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/InlineAsm.h"
  18 #include "llvm/Instructions.h"
  19 #include "llvm/Module.h"
  20 #include "llvm/ADT/StringExtras.h"
  21 using namespace llvm;
  22
  23 static const char* x86_asm_table[] = {"{si}", "S",
  24                                       "{di}", "D",
  25                                       "{ax}", "a",
  26                                       "{cx}", "c",
  27                                       "{memory}", "memory",
  28                                       "{flags}", "",
  29                                       "{dirflag}", "",
  30                                       "{fpsr}", "",
  31                                       "{cc}", "cc",
  32                                       0,0};
  33
  34 X86TargetAsmInfo::X86TargetAsmInfo(const X86TargetMachine &TM) {
  35   const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
  36
  37   // FIXME - Should be simplified.
  38
  39   AsmTransCBE = x86_asm_table;
  40
  41   switch (Subtarget->TargetType) {
  42   case X86Subtarget::isDarwin:
  43     AlignmentIsInBytes = false;
  44     GlobalPrefix = "_";
  45     if (!Subtarget->is64Bit())
  46       Data64bitsDirective = 0;       // we can't emit a 64-bit unit
  47     ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
  48     PrivateGlobalPrefix = "L";     // Marker for constant pool idxs
  49     ConstantPoolSection = "\t.const\n";
  50     JumpTableDataSection = "\t.const\n";
  51     CStringSection = "\t.cstring";
  52     FourByteConstantSection = "\t.literal4\n";
  53     EightByteConstantSection = "\t.literal8\n";
  54     if (Subtarget->is64Bit())
  55       SixteenByteConstantSection = "\t.literal16\n";
  56     LCOMMDirective = "\t.lcomm\t";
  57     COMMDirectiveTakesAlignment = false;
  58     HasDotTypeDotSizeDirective = false;
  59     StaticCtorsSection = ".mod_init_func";
  60     StaticDtorsSection = ".mod_term_func";
  61     InlineAsmStart = "# InlineAsm Start";
  62     InlineAsmEnd = "# InlineAsm End";
  63     SetDirective = "\t.set";
  64     UsedDirective = "\t.no_dead_strip\t";
  65     WeakRefDirective = "\t.weak_reference\t";
  66
  67     NeedsSet = true;
  68     DwarfAbbrevSection = ".section __DWARF,__debug_abbrev,regular,debug";
  69     DwarfInfoSection = ".section __DWARF,__debug_info,regular,debug";
  70     DwarfLineSection = ".section __DWARF,__debug_line,regular,debug";
  71     DwarfFrameSection = ".section __DWARF,__debug_frame,regular,debug";
  72     DwarfPubNamesSection = ".section __DWARF,__debug_pubnames,regular,debug";
  73     DwarfPubTypesSection = ".section __DWARF,__debug_pubtypes,regular,debug";
  74     DwarfStrSection = ".section __DWARF,__debug_str,regular,debug";
  75     DwarfLocSection = ".section __DWARF,__debug_loc,regular,debug";
  76     DwarfARangesSection = ".section __DWARF,__debug_aranges,regular,debug";
  77     DwarfRangesSection = ".section __DWARF,__debug_ranges,regular,debug";
  78     DwarfMacInfoSection = ".section __DWARF,__debug_macinfo,regular,debug";
  79     break;
  80
  81   case X86Subtarget::isELF:
  82     // Set up DWARF directives
  83     HasLEB128 = true;  // Target asm supports leb128 directives (little-endian)
  84     // bool HasLEB128; // Defaults to false.
  85     // hasDotLoc - True if target asm supports .loc directives.
  86     // bool HasDotLoc; // Defaults to false.
  87     // HasDotFile - True if target asm supports .file directives.
  88     // bool HasDotFile; // Defaults to false.
  89     PrivateGlobalPrefix = ".";  // Prefix for private global symbols
  90     WeakRefDirective = "\t.weak\t";
  91     DwarfRequiresFrameSection = false;
  92     DwarfAbbrevSection =  "\t.section\t.debug_abbrev,\"\",@progbits";
  93     DwarfInfoSection =    "\t.section\t.debug_info,\"\",@progbits";
  94     DwarfLineSection =    "\t.section\t.debug_line,\"\",@progbits";
  95     DwarfFrameSection =   "\t.section\t.debug_frame,\"\",@progbits";
  96     DwarfPubNamesSection ="\t.section\t.debug_pubnames,\"\",@progbits";
  97     DwarfPubTypesSection ="\t.section\t.debug_pubtypes,\"\",@progbits";
  98     DwarfStrSection =     "\t.section\t.debug_str,\"\",@progbits";
  99     DwarfLocSection =     "\t.section\t.debug_loc,\"\",@progbits";
 100     DwarfARangesSection = "\t.section\t.debug_aranges,\"\",@progbits";
 101     DwarfRangesSection =  "\t.section\t.debug_ranges,\"\",@progbits";
 102     DwarfMacInfoSection = "\t.section\t.debug_macinfo,\"\",@progbits";
 103     break;
 104
 105   case X86Subtarget::isCygwin:
 106     GlobalPrefix = "_";
 107     COMMDirectiveTakesAlignment = false;
 108     HasDotTypeDotSizeDirective = false;
 109     StaticCtorsSection = "\t.section .ctors,\"aw\"";
 110     StaticDtorsSection = "\t.section .dtors,\"aw\"";
 111
 112     // Set up DWARF directives
 113     HasLEB128 = true;  // Target asm supports leb128 directives (little-endian)
 114     PrivateGlobalPrefix = "L";  // Prefix for private global symbols
 115     DwarfRequiresFrameSection = false;
 116     DwarfAbbrevSection =  "\t.section\t.debug_abbrev,\"dr\"";
 117     DwarfInfoSection =    "\t.section\t.debug_info,\"dr\"";
 118     DwarfLineSection =    "\t.section\t.debug_line,\"dr\"";
 119     DwarfFrameSection =   "\t.section\t.debug_frame,\"dr\"";
 120     DwarfPubNamesSection ="\t.section\t.debug_pubnames,\"dr\"";
 121     DwarfPubTypesSection ="\t.section\t.debug_pubtypes,\"dr\"";
 122     DwarfStrSection =     "\t.section\t.debug_str,\"dr\"";
 123     DwarfLocSection =     "\t.section\t.debug_loc,\"dr\"";
 124     DwarfARangesSection = "\t.section\t.debug_aranges,\"dr\"";
 125     DwarfRangesSection =  "\t.section\t.debug_ranges,\"dr\"";
 126     DwarfMacInfoSection = "\t.section\t.debug_macinfo,\"dr\"";
 127     break;
 128
 129     break;
 130   case X86Subtarget::isWindows:
 131     GlobalPrefix = "_";
 132     HasDotTypeDotSizeDirective = false;
 133     break;
 134   default: break;
 135   }
 136
 137   if (Subtarget->isFlavorIntel()) {
 138     GlobalPrefix = "_";
 139     CommentString = ";";
 140
 141     PrivateGlobalPrefix = "$";
 142     AlignDirective = "\talign\t";
 143     ZeroDirective = "\tdb\t";
 144     ZeroDirectiveSuffix = " dup(0)";
 145     AsciiDirective = "\tdb\t";
 146     AscizDirective = 0;
 147     Data8bitsDirective = "\tdb\t";
 148     Data16bitsDirective = "\tdw\t";
 149     Data32bitsDirective = "\tdd\t";
 150     Data64bitsDirective = "\tdq\t";
 151     HasDotTypeDotSizeDirective = false;
 152
 153     TextSection = "_text";
 154     DataSection = "_data";
 155     JumpTableDataSection = NULL;
 156     SwitchToSectionDirective = "";
 157     TextSectionStartSuffix = "\tsegment 'CODE'";
 158     DataSectionStartSuffix = "\tsegment 'DATA'";
 159     SectionEndDirectiveSuffix = "\tends\n";
 160   }
 161 }
 162
 163 bool X86TargetAsmInfo::LowerToBSwap(CallInst *CI) const {
 164   // FIXME: this should verify that we are targetting a 486 or better.  If not,
 165   // we will turn this bswap into something that will be lowered to logical ops
 166   // instead of emitting the bswap asm.  For now, we don't support 486 or lower
 167   // so don't worry about this.
 168
 169   // Verify this is a simple bswap.
 170   if (CI->getNumOperands() != 2 ||
 171       CI->getType() != CI->getOperand(1)->getType() ||
 172       !CI->getType()->isInteger())
 173     return false;
 174
 175   const Type *Ty = CI->getType()->getUnsignedVersion();
 176   const char *IntName;
 177   switch (Ty->getTypeID()) {
 178   default: return false;
 179   case Type::UShortTyID: IntName = "llvm.bswap.i16"; break;
 180   case Type::UIntTyID:   IntName = "llvm.bswap.i32"; break;
 181   case Type::ULongTyID:  IntName = "llvm.bswap.i64"; break;
 182   }
 183
 184   // Okay, we can do this xform, do so now.
 185   Module *M = CI->getParent()->getParent()->getParent();
 186   Function *Int = M->getOrInsertFunction(IntName, Ty, Ty, (Type*)0);
 187
 188   Value *Op = CI->getOperand(1);
 189   if (CI->getOperand(1)->getType() != Ty)
 190     Op = new BitCastInst(Op, Ty, Op->getName(), CI);
 191
 192   Op = new CallInst(Int, Op, CI->getName(), CI);
 193
 194   if (Op->getType() != CI->getType())
 195     Op = new BitCastInst(Op, CI->getType(), Op->getName(), CI);
 196
 197   CI->replaceAllUsesWith(Op);
 198   CI->eraseFromParent();
 199   return true;
 200 }
 201
 202
 203 bool X86TargetAsmInfo::ExpandInlineAsm(CallInst *CI) const {
 204   InlineAsm *IA = cast<InlineAsm>(CI->getCalledValue());
 205   std::vector<InlineAsm::ConstraintInfo> Constraints = IA->ParseConstraints();
 206
 207   std::string AsmStr = IA->getAsmString();
 208
 209   // TODO: should remove alternatives from the asmstring: "foo {a|b}" -> "foo a"
 210   std::vector<std::string> AsmPieces;
 211   SplitString(AsmStr, AsmPieces, "\n");  // ; as separator?
 212
 213   switch (AsmPieces.size()) {
 214   default: return false;
 215   case 1:
 216     AsmStr = AsmPieces[0];
 217     AsmPieces.clear();
 218     SplitString(AsmStr, AsmPieces, " \t");  // Split with whitespace.
 219
 220     // bswap $0
 221     if (AsmPieces.size() == 2 &&
 222         AsmPieces[0] == "bswap" && AsmPieces[1] == "$0") {
 223       // No need to check constraints, nothing other than the equivalent of
 224       // "=r,0" would be valid here.
 225       return LowerToBSwap(CI);
 226     }
 227     break;
 228   case 3:
 229     if (CI->getType() == Type::ULongTy && Constraints.size() >= 2 &&
 230         Constraints[0].Codes.size() == 1 && Constraints[0].Codes[0] == "A" &&
 231         Constraints[1].Codes.size() == 1 && Constraints[1].Codes[0] == "0") {
 232       // bswap %eax / bswap %edx / xchgl %eax, %edx  -> llvm.bswap.i64
 233       std::vector<std::string> Words;
 234       SplitString(AsmPieces[0], Words, " \t");
 235       if (Words.size() == 2 && Words[0] == "bswap" && Words[1] == "%eax") {
 236         Words.clear();
 237         SplitString(AsmPieces[1], Words, " \t");
 238         if (Words.size() == 2 && Words[0] == "bswap" && Words[1] == "%edx") {
 239           Words.clear();
 240           SplitString(AsmPieces[2], Words, " \t,");
 241           if (Words.size() == 3 && Words[0] == "xchgl" && Words[1] == "%eax" &&
 242               Words[2] == "%edx") {
 243             return LowerToBSwap(CI);
 244           }
 245         }
 246       }
 247     }
 248     break;
 249   }
 250   return false;
 251 }