lib/Target/X86/X86TargetAsmInfo.cpp

   1 //===-- X86TargetAsmInfo.cpp - X86 asm properties ---------------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file was developed by James M. Laskey and is distributed under the
   6 // University of Illinois Open Source 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/Module.h"
  21 #include "llvm/ADT/StringExtras.h"
  22 using namespace llvm;
  23
  24 // ASM variant to use.
  25 enum {
  26   X86_ATT   = 0,
  27   X86_INTEL = 1
  28 };
  29
  30 static const char* x86_asm_table[] = {"{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 X86TargetAsmInfo::X86TargetAsmInfo(const X86TargetMachine &TM) {
  42   const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
  43
  44   // FIXME - Should be simplified.
  45
  46   AsmTransCBE = x86_asm_table;
  47   AssemblerDialect = X86_ATT;
  48
  49   switch (Subtarget->TargetType) {
  50   case X86Subtarget::isDarwin:
  51     AlignmentIsInBytes = false;
  52     GlobalPrefix = "_";
  53     if (!Subtarget->is64Bit())
  54       Data64bitsDirective = 0;       // we can't emit a 64-bit unit
  55     ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
  56     PrivateGlobalPrefix = "L";     // Marker for constant pool idxs
  57     ConstantPoolSection = "\t.const\n";
  58     JumpTableDataSection = "\t.const\n";
  59     CStringSection = "\t.cstring";
  60     FourByteConstantSection = "\t.literal4\n";
  61     EightByteConstantSection = "\t.literal8\n";
  62     if (Subtarget->is64Bit())
  63       SixteenByteConstantSection = "\t.literal16\n";
  64     LCOMMDirective = "\t.lcomm\t";
  65     COMMDirectiveTakesAlignment = false;
  66     HasDotTypeDotSizeDirective = false;
  67     StaticCtorsSection = ".mod_init_func";
  68     StaticDtorsSection = ".mod_term_func";
  69     InlineAsmStart = "# InlineAsm Start";
  70     InlineAsmEnd = "# InlineAsm End";
  71     SetDirective = "\t.set";
  72     UsedDirective = "\t.no_dead_strip\t";
  73     WeakRefDirective = "\t.weak_reference\t";
  74     HiddenDirective = "\t.private_extern\t";
  75
  76     NeedsSet = true;
  77     DwarfAbbrevSection = ".section __DWARF,__debug_abbrev,regular,debug";
  78     DwarfInfoSection = ".section __DWARF,__debug_info,regular,debug";
  79     DwarfLineSection = ".section __DWARF,__debug_line,regular,debug";
  80     DwarfFrameSection = ".section __DWARF,__debug_frame,regular,debug";
  81     DwarfPubNamesSection = ".section __DWARF,__debug_pubnames,regular,debug";
  82     DwarfPubTypesSection = ".section __DWARF,__debug_pubtypes,regular,debug";
  83     DwarfStrSection = ".section __DWARF,__debug_str,regular,debug";
  84     DwarfLocSection = ".section __DWARF,__debug_loc,regular,debug";
  85     DwarfARangesSection = ".section __DWARF,__debug_aranges,regular,debug";
  86     DwarfRangesSection = ".section __DWARF,__debug_ranges,regular,debug";
  87     DwarfMacInfoSection = ".section __DWARF,__debug_macinfo,regular,debug";
  88     break;
  89
  90   case X86Subtarget::isELF:
  91     // Set up DWARF directives
  92     HasLEB128 = true;  // Target asm supports leb128 directives (little-endian)
  93     // bool HasLEB128; // Defaults to false.
  94     // hasDotLoc - True if target asm supports .loc directives.
  95     // bool HasDotLoc; // Defaults to false.
  96     // HasDotFile - True if target asm supports .file directives.
  97     // bool HasDotFile; // Defaults to false.
  98     PrivateGlobalPrefix = ".L";
  99     WeakRefDirective = "\t.weak\t";
 100     DwarfRequiresFrameSection = false;
 101     DwarfAbbrevSection =  "\t.section\t.debug_abbrev,\"\",@progbits";
 102     DwarfInfoSection =    "\t.section\t.debug_info,\"\",@progbits";
 103     DwarfLineSection =    "\t.section\t.debug_line,\"\",@progbits";
 104     DwarfFrameSection =   "\t.section\t.debug_frame,\"\",@progbits";
 105     DwarfPubNamesSection ="\t.section\t.debug_pubnames,\"\",@progbits";
 106     DwarfPubTypesSection ="\t.section\t.debug_pubtypes,\"\",@progbits";
 107     DwarfStrSection =     "\t.section\t.debug_str,\"\",@progbits";
 108     DwarfLocSection =     "\t.section\t.debug_loc,\"\",@progbits";
 109     DwarfARangesSection = "\t.section\t.debug_aranges,\"\",@progbits";
 110     DwarfRangesSection =  "\t.section\t.debug_ranges,\"\",@progbits";
 111     DwarfMacInfoSection = "\t.section\t.debug_macinfo,\"\",@progbits";
 112     break;
 113
 114   case X86Subtarget::isCygwin:
 115   case X86Subtarget::isMingw:
 116     GlobalPrefix = "_";
 117     LCOMMDirective = "\t.lcomm\t";
 118     COMMDirectiveTakesAlignment = false;
 119     HasDotTypeDotSizeDirective = false;
 120     StaticCtorsSection = "\t.section .ctors,\"aw\"";
 121     StaticDtorsSection = "\t.section .dtors,\"aw\"";
 122     HiddenDirective = NULL;
 123
 124     // Set up DWARF directives
 125     HasLEB128 = true;  // Target asm supports leb128 directives (little-endian)
 126     PrivateGlobalPrefix = "L";  // Prefix for private global symbols
 127     DwarfRequiresFrameSection = false;
 128     DwarfAbbrevSection =  "\t.section\t.debug_abbrev,\"dr\"";
 129     DwarfInfoSection =    "\t.section\t.debug_info,\"dr\"";
 130     DwarfLineSection =    "\t.section\t.debug_line,\"dr\"";
 131     DwarfFrameSection =   "\t.section\t.debug_frame,\"dr\"";
 132     DwarfPubNamesSection ="\t.section\t.debug_pubnames,\"dr\"";
 133     DwarfPubTypesSection ="\t.section\t.debug_pubtypes,\"dr\"";
 134     DwarfStrSection =     "\t.section\t.debug_str,\"dr\"";
 135     DwarfLocSection =     "\t.section\t.debug_loc,\"dr\"";
 136     DwarfARangesSection = "\t.section\t.debug_aranges,\"dr\"";
 137     DwarfRangesSection =  "\t.section\t.debug_ranges,\"dr\"";
 138     DwarfMacInfoSection = "\t.section\t.debug_macinfo,\"dr\"";
 139     break;
 140
 141     break;
 142   case X86Subtarget::isWindows:
 143     GlobalPrefix = "_";
 144     HasDotTypeDotSizeDirective = false;
 145     break;
 146   default: break;
 147   }
 148
 149   if (Subtarget->isFlavorIntel()) {
 150     GlobalPrefix = "_";
 151     CommentString = ";";
 152
 153     PrivateGlobalPrefix = "$";
 154     AlignDirective = "\talign\t";
 155     ZeroDirective = "\tdb\t";
 156     ZeroDirectiveSuffix = " dup(0)";
 157     AsciiDirective = "\tdb\t";
 158     AscizDirective = 0;
 159     Data8bitsDirective = "\tdb\t";
 160     Data16bitsDirective = "\tdw\t";
 161     Data32bitsDirective = "\tdd\t";
 162     Data64bitsDirective = "\tdq\t";
 163     HasDotTypeDotSizeDirective = false;
 164
 165     TextSection = "_text";
 166     DataSection = "_data";
 167     JumpTableDataSection = NULL;
 168     SwitchToSectionDirective = "";
 169     TextSectionStartSuffix = "\tsegment 'CODE'";
 170     DataSectionStartSuffix = "\tsegment 'DATA'";
 171     SectionEndDirectiveSuffix = "\tends\n";
 172   }
 173 }
 174
 175 bool X86TargetAsmInfo::LowerToBSwap(CallInst *CI) const {
 176   // FIXME: this should verify that we are targetting a 486 or better.  If not,
 177   // we will turn this bswap into something that will be lowered to logical ops
 178   // instead of emitting the bswap asm.  For now, we don't support 486 or lower
 179   // so don't worry about this.
 180
 181   // Verify this is a simple bswap.
 182   if (CI->getNumOperands() != 2 ||
 183       CI->getType() != CI->getOperand(1)->getType() ||
 184       !CI->getType()->isInteger())
 185     return false;
 186
 187   const Type *Ty = CI->getType();
 188   const char *IntName;
 189   if (const IntegerType *ITy = dyn_cast<IntegerType>(Ty)) {
 190     unsigned BitWidth = ITy->getBitWidth();
 191     if (BitWidth == 16)
 192       IntName = "llvm.bswap.i16";
 193     else if (BitWidth == 32)
 194       IntName = "llvm.bswap.i32";
 195     else if (BitWidth == 64)
 196       IntName = "llvm.bswap.i64";
 197     else
 198       return false;
 199   } else
 200     return false;
 201
 202   // Okay, we can do this xform, do so now.
 203   Module *M = CI->getParent()->getParent()->getParent();
 204   Constant *Int = M->getOrInsertFunction(IntName, Ty, Ty, (Type*)0);
 205
 206   Value *Op = CI->getOperand(1);
 207   Op = new CallInst(Int, Op, CI->getName(), CI);
 208
 209   CI->replaceAllUsesWith(Op);
 210   CI->eraseFromParent();
 211   return true;
 212 }
 213
 214
 215 bool X86TargetAsmInfo::ExpandInlineAsm(CallInst *CI) const {
 216   InlineAsm *IA = cast<InlineAsm>(CI->getCalledValue());
 217   std::vector<InlineAsm::ConstraintInfo> Constraints = IA->ParseConstraints();
 218
 219   std::string AsmStr = IA->getAsmString();
 220
 221   // TODO: should remove alternatives from the asmstring: "foo {a|b}" -> "foo a"
 222   std::vector<std::string> AsmPieces;
 223   SplitString(AsmStr, AsmPieces, "\n");  // ; as separator?
 224
 225   switch (AsmPieces.size()) {
 226   default: return false;
 227   case 1:
 228     AsmStr = AsmPieces[0];
 229     AsmPieces.clear();
 230     SplitString(AsmStr, AsmPieces, " \t");  // Split with whitespace.
 231
 232     // bswap $0
 233     if (AsmPieces.size() == 2 &&
 234         AsmPieces[0] == "bswap" && AsmPieces[1] == "$0") {
 235       // No need to check constraints, nothing other than the equivalent of
 236       // "=r,0" would be valid here.
 237       return LowerToBSwap(CI);
 238     }
 239     break;
 240   case 3:
 241     if (CI->getType() == Type::Int64Ty && Constraints.size() >= 2 &&
 242         Constraints[0].Codes.size() == 1 && Constraints[0].Codes[0] == "A" &&
 243         Constraints[1].Codes.size() == 1 && Constraints[1].Codes[0] == "0") {
 244       // bswap %eax / bswap %edx / xchgl %eax, %edx  -> llvm.bswap.i64
 245       std::vector<std::string> Words;
 246       SplitString(AsmPieces[0], Words, " \t");
 247       if (Words.size() == 2 && Words[0] == "bswap" && Words[1] == "%eax") {
 248         Words.clear();
 249         SplitString(AsmPieces[1], Words, " \t");
 250         if (Words.size() == 2 && Words[0] == "bswap" && Words[1] == "%edx") {
 251           Words.clear();
 252           SplitString(AsmPieces[2], Words, " \t,");
 253           if (Words.size() == 3 && Words[0] == "xchgl" && Words[1] == "%eax" &&
 254               Words[2] == "%edx") {
 255             return LowerToBSwap(CI);
 256           }
 257         }
 258       }
 259     }
 260     break;
 261   }
 262   return false;
 263 }