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https://github.com/c64scene-ar/llvm-6502.git
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7521964d28
This starts merging MCSection and MCSectionData. There are a few issues with the current split between MCSection and MCSectionData. * It optimizes the the not as important case. We want the production of .o files to be really fast, but the split puts the information used for .o emission in a separate data structure. * The ELF/COFF/MachO hierarchy is not represented in MCSectionData, leading to some ad-hoc ways to represent the various flags. * It makes it harder to remember where each item is. The attached patch starts merging the two by moving the alignment from MCSectionData to MCSection. Most of the patch is actually just dropping 'const', since MCSectionData is mutable, but MCSection was not. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237936 91177308-0d34-0410-b5e6-96231b3b80d8
98 lines
3.7 KiB
C++
98 lines
3.7 KiB
C++
//===-- HexagonTargetObjectFile.cpp - Hexagon asm properties --------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file contains the declarations of the HexagonTargetAsmInfo properties.
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//
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//===----------------------------------------------------------------------===//
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#include "HexagonTargetObjectFile.h"
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#include "HexagonSubtarget.h"
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#include "HexagonTargetMachine.h"
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#include "llvm/IR/DataLayout.h"
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#include "llvm/IR/DerivedTypes.h"
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#include "llvm/IR/Function.h"
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#include "llvm/IR/GlobalVariable.h"
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#include "llvm/MC/MCContext.h"
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#include "llvm/Support/CommandLine.h"
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#include "llvm/Support/ELF.h"
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using namespace llvm;
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static cl::opt<int> SmallDataThreshold("hexagon-small-data-threshold",
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cl::init(8), cl::Hidden,
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cl::desc("The maximum size of an object in the sdata section"));
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void HexagonTargetObjectFile::Initialize(MCContext &Ctx,
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const TargetMachine &TM) {
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TargetLoweringObjectFileELF::Initialize(Ctx, TM);
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InitializeELF(TM.Options.UseInitArray);
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SmallDataSection = getContext().getELFSection(
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".sdata", ELF::SHT_PROGBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC);
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SmallBSSSection = getContext().getELFSection(".sbss", ELF::SHT_NOBITS,
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ELF::SHF_WRITE | ELF::SHF_ALLOC);
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}
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// sdata/sbss support taken largely from the MIPS Backend.
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static bool IsInSmallSection(uint64_t Size) {
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return Size > 0 && Size <= (uint64_t)SmallDataThreshold;
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}
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bool HexagonTargetObjectFile::IsSmallDataEnabled () const {
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return SmallDataThreshold > 0;
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}
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/// IsGlobalInSmallSection - Return true if this global value should be
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/// placed into small data/bss section.
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bool HexagonTargetObjectFile::IsGlobalInSmallSection(const GlobalValue *GV,
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const TargetMachine &TM) const {
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// If the primary definition of this global value is outside the current
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// translation unit or the global value is available for inspection but not
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// emission, then do nothing.
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if (GV->isDeclaration() || GV->hasAvailableExternallyLinkage())
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return false;
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// Otherwise, Check if GV should be in sdata/sbss, when normally it would end
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// up in getKindForGlobal(GV, TM).
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return IsGlobalInSmallSection(GV, TM, getKindForGlobal(GV, TM));
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}
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/// IsGlobalInSmallSection - Return true if this global value should be
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/// placed into small data/bss section.
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bool HexagonTargetObjectFile::
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IsGlobalInSmallSection(const GlobalValue *GV, const TargetMachine &TM,
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SectionKind Kind) const {
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// Only global variables, not functions.
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const GlobalVariable *GVA = dyn_cast<GlobalVariable>(GV);
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if (!GVA)
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return false;
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if (Kind.isBSS() || Kind.isDataNoRel() || Kind.isCommon()) {
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Type *Ty = GV->getType()->getElementType();
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return IsInSmallSection(TM.getDataLayout()->getTypeAllocSize(Ty));
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}
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return false;
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}
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MCSection *
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HexagonTargetObjectFile::SelectSectionForGlobal(const GlobalValue *GV,
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SectionKind Kind, Mangler &Mang,
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const TargetMachine &TM) const {
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// Handle Small Section classification here.
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if (Kind.isBSS() && IsGlobalInSmallSection(GV, TM, Kind))
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return SmallBSSSection;
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if (Kind.isDataNoRel() && IsGlobalInSmallSection(GV, TM, Kind))
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return SmallDataSection;
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// Otherwise, we work the same as ELF.
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return TargetLoweringObjectFileELF::SelectSectionForGlobal(GV, Kind, Mang,TM);
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}
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