AArch64MCAsmInfo.cpp revision 360784 
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"
19using namespace llvm;
20
21enum AsmWriterVariantTy {
22  Default = -1,
23  Generic = 0,
24  Apple = 1
25};
26
27static 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
33AArch64MCAsmInfoDarwin::AArch64MCAsmInfoDarwin(bool IsILP32) {
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  CalleeSaveStackSlotSize = 8;
43  CodePointerSize = IsILP32 ? 4 : 8;
44
45  AlignmentIsInBytes = false;
46  UsesELFSectionDirectiveForBSS = true;
47  SupportsDebugInformation = true;
48  UseDataRegionDirectives = true;
49
50  ExceptionsType = ExceptionHandling::DwarfCFI;
51}
52
53const MCExpr *AArch64MCAsmInfoDarwin::getExprForPersonalitySymbol(
54    const MCSymbol *Sym, unsigned Encoding, MCStreamer &Streamer) const {
55  // On Darwin, we can reference dwarf symbols with foo@GOT-., which
56  // is an indirect pc-relative reference. The default implementation
57  // won't reference using the GOT, so we need this target-specific
58  // version.
59  MCContext &Context = Streamer.getContext();
60  const MCExpr *Res =
61      MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_GOT, Context);
62  MCSymbol *PCSym = Context.createTempSymbol();
63  Streamer.EmitLabel(PCSym);
64  const MCExpr *PC = MCSymbolRefExpr::create(PCSym, Context);
65  return MCBinaryExpr::createSub(Res, PC, Context);
66}
67
68AArch64MCAsmInfoELF::AArch64MCAsmInfoELF(const Triple &T) {
69  if (T.getArch() == Triple::aarch64_be)
70    IsLittleEndian = false;
71
72  // We prefer NEON instructions to be printed in the generic form when
73  // targeting ELF.
74  AssemblerDialect = AsmWriterVariant == Default ? Generic : AsmWriterVariant;
75
76  CodePointerSize = 8;
77
78  // ".comm align is in bytes but .align is pow-2."
79  AlignmentIsInBytes = false;
80
81  CommentString = "//";
82  PrivateGlobalPrefix = ".L";
83  PrivateLabelPrefix = ".L";
84  Code32Directive = ".code\t32";
85
86  Data16bitsDirective = "\t.hword\t";
87  Data32bitsDirective = "\t.word\t";
88  Data64bitsDirective = "\t.xword\t";
89
90  UseDataRegionDirectives = false;
91
92  WeakRefDirective = "\t.weak\t";
93
94  SupportsDebugInformation = true;
95
96  // Exceptions handling
97  ExceptionsType = ExceptionHandling::DwarfCFI;
98
99  UseIntegratedAssembler = true;
100
101  HasIdentDirective = true;
102}
103
104AArch64MCAsmInfoMicrosoftCOFF::AArch64MCAsmInfoMicrosoftCOFF() {
105  PrivateGlobalPrefix = ".L";
106  PrivateLabelPrefix = ".L";
107
108  Data16bitsDirective = "\t.hword\t";
109  Data32bitsDirective = "\t.word\t";
110  Data64bitsDirective = "\t.xword\t";
111
112  AlignmentIsInBytes = false;
113  SupportsDebugInformation = true;
114  CodePointerSize = 8;
115
116  CommentString = ";";
117  ExceptionsType = ExceptionHandling::WinEH;
118  WinEHEncodingType = WinEH::EncodingType::Itanium;
119}
120
121AArch64MCAsmInfoGNUCOFF::AArch64MCAsmInfoGNUCOFF() {
122  PrivateGlobalPrefix = ".L";
123  PrivateLabelPrefix = ".L";
124
125  Data16bitsDirective = "\t.hword\t";
126  Data32bitsDirective = "\t.word\t";
127  Data64bitsDirective = "\t.xword\t";
128
129  AlignmentIsInBytes = false;
130  SupportsDebugInformation = true;
131  CodePointerSize = 8;
132
133  CommentString = "//";
134  ExceptionsType = ExceptionHandling::WinEH;
135  WinEHEncodingType = WinEH::EncodingType::Itanium;
136}
137