | unsigned int i = 0; | |
991 | for (; i < delay_insns; i++) | |
c80ad736 | 992 | if (! ( |
9d463a01 | 993 | #if ANNUL_IFFALSE_SLOTS |
c80ad736 | 994 | (INSN_ANNULLED_BRANCH_P (jump) |
28cb74c5 | 995 | && INSN_FROM_TARGET_P (delay_list[i])) |
996 | ? eligible_for_annul_false (jump, i, delay_list[i], flags) : | |
c80ad736 | 997 | #endif |
9d463a01 | 998 | #if ANNUL_IFTRUE_SLOTS |
c80ad736 | 999 | (INSN_ANNULLED_BRANCH_P (jump) |
28cb74c5 | 1000 | && ! INSN_FROM_TARGET_P (delay_list[i])) |
1001 | ? eligible_for_annul_true (jump, i, delay_list[i], flags) : | |
c80ad736 | 1002 | #endif |
28cb74c5 | 1003 | eligible_for_delay (jump, i, delay_list[i], flags))) |
c80ad736 | 1004 | break; |
1005 | ||
28cb74c5 | 1006 | return i == delay_insns; |
c80ad736 | 1007 | } |
1008 | ||
18418794 | 1009 | /* DELAY_LIST is a list of insns that have already been placed into delay |
1010 | slots. See if all of them have the same annulling status as ANNUL_TRUE_P. | |
1011 | If not, return 0; otherwise return 1. */ | |
1012 | ||
1013 | static int | |
28cb74c5 | 1014 | check_annul_list_true_false (int annul_true_p, |
1015 | const vec<rtx_insn *> &delay_list) | |
18418794 | 1016 | { |
28cb74c5 | 1017 | rtx_insn *trial; |
1018 | unsigned int i; | |
1019 | FOR_EACH_VEC_ELT (delay_list, i, trial) | |
1020 | if ((annul_true_p && INSN_FROM_TARGET_P (trial)) | |
1021 | || (!annul_true_p && !INSN_FROM_TARGET_P (trial))) | |
1022 | return 0; | |
be2828ce | 1023 | |
18418794 | 1024 | return 1; |
1025 | } | |
75040552 | 1026 | \f |
1027 | /* INSN branches to an insn whose pattern SEQ is a SEQUENCE. Given that | |
1028 | the condition tested by INSN is CONDITION and the resources shown in | |
1029 | OTHER_NEEDED are needed after INSN, see whether INSN can take all the insns | |
1030 | from SEQ's delay list, in addition to whatever insns it may execute | |
1031 | (in DELAY_LIST). SETS and NEEDED are denote resources already set and | |
1032 | needed while searching for delay slot insns. Return the concatenated | |
1033 | delay list if possible, otherwise, return 0. | |
1034 | ||
1035 | SLOTS_TO_FILL is the total number of slots required by INSN, and | |
1036 | PSLOTS_FILLED points to the number filled so far (also the number of | |
1037 | insns in DELAY_LIST). It is updated with the number that have been | |
1038 | filled from the SEQUENCE, if any. | |
1039 | ||
7fd957fe | 1040 | PANNUL_P points to a nonzero value if we already know that we need |
75040552 | 1041 | to annul INSN. If this routine determines that annulling is needed, |
7fd957fe | 1042 | it may set that value nonzero. |
75040552 | 1043 | |
1044 | PNEW_THREAD points to a location that is to receive the place at which | |
1045 | execution should continue. */ | |
1046 | ||
28cb74c5 | 1047 | static void |
91a55c11 | 1048 | steal_delay_list_from_target (rtx_insn *insn, rtx condition, rtx_sequence *seq, |
28cb74c5 | 1049 | vec<rtx_insn *> *delay_list, resources *sets, |
3ad4992f | 1050 | struct resources *needed, |
1051 | struct resources *other_needed, | |
1052 | int slots_to_fill, int *pslots_filled, | |
c2c03a95 | 1053 | int *pannul_p, rtx *pnew_thread) |
75040552 | 1054 | { |
75040552 | 1055 | int slots_remaining = slots_to_fill - *pslots_filled; |
1056 | int total_slots_filled = *pslots_filled; | |
28cb74c5 | 1057 | auto_vec<rtx_insn *, 5> new_delay_list; |
75040552 | 1058 | int must_annul = *pannul_p; |
cbfa4b86 | 1059 | int used_annul = 0; |
be2828ce | 1060 | int i; |
86236ca9 | 1061 | struct resources cc_set; |
3d59aca0 | 1062 | bool *redundant; |
75040552 | 1063 | |
1064 | /* We can't do anything if there are more delay slots in SEQ than we | |
1065 | can handle, or if we don't know that it will be a taken branch. | |
75040552 | 1066 | We know that it will be a taken branch if it is either an unconditional |
fb1e86f2 | 1067 | branch or a conditional branch with a stricter branch condition. |
1068 | ||
1069 | Also, exit if the branch has more than one set, since then it is computing | |
1070 | other results that can't be ignored, e.g. the HPPA mov&branch instruction. | |
1071 | ??? It may be possible to move other sets into INSN in addition to | |
86236ca9 | 1072 | moving the instructions in the delay slots. |
1073 | ||
1074 | We can not steal the delay list if one of the instructions in the | |
875b3f3b | 1075 | current delay_list modifies the condition codes and the jump in the |
86236ca9 | 1076 | sequence is a conditional jump. We can not do this because we can |
1077 | not change the direction of the jump because the condition codes | |
875b3f3b | 1078 | will effect the direction of the jump in the sequence. */ |
86236ca9 | 1079 | |
1080 | CLEAR_RESOURCE (&cc_set); | |
86236ca9 | 1081 | |
28cb74c5 | 1082 | rtx_insn *trial; |
1083 | FOR_EACH_VEC_ELT (*delay_list, i, trial) | |
1084 | { | |
d2137327 | 1085 | mark_set_resources (trial, &cc_set, 0, MARK_SRC_DEST_CALL); |
575a12f2 | 1086 | if (insn_references_resource_p (seq->insn (0), &cc_set, false)) |
28cb74c5 | 1087 | return; |
86236ca9 | 1088 | } |
75040552 | 1089 | |
1090 | if (XVECLEN (seq, 0) - 1 > slots_remaining | |
575a12f2 | 1091 | || ! condition_dominates_p (condition, seq->insn (0)) |
1092 | || ! single_set (seq->insn (0))) | |
28cb74c5 | 1093 | return; |
75040552 | 1094 | |
e95ebfe0 | 1095 | /* On some targets, branches with delay slots can have a limited |
1096 | displacement. Give the back end a chance to tell us we can't do | |
1097 | this. */ | |
7ab0488c | 1098 | if (! targetm.can_follow_jump (insn, seq->insn (0))) |
28cb74c5 | 1099 | return; |
e95ebfe0 | 1100 | |
3d59aca0 | 1101 | redundant = XALLOCAVEC (bool, XVECLEN (seq, 0)); |
575a12f2 | 1102 | for (i = 1; i < seq->len (); i++) |
75040552 | 1103 | { |
575a12f2 | 1104 | rtx_insn *trial = seq->insn (i); |
45c67dee | 1105 | int flags; |
75040552 | 1106 | |
10a15ee4 | 1107 | if (insn_references_resource_p (trial, sets, false) |
1108 | || insn_sets_resource_p (trial, needed, false) | |
1109 | || insn_sets_resource_p (trial, sets, false) | |
75040552 | 1110 | /* If TRIAL sets CC0, we can't copy it, so we can't steal this |
1111 | delay list. */ | |
ff900b8e | 1112 | || (HAVE_cc0 && find_reg_note (trial, REG_CC_USER, NULL_RTX)) |
75040552 | 1113 | /* If TRIAL is from the fallthrough code of an annulled branch insn |
1114 | in SEQ, we cannot use it. */ | |
575a12f2 | 1115 | || (INSN_ANNULLED_BRANCH_P (seq->insn (0)) |
75040552 | 1116 | && ! INSN_FROM_TARGET_P (trial))) |
28cb74c5 | 1117 | return; |
75040552 | 1118 | |
1119 | /* If this insn was already done (usually in a previous delay slot), | |
1120 | pretend we put it in our delay slot. */ | |
3d59aca0 | 1121 | redundant[i] = redundant_insn (trial, insn, new_delay_list); |
1122 | if (redundant[i]) | |
75040552 | 1123 | continue; |
1124 | ||
45c67dee | 1125 | /* We will end up re-vectoring this branch, so compute flags |
1126 | based on jumping to the new label. */ | |
575a12f2 | 1127 | flags = get_jump_flags (insn, JUMP_LABEL (seq->insn (0))); |
45c67dee | 1128 | |
75040552 | 1129 | if (! must_annul |
1130 | && ((condition == const_true_rtx | |
10a15ee4 | 1131 | || (! insn_sets_resource_p (trial, other_needed, false) |
1aecae7f | 1132 | && ! may_trap_or_fault_p (PATTERN (trial))))) |
45c67dee | 1133 | ? eligible_for_delay (insn, total_slots_filled, trial, flags) |
28cb74c5 | 1134 | : (must_annul || (delay_list->is_empty () && new_delay_list.is_empty ())) |
18418794 | 1135 | && (must_annul = 1, |
28cb74c5 | 1136 | check_annul_list_true_false (0, *delay_list) |
18418794 | 1137 | && check_annul_list_true_false (0, new_delay_list) |
1138 | && eligible_for_annul_false (insn, total_slots_filled, | |
1139 | trial, flags))) | |
75040552 | 1140 | { |
18418794 | 1141 | if (must_annul) |
1142 | used_annul = 1; | |
575a12f2 | 1143 | rtx_insn *temp = copy_delay_slot_insn (trial); |
75040552 | 1144 | INSN_FROM_TARGET_P (temp) = 1; |
28cb74c5 | 1145 | add_to_delay_list (temp, &new_delay_list); |
75040552 | 1146 | total_slots_filled++; |
1147 | ||
1148 | if (--slots_remaining == 0) | |
1149 | break; | |
1150 | } | |
1151 | else | |
28cb74c5 | 1152 | return; |
75040552 | 1153 | } |
1154 | ||
3d59aca0 | 1155 | /* Record the effect of the instructions that were redundant and which |
1156 | we therefore decided not to copy. */ | |
2cf26c51 | 1157 | for (i = 1; i < seq->len (); i++) |
3d59aca0 | 1158 | if (redundant[i]) |
2cf26c51 | 1159 | update_block (seq->insn (i), insn); |
3d59aca0 | 1160 | |
75040552 | 1161 | /* Show the place to which we will be branching. */ |
c2c03a95 | 1162 | *pnew_thread = first_active_target_insn (JUMP_LABEL (seq->insn (0))); |
75040552 | 1163 | |
1164 | /* Add any new insns to the delay list and update the count of the | |
1165 | number of slots filled. */ | |
1166 | *pslots_filled = total_slots_filled; | |
18418794 | 1167 | if (used_annul) |
1168 | *pannul_p = 1; | |
75040552 | 1169 | |
28cb74c5 | 1170 | rtx_insn *temp; |
1171 | FOR_EACH_VEC_ELT (new_delay_list, i, temp) | |
1172 | add_to_delay_list (temp, delay_list); | |
75040552 | 1173 | } |
1174 | \f | |
875b3f3b | 1175 | /* Similar to steal_delay_list_from_target except that SEQ is on the |
75040552 | 1176 | fallthrough path of INSN. Here we only do something if the delay insn |
1177 | of SEQ is an unconditional branch. In that case we steal its delay slot | |
1178 | for INSN since unconditional branches are much easier to fill. */ | |
1179 | ||
28cb74c5 | 1180 | static void |
91a55c11 | 1181 | steal_delay_list_from_fallthrough (rtx_insn *insn, rtx condition, |
1182 | rtx_sequence *seq, | |
28cb74c5 | 1183 | vec<rtx_insn *> *delay_list, |
575a12f2 | 1184 | struct resources *sets, |
3ad4992f | 1185 | struct resources *needed, |
1186 | struct resources *other_needed, | |
1187 | int slots_to_fill, int *pslots_filled, | |
1188 | int *pannul_p) | |
75040552 | 1189 | { |
1190 | int i; | |
45c67dee | 1191 | int flags; |
18418794 | 1192 | int must_annul = *pannul_p; |
1193 | int used_annul = 0; | |
45c67dee | 1194 | |
1195 | flags = get_jump_flags (insn, JUMP_LABEL (insn)); | |
75040552 | 1196 | |
1197 | /* We can't do anything if SEQ's delay insn isn't an | |
1198 | unconditional branch. */ | |
1199 | ||
575a12f2 | 1200 | if (! simplejump_or_return_p (seq->insn (0))) |
28cb74c5 | 1201 | return; |
75040552 | 1202 | |
575a12f2 | 1203 | for (i = 1; i < seq->len (); i++) |
75040552 | 1204 | { |
575a12f2 | 1205 | rtx_insn *trial = seq->insn (i); |
75040552 | 1206 | |
1207 | /* If TRIAL sets CC0, stealing it will move it too far from the use | |
1208 | of CC0. */ | |
10a15ee4 | 1209 | if (insn_references_resource_p (trial, sets, false) |
1210 | || insn_sets_resource_p (trial, needed, false) | |
1211 | || insn_sets_resource_p (trial, sets, false) | |
ff900b8e | 1212 | || (HAVE_cc0 && sets_cc0_p (PATTERN (trial)))) |
75040552 | 1213 | |
1214 | break; | |
1215 | ||
1216 | /* If this insn was already done, we don't need it. */ | |
28cb74c5 | 1217 | if (redundant_insn (trial, insn, *delay_list)) |
75040552 | 1218 | { |
3d59aca0 | 1219 | update_block (trial, insn); |
75040552 | 1220 | delete_from_delay_slot (trial); |
1221 | continue; | |
1222 | } | |
1223 | ||
18418794 | 1224 | if (! must_annul |
75040552 | 1225 | && ((condition == const_true_rtx |
10a15ee4 | 1226 | || (! insn_sets_resource_p (trial, other_needed, false) |
1aecae7f | 1227 | && ! may_trap_or_fault_p (PATTERN (trial))))) |
45c67dee | 1228 | ? eligible_for_delay (insn, *pslots_filled, trial, flags) |
28cb74c5 | 1229 | : (must_annul || delay_list->is_empty ()) && (must_annul = 1, |
1230 | check_annul_list_true_false (1, *delay_list) | |
18418794 | 1231 | && eligible_for_annul_true (insn, *pslots_filled, trial, flags))) |
75040552 | 1232 | { |
18418794 | 1233 | if (must_annul) |
1234 | used_annul = 1; | |
75040552 | 1235 | delete_from_delay_slot (trial); |
28cb74c5 | 1236 | add_to_delay_list (trial, delay_list); |
75040552 | 1237 | |
1238 | if (++(*pslots_filled) == slots_to_fill) | |
1239 | break; | |
1240 | } | |
1241 | else | |
1242 | break; | |
1243 | } | |
1244 | ||
18418794 | 1245 | if (used_annul) |
1246 | *pannul_p = 1; | |
75040552 | 1247 | } |
1248 | \f | |
1249 | /* Try merging insns starting at THREAD which match exactly the insns in | |
1250 | INSN's delay list. | |
1251 | ||
1252 | If all insns were matched and the insn was previously annulling, the | |
1253 | annul bit will be cleared. | |
1254 | ||
1255 | For each insn that is merged, if the branch is or will be non-annulling, | |
1256 | we delete the merged insn. */ | |
1257 | ||
1258 | static void | |
f6860e7f | 1259 | try_merge_delay_insns (rtx_insn *insn, rtx_insn *thread) |
75040552 | 1260 | { |
91a55c11 | 1261 | rtx_insn *trial, *next_trial; |
1262 | rtx_insn *delay_insn = as_a <rtx_insn *> (XVECEXP (PATTERN (insn), 0, 0)); | |
7e66a69e | 1263 | int annul_p = JUMP_P (delay_insn) && INSN_ANNULLED_BRANCH_P (delay_insn); |
75040552 | 1264 | int slot_number = 1; |
1265 | int num_slots = XVECLEN (PATTERN (insn), 0); | |
1266 | rtx next_to_match = XVECEXP (PATTERN (insn), 0, slot_number); | |
d147c6d7 | 1267 | struct resources set, needed, modified; |
575a12f2 | 1268 | rtx_insn_list *merged_insns = 0; |
d147c6d7 | 1269 | int i, j; |
45c67dee | 1270 | int flags; |
1271 | ||
ee41588e | 1272 | flags = get_jump_flags (delay_insn, JUMP_LABEL (delay_insn)); |
75040552 | 1273 | |
1274 | CLEAR_RESOURCE (&needed); | |
1275 | CLEAR_RESOURCE (&set); | |
1276 | ||
1277 | /* If this is not an annulling branch, take into account anything needed in | |
18418794 | 1278 | INSN's delay slot. This prevents two increments from being incorrectly |
75040552 | 1279 | folded into one. If we are annulling, this would be the correct |
1280 | thing to do. (The alternative, looking at things set in NEXT_TO_MATCH | |
1281 | will essentially disable this optimization. This method is somewhat of | |
1282 | a kludge, but I don't see a better way.) */ | |
1283 | if (! annul_p) | |
875b3f3b | 1284 | for (i = 1 ; i < num_slots; i++) |
18418794 | 1285 | if (XVECEXP (PATTERN (insn), 0, i)) |
10a15ee4 | 1286 | mark_referenced_resources (XVECEXP (PATTERN (insn), 0, i), &needed, |
1287 | true); | |
75040552 | 1288 | |
1289 | for (trial = thread; !stop_search_p (trial, 1); trial = next_trial) | |
1290 | { | |
1291 | rtx pat = PATTERN (trial); | |
66d536cf | 1292 | rtx oldtrial = trial; |
75040552 | 1293 | |
1294 | next_trial = next_nonnote_insn (trial); | |
1295 | ||
1296 | /* TRIAL must be a CALL_INSN or INSN. Skip USE and CLOBBER. */ | |
6d7dc5b9 | 1297 | if (NONJUMP_INSN_P (trial) |
75040552 | 1298 | && (GET_CODE (pat) == USE || GET_CODE (pat) == CLOBBER)) |
1299 | continue; | |
1300 | ||
1301 | if (GET_CODE (next_to_match) == GET_CODE (trial) | |
75040552 | 1302 | /* We can't share an insn that sets cc0. */ |
693c9f42 | 1303 | && (!HAVE_cc0 || ! sets_cc0_p (pat)) |
10a15ee4 | 1304 | && ! insn_references_resource_p (trial, &set, true) |
1305 | && ! insn_sets_resource_p (trial, &set, true) | |
1306 | && ! insn_sets_resource_p (trial, &needed, true) | |
75040552 | 1307 | && (trial = try_split (pat, trial, 0)) != 0 |
5eeb06bc | 1308 | /* Update next_trial, in case try_split succeeded. */ |
1309 | && (next_trial = next_nonnote_insn (trial)) | |
66d536cf | 1310 | /* Likewise THREAD. */ |
1311 | && (thread = oldtrial == thread ? trial : thread) | |
75040552 | 1312 | && rtx_equal_p (PATTERN (next_to_match), PATTERN (trial)) |
1313 | /* Have to test this condition if annul condition is different | |
1314 | from (and less restrictive than) non-annulling one. */ | |
45c67dee | 1315 | && eligible_for_delay (delay_insn, slot_number - 1, trial, flags)) |
75040552 | 1316 | { |
75040552 | 1317 | |
1318 | if (! annul_p) | |
1319 | { | |
3d5c2032 | 1320 | update_block (trial, thread); |
e884b3ed | 1321 | if (trial == thread) |
1322 | thread = next_active_insn (thread); | |
1323 | ||
e4bf866d | 1324 | delete_related_insns (trial); |
75040552 | 1325 | INSN_FROM_TARGET_P (next_to_match) = 0; |
1326 | } | |
1327 | else | |
941522d6 | 1328 | merged_insns = gen_rtx_INSN_LIST (VOIDmode, trial, merged_insns); |
75040552 | 1329 | |
1330 | if (++slot_number == num_slots) | |
1331 | break; | |
1332 | ||
1333 | next_to_match = XVECEXP (PATTERN (insn), 0, slot_number); | |
75040552 | 1334 | } |
1335 | ||
d2137327 | 1336 | mark_set_resources (trial, &set, 0, MARK_SRC_DEST_CALL); |
10a15ee4 | 1337 | mark_referenced_resources (trial, &needed, true); |
75040552 | 1338 | } |
1339 | ||
1340 | /* See if we stopped on a filled insn. If we did, try to see if its | |
1341 | delay slots match. */ | |
1342 | if (slot_number != num_slots | |
6d7dc5b9 | 1343 | && trial && NONJUMP_INSN_P (trial) |
75040552 | 1344 | && GET_CODE (PATTERN (trial)) == SEQUENCE |
7e66a69e | 1345 | && !(JUMP_P (XVECEXP (PATTERN (trial), 0, 0)) |
1346 | && INSN_ANNULLED_BRANCH_P (XVECEXP (PATTERN (trial), 0, 0)))) | |
75040552 | 1347 | { |
575a12f2 | 1348 | rtx_sequence *pat = as_a <rtx_sequence *> (PATTERN (trial)); |
0daa40e5 | 1349 | rtx filled_insn = XVECEXP (pat, 0, 0); |
1350 | ||
1351 | /* Account for resources set/needed by the filled insn. */ | |
d2137327 | 1352 | mark_set_resources (filled_insn, &set, 0, MARK_SRC_DEST_CALL); |
10a15ee4 | 1353 | mark_referenced_resources (filled_insn, &needed, true); |
75040552 | 1354 | |
575a12f2 | 1355 | for (i = 1; i < pat->len (); i++) |
75040552 | 1356 | { |
575a12f2 | 1357 | rtx_insn *dtrial = pat->insn (i); |
75040552 | 1358 | |
d147c6d7 | 1359 | CLEAR_RESOURCE (&modified); |
47ae02b7 | 1360 | /* Account for resources set by the insn following NEXT_TO_MATCH |
d147c6d7 | 1361 | inside INSN's delay list. */ |
1362 | for (j = 1; slot_number + j < num_slots; j++) | |
1363 | mark_set_resources (XVECEXP (PATTERN (insn), 0, slot_number + j), | |
1364 | &modified, 0, MARK_SRC_DEST_CALL); | |
47ae02b7 | 1365 | /* Account for resources set by the insn before DTRIAL and inside |
d147c6d7 | 1366 | TRIAL's delay list. */ |
1367 | for (j = 1; j < i; j++) | |
1368 | mark_set_resources (XVECEXP (pat, 0, j), | |
1369 | &modified, 0, MARK_SRC_DEST_CALL); | |
10a15ee4 | 1370 | if (! insn_references_resource_p (dtrial, &set, true) |
1371 | && ! insn_sets_resource_p (dtrial, &set, true) | |
1372 | && ! insn_sets_resource_p (dtrial, &needed, true) | |
693c9f42 | 1373 | && (!HAVE_cc0 || ! sets_cc0_p (PATTERN (dtrial))) |
75040552 | 1374 | && rtx_equal_p (PATTERN (next_to_match), PATTERN (dtrial)) |
d147c6d7 | 1375 | /* Check that DTRIAL and NEXT_TO_MATCH does not reference a |
1376 | resource modified between them (only dtrial is checked because | |
1377 | next_to_match and dtrial shall to be equal in order to hit | |
1378 | this line) */ | |
1379 | && ! insn_references_resource_p (dtrial, &modified, true) | |
45c67dee | 1380 | && eligible_for_delay (delay_insn, slot_number - 1, dtrial, flags)) |
75040552 | 1381 | { |
1382 | if (! annul_p) | |
1383 | { | |
575a12f2 | 1384 | rtx_insn *new_rtx; |
18418794 | 1385 | |
3d5c2032 | 1386 | update_block (dtrial, thread); |
8deb3959 | 1387 | new_rtx = delete_from_delay_slot (dtrial); |
dd1286fb | 1388 | if (thread->deleted ()) |
8deb3959 | 1389 | thread = new_rtx; |
75040552 | 1390 | INSN_FROM_TARGET_P (next_to_match) = 0; |
1391 | } | |
1392 | else | |
941522d6 | 1393 | merged_insns = gen_rtx_INSN_LIST (SImode, dtrial, |
1394 | merged_insns); | |
75040552 | 1395 | |
1396 | if (++slot_number == num_slots) | |
1397 | break; | |
1398 | ||
1399 | next_to_match = XVECEXP (PATTERN (insn), 0, slot_number); | |
1400 | } | |
18418794 | 1401 | else |
1402 | { | |
cbfa4b86 | 1403 | /* Keep track of the set/referenced resources for the delay |
1404 | slots of any trial insns we encounter. */ | |
875b3f3b | 1405 | mark_set_resources (dtrial, &set, 0, MARK_SRC_DEST_CALL); |
10a15ee4 | 1406 | mark_referenced_resources (dtrial, &needed, true); |
18418794 | 1407 | } |
75040552 | 1408 | } |
1409 | } | |
1410 | ||
1411 | /* If all insns in the delay slot have been matched and we were previously | |
1412 | annulling the branch, we need not any more. In that case delete all the | |
3398e91d | 1413 | merged insns. Also clear the INSN_FROM_TARGET_P bit of each insn in |
75040552 | 1414 | the delay list so that we know that it isn't only being used at the |
1415 | target. */ | |
fd665ae5 | 1416 | if (slot_number == num_slots && annul_p) |
75040552 | 1417 | { |
575a12f2 | 1418 | for (; merged_insns; merged_insns = merged_insns->next ()) |
75040552 | 1419 | { |
1420 | if (GET_MODE (merged_insns) == SImode) | |
1421 | { | |
575a12f2 | 1422 | rtx_insn *new_rtx; |
18418794 | 1423 | |
2cf26c51 | 1424 | update_block (merged_insns->insn (), thread); |
575a12f2 | 1425 | new_rtx = delete_from_delay_slot (merged_insns->insn ()); |
dd1286fb | 1426 | if (thread->deleted ()) |
8deb3959 | 1427 | thread = new_rtx; |
75040552 | 1428 | } |
1429 | else | |
1430 | { | |
2cf26c51 | 1431 | update_block (merged_insns->insn (), thread); |
1432 | delete_related_insns (merged_insns->insn ()); | |
75040552 | 1433 | } |
1434 | } | |
1435 | ||
1436 | INSN_ANNULLED_BRANCH_P (delay_insn) = 0; | |
1437 | ||
1438 | for (i = 0; i < XVECLEN (PATTERN (insn), 0); i++) | |
1439 | INSN_FROM_TARGET_P (XVECEXP (PATTERN (insn), 0, i)) = 0; | |
1440 | } | |
1441 | } | |
1442 | \f | |
1443 | /* See if INSN is redundant with an insn in front of TARGET. Often this | |
1444 | is called when INSN is a candidate for a delay slot of TARGET. | |
1445 | DELAY_LIST are insns that will be placed in delay slots of TARGET in front | |
1446 | of INSN. Often INSN will be redundant with an insn in a delay slot of | |
1447 | some previous insn. This happens when we have a series of branches to the | |
1448 | same label; in that case the first insn at the target might want to go | |
1449 | into each of the delay slots. | |
1450 | ||
1451 | If we are not careful, this routine can take up a significant fraction | |
1452 | of the total compilation time (4%), but only wins rarely. Hence we | |
1453 | speed this routine up by making two passes. The first pass goes back | |
d632b59a | 1454 | until it hits a label and sees if it finds an insn with an identical |
75040552 | 1455 | pattern. Only in this (relatively rare) event does it check for |
1456 | data conflicts. | |
1457 | ||
1458 | We do not split insns we encounter. This could cause us not to find a | |
1459 | redundant insn, but the cost of splitting seems greater than the possible | |
1460 | gain in rare cases. */ | |
1461 | ||
4091a9b9 | 1462 | static rtx |
28cb74c5 | 1463 | redundant_insn (rtx insn, rtx_insn *target, const vec<rtx_insn *> &delay_list) |
75040552 | 1464 | { |
1465 | rtx target_main = target; | |
1466 | rtx ipat = PATTERN (insn); | |
91a55c11 | 1467 | rtx_insn *trial; |
1468 | rtx pat; | |
75040552 | 1469 | struct resources needed, set; |
1470 | int i; | |
21b80b12 | 1471 | unsigned insns_to_search; |
75040552 | 1472 | |
f474c2ef | 1473 | /* If INSN has any REG_UNUSED notes, it can't match anything since we |
1474 | are allowed to not actually assign to such a register. */ | |
1475 | if (find_reg_note (insn, REG_UNUSED, NULL_RTX) != 0) | |
1476 | return 0; | |
1477 | ||
75040552 | 1478 | /* Scan backwards looking for a match. */ |
21b80b12 | 1479 | for (trial = PREV_INSN (target), |
1480 | insns_to_search = MAX_DELAY_SLOT_INSN_SEARCH; | |
1481 | trial && insns_to_search > 0; | |
47730c87 | 1482 | trial = PREV_INSN (trial)) |
75040552 | 1483 | { |
8ef42ff5 | 1484 | /* (use (insn))s can come immediately after a barrier if the |
1485 | label that used to precede them has been deleted as dead. | |
1486 | See delete_related_insns. */ | |
1487 | if (LABEL_P (trial) || BARRIER_P (trial)) | |
75040552 | 1488 | return 0; |
1489 | ||
b9ed2912 | 1490 | if (!INSN_P (trial)) |
75040552 | 1491 | continue; |
47730c87 | 1492 | --insns_to_search; |
75040552 | 1493 | |
1494 | pat = PATTERN (trial); | |
1495 | if (GET_CODE (pat) == USE || GET_CODE (pat) == CLOBBER) | |
1496 | continue; | |
1497 | ||
f5c63059 | 1498 | if (rtx_sequence *seq = dyn_cast <rtx_sequence *> (pat)) |
75040552 | 1499 | { |
616987d3 | 1500 | /* Stop for a CALL and its delay slots because it is difficult to |
1501 | track its resource needs correctly. */ | |
f5c63059 | 1502 | if (CALL_P (seq->element (0))) |
75040552 | 1503 | return 0; |
1504 | ||
616987d3 | 1505 | /* Stop for an INSN or JUMP_INSN with delayed effects and its delay |
875b3f3b | 1506 | slots because it is difficult to track its resource needs |
616987d3 | 1507 | correctly. */ |
1508 | ||
d3ffa7b4 | 1509 | if (INSN_SETS_ARE_DELAYED (seq->insn (0))) |
875b3f3b | 1510 | return 0; |
616987d3 | 1511 | |
d3ffa7b4 | 1512 | if (INSN_REFERENCES_ARE_DELAYED (seq->insn (0))) |
875b3f3b | 1513 | return 0; |
616987d3 | 1514 | |
1515 | /* See if any of the insns in the delay slot match, updating | |
1516 | resource requirements as we go. */ | |
f5c63059 | 1517 | for (i = seq->len () - 1; i > 0; i--) |
1518 | if (GET_CODE (seq->element (i)) == GET_CODE (insn) | |
1519 | && rtx_equal_p (PATTERN (seq->element (i)), ipat) | |
1520 | && ! find_reg_note (seq->element (i), REG_UNUSED, NULL_RTX)) | |
75040552 | 1521 | break; |
1522 | ||
1523 | /* If found a match, exit this loop early. */ | |
1524 | if (i > 0) | |
1525 | break; | |
1526 | } | |
1527 | ||
f474c2ef | 1528 | else if (GET_CODE (trial) == GET_CODE (insn) && rtx_equal_p (pat, ipat) |
1529 | && ! find_reg_note (trial, REG_UNUSED, NULL_RTX)) | |
75040552 | 1530 | break; |
1531 | } | |
1532 | ||
1533 | /* If we didn't find an insn that matches, return 0. */ | |
1534 | if (trial == 0) | |
1535 | return 0; | |
1536 | ||
1537 | /* See what resources this insn sets and needs. If they overlap, or | |
1538 | if this insn references CC0, it can't be redundant. */ | |
1539 | ||
1540 | CLEAR_RESOURCE (&needed); | |
1541 | CLEAR_RESOURCE (&set); | |
d2137327 | 1542 | mark_set_resources (insn, &set, 0, MARK_SRC_DEST_CALL); |
10a15ee4 | 1543 | mark_referenced_resources (insn, &needed, true); |
75040552 | 1544 | |
1545 | /* If TARGET is a SEQUENCE, get the main insn. */ | |
6d7dc5b9 | 1546 | if (NONJUMP_INSN_P (target) && GET_CODE (PATTERN (target)) == SEQUENCE) |
75040552 | 1547 | target_main = XVECEXP (PATTERN (target), 0, 0); |
1548 | ||
1549 | if (resource_conflicts_p (&needed, &set) | |
ff900b8e | 1550 | || (HAVE_cc0 && reg_mentioned_p (cc0_rtx, ipat)) |
75040552 | 1551 | /* The insn requiring the delay may not set anything needed or set by |
1552 | INSN. */ | |
10a15ee4 | 1553 | || insn_sets_resource_p (target_main, &needed, true) |
1554 | || insn_sets_resource_p (target_main, &set, true)) | |
75040552 | 1555 | return 0; |
1556 | ||
1557 | /* Insns we pass may not set either NEEDED or SET, so merge them for | |
1558 | simpler tests. */ | |
1559 | needed.memory |= set.memory; | |
1560 | IOR_HARD_REG_SET (needed.regs, set.regs); | |
1561 | ||
1562 | /* This insn isn't redundant if it conflicts with an insn that either is | |
1563 | or will be in a delay slot of TARGET. */ | |
1564 | ||
28cb74c5 | 1565 | unsigned int j; |
1566 | rtx_insn *temp; | |
1567 | FOR_EACH_VEC_ELT (delay_list, j, temp) | |
1568 | if (insn_sets_resource_p (temp, &needed, true)) | |
1569 | return 0; | |
75040552 | 1570 | |
6d7dc5b9 | 1571 | if (NONJUMP_INSN_P (target) && GET_CODE (PATTERN (target)) == SEQUENCE) |
75040552 | 1572 | for (i = 1; i < XVECLEN (PATTERN (target), 0); i++) |
10a15ee4 | 1573 | if (insn_sets_resource_p (XVECEXP (PATTERN (target), 0, i), &needed, |
1574 | true)) | |
75040552 | 1575 | return 0; |
1576 | ||
1577 | /* Scan backwards until we reach a label or an insn that uses something | |
1578 | INSN sets or sets something insn uses or sets. */ | |
1579 | ||
21b80b12 | 1580 | for (trial = PREV_INSN (target), |
1581 | insns_to_search = MAX_DELAY_SLOT_INSN_SEARCH; | |
6d7dc5b9 | 1582 | trial && !LABEL_P (trial) && insns_to_search > 0; |
47730c87 | 1583 | trial = PREV_INSN (trial)) |
75040552 | 1584 | { |
b9ed2912 | 1585 | if (!INSN_P (trial)) |
75040552 | 1586 | continue; |
47730c87 | 1587 | --insns_to_search; |
75040552 | 1588 | |
1589 | pat = PATTERN (trial); | |
1590 | if (GET_CODE (pat) == USE || GET_CODE (pat) == CLOBBER) | |
1591 | continue; | |
1592 | ||
f5c63059 | 1593 | if (rtx_sequence *seq = dyn_cast <rtx_sequence *> (pat)) |
75040552 | 1594 | { |
7e66a69e | 1595 | bool annul_p = false; |
d3ffa7b4 | 1596 | rtx_insn *control = seq->insn (0); |
7e66a69e | 1597 | |
75040552 | 1598 | /* If this is a CALL_INSN and its delay slots, it is hard to track |
1599 | the resource needs properly, so give up. */ | |
7e66a69e | 1600 | if (CALL_P (control)) |
75040552 | 1601 | return 0; |
1602 | ||
3398e91d | 1603 | /* If this is an INSN or JUMP_INSN with delayed effects, it |
616987d3 | 1604 | is hard to track the resource needs properly, so give up. */ |
1605 | ||
7e66a69e | 1606 | if (INSN_SETS_ARE_DELAYED (control)) |
875b3f3b | 1607 | return 0; |
616987d3 | 1608 | |
7e66a69e | 1609 | if (INSN_REFERENCES_ARE_DELAYED (control)) |
875b3f3b | 1610 | return 0; |
616987d3 | 1611 | |
7e66a69e | 1612 | if (JUMP_P (control)) |
1613 | annul_p = INSN_ANNULLED_BRANCH_P (control); | |
1614 | ||
75040552 | 1615 | /* See if any of the insns in the delay slot match, updating |
1616 | resource requirements as we go. */ | |
f5c63059 | 1617 | for (i = seq->len () - 1; i > 0; i--) |
75040552 | 1618 | { |
f5c63059 | 1619 | rtx candidate = seq->element (i); |
75040552 | 1620 | |
1621 | /* If an insn will be annulled if the branch is false, it isn't | |
1622 | considered as a possible duplicate insn. */ | |
1623 | if (rtx_equal_p (PATTERN (candidate), ipat) | |
7e66a69e | 1624 | && ! (annul_p && INSN_FROM_TARGET_P (candidate))) |
75040552 | 1625 | { |
1626 | /* Show that this insn will be used in the sequel. */ | |
1627 | INSN_FROM_TARGET_P (candidate) = 0; | |
4091a9b9 | 1628 | return candidate; |
75040552 | 1629 | } |
1630 | ||
1631 | /* Unless this is an annulled insn from the target of a branch, | |
1632 | we must stop if it sets anything needed or set by INSN. */ | |
7e66a69e | 1633 | if ((!annul_p || !INSN_FROM_TARGET_P (candidate)) |
10a15ee4 | 1634 | && insn_sets_resource_p (candidate, &needed, true)) |
75040552 | 1635 | return 0; |
1636 | } | |
1637 | ||
875b3f3b | 1638 | /* If the insn requiring the delay slot conflicts with INSN, we |
75040552 | 1639 | must stop. */ |
7e66a69e | 1640 | if (insn_sets_resource_p (control, &needed, true)) |
75040552 | 1641 | return 0; |
1642 | } | |
1643 | else | |
1644 | { | |
1645 | /* See if TRIAL is the same as INSN. */ | |
1646 | pat = PATTERN (trial); | |
1647 | if (rtx_equal_p (pat, ipat)) | |
4091a9b9 | 1648 | return trial; |
75040552 | 1649 | |
1650 | /* Can't go any further if TRIAL conflicts with INSN. */ | |
10a15ee4 | 1651 | if (insn_sets_resource_p (trial, &needed, true)) |
75040552 | 1652 | return 0; |
1653 | } | |
1654 | } | |
1655 | ||
1656 | return 0; | |
1657 | } | |
1658 | \f | |
7fd957fe | 1659 | /* Return 1 if THREAD can only be executed in one way. If LABEL is nonzero, |
75040552 | 1660 | it is the target of the branch insn being scanned. If ALLOW_FALLTHROUGH |
7fd957fe | 1661 | is nonzero, we are allowed to fall into this thread; otherwise, we are |
75040552 | 1662 | not. |
1663 | ||
1664 | If LABEL is used more than one or we pass a label other than LABEL before | |
1665 | finding an active insn, we do not own this thread. */ | |
1666 | ||
1667 | static int | |
c2c03a95 | 1668 | own_thread_p (rtx thread, rtx label, int allow_fallthrough) |
75040552 | 1669 | { |
91a55c11 | 1670 | rtx_insn *active_insn; |
1671 | rtx_insn *insn; | |
75040552 | 1672 | |
1673 | /* We don't own the function end. */ | |
4115ac36 | 1674 | if (thread == 0 || ANY_RETURN_P (thread)) |
75040552 | 1675 | return 0; |
1676 | ||
c2c03a95 | 1677 | /* We have a non-NULL insn. */ |
1678 | rtx_insn *thread_insn = as_a <rtx_insn *> (thread); | |
1679 | ||
1680 | /* Get the first active insn, or THREAD_INSN, if it is an active insn. */ | |
1681 | active_insn = next_active_insn (PREV_INSN (thread_insn)); | |
75040552 | 1682 | |
c2c03a95 | 1683 | for (insn = thread_insn; insn != active_insn; insn = NEXT_INSN (insn)) |
6d7dc5b9 | 1684 | if (LABEL_P (insn) |
75040552 | 1685 | && (insn != label || LABEL_NUSES (insn) != 1)) |
1686 | return 0; | |
1687 | ||
1688 | if (allow_fallthrough) | |
1689 | return 1; | |
1690 | ||
1691 | /* Ensure that we reach a BARRIER before any insn or label. */ | |
c2c03a95 | 1692 | for (insn = prev_nonnote_insn (thread_insn); |
6d7dc5b9 | 1693 | insn == 0 || !BARRIER_P (insn); |
75040552 | 1694 | insn = prev_nonnote_insn (insn)) |
1695 | if (insn == 0 | |
6d7dc5b9 | 1696 | || LABEL_P (insn) |
1697 | || (NONJUMP_INSN_P (insn) | |
75040552 | 1698 | && GET_CODE (PATTERN (insn)) != USE |
1699 | && GET_CODE (PATTERN (insn)) != CLOBBER)) | |
1700 | return 0; | |
1701 | ||
1702 | return 1; | |
1703 | } | |
1704 | \f | |
75040552 | 1705 | /* Called when INSN is being moved from a location near the target of a jump. |
e15ec77c | 1706 | We leave a marker of the form (use (INSN)) immediately in front |
75040552 | 1707 | of WHERE for mark_target_live_regs. These markers will be deleted when |
e15ec77c | 1708 | reorg finishes. |
1709 | ||
1710 | We used to try to update the live status of registers if WHERE is at | |
1711 | the start of a basic block, but that can't work since we may remove a | |
1712 | BARRIER in relax_delay_slots. */ | |
75040552 | 1713 | |
1714 | static void | |
2cf26c51 | 1715 | update_block (rtx_insn *insn, rtx where) |
75040552 | 1716 | { |
875b3f3b | 1717 | /* Ignore if this was in a delay slot and it came from the target of |
75040552 | 1718 | a branch. */ |
1719 | if (INSN_FROM_TARGET_P (insn)) | |
1720 | return; | |
1721 | ||
941522d6 | 1722 | emit_insn_before (gen_rtx_USE (VOIDmode, insn), where); |
75040552 | 1723 | |
1724 | /* INSN might be making a value live in a block where it didn't use to | |
1725 | be. So recompute liveness information for this block. */ | |
e15ec77c | 1726 | |
29bd1808 | 1727 | incr_ticks_for_insn (insn); |
75040552 | 1728 | } |
025ca893 | 1729 | |
ed6ab6b4 | 1730 | /* Similar to REDIRECT_JUMP except that we update the BB_TICKS entry for |
1731 | the basic block containing the jump. */ | |
1732 | ||
1733 | static int | |
f9a00e9e | 1734 | reorg_redirect_jump (rtx_jump_insn *jump, rtx nlabel) |
ed6ab6b4 | 1735 | { |
29bd1808 | 1736 | incr_ticks_for_insn (jump); |
f8cacb57 | 1737 | return redirect_jump (jump, nlabel, 1); |
ed6ab6b4 | 1738 | } |
1739 | ||
025ca893 | 1740 | /* Called when INSN is being moved forward into a delay slot of DELAYED_INSN. |
1741 | We check every instruction between INSN and DELAYED_INSN for REG_DEAD notes | |
1742 | that reference values used in INSN. If we find one, then we move the | |
1743 | REG_DEAD note to INSN. | |
1744 | ||
77aa6362 | 1745 | This is needed to handle the case where a later insn (after INSN) has a |
025ca893 | 1746 | REG_DEAD note for a register used by INSN, and this later insn subsequently |
1747 | gets moved before a CODE_LABEL because it is a redundant insn. In this | |
1748 | case, mark_target_live_regs may be confused into thinking the register | |
1749 | is dead because it sees a REG_DEAD note immediately before a CODE_LABEL. */ | |
1750 | ||
1751 | static void | |
f6860e7f | 1752 | update_reg_dead_notes (rtx_insn *insn, rtx_insn *delayed_insn) |
025ca893 | 1753 | { |
bf79ca12 | 1754 | rtx link, next; |
1755 | rtx_insn *p; | |
025ca893 | 1756 | |
1757 | for (p = next_nonnote_insn (insn); p != delayed_insn; | |
1758 | p = next_nonnote_insn (p)) | |
1759 | for (link = REG_NOTES (p); link; link = next) | |
1760 | { | |
1761 | next = XEXP (link, 1); | |
1762 | ||
1763 | if (REG_NOTE_KIND (link) != REG_DEAD | |
8ad4c111 | 1764 | || !REG_P (XEXP (link, 0))) |
025ca893 | 1765 | continue; |
1766 | ||
1767 | if (reg_referenced_p (XEXP (link, 0), PATTERN (insn))) | |
1768 | { | |
1769 | /* Move the REG_DEAD note from P to INSN. */ | |
1770 | remove_note (p, link); | |
1771 | XEXP (link, 1) = REG_NOTES (insn); | |
1772 | REG_NOTES (insn) = link; | |
1773 | } | |
1774 | } | |
1775 | } | |
4091a9b9 | 1776 | |
3c1d64d4 | 1777 | /* Called when an insn redundant with start_insn is deleted. If there |
1778 | is a REG_DEAD note for the target of start_insn between start_insn | |
1779 | and stop_insn, then the REG_DEAD note needs to be deleted since the | |
1780 | value no longer dies there. | |
1781 | ||
1782 | If the REG_DEAD note isn't deleted, then mark_target_live_regs may be | |
1783 | confused into thinking the register is dead. */ | |
1784 | ||
1785 | static void | |
3ad4992f | 1786 | fix_reg_dead_note (rtx start_insn, rtx stop_insn) |
3c1d64d4 | 1787 | { |
bf79ca12 | 1788 | rtx link, next; |
1789 | rtx_insn *p; | |
3c1d64d4 | 1790 | |
1791 | for (p = next_nonnote_insn (start_insn); p != stop_insn; | |
1792 | p = next_nonnote_insn (p)) | |
1793 | for (link = REG_NOTES (p); link; link = next) | |
1794 | { | |
1795 | next = XEXP (link, 1); | |
1796 | ||
1797 | if (REG_NOTE_KIND (link) != REG_DEAD | |
8ad4c111 | 1798 | || !REG_P (XEXP (link, 0))) |
3c1d64d4 | 1799 | continue; |
1800 | ||
1801 | if (reg_set_p (XEXP (link, 0), PATTERN (start_insn))) | |
1802 | { | |
1803 | remove_note (p, link); | |
1804 | return; | |
1805 | } | |
1806 | } | |
1807 | } | |
1808 | ||
4091a9b9 | 1809 | /* Delete any REG_UNUSED notes that exist on INSN but not on REDUNDANT_INSN. |
1810 | ||
1811 | This handles the case of udivmodXi4 instructions which optimize their | |
1812 | output depending on whether any REG_UNUSED notes are present. | |
1813 | we must make sure that INSN calculates as many results as REDUNDANT_INSN | |
1814 | does. */ | |
1815 | ||
1816 | static void | |
3ad4992f | 1817 | update_reg_unused_notes (rtx insn, rtx redundant_insn) |
4091a9b9 | 1818 | { |
b44bc055 | 1819 | rtx link, next; |
4091a9b9 | 1820 | |
1821 | for (link = REG_NOTES (insn); link; link = next) | |
1822 | { | |
1823 | next = XEXP (link, 1); | |
1824 | ||
1825 | if (REG_NOTE_KIND (link) != REG_UNUSED | |
8ad4c111 | 1826 | || !REG_P (XEXP (link, 0))) |
4091a9b9 | 1827 | continue; |
1828 | ||
1829 | if (! find_regno_note (redundant_insn, REG_UNUSED, | |
1830 | REGNO (XEXP (link, 0)))) | |
1831 | remove_note (insn, link); | |
1832 | } | |
1833 | } | |
75040552 | 1834 | \f |
14e08599 | 1835 | static vec <rtx> sibling_labels; |
1836 | ||
1837 | /* Return the label before INSN, or put a new label there. If SIBLING is | |
1838 | non-zero, it is another label associated with the new label (if any), | |
1839 | typically the former target of the jump that will be redirected to | |
1840 | the new label. */ | |
e3766402 | 1841 | |
575a12f2 | 1842 | static rtx_insn * |
91a55c11 | 1843 | get_label_before (rtx_insn *insn, rtx sibling) |
e3766402 | 1844 | { |
575a12f2 | 1845 | rtx_insn *label; |
e3766402 | 1846 | |
1847 | /* Find an existing label at this point | |
1848 | or make a new one if there is none. */ | |
1849 | label = prev_nonnote_insn (insn); | |
1850 | ||
1851 | if (label == 0 || !LABEL_P (label)) | |
1852 | { | |
158a522b | 1853 | rtx_insn *prev = PREV_INSN (insn); |
e3766402 | 1854 | |
1855 | label = gen_label_rtx (); | |
1856 | emit_label_after (label, prev); | |
1857 | LABEL_NUSES (label) = 0; | |
14e08599 | 1858 | if (sibling) |
1859 | { | |
1860 | sibling_labels.safe_push (label); | |
1861 | sibling_labels.safe_push (sibling); | |
1862 | } | |
e3766402 | 1863 | } |
1864 | return label; | |
1865 | } | |
1866 | ||
75040552 | 1867 | /* Scan a function looking for insns that need a delay slot and find insns to |
1868 | put into the delay slot. | |
1869 | ||
7fd957fe | 1870 | NON_JUMPS_P is nonzero if we are to only try to fill non-jump insns (such |
75040552 | 1871 | as calls). We do these first since we don't want jump insns (that are |
1872 | easier to fill) to get the only insns that could be used for non-jump insns. | |
1873 | When it is zero, only try to fill JUMP_INSNs. | |
1874 | ||
1875 | When slots are filled in this manner, the insns (including the | |
1876 | delay_insn) are put together in a SEQUENCE rtx. In this fashion, | |
1877 | it is possible to tell whether a delay slot has really been filled | |
1878 | or not. `final' knows how to deal with this, by communicating | |
1879 | through FINAL_SEQUENCE. */ | |
1880 | ||
1881 | static void | |
3ad4992f | 1882 | fill_simple_delay_slots (int non_jumps_p) |
75040552 | 1883 | { |
575a12f2 | 1884 | rtx_insn *insn, *trial, *next_trial; |
1885 | rtx pat; | |
19cb6b50 | 1886 | int i; |
75040552 | 1887 | int num_unfilled_slots = unfilled_slots_next - unfilled_slots_base; |
1888 | struct resources needed, set; | |
20b163c0 | 1889 | int slots_to_fill, slots_filled; |
28cb74c5 | 1890 | auto_vec<rtx_insn *, 5> delay_list; |
75040552 | 1891 | |
1892 | for (i = 0; i < num_unfilled_slots; i++) | |
1893 | { | |
45c67dee | 1894 | int flags; |
75040552 | 1895 | /* Get the next insn to fill. If it has already had any slots assigned, |
1896 | we can't do anything with it. Maybe we'll improve this later. */ | |
1897 | ||
1898 | insn = unfilled_slots_base[i]; | |
1899 | if (insn == 0 | |
dd1286fb | 1900 | || insn->deleted () |
6d7dc5b9 | 1901 | || (NONJUMP_INSN_P (insn) |
75040552 | 1902 | && GET_CODE (PATTERN (insn)) == SEQUENCE) |
6d7dc5b9 | 1903 | || (JUMP_P (insn) && non_jumps_p) |
1904 | || (!JUMP_P (insn) && ! non_jumps_p)) | |
75040552 | 1905 | continue; |
875b3f3b | 1906 | |
7014838c | 1907 | /* It may have been that this insn used to need delay slots, but |
1908 | now doesn't; ignore in that case. This can happen, for example, | |
1909 | on the HP PA RISC, where the number of delay slots depends on | |
1910 | what insns are nearby. */ | |
75040552 | 1911 | slots_to_fill = num_delay_slots (insn); |
a51cb8eb | 1912 | |
1913 | /* Some machine description have defined instructions to have | |
1914 | delay slots only in certain circumstances which may depend on | |
1915 | nearby insns (which change due to reorg's actions). | |
1916 | ||
1917 | For example, the PA port normally has delay slots for unconditional | |
1918 | jumps. | |
1919 | ||
1920 | However, the PA port claims such jumps do not have a delay slot | |
1921 | if they are immediate successors of certain CALL_INSNs. This | |
1922 | allows the port to favor filling the delay slot of the call with | |
1923 | the unconditional jump. */ | |
75040552 | 1924 | if (slots_to_fill == 0) |
a51cb8eb | 1925 | continue; |
75040552 | 1926 | |
1927 | /* This insn needs, or can use, some delay slots. SLOTS_TO_FILL | |
65819a09 | 1928 | says how many. After initialization, first try optimizing |
1929 | ||
1930 | call _foo call _foo | |
1931 | nop add %o7,.-L1,%o7 | |
1932 | b,a L1 | |
1933 | nop | |
1934 | ||
1935 | If this case applies, the delay slot of the call is filled with | |
1936 | the unconditional jump. This is done first to avoid having the | |
1937 | delay slot of the call filled in the backward scan. Also, since | |
1938 | the unconditional jump is likely to also have a delay slot, that | |
aa24b65f | 1939 | insn must exist when it is subsequently scanned. |
1940 | ||
1941 | This is tried on each insn with delay slots as some machines | |
875b3f3b | 1942 | have insns which perform calls, but are not represented as |
aa24b65f | 1943 | CALL_INSNs. */ |
65819a09 | 1944 | |
1945 | slots_filled = 0; | |
28cb74c5 | 1946 | delay_list.truncate (0); |
65819a09 | 1947 | |
6d7dc5b9 | 1948 | if (JUMP_P (insn)) |
7014838c | 1949 | flags = get_jump_flags (insn, JUMP_LABEL (insn)); |
1950 | else | |
1951 | flags = get_jump_flags (insn, NULL_RTX); | |
1952 | ||
aa24b65f | 1953 | if ((trial = next_active_insn (insn)) |
6d7dc5b9 | 1954 | && JUMP_P (trial) |
65819a09 | 1955 | && simplejump_p (trial) |
45c67dee | 1956 | && eligible_for_delay (insn, slots_filled, trial, flags) |
55427c62 | 1957 | && no_labels_between_p (insn, trial) |
1958 | && ! can_throw_internal (trial)) | |
65819a09 | 1959 | { |
575a12f2 | 1960 | rtx_insn **tmp; |
65819a09 | 1961 | slots_filled++; |
28cb74c5 | 1962 | add_to_delay_list (trial, &delay_list); |
e6836d7e | 1963 | |
1964 | /* TRIAL may have had its delay slot filled, then unfilled. When | |
1965 | the delay slot is unfilled, TRIAL is placed back on the unfilled | |
1966 | slots obstack. Unfortunately, it is placed on the end of the | |
1967 | obstack, not in its original location. Therefore, we must search | |
1968 | from entry i + 1 to the end of the unfilled slots obstack to | |
1969 | try and find TRIAL. */ | |
1970 | tmp = &unfilled_slots_base[i + 1]; | |
1971 | while (*tmp != trial && tmp != unfilled_slots_next) | |
1972 | tmp++; | |
1973 | ||
65819a09 | 1974 | /* Remove the unconditional jump from consideration for delay slot |
1e625a2e | 1975 | filling and unthread it. */ |
e6836d7e | 1976 | if (*tmp == trial) |
1977 | *tmp = 0; | |
65819a09 | 1978 | { |
575a12f2 | 1979 | rtx_insn *next = NEXT_INSN (trial); |
1980 | rtx_insn *prev = PREV_INSN (trial); | |
65819a09 | 1981 | if (prev) |
4a57a2e8 | 1982 | SET_NEXT_INSN (prev) = next; |
65819a09 | 1983 | if (next) |
4a57a2e8 | 1984 | SET_PREV_INSN (next) = prev; |
65819a09 | 1985 | } |
1986 | } | |
1987 | ||
1988 | /* Now, scan backwards from the insn to search for a potential | |
1989 | delay-slot candidate. Stop searching when a label or jump is hit. | |
1990 | ||
75040552 | 1991 | For each candidate, if it is to go into the delay slot (moved |
1992 | forward in execution sequence), it must not need or set any resources | |
1993 | that were set by later insns and must not set any resources that | |
1994 | are needed for those insns. | |
875b3f3b | 1995 | |
75040552 | 1996 | The delay slot insn itself sets resources unless it is a call |
1997 | (in which case the called routine, not the insn itself, is doing | |
1998 | the setting). */ | |
1999 | ||
65819a09 | 2000 | if (slots_filled < slots_to_fill) |
75040552 | 2001 | { |
8f8029b2 | 2002 | /* If the flags register is dead after the insn, then we want to be |
2003 | able to accept a candidate that clobbers it. For this purpose, | |
2004 | we need to filter the flags register during life analysis, so | |
2005 | that it doesn't create RAW and WAW dependencies, while still | |
2006 | creating the necessary WAR dependencies. */ | |
2007 | bool filter_flags | |
2008 | = (slots_to_fill == 1 | |
2009 | && targetm.flags_regnum != INVALID_REGNUM | |
2010 | && find_regno_note (insn, REG_DEAD, targetm.flags_regnum)); | |
2011 | struct resources fset; | |
65819a09 | 2012 | CLEAR_RESOURCE (&needed); |
2013 | CLEAR_RESOURCE (&set); | |
d2137327 | 2014 | mark_set_resources (insn, &set, 0, MARK_SRC_DEST); |
8f8029b2 | 2015 | if (filter_flags) |
2016 | { | |
2017 | CLEAR_RESOURCE (&fset); | |
2018 | mark_set_resources (insn, &fset, 0, MARK_SRC_DEST); | |
2019 | } | |
10a15ee4 | 2020 | mark_referenced_resources (insn, &needed, false); |
75040552 | 2021 | |
65819a09 | 2022 | for (trial = prev_nonnote_insn (insn); ! stop_search_p (trial, 1); |
2023 | trial = next_trial) | |
2024 | { | |
2025 | next_trial = prev_nonnote_insn (trial); | |
75040552 | 2026 | |
65819a09 | 2027 | /* This must be an INSN or CALL_INSN. */ |
2028 | pat = PATTERN (trial); | |
2029 | ||
2bb76f12 | 2030 | /* Stand-alone USE and CLOBBER are just for flow. */ |
65819a09 | 2031 | if (GET_CODE (pat) == USE || GET_CODE (pat) == CLOBBER) |
2032 | continue; | |
75040552 | 2033 | |
875b3f3b | 2034 | /* Check for resource conflict first, to avoid unnecessary |
65819a09 | 2035 | splitting. */ |
10a15ee4 | 2036 | if (! insn_references_resource_p (trial, &set, true) |
8f8029b2 | 2037 | && ! insn_sets_resource_p (trial, |
2038 | filter_flags ? &fset : &set, | |
2039 | true) | |
10a15ee4 | 2040 | && ! insn_sets_resource_p (trial, &needed, true) |
65819a09 | 2041 | /* Can't separate set of cc0 from its use. */ |
693c9f42 | 2042 | && (!HAVE_cc0 || ! (reg_mentioned_p (cc0_rtx, pat) && ! sets_cc0_p (pat))) |
55427c62 | 2043 | && ! can_throw_internal (trial)) |
75040552 | 2044 | { |
65819a09 | 2045 | trial = try_split (pat, trial, 1); |
2046 | next_trial = prev_nonnote_insn (trial); | |
45c67dee | 2047 | if (eligible_for_delay (insn, slots_filled, trial, flags)) |
65819a09 | 2048 | { |
2049 | /* In this case, we are searching backward, so if we | |
2050 | find insns to put on the delay list, we want | |
2051 | to put them at the head, rather than the | |
2052 | tail, of the list. */ | |
2053 | ||
025ca893 | 2054 | update_reg_dead_notes (trial, insn); |
28cb74c5 | 2055 | delay_list.safe_insert (0, trial); |
65819a09 | 2056 | update_block (trial, trial); |
e4bf866d | 2057 | delete_related_insns (trial); |
65819a09 | 2058 | if (slots_to_fill == ++slots_filled) |
2059 | break; | |
2060 | continue; | |
2061 | } | |
75040552 | 2062 | } |
75040552 | 2063 | |
d2137327 | 2064 | mark_set_resources (trial, &set, 0, MARK_SRC_DEST_CALL); |
8f8029b2 | 2065 | if (filter_flags) |
2066 | { | |
2067 | mark_set_resources (trial, &fset, 0, MARK_SRC_DEST_CALL); | |
2068 | /* If the flags register is set, then it doesn't create RAW | |
2069 | dependencies any longer and it also doesn't create WAW | |
2070 | dependencies since it's dead after the original insn. */ | |
2071 | if (TEST_HARD_REG_BIT (fset.regs, targetm.flags_regnum)) | |
2072 | { | |
2073 | CLEAR_HARD_REG_BIT (needed.regs, targetm.flags_regnum); | |
2074 | CLEAR_HARD_REG_BIT (fset.regs, targetm.flags_regnum); | |
2075 | } | |
2076 | } | |
10a15ee4 | 2077 | mark_referenced_resources (trial, &needed, true); |
65819a09 | 2078 | } |
75040552 | 2079 | } |
2080 | ||
75040552 | 2081 | /* If all needed slots haven't been filled, we come here. */ |
2082 | ||
2083 | /* Try to optimize case of jumping around a single insn. */ | |
9d463a01 | 2084 | if ((ANNUL_IFTRUE_SLOTS || ANNUL_IFFALSE_SLOTS) |
2085 | && slots_filled != slots_to_fill | |
28cb74c5 | 2086 | && delay_list.is_empty () |
6d7dc5b9 | 2087 | && JUMP_P (insn) |
f209c23d | 2088 | && (condjump_p (insn) || condjump_in_parallel_p (insn)) |
2089 | && !ANY_RETURN_P (JUMP_LABEL (insn))) | |
75040552 | 2090 | { |
28cb74c5 | 2091 | optimize_skip (as_a <rtx_jump_insn *> (insn), &delay_list); |
2092 | if (!delay_list.is_empty ()) | |
75040552 | 2093 | slots_filled += 1; |
2094 | } | |
75040552 | 2095 | |
75040552 | 2096 | /* Try to get insns from beyond the insn needing the delay slot. |
2097 | These insns can neither set or reference resources set in insns being | |
2098 | skipped, cannot set resources in the insn being skipped, and, if this | |
2099 | is a CALL_INSN (or a CALL_INSN is passed), cannot trap (because the | |
2100 | call might not return). | |
2101 | ||
2d3e6765 | 2102 | There used to be code which continued past the target label if |
2103 | we saw all uses of the target label. This code did not work, | |
2104 | because it failed to account for some instructions which were | |
2105 | both annulled and marked as from the target. This can happen as a | |
2106 | result of optimize_skip. Since this code was redundant with | |
2107 | fill_eager_delay_slots anyways, it was just deleted. */ | |
75040552 | 2108 | |
da6f8527 | 2109 | if (slots_filled != slots_to_fill |
efb2ee17 | 2110 | /* If this instruction could throw an exception which is |
2111 | caught in the same function, then it's not safe to fill | |
2112 | the delay slot with an instruction from beyond this | |
2113 | point. For example, consider: | |
2114 | ||
2115 | int i = 2; | |
2116 | ||
ed1e5d40 | 2117 | try { |
efb2ee17 | 2118 | f(); |
2119 | i = 3; | |
2120 | } catch (...) {} | |
ed1e5d40 | 2121 | |
efb2ee17 | 2122 | return i; |
2123 | ||
2124 | Even though `i' is a local variable, we must be sure not | |
2125 | to put `i = 3' in the delay slot if `f' might throw an | |
2126 | exception. | |
2127 | ||
2128 | Presumably, we should also check to see if we could get | |
2129 | back to this function via `setjmp'. */ | |
55427c62 | 2130 | && ! can_throw_internal (insn) |
965df672 | 2131 | && !JUMP_P (insn)) |
75040552 | 2132 | { |
75040552 | 2133 | int maybe_never = 0; |
21b80b12 | 2134 | rtx pat, trial_delay; |
75040552 | 2135 | |
2136 | CLEAR_RESOURCE (&needed); | |
2137 | CLEAR_RESOURCE (&set); | |
965df672 | 2138 | mark_set_resources (insn, &set, 0, MARK_SRC_DEST_CALL); |
2139 | mark_referenced_resources (insn, &needed, true); | |
75040552 | 2140 | |
6d7dc5b9 | 2141 | if (CALL_P (insn)) |
965df672 | 2142 | maybe_never = 1; |
75040552 | 2143 | |
fdb35bef | 2144 | for (trial = next_nonnote_insn (insn); !stop_search_p (trial, 1); |
2145 | trial = next_trial) | |
2146 | { | |
2147 | next_trial = next_nonnote_insn (trial); | |
75040552 | 2148 | |
fdb35bef | 2149 | /* This must be an INSN or CALL_INSN. */ |
2150 | pat = PATTERN (trial); | |
75040552 | 2151 | |
fdb35bef | 2152 | /* Stand-alone USE and CLOBBER are just for flow. */ |
2153 | if (GET_CODE (pat) == USE || GET_CODE (pat) == CLOBBER) | |
2154 | continue; | |
2155 | ||
2156 | /* If this already has filled delay slots, get the insn needing | |
2157 | the delay slots. */ | |
2158 | if (GET_CODE (pat) == SEQUENCE) | |
2159 | trial_delay = XVECEXP (pat, 0, 0); | |
2160 | else | |
2161 | trial_delay = trial; | |
2162 | ||
2163 | /* Stop our search when seeing a jump. */ | |
2164 | if (JUMP_P (trial_delay)) | |
2165 | break; | |
75040552 | 2166 | |
fdb35bef | 2167 | /* See if we have a resource problem before we try to split. */ |
2168 | if (GET_CODE (pat) != SEQUENCE | |
2169 | && ! insn_references_resource_p (trial, &set, true) | |
2170 | && ! insn_sets_resource_p (trial, &set, true) | |
2171 | && ! insn_sets_resource_p (trial, &needed, true) | |
693c9f42 | 2172 | && (!HAVE_cc0 && ! (reg_mentioned_p (cc0_rtx, pat) && ! sets_cc0_p (pat))) |
fdb35bef | 2173 | && ! (maybe_never && may_trap_or_fault_p (pat)) |
2174 | && (trial = try_split (pat, trial, 0)) | |
2175 | && eligible_for_delay (insn, slots_filled, trial, flags) | |
9af5ce0c | 2176 | && ! can_throw_internal (trial)) |
fdb35bef | 2177 | { |
2178 | next_trial = next_nonnote_insn (trial); | |
28cb74c5 | 2179 | add_to_delay_list (trial, &delay_list); |
ff900b8e | 2180 | if (HAVE_cc0 && reg_mentioned_p (cc0_rtx, pat)) |
fdb35bef | 2181 | link_cc0_insns (trial); |
ff900b8e | 2182 | |
fdb35bef | 2183 | delete_related_insns (trial); |
2184 | if (slots_to_fill == ++slots_filled) | |
2185 | break; | |
2186 | continue; | |
2187 | } | |
75040552 | 2188 | |
fdb35bef | 2189 | mark_set_resources (trial, &set, 0, MARK_SRC_DEST_CALL); |
2190 | mark_referenced_resources (trial, &needed, true); | |
75040552 | 2191 | |
fdb35bef | 2192 | /* Ensure we don't put insns between the setting of cc and the |
2193 | comparison by moving a setting of cc into an earlier delay | |
2194 | slot since these insns could clobber the condition code. */ | |
2195 | set.cc = 1; | |
75040552 | 2196 | |
fdb35bef | 2197 | /* If this is a call, we might not get here. */ |
2198 | if (CALL_P (trial_delay)) | |
2199 | maybe_never = 1; | |
2200 | } | |
75040552 | 2201 | |
2202 | /* If there are slots left to fill and our search was stopped by an | |
2203 | unconditional branch, try the insn at the branch target. We can | |
875b3f3b | 2204 | redirect the branch if it works. |
6bd5d07a | 2205 | |
2206 | Don't do this if the insn at the branch target is a branch. */ | |
75040552 | 2207 | if (slots_to_fill != slots_filled |
2208 | && trial | |
4115ac36 | 2209 | && jump_to_label_p (trial) |
75040552 | 2210 | && simplejump_p (trial) |
75040552 | 2211 | && (next_trial = next_active_insn (JUMP_LABEL (trial))) != 0 |
6d7dc5b9 | 2212 | && ! (NONJUMP_INSN_P (next_trial) |
75040552 | 2213 | && GET_CODE (PATTERN (next_trial)) == SEQUENCE) |
6d7dc5b9 | 2214 | && !JUMP_P (next_trial) |
10a15ee4 | 2215 | && ! insn_references_resource_p (next_trial, &set, true) |
2216 | && ! insn_sets_resource_p (next_trial, &set, true) | |
2217 | && ! insn_sets_resource_p (next_trial, &needed, true) | |
693c9f42 | 2218 | && (!HAVE_cc0 || ! reg_mentioned_p (cc0_rtx, PATTERN (next_trial))) |
1aecae7f | 2219 | && ! (maybe_never && may_trap_or_fault_p (PATTERN (next_trial))) |
75040552 | 2220 | && (next_trial = try_split (PATTERN (next_trial), next_trial, 0)) |
55427c62 | 2221 | && eligible_for_delay (insn, slots_filled, next_trial, flags) |
2222 | && ! can_throw_internal (trial)) | |
75040552 | 2223 | { |
f17979aa | 2224 | /* See comment in relax_delay_slots about necessity of using |
2225 | next_real_insn here. */ | |
91a55c11 | 2226 | rtx_insn *new_label = next_real_insn (next_trial); |
75040552 | 2227 | |
2228 | if (new_label != 0) | |
14e08599 | 2229 | new_label = get_label_before (new_label, JUMP_LABEL (trial)); |
a90318fb | 2230 | else |
9cb2517e | 2231 | new_label = find_end_label (simple_return_rtx); |
75040552 | 2232 | |
920d6e22 | 2233 | if (new_label) |
2234 | { | |
28cb74c5 | 2235 | add_to_delay_list (copy_delay_slot_insn (next_trial), |
2236 | &delay_list); | |
920d6e22 | 2237 | slots_filled++; |
f9a00e9e | 2238 | reorg_redirect_jump (as_a <rtx_jump_insn *> (trial), |
2239 | new_label); | |
920d6e22 | 2240 | } |
75040552 | 2241 | } |
2242 | } | |
2243 | ||
20b163c0 | 2244 | /* If this is an unconditional jump, then try to get insns from the |
2245 | target of the jump. */ | |
f9a00e9e | 2246 | rtx_jump_insn *jump_insn; |
2247 | if ((jump_insn = dyn_cast <rtx_jump_insn *> (insn)) | |
2248 | && simplejump_p (jump_insn) | |
20b163c0 | 2249 | && slots_filled != slots_to_fill) |
28cb74c5 | 2250 | fill_slots_from_thread (jump_insn, const_true_rtx, |
2251 | next_active_insn (JUMP_LABEL (insn)), NULL, 1, | |
2252 | 1, own_thread_p (JUMP_LABEL (insn), | |
2253 | JUMP_LABEL (insn), 0), | |
2254 | slots_to_fill, &slots_filled, &delay_list); | |
2255 | ||
2256 | if (!delay_list.is_empty ()) | |
75040552 | 2257 | unfilled_slots_base[i] |
b44bc055 | 2258 | = emit_delay_sequence (insn, delay_list, slots_filled); |
75040552 | 2259 | |
2260 | if (slots_to_fill == slots_filled) | |
2261 | unfilled_slots_base[i] = 0; | |
2262 | ||
2263 | note_delay_statistics (slots_filled, 0); | |
2264 | } | |
75040552 | 2265 | } |
2266 | \f | |
c7b4d9b2 | 2267 | /* Follow any unconditional jump at LABEL, for the purpose of redirecting JUMP; |
e3766402 | 2268 | return the ultimate label reached by any such chain of jumps. |
9cb2517e | 2269 | Return a suitable return rtx if the chain ultimately leads to a |
2270 | return instruction. | |
e3766402 | 2271 | If LABEL is not followed by a jump, return LABEL. |
2272 | If the chain loops or we can't find end, return LABEL, | |
c7b4d9b2 | 2273 | since that tells caller to avoid changing the insn. |
8f869004 | 2274 | If the returned label is obtained by following a crossing jump, |
2275 | set *CROSSING to true, otherwise set it to false. */ | |
e3766402 | 2276 | |
c2c03a95 | 2277 | static rtx |
484e0746 | 2278 | follow_jumps (rtx label, rtx_insn *jump, bool *crossing) |
e3766402 | 2279 | { |
575a12f2 | 2280 | rtx_insn *insn; |
2281 | rtx_insn *next; | |
e3766402 | 2282 | int depth; |
2283 | ||
c7b4d9b2 | 2284 | *crossing = false; |
4115ac36 | 2285 | if (ANY_RETURN_P (label)) |
2286 | return label; | |
c2c03a95 | 2287 | |
2288 | rtx_insn *value = as_a <rtx_insn *> (label); | |
2289 | ||
e3766402 | 2290 | for (depth = 0; |
2291 | (depth < 10 | |
2292 | && (insn = next_active_insn (value)) != 0 | |
2293 | && JUMP_P (insn) | |
4115ac36 | 2294 | && JUMP_LABEL (insn) != NULL_RTX |
2295 | && ((any_uncondjump_p (insn) && onlyjump_p (insn)) | |
9cb2517e | 2296 | || ANY_RETURN_P (PATTERN (insn))) |
e3766402 | 2297 | && (next = NEXT_INSN (insn)) |
2298 | && BARRIER_P (next)); | |
2299 | depth++) | |
2300 | { | |
c2c03a95 | 2301 | rtx this_label_or_return = JUMP_LABEL (insn); |
e3766402 | 2302 | |
2303 | /* If we have found a cycle, make the insn jump to itself. */ | |
c2c03a95 | 2304 | if (this_label_or_return == label) |
e3766402 | 2305 | return label; |
cd316116 | 2306 | |
2307 | /* Cannot follow returns and cannot look through tablejumps. */ | |
c2c03a95 | 2308 | if (ANY_RETURN_P (this_label_or_return)) |
2309 | return this_label_or_return; | |
2310 | ||
2311 | rtx_insn *this_label = as_a <rtx_insn *> (this_label_or_return); | |
cd316116 | 2312 | if (NEXT_INSN (this_label) |
2313 | && JUMP_TABLE_DATA_P (NEXT_INSN (this_label))) | |
e3766402 | 2314 | break; |
2315 | ||
c7b4d9b2 | 2316 | if (!targetm.can_follow_jump (jump, insn)) |
2317 | break; | |
2318 | if (!*crossing) | |
8f869004 | 2319 | *crossing = CROSSING_JUMP_P (jump); |
4115ac36 | 2320 | value = this_label; |
e3766402 | 2321 | } |
2322 | if (depth == 10) | |
2323 | return label; | |
2324 | return value; | |
2325 | } | |
2326 | ||
75040552 | 2327 | /* Try to find insns to place in delay slots. |
2328 | ||
2329 | INSN is the jump needing SLOTS_TO_FILL delay slots. It tests CONDITION | |
2330 | or is an unconditional branch if CONDITION is const_true_rtx. | |
2331 | *PSLOTS_FILLED is updated with the number of slots that we have filled. | |
2332 | ||
2333 | THREAD is a flow-of-control, either the insns to be executed if the | |
2334 | branch is true or if the branch is false, THREAD_IF_TRUE says which. | |
2335 | ||
2336 | OPPOSITE_THREAD is the thread in the opposite direction. It is used | |
2337 | to see if any potential delay slot insns set things needed there. | |
2338 | ||
7fd957fe | 2339 | LIKELY is nonzero if it is extremely likely that the branch will be |
75040552 | 2340 | taken and THREAD_IF_TRUE is set. This is used for the branch at the |
2341 | end of a loop back up to the top. | |
2342 | ||
2343 | OWN_THREAD and OWN_OPPOSITE_THREAD are true if we are the only user of the | |
2344 | thread. I.e., it is the fallthrough code of our jump or the target of the | |
2345 | jump when we are the only jump going there. | |
2346 | ||
2347 | If OWN_THREAD is false, it must be the "true" thread of a jump. In that | |
2348 | case, we can only take insns from the head of the thread for our delay | |
2349 | slot. We then adjust the jump to point after the insns we have taken. */ | |
2350 | ||
28cb74c5 | 2351 | static void |
f9a00e9e | 2352 | fill_slots_from_thread (rtx_jump_insn *insn, rtx condition, |
2353 | rtx thread_or_return, rtx opposite_thread, int likely, | |
2354 | int thread_if_true, int own_thread, int slots_to_fill, | |
28cb74c5 | 2355 | int *pslots_filled, vec<rtx_insn *> *delay_list) |
75040552 | 2356 | { |
c2c03a95 | 2357 | rtx new_thread; |
75040552 | 2358 | struct resources opposite_needed, set, needed; |
575a12f2 | 2359 | rtx_insn *trial; |
75040552 | 2360 | int lose = 0; |
2361 | int must_annul = 0; | |
45c67dee | 2362 | int flags; |
75040552 | 2363 | |
2364 | /* Validate our arguments. */ | |
9af5ce0c | 2365 | gcc_assert (condition != const_true_rtx || thread_if_true); |
2366 | gcc_assert (own_thread || thread_if_true); | |
75040552 | 2367 | |
45c67dee | 2368 | flags = get_jump_flags (insn, JUMP_LABEL (insn)); |
2369 | ||
75040552 | 2370 | /* If our thread is the end of subroutine, we can't get any delay |
2371 | insns from that. */ | |
c2c03a95 | 2372 | if (thread_or_return == NULL_RTX || ANY_RETURN_P (thread_or_return)) |
28cb74c5 | 2373 | return; |
75040552 | 2374 | |
c2c03a95 | 2375 | rtx_insn *thread = as_a <rtx_insn *> (thread_or_return); |
2376 | ||
75040552 | 2377 | /* If this is an unconditional branch, nothing is needed at the |
2378 | opposite thread. Otherwise, compute what is needed there. */ | |
2379 | if (condition == const_true_rtx) | |
2380 | CLEAR_RESOURCE (&opposite_needed); | |
2381 | else | |
29bd1808 | 2382 | mark_target_live_regs (get_insns (), opposite_thread, &opposite_needed); |
75040552 | 2383 | |
99c63f51 | 2384 | /* If the insn at THREAD can be split, do it here to avoid having to |
2385 | update THREAD and NEW_THREAD if it is done in the loop below. Also | |
2386 | initialize NEW_THREAD. */ | |
2387 | ||
f9e15121 | 2388 | new_thread = thread = try_split (PATTERN (thread), thread, 0); |
99c63f51 | 2389 | |
75040552 | 2390 | /* Scan insns at THREAD. We are looking for an insn that can be removed |
2391 | from THREAD (it neither sets nor references resources that were set | |
2392 | ahead of it and it doesn't set anything needs by the insns ahead of | |
2393 | it) and that either can be placed in an annulling insn or aren't | |
2394 | needed at OPPOSITE_THREAD. */ | |
2395 | ||
2396 | CLEAR_RESOURCE (&needed); | |
2397 | CLEAR_RESOURCE (&set); | |
2398 | ||
2399 | /* If we do not own this thread, we must stop as soon as we find | |
2400 | something that we can't put in a delay slot, since all we can do | |
2401 | is branch into THREAD at a later point. Therefore, labels stop | |
2402 | the search if this is not the `true' thread. */ | |
2403 | ||
2404 | for (trial = thread; | |
2405 | ! stop_search_p (trial, ! thread_if_true) && (! lose || own_thread); | |
2406 | trial = next_nonnote_insn (trial)) | |
2407 | { | |
bf9834c9 | 2408 | rtx pat, old_trial; |
75040552 | 2409 | |
2410 | /* If we have passed a label, we no longer own this thread. */ | |
6d7dc5b9 | 2411 | if (LABEL_P (trial)) |
75040552 | 2412 | { |
2413 | own_thread = 0; | |
2414 | continue; | |
2415 | } | |
2416 | ||
2417 | pat = PATTERN (trial); | |
2418 | if (GET_CODE (pat) == USE || GET_CODE (pat) == CLOBBER) | |
2419 | continue; | |
2420 | ||
2421 | /* If TRIAL conflicts with the insns ahead of it, we lose. Also, | |
2422 | don't separate or copy insns that set and use CC0. */ | |
10a15ee4 | 2423 | if (! insn_references_resource_p (trial, &set, true) |
2424 | && ! insn_sets_resource_p (trial, &set, true) | |
2425 | && ! insn_sets_resource_p (trial, &needed, true) | |
693c9f42 | 2426 | && (!HAVE_cc0 || (! (reg_mentioned_p (cc0_rtx, pat) |
2427 | && (! own_thread || ! sets_cc0_p (pat))))) | |
55427c62 | 2428 | && ! can_throw_internal (trial)) |
75040552 | 2429 | { |
4091a9b9 | 2430 | rtx prior_insn; |
2431 | ||
75040552 | 2432 | /* If TRIAL is redundant with some insn before INSN, we don't |
2433 | actually need to add it to the delay list; we can merely pretend | |
2434 | we did. */ | |
28cb74c5 | 2435 | if ((prior_insn = redundant_insn (trial, insn, *delay_list))) |
75040552 | 2436 | { |
3c1d64d4 | 2437 | fix_reg_dead_note (prior_insn, insn); |
75040552 | 2438 | if (own_thread) |
2439 | { | |
3d5c2032 | 2440 | update_block (trial, thread); |
9d5f32a3 | 2441 | if (trial == thread) |
31bd5562 | 2442 | { |
2443 | thread = next_active_insn (thread); | |
2444 | if (new_thread == trial) | |
2445 | new_thread = thread; | |
2446 | } | |
9d5f32a3 | 2447 | |
e4bf866d | 2448 | delete_related_insns (trial); |
75040552 | 2449 | } |
2450 | else | |
4091a9b9 | 2451 | { |
2452 | update_reg_unused_notes (prior_insn, trial); | |
e799a437 | 2453 | new_thread = next_active_insn (trial); |
4091a9b9 | 2454 | } |
75040552 | 2455 | |
2456 | continue; | |
2457 | } | |
2458 | ||
2459 | /* There are two ways we can win: If TRIAL doesn't set anything | |
2460 | needed at the opposite thread and can't trap, or if it can | |
9fcfed2e | 2461 | go into an annulled delay slot. But we want neither to copy |
2462 | nor to speculate frame-related insns. */ | |
18418794 | 2463 | if (!must_annul |
9fcfed2e | 2464 | && ((condition == const_true_rtx |
2465 | && (own_thread || !RTX_FRAME_RELATED_P (trial))) | |
10a15ee4 | 2466 | || (! insn_sets_resource_p (trial, &opposite_needed, true) |
5cbfefc3 | 2467 | && ! may_trap_or_fault_p (pat) |
2468 | && ! RTX_FRAME_RELATED_P (trial)))) | |
75040552 | 2469 | { |
bf9834c9 | 2470 | old_trial = trial; |
75040552 | 2471 | trial = try_split (pat, trial, 0); |
bf9834c9 | 2472 | if (new_thread == old_trial) |
2473 | new_thread = trial; | |
0b29ba32 | 2474 | if (thread == old_trial) |
2475 | thread = trial; | |
75040552 | 2476 | pat = PATTERN (trial); |
45c67dee | 2477 | if (eligible_for_delay (insn, *pslots_filled, trial, flags)) |
75040552 | 2478 | goto winner; |
2479 | } | |
2480 | else if (0 | |
9d463a01 | 2481 | || (ANNUL_IFTRUE_SLOTS && ! thread_if_true) |
2482 | || (ANNUL_IFFALSE_SLOTS && thread_if_true)) | |
75040552 | 2483 | { |
bf9834c9 | 2484 | old_trial = trial; |
75040552 | 2485 | trial = try_split (pat, trial, 0); |
bf9834c9 | 2486 | if (new_thread == old_trial) |
2487 | new_thread = trial; | |
470d146f | 2488 | if (thread == old_trial) |
2489 | thread = trial; | |
75040552 | 2490 | pat = PATTERN (trial); |
28cb74c5 | 2491 | if ((must_annul || delay_list->is_empty ()) && (thread_if_true |
2492 | ? check_annul_list_true_false (0, *delay_list) | |
18418794 | 2493 | && eligible_for_annul_false (insn, *pslots_filled, trial, flags) |
28cb74c5 | 2494 | : check_annul_list_true_false (1, *delay_list) |
18418794 | 2495 | && eligible_for_annul_true (insn, *pslots_filled, trial, flags))) |
75040552 | 2496 | { |
575a12f2 | 2497 | rtx_insn *temp; |
75040552 | 2498 | |
2499 | must_annul = 1; | |
2500 | winner: | |
2501 | ||
ff900b8e | 2502 | if (HAVE_cc0 && reg_mentioned_p (cc0_rtx, pat)) |
75040552 | 2503 | link_cc0_insns (trial); |
75040552 | 2504 | |
2505 | /* If we own this thread, delete the insn. If this is the | |
2506 | destination of a branch, show that a basic block status | |
2507 | may have been updated. In any case, mark the new | |
2508 | starting point of this thread. */ | |
2509 | if (own_thread) | |
2510 | { | |
9b7d4a8f | 2511 | rtx note; |
2512 | ||
3d5c2032 | 2513 | update_block (trial, thread); |
4fef6e7d | 2514 | if (trial == thread) |
2515 | { | |
2516 | thread = next_active_insn (thread); | |
2517 | if (new_thread == trial) | |
2518 | new_thread = thread; | |
2519 | } | |
9b7d4a8f | 2520 | |
2521 | /* We are moving this insn, not deleting it. We must | |
2522 | temporarily increment the use count on any referenced | |
2523 | label lest it be deleted by delete_related_insns. */ | |
19d2fe05 | 2524 | for (note = REG_NOTES (trial); |
a8d1dae0 | 2525 | note != NULL_RTX; |
19d2fe05 | 2526 | note = XEXP (note, 1)) |
2527 | if (REG_NOTE_KIND (note) == REG_LABEL_OPERAND | |
2528 | || REG_NOTE_KIND (note) == REG_LABEL_TARGET) | |
2529 | { | |
2530 | /* REG_LABEL_OPERAND could be | |
2531 | NOTE_INSN_DELETED_LABEL too. */ | |
2532 | if (LABEL_P (XEXP (note, 0))) | |
2533 | LABEL_NUSES (XEXP (note, 0))++; | |
2534 | else | |
2535 | gcc_assert (REG_NOTE_KIND (note) | |
2536 | == REG_LABEL_OPERAND); | |
2537 | } | |
4115ac36 | 2538 | if (jump_to_label_p (trial)) |
a8d1dae0 | 2539 | LABEL_NUSES (JUMP_LABEL (trial))++; |
9b7d4a8f | 2540 | |
e4bf866d | 2541 | delete_related_insns (trial); |
9b7d4a8f | 2542 | |
19d2fe05 | 2543 | for (note = REG_NOTES (trial); |
a8d1dae0 | 2544 | note != NULL_RTX; |
19d2fe05 | 2545 | note = XEXP (note, 1)) |
2546 | if (REG_NOTE_KIND (note) == REG_LABEL_OPERAND | |
2547 | || REG_NOTE_KIND (note) == REG_LABEL_TARGET) | |
2548 | { | |
2549 | /* REG_LABEL_OPERAND could be | |
2550 | NOTE_INSN_DELETED_LABEL too. */ | |
2551 | if (LABEL_P (XEXP (note, 0))) | |
2552 | LABEL_NUSES (XEXP (note, 0))--; | |
2553 | else | |
2554 | gcc_assert (REG_NOTE_KIND (note) | |
2555 | == REG_LABEL_OPERAND); | |
2556 | } | |
4115ac36 | 2557 | if (jump_to_label_p (trial)) |
a8d1dae0 | 2558 | LABEL_NUSES (JUMP_LABEL (trial))--; |
75040552 | 2559 | } |
2560 | else | |
2561 | new_thread = next_active_insn (trial); | |
2562 | ||
a9abe1f1 | 2563 | temp = own_thread ? trial : copy_delay_slot_insn (trial); |
75040552 | 2564 | if (thread_if_true) |
2565 | INSN_FROM_TARGET_P (temp) = 1; | |
2566 | ||
28cb74c5 | 2567 | add_to_delay_list (temp, delay_list); |
75040552 | 2568 | |
2569 | if (slots_to_fill == ++(*pslots_filled)) | |
2570 | { | |
2571 | /* Even though we have filled all the slots, we | |
2572 | may be branching to a location that has a | |
2573 | redundant insn. Skip any if so. */ | |
2574 | while (new_thread && ! own_thread | |
10a15ee4 | 2575 | && ! insn_sets_resource_p (new_thread, &set, true) |
2576 | && ! insn_sets_resource_p (new_thread, &needed, | |
2577 | true) | |
75040552 | 2578 | && ! insn_references_resource_p (new_thread, |
10a15ee4 | 2579 | &set, true) |
60d599be | 2580 | && (prior_insn |
2581 | = redundant_insn (new_thread, insn, | |
28cb74c5 | 2582 | *delay_list))) |
60d599be | 2583 | { |
2584 | /* We know we do not own the thread, so no need | |
2585 | to call update_block and delete_insn. */ | |
2586 | fix_reg_dead_note (prior_insn, insn); | |
2587 | update_reg_unused_notes (prior_insn, new_thread); | |
2588 | new_thread = next_active_insn (new_thread); | |
2589 | } | |
75040552 | 2590 | break; |
2591 | } | |
2592 | ||
2593 | continue; | |
2594 | } | |
2595 | } | |
2596 | } | |
2597 | ||
2598 | /* This insn can't go into a delay slot. */ | |
2599 | lose = 1; | |
d2137327 | 2600 | mark_set_resources (trial, &set, 0, MARK_SRC_DEST_CALL); |
10a15ee4 | 2601 | mark_referenced_resources (trial, &needed, true); |
75040552 | 2602 | |
2603 | /* Ensure we don't put insns between the setting of cc and the comparison | |
2604 | by moving a setting of cc into an earlier delay slot since these insns | |
2605 | could clobber the condition code. */ | |
2606 | set.cc = 1; | |
2607 | ||
2608 | /* If this insn is a register-register copy and the next insn has | |
2609 | a use of our destination, change it to use our source. That way, | |
2610 | it will become a candidate for our delay slot the next time | |
2611 | through this loop. This case occurs commonly in loops that | |
2612 | scan a list. | |
2613 | ||
2614 | We could check for more complex cases than those tested below, | |
2615 | but it doesn't seem worth it. It might also be a good idea to try | |
c571dfae | 2616 | to swap the two insns. That might do better. |
2617 | ||
ad36522f | 2618 | We can't do this if the next insn modifies our destination, because |
2619 | that would make the replacement into the insn invalid. We also can't | |
2620 | do this if it modifies our source, because it might be an earlyclobber | |
2621 | operand. This latter test also prevents updating the contents of | |
973c73e7 | 2622 | a PRE_INC. We also can't do this if there's overlap of source and |
2623 | destination. Overlap may happen for larger-than-register-size modes. */ | |
75040552 | 2624 | |
6d7dc5b9 | 2625 | if (NONJUMP_INSN_P (trial) && GET_CODE (pat) == SET |
8ad4c111 | 2626 | && REG_P (SET_SRC (pat)) |
2627 | && REG_P (SET_DEST (pat)) | |
973c73e7 | 2628 | && !reg_overlap_mentioned_p (SET_DEST (pat), SET_SRC (pat))) |
75040552 | 2629 | { |
bf79ca12 | 2630 | rtx_insn *next = next_nonnote_insn (trial); |
75040552 | 2631 | |
6d7dc5b9 | 2632 | if (next && NONJUMP_INSN_P (next) |
c571dfae | 2633 | && GET_CODE (PATTERN (next)) != USE |
2634 | && ! reg_set_p (SET_DEST (pat), next) | |
ad36522f | 2635 | && ! reg_set_p (SET_SRC (pat), next) |
cdead556 | 2636 | && reg_referenced_p (SET_DEST (pat), PATTERN (next)) |
2637 | && ! modified_in_p (SET_DEST (pat), next)) | |
75040552 | 2638 | validate_replace_rtx (SET_DEST (pat), SET_SRC (pat), next); |
2639 | } | |
2640 | } | |
2641 | ||
2642 | /* If we stopped on a branch insn that has delay slots, see if we can | |
2643 | steal some of the insns in those slots. */ | |
6d7dc5b9 | 2644 | if (trial && NONJUMP_INSN_P (trial) |
75040552 | 2645 | && GET_CODE (PATTERN (trial)) == SEQUENCE |
6d7dc5b9 | 2646 | && JUMP_P (XVECEXP (PATTERN (trial), 0, 0))) |
75040552 | 2647 | { |
575a12f2 | 2648 | rtx_sequence *sequence = as_a <rtx_sequence *> (PATTERN (trial)); |
75040552 | 2649 | /* If this is the `true' thread, we will want to follow the jump, |
2650 | so we can only do this if we have taken everything up to here. */ | |
86236ca9 | 2651 | if (thread_if_true && trial == new_thread) |
9a45115e | 2652 | { |
28cb74c5 | 2653 | steal_delay_list_from_target (insn, condition, sequence, |
2654 | delay_list, &set, &needed, | |
2655 | &opposite_needed, slots_to_fill, | |
2656 | pslots_filled, &must_annul, | |
2657 | &new_thread); | |
9a45115e | 2658 | /* If we owned the thread and are told that it branched |
2659 | elsewhere, make sure we own the thread at the new location. */ | |
2660 | if (own_thread && trial != new_thread) | |
2661 | own_thread = own_thread_p (new_thread, new_thread, 0); | |
2662 | } | |
75040552 | 2663 | else if (! thread_if_true) |
28cb74c5 | 2664 | steal_delay_list_from_fallthrough (insn, condition, sequence, |
2665 | delay_list, &set, &needed, | |
2666 | &opposite_needed, slots_to_fill, | |
2667 | pslots_filled, &must_annul); | |
75040552 | 2668 | } |
2669 | ||
2670 | /* If we haven't found anything for this delay slot and it is very | |
2671 | likely that the branch will be taken, see if the insn at our target | |
99c63f51 | 2672 | increments or decrements a register with an increment that does not |
2673 | depend on the destination register. If so, try to place the opposite | |
75040552 | 2674 | arithmetic insn after the jump insn and put the arithmetic insn in the |
2675 | delay slot. If we can't do this, return. */ | |
28cb74c5 | 2676 | if (delay_list->is_empty () && likely |
4115ac36 | 2677 | && new_thread && !ANY_RETURN_P (new_thread) |
6d7dc5b9 | 2678 | && NONJUMP_INSN_P (new_thread) |
f0421938 | 2679 | && !RTX_FRAME_RELATED_P (new_thread) |
bab1b916 | 2680 | && GET_CODE (PATTERN (new_thread)) != ASM_INPUT |
2681 | && asm_noperands (PATTERN (new_thread)) < 0) | |
75040552 | 2682 | { |
2683 | rtx pat = PATTERN (new_thread); | |
2684 | rtx dest; | |
2685 | rtx src; | |
2686 | ||
c2c03a95 | 2687 | /* We know "new_thread" is an insn due to NONJUMP_INSN_P (new_thread) |
2688 | above. */ | |
2689 | trial = as_a <rtx_insn *> (new_thread); | |
75040552 | 2690 | pat = PATTERN (trial); |
2691 | ||
6d7dc5b9 | 2692 | if (!NONJUMP_INSN_P (trial) |
55427c62 | 2693 | || GET_CODE (pat) != SET |
2694 | || ! eligible_for_delay (insn, 0, trial, flags) | |
2695 | || can_throw_internal (trial)) | |
28cb74c5 | 2696 | return; |
75040552 | 2697 | |
2698 | dest = SET_DEST (pat), src = SET_SRC (pat); | |
2699 | if ((GET_CODE (src) == PLUS || GET_CODE (src) == MINUS) | |
99c63f51 | 2700 | && rtx_equal_p (XEXP (src, 0), dest) |
44382350 | 2701 | && (!FLOAT_MODE_P (GET_MODE (src)) |
2702 | || flag_unsafe_math_optimizations) | |
9e5256ce | 2703 | && ! reg_overlap_mentioned_p (dest, XEXP (src, 1)) |
2704 | && ! side_effects_p (pat)) | |
75040552 | 2705 | { |
2706 | rtx other = XEXP (src, 1); | |
2707 | rtx new_arith; | |
575a12f2 | 2708 | rtx_insn *ninsn; |
75040552 | 2709 | |
2710 | /* If this is a constant adjustment, use the same code with | |
2711 | the negated constant. Otherwise, reverse the sense of the | |
2712 | arithmetic. */ | |
971ba038 | 2713 | if (CONST_INT_P (other)) |
941522d6 | 2714 | new_arith = gen_rtx_fmt_ee (GET_CODE (src), GET_MODE (src), dest, |
2715 | negate_rtx (GET_MODE (src), other)); | |
75040552 | 2716 | else |
941522d6 | 2717 | new_arith = gen_rtx_fmt_ee (GET_CODE (src) == PLUS ? MINUS : PLUS, |
2718 | GET_MODE (src), dest, other); | |
75040552 | 2719 | |
d1f9b275 | 2720 | ninsn = emit_insn_after (gen_rtx_SET (dest, new_arith), insn); |
75040552 | 2721 | |
2722 | if (recog_memoized (ninsn) < 0 | |
e2f730a9 | 2723 | || (extract_insn (ninsn), |
2724 | !constrain_operands (1, get_preferred_alternatives (ninsn)))) | |
75040552 | 2725 | { |
e4bf866d | 2726 | delete_related_insns (ninsn); |
28cb74c5 | 2727 | return; |
75040552 | 2728 | } |
2729 | ||
2730 | if (own_thread) | |
2731 | { | |
3d5c2032 | 2732 | update_block (trial, thread); |
4fef6e7d | 2733 | if (trial == thread) |
2734 | { | |
2735 | thread = next_active_insn (thread); | |
2736 | if (new_thread == trial) | |
2737 | new_thread = thread; | |
2738 | } | |
e4bf866d | 2739 | delete_related_insns (trial); |
75040552 | 2740 | } |
2741 | else | |
2742 | new_thread = next_active_insn (trial); | |
2743 | ||
a9abe1f1 | 2744 | ninsn = own_thread ? trial : copy_delay_slot_insn (trial); |
75040552 | 2745 | if (thread_if_true) |
2746 | INSN_FROM_TARGET_P (ninsn) = 1; | |
2747 | ||
28cb74c5 | 2748 | add_to_delay_list (ninsn, delay_list); |
75040552 | 2749 | (*pslots_filled)++; |
2750 | } | |
2751 | } | |
2752 | ||
28cb74c5 | 2753 | if (!delay_list->is_empty () && must_annul) |
75040552 | 2754 | INSN_ANNULLED_BRANCH_P (insn) = 1; |
2755 | ||
2756 | /* If we are to branch into the middle of this thread, find an appropriate | |
2757 | label or make a new one if none, and redirect INSN to it. If we hit the | |
2758 | end of the function, use the end-of-function label. */ | |
2759 | if (new_thread != thread) | |
2760 | { | |
2761 | rtx label; | |
c7b4d9b2 | 2762 | bool crossing = false; |
75040552 | 2763 | |
04e579b6 | 2764 | gcc_assert (thread_if_true); |
75040552 | 2765 | |
9cb2517e | 2766 | if (new_thread && simplejump_or_return_p (new_thread) |
c80ad736 | 2767 | && redirect_with_delay_list_safe_p (insn, |
2768 | JUMP_LABEL (new_thread), | |
28cb74c5 | 2769 | *delay_list)) |
c2c03a95 | 2770 | new_thread = follow_jumps (JUMP_LABEL (new_thread), insn, |
575a12f2 | 2771 | &crossing); |
75040552 | 2772 | |
4115ac36 | 2773 | if (ANY_RETURN_P (new_thread)) |
9cb2517e | 2774 | label = find_end_label (new_thread); |
6d7dc5b9 | 2775 | else if (LABEL_P (new_thread)) |
75040552 | 2776 | label = new_thread; |
2777 | else | |
c2c03a95 | 2778 | label = get_label_before (as_a <rtx_insn *> (new_thread), |
2779 | JUMP_LABEL (insn)); | |
75040552 | 2780 | |
920d6e22 | 2781 | if (label) |
c7b4d9b2 | 2782 | { |
2783 | reorg_redirect_jump (insn, label); | |
2784 | if (crossing) | |
8f869004 | 2785 | CROSSING_JUMP_P (insn) = 1; |
c7b4d9b2 | 2786 | } |
75040552 | 2787 | } |
75040552 | 2788 | } |
2789 | \f | |
2790 | /* Make another attempt to find insns to place in delay slots. | |
2791 | ||
2792 | We previously looked for insns located in front of the delay insn | |
2793 | and, for non-jump delay insns, located behind the delay insn. | |
2794 | ||
2795 | Here only try to schedule jump insns and try to move insns from either | |
2796 | the target or the following insns into the delay slot. If annulling is | |
2797 | supported, we will be likely to do this. Otherwise, we can do this only | |
2798 | if safe. */ | |
2799 | ||
2800 | static void | |
3ad4992f | 2801 | fill_eager_delay_slots (void) |
75040552 | 2802 | { |
575a12f2 | 2803 | rtx_insn *insn; |
19cb6b50 | 2804 | int i; |
75040552 | 2805 | int num_unfilled_slots = unfilled_slots_next - unfilled_slots_base; |
2806 | ||
2807 | for (i = 0; i < num_unfilled_slots; i++) | |
2808 | { | |
2809 | rtx condition; | |
c2c03a95 | 2810 | rtx target_label, insn_at_target; |
2811 | rtx_insn *fallthrough_insn; | |
28cb74c5 | 2812 | auto_vec<rtx_insn *, 5> delay_list; |
f9a00e9e | 2813 | rtx_jump_insn *jump_insn; |
75040552 | 2814 | int own_target; |
2815 | int own_fallthrough; | |
2816 | int prediction, slots_to_fill, slots_filled; | |
2817 | ||
2818 | insn = unfilled_slots_base[i]; | |
2819 | if (insn == 0 | |
dd1286fb | 2820 | || insn->deleted () |
f9a00e9e | 2821 | || ! (jump_insn = dyn_cast <rtx_jump_insn *> (insn)) |
2822 | || ! (condjump_p (jump_insn) || condjump_in_parallel_p (jump_insn))) | |
75040552 | 2823 | continue; |
2824 | ||
f9a00e9e | 2825 | slots_to_fill = num_delay_slots (jump_insn); |
a51cb8eb | 2826 | /* Some machine description have defined instructions to have |
2827 | delay slots only in certain circumstances which may depend on | |
2828 | nearby insns (which change due to reorg's actions). | |
2829 | ||
3ad4992f | 2830 | For example, the PA port normally has delay slots for unconditional |
a51cb8eb | 2831 | jumps. |
2832 | ||
2833 | However, the PA port claims such jumps do not have a delay slot | |
2834 | if they are immediate successors of certain CALL_INSNs. This | |
2835 | allows the port to favor filling the delay slot of the call with | |
2836 | the unconditional jump. */ | |
75040552 | 2837 | if (slots_to_fill == 0) |
7014838c | 2838 | continue; |
75040552 | 2839 | |
2840 | slots_filled = 0; | |
f9a00e9e | 2841 | target_label = JUMP_LABEL (jump_insn); |
2842 | condition = get_branch_condition (jump_insn, target_label); | |
75040552 | 2843 | |
2844 | if (condition == 0) | |
2845 | continue; | |
2846 | ||
b090827b | 2847 | /* Get the next active fallthrough and target insns and see if we own |
75040552 | 2848 | them. Then see whether the branch is likely true. We don't need |
2849 | to do a lot of this for unconditional branches. */ | |
2850 | ||
4115ac36 | 2851 | insn_at_target = first_active_target_insn (target_label); |
75040552 | 2852 | own_target = own_thread_p (target_label, target_label, 0); |
2853 | ||
2854 | if (condition == const_true_rtx) | |
2855 | { | |
2856 | own_fallthrough = 0; | |
2857 | fallthrough_insn = 0; | |
2858 | prediction = 2; | |
2859 | } | |
2860 | else | |
2861 | { | |
f9a00e9e | 2862 | fallthrough_insn = next_active_insn (jump_insn); |
2863 | own_fallthrough = own_thread_p (NEXT_INSN (jump_insn), NULL_RTX, 1); | |
2864 | prediction = mostly_true_jump (jump_insn); | |
75040552 | 2865 | } |
2866 | ||
2867 | /* If this insn is expected to branch, first try to get insns from our | |
21b80b12 | 2868 | target, then our fallthrough insns. If it is not expected to branch, |
75040552 | 2869 | try the other order. */ |
2870 | ||
ea727872 | 2871 | if (prediction > 0) |
75040552 | 2872 | { |
28cb74c5 | 2873 | fill_slots_from_thread (jump_insn, condition, insn_at_target, |
2874 | fallthrough_insn, prediction == 2, 1, | |
2875 | own_target, | |
2876 | slots_to_fill, &slots_filled, &delay_list); | |
75040552 | 2877 | |
28cb74c5 | 2878 | if (delay_list.is_empty () && own_fallthrough) |
75040552 | 2879 | { |
2880 | /* Even though we didn't find anything for delay slots, | |
2881 | we might have found a redundant insn which we deleted | |
2882 | from the thread that was filled. So we have to recompute | |
2883 | the next insn at the target. */ | |
f9a00e9e | 2884 | target_label = JUMP_LABEL (jump_insn); |
4115ac36 | 2885 | insn_at_target = first_active_target_insn (target_label); |
75040552 | 2886 | |
28cb74c5 | 2887 | fill_slots_from_thread (jump_insn, condition, fallthrough_insn, |
2888 | insn_at_target, 0, 0, own_fallthrough, | |
2889 | slots_to_fill, &slots_filled, | |
2890 | &delay_list); | |
75040552 | 2891 | } |
2892 | } | |
2893 | else | |
2894 | { | |
2895 | if (own_fallthrough) | |
28cb74c5 | 2896 | fill_slots_from_thread (jump_insn, condition, fallthrough_insn, |
2897 | insn_at_target, 0, 0, own_fallthrough, | |
2898 | slots_to_fill, &slots_filled, &delay_list); | |
2899 | ||
2900 | if (delay_list.is_empty ()) | |
2901 | fill_slots_from_thread (jump_insn, condition, insn_at_target, | |
2902 | next_active_insn (insn), 0, 1, own_target, | |
2903 | slots_to_fill, &slots_filled, &delay_list); | |
75040552 | 2904 | } |
2905 | ||
28cb74c5 | 2906 | if (!delay_list.is_empty ()) |
75040552 | 2907 | unfilled_slots_base[i] |
f9a00e9e | 2908 | = emit_delay_sequence (jump_insn, delay_list, slots_filled); |
75040552 | 2909 | |
2910 | if (slots_to_fill == slots_filled) | |
2911 | unfilled_slots_base[i] = 0; | |
2912 | ||
2913 | note_delay_statistics (slots_filled, 1); | |
2914 | } | |
2915 | } | |
e3766402 | 2916 | \f |
2917 | static void delete_computation (rtx insn); | |
2918 | ||
2919 | /* Recursively delete prior insns that compute the value (used only by INSN | |
2920 | which the caller is deleting) stored in the register mentioned by NOTE | |
2921 | which is a REG_DEAD note associated with INSN. */ | |
2922 | ||
2923 | static void | |
2924 | delete_prior_computation (rtx note, rtx insn) | |
2925 | { | |
2926 | rtx our_prev; | |
2927 | rtx reg = XEXP (note, 0); | |
2928 | ||
2929 | for (our_prev = prev_nonnote_insn (insn); | |
2930 | our_prev && (NONJUMP_INSN_P (our_prev) | |
2931 | || CALL_P (our_prev)); | |
2932 | our_prev = prev_nonnote_insn (our_prev)) | |
2933 | { | |
2934 | rtx pat = PATTERN (our_prev); | |
2935 | ||
2936 | /* If we reach a CALL which is not calling a const function | |
2937 | or the callee pops the arguments, then give up. */ | |
2938 | if (CALL_P (our_prev) | |
9c2a0c05 | 2939 | && (! RTL_CONST_CALL_P (our_prev) |
e3766402 | 2940 | || GET_CODE (pat) != SET || GET_CODE (SET_SRC (pat)) != CALL)) |
2941 | break; | |
2942 | ||
2943 | /* If we reach a SEQUENCE, it is too complex to try to | |
2944 | do anything with it, so give up. We can be run during | |
2945 | and after reorg, so SEQUENCE rtl can legitimately show | |
2946 | up here. */ | |
2947 | if (GET_CODE (pat) == SEQUENCE) | |
2948 | break; | |
2949 | ||
2950 | if (GET_CODE (pat) == USE | |
2951 | && NONJUMP_INSN_P (XEXP (pat, 0))) | |
2952 | /* reorg creates USEs that look like this. We leave them | |
2953 | alone because reorg needs them for its own purposes. */ | |
2954 | break; | |
2955 | ||
2956 | if (reg_set_p (reg, pat)) | |
2957 | { | |
2958 | if (side_effects_p (pat) && !CALL_P (our_prev)) | |
2959 | break; | |
2960 | ||
2961 | if (GET_CODE (pat) == PARALLEL) | |
2962 | { | |
2963 | /* If we find a SET of something else, we can't | |
2964 | delete the insn. */ | |
2965 | ||
2966 | int i; | |
2967 | ||
2968 | for (i = 0; i < XVECLEN (pat, 0); i++) | |
2969 | { | |
2970 | rtx part = XVECEXP (pat, 0, i); | |
2971 | ||
2972 | if (GET_CODE (part) == SET | |
2973 | && SET_DEST (part) != reg) | |
2974 | break; | |
2975 | } | |
2976 | ||
2977 | if (i == XVECLEN (pat, 0)) | |
2978 | delete_computation (our_prev); | |
2979 | } | |
2980 | else if (GET_CODE (pat) == SET | |
2981 | && REG_P (SET_DEST (pat))) | |
2982 | { | |
2983 | int dest_regno = REGNO (SET_DEST (pat)); | |
a2c6f0b7 | 2984 | int dest_endregno = END_REGNO (SET_DEST (pat)); |
e3766402 | 2985 | int regno = REGNO (reg); |
a2c6f0b7 | 2986 | int endregno = END_REGNO (reg); |
e3766402 | 2987 | |
2988 | if (dest_regno >= regno | |
2989 | && dest_endregno <= endregno) | |
2990 | delete_computation (our_prev); | |
2991 | ||
2992 | /* We may have a multi-word hard register and some, but not | |
2993 | all, of the words of the register are needed in subsequent | |
2994 | insns. Write REG_UNUSED notes for those parts that were not | |
2995 | needed. */ | |
2996 | else if (dest_regno <= regno | |
2997 | && dest_endregno >= endregno) | |
2998 | { | |
2999 | int i; | |
3000 | ||
a1ddb869 | 3001 | add_reg_note (our_prev, REG_UNUSED, reg); |
e3766402 | 3002 | |
3003 | for (i = dest_regno; i < dest_endregno; i++) | |
3004 | if (! find_regno_note (our_prev, REG_UNUSED, i)) | |
3005 | break; | |
3006 | ||
3007 | if (i == dest_endregno) | |
3008 | delete_computation (our_prev); | |
3009 | } | |
3010 | } | |
3011 | ||
3012 | break; | |
3013 | } | |
3014 | ||
3015 | /* If PAT references the register that dies here, it is an | |
3016 | additional use. Hence any prior SET isn't dead. However, this | |
3017 | insn becomes the new place for the REG_DEAD note. */ | |
3018 | if (reg_overlap_mentioned_p (reg, pat)) | |
3019 | { | |
3020 | XEXP (note, 1) = REG_NOTES (our_prev); | |
3021 | REG_NOTES (our_prev) = note; | |
3022 | break; | |
3023 | } | |
3024 | } | |
3025 | } | |
3026 | ||
3027 | /* Delete INSN and recursively delete insns that compute values used only | |
3028 | by INSN. This uses the REG_DEAD notes computed during flow analysis. | |
e3766402 | 3029 | |
72c0c58f | 3030 | Look at all our REG_DEAD notes. If a previous insn does nothing other |
3031 | than set a register that dies in this insn, we can delete that insn | |
3032 | as well. | |
e3766402 | 3033 | |
3034 | On machines with CC0, if CC0 is used in this insn, we may be able to | |
3035 | delete the insn that set it. */ | |
3036 | ||
3037 | static void | |
3038 | delete_computation (rtx insn) | |
3039 | { | |
3040 | rtx note, next; | |
3041 | ||
ff900b8e | 3042 | if (HAVE_cc0 && reg_referenced_p (cc0_rtx, PATTERN (insn))) |
e3766402 | 3043 | { |
bf79ca12 | 3044 | rtx_insn *prev = prev_nonnote_insn (insn); |
e3766402 | 3045 | /* We assume that at this stage |
3046 | CC's are always set explicitly | |
3047 | and always immediately before the jump that | |
3048 | will use them. So if the previous insn | |
3049 | exists to set the CC's, delete it | |
3050 | (unless it performs auto-increments, etc.). */ | |
3051 | if (prev && NONJUMP_INSN_P (prev) | |
3052 | && sets_cc0_p (PATTERN (prev))) | |
3053 | { | |
3054 | if (sets_cc0_p (PATTERN (prev)) > 0 | |
3055 | && ! side_effects_p (PATTERN (prev))) | |
3056 | delete_computation (prev); | |
3057 | else | |
3058 | /* Otherwise, show that cc0 won't be used. */ | |
a1ddb869 | 3059 | add_reg_note (prev, REG_UNUSED, cc0_rtx); |
e3766402 | 3060 | } |
3061 | } | |
e3766402 | 3062 | |
3063 | for (note = REG_NOTES (insn); note; note = next) | |
3064 | { | |
3065 | next = XEXP (note, 1); | |
3066 | ||
3067 | if (REG_NOTE_KIND (note) != REG_DEAD | |
3068 | /* Verify that the REG_NOTE is legitimate. */ | |
3069 | || !REG_P (XEXP (note, 0))) | |
3070 | continue; | |
3071 | ||
3072 | delete_prior_computation (note, insn); | |
3073 | } | |
3074 | ||
3075 | delete_related_insns (insn); | |
3076 | } | |
3077 | ||
3078 | /* If all INSN does is set the pc, delete it, | |
3079 | and delete the insn that set the condition codes for it | |
3080 | if that's what the previous thing was. */ | |
3081 | ||
3082 | static void | |
50fc2d35 | 3083 | delete_jump (rtx_insn *insn) |
e3766402 | 3084 | { |
3085 | rtx set = single_set (insn); | |
3086 | ||
3087 | if (set && GET_CODE (SET_DEST (set)) == PC) | |
3088 | delete_computation (insn); | |
3089 | } | |
3090 | ||
91a55c11 | 3091 | static rtx_insn * |
fa1ad02f | 3092 | label_before_next_insn (rtx x, rtx scan_limit) |
3093 | { | |
91a55c11 | 3094 | rtx_insn *insn = next_active_insn (x); |
fa1ad02f | 3095 | while (insn) |
3096 | { | |
3097 | insn = PREV_INSN (insn); | |
3098 | if (insn == scan_limit || insn == NULL_RTX) | |
91a55c11 | 3099 | return NULL; |
fa1ad02f | 3100 | if (LABEL_P (insn)) |
3101 | break; | |
3102 | } | |
3103 | return insn; | |
3104 | } | |
3105 | ||
27e4242f | 3106 | /* Return TRUE if there is a NOTE_INSN_SWITCH_TEXT_SECTIONS note in between |
3107 | BEG and END. */ | |
3108 | ||
3109 | static bool | |
3110 | switch_text_sections_between_p (const rtx_insn *beg, const rtx_insn *end) | |
3111 | { | |
3112 | const rtx_insn *p; | |
3113 | for (p = beg; p != end; p = NEXT_INSN (p)) | |
3114 | if (NOTE_P (p) && NOTE_KIND (p) == NOTE_INSN_SWITCH_TEXT_SECTIONS) | |
3115 | return true; | |
3116 | return false; | |
3117 | } | |
3118 | ||
75040552 | 3119 | \f |
3120 | /* Once we have tried two ways to fill a delay slot, make a pass over the | |
3121 | code to try to improve the results and to do such things as more jump | |
3122 | threading. */ | |
3123 | ||
3124 | static void | |
575a12f2 | 3125 | relax_delay_slots (rtx_insn *first) |
75040552 | 3126 | { |
575a12f2 | 3127 | rtx_insn *insn, *next; |
3128 | rtx_sequence *pat; | |
c2c03a95 | 3129 | rtx trial; |
3130 | rtx_insn *delay_insn; | |
3131 | rtx target_label; | |
75040552 | 3132 | |
3133 | /* Look at every JUMP_INSN and see if we can improve it. */ | |
3134 | for (insn = first; insn; insn = next) | |
3135 | { | |
91a55c11 | 3136 | rtx_insn *other; |
c7b4d9b2 | 3137 | bool crossing; |
75040552 | 3138 | |
3139 | next = next_active_insn (insn); | |
3140 | ||
3141 | /* If this is a jump insn, see if it now jumps to a jump, jumps to | |
3142 | the next insn, or jumps to a label that is not the last of a | |
3143 | group of consecutive labels. */ | |
f9a00e9e | 3144 | if (is_a <rtx_jump_insn *> (insn) |
4fbe8fa7 | 3145 | && (condjump_p (insn) || condjump_in_parallel_p (insn)) |
c2c03a95 | 3146 | && !ANY_RETURN_P (target_label = JUMP_LABEL (insn))) |
75040552 | 3147 | { |
f9a00e9e | 3148 | rtx_jump_insn *jump_insn = as_a <rtx_jump_insn *> (insn); |
c7b4d9b2 | 3149 | target_label |
f9a00e9e | 3150 | = skip_consecutive_labels (follow_jumps (target_label, jump_insn, |
c7b4d9b2 | 3151 | &crossing)); |
4115ac36 | 3152 | if (ANY_RETURN_P (target_label)) |
9cb2517e | 3153 | target_label = find_end_label (target_label); |
eb521e88 | 3154 | |
920d6e22 | 3155 | if (target_label && next_active_insn (target_label) == next |
f9a00e9e | 3156 | && ! condjump_in_parallel_p (jump_insn) |
3157 | && ! (next && switch_text_sections_between_p (jump_insn, next))) | |
75040552 | 3158 | { |
f9a00e9e | 3159 | delete_jump (jump_insn); |
75040552 | 3160 | continue; |
3161 | } | |
3162 | ||
f9a00e9e | 3163 | if (target_label && target_label != JUMP_LABEL (jump_insn)) |
c7b4d9b2 | 3164 | { |
f9a00e9e | 3165 | reorg_redirect_jump (jump_insn, target_label); |
c7b4d9b2 | 3166 | if (crossing) |
f9a00e9e | 3167 | CROSSING_JUMP_P (jump_insn) = 1; |
c7b4d9b2 | 3168 | } |
75040552 | 3169 | |
d0003daa | 3170 | /* See if this jump conditionally branches around an unconditional |
3171 | jump. If so, invert this jump and point it to the target of the | |
27e4242f | 3172 | second jump. Check if it's possible on the target. */ |
9cb2517e | 3173 | if (next && simplejump_or_return_p (next) |
f9a00e9e | 3174 | && any_condjump_p (jump_insn) |
920d6e22 | 3175 | && target_label |
75040552 | 3176 | && next_active_insn (target_label) == next_active_insn (next) |
f9a00e9e | 3177 | && no_labels_between_p (jump_insn, next) |
3178 | && targetm.can_follow_jump (jump_insn, next)) | |
75040552 | 3179 | { |
3180 | rtx label = JUMP_LABEL (next); | |
3181 | ||
3182 | /* Be careful how we do this to avoid deleting code or | |
3183 | labels that are momentarily dead. See similar optimization | |
3184 | in jump.c. | |
3185 | ||
3186 | We also need to ensure we properly handle the case when | |
3187 | invert_jump fails. */ | |
3188 | ||
3189 | ++LABEL_NUSES (target_label); | |
4115ac36 | 3190 | if (!ANY_RETURN_P (label)) |
75040552 | 3191 | ++LABEL_NUSES (label); |
3192 | ||
f9a00e9e | 3193 | if (invert_jump (jump_insn, label, 1)) |
75040552 | 3194 | { |
e4bf866d | 3195 | delete_related_insns (next); |
f9a00e9e | 3196 | next = jump_insn; |
75040552 | 3197 | } |
3198 | ||
4115ac36 | 3199 | if (!ANY_RETURN_P (label)) |
75040552 | 3200 | --LABEL_NUSES (label); |
3201 | ||
3202 | if (--LABEL_NUSES (target_label) == 0) | |
e4bf866d | 3203 | delete_related_insns (target_label); |
75040552 | 3204 | |
3205 | continue; | |
3206 | } | |
3207 | } | |
875b3f3b | 3208 | |
75040552 | 3209 | /* If this is an unconditional jump and the previous insn is a |
3210 | conditional jump, try reversing the condition of the previous | |
3211 | insn and swapping our targets. The next pass might be able to | |
3212 | fill the slots. | |
3213 | ||
3214 | Don't do this if we expect the conditional branch to be true, because | |
3215 | we would then be making the more common case longer. */ | |
3216 | ||
9cb2517e | 3217 | if (simplejump_or_return_p (insn) |
75040552 | 3218 | && (other = prev_active_insn (insn)) != 0 |
d0003daa | 3219 | && any_condjump_p (other) |
75040552 | 3220 | && no_labels_between_p (other, insn) |
9ddd9ef9 | 3221 | && 0 > mostly_true_jump (other)) |
75040552 | 3222 | { |
3223 | rtx other_target = JUMP_LABEL (other); | |
c2c03a95 | 3224 | target_label = JUMP_LABEL (insn); |
75040552 | 3225 | |
f9a00e9e | 3226 | if (invert_jump (as_a <rtx_jump_insn *> (other), target_label, 0)) |
3227 | reorg_redirect_jump (as_a <rtx_jump_insn *> (insn), other_target); | |
75040552 | 3228 | } |
3229 | ||
c2d94248 | 3230 | /* Now look only at cases where we have a filled delay slot. */ |
3231 | if (!NONJUMP_INSN_P (insn) || GET_CODE (PATTERN (insn)) != SEQUENCE) | |
75040552 | 3232 | continue; |
3233 | ||
575a12f2 | 3234 | pat = as_a <rtx_sequence *> (PATTERN (insn)); |
3235 | delay_insn = pat->insn (0); | |
75040552 | 3236 | |
3237 | /* See if the first insn in the delay slot is redundant with some | |
3238 | previous insn. Remove it from the delay slot if so; then set up | |
3239 | to reprocess this insn. */ | |
28cb74c5 | 3240 | if (redundant_insn (pat->insn (1), delay_insn, vNULL)) |
75040552 | 3241 | { |
575a12f2 | 3242 | update_block (pat->insn (1), insn); |
3243 | delete_from_delay_slot (pat->insn (1)); | |
75040552 | 3244 | next = prev_active_insn (next); |
3245 | continue; | |
3246 | } | |
3247 | ||
757eb99e | 3248 | /* See if we have a RETURN insn with a filled delay slot followed |
3249 | by a RETURN insn with an unfilled a delay slot. If so, we can delete | |
3927afe0 | 3250 | the first RETURN (but not its delay insn). This gives the same |
757eb99e | 3251 | effect in fewer instructions. |
3252 | ||
3253 | Only do so if optimizing for size since this results in slower, but | |
3254 | smaller code. */ | |
0bfd8d5c | 3255 | if (optimize_function_for_size_p (cfun) |
9cb2517e | 3256 | && ANY_RETURN_P (PATTERN (delay_insn)) |
757eb99e | 3257 | && next |
6d7dc5b9 | 3258 | && JUMP_P (next) |
9cb2517e | 3259 | && PATTERN (next) == PATTERN (delay_insn)) |
757eb99e | 3260 | { |
5e9c670f | 3261 | rtx_insn *after; |
757eb99e | 3262 | int i; |
3263 | ||
3264 | /* Delete the RETURN and just execute the delay list insns. | |
3265 | ||
3266 | We do this by deleting the INSN containing the SEQUENCE, then | |
3267 | re-emitting the insns separately, and then deleting the RETURN. | |
3268 | This allows the count of the jump target to be properly | |
bd405dcf | 3269 | decremented. |
757eb99e | 3270 | |
bd405dcf | 3271 | Note that we need to change the INSN_UID of the re-emitted insns |
3272 | since it is used to hash the insns for mark_target_live_regs and | |
3273 | the re-emitted insns will no longer be wrapped up in a SEQUENCE. | |
3274 | ||
3275 | Clear the from target bit, since these insns are no longer | |
757eb99e | 3276 | in delay slots. */ |
3277 | for (i = 0; i < XVECLEN (pat, 0); i++) | |
3278 | INSN_FROM_TARGET_P (XVECEXP (pat, 0, i)) = 0; | |
3279 | ||
3280 | trial = PREV_INSN (insn); | |
e4bf866d | 3281 | delete_related_insns (insn); |
04e579b6 | 3282 | gcc_assert (GET_CODE (pat) == SEQUENCE); |
bd405dcf | 3283 | add_insn_after (delay_insn, trial, NULL); |
3284 | after = delay_insn; | |
5e9c670f | 3285 | for (i = 1; i < pat->len (); i++) |
3286 | after = emit_copy_of_insn_after (pat->insn (i), after); | |
757eb99e | 3287 | delete_scheduled_jump (delay_insn); |
3288 | continue; | |
3289 | } | |
3290 | ||
75040552 | 3291 | /* Now look only at the cases where we have a filled JUMP_INSN. */ |
f9a00e9e | 3292 | rtx_jump_insn *delay_jump_insn = |
3293 | dyn_cast <rtx_jump_insn *> (delay_insn); | |
3294 | if (! delay_jump_insn || !(condjump_p (delay_jump_insn) | |
3295 | || condjump_in_parallel_p (delay_jump_insn))) | |
75040552 | 3296 | continue; |
3297 | ||
f9a00e9e | 3298 | target_label = JUMP_LABEL (delay_jump_insn); |
9cb2517e | 3299 | if (target_label && ANY_RETURN_P (target_label)) |
3300 | continue; | |
75040552 | 3301 | |
9cb2517e | 3302 | /* If this jump goes to another unconditional jump, thread it, but |
3303 | don't convert a jump into a RETURN here. */ | |
f9a00e9e | 3304 | trial = skip_consecutive_labels (follow_jumps (target_label, |
3305 | delay_jump_insn, | |
c7b4d9b2 | 3306 | &crossing)); |
9cb2517e | 3307 | if (ANY_RETURN_P (trial)) |
3308 | trial = find_end_label (trial); | |
75040552 | 3309 | |
9cb2517e | 3310 | if (trial && trial != target_label |
f9a00e9e | 3311 | && redirect_with_delay_slots_safe_p (delay_jump_insn, trial, insn)) |
9cb2517e | 3312 | { |
f9a00e9e | 3313 | reorg_redirect_jump (delay_jump_insn, trial); |
9cb2517e | 3314 | target_label = trial; |
c7b4d9b2 | 3315 | if (crossing) |
8f869004 | 3316 | CROSSING_JUMP_P (insn) = 1; |
9cb2517e | 3317 | } |
80bda468 | 3318 | |
9cb2517e | 3319 | /* If the first insn at TARGET_LABEL is redundant with a previous |
3320 | insn, redirect the jump to the following insn and process again. | |
3321 | We use next_real_insn instead of next_active_insn so we | |
3322 | don't skip USE-markers, or we'll end up with incorrect | |
3323 | liveness info. */ | |
3324 | trial = next_real_insn (target_label); | |
3325 | if (trial && GET_CODE (PATTERN (trial)) != SEQUENCE | |
28cb74c5 | 3326 | && redundant_insn (trial, insn, vNULL) |
9cb2517e | 3327 | && ! can_throw_internal (trial)) |
3328 | { | |
3329 | /* Figure out where to emit the special USE insn so we don't | |
3330 | later incorrectly compute register live/death info. */ | |
91a55c11 | 3331 | rtx_insn *tmp = next_active_insn (trial); |
9cb2517e | 3332 | if (tmp == 0) |
3333 | tmp = find_end_label (simple_return_rtx); | |
80bda468 | 3334 | |
9cb2517e | 3335 | if (tmp) |
3336 | { | |
c2c03a95 | 3337 | /* Insert the special USE insn and update dataflow info. |
3338 | We know "trial" is an insn here as it is the output of | |
3339 | next_real_insn () above. */ | |
3340 | update_block (as_a <rtx_insn *> (trial), tmp); | |
9cb2517e | 3341 | |
3342 | /* Now emit a label before the special USE insn, and | |
3343 | redirect our jump to the new label. */ | |
14e08599 | 3344 | target_label = get_label_before (PREV_INSN (tmp), target_label); |
f9a00e9e | 3345 | reorg_redirect_jump (delay_jump_insn, target_label); |
9cb2517e | 3346 | next = insn; |
3347 | continue; | |
75040552 | 3348 | } |
9cb2517e | 3349 | } |
75040552 | 3350 | |
9cb2517e | 3351 | /* Similarly, if it is an unconditional jump with one insn in its |
3352 | delay list and that insn is redundant, thread the jump. */ | |
d77c5bc0 | 3353 | rtx_sequence *trial_seq = |
3354 | trial ? dyn_cast <rtx_sequence *> (PATTERN (trial)) : NULL; | |
3355 | if (trial_seq | |
3356 | && trial_seq->len () == 2 | |
3357 | && JUMP_P (trial_seq->insn (0)) | |
3358 | && simplejump_or_return_p (trial_seq->insn (0)) | |
28cb74c5 | 3359 | && redundant_insn (trial_seq->insn (1), insn, vNULL)) |
9cb2517e | 3360 | { |
c2c03a95 | 3361 | target_label = JUMP_LABEL (trial_seq->insn (0)); |
9cb2517e | 3362 | if (ANY_RETURN_P (target_label)) |
3363 | target_label = find_end_label (target_label); | |
3364 | ||
3365 | if (target_label | |
f9a00e9e | 3366 | && redirect_with_delay_slots_safe_p (delay_jump_insn, |
3367 | target_label, insn)) | |
75040552 | 3368 | { |
575a12f2 | 3369 | update_block (trial_seq->insn (1), insn); |
f9a00e9e | 3370 | reorg_redirect_jump (delay_jump_insn, target_label); |
9cb2517e | 3371 | next = insn; |
3372 | continue; | |
75040552 | 3373 | } |
3374 | } | |
3375 | ||
9971f647 | 3376 | /* See if we have a simple (conditional) jump that is useless. */ |
f9a00e9e | 3377 | if (! INSN_ANNULLED_BRANCH_P (delay_jump_insn) |
3378 | && ! condjump_in_parallel_p (delay_jump_insn) | |
9971f647 | 3379 | && prev_active_insn (target_label) == insn |
3380 | && ! BARRIER_P (prev_nonnote_insn (target_label)) | |
75040552 | 3381 | /* If the last insn in the delay slot sets CC0 for some insn, |
3382 | various code assumes that it is in a delay slot. We could | |
3383 | put it back where it belonged and delete the register notes, | |
4bbea254 | 3384 | but it doesn't seem worthwhile in this uncommon case. */ |
0e9d0aeb | 3385 | && (!HAVE_cc0 |
3386 | || ! find_reg_note (XVECEXP (pat, 0, XVECLEN (pat, 0) - 1), | |
3387 | REG_CC_USER, NULL_RTX))) | |
75040552 | 3388 | { |
5e9c670f | 3389 | rtx_insn *after; |
c2cbb9e8 | 3390 | int i; |
3391 | ||
75040552 | 3392 | /* All this insn does is execute its delay list and jump to the |
3393 | following insn. So delete the jump and just execute the delay | |
3394 | list insns. | |
3395 | ||
3396 | We do this by deleting the INSN containing the SEQUENCE, then | |
3397 | re-emitting the insns separately, and then deleting the jump. | |
3398 | This allows the count of the jump target to be properly | |
bd405dcf | 3399 | decremented. |
75040552 | 3400 | |
bd405dcf | 3401 | Note that we need to change the INSN_UID of the re-emitted insns |
3402 | since it is used to hash the insns for mark_target_live_regs and | |
3403 | the re-emitted insns will no longer be wrapped up in a SEQUENCE. | |
3404 | ||
3405 | Clear the from target bit, since these insns are no longer | |
c2cbb9e8 | 3406 | in delay slots. */ |
3407 | for (i = 0; i < XVECLEN (pat, 0); i++) | |
3408 | INSN_FROM_TARGET_P (XVECEXP (pat, 0, i)) = 0; | |
3409 | ||
75040552 | 3410 | trial = PREV_INSN (insn); |
e4bf866d | 3411 | delete_related_insns (insn); |
04e579b6 | 3412 | gcc_assert (GET_CODE (pat) == SEQUENCE); |
f9a00e9e | 3413 | add_insn_after (delay_jump_insn, trial, NULL); |
3414 | after = delay_jump_insn; | |
5e9c670f | 3415 | for (i = 1; i < pat->len (); i++) |
3416 | after = emit_copy_of_insn_after (pat->insn (i), after); | |
f9a00e9e | 3417 | delete_scheduled_jump (delay_jump_insn); |
75040552 | 3418 | continue; |
3419 | } | |
3420 | ||
b9bec8e4 | 3421 | /* See if this is an unconditional jump around a single insn which is |
3422 | identical to the one in its delay slot. In this case, we can just | |
3423 | delete the branch and the insn in its delay slot. */ | |
6d7dc5b9 | 3424 | if (next && NONJUMP_INSN_P (next) |
fa1ad02f | 3425 | && label_before_next_insn (next, insn) == target_label |
b9bec8e4 | 3426 | && simplejump_p (insn) |
3427 | && XVECLEN (pat, 0) == 2 | |
575a12f2 | 3428 | && rtx_equal_p (PATTERN (next), PATTERN (pat->insn (1)))) |
b9bec8e4 | 3429 | { |
e4bf866d | 3430 | delete_related_insns (insn); |
b9bec8e4 | 3431 | continue; |
3432 | } | |
3433 | ||
8ce4be4f | 3434 | /* See if this jump (with its delay slots) conditionally branches |
3435 | around an unconditional jump (without delay slots). If so, invert | |
3436 | this jump and point it to the target of the second jump. We cannot | |
3437 | do this for annulled jumps, though. Again, don't convert a jump to | |
3438 | a RETURN here. */ | |
f9a00e9e | 3439 | if (! INSN_ANNULLED_BRANCH_P (delay_jump_insn) |
3440 | && any_condjump_p (delay_jump_insn) | |
9cb2517e | 3441 | && next && simplejump_or_return_p (next) |
75040552 | 3442 | && next_active_insn (target_label) == next_active_insn (next) |
3443 | && no_labels_between_p (insn, next)) | |
3444 | { | |
3445 | rtx label = JUMP_LABEL (next); | |
f9a00e9e | 3446 | rtx old_label = JUMP_LABEL (delay_jump_insn); |
75040552 | 3447 | |
4115ac36 | 3448 | if (ANY_RETURN_P (label)) |
9cb2517e | 3449 | label = find_end_label (label); |
75040552 | 3450 | |
f636b0a9 | 3451 | /* find_end_label can generate a new label. Check this first. */ |
920d6e22 | 3452 | if (label |
3453 | && no_labels_between_p (insn, next) | |
f9a00e9e | 3454 | && redirect_with_delay_slots_safe_p (delay_jump_insn, |
3455 | label, insn)) | |
75040552 | 3456 | { |
1ee06916 | 3457 | /* Be careful how we do this to avoid deleting code or labels |
3458 | that are momentarily dead. See similar optimization in | |
3459 | jump.c */ | |
3460 | if (old_label) | |
3461 | ++LABEL_NUSES (old_label); | |
75040552 | 3462 | |
f9a00e9e | 3463 | if (invert_jump (delay_jump_insn, label, 1)) |
1ee06916 | 3464 | { |
e6812ef8 | 3465 | int i; |
3466 | ||
3467 | /* Must update the INSN_FROM_TARGET_P bits now that | |
3468 | the branch is reversed, so that mark_target_live_regs | |
3469 | will handle the delay slot insn correctly. */ | |
3470 | for (i = 1; i < XVECLEN (PATTERN (insn), 0); i++) | |
3471 | { | |
3472 | rtx slot = XVECEXP (PATTERN (insn), 0, i); | |
3473 | INSN_FROM_TARGET_P (slot) = ! INSN_FROM_TARGET_P (slot); | |
3474 | } | |
3475 | ||
e4bf866d | 3476 | delete_related_insns (next); |
1ee06916 | 3477 | next = insn; |
3478 | } | |
3479 | ||
3480 | if (old_label && --LABEL_NUSES (old_label) == 0) | |
e4bf866d | 3481 | delete_related_insns (old_label); |
1ee06916 | 3482 | continue; |
3483 | } | |
75040552 | 3484 | } |
3485 | ||
3486 | /* If we own the thread opposite the way this insn branches, see if we | |
3487 | can merge its delay slots with following insns. */ | |
575a12f2 | 3488 | if (INSN_FROM_TARGET_P (pat->insn (1)) |
75040552 | 3489 | && own_thread_p (NEXT_INSN (insn), 0, 1)) |
3490 | try_merge_delay_insns (insn, next); | |
575a12f2 | 3491 | else if (! INSN_FROM_TARGET_P (pat->insn (1)) |
75040552 | 3492 | && own_thread_p (target_label, target_label, 0)) |
3493 | try_merge_delay_insns (insn, next_active_insn (target_label)); | |
3494 | ||
3495 | /* If we get here, we haven't deleted INSN. But we may have deleted | |
3496 | NEXT, so recompute it. */ | |
3497 | next = next_active_insn (insn); | |
3498 | } | |
3499 | } | |
3500 | \f | |
75040552 | 3501 | |
3502 | /* Look for filled jumps to the end of function label. We can try to convert | |
3503 | them into RETURN insns if the insns in the delay slot are valid for the | |
3504 | RETURN as well. */ | |
3505 | ||
3506 | static void | |
91a55c11 | 3507 | make_return_insns (rtx_insn *first) |
75040552 | 3508 | { |
91a55c11 | 3509 | rtx_insn *insn; |
f9a00e9e | 3510 | rtx_jump_insn *jump_insn; |
9cb2517e | 3511 | rtx real_return_label = function_return_label; |
3512 | rtx real_simple_return_label = function_simple_return_label; | |
75040552 | 3513 | int slots, i; |
3514 | ||
3515 | /* See if there is a RETURN insn in the function other than the one we | |
3516 | made for END_OF_FUNCTION_LABEL. If so, set up anything we can't change | |
3517 | into a RETURN to jump to it. */ | |
3518 | for (insn = first; insn; insn = NEXT_INSN (insn)) | |
9cb2517e | 3519 | if (JUMP_P (insn) && ANY_RETURN_P (PATTERN (insn))) |
75040552 | 3520 | { |
14e08599 | 3521 | rtx t = get_label_before (insn, NULL_RTX); |
9cb2517e | 3522 | if (PATTERN (insn) == ret_rtx) |
3523 | real_return_label = t; | |
3524 | else | |
3525 | real_simple_return_label = t; | |
75040552 | 3526 | break; |
3527 | } | |
875b3f3b | 3528 | |
75040552 | 3529 | /* Show an extra usage of REAL_RETURN_LABEL so it won't go away if it |
3530 | was equal to END_OF_FUNCTION_LABEL. */ | |
9cb2517e | 3531 | if (real_return_label) |
3532 | LABEL_NUSES (real_return_label)++; | |
3533 | if (real_simple_return_label) | |
3534 | LABEL_NUSES (real_simple_return_label)++; | |
75040552 | 3535 | |
3536 | /* Clear the list of insns to fill so we can use it. */ | |
3537 | obstack_free (&unfilled_slots_obstack, unfilled_firstobj); | |
3538 | ||
3539 | for (insn = first; insn; insn = NEXT_INSN (insn)) | |
3540 | { | |
45c67dee | 3541 | int flags; |
9cb2517e | 3542 | rtx kind, real_label; |
45c67dee | 3543 | |
75040552 | 3544 | /* Only look at filled JUMP_INSNs that go to the end of function |
3545 | label. */ | |
93ee8dfb | 3546 | if (!NONJUMP_INSN_P (insn)) |
9cb2517e | 3547 | continue; |
3548 | ||
93ee8dfb | 3549 | if (GET_CODE (PATTERN (insn)) != SEQUENCE) |
3550 | continue; | |
3551 | ||
3552 | rtx_sequence *pat = as_a <rtx_sequence *> (PATTERN (insn)); | |
3553 | ||
3554 | if (!jump_to_label_p (pat->insn (0))) | |
3555 | continue; | |
3556 | ||
3557 | if (JUMP_LABEL (pat->insn (0)) == function_return_label) | |
9cb2517e | 3558 | { |
3559 | kind = ret_rtx; | |
3560 | real_label = real_return_label; | |
3561 | } | |
93ee8dfb | 3562 | else if (JUMP_LABEL (pat->insn (0)) == function_simple_return_label) |
9cb2517e | 3563 | { |
3564 | kind = simple_return_rtx; | |
3565 | real_label = real_simple_return_label; | |
3566 | } | |
3567 | else | |
75040552 | 3568 | continue; |
3569 | ||
f9a00e9e | 3570 | jump_insn = as_a <rtx_jump_insn *> (pat->insn (0)); |
75040552 | 3571 | |
ee8cf775 | 3572 | /* If we can't make the jump into a RETURN, try to redirect it to the best |
75040552 | 3573 | RETURN and go on to the next insn. */ |
9cb2517e | 3574 | if (!reorg_redirect_jump (jump_insn, kind)) |
75040552 | 3575 | { |
ee8cf775 | 3576 | /* Make sure redirecting the jump will not invalidate the delay |
3577 | slot insns. */ | |
9cb2517e | 3578 | if (redirect_with_delay_slots_safe_p (jump_insn, real_label, insn)) |
3579 | reorg_redirect_jump (jump_insn, real_label); | |
75040552 | 3580 | continue; |
3581 | } | |
3582 | ||
3583 | /* See if this RETURN can accept the insns current in its delay slot. | |
3584 | It can if it has more or an equal number of slots and the contents | |
3585 | of each is valid. */ | |
3586 | ||
45c67dee | 3587 | flags = get_jump_flags (jump_insn, JUMP_LABEL (jump_insn)); |
75040552 | 3588 | slots = num_delay_slots (jump_insn); |
3589 | if (slots >= XVECLEN (pat, 0) - 1) | |
3590 | { | |
3591 | for (i = 1; i < XVECLEN (pat, 0); i++) | |
3592 | if (! ( | |
9d463a01 | 3593 | #if ANNUL_IFFALSE_SLOTS |
75040552 | 3594 | (INSN_ANNULLED_BRANCH_P (jump_insn) |
91a55c11 | 3595 | && INSN_FROM_TARGET_P (pat->insn (i))) |
75040552 | 3596 | ? eligible_for_annul_false (jump_insn, i - 1, |
91a55c11 | 3597 | pat->insn (i), flags) : |
75040552 | 3598 | #endif |
9d463a01 | 3599 | #if ANNUL_IFTRUE_SLOTS |
75040552 | 3600 | (INSN_ANNULLED_BRANCH_P (jump_insn) |
91a55c11 | 3601 | && ! INSN_FROM_TARGET_P (pat->insn (i))) |
75040552 | 3602 | ? eligible_for_annul_true (jump_insn, i - 1, |
91a55c11 | 3603 | pat->insn (i), flags) : |
75040552 | 3604 | #endif |
875b3f3b | 3605 | eligible_for_delay (jump_insn, i - 1, |
91a55c11 | 3606 | pat->insn (i), flags))) |
75040552 | 3607 | break; |
3608 | } | |
3609 | else | |
3610 | i = 0; | |
3611 | ||
3612 | if (i == XVECLEN (pat, 0)) | |
3613 | continue; | |
3614 | ||
3615 | /* We have to do something with this insn. If it is an unconditional | |
3616 | RETURN, delete the SEQUENCE and output the individual insns, | |
3617 | followed by the RETURN. Then set things up so we try to find | |
3618 | insns for its delay slots, if it needs some. */ | |
9cb2517e | 3619 | if (ANY_RETURN_P (PATTERN (jump_insn))) |
75040552 | 3620 | { |
91a55c11 | 3621 | rtx_insn *prev = PREV_INSN (insn); |
75040552 | 3622 | |
e4bf866d | 3623 | delete_related_insns (insn); |
75040552 | 3624 | for (i = 1; i < XVECLEN (pat, 0); i++) |
3625 | prev = emit_insn_after (PATTERN (XVECEXP (pat, 0, i)), prev); | |
3626 | ||
3627 | insn = emit_jump_insn_after (PATTERN (jump_insn), prev); | |
3628 | emit_barrier_after (insn); | |
3629 | ||
3630 | if (slots) | |
3631 | obstack_ptr_grow (&unfilled_slots_obstack, insn); | |
3632 | } | |
3633 | else | |
3634 | /* It is probably more efficient to keep this with its current | |
3635 | delay slot as a branch to a RETURN. */ | |
9cb2517e | 3636 | reorg_redirect_jump (jump_insn, real_label); |
75040552 | 3637 | } |
3638 | ||
3639 | /* Now delete REAL_RETURN_LABEL if we never used it. Then try to fill any | |
3640 | new delay slots we have created. */ | |
9cb2517e | 3641 | if (real_return_label != NULL_RTX && --LABEL_NUSES (real_return_label) == 0) |
e4bf866d | 3642 | delete_related_insns (real_return_label); |
9cb2517e | 3643 | if (real_simple_return_label != NULL_RTX |
3644 | && --LABEL_NUSES (real_simple_return_label) == 0) | |
3645 | delete_related_insns (real_simple_return_label); | |
75040552 | 3646 | |
b44bc055 | 3647 | fill_simple_delay_slots (1); |
3648 | fill_simple_delay_slots (0); | |
75040552 | 3649 | } |
75040552 | 3650 | \f |
3651 | /* Try to find insns to place in delay slots. */ | |
3652 | ||
5a2fb01f | 3653 | static void |
575a12f2 | 3654 | dbr_schedule (rtx_insn *first) |
75040552 | 3655 | { |
575a12f2 | 3656 | rtx_insn *insn, *next, *epilogue_insn = 0; |
75040552 | 3657 | int i; |
9cb2517e | 3658 | bool need_return_insns; |
75040552 | 3659 | |
875b3f3b | 3660 | /* If the current function has no insns other than the prologue and |
bb4583cf | 3661 | epilogue, then do not try to fill any delay slots. */ |
a28770e1 | 3662 | if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS) |
bb4583cf | 3663 | return; |
3664 | ||
75040552 | 3665 | /* Find the highest INSN_UID and allocate and initialize our map from |
3666 | INSN_UID's to position in code. */ | |
3667 | for (max_uid = 0, insn = first; insn; insn = NEXT_INSN (insn)) | |
22af0c85 | 3668 | { |
3669 | if (INSN_UID (insn) > max_uid) | |
3670 | max_uid = INSN_UID (insn); | |
6d7dc5b9 | 3671 | if (NOTE_P (insn) |
ad4583d9 | 3672 | && NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG) |
22af0c85 | 3673 | epilogue_insn = insn; |
3674 | } | |
75040552 | 3675 | |
225ab426 | 3676 | uid_to_ruid = XNEWVEC (int, max_uid + 1); |
75040552 | 3677 | for (i = 0, insn = first; insn; i++, insn = NEXT_INSN (insn)) |
3678 | uid_to_ruid[INSN_UID (insn)] = i; | |
875b3f3b | 3679 | |
75040552 | 3680 | /* Initialize the list of insns that need filling. */ |
3681 | if (unfilled_firstobj == 0) | |
3682 | { | |
3683 | gcc_obstack_init (&unfilled_slots_obstack); | |
225ab426 | 3684 | unfilled_firstobj = XOBNEWVAR (&unfilled_slots_obstack, rtx, 0); |
75040552 | 3685 | } |
3686 | ||
3687 | for (insn = next_active_insn (first); insn; insn = next_active_insn (insn)) | |
3688 | { | |
3689 | rtx target; | |
3690 | ||
75040552 | 3691 | /* Skip vector tables. We can't get attributes for them. */ |
971ba038 | 3692 | if (JUMP_TABLE_DATA_P (insn)) |
75040552 | 3693 | continue; |
875b3f3b | 3694 | |
91f71fa3 | 3695 | if (JUMP_P (insn)) |
3696 | INSN_ANNULLED_BRANCH_P (insn) = 0; | |
3697 | INSN_FROM_TARGET_P (insn) = 0; | |
3698 | ||
75040552 | 3699 | if (num_delay_slots (insn) > 0) |
3700 | obstack_ptr_grow (&unfilled_slots_obstack, insn); | |
3701 | ||
3702 | /* Ensure all jumps go to the last of a set of consecutive labels. */ | |
6d7dc5b9 | 3703 | if (JUMP_P (insn) |
4fbe8fa7 | 3704 | && (condjump_p (insn) || condjump_in_parallel_p (insn)) |
4115ac36 | 3705 | && !ANY_RETURN_P (JUMP_LABEL (insn)) |
c2c03a95 | 3706 | && ((target = skip_consecutive_labels (JUMP_LABEL (insn))) |
75040552 | 3707 | != JUMP_LABEL (insn))) |
f9a00e9e | 3708 | redirect_jump (as_a <rtx_jump_insn *> (insn), target, 1); |
75040552 | 3709 | } |
3710 | ||
29bd1808 | 3711 | init_resource_info (epilogue_insn); |
22af0c85 | 3712 | |
75040552 | 3713 | /* Show we haven't computed an end-of-function label yet. */ |
575a12f2 | 3714 | function_return_label = function_simple_return_label = NULL; |
75040552 | 3715 | |
75040552 | 3716 | /* Initialize the statistics for this function. */ |
f0af5a88 | 3717 | memset (num_insns_needing_delays, 0, sizeof num_insns_needing_delays); |
3718 | memset (num_filled_delays, 0, sizeof num_filled_delays); | |
75040552 | 3719 | |
3720 | /* Now do the delay slot filling. Try everything twice in case earlier | |
3721 | changes make more slots fillable. */ | |
3722 | ||
3723 | for (reorg_pass_number = 0; | |
3724 | reorg_pass_number < MAX_REORG_PASSES; | |
3725 | reorg_pass_number++) | |
3726 | { | |
b44bc055 | 3727 | fill_simple_delay_slots (1); |
3728 | fill_simple_delay_slots (0); | |
0f177fa9 | 3729 | if (!targetm.no_speculation_in_delay_slots_p ()) |
3730 | fill_eager_delay_slots (); | |
75040552 | 3731 | relax_delay_slots (first); |
3732 | } | |
3733 | ||
75040552 | 3734 | /* If we made an end of function label, indicate that it is now |
3735 | safe to delete it by undoing our prior adjustment to LABEL_NUSES. | |
3736 | If it is now unused, delete it. */ | |
9cb2517e | 3737 | if (function_return_label && --LABEL_NUSES (function_return_label) == 0) |
3738 | delete_related_insns (function_return_label); | |
3739 | if (function_simple_return_label | |
3740 | && --LABEL_NUSES (function_simple_return_label) == 0) | |
3741 | delete_related_insns (function_simple_return_label); | |
75040552 | 3742 | |
9cb2517e | 3743 | need_return_insns = false; |
5da5e283 | 3744 | need_return_insns |= targetm.have_return () && function_return_label != 0; |
3745 | need_return_insns |= (targetm.have_simple_return () | |
3746 | && function_simple_return_label != 0); | |
9cb2517e | 3747 | if (need_return_insns) |
3748 | make_return_insns (first); | |
75040552 | 3749 | |
fc6b8ace | 3750 | /* Delete any USE insns made by update_block; subsequent passes don't need |
3751 | them or know how to deal with them. */ | |
3752 | for (insn = first; insn; insn = next) | |
3753 | { | |
3754 | next = NEXT_INSN (insn); | |
3755 | ||
3756 | if (NONJUMP_INSN_P (insn) && GET_CODE (PATTERN (insn)) == USE | |
3757 | && INSN_P (XEXP (PATTERN (insn), 0))) | |
3758 | next = delete_related_insns (insn); | |
3759 | } | |
3760 | ||
75040552 | 3761 | obstack_free (&unfilled_slots_obstack, unfilled_firstobj); |
3762 | ||
3763 | /* It is not clear why the line below is needed, but it does seem to be. */ | |
225ab426 | 3764 | unfilled_firstobj = XOBNEWVAR (&unfilled_slots_obstack, rtx, 0); |
75040552 | 3765 | |
a4235fd2 | 3766 | if (dump_file) |
75040552 | 3767 | { |
19cb6b50 | 3768 | int i, j, need_comma; |
78a9de8d | 3769 | int total_delay_slots[MAX_DELAY_HISTOGRAM + 1]; |
3770 | int total_annul_slots[MAX_DELAY_HISTOGRAM + 1]; | |
75040552 | 3771 | |
3772 | for (reorg_pass_number = 0; | |
3773 | reorg_pass_number < MAX_REORG_PASSES; | |
3774 | reorg_pass_number++) | |
3775 | { | |
a4235fd2 | 3776 | fprintf (dump_file, ";; Reorg pass #%d:\n", reorg_pass_number + 1); |
75040552 | 3777 | for (i = 0; i < NUM_REORG_FUNCTIONS; i++) |
3778 | { | |
3779 | need_comma = 0; | |
a4235fd2 | 3780 | fprintf (dump_file, ";; Reorg function #%d\n", i); |
75040552 | 3781 | |
a4235fd2 | 3782 | fprintf (dump_file, ";; %d insns needing delay slots\n;; ", |
75040552 | 3783 | num_insns_needing_delays[i][reorg_pass_number]); |
3784 | ||
78a9de8d | 3785 | for (j = 0; j < MAX_DELAY_HISTOGRAM + 1; j++) |
75040552 | 3786 | if (num_filled_delays[i][j][reorg_pass_number]) |
3787 | { | |
3788 | if (need_comma) | |
a4235fd2 | 3789 | fprintf (dump_file, ", "); |
75040552 | 3790 | need_comma = 1; |
a4235fd2 | 3791 | fprintf (dump_file, "%d got %d delays", |
75040552 | 3792 | num_filled_delays[i][j][reorg_pass_number], j); |
3793 | } | |
a4235fd2 | 3794 | fprintf (dump_file, "\n"); |
75040552 | 3795 | } |
3796 | } | |
f0af5a88 | 3797 | memset (total_delay_slots, 0, sizeof total_delay_slots); |
3798 | memset (total_annul_slots, 0, sizeof total_annul_slots); | |
78a9de8d | 3799 | for (insn = first; insn; insn = NEXT_INSN (insn)) |
3800 | { | |
dd1286fb | 3801 | if (! insn->deleted () |
6d7dc5b9 | 3802 | && NONJUMP_INSN_P (insn) |
78a9de8d | 3803 | && GET_CODE (PATTERN (insn)) != USE |
3804 | && GET_CODE (PATTERN (insn)) != CLOBBER) | |
3805 | { | |
3806 | if (GET_CODE (PATTERN (insn)) == SEQUENCE) | |
3807 | { | |
7e66a69e | 3808 | rtx control; |
78a9de8d | 3809 | j = XVECLEN (PATTERN (insn), 0) - 1; |
3810 | if (j > MAX_DELAY_HISTOGRAM) | |
3811 | j = MAX_DELAY_HISTOGRAM; | |
7e66a69e | 3812 | control = XVECEXP (PATTERN (insn), 0, 0); |
3813 | if (JUMP_P (control) && INSN_ANNULLED_BRANCH_P (control)) | |
78a9de8d | 3814 | total_annul_slots[j]++; |
3815 | else | |
3816 | total_delay_slots[j]++; | |
3817 | } | |
875b3f3b | 3818 | else if (num_delay_slots (insn) > 0) |
78a9de8d | 3819 | total_delay_slots[0]++; |
3820 | } | |
3821 | } | |
a4235fd2 | 3822 | fprintf (dump_file, ";; Reorg totals: "); |
78a9de8d | 3823 | need_comma = 0; |
3824 | for (j = 0; j < MAX_DELAY_HISTOGRAM + 1; j++) | |
3825 | { | |
3826 | if (total_delay_slots[j]) | |
3827 | { | |
3828 | if (need_comma) | |
a4235fd2 | 3829 | fprintf (dump_file, ", "); |
78a9de8d | 3830 | need_comma = 1; |
a4235fd2 | 3831 | fprintf (dump_file, "%d got %d delays", total_delay_slots[j], j); |
78a9de8d | 3832 | } |
3833 | } | |
a4235fd2 | 3834 | fprintf (dump_file, "\n"); |
9d463a01 | 3835 | |
3836 | if (ANNUL_IFTRUE_SLOTS || ANNUL_IFFALSE_SLOTS) | |
78a9de8d | 3837 | { |
9d463a01 | 3838 | fprintf (dump_file, ";; Reorg annuls: "); |
3839 | need_comma = 0; | |
3840 | for (j = 0; j < MAX_DELAY_HISTOGRAM + 1; j++) | |
78a9de8d | 3841 | { |
9d463a01 | 3842 | if (total_annul_slots[j]) |
3843 | { | |
3844 | if (need_comma) | |
3845 | fprintf (dump_file, ", "); | |
3846 | need_comma = 1; | |
3847 | fprintf (dump_file, "%d got %d delays", total_annul_slots[j], j); | |
3848 | } | |
78a9de8d | 3849 | } |
9d463a01 | 3850 | fprintf (dump_file, "\n"); |
78a9de8d | 3851 | } |
9d463a01 | 3852 | |
a4235fd2 | 3853 | fprintf (dump_file, "\n"); |
75040552 | 3854 | } |
48163999 | 3855 | |
14e08599 | 3856 | if (!sibling_labels.is_empty ()) |
3857 | { | |
3858 | update_alignments (sibling_labels); | |
3859 | sibling_labels.release (); | |
3860 | } | |
3861 | ||
29bd1808 | 3862 | free_resource_info (); |
8b861be4 | 3863 | free (uid_to_ruid); |
2061be83 | 3864 | crtl->dbr_scheduled_p = true; |
75040552 | 3865 | } |
77fce4cd | 3866 | \f |
77fce4cd | 3867 | /* Run delay slot optimization. */ |
2a1990e9 | 3868 | static unsigned int |
77fce4cd | 3869 | rest_of_handle_delay_slots (void) |
3870 | { | |
9d463a01 | 3871 | if (DELAY_SLOTS) |
3872 | dbr_schedule (get_insns ()); | |
3873 | ||
2a1990e9 | 3874 | return 0; |
3072d30e | 3875 | } |
77fce4cd | 3876 | |
7620bc82 | 3877 | namespace { |
3878 | ||
3879 | const pass_data pass_data_delay_slots = | |
77fce4cd | 3880 | { |
cbe8bda8 | 3881 | RTL_PASS, /* type */ |
3882 | "dbr", /* name */ | |
3883 | OPTGROUP_NONE, /* optinfo_flags */ | |
cbe8bda8 | 3884 | TV_DBR_SCHED, /* tv_id */ |
3885 | 0, /* properties_required */ | |
3886 | 0, /* properties_provided */ | |
3887 | 0, /* properties_destroyed */ | |
3888 | 0, /* todo_flags_start */ | |
3889 | 0, /* todo_flags_finish */ | |
77fce4cd | 3890 | }; |
3891 | ||
7620bc82 | 3892 | class pass_delay_slots : public rtl_opt_pass |
cbe8bda8 | 3893 | { |
3894 | public: | |
9af5ce0c | 3895 | pass_delay_slots (gcc::context *ctxt) |
3896 | : rtl_opt_pass (pass_data_delay_slots, ctxt) | |
cbe8bda8 | 3897 | {} |
3898 | ||
3899 | /* opt_pass methods: */ | |
31315c24 | 3900 | virtual bool gate (function *); |
65b0537f | 3901 | virtual unsigned int execute (function *) |
3902 | { | |
3903 | return rest_of_handle_delay_slots (); | |
3904 | } | |
cbe8bda8 | 3905 | |
3906 | }; // class pass_delay_slots | |
3907 | ||
31315c24 | 3908 | bool |
3909 | pass_delay_slots::gate (function *) | |
3910 | { | |
31315c24 | 3911 | /* At -O0 dataflow info isn't updated after RA. */ |
9d463a01 | 3912 | if (DELAY_SLOTS) |
3913 | return optimize > 0 && flag_delayed_branch && !crtl->dbr_scheduled_p; | |
3914 | ||
3915 | return false; | |
31315c24 | 3916 | } |
3917 | ||
7620bc82 | 3918 | } // anon namespace |
3919 | ||
cbe8bda8 | 3920 | rtl_opt_pass * |
3921 | make_pass_delay_slots (gcc::context *ctxt) | |
3922 | { | |
3923 | return new pass_delay_slots (ctxt); | |
3924 | } | |
3925 | ||
77fce4cd | 3926 | /* Machine dependent reorg pass. */ |
77fce4cd | 3927 | |
7620bc82 | 3928 | namespace { |
3929 | ||
3930 | const pass_data pass_data_machine_reorg = | |
77fce4cd | 3931 | { |
cbe8bda8 | 3932 | RTL_PASS, /* type */ |
3933 | "mach", /* name */ | |
3934 | OPTGROUP_NONE, /* optinfo_flags */ | |
cbe8bda8 | 3935 | TV_MACH_DEP, /* tv_id */ |
3936 | 0, /* properties_required */ | |
3937 | 0, /* properties_provided */ | |
3938 | 0, /* properties_destroyed */ | |
3939 | 0, /* todo_flags_start */ | |
3940 | 0, /* todo_flags_finish */ | |
77fce4cd | 3941 | }; |
cbe8bda8 | 3942 | |
7620bc82 | 3943 | class pass_machine_reorg : public rtl_opt_pass |
cbe8bda8 | 3944 | { |
3945 | public: | |
9af5ce0c | 3946 | pass_machine_reorg (gcc::context *ctxt) |
3947 | : rtl_opt_pass (pass_data_machine_reorg, ctxt) | |
cbe8bda8 | 3948 | {} |
3949 | ||
3950 | /* opt_pass methods: */ | |
31315c24 | 3951 | virtual bool gate (function *) |
3952 | { | |
3953 | return targetm.machine_dependent_reorg != 0; | |
3954 | } | |
3955 | ||
65b0537f | 3956 | virtual unsigned int execute (function *) |
3957 | { | |
3958 | targetm.machine_dependent_reorg (); | |
3959 | return 0; | |
3960 | } | |
cbe8bda8 | 3961 | |
3962 | }; // class pass_machine_reorg | |
3963 | ||
7620bc82 | 3964 | } // anon namespace |
3965 | ||
cbe8bda8 | 3966 | rtl_opt_pass * |
3967 | make_pass_machine_reorg (gcc::context *ctxt) | |
3968 | { | |
3969 | return new pass_machine_reorg (ctxt); | |
3970 | } |