lib/Target/RISCV/MCTargetDesc/RISCVMCAsmInfo.cpp

   1 //===-- RISCVMCAsmInfo.cpp - RISCV Asm properties -------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file contains the declarations of the RISCVMCAsmInfo properties.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "RISCVMCAsmInfo.h"
  14 #include "MCTargetDesc/RISCVMCExpr.h"
  15 #include "llvm/ADT/Triple.h"
  16 #include "llvm/BinaryFormat/Dwarf.h"
  17 #include "llvm/MC/MCStreamer.h"
  18 using namespace llvm;
  19
  20 void RISCVMCAsmInfo::anchor() {}
  21
  22 RISCVMCAsmInfo::RISCVMCAsmInfo(const Triple &TT) {
  23   CodePointerSize = CalleeSaveStackSlotSize = TT.isArch64Bit() ? 8 : 4;
  24   CommentString = "#";
  25   AlignmentIsInBytes = false;
  26   SupportsDebugInformation = true;
  27   ExceptionsType = ExceptionHandling::DwarfCFI;
  28   Data16bitsDirective = "\t.half\t";
  29   Data32bitsDirective = "\t.word\t";
  30 }
  31
  32 const MCExpr *RISCVMCAsmInfo::getExprForFDESymbol(const MCSymbol *Sym,
  33                                                   unsigned Encoding,
  34                                                   MCStreamer &Streamer) const {
  35   if (!(Encoding & dwarf::DW_EH_PE_pcrel))
  36     return MCAsmInfo::getExprForFDESymbol(Sym, Encoding, Streamer);
  37
  38   // The default symbol subtraction results in an ADD/SUB relocation pair.
  39   // Processing this relocation pair is problematic when linker relaxation is
  40   // enabled, so we follow binutils in using the R_RISCV_32_PCREL relocation
  41   // for the FDE initial location.
  42   MCContext &Ctx = Streamer.getContext();
  43   const MCExpr *ME =
  44       MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_None, Ctx);
  45   assert(Encoding & dwarf::DW_EH_PE_sdata4 && "Unexpected encoding");
  46   return RISCVMCExpr::create(ME, RISCVMCExpr::VK_RISCV_32_PCREL, Ctx);
  47 }