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c836de3f | 1 | /* Loop unrolling. |
aad93da1 | 2 | Copyright (C) 2002-2017 Free Software Foundation, Inc. |
ad5201d0 | 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 | |
8c4c00c1 | 8 | Software Foundation; either version 3, or (at your option) any later |
ad5201d0 | 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 | |
8c4c00c1 | 17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
ad5201d0 | 19 | |
20 | #include "config.h" | |
21 | #include "system.h" | |
22 | #include "coretypes.h" | |
9ef16211 | 23 | #include "backend.h" |
7c29e30e | 24 | #include "target.h" |
ad5201d0 | 25 | #include "rtl.h" |
41a8aa41 | 26 | #include "tree.h" |
7c29e30e | 27 | #include "cfghooks.h" |
ad7b10a2 | 28 | #include "memmodel.h" |
7c29e30e | 29 | #include "optabs.h" |
30 | #include "emit-rtl.h" | |
31 | #include "recog.h" | |
886c1262 | 32 | #include "profile.h" |
94ea8568 | 33 | #include "cfgrtl.h" |
ad5201d0 | 34 | #include "cfgloop.h" |
ad5201d0 | 35 | #include "params.h" |
d53441c8 | 36 | #include "dojump.h" |
ad5201d0 | 37 | #include "expr.h" |
b9ed1410 | 38 | #include "dumpfile.h" |
ad5201d0 | 39 | |
c836de3f | 40 | /* This pass performs loop unrolling. We only perform this |
41 | optimization on innermost loops (with single exception) because | |
ad5201d0 | 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 | |
917bbcab | 44 | of code, better code to optimize for further passes and in some cases |
ad5201d0 | 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 | ||
ad5201d0 | 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 | |
c836de3f | 62 | control how much we unroll. |
ad5201d0 | 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 | ||
a9989fb4 | 69 | /* Information about induction variables to split. */ |
70 | ||
71 | struct iv_to_split | |
72 | { | |
222dc1d3 | 73 | rtx_insn *insn; /* The insn in that the induction variable occurs. */ |
ef770610 | 74 | rtx orig_var; /* The variable (register) for the IV before split. */ |
a9989fb4 | 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. */ | |
b635a1a3 | 78 | struct iv_to_split *next; /* Next entry in walking order. */ |
a9989fb4 | 79 | }; |
80 | ||
375bb675 | 81 | /* Information about accumulators to expand. */ |
82 | ||
83 | struct var_to_expand | |
84 | { | |
222dc1d3 | 85 | rtx_insn *insn; /* The insn in that the variable expansion occurs. */ |
dac49aa5 | 86 | rtx reg; /* The accumulator which is expanded. */ |
f1f41a6c | 87 | vec<rtx> var_expansions; /* The copies of the accumulator which is expanded. */ |
b635a1a3 | 88 | struct var_to_expand *next; /* Next entry in walking order. */ |
48e1416a | 89 | enum rtx_code op; /* The type of the accumulation - addition, subtraction |
375bb675 | 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 | |
48e1416a | 93 | the accumulator. If REUSE_EXPANSION is 0 reuse |
94 | the original accumulator. Else use | |
375bb675 | 95 | var_expansions[REUSE_EXPANSION - 1]. */ |
96 | }; | |
97 | ||
d9dd21a8 | 98 | /* Hashtable helper for iv_to_split. */ |
99 | ||
298e7f9a | 100 | struct iv_split_hasher : free_ptr_hash <iv_to_split> |
d9dd21a8 | 101 | { |
9969c043 | 102 | static inline hashval_t hash (const iv_to_split *); |
103 | static inline bool equal (const iv_to_split *, const iv_to_split *); | |
d9dd21a8 | 104 | }; |
105 | ||
106 | ||
107 | /* A hash function for information about insns to split. */ | |
108 | ||
109 | inline hashval_t | |
9969c043 | 110 | iv_split_hasher::hash (const iv_to_split *ivts) |
d9dd21a8 | 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 | |
9969c043 | 118 | iv_split_hasher::equal (const iv_to_split *i1, const iv_to_split *i2) |
d9dd21a8 | 119 | { |
120 | return i1->insn == i2->insn; | |
121 | } | |
122 | ||
123 | /* Hashtable helper for iv_to_split. */ | |
124 | ||
298e7f9a | 125 | struct var_expand_hasher : free_ptr_hash <var_to_expand> |
d9dd21a8 | 126 | { |
9969c043 | 127 | static inline hashval_t hash (const var_to_expand *); |
128 | static inline bool equal (const var_to_expand *, const var_to_expand *); | |
d9dd21a8 | 129 | }; |
130 | ||
131 | /* Return a hash for VES. */ | |
132 | ||
133 | inline hashval_t | |
9969c043 | 134 | var_expand_hasher::hash (const var_to_expand *ves) |
d9dd21a8 | 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 | |
9969c043 | 142 | var_expand_hasher::equal (const var_to_expand *i1, const var_to_expand *i2) |
d9dd21a8 | 143 | { |
144 | return i1->insn == i2->insn; | |
145 | } | |
146 | ||
375bb675 | 147 | /* Information about optimization applied in |
148 | the unrolled loop. */ | |
149 | ||
150 | struct opt_info | |
a9989fb4 | 151 | { |
c1f445d2 | 152 | hash_table<iv_split_hasher> *insns_to_split; /* A hashtable of insns to |
d9dd21a8 | 153 | split. */ |
b635a1a3 | 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. */ | |
c1f445d2 | 156 | hash_table<var_expand_hasher> *insns_with_var_to_expand; /* A hashtable of |
d9dd21a8 | 157 | insns with accumulators to expand. */ |
b635a1a3 | 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. */ | |
375bb675 | 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. */ | |
a9989fb4 | 164 | }; |
165 | ||
0051c76a | 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); | |
7194de72 | 169 | static void unroll_loop_stupid (struct loop *); |
c836de3f | 170 | static void decide_unrolling (int); |
7194de72 | 171 | static void unroll_loop_constant_iterations (struct loop *); |
172 | static void unroll_loop_runtime_iterations (struct loop *); | |
375bb675 | 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 *); | |
222dc1d3 | 177 | static struct var_to_expand *analyze_insn_to_expand_var (struct loop*, rtx_insn *); |
3b3940d7 | 178 | static bool referenced_in_one_insn_in_loop_p (struct loop *, rtx, int *); |
3eeb4f9a | 179 | static struct iv_to_split *analyze_iv_to_split_insn (rtx_insn *); |
222dc1d3 | 180 | static void expand_var_during_unrolling (struct var_to_expand *, rtx_insn *); |
b635a1a3 | 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); | |
375bb675 | 185 | static rtx get_expansion (struct var_to_expand *); |
ad5201d0 | 186 | |
c836de3f | 187 | /* Emit a message summarizing the unroll that will be |
f55775aa | 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 | |
c836de3f | 192 | report_unroll (struct loop *loop, location_t locus) |
f55775aa | 193 | { |
ffdaf8f1 | 194 | dump_flags_t report_flags = MSG_OPTIMIZED_LOCATIONS | TDF_DETAILS; |
f55775aa | 195 | |
830b796a | 196 | if (loop->lpt_decision.decision == LPT_NONE) |
197 | return; | |
198 | ||
f55775aa | 199 | if (!dump_enabled_p ()) |
200 | return; | |
201 | ||
c836de3f | 202 | dump_printf_loc (report_flags, locus, |
203 | "loop unrolled %d times", | |
204 | loop->lpt_decision.times); | |
db9cef39 | 205 | if (profile_info && loop->header->count.initialized_p ()) |
f55775aa | 206 | dump_printf (report_flags, |
c836de3f | 207 | " (header execution count %d)", |
db9cef39 | 208 | (int)loop->header->count.to_gcov_type ()); |
f55775aa | 209 | |
210 | dump_printf (report_flags, "\n"); | |
211 | } | |
212 | ||
c836de3f | 213 | /* Decide whether unroll loops and how much. */ |
ad5201d0 | 214 | static void |
c836de3f | 215 | decide_unrolling (int flags) |
ad5201d0 | 216 | { |
17519ba0 | 217 | struct loop *loop; |
ad5201d0 | 218 | |
219 | /* Scan the loops, inner ones first. */ | |
f21d4d00 | 220 | FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) |
ad5201d0 | 221 | { |
ad5201d0 | 222 | loop->lpt_decision.decision = LPT_NONE; |
f55775aa | 223 | location_t locus = get_loop_location (loop); |
ad5201d0 | 224 | |
f55775aa | 225 | if (dump_enabled_p ()) |
ffdaf8f1 | 226 | dump_printf_loc (MSG_NOTE, locus, |
f55775aa | 227 | ";; *** Considering loop %d at BB %d for " |
c836de3f | 228 | "unrolling ***\n", |
f55775aa | 229 | loop->num, loop->header->index); |
ad5201d0 | 230 | |
231 | /* Do not peel cold areas. */ | |
0bfd8d5c | 232 | if (optimize_loop_for_size_p (loop)) |
ad5201d0 | 233 | { |
450d042a | 234 | if (dump_file) |
235 | fprintf (dump_file, ";; Not considering loop, cold area\n"); | |
ad5201d0 | 236 | continue; |
237 | } | |
238 | ||
239 | /* Can the loop be manipulated? */ | |
240 | if (!can_duplicate_loop_p (loop)) | |
241 | { | |
450d042a | 242 | if (dump_file) |
243 | fprintf (dump_file, | |
ad5201d0 | 244 | ";; Not considering loop, cannot duplicate\n"); |
ad5201d0 | 245 | continue; |
246 | } | |
247 | ||
248 | /* Skip non-innermost loops. */ | |
249 | if (loop->inner) | |
250 | { | |
450d042a | 251 | if (dump_file) |
252 | fprintf (dump_file, ";; Not considering loop, is not innermost\n"); | |
ad5201d0 | 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 | ||
0051c76a | 262 | decide_unroll_constant_iterations (loop, flags); |
ad5201d0 | 263 | if (loop->lpt_decision.decision == LPT_NONE) |
0051c76a | 264 | decide_unroll_runtime_iterations (loop, flags); |
ad5201d0 | 265 | if (loop->lpt_decision.decision == LPT_NONE) |
0051c76a | 266 | decide_unroll_stupid (loop, flags); |
ad5201d0 | 267 | |
c836de3f | 268 | report_unroll (loop, locus); |
ad5201d0 | 269 | } |
ad5201d0 | 270 | } |
271 | ||
c836de3f | 272 | /* Unroll LOOPS. */ |
273 | void | |
274 | unroll_loops (int flags) | |
ad5201d0 | 275 | { |
c836de3f | 276 | struct loop *loop; |
277 | bool changed = false; | |
ad5201d0 | 278 | |
c836de3f | 279 | /* Now decide rest of unrolling. */ |
280 | decide_unrolling (flags); | |
ad5201d0 | 281 | |
c836de3f | 282 | /* Scan the loops, inner ones first. */ |
283 | FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) | |
ad5201d0 | 284 | { |
c836de3f | 285 | /* And perform the appropriate transformations. */ |
286 | switch (loop->lpt_decision.decision) | |
3ad4992f | 287 | { |
c836de3f | 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 (); | |
ad5201d0 | 304 | } |
ad5201d0 | 305 | } |
306 | ||
c836de3f | 307 | if (changed) |
308 | { | |
309 | calculate_dominance_info (CDI_DOMINATORS); | |
310 | fix_loop_structure (NULL); | |
311 | } | |
3ad4992f | 312 | |
c836de3f | 313 | iv_analysis_done (); |
314 | } | |
ad5201d0 | 315 | |
c836de3f | 316 | /* Check whether exit of the LOOP is at the end of loop body. */ |
3ad4992f | 317 | |
c836de3f | 318 | static bool |
319 | loop_exit_at_end_p (struct loop *loop) | |
ad5201d0 | 320 | { |
f9cce2dc | 321 | struct niter_desc *desc = get_simple_loop_desc (loop); |
c836de3f | 322 | rtx_insn *insn; |
a5414ff5 | 323 | |
c836de3f | 324 | /* We should never have conditional in latch block. */ |
325 | gcc_assert (desc->in_edge->dest != loop->header); | |
48e1416a | 326 | |
c836de3f | 327 | if (desc->in_edge->dest != loop->latch) |
328 | return false; | |
a9989fb4 | 329 | |
c836de3f | 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; | |
a5414ff5 | 335 | } |
ad5201d0 | 336 | |
c836de3f | 337 | return true; |
ad5201d0 | 338 | } |
339 | ||
450d042a | 340 | /* Decide whether to unroll LOOP iterating constant number of times |
341 | and how much. */ | |
f9cce2dc | 342 | |
ad5201d0 | 343 | static void |
0051c76a | 344 | decide_unroll_constant_iterations (struct loop *loop, int flags) |
ad5201d0 | 345 | { |
f9cce2dc | 346 | unsigned nunroll, nunroll_by_av, best_copies, best_unroll = 0, n_copies, i; |
347 | struct niter_desc *desc; | |
5de9d3ed | 348 | widest_int iterations; |
ad5201d0 | 349 | |
350 | if (!(flags & UAP_UNROLL)) | |
351 | { | |
352 | /* We were not asked to, just return back silently. */ | |
353 | return; | |
354 | } | |
355 | ||
450d042a | 356 | if (dump_file) |
357 | fprintf (dump_file, | |
358 | "\n;; Considering unrolling loop with constant " | |
359 | "number of iterations\n"); | |
ad5201d0 | 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; | |
450d042a | 364 | nunroll_by_av |
365 | = PARAM_VALUE (PARAM_MAX_AVERAGE_UNROLLED_INSNS) / loop->av_ninsns; | |
ad5201d0 | 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 | ||
e7f33cf8 | 371 | if (targetm.loop_unroll_adjust) |
372 | nunroll = targetm.loop_unroll_adjust (nunroll, loop); | |
373 | ||
ad5201d0 | 374 | /* Skip big loops. */ |
375 | if (nunroll <= 1) | |
376 | { | |
450d042a | 377 | if (dump_file) |
378 | fprintf (dump_file, ";; Not considering loop, is too big\n"); | |
ad5201d0 | 379 | return; |
380 | } | |
381 | ||
382 | /* Check for simple loops. */ | |
f9cce2dc | 383 | desc = get_simple_loop_desc (loop); |
ad5201d0 | 384 | |
385 | /* Check number of iterations. */ | |
f9cce2dc | 386 | if (!desc->simple_p || !desc->const_iter || desc->assumptions) |
ad5201d0 | 387 | { |
450d042a | 388 | if (dump_file) |
389 | fprintf (dump_file, | |
390 | ";; Unable to prove that the loop iterates constant times\n"); | |
ad5201d0 | 391 | return; |
392 | } | |
393 | ||
c8fbcf58 | 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 | |
f86b328b | 399 | || ((get_estimated_loop_iterations (loop, &iterations) |
53b01069 | 400 | || get_likely_max_loop_iterations (loop, &iterations)) |
796b6678 | 401 | && wi::ltu_p (iterations, 2 * nunroll))) |
ad5201d0 | 402 | { |
450d042a | 403 | if (dump_file) |
404 | fprintf (dump_file, ";; Not unrolling loop, doesn't roll\n"); | |
ad5201d0 | 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 | |
d01481af | 410 | necessary, while still not decreasing the number of unrollings |
ad5201d0 | 411 | too much (at most by 1). */ |
412 | best_copies = 2 * nunroll + 10; | |
413 | ||
414 | i = 2 * nunroll + 2; | |
f9cce2dc | 415 | if (i - 1 >= desc->niter) |
416 | i = desc->niter - 2; | |
ad5201d0 | 417 | |
418 | for (; i >= nunroll - 1; i--) | |
419 | { | |
f9cce2dc | 420 | unsigned exit_mod = desc->niter % (i + 1); |
ad5201d0 | 421 | |
f9cce2dc | 422 | if (!loop_exit_at_end_p (loop)) |
ad5201d0 | 423 | n_copies = exit_mod + i + 1; |
f9cce2dc | 424 | else if (exit_mod != (unsigned) i |
425 | || desc->noloop_assumptions != NULL_RTX) | |
ad5201d0 | 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 | ||
ad5201d0 | 437 | loop->lpt_decision.decision = LPT_UNROLL_CONSTANT; |
438 | loop->lpt_decision.times = best_unroll; | |
439 | } | |
440 | ||
1c18ed19 | 441 | /* Unroll LOOP with constant number of iterations LOOP->LPT_DECISION.TIMES times. |
442 | The transformation does this: | |
3ad4992f | 443 | |
ad5201d0 | 444 | for (i = 0; i < 102; i++) |
445 | body; | |
3ad4992f | 446 | |
1c18ed19 | 447 | ==> (LOOP->LPT_DECISION.TIMES == 3) |
3ad4992f | 448 | |
ad5201d0 | 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 | |
7194de72 | 461 | unroll_loop_constant_iterations (struct loop *loop) |
ad5201d0 | 462 | { |
463 | unsigned HOST_WIDE_INT niter; | |
464 | unsigned exit_mod; | |
f3c40e6d | 465 | unsigned i; |
f3c40e6d | 466 | edge e; |
ad5201d0 | 467 | unsigned max_unroll = loop->lpt_decision.times; |
f9cce2dc | 468 | struct niter_desc *desc = get_simple_loop_desc (loop); |
469 | bool exit_at_end = loop_exit_at_end_p (loop); | |
375bb675 | 470 | struct opt_info *opt_info = NULL; |
a53ff4c1 | 471 | bool ok; |
48e1416a | 472 | |
ad5201d0 | 473 | niter = desc->niter; |
474 | ||
a9989fb4 | 475 | /* Should not get here (such loop should be peeled instead). */ |
476 | gcc_assert (niter > max_unroll + 1); | |
ad5201d0 | 477 | |
478 | exit_mod = niter % (max_unroll + 1); | |
479 | ||
3c6549f8 | 480 | auto_sbitmap wont_exit (max_unroll + 1); |
53c5d9d4 | 481 | bitmap_ones (wont_exit); |
ad5201d0 | 482 | |
c2078b80 | 483 | auto_vec<edge> remove_edges; |
48e1416a | 484 | if (flag_split_ivs_in_unroller |
375bb675 | 485 | || flag_variable_expansion_in_unroller) |
486 | opt_info = analyze_insns_in_loop (loop); | |
48e1416a | 487 | |
f9cce2dc | 488 | if (!exit_at_end) |
ad5201d0 | 489 | { |
f9cce2dc | 490 | /* The exit is not at the end of the loop; leave exit test |
ad5201d0 | 491 | in the first copy, so that the loops that start with test |
492 | of exit condition have continuous body after unrolling. */ | |
493 | ||
450d042a | 494 | if (dump_file) |
1c18ed19 | 495 | fprintf (dump_file, ";; Condition at beginning of loop.\n"); |
ad5201d0 | 496 | |
497 | /* Peel exit_mod iterations. */ | |
08b7917c | 498 | bitmap_clear_bit (wont_exit, 0); |
f9cce2dc | 499 | if (desc->noloop_assumptions) |
08b7917c | 500 | bitmap_clear_bit (wont_exit, 1); |
ad5201d0 | 501 | |
f9cce2dc | 502 | if (exit_mod) |
503 | { | |
375bb675 | 504 | opt_info_start_duplication (opt_info); |
a53ff4c1 | 505 | ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop), |
7194de72 | 506 | exit_mod, |
f9cce2dc | 507 | wont_exit, desc->out_edge, |
f3c40e6d | 508 | &remove_edges, |
75cc36a4 | 509 | DLTHE_FLAG_UPDATE_FREQ |
510 | | (opt_info && exit_mod > 1 | |
511 | ? DLTHE_RECORD_COPY_NUMBER | |
512 | : 0)); | |
a53ff4c1 | 513 | gcc_assert (ok); |
f9cce2dc | 514 | |
375bb675 | 515 | if (opt_info && exit_mod > 1) |
48e1416a | 516 | apply_opt_in_copies (opt_info, exit_mod, false, false); |
517 | ||
f9cce2dc | 518 | desc->noloop_assumptions = NULL_RTX; |
519 | desc->niter -= exit_mod; | |
e913b5cd | 520 | loop->nb_iterations_upper_bound -= exit_mod; |
a9ef9877 | 521 | if (loop->any_estimate |
796b6678 | 522 | && wi::leu_p (exit_mod, loop->nb_iterations_estimate)) |
e913b5cd | 523 | loop->nb_iterations_estimate -= exit_mod; |
a9ef9877 | 524 | else |
525 | loop->any_estimate = false; | |
8e3ffe30 | 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; | |
f9cce2dc | 531 | } |
ad5201d0 | 532 | |
08b7917c | 533 | bitmap_set_bit (wont_exit, 1); |
ad5201d0 | 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 | ||
450d042a | 540 | if (dump_file) |
1c18ed19 | 541 | fprintf (dump_file, ";; Condition at end of loop.\n"); |
ad5201d0 | 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 | |
f9cce2dc | 545 | exit_mod + 1 iterations. */ |
546 | if (exit_mod != max_unroll | |
547 | || desc->noloop_assumptions) | |
ad5201d0 | 548 | { |
08b7917c | 549 | bitmap_clear_bit (wont_exit, 0); |
f9cce2dc | 550 | if (desc->noloop_assumptions) |
08b7917c | 551 | bitmap_clear_bit (wont_exit, 1); |
48e1416a | 552 | |
375bb675 | 553 | opt_info_start_duplication (opt_info); |
a53ff4c1 | 554 | ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop), |
7194de72 | 555 | exit_mod + 1, |
a53ff4c1 | 556 | wont_exit, desc->out_edge, |
f3c40e6d | 557 | &remove_edges, |
75cc36a4 | 558 | DLTHE_FLAG_UPDATE_FREQ |
559 | | (opt_info && exit_mod > 0 | |
560 | ? DLTHE_RECORD_COPY_NUMBER | |
561 | : 0)); | |
a53ff4c1 | 562 | gcc_assert (ok); |
48e1416a | 563 | |
375bb675 | 564 | if (opt_info && exit_mod > 0) |
565 | apply_opt_in_copies (opt_info, exit_mod + 1, false, false); | |
a9989fb4 | 566 | |
f9cce2dc | 567 | desc->niter -= exit_mod + 1; |
e913b5cd | 568 | loop->nb_iterations_upper_bound -= exit_mod + 1; |
a9ef9877 | 569 | if (loop->any_estimate |
796b6678 | 570 | && wi::leu_p (exit_mod + 1, loop->nb_iterations_estimate)) |
e913b5cd | 571 | loop->nb_iterations_estimate -= exit_mod + 1; |
a9ef9877 | 572 | else |
573 | loop->any_estimate = false; | |
8e3ffe30 | 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; | |
f9cce2dc | 579 | desc->noloop_assumptions = NULL_RTX; |
580 | ||
08b7917c | 581 | bitmap_set_bit (wont_exit, 0); |
582 | bitmap_set_bit (wont_exit, 1); | |
ad5201d0 | 583 | } |
584 | ||
08b7917c | 585 | bitmap_clear_bit (wont_exit, max_unroll); |
ad5201d0 | 586 | } |
587 | ||
588 | /* Now unroll the loop. */ | |
48e1416a | 589 | |
375bb675 | 590 | opt_info_start_duplication (opt_info); |
a53ff4c1 | 591 | ok = duplicate_loop_to_header_edge (loop, loop_latch_edge (loop), |
7194de72 | 592 | max_unroll, |
a53ff4c1 | 593 | wont_exit, desc->out_edge, |
f3c40e6d | 594 | &remove_edges, |
75cc36a4 | 595 | DLTHE_FLAG_UPDATE_FREQ |
596 | | (opt_info | |
597 | ? DLTHE_RECORD_COPY_NUMBER | |
598 | : 0)); | |
a53ff4c1 | 599 | gcc_assert (ok); |
ad5201d0 | 600 | |
375bb675 | 601 | if (opt_info) |
a9989fb4 | 602 | { |
375bb675 | 603 | apply_opt_in_copies (opt_info, max_unroll, true, true); |
604 | free_opt_info (opt_info); | |
a9989fb4 | 605 | } |
606 | ||
f9cce2dc | 607 | if (exit_at_end) |
608 | { | |
01020a5f | 609 | basic_block exit_block = get_bb_copy (desc->in_edge->src); |
f9cce2dc | 610 | /* Find a new in and out edge; they are in the last copy we have made. */ |
48e1416a | 611 | |
cd665a06 | 612 | if (EDGE_SUCC (exit_block, 0)->dest == desc->out_edge->dest) |
f9cce2dc | 613 | { |
cd665a06 | 614 | desc->out_edge = EDGE_SUCC (exit_block, 0); |
615 | desc->in_edge = EDGE_SUCC (exit_block, 1); | |
f9cce2dc | 616 | } |
617 | else | |
618 | { | |
cd665a06 | 619 | desc->out_edge = EDGE_SUCC (exit_block, 1); |
620 | desc->in_edge = EDGE_SUCC (exit_block, 0); | |
f9cce2dc | 621 | } |
622 | } | |
623 | ||
624 | desc->niter /= max_unroll + 1; | |
a9ef9877 | 625 | loop->nb_iterations_upper_bound |
796b6678 | 626 | = wi::udiv_trunc (loop->nb_iterations_upper_bound, max_unroll + 1); |
a9ef9877 | 627 | if (loop->any_estimate) |
628 | loop->nb_iterations_estimate | |
796b6678 | 629 | = wi::udiv_trunc (loop->nb_iterations_estimate, max_unroll + 1); |
8e3ffe30 | 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); | |
f9cce2dc | 633 | desc->niter_expr = GEN_INT (desc->niter); |
634 | ||
ad5201d0 | 635 | /* Remove the edges. */ |
f1f41a6c | 636 | FOR_EACH_VEC_ELT (remove_edges, i, e) |
f3c40e6d | 637 | remove_path (e); |
ad5201d0 | 638 | |
450d042a | 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)); | |
ad5201d0 | 643 | } |
644 | ||
645 | /* Decide whether to unroll LOOP iterating runtime computable number of times | |
646 | and how much. */ | |
647 | static void | |
0051c76a | 648 | decide_unroll_runtime_iterations (struct loop *loop, int flags) |
ad5201d0 | 649 | { |
650 | unsigned nunroll, nunroll_by_av, i; | |
f9cce2dc | 651 | struct niter_desc *desc; |
5de9d3ed | 652 | widest_int iterations; |
ad5201d0 | 653 | |
654 | if (!(flags & UAP_UNROLL)) | |
655 | { | |
656 | /* We were not asked to, just return back silently. */ | |
657 | return; | |
658 | } | |
659 | ||
450d042a | 660 | if (dump_file) |
661 | fprintf (dump_file, | |
662 | "\n;; Considering unrolling loop with runtime " | |
663 | "computable number of iterations\n"); | |
ad5201d0 | 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 | ||
9ccaa774 | 674 | if (targetm.loop_unroll_adjust) |
675 | nunroll = targetm.loop_unroll_adjust (nunroll, loop); | |
676 | ||
ad5201d0 | 677 | /* Skip big loops. */ |
678 | if (nunroll <= 1) | |
679 | { | |
450d042a | 680 | if (dump_file) |
681 | fprintf (dump_file, ";; Not considering loop, is too big\n"); | |
ad5201d0 | 682 | return; |
683 | } | |
684 | ||
685 | /* Check for simple loops. */ | |
f9cce2dc | 686 | desc = get_simple_loop_desc (loop); |
ad5201d0 | 687 | |
688 | /* Check simpleness. */ | |
f9cce2dc | 689 | if (!desc->simple_p || desc->assumptions) |
ad5201d0 | 690 | { |
450d042a | 691 | if (dump_file) |
692 | fprintf (dump_file, | |
693 | ";; Unable to prove that the number of iterations " | |
694 | "can be counted in runtime\n"); | |
ad5201d0 | 695 | return; |
696 | } | |
697 | ||
f9cce2dc | 698 | if (desc->const_iter) |
ad5201d0 | 699 | { |
450d042a | 700 | if (dump_file) |
701 | fprintf (dump_file, ";; Loop iterates constant times\n"); | |
ad5201d0 | 702 | return; |
703 | } | |
704 | ||
204a2e45 | 705 | /* Check whether the loop rolls. */ |
f86b328b | 706 | if ((get_estimated_loop_iterations (loop, &iterations) |
53b01069 | 707 | || get_likely_max_loop_iterations (loop, &iterations)) |
796b6678 | 708 | && wi::ltu_p (iterations, 2 * nunroll)) |
ad5201d0 | 709 | { |
450d042a | 710 | if (dump_file) |
711 | fprintf (dump_file, ";; Not unrolling loop, doesn't roll\n"); | |
ad5201d0 | 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. */ | |
f9cce2dc | 717 | for (i = 1; 2 * i <= nunroll; i *= 2) |
718 | continue; | |
ad5201d0 | 719 | |
720 | loop->lpt_decision.decision = LPT_UNROLL_RUNTIME; | |
721 | loop->lpt_decision.times = i - 1; | |
722 | } | |
723 | ||
d6a1bbdb | 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. */ | |
88e6f696 | 727 | |
728 | basic_block | |
222dc1d3 | 729 | split_edge_and_insert (edge e, rtx_insn *insns) |
88e6f696 | 730 | { |
d6a1bbdb | 731 | basic_block bb; |
732 | ||
733 | if (!insns) | |
734 | return NULL; | |
48e1416a | 735 | bb = split_edge (e); |
88e6f696 | 736 | emit_insn_after (insns, BB_END (bb)); |
db1c50be | 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, | |
8b88439e | 743 | the verify_flow_info at the end of the RTL loop passes would fail. |
db1c50be | 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 | ||
88e6f696 | 768 | return bb; |
769 | } | |
770 | ||
b99ab275 | 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 | ||
222dc1d3 | 775 | static rtx_insn * |
f9a00e9e | 776 | compare_and_jump_seq (rtx op0, rtx op1, enum rtx_code comp, |
720cfc43 | 777 | rtx_code_label *label, profile_probability prob, |
778 | rtx_insn *cinsn) | |
b99ab275 | 779 | { |
f9a00e9e | 780 | rtx_insn *seq; |
781 | rtx_jump_insn *jump; | |
222dc1d3 | 782 | rtx cond; |
3754d046 | 783 | machine_mode mode; |
b99ab275 | 784 | |
785 | mode = GET_MODE (op0); | |
786 | if (mode == VOIDmode) | |
787 | mode = GET_MODE (op1); | |
788 | ||
789 | start_sequence (); | |
790 | if (GET_MODE_CLASS (mode) == MODE_CC) | |
791 | { | |
792 | /* A hack -- there seems to be no easy generic way how to make a | |
793 | conditional jump from a ccmode comparison. */ | |
794 | gcc_assert (cinsn); | |
795 | cond = XEXP (SET_SRC (pc_set (cinsn)), 0); | |
796 | gcc_assert (GET_CODE (cond) == comp); | |
797 | gcc_assert (rtx_equal_p (op0, XEXP (cond, 0))); | |
798 | gcc_assert (rtx_equal_p (op1, XEXP (cond, 1))); | |
799 | emit_jump_insn (copy_insn (PATTERN (cinsn))); | |
f9a00e9e | 800 | jump = as_a <rtx_jump_insn *> (get_last_insn ()); |
b99ab275 | 801 | JUMP_LABEL (jump) = JUMP_LABEL (cinsn); |
802 | LABEL_NUSES (JUMP_LABEL (jump))++; | |
803 | redirect_jump (jump, label, 0); | |
804 | } | |
805 | else | |
806 | { | |
807 | gcc_assert (!cinsn); | |
808 | ||
809 | op0 = force_operand (op0, NULL_RTX); | |
810 | op1 = force_operand (op1, NULL_RTX); | |
811 | do_compare_rtx_and_jump (op0, op1, comp, 0, | |
720cfc43 | 812 | mode, NULL_RTX, NULL, label, |
813 | profile_probability::uninitialized ()); | |
f9a00e9e | 814 | jump = as_a <rtx_jump_insn *> (get_last_insn ()); |
815 | jump->set_jump_target (label); | |
b99ab275 | 816 | LABEL_NUSES (label)++; |
817 | } | |
720cfc43 | 818 | if (prob.initialized_p ()) |
61cb1816 | 819 | add_reg_br_prob_note (jump, prob); |
b99ab275 | 820 | |
821 | seq = get_insns (); | |
822 | end_sequence (); | |
823 | ||
824 | return seq; | |
825 | } | |
826 | ||
1c18ed19 | 827 | /* Unroll LOOP for which we are able to count number of iterations in runtime |
828 | LOOP->LPT_DECISION.TIMES times. The transformation does this (with some | |
ad5201d0 | 829 | extra care for case n < 0): |
3ad4992f | 830 | |
ad5201d0 | 831 | for (i = 0; i < n; i++) |
832 | body; | |
3ad4992f | 833 | |
1c18ed19 | 834 | ==> (LOOP->LPT_DECISION.TIMES == 3) |
3ad4992f | 835 | |
ad5201d0 | 836 | i = 0; |
837 | mod = n % 4; | |
3ad4992f | 838 | |
ad5201d0 | 839 | switch (mod) |
840 | { | |
841 | case 3: | |
842 | body; i++; | |
843 | case 2: | |
844 | body; i++; | |
845 | case 1: | |
846 | body; i++; | |
847 | case 0: ; | |
848 | } | |
3ad4992f | 849 | |
ad5201d0 | 850 | while (i < n) |
851 | { | |
852 | body; i++; | |
853 | body; i++; | |
854 | body; i++; | |
855 | body; i++; | |
856 | } | |
857 | */ | |
858 | static void | |
7194de72 | 859 | unroll_loop_runtime_iterations (struct loop *loop) |
ad5201d0 | 860 | { |
222dc1d3 | 861 | rtx old_niter, niter, tmp; |
862 | rtx_insn *init_code, *branch_code; | |
720cfc43 | 863 | unsigned i, j; |
864 | profile_probability p; | |
bf866763 | 865 | basic_block preheader, *body, swtch, ezc_swtch = NULL; |
305db1a8 | 866 | int may_exit_copy, iter_freq, new_freq; |
db9cef39 | 867 | profile_count iter_count, new_count; |
f3c40e6d | 868 | unsigned n_peel; |
f3c40e6d | 869 | edge e; |
ad5201d0 | 870 | bool extra_zero_check, last_may_exit; |
871 | unsigned max_unroll = loop->lpt_decision.times; | |
f9cce2dc | 872 | struct niter_desc *desc = get_simple_loop_desc (loop); |
873 | bool exit_at_end = loop_exit_at_end_p (loop); | |
375bb675 | 874 | struct opt_info *opt_info = NULL; |
a53ff4c1 | 875 | bool ok; |
48e1416a | 876 | |
375bb675 | 877 | if (flag_split_ivs_in_unroller |
878 | || flag_variable_expansion_in_unroller) | |
879 | opt_info = analyze_insns_in_loop (loop); | |
48e1416a | 880 | |
ad5201d0 | 881 | /* Remember blocks whose dominators will have to be updated. */ |
c2078b80 | 882 | auto_vec<basic_block> dom_bbs; |
ad5201d0 | 883 | |
884 | body = get_loop_body (loop); | |
885 | for (i = 0; i < loop->num_nodes; i++) | |
886 | { | |
f1f41a6c | 887 | vec<basic_block> ldom; |
3f9439d7 | 888 | basic_block bb; |
ad5201d0 | 889 | |
3f9439d7 | 890 | ldom = get_dominated_by (CDI_DOMINATORS, body[i]); |
f1f41a6c | 891 | FOR_EACH_VEC_ELT (ldom, j, bb) |
3f9439d7 | 892 | if (!flow_bb_inside_loop_p (loop, bb)) |
f1f41a6c | 893 | dom_bbs.safe_push (bb); |
ad5201d0 | 894 | |
f1f41a6c | 895 | ldom.release (); |
ad5201d0 | 896 | } |
897 | free (body); | |
898 | ||
f9cce2dc | 899 | if (!exit_at_end) |
ad5201d0 | 900 | { |
901 | /* Leave exit in first copy (for explanation why see comment in | |
902 | unroll_loop_constant_iterations). */ | |
903 | may_exit_copy = 0; | |
904 | n_peel = max_unroll - 1; | |
905 | extra_zero_check = true; | |
906 | last_may_exit = false; | |
907 | } | |
908 | else | |
909 | { | |
910 | /* Leave exit in last copy (for explanation why see comment in | |
911 | unroll_loop_constant_iterations). */ | |
912 | may_exit_copy = max_unroll; | |
913 | n_peel = max_unroll; | |
914 | extra_zero_check = false; | |
915 | last_may_exit = true; | |
916 | } | |
917 | ||
918 | /* Get expression for number of iterations. */ | |
919 | start_sequence (); | |
f9cce2dc | 920 | old_niter = niter = gen_reg_rtx (desc->mode); |
921 | tmp = force_operand (copy_rtx (desc->niter_expr), niter); | |
922 | if (tmp != niter) | |
923 | emit_move_insn (niter, tmp); | |
ad5201d0 | 924 | |
b851b8f0 | 925 | /* For loops that exit at end and whose number of iterations is reliable, |
926 | add one to niter to account for first pass through loop body before | |
927 | reaching exit test. */ | |
928 | if (exit_at_end && !desc->noloop_assumptions) | |
bf866763 | 929 | { |
930 | niter = expand_simple_binop (desc->mode, PLUS, | |
931 | niter, const1_rtx, | |
932 | NULL_RTX, 0, OPTAB_LIB_WIDEN); | |
933 | old_niter = niter; | |
934 | } | |
935 | ||
ad5201d0 | 936 | /* Count modulo by ANDing it with max_unroll; we use the fact that |
937 | the number of unrollings is a power of two, and thus this is correct | |
938 | even if there is overflow in the computation. */ | |
f9cce2dc | 939 | niter = expand_simple_binop (desc->mode, AND, |
0359f9f5 | 940 | niter, gen_int_mode (max_unroll, desc->mode), |
ad5201d0 | 941 | NULL_RTX, 0, OPTAB_LIB_WIDEN); |
942 | ||
943 | init_code = get_insns (); | |
944 | end_sequence (); | |
ffbd194b | 945 | unshare_all_rtl_in_chain (init_code); |
ad5201d0 | 946 | |
947 | /* Precondition the loop. */ | |
88e6f696 | 948 | split_edge_and_insert (loop_preheader_edge (loop), init_code); |
ad5201d0 | 949 | |
c2078b80 | 950 | auto_vec<edge> remove_edges; |
ad5201d0 | 951 | |
3c6549f8 | 952 | auto_sbitmap wont_exit (max_unroll + 2); |
ad5201d0 | 953 | |
b851b8f0 | 954 | if (extra_zero_check || desc->noloop_assumptions) |
bf866763 | 955 | { |
956 | /* Peel the first copy of loop body. Leave the exit test if the number | |
957 | of iterations is not reliable. Also record the place of the extra zero | |
958 | check. */ | |
959 | bitmap_clear (wont_exit); | |
960 | if (!desc->noloop_assumptions) | |
961 | bitmap_set_bit (wont_exit, 1); | |
962 | ezc_swtch = loop_preheader_edge (loop)->src; | |
963 | ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop), | |
964 | 1, wont_exit, desc->out_edge, | |
965 | &remove_edges, | |
966 | DLTHE_FLAG_UPDATE_FREQ); | |
967 | gcc_assert (ok); | |
968 | } | |
ad5201d0 | 969 | |
970 | /* Record the place where switch will be built for preconditioning. */ | |
88e6f696 | 971 | swtch = split_edge (loop_preheader_edge (loop)); |
ad5201d0 | 972 | |
305db1a8 | 973 | /* Compute frequency/count increments for each switch block and initialize |
974 | innermost switch block. Switch blocks and peeled loop copies are built | |
975 | from innermost outward. */ | |
976 | iter_freq = new_freq = swtch->frequency / (max_unroll + 1); | |
db9cef39 | 977 | iter_count = new_count = swtch->count.apply_scale (1, max_unroll + 1); |
305db1a8 | 978 | swtch->frequency = new_freq; |
979 | swtch->count = new_count; | |
305db1a8 | 980 | |
ad5201d0 | 981 | for (i = 0; i < n_peel; i++) |
982 | { | |
983 | /* Peel the copy. */ | |
53c5d9d4 | 984 | bitmap_clear (wont_exit); |
ad5201d0 | 985 | if (i != n_peel - 1 || !last_may_exit) |
08b7917c | 986 | bitmap_set_bit (wont_exit, 1); |
a53ff4c1 | 987 | ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop), |
7194de72 | 988 | 1, wont_exit, desc->out_edge, |
f3c40e6d | 989 | &remove_edges, |
a53ff4c1 | 990 | DLTHE_FLAG_UPDATE_FREQ); |
991 | gcc_assert (ok); | |
ad5201d0 | 992 | |
c87a3eff | 993 | /* Create item for switch. */ |
994 | j = n_peel - i - (extra_zero_check ? 0 : 1); | |
720cfc43 | 995 | p = profile_probability::always ().apply_scale (1, i + 2); |
c87a3eff | 996 | |
88e6f696 | 997 | preheader = split_edge (loop_preheader_edge (loop)); |
305db1a8 | 998 | /* Add in frequency/count of edge from switch block. */ |
999 | preheader->frequency += iter_freq; | |
1000 | preheader->count += iter_count; | |
f9cce2dc | 1001 | branch_code = compare_and_jump_seq (copy_rtx (niter), GEN_INT (j), EQ, |
a53ff4c1 | 1002 | block_label (preheader), p, |
222dc1d3 | 1003 | NULL); |
c87a3eff | 1004 | |
d6a1bbdb | 1005 | /* We rely on the fact that the compare and jump cannot be optimized out, |
1006 | and hence the cfg we create is correct. */ | |
1007 | gcc_assert (branch_code != NULL_RTX); | |
1008 | ||
88e6f696 | 1009 | swtch = split_edge_and_insert (single_pred_edge (swtch), branch_code); |
0051c76a | 1010 | set_immediate_dominator (CDI_DOMINATORS, preheader, swtch); |
720cfc43 | 1011 | single_succ_edge (swtch)->probability = p.invert (); |
305db1a8 | 1012 | new_freq += iter_freq; |
1013 | new_count += iter_count; | |
1014 | swtch->frequency = new_freq; | |
1015 | swtch->count = new_count; | |
c87a3eff | 1016 | e = make_edge (swtch, preheader, |
ea091dfd | 1017 | single_succ_edge (swtch)->flags & EDGE_IRREDUCIBLE_LOOP); |
c87a3eff | 1018 | e->probability = p; |
ad5201d0 | 1019 | } |
1020 | ||
1021 | if (extra_zero_check) | |
1022 | { | |
1023 | /* Add branch for zero iterations. */ | |
720cfc43 | 1024 | p = profile_probability::always ().apply_scale (1, max_unroll + 1); |
ad5201d0 | 1025 | swtch = ezc_swtch; |
88e6f696 | 1026 | preheader = split_edge (loop_preheader_edge (loop)); |
305db1a8 | 1027 | /* Recompute frequency/count adjustments since initial peel copy may |
1028 | have exited and reduced those values that were computed above. */ | |
1029 | iter_freq = swtch->frequency / (max_unroll + 1); | |
db9cef39 | 1030 | iter_count = swtch->count.apply_scale (1, max_unroll + 1); |
305db1a8 | 1031 | /* Add in frequency/count of edge from switch block. */ |
1032 | preheader->frequency += iter_freq; | |
1033 | preheader->count += iter_count; | |
f9cce2dc | 1034 | branch_code = compare_and_jump_seq (copy_rtx (niter), const0_rtx, EQ, |
a53ff4c1 | 1035 | block_label (preheader), p, |
222dc1d3 | 1036 | NULL); |
d6a1bbdb | 1037 | gcc_assert (branch_code != NULL_RTX); |
ad5201d0 | 1038 | |
88e6f696 | 1039 | swtch = split_edge_and_insert (single_succ_edge (swtch), branch_code); |
0051c76a | 1040 | set_immediate_dominator (CDI_DOMINATORS, preheader, swtch); |
720cfc43 | 1041 | single_succ_edge (swtch)->probability = p.invert (); |
a964683a | 1042 | e = make_edge (swtch, preheader, |
ea091dfd | 1043 | single_succ_edge (swtch)->flags & EDGE_IRREDUCIBLE_LOOP); |
ad5201d0 | 1044 | e->probability = p; |
1045 | } | |
1046 | ||
1047 | /* Recount dominators for outer blocks. */ | |
3f9439d7 | 1048 | iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, false); |
ad5201d0 | 1049 | |
1050 | /* And unroll loop. */ | |
1051 | ||
53c5d9d4 | 1052 | bitmap_ones (wont_exit); |
08b7917c | 1053 | bitmap_clear_bit (wont_exit, may_exit_copy); |
375bb675 | 1054 | opt_info_start_duplication (opt_info); |
48e1416a | 1055 | |
a53ff4c1 | 1056 | ok = duplicate_loop_to_header_edge (loop, loop_latch_edge (loop), |
7194de72 | 1057 | max_unroll, |
a53ff4c1 | 1058 | wont_exit, desc->out_edge, |
f3c40e6d | 1059 | &remove_edges, |
75cc36a4 | 1060 | DLTHE_FLAG_UPDATE_FREQ |
1061 | | (opt_info | |
1062 | ? DLTHE_RECORD_COPY_NUMBER | |
1063 | : 0)); | |
a53ff4c1 | 1064 | gcc_assert (ok); |
48e1416a | 1065 | |
375bb675 | 1066 | if (opt_info) |
a9989fb4 | 1067 | { |
375bb675 | 1068 | apply_opt_in_copies (opt_info, max_unroll, true, true); |
1069 | free_opt_info (opt_info); | |
a9989fb4 | 1070 | } |
1071 | ||
f9cce2dc | 1072 | if (exit_at_end) |
1073 | { | |
01020a5f | 1074 | basic_block exit_block = get_bb_copy (desc->in_edge->src); |
a53ff4c1 | 1075 | /* Find a new in and out edge; they are in the last copy we have |
1076 | made. */ | |
48e1416a | 1077 | |
cd665a06 | 1078 | if (EDGE_SUCC (exit_block, 0)->dest == desc->out_edge->dest) |
f9cce2dc | 1079 | { |
cd665a06 | 1080 | desc->out_edge = EDGE_SUCC (exit_block, 0); |
1081 | desc->in_edge = EDGE_SUCC (exit_block, 1); | |
f9cce2dc | 1082 | } |
1083 | else | |
1084 | { | |
cd665a06 | 1085 | desc->out_edge = EDGE_SUCC (exit_block, 1); |
1086 | desc->in_edge = EDGE_SUCC (exit_block, 0); | |
f9cce2dc | 1087 | } |
1088 | } | |
1089 | ||
ad5201d0 | 1090 | /* Remove the edges. */ |
f1f41a6c | 1091 | FOR_EACH_VEC_ELT (remove_edges, i, e) |
f3c40e6d | 1092 | remove_path (e); |
ad5201d0 | 1093 | |
f9cce2dc | 1094 | /* We must be careful when updating the number of iterations due to |
1095 | preconditioning and the fact that the value must be valid at entry | |
1096 | of the loop. After passing through the above code, we see that | |
1097 | the correct new number of iterations is this: */ | |
a9989fb4 | 1098 | gcc_assert (!desc->const_iter); |
f9cce2dc | 1099 | desc->niter_expr = |
a53ff4c1 | 1100 | simplify_gen_binary (UDIV, desc->mode, old_niter, |
5d5ee71f | 1101 | gen_int_mode (max_unroll + 1, desc->mode)); |
a9ef9877 | 1102 | loop->nb_iterations_upper_bound |
796b6678 | 1103 | = wi::udiv_trunc (loop->nb_iterations_upper_bound, max_unroll + 1); |
a9ef9877 | 1104 | if (loop->any_estimate) |
1105 | loop->nb_iterations_estimate | |
796b6678 | 1106 | = wi::udiv_trunc (loop->nb_iterations_estimate, max_unroll + 1); |
8e3ffe30 | 1107 | if (loop->any_likely_upper_bound) |
1108 | loop->nb_iterations_likely_upper_bound | |
1109 | = wi::udiv_trunc (loop->nb_iterations_likely_upper_bound, max_unroll + 1); | |
f9cce2dc | 1110 | if (exit_at_end) |
1111 | { | |
1112 | desc->niter_expr = | |
1113 | simplify_gen_binary (MINUS, desc->mode, desc->niter_expr, const1_rtx); | |
1114 | desc->noloop_assumptions = NULL_RTX; | |
a9ef9877 | 1115 | --loop->nb_iterations_upper_bound; |
1116 | if (loop->any_estimate | |
e913b5cd | 1117 | && loop->nb_iterations_estimate != 0) |
a9ef9877 | 1118 | --loop->nb_iterations_estimate; |
1119 | else | |
1120 | loop->any_estimate = false; | |
8e3ffe30 | 1121 | if (loop->any_likely_upper_bound |
1122 | && loop->nb_iterations_likely_upper_bound != 0) | |
1123 | --loop->nb_iterations_likely_upper_bound; | |
1124 | else | |
1125 | loop->any_likely_upper_bound = false; | |
f9cce2dc | 1126 | } |
1127 | ||
450d042a | 1128 | if (dump_file) |
1129 | fprintf (dump_file, | |
1130 | ";; Unrolled loop %d times, counting # of iterations " | |
1131 | "in runtime, %i insns\n", | |
ad5201d0 | 1132 | max_unroll, num_loop_insns (loop)); |
1133 | } | |
3ad4992f | 1134 | |
ad5201d0 | 1135 | /* Decide whether to unroll LOOP stupidly and how much. */ |
1136 | static void | |
0051c76a | 1137 | decide_unroll_stupid (struct loop *loop, int flags) |
ad5201d0 | 1138 | { |
1139 | unsigned nunroll, nunroll_by_av, i; | |
f9cce2dc | 1140 | struct niter_desc *desc; |
5de9d3ed | 1141 | widest_int iterations; |
ad5201d0 | 1142 | |
1143 | if (!(flags & UAP_UNROLL_ALL)) | |
1144 | { | |
1145 | /* We were not asked to, just return back silently. */ | |
1146 | return; | |
1147 | } | |
1148 | ||
450d042a | 1149 | if (dump_file) |
1150 | fprintf (dump_file, "\n;; Considering unrolling loop stupidly\n"); | |
ad5201d0 | 1151 | |
1152 | /* nunroll = total number of copies of the original loop body in | |
1153 | unrolled loop (i.e. if it is 2, we have to duplicate loop body once. */ | |
1154 | nunroll = PARAM_VALUE (PARAM_MAX_UNROLLED_INSNS) / loop->ninsns; | |
450d042a | 1155 | nunroll_by_av |
1156 | = PARAM_VALUE (PARAM_MAX_AVERAGE_UNROLLED_INSNS) / loop->av_ninsns; | |
ad5201d0 | 1157 | if (nunroll > nunroll_by_av) |
1158 | nunroll = nunroll_by_av; | |
1159 | if (nunroll > (unsigned) PARAM_VALUE (PARAM_MAX_UNROLL_TIMES)) | |
1160 | nunroll = PARAM_VALUE (PARAM_MAX_UNROLL_TIMES); | |
1161 | ||
9ccaa774 | 1162 | if (targetm.loop_unroll_adjust) |
1163 | nunroll = targetm.loop_unroll_adjust (nunroll, loop); | |
1164 | ||
ad5201d0 | 1165 | /* Skip big loops. */ |
1166 | if (nunroll <= 1) | |
1167 | { | |
450d042a | 1168 | if (dump_file) |
1169 | fprintf (dump_file, ";; Not considering loop, is too big\n"); | |
ad5201d0 | 1170 | return; |
1171 | } | |
1172 | ||
1173 | /* Check for simple loops. */ | |
f9cce2dc | 1174 | desc = get_simple_loop_desc (loop); |
ad5201d0 | 1175 | |
1176 | /* Check simpleness. */ | |
f9cce2dc | 1177 | if (desc->simple_p && !desc->assumptions) |
ad5201d0 | 1178 | { |
450d042a | 1179 | if (dump_file) |
1180 | fprintf (dump_file, ";; The loop is simple\n"); | |
ad5201d0 | 1181 | return; |
1182 | } | |
1183 | ||
1184 | /* Do not unroll loops with branches inside -- it increases number | |
d9459f6b | 1185 | of mispredicts. |
1186 | TODO: this heuristic needs tunning; call inside the loop body | |
1187 | is also relatively good reason to not unroll. */ | |
f9cce2dc | 1188 | if (num_loop_branches (loop) > 1) |
ad5201d0 | 1189 | { |
450d042a | 1190 | if (dump_file) |
1191 | fprintf (dump_file, ";; Not unrolling, contains branches\n"); | |
ad5201d0 | 1192 | return; |
1193 | } | |
1194 | ||
204a2e45 | 1195 | /* Check whether the loop rolls. */ |
f86b328b | 1196 | if ((get_estimated_loop_iterations (loop, &iterations) |
53b01069 | 1197 | || get_likely_max_loop_iterations (loop, &iterations)) |
796b6678 | 1198 | && wi::ltu_p (iterations, 2 * nunroll)) |
ad5201d0 | 1199 | { |
450d042a | 1200 | if (dump_file) |
1201 | fprintf (dump_file, ";; Not unrolling loop, doesn't roll\n"); | |
ad5201d0 | 1202 | return; |
1203 | } | |
1204 | ||
1205 | /* Success. Now force nunroll to be power of 2, as it seems that this | |
d01481af | 1206 | improves results (partially because of better alignments, partially |
ad5201d0 | 1207 | because of some dark magic). */ |
f9cce2dc | 1208 | for (i = 1; 2 * i <= nunroll; i *= 2) |
1209 | continue; | |
ad5201d0 | 1210 | |
1211 | loop->lpt_decision.decision = LPT_UNROLL_STUPID; | |
1212 | loop->lpt_decision.times = i - 1; | |
1213 | } | |
1214 | ||
1c18ed19 | 1215 | /* Unroll a LOOP LOOP->LPT_DECISION.TIMES times. The transformation does this: |
1216 | ||
ad5201d0 | 1217 | while (cond) |
1218 | body; | |
1219 | ||
1c18ed19 | 1220 | ==> (LOOP->LPT_DECISION.TIMES == 3) |
ad5201d0 | 1221 | |
1222 | while (cond) | |
1223 | { | |
1224 | body; | |
1225 | if (!cond) break; | |
1226 | body; | |
1227 | if (!cond) break; | |
1228 | body; | |
1229 | if (!cond) break; | |
1230 | body; | |
1231 | } | |
1232 | */ | |
1233 | static void | |
7194de72 | 1234 | unroll_loop_stupid (struct loop *loop) |
ad5201d0 | 1235 | { |
ad5201d0 | 1236 | unsigned nunroll = loop->lpt_decision.times; |
f9cce2dc | 1237 | struct niter_desc *desc = get_simple_loop_desc (loop); |
375bb675 | 1238 | struct opt_info *opt_info = NULL; |
a53ff4c1 | 1239 | bool ok; |
48e1416a | 1240 | |
375bb675 | 1241 | if (flag_split_ivs_in_unroller |
1242 | || flag_variable_expansion_in_unroller) | |
1243 | opt_info = analyze_insns_in_loop (loop); | |
48e1416a | 1244 | |
3c6549f8 | 1245 | auto_sbitmap wont_exit (nunroll + 1); |
53c5d9d4 | 1246 | bitmap_clear (wont_exit); |
375bb675 | 1247 | opt_info_start_duplication (opt_info); |
48e1416a | 1248 | |
a53ff4c1 | 1249 | ok = duplicate_loop_to_header_edge (loop, loop_latch_edge (loop), |
7194de72 | 1250 | nunroll, wont_exit, |
f3c40e6d | 1251 | NULL, NULL, |
75cc36a4 | 1252 | DLTHE_FLAG_UPDATE_FREQ |
1253 | | (opt_info | |
1254 | ? DLTHE_RECORD_COPY_NUMBER | |
1255 | : 0)); | |
a53ff4c1 | 1256 | gcc_assert (ok); |
48e1416a | 1257 | |
375bb675 | 1258 | if (opt_info) |
a9989fb4 | 1259 | { |
375bb675 | 1260 | apply_opt_in_copies (opt_info, nunroll, true, true); |
1261 | free_opt_info (opt_info); | |
a9989fb4 | 1262 | } |
1263 | ||
f9cce2dc | 1264 | if (desc->simple_p) |
1265 | { | |
1266 | /* We indeed may get here provided that there are nontrivial assumptions | |
1267 | for a loop to be really simple. We could update the counts, but the | |
1268 | problem is that we are unable to decide which exit will be taken | |
1269 | (not really true in case the number of iterations is constant, | |
75de4aa2 | 1270 | but no one will do anything with this information, so we do not |
f9cce2dc | 1271 | worry about it). */ |
1272 | desc->simple_p = false; | |
1273 | } | |
1274 | ||
450d042a | 1275 | if (dump_file) |
1276 | fprintf (dump_file, ";; Unrolled loop %d times, %i insns\n", | |
ad5201d0 | 1277 | nunroll, num_loop_insns (loop)); |
1278 | } | |
a9989fb4 | 1279 | |
3b3940d7 | 1280 | /* Returns true if REG is referenced in one nondebug insn in LOOP. |
1281 | Set *DEBUG_USES to the number of debug insns that reference the | |
1282 | variable. */ | |
375bb675 | 1283 | |
f7b51129 | 1284 | static bool |
3b3940d7 | 1285 | referenced_in_one_insn_in_loop_p (struct loop *loop, rtx reg, |
1286 | int *debug_uses) | |
375bb675 | 1287 | { |
1288 | basic_block *body, bb; | |
1289 | unsigned i; | |
1290 | int count_ref = 0; | |
222dc1d3 | 1291 | rtx_insn *insn; |
48e1416a | 1292 | |
1293 | body = get_loop_body (loop); | |
375bb675 | 1294 | for (i = 0; i < loop->num_nodes; i++) |
1295 | { | |
1296 | bb = body[i]; | |
48e1416a | 1297 | |
375bb675 | 1298 | FOR_BB_INSNS (bb, insn) |
3b3940d7 | 1299 | if (!rtx_referenced_p (reg, insn)) |
1300 | continue; | |
1301 | else if (DEBUG_INSN_P (insn)) | |
1302 | ++*debug_uses; | |
1303 | else if (++count_ref > 1) | |
1304 | break; | |
375bb675 | 1305 | } |
3b3940d7 | 1306 | free (body); |
375bb675 | 1307 | return (count_ref == 1); |
1308 | } | |
1309 | ||
3b3940d7 | 1310 | /* Reset the DEBUG_USES debug insns in LOOP that reference REG. */ |
1311 | ||
1312 | static void | |
1313 | reset_debug_uses_in_loop (struct loop *loop, rtx reg, int debug_uses) | |
1314 | { | |
1315 | basic_block *body, bb; | |
1316 | unsigned i; | |
222dc1d3 | 1317 | rtx_insn *insn; |
3b3940d7 | 1318 | |
1319 | body = get_loop_body (loop); | |
1320 | for (i = 0; debug_uses && i < loop->num_nodes; i++) | |
1321 | { | |
1322 | bb = body[i]; | |
1323 | ||
1324 | FOR_BB_INSNS (bb, insn) | |
1325 | if (!DEBUG_INSN_P (insn) || !rtx_referenced_p (reg, insn)) | |
1326 | continue; | |
1327 | else | |
1328 | { | |
1329 | validate_change (insn, &INSN_VAR_LOCATION_LOC (insn), | |
1330 | gen_rtx_UNKNOWN_VAR_LOC (), 0); | |
1331 | if (!--debug_uses) | |
1332 | break; | |
1333 | } | |
1334 | } | |
1335 | free (body); | |
1336 | } | |
1337 | ||
375bb675 | 1338 | /* Determine whether INSN contains an accumulator |
48e1416a | 1339 | which can be expanded into separate copies, |
375bb675 | 1340 | one for each copy of the LOOP body. |
48e1416a | 1341 | |
375bb675 | 1342 | for (i = 0 ; i < n; i++) |
1343 | sum += a[i]; | |
48e1416a | 1344 | |
375bb675 | 1345 | ==> |
48e1416a | 1346 | |
375bb675 | 1347 | sum += a[i] |
1348 | .... | |
1349 | i = i+1; | |
1350 | sum1 += a[i] | |
1351 | .... | |
1352 | i = i+1 | |
1353 | sum2 += a[i]; | |
1354 | .... | |
1355 | ||
48e1416a | 1356 | Return NULL if INSN contains no opportunity for expansion of accumulator. |
1357 | Otherwise, allocate a VAR_TO_EXPAND structure, fill it with the relevant | |
375bb675 | 1358 | information and return a pointer to it. |
1359 | */ | |
1360 | ||
1361 | static struct var_to_expand * | |
222dc1d3 | 1362 | analyze_insn_to_expand_var (struct loop *loop, rtx_insn *insn) |
375bb675 | 1363 | { |
7497b98c | 1364 | rtx set, dest, src; |
375bb675 | 1365 | struct var_to_expand *ves; |
0def560a | 1366 | unsigned accum_pos; |
7497b98c | 1367 | enum rtx_code code; |
3b3940d7 | 1368 | int debug_uses = 0; |
0def560a | 1369 | |
375bb675 | 1370 | set = single_set (insn); |
1371 | if (!set) | |
1372 | return NULL; | |
48e1416a | 1373 | |
375bb675 | 1374 | dest = SET_DEST (set); |
1375 | src = SET_SRC (set); | |
7497b98c | 1376 | code = GET_CODE (src); |
48e1416a | 1377 | |
7497b98c | 1378 | if (code != PLUS && code != MINUS && code != MULT && code != FMA) |
375bb675 | 1379 | return NULL; |
1c6304f6 | 1380 | |
7497b98c | 1381 | if (FLOAT_MODE_P (GET_MODE (dest))) |
1382 | { | |
1383 | if (!flag_associative_math) | |
1384 | return NULL; | |
1385 | /* In the case of FMA, we're also changing the rounding. */ | |
1386 | if (code == FMA && !flag_unsafe_math_optimizations) | |
1387 | return NULL; | |
1388 | } | |
1389 | ||
1c6304f6 | 1390 | /* Hmm, this is a bit paradoxical. We know that INSN is a valid insn |
1391 | in MD. But if there is no optab to generate the insn, we can not | |
1392 | perform the variable expansion. This can happen if an MD provides | |
1393 | an insn but not a named pattern to generate it, for example to avoid | |
1394 | producing code that needs additional mode switches like for x87/mmx. | |
1395 | ||
1396 | So we check have_insn_for which looks for an optab for the operation | |
1397 | in SRC. If it doesn't exist, we can't perform the expansion even | |
1398 | though INSN is valid. */ | |
7497b98c | 1399 | if (!have_insn_for (code, GET_MODE (src))) |
1c6304f6 | 1400 | return NULL; |
1401 | ||
375bb675 | 1402 | if (!REG_P (dest) |
1403 | && !(GET_CODE (dest) == SUBREG | |
1404 | && REG_P (SUBREG_REG (dest)))) | |
1405 | return NULL; | |
48e1416a | 1406 | |
7497b98c | 1407 | /* Find the accumulator use within the operation. */ |
1408 | if (code == FMA) | |
1409 | { | |
1410 | /* We only support accumulation via FMA in the ADD position. */ | |
1411 | if (!rtx_equal_p (dest, XEXP (src, 2))) | |
1412 | return NULL; | |
1413 | accum_pos = 2; | |
1414 | } | |
1415 | else if (rtx_equal_p (dest, XEXP (src, 0))) | |
0def560a | 1416 | accum_pos = 0; |
7497b98c | 1417 | else if (rtx_equal_p (dest, XEXP (src, 1))) |
1418 | { | |
1419 | /* The method of expansion that we are using; which includes the | |
1420 | initialization of the expansions with zero and the summation of | |
1421 | the expansions at the end of the computation will yield wrong | |
1422 | results for (x = something - x) thus avoid using it in that case. */ | |
1423 | if (code == MINUS) | |
1424 | return NULL; | |
1425 | accum_pos = 1; | |
1426 | } | |
0def560a | 1427 | else |
1428 | return NULL; | |
1429 | ||
7497b98c | 1430 | /* It must not otherwise be used. */ |
1431 | if (code == FMA) | |
1432 | { | |
1433 | if (rtx_referenced_p (dest, XEXP (src, 0)) | |
1434 | || rtx_referenced_p (dest, XEXP (src, 1))) | |
1435 | return NULL; | |
1436 | } | |
1437 | else if (rtx_referenced_p (dest, XEXP (src, 1 - accum_pos))) | |
375bb675 | 1438 | return NULL; |
48e1416a | 1439 | |
7497b98c | 1440 | /* It must be used in exactly one insn. */ |
3b3940d7 | 1441 | if (!referenced_in_one_insn_in_loop_p (loop, dest, &debug_uses)) |
375bb675 | 1442 | return NULL; |
48e1416a | 1443 | |
e24a805c | 1444 | if (dump_file) |
7497b98c | 1445 | { |
1446 | fprintf (dump_file, "\n;; Expanding Accumulator "); | |
1447 | print_rtl (dump_file, dest); | |
1448 | fprintf (dump_file, "\n"); | |
1449 | } | |
e24a805c | 1450 | |
3b3940d7 | 1451 | if (debug_uses) |
1452 | /* Instead of resetting the debug insns, we could replace each | |
1453 | debug use in the loop with the sum or product of all expanded | |
2fbe7a32 | 1454 | accumulators. Since we'll only know of all expansions at the |
3b3940d7 | 1455 | end, we'd have to keep track of which vars_to_expand a debug |
1456 | insn in the loop references, take note of each copy of the | |
1457 | debug insn during unrolling, and when it's all done, compute | |
1458 | the sum or product of each variable and adjust the original | |
1459 | debug insn and each copy thereof. What a pain! */ | |
1460 | reset_debug_uses_in_loop (loop, dest, debug_uses); | |
1461 | ||
375bb675 | 1462 | /* Record the accumulator to expand. */ |
4c36ffe6 | 1463 | ves = XNEW (struct var_to_expand); |
375bb675 | 1464 | ves->insn = insn; |
375bb675 | 1465 | ves->reg = copy_rtx (dest); |
f1f41a6c | 1466 | ves->var_expansions.create (1); |
b635a1a3 | 1467 | ves->next = NULL; |
375bb675 | 1468 | ves->op = GET_CODE (src); |
1469 | ves->expansion_count = 0; | |
1470 | ves->reuse_expansion = 0; | |
48e1416a | 1471 | return ves; |
375bb675 | 1472 | } |
1473 | ||
a9989fb4 | 1474 | /* Determine whether there is an induction variable in INSN that |
48e1416a | 1475 | we would like to split during unrolling. |
375bb675 | 1476 | |
1477 | I.e. replace | |
1478 | ||
1479 | i = i + 1; | |
1480 | ... | |
1481 | i = i + 1; | |
1482 | ... | |
1483 | i = i + 1; | |
1484 | ... | |
1485 | ||
1486 | type chains by | |
1487 | ||
1488 | i0 = i + 1 | |
1489 | ... | |
1490 | i = i0 + 1 | |
1491 | ... | |
1492 | i = i0 + 2 | |
1493 | ... | |
1494 | ||
48e1416a | 1495 | Return NULL if INSN contains no interesting IVs. Otherwise, allocate |
375bb675 | 1496 | an IV_TO_SPLIT structure, fill it with the relevant information and return a |
a9989fb4 | 1497 | pointer to it. */ |
1498 | ||
1499 | static struct iv_to_split * | |
3eeb4f9a | 1500 | analyze_iv_to_split_insn (rtx_insn *insn) |
a9989fb4 | 1501 | { |
1502 | rtx set, dest; | |
1503 | struct rtx_iv iv; | |
1504 | struct iv_to_split *ivts; | |
601e68ad | 1505 | scalar_int_mode mode; |
a53ff4c1 | 1506 | bool ok; |
a9989fb4 | 1507 | |
1508 | /* For now we just split the basic induction variables. Later this may be | |
1509 | extended for example by selecting also addresses of memory references. */ | |
1510 | set = single_set (insn); | |
1511 | if (!set) | |
1512 | return NULL; | |
1513 | ||
1514 | dest = SET_DEST (set); | |
601e68ad | 1515 | if (!REG_P (dest) || !is_a <scalar_int_mode> (GET_MODE (dest), &mode)) |
a9989fb4 | 1516 | return NULL; |
1517 | ||
601e68ad | 1518 | if (!biv_p (insn, mode, dest)) |
a9989fb4 | 1519 | return NULL; |
1520 | ||
3f37d465 | 1521 | ok = iv_analyze_result (insn, dest, &iv); |
e8820970 | 1522 | |
1523 | /* This used to be an assert under the assumption that if biv_p returns | |
1524 | true that iv_analyze_result must also return true. However, that | |
1525 | assumption is not strictly correct as evidenced by pr25569. | |
1526 | ||
1527 | Returning NULL when iv_analyze_result returns false is safe and | |
1528 | avoids the problems in pr25569 until the iv_analyze_* routines | |
1529 | can be fixed, which is apparently hard and time consuming | |
1530 | according to their author. */ | |
1531 | if (! ok) | |
1532 | return NULL; | |
a9989fb4 | 1533 | |
1534 | if (iv.step == const0_rtx | |
1535 | || iv.mode != iv.extend_mode) | |
1536 | return NULL; | |
1537 | ||
1538 | /* Record the insn to split. */ | |
4c36ffe6 | 1539 | ivts = XNEW (struct iv_to_split); |
a9989fb4 | 1540 | ivts->insn = insn; |
ef770610 | 1541 | ivts->orig_var = dest; |
a9989fb4 | 1542 | ivts->base_var = NULL_RTX; |
1543 | ivts->step = iv.step; | |
b635a1a3 | 1544 | ivts->next = NULL; |
48e1416a | 1545 | |
a9989fb4 | 1546 | return ivts; |
1547 | } | |
1548 | ||
375bb675 | 1549 | /* Determines which of insns in LOOP can be optimized. |
1550 | Return a OPT_INFO struct with the relevant hash tables filled | |
1551 | with all insns to be optimized. The FIRST_NEW_BLOCK field | |
a9989fb4 | 1552 | is undefined for the return value. */ |
1553 | ||
375bb675 | 1554 | static struct opt_info * |
1555 | analyze_insns_in_loop (struct loop *loop) | |
a9989fb4 | 1556 | { |
1557 | basic_block *body, bb; | |
749ea85f | 1558 | unsigned i; |
4c36ffe6 | 1559 | struct opt_info *opt_info = XCNEW (struct opt_info); |
3eeb4f9a | 1560 | rtx_insn *insn; |
375bb675 | 1561 | struct iv_to_split *ivts = NULL; |
1562 | struct var_to_expand *ves = NULL; | |
d9dd21a8 | 1563 | iv_to_split **slot1; |
1564 | var_to_expand **slot2; | |
f1f41a6c | 1565 | vec<edge> edges = get_loop_exit_edges (loop); |
749ea85f | 1566 | edge exit; |
375bb675 | 1567 | bool can_apply = false; |
48e1416a | 1568 | |
a9989fb4 | 1569 | iv_analysis_loop_init (loop); |
1570 | ||
1571 | body = get_loop_body (loop); | |
375bb675 | 1572 | |
1573 | if (flag_split_ivs_in_unroller) | |
b635a1a3 | 1574 | { |
c1f445d2 | 1575 | opt_info->insns_to_split |
1576 | = new hash_table<iv_split_hasher> (5 * loop->num_nodes); | |
b635a1a3 | 1577 | opt_info->iv_to_split_head = NULL; |
1578 | opt_info->iv_to_split_tail = &opt_info->iv_to_split_head; | |
1579 | } | |
48e1416a | 1580 | |
375bb675 | 1581 | /* Record the loop exit bb and loop preheader before the unrolling. */ |
88e6f696 | 1582 | opt_info->loop_preheader = loop_preheader_edge (loop)->src; |
48e1416a | 1583 | |
f1f41a6c | 1584 | if (edges.length () == 1) |
375bb675 | 1585 | { |
f1f41a6c | 1586 | exit = edges[0]; |
749ea85f | 1587 | if (!(exit->flags & EDGE_COMPLEX)) |
1588 | { | |
1589 | opt_info->loop_exit = split_edge (exit); | |
1590 | can_apply = true; | |
1591 | } | |
375bb675 | 1592 | } |
48e1416a | 1593 | |
375bb675 | 1594 | if (flag_variable_expansion_in_unroller |
1595 | && can_apply) | |
b635a1a3 | 1596 | { |
c1f445d2 | 1597 | opt_info->insns_with_var_to_expand |
1598 | = new hash_table<var_expand_hasher> (5 * loop->num_nodes); | |
b635a1a3 | 1599 | opt_info->var_to_expand_head = NULL; |
1600 | opt_info->var_to_expand_tail = &opt_info->var_to_expand_head; | |
1601 | } | |
48e1416a | 1602 | |
a9989fb4 | 1603 | for (i = 0; i < loop->num_nodes; i++) |
1604 | { | |
1605 | bb = body[i]; | |
1606 | if (!dominated_by_p (CDI_DOMINATORS, loop->latch, bb)) | |
1607 | continue; | |
1608 | ||
1609 | FOR_BB_INSNS (bb, insn) | |
375bb675 | 1610 | { |
1611 | if (!INSN_P (insn)) | |
1612 | continue; | |
48e1416a | 1613 | |
c1f445d2 | 1614 | if (opt_info->insns_to_split) |
375bb675 | 1615 | ivts = analyze_iv_to_split_insn (insn); |
48e1416a | 1616 | |
375bb675 | 1617 | if (ivts) |
1618 | { | |
c1f445d2 | 1619 | slot1 = opt_info->insns_to_split->find_slot (ivts, INSERT); |
b635a1a3 | 1620 | gcc_assert (*slot1 == NULL); |
375bb675 | 1621 | *slot1 = ivts; |
b635a1a3 | 1622 | *opt_info->iv_to_split_tail = ivts; |
1623 | opt_info->iv_to_split_tail = &ivts->next; | |
375bb675 | 1624 | continue; |
1625 | } | |
48e1416a | 1626 | |
c1f445d2 | 1627 | if (opt_info->insns_with_var_to_expand) |
375bb675 | 1628 | ves = analyze_insn_to_expand_var (loop, insn); |
48e1416a | 1629 | |
375bb675 | 1630 | if (ves) |
1631 | { | |
c1f445d2 | 1632 | slot2 = opt_info->insns_with_var_to_expand->find_slot (ves, INSERT); |
b635a1a3 | 1633 | gcc_assert (*slot2 == NULL); |
375bb675 | 1634 | *slot2 = ves; |
b635a1a3 | 1635 | *opt_info->var_to_expand_tail = ves; |
1636 | opt_info->var_to_expand_tail = &ves->next; | |
375bb675 | 1637 | } |
1638 | } | |
a9989fb4 | 1639 | } |
48e1416a | 1640 | |
f1f41a6c | 1641 | edges.release (); |
a9989fb4 | 1642 | free (body); |
375bb675 | 1643 | return opt_info; |
a9989fb4 | 1644 | } |
1645 | ||
1646 | /* Called just before loop duplication. Records start of duplicated area | |
375bb675 | 1647 | to OPT_INFO. */ |
a9989fb4 | 1648 | |
48e1416a | 1649 | static void |
375bb675 | 1650 | opt_info_start_duplication (struct opt_info *opt_info) |
a9989fb4 | 1651 | { |
375bb675 | 1652 | if (opt_info) |
fe672ac0 | 1653 | opt_info->first_new_block = last_basic_block_for_fn (cfun); |
a9989fb4 | 1654 | } |
1655 | ||
1656 | /* Determine the number of iterations between initialization of the base | |
1657 | variable and the current copy (N_COPY). N_COPIES is the total number | |
1658 | of newly created copies. UNROLLING is true if we are unrolling | |
1659 | (not peeling) the loop. */ | |
1660 | ||
1661 | static unsigned | |
1662 | determine_split_iv_delta (unsigned n_copy, unsigned n_copies, bool unrolling) | |
1663 | { | |
1664 | if (unrolling) | |
1665 | { | |
1666 | /* If we are unrolling, initialization is done in the original loop | |
1667 | body (number 0). */ | |
1668 | return n_copy; | |
1669 | } | |
1670 | else | |
1671 | { | |
1672 | /* If we are peeling, the copy in that the initialization occurs has | |
1673 | number 1. The original loop (number 0) is the last. */ | |
1674 | if (n_copy) | |
1675 | return n_copy - 1; | |
1676 | else | |
1677 | return n_copies; | |
1678 | } | |
1679 | } | |
1680 | ||
b635a1a3 | 1681 | /* Allocate basic variable for the induction variable chain. */ |
a9989fb4 | 1682 | |
b635a1a3 | 1683 | static void |
1684 | allocate_basic_variable (struct iv_to_split *ivts) | |
a9989fb4 | 1685 | { |
686fd44c | 1686 | rtx expr = SET_SRC (single_set (ivts->insn)); |
a9989fb4 | 1687 | |
1688 | ivts->base_var = gen_reg_rtx (GET_MODE (expr)); | |
a9989fb4 | 1689 | } |
1690 | ||
1691 | /* Insert initialization of basic variable of IVTS before INSN, taking | |
1692 | the initial value from INSN. */ | |
1693 | ||
1694 | static void | |
222dc1d3 | 1695 | insert_base_initialization (struct iv_to_split *ivts, rtx_insn *insn) |
a9989fb4 | 1696 | { |
686fd44c | 1697 | rtx expr = copy_rtx (SET_SRC (single_set (insn))); |
222dc1d3 | 1698 | rtx_insn *seq; |
a9989fb4 | 1699 | |
1700 | start_sequence (); | |
1701 | expr = force_operand (expr, ivts->base_var); | |
1702 | if (expr != ivts->base_var) | |
1703 | emit_move_insn (ivts->base_var, expr); | |
1704 | seq = get_insns (); | |
1705 | end_sequence (); | |
1706 | ||
1707 | emit_insn_before (seq, insn); | |
1708 | } | |
1709 | ||
1710 | /* Replace the use of induction variable described in IVTS in INSN | |
1711 | by base variable + DELTA * step. */ | |
1712 | ||
1713 | static void | |
222dc1d3 | 1714 | split_iv (struct iv_to_split *ivts, rtx_insn *insn, unsigned delta) |
a9989fb4 | 1715 | { |
222dc1d3 | 1716 | rtx expr, *loc, incr, var; |
1717 | rtx_insn *seq; | |
3754d046 | 1718 | machine_mode mode = GET_MODE (ivts->base_var); |
a9989fb4 | 1719 | rtx src, dest, set; |
1720 | ||
1721 | /* Construct base + DELTA * step. */ | |
1722 | if (!delta) | |
1723 | expr = ivts->base_var; | |
1724 | else | |
1725 | { | |
1726 | incr = simplify_gen_binary (MULT, mode, | |
60ca8f8e | 1727 | copy_rtx (ivts->step), |
1728 | gen_int_mode (delta, mode)); | |
a9989fb4 | 1729 | expr = simplify_gen_binary (PLUS, GET_MODE (ivts->base_var), |
1730 | ivts->base_var, incr); | |
1731 | } | |
1732 | ||
1733 | /* Figure out where to do the replacement. */ | |
686fd44c | 1734 | loc = &SET_SRC (single_set (insn)); |
a9989fb4 | 1735 | |
1736 | /* If we can make the replacement right away, we're done. */ | |
1737 | if (validate_change (insn, loc, expr, 0)) | |
1738 | return; | |
1739 | ||
1740 | /* Otherwise, force EXPR into a register and try again. */ | |
1741 | start_sequence (); | |
1742 | var = gen_reg_rtx (mode); | |
1743 | expr = force_operand (expr, var); | |
1744 | if (expr != var) | |
1745 | emit_move_insn (var, expr); | |
1746 | seq = get_insns (); | |
1747 | end_sequence (); | |
1748 | emit_insn_before (seq, insn); | |
48e1416a | 1749 | |
a9989fb4 | 1750 | if (validate_change (insn, loc, var, 0)) |
1751 | return; | |
1752 | ||
1753 | /* The last chance. Try recreating the assignment in insn | |
1754 | completely from scratch. */ | |
1755 | set = single_set (insn); | |
1756 | gcc_assert (set); | |
1757 | ||
1758 | start_sequence (); | |
1759 | *loc = var; | |
1760 | src = copy_rtx (SET_SRC (set)); | |
1761 | dest = copy_rtx (SET_DEST (set)); | |
1762 | src = force_operand (src, dest); | |
1763 | if (src != dest) | |
1764 | emit_move_insn (dest, src); | |
1765 | seq = get_insns (); | |
1766 | end_sequence (); | |
48e1416a | 1767 | |
a9989fb4 | 1768 | emit_insn_before (seq, insn); |
1769 | delete_insn (insn); | |
1770 | } | |
1771 | ||
a9989fb4 | 1772 | |
6dce5fff | 1773 | /* Return one expansion of the accumulator recorded in struct VE. */ |
a9989fb4 | 1774 | |
375bb675 | 1775 | static rtx |
1776 | get_expansion (struct var_to_expand *ve) | |
1777 | { | |
1778 | rtx reg; | |
48e1416a | 1779 | |
375bb675 | 1780 | if (ve->reuse_expansion == 0) |
1781 | reg = ve->reg; | |
1782 | else | |
f1f41a6c | 1783 | reg = ve->var_expansions[ve->reuse_expansion - 1]; |
48e1416a | 1784 | |
f1f41a6c | 1785 | if (ve->var_expansions.length () == (unsigned) ve->reuse_expansion) |
375bb675 | 1786 | ve->reuse_expansion = 0; |
48e1416a | 1787 | else |
375bb675 | 1788 | ve->reuse_expansion++; |
48e1416a | 1789 | |
375bb675 | 1790 | return reg; |
1791 | } | |
a9989fb4 | 1792 | |
a9989fb4 | 1793 | |
48e1416a | 1794 | /* Given INSN replace the uses of the accumulator recorded in VE |
375bb675 | 1795 | with a new register. */ |
1796 | ||
1797 | static void | |
222dc1d3 | 1798 | expand_var_during_unrolling (struct var_to_expand *ve, rtx_insn *insn) |
375bb675 | 1799 | { |
1800 | rtx new_reg, set; | |
1801 | bool really_new_expansion = false; | |
48e1416a | 1802 | |
375bb675 | 1803 | set = single_set (insn); |
972e95af | 1804 | gcc_assert (set); |
48e1416a | 1805 | |
375bb675 | 1806 | /* Generate a new register only if the expansion limit has not been |
1807 | reached. Else reuse an already existing expansion. */ | |
1808 | if (PARAM_VALUE (PARAM_MAX_VARIABLE_EXPANSIONS) > ve->expansion_count) | |
1809 | { | |
1810 | really_new_expansion = true; | |
1811 | new_reg = gen_reg_rtx (GET_MODE (ve->reg)); | |
1812 | } | |
1813 | else | |
1814 | new_reg = get_expansion (ve); | |
1815 | ||
d022e236 | 1816 | validate_replace_rtx_group (SET_DEST (set), new_reg, insn); |
375bb675 | 1817 | if (apply_change_group ()) |
1818 | if (really_new_expansion) | |
1819 | { | |
f1f41a6c | 1820 | ve->var_expansions.safe_push (new_reg); |
375bb675 | 1821 | ve->expansion_count++; |
1822 | } | |
1823 | } | |
1824 | ||
b635a1a3 | 1825 | /* Initialize the variable expansions in loop preheader. PLACE is the |
1826 | loop-preheader basic block where the initialization of the | |
1827 | expansions should take place. The expansions are initialized with | |
1828 | (-0) when the operation is plus or minus to honor sign zero. This | |
1829 | way we can prevent cases where the sign of the final result is | |
1830 | effected by the sign of the expansion. Here is an example to | |
1831 | demonstrate this: | |
48e1416a | 1832 | |
428c97ad | 1833 | for (i = 0 ; i < n; i++) |
1834 | sum += something; | |
1835 | ||
1836 | ==> | |
1837 | ||
1838 | sum += something | |
1839 | .... | |
1840 | i = i+1; | |
1841 | sum1 += something | |
1842 | .... | |
1843 | i = i+1 | |
1844 | sum2 += something; | |
1845 | .... | |
48e1416a | 1846 | |
428c97ad | 1847 | When SUM is initialized with -zero and SOMETHING is also -zero; the |
1848 | final result of sum should be -zero thus the expansions sum1 and sum2 | |
1849 | should be initialized with -zero as well (otherwise we will get +zero | |
1850 | as the final result). */ | |
375bb675 | 1851 | |
b635a1a3 | 1852 | static void |
1853 | insert_var_expansion_initialization (struct var_to_expand *ve, | |
1854 | basic_block place) | |
375bb675 | 1855 | { |
222dc1d3 | 1856 | rtx_insn *seq; |
1857 | rtx var, zero_init; | |
375bb675 | 1858 | unsigned i; |
3754d046 | 1859 | machine_mode mode = GET_MODE (ve->reg); |
428c97ad | 1860 | bool honor_signed_zero_p = HONOR_SIGNED_ZEROS (mode); |
1861 | ||
f1f41a6c | 1862 | if (ve->var_expansions.length () == 0) |
b635a1a3 | 1863 | return; |
48e1416a | 1864 | |
375bb675 | 1865 | start_sequence (); |
7497b98c | 1866 | switch (ve->op) |
1867 | { | |
1868 | case FMA: | |
1869 | /* Note that we only accumulate FMA via the ADD operand. */ | |
1870 | case PLUS: | |
1871 | case MINUS: | |
f1f41a6c | 1872 | FOR_EACH_VEC_ELT (ve->var_expansions, i, var) |
7497b98c | 1873 | { |
1874 | if (honor_signed_zero_p) | |
1875 | zero_init = simplify_gen_unary (NEG, mode, CONST0_RTX (mode), mode); | |
1876 | else | |
1877 | zero_init = CONST0_RTX (mode); | |
1878 | emit_move_insn (var, zero_init); | |
1879 | } | |
1880 | break; | |
1881 | ||
1882 | case MULT: | |
f1f41a6c | 1883 | FOR_EACH_VEC_ELT (ve->var_expansions, i, var) |
7497b98c | 1884 | { |
1885 | zero_init = CONST1_RTX (GET_MODE (var)); | |
1886 | emit_move_insn (var, zero_init); | |
1887 | } | |
1888 | break; | |
1889 | ||
1890 | default: | |
1891 | gcc_unreachable (); | |
1892 | } | |
48e1416a | 1893 | |
375bb675 | 1894 | seq = get_insns (); |
1895 | end_sequence (); | |
48e1416a | 1896 | |
d022e236 | 1897 | emit_insn_after (seq, BB_END (place)); |
375bb675 | 1898 | } |
1899 | ||
b635a1a3 | 1900 | /* Combine the variable expansions at the loop exit. PLACE is the |
1901 | loop exit basic block where the summation of the expansions should | |
1902 | take place. */ | |
375bb675 | 1903 | |
b635a1a3 | 1904 | static void |
1905 | combine_var_copies_in_loop_exit (struct var_to_expand *ve, basic_block place) | |
375bb675 | 1906 | { |
375bb675 | 1907 | rtx sum = ve->reg; |
222dc1d3 | 1908 | rtx expr, var; |
1909 | rtx_insn *seq, *insn; | |
375bb675 | 1910 | unsigned i; |
1911 | ||
f1f41a6c | 1912 | if (ve->var_expansions.length () == 0) |
b635a1a3 | 1913 | return; |
48e1416a | 1914 | |
cbebc3ae | 1915 | /* ve->reg might be SUBREG or some other non-shareable RTL, and we use |
1916 | it both here and as the destination of the assignment. */ | |
1917 | sum = copy_rtx (sum); | |
375bb675 | 1918 | start_sequence (); |
7497b98c | 1919 | switch (ve->op) |
1920 | { | |
1921 | case FMA: | |
1922 | /* Note that we only accumulate FMA via the ADD operand. */ | |
1923 | case PLUS: | |
1924 | case MINUS: | |
f1f41a6c | 1925 | FOR_EACH_VEC_ELT (ve->var_expansions, i, var) |
7497b98c | 1926 | sum = simplify_gen_binary (PLUS, GET_MODE (ve->reg), var, sum); |
1927 | break; | |
1928 | ||
1929 | case MULT: | |
f1f41a6c | 1930 | FOR_EACH_VEC_ELT (ve->var_expansions, i, var) |
7497b98c | 1931 | sum = simplify_gen_binary (MULT, GET_MODE (ve->reg), var, sum); |
1932 | break; | |
1933 | ||
1934 | default: | |
1935 | gcc_unreachable (); | |
1936 | } | |
48e1416a | 1937 | |
375bb675 | 1938 | expr = force_operand (sum, ve->reg); |
1939 | if (expr != ve->reg) | |
1940 | emit_move_insn (ve->reg, expr); | |
1941 | seq = get_insns (); | |
1942 | end_sequence (); | |
48e1416a | 1943 | |
375bb675 | 1944 | insn = BB_HEAD (place); |
1945 | while (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
1946 | insn = NEXT_INSN (insn); | |
1947 | ||
1948 | emit_insn_after (seq, insn); | |
375bb675 | 1949 | } |
1950 | ||
ef770610 | 1951 | /* Strip away REG_EQUAL notes for IVs we're splitting. |
1952 | ||
1953 | Updating REG_EQUAL notes for IVs we split is tricky: We | |
1954 | cannot tell until after unrolling, DF-rescanning, and liveness | |
1955 | updating, whether an EQ_USE is reached by the split IV while | |
1956 | the IV reg is still live. See PR55006. | |
1957 | ||
1958 | ??? We cannot use remove_reg_equal_equiv_notes_for_regno, | |
1959 | because RTL loop-iv requires us to defer rescanning insns and | |
1960 | any notes attached to them. So resort to old techniques... */ | |
1961 | ||
1962 | static void | |
222dc1d3 | 1963 | maybe_strip_eq_note_for_split_iv (struct opt_info *opt_info, rtx_insn *insn) |
ef770610 | 1964 | { |
1965 | struct iv_to_split *ivts; | |
1966 | rtx note = find_reg_equal_equiv_note (insn); | |
1967 | if (! note) | |
1968 | return; | |
1969 | for (ivts = opt_info->iv_to_split_head; ivts; ivts = ivts->next) | |
1970 | if (reg_mentioned_p (ivts->orig_var, note)) | |
1971 | { | |
1972 | remove_note (insn, note); | |
1973 | return; | |
1974 | } | |
1975 | } | |
1976 | ||
48e1416a | 1977 | /* Apply loop optimizations in loop copies using the |
1978 | data which gathered during the unrolling. Structure | |
375bb675 | 1979 | OPT_INFO record that data. |
48e1416a | 1980 | |
a9989fb4 | 1981 | UNROLLING is true if we unrolled (not peeled) the loop. |
1982 | REWRITE_ORIGINAL_BODY is true if we should also rewrite the original body of | |
1983 | the loop (as it should happen in complete unrolling, but not in ordinary | |
1984 | peeling of the loop). */ | |
1985 | ||
1986 | static void | |
48e1416a | 1987 | apply_opt_in_copies (struct opt_info *opt_info, |
1988 | unsigned n_copies, bool unrolling, | |
375bb675 | 1989 | bool rewrite_original_loop) |
a9989fb4 | 1990 | { |
1991 | unsigned i, delta; | |
1992 | basic_block bb, orig_bb; | |
222dc1d3 | 1993 | rtx_insn *insn, *orig_insn, *next; |
a9989fb4 | 1994 | struct iv_to_split ivts_templ, *ivts; |
375bb675 | 1995 | struct var_to_expand ve_templ, *ves; |
48e1416a | 1996 | |
a9989fb4 | 1997 | /* Sanity check -- we need to put initialization in the original loop |
1998 | body. */ | |
1999 | gcc_assert (!unrolling || rewrite_original_loop); | |
48e1416a | 2000 | |
a9989fb4 | 2001 | /* Allocate the basic variables (i0). */ |
c1f445d2 | 2002 | if (opt_info->insns_to_split) |
b635a1a3 | 2003 | for (ivts = opt_info->iv_to_split_head; ivts; ivts = ivts->next) |
2004 | allocate_basic_variable (ivts); | |
48e1416a | 2005 | |
fe672ac0 | 2006 | for (i = opt_info->first_new_block; |
2007 | i < (unsigned) last_basic_block_for_fn (cfun); | |
2008 | i++) | |
a9989fb4 | 2009 | { |
f5a6b05f | 2010 | bb = BASIC_BLOCK_FOR_FN (cfun, i); |
01020a5f | 2011 | orig_bb = get_bb_original (bb); |
48e1416a | 2012 | |
01020a5f | 2013 | /* bb->aux holds position in copy sequence initialized by |
2014 | duplicate_loop_to_header_edge. */ | |
2015 | delta = determine_split_iv_delta ((size_t)bb->aux, n_copies, | |
a9989fb4 | 2016 | unrolling); |
75cc36a4 | 2017 | bb->aux = 0; |
a9989fb4 | 2018 | orig_insn = BB_HEAD (orig_bb); |
ef770610 | 2019 | FOR_BB_INSNS_SAFE (bb, insn, next) |
375bb675 | 2020 | { |
0e6893c5 | 2021 | if (!INSN_P (insn) |
2022 | || (DEBUG_INSN_P (insn) | |
2023 | && TREE_CODE (INSN_VAR_LOCATION_DECL (insn)) == LABEL_DECL)) | |
375bb675 | 2024 | continue; |
48e1416a | 2025 | |
0e6893c5 | 2026 | while (!INSN_P (orig_insn) |
2027 | || (DEBUG_INSN_P (orig_insn) | |
2028 | && (TREE_CODE (INSN_VAR_LOCATION_DECL (orig_insn)) | |
2029 | == LABEL_DECL))) | |
375bb675 | 2030 | orig_insn = NEXT_INSN (orig_insn); |
48e1416a | 2031 | |
375bb675 | 2032 | ivts_templ.insn = orig_insn; |
2033 | ve_templ.insn = orig_insn; | |
48e1416a | 2034 | |
375bb675 | 2035 | /* Apply splitting iv optimization. */ |
c1f445d2 | 2036 | if (opt_info->insns_to_split) |
375bb675 | 2037 | { |
ef770610 | 2038 | maybe_strip_eq_note_for_split_iv (opt_info, insn); |
2039 | ||
c1f445d2 | 2040 | ivts = opt_info->insns_to_split->find (&ivts_templ); |
48e1416a | 2041 | |
375bb675 | 2042 | if (ivts) |
2043 | { | |
19ef3705 | 2044 | gcc_assert (GET_CODE (PATTERN (insn)) |
2045 | == GET_CODE (PATTERN (orig_insn))); | |
48e1416a | 2046 | |
375bb675 | 2047 | if (!delta) |
2048 | insert_base_initialization (ivts, insn); | |
2049 | split_iv (ivts, insn, delta); | |
2050 | } | |
2051 | } | |
2052 | /* Apply variable expansion optimization. */ | |
c1f445d2 | 2053 | if (unrolling && opt_info->insns_with_var_to_expand) |
375bb675 | 2054 | { |
4077bf7a | 2055 | ves = (struct var_to_expand *) |
c1f445d2 | 2056 | opt_info->insns_with_var_to_expand->find (&ve_templ); |
375bb675 | 2057 | if (ves) |
48e1416a | 2058 | { |
19ef3705 | 2059 | gcc_assert (GET_CODE (PATTERN (insn)) |
2060 | == GET_CODE (PATTERN (orig_insn))); | |
375bb675 | 2061 | expand_var_during_unrolling (ves, insn); |
2062 | } | |
2063 | } | |
2064 | orig_insn = NEXT_INSN (orig_insn); | |
2065 | } | |
a9989fb4 | 2066 | } |
2067 | ||
2068 | if (!rewrite_original_loop) | |
2069 | return; | |
48e1416a | 2070 | |
375bb675 | 2071 | /* Initialize the variable expansions in the loop preheader |
48e1416a | 2072 | and take care of combining them at the loop exit. */ |
c1f445d2 | 2073 | if (opt_info->insns_with_var_to_expand) |
375bb675 | 2074 | { |
b635a1a3 | 2075 | for (ves = opt_info->var_to_expand_head; ves; ves = ves->next) |
2076 | insert_var_expansion_initialization (ves, opt_info->loop_preheader); | |
2077 | for (ves = opt_info->var_to_expand_head; ves; ves = ves->next) | |
2078 | combine_var_copies_in_loop_exit (ves, opt_info->loop_exit); | |
375bb675 | 2079 | } |
48e1416a | 2080 | |
a9989fb4 | 2081 | /* Rewrite also the original loop body. Find them as originals of the blocks |
2082 | in the last copied iteration, i.e. those that have | |
01020a5f | 2083 | get_bb_copy (get_bb_original (bb)) == bb. */ |
fe672ac0 | 2084 | for (i = opt_info->first_new_block; |
2085 | i < (unsigned) last_basic_block_for_fn (cfun); | |
2086 | i++) | |
a9989fb4 | 2087 | { |
f5a6b05f | 2088 | bb = BASIC_BLOCK_FOR_FN (cfun, i); |
01020a5f | 2089 | orig_bb = get_bb_original (bb); |
2090 | if (get_bb_copy (orig_bb) != bb) | |
a9989fb4 | 2091 | continue; |
48e1416a | 2092 | |
a9989fb4 | 2093 | delta = determine_split_iv_delta (0, n_copies, unrolling); |
2094 | for (orig_insn = BB_HEAD (orig_bb); | |
375bb675 | 2095 | orig_insn != NEXT_INSN (BB_END (bb)); |
2096 | orig_insn = next) | |
2097 | { | |
2098 | next = NEXT_INSN (orig_insn); | |
48e1416a | 2099 | |
375bb675 | 2100 | if (!INSN_P (orig_insn)) |
2101 | continue; | |
48e1416a | 2102 | |
375bb675 | 2103 | ivts_templ.insn = orig_insn; |
c1f445d2 | 2104 | if (opt_info->insns_to_split) |
375bb675 | 2105 | { |
ef770610 | 2106 | maybe_strip_eq_note_for_split_iv (opt_info, orig_insn); |
2107 | ||
4077bf7a | 2108 | ivts = (struct iv_to_split *) |
c1f445d2 | 2109 | opt_info->insns_to_split->find (&ivts_templ); |
375bb675 | 2110 | if (ivts) |
2111 | { | |
2112 | if (!delta) | |
2113 | insert_base_initialization (ivts, orig_insn); | |
2114 | split_iv (ivts, orig_insn, delta); | |
2115 | continue; | |
2116 | } | |
2117 | } | |
48e1416a | 2118 | |
375bb675 | 2119 | } |
2120 | } | |
2121 | } | |
a9989fb4 | 2122 | |
375bb675 | 2123 | /* Release OPT_INFO. */ |
a9989fb4 | 2124 | |
2125 | static void | |
375bb675 | 2126 | free_opt_info (struct opt_info *opt_info) |
a9989fb4 | 2127 | { |
c1f445d2 | 2128 | delete opt_info->insns_to_split; |
2129 | opt_info->insns_to_split = NULL; | |
2130 | if (opt_info->insns_with_var_to_expand) | |
375bb675 | 2131 | { |
b635a1a3 | 2132 | struct var_to_expand *ves; |
2133 | ||
2134 | for (ves = opt_info->var_to_expand_head; ves; ves = ves->next) | |
f1f41a6c | 2135 | ves->var_expansions.release (); |
c1f445d2 | 2136 | delete opt_info->insns_with_var_to_expand; |
2137 | opt_info->insns_with_var_to_expand = NULL; | |
375bb675 | 2138 | } |
2139 | free (opt_info); | |
a9989fb4 | 2140 | } |