llvm/lib/CodeGen/IntrinsicLowering.cpp
Andrew Lenharth 691ef2ba06 Implement count leading zeros (ctlz), count trailing zeros (cttz), and count
population (ctpop).  Generic lowering is implemented, however only promotion
is implemented for SelectionDAG at the moment.

More coming soon.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21676 91177308-0d34-0410-b5e6-96231b3b80d8
2005-05-03 17:19:30 +00:00

440 lines
19 KiB
C++

//===-- 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:
EnsureFunctionExists(M, "memset", I->arg_begin(), --I->arg_end(),
I->arg_begin()->getType());
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;
}
}
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: {
Value *Src = CI->getOperand(1);
switch (CI->getOperand(0)->getType()->getTypeID())
{
case Type::SByteTyID:
case Type::UByteTyID:
{
Value* SA = ConstantUInt::get(Type::UByteTy, 1);
Value* MA = ConstantUInt::get(Type::UIntTy, 0x55);
Src = BinaryOperator::create(Instruction::Add,
BinaryOperator::create(Instruction::And, Src, MA),
BinaryOperator::create(Instruction::And,
new ShiftInst(Instruction::Shr, Src, SA),
MA));
SA = ConstantUInt::get(Type::UByteTy, 2);
MA = ConstantUInt::get(Type::UIntTy, 0x33);
Src = BinaryOperator::create(Instruction::Add,
BinaryOperator::create(Instruction::And, Src, MA),
BinaryOperator::create(Instruction::And,
new ShiftInst(Instruction::Shr, Src, SA),
MA));
SA = ConstantUInt::get(Type::UByteTy, 4);
MA = ConstantUInt::get(Type::UIntTy, 0x0F);
Src = BinaryOperator::create(Instruction::Add,
BinaryOperator::create(Instruction::And, Src, MA),
BinaryOperator::create(Instruction::And,
new ShiftInst(Instruction::Shr, Src, SA),
MA), "ctpop");
}
break;
case Type::ShortTyID:
case Type::UShortTyID:
{
Value* SA = ConstantUInt::get(Type::UByteTy, 1);
Value* MA = ConstantUInt::get(Type::UIntTy, 0x5555);
Src = BinaryOperator::create(Instruction::Add,
BinaryOperator::create(Instruction::And, Src, MA),
BinaryOperator::create(Instruction::And,
new ShiftInst(Instruction::Shr, Src, SA),
MA));
SA = ConstantUInt::get(Type::UByteTy, 2);
MA = ConstantUInt::get(Type::UIntTy, 0x3333);
Src = BinaryOperator::create(Instruction::Add,
BinaryOperator::create(Instruction::And, Src, MA),
BinaryOperator::create(Instruction::And,
new ShiftInst(Instruction::Shr, Src, SA),
MA));
SA = ConstantUInt::get(Type::UByteTy, 4);
MA = ConstantUInt::get(Type::UIntTy, 0x0F0F);
Src = BinaryOperator::create(Instruction::Add,
BinaryOperator::create(Instruction::And, Src, MA),
BinaryOperator::create(Instruction::And,
new ShiftInst(Instruction::Shr, Src, SA),
MA));
SA = ConstantUInt::get(Type::UByteTy, 8);
MA = ConstantUInt::get(Type::UIntTy, 0x00FF);
Src = BinaryOperator::create(Instruction::Add,
BinaryOperator::create(Instruction::And, Src, MA),
BinaryOperator::create(Instruction::And,
new ShiftInst(Instruction::Shr, Src, SA),
MA), "ctpop");
}
break;
case Type::IntTyID:
case Type::UIntTyID:
{
Value* SA = ConstantUInt::get(Type::UByteTy, 1);
Value* MA = ConstantUInt::get(Type::UIntTy, 0x55555555);
Src = BinaryOperator::create(Instruction::Add,
BinaryOperator::create(Instruction::And, Src, MA),
BinaryOperator::create(Instruction::And,
new ShiftInst(Instruction::Shr, Src, SA),
MA));
SA = ConstantUInt::get(Type::UByteTy, 2);
MA = ConstantUInt::get(Type::UIntTy, 0x33333333);
Src = BinaryOperator::create(Instruction::Add,
BinaryOperator::create(Instruction::And, Src, MA),
BinaryOperator::create(Instruction::And,
new ShiftInst(Instruction::Shr, Src, SA),
MA));
SA = ConstantUInt::get(Type::UByteTy, 4);
MA = ConstantUInt::get(Type::UIntTy, 0x0F0F0F0F);
Src = BinaryOperator::create(Instruction::Add,
BinaryOperator::create(Instruction::And, Src, MA),
BinaryOperator::create(Instruction::And,
new ShiftInst(Instruction::Shr, Src, SA),
MA));
SA = ConstantUInt::get(Type::UByteTy, 8);
MA = ConstantUInt::get(Type::UIntTy, 0x00FF00FF);
Src = BinaryOperator::create(Instruction::Add,
BinaryOperator::create(Instruction::And, Src, MA),
BinaryOperator::create(Instruction::And,
new ShiftInst(Instruction::Shr, Src, SA),
MA));
SA = ConstantUInt::get(Type::UByteTy, 8);
MA = ConstantUInt::get(Type::UIntTy, 0x0000FFFF);
Src = BinaryOperator::create(Instruction::Add,
BinaryOperator::create(Instruction::And, Src, MA),
BinaryOperator::create(Instruction::And,
new ShiftInst(Instruction::Shr, Src, SA),
MA), "ctpop");
}
break;
case Type::LongTyID:
case Type::ULongTyID:
{
Value* SA = ConstantUInt::get(Type::UByteTy, 1);
Value* MA = ConstantUInt::get(Type::ULongTy, 0x5555555555555555ULL);
Src = BinaryOperator::create(Instruction::Add,
BinaryOperator::create(Instruction::And, Src, MA),
BinaryOperator::create(Instruction::And,
new ShiftInst(Instruction::Shr, Src, SA),
MA));
SA = ConstantUInt::get(Type::UByteTy, 2);
MA = ConstantUInt::get(Type::ULongTy, 0x3333333333333333ULL);
Src = BinaryOperator::create(Instruction::Add,
BinaryOperator::create(Instruction::And, Src, MA),
BinaryOperator::create(Instruction::And,
new ShiftInst(Instruction::Shr, Src, SA),
MA));
SA = ConstantUInt::get(Type::UByteTy, 4);
MA = ConstantUInt::get(Type::ULongTy, 0x0F0F0F0F0F0F0F0FULL);
Src = BinaryOperator::create(Instruction::Add,
BinaryOperator::create(Instruction::And, Src, MA),
BinaryOperator::create(Instruction::And,
new ShiftInst(Instruction::Shr, Src, SA),
MA));
SA = ConstantUInt::get(Type::UByteTy, 8);
MA = ConstantUInt::get(Type::ULongTy, 0x00FF00FF00FF00FFULL);
Src = BinaryOperator::create(Instruction::Add,
BinaryOperator::create(Instruction::And, Src, MA),
BinaryOperator::create(Instruction::And,
new ShiftInst(Instruction::Shr, Src, SA),
MA));
SA = ConstantUInt::get(Type::UByteTy, 16);
MA = ConstantUInt::get(Type::ULongTy, 0x00000000FFFFFFFFULL);
Src = BinaryOperator::create(Instruction::Add,
BinaryOperator::create(Instruction::And, Src, MA),
BinaryOperator::create(Instruction::And,
new ShiftInst(Instruction::Shr, Src, SA),
MA), "ctpop");
}
break;
default:
abort();
}
CI->replaceAllUsesWith(Src);
break;
}
case Intrinsic::ctlz: {
Value *Src = CI->getOperand(1);
Value* SA;
switch (CI->getOperand(0)->getType()->getTypeID())
{
case Type::LongTyID:
case Type::ULongTyID:
SA = ConstantUInt::get(Type::UByteTy, 32);
Src = BinaryOperator::create(Instruction::Or, Src, new ShiftInst(Instruction::Shr, Src, SA));
case Type::IntTyID:
case Type::UIntTyID:
SA = ConstantUInt::get(Type::UByteTy, 16);
Src = BinaryOperator::create(Instruction::Or, Src, new ShiftInst(Instruction::Shr, Src, SA));
case Type::ShortTyID:
case Type::UShortTyID:
SA = ConstantUInt::get(Type::UByteTy, 8);
Src = BinaryOperator::create(Instruction::Or, Src, new ShiftInst(Instruction::Shr, Src, SA));
default:
SA = ConstantUInt::get(Type::UByteTy, 1);
Src = BinaryOperator::create(Instruction::Or, Src, new ShiftInst(Instruction::Shr, Src, SA));
SA = ConstantUInt::get(Type::UByteTy, 2);
Src = BinaryOperator::create(Instruction::Or, Src, new ShiftInst(Instruction::Shr, Src, SA));
SA = ConstantUInt::get(Type::UByteTy, 4);
Src = BinaryOperator::create(Instruction::Or, Src, new ShiftInst(Instruction::Shr, Src, SA));
};
Src = BinaryOperator::createNot(Src);
Src = new CallInst(new Function(CI->getCalledFunction()->getFunctionType(),
CI->getCalledFunction()->getLinkage(),
"llvm.ctpop"), Src);
CI->replaceAllUsesWith(Src);
break;
}
case Intrinsic::cttz: {
Value *Src = CI->getOperand(1);
Src = BinaryOperator::create(Instruction::And, BinaryOperator::createNot(Src),
BinaryOperator::create(Instruction::Sub, Src,
ConstantUInt::get(CI->getOperand(0)->getType(), 1)));
Src = new CallInst(new Function(CI->getCalledFunction()->getFunctionType(),
CI->getCalledFunction()->getLinkage(),
"llvm.ctpop"), Src);
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->getParent()->getInstList().erase(CI);
}