Separate popcnt and sse4.2 feature control somewhat to match gcc behavior.

Enabling sse4.2 will implicitly enable popcnt unless popcnt is explicitly disabled.
Disabling sse4.2 will not disable popcnt if popcnt is explicitly enabled.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@190387 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index 64b00d7fae313508d68f823eb155ba8029f87f70..665f10163348227e27530b30368d883980b030e4 100644 (file)
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -2133,7 +2133,7 @@ void X86TargetInfo::setSSELevel(llvm::StringMap<bool> &Features,
     case AVX:
       Features["avx"] = true;
     case SSE42:
-      Features["popcnt"] = Features["sse4.2"] = true;
+      Features["sse4.2"] = true;
     case SSE41:
       Features["sse4.1"] = true;
     case SSSE3:
@@ -2166,7 +2166,7 @@ void X86TargetInfo::setSSELevel(llvm::StringMap<bool> &Features,
   case SSE41:
     Features["sse4.1"] = false;
   case SSE42:
-    Features["popcnt"] = Features["sse4.2"] = false;
+    Features["sse4.2"] = false;
   case AVX:
     Features["fma"] = Features["avx"] = false;
     setXOPLevel(Features, FMA4, false);
@@ -2406,6 +2406,15 @@ bool X86TargetInfo::HandleTargetFeatures(std::vector<std::string> &Features,
     XOPLevel = std::max(XOPLevel, XLevel);
   }
 
+  // Enable popcnt if sse4.2 is enabled and popcnt is not explicitly disabled.
+  // Can't do this earlier because we need to be able to explicitly enable
+  // popcnt and still disable sse4.2.
+  if (!HasPOPCNT && SSELevel >= SSE42 &&
+      std::find(Features.begin(), Features.end(), "-popcnt") == Features.end()){
+    HasPOPCNT = true;
+    Features.push_back("+popcnt");
+  }
+
   // LLVM doesn't have a separate switch for fpmath, so only accept it if it
   // matches the selected sse level.
   if (FPMath == FP_SSE && SSELevel < SSE1) {

diff --git a/test/Preprocessor/x86_target_features.c b/test/Preprocessor/x86_target_features.c
index d6ddc01b53ec3df32d65115928dd5140258ef670..48d5bcb65b974b0290a6fe13be1ee6a21441050f 100644 (file)
--- a/test/Preprocessor/x86_target_features.c
+++ b/test/Preprocessor/x86_target_features.c
@@ -128,3 +128,15 @@
 // AVX512F2: #define __SSE_MATH__ 1
 // AVX512F2: #define __SSE__ 1
 // AVX512F2: #define __SSSE3__ 1
+
+// RUN: %clang -target i386-unknown-unknown -march=atom -msse4.2 -x c -E -dM -o - %s | FileCheck --check-prefix=SSE42POPCNT %s
+
+// SSE42POPCNT: #define __POPCNT__ 1
+
+// RUN: %clang -target i386-unknown-unknown -march=atom -mno-popcnt -msse4.2 -x c -E -dM -o - %s | FileCheck --check-prefix=SSE42NOPOPCNT %s
+
+// SSE42NOPOPCNT-NOT: #define __POPCNT__ 1
+
+// RUN: %clang -target i386-unknown-unknown -march=atom -mpopcnt -mno-sse4.2 -x c -E -dM -o - %s | FileCheck --check-prefix=NOSSE42POPCNT %s
+
+// NOSSE42POPCNT: #define __POPCNT__ 1