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 static const char* x86_asm_table[] = {"{si}", "S",
  25                                       "{di}", "D",
  26                                       "{ax}", "a",
  27                                       "{cx}", "c",
  28                                       "{memory}", "memory",
  29                                       "{flags}", "",
  30                                       "{dirflag}", "",
  31                                       "{fpsr}", "",
  32                                       "{cc}", "cc",
  33                                       0,0};
  34
  35 X86TargetAsmInfo::X86TargetAsmInfo(const X86TargetMachine &TM) {
  36   const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
  37
  38   // FIXME - Should be simplified.
  39
  40   AsmTransCBE = x86_asm_table;
  41
  42   switch (Subtarget->TargetType) {
  43   case X86Subtarget::isDarwin:
  44     AlignmentIsInBytes = false;
  45     GlobalPrefix = "_";
  46     if (!Subtarget->is64Bit())
  47       Data64bitsDirective = 0;       // we can't emit a 64-bit unit
  48     ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
  49     PrivateGlobalPrefix = "L";     // Marker for constant pool idxs
  50     ConstantPoolSection = "\t.const\n";
  51     JumpTableDataSection = "\t.const\n";
  52     CStringSection = "\t.cstring";
  53     FourByteConstantSection = "\t.literal4\n";
  54     EightByteConstantSection = "\t.literal8\n";
  55     if (Subtarget->is64Bit())
  56       SixteenByteConstantSection = "\t.literal16\n";
  57     LCOMMDirective = "\t.lcomm\t";
  58     COMMDirectiveTakesAlignment = false;
  59     HasDotTypeDotSizeDirective = false;
  60     StaticCtorsSection = ".mod_init_func";
  61     StaticDtorsSection = ".mod_term_func";
  62     InlineAsmStart = "# InlineAsm Start";
  63     InlineAsmEnd = "# InlineAsm End";
  64     SetDirective = "\t.set";
  65     UsedDirective = "\t.no_dead_strip\t";
  66     WeakRefDirective = "\t.weak_reference\t";
  67     HiddenDirective = "\t.private_extern\t";
  68
  69     NeedsSet = true;
  70     DwarfAbbrevSection = ".section __DWARF,__debug_abbrev,regular,debug";
  71     DwarfInfoSection = ".section __DWARF,__debug_info,regular,debug";
  72     DwarfLineSection = ".section __DWARF,__debug_line,regular,debug";
  73     DwarfFrameSection = ".section __DWARF,__debug_frame,regular,debug";
  74     DwarfPubNamesSection = ".section __DWARF,__debug_pubnames,regular,debug";
  75     DwarfPubTypesSection = ".section __DWARF,__debug_pubtypes,regular,debug";
  76     DwarfStrSection = ".section __DWARF,__debug_str,regular,debug";
  77     DwarfLocSection = ".section __DWARF,__debug_loc,regular,debug";
  78     DwarfARangesSection = ".section __DWARF,__debug_aranges,regular,debug";
  79     DwarfRangesSection = ".section __DWARF,__debug_ranges,regular,debug";
  80     DwarfMacInfoSection = ".section __DWARF,__debug_macinfo,regular,debug";
  81     break;
  82
  83   case X86Subtarget::isELF:
  84     // Set up DWARF directives
  85     HasLEB128 = true;  // Target asm supports leb128 directives (little-endian)
  86     // bool HasLEB128; // Defaults to false.
  87     // hasDotLoc - True if target asm supports .loc directives.
  88     // bool HasDotLoc; // Defaults to false.
  89     // HasDotFile - True if target asm supports .file directives.
  90     // bool HasDotFile; // Defaults to false.
  91     PrivateGlobalPrefix = ".L";
  92     WeakRefDirective = "\t.weak\t";
  93     DwarfRequiresFrameSection = false;
  94     DwarfAbbrevSection =  "\t.section\t.debug_abbrev,\"\",@progbits";
  95     DwarfInfoSection =    "\t.section\t.debug_info,\"\",@progbits";
  96     DwarfLineSection =    "\t.section\t.debug_line,\"\",@progbits";
  97     DwarfFrameSection =   "\t.section\t.debug_frame,\"\",@progbits";
  98     DwarfPubNamesSection ="\t.section\t.debug_pubnames,\"\",@progbits";
  99     DwarfPubTypesSection ="\t.section\t.debug_pubtypes,\"\",@progbits";
 100     DwarfStrSection =     "\t.section\t.debug_str,\"\",@progbits";
 101     DwarfLocSection =     "\t.section\t.debug_loc,\"\",@progbits";
 102     DwarfARangesSection = "\t.section\t.debug_aranges,\"\",@progbits";
 103     DwarfRangesSection =  "\t.section\t.debug_ranges,\"\",@progbits";
 104     DwarfMacInfoSection = "\t.section\t.debug_macinfo,\"\",@progbits";
 105     break;
 106
 107   case X86Subtarget::isCygwin:
 108   case X86Subtarget::isMingw:
 109     GlobalPrefix = "_";
 110     LCOMMDirective = "\t.lcomm\t";
 111     COMMDirectiveTakesAlignment = false;
 112     HasDotTypeDotSizeDirective = false;
 113     StaticCtorsSection = "\t.section .ctors,\"aw\"";
 114     StaticDtorsSection = "\t.section .dtors,\"aw\"";
 115     HiddenDirective = NULL;
 116
 117     // Set up DWARF directives
 118     HasLEB128 = true;  // Target asm supports leb128 directives (little-endian)
 119     PrivateGlobalPrefix = "L";  // Prefix for private global symbols
 120     DwarfRequiresFrameSection = false;
 121     DwarfAbbrevSection =  "\t.section\t.debug_abbrev,\"dr\"";
 122     DwarfInfoSection =    "\t.section\t.debug_info,\"dr\"";
 123     DwarfLineSection =    "\t.section\t.debug_line,\"dr\"";
 124     DwarfFrameSection =   "\t.section\t.debug_frame,\"dr\"";
 125     DwarfPubNamesSection ="\t.section\t.debug_pubnames,\"dr\"";
 126     DwarfPubTypesSection ="\t.section\t.debug_pubtypes,\"dr\"";
 127     DwarfStrSection =     "\t.section\t.debug_str,\"dr\"";
 128     DwarfLocSection =     "\t.section\t.debug_loc,\"dr\"";
 129     DwarfARangesSection = "\t.section\t.debug_aranges,\"dr\"";
 130     DwarfRangesSection =  "\t.section\t.debug_ranges,\"dr\"";
 131     DwarfMacInfoSection = "\t.section\t.debug_macinfo,\"dr\"";
 132     break;
 133
 134     break;
 135   case X86Subtarget::isWindows:
 136     GlobalPrefix = "_";
 137     HasDotTypeDotSizeDirective = false;
 138     break;
 139   default: break;
 140   }
 141
 142   if (Subtarget->isFlavorIntel()) {
 143     GlobalPrefix = "_";
 144     CommentString = ";";
 145
 146     PrivateGlobalPrefix = "$";
 147     AlignDirective = "\talign\t";
 148     ZeroDirective = "\tdb\t";
 149     ZeroDirectiveSuffix = " dup(0)";
 150     AsciiDirective = "\tdb\t";
 151     AscizDirective = 0;
 152     Data8bitsDirective = "\tdb\t";
 153     Data16bitsDirective = "\tdw\t";
 154     Data32bitsDirective = "\tdd\t";
 155     Data64bitsDirective = "\tdq\t";
 156     HasDotTypeDotSizeDirective = false;
 157
 158     TextSection = "_text";
 159     DataSection = "_data";
 160     JumpTableDataSection = NULL;
 161     SwitchToSectionDirective = "";
 162     TextSectionStartSuffix = "\tsegment 'CODE'";
 163     DataSectionStartSuffix = "\tsegment 'DATA'";
 164     SectionEndDirectiveSuffix = "\tends\n";
 165   }
 166 }
 167
 168 bool X86TargetAsmInfo::LowerToBSwap(CallInst *CI) const {
 169   // FIXME: this should verify that we are targetting a 486 or better.  If not,
 170   // we will turn this bswap into something that will be lowered to logical ops
 171   // instead of emitting the bswap asm.  For now, we don't support 486 or lower
 172   // so don't worry about this.
 173
 174   // Verify this is a simple bswap.
 175   if (CI->getNumOperands() != 2 ||
 176       CI->getType() != CI->getOperand(1)->getType() ||
 177       !CI->getType()->isInteger())
 178     return false;
 179
 180   const Type *Ty = CI->getType();
 181   const char *IntName;
 182   if (const IntegerType *ITy = dyn_cast<IntegerType>(Ty)) {
 183     unsigned BitWidth = ITy->getBitWidth();
 184     if (BitWidth == 16)
 185       IntName = "llvm.bswap.i16";
 186     else if (BitWidth == 32)
 187       IntName = "llvm.bswap.i32";
 188     else if (BitWidth == 64)
 189       IntName = "llvm.bswap.i64";
 190     else
 191       return false;
 192   } else
 193     return false;
 194
 195   // Okay, we can do this xform, do so now.
 196   Module *M = CI->getParent()->getParent()->getParent();
 197   Constant *Int = M->getOrInsertFunction(IntName, Ty, Ty, (Type*)0);
 198
 199   Value *Op = CI->getOperand(1);
 200   Op = new CallInst(Int, Op, CI->getName(), CI);
 201
 202   CI->replaceAllUsesWith(Op);
 203   CI->eraseFromParent();
 204   return true;
 205 }
 206
 207
 208 bool X86TargetAsmInfo::ExpandInlineAsm(CallInst *CI) const {
 209   InlineAsm *IA = cast<InlineAsm>(CI->getCalledValue());
 210   std::vector<InlineAsm::ConstraintInfo> Constraints = IA->ParseConstraints();
 211
 212   std::string AsmStr = IA->getAsmString();
 213
 214   // TODO: should remove alternatives from the asmstring: "foo {a|b}" -> "foo a"
 215   std::vector<std::string> AsmPieces;
 216   SplitString(AsmStr, AsmPieces, "\n");  // ; as separator?
 217
 218   switch (AsmPieces.size()) {
 219   default: return false;
 220   case 1:
 221     AsmStr = AsmPieces[0];
 222     AsmPieces.clear();
 223     SplitString(AsmStr, AsmPieces, " \t");  // Split with whitespace.
 224
 225     // bswap $0
 226     if (AsmPieces.size() == 2 &&
 227         AsmPieces[0] == "bswap" && AsmPieces[1] == "$0") {
 228       // No need to check constraints, nothing other than the equivalent of
 229       // "=r,0" would be valid here.
 230       return LowerToBSwap(CI);
 231     }
 232     break;
 233   case 3:
 234     if (CI->getType() == Type::Int64Ty && Constraints.size() >= 2 &&
 235         Constraints[0].Codes.size() == 1 && Constraints[0].Codes[0] == "A" &&
 236         Constraints[1].Codes.size() == 1 && Constraints[1].Codes[0] == "0") {
 237       // bswap %eax / bswap %edx / xchgl %eax, %edx  -> llvm.bswap.i64
 238       std::vector<std::string> Words;
 239       SplitString(AsmPieces[0], Words, " \t");
 240       if (Words.size() == 2 && Words[0] == "bswap" && Words[1] == "%eax") {
 241         Words.clear();
 242         SplitString(AsmPieces[1], Words, " \t");
 243         if (Words.size() == 2 && Words[0] == "bswap" && Words[1] == "%edx") {
 244           Words.clear();
 245           SplitString(AsmPieces[2], Words, " \t,");
 246           if (Words.size() == 3 && Words[0] == "xchgl" && Words[1] == "%eax" &&
 247               Words[2] == "%edx") {
 248             return LowerToBSwap(CI);
 249           }
 250         }
 251       }
 252     }
 253     break;
 254   }
 255   return false;
 256 }