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llvm-6502/lib/CodeGen/IntrinsicLowering.cpp
Duncan Sands 667d4b8de6 Introduce new linkage types linkonce_odr, weak_odr, common_odr 
and extern_weak_odr.  These are the same as the non-odr versions,
except that they indicate that the global will only be overridden
by an *equivalent* global.  In C, a function with weak linkage can
be overridden by a function which behaves completely differently.
This means that IP passes have to skip weak functions, since any
deductions made from the function definition might be wrong, since
the definition could be replaced by something completely different
at link time.   This is not allowed in C++, thanks to the ODR
(One-Definition-Rule): if a function is replaced by another at
link-time, then the new function must be the same as the original
function.  If a language knows that a function or other global can
only be overridden by an equivalent global, it can give it the
weak_odr linkage type, and the optimizers will understand that it
is alright to make deductions based on the function body.  The
code generators on the other hand map weak and weak_odr linkage
to the same thing.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66339 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-07 15:45:40 +00:00

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//===-- IntrinsicLowering.cpp - Intrinsic Lowering default implementation -===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the IntrinsicLowering class.
//
//===----------------------------------------------------------------------===//
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/Instructions.h"
#include "llvm/Type.h"
#include "llvm/CodeGen/IntrinsicLowering.h"
#include "llvm/Support/Streams.h"
#include "llvm/Target/TargetData.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/STLExtras.h"
using namespace llvm;
template <class ArgIt>
static void EnsureFunctionExists(Module &M, const char *Name,
ArgIt ArgBegin, ArgIt ArgEnd,
const Type *RetTy) {
// Insert a correctly-typed definition now.
std::vector<const Type *> ParamTys;
for (ArgIt I = ArgBegin; I != ArgEnd; ++I)
ParamTys.push_back(I->getType());
M.getOrInsertFunction(Name, FunctionType::get(RetTy, ParamTys, false));
}
static void EnsureFPIntrinsicsExist(Module &M, Function *Fn,
const char *FName,
const char *DName, const char *LDName) {
// Insert definitions for all the floating point types.
switch((int)Fn->arg_begin()->getType()->getTypeID()) {
case Type::FloatTyID:
EnsureFunctionExists(M, FName, Fn->arg_begin(), Fn->arg_end(),
Type::FloatTy);
break;
case Type::DoubleTyID:
EnsureFunctionExists(M, DName, Fn->arg_begin(), Fn->arg_end(),
Type::DoubleTy);
break;
case Type::X86_FP80TyID:
case Type::FP128TyID:
case Type::PPC_FP128TyID:
EnsureFunctionExists(M, LDName, Fn->arg_begin(), Fn->arg_end(),
Fn->arg_begin()->getType());
break;
}
}
/// 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, Constant *&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();
// Get or insert the 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));
}
SmallVector<Value *, 8> Args(ArgBegin, ArgEnd);
CallInst *NewCI = CallInst::Create(FCache, Args.begin(), Args.end(),
CI->getName(), CI);
if (!CI->use_empty())
CI->replaceAllUsesWith(NewCI);
return NewCI;
}
void IntrinsicLowering::AddPrototypes(Module &M) {
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
if (I->isDeclaration() && !I->use_empty())
switch (I->getIntrinsicID()) {
default: break;
case Intrinsic::setjmp:
EnsureFunctionExists(M, "setjmp", I->arg_begin(), I->arg_end(),
Type::Int32Ty);
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:
M.getOrInsertFunction("memcpy", PointerType::getUnqual(Type::Int8Ty),
PointerType::getUnqual(Type::Int8Ty),
PointerType::getUnqual(Type::Int8Ty),
TD.getIntPtrType(), (Type *)0);
break;
case Intrinsic::memmove:
M.getOrInsertFunction("memmove", PointerType::getUnqual(Type::Int8Ty),
PointerType::getUnqual(Type::Int8Ty),
PointerType::getUnqual(Type::Int8Ty),
TD.getIntPtrType(), (Type *)0);
break;
case Intrinsic::memset:
M.getOrInsertFunction("memset", PointerType::getUnqual(Type::Int8Ty),
PointerType::getUnqual(Type::Int8Ty),
Type::Int32Ty,
TD.getIntPtrType(), (Type *)0);
break;
case Intrinsic::sqrt:
EnsureFPIntrinsicsExist(M, I, "sqrtf", "sqrt", "sqrtl");
break;
case Intrinsic::sin:
EnsureFPIntrinsicsExist(M, I, "sinf", "sin", "sinl");
break;
case Intrinsic::cos:
EnsureFPIntrinsicsExist(M, I, "cosf", "cos", "cosl");
break;
case Intrinsic::pow:
EnsureFPIntrinsicsExist(M, I, "powf", "pow", "powl");
break;
case Intrinsic::log:
EnsureFPIntrinsicsExist(M, I, "logf", "log", "logl");
break;
case Intrinsic::log2:
EnsureFPIntrinsicsExist(M, I, "log2f", "log2", "log2l");
break;
case Intrinsic::log10:
EnsureFPIntrinsicsExist(M, I, "log10f", "log10", "log10l");
break;
case Intrinsic::exp:
EnsureFPIntrinsicsExist(M, I, "expf", "exp", "expl");
break;
case Intrinsic::exp2:
EnsureFPIntrinsicsExist(M, I, "exp2f", "exp2", "exp2l");
break;
}
}
/// LowerBSWAP - Emit the code to lower bswap of V before the specified
/// instruction IP.
static Value *LowerBSWAP(Value *V, Instruction *IP) {
assert(V->getType()->isInteger() && "Can't bswap a non-integer type!");
unsigned BitSize = V->getType()->getPrimitiveSizeInBits();
switch(BitSize) {
default: assert(0 && "Unhandled type size of value to byteswap!");
case 16: {
Value *Tmp1 = BinaryOperator::CreateShl(V,
ConstantInt::get(V->getType(),8),"bswap.2",IP);
Value *Tmp2 = BinaryOperator::CreateLShr(V,
ConstantInt::get(V->getType(),8),"bswap.1",IP);
V = BinaryOperator::CreateOr(Tmp1, Tmp2, "bswap.i16", IP);
break;
}
case 32: {
Value *Tmp4 = BinaryOperator::CreateShl(V,
ConstantInt::get(V->getType(),24),"bswap.4", IP);
Value *Tmp3 = BinaryOperator::CreateShl(V,
ConstantInt::get(V->getType(),8),"bswap.3",IP);
Value *Tmp2 = BinaryOperator::CreateLShr(V,
ConstantInt::get(V->getType(),8),"bswap.2",IP);
Value *Tmp1 = BinaryOperator::CreateLShr(V,
ConstantInt::get(V->getType(),24),"bswap.1", IP);
Tmp3 = BinaryOperator::CreateAnd(Tmp3,
ConstantInt::get(Type::Int32Ty, 0xFF0000),
"bswap.and3", IP);
Tmp2 = BinaryOperator::CreateAnd(Tmp2,
ConstantInt::get(Type::Int32Ty, 0xFF00),
"bswap.and2", IP);
Tmp4 = BinaryOperator::CreateOr(Tmp4, Tmp3, "bswap.or1", IP);
Tmp2 = BinaryOperator::CreateOr(Tmp2, Tmp1, "bswap.or2", IP);
V = BinaryOperator::CreateOr(Tmp4, Tmp2, "bswap.i32", IP);
break;
}
case 64: {
Value *Tmp8 = BinaryOperator::CreateShl(V,
ConstantInt::get(V->getType(),56),"bswap.8", IP);
Value *Tmp7 = BinaryOperator::CreateShl(V,
ConstantInt::get(V->getType(),40),"bswap.7", IP);
Value *Tmp6 = BinaryOperator::CreateShl(V,
ConstantInt::get(V->getType(),24),"bswap.6", IP);
Value *Tmp5 = BinaryOperator::CreateShl(V,
ConstantInt::get(V->getType(),8),"bswap.5", IP);
Value* Tmp4 = BinaryOperator::CreateLShr(V,
ConstantInt::get(V->getType(),8),"bswap.4", IP);
Value* Tmp3 = BinaryOperator::CreateLShr(V,
ConstantInt::get(V->getType(),24),"bswap.3", IP);
Value* Tmp2 = BinaryOperator::CreateLShr(V,
ConstantInt::get(V->getType(),40),"bswap.2", IP);
Value* Tmp1 = BinaryOperator::CreateLShr(V,
ConstantInt::get(V->getType(),56),"bswap.1", IP);
Tmp7 = BinaryOperator::CreateAnd(Tmp7,
ConstantInt::get(Type::Int64Ty,
0xFF000000000000ULL),
"bswap.and7", IP);
Tmp6 = BinaryOperator::CreateAnd(Tmp6,
ConstantInt::get(Type::Int64Ty, 0xFF0000000000ULL),
"bswap.and6", IP);
Tmp5 = BinaryOperator::CreateAnd(Tmp5,
ConstantInt::get(Type::Int64Ty, 0xFF00000000ULL),
"bswap.and5", IP);
Tmp4 = BinaryOperator::CreateAnd(Tmp4,
ConstantInt::get(Type::Int64Ty, 0xFF000000ULL),
"bswap.and4", IP);
Tmp3 = BinaryOperator::CreateAnd(Tmp3,
ConstantInt::get(Type::Int64Ty, 0xFF0000ULL),
"bswap.and3", IP);
Tmp2 = BinaryOperator::CreateAnd(Tmp2,
ConstantInt::get(Type::Int64Ty, 0xFF00ULL),
"bswap.and2", IP);
Tmp8 = BinaryOperator::CreateOr(Tmp8, Tmp7, "bswap.or1", IP);
Tmp6 = BinaryOperator::CreateOr(Tmp6, Tmp5, "bswap.or2", IP);
Tmp4 = BinaryOperator::CreateOr(Tmp4, Tmp3, "bswap.or3", IP);
Tmp2 = BinaryOperator::CreateOr(Tmp2, Tmp1, "bswap.or4", IP);
Tmp8 = BinaryOperator::CreateOr(Tmp8, Tmp6, "bswap.or5", IP);
Tmp4 = BinaryOperator::CreateOr(Tmp4, Tmp2, "bswap.or6", IP);
V = BinaryOperator::CreateOr(Tmp8, Tmp4, "bswap.i64", IP);
break;
}
}
return V;
}
/// LowerCTPOP - Emit the code to lower ctpop of V before the specified
/// instruction IP.
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
};
unsigned BitSize = V->getType()->getPrimitiveSizeInBits();
unsigned WordSize = (BitSize + 63) / 64;
Value *Count = ConstantInt::get(V->getType(), 0);
for (unsigned n = 0; n < WordSize; ++n) {
Value *PartValue = V;
for (unsigned i = 1, ct = 0; i < (BitSize>64 ? 64 : BitSize);
i <<= 1, ++ct) {
Value *MaskCst = ConstantInt::get(V->getType(), MaskValues[ct]);
Value *LHS = BinaryOperator::CreateAnd(
PartValue, MaskCst, "cppop.and1", IP);
Value *VShift = BinaryOperator::CreateLShr(PartValue,
ConstantInt::get(V->getType(), i), "ctpop.sh", IP);
Value *RHS = BinaryOperator::CreateAnd(VShift, MaskCst, "cppop.and2", IP);
PartValue = BinaryOperator::CreateAdd(LHS, RHS, "ctpop.step", IP);
}
Count = BinaryOperator::CreateAdd(PartValue, Count, "ctpop.part", IP);
if (BitSize > 64) {
V = BinaryOperator::CreateLShr(V, ConstantInt::get(V->getType(), 64),
"ctpop.part.sh", IP);
BitSize -= 64;
}
}
return Count;
}
/// LowerCTLZ - Emit the code to lower ctlz of V before the specified
/// instruction IP.
static Value *LowerCTLZ(Value *V, Instruction *IP) {
unsigned BitSize = V->getType()->getPrimitiveSizeInBits();
for (unsigned i = 1; i < BitSize; i <<= 1) {
Value *ShVal = ConstantInt::get(V->getType(), i);
ShVal = BinaryOperator::CreateLShr(V, ShVal, "ctlz.sh", IP);
V = BinaryOperator::CreateOr(V, ShVal, "ctlz.step", IP);
}
V = BinaryOperator::CreateNot(V, "", IP);
return LowerCTPOP(V, IP);
}
/// Convert the llvm.part.select.iX.iY intrinsic. This intrinsic takes
/// three integer arguments. The first argument is the Value from which the
/// bits will be selected. It may be of any bit width. The second and third
/// arguments specify a range of bits to select with the second argument
/// specifying the low bit and the third argument specifying the high bit. Both
/// must be type i32. The result is the corresponding selected bits from the
/// Value in the same width as the Value (first argument). If the low bit index
/// is higher than the high bit index then the inverse selection is done and
/// the bits are returned in inverse order.
/// @brief Lowering of llvm.part.select intrinsic.
static Instruction *LowerPartSelect(CallInst *CI) {
// Make sure we're dealing with a part select intrinsic here
Function *F = CI->getCalledFunction();
const FunctionType *FT = F->getFunctionType();
if (!F->isDeclaration() || !FT->getReturnType()->isInteger() ||
FT->getNumParams() != 3 || !FT->getParamType(0)->isInteger() ||
!FT->getParamType(1)->isInteger() || !FT->getParamType(2)->isInteger())
return CI;
// Get the intrinsic implementation function by converting all the . to _
// in the intrinsic's function name and then reconstructing the function
// declaration.
std::string Name(F->getName());
for (unsigned i = 4; i < Name.length(); ++i)
if (Name[i] == '.')
Name[i] = '_';
Module* M = F->getParent();
F = cast<Function>(M->getOrInsertFunction(Name, FT));
F->setLinkage(GlobalValue::WeakAnyLinkage);
// If we haven't defined the impl function yet, do so now
if (F->isDeclaration()) {
// Get the arguments to the function
Function::arg_iterator args = F->arg_begin();
Value* Val = args++; Val->setName("Val");
Value* Lo = args++; Lo->setName("Lo");
Value* Hi = args++; Hi->setName("High");
// We want to select a range of bits here such that [Hi, Lo] is shifted
// down to the low bits. However, it is quite possible that Hi is smaller
// than Lo in which case the bits have to be reversed.
// Create the blocks we will need for the two cases (forward, reverse)
BasicBlock* CurBB = BasicBlock::Create("entry", F);
BasicBlock *RevSize = BasicBlock::Create("revsize", CurBB->getParent());
BasicBlock *FwdSize = BasicBlock::Create("fwdsize", CurBB->getParent());
BasicBlock *Compute = BasicBlock::Create("compute", CurBB->getParent());
BasicBlock *Reverse = BasicBlock::Create("reverse", CurBB->getParent());
BasicBlock *RsltBlk = BasicBlock::Create("result", CurBB->getParent());
// Cast Hi and Lo to the size of Val so the widths are all the same
if (Hi->getType() != Val->getType())
Hi = CastInst::CreateIntegerCast(Hi, Val->getType(), false,
"tmp", CurBB);
if (Lo->getType() != Val->getType())
Lo = CastInst::CreateIntegerCast(Lo, Val->getType(), false,
"tmp", CurBB);
// Compute a few things that both cases will need, up front.
Constant* Zero = ConstantInt::get(Val->getType(), 0);
Constant* One = ConstantInt::get(Val->getType(), 1);
Constant* AllOnes = ConstantInt::getAllOnesValue(Val->getType());
// Compare the Hi and Lo bit positions. This is used to determine
// which case we have (forward or reverse)
ICmpInst *Cmp = new ICmpInst(ICmpInst::ICMP_ULT, Hi, Lo, "less",CurBB);
BranchInst::Create(RevSize, FwdSize, Cmp, CurBB);
// First, copmute the number of bits in the forward case.
Instruction* FBitSize =
BinaryOperator::CreateSub(Hi, Lo,"fbits", FwdSize);
BranchInst::Create(Compute, FwdSize);
// Second, compute the number of bits in the reverse case.
Instruction* RBitSize =
BinaryOperator::CreateSub(Lo, Hi, "rbits", RevSize);
BranchInst::Create(Compute, RevSize);
// Now, compute the bit range. Start by getting the bitsize and the shift
// amount (either Hi or Lo) from PHI nodes. Then we compute a mask for
// the number of bits we want in the range. We shift the bits down to the
// least significant bits, apply the mask to zero out unwanted high bits,
// and we have computed the "forward" result. It may still need to be
// reversed.
// Get the BitSize from one of the two subtractions
PHINode *BitSize = PHINode::Create(Val->getType(), "bits", Compute);
BitSize->reserveOperandSpace(2);
BitSize->addIncoming(FBitSize, FwdSize);
BitSize->addIncoming(RBitSize, RevSize);
// Get the ShiftAmount as the smaller of Hi/Lo
PHINode *ShiftAmt = PHINode::Create(Val->getType(), "shiftamt", Compute);
ShiftAmt->reserveOperandSpace(2);
ShiftAmt->addIncoming(Lo, FwdSize);
ShiftAmt->addIncoming(Hi, RevSize);
// Increment the bit size
Instruction *BitSizePlusOne =
BinaryOperator::CreateAdd(BitSize, One, "bits", Compute);
// Create a Mask to zero out the high order bits.
Instruction* Mask =
BinaryOperator::CreateShl(AllOnes, BitSizePlusOne, "mask", Compute);
Mask = BinaryOperator::CreateNot(Mask, "mask", Compute);
// Shift the bits down and apply the mask
Instruction* FRes =
BinaryOperator::CreateLShr(Val, ShiftAmt, "fres", Compute);
FRes = BinaryOperator::CreateAnd(FRes, Mask, "fres", Compute);
BranchInst::Create(Reverse, RsltBlk, Cmp, Compute);
// In the Reverse block we have the mask already in FRes but we must reverse
// it by shifting FRes bits right and putting them in RRes by shifting them
// in from left.
// First set up our loop counters
PHINode *Count = PHINode::Create(Val->getType(), "count", Reverse);
Count->reserveOperandSpace(2);
Count->addIncoming(BitSizePlusOne, Compute);
// Next, get the value that we are shifting.
PHINode *BitsToShift = PHINode::Create(Val->getType(), "val", Reverse);
BitsToShift->reserveOperandSpace(2);
BitsToShift->addIncoming(FRes, Compute);
// Finally, get the result of the last computation
PHINode *RRes = PHINode::Create(Val->getType(), "rres", Reverse);
RRes->reserveOperandSpace(2);
RRes->addIncoming(Zero, Compute);
// Decrement the counter
Instruction *Decr = BinaryOperator::CreateSub(Count, One, "decr", Reverse);
Count->addIncoming(Decr, Reverse);
// Compute the Bit that we want to move
Instruction *Bit =
BinaryOperator::CreateAnd(BitsToShift, One, "bit", Reverse);
// Compute the new value for next iteration.
Instruction *NewVal =
BinaryOperator::CreateLShr(BitsToShift, One, "rshift", Reverse);
BitsToShift->addIncoming(NewVal, Reverse);
// Shift the bit into the low bits of the result.
Instruction *NewRes =
BinaryOperator::CreateShl(RRes, One, "lshift", Reverse);
NewRes = BinaryOperator::CreateOr(NewRes, Bit, "addbit", Reverse);
RRes->addIncoming(NewRes, Reverse);
// Terminate loop if we've moved all the bits.
ICmpInst *Cond =
new ICmpInst(ICmpInst::ICMP_EQ, Decr, Zero, "cond", Reverse);
BranchInst::Create(RsltBlk, Reverse, Cond, Reverse);
// Finally, in the result block, select one of the two results with a PHI
// node and return the result;
CurBB = RsltBlk;
PHINode *BitSelect = PHINode::Create(Val->getType(), "part_select", CurBB);
BitSelect->reserveOperandSpace(2);
BitSelect->addIncoming(FRes, Compute);
BitSelect->addIncoming(NewRes, Reverse);
ReturnInst::Create(BitSelect, CurBB);
}
// Return a call to the implementation function
Value *Args[] = {
CI->getOperand(1),
CI->getOperand(2),
CI->getOperand(3)
};
return CallInst::Create(F, Args, array_endof(Args), CI->getName(), CI);
}
/// Convert the llvm.part.set.iX.iY.iZ intrinsic. This intrinsic takes
/// four integer arguments (iAny %Value, iAny %Replacement, i32 %Low, i32 %High)
/// The first two arguments can be any bit width. The result is the same width
/// as %Value. The operation replaces bits between %Low and %High with the value
/// in %Replacement. If %Replacement is not the same width, it is truncated or
/// zero extended as appropriate to fit the bits being replaced. If %Low is
/// greater than %High then the inverse set of bits are replaced.
/// @brief Lowering of llvm.bit.part.set intrinsic.
static Instruction *LowerPartSet(CallInst *CI) {
// Make sure we're dealing with a part select intrinsic here
Function *F = CI->getCalledFunction();
const FunctionType *FT = F->getFunctionType();
if (!F->isDeclaration() || !FT->getReturnType()->isInteger() ||
FT->getNumParams() != 4 || !FT->getParamType(0)->isInteger() ||
!FT->getParamType(1)->isInteger() || !FT->getParamType(2)->isInteger() ||
!FT->getParamType(3)->isInteger())
return CI;
// Get the intrinsic implementation function by converting all the . to _
// in the intrinsic's function name and then reconstructing the function
// declaration.
std::string Name(F->getName());
for (unsigned i = 4; i < Name.length(); ++i)
if (Name[i] == '.')
Name[i] = '_';
Module* M = F->getParent();
F = cast<Function>(M->getOrInsertFunction(Name, FT));
F->setLinkage(GlobalValue::WeakAnyLinkage);
// If we haven't defined the impl function yet, do so now
if (F->isDeclaration()) {
// Get the arguments for the function.
Function::arg_iterator args = F->arg_begin();
Value* Val = args++; Val->setName("Val");
Value* Rep = args++; Rep->setName("Rep");
Value* Lo = args++; Lo->setName("Lo");
Value* Hi = args++; Hi->setName("Hi");
// Get some types we need
const IntegerType* ValTy = cast<IntegerType>(Val->getType());
const IntegerType* RepTy = cast<IntegerType>(Rep->getType());
uint32_t ValBits = ValTy->getBitWidth();
uint32_t RepBits = RepTy->getBitWidth();
// Constant Definitions
ConstantInt* RepBitWidth = ConstantInt::get(Type::Int32Ty, RepBits);
ConstantInt* RepMask = ConstantInt::getAllOnesValue(RepTy);
ConstantInt* ValMask = ConstantInt::getAllOnesValue(ValTy);
ConstantInt* One = ConstantInt::get(Type::Int32Ty, 1);
ConstantInt* ValOne = ConstantInt::get(ValTy, 1);
ConstantInt* Zero = ConstantInt::get(Type::Int32Ty, 0);
ConstantInt* ValZero = ConstantInt::get(ValTy, 0);
// Basic blocks we fill in below.
BasicBlock* entry = BasicBlock::Create("entry", F, 0);
BasicBlock* large = BasicBlock::Create("large", F, 0);
BasicBlock* small = BasicBlock::Create("small", F, 0);
BasicBlock* reverse = BasicBlock::Create("reverse", F, 0);
BasicBlock* result = BasicBlock::Create("result", F, 0);
// BASIC BLOCK: entry
// First, get the number of bits that we're placing as an i32
ICmpInst* is_forward =
new ICmpInst(ICmpInst::ICMP_ULT, Lo, Hi, "", entry);
SelectInst* Hi_pn = SelectInst::Create(is_forward, Hi, Lo, "", entry);
SelectInst* Lo_pn = SelectInst::Create(is_forward, Lo, Hi, "", entry);
BinaryOperator* NumBits = BinaryOperator::CreateSub(Hi_pn, Lo_pn, "",entry);
NumBits = BinaryOperator::CreateAdd(NumBits, One, "", entry);
// Now, convert Lo and Hi to ValTy bit width
if (ValBits > 32) {
Lo = new ZExtInst(Lo_pn, ValTy, "", entry);
} else if (ValBits < 32) {
Lo = new TruncInst(Lo_pn, ValTy, "", entry);
} else {
Lo = Lo_pn;
}
// Determine if the replacement bits are larger than the number of bits we
// are replacing and deal with it.
ICmpInst* is_large =
new ICmpInst(ICmpInst::ICMP_ULT, NumBits, RepBitWidth, "", entry);
BranchInst::Create(large, small, is_large, entry);
// BASIC BLOCK: large
Instruction* MaskBits =
BinaryOperator::CreateSub(RepBitWidth, NumBits, "", large);
MaskBits = CastInst::CreateIntegerCast(MaskBits, RepMask->getType(),
false, "", large);
BinaryOperator* Mask1 =
BinaryOperator::CreateLShr(RepMask, MaskBits, "", large);
BinaryOperator* Rep2 = BinaryOperator::CreateAnd(Mask1, Rep, "", large);
BranchInst::Create(small, large);
// BASIC BLOCK: small
PHINode* Rep3 = PHINode::Create(RepTy, "", small);
Rep3->reserveOperandSpace(2);
Rep3->addIncoming(Rep2, large);
Rep3->addIncoming(Rep, entry);
Value* Rep4 = Rep3;
if (ValBits > RepBits)
Rep4 = new ZExtInst(Rep3, ValTy, "", small);
else if (ValBits < RepBits)
Rep4 = new TruncInst(Rep3, ValTy, "", small);
BranchInst::Create(result, reverse, is_forward, small);
// BASIC BLOCK: reverse (reverses the bits of the replacement)
// Set up our loop counter as a PHI so we can decrement on each iteration.
// We will loop for the number of bits in the replacement value.
PHINode *Count = PHINode::Create(Type::Int32Ty, "count", reverse);
Count->reserveOperandSpace(2);
Count->addIncoming(NumBits, small);
// Get the value that we are shifting bits out of as a PHI because
// we'll change this with each iteration.
PHINode *BitsToShift = PHINode::Create(Val->getType(), "val", reverse);
BitsToShift->reserveOperandSpace(2);
BitsToShift->addIncoming(Rep4, small);
// Get the result of the last computation or zero on first iteration
PHINode *RRes = PHINode::Create(Val->getType(), "rres", reverse);
RRes->reserveOperandSpace(2);
RRes->addIncoming(ValZero, small);
// Decrement the loop counter by one
Instruction *Decr = BinaryOperator::CreateSub(Count, One, "", reverse);
Count->addIncoming(Decr, reverse);
// Get the bit that we want to move into the result
Value *Bit = BinaryOperator::CreateAnd(BitsToShift, ValOne, "", reverse);
// Compute the new value of the bits to shift for the next iteration.
Value *NewVal = BinaryOperator::CreateLShr(BitsToShift, ValOne,"", reverse);
BitsToShift->addIncoming(NewVal, reverse);
// Shift the bit we extracted into the low bit of the result.
Instruction *NewRes = BinaryOperator::CreateShl(RRes, ValOne, "", reverse);
NewRes = BinaryOperator::CreateOr(NewRes, Bit, "", reverse);
RRes->addIncoming(NewRes, reverse);
// Terminate loop if we've moved all the bits.
ICmpInst *Cond = new ICmpInst(ICmpInst::ICMP_EQ, Decr, Zero, "", reverse);
BranchInst::Create(result, reverse, Cond, reverse);
// BASIC BLOCK: result
PHINode *Rplcmnt = PHINode::Create(Val->getType(), "", result);
Rplcmnt->reserveOperandSpace(2);
Rplcmnt->addIncoming(NewRes, reverse);
Rplcmnt->addIncoming(Rep4, small);
Value* t0 = CastInst::CreateIntegerCast(NumBits,ValTy,false,"",result);
Value* t1 = BinaryOperator::CreateShl(ValMask, Lo, "", result);
Value* t2 = BinaryOperator::CreateNot(t1, "", result);
Value* t3 = BinaryOperator::CreateShl(t1, t0, "", result);
Value* t4 = BinaryOperator::CreateOr(t2, t3, "", result);
Value* t5 = BinaryOperator::CreateAnd(t4, Val, "", result);
Value* t6 = BinaryOperator::CreateShl(Rplcmnt, Lo, "", result);
Value* Rslt = BinaryOperator::CreateOr(t5, t6, "part_set", result);
ReturnInst::Create(Rslt, result);
}
// Return a call to the implementation function
Value *Args[] = {
CI->getOperand(1),
CI->getOperand(2),
CI->getOperand(3),
CI->getOperand(4)
};
return CallInst::Create(F, Args, array_endof(Args), CI->getName(), CI);
}
static void ReplaceFPIntrinsicWithCall(CallInst *CI, Constant *FCache,
Constant *DCache, Constant *LDCache,
const char *Fname, const char *Dname,
const char *LDname) {
switch (CI->getOperand(1)->getType()->getTypeID()) {
default: assert(0 && "Invalid type in intrinsic"); abort();
case Type::FloatTyID:
ReplaceCallWith(Fname, CI, CI->op_begin()+1, CI->op_end(),
Type::FloatTy, FCache);
break;
case Type::DoubleTyID:
ReplaceCallWith(Dname, CI, CI->op_begin()+1, CI->op_end(),
Type::DoubleTy, DCache);
break;
case Type::X86_FP80TyID:
case Type::FP128TyID:
case Type::PPC_FP128TyID:
ReplaceCallWith(LDname, CI, CI->op_begin()+1, CI->op_end(),
CI->getOperand(1)->getType(), LDCache);
break;
}
}
void IntrinsicLowering::LowerIntrinsicCall(CallInst *CI) {
Function *Callee = CI->getCalledFunction();
assert(Callee && "Cannot lower an indirect call!");
switch (Callee->getIntrinsicID()) {
case Intrinsic::not_intrinsic:
cerr << "Cannot lower a call to a non-intrinsic function '"
<< Callee->getName() << "'!\n";
abort();
default:
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 Constant *SetjmpFCache = 0;
Value *V = ReplaceCallWith("setjmp", CI, CI->op_begin()+1, CI->op_end(),
Type::Int32Ty, 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 Constant *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 Constant *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::bswap:
CI->replaceAllUsesWith(LowerBSWAP(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::part_select:
CI->replaceAllUsesWith(LowerPartSelect(CI));
break;
case Intrinsic::part_set:
CI->replaceAllUsesWith(LowerPartSet(CI));
break;
case Intrinsic::stacksave:
case Intrinsic::stackrestore: {
static bool Warned = false;
if (!Warned)
cerr << "WARNING: this target does not support the llvm.stack"
<< (Callee->getIntrinsicID() == Intrinsic::stacksave ?
"save" : "restore") << " intrinsic.\n";
Warned = true;
if (Callee->getIntrinsicID() == Intrinsic::stacksave)
CI->replaceAllUsesWith(Constant::getNullValue(CI->getType()));
break;
}
case Intrinsic::returnaddress:
case Intrinsic::frameaddress:
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::readcyclecounter: {
cerr << "WARNING: this target does not support the llvm.readcyclecoun"
<< "ter intrinsic. It is being lowered to a constant 0\n";
CI->replaceAllUsesWith(ConstantInt::get(Type::Int64Ty, 0));
break;
}
case Intrinsic::dbg_stoppoint:
case Intrinsic::dbg_region_start:
case Intrinsic::dbg_region_end:
case Intrinsic::dbg_func_start:
case Intrinsic::dbg_declare:
break; // Simply strip out debugging intrinsics
case Intrinsic::eh_exception:
case Intrinsic::eh_selector_i32:
case Intrinsic::eh_selector_i64:
CI->replaceAllUsesWith(Constant::getNullValue(CI->getType()));
break;
case Intrinsic::eh_typeid_for_i32:
case Intrinsic::eh_typeid_for_i64:
// Return something different to eh_selector.
CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1));
break;
case Intrinsic::var_annotation:
break; // Strip out annotate intrinsic
case Intrinsic::memcpy: {
static Constant *MemcpyFCache = 0;
Value *Size = CI->getOperand(3);
const Type *IntPtr = TD.getIntPtrType();
if (Size->getType()->getPrimitiveSizeInBits() <
IntPtr->getPrimitiveSizeInBits())
Size = new ZExtInst(Size, IntPtr, "", CI);
else if (Size->getType()->getPrimitiveSizeInBits() >
IntPtr->getPrimitiveSizeInBits())
Size = new TruncInst(Size, IntPtr, "", CI);
Value *Ops[3];
Ops[0] = CI->getOperand(1);
Ops[1] = CI->getOperand(2);
Ops[2] = Size;
ReplaceCallWith("memcpy", CI, Ops, Ops+3, CI->getOperand(1)->getType(),
MemcpyFCache);
break;
}
case Intrinsic::memmove: {
static Constant *MemmoveFCache = 0;
Value *Size = CI->getOperand(3);
const Type *IntPtr = TD.getIntPtrType();
if (Size->getType()->getPrimitiveSizeInBits() <
IntPtr->getPrimitiveSizeInBits())
Size = new ZExtInst(Size, IntPtr, "", CI);
else if (Size->getType()->getPrimitiveSizeInBits() >
IntPtr->getPrimitiveSizeInBits())
Size = new TruncInst(Size, IntPtr, "", CI);
Value *Ops[3];
Ops[0] = CI->getOperand(1);
Ops[1] = CI->getOperand(2);
Ops[2] = Size;
ReplaceCallWith("memmove", CI, Ops, Ops+3, CI->getOperand(1)->getType(),
MemmoveFCache);
break;
}
case Intrinsic::memset: {
static Constant *MemsetFCache = 0;
Value *Size = CI->getOperand(3);
const Type *IntPtr = TD.getIntPtrType();
if (Size->getType()->getPrimitiveSizeInBits() <
IntPtr->getPrimitiveSizeInBits())
Size = new ZExtInst(Size, IntPtr, "", CI);
else if (Size->getType()->getPrimitiveSizeInBits() >
IntPtr->getPrimitiveSizeInBits())
Size = new TruncInst(Size, IntPtr, "", CI);
Value *Ops[3];
Ops[0] = CI->getOperand(1);
// Extend the amount to i32.
Ops[1] = new ZExtInst(CI->getOperand(2), Type::Int32Ty, "", CI);
Ops[2] = Size;
ReplaceCallWith("memset", CI, Ops, Ops+3, CI->getOperand(1)->getType(),
MemsetFCache);
break;
}
case Intrinsic::sqrt: {
static Constant *sqrtFCache = 0;
static Constant *sqrtDCache = 0;
static Constant *sqrtLDCache = 0;
ReplaceFPIntrinsicWithCall(CI, sqrtFCache, sqrtDCache, sqrtLDCache,
"sqrtf", "sqrt", "sqrtl");
break;
}
case Intrinsic::log: {
static Constant *logFCache = 0;
static Constant *logDCache = 0;
static Constant *logLDCache = 0;
ReplaceFPIntrinsicWithCall(CI, logFCache, logDCache, logLDCache,
"logf", "log", "logl");
break;
}
case Intrinsic::log2: {
static Constant *log2FCache = 0;
static Constant *log2DCache = 0;
static Constant *log2LDCache = 0;
ReplaceFPIntrinsicWithCall(CI, log2FCache, log2DCache, log2LDCache,
"log2f", "log2", "log2l");
break;
}
case Intrinsic::log10: {
static Constant *log10FCache = 0;
static Constant *log10DCache = 0;
static Constant *log10LDCache = 0;
ReplaceFPIntrinsicWithCall(CI, log10FCache, log10DCache, log10LDCache,
"log10f", "log10", "log10l");
break;
}
case Intrinsic::exp: {
static Constant *expFCache = 0;
static Constant *expDCache = 0;
static Constant *expLDCache = 0;
ReplaceFPIntrinsicWithCall(CI, expFCache, expDCache, expLDCache,
"expf", "exp", "expl");
break;
}
case Intrinsic::exp2: {
static Constant *exp2FCache = 0;
static Constant *exp2DCache = 0;
static Constant *exp2LDCache = 0;
ReplaceFPIntrinsicWithCall(CI, exp2FCache, exp2DCache, exp2LDCache,
"exp2f", "exp2", "exp2l");
break;
}
case Intrinsic::pow: {
static Constant *powFCache = 0;
static Constant *powDCache = 0;
static Constant *powLDCache = 0;
ReplaceFPIntrinsicWithCall(CI, powFCache, powDCache, powLDCache,
"powf", "pow", "powl");
break;
}
case Intrinsic::flt_rounds:
// Lower to "round to the nearest"
if (CI->getType() != Type::VoidTy)
CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1));
break;
}
assert(CI->use_empty() &&
"Lowering should have eliminated any uses of the intrinsic call!");
CI->eraseFromParent();
}
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