When forwprop decomposes a vector load based on BIT_FIELD_REF
uses we have to avoid moving defs of abnormals.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
PR tree-optimization/125502
* tree-ssa-forwprop.cc (optimize_vector_load): Do not
move defs of abnormals.
* gcc.dg/torture/pr125502.c: New testcase.
---
gcc/testsuite/gcc.dg/torture/pr125502.c | 15 +++++++++++++++
gcc/tree-ssa-forwprop.cc | 8 +++++++-
2 files changed, 22 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/torture/pr125502.c
diff --git a/gcc/testsuite/gcc.dg/torture/pr125502.c
b/gcc/testsuite/gcc.dg/torture/pr125502.c
new file mode 100644
index 00000000000..c31576cae51
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr125502.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+
+int f() __attribute__((returns_twice));
+typedef short v16i16 __attribute__((vector_size(32)));
+void f3(short);
+void f4()
+{
+ v16i16 vec6, vec11;
+ short v13;
+ vec6[0] = f();
+ vec11 = vec6;
+ f3(v13);
+ v13 = vec11[2];
+ f4();
+}
diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc
index 6c94675e0ac..922e36590fd 100644
--- a/gcc/tree-ssa-forwprop.cc
+++ b/gcc/tree-ssa-forwprop.cc
@@ -4425,7 +4425,13 @@ optimize_vector_load (gimple_stmt_iterator *gsi)
gimple *use_stmt = USE_STMT (use_p);
if (is_gimple_debug (use_stmt))
continue;
- if (!is_gimple_assign (use_stmt))
+ tree use_lhs;
+ if (!is_gimple_assign (use_stmt)
+ /* For alias reasons we move the use to the place of the
+ load. Avoid this when abnormals are involved. */
+ || ((TREE_CODE ((use_lhs = gimple_assign_lhs (use_stmt)))
+ == SSA_NAME)
+ && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (use_lhs)))
{
rewrite = false;
break;
--
2.51.0
