1 /* Single entry single exit control flow regions.
2 Copyright (C) 2008, 2009, 2010
3 Free Software Foundation, Inc.
4 Contributed by Jan Sjodin <jan.sjodin@amd.com> and
5 Sebastian Pop <sebastian.pop@amd.com>.
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3, or (at your option)
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
25 #include "coretypes.h"
30 #include "basic-block.h"
31 #include "diagnostic.h"
32 #include "tree-pretty-print.h"
33 #include "tree-flow.h"
34 #include "tree-dump.h"
37 #include "tree-chrec.h"
38 #include "tree-data-ref.h"
39 #include "tree-scalar-evolution.h"
40 #include "tree-pass.h"
42 #include "value-prof.h"
43 #include "pointer-set.h"
47 /* Print to stderr the element ELT. */
50 debug_rename_elt (rename_map_elt elt)
52 fprintf (stderr, "(");
53 print_generic_expr (stderr, elt->old_name, 0);
54 fprintf (stderr, ", ");
55 print_generic_expr (stderr, elt->expr, 0);
56 fprintf (stderr, ")\n");
59 /* Helper function for debug_rename_map. */
62 debug_rename_map_1 (void **slot, void *s ATTRIBUTE_UNUSED)
64 struct rename_map_elt_s *entry = (struct rename_map_elt_s *) *slot;
65 debug_rename_elt (entry);
69 /* Print to stderr all the elements of RENAME_MAP. */
72 debug_rename_map (htab_t rename_map)
74 htab_traverse (rename_map, debug_rename_map_1, NULL);
77 /* Computes a hash function for database element ELT. */
80 rename_map_elt_info (const void *elt)
82 return SSA_NAME_VERSION (((const struct rename_map_elt_s *) elt)->old_name);
85 /* Compares database elements E1 and E2. */
88 eq_rename_map_elts (const void *e1, const void *e2)
90 const struct rename_map_elt_s *elt1 = (const struct rename_map_elt_s *) e1;
91 const struct rename_map_elt_s *elt2 = (const struct rename_map_elt_s *) e2;
93 return (elt1->old_name == elt2->old_name);
98 /* Print to stderr the element ELT. */
101 debug_ivtype_elt (ivtype_map_elt elt)
103 fprintf (stderr, "(%s, ", elt->cloog_iv);
104 print_generic_expr (stderr, elt->type, 0);
105 fprintf (stderr, ")\n");
108 /* Helper function for debug_ivtype_map. */
111 debug_ivtype_map_1 (void **slot, void *s ATTRIBUTE_UNUSED)
113 struct ivtype_map_elt_s *entry = (struct ivtype_map_elt_s *) *slot;
114 debug_ivtype_elt (entry);
118 /* Print to stderr all the elements of MAP. */
121 debug_ivtype_map (htab_t map)
123 htab_traverse (map, debug_ivtype_map_1, NULL);
126 /* Computes a hash function for database element ELT. */
129 ivtype_map_elt_info (const void *elt)
131 return htab_hash_pointer (((const struct ivtype_map_elt_s *) elt)->cloog_iv);
134 /* Compares database elements E1 and E2. */
137 eq_ivtype_map_elts (const void *e1, const void *e2)
139 const struct ivtype_map_elt_s *elt1 = (const struct ivtype_map_elt_s *) e1;
140 const struct ivtype_map_elt_s *elt2 = (const struct ivtype_map_elt_s *) e2;
142 return (elt1->cloog_iv == elt2->cloog_iv);
147 /* Record LOOP as occuring in REGION. */
150 sese_record_loop (sese region, loop_p loop)
152 if (sese_contains_loop (region, loop))
155 bitmap_set_bit (SESE_LOOPS (region), loop->num);
156 VEC_safe_push (loop_p, heap, SESE_LOOP_NEST (region), loop);
159 /* Build the loop nests contained in REGION. Returns true when the
160 operation was successful. */
163 build_sese_loop_nests (sese region)
167 struct loop *loop0, *loop1;
170 if (bb_in_sese_p (bb, region))
172 struct loop *loop = bb->loop_father;
174 /* Only add loops if they are completely contained in the SCoP. */
175 if (loop->header == bb
176 && bb_in_sese_p (loop->latch, region))
177 sese_record_loop (region, loop);
180 /* Make sure that the loops in the SESE_LOOP_NEST are ordered. It
181 can be the case that an inner loop is inserted before an outer
182 loop. To avoid this, semi-sort once. */
183 FOR_EACH_VEC_ELT (loop_p, SESE_LOOP_NEST (region), i, loop0)
185 if (VEC_length (loop_p, SESE_LOOP_NEST (region)) == i + 1)
188 loop1 = VEC_index (loop_p, SESE_LOOP_NEST (region), i + 1);
189 if (loop0->num > loop1->num)
191 VEC_replace (loop_p, SESE_LOOP_NEST (region), i, loop1);
192 VEC_replace (loop_p, SESE_LOOP_NEST (region), i + 1, loop0);
197 /* For a USE in BB, if BB is outside REGION, mark the USE in the
201 sese_build_liveouts_use (sese region, bitmap liveouts, basic_block bb,
207 if (TREE_CODE (use) != SSA_NAME)
210 ver = SSA_NAME_VERSION (use);
211 def_bb = gimple_bb (SSA_NAME_DEF_STMT (use));
214 || !bb_in_sese_p (def_bb, region)
215 || bb_in_sese_p (bb, region))
218 bitmap_set_bit (liveouts, ver);
221 /* Marks for rewrite all the SSA_NAMES defined in REGION and that are
222 used in BB that is outside of the REGION. */
225 sese_build_liveouts_bb (sese region, bitmap liveouts, basic_block bb)
227 gimple_stmt_iterator bsi;
233 FOR_EACH_EDGE (e, ei, bb->succs)
234 for (bsi = gsi_start_phis (e->dest); !gsi_end_p (bsi); gsi_next (&bsi))
235 sese_build_liveouts_use (region, liveouts, bb,
236 PHI_ARG_DEF_FROM_EDGE (gsi_stmt (bsi), e));
238 for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
240 gimple stmt = gsi_stmt (bsi);
242 if (is_gimple_debug (stmt))
245 FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_ALL_USES)
246 sese_build_liveouts_use (region, liveouts, bb, USE_FROM_PTR (use_p));
250 /* For a USE in BB, return true if BB is outside REGION and it's not
251 in the LIVEOUTS set. */
254 sese_bad_liveouts_use (sese region, bitmap liveouts, basic_block bb,
260 if (TREE_CODE (use) != SSA_NAME)
263 ver = SSA_NAME_VERSION (use);
265 /* If it's in liveouts, the variable will get a new PHI node, and
266 the debug use will be properly adjusted. */
267 if (bitmap_bit_p (liveouts, ver))
270 def_bb = gimple_bb (SSA_NAME_DEF_STMT (use));
273 || !bb_in_sese_p (def_bb, region)
274 || bb_in_sese_p (bb, region))
280 /* Reset debug stmts that reference SSA_NAMES defined in REGION that
281 are not marked as liveouts. */
284 sese_reset_debug_liveouts_bb (sese region, bitmap liveouts, basic_block bb)
286 gimple_stmt_iterator bsi;
290 for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
292 gimple stmt = gsi_stmt (bsi);
294 if (!is_gimple_debug (stmt))
297 FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_ALL_USES)
298 if (sese_bad_liveouts_use (region, liveouts, bb,
299 USE_FROM_PTR (use_p)))
301 gimple_debug_bind_reset_value (stmt);
308 /* Build the LIVEOUTS of REGION: the set of variables defined inside
309 and used outside the REGION. */
312 sese_build_liveouts (sese region, bitmap liveouts)
317 sese_build_liveouts_bb (region, liveouts, bb);
318 if (MAY_HAVE_DEBUG_INSNS)
320 sese_reset_debug_liveouts_bb (region, liveouts, bb);
323 /* Builds a new SESE region from edges ENTRY and EXIT. */
326 new_sese (edge entry, edge exit)
328 sese region = XNEW (struct sese_s);
330 SESE_ENTRY (region) = entry;
331 SESE_EXIT (region) = exit;
332 SESE_LOOPS (region) = BITMAP_ALLOC (NULL);
333 SESE_LOOP_NEST (region) = VEC_alloc (loop_p, heap, 3);
334 SESE_ADD_PARAMS (region) = true;
335 SESE_PARAMS (region) = VEC_alloc (tree, heap, 3);
340 /* Deletes REGION. */
343 free_sese (sese region)
345 if (SESE_LOOPS (region))
346 SESE_LOOPS (region) = BITMAP_ALLOC (NULL);
348 VEC_free (tree, heap, SESE_PARAMS (region));
349 VEC_free (loop_p, heap, SESE_LOOP_NEST (region));
354 /* Add exit phis for USE on EXIT. */
357 sese_add_exit_phis_edge (basic_block exit, tree use, edge false_e, edge true_e)
359 gimple phi = create_phi_node (use, exit);
361 create_new_def_for (gimple_phi_result (phi), phi,
362 gimple_phi_result_ptr (phi));
363 add_phi_arg (phi, use, false_e, UNKNOWN_LOCATION);
364 add_phi_arg (phi, use, true_e, UNKNOWN_LOCATION);
367 /* Insert in the block BB phi nodes for variables defined in REGION
368 and used outside the REGION. The code generation moves REGION in
369 the else clause of an "if (1)" and generates code in the then
370 clause that is at this point empty:
379 sese_insert_phis_for_liveouts (sese region, basic_block bb,
380 edge false_e, edge true_e)
384 bitmap liveouts = BITMAP_ALLOC (NULL);
386 update_ssa (TODO_update_ssa);
388 sese_build_liveouts (region, liveouts);
389 EXECUTE_IF_SET_IN_BITMAP (liveouts, 0, i, bi)
390 sese_add_exit_phis_edge (bb, ssa_name (i), false_e, true_e);
391 BITMAP_FREE (liveouts);
393 update_ssa (TODO_update_ssa);
396 /* Returns the first successor edge of BB with EDGE_TRUE_VALUE flag set. */
399 get_true_edge_from_guard_bb (basic_block bb)
404 FOR_EACH_EDGE (e, ei, bb->succs)
405 if (e->flags & EDGE_TRUE_VALUE)
412 /* Returns the first successor edge of BB with EDGE_TRUE_VALUE flag cleared. */
415 get_false_edge_from_guard_bb (basic_block bb)
420 FOR_EACH_EDGE (e, ei, bb->succs)
421 if (!(e->flags & EDGE_TRUE_VALUE))
428 /* Returns the expression associated to OLD_NAME in RENAME_MAP. */
431 get_rename (htab_t rename_map, tree old_name)
433 struct rename_map_elt_s tmp;
436 gcc_assert (TREE_CODE (old_name) == SSA_NAME);
437 tmp.old_name = old_name;
438 slot = htab_find_slot (rename_map, &tmp, NO_INSERT);
441 return ((rename_map_elt) *slot)->expr;
446 /* Register in RENAME_MAP the rename tuple (OLD_NAME, EXPR). */
449 set_rename (htab_t rename_map, tree old_name, tree expr)
451 struct rename_map_elt_s tmp;
454 if (old_name == expr)
457 tmp.old_name = old_name;
458 slot = htab_find_slot (rename_map, &tmp, INSERT);
466 *slot = new_rename_map_elt (old_name, expr);
469 /* Renames the scalar uses of the statement COPY, using the
470 substitution map RENAME_MAP, inserting the gimplification code at
471 GSI_TGT, for the translation REGION, with the original copied
472 statement in LOOP, and using the induction variable renaming map
476 rename_uses (gimple copy, htab_t rename_map, gimple_stmt_iterator *gsi_tgt,
477 sese region, loop_p loop, VEC (tree, heap) *iv_map)
482 if (is_gimple_debug (copy))
484 if (gimple_debug_bind_p (copy))
485 gimple_debug_bind_reset_value (copy);
492 FOR_EACH_SSA_USE_OPERAND (use_p, copy, op_iter, SSA_OP_ALL_USES)
494 tree old_name = USE_FROM_PTR (use_p);
498 if (TREE_CODE (old_name) != SSA_NAME
499 || !is_gimple_reg (old_name)
500 || SSA_NAME_IS_DEFAULT_DEF (old_name))
503 new_expr = get_rename (rename_map, old_name);
506 tree type_old_name = TREE_TYPE (old_name);
507 tree type_new_expr = TREE_TYPE (new_expr);
509 if (type_old_name != type_new_expr
510 || (TREE_CODE (new_expr) != SSA_NAME
511 && is_gimple_reg (old_name)))
513 tree var = create_tmp_var (type_old_name, "var");
515 if (type_old_name != type_new_expr)
516 new_expr = fold_convert (type_old_name, new_expr);
518 new_expr = build2 (MODIFY_EXPR, type_old_name, var, new_expr);
519 new_expr = force_gimple_operand (new_expr, &stmts, true, NULL);
520 gsi_insert_seq_before (gsi_tgt, stmts, GSI_SAME_STMT);
523 replace_exp (use_p, new_expr);
527 scev = scalar_evolution_in_region (region, loop, old_name);
529 /* At this point we should know the exact scev for each
530 scalar SSA_NAME used in the scop: all the other scalar
531 SSA_NAMEs should have been translated out of SSA using
532 arrays with one element. */
533 gcc_assert (!chrec_contains_undetermined (scev));
535 new_expr = chrec_apply_map (scev, iv_map);
537 /* The apply should produce an expression tree containing
538 the uses of the new induction variables. We should be
539 able to use new_expr instead of the old_name in the newly
540 generated loop nest. */
541 gcc_assert (!chrec_contains_undetermined (new_expr)
542 && !tree_contains_chrecs (new_expr, NULL));
544 /* Replace the old_name with the new_expr. */
545 new_expr = force_gimple_operand (unshare_expr (new_expr), &stmts,
547 gsi_insert_seq_before (gsi_tgt, stmts, GSI_SAME_STMT);
548 replace_exp (use_p, new_expr);
549 set_rename (rename_map, old_name, new_expr);
553 /* Duplicates the statements of basic block BB into basic block NEW_BB
554 and compute the new induction variables according to the IV_MAP. */
557 graphite_copy_stmts_from_block (basic_block bb, basic_block new_bb,
559 VEC (tree, heap) *iv_map, sese region)
561 gimple_stmt_iterator gsi, gsi_tgt;
562 loop_p loop = bb->loop_father;
564 gsi_tgt = gsi_start_bb (new_bb);
565 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
569 gimple stmt = gsi_stmt (gsi);
573 /* Do not copy labels or conditions. */
574 if (gimple_code (stmt) == GIMPLE_LABEL
575 || gimple_code (stmt) == GIMPLE_COND)
578 /* Do not copy induction variables. */
579 if (is_gimple_assign (stmt)
580 && (lhs = gimple_assign_lhs (stmt))
581 && TREE_CODE (lhs) == SSA_NAME
582 && is_gimple_reg (lhs)
583 && scev_analyzable_p (lhs, region))
586 /* Create a new copy of STMT and duplicate STMT's virtual
588 copy = gimple_copy (stmt);
589 gsi_insert_after (&gsi_tgt, copy, GSI_NEW_STMT);
590 mark_sym_for_renaming (gimple_vop (cfun));
592 maybe_duplicate_eh_stmt (copy, stmt);
593 gimple_duplicate_stmt_histograms (cfun, copy, cfun, stmt);
595 /* Create new names for all the definitions created by COPY and
596 add replacement mappings for each new name. */
597 FOR_EACH_SSA_DEF_OPERAND (def_p, copy, op_iter, SSA_OP_ALL_DEFS)
599 tree old_name = DEF_FROM_PTR (def_p);
600 tree new_name = create_new_def_for (old_name, copy, def_p);
601 set_rename (rename_map, old_name, new_name);
604 rename_uses (copy, rename_map, &gsi_tgt, region, loop, iv_map);
610 /* Copies BB and includes in the copied BB all the statements that can
611 be reached following the use-def chains from the memory accesses,
612 and returns the next edge following this new block. */
615 copy_bb_and_scalar_dependences (basic_block bb, sese region,
616 edge next_e, VEC (tree, heap) *iv_map)
618 basic_block new_bb = split_edge (next_e);
619 htab_t rename_map = htab_create (10, rename_map_elt_info,
620 eq_rename_map_elts, free);
622 next_e = single_succ_edge (new_bb);
623 graphite_copy_stmts_from_block (bb, new_bb, rename_map, iv_map, region);
624 remove_phi_nodes (new_bb);
625 htab_delete (rename_map);
630 /* Returns the outermost loop in SCOP that contains BB. */
633 outermost_loop_in_sese (sese region, basic_block bb)
637 nest = bb->loop_father;
638 while (loop_outer (nest)
639 && loop_in_sese_p (loop_outer (nest), region))
640 nest = loop_outer (nest);
645 /* Sets the false region of an IF_REGION to REGION. */
648 if_region_set_false_region (ifsese if_region, sese region)
650 basic_block condition = if_region_get_condition_block (if_region);
651 edge false_edge = get_false_edge_from_guard_bb (condition);
652 basic_block dummy = false_edge->dest;
653 edge entry_region = SESE_ENTRY (region);
654 edge exit_region = SESE_EXIT (region);
655 basic_block before_region = entry_region->src;
656 basic_block last_in_region = exit_region->src;
657 void **slot = htab_find_slot_with_hash (current_loops->exits, exit_region,
658 htab_hash_pointer (exit_region),
661 entry_region->flags = false_edge->flags;
662 false_edge->flags = exit_region->flags;
664 redirect_edge_pred (entry_region, condition);
665 redirect_edge_pred (exit_region, before_region);
666 redirect_edge_pred (false_edge, last_in_region);
667 redirect_edge_succ (false_edge, single_succ (dummy));
668 delete_basic_block (dummy);
670 exit_region->flags = EDGE_FALLTHRU;
671 recompute_all_dominators ();
673 SESE_EXIT (region) = false_edge;
675 if (if_region->false_region)
676 free (if_region->false_region);
677 if_region->false_region = region;
681 struct loop_exit *loop_exit = ggc_alloc_cleared_loop_exit ();
683 memcpy (loop_exit, *((struct loop_exit **) slot), sizeof (struct loop_exit));
684 htab_clear_slot (current_loops->exits, slot);
686 slot = htab_find_slot_with_hash (current_loops->exits, false_edge,
687 htab_hash_pointer (false_edge),
689 loop_exit->e = false_edge;
691 false_edge->src->loop_father->exits->next = loop_exit;
695 /* Creates an IFSESE with CONDITION on edge ENTRY. */
698 create_if_region_on_edge (edge entry, tree condition)
702 sese sese_region = XNEW (struct sese_s);
703 sese true_region = XNEW (struct sese_s);
704 sese false_region = XNEW (struct sese_s);
705 ifsese if_region = XNEW (struct ifsese_s);
706 edge exit = create_empty_if_region_on_edge (entry, condition);
708 if_region->region = sese_region;
709 if_region->region->entry = entry;
710 if_region->region->exit = exit;
712 FOR_EACH_EDGE (e, ei, entry->dest->succs)
714 if (e->flags & EDGE_TRUE_VALUE)
716 true_region->entry = e;
717 true_region->exit = single_succ_edge (e->dest);
718 if_region->true_region = true_region;
720 else if (e->flags & EDGE_FALSE_VALUE)
722 false_region->entry = e;
723 false_region->exit = single_succ_edge (e->dest);
724 if_region->false_region = false_region;
731 /* Moves REGION in a condition expression:
739 move_sese_in_condition (sese region)
741 basic_block pred_block = split_edge (SESE_ENTRY (region));
744 SESE_ENTRY (region) = single_succ_edge (pred_block);
745 if_region = create_if_region_on_edge (single_pred_edge (pred_block), integer_one_node);
746 if_region_set_false_region (if_region, region);
751 /* Replaces the condition of the IF_REGION with CONDITION:
759 set_ifsese_condition (ifsese if_region, tree condition)
761 sese region = if_region->region;
762 edge entry = region->entry;
763 basic_block bb = entry->dest;
764 gimple last = last_stmt (bb);
765 gimple_stmt_iterator gsi = gsi_last_bb (bb);
768 gcc_assert (gimple_code (last) == GIMPLE_COND);
770 gsi_remove (&gsi, true);
771 gsi = gsi_last_bb (bb);
772 condition = force_gimple_operand_gsi (&gsi, condition, true, NULL,
773 false, GSI_NEW_STMT);
774 cond_stmt = gimple_build_cond_from_tree (condition, NULL_TREE, NULL_TREE);
775 gsi = gsi_last_bb (bb);
776 gsi_insert_after (&gsi, cond_stmt, GSI_NEW_STMT);
779 /* Returns the scalar evolution of T in REGION. Every variable that
780 is not defined in the REGION is considered a parameter. */
783 scalar_evolution_in_region (sese region, loop_p loop, tree t)
786 struct loop *def_loop;
787 basic_block before = block_before_sese (region);
789 if (TREE_CODE (t) != SSA_NAME
790 || loop_in_sese_p (loop, region))
791 return instantiate_scev (before, loop,
792 analyze_scalar_evolution (loop, t));
794 if (!defined_in_sese_p (t, region))
797 def = SSA_NAME_DEF_STMT (t);
798 def_loop = loop_containing_stmt (def);
800 if (loop_in_sese_p (def_loop, region))
802 t = analyze_scalar_evolution (def_loop, t);
803 def_loop = superloop_at_depth (def_loop, loop_depth (loop) + 1);
804 t = compute_overall_effect_of_inner_loop (def_loop, t);
808 return instantiate_scev (before, loop, t);