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//===-- HexagonTargetObjectFile.cpp - Hexagon asm properties --------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the declarations of the HexagonTargetAsmInfo properties.
//
//===----------------------------------------------------------------------===//
#include "HexagonTargetObjectFile.h"
#include "HexagonSubtarget.h"
#include "HexagonTargetMachine.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/MC/MCContext.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ELF.h"
using namespace llvm;
static cl::opt<int> SmallDataThreshold("hexagon-small-data-threshold",
cl::init(8), cl::Hidden,
cl::desc("The maximum size of an object in the sdata section"));
void HexagonTargetObjectFile::Initialize(MCContext &Ctx,
const TargetMachine &TM) {
TargetLoweringObjectFileELF::Initialize(Ctx, TM);
SmallDataSection =
getContext().getELFSection(".sdata", ELF::SHT_PROGBITS,
ELF::SHF_WRITE | ELF::SHF_ALLOC,
SectionKind::getDataRel());
SmallBSSSection =
getContext().getELFSection(".sbss", ELF::SHT_NOBITS,
ELF::SHF_WRITE | ELF::SHF_ALLOC,
SectionKind::getBSS());
}
// sdata/sbss support taken largely from the MIPS Backend.
static bool IsInSmallSection(uint64_t Size) {
return Size > 0 && Size <= (uint64_t)SmallDataThreshold;
}
bool HexagonTargetObjectFile::IsSmallDataEnabled () const {
return SmallDataThreshold > 0;
}
/// IsGlobalInSmallSection - Return true if this global value should be
/// placed into small data/bss section.
bool HexagonTargetObjectFile::IsGlobalInSmallSection(const GlobalValue *GV,
const TargetMachine &TM) const {
// If the primary definition of this global value is outside the current
// translation unit or the global value is available for inspection but not
// emission, then do nothing.
if (GV->isDeclaration() || GV->hasAvailableExternallyLinkage())
return false;
// Otherwise, Check if GV should be in sdata/sbss, when normally it would end
// up in getKindForGlobal(GV, TM).
return IsGlobalInSmallSection(GV, TM, getKindForGlobal(GV, TM));
}
/// IsGlobalInSmallSection - Return true if this global value should be
/// placed into small data/bss section.
bool HexagonTargetObjectFile::
IsGlobalInSmallSection(const GlobalValue *GV, const TargetMachine &TM,
SectionKind Kind) const {
// Only global variables, not functions.
const GlobalVariable *GVA = dyn_cast<GlobalVariable>(GV);
if (!GVA)
return false;
if (Kind.isBSS() || Kind.isDataNoRel() || Kind.isCommon()) {
Type *Ty = GV->getType()->getElementType();
return IsInSmallSection(TM.getDataLayout()->getTypeAllocSize(Ty));
}
return false;
}
const MCSection *
HexagonTargetObjectFile::SelectSectionForGlobal(const GlobalValue *GV,
SectionKind Kind, Mangler &Mang,
const TargetMachine &TM) const {
// Handle Small Section classification here.
if (Kind.isBSS() && IsGlobalInSmallSection(GV, TM, Kind))
return SmallBSSSection;
if (Kind.isDataNoRel() && IsGlobalInSmallSection(GV, TM, Kind))
return SmallDataSection;
// Otherwise, we work the same as ELF.
return TargetLoweringObjectFileELF::SelectSectionForGlobal(GV, Kind, Mang,TM);
}
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