1 files changed, 49 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/pr19633.c b/gcc/testsuite/gcc.dg/pr19633.c
new file mode 100644
index 000000000..fda0df6c5
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr19633.c
@@ -0,0 +1,49 @@
+/* { dg-do link } */
+/* { dg-options "-O2" } */
+
+struct S
+{
+  int w, x, y, z;
+};
+
+struct T
+{
+  int r;
+  struct S s;
+};
+
+void
+foo (int a, struct T b)
+{
+  struct S *c = 0;
+
+  if (a)
+    c = &b.s;
+
+  b.s.w = 3;
+
+  /* Since 'c' may be pointing to NULL here, we used to flag it as
+     pointing anywhere, which was forcing the aliaser to mark as
+     call-clobbered every other variable pointed-to by 'c' ('b' in
+     this case).  This, in turn, caused the insertion of V_MAY_DEFs
+     for 'b' at this call-site, which prevented constant propagation
+     from 'b.s.w = 3' to 'if (b.s.w != 3)'.  */
+  bar (*c, a);
+
+  if (b.s.w != 3)
+    link_error ();
+}
+
+int main ()
+{
+  struct T b;
+  foo (3, b);
+  return 0;
+}
+
+int X;
+
+int bar (struct S x, int i)
+{
+  X = 3;
+}