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f8934be7 | 1 | /* Loop unrolling. |
5624e564 | 2 | Copyright (C) 2002-2015 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" | |
23 | #include "tm.h" | |
24 | #include "rtl.h" | |
40e23961 MC |
25 | #include "alias.h" |
26 | #include "symtab.h" | |
4d648807 | 27 | #include "tree.h" |
a29c7ea6 | 28 | #include "hard-reg-set.h" |
7932a3db | 29 | #include "obstack.h" |
59f2e9d8 | 30 | #include "profile.h" |
60393bbc | 31 | #include "predict.h" |
60393bbc AM |
32 | #include "function.h" |
33 | #include "dominance.h" | |
34 | #include "cfg.h" | |
35 | #include "cfgrtl.h" | |
a29c7ea6 ZD |
36 | #include "basic-block.h" |
37 | #include "cfgloop.h" | |
a29c7ea6 | 38 | #include "params.h" |
b0710fe1 AM |
39 | #include "insn-codes.h" |
40 | #include "optabs.h" | |
36566b39 | 41 | #include "flags.h" |
36566b39 PK |
42 | #include "insn-config.h" |
43 | #include "expmed.h" | |
44 | #include "dojump.h" | |
45 | #include "explow.h" | |
46 | #include "calls.h" | |
47 | #include "emit-rtl.h" | |
48 | #include "varasm.h" | |
49 | #include "stmt.h" | |
a29c7ea6 | 50 | #include "expr.h" |
b8698a0f | 51 | #include "recog.h" |
40ac4f73 | 52 | #include "target.h" |
7ee2468b | 53 | #include "dumpfile.h" |
a29c7ea6 | 54 | |
f8934be7 JH |
55 | /* This pass performs loop unrolling. We only perform this |
56 | optimization on innermost loops (with single exception) because | |
a29c7ea6 ZD |
57 | the impact on performance is greatest here, and we want to avoid |
58 | unnecessary code size growth. The gain is caused by greater sequentiality | |
4d6922ee | 59 | of code, better code to optimize for further passes and in some cases |
a29c7ea6 ZD |
60 | by fewer testings of exit conditions. The main problem is code growth, |
61 | that impacts performance negatively due to effect of caches. | |
62 | ||
63 | What we do: | |
64 | ||
a29c7ea6 ZD |
65 | -- unrolling of loops that roll constant times; this is almost always |
66 | win, as we get rid of exit condition tests. | |
67 | -- unrolling of loops that roll number of times that we can compute | |
68 | in runtime; we also get rid of exit condition tests here, but there | |
69 | is the extra expense for calculating the number of iterations | |
70 | -- simple unrolling of remaining loops; this is performed only if we | |
71 | are asked to, as the gain is questionable in this case and often | |
72 | it may even slow down the code | |
73 | For more detailed descriptions of each of those, see comments at | |
74 | appropriate function below. | |
75 | ||
76 | There is a lot of parameters (defined and described in params.def) that | |
f8934be7 | 77 | control how much we unroll. |
a29c7ea6 ZD |
78 | |
79 | ??? A great problem is that we don't have a good way how to determine | |
80 | how many times we should unroll the loop; the experiments I have made | |
81 | showed that this choice may affect performance in order of several %. | |
82 | */ | |
83 | ||
113d659a ZD |
84 | /* Information about induction variables to split. */ |
85 | ||
86 | struct iv_to_split | |
87 | { | |
95ecfb26 | 88 | rtx_insn *insn; /* The insn in that the induction variable occurs. */ |
4a0c3fde | 89 | rtx orig_var; /* The variable (register) for the IV before split. */ |
113d659a ZD |
90 | rtx base_var; /* The variable on that the values in the further |
91 | iterations are based. */ | |
92 | rtx step; /* Step of the induction variable. */ | |
a9f6ecee | 93 | struct iv_to_split *next; /* Next entry in walking order. */ |
113d659a ZD |
94 | }; |
95 | ||
f37a4f14 RE |
96 | /* Information about accumulators to expand. */ |
97 | ||
98 | struct var_to_expand | |
99 | { | |
95ecfb26 | 100 | rtx_insn *insn; /* The insn in that the variable expansion occurs. */ |
471854f8 | 101 | rtx reg; /* The accumulator which is expanded. */ |
9771b263 | 102 | vec<rtx> var_expansions; /* The copies of the accumulator which is expanded. */ |
a9f6ecee | 103 | struct var_to_expand *next; /* Next entry in walking order. */ |
b8698a0f | 104 | enum rtx_code op; /* The type of the accumulation - addition, subtraction |
f37a4f14 RE |
105 | or multiplication. */ |
106 | int expansion_count; /* Count the number of expansions generated so far. */ | |
107 | int reuse_expansion; /* The expansion we intend to reuse to expand | |
b8698a0f L |
108 | the accumulator. If REUSE_EXPANSION is 0 reuse |
109 | the original accumulator. Else use | |
f37a4f14 RE |
110 | var_expansions[REUSE_EXPANSION - 1]. */ |
111 | }; | |
112 | ||
4a8fb1a1 LC |
113 | /* Hashtable helper for iv_to_split. */ |
114 | ||
95fbe13e | 115 | struct iv_split_hasher : free_ptr_hash <iv_to_split> |
4a8fb1a1 | 116 | { |
67f58944 TS |
117 | static inline hashval_t hash (const iv_to_split *); |
118 | static inline bool equal (const iv_to_split *, const iv_to_split *); | |
4a8fb1a1 LC |
119 | }; |
120 | ||
121 | ||
122 | /* A hash function for information about insns to split. */ | |
123 | ||
124 | inline hashval_t | |
67f58944 | 125 | iv_split_hasher::hash (const iv_to_split *ivts) |
4a8fb1a1 LC |
126 | { |
127 | return (hashval_t) INSN_UID (ivts->insn); | |
128 | } | |
129 | ||
130 | /* An equality functions for information about insns to split. */ | |
131 | ||
132 | inline bool | |
67f58944 | 133 | iv_split_hasher::equal (const iv_to_split *i1, const iv_to_split *i2) |
4a8fb1a1 LC |
134 | { |
135 | return i1->insn == i2->insn; | |
136 | } | |
137 | ||
138 | /* Hashtable helper for iv_to_split. */ | |
139 | ||
95fbe13e | 140 | struct var_expand_hasher : free_ptr_hash <var_to_expand> |
4a8fb1a1 | 141 | { |
67f58944 TS |
142 | static inline hashval_t hash (const var_to_expand *); |
143 | static inline bool equal (const var_to_expand *, const var_to_expand *); | |
4a8fb1a1 LC |
144 | }; |
145 | ||
146 | /* Return a hash for VES. */ | |
147 | ||
148 | inline hashval_t | |
67f58944 | 149 | var_expand_hasher::hash (const var_to_expand *ves) |
4a8fb1a1 LC |
150 | { |
151 | return (hashval_t) INSN_UID (ves->insn); | |
152 | } | |
153 | ||
154 | /* Return true if I1 and I2 refer to the same instruction. */ | |
155 | ||
156 | inline bool | |
67f58944 | 157 | var_expand_hasher::equal (const var_to_expand *i1, const var_to_expand *i2) |
4a8fb1a1 LC |
158 | { |
159 | return i1->insn == i2->insn; | |
160 | } | |
161 | ||
f37a4f14 RE |
162 | /* Information about optimization applied in |
163 | the unrolled loop. */ | |
164 | ||
165 | struct opt_info | |
113d659a | 166 | { |
c203e8a7 | 167 | hash_table<iv_split_hasher> *insns_to_split; /* A hashtable of insns to |
4a8fb1a1 | 168 | split. */ |
a9f6ecee AO |
169 | struct iv_to_split *iv_to_split_head; /* The first iv to split. */ |
170 | struct iv_to_split **iv_to_split_tail; /* Pointer to the tail of the list. */ | |
c203e8a7 | 171 | hash_table<var_expand_hasher> *insns_with_var_to_expand; /* A hashtable of |
4a8fb1a1 | 172 | insns with accumulators to expand. */ |
a9f6ecee AO |
173 | struct var_to_expand *var_to_expand_head; /* The first var to expand. */ |
174 | struct var_to_expand **var_to_expand_tail; /* Pointer to the tail of the list. */ | |
f37a4f14 RE |
175 | unsigned first_new_block; /* The first basic block that was |
176 | duplicated. */ | |
177 | basic_block loop_exit; /* The loop exit basic block. */ | |
178 | basic_block loop_preheader; /* The loop preheader basic block. */ | |
113d659a ZD |
179 | }; |
180 | ||
d47cc544 SB |
181 | static void decide_unroll_stupid (struct loop *, int); |
182 | static void decide_unroll_constant_iterations (struct loop *, int); | |
183 | static void decide_unroll_runtime_iterations (struct loop *, int); | |
d73be268 | 184 | static void unroll_loop_stupid (struct loop *); |
f8934be7 | 185 | static void decide_unrolling (int); |
d73be268 ZD |
186 | static void unroll_loop_constant_iterations (struct loop *); |
187 | static void unroll_loop_runtime_iterations (struct loop *); | |
f37a4f14 RE |
188 | static struct opt_info *analyze_insns_in_loop (struct loop *); |
189 | static void opt_info_start_duplication (struct opt_info *); | |
190 | static void apply_opt_in_copies (struct opt_info *, unsigned, bool, bool); | |
191 | static void free_opt_info (struct opt_info *); | |
95ecfb26 | 192 | static struct var_to_expand *analyze_insn_to_expand_var (struct loop*, rtx_insn *); |
60c48e4c | 193 | static bool referenced_in_one_insn_in_loop_p (struct loop *, rtx, int *); |
1b20d55a | 194 | static struct iv_to_split *analyze_iv_to_split_insn (rtx_insn *); |
95ecfb26 | 195 | static void expand_var_during_unrolling (struct var_to_expand *, rtx_insn *); |
a9f6ecee AO |
196 | static void insert_var_expansion_initialization (struct var_to_expand *, |
197 | basic_block); | |
198 | static void combine_var_copies_in_loop_exit (struct var_to_expand *, | |
199 | basic_block); | |
f37a4f14 | 200 | static rtx get_expansion (struct var_to_expand *); |
a29c7ea6 | 201 | |
f8934be7 | 202 | /* Emit a message summarizing the unroll that will be |
e25a6711 TJ |
203 | performed for LOOP, along with the loop's location LOCUS, if |
204 | appropriate given the dump or -fopt-info settings. */ | |
205 | ||
206 | static void | |
f8934be7 | 207 | report_unroll (struct loop *loop, location_t locus) |
e25a6711 | 208 | { |
e25a6711 TJ |
209 | int report_flags = MSG_OPTIMIZED_LOCATIONS | TDF_RTL | TDF_DETAILS; |
210 | ||
ad4db775 TJ |
211 | if (loop->lpt_decision.decision == LPT_NONE) |
212 | return; | |
213 | ||
e25a6711 TJ |
214 | if (!dump_enabled_p ()) |
215 | return; | |
216 | ||
f8934be7 JH |
217 | dump_printf_loc (report_flags, locus, |
218 | "loop unrolled %d times", | |
219 | loop->lpt_decision.times); | |
e25a6711 TJ |
220 | if (profile_info) |
221 | dump_printf (report_flags, | |
f8934be7 | 222 | " (header execution count %d)", |
e25a6711 | 223 | (int)loop->header->count); |
e25a6711 TJ |
224 | |
225 | dump_printf (report_flags, "\n"); | |
226 | } | |
227 | ||
f8934be7 | 228 | /* Decide whether unroll loops and how much. */ |
a29c7ea6 | 229 | static void |
f8934be7 | 230 | decide_unrolling (int flags) |
a29c7ea6 | 231 | { |
42fd6772 | 232 | struct loop *loop; |
a29c7ea6 ZD |
233 | |
234 | /* Scan the loops, inner ones first. */ | |
f0bd40b1 | 235 | FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) |
a29c7ea6 | 236 | { |
a29c7ea6 | 237 | loop->lpt_decision.decision = LPT_NONE; |
e25a6711 | 238 | location_t locus = get_loop_location (loop); |
a29c7ea6 | 239 | |
e25a6711 TJ |
240 | if (dump_enabled_p ()) |
241 | dump_printf_loc (TDF_RTL, locus, | |
242 | ";; *** Considering loop %d at BB %d for " | |
f8934be7 | 243 | "unrolling ***\n", |
e25a6711 | 244 | loop->num, loop->header->index); |
a29c7ea6 ZD |
245 | |
246 | /* Do not peel cold areas. */ | |
efd8f750 | 247 | if (optimize_loop_for_size_p (loop)) |
a29c7ea6 | 248 | { |
c263766c RH |
249 | if (dump_file) |
250 | fprintf (dump_file, ";; Not considering loop, cold area\n"); | |
a29c7ea6 ZD |
251 | continue; |
252 | } | |
253 | ||
254 | /* Can the loop be manipulated? */ | |
255 | if (!can_duplicate_loop_p (loop)) | |
256 | { | |
c263766c RH |
257 | if (dump_file) |
258 | fprintf (dump_file, | |
a29c7ea6 | 259 | ";; Not considering loop, cannot duplicate\n"); |
a29c7ea6 ZD |
260 | continue; |
261 | } | |
262 | ||
263 | /* Skip non-innermost loops. */ | |
264 | if (loop->inner) | |
265 | { | |
c263766c RH |
266 | if (dump_file) |
267 | fprintf (dump_file, ";; Not considering loop, is not innermost\n"); | |
a29c7ea6 ZD |
268 | continue; |
269 | } | |
270 | ||
271 | loop->ninsns = num_loop_insns (loop); | |
272 | loop->av_ninsns = average_num_loop_insns (loop); | |
273 | ||
274 | /* Try transformations one by one in decreasing order of | |
275 | priority. */ | |
276 | ||
d47cc544 | 277 | decide_unroll_constant_iterations (loop, flags); |
a29c7ea6 | 278 | if (loop->lpt_decision.decision == LPT_NONE) |
d47cc544 | 279 | decide_unroll_runtime_iterations (loop, flags); |
a29c7ea6 | 280 | if (loop->lpt_decision.decision == LPT_NONE) |
d47cc544 | 281 | decide_unroll_stupid (loop, flags); |
a29c7ea6 | 282 | |
f8934be7 | 283 | report_unroll (loop, locus); |
a29c7ea6 | 284 | } |
a29c7ea6 ZD |
285 | } |
286 | ||
f8934be7 JH |
287 | /* Unroll LOOPS. */ |
288 | void | |
289 | unroll_loops (int flags) | |
a29c7ea6 | 290 | { |
f8934be7 JH |
291 | struct loop *loop; |
292 | bool changed = false; | |
a29c7ea6 | 293 | |
f8934be7 JH |
294 | /* Now decide rest of unrolling. */ |
295 | decide_unrolling (flags); | |
a29c7ea6 | 296 | |
f8934be7 JH |
297 | /* Scan the loops, inner ones first. */ |
298 | FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) | |
a29c7ea6 | 299 | { |
f8934be7 JH |
300 | /* And perform the appropriate transformations. */ |
301 | switch (loop->lpt_decision.decision) | |
0c20a65f | 302 | { |
f8934be7 JH |
303 | case LPT_UNROLL_CONSTANT: |
304 | unroll_loop_constant_iterations (loop); | |
305 | changed = true; | |
306 | break; | |
307 | case LPT_UNROLL_RUNTIME: | |
308 | unroll_loop_runtime_iterations (loop); | |
309 | changed = true; | |
310 | break; | |
311 | case LPT_UNROLL_STUPID: | |
312 | unroll_loop_stupid (loop); | |
313 | changed = true; | |
314 | break; | |
315 | case LPT_NONE: | |
316 | break; | |
317 | default: | |
318 | gcc_unreachable (); | |
a29c7ea6 | 319 | } |
a29c7ea6 ZD |
320 | } |
321 | ||
f8934be7 JH |
322 | if (changed) |
323 | { | |
324 | calculate_dominance_info (CDI_DOMINATORS); | |
325 | fix_loop_structure (NULL); | |
326 | } | |
0c20a65f | 327 | |
f8934be7 JH |
328 | iv_analysis_done (); |
329 | } | |
a29c7ea6 | 330 | |
f8934be7 | 331 | /* Check whether exit of the LOOP is at the end of loop body. */ |
0c20a65f | 332 | |
f8934be7 JH |
333 | static bool |
334 | loop_exit_at_end_p (struct loop *loop) | |
a29c7ea6 | 335 | { |
50654f6c | 336 | struct niter_desc *desc = get_simple_loop_desc (loop); |
f8934be7 | 337 | rtx_insn *insn; |
35b07080 | 338 | |
f8934be7 JH |
339 | /* We should never have conditional in latch block. */ |
340 | gcc_assert (desc->in_edge->dest != loop->header); | |
b8698a0f | 341 | |
f8934be7 JH |
342 | if (desc->in_edge->dest != loop->latch) |
343 | return false; | |
113d659a | 344 | |
f8934be7 JH |
345 | /* Check that the latch is empty. */ |
346 | FOR_BB_INSNS (loop->latch, insn) | |
347 | { | |
348 | if (INSN_P (insn) && active_insn_p (insn)) | |
349 | return false; | |
35b07080 | 350 | } |
a29c7ea6 | 351 | |
f8934be7 | 352 | return true; |
a29c7ea6 ZD |
353 | } |
354 | ||
c263766c RH |
355 | /* Decide whether to unroll LOOP iterating constant number of times |
356 | and how much. */ | |
50654f6c | 357 | |
a29c7ea6 | 358 | static void |
d47cc544 | 359 | decide_unroll_constant_iterations (struct loop *loop, int flags) |
a29c7ea6 | 360 | { |
50654f6c ZD |
361 | unsigned nunroll, nunroll_by_av, best_copies, best_unroll = 0, n_copies, i; |
362 | struct niter_desc *desc; | |
807e902e | 363 | widest_int iterations; |
a29c7ea6 ZD |
364 | |
365 | if (!(flags & UAP_UNROLL)) | |
366 | { | |
367 | /* We were not asked to, just return back silently. */ | |
368 | return; | |
369 | } | |
370 | ||
c263766c RH |
371 | if (dump_file) |
372 | fprintf (dump_file, | |
373 | "\n;; Considering unrolling loop with constant " | |
374 | "number of iterations\n"); | |
a29c7ea6 ZD |
375 | |
376 | /* nunroll = total number of copies of the original loop body in | |
377 | unrolled loop (i.e. if it is 2, we have to duplicate loop body once. */ | |
378 | nunroll = PARAM_VALUE (PARAM_MAX_UNROLLED_INSNS) / loop->ninsns; | |
c263766c RH |
379 | nunroll_by_av |
380 | = PARAM_VALUE (PARAM_MAX_AVERAGE_UNROLLED_INSNS) / loop->av_ninsns; | |
a29c7ea6 ZD |
381 | if (nunroll > nunroll_by_av) |
382 | nunroll = nunroll_by_av; | |
383 | if (nunroll > (unsigned) PARAM_VALUE (PARAM_MAX_UNROLL_TIMES)) | |
384 | nunroll = PARAM_VALUE (PARAM_MAX_UNROLL_TIMES); | |
385 | ||
df0f3392 GG |
386 | if (targetm.loop_unroll_adjust) |
387 | nunroll = targetm.loop_unroll_adjust (nunroll, loop); | |
388 | ||
a29c7ea6 ZD |
389 | /* Skip big loops. */ |
390 | if (nunroll <= 1) | |
391 | { | |
c263766c RH |
392 | if (dump_file) |
393 | fprintf (dump_file, ";; Not considering loop, is too big\n"); | |
a29c7ea6 ZD |
394 | return; |
395 | } | |
396 | ||
397 | /* Check for simple loops. */ | |
50654f6c | 398 | desc = get_simple_loop_desc (loop); |
a29c7ea6 ZD |
399 | |
400 | /* Check number of iterations. */ | |
50654f6c | 401 | if (!desc->simple_p || !desc->const_iter || desc->assumptions) |
a29c7ea6 | 402 | { |
c263766c RH |
403 | if (dump_file) |
404 | fprintf (dump_file, | |
405 | ";; Unable to prove that the loop iterates constant times\n"); | |
a29c7ea6 ZD |
406 | return; |
407 | } | |
408 | ||
e598c332 JH |
409 | /* Check whether the loop rolls enough to consider. |
410 | Consult also loop bounds and profile; in the case the loop has more | |
411 | than one exit it may well loop less than determined maximal number | |
412 | of iterations. */ | |
413 | if (desc->niter < 2 * nunroll | |
71343877 AM |
414 | || ((get_estimated_loop_iterations (loop, &iterations) |
415 | || get_max_loop_iterations (loop, &iterations)) | |
807e902e | 416 | && wi::ltu_p (iterations, 2 * nunroll))) |
a29c7ea6 | 417 | { |
c263766c RH |
418 | if (dump_file) |
419 | fprintf (dump_file, ";; Not unrolling loop, doesn't roll\n"); | |
a29c7ea6 ZD |
420 | return; |
421 | } | |
422 | ||
423 | /* Success; now compute number of iterations to unroll. We alter | |
424 | nunroll so that as few as possible copies of loop body are | |
e0bb17a8 | 425 | necessary, while still not decreasing the number of unrollings |
a29c7ea6 ZD |
426 | too much (at most by 1). */ |
427 | best_copies = 2 * nunroll + 10; | |
428 | ||
429 | i = 2 * nunroll + 2; | |
50654f6c ZD |
430 | if (i - 1 >= desc->niter) |
431 | i = desc->niter - 2; | |
a29c7ea6 ZD |
432 | |
433 | for (; i >= nunroll - 1; i--) | |
434 | { | |
50654f6c | 435 | unsigned exit_mod = desc->niter % (i + 1); |
a29c7ea6 | 436 | |
50654f6c | 437 | if (!loop_exit_at_end_p (loop)) |
a29c7ea6 | 438 | n_copies = exit_mod + i + 1; |
50654f6c ZD |
439 | else if (exit_mod != (unsigned) i |
440 | || desc->noloop_assumptions != NULL_RTX) | |
a29c7ea6 ZD |
441 | n_copies = exit_mod + i + 2; |
442 | else | |
443 | n_copies = i + 1; | |
444 | ||
445 | if (n_copies < best_copies) | |
446 | { | |
447 | best_copies = n_copies; | |
448 | best_unroll = i; | |
449 | } | |
450 | } | |
451 | ||
a29c7ea6 ZD |
452 | loop->lpt_decision.decision = LPT_UNROLL_CONSTANT; |
453 | loop->lpt_decision.times = best_unroll; | |
454 | } | |
455 | ||
4fc2e37d EB |
456 | /* Unroll LOOP with constant number of iterations LOOP->LPT_DECISION.TIMES times. |
457 | The transformation does this: | |
0c20a65f | 458 | |
a29c7ea6 ZD |
459 | for (i = 0; i < 102; i++) |
460 | body; | |
0c20a65f | 461 | |
4fc2e37d | 462 | ==> (LOOP->LPT_DECISION.TIMES == 3) |
0c20a65f | 463 | |
a29c7ea6 ZD |
464 | i = 0; |
465 | body; i++; | |
466 | body; i++; | |
467 | while (i < 102) | |
468 | { | |
469 | body; i++; | |
470 | body; i++; | |
471 | body; i++; | |
472 | body; i++; | |
473 | } | |
474 | */ | |
475 | static void | |
d73be268 | 476 | unroll_loop_constant_iterations (struct loop *loop) |
a29c7ea6 ZD |
477 | { |
478 | unsigned HOST_WIDE_INT niter; | |
479 | unsigned exit_mod; | |
480 | sbitmap wont_exit; | |
ee8c1b05 | 481 | unsigned i; |
ee8c1b05 | 482 | edge e; |
a29c7ea6 | 483 | unsigned max_unroll = loop->lpt_decision.times; |
50654f6c ZD |
484 | struct niter_desc *desc = get_simple_loop_desc (loop); |
485 | bool exit_at_end = loop_exit_at_end_p (loop); | |
f37a4f14 | 486 | struct opt_info *opt_info = NULL; |
41806d92 | 487 | bool ok; |
b8698a0f | 488 | |
a29c7ea6 ZD |
489 | niter = desc->niter; |
490 | ||
113d659a ZD |
491 | /* Should not get here (such loop should be peeled instead). */ |
492 | gcc_assert (niter > max_unroll + 1); | |
a29c7ea6 ZD |
493 | |
494 | exit_mod = niter % (max_unroll + 1); | |
495 | ||
496 | wont_exit = sbitmap_alloc (max_unroll + 1); | |
f61e445a | 497 | bitmap_ones (wont_exit); |
a29c7ea6 | 498 | |
ef062b13 | 499 | auto_vec<edge> remove_edges; |
b8698a0f | 500 | if (flag_split_ivs_in_unroller |
f37a4f14 RE |
501 | || flag_variable_expansion_in_unroller) |
502 | opt_info = analyze_insns_in_loop (loop); | |
b8698a0f | 503 | |
50654f6c | 504 | if (!exit_at_end) |
a29c7ea6 | 505 | { |
50654f6c | 506 | /* The exit is not at the end of the loop; leave exit test |
a29c7ea6 ZD |
507 | in the first copy, so that the loops that start with test |
508 | of exit condition have continuous body after unrolling. */ | |
509 | ||
c263766c | 510 | if (dump_file) |
4fc2e37d | 511 | fprintf (dump_file, ";; Condition at beginning of loop.\n"); |
a29c7ea6 ZD |
512 | |
513 | /* Peel exit_mod iterations. */ | |
d7c028c0 | 514 | bitmap_clear_bit (wont_exit, 0); |
50654f6c | 515 | if (desc->noloop_assumptions) |
d7c028c0 | 516 | bitmap_clear_bit (wont_exit, 1); |
a29c7ea6 | 517 | |
50654f6c ZD |
518 | if (exit_mod) |
519 | { | |
f37a4f14 | 520 | opt_info_start_duplication (opt_info); |
41806d92 | 521 | ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop), |
d73be268 | 522 | exit_mod, |
50654f6c | 523 | wont_exit, desc->out_edge, |
ee8c1b05 | 524 | &remove_edges, |
7f7b1718 JH |
525 | DLTHE_FLAG_UPDATE_FREQ |
526 | | (opt_info && exit_mod > 1 | |
527 | ? DLTHE_RECORD_COPY_NUMBER | |
528 | : 0)); | |
41806d92 | 529 | gcc_assert (ok); |
50654f6c | 530 | |
f37a4f14 | 531 | if (opt_info && exit_mod > 1) |
b8698a0f L |
532 | apply_opt_in_copies (opt_info, exit_mod, false, false); |
533 | ||
50654f6c ZD |
534 | desc->noloop_assumptions = NULL_RTX; |
535 | desc->niter -= exit_mod; | |
807e902e | 536 | loop->nb_iterations_upper_bound -= exit_mod; |
e3a8f1fa | 537 | if (loop->any_estimate |
807e902e KZ |
538 | && wi::leu_p (exit_mod, loop->nb_iterations_estimate)) |
539 | loop->nb_iterations_estimate -= exit_mod; | |
e3a8f1fa JH |
540 | else |
541 | loop->any_estimate = false; | |
50654f6c | 542 | } |
a29c7ea6 | 543 | |
d7c028c0 | 544 | bitmap_set_bit (wont_exit, 1); |
a29c7ea6 ZD |
545 | } |
546 | else | |
547 | { | |
548 | /* Leave exit test in last copy, for the same reason as above if | |
549 | the loop tests the condition at the end of loop body. */ | |
550 | ||
c263766c | 551 | if (dump_file) |
4fc2e37d | 552 | fprintf (dump_file, ";; Condition at end of loop.\n"); |
a29c7ea6 ZD |
553 | |
554 | /* We know that niter >= max_unroll + 2; so we do not need to care of | |
555 | case when we would exit before reaching the loop. So just peel | |
50654f6c ZD |
556 | exit_mod + 1 iterations. */ |
557 | if (exit_mod != max_unroll | |
558 | || desc->noloop_assumptions) | |
a29c7ea6 | 559 | { |
d7c028c0 | 560 | bitmap_clear_bit (wont_exit, 0); |
50654f6c | 561 | if (desc->noloop_assumptions) |
d7c028c0 | 562 | bitmap_clear_bit (wont_exit, 1); |
b8698a0f | 563 | |
f37a4f14 | 564 | opt_info_start_duplication (opt_info); |
41806d92 | 565 | ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop), |
d73be268 | 566 | exit_mod + 1, |
41806d92 | 567 | wont_exit, desc->out_edge, |
ee8c1b05 | 568 | &remove_edges, |
7f7b1718 JH |
569 | DLTHE_FLAG_UPDATE_FREQ |
570 | | (opt_info && exit_mod > 0 | |
571 | ? DLTHE_RECORD_COPY_NUMBER | |
572 | : 0)); | |
41806d92 | 573 | gcc_assert (ok); |
b8698a0f | 574 | |
f37a4f14 RE |
575 | if (opt_info && exit_mod > 0) |
576 | apply_opt_in_copies (opt_info, exit_mod + 1, false, false); | |
113d659a | 577 | |
50654f6c | 578 | desc->niter -= exit_mod + 1; |
807e902e | 579 | loop->nb_iterations_upper_bound -= exit_mod + 1; |
e3a8f1fa | 580 | if (loop->any_estimate |
807e902e KZ |
581 | && wi::leu_p (exit_mod + 1, loop->nb_iterations_estimate)) |
582 | loop->nb_iterations_estimate -= exit_mod + 1; | |
e3a8f1fa JH |
583 | else |
584 | loop->any_estimate = false; | |
50654f6c ZD |
585 | desc->noloop_assumptions = NULL_RTX; |
586 | ||
d7c028c0 LC |
587 | bitmap_set_bit (wont_exit, 0); |
588 | bitmap_set_bit (wont_exit, 1); | |
a29c7ea6 ZD |
589 | } |
590 | ||
d7c028c0 | 591 | bitmap_clear_bit (wont_exit, max_unroll); |
a29c7ea6 ZD |
592 | } |
593 | ||
594 | /* Now unroll the loop. */ | |
b8698a0f | 595 | |
f37a4f14 | 596 | opt_info_start_duplication (opt_info); |
41806d92 | 597 | ok = duplicate_loop_to_header_edge (loop, loop_latch_edge (loop), |
d73be268 | 598 | max_unroll, |
41806d92 | 599 | wont_exit, desc->out_edge, |
ee8c1b05 | 600 | &remove_edges, |
7f7b1718 JH |
601 | DLTHE_FLAG_UPDATE_FREQ |
602 | | (opt_info | |
603 | ? DLTHE_RECORD_COPY_NUMBER | |
604 | : 0)); | |
41806d92 | 605 | gcc_assert (ok); |
a29c7ea6 | 606 | |
f37a4f14 | 607 | if (opt_info) |
113d659a | 608 | { |
f37a4f14 RE |
609 | apply_opt_in_copies (opt_info, max_unroll, true, true); |
610 | free_opt_info (opt_info); | |
113d659a ZD |
611 | } |
612 | ||
a29c7ea6 ZD |
613 | free (wont_exit); |
614 | ||
50654f6c ZD |
615 | if (exit_at_end) |
616 | { | |
6580ee77 | 617 | basic_block exit_block = get_bb_copy (desc->in_edge->src); |
50654f6c | 618 | /* Find a new in and out edge; they are in the last copy we have made. */ |
b8698a0f | 619 | |
628f6a4e | 620 | if (EDGE_SUCC (exit_block, 0)->dest == desc->out_edge->dest) |
50654f6c | 621 | { |
628f6a4e BE |
622 | desc->out_edge = EDGE_SUCC (exit_block, 0); |
623 | desc->in_edge = EDGE_SUCC (exit_block, 1); | |
50654f6c ZD |
624 | } |
625 | else | |
626 | { | |
628f6a4e BE |
627 | desc->out_edge = EDGE_SUCC (exit_block, 1); |
628 | desc->in_edge = EDGE_SUCC (exit_block, 0); | |
50654f6c ZD |
629 | } |
630 | } | |
631 | ||
632 | desc->niter /= max_unroll + 1; | |
e3a8f1fa | 633 | loop->nb_iterations_upper_bound |
807e902e | 634 | = wi::udiv_trunc (loop->nb_iterations_upper_bound, max_unroll + 1); |
e3a8f1fa JH |
635 | if (loop->any_estimate) |
636 | loop->nb_iterations_estimate | |
807e902e | 637 | = wi::udiv_trunc (loop->nb_iterations_estimate, max_unroll + 1); |
50654f6c ZD |
638 | desc->niter_expr = GEN_INT (desc->niter); |
639 | ||
a29c7ea6 | 640 | /* Remove the edges. */ |
9771b263 | 641 | FOR_EACH_VEC_ELT (remove_edges, i, e) |
ee8c1b05 | 642 | remove_path (e); |
a29c7ea6 | 643 | |
c263766c RH |
644 | if (dump_file) |
645 | fprintf (dump_file, | |
646 | ";; Unrolled loop %d times, constant # of iterations %i insns\n", | |
647 | max_unroll, num_loop_insns (loop)); | |
a29c7ea6 ZD |
648 | } |
649 | ||
650 | /* Decide whether to unroll LOOP iterating runtime computable number of times | |
651 | and how much. */ | |
652 | static void | |
d47cc544 | 653 | decide_unroll_runtime_iterations (struct loop *loop, int flags) |
a29c7ea6 ZD |
654 | { |
655 | unsigned nunroll, nunroll_by_av, i; | |
50654f6c | 656 | struct niter_desc *desc; |
807e902e | 657 | widest_int iterations; |
a29c7ea6 ZD |
658 | |
659 | if (!(flags & UAP_UNROLL)) | |
660 | { | |
661 | /* We were not asked to, just return back silently. */ | |
662 | return; | |
663 | } | |
664 | ||
c263766c RH |
665 | if (dump_file) |
666 | fprintf (dump_file, | |
667 | "\n;; Considering unrolling loop with runtime " | |
668 | "computable number of iterations\n"); | |
a29c7ea6 ZD |
669 | |
670 | /* nunroll = total number of copies of the original loop body in | |
671 | unrolled loop (i.e. if it is 2, we have to duplicate loop body once. */ | |
672 | nunroll = PARAM_VALUE (PARAM_MAX_UNROLLED_INSNS) / loop->ninsns; | |
673 | nunroll_by_av = PARAM_VALUE (PARAM_MAX_AVERAGE_UNROLLED_INSNS) / loop->av_ninsns; | |
674 | if (nunroll > nunroll_by_av) | |
675 | nunroll = nunroll_by_av; | |
676 | if (nunroll > (unsigned) PARAM_VALUE (PARAM_MAX_UNROLL_TIMES)) | |
677 | nunroll = PARAM_VALUE (PARAM_MAX_UNROLL_TIMES); | |
678 | ||
40ac4f73 CB |
679 | if (targetm.loop_unroll_adjust) |
680 | nunroll = targetm.loop_unroll_adjust (nunroll, loop); | |
681 | ||
a29c7ea6 ZD |
682 | /* Skip big loops. */ |
683 | if (nunroll <= 1) | |
684 | { | |
c263766c RH |
685 | if (dump_file) |
686 | fprintf (dump_file, ";; Not considering loop, is too big\n"); | |
a29c7ea6 ZD |
687 | return; |
688 | } | |
689 | ||
690 | /* Check for simple loops. */ | |
50654f6c | 691 | desc = get_simple_loop_desc (loop); |
a29c7ea6 ZD |
692 | |
693 | /* Check simpleness. */ | |
50654f6c | 694 | if (!desc->simple_p || desc->assumptions) |
a29c7ea6 | 695 | { |
c263766c RH |
696 | if (dump_file) |
697 | fprintf (dump_file, | |
698 | ";; Unable to prove that the number of iterations " | |
699 | "can be counted in runtime\n"); | |
a29c7ea6 ZD |
700 | return; |
701 | } | |
702 | ||
50654f6c | 703 | if (desc->const_iter) |
a29c7ea6 | 704 | { |
c263766c RH |
705 | if (dump_file) |
706 | fprintf (dump_file, ";; Loop iterates constant times\n"); | |
a29c7ea6 ZD |
707 | return; |
708 | } | |
709 | ||
73367f92 | 710 | /* Check whether the loop rolls. */ |
71343877 AM |
711 | if ((get_estimated_loop_iterations (loop, &iterations) |
712 | || get_max_loop_iterations (loop, &iterations)) | |
807e902e | 713 | && wi::ltu_p (iterations, 2 * nunroll)) |
a29c7ea6 | 714 | { |
c263766c RH |
715 | if (dump_file) |
716 | fprintf (dump_file, ";; Not unrolling loop, doesn't roll\n"); | |
a29c7ea6 ZD |
717 | return; |
718 | } | |
719 | ||
720 | /* Success; now force nunroll to be power of 2, as we are unable to | |
721 | cope with overflows in computation of number of iterations. */ | |
50654f6c ZD |
722 | for (i = 1; 2 * i <= nunroll; i *= 2) |
723 | continue; | |
a29c7ea6 ZD |
724 | |
725 | loop->lpt_decision.decision = LPT_UNROLL_RUNTIME; | |
726 | loop->lpt_decision.times = i - 1; | |
727 | } | |
728 | ||
7d93d987 ZD |
729 | /* Splits edge E and inserts the sequence of instructions INSNS on it, and |
730 | returns the newly created block. If INSNS is NULL_RTX, nothing is changed | |
731 | and NULL is returned instead. */ | |
598ec7bd ZD |
732 | |
733 | basic_block | |
95ecfb26 | 734 | split_edge_and_insert (edge e, rtx_insn *insns) |
598ec7bd | 735 | { |
7d93d987 ZD |
736 | basic_block bb; |
737 | ||
738 | if (!insns) | |
739 | return NULL; | |
b8698a0f | 740 | bb = split_edge (e); |
598ec7bd | 741 | emit_insn_after (insns, BB_END (bb)); |
7984c787 SB |
742 | |
743 | /* ??? We used to assume that INSNS can contain control flow insns, and | |
744 | that we had to try to find sub basic blocks in BB to maintain a valid | |
745 | CFG. For this purpose we used to set the BB_SUPERBLOCK flag on BB | |
746 | and call break_superblocks when going out of cfglayout mode. But it | |
747 | turns out that this never happens; and that if it does ever happen, | |
3bea341f | 748 | the verify_flow_info at the end of the RTL loop passes would fail. |
7984c787 SB |
749 | |
750 | There are two reasons why we expected we could have control flow insns | |
751 | in INSNS. The first is when a comparison has to be done in parts, and | |
752 | the second is when the number of iterations is computed for loops with | |
753 | the number of iterations known at runtime. In both cases, test cases | |
754 | to get control flow in INSNS appear to be impossible to construct: | |
755 | ||
756 | * If do_compare_rtx_and_jump needs several branches to do comparison | |
757 | in a mode that needs comparison by parts, we cannot analyze the | |
758 | number of iterations of the loop, and we never get to unrolling it. | |
759 | ||
760 | * The code in expand_divmod that was suspected to cause creation of | |
761 | branching code seems to be only accessed for signed division. The | |
762 | divisions used by # of iterations analysis are always unsigned. | |
763 | Problems might arise on architectures that emits branching code | |
764 | for some operations that may appear in the unroller (especially | |
765 | for division), but we have no such architectures. | |
766 | ||
767 | Considering all this, it was decided that we should for now assume | |
768 | that INSNS can in theory contain control flow insns, but in practice | |
769 | it never does. So we don't handle the theoretical case, and should | |
770 | a real failure ever show up, we have a pretty good clue for how to | |
771 | fix it. */ | |
772 | ||
598ec7bd ZD |
773 | return bb; |
774 | } | |
775 | ||
da4cfeac RB |
776 | /* Prepare a sequence comparing OP0 with OP1 using COMP and jumping to LABEL if |
777 | true, with probability PROB. If CINSN is not NULL, it is the insn to copy | |
778 | in order to create a jump. */ | |
779 | ||
95ecfb26 | 780 | static rtx_insn * |
1476d1bd MM |
781 | compare_and_jump_seq (rtx op0, rtx op1, enum rtx_code comp, |
782 | rtx_code_label *label, int prob, rtx_insn *cinsn) | |
da4cfeac | 783 | { |
1476d1bd MM |
784 | rtx_insn *seq; |
785 | rtx_jump_insn *jump; | |
95ecfb26 | 786 | rtx cond; |
ef4bddc2 | 787 | machine_mode mode; |
da4cfeac RB |
788 | |
789 | mode = GET_MODE (op0); | |
790 | if (mode == VOIDmode) | |
791 | mode = GET_MODE (op1); | |
792 | ||
793 | start_sequence (); | |
794 | if (GET_MODE_CLASS (mode) == MODE_CC) | |
795 | { | |
796 | /* A hack -- there seems to be no easy generic way how to make a | |
797 | conditional jump from a ccmode comparison. */ | |
798 | gcc_assert (cinsn); | |
799 | cond = XEXP (SET_SRC (pc_set (cinsn)), 0); | |
800 | gcc_assert (GET_CODE (cond) == comp); | |
801 | gcc_assert (rtx_equal_p (op0, XEXP (cond, 0))); | |
802 | gcc_assert (rtx_equal_p (op1, XEXP (cond, 1))); | |
803 | emit_jump_insn (copy_insn (PATTERN (cinsn))); | |
1476d1bd | 804 | jump = as_a <rtx_jump_insn *> (get_last_insn ()); |
da4cfeac RB |
805 | JUMP_LABEL (jump) = JUMP_LABEL (cinsn); |
806 | LABEL_NUSES (JUMP_LABEL (jump))++; | |
807 | redirect_jump (jump, label, 0); | |
808 | } | |
809 | else | |
810 | { | |
811 | gcc_assert (!cinsn); | |
812 | ||
813 | op0 = force_operand (op0, NULL_RTX); | |
814 | op1 = force_operand (op1, NULL_RTX); | |
815 | do_compare_rtx_and_jump (op0, op1, comp, 0, | |
1476d1bd MM |
816 | mode, NULL_RTX, NULL, label, -1); |
817 | jump = as_a <rtx_jump_insn *> (get_last_insn ()); | |
818 | jump->set_jump_target (label); | |
da4cfeac RB |
819 | LABEL_NUSES (label)++; |
820 | } | |
821 | add_int_reg_note (jump, REG_BR_PROB, prob); | |
822 | ||
823 | seq = get_insns (); | |
824 | end_sequence (); | |
825 | ||
826 | return seq; | |
827 | } | |
828 | ||
4fc2e37d EB |
829 | /* Unroll LOOP for which we are able to count number of iterations in runtime |
830 | LOOP->LPT_DECISION.TIMES times. The transformation does this (with some | |
a29c7ea6 | 831 | extra care for case n < 0): |
0c20a65f | 832 | |
a29c7ea6 ZD |
833 | for (i = 0; i < n; i++) |
834 | body; | |
0c20a65f | 835 | |
4fc2e37d | 836 | ==> (LOOP->LPT_DECISION.TIMES == 3) |
0c20a65f | 837 | |
a29c7ea6 ZD |
838 | i = 0; |
839 | mod = n % 4; | |
0c20a65f | 840 | |
a29c7ea6 ZD |
841 | switch (mod) |
842 | { | |
843 | case 3: | |
844 | body; i++; | |
845 | case 2: | |
846 | body; i++; | |
847 | case 1: | |
848 | body; i++; | |
849 | case 0: ; | |
850 | } | |
0c20a65f | 851 | |
a29c7ea6 ZD |
852 | while (i < n) |
853 | { | |
854 | body; i++; | |
855 | body; i++; | |
856 | body; i++; | |
857 | body; i++; | |
858 | } | |
859 | */ | |
860 | static void | |
d73be268 | 861 | unroll_loop_runtime_iterations (struct loop *loop) |
a29c7ea6 | 862 | { |
95ecfb26 DM |
863 | rtx old_niter, niter, tmp; |
864 | rtx_insn *init_code, *branch_code; | |
a29c7ea6 | 865 | unsigned i, j, p; |
66f97d31 | 866 | basic_block preheader, *body, swtch, ezc_swtch; |
a29c7ea6 ZD |
867 | sbitmap wont_exit; |
868 | int may_exit_copy; | |
ee8c1b05 | 869 | unsigned n_peel; |
ee8c1b05 | 870 | edge e; |
a29c7ea6 ZD |
871 | bool extra_zero_check, last_may_exit; |
872 | unsigned max_unroll = loop->lpt_decision.times; | |
50654f6c ZD |
873 | struct niter_desc *desc = get_simple_loop_desc (loop); |
874 | bool exit_at_end = loop_exit_at_end_p (loop); | |
f37a4f14 | 875 | struct opt_info *opt_info = NULL; |
41806d92 | 876 | bool ok; |
b8698a0f | 877 | |
f37a4f14 RE |
878 | if (flag_split_ivs_in_unroller |
879 | || flag_variable_expansion_in_unroller) | |
880 | opt_info = analyze_insns_in_loop (loop); | |
b8698a0f | 881 | |
a29c7ea6 | 882 | /* Remember blocks whose dominators will have to be updated. */ |
ef062b13 | 883 | auto_vec<basic_block> dom_bbs; |
a29c7ea6 ZD |
884 | |
885 | body = get_loop_body (loop); | |
886 | for (i = 0; i < loop->num_nodes; i++) | |
887 | { | |
9771b263 | 888 | vec<basic_block> ldom; |
66f97d31 | 889 | basic_block bb; |
a29c7ea6 | 890 | |
66f97d31 | 891 | ldom = get_dominated_by (CDI_DOMINATORS, body[i]); |
9771b263 | 892 | FOR_EACH_VEC_ELT (ldom, j, bb) |
66f97d31 | 893 | if (!flow_bb_inside_loop_p (loop, bb)) |
9771b263 | 894 | dom_bbs.safe_push (bb); |
a29c7ea6 | 895 | |
9771b263 | 896 | ldom.release (); |
a29c7ea6 ZD |
897 | } |
898 | free (body); | |
899 | ||
50654f6c | 900 | if (!exit_at_end) |
a29c7ea6 ZD |
901 | { |
902 | /* Leave exit in first copy (for explanation why see comment in | |
903 | unroll_loop_constant_iterations). */ | |
904 | may_exit_copy = 0; | |
905 | n_peel = max_unroll - 1; | |
906 | extra_zero_check = true; | |
907 | last_may_exit = false; | |
908 | } | |
909 | else | |
910 | { | |
911 | /* Leave exit in last copy (for explanation why see comment in | |
912 | unroll_loop_constant_iterations). */ | |
913 | may_exit_copy = max_unroll; | |
914 | n_peel = max_unroll; | |
915 | extra_zero_check = false; | |
916 | last_may_exit = true; | |
917 | } | |
918 | ||
919 | /* Get expression for number of iterations. */ | |
920 | start_sequence (); | |
50654f6c ZD |
921 | old_niter = niter = gen_reg_rtx (desc->mode); |
922 | tmp = force_operand (copy_rtx (desc->niter_expr), niter); | |
923 | if (tmp != niter) | |
924 | emit_move_insn (niter, tmp); | |
a29c7ea6 ZD |
925 | |
926 | /* Count modulo by ANDing it with max_unroll; we use the fact that | |
927 | the number of unrollings is a power of two, and thus this is correct | |
928 | even if there is overflow in the computation. */ | |
50654f6c | 929 | niter = expand_simple_binop (desc->mode, AND, |
2f1cd2eb | 930 | niter, gen_int_mode (max_unroll, desc->mode), |
a29c7ea6 ZD |
931 | NULL_RTX, 0, OPTAB_LIB_WIDEN); |
932 | ||
933 | init_code = get_insns (); | |
934 | end_sequence (); | |
2ed22578 | 935 | unshare_all_rtl_in_chain (init_code); |
a29c7ea6 ZD |
936 | |
937 | /* Precondition the loop. */ | |
598ec7bd | 938 | split_edge_and_insert (loop_preheader_edge (loop), init_code); |
a29c7ea6 | 939 | |
ef062b13 | 940 | auto_vec<edge> remove_edges; |
a29c7ea6 ZD |
941 | |
942 | wont_exit = sbitmap_alloc (max_unroll + 2); | |
943 | ||
944 | /* Peel the first copy of loop body (almost always we must leave exit test | |
945 | here; the only exception is when we have extra zero check and the number | |
50654f6c ZD |
946 | of iterations is reliable. Also record the place of (possible) extra |
947 | zero check. */ | |
f61e445a | 948 | bitmap_clear (wont_exit); |
50654f6c ZD |
949 | if (extra_zero_check |
950 | && !desc->noloop_assumptions) | |
d7c028c0 | 951 | bitmap_set_bit (wont_exit, 1); |
a29c7ea6 | 952 | ezc_swtch = loop_preheader_edge (loop)->src; |
41806d92 | 953 | ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop), |
d73be268 | 954 | 1, wont_exit, desc->out_edge, |
ee8c1b05 | 955 | &remove_edges, |
41806d92 NS |
956 | DLTHE_FLAG_UPDATE_FREQ); |
957 | gcc_assert (ok); | |
a29c7ea6 ZD |
958 | |
959 | /* Record the place where switch will be built for preconditioning. */ | |
598ec7bd | 960 | swtch = split_edge (loop_preheader_edge (loop)); |
a29c7ea6 ZD |
961 | |
962 | for (i = 0; i < n_peel; i++) | |
963 | { | |
964 | /* Peel the copy. */ | |
f61e445a | 965 | bitmap_clear (wont_exit); |
a29c7ea6 | 966 | if (i != n_peel - 1 || !last_may_exit) |
d7c028c0 | 967 | bitmap_set_bit (wont_exit, 1); |
41806d92 | 968 | ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop), |
d73be268 | 969 | 1, wont_exit, desc->out_edge, |
ee8c1b05 | 970 | &remove_edges, |
41806d92 NS |
971 | DLTHE_FLAG_UPDATE_FREQ); |
972 | gcc_assert (ok); | |
a29c7ea6 | 973 | |
91f4cfe3 ZD |
974 | /* Create item for switch. */ |
975 | j = n_peel - i - (extra_zero_check ? 0 : 1); | |
976 | p = REG_BR_PROB_BASE / (i + 2); | |
977 | ||
598ec7bd | 978 | preheader = split_edge (loop_preheader_edge (loop)); |
50654f6c | 979 | branch_code = compare_and_jump_seq (copy_rtx (niter), GEN_INT (j), EQ, |
41806d92 | 980 | block_label (preheader), p, |
95ecfb26 | 981 | NULL); |
91f4cfe3 | 982 | |
7d93d987 ZD |
983 | /* We rely on the fact that the compare and jump cannot be optimized out, |
984 | and hence the cfg we create is correct. */ | |
985 | gcc_assert (branch_code != NULL_RTX); | |
986 | ||
598ec7bd | 987 | swtch = split_edge_and_insert (single_pred_edge (swtch), branch_code); |
d47cc544 | 988 | set_immediate_dominator (CDI_DOMINATORS, preheader, swtch); |
c5cbcccf | 989 | single_pred_edge (swtch)->probability = REG_BR_PROB_BASE - p; |
91f4cfe3 | 990 | e = make_edge (swtch, preheader, |
c5cbcccf | 991 | single_succ_edge (swtch)->flags & EDGE_IRREDUCIBLE_LOOP); |
e3a8f1fa | 992 | e->count = RDIV (preheader->count * REG_BR_PROB_BASE, p); |
91f4cfe3 | 993 | e->probability = p; |
a29c7ea6 ZD |
994 | } |
995 | ||
996 | if (extra_zero_check) | |
997 | { | |
998 | /* Add branch for zero iterations. */ | |
999 | p = REG_BR_PROB_BASE / (max_unroll + 1); | |
1000 | swtch = ezc_swtch; | |
598ec7bd | 1001 | preheader = split_edge (loop_preheader_edge (loop)); |
50654f6c | 1002 | branch_code = compare_and_jump_seq (copy_rtx (niter), const0_rtx, EQ, |
41806d92 | 1003 | block_label (preheader), p, |
95ecfb26 | 1004 | NULL); |
7d93d987 | 1005 | gcc_assert (branch_code != NULL_RTX); |
a29c7ea6 | 1006 | |
598ec7bd | 1007 | swtch = split_edge_and_insert (single_succ_edge (swtch), branch_code); |
d47cc544 | 1008 | set_immediate_dominator (CDI_DOMINATORS, preheader, swtch); |
c5cbcccf | 1009 | single_succ_edge (swtch)->probability = REG_BR_PROB_BASE - p; |
72b8d451 | 1010 | e = make_edge (swtch, preheader, |
c5cbcccf | 1011 | single_succ_edge (swtch)->flags & EDGE_IRREDUCIBLE_LOOP); |
e3a8f1fa | 1012 | e->count = RDIV (preheader->count * REG_BR_PROB_BASE, p); |
a29c7ea6 ZD |
1013 | e->probability = p; |
1014 | } | |
1015 | ||
1016 | /* Recount dominators for outer blocks. */ | |
66f97d31 | 1017 | iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, false); |
a29c7ea6 ZD |
1018 | |
1019 | /* And unroll loop. */ | |
1020 | ||
f61e445a | 1021 | bitmap_ones (wont_exit); |
d7c028c0 | 1022 | bitmap_clear_bit (wont_exit, may_exit_copy); |
f37a4f14 | 1023 | opt_info_start_duplication (opt_info); |
b8698a0f | 1024 | |
41806d92 | 1025 | ok = duplicate_loop_to_header_edge (loop, loop_latch_edge (loop), |
d73be268 | 1026 | max_unroll, |
41806d92 | 1027 | wont_exit, desc->out_edge, |
ee8c1b05 | 1028 | &remove_edges, |
7f7b1718 JH |
1029 | DLTHE_FLAG_UPDATE_FREQ |
1030 | | (opt_info | |
1031 | ? DLTHE_RECORD_COPY_NUMBER | |
1032 | : 0)); | |
41806d92 | 1033 | gcc_assert (ok); |
b8698a0f | 1034 | |
f37a4f14 | 1035 | if (opt_info) |
113d659a | 1036 | { |
f37a4f14 RE |
1037 | apply_opt_in_copies (opt_info, max_unroll, true, true); |
1038 | free_opt_info (opt_info); | |
113d659a ZD |
1039 | } |
1040 | ||
a29c7ea6 ZD |
1041 | free (wont_exit); |
1042 | ||
50654f6c ZD |
1043 | if (exit_at_end) |
1044 | { | |
6580ee77 | 1045 | basic_block exit_block = get_bb_copy (desc->in_edge->src); |
41806d92 NS |
1046 | /* Find a new in and out edge; they are in the last copy we have |
1047 | made. */ | |
b8698a0f | 1048 | |
628f6a4e | 1049 | if (EDGE_SUCC (exit_block, 0)->dest == desc->out_edge->dest) |
50654f6c | 1050 | { |
628f6a4e BE |
1051 | desc->out_edge = EDGE_SUCC (exit_block, 0); |
1052 | desc->in_edge = EDGE_SUCC (exit_block, 1); | |
50654f6c ZD |
1053 | } |
1054 | else | |
1055 | { | |
628f6a4e BE |
1056 | desc->out_edge = EDGE_SUCC (exit_block, 1); |
1057 | desc->in_edge = EDGE_SUCC (exit_block, 0); | |
50654f6c ZD |
1058 | } |
1059 | } | |
1060 | ||
a29c7ea6 | 1061 | /* Remove the edges. */ |
9771b263 | 1062 | FOR_EACH_VEC_ELT (remove_edges, i, e) |
ee8c1b05 | 1063 | remove_path (e); |
a29c7ea6 | 1064 | |
50654f6c ZD |
1065 | /* We must be careful when updating the number of iterations due to |
1066 | preconditioning and the fact that the value must be valid at entry | |
1067 | of the loop. After passing through the above code, we see that | |
1068 | the correct new number of iterations is this: */ | |
113d659a | 1069 | gcc_assert (!desc->const_iter); |
50654f6c | 1070 | desc->niter_expr = |
41806d92 | 1071 | simplify_gen_binary (UDIV, desc->mode, old_niter, |
69a59f0f | 1072 | gen_int_mode (max_unroll + 1, desc->mode)); |
e3a8f1fa | 1073 | loop->nb_iterations_upper_bound |
807e902e | 1074 | = wi::udiv_trunc (loop->nb_iterations_upper_bound, max_unroll + 1); |
e3a8f1fa JH |
1075 | if (loop->any_estimate) |
1076 | loop->nb_iterations_estimate | |
807e902e | 1077 | = wi::udiv_trunc (loop->nb_iterations_estimate, max_unroll + 1); |
50654f6c ZD |
1078 | if (exit_at_end) |
1079 | { | |
1080 | desc->niter_expr = | |
1081 | simplify_gen_binary (MINUS, desc->mode, desc->niter_expr, const1_rtx); | |
1082 | desc->noloop_assumptions = NULL_RTX; | |
e3a8f1fa JH |
1083 | --loop->nb_iterations_upper_bound; |
1084 | if (loop->any_estimate | |
807e902e | 1085 | && loop->nb_iterations_estimate != 0) |
e3a8f1fa JH |
1086 | --loop->nb_iterations_estimate; |
1087 | else | |
1088 | loop->any_estimate = 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 AM |
1159 | if ((get_estimated_loop_iterations (loop, &iterations) |
1160 | || get_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 ZD |
1198 | { |
1199 | sbitmap wont_exit; | |
1200 | unsigned nunroll = loop->lpt_decision.times; | |
50654f6c | 1201 | struct niter_desc *desc = get_simple_loop_desc (loop); |
f37a4f14 | 1202 | struct opt_info *opt_info = NULL; |
41806d92 | 1203 | bool ok; |
b8698a0f | 1204 | |
f37a4f14 RE |
1205 | if (flag_split_ivs_in_unroller |
1206 | || flag_variable_expansion_in_unroller) | |
1207 | opt_info = analyze_insns_in_loop (loop); | |
b8698a0f L |
1208 | |
1209 | ||
a29c7ea6 | 1210 | wont_exit = sbitmap_alloc (nunroll + 1); |
f61e445a | 1211 | bitmap_clear (wont_exit); |
f37a4f14 | 1212 | opt_info_start_duplication (opt_info); |
b8698a0f | 1213 | |
41806d92 | 1214 | ok = duplicate_loop_to_header_edge (loop, loop_latch_edge (loop), |
d73be268 | 1215 | nunroll, wont_exit, |
ee8c1b05 | 1216 | NULL, NULL, |
7f7b1718 JH |
1217 | DLTHE_FLAG_UPDATE_FREQ |
1218 | | (opt_info | |
1219 | ? DLTHE_RECORD_COPY_NUMBER | |
1220 | : 0)); | |
41806d92 | 1221 | gcc_assert (ok); |
b8698a0f | 1222 | |
f37a4f14 | 1223 | if (opt_info) |
113d659a | 1224 | { |
f37a4f14 RE |
1225 | apply_opt_in_copies (opt_info, nunroll, true, true); |
1226 | free_opt_info (opt_info); | |
113d659a ZD |
1227 | } |
1228 | ||
a29c7ea6 | 1229 | free (wont_exit); |
0c20a65f | 1230 | |
50654f6c ZD |
1231 | if (desc->simple_p) |
1232 | { | |
1233 | /* We indeed may get here provided that there are nontrivial assumptions | |
1234 | for a loop to be really simple. We could update the counts, but the | |
1235 | problem is that we are unable to decide which exit will be taken | |
1236 | (not really true in case the number of iterations is constant, | |
1aa95df7 | 1237 | but no one will do anything with this information, so we do not |
50654f6c ZD |
1238 | worry about it). */ |
1239 | desc->simple_p = false; | |
1240 | } | |
1241 | ||
c263766c RH |
1242 | if (dump_file) |
1243 | fprintf (dump_file, ";; Unrolled loop %d times, %i insns\n", | |
a29c7ea6 ZD |
1244 | nunroll, num_loop_insns (loop)); |
1245 | } | |
113d659a | 1246 | |
60c48e4c AO |
1247 | /* Returns true if REG is referenced in one nondebug insn in LOOP. |
1248 | Set *DEBUG_USES to the number of debug insns that reference the | |
1249 | variable. */ | |
f37a4f14 | 1250 | |
dd637013 | 1251 | static bool |
60c48e4c AO |
1252 | referenced_in_one_insn_in_loop_p (struct loop *loop, rtx reg, |
1253 | int *debug_uses) | |
f37a4f14 RE |
1254 | { |
1255 | basic_block *body, bb; | |
1256 | unsigned i; | |
1257 | int count_ref = 0; | |
95ecfb26 | 1258 | rtx_insn *insn; |
b8698a0f L |
1259 | |
1260 | body = get_loop_body (loop); | |
f37a4f14 RE |
1261 | for (i = 0; i < loop->num_nodes; i++) |
1262 | { | |
1263 | bb = body[i]; | |
b8698a0f | 1264 | |
f37a4f14 | 1265 | FOR_BB_INSNS (bb, insn) |
60c48e4c AO |
1266 | if (!rtx_referenced_p (reg, insn)) |
1267 | continue; | |
1268 | else if (DEBUG_INSN_P (insn)) | |
1269 | ++*debug_uses; | |
1270 | else if (++count_ref > 1) | |
1271 | break; | |
f37a4f14 | 1272 | } |
60c48e4c | 1273 | free (body); |
f37a4f14 RE |
1274 | return (count_ref == 1); |
1275 | } | |
1276 | ||
60c48e4c AO |
1277 | /* Reset the DEBUG_USES debug insns in LOOP that reference REG. */ |
1278 | ||
1279 | static void | |
1280 | reset_debug_uses_in_loop (struct loop *loop, rtx reg, int debug_uses) | |
1281 | { | |
1282 | basic_block *body, bb; | |
1283 | unsigned i; | |
95ecfb26 | 1284 | rtx_insn *insn; |
60c48e4c AO |
1285 | |
1286 | body = get_loop_body (loop); | |
1287 | for (i = 0; debug_uses && i < loop->num_nodes; i++) | |
1288 | { | |
1289 | bb = body[i]; | |
1290 | ||
1291 | FOR_BB_INSNS (bb, insn) | |
1292 | if (!DEBUG_INSN_P (insn) || !rtx_referenced_p (reg, insn)) | |
1293 | continue; | |
1294 | else | |
1295 | { | |
1296 | validate_change (insn, &INSN_VAR_LOCATION_LOC (insn), | |
1297 | gen_rtx_UNKNOWN_VAR_LOC (), 0); | |
1298 | if (!--debug_uses) | |
1299 | break; | |
1300 | } | |
1301 | } | |
1302 | free (body); | |
1303 | } | |
1304 | ||
f37a4f14 | 1305 | /* Determine whether INSN contains an accumulator |
b8698a0f | 1306 | which can be expanded into separate copies, |
f37a4f14 | 1307 | one for each copy of the LOOP body. |
b8698a0f | 1308 | |
f37a4f14 RE |
1309 | for (i = 0 ; i < n; i++) |
1310 | sum += a[i]; | |
b8698a0f | 1311 | |
f37a4f14 | 1312 | ==> |
b8698a0f | 1313 | |
f37a4f14 RE |
1314 | sum += a[i] |
1315 | .... | |
1316 | i = i+1; | |
1317 | sum1 += a[i] | |
1318 | .... | |
1319 | i = i+1 | |
1320 | sum2 += a[i]; | |
1321 | .... | |
1322 | ||
b8698a0f L |
1323 | Return NULL if INSN contains no opportunity for expansion of accumulator. |
1324 | Otherwise, allocate a VAR_TO_EXPAND structure, fill it with the relevant | |
f37a4f14 RE |
1325 | information and return a pointer to it. |
1326 | */ | |
1327 | ||
1328 | static struct var_to_expand * | |
95ecfb26 | 1329 | analyze_insn_to_expand_var (struct loop *loop, rtx_insn *insn) |
f37a4f14 | 1330 | { |
531e5376 | 1331 | rtx set, dest, src; |
f37a4f14 | 1332 | struct var_to_expand *ves; |
76fd2caa | 1333 | unsigned accum_pos; |
531e5376 | 1334 | enum rtx_code code; |
60c48e4c | 1335 | int debug_uses = 0; |
76fd2caa | 1336 | |
f37a4f14 RE |
1337 | set = single_set (insn); |
1338 | if (!set) | |
1339 | return NULL; | |
b8698a0f | 1340 | |
f37a4f14 RE |
1341 | dest = SET_DEST (set); |
1342 | src = SET_SRC (set); | |
531e5376 | 1343 | code = GET_CODE (src); |
b8698a0f | 1344 | |
531e5376 | 1345 | if (code != PLUS && code != MINUS && code != MULT && code != FMA) |
f37a4f14 | 1346 | return NULL; |
f2dd440f | 1347 | |
531e5376 RH |
1348 | if (FLOAT_MODE_P (GET_MODE (dest))) |
1349 | { | |
1350 | if (!flag_associative_math) | |
1351 | return NULL; | |
1352 | /* In the case of FMA, we're also changing the rounding. */ | |
1353 | if (code == FMA && !flag_unsafe_math_optimizations) | |
1354 | return NULL; | |
1355 | } | |
1356 | ||
f2dd440f SB |
1357 | /* Hmm, this is a bit paradoxical. We know that INSN is a valid insn |
1358 | in MD. But if there is no optab to generate the insn, we can not | |
1359 | perform the variable expansion. This can happen if an MD provides | |
1360 | an insn but not a named pattern to generate it, for example to avoid | |
1361 | producing code that needs additional mode switches like for x87/mmx. | |
1362 | ||
1363 | So we check have_insn_for which looks for an optab for the operation | |
1364 | in SRC. If it doesn't exist, we can't perform the expansion even | |
1365 | though INSN is valid. */ | |
531e5376 | 1366 | if (!have_insn_for (code, GET_MODE (src))) |
f2dd440f SB |
1367 | return NULL; |
1368 | ||
f37a4f14 RE |
1369 | if (!REG_P (dest) |
1370 | && !(GET_CODE (dest) == SUBREG | |
1371 | && REG_P (SUBREG_REG (dest)))) | |
1372 | return NULL; | |
b8698a0f | 1373 | |
531e5376 RH |
1374 | /* Find the accumulator use within the operation. */ |
1375 | if (code == FMA) | |
1376 | { | |
1377 | /* We only support accumulation via FMA in the ADD position. */ | |
1378 | if (!rtx_equal_p (dest, XEXP (src, 2))) | |
1379 | return NULL; | |
1380 | accum_pos = 2; | |
1381 | } | |
1382 | else if (rtx_equal_p (dest, XEXP (src, 0))) | |
76fd2caa | 1383 | accum_pos = 0; |
531e5376 RH |
1384 | else if (rtx_equal_p (dest, XEXP (src, 1))) |
1385 | { | |
1386 | /* The method of expansion that we are using; which includes the | |
1387 | initialization of the expansions with zero and the summation of | |
1388 | the expansions at the end of the computation will yield wrong | |
1389 | results for (x = something - x) thus avoid using it in that case. */ | |
1390 | if (code == MINUS) | |
1391 | return NULL; | |
1392 | accum_pos = 1; | |
1393 | } | |
76fd2caa RE |
1394 | else |
1395 | return NULL; | |
1396 | ||
531e5376 RH |
1397 | /* It must not otherwise be used. */ |
1398 | if (code == FMA) | |
1399 | { | |
1400 | if (rtx_referenced_p (dest, XEXP (src, 0)) | |
1401 | || rtx_referenced_p (dest, XEXP (src, 1))) | |
1402 | return NULL; | |
1403 | } | |
1404 | else if (rtx_referenced_p (dest, XEXP (src, 1 - accum_pos))) | |
f37a4f14 | 1405 | return NULL; |
b8698a0f | 1406 | |
531e5376 | 1407 | /* It must be used in exactly one insn. */ |
60c48e4c | 1408 | if (!referenced_in_one_insn_in_loop_p (loop, dest, &debug_uses)) |
f37a4f14 | 1409 | return NULL; |
b8698a0f | 1410 | |
c1c5a431 | 1411 | if (dump_file) |
531e5376 RH |
1412 | { |
1413 | fprintf (dump_file, "\n;; Expanding Accumulator "); | |
1414 | print_rtl (dump_file, dest); | |
1415 | fprintf (dump_file, "\n"); | |
1416 | } | |
c1c5a431 | 1417 | |
60c48e4c AO |
1418 | if (debug_uses) |
1419 | /* Instead of resetting the debug insns, we could replace each | |
1420 | debug use in the loop with the sum or product of all expanded | |
1421 | accummulators. Since we'll only know of all expansions at the | |
1422 | end, we'd have to keep track of which vars_to_expand a debug | |
1423 | insn in the loop references, take note of each copy of the | |
1424 | debug insn during unrolling, and when it's all done, compute | |
1425 | the sum or product of each variable and adjust the original | |
1426 | debug insn and each copy thereof. What a pain! */ | |
1427 | reset_debug_uses_in_loop (loop, dest, debug_uses); | |
1428 | ||
f37a4f14 | 1429 | /* Record the accumulator to expand. */ |
5ed6ace5 | 1430 | ves = XNEW (struct var_to_expand); |
f37a4f14 | 1431 | ves->insn = insn; |
f37a4f14 | 1432 | ves->reg = copy_rtx (dest); |
9771b263 | 1433 | ves->var_expansions.create (1); |
a9f6ecee | 1434 | ves->next = NULL; |
f37a4f14 RE |
1435 | ves->op = GET_CODE (src); |
1436 | ves->expansion_count = 0; | |
1437 | ves->reuse_expansion = 0; | |
b8698a0f | 1438 | return ves; |
f37a4f14 RE |
1439 | } |
1440 | ||
113d659a | 1441 | /* Determine whether there is an induction variable in INSN that |
b8698a0f | 1442 | we would like to split during unrolling. |
f37a4f14 RE |
1443 | |
1444 | I.e. replace | |
1445 | ||
1446 | i = i + 1; | |
1447 | ... | |
1448 | i = i + 1; | |
1449 | ... | |
1450 | i = i + 1; | |
1451 | ... | |
1452 | ||
1453 | type chains by | |
1454 | ||
1455 | i0 = i + 1 | |
1456 | ... | |
1457 | i = i0 + 1 | |
1458 | ... | |
1459 | i = i0 + 2 | |
1460 | ... | |
1461 | ||
b8698a0f | 1462 | Return NULL if INSN contains no interesting IVs. Otherwise, allocate |
f37a4f14 | 1463 | an IV_TO_SPLIT structure, fill it with the relevant information and return a |
113d659a ZD |
1464 | pointer to it. */ |
1465 | ||
1466 | static struct iv_to_split * | |
1b20d55a | 1467 | analyze_iv_to_split_insn (rtx_insn *insn) |
113d659a ZD |
1468 | { |
1469 | rtx set, dest; | |
1470 | struct rtx_iv iv; | |
1471 | struct iv_to_split *ivts; | |
41806d92 | 1472 | bool ok; |
113d659a ZD |
1473 | |
1474 | /* For now we just split the basic induction variables. Later this may be | |
1475 | extended for example by selecting also addresses of memory references. */ | |
1476 | set = single_set (insn); | |
1477 | if (!set) | |
1478 | return NULL; | |
1479 | ||
1480 | dest = SET_DEST (set); | |
1481 | if (!REG_P (dest)) | |
1482 | return NULL; | |
1483 | ||
1484 | if (!biv_p (insn, dest)) | |
1485 | return NULL; | |
1486 | ||
03fd2215 | 1487 | ok = iv_analyze_result (insn, dest, &iv); |
4dc7782d JL |
1488 | |
1489 | /* This used to be an assert under the assumption that if biv_p returns | |
1490 | true that iv_analyze_result must also return true. However, that | |
1491 | assumption is not strictly correct as evidenced by pr25569. | |
1492 | ||
1493 | Returning NULL when iv_analyze_result returns false is safe and | |
1494 | avoids the problems in pr25569 until the iv_analyze_* routines | |
1495 | can be fixed, which is apparently hard and time consuming | |
1496 | according to their author. */ | |
1497 | if (! ok) | |
1498 | return NULL; | |
113d659a ZD |
1499 | |
1500 | if (iv.step == const0_rtx | |
1501 | || iv.mode != iv.extend_mode) | |
1502 | return NULL; | |
1503 | ||
1504 | /* Record the insn to split. */ | |
5ed6ace5 | 1505 | ivts = XNEW (struct iv_to_split); |
113d659a | 1506 | ivts->insn = insn; |
4a0c3fde | 1507 | ivts->orig_var = dest; |
113d659a ZD |
1508 | ivts->base_var = NULL_RTX; |
1509 | ivts->step = iv.step; | |
a9f6ecee | 1510 | ivts->next = NULL; |
b8698a0f | 1511 | |
113d659a ZD |
1512 | return ivts; |
1513 | } | |
1514 | ||
f37a4f14 RE |
1515 | /* Determines which of insns in LOOP can be optimized. |
1516 | Return a OPT_INFO struct with the relevant hash tables filled | |
1517 | with all insns to be optimized. The FIRST_NEW_BLOCK field | |
113d659a ZD |
1518 | is undefined for the return value. */ |
1519 | ||
f37a4f14 RE |
1520 | static struct opt_info * |
1521 | analyze_insns_in_loop (struct loop *loop) | |
113d659a ZD |
1522 | { |
1523 | basic_block *body, bb; | |
ca83d385 | 1524 | unsigned i; |
5ed6ace5 | 1525 | struct opt_info *opt_info = XCNEW (struct opt_info); |
1b20d55a | 1526 | rtx_insn *insn; |
f37a4f14 RE |
1527 | struct iv_to_split *ivts = NULL; |
1528 | struct var_to_expand *ves = NULL; | |
4a8fb1a1 LC |
1529 | iv_to_split **slot1; |
1530 | var_to_expand **slot2; | |
9771b263 | 1531 | vec<edge> edges = get_loop_exit_edges (loop); |
ca83d385 | 1532 | edge exit; |
f37a4f14 | 1533 | bool can_apply = false; |
b8698a0f | 1534 | |
113d659a ZD |
1535 | iv_analysis_loop_init (loop); |
1536 | ||
1537 | body = get_loop_body (loop); | |
f37a4f14 RE |
1538 | |
1539 | if (flag_split_ivs_in_unroller) | |
a9f6ecee | 1540 | { |
c203e8a7 TS |
1541 | opt_info->insns_to_split |
1542 | = new hash_table<iv_split_hasher> (5 * loop->num_nodes); | |
a9f6ecee AO |
1543 | opt_info->iv_to_split_head = NULL; |
1544 | opt_info->iv_to_split_tail = &opt_info->iv_to_split_head; | |
1545 | } | |
b8698a0f | 1546 | |
f37a4f14 | 1547 | /* Record the loop exit bb and loop preheader before the unrolling. */ |
598ec7bd | 1548 | opt_info->loop_preheader = loop_preheader_edge (loop)->src; |
b8698a0f | 1549 | |
9771b263 | 1550 | if (edges.length () == 1) |
f37a4f14 | 1551 | { |
9771b263 | 1552 | exit = edges[0]; |
ca83d385 ZD |
1553 | if (!(exit->flags & EDGE_COMPLEX)) |
1554 | { | |
1555 | opt_info->loop_exit = split_edge (exit); | |
1556 | can_apply = true; | |
1557 | } | |
f37a4f14 | 1558 | } |
b8698a0f | 1559 | |
f37a4f14 RE |
1560 | if (flag_variable_expansion_in_unroller |
1561 | && can_apply) | |
a9f6ecee | 1562 | { |
c203e8a7 TS |
1563 | opt_info->insns_with_var_to_expand |
1564 | = new hash_table<var_expand_hasher> (5 * loop->num_nodes); | |
a9f6ecee AO |
1565 | opt_info->var_to_expand_head = NULL; |
1566 | opt_info->var_to_expand_tail = &opt_info->var_to_expand_head; | |
1567 | } | |
b8698a0f | 1568 | |
113d659a ZD |
1569 | for (i = 0; i < loop->num_nodes; i++) |
1570 | { | |
1571 | bb = body[i]; | |
1572 | if (!dominated_by_p (CDI_DOMINATORS, loop->latch, bb)) | |
1573 | continue; | |
1574 | ||
1575 | FOR_BB_INSNS (bb, insn) | |
f37a4f14 RE |
1576 | { |
1577 | if (!INSN_P (insn)) | |
1578 | continue; | |
b8698a0f | 1579 | |
c203e8a7 | 1580 | if (opt_info->insns_to_split) |
f37a4f14 | 1581 | ivts = analyze_iv_to_split_insn (insn); |
b8698a0f | 1582 | |
f37a4f14 RE |
1583 | if (ivts) |
1584 | { | |
c203e8a7 | 1585 | slot1 = opt_info->insns_to_split->find_slot (ivts, INSERT); |
a9f6ecee | 1586 | gcc_assert (*slot1 == NULL); |
f37a4f14 | 1587 | *slot1 = ivts; |
a9f6ecee AO |
1588 | *opt_info->iv_to_split_tail = ivts; |
1589 | opt_info->iv_to_split_tail = &ivts->next; | |
f37a4f14 RE |
1590 | continue; |
1591 | } | |
b8698a0f | 1592 | |
c203e8a7 | 1593 | if (opt_info->insns_with_var_to_expand) |
f37a4f14 | 1594 | ves = analyze_insn_to_expand_var (loop, insn); |
b8698a0f | 1595 | |
f37a4f14 RE |
1596 | if (ves) |
1597 | { | |
c203e8a7 | 1598 | slot2 = opt_info->insns_with_var_to_expand->find_slot (ves, INSERT); |
a9f6ecee | 1599 | gcc_assert (*slot2 == NULL); |
f37a4f14 | 1600 | *slot2 = ves; |
a9f6ecee AO |
1601 | *opt_info->var_to_expand_tail = ves; |
1602 | opt_info->var_to_expand_tail = &ves->next; | |
f37a4f14 RE |
1603 | } |
1604 | } | |
113d659a | 1605 | } |
b8698a0f | 1606 | |
9771b263 | 1607 | edges.release (); |
113d659a | 1608 | free (body); |
f37a4f14 | 1609 | return opt_info; |
113d659a ZD |
1610 | } |
1611 | ||
1612 | /* Called just before loop duplication. Records start of duplicated area | |
f37a4f14 | 1613 | to OPT_INFO. */ |
113d659a | 1614 | |
b8698a0f | 1615 | static void |
f37a4f14 | 1616 | opt_info_start_duplication (struct opt_info *opt_info) |
113d659a | 1617 | { |
f37a4f14 | 1618 | if (opt_info) |
8b1c6fd7 | 1619 | opt_info->first_new_block = last_basic_block_for_fn (cfun); |
113d659a ZD |
1620 | } |
1621 | ||
1622 | /* Determine the number of iterations between initialization of the base | |
1623 | variable and the current copy (N_COPY). N_COPIES is the total number | |
1624 | of newly created copies. UNROLLING is true if we are unrolling | |
1625 | (not peeling) the loop. */ | |
1626 | ||
1627 | static unsigned | |
1628 | determine_split_iv_delta (unsigned n_copy, unsigned n_copies, bool unrolling) | |
1629 | { | |
1630 | if (unrolling) | |
1631 | { | |
1632 | /* If we are unrolling, initialization is done in the original loop | |
1633 | body (number 0). */ | |
1634 | return n_copy; | |
1635 | } | |
1636 | else | |
1637 | { | |
1638 | /* If we are peeling, the copy in that the initialization occurs has | |
1639 | number 1. The original loop (number 0) is the last. */ | |
1640 | if (n_copy) | |
1641 | return n_copy - 1; | |
1642 | else | |
1643 | return n_copies; | |
1644 | } | |
1645 | } | |
1646 | ||
a9f6ecee | 1647 | /* Allocate basic variable for the induction variable chain. */ |
113d659a | 1648 | |
a9f6ecee AO |
1649 | static void |
1650 | allocate_basic_variable (struct iv_to_split *ivts) | |
113d659a | 1651 | { |
8cab83f0 | 1652 | rtx expr = SET_SRC (single_set (ivts->insn)); |
113d659a ZD |
1653 | |
1654 | ivts->base_var = gen_reg_rtx (GET_MODE (expr)); | |
113d659a ZD |
1655 | } |
1656 | ||
1657 | /* Insert initialization of basic variable of IVTS before INSN, taking | |
1658 | the initial value from INSN. */ | |
1659 | ||
1660 | static void | |
95ecfb26 | 1661 | insert_base_initialization (struct iv_to_split *ivts, rtx_insn *insn) |
113d659a | 1662 | { |
8cab83f0 | 1663 | rtx expr = copy_rtx (SET_SRC (single_set (insn))); |
95ecfb26 | 1664 | rtx_insn *seq; |
113d659a ZD |
1665 | |
1666 | start_sequence (); | |
1667 | expr = force_operand (expr, ivts->base_var); | |
1668 | if (expr != ivts->base_var) | |
1669 | emit_move_insn (ivts->base_var, expr); | |
1670 | seq = get_insns (); | |
1671 | end_sequence (); | |
1672 | ||
1673 | emit_insn_before (seq, insn); | |
1674 | } | |
1675 | ||
1676 | /* Replace the use of induction variable described in IVTS in INSN | |
1677 | by base variable + DELTA * step. */ | |
1678 | ||
1679 | static void | |
95ecfb26 | 1680 | split_iv (struct iv_to_split *ivts, rtx_insn *insn, unsigned delta) |
113d659a | 1681 | { |
95ecfb26 DM |
1682 | rtx expr, *loc, incr, var; |
1683 | rtx_insn *seq; | |
ef4bddc2 | 1684 | machine_mode mode = GET_MODE (ivts->base_var); |
113d659a ZD |
1685 | rtx src, dest, set; |
1686 | ||
1687 | /* Construct base + DELTA * step. */ | |
1688 | if (!delta) | |
1689 | expr = ivts->base_var; | |
1690 | else | |
1691 | { | |
1692 | incr = simplify_gen_binary (MULT, mode, | |
1693 | ivts->step, gen_int_mode (delta, mode)); | |
1694 | expr = simplify_gen_binary (PLUS, GET_MODE (ivts->base_var), | |
1695 | ivts->base_var, incr); | |
1696 | } | |
1697 | ||
1698 | /* Figure out where to do the replacement. */ | |
8cab83f0 | 1699 | loc = &SET_SRC (single_set (insn)); |
113d659a ZD |
1700 | |
1701 | /* If we can make the replacement right away, we're done. */ | |
1702 | if (validate_change (insn, loc, expr, 0)) | |
1703 | return; | |
1704 | ||
1705 | /* Otherwise, force EXPR into a register and try again. */ | |
1706 | start_sequence (); | |
1707 | var = gen_reg_rtx (mode); | |
1708 | expr = force_operand (expr, var); | |
1709 | if (expr != var) | |
1710 | emit_move_insn (var, expr); | |
1711 | seq = get_insns (); | |
1712 | end_sequence (); | |
1713 | emit_insn_before (seq, insn); | |
b8698a0f | 1714 | |
113d659a ZD |
1715 | if (validate_change (insn, loc, var, 0)) |
1716 | return; | |
1717 | ||
1718 | /* The last chance. Try recreating the assignment in insn | |
1719 | completely from scratch. */ | |
1720 | set = single_set (insn); | |
1721 | gcc_assert (set); | |
1722 | ||
1723 | start_sequence (); | |
1724 | *loc = var; | |
1725 | src = copy_rtx (SET_SRC (set)); | |
1726 | dest = copy_rtx (SET_DEST (set)); | |
1727 | src = force_operand (src, dest); | |
1728 | if (src != dest) | |
1729 | emit_move_insn (dest, src); | |
1730 | seq = get_insns (); | |
1731 | end_sequence (); | |
b8698a0f | 1732 | |
113d659a ZD |
1733 | emit_insn_before (seq, insn); |
1734 | delete_insn (insn); | |
1735 | } | |
1736 | ||
113d659a | 1737 | |
2cd0e9f4 | 1738 | /* Return one expansion of the accumulator recorded in struct VE. */ |
113d659a | 1739 | |
f37a4f14 RE |
1740 | static rtx |
1741 | get_expansion (struct var_to_expand *ve) | |
1742 | { | |
1743 | rtx reg; | |
b8698a0f | 1744 | |
f37a4f14 RE |
1745 | if (ve->reuse_expansion == 0) |
1746 | reg = ve->reg; | |
1747 | else | |
9771b263 | 1748 | reg = ve->var_expansions[ve->reuse_expansion - 1]; |
b8698a0f | 1749 | |
9771b263 | 1750 | if (ve->var_expansions.length () == (unsigned) ve->reuse_expansion) |
f37a4f14 | 1751 | ve->reuse_expansion = 0; |
b8698a0f | 1752 | else |
f37a4f14 | 1753 | ve->reuse_expansion++; |
b8698a0f | 1754 | |
f37a4f14 RE |
1755 | return reg; |
1756 | } | |
113d659a | 1757 | |
113d659a | 1758 | |
b8698a0f | 1759 | /* Given INSN replace the uses of the accumulator recorded in VE |
f37a4f14 RE |
1760 | with a new register. */ |
1761 | ||
1762 | static void | |
95ecfb26 | 1763 | expand_var_during_unrolling (struct var_to_expand *ve, rtx_insn *insn) |
f37a4f14 RE |
1764 | { |
1765 | rtx new_reg, set; | |
1766 | bool really_new_expansion = false; | |
b8698a0f | 1767 | |
f37a4f14 | 1768 | set = single_set (insn); |
b5e624c6 | 1769 | gcc_assert (set); |
b8698a0f | 1770 | |
f37a4f14 RE |
1771 | /* Generate a new register only if the expansion limit has not been |
1772 | reached. Else reuse an already existing expansion. */ | |
1773 | if (PARAM_VALUE (PARAM_MAX_VARIABLE_EXPANSIONS) > ve->expansion_count) | |
1774 | { | |
1775 | really_new_expansion = true; | |
1776 | new_reg = gen_reg_rtx (GET_MODE (ve->reg)); | |
1777 | } | |
1778 | else | |
1779 | new_reg = get_expansion (ve); | |
1780 | ||
6e74642b | 1781 | validate_replace_rtx_group (SET_DEST (set), new_reg, insn); |
f37a4f14 RE |
1782 | if (apply_change_group ()) |
1783 | if (really_new_expansion) | |
1784 | { | |
9771b263 | 1785 | ve->var_expansions.safe_push (new_reg); |
f37a4f14 RE |
1786 | ve->expansion_count++; |
1787 | } | |
1788 | } | |
1789 | ||
a9f6ecee AO |
1790 | /* Initialize the variable expansions in loop preheader. PLACE is the |
1791 | loop-preheader basic block where the initialization of the | |
1792 | expansions should take place. The expansions are initialized with | |
1793 | (-0) when the operation is plus or minus to honor sign zero. This | |
1794 | way we can prevent cases where the sign of the final result is | |
1795 | effected by the sign of the expansion. Here is an example to | |
1796 | demonstrate this: | |
b8698a0f | 1797 | |
290358f7 RE |
1798 | for (i = 0 ; i < n; i++) |
1799 | sum += something; | |
1800 | ||
1801 | ==> | |
1802 | ||
1803 | sum += something | |
1804 | .... | |
1805 | i = i+1; | |
1806 | sum1 += something | |
1807 | .... | |
1808 | i = i+1 | |
1809 | sum2 += something; | |
1810 | .... | |
b8698a0f | 1811 | |
290358f7 RE |
1812 | When SUM is initialized with -zero and SOMETHING is also -zero; the |
1813 | final result of sum should be -zero thus the expansions sum1 and sum2 | |
1814 | should be initialized with -zero as well (otherwise we will get +zero | |
1815 | as the final result). */ | |
f37a4f14 | 1816 | |
a9f6ecee AO |
1817 | static void |
1818 | insert_var_expansion_initialization (struct var_to_expand *ve, | |
1819 | basic_block place) | |
f37a4f14 | 1820 | { |
95ecfb26 DM |
1821 | rtx_insn *seq; |
1822 | rtx var, zero_init; | |
f37a4f14 | 1823 | unsigned i; |
ef4bddc2 | 1824 | machine_mode mode = GET_MODE (ve->reg); |
290358f7 RE |
1825 | bool honor_signed_zero_p = HONOR_SIGNED_ZEROS (mode); |
1826 | ||
9771b263 | 1827 | if (ve->var_expansions.length () == 0) |
a9f6ecee | 1828 | return; |
b8698a0f | 1829 | |
f37a4f14 | 1830 | start_sequence (); |
531e5376 RH |
1831 | switch (ve->op) |
1832 | { | |
1833 | case FMA: | |
1834 | /* Note that we only accumulate FMA via the ADD operand. */ | |
1835 | case PLUS: | |
1836 | case MINUS: | |
9771b263 | 1837 | FOR_EACH_VEC_ELT (ve->var_expansions, i, var) |
531e5376 RH |
1838 | { |
1839 | if (honor_signed_zero_p) | |
1840 | zero_init = simplify_gen_unary (NEG, mode, CONST0_RTX (mode), mode); | |
1841 | else | |
1842 | zero_init = CONST0_RTX (mode); | |
1843 | emit_move_insn (var, zero_init); | |
1844 | } | |
1845 | break; | |
1846 | ||
1847 | case MULT: | |
9771b263 | 1848 | FOR_EACH_VEC_ELT (ve->var_expansions, i, var) |
531e5376 RH |
1849 | { |
1850 | zero_init = CONST1_RTX (GET_MODE (var)); | |
1851 | emit_move_insn (var, zero_init); | |
1852 | } | |
1853 | break; | |
1854 | ||
1855 | default: | |
1856 | gcc_unreachable (); | |
1857 | } | |
b8698a0f | 1858 | |
f37a4f14 RE |
1859 | seq = get_insns (); |
1860 | end_sequence (); | |
b8698a0f | 1861 | |
6e74642b | 1862 | emit_insn_after (seq, BB_END (place)); |
f37a4f14 RE |
1863 | } |
1864 | ||
a9f6ecee AO |
1865 | /* Combine the variable expansions at the loop exit. PLACE is the |
1866 | loop exit basic block where the summation of the expansions should | |
1867 | take place. */ | |
f37a4f14 | 1868 | |
a9f6ecee AO |
1869 | static void |
1870 | combine_var_copies_in_loop_exit (struct var_to_expand *ve, basic_block place) | |
f37a4f14 | 1871 | { |
f37a4f14 | 1872 | rtx sum = ve->reg; |
95ecfb26 DM |
1873 | rtx expr, var; |
1874 | rtx_insn *seq, *insn; | |
f37a4f14 RE |
1875 | unsigned i; |
1876 | ||
9771b263 | 1877 | if (ve->var_expansions.length () == 0) |
a9f6ecee | 1878 | return; |
b8698a0f | 1879 | |
f37a4f14 | 1880 | start_sequence (); |
531e5376 RH |
1881 | switch (ve->op) |
1882 | { | |
1883 | case FMA: | |
1884 | /* Note that we only accumulate FMA via the ADD operand. */ | |
1885 | case PLUS: | |
1886 | case MINUS: | |
9771b263 | 1887 | FOR_EACH_VEC_ELT (ve->var_expansions, i, var) |
531e5376 RH |
1888 | sum = simplify_gen_binary (PLUS, GET_MODE (ve->reg), var, sum); |
1889 | break; | |
1890 | ||
1891 | case MULT: | |
9771b263 | 1892 | FOR_EACH_VEC_ELT (ve->var_expansions, i, var) |
531e5376 RH |
1893 | sum = simplify_gen_binary (MULT, GET_MODE (ve->reg), var, sum); |
1894 | break; | |
1895 | ||
1896 | default: | |
1897 | gcc_unreachable (); | |
1898 | } | |
b8698a0f | 1899 | |
f37a4f14 RE |
1900 | expr = force_operand (sum, ve->reg); |
1901 | if (expr != ve->reg) | |
1902 | emit_move_insn (ve->reg, expr); | |
1903 | seq = get_insns (); | |
1904 | end_sequence (); | |
b8698a0f | 1905 | |
f37a4f14 RE |
1906 | insn = BB_HEAD (place); |
1907 | while (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
1908 | insn = NEXT_INSN (insn); | |
1909 | ||
1910 | emit_insn_after (seq, insn); | |
f37a4f14 RE |
1911 | } |
1912 | ||
4a0c3fde SB |
1913 | /* Strip away REG_EQUAL notes for IVs we're splitting. |
1914 | ||
1915 | Updating REG_EQUAL notes for IVs we split is tricky: We | |
1916 | cannot tell until after unrolling, DF-rescanning, and liveness | |
1917 | updating, whether an EQ_USE is reached by the split IV while | |
1918 | the IV reg is still live. See PR55006. | |
1919 | ||
1920 | ??? We cannot use remove_reg_equal_equiv_notes_for_regno, | |
1921 | because RTL loop-iv requires us to defer rescanning insns and | |
1922 | any notes attached to them. So resort to old techniques... */ | |
1923 | ||
1924 | static void | |
95ecfb26 | 1925 | maybe_strip_eq_note_for_split_iv (struct opt_info *opt_info, rtx_insn *insn) |
4a0c3fde SB |
1926 | { |
1927 | struct iv_to_split *ivts; | |
1928 | rtx note = find_reg_equal_equiv_note (insn); | |
1929 | if (! note) | |
1930 | return; | |
1931 | for (ivts = opt_info->iv_to_split_head; ivts; ivts = ivts->next) | |
1932 | if (reg_mentioned_p (ivts->orig_var, note)) | |
1933 | { | |
1934 | remove_note (insn, note); | |
1935 | return; | |
1936 | } | |
1937 | } | |
1938 | ||
b8698a0f L |
1939 | /* Apply loop optimizations in loop copies using the |
1940 | data which gathered during the unrolling. Structure | |
f37a4f14 | 1941 | OPT_INFO record that data. |
b8698a0f | 1942 | |
113d659a ZD |
1943 | UNROLLING is true if we unrolled (not peeled) the loop. |
1944 | REWRITE_ORIGINAL_BODY is true if we should also rewrite the original body of | |
1945 | the loop (as it should happen in complete unrolling, but not in ordinary | |
1946 | peeling of the loop). */ | |
1947 | ||
1948 | static void | |
b8698a0f L |
1949 | apply_opt_in_copies (struct opt_info *opt_info, |
1950 | unsigned n_copies, bool unrolling, | |
f37a4f14 | 1951 | bool rewrite_original_loop) |
113d659a ZD |
1952 | { |
1953 | unsigned i, delta; | |
1954 | basic_block bb, orig_bb; | |
95ecfb26 | 1955 | rtx_insn *insn, *orig_insn, *next; |
113d659a | 1956 | struct iv_to_split ivts_templ, *ivts; |
f37a4f14 | 1957 | struct var_to_expand ve_templ, *ves; |
b8698a0f | 1958 | |
113d659a ZD |
1959 | /* Sanity check -- we need to put initialization in the original loop |
1960 | body. */ | |
1961 | gcc_assert (!unrolling || rewrite_original_loop); | |
b8698a0f | 1962 | |
113d659a | 1963 | /* Allocate the basic variables (i0). */ |
c203e8a7 | 1964 | if (opt_info->insns_to_split) |
a9f6ecee AO |
1965 | for (ivts = opt_info->iv_to_split_head; ivts; ivts = ivts->next) |
1966 | allocate_basic_variable (ivts); | |
b8698a0f | 1967 | |
8b1c6fd7 DM |
1968 | for (i = opt_info->first_new_block; |
1969 | i < (unsigned) last_basic_block_for_fn (cfun); | |
1970 | i++) | |
113d659a | 1971 | { |
06e28de2 | 1972 | bb = BASIC_BLOCK_FOR_FN (cfun, i); |
6580ee77 | 1973 | orig_bb = get_bb_original (bb); |
b8698a0f | 1974 | |
6580ee77 JH |
1975 | /* bb->aux holds position in copy sequence initialized by |
1976 | duplicate_loop_to_header_edge. */ | |
1977 | delta = determine_split_iv_delta ((size_t)bb->aux, n_copies, | |
113d659a | 1978 | unrolling); |
7f7b1718 | 1979 | bb->aux = 0; |
113d659a | 1980 | orig_insn = BB_HEAD (orig_bb); |
4a0c3fde | 1981 | FOR_BB_INSNS_SAFE (bb, insn, next) |
f37a4f14 | 1982 | { |
0397b965 JJ |
1983 | if (!INSN_P (insn) |
1984 | || (DEBUG_INSN_P (insn) | |
1985 | && TREE_CODE (INSN_VAR_LOCATION_DECL (insn)) == LABEL_DECL)) | |
f37a4f14 | 1986 | continue; |
b8698a0f | 1987 | |
0397b965 JJ |
1988 | while (!INSN_P (orig_insn) |
1989 | || (DEBUG_INSN_P (orig_insn) | |
1990 | && (TREE_CODE (INSN_VAR_LOCATION_DECL (orig_insn)) | |
1991 | == LABEL_DECL))) | |
f37a4f14 | 1992 | orig_insn = NEXT_INSN (orig_insn); |
b8698a0f | 1993 | |
f37a4f14 RE |
1994 | ivts_templ.insn = orig_insn; |
1995 | ve_templ.insn = orig_insn; | |
b8698a0f | 1996 | |
f37a4f14 | 1997 | /* Apply splitting iv optimization. */ |
c203e8a7 | 1998 | if (opt_info->insns_to_split) |
f37a4f14 | 1999 | { |
4a0c3fde SB |
2000 | maybe_strip_eq_note_for_split_iv (opt_info, insn); |
2001 | ||
c203e8a7 | 2002 | ivts = opt_info->insns_to_split->find (&ivts_templ); |
b8698a0f | 2003 | |
f37a4f14 RE |
2004 | if (ivts) |
2005 | { | |
21f868a2 ZD |
2006 | gcc_assert (GET_CODE (PATTERN (insn)) |
2007 | == GET_CODE (PATTERN (orig_insn))); | |
b8698a0f | 2008 | |
f37a4f14 RE |
2009 | if (!delta) |
2010 | insert_base_initialization (ivts, insn); | |
2011 | split_iv (ivts, insn, delta); | |
2012 | } | |
2013 | } | |
2014 | /* Apply variable expansion optimization. */ | |
c203e8a7 | 2015 | if (unrolling && opt_info->insns_with_var_to_expand) |
f37a4f14 | 2016 | { |
d3bfe4de | 2017 | ves = (struct var_to_expand *) |
c203e8a7 | 2018 | opt_info->insns_with_var_to_expand->find (&ve_templ); |
f37a4f14 | 2019 | if (ves) |
b8698a0f | 2020 | { |
21f868a2 ZD |
2021 | gcc_assert (GET_CODE (PATTERN (insn)) |
2022 | == GET_CODE (PATTERN (orig_insn))); | |
f37a4f14 RE |
2023 | expand_var_during_unrolling (ves, insn); |
2024 | } | |
2025 | } | |
2026 | orig_insn = NEXT_INSN (orig_insn); | |
2027 | } | |
113d659a ZD |
2028 | } |
2029 | ||
2030 | if (!rewrite_original_loop) | |
2031 | return; | |
b8698a0f | 2032 | |
f37a4f14 | 2033 | /* Initialize the variable expansions in the loop preheader |
b8698a0f | 2034 | and take care of combining them at the loop exit. */ |
c203e8a7 | 2035 | if (opt_info->insns_with_var_to_expand) |
f37a4f14 | 2036 | { |
a9f6ecee AO |
2037 | for (ves = opt_info->var_to_expand_head; ves; ves = ves->next) |
2038 | insert_var_expansion_initialization (ves, opt_info->loop_preheader); | |
2039 | for (ves = opt_info->var_to_expand_head; ves; ves = ves->next) | |
2040 | combine_var_copies_in_loop_exit (ves, opt_info->loop_exit); | |
f37a4f14 | 2041 | } |
b8698a0f | 2042 | |
113d659a ZD |
2043 | /* Rewrite also the original loop body. Find them as originals of the blocks |
2044 | in the last copied iteration, i.e. those that have | |
6580ee77 | 2045 | get_bb_copy (get_bb_original (bb)) == bb. */ |
8b1c6fd7 DM |
2046 | for (i = opt_info->first_new_block; |
2047 | i < (unsigned) last_basic_block_for_fn (cfun); | |
2048 | i++) | |
113d659a | 2049 | { |
06e28de2 | 2050 | bb = BASIC_BLOCK_FOR_FN (cfun, i); |
6580ee77 JH |
2051 | orig_bb = get_bb_original (bb); |
2052 | if (get_bb_copy (orig_bb) != bb) | |
113d659a | 2053 | continue; |
b8698a0f | 2054 | |
113d659a ZD |
2055 | delta = determine_split_iv_delta (0, n_copies, unrolling); |
2056 | for (orig_insn = BB_HEAD (orig_bb); | |
f37a4f14 RE |
2057 | orig_insn != NEXT_INSN (BB_END (bb)); |
2058 | orig_insn = next) | |
2059 | { | |
2060 | next = NEXT_INSN (orig_insn); | |
b8698a0f | 2061 | |
f37a4f14 RE |
2062 | if (!INSN_P (orig_insn)) |
2063 | continue; | |
b8698a0f | 2064 | |
f37a4f14 | 2065 | ivts_templ.insn = orig_insn; |
c203e8a7 | 2066 | if (opt_info->insns_to_split) |
f37a4f14 | 2067 | { |
4a0c3fde SB |
2068 | maybe_strip_eq_note_for_split_iv (opt_info, orig_insn); |
2069 | ||
d3bfe4de | 2070 | ivts = (struct iv_to_split *) |
c203e8a7 | 2071 | opt_info->insns_to_split->find (&ivts_templ); |
f37a4f14 RE |
2072 | if (ivts) |
2073 | { | |
2074 | if (!delta) | |
2075 | insert_base_initialization (ivts, orig_insn); | |
2076 | split_iv (ivts, orig_insn, delta); | |
2077 | continue; | |
2078 | } | |
2079 | } | |
b8698a0f | 2080 | |
f37a4f14 RE |
2081 | } |
2082 | } | |
2083 | } | |
113d659a | 2084 | |
f37a4f14 | 2085 | /* Release OPT_INFO. */ |
113d659a ZD |
2086 | |
2087 | static void | |
f37a4f14 | 2088 | free_opt_info (struct opt_info *opt_info) |
113d659a | 2089 | { |
c203e8a7 TS |
2090 | delete opt_info->insns_to_split; |
2091 | opt_info->insns_to_split = NULL; | |
2092 | if (opt_info->insns_with_var_to_expand) | |
f37a4f14 | 2093 | { |
a9f6ecee AO |
2094 | struct var_to_expand *ves; |
2095 | ||
2096 | for (ves = opt_info->var_to_expand_head; ves; ves = ves->next) | |
9771b263 | 2097 | ves->var_expansions.release (); |
c203e8a7 TS |
2098 | delete opt_info->insns_with_var_to_expand; |
2099 | opt_info->insns_with_var_to_expand = NULL; | |
f37a4f14 RE |
2100 | } |
2101 | free (opt_info); | |
113d659a | 2102 | } |