2018-03-27 Richard Biener <rguenther@suse.de>
[official-gcc.git] / gcc / tree-ssa-loop.c
blob6c3e516d536d0865f5f2c597229a7575fa599779
1 /* Loop optimizations over tree-ssa.
2 Copyright (C) 2003-2018 Free Software Foundation, Inc.
4 This file is part of GCC.
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
8 Free Software Foundation; either version 3, or (at your option) any
9 later version.
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.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
20 #include "config.h"
21 #include "system.h"
22 #include "coretypes.h"
23 #include "backend.h"
24 #include "tree.h"
25 #include "gimple.h"
26 #include "tree-pass.h"
27 #include "memmodel.h"
28 #include "tm_p.h"
29 #include "fold-const.h"
30 #include "gimple-iterator.h"
31 #include "tree-ssa-loop-ivopts.h"
32 #include "tree-ssa-loop-manip.h"
33 #include "tree-ssa-loop-niter.h"
34 #include "tree-ssa-loop.h"
35 #include "cfgloop.h"
36 #include "tree-inline.h"
37 #include "tree-scalar-evolution.h"
38 #include "tree-vectorizer.h"
39 #include "omp-general.h"
40 #include "diagnostic-core.h"
41 #include "stringpool.h"
42 #include "attribs.h"
45 /* A pass making sure loops are fixed up. */
47 namespace {
49 const pass_data pass_data_fix_loops =
51 GIMPLE_PASS, /* type */
52 "fix_loops", /* name */
53 OPTGROUP_LOOP, /* optinfo_flags */
54 TV_TREE_LOOP, /* tv_id */
55 PROP_cfg, /* properties_required */
56 0, /* properties_provided */
57 0, /* properties_destroyed */
58 0, /* todo_flags_start */
59 0, /* todo_flags_finish */
62 class pass_fix_loops : public gimple_opt_pass
64 public:
65 pass_fix_loops (gcc::context *ctxt)
66 : gimple_opt_pass (pass_data_fix_loops, ctxt)
69 /* opt_pass methods: */
70 virtual bool gate (function *) { return flag_tree_loop_optimize; }
72 virtual unsigned int execute (function *fn);
73 }; // class pass_fix_loops
75 unsigned int
76 pass_fix_loops::execute (function *)
78 if (loops_state_satisfies_p (LOOPS_NEED_FIXUP))
80 calculate_dominance_info (CDI_DOMINATORS);
81 fix_loop_structure (NULL);
83 return 0;
86 } // anon namespace
88 gimple_opt_pass *
89 make_pass_fix_loops (gcc::context *ctxt)
91 return new pass_fix_loops (ctxt);
95 /* Gate for loop pass group. The group is controlled by -ftree-loop-optimize
96 but we also avoid running it when the IL doesn't contain any loop. */
98 static bool
99 gate_loop (function *fn)
101 if (!flag_tree_loop_optimize)
102 return false;
104 /* For -fdump-passes which runs before loop discovery print the
105 state of -ftree-loop-optimize. */
106 if (!loops_for_fn (fn))
107 return true;
109 return number_of_loops (fn) > 1;
112 /* The loop superpass. */
114 namespace {
116 const pass_data pass_data_tree_loop =
118 GIMPLE_PASS, /* type */
119 "loop", /* name */
120 OPTGROUP_LOOP, /* optinfo_flags */
121 TV_TREE_LOOP, /* tv_id */
122 PROP_cfg, /* properties_required */
123 0, /* properties_provided */
124 0, /* properties_destroyed */
125 0, /* todo_flags_start */
126 0, /* todo_flags_finish */
129 class pass_tree_loop : public gimple_opt_pass
131 public:
132 pass_tree_loop (gcc::context *ctxt)
133 : gimple_opt_pass (pass_data_tree_loop, ctxt)
136 /* opt_pass methods: */
137 virtual bool gate (function *fn) { return gate_loop (fn); }
139 }; // class pass_tree_loop
141 } // anon namespace
143 gimple_opt_pass *
144 make_pass_tree_loop (gcc::context *ctxt)
146 return new pass_tree_loop (ctxt);
149 /* Gate for oacc kernels pass group. */
151 static bool
152 gate_oacc_kernels (function *fn)
154 if (!flag_openacc)
155 return false;
157 if (!lookup_attribute ("oacc kernels", DECL_ATTRIBUTES (fn->decl)))
158 return false;
160 struct loop *loop;
161 FOR_EACH_LOOP (loop, 0)
162 if (loop->in_oacc_kernels_region)
163 return true;
165 return false;
168 /* The oacc kernels superpass. */
170 namespace {
172 const pass_data pass_data_oacc_kernels =
174 GIMPLE_PASS, /* type */
175 "oacc_kernels", /* name */
176 OPTGROUP_LOOP, /* optinfo_flags */
177 TV_TREE_LOOP, /* tv_id */
178 PROP_cfg, /* properties_required */
179 0, /* properties_provided */
180 0, /* properties_destroyed */
181 0, /* todo_flags_start */
182 0, /* todo_flags_finish */
185 class pass_oacc_kernels : public gimple_opt_pass
187 public:
188 pass_oacc_kernels (gcc::context *ctxt)
189 : gimple_opt_pass (pass_data_oacc_kernels, ctxt)
192 /* opt_pass methods: */
193 virtual bool gate (function *fn) { return gate_oacc_kernels (fn); }
195 }; // class pass_oacc_kernels
197 } // anon namespace
199 gimple_opt_pass *
200 make_pass_oacc_kernels (gcc::context *ctxt)
202 return new pass_oacc_kernels (ctxt);
205 /* The ipa oacc superpass. */
207 namespace {
209 const pass_data pass_data_ipa_oacc =
211 SIMPLE_IPA_PASS, /* type */
212 "ipa_oacc", /* name */
213 OPTGROUP_LOOP, /* optinfo_flags */
214 TV_TREE_LOOP, /* tv_id */
215 PROP_cfg, /* properties_required */
216 0, /* properties_provided */
217 0, /* properties_destroyed */
218 0, /* todo_flags_start */
219 0, /* todo_flags_finish */
222 class pass_ipa_oacc : public simple_ipa_opt_pass
224 public:
225 pass_ipa_oacc (gcc::context *ctxt)
226 : simple_ipa_opt_pass (pass_data_ipa_oacc, ctxt)
229 /* opt_pass methods: */
230 virtual bool gate (function *)
232 return (optimize
233 && flag_openacc
234 /* Don't bother doing anything if the program has errors. */
235 && !seen_error ());
238 }; // class pass_ipa_oacc
240 } // anon namespace
242 simple_ipa_opt_pass *
243 make_pass_ipa_oacc (gcc::context *ctxt)
245 return new pass_ipa_oacc (ctxt);
248 /* The ipa oacc kernels pass. */
250 namespace {
252 const pass_data pass_data_ipa_oacc_kernels =
254 SIMPLE_IPA_PASS, /* type */
255 "ipa_oacc_kernels", /* name */
256 OPTGROUP_LOOP, /* optinfo_flags */
257 TV_TREE_LOOP, /* tv_id */
258 PROP_cfg, /* properties_required */
259 0, /* properties_provided */
260 0, /* properties_destroyed */
261 0, /* todo_flags_start */
262 0, /* todo_flags_finish */
265 class pass_ipa_oacc_kernels : public simple_ipa_opt_pass
267 public:
268 pass_ipa_oacc_kernels (gcc::context *ctxt)
269 : simple_ipa_opt_pass (pass_data_ipa_oacc_kernels, ctxt)
272 }; // class pass_ipa_oacc_kernels
274 } // anon namespace
276 simple_ipa_opt_pass *
277 make_pass_ipa_oacc_kernels (gcc::context *ctxt)
279 return new pass_ipa_oacc_kernels (ctxt);
282 /* The no-loop superpass. */
284 namespace {
286 const pass_data pass_data_tree_no_loop =
288 GIMPLE_PASS, /* type */
289 "no_loop", /* name */
290 OPTGROUP_NONE, /* optinfo_flags */
291 TV_TREE_NOLOOP, /* tv_id */
292 PROP_cfg, /* properties_required */
293 0, /* properties_provided */
294 0, /* properties_destroyed */
295 0, /* todo_flags_start */
296 0, /* todo_flags_finish */
299 class pass_tree_no_loop : public gimple_opt_pass
301 public:
302 pass_tree_no_loop (gcc::context *ctxt)
303 : gimple_opt_pass (pass_data_tree_no_loop, ctxt)
306 /* opt_pass methods: */
307 virtual bool gate (function *fn) { return !gate_loop (fn); }
309 }; // class pass_tree_no_loop
311 } // anon namespace
313 gimple_opt_pass *
314 make_pass_tree_no_loop (gcc::context *ctxt)
316 return new pass_tree_no_loop (ctxt);
320 /* Loop optimizer initialization. */
322 namespace {
324 const pass_data pass_data_tree_loop_init =
326 GIMPLE_PASS, /* type */
327 "loopinit", /* name */
328 OPTGROUP_LOOP, /* optinfo_flags */
329 TV_NONE, /* tv_id */
330 PROP_cfg, /* properties_required */
331 0, /* properties_provided */
332 0, /* properties_destroyed */
333 0, /* todo_flags_start */
334 0, /* todo_flags_finish */
337 class pass_tree_loop_init : public gimple_opt_pass
339 public:
340 pass_tree_loop_init (gcc::context *ctxt)
341 : gimple_opt_pass (pass_data_tree_loop_init, ctxt)
344 /* opt_pass methods: */
345 virtual unsigned int execute (function *);
347 }; // class pass_tree_loop_init
349 unsigned int
350 pass_tree_loop_init::execute (function *fun ATTRIBUTE_UNUSED)
352 /* When processing a loop in the loop pipeline, we should be able to assert
353 that:
354 (loops_state_satisfies_p (LOOPS_NORMAL | LOOPS_HAVE_RECORDED_EXITS
355 | LOOP_CLOSED_SSA)
356 && scev_initialized_p ())
358 loop_optimizer_init (LOOPS_NORMAL
359 | LOOPS_HAVE_RECORDED_EXITS);
360 rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
361 scev_initialize ();
363 return 0;
366 } // anon namespace
368 gimple_opt_pass *
369 make_pass_tree_loop_init (gcc::context *ctxt)
371 return new pass_tree_loop_init (ctxt);
374 /* Loop autovectorization. */
376 namespace {
378 const pass_data pass_data_vectorize =
380 GIMPLE_PASS, /* type */
381 "vect", /* name */
382 OPTGROUP_LOOP | OPTGROUP_VEC, /* optinfo_flags */
383 TV_TREE_VECTORIZATION, /* tv_id */
384 ( PROP_cfg | PROP_ssa ), /* properties_required */
385 0, /* properties_provided */
386 0, /* properties_destroyed */
387 0, /* todo_flags_start */
388 0, /* todo_flags_finish */
391 class pass_vectorize : public gimple_opt_pass
393 public:
394 pass_vectorize (gcc::context *ctxt)
395 : gimple_opt_pass (pass_data_vectorize, ctxt)
398 /* opt_pass methods: */
399 virtual bool gate (function *fun)
401 return flag_tree_loop_vectorize || fun->has_force_vectorize_loops;
404 virtual unsigned int execute (function *);
406 }; // class pass_vectorize
408 unsigned int
409 pass_vectorize::execute (function *fun)
411 if (number_of_loops (fun) <= 1)
412 return 0;
414 return vectorize_loops ();
417 } // anon namespace
419 gimple_opt_pass *
420 make_pass_vectorize (gcc::context *ctxt)
422 return new pass_vectorize (ctxt);
425 /* Propagation of constants using scev. */
427 namespace {
429 const pass_data pass_data_scev_cprop =
431 GIMPLE_PASS, /* type */
432 "sccp", /* name */
433 OPTGROUP_LOOP, /* optinfo_flags */
434 TV_SCEV_CONST, /* tv_id */
435 ( PROP_cfg | PROP_ssa ), /* properties_required */
436 0, /* properties_provided */
437 0, /* properties_destroyed */
438 0, /* todo_flags_start */
439 ( TODO_cleanup_cfg
440 | TODO_update_ssa_only_virtuals ), /* todo_flags_finish */
443 class pass_scev_cprop : public gimple_opt_pass
445 public:
446 pass_scev_cprop (gcc::context *ctxt)
447 : gimple_opt_pass (pass_data_scev_cprop, ctxt)
450 /* opt_pass methods: */
451 virtual bool gate (function *) { return flag_tree_scev_cprop; }
452 virtual unsigned int execute (function *) { return scev_const_prop (); }
454 }; // class pass_scev_cprop
456 } // anon namespace
458 gimple_opt_pass *
459 make_pass_scev_cprop (gcc::context *ctxt)
461 return new pass_scev_cprop (ctxt);
464 /* Induction variable optimizations. */
466 namespace {
468 const pass_data pass_data_iv_optimize =
470 GIMPLE_PASS, /* type */
471 "ivopts", /* name */
472 OPTGROUP_LOOP, /* optinfo_flags */
473 TV_TREE_LOOP_IVOPTS, /* tv_id */
474 ( PROP_cfg | PROP_ssa ), /* properties_required */
475 0, /* properties_provided */
476 0, /* properties_destroyed */
477 0, /* todo_flags_start */
478 TODO_update_ssa, /* todo_flags_finish */
481 class pass_iv_optimize : public gimple_opt_pass
483 public:
484 pass_iv_optimize (gcc::context *ctxt)
485 : gimple_opt_pass (pass_data_iv_optimize, ctxt)
488 /* opt_pass methods: */
489 virtual bool gate (function *) { return flag_ivopts != 0; }
490 virtual unsigned int execute (function *);
492 }; // class pass_iv_optimize
494 unsigned int
495 pass_iv_optimize::execute (function *fun)
497 if (number_of_loops (fun) <= 1)
498 return 0;
500 tree_ssa_iv_optimize ();
501 return 0;
504 } // anon namespace
506 gimple_opt_pass *
507 make_pass_iv_optimize (gcc::context *ctxt)
509 return new pass_iv_optimize (ctxt);
512 /* Loop optimizer finalization. */
514 static unsigned int
515 tree_ssa_loop_done (void)
517 free_numbers_of_iterations_estimates (cfun);
518 scev_finalize ();
519 loop_optimizer_finalize ();
520 return 0;
523 namespace {
525 const pass_data pass_data_tree_loop_done =
527 GIMPLE_PASS, /* type */
528 "loopdone", /* name */
529 OPTGROUP_LOOP, /* optinfo_flags */
530 TV_NONE, /* tv_id */
531 PROP_cfg, /* properties_required */
532 0, /* properties_provided */
533 0, /* properties_destroyed */
534 0, /* todo_flags_start */
535 TODO_cleanup_cfg, /* todo_flags_finish */
538 class pass_tree_loop_done : public gimple_opt_pass
540 public:
541 pass_tree_loop_done (gcc::context *ctxt)
542 : gimple_opt_pass (pass_data_tree_loop_done, ctxt)
545 /* opt_pass methods: */
546 virtual unsigned int execute (function *) { return tree_ssa_loop_done (); }
548 }; // class pass_tree_loop_done
550 } // anon namespace
552 gimple_opt_pass *
553 make_pass_tree_loop_done (gcc::context *ctxt)
555 return new pass_tree_loop_done (ctxt);
558 /* Calls CBCK for each index in memory reference ADDR_P. There are two
559 kinds situations handled; in each of these cases, the memory reference
560 and DATA are passed to the callback:
562 Access to an array: ARRAY_{RANGE_}REF (base, index). In this case we also
563 pass the pointer to the index to the callback.
565 Pointer dereference: INDIRECT_REF (addr). In this case we also pass the
566 pointer to addr to the callback.
568 If the callback returns false, the whole search stops and false is returned.
569 Otherwise the function returns true after traversing through the whole
570 reference *ADDR_P. */
572 bool
573 for_each_index (tree *addr_p, bool (*cbck) (tree, tree *, void *), void *data)
575 tree *nxt, *idx;
577 for (; ; addr_p = nxt)
579 switch (TREE_CODE (*addr_p))
581 case SSA_NAME:
582 return cbck (*addr_p, addr_p, data);
584 case MEM_REF:
585 nxt = &TREE_OPERAND (*addr_p, 0);
586 return cbck (*addr_p, nxt, data);
588 case BIT_FIELD_REF:
589 case VIEW_CONVERT_EXPR:
590 case REALPART_EXPR:
591 case IMAGPART_EXPR:
592 nxt = &TREE_OPERAND (*addr_p, 0);
593 break;
595 case COMPONENT_REF:
596 /* If the component has varying offset, it behaves like index
597 as well. */
598 idx = &TREE_OPERAND (*addr_p, 2);
599 if (*idx
600 && !cbck (*addr_p, idx, data))
601 return false;
603 nxt = &TREE_OPERAND (*addr_p, 0);
604 break;
606 case ARRAY_REF:
607 case ARRAY_RANGE_REF:
608 nxt = &TREE_OPERAND (*addr_p, 0);
609 if (!cbck (*addr_p, &TREE_OPERAND (*addr_p, 1), data))
610 return false;
611 break;
613 case VAR_DECL:
614 case PARM_DECL:
615 case CONST_DECL:
616 case STRING_CST:
617 case RESULT_DECL:
618 case VECTOR_CST:
619 case COMPLEX_CST:
620 case INTEGER_CST:
621 case POLY_INT_CST:
622 case REAL_CST:
623 case FIXED_CST:
624 case CONSTRUCTOR:
625 return true;
627 case ADDR_EXPR:
628 gcc_assert (is_gimple_min_invariant (*addr_p));
629 return true;
631 case TARGET_MEM_REF:
632 idx = &TMR_BASE (*addr_p);
633 if (*idx
634 && !cbck (*addr_p, idx, data))
635 return false;
636 idx = &TMR_INDEX (*addr_p);
637 if (*idx
638 && !cbck (*addr_p, idx, data))
639 return false;
640 idx = &TMR_INDEX2 (*addr_p);
641 if (*idx
642 && !cbck (*addr_p, idx, data))
643 return false;
644 return true;
646 default:
647 gcc_unreachable ();
653 /* The name and the length of the currently generated variable
654 for lsm. */
655 #define MAX_LSM_NAME_LENGTH 40
656 static char lsm_tmp_name[MAX_LSM_NAME_LENGTH + 1];
657 static int lsm_tmp_name_length;
659 /* Adds S to lsm_tmp_name. */
661 static void
662 lsm_tmp_name_add (const char *s)
664 int l = strlen (s) + lsm_tmp_name_length;
665 if (l > MAX_LSM_NAME_LENGTH)
666 return;
668 strcpy (lsm_tmp_name + lsm_tmp_name_length, s);
669 lsm_tmp_name_length = l;
672 /* Stores the name for temporary variable that replaces REF to
673 lsm_tmp_name. */
675 static void
676 gen_lsm_tmp_name (tree ref)
678 const char *name;
680 switch (TREE_CODE (ref))
682 case MEM_REF:
683 case TARGET_MEM_REF:
684 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
685 lsm_tmp_name_add ("_");
686 break;
688 case ADDR_EXPR:
689 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
690 break;
692 case BIT_FIELD_REF:
693 case VIEW_CONVERT_EXPR:
694 case ARRAY_RANGE_REF:
695 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
696 break;
698 case REALPART_EXPR:
699 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
700 lsm_tmp_name_add ("_RE");
701 break;
703 case IMAGPART_EXPR:
704 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
705 lsm_tmp_name_add ("_IM");
706 break;
708 case COMPONENT_REF:
709 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
710 lsm_tmp_name_add ("_");
711 name = get_name (TREE_OPERAND (ref, 1));
712 if (!name)
713 name = "F";
714 lsm_tmp_name_add (name);
715 break;
717 case ARRAY_REF:
718 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
719 lsm_tmp_name_add ("_I");
720 break;
722 case SSA_NAME:
723 case VAR_DECL:
724 case PARM_DECL:
725 case FUNCTION_DECL:
726 case LABEL_DECL:
727 name = get_name (ref);
728 if (!name)
729 name = "D";
730 lsm_tmp_name_add (name);
731 break;
733 case STRING_CST:
734 lsm_tmp_name_add ("S");
735 break;
737 case RESULT_DECL:
738 lsm_tmp_name_add ("R");
739 break;
741 case INTEGER_CST:
742 default:
743 /* Nothing. */
744 break;
748 /* Determines name for temporary variable that replaces REF.
749 The name is accumulated into the lsm_tmp_name variable.
750 N is added to the name of the temporary. */
752 char *
753 get_lsm_tmp_name (tree ref, unsigned n, const char *suffix)
755 char ns[2];
757 lsm_tmp_name_length = 0;
758 gen_lsm_tmp_name (ref);
759 lsm_tmp_name_add ("_lsm");
760 if (n < 10)
762 ns[0] = '0' + n;
763 ns[1] = 0;
764 lsm_tmp_name_add (ns);
766 return lsm_tmp_name;
767 if (suffix != NULL)
768 lsm_tmp_name_add (suffix);
771 /* Computes an estimated number of insns in LOOP, weighted by WEIGHTS. */
773 unsigned
774 tree_num_loop_insns (struct loop *loop, eni_weights *weights)
776 basic_block *body = get_loop_body (loop);
777 gimple_stmt_iterator gsi;
778 unsigned size = 0, i;
780 for (i = 0; i < loop->num_nodes; i++)
781 for (gsi = gsi_start_bb (body[i]); !gsi_end_p (gsi); gsi_next (&gsi))
782 size += estimate_num_insns (gsi_stmt (gsi), weights);
783 free (body);
785 return size;