lib/Target/AArch64/MCTargetDesc/AArch64MCAsmInfo.cpp

   1 //===-- AArch64MCAsmInfo.cpp - AArch64 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 AArch64MCAsmInfo properties.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "AArch64MCAsmInfo.h"
  14 #include "llvm/ADT/Triple.h"
  15 #include "llvm/MC/MCContext.h"
  16 #include "llvm/MC/MCExpr.h"
  17 #include "llvm/MC/MCStreamer.h"
  18 #include "llvm/Support/CommandLine.h"
  19 using namespace llvm;
  20
  21 enum AsmWriterVariantTy {
  22   Default = -1,
  23   Generic = 0,
  24   Apple = 1
  25 };
  26
  27 static cl::opt<AsmWriterVariantTy> AsmWriterVariant(
  28     "aarch64-neon-syntax", cl::init(Default),
  29     cl::desc("Choose style of NEON code to emit from AArch64 backend:"),
  30     cl::values(clEnumValN(Generic, "generic", "Emit generic NEON assembly"),
  31                clEnumValN(Apple, "apple", "Emit Apple-style NEON assembly")));
  32
  33 AArch64MCAsmInfoDarwin::AArch64MCAsmInfoDarwin() {
  34   // We prefer NEON instructions to be printed in the short, Apple-specific
  35   // form when targeting Darwin.
  36   AssemblerDialect = AsmWriterVariant == Default ? Apple : AsmWriterVariant;
  37
  38   PrivateGlobalPrefix = "L";
  39   PrivateLabelPrefix = "L";
  40   SeparatorString = "%%";
  41   CommentString = ";";
  42   CodePointerSize = CalleeSaveStackSlotSize = 8;
  43
  44   AlignmentIsInBytes = false;
  45   UsesELFSectionDirectiveForBSS = true;
  46   SupportsDebugInformation = true;
  47   UseDataRegionDirectives = true;
  48
  49   ExceptionsType = ExceptionHandling::DwarfCFI;
  50 }
  51
  52 const MCExpr *AArch64MCAsmInfoDarwin::getExprForPersonalitySymbol(
  53     const MCSymbol *Sym, unsigned Encoding, MCStreamer &Streamer) const {
  54   // On Darwin, we can reference dwarf symbols with foo@GOT-., which
  55   // is an indirect pc-relative reference. The default implementation
  56   // won't reference using the GOT, so we need this target-specific
  57   // version.
  58   MCContext &Context = Streamer.getContext();
  59   const MCExpr *Res =
  60       MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_GOT, Context);
  61   MCSymbol *PCSym = Context.createTempSymbol();
  62   Streamer.EmitLabel(PCSym);
  63   const MCExpr *PC = MCSymbolRefExpr::create(PCSym, Context);
  64   return MCBinaryExpr::createSub(Res, PC, Context);
  65 }
  66
  67 AArch64MCAsmInfoELF::AArch64MCAsmInfoELF(const Triple &T) {
  68   if (T.getArch() == Triple::aarch64_be)
  69     IsLittleEndian = false;
  70
  71   // We prefer NEON instructions to be printed in the generic form when
  72   // targeting ELF.
  73   AssemblerDialect = AsmWriterVariant == Default ? Generic : AsmWriterVariant;
  74
  75   CodePointerSize = 8;
  76
  77   // ".comm align is in bytes but .align is pow-2."
  78   AlignmentIsInBytes = false;
  79
  80   CommentString = "//";
  81   PrivateGlobalPrefix = ".L";
  82   PrivateLabelPrefix = ".L";
  83   Code32Directive = ".code\t32";
  84
  85   Data16bitsDirective = "\t.hword\t";
  86   Data32bitsDirective = "\t.word\t";
  87   Data64bitsDirective = "\t.xword\t";
  88
  89   UseDataRegionDirectives = false;
  90
  91   WeakRefDirective = "\t.weak\t";
  92
  93   SupportsDebugInformation = true;
  94
  95   // Exceptions handling
  96   ExceptionsType = ExceptionHandling::DwarfCFI;
  97
  98   UseIntegratedAssembler = true;
  99
 100   HasIdentDirective = true;
 101 }
 102
 103 AArch64MCAsmInfoMicrosoftCOFF::AArch64MCAsmInfoMicrosoftCOFF() {
 104   PrivateGlobalPrefix = ".L";
 105   PrivateLabelPrefix = ".L";
 106
 107   Data16bitsDirective = "\t.hword\t";
 108   Data32bitsDirective = "\t.word\t";
 109   Data64bitsDirective = "\t.xword\t";
 110
 111   AlignmentIsInBytes = false;
 112   SupportsDebugInformation = true;
 113   CodePointerSize = 8;
 114
 115   CommentString = ";";
 116   ExceptionsType = ExceptionHandling::WinEH;
 117   WinEHEncodingType = WinEH::EncodingType::Itanium;
 118 }
 119
 120 AArch64MCAsmInfoGNUCOFF::AArch64MCAsmInfoGNUCOFF() {
 121   PrivateGlobalPrefix = ".L";
 122   PrivateLabelPrefix = ".L";
 123
 124   Data16bitsDirective = "\t.hword\t";
 125   Data32bitsDirective = "\t.word\t";
 126   Data64bitsDirective = "\t.xword\t";
 127
 128   AlignmentIsInBytes = false;
 129   SupportsDebugInformation = true;
 130   CodePointerSize = 8;
 131
 132   CommentString = "//";
 133   ExceptionsType = ExceptionHandling::WinEH;
 134   WinEHEncodingType = WinEH::EncodingType::Itanium;
 135 }