diff --git a/lib/Support/raw_ostream.cpp b/lib/Support/raw_ostream.cpp
index 4c3348d8309..e7e4ad3f906 100644
--- a/lib/Support/raw_ostream.cpp
+++ b/lib/Support/raw_ostream.cpp
@@ -123,24 +123,19 @@ raw_ostream &raw_ostream::operator<<(long N) {
 }
 
 raw_ostream &raw_ostream::operator<<(unsigned long long N) {
-  // Handle simple case when value fits in long already.
+  // Output using 32-bit div/mod when possible.
   if (N == static_cast<unsigned long>(N))
     return this->operator<<(static_cast<unsigned long>(N));
 
-  // Otherwise divide into at two or three 10**9 chunks and write out using
-  // long div/mod, this is substantially faster on a 32-bit system.
-  unsigned long Top = 0, Mid = 0, Bot = N % 1000000000;
-  N /= 1000000000;
-  if (N > 1000000000) {
-    Mid = N % 1000000000;
-    Top = N / 1000000000;
-  } else
-    Mid = N;
-
-  if (Top)
-    this->operator<<(static_cast<unsigned long>(Top));
-  this->operator<<(static_cast<unsigned long>(Mid));
-  return this->operator<<(static_cast<unsigned long>(Bot));
+  char NumberBuffer[20];
+  char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
+  char *CurPtr = EndPtr;
+  
+  while (N) {
+    *--CurPtr = '0' + char(N % 10);
+    N /= 10;
+  }
+  return write(CurPtr, EndPtr-CurPtr);
 }
 
 raw_ostream &raw_ostream::operator<<(long long N) {