1 //===- AMDGPUELFObjectWriter.cpp - AMDGPU ELF Writer ----------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 #include "AMDGPUMCTargetDesc.h"
11 #include "llvm/BinaryFormat/ELF.h"
12 #include "llvm/MC/MCELFObjectWriter.h"
13 #include "llvm/MC/MCExpr.h"
14 #include "llvm/MC/MCFixup.h"
15 #include "llvm/MC/MCObjectWriter.h"
16 #include "llvm/MC/MCSymbol.h"
17 #include "llvm/MC/MCValue.h"
18 #include "llvm/Support/ErrorHandling.h"
19
20 using namespace llvm;
21
22 namespace {
23
24 class AMDGPUELFObjectWriter : public MCELFObjectTargetWriter {
25 public:
26 AMDGPUELFObjectWriter(bool Is64Bit, uint8_t OSABI, bool HasRelocationAddend);
27
28 protected:
29 unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
30 const MCFixup &Fixup, bool IsPCRel) const override;
31 };
32
33
34 } // end anonymous namespace
35
AMDGPUELFObjectWriter(bool Is64Bit,uint8_t OSABI,bool HasRelocationAddend)36 AMDGPUELFObjectWriter::AMDGPUELFObjectWriter(bool Is64Bit,
37 uint8_t OSABI,
38 bool HasRelocationAddend)
39 : MCELFObjectTargetWriter(Is64Bit, OSABI, ELF::EM_AMDGPU,
40 HasRelocationAddend) {}
41
getRelocType(MCContext & Ctx,const MCValue & Target,const MCFixup & Fixup,bool IsPCRel) const42 unsigned AMDGPUELFObjectWriter::getRelocType(MCContext &Ctx,
43 const MCValue &Target,
44 const MCFixup &Fixup,
45 bool IsPCRel) const {
46 if (const auto *SymA = Target.getSymA()) {
47 // SCRATCH_RSRC_DWORD[01] is a special global variable that represents
48 // the scratch buffer.
49 if (SymA->getSymbol().getName() == "SCRATCH_RSRC_DWORD0" ||
50 SymA->getSymbol().getName() == "SCRATCH_RSRC_DWORD1")
51 return ELF::R_AMDGPU_ABS32_LO;
52 }
53
54 switch (Target.getAccessVariant()) {
55 default:
56 break;
57 case MCSymbolRefExpr::VK_GOTPCREL:
58 return ELF::R_AMDGPU_GOTPCREL;
59 case MCSymbolRefExpr::VK_AMDGPU_GOTPCREL32_LO:
60 return ELF::R_AMDGPU_GOTPCREL32_LO;
61 case MCSymbolRefExpr::VK_AMDGPU_GOTPCREL32_HI:
62 return ELF::R_AMDGPU_GOTPCREL32_HI;
63 case MCSymbolRefExpr::VK_AMDGPU_REL32_LO:
64 return ELF::R_AMDGPU_REL32_LO;
65 case MCSymbolRefExpr::VK_AMDGPU_REL32_HI:
66 return ELF::R_AMDGPU_REL32_HI;
67 case MCSymbolRefExpr::VK_AMDGPU_REL64:
68 return ELF::R_AMDGPU_REL64;
69 }
70
71 switch (Fixup.getKind()) {
72 default: break;
73 case FK_PCRel_4:
74 return ELF::R_AMDGPU_REL32;
75 case FK_Data_4:
76 case FK_SecRel_4:
77 return ELF::R_AMDGPU_ABS32;
78 case FK_Data_8:
79 return ELF::R_AMDGPU_ABS64;
80 }
81
82 llvm_unreachable("unhandled relocation type");
83 }
84
85 std::unique_ptr<MCObjectTargetWriter>
createAMDGPUELFObjectWriter(bool Is64Bit,uint8_t OSABI,bool HasRelocationAddend)86 llvm::createAMDGPUELFObjectWriter(bool Is64Bit, uint8_t OSABI,
87 bool HasRelocationAddend) {
88 return llvm::make_unique<AMDGPUELFObjectWriter>(Is64Bit, OSABI,
89 HasRelocationAddend);
90 }
91