[llvm] [X86] Fix an assembler bug of CMPCCXADD. (PR #66748)

[Freddy Ye via llvm-commits]

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@@ -948,10 +948,10 @@ X86MCCodeEmitter::emitVEXOpcodePrefix(int MemOperand, const MCInst &MI,
     llvm_unreachable("Unexpected form in emitVEXOpcodePrefix!");
   case X86II::MRMDestMem4VOp3CC: {
     //  MemAddr, src1(ModR/M), src2(VEX_4V)
+    Prefix.setR(MI, CurOp++);
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FreddyLeaf wrote:

You are correct. addressed in [1e66d6c](https://github.com/llvm/llvm-project/pull/66748/commits/1e66d6cc36130cd9d66e2233b3a78c3ca4222721)

https://github.com/llvm/llvm-project/pull/66748