1 files changed, 39 insertions, 0 deletions
diff --git a/gcc-4.9/gcc/testsuite/gcc.dg/ext-elim-1.c b/gcc-4.9/gcc/testsuite/gcc.dg/ext-elim-1.c
new file mode 100644
index 000000000..5e899a235
--- /dev/null
+++ b/gcc-4.9/gcc/testsuite/gcc.dg/ext-elim-1.c
@@ -0,0 +1,39 @@
+/* PR rtl-optimization/51924 */
+/* Testcase by Zdenek Sojka <zsojka@seznam.cz> */
+
+/* { dg-do run } */
+/* { dg-options "-O -free -fno-rename-registers -ftree-vectorize -funroll-loops" } */
+
+typedef __UINT64_TYPE__ uint64_t;
+
+uint64_t __attribute__ ((noinline, noclone))
+bn_sub_words (uint64_t * r, const uint64_t * a, const uint64_t * b, int n)
+{
+  uint64_t t1, t2;
+  unsigned c = 0;
+
+  while (n)
+    {
+      t1 = a[0];
+      t2 = b[0];
+      r[0] = (t1 - t2 - c);
+      if (t1 != t2)
+	c = (t1 < t2);
+      a++;
+      b++;
+      r++;
+      n--;
+    }
+  return (c);
+}
+
+int
+main (void)
+{
+  uint64_t r[2];
+  uint64_t a[2] = { -1, -1 };
+  uint64_t b[2] = { 0, 0 };
+  if (bn_sub_words (r, a, b, 2) != 0)
+    __builtin_abort ();
+  return 0;
+}