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/MCSymbol.h"
  16 #include "llvm/MC/MCValue.h"
  17 #include "llvm/Support/ErrorHandling.h"
  18
  19 using namespace llvm;
  20
  21 namespace {
  22
  23 class AMDGPUELFObjectWriter : public MCELFObjectTargetWriter {
  24 public:
  25   AMDGPUELFObjectWriter(bool Is64Bit, bool HasRelocationAddend);
  26
  27 protected:
  28   unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
  29                         const MCFixup &Fixup, bool IsPCRel) const override;
  30 };
  31
  32
  33 } // end anonymous namespace
  34
  35 AMDGPUELFObjectWriter::AMDGPUELFObjectWriter(bool Is64Bit,
  36                                              bool HasRelocationAddend)
  37   : MCELFObjectTargetWriter(Is64Bit,
  38                             ELF::ELFOSABI_AMDGPU_HSA,
  39                             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       return ELF::R_AMDGPU_ABS32_LO;
  51
  52     if (SymA->getSymbol().getName() == "SCRATCH_RSRC_DWORD1")
  53       return ELF::R_AMDGPU_ABS32_HI;
  54   }
  55
  56   switch (Target.getAccessVariant()) {
  57   default:
  58     break;
  59   case MCSymbolRefExpr::VK_GOTPCREL:
  60     return ELF::R_AMDGPU_GOTPCREL;
  61   case MCSymbolRefExpr::VK_AMDGPU_GOTPCREL32_LO:
  62     return ELF::R_AMDGPU_GOTPCREL32_LO;
  63   case MCSymbolRefExpr::VK_AMDGPU_GOTPCREL32_HI:
  64     return ELF::R_AMDGPU_GOTPCREL32_HI;
  65   case MCSymbolRefExpr::VK_AMDGPU_REL32_LO:
  66     return ELF::R_AMDGPU_REL32_LO;
  67   case MCSymbolRefExpr::VK_AMDGPU_REL32_HI:
  68     return ELF::R_AMDGPU_REL32_HI;
  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 MCObjectWriter *llvm::createAMDGPUELFObjectWriter(bool Is64Bit,
  86                                                   bool HasRelocationAddend,
  87                                                   raw_pwrite_stream &OS) {
  88   MCELFObjectTargetWriter *MOTW =
  89       new AMDGPUELFObjectWriter(Is64Bit, HasRelocationAddend);
  90   return createELFObjectWriter(MOTW, OS, true);
  91 }