llvm-6502/lib/CodeGen/IntrinsicLowering.cpp

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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/Type.h"
#include "llvm/CodeGen/IntrinsicLowering.h"
#include "llvm/Support/IRBuilder.h"
#include "llvm/Target/TargetData.h"
#include "llvm/ADT/SmallVector.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) {
// 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());
Constant* FCache = M->getOrInsertFunction(NewFn,
FunctionType::get(RetTy, ParamTys, false));
IRBuilder<> Builder(CI->getParent(), CI);
SmallVector<Value *, 8> Args(ArgBegin, ArgEnd);
CallInst *NewCI = Builder.CreateCall(FCache, Args.begin(), Args.end());
NewCI->setName(CI->getName());
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();
IRBuilder<> Builder(IP->getParent(), IP);
switch(BitSize) {
default: assert(0 && "Unhandled type size of value to byteswap!");
case 16: {
Value *Tmp1 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 8),
"bswap.2");
Value *Tmp2 = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 8),
"bswap.1");
V = Builder.CreateOr(Tmp1, Tmp2, "bswap.i16");
break;
}
case 32: {
Value *Tmp4 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 24),
"bswap.4");
Value *Tmp3 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 8),
"bswap.3");
Value *Tmp2 = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 8),
"bswap.2");
Value *Tmp1 = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 24),
"bswap.1");
Tmp3 = Builder.CreateAnd(Tmp3, ConstantInt::get(Type::Int32Ty, 0xFF0000),
"bswap.and3");
Tmp2 = Builder.CreateAnd(Tmp2, ConstantInt::get(Type::Int32Ty, 0xFF00),
"bswap.and2");
Tmp4 = Builder.CreateOr(Tmp4, Tmp3, "bswap.or1");
Tmp2 = Builder.CreateOr(Tmp2, Tmp1, "bswap.or2");
V = Builder.CreateOr(Tmp4, Tmp2, "bswap.i32");
break;
}
case 64: {
Value *Tmp8 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 56),
"bswap.8");
Value *Tmp7 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 40),
"bswap.7");
Value *Tmp6 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 24),
"bswap.6");
Value *Tmp5 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 8),
"bswap.5");
Value* Tmp4 = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 8),
"bswap.4");
Value* Tmp3 = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 24),
"bswap.3");
Value* Tmp2 = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 40),
"bswap.2");
Value* Tmp1 = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 56),
"bswap.1");
Tmp7 = Builder.CreateAnd(Tmp7,
ConstantInt::get(Type::Int64Ty,
0xFF000000000000ULL),
"bswap.and7");
Tmp6 = Builder.CreateAnd(Tmp6,
ConstantInt::get(Type::Int64Ty,
0xFF0000000000ULL),
"bswap.and6");
Tmp5 = Builder.CreateAnd(Tmp5,
ConstantInt::get(Type::Int64Ty, 0xFF00000000ULL),
"bswap.and5");
Tmp4 = Builder.CreateAnd(Tmp4,
ConstantInt::get(Type::Int64Ty, 0xFF000000ULL),
"bswap.and4");
Tmp3 = Builder.CreateAnd(Tmp3,
ConstantInt::get(Type::Int64Ty, 0xFF0000ULL),
"bswap.and3");
Tmp2 = Builder.CreateAnd(Tmp2,
ConstantInt::get(Type::Int64Ty, 0xFF00ULL),
"bswap.and2");
Tmp8 = Builder.CreateOr(Tmp8, Tmp7, "bswap.or1");
Tmp6 = Builder.CreateOr(Tmp6, Tmp5, "bswap.or2");
Tmp4 = Builder.CreateOr(Tmp4, Tmp3, "bswap.or3");
Tmp2 = Builder.CreateOr(Tmp2, Tmp1, "bswap.or4");
Tmp8 = Builder.CreateOr(Tmp8, Tmp6, "bswap.or5");
Tmp4 = Builder.CreateOr(Tmp4, Tmp2, "bswap.or6");
V = Builder.CreateOr(Tmp8, Tmp4, "bswap.i64");
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
};
IRBuilder<> Builder(IP->getParent(), IP);
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 = Builder.CreateAnd(PartValue, MaskCst, "cppop.and1");
Value *VShift = Builder.CreateLShr(PartValue,
ConstantInt::get(V->getType(), i),
"ctpop.sh");
Value *RHS = Builder.CreateAnd(VShift, MaskCst, "cppop.and2");
PartValue = Builder.CreateAdd(LHS, RHS, "ctpop.step");
}
Count = Builder.CreateAdd(PartValue, Count, "ctpop.part");
if (BitSize > 64) {
V = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 64),
"ctpop.part.sh");
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) {
IRBuilder<> Builder(IP->getParent(), IP);
unsigned BitSize = V->getType()->getPrimitiveSizeInBits();
for (unsigned i = 1; i < BitSize; i <<= 1) {
Value *ShVal = ConstantInt::get(V->getType(), i);
ShVal = Builder.CreateLShr(V, ShVal, "ctlz.sh");
V = Builder.CreateOr(V, ShVal, "ctlz.step");
}
V = Builder.CreateNot(V);
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) {
IRBuilder<> Builder;
// 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());
Builder.SetInsertPoint(CurBB);
// Cast Hi and Lo to the size of Val so the widths are all the same
if (Hi->getType() != Val->getType())
Hi = Builder.CreateIntCast(Hi, Val->getType(), /* isSigned */ false,
"tmp");
if (Lo->getType() != Val->getType())
Lo = Builder.CreateIntCast(Lo, Val->getType(), /* isSigned */ false,
"tmp");
// 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)
Value *Cmp = Builder.CreateICmpULT(Hi, Lo, "less");
Builder.CreateCondBr(Cmp, RevSize, FwdSize);
// First, compute the number of bits in the forward case.
Builder.SetInsertPoint(FwdSize);
Value* FBitSize = Builder.CreateSub(Hi, Lo, "fbits");
Builder.CreateBr(Compute);
// Second, compute the number of bits in the reverse case.
Builder.SetInsertPoint(RevSize);
Value* RBitSize = Builder.CreateSub(Lo, Hi, "rbits");
Builder.CreateBr(Compute);
// 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.
Builder.SetInsertPoint(Compute);
// Get the BitSize from one of the two subtractions
PHINode *BitSize = Builder.CreatePHI(Val->getType(), "bits");
BitSize->reserveOperandSpace(2);
BitSize->addIncoming(FBitSize, FwdSize);
BitSize->addIncoming(RBitSize, RevSize);
// Get the ShiftAmount as the smaller of Hi/Lo
PHINode *ShiftAmt = Builder.CreatePHI(Val->getType(), "shiftamt");
ShiftAmt->reserveOperandSpace(2);
ShiftAmt->addIncoming(Lo, FwdSize);
ShiftAmt->addIncoming(Hi, RevSize);
// Increment the bit size
Value *BitSizePlusOne = Builder.CreateAdd(BitSize, One, "bits");
// Create a Mask to zero out the high order bits.
Value* Mask = Builder.CreateShl(AllOnes, BitSizePlusOne, "mask");
Mask = Builder.CreateNot(Mask, "mask");
// Shift the bits down and apply the mask
Value* FRes = Builder.CreateLShr(Val, ShiftAmt, "fres");
FRes = Builder.CreateAnd(FRes, Mask, "fres");
Builder.CreateCondBr(Cmp, Reverse, RsltBlk);
// 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.
Builder.SetInsertPoint(Reverse);
// First set up our loop counters
PHINode *Count = Builder.CreatePHI(Val->getType(), "count");
Count->reserveOperandSpace(2);
Count->addIncoming(BitSizePlusOne, Compute);
// Next, get the value that we are shifting.
PHINode *BitsToShift = Builder.CreatePHI(Val->getType(), "val");
BitsToShift->reserveOperandSpace(2);
BitsToShift->addIncoming(FRes, Compute);
// Finally, get the result of the last computation
PHINode *RRes = Builder.CreatePHI(Val->getType(), "rres");
RRes->reserveOperandSpace(2);
RRes->addIncoming(Zero, Compute);
// Decrement the counter
Value *Decr = Builder.CreateSub(Count, One, "decr");
Count->addIncoming(Decr, Reverse);
// Compute the Bit that we want to move
Value *Bit = Builder.CreateAnd(BitsToShift, One, "bit");
// Compute the new value for next iteration.
Value *NewVal = Builder.CreateLShr(BitsToShift, One, "rshift");
BitsToShift->addIncoming(NewVal, Reverse);
// Shift the bit into the low bits of the result.
Value *NewRes = Builder.CreateShl(RRes, One, "lshift");
NewRes = Builder.CreateOr(NewRes, Bit, "addbit");
RRes->addIncoming(NewRes, Reverse);
// Terminate loop if we've moved all the bits.
Value *Cond = Builder.CreateICmpEQ(Decr, Zero, "cond");
Builder.CreateCondBr(Cond, RsltBlk, Reverse);
// Finally, in the result block, select one of the two results with a PHI
// node and return the result;
Builder.SetInsertPoint(RsltBlk);
PHINode *BitSelect = Builder.CreatePHI(Val->getType(), "part_select");
BitSelect->reserveOperandSpace(2);
BitSelect->addIncoming(FRes, Compute);
BitSelect->addIncoming(NewRes, Reverse);
Builder.CreateRet(BitSelect);
}
// Return a call to the implementation function
Builder.SetInsertPoint(CI->getParent(), CI);
CallInst *NewCI = Builder.CreateCall3(F, CI->getOperand(1),
CI->getOperand(2), CI->getOperand(3));
NewCI->setName(CI->getName());
return NewCI;
}
/// 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) {
IRBuilder<> Builder;
// 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 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
Builder.SetInsertPoint(entry);
// First, get the number of bits that we're placing as an i32
Value* is_forward = Builder.CreateICmpULT(Lo, Hi);
Value* Hi_pn = Builder.CreateSelect(is_forward, Hi, Lo);
Value* Lo_pn = Builder.CreateSelect(is_forward, Lo, Hi);
Value* NumBits = Builder.CreateSub(Hi_pn, Lo_pn);
NumBits = Builder.CreateAdd(NumBits, One);
// Now, convert Lo and Hi to ValTy bit width
Lo = Builder.CreateIntCast(Lo_pn, ValTy, /* isSigned */ false);
// Determine if the replacement bits are larger than the number of bits we
// are replacing and deal with it.
Value* is_large = Builder.CreateICmpULT(NumBits, RepBitWidth);
Builder.CreateCondBr(is_large, large, small);
// BASIC BLOCK: large
Builder.SetInsertPoint(large);
Value* MaskBits = Builder.CreateSub(RepBitWidth, NumBits);
MaskBits = Builder.CreateIntCast(MaskBits, RepMask->getType(),
/* isSigned */ false);
Value* Mask1 = Builder.CreateLShr(RepMask, MaskBits);
Value* Rep2 = Builder.CreateAnd(Mask1, Rep);
Builder.CreateBr(small);
// BASIC BLOCK: small
Builder.SetInsertPoint(small);
PHINode* Rep3 = Builder.CreatePHI(RepTy);
Rep3->reserveOperandSpace(2);
Rep3->addIncoming(Rep2, large);
Rep3->addIncoming(Rep, entry);
Value* Rep4 = Builder.CreateIntCast(Rep3, ValTy, /* isSigned */ false);
Builder.CreateCondBr(is_forward, result, reverse);
// BASIC BLOCK: reverse (reverses the bits of the replacement)
Builder.SetInsertPoint(reverse);
// 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 = Builder.CreatePHI(Type::Int32Ty, "count");
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 = Builder.CreatePHI(Val->getType(), "val");
BitsToShift->reserveOperandSpace(2);
BitsToShift->addIncoming(Rep4, small);
// Get the result of the last computation or zero on first iteration
PHINode *RRes = Builder.CreatePHI(Val->getType(), "rres");
RRes->reserveOperandSpace(2);
RRes->addIncoming(ValZero, small);
// Decrement the loop counter by one
Value *Decr = Builder.CreateSub(Count, One);
Count->addIncoming(Decr, reverse);
// Get the bit that we want to move into the result
Value *Bit = Builder.CreateAnd(BitsToShift, ValOne);
// Compute the new value of the bits to shift for the next iteration.
Value *NewVal = Builder.CreateLShr(BitsToShift, ValOne);
BitsToShift->addIncoming(NewVal, reverse);
// Shift the bit we extracted into the low bit of the result.
Value *NewRes = Builder.CreateShl(RRes, ValOne);
NewRes = Builder.CreateOr(NewRes, Bit);
RRes->addIncoming(NewRes, reverse);
// Terminate loop if we've moved all the bits.
Value *Cond = Builder.CreateICmpEQ(Decr, Zero);
Builder.CreateCondBr(Cond, result, reverse);
// BASIC BLOCK: result
Builder.SetInsertPoint(result);
PHINode *Rplcmnt = Builder.CreatePHI(Val->getType());
Rplcmnt->reserveOperandSpace(2);
Rplcmnt->addIncoming(NewRes, reverse);
Rplcmnt->addIncoming(Rep4, small);
Value* t0 = Builder.CreateIntCast(NumBits, ValTy, /* isSigned */ false);
Value* t1 = Builder.CreateShl(ValMask, Lo);
Value* t2 = Builder.CreateNot(t1);
Value* t3 = Builder.CreateShl(t1, t0);
Value* t4 = Builder.CreateOr(t2, t3);
Value* t5 = Builder.CreateAnd(t4, Val);
Value* t6 = Builder.CreateShl(Rplcmnt, Lo);
Value* Rslt = Builder.CreateOr(t5, t6, "part_set");
Builder.CreateRet(Rslt);
}
// Return a call to the implementation function
Builder.SetInsertPoint(CI->getParent(), CI);
CallInst *NewCI = Builder.CreateCall4(F, CI->getOperand(1),
CI->getOperand(2), CI->getOperand(3),
CI->getOperand(4));
NewCI->setName(CI->getName());
return NewCI;
}
static void ReplaceFPIntrinsicWithCall(CallInst *CI, 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);
break;
case Type::DoubleTyID:
ReplaceCallWith(Dname, CI, CI->op_begin() + 1, CI->op_end(),
Type::DoubleTy);
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());
break;
}
}
void IntrinsicLowering::LowerIntrinsicCall(CallInst *CI) {
IRBuilder<> Builder(CI->getParent(), 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: {
Value *V = ReplaceCallWith("setjmp", CI, CI->op_begin() + 1, CI->op_end(),
Type::Int32Ty);
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: {
ReplaceCallWith("longjmp", CI, CI->op_begin() + 1, CI->op_end(),
Type::VoidTy);
break;
}
case Intrinsic::siglongjmp: {
// Insert the call to abort
ReplaceCallWith("abort", CI, CI->op_end(), CI->op_end(),
Type::VoidTy);
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 = Builder.CreateNot(Src);
NotSrc->setName(Src->getName() + ".not");
Value *SrcM1 = ConstantInt::get(Src->getType(), 1);
SrcM1 = Builder.CreateSub(Src, SrcM1);
Src = LowerCTPOP(Builder.CreateAnd(NotSrc, SrcM1), 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: {
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: {
const IntegerType *IntPtr = TD.getIntPtrType();
Value *Size = Builder.CreateIntCast(CI->getOperand(3), IntPtr,
/* isSigned */ false);
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());
break;
}
case Intrinsic::memmove: {
const IntegerType *IntPtr = TD.getIntPtrType();
Value *Size = Builder.CreateIntCast(CI->getOperand(3), IntPtr,
/* isSigned */ false);
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());
break;
}
case Intrinsic::memset: {
const IntegerType *IntPtr = TD.getIntPtrType();
Value *Size = Builder.CreateIntCast(CI->getOperand(3), IntPtr,
/* isSigned */ false);
Value *Ops[3];
Ops[0] = CI->getOperand(1);
// Extend the amount to i32.
Ops[1] = Builder.CreateIntCast(CI->getOperand(2), Type::Int32Ty,
/* isSigned */ false);
Ops[2] = Size;
ReplaceCallWith("memset", CI, Ops, Ops+3, CI->getOperand(1)->getType());
break;
}
case Intrinsic::sqrt: {
ReplaceFPIntrinsicWithCall(CI, "sqrtf", "sqrt", "sqrtl");
break;
}
case Intrinsic::log: {
ReplaceFPIntrinsicWithCall(CI, "logf", "log", "logl");
break;
}
case Intrinsic::log2: {
ReplaceFPIntrinsicWithCall(CI, "log2f", "log2", "log2l");
break;
}
case Intrinsic::log10: {
ReplaceFPIntrinsicWithCall(CI, "log10f", "log10", "log10l");
break;
}
case Intrinsic::exp: {
ReplaceFPIntrinsicWithCall(CI, "expf", "exp", "expl");
break;
}
case Intrinsic::exp2: {
ReplaceFPIntrinsicWithCall(CI, "exp2f", "exp2", "exp2l");
break;
}
case Intrinsic::pow: {
ReplaceFPIntrinsicWithCall(CI, "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();
}