1 /* Detection of Static Control Parts (SCoP) for Graphite.
2 Copyright (C) 2009 Free Software Foundation, Inc.
3 Contributed by Sebastian Pop <sebastian.pop@amd.com> and
4 Tobias Grosser <grosser@fim.uni-passau.de>.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
29 #include "basic-block.h"
30 #include "diagnostic.h"
31 #include "tree-flow.h"
33 #include "tree-dump.h"
36 #include "tree-chrec.h"
37 #include "tree-data-ref.h"
38 #include "tree-scalar-evolution.h"
39 #include "tree-pass.h"
41 #include "value-prof.h"
42 #include "pointer-set.h"
47 #include "cloog/cloog.h"
49 #include "graphite-ppl.h"
51 #include "graphite-poly.h"
52 #include "graphite-scop-detection.h"
54 /* The type of the analyzed basic block. */
56 typedef enum gbb_type {
58 GBB_LOOP_SING_EXIT_HEADER,
59 GBB_LOOP_MULT_EXIT_HEADER,
66 /* Detect the type of BB. Loop headers are only marked, if they are
67 new. This means their loop_father is different to LAST_LOOP.
68 Otherwise they are treated like any other bb and their type can be
72 get_bb_type (basic_block bb, struct loop *last_loop)
74 VEC (basic_block, heap) *dom;
76 struct loop *loop = bb->loop_father;
78 /* Check, if we entry into a new loop. */
79 if (loop != last_loop)
81 if (single_exit (loop) != NULL)
82 return GBB_LOOP_SING_EXIT_HEADER;
83 else if (loop->num != 0)
84 return GBB_LOOP_MULT_EXIT_HEADER;
86 return GBB_COND_HEADER;
89 dom = get_dominated_by (CDI_DOMINATORS, bb);
90 nb_dom = VEC_length (basic_block, dom);
91 VEC_free (basic_block, heap, dom);
96 nb_suc = VEC_length (edge, bb->succs);
98 if (nb_dom == 1 && nb_suc == 1)
101 return GBB_COND_HEADER;
104 /* A SCoP detection region, defined using bbs as borders.
106 All control flow touching this region, comes in passing basic_block
107 ENTRY and leaves passing basic_block EXIT. By using bbs instead of
108 edges for the borders we are able to represent also regions that do
109 not have a single entry or exit edge.
111 But as they have a single entry basic_block and a single exit
112 basic_block, we are able to generate for every sd_region a single
120 / \ This region contains: {3, 4, 5, 6, 7, 8}
128 typedef struct sd_region_p
130 /* The entry bb dominates all bbs in the sd_region. It is part of
134 /* The exit bb postdominates all bbs in the sd_region, but is not
135 part of the region. */
139 DEF_VEC_O(sd_region);
140 DEF_VEC_ALLOC_O(sd_region, heap);
143 /* Moves the scops from SOURCE to TARGET and clean up SOURCE. */
146 move_sd_regions (VEC (sd_region, heap) **source,
147 VEC (sd_region, heap) **target)
152 for (i = 0; VEC_iterate (sd_region, *source, i, s); i++)
153 VEC_safe_push (sd_region, heap, *target, s);
155 VEC_free (sd_region, heap, *source);
158 /* Something like "n * m" is not allowed. */
161 graphite_can_represent_init (tree e)
163 switch (TREE_CODE (e))
165 case POLYNOMIAL_CHREC:
166 return graphite_can_represent_init (CHREC_LEFT (e))
167 && graphite_can_represent_init (CHREC_RIGHT (e));
170 if (chrec_contains_symbols (TREE_OPERAND (e, 0)))
171 return host_integerp (TREE_OPERAND (e, 1), 0);
173 return host_integerp (TREE_OPERAND (e, 0), 0);
176 case POINTER_PLUS_EXPR:
178 return graphite_can_represent_init (TREE_OPERAND (e, 0))
179 && graphite_can_represent_init (TREE_OPERAND (e, 1));
184 case NON_LVALUE_EXPR:
185 return graphite_can_represent_init (TREE_OPERAND (e, 0));
194 /* Return true when SCEV can be represented in the polyhedral model.
196 An expression can be represented, if it can be expressed as an
197 affine expression. For loops (i, j) and parameters (m, n) all
198 affine expressions are of the form:
200 x1 * i + x2 * j + x3 * m + x4 * n + x5 * 1 where x1..x5 element of Z
202 1 i + 20 j + (-2) m + 25
204 Something like "i * n" or "n * m" is not allowed.
206 OUTERMOST_LOOP defines the outermost loop that can variate. */
209 graphite_can_represent_scev (tree scev, int outermost_loop)
211 if (chrec_contains_undetermined (scev))
214 if (TREE_CODE (scev) == POLYNOMIAL_CHREC
216 /* Check for constant strides. With a non constant stride of
217 'n' we would have a value of 'iv * n'. */
218 && (!evolution_function_right_is_integer_cst (scev)
220 /* Check the initial value: 'n * m' cannot be represented. */
221 || !graphite_can_represent_init (scev)))
224 /* Only affine functions can be represented. */
225 if (!scev_is_linear_expression (scev))
228 return evolution_function_is_invariant_p (scev, outermost_loop)
229 || evolution_function_is_affine_multivariate_p (scev, outermost_loop);
233 /* Return true when EXPR can be represented in the polyhedral model.
235 This means an expression can be represented, if it is linear with
236 respect to the loops and the strides are non parametric.
237 LOOP is the place where the expr will be evaluated and OUTERMOST_LOOP
238 defindes the outermost loop that can variate. SCOP_ENTRY defines the
239 entry of the region we analyse. */
242 graphite_can_represent_expr (basic_block scop_entry, loop_p loop,
243 loop_p outermost_loop, tree expr)
245 tree scev = analyze_scalar_evolution (loop, expr);
247 scev = instantiate_scev (scop_entry, loop, scev);
249 return graphite_can_represent_scev (scev, outermost_loop->num);
252 /* Return false if the tree_code of the operand OP or any of its operands
256 exclude_component_ref (tree op)
264 if (TREE_CODE (op) == COMPONENT_REF)
267 len = TREE_OPERAND_LENGTH (op);
268 for (i = 0; i < len; ++i)
269 if (!exclude_component_ref (TREE_OPERAND (op, i)))
275 /* Return true if the data references of STMT can be represented by
279 stmt_has_simple_data_refs_p (loop_p outermost_loop, gimple stmt)
285 int loop = outermost_loop->num;
286 VEC (data_reference_p, heap) *drs = VEC_alloc (data_reference_p, heap, 5);
288 graphite_find_data_references_in_stmt (outermost_loop, stmt, &drs);
290 for (j = 0; VEC_iterate (data_reference_p, drs, j, dr); j++)
291 for (i = 0; i < DR_NUM_DIMENSIONS (dr); i++)
292 if (!graphite_can_represent_scev (DR_ACCESS_FN (dr, i), loop))
299 free_data_refs (drs);
303 /* Return true if we can create an affine data-ref for OP in STMT
304 in regards to OUTERMOST_LOOP. */
307 stmt_simple_memref_p (loop_p outermost_loop, gimple stmt, tree op)
315 dr = create_data_ref (outermost_loop, op, stmt, true);
316 fns = DR_ACCESS_FNS (dr);
318 for (i = 0; VEC_iterate (tree, fns, i, t); i++)
319 if (!graphite_can_represent_scev (t, outermost_loop->num))
329 /* Return true if the operand OP used in STMT is simple in regards to
333 is_simple_operand (loop_p outermost_loop, gimple stmt, tree op)
335 /* It is not a simple operand when it is a declaration, */
339 /* or a structure, */
340 if (AGGREGATE_TYPE_P (TREE_TYPE (op)))
343 /* or a memory access that cannot be analyzed by the data reference
345 if (handled_component_p (op) || INDIRECT_REF_P (op))
346 if (!stmt_simple_memref_p (outermost_loop, stmt, op))
349 return exclude_component_ref (op);
352 /* Return true only when STMT is simple enough for being handled by
353 Graphite. This depends on SCOP_ENTRY, as the parameters are
354 initialized relatively to this basic block, the linear functions
355 are initialized to OUTERMOST_LOOP and BB is the place where we try
356 to evaluate the STMT. */
359 stmt_simple_for_scop_p (basic_block scop_entry, loop_p outermost_loop,
360 gimple stmt, basic_block bb)
362 loop_p loop = bb->loop_father;
364 gcc_assert (scop_entry);
366 /* GIMPLE_ASM and GIMPLE_CALL may embed arbitrary side effects.
367 Calls have side-effects, except those to const or pure
369 if (gimple_has_volatile_ops (stmt)
370 || (gimple_code (stmt) == GIMPLE_CALL
371 && !(gimple_call_flags (stmt) & (ECF_CONST | ECF_PURE)))
372 || (gimple_code (stmt) == GIMPLE_ASM))
375 if (is_gimple_debug (stmt))
378 if (!stmt_has_simple_data_refs_p (outermost_loop, stmt))
381 switch (gimple_code (stmt))
391 enum tree_code code = gimple_cond_code (stmt);
393 /* We can handle all binary comparisons. Inequalities are
394 also supported as they can be represented with union of
396 if (!(code == LT_EXPR
404 FOR_EACH_SSA_TREE_OPERAND (op, stmt, op_iter, SSA_OP_ALL_USES)
405 if (!graphite_can_represent_expr (scop_entry, loop, outermost_loop,
407 /* We can not handle REAL_TYPE. Failed for pr39260. */
408 || TREE_CODE (TREE_TYPE (op)) == REAL_TYPE)
416 enum tree_code code = gimple_assign_rhs_code (stmt);
418 switch (get_gimple_rhs_class (code))
420 case GIMPLE_UNARY_RHS:
421 case GIMPLE_SINGLE_RHS:
422 return (is_simple_operand (outermost_loop, stmt,
423 gimple_assign_lhs (stmt))
424 && is_simple_operand (outermost_loop, stmt,
425 gimple_assign_rhs1 (stmt)));
427 case GIMPLE_BINARY_RHS:
428 return (is_simple_operand (outermost_loop, stmt,
429 gimple_assign_lhs (stmt))
430 && is_simple_operand (outermost_loop, stmt,
431 gimple_assign_rhs1 (stmt))
432 && is_simple_operand (outermost_loop, stmt,
433 gimple_assign_rhs2 (stmt)));
435 case GIMPLE_INVALID_RHS:
444 size_t n = gimple_call_num_args (stmt);
445 tree lhs = gimple_call_lhs (stmt);
447 if (lhs && !is_simple_operand (outermost_loop, stmt, lhs))
450 for (i = 0; i < n; i++)
451 if (!is_simple_operand (outermost_loop, stmt,
452 gimple_call_arg (stmt, i)))
459 /* These nodes cut a new scope. */
466 /* Returns the statement of BB that contains a harmful operation: that
467 can be a function call with side effects, the induction variables
468 are not linear with respect to SCOP_ENTRY, etc. The current open
469 scop should end before this statement. The evaluation is limited using
470 OUTERMOST_LOOP as outermost loop that may change. */
473 harmful_stmt_in_bb (basic_block scop_entry, loop_p outer_loop, basic_block bb)
475 gimple_stmt_iterator gsi;
477 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
478 if (!stmt_simple_for_scop_p (scop_entry, outer_loop, gsi_stmt (gsi), bb))
479 return gsi_stmt (gsi);
484 /* Return true when it is not possible to represent LOOP in the
485 polyhedral representation. This is evaluated taking SCOP_ENTRY and
486 OUTERMOST_LOOP in mind. */
489 graphite_can_represent_loop (basic_block scop_entry, loop_p outermost_loop,
492 tree niter = number_of_latch_executions (loop);
494 /* Number of iterations unknown. */
495 if (chrec_contains_undetermined (niter))
498 /* Number of iterations not affine. */
499 if (!graphite_can_represent_expr (scop_entry, loop, outermost_loop, niter))
505 /* Store information needed by scopdet_* functions. */
509 /* Exit of the open scop would stop if the current BB is harmful. */
512 /* Where the next scop would start if the current BB is harmful. */
515 /* The bb or one of its children contains open loop exits. That means
516 loop exit nodes that are not surrounded by a loop dominated by bb. */
519 /* The bb or one of its children contains only structures we can handle. */
523 static struct scopdet_info build_scops_1 (basic_block, loop_p,
524 VEC (sd_region, heap) **, loop_p);
526 /* Calculates BB infos. If bb is difficult we add valid SCoPs dominated by BB
527 to SCOPS. TYPE is the gbb_type of BB. */
529 static struct scopdet_info
530 scopdet_basic_block_info (basic_block bb, loop_p outermost_loop,
531 VEC (sd_region, heap) **scops, gbb_type type)
533 loop_p loop = bb->loop_father;
534 struct scopdet_info result;
537 /* XXX: ENTRY_BLOCK_PTR could be optimized in later steps. */
538 basic_block entry_block = ENTRY_BLOCK_PTR;
539 stmt = harmful_stmt_in_bb (entry_block, outermost_loop, bb);
540 result.difficult = (stmt != NULL);
547 result.exits = false;
549 /* Mark bbs terminating a SESE region difficult, if they start
551 if (!single_succ_p (bb))
552 result.difficult = true;
554 result.exit = single_succ (bb);
559 result.next = single_succ (bb);
560 result.exits = false;
561 result.exit = single_succ (bb);
564 case GBB_LOOP_SING_EXIT_HEADER:
566 VEC (sd_region, heap) *regions = VEC_alloc (sd_region, heap, 3);
567 struct scopdet_info sinfo;
568 edge exit_e = single_exit (loop);
570 sinfo = build_scops_1 (bb, outermost_loop, ®ions, loop);
572 if (!graphite_can_represent_loop (entry_block, outermost_loop, loop))
573 result.difficult = true;
575 result.difficult |= sinfo.difficult;
577 /* Try again with another loop level. */
579 && loop_depth (outermost_loop) + 1 == loop_depth (loop))
581 outermost_loop = loop;
583 VEC_free (sd_region, heap, regions);
584 regions = VEC_alloc (sd_region, heap, 3);
586 sinfo = scopdet_basic_block_info (bb, outermost_loop, scops, type);
589 result.difficult = true;
592 move_sd_regions (®ions, scops);
596 open_scop.entry = bb;
597 open_scop.exit = exit_e->dest;
598 VEC_safe_push (sd_region, heap, *scops, &open_scop);
599 VEC_free (sd_region, heap, regions);
604 result.exit = exit_e->dest;
605 result.next = exit_e->dest;
607 /* If we do not dominate result.next, remove it. It's either
608 the EXIT_BLOCK_PTR, or another bb dominates it and will
609 call the scop detection for this bb. */
610 if (!dominated_by_p (CDI_DOMINATORS, result.next, bb))
613 if (exit_e->src->loop_father != loop)
616 result.exits = false;
618 if (result.difficult)
619 move_sd_regions (®ions, scops);
621 VEC_free (sd_region, heap, regions);
627 case GBB_LOOP_MULT_EXIT_HEADER:
629 /* XXX: For now we just do not join loops with multiple exits. If the
630 exits lead to the same bb it may be possible to join the loop. */
631 VEC (sd_region, heap) *regions = VEC_alloc (sd_region, heap, 3);
632 VEC (edge, heap) *exits = get_loop_exit_edges (loop);
635 build_scops_1 (bb, loop, ®ions, loop);
637 /* Scan the code dominated by this loop. This means all bbs, that are
638 are dominated by a bb in this loop, but are not part of this loop.
641 - The loop exit destination is dominated by the exit sources.
643 TODO: We miss here the more complex cases:
644 - The exit destinations are dominated by another bb inside
646 - The loop dominates bbs, that are not exit destinations. */
647 for (i = 0; VEC_iterate (edge, exits, i, e); i++)
648 if (e->src->loop_father == loop
649 && dominated_by_p (CDI_DOMINATORS, e->dest, e->src))
651 if (loop_outer (outermost_loop))
652 outermost_loop = loop_outer (outermost_loop);
654 /* Pass loop_outer to recognize e->dest as loop header in
656 if (e->dest->loop_father->header == e->dest)
657 build_scops_1 (e->dest, outermost_loop, ®ions,
658 loop_outer (e->dest->loop_father));
660 build_scops_1 (e->dest, outermost_loop, ®ions,
661 e->dest->loop_father);
666 result.difficult = true;
667 result.exits = false;
668 move_sd_regions (®ions, scops);
669 VEC_free (edge, heap, exits);
672 case GBB_COND_HEADER:
674 VEC (sd_region, heap) *regions = VEC_alloc (sd_region, heap, 3);
675 struct scopdet_info sinfo;
676 VEC (basic_block, heap) *dominated;
679 basic_block last_exit = NULL;
681 result.exits = false;
683 /* First check the successors of BB, and check if it is
684 possible to join the different branches. */
685 for (i = 0; VEC_iterate (edge, bb->succs, i, e); i++)
687 /* Ignore loop exits. They will be handled after the loop
689 if (is_loop_exit (loop, e->dest))
695 /* Do not follow edges that lead to the end of the
696 conditions block. For example, in
706 the edge from 0 => 6. Only check if all paths lead to
709 if (!single_pred_p (e->dest))
711 /* Check, if edge leads directly to the end of this
716 if (e->dest != last_exit)
717 result.difficult = true;
722 if (!dominated_by_p (CDI_DOMINATORS, e->dest, bb))
724 result.difficult = true;
728 sinfo = build_scops_1 (e->dest, outermost_loop, ®ions, loop);
730 result.exits |= sinfo.exits;
731 result.difficult |= sinfo.difficult;
733 /* Checks, if all branches end at the same point.
734 If that is true, the condition stays joinable.
735 Have a look at the example above. */
739 last_exit = sinfo.exit;
741 if (sinfo.exit != last_exit)
742 result.difficult = true;
745 result.difficult = true;
749 result.difficult = true;
751 /* Join the branches of the condition if possible. */
752 if (!result.exits && !result.difficult)
754 /* Only return a next pointer if we dominate this pointer.
755 Otherwise it will be handled by the bb dominating it. */
756 if (dominated_by_p (CDI_DOMINATORS, last_exit, bb)
758 result.next = last_exit;
762 result.exit = last_exit;
764 VEC_free (sd_region, heap, regions);
768 /* Scan remaining bbs dominated by BB. */
769 dominated = get_dominated_by (CDI_DOMINATORS, bb);
771 for (i = 0; VEC_iterate (basic_block, dominated, i, dom_bb); i++)
773 /* Ignore loop exits: they will be handled after the loop body. */
774 if (loop_depth (find_common_loop (loop, dom_bb->loop_father))
781 /* Ignore the bbs processed above. */
782 if (single_pred_p (dom_bb) && single_pred (dom_bb) == bb)
785 if (loop_depth (loop) > loop_depth (dom_bb->loop_father))
786 sinfo = build_scops_1 (dom_bb, outermost_loop, ®ions,
789 sinfo = build_scops_1 (dom_bb, outermost_loop, ®ions, loop);
791 result.exits |= sinfo.exits;
792 result.difficult = true;
796 VEC_free (basic_block, heap, dominated);
799 move_sd_regions (®ions, scops);
811 /* Starting from CURRENT we walk the dominance tree and add new sd_regions to
812 SCOPS. The analyse if a sd_region can be handled is based on the value
813 of OUTERMOST_LOOP. Only loops inside OUTERMOST loops may change. LOOP
814 is the loop in which CURRENT is handled.
816 TODO: These functions got a little bit big. They definitely should be cleaned
819 static struct scopdet_info
820 build_scops_1 (basic_block current, loop_p outermost_loop,
821 VEC (sd_region, heap) **scops, loop_p loop)
823 bool in_scop = false;
825 struct scopdet_info sinfo;
827 /* Initialize result. */
828 struct scopdet_info result;
829 result.exits = false;
830 result.difficult = false;
833 open_scop.entry = NULL;
834 open_scop.exit = NULL;
837 /* Loop over the dominance tree. If we meet a difficult bb, close
838 the current SCoP. Loop and condition header start a new layer,
839 and can only be added if all bbs in deeper layers are simple. */
840 while (current != NULL)
842 sinfo = scopdet_basic_block_info (current, outermost_loop, scops,
843 get_bb_type (current, loop));
845 if (!in_scop && !(sinfo.exits || sinfo.difficult))
847 open_scop.entry = current;
848 open_scop.exit = NULL;
851 else if (in_scop && (sinfo.exits || sinfo.difficult))
853 open_scop.exit = current;
854 VEC_safe_push (sd_region, heap, *scops, &open_scop);
858 result.difficult |= sinfo.difficult;
859 result.exits |= sinfo.exits;
861 current = sinfo.next;
864 /* Try to close open_scop, if we are still in an open SCoP. */
867 open_scop.exit = sinfo.exit;
868 gcc_assert (open_scop.exit);
869 VEC_safe_push (sd_region, heap, *scops, &open_scop);
872 result.exit = sinfo.exit;
876 /* Checks if a bb is contained in REGION. */
879 bb_in_sd_region (basic_block bb, sd_region *region)
881 return bb_in_region (bb, region->entry, region->exit);
884 /* Returns the single entry edge of REGION, if it does not exits NULL. */
887 find_single_entry_edge (sd_region *region)
893 FOR_EACH_EDGE (e, ei, region->entry->preds)
894 if (!bb_in_sd_region (e->src, region))
909 /* Returns the single exit edge of REGION, if it does not exits NULL. */
912 find_single_exit_edge (sd_region *region)
918 FOR_EACH_EDGE (e, ei, region->exit->preds)
919 if (bb_in_sd_region (e->src, region))
934 /* Create a single entry edge for REGION. */
937 create_single_entry_edge (sd_region *region)
939 if (find_single_entry_edge (region))
942 /* There are multiple predecessors for bb_3
955 There are two edges (1->3, 2->3), that point from outside into the region,
956 and another one (5->3), a loop latch, lead to bb_3.
964 | |\ (3.0 -> 3.1) = single entry edge
973 If the loop is part of the SCoP, we have to redirect the loop latches.
979 | | (3.0 -> 3.1) = entry edge
988 if (region->entry->loop_father->header != region->entry
989 || dominated_by_p (CDI_DOMINATORS,
990 loop_latch_edge (region->entry->loop_father)->src,
993 edge forwarder = split_block_after_labels (region->entry);
994 region->entry = forwarder->dest;
997 /* This case is never executed, as the loop headers seem always to have a
998 single edge pointing from outside into the loop. */
1001 #ifdef ENABLE_CHECKING
1002 gcc_assert (find_single_entry_edge (region));
1006 /* Check if the sd_region, mentioned in EDGE, has no exit bb. */
1009 sd_region_without_exit (edge e)
1011 sd_region *r = (sd_region *) e->aux;
1014 return r->exit == NULL;
1019 /* Create a single exit edge for REGION. */
1022 create_single_exit_edge (sd_region *region)
1026 edge forwarder = NULL;
1029 if (find_single_exit_edge (region))
1032 /* We create a forwarder bb (5) for all edges leaving this region
1033 (3->5, 4->5). All other edges leading to the same bb, are moved
1034 to a new bb (6). If these edges where part of another region (2->5)
1035 we update the region->exit pointer, of this region.
1037 To identify which edge belongs to which region we depend on the e->aux
1038 pointer in every edge. It points to the region of the edge or to NULL,
1039 if the edge is not part of any region.
1041 1 2 3 4 1->5 no region, 2->5 region->exit = 5,
1042 \| |/ 3->5 region->exit = NULL, 4->5 region->exit = NULL
1047 1 2 3 4 1->6 no region, 2->6 region->exit = 6,
1048 | | \/ 3->5 no region, 4->5 no region,
1050 \| / 5->6 region->exit = 6
1053 Now there is only a single exit edge (5->6). */
1054 exit = region->exit;
1055 region->exit = NULL;
1056 forwarder = make_forwarder_block (exit, &sd_region_without_exit, NULL);
1058 /* Unmark the edges, that are no longer exit edges. */
1059 FOR_EACH_EDGE (e, ei, forwarder->src->preds)
1063 /* Mark the new exit edge. */
1064 single_succ_edge (forwarder->src)->aux = region;
1066 /* Update the exit bb of all regions, where exit edges lead to
1068 FOR_EACH_EDGE (e, ei, forwarder->dest->preds)
1070 ((sd_region *) e->aux)->exit = forwarder->dest;
1072 #ifdef ENABLE_CHECKING
1073 gcc_assert (find_single_exit_edge (region));
1077 /* Unmark the exit edges of all REGIONS.
1078 See comment in "create_single_exit_edge". */
1081 unmark_exit_edges (VEC (sd_region, heap) *regions)
1088 for (i = 0; VEC_iterate (sd_region, regions, i, s); i++)
1089 FOR_EACH_EDGE (e, ei, s->exit->preds)
1094 /* Mark the exit edges of all REGIONS.
1095 See comment in "create_single_exit_edge". */
1098 mark_exit_edges (VEC (sd_region, heap) *regions)
1105 for (i = 0; VEC_iterate (sd_region, regions, i, s); i++)
1106 FOR_EACH_EDGE (e, ei, s->exit->preds)
1107 if (bb_in_sd_region (e->src, s))
1111 /* Create for all scop regions a single entry and a single exit edge. */
1114 create_sese_edges (VEC (sd_region, heap) *regions)
1119 for (i = 0; VEC_iterate (sd_region, regions, i, s); i++)
1120 create_single_entry_edge (s);
1122 mark_exit_edges (regions);
1124 for (i = 0; VEC_iterate (sd_region, regions, i, s); i++)
1125 create_single_exit_edge (s);
1127 unmark_exit_edges (regions);
1129 fix_loop_structure (NULL);
1131 #ifdef ENABLE_CHECKING
1132 verify_loop_structure ();
1133 verify_dominators (CDI_DOMINATORS);
1138 /* Create graphite SCoPs from an array of scop detection REGIONS. */
1141 build_graphite_scops (VEC (sd_region, heap) *regions,
1142 VEC (scop_p, heap) **scops)
1147 for (i = 0; VEC_iterate (sd_region, regions, i, s); i++)
1149 edge entry = find_single_entry_edge (s);
1150 edge exit = find_single_exit_edge (s);
1151 scop_p scop = new_scop (new_sese (entry, exit));
1152 VEC_safe_push (scop_p, heap, *scops, scop);
1154 /* Are there overlapping SCoPs? */
1155 #ifdef ENABLE_CHECKING
1160 for (j = 0; VEC_iterate (sd_region, regions, j, s2); j++)
1162 gcc_assert (!bb_in_sd_region (s->entry, s2));
1168 /* Returns true when BB contains only close phi nodes. */
1171 contains_only_close_phi_nodes (basic_block bb)
1173 gimple_stmt_iterator gsi;
1175 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1176 if (gimple_code (gsi_stmt (gsi)) != GIMPLE_LABEL)
1182 /* Print statistics for SCOP to FILE. */
1185 print_graphite_scop_statistics (FILE* file, scop_p scop)
1190 long n_conditions = 0;
1194 long n_p_conditions = 0;
1200 gimple_stmt_iterator psi;
1201 loop_p loop = bb->loop_father;
1203 if (!bb_in_sese_p (bb, SCOP_REGION (scop)))
1207 n_p_bbs += bb->count;
1209 if (VEC_length (edge, bb->succs) > 1)
1212 n_p_conditions += bb->count;
1215 for (psi = gsi_start_bb (bb); !gsi_end_p (psi); gsi_next (&psi))
1218 n_p_stmts += bb->count;
1221 if (loop->header == bb && loop_in_sese_p (loop, SCOP_REGION (scop)))
1224 n_p_loops += bb->count;
1229 fprintf (file, "\nBefore limit_scops SCoP statistics (");
1230 fprintf (file, "BBS:%ld, ", n_bbs);
1231 fprintf (file, "LOOPS:%ld, ", n_loops);
1232 fprintf (file, "CONDITIONS:%ld, ", n_conditions);
1233 fprintf (file, "STMTS:%ld)\n", n_stmts);
1234 fprintf (file, "\nBefore limit_scops SCoP profiling statistics (");
1235 fprintf (file, "BBS:%ld, ", n_p_bbs);
1236 fprintf (file, "LOOPS:%ld, ", n_p_loops);
1237 fprintf (file, "CONDITIONS:%ld, ", n_p_conditions);
1238 fprintf (file, "STMTS:%ld)\n", n_p_stmts);
1241 /* Print statistics for SCOPS to FILE. */
1244 print_graphite_statistics (FILE* file, VEC (scop_p, heap) *scops)
1249 for (i = 0; VEC_iterate (scop_p, scops, i, scop); i++)
1250 print_graphite_scop_statistics (file, scop);
1253 /* Version of free_scops special cased for limit_scops. */
1256 free_scops_1 (VEC (scop_p, heap) **scops)
1261 for (i = 0; VEC_iterate (scop_p, *scops, i, scop); i++)
1263 sese region = SCOP_REGION (scop);
1264 free (SESE_PARAMS_NAMES (region));
1265 SESE_PARAMS_NAMES (region) = 0;
1268 free_scops (*scops);
1271 /* We limit all SCoPs to SCoPs, that are completely surrounded by a loop.
1281 * SCoP frontier, as this line is not surrounded by any loop. *
1285 This is necessary as scalar evolution and parameter detection need a
1286 outermost loop to initialize parameters correctly.
1288 TODO: FIX scalar evolution and parameter detection to allow more flexible
1292 limit_scops (VEC (scop_p, heap) **scops)
1294 VEC (sd_region, heap) *regions = VEC_alloc (sd_region, heap, 3);
1299 for (i = 0; VEC_iterate (scop_p, *scops, i, scop); i++)
1303 sese region = SCOP_REGION (scop);
1304 build_scop_bbs (scop);
1305 build_sese_loop_nests (region);
1307 for (j = 0; VEC_iterate (loop_p, SESE_LOOP_NEST (region), j, loop); j++)
1308 if (!loop_in_sese_p (loop_outer (loop), region)
1309 && single_exit (loop))
1311 sd_region open_scop;
1312 open_scop.entry = loop->header;
1313 open_scop.exit = single_exit (loop)->dest;
1315 /* This is a hack on top of the limit_scops hack. The
1316 limit_scops hack should disappear all together. */
1317 if (single_succ_p (open_scop.exit)
1318 && contains_only_close_phi_nodes (open_scop.exit))
1319 open_scop.exit = single_succ_edge (open_scop.exit)->dest;
1321 VEC_safe_push (sd_region, heap, regions, &open_scop);
1325 free_scops_1 (scops);
1326 *scops = VEC_alloc (scop_p, heap, 3);
1328 create_sese_edges (regions);
1329 build_graphite_scops (regions, scops);
1330 VEC_free (sd_region, heap, regions);
1333 /* Transforms LOOP to the canonical loop closed SSA form. */
1336 canonicalize_loop_closed_ssa (loop_p loop)
1338 edge e = single_exit (loop);
1341 if (!e || e->flags & EDGE_ABNORMAL)
1346 if (VEC_length (edge, bb->preds) == 1)
1347 split_block_after_labels (bb);
1350 gimple_stmt_iterator psi;
1351 basic_block close = split_edge (e);
1353 e = single_succ_edge (close);
1355 for (psi = gsi_start_phis (bb); !gsi_end_p (psi); gsi_next (&psi))
1357 gimple phi = gsi_stmt (psi);
1360 for (i = 0; i < gimple_phi_num_args (phi); i++)
1361 if (gimple_phi_arg_edge (phi, i) == e)
1363 tree res, arg = gimple_phi_arg_def (phi, i);
1364 use_operand_p use_p;
1367 if (TREE_CODE (arg) != SSA_NAME)
1370 close_phi = create_phi_node (arg, close);
1371 res = create_new_def_for (gimple_phi_result (close_phi),
1373 gimple_phi_result_ptr (close_phi));
1374 add_phi_arg (close_phi, arg,
1375 gimple_phi_arg_edge (close_phi, 0),
1377 use_p = gimple_phi_arg_imm_use_ptr (phi, i);
1378 replace_exp (use_p, res);
1385 /* Converts the current loop closed SSA form to a canonical form
1386 expected by the Graphite code generation.
1388 The loop closed SSA form has the following invariant: a variable
1389 defined in a loop that is used outside the loop appears only in the
1390 phi nodes in the destination of the loop exit. These phi nodes are
1391 called close phi nodes.
1393 The canonical loop closed SSA form contains the extra invariants:
1395 - when the loop contains only one exit, the close phi nodes contain
1396 only one argument. That implies that the basic block that contains
1397 the close phi nodes has only one predecessor, that is a basic block
1400 - the basic block containing the close phi nodes does not contain
1405 canonicalize_loop_closed_ssa_form (void)
1410 #ifdef ENABLE_CHECKING
1411 verify_loop_closed_ssa ();
1414 FOR_EACH_LOOP (li, loop, 0)
1415 canonicalize_loop_closed_ssa (loop);
1417 rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
1418 update_ssa (TODO_update_ssa);
1420 #ifdef ENABLE_CHECKING
1421 verify_loop_closed_ssa ();
1425 /* Find Static Control Parts (SCoP) in the current function and pushes
1429 build_scops (VEC (scop_p, heap) **scops)
1431 struct loop *loop = current_loops->tree_root;
1432 VEC (sd_region, heap) *regions = VEC_alloc (sd_region, heap, 3);
1434 canonicalize_loop_closed_ssa_form ();
1435 build_scops_1 (single_succ (ENTRY_BLOCK_PTR), ENTRY_BLOCK_PTR->loop_father,
1437 create_sese_edges (regions);
1438 build_graphite_scops (regions, scops);
1440 if (dump_file && (dump_flags & TDF_DETAILS))
1441 print_graphite_statistics (dump_file, *scops);
1443 limit_scops (scops);
1444 VEC_free (sd_region, heap, regions);
1446 if (dump_file && (dump_flags & TDF_DETAILS))
1447 fprintf (dump_file, "\nnumber of SCoPs: %d\n",
1448 VEC_length (scop_p, *scops));
1451 /* Pretty print to FILE all the SCoPs in DOT format and mark them with
1452 different colors. If there are not enough colors, paint the
1453 remaining SCoPs in gray.
1456 - "*" after the node number denotes the entry of a SCoP,
1457 - "#" after the node number denotes the exit of a SCoP,
1458 - "()" around the node number denotes the entry or the
1459 exit nodes of the SCOP. These are not part of SCoP. */
1462 dot_all_scops_1 (FILE *file, VEC (scop_p, heap) *scops)
1471 /* Disable debugging while printing graph. */
1472 int tmp_dump_flags = dump_flags;
1475 fprintf (file, "digraph all {\n");
1479 int part_of_scop = false;
1481 /* Use HTML for every bb label. So we are able to print bbs
1482 which are part of two different SCoPs, with two different
1483 background colors. */
1484 fprintf (file, "%d [label=<\n <TABLE BORDER=\"0\" CELLBORDER=\"1\" ",
1486 fprintf (file, "CELLSPACING=\"0\">\n");
1488 /* Select color for SCoP. */
1489 for (i = 0; VEC_iterate (scop_p, scops, i, scop); i++)
1491 sese region = SCOP_REGION (scop);
1492 if (bb_in_sese_p (bb, region)
1493 || (SESE_EXIT_BB (region) == bb)
1494 || (SESE_ENTRY_BB (region) == bb))
1507 case 3: /* purple */
1510 case 4: /* orange */
1513 case 5: /* yellow */
1553 fprintf (file, " <TR><TD WIDTH=\"50\" BGCOLOR=\"%s\">", color);
1555 if (!bb_in_sese_p (bb, region))
1556 fprintf (file, " (");
1558 if (bb == SESE_ENTRY_BB (region)
1559 && bb == SESE_EXIT_BB (region))
1560 fprintf (file, " %d*# ", bb->index);
1561 else if (bb == SESE_ENTRY_BB (region))
1562 fprintf (file, " %d* ", bb->index);
1563 else if (bb == SESE_EXIT_BB (region))
1564 fprintf (file, " %d# ", bb->index);
1566 fprintf (file, " %d ", bb->index);
1568 if (!bb_in_sese_p (bb,region))
1569 fprintf (file, ")");
1571 fprintf (file, "</TD></TR>\n");
1572 part_of_scop = true;
1578 fprintf (file, " <TR><TD WIDTH=\"50\" BGCOLOR=\"#ffffff\">");
1579 fprintf (file, " %d </TD></TR>\n", bb->index);
1581 fprintf (file, " </TABLE>>, shape=box, style=\"setlinewidth(0)\"]\n");
1586 FOR_EACH_EDGE (e, ei, bb->succs)
1587 fprintf (file, "%d -> %d;\n", bb->index, e->dest->index);
1590 fputs ("}\n\n", file);
1592 /* Enable debugging again. */
1593 dump_flags = tmp_dump_flags;
1596 /* Display all SCoPs using dotty. */
1599 dot_all_scops (VEC (scop_p, heap) *scops)
1601 /* When debugging, enable the following code. This cannot be used
1602 in production compilers because it calls "system". */
1605 FILE *stream = fopen ("/tmp/allscops.dot", "w");
1606 gcc_assert (stream);
1608 dot_all_scops_1 (stream, scops);
1611 x = system ("dotty /tmp/allscops.dot");
1613 dot_all_scops_1 (stderr, scops);
1617 /* Display all SCoPs using dotty. */
1620 dot_scop (scop_p scop)
1622 VEC (scop_p, heap) *scops = NULL;
1625 VEC_safe_push (scop_p, heap, scops, scop);
1627 /* When debugging, enable the following code. This cannot be used
1628 in production compilers because it calls "system". */
1632 FILE *stream = fopen ("/tmp/allscops.dot", "w");
1633 gcc_assert (stream);
1635 dot_all_scops_1 (stream, scops);
1637 x = system ("dotty /tmp/allscops.dot");
1640 dot_all_scops_1 (stderr, scops);
1643 VEC_free (scop_p, heap, scops);