lib/Basic/TargetInfo.cpp - platform/external/clang - Gitiles

 //===--- TargetInfo.cpp - Information about Target machine ----------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 //  This file implements the TargetInfo and TargetInfoImpl interfaces.
 //
 //===----------------------------------------------------------------------===//

 #include "clang/Basic/AddressSpaces.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Basic/LangOptions.h"
 #include "llvm/ADT/APFloat.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/ErrorHandling.h"
 #include <cctype>
 #include <cstdlib>
 using namespace clang;

 static const LangAS::Map DefaultAddrSpaceMap = { 0 };

 // TargetInfo Constructor.
 TargetInfo::TargetInfo(const std::string &T) : Triple(T) {
   // Set defaults.  Defaults are set for a 32-bit RISC platform, like PPC or
   // SPARC.  These should be overridden by concrete targets as needed.
   TLSSupported = true;
   NoAsmVariants = false;
   PointerWidth = PointerAlign = 32;
   BoolWidth = BoolAlign = 8;
   IntWidth = IntAlign = 32;
   LongWidth = LongAlign = 32;
   LongLongWidth = LongLongAlign = 64;
   HalfWidth = 16;
   HalfAlign = 16;
   FloatWidth = 32;
   FloatAlign = 32;
   DoubleWidth = 64;
   DoubleAlign = 64;
   LongDoubleWidth = 64;
   LongDoubleAlign = 64;
   LargeArrayMinWidth = 0;
   LargeArrayAlign = 0;
   MaxAtomicPromoteWidth = MaxAtomicInlineWidth = 0;
   SizeType = UnsignedLong;
   PtrDiffType = SignedLong;
   IntMaxType = SignedLongLong;
   UIntMaxType = UnsignedLongLong;
   IntPtrType = SignedLong;
   WCharType = SignedInt;
   WIntType = SignedInt;
   Char16Type = UnsignedShort;
   Char32Type = UnsignedInt;
   Int64Type = SignedLongLong;
   SigAtomicType = SignedInt;
   UseBitFieldTypeAlignment = true;
   UseZeroLengthBitfieldAlignment = false;
   ZeroLengthBitfieldBoundary = 0;
   HalfFormat = &llvm::APFloat::IEEEhalf;
   FloatFormat = &llvm::APFloat::IEEEsingle;
   DoubleFormat = &llvm::APFloat::IEEEdouble;
   LongDoubleFormat = &llvm::APFloat::IEEEdouble;
   DescriptionString = "E-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-"
                       "i64:64:64-f32:32:32-f64:64:64-n32";
   UserLabelPrefix = "_";
   MCountName = "mcount";
   RegParmMax = 0;
   SSERegParmMax = 0;
   HasAlignMac68kSupport = false;

   // Default to no types using fpret.
   RealTypeUsesObjCFPRet = 0;

   // Default to using the Itanium ABI.
   CXXABI = CXXABI_Itanium;

   // Default to an empty address space map.
   AddrSpaceMap = &DefaultAddrSpaceMap;

   // Default to an unknown platform name.
   PlatformName = "unknown";
   PlatformMinVersion = VersionTuple();
 }

 // Out of line virtual dtor for TargetInfo.
 TargetInfo::~TargetInfo() {}

 /// getTypeName - Return the user string for the specified integer type enum.
 /// For example, SignedShort -> "short".
 const char *TargetInfo::getTypeName(IntType T) {
   switch (T) {
   default: llvm_unreachable("not an integer!");
   case SignedShort:      return "short";
   case UnsignedShort:    return "unsigned short";
   case SignedInt:        return "int";
   case UnsignedInt:      return "unsigned int";
   case SignedLong:       return "long int";
   case UnsignedLong:     return "long unsigned int";
   case SignedLongLong:   return "long long int";
   case UnsignedLongLong: return "long long unsigned int";
   }
 }

 /// getTypeConstantSuffix - Return the constant suffix for the specified
 /// integer type enum. For example, SignedLong -> "L".
 const char *TargetInfo::getTypeConstantSuffix(IntType T) {
   switch (T) {
   default: llvm_unreachable("not an integer!");
   case SignedShort:
   case SignedInt:        return "";
   case SignedLong:       return "L";
   case SignedLongLong:   return "LL";
   case UnsignedShort:
   case UnsignedInt:      return "U";
   case UnsignedLong:     return "UL";
   case UnsignedLongLong: return "ULL";
   }
 }

 /// getTypeWidth - Return the width (in bits) of the specified integer type
 /// enum. For example, SignedInt -> getIntWidth().
 unsigned TargetInfo::getTypeWidth(IntType T) const {
   switch (T) {
   default: llvm_unreachable("not an integer!");
   case SignedShort:
   case UnsignedShort:    return getShortWidth();
   case SignedInt:
   case UnsignedInt:      return getIntWidth();
   case SignedLong:
   case UnsignedLong:     return getLongWidth();
   case SignedLongLong:
   case UnsignedLongLong: return getLongLongWidth();
   };
 }

 /// getTypeAlign - Return the alignment (in bits) of the specified integer type
 /// enum. For example, SignedInt -> getIntAlign().
 unsigned TargetInfo::getTypeAlign(IntType T) const {
   switch (T) {
   default: llvm_unreachable("not an integer!");
   case SignedShort:
   case UnsignedShort:    return getShortAlign();
   case SignedInt:
   case UnsignedInt:      return getIntAlign();
   case SignedLong:
   case UnsignedLong:     return getLongAlign();
   case SignedLongLong:
   case UnsignedLongLong: return getLongLongAlign();
   };
 }

 /// isTypeSigned - Return whether an integer types is signed. Returns true if
 /// the type is signed; false otherwise.
 bool TargetInfo::isTypeSigned(IntType T) {
   switch (T) {
   default: llvm_unreachable("not an integer!");
   case SignedShort:
   case SignedInt:
   case SignedLong:
   case SignedLongLong:
     return true;
   case UnsignedShort:
   case UnsignedInt:
   case UnsignedLong:
   case UnsignedLongLong:
     return false;
   };
 }

 /// setForcedLangOptions - Set forced language options.
 /// Apply changes to the target information with respect to certain
 /// language options which change the target configuration.
 void TargetInfo::setForcedLangOptions(LangOptions &Opts) {
   if (Opts.NoBitFieldTypeAlign)
     UseBitFieldTypeAlignment = false;
   if (Opts.ShortWChar)
     WCharType = UnsignedShort;
 }

 //===----------------------------------------------------------------------===//


 static StringRef removeGCCRegisterPrefix(StringRef Name) {
   if (Name[0] == '%' || Name[0] == '#')
     Name = Name.substr(1);

   return Name;
 }

 /// isValidClobber - Returns whether the passed in string is
 /// a valid clobber in an inline asm statement. This is used by
 /// Sema.
 bool TargetInfo::isValidClobber(StringRef Name) const {
   return (isValidGCCRegisterName(Name) ||
 	  Name == "memory" || Name == "cc");
 }

 /// isValidGCCRegisterName - Returns whether the passed in string
 /// is a valid register name according to GCC. This is used by Sema for
 /// inline asm statements.
 bool TargetInfo::isValidGCCRegisterName(StringRef Name) const {
   if (Name.empty())
     return false;

   const char * const *Names;
   unsigned NumNames;

   // Get rid of any register prefix.
   Name = removeGCCRegisterPrefix(Name);

   getGCCRegNames(Names, NumNames);

   // If we have a number it maps to an entry in the register name array.
   if (isdigit(Name[0])) {
     int n;
     if (!Name.getAsInteger(0, n))
       return n >= 0 && (unsigned)n < NumNames;
   }

   // Check register names.
   for (unsigned i = 0; i < NumNames; i++) {
     if (Name == Names[i])
       return true;
   }

   // Check any additional names that we have.
   const AddlRegName *AddlNames;
   unsigned NumAddlNames;
   getGCCAddlRegNames(AddlNames, NumAddlNames);
   for (unsigned i = 0; i < NumAddlNames; i++)
     for (unsigned j = 0; j < llvm::array_lengthof(AddlNames[i].Names); j++) {
       if (!AddlNames[i].Names[j])
 	break;
       // Make sure the register that the additional name is for is within
       // the bounds of the register names from above.
       if (AddlNames[i].Names[j] == Name && AddlNames[i].RegNum < NumNames)
 	return true;
   }

   // Now check aliases.
   const GCCRegAlias *Aliases;
   unsigned NumAliases;

   getGCCRegAliases(Aliases, NumAliases);
   for (unsigned i = 0; i < NumAliases; i++) {
     for (unsigned j = 0 ; j < llvm::array_lengthof(Aliases[i].Aliases); j++) {
       if (!Aliases[i].Aliases[j])
         break;
       if (Aliases[i].Aliases[j] == Name)
         return true;
     }
   }

   return false;
 }

 StringRef
 TargetInfo::getNormalizedGCCRegisterName(StringRef Name) const {
   assert(isValidGCCRegisterName(Name) && "Invalid register passed in");

   // Get rid of any register prefix.
   Name = removeGCCRegisterPrefix(Name);

   const char * const *Names;
   unsigned NumNames;

   getGCCRegNames(Names, NumNames);

   // First, check if we have a number.
   if (isdigit(Name[0])) {
     int n;
     if (!Name.getAsInteger(0, n)) {
       assert(n >= 0 && (unsigned)n < NumNames &&
              "Out of bounds register number!");
       return Names[n];
     }
   }

   // Check any additional names that we have.
   const AddlRegName *AddlNames;
   unsigned NumAddlNames;
   getGCCAddlRegNames(AddlNames, NumAddlNames);
   for (unsigned i = 0; i < NumAddlNames; i++)
     for (unsigned j = 0; j < llvm::array_lengthof(AddlNames[i].Names); j++) {
       if (!AddlNames[i].Names[j])
 	break;
       // Make sure the register that the additional name is for is within
       // the bounds of the register names from above.
       if (AddlNames[i].Names[j] == Name && AddlNames[i].RegNum < NumNames)
 	return Name;
     }

   // Now check aliases.
   const GCCRegAlias *Aliases;
   unsigned NumAliases;

   getGCCRegAliases(Aliases, NumAliases);
   for (unsigned i = 0; i < NumAliases; i++) {
     for (unsigned j = 0 ; j < llvm::array_lengthof(Aliases[i].Aliases); j++) {
       if (!Aliases[i].Aliases[j])
         break;
       if (Aliases[i].Aliases[j] == Name)
         return Aliases[i].Register;
     }
   }

   return Name;
 }

 bool TargetInfo::validateOutputConstraint(ConstraintInfo &Info) const {
   const char *Name = Info.getConstraintStr().c_str();
   // An output constraint must start with '=' or '+'
   if (*Name != '=' && *Name != '+')
     return false;

   if (*Name == '+')
     Info.setIsReadWrite();

   Name++;
   while (*Name) {
     switch (*Name) {
     default:
       if (!validateAsmConstraint(Name, Info)) {
         // FIXME: We temporarily return false
         // so we can add more constraints as we hit it.
         // Eventually, an unknown constraint should just be treated as 'g'.
         return false;
       }
     case '&': // early clobber.
       break;
     case '%': // commutative.
       // FIXME: Check that there is a another register after this one.
       break;
     case 'r': // general register.
       Info.setAllowsRegister();
       break;
     case 'm': // memory operand.
     case 'o': // offsetable memory operand.
     case 'V': // non-offsetable memory operand.
     case '<': // autodecrement memory operand.
     case '>': // autoincrement memory operand.
       Info.setAllowsMemory();
       break;
     case 'g': // general register, memory operand or immediate integer.
     case 'X': // any operand.
       Info.setAllowsRegister();
       Info.setAllowsMemory();
       break;
     case ',': // multiple alternative constraint.  Pass it.
       // Handle additional optional '=' or '+' modifiers.
       if (Name[1] == '=' || Name[1] == '+')
         Name++;
       break;
     case '?': // Disparage slightly code.
     case '!': // Disparage severely.
       break;  // Pass them.
     }

     Name++;
   }

   return true;
 }

 bool TargetInfo::resolveSymbolicName(const char *&Name,
                                      ConstraintInfo *OutputConstraints,
                                      unsigned NumOutputs,
                                      unsigned &Index) const {
   assert(*Name == '[' && "Symbolic name did not start with '['");
   Name++;
   const char *Start = Name;
   while (*Name && *Name != ']')
     Name++;

   if (!*Name) {
     // Missing ']'
     return false;
   }

   std::string SymbolicName(Start, Name - Start);

   for (Index = 0; Index != NumOutputs; ++Index)
     if (SymbolicName == OutputConstraints[Index].getName())
       return true;

   return false;
 }

 bool TargetInfo::validateInputConstraint(ConstraintInfo *OutputConstraints,
                                          unsigned NumOutputs,
                                          ConstraintInfo &Info) const {
   const char *Name = Info.ConstraintStr.c_str();

   while (*Name) {
     switch (*Name) {
     default:
       // Check if we have a matching constraint
       if (*Name >= '0' && *Name <= '9') {
         unsigned i = *Name - '0';

         // Check if matching constraint is out of bounds.
         if (i >= NumOutputs)
           return false;

         // A number must refer to an output only operand.
         if (OutputConstraints[i].isReadWrite())
           return false;

         // If the constraint is already tied, it must be tied to the
         // same operand referenced to by the number.
         if (Info.hasTiedOperand() && Info.getTiedOperand() != i)
           return false;

         // The constraint should have the same info as the respective
         // output constraint.
         Info.setTiedOperand(i, OutputConstraints[i]);
       } else if (!validateAsmConstraint(Name, Info)) {
         // FIXME: This error return is in place temporarily so we can
         // add more constraints as we hit it.  Eventually, an unknown
         // constraint should just be treated as 'g'.
         return false;
       }
       break;
     case '[': {
       unsigned Index = 0;
       if (!resolveSymbolicName(Name, OutputConstraints, NumOutputs, Index))
         return false;

       // If the constraint is already tied, it must be tied to the
       // same operand referenced to by the number.
       if (Info.hasTiedOperand() && Info.getTiedOperand() != Index)
         return false;

       Info.setTiedOperand(Index, OutputConstraints[Index]);
       break;
     }
     case '%': // commutative
       // FIXME: Fail if % is used with the last operand.
       break;
     case 'i': // immediate integer.
     case 'n': // immediate integer with a known value.
       break;
     case 'I':  // Various constant constraints with target-specific meanings.
     case 'J':
     case 'K':
     case 'L':
     case 'M':
     case 'N':
     case 'O':
     case 'P':
       break;
     case 'r': // general register.
       Info.setAllowsRegister();
       break;
     case 'm': // memory operand.
     case 'o': // offsettable memory operand.
     case 'V': // non-offsettable memory operand.
     case '<': // autodecrement memory operand.
     case '>': // autoincrement memory operand.
       Info.setAllowsMemory();
       break;
     case 'g': // general register, memory operand or immediate integer.
     case 'X': // any operand.
       Info.setAllowsRegister();
       Info.setAllowsMemory();
       break;
     case 'E': // immediate floating point.
     case 'F': // immediate floating point.
     case 'p': // address operand.
       break;
     case ',': // multiple alternative constraint.  Ignore comma.
       break;
     case '?': // Disparage slightly code.
     case '!': // Disparage severely.
       break;  // Pass them.
     }

     Name++;
   }

   return true;
 }
	//===--- TargetInfo.cpp - Information about Target machine ----------------===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This file implements the TargetInfo and TargetInfoImpl interfaces.
	//
	//===----------------------------------------------------------------------===//

	#include "clang/Basic/AddressSpaces.h"
	#include "clang/Basic/TargetInfo.h"
	#include "clang/Basic/LangOptions.h"
	#include "llvm/ADT/APFloat.h"
	#include "llvm/ADT/STLExtras.h"
	#include "llvm/Support/ErrorHandling.h"
	#include <cctype>
	#include <cstdlib>
	using namespace clang;

	static const LangAS::Map DefaultAddrSpaceMap = { 0 };

	// TargetInfo Constructor.
	TargetInfo::TargetInfo(const std::string &T) : Triple(T) {
	// Set defaults. Defaults are set for a 32-bit RISC platform, like PPC or
	// SPARC. These should be overridden by concrete targets as needed.
	TLSSupported = true;
	NoAsmVariants = false;
	PointerWidth = PointerAlign = 32;
	BoolWidth = BoolAlign = 8;
	IntWidth = IntAlign = 32;
	LongWidth = LongAlign = 32;
	LongLongWidth = LongLongAlign = 64;
	HalfWidth = 16;
	HalfAlign = 16;
	FloatWidth = 32;
	FloatAlign = 32;
	DoubleWidth = 64;
	DoubleAlign = 64;
	LongDoubleWidth = 64;
	LongDoubleAlign = 64;
	LargeArrayMinWidth = 0;
	LargeArrayAlign = 0;
	MaxAtomicPromoteWidth = MaxAtomicInlineWidth = 0;
	SizeType = UnsignedLong;
	PtrDiffType = SignedLong;
	IntMaxType = SignedLongLong;
	UIntMaxType = UnsignedLongLong;
	IntPtrType = SignedLong;
	WCharType = SignedInt;
	WIntType = SignedInt;
	Char16Type = UnsignedShort;
	Char32Type = UnsignedInt;
	Int64Type = SignedLongLong;
	SigAtomicType = SignedInt;
	UseBitFieldTypeAlignment = true;
	UseZeroLengthBitfieldAlignment = false;
	ZeroLengthBitfieldBoundary = 0;
	HalfFormat = &llvm::APFloat::IEEEhalf;
	FloatFormat = &llvm::APFloat::IEEEsingle;
	DoubleFormat = &llvm::APFloat::IEEEdouble;
	LongDoubleFormat = &llvm::APFloat::IEEEdouble;
	DescriptionString = "E-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-"
	"i64:64:64-f32:32:32-f64:64:64-n32";
	UserLabelPrefix = "_";
	MCountName = "mcount";
	RegParmMax = 0;
	SSERegParmMax = 0;
	HasAlignMac68kSupport = false;

	// Default to no types using fpret.
	RealTypeUsesObjCFPRet = 0;

	// Default to using the Itanium ABI.
	CXXABI = CXXABI_Itanium;

	// Default to an empty address space map.
	AddrSpaceMap = &DefaultAddrSpaceMap;

	// Default to an unknown platform name.
	PlatformName = "unknown";
	PlatformMinVersion = VersionTuple();
	}

	// Out of line virtual dtor for TargetInfo.
	TargetInfo::~TargetInfo() {}

	/// getTypeName - Return the user string for the specified integer type enum.
	/// For example, SignedShort -> "short".
	const char *TargetInfo::getTypeName(IntType T) {
	switch (T) {
	default: llvm_unreachable("not an integer!");
	case SignedShort: return "short";
	case UnsignedShort: return "unsigned short";
	case SignedInt: return "int";
	case UnsignedInt: return "unsigned int";
	case SignedLong: return "long int";
	case UnsignedLong: return "long unsigned int";
	case SignedLongLong: return "long long int";
	case UnsignedLongLong: return "long long unsigned int";
	}
	}

	/// getTypeConstantSuffix - Return the constant suffix for the specified
	/// integer type enum. For example, SignedLong -> "L".
	const char *TargetInfo::getTypeConstantSuffix(IntType T) {
	switch (T) {
	default: llvm_unreachable("not an integer!");
	case SignedShort:
	case SignedInt: return "";
	case SignedLong: return "L";
	case SignedLongLong: return "LL";
	case UnsignedShort:
	case UnsignedInt: return "U";
	case UnsignedLong: return "UL";
	case UnsignedLongLong: return "ULL";
	}
	}

	/// getTypeWidth - Return the width (in bits) of the specified integer type
	/// enum. For example, SignedInt -> getIntWidth().
	unsigned TargetInfo::getTypeWidth(IntType T) const {
	switch (T) {
	default: llvm_unreachable("not an integer!");
	case SignedShort:
	case UnsignedShort: return getShortWidth();
	case SignedInt:
	case UnsignedInt: return getIntWidth();
	case SignedLong:
	case UnsignedLong: return getLongWidth();
	case SignedLongLong:
	case UnsignedLongLong: return getLongLongWidth();
	};
	}

	/// getTypeAlign - Return the alignment (in bits) of the specified integer type
	/// enum. For example, SignedInt -> getIntAlign().
	unsigned TargetInfo::getTypeAlign(IntType T) const {
	switch (T) {
	default: llvm_unreachable("not an integer!");
	case SignedShort:
	case UnsignedShort: return getShortAlign();
	case SignedInt:
	case UnsignedInt: return getIntAlign();
	case SignedLong:
	case UnsignedLong: return getLongAlign();
	case SignedLongLong:
	case UnsignedLongLong: return getLongLongAlign();
	};
	}

	/// isTypeSigned - Return whether an integer types is signed. Returns true if
	/// the type is signed; false otherwise.
	bool TargetInfo::isTypeSigned(IntType T) {
	switch (T) {
	default: llvm_unreachable("not an integer!");
	case SignedShort:
	case SignedInt:
	case SignedLong:
	case SignedLongLong:
	return true;
	case UnsignedShort:
	case UnsignedInt:
	case UnsignedLong:
	case UnsignedLongLong:
	return false;
	};
	}

	/// setForcedLangOptions - Set forced language options.
	/// Apply changes to the target information with respect to certain
	/// language options which change the target configuration.
	void TargetInfo::setForcedLangOptions(LangOptions &Opts) {
	if (Opts.NoBitFieldTypeAlign)
	UseBitFieldTypeAlignment = false;
	if (Opts.ShortWChar)
	WCharType = UnsignedShort;
	}

	//===----------------------------------------------------------------------===//


	static StringRef removeGCCRegisterPrefix(StringRef Name) {
	if (Name[0] == '%' \|\| Name[0] == '#')
	Name = Name.substr(1);

	return Name;
	}

	/// isValidClobber - Returns whether the passed in string is
	/// a valid clobber in an inline asm statement. This is used by
	/// Sema.
	bool TargetInfo::isValidClobber(StringRef Name) const {
	return (isValidGCCRegisterName(Name) \|\|
	Name == "memory" \|\| Name == "cc");
	}

	/// isValidGCCRegisterName - Returns whether the passed in string
	/// is a valid register name according to GCC. This is used by Sema for
	/// inline asm statements.
	bool TargetInfo::isValidGCCRegisterName(StringRef Name) const {
	if (Name.empty())
	return false;

	const char * const *Names;
	unsigned NumNames;

	// Get rid of any register prefix.
	Name = removeGCCRegisterPrefix(Name);

	getGCCRegNames(Names, NumNames);

	// If we have a number it maps to an entry in the register name array.
	if (isdigit(Name[0])) {
	int n;
	if (!Name.getAsInteger(0, n))
	return n >= 0 && (unsigned)n < NumNames;
	}

	// Check register names.
	for (unsigned i = 0; i < NumNames; i++) {
	if (Name == Names[i])
	return true;
	}

	// Check any additional names that we have.
	const AddlRegName *AddlNames;
	unsigned NumAddlNames;
	getGCCAddlRegNames(AddlNames, NumAddlNames);
	for (unsigned i = 0; i < NumAddlNames; i++)
	for (unsigned j = 0; j < llvm::array_lengthof(AddlNames[i].Names); j++) {
	if (!AddlNames[i].Names[j])
	break;
	// Make sure the register that the additional name is for is within
	// the bounds of the register names from above.
	if (AddlNames[i].Names[j] == Name && AddlNames[i].RegNum < NumNames)
	return true;
	}

	// Now check aliases.
	const GCCRegAlias *Aliases;
	unsigned NumAliases;

	getGCCRegAliases(Aliases, NumAliases);
	for (unsigned i = 0; i < NumAliases; i++) {
	for (unsigned j = 0 ; j < llvm::array_lengthof(Aliases[i].Aliases); j++) {
	if (!Aliases[i].Aliases[j])
	break;
	if (Aliases[i].Aliases[j] == Name)
	return true;
	}
	}

	return false;
	}

	StringRef
	TargetInfo::getNormalizedGCCRegisterName(StringRef Name) const {
	assert(isValidGCCRegisterName(Name) && "Invalid register passed in");

	// Get rid of any register prefix.
	Name = removeGCCRegisterPrefix(Name);

	const char * const *Names;
	unsigned NumNames;

	getGCCRegNames(Names, NumNames);

	// First, check if we have a number.
	if (isdigit(Name[0])) {
	int n;
	if (!Name.getAsInteger(0, n)) {
	assert(n >= 0 && (unsigned)n < NumNames &&
	"Out of bounds register number!");
	return Names[n];
	}
	}

	// Check any additional names that we have.
	const AddlRegName *AddlNames;
	unsigned NumAddlNames;
	getGCCAddlRegNames(AddlNames, NumAddlNames);
	for (unsigned i = 0; i < NumAddlNames; i++)
	for (unsigned j = 0; j < llvm::array_lengthof(AddlNames[i].Names); j++) {
	if (!AddlNames[i].Names[j])
	break;
	// Make sure the register that the additional name is for is within
	// the bounds of the register names from above.
	if (AddlNames[i].Names[j] == Name && AddlNames[i].RegNum < NumNames)
	return Name;
	}

	// Now check aliases.
	const GCCRegAlias *Aliases;
	unsigned NumAliases;

	getGCCRegAliases(Aliases, NumAliases);
	for (unsigned i = 0; i < NumAliases; i++) {
	for (unsigned j = 0 ; j < llvm::array_lengthof(Aliases[i].Aliases); j++) {
	if (!Aliases[i].Aliases[j])
	break;
	if (Aliases[i].Aliases[j] == Name)
	return Aliases[i].Register;
	}
	}

	return Name;
	}

	bool TargetInfo::validateOutputConstraint(ConstraintInfo &Info) const {
	const char *Name = Info.getConstraintStr().c_str();
	// An output constraint must start with '=' or '+'
	if (Name != '=' && Name != '+')
	return false;

	if (*Name == '+')
	Info.setIsReadWrite();

	Name++;
	while (*Name) {
	switch (*Name) {
	default:
	if (!validateAsmConstraint(Name, Info)) {
	// FIXME: We temporarily return false
	// so we can add more constraints as we hit it.
	// Eventually, an unknown constraint should just be treated as 'g'.
	return false;
	}
	case '&': // early clobber.
	break;
	case '%': // commutative.
	// FIXME: Check that there is a another register after this one.
	break;
	case 'r': // general register.
	Info.setAllowsRegister();
	break;
	case 'm': // memory operand.
	case 'o': // offsetable memory operand.
	case 'V': // non-offsetable memory operand.
	case '<': // autodecrement memory operand.
	case '>': // autoincrement memory operand.
	Info.setAllowsMemory();
	break;
	case 'g': // general register, memory operand or immediate integer.
	case 'X': // any operand.
	Info.setAllowsRegister();
	Info.setAllowsMemory();
	break;
	case ',': // multiple alternative constraint. Pass it.
	// Handle additional optional '=' or '+' modifiers.
	if (Name[1] == '=' \|\| Name[1] == '+')
	Name++;
	break;
	case '?': // Disparage slightly code.
	case '!': // Disparage severely.
	break; // Pass them.
	}

	Name++;
	}

	return true;
	}

	bool TargetInfo::resolveSymbolicName(const char *&Name,
	ConstraintInfo *OutputConstraints,
	unsigned NumOutputs,
	unsigned &Index) const {
	assert(*Name == '[' && "Symbolic name did not start with '['");
	Name++;
	const char *Start = Name;
	while (Name && Name != ']')
	Name++;

	if (!*Name) {
	// Missing ']'
	return false;
	}

	std::string SymbolicName(Start, Name - Start);

	for (Index = 0; Index != NumOutputs; ++Index)
	if (SymbolicName == OutputConstraints[Index].getName())
	return true;

	return false;
	}

	bool TargetInfo::validateInputConstraint(ConstraintInfo *OutputConstraints,
	unsigned NumOutputs,
	ConstraintInfo &Info) const {
	const char *Name = Info.ConstraintStr.c_str();

	while (*Name) {
	switch (*Name) {
	default:
	// Check if we have a matching constraint
	if (Name >= '0' && Name <= '9') {
	unsigned i = *Name - '0';

	// Check if matching constraint is out of bounds.
	if (i >= NumOutputs)
	return false;

	// A number must refer to an output only operand.
	if (OutputConstraints[i].isReadWrite())
	return false;

	// If the constraint is already tied, it must be tied to the
	// same operand referenced to by the number.
	if (Info.hasTiedOperand() && Info.getTiedOperand() != i)
	return false;

	// The constraint should have the same info as the respective
	// output constraint.
	Info.setTiedOperand(i, OutputConstraints[i]);
	} else if (!validateAsmConstraint(Name, Info)) {
	// FIXME: This error return is in place temporarily so we can
	// add more constraints as we hit it. Eventually, an unknown
	// constraint should just be treated as 'g'.
	return false;
	}
	break;
	case '[': {
	unsigned Index = 0;
	if (!resolveSymbolicName(Name, OutputConstraints, NumOutputs, Index))
	return false;

	// If the constraint is already tied, it must be tied to the
	// same operand referenced to by the number.
	if (Info.hasTiedOperand() && Info.getTiedOperand() != Index)
	return false;

	Info.setTiedOperand(Index, OutputConstraints[Index]);
	break;
	}
	case '%': // commutative
	// FIXME: Fail if % is used with the last operand.
	break;
	case 'i': // immediate integer.
	case 'n': // immediate integer with a known value.
	break;
	case 'I': // Various constant constraints with target-specific meanings.
	case 'J':
	case 'K':
	case 'L':
	case 'M':
	case 'N':
	case 'O':
	case 'P':
	break;
	case 'r': // general register.
	Info.setAllowsRegister();
	break;
	case 'm': // memory operand.
	case 'o': // offsettable memory operand.
	case 'V': // non-offsettable memory operand.
	case '<': // autodecrement memory operand.
	case '>': // autoincrement memory operand.
	Info.setAllowsMemory();
	break;
	case 'g': // general register, memory operand or immediate integer.
	case 'X': // any operand.
	Info.setAllowsRegister();
	Info.setAllowsMemory();
	break;
	case 'E': // immediate floating point.
	case 'F': // immediate floating point.
	case 'p': // address operand.
	break;
	case ',': // multiple alternative constraint. Ignore comma.
	break;
	case '?': // Disparage slightly code.
	case '!': // Disparage severely.
	break; // Pass them.
	}

	Name++;
	}

	return true;
	}