diff --git a/llvm/lib/Transforms/Scalar/Reg2Mem.cpp b/llvm/lib/Transforms/Scalar/Reg2Mem.cpp index 23d6ff500558..99e12522ce0c 100644 --- a/llvm/lib/Transforms/Scalar/Reg2Mem.cpp +++ b/llvm/lib/Transforms/Scalar/Reg2Mem.cpp @@ -43,74 +43,17 @@ namespace { AU.addPreservedID(BreakCriticalEdgesID); } - bool valueEscapes(Instruction* i) { - BasicBlock* bb = i->getParent(); - for (Value::use_iterator ii = i->use_begin(), ie = i->use_end(); - ii != ie; ++ii) - if (cast(*ii)->getParent() != bb || - isa(*ii)) + bool valueEscapes(const Instruction *Inst) const { + const BasicBlock *BB = Inst->getParent(); + for (Value::use_const_iterator UI = Inst->use_begin(),E = Inst->use_end(); + UI != E; ++UI) + if (cast(*UI)->getParent() != BB || + isa(*UI)) return true; return false; } - virtual bool runOnFunction(Function &F) { - if (!F.isDeclaration()) { - // Insert all new allocas into entry block. - BasicBlock* BBEntry = &F.getEntryBlock(); - assert(pred_begin(BBEntry) == pred_end(BBEntry) && - "Entry block to function must not have predecessors!"); - - // Find first non-alloca instruction and create insertion point. This is - // safe if block is well-formed: it always have terminator, otherwise - // we'll get and assertion. - BasicBlock::iterator I = BBEntry->begin(); - while (isa(I)) ++I; - - CastInst *AllocaInsertionPoint = - CastInst::Create(Instruction::BitCast, - Constant::getNullValue(Type::getInt32Ty(F.getContext())), - Type::getInt32Ty(F.getContext()), - "reg2mem alloca point", I); - - // Find the escaped instructions. But don't create stack slots for - // allocas in entry block. - std::list worklist; - for (Function::iterator ibb = F.begin(), ibe = F.end(); - ibb != ibe; ++ibb) - for (BasicBlock::iterator iib = ibb->begin(), iie = ibb->end(); - iib != iie; ++iib) { - if (!(isa(iib) && iib->getParent() == BBEntry) && - valueEscapes(iib)) { - worklist.push_front(&*iib); - } - } - - // Demote escaped instructions - NumRegsDemoted += worklist.size(); - for (std::list::iterator ilb = worklist.begin(), - ile = worklist.end(); ilb != ile; ++ilb) - DemoteRegToStack(**ilb, false, AllocaInsertionPoint); - - worklist.clear(); - - // Find all phi's - for (Function::iterator ibb = F.begin(), ibe = F.end(); - ibb != ibe; ++ibb) - for (BasicBlock::iterator iib = ibb->begin(), iie = ibb->end(); - iib != iie; ++iib) - if (isa(iib)) - worklist.push_front(&*iib); - - // Demote phi nodes - NumPhisDemoted += worklist.size(); - for (std::list::iterator ilb = worklist.begin(), - ile = worklist.end(); ilb != ile; ++ilb) - DemotePHIToStack(cast(*ilb), AllocaInsertionPoint); - - return true; - } - return false; - } + virtual bool runOnFunction(Function &F); }; } @@ -118,6 +61,66 @@ char RegToMem::ID = 0; static RegisterPass X("reg2mem", "Demote all values to stack slots"); + +bool RegToMem::runOnFunction(Function &F) { + if (F.isDeclaration()) + return false; + + // Insert all new allocas into entry block. + BasicBlock *BBEntry = &F.getEntryBlock(); + assert(pred_begin(BBEntry) == pred_end(BBEntry) && + "Entry block to function must not have predecessors!"); + + // Find first non-alloca instruction and create insertion point. This is + // safe if block is well-formed: it always have terminator, otherwise + // we'll get and assertion. + BasicBlock::iterator I = BBEntry->begin(); + while (isa(I)) ++I; + + CastInst *AllocaInsertionPoint = + new BitCastInst(Constant::getNullValue(Type::getInt32Ty(F.getContext())), + Type::getInt32Ty(F.getContext()), + "reg2mem alloca point", I); + + // Find the escaped instructions. But don't create stack slots for + // allocas in entry block. + std::list WorkList; + for (Function::iterator ibb = F.begin(), ibe = F.end(); + ibb != ibe; ++ibb) + for (BasicBlock::iterator iib = ibb->begin(), iie = ibb->end(); + iib != iie; ++iib) { + if (!(isa(iib) && iib->getParent() == BBEntry) && + valueEscapes(iib)) { + WorkList.push_front(&*iib); + } + } + + // Demote escaped instructions + NumRegsDemoted += WorkList.size(); + for (std::list::iterator ilb = WorkList.begin(), + ile = WorkList.end(); ilb != ile; ++ilb) + DemoteRegToStack(**ilb, false, AllocaInsertionPoint); + + WorkList.clear(); + + // Find all phi's + for (Function::iterator ibb = F.begin(), ibe = F.end(); + ibb != ibe; ++ibb) + for (BasicBlock::iterator iib = ibb->begin(), iie = ibb->end(); + iib != iie; ++iib) + if (isa(iib)) + WorkList.push_front(&*iib); + + // Demote phi nodes + NumPhisDemoted += WorkList.size(); + for (std::list::iterator ilb = WorkList.begin(), + ile = WorkList.end(); ilb != ile; ++ilb) + DemotePHIToStack(cast(*ilb), AllocaInsertionPoint); + + return true; +} + + // createDemoteRegisterToMemory - Provide an entry point to create this pass. // const PassInfo *const llvm::DemoteRegisterToMemoryID = &X;