[llvm] [X86] Compute `CTLZ` using fp math for `v4i32` on SSE2 targets (PR #190930)

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``````````bash
git-clang-format --diff origin/main HEAD --extensions cpp,h -- llvm/include/llvm/CodeGen/TargetLowering.h llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp llvm/lib/Target/X86/X86ISelLowering.cpp --diff_from_common_commit
``````````

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``````````diff
diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index b54bcc9a6..d629efe6b 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -9901,7 +9901,8 @@ SDValue TargetLowering::expandCTLZWithFP(SDNode *Node,
   EVT HalfFloatVT = HalfVT.changeVectorElementType(*DAG.getContext(), MVT::f64);
   EVT HalfFloatBitsVT = HalfFloatVT.changeVectorElementTypeToInteger();
 
-  const fltSemantics &Sem = HalfFloatVT.getVectorElementType().getFltSemantics();
+  const fltSemantics &Sem =
+      HalfFloatVT.getVectorElementType().getFltSemantics();
   unsigned BitWidth = EltVT.getSizeInBits();
   unsigned MantissaBits = APFloat::semanticsPrecision(Sem);
   unsigned ExponentBias = APFloat::semanticsMaxExponent(Sem);
@@ -9909,7 +9910,8 @@ SDValue TargetLowering::expandCTLZWithFP(SDNode *Node,
   auto ComputeExp = [&](SDValue Half) {
     SDValue Float = DAG.getNode(ISD::UINT_TO_FP, dl, HalfFloatVT, Half);
     SDValue Bits = DAG.getBitcast(HalfFloatBitsVT, Float);
-    SDValue Exp = DAG.getNode(ISD::SRL, dl, HalfFloatBitsVT, Bits,
+    SDValue Exp = DAG.getNode(
+        ISD::SRL, dl, HalfFloatBitsVT, Bits,
         DAG.getShiftAmountConstant(MantissaBits - 1, HalfFloatBitsVT, dl));
     return DAG.getNode(ISD::TRUNCATE, dl, HalfVT, Exp);
   };
@@ -9917,9 +9919,11 @@ SDValue TargetLowering::expandCTLZWithFP(SDNode *Node,
   SDValue ExpTruncLo = ComputeExp(DAG.getExtractSubvector(dl, HalfVT, Op, 0));
   SDValue ExpTruncHi = ComputeExp(
       DAG.getExtractSubvector(dl, HalfVT, Op, VT.getVectorNumElements() / 2));
-  SDValue Exp = DAG.getNode(ISD::CONCAT_VECTORS, dl, VT, ExpTruncLo, ExpTruncHi);
-  SDValue NonZeroRes = DAG.getNode(ISD::SUB, dl, VT,
-      DAG.getConstant(BitWidth - 1 + ExponentBias, dl, VT), Exp);
+  SDValue Exp =
+      DAG.getNode(ISD::CONCAT_VECTORS, dl, VT, ExpTruncLo, ExpTruncHi);
+  SDValue NonZeroRes =
+      DAG.getNode(ISD::SUB, dl, VT,
+                  DAG.getConstant(BitWidth - 1 + ExponentBias, dl, VT), Exp);
 
   // Skip Op == 0 case for CTLZ_ZERO_UNDEF
   if (Node->getOpcode() == ISD::CTLZ_ZERO_UNDEF)

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https://github.com/llvm/llvm-project/pull/190930