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llvm-mirror/lib/CodeGen/IntrinsicLowering.cpp
Chandler Carruth ae65e281f3 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00

612 lines
22 KiB
C++

//===-- 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;
template <class ArgIt>
static void EnsureFunctionExists(Module &M, const char *Name,
ArgIt ArgBegin, ArgIt ArgEnd,
Type *RetTy) {
// Insert a correctly-typed definition now.
std::vector<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::getFloatTy(M.getContext()));
break;
case Type::DoubleTyID:
EnsureFunctionExists(M, DName, Fn.arg_begin(), Fn.arg_end(),
Type::getDoubleTy(M.getContext()));
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;
}
}
/// 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());
Constant* 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
void IntrinsicLowering::AddPrototypes(Module &M) {
LLVMContext &Context = M.getContext();
for (auto &F : M)
if (F.isDeclaration() && !F.use_empty())
switch (F.getIntrinsicID()) {
default: break;
case Intrinsic::setjmp:
EnsureFunctionExists(M, "setjmp", F.arg_begin(), F.arg_end(),
Type::getInt32Ty(M.getContext()));
break;
case Intrinsic::longjmp:
EnsureFunctionExists(M, "longjmp", F.arg_begin(), F.arg_end(),
Type::getVoidTy(M.getContext()));
break;
case Intrinsic::siglongjmp:
EnsureFunctionExists(M, "abort", F.arg_end(), F.arg_end(),
Type::getVoidTy(M.getContext()));
break;
case Intrinsic::memcpy:
M.getOrInsertFunction("memcpy",
Type::getInt8PtrTy(Context),
Type::getInt8PtrTy(Context),
Type::getInt8PtrTy(Context),
DL.getIntPtrType(Context));
break;
case Intrinsic::memmove:
M.getOrInsertFunction("memmove",
Type::getInt8PtrTy(Context),
Type::getInt8PtrTy(Context),
Type::getInt8PtrTy(Context),
DL.getIntPtrType(Context));
break;
case Intrinsic::memset:
M.getOrInsertFunction("memset",
Type::getInt8PtrTy(Context),
Type::getInt8PtrTy(Context),
Type::getInt32Ty(M.getContext()),
DL.getIntPtrType(Context));
break;
case Intrinsic::sqrt:
EnsureFPIntrinsicsExist(M, F, "sqrtf", "sqrt", "sqrtl");
break;
case Intrinsic::sin:
EnsureFPIntrinsicsExist(M, F, "sinf", "sin", "sinl");
break;
case Intrinsic::cos:
EnsureFPIntrinsicsExist(M, F, "cosf", "cos", "cosl");
break;
case Intrinsic::pow:
EnsureFPIntrinsicsExist(M, F, "powf", "pow", "powl");
break;
case Intrinsic::log:
EnsureFPIntrinsicsExist(M, F, "logf", "log", "logl");
break;
case Intrinsic::log2:
EnsureFPIntrinsicsExist(M, F, "log2f", "log2", "log2l");
break;
case Intrinsic::log10:
EnsureFPIntrinsicsExist(M, F, "log10f", "log10", "log10l");
break;
case Intrinsic::exp:
EnsureFPIntrinsicsExist(M, F, "expf", "exp", "expl");
break;
case Intrinsic::exp2:
EnsureFPIntrinsicsExist(M, F, "exp2f", "exp2", "exp2l");
break;
}
}
/// 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();
Constant *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;
}