lib/Target/X86/X86TargetAsmInfo.cpp

   1 //===-- X86TargetAsmInfo.cpp - X86 asm properties ---------------*- C++ -*-===//
   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 X86TargetAsmInfo properties.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "X86TargetAsmInfo.h"
  15 #include "X86TargetMachine.h"
  16 #include "X86Subtarget.h"
  17 #include "llvm/DerivedTypes.h"
  18 #include "llvm/InlineAsm.h"
  19 #include "llvm/Instructions.h"
  20 #include "llvm/Intrinsics.h"
  21 #include "llvm/Module.h"
  22 #include "llvm/ADT/StringExtras.h"
  23 #include "llvm/Support/Dwarf.h"
  24 #include "llvm/Support/ErrorHandling.h"
  25
  26 using namespace llvm;
  27 using namespace llvm::dwarf;
  28
  29 const char *const llvm::x86_asm_table[] = {
  30   "{si}", "S",
  31   "{di}", "D",
  32   "{ax}", "a",
  33   "{cx}", "c",
  34   "{memory}", "memory",
  35   "{flags}", "",
  36   "{dirflag}", "",
  37   "{fpsr}", "",
  38   "{cc}", "cc",
  39   0,0};
  40
  41 X86DarwinTargetAsmInfo::X86DarwinTargetAsmInfo(const X86TargetMachine &TM):
  42   X86TargetAsmInfo<DarwinTargetAsmInfo>(TM) {
  43   const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
  44   bool is64Bit = Subtarget->is64Bit();
  45
  46   AlignmentIsInBytes = false;
  47   TextAlignFillValue = 0x90;
  48
  49
  50   if (!is64Bit)
  51     Data64bitsDirective = 0;       // we can't emit a 64-bit unit
  52   ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
  53   ZeroFillDirective = "\t.zerofill\t";  // Uses .zerofill
  54   if (TM.getRelocationModel() != Reloc::Static)
  55     ConstantPoolSection = "\t.const_data";
  56   else
  57     ConstantPoolSection = "\t.const\n";
  58   // FIXME: Why don't we always use this section?
  59   if (is64Bit)
  60     SixteenByteConstantSection = getUnnamedSection("\t.literal16\n",
  61                                                    SectionFlags::Mergeable);
  62   LCOMMDirective = "\t.lcomm\t";
  63
  64   // Leopard and above support aligned common symbols.
  65   COMMDirectiveTakesAlignment = (Subtarget->getDarwinVers() >= 9);
  66   HasDotTypeDotSizeDirective = false;
  67
  68   if (is64Bit) {
  69     PersonalityPrefix = "";
  70     PersonalitySuffix = "+4@GOTPCREL";
  71   } else {
  72     PersonalityPrefix = "L";
  73     PersonalitySuffix = "$non_lazy_ptr";
  74   }
  75
  76   InlineAsmStart = "## InlineAsm Start";
  77   InlineAsmEnd = "## InlineAsm End";
  78   CommentString = "##";
  79   SetDirective = "\t.set";
  80   PCSymbol = ".";
  81   UsedDirective = "\t.no_dead_strip\t";
  82   ProtectedDirective = "\t.globl\t";
  83
  84   SupportsDebugInformation = true;
  85   DwarfDebugInlineSection = ".section __DWARF,__debug_inlined,regular,debug";
  86   DwarfUsesInlineInfoSection = true;
  87
  88   // Exceptions handling
  89   SupportsExceptionHandling = true;
  90   GlobalEHDirective = "\t.globl\t";
  91   SupportsWeakOmittedEHFrame = false;
  92   AbsoluteEHSectionOffsets = false;
  93   DwarfEHFrameSection =
  94   ".section __TEXT,__eh_frame,coalesced,no_toc+strip_static_syms+live_support";
  95   DwarfExceptionSection = ".section __DATA,__gcc_except_tab";
  96 }
  97
  98 unsigned
  99 X86DarwinTargetAsmInfo::PreferredEHDataFormat(DwarfEncoding::Target Reason,
 100                                               bool Global) const {
 101   if (Reason == DwarfEncoding::Functions && Global)
 102     return (DW_EH_PE_pcrel | DW_EH_PE_indirect | DW_EH_PE_sdata4);
 103   else if (Reason == DwarfEncoding::CodeLabels || !Global)
 104     return DW_EH_PE_pcrel;
 105   else
 106     return DW_EH_PE_absptr;
 107 }
 108
 109 const char *
 110 X86DarwinTargetAsmInfo::getEHGlobalPrefix() const
 111 {
 112   const X86Subtarget* Subtarget = &TM.getSubtarget<X86Subtarget>();
 113   if (Subtarget->getDarwinVers() > 9)
 114     return PrivateGlobalPrefix;
 115   else
 116     return "";
 117 }
 118
 119 X86ELFTargetAsmInfo::X86ELFTargetAsmInfo(const X86TargetMachine &TM):
 120   X86TargetAsmInfo<ELFTargetAsmInfo>(TM) {
 121
 122   CStringSection = ".rodata.str";
 123   PrivateGlobalPrefix = ".L";
 124   WeakRefDirective = "\t.weak\t";
 125   SetDirective = "\t.set\t";
 126   PCSymbol = ".";
 127
 128   // Set up DWARF directives
 129   HasLEB128 = true;  // Target asm supports leb128 directives (little-endian)
 130
 131   // Debug Information
 132   AbsoluteDebugSectionOffsets = true;
 133   SupportsDebugInformation = true;
 134   DwarfAbbrevSection =  "\t.section\t.debug_abbrev,\"\",@progbits";
 135   DwarfInfoSection =    "\t.section\t.debug_info,\"\",@progbits";
 136   DwarfLineSection =    "\t.section\t.debug_line,\"\",@progbits";
 137   DwarfFrameSection =   "\t.section\t.debug_frame,\"\",@progbits";
 138   DwarfPubNamesSection ="\t.section\t.debug_pubnames,\"\",@progbits";
 139   DwarfPubTypesSection ="\t.section\t.debug_pubtypes,\"\",@progbits";
 140   DwarfStrSection =     "\t.section\t.debug_str,\"\",@progbits";
 141   DwarfLocSection =     "\t.section\t.debug_loc,\"\",@progbits";
 142   DwarfARangesSection = "\t.section\t.debug_aranges,\"\",@progbits";
 143   DwarfRangesSection =  "\t.section\t.debug_ranges,\"\",@progbits";
 144   DwarfMacroInfoSection = "\t.section\t.debug_macinfo,\"\",@progbits";
 145
 146   // Exceptions handling
 147   SupportsExceptionHandling = true;
 148   AbsoluteEHSectionOffsets = false;
 149   DwarfEHFrameSection = "\t.section\t.eh_frame,\"aw\",@progbits";
 150   DwarfExceptionSection = "\t.section\t.gcc_except_table,\"a\",@progbits";
 151
 152   // On Linux we must declare when we can use a non-executable stack.
 153   if (TM.getSubtarget<X86Subtarget>().isLinux())
 154     NonexecutableStackDirective = "\t.section\t.note.GNU-stack,\"\",@progbits";
 155 }
 156
 157 unsigned
 158 X86ELFTargetAsmInfo::PreferredEHDataFormat(DwarfEncoding::Target Reason,
 159                                            bool Global) const {
 160   CodeModel::Model CM = TM.getCodeModel();
 161   bool is64Bit = TM.getSubtarget<X86Subtarget>().is64Bit();
 162
 163   if (TM.getRelocationModel() == Reloc::PIC_) {
 164     unsigned Format = 0;
 165
 166     if (!is64Bit)
 167       // 32 bit targets always encode pointers as 4 bytes
 168       Format = DW_EH_PE_sdata4;
 169     else {
 170       // 64 bit targets encode pointers in 4 bytes iff:
 171       // - code model is small OR
 172       // - code model is medium and we're emitting externally visible symbols
 173       //   or any code symbols
 174       if (CM == CodeModel::Small ||
 175           (CM == CodeModel::Medium && (Global ||
 176                                        Reason != DwarfEncoding::Data)))
 177         Format = DW_EH_PE_sdata4;
 178       else
 179         Format = DW_EH_PE_sdata8;
 180     }
 181
 182     if (Global)
 183       Format |= DW_EH_PE_indirect;
 184
 185     return (Format | DW_EH_PE_pcrel);
 186   } else {
 187     if (is64Bit &&
 188         (CM == CodeModel::Small ||
 189          (CM == CodeModel::Medium && Reason != DwarfEncoding::Data)))
 190       return DW_EH_PE_udata4;
 191     else
 192       return DW_EH_PE_absptr;
 193   }
 194 }
 195
 196 X86COFFTargetAsmInfo::X86COFFTargetAsmInfo(const X86TargetMachine &TM):
 197   X86GenericTargetAsmInfo(TM) {
 198
 199   GlobalPrefix = "_";
 200   LCOMMDirective = "\t.lcomm\t";
 201   COMMDirectiveTakesAlignment = false;
 202   HasDotTypeDotSizeDirective = false;
 203   HasSingleParameterDotFile = false;
 204   StaticCtorsSection = "\t.section .ctors,\"aw\"";
 205   StaticDtorsSection = "\t.section .dtors,\"aw\"";
 206   HiddenDirective = NULL;
 207   PrivateGlobalPrefix = "L";  // Prefix for private global symbols
 208   WeakRefDirective = "\t.weak\t";
 209   SetDirective = "\t.set\t";
 210
 211   // Set up DWARF directives
 212   HasLEB128 = true;  // Target asm supports leb128 directives (little-endian)
 213   AbsoluteDebugSectionOffsets = true;
 214   AbsoluteEHSectionOffsets = false;
 215   SupportsDebugInformation = true;
 216   DwarfSectionOffsetDirective = "\t.secrel32\t";
 217   DwarfAbbrevSection =  "\t.section\t.debug_abbrev,\"dr\"";
 218   DwarfInfoSection =    "\t.section\t.debug_info,\"dr\"";
 219   DwarfLineSection =    "\t.section\t.debug_line,\"dr\"";
 220   DwarfFrameSection =   "\t.section\t.debug_frame,\"dr\"";
 221   DwarfPubNamesSection ="\t.section\t.debug_pubnames,\"dr\"";
 222   DwarfPubTypesSection ="\t.section\t.debug_pubtypes,\"dr\"";
 223   DwarfStrSection =     "\t.section\t.debug_str,\"dr\"";
 224   DwarfLocSection =     "\t.section\t.debug_loc,\"dr\"";
 225   DwarfARangesSection = "\t.section\t.debug_aranges,\"dr\"";
 226   DwarfRangesSection =  "\t.section\t.debug_ranges,\"dr\"";
 227   DwarfMacroInfoSection = "\t.section\t.debug_macinfo,\"dr\"";
 228 }
 229
 230 unsigned
 231 X86COFFTargetAsmInfo::PreferredEHDataFormat(DwarfEncoding::Target Reason,
 232                                             bool Global) const {
 233   CodeModel::Model CM = TM.getCodeModel();
 234   bool is64Bit = TM.getSubtarget<X86Subtarget>().is64Bit();
 235
 236   if (TM.getRelocationModel() == Reloc::PIC_) {
 237     unsigned Format = 0;
 238
 239     if (!is64Bit)
 240       // 32 bit targets always encode pointers as 4 bytes
 241       Format = DW_EH_PE_sdata4;
 242     else {
 243       // 64 bit targets encode pointers in 4 bytes iff:
 244       // - code model is small OR
 245       // - code model is medium and we're emitting externally visible symbols
 246       //   or any code symbols
 247       if (CM == CodeModel::Small ||
 248           (CM == CodeModel::Medium && (Global ||
 249                                        Reason != DwarfEncoding::Data)))
 250         Format = DW_EH_PE_sdata4;
 251       else
 252         Format = DW_EH_PE_sdata8;
 253     }
 254
 255     if (Global)
 256       Format |= DW_EH_PE_indirect;
 257
 258     return (Format | DW_EH_PE_pcrel);
 259   }
 260
 261   if (is64Bit &&
 262       (CM == CodeModel::Small ||
 263        (CM == CodeModel::Medium && Reason != DwarfEncoding::Data)))
 264     return DW_EH_PE_udata4;
 265   return DW_EH_PE_absptr;
 266 }
 267
 268 const char *X86COFFTargetAsmInfo::
 269 getSectionPrefixForUniqueGlobal(SectionKind::Kind Kind) const {
 270   switch (Kind) {
 271   default: llvm_unreachable("Unknown section kind");
 272   case SectionKind::Text:             return ".text$linkonce";
 273   case SectionKind::Data:
 274   case SectionKind::DataRelLocal:
 275   case SectionKind::DataRel:
 276   case SectionKind::BSS:
 277   case SectionKind::ThreadData:
 278   case SectionKind::ThreadBSS:        return ".data$linkonce";
 279   case SectionKind::ROData:
 280   case SectionKind::DataRelRO:
 281   case SectionKind::DataRelROLocal:
 282   case SectionKind::RODataMergeConst:
 283   case SectionKind::RODataMergeStr:   return ".rdata$linkonce";
 284   }
 285 }
 286
 287 std::string X86COFFTargetAsmInfo::printSectionFlags(unsigned flags) const {
 288   std::string Flags = ",\"";
 289
 290   if (flags & SectionFlags::Code)
 291     Flags += 'x';
 292   if (flags & SectionFlags::Writable)
 293     Flags += 'w';
 294
 295   Flags += "\"";
 296
 297   return Flags;
 298 }
 299
 300 X86WinTargetAsmInfo::X86WinTargetAsmInfo(const X86TargetMachine &TM):
 301   X86GenericTargetAsmInfo(TM) {
 302   GlobalPrefix = "_";
 303   CommentString = ";";
 304
 305   InlineAsmStart = "; InlineAsm Start";
 306   InlineAsmEnd   = "; InlineAsm End";
 307
 308   PrivateGlobalPrefix = "$";
 309   AlignDirective = "\tALIGN\t";
 310   ZeroDirective = "\tdb\t";
 311   ZeroDirectiveSuffix = " dup(0)";
 312   AsciiDirective = "\tdb\t";
 313   AscizDirective = 0;
 314   Data8bitsDirective = "\tdb\t";
 315   Data16bitsDirective = "\tdw\t";
 316   Data32bitsDirective = "\tdd\t";
 317   Data64bitsDirective = "\tdq\t";
 318   HasDotTypeDotSizeDirective = false;
 319   HasSingleParameterDotFile = false;
 320
 321   AlignmentIsInBytes = true;
 322
 323   TextSection = getUnnamedSection("_text", SectionFlags::Code);
 324   DataSection = getUnnamedSection("_data", SectionFlags::Writable);
 325
 326   JumpTableDataSection = NULL;
 327   SwitchToSectionDirective = "";
 328   TextSectionStartSuffix = "\tSEGMENT PARA 'CODE'";
 329   DataSectionStartSuffix = "\tSEGMENT PARA 'DATA'";
 330   SectionEndDirectiveSuffix = "\tends\n";
 331 }
 332
 333 // Instantiate default implementation.
 334 TEMPLATE_INSTANTIATION(class X86TargetAsmInfo<TargetAsmInfo>);