TargetInfo.cpp revision 193326 
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 "llvm/ADT/APFloat.h"
16#include "llvm/ADT/STLExtras.h"
17#include <cstdlib>
18using namespace clang;
19
20// TargetInfo Constructor.
21TargetInfo::TargetInfo(const std::string &T) : Triple(T) {
22  // Set defaults.  Defaults are set for a 32-bit RISC platform,
23  // like PPC or SPARC.
24  // These should be overridden by concrete targets as needed.
25  CharIsSigned = true;
26  TLSSupported = true;
27  PointerWidth = PointerAlign = 32;
28  WCharWidth = WCharAlign = 32;
29  IntWidth = IntAlign = 32;
30  LongWidth = LongAlign = 32;
31  LongLongWidth = LongLongAlign = 64;
32  FloatWidth = 32;
33  FloatAlign = 32;
34  DoubleWidth = 64;
35  DoubleAlign = 64;
36  LongDoubleWidth = 64;
37  LongDoubleAlign = 64;
38  IntMaxTWidth = 64;
39  SizeType = UnsignedLong;
40  PtrDiffType = SignedLong;
41  IntMaxType = SignedLongLong;
42  UIntMaxType = UnsignedLongLong;
43  IntPtrType = SignedLong;
44  WCharType = SignedInt;
45  FloatFormat = &llvm::APFloat::IEEEsingle;
46  DoubleFormat = &llvm::APFloat::IEEEdouble;
47  LongDoubleFormat = &llvm::APFloat::IEEEdouble;
48  DescriptionString = "E-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-"
49                      "i64:64:64-f32:32:32-f64:64:64";
50  UserLabelPrefix = "_";
51}
52
53// Out of line virtual dtor for TargetInfo.
54TargetInfo::~TargetInfo() {}
55
56/// getTypeName - Return the user string for the specified integer type enum.
57/// For example, SignedShort -> "short".
58const char *TargetInfo::getTypeName(IntType T) {
59  switch (T) {
60  default: assert(0 && "not an integer!");
61  case SignedShort:      return "short";
62  case UnsignedShort:    return "unsigned short";
63  case SignedInt:        return "int";
64  case UnsignedInt:      return "unsigned int";
65  case SignedLong:       return "long int";
66  case UnsignedLong:     return "long unsigned int";
67  case SignedLongLong:   return "long long int";
68  case UnsignedLongLong: return "long long unsigned int";
69  }
70}
71
72//===----------------------------------------------------------------------===//
73
74
75static void removeGCCRegisterPrefix(const char *&Name) {
76  if (Name[0] == '%' || Name[0] == '#')
77    Name++;
78}
79
80/// isValidGCCRegisterName - Returns whether the passed in string
81/// is a valid register name according to GCC. This is used by Sema for
82/// inline asm statements.
83bool TargetInfo::isValidGCCRegisterName(const char *Name) const {
84  const char * const *Names;
85  unsigned NumNames;
86
87  // Get rid of any register prefix.
88  removeGCCRegisterPrefix(Name);
89
90
91  if (strcmp(Name, "memory") == 0 ||
92      strcmp(Name, "cc") == 0)
93    return true;
94
95  getGCCRegNames(Names, NumNames);
96
97  // If we have a number it maps to an entry in the register name array.
98  if (isdigit(Name[0])) {
99    char *End;
100    int n = (int)strtol(Name, &End, 0);
101    if (*End == 0)
102      return n >= 0 && (unsigned)n < NumNames;
103  }
104
105  // Check register names.
106  for (unsigned i = 0; i < NumNames; i++) {
107    if (strcmp(Name, Names[i]) == 0)
108      return true;
109  }
110
111  // Now check aliases.
112  const GCCRegAlias *Aliases;
113  unsigned NumAliases;
114
115  getGCCRegAliases(Aliases, NumAliases);
116  for (unsigned i = 0; i < NumAliases; i++) {
117    for (unsigned j = 0 ; j < llvm::array_lengthof(Aliases[i].Aliases); j++) {
118      if (!Aliases[i].Aliases[j])
119        break;
120      if (strcmp(Aliases[i].Aliases[j], Name) == 0)
121        return true;
122    }
123  }
124
125  return false;
126}
127
128const char *TargetInfo::getNormalizedGCCRegisterName(const char *Name) const {
129  assert(isValidGCCRegisterName(Name) && "Invalid register passed in");
130
131  removeGCCRegisterPrefix(Name);
132
133  const char * const *Names;
134  unsigned NumNames;
135
136  getGCCRegNames(Names, NumNames);
137
138  // First, check if we have a number.
139  if (isdigit(Name[0])) {
140    char *End;
141    int n = (int)strtol(Name, &End, 0);
142    if (*End == 0) {
143      assert(n >= 0 && (unsigned)n < NumNames &&
144             "Out of bounds register number!");
145      return Names[n];
146    }
147  }
148
149  // Now check aliases.
150  const GCCRegAlias *Aliases;
151  unsigned NumAliases;
152
153  getGCCRegAliases(Aliases, NumAliases);
154  for (unsigned i = 0; i < NumAliases; i++) {
155    for (unsigned j = 0 ; j < llvm::array_lengthof(Aliases[i].Aliases); j++) {
156      if (!Aliases[i].Aliases[j])
157        break;
158      if (strcmp(Aliases[i].Aliases[j], Name) == 0)
159        return Aliases[i].Register;
160    }
161  }
162
163  return Name;
164}
165
166bool TargetInfo::validateOutputConstraint(ConstraintInfo &Info) const {
167  const char *Name = Info.getConstraintStr().c_str();
168  // An output constraint must start with '=' or '+'
169  if (*Name != '=' && *Name != '+')
170    return false;
171
172  if (*Name == '+')
173    Info.setIsReadWrite();
174
175  Name++;
176  while (*Name) {
177    switch (*Name) {
178    default:
179      if (!validateAsmConstraint(Name, Info)) {
180        // FIXME: We temporarily return false
181        // so we can add more constraints as we hit it.
182        // Eventually, an unknown constraint should just be treated as 'g'.
183        return false;
184      }
185    case '&': // early clobber.
186      break;
187    case 'r': // general register.
188      Info.setAllowsRegister();
189      break;
190    case 'm': // memory operand.
191      Info.setAllowsMemory();
192      break;
193    case 'g': // general register, memory operand or immediate integer.
194    case 'X': // any operand.
195      Info.setAllowsRegister();
196      Info.setAllowsMemory();
197      break;
198    }
199
200    Name++;
201  }
202
203  return true;
204}
205
206bool TargetInfo::resolveSymbolicName(const char *&Name,
207                                     ConstraintInfo *OutputConstraints,
208                                     unsigned NumOutputs,
209                                     unsigned &Index) const {
210  assert(*Name == '[' && "Symbolic name did not start with '['");
211  Name++;
212  const char *Start = Name;
213  while (*Name && *Name != ']')
214    Name++;
215
216  if (!*Name) {
217    // Missing ']'
218    return false;
219  }
220
221  std::string SymbolicName(Start, Name - Start);
222
223  for (Index = 0; Index != NumOutputs; ++Index)
224    if (SymbolicName == OutputConstraints[Index].getName())
225      return true;
226
227  return false;
228}
229
230bool TargetInfo::validateInputConstraint(ConstraintInfo *OutputConstraints,
231                                         unsigned NumOutputs,
232                                         ConstraintInfo &Info) const {
233  const char *Name = Info.ConstraintStr.c_str();
234
235  while (*Name) {
236    switch (*Name) {
237    default:
238      // Check if we have a matching constraint
239      if (*Name >= '0' && *Name <= '9') {
240        unsigned i = *Name - '0';
241
242        // Check if matching constraint is out of bounds.
243        if (i >= NumOutputs)
244          return false;
245
246        // The constraint should have the same info as the respective
247        // output constraint.
248        Info.setTiedOperand(i, OutputConstraints[i]);
249      } else if (!validateAsmConstraint(Name, Info)) {
250        // FIXME: This error return is in place temporarily so we can
251        // add more constraints as we hit it.  Eventually, an unknown
252        // constraint should just be treated as 'g'.
253        return false;
254      }
255      break;
256    case '[': {
257      unsigned Index = 0;
258      if (!resolveSymbolicName(Name, OutputConstraints, NumOutputs, Index))
259        return false;
260
261      break;
262    }
263    case '%': // commutative
264      // FIXME: Fail if % is used with the last operand.
265      break;
266    case 'i': // immediate integer.
267    case 'n': // immediate integer with a known value.
268      break;
269    case 'I':  // Various constant constraints with target-specific meanings.
270    case 'J':
271    case 'K':
272    case 'L':
273    case 'M':
274    case 'N':
275    case 'O':
276    case 'P':
277      break;
278    case 'r': // general register.
279      Info.setAllowsRegister();
280      break;
281    case 'm': // memory operand.
282      Info.setAllowsMemory();
283      break;
284    case 'g': // general register, memory operand or immediate integer.
285    case 'X': // any operand.
286      Info.setAllowsRegister();
287      Info.setAllowsMemory();
288      break;
289    }
290
291    Name++;
292  }
293
294  return true;
295}
296