1 files changed, 50 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/pr20126.c b/gcc/testsuite/gcc.dg/pr20126.c
new file mode 100644
index 000000000..257832ab1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr20126.c
@@ -0,0 +1,50 @@
+/* dg-do run */
+/* dg-options "-O2" */
+
+/* PR target/20126 was not really target-specific, but rather a loop's
+   failure to take into account the possibility that a DEST_ADDR giv
+   replacement might fail, such as when you attempt to replace a REG
+   with a PLUS in one of the register_operands of cmpstrqi_rex_1.  */
+
+extern void abort (void);
+
+typedef struct { int a; char b[3]; } S;
+S c = { 2, "aa" }, d = { 2, "aa" };
+
+void *
+bar (const void *x, int y, int z)
+{
+  return (void *) 0;
+}
+
+int
+foo (S *x, S *y)
+{
+  const char *e, *f, *g;
+  int h;
+
+  h = y->a;
+  f = y->b;
+  e = x->b;
+
+  if (h == 1)
+    return bar (e, *f, x->a) != 0;
+
+  g = e + x->a - h;
+  while (e <= g)
+    {
+      const char *t = e + 1;
+      if (__builtin_memcmp (e, f, h) == 0)
+        return 1;
+      e = t;
+    }
+  return 0;
+}
+
+int
+main (void)
+{
+  if (foo (&c, &d) != 1)
+    abort ();
+  return 0;
+}