1 //===-- X86MCAsmInfo.cpp - X86 asm properties -----------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains the declarations of the X86MCAsmInfo properties.
12 //===----------------------------------------------------------------------===//
14 #include "X86MCAsmInfo.h"
15 #include "llvm/ADT/Triple.h"
16 #include "llvm/MC/MCContext.h"
17 #include "llvm/MC/MCExpr.h"
18 #include "llvm/MC/MCSectionELF.h"
19 #include "llvm/MC/MCStreamer.h"
20 #include "llvm/Support/CommandLine.h"
21 #include "llvm/Support/ELF.h"
24 enum AsmWriterFlavorTy {
25 // Note: This numbering has to match the GCC assembler dialects for inline
26 // asm alternatives to work right.
30 static cl::opt<AsmWriterFlavorTy>
31 AsmWriterFlavor("x86-asm-syntax", cl::init(ATT),
32 cl::desc("Choose style of code to emit from X86 backend:"),
33 cl::values(clEnumValN(ATT, "att", "Emit AT&T-style assembly"),
34 clEnumValN(Intel, "intel", "Emit Intel-style assembly"),
38 MarkedJTDataRegions("mark-data-regions", cl::init(false),
39 cl::desc("Mark code section jump table data regions."),
42 void X86MCAsmInfoDarwin::anchor() { }
44 X86MCAsmInfoDarwin::X86MCAsmInfoDarwin(const Triple &T) {
45 bool is64Bit = T.getArch() == Triple::x86_64;
47 PointerSize = CalleeSaveStackSlotSize = 8;
49 AssemblerDialect = AsmWriterFlavor;
51 TextAlignFillValue = 0x90;
54 Data64bitsDirective = 0; // we can't emit a 64-bit unit
56 // Use ## as a comment string so that .s files generated by llvm can go
57 // through the GCC preprocessor without causing an error. This is needed
58 // because "clang foo.s" runs the C preprocessor, which is usually reserved
59 // for .S files on other systems. Perhaps this is because the file system
60 // wasn't always case preserving or something.
63 SupportsDebugInformation = true;
64 UseDataRegionDirectives = MarkedJTDataRegions;
66 // Exceptions handling
67 ExceptionsType = ExceptionHandling::DwarfCFI;
70 X86_64MCAsmInfoDarwin::X86_64MCAsmInfoDarwin(const Triple &Triple)
71 : X86MCAsmInfoDarwin(Triple) {
74 void X86ELFMCAsmInfo::anchor() { }
76 X86ELFMCAsmInfo::X86ELFMCAsmInfo(const Triple &T) {
77 bool is64Bit = T.getArch() == Triple::x86_64;
78 bool isX32 = T.getEnvironment() == Triple::GNUX32;
80 // For ELF, x86-64 pointer size depends on the ABI.
81 // For x86-64 without the x32 ABI, pointer size is 8. For x86 and for x86-64
82 // with the x32 ABI, pointer size remains the default 4.
83 PointerSize = (is64Bit && !isX32) ? 8 : 4;
85 // OTOH, stack slot size is always 8 for x86-64, even with the x32 ABI.
86 CalleeSaveStackSlotSize = is64Bit ? 8 : 4;
88 AssemblerDialect = AsmWriterFlavor;
90 TextAlignFillValue = 0x90;
92 PrivateGlobalPrefix = ".L";
94 // Set up DWARF directives
95 HasLEB128 = true; // Target asm supports leb128 directives (little-endian)
98 SupportsDebugInformation = true;
100 // Exceptions handling
101 ExceptionsType = ExceptionHandling::DwarfCFI;
103 // OpenBSD and Bitrig have buggy support for .quad in 32-bit mode, just split
105 if ((T.getOS() == Triple::OpenBSD || T.getOS() == Triple::Bitrig) &&
106 T.getArch() == Triple::x86)
107 Data64bitsDirective = 0;
111 X86_64MCAsmInfoDarwin::getExprForPersonalitySymbol(const MCSymbol *Sym,
113 MCStreamer &Streamer) const {
114 MCContext &Context = Streamer.getContext();
116 MCSymbolRefExpr::Create(Sym, MCSymbolRefExpr::VK_GOTPCREL, Context);
117 const MCExpr *Four = MCConstantExpr::Create(4, Context);
118 return MCBinaryExpr::CreateAdd(Res, Four, Context);
121 const MCSection *X86ELFMCAsmInfo::
122 getNonexecutableStackSection(MCContext &Ctx) const {
123 return Ctx.getELFSection(".note.GNU-stack", ELF::SHT_PROGBITS,
124 0, SectionKind::getMetadata());
127 void X86MCAsmInfoMicrosoft::anchor() { }
129 X86MCAsmInfoMicrosoft::X86MCAsmInfoMicrosoft(const Triple &Triple) {
130 if (Triple.getArch() == Triple::x86_64) {
132 PrivateGlobalPrefix = ".L";
135 AssemblerDialect = AsmWriterFlavor;
137 TextAlignFillValue = 0x90;
139 AllowAtInName = true;
142 void X86MCAsmInfoGNUCOFF::anchor() { }
144 X86MCAsmInfoGNUCOFF::X86MCAsmInfoGNUCOFF(const Triple &Triple) {
145 if (Triple.getArch() == Triple::x86_64) {
147 PrivateGlobalPrefix = ".L";
150 AssemblerDialect = AsmWriterFlavor;
152 TextAlignFillValue = 0x90;
154 // Exceptions handling
155 ExceptionsType = ExceptionHandling::DwarfCFI;