[llvm] [X86] combinePTESTCC - fold PTESTZ(X,SIGNMASK) -> VTESTPD/PSZ(X,X) on AVX targets (PR #165676)

[Phoebe Wang via llvm-commits]

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@@ -48859,6 +48859,26 @@ static SDValue combinePTESTCC(SDValue EFLAGS, X86::CondCode &CC,
     if (ISD::isBuildVectorAllOnes(Op1.getNode()))
       return DAG.getNode(EFLAGS.getOpcode(), SDLoc(EFLAGS), VT, Op0, Op0);
 
+    // Attempt to convert PTESTZ(X,SIGNMASK) -> VTESTPD/PSZ(X,X) on AVX targets.
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phoebewang wrote:

Do we need to freeze `X`?

https://github.com/llvm/llvm-project/pull/165676