[PATCH] D132373: [RISCV] When ISD::SETUGT && Imm == -1, processed before lowering

LiqinWeng via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Mon Aug 22 06:03:54 PDT 2022


Miss_Grape created this revision.
Miss_Grape added a reviewer: craig.topper.
Herald added subscribers: sunshaoce, VincentWu, luke957, StephenFan, vkmr, frasercrmck, evandro, luismarques, apazos, sameer.abuasal, s.egerton, Jim, benna, psnobl, jocewei, PkmX, the_o, brucehoult, MartinMosbeck, rogfer01, edward-jones, zzheng, jrtc27, shiva0217, kito-cheng, niosHD, sabuasal, simoncook, johnrusso, rbar, asb, hiraditya, arichardson.
Herald added a project: All.
Miss_Grape requested review of this revision.
Herald added subscribers: llvm-commits, pcwang-thead, eopXD, jacquesguan, MaskRay.
Herald added a project: LLVM.

https://reviews.llvm.org/D132373

Files:
  llvm/lib/Target/RISCV/RISCVISelLowering.cpp


Index: llvm/lib/Target/RISCV/RISCVISelLowering.cpp
===================================================================
--- llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -3636,10 +3636,6 @@
       if (isa<ConstantSDNode>(RHS)) {
         int64_t Imm = cast<ConstantSDNode>(RHS)->getSExtValue();
         if (Imm != 0 && isInt<12>((uint64_t)Imm + 1)) {
-          // If this is an unsigned compare and the constant is -1, incrementing
-          // the constant would change behavior. The result should be false.
-          if (CCVal == ISD::SETUGT && Imm == -1)
-            return DAG.getConstant(0, DL, VT);
           // Using getSetCCSwappedOperands will convert SET(U)GT->SET(U)LT.
           CCVal = ISD::getSetCCSwappedOperands(CCVal);
           SDValue SetCC = DAG.getSetCC(


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D132373.454472.patch
Type: text/x-patch
Size: 832 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20220822/30da120f/attachment.bin>


More information about the llvm-commits mailing list