--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/c-c++-common/asan/no-redundant-instrumentation-1.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,59 @@
+/* This tests that when faced with two references to the same memory
+   location in the same basic block, the second reference should not
+   be instrumented by the Address Sanitizer.  */
+
+/* { dg-options "-fdump-tree-sanopt" } */
+/* { dg-do compile } */
+/* { dg-skip-if "" { *-*-* } { "*" } { "-O0" } } */
+
+extern char tab[6];
+
+static int
+test0 ()
+{
+  /* __builtin___asan_report_store1 called 2 times for the two stores
+     below.  */
+  tab[0] = 1;
+  tab[1] = 2;
+
+  /* This load should not be instrumented because it is to the same
+     memory location as above.  */
+  char t0 = tab[1];
+
+  /* Likewise.  */
+  char t1 = tab[1];
+
+  return t0 + t1;
+}
+
+__attribute__((noinline, noclone)) static int
+test1 (int i)
+{
+  char foo[4] = {};
+  
+  /*__builtin___asan_report_store1 called 1 time here to instrument
+    the initialization.  */
+  foo[i] = 1;
+
+  /* Instrument tab memory region.  */
+  __builtin_memset (tab, 3, sizeof (tab));
+
+  /* Instrument tab[1] with access size 3.  */
+  __builtin_memcpy (&tab[1], foo + i, 3);
+
+  /* This should not generate a __builtin___asan_report_load1 because
+     the reference to tab[1] has been already instrumented above.  */
+  return tab[1];
+
+  /* So for these functions, there should be 3 calls to
+     __builtin___asan_report_store1.  */
+}
+
+int
+main ()
+{
+  return test0 () && test1 (0);
+}
+
+/* { dg-final { scan-tree-dump-times "__builtin___asan_report_store1" 3 "sanopt" } } */
+/* { dg-final { scan-tree-dump-not "__builtin___asan_report_load1" "sanopt" } } */