diff options
Diffstat (limited to 'src/base')
| -rw-r--r-- | src/base/bitfield.hh | 269 | ||||
| -rw-r--r-- | src/base/bitunion.hh | 313 | ||||
| -rw-r--r-- | src/base/condcodes.hh | 94 |
3 files changed, 407 insertions, 269 deletions
diff --git a/src/base/bitfield.hh b/src/base/bitfield.hh index 70a46386e..664093fa2 100644 --- a/src/base/bitfield.hh +++ b/src/base/bitfield.hh @@ -161,273 +161,4 @@ findMsbSet(uint64_t val) { return msb; } -// The following implements the BitUnion system of defining bitfields -//on top of an underlying class. This is done through the pervasive use of -//both named and unnamed unions which all contain the same actual storage. -//Since they're unioned with each other, all of these storage locations -//overlap. This allows all of the bitfields to manipulate the same data -//without having to have access to each other. More details are provided with the -//individual components. - -//This namespace is for classes which implement the backend of the BitUnion -//stuff. Don't use any of these directly, except for the Bitfield classes in -//the *BitfieldTypes class(es). -namespace BitfieldBackend -{ - //A base class for all bitfields. It instantiates the actual storage, - //and provides getBits and setBits functions for manipulating it. The - //Data template parameter is type of the underlying storage. - template<class Data> - class BitfieldBase - { - protected: - Data __data; - - //This function returns a range of bits from the underlying storage. - //It relies on the "bits" function above. It's the user's - //responsibility to make sure that there is a properly overloaded - //version of this function for whatever type they want to overlay. - inline uint64_t - getBits(int first, int last) const - { - return bits(__data, first, last); - } - - //Similar to the above, but for settings bits with replaceBits. - inline void - setBits(int first, int last, uint64_t val) - { - replaceBits(__data, first, last, val); - } - }; - - //This class contains all the "regular" bitfield classes. It is inherited - //by all BitUnions which give them access to those types. - template<class Type> - class RegularBitfieldTypes - { - protected: - //This class implements ordinary bitfields, that is a span of bits - //who's msb is "first", and who's lsb is "last". - template<int first, int last=first> - class Bitfield : public BitfieldBase<Type> - { - public: - operator uint64_t () const - { - return this->getBits(first, last); - } - - uint64_t - operator=(const uint64_t _data) - { - this->setBits(first, last, _data); - return _data; - } - }; - - //A class which specializes the above so that it can only be read - //from. This is accomplished explicitly making sure the assignment - //operator is blocked. The conversion operator is carried through - //inheritance. This will unfortunately need to be copied into each - //bitfield type due to limitations with how templates work - template<int first, int last=first> - class BitfieldRO : public Bitfield<first, last> - { - private: - uint64_t - operator=(const uint64_t _data); - }; - - //Similar to the above, but only allows writing. - template<int first, int last=first> - class BitfieldWO : public Bitfield<first, last> - { - private: - operator uint64_t () const; - - public: - using Bitfield<first, last>::operator=; - }; - }; - - //This class contains all the "regular" bitfield classes. It is inherited - //by all BitUnions which give them access to those types. - template<class Type> - class SignedBitfieldTypes - { - protected: - //This class implements ordinary bitfields, that is a span of bits - //who's msb is "first", and who's lsb is "last". - template<int first, int last=first> - class SignedBitfield : public BitfieldBase<Type> - { - public: - operator int64_t () const - { - return sext<first - last + 1>(this->getBits(first, last)); - } - - int64_t - operator=(const int64_t _data) - { - this->setBits(first, last, _data); - return _data; - } - }; - - //A class which specializes the above so that it can only be read - //from. This is accomplished explicitly making sure the assignment - //operator is blocked. The conversion operator is carried through - //inheritance. This will unfortunately need to be copied into each - //bitfield type due to limitations with how templates work - template<int first, int last=first> - class SignedBitfieldRO : public SignedBitfield<first, last> - { - private: - int64_t - operator=(const int64_t _data); - }; - - //Similar to the above, but only allows writing. - template<int first, int last=first> - class SignedBitfieldWO : public SignedBitfield<first, last> - { - private: - operator int64_t () const; - - public: - int64_t operator=(const int64_t _data) - { - *((SignedBitfield<first, last> *)this) = _data; - return _data; - } - }; - }; - - template<class Type> - class BitfieldTypes : public RegularBitfieldTypes<Type>, - public SignedBitfieldTypes<Type> - {}; - - //When a BitUnion is set up, an underlying class is created which holds - //the actual union. This class then inherits from it, and provids the - //implementations for various operators. Setting things up this way - //prevents having to redefine these functions in every different BitUnion - //type. More operators could be implemented in the future, as the need - //arises. - template <class Type, class Base> - class BitUnionOperators : public Base - { - public: - operator Type () const - { - return Base::__data; - } - - Type - operator=(const Type & _data) - { - Base::__data = _data; - return _data; - } - - bool - operator<(const Base & base) const - { - return Base::__data < base.__data; - } - - bool - operator==(const Base & base) const - { - return Base::__data == base.__data; - } - }; -} - -//This macro is a backend for other macros that specialize it slightly. -//First, it creates/extends a namespace "BitfieldUnderlyingClasses" and -//sticks the class which has the actual union in it, which -//BitfieldOperators above inherits from. Putting these classes in a special -//namespace ensures that there will be no collisions with other names as long -//as the BitUnion names themselves are all distinct and nothing else uses -//the BitfieldUnderlyingClasses namespace, which is unlikely. The class itself -//creates a typedef of the "type" parameter called __DataType. This allows -//the type to propagate outside of the macro itself in a controlled way. -//Finally, the base storage is defined which BitfieldOperators will refer to -//in the operators it defines. This macro is intended to be followed by -//bitfield definitions which will end up inside it's union. As explained -//above, these is overlayed the __data member in its entirety by each of the -//bitfields which are defined in the union, creating shared storage with no -//overhead. -#define __BitUnion(type, name) \ - namespace BitfieldUnderlyingClasses \ - { \ - class name; \ - } \ - class BitfieldUnderlyingClasses::name : \ - public BitfieldBackend::BitfieldTypes<type> \ - { \ - public: \ - typedef type __DataType; \ - union { \ - type __data;\ - -//This closes off the class and union started by the above macro. It is -//followed by a typedef which makes "name" refer to a BitfieldOperator -//class inheriting from the class and union just defined, which completes -//building up the type for the user. -#define EndBitUnion(name) \ - }; \ - }; \ - typedef BitfieldBackend::BitUnionOperators< \ - BitfieldUnderlyingClasses::name::__DataType, \ - BitfieldUnderlyingClasses::name> name; - -//This sets up a bitfield which has other bitfields nested inside of it. The -//__data member functions like the "underlying storage" of the top level -//BitUnion. Like everything else, it overlays with the top level storage, so -//making it a regular bitfield type makes the entire thing function as a -//regular bitfield when referred to by itself. -#define __SubBitUnion(fieldType, first, last, name) \ - class : public BitfieldBackend::BitfieldTypes<__DataType> \ - { \ - public: \ - union { \ - fieldType<first, last> __data; - -//This closes off the union created above and gives it a name. Unlike the top -//level BitUnion, we're interested in creating an object instead of a type. -//The operators are defined in the macro itself instead of a class for -//technical reasons. If someone determines a way to move them to one, please -//do so. -#define EndSubBitUnion(name) \ - }; \ - inline operator const __DataType () \ - { return __data; } \ - \ - inline const __DataType operator = (const __DataType & _data) \ - { __data = _data; } \ - } name; - -//Regular bitfields -//These define macros for read/write regular bitfield based subbitfields. -#define SubBitUnion(name, first, last) \ - __SubBitUnion(Bitfield, first, last, name) - -//Regular bitfields -//These define macros for read/write regular bitfield based subbitfields. -#define SignedSubBitUnion(name, first, last) \ - __SubBitUnion(SignedBitfield, first, last, name) - -//Use this to define an arbitrary type overlayed with bitfields. -#define BitUnion(type, name) __BitUnion(type, name) - -//Use this to define conveniently sized values overlayed with bitfields. -#define BitUnion64(name) __BitUnion(uint64_t, name) -#define BitUnion32(name) __BitUnion(uint32_t, name) -#define BitUnion16(name) __BitUnion(uint16_t, name) -#define BitUnion8(name) __BitUnion(uint8_t, name) - #endif // __BASE_BITFIELD_HH__ diff --git a/src/base/bitunion.hh b/src/base/bitunion.hh new file mode 100644 index 000000000..c02ca6155 --- /dev/null +++ b/src/base/bitunion.hh @@ -0,0 +1,313 @@ +/* + * Copyright (c) 2003-2005 The Regents of The University of Michigan + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Gabe Black + */ + +#ifndef __BASE_BITUNION_HH__ +#define __BASE_BITUNION_HH__ + +#include <inttypes.h> +#include "base/bitfield.hh" + +// The following implements the BitUnion system of defining bitfields +//on top of an underlying class. This is done through the pervasive use of +//both named and unnamed unions which all contain the same actual storage. +//Since they're unioned with each other, all of these storage locations +//overlap. This allows all of the bitfields to manipulate the same data +//without having to have access to each other. More details are provided with +//the individual components. + +//This namespace is for classes which implement the backend of the BitUnion +//stuff. Don't use any of these directly, except for the Bitfield classes in +//the *BitfieldTypes class(es). +namespace BitfieldBackend +{ + //A base class for all bitfields. It instantiates the actual storage, + //and provides getBits and setBits functions for manipulating it. The + //Data template parameter is type of the underlying storage. + template<class Data> + class BitfieldBase + { + protected: + Data __data; + + //This function returns a range of bits from the underlying storage. + //It relies on the "bits" function above. It's the user's + //responsibility to make sure that there is a properly overloaded + //version of this function for whatever type they want to overlay. + inline uint64_t + getBits(int first, int last) const + { + return bits(__data, first, last); + } + + //Similar to the above, but for settings bits with replaceBits. + inline void + setBits(int first, int last, uint64_t val) + { + replaceBits(__data, first, last, val); + } + }; + + //This class contains all the "regular" bitfield classes. It is inherited + //by all BitUnions which give them access to those types. + template<class Type> + class RegularBitfieldTypes + { + protected: + //This class implements ordinary bitfields, that is a span of bits + //who's msb is "first", and who's lsb is "last". + template<int first, int last=first> + class Bitfield : public BitfieldBase<Type> + { + public: + operator uint64_t () const + { + return this->getBits(first, last); + } + + uint64_t + operator=(const uint64_t _data) + { + this->setBits(first, last, _data); + return _data; + } + }; + + //A class which specializes the above so that it can only be read + //from. This is accomplished explicitly making sure the assignment + //operator is blocked. The conversion operator is carried through + //inheritance. This will unfortunately need to be copied into each + //bitfield type due to limitations with how templates work + template<int first, int last=first> + class BitfieldRO : public Bitfield<first, last> + { + private: + uint64_t + operator=(const uint64_t _data); + }; + + //Similar to the above, but only allows writing. + template<int first, int last=first> + class BitfieldWO : public Bitfield<first, last> + { + private: + operator uint64_t () const; + + public: + using Bitfield<first, last>::operator=; + }; + }; + + //This class contains all the "regular" bitfield classes. It is inherited + //by all BitUnions which give them access to those types. + template<class Type> + class SignedBitfieldTypes + { + protected: + //This class implements ordinary bitfields, that is a span of bits + //who's msb is "first", and who's lsb is "last". + template<int first, int last=first> + class SignedBitfield : public BitfieldBase<Type> + { + public: + operator int64_t () const + { + return sext<first - last + 1>(this->getBits(first, last)); + } + + int64_t + operator=(const int64_t _data) + { + this->setBits(first, last, _data); + return _data; + } + }; + + //A class which specializes the above so that it can only be read + //from. This is accomplished explicitly making sure the assignment + //operator is blocked. The conversion operator is carried through + //inheritance. This will unfortunately need to be copied into each + //bitfield type due to limitations with how templates work + template<int first, int last=first> + class SignedBitfieldRO : public SignedBitfield<first, last> + { + private: + int64_t + operator=(const int64_t _data); + }; + + //Similar to the above, but only allows writing. + template<int first, int last=first> + class SignedBitfieldWO : public SignedBitfield<first, last> + { + private: + operator int64_t () const; + + public: + int64_t operator=(const int64_t _data) + { + *((SignedBitfield<first, last> *)this) = _data; + return _data; + } + }; + }; + + template<class Type> + class BitfieldTypes : public RegularBitfieldTypes<Type>, + public SignedBitfieldTypes<Type> + {}; + + //When a BitUnion is set up, an underlying class is created which holds + //the actual union. This class then inherits from it, and provids the + //implementations for various operators. Setting things up this way + //prevents having to redefine these functions in every different BitUnion + //type. More operators could be implemented in the future, as the need + //arises. + template <class Type, class Base> + class BitUnionOperators : public Base + { + public: + BitUnionOperators(Type & _data) + { + Base::__data = _data; + } + + BitUnionOperators() {} + + operator Type () const + { + return Base::__data; + } + + Type + operator=(const Type & _data) + { + Base::__data = _data; + return _data; + } + + bool + operator<(const Base & base) const + { + return Base::__data < base.__data; + } + + bool + operator==(const Base & base) const + { + return Base::__data == base.__data; + } + }; +} + +//This macro is a backend for other macros that specialize it slightly. +//First, it creates/extends a namespace "BitfieldUnderlyingClasses" and +//sticks the class which has the actual union in it, which +//BitfieldOperators above inherits from. Putting these classes in a special +//namespace ensures that there will be no collisions with other names as long +//as the BitUnion names themselves are all distinct and nothing else uses +//the BitfieldUnderlyingClasses namespace, which is unlikely. The class itself +//creates a typedef of the "type" parameter called __DataType. This allows +//the type to propagate outside of the macro itself in a controlled way. +//Finally, the base storage is defined which BitfieldOperators will refer to +//in the operators it defines. This macro is intended to be followed by +//bitfield definitions which will end up inside it's union. As explained +//above, these is overlayed the __data member in its entirety by each of the +//bitfields which are defined in the union, creating shared storage with no +//overhead. +#define __BitUnion(type, name) \ + namespace BitfieldUnderlyingClasses \ + { \ + class name; \ + } \ + class BitfieldUnderlyingClasses::name : \ + public BitfieldBackend::BitfieldTypes<type> \ + { \ + public: \ + typedef type __DataType; \ + union { \ + type __data;\ + +//This closes off the class and union started by the above macro. It is +//followed by a typedef which makes "name" refer to a BitfieldOperator +//class inheriting from the class and union just defined, which completes +//building up the type for the user. +#define EndBitUnion(name) \ + }; \ + }; \ + typedef BitfieldBackend::BitUnionOperators< \ + BitfieldUnderlyingClasses::name::__DataType, \ + BitfieldUnderlyingClasses::name> name; + +//This sets up a bitfield which has other bitfields nested inside of it. The +//__data member functions like the "underlying storage" of the top level +//BitUnion. Like everything else, it overlays with the top level storage, so +//making it a regular bitfield type makes the entire thing function as a +//regular bitfield when referred to by itself. +#define __SubBitUnion(fieldType, first, last, name) \ + class : public BitfieldBackend::BitfieldTypes<__DataType> \ + { \ + public: \ + union { \ + fieldType<first, last> __data; + +//This closes off the union created above and gives it a name. Unlike the top +//level BitUnion, we're interested in creating an object instead of a type. +//The operators are defined in the macro itself instead of a class for +//technical reasons. If someone determines a way to move them to one, please +//do so. +#define EndSubBitUnion(name) \ + }; \ + inline operator const __DataType () \ + { return __data; } \ + \ + inline const __DataType operator = (const __DataType & _data) \ + { return __data = _data;} \ + } name; + +//Regular bitfields +//These define macros for read/write regular bitfield based subbitfields. +#define SubBitUnion(name, first, last) \ + __SubBitUnion(Bitfield, first, last, name) + +//Regular bitfields +//These define macros for read/write regular bitfield based subbitfields. +#define SignedSubBitUnion(name, first, last) \ + __SubBitUnion(SignedBitfield, first, last, name) + +//Use this to define an arbitrary type overlayed with bitfields. +#define BitUnion(type, name) __BitUnion(type, name) + +//Use this to define conveniently sized values overlayed with bitfields. +#define BitUnion64(name) __BitUnion(uint64_t, name) +#define BitUnion32(name) __BitUnion(uint32_t, name) +#define BitUnion16(name) __BitUnion(uint16_t, name) +#define BitUnion8(name) __BitUnion(uint8_t, name) + +#endif // __BASE_BITUNION_HH__ diff --git a/src/base/condcodes.hh b/src/base/condcodes.hh new file mode 100644 index 000000000..efff12dc8 --- /dev/null +++ b/src/base/condcodes.hh @@ -0,0 +1,94 @@ +/* + * Copyright (c) 2003-2005 The Regents of The University of Michigan + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Gabe Black + */ + +#ifndef __BASE_CONDCODE_HH__ +#define __BASE_CONDCODE_HH__ + +#include "base/bitfield.hh" +#include "base/trace.hh" + +/** + * Calculate the carry flag from an addition. This should work even when + * a carry value is also added in. + */ +inline +bool +findCarry(int width, uint64_t dest, uint64_t src1, uint64_t src2) { + int shift = width - 1; + return ((~(dest >> shift) & 1) + + ((src1 >> shift) & 1) + + ((src2 >> shift) & 1)) & 0x2; +} + +/** + * Calculate the overflow flag from an addition. + */ +inline +bool +findOverflow(int width, uint64_t dest, uint64_t src1, uint64_t src2) { + int shift = width - 1; + return ((src1 ^ ~src2) & (src1 ^ dest)) & (1 << shift); +} + +/** + * Calculate the parity of a value. 1 is for odd parity and 0 is for even. + */ +inline +bool +findParity(int width, uint64_t dest) { + dest &= width; + dest ^= (dest >> 32); + dest ^= (dest >> 16); + dest ^= (dest >> 8); + dest ^= (dest >> 4); + dest ^= (dest >> 2); + dest ^= (dest >> 1); + return dest & 1; +} + +/** + * Calculate the negative flag. + */ +inline +bool +findNegative(int width, uint64_t dest) { + return bits(dest, width - 1, width - 1); +} + +/** + * Calculate the zero flag. + */ +inline +bool +findZero(int width, uint64_t dest) { + return !(dest & mask(width)); +} + +#endif // __BASE_CONDCODE_HH__ |