X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FTransforms%2FUtils%2FLowerAllocations.cpp;h=003be33182a8c36614649e70e09983febe70e546;hb=56d27019e6aebd7cfa5d031c832193eb66d75830;hp=91f45d8206957138883b5ae1353f9b3735b463a5;hpb=7ef6559718a18a20349d41c28b89bb8cbc1f1022;p=oota-llvm.git diff --git a/lib/Transforms/Utils/LowerAllocations.cpp b/lib/Transforms/Utils/LowerAllocations.cpp index 91f45d82069..003be33182a 100644 --- a/lib/Transforms/Utils/LowerAllocations.cpp +++ b/lib/Transforms/Utils/LowerAllocations.cpp @@ -1,127 +1,144 @@ -//===- 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/ChangeAllocations.h" +#include "llvm/Module.h" +#include "llvm/Function.h" +#include "llvm/BasicBlock.h" #include "llvm/DerivedTypes.h" #include "llvm/iMemory.h" #include "llvm/iOther.h" -#include "llvm/SymbolTable.h" +#include "llvm/Constants.h" +#include "llvm/Pass.h" +#include "llvm/Target/TargetData.h" +#include "Support/StatisticReporter.h" -// doPassInitialization - 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. +static Statistic<> NumLowered("lowerallocs\t- Number of allocations lowered"); +using std::vector; + +namespace { + +// LowerAllocations - Turn malloc and free instructions into %malloc and %free +// calls. // -bool LowerAllocations::doPassInitialization(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, "malloc")); - Changed = true; +class LowerAllocations : public BasicBlockPass { + Function *MallocFunc; // Functions in the module we are processing + Function *FreeFunc; // Initialized by doInitialization + + const TargetData &DataLayout; +public: + inline LowerAllocations(const TargetData &TD) : DataLayout(TD) { + MallocFunc = FreeFunc = 0; } - 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, "free")); - Changed = true; - } + const char *getPassName() const { return "Lower Allocations"; } + + // 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); +}; - return Changed; // Always successful } -// doPerMethodWork - This method does the actual work of converting +// createLowerAllocationsPass - Interface to this file... +Pass *createLowerAllocationsPass(const TargetData &TD) { + return new LowerAllocations(TD); +} + + +// 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) { + 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; +} + +// runOnBasicBlock - This method does the actual work of converting // instructions over, assuming that the pass has already been initialized. // -bool LowerAllocations::doPerMethodWork(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(); // 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())->getValueType(); - - // If the user is allocating an unsized array with a dynamic size arg, - // start by getting the size of one element. - // - if (const ArrayType *ATy = dyn_cast(AllocTy)) - if (ATy->isUnsized()) AllocTy = ATy->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 = ConstPoolUInt::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)) { + BBIL.remove(I); // remove the malloc instr... + + 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 = ++BBIL.insert(I, cast(MallocArg)); } + + // Create the call to Malloc... + CallInst *MCall = new CallInst(MallocFunc, + vector(1, MallocArg)); + I = BBIL.insert(I, MCall); + + // Create a cast instruction to convert to the right type... + CastInst *MCast = new CastInst(MCall, MI->getType()); + I = BBIL.insert(++I, MCast); + + // Replace all uses of the old malloc inst with the cast inst + MI->replaceAllUsesWith(MCast); + delete MI; // Delete the malloc inst + Changed = true; + ++NumLowered; + } else if (FreeInst *FI = dyn_cast(&*I)) { + BBIL.remove(I); + + // Cast the argument to free into a ubyte*... + CastInst *MCast = new CastInst(FI->getOperand(0), + PointerType::get(Type::UByteTy)); + I = ++BBIL.insert(I, MCast); + + // Insert a call to the free function... + CallInst *FCall = new CallInst(FreeFunc, vector(1, MCast)); + I = BBIL.insert(I, FCall); + + // Delete the old free instruction + delete FI; + Changed = true; + ++NumLowered; } } return Changed; } -