contrib/llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUELFObjectWriter.cpp

   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
  36 AMDGPUELFObjectWriter::AMDGPUELFObjectWriter(bool Is64Bit,
  37                                              uint8_t OSABI,
  38                                              bool HasRelocationAddend)
  39   : MCELFObjectTargetWriter(Is64Bit, OSABI, ELF::EM_AMDGPU,
  40                             HasRelocationAddend) {}
  41
  42 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>
  86 llvm::createAMDGPUELFObjectWriter(bool Is64Bit, uint8_t OSABI,
  87                                   bool HasRelocationAddend) {
  88   return llvm::make_unique<AMDGPUELFObjectWriter>(Is64Bit, OSABI,
  89                                                   HasRelocationAddend);
  90 }