Index: lib/profile/InstrProfilingFile.c
===================================================================
--- lib/profile/InstrProfilingFile.c
+++ lib/profile/InstrProfilingFile.c
@@ -14,6 +14,9 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#ifndef _MSC_VER
+#include <sys/utsname.h>
+#endif
 
 #define UNCONST(ptr) ((void *)(uintptr_t)(ptr))
 
@@ -118,9 +121,12 @@
 static int setFilenamePossiblyWithPid(const char *Filename) {
 #define MAX_PID_SIZE 16
   char PidChars[MAX_PID_SIZE] = {0};
-  int NumPids = 0, PidLength = 0;
+  int NumPids = 0, PidLength = 0, NumNodes = 0, NodeLength = 0;
   char *Allocated;
   int I, J;
+#ifndef _MSC_VER
+  struct utsname Name;
+#endif
 
   /* Reset filename on NULL, except with env var which is checked by caller. */
   if (!Filename) {
@@ -130,19 +136,34 @@
 
   /* Check the filename for "%p", which indicates a pid-substitution. */
   for (I = 0; Filename[I]; ++I)
-    if (Filename[I] == '%' && Filename[++I] == 'p')
-      if (!NumPids++) {
-        PidLength = snprintf(PidChars, MAX_PID_SIZE, "%d", getpid());
-        if (PidLength <= 0)
-          return -1;
+    if (Filename[I] == '%') {
+      if (Filename[++I] == 'p') {
+        if (!NumPids++) {
+          PidLength = snprintf(PidChars, MAX_PID_SIZE, "%d", getpid());
+          if (PidLength <= 0)
+            return -1;
+        }
+      } else if (Filename[I] == 'h') {
+        if (!NumNodes++)
+#ifndef _MSC_VER
+          if (uname(&Name) == -1)
+            return -1;
+
+          NodeLength = strlen(Name.nodename);
+#endif
+          if (NodeLength <= 0)
+            return -1;
       }
-  if (!NumPids) {
+    }
+
+  if (!(NumPids || NumNodes)) {
     setFilename(Filename, 0);
     return 0;
   }
 
   /* Allocate enough space for the substituted filename. */
-  Allocated = malloc(I + NumPids*(PidLength - 2) + 1);
+  Allocated = malloc(I + NumPids*(PidLength - 2) +
+                     NumNodes*(NodeLength - 2) + 1);
   if (!Allocated)
     return -1;
 
@@ -153,6 +174,12 @@
         memcpy(Allocated + J, PidChars, PidLength);
         J += PidLength;
       }
+#ifndef _MSC_VER
+      else if (Filename[I] == 'h') {
+        memcpy(Allocated + J, Name.nodename, NodeLength);
+        J += NodeLength;
+      }
+#endif
       /* Drop any unknown substitutions. */
     } else
       Allocated[J++] = Filename[I];
Index: test/profile/instrprof-hostname.c
===================================================================
--- /dev/null
+++ test/profile/instrprof-hostname.c
@@ -0,0 +1,13 @@
+// RUN: %clang_profgen -o %t -O3 %s
+// RUN: env LLVM_PROFILE_FILE=%h.%t-%h.profraw_%h %run %t
+// RUN: llvm-profdata merge -o %t.profdata `uname -n`.%t-`uname -n`.profraw_`uname -n`
+// RUN: %clang_profuse=%t.profdata -o - -S -emit-llvm %s | FileCheck %s
+// REQUIRES: shell
+
+int main(int argc, const char *argv[]) {
+  // CHECK: br i1 %{{.*}}, label %{{.*}}, label %{{.*}}, !prof ![[PD1:[0-9]+]]
+  if (argc > 2)
+    return 1;
+  return 0;
+}
+// CHECK: ![[PD1]] = !{!"branch_weights", i32 1, i32 2}