diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp --- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp +++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp @@ -8308,6 +8308,11 @@ CCVal = ISD::getSetCCInverse(CCVal, SetCCOpVT); NewLHS = DAG.getSetCC(SDLoc(N1), VT, N1.getOperand(0), N1.getOperand(1), CCVal); + } else if (N1.getOpcode() == ISD::XOR && isOneConstant(N1.getOperand(1)) && + N1.getOperand(0).getOpcode() == ISD::SETCC) { + // (sub C, (xor (setcc), 1)) -> (add (setcc), C-1). + // Since setcc returns a bool the xor is equivalent to 1-setcc. + NewLHS = N1.getOperand(0); } else return SDValue(); diff --git a/llvm/test/CodeGen/RISCV/double-select-fcmp.ll b/llvm/test/CodeGen/RISCV/double-select-fcmp.ll --- a/llvm/test/CodeGen/RISCV/double-select-fcmp.ll +++ b/llvm/test/CodeGen/RISCV/double-select-fcmp.ll @@ -258,8 +258,7 @@ ; CHECK-LABEL: select_fcmp_uge_negone_zero: ; CHECK: # %bb.0: ; CHECK-NEXT: fle.d a0, fa0, fa1 -; CHECK-NEXT: xori a0, a0, 1 -; CHECK-NEXT: neg a0, a0 +; CHECK-NEXT: addi a0, a0, -1 ; CHECK-NEXT: ret %1 = fcmp ugt double %a, %b %2 = select i1 %1, i32 -1, i32 0 @@ -270,9 +269,7 @@ ; CHECK-LABEL: select_fcmp_uge_1_2: ; CHECK: # %bb.0: ; CHECK-NEXT: fle.d a0, fa0, fa1 -; CHECK-NEXT: xori a0, a0, 1 -; CHECK-NEXT: li a1, 2 -; CHECK-NEXT: sub a0, a1, a0 +; CHECK-NEXT: addi a0, a0, 1 ; CHECK-NEXT: ret %1 = fcmp ugt double %a, %b %2 = select i1 %1, i32 1, i32 2 diff --git a/llvm/test/CodeGen/RISCV/float-select-fcmp.ll b/llvm/test/CodeGen/RISCV/float-select-fcmp.ll --- a/llvm/test/CodeGen/RISCV/float-select-fcmp.ll +++ b/llvm/test/CodeGen/RISCV/float-select-fcmp.ll @@ -258,8 +258,7 @@ ; CHECK-LABEL: select_fcmp_uge_negone_zero: ; CHECK: # %bb.0: ; CHECK-NEXT: fle.s a0, fa0, fa1 -; CHECK-NEXT: xori a0, a0, 1 -; CHECK-NEXT: neg a0, a0 +; CHECK-NEXT: addi a0, a0, -1 ; CHECK-NEXT: ret %1 = fcmp ugt float %a, %b %2 = select i1 %1, i32 -1, i32 0 @@ -270,9 +269,7 @@ ; CHECK-LABEL: select_fcmp_uge_1_2: ; CHECK: # %bb.0: ; CHECK-NEXT: fle.s a0, fa0, fa1 -; CHECK-NEXT: xori a0, a0, 1 -; CHECK-NEXT: li a1, 2 -; CHECK-NEXT: sub a0, a1, a0 +; CHECK-NEXT: addi a0, a0, 1 ; CHECK-NEXT: ret %1 = fcmp ugt float %a, %b %2 = select i1 %1, i32 1, i32 2 diff --git a/llvm/test/CodeGen/RISCV/half-select-fcmp.ll b/llvm/test/CodeGen/RISCV/half-select-fcmp.ll --- a/llvm/test/CodeGen/RISCV/half-select-fcmp.ll +++ b/llvm/test/CodeGen/RISCV/half-select-fcmp.ll @@ -258,8 +258,7 @@ ; CHECK-LABEL: select_fcmp_uge_negone_zero: ; CHECK: # %bb.0: ; CHECK-NEXT: fle.h a0, fa0, fa1 -; CHECK-NEXT: xori a0, a0, 1 -; CHECK-NEXT: neg a0, a0 +; CHECK-NEXT: addi a0, a0, -1 ; CHECK-NEXT: ret %1 = fcmp ugt half %a, %b %2 = select i1 %1, i32 -1, i32 0 @@ -270,9 +269,7 @@ ; CHECK-LABEL: select_fcmp_uge_1_2: ; CHECK: # %bb.0: ; CHECK-NEXT: fle.h a0, fa0, fa1 -; CHECK-NEXT: xori a0, a0, 1 -; CHECK-NEXT: li a1, 2 -; CHECK-NEXT: sub a0, a1, a0 +; CHECK-NEXT: addi a0, a0, 1 ; CHECK-NEXT: ret %1 = fcmp ugt half %a, %b %2 = select i1 %1, i32 1, i32 2