TargetInfo.cpp revision 221345 
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/AddressSpaces.h"
15#include "clang/Basic/TargetInfo.h"
16#include "clang/Basic/LangOptions.h"
17#include "llvm/ADT/APFloat.h"
18#include "llvm/ADT/STLExtras.h"
19#include <cctype>
20#include <cstdlib>
21using namespace clang;
22
23static const LangAS::Map DefaultAddrSpaceMap = { 0 };
24
25// TargetInfo Constructor.
26TargetInfo::TargetInfo(const std::string &T) : Triple(T) {
27  // Set defaults.  Defaults are set for a 32-bit RISC platform, like PPC or
28  // SPARC.  These should be overridden by concrete targets as needed.
29  TLSSupported = true;
30  NoAsmVariants = false;
31  PointerWidth = PointerAlign = 32;
32  BoolWidth = BoolAlign = 8;
33  IntWidth = IntAlign = 32;
34  LongWidth = LongAlign = 32;
35  LongLongWidth = LongLongAlign = 64;
36  FloatWidth = 32;
37  FloatAlign = 32;
38  DoubleWidth = 64;
39  DoubleAlign = 64;
40  LongDoubleWidth = 64;
41  LongDoubleAlign = 64;
42  LargeArrayMinWidth = 0;
43  LargeArrayAlign = 0;
44  SizeType = UnsignedLong;
45  PtrDiffType = SignedLong;
46  IntMaxType = SignedLongLong;
47  UIntMaxType = UnsignedLongLong;
48  IntPtrType = SignedLong;
49  WCharType = SignedInt;
50  WIntType = SignedInt;
51  Char16Type = UnsignedShort;
52  Char32Type = UnsignedInt;
53  Int64Type = SignedLongLong;
54  SigAtomicType = SignedInt;
55  UseBitFieldTypeAlignment = true;
56  FloatFormat = &llvm::APFloat::IEEEsingle;
57  DoubleFormat = &llvm::APFloat::IEEEdouble;
58  LongDoubleFormat = &llvm::APFloat::IEEEdouble;
59  DescriptionString = "E-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-"
60                      "i64:64:64-f32:32:32-f64:64:64-n32";
61  UserLabelPrefix = "_";
62  MCountName = "mcount";
63  HasAlignMac68kSupport = false;
64
65  // Default to no types using fpret.
66  RealTypeUsesObjCFPRet = 0;
67
68  // Default to using the Itanium ABI.
69  CXXABI = CXXABI_Itanium;
70
71  // Default to an empty address space map.
72  AddrSpaceMap = &DefaultAddrSpaceMap;
73
74  // Default to an unknown platform name.
75  PlatformName = "unknown";
76  PlatformMinVersion = VersionTuple();
77}
78
79// Out of line virtual dtor for TargetInfo.
80TargetInfo::~TargetInfo() {}
81
82/// getTypeName - Return the user string for the specified integer type enum.
83/// For example, SignedShort -> "short".
84const char *TargetInfo::getTypeName(IntType T) {
85  switch (T) {
86  default: assert(0 && "not an integer!");
87  case SignedShort:      return "short";
88  case UnsignedShort:    return "unsigned short";
89  case SignedInt:        return "int";
90  case UnsignedInt:      return "unsigned int";
91  case SignedLong:       return "long int";
92  case UnsignedLong:     return "long unsigned int";
93  case SignedLongLong:   return "long long int";
94  case UnsignedLongLong: return "long long unsigned int";
95  }
96}
97
98/// getTypeConstantSuffix - Return the constant suffix for the specified
99/// integer type enum. For example, SignedLong -> "L".
100const char *TargetInfo::getTypeConstantSuffix(IntType T) {
101  switch (T) {
102  default: assert(0 && "not an integer!");
103  case SignedShort:
104  case SignedInt:        return "";
105  case SignedLong:       return "L";
106  case SignedLongLong:   return "LL";
107  case UnsignedShort:
108  case UnsignedInt:      return "U";
109  case UnsignedLong:     return "UL";
110  case UnsignedLongLong: return "ULL";
111  }
112}
113
114/// getTypeWidth - Return the width (in bits) of the specified integer type
115/// enum. For example, SignedInt -> getIntWidth().
116unsigned TargetInfo::getTypeWidth(IntType T) const {
117  switch (T) {
118  default: assert(0 && "not an integer!");
119  case SignedShort:
120  case UnsignedShort:    return getShortWidth();
121  case SignedInt:
122  case UnsignedInt:      return getIntWidth();
123  case SignedLong:
124  case UnsignedLong:     return getLongWidth();
125  case SignedLongLong:
126  case UnsignedLongLong: return getLongLongWidth();
127  };
128}
129
130/// getTypeAlign - Return the alignment (in bits) of the specified integer type
131/// enum. For example, SignedInt -> getIntAlign().
132unsigned TargetInfo::getTypeAlign(IntType T) const {
133  switch (T) {
134  default: assert(0 && "not an integer!");
135  case SignedShort:
136  case UnsignedShort:    return getShortAlign();
137  case SignedInt:
138  case UnsignedInt:      return getIntAlign();
139  case SignedLong:
140  case UnsignedLong:     return getLongAlign();
141  case SignedLongLong:
142  case UnsignedLongLong: return getLongLongAlign();
143  };
144}
145
146/// isTypeSigned - Return whether an integer types is signed. Returns true if
147/// the type is signed; false otherwise.
148bool TargetInfo::isTypeSigned(IntType T) {
149  switch (T) {
150  default: assert(0 && "not an integer!");
151  case SignedShort:
152  case SignedInt:
153  case SignedLong:
154  case SignedLongLong:
155    return true;
156  case UnsignedShort:
157  case UnsignedInt:
158  case UnsignedLong:
159  case UnsignedLongLong:
160    return false;
161  };
162}
163
164/// setForcedLangOptions - Set forced language options.
165/// Apply changes to the target information with respect to certain
166/// language options which change the target configuration.
167void TargetInfo::setForcedLangOptions(LangOptions &Opts) {
168  if (Opts.NoBitFieldTypeAlign)
169    UseBitFieldTypeAlignment = false;
170  if (Opts.ShortWChar)
171    WCharType = UnsignedShort;
172}
173
174//===----------------------------------------------------------------------===//
175
176
177static llvm::StringRef removeGCCRegisterPrefix(llvm::StringRef Name) {
178  if (Name[0] == '%' || Name[0] == '#')
179    Name = Name.substr(1);
180
181  return Name;
182}
183
184/// isValidGCCRegisterName - Returns whether the passed in string
185/// is a valid register name according to GCC. This is used by Sema for
186/// inline asm statements.
187bool TargetInfo::isValidGCCRegisterName(llvm::StringRef Name) const {
188  if (Name.empty())
189    return false;
190
191  const char * const *Names;
192  unsigned NumNames;
193
194  // Get rid of any register prefix.
195  Name = removeGCCRegisterPrefix(Name);
196
197  if (Name == "memory" || Name == "cc")
198    return true;
199
200  getGCCRegNames(Names, NumNames);
201
202  // If we have a number it maps to an entry in the register name array.
203  if (isdigit(Name[0])) {
204    int n;
205    if (!Name.getAsInteger(0, n))
206      return n >= 0 && (unsigned)n < NumNames;
207  }
208
209  // Check register names.
210  for (unsigned i = 0; i < NumNames; i++) {
211    if (Name == Names[i])
212      return true;
213  }
214
215  // Now check aliases.
216  const GCCRegAlias *Aliases;
217  unsigned NumAliases;
218
219  getGCCRegAliases(Aliases, NumAliases);
220  for (unsigned i = 0; i < NumAliases; i++) {
221    for (unsigned j = 0 ; j < llvm::array_lengthof(Aliases[i].Aliases); j++) {
222      if (!Aliases[i].Aliases[j])
223        break;
224      if (Aliases[i].Aliases[j] == Name)
225        return true;
226    }
227  }
228
229  return false;
230}
231
232llvm::StringRef
233TargetInfo::getNormalizedGCCRegisterName(llvm::StringRef Name) const {
234  assert(isValidGCCRegisterName(Name) && "Invalid register passed in");
235
236  // Get rid of any register prefix.
237  Name = removeGCCRegisterPrefix(Name);
238
239  const char * const *Names;
240  unsigned NumNames;
241
242  getGCCRegNames(Names, NumNames);
243
244  // First, check if we have a number.
245  if (isdigit(Name[0])) {
246    int n;
247    if (!Name.getAsInteger(0, n)) {
248      assert(n >= 0 && (unsigned)n < NumNames &&
249             "Out of bounds register number!");
250      return Names[n];
251    }
252  }
253
254  // Now check aliases.
255  const GCCRegAlias *Aliases;
256  unsigned NumAliases;
257
258  getGCCRegAliases(Aliases, NumAliases);
259  for (unsigned i = 0; i < NumAliases; i++) {
260    for (unsigned j = 0 ; j < llvm::array_lengthof(Aliases[i].Aliases); j++) {
261      if (!Aliases[i].Aliases[j])
262        break;
263      if (Aliases[i].Aliases[j] == Name)
264        return Aliases[i].Register;
265    }
266  }
267
268  return Name;
269}
270
271bool TargetInfo::validateOutputConstraint(ConstraintInfo &Info) const {
272  const char *Name = Info.getConstraintStr().c_str();
273  // An output constraint must start with '=' or '+'
274  if (*Name != '=' && *Name != '+')
275    return false;
276
277  if (*Name == '+')
278    Info.setIsReadWrite();
279
280  Name++;
281  while (*Name) {
282    switch (*Name) {
283    default:
284      if (!validateAsmConstraint(Name, Info)) {
285        // FIXME: We temporarily return false
286        // so we can add more constraints as we hit it.
287        // Eventually, an unknown constraint should just be treated as 'g'.
288        return false;
289      }
290    case '&': // early clobber.
291      break;
292    case '%': // commutative.
293      // FIXME: Check that there is a another register after this one.
294      break;
295    case 'r': // general register.
296      Info.setAllowsRegister();
297      break;
298    case 'm': // memory operand.
299    case 'o': // offsetable memory operand.
300    case 'V': // non-offsetable memory operand.
301    case '<': // autodecrement memory operand.
302    case '>': // autoincrement memory operand.
303      Info.setAllowsMemory();
304      break;
305    case 'g': // general register, memory operand or immediate integer.
306    case 'X': // any operand.
307      Info.setAllowsRegister();
308      Info.setAllowsMemory();
309      break;
310    case ',': // multiple alternative constraint.  Pass it.
311      // Handle additional optional '=' or '+' modifiers.
312      if (Name[1] == '=' || Name[1] == '+')
313        Name++;
314      break;
315    case '?': // Disparage slightly code.
316    case '!': // Disparage severely.
317      break;  // Pass them.
318    }
319
320    Name++;
321  }
322
323  return true;
324}
325
326bool TargetInfo::resolveSymbolicName(const char *&Name,
327                                     ConstraintInfo *OutputConstraints,
328                                     unsigned NumOutputs,
329                                     unsigned &Index) const {
330  assert(*Name == '[' && "Symbolic name did not start with '['");
331  Name++;
332  const char *Start = Name;
333  while (*Name && *Name != ']')
334    Name++;
335
336  if (!*Name) {
337    // Missing ']'
338    return false;
339  }
340
341  std::string SymbolicName(Start, Name - Start);
342
343  for (Index = 0; Index != NumOutputs; ++Index)
344    if (SymbolicName == OutputConstraints[Index].getName())
345      return true;
346
347  return false;
348}
349
350bool TargetInfo::validateInputConstraint(ConstraintInfo *OutputConstraints,
351                                         unsigned NumOutputs,
352                                         ConstraintInfo &Info) const {
353  const char *Name = Info.ConstraintStr.c_str();
354
355  while (*Name) {
356    switch (*Name) {
357    default:
358      // Check if we have a matching constraint
359      if (*Name >= '0' && *Name <= '9') {
360        unsigned i = *Name - '0';
361
362        // Check if matching constraint is out of bounds.
363        if (i >= NumOutputs)
364          return false;
365
366        // A number must refer to an output only operand.
367        if (OutputConstraints[i].isReadWrite())
368          return false;
369
370        // If the constraint is already tied, it must be tied to the
371        // same operand referenced to by the number.
372        if (Info.hasTiedOperand() && Info.getTiedOperand() != i)
373          return false;
374
375        // The constraint should have the same info as the respective
376        // output constraint.
377        Info.setTiedOperand(i, OutputConstraints[i]);
378      } else if (!validateAsmConstraint(Name, Info)) {
379        // FIXME: This error return is in place temporarily so we can
380        // add more constraints as we hit it.  Eventually, an unknown
381        // constraint should just be treated as 'g'.
382        return false;
383      }
384      break;
385    case '[': {
386      unsigned Index = 0;
387      if (!resolveSymbolicName(Name, OutputConstraints, NumOutputs, Index))
388        return false;
389
390      // If the constraint is already tied, it must be tied to the
391      // same operand referenced to by the number.
392      if (Info.hasTiedOperand() && Info.getTiedOperand() != Index)
393        return false;
394
395      Info.setTiedOperand(Index, OutputConstraints[Index]);
396      break;
397    }
398    case '%': // commutative
399      // FIXME: Fail if % is used with the last operand.
400      break;
401    case 'i': // immediate integer.
402    case 'n': // immediate integer with a known value.
403      break;
404    case 'I':  // Various constant constraints with target-specific meanings.
405    case 'J':
406    case 'K':
407    case 'L':
408    case 'M':
409    case 'N':
410    case 'O':
411    case 'P':
412      break;
413    case 'r': // general register.
414      Info.setAllowsRegister();
415      break;
416    case 'm': // memory operand.
417    case 'o': // offsettable memory operand.
418    case 'V': // non-offsettable memory operand.
419    case '<': // autodecrement memory operand.
420    case '>': // autoincrement memory operand.
421      Info.setAllowsMemory();
422      break;
423    case 'g': // general register, memory operand or immediate integer.
424    case 'X': // any operand.
425      Info.setAllowsRegister();
426      Info.setAllowsMemory();
427      break;
428    case 'E': // immediate floating point.
429    case 'F': // immediate floating point.
430    case 'p': // address operand.
431      break;
432    case ',': // multiple alternative constraint.  Ignore comma.
433      break;
434    case '?': // Disparage slightly code.
435    case '!': // Disparage severely.
436      break;  // Pass them.
437    }
438
439    Name++;
440  }
441
442  return true;
443}
444