X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FTransforms%2FUtils%2FLowerAllocations.cpp;h=8c6550003dd72b0dbe78a4c0ca89148bc83349a2;hb=cb2610ea037a17115ef3a01a6bdaab4e3cfdca27;hp=4f3f182cf32d3fffd918a7bfe9f8a52ee90d5bc4;hpb=f4de63f65fa995e68e3cd268117ab065068be413;p=oota-llvm.git diff --git a/lib/Transforms/Utils/LowerAllocations.cpp b/lib/Transforms/Utils/LowerAllocations.cpp index 4f3f182cf32..8c6550003dd 100644 --- a/lib/Transforms/Utils/LowerAllocations.cpp +++ b/lib/Transforms/Utils/LowerAllocations.cpp @@ -1,125 +1,134 @@ -//===- llvm/Transforms/LowerAllocations.h - Remove Malloc & Free Insts ------=// +//===- LowerAllocations.cpp - Reduce malloc & free insts to calls ---------===// // -// This file implements a pass that lowers malloc and free instructions to -// calls to %malloc & %free functions. This transformation is a target -// dependant tranformation because we depend on the size of data types and -// alignment constraints. +// The LowerAllocations transformation is a target dependant tranformation +// because it depends on the size of data types and alignment constraints. // //===----------------------------------------------------------------------===// -#include "llvm/Transforms/LowerAllocations.h" -#include "llvm/Target/TargetData.h" +#include "llvm/Transforms/Scalar.h" +#include "llvm/Module.h" #include "llvm/DerivedTypes.h" #include "llvm/iMemory.h" #include "llvm/iOther.h" -#include "llvm/SymbolTable.h" -#include "llvm/ConstantVals.h" +#include "llvm/Constants.h" +#include "llvm/Pass.h" +#include "llvm/Target/TargetData.h" +#include "Support/Statistic.h" + using std::vector; +namespace { + Statistic<> NumLowered("lowerallocs", "Number of allocations lowered"); + + /// LowerAllocations - Turn malloc and free instructions into %malloc and + /// %free calls. + /// + class LowerAllocations : public BasicBlockPass { + Function *MallocFunc; // Functions in the module we are processing + Function *FreeFunc; // Initialized by doInitialization + public: + LowerAllocations() : MallocFunc(0), FreeFunc(0) {} + + virtual void getAnalysisUsage(AnalysisUsage &AU) const { + AU.addRequired(); + } + + /// doPassInitialization - For the lower allocations pass, this ensures that + /// a module contains a declaration for a malloc and a free function. + /// + bool doInitialization(Module &M); + + /// runOnBasicBlock - This method does the actual work of converting + /// instructions over, assuming that the pass has already been initialized. + /// + bool runOnBasicBlock(BasicBlock &BB); + }; + + RegisterOpt + X("lowerallocs", "Lower allocations from instructions to calls"); +} + +// createLowerAllocationsPass - Interface to this file... +Pass *createLowerAllocationsPass() { + return new LowerAllocations(); +} + // doInitialization - For the lower allocations pass, this ensures that a // module contains a declaration for a malloc and a free function. // // This function is always successful. // -bool LowerAllocations::doInitialization(Module *M) { - bool Changed = false; - const MethodType *MallocType = - MethodType::get(PointerType::get(Type::SByteTy), - vector(1, Type::UIntTy), false); - - SymbolTable *SymTab = M->getSymbolTableSure(); - - // Check for a definition of malloc - if (Value *V = SymTab->lookup(PointerType::get(MallocType), "malloc")) { - MallocMeth = cast(V); // Yup, got it - } else { // Nope, add one - M->getMethodList().push_back(MallocMeth = new Method(MallocType, false, - "malloc")); - Changed = true; - } - - const MethodType *FreeType = - MethodType::get(Type::VoidTy, - vector(1, PointerType::get(Type::SByteTy)), - false); - - // Check for a definition of free - if (Value *V = SymTab->lookup(PointerType::get(FreeType), "free")) { - FreeMeth = cast(V); // Yup, got it - } else { // Nope, add one - M->getMethodList().push_back(FreeMeth = new Method(FreeType, false,"free")); - Changed = true; - } - - return Changed; // Always successful +bool LowerAllocations::doInitialization(Module &M) { + const FunctionType *MallocType = + FunctionType::get(PointerType::get(Type::SByteTy), + vector(1, Type::UIntTy), false); + const FunctionType *FreeType = + FunctionType::get(Type::VoidTy, + vector(1, PointerType::get(Type::SByteTy)), + false); + + MallocFunc = M.getOrInsertFunction("malloc", MallocType); + FreeFunc = M.getOrInsertFunction("free" , FreeType); + + return true; } -// runOnMethod - This method does the actual work of converting +// runOnBasicBlock - This method does the actual work of converting // instructions over, assuming that the pass has already been initialized. // -bool LowerAllocations::runOnMethod(Method *M) { +bool LowerAllocations::runOnBasicBlock(BasicBlock &BB) { bool Changed = false; - assert(MallocMeth && FreeMeth && M && "Pass not initialized!"); + assert(MallocFunc && FreeFunc && "Pass not initialized!"); + + BasicBlock::InstListType &BBIL = BB.getInstList(); + TargetData &DataLayout = getAnalysis(); // Loop over all of the instructions, looking for malloc or free instructions - for (Method::iterator BBI = M->begin(), BBE = M->end(); BBI != BBE; ++BBI) { - BasicBlock *BB = *BBI; - for (unsigned i = 0; i < BB->size(); ++i) { - BasicBlock::InstListType &BBIL = BB->getInstList(); - if (MallocInst *MI = dyn_cast(*(BBIL.begin()+i))) { - BBIL.remove(BBIL.begin()+i); // remove the malloc instr... - - const Type *AllocTy =cast(MI->getType())->getElementType(); - - // Get the number of bytes to be allocated for one element of the - // requested type... - unsigned Size = DataLayout.getTypeSize(AllocTy); - - // malloc(type) becomes sbyte *malloc(constint) - Value *MallocArg = ConstantUInt::get(Type::UIntTy, Size); - if (MI->getNumOperands() && Size == 1) { - MallocArg = MI->getOperand(0); // Operand * 1 = Operand - } else if (MI->getNumOperands()) { - // Multiply it by the array size if neccesary... - MallocArg = BinaryOperator::create(Instruction::Mul,MI->getOperand(0), - MallocArg); - BBIL.insert(BBIL.begin()+i++, cast(MallocArg)); - } - - // Create the call to Malloc... - CallInst *MCall = new CallInst(MallocMeth, - vector(1, MallocArg)); - BBIL.insert(BBIL.begin()+i, MCall); - - // Create a cast instruction to convert to the right type... - CastInst *MCast = new CastInst(MCall, MI->getType()); - BBIL.insert(BBIL.begin()+i+1, MCast); - - // Replace all uses of the old malloc inst with the cast inst - MI->replaceAllUsesWith(MCast); - delete MI; // Delete the malloc inst - Changed = true; - } else if (FreeInst *FI = dyn_cast(*(BBIL.begin()+i))) { - BBIL.remove(BB->getInstList().begin()+i); - - // Cast the argument to free into a ubyte*... - CastInst *MCast = new CastInst(FI->getOperand(0), - PointerType::get(Type::UByteTy)); - BBIL.insert(BBIL.begin()+i, MCast); - - // Insert a call to the free function... - CallInst *FCall = new CallInst(FreeMeth, - vector(1, MCast)); - BBIL.insert(BBIL.begin()+i+1, FCall); - - // Delete the old free instruction - delete FI; - Changed = true; + for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E; ++I) { + if (MallocInst *MI = dyn_cast(&*I)) { + const Type *AllocTy = MI->getType()->getElementType(); + + // Get the number of bytes to be allocated for one element of the + // requested type... + unsigned Size = DataLayout.getTypeSize(AllocTy); + + // malloc(type) becomes sbyte *malloc(constint) + Value *MallocArg = ConstantUInt::get(Type::UIntTy, Size); + if (MI->getNumOperands() && Size == 1) { + MallocArg = MI->getOperand(0); // Operand * 1 = Operand + } else if (MI->getNumOperands()) { + // Multiply it by the array size if neccesary... + MallocArg = BinaryOperator::create(Instruction::Mul, MI->getOperand(0), + MallocArg, "", I); } + + // Create the call to Malloc... + CallInst *MCall = new CallInst(MallocFunc, + vector(1, MallocArg), "", I); + + // Create a cast instruction to convert to the right type... + CastInst *MCast = new CastInst(MCall, MI->getType(), "", I); + + // Replace all uses of the old malloc inst with the cast inst + MI->replaceAllUsesWith(MCast); + I = --BBIL.erase(I); // remove and delete the malloc instr... + Changed = true; + ++NumLowered; + } else if (FreeInst *FI = dyn_cast(&*I)) { + // Cast the argument to free into a ubyte*... + CastInst *MCast = new CastInst(FI->getOperand(0), + PointerType::get(Type::UByteTy), "", I); + + // Insert a call to the free function... + CallInst *FCall = new CallInst(FreeFunc, vector(1, MCast), "", I); + + // Delete the old free instruction + I = --BBIL.erase(I); + Changed = true; + ++NumLowered; } } return Changed; } -