diff options
Diffstat (limited to 'lib/CodeGen/PHIElimination.cpp')
-rw-r--r-- | lib/CodeGen/PHIElimination.cpp | 56 |
1 files changed, 5 insertions, 51 deletions
diff --git a/lib/CodeGen/PHIElimination.cpp b/lib/CodeGen/PHIElimination.cpp index 2e30cc6..c62d179 100644 --- a/lib/CodeGen/PHIElimination.cpp +++ b/lib/CodeGen/PHIElimination.cpp @@ -287,7 +287,7 @@ void llvm::PHIElimination::LowerAtomicPHINode( // Okay, if we now know that the value is not live out of the block, we can // add a kill marker in this block saying that it kills the incoming value! - if (!ValueIsUsed && !isLiveOut(SrcReg, opBlock, *LV)) { + if (!ValueIsUsed && !LV->isLiveOut(SrcReg, opBlock)) { // In our final twist, we have to decide which instruction kills the // register. In most cases this is the copy, however, the first // terminator instruction at the end of the block may also use the value. @@ -301,8 +301,8 @@ void llvm::PHIElimination::LowerAtomicPHINode( // Check that no other terminators use values. #ifndef NDEBUG - for (MachineBasicBlock::iterator TI = next(Term); TI != opBlock.end(); - ++TI) { + for (MachineBasicBlock::iterator TI = llvm::next(Term); + TI != opBlock.end(); ++TI) { assert(!TI->readsRegister(SrcReg) && "Terminator instructions cannot use virtual registers unless" "they are the first terminator in a block!"); @@ -353,59 +353,13 @@ bool llvm::PHIElimination::SplitPHIEdges(MachineFunction &MF, // We break edges when registers are live out from the predecessor block // (not considering PHI nodes). If the register is live in to this block // anyway, we would gain nothing from splitting. - if (!LV.isLiveIn(Reg, MBB) && isLiveOut(Reg, *PreMBB, LV)) + if (!LV.isLiveIn(Reg, MBB) && LV.isLiveOut(Reg, *PreMBB)) SplitCriticalEdge(PreMBB, &MBB); } } return true; } -bool llvm::PHIElimination::isLiveOut(unsigned Reg, const MachineBasicBlock &MBB, - LiveVariables &LV) { - LiveVariables::VarInfo &VI = LV.getVarInfo(Reg); - - // Loop over all of the successors of the basic block, checking to see if - // the value is either live in the block, or if it is killed in the block. - std::vector<MachineBasicBlock*> OpSuccBlocks; - for (MachineBasicBlock::const_succ_iterator SI = MBB.succ_begin(), - E = MBB.succ_end(); SI != E; ++SI) { - MachineBasicBlock *SuccMBB = *SI; - - // Is it alive in this successor? - unsigned SuccIdx = SuccMBB->getNumber(); - if (VI.AliveBlocks.test(SuccIdx)) - return true; - OpSuccBlocks.push_back(SuccMBB); - } - - // Check to see if this value is live because there is a use in a successor - // that kills it. - switch (OpSuccBlocks.size()) { - case 1: { - MachineBasicBlock *SuccMBB = OpSuccBlocks[0]; - for (unsigned i = 0, e = VI.Kills.size(); i != e; ++i) - if (VI.Kills[i]->getParent() == SuccMBB) - return true; - break; - } - case 2: { - MachineBasicBlock *SuccMBB1 = OpSuccBlocks[0], *SuccMBB2 = OpSuccBlocks[1]; - for (unsigned i = 0, e = VI.Kills.size(); i != e; ++i) - if (VI.Kills[i]->getParent() == SuccMBB1 || - VI.Kills[i]->getParent() == SuccMBB2) - return true; - break; - } - default: - std::sort(OpSuccBlocks.begin(), OpSuccBlocks.end()); - for (unsigned i = 0, e = VI.Kills.size(); i != e; ++i) - if (std::binary_search(OpSuccBlocks.begin(), OpSuccBlocks.end(), - VI.Kills[i]->getParent())) - return true; - } - return false; -} - MachineBasicBlock *PHIElimination::SplitCriticalEdge(MachineBasicBlock *A, MachineBasicBlock *B) { assert(A && B && "Missing MBB end point"); @@ -423,7 +377,7 @@ MachineBasicBlock *PHIElimination::SplitCriticalEdge(MachineBasicBlock *A, ++NumSplits; MachineBasicBlock *NMBB = MF->CreateMachineBasicBlock(); - MF->insert(next(MachineFunction::iterator(A)), NMBB); + MF->insert(llvm::next(MachineFunction::iterator(A)), NMBB); DEBUG(errs() << "PHIElimination splitting critical edge:" " BB#" << A->getNumber() << " -- BB#" << NMBB->getNumber() |