[gcc r16-3380] Add a test for PR tree-optimization/121656

[H.J. Lu via Gcc-cvs]

https://gcc.gnu.org/g:1b6b27536311afefaebf57ff77ed20a8bb41eadd

commit r16-3380-g1b6b27536311afefaebf57ff77ed20a8bb41eadd
Author: H.J. Lu <hjl.to...@gmail.com>
Date:   Mon Aug 25 08:20:00 2025 -0700

    Add a test for PR tree-optimization/121656
    
            PR tree-optimization/121656
            * gcc.dg/pr121656.c: New file.
    
    Signed-off-by: H.J. Lu <hjl.to...@gmail.com>

Diff:
---
 gcc/testsuite/gcc.dg/pr121656.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/gcc/testsuite/gcc.dg/pr121656.c b/gcc/testsuite/gcc.dg/pr121656.c
new file mode 100644
index 000000000000..00b89418a319
--- /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;
+}