diff options
Diffstat (limited to 'contrib/llvm/lib/CodeGen/ProcessImplicitDefs.cpp')
-rw-r--r-- | contrib/llvm/lib/CodeGen/ProcessImplicitDefs.cpp | 69 |
1 files changed, 51 insertions, 18 deletions
diff --git a/contrib/llvm/lib/CodeGen/ProcessImplicitDefs.cpp b/contrib/llvm/lib/CodeGen/ProcessImplicitDefs.cpp index 62f525f..2e31908 100644 --- a/contrib/llvm/lib/CodeGen/ProcessImplicitDefs.cpp +++ b/contrib/llvm/lib/CodeGen/ProcessImplicitDefs.cpp @@ -41,18 +41,48 @@ void ProcessImplicitDefs::getAnalysisUsage(AnalysisUsage &AU) const { MachineFunctionPass::getAnalysisUsage(AU); } -bool ProcessImplicitDefs::CanTurnIntoImplicitDef(MachineInstr *MI, - unsigned Reg, unsigned OpIdx, - const TargetInstrInfo *tii_) { +bool +ProcessImplicitDefs::CanTurnIntoImplicitDef(MachineInstr *MI, + unsigned Reg, unsigned OpIdx, + const TargetInstrInfo *tii_, + SmallSet<unsigned, 8> &ImpDefRegs) { unsigned SrcReg, DstReg, SrcSubReg, DstSubReg; if (tii_->isMoveInstr(*MI, SrcReg, DstReg, SrcSubReg, DstSubReg) && - Reg == SrcReg && SrcSubReg == 0 && DstSubReg == 0) + Reg == SrcReg && + (DstSubReg == 0 || ImpDefRegs.count(DstReg))) return true; - if (OpIdx == 2 && MI->isSubregToReg()) - return true; - if (OpIdx == 1 && MI->isExtractSubreg()) - return true; + switch(OpIdx) { + case 1: + return MI->isCopy() && (MI->getOperand(0).getSubReg() == 0 || + ImpDefRegs.count(MI->getOperand(0).getReg())); + case 2: + return MI->isSubregToReg() && (MI->getOperand(0).getSubReg() == 0 || + ImpDefRegs.count(MI->getOperand(0).getReg())); + default: return false; + } +} + +static bool isUndefCopy(MachineInstr *MI, unsigned Reg, + const TargetInstrInfo *tii_, + SmallSet<unsigned, 8> &ImpDefRegs) { + if (MI->isCopy()) { + MachineOperand &MO0 = MI->getOperand(0); + MachineOperand &MO1 = MI->getOperand(1); + if (MO1.getReg() != Reg) + return false; + if (!MO0.getSubReg() || ImpDefRegs.count(MO0.getReg())) + return true; + return false; + } + + unsigned SrcReg, DstReg, SrcSubReg, DstSubReg; + if (tii_->isMoveInstr(*MI, SrcReg, DstReg, SrcSubReg, DstSubReg)) { + if (Reg != SrcReg) + return false; + if (DstSubReg == 0 || ImpDefRegs.count(DstReg)) + return true; + } return false; } @@ -101,11 +131,10 @@ bool ProcessImplicitDefs::runOnMachineFunction(MachineFunction &fn) { continue; } - if (MI->isInsertSubreg()) { - MachineOperand &MO = MI->getOperand(2); - if (ImpDefRegs.count(MO.getReg())) { - // %reg1032<def> = INSERT_SUBREG %reg1032, undef, 2 - // This is an identity copy, eliminate it now. + // Eliminate %reg1032:sub<def> = COPY undef. + if (MI->isCopy() && MI->getOperand(0).getSubReg()) { + MachineOperand &MO = MI->getOperand(1); + if (MO.isUndef() || ImpDefRegs.count(MO.getReg())) { if (MO.isKill()) { LiveVariables::VarInfo& vi = lv_->getVarInfo(MO.getReg()); vi.removeKill(MI); @@ -119,7 +148,7 @@ bool ProcessImplicitDefs::runOnMachineFunction(MachineFunction &fn) { bool ChangedToImpDef = false; for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { MachineOperand& MO = MI->getOperand(i); - if (!MO.isReg() || !MO.isUse() || MO.isUndef()) + if (!MO.isReg() || (MO.isDef() && !MO.getSubReg()) || MO.isUndef()) continue; unsigned Reg = MO.getReg(); if (!Reg) @@ -127,7 +156,7 @@ bool ProcessImplicitDefs::runOnMachineFunction(MachineFunction &fn) { if (!ImpDefRegs.count(Reg)) continue; // Use is a copy, just turn it into an implicit_def. - if (CanTurnIntoImplicitDef(MI, Reg, i, tii_)) { + if (CanTurnIntoImplicitDef(MI, Reg, i, tii_, ImpDefRegs)) { bool isKill = MO.isKill(); MI->setDesc(tii_->get(TargetOpcode::IMPLICIT_DEF)); for (int j = MI->getNumOperands() - 1, ee = 0; j > ee; --j) @@ -144,6 +173,12 @@ bool ProcessImplicitDefs::runOnMachineFunction(MachineFunction &fn) { Changed = true; MO.setIsUndef(); + // This is a partial register redef of an implicit def. + // Make sure the whole register is defined by the instruction. + if (MO.isDef()) { + MI->addRegisterDefined(Reg); + continue; + } if (MO.isKill() || MI->isRegTiedToDefOperand(i)) { // Make sure other uses of for (unsigned j = i+1; j != e; ++j) { @@ -218,9 +253,7 @@ bool ProcessImplicitDefs::runOnMachineFunction(MachineFunction &fn) { MachineInstr *RMI = RUses[i]; // Turn a copy use into an implicit_def. - unsigned SrcReg, DstReg, SrcSubReg, DstSubReg; - if (tii_->isMoveInstr(*RMI, SrcReg, DstReg, SrcSubReg, DstSubReg) && - Reg == SrcReg && SrcSubReg == 0 && DstSubReg == 0) { + if (isUndefCopy(RMI, Reg, tii_, ImpDefRegs)) { RMI->setDesc(tii_->get(TargetOpcode::IMPLICIT_DEF)); bool isKill = false; |