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 true if the data references of STMT can be represented by
256 stmt_has_simple_data_refs_p (loop_p outermost_loop, gimple stmt)
262 int loop = outermost_loop->num;
263 VEC (data_reference_p, heap) *drs = VEC_alloc (data_reference_p, heap, 5);
265 graphite_find_data_references_in_stmt (outermost_loop, stmt, &drs);
267 for (j = 0; VEC_iterate (data_reference_p, drs, j, dr); j++)
268 for (i = 0; i < DR_NUM_DIMENSIONS (dr); i++)
269 if (!graphite_can_represent_scev (DR_ACCESS_FN (dr, i), loop))
276 free_data_refs (drs);
280 /* Return false if the TREE_CODE of the operand OP or any of its operands
281 is a COMPONENT_REF. */
284 exclude_component_ref (tree op)
292 if (TREE_CODE (op) == COMPONENT_REF)
295 len = TREE_OPERAND_LENGTH (op);
296 for (i = 0; i < len; ++i)
297 if (!exclude_component_ref (TREE_OPERAND (op, i)))
303 /* Return true if the operand OP used in STMT is simple in regards to
307 is_simple_operand (tree op)
309 /* It is not a simple operand when it is a declaration or a
311 return !DECL_P (op) && !AGGREGATE_TYPE_P (TREE_TYPE (op))
312 && exclude_component_ref (op);
315 /* Return true only when STMT is simple enough for being handled by
316 Graphite. This depends on SCOP_ENTRY, as the parameters are
317 initialized relatively to this basic block, the linear functions
318 are initialized to OUTERMOST_LOOP and BB is the place where we try
319 to evaluate the STMT. */
322 stmt_simple_for_scop_p (basic_block scop_entry, loop_p outermost_loop,
323 gimple stmt, basic_block bb)
325 loop_p loop = bb->loop_father;
327 gcc_assert (scop_entry);
329 /* GIMPLE_ASM and GIMPLE_CALL may embed arbitrary side effects.
330 Calls have side-effects, except those to const or pure
332 if (gimple_has_volatile_ops (stmt)
333 || (gimple_code (stmt) == GIMPLE_CALL
334 && !(gimple_call_flags (stmt) & (ECF_CONST | ECF_PURE)))
335 || (gimple_code (stmt) == GIMPLE_ASM))
338 if (is_gimple_debug (stmt))
341 if (!stmt_has_simple_data_refs_p (outermost_loop, stmt))
344 switch (gimple_code (stmt))
354 enum tree_code code = gimple_cond_code (stmt);
356 /* We can handle all binary comparisons. Inequalities are
357 also supported as they can be represented with union of
359 if (!(code == LT_EXPR
367 FOR_EACH_SSA_TREE_OPERAND (op, stmt, op_iter, SSA_OP_ALL_USES)
368 if (!graphite_can_represent_expr (scop_entry, loop, outermost_loop,
370 /* We can not handle REAL_TYPE. Failed for pr39260. */
371 || TREE_CODE (TREE_TYPE (op)) == REAL_TYPE)
379 enum tree_code code = gimple_assign_rhs_code (stmt);
381 switch (get_gimple_rhs_class (code))
383 case GIMPLE_UNARY_RHS:
384 case GIMPLE_SINGLE_RHS:
385 return (is_simple_operand (gimple_assign_lhs (stmt))
386 && is_simple_operand (gimple_assign_rhs1 (stmt)));
388 case GIMPLE_BINARY_RHS:
389 return (is_simple_operand (gimple_assign_lhs (stmt))
390 && is_simple_operand (gimple_assign_rhs1 (stmt))
391 && is_simple_operand (gimple_assign_rhs2 (stmt)));
393 case GIMPLE_INVALID_RHS:
402 size_t n = gimple_call_num_args (stmt);
403 tree lhs = gimple_call_lhs (stmt);
405 if (lhs && !is_simple_operand (lhs))
408 for (i = 0; i < n; i++)
409 if (!is_simple_operand (gimple_call_arg (stmt, i)))
416 /* These nodes cut a new scope. */
423 /* Returns the statement of BB that contains a harmful operation: that
424 can be a function call with side effects, the induction variables
425 are not linear with respect to SCOP_ENTRY, etc. The current open
426 scop should end before this statement. The evaluation is limited using
427 OUTERMOST_LOOP as outermost loop that may change. */
430 harmful_stmt_in_bb (basic_block scop_entry, loop_p outer_loop, basic_block bb)
432 gimple_stmt_iterator gsi;
434 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
435 if (!stmt_simple_for_scop_p (scop_entry, outer_loop, gsi_stmt (gsi), bb))
436 return gsi_stmt (gsi);
441 /* Return true when it is not possible to represent LOOP in the
442 polyhedral representation. This is evaluated taking SCOP_ENTRY and
443 OUTERMOST_LOOP in mind. */
446 graphite_can_represent_loop (basic_block scop_entry, loop_p outermost_loop,
449 tree niter = number_of_latch_executions (loop);
451 /* Number of iterations unknown. */
452 if (chrec_contains_undetermined (niter))
455 /* Number of iterations not affine. */
456 if (!graphite_can_represent_expr (scop_entry, loop, outermost_loop, niter))
462 /* Store information needed by scopdet_* functions. */
466 /* Exit of the open scop would stop if the current BB is harmful. */
469 /* Where the next scop would start if the current BB is harmful. */
472 /* The bb or one of its children contains open loop exits. That means
473 loop exit nodes that are not surrounded by a loop dominated by bb. */
476 /* The bb or one of its children contains only structures we can handle. */
480 static struct scopdet_info build_scops_1 (basic_block, loop_p,
481 VEC (sd_region, heap) **, loop_p);
483 /* Calculates BB infos. If bb is difficult we add valid SCoPs dominated by BB
484 to SCOPS. TYPE is the gbb_type of BB. */
486 static struct scopdet_info
487 scopdet_basic_block_info (basic_block bb, loop_p outermost_loop,
488 VEC (sd_region, heap) **scops, gbb_type type)
490 loop_p loop = bb->loop_father;
491 struct scopdet_info result;
494 /* XXX: ENTRY_BLOCK_PTR could be optimized in later steps. */
495 basic_block entry_block = ENTRY_BLOCK_PTR;
496 stmt = harmful_stmt_in_bb (entry_block, outermost_loop, bb);
497 result.difficult = (stmt != NULL);
504 result.exits = false;
506 /* Mark bbs terminating a SESE region difficult, if they start
508 if (!single_succ_p (bb))
509 result.difficult = true;
511 result.exit = single_succ (bb);
516 result.next = single_succ (bb);
517 result.exits = false;
518 result.exit = single_succ (bb);
521 case GBB_LOOP_SING_EXIT_HEADER:
523 VEC (sd_region, heap) *regions = VEC_alloc (sd_region, heap, 3);
524 struct scopdet_info sinfo;
525 edge exit_e = single_exit (loop);
527 sinfo = build_scops_1 (bb, outermost_loop, ®ions, loop);
529 if (!graphite_can_represent_loop (entry_block, outermost_loop, loop))
530 result.difficult = true;
532 result.difficult |= sinfo.difficult;
534 /* Try again with another loop level. */
536 && loop_depth (outermost_loop) + 1 == loop_depth (loop))
538 outermost_loop = loop;
540 VEC_free (sd_region, heap, regions);
541 regions = VEC_alloc (sd_region, heap, 3);
543 sinfo = scopdet_basic_block_info (bb, outermost_loop, scops, type);
546 result.difficult = true;
549 move_sd_regions (®ions, scops);
553 open_scop.entry = bb;
554 open_scop.exit = exit_e->dest;
555 VEC_safe_push (sd_region, heap, *scops, &open_scop);
556 VEC_free (sd_region, heap, regions);
561 result.exit = exit_e->dest;
562 result.next = exit_e->dest;
564 /* If we do not dominate result.next, remove it. It's either
565 the EXIT_BLOCK_PTR, or another bb dominates it and will
566 call the scop detection for this bb. */
567 if (!dominated_by_p (CDI_DOMINATORS, result.next, bb))
570 if (exit_e->src->loop_father != loop)
573 result.exits = false;
575 if (result.difficult)
576 move_sd_regions (®ions, scops);
578 VEC_free (sd_region, heap, regions);
584 case GBB_LOOP_MULT_EXIT_HEADER:
586 /* XXX: For now we just do not join loops with multiple exits. If the
587 exits lead to the same bb it may be possible to join the loop. */
588 VEC (sd_region, heap) *regions = VEC_alloc (sd_region, heap, 3);
589 VEC (edge, heap) *exits = get_loop_exit_edges (loop);
592 build_scops_1 (bb, loop, ®ions, loop);
594 /* Scan the code dominated by this loop. This means all bbs, that are
595 are dominated by a bb in this loop, but are not part of this loop.
598 - The loop exit destination is dominated by the exit sources.
600 TODO: We miss here the more complex cases:
601 - The exit destinations are dominated by another bb inside
603 - The loop dominates bbs, that are not exit destinations. */
604 for (i = 0; VEC_iterate (edge, exits, i, e); i++)
605 if (e->src->loop_father == loop
606 && dominated_by_p (CDI_DOMINATORS, e->dest, e->src))
608 if (loop_outer (outermost_loop))
609 outermost_loop = loop_outer (outermost_loop);
611 /* Pass loop_outer to recognize e->dest as loop header in
613 if (e->dest->loop_father->header == e->dest)
614 build_scops_1 (e->dest, outermost_loop, ®ions,
615 loop_outer (e->dest->loop_father));
617 build_scops_1 (e->dest, outermost_loop, ®ions,
618 e->dest->loop_father);
623 result.difficult = true;
624 result.exits = false;
625 move_sd_regions (®ions, scops);
626 VEC_free (edge, heap, exits);
629 case GBB_COND_HEADER:
631 VEC (sd_region, heap) *regions = VEC_alloc (sd_region, heap, 3);
632 struct scopdet_info sinfo;
633 VEC (basic_block, heap) *dominated;
636 basic_block last_exit = NULL;
638 result.exits = false;
640 /* First check the successors of BB, and check if it is
641 possible to join the different branches. */
642 for (i = 0; VEC_iterate (edge, bb->succs, i, e); i++)
644 /* Ignore loop exits. They will be handled after the loop
646 if (is_loop_exit (loop, e->dest))
652 /* Do not follow edges that lead to the end of the
653 conditions block. For example, in
663 the edge from 0 => 6. Only check if all paths lead to
666 if (!single_pred_p (e->dest))
668 /* Check, if edge leads directly to the end of this
673 if (e->dest != last_exit)
674 result.difficult = true;
679 if (!dominated_by_p (CDI_DOMINATORS, e->dest, bb))
681 result.difficult = true;
685 sinfo = build_scops_1 (e->dest, outermost_loop, ®ions, loop);
687 result.exits |= sinfo.exits;
688 result.difficult |= sinfo.difficult;
690 /* Checks, if all branches end at the same point.
691 If that is true, the condition stays joinable.
692 Have a look at the example above. */
696 last_exit = sinfo.exit;
698 if (sinfo.exit != last_exit)
699 result.difficult = true;
702 result.difficult = true;
706 result.difficult = true;
708 /* Join the branches of the condition if possible. */
709 if (!result.exits && !result.difficult)
711 /* Only return a next pointer if we dominate this pointer.
712 Otherwise it will be handled by the bb dominating it. */
713 if (dominated_by_p (CDI_DOMINATORS, last_exit, bb)
715 result.next = last_exit;
719 result.exit = last_exit;
721 VEC_free (sd_region, heap, regions);
725 /* Scan remaining bbs dominated by BB. */
726 dominated = get_dominated_by (CDI_DOMINATORS, bb);
728 for (i = 0; VEC_iterate (basic_block, dominated, i, dom_bb); i++)
730 /* Ignore loop exits: they will be handled after the loop body. */
731 if (loop_depth (find_common_loop (loop, dom_bb->loop_father))
738 /* Ignore the bbs processed above. */
739 if (single_pred_p (dom_bb) && single_pred (dom_bb) == bb)
742 if (loop_depth (loop) > loop_depth (dom_bb->loop_father))
743 sinfo = build_scops_1 (dom_bb, outermost_loop, ®ions,
746 sinfo = build_scops_1 (dom_bb, outermost_loop, ®ions, loop);
748 result.exits |= sinfo.exits;
749 result.difficult = true;
753 VEC_free (basic_block, heap, dominated);
756 move_sd_regions (®ions, scops);
768 /* Starting from CURRENT we walk the dominance tree and add new sd_regions to
769 SCOPS. The analyse if a sd_region can be handled is based on the value
770 of OUTERMOST_LOOP. Only loops inside OUTERMOST loops may change. LOOP
771 is the loop in which CURRENT is handled.
773 TODO: These functions got a little bit big. They definitely should be cleaned
776 static struct scopdet_info
777 build_scops_1 (basic_block current, loop_p outermost_loop,
778 VEC (sd_region, heap) **scops, loop_p loop)
780 bool in_scop = false;
782 struct scopdet_info sinfo;
784 /* Initialize result. */
785 struct scopdet_info result;
786 result.exits = false;
787 result.difficult = false;
790 open_scop.entry = NULL;
791 open_scop.exit = NULL;
794 /* Loop over the dominance tree. If we meet a difficult bb, close
795 the current SCoP. Loop and condition header start a new layer,
796 and can only be added if all bbs in deeper layers are simple. */
797 while (current != NULL)
799 sinfo = scopdet_basic_block_info (current, outermost_loop, scops,
800 get_bb_type (current, loop));
802 if (!in_scop && !(sinfo.exits || sinfo.difficult))
804 open_scop.entry = current;
805 open_scop.exit = NULL;
808 else if (in_scop && (sinfo.exits || sinfo.difficult))
810 open_scop.exit = current;
811 VEC_safe_push (sd_region, heap, *scops, &open_scop);
815 result.difficult |= sinfo.difficult;
816 result.exits |= sinfo.exits;
818 current = sinfo.next;
821 /* Try to close open_scop, if we are still in an open SCoP. */
824 open_scop.exit = sinfo.exit;
825 gcc_assert (open_scop.exit);
826 VEC_safe_push (sd_region, heap, *scops, &open_scop);
829 result.exit = sinfo.exit;
833 /* Checks if a bb is contained in REGION. */
836 bb_in_sd_region (basic_block bb, sd_region *region)
838 return bb_in_region (bb, region->entry, region->exit);
841 /* Returns the single entry edge of REGION, if it does not exits NULL. */
844 find_single_entry_edge (sd_region *region)
850 FOR_EACH_EDGE (e, ei, region->entry->preds)
851 if (!bb_in_sd_region (e->src, region))
866 /* Returns the single exit edge of REGION, if it does not exits NULL. */
869 find_single_exit_edge (sd_region *region)
875 FOR_EACH_EDGE (e, ei, region->exit->preds)
876 if (bb_in_sd_region (e->src, region))
891 /* Create a single entry edge for REGION. */
894 create_single_entry_edge (sd_region *region)
896 if (find_single_entry_edge (region))
899 /* There are multiple predecessors for bb_3
912 There are two edges (1->3, 2->3), that point from outside into the region,
913 and another one (5->3), a loop latch, lead to bb_3.
921 | |\ (3.0 -> 3.1) = single entry edge
930 If the loop is part of the SCoP, we have to redirect the loop latches.
936 | | (3.0 -> 3.1) = entry edge
945 if (region->entry->loop_father->header != region->entry
946 || dominated_by_p (CDI_DOMINATORS,
947 loop_latch_edge (region->entry->loop_father)->src,
950 edge forwarder = split_block_after_labels (region->entry);
951 region->entry = forwarder->dest;
954 /* This case is never executed, as the loop headers seem always to have a
955 single edge pointing from outside into the loop. */
958 #ifdef ENABLE_CHECKING
959 gcc_assert (find_single_entry_edge (region));
963 /* Check if the sd_region, mentioned in EDGE, has no exit bb. */
966 sd_region_without_exit (edge e)
968 sd_region *r = (sd_region *) e->aux;
971 return r->exit == NULL;
976 /* Create a single exit edge for REGION. */
979 create_single_exit_edge (sd_region *region)
983 edge forwarder = NULL;
986 if (find_single_exit_edge (region))
989 /* We create a forwarder bb (5) for all edges leaving this region
990 (3->5, 4->5). All other edges leading to the same bb, are moved
991 to a new bb (6). If these edges where part of another region (2->5)
992 we update the region->exit pointer, of this region.
994 To identify which edge belongs to which region we depend on the e->aux
995 pointer in every edge. It points to the region of the edge or to NULL,
996 if the edge is not part of any region.
998 1 2 3 4 1->5 no region, 2->5 region->exit = 5,
999 \| |/ 3->5 region->exit = NULL, 4->5 region->exit = NULL
1004 1 2 3 4 1->6 no region, 2->6 region->exit = 6,
1005 | | \/ 3->5 no region, 4->5 no region,
1007 \| / 5->6 region->exit = 6
1010 Now there is only a single exit edge (5->6). */
1011 exit = region->exit;
1012 region->exit = NULL;
1013 forwarder = make_forwarder_block (exit, &sd_region_without_exit, NULL);
1015 /* Unmark the edges, that are no longer exit edges. */
1016 FOR_EACH_EDGE (e, ei, forwarder->src->preds)
1020 /* Mark the new exit edge. */
1021 single_succ_edge (forwarder->src)->aux = region;
1023 /* Update the exit bb of all regions, where exit edges lead to
1025 FOR_EACH_EDGE (e, ei, forwarder->dest->preds)
1027 ((sd_region *) e->aux)->exit = forwarder->dest;
1029 #ifdef ENABLE_CHECKING
1030 gcc_assert (find_single_exit_edge (region));
1034 /* Unmark the exit edges of all REGIONS.
1035 See comment in "create_single_exit_edge". */
1038 unmark_exit_edges (VEC (sd_region, heap) *regions)
1045 for (i = 0; VEC_iterate (sd_region, regions, i, s); i++)
1046 FOR_EACH_EDGE (e, ei, s->exit->preds)
1051 /* Mark the exit edges of all REGIONS.
1052 See comment in "create_single_exit_edge". */
1055 mark_exit_edges (VEC (sd_region, heap) *regions)
1062 for (i = 0; VEC_iterate (sd_region, regions, i, s); i++)
1063 FOR_EACH_EDGE (e, ei, s->exit->preds)
1064 if (bb_in_sd_region (e->src, s))
1068 /* Create for all scop regions a single entry and a single exit edge. */
1071 create_sese_edges (VEC (sd_region, heap) *regions)
1076 for (i = 0; VEC_iterate (sd_region, regions, i, s); i++)
1077 create_single_entry_edge (s);
1079 mark_exit_edges (regions);
1081 for (i = 0; VEC_iterate (sd_region, regions, i, s); i++)
1082 create_single_exit_edge (s);
1084 unmark_exit_edges (regions);
1086 fix_loop_structure (NULL);
1088 #ifdef ENABLE_CHECKING
1089 verify_loop_structure ();
1090 verify_dominators (CDI_DOMINATORS);
1095 /* Create graphite SCoPs from an array of scop detection REGIONS. */
1098 build_graphite_scops (VEC (sd_region, heap) *regions,
1099 VEC (scop_p, heap) **scops)
1104 for (i = 0; VEC_iterate (sd_region, regions, i, s); i++)
1106 edge entry = find_single_entry_edge (s);
1107 edge exit = find_single_exit_edge (s);
1108 scop_p scop = new_scop (new_sese (entry, exit));
1109 VEC_safe_push (scop_p, heap, *scops, scop);
1111 /* Are there overlapping SCoPs? */
1112 #ifdef ENABLE_CHECKING
1117 for (j = 0; VEC_iterate (sd_region, regions, j, s2); j++)
1119 gcc_assert (!bb_in_sd_region (s->entry, s2));
1125 /* Returns true when BB contains only close phi nodes. */
1128 contains_only_close_phi_nodes (basic_block bb)
1130 gimple_stmt_iterator gsi;
1132 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1133 if (gimple_code (gsi_stmt (gsi)) != GIMPLE_LABEL)
1139 /* Print statistics for SCOP to FILE. */
1142 print_graphite_scop_statistics (FILE* file, scop_p scop)
1147 long n_conditions = 0;
1151 long n_p_conditions = 0;
1157 gimple_stmt_iterator psi;
1158 loop_p loop = bb->loop_father;
1160 if (!bb_in_sese_p (bb, SCOP_REGION (scop)))
1164 n_p_bbs += bb->count;
1166 if (VEC_length (edge, bb->succs) > 1)
1169 n_p_conditions += bb->count;
1172 for (psi = gsi_start_bb (bb); !gsi_end_p (psi); gsi_next (&psi))
1175 n_p_stmts += bb->count;
1178 if (loop->header == bb && loop_in_sese_p (loop, SCOP_REGION (scop)))
1181 n_p_loops += bb->count;
1186 fprintf (file, "\nBefore limit_scops SCoP statistics (");
1187 fprintf (file, "BBS:%ld, ", n_bbs);
1188 fprintf (file, "LOOPS:%ld, ", n_loops);
1189 fprintf (file, "CONDITIONS:%ld, ", n_conditions);
1190 fprintf (file, "STMTS:%ld)\n", n_stmts);
1191 fprintf (file, "\nBefore limit_scops SCoP profiling statistics (");
1192 fprintf (file, "BBS:%ld, ", n_p_bbs);
1193 fprintf (file, "LOOPS:%ld, ", n_p_loops);
1194 fprintf (file, "CONDITIONS:%ld, ", n_p_conditions);
1195 fprintf (file, "STMTS:%ld)\n", n_p_stmts);
1198 /* Print statistics for SCOPS to FILE. */
1201 print_graphite_statistics (FILE* file, VEC (scop_p, heap) *scops)
1206 for (i = 0; VEC_iterate (scop_p, scops, i, scop); i++)
1207 print_graphite_scop_statistics (file, scop);
1210 /* We limit all SCoPs to SCoPs, that are completely surrounded by a loop.
1220 * SCoP frontier, as this line is not surrounded by any loop. *
1224 This is necessary as scalar evolution and parameter detection need a
1225 outermost loop to initialize parameters correctly.
1227 TODO: FIX scalar evolution and parameter detection to allow more flexible
1231 limit_scops (VEC (scop_p, heap) **scops)
1233 VEC (sd_region, heap) *regions = VEC_alloc (sd_region, heap, 3);
1238 for (i = 0; VEC_iterate (scop_p, *scops, i, scop); i++)
1242 sese region = SCOP_REGION (scop);
1243 build_sese_loop_nests (region);
1245 for (j = 0; VEC_iterate (loop_p, SESE_LOOP_NEST (region), j, loop); j++)
1246 if (!loop_in_sese_p (loop_outer (loop), region)
1247 && single_exit (loop))
1249 sd_region open_scop;
1250 open_scop.entry = loop->header;
1251 open_scop.exit = single_exit (loop)->dest;
1253 /* This is a hack on top of the limit_scops hack. The
1254 limit_scops hack should disappear all together. */
1255 if (single_succ_p (open_scop.exit)
1256 && contains_only_close_phi_nodes (open_scop.exit))
1257 open_scop.exit = single_succ_edge (open_scop.exit)->dest;
1259 VEC_safe_push (sd_region, heap, regions, &open_scop);
1263 free_scops (*scops);
1264 *scops = VEC_alloc (scop_p, heap, 3);
1266 create_sese_edges (regions);
1267 build_graphite_scops (regions, scops);
1268 VEC_free (sd_region, heap, regions);
1271 /* Transforms LOOP to the canonical loop closed SSA form. */
1274 canonicalize_loop_closed_ssa (loop_p loop)
1276 edge e = single_exit (loop);
1279 if (!e || e->flags & EDGE_ABNORMAL)
1284 if (VEC_length (edge, bb->preds) == 1)
1285 split_block_after_labels (bb);
1288 gimple_stmt_iterator psi;
1289 basic_block close = split_edge (e);
1291 e = single_succ_edge (close);
1293 for (psi = gsi_start_phis (bb); !gsi_end_p (psi); gsi_next (&psi))
1295 gimple phi = gsi_stmt (psi);
1298 for (i = 0; i < gimple_phi_num_args (phi); i++)
1299 if (gimple_phi_arg_edge (phi, i) == e)
1301 tree res, arg = gimple_phi_arg_def (phi, i);
1302 use_operand_p use_p;
1305 if (TREE_CODE (arg) != SSA_NAME)
1308 close_phi = create_phi_node (arg, close);
1309 res = create_new_def_for (gimple_phi_result (close_phi),
1311 gimple_phi_result_ptr (close_phi));
1312 add_phi_arg (close_phi, arg,
1313 gimple_phi_arg_edge (close_phi, 0),
1315 use_p = gimple_phi_arg_imm_use_ptr (phi, i);
1316 replace_exp (use_p, res);
1323 /* Converts the current loop closed SSA form to a canonical form
1324 expected by the Graphite code generation.
1326 The loop closed SSA form has the following invariant: a variable
1327 defined in a loop that is used outside the loop appears only in the
1328 phi nodes in the destination of the loop exit. These phi nodes are
1329 called close phi nodes.
1331 The canonical loop closed SSA form contains the extra invariants:
1333 - when the loop contains only one exit, the close phi nodes contain
1334 only one argument. That implies that the basic block that contains
1335 the close phi nodes has only one predecessor, that is a basic block
1338 - the basic block containing the close phi nodes does not contain
1343 canonicalize_loop_closed_ssa_form (void)
1348 #ifdef ENABLE_CHECKING
1349 verify_loop_closed_ssa ();
1352 FOR_EACH_LOOP (li, loop, 0)
1353 canonicalize_loop_closed_ssa (loop);
1355 rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
1356 update_ssa (TODO_update_ssa);
1358 #ifdef ENABLE_CHECKING
1359 verify_loop_closed_ssa ();
1363 /* Find Static Control Parts (SCoP) in the current function and pushes
1367 build_scops (VEC (scop_p, heap) **scops)
1369 struct loop *loop = current_loops->tree_root;
1370 VEC (sd_region, heap) *regions = VEC_alloc (sd_region, heap, 3);
1372 canonicalize_loop_closed_ssa_form ();
1373 build_scops_1 (single_succ (ENTRY_BLOCK_PTR), ENTRY_BLOCK_PTR->loop_father,
1375 create_sese_edges (regions);
1376 build_graphite_scops (regions, scops);
1378 if (dump_file && (dump_flags & TDF_DETAILS))
1379 print_graphite_statistics (dump_file, *scops);
1381 limit_scops (scops);
1382 VEC_free (sd_region, heap, regions);
1384 if (dump_file && (dump_flags & TDF_DETAILS))
1385 fprintf (dump_file, "\nnumber of SCoPs: %d\n",
1386 VEC_length (scop_p, *scops));
1389 /* Pretty print to FILE all the SCoPs in DOT format and mark them with
1390 different colors. If there are not enough colors, paint the
1391 remaining SCoPs in gray.
1394 - "*" after the node number denotes the entry of a SCoP,
1395 - "#" after the node number denotes the exit of a SCoP,
1396 - "()" around the node number denotes the entry or the
1397 exit nodes of the SCOP. These are not part of SCoP. */
1400 dot_all_scops_1 (FILE *file, VEC (scop_p, heap) *scops)
1409 /* Disable debugging while printing graph. */
1410 int tmp_dump_flags = dump_flags;
1413 fprintf (file, "digraph all {\n");
1417 int part_of_scop = false;
1419 /* Use HTML for every bb label. So we are able to print bbs
1420 which are part of two different SCoPs, with two different
1421 background colors. */
1422 fprintf (file, "%d [label=<\n <TABLE BORDER=\"0\" CELLBORDER=\"1\" ",
1424 fprintf (file, "CELLSPACING=\"0\">\n");
1426 /* Select color for SCoP. */
1427 for (i = 0; VEC_iterate (scop_p, scops, i, scop); i++)
1429 sese region = SCOP_REGION (scop);
1430 if (bb_in_sese_p (bb, region)
1431 || (SESE_EXIT_BB (region) == bb)
1432 || (SESE_ENTRY_BB (region) == bb))
1445 case 3: /* purple */
1448 case 4: /* orange */
1451 case 5: /* yellow */
1491 fprintf (file, " <TR><TD WIDTH=\"50\" BGCOLOR=\"%s\">", color);
1493 if (!bb_in_sese_p (bb, region))
1494 fprintf (file, " (");
1496 if (bb == SESE_ENTRY_BB (region)
1497 && bb == SESE_EXIT_BB (region))
1498 fprintf (file, " %d*# ", bb->index);
1499 else if (bb == SESE_ENTRY_BB (region))
1500 fprintf (file, " %d* ", bb->index);
1501 else if (bb == SESE_EXIT_BB (region))
1502 fprintf (file, " %d# ", bb->index);
1504 fprintf (file, " %d ", bb->index);
1506 if (!bb_in_sese_p (bb,region))
1507 fprintf (file, ")");
1509 fprintf (file, "</TD></TR>\n");
1510 part_of_scop = true;
1516 fprintf (file, " <TR><TD WIDTH=\"50\" BGCOLOR=\"#ffffff\">");
1517 fprintf (file, " %d </TD></TR>\n", bb->index);
1519 fprintf (file, " </TABLE>>, shape=box, style=\"setlinewidth(0)\"]\n");
1524 FOR_EACH_EDGE (e, ei, bb->succs)
1525 fprintf (file, "%d -> %d;\n", bb->index, e->dest->index);
1528 fputs ("}\n\n", file);
1530 /* Enable debugging again. */
1531 dump_flags = tmp_dump_flags;
1534 /* Display all SCoPs using dotty. */
1537 dot_all_scops (VEC (scop_p, heap) *scops)
1539 /* When debugging, enable the following code. This cannot be used
1540 in production compilers because it calls "system". */
1543 FILE *stream = fopen ("/tmp/allscops.dot", "w");
1544 gcc_assert (stream);
1546 dot_all_scops_1 (stream, scops);
1549 x = system ("dotty /tmp/allscops.dot");
1551 dot_all_scops_1 (stderr, scops);
1555 /* Display all SCoPs using dotty. */
1558 dot_scop (scop_p scop)
1560 VEC (scop_p, heap) *scops = NULL;
1563 VEC_safe_push (scop_p, heap, scops, scop);
1565 /* When debugging, enable the following code. This cannot be used
1566 in production compilers because it calls "system". */
1570 FILE *stream = fopen ("/tmp/allscops.dot", "w");
1571 gcc_assert (stream);
1573 dot_all_scops_1 (stream, scops);
1575 x = system ("dotty /tmp/allscops.dot");
1578 dot_all_scops_1 (stderr, scops);
1581 VEC_free (scop_p, heap, scops);