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f8934be7 | 1 | /* Loop unrolling. |
818ab71a | 2 | Copyright (C) 2002-2016 Free Software Foundation, Inc. |
a29c7ea6 ZD |
3 | |
4 | This file is part of GCC. | |
5 | ||
6 | GCC is free software; you can redistribute it and/or modify it under | |
7 | the terms of the GNU General Public License as published by the Free | |
9dcd6f09 | 8 | Software Foundation; either version 3, or (at your option) any later |
a29c7ea6 ZD |
9 | version. |
10 | ||
11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
14 | for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
a29c7ea6 ZD |
19 | |
20 | #include "config.h" | |
21 | #include "system.h" | |
22 | #include "coretypes.h" | |
c7131fb2 | 23 | #include "backend.h" |
957060b5 | 24 | #include "target.h" |
a29c7ea6 | 25 | #include "rtl.h" |
4d648807 | 26 | #include "tree.h" |
957060b5 | 27 | #include "cfghooks.h" |
4d0cdd0c | 28 | #include "memmodel.h" |
957060b5 AM |
29 | #include "optabs.h" |
30 | #include "emit-rtl.h" | |
31 | #include "recog.h" | |
59f2e9d8 | 32 | #include "profile.h" |
60393bbc | 33 | #include "cfgrtl.h" |
a29c7ea6 | 34 | #include "cfgloop.h" |
a29c7ea6 | 35 | #include "params.h" |
36566b39 | 36 | #include "dojump.h" |
a29c7ea6 | 37 | #include "expr.h" |
7ee2468b | 38 | #include "dumpfile.h" |
a29c7ea6 | 39 | |
f8934be7 JH |
40 | /* This pass performs loop unrolling. We only perform this |
41 | optimization on innermost loops (with single exception) because | |
a29c7ea6 ZD |
42 | the impact on performance is greatest here, and we want to avoid |
43 | unnecessary code size growth. The gain is caused by greater sequentiality | |
4d6922ee | 44 | of code, better code to optimize for further passes and in some cases |
a29c7ea6 ZD |
45 | by fewer testings of exit conditions. The main problem is code growth, |
46 | that impacts performance negatively due to effect of caches. | |
47 | ||
48 | What we do: | |
49 | ||
a29c7ea6 ZD |
50 | -- unrolling of loops that roll constant times; this is almost always |
51 | win, as we get rid of exit condition tests. | |
52 | -- unrolling of loops that roll number of times that we can compute | |
53 | in runtime; we also get rid of exit condition tests here, but there | |
54 | is the extra expense for calculating the number of iterations | |
55 | -- simple unrolling of remaining loops; this is performed only if we | |
56 | are asked to, as the gain is questionable in this case and often | |
57 | it may even slow down the code | |
58 | For more detailed descriptions of each of those, see comments at | |
59 | appropriate function below. | |
60 | ||
61 | There is a lot of parameters (defined and described in params.def) that | |
f8934be7 | 62 | control how much we unroll. |
a29c7ea6 ZD |
63 | |
64 | ??? A great problem is that we don't have a good way how to determine | |
65 | how many times we should unroll the loop; the experiments I have made | |
66 | showed that this choice may affect performance in order of several %. | |
67 | */ | |
68 | ||
113d659a ZD |
69 | /* Information about induction variables to split. */ |
70 | ||
71 | struct iv_to_split | |
72 | { | |
95ecfb26 | 73 | rtx_insn *insn; /* The insn in that the induction variable occurs. */ |
4a0c3fde | 74 | rtx orig_var; /* The variable (register) for the IV before split. */ |
113d659a ZD |
75 | rtx base_var; /* The variable on that the values in the further |
76 | iterations are based. */ | |
77 | rtx step; /* Step of the induction variable. */ | |
a9f6ecee | 78 | struct iv_to_split *next; /* Next entry in walking order. */ |
113d659a ZD |
79 | }; |
80 | ||
f37a4f14 RE |
81 | /* Information about accumulators to expand. */ |
82 | ||
83 | struct var_to_expand | |
84 | { | |
95ecfb26 | 85 | rtx_insn *insn; /* The insn in that the variable expansion occurs. */ |
471854f8 | 86 | rtx reg; /* The accumulator which is expanded. */ |
9771b263 | 87 | vec<rtx> var_expansions; /* The copies of the accumulator which is expanded. */ |
a9f6ecee | 88 | struct var_to_expand *next; /* Next entry in walking order. */ |
b8698a0f | 89 | enum rtx_code op; /* The type of the accumulation - addition, subtraction |
f37a4f14 RE |
90 | or multiplication. */ |
91 | int expansion_count; /* Count the number of expansions generated so far. */ | |
92 | int reuse_expansion; /* The expansion we intend to reuse to expand | |
b8698a0f L |
93 | the accumulator. If REUSE_EXPANSION is 0 reuse |
94 | the original accumulator. Else use | |
f37a4f14 RE |
95 | var_expansions[REUSE_EXPANSION - 1]. */ |
96 | }; | |
97 | ||
4a8fb1a1 LC |
98 | /* Hashtable helper for iv_to_split. */ |
99 | ||
95fbe13e | 100 | struct iv_split_hasher : free_ptr_hash <iv_to_split> |
4a8fb1a1 | 101 | { |
67f58944 TS |
102 | static inline hashval_t hash (const iv_to_split *); |
103 | static inline bool equal (const iv_to_split *, const iv_to_split *); | |
4a8fb1a1 LC |
104 | }; |
105 | ||
106 | ||
107 | /* A hash function for information about insns to split. */ | |
108 | ||
109 | inline hashval_t | |
67f58944 | 110 | iv_split_hasher::hash (const iv_to_split *ivts) |
4a8fb1a1 LC |
111 | { |
112 | return (hashval_t) INSN_UID (ivts->insn); | |
113 | } | |
114 | ||
115 | /* An equality functions for information about insns to split. */ | |
116 | ||
117 | inline bool | |
67f58944 | 118 | iv_split_hasher::equal (const iv_to_split *i1, const iv_to_split *i2) |
4a8fb1a1 LC |
119 | { |
120 | return i1->insn == i2->insn; | |
121 | } | |
122 | ||
123 | /* Hashtable helper for iv_to_split. */ | |
124 | ||
95fbe13e | 125 | struct var_expand_hasher : free_ptr_hash <var_to_expand> |
4a8fb1a1 | 126 | { |
67f58944 TS |
127 | static inline hashval_t hash (const var_to_expand *); |
128 | static inline bool equal (const var_to_expand *, const var_to_expand *); | |
4a8fb1a1 LC |
129 | }; |
130 | ||
131 | /* Return a hash for VES. */ | |
132 | ||
133 | inline hashval_t | |
67f58944 | 134 | var_expand_hasher::hash (const var_to_expand *ves) |
4a8fb1a1 LC |
135 | { |
136 | return (hashval_t) INSN_UID (ves->insn); | |
137 | } | |
138 | ||
139 | /* Return true if I1 and I2 refer to the same instruction. */ | |
140 | ||
141 | inline bool | |
67f58944 | 142 | var_expand_hasher::equal (const var_to_expand *i1, const var_to_expand *i2) |
4a8fb1a1 LC |
143 | { |
144 | return i1->insn == i2->insn; | |
145 | } | |
146 | ||
f37a4f14 RE |
147 | /* Information about optimization applied in |
148 | the unrolled loop. */ | |
149 | ||
150 | struct opt_info | |
113d659a | 151 | { |
c203e8a7 | 152 | hash_table<iv_split_hasher> *insns_to_split; /* A hashtable of insns to |
4a8fb1a1 | 153 | split. */ |
a9f6ecee AO |
154 | struct iv_to_split *iv_to_split_head; /* The first iv to split. */ |
155 | struct iv_to_split **iv_to_split_tail; /* Pointer to the tail of the list. */ | |
c203e8a7 | 156 | hash_table<var_expand_hasher> *insns_with_var_to_expand; /* A hashtable of |
4a8fb1a1 | 157 | insns with accumulators to expand. */ |
a9f6ecee AO |
158 | struct var_to_expand *var_to_expand_head; /* The first var to expand. */ |
159 | struct var_to_expand **var_to_expand_tail; /* Pointer to the tail of the list. */ | |
f37a4f14 RE |
160 | unsigned first_new_block; /* The first basic block that was |
161 | duplicated. */ | |
162 | basic_block loop_exit; /* The loop exit basic block. */ | |
163 | basic_block loop_preheader; /* The loop preheader basic block. */ | |
113d659a ZD |
164 | }; |
165 | ||
d47cc544 SB |
166 | static void decide_unroll_stupid (struct loop *, int); |
167 | static void decide_unroll_constant_iterations (struct loop *, int); | |
168 | static void decide_unroll_runtime_iterations (struct loop *, int); | |
d73be268 | 169 | static void unroll_loop_stupid (struct loop *); |
f8934be7 | 170 | static void decide_unrolling (int); |
d73be268 ZD |
171 | static void unroll_loop_constant_iterations (struct loop *); |
172 | static void unroll_loop_runtime_iterations (struct loop *); | |
f37a4f14 RE |
173 | static struct opt_info *analyze_insns_in_loop (struct loop *); |
174 | static void opt_info_start_duplication (struct opt_info *); | |
175 | static void apply_opt_in_copies (struct opt_info *, unsigned, bool, bool); | |
176 | static void free_opt_info (struct opt_info *); | |
95ecfb26 | 177 | static struct var_to_expand *analyze_insn_to_expand_var (struct loop*, rtx_insn *); |
60c48e4c | 178 | static bool referenced_in_one_insn_in_loop_p (struct loop *, rtx, int *); |
1b20d55a | 179 | static struct iv_to_split *analyze_iv_to_split_insn (rtx_insn *); |
95ecfb26 | 180 | static void expand_var_during_unrolling (struct var_to_expand *, rtx_insn *); |
a9f6ecee AO |
181 | static void insert_var_expansion_initialization (struct var_to_expand *, |
182 | basic_block); | |
183 | static void combine_var_copies_in_loop_exit (struct var_to_expand *, | |
184 | basic_block); | |
f37a4f14 | 185 | static rtx get_expansion (struct var_to_expand *); |
a29c7ea6 | 186 | |
f8934be7 | 187 | /* Emit a message summarizing the unroll that will be |
e25a6711 TJ |
188 | performed for LOOP, along with the loop's location LOCUS, if |
189 | appropriate given the dump or -fopt-info settings. */ | |
190 | ||
191 | static void | |
f8934be7 | 192 | report_unroll (struct loop *loop, location_t locus) |
e25a6711 | 193 | { |
e25a6711 TJ |
194 | int report_flags = MSG_OPTIMIZED_LOCATIONS | TDF_RTL | TDF_DETAILS; |
195 | ||
ad4db775 TJ |
196 | if (loop->lpt_decision.decision == LPT_NONE) |
197 | return; | |
198 | ||
e25a6711 TJ |
199 | if (!dump_enabled_p ()) |
200 | return; | |
201 | ||
f8934be7 JH |
202 | dump_printf_loc (report_flags, locus, |
203 | "loop unrolled %d times", | |
204 | loop->lpt_decision.times); | |
e25a6711 TJ |
205 | if (profile_info) |
206 | dump_printf (report_flags, | |
f8934be7 | 207 | " (header execution count %d)", |
e25a6711 | 208 | (int)loop->header->count); |
e25a6711 TJ |
209 | |
210 | dump_printf (report_flags, "\n"); | |
211 | } | |
212 | ||
f8934be7 | 213 | /* Decide whether unroll loops and how much. */ |
a29c7ea6 | 214 | static void |
f8934be7 | 215 | decide_unrolling (int flags) |
a29c7ea6 | 216 | { |
42fd6772 | 217 | struct loop *loop; |
a29c7ea6 ZD |
218 | |
219 | /* Scan the loops, inner ones first. */ | |
f0bd40b1 | 220 | FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) |
a29c7ea6 | 221 | { |
a29c7ea6 | 222 | loop->lpt_decision.decision = LPT_NONE; |
e25a6711 | 223 | location_t locus = get_loop_location (loop); |
a29c7ea6 | 224 | |
e25a6711 TJ |
225 | if (dump_enabled_p ()) |
226 | dump_printf_loc (TDF_RTL, locus, | |
227 | ";; *** Considering loop %d at BB %d for " | |
f8934be7 | 228 | "unrolling ***\n", |
e25a6711 | 229 | loop->num, loop->header->index); |
a29c7ea6 ZD |
230 | |
231 | /* Do not peel cold areas. */ | |
efd8f750 | 232 | if (optimize_loop_for_size_p (loop)) |
a29c7ea6 | 233 | { |
c263766c RH |
234 | if (dump_file) |
235 | fprintf (dump_file, ";; Not considering loop, cold area\n"); | |
a29c7ea6 ZD |
236 | continue; |
237 | } | |
238 | ||
239 | /* Can the loop be manipulated? */ | |
240 | if (!can_duplicate_loop_p (loop)) | |
241 | { | |
c263766c RH |
242 | if (dump_file) |
243 | fprintf (dump_file, | |
a29c7ea6 | 244 | ";; Not considering loop, cannot duplicate\n"); |
a29c7ea6 ZD |
245 | continue; |
246 | } | |
247 | ||
248 | /* Skip non-innermost loops. */ | |
249 | if (loop->inner) | |
250 | { | |
c263766c RH |
251 | if (dump_file) |
252 | fprintf (dump_file, ";; Not considering loop, is not innermost\n"); | |
a29c7ea6 ZD |
253 | continue; |
254 | } | |
255 | ||
256 | loop->ninsns = num_loop_insns (loop); | |
257 | loop->av_ninsns = average_num_loop_insns (loop); | |
258 | ||
259 | /* Try transformations one by one in decreasing order of | |
260 | priority. */ | |
261 | ||
d47cc544 | 262 | decide_unroll_constant_iterations (loop, flags); |
a29c7ea6 | 263 | if (loop->lpt_decision.decision == LPT_NONE) |
d47cc544 | 264 | decide_unroll_runtime_iterations (loop, flags); |
a29c7ea6 | 265 | if (loop->lpt_decision.decision == LPT_NONE) |
d47cc544 | 266 | decide_unroll_stupid (loop, flags); |
a29c7ea6 | 267 | |
f8934be7 | 268 | report_unroll (loop, locus); |
a29c7ea6 | 269 | } |
a29c7ea6 ZD |
270 | } |
271 | ||
f8934be7 JH |
272 | /* Unroll LOOPS. */ |
273 | void | |
274 | unroll_loops (int flags) | |
a29c7ea6 | 275 | { |
f8934be7 JH |
276 | struct loop *loop; |
277 | bool changed = false; | |
a29c7ea6 | 278 | |
f8934be7 JH |
279 | /* Now decide rest of unrolling. */ |
280 | decide_unrolling (flags); | |
a29c7ea6 | 281 | |
f8934be7 JH |
282 | /* Scan the loops, inner ones first. */ |
283 | FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) | |
a29c7ea6 | 284 | { |
f8934be7 JH |
285 | /* And perform the appropriate transformations. */ |
286 | switch (loop->lpt_decision.decision) | |
0c20a65f | 287 | { |
f8934be7 JH |
288 | case LPT_UNROLL_CONSTANT: |
289 | unroll_loop_constant_iterations (loop); | |
290 | changed = true; | |
291 | break; | |
292 | case LPT_UNROLL_RUNTIME: | |
293 | unroll_loop_runtime_iterations (loop); | |
294 | changed = true; | |
295 | break; | |
296 | case LPT_UNROLL_STUPID: | |
297 | unroll_loop_stupid (loop); | |
298 | changed = true; | |
299 | break; | |
300 | case LPT_NONE: | |
301 | break; | |
302 | default: | |
303 | gcc_unreachable (); | |
a29c7ea6 | 304 | } |
a29c7ea6 ZD |
305 | } |
306 | ||
f8934be7 JH |
307 | if (changed) |
308 | { | |
309 | calculate_dominance_info (CDI_DOMINATORS); | |
310 | fix_loop_structure (NULL); | |
311 | } | |
0c20a65f | 312 | |
f8934be7 JH |
313 | iv_analysis_done (); |
314 | } | |
a29c7ea6 | 315 | |
f8934be7 | 316 | /* Check whether exit of the LOOP is at the end of loop body. */ |
0c20a65f | 317 | |
f8934be7 JH |
318 | static bool |
319 | loop_exit_at_end_p (struct loop *loop) | |
a29c7ea6 | 320 | { |
50654f6c | 321 | struct niter_desc *desc = get_simple_loop_desc (loop); |
f8934be7 | 322 | rtx_insn *insn; |
35b07080 | 323 | |
f8934be7 JH |
324 | /* We should never have conditional in latch block. */ |
325 | gcc_assert (desc->in_edge->dest != loop->header); | |
b8698a0f | 326 | |
f8934be7 JH |
327 | if (desc->in_edge->dest != loop->latch) |
328 | return false; | |
113d659a | 329 | |
f8934be7 JH |
330 | /* Check that the latch is empty. */ |
331 | FOR_BB_INSNS (loop->latch, insn) | |
332 | { | |
333 | if (INSN_P (insn) && active_insn_p (insn)) | |
334 | return false; | |
35b07080 | 335 | } |
a29c7ea6 | 336 | |
f8934be7 | 337 | return true; |
a29c7ea6 ZD |
338 | } |
339 | ||
c263766c RH |
340 | /* Decide whether to unroll LOOP iterating constant number of times |
341 | and how much. */ | |
50654f6c | 342 | |
a29c7ea6 | 343 | static void |
d47cc544 | 344 | decide_unroll_constant_iterations (struct loop *loop, int flags) |
a29c7ea6 | 345 | { |
50654f6c ZD |
346 | unsigned nunroll, nunroll_by_av, best_copies, best_unroll = 0, n_copies, i; |
347 | struct niter_desc *desc; | |
807e902e | 348 | widest_int iterations; |
a29c7ea6 ZD |
349 | |
350 | if (!(flags & UAP_UNROLL)) | |
351 | { | |
352 | /* We were not asked to, just return back silently. */ | |
353 | return; | |
354 | } | |
355 | ||
c263766c RH |
356 | if (dump_file) |
357 | fprintf (dump_file, | |
358 | "\n;; Considering unrolling loop with constant " | |
359 | "number of iterations\n"); | |
a29c7ea6 ZD |
360 | |
361 | /* nunroll = total number of copies of the original loop body in | |
362 | unrolled loop (i.e. if it is 2, we have to duplicate loop body once. */ | |
363 | nunroll = PARAM_VALUE (PARAM_MAX_UNROLLED_INSNS) / loop->ninsns; | |
c263766c RH |
364 | nunroll_by_av |
365 | = PARAM_VALUE (PARAM_MAX_AVERAGE_UNROLLED_INSNS) / loop->av_ninsns; | |
a29c7ea6 ZD |
366 | if (nunroll > nunroll_by_av) |
367 | nunroll = nunroll_by_av; | |
368 | if (nunroll > (unsigned) PARAM_VALUE (PARAM_MAX_UNROLL_TIMES)) | |
369 | nunroll = PARAM_VALUE (PARAM_MAX_UNROLL_TIMES); | |
370 | ||
df0f3392 GG |
371 | if (targetm.loop_unroll_adjust) |
372 | nunroll = targetm.loop_unroll_adjust (nunroll, loop); | |
373 | ||
a29c7ea6 ZD |
374 | /* Skip big loops. */ |
375 | if (nunroll <= 1) | |
376 | { | |
c263766c RH |
377 | if (dump_file) |
378 | fprintf (dump_file, ";; Not considering loop, is too big\n"); | |
a29c7ea6 ZD |
379 | return; |
380 | } | |
381 | ||
382 | /* Check for simple loops. */ | |
50654f6c | 383 | desc = get_simple_loop_desc (loop); |
a29c7ea6 ZD |
384 | |
385 | /* Check number of iterations. */ | |
50654f6c | 386 | if (!desc->simple_p || !desc->const_iter || desc->assumptions) |
a29c7ea6 | 387 | { |
c263766c RH |
388 | if (dump_file) |
389 | fprintf (dump_file, | |
390 | ";; Unable to prove that the loop iterates constant times\n"); | |
a29c7ea6 ZD |
391 | return; |
392 | } | |
393 | ||
e598c332 JH |
394 | /* Check whether the loop rolls enough to consider. |
395 | Consult also loop bounds and profile; in the case the loop has more | |
396 | than one exit it may well loop less than determined maximal number | |
397 | of iterations. */ | |
398 | if (desc->niter < 2 * nunroll | |
71343877 | 399 | || ((get_estimated_loop_iterations (loop, &iterations) |
8c383600 | 400 | || get_likely_max_loop_iterations (loop, &iterations)) |
807e902e | 401 | && wi::ltu_p (iterations, 2 * nunroll))) |
a29c7ea6 | 402 | { |
c263766c RH |
403 | if (dump_file) |
404 | fprintf (dump_file, ";; Not unrolling loop, doesn't roll\n"); | |
a29c7ea6 ZD |
405 | return; |
406 | } | |
407 | ||
408 | /* Success; now compute number of iterations to unroll. We alter | |
409 | nunroll so that as few as possible copies of loop body are | |
e0bb17a8 | 410 | necessary, while still not decreasing the number of unrollings |
a29c7ea6 ZD |
411 | too much (at most by 1). */ |
412 | best_copies = 2 * nunroll + 10; | |
413 | ||
414 | i = 2 * nunroll + 2; | |
50654f6c ZD |
415 | if (i - 1 >= desc->niter) |
416 | i = desc->niter - 2; | |
a29c7ea6 ZD |
417 | |
418 | for (; i >= nunroll - 1; i--) | |
419 | { | |
50654f6c | 420 | unsigned exit_mod = desc->niter % (i + 1); |
a29c7ea6 | 421 | |
50654f6c | 422 | if (!loop_exit_at_end_p (loop)) |
a29c7ea6 | 423 | n_copies = exit_mod + i + 1; |
50654f6c ZD |
424 | else if (exit_mod != (unsigned) i |
425 | || desc->noloop_assumptions != NULL_RTX) | |
a29c7ea6 ZD |
426 | n_copies = exit_mod + i + 2; |
427 | else | |
428 | n_copies = i + 1; | |
429 | ||
430 | if (n_copies < best_copies) | |
431 | { | |
432 | best_copies = n_copies; | |
433 | best_unroll = i; | |
434 | } | |
435 | } | |
436 | ||
a29c7ea6 ZD |
437 | loop->lpt_decision.decision = LPT_UNROLL_CONSTANT; |
438 | loop->lpt_decision.times = best_unroll; | |
439 | } | |
440 | ||
4fc2e37d EB |
441 | /* Unroll LOOP with constant number of iterations LOOP->LPT_DECISION.TIMES times. |
442 | The transformation does this: | |
0c20a65f | 443 | |
a29c7ea6 ZD |
444 | for (i = 0; i < 102; i++) |
445 | body; | |
0c20a65f | 446 | |
4fc2e37d | 447 | ==> (LOOP->LPT_DECISION.TIMES == 3) |
0c20a65f | 448 | |
a29c7ea6 ZD |
449 | i = 0; |
450 | body; i++; | |
451 | body; i++; | |
452 | while (i < 102) | |
453 | { | |
454 | body; i++; | |
455 | body; i++; | |
456 | body; i++; | |
457 | body; i++; | |
458 | } | |
459 | */ | |
460 | static void | |
d73be268 | 461 | unroll_loop_constant_iterations (struct loop *loop) |
a29c7ea6 ZD |
462 | { |
463 | unsigned HOST_WIDE_INT niter; | |
464 | unsigned exit_mod; | |
ee8c1b05 | 465 | unsigned i; |
ee8c1b05 | 466 | edge e; |
a29c7ea6 | 467 | unsigned max_unroll = loop->lpt_decision.times; |
50654f6c ZD |
468 | struct niter_desc *desc = get_simple_loop_desc (loop); |
469 | bool exit_at_end = loop_exit_at_end_p (loop); | |
f37a4f14 | 470 | struct opt_info *opt_info = NULL; |
41806d92 | 471 | bool ok; |
b8698a0f | 472 | |
a29c7ea6 ZD |
473 | niter = desc->niter; |
474 | ||
113d659a ZD |
475 | /* Should not get here (such loop should be peeled instead). */ |
476 | gcc_assert (niter > max_unroll + 1); | |
a29c7ea6 ZD |
477 | |
478 | exit_mod = niter % (max_unroll + 1); | |
479 | ||
7ba9e72d | 480 | auto_sbitmap wont_exit (max_unroll + 1); |
f61e445a | 481 | bitmap_ones (wont_exit); |
a29c7ea6 | 482 | |
ef062b13 | 483 | auto_vec<edge> remove_edges; |
b8698a0f | 484 | if (flag_split_ivs_in_unroller |
f37a4f14 RE |
485 | || flag_variable_expansion_in_unroller) |
486 | opt_info = analyze_insns_in_loop (loop); | |
b8698a0f | 487 | |
50654f6c | 488 | if (!exit_at_end) |
a29c7ea6 | 489 | { |
50654f6c | 490 | /* The exit is not at the end of the loop; leave exit test |
a29c7ea6 ZD |
491 | in the first copy, so that the loops that start with test |
492 | of exit condition have continuous body after unrolling. */ | |
493 | ||
c263766c | 494 | if (dump_file) |
4fc2e37d | 495 | fprintf (dump_file, ";; Condition at beginning of loop.\n"); |
a29c7ea6 ZD |
496 | |
497 | /* Peel exit_mod iterations. */ | |
d7c028c0 | 498 | bitmap_clear_bit (wont_exit, 0); |
50654f6c | 499 | if (desc->noloop_assumptions) |
d7c028c0 | 500 | bitmap_clear_bit (wont_exit, 1); |
a29c7ea6 | 501 | |
50654f6c ZD |
502 | if (exit_mod) |
503 | { | |
f37a4f14 | 504 | opt_info_start_duplication (opt_info); |
41806d92 | 505 | ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop), |
d73be268 | 506 | exit_mod, |
50654f6c | 507 | wont_exit, desc->out_edge, |
ee8c1b05 | 508 | &remove_edges, |
7f7b1718 JH |
509 | DLTHE_FLAG_UPDATE_FREQ |
510 | | (opt_info && exit_mod > 1 | |
511 | ? DLTHE_RECORD_COPY_NUMBER | |
512 | : 0)); | |
41806d92 | 513 | gcc_assert (ok); |
50654f6c | 514 | |
f37a4f14 | 515 | if (opt_info && exit_mod > 1) |
b8698a0f L |
516 | apply_opt_in_copies (opt_info, exit_mod, false, false); |
517 | ||
50654f6c ZD |
518 | desc->noloop_assumptions = NULL_RTX; |
519 | desc->niter -= exit_mod; | |
807e902e | 520 | loop->nb_iterations_upper_bound -= exit_mod; |
e3a8f1fa | 521 | if (loop->any_estimate |
807e902e KZ |
522 | && wi::leu_p (exit_mod, loop->nb_iterations_estimate)) |
523 | loop->nb_iterations_estimate -= exit_mod; | |
e3a8f1fa JH |
524 | else |
525 | loop->any_estimate = false; | |
105e29c5 JH |
526 | if (loop->any_likely_upper_bound |
527 | && wi::leu_p (exit_mod, loop->nb_iterations_likely_upper_bound)) | |
528 | loop->nb_iterations_likely_upper_bound -= exit_mod; | |
529 | else | |
530 | loop->any_likely_upper_bound = false; | |
50654f6c | 531 | } |
a29c7ea6 | 532 | |
d7c028c0 | 533 | bitmap_set_bit (wont_exit, 1); |
a29c7ea6 ZD |
534 | } |
535 | else | |
536 | { | |
537 | /* Leave exit test in last copy, for the same reason as above if | |
538 | the loop tests the condition at the end of loop body. */ | |
539 | ||
c263766c | 540 | if (dump_file) |
4fc2e37d | 541 | fprintf (dump_file, ";; Condition at end of loop.\n"); |
a29c7ea6 ZD |
542 | |
543 | /* We know that niter >= max_unroll + 2; so we do not need to care of | |
544 | case when we would exit before reaching the loop. So just peel | |
50654f6c ZD |
545 | exit_mod + 1 iterations. */ |
546 | if (exit_mod != max_unroll | |
547 | || desc->noloop_assumptions) | |
a29c7ea6 | 548 | { |
d7c028c0 | 549 | bitmap_clear_bit (wont_exit, 0); |
50654f6c | 550 | if (desc->noloop_assumptions) |
d7c028c0 | 551 | bitmap_clear_bit (wont_exit, 1); |
b8698a0f | 552 | |
f37a4f14 | 553 | opt_info_start_duplication (opt_info); |
41806d92 | 554 | ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop), |
d73be268 | 555 | exit_mod + 1, |
41806d92 | 556 | wont_exit, desc->out_edge, |
ee8c1b05 | 557 | &remove_edges, |
7f7b1718 JH |
558 | DLTHE_FLAG_UPDATE_FREQ |
559 | | (opt_info && exit_mod > 0 | |
560 | ? DLTHE_RECORD_COPY_NUMBER | |
561 | : 0)); | |
41806d92 | 562 | gcc_assert (ok); |
b8698a0f | 563 | |
f37a4f14 RE |
564 | if (opt_info && exit_mod > 0) |
565 | apply_opt_in_copies (opt_info, exit_mod + 1, false, false); | |
113d659a | 566 | |
50654f6c | 567 | desc->niter -= exit_mod + 1; |
807e902e | 568 | loop->nb_iterations_upper_bound -= exit_mod + 1; |
e3a8f1fa | 569 | if (loop->any_estimate |
807e902e KZ |
570 | && wi::leu_p (exit_mod + 1, loop->nb_iterations_estimate)) |
571 | loop->nb_iterations_estimate -= exit_mod + 1; | |
e3a8f1fa JH |
572 | else |
573 | loop->any_estimate = false; | |
105e29c5 JH |
574 | if (loop->any_likely_upper_bound |
575 | && wi::leu_p (exit_mod + 1, loop->nb_iterations_likely_upper_bound)) | |
576 | loop->nb_iterations_likely_upper_bound -= exit_mod + 1; | |
577 | else | |
578 | loop->any_likely_upper_bound = false; | |
50654f6c ZD |
579 | desc->noloop_assumptions = NULL_RTX; |
580 | ||
d7c028c0 LC |
581 | bitmap_set_bit (wont_exit, 0); |
582 | bitmap_set_bit (wont_exit, 1); | |
a29c7ea6 ZD |
583 | } |
584 | ||
d7c028c0 | 585 | bitmap_clear_bit (wont_exit, max_unroll); |
a29c7ea6 ZD |
586 | } |
587 | ||
588 | /* Now unroll the loop. */ | |
b8698a0f | 589 | |
f37a4f14 | 590 | opt_info_start_duplication (opt_info); |
41806d92 | 591 | ok = duplicate_loop_to_header_edge (loop, loop_latch_edge (loop), |
d73be268 | 592 | max_unroll, |
41806d92 | 593 | wont_exit, desc->out_edge, |
ee8c1b05 | 594 | &remove_edges, |
7f7b1718 JH |
595 | DLTHE_FLAG_UPDATE_FREQ |
596 | | (opt_info | |
597 | ? DLTHE_RECORD_COPY_NUMBER | |
598 | : 0)); | |
41806d92 | 599 | gcc_assert (ok); |
a29c7ea6 | 600 | |
f37a4f14 | 601 | if (opt_info) |
113d659a | 602 | { |
f37a4f14 RE |
603 | apply_opt_in_copies (opt_info, max_unroll, true, true); |
604 | free_opt_info (opt_info); | |
113d659a ZD |
605 | } |
606 | ||
50654f6c ZD |
607 | if (exit_at_end) |
608 | { | |
6580ee77 | 609 | basic_block exit_block = get_bb_copy (desc->in_edge->src); |
50654f6c | 610 | /* Find a new in and out edge; they are in the last copy we have made. */ |
b8698a0f | 611 | |
628f6a4e | 612 | if (EDGE_SUCC (exit_block, 0)->dest == desc->out_edge->dest) |
50654f6c | 613 | { |
628f6a4e BE |
614 | desc->out_edge = EDGE_SUCC (exit_block, 0); |
615 | desc->in_edge = EDGE_SUCC (exit_block, 1); | |
50654f6c ZD |
616 | } |
617 | else | |
618 | { | |
628f6a4e BE |
619 | desc->out_edge = EDGE_SUCC (exit_block, 1); |
620 | desc->in_edge = EDGE_SUCC (exit_block, 0); | |
50654f6c ZD |
621 | } |
622 | } | |
623 | ||
624 | desc->niter /= max_unroll + 1; | |
e3a8f1fa | 625 | loop->nb_iterations_upper_bound |
807e902e | 626 | = wi::udiv_trunc (loop->nb_iterations_upper_bound, max_unroll + 1); |
e3a8f1fa JH |
627 | if (loop->any_estimate) |
628 | loop->nb_iterations_estimate | |
807e902e | 629 | = wi::udiv_trunc (loop->nb_iterations_estimate, max_unroll + 1); |
105e29c5 JH |
630 | if (loop->any_likely_upper_bound) |
631 | loop->nb_iterations_likely_upper_bound | |
632 | = wi::udiv_trunc (loop->nb_iterations_likely_upper_bound, max_unroll + 1); | |
50654f6c ZD |
633 | desc->niter_expr = GEN_INT (desc->niter); |
634 | ||
a29c7ea6 | 635 | /* Remove the edges. */ |
9771b263 | 636 | FOR_EACH_VEC_ELT (remove_edges, i, e) |
ee8c1b05 | 637 | remove_path (e); |
a29c7ea6 | 638 | |
c263766c RH |
639 | if (dump_file) |
640 | fprintf (dump_file, | |
641 | ";; Unrolled loop %d times, constant # of iterations %i insns\n", | |
642 | max_unroll, num_loop_insns (loop)); | |
a29c7ea6 ZD |
643 | } |
644 | ||
645 | /* Decide whether to unroll LOOP iterating runtime computable number of times | |
646 | and how much. */ | |
647 | static void | |
d47cc544 | 648 | decide_unroll_runtime_iterations (struct loop *loop, int flags) |
a29c7ea6 ZD |
649 | { |
650 | unsigned nunroll, nunroll_by_av, i; | |
50654f6c | 651 | struct niter_desc *desc; |
807e902e | 652 | widest_int iterations; |
a29c7ea6 ZD |
653 | |
654 | if (!(flags & UAP_UNROLL)) | |
655 | { | |
656 | /* We were not asked to, just return back silently. */ | |
657 | return; | |
658 | } | |
659 | ||
c263766c RH |
660 | if (dump_file) |
661 | fprintf (dump_file, | |
662 | "\n;; Considering unrolling loop with runtime " | |
663 | "computable number of iterations\n"); | |
a29c7ea6 ZD |
664 | |
665 | /* nunroll = total number of copies of the original loop body in | |
666 | unrolled loop (i.e. if it is 2, we have to duplicate loop body once. */ | |
667 | nunroll = PARAM_VALUE (PARAM_MAX_UNROLLED_INSNS) / loop->ninsns; | |
668 | nunroll_by_av = PARAM_VALUE (PARAM_MAX_AVERAGE_UNROLLED_INSNS) / loop->av_ninsns; | |
669 | if (nunroll > nunroll_by_av) | |
670 | nunroll = nunroll_by_av; | |
671 | if (nunroll > (unsigned) PARAM_VALUE (PARAM_MAX_UNROLL_TIMES)) | |
672 | nunroll = PARAM_VALUE (PARAM_MAX_UNROLL_TIMES); | |
673 | ||
40ac4f73 CB |
674 | if (targetm.loop_unroll_adjust) |
675 | nunroll = targetm.loop_unroll_adjust (nunroll, loop); | |
676 | ||
a29c7ea6 ZD |
677 | /* Skip big loops. */ |
678 | if (nunroll <= 1) | |
679 | { | |
c263766c RH |
680 | if (dump_file) |
681 | fprintf (dump_file, ";; Not considering loop, is too big\n"); | |
a29c7ea6 ZD |
682 | return; |
683 | } | |
684 | ||
685 | /* Check for simple loops. */ | |
50654f6c | 686 | desc = get_simple_loop_desc (loop); |
a29c7ea6 ZD |
687 | |
688 | /* Check simpleness. */ | |
50654f6c | 689 | if (!desc->simple_p || desc->assumptions) |
a29c7ea6 | 690 | { |
c263766c RH |
691 | if (dump_file) |
692 | fprintf (dump_file, | |
693 | ";; Unable to prove that the number of iterations " | |
694 | "can be counted in runtime\n"); | |
a29c7ea6 ZD |
695 | return; |
696 | } | |
697 | ||
50654f6c | 698 | if (desc->const_iter) |
a29c7ea6 | 699 | { |
c263766c RH |
700 | if (dump_file) |
701 | fprintf (dump_file, ";; Loop iterates constant times\n"); | |
a29c7ea6 ZD |
702 | return; |
703 | } | |
704 | ||
73367f92 | 705 | /* Check whether the loop rolls. */ |
71343877 | 706 | if ((get_estimated_loop_iterations (loop, &iterations) |
8c383600 | 707 | || get_likely_max_loop_iterations (loop, &iterations)) |
807e902e | 708 | && wi::ltu_p (iterations, 2 * nunroll)) |
a29c7ea6 | 709 | { |
c263766c RH |
710 | if (dump_file) |
711 | fprintf (dump_file, ";; Not unrolling loop, doesn't roll\n"); | |
a29c7ea6 ZD |
712 | return; |
713 | } | |
714 | ||
715 | /* Success; now force nunroll to be power of 2, as we are unable to | |
716 | cope with overflows in computation of number of iterations. */ | |
50654f6c ZD |
717 | for (i = 1; 2 * i <= nunroll; i *= 2) |
718 | continue; | |
a29c7ea6 ZD |
719 | |
720 | loop->lpt_decision.decision = LPT_UNROLL_RUNTIME; | |
721 | loop->lpt_decision.times = i - 1; | |
722 | } | |
723 | ||
7d93d987 ZD |
724 | /* Splits edge E and inserts the sequence of instructions INSNS on it, and |
725 | returns the newly created block. If INSNS is NULL_RTX, nothing is changed | |
726 | and NULL is returned instead. */ | |
598ec7bd ZD |
727 | |
728 | basic_block | |
95ecfb26 | 729 | split_edge_and_insert (edge e, rtx_insn *insns) |
598ec7bd | 730 | { |
7d93d987 ZD |
731 | basic_block bb; |
732 | ||
733 | if (!insns) | |
734 | return NULL; | |
b8698a0f | 735 | bb = split_edge (e); |
598ec7bd | 736 | emit_insn_after (insns, BB_END (bb)); |
7984c787 SB |
737 | |
738 | /* ??? We used to assume that INSNS can contain control flow insns, and | |
739 | that we had to try to find sub basic blocks in BB to maintain a valid | |
740 | CFG. For this purpose we used to set the BB_SUPERBLOCK flag on BB | |
741 | and call break_superblocks when going out of cfglayout mode. But it | |
742 | turns out that this never happens; and that if it does ever happen, | |
3bea341f | 743 | the verify_flow_info at the end of the RTL loop passes would fail. |
7984c787 SB |
744 | |
745 | There are two reasons why we expected we could have control flow insns | |
746 | in INSNS. The first is when a comparison has to be done in parts, and | |
747 | the second is when the number of iterations is computed for loops with | |
748 | the number of iterations known at runtime. In both cases, test cases | |
749 | to get control flow in INSNS appear to be impossible to construct: | |
750 | ||
751 | * If do_compare_rtx_and_jump needs several branches to do comparison | |
752 | in a mode that needs comparison by parts, we cannot analyze the | |
753 | number of iterations of the loop, and we never get to unrolling it. | |
754 | ||
755 | * The code in expand_divmod that was suspected to cause creation of | |
756 | branching code seems to be only accessed for signed division. The | |
757 | divisions used by # of iterations analysis are always unsigned. | |
758 | Problems might arise on architectures that emits branching code | |
759 | for some operations that may appear in the unroller (especially | |
760 | for division), but we have no such architectures. | |
761 | ||
762 | Considering all this, it was decided that we should for now assume | |
763 | that INSNS can in theory contain control flow insns, but in practice | |
764 | it never does. So we don't handle the theoretical case, and should | |
765 | a real failure ever show up, we have a pretty good clue for how to | |
766 | fix it. */ | |
767 | ||
598ec7bd ZD |
768 | return bb; |
769 | } | |
770 | ||
da4cfeac RB |
771 | /* Prepare a sequence comparing OP0 with OP1 using COMP and jumping to LABEL if |
772 | true, with probability PROB. If CINSN is not NULL, it is the insn to copy | |
773 | in order to create a jump. */ | |
774 | ||
95ecfb26 | 775 | static rtx_insn * |
1476d1bd MM |
776 | compare_and_jump_seq (rtx op0, rtx op1, enum rtx_code comp, |
777 | rtx_code_label *label, int prob, rtx_insn *cinsn) | |
da4cfeac | 778 | { |
1476d1bd MM |
779 | rtx_insn *seq; |
780 | rtx_jump_insn *jump; | |
95ecfb26 | 781 | rtx cond; |
ef4bddc2 | 782 | machine_mode mode; |
da4cfeac RB |
783 | |
784 | mode = GET_MODE (op0); | |
785 | if (mode == VOIDmode) | |
786 | mode = GET_MODE (op1); | |
787 | ||
788 | start_sequence (); | |
789 | if (GET_MODE_CLASS (mode) == MODE_CC) | |
790 | { | |
791 | /* A hack -- there seems to be no easy generic way how to make a | |
792 | conditional jump from a ccmode comparison. */ | |
793 | gcc_assert (cinsn); | |
794 | cond = XEXP (SET_SRC (pc_set (cinsn)), 0); | |
795 | gcc_assert (GET_CODE (cond) == comp); | |
796 | gcc_assert (rtx_equal_p (op0, XEXP (cond, 0))); | |
797 | gcc_assert (rtx_equal_p (op1, XEXP (cond, 1))); | |
798 | emit_jump_insn (copy_insn (PATTERN (cinsn))); | |
1476d1bd | 799 | jump = as_a <rtx_jump_insn *> (get_last_insn ()); |
da4cfeac RB |
800 | JUMP_LABEL (jump) = JUMP_LABEL (cinsn); |
801 | LABEL_NUSES (JUMP_LABEL (jump))++; | |
802 | redirect_jump (jump, label, 0); | |
803 | } | |
804 | else | |
805 | { | |
806 | gcc_assert (!cinsn); | |
807 | ||
808 | op0 = force_operand (op0, NULL_RTX); | |
809 | op1 = force_operand (op1, NULL_RTX); | |
810 | do_compare_rtx_and_jump (op0, op1, comp, 0, | |
1476d1bd MM |
811 | mode, NULL_RTX, NULL, label, -1); |
812 | jump = as_a <rtx_jump_insn *> (get_last_insn ()); | |
813 | jump->set_jump_target (label); | |
da4cfeac RB |
814 | LABEL_NUSES (label)++; |
815 | } | |
816 | add_int_reg_note (jump, REG_BR_PROB, prob); | |
817 | ||
818 | seq = get_insns (); | |
819 | end_sequence (); | |
820 | ||
821 | return seq; | |
822 | } | |
823 | ||
4fc2e37d EB |
824 | /* Unroll LOOP for which we are able to count number of iterations in runtime |
825 | LOOP->LPT_DECISION.TIMES times. The transformation does this (with some | |
a29c7ea6 | 826 | extra care for case n < 0): |
0c20a65f | 827 | |
a29c7ea6 ZD |
828 | for (i = 0; i < n; i++) |
829 | body; | |
0c20a65f | 830 | |
4fc2e37d | 831 | ==> (LOOP->LPT_DECISION.TIMES == 3) |
0c20a65f | 832 | |
a29c7ea6 ZD |
833 | i = 0; |
834 | mod = n % 4; | |
0c20a65f | 835 | |
a29c7ea6 ZD |
836 | switch (mod) |
837 | { | |
838 | case 3: | |
839 | body; i++; | |
840 | case 2: | |
841 | body; i++; | |
842 | case 1: | |
843 | body; i++; | |
844 | case 0: ; | |
845 | } | |
0c20a65f | 846 | |
a29c7ea6 ZD |
847 | while (i < n) |
848 | { | |
849 | body; i++; | |
850 | body; i++; | |
851 | body; i++; | |
852 | body; i++; | |
853 | } | |
854 | */ | |
855 | static void | |
d73be268 | 856 | unroll_loop_runtime_iterations (struct loop *loop) |
a29c7ea6 | 857 | { |
95ecfb26 DM |
858 | rtx old_niter, niter, tmp; |
859 | rtx_insn *init_code, *branch_code; | |
a29c7ea6 | 860 | unsigned i, j, p; |
66f97d31 | 861 | basic_block preheader, *body, swtch, ezc_swtch; |
a29c7ea6 | 862 | int may_exit_copy; |
ee8c1b05 | 863 | unsigned n_peel; |
ee8c1b05 | 864 | edge e; |
a29c7ea6 ZD |
865 | bool extra_zero_check, last_may_exit; |
866 | unsigned max_unroll = loop->lpt_decision.times; | |
50654f6c ZD |
867 | struct niter_desc *desc = get_simple_loop_desc (loop); |
868 | bool exit_at_end = loop_exit_at_end_p (loop); | |
f37a4f14 | 869 | struct opt_info *opt_info = NULL; |
41806d92 | 870 | bool ok; |
b8698a0f | 871 | |
f37a4f14 RE |
872 | if (flag_split_ivs_in_unroller |
873 | || flag_variable_expansion_in_unroller) | |
874 | opt_info = analyze_insns_in_loop (loop); | |
b8698a0f | 875 | |
a29c7ea6 | 876 | /* Remember blocks whose dominators will have to be updated. */ |
ef062b13 | 877 | auto_vec<basic_block> dom_bbs; |
a29c7ea6 ZD |
878 | |
879 | body = get_loop_body (loop); | |
880 | for (i = 0; i < loop->num_nodes; i++) | |
881 | { | |
9771b263 | 882 | vec<basic_block> ldom; |
66f97d31 | 883 | basic_block bb; |
a29c7ea6 | 884 | |
66f97d31 | 885 | ldom = get_dominated_by (CDI_DOMINATORS, body[i]); |
9771b263 | 886 | FOR_EACH_VEC_ELT (ldom, j, bb) |
66f97d31 | 887 | if (!flow_bb_inside_loop_p (loop, bb)) |
9771b263 | 888 | dom_bbs.safe_push (bb); |
a29c7ea6 | 889 | |
9771b263 | 890 | ldom.release (); |
a29c7ea6 ZD |
891 | } |
892 | free (body); | |
893 | ||
50654f6c | 894 | if (!exit_at_end) |
a29c7ea6 ZD |
895 | { |
896 | /* Leave exit in first copy (for explanation why see comment in | |
897 | unroll_loop_constant_iterations). */ | |
898 | may_exit_copy = 0; | |
899 | n_peel = max_unroll - 1; | |
900 | extra_zero_check = true; | |
901 | last_may_exit = false; | |
902 | } | |
903 | else | |
904 | { | |
905 | /* Leave exit in last copy (for explanation why see comment in | |
906 | unroll_loop_constant_iterations). */ | |
907 | may_exit_copy = max_unroll; | |
908 | n_peel = max_unroll; | |
909 | extra_zero_check = false; | |
910 | last_may_exit = true; | |
911 | } | |
912 | ||
913 | /* Get expression for number of iterations. */ | |
914 | start_sequence (); | |
50654f6c ZD |
915 | old_niter = niter = gen_reg_rtx (desc->mode); |
916 | tmp = force_operand (copy_rtx (desc->niter_expr), niter); | |
917 | if (tmp != niter) | |
918 | emit_move_insn (niter, tmp); | |
a29c7ea6 ZD |
919 | |
920 | /* Count modulo by ANDing it with max_unroll; we use the fact that | |
921 | the number of unrollings is a power of two, and thus this is correct | |
922 | even if there is overflow in the computation. */ | |
50654f6c | 923 | niter = expand_simple_binop (desc->mode, AND, |
2f1cd2eb | 924 | niter, gen_int_mode (max_unroll, desc->mode), |
a29c7ea6 ZD |
925 | NULL_RTX, 0, OPTAB_LIB_WIDEN); |
926 | ||
927 | init_code = get_insns (); | |
928 | end_sequence (); | |
2ed22578 | 929 | unshare_all_rtl_in_chain (init_code); |
a29c7ea6 ZD |
930 | |
931 | /* Precondition the loop. */ | |
598ec7bd | 932 | split_edge_and_insert (loop_preheader_edge (loop), init_code); |
a29c7ea6 | 933 | |
ef062b13 | 934 | auto_vec<edge> remove_edges; |
a29c7ea6 | 935 | |
7ba9e72d | 936 | auto_sbitmap wont_exit (max_unroll + 2); |
a29c7ea6 ZD |
937 | |
938 | /* Peel the first copy of loop body (almost always we must leave exit test | |
939 | here; the only exception is when we have extra zero check and the number | |
50654f6c ZD |
940 | of iterations is reliable. Also record the place of (possible) extra |
941 | zero check. */ | |
f61e445a | 942 | bitmap_clear (wont_exit); |
50654f6c ZD |
943 | if (extra_zero_check |
944 | && !desc->noloop_assumptions) | |
d7c028c0 | 945 | bitmap_set_bit (wont_exit, 1); |
a29c7ea6 | 946 | ezc_swtch = loop_preheader_edge (loop)->src; |
41806d92 | 947 | ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop), |
d73be268 | 948 | 1, wont_exit, desc->out_edge, |
ee8c1b05 | 949 | &remove_edges, |
41806d92 NS |
950 | DLTHE_FLAG_UPDATE_FREQ); |
951 | gcc_assert (ok); | |
a29c7ea6 ZD |
952 | |
953 | /* Record the place where switch will be built for preconditioning. */ | |
598ec7bd | 954 | swtch = split_edge (loop_preheader_edge (loop)); |
a29c7ea6 ZD |
955 | |
956 | for (i = 0; i < n_peel; i++) | |
957 | { | |
958 | /* Peel the copy. */ | |
f61e445a | 959 | bitmap_clear (wont_exit); |
a29c7ea6 | 960 | if (i != n_peel - 1 || !last_may_exit) |
d7c028c0 | 961 | bitmap_set_bit (wont_exit, 1); |
41806d92 | 962 | ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop), |
d73be268 | 963 | 1, wont_exit, desc->out_edge, |
ee8c1b05 | 964 | &remove_edges, |
41806d92 NS |
965 | DLTHE_FLAG_UPDATE_FREQ); |
966 | gcc_assert (ok); | |
a29c7ea6 | 967 | |
91f4cfe3 ZD |
968 | /* Create item for switch. */ |
969 | j = n_peel - i - (extra_zero_check ? 0 : 1); | |
970 | p = REG_BR_PROB_BASE / (i + 2); | |
971 | ||
598ec7bd | 972 | preheader = split_edge (loop_preheader_edge (loop)); |
50654f6c | 973 | branch_code = compare_and_jump_seq (copy_rtx (niter), GEN_INT (j), EQ, |
41806d92 | 974 | block_label (preheader), p, |
95ecfb26 | 975 | NULL); |
91f4cfe3 | 976 | |
7d93d987 ZD |
977 | /* We rely on the fact that the compare and jump cannot be optimized out, |
978 | and hence the cfg we create is correct. */ | |
979 | gcc_assert (branch_code != NULL_RTX); | |
980 | ||
598ec7bd | 981 | swtch = split_edge_and_insert (single_pred_edge (swtch), branch_code); |
d47cc544 | 982 | set_immediate_dominator (CDI_DOMINATORS, preheader, swtch); |
f335184d | 983 | single_succ_edge (swtch)->probability = REG_BR_PROB_BASE - p; |
91f4cfe3 | 984 | e = make_edge (swtch, preheader, |
c5cbcccf | 985 | single_succ_edge (swtch)->flags & EDGE_IRREDUCIBLE_LOOP); |
e3a8f1fa | 986 | e->count = RDIV (preheader->count * REG_BR_PROB_BASE, p); |
91f4cfe3 | 987 | e->probability = p; |
a29c7ea6 ZD |
988 | } |
989 | ||
990 | if (extra_zero_check) | |
991 | { | |
992 | /* Add branch for zero iterations. */ | |
993 | p = REG_BR_PROB_BASE / (max_unroll + 1); | |
994 | swtch = ezc_swtch; | |
598ec7bd | 995 | preheader = split_edge (loop_preheader_edge (loop)); |
50654f6c | 996 | branch_code = compare_and_jump_seq (copy_rtx (niter), const0_rtx, EQ, |
41806d92 | 997 | block_label (preheader), p, |
95ecfb26 | 998 | NULL); |
7d93d987 | 999 | gcc_assert (branch_code != NULL_RTX); |
a29c7ea6 | 1000 | |
598ec7bd | 1001 | swtch = split_edge_and_insert (single_succ_edge (swtch), branch_code); |
d47cc544 | 1002 | set_immediate_dominator (CDI_DOMINATORS, preheader, swtch); |
c5cbcccf | 1003 | single_succ_edge (swtch)->probability = REG_BR_PROB_BASE - p; |
72b8d451 | 1004 | e = make_edge (swtch, preheader, |
c5cbcccf | 1005 | single_succ_edge (swtch)->flags & EDGE_IRREDUCIBLE_LOOP); |
e3a8f1fa | 1006 | e->count = RDIV (preheader->count * REG_BR_PROB_BASE, p); |
a29c7ea6 ZD |
1007 | e->probability = p; |
1008 | } | |
1009 | ||
1010 | /* Recount dominators for outer blocks. */ | |
66f97d31 | 1011 | iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, false); |
a29c7ea6 ZD |
1012 | |
1013 | /* And unroll loop. */ | |
1014 | ||
f61e445a | 1015 | bitmap_ones (wont_exit); |
d7c028c0 | 1016 | bitmap_clear_bit (wont_exit, may_exit_copy); |
f37a4f14 | 1017 | opt_info_start_duplication (opt_info); |
b8698a0f | 1018 | |
41806d92 | 1019 | ok = duplicate_loop_to_header_edge (loop, loop_latch_edge (loop), |
d73be268 | 1020 | max_unroll, |
41806d92 | 1021 | wont_exit, desc->out_edge, |
ee8c1b05 | 1022 | &remove_edges, |
7f7b1718 JH |
1023 | DLTHE_FLAG_UPDATE_FREQ |
1024 | | (opt_info | |
1025 | ? DLTHE_RECORD_COPY_NUMBER | |
1026 | : 0)); | |
41806d92 | 1027 | gcc_assert (ok); |
b8698a0f | 1028 | |
f37a4f14 | 1029 | if (opt_info) |
113d659a | 1030 | { |
f37a4f14 RE |
1031 | apply_opt_in_copies (opt_info, max_unroll, true, true); |
1032 | free_opt_info (opt_info); | |
113d659a ZD |
1033 | } |
1034 | ||
50654f6c ZD |
1035 | if (exit_at_end) |
1036 | { | |
6580ee77 | 1037 | basic_block exit_block = get_bb_copy (desc->in_edge->src); |
41806d92 NS |
1038 | /* Find a new in and out edge; they are in the last copy we have |
1039 | made. */ | |
b8698a0f | 1040 | |
628f6a4e | 1041 | if (EDGE_SUCC (exit_block, 0)->dest == desc->out_edge->dest) |
50654f6c | 1042 | { |
628f6a4e BE |
1043 | desc->out_edge = EDGE_SUCC (exit_block, 0); |
1044 | desc->in_edge = EDGE_SUCC (exit_block, 1); | |
50654f6c ZD |
1045 | } |
1046 | else | |
1047 | { | |
628f6a4e BE |
1048 | desc->out_edge = EDGE_SUCC (exit_block, 1); |
1049 | desc->in_edge = EDGE_SUCC (exit_block, 0); | |
50654f6c ZD |
1050 | } |
1051 | } | |
1052 | ||
a29c7ea6 | 1053 | /* Remove the edges. */ |
9771b263 | 1054 | FOR_EACH_VEC_ELT (remove_edges, i, e) |
ee8c1b05 | 1055 | remove_path (e); |
a29c7ea6 | 1056 | |
50654f6c ZD |
1057 | /* We must be careful when updating the number of iterations due to |
1058 | preconditioning and the fact that the value must be valid at entry | |
1059 | of the loop. After passing through the above code, we see that | |
1060 | the correct new number of iterations is this: */ | |
113d659a | 1061 | gcc_assert (!desc->const_iter); |
50654f6c | 1062 | desc->niter_expr = |
41806d92 | 1063 | simplify_gen_binary (UDIV, desc->mode, old_niter, |
69a59f0f | 1064 | gen_int_mode (max_unroll + 1, desc->mode)); |
e3a8f1fa | 1065 | loop->nb_iterations_upper_bound |
807e902e | 1066 | = wi::udiv_trunc (loop->nb_iterations_upper_bound, max_unroll + 1); |
e3a8f1fa JH |
1067 | if (loop->any_estimate) |
1068 | loop->nb_iterations_estimate | |
807e902e | 1069 | = wi::udiv_trunc (loop->nb_iterations_estimate, max_unroll + 1); |
105e29c5 JH |
1070 | if (loop->any_likely_upper_bound) |
1071 | loop->nb_iterations_likely_upper_bound | |
1072 | = wi::udiv_trunc (loop->nb_iterations_likely_upper_bound, max_unroll + 1); | |
50654f6c ZD |
1073 | if (exit_at_end) |
1074 | { | |
1075 | desc->niter_expr = | |
1076 | simplify_gen_binary (MINUS, desc->mode, desc->niter_expr, const1_rtx); | |
1077 | desc->noloop_assumptions = NULL_RTX; | |
e3a8f1fa JH |
1078 | --loop->nb_iterations_upper_bound; |
1079 | if (loop->any_estimate | |
807e902e | 1080 | && loop->nb_iterations_estimate != 0) |
e3a8f1fa JH |
1081 | --loop->nb_iterations_estimate; |
1082 | else | |
1083 | loop->any_estimate = false; | |
105e29c5 JH |
1084 | if (loop->any_likely_upper_bound |
1085 | && loop->nb_iterations_likely_upper_bound != 0) | |
1086 | --loop->nb_iterations_likely_upper_bound; | |
1087 | else | |
1088 | loop->any_likely_upper_bound = false; | |
50654f6c ZD |
1089 | } |
1090 | ||
c263766c RH |
1091 | if (dump_file) |
1092 | fprintf (dump_file, | |
1093 | ";; Unrolled loop %d times, counting # of iterations " | |
1094 | "in runtime, %i insns\n", | |
a29c7ea6 ZD |
1095 | max_unroll, num_loop_insns (loop)); |
1096 | } | |
0c20a65f | 1097 | |
a29c7ea6 ZD |
1098 | /* Decide whether to unroll LOOP stupidly and how much. */ |
1099 | static void | |
d47cc544 | 1100 | decide_unroll_stupid (struct loop *loop, int flags) |
a29c7ea6 ZD |
1101 | { |
1102 | unsigned nunroll, nunroll_by_av, i; | |
50654f6c | 1103 | struct niter_desc *desc; |
807e902e | 1104 | widest_int iterations; |
a29c7ea6 ZD |
1105 | |
1106 | if (!(flags & UAP_UNROLL_ALL)) | |
1107 | { | |
1108 | /* We were not asked to, just return back silently. */ | |
1109 | return; | |
1110 | } | |
1111 | ||
c263766c RH |
1112 | if (dump_file) |
1113 | fprintf (dump_file, "\n;; Considering unrolling loop stupidly\n"); | |
a29c7ea6 ZD |
1114 | |
1115 | /* nunroll = total number of copies of the original loop body in | |
1116 | unrolled loop (i.e. if it is 2, we have to duplicate loop body once. */ | |
1117 | nunroll = PARAM_VALUE (PARAM_MAX_UNROLLED_INSNS) / loop->ninsns; | |
c263766c RH |
1118 | nunroll_by_av |
1119 | = PARAM_VALUE (PARAM_MAX_AVERAGE_UNROLLED_INSNS) / loop->av_ninsns; | |
a29c7ea6 ZD |
1120 | if (nunroll > nunroll_by_av) |
1121 | nunroll = nunroll_by_av; | |
1122 | if (nunroll > (unsigned) PARAM_VALUE (PARAM_MAX_UNROLL_TIMES)) | |
1123 | nunroll = PARAM_VALUE (PARAM_MAX_UNROLL_TIMES); | |
1124 | ||
40ac4f73 CB |
1125 | if (targetm.loop_unroll_adjust) |
1126 | nunroll = targetm.loop_unroll_adjust (nunroll, loop); | |
1127 | ||
a29c7ea6 ZD |
1128 | /* Skip big loops. */ |
1129 | if (nunroll <= 1) | |
1130 | { | |
c263766c RH |
1131 | if (dump_file) |
1132 | fprintf (dump_file, ";; Not considering loop, is too big\n"); | |
a29c7ea6 ZD |
1133 | return; |
1134 | } | |
1135 | ||
1136 | /* Check for simple loops. */ | |
50654f6c | 1137 | desc = get_simple_loop_desc (loop); |
a29c7ea6 ZD |
1138 | |
1139 | /* Check simpleness. */ | |
50654f6c | 1140 | if (desc->simple_p && !desc->assumptions) |
a29c7ea6 | 1141 | { |
c263766c RH |
1142 | if (dump_file) |
1143 | fprintf (dump_file, ";; The loop is simple\n"); | |
a29c7ea6 ZD |
1144 | return; |
1145 | } | |
1146 | ||
1147 | /* Do not unroll loops with branches inside -- it increases number | |
6acf25e4 JH |
1148 | of mispredicts. |
1149 | TODO: this heuristic needs tunning; call inside the loop body | |
1150 | is also relatively good reason to not unroll. */ | |
50654f6c | 1151 | if (num_loop_branches (loop) > 1) |
a29c7ea6 | 1152 | { |
c263766c RH |
1153 | if (dump_file) |
1154 | fprintf (dump_file, ";; Not unrolling, contains branches\n"); | |
a29c7ea6 ZD |
1155 | return; |
1156 | } | |
1157 | ||
73367f92 | 1158 | /* Check whether the loop rolls. */ |
71343877 | 1159 | if ((get_estimated_loop_iterations (loop, &iterations) |
8c383600 | 1160 | || get_likely_max_loop_iterations (loop, &iterations)) |
807e902e | 1161 | && wi::ltu_p (iterations, 2 * nunroll)) |
a29c7ea6 | 1162 | { |
c263766c RH |
1163 | if (dump_file) |
1164 | fprintf (dump_file, ";; Not unrolling loop, doesn't roll\n"); | |
a29c7ea6 ZD |
1165 | return; |
1166 | } | |
1167 | ||
1168 | /* Success. Now force nunroll to be power of 2, as it seems that this | |
e0bb17a8 | 1169 | improves results (partially because of better alignments, partially |
a29c7ea6 | 1170 | because of some dark magic). */ |
50654f6c ZD |
1171 | for (i = 1; 2 * i <= nunroll; i *= 2) |
1172 | continue; | |
a29c7ea6 ZD |
1173 | |
1174 | loop->lpt_decision.decision = LPT_UNROLL_STUPID; | |
1175 | loop->lpt_decision.times = i - 1; | |
1176 | } | |
1177 | ||
4fc2e37d EB |
1178 | /* Unroll a LOOP LOOP->LPT_DECISION.TIMES times. The transformation does this: |
1179 | ||
a29c7ea6 ZD |
1180 | while (cond) |
1181 | body; | |
1182 | ||
4fc2e37d | 1183 | ==> (LOOP->LPT_DECISION.TIMES == 3) |
a29c7ea6 ZD |
1184 | |
1185 | while (cond) | |
1186 | { | |
1187 | body; | |
1188 | if (!cond) break; | |
1189 | body; | |
1190 | if (!cond) break; | |
1191 | body; | |
1192 | if (!cond) break; | |
1193 | body; | |
1194 | } | |
1195 | */ | |
1196 | static void | |
d73be268 | 1197 | unroll_loop_stupid (struct loop *loop) |
a29c7ea6 | 1198 | { |
a29c7ea6 | 1199 | unsigned nunroll = loop->lpt_decision.times; |
50654f6c | 1200 | struct niter_desc *desc = get_simple_loop_desc (loop); |
f37a4f14 | 1201 | struct opt_info *opt_info = NULL; |
41806d92 | 1202 | bool ok; |
b8698a0f | 1203 | |
f37a4f14 RE |
1204 | if (flag_split_ivs_in_unroller |
1205 | || flag_variable_expansion_in_unroller) | |
1206 | opt_info = analyze_insns_in_loop (loop); | |
b8698a0f | 1207 | |
7ba9e72d | 1208 | auto_sbitmap wont_exit (nunroll + 1); |
f61e445a | 1209 | bitmap_clear (wont_exit); |
f37a4f14 | 1210 | opt_info_start_duplication (opt_info); |
b8698a0f | 1211 | |
41806d92 | 1212 | ok = duplicate_loop_to_header_edge (loop, loop_latch_edge (loop), |
d73be268 | 1213 | nunroll, wont_exit, |
ee8c1b05 | 1214 | NULL, NULL, |
7f7b1718 JH |
1215 | DLTHE_FLAG_UPDATE_FREQ |
1216 | | (opt_info | |
1217 | ? DLTHE_RECORD_COPY_NUMBER | |
1218 | : 0)); | |
41806d92 | 1219 | gcc_assert (ok); |
b8698a0f | 1220 | |
f37a4f14 | 1221 | if (opt_info) |
113d659a | 1222 | { |
f37a4f14 RE |
1223 | apply_opt_in_copies (opt_info, nunroll, true, true); |
1224 | free_opt_info (opt_info); | |
113d659a ZD |
1225 | } |
1226 | ||
50654f6c ZD |
1227 | if (desc->simple_p) |
1228 | { | |
1229 | /* We indeed may get here provided that there are nontrivial assumptions | |
1230 | for a loop to be really simple. We could update the counts, but the | |
1231 | problem is that we are unable to decide which exit will be taken | |
1232 | (not really true in case the number of iterations is constant, | |
1aa95df7 | 1233 | but no one will do anything with this information, so we do not |
50654f6c ZD |
1234 | worry about it). */ |
1235 | desc->simple_p = false; | |
1236 | } | |
1237 | ||
c263766c RH |
1238 | if (dump_file) |
1239 | fprintf (dump_file, ";; Unrolled loop %d times, %i insns\n", | |
a29c7ea6 ZD |
1240 | nunroll, num_loop_insns (loop)); |
1241 | } | |
113d659a | 1242 | |
60c48e4c AO |
1243 | /* Returns true if REG is referenced in one nondebug insn in LOOP. |
1244 | Set *DEBUG_USES to the number of debug insns that reference the | |
1245 | variable. */ | |
f37a4f14 | 1246 | |
dd637013 | 1247 | static bool |
60c48e4c AO |
1248 | referenced_in_one_insn_in_loop_p (struct loop *loop, rtx reg, |
1249 | int *debug_uses) | |
f37a4f14 RE |
1250 | { |
1251 | basic_block *body, bb; | |
1252 | unsigned i; | |
1253 | int count_ref = 0; | |
95ecfb26 | 1254 | rtx_insn *insn; |
b8698a0f L |
1255 | |
1256 | body = get_loop_body (loop); | |
f37a4f14 RE |
1257 | for (i = 0; i < loop->num_nodes; i++) |
1258 | { | |
1259 | bb = body[i]; | |
b8698a0f | 1260 | |
f37a4f14 | 1261 | FOR_BB_INSNS (bb, insn) |
60c48e4c AO |
1262 | if (!rtx_referenced_p (reg, insn)) |
1263 | continue; | |
1264 | else if (DEBUG_INSN_P (insn)) | |
1265 | ++*debug_uses; | |
1266 | else if (++count_ref > 1) | |
1267 | break; | |
f37a4f14 | 1268 | } |
60c48e4c | 1269 | free (body); |
f37a4f14 RE |
1270 | return (count_ref == 1); |
1271 | } | |
1272 | ||
60c48e4c AO |
1273 | /* Reset the DEBUG_USES debug insns in LOOP that reference REG. */ |
1274 | ||
1275 | static void | |
1276 | reset_debug_uses_in_loop (struct loop *loop, rtx reg, int debug_uses) | |
1277 | { | |
1278 | basic_block *body, bb; | |
1279 | unsigned i; | |
95ecfb26 | 1280 | rtx_insn *insn; |
60c48e4c AO |
1281 | |
1282 | body = get_loop_body (loop); | |
1283 | for (i = 0; debug_uses && i < loop->num_nodes; i++) | |
1284 | { | |
1285 | bb = body[i]; | |
1286 | ||
1287 | FOR_BB_INSNS (bb, insn) | |
1288 | if (!DEBUG_INSN_P (insn) || !rtx_referenced_p (reg, insn)) | |
1289 | continue; | |
1290 | else | |
1291 | { | |
1292 | validate_change (insn, &INSN_VAR_LOCATION_LOC (insn), | |
1293 | gen_rtx_UNKNOWN_VAR_LOC (), 0); | |
1294 | if (!--debug_uses) | |
1295 | break; | |
1296 | } | |
1297 | } | |
1298 | free (body); | |
1299 | } | |
1300 | ||
f37a4f14 | 1301 | /* Determine whether INSN contains an accumulator |
b8698a0f | 1302 | which can be expanded into separate copies, |
f37a4f14 | 1303 | one for each copy of the LOOP body. |
b8698a0f | 1304 | |
f37a4f14 RE |
1305 | for (i = 0 ; i < n; i++) |
1306 | sum += a[i]; | |
b8698a0f | 1307 | |
f37a4f14 | 1308 | ==> |
b8698a0f | 1309 | |
f37a4f14 RE |
1310 | sum += a[i] |
1311 | .... | |
1312 | i = i+1; | |
1313 | sum1 += a[i] | |
1314 | .... | |
1315 | i = i+1 | |
1316 | sum2 += a[i]; | |
1317 | .... | |
1318 | ||
b8698a0f L |
1319 | Return NULL if INSN contains no opportunity for expansion of accumulator. |
1320 | Otherwise, allocate a VAR_TO_EXPAND structure, fill it with the relevant | |
f37a4f14 RE |
1321 | information and return a pointer to it. |
1322 | */ | |
1323 | ||
1324 | static struct var_to_expand * | |
95ecfb26 | 1325 | analyze_insn_to_expand_var (struct loop *loop, rtx_insn *insn) |
f37a4f14 | 1326 | { |
531e5376 | 1327 | rtx set, dest, src; |
f37a4f14 | 1328 | struct var_to_expand *ves; |
76fd2caa | 1329 | unsigned accum_pos; |
531e5376 | 1330 | enum rtx_code code; |
60c48e4c | 1331 | int debug_uses = 0; |
76fd2caa | 1332 | |
f37a4f14 RE |
1333 | set = single_set (insn); |
1334 | if (!set) | |
1335 | return NULL; | |
b8698a0f | 1336 | |
f37a4f14 RE |
1337 | dest = SET_DEST (set); |
1338 | src = SET_SRC (set); | |
531e5376 | 1339 | code = GET_CODE (src); |
b8698a0f | 1340 | |
531e5376 | 1341 | if (code != PLUS && code != MINUS && code != MULT && code != FMA) |
f37a4f14 | 1342 | return NULL; |
f2dd440f | 1343 | |
531e5376 RH |
1344 | if (FLOAT_MODE_P (GET_MODE (dest))) |
1345 | { | |
1346 | if (!flag_associative_math) | |
1347 | return NULL; | |
1348 | /* In the case of FMA, we're also changing the rounding. */ | |
1349 | if (code == FMA && !flag_unsafe_math_optimizations) | |
1350 | return NULL; | |
1351 | } | |
1352 | ||
f2dd440f SB |
1353 | /* Hmm, this is a bit paradoxical. We know that INSN is a valid insn |
1354 | in MD. But if there is no optab to generate the insn, we can not | |
1355 | perform the variable expansion. This can happen if an MD provides | |
1356 | an insn but not a named pattern to generate it, for example to avoid | |
1357 | producing code that needs additional mode switches like for x87/mmx. | |
1358 | ||
1359 | So we check have_insn_for which looks for an optab for the operation | |
1360 | in SRC. If it doesn't exist, we can't perform the expansion even | |
1361 | though INSN is valid. */ | |
531e5376 | 1362 | if (!have_insn_for (code, GET_MODE (src))) |
f2dd440f SB |
1363 | return NULL; |
1364 | ||
f37a4f14 RE |
1365 | if (!REG_P (dest) |
1366 | && !(GET_CODE (dest) == SUBREG | |
1367 | && REG_P (SUBREG_REG (dest)))) | |
1368 | return NULL; | |
b8698a0f | 1369 | |
531e5376 RH |
1370 | /* Find the accumulator use within the operation. */ |
1371 | if (code == FMA) | |
1372 | { | |
1373 | /* We only support accumulation via FMA in the ADD position. */ | |
1374 | if (!rtx_equal_p (dest, XEXP (src, 2))) | |
1375 | return NULL; | |
1376 | accum_pos = 2; | |
1377 | } | |
1378 | else if (rtx_equal_p (dest, XEXP (src, 0))) | |
76fd2caa | 1379 | accum_pos = 0; |
531e5376 RH |
1380 | else if (rtx_equal_p (dest, XEXP (src, 1))) |
1381 | { | |
1382 | /* The method of expansion that we are using; which includes the | |
1383 | initialization of the expansions with zero and the summation of | |
1384 | the expansions at the end of the computation will yield wrong | |
1385 | results for (x = something - x) thus avoid using it in that case. */ | |
1386 | if (code == MINUS) | |
1387 | return NULL; | |
1388 | accum_pos = 1; | |
1389 | } | |
76fd2caa RE |
1390 | else |
1391 | return NULL; | |
1392 | ||
531e5376 RH |
1393 | /* It must not otherwise be used. */ |
1394 | if (code == FMA) | |
1395 | { | |
1396 | if (rtx_referenced_p (dest, XEXP (src, 0)) | |
1397 | || rtx_referenced_p (dest, XEXP (src, 1))) | |
1398 | return NULL; | |
1399 | } | |
1400 | else if (rtx_referenced_p (dest, XEXP (src, 1 - accum_pos))) | |
f37a4f14 | 1401 | return NULL; |
b8698a0f | 1402 | |
531e5376 | 1403 | /* It must be used in exactly one insn. */ |
60c48e4c | 1404 | if (!referenced_in_one_insn_in_loop_p (loop, dest, &debug_uses)) |
f37a4f14 | 1405 | return NULL; |
b8698a0f | 1406 | |
c1c5a431 | 1407 | if (dump_file) |
531e5376 RH |
1408 | { |
1409 | fprintf (dump_file, "\n;; Expanding Accumulator "); | |
1410 | print_rtl (dump_file, dest); | |
1411 | fprintf (dump_file, "\n"); | |
1412 | } | |
c1c5a431 | 1413 | |
60c48e4c AO |
1414 | if (debug_uses) |
1415 | /* Instead of resetting the debug insns, we could replace each | |
1416 | debug use in the loop with the sum or product of all expanded | |
1417 | accummulators. Since we'll only know of all expansions at the | |
1418 | end, we'd have to keep track of which vars_to_expand a debug | |
1419 | insn in the loop references, take note of each copy of the | |
1420 | debug insn during unrolling, and when it's all done, compute | |
1421 | the sum or product of each variable and adjust the original | |
1422 | debug insn and each copy thereof. What a pain! */ | |
1423 | reset_debug_uses_in_loop (loop, dest, debug_uses); | |
1424 | ||
f37a4f14 | 1425 | /* Record the accumulator to expand. */ |
5ed6ace5 | 1426 | ves = XNEW (struct var_to_expand); |
f37a4f14 | 1427 | ves->insn = insn; |
f37a4f14 | 1428 | ves->reg = copy_rtx (dest); |
9771b263 | 1429 | ves->var_expansions.create (1); |
a9f6ecee | 1430 | ves->next = NULL; |
f37a4f14 RE |
1431 | ves->op = GET_CODE (src); |
1432 | ves->expansion_count = 0; | |
1433 | ves->reuse_expansion = 0; | |
b8698a0f | 1434 | return ves; |
f37a4f14 RE |
1435 | } |
1436 | ||
113d659a | 1437 | /* Determine whether there is an induction variable in INSN that |
b8698a0f | 1438 | we would like to split during unrolling. |
f37a4f14 RE |
1439 | |
1440 | I.e. replace | |
1441 | ||
1442 | i = i + 1; | |
1443 | ... | |
1444 | i = i + 1; | |
1445 | ... | |
1446 | i = i + 1; | |
1447 | ... | |
1448 | ||
1449 | type chains by | |
1450 | ||
1451 | i0 = i + 1 | |
1452 | ... | |
1453 | i = i0 + 1 | |
1454 | ... | |
1455 | i = i0 + 2 | |
1456 | ... | |
1457 | ||
b8698a0f | 1458 | Return NULL if INSN contains no interesting IVs. Otherwise, allocate |
f37a4f14 | 1459 | an IV_TO_SPLIT structure, fill it with the relevant information and return a |
113d659a ZD |
1460 | pointer to it. */ |
1461 | ||
1462 | static struct iv_to_split * | |
1b20d55a | 1463 | analyze_iv_to_split_insn (rtx_insn *insn) |
113d659a ZD |
1464 | { |
1465 | rtx set, dest; | |
1466 | struct rtx_iv iv; | |
1467 | struct iv_to_split *ivts; | |
41806d92 | 1468 | bool ok; |
113d659a ZD |
1469 | |
1470 | /* For now we just split the basic induction variables. Later this may be | |
1471 | extended for example by selecting also addresses of memory references. */ | |
1472 | set = single_set (insn); | |
1473 | if (!set) | |
1474 | return NULL; | |
1475 | ||
1476 | dest = SET_DEST (set); | |
1477 | if (!REG_P (dest)) | |
1478 | return NULL; | |
1479 | ||
1480 | if (!biv_p (insn, dest)) | |
1481 | return NULL; | |
1482 | ||
03fd2215 | 1483 | ok = iv_analyze_result (insn, dest, &iv); |
4dc7782d JL |
1484 | |
1485 | /* This used to be an assert under the assumption that if biv_p returns | |
1486 | true that iv_analyze_result must also return true. However, that | |
1487 | assumption is not strictly correct as evidenced by pr25569. | |
1488 | ||
1489 | Returning NULL when iv_analyze_result returns false is safe and | |
1490 | avoids the problems in pr25569 until the iv_analyze_* routines | |
1491 | can be fixed, which is apparently hard and time consuming | |
1492 | according to their author. */ | |
1493 | if (! ok) | |
1494 | return NULL; | |
113d659a ZD |
1495 | |
1496 | if (iv.step == const0_rtx | |
1497 | || iv.mode != iv.extend_mode) | |
1498 | return NULL; | |
1499 | ||
1500 | /* Record the insn to split. */ | |
5ed6ace5 | 1501 | ivts = XNEW (struct iv_to_split); |
113d659a | 1502 | ivts->insn = insn; |
4a0c3fde | 1503 | ivts->orig_var = dest; |
113d659a ZD |
1504 | ivts->base_var = NULL_RTX; |
1505 | ivts->step = iv.step; | |
a9f6ecee | 1506 | ivts->next = NULL; |
b8698a0f | 1507 | |
113d659a ZD |
1508 | return ivts; |
1509 | } | |
1510 | ||
f37a4f14 RE |
1511 | /* Determines which of insns in LOOP can be optimized. |
1512 | Return a OPT_INFO struct with the relevant hash tables filled | |
1513 | with all insns to be optimized. The FIRST_NEW_BLOCK field | |
113d659a ZD |
1514 | is undefined for the return value. */ |
1515 | ||
f37a4f14 RE |
1516 | static struct opt_info * |
1517 | analyze_insns_in_loop (struct loop *loop) | |
113d659a ZD |
1518 | { |
1519 | basic_block *body, bb; | |
ca83d385 | 1520 | unsigned i; |
5ed6ace5 | 1521 | struct opt_info *opt_info = XCNEW (struct opt_info); |
1b20d55a | 1522 | rtx_insn *insn; |
f37a4f14 RE |
1523 | struct iv_to_split *ivts = NULL; |
1524 | struct var_to_expand *ves = NULL; | |
4a8fb1a1 LC |
1525 | iv_to_split **slot1; |
1526 | var_to_expand **slot2; | |
9771b263 | 1527 | vec<edge> edges = get_loop_exit_edges (loop); |
ca83d385 | 1528 | edge exit; |
f37a4f14 | 1529 | bool can_apply = false; |
b8698a0f | 1530 | |
113d659a ZD |
1531 | iv_analysis_loop_init (loop); |
1532 | ||
1533 | body = get_loop_body (loop); | |
f37a4f14 RE |
1534 | |
1535 | if (flag_split_ivs_in_unroller) | |
a9f6ecee | 1536 | { |
c203e8a7 TS |
1537 | opt_info->insns_to_split |
1538 | = new hash_table<iv_split_hasher> (5 * loop->num_nodes); | |
a9f6ecee AO |
1539 | opt_info->iv_to_split_head = NULL; |
1540 | opt_info->iv_to_split_tail = &opt_info->iv_to_split_head; | |
1541 | } | |
b8698a0f | 1542 | |
f37a4f14 | 1543 | /* Record the loop exit bb and loop preheader before the unrolling. */ |
598ec7bd | 1544 | opt_info->loop_preheader = loop_preheader_edge (loop)->src; |
b8698a0f | 1545 | |
9771b263 | 1546 | if (edges.length () == 1) |
f37a4f14 | 1547 | { |
9771b263 | 1548 | exit = edges[0]; |
ca83d385 ZD |
1549 | if (!(exit->flags & EDGE_COMPLEX)) |
1550 | { | |
1551 | opt_info->loop_exit = split_edge (exit); | |
1552 | can_apply = true; | |
1553 | } | |
f37a4f14 | 1554 | } |
b8698a0f | 1555 | |
f37a4f14 RE |
1556 | if (flag_variable_expansion_in_unroller |
1557 | && can_apply) | |
a9f6ecee | 1558 | { |
c203e8a7 TS |
1559 | opt_info->insns_with_var_to_expand |
1560 | = new hash_table<var_expand_hasher> (5 * loop->num_nodes); | |
a9f6ecee AO |
1561 | opt_info->var_to_expand_head = NULL; |
1562 | opt_info->var_to_expand_tail = &opt_info->var_to_expand_head; | |
1563 | } | |
b8698a0f | 1564 | |
113d659a ZD |
1565 | for (i = 0; i < loop->num_nodes; i++) |
1566 | { | |
1567 | bb = body[i]; | |
1568 | if (!dominated_by_p (CDI_DOMINATORS, loop->latch, bb)) | |
1569 | continue; | |
1570 | ||
1571 | FOR_BB_INSNS (bb, insn) | |
f37a4f14 RE |
1572 | { |
1573 | if (!INSN_P (insn)) | |
1574 | continue; | |
b8698a0f | 1575 | |
c203e8a7 | 1576 | if (opt_info->insns_to_split) |
f37a4f14 | 1577 | ivts = analyze_iv_to_split_insn (insn); |
b8698a0f | 1578 | |
f37a4f14 RE |
1579 | if (ivts) |
1580 | { | |
c203e8a7 | 1581 | slot1 = opt_info->insns_to_split->find_slot (ivts, INSERT); |
a9f6ecee | 1582 | gcc_assert (*slot1 == NULL); |
f37a4f14 | 1583 | *slot1 = ivts; |
a9f6ecee AO |
1584 | *opt_info->iv_to_split_tail = ivts; |
1585 | opt_info->iv_to_split_tail = &ivts->next; | |
f37a4f14 RE |
1586 | continue; |
1587 | } | |
b8698a0f | 1588 | |
c203e8a7 | 1589 | if (opt_info->insns_with_var_to_expand) |
f37a4f14 | 1590 | ves = analyze_insn_to_expand_var (loop, insn); |
b8698a0f | 1591 | |
f37a4f14 RE |
1592 | if (ves) |
1593 | { | |
c203e8a7 | 1594 | slot2 = opt_info->insns_with_var_to_expand->find_slot (ves, INSERT); |
a9f6ecee | 1595 | gcc_assert (*slot2 == NULL); |
f37a4f14 | 1596 | *slot2 = ves; |
a9f6ecee AO |
1597 | *opt_info->var_to_expand_tail = ves; |
1598 | opt_info->var_to_expand_tail = &ves->next; | |
f37a4f14 RE |
1599 | } |
1600 | } | |
113d659a | 1601 | } |
b8698a0f | 1602 | |
9771b263 | 1603 | edges.release (); |
113d659a | 1604 | free (body); |
f37a4f14 | 1605 | return opt_info; |
113d659a ZD |
1606 | } |
1607 | ||
1608 | /* Called just before loop duplication. Records start of duplicated area | |
f37a4f14 | 1609 | to OPT_INFO. */ |
113d659a | 1610 | |
b8698a0f | 1611 | static void |
f37a4f14 | 1612 | opt_info_start_duplication (struct opt_info *opt_info) |
113d659a | 1613 | { |
f37a4f14 | 1614 | if (opt_info) |
8b1c6fd7 | 1615 | opt_info->first_new_block = last_basic_block_for_fn (cfun); |
113d659a ZD |
1616 | } |
1617 | ||
1618 | /* Determine the number of iterations between initialization of the base | |
1619 | variable and the current copy (N_COPY). N_COPIES is the total number | |
1620 | of newly created copies. UNROLLING is true if we are unrolling | |
1621 | (not peeling) the loop. */ | |
1622 | ||
1623 | static unsigned | |
1624 | determine_split_iv_delta (unsigned n_copy, unsigned n_copies, bool unrolling) | |
1625 | { | |
1626 | if (unrolling) | |
1627 | { | |
1628 | /* If we are unrolling, initialization is done in the original loop | |
1629 | body (number 0). */ | |
1630 | return n_copy; | |
1631 | } | |
1632 | else | |
1633 | { | |
1634 | /* If we are peeling, the copy in that the initialization occurs has | |
1635 | number 1. The original loop (number 0) is the last. */ | |
1636 | if (n_copy) | |
1637 | return n_copy - 1; | |
1638 | else | |
1639 | return n_copies; | |
1640 | } | |
1641 | } | |
1642 | ||
a9f6ecee | 1643 | /* Allocate basic variable for the induction variable chain. */ |
113d659a | 1644 | |
a9f6ecee AO |
1645 | static void |
1646 | allocate_basic_variable (struct iv_to_split *ivts) | |
113d659a | 1647 | { |
8cab83f0 | 1648 | rtx expr = SET_SRC (single_set (ivts->insn)); |
113d659a ZD |
1649 | |
1650 | ivts->base_var = gen_reg_rtx (GET_MODE (expr)); | |
113d659a ZD |
1651 | } |
1652 | ||
1653 | /* Insert initialization of basic variable of IVTS before INSN, taking | |
1654 | the initial value from INSN. */ | |
1655 | ||
1656 | static void | |
95ecfb26 | 1657 | insert_base_initialization (struct iv_to_split *ivts, rtx_insn *insn) |
113d659a | 1658 | { |
8cab83f0 | 1659 | rtx expr = copy_rtx (SET_SRC (single_set (insn))); |
95ecfb26 | 1660 | rtx_insn *seq; |
113d659a ZD |
1661 | |
1662 | start_sequence (); | |
1663 | expr = force_operand (expr, ivts->base_var); | |
1664 | if (expr != ivts->base_var) | |
1665 | emit_move_insn (ivts->base_var, expr); | |
1666 | seq = get_insns (); | |
1667 | end_sequence (); | |
1668 | ||
1669 | emit_insn_before (seq, insn); | |
1670 | } | |
1671 | ||
1672 | /* Replace the use of induction variable described in IVTS in INSN | |
1673 | by base variable + DELTA * step. */ | |
1674 | ||
1675 | static void | |
95ecfb26 | 1676 | split_iv (struct iv_to_split *ivts, rtx_insn *insn, unsigned delta) |
113d659a | 1677 | { |
95ecfb26 DM |
1678 | rtx expr, *loc, incr, var; |
1679 | rtx_insn *seq; | |
ef4bddc2 | 1680 | machine_mode mode = GET_MODE (ivts->base_var); |
113d659a ZD |
1681 | rtx src, dest, set; |
1682 | ||
1683 | /* Construct base + DELTA * step. */ | |
1684 | if (!delta) | |
1685 | expr = ivts->base_var; | |
1686 | else | |
1687 | { | |
1688 | incr = simplify_gen_binary (MULT, mode, | |
1689 | ivts->step, gen_int_mode (delta, mode)); | |
1690 | expr = simplify_gen_binary (PLUS, GET_MODE (ivts->base_var), | |
1691 | ivts->base_var, incr); | |
1692 | } | |
1693 | ||
1694 | /* Figure out where to do the replacement. */ | |
8cab83f0 | 1695 | loc = &SET_SRC (single_set (insn)); |
113d659a ZD |
1696 | |
1697 | /* If we can make the replacement right away, we're done. */ | |
1698 | if (validate_change (insn, loc, expr, 0)) | |
1699 | return; | |
1700 | ||
1701 | /* Otherwise, force EXPR into a register and try again. */ | |
1702 | start_sequence (); | |
1703 | var = gen_reg_rtx (mode); | |
1704 | expr = force_operand (expr, var); | |
1705 | if (expr != var) | |
1706 | emit_move_insn (var, expr); | |
1707 | seq = get_insns (); | |
1708 | end_sequence (); | |
1709 | emit_insn_before (seq, insn); | |
b8698a0f | 1710 | |
113d659a ZD |
1711 | if (validate_change (insn, loc, var, 0)) |
1712 | return; | |
1713 | ||
1714 | /* The last chance. Try recreating the assignment in insn | |
1715 | completely from scratch. */ | |
1716 | set = single_set (insn); | |
1717 | gcc_assert (set); | |
1718 | ||
1719 | start_sequence (); | |
1720 | *loc = var; | |
1721 | src = copy_rtx (SET_SRC (set)); | |
1722 | dest = copy_rtx (SET_DEST (set)); | |
1723 | src = force_operand (src, dest); | |
1724 | if (src != dest) | |
1725 | emit_move_insn (dest, src); | |
1726 | seq = get_insns (); | |
1727 | end_sequence (); | |
b8698a0f | 1728 | |
113d659a ZD |
1729 | emit_insn_before (seq, insn); |
1730 | delete_insn (insn); | |
1731 | } | |
1732 | ||
113d659a | 1733 | |
2cd0e9f4 | 1734 | /* Return one expansion of the accumulator recorded in struct VE. */ |
113d659a | 1735 | |
f37a4f14 RE |
1736 | static rtx |
1737 | get_expansion (struct var_to_expand *ve) | |
1738 | { | |
1739 | rtx reg; | |
b8698a0f | 1740 | |
f37a4f14 RE |
1741 | if (ve->reuse_expansion == 0) |
1742 | reg = ve->reg; | |
1743 | else | |
9771b263 | 1744 | reg = ve->var_expansions[ve->reuse_expansion - 1]; |
b8698a0f | 1745 | |
9771b263 | 1746 | if (ve->var_expansions.length () == (unsigned) ve->reuse_expansion) |
f37a4f14 | 1747 | ve->reuse_expansion = 0; |
b8698a0f | 1748 | else |
f37a4f14 | 1749 | ve->reuse_expansion++; |
b8698a0f | 1750 | |
f37a4f14 RE |
1751 | return reg; |
1752 | } | |
113d659a | 1753 | |
113d659a | 1754 | |
b8698a0f | 1755 | /* Given INSN replace the uses of the accumulator recorded in VE |
f37a4f14 RE |
1756 | with a new register. */ |
1757 | ||
1758 | static void | |
95ecfb26 | 1759 | expand_var_during_unrolling (struct var_to_expand *ve, rtx_insn *insn) |
f37a4f14 RE |
1760 | { |
1761 | rtx new_reg, set; | |
1762 | bool really_new_expansion = false; | |
b8698a0f | 1763 | |
f37a4f14 | 1764 | set = single_set (insn); |
b5e624c6 | 1765 | gcc_assert (set); |
b8698a0f | 1766 | |
f37a4f14 RE |
1767 | /* Generate a new register only if the expansion limit has not been |
1768 | reached. Else reuse an already existing expansion. */ | |
1769 | if (PARAM_VALUE (PARAM_MAX_VARIABLE_EXPANSIONS) > ve->expansion_count) | |
1770 | { | |
1771 | really_new_expansion = true; | |
1772 | new_reg = gen_reg_rtx (GET_MODE (ve->reg)); | |
1773 | } | |
1774 | else | |
1775 | new_reg = get_expansion (ve); | |
1776 | ||
6e74642b | 1777 | validate_replace_rtx_group (SET_DEST (set), new_reg, insn); |
f37a4f14 RE |
1778 | if (apply_change_group ()) |
1779 | if (really_new_expansion) | |
1780 | { | |
9771b263 | 1781 | ve->var_expansions.safe_push (new_reg); |
f37a4f14 RE |
1782 | ve->expansion_count++; |
1783 | } | |
1784 | } | |
1785 | ||
a9f6ecee AO |
1786 | /* Initialize the variable expansions in loop preheader. PLACE is the |
1787 | loop-preheader basic block where the initialization of the | |
1788 | expansions should take place. The expansions are initialized with | |
1789 | (-0) when the operation is plus or minus to honor sign zero. This | |
1790 | way we can prevent cases where the sign of the final result is | |
1791 | effected by the sign of the expansion. Here is an example to | |
1792 | demonstrate this: | |
b8698a0f | 1793 | |
290358f7 RE |
1794 | for (i = 0 ; i < n; i++) |
1795 | sum += something; | |
1796 | ||
1797 | ==> | |
1798 | ||
1799 | sum += something | |
1800 | .... | |
1801 | i = i+1; | |
1802 | sum1 += something | |
1803 | .... | |
1804 | i = i+1 | |
1805 | sum2 += something; | |
1806 | .... | |
b8698a0f | 1807 | |
290358f7 RE |
1808 | When SUM is initialized with -zero and SOMETHING is also -zero; the |
1809 | final result of sum should be -zero thus the expansions sum1 and sum2 | |
1810 | should be initialized with -zero as well (otherwise we will get +zero | |
1811 | as the final result). */ | |
f37a4f14 | 1812 | |
a9f6ecee AO |
1813 | static void |
1814 | insert_var_expansion_initialization (struct var_to_expand *ve, | |
1815 | basic_block place) | |
f37a4f14 | 1816 | { |
95ecfb26 DM |
1817 | rtx_insn *seq; |
1818 | rtx var, zero_init; | |
f37a4f14 | 1819 | unsigned i; |
ef4bddc2 | 1820 | machine_mode mode = GET_MODE (ve->reg); |
290358f7 RE |
1821 | bool honor_signed_zero_p = HONOR_SIGNED_ZEROS (mode); |
1822 | ||
9771b263 | 1823 | if (ve->var_expansions.length () == 0) |
a9f6ecee | 1824 | return; |
b8698a0f | 1825 | |
f37a4f14 | 1826 | start_sequence (); |
531e5376 RH |
1827 | switch (ve->op) |
1828 | { | |
1829 | case FMA: | |
1830 | /* Note that we only accumulate FMA via the ADD operand. */ | |
1831 | case PLUS: | |
1832 | case MINUS: | |
9771b263 | 1833 | FOR_EACH_VEC_ELT (ve->var_expansions, i, var) |
531e5376 RH |
1834 | { |
1835 | if (honor_signed_zero_p) | |
1836 | zero_init = simplify_gen_unary (NEG, mode, CONST0_RTX (mode), mode); | |
1837 | else | |
1838 | zero_init = CONST0_RTX (mode); | |
1839 | emit_move_insn (var, zero_init); | |
1840 | } | |
1841 | break; | |
1842 | ||
1843 | case MULT: | |
9771b263 | 1844 | FOR_EACH_VEC_ELT (ve->var_expansions, i, var) |
531e5376 RH |
1845 | { |
1846 | zero_init = CONST1_RTX (GET_MODE (var)); | |
1847 | emit_move_insn (var, zero_init); | |
1848 | } | |
1849 | break; | |
1850 | ||
1851 | default: | |
1852 | gcc_unreachable (); | |
1853 | } | |
b8698a0f | 1854 | |
f37a4f14 RE |
1855 | seq = get_insns (); |
1856 | end_sequence (); | |
b8698a0f | 1857 | |
6e74642b | 1858 | emit_insn_after (seq, BB_END (place)); |
f37a4f14 RE |
1859 | } |
1860 | ||
a9f6ecee AO |
1861 | /* Combine the variable expansions at the loop exit. PLACE is the |
1862 | loop exit basic block where the summation of the expansions should | |
1863 | take place. */ | |
f37a4f14 | 1864 | |
a9f6ecee AO |
1865 | static void |
1866 | combine_var_copies_in_loop_exit (struct var_to_expand *ve, basic_block place) | |
f37a4f14 | 1867 | { |
f37a4f14 | 1868 | rtx sum = ve->reg; |
95ecfb26 DM |
1869 | rtx expr, var; |
1870 | rtx_insn *seq, *insn; | |
f37a4f14 RE |
1871 | unsigned i; |
1872 | ||
9771b263 | 1873 | if (ve->var_expansions.length () == 0) |
a9f6ecee | 1874 | return; |
b8698a0f | 1875 | |
f37a4f14 | 1876 | start_sequence (); |
531e5376 RH |
1877 | switch (ve->op) |
1878 | { | |
1879 | case FMA: | |
1880 | /* Note that we only accumulate FMA via the ADD operand. */ | |
1881 | case PLUS: | |
1882 | case MINUS: | |
9771b263 | 1883 | FOR_EACH_VEC_ELT (ve->var_expansions, i, var) |
531e5376 RH |
1884 | sum = simplify_gen_binary (PLUS, GET_MODE (ve->reg), var, sum); |
1885 | break; | |
1886 | ||
1887 | case MULT: | |
9771b263 | 1888 | FOR_EACH_VEC_ELT (ve->var_expansions, i, var) |
531e5376 RH |
1889 | sum = simplify_gen_binary (MULT, GET_MODE (ve->reg), var, sum); |
1890 | break; | |
1891 | ||
1892 | default: | |
1893 | gcc_unreachable (); | |
1894 | } | |
b8698a0f | 1895 | |
f37a4f14 RE |
1896 | expr = force_operand (sum, ve->reg); |
1897 | if (expr != ve->reg) | |
1898 | emit_move_insn (ve->reg, expr); | |
1899 | seq = get_insns (); | |
1900 | end_sequence (); | |
b8698a0f | 1901 | |
f37a4f14 RE |
1902 | insn = BB_HEAD (place); |
1903 | while (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
1904 | insn = NEXT_INSN (insn); | |
1905 | ||
1906 | emit_insn_after (seq, insn); | |
f37a4f14 RE |
1907 | } |
1908 | ||
4a0c3fde SB |
1909 | /* Strip away REG_EQUAL notes for IVs we're splitting. |
1910 | ||
1911 | Updating REG_EQUAL notes for IVs we split is tricky: We | |
1912 | cannot tell until after unrolling, DF-rescanning, and liveness | |
1913 | updating, whether an EQ_USE is reached by the split IV while | |
1914 | the IV reg is still live. See PR55006. | |
1915 | ||
1916 | ??? We cannot use remove_reg_equal_equiv_notes_for_regno, | |
1917 | because RTL loop-iv requires us to defer rescanning insns and | |
1918 | any notes attached to them. So resort to old techniques... */ | |
1919 | ||
1920 | static void | |
95ecfb26 | 1921 | maybe_strip_eq_note_for_split_iv (struct opt_info *opt_info, rtx_insn *insn) |
4a0c3fde SB |
1922 | { |
1923 | struct iv_to_split *ivts; | |
1924 | rtx note = find_reg_equal_equiv_note (insn); | |
1925 | if (! note) | |
1926 | return; | |
1927 | for (ivts = opt_info->iv_to_split_head; ivts; ivts = ivts->next) | |
1928 | if (reg_mentioned_p (ivts->orig_var, note)) | |
1929 | { | |
1930 | remove_note (insn, note); | |
1931 | return; | |
1932 | } | |
1933 | } | |
1934 | ||
b8698a0f L |
1935 | /* Apply loop optimizations in loop copies using the |
1936 | data which gathered during the unrolling. Structure | |
f37a4f14 | 1937 | OPT_INFO record that data. |
b8698a0f | 1938 | |
113d659a ZD |
1939 | UNROLLING is true if we unrolled (not peeled) the loop. |
1940 | REWRITE_ORIGINAL_BODY is true if we should also rewrite the original body of | |
1941 | the loop (as it should happen in complete unrolling, but not in ordinary | |
1942 | peeling of the loop). */ | |
1943 | ||
1944 | static void | |
b8698a0f L |
1945 | apply_opt_in_copies (struct opt_info *opt_info, |
1946 | unsigned n_copies, bool unrolling, | |
f37a4f14 | 1947 | bool rewrite_original_loop) |
113d659a ZD |
1948 | { |
1949 | unsigned i, delta; | |
1950 | basic_block bb, orig_bb; | |
95ecfb26 | 1951 | rtx_insn *insn, *orig_insn, *next; |
113d659a | 1952 | struct iv_to_split ivts_templ, *ivts; |
f37a4f14 | 1953 | struct var_to_expand ve_templ, *ves; |
b8698a0f | 1954 | |
113d659a ZD |
1955 | /* Sanity check -- we need to put initialization in the original loop |
1956 | body. */ | |
1957 | gcc_assert (!unrolling || rewrite_original_loop); | |
b8698a0f | 1958 | |
113d659a | 1959 | /* Allocate the basic variables (i0). */ |
c203e8a7 | 1960 | if (opt_info->insns_to_split) |
a9f6ecee AO |
1961 | for (ivts = opt_info->iv_to_split_head; ivts; ivts = ivts->next) |
1962 | allocate_basic_variable (ivts); | |
b8698a0f | 1963 | |
8b1c6fd7 DM |
1964 | for (i = opt_info->first_new_block; |
1965 | i < (unsigned) last_basic_block_for_fn (cfun); | |
1966 | i++) | |
113d659a | 1967 | { |
06e28de2 | 1968 | bb = BASIC_BLOCK_FOR_FN (cfun, i); |
6580ee77 | 1969 | orig_bb = get_bb_original (bb); |
b8698a0f | 1970 | |
6580ee77 JH |
1971 | /* bb->aux holds position in copy sequence initialized by |
1972 | duplicate_loop_to_header_edge. */ | |
1973 | delta = determine_split_iv_delta ((size_t)bb->aux, n_copies, | |
113d659a | 1974 | unrolling); |
7f7b1718 | 1975 | bb->aux = 0; |
113d659a | 1976 | orig_insn = BB_HEAD (orig_bb); |
4a0c3fde | 1977 | FOR_BB_INSNS_SAFE (bb, insn, next) |
f37a4f14 | 1978 | { |
0397b965 JJ |
1979 | if (!INSN_P (insn) |
1980 | || (DEBUG_INSN_P (insn) | |
1981 | && TREE_CODE (INSN_VAR_LOCATION_DECL (insn)) == LABEL_DECL)) | |
f37a4f14 | 1982 | continue; |
b8698a0f | 1983 | |
0397b965 JJ |
1984 | while (!INSN_P (orig_insn) |
1985 | || (DEBUG_INSN_P (orig_insn) | |
1986 | && (TREE_CODE (INSN_VAR_LOCATION_DECL (orig_insn)) | |
1987 | == LABEL_DECL))) | |
f37a4f14 | 1988 | orig_insn = NEXT_INSN (orig_insn); |
b8698a0f | 1989 | |
f37a4f14 RE |
1990 | ivts_templ.insn = orig_insn; |
1991 | ve_templ.insn = orig_insn; | |
b8698a0f | 1992 | |
f37a4f14 | 1993 | /* Apply splitting iv optimization. */ |
c203e8a7 | 1994 | if (opt_info->insns_to_split) |
f37a4f14 | 1995 | { |
4a0c3fde SB |
1996 | maybe_strip_eq_note_for_split_iv (opt_info, insn); |
1997 | ||
c203e8a7 | 1998 | ivts = opt_info->insns_to_split->find (&ivts_templ); |
b8698a0f | 1999 | |
f37a4f14 RE |
2000 | if (ivts) |
2001 | { | |
21f868a2 ZD |
2002 | gcc_assert (GET_CODE (PATTERN (insn)) |
2003 | == GET_CODE (PATTERN (orig_insn))); | |
b8698a0f | 2004 | |
f37a4f14 RE |
2005 | if (!delta) |
2006 | insert_base_initialization (ivts, insn); | |
2007 | split_iv (ivts, insn, delta); | |
2008 | } | |
2009 | } | |
2010 | /* Apply variable expansion optimization. */ | |
c203e8a7 | 2011 | if (unrolling && opt_info->insns_with_var_to_expand) |
f37a4f14 | 2012 | { |
d3bfe4de | 2013 | ves = (struct var_to_expand *) |
c203e8a7 | 2014 | opt_info->insns_with_var_to_expand->find (&ve_templ); |
f37a4f14 | 2015 | if (ves) |
b8698a0f | 2016 | { |
21f868a2 ZD |
2017 | gcc_assert (GET_CODE (PATTERN (insn)) |
2018 | == GET_CODE (PATTERN (orig_insn))); | |
f37a4f14 RE |
2019 | expand_var_during_unrolling (ves, insn); |
2020 | } | |
2021 | } | |
2022 | orig_insn = NEXT_INSN (orig_insn); | |
2023 | } | |
113d659a ZD |
2024 | } |
2025 | ||
2026 | if (!rewrite_original_loop) | |
2027 | return; | |
b8698a0f | 2028 | |
f37a4f14 | 2029 | /* Initialize the variable expansions in the loop preheader |
b8698a0f | 2030 | and take care of combining them at the loop exit. */ |
c203e8a7 | 2031 | if (opt_info->insns_with_var_to_expand) |
f37a4f14 | 2032 | { |
a9f6ecee AO |
2033 | for (ves = opt_info->var_to_expand_head; ves; ves = ves->next) |
2034 | insert_var_expansion_initialization (ves, opt_info->loop_preheader); | |
2035 | for (ves = opt_info->var_to_expand_head; ves; ves = ves->next) | |
2036 | combine_var_copies_in_loop_exit (ves, opt_info->loop_exit); | |
f37a4f14 | 2037 | } |
b8698a0f | 2038 | |
113d659a ZD |
2039 | /* Rewrite also the original loop body. Find them as originals of the blocks |
2040 | in the last copied iteration, i.e. those that have | |
6580ee77 | 2041 | get_bb_copy (get_bb_original (bb)) == bb. */ |
8b1c6fd7 DM |
2042 | for (i = opt_info->first_new_block; |
2043 | i < (unsigned) last_basic_block_for_fn (cfun); | |
2044 | i++) | |
113d659a | 2045 | { |
06e28de2 | 2046 | bb = BASIC_BLOCK_FOR_FN (cfun, i); |
6580ee77 JH |
2047 | orig_bb = get_bb_original (bb); |
2048 | if (get_bb_copy (orig_bb) != bb) | |
113d659a | 2049 | continue; |
b8698a0f | 2050 | |
113d659a ZD |
2051 | delta = determine_split_iv_delta (0, n_copies, unrolling); |
2052 | for (orig_insn = BB_HEAD (orig_bb); | |
f37a4f14 RE |
2053 | orig_insn != NEXT_INSN (BB_END (bb)); |
2054 | orig_insn = next) | |
2055 | { | |
2056 | next = NEXT_INSN (orig_insn); | |
b8698a0f | 2057 | |
f37a4f14 RE |
2058 | if (!INSN_P (orig_insn)) |
2059 | continue; | |
b8698a0f | 2060 | |
f37a4f14 | 2061 | ivts_templ.insn = orig_insn; |
c203e8a7 | 2062 | if (opt_info->insns_to_split) |
f37a4f14 | 2063 | { |
4a0c3fde SB |
2064 | maybe_strip_eq_note_for_split_iv (opt_info, orig_insn); |
2065 | ||
d3bfe4de | 2066 | ivts = (struct iv_to_split *) |
c203e8a7 | 2067 | opt_info->insns_to_split->find (&ivts_templ); |
f37a4f14 RE |
2068 | if (ivts) |
2069 | { | |
2070 | if (!delta) | |
2071 | insert_base_initialization (ivts, orig_insn); | |
2072 | split_iv (ivts, orig_insn, delta); | |
2073 | continue; | |
2074 | } | |
2075 | } | |
b8698a0f | 2076 | |
f37a4f14 RE |
2077 | } |
2078 | } | |
2079 | } | |
113d659a | 2080 | |
f37a4f14 | 2081 | /* Release OPT_INFO. */ |
113d659a ZD |
2082 | |
2083 | static void | |
f37a4f14 | 2084 | free_opt_info (struct opt_info *opt_info) |
113d659a | 2085 | { |
c203e8a7 TS |
2086 | delete opt_info->insns_to_split; |
2087 | opt_info->insns_to_split = NULL; | |
2088 | if (opt_info->insns_with_var_to_expand) | |
f37a4f14 | 2089 | { |
a9f6ecee AO |
2090 | struct var_to_expand *ves; |
2091 | ||
2092 | for (ves = opt_info->var_to_expand_head; ves; ves = ves->next) | |
9771b263 | 2093 | ves->var_expansions.release (); |
c203e8a7 TS |
2094 | delete opt_info->insns_with_var_to_expand; |
2095 | opt_info->insns_with_var_to_expand = NULL; | |
f37a4f14 RE |
2096 | } |
2097 | free (opt_info); | |
113d659a | 2098 | } |