[llvm] [RISCV] Avoid recreating constants in LowerSelect [nfc] (PR #155628)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-risc-v

Author: Philip Reames (preames)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/155628.diff


1 Files Affected:

- (modified) llvm/lib/Target/RISCV/RISCVISelLowering.cpp (+1-3) 


``````````diff
diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index d1e413b378542..7d6dee44b0274 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -9301,12 +9301,10 @@ SDValue RISCVTargetLowering::lowerSELECT(SDValue Op, SelectionDAG &DAG) const {
                          getCost(TrueVal - FalseVal, FalseVal);
       SDValue LHSVal = DAG.getConstant(
           IsCZERO_NEZ ? FalseVal - TrueVal : TrueVal - FalseVal, DL, VT);
-      SDValue RHSVal =
-          DAG.getConstant(IsCZERO_NEZ ? TrueVal : FalseVal, DL, VT);
       SDValue CMOV =
           DAG.getNode(IsCZERO_NEZ ? RISCVISD::CZERO_NEZ : RISCVISD::CZERO_EQZ,
                       DL, VT, LHSVal, CondV);
-      return DAG.getNode(ISD::ADD, DL, VT, CMOV, RHSVal);
+      return DAG.getNode(ISD::ADD, DL, VT, CMOV, IsCZERO_NEZ ? TrueV : FalseV);
     }
 
     // (select c, c1, t) -> (add (czero_nez t - c1, c), c1)

``````````

</details>


https://github.com/llvm/llvm-project/pull/155628