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      1 //===--- TargetInfo.cpp - Information about Target machine ----------------===//
      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 TargetInfo and TargetInfoImpl interfaces.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #include "clang/Basic/TargetInfo.h"
     15 #include "clang/Basic/AddressSpaces.h"
     16 #include "clang/Basic/CharInfo.h"
     17 #include "clang/Basic/LangOptions.h"
     18 #include "llvm/ADT/APFloat.h"
     19 #include "llvm/ADT/STLExtras.h"
     20 #include "llvm/Support/ErrorHandling.h"
     21 #include <cstdlib>
     22 using namespace clang;
     23 
     24 static const LangAS::Map DefaultAddrSpaceMap = { 0 };
     25 
     26 // TargetInfo Constructor.
     27 TargetInfo::TargetInfo(const llvm::Triple &T) : TargetOpts(), Triple(T) {
     28   // Set defaults.  Defaults are set for a 32-bit RISC platform, like PPC or
     29   // SPARC.  These should be overridden by concrete targets as needed.
     30   BigEndian = true;
     31   TLSSupported = true;
     32   NoAsmVariants = false;
     33   HasFloat128 = false;
     34   PointerWidth = PointerAlign = 32;
     35   BoolWidth = BoolAlign = 8;
     36   IntWidth = IntAlign = 32;
     37   LongWidth = LongAlign = 32;
     38   LongLongWidth = LongLongAlign = 64;
     39   SuitableAlign = 64;
     40   DefaultAlignForAttributeAligned = 128;
     41   MinGlobalAlign = 0;
     42   HalfWidth = 16;
     43   HalfAlign = 16;
     44   FloatWidth = 32;
     45   FloatAlign = 32;
     46   DoubleWidth = 64;
     47   DoubleAlign = 64;
     48   LongDoubleWidth = 64;
     49   LongDoubleAlign = 64;
     50   Float128Align = 128;
     51   LargeArrayMinWidth = 0;
     52   LargeArrayAlign = 0;
     53   MaxAtomicPromoteWidth = MaxAtomicInlineWidth = 0;
     54   MaxVectorAlign = 0;
     55   MaxTLSAlign = 0;
     56   SimdDefaultAlign = 0;
     57   SizeType = UnsignedLong;
     58   PtrDiffType = SignedLong;
     59   IntMaxType = SignedLongLong;
     60   IntPtrType = SignedLong;
     61   WCharType = SignedInt;
     62   WIntType = SignedInt;
     63   Char16Type = UnsignedShort;
     64   Char32Type = UnsignedInt;
     65   Int64Type = SignedLongLong;
     66   SigAtomicType = SignedInt;
     67   ProcessIDType = SignedInt;
     68   UseSignedCharForObjCBool = true;
     69   UseBitFieldTypeAlignment = true;
     70   UseZeroLengthBitfieldAlignment = false;
     71   UseExplicitBitFieldAlignment = true;
     72   ZeroLengthBitfieldBoundary = 0;
     73   HalfFormat = &llvm::APFloat::IEEEhalf;
     74   FloatFormat = &llvm::APFloat::IEEEsingle;
     75   DoubleFormat = &llvm::APFloat::IEEEdouble;
     76   LongDoubleFormat = &llvm::APFloat::IEEEdouble;
     77   Float128Format = &llvm::APFloat::IEEEquad;
     78   MCountName = "mcount";
     79   RegParmMax = 0;
     80   SSERegParmMax = 0;
     81   HasAlignMac68kSupport = false;
     82   HasBuiltinMSVaList = false;
     83   IsRenderScriptTarget = false;
     84 
     85   // Default to no types using fpret.
     86   RealTypeUsesObjCFPRet = 0;
     87 
     88   // Default to not using fp2ret for __Complex long double
     89   ComplexLongDoubleUsesFP2Ret = false;
     90 
     91   // Set the C++ ABI based on the triple.
     92   TheCXXABI.set(Triple.isKnownWindowsMSVCEnvironment()
     93                     ? TargetCXXABI::Microsoft
     94                     : TargetCXXABI::GenericItanium);
     95 
     96   // Default to an empty address space map.
     97   AddrSpaceMap = &DefaultAddrSpaceMap;
     98   UseAddrSpaceMapMangling = false;
     99 
    100   // Default to an unknown platform name.
    101   PlatformName = "unknown";
    102   PlatformMinVersion = VersionTuple();
    103 }
    104 
    105 // Out of line virtual dtor for TargetInfo.
    106 TargetInfo::~TargetInfo() {}
    107 
    108 /// getTypeName - Return the user string for the specified integer type enum.
    109 /// For example, SignedShort -> "short".
    110 const char *TargetInfo::getTypeName(IntType T) {
    111   switch (T) {
    112   default: llvm_unreachable("not an integer!");
    113   case SignedChar:       return "signed char";
    114   case UnsignedChar:     return "unsigned char";
    115   case SignedShort:      return "short";
    116   case UnsignedShort:    return "unsigned short";
    117   case SignedInt:        return "int";
    118   case UnsignedInt:      return "unsigned int";
    119   case SignedLong:       return "long int";
    120   case UnsignedLong:     return "long unsigned int";
    121   case SignedLongLong:   return "long long int";
    122   case UnsignedLongLong: return "long long unsigned int";
    123   }
    124 }
    125 
    126 /// getTypeConstantSuffix - Return the constant suffix for the specified
    127 /// integer type enum. For example, SignedLong -> "L".
    128 const char *TargetInfo::getTypeConstantSuffix(IntType T) const {
    129   switch (T) {
    130   default: llvm_unreachable("not an integer!");
    131   case SignedChar:
    132   case SignedShort:
    133   case SignedInt:        return "";
    134   case SignedLong:       return "L";
    135   case SignedLongLong:   return "LL";
    136   case UnsignedChar:
    137     if (getCharWidth() < getIntWidth())
    138       return "";
    139   case UnsignedShort:
    140     if (getShortWidth() < getIntWidth())
    141       return "";
    142   case UnsignedInt:      return "U";
    143   case UnsignedLong:     return "UL";
    144   case UnsignedLongLong: return "ULL";
    145   }
    146 }
    147 
    148 /// getTypeFormatModifier - Return the printf format modifier for the
    149 /// specified integer type enum. For example, SignedLong -> "l".
    150 
    151 const char *TargetInfo::getTypeFormatModifier(IntType T) {
    152   switch (T) {
    153   default: llvm_unreachable("not an integer!");
    154   case SignedChar:
    155   case UnsignedChar:     return "hh";
    156   case SignedShort:
    157   case UnsignedShort:    return "h";
    158   case SignedInt:
    159   case UnsignedInt:      return "";
    160   case SignedLong:
    161   case UnsignedLong:     return "l";
    162   case SignedLongLong:
    163   case UnsignedLongLong: return "ll";
    164   }
    165 }
    166 
    167 /// getTypeWidth - Return the width (in bits) of the specified integer type
    168 /// enum. For example, SignedInt -> getIntWidth().
    169 unsigned TargetInfo::getTypeWidth(IntType T) const {
    170   switch (T) {
    171   default: llvm_unreachable("not an integer!");
    172   case SignedChar:
    173   case UnsignedChar:     return getCharWidth();
    174   case SignedShort:
    175   case UnsignedShort:    return getShortWidth();
    176   case SignedInt:
    177   case UnsignedInt:      return getIntWidth();
    178   case SignedLong:
    179   case UnsignedLong:     return getLongWidth();
    180   case SignedLongLong:
    181   case UnsignedLongLong: return getLongLongWidth();
    182   };
    183 }
    184 
    185 TargetInfo::IntType TargetInfo::getIntTypeByWidth(
    186     unsigned BitWidth, bool IsSigned) const {
    187   if (getCharWidth() == BitWidth)
    188     return IsSigned ? SignedChar : UnsignedChar;
    189   if (getShortWidth() == BitWidth)
    190     return IsSigned ? SignedShort : UnsignedShort;
    191   if (getIntWidth() == BitWidth)
    192     return IsSigned ? SignedInt : UnsignedInt;
    193   if (getLongWidth() == BitWidth)
    194     return IsSigned ? SignedLong : UnsignedLong;
    195   if (getLongLongWidth() == BitWidth)
    196     return IsSigned ? SignedLongLong : UnsignedLongLong;
    197   return NoInt;
    198 }
    199 
    200 TargetInfo::IntType TargetInfo::getLeastIntTypeByWidth(unsigned BitWidth,
    201                                                        bool IsSigned) const {
    202   if (getCharWidth() >= BitWidth)
    203     return IsSigned ? SignedChar : UnsignedChar;
    204   if (getShortWidth() >= BitWidth)
    205     return IsSigned ? SignedShort : UnsignedShort;
    206   if (getIntWidth() >= BitWidth)
    207     return IsSigned ? SignedInt : UnsignedInt;
    208   if (getLongWidth() >= BitWidth)
    209     return IsSigned ? SignedLong : UnsignedLong;
    210   if (getLongLongWidth() >= BitWidth)
    211     return IsSigned ? SignedLongLong : UnsignedLongLong;
    212   return NoInt;
    213 }
    214 
    215 TargetInfo::RealType TargetInfo::getRealTypeByWidth(unsigned BitWidth) const {
    216   if (getFloatWidth() == BitWidth)
    217     return Float;
    218   if (getDoubleWidth() == BitWidth)
    219     return Double;
    220 
    221   switch (BitWidth) {
    222   case 96:
    223     if (&getLongDoubleFormat() == &llvm::APFloat::x87DoubleExtended)
    224       return LongDouble;
    225     break;
    226   case 128:
    227     if (&getLongDoubleFormat() == &llvm::APFloat::PPCDoubleDouble ||
    228         &getLongDoubleFormat() == &llvm::APFloat::IEEEquad)
    229       return LongDouble;
    230     if (hasFloat128Type())
    231       return Float128;
    232     break;
    233   }
    234 
    235   return NoFloat;
    236 }
    237 
    238 /// getTypeAlign - Return the alignment (in bits) of the specified integer type
    239 /// enum. For example, SignedInt -> getIntAlign().
    240 unsigned TargetInfo::getTypeAlign(IntType T) const {
    241   switch (T) {
    242   default: llvm_unreachable("not an integer!");
    243   case SignedChar:
    244   case UnsignedChar:     return getCharAlign();
    245   case SignedShort:
    246   case UnsignedShort:    return getShortAlign();
    247   case SignedInt:
    248   case UnsignedInt:      return getIntAlign();
    249   case SignedLong:
    250   case UnsignedLong:     return getLongAlign();
    251   case SignedLongLong:
    252   case UnsignedLongLong: return getLongLongAlign();
    253   };
    254 }
    255 
    256 /// isTypeSigned - Return whether an integer types is signed. Returns true if
    257 /// the type is signed; false otherwise.
    258 bool TargetInfo::isTypeSigned(IntType T) {
    259   switch (T) {
    260   default: llvm_unreachable("not an integer!");
    261   case SignedChar:
    262   case SignedShort:
    263   case SignedInt:
    264   case SignedLong:
    265   case SignedLongLong:
    266     return true;
    267   case UnsignedChar:
    268   case UnsignedShort:
    269   case UnsignedInt:
    270   case UnsignedLong:
    271   case UnsignedLongLong:
    272     return false;
    273   };
    274 }
    275 
    276 /// adjust - Set forced language options.
    277 /// Apply changes to the target information with respect to certain
    278 /// language options which change the target configuration.
    279 void TargetInfo::adjust(const LangOptions &Opts) {
    280   if (Opts.NoBitFieldTypeAlign)
    281     UseBitFieldTypeAlignment = false;
    282   if (Opts.ShortWChar)
    283     WCharType = UnsignedShort;
    284   if (Opts.AlignDouble) {
    285     DoubleAlign = LongLongAlign = 64;
    286     LongDoubleAlign = 64;
    287   }
    288 
    289   if (Opts.OpenCL) {
    290     // OpenCL C requires specific widths for types, irrespective of
    291     // what these normally are for the target.
    292     // We also define long long and long double here, although the
    293     // OpenCL standard only mentions these as "reserved".
    294     IntWidth = IntAlign = 32;
    295     LongWidth = LongAlign = 64;
    296     LongLongWidth = LongLongAlign = 128;
    297     HalfWidth = HalfAlign = 16;
    298     FloatWidth = FloatAlign = 32;
    299 
    300     // Embedded 32-bit targets (OpenCL EP) might have double C type
    301     // defined as float. Let's not override this as it might lead
    302     // to generating illegal code that uses 64bit doubles.
    303     if (DoubleWidth != FloatWidth) {
    304       DoubleWidth = DoubleAlign = 64;
    305       DoubleFormat = &llvm::APFloat::IEEEdouble;
    306     }
    307     LongDoubleWidth = LongDoubleAlign = 128;
    308 
    309     assert(PointerWidth == 32 || PointerWidth == 64);
    310     bool Is32BitArch = PointerWidth == 32;
    311     SizeType = Is32BitArch ? UnsignedInt : UnsignedLong;
    312     PtrDiffType = Is32BitArch ? SignedInt : SignedLong;
    313     IntPtrType = Is32BitArch ? SignedInt : SignedLong;
    314 
    315     IntMaxType = SignedLongLong;
    316     Int64Type = SignedLong;
    317 
    318     HalfFormat = &llvm::APFloat::IEEEhalf;
    319     FloatFormat = &llvm::APFloat::IEEEsingle;
    320     LongDoubleFormat = &llvm::APFloat::IEEEquad;
    321   }
    322 }
    323 
    324 bool TargetInfo::initFeatureMap(
    325     llvm::StringMap<bool> &Features, DiagnosticsEngine &Diags, StringRef CPU,
    326     const std::vector<std::string> &FeatureVec) const {
    327   for (const auto &F : FeatureVec) {
    328     StringRef Name = F;
    329     // Apply the feature via the target.
    330     bool Enabled = Name[0] == '+';
    331     setFeatureEnabled(Features, Name.substr(1), Enabled);
    332   }
    333   return true;
    334 }
    335 
    336 //===----------------------------------------------------------------------===//
    337 
    338 
    339 static StringRef removeGCCRegisterPrefix(StringRef Name) {
    340   if (Name[0] == '%' || Name[0] == '#')
    341     Name = Name.substr(1);
    342 
    343   return Name;
    344 }
    345 
    346 /// isValidClobber - Returns whether the passed in string is
    347 /// a valid clobber in an inline asm statement. This is used by
    348 /// Sema.
    349 bool TargetInfo::isValidClobber(StringRef Name) const {
    350   return (isValidGCCRegisterName(Name) ||
    351           Name == "memory" || Name == "cc");
    352 }
    353 
    354 /// isValidGCCRegisterName - Returns whether the passed in string
    355 /// is a valid register name according to GCC. This is used by Sema for
    356 /// inline asm statements.
    357 bool TargetInfo::isValidGCCRegisterName(StringRef Name) const {
    358   if (Name.empty())
    359     return false;
    360 
    361   // Get rid of any register prefix.
    362   Name = removeGCCRegisterPrefix(Name);
    363   if (Name.empty())
    364     return false;
    365 
    366   ArrayRef<const char *> Names = getGCCRegNames();
    367 
    368   // If we have a number it maps to an entry in the register name array.
    369   if (isDigit(Name[0])) {
    370     unsigned n;
    371     if (!Name.getAsInteger(0, n))
    372       return n < Names.size();
    373   }
    374 
    375   // Check register names.
    376   if (std::find(Names.begin(), Names.end(), Name) != Names.end())
    377     return true;
    378 
    379   // Check any additional names that we have.
    380   for (const AddlRegName &ARN : getGCCAddlRegNames())
    381     for (const char *AN : ARN.Names) {
    382       if (!AN)
    383         break;
    384       // Make sure the register that the additional name is for is within
    385       // the bounds of the register names from above.
    386       if (AN == Name && ARN.RegNum < Names.size())
    387         return true;
    388     }
    389 
    390   // Now check aliases.
    391   for (const GCCRegAlias &GRA : getGCCRegAliases())
    392     for (const char *A : GRA.Aliases) {
    393       if (!A)
    394         break;
    395       if (A == Name)
    396         return true;
    397     }
    398 
    399   return false;
    400 }
    401 
    402 StringRef
    403 TargetInfo::getNormalizedGCCRegisterName(StringRef Name) const {
    404   assert(isValidGCCRegisterName(Name) && "Invalid register passed in");
    405 
    406   // Get rid of any register prefix.
    407   Name = removeGCCRegisterPrefix(Name);
    408 
    409   ArrayRef<const char *> Names = getGCCRegNames();
    410 
    411   // First, check if we have a number.
    412   if (isDigit(Name[0])) {
    413     unsigned n;
    414     if (!Name.getAsInteger(0, n)) {
    415       assert(n < Names.size() && "Out of bounds register number!");
    416       return Names[n];
    417     }
    418   }
    419 
    420   // Check any additional names that we have.
    421   for (const AddlRegName &ARN : getGCCAddlRegNames())
    422     for (const char *AN : ARN.Names) {
    423       if (!AN)
    424         break;
    425       // Make sure the register that the additional name is for is within
    426       // the bounds of the register names from above.
    427       if (AN == Name && ARN.RegNum < Names.size())
    428         return Name;
    429     }
    430 
    431   // Now check aliases.
    432   for (const GCCRegAlias &RA : getGCCRegAliases())
    433     for (const char *A : RA.Aliases) {
    434       if (!A)
    435         break;
    436       if (A == Name)
    437         return RA.Register;
    438     }
    439 
    440   return Name;
    441 }
    442 
    443 bool TargetInfo::validateOutputConstraint(ConstraintInfo &Info) const {
    444   const char *Name = Info.getConstraintStr().c_str();
    445   // An output constraint must start with '=' or '+'
    446   if (*Name != '=' && *Name != '+')
    447     return false;
    448 
    449   if (*Name == '+')
    450     Info.setIsReadWrite();
    451 
    452   Name++;
    453   while (*Name) {
    454     switch (*Name) {
    455     default:
    456       if (!validateAsmConstraint(Name, Info)) {
    457         // FIXME: We temporarily return false
    458         // so we can add more constraints as we hit it.
    459         // Eventually, an unknown constraint should just be treated as 'g'.
    460         return false;
    461       }
    462       break;
    463     case '&': // early clobber.
    464       Info.setEarlyClobber();
    465       break;
    466     case '%': // commutative.
    467       // FIXME: Check that there is a another register after this one.
    468       break;
    469     case 'r': // general register.
    470       Info.setAllowsRegister();
    471       break;
    472     case 'm': // memory operand.
    473     case 'o': // offsetable memory operand.
    474     case 'V': // non-offsetable memory operand.
    475     case '<': // autodecrement memory operand.
    476     case '>': // autoincrement memory operand.
    477       Info.setAllowsMemory();
    478       break;
    479     case 'g': // general register, memory operand or immediate integer.
    480     case 'X': // any operand.
    481       Info.setAllowsRegister();
    482       Info.setAllowsMemory();
    483       break;
    484     case ',': // multiple alternative constraint.  Pass it.
    485       // Handle additional optional '=' or '+' modifiers.
    486       if (Name[1] == '=' || Name[1] == '+')
    487         Name++;
    488       break;
    489     case '#': // Ignore as constraint.
    490       while (Name[1] && Name[1] != ',')
    491         Name++;
    492       break;
    493     case '?': // Disparage slightly code.
    494     case '!': // Disparage severely.
    495     case '*': // Ignore for choosing register preferences.
    496       break;  // Pass them.
    497     }
    498 
    499     Name++;
    500   }
    501 
    502   // Early clobber with a read-write constraint which doesn't permit registers
    503   // is invalid.
    504   if (Info.earlyClobber() && Info.isReadWrite() && !Info.allowsRegister())
    505     return false;
    506 
    507   // If a constraint allows neither memory nor register operands it contains
    508   // only modifiers. Reject it.
    509   return Info.allowsMemory() || Info.allowsRegister();
    510 }
    511 
    512 bool TargetInfo::resolveSymbolicName(const char *&Name,
    513                                      ArrayRef<ConstraintInfo> OutputConstraints,
    514                                      unsigned &Index) const {
    515   assert(*Name == '[' && "Symbolic name did not start with '['");
    516   Name++;
    517   const char *Start = Name;
    518   while (*Name && *Name != ']')
    519     Name++;
    520 
    521   if (!*Name) {
    522     // Missing ']'
    523     return false;
    524   }
    525 
    526   std::string SymbolicName(Start, Name - Start);
    527 
    528   for (Index = 0; Index != OutputConstraints.size(); ++Index)
    529     if (SymbolicName == OutputConstraints[Index].getName())
    530       return true;
    531 
    532   return false;
    533 }
    534 
    535 bool TargetInfo::validateInputConstraint(
    536                               MutableArrayRef<ConstraintInfo> OutputConstraints,
    537                               ConstraintInfo &Info) const {
    538   const char *Name = Info.ConstraintStr.c_str();
    539 
    540   if (!*Name)
    541     return false;
    542 
    543   while (*Name) {
    544     switch (*Name) {
    545     default:
    546       // Check if we have a matching constraint
    547       if (*Name >= '0' && *Name <= '9') {
    548         const char *DigitStart = Name;
    549         while (Name[1] >= '0' && Name[1] <= '9')
    550           Name++;
    551         const char *DigitEnd = Name;
    552         unsigned i;
    553         if (StringRef(DigitStart, DigitEnd - DigitStart + 1)
    554                 .getAsInteger(10, i))
    555           return false;
    556 
    557         // Check if matching constraint is out of bounds.
    558         if (i >= OutputConstraints.size()) return false;
    559 
    560         // A number must refer to an output only operand.
    561         if (OutputConstraints[i].isReadWrite())
    562           return false;
    563 
    564         // If the constraint is already tied, it must be tied to the
    565         // same operand referenced to by the number.
    566         if (Info.hasTiedOperand() && Info.getTiedOperand() != i)
    567           return false;
    568 
    569         // The constraint should have the same info as the respective
    570         // output constraint.
    571         Info.setTiedOperand(i, OutputConstraints[i]);
    572       } else if (!validateAsmConstraint(Name, Info)) {
    573         // FIXME: This error return is in place temporarily so we can
    574         // add more constraints as we hit it.  Eventually, an unknown
    575         // constraint should just be treated as 'g'.
    576         return false;
    577       }
    578       break;
    579     case '[': {
    580       unsigned Index = 0;
    581       if (!resolveSymbolicName(Name, OutputConstraints, Index))
    582         return false;
    583 
    584       // If the constraint is already tied, it must be tied to the
    585       // same operand referenced to by the number.
    586       if (Info.hasTiedOperand() && Info.getTiedOperand() != Index)
    587         return false;
    588 
    589       // A number must refer to an output only operand.
    590       if (OutputConstraints[Index].isReadWrite())
    591         return false;
    592 
    593       Info.setTiedOperand(Index, OutputConstraints[Index]);
    594       break;
    595     }
    596     case '%': // commutative
    597       // FIXME: Fail if % is used with the last operand.
    598       break;
    599     case 'i': // immediate integer.
    600     case 'n': // immediate integer with a known value.
    601       break;
    602     case 'I':  // Various constant constraints with target-specific meanings.
    603     case 'J':
    604     case 'K':
    605     case 'L':
    606     case 'M':
    607     case 'N':
    608     case 'O':
    609     case 'P':
    610       if (!validateAsmConstraint(Name, Info))
    611         return false;
    612       break;
    613     case 'r': // general register.
    614       Info.setAllowsRegister();
    615       break;
    616     case 'm': // memory operand.
    617     case 'o': // offsettable memory operand.
    618     case 'V': // non-offsettable memory operand.
    619     case '<': // autodecrement memory operand.
    620     case '>': // autoincrement memory operand.
    621       Info.setAllowsMemory();
    622       break;
    623     case 'g': // general register, memory operand or immediate integer.
    624     case 'X': // any operand.
    625       Info.setAllowsRegister();
    626       Info.setAllowsMemory();
    627       break;
    628     case 'E': // immediate floating point.
    629     case 'F': // immediate floating point.
    630     case 'p': // address operand.
    631       break;
    632     case ',': // multiple alternative constraint.  Ignore comma.
    633       break;
    634     case '#': // Ignore as constraint.
    635       while (Name[1] && Name[1] != ',')
    636         Name++;
    637       break;
    638     case '?': // Disparage slightly code.
    639     case '!': // Disparage severely.
    640     case '*': // Ignore for choosing register preferences.
    641       break;  // Pass them.
    642     }
    643 
    644     Name++;
    645   }
    646 
    647   return true;
    648 }
    649