[PATCH] D89197: [X86] Support -march=x86-64-v[234]

[Fangrui Song via Phabricator via cfe-commits]

MaskRay added inline comments.


================
Comment at: llvm/lib/Target/X86/X86.td:580
   // Nehalem
-  list<SubtargetFeature> NHMFeatures = [FeatureX87,
-                                        FeatureCMPXCHG8B,
-                                        FeatureCMOV,
-                                        FeatureMMX,
-                                        FeatureSSE42,
-                                        FeatureFXSR,
-                                        FeatureNOPL,
-                                        Feature64Bit,
-                                        FeatureCMPXCHG16B,
-                                        FeaturePOPCNT,
-                                        FeatureLAHFSAHF];
+  list<SubtargetFeature> NHMFeatures = X86_64V2Features;
   list<SubtargetFeature> NHMTuning = [FeatureMacroFusion,
----------------
X86_64V2Features = NHMFeatures + SSE2.

Since SSE2 is implied by SSE4.2 , this transformation is sound.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D89197/new/

https://reviews.llvm.org/D89197