[llvm] [X86] Use an FP-based expansion for v4i32 ctlz on SSE2-only targets (PR #167034)

[Matt Arsenault via llvm-commits]

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@@ -9480,6 +9480,53 @@ SDValue TargetLowering::expandVPCTLZ(SDNode *Node, SelectionDAG &DAG) const {
   return DAG.getNode(ISD::VP_CTPOP, dl, VT, Op, Mask, VL);
 }
 
+
+SDValue TargetLowering::expandCTLZWithFP(SDNode *Node, SelectionDAG &DAG) const {
+  SDLoc dl(Node);
+  SDValue Op = Node->getOperand(0);
+  EVT VT = Op.getValueType();
+
+  assert(VT.isVector() && "This expansion is intended for vectors");
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arsenm wrote:

Can just write to not have this limitation 

https://github.com/llvm/llvm-project/pull/167034