llvm-6502/lib/Target/Hexagon/HexagonTargetObjectFile.cpp
Rafael Espindola 9936b80df5 Compute the ELF SectionKind from the flags.
Any code creating an MCSectionELF knows ELF and already provides the flags.

SectionKind is an abstraction used by common code that uses a plain
MCSection.

Use the flags to compute the SectionKind. This removes a lot of
guessing and boilerplate from the MCSectionELF construction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227476 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-29 17:33:21 +00:00

98 lines
3.7 KiB
C++

//===-- 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);
InitializeELF(TM.Options.UseInitArray);
SmallDataSection = getContext().getELFSection(
".sdata", ELF::SHT_PROGBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC);
SmallBSSSection = getContext().getELFSection(".sbss", ELF::SHT_NOBITS,
ELF::SHF_WRITE | ELF::SHF_ALLOC);
}
// 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);
}