62 lines
2.4 KiB
Plaintext
62 lines
2.4 KiB
Plaintext
THE GNU MP LIBRARY
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GNU MP is a library for arbitrary precision arithmetic, operating on
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signed integers and rational numbers. It has a rich set of functions,
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and the functions have a regular interface.
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I have tried to make these functions as fast as possible, both for small
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operands and for huge operands. The speed is achieved by using fullwords
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as the basic arithmetic type, by using fast algorithms, by defining inline
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assembler for mixed sized multiplication and division (i.e 32*32->64 bit
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multiplication and 64/32->32,32 bit division), and by hacking the code
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with emphasis on speed (and not simplicity and elegance).
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The speed of GNU MP is about 5 to 100 times that of Berkeley MP for
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small operands. The speed-up increases with the operand sizes for
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certain operations, for which GNU MP has asymptotically faster algorithms.
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There are four classes of functions in GNU MP.
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1. Signed integer arithmetic functions, mpz_*. The set of functions are
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intended to be easy to use, being rich and regular.
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To use these functions, include the file "gmp.h".
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2. Rational arithmetic functions, mpq_*. For now, just a small set of
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functions necessary for basic rational arithmetics.
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To use these functions, include the file "gmp.h".
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3. Positive-integer, low-level, harder-to-use, but for small operands
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about twice as fast than the mpz_* functions are the functions in the
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mpn_* class. No memory management is performed. The caller must
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ensure enough space is available for the results. The set of
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functions is not quite regular, nor is the calling interface. These
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functions accept input arguments in the form of pairs consisting of a
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pointer to the least significant word, and a integral size telling how
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many limbs (= words) the pointer points to.
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Almost all calculations, in the entire package, are made in these
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low-level functions.
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These functions are not fully documented in this release. They will
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probably be so in a future release.
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4. Berkeley MP compatible functions.
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To use these functions, include the file "mp.h". You can test if you
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are using the GNU version by testing if the symbol __GNU_MP__ is
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defined.
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REPORTING BUGS
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If you find a bug in the library, please make sure to tell us about it!
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You can report bugs, and propose modifications and enhancements to
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tege@gnu.ai.mit.edu. How to report a bug is further described in
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the texinfo documentation, see the file gmp.texi.
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