diff options
| -rw-r--r-- | lib/Transforms/Utils/PromoteMemoryToRegister.cpp | 56 |
1 files changed, 35 insertions, 21 deletions
diff --git a/lib/Transforms/Utils/PromoteMemoryToRegister.cpp b/lib/Transforms/Utils/PromoteMemoryToRegister.cpp index 9baa197..cdccde3 100644 --- a/lib/Transforms/Utils/PromoteMemoryToRegister.cpp +++ b/lib/Transforms/Utils/PromoteMemoryToRegister.cpp @@ -801,6 +801,7 @@ bool PromoteMem2Reg::QueuePhiNode(BasicBlock *BB, unsigned AllocaNo, void PromoteMem2Reg::RenamePass(BasicBlock *BB, BasicBlock *Pred, RenamePassData::ValVector &IncomingVals, std::vector<RenamePassData> &Worklist) { +NextIteration: // If we are inserting any phi nodes into this BB, they will already be in the // block. if (PHINode *APN = dyn_cast<PHINode>(BB->begin())) { @@ -865,36 +866,49 @@ void PromoteMem2Reg::RenamePass(BasicBlock *BB, BasicBlock *Pred, Instruction *I = II++; // get the instruction, increment iterator if (LoadInst *LI = dyn_cast<LoadInst>(I)) { - if (AllocaInst *Src = dyn_cast<AllocaInst>(LI->getPointerOperand())) { - std::map<AllocaInst*, unsigned>::iterator AI = AllocaLookup.find(Src); - if (AI != AllocaLookup.end()) { - Value *V = IncomingVals[AI->second]; + AllocaInst *Src = dyn_cast<AllocaInst>(LI->getPointerOperand()); + if (!Src) continue; + + std::map<AllocaInst*, unsigned>::iterator AI = AllocaLookup.find(Src); + if (AI == AllocaLookup.end()) continue; - // walk the use list of this load and replace all uses with r - LI->replaceAllUsesWith(V); - if (AST && isa<PointerType>(LI->getType())) - AST->deleteValue(LI); - BB->getInstList().erase(LI); - } - } + Value *V = IncomingVals[AI->second]; + + // Anything using the load now uses the current value. + LI->replaceAllUsesWith(V); + if (AST && isa<PointerType>(LI->getType())) + AST->deleteValue(LI); + BB->getInstList().erase(LI); } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) { // Delete this instruction and mark the name as the current holder of the // value - if (AllocaInst *Dest = dyn_cast<AllocaInst>(SI->getPointerOperand())) { - std::map<AllocaInst *, unsigned>::iterator ai = AllocaLookup.find(Dest); - if (ai != AllocaLookup.end()) { - // what value were we writing? - IncomingVals[ai->second] = SI->getOperand(0); - BB->getInstList().erase(SI); - } - } + AllocaInst *Dest = dyn_cast<AllocaInst>(SI->getPointerOperand()); + if (!Dest) continue; + + std::map<AllocaInst *, unsigned>::iterator ai = AllocaLookup.find(Dest); + if (ai == AllocaLookup.end()) + continue; + + // what value were we writing? + IncomingVals[ai->second] = SI->getOperand(0); + BB->getInstList().erase(SI); } } - // Recurse to our successors. + // 'Recurse' to our successors. TerminatorInst *TI = BB->getTerminator(); - for (unsigned i = 0; i != TI->getNumSuccessors(); i++) + unsigned NumSuccs = TI->getNumSuccessors(); + if (NumSuccs == 0) return; + + // Add all-but-one successor to the worklist. + for (unsigned i = 0; i != NumSuccs-1; i++) Worklist.push_back(RenamePassData(TI->getSuccessor(i), BB, IncomingVals)); + + // Handle the last successor without using the worklist. This allows us to + // handle unconditional branches directly, for example. + Pred = BB; + BB = TI->getSuccessor(NumSuccs-1); + goto NextIteration; } /// PromoteMemToReg - Promote the specified list of alloca instructions into |