* [PATCH] PR tree-optimization/105458 - Check for equivalence after merging relations.
@ 2022-05-17 15:45 Andrew MacLeod
2022-05-18 5:57 ` Richard Biener
0 siblings, 1 reply; 2+ messages in thread
From: Andrew MacLeod @ 2022-05-17 15:45 UTC (permalink / raw)
To: gcc-patches
[-- Attachment #1: Type: text/plain, Size: 823 bytes --]
Sorry, missed this one earlier.
When we register a relation, such as LE_EXPR, we first check if there
is an existing relation that applies, and if so they are combined. We
were checking if the relation being registered was an EQ_EXPR, and if
so, invoked the equivalence oracle.
I was doing the check for EQ_EXPR first, then merging with any
existing relation. In this case, the merge resulted in transforming
the LE_EXPR into an EQ_EXPR, but the check to invoke the
equivalence_oracle had already been done, and we got to a place we
shouldn't have. doh!
The fix is to do the merge first, then check for EQ_EXPR.
The patch is a hair different (due to VREL_* renames in gcc13), so I've
attached both patches.
bootstraps on gcc12 and gcc13 with no regressions. pushed on trunk.
OK for GCC12?
Andrew
[-- Attachment #2: pr105458.patch --]
[-- Type: text/x-patch, Size: 2014 bytes --]
commit 84c0e801f26275a4700c10a710a185c17f0418e5
Author: Andrew MacLeod <amacleod@redhat.com>
Date: Mon May 16 21:39:30 2022 -0400
Check for equivalence after merging relations.
When registering a relation, we need to merge with any existing relation
before checking if it was an equivalence... otherwise it was not being
handled properly.
gcc/
PR tree-optimization/105458
* value-relation.cc (path_oracle::register_relation): Merge, then check
for equivalence.
gcc/testsuite/
* gcc.dg/pr105458.c: New.
diff --git a/gcc/testsuite/gcc.dg/pr105458.c b/gcc/testsuite/gcc.dg/pr105458.c
new file mode 100644
index 00000000000..eb58bf21f32
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr105458.c
@@ -0,0 +1,20 @@
+/* PR tree-optimization/105458 */
+/* { dg-do compile } */
+/* { dg-options "-O1 -fexpensive-optimizations -fno-tree-dominator-opts " } */
+
+void
+yj (int j4)
+{
+ int t3;
+
+ for (t3 = 0; t3 < 6; ++t3)
+ {
+ short int v4 = t3;
+
+ if (v4 == j4 || v4 > t3)
+ for (;;)
+ {
+ }
+ }
+}
+
diff --git a/gcc/value-relation.cc b/gcc/value-relation.cc
index a93565109f9..85d159f5d96 100644
--- a/gcc/value-relation.cc
+++ b/gcc/value-relation.cc
@@ -1384,16 +1384,16 @@ path_oracle::register_relation (basic_block bb, relation_kind k, tree ssa1,
fprintf (dump_file, " (root: bb%d)\n", bb->index);
}
+ relation_kind curr = query_relation (bb, ssa1, ssa2);
+ if (curr != VREL_VARYING)
+ k = relation_intersect (curr, k);
+
if (k == VREL_EQ)
{
register_equiv (bb, ssa1, ssa2);
return;
}
- relation_kind curr = query_relation (bb, ssa1, ssa2);
- if (curr != VREL_VARYING)
- k = relation_intersect (curr, k);
-
bitmap_set_bit (m_relations.m_names, SSA_NAME_VERSION (ssa1));
bitmap_set_bit (m_relations.m_names, SSA_NAME_VERSION (ssa2));
relation_chain *ptr = (relation_chain *) obstack_alloc (&m_chain_obstack,
[-- Attachment #3: gcc12-pr105458.patch --]
[-- Type: text/x-patch, Size: 2008 bytes --]
commit c48fe8d3430e81ddea621c24e9b66d55aadfb316
Author: Andrew MacLeod <amacleod@redhat.com>
Date: Tue May 17 09:36:39 2022 -0400
Check for equivalence after merging relations.
When registering a relation, we need to merge with any existing relation
before checking if it was an equivalence... otherwise it was not being
handled properly.
gcc/
PR tree-optimization/105458
* value-relation.cc (path_oracle::register_relation): Merge, then check
for equivalence.
gcc/testsuite/
* gcc.dg/pr105458.c: New.
diff --git a/gcc/testsuite/gcc.dg/pr105458.c b/gcc/testsuite/gcc.dg/pr105458.c
new file mode 100644
index 00000000000..eb58bf21f32
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr105458.c
@@ -0,0 +1,20 @@
+/* PR tree-optimization/105458 */
+/* { dg-do compile } */
+/* { dg-options "-O1 -fexpensive-optimizations -fno-tree-dominator-opts " } */
+
+void
+yj (int j4)
+{
+ int t3;
+
+ for (t3 = 0; t3 < 6; ++t3)
+ {
+ short int v4 = t3;
+
+ if (v4 == j4 || v4 > t3)
+ for (;;)
+ {
+ }
+ }
+}
+
diff --git a/gcc/value-relation.cc b/gcc/value-relation.cc
index 077ab4230a7..a69ad080e47 100644
--- a/gcc/value-relation.cc
+++ b/gcc/value-relation.cc
@@ -1388,16 +1388,16 @@ path_oracle::register_relation (basic_block bb, relation_kind k, tree ssa1,
fprintf (dump_file, " (root: bb%d)\n", bb->index);
}
+ relation_kind curr = query_relation (bb, ssa1, ssa2);
+ if (curr != VREL_NONE)
+ k = relation_intersect (curr, k);
+
if (k == EQ_EXPR)
{
register_equiv (bb, ssa1, ssa2);
return;
}
- relation_kind curr = query_relation (bb, ssa1, ssa2);
- if (curr != VREL_NONE)
- k = relation_intersect (curr, k);
-
bitmap_set_bit (m_relations.m_names, SSA_NAME_VERSION (ssa1));
bitmap_set_bit (m_relations.m_names, SSA_NAME_VERSION (ssa2));
relation_chain *ptr = (relation_chain *) obstack_alloc (&m_chain_obstack,
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] PR tree-optimization/105458 - Check for equivalence after merging relations.
2022-05-17 15:45 [PATCH] PR tree-optimization/105458 - Check for equivalence after merging relations Andrew MacLeod
@ 2022-05-18 5:57 ` Richard Biener
0 siblings, 0 replies; 2+ messages in thread
From: Richard Biener @ 2022-05-18 5:57 UTC (permalink / raw)
To: Andrew MacLeod; +Cc: gcc-patches
On Tue, May 17, 2022 at 5:46 PM Andrew MacLeod via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> Sorry, missed this one earlier.
>
> When we register a relation, such as LE_EXPR, we first check if there
> is an existing relation that applies, and if so they are combined. We
> were checking if the relation being registered was an EQ_EXPR, and if
> so, invoked the equivalence oracle.
>
> I was doing the check for EQ_EXPR first, then merging with any
> existing relation. In this case, the merge resulted in transforming
> the LE_EXPR into an EQ_EXPR, but the check to invoke the
> equivalence_oracle had already been done, and we got to a place we
> shouldn't have. doh!
>
> The fix is to do the merge first, then check for EQ_EXPR.
>
> The patch is a hair different (due to VREL_* renames in gcc13), so I've
> attached both patches.
>
> bootstraps on gcc12 and gcc13 with no regressions. pushed on trunk.
>
> OK for GCC12?
OK
> Andrew
^ permalink raw reply [flat|nested] 2+ messages in thread
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