For basic block with two preds, allow (as single entry) only when the other
edge is a backedge. Similarly for basic block with two succs,
allow (as single exit) only when the other edge is a back edge.
2015-12-21 Aditya Kumar <hiradi...@msn.com>
* graphite-scop-detection.c
(scop_detection::get_nearest_dom_with_single_entry): Check l == l2.
(scop_detection::get_nearest_pdom_with_single_exit): Same.
(scop_detection::merge_sese): Whitespace.
(scop_detection::add_scop): Comment.
(build_scops): Whitespace.
---
gcc/graphite-scop-detection.c | 31 +++++++++++++++++++++----------
1 file changed, 21 insertions(+), 10 deletions(-)
diff --git a/gcc/graphite-scop-detection.c b/gcc/graphite-scop-detection.c
index dd506b5..ad11227 100644
--- a/gcc/graphite-scop-detection.c
+++ b/gcc/graphite-scop-detection.c
@@ -693,18 +693,22 @@ scop_detection::get_nearest_dom_with_single_entry
(basic_block dom)
{
if (!dom->preds)
return NULL;
- /* If e1->src dominates e2->src then e1->src will also dominate dom. */
+
+ /* If any of the dominators has two predecessors but one of them is a back
+ edge, then that basic block also qualifies as a dominator with single
+ entry. */
if (dom->preds->length () == 2)
{
+ /* If e1->src dominates e2->src then e1->src will also dominate dom. */
edge e1 = (*dom->preds)[0];
edge e2 = (*dom->preds)[1];
loop_p l = dom->loop_father;
loop_p l1 = e1->src->loop_father;
loop_p l2 = e2->src->loop_father;
- if (l != l1
+ if (l != l1 && l == l2
&& dominated_by_p (CDI_DOMINATORS, e2->src, e1->src))
return e1;
- if (l != l2
+ if (l != l2 && l == l1
&& dominated_by_p (CDI_DOMINATORS, e1->src, e2->src))
return e2;
}
@@ -728,17 +732,23 @@ scop_detection::get_nearest_pdom_with_single_exit
(basic_block pdom)
{
if (!pdom->succs)
return NULL;
+
+ /* If any of the post-dominators has two successors but one of them is a back
+ edge, then that basic block also qualifies as a post-dominator with single
+ exit. */
if (pdom->succs->length () == 2)
{
+ /* If e1->dest post-dominates e2->dest then e1->dest will also
+ post-dominate pdom. */
edge e1 = (*pdom->succs)[0];
edge e2 = (*pdom->succs)[1];
loop_p l = pdom->loop_father;
loop_p l1 = e1->dest->loop_father;
loop_p l2 = e2->dest->loop_father;
- if (l != l1
+ if (l != l1 && l == l2
&& dominated_by_p (CDI_POST_DOMINATORS, e2->dest, e1->dest))
return e1;
- if (l != l2
+ if (l != l2 && l == l1
&& dominated_by_p (CDI_POST_DOMINATORS, e1->dest, e2->dest))
return e2;
}
@@ -805,7 +815,7 @@ scop_detection::merge_sese (sese_l first, sese_l second)
const
EXIT->DEST should be in the same loop nest. */
if (!dominated_by_p (CDI_DOMINATORS, pdom, dom)
|| loop_depth (entry->src->loop_father)
- != loop_depth (exit->dest->loop_father))
+ != loop_depth (exit->dest->loop_father))
return invalid_sese;
/* For now we just want to bail out when exit does not post-dominate entry.
@@ -1014,7 +1024,8 @@ scop_detection::add_scop (sese_l s)
/* Remove all the scops which are subsumed by s. */
remove_subscops (s);
- /* Replace this with split-intersecting scops. */
+ /* Remove intersecting scops. FIXME: It will be a good idea to keep
+ the non-intersecting part of the scop already in the list. */
remove_intersecting_scops (s);
scops.safe_push (s);
@@ -1960,9 +1971,9 @@ build_scops (vec<scop_p> *scops)
if (scop_nb_params (scop) > max_dim)
{
DEBUG_PRINT (dp << "[scop-detection-fail] too many parameters: "
- << scop_nb_params (scop)
- << " larger than --param graphite-max-nb-scop-params="
- << max_dim << ".\n");
+ << scop_nb_params (scop)
+ << " larger than --param graphite-max-nb-scop-params="
+ << max_dim << ".\n");
free_scop (scop);
continue;
}
--
2.6.3
