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      1 //===-- MipsAsmBackend.cpp - Mips Asm Backend  ----------------------------===//
      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 implements the MipsAsmBackend class.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 //
     14 
     15 #include "MCTargetDesc/MipsFixupKinds.h"
     16 #include "MCTargetDesc/MipsAsmBackend.h"
     17 #include "MCTargetDesc/MipsMCTargetDesc.h"
     18 #include "llvm/MC/MCAsmBackend.h"
     19 #include "llvm/MC/MCAssembler.h"
     20 #include "llvm/MC/MCContext.h"
     21 #include "llvm/MC/MCDirectives.h"
     22 #include "llvm/MC/MCELFObjectWriter.h"
     23 #include "llvm/MC/MCFixupKindInfo.h"
     24 #include "llvm/MC/MCObjectWriter.h"
     25 #include "llvm/MC/MCSubtargetInfo.h"
     26 #include "llvm/Support/ErrorHandling.h"
     27 #include "llvm/Support/MathExtras.h"
     28 #include "llvm/Support/raw_ostream.h"
     29 
     30 using namespace llvm;
     31 
     32 // Prepare value for the target space for it
     33 static unsigned adjustFixupValue(const MCFixup &Fixup, uint64_t Value,
     34                                  MCContext *Ctx = nullptr) {
     35 
     36   unsigned Kind = Fixup.getKind();
     37 
     38   // Add/subtract and shift
     39   switch (Kind) {
     40   default:
     41     return 0;
     42   case FK_Data_2:
     43   case FK_GPRel_4:
     44   case FK_Data_4:
     45   case FK_Data_8:
     46   case Mips::fixup_Mips_LO16:
     47   case Mips::fixup_Mips_GPREL16:
     48   case Mips::fixup_Mips_GPOFF_HI:
     49   case Mips::fixup_Mips_GPOFF_LO:
     50   case Mips::fixup_Mips_GOT_PAGE:
     51   case Mips::fixup_Mips_GOT_OFST:
     52   case Mips::fixup_Mips_GOT_DISP:
     53   case Mips::fixup_Mips_GOT_LO16:
     54   case Mips::fixup_Mips_CALL_LO16:
     55   case Mips::fixup_MICROMIPS_LO16:
     56   case Mips::fixup_MICROMIPS_GOT_PAGE:
     57   case Mips::fixup_MICROMIPS_GOT_OFST:
     58   case Mips::fixup_MICROMIPS_GOT_DISP:
     59   case Mips::fixup_MIPS_PCLO16:
     60     break;
     61   case Mips::fixup_Mips_PC16:
     62     // The displacement is then divided by 4 to give us an 18 bit
     63     // address range. Forcing a signed division because Value can be negative.
     64     Value = (int64_t)Value / 4;
     65     // We now check if Value can be encoded as a 16-bit signed immediate.
     66     if (!isInt<16>(Value) && Ctx) {
     67       Ctx->reportError(Fixup.getLoc(), "out of range PC16 fixup");
     68       return 0;
     69     }
     70     break;
     71   case Mips::fixup_MIPS_PC19_S2:
     72     // Forcing a signed division because Value can be negative.
     73     Value = (int64_t)Value / 4;
     74     // We now check if Value can be encoded as a 19-bit signed immediate.
     75     if (!isInt<19>(Value) && Ctx) {
     76       Ctx->reportError(Fixup.getLoc(), "out of range PC19 fixup");
     77       return 0;
     78     }
     79     break;
     80   case Mips::fixup_Mips_26:
     81     // So far we are only using this type for jumps.
     82     // The displacement is then divided by 4 to give us an 28 bit
     83     // address range.
     84     Value >>= 2;
     85     break;
     86   case Mips::fixup_Mips_HI16:
     87   case Mips::fixup_Mips_GOT_Local:
     88   case Mips::fixup_Mips_GOT_HI16:
     89   case Mips::fixup_Mips_CALL_HI16:
     90   case Mips::fixup_MICROMIPS_HI16:
     91   case Mips::fixup_MIPS_PCHI16:
     92     // Get the 2nd 16-bits. Also add 1 if bit 15 is 1.
     93     Value = ((Value + 0x8000) >> 16) & 0xffff;
     94     break;
     95   case Mips::fixup_Mips_HIGHER:
     96     // Get the 3rd 16-bits.
     97     Value = ((Value + 0x80008000LL) >> 32) & 0xffff;
     98     break;
     99   case Mips::fixup_Mips_HIGHEST:
    100     // Get the 4th 16-bits.
    101     Value = ((Value + 0x800080008000LL) >> 48) & 0xffff;
    102     break;
    103   case Mips::fixup_MICROMIPS_26_S1:
    104     Value >>= 1;
    105     break;
    106   case Mips::fixup_MICROMIPS_PC7_S1:
    107     Value -= 4;
    108     // Forcing a signed division because Value can be negative.
    109     Value = (int64_t) Value / 2;
    110     // We now check if Value can be encoded as a 7-bit signed immediate.
    111     if (!isInt<7>(Value) && Ctx) {
    112       Ctx->reportError(Fixup.getLoc(), "out of range PC7 fixup");
    113       return 0;
    114     }
    115     break;
    116   case Mips::fixup_MICROMIPS_PC10_S1:
    117     Value -= 2;
    118     // Forcing a signed division because Value can be negative.
    119     Value = (int64_t) Value / 2;
    120     // We now check if Value can be encoded as a 10-bit signed immediate.
    121     if (!isInt<10>(Value) && Ctx) {
    122       Ctx->reportError(Fixup.getLoc(), "out of range PC10 fixup");
    123       return 0;
    124     }
    125     break;
    126   case Mips::fixup_MICROMIPS_PC16_S1:
    127     Value -= 4;
    128     // Forcing a signed division because Value can be negative.
    129     Value = (int64_t)Value / 2;
    130     // We now check if Value can be encoded as a 16-bit signed immediate.
    131     if (!isInt<16>(Value) && Ctx) {
    132       Ctx->reportError(Fixup.getLoc(), "out of range PC16 fixup");
    133       return 0;
    134     }
    135     break;
    136   case Mips::fixup_MIPS_PC18_S3:
    137     // Forcing a signed division because Value can be negative.
    138     Value = (int64_t)Value / 8;
    139     // We now check if Value can be encoded as a 18-bit signed immediate.
    140     if (!isInt<18>(Value) && Ctx) {
    141       Ctx->reportError(Fixup.getLoc(), "out of range PC18 fixup");
    142       return 0;
    143     }
    144     break;
    145   case Mips::fixup_MIPS_PC21_S2:
    146     // Forcing a signed division because Value can be negative.
    147     Value = (int64_t) Value / 4;
    148     // We now check if Value can be encoded as a 21-bit signed immediate.
    149     if (!isInt<21>(Value) && Ctx) {
    150       Ctx->reportError(Fixup.getLoc(), "out of range PC21 fixup");
    151       return 0;
    152     }
    153     break;
    154   case Mips::fixup_MIPS_PC26_S2:
    155     // Forcing a signed division because Value can be negative.
    156     Value = (int64_t) Value / 4;
    157     // We now check if Value can be encoded as a 26-bit signed immediate.
    158     if (!isInt<26>(Value) && Ctx) {
    159       Ctx->reportError(Fixup.getLoc(), "out of range PC26 fixup");
    160       return 0;
    161     }
    162     break;
    163   }
    164 
    165   return Value;
    166 }
    167 
    168 MCObjectWriter *
    169 MipsAsmBackend::createObjectWriter(raw_pwrite_stream &OS) const {
    170   return createMipsELFObjectWriter(OS,
    171     MCELFObjectTargetWriter::getOSABI(OSType), IsLittle, Is64Bit);
    172 }
    173 
    174 // Little-endian fixup data byte ordering:
    175 //   mips32r2:   a | b | x | x
    176 //   microMIPS:  x | x | a | b
    177 
    178 static bool needsMMLEByteOrder(unsigned Kind) {
    179   return Kind != Mips::fixup_MICROMIPS_PC10_S1 &&
    180          Kind >= Mips::fixup_MICROMIPS_26_S1 &&
    181          Kind < Mips::LastTargetFixupKind;
    182 }
    183 
    184 // Calculate index for microMIPS specific little endian byte order
    185 static unsigned calculateMMLEIndex(unsigned i) {
    186   assert(i <= 3 && "Index out of range!");
    187 
    188   return (1 - i / 2) * 2 + i % 2;
    189 }
    190 
    191 /// ApplyFixup - Apply the \p Value for given \p Fixup into the provided
    192 /// data fragment, at the offset specified by the fixup and following the
    193 /// fixup kind as appropriate.
    194 void MipsAsmBackend::applyFixup(const MCFixup &Fixup, char *Data,
    195                                 unsigned DataSize, uint64_t Value,
    196                                 bool IsPCRel) const {
    197   MCFixupKind Kind = Fixup.getKind();
    198   Value = adjustFixupValue(Fixup, Value);
    199 
    200   if (!Value)
    201     return; // Doesn't change encoding.
    202 
    203   // Where do we start in the object
    204   unsigned Offset = Fixup.getOffset();
    205   // Number of bytes we need to fixup
    206   unsigned NumBytes = (getFixupKindInfo(Kind).TargetSize + 7) / 8;
    207   // Used to point to big endian bytes
    208   unsigned FullSize;
    209 
    210   switch ((unsigned)Kind) {
    211   case FK_Data_2:
    212   case Mips::fixup_Mips_16:
    213   case Mips::fixup_MICROMIPS_PC10_S1:
    214     FullSize = 2;
    215     break;
    216   case FK_Data_8:
    217   case Mips::fixup_Mips_64:
    218     FullSize = 8;
    219     break;
    220   case FK_Data_4:
    221   default:
    222     FullSize = 4;
    223     break;
    224   }
    225 
    226   // Grab current value, if any, from bits.
    227   uint64_t CurVal = 0;
    228 
    229   bool microMipsLEByteOrder = needsMMLEByteOrder((unsigned) Kind);
    230 
    231   for (unsigned i = 0; i != NumBytes; ++i) {
    232     unsigned Idx = IsLittle ? (microMipsLEByteOrder ? calculateMMLEIndex(i)
    233                                                     : i)
    234                             : (FullSize - 1 - i);
    235     CurVal |= (uint64_t)((uint8_t)Data[Offset + Idx]) << (i*8);
    236   }
    237 
    238   uint64_t Mask = ((uint64_t)(-1) >>
    239                     (64 - getFixupKindInfo(Kind).TargetSize));
    240   CurVal |= Value & Mask;
    241 
    242   // Write out the fixed up bytes back to the code/data bits.
    243   for (unsigned i = 0; i != NumBytes; ++i) {
    244     unsigned Idx = IsLittle ? (microMipsLEByteOrder ? calculateMMLEIndex(i)
    245                                                     : i)
    246                             : (FullSize - 1 - i);
    247     Data[Offset + Idx] = (uint8_t)((CurVal >> (i*8)) & 0xff);
    248   }
    249 }
    250 
    251 bool MipsAsmBackend::getFixupKind(StringRef Name, MCFixupKind &MappedKind) const {
    252   if (Name == "R_MIPS_NONE") {
    253     MappedKind = (MCFixupKind)Mips::fixup_Mips_NONE;
    254     return true;
    255   }
    256   if (Name == "R_MIPS_32") {
    257     MappedKind = FK_Data_4;
    258     return true;
    259   }
    260   return MCAsmBackend::getFixupKind(Name, MappedKind);
    261 }
    262 
    263 const MCFixupKindInfo &MipsAsmBackend::
    264 getFixupKindInfo(MCFixupKind Kind) const {
    265   const static MCFixupKindInfo LittleEndianInfos[Mips::NumTargetFixupKinds] = {
    266     // This table *must* be in same the order of fixup_* kinds in
    267     // MipsFixupKinds.h.
    268     //
    269     // name                    offset  bits  flags
    270     { "fixup_Mips_NONE",         0,      0,   0 },
    271     { "fixup_Mips_16",           0,     16,   0 },
    272     { "fixup_Mips_32",           0,     32,   0 },
    273     { "fixup_Mips_REL32",        0,     32,   0 },
    274     { "fixup_Mips_26",           0,     26,   0 },
    275     { "fixup_Mips_HI16",         0,     16,   0 },
    276     { "fixup_Mips_LO16",         0,     16,   0 },
    277     { "fixup_Mips_GPREL16",      0,     16,   0 },
    278     { "fixup_Mips_LITERAL",      0,     16,   0 },
    279     { "fixup_Mips_GOT_Global",   0,     16,   0 },
    280     { "fixup_Mips_GOT_Local",    0,     16,   0 },
    281     { "fixup_Mips_PC16",         0,     16,  MCFixupKindInfo::FKF_IsPCRel },
    282     { "fixup_Mips_CALL16",       0,     16,   0 },
    283     { "fixup_Mips_GPREL32",      0,     32,   0 },
    284     { "fixup_Mips_SHIFT5",       6,      5,   0 },
    285     { "fixup_Mips_SHIFT6",       6,      5,   0 },
    286     { "fixup_Mips_64",           0,     64,   0 },
    287     { "fixup_Mips_TLSGD",        0,     16,   0 },
    288     { "fixup_Mips_GOTTPREL",     0,     16,   0 },
    289     { "fixup_Mips_TPREL_HI",     0,     16,   0 },
    290     { "fixup_Mips_TPREL_LO",     0,     16,   0 },
    291     { "fixup_Mips_TLSLDM",       0,     16,   0 },
    292     { "fixup_Mips_DTPREL_HI",    0,     16,   0 },
    293     { "fixup_Mips_DTPREL_LO",    0,     16,   0 },
    294     { "fixup_Mips_Branch_PCRel", 0,     16,  MCFixupKindInfo::FKF_IsPCRel },
    295     { "fixup_Mips_GPOFF_HI",     0,     16,   0 },
    296     { "fixup_Mips_GPOFF_LO",     0,     16,   0 },
    297     { "fixup_Mips_GOT_PAGE",     0,     16,   0 },
    298     { "fixup_Mips_GOT_OFST",     0,     16,   0 },
    299     { "fixup_Mips_GOT_DISP",     0,     16,   0 },
    300     { "fixup_Mips_HIGHER",       0,     16,   0 },
    301     { "fixup_Mips_HIGHEST",      0,     16,   0 },
    302     { "fixup_Mips_GOT_HI16",     0,     16,   0 },
    303     { "fixup_Mips_GOT_LO16",     0,     16,   0 },
    304     { "fixup_Mips_CALL_HI16",    0,     16,   0 },
    305     { "fixup_Mips_CALL_LO16",    0,     16,   0 },
    306     { "fixup_Mips_PC18_S3",      0,     18,  MCFixupKindInfo::FKF_IsPCRel },
    307     { "fixup_MIPS_PC19_S2",      0,     19,  MCFixupKindInfo::FKF_IsPCRel },
    308     { "fixup_MIPS_PC21_S2",      0,     21,  MCFixupKindInfo::FKF_IsPCRel },
    309     { "fixup_MIPS_PC26_S2",      0,     26,  MCFixupKindInfo::FKF_IsPCRel },
    310     { "fixup_MIPS_PCHI16",       0,     16,  MCFixupKindInfo::FKF_IsPCRel },
    311     { "fixup_MIPS_PCLO16",       0,     16,  MCFixupKindInfo::FKF_IsPCRel },
    312     { "fixup_MICROMIPS_26_S1",   0,     26,   0 },
    313     { "fixup_MICROMIPS_HI16",    0,     16,   0 },
    314     { "fixup_MICROMIPS_LO16",    0,     16,   0 },
    315     { "fixup_MICROMIPS_GOT16",   0,     16,   0 },
    316     { "fixup_MICROMIPS_PC7_S1",  0,      7,   MCFixupKindInfo::FKF_IsPCRel },
    317     { "fixup_MICROMIPS_PC10_S1", 0,     10,   MCFixupKindInfo::FKF_IsPCRel },
    318     { "fixup_MICROMIPS_PC16_S1", 0,     16,   MCFixupKindInfo::FKF_IsPCRel },
    319     { "fixup_MICROMIPS_CALL16",  0,     16,   0 },
    320     { "fixup_MICROMIPS_GOT_DISP",        0,     16,   0 },
    321     { "fixup_MICROMIPS_GOT_PAGE",        0,     16,   0 },
    322     { "fixup_MICROMIPS_GOT_OFST",        0,     16,   0 },
    323     { "fixup_MICROMIPS_TLS_GD",          0,     16,   0 },
    324     { "fixup_MICROMIPS_TLS_LDM",         0,     16,   0 },
    325     { "fixup_MICROMIPS_TLS_DTPREL_HI16", 0,     16,   0 },
    326     { "fixup_MICROMIPS_TLS_DTPREL_LO16", 0,     16,   0 },
    327     { "fixup_MICROMIPS_TLS_TPREL_HI16",  0,     16,   0 },
    328     { "fixup_MICROMIPS_TLS_TPREL_LO16",  0,     16,   0 }
    329   };
    330 
    331   const static MCFixupKindInfo BigEndianInfos[Mips::NumTargetFixupKinds] = {
    332     // This table *must* be in same the order of fixup_* kinds in
    333     // MipsFixupKinds.h.
    334     //
    335     // name                    offset  bits  flags
    336     { "fixup_Mips_NONE",         0,      0,   0 },
    337     { "fixup_Mips_16",          16,     16,   0 },
    338     { "fixup_Mips_32",           0,     32,   0 },
    339     { "fixup_Mips_REL32",        0,     32,   0 },
    340     { "fixup_Mips_26",           6,     26,   0 },
    341     { "fixup_Mips_HI16",        16,     16,   0 },
    342     { "fixup_Mips_LO16",        16,     16,   0 },
    343     { "fixup_Mips_GPREL16",     16,     16,   0 },
    344     { "fixup_Mips_LITERAL",     16,     16,   0 },
    345     { "fixup_Mips_GOT_Global",  16,     16,   0 },
    346     { "fixup_Mips_GOT_Local",   16,     16,   0 },
    347     { "fixup_Mips_PC16",        16,     16,  MCFixupKindInfo::FKF_IsPCRel },
    348     { "fixup_Mips_CALL16",      16,     16,   0 },
    349     { "fixup_Mips_GPREL32",      0,     32,   0 },
    350     { "fixup_Mips_SHIFT5",      21,      5,   0 },
    351     { "fixup_Mips_SHIFT6",      21,      5,   0 },
    352     { "fixup_Mips_64",           0,     64,   0 },
    353     { "fixup_Mips_TLSGD",       16,     16,   0 },
    354     { "fixup_Mips_GOTTPREL",    16,     16,   0 },
    355     { "fixup_Mips_TPREL_HI",    16,     16,   0 },
    356     { "fixup_Mips_TPREL_LO",    16,     16,   0 },
    357     { "fixup_Mips_TLSLDM",      16,     16,   0 },
    358     { "fixup_Mips_DTPREL_HI",   16,     16,   0 },
    359     { "fixup_Mips_DTPREL_LO",   16,     16,   0 },
    360     { "fixup_Mips_Branch_PCRel",16,     16,  MCFixupKindInfo::FKF_IsPCRel },
    361     { "fixup_Mips_GPOFF_HI",    16,     16,   0 },
    362     { "fixup_Mips_GPOFF_LO",    16,     16,   0 },
    363     { "fixup_Mips_GOT_PAGE",    16,     16,   0 },
    364     { "fixup_Mips_GOT_OFST",    16,     16,   0 },
    365     { "fixup_Mips_GOT_DISP",    16,     16,   0 },
    366     { "fixup_Mips_HIGHER",      16,     16,   0 },
    367     { "fixup_Mips_HIGHEST",     16,     16,   0 },
    368     { "fixup_Mips_GOT_HI16",    16,     16,   0 },
    369     { "fixup_Mips_GOT_LO16",    16,     16,   0 },
    370     { "fixup_Mips_CALL_HI16",   16,     16,   0 },
    371     { "fixup_Mips_CALL_LO16",   16,     16,   0 },
    372     { "fixup_Mips_PC18_S3",     14,     18,  MCFixupKindInfo::FKF_IsPCRel },
    373     { "fixup_MIPS_PC19_S2",     13,     19,  MCFixupKindInfo::FKF_IsPCRel },
    374     { "fixup_MIPS_PC21_S2",     11,     21,  MCFixupKindInfo::FKF_IsPCRel },
    375     { "fixup_MIPS_PC26_S2",      6,     26,  MCFixupKindInfo::FKF_IsPCRel },
    376     { "fixup_MIPS_PCHI16",      16,     16,  MCFixupKindInfo::FKF_IsPCRel },
    377     { "fixup_MIPS_PCLO16",      16,     16,  MCFixupKindInfo::FKF_IsPCRel },
    378     { "fixup_MICROMIPS_26_S1",   6,     26,   0 },
    379     { "fixup_MICROMIPS_HI16",   16,     16,   0 },
    380     { "fixup_MICROMIPS_LO16",   16,     16,   0 },
    381     { "fixup_MICROMIPS_GOT16",  16,     16,   0 },
    382     { "fixup_MICROMIPS_PC7_S1",  9,      7,   MCFixupKindInfo::FKF_IsPCRel },
    383     { "fixup_MICROMIPS_PC10_S1", 6,     10,   MCFixupKindInfo::FKF_IsPCRel },
    384     { "fixup_MICROMIPS_PC16_S1",16,     16,   MCFixupKindInfo::FKF_IsPCRel },
    385     { "fixup_MICROMIPS_CALL16", 16,     16,   0 },
    386     { "fixup_MICROMIPS_GOT_DISP",        16,     16,   0 },
    387     { "fixup_MICROMIPS_GOT_PAGE",        16,     16,   0 },
    388     { "fixup_MICROMIPS_GOT_OFST",        16,     16,   0 },
    389     { "fixup_MICROMIPS_TLS_GD",          16,     16,   0 },
    390     { "fixup_MICROMIPS_TLS_LDM",         16,     16,   0 },
    391     { "fixup_MICROMIPS_TLS_DTPREL_HI16", 16,     16,   0 },
    392     { "fixup_MICROMIPS_TLS_DTPREL_LO16", 16,     16,   0 },
    393     { "fixup_MICROMIPS_TLS_TPREL_HI16",  16,     16,   0 },
    394     { "fixup_MICROMIPS_TLS_TPREL_LO16",  16,     16,   0 }
    395   };
    396 
    397   if (Kind < FirstTargetFixupKind)
    398     return MCAsmBackend::getFixupKindInfo(Kind);
    399 
    400   assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
    401           "Invalid kind!");
    402 
    403   if (IsLittle)
    404     return LittleEndianInfos[Kind - FirstTargetFixupKind];
    405   return BigEndianInfos[Kind - FirstTargetFixupKind];
    406 }
    407 
    408 /// WriteNopData - Write an (optimal) nop sequence of Count bytes
    409 /// to the given output. If the target cannot generate such a sequence,
    410 /// it should return an error.
    411 ///
    412 /// \return - True on success.
    413 bool MipsAsmBackend::writeNopData(uint64_t Count, MCObjectWriter *OW) const {
    414   // Check for a less than instruction size number of bytes
    415   // FIXME: 16 bit instructions are not handled yet here.
    416   // We shouldn't be using a hard coded number for instruction size.
    417 
    418   // If the count is not 4-byte aligned, we must be writing data into the text
    419   // section (otherwise we have unaligned instructions, and thus have far
    420   // bigger problems), so just write zeros instead.
    421   OW->WriteZeros(Count);
    422   return true;
    423 }
    424 
    425 /// processFixupValue - Target hook to process the literal value of a fixup
    426 /// if necessary.
    427 void MipsAsmBackend::processFixupValue(const MCAssembler &Asm,
    428                                        const MCAsmLayout &Layout,
    429                                        const MCFixup &Fixup,
    430                                        const MCFragment *DF,
    431                                        const MCValue &Target,
    432                                        uint64_t &Value,
    433                                        bool &IsResolved) {
    434   // At this point we'll ignore the value returned by adjustFixupValue as
    435   // we are only checking if the fixup can be applied correctly. We have
    436   // access to MCContext from here which allows us to report a fatal error
    437   // with *possibly* a source code location.
    438   (void)adjustFixupValue(Fixup, Value, &Asm.getContext());
    439 }
    440 
    441 // MCAsmBackend
    442 MCAsmBackend *llvm::createMipsAsmBackendEL32(const Target &T,
    443                                              const MCRegisterInfo &MRI,
    444                                              const Triple &TT, StringRef CPU) {
    445   return new MipsAsmBackend(T, TT.getOS(), /*IsLittle*/ true,
    446                             /*Is64Bit*/ false);
    447 }
    448 
    449 MCAsmBackend *llvm::createMipsAsmBackendEB32(const Target &T,
    450                                              const MCRegisterInfo &MRI,
    451                                              const Triple &TT, StringRef CPU) {
    452   return new MipsAsmBackend(T, TT.getOS(), /*IsLittle*/ false,
    453                             /*Is64Bit*/ false);
    454 }
    455 
    456 MCAsmBackend *llvm::createMipsAsmBackendEL64(const Target &T,
    457                                              const MCRegisterInfo &MRI,
    458                                              const Triple &TT, StringRef CPU) {
    459   return new MipsAsmBackend(T, TT.getOS(), /*IsLittle*/ true, /*Is64Bit*/ true);
    460 }
    461 
    462 MCAsmBackend *llvm::createMipsAsmBackendEB64(const Target &T,
    463                                              const MCRegisterInfo &MRI,
    464                                              const Triple &TT, StringRef CPU) {
    465   return new MipsAsmBackend(T, TT.getOS(), /*IsLittle*/ false,
    466                             /*Is64Bit*/ true);
    467 }
    468