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

[Simon Pilgrim via llvm-commits]

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@@ -3526,7 +3526,7 @@ static unsigned CopyToFromAsymmetricReg(unsigned DestReg, unsigned SrcReg,
   // All KMASK RegClasses hold the same k registers, can be tested against anyone.
   if (X86::VK16RegClass.contains(SrcReg)) {
     if (X86::GR64RegClass.contains(DestReg)) {
-      assert(Subtarget.hasBWI());
+      assert(Subtarget.hasBWI() && Subtarget.hasEVEX512());
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RKSimon wrote:

(style) If you're updating the assert, add an assertion message to match coding guidelines 

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