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The MicroBlaze is a highly configurable 32-bit soft-microprocessor for use on Xilinx FPGAs. For more information see: http://www.xilinx.com/tools/microblaze.htm http://en.wikipedia.org/wiki/MicroBlaze The current LLVM MicroBlaze backend generates assembly which can be compiled using the an appropriate binutils assembler. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96969 91177308-0d34-0410-b5e6-96231b3b80d8
89 lines
3.0 KiB
C++
89 lines
3.0 KiB
C++
//===-- MBlazeTargetObjectFile.cpp - MBlaze object files ------------------===//
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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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#include "MBlazeTargetObjectFile.h"
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#include "MBlazeSubtarget.h"
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#include "llvm/DerivedTypes.h"
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#include "llvm/GlobalVariable.h"
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#include "llvm/MC/MCSectionELF.h"
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#include "llvm/Target/TargetData.h"
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#include "llvm/Target/TargetMachine.h"
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#include "llvm/Support/CommandLine.h"
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using namespace llvm;
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void MBlazeTargetObjectFile::
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Initialize(MCContext &Ctx, const TargetMachine &TM) {
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TargetLoweringObjectFileELF::Initialize(Ctx, TM);
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SmallDataSection =
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getELFSection(".sdata", MCSectionELF::SHT_PROGBITS,
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MCSectionELF::SHF_WRITE | MCSectionELF::SHF_ALLOC,
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SectionKind::getDataRel());
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SmallBSSSection =
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getELFSection(".sbss", MCSectionELF::SHT_NOBITS,
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MCSectionELF::SHF_WRITE | MCSectionELF::SHF_ALLOC,
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SectionKind::getBSS());
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}
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// A address must be loaded from a small section if its size is less than the
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// small section size threshold. Data in this section must be addressed using
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// gp_rel operator.
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static bool IsInSmallSection(uint64_t Size) {
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return Size > 0 && Size <= 8;
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}
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bool MBlazeTargetObjectFile::
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IsGlobalInSmallSection(const GlobalValue *GV, const TargetMachine &TM) const {
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if (GV->isDeclaration() || GV->hasAvailableExternallyLinkage())
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return false;
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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 address should be
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/// placed into small data/bss section.
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bool MBlazeTargetObjectFile::
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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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// We can only do this for datarel or BSS objects for now.
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if (!Kind.isBSS() && !Kind.isDataRel())
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return false;
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// If this is a internal constant string, there is a special
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// section for it, but not in small data/bss.
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if (Kind.isMergeable1ByteCString())
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return false;
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const Type *Ty = GV->getType()->getElementType();
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return IsInSmallSection(TM.getTargetData()->getTypeAllocSize(Ty));
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}
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const MCSection *MBlazeTargetObjectFile::
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SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
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Mangler *Mang, const TargetMachine &TM) const {
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// TODO: Could also support "weak" symbols as well with ".gnu.linkonce.s.*"
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// sections?
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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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