diff options
Diffstat (limited to 'lib/CodeGen')
| -rw-r--r-- | lib/CodeGen/BranchFolding.cpp | 31 | ||||
| -rw-r--r-- | lib/CodeGen/BranchFolding.h | 2 |
2 files changed, 23 insertions, 10 deletions
diff --git a/lib/CodeGen/BranchFolding.cpp b/lib/CodeGen/BranchFolding.cpp index 4df7b46929..99090a8269 100644 --- a/lib/CodeGen/BranchFolding.cpp +++ b/lib/CodeGen/BranchFolding.cpp @@ -366,11 +366,31 @@ static unsigned ComputeCommonTailLength(MachineBasicBlock *MBB1, return TailLen; } +void BranchFolder::MaintainLiveIns(MachineBasicBlock *CurMBB, + MachineBasicBlock *NewMBB) { + if (RS) { + RS->enterBasicBlock(CurMBB); + if (!CurMBB->empty()) + RS->forward(prior(CurMBB->end())); + BitVector RegsLiveAtExit(TRI->getNumRegs()); + RS->getRegsUsed(RegsLiveAtExit, false); + for (unsigned int i = 0, e = TRI->getNumRegs(); i != e; i++) + if (RegsLiveAtExit[i]) + NewMBB->addLiveIn(i); + } +} + /// ReplaceTailWithBranchTo - Delete the instruction OldInst and everything /// after it, replacing it with an unconditional branch to NewDest. void BranchFolder::ReplaceTailWithBranchTo(MachineBasicBlock::iterator OldInst, MachineBasicBlock *NewDest) { + MachineBasicBlock *CurMBB = OldInst->getParent(); + TII->ReplaceTailWithBranchTo(OldInst, NewDest); + + // For targets that use the register scavenger, we must maintain LiveIns. + MaintainLiveIns(CurMBB, NewDest); + ++NumTailMerge; } @@ -399,16 +419,7 @@ MachineBasicBlock *BranchFolder::SplitMBBAt(MachineBasicBlock &CurMBB, NewMBB->splice(NewMBB->end(), &CurMBB, BBI1, CurMBB.end()); // For targets that use the register scavenger, we must maintain LiveIns. - if (RS) { - RS->enterBasicBlock(&CurMBB); - if (!CurMBB.empty()) - RS->forward(prior(CurMBB.end())); - BitVector RegsLiveAtExit(TRI->getNumRegs()); - RS->getRegsUsed(RegsLiveAtExit, false); - for (unsigned int i = 0, e = TRI->getNumRegs(); i != e; i++) - if (RegsLiveAtExit[i]) - NewMBB->addLiveIn(i); - } + MaintainLiveIns(&CurMBB, NewMBB); return NewMBB; } diff --git a/lib/CodeGen/BranchFolding.h b/lib/CodeGen/BranchFolding.h index 4ed42c0346..df795dfc24 100644 --- a/lib/CodeGen/BranchFolding.h +++ b/lib/CodeGen/BranchFolding.h @@ -95,6 +95,8 @@ namespace llvm { bool TailMergeBlocks(MachineFunction &MF); bool TryTailMergeBlocks(MachineBasicBlock* SuccBB, MachineBasicBlock* PredBB); + void MaintainLiveIns(MachineBasicBlock *CurMBB, + MachineBasicBlock *NewMBB); void ReplaceTailWithBranchTo(MachineBasicBlock::iterator OldInst, MachineBasicBlock *NewDest); MachineBasicBlock *SplitMBBAt(MachineBasicBlock &CurMBB, |