diff options
Diffstat (limited to 'lib/CodeGen/MachineCSE.cpp')
-rw-r--r-- | lib/CodeGen/MachineCSE.cpp | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/lib/CodeGen/MachineCSE.cpp b/lib/CodeGen/MachineCSE.cpp index 3a60a37..7eda8c1 100644 --- a/lib/CodeGen/MachineCSE.cpp +++ b/lib/CodeGen/MachineCSE.cpp @@ -430,13 +430,24 @@ bool MachineCSE::ProcessBlock(MachineBasicBlock *MBB) { unsigned NewReg = CSMI->getOperand(i).getReg(); if (OldReg == NewReg) continue; + assert(TargetRegisterInfo::isVirtualRegister(OldReg) && TargetRegisterInfo::isVirtualRegister(NewReg) && "Do not CSE physical register defs!"); + if (!isProfitableToCSE(NewReg, OldReg, CSMI, MI)) { DoCSE = false; break; } + + // Don't perform CSE if the result of the old instruction cannot exist + // within the register class of the new instruction. + const TargetRegisterClass *OldRC = MRI->getRegClass(OldReg); + if (!MRI->constrainRegClass(NewReg, OldRC)) { + DoCSE = false; + break; + } + CSEPairs.push_back(std::make_pair(OldReg, NewReg)); --NumDefs; } |