[Support] Add MSVC intrinsic for CountPopulation.

Patch by Jakub Staszak.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172645 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/Support/MathExtras.h b/include/llvm/Support/MathExtras.h
index 11f9e63c9bbcafa849f49177c20d9ecafc4d01d7..10911ea11c51ea96e8d4edf0a4b05e7b6a9c21f7 100644 (file)
--- a/include/llvm/Support/MathExtras.h
+++ b/include/llvm/Support/MathExtras.h
@@ -299,6 +299,8 @@ inline unsigned CountTrailingOnes_64(uint64_t Value) {
 inline unsigned CountPopulation_32(uint32_t Value) {
 #if __GNUC__ >= 4
   return __builtin_popcount(Value);
+#elif _MSC_VER
+  return __popcnt(Value);
 #else
   uint32_t v = Value - ((Value >> 1) & 0x55555555);
   v = (v & 0x33333333) + ((v >> 2) & 0x33333333);
@@ -311,6 +313,8 @@ inline unsigned CountPopulation_32(uint32_t Value) {
 inline unsigned CountPopulation_64(uint64_t Value) {
 #if __GNUC__ >= 4
   return __builtin_popcountll(Value);
+#elif _MSC_VER
+  return __popcnt64(Value);
 #else
   uint64_t v = Value - ((Value >> 1) & 0x5555555555555555ULL);
   v = (v & 0x3333333333333333ULL) + ((v >> 2) & 0x3333333333333333ULL);