--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/pr81281-2.c	Thu Oct 25 07:37:49 2018 +0900
@@ -0,0 +1,80 @@
+/* PR sanitizer/81281 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+/* { dg-final { scan-tree-dump-not "p_\[0-9]*\\(D\\)" "optimized" } } */
+
+typedef __SIZE_TYPE__ size_t;
+typedef __INTPTR_TYPE__ T;
+
+T
+f1 (char *p, size_t a, size_t b)
+{
+  char *c = p + 1;
+  size_t d = a + 2;
+  size_t e = b + 3;
+  T f = (T) (p + a);
+  T g = (T) (p + b);
+  return f - g;
+}
+
+T
+f2 (char *p, size_t a, size_t b)
+{
+  size_t c = a + 1;
+  char *d = p + 2;
+  size_t e = b + 3;
+  T f = (T) (p + a);
+  T g = (T) (p + b);
+  return f - g;
+}
+
+T
+f3 (char *p, size_t a, size_t b)
+{
+  size_t c = b + 1;
+  char *d = p + 2;
+  size_t e = a + 3;
+  T f = (T) (p + a);
+  T g = (T) (p + b);
+  return f - g;
+}
+
+T
+f4 (char *p, size_t a)
+{
+  char *c = p + 1;
+  size_t d = a + 2;
+  T f = (T) (p + a);
+  T g = (T) p;
+  return f - g;
+}
+
+T
+f5 (char *p, size_t a)
+{
+  size_t c = a + 1;
+  char *d = p + 2;
+  T f = (T) (p + a);
+  T g = (T) p;
+  return f - g;
+}
+
+T
+f6 (char *p, size_t a)
+{
+  char *c = p + 1;
+  size_t d = a + 2;
+  T f = (T) p;
+  T g = (T) (p + a);
+  return f - g;
+}
+
+T
+f7 (char *p, size_t a)
+{
+  size_t c = a + 1;
+  char *d = p + 2;
+  T f = (T) p;
+  T g = (T) (p + a);
+  return f - g;
+}