62 lines
2.4 KiB
Plaintext
62 lines
2.4 KiB
Plaintext
THE GNU MP LIBRARY






GNU MP is a library for arbitrary precision arithmetic, operating on


signed integers and rational numbers. It has a rich set of functions,


and the functions have a regular interface.




I have tried to make these functions as fast as possible, both for small


operands and for huge operands. The speed is achieved by using fullwords


as the basic arithmetic type, by using fast algorithms, by defining inline


assembler for mixed sized multiplication and division (i.e 32*32>64 bit


multiplication and 64/32>32,32 bit division), and by hacking the code


with emphasis on speed (and not simplicity and elegance).




The speed of GNU MP is about 5 to 100 times that of Berkeley MP for


small operands. The speedup increases with the operand sizes for


certain operations, for which GNU MP has asymptotically faster algorithms.






There are four classes of functions in GNU MP.




1. Signed integer arithmetic functions, mpz_*. The set of functions are


intended to be easy to use, being rich and regular.




To use these functions, include the file "gmp.h".




2. Rational arithmetic functions, mpq_*. For now, just a small set of


functions necessary for basic rational arithmetics.




To use these functions, include the file "gmp.h".




3. Positiveinteger, lowlevel, hardertouse, but for small operands


about twice as fast than the mpz_* functions are the functions in the


mpn_* class. No memory management is performed. The caller must


ensure enough space is available for the results. The set of


functions is not quite regular, nor is the calling interface. These


functions accept input arguments in the form of pairs consisting of a


pointer to the least significant word, and a integral size telling how


many limbs (= words) the pointer points to.




Almost all calculations, in the entire package, are made in these


lowlevel functions.




These functions are not fully documented in this release. They will


probably be so in a future release.




4. Berkeley MP compatible functions.




To use these functions, include the file "mp.h". You can test if you


are using the GNU version by testing if the symbol __GNU_MP__ is


defined.






REPORTING BUGS




If you find a bug in the library, please make sure to tell us about it!




You can report bugs, and propose modifications and enhancements to


tege@gnu.ai.mit.edu. How to report a bug is further described in


the texinfo documentation, see the file gmp.texi.


