TargetInfo.cpp revision 249423 
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>
22using namespace clang;
23
24static const LangAS::Map DefaultAddrSpaceMap = { 0 };
25
26// TargetInfo Constructor.
27TargetInfo::TargetInfo(const std::string &T) : TargetOpts(), Triple(T)
28{
29  // Set defaults.  Defaults are set for a 32-bit RISC platform, like PPC or
30  // SPARC.  These should be overridden by concrete targets as needed.
31  BigEndian = true;
32  TLSSupported = true;
33  NoAsmVariants = 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  HalfWidth = 16;
41  HalfAlign = 16;
42  FloatWidth = 32;
43  FloatAlign = 32;
44  DoubleWidth = 64;
45  DoubleAlign = 64;
46  LongDoubleWidth = 64;
47  LongDoubleAlign = 64;
48  LargeArrayMinWidth = 0;
49  LargeArrayAlign = 0;
50  MaxAtomicPromoteWidth = MaxAtomicInlineWidth = 0;
51  MaxVectorAlign = 0;
52  SizeType = UnsignedLong;
53  PtrDiffType = SignedLong;
54  IntMaxType = SignedLongLong;
55  UIntMaxType = UnsignedLongLong;
56  IntPtrType = SignedLong;
57  WCharType = SignedInt;
58  WIntType = SignedInt;
59  Char16Type = UnsignedShort;
60  Char32Type = UnsignedInt;
61  Int64Type = SignedLongLong;
62  SigAtomicType = SignedInt;
63  ProcessIDType = SignedInt;
64  UseSignedCharForObjCBool = true;
65  UseBitFieldTypeAlignment = true;
66  UseZeroLengthBitfieldAlignment = false;
67  ZeroLengthBitfieldBoundary = 0;
68  HalfFormat = &llvm::APFloat::IEEEhalf;
69  FloatFormat = &llvm::APFloat::IEEEsingle;
70  DoubleFormat = &llvm::APFloat::IEEEdouble;
71  LongDoubleFormat = &llvm::APFloat::IEEEdouble;
72  DescriptionString = "E-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-"
73                      "i64:64:64-f32:32:32-f64:64:64-n32";
74  UserLabelPrefix = "_";
75  MCountName = "mcount";
76  RegParmMax = 0;
77  SSERegParmMax = 0;
78  HasAlignMac68kSupport = false;
79
80  // Default to no types using fpret.
81  RealTypeUsesObjCFPRet = 0;
82
83  // Default to not using fp2ret for __Complex long double
84  ComplexLongDoubleUsesFP2Ret = false;
85
86  // Default to using the Itanium ABI.
87  TheCXXABI.set(TargetCXXABI::GenericItanium);
88
89  // Default to an empty address space map.
90  AddrSpaceMap = &DefaultAddrSpaceMap;
91
92  // Default to an unknown platform name.
93  PlatformName = "unknown";
94  PlatformMinVersion = VersionTuple();
95}
96
97// Out of line virtual dtor for TargetInfo.
98TargetInfo::~TargetInfo() {}
99
100/// getTypeName - Return the user string for the specified integer type enum.
101/// For example, SignedShort -> "short".
102const char *TargetInfo::getTypeName(IntType T) {
103  switch (T) {
104  default: llvm_unreachable("not an integer!");
105  case SignedShort:      return "short";
106  case UnsignedShort:    return "unsigned short";
107  case SignedInt:        return "int";
108  case UnsignedInt:      return "unsigned int";
109  case SignedLong:       return "long int";
110  case UnsignedLong:     return "long unsigned int";
111  case SignedLongLong:   return "long long int";
112  case UnsignedLongLong: return "long long unsigned int";
113  }
114}
115
116/// getTypeConstantSuffix - Return the constant suffix for the specified
117/// integer type enum. For example, SignedLong -> "L".
118const char *TargetInfo::getTypeConstantSuffix(IntType T) {
119  switch (T) {
120  default: llvm_unreachable("not an integer!");
121  case SignedShort:
122  case SignedInt:        return "";
123  case SignedLong:       return "L";
124  case SignedLongLong:   return "LL";
125  case UnsignedShort:
126  case UnsignedInt:      return "U";
127  case UnsignedLong:     return "UL";
128  case UnsignedLongLong: return "ULL";
129  }
130}
131
132/// getTypeWidth - Return the width (in bits) of the specified integer type
133/// enum. For example, SignedInt -> getIntWidth().
134unsigned TargetInfo::getTypeWidth(IntType T) const {
135  switch (T) {
136  default: llvm_unreachable("not an integer!");
137  case SignedShort:
138  case UnsignedShort:    return getShortWidth();
139  case SignedInt:
140  case UnsignedInt:      return getIntWidth();
141  case SignedLong:
142  case UnsignedLong:     return getLongWidth();
143  case SignedLongLong:
144  case UnsignedLongLong: return getLongLongWidth();
145  };
146}
147
148/// getTypeAlign - Return the alignment (in bits) of the specified integer type
149/// enum. For example, SignedInt -> getIntAlign().
150unsigned TargetInfo::getTypeAlign(IntType T) const {
151  switch (T) {
152  default: llvm_unreachable("not an integer!");
153  case SignedShort:
154  case UnsignedShort:    return getShortAlign();
155  case SignedInt:
156  case UnsignedInt:      return getIntAlign();
157  case SignedLong:
158  case UnsignedLong:     return getLongAlign();
159  case SignedLongLong:
160  case UnsignedLongLong: return getLongLongAlign();
161  };
162}
163
164/// isTypeSigned - Return whether an integer types is signed. Returns true if
165/// the type is signed; false otherwise.
166bool TargetInfo::isTypeSigned(IntType T) {
167  switch (T) {
168  default: llvm_unreachable("not an integer!");
169  case SignedShort:
170  case SignedInt:
171  case SignedLong:
172  case SignedLongLong:
173    return true;
174  case UnsignedShort:
175  case UnsignedInt:
176  case UnsignedLong:
177  case UnsignedLongLong:
178    return false;
179  };
180}
181
182/// setForcedLangOptions - Set forced language options.
183/// Apply changes to the target information with respect to certain
184/// language options which change the target configuration.
185void TargetInfo::setForcedLangOptions(LangOptions &Opts) {
186  if (Opts.NoBitFieldTypeAlign)
187    UseBitFieldTypeAlignment = false;
188  if (Opts.ShortWChar)
189    WCharType = UnsignedShort;
190}
191
192//===----------------------------------------------------------------------===//
193
194
195static StringRef removeGCCRegisterPrefix(StringRef Name) {
196  if (Name[0] == '%' || Name[0] == '#')
197    Name = Name.substr(1);
198
199  return Name;
200}
201
202/// isValidClobber - Returns whether the passed in string is
203/// a valid clobber in an inline asm statement. This is used by
204/// Sema.
205bool TargetInfo::isValidClobber(StringRef Name) const {
206  return (isValidGCCRegisterName(Name) ||
207	  Name == "memory" || Name == "cc");
208}
209
210/// isValidGCCRegisterName - Returns whether the passed in string
211/// is a valid register name according to GCC. This is used by Sema for
212/// inline asm statements.
213bool TargetInfo::isValidGCCRegisterName(StringRef Name) const {
214  if (Name.empty())
215    return false;
216
217  const char * const *Names;
218  unsigned NumNames;
219
220  // Get rid of any register prefix.
221  Name = removeGCCRegisterPrefix(Name);
222
223  getGCCRegNames(Names, NumNames);
224
225  // If we have a number it maps to an entry in the register name array.
226  if (isDigit(Name[0])) {
227    int n;
228    if (!Name.getAsInteger(0, n))
229      return n >= 0 && (unsigned)n < NumNames;
230  }
231
232  // Check register names.
233  for (unsigned i = 0; i < NumNames; i++) {
234    if (Name == Names[i])
235      return true;
236  }
237
238  // Check any additional names that we have.
239  const AddlRegName *AddlNames;
240  unsigned NumAddlNames;
241  getGCCAddlRegNames(AddlNames, NumAddlNames);
242  for (unsigned i = 0; i < NumAddlNames; i++)
243    for (unsigned j = 0; j < llvm::array_lengthof(AddlNames[i].Names); j++) {
244      if (!AddlNames[i].Names[j])
245	break;
246      // Make sure the register that the additional name is for is within
247      // the bounds of the register names from above.
248      if (AddlNames[i].Names[j] == Name && AddlNames[i].RegNum < NumNames)
249	return true;
250  }
251
252  // Now check aliases.
253  const GCCRegAlias *Aliases;
254  unsigned NumAliases;
255
256  getGCCRegAliases(Aliases, NumAliases);
257  for (unsigned i = 0; i < NumAliases; i++) {
258    for (unsigned j = 0 ; j < llvm::array_lengthof(Aliases[i].Aliases); j++) {
259      if (!Aliases[i].Aliases[j])
260        break;
261      if (Aliases[i].Aliases[j] == Name)
262        return true;
263    }
264  }
265
266  return false;
267}
268
269StringRef
270TargetInfo::getNormalizedGCCRegisterName(StringRef Name) const {
271  assert(isValidGCCRegisterName(Name) && "Invalid register passed in");
272
273  // Get rid of any register prefix.
274  Name = removeGCCRegisterPrefix(Name);
275
276  const char * const *Names;
277  unsigned NumNames;
278
279  getGCCRegNames(Names, NumNames);
280
281  // First, check if we have a number.
282  if (isDigit(Name[0])) {
283    int n;
284    if (!Name.getAsInteger(0, n)) {
285      assert(n >= 0 && (unsigned)n < NumNames &&
286             "Out of bounds register number!");
287      return Names[n];
288    }
289  }
290
291  // Check any additional names that we have.
292  const AddlRegName *AddlNames;
293  unsigned NumAddlNames;
294  getGCCAddlRegNames(AddlNames, NumAddlNames);
295  for (unsigned i = 0; i < NumAddlNames; i++)
296    for (unsigned j = 0; j < llvm::array_lengthof(AddlNames[i].Names); j++) {
297      if (!AddlNames[i].Names[j])
298	break;
299      // Make sure the register that the additional name is for is within
300      // the bounds of the register names from above.
301      if (AddlNames[i].Names[j] == Name && AddlNames[i].RegNum < NumNames)
302	return Name;
303    }
304
305  // Now check aliases.
306  const GCCRegAlias *Aliases;
307  unsigned NumAliases;
308
309  getGCCRegAliases(Aliases, NumAliases);
310  for (unsigned i = 0; i < NumAliases; i++) {
311    for (unsigned j = 0 ; j < llvm::array_lengthof(Aliases[i].Aliases); j++) {
312      if (!Aliases[i].Aliases[j])
313        break;
314      if (Aliases[i].Aliases[j] == Name)
315        return Aliases[i].Register;
316    }
317  }
318
319  return Name;
320}
321
322bool TargetInfo::validateOutputConstraint(ConstraintInfo &Info) const {
323  const char *Name = Info.getConstraintStr().c_str();
324  // An output constraint must start with '=' or '+'
325  if (*Name != '=' && *Name != '+')
326    return false;
327
328  if (*Name == '+')
329    Info.setIsReadWrite();
330
331  Name++;
332  while (*Name) {
333    switch (*Name) {
334    default:
335      if (!validateAsmConstraint(Name, Info)) {
336        // FIXME: We temporarily return false
337        // so we can add more constraints as we hit it.
338        // Eventually, an unknown constraint should just be treated as 'g'.
339        return false;
340      }
341    case '&': // early clobber.
342      break;
343    case '%': // commutative.
344      // FIXME: Check that there is a another register after this one.
345      break;
346    case 'r': // general register.
347      Info.setAllowsRegister();
348      break;
349    case 'm': // memory operand.
350    case 'o': // offsetable memory operand.
351    case 'V': // non-offsetable memory operand.
352    case '<': // autodecrement memory operand.
353    case '>': // autoincrement memory operand.
354      Info.setAllowsMemory();
355      break;
356    case 'g': // general register, memory operand or immediate integer.
357    case 'X': // any operand.
358      Info.setAllowsRegister();
359      Info.setAllowsMemory();
360      break;
361    case ',': // multiple alternative constraint.  Pass it.
362      // Handle additional optional '=' or '+' modifiers.
363      if (Name[1] == '=' || Name[1] == '+')
364        Name++;
365      break;
366    case '?': // Disparage slightly code.
367    case '!': // Disparage severely.
368    case '#': // Ignore as constraint.
369    case '*': // Ignore for choosing register preferences.
370      break;  // Pass them.
371    }
372
373    Name++;
374  }
375
376  return true;
377}
378
379bool TargetInfo::resolveSymbolicName(const char *&Name,
380                                     ConstraintInfo *OutputConstraints,
381                                     unsigned NumOutputs,
382                                     unsigned &Index) const {
383  assert(*Name == '[' && "Symbolic name did not start with '['");
384  Name++;
385  const char *Start = Name;
386  while (*Name && *Name != ']')
387    Name++;
388
389  if (!*Name) {
390    // Missing ']'
391    return false;
392  }
393
394  std::string SymbolicName(Start, Name - Start);
395
396  for (Index = 0; Index != NumOutputs; ++Index)
397    if (SymbolicName == OutputConstraints[Index].getName())
398      return true;
399
400  return false;
401}
402
403bool TargetInfo::validateInputConstraint(ConstraintInfo *OutputConstraints,
404                                         unsigned NumOutputs,
405                                         ConstraintInfo &Info) const {
406  const char *Name = Info.ConstraintStr.c_str();
407
408  while (*Name) {
409    switch (*Name) {
410    default:
411      // Check if we have a matching constraint
412      if (*Name >= '0' && *Name <= '9') {
413        unsigned i = *Name - '0';
414
415        // Check if matching constraint is out of bounds.
416        if (i >= NumOutputs)
417          return false;
418
419        // A number must refer to an output only operand.
420        if (OutputConstraints[i].isReadWrite())
421          return false;
422
423        // If the constraint is already tied, it must be tied to the
424        // same operand referenced to by the number.
425        if (Info.hasTiedOperand() && Info.getTiedOperand() != i)
426          return false;
427
428        // The constraint should have the same info as the respective
429        // output constraint.
430        Info.setTiedOperand(i, OutputConstraints[i]);
431      } else if (!validateAsmConstraint(Name, Info)) {
432        // FIXME: This error return is in place temporarily so we can
433        // add more constraints as we hit it.  Eventually, an unknown
434        // constraint should just be treated as 'g'.
435        return false;
436      }
437      break;
438    case '[': {
439      unsigned Index = 0;
440      if (!resolveSymbolicName(Name, OutputConstraints, NumOutputs, Index))
441        return false;
442
443      // If the constraint is already tied, it must be tied to the
444      // same operand referenced to by the number.
445      if (Info.hasTiedOperand() && Info.getTiedOperand() != Index)
446        return false;
447
448      Info.setTiedOperand(Index, OutputConstraints[Index]);
449      break;
450    }
451    case '%': // commutative
452      // FIXME: Fail if % is used with the last operand.
453      break;
454    case 'i': // immediate integer.
455    case 'n': // immediate integer with a known value.
456      break;
457    case 'I':  // Various constant constraints with target-specific meanings.
458    case 'J':
459    case 'K':
460    case 'L':
461    case 'M':
462    case 'N':
463    case 'O':
464    case 'P':
465      break;
466    case 'r': // general register.
467      Info.setAllowsRegister();
468      break;
469    case 'm': // memory operand.
470    case 'o': // offsettable memory operand.
471    case 'V': // non-offsettable memory operand.
472    case '<': // autodecrement memory operand.
473    case '>': // autoincrement memory operand.
474      Info.setAllowsMemory();
475      break;
476    case 'g': // general register, memory operand or immediate integer.
477    case 'X': // any operand.
478      Info.setAllowsRegister();
479      Info.setAllowsMemory();
480      break;
481    case 'E': // immediate floating point.
482    case 'F': // immediate floating point.
483    case 'p': // address operand.
484      break;
485    case ',': // multiple alternative constraint.  Ignore comma.
486      break;
487    case '?': // Disparage slightly code.
488    case '!': // Disparage severely.
489    case '#': // Ignore as constraint.
490    case '*': // Ignore for choosing register preferences.
491      break;  // Pass them.
492    }
493
494    Name++;
495  }
496
497  return true;
498}
499
500bool TargetCXXABI::tryParse(llvm::StringRef name) {
501  const Kind unknown = static_cast<Kind>(-1);
502  Kind kind = llvm::StringSwitch<Kind>(name)
503    .Case("arm", GenericARM)
504    .Case("ios", iOS)
505    .Case("itanium", GenericItanium)
506    .Case("microsoft", Microsoft)
507    .Default(unknown);
508  if (kind == unknown) return false;
509
510  set(kind);
511  return true;
512}
513