From a393238422ecadf56826d4f1a3562fbf2dcab849 Mon Sep 17 00:00:00 2001 From: Petar Avramovic Date: Tue, 27 Aug 2019 14:33:05 +0000 Subject: [PATCH] [GlobalISel] Factor narrowScalar for G_ASHR and G_LSHR. NFC Main difference is in the way Hi for Long shift (HiL) is made. G_LSHR fills HiL with zeros, while G_ASHR fills HiL with sign bit value. Differential Revision: https://reviews.llvm.org/D66589 llvm-svn: 370064 --- .../CodeGen/GlobalISel/LegalizerHelper.cpp | 38 ++++++------------- 1 file changed, 11 insertions(+), 27 deletions(-) diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp index 8608cb8f6e08..c5451708d1b9 100644 --- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp +++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp @@ -3010,41 +3010,25 @@ LegalizerHelper::narrowScalarShift(MachineInstr &MI, unsigned TypeIdx, ResultRegs[1] = Hi.getReg(0); break; } - case TargetOpcode::G_LSHR: { - // Short: ShAmt < NewBitSize - auto HiS = MIRBuilder.buildLShr(HalfTy, InH, Amt); - - auto LoOr = MIRBuilder.buildLShr(HalfTy, InL, Amt); - auto HiOr = MIRBuilder.buildShl(HalfTy, InH, AmtLack); - auto LoS = MIRBuilder.buildOr(HalfTy, LoOr, HiOr); - - // Long: ShAmt >= NewBitSize - auto HiL = MIRBuilder.buildConstant(HalfTy, 0); // Hi part is zero. - auto LoL = MIRBuilder.buildLShr(HalfTy, InH, AmtExcess); // Lo from Hi part. - - auto Lo = MIRBuilder.buildSelect( - HalfTy, IsZero, InL, MIRBuilder.buildSelect(HalfTy, IsShort, LoS, LoL)); - auto Hi = MIRBuilder.buildSelect(HalfTy, IsShort, HiS, HiL); - - ResultRegs[0] = Lo.getReg(0); - ResultRegs[1] = Hi.getReg(0); - break; - } + case TargetOpcode::G_LSHR: case TargetOpcode::G_ASHR: { // Short: ShAmt < NewBitSize - auto HiS = MIRBuilder.buildAShr(HalfTy, InH, Amt); + auto HiS = MIRBuilder.buildInstr(MI.getOpcode(), {HalfTy}, {InH, Amt}); auto LoOr = MIRBuilder.buildLShr(HalfTy, InL, Amt); auto HiOr = MIRBuilder.buildShl(HalfTy, InH, AmtLack); auto LoS = MIRBuilder.buildOr(HalfTy, LoOr, HiOr); // Long: ShAmt >= NewBitSize - - // Sign of Hi part. - auto HiL = MIRBuilder.buildAShr( - HalfTy, InH, MIRBuilder.buildConstant(ShiftAmtTy, NewBitSize - 1)); - - auto LoL = MIRBuilder.buildAShr(HalfTy, InH, AmtExcess); // Lo from Hi part. + MachineInstrBuilder HiL; + if (MI.getOpcode() == TargetOpcode::G_LSHR) { + HiL = MIRBuilder.buildConstant(HalfTy, 0); // Hi part is zero. + } else { + auto ShiftAmt = MIRBuilder.buildConstant(ShiftAmtTy, NewBitSize - 1); + HiL = MIRBuilder.buildAShr(HalfTy, InH, ShiftAmt); // Sign of Hi part. + } + auto LoL = MIRBuilder.buildInstr(MI.getOpcode(), {HalfTy}, + {InH, AmtExcess}); // Lo from Hi part. auto Lo = MIRBuilder.buildSelect( HalfTy, IsZero, InL, MIRBuilder.buildSelect(HalfTy, IsShort, LoS, LoL));