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ad4a85ad | 1 | /* Predictive commoning. |
fbd26352 | 2 | Copyright (C) 2005-2019 Free Software Foundation, Inc. |
48e1416a | 3 | |
ad4a85ad | 4 | This file is part of GCC. |
48e1416a | 5 | |
ad4a85ad | 6 | GCC is free software; you can redistribute it and/or modify it |
7 | under the terms of the GNU General Public License as published by the | |
8c4c00c1 | 8 | Free Software Foundation; either version 3, or (at your option) any |
ad4a85ad | 9 | later version. |
48e1416a | 10 | |
ad4a85ad | 11 | GCC is distributed in the hope that it will be useful, but WITHOUT |
12 | ANY 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. | |
48e1416a | 15 | |
ad4a85ad | 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/>. */ | |
ad4a85ad | 19 | |
20 | /* This file implements the predictive commoning optimization. Predictive | |
21 | commoning can be viewed as CSE around a loop, and with some improvements, | |
22 | as generalized strength reduction-- i.e., reusing values computed in | |
23 | earlier iterations of a loop in the later ones. So far, the pass only | |
24 | handles the most useful case, that is, reusing values of memory references. | |
25 | If you think this is all just a special case of PRE, you are sort of right; | |
26 | however, concentrating on loops is simpler, and makes it possible to | |
27 | incorporate data dependence analysis to detect the opportunities, perform | |
28 | loop unrolling to avoid copies together with renaming immediately, | |
29 | and if needed, we could also take register pressure into account. | |
30 | ||
31 | Let us demonstrate what is done on an example: | |
48e1416a | 32 | |
ad4a85ad | 33 | for (i = 0; i < 100; i++) |
34 | { | |
35 | a[i+2] = a[i] + a[i+1]; | |
36 | b[10] = b[10] + i; | |
37 | c[i] = c[99 - i]; | |
38 | d[i] = d[i + 1]; | |
39 | } | |
40 | ||
41 | 1) We find data references in the loop, and split them to mutually | |
42 | independent groups (i.e., we find components of a data dependence | |
43 | graph). We ignore read-read dependences whose distance is not constant. | |
44 | (TODO -- we could also ignore antidependences). In this example, we | |
45 | find the following groups: | |
46 | ||
47 | a[i]{read}, a[i+1]{read}, a[i+2]{write} | |
48 | b[10]{read}, b[10]{write} | |
49 | c[99 - i]{read}, c[i]{write} | |
50 | d[i + 1]{read}, d[i]{write} | |
51 | ||
52 | 2) Inside each of the group, we verify several conditions: | |
53 | a) all the references must differ in indices only, and the indices | |
54 | must all have the same step | |
55 | b) the references must dominate loop latch (and thus, they must be | |
56 | ordered by dominance relation). | |
57 | c) the distance of the indices must be a small multiple of the step | |
58 | We are then able to compute the difference of the references (# of | |
59 | iterations before they point to the same place as the first of them). | |
60 | Also, in case there are writes in the loop, we split the groups into | |
61 | chains whose head is the write whose values are used by the reads in | |
62 | the same chain. The chains are then processed independently, | |
63 | making the further transformations simpler. Also, the shorter chains | |
64 | need the same number of registers, but may require lower unrolling | |
65 | factor in order to get rid of the copies on the loop latch. | |
48e1416a | 66 | |
ad4a85ad | 67 | In our example, we get the following chains (the chain for c is invalid). |
68 | ||
69 | a[i]{read,+0}, a[i+1]{read,-1}, a[i+2]{write,-2} | |
70 | b[10]{read,+0}, b[10]{write,+0} | |
71 | d[i + 1]{read,+0}, d[i]{write,+1} | |
72 | ||
73 | 3) For each read, we determine the read or write whose value it reuses, | |
74 | together with the distance of this reuse. I.e. we take the last | |
75 | reference before it with distance 0, or the last of the references | |
76 | with the smallest positive distance to the read. Then, we remove | |
77 | the references that are not used in any of these chains, discard the | |
78 | empty groups, and propagate all the links so that they point to the | |
48e1416a | 79 | single root reference of the chain (adjusting their distance |
ad4a85ad | 80 | appropriately). Some extra care needs to be taken for references with |
81 | step 0. In our example (the numbers indicate the distance of the | |
82 | reuse), | |
83 | ||
84 | a[i] --> (*) 2, a[i+1] --> (*) 1, a[i+2] (*) | |
85 | b[10] --> (*) 1, b[10] (*) | |
86 | ||
87 | 4) The chains are combined together if possible. If the corresponding | |
88 | elements of two chains are always combined together with the same | |
89 | operator, we remember just the result of this combination, instead | |
90 | of remembering the values separately. We may need to perform | |
91 | reassociation to enable combining, for example | |
92 | ||
93 | e[i] + f[i+1] + e[i+1] + f[i] | |
94 | ||
95 | can be reassociated as | |
96 | ||
97 | (e[i] + f[i]) + (e[i+1] + f[i+1]) | |
98 | ||
99 | and we can combine the chains for e and f into one chain. | |
100 | ||
101 | 5) For each root reference (end of the chain) R, let N be maximum distance | |
9d75589a | 102 | of a reference reusing its value. Variables R0 up to RN are created, |
ad4a85ad | 103 | together with phi nodes that transfer values from R1 .. RN to |
104 | R0 .. R(N-1). | |
105 | Initial values are loaded to R0..R(N-1) (in case not all references | |
106 | must necessarily be accessed and they may trap, we may fail here; | |
107 | TODO sometimes, the loads could be guarded by a check for the number | |
108 | of iterations). Values loaded/stored in roots are also copied to | |
109 | RN. Other reads are replaced with the appropriate variable Ri. | |
110 | Everything is put to SSA form. | |
111 | ||
112 | As a small improvement, if R0 is dead after the root (i.e., all uses of | |
113 | the value with the maximum distance dominate the root), we can avoid | |
114 | creating RN and use R0 instead of it. | |
115 | ||
116 | In our example, we get (only the parts concerning a and b are shown): | |
117 | for (i = 0; i < 100; i++) | |
118 | { | |
119 | f = phi (a[0], s); | |
120 | s = phi (a[1], f); | |
121 | x = phi (b[10], x); | |
122 | ||
123 | f = f + s; | |
124 | a[i+2] = f; | |
125 | x = x + i; | |
126 | b[10] = x; | |
127 | } | |
128 | ||
129 | 6) Factor F for unrolling is determined as the smallest common multiple of | |
130 | (N + 1) for each root reference (N for references for that we avoided | |
131 | creating RN). If F and the loop is small enough, loop is unrolled F | |
132 | times. The stores to RN (R0) in the copies of the loop body are | |
133 | periodically replaced with R0, R1, ... (R1, R2, ...), so that they can | |
134 | be coalesced and the copies can be eliminated. | |
48e1416a | 135 | |
ad4a85ad | 136 | TODO -- copy propagation and other optimizations may change the live |
137 | ranges of the temporary registers and prevent them from being coalesced; | |
138 | this may increase the register pressure. | |
139 | ||
140 | In our case, F = 2 and the (main loop of the) result is | |
141 | ||
142 | for (i = 0; i < ...; i += 2) | |
143 | { | |
144 | f = phi (a[0], f); | |
145 | s = phi (a[1], s); | |
146 | x = phi (b[10], x); | |
147 | ||
148 | f = f + s; | |
149 | a[i+2] = f; | |
150 | x = x + i; | |
151 | b[10] = x; | |
152 | ||
153 | s = s + f; | |
154 | a[i+3] = s; | |
155 | x = x + i; | |
156 | b[10] = x; | |
157 | } | |
158 | ||
a652753d | 159 | Apart from predictive commoning on Load-Load and Store-Load chains, we |
160 | also support Store-Store chains -- stores killed by other store can be | |
161 | eliminated. Given below example: | |
162 | ||
163 | for (i = 0; i < n; i++) | |
164 | { | |
165 | a[i] = 1; | |
166 | a[i+2] = 2; | |
167 | } | |
ad4a85ad | 168 | |
a652753d | 169 | It can be replaced with: |
ad4a85ad | 170 | |
a652753d | 171 | t0 = a[0]; |
172 | t1 = a[1]; | |
173 | for (i = 0; i < n; i++) | |
174 | { | |
175 | a[i] = 1; | |
176 | t2 = 2; | |
177 | t0 = t1; | |
178 | t1 = t2; | |
179 | } | |
180 | a[n] = t0; | |
181 | a[n+1] = t1; | |
ad4a85ad | 182 | |
a652753d | 183 | If the loop runs more than 1 iterations, it can be further simplified into: |
184 | ||
185 | for (i = 0; i < n; i++) | |
186 | { | |
187 | a[i] = 1; | |
188 | } | |
189 | a[n] = 2; | |
190 | a[n+1] = 2; | |
191 | ||
192 | The interesting part is this can be viewed either as general store motion | |
193 | or general dead store elimination in either intra/inter-iterations way. | |
194 | ||
83c06cf0 | 195 | With trivial effort, we also support load inside Store-Store chains if the |
196 | load is dominated by a store statement in the same iteration of loop. You | |
197 | can see this as a restricted Store-Mixed-Load-Store chain. | |
198 | ||
a652753d | 199 | TODO: For now, we don't support store-store chains in multi-exit loops. We |
200 | force to not unroll in case of store-store chain even if other chains might | |
201 | ask for unroll. | |
ad4a85ad | 202 | |
203 | Predictive commoning can be generalized for arbitrary computations (not | |
204 | just memory loads), and also nontrivial transfer functions (e.g., replacing | |
205 | i * i with ii_last + 2 * i + 1), to generalize strength reduction. */ | |
206 | ||
207 | #include "config.h" | |
208 | #include "system.h" | |
209 | #include "coretypes.h" | |
9ef16211 | 210 | #include "backend.h" |
7c29e30e | 211 | #include "rtl.h" |
ad4a85ad | 212 | #include "tree.h" |
9ef16211 | 213 | #include "gimple.h" |
7c29e30e | 214 | #include "predict.h" |
215 | #include "tree-pass.h" | |
9ef16211 | 216 | #include "ssa.h" |
7c29e30e | 217 | #include "gimple-pretty-print.h" |
9ef16211 | 218 | #include "alias.h" |
b20a8bb4 | 219 | #include "fold-const.h" |
ad4a85ad | 220 | #include "cfgloop.h" |
bc61cadb | 221 | #include "tree-eh.h" |
a8783bee | 222 | #include "gimplify.h" |
dcf1a1ec | 223 | #include "gimple-iterator.h" |
e795d6e1 | 224 | #include "gimplify-me.h" |
05d9c18a | 225 | #include "tree-ssa-loop-ivopts.h" |
226 | #include "tree-ssa-loop-manip.h" | |
227 | #include "tree-ssa-loop-niter.h" | |
073c1fd5 | 228 | #include "tree-ssa-loop.h" |
229 | #include "tree-into-ssa.h" | |
230 | #include "tree-dfa.h" | |
69ee5dbb | 231 | #include "tree-ssa.h" |
ad4a85ad | 232 | #include "tree-data-ref.h" |
233 | #include "tree-scalar-evolution.h" | |
ad4a85ad | 234 | #include "params.h" |
ad4a85ad | 235 | #include "tree-affine.h" |
40395983 | 236 | #include "builtins.h" |
ad4a85ad | 237 | |
238 | /* The maximum number of iterations between the considered memory | |
239 | references. */ | |
240 | ||
241 | #define MAX_DISTANCE (target_avail_regs < 16 ? 4 : 8) | |
48e1416a | 242 | |
75a70cf9 | 243 | /* Data references (or phi nodes that carry data reference values across |
244 | loop iterations). */ | |
ad4a85ad | 245 | |
26dbec0a | 246 | typedef struct dref_d |
ad4a85ad | 247 | { |
248 | /* The reference itself. */ | |
249 | struct data_reference *ref; | |
250 | ||
251 | /* The statement in that the reference appears. */ | |
42acab1c | 252 | gimple *stmt; |
75a70cf9 | 253 | |
254 | /* In case that STMT is a phi node, this field is set to the SSA name | |
255 | defined by it in replace_phis_by_defined_names (in order to avoid | |
256 | pointing to phi node that got reallocated in the meantime). */ | |
257 | tree name_defined_by_phi; | |
ad4a85ad | 258 | |
259 | /* Distance of the reference from the root of the chain (in number of | |
260 | iterations of the loop). */ | |
261 | unsigned distance; | |
262 | ||
263 | /* Number of iterations offset from the first reference in the component. */ | |
5de9d3ed | 264 | widest_int offset; |
ad4a85ad | 265 | |
266 | /* Number of the reference in a component, in dominance ordering. */ | |
267 | unsigned pos; | |
268 | ||
269 | /* True if the memory reference is always accessed when the loop is | |
270 | entered. */ | |
271 | unsigned always_accessed : 1; | |
272 | } *dref; | |
273 | ||
ad4a85ad | 274 | |
275 | /* Type of the chain of the references. */ | |
276 | ||
277 | enum chain_type | |
278 | { | |
279 | /* The addresses of the references in the chain are constant. */ | |
280 | CT_INVARIANT, | |
281 | ||
282 | /* There are only loads in the chain. */ | |
283 | CT_LOAD, | |
284 | ||
285 | /* Root of the chain is store, the rest are loads. */ | |
286 | CT_STORE_LOAD, | |
287 | ||
a652753d | 288 | /* There are only stores in the chain. */ |
289 | CT_STORE_STORE, | |
290 | ||
ad4a85ad | 291 | /* A combination of two chains. */ |
292 | CT_COMBINATION | |
293 | }; | |
294 | ||
295 | /* Chains of data references. */ | |
296 | ||
297 | typedef struct chain | |
298 | { | |
299 | /* Type of the chain. */ | |
300 | enum chain_type type; | |
301 | ||
302 | /* For combination chains, the operator and the two chains that are | |
303 | combined, and the type of the result. */ | |
f4e36c33 | 304 | enum tree_code op; |
ad4a85ad | 305 | tree rslt_type; |
306 | struct chain *ch1, *ch2; | |
307 | ||
308 | /* The references in the chain. */ | |
f1f41a6c | 309 | vec<dref> refs; |
ad4a85ad | 310 | |
311 | /* The maximum distance of the reference in the chain from the root. */ | |
312 | unsigned length; | |
313 | ||
314 | /* The variables used to copy the value throughout iterations. */ | |
f1f41a6c | 315 | vec<tree> vars; |
ad4a85ad | 316 | |
317 | /* Initializers for the variables. */ | |
f1f41a6c | 318 | vec<tree> inits; |
ad4a85ad | 319 | |
a652753d | 320 | /* Finalizers for the eliminated stores. */ |
321 | vec<tree> finis; | |
322 | ||
a481acc5 | 323 | /* gimple stmts intializing the initial variables of the chain. */ |
324 | gimple_seq init_seq; | |
325 | ||
a652753d | 326 | /* gimple stmts finalizing the eliminated stores of the chain. */ |
327 | gimple_seq fini_seq; | |
328 | ||
ad4a85ad | 329 | /* True if there is a use of a variable with the maximal distance |
330 | that comes after the root in the loop. */ | |
331 | unsigned has_max_use_after : 1; | |
332 | ||
333 | /* True if all the memory references in the chain are always accessed. */ | |
334 | unsigned all_always_accessed : 1; | |
335 | ||
336 | /* True if this chain was combined together with some other chain. */ | |
337 | unsigned combined : 1; | |
e33b3a13 | 338 | |
339 | /* True if this is store elimination chain and eliminated stores store | |
340 | loop invariant value into memory. */ | |
341 | unsigned inv_store_elimination : 1; | |
ad4a85ad | 342 | } *chain_p; |
343 | ||
ad4a85ad | 344 | |
345 | /* Describes the knowledge about the step of the memory references in | |
346 | the component. */ | |
347 | ||
348 | enum ref_step_type | |
349 | { | |
350 | /* The step is zero. */ | |
351 | RS_INVARIANT, | |
352 | ||
353 | /* The step is nonzero. */ | |
354 | RS_NONZERO, | |
355 | ||
356 | /* The step may or may not be nonzero. */ | |
357 | RS_ANY | |
358 | }; | |
359 | ||
360 | /* Components of the data dependence graph. */ | |
361 | ||
362 | struct component | |
363 | { | |
364 | /* The references in the component. */ | |
f1f41a6c | 365 | vec<dref> refs; |
ad4a85ad | 366 | |
367 | /* What we know about the step of the references in the component. */ | |
368 | enum ref_step_type comp_step; | |
369 | ||
a652753d | 370 | /* True if all references in component are stores and we try to do |
371 | intra/inter loop iteration dead store elimination. */ | |
372 | bool eliminate_store_p; | |
373 | ||
ad4a85ad | 374 | /* Next component in the list. */ |
375 | struct component *next; | |
376 | }; | |
377 | ||
378 | /* Bitmap of ssa names defined by looparound phi nodes covered by chains. */ | |
379 | ||
380 | static bitmap looparound_phis; | |
381 | ||
382 | /* Cache used by tree_to_aff_combination_expand. */ | |
383 | ||
5f8841a5 | 384 | static hash_map<tree, name_expansion *> *name_expansions; |
ad4a85ad | 385 | |
386 | /* Dumps data reference REF to FILE. */ | |
387 | ||
388 | extern void dump_dref (FILE *, dref); | |
389 | void | |
390 | dump_dref (FILE *file, dref ref) | |
391 | { | |
392 | if (ref->ref) | |
393 | { | |
394 | fprintf (file, " "); | |
395 | print_generic_expr (file, DR_REF (ref->ref), TDF_SLIM); | |
396 | fprintf (file, " (id %u%s)\n", ref->pos, | |
397 | DR_IS_READ (ref->ref) ? "" : ", write"); | |
398 | ||
399 | fprintf (file, " offset "); | |
e913b5cd | 400 | print_decs (ref->offset, file); |
ad4a85ad | 401 | fprintf (file, "\n"); |
402 | ||
403 | fprintf (file, " distance %u\n", ref->distance); | |
404 | } | |
405 | else | |
406 | { | |
75a70cf9 | 407 | if (gimple_code (ref->stmt) == GIMPLE_PHI) |
ad4a85ad | 408 | fprintf (file, " looparound ref\n"); |
409 | else | |
410 | fprintf (file, " combination ref\n"); | |
411 | fprintf (file, " in statement "); | |
75a70cf9 | 412 | print_gimple_stmt (file, ref->stmt, 0, TDF_SLIM); |
ad4a85ad | 413 | fprintf (file, "\n"); |
414 | fprintf (file, " distance %u\n", ref->distance); | |
415 | } | |
416 | ||
417 | } | |
418 | ||
419 | /* Dumps CHAIN to FILE. */ | |
420 | ||
421 | extern void dump_chain (FILE *, chain_p); | |
422 | void | |
423 | dump_chain (FILE *file, chain_p chain) | |
424 | { | |
425 | dref a; | |
426 | const char *chain_type; | |
427 | unsigned i; | |
428 | tree var; | |
429 | ||
430 | switch (chain->type) | |
431 | { | |
432 | case CT_INVARIANT: | |
433 | chain_type = "Load motion"; | |
434 | break; | |
435 | ||
436 | case CT_LOAD: | |
437 | chain_type = "Loads-only"; | |
438 | break; | |
439 | ||
440 | case CT_STORE_LOAD: | |
441 | chain_type = "Store-loads"; | |
442 | break; | |
443 | ||
a652753d | 444 | case CT_STORE_STORE: |
445 | chain_type = "Store-stores"; | |
446 | break; | |
447 | ||
ad4a85ad | 448 | case CT_COMBINATION: |
449 | chain_type = "Combination"; | |
450 | break; | |
451 | ||
452 | default: | |
453 | gcc_unreachable (); | |
454 | } | |
455 | ||
456 | fprintf (file, "%s chain %p%s\n", chain_type, (void *) chain, | |
457 | chain->combined ? " (combined)" : ""); | |
458 | if (chain->type != CT_INVARIANT) | |
459 | fprintf (file, " max distance %u%s\n", chain->length, | |
460 | chain->has_max_use_after ? "" : ", may reuse first"); | |
461 | ||
462 | if (chain->type == CT_COMBINATION) | |
463 | { | |
464 | fprintf (file, " equal to %p %s %p in type ", | |
f4e36c33 | 465 | (void *) chain->ch1, op_symbol_code (chain->op), |
ad4a85ad | 466 | (void *) chain->ch2); |
467 | print_generic_expr (file, chain->rslt_type, TDF_SLIM); | |
468 | fprintf (file, "\n"); | |
469 | } | |
470 | ||
f1f41a6c | 471 | if (chain->vars.exists ()) |
ad4a85ad | 472 | { |
473 | fprintf (file, " vars"); | |
f1f41a6c | 474 | FOR_EACH_VEC_ELT (chain->vars, i, var) |
ad4a85ad | 475 | { |
476 | fprintf (file, " "); | |
477 | print_generic_expr (file, var, TDF_SLIM); | |
478 | } | |
479 | fprintf (file, "\n"); | |
480 | } | |
481 | ||
f1f41a6c | 482 | if (chain->inits.exists ()) |
ad4a85ad | 483 | { |
484 | fprintf (file, " inits"); | |
f1f41a6c | 485 | FOR_EACH_VEC_ELT (chain->inits, i, var) |
ad4a85ad | 486 | { |
487 | fprintf (file, " "); | |
488 | print_generic_expr (file, var, TDF_SLIM); | |
489 | } | |
490 | fprintf (file, "\n"); | |
491 | } | |
492 | ||
493 | fprintf (file, " references:\n"); | |
f1f41a6c | 494 | FOR_EACH_VEC_ELT (chain->refs, i, a) |
ad4a85ad | 495 | dump_dref (file, a); |
496 | ||
497 | fprintf (file, "\n"); | |
498 | } | |
499 | ||
500 | /* Dumps CHAINS to FILE. */ | |
501 | ||
f1f41a6c | 502 | extern void dump_chains (FILE *, vec<chain_p> ); |
ad4a85ad | 503 | void |
f1f41a6c | 504 | dump_chains (FILE *file, vec<chain_p> chains) |
ad4a85ad | 505 | { |
506 | chain_p chain; | |
507 | unsigned i; | |
508 | ||
f1f41a6c | 509 | FOR_EACH_VEC_ELT (chains, i, chain) |
ad4a85ad | 510 | dump_chain (file, chain); |
511 | } | |
512 | ||
513 | /* Dumps COMP to FILE. */ | |
514 | ||
515 | extern void dump_component (FILE *, struct component *); | |
516 | void | |
517 | dump_component (FILE *file, struct component *comp) | |
518 | { | |
519 | dref a; | |
520 | unsigned i; | |
521 | ||
522 | fprintf (file, "Component%s:\n", | |
523 | comp->comp_step == RS_INVARIANT ? " (invariant)" : ""); | |
f1f41a6c | 524 | FOR_EACH_VEC_ELT (comp->refs, i, a) |
ad4a85ad | 525 | dump_dref (file, a); |
526 | fprintf (file, "\n"); | |
527 | } | |
528 | ||
529 | /* Dumps COMPS to FILE. */ | |
530 | ||
531 | extern void dump_components (FILE *, struct component *); | |
532 | void | |
533 | dump_components (FILE *file, struct component *comps) | |
534 | { | |
535 | struct component *comp; | |
536 | ||
537 | for (comp = comps; comp; comp = comp->next) | |
538 | dump_component (file, comp); | |
539 | } | |
540 | ||
541 | /* Frees a chain CHAIN. */ | |
542 | ||
543 | static void | |
544 | release_chain (chain_p chain) | |
545 | { | |
546 | dref ref; | |
547 | unsigned i; | |
548 | ||
549 | if (chain == NULL) | |
550 | return; | |
551 | ||
f1f41a6c | 552 | FOR_EACH_VEC_ELT (chain->refs, i, ref) |
ad4a85ad | 553 | free (ref); |
554 | ||
f1f41a6c | 555 | chain->refs.release (); |
556 | chain->vars.release (); | |
557 | chain->inits.release (); | |
a481acc5 | 558 | if (chain->init_seq) |
559 | gimple_seq_discard (chain->init_seq); | |
ad4a85ad | 560 | |
a652753d | 561 | chain->finis.release (); |
562 | if (chain->fini_seq) | |
563 | gimple_seq_discard (chain->fini_seq); | |
564 | ||
ad4a85ad | 565 | free (chain); |
566 | } | |
567 | ||
568 | /* Frees CHAINS. */ | |
569 | ||
570 | static void | |
f1f41a6c | 571 | release_chains (vec<chain_p> chains) |
ad4a85ad | 572 | { |
573 | unsigned i; | |
574 | chain_p chain; | |
575 | ||
f1f41a6c | 576 | FOR_EACH_VEC_ELT (chains, i, chain) |
ad4a85ad | 577 | release_chain (chain); |
f1f41a6c | 578 | chains.release (); |
ad4a85ad | 579 | } |
580 | ||
581 | /* Frees a component COMP. */ | |
582 | ||
583 | static void | |
584 | release_component (struct component *comp) | |
585 | { | |
f1f41a6c | 586 | comp->refs.release (); |
ad4a85ad | 587 | free (comp); |
588 | } | |
589 | ||
590 | /* Frees list of components COMPS. */ | |
591 | ||
592 | static void | |
593 | release_components (struct component *comps) | |
594 | { | |
595 | struct component *act, *next; | |
596 | ||
597 | for (act = comps; act; act = next) | |
598 | { | |
599 | next = act->next; | |
600 | release_component (act); | |
601 | } | |
602 | } | |
603 | ||
604 | /* Finds a root of tree given by FATHERS containing A, and performs path | |
605 | shortening. */ | |
606 | ||
607 | static unsigned | |
608 | component_of (unsigned fathers[], unsigned a) | |
609 | { | |
610 | unsigned root, n; | |
611 | ||
612 | for (root = a; root != fathers[root]; root = fathers[root]) | |
613 | continue; | |
614 | ||
615 | for (; a != root; a = n) | |
616 | { | |
617 | n = fathers[a]; | |
618 | fathers[a] = root; | |
619 | } | |
620 | ||
621 | return root; | |
622 | } | |
623 | ||
624 | /* Join operation for DFU. FATHERS gives the tree, SIZES are sizes of the | |
625 | components, A and B are components to merge. */ | |
626 | ||
627 | static void | |
628 | merge_comps (unsigned fathers[], unsigned sizes[], unsigned a, unsigned b) | |
629 | { | |
630 | unsigned ca = component_of (fathers, a); | |
631 | unsigned cb = component_of (fathers, b); | |
632 | ||
633 | if (ca == cb) | |
634 | return; | |
635 | ||
636 | if (sizes[ca] < sizes[cb]) | |
637 | { | |
638 | sizes[cb] += sizes[ca]; | |
639 | fathers[ca] = cb; | |
640 | } | |
641 | else | |
642 | { | |
643 | sizes[ca] += sizes[cb]; | |
644 | fathers[cb] = ca; | |
645 | } | |
646 | } | |
647 | ||
648 | /* Returns true if A is a reference that is suitable for predictive commoning | |
649 | in the innermost loop that contains it. REF_STEP is set according to the | |
650 | step of the reference A. */ | |
651 | ||
652 | static bool | |
653 | suitable_reference_p (struct data_reference *a, enum ref_step_type *ref_step) | |
654 | { | |
655 | tree ref = DR_REF (a), step = DR_STEP (a); | |
656 | ||
657 | if (!step | |
450c0971 | 658 | || TREE_THIS_VOLATILE (ref) |
154edec0 | 659 | || !is_gimple_reg_type (TREE_TYPE (ref)) |
660 | || tree_could_throw_p (ref)) | |
ad4a85ad | 661 | return false; |
662 | ||
663 | if (integer_zerop (step)) | |
664 | *ref_step = RS_INVARIANT; | |
665 | else if (integer_nonzerop (step)) | |
666 | *ref_step = RS_NONZERO; | |
667 | else | |
668 | *ref_step = RS_ANY; | |
669 | ||
670 | return true; | |
671 | } | |
672 | ||
673 | /* Stores DR_OFFSET (DR) + DR_INIT (DR) to OFFSET. */ | |
674 | ||
675 | static void | |
676 | aff_combination_dr_offset (struct data_reference *dr, aff_tree *offset) | |
677 | { | |
a0553bff | 678 | tree type = TREE_TYPE (DR_OFFSET (dr)); |
ad4a85ad | 679 | aff_tree delta; |
680 | ||
a0553bff | 681 | tree_to_aff_combination_expand (DR_OFFSET (dr), type, offset, |
ad4a85ad | 682 | &name_expansions); |
c4d25d8a | 683 | aff_combination_const (&delta, type, wi::to_poly_widest (DR_INIT (dr))); |
ad4a85ad | 684 | aff_combination_add (offset, &delta); |
685 | } | |
686 | ||
687 | /* Determines number of iterations of the innermost enclosing loop before B | |
688 | refers to exactly the same location as A and stores it to OFF. If A and | |
689 | B do not have the same step, they never meet, or anything else fails, | |
690 | returns false, otherwise returns true. Both A and B are assumed to | |
691 | satisfy suitable_reference_p. */ | |
692 | ||
693 | static bool | |
694 | determine_offset (struct data_reference *a, struct data_reference *b, | |
1aeea61f | 695 | poly_widest_int *off) |
ad4a85ad | 696 | { |
697 | aff_tree diff, baseb, step; | |
ca4882a2 | 698 | tree typea, typeb; |
699 | ||
700 | /* Check that both the references access the location in the same type. */ | |
701 | typea = TREE_TYPE (DR_REF (a)); | |
702 | typeb = TREE_TYPE (DR_REF (b)); | |
548044d8 | 703 | if (!useless_type_conversion_p (typeb, typea)) |
ca4882a2 | 704 | return false; |
ad4a85ad | 705 | |
706 | /* Check whether the base address and the step of both references is the | |
707 | same. */ | |
708 | if (!operand_equal_p (DR_STEP (a), DR_STEP (b), 0) | |
709 | || !operand_equal_p (DR_BASE_ADDRESS (a), DR_BASE_ADDRESS (b), 0)) | |
710 | return false; | |
711 | ||
712 | if (integer_zerop (DR_STEP (a))) | |
713 | { | |
714 | /* If the references have loop invariant address, check that they access | |
715 | exactly the same location. */ | |
e913b5cd | 716 | *off = 0; |
ad4a85ad | 717 | return (operand_equal_p (DR_OFFSET (a), DR_OFFSET (b), 0) |
718 | && operand_equal_p (DR_INIT (a), DR_INIT (b), 0)); | |
719 | } | |
720 | ||
721 | /* Compare the offsets of the addresses, and check whether the difference | |
722 | is a multiple of step. */ | |
723 | aff_combination_dr_offset (a, &diff); | |
724 | aff_combination_dr_offset (b, &baseb); | |
e913b5cd | 725 | aff_combination_scale (&baseb, -1); |
ad4a85ad | 726 | aff_combination_add (&diff, &baseb); |
727 | ||
a0553bff | 728 | tree_to_aff_combination_expand (DR_STEP (a), TREE_TYPE (DR_STEP (a)), |
ad4a85ad | 729 | &step, &name_expansions); |
730 | return aff_combination_constant_multiple_p (&diff, &step, off); | |
731 | } | |
732 | ||
733 | /* Returns the last basic block in LOOP for that we are sure that | |
734 | it is executed whenever the loop is entered. */ | |
735 | ||
736 | static basic_block | |
737 | last_always_executed_block (struct loop *loop) | |
738 | { | |
739 | unsigned i; | |
f1f41a6c | 740 | vec<edge> exits = get_loop_exit_edges (loop); |
ad4a85ad | 741 | edge ex; |
742 | basic_block last = loop->latch; | |
743 | ||
f1f41a6c | 744 | FOR_EACH_VEC_ELT (exits, i, ex) |
ad4a85ad | 745 | last = nearest_common_dominator (CDI_DOMINATORS, last, ex->src); |
f1f41a6c | 746 | exits.release (); |
ad4a85ad | 747 | |
748 | return last; | |
749 | } | |
750 | ||
751 | /* Splits dependence graph on DATAREFS described by DEPENDS to components. */ | |
752 | ||
753 | static struct component * | |
754 | split_data_refs_to_components (struct loop *loop, | |
f1f41a6c | 755 | vec<data_reference_p> datarefs, |
756 | vec<ddr_p> depends) | |
ad4a85ad | 757 | { |
f1f41a6c | 758 | unsigned i, n = datarefs.length (); |
ad4a85ad | 759 | unsigned ca, ia, ib, bad; |
760 | unsigned *comp_father = XNEWVEC (unsigned, n + 1); | |
761 | unsigned *comp_size = XNEWVEC (unsigned, n + 1); | |
762 | struct component **comps; | |
763 | struct data_reference *dr, *dra, *drb; | |
764 | struct data_dependence_relation *ddr; | |
765 | struct component *comp_list = NULL, *comp; | |
766 | dref dataref; | |
a652753d | 767 | /* Don't do store elimination if loop has multiple exit edges. */ |
768 | bool eliminate_store_p = single_exit (loop) != NULL; | |
ad4a85ad | 769 | basic_block last_always_executed = last_always_executed_block (loop); |
48e1416a | 770 | |
f1f41a6c | 771 | FOR_EACH_VEC_ELT (datarefs, i, dr) |
ad4a85ad | 772 | { |
773 | if (!DR_REF (dr)) | |
774 | { | |
775 | /* A fake reference for call or asm_expr that may clobber memory; | |
776 | just fail. */ | |
777 | goto end; | |
778 | } | |
c71d3c24 | 779 | /* predcom pass isn't prepared to handle calls with data references. */ |
780 | if (is_gimple_call (DR_STMT (dr))) | |
781 | goto end; | |
5c205353 | 782 | dr->aux = (void *) (size_t) i; |
ad4a85ad | 783 | comp_father[i] = i; |
784 | comp_size[i] = 1; | |
785 | } | |
786 | ||
787 | /* A component reserved for the "bad" data references. */ | |
788 | comp_father[n] = n; | |
789 | comp_size[n] = 1; | |
790 | ||
f1f41a6c | 791 | FOR_EACH_VEC_ELT (datarefs, i, dr) |
ad4a85ad | 792 | { |
793 | enum ref_step_type dummy; | |
794 | ||
795 | if (!suitable_reference_p (dr, &dummy)) | |
796 | { | |
5c205353 | 797 | ia = (unsigned) (size_t) dr->aux; |
ad4a85ad | 798 | merge_comps (comp_father, comp_size, n, ia); |
799 | } | |
800 | } | |
801 | ||
f1f41a6c | 802 | FOR_EACH_VEC_ELT (depends, i, ddr) |
ad4a85ad | 803 | { |
1aeea61f | 804 | poly_widest_int dummy_off; |
ad4a85ad | 805 | |
806 | if (DDR_ARE_DEPENDENT (ddr) == chrec_known) | |
807 | continue; | |
808 | ||
809 | dra = DDR_A (ddr); | |
810 | drb = DDR_B (ddr); | |
a652753d | 811 | |
812 | /* Don't do store elimination if there is any unknown dependence for | |
813 | any store data reference. */ | |
814 | if ((DR_IS_WRITE (dra) || DR_IS_WRITE (drb)) | |
815 | && (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know | |
816 | || DDR_NUM_DIST_VECTS (ddr) == 0)) | |
817 | eliminate_store_p = false; | |
818 | ||
5c205353 | 819 | ia = component_of (comp_father, (unsigned) (size_t) dra->aux); |
820 | ib = component_of (comp_father, (unsigned) (size_t) drb->aux); | |
ad4a85ad | 821 | if (ia == ib) |
822 | continue; | |
823 | ||
824 | bad = component_of (comp_father, n); | |
825 | ||
826 | /* If both A and B are reads, we may ignore unsuitable dependences. */ | |
19f2ced2 | 827 | if (DR_IS_READ (dra) && DR_IS_READ (drb)) |
828 | { | |
829 | if (ia == bad || ib == bad | |
830 | || !determine_offset (dra, drb, &dummy_off)) | |
831 | continue; | |
832 | } | |
833 | /* If A is read and B write or vice versa and there is unsuitable | |
834 | dependence, instead of merging both components into a component | |
835 | that will certainly not pass suitable_component_p, just put the | |
836 | read into bad component, perhaps at least the write together with | |
837 | all the other data refs in it's component will be optimizable. */ | |
838 | else if (DR_IS_READ (dra) && ib != bad) | |
839 | { | |
840 | if (ia == bad) | |
841 | continue; | |
842 | else if (!determine_offset (dra, drb, &dummy_off)) | |
843 | { | |
844 | merge_comps (comp_father, comp_size, bad, ia); | |
845 | continue; | |
846 | } | |
847 | } | |
848 | else if (DR_IS_READ (drb) && ia != bad) | |
849 | { | |
850 | if (ib == bad) | |
851 | continue; | |
852 | else if (!determine_offset (dra, drb, &dummy_off)) | |
853 | { | |
854 | merge_comps (comp_father, comp_size, bad, ib); | |
855 | continue; | |
856 | } | |
857 | } | |
a652753d | 858 | else if (DR_IS_WRITE (dra) && DR_IS_WRITE (drb) |
859 | && ia != bad && ib != bad | |
860 | && !determine_offset (dra, drb, &dummy_off)) | |
861 | { | |
862 | merge_comps (comp_father, comp_size, bad, ia); | |
863 | merge_comps (comp_father, comp_size, bad, ib); | |
864 | continue; | |
865 | } | |
48e1416a | 866 | |
ad4a85ad | 867 | merge_comps (comp_father, comp_size, ia, ib); |
868 | } | |
869 | ||
a652753d | 870 | if (eliminate_store_p) |
871 | { | |
872 | tree niters = number_of_latch_executions (loop); | |
873 | ||
874 | /* Don't do store elimination if niters info is unknown because stores | |
875 | in the last iteration can't be eliminated and we need to recover it | |
876 | after loop. */ | |
877 | eliminate_store_p = (niters != NULL_TREE && niters != chrec_dont_know); | |
878 | } | |
879 | ||
ad4a85ad | 880 | comps = XCNEWVEC (struct component *, n); |
881 | bad = component_of (comp_father, n); | |
f1f41a6c | 882 | FOR_EACH_VEC_ELT (datarefs, i, dr) |
ad4a85ad | 883 | { |
5c205353 | 884 | ia = (unsigned) (size_t) dr->aux; |
ad4a85ad | 885 | ca = component_of (comp_father, ia); |
886 | if (ca == bad) | |
887 | continue; | |
888 | ||
889 | comp = comps[ca]; | |
890 | if (!comp) | |
891 | { | |
892 | comp = XCNEW (struct component); | |
f1f41a6c | 893 | comp->refs.create (comp_size[ca]); |
a652753d | 894 | comp->eliminate_store_p = eliminate_store_p; |
ad4a85ad | 895 | comps[ca] = comp; |
896 | } | |
897 | ||
26dbec0a | 898 | dataref = XCNEW (struct dref_d); |
ad4a85ad | 899 | dataref->ref = dr; |
900 | dataref->stmt = DR_STMT (dr); | |
e913b5cd | 901 | dataref->offset = 0; |
ad4a85ad | 902 | dataref->distance = 0; |
903 | ||
904 | dataref->always_accessed | |
905 | = dominated_by_p (CDI_DOMINATORS, last_always_executed, | |
75a70cf9 | 906 | gimple_bb (dataref->stmt)); |
f1f41a6c | 907 | dataref->pos = comp->refs.length (); |
908 | comp->refs.quick_push (dataref); | |
ad4a85ad | 909 | } |
910 | ||
911 | for (i = 0; i < n; i++) | |
912 | { | |
913 | comp = comps[i]; | |
914 | if (comp) | |
915 | { | |
916 | comp->next = comp_list; | |
917 | comp_list = comp; | |
918 | } | |
919 | } | |
920 | free (comps); | |
921 | ||
922 | end: | |
923 | free (comp_father); | |
924 | free (comp_size); | |
925 | return comp_list; | |
926 | } | |
927 | ||
928 | /* Returns true if the component COMP satisfies the conditions | |
310d2511 | 929 | described in 2) at the beginning of this file. LOOP is the current |
ad4a85ad | 930 | loop. */ |
48e1416a | 931 | |
ad4a85ad | 932 | static bool |
933 | suitable_component_p (struct loop *loop, struct component *comp) | |
934 | { | |
935 | unsigned i; | |
936 | dref a, first; | |
937 | basic_block ba, bp = loop->header; | |
938 | bool ok, has_write = false; | |
939 | ||
f1f41a6c | 940 | FOR_EACH_VEC_ELT (comp->refs, i, a) |
ad4a85ad | 941 | { |
75a70cf9 | 942 | ba = gimple_bb (a->stmt); |
ad4a85ad | 943 | |
944 | if (!just_once_each_iteration_p (loop, ba)) | |
945 | return false; | |
946 | ||
947 | gcc_assert (dominated_by_p (CDI_DOMINATORS, ba, bp)); | |
948 | bp = ba; | |
949 | ||
9ff25603 | 950 | if (DR_IS_WRITE (a->ref)) |
ad4a85ad | 951 | has_write = true; |
952 | } | |
953 | ||
f1f41a6c | 954 | first = comp->refs[0]; |
ad4a85ad | 955 | ok = suitable_reference_p (first->ref, &comp->comp_step); |
956 | gcc_assert (ok); | |
e913b5cd | 957 | first->offset = 0; |
ad4a85ad | 958 | |
f1f41a6c | 959 | for (i = 1; comp->refs.iterate (i, &a); i++) |
ad4a85ad | 960 | { |
1aeea61f | 961 | /* Polynomial offsets are no use, since we need to know the |
962 | gap between iteration numbers at compile time. */ | |
963 | poly_widest_int offset; | |
964 | if (!determine_offset (first->ref, a->ref, &offset) | |
965 | || !offset.is_constant (&a->offset)) | |
ad4a85ad | 966 | return false; |
967 | ||
382ecba7 | 968 | enum ref_step_type a_step; |
969 | gcc_checking_assert (suitable_reference_p (a->ref, &a_step) | |
970 | && a_step == comp->comp_step); | |
ad4a85ad | 971 | } |
972 | ||
973 | /* If there is a write inside the component, we must know whether the | |
974 | step is nonzero or not -- we would not otherwise be able to recognize | |
975 | whether the value accessed by reads comes from the OFFSET-th iteration | |
976 | or the previous one. */ | |
977 | if (has_write && comp->comp_step == RS_ANY) | |
978 | return false; | |
979 | ||
980 | return true; | |
981 | } | |
48e1416a | 982 | |
ad4a85ad | 983 | /* Check the conditions on references inside each of components COMPS, |
984 | and remove the unsuitable components from the list. The new list | |
985 | of components is returned. The conditions are described in 2) at | |
310d2511 | 986 | the beginning of this file. LOOP is the current loop. */ |
ad4a85ad | 987 | |
988 | static struct component * | |
989 | filter_suitable_components (struct loop *loop, struct component *comps) | |
990 | { | |
991 | struct component **comp, *act; | |
992 | ||
993 | for (comp = &comps; *comp; ) | |
994 | { | |
995 | act = *comp; | |
996 | if (suitable_component_p (loop, act)) | |
997 | comp = &act->next; | |
998 | else | |
999 | { | |
19af51e2 | 1000 | dref ref; |
1001 | unsigned i; | |
1002 | ||
ad4a85ad | 1003 | *comp = act->next; |
f1f41a6c | 1004 | FOR_EACH_VEC_ELT (act->refs, i, ref) |
19af51e2 | 1005 | free (ref); |
ad4a85ad | 1006 | release_component (act); |
1007 | } | |
1008 | } | |
1009 | ||
1010 | return comps; | |
1011 | } | |
1012 | ||
1013 | /* Compares two drefs A and B by their offset and position. Callback for | |
1014 | qsort. */ | |
1015 | ||
1016 | static int | |
1017 | order_drefs (const void *a, const void *b) | |
1018 | { | |
45ba1503 | 1019 | const dref *const da = (const dref *) a; |
1020 | const dref *const db = (const dref *) b; | |
796b6678 | 1021 | int offcmp = wi::cmps ((*da)->offset, (*db)->offset); |
ad4a85ad | 1022 | |
1023 | if (offcmp != 0) | |
1024 | return offcmp; | |
1025 | ||
1026 | return (*da)->pos - (*db)->pos; | |
1027 | } | |
1028 | ||
e02e28c4 | 1029 | /* Compares two drefs A and B by their position. Callback for qsort. */ |
1030 | ||
1031 | static int | |
1032 | order_drefs_by_pos (const void *a, const void *b) | |
1033 | { | |
1034 | const dref *const da = (const dref *) a; | |
1035 | const dref *const db = (const dref *) b; | |
1036 | ||
1037 | return (*da)->pos - (*db)->pos; | |
1038 | } | |
1039 | ||
ad4a85ad | 1040 | /* Returns root of the CHAIN. */ |
1041 | ||
1042 | static inline dref | |
1043 | get_chain_root (chain_p chain) | |
1044 | { | |
f1f41a6c | 1045 | return chain->refs[0]; |
ad4a85ad | 1046 | } |
1047 | ||
83c06cf0 | 1048 | /* Given CHAIN, returns the last write ref at DISTANCE, or NULL if it doesn't |
a652753d | 1049 | exist. */ |
1050 | ||
1051 | static inline dref | |
83c06cf0 | 1052 | get_chain_last_write_at (chain_p chain, unsigned distance) |
a652753d | 1053 | { |
83c06cf0 | 1054 | for (unsigned i = chain->refs.length (); i > 0; i--) |
1055 | if (DR_IS_WRITE (chain->refs[i - 1]->ref) | |
1056 | && distance == chain->refs[i - 1]->distance) | |
1057 | return chain->refs[i - 1]; | |
a652753d | 1058 | |
83c06cf0 | 1059 | return NULL; |
1060 | } | |
1061 | ||
1062 | /* Given CHAIN, returns the last write ref with the same distance before load | |
1063 | at index LOAD_IDX, or NULL if it doesn't exist. */ | |
1064 | ||
1065 | static inline dref | |
1066 | get_chain_last_write_before_load (chain_p chain, unsigned load_idx) | |
1067 | { | |
1068 | gcc_assert (load_idx < chain->refs.length ()); | |
1069 | ||
1070 | unsigned distance = chain->refs[load_idx]->distance; | |
a652753d | 1071 | |
83c06cf0 | 1072 | for (unsigned i = load_idx; i > 0; i--) |
1073 | if (DR_IS_WRITE (chain->refs[i - 1]->ref) | |
1074 | && distance == chain->refs[i - 1]->distance) | |
1075 | return chain->refs[i - 1]; | |
1076 | ||
1077 | return NULL; | |
a652753d | 1078 | } |
1079 | ||
ad4a85ad | 1080 | /* Adds REF to the chain CHAIN. */ |
1081 | ||
1082 | static void | |
1083 | add_ref_to_chain (chain_p chain, dref ref) | |
1084 | { | |
1085 | dref root = get_chain_root (chain); | |
ad4a85ad | 1086 | |
796b6678 | 1087 | gcc_assert (wi::les_p (root->offset, ref->offset)); |
ab2c1de8 | 1088 | widest_int dist = ref->offset - root->offset; |
796b6678 | 1089 | gcc_assert (wi::fits_uhwi_p (dist)); |
ad4a85ad | 1090 | |
f1f41a6c | 1091 | chain->refs.safe_push (ref); |
ad4a85ad | 1092 | |
cf8f0e63 | 1093 | ref->distance = dist.to_uhwi (); |
ad4a85ad | 1094 | |
1095 | if (ref->distance >= chain->length) | |
1096 | { | |
1097 | chain->length = ref->distance; | |
1098 | chain->has_max_use_after = false; | |
1099 | } | |
1100 | ||
83c06cf0 | 1101 | /* Promote this chain to CT_STORE_STORE if it has multiple stores. */ |
1102 | if (DR_IS_WRITE (ref->ref)) | |
1103 | chain->type = CT_STORE_STORE; | |
1104 | ||
c12979d1 | 1105 | /* Don't set the flag for store-store chain since there is no use. */ |
1106 | if (chain->type != CT_STORE_STORE | |
1107 | && ref->distance == chain->length | |
ad4a85ad | 1108 | && ref->pos > root->pos) |
1109 | chain->has_max_use_after = true; | |
1110 | ||
1111 | chain->all_always_accessed &= ref->always_accessed; | |
1112 | } | |
1113 | ||
1114 | /* Returns the chain for invariant component COMP. */ | |
1115 | ||
1116 | static chain_p | |
1117 | make_invariant_chain (struct component *comp) | |
1118 | { | |
1119 | chain_p chain = XCNEW (struct chain); | |
1120 | unsigned i; | |
1121 | dref ref; | |
1122 | ||
1123 | chain->type = CT_INVARIANT; | |
1124 | ||
1125 | chain->all_always_accessed = true; | |
1126 | ||
f1f41a6c | 1127 | FOR_EACH_VEC_ELT (comp->refs, i, ref) |
ad4a85ad | 1128 | { |
f1f41a6c | 1129 | chain->refs.safe_push (ref); |
ad4a85ad | 1130 | chain->all_always_accessed &= ref->always_accessed; |
1131 | } | |
1132 | ||
a652753d | 1133 | chain->inits = vNULL; |
1134 | chain->finis = vNULL; | |
1135 | ||
ad4a85ad | 1136 | return chain; |
1137 | } | |
1138 | ||
a652753d | 1139 | /* Make a new chain of type TYPE rooted at REF. */ |
ad4a85ad | 1140 | |
1141 | static chain_p | |
a652753d | 1142 | make_rooted_chain (dref ref, enum chain_type type) |
ad4a85ad | 1143 | { |
1144 | chain_p chain = XCNEW (struct chain); | |
1145 | ||
a652753d | 1146 | chain->type = type; |
f1f41a6c | 1147 | chain->refs.safe_push (ref); |
ad4a85ad | 1148 | chain->all_always_accessed = ref->always_accessed; |
ad4a85ad | 1149 | ref->distance = 0; |
1150 | ||
a652753d | 1151 | chain->inits = vNULL; |
1152 | chain->finis = vNULL; | |
1153 | ||
ad4a85ad | 1154 | return chain; |
1155 | } | |
1156 | ||
1157 | /* Returns true if CHAIN is not trivial. */ | |
1158 | ||
1159 | static bool | |
1160 | nontrivial_chain_p (chain_p chain) | |
1161 | { | |
f1f41a6c | 1162 | return chain != NULL && chain->refs.length () > 1; |
ad4a85ad | 1163 | } |
1164 | ||
1165 | /* Returns the ssa name that contains the value of REF, or NULL_TREE if there | |
1166 | is no such name. */ | |
1167 | ||
1168 | static tree | |
1169 | name_for_ref (dref ref) | |
1170 | { | |
1171 | tree name; | |
1172 | ||
75a70cf9 | 1173 | if (is_gimple_assign (ref->stmt)) |
ad4a85ad | 1174 | { |
1175 | if (!ref->ref || DR_IS_READ (ref->ref)) | |
75a70cf9 | 1176 | name = gimple_assign_lhs (ref->stmt); |
ad4a85ad | 1177 | else |
75a70cf9 | 1178 | name = gimple_assign_rhs1 (ref->stmt); |
ad4a85ad | 1179 | } |
1180 | else | |
1181 | name = PHI_RESULT (ref->stmt); | |
1182 | ||
1183 | return (TREE_CODE (name) == SSA_NAME ? name : NULL_TREE); | |
1184 | } | |
1185 | ||
1186 | /* Returns true if REF is a valid initializer for ROOT with given DISTANCE (in | |
1187 | iterations of the innermost enclosing loop). */ | |
1188 | ||
1189 | static bool | |
1190 | valid_initializer_p (struct data_reference *ref, | |
1191 | unsigned distance, struct data_reference *root) | |
1192 | { | |
1193 | aff_tree diff, base, step; | |
1aeea61f | 1194 | poly_widest_int off; |
ad4a85ad | 1195 | |
ad4a85ad | 1196 | /* Both REF and ROOT must be accessing the same object. */ |
1197 | if (!operand_equal_p (DR_BASE_ADDRESS (ref), DR_BASE_ADDRESS (root), 0)) | |
1198 | return false; | |
1199 | ||
1200 | /* The initializer is defined outside of loop, hence its address must be | |
1201 | invariant inside the loop. */ | |
1202 | gcc_assert (integer_zerop (DR_STEP (ref))); | |
1203 | ||
1204 | /* If the address of the reference is invariant, initializer must access | |
1205 | exactly the same location. */ | |
1206 | if (integer_zerop (DR_STEP (root))) | |
1207 | return (operand_equal_p (DR_OFFSET (ref), DR_OFFSET (root), 0) | |
1208 | && operand_equal_p (DR_INIT (ref), DR_INIT (root), 0)); | |
1209 | ||
1210 | /* Verify that this index of REF is equal to the root's index at | |
1211 | -DISTANCE-th iteration. */ | |
1212 | aff_combination_dr_offset (root, &diff); | |
1213 | aff_combination_dr_offset (ref, &base); | |
e913b5cd | 1214 | aff_combination_scale (&base, -1); |
ad4a85ad | 1215 | aff_combination_add (&diff, &base); |
1216 | ||
a0553bff | 1217 | tree_to_aff_combination_expand (DR_STEP (root), TREE_TYPE (DR_STEP (root)), |
1218 | &step, &name_expansions); | |
ad4a85ad | 1219 | if (!aff_combination_constant_multiple_p (&diff, &step, &off)) |
1220 | return false; | |
1221 | ||
1aeea61f | 1222 | if (maybe_ne (off, distance)) |
ad4a85ad | 1223 | return false; |
1224 | ||
1225 | return true; | |
1226 | } | |
1227 | ||
1228 | /* Finds looparound phi node of LOOP that copies the value of REF, and if its | |
1229 | initial value is correct (equal to initial value of REF shifted by one | |
1230 | iteration), returns the phi node. Otherwise, NULL_TREE is returned. ROOT | |
1231 | is the root of the current chain. */ | |
1232 | ||
1a91d914 | 1233 | static gphi * |
ad4a85ad | 1234 | find_looparound_phi (struct loop *loop, dref ref, dref root) |
1235 | { | |
75a70cf9 | 1236 | tree name, init, init_ref; |
1a91d914 | 1237 | gphi *phi = NULL; |
42acab1c | 1238 | gimple *init_stmt; |
ad4a85ad | 1239 | edge latch = loop_latch_edge (loop); |
1240 | struct data_reference init_dr; | |
1a91d914 | 1241 | gphi_iterator psi; |
ad4a85ad | 1242 | |
75a70cf9 | 1243 | if (is_gimple_assign (ref->stmt)) |
ad4a85ad | 1244 | { |
1245 | if (DR_IS_READ (ref->ref)) | |
75a70cf9 | 1246 | name = gimple_assign_lhs (ref->stmt); |
ad4a85ad | 1247 | else |
75a70cf9 | 1248 | name = gimple_assign_rhs1 (ref->stmt); |
ad4a85ad | 1249 | } |
1250 | else | |
1251 | name = PHI_RESULT (ref->stmt); | |
1252 | if (!name) | |
75a70cf9 | 1253 | return NULL; |
ad4a85ad | 1254 | |
75a70cf9 | 1255 | for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi)) |
1256 | { | |
1a91d914 | 1257 | phi = psi.phi (); |
75a70cf9 | 1258 | if (PHI_ARG_DEF_FROM_EDGE (phi, latch) == name) |
1259 | break; | |
1260 | } | |
ad4a85ad | 1261 | |
75a70cf9 | 1262 | if (gsi_end_p (psi)) |
1263 | return NULL; | |
ad4a85ad | 1264 | |
1265 | init = PHI_ARG_DEF_FROM_EDGE (phi, loop_preheader_edge (loop)); | |
1266 | if (TREE_CODE (init) != SSA_NAME) | |
75a70cf9 | 1267 | return NULL; |
ad4a85ad | 1268 | init_stmt = SSA_NAME_DEF_STMT (init); |
75a70cf9 | 1269 | if (gimple_code (init_stmt) != GIMPLE_ASSIGN) |
1270 | return NULL; | |
1271 | gcc_assert (gimple_assign_lhs (init_stmt) == init); | |
ad4a85ad | 1272 | |
75a70cf9 | 1273 | init_ref = gimple_assign_rhs1 (init_stmt); |
ad4a85ad | 1274 | if (!REFERENCE_CLASS_P (init_ref) |
1275 | && !DECL_P (init_ref)) | |
75a70cf9 | 1276 | return NULL; |
ad4a85ad | 1277 | |
1278 | /* Analyze the behavior of INIT_REF with respect to LOOP (innermost | |
1279 | loop enclosing PHI). */ | |
1280 | memset (&init_dr, 0, sizeof (struct data_reference)); | |
1281 | DR_REF (&init_dr) = init_ref; | |
1282 | DR_STMT (&init_dr) = phi; | |
ed9370cc | 1283 | if (!dr_analyze_innermost (&DR_INNERMOST (&init_dr), init_ref, loop, |
1284 | init_stmt)) | |
880734c8 | 1285 | return NULL; |
ad4a85ad | 1286 | |
1287 | if (!valid_initializer_p (&init_dr, ref->distance + 1, root->ref)) | |
75a70cf9 | 1288 | return NULL; |
ad4a85ad | 1289 | |
1290 | return phi; | |
1291 | } | |
1292 | ||
1293 | /* Adds a reference for the looparound copy of REF in PHI to CHAIN. */ | |
1294 | ||
1295 | static void | |
1a91d914 | 1296 | insert_looparound_copy (chain_p chain, dref ref, gphi *phi) |
ad4a85ad | 1297 | { |
26dbec0a | 1298 | dref nw = XCNEW (struct dref_d), aref; |
ad4a85ad | 1299 | unsigned i; |
1300 | ||
1301 | nw->stmt = phi; | |
1302 | nw->distance = ref->distance + 1; | |
1303 | nw->always_accessed = 1; | |
1304 | ||
f1f41a6c | 1305 | FOR_EACH_VEC_ELT (chain->refs, i, aref) |
ad4a85ad | 1306 | if (aref->distance >= nw->distance) |
1307 | break; | |
f1f41a6c | 1308 | chain->refs.safe_insert (i, nw); |
ad4a85ad | 1309 | |
1310 | if (nw->distance > chain->length) | |
1311 | { | |
1312 | chain->length = nw->distance; | |
1313 | chain->has_max_use_after = false; | |
1314 | } | |
1315 | } | |
1316 | ||
1317 | /* For references in CHAIN that are copied around the LOOP (created previously | |
1318 | by PRE, or by user), add the results of such copies to the chain. This | |
1319 | enables us to remove the copies by unrolling, and may need less registers | |
1320 | (also, it may allow us to combine chains together). */ | |
1321 | ||
1322 | static void | |
1323 | add_looparound_copies (struct loop *loop, chain_p chain) | |
1324 | { | |
1325 | unsigned i; | |
1326 | dref ref, root = get_chain_root (chain); | |
1a91d914 | 1327 | gphi *phi; |
ad4a85ad | 1328 | |
a652753d | 1329 | if (chain->type == CT_STORE_STORE) |
1330 | return; | |
1331 | ||
f1f41a6c | 1332 | FOR_EACH_VEC_ELT (chain->refs, i, ref) |
ad4a85ad | 1333 | { |
1334 | phi = find_looparound_phi (loop, ref, root); | |
1335 | if (!phi) | |
1336 | continue; | |
1337 | ||
1338 | bitmap_set_bit (looparound_phis, SSA_NAME_VERSION (PHI_RESULT (phi))); | |
1339 | insert_looparound_copy (chain, ref, phi); | |
1340 | } | |
1341 | } | |
1342 | ||
1343 | /* Find roots of the values and determine distances in the component COMP. | |
1344 | The references are redistributed into CHAINS. LOOP is the current | |
1345 | loop. */ | |
1346 | ||
1347 | static void | |
1348 | determine_roots_comp (struct loop *loop, | |
1349 | struct component *comp, | |
f1f41a6c | 1350 | vec<chain_p> *chains) |
ad4a85ad | 1351 | { |
1352 | unsigned i; | |
1353 | dref a; | |
1354 | chain_p chain = NULL; | |
5de9d3ed | 1355 | widest_int last_ofs = 0; |
a652753d | 1356 | enum chain_type type; |
ad4a85ad | 1357 | |
1358 | /* Invariants are handled specially. */ | |
1359 | if (comp->comp_step == RS_INVARIANT) | |
1360 | { | |
1361 | chain = make_invariant_chain (comp); | |
f1f41a6c | 1362 | chains->safe_push (chain); |
ad4a85ad | 1363 | return; |
1364 | } | |
1365 | ||
8a0e25c9 | 1366 | /* Trivial component. */ |
1367 | if (comp->refs.length () <= 1) | |
f7b2503a | 1368 | { |
1369 | if (comp->refs.length () == 1) | |
1370 | { | |
1371 | free (comp->refs[0]); | |
1372 | comp->refs.truncate (0); | |
1373 | } | |
1374 | return; | |
1375 | } | |
ad4a85ad | 1376 | |
8a0e25c9 | 1377 | comp->refs.qsort (order_drefs); |
83c06cf0 | 1378 | |
1379 | /* For Store-Store chain, we only support load if it is dominated by a | |
1380 | store statement in the same iteration of loop. */ | |
1381 | if (comp->eliminate_store_p) | |
1382 | for (a = NULL, i = 0; i < comp->refs.length (); i++) | |
1383 | { | |
1384 | if (DR_IS_WRITE (comp->refs[i]->ref)) | |
1385 | a = comp->refs[i]; | |
1386 | else if (a == NULL || a->offset != comp->refs[i]->offset) | |
1387 | { | |
1388 | /* If there is load that is not dominated by a store in the | |
1389 | same iteration of loop, clear the flag so no Store-Store | |
1390 | chain is generated for this component. */ | |
1391 | comp->eliminate_store_p = false; | |
1392 | break; | |
1393 | } | |
1394 | } | |
1395 | ||
1396 | /* Determine roots and create chains for components. */ | |
f1f41a6c | 1397 | FOR_EACH_VEC_ELT (comp->refs, i, a) |
ad4a85ad | 1398 | { |
a652753d | 1399 | if (!chain |
83c06cf0 | 1400 | || (chain->type == CT_LOAD && DR_IS_WRITE (a->ref)) |
a652753d | 1401 | || (!comp->eliminate_store_p && DR_IS_WRITE (a->ref)) |
796b6678 | 1402 | || wi::leu_p (MAX_DISTANCE, a->offset - last_ofs)) |
ad4a85ad | 1403 | { |
1404 | if (nontrivial_chain_p (chain)) | |
be2e5c02 | 1405 | { |
1406 | add_looparound_copies (loop, chain); | |
f1f41a6c | 1407 | chains->safe_push (chain); |
be2e5c02 | 1408 | } |
ad4a85ad | 1409 | else |
1410 | release_chain (chain); | |
a652753d | 1411 | |
83c06cf0 | 1412 | /* Determine type of the chain. If the root reference is a load, |
1413 | this can only be a CT_LOAD chain; other chains are intialized | |
1414 | to CT_STORE_LOAD and might be promoted to CT_STORE_STORE when | |
1415 | new reference is added. */ | |
1416 | type = DR_IS_READ (a->ref) ? CT_LOAD : CT_STORE_LOAD; | |
a652753d | 1417 | chain = make_rooted_chain (a, type); |
be2e5c02 | 1418 | last_ofs = a->offset; |
ad4a85ad | 1419 | continue; |
1420 | } | |
1421 | ||
1422 | add_ref_to_chain (chain, a); | |
1423 | } | |
1424 | ||
1425 | if (nontrivial_chain_p (chain)) | |
1426 | { | |
1427 | add_looparound_copies (loop, chain); | |
f1f41a6c | 1428 | chains->safe_push (chain); |
ad4a85ad | 1429 | } |
1430 | else | |
1431 | release_chain (chain); | |
1432 | } | |
1433 | ||
1434 | /* Find roots of the values and determine distances in components COMPS, and | |
1435 | separates the references to CHAINS. LOOP is the current loop. */ | |
1436 | ||
1437 | static void | |
1438 | determine_roots (struct loop *loop, | |
f1f41a6c | 1439 | struct component *comps, vec<chain_p> *chains) |
ad4a85ad | 1440 | { |
1441 | struct component *comp; | |
1442 | ||
1443 | for (comp = comps; comp; comp = comp->next) | |
1444 | determine_roots_comp (loop, comp, chains); | |
1445 | } | |
1446 | ||
1447 | /* Replace the reference in statement STMT with temporary variable | |
f4e36c33 | 1448 | NEW_TREE. If SET is true, NEW_TREE is instead initialized to the value of |
ad4a85ad | 1449 | the reference in the statement. IN_LHS is true if the reference |
1450 | is in the lhs of STMT, false if it is in rhs. */ | |
1451 | ||
1452 | static void | |
42acab1c | 1453 | replace_ref_with (gimple *stmt, tree new_tree, bool set, bool in_lhs) |
ad4a85ad | 1454 | { |
75a70cf9 | 1455 | tree val; |
1a91d914 | 1456 | gassign *new_stmt; |
75a70cf9 | 1457 | gimple_stmt_iterator bsi, psi; |
ad4a85ad | 1458 | |
75a70cf9 | 1459 | if (gimple_code (stmt) == GIMPLE_PHI) |
ad4a85ad | 1460 | { |
1461 | gcc_assert (!in_lhs && !set); | |
1462 | ||
1463 | val = PHI_RESULT (stmt); | |
75a70cf9 | 1464 | bsi = gsi_after_labels (gimple_bb (stmt)); |
1465 | psi = gsi_for_stmt (stmt); | |
1466 | remove_phi_node (&psi, false); | |
ad4a85ad | 1467 | |
75a70cf9 | 1468 | /* Turn the phi node into GIMPLE_ASSIGN. */ |
f4e36c33 | 1469 | new_stmt = gimple_build_assign (val, new_tree); |
75a70cf9 | 1470 | gsi_insert_before (&bsi, new_stmt, GSI_NEW_STMT); |
ad4a85ad | 1471 | return; |
1472 | } | |
48e1416a | 1473 | |
ad4a85ad | 1474 | /* Since the reference is of gimple_reg type, it should only |
1475 | appear as lhs or rhs of modify statement. */ | |
75a70cf9 | 1476 | gcc_assert (is_gimple_assign (stmt)); |
1477 | ||
1478 | bsi = gsi_for_stmt (stmt); | |
ad4a85ad | 1479 | |
f4e36c33 | 1480 | /* If we do not need to initialize NEW_TREE, just replace the use of OLD. */ |
ad4a85ad | 1481 | if (!set) |
1482 | { | |
1483 | gcc_assert (!in_lhs); | |
f4e36c33 | 1484 | gimple_assign_set_rhs_from_tree (&bsi, new_tree); |
75a70cf9 | 1485 | stmt = gsi_stmt (bsi); |
ad4a85ad | 1486 | update_stmt (stmt); |
1487 | return; | |
1488 | } | |
1489 | ||
ad4a85ad | 1490 | if (in_lhs) |
1491 | { | |
75a70cf9 | 1492 | /* We have statement |
48e1416a | 1493 | |
75a70cf9 | 1494 | OLD = VAL |
ad4a85ad | 1495 | |
75a70cf9 | 1496 | If OLD is a memory reference, then VAL is gimple_val, and we transform |
1497 | this to | |
ad4a85ad | 1498 | |
1499 | OLD = VAL | |
1500 | NEW = VAL | |
1501 | ||
48e1416a | 1502 | Otherwise, we are replacing a combination chain, |
75a70cf9 | 1503 | VAL is the expression that performs the combination, and OLD is an |
1504 | SSA name. In this case, we transform the assignment to | |
1505 | ||
1506 | OLD = VAL | |
1507 | NEW = OLD | |
1508 | ||
1509 | */ | |
1510 | ||
1511 | val = gimple_assign_lhs (stmt); | |
1512 | if (TREE_CODE (val) != SSA_NAME) | |
1513 | { | |
75a70cf9 | 1514 | val = gimple_assign_rhs1 (stmt); |
bbfbb5ba | 1515 | gcc_assert (gimple_assign_single_p (stmt)); |
1516 | if (TREE_CLOBBER_P (val)) | |
c6dfe037 | 1517 | val = get_or_create_ssa_default_def (cfun, SSA_NAME_VAR (new_tree)); |
bbfbb5ba | 1518 | else |
1519 | gcc_assert (gimple_assign_copy_p (stmt)); | |
75a70cf9 | 1520 | } |
ad4a85ad | 1521 | } |
1522 | else | |
1523 | { | |
ad4a85ad | 1524 | /* VAL = OLD |
1525 | ||
1526 | is transformed to | |
1527 | ||
1528 | VAL = OLD | |
1529 | NEW = VAL */ | |
75a70cf9 | 1530 | |
1531 | val = gimple_assign_lhs (stmt); | |
ad4a85ad | 1532 | } |
1533 | ||
f4e36c33 | 1534 | new_stmt = gimple_build_assign (new_tree, unshare_expr (val)); |
75a70cf9 | 1535 | gsi_insert_after (&bsi, new_stmt, GSI_NEW_STMT); |
ad4a85ad | 1536 | } |
1537 | ||
3e59c7a7 | 1538 | /* Returns a memory reference to DR in the (NITERS + ITER)-th iteration |
1539 | of the loop it was analyzed in. Append init stmts to STMTS. */ | |
99f6be4b | 1540 | |
b1abc234 | 1541 | static tree |
3e59c7a7 | 1542 | ref_at_iteration (data_reference_p dr, int iter, |
1543 | gimple_seq *stmts, tree niters = NULL_TREE) | |
99f6be4b | 1544 | { |
1545 | tree off = DR_OFFSET (dr); | |
1546 | tree coff = DR_INIT (dr); | |
b1abc234 | 1547 | tree ref = DR_REF (dr); |
1548 | enum tree_code ref_code = ERROR_MARK; | |
1549 | tree ref_type = NULL_TREE; | |
1550 | tree ref_op1 = NULL_TREE; | |
1551 | tree ref_op2 = NULL_TREE; | |
3e59c7a7 | 1552 | tree new_offset; |
1553 | ||
1554 | if (iter != 0) | |
1555 | { | |
1556 | new_offset = size_binop (MULT_EXPR, DR_STEP (dr), ssize_int (iter)); | |
1557 | if (TREE_CODE (new_offset) == INTEGER_CST) | |
1558 | coff = size_binop (PLUS_EXPR, coff, new_offset); | |
1559 | else | |
1560 | off = size_binop (PLUS_EXPR, off, new_offset); | |
1561 | } | |
1562 | ||
1563 | if (niters != NULL_TREE) | |
1564 | { | |
1565 | niters = fold_convert (ssizetype, niters); | |
1566 | new_offset = size_binop (MULT_EXPR, DR_STEP (dr), niters); | |
1567 | if (TREE_CODE (niters) == INTEGER_CST) | |
1568 | coff = size_binop (PLUS_EXPR, coff, new_offset); | |
1569 | else | |
1570 | off = size_binop (PLUS_EXPR, off, new_offset); | |
1571 | } | |
1572 | ||
e5104bca | 1573 | /* While data-ref analysis punts on bit offsets it still handles |
1574 | bitfield accesses at byte boundaries. Cope with that. Note that | |
b1abc234 | 1575 | if the bitfield object also starts at a byte-boundary we can simply |
1576 | replicate the COMPONENT_REF, but we have to subtract the component's | |
1577 | byte-offset from the MEM_REF address first. | |
1578 | Otherwise we simply build a BIT_FIELD_REF knowing that the bits | |
e5104bca | 1579 | start at offset zero. */ |
b1abc234 | 1580 | if (TREE_CODE (ref) == COMPONENT_REF |
1581 | && DECL_BIT_FIELD (TREE_OPERAND (ref, 1))) | |
e5104bca | 1582 | { |
b1abc234 | 1583 | unsigned HOST_WIDE_INT boff; |
1584 | tree field = TREE_OPERAND (ref, 1); | |
1585 | tree offset = component_ref_field_offset (ref); | |
1586 | ref_type = TREE_TYPE (ref); | |
1587 | boff = tree_to_uhwi (DECL_FIELD_BIT_OFFSET (field)); | |
1588 | /* This can occur in Ada. See the comment in get_bit_range. */ | |
1589 | if (boff % BITS_PER_UNIT != 0 | |
1590 | || !tree_fits_uhwi_p (offset)) | |
1591 | { | |
1592 | ref_code = BIT_FIELD_REF; | |
1593 | ref_op1 = DECL_SIZE (field); | |
1594 | ref_op2 = bitsize_zero_node; | |
1595 | } | |
1596 | else | |
1597 | { | |
1598 | boff >>= LOG2_BITS_PER_UNIT; | |
1599 | boff += tree_to_uhwi (offset); | |
1600 | coff = size_binop (MINUS_EXPR, coff, ssize_int (boff)); | |
1601 | ref_code = COMPONENT_REF; | |
1602 | ref_op1 = field; | |
1603 | ref_op2 = TREE_OPERAND (ref, 2); | |
1604 | ref = TREE_OPERAND (ref, 0); | |
1605 | } | |
ad4a85ad | 1606 | } |
b1abc234 | 1607 | tree addr = fold_build_pointer_plus (DR_BASE_ADDRESS (dr), off); |
1608 | addr = force_gimple_operand_1 (unshare_expr (addr), stmts, | |
1609 | is_gimple_mem_ref_addr, NULL_TREE); | |
1610 | tree alias_ptr = fold_convert (reference_alias_ptr_type (ref), coff); | |
1611 | tree type = build_aligned_type (TREE_TYPE (ref), | |
1612 | get_object_alignment (ref)); | |
1613 | ref = build2 (MEM_REF, type, addr, alias_ptr); | |
1614 | if (ref_type) | |
1615 | ref = build3 (ref_code, ref_type, ref, ref_op1, ref_op2); | |
1616 | return ref; | |
ad4a85ad | 1617 | } |
1618 | ||
1619 | /* Get the initialization expression for the INDEX-th temporary variable | |
1620 | of CHAIN. */ | |
1621 | ||
1622 | static tree | |
1623 | get_init_expr (chain_p chain, unsigned index) | |
1624 | { | |
1625 | if (chain->type == CT_COMBINATION) | |
1626 | { | |
1627 | tree e1 = get_init_expr (chain->ch1, index); | |
1628 | tree e2 = get_init_expr (chain->ch2, index); | |
1629 | ||
f4e36c33 | 1630 | return fold_build2 (chain->op, chain->rslt_type, e1, e2); |
ad4a85ad | 1631 | } |
1632 | else | |
f1f41a6c | 1633 | return chain->inits[index]; |
ad4a85ad | 1634 | } |
1635 | ||
a4c3242a | 1636 | /* Returns a new temporary variable used for the I-th variable carrying |
1637 | value of REF. The variable's uid is marked in TMP_VARS. */ | |
1638 | ||
1639 | static tree | |
1640 | predcom_tmp_var (tree ref, unsigned i, bitmap tmp_vars) | |
1641 | { | |
1642 | tree type = TREE_TYPE (ref); | |
a4c3242a | 1643 | /* We never access the components of the temporary variable in predictive |
1644 | commoning. */ | |
2ac51e48 | 1645 | tree var = create_tmp_reg (type, get_lsm_tmp_name (ref, i)); |
a4c3242a | 1646 | bitmap_set_bit (tmp_vars, DECL_UID (var)); |
1647 | return var; | |
1648 | } | |
1649 | ||
ad4a85ad | 1650 | /* Creates the variables for CHAIN, as well as phi nodes for them and |
1651 | initialization on entry to LOOP. Uids of the newly created | |
1652 | temporary variables are marked in TMP_VARS. */ | |
1653 | ||
1654 | static void | |
1655 | initialize_root_vars (struct loop *loop, chain_p chain, bitmap tmp_vars) | |
1656 | { | |
1657 | unsigned i; | |
1658 | unsigned n = chain->length; | |
1659 | dref root = get_chain_root (chain); | |
1660 | bool reuse_first = !chain->has_max_use_after; | |
75a70cf9 | 1661 | tree ref, init, var, next; |
1a91d914 | 1662 | gphi *phi; |
75a70cf9 | 1663 | gimple_seq stmts; |
ad4a85ad | 1664 | edge entry = loop_preheader_edge (loop), latch = loop_latch_edge (loop); |
1665 | ||
1666 | /* If N == 0, then all the references are within the single iteration. And | |
1667 | since this is an nonempty chain, reuse_first cannot be true. */ | |
1668 | gcc_assert (n > 0 || !reuse_first); | |
1669 | ||
f1f41a6c | 1670 | chain->vars.create (n + 1); |
ad4a85ad | 1671 | |
1672 | if (chain->type == CT_COMBINATION) | |
75a70cf9 | 1673 | ref = gimple_assign_lhs (root->stmt); |
ad4a85ad | 1674 | else |
1675 | ref = DR_REF (root->ref); | |
1676 | ||
1677 | for (i = 0; i < n + (reuse_first ? 0 : 1); i++) | |
1678 | { | |
a4c3242a | 1679 | var = predcom_tmp_var (ref, i, tmp_vars); |
f1f41a6c | 1680 | chain->vars.quick_push (var); |
ad4a85ad | 1681 | } |
1682 | if (reuse_first) | |
f1f41a6c | 1683 | chain->vars.quick_push (chain->vars[0]); |
48e1416a | 1684 | |
f1f41a6c | 1685 | FOR_EACH_VEC_ELT (chain->vars, i, var) |
f9e245b2 | 1686 | chain->vars[i] = make_ssa_name (var); |
ad4a85ad | 1687 | |
1688 | for (i = 0; i < n; i++) | |
1689 | { | |
f1f41a6c | 1690 | var = chain->vars[i]; |
1691 | next = chain->vars[i + 1]; | |
ad4a85ad | 1692 | init = get_init_expr (chain, i); |
1693 | ||
1694 | init = force_gimple_operand (init, &stmts, true, NULL_TREE); | |
1695 | if (stmts) | |
dd277d48 | 1696 | gsi_insert_seq_on_edge_immediate (entry, stmts); |
ad4a85ad | 1697 | |
1698 | phi = create_phi_node (var, loop->header); | |
60d535d2 | 1699 | add_phi_arg (phi, init, entry, UNKNOWN_LOCATION); |
1700 | add_phi_arg (phi, next, latch, UNKNOWN_LOCATION); | |
ad4a85ad | 1701 | } |
1702 | } | |
1703 | ||
e33b3a13 | 1704 | /* For inter-iteration store elimination CHAIN in LOOP, returns true if |
1705 | all stores to be eliminated store loop invariant values into memory. | |
1706 | In this case, we can use these invariant values directly after LOOP. */ | |
1707 | ||
1708 | static bool | |
1709 | is_inv_store_elimination_chain (struct loop *loop, chain_p chain) | |
1710 | { | |
1711 | if (chain->length == 0 || chain->type != CT_STORE_STORE) | |
1712 | return false; | |
1713 | ||
1714 | gcc_assert (!chain->has_max_use_after); | |
1715 | ||
1716 | /* If loop iterates for unknown times or fewer times than chain->lenght, | |
1717 | we still need to setup root variable and propagate it with PHI node. */ | |
1718 | tree niters = number_of_latch_executions (loop); | |
e3d0f65c | 1719 | if (TREE_CODE (niters) != INTEGER_CST |
1720 | || wi::leu_p (wi::to_wide (niters), chain->length)) | |
e33b3a13 | 1721 | return false; |
1722 | ||
1723 | /* Check stores in chain for elimination if they only store loop invariant | |
1724 | values. */ | |
1725 | for (unsigned i = 0; i < chain->length; i++) | |
1726 | { | |
83c06cf0 | 1727 | dref a = get_chain_last_write_at (chain, i); |
e33b3a13 | 1728 | if (a == NULL) |
1729 | continue; | |
1730 | ||
1731 | gimple *def_stmt, *stmt = a->stmt; | |
1732 | if (!gimple_assign_single_p (stmt)) | |
1733 | return false; | |
1734 | ||
1735 | tree val = gimple_assign_rhs1 (stmt); | |
1736 | if (TREE_CLOBBER_P (val)) | |
1737 | return false; | |
1738 | ||
1739 | if (CONSTANT_CLASS_P (val)) | |
1740 | continue; | |
1741 | ||
1742 | if (TREE_CODE (val) != SSA_NAME) | |
1743 | return false; | |
1744 | ||
1745 | def_stmt = SSA_NAME_DEF_STMT (val); | |
1746 | if (gimple_nop_p (def_stmt)) | |
1747 | continue; | |
1748 | ||
1749 | if (flow_bb_inside_loop_p (loop, gimple_bb (def_stmt))) | |
1750 | return false; | |
1751 | } | |
1752 | return true; | |
1753 | } | |
1754 | ||
1755 | /* Creates root variables for store elimination CHAIN in which stores for | |
1756 | elimination only store loop invariant values. In this case, we neither | |
1757 | need to load root variables before loop nor propagate it with PHI nodes. */ | |
1758 | ||
1759 | static void | |
1760 | initialize_root_vars_store_elim_1 (chain_p chain) | |
1761 | { | |
1762 | tree var; | |
1763 | unsigned i, n = chain->length; | |
1764 | ||
1765 | chain->vars.create (n); | |
1766 | chain->vars.safe_grow_cleared (n); | |
1767 | ||
1768 | /* Initialize root value for eliminated stores at each distance. */ | |
1769 | for (i = 0; i < n; i++) | |
1770 | { | |
83c06cf0 | 1771 | dref a = get_chain_last_write_at (chain, i); |
e33b3a13 | 1772 | if (a == NULL) |
1773 | continue; | |
1774 | ||
1775 | var = gimple_assign_rhs1 (a->stmt); | |
1776 | chain->vars[a->distance] = var; | |
1777 | } | |
1778 | ||
1779 | /* We don't propagate values with PHI nodes, so manually propagate value | |
1780 | to bubble positions. */ | |
1781 | var = chain->vars[0]; | |
1782 | for (i = 1; i < n; i++) | |
1783 | { | |
1784 | if (chain->vars[i] != NULL_TREE) | |
1785 | { | |
1786 | var = chain->vars[i]; | |
1787 | continue; | |
1788 | } | |
1789 | chain->vars[i] = var; | |
1790 | } | |
1791 | ||
1792 | /* Revert the vector. */ | |
1793 | for (i = 0; i < n / 2; i++) | |
1794 | std::swap (chain->vars[i], chain->vars[n - i - 1]); | |
1795 | } | |
1796 | ||
a652753d | 1797 | /* Creates root variables for store elimination CHAIN in which stores for |
1798 | elimination store loop variant values. In this case, we may need to | |
1799 | load root variables before LOOP and propagate it with PHI nodes. Uids | |
1800 | of the newly created root variables are marked in TMP_VARS. */ | |
1801 | ||
1802 | static void | |
1803 | initialize_root_vars_store_elim_2 (struct loop *loop, | |
1804 | chain_p chain, bitmap tmp_vars) | |
1805 | { | |
1806 | unsigned i, n = chain->length; | |
1807 | tree ref, init, var, next, val, phi_result; | |
1808 | gimple *stmt; | |
1809 | gimple_seq stmts; | |
1810 | ||
1811 | chain->vars.create (n); | |
1812 | ||
1813 | ref = DR_REF (get_chain_root (chain)->ref); | |
1814 | for (i = 0; i < n; i++) | |
1815 | { | |
1816 | var = predcom_tmp_var (ref, i, tmp_vars); | |
1817 | chain->vars.quick_push (var); | |
1818 | } | |
1819 | ||
1820 | FOR_EACH_VEC_ELT (chain->vars, i, var) | |
1821 | chain->vars[i] = make_ssa_name (var); | |
1822 | ||
1823 | /* Root values are either rhs operand of stores to be eliminated, or | |
1824 | loaded from memory before loop. */ | |
1825 | auto_vec<tree> vtemps; | |
1826 | vtemps.safe_grow_cleared (n); | |
1827 | for (i = 0; i < n; i++) | |
1828 | { | |
1829 | init = get_init_expr (chain, i); | |
1830 | if (init == NULL_TREE) | |
1831 | { | |
1832 | /* Root value is rhs operand of the store to be eliminated if | |
1833 | it isn't loaded from memory before loop. */ | |
83c06cf0 | 1834 | dref a = get_chain_last_write_at (chain, i); |
a652753d | 1835 | val = gimple_assign_rhs1 (a->stmt); |
1836 | if (TREE_CLOBBER_P (val)) | |
83c06cf0 | 1837 | { |
1838 | val = get_or_create_ssa_default_def (cfun, SSA_NAME_VAR (var)); | |
1839 | gimple_assign_set_rhs1 (a->stmt, val); | |
1840 | } | |
a652753d | 1841 | |
1842 | vtemps[n - i - 1] = val; | |
1843 | } | |
1844 | else | |
1845 | { | |
1846 | edge latch = loop_latch_edge (loop); | |
1847 | edge entry = loop_preheader_edge (loop); | |
1848 | ||
1849 | /* Root value is loaded from memory before loop, we also need | |
1850 | to add PHI nodes to propagate the value across iterations. */ | |
1851 | init = force_gimple_operand (init, &stmts, true, NULL_TREE); | |
1852 | if (stmts) | |
1853 | gsi_insert_seq_on_edge_immediate (entry, stmts); | |
1854 | ||
1855 | next = chain->vars[n - i]; | |
1856 | phi_result = copy_ssa_name (next); | |
1857 | gphi *phi = create_phi_node (phi_result, loop->header); | |
1858 | add_phi_arg (phi, init, entry, UNKNOWN_LOCATION); | |
1859 | add_phi_arg (phi, next, latch, UNKNOWN_LOCATION); | |
1860 | vtemps[n - i - 1] = phi_result; | |
1861 | } | |
1862 | } | |
1863 | ||
1864 | /* Find the insertion position. */ | |
1865 | dref last = get_chain_root (chain); | |
1866 | for (i = 0; i < chain->refs.length (); i++) | |
1867 | { | |
1868 | if (chain->refs[i]->pos > last->pos) | |
1869 | last = chain->refs[i]; | |
1870 | } | |
1871 | ||
1872 | gimple_stmt_iterator gsi = gsi_for_stmt (last->stmt); | |
1873 | ||
1874 | /* Insert statements copying root value to root variable. */ | |
1875 | for (i = 0; i < n; i++) | |
1876 | { | |
1877 | var = chain->vars[i]; | |
1878 | val = vtemps[i]; | |
1879 | stmt = gimple_build_assign (var, val); | |
1880 | gsi_insert_after (&gsi, stmt, GSI_NEW_STMT); | |
1881 | } | |
1882 | } | |
1883 | ||
1884 | /* Generates stores for CHAIN's eliminated stores in LOOP's last | |
1885 | (CHAIN->length - 1) iterations. */ | |
1886 | ||
1887 | static void | |
1888 | finalize_eliminated_stores (struct loop *loop, chain_p chain) | |
1889 | { | |
1890 | unsigned i, n = chain->length; | |
1891 | ||
1892 | for (i = 0; i < n; i++) | |
1893 | { | |
1894 | tree var = chain->vars[i]; | |
1895 | tree fini = chain->finis[n - i - 1]; | |
1896 | gimple *stmt = gimple_build_assign (fini, var); | |
1897 | ||
1898 | gimple_seq_add_stmt_without_update (&chain->fini_seq, stmt); | |
1899 | } | |
1900 | ||
1901 | if (chain->fini_seq) | |
1902 | { | |
1903 | gsi_insert_seq_on_edge_immediate (single_exit (loop), chain->fini_seq); | |
1904 | chain->fini_seq = NULL; | |
1905 | } | |
1906 | } | |
1907 | ||
ad4a85ad | 1908 | /* Initializes a variable for load motion for ROOT and prepares phi nodes and |
1909 | initialization on entry to LOOP if necessary. The ssa name for the variable | |
1910 | is stored in VARS. If WRITTEN is true, also a phi node to copy its value | |
1911 | around the loop is created. Uid of the newly created temporary variable | |
1912 | is marked in TMP_VARS. INITS is the list containing the (single) | |
1913 | initializer. */ | |
1914 | ||
1915 | static void | |
1916 | initialize_root_vars_lm (struct loop *loop, dref root, bool written, | |
f1f41a6c | 1917 | vec<tree> *vars, vec<tree> inits, |
ad4a85ad | 1918 | bitmap tmp_vars) |
1919 | { | |
1920 | unsigned i; | |
75a70cf9 | 1921 | tree ref = DR_REF (root->ref), init, var, next; |
1922 | gimple_seq stmts; | |
1a91d914 | 1923 | gphi *phi; |
ad4a85ad | 1924 | edge entry = loop_preheader_edge (loop), latch = loop_latch_edge (loop); |
1925 | ||
1926 | /* Find the initializer for the variable, and check that it cannot | |
1927 | trap. */ | |
f1f41a6c | 1928 | init = inits[0]; |
ad4a85ad | 1929 | |
f1f41a6c | 1930 | vars->create (written ? 2 : 1); |
a4c3242a | 1931 | var = predcom_tmp_var (ref, 0, tmp_vars); |
f1f41a6c | 1932 | vars->quick_push (var); |
ad4a85ad | 1933 | if (written) |
f1f41a6c | 1934 | vars->quick_push ((*vars)[0]); |
48e1416a | 1935 | |
f1f41a6c | 1936 | FOR_EACH_VEC_ELT (*vars, i, var) |
f9e245b2 | 1937 | (*vars)[i] = make_ssa_name (var); |
ad4a85ad | 1938 | |
f1f41a6c | 1939 | var = (*vars)[0]; |
48e1416a | 1940 | |
ad4a85ad | 1941 | init = force_gimple_operand (init, &stmts, written, NULL_TREE); |
1942 | if (stmts) | |
dd277d48 | 1943 | gsi_insert_seq_on_edge_immediate (entry, stmts); |
ad4a85ad | 1944 | |
1945 | if (written) | |
1946 | { | |
f1f41a6c | 1947 | next = (*vars)[1]; |
ad4a85ad | 1948 | phi = create_phi_node (var, loop->header); |
60d535d2 | 1949 | add_phi_arg (phi, init, entry, UNKNOWN_LOCATION); |
1950 | add_phi_arg (phi, next, latch, UNKNOWN_LOCATION); | |
ad4a85ad | 1951 | } |
1952 | else | |
1953 | { | |
1a91d914 | 1954 | gassign *init_stmt = gimple_build_assign (var, init); |
75a70cf9 | 1955 | gsi_insert_on_edge_immediate (entry, init_stmt); |
ad4a85ad | 1956 | } |
1957 | } | |
1958 | ||
1959 | ||
1960 | /* Execute load motion for references in chain CHAIN. Uids of the newly | |
1961 | created temporary variables are marked in TMP_VARS. */ | |
1962 | ||
1963 | static void | |
1964 | execute_load_motion (struct loop *loop, chain_p chain, bitmap tmp_vars) | |
1965 | { | |
c2078b80 | 1966 | auto_vec<tree> vars; |
ad4a85ad | 1967 | dref a; |
1968 | unsigned n_writes = 0, ridx, i; | |
1969 | tree var; | |
1970 | ||
1971 | gcc_assert (chain->type == CT_INVARIANT); | |
1972 | gcc_assert (!chain->combined); | |
f1f41a6c | 1973 | FOR_EACH_VEC_ELT (chain->refs, i, a) |
9ff25603 | 1974 | if (DR_IS_WRITE (a->ref)) |
ad4a85ad | 1975 | n_writes++; |
48e1416a | 1976 | |
ad4a85ad | 1977 | /* If there are no reads in the loop, there is nothing to do. */ |
f1f41a6c | 1978 | if (n_writes == chain->refs.length ()) |
ad4a85ad | 1979 | return; |
1980 | ||
1981 | initialize_root_vars_lm (loop, get_chain_root (chain), n_writes > 0, | |
1982 | &vars, chain->inits, tmp_vars); | |
1983 | ||
1984 | ridx = 0; | |
f1f41a6c | 1985 | FOR_EACH_VEC_ELT (chain->refs, i, a) |
ad4a85ad | 1986 | { |
1987 | bool is_read = DR_IS_READ (a->ref); | |
ad4a85ad | 1988 | |
9ff25603 | 1989 | if (DR_IS_WRITE (a->ref)) |
ad4a85ad | 1990 | { |
1991 | n_writes--; | |
1992 | if (n_writes) | |
1993 | { | |
f1f41a6c | 1994 | var = vars[0]; |
f9e245b2 | 1995 | var = make_ssa_name (SSA_NAME_VAR (var)); |
f1f41a6c | 1996 | vars[0] = var; |
ad4a85ad | 1997 | } |
1998 | else | |
1999 | ridx = 1; | |
2000 | } | |
48e1416a | 2001 | |
f1f41a6c | 2002 | replace_ref_with (a->stmt, vars[ridx], |
ad4a85ad | 2003 | !is_read, !is_read); |
2004 | } | |
ad4a85ad | 2005 | } |
2006 | ||
2007 | /* Returns the single statement in that NAME is used, excepting | |
2008 | the looparound phi nodes contained in one of the chains. If there is no | |
75a70cf9 | 2009 | such statement, or more statements, NULL is returned. */ |
ad4a85ad | 2010 | |
42acab1c | 2011 | static gimple * |
ad4a85ad | 2012 | single_nonlooparound_use (tree name) |
2013 | { | |
2014 | use_operand_p use; | |
2015 | imm_use_iterator it; | |
42acab1c | 2016 | gimple *stmt, *ret = NULL; |
ad4a85ad | 2017 | |
2018 | FOR_EACH_IMM_USE_FAST (use, it, name) | |
2019 | { | |
2020 | stmt = USE_STMT (use); | |
2021 | ||
75a70cf9 | 2022 | if (gimple_code (stmt) == GIMPLE_PHI) |
ad4a85ad | 2023 | { |
2024 | /* Ignore uses in looparound phi nodes. Uses in other phi nodes | |
2025 | could not be processed anyway, so just fail for them. */ | |
2026 | if (bitmap_bit_p (looparound_phis, | |
2027 | SSA_NAME_VERSION (PHI_RESULT (stmt)))) | |
2028 | continue; | |
2029 | ||
75a70cf9 | 2030 | return NULL; |
ad4a85ad | 2031 | } |
db16e52d | 2032 | else if (is_gimple_debug (stmt)) |
2033 | continue; | |
75a70cf9 | 2034 | else if (ret != NULL) |
2035 | return NULL; | |
ad4a85ad | 2036 | else |
2037 | ret = stmt; | |
2038 | } | |
2039 | ||
2040 | return ret; | |
2041 | } | |
2042 | ||
2043 | /* Remove statement STMT, as well as the chain of assignments in that it is | |
2044 | used. */ | |
2045 | ||
2046 | static void | |
42acab1c | 2047 | remove_stmt (gimple *stmt) |
ad4a85ad | 2048 | { |
75a70cf9 | 2049 | tree name; |
42acab1c | 2050 | gimple *next; |
75a70cf9 | 2051 | gimple_stmt_iterator psi; |
ad4a85ad | 2052 | |
75a70cf9 | 2053 | if (gimple_code (stmt) == GIMPLE_PHI) |
ad4a85ad | 2054 | { |
2055 | name = PHI_RESULT (stmt); | |
2056 | next = single_nonlooparound_use (name); | |
b6d5efe6 | 2057 | reset_debug_uses (stmt); |
75a70cf9 | 2058 | psi = gsi_for_stmt (stmt); |
2059 | remove_phi_node (&psi, true); | |
ad4a85ad | 2060 | |
2061 | if (!next | |
fb2d5860 | 2062 | || !gimple_assign_ssa_name_copy_p (next) |
75a70cf9 | 2063 | || gimple_assign_rhs1 (next) != name) |
ad4a85ad | 2064 | return; |
2065 | ||
2066 | stmt = next; | |
2067 | } | |
2068 | ||
2069 | while (1) | |
2070 | { | |
75a70cf9 | 2071 | gimple_stmt_iterator bsi; |
48e1416a | 2072 | |
75a70cf9 | 2073 | bsi = gsi_for_stmt (stmt); |
ad4a85ad | 2074 | |
75a70cf9 | 2075 | name = gimple_assign_lhs (stmt); |
a652753d | 2076 | if (TREE_CODE (name) == SSA_NAME) |
2077 | { | |
2078 | next = single_nonlooparound_use (name); | |
2079 | reset_debug_uses (stmt); | |
2080 | } | |
2081 | else | |
2082 | { | |
2083 | /* This is a store to be eliminated. */ | |
2084 | gcc_assert (gimple_vdef (stmt) != NULL); | |
2085 | next = NULL; | |
2086 | } | |
ad4a85ad | 2087 | |
e70e8b13 | 2088 | unlink_stmt_vdef (stmt); |
75a70cf9 | 2089 | gsi_remove (&bsi, true); |
fb2d5860 | 2090 | release_defs (stmt); |
ad4a85ad | 2091 | |
2092 | if (!next | |
fb2d5860 | 2093 | || !gimple_assign_ssa_name_copy_p (next) |
75a70cf9 | 2094 | || gimple_assign_rhs1 (next) != name) |
ad4a85ad | 2095 | return; |
2096 | ||
2097 | stmt = next; | |
2098 | } | |
2099 | } | |
2100 | ||
2101 | /* Perform the predictive commoning optimization for a chain CHAIN. | |
2102 | Uids of the newly created temporary variables are marked in TMP_VARS.*/ | |
2103 | ||
2104 | static void | |
2105 | execute_pred_commoning_chain (struct loop *loop, chain_p chain, | |
a652753d | 2106 | bitmap tmp_vars) |
ad4a85ad | 2107 | { |
83c06cf0 | 2108 | unsigned i; |
e70e8b13 | 2109 | dref a; |
ad4a85ad | 2110 | tree var; |
fbab3016 | 2111 | bool in_lhs; |
ad4a85ad | 2112 | |
2113 | if (chain->combined) | |
2114 | { | |
2115 | /* For combined chains, just remove the statements that are used to | |
182624fa | 2116 | compute the values of the expression (except for the root one). |
2117 | We delay this until after all chains are processed. */ | |
ad4a85ad | 2118 | } |
a652753d | 2119 | else if (chain->type == CT_STORE_STORE) |
2120 | { | |
2121 | if (chain->length > 0) | |
2122 | { | |
e33b3a13 | 2123 | if (chain->inv_store_elimination) |
2124 | { | |
2125 | /* If dead stores in this chain only store loop invariant | |
2126 | values, we can simply record the invariant value and use | |
2127 | it directly after loop. */ | |
2128 | initialize_root_vars_store_elim_1 (chain); | |
2129 | } | |
2130 | else | |
2131 | { | |
2132 | /* If dead stores in this chain store loop variant values, | |
2133 | we need to set up the variables by loading from memory | |
2134 | before loop and propagating it with PHI nodes. */ | |
2135 | initialize_root_vars_store_elim_2 (loop, chain, tmp_vars); | |
2136 | } | |
a652753d | 2137 | |
2138 | /* For inter-iteration store elimination chain, stores at each | |
2139 | distance in loop's last (chain->length - 1) iterations can't | |
2140 | be eliminated, because there is no following killing store. | |
2141 | We need to generate these stores after loop. */ | |
2142 | finalize_eliminated_stores (loop, chain); | |
2143 | } | |
2144 | ||
83c06cf0 | 2145 | bool last_store_p = true; |
2146 | for (i = chain->refs.length (); i > 0; i--) | |
2147 | { | |
2148 | a = chain->refs[i - 1]; | |
2149 | /* Preserve the last store of the chain. Eliminate other stores | |
2150 | which are killed by the last one. */ | |
2151 | if (DR_IS_WRITE (a->ref)) | |
2152 | { | |
2153 | if (last_store_p) | |
2154 | last_store_p = false; | |
2155 | else | |
2156 | remove_stmt (a->stmt); | |
2157 | ||
2158 | continue; | |
2159 | } | |
2160 | ||
2161 | /* Any load in Store-Store chain must be dominated by a previous | |
2162 | store, we replace the load reference with rhs of the store. */ | |
2163 | dref b = get_chain_last_write_before_load (chain, i - 1); | |
2164 | gcc_assert (b != NULL); | |
2165 | var = gimple_assign_rhs1 (b->stmt); | |
2166 | replace_ref_with (a->stmt, var, false, false); | |
2167 | } | |
a652753d | 2168 | } |
ad4a85ad | 2169 | else |
2170 | { | |
fbab3016 | 2171 | /* For non-combined chains, set up the variables that hold its value. */ |
2172 | initialize_root_vars (loop, chain, tmp_vars); | |
2173 | a = get_chain_root (chain); | |
2174 | in_lhs = (chain->type == CT_STORE_LOAD | |
2175 | || chain->type == CT_COMBINATION); | |
2176 | replace_ref_with (a->stmt, chain->vars[chain->length], true, in_lhs); | |
2177 | ||
2178 | /* Replace the uses of the original references by these variables. */ | |
f1f41a6c | 2179 | for (i = 1; chain->refs.iterate (i, &a); i++) |
ad4a85ad | 2180 | { |
f1f41a6c | 2181 | var = chain->vars[chain->length - a->distance]; |
ad4a85ad | 2182 | replace_ref_with (a->stmt, var, false, false); |
2183 | } | |
2184 | } | |
2185 | } | |
2186 | ||
2187 | /* Determines the unroll factor necessary to remove as many temporary variable | |
2188 | copies as possible. CHAINS is the list of chains that will be | |
2189 | optimized. */ | |
2190 | ||
2191 | static unsigned | |
f1f41a6c | 2192 | determine_unroll_factor (vec<chain_p> chains) |
ad4a85ad | 2193 | { |
2194 | chain_p chain; | |
2195 | unsigned factor = 1, af, nfactor, i; | |
2196 | unsigned max = PARAM_VALUE (PARAM_MAX_UNROLL_TIMES); | |
2197 | ||
f1f41a6c | 2198 | FOR_EACH_VEC_ELT (chains, i, chain) |
ad4a85ad | 2199 | { |
67a97bd8 | 2200 | if (chain->type == CT_INVARIANT) |
ad4a85ad | 2201 | continue; |
a652753d | 2202 | /* For now we can't handle unrolling when eliminating stores. */ |
2203 | else if (chain->type == CT_STORE_STORE) | |
2204 | return 1; | |
ad4a85ad | 2205 | |
67a97bd8 | 2206 | if (chain->combined) |
2207 | { | |
2208 | /* For combined chains, we can't handle unrolling if we replace | |
2209 | looparound PHIs. */ | |
2210 | dref a; | |
2211 | unsigned j; | |
2212 | for (j = 1; chain->refs.iterate (j, &a); j++) | |
2213 | if (gimple_code (a->stmt) == GIMPLE_PHI) | |
2214 | return 1; | |
2215 | continue; | |
2216 | } | |
2217 | ||
ad4a85ad | 2218 | /* The best unroll factor for this chain is equal to the number of |
2219 | temporary variables that we create for it. */ | |
2220 | af = chain->length; | |
2221 | if (chain->has_max_use_after) | |
2222 | af++; | |
2223 | ||
2224 | nfactor = factor * af / gcd (factor, af); | |
2225 | if (nfactor <= max) | |
2226 | factor = nfactor; | |
2227 | } | |
2228 | ||
2229 | return factor; | |
2230 | } | |
2231 | ||
2232 | /* Perform the predictive commoning optimization for CHAINS. | |
2233 | Uids of the newly created temporary variables are marked in TMP_VARS. */ | |
2234 | ||
2235 | static void | |
f1f41a6c | 2236 | execute_pred_commoning (struct loop *loop, vec<chain_p> chains, |
ad4a85ad | 2237 | bitmap tmp_vars) |
2238 | { | |
2239 | chain_p chain; | |
2240 | unsigned i; | |
2241 | ||
f1f41a6c | 2242 | FOR_EACH_VEC_ELT (chains, i, chain) |
ad4a85ad | 2243 | { |
2244 | if (chain->type == CT_INVARIANT) | |
2245 | execute_load_motion (loop, chain, tmp_vars); | |
2246 | else | |
2247 | execute_pred_commoning_chain (loop, chain, tmp_vars); | |
2248 | } | |
48e1416a | 2249 | |
182624fa | 2250 | FOR_EACH_VEC_ELT (chains, i, chain) |
2251 | { | |
2252 | if (chain->type == CT_INVARIANT) | |
2253 | ; | |
2254 | else if (chain->combined) | |
2255 | { | |
2256 | /* For combined chains, just remove the statements that are used to | |
2257 | compute the values of the expression (except for the root one). */ | |
2258 | dref a; | |
2259 | unsigned j; | |
2260 | for (j = 1; chain->refs.iterate (j, &a); j++) | |
2261 | remove_stmt (a->stmt); | |
2262 | } | |
2263 | } | |
2264 | ||
ad4a85ad | 2265 | update_ssa (TODO_update_ssa_only_virtuals); |
2266 | } | |
2267 | ||
310d2511 | 2268 | /* For each reference in CHAINS, if its defining statement is |
75a70cf9 | 2269 | phi node, record the ssa name that is defined by it. */ |
ad4a85ad | 2270 | |
2271 | static void | |
f1f41a6c | 2272 | replace_phis_by_defined_names (vec<chain_p> chains) |
ad4a85ad | 2273 | { |
2274 | chain_p chain; | |
2275 | dref a; | |
2276 | unsigned i, j; | |
2277 | ||
f1f41a6c | 2278 | FOR_EACH_VEC_ELT (chains, i, chain) |
2279 | FOR_EACH_VEC_ELT (chain->refs, j, a) | |
ad4a85ad | 2280 | { |
75a70cf9 | 2281 | if (gimple_code (a->stmt) == GIMPLE_PHI) |
2282 | { | |
2283 | a->name_defined_by_phi = PHI_RESULT (a->stmt); | |
2284 | a->stmt = NULL; | |
2285 | } | |
ad4a85ad | 2286 | } |
2287 | } | |
2288 | ||
75a70cf9 | 2289 | /* For each reference in CHAINS, if name_defined_by_phi is not |
2290 | NULL, use it to set the stmt field. */ | |
ad4a85ad | 2291 | |
2292 | static void | |
f1f41a6c | 2293 | replace_names_by_phis (vec<chain_p> chains) |
ad4a85ad | 2294 | { |
2295 | chain_p chain; | |
2296 | dref a; | |
2297 | unsigned i, j; | |
2298 | ||
f1f41a6c | 2299 | FOR_EACH_VEC_ELT (chains, i, chain) |
2300 | FOR_EACH_VEC_ELT (chain->refs, j, a) | |
75a70cf9 | 2301 | if (a->stmt == NULL) |
ad4a85ad | 2302 | { |
75a70cf9 | 2303 | a->stmt = SSA_NAME_DEF_STMT (a->name_defined_by_phi); |
2304 | gcc_assert (gimple_code (a->stmt) == GIMPLE_PHI); | |
2305 | a->name_defined_by_phi = NULL_TREE; | |
ad4a85ad | 2306 | } |
2307 | } | |
2308 | ||
2309 | /* Wrapper over execute_pred_commoning, to pass it as a callback | |
2310 | to tree_transform_and_unroll_loop. */ | |
2311 | ||
2312 | struct epcc_data | |
2313 | { | |
f1f41a6c | 2314 | vec<chain_p> chains; |
ad4a85ad | 2315 | bitmap tmp_vars; |
2316 | }; | |
2317 | ||
2318 | static void | |
2319 | execute_pred_commoning_cbck (struct loop *loop, void *data) | |
2320 | { | |
45ba1503 | 2321 | struct epcc_data *const dta = (struct epcc_data *) data; |
ad4a85ad | 2322 | |
2323 | /* Restore phi nodes that were replaced by ssa names before | |
2324 | tree_transform_and_unroll_loop (see detailed description in | |
2325 | tree_predictive_commoning_loop). */ | |
2326 | replace_names_by_phis (dta->chains); | |
2327 | execute_pred_commoning (loop, dta->chains, dta->tmp_vars); | |
2328 | } | |
2329 | ||
ad4a85ad | 2330 | /* Base NAME and all the names in the chain of phi nodes that use it |
2331 | on variable VAR. The phi nodes are recognized by being in the copies of | |
2332 | the header of the LOOP. */ | |
2333 | ||
2334 | static void | |
2335 | base_names_in_chain_on (struct loop *loop, tree name, tree var) | |
2336 | { | |
42acab1c | 2337 | gimple *stmt, *phi; |
ad4a85ad | 2338 | imm_use_iterator iter; |
ad4a85ad | 2339 | |
3b652cc1 | 2340 | replace_ssa_name_symbol (name, var); |
ad4a85ad | 2341 | |
2342 | while (1) | |
2343 | { | |
2344 | phi = NULL; | |
2345 | FOR_EACH_IMM_USE_STMT (stmt, iter, name) | |
2346 | { | |
75a70cf9 | 2347 | if (gimple_code (stmt) == GIMPLE_PHI |
2348 | && flow_bb_inside_loop_p (loop, gimple_bb (stmt))) | |
ad4a85ad | 2349 | { |
2350 | phi = stmt; | |
2351 | BREAK_FROM_IMM_USE_STMT (iter); | |
2352 | } | |
2353 | } | |
2354 | if (!phi) | |
2355 | return; | |
2356 | ||
ad4a85ad | 2357 | name = PHI_RESULT (phi); |
3b652cc1 | 2358 | replace_ssa_name_symbol (name, var); |
ad4a85ad | 2359 | } |
2360 | } | |
2361 | ||
2362 | /* Given an unrolled LOOP after predictive commoning, remove the | |
2363 | register copies arising from phi nodes by changing the base | |
2364 | variables of SSA names. TMP_VARS is the set of the temporary variables | |
2365 | for those we want to perform this. */ | |
2366 | ||
2367 | static void | |
2368 | eliminate_temp_copies (struct loop *loop, bitmap tmp_vars) | |
2369 | { | |
2370 | edge e; | |
1a91d914 | 2371 | gphi *phi; |
42acab1c | 2372 | gimple *stmt; |
75a70cf9 | 2373 | tree name, use, var; |
1a91d914 | 2374 | gphi_iterator psi; |
ad4a85ad | 2375 | |
2376 | e = loop_latch_edge (loop); | |
75a70cf9 | 2377 | for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi)) |
ad4a85ad | 2378 | { |
1a91d914 | 2379 | phi = psi.phi (); |
ad4a85ad | 2380 | name = PHI_RESULT (phi); |
2381 | var = SSA_NAME_VAR (name); | |
ec11736b | 2382 | if (!var || !bitmap_bit_p (tmp_vars, DECL_UID (var))) |
ad4a85ad | 2383 | continue; |
2384 | use = PHI_ARG_DEF_FROM_EDGE (phi, e); | |
2385 | gcc_assert (TREE_CODE (use) == SSA_NAME); | |
2386 | ||
2387 | /* Base all the ssa names in the ud and du chain of NAME on VAR. */ | |
2388 | stmt = SSA_NAME_DEF_STMT (use); | |
75a70cf9 | 2389 | while (gimple_code (stmt) == GIMPLE_PHI |
3fa1e4f2 | 2390 | /* In case we could not unroll the loop enough to eliminate |
2391 | all copies, we may reach the loop header before the defining | |
2392 | statement (in that case, some register copies will be present | |
2393 | in loop latch in the final code, corresponding to the newly | |
2394 | created looparound phi nodes). */ | |
75a70cf9 | 2395 | && gimple_bb (stmt) != loop->header) |
ad4a85ad | 2396 | { |
75a70cf9 | 2397 | gcc_assert (single_pred_p (gimple_bb (stmt))); |
ad4a85ad | 2398 | use = PHI_ARG_DEF (stmt, 0); |
2399 | stmt = SSA_NAME_DEF_STMT (use); | |
2400 | } | |
2401 | ||
2402 | base_names_in_chain_on (loop, use, var); | |
2403 | } | |
2404 | } | |
2405 | ||
2406 | /* Returns true if CHAIN is suitable to be combined. */ | |
2407 | ||
2408 | static bool | |
2409 | chain_can_be_combined_p (chain_p chain) | |
2410 | { | |
2411 | return (!chain->combined | |
2412 | && (chain->type == CT_LOAD || chain->type == CT_COMBINATION)); | |
2413 | } | |
2414 | ||
2415 | /* Returns the modify statement that uses NAME. Skips over assignment | |
2416 | statements, NAME is replaced with the actual name used in the returned | |
2417 | statement. */ | |
2418 | ||
42acab1c | 2419 | static gimple * |
ad4a85ad | 2420 | find_use_stmt (tree *name) |
2421 | { | |
42acab1c | 2422 | gimple *stmt; |
75a70cf9 | 2423 | tree rhs, lhs; |
ad4a85ad | 2424 | |
2425 | /* Skip over assignments. */ | |
2426 | while (1) | |
2427 | { | |
2428 | stmt = single_nonlooparound_use (*name); | |
2429 | if (!stmt) | |
75a70cf9 | 2430 | return NULL; |
ad4a85ad | 2431 | |
75a70cf9 | 2432 | if (gimple_code (stmt) != GIMPLE_ASSIGN) |
2433 | return NULL; | |
ad4a85ad | 2434 | |
75a70cf9 | 2435 | lhs = gimple_assign_lhs (stmt); |
ad4a85ad | 2436 | if (TREE_CODE (lhs) != SSA_NAME) |
75a70cf9 | 2437 | return NULL; |
ad4a85ad | 2438 | |
75a70cf9 | 2439 | if (gimple_assign_copy_p (stmt)) |
2440 | { | |
2441 | rhs = gimple_assign_rhs1 (stmt); | |
2442 | if (rhs != *name) | |
2443 | return NULL; | |
ad4a85ad | 2444 | |
75a70cf9 | 2445 | *name = lhs; |
2446 | } | |
2447 | else if (get_gimple_rhs_class (gimple_assign_rhs_code (stmt)) | |
2448 | == GIMPLE_BINARY_RHS) | |
2449 | return stmt; | |
2450 | else | |
2451 | return NULL; | |
ad4a85ad | 2452 | } |
ad4a85ad | 2453 | } |
2454 | ||
2455 | /* Returns true if we may perform reassociation for operation CODE in TYPE. */ | |
2456 | ||
2457 | static bool | |
2458 | may_reassociate_p (tree type, enum tree_code code) | |
2459 | { | |
2460 | if (FLOAT_TYPE_P (type) | |
2461 | && !flag_unsafe_math_optimizations) | |
2462 | return false; | |
2463 | ||
2464 | return (commutative_tree_code (code) | |
2465 | && associative_tree_code (code)); | |
2466 | } | |
2467 | ||
2468 | /* If the operation used in STMT is associative and commutative, go through the | |
2469 | tree of the same operations and returns its root. Distance to the root | |
2470 | is stored in DISTANCE. */ | |
2471 | ||
42acab1c | 2472 | static gimple * |
2473 | find_associative_operation_root (gimple *stmt, unsigned *distance) | |
ad4a85ad | 2474 | { |
75a70cf9 | 2475 | tree lhs; |
42acab1c | 2476 | gimple *next; |
75a70cf9 | 2477 | enum tree_code code = gimple_assign_rhs_code (stmt); |
2478 | tree type = TREE_TYPE (gimple_assign_lhs (stmt)); | |
ad4a85ad | 2479 | unsigned dist = 0; |
2480 | ||
75a70cf9 | 2481 | if (!may_reassociate_p (type, code)) |
2482 | return NULL; | |
ad4a85ad | 2483 | |
2484 | while (1) | |
2485 | { | |
75a70cf9 | 2486 | lhs = gimple_assign_lhs (stmt); |
ad4a85ad | 2487 | gcc_assert (TREE_CODE (lhs) == SSA_NAME); |
2488 | ||
2489 | next = find_use_stmt (&lhs); | |
75a70cf9 | 2490 | if (!next |
2491 | || gimple_assign_rhs_code (next) != code) | |
ad4a85ad | 2492 | break; |
2493 | ||
2494 | stmt = next; | |
2495 | dist++; | |
2496 | } | |
2497 | ||
2498 | if (distance) | |
2499 | *distance = dist; | |
2500 | return stmt; | |
2501 | } | |
2502 | ||
2503 | /* Returns the common statement in that NAME1 and NAME2 have a use. If there | |
2504 | is no such statement, returns NULL_TREE. In case the operation used on | |
310d2511 | 2505 | NAME1 and NAME2 is associative and commutative, returns the root of the |
ad4a85ad | 2506 | tree formed by this operation instead of the statement that uses NAME1 or |
2507 | NAME2. */ | |
2508 | ||
42acab1c | 2509 | static gimple * |
ad4a85ad | 2510 | find_common_use_stmt (tree *name1, tree *name2) |
2511 | { | |
42acab1c | 2512 | gimple *stmt1, *stmt2; |
ad4a85ad | 2513 | |
2514 | stmt1 = find_use_stmt (name1); | |
2515 | if (!stmt1) | |
75a70cf9 | 2516 | return NULL; |
ad4a85ad | 2517 | |
2518 | stmt2 = find_use_stmt (name2); | |
2519 | if (!stmt2) | |
75a70cf9 | 2520 | return NULL; |
ad4a85ad | 2521 | |
2522 | if (stmt1 == stmt2) | |
2523 | return stmt1; | |
2524 | ||
2525 | stmt1 = find_associative_operation_root (stmt1, NULL); | |
2526 | if (!stmt1) | |
75a70cf9 | 2527 | return NULL; |
ad4a85ad | 2528 | stmt2 = find_associative_operation_root (stmt2, NULL); |
2529 | if (!stmt2) | |
75a70cf9 | 2530 | return NULL; |
ad4a85ad | 2531 | |
75a70cf9 | 2532 | return (stmt1 == stmt2 ? stmt1 : NULL); |
ad4a85ad | 2533 | } |
2534 | ||
2535 | /* Checks whether R1 and R2 are combined together using CODE, with the result | |
2536 | in RSLT_TYPE, in order R1 CODE R2 if SWAP is false and in order R2 CODE R1 | |
2537 | if it is true. If CODE is ERROR_MARK, set these values instead. */ | |
2538 | ||
2539 | static bool | |
2540 | combinable_refs_p (dref r1, dref r2, | |
2541 | enum tree_code *code, bool *swap, tree *rslt_type) | |
2542 | { | |
2543 | enum tree_code acode; | |
2544 | bool aswap; | |
2545 | tree atype; | |
75a70cf9 | 2546 | tree name1, name2; |
42acab1c | 2547 | gimple *stmt; |
ad4a85ad | 2548 | |
2549 | name1 = name_for_ref (r1); | |
2550 | name2 = name_for_ref (r2); | |
2551 | gcc_assert (name1 != NULL_TREE && name2 != NULL_TREE); | |
2552 | ||
2553 | stmt = find_common_use_stmt (&name1, &name2); | |
2554 | ||
f8d7b728 | 2555 | if (!stmt |
2556 | /* A simple post-dominance check - make sure the combination | |
2557 | is executed under the same condition as the references. */ | |
2558 | || (gimple_bb (stmt) != gimple_bb (r1->stmt) | |
2559 | && gimple_bb (stmt) != gimple_bb (r2->stmt))) | |
ad4a85ad | 2560 | return false; |
2561 | ||
75a70cf9 | 2562 | acode = gimple_assign_rhs_code (stmt); |
ad4a85ad | 2563 | aswap = (!commutative_tree_code (acode) |
75a70cf9 | 2564 | && gimple_assign_rhs1 (stmt) != name1); |
2565 | atype = TREE_TYPE (gimple_assign_lhs (stmt)); | |
ad4a85ad | 2566 | |
2567 | if (*code == ERROR_MARK) | |
2568 | { | |
2569 | *code = acode; | |
2570 | *swap = aswap; | |
2571 | *rslt_type = atype; | |
2572 | return true; | |
2573 | } | |
2574 | ||
2575 | return (*code == acode | |
2576 | && *swap == aswap | |
2577 | && *rslt_type == atype); | |
2578 | } | |
2579 | ||
2580 | /* Remove OP from the operation on rhs of STMT, and replace STMT with | |
2581 | an assignment of the remaining operand. */ | |
2582 | ||
2583 | static void | |
42acab1c | 2584 | remove_name_from_operation (gimple *stmt, tree op) |
ad4a85ad | 2585 | { |
75a70cf9 | 2586 | tree other_op; |
2587 | gimple_stmt_iterator si; | |
ad4a85ad | 2588 | |
75a70cf9 | 2589 | gcc_assert (is_gimple_assign (stmt)); |
ad4a85ad | 2590 | |
75a70cf9 | 2591 | if (gimple_assign_rhs1 (stmt) == op) |
2592 | other_op = gimple_assign_rhs2 (stmt); | |
ad4a85ad | 2593 | else |
75a70cf9 | 2594 | other_op = gimple_assign_rhs1 (stmt); |
2595 | ||
2596 | si = gsi_for_stmt (stmt); | |
2597 | gimple_assign_set_rhs_from_tree (&si, other_op); | |
2598 | ||
2599 | /* We should not have reallocated STMT. */ | |
2600 | gcc_assert (gsi_stmt (si) == stmt); | |
2601 | ||
ad4a85ad | 2602 | update_stmt (stmt); |
2603 | } | |
2604 | ||
2605 | /* Reassociates the expression in that NAME1 and NAME2 are used so that they | |
b63803a8 | 2606 | are combined in a single statement, and returns this statement. */ |
ad4a85ad | 2607 | |
42acab1c | 2608 | static gimple * |
b63803a8 | 2609 | reassociate_to_the_same_stmt (tree name1, tree name2) |
ad4a85ad | 2610 | { |
42acab1c | 2611 | gimple *stmt1, *stmt2, *root1, *root2, *s1, *s2; |
1a91d914 | 2612 | gassign *new_stmt, *tmp_stmt; |
75a70cf9 | 2613 | tree new_name, tmp_name, var, r1, r2; |
ad4a85ad | 2614 | unsigned dist1, dist2; |
2615 | enum tree_code code; | |
2616 | tree type = TREE_TYPE (name1); | |
75a70cf9 | 2617 | gimple_stmt_iterator bsi; |
ad4a85ad | 2618 | |
2619 | stmt1 = find_use_stmt (&name1); | |
2620 | stmt2 = find_use_stmt (&name2); | |
2621 | root1 = find_associative_operation_root (stmt1, &dist1); | |
2622 | root2 = find_associative_operation_root (stmt2, &dist2); | |
75a70cf9 | 2623 | code = gimple_assign_rhs_code (stmt1); |
ad4a85ad | 2624 | |
2625 | gcc_assert (root1 && root2 && root1 == root2 | |
75a70cf9 | 2626 | && code == gimple_assign_rhs_code (stmt2)); |
ad4a85ad | 2627 | |
2628 | /* Find the root of the nearest expression in that both NAME1 and NAME2 | |
2629 | are used. */ | |
2630 | r1 = name1; | |
2631 | s1 = stmt1; | |
2632 | r2 = name2; | |
2633 | s2 = stmt2; | |
2634 | ||
2635 | while (dist1 > dist2) | |
2636 | { | |
2637 | s1 = find_use_stmt (&r1); | |
75a70cf9 | 2638 | r1 = gimple_assign_lhs (s1); |
ad4a85ad | 2639 | dist1--; |
2640 | } | |
2641 | while (dist2 > dist1) | |
2642 | { | |
2643 | s2 = find_use_stmt (&r2); | |
75a70cf9 | 2644 | r2 = gimple_assign_lhs (s2); |
ad4a85ad | 2645 | dist2--; |
2646 | } | |
2647 | ||
2648 | while (s1 != s2) | |
2649 | { | |
2650 | s1 = find_use_stmt (&r1); | |
75a70cf9 | 2651 | r1 = gimple_assign_lhs (s1); |
ad4a85ad | 2652 | s2 = find_use_stmt (&r2); |
75a70cf9 | 2653 | r2 = gimple_assign_lhs (s2); |
ad4a85ad | 2654 | } |
2655 | ||
2656 | /* Remove NAME1 and NAME2 from the statements in that they are used | |
2657 | currently. */ | |
2658 | remove_name_from_operation (stmt1, name1); | |
2659 | remove_name_from_operation (stmt2, name2); | |
2660 | ||
2661 | /* Insert the new statement combining NAME1 and NAME2 before S1, and | |
2662 | combine it with the rhs of S1. */ | |
2ac51e48 | 2663 | var = create_tmp_reg (type, "predreastmp"); |
f9e245b2 | 2664 | new_name = make_ssa_name (var); |
e9cf809e | 2665 | new_stmt = gimple_build_assign (new_name, code, name1, name2); |
ad4a85ad | 2666 | |
2ac51e48 | 2667 | var = create_tmp_reg (type, "predreastmp"); |
f9e245b2 | 2668 | tmp_name = make_ssa_name (var); |
75a70cf9 | 2669 | |
2670 | /* Rhs of S1 may now be either a binary expression with operation | |
2671 | CODE, or gimple_val (in case that stmt1 == s1 or stmt2 == s1, | |
2672 | so that name1 or name2 was removed from it). */ | |
e9cf809e | 2673 | tmp_stmt = gimple_build_assign (tmp_name, gimple_assign_rhs_code (s1), |
2674 | gimple_assign_rhs1 (s1), | |
2675 | gimple_assign_rhs2 (s1)); | |
75a70cf9 | 2676 | |
2677 | bsi = gsi_for_stmt (s1); | |
2678 | gimple_assign_set_rhs_with_ops (&bsi, code, new_name, tmp_name); | |
2679 | s1 = gsi_stmt (bsi); | |
ad4a85ad | 2680 | update_stmt (s1); |
2681 | ||
b63803a8 | 2682 | gsi_insert_before (&bsi, new_stmt, GSI_SAME_STMT); |
75a70cf9 | 2683 | gsi_insert_before (&bsi, tmp_stmt, GSI_SAME_STMT); |
ad4a85ad | 2684 | |
2685 | return new_stmt; | |
2686 | } | |
2687 | ||
2688 | /* Returns the statement that combines references R1 and R2. In case R1 | |
2689 | and R2 are not used in the same statement, but they are used with an | |
2690 | associative and commutative operation in the same expression, reassociate | |
b63803a8 | 2691 | the expression so that they are used in the same statement. */ |
ad4a85ad | 2692 | |
42acab1c | 2693 | static gimple * |
b63803a8 | 2694 | stmt_combining_refs (dref r1, dref r2) |
ad4a85ad | 2695 | { |
42acab1c | 2696 | gimple *stmt1, *stmt2; |
ad4a85ad | 2697 | tree name1 = name_for_ref (r1); |
2698 | tree name2 = name_for_ref (r2); | |
2699 | ||
2700 | stmt1 = find_use_stmt (&name1); | |
2701 | stmt2 = find_use_stmt (&name2); | |
2702 | if (stmt1 == stmt2) | |
2703 | return stmt1; | |
2704 | ||
b63803a8 | 2705 | return reassociate_to_the_same_stmt (name1, name2); |
ad4a85ad | 2706 | } |
2707 | ||
2708 | /* Tries to combine chains CH1 and CH2 together. If this succeeds, the | |
2709 | description of the new chain is returned, otherwise we return NULL. */ | |
2710 | ||
2711 | static chain_p | |
2712 | combine_chains (chain_p ch1, chain_p ch2) | |
2713 | { | |
2714 | dref r1, r2, nw; | |
2715 | enum tree_code op = ERROR_MARK; | |
2716 | bool swap = false; | |
2717 | chain_p new_chain; | |
b63803a8 | 2718 | unsigned i; |
ad4a85ad | 2719 | tree rslt_type = NULL_TREE; |
2720 | ||
2721 | if (ch1 == ch2) | |
c84b1d32 | 2722 | return NULL; |
ad4a85ad | 2723 | if (ch1->length != ch2->length) |
2724 | return NULL; | |
2725 | ||
f1f41a6c | 2726 | if (ch1->refs.length () != ch2->refs.length ()) |
ad4a85ad | 2727 | return NULL; |
2728 | ||
f1f41a6c | 2729 | for (i = 0; (ch1->refs.iterate (i, &r1) |
2730 | && ch2->refs.iterate (i, &r2)); i++) | |
ad4a85ad | 2731 | { |
2732 | if (r1->distance != r2->distance) | |
2733 | return NULL; | |
2734 | ||
2735 | if (!combinable_refs_p (r1, r2, &op, &swap, &rslt_type)) | |
2736 | return NULL; | |
2737 | } | |
2738 | ||
2739 | if (swap) | |
a4f59596 | 2740 | std::swap (ch1, ch2); |
ad4a85ad | 2741 | |
2742 | new_chain = XCNEW (struct chain); | |
2743 | new_chain->type = CT_COMBINATION; | |
f4e36c33 | 2744 | new_chain->op = op; |
ad4a85ad | 2745 | new_chain->ch1 = ch1; |
2746 | new_chain->ch2 = ch2; | |
2747 | new_chain->rslt_type = rslt_type; | |
2748 | new_chain->length = ch1->length; | |
2749 | ||
b63803a8 | 2750 | for (i = 0; (ch1->refs.iterate (i, &r1) |
2751 | && ch2->refs.iterate (i, &r2)); i++) | |
2752 | { | |
26dbec0a | 2753 | nw = XCNEW (struct dref_d); |
b63803a8 | 2754 | nw->stmt = stmt_combining_refs (r1, r2); |
ad4a85ad | 2755 | nw->distance = r1->distance; |
7a31ada4 | 2756 | |
42230610 | 2757 | new_chain->refs.safe_push (nw); |
7a31ada4 | 2758 | } |
ad4a85ad | 2759 | |
b63803a8 | 2760 | ch1->combined = true; |
2761 | ch2->combined = true; | |
ad4a85ad | 2762 | return new_chain; |
2763 | } | |
2764 | ||
e02e28c4 | 2765 | /* Recursively update position information of all offspring chains to ROOT |
2766 | chain's position information. */ | |
2767 | ||
2768 | static void | |
2769 | update_pos_for_combined_chains (chain_p root) | |
2770 | { | |
2771 | chain_p ch1 = root->ch1, ch2 = root->ch2; | |
2772 | dref ref, ref1, ref2; | |
2773 | for (unsigned j = 0; (root->refs.iterate (j, &ref) | |
2774 | && ch1->refs.iterate (j, &ref1) | |
2775 | && ch2->refs.iterate (j, &ref2)); ++j) | |
2776 | ref1->pos = ref2->pos = ref->pos; | |
2777 | ||
2778 | if (ch1->type == CT_COMBINATION) | |
2779 | update_pos_for_combined_chains (ch1); | |
2780 | if (ch2->type == CT_COMBINATION) | |
2781 | update_pos_for_combined_chains (ch2); | |
2782 | } | |
2783 | ||
2784 | /* Returns true if statement S1 dominates statement S2. */ | |
2785 | ||
2786 | static bool | |
2787 | pcom_stmt_dominates_stmt_p (gimple *s1, gimple *s2) | |
2788 | { | |
2789 | basic_block bb1 = gimple_bb (s1), bb2 = gimple_bb (s2); | |
2790 | ||
2791 | if (!bb1 || s1 == s2) | |
2792 | return true; | |
2793 | ||
2794 | if (bb1 == bb2) | |
2795 | return gimple_uid (s1) < gimple_uid (s2); | |
2796 | ||
2797 | return dominated_by_p (CDI_DOMINATORS, bb2, bb1); | |
2798 | } | |
2799 | ||
2800 | /* Try to combine the CHAINS in LOOP. */ | |
ad4a85ad | 2801 | |
2802 | static void | |
e02e28c4 | 2803 | try_combine_chains (struct loop *loop, vec<chain_p> *chains) |
ad4a85ad | 2804 | { |
2805 | unsigned i, j; | |
2806 | chain_p ch1, ch2, cch; | |
c2078b80 | 2807 | auto_vec<chain_p> worklist; |
e02e28c4 | 2808 | bool combined_p = false; |
ad4a85ad | 2809 | |
f1f41a6c | 2810 | FOR_EACH_VEC_ELT (*chains, i, ch1) |
ad4a85ad | 2811 | if (chain_can_be_combined_p (ch1)) |
f1f41a6c | 2812 | worklist.safe_push (ch1); |
ad4a85ad | 2813 | |
f1f41a6c | 2814 | while (!worklist.is_empty ()) |
ad4a85ad | 2815 | { |
f1f41a6c | 2816 | ch1 = worklist.pop (); |
ad4a85ad | 2817 | if (!chain_can_be_combined_p (ch1)) |
2818 | continue; | |
2819 | ||
f1f41a6c | 2820 | FOR_EACH_VEC_ELT (*chains, j, ch2) |
ad4a85ad | 2821 | { |
2822 | if (!chain_can_be_combined_p (ch2)) | |
2823 | continue; | |
2824 | ||
2825 | cch = combine_chains (ch1, ch2); | |
2826 | if (cch) | |
2827 | { | |
f1f41a6c | 2828 | worklist.safe_push (cch); |
2829 | chains->safe_push (cch); | |
e02e28c4 | 2830 | combined_p = true; |
2831 | break; | |
2832 | } | |
2833 | } | |
2834 | } | |
2835 | if (!combined_p) | |
2836 | return; | |
2837 | ||
2838 | /* Setup UID for all statements in dominance order. */ | |
886345e6 | 2839 | basic_block *bbs = get_loop_body_in_dom_order (loop); |
e02e28c4 | 2840 | renumber_gimple_stmt_uids_in_blocks (bbs, loop->num_nodes); |
2841 | free (bbs); | |
2842 | ||
2843 | /* Re-association in combined chains may generate statements different to | |
2844 | order of references of the original chain. We need to keep references | |
2845 | of combined chain in dominance order so that all uses will be inserted | |
2846 | after definitions. Note: | |
2847 | A) This is necessary for all combined chains. | |
2848 | B) This is only necessary for ZERO distance references because other | |
2849 | references inherit value from loop carried PHIs. | |
2850 | ||
2851 | We first update position information for all combined chains. */ | |
2852 | dref ref; | |
2853 | for (i = 0; chains->iterate (i, &ch1); ++i) | |
2854 | { | |
2855 | if (ch1->type != CT_COMBINATION || ch1->combined) | |
2856 | continue; | |
2857 | ||
2858 | for (j = 0; ch1->refs.iterate (j, &ref); ++j) | |
2859 | ref->pos = gimple_uid (ref->stmt); | |
2860 | ||
2861 | update_pos_for_combined_chains (ch1); | |
2862 | } | |
2863 | /* Then sort references according to newly updated position information. */ | |
2864 | for (i = 0; chains->iterate (i, &ch1); ++i) | |
2865 | { | |
2866 | if (ch1->type != CT_COMBINATION && !ch1->combined) | |
2867 | continue; | |
2868 | ||
2869 | /* Find the first reference with non-ZERO distance. */ | |
2870 | if (ch1->length == 0) | |
2871 | j = ch1->refs.length(); | |
2872 | else | |
2873 | { | |
2874 | for (j = 0; ch1->refs.iterate (j, &ref); ++j) | |
2875 | if (ref->distance != 0) | |
2876 | break; | |
2877 | } | |
2878 | ||
2879 | /* Sort all ZERO distance references by position. */ | |
2880 | qsort (&ch1->refs[0], j, sizeof (ch1->refs[0]), order_drefs_by_pos); | |
2881 | ||
2882 | if (ch1->combined) | |
2883 | continue; | |
2884 | ||
2885 | /* For ZERO length chain, has_max_use_after must be true since root | |
2886 | combined stmt must dominates others. */ | |
2887 | if (ch1->length == 0) | |
2888 | { | |
2889 | ch1->has_max_use_after = true; | |
2890 | continue; | |
2891 | } | |
2892 | /* Check if there is use at max distance after root for combined chains | |
2893 | and set flag accordingly. */ | |
2894 | ch1->has_max_use_after = false; | |
2895 | gimple *root_stmt = get_chain_root (ch1)->stmt; | |
2896 | for (j = 1; ch1->refs.iterate (j, &ref); ++j) | |
2897 | { | |
2898 | if (ref->distance == ch1->length | |
2899 | && !pcom_stmt_dominates_stmt_p (ref->stmt, root_stmt)) | |
2900 | { | |
2901 | ch1->has_max_use_after = true; | |
ad4a85ad | 2902 | break; |
2903 | } | |
2904 | } | |
2905 | } | |
2906 | } | |
2907 | ||
a652753d | 2908 | /* Prepare initializers for store elimination CHAIN in LOOP. Returns false |
2909 | if this is impossible because one of these initializers may trap, true | |
2910 | otherwise. */ | |
2911 | ||
2912 | static bool | |
e33b3a13 | 2913 | prepare_initializers_chain_store_elim (struct loop *loop, chain_p chain) |
a652753d | 2914 | { |
2915 | unsigned i, n = chain->length; | |
2916 | ||
2917 | /* For now we can't eliminate stores if some of them are conditional | |
2918 | executed. */ | |
2919 | if (!chain->all_always_accessed) | |
2920 | return false; | |
2921 | ||
2922 | /* Nothing to intialize for intra-iteration store elimination. */ | |
2923 | if (n == 0 && chain->type == CT_STORE_STORE) | |
2924 | return true; | |
2925 | ||
e33b3a13 | 2926 | /* For store elimination chain, there is nothing to initialize if stores |
2927 | to be eliminated only store loop invariant values into memory. */ | |
2928 | if (chain->type == CT_STORE_STORE | |
2929 | && is_inv_store_elimination_chain (loop, chain)) | |
2930 | { | |
2931 | chain->inv_store_elimination = true; | |
2932 | return true; | |
2933 | } | |
2934 | ||
a652753d | 2935 | chain->inits.create (n); |
2936 | chain->inits.safe_grow_cleared (n); | |
2937 | ||
2938 | /* For store eliminatin chain like below: | |
2939 | ||
2940 | for (i = 0; i < len; i++) | |
2941 | { | |
2942 | a[i] = 1; | |
2943 | // a[i + 1] = ... | |
2944 | a[i + 2] = 3; | |
2945 | } | |
2946 | ||
2947 | store to a[i + 1] is missed in loop body, it acts like bubbles. The | |
2948 | content of a[i + 1] remain the same if the loop iterates fewer times | |
2949 | than chain->length. We need to set up root variables for such stores | |
2950 | by loading from memory before loop. Note we only need to load bubble | |
2951 | elements because loop body is guaranteed to be executed at least once | |
2952 | after loop's preheader edge. */ | |
2953 | auto_vec<bool> bubbles; | |
2954 | bubbles.safe_grow_cleared (n + 1); | |
2955 | for (i = 0; i < chain->refs.length (); i++) | |
2956 | bubbles[chain->refs[i]->distance] = true; | |
2957 | ||
2958 | struct data_reference *dr = get_chain_root (chain)->ref; | |
2959 | for (i = 0; i < n; i++) | |
2960 | { | |
2961 | if (bubbles[i]) | |
2962 | continue; | |
2963 | ||
2964 | gimple_seq stmts = NULL; | |
2965 | ||
2966 | tree init = ref_at_iteration (dr, (int) 0 - i, &stmts); | |
2967 | if (stmts) | |
2968 | gimple_seq_add_seq_without_update (&chain->init_seq, stmts); | |
2969 | ||
2970 | chain->inits[i] = init; | |
2971 | } | |
2972 | ||
2973 | return true; | |
2974 | } | |
2975 | ||
ad4a85ad | 2976 | /* Prepare initializers for CHAIN in LOOP. Returns false if this is |
2977 | impossible because one of these initializers may trap, true otherwise. */ | |
2978 | ||
2979 | static bool | |
2980 | prepare_initializers_chain (struct loop *loop, chain_p chain) | |
2981 | { | |
2982 | unsigned i, n = (chain->type == CT_INVARIANT) ? 1 : chain->length; | |
2983 | struct data_reference *dr = get_chain_root (chain)->ref; | |
75a70cf9 | 2984 | tree init; |
ad4a85ad | 2985 | dref laref; |
2986 | edge entry = loop_preheader_edge (loop); | |
2987 | ||
a652753d | 2988 | if (chain->type == CT_STORE_STORE) |
2989 | return prepare_initializers_chain_store_elim (loop, chain); | |
2990 | ||
ad4a85ad | 2991 | /* Find the initializers for the variables, and check that they cannot |
2992 | trap. */ | |
f1f41a6c | 2993 | chain->inits.create (n); |
ad4a85ad | 2994 | for (i = 0; i < n; i++) |
f1f41a6c | 2995 | chain->inits.quick_push (NULL_TREE); |
ad4a85ad | 2996 | |
2997 | /* If we have replaced some looparound phi nodes, use their initializers | |
2998 | instead of creating our own. */ | |
f1f41a6c | 2999 | FOR_EACH_VEC_ELT (chain->refs, i, laref) |
ad4a85ad | 3000 | { |
75a70cf9 | 3001 | if (gimple_code (laref->stmt) != GIMPLE_PHI) |
ad4a85ad | 3002 | continue; |
3003 | ||
3004 | gcc_assert (laref->distance > 0); | |
f1f41a6c | 3005 | chain->inits[n - laref->distance] |
3006 | = PHI_ARG_DEF_FROM_EDGE (laref->stmt, entry); | |
ad4a85ad | 3007 | } |
3008 | ||
3009 | for (i = 0; i < n; i++) | |
3010 | { | |
6968257f | 3011 | gimple_seq stmts = NULL; |
3012 | ||
f1f41a6c | 3013 | if (chain->inits[i] != NULL_TREE) |
ad4a85ad | 3014 | continue; |
3015 | ||
99f6be4b | 3016 | init = ref_at_iteration (dr, (int) i - n, &stmts); |
ad4a85ad | 3017 | if (!chain->all_always_accessed && tree_could_trap_p (init)) |
6968257f | 3018 | { |
3019 | gimple_seq_discard (stmts); | |
3020 | return false; | |
3021 | } | |
ad4a85ad | 3022 | |
ad4a85ad | 3023 | if (stmts) |
a481acc5 | 3024 | gimple_seq_add_seq_without_update (&chain->init_seq, stmts); |
ad4a85ad | 3025 | |
f1f41a6c | 3026 | chain->inits[i] = init; |
ad4a85ad | 3027 | } |
3028 | ||
3029 | return true; | |
3030 | } | |
3031 | ||
3032 | /* Prepare initializers for CHAINS in LOOP, and free chains that cannot | |
3033 | be used because the initializers might trap. */ | |
3034 | ||
3035 | static void | |
f1f41a6c | 3036 | prepare_initializers (struct loop *loop, vec<chain_p> chains) |
ad4a85ad | 3037 | { |
3038 | chain_p chain; | |
3039 | unsigned i; | |
3040 | ||
f1f41a6c | 3041 | for (i = 0; i < chains.length (); ) |
ad4a85ad | 3042 | { |
f1f41a6c | 3043 | chain = chains[i]; |
ad4a85ad | 3044 | if (prepare_initializers_chain (loop, chain)) |
3045 | i++; | |
3046 | else | |
3047 | { | |
3048 | release_chain (chain); | |
f1f41a6c | 3049 | chains.unordered_remove (i); |
ad4a85ad | 3050 | } |
3051 | } | |
3052 | } | |
3053 | ||
a652753d | 3054 | /* Generates finalizer memory references for CHAIN in LOOP. Returns true |
3055 | if finalizer code for CHAIN can be generated, otherwise false. */ | |
3056 | ||
3057 | static bool | |
3058 | prepare_finalizers_chain (struct loop *loop, chain_p chain) | |
3059 | { | |
3060 | unsigned i, n = chain->length; | |
3061 | struct data_reference *dr = get_chain_root (chain)->ref; | |
3062 | tree fini, niters = number_of_latch_executions (loop); | |
3063 | ||
3064 | /* For now we can't eliminate stores if some of them are conditional | |
3065 | executed. */ | |
3066 | if (!chain->all_always_accessed) | |
3067 | return false; | |
3068 | ||
3069 | chain->finis.create (n); | |
3070 | for (i = 0; i < n; i++) | |
3071 | chain->finis.quick_push (NULL_TREE); | |
3072 | ||
3073 | /* We never use looparound phi node for store elimination chains. */ | |
3074 | ||
3075 | /* Find the finalizers for the variables, and check that they cannot | |
3076 | trap. */ | |
3077 | for (i = 0; i < n; i++) | |
3078 | { | |
3079 | gimple_seq stmts = NULL; | |
3080 | gcc_assert (chain->finis[i] == NULL_TREE); | |
3081 | ||
3082 | if (TREE_CODE (niters) != INTEGER_CST && TREE_CODE (niters) != SSA_NAME) | |
3083 | { | |
cf071e9e | 3084 | niters = unshare_expr (niters); |
a652753d | 3085 | niters = force_gimple_operand (niters, &stmts, true, NULL); |
3086 | if (stmts) | |
3087 | { | |
3088 | gimple_seq_add_seq_without_update (&chain->fini_seq, stmts); | |
3089 | stmts = NULL; | |
3090 | } | |
3091 | } | |
3092 | fini = ref_at_iteration (dr, (int) 0 - i, &stmts, niters); | |
3093 | if (stmts) | |
3094 | gimple_seq_add_seq_without_update (&chain->fini_seq, stmts); | |
3095 | ||
3096 | chain->finis[i] = fini; | |
3097 | } | |
3098 | ||
3099 | return true; | |
3100 | } | |
3101 | ||
3102 | /* Generates finalizer memory reference for CHAINS in LOOP. Returns true | |
3103 | if finalizer code generation for CHAINS breaks loop closed ssa form. */ | |
3104 | ||
3105 | static bool | |
3106 | prepare_finalizers (struct loop *loop, vec<chain_p> chains) | |
3107 | { | |
3108 | chain_p chain; | |
3109 | unsigned i; | |
3110 | bool loop_closed_ssa = false; | |
3111 | ||
3112 | for (i = 0; i < chains.length ();) | |
3113 | { | |
3114 | chain = chains[i]; | |
3115 | ||
3116 | /* Finalizer is only necessary for inter-iteration store elimination | |
3117 | chains. */ | |
3118 | if (chain->length == 0 || chain->type != CT_STORE_STORE) | |
3119 | { | |
3120 | i++; | |
3121 | continue; | |
3122 | } | |
3123 | ||
3124 | if (prepare_finalizers_chain (loop, chain)) | |
3125 | { | |
3126 | i++; | |
89c72921 | 3127 | /* Be conservative, assume loop closed ssa form is corrupted |
3128 | by store-store chain. Though it's not always the case if | |
3129 | eliminated stores only store loop invariant values into | |
3130 | memory. */ | |
3131 | loop_closed_ssa = true; | |
a652753d | 3132 | } |
3133 | else | |
3134 | { | |
3135 | release_chain (chain); | |
3136 | chains.unordered_remove (i); | |
3137 | } | |
3138 | } | |
3139 | return loop_closed_ssa; | |
3140 | } | |
3141 | ||
a481acc5 | 3142 | /* Insert all initializing gimple stmts into loop's entry edge. */ |
3143 | ||
3144 | static void | |
3145 | insert_init_seqs (struct loop *loop, vec<chain_p> chains) | |
3146 | { | |
3147 | unsigned i; | |
3148 | edge entry = loop_preheader_edge (loop); | |
3149 | ||
3150 | for (i = 0; i < chains.length (); ++i) | |
3151 | if (chains[i]->init_seq) | |
3152 | { | |
3153 | gsi_insert_seq_on_edge_immediate (entry, chains[i]->init_seq); | |
3154 | chains[i]->init_seq = NULL; | |
3155 | } | |
3156 | } | |
3157 | ||
a652753d | 3158 | /* Performs predictive commoning for LOOP. Sets bit 1<<0 of return value |
3159 | if LOOP was unrolled; Sets bit 1<<1 of return value if loop closed ssa | |
3160 | form was corrupted. */ | |
ad4a85ad | 3161 | |
a652753d | 3162 | static unsigned |
ad4a85ad | 3163 | tree_predictive_commoning_loop (struct loop *loop) |
3164 | { | |
f1f41a6c | 3165 | vec<data_reference_p> datarefs; |
3166 | vec<ddr_p> dependences; | |
ad4a85ad | 3167 | struct component *components; |
1e094109 | 3168 | vec<chain_p> chains = vNULL; |
ad4a85ad | 3169 | unsigned unroll_factor; |
3170 | struct tree_niter_desc desc; | |
a652753d | 3171 | bool unroll = false, loop_closed_ssa = false; |
ad4a85ad | 3172 | edge exit; |
ad4a85ad | 3173 | |
3174 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3175 | fprintf (dump_file, "Processing loop %d\n", loop->num); | |
3176 | ||
c4dd22f7 | 3177 | /* Nothing for predicitive commoning if loop only iterates 1 time. */ |
3178 | if (get_max_loop_iterations_int (loop) == 0) | |
3179 | { | |
3180 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3181 | fprintf (dump_file, "Loop iterates only 1 time, nothing to do.\n"); | |
3182 | ||
a652753d | 3183 | return 0; |
c4dd22f7 | 3184 | } |
3185 | ||
ad4a85ad | 3186 | /* Find the data references and split them into components according to their |
3187 | dependence relations. */ | |
4997014d | 3188 | auto_vec<loop_p, 3> loop_nest; |
f1f41a6c | 3189 | dependences.create (10); |
e85cf4e5 | 3190 | datarefs.create (10); |
713f1f14 | 3191 | if (! compute_data_dependences_for_loop (loop, true, &loop_nest, &datarefs, |
3192 | &dependences)) | |
3193 | { | |
3194 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3195 | fprintf (dump_file, "Cannot analyze data dependencies\n"); | |
713f1f14 | 3196 | free_data_refs (datarefs); |
3197 | free_dependence_relations (dependences); | |
a652753d | 3198 | return 0; |
713f1f14 | 3199 | } |
3200 | ||
ad4a85ad | 3201 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3202 | dump_data_dependence_relations (dump_file, dependences); | |
3203 | ||
3204 | components = split_data_refs_to_components (loop, datarefs, dependences); | |
f1f41a6c | 3205 | loop_nest.release (); |
ad4a85ad | 3206 | free_dependence_relations (dependences); |
3207 | if (!components) | |
3208 | { | |
3209 | free_data_refs (datarefs); | |
f037f351 | 3210 | free_affine_expand_cache (&name_expansions); |
a652753d | 3211 | return 0; |
ad4a85ad | 3212 | } |
3213 | ||
3214 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3215 | { | |
3216 | fprintf (dump_file, "Initial state:\n\n"); | |
3217 | dump_components (dump_file, components); | |
3218 | } | |
3219 | ||
3220 | /* Find the suitable components and split them into chains. */ | |
3221 | components = filter_suitable_components (loop, components); | |
3222 | ||
035def86 | 3223 | auto_bitmap tmp_vars; |
ad4a85ad | 3224 | looparound_phis = BITMAP_ALLOC (NULL); |
3225 | determine_roots (loop, components, &chains); | |
3226 | release_components (components); | |
3227 | ||
f1f41a6c | 3228 | if (!chains.exists ()) |
ad4a85ad | 3229 | { |
3230 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3231 | fprintf (dump_file, | |
3232 | "Predictive commoning failed: no suitable chains\n"); | |
3233 | goto end; | |
3234 | } | |
3235 | prepare_initializers (loop, chains); | |
a652753d | 3236 | loop_closed_ssa = prepare_finalizers (loop, chains); |
ad4a85ad | 3237 | |
3238 | /* Try to combine the chains that are always worked with together. */ | |
e02e28c4 | 3239 | try_combine_chains (loop, &chains); |
ad4a85ad | 3240 | |
a481acc5 | 3241 | insert_init_seqs (loop, chains); |
3242 | ||
ad4a85ad | 3243 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3244 | { | |
3245 | fprintf (dump_file, "Before commoning:\n\n"); | |
3246 | dump_chains (dump_file, chains); | |
3247 | } | |
3248 | ||
3249 | /* Determine the unroll factor, and if the loop should be unrolled, ensure | |
3250 | that its number of iterations is divisible by the factor. */ | |
3251 | unroll_factor = determine_unroll_factor (chains); | |
3252 | scev_reset (); | |
286fa508 | 3253 | unroll = (unroll_factor > 1 |
3254 | && can_unroll_loop_p (loop, unroll_factor, &desc)); | |
ad4a85ad | 3255 | exit = single_dom_exit (loop); |
3256 | ||
3257 | /* Execute the predictive commoning transformations, and possibly unroll the | |
3258 | loop. */ | |
3259 | if (unroll) | |
3260 | { | |
3261 | struct epcc_data dta; | |
3262 | ||
3263 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3264 | fprintf (dump_file, "Unrolling %u times.\n", unroll_factor); | |
3265 | ||
3266 | dta.chains = chains; | |
3267 | dta.tmp_vars = tmp_vars; | |
48e1416a | 3268 | |
ad4a85ad | 3269 | update_ssa (TODO_update_ssa_only_virtuals); |
3270 | ||
3271 | /* Cfg manipulations performed in tree_transform_and_unroll_loop before | |
3272 | execute_pred_commoning_cbck is called may cause phi nodes to be | |
3273 | reallocated, which is a problem since CHAINS may point to these | |
3274 | statements. To fix this, we store the ssa names defined by the | |
3275 | phi nodes here instead of the phi nodes themselves, and restore | |
3276 | the phi nodes in execute_pred_commoning_cbck. A bit hacky. */ | |
3277 | replace_phis_by_defined_names (chains); | |
3278 | ||
3279 | tree_transform_and_unroll_loop (loop, unroll_factor, exit, &desc, | |
3280 | execute_pred_commoning_cbck, &dta); | |
3281 | eliminate_temp_copies (loop, tmp_vars); | |
3282 | } | |
3283 | else | |
3284 | { | |
3285 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3286 | fprintf (dump_file, | |
3287 | "Executing predictive commoning without unrolling.\n"); | |
3288 | execute_pred_commoning (loop, chains, tmp_vars); | |
3289 | } | |
3290 | ||
3291 | end: ; | |
3292 | release_chains (chains); | |
3293 | free_data_refs (datarefs); | |
ad4a85ad | 3294 | BITMAP_FREE (looparound_phis); |
3295 | ||
3296 | free_affine_expand_cache (&name_expansions); | |
3297 | ||
a652753d | 3298 | return (unroll ? 1 : 0) | (loop_closed_ssa ? 2 : 0); |
ad4a85ad | 3299 | } |
3300 | ||
3301 | /* Runs predictive commoning. */ | |
3302 | ||
eb2a640e | 3303 | unsigned |
ad4a85ad | 3304 | tree_predictive_commoning (void) |
3305 | { | |
ad4a85ad | 3306 | struct loop *loop; |
a652753d | 3307 | unsigned ret = 0, changed = 0; |
ad4a85ad | 3308 | |
3309 | initialize_original_copy_tables (); | |
f21d4d00 | 3310 | FOR_EACH_LOOP (loop, LI_ONLY_INNERMOST) |
7baffbd3 | 3311 | if (optimize_loop_for_speed_p (loop)) |
3312 | { | |
a652753d | 3313 | changed |= tree_predictive_commoning_loop (loop); |
7baffbd3 | 3314 | } |
a652753d | 3315 | free_original_copy_tables (); |
ad4a85ad | 3316 | |
a652753d | 3317 | if (changed > 0) |
ad4a85ad | 3318 | { |
3319 | scev_reset (); | |
a652753d | 3320 | |
3321 | if (changed > 1) | |
3322 | rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa); | |
3323 | ||
eb2a640e | 3324 | ret = TODO_cleanup_cfg; |
ad4a85ad | 3325 | } |
eb2a640e | 3326 | |
3327 | return ret; | |
ad4a85ad | 3328 | } |
64641360 | 3329 | |
3330 | /* Predictive commoning Pass. */ | |
3331 | ||
3332 | static unsigned | |
b3083327 | 3333 | run_tree_predictive_commoning (struct function *fun) |
64641360 | 3334 | { |
b3083327 | 3335 | if (number_of_loops (fun) <= 1) |
64641360 | 3336 | return 0; |
3337 | ||
3338 | return tree_predictive_commoning (); | |
3339 | } | |
3340 | ||
64641360 | 3341 | namespace { |
3342 | ||
3343 | const pass_data pass_data_predcom = | |
3344 | { | |
3345 | GIMPLE_PASS, /* type */ | |
3346 | "pcom", /* name */ | |
3347 | OPTGROUP_LOOP, /* optinfo_flags */ | |
64641360 | 3348 | TV_PREDCOM, /* tv_id */ |
3349 | PROP_cfg, /* properties_required */ | |
3350 | 0, /* properties_provided */ | |
3351 | 0, /* properties_destroyed */ | |
3352 | 0, /* todo_flags_start */ | |
3353 | TODO_update_ssa_only_virtuals, /* todo_flags_finish */ | |
3354 | }; | |
3355 | ||
3356 | class pass_predcom : public gimple_opt_pass | |
3357 | { | |
3358 | public: | |
3359 | pass_predcom (gcc::context *ctxt) | |
3360 | : gimple_opt_pass (pass_data_predcom, ctxt) | |
3361 | {} | |
3362 | ||
3363 | /* opt_pass methods: */ | |
31315c24 | 3364 | virtual bool gate (function *) { return flag_predictive_commoning != 0; } |
b3083327 | 3365 | virtual unsigned int execute (function *fun) |
65b0537f | 3366 | { |
b3083327 | 3367 | return run_tree_predictive_commoning (fun); |
65b0537f | 3368 | } |
64641360 | 3369 | |
3370 | }; // class pass_predcom | |
3371 | ||
3372 | } // anon namespace | |
3373 | ||
3374 | gimple_opt_pass * | |
3375 | make_pass_predcom (gcc::context *ctxt) | |
3376 | { | |
3377 | return new pass_predcom (ctxt); | |
3378 | } | |
3379 | ||
3380 |