[llvm] [ISel] Introduce `llvm.pext` and `llvm.pdep` intrinsics (PR #200570)

[Craig Topper via llvm-commits]

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@@ -5566,6 +5572,14 @@ void SelectionDAGLegalize::PromoteNode(SDNode *Node) {
     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, CTLZResult));
     break;
   }
+  case ISD::PEXT:
+  case ISD::PDEP: {
+    Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
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topperc wrote:

I think we can always use ANY_EXTEND for operand 0. And we can use ANY_EXTEND for operand 1 of PDEP.

https://github.com/llvm/llvm-project/pull/200570