diff options
Diffstat (limited to 'lib/CodeGen/LiveVariables.cpp')
| -rw-r--r-- | lib/CodeGen/LiveVariables.cpp | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/lib/CodeGen/LiveVariables.cpp b/lib/CodeGen/LiveVariables.cpp index 7477d91930..96d36c8e56 100644 --- a/lib/CodeGen/LiveVariables.cpp +++ b/lib/CodeGen/LiveVariables.cpp @@ -261,12 +261,11 @@ void LiveVariables::HandlePhysRegUse(unsigned Reg, MachineInstr *MI) { Processed.insert(*SS); } } - } - else if (LastDef && !PhysRegUse[Reg] && - !LastDef->findRegisterDefOperand(Reg)) + } else if (LastDef && !PhysRegUse[Reg] && + !LastDef->findRegisterDefOperand(Reg)) // Last def defines the super register, add an implicit def of reg. - LastDef->addOperand(MachineOperand::CreateReg(Reg, - true/*IsDef*/, true/*IsImp*/)); + LastDef->addOperand(MachineOperand::CreateReg(Reg, true/*IsDef*/, + true/*IsImp*/)); // Remember this use. PhysRegUse[Reg] = MI; @@ -607,10 +606,27 @@ bool LiveVariables::runOnMachineFunction(MachineFunction &mf) { } } + // MachineCSE may CSE instructions which write to non-allocatable physical + // registers across MBBs. Remember if any reserved register is liveout. + SmallSet<unsigned, 4> LiveOuts; + for (MachineBasicBlock::const_succ_iterator SI = MBB->succ_begin(), + SE = MBB->succ_end(); SI != SE; ++SI) { + MachineBasicBlock *SuccMBB = *SI; + if (SuccMBB->isLandingPad()) + continue; + for (MachineBasicBlock::livein_iterator LI = SuccMBB->livein_begin(), + LE = SuccMBB->livein_end(); LI != LE; ++LI) { + unsigned LReg = *LI; + if (!TRI->isInAllocatableClass(LReg)) + // Ignore other live-ins, e.g. those that are live into landing pads. + LiveOuts.insert(LReg); + } + } + // Loop over PhysRegDef / PhysRegUse, killing any registers that are // available at the end of the basic block. for (unsigned i = 0; i != NumRegs; ++i) - if (PhysRegDef[i] || PhysRegUse[i]) + if ((PhysRegDef[i] || PhysRegUse[i]) && !LiveOuts.count(i)) HandlePhysRegDef(i, 0, Defs); std::fill(PhysRegDef, PhysRegDef + NumRegs, (MachineInstr*)0); |