1 files changed, 34 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/torture/pr120944.c b/gcc/testsuite/gcc.dg/torture/pr120944.c
new file mode 100644
index 0000000..92f3c77
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr120944.c
@@ -0,0 +1,34 @@
+/* { dg-skip-if "" { *-*-* } { "-flto" } { "" } } */
+/* { dg-additional-options "-fdump-tree-optimized" } */
+
+#include <stdlib.h>
+
+typedef union {
+  int u32;
+  struct
+  {
+     int A:1;
+     int B:2;
+     int C:3;
+  };
+} u_t;
+
+typedef union {
+   volatile int u[3];
+   volatile struct {
+        u_t a;
+        int b;
+        int c;
+   };
+} DATA;
+
+void foo (volatile DATA *d)
+{
+     d->a.u32 = ~0;
+     u_t u = d->a;
+     int v = u.A;
+     if (v)
+        abort();
+}
+
+/* { dg-final { scan-tree-dump-times "if \\\(" 1 "optimized" } } */