When we decompose a complex load only used as real and imaginary
parts we fail to honor IL constraints which are that a BIT_FIELD_REF
of register type should be outermost in a ref. The following
simply avoids the transform when the complex load has such a
BIT_FIELD_REF.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
PR tree-optimization/117417
* tree-ssa-forwprop.cc (pass_forwprop::execute): Avoid
decomposing BIT_FIELD_REF complex load.
* gcc.dg/torture/pr117417.c: New testcase.
---
gcc/testsuite/gcc.dg/torture/pr117417.c | 16 ++++++++++++++++
gcc/tree-ssa-forwprop.cc | 4 ++--
2 files changed, 18 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/torture/pr117417.c
diff --git a/gcc/testsuite/gcc.dg/torture/pr117417.c
b/gcc/testsuite/gcc.dg/torture/pr117417.c
new file mode 100644
index 00000000000..2c80dd5d77c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr117417.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+
+typedef __attribute__((__vector_size__ (8))) double V;
+int bar (int a, V *p)
+{
+ V v;
+ v = *p;
+ a += *(_Complex short *) &v;
+ return a;
+}
+V x;
+int
+foo ()
+{
+ return bar (0, &x);
+}
diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc
index cb1e86c6912..5c690a2b03e 100644
--- a/gcc/tree-ssa-forwprop.cc
+++ b/gcc/tree-ssa-forwprop.cc
@@ -3687,8 +3687,8 @@ pass_forwprop::execute (function *fun)
else if (TREE_CODE (TREE_TYPE (lhs)) == COMPLEX_TYPE
&& gimple_assign_load_p (stmt)
&& !gimple_has_volatile_ops (stmt)
- && (TREE_CODE (gimple_assign_rhs1 (stmt))
- != TARGET_MEM_REF)
+ && TREE_CODE (rhs) != TARGET_MEM_REF
+ && TREE_CODE (rhs) != BIT_FIELD_REF
&& !stmt_can_throw_internal (fun, stmt))
{
/* Rewrite loads used only in real/imagpart extractions to
--
2.43.0
