diff --git a/compiler-rt/test/tsan/bench.h b/compiler-rt/test/tsan/bench.h
--- a/compiler-rt/test/tsan/bench.h
+++ b/compiler-rt/test/tsan/bench.h
@@ -1,18 +1,12 @@
-#include <pthread.h>
-#include <stdlib.h>
-#include <stddef.h>
-#include <unistd.h>
-#include <stdio.h>
+#include "test.h"
 #include <time.h>
 
 int bench_nthread;
 int bench_niter;
-int grow_clock_var;
-pthread_barrier_t glow_clock_barrier;
+int bench_mode;
 
 void bench();  // defined by user
 void start_thread_group(int nth, void(*f)(int tid));
-void grow_clock_worker(int tid);
 
 int main(int argc, char **argv) {
   bench_nthread = 2;
@@ -21,15 +15,8 @@
   bench_niter = 100;
   if (argc > 2)
     bench_niter = atoi(argv[2]);
-
-  // Grow thread's clock.
-  int clock_size = 10;
-  if (argc > 1)
-    clock_size = 1000;
-  pthread_barrier_init(&glow_clock_barrier, 0, clock_size);
-  start_thread_group(clock_size, grow_clock_worker);
-  pthread_barrier_destroy(&glow_clock_barrier);
-  __atomic_load_n(&grow_clock_var, __ATOMIC_ACQUIRE);
+  if (argc > 3)
+    bench_mode = atoi(argv[3]);
 
   timespec tp0;
   clock_gettime(CLOCK_MONOTONIC, &tp0);
@@ -50,10 +37,3 @@
   for (int i = 0; i < nth; i++)
     pthread_join(th[i], 0);
 }
-
-void grow_clock_worker(int tid) {
-  int res = pthread_barrier_wait(&glow_clock_barrier);
-  if (res == PTHREAD_BARRIER_SERIAL_THREAD)
-    __atomic_store_n(&grow_clock_var, 0, __ATOMIC_RELEASE);
-}
-
diff --git a/compiler-rt/test/tsan/bench_memory_access.cpp b/compiler-rt/test/tsan/bench_memory_access.cpp
new file mode 100644
--- /dev/null
+++ b/compiler-rt/test/tsan/bench_memory_access.cpp
@@ -0,0 +1,89 @@
+// RUN: %clangxx_tsan %s -o %t
+// RUN: %run %t 2>&1 | FileCheck %s
+
+// bench.h needs pthread barriers which are not available on OS X
+// UNSUPPORTED: darwin
+
+#include "bench.h"
+#include <memory.h>
+
+void thread(int tid) {
+  volatile long x = 0;
+  switch (bench_mode) {
+  case 0:
+    for (int i = 0; i < bench_niter; i++)
+      *(volatile char *)&x = 1;
+    break;
+  case 1:
+    for (int i = 0; i < bench_niter; i++)
+      *(volatile short *)&x = 1;
+    break;
+  case 2:
+    for (int i = 0; i < bench_niter; i++)
+      *(volatile int *)&x = 1;
+    break;
+  case 3:
+    for (int i = 0; i < bench_niter; i++)
+      *(volatile long *)&x = 1;
+    break;
+  case 4:
+    for (int i = 0; i < bench_niter; i++)
+      *(volatile char *)&x;
+    break;
+  case 5:
+    for (int i = 0; i < bench_niter; i++)
+      *(volatile short *)&x;
+    break;
+  case 6:
+    for (int i = 0; i < bench_niter; i++)
+      *(volatile int *)&x;
+    break;
+  case 7:
+    for (int i = 0; i < bench_niter; i++)
+      *(volatile long *)&x;
+  case 8:
+    for (int i = 0; i < bench_niter / 10; i++) {
+      ((volatile long *)&x)[0];
+      ((volatile int *)&x)[0];
+      ((volatile short *)&x)[2];
+      ((volatile char *)&x)[6];
+      ((volatile char *)&x)[7];
+      ((volatile long *)&x)[0] = 1;
+      ((volatile int *)&x)[0] = 1;
+      ((volatile short *)&x)[2] = 1;
+      ((volatile char *)&x)[6] = 1;
+      ((volatile char *)&x)[7] = 1;
+    }
+    break;
+  case 9: {
+    volatile long size = sizeof(x);
+    for (int i = 0; i < bench_niter; i++)
+      memset((void *)&x, i, size);
+    break;
+  }
+  case 10: {
+    volatile long data[2] = {};
+    volatile long size = sizeof(data) - 2;
+    for (int i = 0; i < bench_niter; i++)
+      memset(((char *)data) + 1, i, size);
+    break;
+  }
+  case 11: {
+    volatile long data[2] = {};
+    for (int i = 0; i < bench_niter / 8 / 3; i++) {
+      for (int off = 0; off < 8; off++) {
+        __sanitizer_unaligned_store16(((char *)data) + off, i);
+        __sanitizer_unaligned_store32(((char *)data) + off, i);
+        __sanitizer_unaligned_store64(((char *)data) + off, i);
+      }
+    }
+    break;
+  }
+  }
+}
+
+void bench() {
+  start_thread_group(bench_nthread, thread);
+}
+
+// CHECK: DONE