[PATCH] Add a test for PR tree-optimization/121656

[H.J. Lu]

        PR tree-optimization/121656
        * gcc.dg/pr121656.c: New file.

Signed-off-by: H.J. Lu <hjl.to...@gmail.com>
---
 gcc/testsuite/gcc.dg/pr121656.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/pr121656.c

diff --git a/gcc/testsuite/gcc.dg/pr121656.c b/gcc/testsuite/gcc.dg/pr121656.c
new file mode 100644
index 00000000000..00b89418a31
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr121656.c
@@ -0,0 +1,21 @@
+/* { dg-do run } */
+/* { dg-options "-O1" } */
+
+__attribute__ ((weak))
+void
+foo (int b)
+{
+  if (b != 3)
+    __builtin_abort ();
+}
+
+int a;
+int
+main ()
+{
+  int b = 0;
+  if (a >= 0)
+    b += 3;
+  foo (b);
+  return 0;
+}
-- 
2.51.0