//===-- IntrinsicLowering.cpp - Intrinsic Lowering default implementation -===// // // The LLVM Compiler Infrastructure // // This file was developed by the LLVM research group and is distributed under // the University of Illinois Open Source License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file implements the default intrinsic lowering implementation. // //===----------------------------------------------------------------------===// #include "llvm/CodeGen/IntrinsicLowering.h" #include "llvm/Constants.h" #include "llvm/DerivedTypes.h" #include "llvm/Module.h" #include "llvm/Instructions.h" #include "llvm/Type.h" #include <iostream> using namespace llvm; template <class ArgIt> static Function *EnsureFunctionExists(Module &M, const char *Name, ArgIt ArgBegin, ArgIt ArgEnd, const Type *RetTy) { if (Function *F = M.getNamedFunction(Name)) return F; // It doesn't already exist in the program, insert a new definition now. std::vector<const Type *> ParamTys; for (ArgIt I = ArgBegin; I != ArgEnd; ++I) ParamTys.push_back(I->getType()); return M.getOrInsertFunction(Name, FunctionType::get(RetTy, ParamTys, false)); } /// ReplaceCallWith - This function is used when we want to lower an intrinsic /// call to a call of an external function. This handles hard cases such as /// when there was already a prototype for the external function, and if that /// prototype doesn't match the arguments we expect to pass in. template <class ArgIt> static CallInst *ReplaceCallWith(const char *NewFn, CallInst *CI, ArgIt ArgBegin, ArgIt ArgEnd, const Type *RetTy, Function *&FCache) { if (!FCache) { // If we haven't already looked up this function, check to see if the // program already contains a function with this name. Module *M = CI->getParent()->getParent()->getParent(); FCache = M->getNamedFunction(NewFn); if (!FCache) { // It doesn't already exist in the program, insert a new definition now. std::vector<const Type *> ParamTys; for (ArgIt I = ArgBegin; I != ArgEnd; ++I) ParamTys.push_back((*I)->getType()); FCache = M->getOrInsertFunction(NewFn, FunctionType::get(RetTy, ParamTys, false)); } } const FunctionType *FT = FCache->getFunctionType(); std::vector<Value*> Operands; unsigned ArgNo = 0; for (ArgIt I = ArgBegin; I != ArgEnd && ArgNo != FT->getNumParams(); ++I, ++ArgNo) { Value *Arg = *I; if (Arg->getType() != FT->getParamType(ArgNo)) Arg = new CastInst(Arg, FT->getParamType(ArgNo), Arg->getName(), CI); Operands.push_back(Arg); } // Pass nulls into any additional arguments... for (; ArgNo != FT->getNumParams(); ++ArgNo) Operands.push_back(Constant::getNullValue(FT->getParamType(ArgNo))); std::string Name = CI->getName(); CI->setName(""); if (FT->getReturnType() == Type::VoidTy) Name.clear(); CallInst *NewCI = new CallInst(FCache, Operands, Name, CI); if (!CI->use_empty()) { Value *V = NewCI; if (CI->getType() != NewCI->getType()) V = new CastInst(NewCI, CI->getType(), Name, CI); CI->replaceAllUsesWith(V); } return NewCI; } void DefaultIntrinsicLowering::AddPrototypes(Module &M) { for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) if (I->isExternal() && !I->use_empty()) switch (I->getIntrinsicID()) { default: break; case Intrinsic::setjmp: EnsureFunctionExists(M, "setjmp", I->arg_begin(), I->arg_end(), Type::IntTy); break; case Intrinsic::longjmp: EnsureFunctionExists(M, "longjmp", I->arg_begin(), I->arg_end(), Type::VoidTy); break; case Intrinsic::siglongjmp: EnsureFunctionExists(M, "abort", I->arg_end(), I->arg_end(), Type::VoidTy); break; case Intrinsic::memcpy: EnsureFunctionExists(M, "memcpy", I->arg_begin(), --I->arg_end(), I->arg_begin()->getType()); break; case Intrinsic::memmove: EnsureFunctionExists(M, "memmove", I->arg_begin(), --I->arg_end(), I->arg_begin()->getType()); break; case Intrinsic::memset: M.getOrInsertFunction("memset", PointerType::get(Type::SByteTy), PointerType::get(Type::SByteTy), Type::IntTy, (--(--I->arg_end()))->getType(), 0); break; case Intrinsic::isunordered: EnsureFunctionExists(M, "isunordered", I->arg_begin(), I->arg_end(), Type::BoolTy); break; case Intrinsic::sqrt: if(I->arg_begin()->getType() == Type::FloatTy) EnsureFunctionExists(M, "sqrtf", I->arg_begin(), I->arg_end(), Type::FloatTy); else EnsureFunctionExists(M, "sqrt", I->arg_begin(), I->arg_end(), Type::DoubleTy); break; } } /// LowerCTPOP - Emit the code to lower ctpop of V before the specified /// instruction. static Value *LowerCTPOP(Value *V, Instruction *IP) { assert(V->getType()->isInteger() && "Can't ctpop a non-integer type!"); static const uint64_t MaskValues[6] = { 0x5555555555555555ULL, 0x3333333333333333ULL, 0x0F0F0F0F0F0F0F0FULL, 0x00FF00FF00FF00FFULL, 0x0000FFFF0000FFFFULL, 0x00000000FFFFFFFFULL }; const Type *DestTy = V->getType(); // Force to unsigned so that the shift rights are logical. if (DestTy->isSigned()) V = new CastInst(V, DestTy->getUnsignedVersion(), V->getName(), IP); unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); for (unsigned i = 1, ct = 0; i != BitSize; i <<= 1, ++ct) { Value *MaskCst = ConstantExpr::getCast(ConstantUInt::get(Type::ULongTy, MaskValues[ct]), V->getType()); Value *LHS = BinaryOperator::createAnd(V, MaskCst, "cppop.and1", IP); Value *VShift = new ShiftInst(Instruction::Shr, V, ConstantInt::get(Type::UByteTy, i), "ctpop.sh", IP); Value *RHS = BinaryOperator::createAnd(VShift, MaskCst, "cppop.and2", IP); V = BinaryOperator::createAdd(LHS, RHS, "ctpop.step", IP); } if (V->getType() != DestTy) V = new CastInst(V, DestTy, V->getName(), IP); return V; } /// LowerCTLZ - Emit the code to lower ctlz of V before the specified /// instruction. static Value *LowerCTLZ(Value *V, Instruction *IP) { const Type *DestTy = V->getType(); // Force to unsigned so that the shift rights are logical. if (DestTy->isSigned()) V = new CastInst(V, DestTy->getUnsignedVersion(), V->getName(), IP); unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); for (unsigned i = 1; i != BitSize; i <<= 1) { Value *ShVal = ConstantInt::get(Type::UByteTy, i); ShVal = new ShiftInst(Instruction::Shr, V, ShVal, "ctlz.sh", IP); V = BinaryOperator::createOr(V, ShVal, "ctlz.step", IP); } if (V->getType() != DestTy) V = new CastInst(V, DestTy, V->getName(), IP); V = BinaryOperator::createNot(V, "", IP); return LowerCTPOP(V, IP); } void DefaultIntrinsicLowering::LowerIntrinsicCall(CallInst *CI) { Function *Callee = CI->getCalledFunction(); assert(Callee && "Cannot lower an indirect call!"); switch (Callee->getIntrinsicID()) { case Intrinsic::not_intrinsic: std::cerr << "Cannot lower a call to a non-intrinsic function '" << Callee->getName() << "'!\n"; abort(); default: std::cerr << "Error: Code generator does not support intrinsic function '" << Callee->getName() << "'!\n"; abort(); // The setjmp/longjmp intrinsics should only exist in the code if it was // never optimized (ie, right out of the CFE), or if it has been hacked on // by the lowerinvoke pass. In both cases, the right thing to do is to // convert the call to an explicit setjmp or longjmp call. case Intrinsic::setjmp: { static Function *SetjmpFCache = 0; Value *V = ReplaceCallWith("setjmp", CI, CI->op_begin()+1, CI->op_end(), Type::IntTy, SetjmpFCache); if (CI->getType() != Type::VoidTy) CI->replaceAllUsesWith(V); break; } case Intrinsic::sigsetjmp: if (CI->getType() != Type::VoidTy) CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); break; case Intrinsic::longjmp: { static Function *LongjmpFCache = 0; ReplaceCallWith("longjmp", CI, CI->op_begin()+1, CI->op_end(), Type::VoidTy, LongjmpFCache); break; } case Intrinsic::siglongjmp: { // Insert the call to abort static Function *AbortFCache = 0; ReplaceCallWith("abort", CI, CI->op_end(), CI->op_end(), Type::VoidTy, AbortFCache); break; } case Intrinsic::ctpop: CI->replaceAllUsesWith(LowerCTPOP(CI->getOperand(1), CI)); break; case Intrinsic::ctlz: CI->replaceAllUsesWith(LowerCTLZ(CI->getOperand(1), CI)); break; case Intrinsic::cttz: { // cttz(x) -> ctpop(~X & (X-1)) Value *Src = CI->getOperand(1); Value *NotSrc = BinaryOperator::createNot(Src, Src->getName()+".not", CI); Value *SrcM1 = ConstantInt::get(Src->getType(), 1); SrcM1 = BinaryOperator::createSub(Src, SrcM1, "", CI); Src = LowerCTPOP(BinaryOperator::createAnd(NotSrc, SrcM1, "", CI), CI); CI->replaceAllUsesWith(Src); break; } case Intrinsic::returnaddress: case Intrinsic::frameaddress: std::cerr << "WARNING: this target does not support the llvm." << (Callee->getIntrinsicID() == Intrinsic::returnaddress ? "return" : "frame") << "address intrinsic.\n"; CI->replaceAllUsesWith(ConstantPointerNull::get( cast<PointerType>(CI->getType()))); break; case Intrinsic::prefetch: break; // Simply strip out prefetches on unsupported architectures case Intrinsic::pcmarker: break; // Simply strip out pcmarker on unsupported architectures case Intrinsic::dbg_stoppoint: case Intrinsic::dbg_region_start: case Intrinsic::dbg_region_end: case Intrinsic::dbg_declare: case Intrinsic::dbg_func_start: if (CI->getType() != Type::VoidTy) CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); break; // Simply strip out debugging intrinsics case Intrinsic::memcpy: { // The memcpy intrinsic take an extra alignment argument that the memcpy // libc function does not. static Function *MemcpyFCache = 0; ReplaceCallWith("memcpy", CI, CI->op_begin()+1, CI->op_end()-1, (*(CI->op_begin()+1))->getType(), MemcpyFCache); break; } case Intrinsic::memmove: { // The memmove intrinsic take an extra alignment argument that the memmove // libc function does not. static Function *MemmoveFCache = 0; ReplaceCallWith("memmove", CI, CI->op_begin()+1, CI->op_end()-1, (*(CI->op_begin()+1))->getType(), MemmoveFCache); break; } case Intrinsic::memset: { // The memset intrinsic take an extra alignment argument that the memset // libc function does not. static Function *MemsetFCache = 0; ReplaceCallWith("memset", CI, CI->op_begin()+1, CI->op_end()-1, (*(CI->op_begin()+1))->getType(), MemsetFCache); break; } case Intrinsic::isunordered: { Value *L = CI->getOperand(1); Value *R = CI->getOperand(2); Value *LIsNan = new SetCondInst(Instruction::SetNE, L, L, "LIsNan", CI); Value *RIsNan = new SetCondInst(Instruction::SetNE, R, R, "RIsNan", CI); CI->replaceAllUsesWith( BinaryOperator::create(Instruction::Or, LIsNan, RIsNan, "isunordered", CI)); break; } case Intrinsic::sqrt: { static Function *sqrtFCache = 0; static Function *sqrtfFCache = 0; if(CI->getType() == Type::FloatTy) ReplaceCallWith("sqrtf", CI, CI->op_begin()+1, CI->op_end(), Type::FloatTy, sqrtfFCache); else ReplaceCallWith("sqrt", CI, CI->op_begin()+1, CI->op_end(), Type::DoubleTy, sqrtFCache); break; } } assert(CI->use_empty() && "Lowering should have eliminated any uses of the intrinsic call!"); CI->eraseFromParent(); }