diff --git a/compiler-rt/lib/profile/GCDAProfiling.c b/compiler-rt/lib/profile/GCDAProfiling.c
index 1079f242406a..51a40c5b67d3 100644
--- a/compiler-rt/lib/profile/GCDAProfiling.c
+++ b/compiler-rt/lib/profile/GCDAProfiling.c
@@ -21,6 +21,7 @@
 \*===----------------------------------------------------------------------===*/
 
 #include "InstrProfilingUtil.h"
+#include "InstrProfilingPort.h"
 
 #include <errno.h>
 #include <fcntl.h>
@@ -194,7 +195,8 @@ static char *mangle_filename(const char *orig_filename) {
   for (level = 0, ptr = fname + 1; level < prefix_strip; ++ptr) {
     if (*ptr == '\0')
       break;
-    if (*ptr != '/')
+
+    if (!IS_DIR_SEPARATOR(*ptr))
       continue;
     fname = ptr;
     ++level;
@@ -205,8 +207,8 @@ static char *mangle_filename(const char *orig_filename) {
   new_filename = malloc(prefix_len + 1 + filename_len + 1);
   memcpy(new_filename, prefix, prefix_len);
 
-  if (prefix[prefix_len - 1] != '/')
-    new_filename[prefix_len++] = '/';
+  if (!IS_DIR_SEPARATOR(prefix[prefix_len - 1]))
+    new_filename[prefix_len++] = DIR_SEPARATOR;
   memcpy(new_filename + prefix_len, fname, filename_len + 1);
 
   return new_filename;
diff --git a/compiler-rt/lib/profile/InstrProfilingFile.c b/compiler-rt/lib/profile/InstrProfilingFile.c
index 1bd6c63395c4..b737baff405b 100644
--- a/compiler-rt/lib/profile/InstrProfilingFile.c
+++ b/compiler-rt/lib/profile/InstrProfilingFile.c
@@ -229,7 +229,11 @@ static void truncateCurrentFile(void) {
     return;
 
   /* Create the directory holding the file, if needed. */
-  if (strchr(Filename, '/') || strchr(Filename, '\\')) {
+  if (strchr(Filename, DIR_SEPARATOR)
+#if defined(DIR_SEPARATOR_2)
+      || strchr(Filename, DIR_SEPERATOR_2)
+#endif
+          ) {
     char *Copy = (char *)COMPILER_RT_ALLOCA(Length + 1);
     strncpy(Copy, Filename, Length + 1);
     __llvm_profile_recursive_mkdir(Copy);
diff --git a/compiler-rt/lib/profile/InstrProfilingPort.h b/compiler-rt/lib/profile/InstrProfilingPort.h
index 4fd8aca4a9da..c947153e2517 100644
--- a/compiler-rt/lib/profile/InstrProfilingPort.h
+++ b/compiler-rt/lib/profile/InstrProfilingPort.h
@@ -84,6 +84,20 @@
   (DomType *)lprofPtrFetchAdd((void **)&PtrVar, sizeof(DomType) * PtrIncr)
 #endif
 
+#if defined(_WIN32)
+#define DIR_SEPARATOR '\\'
+#define DIR_SEPARATOR_2 '/'
+#else
+#define DIR_SEPARATOR '/'
+#endif
+
+#ifndef DIR_SEPARATOR_2
+#define IS_DIR_SEPARATOR(ch) ((ch) == DIR_SEPARATOR)
+#else /* DIR_SEPARATOR_2 */
+#define IS_DIR_SEPARATOR(ch)                                                   \
+  (((ch) == DIR_SEPARATOR) || ((ch) == DIR_SEPARATOR_2))
+#endif /* DIR_SEPARATOR_2 */
+
 #define PROF_ERR(Format, ...)                                                  \
   fprintf(stderr, "LLVM Profile Error: " Format, __VA_ARGS__);