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")));
37 MarkedJTDataRegions("mark-data-regions", cl::init(true),
38 cl::desc("Mark code section jump table data regions."),
41 void X86MCAsmInfoDarwin::anchor() { }
43 X86MCAsmInfoDarwin::X86MCAsmInfoDarwin(const Triple &T) {
44 bool is64Bit = T.getArch() == Triple::x86_64;
46 CodePointerSize = CalleeSaveStackSlotSize = 8;
48 AssemblerDialect = AsmWriterFlavor;
50 TextAlignFillValue = 0x90;
53 Data64bitsDirective = nullptr; // we can't emit a 64-bit unit
55 // Use ## as a comment string so that .s files generated by llvm can go
56 // through the GCC preprocessor without causing an error. This is needed
57 // because "clang foo.s" runs the C preprocessor, which is usually reserved
58 // for .S files on other systems. Perhaps this is because the file system
59 // wasn't always case preserving or something.
62 SupportsDebugInformation = true;
63 UseDataRegionDirectives = MarkedJTDataRegions;
65 // Exceptions handling
66 ExceptionsType = ExceptionHandling::DwarfCFI;
68 // old assembler lacks some directives
69 // FIXME: this should really be a check on the assembler characteristics
70 // rather than OS version
71 if (T.isMacOSX() && T.isMacOSXVersionLT(10, 6))
72 HasWeakDefCanBeHiddenDirective = false;
74 // Assume ld64 is new enough that the abs-ified FDE relocs may be used
75 // (actually, must, since otherwise the non-extern relocations we produce
76 // overwhelm ld64's tiny little mind and it fails).
77 DwarfFDESymbolsUseAbsDiff = true;
79 UseIntegratedAssembler = true;
82 X86_64MCAsmInfoDarwin::X86_64MCAsmInfoDarwin(const Triple &Triple)
83 : X86MCAsmInfoDarwin(Triple) {
86 void X86ELFMCAsmInfo::anchor() { }
88 X86ELFMCAsmInfo::X86ELFMCAsmInfo(const Triple &T) {
89 bool is64Bit = T.getArch() == Triple::x86_64;
90 bool isX32 = T.getEnvironment() == Triple::GNUX32;
92 // For ELF, x86-64 pointer size depends on the ABI.
93 // For x86-64 without the x32 ABI, pointer size is 8. For x86 and for x86-64
94 // with the x32 ABI, pointer size remains the default 4.
95 CodePointerSize = (is64Bit && !isX32) ? 8 : 4;
97 // OTOH, stack slot size is always 8 for x86-64, even with the x32 ABI.
98 CalleeSaveStackSlotSize = is64Bit ? 8 : 4;
100 AssemblerDialect = AsmWriterFlavor;
102 TextAlignFillValue = 0x90;
105 SupportsDebugInformation = true;
107 // Exceptions handling
108 ExceptionsType = ExceptionHandling::DwarfCFI;
110 // Always enable the integrated assembler by default.
111 // Clang also enabled it when the OS is Solaris but that is redundant here.
112 UseIntegratedAssembler = true;
116 X86_64MCAsmInfoDarwin::getExprForPersonalitySymbol(const MCSymbol *Sym,
118 MCStreamer &Streamer) const {
119 MCContext &Context = Streamer.getContext();
121 MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_GOTPCREL, Context);
122 const MCExpr *Four = MCConstantExpr::create(4, Context);
123 return MCBinaryExpr::createAdd(Res, Four, Context);
126 void X86MCAsmInfoMicrosoft::anchor() { }
128 X86MCAsmInfoMicrosoft::X86MCAsmInfoMicrosoft(const Triple &Triple) {
129 if (Triple.getArch() == Triple::x86_64) {
130 PrivateGlobalPrefix = ".L";
131 PrivateLabelPrefix = ".L";
133 WinEHEncodingType = WinEH::EncodingType::Itanium;
135 // 32-bit X86 doesn't use CFI, so this isn't a real encoding type. It's just
136 // a place holder that the Windows EHStreamer looks for to suppress CFI
137 // output. In particular, usesWindowsCFI() returns false.
138 WinEHEncodingType = WinEH::EncodingType::X86;
141 ExceptionsType = ExceptionHandling::WinEH;
143 AssemblerDialect = AsmWriterFlavor;
145 TextAlignFillValue = 0x90;
147 AllowAtInName = true;
149 UseIntegratedAssembler = true;
152 void X86MCAsmInfoGNUCOFF::anchor() { }
154 X86MCAsmInfoGNUCOFF::X86MCAsmInfoGNUCOFF(const Triple &Triple) {
155 assert(Triple.isOSWindows() && "Windows is the only supported COFF target");
156 if (Triple.getArch() == Triple::x86_64) {
157 PrivateGlobalPrefix = ".L";
158 PrivateLabelPrefix = ".L";
160 WinEHEncodingType = WinEH::EncodingType::Itanium;
161 ExceptionsType = ExceptionHandling::WinEH;
163 ExceptionsType = ExceptionHandling::DwarfCFI;
166 AssemblerDialect = AsmWriterFlavor;
168 TextAlignFillValue = 0x90;
170 UseIntegratedAssembler = true;