Before floating point relations were added, we tried to sanitize
value-relation records to not include non-sensensical records... ie x !=
x or x < x. Instead, we made a VREL_VARYING record with no operands.
When floating point relation support was added, some of these were no
longer non-sensical, AND we expanded the use of value_relation records
into GORI shortly thereafter.
As a result, this sanitization is no longer needed, nor desired. The
Oracle does not create records with op1 == op2 already, so its only
within GORI that these records can exist, and we shouldn't try to
interpret them.
The bug occurs because the "sanitized" records doesn't set op1 and op2,
and changes the relation to VARYING.. and we expected the operands it
to be set the way they were specified. We should not be setting a
VREL_VARYING record if asked to set something else. In fact, we are
missing some opportunities because we are trying to FP range-ops that
op1 != op1 but its getting transformed into a VREL_VARYING record and
not communicated properly.
Currently bootstrapping on x86_64-pc-linux-gnu and assuming no
regressions, OK for trunk?
Andrew
commit 1f02961b23976d35b10e2399708c6eb00632f9d6
Author: Andrew MacLeod <amacl...@redhat.com>
Date: Fri Mar 24 09:18:33 2023 -0400
Don't interpret contents of a value_relation record.
before floating point relations were added, we tried to sanitize
value-relation records to not include non-sensensical records... ie
x != x or x < x. INstead, we made a VREL_VARYING record with no
operands.
When floating point relations were supported, some of these were no
longer non-sensical, AND we expanded the use of value_relation records
into GORI.
As a result, this sanitization is no longer needed. The Oracle
does not create records with op1 == op2, so its only within GORI
that these records can exist, and we shouldnt try to interpret them.
The bug occurs because the "sanitized" records doesnt set op1 anmd op2,
but we have a record so expected it to be set.
PR tree-optimization/109265
PR tree-optimization/109274
gcc/
* value-relation.h (value_relation::set_relation): Always create the
record that is requested.
gcc/testsuite/
* gcc.dg/pr109274.c: New.
diff --git a/gcc/testsuite/gcc.dg/pr109274.c b/gcc/testsuite/gcc.dg/pr109274.c
new file mode 100644
index 00000000000..5dbc0232f8e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr109274.c
@@ -0,0 +1,16 @@
+/* PR tree-optimization/109274 */
+/* { dg-do compile } */
+/* { dg-options "-O2 " } */
+
+float a, b, c;
+int d;
+float bar (void);
+
+void
+foo (void)
+{
+ a = 0 * -(2.0f * c);
+ d = a != a ? 0 : bar ();
+ b = c;
+}
+
diff --git a/gcc/value-relation.h b/gcc/value-relation.h
index 36a75862cc7..3177ecb1ad0 100644
--- a/gcc/value-relation.h
+++ b/gcc/value-relation.h
@@ -445,13 +445,6 @@ value_relation::set_relation (relation_kind r, tree n1, tree n2)
{
gcc_checking_assert (TREE_CODE (n1) == SSA_NAME
&& TREE_CODE (n2) == SSA_NAME);
- if (n1 == n2 && r != VREL_EQ)
- {
- related = VREL_VARYING;
- name1 = NULL_TREE;
- name2 = NULL_TREE;
- return;
- }
related = r;
name1 = n1;
name2 = n2;
