[llvm] [DAG] Peek through bitcasts when canonicalizing constants to the RHS on commutable instructions (PR #112682)

[Simon Pilgrim via llvm-commits]

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@@ -2668,8 +2668,8 @@ SDValue DAGCombiner::visitADDLike(SDNode *N) {
     return C;
 
   // canonicalize constant to RHS
-  if (DAG.isConstantIntBuildVectorOrConstantInt(N0) &&
-      !DAG.isConstantIntBuildVectorOrConstantInt(N1))
+  if (DAG.isConstantIntBuildVectorOrConstantInt(peekThroughBitcasts(N0)) &&
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RKSimon wrote:

Yes, although we would need to make it return bool instead of the SDNode (which is barely used tbh).

https://github.com/llvm/llvm-project/pull/112682