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[official-gcc.git] / gcc / tree-ssa-loop.c
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1 /* Loop optimizations over tree-ssa.
2 Copyright (C) 2003-2016 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 "tm_p.h"
28 #include "fold-const.h"
29 #include "gimple-iterator.h"
30 #include "tree-ssa-loop-ivopts.h"
31 #include "tree-ssa-loop-manip.h"
32 #include "tree-ssa-loop-niter.h"
33 #include "tree-ssa-loop.h"
34 #include "cfgloop.h"
35 #include "tree-inline.h"
36 #include "tree-scalar-evolution.h"
37 #include "tree-vectorizer.h"
38 #include "omp-low.h"
39 #include "diagnostic-core.h"
42 /* A pass making sure loops are fixed up. */
44 namespace {
46 const pass_data pass_data_fix_loops =
48 GIMPLE_PASS, /* type */
49 "fix_loops", /* name */
50 OPTGROUP_LOOP, /* optinfo_flags */
51 TV_TREE_LOOP, /* tv_id */
52 PROP_cfg, /* properties_required */
53 0, /* properties_provided */
54 0, /* properties_destroyed */
55 0, /* todo_flags_start */
56 0, /* todo_flags_finish */
59 class pass_fix_loops : public gimple_opt_pass
61 public:
62 pass_fix_loops (gcc::context *ctxt)
63 : gimple_opt_pass (pass_data_fix_loops, ctxt)
66 /* opt_pass methods: */
67 virtual bool gate (function *) { return flag_tree_loop_optimize; }
69 virtual unsigned int execute (function *fn);
70 }; // class pass_fix_loops
72 unsigned int
73 pass_fix_loops::execute (function *)
75 if (loops_state_satisfies_p (LOOPS_NEED_FIXUP))
77 calculate_dominance_info (CDI_DOMINATORS);
78 fix_loop_structure (NULL);
80 return 0;
83 } // anon namespace
85 gimple_opt_pass *
86 make_pass_fix_loops (gcc::context *ctxt)
88 return new pass_fix_loops (ctxt);
92 /* Gate for loop pass group. The group is controlled by -ftree-loop-optimize
93 but we also avoid running it when the IL doesn't contain any loop. */
95 static bool
96 gate_loop (function *fn)
98 if (!flag_tree_loop_optimize)
99 return false;
101 /* For -fdump-passes which runs before loop discovery print the
102 state of -ftree-loop-optimize. */
103 if (!loops_for_fn (fn))
104 return true;
106 return number_of_loops (fn) > 1;
109 /* The loop superpass. */
111 namespace {
113 const pass_data pass_data_tree_loop =
115 GIMPLE_PASS, /* type */
116 "loop", /* name */
117 OPTGROUP_LOOP, /* optinfo_flags */
118 TV_TREE_LOOP, /* tv_id */
119 PROP_cfg, /* properties_required */
120 0, /* properties_provided */
121 0, /* properties_destroyed */
122 0, /* todo_flags_start */
123 0, /* todo_flags_finish */
126 class pass_tree_loop : public gimple_opt_pass
128 public:
129 pass_tree_loop (gcc::context *ctxt)
130 : gimple_opt_pass (pass_data_tree_loop, ctxt)
133 /* opt_pass methods: */
134 virtual bool gate (function *fn) { return gate_loop (fn); }
136 }; // class pass_tree_loop
138 } // anon namespace
140 gimple_opt_pass *
141 make_pass_tree_loop (gcc::context *ctxt)
143 return new pass_tree_loop (ctxt);
146 /* Gate for oacc kernels pass group. */
148 static bool
149 gate_oacc_kernels (function *fn)
151 if (!flag_openacc)
152 return false;
154 tree oacc_function_attr = get_oacc_fn_attrib (fn->decl);
155 if (oacc_function_attr == NULL_TREE)
156 return false;
157 if (!oacc_fn_attrib_kernels_p (oacc_function_attr))
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 /* Record bounds on numbers of iterations of loops. */
466 namespace {
468 const pass_data pass_data_record_bounds =
470 GIMPLE_PASS, /* type */
471 "*record_bounds", /* name */
472 OPTGROUP_NONE, /* optinfo_flags */
473 TV_TREE_LOOP_BOUNDS, /* tv_id */
474 ( PROP_cfg | PROP_ssa ), /* properties_required */
475 0, /* properties_provided */
476 0, /* properties_destroyed */
477 0, /* todo_flags_start */
478 0, /* todo_flags_finish */
481 class pass_record_bounds : public gimple_opt_pass
483 public:
484 pass_record_bounds (gcc::context *ctxt)
485 : gimple_opt_pass (pass_data_record_bounds, ctxt)
488 /* opt_pass methods: */
489 virtual unsigned int execute (function *);
491 }; // class pass_record_bounds
493 unsigned int
494 pass_record_bounds::execute (function *fun)
496 if (number_of_loops (fun) <= 1)
497 return 0;
499 estimate_numbers_of_iterations ();
500 scev_reset ();
501 return 0;
504 } // anon namespace
506 gimple_opt_pass *
507 make_pass_record_bounds (gcc::context *ctxt)
509 return new pass_record_bounds (ctxt);
512 /* Induction variable optimizations. */
514 namespace {
516 const pass_data pass_data_iv_optimize =
518 GIMPLE_PASS, /* type */
519 "ivopts", /* name */
520 OPTGROUP_LOOP, /* optinfo_flags */
521 TV_TREE_LOOP_IVOPTS, /* tv_id */
522 ( PROP_cfg | PROP_ssa ), /* properties_required */
523 0, /* properties_provided */
524 0, /* properties_destroyed */
525 0, /* todo_flags_start */
526 TODO_update_ssa, /* todo_flags_finish */
529 class pass_iv_optimize : public gimple_opt_pass
531 public:
532 pass_iv_optimize (gcc::context *ctxt)
533 : gimple_opt_pass (pass_data_iv_optimize, ctxt)
536 /* opt_pass methods: */
537 virtual bool gate (function *) { return flag_ivopts != 0; }
538 virtual unsigned int execute (function *);
540 }; // class pass_iv_optimize
542 unsigned int
543 pass_iv_optimize::execute (function *fun)
545 if (number_of_loops (fun) <= 1)
546 return 0;
548 tree_ssa_iv_optimize ();
549 return 0;
552 } // anon namespace
554 gimple_opt_pass *
555 make_pass_iv_optimize (gcc::context *ctxt)
557 return new pass_iv_optimize (ctxt);
560 /* Loop optimizer finalization. */
562 static unsigned int
563 tree_ssa_loop_done (void)
565 free_numbers_of_iterations_estimates (cfun);
566 scev_finalize ();
567 loop_optimizer_finalize ();
568 return 0;
571 namespace {
573 const pass_data pass_data_tree_loop_done =
575 GIMPLE_PASS, /* type */
576 "loopdone", /* name */
577 OPTGROUP_LOOP, /* optinfo_flags */
578 TV_NONE, /* tv_id */
579 PROP_cfg, /* properties_required */
580 0, /* properties_provided */
581 0, /* properties_destroyed */
582 0, /* todo_flags_start */
583 TODO_cleanup_cfg, /* todo_flags_finish */
586 class pass_tree_loop_done : public gimple_opt_pass
588 public:
589 pass_tree_loop_done (gcc::context *ctxt)
590 : gimple_opt_pass (pass_data_tree_loop_done, ctxt)
593 /* opt_pass methods: */
594 virtual unsigned int execute (function *) { return tree_ssa_loop_done (); }
596 }; // class pass_tree_loop_done
598 } // anon namespace
600 gimple_opt_pass *
601 make_pass_tree_loop_done (gcc::context *ctxt)
603 return new pass_tree_loop_done (ctxt);
606 /* Calls CBCK for each index in memory reference ADDR_P. There are two
607 kinds situations handled; in each of these cases, the memory reference
608 and DATA are passed to the callback:
610 Access to an array: ARRAY_{RANGE_}REF (base, index). In this case we also
611 pass the pointer to the index to the callback.
613 Pointer dereference: INDIRECT_REF (addr). In this case we also pass the
614 pointer to addr to the callback.
616 If the callback returns false, the whole search stops and false is returned.
617 Otherwise the function returns true after traversing through the whole
618 reference *ADDR_P. */
620 bool
621 for_each_index (tree *addr_p, bool (*cbck) (tree, tree *, void *), void *data)
623 tree *nxt, *idx;
625 for (; ; addr_p = nxt)
627 switch (TREE_CODE (*addr_p))
629 case SSA_NAME:
630 return cbck (*addr_p, addr_p, data);
632 case MEM_REF:
633 nxt = &TREE_OPERAND (*addr_p, 0);
634 return cbck (*addr_p, nxt, data);
636 case BIT_FIELD_REF:
637 case VIEW_CONVERT_EXPR:
638 case REALPART_EXPR:
639 case IMAGPART_EXPR:
640 nxt = &TREE_OPERAND (*addr_p, 0);
641 break;
643 case COMPONENT_REF:
644 /* If the component has varying offset, it behaves like index
645 as well. */
646 idx = &TREE_OPERAND (*addr_p, 2);
647 if (*idx
648 && !cbck (*addr_p, idx, data))
649 return false;
651 nxt = &TREE_OPERAND (*addr_p, 0);
652 break;
654 case ARRAY_REF:
655 case ARRAY_RANGE_REF:
656 nxt = &TREE_OPERAND (*addr_p, 0);
657 if (!cbck (*addr_p, &TREE_OPERAND (*addr_p, 1), data))
658 return false;
659 break;
661 case VAR_DECL:
662 case PARM_DECL:
663 case CONST_DECL:
664 case STRING_CST:
665 case RESULT_DECL:
666 case VECTOR_CST:
667 case COMPLEX_CST:
668 case INTEGER_CST:
669 case REAL_CST:
670 case FIXED_CST:
671 case CONSTRUCTOR:
672 return true;
674 case ADDR_EXPR:
675 gcc_assert (is_gimple_min_invariant (*addr_p));
676 return true;
678 case TARGET_MEM_REF:
679 idx = &TMR_BASE (*addr_p);
680 if (*idx
681 && !cbck (*addr_p, idx, data))
682 return false;
683 idx = &TMR_INDEX (*addr_p);
684 if (*idx
685 && !cbck (*addr_p, idx, data))
686 return false;
687 idx = &TMR_INDEX2 (*addr_p);
688 if (*idx
689 && !cbck (*addr_p, idx, data))
690 return false;
691 return true;
693 default:
694 gcc_unreachable ();
700 /* The name and the length of the currently generated variable
701 for lsm. */
702 #define MAX_LSM_NAME_LENGTH 40
703 static char lsm_tmp_name[MAX_LSM_NAME_LENGTH + 1];
704 static int lsm_tmp_name_length;
706 /* Adds S to lsm_tmp_name. */
708 static void
709 lsm_tmp_name_add (const char *s)
711 int l = strlen (s) + lsm_tmp_name_length;
712 if (l > MAX_LSM_NAME_LENGTH)
713 return;
715 strcpy (lsm_tmp_name + lsm_tmp_name_length, s);
716 lsm_tmp_name_length = l;
719 /* Stores the name for temporary variable that replaces REF to
720 lsm_tmp_name. */
722 static void
723 gen_lsm_tmp_name (tree ref)
725 const char *name;
727 switch (TREE_CODE (ref))
729 case MEM_REF:
730 case TARGET_MEM_REF:
731 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
732 lsm_tmp_name_add ("_");
733 break;
735 case ADDR_EXPR:
736 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
737 break;
739 case BIT_FIELD_REF:
740 case VIEW_CONVERT_EXPR:
741 case ARRAY_RANGE_REF:
742 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
743 break;
745 case REALPART_EXPR:
746 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
747 lsm_tmp_name_add ("_RE");
748 break;
750 case IMAGPART_EXPR:
751 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
752 lsm_tmp_name_add ("_IM");
753 break;
755 case COMPONENT_REF:
756 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
757 lsm_tmp_name_add ("_");
758 name = get_name (TREE_OPERAND (ref, 1));
759 if (!name)
760 name = "F";
761 lsm_tmp_name_add (name);
762 break;
764 case ARRAY_REF:
765 gen_lsm_tmp_name (TREE_OPERAND (ref, 0));
766 lsm_tmp_name_add ("_I");
767 break;
769 case SSA_NAME:
770 case VAR_DECL:
771 case PARM_DECL:
772 case FUNCTION_DECL:
773 case LABEL_DECL:
774 name = get_name (ref);
775 if (!name)
776 name = "D";
777 lsm_tmp_name_add (name);
778 break;
780 case STRING_CST:
781 lsm_tmp_name_add ("S");
782 break;
784 case RESULT_DECL:
785 lsm_tmp_name_add ("R");
786 break;
788 case INTEGER_CST:
789 default:
790 /* Nothing. */
791 break;
795 /* Determines name for temporary variable that replaces REF.
796 The name is accumulated into the lsm_tmp_name variable.
797 N is added to the name of the temporary. */
799 char *
800 get_lsm_tmp_name (tree ref, unsigned n, const char *suffix)
802 char ns[2];
804 lsm_tmp_name_length = 0;
805 gen_lsm_tmp_name (ref);
806 lsm_tmp_name_add ("_lsm");
807 if (n < 10)
809 ns[0] = '0' + n;
810 ns[1] = 0;
811 lsm_tmp_name_add (ns);
813 return lsm_tmp_name;
814 if (suffix != NULL)
815 lsm_tmp_name_add (suffix);
818 /* Computes an estimated number of insns in LOOP, weighted by WEIGHTS. */
820 unsigned
821 tree_num_loop_insns (struct loop *loop, eni_weights *weights)
823 basic_block *body = get_loop_body (loop);
824 gimple_stmt_iterator gsi;
825 unsigned size = 0, i;
827 for (i = 0; i < loop->num_nodes; i++)
828 for (gsi = gsi_start_bb (body[i]); !gsi_end_p (gsi); gsi_next (&gsi))
829 size += estimate_num_insns (gsi_stmt (gsi), weights);
830 free (body);
832 return size;