LLVM  16.0.0git
AVRTargetObjectFile.cpp
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1 //===-- AVRTargetObjectFile.cpp - AVR Object Files ------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "AVRTargetObjectFile.h"
10 #include "AVRTargetMachine.h"
11 
12 #include "llvm/BinaryFormat/ELF.h"
13 #include "llvm/IR/DerivedTypes.h"
14 #include "llvm/IR/GlobalValue.h"
15 #include "llvm/IR/Mangler.h"
16 #include "llvm/MC/MCContext.h"
17 #include "llvm/MC/MCSectionELF.h"
18 
19 #include "AVR.h"
20 
21 namespace llvm {
23  Base::Initialize(Ctx, TM);
24  ProgmemDataSection =
25  Ctx.getELFSection(".progmem.data", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
26  Progmem1DataSection =
27  Ctx.getELFSection(".progmem1.data", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
28  Progmem2DataSection =
29  Ctx.getELFSection(".progmem2.data", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
30  Progmem3DataSection =
31  Ctx.getELFSection(".progmem3.data", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
32  Progmem4DataSection =
33  Ctx.getELFSection(".progmem4.data", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
34  Progmem5DataSection =
35  Ctx.getELFSection(".progmem5.data", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
36 }
37 
39  const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
40  // Global values in flash memory are placed in the progmem*.data section
41  // unless they already have a user assigned section.
42  const auto &AVRTM = static_cast<const AVRTargetMachine &>(TM);
43  if (AVR::isProgramMemoryAddress(GO) && !GO->hasSection() &&
44  Kind.isReadOnly()) {
45  // The AVR subtarget should support LPM to access section '.progmem*.data'.
46  if (!AVRTM.getSubtargetImpl()->hasLPM()) {
47  // TODO: Get the global object's location in source file.
49  SMLoc(),
50  "Current AVR subtarget does not support accessing program memory");
51  return Base::SelectSectionForGlobal(GO, Kind, TM);
52  }
53  // The AVR subtarget should support ELPM to access section
54  // '.progmem[1|2|3|4|5].data'.
55  if (!AVRTM.getSubtargetImpl()->hasELPM() &&
57  // TODO: Get the global object's location in source file.
59  "Current AVR subtarget does not support "
60  "accessing extended program memory");
61  return ProgmemDataSection;
62  }
63  switch (AVR::getAddressSpace(GO)) {
64  case AVR::ProgramMemory: // address space 1
65  return ProgmemDataSection;
66  case AVR::ProgramMemory1: // address space 2
67  return Progmem1DataSection;
68  case AVR::ProgramMemory2: // address space 3
69  return Progmem2DataSection;
70  case AVR::ProgramMemory3: // address space 4
71  return Progmem3DataSection;
72  case AVR::ProgramMemory4: // address space 5
73  return Progmem4DataSection;
74  case AVR::ProgramMemory5: // address space 6
75  return Progmem5DataSection;
76  default:
77  llvm_unreachable("unexpected program memory index");
78  }
79  }
80 
81  // Otherwise, we work the same way as ELF.
82  return Base::SelectSectionForGlobal(GO, Kind, TM);
83 }
84 } // end of namespace llvm
llvm
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
llvm::TargetLoweringObjectFileELF::SelectSectionForGlobal
MCSection * SelectSectionForGlobal(const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const override
Definition: TargetLoweringObjectFileImpl.cpp:922
llvm::MCContext
Context object for machine code objects.
Definition: MCContext.h:76
llvm::AVRTargetMachine
A generic AVR implementation.
Definition: AVRTargetMachine.h:28
MCSectionELF.h
llvm::AVR::ProgramMemory
@ ProgramMemory
Definition: AVR.h:43
llvm::AVR::ProgramMemory2
@ ProgramMemory2
Definition: AVR.h:45
llvm::ELF::SHT_PROGBITS
@ SHT_PROGBITS
Definition: ELF.h:980
llvm::AVR::ProgramMemory3
@ ProgramMemory3
Definition: AVR.h:46
llvm::MCObjectFileInfo::getContext
MCContext & getContext() const
Definition: MCObjectFileInfo.h:244
llvm::AVR::getAddressSpace
AddressSpace getAddressSpace(T *V)
Definition: AVR.h:64
llvm::AVR::ProgramMemory1
@ ProgramMemory1
Definition: AVR.h:44
GlobalValue.h
ELF.h
llvm::SMLoc
Represents a location in source code.
Definition: SMLoc.h:23
llvm::AVR::ProgramMemory5
@ ProgramMemory5
Definition: AVR.h:48
llvm::AVRTargetObjectFile::Initialize
void Initialize(MCContext &ctx, const TargetMachine &TM) override
This method must be called before any actual lowering is done.
Definition: AVRTargetObjectFile.cpp:22
llvm::GlobalObject
Definition: GlobalObject.h:27
MCContext.h
llvm::MCContext::getELFSection
MCSectionELF * getELFSection(const Twine &Section, unsigned Type, unsigned Flags)
Definition: MCContext.h:564
llvm::AVRTargetObjectFile::SelectSectionForGlobal
MCSection * SelectSectionForGlobal(const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const override
Definition: AVRTargetObjectFile.cpp:38
llvm::TargetLoweringObjectFile::TM
const TargetMachine * TM
Definition: TargetLoweringObjectFile.h:68
llvm::AVR::ProgramMemory4
@ ProgramMemory4
Definition: AVR.h:47
llvm::GlobalObject::hasSection
bool hasSection() const
Check if this global has a custom object file section.
Definition: GlobalObject.h:103
llvm::ELF::SHF_ALLOC
@ SHF_ALLOC
Definition: ELF.h:1068
AVRTargetMachine.h
llvm::TargetMachine
Primary interface to the complete machine description for the target machine.
Definition: TargetMachine.h:76
llvm::AVR::isProgramMemoryAddress
bool isProgramMemoryAddress(T *V)
Checks if a given type is a pointer to program memory.
Definition: AVR.h:53
llvm::MCContext::reportError
void reportError(SMLoc L, const Twine &Msg)
Definition: MCContext.cpp:1056
Mangler.h
llvm_unreachable
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
Definition: ErrorHandling.h:143
llvm::MCSection
Instances of this class represent a uniqued identifier for a section in the current translation unit.
Definition: MCSection.h:39
AVRTargetObjectFile.h
llvm::SectionKind
SectionKind - This is a simple POD value that classifies the properties of a section.
Definition: SectionKind.h:22
llvm::TargetLoweringObjectFileELF::Initialize
void Initialize(MCContext &Ctx, const TargetMachine &TM) override
This method must be called before any actual lowering is done.
Definition: TargetLoweringObjectFileImpl.cpp:116
AVR.h
DerivedTypes.h
TM
const char LLVMTargetMachineRef TM
Definition: PassBuilderBindings.cpp:47