Index: include/llvm/Support/Format.h
===================================================================
--- include/llvm/Support/Format.h
+++ include/llvm/Support/Format.h
@@ -125,30 +125,38 @@
   return format_object<Ts...>(Fmt, Vals...);
 }
 
-/// This is a helper class used for left_justify() and right_justify().
+/// This is a helper class for left_justify, right_justify, and center_justify.
 class FormattedString {
   StringRef Str;
   unsigned Width;
-  bool RightJustify;
+  unsigned Justify : 2;
   friend class raw_ostream;
 
 public:
-    FormattedString(StringRef S, unsigned W, bool R)
-      : Str(S), Width(W), RightJustify(R) { }
+    enum Justification { JustifyLeft = 1, JustifyRight = 2, JustifyCenter = 3 };
+    FormattedString(StringRef S, unsigned W, Justification J)
+      : Str(S), Width(W), Justify(J) { }
 };
 
 /// left_justify - append spaces after string so total output is
 /// \p Width characters.  If \p Str is larger that \p Width, full string
 /// is written with no padding.
 inline FormattedString left_justify(StringRef Str, unsigned Width) {
-  return FormattedString(Str, Width, false);
+  return FormattedString(Str, Width, FormattedString::JustifyLeft);
 }
 
 /// right_justify - add spaces before string so total output is
 /// \p Width characters.  If \p Str is larger that \p Width, full string
 /// is written with no padding.
 inline FormattedString right_justify(StringRef Str, unsigned Width) {
-  return FormattedString(Str, Width, true);
+  return FormattedString(Str, Width, FormattedString::JustifyRight);
+}
+
+/// center_justify - add spaces before and after string so total output is
+/// \p Width characters.  If \p Str is larger that \p Width, full string
+/// is written with no padding.
+inline FormattedString center_justify(StringRef Str, unsigned Width) {
+  return FormattedString(Str, Width, FormattedString::JustifyCenter);
 }
 
 /// This is a helper class used for format_hex() and format_decimal().
Index: lib/Support/raw_ostream.cpp
===================================================================
--- lib/Support/raw_ostream.cpp
+++ lib/Support/raw_ostream.cpp
@@ -326,12 +326,20 @@
 }
 
 raw_ostream &raw_ostream::operator<<(const FormattedString &FS) {
-  unsigned Len = FS.Str.size(); 
-  int PadAmount = FS.Width - Len;
-  if (FS.RightJustify && (PadAmount > 0))
+  if (FS.Str.size() >= FS.Width || FS.Justify == 0) {
+    this->operator<<(FS.Str);
+    return *this;
+  }
+  const int Difference = FS.Width - FS.Str.size();
+  int PadAmount = FS.Justify == FormattedString::JustifyCenter ? Difference / 2
+                                                               : Difference;
+  if (FS.Justify & FormattedString::JustifyRight) {
     this->indent(PadAmount);
+    if (FS.Justify == FormattedString::JustifyCenter)
+      PadAmount += Difference - (PadAmount * 2);
+  }
   this->operator<<(FS.Str);
-  if (!FS.RightJustify && (PadAmount > 0))
+  if (FS.Justify & FormattedString::JustifyLeft)
     this->indent(PadAmount);
   return *this;
 }
Index: unittests/Support/raw_ostream_test.cpp
===================================================================
--- unittests/Support/raw_ostream_test.cpp
+++ unittests/Support/raw_ostream_test.cpp
@@ -151,6 +151,11 @@
   EXPECT_EQ("   xyz", printToString(right_justify("xyz", 6), 6));
   EXPECT_EQ("abc",    printToString(right_justify("abc", 3), 3));
   EXPECT_EQ("big",    printToString(right_justify("big", 1), 3));
+  EXPECT_EQ("   on    ",    printToString(center_justify("on", 9), 9));
+  EXPECT_EQ("   off    ",    printToString(center_justify("off", 10), 10));
+  EXPECT_EQ("single ",    printToString(center_justify("single", 7), 7));
+  EXPECT_EQ("none",    printToString(center_justify("none", 1), 4));
+  EXPECT_EQ("none",    printToString(center_justify("none", 1), 1));
 }
 
 TEST(raw_ostreamTest, FormatHex) {