TargetInfo.cpp revision 201361 
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/LangOptions.h"
16#include "llvm/ADT/APFloat.h"
17#include "llvm/ADT/STLExtras.h"
18#include <cstdlib>
19using namespace clang;
20
21// TargetInfo Constructor.
22TargetInfo::TargetInfo(const std::string &T) : Triple(T) {
23  // Set defaults.  Defaults are set for a 32-bit RISC platform,
24  // like PPC or SPARC.
25  // These should be overridden by concrete targets as needed.
26  TLSSupported = true;
27  PointerWidth = PointerAlign = 32;
28  IntWidth = IntAlign = 32;
29  LongWidth = LongAlign = 32;
30  LongLongWidth = LongLongAlign = 64;
31  FloatWidth = 32;
32  FloatAlign = 32;
33  DoubleWidth = 64;
34  DoubleAlign = 64;
35  LongDoubleWidth = 64;
36  LongDoubleAlign = 64;
37  SizeType = UnsignedLong;
38  PtrDiffType = SignedLong;
39  IntMaxType = SignedLongLong;
40  UIntMaxType = UnsignedLongLong;
41  IntPtrType = SignedLong;
42  WCharType = SignedInt;
43  WIntType = SignedInt;
44  Char16Type = UnsignedShort;
45  Char32Type = UnsignedInt;
46  Int64Type = SignedLongLong;
47  SigAtomicType = SignedInt;
48  FloatFormat = &llvm::APFloat::IEEEsingle;
49  DoubleFormat = &llvm::APFloat::IEEEdouble;
50  LongDoubleFormat = &llvm::APFloat::IEEEdouble;
51  DescriptionString = "E-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-"
52                      "i64:64:64-f32:32:32-f64:64:64-n32";
53  UserLabelPrefix = "_";
54}
55
56// Out of line virtual dtor for TargetInfo.
57TargetInfo::~TargetInfo() {}
58
59/// getTypeName - Return the user string for the specified integer type enum.
60/// For example, SignedShort -> "short".
61const char *TargetInfo::getTypeName(IntType T) {
62  switch (T) {
63  default: assert(0 && "not an integer!");
64  case SignedShort:      return "short";
65  case UnsignedShort:    return "unsigned short";
66  case SignedInt:        return "int";
67  case UnsignedInt:      return "unsigned int";
68  case SignedLong:       return "long int";
69  case UnsignedLong:     return "long unsigned int";
70  case SignedLongLong:   return "long long int";
71  case UnsignedLongLong: return "long long unsigned int";
72  }
73}
74
75/// getTypeConstantSuffix - Return the constant suffix for the specified
76/// integer type enum. For example, SignedLong -> "L".
77const char *TargetInfo::getTypeConstantSuffix(IntType T) {
78  switch (T) {
79  default: assert(0 && "not an integer!");
80  case SignedShort:
81  case SignedInt:        return "";
82  case SignedLong:       return "L";
83  case SignedLongLong:   return "LL";
84  case UnsignedShort:
85  case UnsignedInt:      return "U";
86  case UnsignedLong:     return "UL";
87  case UnsignedLongLong: return "ULL";
88  }
89}
90
91/// getTypeWidth - Return the width (in bits) of the specified integer type
92/// enum. For example, SignedInt -> getIntWidth().
93unsigned TargetInfo::getTypeWidth(IntType T) const {
94  switch (T) {
95  default: assert(0 && "not an integer!");
96  case SignedShort:
97  case UnsignedShort:    return getShortWidth();
98  case SignedInt:
99  case UnsignedInt:      return getIntWidth();
100  case SignedLong:
101  case UnsignedLong:     return getLongWidth();
102  case SignedLongLong:
103  case UnsignedLongLong: return getLongLongWidth();
104  };
105}
106
107/// getTypeAlign - Return the alignment (in bits) of the specified integer type
108/// enum. For example, SignedInt -> getIntAlign().
109unsigned TargetInfo::getTypeAlign(IntType T) const {
110  switch (T) {
111  default: assert(0 && "not an integer!");
112  case SignedShort:
113  case UnsignedShort:    return getShortAlign();
114  case SignedInt:
115  case UnsignedInt:      return getIntAlign();
116  case SignedLong:
117  case UnsignedLong:     return getLongAlign();
118  case SignedLongLong:
119  case UnsignedLongLong: return getLongLongAlign();
120  };
121}
122
123/// isTypeSigned - Return whether an integer types is signed. Returns true if
124/// the type is signed; false otherwise.
125bool TargetInfo::isTypeSigned(IntType T) const {
126  switch (T) {
127  default: assert(0 && "not an integer!");
128  case SignedShort:
129  case SignedInt:
130  case SignedLong:
131  case SignedLongLong:
132    return true;
133  case UnsignedShort:
134  case UnsignedInt:
135  case UnsignedLong:
136  case UnsignedLongLong:
137    return false;
138  };
139}
140
141/// setForcedLangOptions - Set forced language options.
142/// Apply changes to the target information with respect to certain
143/// language options which change the target configuration.
144void TargetInfo::setForcedLangOptions(LangOptions &Opts) {
145  if (Opts.ShortWChar) {
146    WCharType = UnsignedShort;
147  }
148}
149
150//===----------------------------------------------------------------------===//
151
152
153static void removeGCCRegisterPrefix(const char *&Name) {
154  if (Name[0] == '%' || Name[0] == '#')
155    Name++;
156}
157
158/// isValidGCCRegisterName - Returns whether the passed in string
159/// is a valid register name according to GCC. This is used by Sema for
160/// inline asm statements.
161bool TargetInfo::isValidGCCRegisterName(const char *Name) const {
162  const char * const *Names;
163  unsigned NumNames;
164
165  // Get rid of any register prefix.
166  removeGCCRegisterPrefix(Name);
167
168
169  if (strcmp(Name, "memory") == 0 ||
170      strcmp(Name, "cc") == 0)
171    return true;
172
173  getGCCRegNames(Names, NumNames);
174
175  // If we have a number it maps to an entry in the register name array.
176  if (isdigit(Name[0])) {
177    char *End;
178    int n = (int)strtol(Name, &End, 0);
179    if (*End == 0)
180      return n >= 0 && (unsigned)n < NumNames;
181  }
182
183  // Check register names.
184  for (unsigned i = 0; i < NumNames; i++) {
185    if (strcmp(Name, Names[i]) == 0)
186      return true;
187  }
188
189  // Now check aliases.
190  const GCCRegAlias *Aliases;
191  unsigned NumAliases;
192
193  getGCCRegAliases(Aliases, NumAliases);
194  for (unsigned i = 0; i < NumAliases; i++) {
195    for (unsigned j = 0 ; j < llvm::array_lengthof(Aliases[i].Aliases); j++) {
196      if (!Aliases[i].Aliases[j])
197        break;
198      if (strcmp(Aliases[i].Aliases[j], Name) == 0)
199        return true;
200    }
201  }
202
203  return false;
204}
205
206const char *TargetInfo::getNormalizedGCCRegisterName(const char *Name) const {
207  assert(isValidGCCRegisterName(Name) && "Invalid register passed in");
208
209  removeGCCRegisterPrefix(Name);
210
211  const char * const *Names;
212  unsigned NumNames;
213
214  getGCCRegNames(Names, NumNames);
215
216  // First, check if we have a number.
217  if (isdigit(Name[0])) {
218    char *End;
219    int n = (int)strtol(Name, &End, 0);
220    if (*End == 0) {
221      assert(n >= 0 && (unsigned)n < NumNames &&
222             "Out of bounds register number!");
223      return Names[n];
224    }
225  }
226
227  // Now check aliases.
228  const GCCRegAlias *Aliases;
229  unsigned NumAliases;
230
231  getGCCRegAliases(Aliases, NumAliases);
232  for (unsigned i = 0; i < NumAliases; i++) {
233    for (unsigned j = 0 ; j < llvm::array_lengthof(Aliases[i].Aliases); j++) {
234      if (!Aliases[i].Aliases[j])
235        break;
236      if (strcmp(Aliases[i].Aliases[j], Name) == 0)
237        return Aliases[i].Register;
238    }
239  }
240
241  return Name;
242}
243
244bool TargetInfo::validateOutputConstraint(ConstraintInfo &Info) const {
245  const char *Name = Info.getConstraintStr().c_str();
246  // An output constraint must start with '=' or '+'
247  if (*Name != '=' && *Name != '+')
248    return false;
249
250  if (*Name == '+')
251    Info.setIsReadWrite();
252
253  Name++;
254  while (*Name) {
255    switch (*Name) {
256    default:
257      if (!validateAsmConstraint(Name, Info)) {
258        // FIXME: We temporarily return false
259        // so we can add more constraints as we hit it.
260        // Eventually, an unknown constraint should just be treated as 'g'.
261        return false;
262      }
263    case '&': // early clobber.
264      break;
265    case '%': // commutative.
266      // FIXME: Check that there is a another register after this one.
267      break;
268    case 'r': // general register.
269      Info.setAllowsRegister();
270      break;
271    case 'm': // memory operand.
272      Info.setAllowsMemory();
273      break;
274    case 'g': // general register, memory operand or immediate integer.
275    case 'X': // any operand.
276      Info.setAllowsRegister();
277      Info.setAllowsMemory();
278      break;
279    }
280
281    Name++;
282  }
283
284  return true;
285}
286
287bool TargetInfo::resolveSymbolicName(const char *&Name,
288                                     ConstraintInfo *OutputConstraints,
289                                     unsigned NumOutputs,
290                                     unsigned &Index) const {
291  assert(*Name == '[' && "Symbolic name did not start with '['");
292  Name++;
293  const char *Start = Name;
294  while (*Name && *Name != ']')
295    Name++;
296
297  if (!*Name) {
298    // Missing ']'
299    return false;
300  }
301
302  std::string SymbolicName(Start, Name - Start);
303
304  for (Index = 0; Index != NumOutputs; ++Index)
305    if (SymbolicName == OutputConstraints[Index].getName())
306      return true;
307
308  return false;
309}
310
311bool TargetInfo::validateInputConstraint(ConstraintInfo *OutputConstraints,
312                                         unsigned NumOutputs,
313                                         ConstraintInfo &Info) const {
314  const char *Name = Info.ConstraintStr.c_str();
315
316  while (*Name) {
317    switch (*Name) {
318    default:
319      // Check if we have a matching constraint
320      if (*Name >= '0' && *Name <= '9') {
321        unsigned i = *Name - '0';
322
323        // Check if matching constraint is out of bounds.
324        if (i >= NumOutputs)
325          return false;
326
327        // The constraint should have the same info as the respective
328        // output constraint.
329        Info.setTiedOperand(i, OutputConstraints[i]);
330      } else if (!validateAsmConstraint(Name, Info)) {
331        // FIXME: This error return is in place temporarily so we can
332        // add more constraints as we hit it.  Eventually, an unknown
333        // constraint should just be treated as 'g'.
334        return false;
335      }
336      break;
337    case '[': {
338      unsigned Index = 0;
339      if (!resolveSymbolicName(Name, OutputConstraints, NumOutputs, Index))
340        return false;
341
342      break;
343    }
344    case '%': // commutative
345      // FIXME: Fail if % is used with the last operand.
346      break;
347    case 'i': // immediate integer.
348    case 'n': // immediate integer with a known value.
349      break;
350    case 'I':  // Various constant constraints with target-specific meanings.
351    case 'J':
352    case 'K':
353    case 'L':
354    case 'M':
355    case 'N':
356    case 'O':
357    case 'P':
358      break;
359    case 'r': // general register.
360      Info.setAllowsRegister();
361      break;
362    case 'm': // memory operand.
363    case 'o': // offsettable memory operand
364    case 'V': // non-offsettable memory operand
365      Info.setAllowsMemory();
366      break;
367    case 'g': // general register, memory operand or immediate integer.
368    case 'X': // any operand.
369      Info.setAllowsRegister();
370      Info.setAllowsMemory();
371      break;
372    }
373
374    Name++;
375  }
376
377  return true;
378}
379