[llvm] [X86] Fix optmasks handling for AVX10.1-256 (PR #73074)

[Aiden Grossman via llvm-commits]

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@@ -939,7 +939,8 @@ std::vector<MCInst> ExegesisX86Target::setRegTo(const MCSubtargetInfo &STI,
       }
       break;
     case 64:
-      if (STI.getFeatureBits()[X86::FeatureBWI]) {
+      if (STI.getFeatureBits()[X86::FeatureBWI] &&
+          STI.getFeatureBits()[X86::FeatureEVEX512]) {
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boomanaiden154 wrote:

It looks like this could benefit from a test in `llvm/unittests/tools/llvm-exegesis/X86/TargetTest.cpp`. If it's too much effort here though, I can open up a patch adding a test once this lands.

https://github.com/llvm/llvm-project/pull/73074