Mercurial > hg > CbC > CbC_llvm
diff lib/Target/Hexagon/HexagonTargetObjectFile.cpp @ 0:95c75e76d11b LLVM3.4
LLVM 3.4
author | Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> |
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date | Thu, 12 Dec 2013 13:56:28 +0900 |
parents | |
children | 54457678186b |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/lib/Target/Hexagon/HexagonTargetObjectFile.cpp Thu Dec 12 13:56:28 2013 +0900 @@ -0,0 +1,100 @@ +//===-- 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); +}