• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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.
TargetInfo(const llvm::Triple & T)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   PointerWidth = PointerAlign = 32;
34   BoolWidth = BoolAlign = 8;
35   IntWidth = IntAlign = 32;
36   LongWidth = LongAlign = 32;
37   LongLongWidth = LongLongAlign = 64;
38   SuitableAlign = 64;
39   DefaultAlignForAttributeAligned = 128;
40   MinGlobalAlign = 0;
41   HalfWidth = 16;
42   HalfAlign = 16;
43   FloatWidth = 32;
44   FloatAlign = 32;
45   DoubleWidth = 64;
46   DoubleAlign = 64;
47   LongDoubleWidth = 64;
48   LongDoubleAlign = 64;
49   LargeArrayMinWidth = 0;
50   LargeArrayAlign = 0;
51   MaxAtomicPromoteWidth = MaxAtomicInlineWidth = 0;
52   MaxVectorAlign = 0;
53   MaxTLSAlign = 0;
54   SimdDefaultAlign = 0;
55   SizeType = UnsignedLong;
56   PtrDiffType = SignedLong;
57   IntMaxType = SignedLongLong;
58   IntPtrType = SignedLong;
59   WCharType = SignedInt;
60   WIntType = SignedInt;
61   Char16Type = UnsignedShort;
62   Char32Type = UnsignedInt;
63   Int64Type = SignedLongLong;
64   SigAtomicType = SignedInt;
65   ProcessIDType = SignedInt;
66   UseSignedCharForObjCBool = true;
67   UseBitFieldTypeAlignment = true;
68   UseZeroLengthBitfieldAlignment = false;
69   ZeroLengthBitfieldBoundary = 0;
70   HalfFormat = &llvm::APFloat::IEEEhalf;
71   FloatFormat = &llvm::APFloat::IEEEsingle;
72   DoubleFormat = &llvm::APFloat::IEEEdouble;
73   LongDoubleFormat = &llvm::APFloat::IEEEdouble;
74   DataLayoutString = nullptr;
75   UserLabelPrefix = "_";
76   MCountName = "mcount";
77   RegParmMax = 0;
78   SSERegParmMax = 0;
79   HasAlignMac68kSupport = false;
80   HasBuiltinMSVaList = false;
81 
82   // Default to no types using fpret.
83   RealTypeUsesObjCFPRet = 0;
84 
85   // Default to not using fp2ret for __Complex long double
86   ComplexLongDoubleUsesFP2Ret = false;
87 
88   // Set the C++ ABI based on the triple.
89   TheCXXABI.set(Triple.isKnownWindowsMSVCEnvironment()
90                     ? TargetCXXABI::Microsoft
91                     : TargetCXXABI::GenericItanium);
92 
93   // Default to an empty address space map.
94   AddrSpaceMap = &DefaultAddrSpaceMap;
95   UseAddrSpaceMapMangling = false;
96 
97   // Default to an unknown platform name.
98   PlatformName = "unknown";
99   PlatformMinVersion = VersionTuple();
100 }
101 
102 // Out of line virtual dtor for TargetInfo.
~TargetInfo()103 TargetInfo::~TargetInfo() {}
104 
105 /// getTypeName - Return the user string for the specified integer type enum.
106 /// For example, SignedShort -> "short".
getTypeName(IntType T)107 const char *TargetInfo::getTypeName(IntType T) {
108   switch (T) {
109   default: llvm_unreachable("not an integer!");
110   case SignedChar:       return "signed char";
111   case UnsignedChar:     return "unsigned char";
112   case SignedShort:      return "short";
113   case UnsignedShort:    return "unsigned short";
114   case SignedInt:        return "int";
115   case UnsignedInt:      return "unsigned int";
116   case SignedLong:       return "long int";
117   case UnsignedLong:     return "long unsigned int";
118   case SignedLongLong:   return "long long int";
119   case UnsignedLongLong: return "long long unsigned int";
120   }
121 }
122 
123 /// getTypeConstantSuffix - Return the constant suffix for the specified
124 /// integer type enum. For example, SignedLong -> "L".
getTypeConstantSuffix(IntType T) const125 const char *TargetInfo::getTypeConstantSuffix(IntType T) const {
126   switch (T) {
127   default: llvm_unreachable("not an integer!");
128   case SignedChar:
129   case SignedShort:
130   case SignedInt:        return "";
131   case SignedLong:       return "L";
132   case SignedLongLong:   return "LL";
133   case UnsignedChar:
134     if (getCharWidth() < getIntWidth())
135       return "";
136   case UnsignedShort:
137     if (getShortWidth() < getIntWidth())
138       return "";
139   case UnsignedInt:      return "U";
140   case UnsignedLong:     return "UL";
141   case UnsignedLongLong: return "ULL";
142   }
143 }
144 
145 /// getTypeFormatModifier - Return the printf format modifier for the
146 /// specified integer type enum. For example, SignedLong -> "l".
147 
getTypeFormatModifier(IntType T)148 const char *TargetInfo::getTypeFormatModifier(IntType T) {
149   switch (T) {
150   default: llvm_unreachable("not an integer!");
151   case SignedChar:
152   case UnsignedChar:     return "hh";
153   case SignedShort:
154   case UnsignedShort:    return "h";
155   case SignedInt:
156   case UnsignedInt:      return "";
157   case SignedLong:
158   case UnsignedLong:     return "l";
159   case SignedLongLong:
160   case UnsignedLongLong: return "ll";
161   }
162 }
163 
164 /// getTypeWidth - Return the width (in bits) of the specified integer type
165 /// enum. For example, SignedInt -> getIntWidth().
getTypeWidth(IntType T) const166 unsigned TargetInfo::getTypeWidth(IntType T) const {
167   switch (T) {
168   default: llvm_unreachable("not an integer!");
169   case SignedChar:
170   case UnsignedChar:     return getCharWidth();
171   case SignedShort:
172   case UnsignedShort:    return getShortWidth();
173   case SignedInt:
174   case UnsignedInt:      return getIntWidth();
175   case SignedLong:
176   case UnsignedLong:     return getLongWidth();
177   case SignedLongLong:
178   case UnsignedLongLong: return getLongLongWidth();
179   };
180 }
181 
getIntTypeByWidth(unsigned BitWidth,bool IsSigned) const182 TargetInfo::IntType TargetInfo::getIntTypeByWidth(
183     unsigned BitWidth, bool IsSigned) const {
184   if (getCharWidth() == BitWidth)
185     return IsSigned ? SignedChar : UnsignedChar;
186   if (getShortWidth() == BitWidth)
187     return IsSigned ? SignedShort : UnsignedShort;
188   if (getIntWidth() == BitWidth)
189     return IsSigned ? SignedInt : UnsignedInt;
190   if (getLongWidth() == BitWidth)
191     return IsSigned ? SignedLong : UnsignedLong;
192   if (getLongLongWidth() == BitWidth)
193     return IsSigned ? SignedLongLong : UnsignedLongLong;
194   return NoInt;
195 }
196 
getLeastIntTypeByWidth(unsigned BitWidth,bool IsSigned) const197 TargetInfo::IntType TargetInfo::getLeastIntTypeByWidth(unsigned BitWidth,
198                                                        bool IsSigned) const {
199   if (getCharWidth() >= BitWidth)
200     return IsSigned ? SignedChar : UnsignedChar;
201   if (getShortWidth() >= BitWidth)
202     return IsSigned ? SignedShort : UnsignedShort;
203   if (getIntWidth() >= BitWidth)
204     return IsSigned ? SignedInt : UnsignedInt;
205   if (getLongWidth() >= BitWidth)
206     return IsSigned ? SignedLong : UnsignedLong;
207   if (getLongLongWidth() >= BitWidth)
208     return IsSigned ? SignedLongLong : UnsignedLongLong;
209   return NoInt;
210 }
211 
getRealTypeByWidth(unsigned BitWidth) const212 TargetInfo::RealType TargetInfo::getRealTypeByWidth(unsigned BitWidth) const {
213   if (getFloatWidth() == BitWidth)
214     return Float;
215   if (getDoubleWidth() == BitWidth)
216     return Double;
217 
218   switch (BitWidth) {
219   case 96:
220     if (&getLongDoubleFormat() == &llvm::APFloat::x87DoubleExtended)
221       return LongDouble;
222     break;
223   case 128:
224     if (&getLongDoubleFormat() == &llvm::APFloat::PPCDoubleDouble ||
225         &getLongDoubleFormat() == &llvm::APFloat::IEEEquad)
226       return LongDouble;
227     break;
228   }
229 
230   return NoFloat;
231 }
232 
233 /// getTypeAlign - Return the alignment (in bits) of the specified integer type
234 /// enum. For example, SignedInt -> getIntAlign().
getTypeAlign(IntType T) const235 unsigned TargetInfo::getTypeAlign(IntType T) const {
236   switch (T) {
237   default: llvm_unreachable("not an integer!");
238   case SignedChar:
239   case UnsignedChar:     return getCharAlign();
240   case SignedShort:
241   case UnsignedShort:    return getShortAlign();
242   case SignedInt:
243   case UnsignedInt:      return getIntAlign();
244   case SignedLong:
245   case UnsignedLong:     return getLongAlign();
246   case SignedLongLong:
247   case UnsignedLongLong: return getLongLongAlign();
248   };
249 }
250 
251 /// isTypeSigned - Return whether an integer types is signed. Returns true if
252 /// the type is signed; false otherwise.
isTypeSigned(IntType T)253 bool TargetInfo::isTypeSigned(IntType T) {
254   switch (T) {
255   default: llvm_unreachable("not an integer!");
256   case SignedChar:
257   case SignedShort:
258   case SignedInt:
259   case SignedLong:
260   case SignedLongLong:
261     return true;
262   case UnsignedChar:
263   case UnsignedShort:
264   case UnsignedInt:
265   case UnsignedLong:
266   case UnsignedLongLong:
267     return false;
268   };
269 }
270 
271 /// adjust - Set forced language options.
272 /// Apply changes to the target information with respect to certain
273 /// language options which change the target configuration.
adjust(const LangOptions & Opts)274 void TargetInfo::adjust(const LangOptions &Opts) {
275   if (Opts.NoBitFieldTypeAlign)
276     UseBitFieldTypeAlignment = false;
277   if (Opts.ShortWChar)
278     WCharType = UnsignedShort;
279 
280   if (Opts.OpenCL) {
281     // OpenCL C requires specific widths for types, irrespective of
282     // what these normally are for the target.
283     // We also define long long and long double here, although the
284     // OpenCL standard only mentions these as "reserved".
285     IntWidth = IntAlign = 32;
286     LongWidth = LongAlign = 64;
287     LongLongWidth = LongLongAlign = 128;
288     HalfWidth = HalfAlign = 16;
289     FloatWidth = FloatAlign = 32;
290 
291     // Embedded 32-bit targets (OpenCL EP) might have double C type
292     // defined as float. Let's not override this as it might lead
293     // to generating illegal code that uses 64bit doubles.
294     if (DoubleWidth != FloatWidth) {
295       DoubleWidth = DoubleAlign = 64;
296       DoubleFormat = &llvm::APFloat::IEEEdouble;
297     }
298     LongDoubleWidth = LongDoubleAlign = 128;
299 
300     assert(PointerWidth == 32 || PointerWidth == 64);
301     bool Is32BitArch = PointerWidth == 32;
302     SizeType = Is32BitArch ? UnsignedInt : UnsignedLong;
303     PtrDiffType = Is32BitArch ? SignedInt : SignedLong;
304     IntPtrType = Is32BitArch ? SignedInt : SignedLong;
305 
306     IntMaxType = SignedLongLong;
307     Int64Type = SignedLong;
308 
309     HalfFormat = &llvm::APFloat::IEEEhalf;
310     FloatFormat = &llvm::APFloat::IEEEsingle;
311     LongDoubleFormat = &llvm::APFloat::IEEEquad;
312   }
313 }
314 
initFeatureMap(llvm::StringMap<bool> & Features,DiagnosticsEngine & Diags,StringRef CPU,const std::vector<std::string> & FeatureVec) const315 bool TargetInfo::initFeatureMap(
316     llvm::StringMap<bool> &Features, DiagnosticsEngine &Diags, StringRef CPU,
317     const std::vector<std::string> &FeatureVec) const {
318   for (const auto &F : FeatureVec) {
319     StringRef Name = F;
320     // Apply the feature via the target.
321     bool Enabled = Name[0] == '+';
322     setFeatureEnabled(Features, Name.substr(1), Enabled);
323   }
324   return true;
325 }
326 
327 //===----------------------------------------------------------------------===//
328 
329 
removeGCCRegisterPrefix(StringRef Name)330 static StringRef removeGCCRegisterPrefix(StringRef Name) {
331   if (Name[0] == '%' || Name[0] == '#')
332     Name = Name.substr(1);
333 
334   return Name;
335 }
336 
337 /// isValidClobber - Returns whether the passed in string is
338 /// a valid clobber in an inline asm statement. This is used by
339 /// Sema.
isValidClobber(StringRef Name) const340 bool TargetInfo::isValidClobber(StringRef Name) const {
341   return (isValidGCCRegisterName(Name) ||
342           Name == "memory" || Name == "cc");
343 }
344 
345 /// isValidGCCRegisterName - Returns whether the passed in string
346 /// is a valid register name according to GCC. This is used by Sema for
347 /// inline asm statements.
isValidGCCRegisterName(StringRef Name) const348 bool TargetInfo::isValidGCCRegisterName(StringRef Name) const {
349   if (Name.empty())
350     return false;
351 
352   // Get rid of any register prefix.
353   Name = removeGCCRegisterPrefix(Name);
354   if (Name.empty())
355     return false;
356 
357   ArrayRef<const char *> Names = getGCCRegNames();
358 
359   // If we have a number it maps to an entry in the register name array.
360   if (isDigit(Name[0])) {
361     unsigned n;
362     if (!Name.getAsInteger(0, n))
363       return n < Names.size();
364   }
365 
366   // Check register names.
367   if (std::find(Names.begin(), Names.end(), Name) != Names.end())
368     return true;
369 
370   // Check any additional names that we have.
371   for (const AddlRegName &ARN : getGCCAddlRegNames())
372     for (const char *AN : ARN.Names) {
373       if (!AN)
374         break;
375       // Make sure the register that the additional name is for is within
376       // the bounds of the register names from above.
377       if (AN == Name && ARN.RegNum < Names.size())
378         return true;
379     }
380 
381   // Now check aliases.
382   for (const GCCRegAlias &GRA : getGCCRegAliases())
383     for (const char *A : GRA.Aliases) {
384       if (!A)
385         break;
386       if (A == Name)
387         return true;
388     }
389 
390   return false;
391 }
392 
393 StringRef
getNormalizedGCCRegisterName(StringRef Name) const394 TargetInfo::getNormalizedGCCRegisterName(StringRef Name) const {
395   assert(isValidGCCRegisterName(Name) && "Invalid register passed in");
396 
397   // Get rid of any register prefix.
398   Name = removeGCCRegisterPrefix(Name);
399 
400   ArrayRef<const char *> Names = getGCCRegNames();
401 
402   // First, check if we have a number.
403   if (isDigit(Name[0])) {
404     unsigned n;
405     if (!Name.getAsInteger(0, n)) {
406       assert(n < Names.size() && "Out of bounds register number!");
407       return Names[n];
408     }
409   }
410 
411   // Check any additional names that we have.
412   for (const AddlRegName &ARN : getGCCAddlRegNames())
413     for (const char *AN : ARN.Names) {
414       if (!AN)
415         break;
416       // Make sure the register that the additional name is for is within
417       // the bounds of the register names from above.
418       if (AN == Name && ARN.RegNum < Names.size())
419         return Name;
420     }
421 
422   // Now check aliases.
423   for (const GCCRegAlias &RA : getGCCRegAliases())
424     for (const char *A : RA.Aliases) {
425       if (!A)
426         break;
427       if (A == Name)
428         return RA.Register;
429     }
430 
431   return Name;
432 }
433 
validateOutputConstraint(ConstraintInfo & Info) const434 bool TargetInfo::validateOutputConstraint(ConstraintInfo &Info) const {
435   const char *Name = Info.getConstraintStr().c_str();
436   // An output constraint must start with '=' or '+'
437   if (*Name != '=' && *Name != '+')
438     return false;
439 
440   if (*Name == '+')
441     Info.setIsReadWrite();
442 
443   Name++;
444   while (*Name) {
445     switch (*Name) {
446     default:
447       if (!validateAsmConstraint(Name, Info)) {
448         // FIXME: We temporarily return false
449         // so we can add more constraints as we hit it.
450         // Eventually, an unknown constraint should just be treated as 'g'.
451         return false;
452       }
453       break;
454     case '&': // early clobber.
455       Info.setEarlyClobber();
456       break;
457     case '%': // commutative.
458       // FIXME: Check that there is a another register after this one.
459       break;
460     case 'r': // general register.
461       Info.setAllowsRegister();
462       break;
463     case 'm': // memory operand.
464     case 'o': // offsetable memory operand.
465     case 'V': // non-offsetable memory operand.
466     case '<': // autodecrement memory operand.
467     case '>': // autoincrement memory operand.
468       Info.setAllowsMemory();
469       break;
470     case 'g': // general register, memory operand or immediate integer.
471     case 'X': // any operand.
472       Info.setAllowsRegister();
473       Info.setAllowsMemory();
474       break;
475     case ',': // multiple alternative constraint.  Pass it.
476       // Handle additional optional '=' or '+' modifiers.
477       if (Name[1] == '=' || Name[1] == '+')
478         Name++;
479       break;
480     case '#': // Ignore as constraint.
481       while (Name[1] && Name[1] != ',')
482         Name++;
483       break;
484     case '?': // Disparage slightly code.
485     case '!': // Disparage severely.
486     case '*': // Ignore for choosing register preferences.
487       break;  // Pass them.
488     }
489 
490     Name++;
491   }
492 
493   // Early clobber with a read-write constraint which doesn't permit registers
494   // is invalid.
495   if (Info.earlyClobber() && Info.isReadWrite() && !Info.allowsRegister())
496     return false;
497 
498   // If a constraint allows neither memory nor register operands it contains
499   // only modifiers. Reject it.
500   return Info.allowsMemory() || Info.allowsRegister();
501 }
502 
resolveSymbolicName(const char * & Name,ArrayRef<ConstraintInfo> OutputConstraints,unsigned & Index) const503 bool TargetInfo::resolveSymbolicName(const char *&Name,
504                                      ArrayRef<ConstraintInfo> OutputConstraints,
505                                      unsigned &Index) const {
506   assert(*Name == '[' && "Symbolic name did not start with '['");
507   Name++;
508   const char *Start = Name;
509   while (*Name && *Name != ']')
510     Name++;
511 
512   if (!*Name) {
513     // Missing ']'
514     return false;
515   }
516 
517   std::string SymbolicName(Start, Name - Start);
518 
519   for (Index = 0; Index != OutputConstraints.size(); ++Index)
520     if (SymbolicName == OutputConstraints[Index].getName())
521       return true;
522 
523   return false;
524 }
525 
validateInputConstraint(MutableArrayRef<ConstraintInfo> OutputConstraints,ConstraintInfo & Info) const526 bool TargetInfo::validateInputConstraint(
527                               MutableArrayRef<ConstraintInfo> OutputConstraints,
528                               ConstraintInfo &Info) const {
529   const char *Name = Info.ConstraintStr.c_str();
530 
531   if (!*Name)
532     return false;
533 
534   while (*Name) {
535     switch (*Name) {
536     default:
537       // Check if we have a matching constraint
538       if (*Name >= '0' && *Name <= '9') {
539         const char *DigitStart = Name;
540         while (Name[1] >= '0' && Name[1] <= '9')
541           Name++;
542         const char *DigitEnd = Name;
543         unsigned i;
544         if (StringRef(DigitStart, DigitEnd - DigitStart + 1)
545                 .getAsInteger(10, i))
546           return false;
547 
548         // Check if matching constraint is out of bounds.
549         if (i >= OutputConstraints.size()) return false;
550 
551         // A number must refer to an output only operand.
552         if (OutputConstraints[i].isReadWrite())
553           return false;
554 
555         // If the constraint is already tied, it must be tied to the
556         // same operand referenced to by the number.
557         if (Info.hasTiedOperand() && Info.getTiedOperand() != i)
558           return false;
559 
560         // The constraint should have the same info as the respective
561         // output constraint.
562         Info.setTiedOperand(i, OutputConstraints[i]);
563       } else if (!validateAsmConstraint(Name, Info)) {
564         // FIXME: This error return is in place temporarily so we can
565         // add more constraints as we hit it.  Eventually, an unknown
566         // constraint should just be treated as 'g'.
567         return false;
568       }
569       break;
570     case '[': {
571       unsigned Index = 0;
572       if (!resolveSymbolicName(Name, OutputConstraints, Index))
573         return false;
574 
575       // If the constraint is already tied, it must be tied to the
576       // same operand referenced to by the number.
577       if (Info.hasTiedOperand() && Info.getTiedOperand() != Index)
578         return false;
579 
580       // A number must refer to an output only operand.
581       if (OutputConstraints[Index].isReadWrite())
582         return false;
583 
584       Info.setTiedOperand(Index, OutputConstraints[Index]);
585       break;
586     }
587     case '%': // commutative
588       // FIXME: Fail if % is used with the last operand.
589       break;
590     case 'i': // immediate integer.
591     case 'n': // immediate integer with a known value.
592       break;
593     case 'I':  // Various constant constraints with target-specific meanings.
594     case 'J':
595     case 'K':
596     case 'L':
597     case 'M':
598     case 'N':
599     case 'O':
600     case 'P':
601       if (!validateAsmConstraint(Name, Info))
602         return false;
603       break;
604     case 'r': // general register.
605       Info.setAllowsRegister();
606       break;
607     case 'm': // memory operand.
608     case 'o': // offsettable memory operand.
609     case 'V': // non-offsettable memory operand.
610     case '<': // autodecrement memory operand.
611     case '>': // autoincrement memory operand.
612       Info.setAllowsMemory();
613       break;
614     case 'g': // general register, memory operand or immediate integer.
615     case 'X': // any operand.
616       Info.setAllowsRegister();
617       Info.setAllowsMemory();
618       break;
619     case 'E': // immediate floating point.
620     case 'F': // immediate floating point.
621     case 'p': // address operand.
622       break;
623     case ',': // multiple alternative constraint.  Ignore comma.
624       break;
625     case '#': // Ignore as constraint.
626       while (Name[1] && Name[1] != ',')
627         Name++;
628       break;
629     case '?': // Disparage slightly code.
630     case '!': // Disparage severely.
631     case '*': // Ignore for choosing register preferences.
632       break;  // Pass them.
633     }
634 
635     Name++;
636   }
637 
638   return true;
639 }
640