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 = ".L";
  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   case X86Subtarget::isMingw:
 107     GlobalPrefix = "_";
 108     LCOMMDirective = "\t.lcomm\t";
 109     COMMDirectiveTakesAlignment = false;
 110     HasDotTypeDotSizeDirective = false;
 111     StaticCtorsSection = "\t.section .ctors,\"aw\"";
 112     StaticDtorsSection = "\t.section .dtors,\"aw\"";
 113
 114     // Set up DWARF directives
 115     HasLEB128 = true;  // Target asm supports leb128 directives (little-endian)
 116     PrivateGlobalPrefix = "L";  // Prefix for private global symbols
 117     DwarfRequiresFrameSection = false;
 118     DwarfAbbrevSection =  "\t.section\t.debug_abbrev,\"dr\"";
 119     DwarfInfoSection =    "\t.section\t.debug_info,\"dr\"";
 120     DwarfLineSection =    "\t.section\t.debug_line,\"dr\"";
 121     DwarfFrameSection =   "\t.section\t.debug_frame,\"dr\"";
 122     DwarfPubNamesSection ="\t.section\t.debug_pubnames,\"dr\"";
 123     DwarfPubTypesSection ="\t.section\t.debug_pubtypes,\"dr\"";
 124     DwarfStrSection =     "\t.section\t.debug_str,\"dr\"";
 125     DwarfLocSection =     "\t.section\t.debug_loc,\"dr\"";
 126     DwarfARangesSection = "\t.section\t.debug_aranges,\"dr\"";
 127     DwarfRangesSection =  "\t.section\t.debug_ranges,\"dr\"";
 128     DwarfMacInfoSection = "\t.section\t.debug_macinfo,\"dr\"";
 129     break;
 130
 131     break;
 132   case X86Subtarget::isWindows:
 133     GlobalPrefix = "_";
 134     HasDotTypeDotSizeDirective = false;
 135     break;
 136   default: break;
 137   }
 138
 139   if (Subtarget->isFlavorIntel()) {
 140     GlobalPrefix = "_";
 141     CommentString = ";";
 142
 143     PrivateGlobalPrefix = "$";
 144     AlignDirective = "\talign\t";
 145     ZeroDirective = "\tdb\t";
 146     ZeroDirectiveSuffix = " dup(0)";
 147     AsciiDirective = "\tdb\t";
 148     AscizDirective = 0;
 149     Data8bitsDirective = "\tdb\t";
 150     Data16bitsDirective = "\tdw\t";
 151     Data32bitsDirective = "\tdd\t";
 152     Data64bitsDirective = "\tdq\t";
 153     HasDotTypeDotSizeDirective = false;
 154
 155     TextSection = "_text";
 156     DataSection = "_data";
 157     JumpTableDataSection = NULL;
 158     SwitchToSectionDirective = "";
 159     TextSectionStartSuffix = "\tsegment 'CODE'";
 160     DataSectionStartSuffix = "\tsegment 'DATA'";
 161     SectionEndDirectiveSuffix = "\tends\n";
 162   }
 163 }
 164
 165 bool X86TargetAsmInfo::LowerToBSwap(CallInst *CI) const {
 166   // FIXME: this should verify that we are targetting a 486 or better.  If not,
 167   // we will turn this bswap into something that will be lowered to logical ops
 168   // instead of emitting the bswap asm.  For now, we don't support 486 or lower
 169   // so don't worry about this.
 170
 171   // Verify this is a simple bswap.
 172   if (CI->getNumOperands() != 2 ||
 173       CI->getType() != CI->getOperand(1)->getType() ||
 174       !CI->getType()->isInteger())
 175     return false;
 176
 177   const Type *Ty = CI->getType();
 178   const char *IntName;
 179   if (const IntegerType *ITy = dyn_cast<IntegerType>(Ty)) {
 180     unsigned BitWidth = ITy->getBitWidth();
 181     if (BitWidth > 8 && BitWidth <= 16)
 182       IntName = "llvm.bswap.i16";
 183     else if (BitWidth > 24  && BitWidth <= 32)
 184       IntName = "llvm.bswap.i32";
 185     else if (BitWidth > 56 && BitWidth <= 64)
 186       IntName = "llvm.bswap.i64";
 187     else
 188       return false;
 189   } else
 190     return false;
 191
 192   // Okay, we can do this xform, do so now.
 193   Module *M = CI->getParent()->getParent()->getParent();
 194   Constant *Int = M->getOrInsertFunction(IntName, Ty, Ty, (Type*)0);
 195
 196   Value *Op = CI->getOperand(1);
 197   Op = new CallInst(Int, Op, CI->getName(), CI);
 198
 199   CI->replaceAllUsesWith(Op);
 200   CI->eraseFromParent();
 201   return true;
 202 }
 203
 204
 205 bool X86TargetAsmInfo::ExpandInlineAsm(CallInst *CI) const {
 206   InlineAsm *IA = cast<InlineAsm>(CI->getCalledValue());
 207   std::vector<InlineAsm::ConstraintInfo> Constraints = IA->ParseConstraints();
 208
 209   std::string AsmStr = IA->getAsmString();
 210
 211   // TODO: should remove alternatives from the asmstring: "foo {a|b}" -> "foo a"
 212   std::vector<std::string> AsmPieces;
 213   SplitString(AsmStr, AsmPieces, "\n");  // ; as separator?
 214
 215   switch (AsmPieces.size()) {
 216   default: return false;
 217   case 1:
 218     AsmStr = AsmPieces[0];
 219     AsmPieces.clear();
 220     SplitString(AsmStr, AsmPieces, " \t");  // Split with whitespace.
 221
 222     // bswap $0
 223     if (AsmPieces.size() == 2 &&
 224         AsmPieces[0] == "bswap" && AsmPieces[1] == "$0") {
 225       // No need to check constraints, nothing other than the equivalent of
 226       // "=r,0" would be valid here.
 227       return LowerToBSwap(CI);
 228     }
 229     break;
 230   case 3:
 231     if (CI->getType() == Type::Int64Ty && Constraints.size() >= 2 &&
 232         Constraints[0].Codes.size() == 1 && Constraints[0].Codes[0] == "A" &&
 233         Constraints[1].Codes.size() == 1 && Constraints[1].Codes[0] == "0") {
 234       // bswap %eax / bswap %edx / xchgl %eax, %edx  -> llvm.bswap.i64
 235       std::vector<std::string> Words;
 236       SplitString(AsmPieces[0], Words, " \t");
 237       if (Words.size() == 2 && Words[0] == "bswap" && Words[1] == "%eax") {
 238         Words.clear();
 239         SplitString(AsmPieces[1], Words, " \t");
 240         if (Words.size() == 2 && Words[0] == "bswap" && Words[1] == "%edx") {
 241           Words.clear();
 242           SplitString(AsmPieces[2], Words, " \t,");
 243           if (Words.size() == 3 && Words[0] == "xchgl" && Words[1] == "%eax" &&
 244               Words[2] == "%edx") {
 245             return LowerToBSwap(CI);
 246           }
 247         }
 248       }
 249     }
 250     break;
 251   }
 252   return false;
 253 }