Add popcnt feature flag to match gcc. This flag is implied when sse42 is enabled, but can be disabled separately. Move popcnt intrinsics to popcntintrin.h to match gcc.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147340 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index bb1051d..a768226 100644
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -1198,6 +1198,7 @@
   bool HasLZCNT;
   bool HasBMI;
   bool HasBMI2;
+  bool HasPOPCNT;
 
   /// \brief Enumeration of all of the X86 CPUs supported by Clang.
   ///
@@ -1335,7 +1336,7 @@
   X86TargetInfo(const std::string& triple)
     : TargetInfo(triple), SSELevel(NoSSE), MMX3DNowLevel(NoMMX3DNow),
       HasAES(false), HasAVX(false), HasAVX2(false), HasLZCNT(false),
-      HasBMI(false), HasBMI2(false), CPU(CK_Generic) {
+      HasBMI(false), HasBMI2(false), HasPOPCNT(false), CPU(CK_Generic) {
     BigEndian = false;
     LongDoubleFormat = &llvm::APFloat::x87DoubleExtended;
   }
@@ -1519,6 +1520,7 @@
   Features["lzcnt"] = false;
   Features["bmi"] = false;
   Features["bmi2"] = false;
+  Features["popcnt"] = false;
 
   // FIXME: This *really* should not be here.
 
@@ -1669,7 +1671,8 @@
         Features["ssse3"] = true;
     else if (Name == "sse4" || Name == "sse4.2")
       Features["mmx"] = Features["sse"] = Features["sse2"] = Features["sse3"] =
-        Features["ssse3"] = Features["sse41"] = Features["sse42"] = true;
+        Features["ssse3"] = Features["sse41"] = Features["sse42"] =
+        Features["popcnt"] = true;
     else if (Name == "sse4.1")
       Features["mmx"] = Features["sse"] = Features["sse2"] = Features["sse3"] =
         Features["ssse3"] = Features["sse41"] = true;
@@ -1682,11 +1685,11 @@
     else if (Name == "avx")
       Features["mmx"] = Features["sse"] = Features["sse2"] = Features["sse3"] =
         Features["ssse3"] = Features["sse41"] = Features["sse42"] =
-        Features["avx"] = true;
+        Features["popcnt"] = Features["avx"] = true;
     else if (Name == "avx2")
       Features["mmx"] = Features["sse"] = Features["sse2"] = Features["sse3"] =
         Features["ssse3"] = Features["sse41"] = Features["sse42"] =
-        Features["avx"] = Features["avx2"] = true;
+        Features["popcnt"] = Features["avx"] = Features["avx2"] = true;
     else if (Name == "sse4a")
       Features["mmx"] = Features["sse4a"] = true;
     else if (Name == "lzcnt")
@@ -1695,6 +1698,8 @@
       Features["bmi"] = true;
     else if (Name == "bmi2")
       Features["bmi2"] = true;
+    else if (Name == "popcnt")
+      Features["popcnt"] = true;
   } else {
     if (Name == "mmx")
       Features["mmx"] = Features["3dnow"] = Features["3dnowa"] = false;
@@ -1731,6 +1736,8 @@
       Features["bmi"] = false;
     else if (Name == "bmi2")
       Features["bmi2"] = false;
+    else if (Name == "popcnt")
+      Features["popcnt"] = false;
   }
 
   return true;
@@ -1765,6 +1772,11 @@
       continue;
     }
 
+    if (Features[i].substr(1) == "popcnt") {
+      HasPOPCNT = true;
+      continue;
+    }
+
     // FIXME: Not sure yet how to treat AVX in regard to SSE levels.
     // For now let it be enabled together with other SSE levels.
     if (Features[i].substr(1) == "avx2") {
@@ -1996,6 +2008,9 @@
   if (HasBMI2)
     Builder.defineMacro("__BMI2__");
 
+  if (HasPOPCNT)
+    Builder.defineMacro("__POPCNT__");
+
   // Each case falls through to the previous one here.
   switch (SSELevel) {
   case SSE42: