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CGBuiltin.cpp
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CGBuiltin.cpp
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//===---- CGBuiltin.cpp - Emit LLVM Code for builtins ---------------------===//
//
// 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 contains code to emit Builtin calls as LLVM code.
//
//===----------------------------------------------------------------------===//
#include "ABIInfo.h"
#include "CGCUDARuntime.h"
#include "CGCXXABI.h"
#include "CGObjCRuntime.h"
#include "CGOpenCLRuntime.h"
#include "CGRecordLayout.h"
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "ConstantEmitter.h"
#include "PatternInit.h"
#include "TargetInfo.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Attr.h"
#include "clang/AST/Decl.h"
#include "clang/AST/OSLog.h"
#include "clang/AST/OperationKinds.h"
#include "clang/Basic/TargetBuiltins.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Basic/TargetOptions.h"
#include "clang/CodeGen/CGFunctionInfo.h"
#include "clang/Frontend/FrontendDiagnostic.h"
#include "llvm/ADT/APFloat.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/FloatingPointMode.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/IntrinsicsAArch64.h"
#include "llvm/IR/IntrinsicsAMDGPU.h"
#include "llvm/IR/IntrinsicsARM.h"
#include "llvm/IR/IntrinsicsBPF.h"
#include "llvm/IR/IntrinsicsDirectX.h"
#include "llvm/IR/IntrinsicsHexagon.h"
#include "llvm/IR/IntrinsicsNVPTX.h"
#include "llvm/IR/IntrinsicsPowerPC.h"
#include "llvm/IR/IntrinsicsR600.h"
#include "llvm/IR/IntrinsicsRISCV.h"
#include "llvm/IR/IntrinsicsS390.h"
#include "llvm/IR/IntrinsicsVE.h"
#include "llvm/IR/IntrinsicsWebAssembly.h"
#include "llvm/IR/IntrinsicsX86.h"
#include "llvm/IR/MDBuilder.h"
#include "llvm/IR/MatrixBuilder.h"
#include "llvm/Support/ConvertUTF.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/ScopedPrinter.h"
#include "llvm/TargetParser/AArch64TargetParser.h"
#include "llvm/TargetParser/X86TargetParser.h"
#include <optional>
#include <sstream>
using namespace clang;
using namespace CodeGen;
using namespace llvm;
static void initializeAlloca(CodeGenFunction &CGF, AllocaInst *AI, Value *Size,
Align AlignmentInBytes) {
ConstantInt *Byte;
switch (CGF.getLangOpts().getTrivialAutoVarInit()) {
case LangOptions::TrivialAutoVarInitKind::Uninitialized:
// Nothing to initialize.
return;
case LangOptions::TrivialAutoVarInitKind::Zero:
Byte = CGF.Builder.getInt8(0x00);
break;
case LangOptions::TrivialAutoVarInitKind::Pattern: {
llvm::Type *Int8 = llvm::IntegerType::getInt8Ty(CGF.CGM.getLLVMContext());
Byte = llvm::dyn_cast<llvm::ConstantInt>(
initializationPatternFor(CGF.CGM, Int8));
break;
}
}
if (CGF.CGM.stopAutoInit())
return;
auto *I = CGF.Builder.CreateMemSet(AI, Byte, Size, AlignmentInBytes);
I->addAnnotationMetadata("auto-init");
}
/// getBuiltinLibFunction - Given a builtin id for a function like
/// "__builtin_fabsf", return a Function* for "fabsf".
llvm::Constant *CodeGenModule::getBuiltinLibFunction(const FunctionDecl *FD,
unsigned BuiltinID) {
assert(Context.BuiltinInfo.isLibFunction(BuiltinID));
// Get the name, skip over the __builtin_ prefix (if necessary).
StringRef Name;
GlobalDecl D(FD);
// TODO: This list should be expanded or refactored after all GCC-compatible
// std libcall builtins are implemented.
static SmallDenseMap<unsigned, StringRef, 64> F128Builtins{
{Builtin::BI__builtin___fprintf_chk, "__fprintf_chkieee128"},
{Builtin::BI__builtin___printf_chk, "__printf_chkieee128"},
{Builtin::BI__builtin___snprintf_chk, "__snprintf_chkieee128"},
{Builtin::BI__builtin___sprintf_chk, "__sprintf_chkieee128"},
{Builtin::BI__builtin___vfprintf_chk, "__vfprintf_chkieee128"},
{Builtin::BI__builtin___vprintf_chk, "__vprintf_chkieee128"},
{Builtin::BI__builtin___vsnprintf_chk, "__vsnprintf_chkieee128"},
{Builtin::BI__builtin___vsprintf_chk, "__vsprintf_chkieee128"},
{Builtin::BI__builtin_fprintf, "__fprintfieee128"},
{Builtin::BI__builtin_printf, "__printfieee128"},
{Builtin::BI__builtin_snprintf, "__snprintfieee128"},
{Builtin::BI__builtin_sprintf, "__sprintfieee128"},
{Builtin::BI__builtin_vfprintf, "__vfprintfieee128"},
{Builtin::BI__builtin_vprintf, "__vprintfieee128"},
{Builtin::BI__builtin_vsnprintf, "__vsnprintfieee128"},
{Builtin::BI__builtin_vsprintf, "__vsprintfieee128"},
{Builtin::BI__builtin_fscanf, "__fscanfieee128"},
{Builtin::BI__builtin_scanf, "__scanfieee128"},
{Builtin::BI__builtin_sscanf, "__sscanfieee128"},
{Builtin::BI__builtin_vfscanf, "__vfscanfieee128"},
{Builtin::BI__builtin_vscanf, "__vscanfieee128"},
{Builtin::BI__builtin_vsscanf, "__vsscanfieee128"},
{Builtin::BI__builtin_nexttowardf128, "__nexttowardieee128"},
};
// The AIX library functions frexpl, ldexpl, and modfl are for 128-bit
// IBM 'long double' (i.e. __ibm128). Map to the 'double' versions
// if it is 64-bit 'long double' mode.
static SmallDenseMap<unsigned, StringRef, 4> AIXLongDouble64Builtins{
{Builtin::BI__builtin_frexpl, "frexp"},
{Builtin::BI__builtin_ldexpl, "ldexp"},
{Builtin::BI__builtin_modfl, "modf"},
};
// If the builtin has been declared explicitly with an assembler label,
// use the mangled name. This differs from the plain label on platforms
// that prefix labels.
if (FD->hasAttr<AsmLabelAttr>())
Name = getMangledName(D);
else {
// TODO: This mutation should also be applied to other targets other than
// PPC, after backend supports IEEE 128-bit style libcalls.
if (getTriple().isPPC64() &&
&getTarget().getLongDoubleFormat() == &llvm::APFloat::IEEEquad() &&
F128Builtins.contains(BuiltinID))
Name = F128Builtins[BuiltinID];
else if (getTriple().isOSAIX() &&
&getTarget().getLongDoubleFormat() ==
&llvm::APFloat::IEEEdouble() &&
AIXLongDouble64Builtins.contains(BuiltinID))
Name = AIXLongDouble64Builtins[BuiltinID];
else
Name = Context.BuiltinInfo.getName(BuiltinID).substr(10);
}
llvm::FunctionType *Ty =
cast<llvm::FunctionType>(getTypes().ConvertType(FD->getType()));
return GetOrCreateLLVMFunction(Name, Ty, D, /*ForVTable=*/false);
}
/// Emit the conversions required to turn the given value into an
/// integer of the given size.
static Value *EmitToInt(CodeGenFunction &CGF, llvm::Value *V,
QualType T, llvm::IntegerType *IntType) {
V = CGF.EmitToMemory(V, T);
if (V->getType()->isPointerTy())
return CGF.Builder.CreatePtrToInt(V, IntType);
assert(V->getType() == IntType);
return V;
}
static Value *EmitFromInt(CodeGenFunction &CGF, llvm::Value *V,
QualType T, llvm::Type *ResultType) {
V = CGF.EmitFromMemory(V, T);
if (ResultType->isPointerTy())
return CGF.Builder.CreateIntToPtr(V, ResultType);
assert(V->getType() == ResultType);
return V;
}
static Address CheckAtomicAlignment(CodeGenFunction &CGF, const CallExpr *E) {
ASTContext &Ctx = CGF.getContext();
Address Ptr = CGF.EmitPointerWithAlignment(E->getArg(0));
unsigned Bytes = Ptr.getElementType()->isPointerTy()
? Ctx.getTypeSizeInChars(Ctx.VoidPtrTy).getQuantity()
: Ptr.getElementType()->getScalarSizeInBits() / 8;
unsigned Align = Ptr.getAlignment().getQuantity();
if (Align % Bytes != 0) {
DiagnosticsEngine &Diags = CGF.CGM.getDiags();
Diags.Report(E->getBeginLoc(), diag::warn_sync_op_misaligned);
// Force address to be at least naturally-aligned.
return Ptr.withAlignment(CharUnits::fromQuantity(Bytes));
}
return Ptr;
}
/// Utility to insert an atomic instruction based on Intrinsic::ID
/// and the expression node.
static Value *MakeBinaryAtomicValue(
CodeGenFunction &CGF, llvm::AtomicRMWInst::BinOp Kind, const CallExpr *E,
AtomicOrdering Ordering = AtomicOrdering::SequentiallyConsistent) {
QualType T = E->getType();
assert(E->getArg(0)->getType()->isPointerType());
assert(CGF.getContext().hasSameUnqualifiedType(T,
E->getArg(0)->getType()->getPointeeType()));
assert(CGF.getContext().hasSameUnqualifiedType(T, E->getArg(1)->getType()));
Address DestAddr = CheckAtomicAlignment(CGF, E);
llvm::IntegerType *IntType = llvm::IntegerType::get(
CGF.getLLVMContext(), CGF.getContext().getTypeSize(T));
llvm::Value *Val = CGF.EmitScalarExpr(E->getArg(1));
llvm::Type *ValueType = Val->getType();
Val = EmitToInt(CGF, Val, T, IntType);
llvm::Value *Result =
CGF.Builder.CreateAtomicRMW(Kind, DestAddr, Val, Ordering);
return EmitFromInt(CGF, Result, T, ValueType);
}
static Value *EmitNontemporalStore(CodeGenFunction &CGF, const CallExpr *E) {
Value *Val = CGF.EmitScalarExpr(E->getArg(0));
Address Addr = CGF.EmitPointerWithAlignment(E->getArg(1));
Val = CGF.EmitToMemory(Val, E->getArg(0)->getType());
LValue LV = CGF.MakeAddrLValue(Addr, E->getArg(0)->getType());
LV.setNontemporal(true);
CGF.EmitStoreOfScalar(Val, LV, false);
return nullptr;
}
static Value *EmitNontemporalLoad(CodeGenFunction &CGF, const CallExpr *E) {
Address Addr = CGF.EmitPointerWithAlignment(E->getArg(0));
LValue LV = CGF.MakeAddrLValue(Addr, E->getType());
LV.setNontemporal(true);
return CGF.EmitLoadOfScalar(LV, E->getExprLoc());
}
static RValue EmitBinaryAtomic(CodeGenFunction &CGF,
llvm::AtomicRMWInst::BinOp Kind,
const CallExpr *E) {
return RValue::get(MakeBinaryAtomicValue(CGF, Kind, E));
}
/// Utility to insert an atomic instruction based Intrinsic::ID and
/// the expression node, where the return value is the result of the
/// operation.
static RValue EmitBinaryAtomicPost(CodeGenFunction &CGF,
llvm::AtomicRMWInst::BinOp Kind,
const CallExpr *E,
Instruction::BinaryOps Op,
bool Invert = false) {
QualType T = E->getType();
assert(E->getArg(0)->getType()->isPointerType());
assert(CGF.getContext().hasSameUnqualifiedType(T,
E->getArg(0)->getType()->getPointeeType()));
assert(CGF.getContext().hasSameUnqualifiedType(T, E->getArg(1)->getType()));
Address DestAddr = CheckAtomicAlignment(CGF, E);
llvm::IntegerType *IntType = llvm::IntegerType::get(
CGF.getLLVMContext(), CGF.getContext().getTypeSize(T));
llvm::Value *Val = CGF.EmitScalarExpr(E->getArg(1));
llvm::Type *ValueType = Val->getType();
Val = EmitToInt(CGF, Val, T, IntType);
llvm::Value *Result = CGF.Builder.CreateAtomicRMW(
Kind, DestAddr, Val, llvm::AtomicOrdering::SequentiallyConsistent);
Result = CGF.Builder.CreateBinOp(Op, Result, Val);
if (Invert)
Result =
CGF.Builder.CreateBinOp(llvm::Instruction::Xor, Result,
llvm::ConstantInt::getAllOnesValue(IntType));
Result = EmitFromInt(CGF, Result, T, ValueType);
return RValue::get(Result);
}
/// Utility to insert an atomic cmpxchg instruction.
///
/// @param CGF The current codegen function.
/// @param E Builtin call expression to convert to cmpxchg.
/// arg0 - address to operate on
/// arg1 - value to compare with
/// arg2 - new value
/// @param ReturnBool Specifies whether to return success flag of
/// cmpxchg result or the old value.
///
/// @returns result of cmpxchg, according to ReturnBool
///
/// Note: In order to lower Microsoft's _InterlockedCompareExchange* intrinsics
/// invoke the function EmitAtomicCmpXchgForMSIntrin.
static Value *MakeAtomicCmpXchgValue(CodeGenFunction &CGF, const CallExpr *E,
bool ReturnBool) {
QualType T = ReturnBool ? E->getArg(1)->getType() : E->getType();
Address DestAddr = CheckAtomicAlignment(CGF, E);
llvm::IntegerType *IntType = llvm::IntegerType::get(
CGF.getLLVMContext(), CGF.getContext().getTypeSize(T));
Value *Cmp = CGF.EmitScalarExpr(E->getArg(1));
llvm::Type *ValueType = Cmp->getType();
Cmp = EmitToInt(CGF, Cmp, T, IntType);
Value *New = EmitToInt(CGF, CGF.EmitScalarExpr(E->getArg(2)), T, IntType);
Value *Pair = CGF.Builder.CreateAtomicCmpXchg(
DestAddr, Cmp, New, llvm::AtomicOrdering::SequentiallyConsistent,
llvm::AtomicOrdering::SequentiallyConsistent);
if (ReturnBool)
// Extract boolean success flag and zext it to int.
return CGF.Builder.CreateZExt(CGF.Builder.CreateExtractValue(Pair, 1),
CGF.ConvertType(E->getType()));
else
// Extract old value and emit it using the same type as compare value.
return EmitFromInt(CGF, CGF.Builder.CreateExtractValue(Pair, 0), T,
ValueType);
}
/// This function should be invoked to emit atomic cmpxchg for Microsoft's
/// _InterlockedCompareExchange* intrinsics which have the following signature:
/// T _InterlockedCompareExchange(T volatile *Destination,
/// T Exchange,
/// T Comparand);
///
/// Whereas the llvm 'cmpxchg' instruction has the following syntax:
/// cmpxchg *Destination, Comparand, Exchange.
/// So we need to swap Comparand and Exchange when invoking
/// CreateAtomicCmpXchg. That is the reason we could not use the above utility
/// function MakeAtomicCmpXchgValue since it expects the arguments to be
/// already swapped.
static
Value *EmitAtomicCmpXchgForMSIntrin(CodeGenFunction &CGF, const CallExpr *E,
AtomicOrdering SuccessOrdering = AtomicOrdering::SequentiallyConsistent) {
assert(E->getArg(0)->getType()->isPointerType());
assert(CGF.getContext().hasSameUnqualifiedType(
E->getType(), E->getArg(0)->getType()->getPointeeType()));
assert(CGF.getContext().hasSameUnqualifiedType(E->getType(),
E->getArg(1)->getType()));
assert(CGF.getContext().hasSameUnqualifiedType(E->getType(),
E->getArg(2)->getType()));
Address DestAddr = CheckAtomicAlignment(CGF, E);
auto *Comparand = CGF.EmitScalarExpr(E->getArg(2));
auto *Exchange = CGF.EmitScalarExpr(E->getArg(1));
// For Release ordering, the failure ordering should be Monotonic.
auto FailureOrdering = SuccessOrdering == AtomicOrdering::Release ?
AtomicOrdering::Monotonic :
SuccessOrdering;
// The atomic instruction is marked volatile for consistency with MSVC. This
// blocks the few atomics optimizations that LLVM has. If we want to optimize
// _Interlocked* operations in the future, we will have to remove the volatile
// marker.
auto *Result = CGF.Builder.CreateAtomicCmpXchg(
DestAddr, Comparand, Exchange, SuccessOrdering, FailureOrdering);
Result->setVolatile(true);
return CGF.Builder.CreateExtractValue(Result, 0);
}
// 64-bit Microsoft platforms support 128 bit cmpxchg operations. They are
// prototyped like this:
//
// unsigned char _InterlockedCompareExchange128...(
// __int64 volatile * _Destination,
// __int64 _ExchangeHigh,
// __int64 _ExchangeLow,
// __int64 * _ComparandResult);
//
// Note that Destination is assumed to be at least 16-byte aligned, despite
// being typed int64.
static Value *EmitAtomicCmpXchg128ForMSIntrin(CodeGenFunction &CGF,
const CallExpr *E,
AtomicOrdering SuccessOrdering) {
assert(E->getNumArgs() == 4);
llvm::Value *DestPtr = CGF.EmitScalarExpr(E->getArg(0));
llvm::Value *ExchangeHigh = CGF.EmitScalarExpr(E->getArg(1));
llvm::Value *ExchangeLow = CGF.EmitScalarExpr(E->getArg(2));
Address ComparandAddr = CGF.EmitPointerWithAlignment(E->getArg(3));
assert(DestPtr->getType()->isPointerTy());
assert(!ExchangeHigh->getType()->isPointerTy());
assert(!ExchangeLow->getType()->isPointerTy());
// For Release ordering, the failure ordering should be Monotonic.
auto FailureOrdering = SuccessOrdering == AtomicOrdering::Release
? AtomicOrdering::Monotonic
: SuccessOrdering;
// Convert to i128 pointers and values. Alignment is also overridden for
// destination pointer.
llvm::Type *Int128Ty = llvm::IntegerType::get(CGF.getLLVMContext(), 128);
Address DestAddr(DestPtr, Int128Ty,
CGF.getContext().toCharUnitsFromBits(128));
ComparandAddr = ComparandAddr.withElementType(Int128Ty);
// (((i128)hi) << 64) | ((i128)lo)
ExchangeHigh = CGF.Builder.CreateZExt(ExchangeHigh, Int128Ty);
ExchangeLow = CGF.Builder.CreateZExt(ExchangeLow, Int128Ty);
ExchangeHigh =
CGF.Builder.CreateShl(ExchangeHigh, llvm::ConstantInt::get(Int128Ty, 64));
llvm::Value *Exchange = CGF.Builder.CreateOr(ExchangeHigh, ExchangeLow);
// Load the comparand for the instruction.
llvm::Value *Comparand = CGF.Builder.CreateLoad(ComparandAddr);
auto *CXI = CGF.Builder.CreateAtomicCmpXchg(DestAddr, Comparand, Exchange,
SuccessOrdering, FailureOrdering);
// The atomic instruction is marked volatile for consistency with MSVC. This
// blocks the few atomics optimizations that LLVM has. If we want to optimize
// _Interlocked* operations in the future, we will have to remove the volatile
// marker.
CXI->setVolatile(true);
// Store the result as an outparameter.
CGF.Builder.CreateStore(CGF.Builder.CreateExtractValue(CXI, 0),
ComparandAddr);
// Get the success boolean and zero extend it to i8.
Value *Success = CGF.Builder.CreateExtractValue(CXI, 1);
return CGF.Builder.CreateZExt(Success, CGF.Int8Ty);
}
static Value *EmitAtomicIncrementValue(CodeGenFunction &CGF, const CallExpr *E,
AtomicOrdering Ordering = AtomicOrdering::SequentiallyConsistent) {
assert(E->getArg(0)->getType()->isPointerType());
auto *IntTy = CGF.ConvertType(E->getType());
Address DestAddr = CheckAtomicAlignment(CGF, E);
auto *Result = CGF.Builder.CreateAtomicRMW(
AtomicRMWInst::Add, DestAddr, ConstantInt::get(IntTy, 1), Ordering);
return CGF.Builder.CreateAdd(Result, ConstantInt::get(IntTy, 1));
}
static Value *EmitAtomicDecrementValue(
CodeGenFunction &CGF, const CallExpr *E,
AtomicOrdering Ordering = AtomicOrdering::SequentiallyConsistent) {
assert(E->getArg(0)->getType()->isPointerType());
auto *IntTy = CGF.ConvertType(E->getType());
Address DestAddr = CheckAtomicAlignment(CGF, E);
auto *Result = CGF.Builder.CreateAtomicRMW(
AtomicRMWInst::Sub, DestAddr, ConstantInt::get(IntTy, 1), Ordering);
return CGF.Builder.CreateSub(Result, ConstantInt::get(IntTy, 1));
}
// Build a plain volatile load.
static Value *EmitISOVolatileLoad(CodeGenFunction &CGF, const CallExpr *E) {
Value *Ptr = CGF.EmitScalarExpr(E->getArg(0));
QualType ElTy = E->getArg(0)->getType()->getPointeeType();
CharUnits LoadSize = CGF.getContext().getTypeSizeInChars(ElTy);
llvm::Type *ITy =
llvm::IntegerType::get(CGF.getLLVMContext(), LoadSize.getQuantity() * 8);
llvm::LoadInst *Load = CGF.Builder.CreateAlignedLoad(ITy, Ptr, LoadSize);
Load->setVolatile(true);
return Load;
}
// Build a plain volatile store.
static Value *EmitISOVolatileStore(CodeGenFunction &CGF, const CallExpr *E) {
Value *Ptr = CGF.EmitScalarExpr(E->getArg(0));
Value *Value = CGF.EmitScalarExpr(E->getArg(1));
QualType ElTy = E->getArg(0)->getType()->getPointeeType();
CharUnits StoreSize = CGF.getContext().getTypeSizeInChars(ElTy);
llvm::StoreInst *Store =
CGF.Builder.CreateAlignedStore(Value, Ptr, StoreSize);
Store->setVolatile(true);
return Store;
}
// Emit a simple mangled intrinsic that has 1 argument and a return type
// matching the argument type. Depending on mode, this may be a constrained
// floating-point intrinsic.
static Value *emitUnaryMaybeConstrainedFPBuiltin(CodeGenFunction &CGF,
const CallExpr *E, unsigned IntrinsicID,
unsigned ConstrainedIntrinsicID) {
llvm::Value *Src0 = CGF.EmitScalarExpr(E->getArg(0));
CodeGenFunction::CGFPOptionsRAII FPOptsRAII(CGF, E);
if (CGF.Builder.getIsFPConstrained()) {
Function *F = CGF.CGM.getIntrinsic(ConstrainedIntrinsicID, Src0->getType());
return CGF.Builder.CreateConstrainedFPCall(F, { Src0 });
} else {
Function *F = CGF.CGM.getIntrinsic(IntrinsicID, Src0->getType());
return CGF.Builder.CreateCall(F, Src0);
}
}
// Emit an intrinsic that has 2 operands of the same type as its result.
// Depending on mode, this may be a constrained floating-point intrinsic.
static Value *emitBinaryMaybeConstrainedFPBuiltin(CodeGenFunction &CGF,
const CallExpr *E, unsigned IntrinsicID,
unsigned ConstrainedIntrinsicID) {
llvm::Value *Src0 = CGF.EmitScalarExpr(E->getArg(0));
llvm::Value *Src1 = CGF.EmitScalarExpr(E->getArg(1));
if (CGF.Builder.getIsFPConstrained()) {
CodeGenFunction::CGFPOptionsRAII FPOptsRAII(CGF, E);
Function *F = CGF.CGM.getIntrinsic(ConstrainedIntrinsicID, Src0->getType());
return CGF.Builder.CreateConstrainedFPCall(F, { Src0, Src1 });
} else {
Function *F = CGF.CGM.getIntrinsic(IntrinsicID, Src0->getType());
return CGF.Builder.CreateCall(F, { Src0, Src1 });
}
}
// Has second type mangled argument.
static Value *emitBinaryExpMaybeConstrainedFPBuiltin(
CodeGenFunction &CGF, const CallExpr *E, llvm::Intrinsic::ID IntrinsicID,
llvm::Intrinsic::ID ConstrainedIntrinsicID) {
llvm::Value *Src0 = CGF.EmitScalarExpr(E->getArg(0));
llvm::Value *Src1 = CGF.EmitScalarExpr(E->getArg(1));
if (CGF.Builder.getIsFPConstrained()) {
CodeGenFunction::CGFPOptionsRAII FPOptsRAII(CGF, E);
Function *F = CGF.CGM.getIntrinsic(ConstrainedIntrinsicID,
{Src0->getType(), Src1->getType()});
return CGF.Builder.CreateConstrainedFPCall(F, {Src0, Src1});
}
Function *F =
CGF.CGM.getIntrinsic(IntrinsicID, {Src0->getType(), Src1->getType()});
return CGF.Builder.CreateCall(F, {Src0, Src1});
}
// Emit an intrinsic that has 3 operands of the same type as its result.
// Depending on mode, this may be a constrained floating-point intrinsic.
static Value *emitTernaryMaybeConstrainedFPBuiltin(CodeGenFunction &CGF,
const CallExpr *E, unsigned IntrinsicID,
unsigned ConstrainedIntrinsicID) {
llvm::Value *Src0 = CGF.EmitScalarExpr(E->getArg(0));
llvm::Value *Src1 = CGF.EmitScalarExpr(E->getArg(1));
llvm::Value *Src2 = CGF.EmitScalarExpr(E->getArg(2));
if (CGF.Builder.getIsFPConstrained()) {
CodeGenFunction::CGFPOptionsRAII FPOptsRAII(CGF, E);
Function *F = CGF.CGM.getIntrinsic(ConstrainedIntrinsicID, Src0->getType());
return CGF.Builder.CreateConstrainedFPCall(F, { Src0, Src1, Src2 });
} else {
Function *F = CGF.CGM.getIntrinsic(IntrinsicID, Src0->getType());
return CGF.Builder.CreateCall(F, { Src0, Src1, Src2 });
}
}
// Emit an intrinsic where all operands are of the same type as the result.
// Depending on mode, this may be a constrained floating-point intrinsic.
static Value *emitCallMaybeConstrainedFPBuiltin(CodeGenFunction &CGF,
unsigned IntrinsicID,
unsigned ConstrainedIntrinsicID,
llvm::Type *Ty,
ArrayRef<Value *> Args) {
Function *F;
if (CGF.Builder.getIsFPConstrained())
F = CGF.CGM.getIntrinsic(ConstrainedIntrinsicID, Ty);
else
F = CGF.CGM.getIntrinsic(IntrinsicID, Ty);
if (CGF.Builder.getIsFPConstrained())
return CGF.Builder.CreateConstrainedFPCall(F, Args);
else
return CGF.Builder.CreateCall(F, Args);
}
// Emit a simple mangled intrinsic that has 1 argument and a return type
// matching the argument type.
static Value *emitUnaryBuiltin(CodeGenFunction &CGF, const CallExpr *E,
unsigned IntrinsicID,
llvm::StringRef Name = "") {
llvm::Value *Src0 = CGF.EmitScalarExpr(E->getArg(0));
Function *F = CGF.CGM.getIntrinsic(IntrinsicID, Src0->getType());
return CGF.Builder.CreateCall(F, Src0, Name);
}
// Emit an intrinsic that has 2 operands of the same type as its result.
static Value *emitBinaryBuiltin(CodeGenFunction &CGF,
const CallExpr *E,
unsigned IntrinsicID) {
llvm::Value *Src0 = CGF.EmitScalarExpr(E->getArg(0));
llvm::Value *Src1 = CGF.EmitScalarExpr(E->getArg(1));
Function *F = CGF.CGM.getIntrinsic(IntrinsicID, Src0->getType());
return CGF.Builder.CreateCall(F, { Src0, Src1 });
}
// Emit an intrinsic that has 3 operands of the same type as its result.
static Value *emitTernaryBuiltin(CodeGenFunction &CGF,
const CallExpr *E,
unsigned IntrinsicID) {
llvm::Value *Src0 = CGF.EmitScalarExpr(E->getArg(0));
llvm::Value *Src1 = CGF.EmitScalarExpr(E->getArg(1));
llvm::Value *Src2 = CGF.EmitScalarExpr(E->getArg(2));
Function *F = CGF.CGM.getIntrinsic(IntrinsicID, Src0->getType());
return CGF.Builder.CreateCall(F, { Src0, Src1, Src2 });
}
// Emit an intrinsic that has 1 float or double operand, and 1 integer.
static Value *emitFPIntBuiltin(CodeGenFunction &CGF,
const CallExpr *E,
unsigned IntrinsicID) {
llvm::Value *Src0 = CGF.EmitScalarExpr(E->getArg(0));
llvm::Value *Src1 = CGF.EmitScalarExpr(E->getArg(1));
Function *F = CGF.CGM.getIntrinsic(IntrinsicID, Src0->getType());
return CGF.Builder.CreateCall(F, {Src0, Src1});
}
// Emit an intrinsic that has overloaded integer result and fp operand.
static Value *
emitMaybeConstrainedFPToIntRoundBuiltin(CodeGenFunction &CGF, const CallExpr *E,
unsigned IntrinsicID,
unsigned ConstrainedIntrinsicID) {
llvm::Type *ResultType = CGF.ConvertType(E->getType());
llvm::Value *Src0 = CGF.EmitScalarExpr(E->getArg(0));
if (CGF.Builder.getIsFPConstrained()) {
CodeGenFunction::CGFPOptionsRAII FPOptsRAII(CGF, E);
Function *F = CGF.CGM.getIntrinsic(ConstrainedIntrinsicID,
{ResultType, Src0->getType()});
return CGF.Builder.CreateConstrainedFPCall(F, {Src0});
} else {
Function *F =
CGF.CGM.getIntrinsic(IntrinsicID, {ResultType, Src0->getType()});
return CGF.Builder.CreateCall(F, Src0);
}
}
static Value *emitFrexpBuiltin(CodeGenFunction &CGF, const CallExpr *E,
llvm::Intrinsic::ID IntrinsicID) {
llvm::Value *Src0 = CGF.EmitScalarExpr(E->getArg(0));
llvm::Value *Src1 = CGF.EmitScalarExpr(E->getArg(1));
QualType IntPtrTy = E->getArg(1)->getType()->getPointeeType();
llvm::Type *IntTy = CGF.ConvertType(IntPtrTy);
llvm::Function *F =
CGF.CGM.getIntrinsic(IntrinsicID, {Src0->getType(), IntTy});
llvm::Value *Call = CGF.Builder.CreateCall(F, Src0);
llvm::Value *Exp = CGF.Builder.CreateExtractValue(Call, 1);
LValue LV = CGF.MakeNaturalAlignAddrLValue(Src1, IntPtrTy);
CGF.EmitStoreOfScalar(Exp, LV);
return CGF.Builder.CreateExtractValue(Call, 0);
}
/// EmitFAbs - Emit a call to @llvm.fabs().
static Value *EmitFAbs(CodeGenFunction &CGF, Value *V) {
Function *F = CGF.CGM.getIntrinsic(Intrinsic::fabs, V->getType());
llvm::CallInst *Call = CGF.Builder.CreateCall(F, V);
Call->setDoesNotAccessMemory();
return Call;
}
/// Emit the computation of the sign bit for a floating point value. Returns
/// the i1 sign bit value.
static Value *EmitSignBit(CodeGenFunction &CGF, Value *V) {
LLVMContext &C = CGF.CGM.getLLVMContext();
llvm::Type *Ty = V->getType();
int Width = Ty->getPrimitiveSizeInBits();
llvm::Type *IntTy = llvm::IntegerType::get(C, Width);
V = CGF.Builder.CreateBitCast(V, IntTy);
if (Ty->isPPC_FP128Ty()) {
// We want the sign bit of the higher-order double. The bitcast we just
// did works as if the double-double was stored to memory and then
// read as an i128. The "store" will put the higher-order double in the
// lower address in both little- and big-Endian modes, but the "load"
// will treat those bits as a different part of the i128: the low bits in
// little-Endian, the high bits in big-Endian. Therefore, on big-Endian
// we need to shift the high bits down to the low before truncating.
Width >>= 1;
if (CGF.getTarget().isBigEndian()) {
Value *ShiftCst = llvm::ConstantInt::get(IntTy, Width);
V = CGF.Builder.CreateLShr(V, ShiftCst);
}
// We are truncating value in order to extract the higher-order
// double, which we will be using to extract the sign from.
IntTy = llvm::IntegerType::get(C, Width);
V = CGF.Builder.CreateTrunc(V, IntTy);
}
Value *Zero = llvm::Constant::getNullValue(IntTy);
return CGF.Builder.CreateICmpSLT(V, Zero);
}
static RValue emitLibraryCall(CodeGenFunction &CGF, const FunctionDecl *FD,
const CallExpr *E, llvm::Constant *calleeValue) {
CGCallee callee = CGCallee::forDirect(calleeValue, GlobalDecl(FD));
return CGF.EmitCall(E->getCallee()->getType(), callee, E, ReturnValueSlot());
}
/// Emit a call to llvm.{sadd,uadd,ssub,usub,smul,umul}.with.overflow.*
/// depending on IntrinsicID.
///
/// \arg CGF The current codegen function.
/// \arg IntrinsicID The ID for the Intrinsic we wish to generate.
/// \arg X The first argument to the llvm.*.with.overflow.*.
/// \arg Y The second argument to the llvm.*.with.overflow.*.
/// \arg Carry The carry returned by the llvm.*.with.overflow.*.
/// \returns The result (i.e. sum/product) returned by the intrinsic.
static llvm::Value *EmitOverflowIntrinsic(CodeGenFunction &CGF,
const llvm::Intrinsic::ID IntrinsicID,
llvm::Value *X, llvm::Value *Y,
llvm::Value *&Carry) {
// Make sure we have integers of the same width.
assert(X->getType() == Y->getType() &&
"Arguments must be the same type. (Did you forget to make sure both "
"arguments have the same integer width?)");
Function *Callee = CGF.CGM.getIntrinsic(IntrinsicID, X->getType());
llvm::Value *Tmp = CGF.Builder.CreateCall(Callee, {X, Y});
Carry = CGF.Builder.CreateExtractValue(Tmp, 1);
return CGF.Builder.CreateExtractValue(Tmp, 0);
}
static Value *emitRangedBuiltin(CodeGenFunction &CGF,
unsigned IntrinsicID,
int low, int high) {
llvm::MDBuilder MDHelper(CGF.getLLVMContext());
llvm::MDNode *RNode = MDHelper.createRange(APInt(32, low), APInt(32, high));
Function *F = CGF.CGM.getIntrinsic(IntrinsicID, {});
llvm::Instruction *Call = CGF.Builder.CreateCall(F);
Call->setMetadata(llvm::LLVMContext::MD_range, RNode);
Call->setMetadata(llvm::LLVMContext::MD_noundef,
llvm::MDNode::get(CGF.getLLVMContext(), std::nullopt));
return Call;
}
namespace {
struct WidthAndSignedness {
unsigned Width;
bool Signed;
};
}
static WidthAndSignedness
getIntegerWidthAndSignedness(const clang::ASTContext &context,
const clang::QualType Type) {
assert(Type->isIntegerType() && "Given type is not an integer.");
unsigned Width = Type->isBooleanType() ? 1
: Type->isBitIntType() ? context.getIntWidth(Type)
: context.getTypeInfo(Type).Width;
bool Signed = Type->isSignedIntegerType();
return {Width, Signed};
}
// Given one or more integer types, this function produces an integer type that
// encompasses them: any value in one of the given types could be expressed in
// the encompassing type.
static struct WidthAndSignedness
EncompassingIntegerType(ArrayRef<struct WidthAndSignedness> Types) {
assert(Types.size() > 0 && "Empty list of types.");
// If any of the given types is signed, we must return a signed type.
bool Signed = false;
for (const auto &Type : Types) {
Signed |= Type.Signed;
}
// The encompassing type must have a width greater than or equal to the width
// of the specified types. Additionally, if the encompassing type is signed,
// its width must be strictly greater than the width of any unsigned types
// given.
unsigned Width = 0;
for (const auto &Type : Types) {
unsigned MinWidth = Type.Width + (Signed && !Type.Signed);
if (Width < MinWidth) {
Width = MinWidth;
}
}
return {Width, Signed};
}
Value *CodeGenFunction::EmitVAStartEnd(Value *ArgValue, bool IsStart) {
Intrinsic::ID inst = IsStart ? Intrinsic::vastart : Intrinsic::vaend;
return Builder.CreateCall(CGM.getIntrinsic(inst, {ArgValue->getType()}),
ArgValue);
}
/// Checks if using the result of __builtin_object_size(p, @p From) in place of
/// __builtin_object_size(p, @p To) is correct
static bool areBOSTypesCompatible(int From, int To) {
// Note: Our __builtin_object_size implementation currently treats Type=0 and
// Type=2 identically. Encoding this implementation detail here may make
// improving __builtin_object_size difficult in the future, so it's omitted.
return From == To || (From == 0 && To == 1) || (From == 3 && To == 2);
}
static llvm::Value *
getDefaultBuiltinObjectSizeResult(unsigned Type, llvm::IntegerType *ResType) {
return ConstantInt::get(ResType, (Type & 2) ? 0 : -1, /*isSigned=*/true);
}
llvm::Value *
CodeGenFunction::evaluateOrEmitBuiltinObjectSize(const Expr *E, unsigned Type,
llvm::IntegerType *ResType,
llvm::Value *EmittedE,
bool IsDynamic) {
uint64_t ObjectSize;
if (!E->tryEvaluateObjectSize(ObjectSize, getContext(), Type))
return emitBuiltinObjectSize(E, Type, ResType, EmittedE, IsDynamic);
return ConstantInt::get(ResType, ObjectSize, /*isSigned=*/true);
}
const FieldDecl *CodeGenFunction::FindFlexibleArrayMemberField(
ASTContext &Ctx, const RecordDecl *RD, StringRef Name, uint64_t &Offset) {
const LangOptions::StrictFlexArraysLevelKind StrictFlexArraysLevel =
getLangOpts().getStrictFlexArraysLevel();
unsigned FieldNo = 0;
bool IsUnion = RD->isUnion();
for (const Decl *D : RD->decls()) {
if (const auto *Field = dyn_cast<FieldDecl>(D);
Field && (Name.empty() || Field->getNameAsString() == Name) &&
Decl::isFlexibleArrayMemberLike(
Ctx, Field, Field->getType(), StrictFlexArraysLevel,
/*IgnoreTemplateOrMacroSubstitution=*/true)) {
const ASTRecordLayout &Layout = Ctx.getASTRecordLayout(RD);
Offset += Layout.getFieldOffset(FieldNo);
return Field;
}
if (const auto *Record = dyn_cast<RecordDecl>(D))
if (const FieldDecl *Field =
FindFlexibleArrayMemberField(Ctx, Record, Name, Offset)) {
const ASTRecordLayout &Layout = Ctx.getASTRecordLayout(RD);
Offset += Layout.getFieldOffset(FieldNo);
return Field;
}
if (!IsUnion && isa<FieldDecl>(D))
++FieldNo;
}
return nullptr;
}
static unsigned CountCountedByAttrs(const RecordDecl *RD) {
unsigned Num = 0;
for (const Decl *D : RD->decls()) {
if (const auto *FD = dyn_cast<FieldDecl>(D);
FD && FD->getType()->isCountAttributedType()) {
return ++Num;
}
if (const auto *Rec = dyn_cast<RecordDecl>(D))
Num += CountCountedByAttrs(Rec);
}
return Num;
}
llvm::Value *
CodeGenFunction::emitFlexibleArrayMemberSize(const Expr *E, unsigned Type,
llvm::IntegerType *ResType) {
// The code generated here calculates the size of a struct with a flexible
// array member that uses the counted_by attribute. There are two instances
// we handle:
//
// struct s {
// unsigned long flags;
// int count;
// int array[] __attribute__((counted_by(count)));
// }
//
// 1) bdos of the flexible array itself:
//
// __builtin_dynamic_object_size(p->array, 1) ==
// p->count * sizeof(*p->array)
//
// 2) bdos of a pointer into the flexible array:
//
// __builtin_dynamic_object_size(&p->array[42], 1) ==
// (p->count - 42) * sizeof(*p->array)
//
// 2) bdos of the whole struct, including the flexible array:
//
// __builtin_dynamic_object_size(p, 1) ==
// max(sizeof(struct s),
// offsetof(struct s, array) + p->count * sizeof(*p->array))
//
ASTContext &Ctx = getContext();
const Expr *Base = E->IgnoreParenImpCasts();
const Expr *Idx = nullptr;
if (const auto *UO = dyn_cast<UnaryOperator>(Base);
UO && UO->getOpcode() == UO_AddrOf) {
Expr *SubExpr = UO->getSubExpr()->IgnoreParenImpCasts();
if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(SubExpr)) {
Base = ASE->getBase()->IgnoreParenImpCasts();
Idx = ASE->getIdx()->IgnoreParenImpCasts();
if (const auto *IL = dyn_cast<IntegerLiteral>(Idx)) {
int64_t Val = IL->getValue().getSExtValue();
if (Val < 0)
return getDefaultBuiltinObjectSizeResult(Type, ResType);
if (Val == 0)
// The index is 0, so we don't need to take it into account.
Idx = nullptr;
}
} else {
// Potential pointer to another element in the struct.
Base = SubExpr;
}
}
// Get the flexible array member Decl.
const RecordDecl *OuterRD = nullptr;
std::string FAMName;
if (const auto *ME = dyn_cast<MemberExpr>(Base)) {
// Check if \p Base is referencing the FAM itself.
const ValueDecl *VD = ME->getMemberDecl();
OuterRD = VD->getDeclContext()->getOuterLexicalRecordContext();
FAMName = VD->getNameAsString();
} else if (const auto *DRE = dyn_cast<DeclRefExpr>(Base)) {
// Check if we're pointing to the whole struct.
QualType Ty = DRE->getDecl()->getType();
if (Ty->isPointerType())
Ty = Ty->getPointeeType();
OuterRD = Ty->getAsRecordDecl();
// If we have a situation like this:
//
// struct union_of_fams {
// int flags;
// union {
// signed char normal_field;
// struct {
// int count1;
// int arr1[] __counted_by(count1);
// };
// struct {
// signed char count2;
// int arr2[] __counted_by(count2);
// };
// };
// };
//
// We don't know which 'count' to use in this scenario:
//
// size_t get_size(struct union_of_fams *p) {
// return __builtin_dynamic_object_size(p, 1);
// }
//
// Instead of calculating a wrong number, we give up.
if (OuterRD && CountCountedByAttrs(OuterRD) > 1)
return nullptr;
}
if (!OuterRD)
return nullptr;
uint64_t Offset = 0;
const FieldDecl *FAMDecl =
FindFlexibleArrayMemberField(Ctx, OuterRD, FAMName, Offset);
Offset = Ctx.toCharUnitsFromBits(Offset).getQuantity();
if (!FAMDecl || !FAMDecl->getType()->isCountAttributedType())
// No flexible array member found or it doesn't have the "counted_by"
// attribute.
return nullptr;
const FieldDecl *CountedByFD = FindCountedByField(FAMDecl);
if (!CountedByFD)
// Can't find the field referenced by the "counted_by" attribute.
return nullptr;
// Build a load of the counted_by field.
bool IsSigned = CountedByFD->getType()->isSignedIntegerType();
Value *CountedByInst = EmitCountedByFieldExpr(Base, FAMDecl, CountedByFD);
if (!CountedByInst)
return getDefaultBuiltinObjectSizeResult(Type, ResType);
CountedByInst = Builder.CreateIntCast(CountedByInst, ResType, IsSigned);
// Build a load of the index and subtract it from the count.
Value *IdxInst = nullptr;
if (Idx) {
if (Idx->HasSideEffects(getContext()))