diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -199,12 +199,15 @@
 #endif
 
 // Platform-specific options.
-#if SANITIZER_APPLE
-#define PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE 0
-#elif SANITIZER_WINDOWS64
-#define PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE 0
+#if SANITIZER_APPLE || (SANITIZER_WINDOWS && SANITIZER_X64)
+#  define PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE 0
+#  define PLATFORM_MEMCPY_MEMMOVE_CAN_BE_FOLDED 0
+#elif SANITIZER_WINDOWS && SANITIZER_I386
+#  define PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE 1
+#  define PLATFORM_MEMCPY_MEMMOVE_CAN_BE_FOLDED 1
 #else
 #define PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE 1
+#  define PLATFORM_MEMCPY_MEMMOVE_CAN_BE_FOLDED 0
 #endif  // SANITIZER_APPLE
 
 #ifndef COMMON_INTERCEPTOR_INITIALIZE_RANGE
@@ -871,11 +874,19 @@
   // N.B.: If we switch this to internal_ we'll have to use internal_memmove
   // due to memcpy being an alias of memmove on OS X.
   void *ctx;
-#if PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE
-    COMMON_INTERCEPTOR_MEMCPY_IMPL(ctx, dst, src, size);
-#else
-    COMMON_INTERCEPTOR_MEMMOVE_IMPL(ctx, dst, src, size);
-#endif
+#  ifndef PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE
+#    error "Undefined"
+#  endif
+
+#  ifndef PLATFORM_MEMCPY_MEMMOVE_CAN_BE_FOLDED
+#    error "Undefined"
+#  endif
+#  if PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE && \
+      !PLATFORM_MEMCPY_MEMMOVE_CAN_BE_FOLDED
+  COMMON_INTERCEPTOR_MEMCPY_IMPL(ctx, dst, src, size);
+#  else
+  COMMON_INTERCEPTOR_MEMMOVE_IMPL(ctx, dst, src, size);
+#  endif
 }
 
 #define INIT_MEMCPY                                  \
diff --git a/compiler-rt/test/asan/TestCases/Windows/memcpy_memmove_sanity.cpp b/compiler-rt/test/asan/TestCases/Windows/memcpy_memmove_sanity.cpp
new file mode 100644
--- /dev/null
+++ b/compiler-rt/test/asan/TestCases/Windows/memcpy_memmove_sanity.cpp
@@ -0,0 +1,36 @@
+// RUN: %clang_cl_asan %s -Fe%t.icf.ref /clang:-fno-builtin-memcpy /clang:-fno-builtin-memmove /link /OPT:ICF /OPT:REF
+// RUN: %clang_cl_asan %s -Fe%t.noicf.ref /clang:-fno-builtin-memcpy /clang:-fno-builtin-memmove /link /OPT:NOICF /OPT:REF
+// RUN: %clang_cl_asan %s -Fe%t.icf.noref /clang:-fno-builtin-memcpy /clang:-fno-builtin-memmove /link /OPT:ICF /OPT:NOREF
+// RUN: %clang_cl_asan %s -Fe%t.noicf.noref /clang:-fno-builtin-memcpy /clang:-fno-builtin-memmove /link /OPT:NOICF /OPT:NOREF
+// RUN: not %run %t.icf.ref memcpy 2>&1 | FileCheck %s
+// RUN: not %run %t.noicf.ref memcpy 2>&1 | FileCheck %s
+// RUN: not %run %t.icf.noref memcpy 2>&1 | FileCheck %s
+// RUN: not %run %t.noicf.noref memcpy 2>&1 | FileCheck %s
+// RUN: not %run %t.icf.ref memmove 2>&1 | FileCheck %s
+// RUN: not %run %t.noicf.ref memmove 2>&1 | FileCheck %s
+// RUN: not %run %t.icf.noref memmove 2>&1 | FileCheck %s
+// RUN: not %run %t.noicf.noref memmove 2>&1 | FileCheck %s
+// UNSUPPORTED: target={{.*-windows-gnu}}
+
+#include <stdlib.h>
+#include <string.h>
+
+int main(int argc, char **argv) {
+  int *buf = new int[4];
+
+  memmove(buf + 1, buf, 3 * sizeof(int));
+  memcpy(buf + 1, buf, 3 * sizeof(int));
+
+  delete[] buf;
+  if (argc != 2) {
+    abort();
+  }
+  if (strcmp(argv[1], "memcpy") == 0) {
+    memcpy(buf + 1, buf, 3 * sizeof(int));
+  } else if (strcmp(argv[1], "memmove") == 0) {
+    memmove(buf + 1, buf, 3 * sizeof(int));
+  }
+  // CHECK: AddressSanitizer: heap-use-after-free
+
+  return 0;
+}