AArch64MCAsmInfo.cpp revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f 
1//===-- AArch64MCAsmInfo.cpp - AArch64 asm properties ---------------------===//
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// This file contains the declarations of the AArch64MCAsmInfo properties.
11//
12//===----------------------------------------------------------------------===//
13
14#include "AArch64MCAsmInfo.h"
15#include "llvm/ADT/Triple.h"
16#include "llvm/MC/MCExpr.h"
17#include "llvm/MC/MCContext.h"
18#include "llvm/MC/MCStreamer.h"
19#include "llvm/Support/CommandLine.h"
20using namespace llvm;
21
22enum AsmWriterVariantTy {
23  Default = -1,
24  Generic = 0,
25  Apple = 1
26};
27
28static cl::opt<AsmWriterVariantTy> AsmWriterVariant(
29    "aarch64-neon-syntax", cl::init(Default),
30    cl::desc("Choose style of NEON code to emit from AArch64 backend:"),
31    cl::values(clEnumValN(Generic, "generic", "Emit generic NEON assembly"),
32               clEnumValN(Apple, "apple", "Emit Apple-style NEON assembly"),
33               clEnumValEnd));
34
35AArch64MCAsmInfoDarwin::AArch64MCAsmInfoDarwin() {
36  // We prefer NEON instructions to be printed in the short form.
37  AssemblerDialect = AsmWriterVariant == Default ? 1 : AsmWriterVariant;
38
39  PrivateGlobalPrefix = "L";
40  SeparatorString = "%%";
41  CommentString = ";";
42  PointerSize = CalleeSaveStackSlotSize = 8;
43
44  AlignmentIsInBytes = false;
45  UsesELFSectionDirectiveForBSS = true;
46  SupportsDebugInformation = true;
47  UseDataRegionDirectives = true;
48
49  ExceptionsType = ExceptionHandling::DwarfCFI;
50}
51
52const 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
67AArch64MCAsmInfoELF::AArch64MCAsmInfoELF(StringRef TT) {
68  Triple T(TT);
69  if (T.getArch() == Triple::arm64_be || T.getArch() == Triple::aarch64_be)
70    IsLittleEndian = false;
71
72  // We prefer NEON instructions to be printed in the short form.
73  AssemblerDialect = AsmWriterVariant == Default ? 0 : AsmWriterVariant;
74
75  PointerSize = 8;
76
77  // ".comm align is in bytes but .align is pow-2."
78  AlignmentIsInBytes = false;
79
80  CommentString = "//";
81  PrivateGlobalPrefix = ".L";
82  Code32Directive = ".code\t32";
83
84  Data16bitsDirective = "\t.hword\t";
85  Data32bitsDirective = "\t.word\t";
86  Data64bitsDirective = "\t.xword\t";
87
88  UseDataRegionDirectives = false;
89
90  WeakRefDirective = "\t.weak\t";
91
92  HasLEB128 = true;
93  SupportsDebugInformation = true;
94
95  // Exceptions handling
96  ExceptionsType = ExceptionHandling::DwarfCFI;
97
98  UseIntegratedAssembler = true;
99}
100