R600/SI: Use ELF64 format instead of ELF32

[• rafael]

LGTM

lib/Target/R600/MCTargetDesc/AMDGPUAsmBackend.cpp

130

You don't need this private:

lib/Target/R600/MCTargetDesc/AMDGPUAsmBackend.cpp

 
 //===----------------------------------------------------------------------===//
 // ELFAMDGPUAsmBackend class
 //===----------------------------------------------------------------------===//
 
 namespace {
 
 class ELFAMDGPUAsmBackend : public AMDGPUAsmBackend {
+private:
+  bool Is64Bit;
 public:
-  ELFAMDGPUAsmBackend(const Target &T) : AMDGPUAsmBackend(T) { }
+  ELFAMDGPUAsmBackend(const Target &T, bool Is64Bit) :
+      AMDGPUAsmBackend(T), Is64Bit(Is64Bit) { }
 
   MCObjectWriter *createObjectWriter(raw_pwrite_stream &OS) const override {
-    return createAMDGPUELFObjectWriter(OS);
+    return createAMDGPUELFObjectWriter(Is64Bit, OS);
   }
 };
 
 } // end anonymous namespace
 
 MCAsmBackend *llvm::createAMDGPUAsmBackend(const Target &T,
                                            const MCRegisterInfo &MRI,
                                            StringRef TT,
                                            StringRef CPU) {
-  return new ELFAMDGPUAsmBackend(T);
+  Triple TargetTriple(TT);
+
+  // Use 64-bit ELF for amdgcn
+  return new ELFAMDGPUAsmBackend(T, TargetTriple.getArch() == Triple::amdgcn);
 }

lib/Target/R600/MCTargetDesc/AMDGPUELFObjectWriter.cpp

 #include "llvm/MC/MCFixup.h"
 
 using namespace llvm;
 
 namespace {
 
 class AMDGPUELFObjectWriter : public MCELFObjectTargetWriter {
 public:
-  AMDGPUELFObjectWriter();
+  AMDGPUELFObjectWriter(bool Is64Bit);
 protected:
   unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
                         bool IsPCRel) const override {
     return Fixup.getKind();
   }
 
 };
 
 
 } // End anonymous namespace
 
-AMDGPUELFObjectWriter::AMDGPUELFObjectWriter()
-  : MCELFObjectTargetWriter(false, 0, ELF::EM_AMDGPU, false) { }
+AMDGPUELFObjectWriter::AMDGPUELFObjectWriter(bool Is64Bit)
+  : MCELFObjectTargetWriter(Is64Bit, 0, ELF::EM_AMDGPU, false) { }
 
-MCObjectWriter *llvm::createAMDGPUELFObjectWriter(raw_pwrite_stream &OS) {
-  MCELFObjectTargetWriter *MOTW = new AMDGPUELFObjectWriter();
+MCObjectWriter *llvm::createAMDGPUELFObjectWriter(bool Is64Bit, raw_pwrite_stream &OS) {
+  MCELFObjectTargetWriter *MOTW = new AMDGPUELFObjectWriter(Is64Bit);
   return createELFObjectWriter(MOTW, OS, true);
 }

lib/Target/R600/MCTargetDesc/AMDGPUMCTargetDesc.h

 
 MCCodeEmitter *createSIMCCodeEmitter(const MCInstrInfo &MCII,
                                      const MCRegisterInfo &MRI,
                                      MCContext &Ctx);
 
 MCAsmBackend *createAMDGPUAsmBackend(const Target &T, const MCRegisterInfo &MRI,
                                      StringRef TT, StringRef CPU);
 
-MCObjectWriter *createAMDGPUELFObjectWriter(raw_pwrite_stream &OS);
+MCObjectWriter *createAMDGPUELFObjectWriter(bool Is64Bit,
+                                            raw_pwrite_stream &OS);
 } // End llvm namespace
 
 #define GET_REGINFO_ENUM
 #include "AMDGPUGenRegisterInfo.inc"
 
 #define GET_INSTRINFO_ENUM
 #include "AMDGPUGenInstrInfo.inc"
 
 #define GET_SUBTARGETINFO_ENUM
 #include "AMDGPUGenSubtargetInfo.inc"
 
 #endif

test/CodeGen/R600/elf.ll

 ; RUN: llc < %s -march=amdgcn -mcpu=SI -verify-machineinstrs -filetype=obj | llvm-readobj -s -symbols -file-headers - | FileCheck --check-prefix=ELF %s
 ; RUN: llc < %s -march=amdgcn -mcpu=SI -verify-machineinstrs -o - | FileCheck --check-prefix=CONFIG --check-prefix=TYPICAL %s
 ; RUN: llc < %s -march=amdgcn -mcpu=tonga -verify-machineinstrs -filetype=obj | llvm-readobj -s -symbols -file-headers - | FileCheck --check-prefix=ELF %s
 ; RUN: llc < %s -march=amdgcn -mcpu=tonga -verify-machineinstrs -o - | FileCheck --check-prefix=CONFIG --check-prefix=TONGA %s
 ; RUN: llc < %s -march=amdgcn -mcpu=carrizo -verify-machineinstrs -filetype=obj | llvm-readobj -s -symbols -file-headers - | FileCheck --check-prefix=ELF %s
 ; RUN: llc < %s -march=amdgcn -mcpu=carrizo -verify-machineinstrs -o - | FileCheck --check-prefix=CONFIG --check-prefix=TYPICAL %s
 
 ; Test that we don't try to produce a COFF file on windows
 ; RUN: llc < %s -mtriple=amdgcn-pc-mingw -mcpu=SI -verify-machineinstrs -filetype=obj | llvm-readobj -s -symbols -file-headers - | FileCheck --check-prefix=ELF %s
 
-; ELF: Format: ELF32
+; ELF: Format: ELF64
 ; ELF: Machine: EM_AMDGPU (0xE0)
 ; ELF: Name: .AMDGPU.config
 ; ELF: Type: SHT_PROGBITS
 
 ; ELF: Symbol {
 ; ELF: Name: test
 ; ELF: Binding: Global