Index: test/asan/TestCases/masked-ops.cpp
===================================================================
--- /dev/null
+++ test/asan/TestCases/masked-ops.cpp
@@ -0,0 +1,102 @@
+// We need optimization to convert target-specific masked loads/stores to llvm
+// generic loads/stores
+// RUN: %clangxx_asan -o %t %s -mavx -O1
+// RUN: not %run %t l1 2>&1 | FileCheck -check-prefix=CHECK-L1 %s
+// RUN: %run %t l6 | FileCheck -check-prefix=CHECK-L6 %s
+// RUN: %run %t la | FileCheck -check-prefix=CHECK-LA %s
+// RUN: not %run %t s1 2>&1 | FileCheck -check-prefix=CHECK-S1 %s
+// RUN: %run %t s6 | FileCheck -check-prefix=CHECK-S6 %s
+// RUN: %run %t sa | FileCheck -check-prefix=CHECK-SA %s
+// REQUIRES: x86-target-arch
+#include <assert.h>
+#include <stdio.h>
+#include <x86intrin.h>
+
+float g_vec3[3] = {1802398064.0, 1881171305.0, 25961.0};
+
+void maskedstore_ps_0110(__m128 a) {
+  _mm_maskstore_ps(g_vec3, (__v4si){0, -1, -1, 0}, a);
+}
+
+void maskedstore_ps_0001(__m128 a) {
+  _mm_maskstore_ps(g_vec3, (__v4si){0, 0, 0, -1}, a);
+}
+
+void maskedstore_ps_1010(__m128 a) {
+  _mm_maskstore_ps(g_vec3, (__v4si){-1, 0, -1, 0}, a);
+}
+
+__m128i maskedload_ps_0110() {
+  return _mm_maskload_ps(g_vec3, (__v4si){0, -1, -1, 0});
+}
+
+__m128i maskedload_ps_0001() {
+  return _mm_maskload_ps(g_vec3, (__v4si){0, 0, 0, -1});
+}
+
+__m128i maskedload_ps_1010() {
+  return _mm_maskload_ps(g_vec3, (__v4si){-1, 0, -1, 0});
+}
+
+__m128 a = (__v4sf){1.0, 2.0, 3.0, 4.0};
+
+void print_vector(__v4sf v) {
+  printf("%d,%d,%d,%d\n", (int)v[0], (int)v[1], (int)v[2], (int)v[3]);
+}
+void print_vector3(float * v) {
+  printf("%d,%d,%d\n", (int)v[0], (int)v[1], (int)v[2]);
+}
+
+int main(int argc, char **argv) {
+  assert(argc > 1);
+  bool isLoad = argv[1][0] == 'l';
+  assert(isLoad || argv[1][0] == 's');
+  if (isLoad) {
+    switch (argv[1][1]) {
+    case '1': {
+      // CHECK-L1: ERROR: AddressSanitizer
+      __v4sf v = maskedload_ps_0001();
+      print_vector(v);
+      // Should have blown up
+      break;
+    }
+    case '6': {
+      // Safe
+      __v4sf v = maskedload_ps_0110();
+      // CHECK-L6: 0,1881171328,25961,0
+      print_vector(v);
+      return 0;
+    }
+    case 'a': {
+      // TODO: Poison middle element
+      // Safe
+      __v4sf v = maskedload_ps_1010();
+      // CHECK-LA: 1802398080,0,25961,0
+      print_vector(v);
+      return 0;
+    }
+    }
+  } else {
+    switch (argv[1][1]) {
+    case '1':
+      // CHECK-S1: ERROR: AddressSanitizer
+      maskedstore_ps_0001(a);
+      // Should have blown up
+      break;
+    case '6':
+      // Safe
+      maskedstore_ps_0110(a);
+      // CHECK-S6: 1802398080,2,3
+      print_vector3(g_vec3);
+      return 0;
+    case 'a':
+      // TODO: Poison middle element
+      // Safe
+      maskedstore_ps_1010(a);
+      // CHECK-SA: 1,1881171328,3
+      print_vector3(g_vec3);
+      return 0;
+    }
+  }
+  assert(0);
+}