Subzero. Native 64-bit int arithmetic on x86-64.

src/IceELFSection.h

 //===- subzero/src/IceELFSection.h - Model of ELF sections ------*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 344 matching lines @@
   for (const AssemblerFixup &Fixup : Fixups) {
     const ELFSym *Symbol;
     if (Fixup.isNullSymbol())
       Symbol = SymTab->getNullSymbol();
     else
       Symbol = SymTab->findSymbol(Fixup.symbol(&Ctx));
     if (!Symbol)
       llvm::report_fatal_error("Missing symbol mentioned in reloc");
 
     if (IsELF64) {
-      llvm_unreachable(
-          "Not tested -- check that Fixup.offset() is correct even for pc-rel");
+      // TODO(jpp): check that Fixup.offset() is correct even for pc-rel.
       Elf64_Rela Rela;
       Rela.r_offset = Fixup.position();
       Rela.setSymbolAndType(Symbol->getNumber(), Fixup.kind());
       Rela.r_addend = Fixup.offset();
       Str.writeAddrOrOffset<IsELF64>(Rela.r_offset);
       Str.writeELFXword<IsELF64>(Rela.r_info);
       Str.writeELFXword<IsELF64>(Rela.r_addend);
     } else {
       Elf32_Rel Rel;
       Rel.r_offset = Fixup.position();
       Rel.setSymbolAndType(Symbol->getNumber(), Fixup.kind());
       Str.writeAddrOrOffset<IsELF64>(Rel.r_offset);
       Str.writeELFWord<IsELF64>(Rel.r_info);
     }
   }
 }
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEELFSECTION_H