[lld] r257023 - [ELF] Add AMDGPU support
Tom Stellard via llvm-commits
llvm-commits at lists.llvm.org
Thu Jan 7 09:09:50 PST 2016
On Wed, Jan 06, 2016 at 09:40:03PM -0800, Rui Ueyama via llvm-commits wrote:
> Is this actually all you have to do to use the new ELF linker instead of
> the old one for AMDGPU? I'm asking because this is a rather small patch.
> Are you planning to do something in addition to this?
>
Hi,
This is all that is required to use the new linker for our current set of
tests cases (C++AMP conformance tests). It's possible in the future we
may need to add relocation support to the executable file format, but I'm not
sure about this.
We are also considering a shared object format for AMDGPU, which would support
additional features and potentially require some more changes to the linker,
however, I don't have a lot of details on this yet.
-Tom
> On Wed, Jan 6, 2016 at 7:59 PM, Tom Stellard via llvm-commits <
> llvm-commits at lists.llvm.org> wrote:
>
> > Author: tstellar
> > Date: Wed Jan 6 21:59:08 2016
> > New Revision: 257023
> >
> > URL: http://llvm.org/viewvc/llvm-project?rev=257023&view=rev
> > Log:
> > [ELF] Add AMDGPU support
> >
> > Summary: This will allow us to remove the AMDGPU support from old ELF.
> >
> > Reviewers: rafael, ruiu
> >
> > Differential Revision: http://reviews.llvm.org/D15895
> >
> > Added:
> > lld/trunk/test/ELF/amdgpu-entry.s
> > lld/trunk/test/ELF/amdgpu-globals.s
> > lld/trunk/test/ELF/amdgpu-kernels.s
> > Modified:
> > lld/trunk/ELF/Driver.cpp
> > lld/trunk/ELF/OutputSections.cpp
> > lld/trunk/ELF/Target.cpp
> > lld/trunk/ELF/Writer.cpp
> >
> > Modified: lld/trunk/ELF/Driver.cpp
> > URL:
> > http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Driver.cpp?rev=257023&r1=257022&r2=257023&view=diff
> >
> > ==============================================================================
> > --- lld/trunk/ELF/Driver.cpp (original)
> > +++ lld/trunk/ELF/Driver.cpp Wed Jan 6 21:59:08 2016
> > @@ -253,6 +253,9 @@ void LinkerDriver::createFiles(opt::Inpu
> >
> > if (Config->GnuHash && Config->EMachine == EM_MIPS)
> > error("The .gnu.hash section is not compatible with the MIPS
> > target.");
> > +
> > + if (!Config->Entry.empty() && Config->EMachine == EM_AMDGPU)
> > + error("-e option is not valid for AMDGPU.");
> > }
> >
> > template <class ELFT> void LinkerDriver::link(opt::InputArgList &Args) {
> > @@ -261,7 +264,10 @@ template <class ELFT> void LinkerDriver:
> >
> > if (!Config->Shared) {
> > // Add entry symbol.
> > - if (Config->Entry.empty())
> > + //
> > + // There is no entry symbol for AMDGPU binaries, so skip adding one
> > to avoid
> > + // having and undefined symbol.
> > + if (Config->Entry.empty() && Config->EMachine != EM_AMDGPU)
> > Config->Entry = (Config->EMachine == EM_MIPS) ? "__start" :
> > "_start";
> >
> > // In the assembly for 32 bit x86 the _GLOBAL_OFFSET_TABLE_ symbol
> >
> > Modified: lld/trunk/ELF/OutputSections.cpp
> > URL:
> > http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/OutputSections.cpp?rev=257023&r1=257022&r2=257023&view=diff
> >
> > ==============================================================================
> > --- lld/trunk/ELF/OutputSections.cpp (original)
> > +++ lld/trunk/ELF/OutputSections.cpp Wed Jan 6 21:59:08 2016
> > @@ -788,6 +788,11 @@ typename ELFFile<ELFT>::uintX_t elf2::ge
> > InputSectionBase<ELFT> *SC = DR.Section;
> > if (!SC)
> > return DR.Sym.st_value;
> > +
> > + // Symbol offsets for AMDGPU need to be the offset in bytes of the
> > symbol
> > + // from the beginning of the section.
> > + if (Config->EMachine == EM_AMDGPU)
> > + return SC->getOffset(DR.Sym);
> > if (DR.Sym.getType() == STT_TLS)
> > return SC->OutSec->getVA() + SC->getOffset(DR.Sym) -
> > Out<ELFT>::TlsPhdr->p_vaddr;
> > @@ -1325,7 +1330,11 @@ void SymbolTableSection<ELFT>::writeLoca
> > continue;
> > const OutputSectionBase<ELFT> *OutSec = Section->OutSec;
> > ESym->st_shndx = OutSec->SectionIndex;
> > - VA += OutSec->getVA() + Section->getOffset(Sym);
> > + VA = Section->getOffset(Sym);
> > + // Symbol offsets for AMDGPU need to be the offset in bytes of the
> > + // symbol from the beginning of the section.
> > + if (Config->EMachine != EM_AMDGPU)
> > + VA += OutSec->getVA();
> > }
> > ESym->st_name = StrTabSec.addString(SymName);
> > ESym->st_size = Sym.st_size;
> >
> > Modified: lld/trunk/ELF/Target.cpp
> > URL:
> > http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Target.cpp?rev=257023&r1=257022&r2=257023&view=diff
> >
> > ==============================================================================
> > --- lld/trunk/ELF/Target.cpp (original)
> > +++ lld/trunk/ELF/Target.cpp Wed Jan 6 21:59:08 2016
> > @@ -191,6 +191,22 @@ public:
> > uint8_t *PairedLoc = nullptr) const override;
> > };
> >
> > +class AMDGPUTargetInfo final : public TargetInfo {
> > +public:
> > + AMDGPUTargetInfo();
> > + void writeGotPltEntry(uint8_t *Buf, uint64_t Plt) const override;
> > + void writePltZeroEntry(uint8_t *Buf, uint64_t GotEntryAddr,
> > + uint64_t PltEntryAddr) const override;
> > + void writePltEntry(uint8_t *Buf, uint64_t GotAddr, uint64_t
> > GotEntryAddr,
> > + uint64_t PltEntryAddr, int32_t Index,
> > + unsigned RelOff) const override;
> > + bool relocNeedsGot(uint32_t Type, const SymbolBody &S) const override;
> > + bool relocNeedsPlt(uint32_t Type, const SymbolBody &S) const override;
> > + void relocateOne(uint8_t *Loc, uint8_t *BufEnd, uint32_t Type, uint64_t
> > P,
> > + uint64_t SA, uint64_t ZA = 0,
> > + uint8_t *PairedLoc = nullptr) const override;
> > +};
> > +
> > template <class ELFT> class MipsTargetInfo final : public TargetInfo {
> > public:
> > MipsTargetInfo();
> > @@ -216,6 +232,8 @@ TargetInfo *createTarget() {
> > return new X86TargetInfo();
> > case EM_AARCH64:
> > return new AArch64TargetInfo();
> > + case EM_AMDGPU:
> > + return new AMDGPUTargetInfo();
> > case EM_MIPS:
> > switch (Config->EKind) {
> > case ELF32LEKind:
> > @@ -1315,6 +1333,38 @@ void AArch64TargetInfo::relocateOne(uint
> > }
> > }
> >
> > +AMDGPUTargetInfo::AMDGPUTargetInfo() {}
> > +
> > +void AMDGPUTargetInfo::writeGotPltEntry(uint8_t *Buf, uint64_t Plt) const
> > {
> > + llvm_unreachable("not implemented");
> > +}
> > +
> > +void AMDGPUTargetInfo::writePltZeroEntry(uint8_t *Buf, uint64_t
> > GotEntryAddr,
> > + uint64_t PltEntryAddr) const {
> > + llvm_unreachable("not implemented");
> > +}
> > +
> > +void AMDGPUTargetInfo::writePltEntry(uint8_t *Buf, uint64_t GotAddr,
> > + uint64_t GotEntryAddr,
> > + uint64_t PltEntryAddr, int32_t Index,
> > + unsigned RelOff) const {
> > + llvm_unreachable("not implemented");
> > +}
> > +
> > +bool AMDGPUTargetInfo::relocNeedsGot(uint32_t Type, const SymbolBody &S)
> > const {
> > + return false;
> > +}
> > +
> > +bool AMDGPUTargetInfo::relocNeedsPlt(uint32_t Type, const SymbolBody &S)
> > const {
> > + return false;
> > +}
> > +
> > +void AMDGPUTargetInfo::relocateOne(uint8_t *Loc, uint8_t *BufEnd,
> > uint32_t Type,
> > + uint64_t P, uint64_t SA, uint64_t ZA,
> > + uint8_t *PairedLoc) const {
> > + llvm_unreachable("not implemented");
> > +}
> > +
> > template <class ELFT> MipsTargetInfo<ELFT>::MipsTargetInfo() {
> > PageSize = 65536;
> > GotHeaderEntriesNum = 2;
> >
> > Modified: lld/trunk/ELF/Writer.cpp
> > URL:
> > http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Writer.cpp?rev=257023&r1=257022&r2=257023&view=diff
> >
> > ==============================================================================
> > --- lld/trunk/ELF/Writer.cpp (original)
> > +++ lld/trunk/ELF/Writer.cpp Wed Jan 6 21:59:08 2016
> > @@ -975,6 +975,18 @@ static uint32_t toPhdrFlags(uint64_t Fla
> > return Ret;
> > }
> >
> > +/// For AMDGPU we need to use custom segment kinds in order to specify
> > which
> > +/// address space data should be loaded into.
> > +template <class ELFT>
> > +static uint32_t getAmdgpuPhdr(OutputSectionBase<ELFT> *Sec) {
> > + uint32_t Flags = Sec->getFlags();
> > + if (Flags & SHF_AMDGPU_HSA_CODE)
> > + return PT_AMDGPU_HSA_LOAD_CODE_AGENT;
> > + if ((Flags & SHF_AMDGPU_HSA_GLOBAL) && !(Flags & SHF_AMDGPU_HSA_AGENT))
> > + return PT_AMDGPU_HSA_LOAD_GLOBAL_PROGRAM;
> > + return PT_LOAD;
> > +}
> > +
> > template <class ELFT>
> > void Writer<ELFT>::updateRelro(Elf_Phdr *Cur, Elf_Phdr *GnuRelroPhdr,
> > uintX_t VA) {
> > @@ -1032,7 +1044,9 @@ template <class ELFT> void Writer<ELFT>:
> > if (PH->p_flags != Flags) {
> > // Flags changed. Create a new PT_LOAD.
> > PH = &Phdrs[++PhdrIdx];
> > - setPhdr(PH, PT_LOAD, Flags, FileOff, VA, 0,
> > Target->getPageSize());
> > + uint32_t PTType = (Config->EMachine != EM_AMDGPU) ?
> > (uint32_t)PT_LOAD
> > + :
> > getAmdgpuPhdr(Sec);
> > + setPhdr(PH, PTType, Flags, FileOff, VA, 0, Target->getPageSize());
> > }
> >
> > if (Sec->getFlags() & SHF_TLS) {
> >
> > Added: lld/trunk/test/ELF/amdgpu-entry.s
> > URL:
> > http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/amdgpu-entry.s?rev=257023&view=auto
> >
> > ==============================================================================
> > --- lld/trunk/test/ELF/amdgpu-entry.s (added)
> > +++ lld/trunk/test/ELF/amdgpu-entry.s Wed Jan 6 21:59:08 2016
> > @@ -0,0 +1,14 @@
> > +# RUN: llvm-mc -filetype=obj -triple=amdgcpu--amdgcn -mcpu=kaveri %s -o
> > %t.o
> > +# RUN: not lld -e kernel0 -flavor gnu %t.o -o %t
> > +
> > +.hsa_code_object_version 1,0
> > +.hsa_code_object_isa 7,0,0,"AMD","AMDGPU"
> > +
> > +.hsatext
> > +.globl kernel0
> > +.align 256
> > +.amdgpu_hsa_kernel kernel0
> > +kernel0:
> > + s_endpgm
> > +.Lfunc_end0:
> > + .size kernel0, .Lfunc_end0-kernel0
> >
> > Added: lld/trunk/test/ELF/amdgpu-globals.s
> > URL:
> > http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/amdgpu-globals.s?rev=257023&view=auto
> >
> > ==============================================================================
> > --- lld/trunk/test/ELF/amdgpu-globals.s (added)
> > +++ lld/trunk/test/ELF/amdgpu-globals.s Wed Jan 6 21:59:08 2016
> > @@ -0,0 +1,138 @@
> > +# RUN: llvm-mc -filetype=obj -triple=amdgcpu--amdgcn -mcpu=kaveri %s -o
> > %t.o
> > +# RUN: lld -flavor gnu %t.o -o %t
> > +# RUN: llvm-readobj -sections -symbols -program-headers %t | FileCheck %s
> > +
> > +# Requires: amdgpu
> > +
> > + .amdgpu_hsa_module_global module_global_program
> > + .size module_global_program, 4
> > + .hsadata_global_program
> > +module_global_program:
> > + .long 0 ; 0x0
> > +
> > + .amdgpu_hsa_program_global program_global_program
> > + .size program_global_program, 4
> > + .hsadata_global_program
> > +program_global_program:
> > + .long 0 ; 0x0
> > +
> > + .amdgpu_hsa_module_global module_global_agent
> > + .size module_global_agent, 4
> > + .hsadata_global_agent
> > +module_global_agent:
> > + .long 0 ; 0x0
> > +
> > + .amdgpu_hsa_program_global program_global_agent
> > + .size program_global_agent, 4
> > + .hsadata_global_agent
> > +program_global_agent:
> > + .long 0 ; 0x0
> > +
> > + .amdgpu_hsa_module_global module_global_readonly
> > + .size module_global_readonly, 4
> > + .hsatext
> > +module_global_readonly:
> > + .long 0 ; 0x0
> > +
> > + .amdgpu_hsa_program_global program_global_readonly
> > + .size program_global_readonly, 4
> > + .hsatext
> > +program_global_readonly:
> > + .long 0 ; 0x0
> > +
> > +# CHECK: Section {
> > +# CHECK: Name: .hsadata_global_program
> > +# CHECK: Type: SHT_PROGBITS (0x1)
> > +# CHECK: Flags [ (0x100003)
> > +# CHECK: SHF_ALLOC (0x2)
> > +# CHECK: SHF_AMDGPU_HSA_GLOBAL (0x100000)
> > +# CHECK: SHF_WRITE (0x1)
> > +# CHECK: ]
> > +# CHECK: Address: [[HSADATA_GLOBAL_PROGRAM_ADDR:[0-9xa-f]+]]
> > +# CHECK: }
> > +
> > +# CHECK: Section {
> > +# CHECK: Name: .hsadata_global_agent
> > +# CHECK: Type: SHT_PROGBITS (0x1)
> > +# CHECK: Flags [ (0x900003)
> > +# CHECK: SHF_ALLOC (0x2)
> > +# CHECK: SHF_AMDGPU_HSA_AGENT (0x800000)
> > +# CHECK: SHF_AMDGPU_HSA_GLOBAL (0x100000)
> > +# CHECK: SHF_WRITE (0x1)
> > +# CHECK: ]
> > +# CHECK: }
> > +
> > +# CHECK: Section {
> > +# CHECK: Name: .hsatext
> > +# CHECK: Type: SHT_PROGBITS
> > +# CHECK: Flags [ (0xC00007)
> > +# CHECK: SHF_ALLOC (0x2)
> > +# CHECK: SHF_AMDGPU_HSA_AGENT (0x800000)
> > +# CHECK: SHF_AMDGPU_HSA_CODE (0x400000)
> > +# CHECK: SHF_EXECINSTR (0x4)
> > +# CHECK: SHF_WRITE (0x1)
> > +# CHECK: ]
> > +# CHECK: Address: [[HSATEXT_ADDR:[0-9xa-f]+]]
> > +# CHECK: }
> > +
> > +# CHECK: Symbol {
> > +# CHECK: Name: module_global_agent
> > +# CHECK: Value: 0x0
> > +# CHECK: Size: 4
> > +# CHECK: Binding: Local
> > +# CHECK: Section: .hsadata_global_agent
> > +# CHECK: }
> > +
> > +# CHECK: Symbol {
> > +# CHECK: Name: module_global_program
> > +# CHECK: Value: 0x0
> > +# CHECK: Size: 4
> > +# CHECK: Binding: Local
> > +# CHECK: Section: .hsadata_global_program
> > +# CHECK: }
> > +
> > +# CHECK: Symbol {
> > +# CHECK: Name: module_global_readonly
> > +# CHECK: Value: 0x0
> > +# CHECK: Size: 4
> > +# CHECK: Binding: Local
> > +# CHECK: Type: Object
> > +# CHECK: Section: .hsatext
> > +# CHECK: }
> > +
> > +# CHECK: Symbol {
> > +# CHECK: Name: program_global_agent
> > +# CHECK: Value: 0x4
> > +# CHECK: Size: 4
> > +# CHECK: Binding: Global
> > +# CHECK: Type: Object
> > +# CHECK: Section: .hsadata_global_agent
> > +# CHECK: }
> > +
> > +# CHECK: Symbol {
> > +# CHECK: Name: program_global_program
> > +# CHECK: Value: 0x4
> > +# CHECK: Size: 4
> > +# CHECK: Binding: Global
> > +# CHECK: Type: Object
> > +# CHECK: Section: .hsadata_global_program
> > +# CHECK: }
> > +
> > +# CHECK: Symbol {
> > +# CHECK: Name: program_global_readonly
> > +# CHECK: Value: 0x4
> > +# CHECK: Size: 4
> > +# CHECK: Binding: Global
> > +# CHECK: Type: Object
> > +# CHECK: Section: .hsatext
> > +# CHECK: }
> > +
> > +# CHECK: ProgramHeader {
> > +# CHECK: Type: PT_AMDGPU_HSA_LOAD_GLOBAL_PROGRAM
> > +# CHECK: VirtualAddress: [[HSADATA_GLOBAL_PROGRAM_ADDR]]
> > +# CHECK: }
> > +
> > +# CHECK: ProgramHeader {
> > +# CHECK: Type: PT_AMDGPU_HSA_LOAD_CODE_AGENT
> > +# CHECK: VirtualAddress: [[HSATEXT_ADDR]]
> > +# CHECK: }
> >
> > Added: lld/trunk/test/ELF/amdgpu-kernels.s
> > URL:
> > http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/amdgpu-kernels.s?rev=257023&view=auto
> >
> > ==============================================================================
> > --- lld/trunk/test/ELF/amdgpu-kernels.s (added)
> > +++ lld/trunk/test/ELF/amdgpu-kernels.s Wed Jan 6 21:59:08 2016
> > @@ -0,0 +1,61 @@
> > +# RUN: llvm-mc -filetype=obj -triple=amdgcpu--amdgcn -mcpu=kaveri %s -o
> > %t.o
> > +# RUN: lld -flavor gnu %t.o -o %t
> > +# RUN: llvm-readobj -sections -symbols -program-headers %t | FileCheck %s
> > +
> > +.hsa_code_object_version 1,0
> > +.hsa_code_object_isa 7,0,0,"AMD","AMDGPU"
> > +
> > +.hsatext
> > +.globl kernel0
> > +.align 256
> > +.amdgpu_hsa_kernel kernel0
> > +kernel0:
> > + s_endpgm
> > +.Lfunc_end0:
> > + .size kernel0, .Lfunc_end0-kernel0
> > +
> > +.globl kernel1
> > +.align 256
> > +.amdgpu_hsa_kernel kernel1
> > +kernel1:
> > + s_endpgm
> > + s_endpgm
> > +.Lfunc_end1:
> > + .size kernel1, .Lfunc_end1-kernel1
> > +
> > +
> > +# CHECK: Section {
> > +# CHECK: Name: .hsatext
> > +# CHECK: Type: SHT_PROGBITS
> > +# CHECK: Flags [ (0xC00007)
> > +# CHECK: SHF_ALLOC (0x2)
> > +# CHECK: SHF_AMDGPU_HSA_AGENT (0x800000)
> > +# CHECK: SHF_AMDGPU_HSA_CODE (0x400000)
> > +# CHECK: SHF_EXECINSTR (0x4)
> > +# CHECK: SHF_WRITE (0x1)
> > +# CHECK: ]
> > +# CHECK: Address: [[HSATEXT_ADDR:[0-9xa-f]+]]
> > +# CHECK: }
> > +
> > +# CHECK: Symbol {
> > +# CHECK: Name: kernel0
> > +# CHECK: Value: 0x0
> > +# CHECK: Size: 4
> > +# CHECK: Binding: Global
> > +# CHECK: Type: AMDGPU_HSA_KERNEL
> > +# CHECK: Section: .hsatext
> > +# CHECK: }
> > +
> > +# CHECK: Symbol {
> > +# CHECK: Name: kernel1
> > +# CHECK: Value: 0x100
> > +# CHECK: Size: 8
> > +# CHECK: Binding: Global
> > +# CHECK: Type: AMDGPU_HSA_KERNEL
> > +# CHECK: Section: .hsatext
> > +# CHECK: }
> > +
> > +# CHECK: ProgramHeader {
> > +# CHECK: Type: PT_AMDGPU_HSA_LOAD_CODE_AGENT
> > +# CHECK: VirtualAddress: [[HSATEXT_ADDR]]
> > +# CHECK: }
> >
> >
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