1 files changed, 29 insertions, 21 deletions

diff --git a/include/llvm/Support/MathExtras.h b/include/llvm/Support/MathExtras.h
index fa12416..9c5f32c 100644
--- a/include/llvm/Support/MathExtras.h
+++ b/include/llvm/Support/MathExtras.h
@@ -32,35 +32,43 @@ inline uint32_t Lo_32(uint64_t Value) {
   return static_cast<uint32_t>(Value);
 }
 
-/// is?Type - these functions produce optimal testing for integer data types.
-inline bool isInt8  (int64_t Value) {
-  return static_cast<int8_t>(Value) == Value;
-}
-inline bool isUInt8 (int64_t Value) {
-  return static_cast<uint8_t>(Value) == Value;
-}
-inline bool isInt16 (int64_t Value) {
-  return static_cast<int16_t>(Value) == Value;
-}
-inline bool isUInt16(int64_t Value) {
-  return static_cast<uint16_t>(Value) == Value;
-}
-inline bool isInt32 (int64_t Value) {
-  return static_cast<int32_t>(Value) == Value;
-}
-inline bool isUInt32(int64_t Value) {
-  return static_cast<uint32_t>(Value) == Value;
-}
-
+/// isInt - Checks if an integer fits into the given bit width.
 template<unsigned N>
 inline bool isInt(int64_t x) {
   return N >= 64 || (-(INT64_C(1)<<(N-1)) <= x && x < (INT64_C(1)<<(N-1)));
 }
+// Template specializations to get better code for common cases.
+template<>
+inline bool isInt<8>(int64_t x) {
+  return static_cast<int8_t>(x) == x;
+}
+template<>
+inline bool isInt<16>(int64_t x) {
+  return static_cast<int16_t>(x) == x;
+}
+template<>
+inline bool isInt<32>(int64_t x) {
+  return static_cast<int32_t>(x) == x;
+}
 
+/// isUInt - Checks if an unsigned integer fits into the given bit width.
 template<unsigned N>
-inline bool isUint(uint64_t x) {
+inline bool isUInt(uint64_t x) {
   return N >= 64 || x < (UINT64_C(1)<<N);
 }
+// Template specializations to get better code for common cases.
+template<>
+inline bool isUInt<8>(uint64_t x) {
+  return static_cast<uint8_t>(x) == x;
+}
+template<>
+inline bool isUInt<16>(uint64_t x) {
+  return static_cast<uint16_t>(x) == x;
+}
+template<>
+inline bool isUInt<32>(uint64_t x) {
+  return static_cast<uint32_t>(x) == x;
+}
 
 /// isMask_32 - This function returns true if the argument is a sequence of ones
 /// starting at the least significant bit with the remainder zero (32 bit