| //===-- 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(); |
| } |