[llvm] [RISC-V][ISel] Remove redundant czero.eqz like 'czero.eqz a0, a0, a0' (PR #90208)

[Zhijin Zeng via llvm-commits]

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@@ -7503,6 +7503,25 @@ SDValue RISCVTargetLowering::lowerSELECT(SDValue Op, SelectionDAG &DAG) const {
       return DAG.getNode(ISD::ADD, DL, VT, CMOV, RHSVal);
     }
 
+    if (CondV.getOpcode() == ISD::SETCC) {
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zengdage wrote:

Hi @yetingk , according to @dtcxzyw  suggestion, I deleted the code here,  and changed in `RISCVTargetLowering: : PerformDAGCombine.` Thanks.

https://github.com/llvm/llvm-project/pull/90208