Index: cmake/config-ix.cmake
===================================================================
--- cmake/config-ix.cmake
+++ cmake/config-ix.cmake
@@ -7,6 +7,7 @@
 include(CheckLibraryExists)
 include(CheckSymbolExists)
 include(CheckFunctionExists)
+include(CheckStructHasMember)
 include(CheckCCompilerFlag)
 
 include(CheckCompilerVersion)
@@ -248,6 +249,11 @@
   endif()
 endif()
 
+CHECK_STRUCT_HAS_MEMBER("struct stat" st_mtimespec.tv_nsec
+    "sys/types.h;sys/stat.h" HAVE_STRUCT_STAT_ST_MTIMESPEC_TV_NSEC)
+CHECK_STRUCT_HAS_MEMBER("struct stat" st_mtim.tv_nsec
+    "sys/types.h;sys/stat.h" HAVE_STRUCT_STAT_ST_MTIM_TV_NSEC)
+
 check_symbol_exists(__GLIBC__ stdio.h LLVM_USING_GLIBC)
 if( LLVM_USING_GLIBC )
   add_definitions( -D_GNU_SOURCE )
Index: include/llvm/Config/config.h.cmake
===================================================================
--- include/llvm/Config/config.h.cmake
+++ include/llvm/Config/config.h.cmake
@@ -208,6 +208,12 @@
 /* Define to 1 if you have the <sys/time.h> header file. */
 #cmakedefine HAVE_SYS_TIME_H ${HAVE_SYS_TIME_H}
 
+/* Define to 1 if stat struct has st_mtimespec member, and to 0 if it doesn't.*/
+#cmakedefine01 HAVE_STRUCT_STAT_ST_MTIMESPEC_TV_NSEC
+
+/* Define to 1 if stat struct has st_mtim member, and to 0 if it doesn't. */
+#cmakedefine01 HAVE_STRUCT_STAT_ST_MTIM_TV_NSEC
+
 /* Define to 1 if you have the <sys/types.h> header file. */
 #cmakedefine HAVE_SYS_TYPES_H ${HAVE_SYS_TYPES_H}
 
Index: include/llvm/Support/Chrono.h
===================================================================
--- include/llvm/Support/Chrono.h
+++ include/llvm/Support/Chrono.h
@@ -47,6 +47,14 @@
   return time_point_cast<seconds>(system_clock::from_time_t(T));
 }
 
+/// Convert a std::time_t + nanoseconds to a TimePoint
+LLVM_ATTRIBUTE_ALWAYS_INLINE inline TimePoint<>
+toTimePoint(std::time_t T, uint32_t nsec) {
+  using namespace std::chrono;
+  return time_point_cast<nanoseconds>(system_clock::from_time_t(T))
+    + nanoseconds(nsec);
+}
+
 } // namespace sys
 
 raw_ostream &operator<<(raw_ostream &OS, sys::TimePoint<> TP);
Index: include/llvm/Support/FileSystem.h
===================================================================
--- include/llvm/Support/FileSystem.h
+++ include/llvm/Support/FileSystem.h
@@ -160,6 +160,8 @@
   #if defined(LLVM_ON_UNIX)
   time_t fs_st_atime = 0;
   time_t fs_st_mtime = 0;
+  uint32_t fs_st_atime_nsec = 0;
+  uint32_t fs_st_mtime_nsec = 0;
   uid_t fs_st_uid = 0;
   gid_t fs_st_gid = 0;
   off_t fs_st_size = 0;
@@ -180,9 +182,12 @@
   explicit basic_file_status(file_type Type) : Type(Type) {}
 
   #if defined(LLVM_ON_UNIX)
-  basic_file_status(file_type Type, perms Perms, time_t ATime, time_t MTime,
+  basic_file_status(file_type Type, perms Perms, time_t ATime,
+                    uint32_t ATimeNSec, time_t MTime, uint32_t MTimeNSec,
                     uid_t UID, gid_t GID, off_t Size)
-      : fs_st_atime(ATime), fs_st_mtime(MTime), fs_st_uid(UID), fs_st_gid(GID),
+      : fs_st_atime(ATime), fs_st_mtime(MTime),
+        fs_st_atime_nsec(ATimeNSec), fs_st_mtime_nsec(MTimeNSec),
+        fs_st_uid(UID), fs_st_gid(GID),
         fs_st_size(Size), Type(Type), Perms(Perms) {}
 #elif defined(_WIN32)
   basic_file_status(file_type Type, perms Perms, uint32_t LastAccessTimeHigh,
@@ -247,8 +252,11 @@
 
   #if defined(LLVM_ON_UNIX)
   file_status(file_type Type, perms Perms, dev_t Dev, nlink_t Links, ino_t Ino,
-              time_t ATime, time_t MTime, uid_t UID, gid_t GID, off_t Size)
-      : basic_file_status(Type, Perms, ATime, MTime, UID, GID, Size),
+              time_t ATime, uint32_t ATimeNSec,
+              time_t MTime, uint32_t MTimeNSec,
+              uid_t UID, gid_t GID, off_t Size)
+      : basic_file_status(Type, Perms, ATime, ATimeNSec, MTime, MTimeNSec,
+                          UID, GID, Size),
         fs_st_dev(Dev), fs_st_nlinks(Links), fs_st_ino(Ino) {}
   #elif defined(_WIN32)
   file_status(file_type Type, perms Perms, uint32_t LinkCount,
Index: lib/Support/Unix/Path.inc
===================================================================
--- lib/Support/Unix/Path.inc
+++ lib/Support/Unix/Path.inc
@@ -229,11 +229,11 @@
 }
 
 TimePoint<> basic_file_status::getLastAccessedTime() const {
-  return toTimePoint(fs_st_atime);
+  return toTimePoint(fs_st_atime, fs_st_atime_nsec);
 }
 
 TimePoint<> basic_file_status::getLastModificationTime() const {
-  return toTimePoint(fs_st_mtime);
+  return toTimePoint(fs_st_mtime, fs_st_mtime_nsec);
 }
 
 UniqueID file_status::getUniqueID() const {
@@ -591,11 +591,22 @@
     return EC;
   }
 
+  uint32_t atime_nsec, mtime_nsec;
+#if HAVE_STRUCT_STAT_ST_MTIMESPEC_TV_NSEC
+  atime_nsec = Status.st_atimespec.tv_nsec;
+  mtime_nsec = Status.st_mtimespec.tv_nsec;
+#elif HAVE_STRUCT_STAT_ST_MTIM_TV_NSEC
+  atime_nsec = Status.st_atim.tv_nsec;
+  mtime_nsec = Status.st_mtim.tv_nsec;
+#else
+  atime_nsec = mtime_nsec = 0;
+#endif
+
   perms Perms = static_cast<perms>(Status.st_mode) & all_perms;
   Result = file_status(typeForMode(Status.st_mode), Perms, Status.st_dev,
-                       Status.st_nlink, Status.st_ino, Status.st_atime,
-                       Status.st_mtime, Status.st_uid, Status.st_gid,
-                       Status.st_size);
+                       Status.st_nlink, Status.st_ino,
+                       Status.st_atime, atime_nsec, Status.st_mtime, mtime_nsec,
+                       Status.st_uid, Status.st_gid, Status.st_size);
 
   return std::error_code();
 }