[llvm] [X86][DAGCombiner][SelectionDAG] - Fold Zext Build Vector to Bitcast of widen Build Vector (PR #135010)

[Phoebe Wang via llvm-commits]

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@@ -14295,6 +14295,78 @@ static SDValue widenAbs(SDNode *Extend, SelectionDAG &DAG) {
   return DAG.getZExtOrTrunc(NewAbs, SDLoc(Extend), VT);
 }
 
+// Try to widen the build vector and bitcast it to the type of zext.
+// This is a special case for the 128-bit vector types. Intention is to remove
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phoebewang wrote:

This looks like specific to X86, better to move to X86ISelLowering.

https://github.com/llvm/llvm-project/pull/135010