Index: include/llvm/Support/ScopedPrinter.h
===================================================================
--- include/llvm/Support/ScopedPrinter.h
+++ include/llvm/Support/ScopedPrinter.h
@@ -11,12 +11,14 @@
 
 #include "llvm/ADT/APSInt.h"
 #include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/DataTypes.h"
 #include "llvm/Support/Endian.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
+#include <limits>
 
 namespace llvm {
 
@@ -58,13 +60,34 @@
 raw_ostream &operator<<(raw_ostream &OS, const HexNumber &Value);
 const std::string to_hexString(uint64_t Value, bool UpperCase = true);
 
-template <class T> const std::string to_string(const T &Value) {
+template <class T, typename = typename std::enable_if<
+                       !std::numeric_limits<T>::is_specialized>::type>
+const std::string to_string(const T &Value) {
   std::string number;
   llvm::raw_string_ostream stream(number);
   stream << Value;
   return stream.str();
 }
 
+template <class T,
+          typename = typename std::enable_if<
+              std::numeric_limits<T>::is_specialized>::type,
+          void * = nullptr>
+const std::string to_string(const T &Value) {
+  static constexpr auto NumDigits = std::numeric_limits<T>::is_integer
+                                        ? std::numeric_limits<T>::digits10
+                                        : std::numeric_limits<T>::max_digits10;
+  // Optional char for sign bit, plus the required number of base-10 digits.
+  // If integer - then +1 is for rounding up. Else, for the decimal separator.
+  static constexpr auto BufLen =
+      std::numeric_limits<T>::is_signed + NumDigits + 1;
+  llvm::SmallString<BufLen> number;
+  llvm::raw_svector_ostream stream(number);
+  stream << Value;
+  assert(stream.str().size() <= BufLen && "small size prediction failed");
+  return stream.str();
+}
+
 class ScopedPrinter {
 public:
   ScopedPrinter(raw_ostream &OS) : OS(OS), IndentLevel(0) {}