cond_store_replacement_limited mistaken a clobber for a store, meaning
that it would use {CLOBBER(eos)} as a phi argument.
So this fixes that issue by rejecting that case.
Pushed as obvious after bootstrap/test on x86_64-linux-gnu.
PR tree-optimization/126569
gcc/ChangeLog:
* tree-ssa-phiopt.cc (cond_store_replacement_limited): A
clobber is not a store.
gcc/testsuite/ChangeLog:
* gcc.dg/pr126569-1.c: New test.
Signed-off-by: Andrea Pinski <[email protected]>
---
gcc/testsuite/gcc.dg/pr126569-1.c | 20 ++++++++++++++++++++
gcc/tree-ssa-phiopt.cc | 2 ++
2 files changed, 22 insertions(+)
create mode 100644 gcc/testsuite/gcc.dg/pr126569-1.c
diff --git a/gcc/testsuite/gcc.dg/pr126569-1.c
b/gcc/testsuite/gcc.dg/pr126569-1.c
new file mode 100644
index 00000000000..5e2348c2ff1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr126569-1.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fno-tree-dce -fno-tree-dse" } */
+/* PR tree-optimization/126569 */
+
+int wx, qi, gw, ak;
+
+void
+f (void)
+{
+ while (wx)
+ {
+ int k2 = ak;
+ ja:
+ *(int **) &k2 = &gw;
+ while (qi)
+ ++qi;
+ }
+ gw = 1;
+ goto ja;
+}
diff --git a/gcc/tree-ssa-phiopt.cc b/gcc/tree-ssa-phiopt.cc
index 2ff26bfab73..d63a47cc615 100644
--- a/gcc/tree-ssa-phiopt.cc
+++ b/gcc/tree-ssa-phiopt.cc
@@ -3683,6 +3683,8 @@ cond_store_replacement_limited (basic_block middle_bb,
basic_block join_bb,
tree beforelhs = gimple_assign_lhs (vdef_before);
/* Only allow the store to be right before the condition. */
if (gimple_bb (vdef_before) == cond_bb
+ /* This can't be a clobber */
+ && !gimple_clobber_p (vdef_before)
/* An exact match is only supported.
FIXME: Allow for clique/base mismatch? */
&& operand_equal_p (lhs, beforelhs))
--
2.43.0
