[llvm] [RISCV] Use getNegative instead of subtracting from zero. NFC (PR #162313)

Sudharsan Veeravalli via llvm-commits llvm-commits at lists.llvm.org
Tue Oct 7 09:11:55 PDT 2025


https://github.com/svs-quic created https://github.com/llvm/llvm-project/pull/162313

None

>From 6024848a787761a67854ba7a0cccd68c335e0e32 Mon Sep 17 00:00:00 2001
From: Sudharsan Veeravalli <quic_svs at quicinc.com>
Date: Tue, 7 Oct 2025 21:09:49 +0530
Subject: [PATCH] [RISCV] Use getNegative instead of subtracting from zero. NFC

---
 llvm/lib/Target/RISCV/RISCVISelLowering.cpp | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index a3a4cf26f94d5..7123a2d706787 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -15721,8 +15721,7 @@ static SDValue combineAddOfBooleanXor(SDNode *N, SelectionDAG &DAG) {
     return SDValue();
 
   // Emit a negate of the setcc.
-  return DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, DL, VT),
-                     N0.getOperand(0));
+  return DAG.getNegative(N0.getOperand(0), DL, VT);
 }
 
 static SDValue performADDCombine(SDNode *N,
@@ -16974,7 +16973,7 @@ performSIGN_EXTEND_INREGCombine(SDNode *N, TargetLowering::DAGCombinerInfo &DCI,
 
   // Fold (sext_inreg (setcc), i1) -> (sub 0, (setcc))
   if (Opc == ISD::SETCC && SrcVT == MVT::i1 && DCI.isAfterLegalizeDAG())
-    return DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, DL, VT), Src);
+    return DAG.getNegative(Src, DL, VT);
 
   // Fold (sext_inreg (xor (setcc), -1), i1) -> (add (setcc), -1)
   if (Opc == ISD::XOR && SrcVT == MVT::i1 &&



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