1 /* Detection of Static Control Parts (SCoP) for Graphite.
2 Copyright (C) 2009, 2010, 2011 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/>. */
27 #include <isl/union_map.h>
28 #include <cloog/cloog.h>
29 #include <cloog/isl/domain.h>
33 #include "coretypes.h"
34 #include "tree-flow.h"
36 #include "tree-chrec.h"
37 #include "tree-data-ref.h"
38 #include "tree-scalar-evolution.h"
39 #include "tree-pass.h"
43 #include "graphite-poly.h"
44 #include "graphite-scop-detection.h"
46 /* Forward declarations. */
47 static void make_close_phi_nodes_unique (basic_block
);
49 /* The type of the analyzed basic block. */
51 typedef enum gbb_type
{
53 GBB_LOOP_SING_EXIT_HEADER
,
54 GBB_LOOP_MULT_EXIT_HEADER
,
61 /* Detect the type of BB. Loop headers are only marked, if they are
62 new. This means their loop_father is different to LAST_LOOP.
63 Otherwise they are treated like any other bb and their type can be
67 get_bb_type (basic_block bb
, struct loop
*last_loop
)
69 VEC (basic_block
, heap
) *dom
;
71 struct loop
*loop
= bb
->loop_father
;
73 /* Check, if we entry into a new loop. */
74 if (loop
!= last_loop
)
76 if (single_exit (loop
) != NULL
)
77 return GBB_LOOP_SING_EXIT_HEADER
;
78 else if (loop
->num
!= 0)
79 return GBB_LOOP_MULT_EXIT_HEADER
;
81 return GBB_COND_HEADER
;
84 dom
= get_dominated_by (CDI_DOMINATORS
, bb
);
85 nb_dom
= VEC_length (basic_block
, dom
);
86 VEC_free (basic_block
, heap
, dom
);
91 nb_suc
= VEC_length (edge
, bb
->succs
);
93 if (nb_dom
== 1 && nb_suc
== 1)
96 return GBB_COND_HEADER
;
99 /* A SCoP detection region, defined using bbs as borders.
101 All control flow touching this region, comes in passing basic_block
102 ENTRY and leaves passing basic_block EXIT. By using bbs instead of
103 edges for the borders we are able to represent also regions that do
104 not have a single entry or exit edge.
106 But as they have a single entry basic_block and a single exit
107 basic_block, we are able to generate for every sd_region a single
115 / \ This region contains: {3, 4, 5, 6, 7, 8}
123 typedef struct sd_region_p
125 /* The entry bb dominates all bbs in the sd_region. It is part of
129 /* The exit bb postdominates all bbs in the sd_region, but is not
130 part of the region. */
134 DEF_VEC_O(sd_region
);
135 DEF_VEC_ALLOC_O(sd_region
, heap
);
138 /* Moves the scops from SOURCE to TARGET and clean up SOURCE. */
141 move_sd_regions (VEC (sd_region
, heap
) **source
,
142 VEC (sd_region
, heap
) **target
)
147 FOR_EACH_VEC_ELT (sd_region
, *source
, i
, s
)
148 VEC_safe_push (sd_region
, heap
, *target
, s
);
150 VEC_free (sd_region
, heap
, *source
);
153 /* Something like "n * m" is not allowed. */
156 graphite_can_represent_init (tree e
)
158 switch (TREE_CODE (e
))
160 case POLYNOMIAL_CHREC
:
161 return graphite_can_represent_init (CHREC_LEFT (e
))
162 && graphite_can_represent_init (CHREC_RIGHT (e
));
165 if (chrec_contains_symbols (TREE_OPERAND (e
, 0)))
166 return graphite_can_represent_init (TREE_OPERAND (e
, 0))
167 && host_integerp (TREE_OPERAND (e
, 1), 0);
169 return graphite_can_represent_init (TREE_OPERAND (e
, 1))
170 && host_integerp (TREE_OPERAND (e
, 0), 0);
173 case POINTER_PLUS_EXPR
:
175 return graphite_can_represent_init (TREE_OPERAND (e
, 0))
176 && graphite_can_represent_init (TREE_OPERAND (e
, 1));
181 case NON_LVALUE_EXPR
:
182 return graphite_can_represent_init (TREE_OPERAND (e
, 0));
191 /* Return true when SCEV can be represented in the polyhedral model.
193 An expression can be represented, if it can be expressed as an
194 affine expression. For loops (i, j) and parameters (m, n) all
195 affine expressions are of the form:
197 x1 * i + x2 * j + x3 * m + x4 * n + x5 * 1 where x1..x5 element of Z
199 1 i + 20 j + (-2) m + 25
201 Something like "i * n" or "n * m" is not allowed. */
204 graphite_can_represent_scev (tree scev
)
206 if (chrec_contains_undetermined (scev
))
209 switch (TREE_CODE (scev
))
213 return graphite_can_represent_scev (TREE_OPERAND (scev
, 0))
214 && graphite_can_represent_scev (TREE_OPERAND (scev
, 1));
217 return !CONVERT_EXPR_CODE_P (TREE_CODE (TREE_OPERAND (scev
, 0)))
218 && !CONVERT_EXPR_CODE_P (TREE_CODE (TREE_OPERAND (scev
, 1)))
219 && !(chrec_contains_symbols (TREE_OPERAND (scev
, 0))
220 && chrec_contains_symbols (TREE_OPERAND (scev
, 1)))
221 && graphite_can_represent_init (scev
)
222 && graphite_can_represent_scev (TREE_OPERAND (scev
, 0))
223 && graphite_can_represent_scev (TREE_OPERAND (scev
, 1));
225 case POLYNOMIAL_CHREC
:
226 /* Check for constant strides. With a non constant stride of
227 'n' we would have a value of 'iv * n'. Also check that the
228 initial value can represented: for example 'n * m' cannot be
230 if (!evolution_function_right_is_integer_cst (scev
)
231 || !graphite_can_represent_init (scev
))
238 /* Only affine functions can be represented. */
239 if (!scev_is_linear_expression (scev
))
246 /* Return true when EXPR can be represented in the polyhedral model.
248 This means an expression can be represented, if it is linear with
249 respect to the loops and the strides are non parametric.
250 LOOP is the place where the expr will be evaluated. SCOP_ENTRY defines the
251 entry of the region we analyse. */
254 graphite_can_represent_expr (basic_block scop_entry
, loop_p loop
,
257 tree scev
= analyze_scalar_evolution (loop
, expr
);
259 scev
= instantiate_scev (scop_entry
, loop
, scev
);
261 return graphite_can_represent_scev (scev
);
264 /* Return true if the data references of STMT can be represented by
268 stmt_has_simple_data_refs_p (loop_p outermost_loop ATTRIBUTE_UNUSED
,
275 VEC (data_reference_p
, heap
) *drs
= NULL
;
278 for (outer
= loop_containing_stmt (stmt
); outer
; outer
= loop_outer (outer
))
280 graphite_find_data_references_in_stmt (outer
,
281 loop_containing_stmt (stmt
),
284 FOR_EACH_VEC_ELT (data_reference_p
, drs
, j
, dr
)
285 for (i
= 0; i
< DR_NUM_DIMENSIONS (dr
); i
++)
286 if (!graphite_can_represent_scev (DR_ACCESS_FN (dr
, i
)))
292 free_data_refs (drs
);
297 free_data_refs (drs
);
301 /* Return true only when STMT is simple enough for being handled by
302 Graphite. This depends on SCOP_ENTRY, as the parameters are
303 initialized relatively to this basic block, the linear functions
304 are initialized to OUTERMOST_LOOP and BB is the place where we try
305 to evaluate the STMT. */
308 stmt_simple_for_scop_p (basic_block scop_entry
, loop_p outermost_loop
,
309 gimple stmt
, basic_block bb
)
311 loop_p loop
= bb
->loop_father
;
313 gcc_assert (scop_entry
);
315 /* GIMPLE_ASM and GIMPLE_CALL may embed arbitrary side effects.
316 Calls have side-effects, except those to const or pure
318 if (gimple_has_volatile_ops (stmt
)
319 || (gimple_code (stmt
) == GIMPLE_CALL
320 && !(gimple_call_flags (stmt
) & (ECF_CONST
| ECF_PURE
)))
321 || (gimple_code (stmt
) == GIMPLE_ASM
))
324 if (is_gimple_debug (stmt
))
327 if (!stmt_has_simple_data_refs_p (outermost_loop
, stmt
))
330 switch (gimple_code (stmt
))
340 enum tree_code code
= gimple_cond_code (stmt
);
342 /* We can handle all binary comparisons. Inequalities are
343 also supported as they can be represented with union of
345 if (!(code
== LT_EXPR
353 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, op_iter
, SSA_OP_ALL_USES
)
354 if (!graphite_can_represent_expr (scop_entry
, loop
, op
)
355 /* We can not handle REAL_TYPE. Failed for pr39260. */
356 || TREE_CODE (TREE_TYPE (op
)) == REAL_TYPE
)
367 /* These nodes cut a new scope. */
374 /* Returns the statement of BB that contains a harmful operation: that
375 can be a function call with side effects, the induction variables
376 are not linear with respect to SCOP_ENTRY, etc. The current open
377 scop should end before this statement. The evaluation is limited using
378 OUTERMOST_LOOP as outermost loop that may change. */
381 harmful_stmt_in_bb (basic_block scop_entry
, loop_p outer_loop
, basic_block bb
)
383 gimple_stmt_iterator gsi
;
385 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
386 if (!stmt_simple_for_scop_p (scop_entry
, outer_loop
, gsi_stmt (gsi
), bb
))
387 return gsi_stmt (gsi
);
392 /* Return true if LOOP can be represented in the polyhedral
393 representation. This is evaluated taking SCOP_ENTRY and
394 OUTERMOST_LOOP in mind. */
397 graphite_can_represent_loop (basic_block scop_entry
, loop_p loop
)
400 struct tree_niter_desc niter_desc
;
402 /* FIXME: For the moment, graphite cannot be used on loops that
403 iterate using induction variables that wrap. */
405 return number_of_iterations_exit (loop
, single_exit (loop
), &niter_desc
, false)
406 && niter_desc
.control
.no_overflow
407 && (niter
= number_of_latch_executions (loop
))
408 && !chrec_contains_undetermined (niter
)
409 && graphite_can_represent_expr (scop_entry
, loop
, niter
);
412 /* Store information needed by scopdet_* functions. */
416 /* Exit of the open scop would stop if the current BB is harmful. */
419 /* Where the next scop would start if the current BB is harmful. */
422 /* The bb or one of its children contains open loop exits. That means
423 loop exit nodes that are not surrounded by a loop dominated by bb. */
426 /* The bb or one of its children contains only structures we can handle. */
430 static struct scopdet_info
build_scops_1 (basic_block
, loop_p
,
431 VEC (sd_region
, heap
) **, loop_p
);
433 /* Calculates BB infos. If bb is difficult we add valid SCoPs dominated by BB
434 to SCOPS. TYPE is the gbb_type of BB. */
436 static struct scopdet_info
437 scopdet_basic_block_info (basic_block bb
, loop_p outermost_loop
,
438 VEC (sd_region
, heap
) **scops
, gbb_type type
)
440 loop_p loop
= bb
->loop_father
;
441 struct scopdet_info result
;
444 /* XXX: ENTRY_BLOCK_PTR could be optimized in later steps. */
445 basic_block entry_block
= ENTRY_BLOCK_PTR
;
446 stmt
= harmful_stmt_in_bb (entry_block
, outermost_loop
, bb
);
447 result
.difficult
= (stmt
!= NULL
);
454 result
.exits
= false;
456 /* Mark bbs terminating a SESE region difficult, if they start
458 if (!single_succ_p (bb
))
459 result
.difficult
= true;
461 result
.exit
= single_succ (bb
);
466 result
.next
= single_succ (bb
);
467 result
.exits
= false;
468 result
.exit
= single_succ (bb
);
471 case GBB_LOOP_SING_EXIT_HEADER
:
473 VEC (sd_region
, heap
) *regions
= VEC_alloc (sd_region
, heap
, 3);
474 struct scopdet_info sinfo
;
475 edge exit_e
= single_exit (loop
);
477 sinfo
= build_scops_1 (bb
, outermost_loop
, ®ions
, loop
);
479 if (!graphite_can_represent_loop (entry_block
, loop
))
480 result
.difficult
= true;
482 result
.difficult
|= sinfo
.difficult
;
484 /* Try again with another loop level. */
486 && loop_depth (outermost_loop
) + 1 == loop_depth (loop
))
488 outermost_loop
= loop
;
490 VEC_free (sd_region
, heap
, regions
);
491 regions
= VEC_alloc (sd_region
, heap
, 3);
493 sinfo
= scopdet_basic_block_info (bb
, outermost_loop
, scops
, type
);
496 result
.difficult
= true;
499 move_sd_regions (®ions
, scops
);
503 open_scop
.entry
= bb
;
504 open_scop
.exit
= exit_e
->dest
;
505 VEC_safe_push (sd_region
, heap
, *scops
, &open_scop
);
506 VEC_free (sd_region
, heap
, regions
);
511 result
.exit
= exit_e
->dest
;
512 result
.next
= exit_e
->dest
;
514 /* If we do not dominate result.next, remove it. It's either
515 the EXIT_BLOCK_PTR, or another bb dominates it and will
516 call the scop detection for this bb. */
517 if (!dominated_by_p (CDI_DOMINATORS
, result
.next
, bb
))
520 if (exit_e
->src
->loop_father
!= loop
)
523 result
.exits
= false;
525 if (result
.difficult
)
526 move_sd_regions (®ions
, scops
);
528 VEC_free (sd_region
, heap
, regions
);
534 case GBB_LOOP_MULT_EXIT_HEADER
:
536 /* XXX: For now we just do not join loops with multiple exits. If the
537 exits lead to the same bb it may be possible to join the loop. */
538 VEC (sd_region
, heap
) *regions
= VEC_alloc (sd_region
, heap
, 3);
539 VEC (edge
, heap
) *exits
= get_loop_exit_edges (loop
);
542 build_scops_1 (bb
, loop
, ®ions
, loop
);
544 /* Scan the code dominated by this loop. This means all bbs, that are
545 are dominated by a bb in this loop, but are not part of this loop.
548 - The loop exit destination is dominated by the exit sources.
550 TODO: We miss here the more complex cases:
551 - The exit destinations are dominated by another bb inside
553 - The loop dominates bbs, that are not exit destinations. */
554 FOR_EACH_VEC_ELT (edge
, exits
, i
, e
)
555 if (e
->src
->loop_father
== loop
556 && dominated_by_p (CDI_DOMINATORS
, e
->dest
, e
->src
))
558 if (loop_outer (outermost_loop
))
559 outermost_loop
= loop_outer (outermost_loop
);
561 /* Pass loop_outer to recognize e->dest as loop header in
563 if (e
->dest
->loop_father
->header
== e
->dest
)
564 build_scops_1 (e
->dest
, outermost_loop
, ®ions
,
565 loop_outer (e
->dest
->loop_father
));
567 build_scops_1 (e
->dest
, outermost_loop
, ®ions
,
568 e
->dest
->loop_father
);
573 result
.difficult
= true;
574 result
.exits
= false;
575 move_sd_regions (®ions
, scops
);
576 VEC_free (edge
, heap
, exits
);
579 case GBB_COND_HEADER
:
581 VEC (sd_region
, heap
) *regions
= VEC_alloc (sd_region
, heap
, 3);
582 struct scopdet_info sinfo
;
583 VEC (basic_block
, heap
) *dominated
;
586 basic_block last_exit
= NULL
;
588 result
.exits
= false;
590 /* First check the successors of BB, and check if it is
591 possible to join the different branches. */
592 FOR_EACH_VEC_ELT (edge
, bb
->succs
, i
, e
)
594 /* Ignore loop exits. They will be handled after the loop
596 if (loop_exits_to_bb_p (loop
, e
->dest
))
602 /* Do not follow edges that lead to the end of the
603 conditions block. For example, in
613 the edge from 0 => 6. Only check if all paths lead to
616 if (!single_pred_p (e
->dest
))
618 /* Check, if edge leads directly to the end of this
623 if (e
->dest
!= last_exit
)
624 result
.difficult
= true;
629 if (!dominated_by_p (CDI_DOMINATORS
, e
->dest
, bb
))
631 result
.difficult
= true;
635 sinfo
= build_scops_1 (e
->dest
, outermost_loop
, ®ions
, loop
);
637 result
.exits
|= sinfo
.exits
;
638 result
.difficult
|= sinfo
.difficult
;
640 /* Checks, if all branches end at the same point.
641 If that is true, the condition stays joinable.
642 Have a look at the example above. */
646 last_exit
= sinfo
.exit
;
648 if (sinfo
.exit
!= last_exit
)
649 result
.difficult
= true;
652 result
.difficult
= true;
656 result
.difficult
= true;
658 /* Join the branches of the condition if possible. */
659 if (!result
.exits
&& !result
.difficult
)
661 /* Only return a next pointer if we dominate this pointer.
662 Otherwise it will be handled by the bb dominating it. */
663 if (dominated_by_p (CDI_DOMINATORS
, last_exit
, bb
)
665 result
.next
= last_exit
;
669 result
.exit
= last_exit
;
671 VEC_free (sd_region
, heap
, regions
);
675 /* Scan remaining bbs dominated by BB. */
676 dominated
= get_dominated_by (CDI_DOMINATORS
, bb
);
678 FOR_EACH_VEC_ELT (basic_block
, dominated
, i
, dom_bb
)
680 /* Ignore loop exits: they will be handled after the loop body. */
681 if (loop_depth (find_common_loop (loop
, dom_bb
->loop_father
))
688 /* Ignore the bbs processed above. */
689 if (single_pred_p (dom_bb
) && single_pred (dom_bb
) == bb
)
692 if (loop_depth (loop
) > loop_depth (dom_bb
->loop_father
))
693 sinfo
= build_scops_1 (dom_bb
, outermost_loop
, ®ions
,
696 sinfo
= build_scops_1 (dom_bb
, outermost_loop
, ®ions
, loop
);
698 result
.exits
|= sinfo
.exits
;
699 result
.difficult
= true;
703 VEC_free (basic_block
, heap
, dominated
);
706 move_sd_regions (®ions
, scops
);
718 /* Starting from CURRENT we walk the dominance tree and add new sd_regions to
719 SCOPS. The analyse if a sd_region can be handled is based on the value
720 of OUTERMOST_LOOP. Only loops inside OUTERMOST loops may change. LOOP
721 is the loop in which CURRENT is handled.
723 TODO: These functions got a little bit big. They definitely should be cleaned
726 static struct scopdet_info
727 build_scops_1 (basic_block current
, loop_p outermost_loop
,
728 VEC (sd_region
, heap
) **scops
, loop_p loop
)
730 bool in_scop
= false;
732 struct scopdet_info sinfo
;
734 /* Initialize result. */
735 struct scopdet_info result
;
736 result
.exits
= false;
737 result
.difficult
= false;
740 open_scop
.entry
= NULL
;
741 open_scop
.exit
= NULL
;
744 /* Loop over the dominance tree. If we meet a difficult bb, close
745 the current SCoP. Loop and condition header start a new layer,
746 and can only be added if all bbs in deeper layers are simple. */
747 while (current
!= NULL
)
749 sinfo
= scopdet_basic_block_info (current
, outermost_loop
, scops
,
750 get_bb_type (current
, loop
));
752 if (!in_scop
&& !(sinfo
.exits
|| sinfo
.difficult
))
754 open_scop
.entry
= current
;
755 open_scop
.exit
= NULL
;
758 else if (in_scop
&& (sinfo
.exits
|| sinfo
.difficult
))
760 open_scop
.exit
= current
;
761 VEC_safe_push (sd_region
, heap
, *scops
, &open_scop
);
765 result
.difficult
|= sinfo
.difficult
;
766 result
.exits
|= sinfo
.exits
;
768 current
= sinfo
.next
;
771 /* Try to close open_scop, if we are still in an open SCoP. */
774 open_scop
.exit
= sinfo
.exit
;
775 gcc_assert (open_scop
.exit
);
776 VEC_safe_push (sd_region
, heap
, *scops
, &open_scop
);
779 result
.exit
= sinfo
.exit
;
783 /* Checks if a bb is contained in REGION. */
786 bb_in_sd_region (basic_block bb
, sd_region
*region
)
788 return bb_in_region (bb
, region
->entry
, region
->exit
);
791 /* Returns the single entry edge of REGION, if it does not exits NULL. */
794 find_single_entry_edge (sd_region
*region
)
800 FOR_EACH_EDGE (e
, ei
, region
->entry
->preds
)
801 if (!bb_in_sd_region (e
->src
, region
))
816 /* Returns the single exit edge of REGION, if it does not exits NULL. */
819 find_single_exit_edge (sd_region
*region
)
825 FOR_EACH_EDGE (e
, ei
, region
->exit
->preds
)
826 if (bb_in_sd_region (e
->src
, region
))
841 /* Create a single entry edge for REGION. */
844 create_single_entry_edge (sd_region
*region
)
846 if (find_single_entry_edge (region
))
849 /* There are multiple predecessors for bb_3
862 There are two edges (1->3, 2->3), that point from outside into the region,
863 and another one (5->3), a loop latch, lead to bb_3.
871 | |\ (3.0 -> 3.1) = single entry edge
880 If the loop is part of the SCoP, we have to redirect the loop latches.
886 | | (3.0 -> 3.1) = entry edge
895 if (region
->entry
->loop_father
->header
!= region
->entry
896 || dominated_by_p (CDI_DOMINATORS
,
897 loop_latch_edge (region
->entry
->loop_father
)->src
,
900 edge forwarder
= split_block_after_labels (region
->entry
);
901 region
->entry
= forwarder
->dest
;
904 /* This case is never executed, as the loop headers seem always to have a
905 single edge pointing from outside into the loop. */
908 gcc_checking_assert (find_single_entry_edge (region
));
911 /* Check if the sd_region, mentioned in EDGE, has no exit bb. */
914 sd_region_without_exit (edge e
)
916 sd_region
*r
= (sd_region
*) e
->aux
;
919 return r
->exit
== NULL
;
924 /* Create a single exit edge for REGION. */
927 create_single_exit_edge (sd_region
*region
)
931 edge forwarder
= NULL
;
934 /* We create a forwarder bb (5) for all edges leaving this region
935 (3->5, 4->5). All other edges leading to the same bb, are moved
936 to a new bb (6). If these edges where part of another region (2->5)
937 we update the region->exit pointer, of this region.
939 To identify which edge belongs to which region we depend on the e->aux
940 pointer in every edge. It points to the region of the edge or to NULL,
941 if the edge is not part of any region.
943 1 2 3 4 1->5 no region, 2->5 region->exit = 5,
944 \| |/ 3->5 region->exit = NULL, 4->5 region->exit = NULL
949 1 2 3 4 1->6 no region, 2->6 region->exit = 6,
950 | | \/ 3->5 no region, 4->5 no region,
952 \| / 5->6 region->exit = 6
955 Now there is only a single exit edge (5->6). */
958 forwarder
= make_forwarder_block (exit
, &sd_region_without_exit
, NULL
);
960 /* Unmark the edges, that are no longer exit edges. */
961 FOR_EACH_EDGE (e
, ei
, forwarder
->src
->preds
)
965 /* Mark the new exit edge. */
966 single_succ_edge (forwarder
->src
)->aux
= region
;
968 /* Update the exit bb of all regions, where exit edges lead to
970 FOR_EACH_EDGE (e
, ei
, forwarder
->dest
->preds
)
972 ((sd_region
*) e
->aux
)->exit
= forwarder
->dest
;
974 gcc_checking_assert (find_single_exit_edge (region
));
977 /* Unmark the exit edges of all REGIONS.
978 See comment in "create_single_exit_edge". */
981 unmark_exit_edges (VEC (sd_region
, heap
) *regions
)
988 FOR_EACH_VEC_ELT (sd_region
, regions
, i
, s
)
989 FOR_EACH_EDGE (e
, ei
, s
->exit
->preds
)
994 /* Mark the exit edges of all REGIONS.
995 See comment in "create_single_exit_edge". */
998 mark_exit_edges (VEC (sd_region
, heap
) *regions
)
1005 FOR_EACH_VEC_ELT (sd_region
, regions
, i
, s
)
1006 FOR_EACH_EDGE (e
, ei
, s
->exit
->preds
)
1007 if (bb_in_sd_region (e
->src
, s
))
1011 /* Create for all scop regions a single entry and a single exit edge. */
1014 create_sese_edges (VEC (sd_region
, heap
) *regions
)
1019 FOR_EACH_VEC_ELT (sd_region
, regions
, i
, s
)
1020 create_single_entry_edge (s
);
1022 mark_exit_edges (regions
);
1024 FOR_EACH_VEC_ELT (sd_region
, regions
, i
, s
)
1025 /* Don't handle multiple edges exiting the function. */
1026 if (!find_single_exit_edge (s
)
1027 && s
->exit
!= EXIT_BLOCK_PTR
)
1028 create_single_exit_edge (s
);
1030 unmark_exit_edges (regions
);
1032 calculate_dominance_info (CDI_DOMINATORS
);
1033 fix_loop_structure (NULL
);
1035 #ifdef ENABLE_CHECKING
1036 verify_loop_structure ();
1041 /* Create graphite SCoPs from an array of scop detection REGIONS. */
1044 build_graphite_scops (VEC (sd_region
, heap
) *regions
,
1045 VEC (scop_p
, heap
) **scops
)
1050 FOR_EACH_VEC_ELT (sd_region
, regions
, i
, s
)
1052 edge entry
= find_single_entry_edge (s
);
1053 edge exit
= find_single_exit_edge (s
);
1059 scop
= new_scop (new_sese (entry
, exit
));
1060 VEC_safe_push (scop_p
, heap
, *scops
, scop
);
1062 /* Are there overlapping SCoPs? */
1063 #ifdef ENABLE_CHECKING
1068 FOR_EACH_VEC_ELT (sd_region
, regions
, j
, s2
)
1070 gcc_assert (!bb_in_sd_region (s
->entry
, s2
));
1076 /* Returns true when BB contains only close phi nodes. */
1079 contains_only_close_phi_nodes (basic_block bb
)
1081 gimple_stmt_iterator gsi
;
1083 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
1084 if (gimple_code (gsi_stmt (gsi
)) != GIMPLE_LABEL
)
1090 /* Print statistics for SCOP to FILE. */
1093 print_graphite_scop_statistics (FILE* file
, scop_p scop
)
1098 long n_conditions
= 0;
1102 long n_p_conditions
= 0;
1108 gimple_stmt_iterator psi
;
1109 loop_p loop
= bb
->loop_father
;
1111 if (!bb_in_sese_p (bb
, SCOP_REGION (scop
)))
1115 n_p_bbs
+= bb
->count
;
1117 if (VEC_length (edge
, bb
->succs
) > 1)
1120 n_p_conditions
+= bb
->count
;
1123 for (psi
= gsi_start_bb (bb
); !gsi_end_p (psi
); gsi_next (&psi
))
1126 n_p_stmts
+= bb
->count
;
1129 if (loop
->header
== bb
&& loop_in_sese_p (loop
, SCOP_REGION (scop
)))
1132 n_p_loops
+= bb
->count
;
1137 fprintf (file
, "\nBefore limit_scops SCoP statistics (");
1138 fprintf (file
, "BBS:%ld, ", n_bbs
);
1139 fprintf (file
, "LOOPS:%ld, ", n_loops
);
1140 fprintf (file
, "CONDITIONS:%ld, ", n_conditions
);
1141 fprintf (file
, "STMTS:%ld)\n", n_stmts
);
1142 fprintf (file
, "\nBefore limit_scops SCoP profiling statistics (");
1143 fprintf (file
, "BBS:%ld, ", n_p_bbs
);
1144 fprintf (file
, "LOOPS:%ld, ", n_p_loops
);
1145 fprintf (file
, "CONDITIONS:%ld, ", n_p_conditions
);
1146 fprintf (file
, "STMTS:%ld)\n", n_p_stmts
);
1149 /* Print statistics for SCOPS to FILE. */
1152 print_graphite_statistics (FILE* file
, VEC (scop_p
, heap
) *scops
)
1157 FOR_EACH_VEC_ELT (scop_p
, scops
, i
, scop
)
1158 print_graphite_scop_statistics (file
, scop
);
1161 /* We limit all SCoPs to SCoPs, that are completely surrounded by a loop.
1171 * SCoP frontier, as this line is not surrounded by any loop. *
1175 This is necessary as scalar evolution and parameter detection need a
1176 outermost loop to initialize parameters correctly.
1178 TODO: FIX scalar evolution and parameter detection to allow more flexible
1182 limit_scops (VEC (scop_p
, heap
) **scops
)
1184 VEC (sd_region
, heap
) *regions
= VEC_alloc (sd_region
, heap
, 3);
1189 FOR_EACH_VEC_ELT (scop_p
, *scops
, i
, scop
)
1193 sese region
= SCOP_REGION (scop
);
1194 build_sese_loop_nests (region
);
1196 FOR_EACH_VEC_ELT (loop_p
, SESE_LOOP_NEST (region
), j
, loop
)
1197 if (!loop_in_sese_p (loop_outer (loop
), region
)
1198 && single_exit (loop
))
1200 sd_region open_scop
;
1201 open_scop
.entry
= loop
->header
;
1202 open_scop
.exit
= single_exit (loop
)->dest
;
1204 /* This is a hack on top of the limit_scops hack. The
1205 limit_scops hack should disappear all together. */
1206 if (single_succ_p (open_scop
.exit
)
1207 && contains_only_close_phi_nodes (open_scop
.exit
))
1208 open_scop
.exit
= single_succ_edge (open_scop
.exit
)->dest
;
1210 VEC_safe_push (sd_region
, heap
, regions
, &open_scop
);
1214 free_scops (*scops
);
1215 *scops
= VEC_alloc (scop_p
, heap
, 3);
1217 create_sese_edges (regions
);
1218 build_graphite_scops (regions
, scops
);
1219 VEC_free (sd_region
, heap
, regions
);
1222 /* Returns true when P1 and P2 are close phis with the same
1226 same_close_phi_node (gimple p1
, gimple p2
)
1228 return operand_equal_p (gimple_phi_arg_def (p1
, 0),
1229 gimple_phi_arg_def (p2
, 0), 0);
1232 /* Remove the close phi node at GSI and replace its rhs with the rhs
1236 remove_duplicate_close_phi (gimple phi
, gimple_stmt_iterator
*gsi
)
1239 use_operand_p use_p
;
1240 imm_use_iterator imm_iter
;
1241 tree res
= gimple_phi_result (phi
);
1242 tree def
= gimple_phi_result (gsi_stmt (*gsi
));
1244 gcc_assert (same_close_phi_node (phi
, gsi_stmt (*gsi
)));
1246 FOR_EACH_IMM_USE_STMT (use_stmt
, imm_iter
, def
)
1248 FOR_EACH_IMM_USE_ON_STMT (use_p
, imm_iter
)
1249 SET_USE (use_p
, res
);
1251 update_stmt (use_stmt
);
1253 /* It is possible that we just created a duplicate close-phi
1254 for an already-processed containing loop. Check for this
1255 case and clean it up. */
1256 if (gimple_code (use_stmt
) == GIMPLE_PHI
1257 && gimple_phi_num_args (use_stmt
) == 1)
1258 make_close_phi_nodes_unique (gimple_bb (use_stmt
));
1261 remove_phi_node (gsi
, true);
1264 /* Removes all the close phi duplicates from BB. */
1267 make_close_phi_nodes_unique (basic_block bb
)
1269 gimple_stmt_iterator psi
;
1271 for (psi
= gsi_start_phis (bb
); !gsi_end_p (psi
); gsi_next (&psi
))
1273 gimple_stmt_iterator gsi
= psi
;
1274 gimple phi
= gsi_stmt (psi
);
1276 /* At this point, PHI should be a close phi in normal form. */
1277 gcc_assert (gimple_phi_num_args (phi
) == 1);
1279 /* Iterate over the next phis and remove duplicates. */
1281 while (!gsi_end_p (gsi
))
1282 if (same_close_phi_node (phi
, gsi_stmt (gsi
)))
1283 remove_duplicate_close_phi (phi
, &gsi
);
1289 /* Transforms LOOP to the canonical loop closed SSA form. */
1292 canonicalize_loop_closed_ssa (loop_p loop
)
1294 edge e
= single_exit (loop
);
1297 if (!e
|| e
->flags
& EDGE_ABNORMAL
)
1302 if (VEC_length (edge
, bb
->preds
) == 1)
1304 e
= split_block_after_labels (bb
);
1305 make_close_phi_nodes_unique (e
->src
);
1309 gimple_stmt_iterator psi
;
1310 basic_block close
= split_edge (e
);
1312 e
= single_succ_edge (close
);
1314 for (psi
= gsi_start_phis (bb
); !gsi_end_p (psi
); gsi_next (&psi
))
1316 gimple phi
= gsi_stmt (psi
);
1319 for (i
= 0; i
< gimple_phi_num_args (phi
); i
++)
1320 if (gimple_phi_arg_edge (phi
, i
) == e
)
1322 tree res
, arg
= gimple_phi_arg_def (phi
, i
);
1323 use_operand_p use_p
;
1326 if (TREE_CODE (arg
) != SSA_NAME
)
1329 close_phi
= create_phi_node (NULL_TREE
, close
);
1330 res
= create_new_def_for (arg
, close_phi
,
1331 gimple_phi_result_ptr (close_phi
));
1332 add_phi_arg (close_phi
, arg
,
1333 gimple_phi_arg_edge (close_phi
, 0),
1335 use_p
= gimple_phi_arg_imm_use_ptr (phi
, i
);
1336 replace_exp (use_p
, res
);
1341 make_close_phi_nodes_unique (close
);
1344 /* The code above does not properly handle changes in the post dominance
1345 information (yet). */
1346 free_dominance_info (CDI_POST_DOMINATORS
);
1349 /* Converts the current loop closed SSA form to a canonical form
1350 expected by the Graphite code generation.
1352 The loop closed SSA form has the following invariant: a variable
1353 defined in a loop that is used outside the loop appears only in the
1354 phi nodes in the destination of the loop exit. These phi nodes are
1355 called close phi nodes.
1357 The canonical loop closed SSA form contains the extra invariants:
1359 - when the loop contains only one exit, the close phi nodes contain
1360 only one argument. That implies that the basic block that contains
1361 the close phi nodes has only one predecessor, that is a basic block
1364 - the basic block containing the close phi nodes does not contain
1367 - there exist only one phi node per definition in the loop.
1371 canonicalize_loop_closed_ssa_form (void)
1376 #ifdef ENABLE_CHECKING
1377 verify_loop_closed_ssa (true);
1380 FOR_EACH_LOOP (li
, loop
, 0)
1381 canonicalize_loop_closed_ssa (loop
);
1383 rewrite_into_loop_closed_ssa (NULL
, TODO_update_ssa
);
1384 update_ssa (TODO_update_ssa
);
1386 #ifdef ENABLE_CHECKING
1387 verify_loop_closed_ssa (true);
1391 /* Find Static Control Parts (SCoP) in the current function and pushes
1395 build_scops (VEC (scop_p
, heap
) **scops
)
1397 struct loop
*loop
= current_loops
->tree_root
;
1398 VEC (sd_region
, heap
) *regions
= VEC_alloc (sd_region
, heap
, 3);
1400 canonicalize_loop_closed_ssa_form ();
1401 build_scops_1 (single_succ (ENTRY_BLOCK_PTR
), ENTRY_BLOCK_PTR
->loop_father
,
1403 create_sese_edges (regions
);
1404 build_graphite_scops (regions
, scops
);
1406 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1407 print_graphite_statistics (dump_file
, *scops
);
1409 limit_scops (scops
);
1410 VEC_free (sd_region
, heap
, regions
);
1412 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1413 fprintf (dump_file
, "\nnumber of SCoPs: %d\n",
1414 VEC_length (scop_p
, *scops
));
1417 /* Pretty print to FILE all the SCoPs in DOT format and mark them with
1418 different colors. If there are not enough colors, paint the
1419 remaining SCoPs in gray.
1422 - "*" after the node number denotes the entry of a SCoP,
1423 - "#" after the node number denotes the exit of a SCoP,
1424 - "()" around the node number denotes the entry or the
1425 exit nodes of the SCOP. These are not part of SCoP. */
1428 dot_all_scops_1 (FILE *file
, VEC (scop_p
, heap
) *scops
)
1437 /* Disable debugging while printing graph. */
1438 int tmp_dump_flags
= dump_flags
;
1441 fprintf (file
, "digraph all {\n");
1445 int part_of_scop
= false;
1447 /* Use HTML for every bb label. So we are able to print bbs
1448 which are part of two different SCoPs, with two different
1449 background colors. */
1450 fprintf (file
, "%d [label=<\n <TABLE BORDER=\"0\" CELLBORDER=\"1\" ",
1452 fprintf (file
, "CELLSPACING=\"0\">\n");
1454 /* Select color for SCoP. */
1455 FOR_EACH_VEC_ELT (scop_p
, scops
, i
, scop
)
1457 sese region
= SCOP_REGION (scop
);
1458 if (bb_in_sese_p (bb
, region
)
1459 || (SESE_EXIT_BB (region
) == bb
)
1460 || (SESE_ENTRY_BB (region
) == bb
))
1473 case 3: /* purple */
1476 case 4: /* orange */
1479 case 5: /* yellow */
1519 fprintf (file
, " <TR><TD WIDTH=\"50\" BGCOLOR=\"%s\">", color
);
1521 if (!bb_in_sese_p (bb
, region
))
1522 fprintf (file
, " (");
1524 if (bb
== SESE_ENTRY_BB (region
)
1525 && bb
== SESE_EXIT_BB (region
))
1526 fprintf (file
, " %d*# ", bb
->index
);
1527 else if (bb
== SESE_ENTRY_BB (region
))
1528 fprintf (file
, " %d* ", bb
->index
);
1529 else if (bb
== SESE_EXIT_BB (region
))
1530 fprintf (file
, " %d# ", bb
->index
);
1532 fprintf (file
, " %d ", bb
->index
);
1534 if (!bb_in_sese_p (bb
,region
))
1535 fprintf (file
, ")");
1537 fprintf (file
, "</TD></TR>\n");
1538 part_of_scop
= true;
1544 fprintf (file
, " <TR><TD WIDTH=\"50\" BGCOLOR=\"#ffffff\">");
1545 fprintf (file
, " %d </TD></TR>\n", bb
->index
);
1547 fprintf (file
, " </TABLE>>, shape=box, style=\"setlinewidth(0)\"]\n");
1552 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
1553 fprintf (file
, "%d -> %d;\n", bb
->index
, e
->dest
->index
);
1556 fputs ("}\n\n", file
);
1558 /* Enable debugging again. */
1559 dump_flags
= tmp_dump_flags
;
1562 /* Display all SCoPs using dotty. */
1565 dot_all_scops (VEC (scop_p
, heap
) *scops
)
1567 /* When debugging, enable the following code. This cannot be used
1568 in production compilers because it calls "system". */
1571 FILE *stream
= fopen ("/tmp/allscops.dot", "w");
1572 gcc_assert (stream
);
1574 dot_all_scops_1 (stream
, scops
);
1577 x
= system ("dotty /tmp/allscops.dot &");
1579 dot_all_scops_1 (stderr
, scops
);
1583 /* Display all SCoPs using dotty. */
1586 dot_scop (scop_p scop
)
1588 VEC (scop_p
, heap
) *scops
= NULL
;
1591 VEC_safe_push (scop_p
, heap
, scops
, scop
);
1593 /* When debugging, enable the following code. This cannot be used
1594 in production compilers because it calls "system". */
1598 FILE *stream
= fopen ("/tmp/allscops.dot", "w");
1599 gcc_assert (stream
);
1601 dot_all_scops_1 (stream
, scops
);
1603 x
= system ("dotty /tmp/allscops.dot &");
1606 dot_all_scops_1 (stderr
, scops
);
1609 VEC_free (scop_p
, heap
, scops
);