version 1.1.1.2, 2000/09/09 14:12:18 |
version 1.1.1.4, 2003/08/25 16:06:02 |
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This is gmp.info, produced by makeinfo version 4.0 from gmp.texi. |
This is gmp.info, produced by makeinfo version 4.2 from gmp.texi. |
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This manual describes how to install and use the GNU multiple precision |
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arithmetic library, version 4.1.2. |
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Copyright 1991, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, |
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2001, 2002 Free Software Foundation, Inc. |
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Permission is granted to copy, distribute and/or modify this |
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document under the terms of the GNU Free Documentation License, Version |
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1.1 or any later version published by the Free Software Foundation; |
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with no Invariant Sections, with the Front-Cover Texts being "A GNU |
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Manual", and with the Back-Cover Texts being "You have freedom to copy |
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and modify this GNU Manual, like GNU software". A copy of the license |
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is included in *Note GNU Free Documentation License::. |
INFO-DIR-SECTION GNU libraries |
INFO-DIR-SECTION GNU libraries |
START-INFO-DIR-ENTRY |
START-INFO-DIR-ENTRY |
* gmp: (gmp). GNU Multiple Precision Arithmetic Library. |
* gmp: (gmp). GNU Multiple Precision Arithmetic Library. |
END-INFO-DIR-ENTRY |
END-INFO-DIR-ENTRY |
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This file documents GNU MP, a library for arbitrary-precision |
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arithmetic. |
File: gmp.info, Node: Parameter Conventions, Next: Memory Management, Prev: Variable Conventions, Up: GMP Basics |
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Copyright (C) 1991, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000 |
Parameter Conventions |
Free Software Foundation, Inc. |
===================== |
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Permission is granted to make and distribute verbatim copies of this |
When a GMP variable is used as a function parameter, it's |
manual provided the copyright notice and this permission notice are |
effectively a call-by-reference, meaning if the function stores a value |
preserved on all copies. |
there it will change the original in the caller. Parameters which are |
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input-only can be designated `const' to provoke a compiler error or |
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warning on attempting to modify them. |
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Permission is granted to copy and distribute modified versions of |
When a function is going to return a GMP result, it should designate |
this manual under the conditions for verbatim copying, provided that |
a parameter that it sets, like the library functions do. More than one |
the entire resulting derived work is distributed under the terms of a |
value can be returned by having more than one output parameter, again |
permission notice identical to this one. |
like the library functions. A `return' of an `mpz_t' etc doesn't |
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return the object, only a pointer, and this is almost certainly not |
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what's wanted. |
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Permission is granted to copy and distribute translations of this |
Here's an example accepting an `mpz_t' parameter, doing a |
manual into another language, under the above conditions for modified |
calculation, and storing the result to the indicated parameter. |
versions, except that this permission notice may be stated in a |
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translation approved by the Foundation. |
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void |
File: gmp.info, Node: Integer Exponentiation, Next: Integer Roots, Prev: Integer Division, Up: Integer Functions |
foo (mpz_t result, const mpz_t param, unsigned long n) |
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{ |
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unsigned long i; |
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mpz_mul_ui (result, param, n); |
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for (i = 1; i < n; i++) |
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mpz_add_ui (result, result, i*7); |
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} |
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int |
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main (void) |
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{ |
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mpz_t r, n; |
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mpz_init (r); |
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mpz_init_set_str (n, "123456", 0); |
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foo (r, n, 20L); |
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gmp_printf ("%Zd\n", r); |
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return 0; |
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} |
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Exponentiation Functions |
`foo' works even if the mainline passes the same variable for |
======================== |
`param' and `result', just like the library functions. But sometimes |
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it's tricky to make that work, and an application might not want to |
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bother supporting that sort of thing. |
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- Function: void mpz_powm (mpz_t ROP, mpz_t BASE, mpz_t EXP, mpz_t MOD) |
For interest, the GMP types `mpz_t' etc are implemented as |
- Function: void mpz_powm_ui (mpz_t ROP, mpz_t BASE, unsigned long int |
one-element arrays of certain structures. This is why declaring a |
EXP, mpz_t MOD) |
variable creates an object with the fields GMP needs, but then using it |
Set ROP to (BASE raised to EXP) `mod' MOD. If EXP is negative, |
as a parameter passes a pointer to the object. Note that the actual |
the result is undefined. |
fields in each `mpz_t' etc are for internal use only and should not be |
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accessed directly by code that expects to be compatible with future GMP |
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releases. |
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File: gmp.info, Node: Memory Management, Next: Reentrancy, Prev: Parameter Conventions, Up: GMP Basics |
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- Function: void mpz_pow_ui (mpz_t ROP, mpz_t BASE, unsigned long int |
Memory Management |
EXP) |
================= |
- Function: void mpz_ui_pow_ui (mpz_t ROP, unsigned long int BASE, |
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unsigned long int EXP) |
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Set ROP to BASE raised to EXP. The case of 0^0 yields 1. |
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The GMP types like `mpz_t' are small, containing only a couple of |
File: gmp.info, Node: Integer Roots, Next: Number Theoretic Functions, Prev: Integer Exponentiation, Up: Integer Functions |
sizes, and pointers to allocated data. Once a variable is initialized, |
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GMP takes care of all space allocation. Additional space is allocated |
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whenever a variable doesn't have enough. |
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Root Extraction Functions |
`mpz_t' and `mpq_t' variables never reduce their allocated space. |
========================= |
Normally this is the best policy, since it avoids frequent reallocation. |
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Applications that need to return memory to the heap at some particular |
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point can use `mpz_realloc2', or clear variables no longer needed. |
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- Function: int mpz_root (mpz_t ROP, mpz_t OP, unsigned long int N) |
`mpf_t' variables, in the current implementation, use a fixed amount |
Set ROP to the truncated integer part of the Nth root of OP. |
of space, determined by the chosen precision and allocated at |
Return non-zero if the computation was exact, i.e., if OP is ROP |
initialization, so their size doesn't change. |
to the Nth power. |
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- Function: void mpz_sqrt (mpz_t ROP, mpz_t OP) |
All memory is allocated using `malloc' and friends by default, but |
Set ROP to the truncated integer part of the square root of OP. |
this can be changed, see *Note Custom Allocation::. Temporary memory |
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on the stack is also used (via `alloca'), but this can be changed at |
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build-time if desired, see *Note Build Options::. |
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- Function: void mpz_sqrtrem (mpz_t ROP1, mpz_t ROP2, mpz_t OP) |
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Set ROP1 to the truncated integer part of the square root of OP, |
File: gmp.info, Node: Reentrancy, Next: Useful Macros and Constants, Prev: Memory Management, Up: GMP Basics |
like `mpz_sqrt'. Set ROP2 to OP-ROP1*ROP1, (i.e., zero if OP is a |
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perfect square). |
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If ROP1 and ROP2 are the same variable, the results are undefined. |
Reentrancy |
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========== |
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- Function: int mpz_perfect_power_p (mpz_t OP) |
GMP is reentrant and thread-safe, with some exceptions: |
Return non-zero if OP is a perfect power, i.e., if there exist |
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integers A and B, with B > 1, such that OP equals a raised to b. |
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Return zero otherwise. |
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- Function: int mpz_perfect_square_p (mpz_t OP) |
* If configured with `--enable-alloca=malloc-notreentrant' (or with |
Return non-zero if OP is a perfect square, i.e., if the square |
`--enable-alloca=notreentrant' when `alloca' is not available), |
root of OP is an integer. Return zero otherwise. |
then naturally GMP is not reentrant. |
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* `mpf_set_default_prec' and `mpf_init' use a global variable for the |
File: gmp.info, Node: Number Theoretic Functions, Next: Integer Comparisons, Prev: Integer Roots, Up: Integer Functions |
selected precision. `mpf_init2' can be used instead. |
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Number Theoretic Functions |
* `mpz_random' and the other old random number functions use a global |
========================== |
random state and are hence not reentrant. The newer random number |
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functions that accept a `gmp_randstate_t' parameter can be used |
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instead. |
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- Function: int mpz_probab_prime_p (mpz_t N, int REPS) |
* `mp_set_memory_functions' uses global variables to store the |
If this function returns 0, N is definitely not prime. If it |
selected memory allocation functions. |
returns 1, then N is `probably' prime. If it returns 2, then N is |
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surely prime. Reasonable values of reps vary from 5 to 10; a |
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higher value lowers the probability for a non-prime to pass as a |
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`probable' prime. |
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The function uses Miller-Rabin's probabilistic test. |
* If the memory allocation functions set by a call to |
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`mp_set_memory_functions' (or `malloc' and friends by default) are |
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not reentrant, then GMP will not be reentrant either. |
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- Function: int mpz_nextprime (mpz_t ROP, mpz_t OP) |
* If the standard I/O functions such as `fwrite' are not reentrant |
Set ROP to the next prime greater than OP. |
then the GMP I/O functions using them will not be reentrant either. |
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This function uses a probabilistic algorithm to identify primes, |
* It's safe for two threads to read from the same GMP variable |
but for for practical purposes it's adequate, since the chance of |
simultaneously, but it's not safe for one to read while the |
a composite passing will be extremely small. |
another might be writing, nor for two threads to write |
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simultaneously. It's not safe for two threads to generate a |
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random number from the same `gmp_randstate_t' simultaneously, |
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since this involves an update of that variable. |
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- Function: void mpz_gcd (mpz_t ROP, mpz_t OP1, mpz_t OP2) |
* On SCO systems the default `<ctype.h>' macros use per-file static |
Set ROP to the greatest common divisor of OP1 and OP2. The result |
variables and may not be reentrant, depending whether the compiler |
is always positive even if either of or both input operands are |
optimizes away fetches from them. The GMP text-based input |
negative. |
functions are affected. |
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- Function: unsigned long int mpz_gcd_ui (mpz_t ROP, mpz_t OP1, |
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unsigned long int OP2) |
File: gmp.info, Node: Useful Macros and Constants, Next: Compatibility with older versions, Prev: Reentrancy, Up: GMP Basics |
Compute the greatest common divisor of OP1 and OP2. If ROP is not |
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`NULL', store the result there. |
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If the result is small enough to fit in an `unsigned long int', it |
Useful Macros and Constants |
is returned. If the result does not fit, 0 is returned, and the |
=========================== |
result is equal to the argument OP1. Note that the result will |
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always fit if OP2 is non-zero. |
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- Function: void mpz_gcdext (mpz_t G, mpz_t S, mpz_t T, mpz_t A, mpz_t |
- Global Constant: const int mp_bits_per_limb |
B) |
The number of bits per limb. |
Compute G, S, and T, such that AS + BT = G = `gcd'(A, B). If T is |
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`NULL', that argument is not computed. |
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- Function: void mpz_lcm (mpz_t ROP, mpz_t OP1, mpz_t OP2) |
- Macro: __GNU_MP_VERSION |
Set ROP to the least common multiple of OP1 and OP2. |
- Macro: __GNU_MP_VERSION_MINOR |
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- Macro: __GNU_MP_VERSION_PATCHLEVEL |
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The major and minor GMP version, and patch level, respectively, as |
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integers. For GMP i.j, these numbers will be i, j, and 0, |
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respectively. For GMP i.j.k, these numbers will be i, j, and k, |
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respectively. |
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- Function: int mpz_invert (mpz_t ROP, mpz_t OP1, mpz_t OP2) |
- Global Constant: const char * const gmp_version |
Compute the inverse of OP1 modulo OP2 and put the result in ROP. |
The GMP version number, as a null-terminated string, in the form |
Return non-zero if an inverse exists, zero otherwise. When the |
"i.j" or "i.j.k". This release is "4.1.2". |
function returns zero, ROP is undefined. |
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- Function: int mpz_jacobi (mpz_t OP1, mpz_t OP2) |
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- Function: int mpz_legendre (mpz_t OP1, mpz_t OP2) |
File: gmp.info, Node: Compatibility with older versions, Next: Demonstration Programs, Prev: Useful Macros and Constants, Up: GMP Basics |
Compute the Jacobi and Legendre symbols, respectively. OP2 should |
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be odd and must be positive. |
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- Function: int mpz_si_kronecker (long A, mpz_t B); |
Compatibility with older versions |
- Function: int mpz_ui_kronecker (unsigned long A, mpz_t B); |
================================= |
- Function: int mpz_kronecker_si (mpz_t A, long B); |
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- Function: int mpz_kronecker_ui (mpz_t A, unsigned long B); |
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Calculate the value of the Kronecker/Jacobi symbol (A/B), with the |
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Kronecker extension (a/2)=(2/a) when a odd, or (a/2)=0 when a even. |
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All values of A and B give a well-defined result. See Henri |
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Cohen, section 1.4.2, for more information (*note References::). |
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See also the example program `demos/qcn.c' which uses |
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`mpz_kronecker_ui'. |
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- Function: unsigned long int mpz_remove (mpz_t ROP, mpz_t OP, mpz_t F) |
This version of GMP is upwardly binary compatible with all 4.x and |
Remove all occurrences of the factor F from OP and store the |
3.x versions, and upwardly compatible at the source level with all 2.x |
result in ROP. Return the multiplicity of F in OP. |
versions, with the following exceptions. |
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- Function: void mpz_fac_ui (mpz_t ROP, unsigned long int OP) |
* `mpn_gcd' had its source arguments swapped as of GMP 3.0, for |
Set ROP to OP!, the factorial of OP. |
consistency with other `mpn' functions. |
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- Function: void mpz_bin_ui (mpz_t ROP, mpz_t N, unsigned long int K) |
* `mpf_get_prec' counted precision slightly differently in GMP 3.0 |
- Function: void mpz_bin_uiui (mpz_t ROP, unsigned long int N, |
and 3.0.1, but in 3.1 reverted to the 2.x style. |
unsigned long int K) |
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Compute the binomial coefficient N over K and store the result in |
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ROP. Negative values of N are supported by `mpz_bin_ui', using |
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the identity bin(-n,k) = (-1)^k * bin(n+k-1,k) (see Knuth volume 1 |
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section 1.2.6 part G). |
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- Function: void mpz_fib_ui (mpz_t ROP, unsigned long int N) |
There are a number of compatibility issues between GMP 1 and GMP 2 |
Compute the Nth Fibonacci number and store the result in ROP. |
that of course also apply when porting applications from GMP 1 to GMP |
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4. Please see the GMP 2 manual for details. |
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The Berkeley MP compatibility library (*note BSD Compatible |
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Functions::) is source and binary compatible with the standard `libmp'. |
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File: gmp.info, Node: Integer Comparisons, Next: Integer Logic and Bit Fiddling, Prev: Number Theoretic Functions, Up: Integer Functions |
File: gmp.info, Node: Demonstration Programs, Next: Efficiency, Prev: Compatibility with older versions, Up: GMP Basics |
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Comparison Functions |
Demonstration programs |
==================== |
====================== |
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- Function: int mpz_cmp (mpz_t OP1, mpz_t OP2) |
The `demos' subdirectory has some sample programs using GMP. These |
Compare OP1 and OP2. Return a positive value if OP1 > OP2, zero |
aren't built or installed, but there's a `Makefile' with rules for them. |
if OP1 = OP2, and a negative value if OP1 < OP2. |
For instance, |
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- Macro: int mpz_cmp_ui (mpz_t OP1, unsigned long int OP2) |
make pexpr |
- Macro: int mpz_cmp_si (mpz_t OP1, signed long int OP2) |
./pexpr 68^975+10 |
Compare OP1 and OP2. Return a positive value if OP1 > OP2, zero |
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if OP1 = OP2, and a negative value if OP1 < OP2. |
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These functions are actually implemented as macros. They evaluate |
The following programs are provided |
their arguments multiple times. |
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- Function: int mpz_cmpabs (mpz_t OP1, mpz_t OP2) |
* `pexpr' is an expression evaluator, the program used on the GMP |
- Function: int mpz_cmpabs_ui (mpz_t OP1, unsigned long int OP2) |
web page. |
Compare the absolute values of OP1 and OP2. Return a positive |
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value if OP1 > OP2, zero if OP1 = OP2, and a negative value if OP1 |
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< OP2. |
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- Macro: int mpz_sgn (mpz_t OP) |
* The `calc' subdirectory has a similar but simpler evaluator using |
Return +1 if OP > 0, 0 if OP = 0, and -1 if OP < 0. |
`lex' and `yacc'. |
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This function is actually implemented as a macro. It evaluates its |
* The `expr' subdirectory is yet another expression evaluator, a |
arguments multiple times. |
library designed for ease of use within a C program. See |
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`demos/expr/README' for more information. |
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* `factorize' is a Pollard-Rho factorization program. |
File: gmp.info, Node: Integer Logic and Bit Fiddling, Next: I/O of Integers, Prev: Integer Comparisons, Up: Integer Functions |
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Logical and Bit Manipulation Functions |
* `isprime' is a command-line interface to the `mpz_probab_prime_p' |
====================================== |
function. |
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These functions behave as if two's complement arithmetic were used |
* `primes' counts or lists primes in an interval, using a sieve. |
(although sign-magnitude is used by the actual implementation). |
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- Function: void mpz_and (mpz_t ROP, mpz_t OP1, mpz_t OP2) |
* `qcn' is an example use of `mpz_kronecker_ui' to estimate quadratic |
Set ROP to OP1 logical-and OP2. |
class numbers. |
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- Function: void mpz_ior (mpz_t ROP, mpz_t OP1, mpz_t OP2) |
* The `perl' subdirectory is a comprehensive perl interface to GMP. |
Set ROP to OP1 inclusive-or OP2. |
See `demos/perl/INSTALL' for more information. Documentation is |
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in POD format in `demos/perl/GMP.pm'. |
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- Function: void mpz_xor (mpz_t ROP, mpz_t OP1, mpz_t OP2) |
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Set ROP to OP1 exclusive-or OP2. |
File: gmp.info, Node: Efficiency, Next: Debugging, Prev: Demonstration Programs, Up: GMP Basics |
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- Function: void mpz_com (mpz_t ROP, mpz_t OP) |
Efficiency |
Set ROP to the one's complement of OP. |
========== |
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- Function: unsigned long int mpz_popcount (mpz_t OP) |
Small operands |
For non-negative numbers, return the population count of OP. For |
On small operands, the time for function call overheads and memory |
negative numbers, return the largest possible value (MAX_ULONG). |
allocation can be significant in comparison to actual calculation. |
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This is unavoidable in a general purpose variable precision |
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library, although GMP attempts to be as efficient as it can on |
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both large and small operands. |
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- Function: unsigned long int mpz_hamdist (mpz_t OP1, mpz_t OP2) |
Static Linking |
If OP1 and OP2 are both non-negative, return the hamming distance |
On some CPUs, in particular the x86s, the static `libgmp.a' should |
between the two operands. Otherwise, return the largest possible |
be used for maximum speed, since the PIC code in the shared |
value (MAX_ULONG). |
`libgmp.so' will have a small overhead on each function call and |
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global data address. For many programs this will be |
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insignificant, but for long calculations there's a gain to be had. |
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It is possible to extend this function to return a useful value |
Initializing and clearing |
when the operands are both negative, but the current |
Avoid excessive initializing and clearing of variables, since this |
implementation returns MAX_ULONG in this case. *Do not depend on |
can be quite time consuming, especially in comparison to otherwise |
this behavior, since it will change in a future release.* |
fast operations like addition. |
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- Function: unsigned long int mpz_scan0 (mpz_t OP, unsigned long int |
A language interpreter might want to keep a free list or stack of |
STARTING_BIT) |
initialized variables ready for use. It should be possible to |
Scan OP, starting with bit STARTING_BIT, towards more significant |
integrate something like that with a garbage collector too. |
bits, until the first clear bit is found. Return the index of the |
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found bit. |
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- Function: unsigned long int mpz_scan1 (mpz_t OP, unsigned long int |
Reallocations |
STARTING_BIT) |
An `mpz_t' or `mpq_t' variable used to hold successively increasing |
Scan OP, starting with bit STARTING_BIT, towards more significant |
values will have its memory repeatedly `realloc'ed, which could be |
bits, until the first set bit is found. Return the index of the |
quite slow or could fragment memory, depending on the C library. |
found bit. |
If an application can estimate the final size then `mpz_init2' or |
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`mpz_realloc2' can be called to allocate the necessary space from |
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the beginning (*note Initializing Integers::). |
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- Function: void mpz_setbit (mpz_t ROP, unsigned long int BIT_INDEX) |
It doesn't matter if a size set with `mpz_init2' or `mpz_realloc2' |
Set bit BIT_INDEX in ROP. |
is too small, since all functions will do a further reallocation |
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if necessary. Badly overestimating memory required will waste |
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space though. |
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- Function: void mpz_clrbit (mpz_t ROP, unsigned long int BIT_INDEX) |
`2exp' functions |
Clear bit BIT_INDEX in ROP. |
It's up to an application to call functions like `mpz_mul_2exp' |
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when appropriate. General purpose functions like `mpz_mul' make |
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no attempt to identify powers of two or other special forms, |
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because such inputs will usually be very rare and testing every |
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time would be wasteful. |
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- Function: int mpz_tstbit (mpz_t OP, unsigned long int BIT_INDEX) |
`ui' and `si' functions |
Check bit BIT_INDEX in OP and return 0 or 1 accordingly. |
The `ui' functions and the small number of `si' functions exist for |
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convenience and should be used where applicable. But if for |
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example an `mpz_t' contains a value that fits in an `unsigned |
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long' there's no need extract it and call a `ui' function, just |
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use the regular `mpz' function. |
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In-Place Operations |
File: gmp.info, Node: I/O of Integers, Next: Integer Random Numbers, Prev: Integer Logic and Bit Fiddling, Up: Integer Functions |
`mpz_abs', `mpq_abs', `mpf_abs', `mpz_neg', `mpq_neg' and |
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`mpf_neg' are fast when used for in-place operations like |
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`mpz_abs(x,x)', since in the current implementation only a single |
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field of `x' needs changing. On suitable compilers (GCC for |
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instance) this is inlined too. |
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Input and Output Functions |
`mpz_add_ui', `mpz_sub_ui', `mpf_add_ui' and `mpf_sub_ui' benefit |
========================== |
from an in-place operation like `mpz_add_ui(x,x,y)', since usually |
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only one or two limbs of `x' will need to be changed. The same |
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applies to the full precision `mpz_add' etc if `y' is small. If |
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`y' is big then cache locality may be helped, but that's all. |
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Functions that perform input from a stdio stream, and functions that |
`mpz_mul' is currently the opposite, a separate destination is |
output to a stdio stream. Passing a `NULL' pointer for a STREAM |
slightly better. A call like `mpz_mul(x,x,y)' will, unless `y' is |
argument to any of these functions will make them read from `stdin' and |
only one limb, make a temporary copy of `x' before forming the |
write to `stdout', respectively. |
result. Normally that copying will only be a tiny fraction of the |
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time for the multiply, so this is not a particularly important |
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consideration. |
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When using any of these functions, it is a good idea to include |
`mpz_set', `mpq_set', `mpq_set_num', `mpf_set', etc, make no |
`stdio.h' before `gmp.h', since that will allow `gmp.h' to define |
attempt to recognise a copy of something to itself, so a call like |
prototypes for these functions. |
`mpz_set(x,x)' will be wasteful. Naturally that would never be |
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written deliberately, but if it might arise from two pointers to |
|
the same object then a test to avoid it might be desirable. |
|
|
- Function: size_t mpz_out_str (FILE *STREAM, int BASE, mpz_t OP) |
if (x != y) |
Output OP on stdio stream STREAM, as a string of digits in base |
mpz_set (x, y); |
BASE. The base may vary from 2 to 36. |
|
|
|
Return the number of bytes written, or if an error occurred, |
Note that it's never worth introducing extra `mpz_set' calls just |
return 0. |
to get in-place operations. If a result should go to a particular |
|
variable then just direct it there and let GMP take care of data |
|
movement. |
|
|
- Function: size_t mpz_inp_str (mpz_t ROP, FILE *STREAM, int BASE) |
Divisibility Testing (Small Integers) |
Input a possibly white-space preceded string in base BASE from |
`mpz_divisible_ui_p' and `mpz_congruent_ui_p' are the best |
stdio stream STREAM, and put the read integer in ROP. The base |
functions for testing whether an `mpz_t' is divisible by an |
may vary from 2 to 36. If BASE is 0, the actual base is |
individual small integer. They use an algorithm which is faster |
determined from the leading characters: if the first two |
than `mpz_tdiv_ui', but which gives no useful information about |
characters are `0x' or `0X', hexadecimal is assumed, otherwise if |
the actual remainder, only whether it's zero (or a particular |
the first character is `0', octal is assumed, otherwise decimal is |
value). |
assumed. |
|
|
|
Return the number of bytes read, or if an error occurred, return 0. |
However when testing divisibility by several small integers, it's |
|
best to take a remainder modulo their product, to save |
|
multi-precision operations. For instance to test whether a number |
|
is divisible by any of 23, 29 or 31 take a remainder modulo |
|
23*29*31 = 20677 and then test that. |
|
|
- Function: size_t mpz_out_raw (FILE *STREAM, mpz_t OP) |
The division functions like `mpz_tdiv_q_ui' which give a quotient |
Output OP on stdio stream STREAM, in raw binary format. The |
as well as a remainder are generally a little slower than the |
integer is written in a portable format, with 4 bytes of size |
remainder-only functions like `mpz_tdiv_ui'. If the quotient is |
information, and that many bytes of limbs. Both the size and the |
only rarely wanted then it's probably best to just take a |
limbs are written in decreasing significance order (i.e., in |
remainder and then go back and calculate the quotient if and when |
big-endian). |
it's wanted (`mpz_divexact_ui' can be used if the remainder is |
|
zero). |
|
|
The output can be read with `mpz_inp_raw'. |
Rational Arithmetic |
|
The `mpq' functions operate on `mpq_t' values with no common |
|
factors in the numerator and denominator. Common factors are |
|
checked-for and cast out as necessary. In general, cancelling |
|
factors every time is the best approach since it minimizes the |
|
sizes for subsequent operations. |
|
|
Return the number of bytes written, or if an error occurred, |
However, applications that know something about the factorization |
return 0. |
of the values they're working with might be able to avoid some of |
|
the GCDs used for canonicalization, or swap them for divisions. |
|
For example when multiplying by a prime it's enough to check for |
|
factors of it in the denominator instead of doing a full GCD. Or |
|
when forming a big product it might be known that very little |
|
cancellation will be possible, and so canonicalization can be left |
|
to the end. |
|
|
The output of this can not be read by `mpz_inp_raw' from GMP 1, |
The `mpq_numref' and `mpq_denref' macros give access to the |
because of changes necessary for compatibility between 32-bit and |
numerator and denominator to do things outside the scope of the |
64-bit machines. |
supplied `mpq' functions. *Note Applying Integer Functions::. |
|
|
- Function: size_t mpz_inp_raw (mpz_t ROP, FILE *STREAM) |
The canonical form for rationals allows mixed-type `mpq_t' and |
Input from stdio stream STREAM in the format written by |
integer additions or subtractions to be done directly with |
`mpz_out_raw', and put the result in ROP. Return the number of |
multiples of the denominator. This will be somewhat faster than |
bytes read, or if an error occurred, return 0. |
`mpq_add'. For example, |
|
|
This routine can read the output from `mpz_out_raw' also from GMP |
/* mpq increment */ |
1, in spite of changes necessary for compatibility between 32-bit |
mpz_add (mpq_numref(q), mpq_numref(q), mpq_denref(q)); |
and 64-bit machines. |
|
|
/* mpq += unsigned long */ |
|
mpz_addmul_ui (mpq_numref(q), mpq_denref(q), 123UL); |
|
|
|
/* mpq -= mpz */ |
|
mpz_submul (mpq_numref(q), mpq_denref(q), z); |
|
|
|
Number Sequences |
File: gmp.info, Node: Integer Random Numbers, Next: Miscellaneous Integer Functions, Prev: I/O of Integers, Up: Integer Functions |
Functions like `mpz_fac_ui', `mpz_fib_ui' and `mpz_bin_uiui' are |
|
designed for calculating isolated values. If a range of values is |
|
wanted it's probably best to call to get a starting point and |
|
iterate from there. |
|
|
Random Number Functions |
Text Input/Output |
======================= |
Hexadecimal or octal are suggested for input or output in text |
|
form. Power-of-2 bases like these can be converted much more |
|
efficiently than other bases, like decimal. For big numbers |
|
there's usually nothing of particular interest to be seen in the |
|
digits, so the base doesn't matter much. |
|
|
The random number functions of GMP come in two groups; older function |
Maybe we can hope octal will one day become the normal base for |
that rely on a global state, and newer functions that accept a state |
everyday use, as proposed by King Charles XII of Sweden and later |
parameter that is read and modified. Please see the *Note Random |
reformers. |
Number Functions:: for more information on how to use and not to use |
|
random number functions. |
|
|
|
- Function: void mpz_urandomb (mpz_t ROP, gmp_randstate_t STATE, |
|
unsigned long int N) Generate a uniformly distributed random |
File: gmp.info, Node: Debugging, Next: Profiling, Prev: Efficiency, Up: GMP Basics |
integer in the range 0 to 2^N - 1, inclusive. |
|
|
|
The variable STATE must be initialized by calling one of the |
Debugging |
`gmp_randinit' functions (*Note Random State Initialization::) |
========= |
before invoking this function. |
|
|
|
- Function: void mpz_urandomm (mpz_t ROP, gmp_randstate_t STATE, |
Stack Overflow |
mpz_t N) Generate a uniform random integer in the range 0 to N - |
Depending on the system, a segmentation violation or bus error |
1, inclusive. |
might be the only indication of stack overflow. See |
|
`--enable-alloca' choices in *Note Build Options::, for how to |
|
address this. |
|
|
The variable STATE must be initialized by calling one of the |
In new enough versions of GCC, `-fstack-check' may be able to |
`gmp_randinit' functions (*Note Random State Initialization::) |
ensure an overflow is recognised by the system before too much |
before invoking this function. |
damage is done, or `-fstack-limit-symbol' or |
|
`-fstack-limit-register' may be able to add checking if the system |
|
itself doesn't do any (*note Options for Code Generation: |
|
(gcc)Code Gen Options.). These options must be added to the |
|
`CFLAGS' used in the GMP build (*note Build Options::), adding |
|
them just to an application will have no effect. Note also |
|
they're a slowdown, adding overhead to each function call and each |
|
stack allocation. |
|
|
- Function: void mpz_rrandomb (mpz_t ROP, gmp_randstate_t STATE, |
Heap Problems |
unsigned long int N) |
The most likely cause of application problems with GMP is heap |
Generate a random integer with long strings of zeros and ones in |
corruption. Failing to `init' GMP variables will have |
the binary representation. Useful for testing functions and |
unpredictable effects, and corruption arising elsewhere in a |
algorithms, since this kind of random numbers have proven to be |
program may well affect GMP. Initializing GMP variables more than |
more likely to trigger corner-case bugs. The random number will |
once or failing to clear them will cause memory leaks. |
be in the range 0 to 2^N - 1, inclusive. |
|
|
|
The variable STATE must be initialized by calling one of the |
In all such cases a malloc debugger is recommended. On a GNU or |
`gmp_randinit' functions (*Note Random State Initialization::) |
BSD system the standard C library `malloc' has some diagnostic |
before invoking this function. |
facilities, see *Note Allocation Debugging: (libc)Allocation |
|
Debugging, or `man 3 malloc'. Other possibilities, in no |
|
particular order, include |
|
|
- Function: void mpz_random (mpz_t ROP, mp_size_t MAX_SIZE) |
`http://www.inf.ethz.ch/personal/biere/projects/ccmalloc' |
Generate a random integer of at most MAX_SIZE limbs. The generated |
`http://quorum.tamu.edu/jon/gnu' (debauch) |
random number doesn't satisfy any particular requirements of |
`http://dmalloc.com' |
randomness. Negative random numbers are generated when MAX_SIZE |
`http://www.perens.com/FreeSoftware' (electric fence) |
is negative. |
`http://packages.debian.org/fda' |
|
`http://www.gnupdate.org/components/leakbug' |
|
`http://people.redhat.com/~otaylor/memprof' |
|
`http://www.cbmamiga.demon.co.uk/mpatrol' |
|
|
This function is obsolete. Use `mpz_urandomb' or `mpz_urandomm' |
The GMP default allocation routines in `memory.c' also have a |
instead. |
simple sentinel scheme which can be enabled with `#define DEBUG' |
|
in that file. This is mainly designed for detecting buffer |
|
overruns during GMP development, but might find other uses. |
|
|
- Function: void mpz_random2 (mpz_t ROP, mp_size_t MAX_SIZE) |
Stack Backtraces |
Generate a random integer of at most MAX_SIZE limbs, with long |
On some systems the compiler options GMP uses by default can |
strings of zeros and ones in the binary representation. Useful |
interfere with debugging. In particular on x86 and 68k systems |
for testing functions and algorithms, since this kind of random |
`-fomit-frame-pointer' is used and this generally inhibits stack |
numbers have proven to be more likely to trigger corner-case bugs. |
backtracing. Recompiling without such options may help while |
Negative random numbers are generated when MAX_SIZE is negative. |
debugging, though the usual caveats about it potentially moving a |
|
memory problem or hiding a compiler bug will apply. |
|
|
This function is obsolete. Use `mpz_rrandomb' instead. |
GNU Debugger |
|
A sample `.gdbinit' is included in the distribution, showing how |
|
to call some undocumented dump functions to print GMP variables |
|
from within GDB. Note that these functions shouldn't be used in |
|
final application code since they're undocumented and may be |
|
subject to incompatible changes in future versions of GMP. |
|
|
|
Source File Paths |
File: gmp.info, Node: Miscellaneous Integer Functions, Prev: Integer Random Numbers, Up: Integer Functions |
GMP has multiple source files with the same name, in different |
|
directories. For example `mpz', `mpq', `mpf' and `mpfr' each have |
|
an `init.c'. If the debugger can't already determine the right |
|
one it may help to build with absolute paths on each C file. One |
|
way to do that is to use a separate object directory with an |
|
absolute path to the source directory. |
|
|
Miscellaneous Functions |
cd /my/build/dir |
======================= |
/my/source/dir/gmp-4.1.2/configure |
|
|
- Function: int mpz_fits_ulong_p (mpz_t OP) |
This works via `VPATH', and might require GNU `make'. Alternately |
- Function: int mpz_fits_slong_p (mpz_t OP) |
it might be possible to change the `.c.lo' rules appropriately. |
- Function: int mpz_fits_uint_p (mpz_t OP) |
|
- Function: int mpz_fits_sint_p (mpz_t OP) |
|
- Function: int mpz_fits_ushort_p (mpz_t OP) |
|
- Function: int mpz_fits_sshort_p (mpz_t OP) |
|
Return non-zero iff the value of OP fits in an `unsigned long int', |
|
`signed long int', `unsigned int', `signed int', `unsigned short |
|
int', or `signed short int', respectively. Otherwise, return zero. |
|
|
|
- Macro: int mpz_odd_p (mpz_t OP) |
Assertion Checking |
- Macro: int mpz_even_p (mpz_t OP) |
The build option `--enable-assert' is available to add some |
Determine whether OP is odd or even, respectively. Return |
consistency checks to the library (see *Note Build Options::). |
non-zero if yes, zero if no. These macros evaluate their |
These are likely to be of limited value to most applications. |
arguments more than once. |
Assertion failures are just as likely to indicate memory |
|
corruption as a library or compiler bug. |
|
|
- Function: size_t mpz_size (mpz_t OP) |
Applications using the low-level `mpn' functions, however, will |
Return the size of OP measured in number of limbs. If OP is zero, |
benefit from `--enable-assert' since it adds checks on the |
the returned value will be zero. |
parameters of most such functions, many of which have subtle |
|
restrictions on their usage. Note however that only the generic C |
|
code has checks, not the assembler code, so CPU `none' should be |
|
used for maximum checking. |
|
|
- Function: size_t mpz_sizeinbase (mpz_t OP, int BASE) |
Temporary Memory Checking |
Return the size of OP measured in number of digits in base BASE. |
The build option `--enable-alloca=debug' arranges that each block |
The base may vary from 2 to 36. The returned value will be exact |
of temporary memory in GMP is allocated with a separate call to |
or 1 too big. If BASE is a power of 2, the returned value will |
`malloc' (or the allocation function set with |
always be exact. |
`mp_set_memory_functions'). |
|
|
This function is useful in order to allocate the right amount of |
This can help a malloc debugger detect accesses outside the |
space before converting OP to a string. The right amount of |
intended bounds, or detect memory not released. In a normal |
allocation is normally two more than the value returned by |
build, on the other hand, temporary memory is allocated in blocks |
`mpz_sizeinbase' (one extra for a minus sign and one for the |
which GMP divides up for its own use, or may be allocated with a |
terminating '\0'). |
compiler builtin `alloca' which will go nowhere near any malloc |
|
debugger hooks. |
|
|
|
Maximum Debuggability |
File: gmp.info, Node: Rational Number Functions, Next: Floating-point Functions, Prev: Integer Functions, Up: Top |
To summarize the above, a GMP build for maximum debuggability |
|
would be |
|
|
Rational Number Functions |
./configure --disable-shared --enable-assert \ |
************************* |
--enable-alloca=debug --host=none CFLAGS=-g |
|
|
This chapter describes the GMP functions for performing arithmetic |
For C++, add `--enable-cxx CXXFLAGS=-g'. |
on rational numbers. These functions start with the prefix `mpq_'. |
|
|
|
Rational numbers are stored in objects of type `mpq_t'. |
Checker |
|
The checker program (`http://savannah.gnu.org/projects/checker') |
|
can be used with GMP. It contains a stub library which means GMP |
|
applications compiled with checker can use a normal GMP build. |
|
|
All rational arithmetic functions assume operands have a canonical |
A build of GMP with checking within GMP itself can be made. This |
form, and canonicalize their result. The canonical from means that the |
will run very very slowly. Configure with |
denominator and the numerator have no common factors, and that the |
|
denominator is positive. Zero has the unique representation 0/1. |
|
|
|
Pure assignment functions do not canonicalize the assigned variable. |
./configure --host=none-pc-linux-gnu CC=checkergcc |
It is the responsibility of the user to canonicalize the assigned |
|
variable before any arithmetic operations are performed on that |
|
variable. *Note that this is an incompatible change from version 1 of |
|
the library.* |
|
|
|
- Function: void mpq_canonicalize (mpq_t OP) |
`--host=none' must be used, since the GMP assembler code doesn't |
Remove any factors that are common to the numerator and |
support the checking scheme. The GMP C++ features cannot be used, |
denominator of OP, and make the denominator positive. |
since current versions of checker (0.9.9.1) don't yet support the |
|
standard C++ library. |
|
|
* Menu: |
Valgrind |
|
The valgrind program (`http://devel-home.kde.org/~sewardj') is a |
|
memory checker for x86s. It translates and emulates machine |
|
instructions to do strong checks for uninitialized data (at the |
|
level of individual bits), memory accesses through bad pointers, |
|
and memory leaks. |
|
|
* Initializing Rationals:: |
Current versions (20020226 snapshot) don't support MMX or SSE, so |
* Rational Arithmetic:: |
GMP must be configured for an x86 without those (eg. plain |
* Comparing Rationals:: |
`i386'), or with a special `MPN_PATH' that excludes those |
* Applying Integer Functions:: |
subdirectories (*note Build Options::). |
* I/O of Rationals:: |
|
* Miscellaneous Rational Functions:: |
|
|
|
|
Other Problems |
|
Any suspected bug in GMP itself should be isolated to make sure |
|
it's not an application problem, see *Note Reporting Bugs::. |
|
|
|
|
File: gmp.info, Node: Initializing Rationals, Next: Rational Arithmetic, Prev: Rational Number Functions, Up: Rational Number Functions |
File: gmp.info, Node: Profiling, Next: Autoconf, Prev: Debugging, Up: GMP Basics |
|
|
Initialization and Assignment Functions |
Profiling |
======================================= |
========= |
|
|
- Function: void mpq_init (mpq_t DEST_RATIONAL) |
Running a program under a profiler is a good way to find where it's |
Initialize DEST_RATIONAL and set it to 0/1. Each variable should |
spending most time and where improvements can be best sought. |
normally only be initialized once, or at least cleared out (using |
|
the function `mpq_clear') between each initialization. |
|
|
|
- Function: void mpq_clear (mpq_t RATIONAL_NUMBER) |
Depending on the system, it may be possible to get a flat profile, |
Free the space occupied by RATIONAL_NUMBER. Make sure to call this |
meaning simple timer sampling of the program counter, with no special |
function for all `mpq_t' variables when you are done with them. |
GMP build options, just a `-p' when compiling the mainline. This is a |
|
good way to ensure minimum interference with normal operation. The |
|
necessary symbol type and size information exists in most of the GMP |
|
assembler code. |
|
|
- Function: void mpq_set (mpq_t ROP, mpq_t OP) |
The `--enable-profiling' build option can be used to add suitable |
- Function: void mpq_set_z (mpq_t ROP, mpz_t OP) |
compiler flags, either for `prof' (`-p') or `gprof' (`-pg'), see *Note |
Assign ROP from OP. |
Build Options::. Which of the two is available and what they do will |
|
depend on the system, and possibly on support available in `libc'. For |
|
some systems appropriate corresponding `mcount' calls are added to the |
|
assembler code too. |
|
|
- Function: void mpq_set_ui (mpq_t ROP, unsigned long int OP1, |
On x86 systems `prof' gives call counting, so that average time spent |
unsigned long int OP2) |
in a function can be determined. `gprof', where supported, adds call |
- Function: void mpq_set_si (mpq_t ROP, signed long int OP1, unsigned |
graph construction, so for instance calls to `mpn_add_n' from `mpz_add' |
long int OP2) |
and from `mpz_mul' can be differentiated. |
Set the value of ROP to OP1/OP2. Note that if OP1 and OP2 have |
|
common factors, ROP has to be passed to `mpq_canonicalize' before |
|
any operations are performed on ROP. |
|
|
|
- Function: void mpq_swap (mpq_t ROP1, mpq_t ROP2) |
On x86 and 68k systems `-pg' and `-fomit-frame-pointer' are |
Swap the values ROP1 and ROP2 efficiently. |
incompatible, so the latter is not used when `gprof' profiling is |
|
selected, which may result in poorer code generation. If `prof' |
|
profiling is selected instead it should still be possible to use |
|
`gprof', but only the `gprof -p' flat profile and call counts can be |
|
expected to be valid, not the `gprof -q' call graph. |
|
|
|
|
File: gmp.info, Node: Rational Arithmetic, Next: Comparing Rationals, Prev: Initializing Rationals, Up: Rational Number Functions |
File: gmp.info, Node: Autoconf, Next: Emacs, Prev: Profiling, Up: GMP Basics |
|
|
Arithmetic Functions |
Autoconf |
==================== |
======== |
|
|
- Function: void mpq_add (mpq_t SUM, mpq_t ADDEND1, mpq_t ADDEND2) |
Autoconf based applications can easily check whether GMP is |
Set SUM to ADDEND1 + ADDEND2. |
installed. The only thing to be noted is that GMP library symbols from |
|
version 3 onwards have prefixes like `__gmpz'. The following therefore |
|
would be a simple test, |
|
|
- Function: void mpq_sub (mpq_t DIFFERENCE, mpq_t MINUEND, mpq_t |
AC_CHECK_LIB(gmp, __gmpz_init) |
SUBTRAHEND) |
|
Set DIFFERENCE to MINUEND - SUBTRAHEND. |
|
|
|
- Function: void mpq_mul (mpq_t PRODUCT, mpq_t MULTIPLIER, mpq_t |
This just uses the default `AC_CHECK_LIB' actions for found or not |
MULTIPLICAND) |
found, but an application that must have GMP would want to generate an |
Set PRODUCT to MULTIPLIER times MULTIPLICAND. |
error if not found. For example, |
|
|
- Function: void mpq_div (mpq_t QUOTIENT, mpq_t DIVIDEND, mpq_t |
AC_CHECK_LIB(gmp, __gmpz_init, , [AC_MSG_ERROR( |
DIVISOR) |
[GNU MP not found, see http://swox.com/gmp])]) |
Set QUOTIENT to DIVIDEND/DIVISOR. |
|
|
|
- Function: void mpq_neg (mpq_t NEGATED_OPERAND, mpq_t OPERAND) |
If functions added in some particular version of GMP are required, |
Set NEGATED_OPERAND to -OPERAND. |
then one of those can be used when checking. For example `mpz_mul_si' |
|
was added in GMP 3.1, |
|
|
- Function: void mpq_inv (mpq_t INVERTED_NUMBER, mpq_t NUMBER) |
AC_CHECK_LIB(gmp, __gmpz_mul_si, , [AC_MSG_ERROR( |
Set INVERTED_NUMBER to 1/NUMBER. If the new denominator is zero, |
[GNU MP not found, or not 3.1 or up, see http://swox.com/gmp])]) |
this routine will divide by zero. |
|
|
|
|
An alternative would be to test the version number in `gmp.h' using |
File: gmp.info, Node: Comparing Rationals, Next: Applying Integer Functions, Prev: Rational Arithmetic, Up: Rational Number Functions |
say `AC_EGREP_CPP'. That would make it possible to test the exact |
|
version, if some particular sub-minor release is known to be necessary. |
|
|
Comparison Functions |
An application that can use either GMP 2 or 3 will need to test for |
==================== |
`__gmpz_init' (GMP 3 and up) or `mpz_init' (GMP 2), and it's also worth |
|
checking for `libgmp2' since Debian GNU/Linux systems used that name in |
|
the past. For example, |
|
|
- Function: int mpq_cmp (mpq_t OP1, mpq_t OP2) |
AC_CHECK_LIB(gmp, __gmpz_init, , |
Compare OP1 and OP2. Return a positive value if OP1 > OP2, zero |
[AC_CHECK_LIB(gmp, mpz_init, , |
if OP1 = OP2, and a negative value if OP1 < OP2. |
[AC_CHECK_LIB(gmp2, mpz_init)])]) |
|
|
To determine if two rationals are equal, `mpq_equal' is faster than |
In general it's suggested that applications should simply demand a |
`mpq_cmp'. |
new enough GMP rather than trying to provide supplements for features |
|
not available in past versions. |
|
|
- Macro: int mpq_cmp_ui (mpq_t OP1, unsigned long int NUM2, unsigned |
Occasionally an application will need or want to know the size of a |
long int DEN2) |
type at configuration or preprocessing time, not just with `sizeof' in |
Compare OP1 and NUM2/DEN2. Return a positive value if OP1 > |
the code. This can be done in the normal way with `mp_limb_t' etc, but |
NUM2/DEN2, zero if OP1 = NUM2/DEN2, and a negative value if OP1 < |
GMP 4.0 or up is best for this, since prior versions needed certain |
NUM2/DEN2. |
`-D' defines on systems using a `long long' limb. The following would |
|
suit Autoconf 2.50 or up, |
|
|
This routine allows that NUM2 and DEN2 have common factors. |
AC_CHECK_SIZEOF(mp_limb_t, , [#include <gmp.h>]) |
|
|
This function is actually implemented as a macro. It evaluates its |
The optional `mpfr' functions are provided in a separate |
arguments multiple times. |
`libmpfr.a', and this might be from GMP with `--enable-mpfr' or from |
|
MPFR installed separately. Either way `libmpfr' depends on `libgmp', |
|
it doesn't stand alone. Currently only a static `libmpfr.a' will be |
|
available, not a shared library, since upward binary compatibility is |
|
not guaranteed. |
|
|
- Macro: int mpq_sgn (mpq_t OP) |
AC_CHECK_LIB(mpfr, mpfr_add, , [AC_MSG_ERROR( |
Return +1 if OP > 0, 0 if OP = 0, and -1 if OP < 0. |
[Need MPFR either from GNU MP 4 or separate MPFR package. |
|
See http://www.mpfr.org or http://swox.com/gmp]) |
|
|
This function is actually implemented as a macro. It evaluates its |
|
arguments multiple times. |
File: gmp.info, Node: Emacs, Prev: Autoconf, Up: GMP Basics |
|
|
- Function: int mpq_equal (mpq_t OP1, mpq_t OP2) |
Emacs |
Return non-zero if OP1 and OP2 are equal, zero if they are |
===== |
non-equal. Although `mpq_cmp' can be used for the same purpose, |
|
this function is much faster. |
|
|
|
|
<C-h C-i> (`info-lookup-symbol') is a good way to find documentation |
File: gmp.info, Node: Applying Integer Functions, Next: I/O of Rationals, Prev: Comparing Rationals, Up: Rational Number Functions |
on C functions while editing (*note Info Documentation Lookup: |
|
(emacs)Info Lookup.). |
|
|
Applying Integer Functions to Rationals |
The GMP manual can be included in such lookups by putting the |
======================================= |
following in your `.emacs', |
|
|
The set of `mpq' functions is quite small. In particular, there are |
(eval-after-load "info-look" |
few functions for either input or output. But there are two macros |
'(let ((mode-value (assoc 'c-mode (assoc 'symbol info-lookup-alist)))) |
that allow us to apply any `mpz' function on the numerator or |
(setcar (nthcdr 3 mode-value) |
denominator of a rational number. If these macros are used to assign |
(cons '("(gmp)Function Index" nil "^ -.* " "\\>") |
to the rational number, `mpq_canonicalize' normally need to be called |
(nth 3 mode-value))))) |
afterwards. |
|
|
|
- Macro: mpz_t mpq_numref (mpq_t OP) |
The same can be done for MPFR, with `(mpfr)' in place of `(gmp)'. |
- Macro: mpz_t mpq_denref (mpq_t OP) |
|
Return a reference to the numerator and denominator of OP, |
|
respectively. The `mpz' functions can be used on the result of |
|
these macros. |
|
|
|
|
|
File: gmp.info, Node: I/O of Rationals, Next: Miscellaneous Rational Functions, Prev: Applying Integer Functions, Up: Rational Number Functions |
File: gmp.info, Node: Reporting Bugs, Next: Integer Functions, Prev: GMP Basics, Up: Top |
|
|
Input and Output Functions |
Reporting Bugs |
========================== |
************** |
|
|
Functions that perform input from a stdio stream, and functions that |
If you think you have found a bug in the GMP library, please |
output to a stdio stream. Passing a `NULL' pointer for a STREAM |
investigate it and report it. We have made this library available to |
argument to any of these functions will make them read from `stdin' and |
you, and it is not too much to ask you to report the bugs you find. |
write to `stdout', respectively. |
|
|
|
When using any of these functions, it is a good idea to include |
Before you report a bug, check it's not already addressed in *Note |
`stdio.h' before `gmp.h', since that will allow `gmp.h' to define |
Known Build Problems::, or perhaps *Note Notes for Particular |
prototypes for these functions. |
Systems::. You may also want to check `http://swox.com/gmp/' for |
|
patches for this release. |
|
|
- Function: size_t mpq_out_str (FILE *STREAM, int BASE, mpq_t OP) |
Please include the following in any report, |
Output OP on stdio stream STREAM, as a string of digits in base |
|
BASE. The base may vary from 2 to 36. Output is in the form |
|
`num/den' or if the denominator is 1 then just `num'. |
|
|
|
Return the number of bytes written, or if an error occurred, |
* The GMP version number, and if pre-packaged or patched then say so. |
return 0. |
|
|
|
|
* A test program that makes it possible for us to reproduce the bug. |
File: gmp.info, Node: Miscellaneous Rational Functions, Prev: I/O of Rationals, Up: Rational Number Functions |
Include instructions on how to run the program. |
|
|
Miscellaneous Functions |
* A description of what is wrong. If the results are incorrect, in |
======================= |
what way. If you get a crash, say so. |
|
|
- Function: double mpq_get_d (mpq_t OP) |
* If you get a crash, include a stack backtrace from the debugger if |
Convert OP to a double. |
it's informative (`where' in `gdb', or `$C' in `adb'). |
|
|
- Function: double mpq_set_d (mpq_t ROP, double D) |
* Please do not send core dumps, executables or `strace's. |
Set ROP to the value of d, without rounding. |
|
|
|
These functions assign between either the numerator or denominator |
* The configuration options you used when building GMP, if any. |
of a rational, and an integer. Instead of using these functions, it is |
|
preferable to use the more general mechanisms `mpq_numref' and |
|
`mpq_denref', together with `mpz_set'. |
|
|
|
- Function: void mpq_set_num (mpq_t RATIONAL, mpz_t NUMERATOR) |
* The name of the compiler and its version. For `gcc', get the |
Copy NUMERATOR to the numerator of RATIONAL. When this risks to |
version with `gcc -v', otherwise perhaps `what `which cc`', or |
make the numerator and denominator of RATIONAL have common |
similar. |
factors, you have to pass RATIONAL to `mpq_canonicalize' before |
|
any operations are performed on RATIONAL. |
|
|
|
This function is equivalent to `mpz_set (mpq_numref (RATIONAL), |
* The output from running `uname -a'. |
NUMERATOR)'. |
|
|
|
- Function: void mpq_set_den (mpq_t RATIONAL, mpz_t DENOMINATOR) |
* The output from running `./config.guess', and from running |
Copy DENOMINATOR to the denominator of RATIONAL. When this risks |
`./configfsf.guess' (might be the same). |
to make the numerator and denominator of RATIONAL have common |
|
factors, or if the denominator might be negative, you have to pass |
|
RATIONAL to `mpq_canonicalize' before any operations are performed |
|
on RATIONAL. |
|
|
|
*In version 1 of the library, negative denominators were handled by |
* If the bug is related to `configure', then the contents of |
copying the sign to the numerator. That is no longer done.* |
`config.log'. |
|
|
This function is equivalent to `mpz_set (mpq_denref (RATIONAL), |
* If the bug is related to an `asm' file not assembling, then the |
DENOMINATORS)'. |
contents of `config.m4' and the offending line or lines from the |
|
temporary `mpn/tmp-<file>.s'. |
|
|
- Function: void mpq_get_num (mpz_t NUMERATOR, mpq_t RATIONAL) |
Please make an effort to produce a self-contained report, with |
Copy the numerator of RATIONAL to the integer NUMERATOR, to |
something definite that can be tested or debugged. Vague queries or |
prepare for integer operations on the numerator. |
piecemeal messages are difficult to act on and don't help the |
|
development effort. |
|
|
This function is equivalent to `mpz_set (NUMERATOR, mpq_numref |
It is not uncommon that an observed problem is actually due to a bug |
(RATIONAL))'. |
in the compiler; the GMP code tends to explore interesting corners in |
|
compilers. |
|
|
- Function: void mpq_get_den (mpz_t DENOMINATOR, mpq_t RATIONAL) |
If your bug report is good, we will do our best to help you get a |
Copy the denominator of RATIONAL to the integer DENOMINATOR, to |
corrected version of the library; if the bug report is poor, we won't |
prepare for integer operations on the denominator. |
do anything about it (except maybe ask you to send a better report). |
|
|
This function is equivalent to `mpz_set (DENOMINATOR, mpq_denref |
Send your report to: <bug-gmp@gnu.org>. |
(RATIONAL))'. |
|
|
|
|
If you think something in this manual is unclear, or downright |
|
incorrect, or if the language needs to be improved, please send a note |
|
to the same address. |
|
|
|
|
File: gmp.info, Node: Floating-point Functions, Next: Low-level Functions, Prev: Rational Number Functions, Up: Top |
File: gmp.info, Node: Integer Functions, Next: Rational Number Functions, Prev: Reporting Bugs, Up: Top |
|
|
Floating-point Functions |
Integer Functions |
************************ |
***************** |
|
|
This chapter describes the GMP functions for performing floating |
This chapter describes the GMP functions for performing integer |
point arithmetic. These functions start with the prefix `mpf_'. |
arithmetic. These functions start with the prefix `mpz_'. |
|
|
GMP floating point numbers are stored in objects of type `mpf_t'. |
GMP integers are stored in objects of type `mpz_t'. |
|
|
The GMP floating-point functions have an interface that is similar |
|
to the GMP integer functions. The function prefix for floating-point |
|
operations is `mpf_'. |
|
|
|
There is one significant characteristic of floating-point numbers |
|
that has motivated a difference between this function class and other |
|
GMP function classes: the inherent inexactness of floating point |
|
arithmetic. The user has to specify the precision of each variable. A |
|
computation that assigns a variable will take place with the precision |
|
of the assigned variable; the precision of variables used as input is |
|
ignored. |
|
|
|
The precision of a calculation is defined as follows: Compute the |
|
requested operation exactly (with "infinite precision"), and truncate |
|
the result to the destination variable precision. Even if the user has |
|
asked for a very high precision, GMP will not calculate with |
|
superfluous digits. For example, if two low-precision numbers of |
|
nearly equal magnitude are added, the precision of the result will be |
|
limited to what is required to represent the result accurately. |
|
|
|
The GMP floating-point functions are _not_ intended as a smooth |
|
extension to the IEEE P754 arithmetic. Specifically, the results |
|
obtained on one computer often differs from the results obtained on a |
|
computer with a different word size. |
|
|
|
* Menu: |
* Menu: |
|
|
* Initializing Floats:: |
* Initializing Integers:: |
* Assigning Floats:: |
* Assigning Integers:: |
* Simultaneous Float Init & Assign:: |
* Simultaneous Integer Init & Assign:: |
* Converting Floats:: |
* Converting Integers:: |
* Float Arithmetic:: |
* Integer Arithmetic:: |
* Float Comparison:: |
* Integer Division:: |
* I/O of Floats:: |
* Integer Exponentiation:: |
* Miscellaneous Float Functions:: |
* Integer Roots:: |
|
* Number Theoretic Functions:: |
|
* Integer Comparisons:: |
|
* Integer Logic and Bit Fiddling:: |
|
* I/O of Integers:: |
|
* Integer Random Numbers:: |
|
* Integer Import and Export:: |
|
* Miscellaneous Integer Functions:: |
|
|
|
|
File: gmp.info, Node: Initializing Floats, Next: Assigning Floats, Prev: Floating-point Functions, Up: Floating-point Functions |
File: gmp.info, Node: Initializing Integers, Next: Assigning Integers, Prev: Integer Functions, Up: Integer Functions |
|
|
Initialization Functions |
Initialization Functions |
======================== |
======================== |
|
|
- Function: void mpf_set_default_prec (unsigned long int PREC) |
The functions for integer arithmetic assume that all integer objects |
Set the default precision to be *at least* PREC bits. All |
are initialized. You do that by calling the function `mpz_init'. For |
subsequent calls to `mpf_init' will use this precision, but |
example, |
previously initialized variables are unaffected. |
|
|
|
An `mpf_t' object must be initialized before storing the first value |
|
in it. The functions `mpf_init' and `mpf_init2' are used for that |
|
purpose. |
|
|
|
- Function: void mpf_init (mpf_t X) |
|
Initialize X to 0. Normally, a variable should be initialized |
|
once only or at least be cleared, using `mpf_clear', between |
|
initializations. The precision of X is undefined unless a default |
|
precision has already been established by a call to |
|
`mpf_set_default_prec'. |
|
|
|
- Function: void mpf_init2 (mpf_t X, unsigned long int PREC) |
|
Initialize X to 0 and set its precision to be *at least* PREC |
|
bits. Normally, a variable should be initialized once only or at |
|
least be cleared, using `mpf_clear', between initializations. |
|
|
|
- Function: void mpf_clear (mpf_t X) |
|
Free the space occupied by X. Make sure to call this function for |
|
all `mpf_t' variables when you are done with them. |
|
|
|
Here is an example on how to initialize floating-point variables: |
|
{ |
{ |
mpf_t x, y; |
mpz_t integ; |
mpf_init (x); /* use default precision */ |
mpz_init (integ); |
mpf_init2 (y, 256); /* precision _at least_ 256 bits */ |
|
... |
... |
|
mpz_add (integ, ...); |
|
... |
|
mpz_sub (integ, ...); |
|
|
/* Unless the program is about to exit, do ... */ |
/* Unless the program is about to exit, do ... */ |
mpf_clear (x); |
mpz_clear (integ); |
mpf_clear (y); |
|
} |
} |
|
|
The following three functions are useful for changing the precision |
As you can see, you can store new values any number of times, once an |
during a calculation. A typical use would be for adjusting the |
object is initialized. |
precision gradually in iterative algorithms like Newton-Raphson, making |
|
the computation precision closely match the actual accurate part of the |
|
numbers. |
|
|
|
- Function: void mpf_set_prec (mpf_t ROP, unsigned long int PREC) |
- Function: void mpz_init (mpz_t INTEGER) |
Set the precision of ROP to be *at least* PREC bits. Since |
Initialize INTEGER, and set its value to 0. |
changing the precision involves calls to `realloc', this routine |
|
should not be called in a tight loop. |
|
|
|
- Function: unsigned long int mpf_get_prec (mpf_t OP) |
- Function: void mpz_init2 (mpz_t INTEGER, unsigned long N) |
Return the precision actually used for assignments of OP. |
Initialize INTEGER, with space for N bits, and set its value to 0. |
|
|
- Function: void mpf_set_prec_raw (mpf_t ROP, unsigned long int PREC) |
N is only the initial space, INTEGER will grow automatically in |
Set the precision of ROP to be *at least* PREC bits. This is a |
the normal way, if necessary, for subsequent values stored. |
low-level function that does not change the allocation. The PREC |
`mpz_init2' makes it possible to avoid such reallocations if a |
argument must not be larger that the precision previously returned |
maximum size is known in advance. |
by `mpf_get_prec'. It is crucial that the precision of ROP is |
|
ultimately reset to exactly the value returned by `mpf_get_prec' |
|
before the first call to `mpf_set_prec_raw'. |
|
|
|
|
- Function: void mpz_clear (mpz_t INTEGER) |
|
Free the space occupied by INTEGER. Call this function for all |
|
`mpz_t' variables when you are done with them. |
|
|
|
- Function: void mpz_realloc2 (mpz_t INTEGER, unsigned long N) |
|
Change the space allocated for INTEGER to N bits. The value in |
|
INTEGER is preserved if it fits, or is set to 0 if not. |
|
|
|
This function can be used to increase the space for a variable in |
|
order to avoid repeated automatic reallocations, or to decrease it |
|
to give memory back to the heap. |
|
|
|
- Function: void mpz_array_init (mpz_t INTEGER_ARRAY[], size_t |
|
ARRAY_SIZE, mp_size_t FIXED_NUM_BITS) |
|
This is a special type of initialization. *Fixed* space of |
|
FIXED_NUM_BITS bits is allocated to each of the ARRAY_SIZE |
|
integers in INTEGER_ARRAY. |
|
|
|
The space will not be automatically increased, unlike the normal |
|
`mpz_init', but instead an application must ensure it's sufficient |
|
for any value stored. The following space requirements apply to |
|
various functions, |
|
|
|
* `mpz_abs', `mpz_neg', `mpz_set', `mpz_set_si' and |
|
`mpz_set_ui' need room for the value they store. |
|
|
|
* `mpz_add', `mpz_add_ui', `mpz_sub' and `mpz_sub_ui' need room |
|
for the larger of the two operands, plus an extra |
|
`mp_bits_per_limb'. |
|
|
|
* `mpz_mul', `mpz_mul_ui' and `mpz_mul_ui' need room for the sum |
|
of the number of bits in their operands, but each rounded up |
|
to a multiple of `mp_bits_per_limb'. |
|
|
|
* `mpz_swap' can be used between two array variables, but not |
|
between an array and a normal variable. |
|
|
|
For other functions, or if in doubt, the suggestion is to |
|
calculate in a regular `mpz_init' variable and copy the result to |
|
an array variable with `mpz_set'. |
|
|
|
`mpz_array_init' can reduce memory usage in algorithms that need |
|
large arrays of integers, since it avoids allocating and |
|
reallocating lots of small memory blocks. There is no way to free |
|
the storage allocated by this function. Don't call `mpz_clear'! |
|
|
|
- Function: void * _mpz_realloc (mpz_t INTEGER, mp_size_t NEW_ALLOC) |
|
Change the space for INTEGER to NEW_ALLOC limbs. The value in |
|
INTEGER is preserved if it fits, or is set to 0 if not. The return |
|
value is not useful to applications and should be ignored. |
|
|
|
`mpz_realloc2' is the preferred way to accomplish allocation |
|
changes like this. `mpz_realloc2' and `_mpz_realloc' are the same |
|
except that `_mpz_realloc' takes the new size in limbs. |
|
|
|
|
File: gmp.info, Node: Assigning Floats, Next: Simultaneous Float Init & Assign, Prev: Initializing Floats, Up: Floating-point Functions |
File: gmp.info, Node: Assigning Integers, Next: Simultaneous Integer Init & Assign, Prev: Initializing Integers, Up: Integer Functions |
|
|
Assignment Functions |
Assignment Functions |
==================== |
==================== |
|
|
These functions assign new values to already initialized floats |
These functions assign new values to already initialized integers |
(*note Initializing Floats::). |
(*note Initializing Integers::). |
|
|
- Function: void mpf_set (mpf_t ROP, mpf_t OP) |
- Function: void mpz_set (mpz_t ROP, mpz_t OP) |
- Function: void mpf_set_ui (mpf_t ROP, unsigned long int OP) |
- Function: void mpz_set_ui (mpz_t ROP, unsigned long int OP) |
- Function: void mpf_set_si (mpf_t ROP, signed long int OP) |
- Function: void mpz_set_si (mpz_t ROP, signed long int OP) |
- Function: void mpf_set_d (mpf_t ROP, double OP) |
- Function: void mpz_set_d (mpz_t ROP, double OP) |
- Function: void mpf_set_z (mpf_t ROP, mpz_t OP) |
- Function: void mpz_set_q (mpz_t ROP, mpq_t OP) |
- Function: void mpf_set_q (mpf_t ROP, mpq_t OP) |
- Function: void mpz_set_f (mpz_t ROP, mpf_t OP) |
Set the value of ROP from OP. |
Set the value of ROP from OP. |
|
|
- Function: int mpf_set_str (mpf_t ROP, char *STR, int BASE) |
`mpz_set_d', `mpz_set_q' and `mpz_set_f' truncate OP to make it an |
Set the value of ROP from the string in STR. The string is of the |
integer. |
form `M@N' or, if the base is 10 or less, alternatively `MeN'. |
|
`M' is the mantissa and `N' is the exponent. The mantissa is |
|
always in the specified base. The exponent is either in the |
|
specified base or, if BASE is negative, in decimal. |
|
|
|
The argument BASE may be in the ranges 2 to 36, or -36 to -2. |
- Function: int mpz_set_str (mpz_t ROP, char *STR, int BASE) |
Negative values are used to specify that the exponent is in |
Set the value of ROP from STR, a null-terminated C string in base |
decimal. |
BASE. White space is allowed in the string, and is simply |
|
ignored. The base may vary from 2 to 36. If BASE is 0, the |
|
actual base is determined from the leading characters: if the |
|
first two characters are "0x" or "0X", hexadecimal is assumed, |
|
otherwise if the first character is "0", octal is assumed, |
|
otherwise decimal is assumed. |
|
|
Unlike the corresponding `mpz' function, the base will not be |
This function returns 0 if the entire string is a valid number in |
determined from the leading characters of the string if BASE is 0. |
base BASE. Otherwise it returns -1. |
This is so that numbers like `0.23' are not interpreted as octal. |
|
|
|
White space is allowed in the string, and is simply ignored. |
[It turns out that it is not entirely true that this function |
[This is not really true; white-space is ignored in the beginning |
ignores white-space. It does ignore it between digits, but not |
of the string and within the mantissa, but not in other places, |
after a minus sign or within or after "0x". We are considering |
such as after a minus sign or in the exponent. We are considering |
|
changing the definition of this function, making it fail when |
changing the definition of this function, making it fail when |
there is any white-space in the input, since that makes a lot of |
there is any white-space in the input, since that makes a lot of |
sense. Please tell us your opinion about this change. Do you |
sense. Send your opinion of this change to <bug-gmp@gnu.org>. Do |
really want it to accept "3 14" as meaning 314 as it does now?] |
you really want it to accept "3 14" as meaning 314 as it does now?] |
|
|
This function returns 0 if the entire string up to the '\0' is a |
- Function: void mpz_swap (mpz_t ROP1, mpz_t ROP2) |
valid number in base BASE. Otherwise it returns -1. |
|
|
|
- Function: void mpf_swap (mpf_t ROP1, mpf_t ROP2) |
|
Swap the values ROP1 and ROP2 efficiently. |
Swap the values ROP1 and ROP2 efficiently. |
|
|
|
|
File: gmp.info, Node: Simultaneous Float Init & Assign, Next: Converting Floats, Prev: Assigning Floats, Up: Floating-point Functions |
File: gmp.info, Node: Simultaneous Integer Init & Assign, Next: Converting Integers, Prev: Assigning Integers, Up: Integer Functions |
|
|
Combined Initialization and Assignment Functions |
Combined Initialization and Assignment Functions |
================================================ |
================================================ |
|
|
For convenience, GMP provides a parallel series of |
For convenience, GMP provides a parallel series of |
initialize-and-set functions which initialize the output and then store |
initialize-and-set functions which initialize the output and then store |
the value there. These functions' names have the form `mpf_init_set...' |
the value there. These functions' names have the form `mpz_init_set...' |
|
|
Once the float has been initialized by any of the `mpf_init_set...' |
Here is an example of using one: |
functions, it can be used as the source or destination operand for the |
|
ordinary float functions. Don't use an initialize-and-set function on |
|
a variable already initialized! |
|
|
|
- Function: void mpf_init_set (mpf_t ROP, mpf_t OP) |
{ |
- Function: void mpf_init_set_ui (mpf_t ROP, unsigned long int OP) |
mpz_t pie; |
- Function: void mpf_init_set_si (mpf_t ROP, signed long int OP) |
mpz_init_set_str (pie, "3141592653589793238462643383279502884", 10); |
- Function: void mpf_init_set_d (mpf_t ROP, double OP) |
... |
Initialize ROP and set its value from OP. |
mpz_sub (pie, ...); |
|
... |
|
mpz_clear (pie); |
|
} |
|
|
The precision of ROP will be taken from the active default |
Once the integer has been initialized by any of the `mpz_init_set...' |
precision, as set by `mpf_set_default_prec'. |
functions, it can be used as the source or destination operand for the |
|
ordinary integer functions. Don't use an initialize-and-set function |
|
on a variable already initialized! |
|
|
- Function: int mpf_init_set_str (mpf_t ROP, char *STR, int BASE) |
- Function: void mpz_init_set (mpz_t ROP, mpz_t OP) |
Initialize ROP and set its value from the string in STR. See |
- Function: void mpz_init_set_ui (mpz_t ROP, unsigned long int OP) |
`mpf_set_str' above for details on the assignment operation. |
- Function: void mpz_init_set_si (mpz_t ROP, signed long int OP) |
|
- Function: void mpz_init_set_d (mpz_t ROP, double OP) |
|
Initialize ROP with limb space and set the initial numeric value |
|
from OP. |
|
|
Note that ROP is initialized even if an error occurs. (I.e., you |
- Function: int mpz_init_set_str (mpz_t ROP, char *STR, int BASE) |
have to call `mpf_clear' for it.) |
Initialize ROP and set its value like `mpz_set_str' (see its |
|
documentation above for details). |
|
|
The precision of ROP will be taken from the active default |
If the string is a correct base BASE number, the function returns |
precision, as set by `mpf_set_default_prec'. |
0; if an error occurs it returns -1. ROP is initialized even if |
|
an error occurs. (I.e., you have to call `mpz_clear' for it.) |
|
|
|
|
File: gmp.info, Node: Converting Floats, Next: Float Arithmetic, Prev: Simultaneous Float Init & Assign, Up: Floating-point Functions |
File: gmp.info, Node: Converting Integers, Next: Integer Arithmetic, Prev: Simultaneous Integer Init & Assign, Up: Integer Functions |
|
|
Conversion Functions |
Conversion Functions |
==================== |
==================== |
|
|
- Function: double mpf_get_d (mpf_t OP) |
This section describes functions for converting GMP integers to |
Convert OP to a double. |
standard C types. Functions for converting _to_ GMP integers are |
|
described in *Note Assigning Integers:: and *Note I/O of Integers::. |
|
|
- Function: char * mpf_get_str (char *STR, mp_exp_t *EXPPTR, int BASE, |
- Function: unsigned long int mpz_get_ui (mpz_t OP) |
size_t N_DIGITS, mpf_t OP) |
Return the value of OP as an `unsigned long'. |
Convert OP to a string of digits in base BASE. The base may vary |
|
from 2 to 36. Generate at most N_DIGITS significant digits, or if |
|
N_DIGITS is 0, the maximum number of digits accurately |
|
representable by OP. |
|
|
|
If STR is `NULL', space for the mantissa is allocated using the |
If OP is too big to fit an `unsigned long' then just the least |
default allocation function. |
significant bits that do fit are returned. The sign of OP is |
|
ignored, only the absolute value is used. |
|
|
If STR is not `NULL', it should point to a block of storage enough |
- Function: signed long int mpz_get_si (mpz_t OP) |
large for the mantissa, i.e., N_DIGITS + 2. The two extra bytes |
If OP fits into a `signed long int' return the value of OP. |
are for a possible minus sign, and for the terminating null |
Otherwise return the least significant part of OP, with the same |
character. |
sign as OP. |
|
|
The exponent is written through the pointer EXPPTR. |
If OP is too big to fit in a `signed long int', the returned |
|
result is probably not very useful. To find out if the value will |
|
fit, use the function `mpz_fits_slong_p'. |
|
|
If N_DIGITS is 0, the maximum number of digits meaningfully |
- Function: double mpz_get_d (mpz_t OP) |
achievable from the precision of OP will be generated. Note that |
Convert OP to a `double'. |
the space requirements for STR in this case will be impossible for |
|
the user to predetermine. Therefore, you need to pass `NULL' for |
|
the string argument whenever N_DIGITS is 0. |
|
|
|
The generated string is a fraction, with an implicit radix point |
- Function: double mpz_get_d_2exp (signed long int *EXP, mpz_t OP) |
immediately to the left of the first digit. For example, the |
Find D and EXP such that D times 2 raised to EXP, with |
number 3.1416 would be returned as "31416" in the string and 1 |
0.5<=abs(D)<1, is a good approximation to OP. |
written at EXPPTR. |
|
|
|
A pointer to the result string is returned. This pointer will |
- Function: char * mpz_get_str (char *STR, int BASE, mpz_t OP) |
will either equal STR, or if that is `NULL', will point to the |
Convert OP to a string of digits in base BASE. The base may vary |
allocated storage. |
from 2 to 36. |
|
|
|
If STR is `NULL', the result string is allocated using the current |
|
allocation function (*note Custom Allocation::). The block will be |
|
`strlen(str)+1' bytes, that being exactly enough for the string and |
|
null-terminator. |
|
|
|
If STR is not `NULL', it should point to a block of storage large |
|
enough for the result, that being `mpz_sizeinbase (OP, BASE) + 2'. |
|
The two extra bytes are for a possible minus sign, and the |
|
null-terminator. |
|
|
|
A pointer to the result string is returned, being either the |
|
allocated block, or the given STR. |
|
|
|
- Function: mp_limb_t mpz_getlimbn (mpz_t OP, mp_size_t N) |
|
Return limb number N from OP. The sign of OP is ignored, just the |
|
absolute value is used. The least significant limb is number 0. |
|
|
|
`mpz_size' can be used to find how many limbs make up OP. |
|
`mpz_getlimbn' returns zero if N is outside the range 0 to |
|
`mpz_size(OP)-1'. |
|
|
|
|
File: gmp.info, Node: Float Arithmetic, Next: Float Comparison, Prev: Converting Floats, Up: Floating-point Functions |
File: gmp.info, Node: Integer Arithmetic, Next: Integer Division, Prev: Converting Integers, Up: Integer Functions |
|
|
Arithmetic Functions |
Arithmetic Functions |
==================== |
==================== |
|
|
- Function: void mpf_add (mpf_t ROP, mpf_t OP1, mpf_t OP2) |
- Function: void mpz_add (mpz_t ROP, mpz_t OP1, mpz_t OP2) |
- Function: void mpf_add_ui (mpf_t ROP, mpf_t OP1, unsigned long int |
- Function: void mpz_add_ui (mpz_t ROP, mpz_t OP1, unsigned long int |
OP2) |
OP2) |
Set ROP to OP1 + OP2. |
Set ROP to OP1 + OP2. |
|
|
- Function: void mpf_sub (mpf_t ROP, mpf_t OP1, mpf_t OP2) |
- Function: void mpz_sub (mpz_t ROP, mpz_t OP1, mpz_t OP2) |
- Function: void mpf_ui_sub (mpf_t ROP, unsigned long int OP1, mpf_t |
- Function: void mpz_sub_ui (mpz_t ROP, mpz_t OP1, unsigned long int |
OP2) |
OP2) |
- Function: void mpf_sub_ui (mpf_t ROP, mpf_t OP1, unsigned long int |
- Function: void mpz_ui_sub (mpz_t ROP, unsigned long int OP1, mpz_t |
OP2) |
OP2) |
Set ROP to OP1 - OP2. |
Set ROP to OP1 - OP2. |
|
|
- Function: void mpf_mul (mpf_t ROP, mpf_t OP1, mpf_t OP2) |
- Function: void mpz_mul (mpz_t ROP, mpz_t OP1, mpz_t OP2) |
- Function: void mpf_mul_ui (mpf_t ROP, mpf_t OP1, unsigned long int |
- Function: void mpz_mul_si (mpz_t ROP, mpz_t OP1, long int OP2) |
|
- Function: void mpz_mul_ui (mpz_t ROP, mpz_t OP1, unsigned long int |
OP2) |
OP2) |
Set ROP to OP1 times OP2. |
Set ROP to OP1 times OP2. |
|
|
Division is undefined if the divisor is zero, and passing a zero |
- Function: void mpz_addmul (mpz_t ROP, mpz_t OP1, mpz_t OP2) |
divisor to the divide functions will make these functions intentionally |
- Function: void mpz_addmul_ui (mpz_t ROP, mpz_t OP1, unsigned long |
divide by zero. This lets the user handle arithmetic exceptions in |
int OP2) |
these functions in the same manner as other arithmetic exceptions. |
Set ROP to ROP + OP1 times OP2. |
|
|
- Function: void mpf_div (mpf_t ROP, mpf_t OP1, mpf_t OP2) |
- Function: void mpz_submul (mpz_t ROP, mpz_t OP1, mpz_t OP2) |
- Function: void mpf_ui_div (mpf_t ROP, unsigned long int OP1, mpf_t |
- Function: void mpz_submul_ui (mpz_t ROP, mpz_t OP1, unsigned long |
OP2) |
int OP2) |
- Function: void mpf_div_ui (mpf_t ROP, mpf_t OP1, unsigned long int |
Set ROP to ROP - OP1 times OP2. |
OP2) |
|
Set ROP to OP1/OP2. |
|
|
|
- Function: void mpf_sqrt (mpf_t ROP, mpf_t OP) |
- Function: void mpz_mul_2exp (mpz_t ROP, mpz_t OP1, unsigned long int |
- Function: void mpf_sqrt_ui (mpf_t ROP, unsigned long int OP) |
|
Set ROP to the square root of OP. |
|
|
|
- Function: void mpf_pow_ui (mpf_t ROP, mpf_t OP1, unsigned long int |
|
OP2) |
OP2) |
Set ROP to OP1 raised to the power OP2. |
Set ROP to OP1 times 2 raised to OP2. This operation can also be |
|
defined as a left shift by OP2 bits. |
|
|
- Function: void mpf_neg (mpf_t ROP, mpf_t OP) |
- Function: void mpz_neg (mpz_t ROP, mpz_t OP) |
Set ROP to -OP. |
Set ROP to -OP. |
|
|
- Function: void mpf_abs (mpf_t ROP, mpf_t OP) |
- Function: void mpz_abs (mpz_t ROP, mpz_t OP) |
Set ROP to the absolute value of OP. |
Set ROP to the absolute value of OP. |
|
|
- Function: void mpf_mul_2exp (mpf_t ROP, mpf_t OP1, unsigned long int |
|
OP2) |
File: gmp.info, Node: Integer Division, Next: Integer Exponentiation, Prev: Integer Arithmetic, Up: Integer Functions |
Set ROP to OP1 times 2 raised to OP2. |
|
|
|
- Function: void mpf_div_2exp (mpf_t ROP, mpf_t OP1, unsigned long int |
Division Functions |
OP2) |
================== |
Set ROP to OP1 divided by 2 raised to OP2. |
|
|
|
|
Division is undefined if the divisor is zero. Passing a zero |
File: gmp.info, Node: Float Comparison, Next: I/O of Floats, Prev: Float Arithmetic, Up: Floating-point Functions |
divisor to the division or modulo functions (including the modular |
|
powering functions `mpz_powm' and `mpz_powm_ui'), will cause an |
|
intentional division by zero. This lets a program handle arithmetic |
|
exceptions in these functions the same way as for normal C `int' |
|
arithmetic. |
|
|
Comparison Functions |
- Function: void mpz_cdiv_q (mpz_t Q, mpz_t N, mpz_t D) |
==================== |
- Function: void mpz_cdiv_r (mpz_t R, mpz_t N, mpz_t D) |
|
- Function: void mpz_cdiv_qr (mpz_t Q, mpz_t R, mpz_t N, mpz_t D) |
|
- Function: unsigned long int mpz_cdiv_q_ui (mpz_t Q, mpz_t N, |
|
unsigned long int D) |
|
- Function: unsigned long int mpz_cdiv_r_ui (mpz_t R, mpz_t N, |
|
unsigned long int D) |
|
- Function: unsigned long int mpz_cdiv_qr_ui (mpz_t Q, mpz_t R, |
|
mpz_t N, unsigned long int D) |
|
- Function: unsigned long int mpz_cdiv_ui (mpz_t N, |
|
unsigned long int D) |
|
- Function: void mpz_cdiv_q_2exp (mpz_t Q, mpz_t N, |
|
unsigned long int B) |
|
- Function: void mpz_cdiv_r_2exp (mpz_t R, mpz_t N, |
|
unsigned long int B) |
|
|
- Function: int mpf_cmp (mpf_t OP1, mpf_t OP2) |
- Function: void mpz_fdiv_q (mpz_t Q, mpz_t N, mpz_t D) |
- Function: int mpf_cmp_ui (mpf_t OP1, unsigned long int OP2) |
- Function: void mpz_fdiv_r (mpz_t R, mpz_t N, mpz_t D) |
- Function: int mpf_cmp_si (mpf_t OP1, signed long int OP2) |
- Function: void mpz_fdiv_qr (mpz_t Q, mpz_t R, mpz_t N, mpz_t D) |
Compare OP1 and OP2. Return a positive value if OP1 > OP2, zero |
- Function: unsigned long int mpz_fdiv_q_ui (mpz_t Q, mpz_t N, |
if OP1 = OP2, and a negative value if OP1 < OP2. |
unsigned long int D) |
|
- Function: unsigned long int mpz_fdiv_r_ui (mpz_t R, mpz_t N, |
|
unsigned long int D) |
|
- Function: unsigned long int mpz_fdiv_qr_ui (mpz_t Q, mpz_t R, |
|
mpz_t N, unsigned long int D) |
|
- Function: unsigned long int mpz_fdiv_ui (mpz_t N, |
|
unsigned long int D) |
|
- Function: void mpz_fdiv_q_2exp (mpz_t Q, mpz_t N, |
|
unsigned long int B) |
|
- Function: void mpz_fdiv_r_2exp (mpz_t R, mpz_t N, |
|
unsigned long int B) |
|
|
- Function: int mpf_eq (mpf_t OP1, mpf_t OP2, unsigned long int op3) |
- Function: void mpz_tdiv_q (mpz_t Q, mpz_t N, mpz_t D) |
Return non-zero if the first OP3 bits of OP1 and OP2 are equal, |
- Function: void mpz_tdiv_r (mpz_t R, mpz_t N, mpz_t D) |
zero otherwise. I.e., test of OP1 and OP2 are approximately equal. |
- Function: void mpz_tdiv_qr (mpz_t Q, mpz_t R, mpz_t N, mpz_t D) |
|
- Function: unsigned long int mpz_tdiv_q_ui (mpz_t Q, mpz_t N, |
|
unsigned long int D) |
|
- Function: unsigned long int mpz_tdiv_r_ui (mpz_t R, mpz_t N, |
|
unsigned long int D) |
|
- Function: unsigned long int mpz_tdiv_qr_ui (mpz_t Q, mpz_t R, |
|
mpz_t N, unsigned long int D) |
|
- Function: unsigned long int mpz_tdiv_ui (mpz_t N, |
|
unsigned long int D) |
|
- Function: void mpz_tdiv_q_2exp (mpz_t Q, mpz_t N, |
|
unsigned long int B) |
|
- Function: void mpz_tdiv_r_2exp (mpz_t R, mpz_t N, |
|
unsigned long int B) |
|
|
- Function: void mpf_reldiff (mpf_t ROP, mpf_t OP1, mpf_t OP2) |
Divide N by D, forming a quotient Q and/or remainder R. For the |
Compute the relative difference between OP1 and OP2 and store the |
`2exp' functions, D=2^B. The rounding is in three styles, each |
result in ROP. |
suiting different applications. |
|
|
- Macro: int mpf_sgn (mpf_t OP) |
* `cdiv' rounds Q up towards +infinity, and R will have the |
Return +1 if OP > 0, 0 if OP = 0, and -1 if OP < 0. |
opposite sign to D. The `c' stands for "ceil". |
|
|
This function is actually implemented as a macro. It evaluates its |
* `fdiv' rounds Q down towards -infinity, and R will have the |
arguments multiple times. |
same sign as D. The `f' stands for "floor". |
|
|
|
* `tdiv' rounds Q towards zero, and R will have the same sign |
File: gmp.info, Node: I/O of Floats, Next: Miscellaneous Float Functions, Prev: Float Comparison, Up: Floating-point Functions |
as N. The `t' stands for "truncate". |
|
|
Input and Output Functions |
In all cases Q and R will satisfy N=Q*D+R, and R will satisfy |
========================== |
0<=abs(R)<abs(D). |
|
|
Functions that perform input from a stdio stream, and functions that |
The `q' functions calculate only the quotient, the `r' functions |
output to a stdio stream. Passing a `NULL' pointer for a STREAM |
only the remainder, and the `qr' functions calculate both. Note |
argument to any of these functions will make them read from `stdin' and |
that for `qr' the same variable cannot be passed for both Q and R, |
write to `stdout', respectively. |
or results will be unpredictable. |
|
|
When using any of these functions, it is a good idea to include |
For the `ui' variants the return value is the remainder, and in |
`stdio.h' before `gmp.h', since that will allow `gmp.h' to define |
fact returning the remainder is all the `div_ui' functions do. For |
prototypes for these functions. |
`tdiv' and `cdiv' the remainder can be negative, so for those the |
|
return value is the absolute value of the remainder. |
|
|
- Function: size_t mpf_out_str (FILE *STREAM, int BASE, size_t |
The `2exp' functions are right shifts and bit masks, but of course |
N_DIGITS, mpf_t OP) |
rounding the same as the other functions. For positive N both |
Output OP on stdio stream STREAM, as a string of digits in base |
`mpz_fdiv_q_2exp' and `mpz_tdiv_q_2exp' are simple bitwise right |
BASE. The base may vary from 2 to 36. Print at most N_DIGITS |
shifts. For negative N, `mpz_fdiv_q_2exp' is effectively an |
significant digits, or if N_DIGITS is 0, the maximum number of |
arithmetic right shift treating N as twos complement the same as |
digits accurately representable by OP. |
the bitwise logical functions do, whereas `mpz_tdiv_q_2exp' |
|
effectively treats N as sign and magnitude. |
|
|
In addition to the significant digits, a leading `0.' and a |
- Function: void mpz_mod (mpz_t R, mpz_t N, mpz_t D) |
trailing exponent, in the form `eNNN', are printed. If BASE is |
- Function: unsigned long int mpz_mod_ui (mpz_t R, mpz_t N, |
greater than 10, `@' will be used instead of `e' as exponent |
unsigned long int D) |
delimiter. |
Set R to N `mod' D. The sign of the divisor is ignored; the |
|
result is always non-negative. |
|
|
Return the number of bytes written, or if an error occurred, |
`mpz_mod_ui' is identical to `mpz_fdiv_r_ui' above, returning the |
return 0. |
remainder as well as setting R. See `mpz_fdiv_ui' above if only |
|
the return value is wanted. |
|
|
- Function: size_t mpf_inp_str (mpf_t ROP, FILE *STREAM, int BASE) |
- Function: void mpz_divexact (mpz_t Q, mpz_t N, mpz_t D) |
Input a string in base BASE from stdio stream STREAM, and put the |
- Function: void mpz_divexact_ui (mpz_t Q, mpz_t N, unsigned long D) |
read float in ROP. The string is of the form `M@N' or, if the |
Set Q to N/D. These functions produce correct results only when |
base is 10 or less, alternatively `MeN'. `M' is the mantissa and |
it is known in advance that D divides N. |
`N' is the exponent. The mantissa is always in the specified |
|
base. The exponent is either in the specified base or, if BASE is |
|
negative, in decimal. |
|
|
|
The argument BASE may be in the ranges 2 to 36, or -36 to -2. |
These routines are much faster than the other division functions, |
Negative values are used to specify that the exponent is in |
and are the best choice when exact division is known to occur, for |
decimal. |
example reducing a rational to lowest terms. |
|
|
Unlike the corresponding `mpz' function, the base will not be |
- Function: int mpz_divisible_p (mpz_t N, mpz_t D) |
determined from the leading characters of the string if BASE is 0. |
- Function: int mpz_divisible_ui_p (mpz_t N, unsigned long int D) |
This is so that numbers like `0.23' are not interpreted as octal. |
- Function: int mpz_divisible_2exp_p (mpz_t N, unsigned long int B) |
|
Return non-zero if N is exactly divisible by D, or in the case of |
|
`mpz_divisible_2exp_p' by 2^B. |
|
|
Return the number of bytes read, or if an error occurred, return 0. |
- Function: int mpz_congruent_p (mpz_t N, mpz_t C, mpz_t D) |
|
- Function: int mpz_congruent_ui_p (mpz_t N, unsigned long int C, |
|
unsigned long int D) |
|
- Function: int mpz_congruent_2exp_p (mpz_t N, mpz_t C, unsigned long |
|
int B) |
|
Return non-zero if N is congruent to C modulo D, or in the case of |
|
`mpz_congruent_2exp_p' modulo 2^B. |
|
|
|
|
File: gmp.info, Node: Miscellaneous Float Functions, Prev: I/O of Floats, Up: Floating-point Functions |
File: gmp.info, Node: Integer Exponentiation, Next: Integer Roots, Prev: Integer Division, Up: Integer Functions |
|
|
Miscellaneous Functions |
Exponentiation Functions |
======================= |
======================== |
|
|
- Function: void mpf_ceil (mpf_t ROP, mpf_t OP) |
- Function: void mpz_powm (mpz_t ROP, mpz_t BASE, mpz_t EXP, mpz_t MOD) |
- Function: void mpf_floor (mpf_t ROP, mpf_t OP) |
- Function: void mpz_powm_ui (mpz_t ROP, mpz_t BASE, unsigned long int |
- Function: void mpf_trunc (mpf_t ROP, mpf_t OP) |
EXP, mpz_t MOD) |
Set ROP to OP rounded to an integer. `mpf_ceil' rounds to the |
Set ROP to (BASE raised to EXP) modulo MOD. |
next higher integer, `mpf_floor' to the next lower, and |
|
`mpf_trunc' to the integer towards zero. |
|
|
|
- Function: void mpf_urandomb (mpf_t ROP, gmp_randstate_t STATE, |
Negative EXP is supported if an inverse BASE^-1 mod MOD exists |
unsigned long int NBITS) |
(see `mpz_invert' in *Note Number Theoretic Functions::). If an |
Generate a uniformly distributed random float in ROP, such that 0 |
inverse doesn't exist then a divide by zero is raised. |
<= ROP < 1, with NBITS significant bits in the mantissa. |
|
|
|
The variable STATE must be initialized by calling one of the |
- Function: void mpz_pow_ui (mpz_t ROP, mpz_t BASE, unsigned long int |
`gmp_randinit' functions (*Note Random State Initialization::) |
EXP) |
before invoking this function. |
- Function: void mpz_ui_pow_ui (mpz_t ROP, unsigned long int BASE, |
|
unsigned long int EXP) |
|
Set ROP to BASE raised to EXP. The case 0^0 yields 1. |
|
|
- Function: void mpf_random2 (mpf_t ROP, mp_size_t MAX_SIZE, mp_exp_t |
|
MAX_EXP) |
File: gmp.info, Node: Integer Roots, Next: Number Theoretic Functions, Prev: Integer Exponentiation, Up: Integer Functions |
Generate a random float of at most MAX_SIZE limbs, with long |
|
strings of zeros and ones in the binary representation. The |
Root Extraction Functions |
exponent of the number is in the interval -EXP to EXP. This |
========================= |
function is useful for testing functions and algorithms, since |
|
this kind of random numbers have proven to be more likely to |
- Function: int mpz_root (mpz_t ROP, mpz_t OP, unsigned long int N) |
trigger corner-case bugs. Negative random numbers are generated |
Set ROP to the truncated integer part of the Nth root of OP. |
when MAX_SIZE is negative. |
Return non-zero if the computation was exact, i.e., if OP is ROP |
|
to the Nth power. |
|
|
|
- Function: void mpz_sqrt (mpz_t ROP, mpz_t OP) |
|
Set ROP to the truncated integer part of the square root of OP. |
|
|
|
- Function: void mpz_sqrtrem (mpz_t ROP1, mpz_t ROP2, mpz_t OP) |
|
Set ROP1 to the truncated integer part of the square root of OP, |
|
like `mpz_sqrt'. Set ROP2 to the remainder OP-ROP1*ROP1, which |
|
will be zero if OP is a perfect square. |
|
|
|
If ROP1 and ROP2 are the same variable, the results are undefined. |
|
|
|
- Function: int mpz_perfect_power_p (mpz_t OP) |
|
Return non-zero if OP is a perfect power, i.e., if there exist |
|
integers A and B, with B>1, such that OP equals A raised to the |
|
power B. |
|
|
|
Under this definition both 0 and 1 are considered to be perfect |
|
powers. Negative values of OP are accepted, but of course can |
|
only be odd perfect powers. |
|
|
|
- Function: int mpz_perfect_square_p (mpz_t OP) |
|
Return non-zero if OP is a perfect square, i.e., if the square |
|
root of OP is an integer. Under this definition both 0 and 1 are |
|
considered to be perfect squares. |
|
|