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llvm-6502/lib/CodeGen/IntrinsicLowering.cpp
Zhou Sheng 02031c0ff8 Make LowerCTPOP() support arbitrary bitwidth integer type. 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37397 91177308-0d34-0410-b5e6-96231b3b80d8
2007-06-02 04:10:33 +00:00

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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 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"
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));
}
/// 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> Operands(ArgBegin, ArgEnd);
CallInst *NewCI = new CallInst(FCache, &Operands[0], Operands.size(),
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_i32:
case Intrinsic::memcpy_i64:
M.getOrInsertFunction("memcpy", PointerType::get(Type::Int8Ty),
PointerType::get(Type::Int8Ty),
PointerType::get(Type::Int8Ty),
TD.getIntPtrType(), (Type *)0);
break;
case Intrinsic::memmove_i32:
case Intrinsic::memmove_i64:
M.getOrInsertFunction("memmove", PointerType::get(Type::Int8Ty),
PointerType::get(Type::Int8Ty),
PointerType::get(Type::Int8Ty),
TD.getIntPtrType(), (Type *)0);
break;
case Intrinsic::memset_i32:
case Intrinsic::memset_i64:
M.getOrInsertFunction("memset", PointerType::get(Type::Int8Ty),
PointerType::get(Type::Int8Ty), Type::Int32Ty,
TD.getIntPtrType(), (Type *)0);
break;
case Intrinsic::sqrt_f32:
case Intrinsic::sqrt_f64:
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;
}
}
/// 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, Tmp3, "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 CastInst::createIntegerCast(Count, Type::Int32Ty, false, "ctpop", IP);
}
/// 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::WeakLinkage);
// 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 = new BasicBlock("entry", F);
BasicBlock *RevSize = new BasicBlock("revsize", CurBB->getParent());
BasicBlock *FwdSize = new BasicBlock("fwdsize", CurBB->getParent());
BasicBlock *Compute = new BasicBlock("compute", CurBB->getParent());
BasicBlock *Reverse = new BasicBlock("reverse", CurBB->getParent());
BasicBlock *RsltBlk = new BasicBlock("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);
new BranchInst(RevSize, FwdSize, Cmp, CurBB);
// First, copmute the number of bits in the forward case.
Instruction* FBitSize =
BinaryOperator::createSub(Hi, Lo,"fbits", FwdSize);
new BranchInst(Compute, FwdSize);
// Second, compute the number of bits in the reverse case.
Instruction* RBitSize =
BinaryOperator::createSub(Lo, Hi, "rbits", RevSize);
new BranchInst(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 = new PHINode(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 = new PHINode(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);
new BranchInst(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 = new PHINode(Val->getType(), "count", Reverse);
Count->reserveOperandSpace(2);
Count->addIncoming(BitSizePlusOne, Compute);
// Next, get the value that we are shifting.
PHINode *BitsToShift = new PHINode(Val->getType(), "val", Reverse);
BitsToShift->reserveOperandSpace(2);
BitsToShift->addIncoming(FRes, Compute);
// Finally, get the result of the last computation
PHINode *RRes = new PHINode(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);
new BranchInst(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 = new PHINode(Val->getType(), "part_select", CurBB);
BitSelect->reserveOperandSpace(2);
BitSelect->addIncoming(FRes, Compute);
BitSelect->addIncoming(NewRes, Reverse);
new ReturnInst(BitSelect, CurBB);
}
// Return a call to the implementation function
Value *Args[] = {
CI->getOperand(1),
CI->getOperand(2),
CI->getOperand(3)
};
return new CallInst(F, Args, sizeof(Args)/sizeof(Args[0]), 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::WeakLinkage);
// 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 = new BasicBlock("entry", F, 0);
BasicBlock* large = new BasicBlock("large", F, 0);
BasicBlock* small = new BasicBlock("small", F, 0);
BasicBlock* reverse = new BasicBlock("reverse", F, 0);
BasicBlock* result = new BasicBlock("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 = new SelectInst(is_forward, Hi, Lo, "", entry);
SelectInst* Lo_pn = new SelectInst(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);
}
// 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);
new BranchInst(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);
new BranchInst(small, large);
// BASIC BLOCK: small
PHINode* Rep3 = new PHINode(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);
new BranchInst(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 = new PHINode(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 = new PHINode(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 = new PHINode(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);
new BranchInst(result, reverse, Cond, reverse);
// BASIC BLOCK: result
PHINode *Rplcmnt = new PHINode(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);
new ReturnInst(Rslt, result);
}
// Return a call to the implementation function
Value *Args[] = {
CI->getOperand(1),
CI->getOperand(2),
CI->getOperand(3),
CI->getOperand(4)
};
return new CallInst(F, Args, sizeof(Args)/sizeof(Args[0]), CI->getName(), CI);
}
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:
case Intrinsic::eh_exception:
case Intrinsic::eh_selector:
case Intrinsic::eh_filter:
break; // Simply strip out debugging and eh intrinsics
case Intrinsic::memcpy_i32:
case Intrinsic::memcpy_i64: {
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_i32:
case Intrinsic::memmove_i64: {
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_i32:
case Intrinsic::memset_i64: {
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_f32: {
static Constant *sqrtfFCache = 0;
ReplaceCallWith("sqrtf", CI, CI->op_begin()+1, CI->op_end(),
Type::FloatTy, sqrtfFCache);
break;
}
case Intrinsic::sqrt_f64: {
static Constant *sqrtFCache = 0;
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();
}
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