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bbc8a8dc | 1 | /* Predictive commoning. |
8d9254fc | 2 | Copyright (C) 2005-2020 Free Software Foundation, Inc. |
b8698a0f | 3 | |
bbc8a8dc | 4 | This file is part of GCC. |
b8698a0f | 5 | |
bbc8a8dc ZD |
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 | |
9dcd6f09 | 8 | Free Software Foundation; either version 3, or (at your option) any |
bbc8a8dc | 9 | later version. |
b8698a0f | 10 | |
bbc8a8dc ZD |
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. | |
b8698a0f | 15 | |
bbc8a8dc | 16 | You should have received a copy of the GNU General Public License |
9dcd6f09 NC |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
bbc8a8dc ZD |
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: | |
b8698a0f | 32 | |
bbc8a8dc ZD |
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. | |
b8698a0f | 66 | |
bbc8a8dc ZD |
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 | |
b8698a0f | 79 | single root reference of the chain (adjusting their distance |
bbc8a8dc ZD |
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 | |
073a8998 | 102 | of a reference reusing its value. Variables R0 up to RN are created, |
bbc8a8dc ZD |
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. | |
b8698a0f | 135 | |
bbc8a8dc ZD |
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 | ||
d9c259ef BC |
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 | } | |
bbc8a8dc | 168 | |
d9c259ef | 169 | It can be replaced with: |
bbc8a8dc | 170 | |
d9c259ef BC |
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; | |
bbc8a8dc | 182 | |
d9c259ef BC |
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 | ||
9cdcebf9 BC |
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 | ||
d9c259ef BC |
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. | |
bbc8a8dc ZD |
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" | |
c7131fb2 | 210 | #include "backend.h" |
957060b5 | 211 | #include "rtl.h" |
bbc8a8dc | 212 | #include "tree.h" |
c7131fb2 | 213 | #include "gimple.h" |
957060b5 AM |
214 | #include "predict.h" |
215 | #include "tree-pass.h" | |
c7131fb2 | 216 | #include "ssa.h" |
957060b5 | 217 | #include "gimple-pretty-print.h" |
c7131fb2 | 218 | #include "alias.h" |
40e23961 | 219 | #include "fold-const.h" |
bbc8a8dc | 220 | #include "cfgloop.h" |
2fb9a547 | 221 | #include "tree-eh.h" |
45b0be94 | 222 | #include "gimplify.h" |
5be5c238 | 223 | #include "gimple-iterator.h" |
18f429e2 | 224 | #include "gimplify-me.h" |
e28030cf AM |
225 | #include "tree-ssa-loop-ivopts.h" |
226 | #include "tree-ssa-loop-manip.h" | |
227 | #include "tree-ssa-loop-niter.h" | |
442b4905 AM |
228 | #include "tree-ssa-loop.h" |
229 | #include "tree-into-ssa.h" | |
230 | #include "tree-dfa.h" | |
7a300452 | 231 | #include "tree-ssa.h" |
bbc8a8dc ZD |
232 | #include "tree-data-ref.h" |
233 | #include "tree-scalar-evolution.h" | |
bbc8a8dc | 234 | #include "tree-affine.h" |
59537744 | 235 | #include "builtins.h" |
bbc8a8dc ZD |
236 | |
237 | /* The maximum number of iterations between the considered memory | |
238 | references. */ | |
239 | ||
240 | #define MAX_DISTANCE (target_avail_regs < 16 ? 4 : 8) | |
b8698a0f | 241 | |
726a989a RB |
242 | /* Data references (or phi nodes that carry data reference values across |
243 | loop iterations). */ | |
bbc8a8dc | 244 | |
6c1dae73 | 245 | typedef class dref_d |
bbc8a8dc | 246 | { |
6c1dae73 | 247 | public: |
bbc8a8dc ZD |
248 | /* The reference itself. */ |
249 | struct data_reference *ref; | |
250 | ||
251 | /* The statement in that the reference appears. */ | |
355fe088 | 252 | gimple *stmt; |
726a989a RB |
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; | |
bbc8a8dc ZD |
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. */ | |
807e902e | 264 | widest_int offset; |
bbc8a8dc ZD |
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 | ||
bbc8a8dc ZD |
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 | ||
d9c259ef BC |
288 | /* There are only stores in the chain. */ |
289 | CT_STORE_STORE, | |
290 | ||
bbc8a8dc ZD |
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. */ | |
82d6e6fc | 304 | enum tree_code op; |
bbc8a8dc ZD |
305 | tree rslt_type; |
306 | struct chain *ch1, *ch2; | |
307 | ||
308 | /* The references in the chain. */ | |
9771b263 | 309 | vec<dref> refs; |
bbc8a8dc ZD |
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. */ | |
9771b263 | 315 | vec<tree> vars; |
bbc8a8dc ZD |
316 | |
317 | /* Initializers for the variables. */ | |
9771b263 | 318 | vec<tree> inits; |
bbc8a8dc | 319 | |
d9c259ef BC |
320 | /* Finalizers for the eliminated stores. */ |
321 | vec<tree> finis; | |
322 | ||
aa4de160 BC |
323 | /* gimple stmts intializing the initial variables of the chain. */ |
324 | gimple_seq init_seq; | |
325 | ||
d9c259ef BC |
326 | /* gimple stmts finalizing the eliminated stores of the chain. */ |
327 | gimple_seq fini_seq; | |
328 | ||
bbc8a8dc ZD |
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; | |
39ff50ce BC |
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; | |
bbc8a8dc ZD |
342 | } *chain_p; |
343 | ||
bbc8a8dc ZD |
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. */ | |
9771b263 | 365 | vec<dref> refs; |
bbc8a8dc ZD |
366 | |
367 | /* What we know about the step of the references in the component. */ | |
368 | enum ref_step_type comp_step; | |
369 | ||
d9c259ef BC |
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 | ||
bbc8a8dc ZD |
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 | ||
39c8aaa4 | 384 | static hash_map<tree, name_expansion *> *name_expansions; |
bbc8a8dc ZD |
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 "); | |
807e902e | 400 | print_decs (ref->offset, file); |
bbc8a8dc ZD |
401 | fprintf (file, "\n"); |
402 | ||
403 | fprintf (file, " distance %u\n", ref->distance); | |
404 | } | |
405 | else | |
406 | { | |
726a989a | 407 | if (gimple_code (ref->stmt) == GIMPLE_PHI) |
bbc8a8dc ZD |
408 | fprintf (file, " looparound ref\n"); |
409 | else | |
410 | fprintf (file, " combination ref\n"); | |
411 | fprintf (file, " in statement "); | |
726a989a | 412 | print_gimple_stmt (file, ref->stmt, 0, TDF_SLIM); |
bbc8a8dc ZD |
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 | ||
d9c259ef BC |
444 | case CT_STORE_STORE: |
445 | chain_type = "Store-stores"; | |
446 | break; | |
447 | ||
bbc8a8dc ZD |
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 ", | |
82d6e6fc | 465 | (void *) chain->ch1, op_symbol_code (chain->op), |
bbc8a8dc ZD |
466 | (void *) chain->ch2); |
467 | print_generic_expr (file, chain->rslt_type, TDF_SLIM); | |
468 | fprintf (file, "\n"); | |
469 | } | |
470 | ||
9771b263 | 471 | if (chain->vars.exists ()) |
bbc8a8dc ZD |
472 | { |
473 | fprintf (file, " vars"); | |
9771b263 | 474 | FOR_EACH_VEC_ELT (chain->vars, i, var) |
bbc8a8dc ZD |
475 | { |
476 | fprintf (file, " "); | |
477 | print_generic_expr (file, var, TDF_SLIM); | |
478 | } | |
479 | fprintf (file, "\n"); | |
480 | } | |
481 | ||
9771b263 | 482 | if (chain->inits.exists ()) |
bbc8a8dc ZD |
483 | { |
484 | fprintf (file, " inits"); | |
9771b263 | 485 | FOR_EACH_VEC_ELT (chain->inits, i, var) |
bbc8a8dc ZD |
486 | { |
487 | fprintf (file, " "); | |
488 | print_generic_expr (file, var, TDF_SLIM); | |
489 | } | |
490 | fprintf (file, "\n"); | |
491 | } | |
492 | ||
493 | fprintf (file, " references:\n"); | |
9771b263 | 494 | FOR_EACH_VEC_ELT (chain->refs, i, a) |
bbc8a8dc ZD |
495 | dump_dref (file, a); |
496 | ||
497 | fprintf (file, "\n"); | |
498 | } | |
499 | ||
500 | /* Dumps CHAINS to FILE. */ | |
501 | ||
9771b263 | 502 | extern void dump_chains (FILE *, vec<chain_p> ); |
bbc8a8dc | 503 | void |
9771b263 | 504 | dump_chains (FILE *file, vec<chain_p> chains) |
bbc8a8dc ZD |
505 | { |
506 | chain_p chain; | |
507 | unsigned i; | |
508 | ||
9771b263 | 509 | FOR_EACH_VEC_ELT (chains, i, chain) |
bbc8a8dc ZD |
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)" : ""); | |
9771b263 | 524 | FOR_EACH_VEC_ELT (comp->refs, i, a) |
bbc8a8dc ZD |
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 | ||
9771b263 | 552 | FOR_EACH_VEC_ELT (chain->refs, i, ref) |
bbc8a8dc ZD |
553 | free (ref); |
554 | ||
9771b263 DN |
555 | chain->refs.release (); |
556 | chain->vars.release (); | |
557 | chain->inits.release (); | |
aa4de160 BC |
558 | if (chain->init_seq) |
559 | gimple_seq_discard (chain->init_seq); | |
bbc8a8dc | 560 | |
d9c259ef BC |
561 | chain->finis.release (); |
562 | if (chain->fini_seq) | |
563 | gimple_seq_discard (chain->fini_seq); | |
564 | ||
bbc8a8dc ZD |
565 | free (chain); |
566 | } | |
567 | ||
568 | /* Frees CHAINS. */ | |
569 | ||
570 | static void | |
9771b263 | 571 | release_chains (vec<chain_p> chains) |
bbc8a8dc ZD |
572 | { |
573 | unsigned i; | |
574 | chain_p chain; | |
575 | ||
9771b263 | 576 | FOR_EACH_VEC_ELT (chains, i, chain) |
bbc8a8dc | 577 | release_chain (chain); |
9771b263 | 578 | chains.release (); |
bbc8a8dc ZD |
579 | } |
580 | ||
581 | /* Frees a component COMP. */ | |
582 | ||
583 | static void | |
584 | release_component (struct component *comp) | |
585 | { | |
9771b263 | 586 | comp->refs.release (); |
bbc8a8dc ZD |
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 | |
64fb0d3a | 658 | || TREE_THIS_VOLATILE (ref) |
7e80c6bf EB |
659 | || !is_gimple_reg_type (TREE_TYPE (ref)) |
660 | || tree_could_throw_p (ref)) | |
bbc8a8dc ZD |
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 | { | |
0d82a1c8 | 678 | tree type = TREE_TYPE (DR_OFFSET (dr)); |
bbc8a8dc ZD |
679 | aff_tree delta; |
680 | ||
0d82a1c8 | 681 | tree_to_aff_combination_expand (DR_OFFSET (dr), type, offset, |
bbc8a8dc | 682 | &name_expansions); |
c0a46545 | 683 | aff_combination_const (&delta, type, wi::to_poly_widest (DR_INIT (dr))); |
bbc8a8dc ZD |
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, | |
cc8bea09 | 695 | poly_widest_int *off) |
bbc8a8dc ZD |
696 | { |
697 | aff_tree diff, baseb, step; | |
49379cb1 ZD |
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)); | |
36618b93 | 703 | if (!useless_type_conversion_p (typeb, typea)) |
49379cb1 | 704 | return false; |
bbc8a8dc ZD |
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. */ | |
807e902e | 716 | *off = 0; |
bbc8a8dc ZD |
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); | |
807e902e | 725 | aff_combination_scale (&baseb, -1); |
bbc8a8dc ZD |
726 | aff_combination_add (&diff, &baseb); |
727 | ||
0d82a1c8 | 728 | tree_to_aff_combination_expand (DR_STEP (a), TREE_TYPE (DR_STEP (a)), |
bbc8a8dc ZD |
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 | |
99b1c316 | 737 | last_always_executed_block (class loop *loop) |
bbc8a8dc ZD |
738 | { |
739 | unsigned i; | |
9771b263 | 740 | vec<edge> exits = get_loop_exit_edges (loop); |
bbc8a8dc ZD |
741 | edge ex; |
742 | basic_block last = loop->latch; | |
743 | ||
9771b263 | 744 | FOR_EACH_VEC_ELT (exits, i, ex) |
bbc8a8dc | 745 | last = nearest_common_dominator (CDI_DOMINATORS, last, ex->src); |
9771b263 | 746 | exits.release (); |
bbc8a8dc ZD |
747 | |
748 | return last; | |
749 | } | |
750 | ||
751 | /* Splits dependence graph on DATAREFS described by DEPENDS to components. */ | |
752 | ||
753 | static struct component * | |
99b1c316 | 754 | split_data_refs_to_components (class loop *loop, |
9771b263 DN |
755 | vec<data_reference_p> datarefs, |
756 | vec<ddr_p> depends) | |
bbc8a8dc | 757 | { |
9771b263 | 758 | unsigned i, n = datarefs.length (); |
bbc8a8dc ZD |
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; | |
d9c259ef BC |
767 | /* Don't do store elimination if loop has multiple exit edges. */ |
768 | bool eliminate_store_p = single_exit (loop) != NULL; | |
bbc8a8dc | 769 | basic_block last_always_executed = last_always_executed_block (loop); |
6cedf5d8 | 770 | auto_bitmap no_store_store_comps; |
b8698a0f | 771 | |
9771b263 | 772 | FOR_EACH_VEC_ELT (datarefs, i, dr) |
bbc8a8dc ZD |
773 | { |
774 | if (!DR_REF (dr)) | |
775 | { | |
776 | /* A fake reference for call or asm_expr that may clobber memory; | |
777 | just fail. */ | |
778 | goto end; | |
779 | } | |
5ce9450f JJ |
780 | /* predcom pass isn't prepared to handle calls with data references. */ |
781 | if (is_gimple_call (DR_STMT (dr))) | |
782 | goto end; | |
5417e022 | 783 | dr->aux = (void *) (size_t) i; |
bbc8a8dc ZD |
784 | comp_father[i] = i; |
785 | comp_size[i] = 1; | |
786 | } | |
787 | ||
788 | /* A component reserved for the "bad" data references. */ | |
789 | comp_father[n] = n; | |
790 | comp_size[n] = 1; | |
791 | ||
9771b263 | 792 | FOR_EACH_VEC_ELT (datarefs, i, dr) |
bbc8a8dc ZD |
793 | { |
794 | enum ref_step_type dummy; | |
795 | ||
796 | if (!suitable_reference_p (dr, &dummy)) | |
797 | { | |
5417e022 | 798 | ia = (unsigned) (size_t) dr->aux; |
bbc8a8dc ZD |
799 | merge_comps (comp_father, comp_size, n, ia); |
800 | } | |
801 | } | |
802 | ||
9771b263 | 803 | FOR_EACH_VEC_ELT (depends, i, ddr) |
bbc8a8dc | 804 | { |
cc8bea09 | 805 | poly_widest_int dummy_off; |
bbc8a8dc ZD |
806 | |
807 | if (DDR_ARE_DEPENDENT (ddr) == chrec_known) | |
808 | continue; | |
809 | ||
810 | dra = DDR_A (ddr); | |
811 | drb = DDR_B (ddr); | |
d9c259ef BC |
812 | |
813 | /* Don't do store elimination if there is any unknown dependence for | |
814 | any store data reference. */ | |
815 | if ((DR_IS_WRITE (dra) || DR_IS_WRITE (drb)) | |
816 | && (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know | |
817 | || DDR_NUM_DIST_VECTS (ddr) == 0)) | |
818 | eliminate_store_p = false; | |
819 | ||
5417e022 ZD |
820 | ia = component_of (comp_father, (unsigned) (size_t) dra->aux); |
821 | ib = component_of (comp_father, (unsigned) (size_t) drb->aux); | |
bbc8a8dc ZD |
822 | if (ia == ib) |
823 | continue; | |
824 | ||
825 | bad = component_of (comp_father, n); | |
826 | ||
827 | /* If both A and B are reads, we may ignore unsuitable dependences. */ | |
41626746 JJ |
828 | if (DR_IS_READ (dra) && DR_IS_READ (drb)) |
829 | { | |
830 | if (ia == bad || ib == bad | |
831 | || !determine_offset (dra, drb, &dummy_off)) | |
832 | continue; | |
833 | } | |
834 | /* If A is read and B write or vice versa and there is unsuitable | |
835 | dependence, instead of merging both components into a component | |
836 | that will certainly not pass suitable_component_p, just put the | |
837 | read into bad component, perhaps at least the write together with | |
838 | all the other data refs in it's component will be optimizable. */ | |
839 | else if (DR_IS_READ (dra) && ib != bad) | |
840 | { | |
841 | if (ia == bad) | |
6cedf5d8 RS |
842 | { |
843 | bitmap_set_bit (no_store_store_comps, ib); | |
844 | continue; | |
845 | } | |
41626746 JJ |
846 | else if (!determine_offset (dra, drb, &dummy_off)) |
847 | { | |
6cedf5d8 | 848 | bitmap_set_bit (no_store_store_comps, ib); |
41626746 JJ |
849 | merge_comps (comp_father, comp_size, bad, ia); |
850 | continue; | |
851 | } | |
852 | } | |
853 | else if (DR_IS_READ (drb) && ia != bad) | |
854 | { | |
855 | if (ib == bad) | |
6cedf5d8 RS |
856 | { |
857 | bitmap_set_bit (no_store_store_comps, ia); | |
858 | continue; | |
859 | } | |
41626746 JJ |
860 | else if (!determine_offset (dra, drb, &dummy_off)) |
861 | { | |
6cedf5d8 | 862 | bitmap_set_bit (no_store_store_comps, ia); |
41626746 JJ |
863 | merge_comps (comp_father, comp_size, bad, ib); |
864 | continue; | |
865 | } | |
866 | } | |
d9c259ef BC |
867 | else if (DR_IS_WRITE (dra) && DR_IS_WRITE (drb) |
868 | && ia != bad && ib != bad | |
869 | && !determine_offset (dra, drb, &dummy_off)) | |
870 | { | |
871 | merge_comps (comp_father, comp_size, bad, ia); | |
872 | merge_comps (comp_father, comp_size, bad, ib); | |
873 | continue; | |
874 | } | |
b8698a0f | 875 | |
bbc8a8dc ZD |
876 | merge_comps (comp_father, comp_size, ia, ib); |
877 | } | |
878 | ||
d9c259ef BC |
879 | if (eliminate_store_p) |
880 | { | |
881 | tree niters = number_of_latch_executions (loop); | |
882 | ||
883 | /* Don't do store elimination if niters info is unknown because stores | |
884 | in the last iteration can't be eliminated and we need to recover it | |
885 | after loop. */ | |
886 | eliminate_store_p = (niters != NULL_TREE && niters != chrec_dont_know); | |
887 | } | |
888 | ||
bbc8a8dc ZD |
889 | comps = XCNEWVEC (struct component *, n); |
890 | bad = component_of (comp_father, n); | |
9771b263 | 891 | FOR_EACH_VEC_ELT (datarefs, i, dr) |
bbc8a8dc | 892 | { |
5417e022 | 893 | ia = (unsigned) (size_t) dr->aux; |
bbc8a8dc ZD |
894 | ca = component_of (comp_father, ia); |
895 | if (ca == bad) | |
896 | continue; | |
897 | ||
898 | comp = comps[ca]; | |
899 | if (!comp) | |
900 | { | |
901 | comp = XCNEW (struct component); | |
9771b263 | 902 | comp->refs.create (comp_size[ca]); |
d9c259ef | 903 | comp->eliminate_store_p = eliminate_store_p; |
bbc8a8dc ZD |
904 | comps[ca] = comp; |
905 | } | |
906 | ||
99b1c316 | 907 | dataref = XCNEW (class dref_d); |
bbc8a8dc ZD |
908 | dataref->ref = dr; |
909 | dataref->stmt = DR_STMT (dr); | |
807e902e | 910 | dataref->offset = 0; |
bbc8a8dc ZD |
911 | dataref->distance = 0; |
912 | ||
913 | dataref->always_accessed | |
914 | = dominated_by_p (CDI_DOMINATORS, last_always_executed, | |
726a989a | 915 | gimple_bb (dataref->stmt)); |
9771b263 DN |
916 | dataref->pos = comp->refs.length (); |
917 | comp->refs.quick_push (dataref); | |
bbc8a8dc ZD |
918 | } |
919 | ||
6cedf5d8 RS |
920 | if (eliminate_store_p) |
921 | { | |
922 | bitmap_iterator bi; | |
923 | EXECUTE_IF_SET_IN_BITMAP (no_store_store_comps, 0, ia, bi) | |
924 | { | |
925 | ca = component_of (comp_father, ia); | |
926 | if (ca != bad) | |
927 | comps[ca]->eliminate_store_p = false; | |
928 | } | |
929 | } | |
930 | ||
bbc8a8dc ZD |
931 | for (i = 0; i < n; i++) |
932 | { | |
933 | comp = comps[i]; | |
934 | if (comp) | |
935 | { | |
936 | comp->next = comp_list; | |
937 | comp_list = comp; | |
938 | } | |
939 | } | |
940 | free (comps); | |
941 | ||
942 | end: | |
943 | free (comp_father); | |
944 | free (comp_size); | |
945 | return comp_list; | |
946 | } | |
947 | ||
948 | /* Returns true if the component COMP satisfies the conditions | |
c80b4100 | 949 | described in 2) at the beginning of this file. LOOP is the current |
bbc8a8dc | 950 | loop. */ |
b8698a0f | 951 | |
bbc8a8dc | 952 | static bool |
99b1c316 | 953 | suitable_component_p (class loop *loop, struct component *comp) |
bbc8a8dc ZD |
954 | { |
955 | unsigned i; | |
956 | dref a, first; | |
957 | basic_block ba, bp = loop->header; | |
958 | bool ok, has_write = false; | |
959 | ||
9771b263 | 960 | FOR_EACH_VEC_ELT (comp->refs, i, a) |
bbc8a8dc | 961 | { |
726a989a | 962 | ba = gimple_bb (a->stmt); |
bbc8a8dc ZD |
963 | |
964 | if (!just_once_each_iteration_p (loop, ba)) | |
965 | return false; | |
966 | ||
967 | gcc_assert (dominated_by_p (CDI_DOMINATORS, ba, bp)); | |
968 | bp = ba; | |
969 | ||
b0af49c4 | 970 | if (DR_IS_WRITE (a->ref)) |
bbc8a8dc ZD |
971 | has_write = true; |
972 | } | |
973 | ||
9771b263 | 974 | first = comp->refs[0]; |
bbc8a8dc ZD |
975 | ok = suitable_reference_p (first->ref, &comp->comp_step); |
976 | gcc_assert (ok); | |
807e902e | 977 | first->offset = 0; |
bbc8a8dc | 978 | |
9771b263 | 979 | for (i = 1; comp->refs.iterate (i, &a); i++) |
bbc8a8dc | 980 | { |
cc8bea09 RS |
981 | /* Polynomial offsets are no use, since we need to know the |
982 | gap between iteration numbers at compile time. */ | |
983 | poly_widest_int offset; | |
984 | if (!determine_offset (first->ref, a->ref, &offset) | |
985 | || !offset.is_constant (&a->offset)) | |
bbc8a8dc ZD |
986 | return false; |
987 | ||
b2b29377 MM |
988 | enum ref_step_type a_step; |
989 | gcc_checking_assert (suitable_reference_p (a->ref, &a_step) | |
990 | && a_step == comp->comp_step); | |
bbc8a8dc ZD |
991 | } |
992 | ||
993 | /* If there is a write inside the component, we must know whether the | |
994 | step is nonzero or not -- we would not otherwise be able to recognize | |
995 | whether the value accessed by reads comes from the OFFSET-th iteration | |
996 | or the previous one. */ | |
997 | if (has_write && comp->comp_step == RS_ANY) | |
998 | return false; | |
999 | ||
1000 | return true; | |
1001 | } | |
b8698a0f | 1002 | |
bbc8a8dc ZD |
1003 | /* Check the conditions on references inside each of components COMPS, |
1004 | and remove the unsuitable components from the list. The new list | |
1005 | of components is returned. The conditions are described in 2) at | |
c80b4100 | 1006 | the beginning of this file. LOOP is the current loop. */ |
bbc8a8dc ZD |
1007 | |
1008 | static struct component * | |
99b1c316 | 1009 | filter_suitable_components (class loop *loop, struct component *comps) |
bbc8a8dc ZD |
1010 | { |
1011 | struct component **comp, *act; | |
1012 | ||
1013 | for (comp = &comps; *comp; ) | |
1014 | { | |
1015 | act = *comp; | |
1016 | if (suitable_component_p (loop, act)) | |
1017 | comp = &act->next; | |
1018 | else | |
1019 | { | |
a0044be5 JJ |
1020 | dref ref; |
1021 | unsigned i; | |
1022 | ||
bbc8a8dc | 1023 | *comp = act->next; |
9771b263 | 1024 | FOR_EACH_VEC_ELT (act->refs, i, ref) |
a0044be5 | 1025 | free (ref); |
bbc8a8dc ZD |
1026 | release_component (act); |
1027 | } | |
1028 | } | |
1029 | ||
1030 | return comps; | |
1031 | } | |
1032 | ||
1033 | /* Compares two drefs A and B by their offset and position. Callback for | |
1034 | qsort. */ | |
1035 | ||
1036 | static int | |
1037 | order_drefs (const void *a, const void *b) | |
1038 | { | |
3d9a9f94 KG |
1039 | const dref *const da = (const dref *) a; |
1040 | const dref *const db = (const dref *) b; | |
807e902e | 1041 | int offcmp = wi::cmps ((*da)->offset, (*db)->offset); |
bbc8a8dc ZD |
1042 | |
1043 | if (offcmp != 0) | |
1044 | return offcmp; | |
1045 | ||
1046 | return (*da)->pos - (*db)->pos; | |
1047 | } | |
1048 | ||
bd9cc42b BC |
1049 | /* Compares two drefs A and B by their position. Callback for qsort. */ |
1050 | ||
1051 | static int | |
1052 | order_drefs_by_pos (const void *a, const void *b) | |
1053 | { | |
1054 | const dref *const da = (const dref *) a; | |
1055 | const dref *const db = (const dref *) b; | |
1056 | ||
1057 | return (*da)->pos - (*db)->pos; | |
1058 | } | |
1059 | ||
bbc8a8dc ZD |
1060 | /* Returns root of the CHAIN. */ |
1061 | ||
1062 | static inline dref | |
1063 | get_chain_root (chain_p chain) | |
1064 | { | |
9771b263 | 1065 | return chain->refs[0]; |
bbc8a8dc ZD |
1066 | } |
1067 | ||
9cdcebf9 | 1068 | /* Given CHAIN, returns the last write ref at DISTANCE, or NULL if it doesn't |
d9c259ef BC |
1069 | exist. */ |
1070 | ||
1071 | static inline dref | |
9cdcebf9 | 1072 | get_chain_last_write_at (chain_p chain, unsigned distance) |
d9c259ef | 1073 | { |
9cdcebf9 BC |
1074 | for (unsigned i = chain->refs.length (); i > 0; i--) |
1075 | if (DR_IS_WRITE (chain->refs[i - 1]->ref) | |
1076 | && distance == chain->refs[i - 1]->distance) | |
1077 | return chain->refs[i - 1]; | |
d9c259ef | 1078 | |
9cdcebf9 BC |
1079 | return NULL; |
1080 | } | |
1081 | ||
1082 | /* Given CHAIN, returns the last write ref with the same distance before load | |
1083 | at index LOAD_IDX, or NULL if it doesn't exist. */ | |
1084 | ||
1085 | static inline dref | |
1086 | get_chain_last_write_before_load (chain_p chain, unsigned load_idx) | |
1087 | { | |
1088 | gcc_assert (load_idx < chain->refs.length ()); | |
1089 | ||
1090 | unsigned distance = chain->refs[load_idx]->distance; | |
d9c259ef | 1091 | |
9cdcebf9 BC |
1092 | for (unsigned i = load_idx; i > 0; i--) |
1093 | if (DR_IS_WRITE (chain->refs[i - 1]->ref) | |
1094 | && distance == chain->refs[i - 1]->distance) | |
1095 | return chain->refs[i - 1]; | |
1096 | ||
1097 | return NULL; | |
d9c259ef BC |
1098 | } |
1099 | ||
bbc8a8dc ZD |
1100 | /* Adds REF to the chain CHAIN. */ |
1101 | ||
1102 | static void | |
1103 | add_ref_to_chain (chain_p chain, dref ref) | |
1104 | { | |
1105 | dref root = get_chain_root (chain); | |
bbc8a8dc | 1106 | |
807e902e KZ |
1107 | gcc_assert (wi::les_p (root->offset, ref->offset)); |
1108 | widest_int dist = ref->offset - root->offset; | |
807e902e | 1109 | gcc_assert (wi::fits_uhwi_p (dist)); |
bbc8a8dc | 1110 | |
9771b263 | 1111 | chain->refs.safe_push (ref); |
bbc8a8dc | 1112 | |
27bcd47c | 1113 | ref->distance = dist.to_uhwi (); |
bbc8a8dc ZD |
1114 | |
1115 | if (ref->distance >= chain->length) | |
1116 | { | |
1117 | chain->length = ref->distance; | |
1118 | chain->has_max_use_after = false; | |
1119 | } | |
1120 | ||
9cdcebf9 BC |
1121 | /* Promote this chain to CT_STORE_STORE if it has multiple stores. */ |
1122 | if (DR_IS_WRITE (ref->ref)) | |
1123 | chain->type = CT_STORE_STORE; | |
1124 | ||
39637a44 BC |
1125 | /* Don't set the flag for store-store chain since there is no use. */ |
1126 | if (chain->type != CT_STORE_STORE | |
1127 | && ref->distance == chain->length | |
bbc8a8dc ZD |
1128 | && ref->pos > root->pos) |
1129 | chain->has_max_use_after = true; | |
1130 | ||
1131 | chain->all_always_accessed &= ref->always_accessed; | |
1132 | } | |
1133 | ||
1134 | /* Returns the chain for invariant component COMP. */ | |
1135 | ||
1136 | static chain_p | |
1137 | make_invariant_chain (struct component *comp) | |
1138 | { | |
1139 | chain_p chain = XCNEW (struct chain); | |
1140 | unsigned i; | |
1141 | dref ref; | |
1142 | ||
1143 | chain->type = CT_INVARIANT; | |
1144 | ||
1145 | chain->all_always_accessed = true; | |
1146 | ||
9771b263 | 1147 | FOR_EACH_VEC_ELT (comp->refs, i, ref) |
bbc8a8dc | 1148 | { |
9771b263 | 1149 | chain->refs.safe_push (ref); |
bbc8a8dc ZD |
1150 | chain->all_always_accessed &= ref->always_accessed; |
1151 | } | |
1152 | ||
d9c259ef BC |
1153 | chain->inits = vNULL; |
1154 | chain->finis = vNULL; | |
1155 | ||
bbc8a8dc ZD |
1156 | return chain; |
1157 | } | |
1158 | ||
d9c259ef | 1159 | /* Make a new chain of type TYPE rooted at REF. */ |
bbc8a8dc ZD |
1160 | |
1161 | static chain_p | |
d9c259ef | 1162 | make_rooted_chain (dref ref, enum chain_type type) |
bbc8a8dc ZD |
1163 | { |
1164 | chain_p chain = XCNEW (struct chain); | |
1165 | ||
d9c259ef | 1166 | chain->type = type; |
9771b263 | 1167 | chain->refs.safe_push (ref); |
bbc8a8dc | 1168 | chain->all_always_accessed = ref->always_accessed; |
bbc8a8dc ZD |
1169 | ref->distance = 0; |
1170 | ||
d9c259ef BC |
1171 | chain->inits = vNULL; |
1172 | chain->finis = vNULL; | |
1173 | ||
bbc8a8dc ZD |
1174 | return chain; |
1175 | } | |
1176 | ||
1177 | /* Returns true if CHAIN is not trivial. */ | |
1178 | ||
1179 | static bool | |
1180 | nontrivial_chain_p (chain_p chain) | |
1181 | { | |
9771b263 | 1182 | return chain != NULL && chain->refs.length () > 1; |
bbc8a8dc ZD |
1183 | } |
1184 | ||
1185 | /* Returns the ssa name that contains the value of REF, or NULL_TREE if there | |
1186 | is no such name. */ | |
1187 | ||
1188 | static tree | |
1189 | name_for_ref (dref ref) | |
1190 | { | |
1191 | tree name; | |
1192 | ||
726a989a | 1193 | if (is_gimple_assign (ref->stmt)) |
bbc8a8dc ZD |
1194 | { |
1195 | if (!ref->ref || DR_IS_READ (ref->ref)) | |
726a989a | 1196 | name = gimple_assign_lhs (ref->stmt); |
bbc8a8dc | 1197 | else |
726a989a | 1198 | name = gimple_assign_rhs1 (ref->stmt); |
bbc8a8dc ZD |
1199 | } |
1200 | else | |
1201 | name = PHI_RESULT (ref->stmt); | |
1202 | ||
1203 | return (TREE_CODE (name) == SSA_NAME ? name : NULL_TREE); | |
1204 | } | |
1205 | ||
1206 | /* Returns true if REF is a valid initializer for ROOT with given DISTANCE (in | |
1207 | iterations of the innermost enclosing loop). */ | |
1208 | ||
1209 | static bool | |
1210 | valid_initializer_p (struct data_reference *ref, | |
1211 | unsigned distance, struct data_reference *root) | |
1212 | { | |
1213 | aff_tree diff, base, step; | |
cc8bea09 | 1214 | poly_widest_int off; |
bbc8a8dc | 1215 | |
bbc8a8dc ZD |
1216 | /* Both REF and ROOT must be accessing the same object. */ |
1217 | if (!operand_equal_p (DR_BASE_ADDRESS (ref), DR_BASE_ADDRESS (root), 0)) | |
1218 | return false; | |
1219 | ||
1220 | /* The initializer is defined outside of loop, hence its address must be | |
1221 | invariant inside the loop. */ | |
1222 | gcc_assert (integer_zerop (DR_STEP (ref))); | |
1223 | ||
1224 | /* If the address of the reference is invariant, initializer must access | |
1225 | exactly the same location. */ | |
1226 | if (integer_zerop (DR_STEP (root))) | |
1227 | return (operand_equal_p (DR_OFFSET (ref), DR_OFFSET (root), 0) | |
1228 | && operand_equal_p (DR_INIT (ref), DR_INIT (root), 0)); | |
1229 | ||
1230 | /* Verify that this index of REF is equal to the root's index at | |
1231 | -DISTANCE-th iteration. */ | |
1232 | aff_combination_dr_offset (root, &diff); | |
1233 | aff_combination_dr_offset (ref, &base); | |
807e902e | 1234 | aff_combination_scale (&base, -1); |
bbc8a8dc ZD |
1235 | aff_combination_add (&diff, &base); |
1236 | ||
0d82a1c8 RG |
1237 | tree_to_aff_combination_expand (DR_STEP (root), TREE_TYPE (DR_STEP (root)), |
1238 | &step, &name_expansions); | |
bbc8a8dc ZD |
1239 | if (!aff_combination_constant_multiple_p (&diff, &step, &off)) |
1240 | return false; | |
1241 | ||
cc8bea09 | 1242 | if (maybe_ne (off, distance)) |
bbc8a8dc ZD |
1243 | return false; |
1244 | ||
1245 | return true; | |
1246 | } | |
1247 | ||
1248 | /* Finds looparound phi node of LOOP that copies the value of REF, and if its | |
1249 | initial value is correct (equal to initial value of REF shifted by one | |
1250 | iteration), returns the phi node. Otherwise, NULL_TREE is returned. ROOT | |
1251 | is the root of the current chain. */ | |
1252 | ||
538dd0b7 | 1253 | static gphi * |
99b1c316 | 1254 | find_looparound_phi (class loop *loop, dref ref, dref root) |
bbc8a8dc | 1255 | { |
726a989a | 1256 | tree name, init, init_ref; |
538dd0b7 | 1257 | gphi *phi = NULL; |
355fe088 | 1258 | gimple *init_stmt; |
bbc8a8dc ZD |
1259 | edge latch = loop_latch_edge (loop); |
1260 | struct data_reference init_dr; | |
538dd0b7 | 1261 | gphi_iterator psi; |
bbc8a8dc | 1262 | |
726a989a | 1263 | if (is_gimple_assign (ref->stmt)) |
bbc8a8dc ZD |
1264 | { |
1265 | if (DR_IS_READ (ref->ref)) | |
726a989a | 1266 | name = gimple_assign_lhs (ref->stmt); |
bbc8a8dc | 1267 | else |
726a989a | 1268 | name = gimple_assign_rhs1 (ref->stmt); |
bbc8a8dc ZD |
1269 | } |
1270 | else | |
1271 | name = PHI_RESULT (ref->stmt); | |
1272 | if (!name) | |
726a989a | 1273 | return NULL; |
bbc8a8dc | 1274 | |
726a989a RB |
1275 | for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi)) |
1276 | { | |
538dd0b7 | 1277 | phi = psi.phi (); |
726a989a RB |
1278 | if (PHI_ARG_DEF_FROM_EDGE (phi, latch) == name) |
1279 | break; | |
1280 | } | |
bbc8a8dc | 1281 | |
726a989a RB |
1282 | if (gsi_end_p (psi)) |
1283 | return NULL; | |
bbc8a8dc ZD |
1284 | |
1285 | init = PHI_ARG_DEF_FROM_EDGE (phi, loop_preheader_edge (loop)); | |
1286 | if (TREE_CODE (init) != SSA_NAME) | |
726a989a | 1287 | return NULL; |
bbc8a8dc | 1288 | init_stmt = SSA_NAME_DEF_STMT (init); |
726a989a RB |
1289 | if (gimple_code (init_stmt) != GIMPLE_ASSIGN) |
1290 | return NULL; | |
1291 | gcc_assert (gimple_assign_lhs (init_stmt) == init); | |
bbc8a8dc | 1292 | |
726a989a | 1293 | init_ref = gimple_assign_rhs1 (init_stmt); |
bbc8a8dc ZD |
1294 | if (!REFERENCE_CLASS_P (init_ref) |
1295 | && !DECL_P (init_ref)) | |
726a989a | 1296 | return NULL; |
bbc8a8dc ZD |
1297 | |
1298 | /* Analyze the behavior of INIT_REF with respect to LOOP (innermost | |
1299 | loop enclosing PHI). */ | |
1300 | memset (&init_dr, 0, sizeof (struct data_reference)); | |
1301 | DR_REF (&init_dr) = init_ref; | |
1302 | DR_STMT (&init_dr) = phi; | |
f4ebbd24 DM |
1303 | if (!dr_analyze_innermost (&DR_INNERMOST (&init_dr), init_ref, loop, |
1304 | init_stmt)) | |
3661e899 | 1305 | return NULL; |
bbc8a8dc ZD |
1306 | |
1307 | if (!valid_initializer_p (&init_dr, ref->distance + 1, root->ref)) | |
726a989a | 1308 | return NULL; |
bbc8a8dc ZD |
1309 | |
1310 | return phi; | |
1311 | } | |
1312 | ||
1313 | /* Adds a reference for the looparound copy of REF in PHI to CHAIN. */ | |
1314 | ||
1315 | static void | |
538dd0b7 | 1316 | insert_looparound_copy (chain_p chain, dref ref, gphi *phi) |
bbc8a8dc | 1317 | { |
99b1c316 | 1318 | dref nw = XCNEW (class dref_d), aref; |
bbc8a8dc ZD |
1319 | unsigned i; |
1320 | ||
1321 | nw->stmt = phi; | |
1322 | nw->distance = ref->distance + 1; | |
1323 | nw->always_accessed = 1; | |
1324 | ||
9771b263 | 1325 | FOR_EACH_VEC_ELT (chain->refs, i, aref) |
bbc8a8dc ZD |
1326 | if (aref->distance >= nw->distance) |
1327 | break; | |
9771b263 | 1328 | chain->refs.safe_insert (i, nw); |
bbc8a8dc ZD |
1329 | |
1330 | if (nw->distance > chain->length) | |
1331 | { | |
1332 | chain->length = nw->distance; | |
1333 | chain->has_max_use_after = false; | |
1334 | } | |
1335 | } | |
1336 | ||
1337 | /* For references in CHAIN that are copied around the LOOP (created previously | |
1338 | by PRE, or by user), add the results of such copies to the chain. This | |
1339 | enables us to remove the copies by unrolling, and may need less registers | |
1340 | (also, it may allow us to combine chains together). */ | |
1341 | ||
1342 | static void | |
99b1c316 | 1343 | add_looparound_copies (class loop *loop, chain_p chain) |
bbc8a8dc ZD |
1344 | { |
1345 | unsigned i; | |
1346 | dref ref, root = get_chain_root (chain); | |
538dd0b7 | 1347 | gphi *phi; |
bbc8a8dc | 1348 | |
d9c259ef BC |
1349 | if (chain->type == CT_STORE_STORE) |
1350 | return; | |
1351 | ||
9771b263 | 1352 | FOR_EACH_VEC_ELT (chain->refs, i, ref) |
bbc8a8dc ZD |
1353 | { |
1354 | phi = find_looparound_phi (loop, ref, root); | |
1355 | if (!phi) | |
1356 | continue; | |
1357 | ||
1358 | bitmap_set_bit (looparound_phis, SSA_NAME_VERSION (PHI_RESULT (phi))); | |
1359 | insert_looparound_copy (chain, ref, phi); | |
1360 | } | |
1361 | } | |
1362 | ||
1363 | /* Find roots of the values and determine distances in the component COMP. | |
1364 | The references are redistributed into CHAINS. LOOP is the current | |
1365 | loop. */ | |
1366 | ||
1367 | static void | |
99b1c316 | 1368 | determine_roots_comp (class loop *loop, |
bbc8a8dc | 1369 | struct component *comp, |
9771b263 | 1370 | vec<chain_p> *chains) |
bbc8a8dc ZD |
1371 | { |
1372 | unsigned i; | |
1373 | dref a; | |
1374 | chain_p chain = NULL; | |
807e902e | 1375 | widest_int last_ofs = 0; |
d9c259ef | 1376 | enum chain_type type; |
bbc8a8dc ZD |
1377 | |
1378 | /* Invariants are handled specially. */ | |
1379 | if (comp->comp_step == RS_INVARIANT) | |
1380 | { | |
1381 | chain = make_invariant_chain (comp); | |
9771b263 | 1382 | chains->safe_push (chain); |
bbc8a8dc ZD |
1383 | return; |
1384 | } | |
1385 | ||
67bb451d BC |
1386 | /* Trivial component. */ |
1387 | if (comp->refs.length () <= 1) | |
df3c2945 BC |
1388 | { |
1389 | if (comp->refs.length () == 1) | |
1390 | { | |
1391 | free (comp->refs[0]); | |
1392 | comp->refs.truncate (0); | |
1393 | } | |
1394 | return; | |
1395 | } | |
bbc8a8dc | 1396 | |
67bb451d | 1397 | comp->refs.qsort (order_drefs); |
9cdcebf9 BC |
1398 | |
1399 | /* For Store-Store chain, we only support load if it is dominated by a | |
1400 | store statement in the same iteration of loop. */ | |
1401 | if (comp->eliminate_store_p) | |
1402 | for (a = NULL, i = 0; i < comp->refs.length (); i++) | |
1403 | { | |
1404 | if (DR_IS_WRITE (comp->refs[i]->ref)) | |
1405 | a = comp->refs[i]; | |
1406 | else if (a == NULL || a->offset != comp->refs[i]->offset) | |
1407 | { | |
1408 | /* If there is load that is not dominated by a store in the | |
1409 | same iteration of loop, clear the flag so no Store-Store | |
1410 | chain is generated for this component. */ | |
1411 | comp->eliminate_store_p = false; | |
1412 | break; | |
1413 | } | |
1414 | } | |
1415 | ||
1416 | /* Determine roots and create chains for components. */ | |
9771b263 | 1417 | FOR_EACH_VEC_ELT (comp->refs, i, a) |
bbc8a8dc | 1418 | { |
d9c259ef | 1419 | if (!chain |
9cdcebf9 | 1420 | || (chain->type == CT_LOAD && DR_IS_WRITE (a->ref)) |
d9c259ef | 1421 | || (!comp->eliminate_store_p && DR_IS_WRITE (a->ref)) |
807e902e | 1422 | || wi::leu_p (MAX_DISTANCE, a->offset - last_ofs)) |
bbc8a8dc ZD |
1423 | { |
1424 | if (nontrivial_chain_p (chain)) | |
b61b1f17 MM |
1425 | { |
1426 | add_looparound_copies (loop, chain); | |
9771b263 | 1427 | chains->safe_push (chain); |
b61b1f17 | 1428 | } |
bbc8a8dc ZD |
1429 | else |
1430 | release_chain (chain); | |
d9c259ef | 1431 | |
9cdcebf9 BC |
1432 | /* Determine type of the chain. If the root reference is a load, |
1433 | this can only be a CT_LOAD chain; other chains are intialized | |
1434 | to CT_STORE_LOAD and might be promoted to CT_STORE_STORE when | |
1435 | new reference is added. */ | |
1436 | type = DR_IS_READ (a->ref) ? CT_LOAD : CT_STORE_LOAD; | |
d9c259ef | 1437 | chain = make_rooted_chain (a, type); |
b61b1f17 | 1438 | last_ofs = a->offset; |
bbc8a8dc ZD |
1439 | continue; |
1440 | } | |
1441 | ||
1442 | add_ref_to_chain (chain, a); | |
1443 | } | |
1444 | ||
1445 | if (nontrivial_chain_p (chain)) | |
1446 | { | |
1447 | add_looparound_copies (loop, chain); | |
9771b263 | 1448 | chains->safe_push (chain); |
bbc8a8dc ZD |
1449 | } |
1450 | else | |
1451 | release_chain (chain); | |
1452 | } | |
1453 | ||
1454 | /* Find roots of the values and determine distances in components COMPS, and | |
1455 | separates the references to CHAINS. LOOP is the current loop. */ | |
1456 | ||
1457 | static void | |
99b1c316 | 1458 | determine_roots (class loop *loop, |
9771b263 | 1459 | struct component *comps, vec<chain_p> *chains) |
bbc8a8dc ZD |
1460 | { |
1461 | struct component *comp; | |
1462 | ||
1463 | for (comp = comps; comp; comp = comp->next) | |
1464 | determine_roots_comp (loop, comp, chains); | |
1465 | } | |
1466 | ||
1467 | /* Replace the reference in statement STMT with temporary variable | |
82d6e6fc | 1468 | NEW_TREE. If SET is true, NEW_TREE is instead initialized to the value of |
bbc8a8dc ZD |
1469 | the reference in the statement. IN_LHS is true if the reference |
1470 | is in the lhs of STMT, false if it is in rhs. */ | |
1471 | ||
1472 | static void | |
355fe088 | 1473 | replace_ref_with (gimple *stmt, tree new_tree, bool set, bool in_lhs) |
bbc8a8dc | 1474 | { |
726a989a | 1475 | tree val; |
538dd0b7 | 1476 | gassign *new_stmt; |
726a989a | 1477 | gimple_stmt_iterator bsi, psi; |
bbc8a8dc | 1478 | |
726a989a | 1479 | if (gimple_code (stmt) == GIMPLE_PHI) |
bbc8a8dc ZD |
1480 | { |
1481 | gcc_assert (!in_lhs && !set); | |
1482 | ||
1483 | val = PHI_RESULT (stmt); | |
726a989a RB |
1484 | bsi = gsi_after_labels (gimple_bb (stmt)); |
1485 | psi = gsi_for_stmt (stmt); | |
1486 | remove_phi_node (&psi, false); | |
bbc8a8dc | 1487 | |
726a989a | 1488 | /* Turn the phi node into GIMPLE_ASSIGN. */ |
82d6e6fc | 1489 | new_stmt = gimple_build_assign (val, new_tree); |
726a989a | 1490 | gsi_insert_before (&bsi, new_stmt, GSI_NEW_STMT); |
bbc8a8dc ZD |
1491 | return; |
1492 | } | |
b8698a0f | 1493 | |
bbc8a8dc ZD |
1494 | /* Since the reference is of gimple_reg type, it should only |
1495 | appear as lhs or rhs of modify statement. */ | |
726a989a RB |
1496 | gcc_assert (is_gimple_assign (stmt)); |
1497 | ||
1498 | bsi = gsi_for_stmt (stmt); | |
bbc8a8dc | 1499 | |
82d6e6fc | 1500 | /* If we do not need to initialize NEW_TREE, just replace the use of OLD. */ |
bbc8a8dc ZD |
1501 | if (!set) |
1502 | { | |
1503 | gcc_assert (!in_lhs); | |
82d6e6fc | 1504 | gimple_assign_set_rhs_from_tree (&bsi, new_tree); |
726a989a | 1505 | stmt = gsi_stmt (bsi); |
bbc8a8dc ZD |
1506 | update_stmt (stmt); |
1507 | return; | |
1508 | } | |
1509 | ||
bbc8a8dc ZD |
1510 | if (in_lhs) |
1511 | { | |
726a989a | 1512 | /* We have statement |
b8698a0f | 1513 | |
726a989a | 1514 | OLD = VAL |
bbc8a8dc | 1515 | |
726a989a RB |
1516 | If OLD is a memory reference, then VAL is gimple_val, and we transform |
1517 | this to | |
bbc8a8dc ZD |
1518 | |
1519 | OLD = VAL | |
1520 | NEW = VAL | |
1521 | ||
b8698a0f | 1522 | Otherwise, we are replacing a combination chain, |
726a989a RB |
1523 | VAL is the expression that performs the combination, and OLD is an |
1524 | SSA name. In this case, we transform the assignment to | |
1525 | ||
1526 | OLD = VAL | |
1527 | NEW = OLD | |
1528 | ||
1529 | */ | |
1530 | ||
1531 | val = gimple_assign_lhs (stmt); | |
1532 | if (TREE_CODE (val) != SSA_NAME) | |
1533 | { | |
726a989a | 1534 | val = gimple_assign_rhs1 (stmt); |
7e8b1c4b JJ |
1535 | gcc_assert (gimple_assign_single_p (stmt)); |
1536 | if (TREE_CLOBBER_P (val)) | |
32244553 | 1537 | val = get_or_create_ssa_default_def (cfun, SSA_NAME_VAR (new_tree)); |
7e8b1c4b JJ |
1538 | else |
1539 | gcc_assert (gimple_assign_copy_p (stmt)); | |
726a989a | 1540 | } |
bbc8a8dc ZD |
1541 | } |
1542 | else | |
1543 | { | |
bbc8a8dc ZD |
1544 | /* VAL = OLD |
1545 | ||
1546 | is transformed to | |
1547 | ||
1548 | VAL = OLD | |
1549 | NEW = VAL */ | |
726a989a RB |
1550 | |
1551 | val = gimple_assign_lhs (stmt); | |
bbc8a8dc ZD |
1552 | } |
1553 | ||
82d6e6fc | 1554 | new_stmt = gimple_build_assign (new_tree, unshare_expr (val)); |
726a989a | 1555 | gsi_insert_after (&bsi, new_stmt, GSI_NEW_STMT); |
bbc8a8dc ZD |
1556 | } |
1557 | ||
3c62a7fb BC |
1558 | /* Returns a memory reference to DR in the (NITERS + ITER)-th iteration |
1559 | of the loop it was analyzed in. Append init stmts to STMTS. */ | |
9f2b860b | 1560 | |
b1ad9be2 | 1561 | static tree |
3c62a7fb BC |
1562 | ref_at_iteration (data_reference_p dr, int iter, |
1563 | gimple_seq *stmts, tree niters = NULL_TREE) | |
9f2b860b RB |
1564 | { |
1565 | tree off = DR_OFFSET (dr); | |
1566 | tree coff = DR_INIT (dr); | |
b1ad9be2 BE |
1567 | tree ref = DR_REF (dr); |
1568 | enum tree_code ref_code = ERROR_MARK; | |
1569 | tree ref_type = NULL_TREE; | |
1570 | tree ref_op1 = NULL_TREE; | |
1571 | tree ref_op2 = NULL_TREE; | |
3c62a7fb BC |
1572 | tree new_offset; |
1573 | ||
1574 | if (iter != 0) | |
1575 | { | |
1576 | new_offset = size_binop (MULT_EXPR, DR_STEP (dr), ssize_int (iter)); | |
1577 | if (TREE_CODE (new_offset) == INTEGER_CST) | |
1578 | coff = size_binop (PLUS_EXPR, coff, new_offset); | |
1579 | else | |
1580 | off = size_binop (PLUS_EXPR, off, new_offset); | |
1581 | } | |
1582 | ||
1583 | if (niters != NULL_TREE) | |
1584 | { | |
1585 | niters = fold_convert (ssizetype, niters); | |
1586 | new_offset = size_binop (MULT_EXPR, DR_STEP (dr), niters); | |
1587 | if (TREE_CODE (niters) == INTEGER_CST) | |
1588 | coff = size_binop (PLUS_EXPR, coff, new_offset); | |
1589 | else | |
1590 | off = size_binop (PLUS_EXPR, off, new_offset); | |
1591 | } | |
1592 | ||
cb3d1e3e RB |
1593 | /* While data-ref analysis punts on bit offsets it still handles |
1594 | bitfield accesses at byte boundaries. Cope with that. Note that | |
b1ad9be2 BE |
1595 | if the bitfield object also starts at a byte-boundary we can simply |
1596 | replicate the COMPONENT_REF, but we have to subtract the component's | |
1597 | byte-offset from the MEM_REF address first. | |
1598 | Otherwise we simply build a BIT_FIELD_REF knowing that the bits | |
cb3d1e3e | 1599 | start at offset zero. */ |
b1ad9be2 BE |
1600 | if (TREE_CODE (ref) == COMPONENT_REF |
1601 | && DECL_BIT_FIELD (TREE_OPERAND (ref, 1))) | |
cb3d1e3e | 1602 | { |
b1ad9be2 BE |
1603 | unsigned HOST_WIDE_INT boff; |
1604 | tree field = TREE_OPERAND (ref, 1); | |
1605 | tree offset = component_ref_field_offset (ref); | |
1606 | ref_type = TREE_TYPE (ref); | |
1607 | boff = tree_to_uhwi (DECL_FIELD_BIT_OFFSET (field)); | |
1608 | /* This can occur in Ada. See the comment in get_bit_range. */ | |
1609 | if (boff % BITS_PER_UNIT != 0 | |
1610 | || !tree_fits_uhwi_p (offset)) | |
1611 | { | |
1612 | ref_code = BIT_FIELD_REF; | |
1613 | ref_op1 = DECL_SIZE (field); | |
1614 | ref_op2 = bitsize_zero_node; | |
1615 | } | |
1616 | else | |
1617 | { | |
1618 | boff >>= LOG2_BITS_PER_UNIT; | |
1619 | boff += tree_to_uhwi (offset); | |
1620 | coff = size_binop (MINUS_EXPR, coff, ssize_int (boff)); | |
1621 | ref_code = COMPONENT_REF; | |
1622 | ref_op1 = field; | |
1623 | ref_op2 = TREE_OPERAND (ref, 2); | |
1624 | ref = TREE_OPERAND (ref, 0); | |
1625 | } | |
cb3d1e3e | 1626 | } |
b1ad9be2 BE |
1627 | tree addr = fold_build_pointer_plus (DR_BASE_ADDRESS (dr), off); |
1628 | addr = force_gimple_operand_1 (unshare_expr (addr), stmts, | |
1629 | is_gimple_mem_ref_addr, NULL_TREE); | |
1630 | tree alias_ptr = fold_convert (reference_alias_ptr_type (ref), coff); | |
1631 | tree type = build_aligned_type (TREE_TYPE (ref), | |
1632 | get_object_alignment (ref)); | |
1633 | ref = build2 (MEM_REF, type, addr, alias_ptr); | |
1634 | if (ref_type) | |
1635 | ref = build3 (ref_code, ref_type, ref, ref_op1, ref_op2); | |
1636 | return ref; | |
bbc8a8dc ZD |
1637 | } |
1638 | ||
1639 | /* Get the initialization expression for the INDEX-th temporary variable | |
1640 | of CHAIN. */ | |
1641 | ||
1642 | static tree | |
1643 | get_init_expr (chain_p chain, unsigned index) | |
1644 | { | |
1645 | if (chain->type == CT_COMBINATION) | |
1646 | { | |
1647 | tree e1 = get_init_expr (chain->ch1, index); | |
1648 | tree e2 = get_init_expr (chain->ch2, index); | |
1649 | ||
82d6e6fc | 1650 | return fold_build2 (chain->op, chain->rslt_type, e1, e2); |
bbc8a8dc ZD |
1651 | } |
1652 | else | |
9771b263 | 1653 | return chain->inits[index]; |
bbc8a8dc ZD |
1654 | } |
1655 | ||
2664efb6 ZD |
1656 | /* Returns a new temporary variable used for the I-th variable carrying |
1657 | value of REF. The variable's uid is marked in TMP_VARS. */ | |
1658 | ||
1659 | static tree | |
1660 | predcom_tmp_var (tree ref, unsigned i, bitmap tmp_vars) | |
1661 | { | |
1662 | tree type = TREE_TYPE (ref); | |
2664efb6 ZD |
1663 | /* We never access the components of the temporary variable in predictive |
1664 | commoning. */ | |
acd63801 | 1665 | tree var = create_tmp_reg (type, get_lsm_tmp_name (ref, i)); |
2664efb6 ZD |
1666 | bitmap_set_bit (tmp_vars, DECL_UID (var)); |
1667 | return var; | |
1668 | } | |
1669 | ||
bbc8a8dc ZD |
1670 | /* Creates the variables for CHAIN, as well as phi nodes for them and |
1671 | initialization on entry to LOOP. Uids of the newly created | |
1672 | temporary variables are marked in TMP_VARS. */ | |
1673 | ||
1674 | static void | |
99b1c316 | 1675 | initialize_root_vars (class loop *loop, chain_p chain, bitmap tmp_vars) |
bbc8a8dc ZD |
1676 | { |
1677 | unsigned i; | |
1678 | unsigned n = chain->length; | |
1679 | dref root = get_chain_root (chain); | |
1680 | bool reuse_first = !chain->has_max_use_after; | |
726a989a | 1681 | tree ref, init, var, next; |
538dd0b7 | 1682 | gphi *phi; |
726a989a | 1683 | gimple_seq stmts; |
bbc8a8dc ZD |
1684 | edge entry = loop_preheader_edge (loop), latch = loop_latch_edge (loop); |
1685 | ||
1686 | /* If N == 0, then all the references are within the single iteration. And | |
1687 | since this is an nonempty chain, reuse_first cannot be true. */ | |
1688 | gcc_assert (n > 0 || !reuse_first); | |
1689 | ||
9771b263 | 1690 | chain->vars.create (n + 1); |
bbc8a8dc ZD |
1691 | |
1692 | if (chain->type == CT_COMBINATION) | |
726a989a | 1693 | ref = gimple_assign_lhs (root->stmt); |
bbc8a8dc ZD |
1694 | else |
1695 | ref = DR_REF (root->ref); | |
1696 | ||
1697 | for (i = 0; i < n + (reuse_first ? 0 : 1); i++) | |
1698 | { | |
2664efb6 | 1699 | var = predcom_tmp_var (ref, i, tmp_vars); |
9771b263 | 1700 | chain->vars.quick_push (var); |
bbc8a8dc ZD |
1701 | } |
1702 | if (reuse_first) | |
9771b263 | 1703 | chain->vars.quick_push (chain->vars[0]); |
b8698a0f | 1704 | |
9771b263 | 1705 | FOR_EACH_VEC_ELT (chain->vars, i, var) |
b731b390 | 1706 | chain->vars[i] = make_ssa_name (var); |
bbc8a8dc ZD |
1707 | |
1708 | for (i = 0; i < n; i++) | |
1709 | { | |
9771b263 DN |
1710 | var = chain->vars[i]; |
1711 | next = chain->vars[i + 1]; | |
bbc8a8dc ZD |
1712 | init = get_init_expr (chain, i); |
1713 | ||
1714 | init = force_gimple_operand (init, &stmts, true, NULL_TREE); | |
1715 | if (stmts) | |
5006671f | 1716 | gsi_insert_seq_on_edge_immediate (entry, stmts); |
bbc8a8dc ZD |
1717 | |
1718 | phi = create_phi_node (var, loop->header); | |
9e227d60 DC |
1719 | add_phi_arg (phi, init, entry, UNKNOWN_LOCATION); |
1720 | add_phi_arg (phi, next, latch, UNKNOWN_LOCATION); | |
bbc8a8dc ZD |
1721 | } |
1722 | } | |
1723 | ||
39ff50ce BC |
1724 | /* For inter-iteration store elimination CHAIN in LOOP, returns true if |
1725 | all stores to be eliminated store loop invariant values into memory. | |
1726 | In this case, we can use these invariant values directly after LOOP. */ | |
1727 | ||
1728 | static bool | |
99b1c316 | 1729 | is_inv_store_elimination_chain (class loop *loop, chain_p chain) |
39ff50ce BC |
1730 | { |
1731 | if (chain->length == 0 || chain->type != CT_STORE_STORE) | |
1732 | return false; | |
1733 | ||
1734 | gcc_assert (!chain->has_max_use_after); | |
1735 | ||
02fac244 | 1736 | /* If loop iterates for unknown times or fewer times than chain->length, |
39ff50ce BC |
1737 | we still need to setup root variable and propagate it with PHI node. */ |
1738 | tree niters = number_of_latch_executions (loop); | |
8e6cdc90 RS |
1739 | if (TREE_CODE (niters) != INTEGER_CST |
1740 | || wi::leu_p (wi::to_wide (niters), chain->length)) | |
39ff50ce BC |
1741 | return false; |
1742 | ||
1743 | /* Check stores in chain for elimination if they only store loop invariant | |
1744 | values. */ | |
1745 | for (unsigned i = 0; i < chain->length; i++) | |
1746 | { | |
9cdcebf9 | 1747 | dref a = get_chain_last_write_at (chain, i); |
39ff50ce BC |
1748 | if (a == NULL) |
1749 | continue; | |
1750 | ||
1751 | gimple *def_stmt, *stmt = a->stmt; | |
1752 | if (!gimple_assign_single_p (stmt)) | |
1753 | return false; | |
1754 | ||
1755 | tree val = gimple_assign_rhs1 (stmt); | |
1756 | if (TREE_CLOBBER_P (val)) | |
1757 | return false; | |
1758 | ||
1759 | if (CONSTANT_CLASS_P (val)) | |
1760 | continue; | |
1761 | ||
1762 | if (TREE_CODE (val) != SSA_NAME) | |
1763 | return false; | |
1764 | ||
1765 | def_stmt = SSA_NAME_DEF_STMT (val); | |
1766 | if (gimple_nop_p (def_stmt)) | |
1767 | continue; | |
1768 | ||
1769 | if (flow_bb_inside_loop_p (loop, gimple_bb (def_stmt))) | |
1770 | return false; | |
1771 | } | |
1772 | return true; | |
1773 | } | |
1774 | ||
1775 | /* Creates root variables for store elimination CHAIN in which stores for | |
1776 | elimination only store loop invariant values. In this case, we neither | |
1777 | need to load root variables before loop nor propagate it with PHI nodes. */ | |
1778 | ||
1779 | static void | |
1780 | initialize_root_vars_store_elim_1 (chain_p chain) | |
1781 | { | |
1782 | tree var; | |
1783 | unsigned i, n = chain->length; | |
1784 | ||
1785 | chain->vars.create (n); | |
1786 | chain->vars.safe_grow_cleared (n); | |
1787 | ||
1788 | /* Initialize root value for eliminated stores at each distance. */ | |
1789 | for (i = 0; i < n; i++) | |
1790 | { | |
9cdcebf9 | 1791 | dref a = get_chain_last_write_at (chain, i); |
39ff50ce BC |
1792 | if (a == NULL) |
1793 | continue; | |
1794 | ||
1795 | var = gimple_assign_rhs1 (a->stmt); | |
1796 | chain->vars[a->distance] = var; | |
1797 | } | |
1798 | ||
1799 | /* We don't propagate values with PHI nodes, so manually propagate value | |
1800 | to bubble positions. */ | |
1801 | var = chain->vars[0]; | |
1802 | for (i = 1; i < n; i++) | |
1803 | { | |
1804 | if (chain->vars[i] != NULL_TREE) | |
1805 | { | |
1806 | var = chain->vars[i]; | |
1807 | continue; | |
1808 | } | |
1809 | chain->vars[i] = var; | |
1810 | } | |
1811 | ||
1812 | /* Revert the vector. */ | |
1813 | for (i = 0; i < n / 2; i++) | |
1814 | std::swap (chain->vars[i], chain->vars[n - i - 1]); | |
1815 | } | |
1816 | ||
d9c259ef BC |
1817 | /* Creates root variables for store elimination CHAIN in which stores for |
1818 | elimination store loop variant values. In this case, we may need to | |
1819 | load root variables before LOOP and propagate it with PHI nodes. Uids | |
1820 | of the newly created root variables are marked in TMP_VARS. */ | |
1821 | ||
1822 | static void | |
99b1c316 | 1823 | initialize_root_vars_store_elim_2 (class loop *loop, |
d9c259ef BC |
1824 | chain_p chain, bitmap tmp_vars) |
1825 | { | |
1826 | unsigned i, n = chain->length; | |
1827 | tree ref, init, var, next, val, phi_result; | |
1828 | gimple *stmt; | |
1829 | gimple_seq stmts; | |
1830 | ||
1831 | chain->vars.create (n); | |
1832 | ||
1833 | ref = DR_REF (get_chain_root (chain)->ref); | |
1834 | for (i = 0; i < n; i++) | |
1835 | { | |
1836 | var = predcom_tmp_var (ref, i, tmp_vars); | |
1837 | chain->vars.quick_push (var); | |
1838 | } | |
1839 | ||
1840 | FOR_EACH_VEC_ELT (chain->vars, i, var) | |
1841 | chain->vars[i] = make_ssa_name (var); | |
1842 | ||
1843 | /* Root values are either rhs operand of stores to be eliminated, or | |
1844 | loaded from memory before loop. */ | |
1845 | auto_vec<tree> vtemps; | |
1846 | vtemps.safe_grow_cleared (n); | |
1847 | for (i = 0; i < n; i++) | |
1848 | { | |
1849 | init = get_init_expr (chain, i); | |
1850 | if (init == NULL_TREE) | |
1851 | { | |
1852 | /* Root value is rhs operand of the store to be eliminated if | |
1853 | it isn't loaded from memory before loop. */ | |
9cdcebf9 | 1854 | dref a = get_chain_last_write_at (chain, i); |
d9c259ef BC |
1855 | val = gimple_assign_rhs1 (a->stmt); |
1856 | if (TREE_CLOBBER_P (val)) | |
9cdcebf9 BC |
1857 | { |
1858 | val = get_or_create_ssa_default_def (cfun, SSA_NAME_VAR (var)); | |
1859 | gimple_assign_set_rhs1 (a->stmt, val); | |
1860 | } | |
d9c259ef BC |
1861 | |
1862 | vtemps[n - i - 1] = val; | |
1863 | } | |
1864 | else | |
1865 | { | |
1866 | edge latch = loop_latch_edge (loop); | |
1867 | edge entry = loop_preheader_edge (loop); | |
1868 | ||
1869 | /* Root value is loaded from memory before loop, we also need | |
1870 | to add PHI nodes to propagate the value across iterations. */ | |
1871 | init = force_gimple_operand (init, &stmts, true, NULL_TREE); | |
1872 | if (stmts) | |
1873 | gsi_insert_seq_on_edge_immediate (entry, stmts); | |
1874 | ||
1875 | next = chain->vars[n - i]; | |
1876 | phi_result = copy_ssa_name (next); | |
1877 | gphi *phi = create_phi_node (phi_result, loop->header); | |
1878 | add_phi_arg (phi, init, entry, UNKNOWN_LOCATION); | |
1879 | add_phi_arg (phi, next, latch, UNKNOWN_LOCATION); | |
1880 | vtemps[n - i - 1] = phi_result; | |
1881 | } | |
1882 | } | |
1883 | ||
1884 | /* Find the insertion position. */ | |
1885 | dref last = get_chain_root (chain); | |
1886 | for (i = 0; i < chain->refs.length (); i++) | |
1887 | { | |
1888 | if (chain->refs[i]->pos > last->pos) | |
1889 | last = chain->refs[i]; | |
1890 | } | |
1891 | ||
1892 | gimple_stmt_iterator gsi = gsi_for_stmt (last->stmt); | |
1893 | ||
1894 | /* Insert statements copying root value to root variable. */ | |
1895 | for (i = 0; i < n; i++) | |
1896 | { | |
1897 | var = chain->vars[i]; | |
1898 | val = vtemps[i]; | |
1899 | stmt = gimple_build_assign (var, val); | |
1900 | gsi_insert_after (&gsi, stmt, GSI_NEW_STMT); | |
1901 | } | |
1902 | } | |
1903 | ||
1904 | /* Generates stores for CHAIN's eliminated stores in LOOP's last | |
1905 | (CHAIN->length - 1) iterations. */ | |
1906 | ||
1907 | static void | |
99b1c316 | 1908 | finalize_eliminated_stores (class loop *loop, chain_p chain) |
d9c259ef BC |
1909 | { |
1910 | unsigned i, n = chain->length; | |
1911 | ||
1912 | for (i = 0; i < n; i++) | |
1913 | { | |
1914 | tree var = chain->vars[i]; | |
1915 | tree fini = chain->finis[n - i - 1]; | |
1916 | gimple *stmt = gimple_build_assign (fini, var); | |
1917 | ||
1918 | gimple_seq_add_stmt_without_update (&chain->fini_seq, stmt); | |
1919 | } | |
1920 | ||
1921 | if (chain->fini_seq) | |
1922 | { | |
1923 | gsi_insert_seq_on_edge_immediate (single_exit (loop), chain->fini_seq); | |
1924 | chain->fini_seq = NULL; | |
1925 | } | |
1926 | } | |
1927 | ||
bbc8a8dc ZD |
1928 | /* Initializes a variable for load motion for ROOT and prepares phi nodes and |
1929 | initialization on entry to LOOP if necessary. The ssa name for the variable | |
1930 | is stored in VARS. If WRITTEN is true, also a phi node to copy its value | |
1931 | around the loop is created. Uid of the newly created temporary variable | |
1932 | is marked in TMP_VARS. INITS is the list containing the (single) | |
1933 | initializer. */ | |
1934 | ||
1935 | static void | |
99b1c316 | 1936 | initialize_root_vars_lm (class loop *loop, dref root, bool written, |
9771b263 | 1937 | vec<tree> *vars, vec<tree> inits, |
bbc8a8dc ZD |
1938 | bitmap tmp_vars) |
1939 | { | |
1940 | unsigned i; | |
726a989a RB |
1941 | tree ref = DR_REF (root->ref), init, var, next; |
1942 | gimple_seq stmts; | |
538dd0b7 | 1943 | gphi *phi; |
bbc8a8dc ZD |
1944 | edge entry = loop_preheader_edge (loop), latch = loop_latch_edge (loop); |
1945 | ||
1946 | /* Find the initializer for the variable, and check that it cannot | |
1947 | trap. */ | |
9771b263 | 1948 | init = inits[0]; |
bbc8a8dc | 1949 | |
9771b263 | 1950 | vars->create (written ? 2 : 1); |
2664efb6 | 1951 | var = predcom_tmp_var (ref, 0, tmp_vars); |
9771b263 | 1952 | vars->quick_push (var); |
bbc8a8dc | 1953 | if (written) |
9771b263 | 1954 | vars->quick_push ((*vars)[0]); |
b8698a0f | 1955 | |
9771b263 | 1956 | FOR_EACH_VEC_ELT (*vars, i, var) |
b731b390 | 1957 | (*vars)[i] = make_ssa_name (var); |
bbc8a8dc | 1958 | |
9771b263 | 1959 | var = (*vars)[0]; |
b8698a0f | 1960 | |
bbc8a8dc ZD |
1961 | init = force_gimple_operand (init, &stmts, written, NULL_TREE); |
1962 | if (stmts) | |
5006671f | 1963 | gsi_insert_seq_on_edge_immediate (entry, stmts); |
bbc8a8dc ZD |
1964 | |
1965 | if (written) | |
1966 | { | |
9771b263 | 1967 | next = (*vars)[1]; |
bbc8a8dc | 1968 | phi = create_phi_node (var, loop->header); |
9e227d60 DC |
1969 | add_phi_arg (phi, init, entry, UNKNOWN_LOCATION); |
1970 | add_phi_arg (phi, next, latch, UNKNOWN_LOCATION); | |
bbc8a8dc ZD |
1971 | } |
1972 | else | |
1973 | { | |
538dd0b7 | 1974 | gassign *init_stmt = gimple_build_assign (var, init); |
726a989a | 1975 | gsi_insert_on_edge_immediate (entry, init_stmt); |
bbc8a8dc ZD |
1976 | } |
1977 | } | |
1978 | ||
1979 | ||
1980 | /* Execute load motion for references in chain CHAIN. Uids of the newly | |
1981 | created temporary variables are marked in TMP_VARS. */ | |
1982 | ||
1983 | static void | |
99b1c316 | 1984 | execute_load_motion (class loop *loop, chain_p chain, bitmap tmp_vars) |
bbc8a8dc | 1985 | { |
ef062b13 | 1986 | auto_vec<tree> vars; |
bbc8a8dc ZD |
1987 | dref a; |
1988 | unsigned n_writes = 0, ridx, i; | |
1989 | tree var; | |
1990 | ||
1991 | gcc_assert (chain->type == CT_INVARIANT); | |
1992 | gcc_assert (!chain->combined); | |
9771b263 | 1993 | FOR_EACH_VEC_ELT (chain->refs, i, a) |
b0af49c4 | 1994 | if (DR_IS_WRITE (a->ref)) |
bbc8a8dc | 1995 | n_writes++; |
b8698a0f | 1996 | |
bbc8a8dc | 1997 | /* If there are no reads in the loop, there is nothing to do. */ |
9771b263 | 1998 | if (n_writes == chain->refs.length ()) |
bbc8a8dc ZD |
1999 | return; |
2000 | ||
2001 | initialize_root_vars_lm (loop, get_chain_root (chain), n_writes > 0, | |
2002 | &vars, chain->inits, tmp_vars); | |
2003 | ||
2004 | ridx = 0; | |
9771b263 | 2005 | FOR_EACH_VEC_ELT (chain->refs, i, a) |
bbc8a8dc ZD |
2006 | { |
2007 | bool is_read = DR_IS_READ (a->ref); | |
bbc8a8dc | 2008 | |
b0af49c4 | 2009 | if (DR_IS_WRITE (a->ref)) |
bbc8a8dc ZD |
2010 | { |
2011 | n_writes--; | |
2012 | if (n_writes) | |
2013 | { | |
9771b263 | 2014 | var = vars[0]; |
b731b390 | 2015 | var = make_ssa_name (SSA_NAME_VAR (var)); |
9771b263 | 2016 | vars[0] = var; |
bbc8a8dc ZD |
2017 | } |
2018 | else | |
2019 | ridx = 1; | |
2020 | } | |
b8698a0f | 2021 | |
9771b263 | 2022 | replace_ref_with (a->stmt, vars[ridx], |
bbc8a8dc ZD |
2023 | !is_read, !is_read); |
2024 | } | |
bbc8a8dc ZD |
2025 | } |
2026 | ||
2027 | /* Returns the single statement in that NAME is used, excepting | |
2028 | the looparound phi nodes contained in one of the chains. If there is no | |
726a989a | 2029 | such statement, or more statements, NULL is returned. */ |
bbc8a8dc | 2030 | |
355fe088 | 2031 | static gimple * |
bbc8a8dc ZD |
2032 | single_nonlooparound_use (tree name) |
2033 | { | |
2034 | use_operand_p use; | |
2035 | imm_use_iterator it; | |
355fe088 | 2036 | gimple *stmt, *ret = NULL; |
bbc8a8dc ZD |
2037 | |
2038 | FOR_EACH_IMM_USE_FAST (use, it, name) | |
2039 | { | |
2040 | stmt = USE_STMT (use); | |
2041 | ||
726a989a | 2042 | if (gimple_code (stmt) == GIMPLE_PHI) |
bbc8a8dc ZD |
2043 | { |
2044 | /* Ignore uses in looparound phi nodes. Uses in other phi nodes | |
2045 | could not be processed anyway, so just fail for them. */ | |
2046 | if (bitmap_bit_p (looparound_phis, | |
2047 | SSA_NAME_VERSION (PHI_RESULT (stmt)))) | |
2048 | continue; | |
2049 | ||
726a989a | 2050 | return NULL; |
bbc8a8dc | 2051 | } |
b63f974e JJ |
2052 | else if (is_gimple_debug (stmt)) |
2053 | continue; | |
726a989a RB |
2054 | else if (ret != NULL) |
2055 | return NULL; | |
bbc8a8dc ZD |
2056 | else |
2057 | ret = stmt; | |
2058 | } | |
2059 | ||
2060 | return ret; | |
2061 | } | |
2062 | ||
2063 | /* Remove statement STMT, as well as the chain of assignments in that it is | |
2064 | used. */ | |
2065 | ||
2066 | static void | |
355fe088 | 2067 | remove_stmt (gimple *stmt) |
bbc8a8dc | 2068 | { |
726a989a | 2069 | tree name; |
355fe088 | 2070 | gimple *next; |
726a989a | 2071 | gimple_stmt_iterator psi; |
bbc8a8dc | 2072 | |
726a989a | 2073 | if (gimple_code (stmt) == GIMPLE_PHI) |
bbc8a8dc ZD |
2074 | { |
2075 | name = PHI_RESULT (stmt); | |
2076 | next = single_nonlooparound_use (name); | |
273ccb6d | 2077 | reset_debug_uses (stmt); |
726a989a RB |
2078 | psi = gsi_for_stmt (stmt); |
2079 | remove_phi_node (&psi, true); | |
bbc8a8dc ZD |
2080 | |
2081 | if (!next | |
5f8ecf45 | 2082 | || !gimple_assign_ssa_name_copy_p (next) |
726a989a | 2083 | || gimple_assign_rhs1 (next) != name) |
bbc8a8dc ZD |
2084 | return; |
2085 | ||
2086 | stmt = next; | |
2087 | } | |
2088 | ||
2089 | while (1) | |
2090 | { | |
726a989a | 2091 | gimple_stmt_iterator bsi; |
b8698a0f | 2092 | |
726a989a | 2093 | bsi = gsi_for_stmt (stmt); |
bbc8a8dc | 2094 | |
726a989a | 2095 | name = gimple_assign_lhs (stmt); |
d9c259ef BC |
2096 | if (TREE_CODE (name) == SSA_NAME) |
2097 | { | |
2098 | next = single_nonlooparound_use (name); | |
2099 | reset_debug_uses (stmt); | |
2100 | } | |
2101 | else | |
2102 | { | |
2103 | /* This is a store to be eliminated. */ | |
2104 | gcc_assert (gimple_vdef (stmt) != NULL); | |
2105 | next = NULL; | |
2106 | } | |
bbc8a8dc | 2107 | |
13714310 | 2108 | unlink_stmt_vdef (stmt); |
726a989a | 2109 | gsi_remove (&bsi, true); |
5f8ecf45 | 2110 | release_defs (stmt); |
bbc8a8dc ZD |
2111 | |
2112 | if (!next | |
5f8ecf45 | 2113 | || !gimple_assign_ssa_name_copy_p (next) |
726a989a | 2114 | || gimple_assign_rhs1 (next) != name) |
bbc8a8dc ZD |
2115 | return; |
2116 | ||
2117 | stmt = next; | |
2118 | } | |
2119 | } | |
2120 | ||
2121 | /* Perform the predictive commoning optimization for a chain CHAIN. | |
2122 | Uids of the newly created temporary variables are marked in TMP_VARS.*/ | |
2123 | ||
2124 | static void | |
99b1c316 | 2125 | execute_pred_commoning_chain (class loop *loop, chain_p chain, |
d9c259ef | 2126 | bitmap tmp_vars) |
bbc8a8dc | 2127 | { |
9cdcebf9 | 2128 | unsigned i; |
13714310 | 2129 | dref a; |
bbc8a8dc | 2130 | tree var; |
10dfaf9a | 2131 | bool in_lhs; |
bbc8a8dc ZD |
2132 | |
2133 | if (chain->combined) | |
2134 | { | |
2135 | /* For combined chains, just remove the statements that are used to | |
a933d47f RB |
2136 | compute the values of the expression (except for the root one). |
2137 | We delay this until after all chains are processed. */ | |
bbc8a8dc | 2138 | } |
d9c259ef BC |
2139 | else if (chain->type == CT_STORE_STORE) |
2140 | { | |
2141 | if (chain->length > 0) | |
2142 | { | |
39ff50ce BC |
2143 | if (chain->inv_store_elimination) |
2144 | { | |
2145 | /* If dead stores in this chain only store loop invariant | |
2146 | values, we can simply record the invariant value and use | |
2147 | it directly after loop. */ | |
2148 | initialize_root_vars_store_elim_1 (chain); | |
2149 | } | |
2150 | else | |
2151 | { | |
2152 | /* If dead stores in this chain store loop variant values, | |
2153 | we need to set up the variables by loading from memory | |
2154 | before loop and propagating it with PHI nodes. */ | |
2155 | initialize_root_vars_store_elim_2 (loop, chain, tmp_vars); | |
2156 | } | |
d9c259ef BC |
2157 | |
2158 | /* For inter-iteration store elimination chain, stores at each | |
2159 | distance in loop's last (chain->length - 1) iterations can't | |
2160 | be eliminated, because there is no following killing store. | |
2161 | We need to generate these stores after loop. */ | |
2162 | finalize_eliminated_stores (loop, chain); | |
2163 | } | |
2164 | ||
9cdcebf9 BC |
2165 | bool last_store_p = true; |
2166 | for (i = chain->refs.length (); i > 0; i--) | |
2167 | { | |
2168 | a = chain->refs[i - 1]; | |
2169 | /* Preserve the last store of the chain. Eliminate other stores | |
2170 | which are killed by the last one. */ | |
2171 | if (DR_IS_WRITE (a->ref)) | |
2172 | { | |
2173 | if (last_store_p) | |
2174 | last_store_p = false; | |
2175 | else | |
2176 | remove_stmt (a->stmt); | |
2177 | ||
2178 | continue; | |
2179 | } | |
2180 | ||
2181 | /* Any load in Store-Store chain must be dominated by a previous | |
2182 | store, we replace the load reference with rhs of the store. */ | |
2183 | dref b = get_chain_last_write_before_load (chain, i - 1); | |
2184 | gcc_assert (b != NULL); | |
2185 | var = gimple_assign_rhs1 (b->stmt); | |
2186 | replace_ref_with (a->stmt, var, false, false); | |
2187 | } | |
d9c259ef | 2188 | } |
bbc8a8dc ZD |
2189 | else |
2190 | { | |
10dfaf9a BC |
2191 | /* For non-combined chains, set up the variables that hold its value. */ |
2192 | initialize_root_vars (loop, chain, tmp_vars); | |
2193 | a = get_chain_root (chain); | |
2194 | in_lhs = (chain->type == CT_STORE_LOAD | |
2195 | || chain->type == CT_COMBINATION); | |
2196 | replace_ref_with (a->stmt, chain->vars[chain->length], true, in_lhs); | |
2197 | ||
2198 | /* Replace the uses of the original references by these variables. */ | |
9771b263 | 2199 | for (i = 1; chain->refs.iterate (i, &a); i++) |
bbc8a8dc | 2200 | { |
9771b263 | 2201 | var = chain->vars[chain->length - a->distance]; |
bbc8a8dc ZD |
2202 | replace_ref_with (a->stmt, var, false, false); |
2203 | } | |
2204 | } | |
2205 | } | |
2206 | ||
2207 | /* Determines the unroll factor necessary to remove as many temporary variable | |
2208 | copies as possible. CHAINS is the list of chains that will be | |
2209 | optimized. */ | |
2210 | ||
2211 | static unsigned | |
9771b263 | 2212 | determine_unroll_factor (vec<chain_p> chains) |
bbc8a8dc ZD |
2213 | { |
2214 | chain_p chain; | |
2215 | unsigned factor = 1, af, nfactor, i; | |
028d4092 | 2216 | unsigned max = param_max_unroll_times; |
bbc8a8dc | 2217 | |
9771b263 | 2218 | FOR_EACH_VEC_ELT (chains, i, chain) |
bbc8a8dc | 2219 | { |
8039a35d | 2220 | if (chain->type == CT_INVARIANT) |
bbc8a8dc | 2221 | continue; |
d9c259ef BC |
2222 | /* For now we can't handle unrolling when eliminating stores. */ |
2223 | else if (chain->type == CT_STORE_STORE) | |
2224 | return 1; | |
bbc8a8dc | 2225 | |
8039a35d RB |
2226 | if (chain->combined) |
2227 | { | |
2228 | /* For combined chains, we can't handle unrolling if we replace | |
2229 | looparound PHIs. */ | |
2230 | dref a; | |
2231 | unsigned j; | |
2232 | for (j = 1; chain->refs.iterate (j, &a); j++) | |
2233 | if (gimple_code (a->stmt) == GIMPLE_PHI) | |
2234 | return 1; | |
2235 | continue; | |
2236 | } | |
2237 | ||
bbc8a8dc ZD |
2238 | /* The best unroll factor for this chain is equal to the number of |
2239 | temporary variables that we create for it. */ | |
2240 | af = chain->length; | |
2241 | if (chain->has_max_use_after) | |
2242 | af++; | |
2243 | ||
2244 | nfactor = factor * af / gcd (factor, af); | |
2245 | if (nfactor <= max) | |
2246 | factor = nfactor; | |
2247 | } | |
2248 | ||
2249 | return factor; | |
2250 | } | |
2251 | ||
2252 | /* Perform the predictive commoning optimization for CHAINS. | |
2253 | Uids of the newly created temporary variables are marked in TMP_VARS. */ | |
2254 | ||
2255 | static void | |
99b1c316 | 2256 | execute_pred_commoning (class loop *loop, vec<chain_p> chains, |
bbc8a8dc ZD |
2257 | bitmap tmp_vars) |
2258 | { | |
2259 | chain_p chain; | |
2260 | unsigned i; | |
2261 | ||
9771b263 | 2262 | FOR_EACH_VEC_ELT (chains, i, chain) |
bbc8a8dc ZD |
2263 | { |
2264 | if (chain->type == CT_INVARIANT) | |
2265 | execute_load_motion (loop, chain, tmp_vars); | |
2266 | else | |
2267 | execute_pred_commoning_chain (loop, chain, tmp_vars); | |
2268 | } | |
b8698a0f | 2269 | |
a933d47f RB |
2270 | FOR_EACH_VEC_ELT (chains, i, chain) |
2271 | { | |
2272 | if (chain->type == CT_INVARIANT) | |
2273 | ; | |
2274 | else if (chain->combined) | |
2275 | { | |
2276 | /* For combined chains, just remove the statements that are used to | |
2277 | compute the values of the expression (except for the root one). */ | |
2278 | dref a; | |
2279 | unsigned j; | |
2280 | for (j = 1; chain->refs.iterate (j, &a); j++) | |
2281 | remove_stmt (a->stmt); | |
2282 | } | |
2283 | } | |
2284 | ||
bbc8a8dc ZD |
2285 | update_ssa (TODO_update_ssa_only_virtuals); |
2286 | } | |
2287 | ||
c80b4100 | 2288 | /* For each reference in CHAINS, if its defining statement is |
726a989a | 2289 | phi node, record the ssa name that is defined by it. */ |
bbc8a8dc ZD |
2290 | |
2291 | static void | |
9771b263 | 2292 | replace_phis_by_defined_names (vec<chain_p> chains) |
bbc8a8dc ZD |
2293 | { |
2294 | chain_p chain; | |
2295 | dref a; | |
2296 | unsigned i, j; | |
2297 | ||
9771b263 DN |
2298 | FOR_EACH_VEC_ELT (chains, i, chain) |
2299 | FOR_EACH_VEC_ELT (chain->refs, j, a) | |
bbc8a8dc | 2300 | { |
726a989a RB |
2301 | if (gimple_code (a->stmt) == GIMPLE_PHI) |
2302 | { | |
2303 | a->name_defined_by_phi = PHI_RESULT (a->stmt); | |
2304 | a->stmt = NULL; | |
2305 | } | |
bbc8a8dc ZD |
2306 | } |
2307 | } | |
2308 | ||
726a989a RB |
2309 | /* For each reference in CHAINS, if name_defined_by_phi is not |
2310 | NULL, use it to set the stmt field. */ | |
bbc8a8dc ZD |
2311 | |
2312 | static void | |
9771b263 | 2313 | replace_names_by_phis (vec<chain_p> chains) |
bbc8a8dc ZD |
2314 | { |
2315 | chain_p chain; | |
2316 | dref a; | |
2317 | unsigned i, j; | |
2318 | ||
9771b263 DN |
2319 | FOR_EACH_VEC_ELT (chains, i, chain) |
2320 | FOR_EACH_VEC_ELT (chain->refs, j, a) | |
726a989a | 2321 | if (a->stmt == NULL) |
bbc8a8dc | 2322 | { |
726a989a RB |
2323 | a->stmt = SSA_NAME_DEF_STMT (a->name_defined_by_phi); |
2324 | gcc_assert (gimple_code (a->stmt) == GIMPLE_PHI); | |
2325 | a->name_defined_by_phi = NULL_TREE; | |
bbc8a8dc ZD |
2326 | } |
2327 | } | |
2328 | ||
2329 | /* Wrapper over execute_pred_commoning, to pass it as a callback | |
2330 | to tree_transform_and_unroll_loop. */ | |
2331 | ||
2332 | struct epcc_data | |
2333 | { | |
9771b263 | 2334 | vec<chain_p> chains; |
bbc8a8dc ZD |
2335 | bitmap tmp_vars; |
2336 | }; | |
2337 | ||
2338 | static void | |
99b1c316 | 2339 | execute_pred_commoning_cbck (class loop *loop, void *data) |
bbc8a8dc | 2340 | { |
3d9a9f94 | 2341 | struct epcc_data *const dta = (struct epcc_data *) data; |
bbc8a8dc ZD |
2342 | |
2343 | /* Restore phi nodes that were replaced by ssa names before | |
2344 | tree_transform_and_unroll_loop (see detailed description in | |
2345 | tree_predictive_commoning_loop). */ | |
2346 | replace_names_by_phis (dta->chains); | |
2347 | execute_pred_commoning (loop, dta->chains, dta->tmp_vars); | |
2348 | } | |
2349 | ||
bbc8a8dc ZD |
2350 | /* Base NAME and all the names in the chain of phi nodes that use it |
2351 | on variable VAR. The phi nodes are recognized by being in the copies of | |
2352 | the header of the LOOP. */ | |
2353 | ||
2354 | static void | |
99b1c316 | 2355 | base_names_in_chain_on (class loop *loop, tree name, tree var) |
bbc8a8dc | 2356 | { |
355fe088 | 2357 | gimple *stmt, *phi; |
bbc8a8dc | 2358 | imm_use_iterator iter; |
bbc8a8dc | 2359 | |
b2ec94d4 | 2360 | replace_ssa_name_symbol (name, var); |
bbc8a8dc ZD |
2361 | |
2362 | while (1) | |
2363 | { | |
2364 | phi = NULL; | |
2365 | FOR_EACH_IMM_USE_STMT (stmt, iter, name) | |
2366 | { | |
726a989a RB |
2367 | if (gimple_code (stmt) == GIMPLE_PHI |
2368 | && flow_bb_inside_loop_p (loop, gimple_bb (stmt))) | |
bbc8a8dc ZD |
2369 | { |
2370 | phi = stmt; | |
2371 | BREAK_FROM_IMM_USE_STMT (iter); | |
2372 | } | |
2373 | } | |
2374 | if (!phi) | |
2375 | return; | |
2376 | ||
bbc8a8dc | 2377 | name = PHI_RESULT (phi); |
b2ec94d4 | 2378 | replace_ssa_name_symbol (name, var); |
bbc8a8dc ZD |
2379 | } |
2380 | } | |
2381 | ||
2382 | /* Given an unrolled LOOP after predictive commoning, remove the | |
2383 | register copies arising from phi nodes by changing the base | |
2384 | variables of SSA names. TMP_VARS is the set of the temporary variables | |
2385 | for those we want to perform this. */ | |
2386 | ||
2387 | static void | |
99b1c316 | 2388 | eliminate_temp_copies (class loop *loop, bitmap tmp_vars) |
bbc8a8dc ZD |
2389 | { |
2390 | edge e; | |
538dd0b7 | 2391 | gphi *phi; |
355fe088 | 2392 | gimple *stmt; |
726a989a | 2393 | tree name, use, var; |
538dd0b7 | 2394 | gphi_iterator psi; |
bbc8a8dc ZD |
2395 | |
2396 | e = loop_latch_edge (loop); | |
726a989a | 2397 | for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi)) |
bbc8a8dc | 2398 | { |
538dd0b7 | 2399 | phi = psi.phi (); |
bbc8a8dc ZD |
2400 | name = PHI_RESULT (phi); |
2401 | var = SSA_NAME_VAR (name); | |
70b5e7dc | 2402 | if (!var || !bitmap_bit_p (tmp_vars, DECL_UID (var))) |
bbc8a8dc ZD |
2403 | continue; |
2404 | use = PHI_ARG_DEF_FROM_EDGE (phi, e); | |
2405 | gcc_assert (TREE_CODE (use) == SSA_NAME); | |
2406 | ||
2407 | /* Base all the ssa names in the ud and du chain of NAME on VAR. */ | |
2408 | stmt = SSA_NAME_DEF_STMT (use); | |
726a989a | 2409 | while (gimple_code (stmt) == GIMPLE_PHI |
1b0cfaa6 ZD |
2410 | /* In case we could not unroll the loop enough to eliminate |
2411 | all copies, we may reach the loop header before the defining | |
2412 | statement (in that case, some register copies will be present | |
2413 | in loop latch in the final code, corresponding to the newly | |
2414 | created looparound phi nodes). */ | |
726a989a | 2415 | && gimple_bb (stmt) != loop->header) |
bbc8a8dc | 2416 | { |
726a989a | 2417 | gcc_assert (single_pred_p (gimple_bb (stmt))); |
bbc8a8dc ZD |
2418 | use = PHI_ARG_DEF (stmt, 0); |
2419 | stmt = SSA_NAME_DEF_STMT (use); | |
2420 | } | |
2421 | ||
2422 | base_names_in_chain_on (loop, use, var); | |
2423 | } | |
2424 | } | |
2425 | ||
2426 | /* Returns true if CHAIN is suitable to be combined. */ | |
2427 | ||
2428 | static bool | |
2429 | chain_can_be_combined_p (chain_p chain) | |
2430 | { | |
2431 | return (!chain->combined | |
2432 | && (chain->type == CT_LOAD || chain->type == CT_COMBINATION)); | |
2433 | } | |
2434 | ||
2435 | /* Returns the modify statement that uses NAME. Skips over assignment | |
2436 | statements, NAME is replaced with the actual name used in the returned | |
2437 | statement. */ | |
2438 | ||
355fe088 | 2439 | static gimple * |
bbc8a8dc ZD |
2440 | find_use_stmt (tree *name) |
2441 | { | |
355fe088 | 2442 | gimple *stmt; |
726a989a | 2443 | tree rhs, lhs; |
bbc8a8dc ZD |
2444 | |
2445 | /* Skip over assignments. */ | |
2446 | while (1) | |
2447 | { | |
2448 | stmt = single_nonlooparound_use (*name); | |
2449 | if (!stmt) | |
726a989a | 2450 | return NULL; |
bbc8a8dc | 2451 | |
726a989a RB |
2452 | if (gimple_code (stmt) != GIMPLE_ASSIGN) |
2453 | return NULL; | |
bbc8a8dc | 2454 | |
726a989a | 2455 | lhs = gimple_assign_lhs (stmt); |
bbc8a8dc | 2456 | if (TREE_CODE (lhs) != SSA_NAME) |
726a989a | 2457 | return NULL; |
bbc8a8dc | 2458 | |
726a989a RB |
2459 | if (gimple_assign_copy_p (stmt)) |
2460 | { | |
2461 | rhs = gimple_assign_rhs1 (stmt); | |
2462 | if (rhs != *name) | |
2463 | return NULL; | |
bbc8a8dc | 2464 | |
726a989a RB |
2465 | *name = lhs; |
2466 | } | |
2467 | else if (get_gimple_rhs_class (gimple_assign_rhs_code (stmt)) | |
2468 | == GIMPLE_BINARY_RHS) | |
2469 | return stmt; | |
2470 | else | |
2471 | return NULL; | |
bbc8a8dc | 2472 | } |
bbc8a8dc ZD |
2473 | } |
2474 | ||
2475 | /* Returns true if we may perform reassociation for operation CODE in TYPE. */ | |
2476 | ||
2477 | static bool | |
2478 | may_reassociate_p (tree type, enum tree_code code) | |
2479 | { | |
2480 | if (FLOAT_TYPE_P (type) | |
2481 | && !flag_unsafe_math_optimizations) | |
2482 | return false; | |
2483 | ||
2484 | return (commutative_tree_code (code) | |
2485 | && associative_tree_code (code)); | |
2486 | } | |
2487 | ||
2488 | /* If the operation used in STMT is associative and commutative, go through the | |
2489 | tree of the same operations and returns its root. Distance to the root | |
2490 | is stored in DISTANCE. */ | |
2491 | ||
355fe088 TS |
2492 | static gimple * |
2493 | find_associative_operation_root (gimple *stmt, unsigned *distance) | |
bbc8a8dc | 2494 | { |
726a989a | 2495 | tree lhs; |
355fe088 | 2496 | gimple *next; |
726a989a RB |
2497 | enum tree_code code = gimple_assign_rhs_code (stmt); |
2498 | tree type = TREE_TYPE (gimple_assign_lhs (stmt)); | |
bbc8a8dc ZD |
2499 | unsigned dist = 0; |
2500 | ||
726a989a RB |
2501 | if (!may_reassociate_p (type, code)) |
2502 | return NULL; | |
bbc8a8dc ZD |
2503 | |
2504 | while (1) | |
2505 | { | |
726a989a | 2506 | lhs = gimple_assign_lhs (stmt); |
bbc8a8dc ZD |
2507 | gcc_assert (TREE_CODE (lhs) == SSA_NAME); |
2508 | ||
2509 | next = find_use_stmt (&lhs); | |
726a989a RB |
2510 | if (!next |
2511 | || gimple_assign_rhs_code (next) != code) | |
bbc8a8dc ZD |
2512 | break; |
2513 | ||
2514 | stmt = next; | |
2515 | dist++; | |
2516 | } | |
2517 | ||
2518 | if (distance) | |
2519 | *distance = dist; | |
2520 | return stmt; | |
2521 | } | |
2522 | ||
2523 | /* Returns the common statement in that NAME1 and NAME2 have a use. If there | |
2524 | is no such statement, returns NULL_TREE. In case the operation used on | |
c80b4100 | 2525 | NAME1 and NAME2 is associative and commutative, returns the root of the |
bbc8a8dc ZD |
2526 | tree formed by this operation instead of the statement that uses NAME1 or |
2527 | NAME2. */ | |
2528 | ||
355fe088 | 2529 | static gimple * |
bbc8a8dc ZD |
2530 | find_common_use_stmt (tree *name1, tree *name2) |
2531 | { | |
355fe088 | 2532 | gimple *stmt1, *stmt2; |
bbc8a8dc ZD |
2533 | |
2534 | stmt1 = find_use_stmt (name1); | |
2535 | if (!stmt1) | |
726a989a | 2536 | return NULL; |
bbc8a8dc ZD |
2537 | |
2538 | stmt2 = find_use_stmt (name2); | |
2539 | if (!stmt2) | |
726a989a | 2540 | return NULL; |
bbc8a8dc ZD |
2541 | |
2542 | if (stmt1 == stmt2) | |
2543 | return stmt1; | |
2544 | ||
2545 | stmt1 = find_associative_operation_root (stmt1, NULL); | |
2546 | if (!stmt1) | |
726a989a | 2547 | return NULL; |
bbc8a8dc ZD |
2548 | stmt2 = find_associative_operation_root (stmt2, NULL); |
2549 | if (!stmt2) | |
726a989a | 2550 | return NULL; |
bbc8a8dc | 2551 | |
726a989a | 2552 | return (stmt1 == stmt2 ? stmt1 : NULL); |
bbc8a8dc ZD |
2553 | } |
2554 | ||
2555 | /* Checks whether R1 and R2 are combined together using CODE, with the result | |
2556 | in RSLT_TYPE, in order R1 CODE R2 if SWAP is false and in order R2 CODE R1 | |
2557 | if it is true. If CODE is ERROR_MARK, set these values instead. */ | |
2558 | ||
2559 | static bool | |
2560 | combinable_refs_p (dref r1, dref r2, | |
2561 | enum tree_code *code, bool *swap, tree *rslt_type) | |
2562 | { | |
2563 | enum tree_code acode; | |
2564 | bool aswap; | |
2565 | tree atype; | |
726a989a | 2566 | tree name1, name2; |
355fe088 | 2567 | gimple *stmt; |
bbc8a8dc ZD |
2568 | |
2569 | name1 = name_for_ref (r1); | |
2570 | name2 = name_for_ref (r2); | |
2571 | gcc_assert (name1 != NULL_TREE && name2 != NULL_TREE); | |
2572 | ||
2573 | stmt = find_common_use_stmt (&name1, &name2); | |
2574 | ||
7906dbe4 RB |
2575 | if (!stmt |
2576 | /* A simple post-dominance check - make sure the combination | |
2577 | is executed under the same condition as the references. */ | |
2578 | || (gimple_bb (stmt) != gimple_bb (r1->stmt) | |
2579 | && gimple_bb (stmt) != gimple_bb (r2->stmt))) | |
bbc8a8dc ZD |
2580 | return false; |
2581 | ||
726a989a | 2582 | acode = gimple_assign_rhs_code (stmt); |
bbc8a8dc | 2583 | aswap = (!commutative_tree_code (acode) |
726a989a RB |
2584 | && gimple_assign_rhs1 (stmt) != name1); |
2585 | atype = TREE_TYPE (gimple_assign_lhs (stmt)); | |
bbc8a8dc ZD |
2586 | |
2587 | if (*code == ERROR_MARK) | |
2588 | { | |
2589 | *code = acode; | |
2590 | *swap = aswap; | |
2591 | *rslt_type = atype; | |
2592 | return true; | |
2593 | } | |
2594 | ||
2595 | return (*code == acode | |
2596 | && *swap == aswap | |
2597 | && *rslt_type == atype); | |
2598 | } | |
2599 | ||
2600 | /* Remove OP from the operation on rhs of STMT, and replace STMT with | |
2601 | an assignment of the remaining operand. */ | |
2602 | ||
2603 | static void | |
355fe088 | 2604 | remove_name_from_operation (gimple *stmt, tree op) |
bbc8a8dc | 2605 | { |
726a989a RB |
2606 | tree other_op; |
2607 | gimple_stmt_iterator si; | |
bbc8a8dc | 2608 | |
726a989a | 2609 | gcc_assert (is_gimple_assign (stmt)); |
bbc8a8dc | 2610 | |
726a989a RB |
2611 | if (gimple_assign_rhs1 (stmt) == op) |
2612 | other_op = gimple_assign_rhs2 (stmt); | |
bbc8a8dc | 2613 | else |
726a989a RB |
2614 | other_op = gimple_assign_rhs1 (stmt); |
2615 | ||
2616 | si = gsi_for_stmt (stmt); | |
2617 | gimple_assign_set_rhs_from_tree (&si, other_op); | |
2618 | ||
2619 | /* We should not have reallocated STMT. */ | |
2620 | gcc_assert (gsi_stmt (si) == stmt); | |
2621 | ||
bbc8a8dc ZD |
2622 | update_stmt (stmt); |
2623 | } | |
2624 | ||
2625 | /* Reassociates the expression in that NAME1 and NAME2 are used so that they | |
1ad3d8aa | 2626 | are combined in a single statement, and returns this statement. */ |
bbc8a8dc | 2627 | |
355fe088 | 2628 | static gimple * |
1ad3d8aa | 2629 | reassociate_to_the_same_stmt (tree name1, tree name2) |
bbc8a8dc | 2630 | { |
355fe088 | 2631 | gimple *stmt1, *stmt2, *root1, *root2, *s1, *s2; |
538dd0b7 | 2632 | gassign *new_stmt, *tmp_stmt; |
726a989a | 2633 | tree new_name, tmp_name, var, r1, r2; |
bbc8a8dc ZD |
2634 | unsigned dist1, dist2; |
2635 | enum tree_code code; | |
2636 | tree type = TREE_TYPE (name1); | |
726a989a | 2637 | gimple_stmt_iterator bsi; |
bbc8a8dc ZD |
2638 | |
2639 | stmt1 = find_use_stmt (&name1); | |
2640 | stmt2 = find_use_stmt (&name2); | |
2641 | root1 = find_associative_operation_root (stmt1, &dist1); | |
2642 | root2 = find_associative_operation_root (stmt2, &dist2); | |
726a989a | 2643 | code = gimple_assign_rhs_code (stmt1); |
bbc8a8dc ZD |
2644 | |
2645 | gcc_assert (root1 && root2 && root1 == root2 | |
726a989a | 2646 | && code == gimple_assign_rhs_code (stmt2)); |
bbc8a8dc ZD |
2647 | |
2648 | /* Find the root of the nearest expression in that both NAME1 and NAME2 | |
2649 | are used. */ | |
2650 | r1 = name1; | |
2651 | s1 = stmt1; | |
2652 | r2 = name2; | |
2653 | s2 = stmt2; | |
2654 | ||
2655 | while (dist1 > dist2) | |
2656 | { | |
2657 | s1 = find_use_stmt (&r1); | |
726a989a | 2658 | r1 = gimple_assign_lhs (s1); |
bbc8a8dc ZD |
2659 | dist1--; |
2660 | } | |
2661 | while (dist2 > dist1) | |
2662 | { | |
2663 | s2 = find_use_stmt (&r2); | |
726a989a | 2664 | r2 = gimple_assign_lhs (s2); |
bbc8a8dc ZD |
2665 | dist2--; |
2666 | } | |
2667 | ||
2668 | while (s1 != s2) | |
2669 | { | |
2670 | s1 = find_use_stmt (&r1); | |
726a989a | 2671 | r1 = gimple_assign_lhs (s1); |
bbc8a8dc | 2672 | s2 = find_use_stmt (&r2); |
726a989a | 2673 | r2 = gimple_assign_lhs (s2); |
bbc8a8dc ZD |
2674 | } |
2675 | ||
2676 | /* Remove NAME1 and NAME2 from the statements in that they are used | |
2677 | currently. */ | |
2678 | remove_name_from_operation (stmt1, name1); | |
2679 | remove_name_from_operation (stmt2, name2); | |
2680 | ||
2681 | /* Insert the new statement combining NAME1 and NAME2 before S1, and | |
2682 | combine it with the rhs of S1. */ | |
acd63801 | 2683 | var = create_tmp_reg (type, "predreastmp"); |
b731b390 | 2684 | new_name = make_ssa_name (var); |
0d0e4a03 | 2685 | new_stmt = gimple_build_assign (new_name, code, name1, name2); |
bbc8a8dc | 2686 | |
acd63801 | 2687 | var = create_tmp_reg (type, "predreastmp"); |
b731b390 | 2688 | tmp_name = make_ssa_name (var); |
726a989a RB |
2689 | |
2690 | /* Rhs of S1 may now be either a binary expression with operation | |
2691 | CODE, or gimple_val (in case that stmt1 == s1 or stmt2 == s1, | |
2692 | so that name1 or name2 was removed from it). */ | |
0d0e4a03 JJ |
2693 | tmp_stmt = gimple_build_assign (tmp_name, gimple_assign_rhs_code (s1), |
2694 | gimple_assign_rhs1 (s1), | |
2695 | gimple_assign_rhs2 (s1)); | |
726a989a RB |
2696 | |
2697 | bsi = gsi_for_stmt (s1); | |
2698 | gimple_assign_set_rhs_with_ops (&bsi, code, new_name, tmp_name); | |
2699 | s1 = gsi_stmt (bsi); | |
bbc8a8dc ZD |
2700 | update_stmt (s1); |
2701 | ||
1ad3d8aa | 2702 | gsi_insert_before (&bsi, new_stmt, GSI_SAME_STMT); |
726a989a | 2703 | gsi_insert_before (&bsi, tmp_stmt, GSI_SAME_STMT); |
bbc8a8dc ZD |
2704 | |
2705 | return new_stmt; | |
2706 | } | |
2707 | ||
2708 | /* Returns the statement that combines references R1 and R2. In case R1 | |
2709 | and R2 are not used in the same statement, but they are used with an | |
2710 | associative and commutative operation in the same expression, reassociate | |
1ad3d8aa | 2711 | the expression so that they are used in the same statement. */ |
bbc8a8dc | 2712 | |
355fe088 | 2713 | static gimple * |
1ad3d8aa | 2714 | stmt_combining_refs (dref r1, dref r2) |
bbc8a8dc | 2715 | { |
355fe088 | 2716 | gimple *stmt1, *stmt2; |
bbc8a8dc ZD |
2717 | tree name1 = name_for_ref (r1); |
2718 | tree name2 = name_for_ref (r2); | |
2719 | ||
2720 | stmt1 = find_use_stmt (&name1); | |
2721 | stmt2 = find_use_stmt (&name2); | |
2722 | if (stmt1 == stmt2) | |
2723 | return stmt1; | |
2724 | ||
1ad3d8aa | 2725 | return reassociate_to_the_same_stmt (name1, name2); |
bbc8a8dc ZD |
2726 | } |
2727 | ||
2728 | /* Tries to combine chains CH1 and CH2 together. If this succeeds, the | |
2729 | description of the new chain is returned, otherwise we return NULL. */ | |
2730 | ||
2731 | static chain_p | |
2732 | combine_chains (chain_p ch1, chain_p ch2) | |
2733 | { | |
2734 | dref r1, r2, nw; | |
2735 | enum tree_code op = ERROR_MARK; | |
2736 | bool swap = false; | |
2737 | chain_p new_chain; | |
1ad3d8aa | 2738 | unsigned i; |
bbc8a8dc ZD |
2739 | tree rslt_type = NULL_TREE; |
2740 | ||
2741 | if (ch1 == ch2) | |
a90352a0 | 2742 | return NULL; |
bbc8a8dc ZD |
2743 | if (ch1->length != ch2->length) |
2744 | return NULL; | |
2745 | ||
9771b263 | 2746 | if (ch1->refs.length () != ch2->refs.length ()) |
bbc8a8dc ZD |
2747 | return NULL; |
2748 | ||
9771b263 DN |
2749 | for (i = 0; (ch1->refs.iterate (i, &r1) |
2750 | && ch2->refs.iterate (i, &r2)); i++) | |
bbc8a8dc ZD |
2751 | { |
2752 | if (r1->distance != r2->distance) | |
2753 | return NULL; | |
2754 | ||
2755 | if (!combinable_refs_p (r1, r2, &op, &swap, &rslt_type)) | |
2756 | return NULL; | |
2757 | } | |
2758 | ||
2759 | if (swap) | |
6b4db501 | 2760 | std::swap (ch1, ch2); |
bbc8a8dc ZD |
2761 | |
2762 | new_chain = XCNEW (struct chain); | |
2763 | new_chain->type = CT_COMBINATION; | |
82d6e6fc | 2764 | new_chain->op = op; |
bbc8a8dc ZD |
2765 | new_chain->ch1 = ch1; |
2766 | new_chain->ch2 = ch2; | |
2767 | new_chain->rslt_type = rslt_type; | |
2768 | new_chain->length = ch1->length; | |
2769 | ||
1ad3d8aa BC |
2770 | for (i = 0; (ch1->refs.iterate (i, &r1) |
2771 | && ch2->refs.iterate (i, &r2)); i++) | |
2772 | { | |
99b1c316 | 2773 | nw = XCNEW (class dref_d); |
1ad3d8aa | 2774 | nw->stmt = stmt_combining_refs (r1, r2); |
bbc8a8dc | 2775 | nw->distance = r1->distance; |
8539a302 | 2776 | |
d822f3d5 | 2777 | new_chain->refs.safe_push (nw); |
8539a302 | 2778 | } |
bbc8a8dc | 2779 | |
1ad3d8aa BC |
2780 | ch1->combined = true; |
2781 | ch2->combined = true; | |
bbc8a8dc ZD |
2782 | return new_chain; |
2783 | } | |
2784 | ||
bd9cc42b BC |
2785 | /* Recursively update position information of all offspring chains to ROOT |
2786 | chain's position information. */ | |
2787 | ||
2788 | static void | |
2789 | update_pos_for_combined_chains (chain_p root) | |
2790 | { | |
2791 | chain_p ch1 = root->ch1, ch2 = root->ch2; | |
2792 | dref ref, ref1, ref2; | |
2793 | for (unsigned j = 0; (root->refs.iterate (j, &ref) | |
2794 | && ch1->refs.iterate (j, &ref1) | |
2795 | && ch2->refs.iterate (j, &ref2)); ++j) | |
2796 | ref1->pos = ref2->pos = ref->pos; | |
2797 | ||
2798 | if (ch1->type == CT_COMBINATION) | |
2799 | update_pos_for_combined_chains (ch1); | |
2800 | if (ch2->type == CT_COMBINATION) | |
2801 | update_pos_for_combined_chains (ch2); | |
2802 | } | |
2803 | ||
2804 | /* Returns true if statement S1 dominates statement S2. */ | |
2805 | ||
2806 | static bool | |
2807 | pcom_stmt_dominates_stmt_p (gimple *s1, gimple *s2) | |
2808 | { | |
2809 | basic_block bb1 = gimple_bb (s1), bb2 = gimple_bb (s2); | |
2810 | ||
2811 | if (!bb1 || s1 == s2) | |
2812 | return true; | |
2813 | ||
2814 | if (bb1 == bb2) | |
2815 | return gimple_uid (s1) < gimple_uid (s2); | |
2816 | ||
2817 | return dominated_by_p (CDI_DOMINATORS, bb2, bb1); | |
2818 | } | |
2819 | ||
2820 | /* Try to combine the CHAINS in LOOP. */ | |
bbc8a8dc ZD |
2821 | |
2822 | static void | |
99b1c316 | 2823 | try_combine_chains (class loop *loop, vec<chain_p> *chains) |
bbc8a8dc ZD |
2824 | { |
2825 | unsigned i, j; | |
2826 | chain_p ch1, ch2, cch; | |
ef062b13 | 2827 | auto_vec<chain_p> worklist; |
bd9cc42b | 2828 | bool combined_p = false; |
bbc8a8dc | 2829 | |
9771b263 | 2830 | FOR_EACH_VEC_ELT (*chains, i, ch1) |
bbc8a8dc | 2831 | if (chain_can_be_combined_p (ch1)) |
9771b263 | 2832 | worklist.safe_push (ch1); |
bbc8a8dc | 2833 | |
9771b263 | 2834 | while (!worklist.is_empty ()) |
bbc8a8dc | 2835 | { |
9771b263 | 2836 | ch1 = worklist.pop (); |
bbc8a8dc ZD |
2837 | if (!chain_can_be_combined_p (ch1)) |
2838 | continue; | |
2839 | ||
9771b263 | 2840 | FOR_EACH_VEC_ELT (*chains, j, ch2) |
bbc8a8dc ZD |
2841 | { |
2842 | if (!chain_can_be_combined_p (ch2)) | |
2843 | continue; | |
2844 | ||
2845 | cch = combine_chains (ch1, ch2); | |
2846 | if (cch) | |
2847 | { | |
9771b263 DN |
2848 | worklist.safe_push (cch); |
2849 | chains->safe_push (cch); | |
bd9cc42b BC |
2850 | combined_p = true; |
2851 | break; | |
2852 | } | |
2853 | } | |
2854 | } | |
2855 | if (!combined_p) | |
2856 | return; | |
2857 | ||
2858 | /* Setup UID for all statements in dominance order. */ | |
3c2df916 | 2859 | basic_block *bbs = get_loop_body_in_dom_order (loop); |
bd9cc42b BC |
2860 | renumber_gimple_stmt_uids_in_blocks (bbs, loop->num_nodes); |
2861 | free (bbs); | |
2862 | ||
2863 | /* Re-association in combined chains may generate statements different to | |
2864 | order of references of the original chain. We need to keep references | |
2865 | of combined chain in dominance order so that all uses will be inserted | |
2866 | after definitions. Note: | |
2867 | A) This is necessary for all combined chains. | |
2868 | B) This is only necessary for ZERO distance references because other | |
2869 | references inherit value from loop carried PHIs. | |
2870 | ||
2871 | We first update position information for all combined chains. */ | |
2872 | dref ref; | |
2873 | for (i = 0; chains->iterate (i, &ch1); ++i) | |
2874 | { | |
2875 | if (ch1->type != CT_COMBINATION || ch1->combined) | |
2876 | continue; | |
2877 | ||
2878 | for (j = 0; ch1->refs.iterate (j, &ref); ++j) | |
2879 | ref->pos = gimple_uid (ref->stmt); | |
2880 | ||
2881 | update_pos_for_combined_chains (ch1); | |
2882 | } | |
2883 | /* Then sort references according to newly updated position information. */ | |
2884 | for (i = 0; chains->iterate (i, &ch1); ++i) | |
2885 | { | |
2886 | if (ch1->type != CT_COMBINATION && !ch1->combined) | |
2887 | continue; | |
2888 | ||
2889 | /* Find the first reference with non-ZERO distance. */ | |
2890 | if (ch1->length == 0) | |
2891 | j = ch1->refs.length(); | |
2892 | else | |
2893 | { | |
2894 | for (j = 0; ch1->refs.iterate (j, &ref); ++j) | |
2895 | if (ref->distance != 0) | |
2896 | break; | |
2897 | } | |
2898 | ||
2899 | /* Sort all ZERO distance references by position. */ | |
2900 | qsort (&ch1->refs[0], j, sizeof (ch1->refs[0]), order_drefs_by_pos); | |
2901 | ||
2902 | if (ch1->combined) | |
2903 | continue; | |
2904 | ||
2905 | /* For ZERO length chain, has_max_use_after must be true since root | |
2906 | combined stmt must dominates others. */ | |
2907 | if (ch1->length == 0) | |
2908 | { | |
2909 | ch1->has_max_use_after = true; | |
2910 | continue; | |
2911 | } | |
2912 | /* Check if there is use at max distance after root for combined chains | |
2913 | and set flag accordingly. */ | |
2914 | ch1->has_max_use_after = false; | |
2915 | gimple *root_stmt = get_chain_root (ch1)->stmt; | |
2916 | for (j = 1; ch1->refs.iterate (j, &ref); ++j) | |
2917 | { | |
2918 | if (ref->distance == ch1->length | |
2919 | && !pcom_stmt_dominates_stmt_p (ref->stmt, root_stmt)) | |
2920 | { | |
2921 | ch1->has_max_use_after = true; | |
bbc8a8dc ZD |
2922 | break; |
2923 | } | |
2924 | } | |
2925 | } | |
2926 | } | |
2927 | ||
d9c259ef BC |
2928 | /* Prepare initializers for store elimination CHAIN in LOOP. Returns false |
2929 | if this is impossible because one of these initializers may trap, true | |
2930 | otherwise. */ | |
2931 | ||
2932 | static bool | |
99b1c316 | 2933 | prepare_initializers_chain_store_elim (class loop *loop, chain_p chain) |
d9c259ef BC |
2934 | { |
2935 | unsigned i, n = chain->length; | |
2936 | ||
2937 | /* For now we can't eliminate stores if some of them are conditional | |
2938 | executed. */ | |
2939 | if (!chain->all_always_accessed) | |
2940 | return false; | |
2941 | ||
2942 | /* Nothing to intialize for intra-iteration store elimination. */ | |
2943 | if (n == 0 && chain->type == CT_STORE_STORE) | |
2944 | return true; | |
2945 | ||
39ff50ce BC |
2946 | /* For store elimination chain, there is nothing to initialize if stores |
2947 | to be eliminated only store loop invariant values into memory. */ | |
2948 | if (chain->type == CT_STORE_STORE | |
2949 | && is_inv_store_elimination_chain (loop, chain)) | |
2950 | { | |
2951 | chain->inv_store_elimination = true; | |
2952 | return true; | |
2953 | } | |
2954 | ||
d9c259ef BC |
2955 | chain->inits.create (n); |
2956 | chain->inits.safe_grow_cleared (n); | |
2957 | ||
2958 | /* For store eliminatin chain like below: | |
2959 | ||
2960 | for (i = 0; i < len; i++) | |
2961 | { | |
2962 | a[i] = 1; | |
2963 | // a[i + 1] = ... | |
2964 | a[i + 2] = 3; | |
2965 | } | |
2966 | ||
2967 | store to a[i + 1] is missed in loop body, it acts like bubbles. The | |
2968 | content of a[i + 1] remain the same if the loop iterates fewer times | |
2969 | than chain->length. We need to set up root variables for such stores | |
2970 | by loading from memory before loop. Note we only need to load bubble | |
2971 | elements because loop body is guaranteed to be executed at least once | |
2972 | after loop's preheader edge. */ | |
2973 | auto_vec<bool> bubbles; | |
2974 | bubbles.safe_grow_cleared (n + 1); | |
2975 | for (i = 0; i < chain->refs.length (); i++) | |
2976 | bubbles[chain->refs[i]->distance] = true; | |
2977 | ||
2978 | struct data_reference *dr = get_chain_root (chain)->ref; | |
2979 | for (i = 0; i < n; i++) | |
2980 | { | |
2981 | if (bubbles[i]) | |
2982 | continue; | |
2983 | ||
2984 | gimple_seq stmts = NULL; | |
2985 | ||
2986 | tree init = ref_at_iteration (dr, (int) 0 - i, &stmts); | |
2987 | if (stmts) | |
2988 | gimple_seq_add_seq_without_update (&chain->init_seq, stmts); | |
2989 | ||
2990 | chain->inits[i] = init; | |
2991 | } | |
2992 | ||
2993 | return true; | |
2994 | } | |
2995 | ||
bbc8a8dc ZD |
2996 | /* Prepare initializers for CHAIN in LOOP. Returns false if this is |
2997 | impossible because one of these initializers may trap, true otherwise. */ | |
2998 | ||
2999 | static bool | |
99b1c316 | 3000 | prepare_initializers_chain (class loop *loop, chain_p chain) |
bbc8a8dc ZD |
3001 | { |
3002 | unsigned i, n = (chain->type == CT_INVARIANT) ? 1 : chain->length; | |
3003 | struct data_reference *dr = get_chain_root (chain)->ref; | |
726a989a | 3004 | tree init; |
bbc8a8dc ZD |
3005 | dref laref; |
3006 | edge entry = loop_preheader_edge (loop); | |
3007 | ||
d9c259ef BC |
3008 | if (chain->type == CT_STORE_STORE) |
3009 | return prepare_initializers_chain_store_elim (loop, chain); | |
3010 | ||
bbc8a8dc ZD |
3011 | /* Find the initializers for the variables, and check that they cannot |
3012 | trap. */ | |
9771b263 | 3013 | chain->inits.create (n); |
bbc8a8dc | 3014 | for (i = 0; i < n; i++) |
9771b263 | 3015 | chain->inits.quick_push (NULL_TREE); |
bbc8a8dc ZD |
3016 | |
3017 | /* If we have replaced some looparound phi nodes, use their initializers | |
3018 | instead of creating our own. */ | |
9771b263 | 3019 | FOR_EACH_VEC_ELT (chain->refs, i, laref) |
bbc8a8dc | 3020 | { |
726a989a | 3021 | if (gimple_code (laref->stmt) != GIMPLE_PHI) |
bbc8a8dc ZD |
3022 | continue; |
3023 | ||
3024 | gcc_assert (laref->distance > 0); | |
9771b263 DN |
3025 | chain->inits[n - laref->distance] |
3026 | = PHI_ARG_DEF_FROM_EDGE (laref->stmt, entry); | |
bbc8a8dc ZD |
3027 | } |
3028 | ||
3029 | for (i = 0; i < n; i++) | |
3030 | { | |
7ec44c3d RB |
3031 | gimple_seq stmts = NULL; |
3032 | ||
9771b263 | 3033 | if (chain->inits[i] != NULL_TREE) |
bbc8a8dc ZD |
3034 | continue; |
3035 | ||
9f2b860b | 3036 | init = ref_at_iteration (dr, (int) i - n, &stmts); |
bbc8a8dc | 3037 | if (!chain->all_always_accessed && tree_could_trap_p (init)) |
7ec44c3d RB |
3038 | { |
3039 | gimple_seq_discard (stmts); | |
3040 | return false; | |
3041 | } | |
bbc8a8dc | 3042 | |
bbc8a8dc | 3043 | if (stmts) |
aa4de160 | 3044 | gimple_seq_add_seq_without_update (&chain->init_seq, stmts); |
bbc8a8dc | 3045 | |
9771b263 | 3046 | chain->inits[i] = init; |
bbc8a8dc ZD |
3047 | } |
3048 | ||
3049 | return true; | |
3050 | } | |
3051 | ||
3052 | /* Prepare initializers for CHAINS in LOOP, and free chains that cannot | |
3053 | be used because the initializers might trap. */ | |
3054 | ||
3055 | static void | |
99b1c316 | 3056 | prepare_initializers (class loop *loop, vec<chain_p> chains) |
bbc8a8dc ZD |
3057 | { |
3058 | chain_p chain; | |
3059 | unsigned i; | |
3060 | ||
9771b263 | 3061 | for (i = 0; i < chains.length (); ) |
bbc8a8dc | 3062 | { |
9771b263 | 3063 | chain = chains[i]; |
bbc8a8dc ZD |
3064 | if (prepare_initializers_chain (loop, chain)) |
3065 | i++; | |
3066 | else | |
3067 | { | |
3068 | release_chain (chain); | |
9771b263 | 3069 | chains.unordered_remove (i); |
bbc8a8dc ZD |
3070 | } |
3071 | } | |
3072 | } | |
3073 | ||
d9c259ef BC |
3074 | /* Generates finalizer memory references for CHAIN in LOOP. Returns true |
3075 | if finalizer code for CHAIN can be generated, otherwise false. */ | |
3076 | ||
3077 | static bool | |
99b1c316 | 3078 | prepare_finalizers_chain (class loop *loop, chain_p chain) |
d9c259ef BC |
3079 | { |
3080 | unsigned i, n = chain->length; | |
3081 | struct data_reference *dr = get_chain_root (chain)->ref; | |
3082 | tree fini, niters = number_of_latch_executions (loop); | |
3083 | ||
3084 | /* For now we can't eliminate stores if some of them are conditional | |
3085 | executed. */ | |
3086 | if (!chain->all_always_accessed) | |
3087 | return false; | |
3088 | ||
3089 | chain->finis.create (n); | |
3090 | for (i = 0; i < n; i++) | |
3091 | chain->finis.quick_push (NULL_TREE); | |
3092 | ||
3093 | /* We never use looparound phi node for store elimination chains. */ | |
3094 | ||
3095 | /* Find the finalizers for the variables, and check that they cannot | |
3096 | trap. */ | |
3097 | for (i = 0; i < n; i++) | |
3098 | { | |
3099 | gimple_seq stmts = NULL; | |
3100 | gcc_assert (chain->finis[i] == NULL_TREE); | |
3101 | ||
3102 | if (TREE_CODE (niters) != INTEGER_CST && TREE_CODE (niters) != SSA_NAME) | |
3103 | { | |
a5c93f53 | 3104 | niters = unshare_expr (niters); |
d9c259ef BC |
3105 | niters = force_gimple_operand (niters, &stmts, true, NULL); |
3106 | if (stmts) | |
3107 | { | |
3108 | gimple_seq_add_seq_without_update (&chain->fini_seq, stmts); | |
3109 | stmts = NULL; | |
3110 | } | |
3111 | } | |
3112 | fini = ref_at_iteration (dr, (int) 0 - i, &stmts, niters); | |
3113 | if (stmts) | |
3114 | gimple_seq_add_seq_without_update (&chain->fini_seq, stmts); | |
3115 | ||
3116 | chain->finis[i] = fini; | |
3117 | } | |
3118 | ||
3119 | return true; | |
3120 | } | |
3121 | ||
3122 | /* Generates finalizer memory reference for CHAINS in LOOP. Returns true | |
3123 | if finalizer code generation for CHAINS breaks loop closed ssa form. */ | |
3124 | ||
3125 | static bool | |
99b1c316 | 3126 | prepare_finalizers (class loop *loop, vec<chain_p> chains) |
d9c259ef BC |
3127 | { |
3128 | chain_p chain; | |
3129 | unsigned i; | |
3130 | bool loop_closed_ssa = false; | |
3131 | ||
3132 | for (i = 0; i < chains.length ();) | |
3133 | { | |
3134 | chain = chains[i]; | |
3135 | ||
3136 | /* Finalizer is only necessary for inter-iteration store elimination | |
3137 | chains. */ | |
3138 | if (chain->length == 0 || chain->type != CT_STORE_STORE) | |
3139 | { | |
3140 | i++; | |
3141 | continue; | |
3142 | } | |
3143 | ||
3144 | if (prepare_finalizers_chain (loop, chain)) | |
3145 | { | |
3146 | i++; | |
7061cfc0 BC |
3147 | /* Be conservative, assume loop closed ssa form is corrupted |
3148 | by store-store chain. Though it's not always the case if | |
3149 | eliminated stores only store loop invariant values into | |
3150 | memory. */ | |
3151 | loop_closed_ssa = true; | |
d9c259ef BC |
3152 | } |
3153 | else | |
3154 | { | |
3155 | release_chain (chain); | |
3156 | chains.unordered_remove (i); | |
3157 | } | |
3158 | } | |
3159 | return loop_closed_ssa; | |
3160 | } | |
3161 | ||
aa4de160 BC |
3162 | /* Insert all initializing gimple stmts into loop's entry edge. */ |
3163 | ||
3164 | static void | |
99b1c316 | 3165 | insert_init_seqs (class loop *loop, vec<chain_p> chains) |
aa4de160 BC |
3166 | { |
3167 | unsigned i; | |
3168 | edge entry = loop_preheader_edge (loop); | |
3169 | ||
3170 | for (i = 0; i < chains.length (); ++i) | |
3171 | if (chains[i]->init_seq) | |
3172 | { | |
3173 | gsi_insert_seq_on_edge_immediate (entry, chains[i]->init_seq); | |
3174 | chains[i]->init_seq = NULL; | |
3175 | } | |
3176 | } | |
3177 | ||
d9c259ef BC |
3178 | /* Performs predictive commoning for LOOP. Sets bit 1<<0 of return value |
3179 | if LOOP was unrolled; Sets bit 1<<1 of return value if loop closed ssa | |
3180 | form was corrupted. */ | |
bbc8a8dc | 3181 | |
d9c259ef | 3182 | static unsigned |
99b1c316 | 3183 | tree_predictive_commoning_loop (class loop *loop) |
bbc8a8dc | 3184 | { |
9771b263 DN |
3185 | vec<data_reference_p> datarefs; |
3186 | vec<ddr_p> dependences; | |
bbc8a8dc | 3187 | struct component *components; |
6e1aa848 | 3188 | vec<chain_p> chains = vNULL; |
bbc8a8dc | 3189 | unsigned unroll_factor; |
99b1c316 | 3190 | class tree_niter_desc desc; |
d9c259ef | 3191 | bool unroll = false, loop_closed_ssa = false; |
bbc8a8dc | 3192 | edge exit; |
bbc8a8dc ZD |
3193 | |
3194 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3195 | fprintf (dump_file, "Processing loop %d\n", loop->num); | |
3196 | ||
b8a4b8c8 BC |
3197 | /* Nothing for predicitive commoning if loop only iterates 1 time. */ |
3198 | if (get_max_loop_iterations_int (loop) == 0) | |
3199 | { | |
3200 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3201 | fprintf (dump_file, "Loop iterates only 1 time, nothing to do.\n"); | |
3202 | ||
d9c259ef | 3203 | return 0; |
b8a4b8c8 BC |
3204 | } |
3205 | ||
bbc8a8dc ZD |
3206 | /* Find the data references and split them into components according to their |
3207 | dependence relations. */ | |
00f96dc9 | 3208 | auto_vec<loop_p, 3> loop_nest; |
9771b263 | 3209 | dependences.create (10); |
07687835 | 3210 | datarefs.create (10); |
9ca3d00e AB |
3211 | if (! compute_data_dependences_for_loop (loop, true, &loop_nest, &datarefs, |
3212 | &dependences)) | |
3213 | { | |
3214 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3215 | fprintf (dump_file, "Cannot analyze data dependencies\n"); | |
9ca3d00e AB |
3216 | free_data_refs (datarefs); |
3217 | free_dependence_relations (dependences); | |
d9c259ef | 3218 | return 0; |
9ca3d00e AB |
3219 | } |
3220 | ||
bbc8a8dc ZD |
3221 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3222 | dump_data_dependence_relations (dump_file, dependences); | |
3223 | ||
3224 | components = split_data_refs_to_components (loop, datarefs, dependences); | |
9771b263 | 3225 | loop_nest.release (); |
bbc8a8dc ZD |
3226 | free_dependence_relations (dependences); |
3227 | if (!components) | |
3228 | { | |
3229 | free_data_refs (datarefs); | |
4f87d581 | 3230 | free_affine_expand_cache (&name_expansions); |
d9c259ef | 3231 | return 0; |
bbc8a8dc ZD |
3232 | } |
3233 | ||
3234 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3235 | { | |
3236 | fprintf (dump_file, "Initial state:\n\n"); | |
3237 | dump_components (dump_file, components); | |
3238 | } | |
3239 | ||
3240 | /* Find the suitable components and split them into chains. */ | |
3241 | components = filter_suitable_components (loop, components); | |
3242 | ||
0e3de1d4 | 3243 | auto_bitmap tmp_vars; |
bbc8a8dc ZD |
3244 | looparound_phis = BITMAP_ALLOC (NULL); |
3245 | determine_roots (loop, components, &chains); | |
3246 | release_components (components); | |
3247 | ||
9771b263 | 3248 | if (!chains.exists ()) |
bbc8a8dc ZD |
3249 | { |
3250 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3251 | fprintf (dump_file, | |
3252 | "Predictive commoning failed: no suitable chains\n"); | |
3253 | goto end; | |
3254 | } | |
3255 | prepare_initializers (loop, chains); | |
d9c259ef | 3256 | loop_closed_ssa = prepare_finalizers (loop, chains); |
bbc8a8dc ZD |
3257 | |
3258 | /* Try to combine the chains that are always worked with together. */ | |
bd9cc42b | 3259 | try_combine_chains (loop, &chains); |
bbc8a8dc | 3260 | |
aa4de160 BC |
3261 | insert_init_seqs (loop, chains); |
3262 | ||
bbc8a8dc ZD |
3263 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3264 | { | |
3265 | fprintf (dump_file, "Before commoning:\n\n"); | |
3266 | dump_chains (dump_file, chains); | |
3267 | } | |
3268 | ||
3269 | /* Determine the unroll factor, and if the loop should be unrolled, ensure | |
3270 | that its number of iterations is divisible by the factor. */ | |
3271 | unroll_factor = determine_unroll_factor (chains); | |
3272 | scev_reset (); | |
e1e6dc73 RG |
3273 | unroll = (unroll_factor > 1 |
3274 | && can_unroll_loop_p (loop, unroll_factor, &desc)); | |
bbc8a8dc ZD |
3275 | exit = single_dom_exit (loop); |
3276 | ||
3277 | /* Execute the predictive commoning transformations, and possibly unroll the | |
3278 | loop. */ | |
3279 | if (unroll) | |
3280 | { | |
3281 | struct epcc_data dta; | |
3282 | ||
3283 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3284 | fprintf (dump_file, "Unrolling %u times.\n", unroll_factor); | |
3285 | ||
3286 | dta.chains = chains; | |
3287 | dta.tmp_vars = tmp_vars; | |
b8698a0f | 3288 | |
bbc8a8dc ZD |
3289 | update_ssa (TODO_update_ssa_only_virtuals); |
3290 | ||
3291 | /* Cfg manipulations performed in tree_transform_and_unroll_loop before | |
3292 | execute_pred_commoning_cbck is called may cause phi nodes to be | |
3293 | reallocated, which is a problem since CHAINS may point to these | |
3294 | statements. To fix this, we store the ssa names defined by the | |
3295 | phi nodes here instead of the phi nodes themselves, and restore | |
3296 | the phi nodes in execute_pred_commoning_cbck. A bit hacky. */ | |
3297 | replace_phis_by_defined_names (chains); | |
3298 | ||
3299 | tree_transform_and_unroll_loop (loop, unroll_factor, exit, &desc, | |
3300 | execute_pred_commoning_cbck, &dta); | |
3301 | eliminate_temp_copies (loop, tmp_vars); | |
3302 | } | |
3303 | else | |
3304 | { | |
3305 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3306 | fprintf (dump_file, | |
3307 | "Executing predictive commoning without unrolling.\n"); | |
3308 | execute_pred_commoning (loop, chains, tmp_vars); | |
3309 | } | |
3310 | ||
3311 | end: ; | |
3312 | release_chains (chains); | |
3313 | free_data_refs (datarefs); | |
bbc8a8dc ZD |
3314 | BITMAP_FREE (looparound_phis); |
3315 | ||
3316 | free_affine_expand_cache (&name_expansions); | |
3317 | ||
d9c259ef | 3318 | return (unroll ? 1 : 0) | (loop_closed_ssa ? 2 : 0); |
bbc8a8dc ZD |
3319 | } |
3320 | ||
3321 | /* Runs predictive commoning. */ | |
3322 | ||
592c303d | 3323 | unsigned |
bbc8a8dc ZD |
3324 | tree_predictive_commoning (void) |
3325 | { | |
99b1c316 | 3326 | class loop *loop; |
d9c259ef | 3327 | unsigned ret = 0, changed = 0; |
bbc8a8dc ZD |
3328 | |
3329 | initialize_original_copy_tables (); | |
f0bd40b1 | 3330 | FOR_EACH_LOOP (loop, LI_ONLY_INNERMOST) |
8bcf15f6 JH |
3331 | if (optimize_loop_for_speed_p (loop)) |
3332 | { | |
d9c259ef | 3333 | changed |= tree_predictive_commoning_loop (loop); |
8bcf15f6 | 3334 | } |
d9c259ef | 3335 | free_original_copy_tables (); |
bbc8a8dc | 3336 | |
d9c259ef | 3337 | if (changed > 0) |
bbc8a8dc ZD |
3338 | { |
3339 | scev_reset (); | |
d9c259ef BC |
3340 | |
3341 | if (changed > 1) | |
3342 | rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa); | |
3343 | ||
592c303d | 3344 | ret = TODO_cleanup_cfg; |
bbc8a8dc | 3345 | } |
592c303d ZD |
3346 | |
3347 | return ret; | |
bbc8a8dc | 3348 | } |
c1bf2a39 AM |
3349 | |
3350 | /* Predictive commoning Pass. */ | |
3351 | ||
3352 | static unsigned | |
726338f4 | 3353 | run_tree_predictive_commoning (struct function *fun) |
c1bf2a39 | 3354 | { |
726338f4 | 3355 | if (number_of_loops (fun) <= 1) |
c1bf2a39 AM |
3356 | return 0; |
3357 | ||
3358 | return tree_predictive_commoning (); | |
3359 | } | |
3360 | ||
c1bf2a39 AM |
3361 | namespace { |
3362 | ||
3363 | const pass_data pass_data_predcom = | |
3364 | { | |
3365 | GIMPLE_PASS, /* type */ | |
3366 | "pcom", /* name */ | |
3367 | OPTGROUP_LOOP, /* optinfo_flags */ | |
c1bf2a39 AM |
3368 | TV_PREDCOM, /* tv_id */ |
3369 | PROP_cfg, /* properties_required */ | |
3370 | 0, /* properties_provided */ | |
3371 | 0, /* properties_destroyed */ | |
3372 | 0, /* todo_flags_start */ | |
3373 | TODO_update_ssa_only_virtuals, /* todo_flags_finish */ | |
3374 | }; | |
3375 | ||
3376 | class pass_predcom : public gimple_opt_pass | |
3377 | { | |
3378 | public: | |
3379 | pass_predcom (gcc::context *ctxt) | |
3380 | : gimple_opt_pass (pass_data_predcom, ctxt) | |
3381 | {} | |
3382 | ||
3383 | /* opt_pass methods: */ | |
1a3d085c | 3384 | virtual bool gate (function *) { return flag_predictive_commoning != 0; } |
726338f4 | 3385 | virtual unsigned int execute (function *fun) |
be55bfe6 | 3386 | { |
726338f4 | 3387 | return run_tree_predictive_commoning (fun); |
be55bfe6 | 3388 | } |
c1bf2a39 AM |
3389 | |
3390 | }; // class pass_predcom | |
3391 | ||
3392 | } // anon namespace | |
3393 | ||
3394 | gimple_opt_pass * | |
3395 | make_pass_predcom (gcc::context *ctxt) | |
3396 | { | |
3397 | return new pass_predcom (ctxt); | |
3398 | } | |
3399 | ||
3400 |