1 files changed, 48 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/20100906-1.c b/gcc/testsuite/gcc.dg/20100906-1.c
new file mode 100644
index 000000000..a6541e3ff
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/20100906-1.c
@@ -0,0 +1,48 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+/* This testcase got misoptimized by combine due to a wrong setting of
+   subst_low_luid in try_combine.  */
+
+enum rtx_code {
+  A, B
+};
+
+void abort (void);
+
+struct rtx_def {
+  __extension__ enum rtx_code code:16;
+};
+typedef struct rtx_def *rtx;
+
+void __attribute__((noinline))
+add_constraint (unsigned char is_a)
+{
+  if (is_a)
+    abort ();
+}
+
+void __attribute__((noinline))
+foo (rtx defn)
+{
+  switch (defn->code)
+    {
+    case A:
+    case B:
+      add_constraint (defn->code == A);
+      break;
+    default:
+      break;
+    }
+}
+
+int
+main ()
+{
+  struct rtx_def r;
+
+  r.code = B;
+
+  foo (&r);
+  return 0;
+}