[llvm] [ISel] Introduce llvm.clmul intrinsic (PR #168731)

[Craig Topper via llvm-commits]

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@@ -11420,6 +11420,31 @@ SDValue DAGCombiner::visitSRL(SDNode *N) {
   if (SDValue AVG = foldShiftToAvg(N, DL))
     return AVG;
 
+  SDValue Y;
+  if (VT.getScalarSizeInBits() % 2 == 0) {
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topperc wrote:

Check that N1C is non-null here?

https://github.com/llvm/llvm-project/pull/168731