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Diffstat (limited to 'llvm/lib/CodeGen/IntrinsicLowering.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/IntrinsicLowering.cpp | 509 |
1 files changed, 509 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/IntrinsicLowering.cpp b/llvm/lib/CodeGen/IntrinsicLowering.cpp new file mode 100644 index 000000000000..8cbd8bcaeabb --- /dev/null +++ b/llvm/lib/CodeGen/IntrinsicLowering.cpp @@ -0,0 +1,509 @@ +//===-- IntrinsicLowering.cpp - Intrinsic Lowering default implementation -===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file implements the IntrinsicLowering class. +// +//===----------------------------------------------------------------------===// + +#include "llvm/CodeGen/IntrinsicLowering.h" +#include "llvm/ADT/SmallVector.h" +#include "llvm/IR/CallSite.h" +#include "llvm/IR/Constants.h" +#include "llvm/IR/DataLayout.h" +#include "llvm/IR/DerivedTypes.h" +#include "llvm/IR/IRBuilder.h" +#include "llvm/IR/Module.h" +#include "llvm/IR/Type.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/raw_ostream.h" +using namespace llvm; + +/// 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, but 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, + 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->getModule(); + // Get or insert the definition now. + std::vector<Type *> ParamTys; + for (ArgIt I = ArgBegin; I != ArgEnd; ++I) + ParamTys.push_back((*I)->getType()); + FunctionCallee FCache = + M->getOrInsertFunction(NewFn, FunctionType::get(RetTy, ParamTys, false)); + + IRBuilder<> Builder(CI->getParent(), CI->getIterator()); + SmallVector<Value *, 8> Args(ArgBegin, ArgEnd); + CallInst *NewCI = Builder.CreateCall(FCache, Args); + NewCI->setName(CI->getName()); + if (!CI->use_empty()) + CI->replaceAllUsesWith(NewCI); + return NewCI; +} + +// VisualStudio defines setjmp as _setjmp +#if defined(_MSC_VER) && defined(setjmp) && \ + !defined(setjmp_undefined_for_msvc) +# pragma push_macro("setjmp") +# undef setjmp +# define setjmp_undefined_for_msvc +#endif + +/// Emit the code to lower bswap of V before the specified instruction IP. +static Value *LowerBSWAP(LLVMContext &Context, Value *V, Instruction *IP) { + assert(V->getType()->isIntOrIntVectorTy() && "Can't bswap a non-integer type!"); + + unsigned BitSize = V->getType()->getScalarSizeInBits(); + + IRBuilder<> Builder(IP); + + switch(BitSize) { + default: llvm_unreachable("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(V->getType(), 0xFF0000), + "bswap.and3"); + Tmp2 = Builder.CreateAnd(Tmp2, + ConstantInt::get(V->getType(), 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(V->getType(), + 0xFF000000000000ULL), + "bswap.and7"); + Tmp6 = Builder.CreateAnd(Tmp6, + ConstantInt::get(V->getType(), + 0xFF0000000000ULL), + "bswap.and6"); + Tmp5 = Builder.CreateAnd(Tmp5, + ConstantInt::get(V->getType(), + 0xFF00000000ULL), + "bswap.and5"); + Tmp4 = Builder.CreateAnd(Tmp4, + ConstantInt::get(V->getType(), + 0xFF000000ULL), + "bswap.and4"); + Tmp3 = Builder.CreateAnd(Tmp3, + ConstantInt::get(V->getType(), + 0xFF0000ULL), + "bswap.and3"); + Tmp2 = Builder.CreateAnd(Tmp2, + ConstantInt::get(V->getType(), + 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; +} + +/// Emit the code to lower ctpop of V before the specified instruction IP. +static Value *LowerCTPOP(LLVMContext &Context, Value *V, Instruction *IP) { + assert(V->getType()->isIntegerTy() && "Can't ctpop a non-integer type!"); + + static const uint64_t MaskValues[6] = { + 0x5555555555555555ULL, 0x3333333333333333ULL, + 0x0F0F0F0F0F0F0F0FULL, 0x00FF00FF00FF00FFULL, + 0x0000FFFF0000FFFFULL, 0x00000000FFFFFFFFULL + }; + + IRBuilder<> Builder(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; +} + +/// Emit the code to lower ctlz of V before the specified instruction IP. +static Value *LowerCTLZ(LLVMContext &Context, Value *V, Instruction *IP) { + + IRBuilder<> Builder(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(Context, V, IP); +} + +static void ReplaceFPIntrinsicWithCall(CallInst *CI, const char *Fname, + const char *Dname, + const char *LDname) { + CallSite CS(CI); + switch (CI->getArgOperand(0)->getType()->getTypeID()) { + default: llvm_unreachable("Invalid type in intrinsic"); + case Type::FloatTyID: + ReplaceCallWith(Fname, CI, CS.arg_begin(), CS.arg_end(), + Type::getFloatTy(CI->getContext())); + break; + case Type::DoubleTyID: + ReplaceCallWith(Dname, CI, CS.arg_begin(), CS.arg_end(), + Type::getDoubleTy(CI->getContext())); + break; + case Type::X86_FP80TyID: + case Type::FP128TyID: + case Type::PPC_FP128TyID: + ReplaceCallWith(LDname, CI, CS.arg_begin(), CS.arg_end(), + CI->getArgOperand(0)->getType()); + break; + } +} + +void IntrinsicLowering::LowerIntrinsicCall(CallInst *CI) { + IRBuilder<> Builder(CI); + LLVMContext &Context = CI->getContext(); + + const Function *Callee = CI->getCalledFunction(); + assert(Callee && "Cannot lower an indirect call!"); + + CallSite CS(CI); + switch (Callee->getIntrinsicID()) { + case Intrinsic::not_intrinsic: + report_fatal_error("Cannot lower a call to a non-intrinsic function '"+ + Callee->getName() + "'!"); + default: + report_fatal_error("Code generator does not support intrinsic function '"+ + Callee->getName()+"'!"); + + case Intrinsic::expect: { + // Just replace __builtin_expect(exp, c) with EXP. + Value *V = CI->getArgOperand(0); + CI->replaceAllUsesWith(V); + break; + } + + // 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, CS.arg_begin(), CS.arg_end(), + Type::getInt32Ty(Context)); + if (!CI->getType()->isVoidTy()) + CI->replaceAllUsesWith(V); + break; + } + case Intrinsic::sigsetjmp: + if (!CI->getType()->isVoidTy()) + CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); + break; + + case Intrinsic::longjmp: { + ReplaceCallWith("longjmp", CI, CS.arg_begin(), CS.arg_end(), + Type::getVoidTy(Context)); + break; + } + + case Intrinsic::siglongjmp: { + // Insert the call to abort + ReplaceCallWith("abort", CI, CS.arg_end(), CS.arg_end(), + Type::getVoidTy(Context)); + break; + } + case Intrinsic::ctpop: + CI->replaceAllUsesWith(LowerCTPOP(Context, CI->getArgOperand(0), CI)); + break; + + case Intrinsic::bswap: + CI->replaceAllUsesWith(LowerBSWAP(Context, CI->getArgOperand(0), CI)); + break; + + case Intrinsic::ctlz: + CI->replaceAllUsesWith(LowerCTLZ(Context, CI->getArgOperand(0), CI)); + break; + + case Intrinsic::cttz: { + // cttz(x) -> ctpop(~X & (X-1)) + Value *Src = CI->getArgOperand(0); + Value *NotSrc = Builder.CreateNot(Src); + NotSrc->setName(Src->getName() + ".not"); + Value *SrcM1 = ConstantInt::get(Src->getType(), 1); + SrcM1 = Builder.CreateSub(Src, SrcM1); + Src = LowerCTPOP(Context, Builder.CreateAnd(NotSrc, SrcM1), CI); + CI->replaceAllUsesWith(Src); + break; + } + + case Intrinsic::stacksave: + case Intrinsic::stackrestore: { + if (!Warned) + errs() << "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::get_dynamic_area_offset: + errs() << "WARNING: this target does not support the custom llvm.get." + "dynamic.area.offset. It is being lowered to a constant 0\n"; + // Just lower it to a constant 0 because for most targets + // @llvm.get.dynamic.area.offset is lowered to zero. + CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 0)); + break; + case Intrinsic::returnaddress: + case Intrinsic::frameaddress: + errs() << "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::addressofreturnaddress: + errs() << "WARNING: this target does not support the " + "llvm.addressofreturnaddress 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: { + errs() << "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::getInt64Ty(Context), 0)); + break; + } + + case Intrinsic::dbg_declare: + case Intrinsic::dbg_label: + break; // Simply strip out debugging intrinsics + + case Intrinsic::eh_typeid_for: + // Return something different to eh_selector. + CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1)); + break; + + case Intrinsic::annotation: + case Intrinsic::ptr_annotation: + // Just drop the annotation, but forward the value + CI->replaceAllUsesWith(CI->getOperand(0)); + break; + + case Intrinsic::assume: + case Intrinsic::var_annotation: + break; // Strip out these intrinsics + + case Intrinsic::memcpy: { + Type *IntPtr = DL.getIntPtrType(Context); + Value *Size = Builder.CreateIntCast(CI->getArgOperand(2), IntPtr, + /* isSigned */ false); + Value *Ops[3]; + Ops[0] = CI->getArgOperand(0); + Ops[1] = CI->getArgOperand(1); + Ops[2] = Size; + ReplaceCallWith("memcpy", CI, Ops, Ops+3, CI->getArgOperand(0)->getType()); + break; + } + case Intrinsic::memmove: { + Type *IntPtr = DL.getIntPtrType(Context); + Value *Size = Builder.CreateIntCast(CI->getArgOperand(2), IntPtr, + /* isSigned */ false); + Value *Ops[3]; + Ops[0] = CI->getArgOperand(0); + Ops[1] = CI->getArgOperand(1); + Ops[2] = Size; + ReplaceCallWith("memmove", CI, Ops, Ops+3, CI->getArgOperand(0)->getType()); + break; + } + case Intrinsic::memset: { + Value *Op0 = CI->getArgOperand(0); + Type *IntPtr = DL.getIntPtrType(Op0->getType()); + Value *Size = Builder.CreateIntCast(CI->getArgOperand(2), IntPtr, + /* isSigned */ false); + Value *Ops[3]; + Ops[0] = Op0; + // Extend the amount to i32. + Ops[1] = Builder.CreateIntCast(CI->getArgOperand(1), + Type::getInt32Ty(Context), + /* isSigned */ false); + Ops[2] = Size; + ReplaceCallWith("memset", CI, Ops, Ops+3, CI->getArgOperand(0)->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::sin: { + ReplaceFPIntrinsicWithCall(CI, "sinf", "sin", "sinl"); + break; + } + case Intrinsic::cos: { + ReplaceFPIntrinsicWithCall(CI, "cosf", "cos", "cosl"); + break; + } + case Intrinsic::floor: { + ReplaceFPIntrinsicWithCall(CI, "floorf", "floor", "floorl"); + break; + } + case Intrinsic::ceil: { + ReplaceFPIntrinsicWithCall(CI, "ceilf", "ceil", "ceill"); + break; + } + case Intrinsic::trunc: { + ReplaceFPIntrinsicWithCall(CI, "truncf", "trunc", "truncl"); + break; + } + case Intrinsic::round: { + ReplaceFPIntrinsicWithCall(CI, "roundf", "round", "roundl"); + break; + } + case Intrinsic::copysign: { + ReplaceFPIntrinsicWithCall(CI, "copysignf", "copysign", "copysignl"); + break; + } + case Intrinsic::flt_rounds: + // Lower to "round to the nearest" + if (!CI->getType()->isVoidTy()) + CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1)); + break; + case Intrinsic::invariant_start: + case Intrinsic::lifetime_start: + // Discard region information. + CI->replaceAllUsesWith(UndefValue::get(CI->getType())); + break; + case Intrinsic::invariant_end: + case Intrinsic::lifetime_end: + // Discard region information. + break; + } + + assert(CI->use_empty() && + "Lowering should have eliminated any uses of the intrinsic call!"); + CI->eraseFromParent(); +} + +bool IntrinsicLowering::LowerToByteSwap(CallInst *CI) { + // Verify this is a simple bswap. + if (CI->getNumArgOperands() != 1 || + CI->getType() != CI->getArgOperand(0)->getType() || + !CI->getType()->isIntegerTy()) + return false; + + IntegerType *Ty = dyn_cast<IntegerType>(CI->getType()); + if (!Ty) + return false; + + // Okay, we can do this xform, do so now. + Module *M = CI->getModule(); + Function *Int = Intrinsic::getDeclaration(M, Intrinsic::bswap, Ty); + + Value *Op = CI->getArgOperand(0); + Op = CallInst::Create(Int, Op, CI->getName(), CI); + + CI->replaceAllUsesWith(Op); + CI->eraseFromParent(); + return true; +} |