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 using namespace llvm;
  24
  25 static const char* x86_asm_table[] = {"{si}", "S",
  26                                       "{di}", "D",
  27                                       "{ax}", "a",
  28                                       "{cx}", "c",
  29                                       "{memory}", "memory",
  30                                       "{flags}", "",
  31                                       "{dirflag}", "",
  32                                       "{fpsr}", "",
  33                                       "{cc}", "cc",
  34                                       0,0};
  35
  36 X86TargetAsmInfo::X86TargetAsmInfo(const X86TargetMachine &TM) {
  37   const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
  38
  39   // FIXME - Should be simplified.
  40
  41   AsmTransCBE = x86_asm_table;
  42
  43   switch (Subtarget->TargetType) {
  44   case X86Subtarget::isDarwin:
  45     AlignmentIsInBytes = false;
  46     GlobalPrefix = "_";
  47     if (!Subtarget->is64Bit())
  48       Data64bitsDirective = 0;       // we can't emit a 64-bit unit
  49     ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
  50     PrivateGlobalPrefix = "L";     // Marker for constant pool idxs
  51     BSSSection = 0;                       // no BSS section.
  52     ZeroFillDirective = "\t.zerofill\t";  // Uses .zerofill
  53     ConstantPoolSection = "\t.const\n";
  54     JumpTableDataSection = "\t.const\n";
  55     CStringSection = "\t.cstring";
  56     FourByteConstantSection = "\t.literal4\n";
  57     EightByteConstantSection = "\t.literal8\n";
  58     if (Subtarget->is64Bit())
  59       SixteenByteConstantSection = "\t.literal16\n";
  60     ReadOnlySection = "\t.const\n";
  61     LCOMMDirective = "\t.lcomm\t";
  62     SwitchToSectionDirective = "\t.section ";
  63     COMMDirectiveTakesAlignment = false;
  64     HasDotTypeDotSizeDirective = false;
  65     if (TM.getRelocationModel() == Reloc::Static) {
  66       StaticCtorsSection = ".constructor";
  67       StaticDtorsSection = ".destructor";
  68     } else {
  69       StaticCtorsSection = ".mod_init_func";
  70       StaticDtorsSection = ".mod_term_func";
  71     }
  72     if (Subtarget->is64Bit()) {
  73       PersonalityPrefix = "";
  74       PersonalitySuffix = "+4@GOTPCREL";
  75     } else {
  76       PersonalityPrefix = "L";
  77       PersonalitySuffix = "$non_lazy_ptr";
  78     }
  79     NeedsIndirectEncoding = true;
  80     InlineAsmStart = "# InlineAsm Start";
  81     InlineAsmEnd = "# InlineAsm End";
  82     SetDirective = "\t.set";
  83     PCSymbol = ".";
  84     UsedDirective = "\t.no_dead_strip\t";
  85     WeakDefDirective = "\t.weak_definition ";
  86     WeakRefDirective = "\t.weak_reference ";
  87     HiddenDirective = "\t.private_extern ";
  88
  89     // In non-PIC modes, emit a special label before jump tables so that the
  90     // linker can perform more accurate dead code stripping.
  91     if (TM.getRelocationModel() != Reloc::PIC_) {
  92       // Emit a local label that is preserved until the linker runs.
  93       JumpTableSpecialLabelPrefix = "l";
  94     }
  95
  96     SupportsDebugInformation = true;
  97     NeedsSet = true;
  98     DwarfAbbrevSection = ".section __DWARF,__debug_abbrev,regular,debug";
  99     DwarfInfoSection = ".section __DWARF,__debug_info,regular,debug";
 100     DwarfLineSection = ".section __DWARF,__debug_line,regular,debug";
 101     DwarfFrameSection = ".section __DWARF,__debug_frame,regular,debug";
 102     DwarfPubNamesSection = ".section __DWARF,__debug_pubnames,regular,debug";
 103     DwarfPubTypesSection = ".section __DWARF,__debug_pubtypes,regular,debug";
 104     DwarfStrSection = ".section __DWARF,__debug_str,regular,debug";
 105     DwarfLocSection = ".section __DWARF,__debug_loc,regular,debug";
 106     DwarfARangesSection = ".section __DWARF,__debug_aranges,regular,debug";
 107     DwarfRangesSection = ".section __DWARF,__debug_ranges,regular,debug";
 108     DwarfMacInfoSection = ".section __DWARF,__debug_macinfo,regular,debug";
 109
 110     // Exceptions handling
 111     SupportsExceptionHandling = true;
 112     GlobalEHDirective = "\t.globl\t";
 113     SupportsWeakOmittedEHFrame = false;
 114     AbsoluteEHSectionOffsets = false;
 115     if (Subtarget->is64Bit())
 116       ShortenEHDataOn64Bit = true;
 117     DwarfEHFrameSection =
 118     ".section __TEXT,__eh_frame,coalesced,no_toc+strip_static_syms+live_support";
 119     DwarfExceptionSection = ".section __DATA,__gcc_except_tab";
 120     break;
 121
 122   case X86Subtarget::isELF:
 123     ReadOnlySection = "\t.section\t.rodata";
 124     FourByteConstantSection = "\t.section\t.rodata.cst4,\"aM\",@progbits,4";
 125     EightByteConstantSection = "\t.section\t.rodata.cst8,\"aM\",@progbits,8";
 126     SixteenByteConstantSection = "\t.section\t.rodata.cst16,\"aM\",@progbits,16";
 127     CStringSection = "\t.section\t.rodata.str1.1,\"aMS\",@progbits,1";
 128     PrivateGlobalPrefix = ".L";
 129     WeakRefDirective = "\t.weak\t";
 130     SetDirective = "\t.set\t";
 131     PCSymbol = ".";
 132
 133     // Set up DWARF directives
 134     HasLEB128 = true;  // Target asm supports leb128 directives (little-endian)
 135
 136     // Debug Information
 137     AbsoluteDebugSectionOffsets = true;
 138     SupportsDebugInformation = true;
 139     DwarfAbbrevSection =  "\t.section\t.debug_abbrev,\"\",@progbits";
 140     DwarfInfoSection =    "\t.section\t.debug_info,\"\",@progbits";
 141     DwarfLineSection =    "\t.section\t.debug_line,\"\",@progbits";
 142     DwarfFrameSection =   "\t.section\t.debug_frame,\"\",@progbits";
 143     DwarfPubNamesSection ="\t.section\t.debug_pubnames,\"\",@progbits";
 144     DwarfPubTypesSection ="\t.section\t.debug_pubtypes,\"\",@progbits";
 145     DwarfStrSection =     "\t.section\t.debug_str,\"\",@progbits";
 146     DwarfLocSection =     "\t.section\t.debug_loc,\"\",@progbits";
 147     DwarfARangesSection = "\t.section\t.debug_aranges,\"\",@progbits";
 148     DwarfRangesSection =  "\t.section\t.debug_ranges,\"\",@progbits";
 149     DwarfMacInfoSection = "\t.section\t.debug_macinfo,\"\",@progbits";
 150
 151     // Exceptions handling
 152     if (!Subtarget->is64Bit())
 153       SupportsExceptionHandling = true;
 154     AbsoluteEHSectionOffsets = false;
 155     DwarfEHFrameSection = "\t.section\t.eh_frame,\"aw\",@progbits";
 156     DwarfExceptionSection = "\t.section\t.gcc_except_table,\"a\",@progbits";
 157     break;
 158
 159   case X86Subtarget::isCygwin:
 160   case X86Subtarget::isMingw:
 161     GlobalPrefix = "_";
 162     LCOMMDirective = "\t.lcomm\t";
 163     COMMDirectiveTakesAlignment = false;
 164     HasDotTypeDotSizeDirective = false;
 165     StaticCtorsSection = "\t.section .ctors,\"aw\"";
 166     StaticDtorsSection = "\t.section .dtors,\"aw\"";
 167     HiddenDirective = NULL;
 168     PrivateGlobalPrefix = "L";  // Prefix for private global symbols
 169     WeakRefDirective = "\t.weak\t";
 170     SetDirective = "\t.set\t";
 171
 172     // Set up DWARF directives
 173     HasLEB128 = true;  // Target asm supports leb128 directives (little-endian)
 174     AbsoluteDebugSectionOffsets = true;
 175     AbsoluteEHSectionOffsets = false;
 176     SupportsDebugInformation = true;
 177     DwarfSectionOffsetDirective = "\t.secrel32\t";
 178     DwarfAbbrevSection =  "\t.section\t.debug_abbrev,\"dr\"";
 179     DwarfInfoSection =    "\t.section\t.debug_info,\"dr\"";
 180     DwarfLineSection =    "\t.section\t.debug_line,\"dr\"";
 181     DwarfFrameSection =   "\t.section\t.debug_frame,\"dr\"";
 182     DwarfPubNamesSection ="\t.section\t.debug_pubnames,\"dr\"";
 183     DwarfPubTypesSection ="\t.section\t.debug_pubtypes,\"dr\"";
 184     DwarfStrSection =     "\t.section\t.debug_str,\"dr\"";
 185     DwarfLocSection =     "\t.section\t.debug_loc,\"dr\"";
 186     DwarfARangesSection = "\t.section\t.debug_aranges,\"dr\"";
 187     DwarfRangesSection =  "\t.section\t.debug_ranges,\"dr\"";
 188     DwarfMacInfoSection = "\t.section\t.debug_macinfo,\"dr\"";
 189     break;
 190
 191   case X86Subtarget::isWindows:
 192     GlobalPrefix = "_";
 193     HasDotTypeDotSizeDirective = false;
 194     break;
 195
 196   default: break;
 197   }
 198
 199   if (Subtarget->isFlavorIntel()) {
 200     GlobalPrefix = "_";
 201     CommentString = ";";
 202
 203     PrivateGlobalPrefix = "$";
 204     AlignDirective = "\talign\t";
 205     ZeroDirective = "\tdb\t";
 206     ZeroDirectiveSuffix = " dup(0)";
 207     AsciiDirective = "\tdb\t";
 208     AscizDirective = 0;
 209     Data8bitsDirective = "\tdb\t";
 210     Data16bitsDirective = "\tdw\t";
 211     Data32bitsDirective = "\tdd\t";
 212     Data64bitsDirective = "\tdq\t";
 213     HasDotTypeDotSizeDirective = false;
 214
 215     TextSection = "_text";
 216     DataSection = "_data";
 217     JumpTableDataSection = NULL;
 218     SwitchToSectionDirective = "";
 219     TextSectionStartSuffix = "\tsegment 'CODE'";
 220     DataSectionStartSuffix = "\tsegment 'DATA'";
 221     SectionEndDirectiveSuffix = "\tends\n";
 222   }
 223
 224   AssemblerDialect = Subtarget->getAsmFlavor();
 225 }
 226
 227 bool X86TargetAsmInfo::LowerToBSwap(CallInst *CI) const {
 228   // FIXME: this should verify that we are targetting a 486 or better.  If not,
 229   // we will turn this bswap into something that will be lowered to logical ops
 230   // instead of emitting the bswap asm.  For now, we don't support 486 or lower
 231   // so don't worry about this.
 232
 233   // Verify this is a simple bswap.
 234   if (CI->getNumOperands() != 2 ||
 235       CI->getType() != CI->getOperand(1)->getType() ||
 236       !CI->getType()->isInteger())
 237     return false;
 238
 239   const IntegerType *Ty = dyn_cast<IntegerType>(CI->getType());
 240   if (!Ty || Ty->getBitWidth() % 16 != 0)
 241     return false;
 242
 243   // Okay, we can do this xform, do so now.
 244   const Type *Tys[] = { Ty };
 245   Module *M = CI->getParent()->getParent()->getParent();
 246   Constant *Int = Intrinsic::getDeclaration(M, Intrinsic::bswap, Tys, 1);
 247
 248   Value *Op = CI->getOperand(1);
 249   Op = new CallInst(Int, Op, CI->getName(), CI);
 250
 251   CI->replaceAllUsesWith(Op);
 252   CI->eraseFromParent();
 253   return true;
 254 }
 255
 256
 257 bool X86TargetAsmInfo::ExpandInlineAsm(CallInst *CI) const {
 258   InlineAsm *IA = cast<InlineAsm>(CI->getCalledValue());
 259   std::vector<InlineAsm::ConstraintInfo> Constraints = IA->ParseConstraints();
 260
 261   std::string AsmStr = IA->getAsmString();
 262
 263   // TODO: should remove alternatives from the asmstring: "foo {a|b}" -> "foo a"
 264   std::vector<std::string> AsmPieces;
 265   SplitString(AsmStr, AsmPieces, "\n");  // ; as separator?
 266
 267   switch (AsmPieces.size()) {
 268   default: return false;
 269   case 1:
 270     AsmStr = AsmPieces[0];
 271     AsmPieces.clear();
 272     SplitString(AsmStr, AsmPieces, " \t");  // Split with whitespace.
 273
 274     // bswap $0
 275     if (AsmPieces.size() == 2 &&
 276         AsmPieces[0] == "bswap" && AsmPieces[1] == "$0") {
 277       // No need to check constraints, nothing other than the equivalent of
 278       // "=r,0" would be valid here.
 279       return LowerToBSwap(CI);
 280     }
 281     break;
 282   case 3:
 283     if (CI->getType() == Type::Int64Ty && Constraints.size() >= 2 &&
 284         Constraints[0].Codes.size() == 1 && Constraints[0].Codes[0] == "A" &&
 285         Constraints[1].Codes.size() == 1 && Constraints[1].Codes[0] == "0") {
 286       // bswap %eax / bswap %edx / xchgl %eax, %edx  -> llvm.bswap.i64
 287       std::vector<std::string> Words;
 288       SplitString(AsmPieces[0], Words, " \t");
 289       if (Words.size() == 2 && Words[0] == "bswap" && Words[1] == "%eax") {
 290         Words.clear();
 291         SplitString(AsmPieces[1], Words, " \t");
 292         if (Words.size() == 2 && Words[0] == "bswap" && Words[1] == "%edx") {
 293           Words.clear();
 294           SplitString(AsmPieces[2], Words, " \t,");
 295           if (Words.size() == 3 && Words[0] == "xchgl" && Words[1] == "%eax" &&
 296               Words[2] == "%edx") {
 297             return LowerToBSwap(CI);
 298           }
 299         }
 300       }
 301     }
 302     break;
 303   }
 304   return false;
 305 }