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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 "llvm/Support/ErrorHandling.h"
20 #include <cctype>
21 #include <cstdlib>
22 using namespace clang;
23 
24 static const LangAS::Map DefaultAddrSpaceMap = { 0 };
25 
26 // TargetInfo Constructor.
TargetInfo(const std::string & T)27 TargetInfo::TargetInfo(const std::string &T) : 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   HalfWidth = 16;
40   HalfAlign = 16;
41   FloatWidth = 32;
42   FloatAlign = 32;
43   DoubleWidth = 64;
44   DoubleAlign = 64;
45   LongDoubleWidth = 64;
46   LongDoubleAlign = 64;
47   LargeArrayMinWidth = 0;
48   LargeArrayAlign = 0;
49   MaxAtomicPromoteWidth = MaxAtomicInlineWidth = 0;
50   MaxVectorAlign = 0;
51   SizeType = UnsignedLong;
52   PtrDiffType = SignedLong;
53   IntMaxType = SignedLongLong;
54   UIntMaxType = UnsignedLongLong;
55   IntPtrType = SignedLong;
56   WCharType = SignedInt;
57   WIntType = SignedInt;
58   Char16Type = UnsignedShort;
59   Char32Type = UnsignedInt;
60   Int64Type = SignedLongLong;
61   SigAtomicType = SignedInt;
62   UseSignedCharForObjCBool = true;
63   UseBitFieldTypeAlignment = true;
64   UseZeroLengthBitfieldAlignment = false;
65   ZeroLengthBitfieldBoundary = 0;
66   HalfFormat = &llvm::APFloat::IEEEhalf;
67   FloatFormat = &llvm::APFloat::IEEEsingle;
68   DoubleFormat = &llvm::APFloat::IEEEdouble;
69   LongDoubleFormat = &llvm::APFloat::IEEEdouble;
70   DescriptionString = "E-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-"
71                       "i64:64:64-f32:32:32-f64:64:64-n32";
72   UserLabelPrefix = "_";
73   MCountName = "mcount";
74   RegParmMax = 0;
75   SSERegParmMax = 0;
76   HasAlignMac68kSupport = false;
77 
78   // Default to no types using fpret.
79   RealTypeUsesObjCFPRet = 0;
80 
81   // Default to not using fp2ret for __Complex long double
82   ComplexLongDoubleUsesFP2Ret = false;
83 
84   // Default to using the Itanium ABI.
85   CXXABI = CXXABI_Itanium;
86 
87   // Default to an empty address space map.
88   AddrSpaceMap = &DefaultAddrSpaceMap;
89 
90   // Default to an unknown platform name.
91   PlatformName = "unknown";
92   PlatformMinVersion = VersionTuple();
93 }
94 
95 // Out of line virtual dtor for TargetInfo.
~TargetInfo()96 TargetInfo::~TargetInfo() {}
97 
98 /// getTypeName - Return the user string for the specified integer type enum.
99 /// For example, SignedShort -> "short".
getTypeName(IntType T)100 const char *TargetInfo::getTypeName(IntType T) {
101   switch (T) {
102   default: llvm_unreachable("not an integer!");
103   case SignedShort:      return "short";
104   case UnsignedShort:    return "unsigned short";
105   case SignedInt:        return "int";
106   case UnsignedInt:      return "unsigned int";
107   case SignedLong:       return "long int";
108   case UnsignedLong:     return "long unsigned int";
109   case SignedLongLong:   return "long long int";
110   case UnsignedLongLong: return "long long unsigned int";
111   }
112 }
113 
114 /// getTypeConstantSuffix - Return the constant suffix for the specified
115 /// integer type enum. For example, SignedLong -> "L".
getTypeConstantSuffix(IntType T)116 const char *TargetInfo::getTypeConstantSuffix(IntType T) {
117   switch (T) {
118   default: llvm_unreachable("not an integer!");
119   case SignedShort:
120   case SignedInt:        return "";
121   case SignedLong:       return "L";
122   case SignedLongLong:   return "LL";
123   case UnsignedShort:
124   case UnsignedInt:      return "U";
125   case UnsignedLong:     return "UL";
126   case UnsignedLongLong: return "ULL";
127   }
128 }
129 
130 /// getTypeWidth - Return the width (in bits) of the specified integer type
131 /// enum. For example, SignedInt -> getIntWidth().
getTypeWidth(IntType T) const132 unsigned TargetInfo::getTypeWidth(IntType T) const {
133   switch (T) {
134   default: llvm_unreachable("not an integer!");
135   case SignedShort:
136   case UnsignedShort:    return getShortWidth();
137   case SignedInt:
138   case UnsignedInt:      return getIntWidth();
139   case SignedLong:
140   case UnsignedLong:     return getLongWidth();
141   case SignedLongLong:
142   case UnsignedLongLong: return getLongLongWidth();
143   };
144 }
145 
146 /// getTypeAlign - Return the alignment (in bits) of the specified integer type
147 /// enum. For example, SignedInt -> getIntAlign().
getTypeAlign(IntType T) const148 unsigned TargetInfo::getTypeAlign(IntType T) const {
149   switch (T) {
150   default: llvm_unreachable("not an integer!");
151   case SignedShort:
152   case UnsignedShort:    return getShortAlign();
153   case SignedInt:
154   case UnsignedInt:      return getIntAlign();
155   case SignedLong:
156   case UnsignedLong:     return getLongAlign();
157   case SignedLongLong:
158   case UnsignedLongLong: return getLongLongAlign();
159   };
160 }
161 
162 /// isTypeSigned - Return whether an integer types is signed. Returns true if
163 /// the type is signed; false otherwise.
isTypeSigned(IntType T)164 bool TargetInfo::isTypeSigned(IntType T) {
165   switch (T) {
166   default: llvm_unreachable("not an integer!");
167   case SignedShort:
168   case SignedInt:
169   case SignedLong:
170   case SignedLongLong:
171     return true;
172   case UnsignedShort:
173   case UnsignedInt:
174   case UnsignedLong:
175   case UnsignedLongLong:
176     return false;
177   };
178 }
179 
180 /// setForcedLangOptions - Set forced language options.
181 /// Apply changes to the target information with respect to certain
182 /// language options which change the target configuration.
setForcedLangOptions(LangOptions & Opts)183 void TargetInfo::setForcedLangOptions(LangOptions &Opts) {
184   if (Opts.NoBitFieldTypeAlign)
185     UseBitFieldTypeAlignment = false;
186   if (Opts.ShortWChar)
187     WCharType = UnsignedShort;
188 }
189 
190 //===----------------------------------------------------------------------===//
191 
192 
removeGCCRegisterPrefix(StringRef Name)193 static StringRef removeGCCRegisterPrefix(StringRef Name) {
194   if (Name[0] == '%' || Name[0] == '#')
195     Name = Name.substr(1);
196 
197   return Name;
198 }
199 
200 /// isValidClobber - Returns whether the passed in string is
201 /// a valid clobber in an inline asm statement. This is used by
202 /// Sema.
isValidClobber(StringRef Name) const203 bool TargetInfo::isValidClobber(StringRef Name) const {
204   return (isValidGCCRegisterName(Name) ||
205 	  Name == "memory" || Name == "cc");
206 }
207 
208 /// isValidGCCRegisterName - Returns whether the passed in string
209 /// is a valid register name according to GCC. This is used by Sema for
210 /// inline asm statements.
isValidGCCRegisterName(StringRef Name) const211 bool TargetInfo::isValidGCCRegisterName(StringRef Name) const {
212   if (Name.empty())
213     return false;
214 
215   const char * const *Names;
216   unsigned NumNames;
217 
218   // Get rid of any register prefix.
219   Name = removeGCCRegisterPrefix(Name);
220 
221   getGCCRegNames(Names, NumNames);
222 
223   // If we have a number it maps to an entry in the register name array.
224   if (isdigit(Name[0])) {
225     int n;
226     if (!Name.getAsInteger(0, n))
227       return n >= 0 && (unsigned)n < NumNames;
228   }
229 
230   // Check register names.
231   for (unsigned i = 0; i < NumNames; i++) {
232     if (Name == Names[i])
233       return true;
234   }
235 
236   // Check any additional names that we have.
237   const AddlRegName *AddlNames;
238   unsigned NumAddlNames;
239   getGCCAddlRegNames(AddlNames, NumAddlNames);
240   for (unsigned i = 0; i < NumAddlNames; i++)
241     for (unsigned j = 0; j < llvm::array_lengthof(AddlNames[i].Names); j++) {
242       if (!AddlNames[i].Names[j])
243 	break;
244       // Make sure the register that the additional name is for is within
245       // the bounds of the register names from above.
246       if (AddlNames[i].Names[j] == Name && AddlNames[i].RegNum < NumNames)
247 	return true;
248   }
249 
250   // Now check aliases.
251   const GCCRegAlias *Aliases;
252   unsigned NumAliases;
253 
254   getGCCRegAliases(Aliases, NumAliases);
255   for (unsigned i = 0; i < NumAliases; i++) {
256     for (unsigned j = 0 ; j < llvm::array_lengthof(Aliases[i].Aliases); j++) {
257       if (!Aliases[i].Aliases[j])
258         break;
259       if (Aliases[i].Aliases[j] == Name)
260         return true;
261     }
262   }
263 
264   return false;
265 }
266 
267 StringRef
getNormalizedGCCRegisterName(StringRef Name) const268 TargetInfo::getNormalizedGCCRegisterName(StringRef Name) const {
269   assert(isValidGCCRegisterName(Name) && "Invalid register passed in");
270 
271   // Get rid of any register prefix.
272   Name = removeGCCRegisterPrefix(Name);
273 
274   const char * const *Names;
275   unsigned NumNames;
276 
277   getGCCRegNames(Names, NumNames);
278 
279   // First, check if we have a number.
280   if (isdigit(Name[0])) {
281     int n;
282     if (!Name.getAsInteger(0, n)) {
283       assert(n >= 0 && (unsigned)n < NumNames &&
284              "Out of bounds register number!");
285       return Names[n];
286     }
287   }
288 
289   // Check any additional names that we have.
290   const AddlRegName *AddlNames;
291   unsigned NumAddlNames;
292   getGCCAddlRegNames(AddlNames, NumAddlNames);
293   for (unsigned i = 0; i < NumAddlNames; i++)
294     for (unsigned j = 0; j < llvm::array_lengthof(AddlNames[i].Names); j++) {
295       if (!AddlNames[i].Names[j])
296 	break;
297       // Make sure the register that the additional name is for is within
298       // the bounds of the register names from above.
299       if (AddlNames[i].Names[j] == Name && AddlNames[i].RegNum < NumNames)
300 	return Name;
301     }
302 
303   // Now check aliases.
304   const GCCRegAlias *Aliases;
305   unsigned NumAliases;
306 
307   getGCCRegAliases(Aliases, NumAliases);
308   for (unsigned i = 0; i < NumAliases; i++) {
309     for (unsigned j = 0 ; j < llvm::array_lengthof(Aliases[i].Aliases); j++) {
310       if (!Aliases[i].Aliases[j])
311         break;
312       if (Aliases[i].Aliases[j] == Name)
313         return Aliases[i].Register;
314     }
315   }
316 
317   return Name;
318 }
319 
validateOutputConstraint(ConstraintInfo & Info) const320 bool TargetInfo::validateOutputConstraint(ConstraintInfo &Info) const {
321   const char *Name = Info.getConstraintStr().c_str();
322   // An output constraint must start with '=' or '+'
323   if (*Name != '=' && *Name != '+')
324     return false;
325 
326   if (*Name == '+')
327     Info.setIsReadWrite();
328 
329   Name++;
330   while (*Name) {
331     switch (*Name) {
332     default:
333       if (!validateAsmConstraint(Name, Info)) {
334         // FIXME: We temporarily return false
335         // so we can add more constraints as we hit it.
336         // Eventually, an unknown constraint should just be treated as 'g'.
337         return false;
338       }
339     case '&': // early clobber.
340       break;
341     case '%': // commutative.
342       // FIXME: Check that there is a another register after this one.
343       break;
344     case 'r': // general register.
345       Info.setAllowsRegister();
346       break;
347     case 'm': // memory operand.
348     case 'o': // offsetable memory operand.
349     case 'V': // non-offsetable memory operand.
350     case '<': // autodecrement memory operand.
351     case '>': // autoincrement memory operand.
352       Info.setAllowsMemory();
353       break;
354     case 'g': // general register, memory operand or immediate integer.
355     case 'X': // any operand.
356       Info.setAllowsRegister();
357       Info.setAllowsMemory();
358       break;
359     case ',': // multiple alternative constraint.  Pass it.
360       // Handle additional optional '=' or '+' modifiers.
361       if (Name[1] == '=' || Name[1] == '+')
362         Name++;
363       break;
364     case '?': // Disparage slightly code.
365     case '!': // Disparage severely.
366       break;  // Pass them.
367     }
368 
369     Name++;
370   }
371 
372   return true;
373 }
374 
resolveSymbolicName(const char * & Name,ConstraintInfo * OutputConstraints,unsigned NumOutputs,unsigned & Index) const375 bool TargetInfo::resolveSymbolicName(const char *&Name,
376                                      ConstraintInfo *OutputConstraints,
377                                      unsigned NumOutputs,
378                                      unsigned &Index) const {
379   assert(*Name == '[' && "Symbolic name did not start with '['");
380   Name++;
381   const char *Start = Name;
382   while (*Name && *Name != ']')
383     Name++;
384 
385   if (!*Name) {
386     // Missing ']'
387     return false;
388   }
389 
390   std::string SymbolicName(Start, Name - Start);
391 
392   for (Index = 0; Index != NumOutputs; ++Index)
393     if (SymbolicName == OutputConstraints[Index].getName())
394       return true;
395 
396   return false;
397 }
398 
validateInputConstraint(ConstraintInfo * OutputConstraints,unsigned NumOutputs,ConstraintInfo & Info) const399 bool TargetInfo::validateInputConstraint(ConstraintInfo *OutputConstraints,
400                                          unsigned NumOutputs,
401                                          ConstraintInfo &Info) const {
402   const char *Name = Info.ConstraintStr.c_str();
403 
404   while (*Name) {
405     switch (*Name) {
406     default:
407       // Check if we have a matching constraint
408       if (*Name >= '0' && *Name <= '9') {
409         unsigned i = *Name - '0';
410 
411         // Check if matching constraint is out of bounds.
412         if (i >= NumOutputs)
413           return false;
414 
415         // A number must refer to an output only operand.
416         if (OutputConstraints[i].isReadWrite())
417           return false;
418 
419         // If the constraint is already tied, it must be tied to the
420         // same operand referenced to by the number.
421         if (Info.hasTiedOperand() && Info.getTiedOperand() != i)
422           return false;
423 
424         // The constraint should have the same info as the respective
425         // output constraint.
426         Info.setTiedOperand(i, OutputConstraints[i]);
427       } else if (!validateAsmConstraint(Name, Info)) {
428         // FIXME: This error return is in place temporarily so we can
429         // add more constraints as we hit it.  Eventually, an unknown
430         // constraint should just be treated as 'g'.
431         return false;
432       }
433       break;
434     case '[': {
435       unsigned Index = 0;
436       if (!resolveSymbolicName(Name, OutputConstraints, NumOutputs, Index))
437         return false;
438 
439       // If the constraint is already tied, it must be tied to the
440       // same operand referenced to by the number.
441       if (Info.hasTiedOperand() && Info.getTiedOperand() != Index)
442         return false;
443 
444       Info.setTiedOperand(Index, OutputConstraints[Index]);
445       break;
446     }
447     case '%': // commutative
448       // FIXME: Fail if % is used with the last operand.
449       break;
450     case 'i': // immediate integer.
451     case 'n': // immediate integer with a known value.
452       break;
453     case 'I':  // Various constant constraints with target-specific meanings.
454     case 'J':
455     case 'K':
456     case 'L':
457     case 'M':
458     case 'N':
459     case 'O':
460     case 'P':
461       break;
462     case 'r': // general register.
463       Info.setAllowsRegister();
464       break;
465     case 'm': // memory operand.
466     case 'o': // offsettable memory operand.
467     case 'V': // non-offsettable memory operand.
468     case '<': // autodecrement memory operand.
469     case '>': // autoincrement memory operand.
470       Info.setAllowsMemory();
471       break;
472     case 'g': // general register, memory operand or immediate integer.
473     case 'X': // any operand.
474       Info.setAllowsRegister();
475       Info.setAllowsMemory();
476       break;
477     case 'E': // immediate floating point.
478     case 'F': // immediate floating point.
479     case 'p': // address operand.
480       break;
481     case ',': // multiple alternative constraint.  Ignore comma.
482       break;
483     case '?': // Disparage slightly code.
484     case '!': // Disparage severely.
485       break;  // Pass them.
486     }
487 
488     Name++;
489   }
490 
491   return true;
492 }
493