diff options
Diffstat (limited to 'lib/CodeGen/ProcessImplicitDefs.cpp')
| -rw-r--r-- | lib/CodeGen/ProcessImplicitDefs.cpp | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/lib/CodeGen/ProcessImplicitDefs.cpp b/lib/CodeGen/ProcessImplicitDefs.cpp index 0195918a11..80121ca0f2 100644 --- a/lib/CodeGen/ProcessImplicitDefs.cpp +++ b/lib/CodeGen/ProcessImplicitDefs.cpp @@ -117,10 +117,24 @@ bool ProcessImplicitDefs::runOnMachineFunction(MachineFunction &fn) { } } + // Eliminate %reg1032:sub<def> = COPY undef. + if (MI->isCopy() && MI->getOperand(0).getSubReg()) { + MachineOperand &MO = MI->getOperand(1); + if (ImpDefRegs.count(MO.getReg())) { + if (MO.isKill()) { + LiveVariables::VarInfo& vi = lv_->getVarInfo(MO.getReg()); + vi.removeKill(MI); + } + MI->eraseFromParent(); + Changed = true; + continue; + } + } + 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) @@ -145,6 +159,12 @@ 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) { |