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//===-- 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 <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->abegin(), I->aend(), Type::IntTy);
break;
case Intrinsic::longjmp:
EnsureFunctionExists(M, "longjmp", I->abegin(), I->aend(),Type::VoidTy);
break;
case Intrinsic::siglongjmp:
EnsureFunctionExists(M, "abort", I->aend(), I->aend(), Type::VoidTy);
break;
case Intrinsic::memcpy:
EnsureFunctionExists(M, "memcpy", I->abegin(), --I->aend(),
I->abegin()->getType());
break;
case Intrinsic::memmove:
EnsureFunctionExists(M, "memmove", I->abegin(), --I->aend(),
I->abegin()->getType());
break;
case Intrinsic::memset:
EnsureFunctionExists(M, "memset", I->abegin(), --I->aend(),
I->abegin()->getType());
break;
case Intrinsic::isunordered:
EnsureFunctionExists(M, "isunordered", I->abegin(), I->aend(), Type::BoolTy);
break;
}
}
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::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::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: {
static Function *isunorderedFCache = 0;
ReplaceCallWith("isunordered", CI, CI->op_begin()+1, CI->op_end(),
Type::BoolTy, isunorderedFCache);
break;
}
}
assert(CI->use_empty() &&
"Lowering should have eliminated any uses of the intrinsic call!");
CI->getParent()->getInstList().erase(CI);
}
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