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//===-- TargetMachine.cpp - General Target Information ---------------------==//
// The LLVM Compiler Infrastructure
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
// This file describes the general parts of a Target machine.
#include "llvm/Target/TargetMachine.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalAlias.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Mangler.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCCodeGenInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCSectionMachO.h"
#include "llvm/MC/MCTargetOptions.h"
#include "llvm/MC/SectionKind.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetLoweringObjectFile.h"
#include "llvm/Target/TargetSubtargetInfo.h"
using namespace llvm;
// TargetMachine Class
TargetMachine::TargetMachine(const Target &T,
StringRef TT, StringRef CPU, StringRef FS,
const TargetOptions &Options)
: TheTarget(T), TargetTriple(TT), TargetCPU(CPU), TargetFS(FS),
CodeGenInfo(nullptr), AsmInfo(nullptr),
Options(Options) {
TargetMachine::~TargetMachine() {
delete CodeGenInfo;
delete AsmInfo;
/// \brief Reset the target options based on the function's attributes.
void TargetMachine::resetTargetOptions(const Function &F) const {
#define RESET_OPTION(X, Y) \
do { \
if (F.hasFnAttribute(Y)) \
Options.X = (F.getAttributes() \
.getAttribute(AttributeSet::FunctionIndex, Y) \
.getValueAsString() == "true"); \
} while (0)
RESET_OPTION(NoFramePointerElim, "no-frame-pointer-elim");
RESET_OPTION(LessPreciseFPMADOption, "less-precise-fpmad");
RESET_OPTION(UnsafeFPMath, "unsafe-fp-math");
RESET_OPTION(NoInfsFPMath, "no-infs-fp-math");
RESET_OPTION(NoNaNsFPMath, "no-nans-fp-math");
RESET_OPTION(UseSoftFloat, "use-soft-float");
RESET_OPTION(DisableTailCalls, "disable-tail-calls");
Options.MCOptions.SanitizeAddress = F.hasFnAttribute(Attribute::SanitizeAddress);
/// getRelocationModel - Returns the code generation relocation model. The
/// choices are static, PIC, and dynamic-no-pic, and target default.
Reloc::Model TargetMachine::getRelocationModel() const {
if (!CodeGenInfo)
return Reloc::Default;
return CodeGenInfo->getRelocationModel();
/// getCodeModel - Returns the code model. The choices are small, kernel,
/// medium, large, and target default.
CodeModel::Model TargetMachine::getCodeModel() const {
if (!CodeGenInfo)
return CodeModel::Default;
return CodeGenInfo->getCodeModel();
/// Get the IR-specified TLS model for Var.
static TLSModel::Model getSelectedTLSModel(const GlobalValue *GV) {
switch (GV->getThreadLocalMode()) {
case GlobalVariable::NotThreadLocal:
llvm_unreachable("getSelectedTLSModel for non-TLS variable");
case GlobalVariable::GeneralDynamicTLSModel:
return TLSModel::GeneralDynamic;
case GlobalVariable::LocalDynamicTLSModel:
return TLSModel::LocalDynamic;
case GlobalVariable::InitialExecTLSModel:
return TLSModel::InitialExec;
case GlobalVariable::LocalExecTLSModel:
return TLSModel::LocalExec;
llvm_unreachable("invalid TLS model");
TLSModel::Model TargetMachine::getTLSModel(const GlobalValue *GV) const {
bool isLocal = GV->hasLocalLinkage();
bool isDeclaration = GV->isDeclaration();
bool isPIC = getRelocationModel() == Reloc::PIC_;
bool isPIE = Options.PositionIndependentExecutable;
// FIXME: what should we do for protected and internal visibility?
// For variables, is internal different from hidden?
bool isHidden = GV->hasHiddenVisibility();
TLSModel::Model Model;
if (isPIC && !isPIE) {
if (isLocal || isHidden)
Model = TLSModel::LocalDynamic;
Model = TLSModel::GeneralDynamic;
} else {
if (!isDeclaration || isHidden)
Model = TLSModel::LocalExec;
Model = TLSModel::InitialExec;
// If the user specified a more specific model, use that.
TLSModel::Model SelectedModel = getSelectedTLSModel(GV);
if (SelectedModel > Model)
return SelectedModel;
return Model;
/// getOptLevel - Returns the optimization level: None, Less,
/// Default, or Aggressive.
CodeGenOpt::Level TargetMachine::getOptLevel() const {
if (!CodeGenInfo)
return CodeGenOpt::Default;
return CodeGenInfo->getOptLevel();
void TargetMachine::setOptLevel(CodeGenOpt::Level Level) const {
if (CodeGenInfo)
bool TargetMachine::getAsmVerbosityDefault() const {
return Options.MCOptions.AsmVerbose;
void TargetMachine::setAsmVerbosityDefault(bool V) {
Options.MCOptions.AsmVerbose = V;
bool TargetMachine::getFunctionSections() const {
return Options.FunctionSections;
bool TargetMachine::getDataSections() const {
return Options.DataSections;
void TargetMachine::setFunctionSections(bool V) {
Options.FunctionSections = V;
void TargetMachine::setDataSections(bool V) {
Options.DataSections = V;
static bool canUsePrivateLabel(const MCAsmInfo &AsmInfo,
const MCSection &Section) {
if (!AsmInfo.isSectionAtomizableBySymbols(Section))
return true;
// If it is not dead stripped, it is safe to use private labels.
const MCSectionMachO &SMO = cast<MCSectionMachO>(Section);
if (SMO.hasAttribute(MachO::S_ATTR_NO_DEAD_STRIP))
return true;
return false;
void TargetMachine::getNameWithPrefix(SmallVectorImpl<char> &Name,
const GlobalValue *GV, Mangler &Mang,
bool MayAlwaysUsePrivate) const {
if (MayAlwaysUsePrivate || !GV->hasPrivateLinkage()) {
// Simple case: If GV is not private, it is not important to find out if
// private labels are legal in this case or not.
Mang.getNameWithPrefix(Name, GV, false);
SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, *this);
const TargetLoweringObjectFile &TLOF =
const MCSection *TheSection = TLOF.SectionForGlobal(GV, GVKind, Mang, *this);
bool CannotUsePrivateLabel = !canUsePrivateLabel(*AsmInfo, *TheSection);
Mang.getNameWithPrefix(Name, GV, CannotUsePrivateLabel);
MCSymbol *TargetMachine::getSymbol(const GlobalValue *GV, Mangler &Mang) const {
SmallString<60> NameStr;
getNameWithPrefix(NameStr, GV, Mang);
const TargetLoweringObjectFile &TLOF =
return TLOF.getContext().GetOrCreateSymbol(NameStr.str());