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Diffstat (limited to 'lib/CodeGen/IntrinsicLowering.cpp')
| -rw-r--r-- | lib/CodeGen/IntrinsicLowering.cpp | 326 |
1 files changed, 326 insertions, 0 deletions
diff --git a/lib/CodeGen/IntrinsicLowering.cpp b/lib/CodeGen/IntrinsicLowering.cpp new file mode 100644 index 0000000000..a570ef54c4 --- /dev/null +++ b/lib/CodeGen/IntrinsicLowering.cpp @@ -0,0 +1,326 @@ +//===-- 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(), + (Type *)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(); +} |