version 1.1.1.3, 2000/12/01 05:44:46 |
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: Number Theoretic Functions, Next: Integer Comparisons, Prev: Integer Roots, Up: Integer Functions |
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Copyright (C) 1991, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000 |
Number Theoretic Functions |
Free Software Foundation, Inc. |
========================== |
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Permission is granted to make and distribute verbatim copies of this |
- Function: int mpz_probab_prime_p (mpz_t N, int REPS) |
manual provided the copyright notice and this permission notice are |
Determine whether N is prime. Return 2 if N is definitely prime, |
preserved on all copies. |
return 1 if N is probably prime (without being certain), or return |
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0 if N is definitely composite. |
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Permission is granted to copy and distribute modified versions of |
This function does some trial divisions, then some Miller-Rabin |
this manual under the conditions for verbatim copying, provided that |
probabilistic primality tests. REPS controls how many such tests |
the entire resulting derived work is distributed under the terms of a |
are done, 5 to 10 is a reasonable number, more will reduce the |
permission notice identical to this one. |
chances of a composite being returned as "probably prime". |
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Permission is granted to copy and distribute translations of this |
Miller-Rabin and similar tests can be more properly called |
manual into another language, under the above conditions for modified |
compositeness tests. Numbers which fail are known to be composite |
versions, except that this permission notice may be stated in a |
but those which pass might be prime or might be composite. Only a |
translation approved by the Foundation. |
few composites pass, hence those which pass are considered |
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probably prime. |
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- Function: void mpz_nextprime (mpz_t ROP, mpz_t OP) |
File: gmp.info, Node: Low-level Functions, Next: Random Number Functions, Prev: Floating-point Functions, Up: Top |
Set ROP to the next prime greater than OP. |
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Low-level Functions |
This function uses a probabilistic algorithm to identify primes. |
******************* |
For practical purposes it's adequate, the chance of a composite |
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passing will be extremely small. |
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This chapter describes low-level GMP functions, used to implement |
- Function: void mpz_gcd (mpz_t ROP, mpz_t OP1, mpz_t OP2) |
the high-level GMP functions, but also intended for time-critical user |
Set ROP to the greatest common divisor of OP1 and OP2. The result |
code. |
is always positive even if one or both input operands are negative. |
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These functions start with the prefix `mpn_'. |
- Function: unsigned long int mpz_gcd_ui (mpz_t ROP, mpz_t OP1, |
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unsigned long int OP2) |
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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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The `mpn' functions are designed to be as fast as possible, *not* to |
If the result is small enough to fit in an `unsigned long int', it |
provide a coherent calling interface. The different functions have |
is returned. If the result does not fit, 0 is returned, and the |
somewhat similar interfaces, but there are variations that make them |
result is equal to the argument OP1. Note that the result will |
hard to use. These functions do as little as possible apart from the |
always fit if OP2 is non-zero. |
real multiple precision computation, so that no time is spent on things |
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that not all callers need. |
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A source operand is specified by a pointer to the least significant |
- Function: void mpz_gcdext (mpz_t G, mpz_t S, mpz_t T, mpz_t A, mpz_t |
limb and a limb count. A destination operand is specified by just a |
B) |
pointer. It is the responsibility of the caller to ensure that the |
Set G to the greatest common divisor of A and B, and in addition |
destination has enough space for storing the result. |
set S and T to coefficients satisfying A*S + B*T = G. G is always |
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positive, even if one or both of A and B are negative. |
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With this way of specifying operands, it is possible to perform |
If T is `NULL' then that value is not computed. |
computations on subranges of an argument, and store the result into a |
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subrange of a destination. |
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A common requirement for all functions is that each source area |
- Function: void mpz_lcm (mpz_t ROP, mpz_t OP1, mpz_t OP2) |
needs at least one limb. No size argument may be zero. Unless |
- Function: void mpz_lcm_ui (mpz_t ROP, mpz_t OP1, unsigned long OP2) |
otherwise stated, in-place operations are allowed where source and |
Set ROP to the least common multiple of OP1 and OP2. ROP is |
destination are the same, but not where they only partly overlap. |
always positive, irrespective of the signs of OP1 and OP2. ROP |
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will be zero if either OP1 or OP2 is zero. |
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The `mpn' functions are the base for the implementation of the |
- Function: int mpz_invert (mpz_t ROP, mpz_t OP1, mpz_t OP2) |
`mpz_', `mpf_', and `mpq_' functions. |
Compute the inverse of OP1 modulo OP2 and put the result in ROP. |
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If the inverse exists, the return value is non-zero and ROP will |
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satisfy 0 <= ROP < OP2. If an inverse doesn't exist the return |
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value is zero and ROP is undefined. |
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This example adds the number beginning at S1P and the number |
- Function: int mpz_jacobi (mpz_t A, mpz_t B) |
beginning at S2P and writes the sum at DESTP. All areas have SIZE |
Calculate the Jacobi symbol (A/B). This is defined only for B odd. |
limbs. |
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cy = mpn_add_n (destp, s1p, s2p, size) |
- Function: int mpz_legendre (mpz_t A, mpz_t P) |
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Calculate the Legendre symbol (A/P). This is defined only for P |
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an odd positive prime, and for such P it's identical to the Jacobi |
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symbol. |
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In the notation used here, a source operand is identified by the |
- Function: int mpz_kronecker (mpz_t A, mpz_t B) |
pointer to the least significant limb, and the limb count in braces. |
- Function: int mpz_kronecker_si (mpz_t A, long B) |
For example, {s1p, s1size}. |
- Function: int mpz_kronecker_ui (mpz_t A, unsigned long B) |
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- Function: int mpz_si_kronecker (long A, mpz_t B) |
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- Function: int mpz_ui_kronecker (unsigned long A, mpz_t B) |
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Calculate the Jacobi symbol (A/B) with the Kronecker extension |
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(a/2)=(2/a) when a odd, or (a/2)=0 when a even. |
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- Function: mp_limb_t mpn_add_n (mp_limb_t *RP, const mp_limb_t *S1P, |
When B is odd the Jacobi symbol and Kronecker symbol are |
const mp_limb_t *S2P, mp_size_t SIZE) |
identical, so `mpz_kronecker_ui' etc can be used for mixed |
Add {S1P, SIZE} and {S2P, SIZE}, and write the SIZE least |
precision Jacobi symbols too. |
significant limbs of the result to RP. Return carry, either 0 or |
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1. |
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This is the lowest-level function for addition. It is the |
For more information see Henri Cohen section 1.4.2 (*note |
preferred function for addition, since it is written in assembly |
References::), or any number theory textbook. See also the |
for most targets. For addition of a variable to itself (i.e., S1P |
example program `demos/qcn.c' which uses `mpz_kronecker_ui'. |
equals S2P, use `mpn_lshift' with a count of 1 for optimal speed. |
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- Function: mp_limb_t mpn_add_1 (mp_limb_t *RP, const mp_limb_t *S1P, |
- Function: unsigned long int mpz_remove (mpz_t ROP, mpz_t OP, mpz_t F) |
mp_size_t SIZE, mp_limb_t S2LIMB) |
Remove all occurrences of the factor F from OP and store the |
Add {S1P, SIZE} and S2LIMB, and write the SIZE least significant |
result in ROP. The return value is how many such occurrences were |
limbs of the result to RP. Return carry, either 0 or 1. |
removed. |
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- Function: mp_limb_t mpn_add (mp_limb_t *RP, const mp_limb_t *S1P, |
- Function: void mpz_fac_ui (mpz_t ROP, unsigned long int OP) |
mp_size_t S1SIZE, const mp_limb_t *S2P, mp_size_t S2SIZE) |
Set ROP to OP!, the factorial of OP. |
Add {S1P, S1SIZE} and {S2P, S2SIZE}, and write the S1SIZE least |
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significant limbs of the result to RP. Return carry, either 0 or |
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1. |
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This function requires that S1SIZE is greater than or equal to |
- Function: void mpz_bin_ui (mpz_t ROP, mpz_t N, unsigned long int K) |
S2SIZE. |
- Function: void mpz_bin_uiui (mpz_t ROP, unsigned long int N, |
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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: mp_limb_t mpn_sub_n (mp_limb_t *RP, const mp_limb_t *S1P, |
- Function: void mpz_fib_ui (mpz_t FN, unsigned long int N) |
const mp_limb_t *S2P, mp_size_t SIZE) |
- Function: void mpz_fib2_ui (mpz_t FN, mpz_t FNSUB1, unsigned long |
Subtract {S2P, S2SIZE} from {S1P, SIZE}, and write the SIZE least |
int N) |
significant limbs of the result to RP. Return borrow, either 0 or |
`mpz_fib_ui' sets FN to to F[n], the N'th Fibonacci number. |
1. |
`mpz_fib2_ui' sets FN to F[n], and FNSUB1 to F[n-1]. |
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This is the lowest-level function for subtraction. It is the |
These functions are designed for calculating isolated Fibonacci |
preferred function for subtraction, since it is written in |
numbers. When a sequence of values is wanted it's best to start |
assembly for most targets. |
with `mpz_fib2_ui' and iterate the defining F[n+1]=F[n]+F[n-1] or |
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similar. |
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- Function: mp_limb_t mpn_sub_1 (mp_limb_t *RP, const mp_limb_t *S1P, |
- Function: void mpz_lucnum_ui (mpz_t LN, unsigned long int N) |
mp_size_t SIZE, mp_limb_t S2LIMB) |
- Function: void mpz_lucnum2_ui (mpz_t LN, mpz_t LNSUB1, unsigned long |
Subtract S2LIMB from {S1P, SIZE}, and write the SIZE least |
int N) |
significant limbs of the result to RP. Return borrow, either 0 or |
`mpz_lucnum_ui' sets LN to to L[n], the N'th Lucas number. |
1. |
`mpz_lucnum2_ui' sets LN to L[n], and LNSUB1 to L[n-1]. |
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- Function: mp_limb_t mpn_sub (mp_limb_t *RP, const mp_limb_t *S1P, |
These functions are designed for calculating isolated Lucas |
mp_size_t S1SIZE, const mp_limb_t *S2P, mp_size_t S2SIZE) |
numbers. When a sequence of values is wanted it's best to start |
Subtract {S2P, S2SIZE} from {S1P, S1SIZE}, and write the S1SIZE |
with `mpz_lucnum2_ui' and iterate the defining L[n+1]=L[n]+L[n-1] |
least significant limbs of the result to RP. Return borrow, |
or similar. |
either 0 or 1. |
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This function requires that S1SIZE is greater than or equal to |
The Fibonacci numbers and Lucas numbers are related sequences, so |
S2SIZE. |
it's never necessary to call both `mpz_fib2_ui' and |
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`mpz_lucnum2_ui'. The formulas for going from Fibonacci to Lucas |
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can be found in *Note Lucas Numbers Algorithm::, the reverse is |
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straightforward too. |
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- Function: void mpn_mul_n (mp_limb_t *RP, const mp_limb_t *S1P, const |
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mp_limb_t *S2P, mp_size_t SIZE) |
File: gmp.info, Node: Integer Comparisons, Next: Integer Logic and Bit Fiddling, Prev: Number Theoretic Functions, Up: Integer Functions |
Multiply {S1P, SIZE} and {S2P, SIZE}, and write the *entire* |
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result to RP. |
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The destination has to have space for 2*SIZE limbs, even if the |
Comparison Functions |
significant result might be one limb smaller. |
==================== |
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- Function: mp_limb_t mpn_mul_1 (mp_limb_t *RP, const mp_limb_t *S1P, |
- Function: int mpz_cmp (mpz_t OP1, mpz_t OP2) |
mp_size_t SIZE, mp_limb_t S2LIMB) |
- Function: int mpz_cmp_d (mpz_t OP1, double OP2) |
Multiply {S1P, SIZE} and S2LIMB, and write the SIZE least |
- Macro: int mpz_cmp_si (mpz_t OP1, signed long int OP2) |
significant limbs of the product to RP. Return the most |
- Macro: int mpz_cmp_ui (mpz_t OP1, unsigned long int OP2) |
significant limb of the product. |
Compare OP1 and OP2. Return a positive value if OP1 > OP2, zero |
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if OP1 = OP2, or a negative value if OP1 < OP2. |
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This is a low-level function that is a building block for general |
Note that `mpz_cmp_ui' and `mpz_cmp_si' are macros and will |
multiplication as well as other operations in GMP. It is written |
evaluate their arguments more than once. |
in assembly for most targets. |
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Don't call this function if S2LIMB is a power of 2; use |
- Function: int mpz_cmpabs (mpz_t OP1, mpz_t OP2) |
`mpn_lshift' with a count equal to the logarithm of S2LIMB |
- Function: int mpz_cmpabs_d (mpz_t OP1, double OP2) |
instead, for optimal speed. |
- Function: int mpz_cmpabs_ui (mpz_t OP1, unsigned long int OP2) |
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Compare the absolute values of OP1 and OP2. Return a positive |
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value if abs(OP1) > abs(OP2), zero if abs(OP1) = abs(OP2), or a |
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negative value if abs(OP1) < abs(OP2). |
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- Function: mp_limb_t mpn_addmul_1 (mp_limb_t *RP, const mp_limb_t |
Note that `mpz_cmpabs_si' is a macro and will evaluate its |
*S1P, mp_size_t SIZE, mp_limb_t S2LIMB) |
arguments more than once. |
Multiply {S1P, SIZE} and S2LIMB, and add the SIZE least |
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significant limbs of the product to {RP, SIZE} and write the |
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result to RP. Return the most significant limb of the product, |
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plus carry-out from the addition. |
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This is a low-level function that is a building block for general |
- Macro: int mpz_sgn (mpz_t OP) |
multiplication as well as other operations in GMP. It is written |
Return +1 if OP > 0, 0 if OP = 0, and -1 if OP < 0. |
in assembly for most targets. |
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- Function: mp_limb_t mpn_submul_1 (mp_limb_t *RP, const mp_limb_t |
This function is actually implemented as a macro. It evaluates |
*S1P, mp_size_t SIZE, mp_limb_t S2LIMB) |
its argument multiple times. |
Multiply {S1P, SIZE} and S2LIMB, and subtract the SIZE least |
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significant limbs of the product from {RP, SIZE} and write the |
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result to RP. Return the most significant limb of the product, |
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minus borrow-out from the subtraction. |
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This is a low-level function that is a building block for general |
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multiplication and division as well as other operations in GMP. |
File: gmp.info, Node: Integer Logic and Bit Fiddling, Next: I/O of Integers, Prev: Integer Comparisons, Up: Integer Functions |
It is written in assembly for most targets. |
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- Function: mp_limb_t mpn_mul (mp_limb_t *RP, const mp_limb_t *S1P, |
Logical and Bit Manipulation Functions |
mp_size_t S1SIZE, const mp_limb_t *S2P, mp_size_t S2SIZE) |
====================================== |
Multiply {S1P, S1SIZE} and {S2P, S2SIZE}, and write the result to |
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RP. Return the most significant limb of the result. |
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The destination has to have space for S1SIZE + S2SIZE limbs, even |
These functions behave as if twos complement arithmetic were used |
if the result might be one limb smaller. |
(although sign-magnitude is the actual implementation). The least |
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significant bit is number 0. |
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This function requires that S1SIZE is greater than or equal to |
- Function: void mpz_and (mpz_t ROP, mpz_t OP1, mpz_t OP2) |
S2SIZE. The destination must be distinct from either input |
Set ROP to OP1 logical-and OP2. |
operands. |
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- Function: void mpn_tdiv_qr (mp_limb_t *QP, mp_limb_t *RP, mp_size_t |
- Function: void mpz_ior (mpz_t ROP, mpz_t OP1, mpz_t OP2) |
QXN, const mp_limb_t *NP, mp_size_t NN, const mp_limb_t *DP, |
Set ROP to OP1 inclusive-or OP2. |
mp_size_t DN) |
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Divide {NP, NN} by {DP, DN}. Write the quotient at QP and the |
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remainder at RP. |
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The quotient written at QP will be NN - DN + 1 limbs. The |
- Function: void mpz_xor (mpz_t ROP, mpz_t OP1, mpz_t OP2) |
remainder written at RP will be DN limbs. |
Set ROP to OP1 exclusive-or OP2. |
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It is required that NN is greater than or equal to DN. The QXN |
- Function: void mpz_com (mpz_t ROP, mpz_t OP) |
operand must be zero. |
Set ROP to the one's complement of OP. |
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The quotient is rounded towards 0. |
- Function: unsigned long int mpz_popcount (mpz_t OP) |
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If OP>=0, return the population count of OP, which is the number |
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of 1 bits in the binary representation. If OP<0, the number of 1s |
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is infinite, and the return value is MAX_ULONG, the largest |
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possible `unsigned long'. |
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No overlap between arguments is permitted. |
- Function: unsigned long int mpz_hamdist (mpz_t OP1, mpz_t OP2) |
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If OP1 and OP2 are both >=0 or both <0, return the hamming |
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distance between the two operands, which is the number of bit |
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positions where OP1 and OP2 have different bit values. If one |
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operand is >=0 and the other <0 then the number of bits different |
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is infinite, and the return value is MAX_ULONG, the largest |
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possible `unsigned long'. |
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- Function: mp_limb_t mpn_divrem (mp_limb_t *R1P, mp_size_t XSIZE, |
- Function: unsigned long int mpz_scan0 (mpz_t OP, unsigned long int |
mp_limb_t *RS2P, mp_size_t RS2SIZE, const mp_limb_t *S3P, |
STARTING_BIT) |
mp_size_t S3SIZE) |
- Function: unsigned long int mpz_scan1 (mpz_t OP, unsigned long int |
[This function is obsolete. Please call `mpn_tdiv_qr' instead for |
STARTING_BIT) |
best performance.] |
Scan OP, starting from bit STARTING_BIT, towards more significant |
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bits, until the first 0 or 1 bit (respectively) is found. Return |
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the index of the found bit. |
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Divide {RS2P, RS2SIZE} by {S3P, S3SIZE}, and write the quotient at |
If the bit at STARTING_BIT is already what's sought, then |
R1P, with the exception of the most significant limb, which is |
STARTING_BIT is returned. |
returned. The remainder replaces the dividend at RS2P; it will be |
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S3SIZE limbs long (i.e., as many limbs as the divisor). |
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In addition to an integer quotient, XSIZE fraction limbs are |
If there's no bit found, then MAX_ULONG is returned. This will |
developed, and stored after the integral limbs. For most usages, |
happen in `mpz_scan0' past the end of a positive number, or |
XSIZE will be zero. |
`mpz_scan1' past the end of a negative. |
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It is required that RS2SIZE is greater than or equal to S3SIZE. |
- Function: void mpz_setbit (mpz_t ROP, unsigned long int BIT_INDEX) |
It is required that the most significant bit of the divisor is set. |
Set bit BIT_INDEX in ROP. |
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If the quotient is not needed, pass RS2P + S3SIZE as R1P. Aside |
- Function: void mpz_clrbit (mpz_t ROP, unsigned long int BIT_INDEX) |
from that special case, no overlap between arguments is permitted. |
Clear bit BIT_INDEX in ROP. |
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Return the most significant limb of the quotient, either 0 or 1. |
- Function: int mpz_tstbit (mpz_t OP, unsigned long int BIT_INDEX) |
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Test bit BIT_INDEX in OP and return 0 or 1 accordingly. |
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The area at R1P needs to be RS2SIZE - S3SIZE + XSIZE limbs large. |
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File: gmp.info, Node: I/O of Integers, Next: Integer Random Numbers, Prev: Integer Logic and Bit Fiddling, Up: Integer Functions |
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- Function: mp_limb_t mpn_divrem_1 (mp_limb_t *R1P, mp_size_t XSIZE, |
Input and Output Functions |
mp_limb_t *S2P, mp_size_t S2SIZE, mp_limb_t S3LIMB) |
========================== |
- Macro: mp_limb_t mpn_divmod_1 (mp_limb_t *R1P, mp_limb_t *S2P, |
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mp_size_t S2SIZE, mp_limb_t S3LIMB) |
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Divide {S2P, S2SIZE} by S3LIMB, and write the quotient at R1P. |
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Return the remainder. |
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The integer quotient is written to {R1P+XSIZE, S2SIZE} and in |
Functions that perform input from a stdio stream, and functions that |
addition XSIZE fraction limbs are developed and written to {R1P, |
output to a stdio stream. Passing a `NULL' pointer for a STREAM |
XSIZE}. Either or both S2SIZE and XSIZE can be zero. For most |
argument to any of these functions will make them read from `stdin' and |
usages, XSIZE will be zero. |
write to `stdout', respectively. |
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`mpn_divmod_1' exists for upward source compatibility and is |
When using any of these functions, it is a good idea to include |
simply a macro calling `mpn_divrem_1' with an XSIZE of 0. |
`stdio.h' before `gmp.h', since that will allow `gmp.h' to define |
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prototypes for these functions. |
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The areas at R1P and S2P have to be identical or completely |
- Function: size_t mpz_out_str (FILE *STREAM, int BASE, mpz_t OP) |
separate, not partially overlapping. |
Output OP on stdio stream STREAM, as a string of digits in base |
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BASE. The base may vary from 2 to 36. |
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- Function: mp_limb_t mpn_divmod (mp_limb_t *R1P, mp_limb_t *RS2P, |
Return the number of bytes written, or if an error occurred, |
mp_size_t RS2SIZE, const mp_limb_t *S3P, mp_size_t S3SIZE) |
return 0. |
*This interface is obsolete. It will disappear from future |
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releases. Use `mpn_divrem' in its stead.* |
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- Macro: mp_limb_t mpn_divexact_by3 (mp_limb_t *RP, mp_limb_t *SP, |
- Function: size_t mpz_inp_str (mpz_t ROP, FILE *STREAM, int BASE) |
mp_size_t SIZE) |
Input a possibly white-space preceded string in base BASE from |
- Function: mp_limb_t mpn_divexact_by3c (mp_limb_t *RP, mp_limb_t *SP, |
stdio stream STREAM, and put the read integer in ROP. The base |
mp_size_t SIZE, mp_limb_t CARRY) |
may vary from 2 to 36. If BASE is 0, the actual base is |
Divide {SP, SIZE} by 3, expecting it to divide exactly, and |
determined from the leading characters: if the first two |
writing the result to {RP, SIZE}. If 3 divides exactly, the |
characters are `0x' or `0X', hexadecimal is assumed, otherwise if |
return value is zero and the result is the quotient. If not, the |
the first character is `0', octal is assumed, otherwise decimal is |
return value is non-zero and the result won't be anything useful. |
assumed. |
|
|
`mpn_divexact_by3c' takes an initial carry parameter, which can be |
Return the number of bytes read, or if an error occurred, return 0. |
the return value from a previous call, so a large calculation can |
|
be done piece by piece. `mpn_divexact_by3' is simply a macro |
|
calling `mpn_divexact_by3c' with a 0 carry parameter. |
|
|
|
These routines use a multiply-by-inverse and will be faster than |
- Function: size_t mpz_out_raw (FILE *STREAM, mpz_t OP) |
`mpn_divrem_1' on CPUs with fast multiplication but slow division. |
Output OP on stdio stream STREAM, in raw binary format. The |
|
integer is written in a portable format, with 4 bytes of size |
|
information, and that many bytes of limbs. Both the size and the |
|
limbs are written in decreasing significance order (i.e., in |
|
big-endian). |
|
|
The source a, result q, size n, initial carry i, and return value |
The output can be read with `mpz_inp_raw'. |
c satisfy c*b^n + a-i = 3*q, where b is the size of a limb (2^32 |
|
or 2^64). c is always 0, 1 or 2, and the initial carry must also |
|
be 0, 1 or 2 (these are both borrows really). When c=0, clearly |
|
q=(a-i)/3. When c!=0, the remainder (a-i) mod 3 is given by 3-c, |
|
because b == 1 mod 3. |
|
|
|
- Function: mp_limb_t mpn_mod_1 (mp_limb_t *S1P, mp_size_t S1SIZE, |
Return the number of bytes written, or if an error occurred, |
mp_limb_t S2LIMB) |
return 0. |
Divide {S1P, S1SIZE} by S2LIMB, and return the remainder. S1SIZE |
|
can be zero. |
|
|
|
- Function: mp_limb_t mpn_preinv_mod_1 (mp_limb_t *S1P, mp_size_t |
The output of this can not be read by `mpz_inp_raw' from GMP 1, |
S1SIZE, mp_limb_t S2LIMB, mp_limb_t S3LIMB) |
because of changes necessary for compatibility between 32-bit and |
*This interface is obsolete. It will disappear from future |
64-bit machines. |
releases. Use `mpn_mod_1' in its stead.* |
|
|
|
- Function: mp_limb_t mpn_bdivmod (mp_limb_t *RP, mp_limb_t *S1P, |
- Function: size_t mpz_inp_raw (mpz_t ROP, FILE *STREAM) |
mp_size_t S1SIZE, const mp_limb_t *S2P, mp_size_t S2SIZE, |
Input from stdio stream STREAM in the format written by |
unsigned long int D) |
`mpz_out_raw', and put the result in ROP. Return the number of |
The function puts the low [D/BITS_PER_MP_LIMB] limbs of Q = {S1P, |
bytes read, or if an error occurred, return 0. |
S1SIZE}/{S2P, S2SIZE} mod 2^D at RP, and returns the high D mod |
|
BITS_PER_MP_LIMB bits of Q. |
|
|
|
{S1P, S1SIZE} - Q * {S2P, S2SIZE} mod 2^(S1SIZE*BITS_PER_MP_LIMB) |
This routine can read the output from `mpz_out_raw' also from GMP |
is placed at S1P. Since the low [D/BITS_PER_MP_LIMB] limbs of |
1, in spite of changes necessary for compatibility between 32-bit |
this difference are zero, it is possible to overwrite the low |
and 64-bit machines. |
limbs at S1P with this difference, provided RP <= S1P. |
|
|
|
This function requires that S1SIZE * BITS_PER_MP_LIMB >= D, and |
|
that {S2P, S2SIZE} is odd. |
File: gmp.info, Node: Integer Random Numbers, Next: Integer Import and Export, Prev: I/O of Integers, Up: Integer Functions |
|
|
*This interface is preliminary. It might change incompatibly in |
Random Number Functions |
future revisions.* |
======================= |
|
|
- Function: mp_limb_t mpn_lshift (mp_limb_t *RP, const mp_limb_t |
The random number functions of GMP come in two groups; older function |
*SRC_PTR, mp_size_t SRC_SIZE, unsigned long int COUNT) |
that rely on a global state, and newer functions that accept a state |
Shift {SRC_PTR, SRC_SIZE} COUNT bits to the left, and write the |
parameter that is read and modified. Please see the *Note Random |
SRC_SIZE least significant limbs of the result to RP. COUNT might |
Number Functions:: for more information on how to use and not to use |
be in the range 1 to n - 1, on an n-bit machine. The bits shifted |
random number functions. |
out to the left are returned. |
|
|
|
Overlapping of the destination space and the source space is |
- Function: void mpz_urandomb (mpz_t ROP, gmp_randstate_t STATE, |
allowed in this function, provided RP >= SRC_PTR. |
unsigned long int N) |
|
Generate a uniformly distributed random integer in the range 0 to |
|
2^N-1, inclusive. |
|
|
This function is written in assembly for most targets. |
The variable STATE must be initialized by calling one of the |
|
`gmp_randinit' functions (*Note Random State Initialization::) |
|
before invoking this function. |
|
|
- Function: mp_limp_t mpn_rshift (mp_limb_t *RP, const mp_limb_t |
- Function: void mpz_urandomm (mpz_t ROP, gmp_randstate_t STATE, mpz_t |
*SRC_PTR, mp_size_t SRC_SIZE, unsigned long int COUNT) |
N) |
Shift {SRC_PTR, SRC_SIZE} COUNT bits to the right, and write the |
Generate a uniform random integer in the range 0 to N-1, inclusive. |
SRC_SIZE most significant limbs of the result to RP. COUNT might |
|
be in the range 1 to n - 1, on an n-bit machine. The bits shifted |
|
out to the right are returned. |
|
|
|
Overlapping of the destination space and the source space is |
The variable STATE must be initialized by calling one of the |
allowed in this function, provided RP <= SRC_PTR. |
`gmp_randinit' functions (*Note Random State Initialization::) |
|
before invoking this function. |
|
|
This function is written in assembly for most targets. |
- Function: void mpz_rrandomb (mpz_t ROP, gmp_randstate_t STATE, |
|
unsigned long int N) |
|
Generate a random integer with long strings of zeros and ones in |
|
the binary representation. Useful for testing functions and |
|
algorithms, since this kind of random numbers have proven to be |
|
more likely to trigger corner-case bugs. The random number will |
|
be in the range 0 to 2^N-1, inclusive. |
|
|
- Function: int mpn_cmp (const mp_limb_t *S1P, const mp_limb_t *S2P, |
The variable STATE must be initialized by calling one of the |
mp_size_t SIZE) |
`gmp_randinit' functions (*Note Random State Initialization::) |
Compare {S1P, SIZE} and {S2P, SIZE} and return a positive value if |
before invoking this function. |
s1 > src2, 0 of they are equal, and a negative value if s1 < src2. |
|
|
|
- Function: mp_size_t mpn_gcd (mp_limb_t *RP, mp_limb_t *S1P, |
- Function: void mpz_random (mpz_t ROP, mp_size_t MAX_SIZE) |
mp_size_t S1SIZE, mp_limb_t *S2P, mp_size_t S2SIZE) |
Generate a random integer of at most MAX_SIZE limbs. The generated |
Puts at RP the greatest common divisor of {S1P, S1SIZE} and {S2P, |
random number doesn't satisfy any particular requirements of |
S2SIZE}; both source operands are destroyed by the operation. The |
randomness. Negative random numbers are generated when MAX_SIZE |
size in limbs of the greatest common divisor is returned. |
is negative. |
|
|
{S1P, S1SIZE} must have at least as many bits as {S2P, S2SIZE}, |
This function is obsolete. Use `mpz_urandomb' or `mpz_urandomm' |
and {S2P, S2SIZE} must be odd. |
instead. |
|
|
- Function: mp_limb_t mpn_gcd_1 (const mp_limb_t *S1P, mp_size_t |
- Function: void mpz_random2 (mpz_t ROP, mp_size_t MAX_SIZE) |
S1SIZE, mp_limb_t S2LIMB) |
Generate a random integer of at most MAX_SIZE limbs, with long |
Return the greatest common divisor of {S1P, S1SIZE} and S2LIMB, |
strings of zeros and ones in the binary representation. Useful |
where S2LIMB (as well as S1SIZE) must be different from 0. |
for testing functions and algorithms, since this kind of random |
|
numbers have proven to be more likely to trigger corner-case bugs. |
|
Negative random numbers are generated when MAX_SIZE is negative. |
|
|
- Function: mp_size_t mpn_gcdext (mp_limb_t *R1P, mp_limb_t *R2P, |
This function is obsolete. Use `mpz_rrandomb' instead. |
mp_size_t *R2SIZE, mp_limb_t *S1P, mp_size_t S1SIZE, |
|
mp_limb_t *S2P, mp_size_t S2SIZE) |
|
Compute the greatest common divisor of {S1P, S1SIZE} and {S2P, |
|
S2SIZE}. Store the gcd at R1P and return its size in limbs. |
|
Write the first cofactor at R2P and store its size in *R2SIZE. If |
|
the cofactor is negative, *R2SIZE is negative and R2P is the |
|
absolute value of the cofactor. |
|
|
|
{S1P, S1SIZE} must be greater than or equal to {S2P, S2SIZE}. |
|
Neither operand may equal 0. Both source operands are destroyed, |
File: gmp.info, Node: Integer Import and Export, Next: Miscellaneous Integer Functions, Prev: Integer Random Numbers, Up: Integer Functions |
plus one limb past the end of each, ie. {S1P, S1SIZE+1} and {S2P, |
|
S2SIZE+1}. |
|
|
|
- Function: mp_size_t mpn_sqrtrem (mp_limb_t *R1P, mp_limb_t *R2P, |
Integer Import and Export |
const mp_limb_t *SP, mp_size_t SIZE) |
========================= |
Compute the square root of {SP, SIZE} and put the result at R1P. |
|
Write the remainder at R2P, unless R2P is `NULL'. |
|
|
|
Return the size of the remainder, whether R2P was `NULL' or |
`mpz_t' variables can be converted to and from arbitrary words of |
non-`NULL'. Iff the operand was a perfect square, the return |
binary data with the following functions. |
value will be 0. |
|
|
|
The areas at R1P and SP have to be distinct. The areas at R2P and |
- Function: void mpz_import (mpz_t ROP, size_t COUNT, int ORDER, int |
SP have to be identical or completely separate, not partially |
SIZE, int ENDIAN, size_t NAILS, const void *OP) |
overlapping. |
Set ROP from an array of word data at OP. |
|
|
The area at R1P needs to have space for ceil(SIZE/2) limbs. The |
The parameters specify the format of the data. COUNT many words |
area at R2P needs to be SIZE limbs large. |
are read, each SIZE bytes. ORDER can be 1 for most significant |
|
word first or -1 for least significant first. Within each word |
|
ENDIAN can be 1 for most significant byte first, -1 for least |
|
significant first, or 0 for the native endianness of the host CPU. |
|
The most significant NAILS bits of each word are skipped, this |
|
can be 0 to use the full words. |
|
|
- Function: mp_size_t mpn_get_str (unsigned char *STR, int BASE, |
There are no data alignment restrictions on OP, any address is |
mp_limb_t *S1P, mp_size_t S1SIZE) |
allowed. |
Convert {S1P, S1SIZE} to a raw unsigned char array in base BASE. |
|
The string is not in ASCII; to convert it to printable format, add |
|
the ASCII codes for `0' or `A', depending on the base and range. |
|
There may be leading zeros in the string. |
|
|
|
The area at S1P is clobbered. |
Here's an example converting an array of `unsigned long' data, most |
|
significant element first and host byte order within each value. |
|
|
Return the number of characters in STR. |
unsigned long a[20]; |
|
mpz_t z; |
|
mpz_import (z, 20, 1, sizeof(a[0]), 0, 0, a); |
|
|
The area at STR has to have space for the largest possible number |
This example assumes the full `sizeof' bytes are used for data in |
represented by a S1SIZE long limb array, plus one extra character. |
the given type, which is usually true, and certainly true for |
|
`unsigned long' everywhere we know of. However on Cray vector |
|
systems it may be noted that `short' and `int' are always stored |
|
in 8 bytes (and with `sizeof' indicating that) but use only 32 or |
|
46 bits. The NAILS feature can account for this, by passing for |
|
instance `8*sizeof(int)-INT_BIT'. |
|
|
- Function: mp_size_t mpn_set_str (mp_limb_t *R1P, const char *STR, |
- Function: void *mpz_export (void *ROP, size_t *COUNT, int ORDER, int |
size_t STRSIZE, int BASE) |
SIZE, int ENDIAN, size_t NAILS, mpz_t OP) |
Convert the raw unsigned char array at STR of length STRSIZE to a |
Fill ROP with word data from OP. |
limb array {S1P, S1SIZE}. The base of STR is BASE. |
|
|
|
Return the number of limbs stored in R1P. |
The parameters specify the format of the data produced. Each word |
|
will be SIZE bytes and ORDER can be 1 for most significant word |
|
first or -1 for least significant first. Within each word ENDIAN |
|
can be 1 for most significant byte first, -1 for least significant |
|
first, or 0 for the native endianness of the host CPU. The most |
|
significant NAILS bits of each word are unused and set to zero, |
|
this can be 0 to produce full words. |
|
|
- Function: unsigned long int mpn_scan0 (const mp_limb_t *S1P, |
The number of words produced is written to `*COUNT'. ROP must |
unsigned long int BIT) |
have enough space for the data, or if ROP is `NULL' then a result |
Scan S1P from bit position BIT for the next clear bit. |
array of the necessary size is allocated using the current GMP |
|
allocation function (*note Custom Allocation::). In either case |
|
the return value is the destination used, ROP or the allocated |
|
block. |
|
|
It is required that there be a clear bit within the area at S1P at |
If OP is non-zero then the most significant word produced will be |
or beyond bit position BIT, so that the function has something to |
non-zero. If OP is zero then the count returned will be zero and |
return. |
nothing written to ROP. If ROP is `NULL' in this case, no block |
|
is allocated, just `NULL' is returned. |
|
|
- Function: unsigned long int mpn_scan1 (const mp_limb_t *S1P, |
There are no data alignment restrictions on ROP, any address is |
unsigned long int BIT) |
allowed. The sign of OP is ignored, just the absolute value is |
Scan S1P from bit position BIT for the next set bit. |
used. |
|
|
It is required that there be a set bit within the area at S1P at or |
When an application is allocating space itself the required size |
beyond bit position BIT, so that the function has something to |
can be determined with a calculation like the following. Since |
return. |
`mpz_sizeinbase' always returns at least 1, `count' here will be |
|
at least one, which avoids any portability problems with |
|
`malloc(0)', though if `z' is zero no space at all is actually |
|
needed. |
|
|
- Function: void mpn_random (mp_limb_t *R1P, mp_size_t R1SIZE) |
numb = 8*size - nail; |
- Function: void mpn_random2 (mp_limb_t *R1P, mp_size_t R1SIZE) |
count = (mpz_sizeinbase (z, 2) + numb-1) / numb; |
Generate a random number of length R1SIZE and store it at R1P. |
p = malloc (count * size); |
The most significant limb is always non-zero. `mpn_random' |
|
generates uniformly distributed limb data, `mpn_random2' generates |
|
long strings of zeros and ones in the binary representation. |
|
|
|
`mpn_random2' is intended for testing the correctness of the `mpn' |
|
routines. |
File: gmp.info, Node: Miscellaneous Integer Functions, Prev: Integer Import and Export, Up: Integer Functions |
|
|
- Function: unsigned long int mpn_popcount (const mp_limb_t *S1P, |
Miscellaneous Functions |
unsigned long int SIZE) |
======================= |
Count the number of set bits in {S1P, SIZE}. |
|
|
|
- Function: unsigned long int mpn_hamdist (const mp_limb_t *S1P, const |
- Function: int mpz_fits_ulong_p (mpz_t OP) |
mp_limb_t *S2P, unsigned long int SIZE) |
- Function: int mpz_fits_slong_p (mpz_t OP) |
Compute the hamming distance between {S1P, SIZE} and {S2P, SIZE}. |
- 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. |
|
|
- Function: int mpn_perfect_square_p (const mp_limb_t *S1P, mp_size_t |
- Macro: int mpz_odd_p (mpz_t OP) |
SIZE) |
- Macro: int mpz_even_p (mpz_t OP) |
Return non-zero iff {S1P, SIZE} is a perfect square. |
Determine whether OP is odd or even, respectively. Return |
|
non-zero if yes, zero if no. These macros evaluate their argument |
|
more than once. |
|
|
|
- Function: size_t mpz_size (mpz_t OP) |
File: gmp.info, Node: Random Number Functions, Next: BSD Compatible Functions, Prev: Low-level Functions, Up: Top |
Return the size of OP measured in number of limbs. If OP is zero, |
|
the returned value will be zero. |
|
|
Random Number Functions |
- Function: size_t mpz_sizeinbase (mpz_t OP, int BASE) |
*********************** |
Return the size of OP measured in number of digits in base BASE. |
|
The base may vary from 2 to 36. The sign of OP is ignored, just |
|
the absolute value is used. The result will be exact or 1 too |
|
big. If BASE is a power of 2, the result will always be exact. |
|
If OP is zero the return value is always 1. |
|
|
There are two groups of random number functions in GNU MP; older |
This function is useful in order to allocate the right amount of |
functions that call C library random number generators, rely on a global |
space before converting OP to a string. The right amount of |
state, and aren't very random; and newer functions that don't have these |
allocation is normally two more than the value returned by |
problems. The newer functions are self-contained, they accept a random |
`mpz_sizeinbase' (one extra for a minus sign and one for the |
state parameter that supplants global state, and generate good random |
null-terminator). |
numbers. |
|
|
|
The random state parameter is of the type `gmp_randstate_t'. It |
|
must be initialized by a call to one of the `gmp_randinit' functions |
File: gmp.info, Node: Rational Number Functions, Next: Floating-point Functions, Prev: Integer Functions, Up: Top |
(*Note Random State Initialization::). The initial seed is set using |
|
one of the `gmp_randseed' functions (*Note Random State |
|
Initialization::). |
|
|
|
The size of the seed determines the number of different sequences of |
Rational Number Functions |
random numbers that is possible to generate. The "quality" of the seed |
************************* |
is the randomness of a given seed compared to the previous seed used |
|
and affects the randomness of separate number sequences. |
|
|
|
The algorithm for assigning seed is critical if the generated random |
This chapter describes the GMP functions for performing arithmetic |
numbers are to be used for important applications, such as generating |
on rational numbers. These functions start with the prefix `mpq_'. |
cryptographic keys. |
|
|
|
The traditional method is to use the current system time for |
Rational numbers are stored in objects of type `mpq_t'. |
seeding. One has to be careful when using the current time though. If |
|
the application seeds the random functions very often, say several |
|
times per second, and the resolution of the system clock is |
|
comparatively low, like one second, the same sequence of numbers will |
|
be generated until the system clock ticks. Furthermore, the current |
|
system time is quite easy to guess, so a system depending on any |
|
unpredictability of the random number sequence should absolutely not |
|
use that as its only source for a seed value. |
|
|
|
On some systems there is a special device, often called |
All rational arithmetic functions assume operands have a canonical |
`/dev/random', which provides a source of somewhat random numbers more |
form, and canonicalize their result. The canonical from means that the |
usable as seed. |
denominator and the numerator have no common factors, and that the |
|
denominator is positive. Zero has the unique representation 0/1. |
|
|
The functions actually generating random functions are documented |
Pure assignment functions do not canonicalize the assigned variable. |
under "Miscellaneous Functions" in their respective function class: |
It is the responsibility of the user to canonicalize the assigned |
*Note Miscellaneous Integer Functions::, *Note Miscellaneous Float |
variable before any arithmetic operations are performed on that |
Functions::. |
variable. |
|
|
|
- Function: void mpq_canonicalize (mpq_t OP) |
|
Remove any factors that are common to the numerator and |
|
denominator of OP, and make the denominator positive. |
|
|
* Menu: |
* Menu: |
|
|
* Random State Initialization:: How to initialize a random state. |
* Initializing Rationals:: |
|
* Rational Conversions:: |
|
* Rational Arithmetic:: |
|
* Comparing Rationals:: |
|
* Applying Integer Functions:: |
|
* I/O of Rationals:: |
|
|
|
|
File: gmp.info, Node: Random State Initialization, Prev: Random Number Functions, Up: Random Number Functions |
File: gmp.info, Node: Initializing Rationals, Next: Rational Conversions, Prev: Rational Number Functions, Up: Rational Number Functions |
|
|
Random State Initialization |
Initialization and Assignment Functions |
=========================== |
======================================= |
|
|
See *Note Random Number Functions:: for a discussion on how to |
- Function: void mpq_init (mpq_t DEST_RATIONAL) |
choose the initial seed value passed to these functions. |
Initialize DEST_RATIONAL and set it to 0/1. Each variable should |
|
normally only be initialized once, or at least cleared out (using |
|
the function `mpq_clear') between each initialization. |
|
|
- Function: void gmp_randinit (gmp_randstate_t STATE, gmp_randalg_t |
- Function: void mpq_clear (mpq_t RATIONAL_NUMBER) |
ALG, ...) |
Free the space occupied by RATIONAL_NUMBER. Make sure to call this |
Initialize random state variable STATE. |
function for all `mpq_t' variables when you are done with them. |
|
|
ALG denotes what algorithm to use for random number generation. |
- Function: void mpq_set (mpq_t ROP, mpq_t OP) |
Use one of |
- Function: void mpq_set_z (mpq_t ROP, mpz_t OP) |
- GMP_RAND_ALG_LC -- Linear congruential. |
Assign ROP from OP. |
|
|
A fast generator defined by X = (aX + c) mod m. |
- Function: void mpq_set_ui (mpq_t ROP, unsigned long int OP1, |
|
unsigned long int OP2) |
|
- Function: void mpq_set_si (mpq_t ROP, signed long int OP1, unsigned |
|
long int OP2) |
|
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. |
|
|
A third argument SIZE of type unsigned long int is required. |
- Function: int mpq_set_str (mpq_t ROP, char *STR, int BASE) |
SIZE is the size of the largest good quality random number to |
Set ROP from a null-terminated string STR in the given BASE. |
be generated, expressed in number of bits. If the random |
|
generation functions are asked for a bigger random number |
|
than indicated by this parameter, two or more numbers of SIZE |
|
bits will be generated and concatenated, resulting in a "bad" |
|
random number. This can be used to generate big random |
|
numbers relatively cheap if the quality of randomness isn't |
|
of great importance. |
|
|
|
a, c, and m are picked from a table where the modulus (m) is |
The string can be an integer like "41" or a fraction like |
a power of 2 and the multiplier is congruent to 5 (mod 8). |
"41/152". The fraction must be in canonical form (*note Rational |
The choice is based on the SIZE parameter. The maximum SIZE |
Number Functions::), or if not then `mpq_canonicalize' must be |
supported by this algorithm is 128. If you need bigger |
called. |
random numbers, use your own scheme and call one of the other |
|
`gmp_randinit' functions. |
|
|
|
|
The numerator and optional denominator are parsed the same as in |
|
`mpz_set_str' (*note Assigning Integers::). White space is |
|
allowed in the string, and is simply ignored. The BASE can vary |
|
from 2 to 36, or if BASE is 0 then the leading characters are |
|
used: `0x' for hex, `0' for octal, or decimal otherwise. Note |
|
that this is done separately for the numerator and denominator, so |
|
for instance `0xEF/100' is 239/100, whereas `0xEF/0x100' is |
|
239/256. |
|
|
If ALG is 0 or GMP_RAND_ALG_DEFAULT, the default algorithm is |
The return value is 0 if the entire string is a valid number, or |
used. The default algorithm is typically a fast algorithm like |
-1 if not. |
the linear congruential and requires a third SIZE argument (see |
|
GMP_RAND_ALG_LC). |
|
|
|
When you're done with a STATE variable, call `gmp_randclear' to |
- Function: void mpq_swap (mpq_t ROP1, mpq_t ROP2) |
deallocate any memory allocated by this function. |
Swap the values ROP1 and ROP2 efficiently. |
|
|
`gmp_randinit' may set the following bits in GMP_ERRNO: |
|
* GMP_ERROR_UNSUPPORTED_ARGUMENT -- ALG is unsupported |
File: gmp.info, Node: Rational Conversions, Next: Rational Arithmetic, Prev: Initializing Rationals, Up: Rational Number Functions |
|
|
* GMP_ERROR_INVALID_ARGUMENT -- SIZE is too big |
Conversion Functions |
|
==================== |
|
|
- Function: void gmp_randinit_lc_2exp (gmp_randstate_t STATE, mpz_t A, |
- Function: double mpq_get_d (mpq_t OP) |
unsigned long int C, unsigned long int M2EXP) |
Convert OP to a `double'. |
|
|
Initialize random state variable STATE with given linear |
- Function: void mpq_set_d (mpq_t ROP, double OP) |
congruential scheme. |
- Function: void mpq_set_f (mpq_t ROP, mpf_t OP) |
|
Set ROP to the value of OP, without rounding. |
|
|
Parameters A, C, and M2EXP are the multiplier, adder, and modulus |
- Function: char * mpq_get_str (char *STR, int BASE, mpq_t OP) |
for the linear congruential scheme to use, respectively. The |
Convert OP to a string of digits in base BASE. The base may vary |
modulus is expressed as a power of 2, so that M = 2^M2EXP. |
from 2 to 36. The string will be of the form `num/den', or if the |
|
denominator is 1 then just `num'. |
|
|
The least significant bits of a random number generated by the |
If STR is `NULL', the result string is allocated using the current |
linear congruential algorithm where the modulus is a power of two |
allocation function (*note Custom Allocation::). The block will be |
are not very random. Therefore, the lower half of a random number |
`strlen(str)+1' bytes, that being exactly enough for the string and |
generated by an LC scheme initialized with this function is |
null-terminator. |
discarded. Thus, the size of a random number is M2EXP / 2 |
|
(rounded upwards) bits when this function has been used for |
|
initializing the random state. |
|
|
|
When you're done with a STATE variable, call `gmp_randclear' to |
If STR is not `NULL', it should point to a block of storage large |
deallocate any memory allocated by this function. |
enough for the result, that being |
|
|
- Function: void gmp_randseed (gmp_randstate_t STATE, mpz_t SEED) |
mpz_sizeinbase (mpq_numref(OP), BASE) |
- Function: void gmp_randseed_ui (gmp_randstate_t STATE, unsigned long |
+ mpz_sizeinbase (mpq_denref(OP), BASE) + 3 |
int SEED) |
|
Set the initial seed value. |
|
|
|
Parameter SEED is the initial random seed. The function |
The three extra bytes are for a possible minus sign, possible |
`gmp_randseed_ui' takes the SEED as an unsigned long int rather |
slash, and the null-terminator. |
than as an mpz_t. |
|
|
|
- Function: void gmp_randclear (gmp_randstate_t STATE) |
A pointer to the result string is returned, being either the |
Free all memory occupied by STATE. Make sure to call this |
allocated block, or the given STR. |
function for all `gmp_randstate_t' variables when you are done with |
|
them. |
|
|
|
|
|
File: gmp.info, Node: BSD Compatible Functions, Next: Custom Allocation, Prev: Random Number Functions, Up: Top |
File: gmp.info, Node: Rational Arithmetic, Next: Comparing Rationals, Prev: Rational Conversions, Up: Rational Number Functions |
|
|
Berkeley MP Compatible Functions |
Arithmetic Functions |
******************************** |
==================== |
|
|
These functions are intended to be fully compatible with the |
- Function: void mpq_add (mpq_t SUM, mpq_t ADDEND1, mpq_t ADDEND2) |
Berkeley MP library which is available on many BSD derived U*ix |
Set SUM to ADDEND1 + ADDEND2. |
systems. The `--enable-mpbsd' option must be used when building GNU MP |
|
to make these available (*note Installing GMP::). |
|
|
|
The original Berkeley MP library has a usage restriction: you cannot |
- Function: void mpq_sub (mpq_t DIFFERENCE, mpq_t MINUEND, mpq_t |
use the same variable as both source and destination in a single |
SUBTRAHEND) |
function call. The compatible functions in GNU MP do not share this |
Set DIFFERENCE to MINUEND - SUBTRAHEND. |
restriction--inputs and outputs may overlap. |
|
|
|
It is not recommended that new programs are written using these |
- Function: void mpq_mul (mpq_t PRODUCT, mpq_t MULTIPLIER, mpq_t |
functions. Apart from the incomplete set of functions, the interface |
MULTIPLICAND) |
for initializing `MINT' objects is more error prone, and the `pow' |
Set PRODUCT to MULTIPLIER times MULTIPLICAND. |
function collides with `pow' in `libm.a'. |
|
|
|
Include the header `mp.h' to get the definition of the necessary |
- Function: void mpq_mul_2exp (mpq_t ROP, mpq_t OP1, unsigned long int |
types and functions. If you are on a BSD derived system, make sure to |
OP2) |
include GNU `mp.h' if you are going to link the GNU `libmp.a' to your |
Set ROP to OP1 times 2 raised to OP2. |
program. This means that you probably need to give the -I<dir> option |
|
to the compiler, where <dir> is the directory where you have GNU `mp.h'. |
|
|
|
- Function: MINT * itom (signed short int INITIAL_VALUE) |
- Function: void mpq_div (mpq_t QUOTIENT, mpq_t DIVIDEND, mpq_t |
Allocate an integer consisting of a `MINT' object and dynamic limb |
DIVISOR) |
space. Initialize the integer to INITIAL_VALUE. Return a pointer |
Set QUOTIENT to DIVIDEND/DIVISOR. |
to the `MINT' object. |
|
|
|
- Function: MINT * xtom (char *INITIAL_VALUE) |
- Function: void mpq_div_2exp (mpq_t ROP, mpq_t OP1, unsigned long int |
Allocate an integer consisting of a `MINT' object and dynamic limb |
OP2) |
space. Initialize the integer from INITIAL_VALUE, a hexadecimal, |
Set ROP to OP1 divided by 2 raised to OP2. |
'\0'-terminate C string. Return a pointer to the `MINT' object. |
|
|
|
- Function: void move (MINT *SRC, MINT *DEST) |
- Function: void mpq_neg (mpq_t NEGATED_OPERAND, mpq_t OPERAND) |
Set DEST to SRC by copying. Both variables must be previously |
Set NEGATED_OPERAND to -OPERAND. |
initialized. |
|
|
|
- Function: void madd (MINT *SRC_1, MINT *SRC_2, MINT *DESTINATION) |
- Function: void mpq_abs (mpq_t ROP, mpq_t OP) |
Add SRC_1 and SRC_2 and put the sum in DESTINATION. |
Set ROP to the absolute value of OP. |
|
|
- Function: void msub (MINT *SRC_1, MINT *SRC_2, MINT *DESTINATION) |
- Function: void mpq_inv (mpq_t INVERTED_NUMBER, mpq_t NUMBER) |
Subtract SRC_2 from SRC_1 and put the difference in DESTINATION. |
Set INVERTED_NUMBER to 1/NUMBER. If the new denominator is zero, |
|
this routine will divide by zero. |
|
|
- Function: void mult (MINT *SRC_1, MINT *SRC_2, MINT *DESTINATION) |
|
Multiply SRC_1 and SRC_2 and put the product in DESTINATION. |
File: gmp.info, Node: Comparing Rationals, Next: Applying Integer Functions, Prev: Rational Arithmetic, Up: Rational Number Functions |
|
|
- Function: void mdiv (MINT *DIVIDEND, MINT *DIVISOR, MINT *QUOTIENT, |
Comparison Functions |
MINT *REMAINDER) |
==================== |
- Function: void sdiv (MINT *DIVIDEND, signed short int DIVISOR, MINT |
|
*QUOTIENT, signed short int *REMAINDER) |
|
Set QUOTIENT to DIVIDEND/DIVISOR, and REMAINDER to DIVIDEND mod |
|
DIVISOR. The quotient is rounded towards zero; the remainder has |
|
the same sign as the dividend unless it is zero. |
|
|
|
Some implementations of these functions work differently--or not |
- Function: int mpq_cmp (mpq_t OP1, mpq_t OP2) |
at all--for negative arguments. |
Compare OP1 and OP2. Return a positive value if OP1 > OP2, zero |
|
if OP1 = OP2, and a negative value if OP1 < OP2. |
|
|
- Function: void msqrt (MINT *OPERAND, MINT *ROOT, MINT *REMAINDER) |
To determine if two rationals are equal, `mpq_equal' is faster than |
Set ROOT to the truncated integer part of the square root of |
`mpq_cmp'. |
OPERAND. Set REMAINDER to OPERAND-ROOT*ROOT, (i.e., zero if |
|
OPERAND is a perfect square). |
|
|
|
If ROOT and REMAINDER are the same variable, the results are |
- Macro: int mpq_cmp_ui (mpq_t OP1, unsigned long int NUM2, unsigned |
undefined. |
long int DEN2) |
|
- Macro: int mpq_cmp_si (mpq_t OP1, long int NUM2, unsigned long int |
|
DEN2) |
|
Compare OP1 and NUM2/DEN2. Return a positive value if OP1 > |
|
NUM2/DEN2, zero if OP1 = NUM2/DEN2, and a negative value if OP1 < |
|
NUM2/DEN2. |
|
|
- Function: void pow (MINT *BASE, MINT *EXP, MINT *MOD, MINT *DEST) |
NUM2 and DEN2 are allowed to have common factors. |
Set DEST to (BASE raised to EXP) modulo MOD. |
|
|
|
- Function: void rpow (MINT *BASE, signed short int EXP, MINT *DEST) |
These functions are implemented as a macros and evaluate their |
Set DEST to BASE raised to EXP. |
arguments multiple times. |
|
|
- Function: void gcd (MINT *OPERAND1, MINT *OPERAND2, MINT *RES) |
- Macro: int mpq_sgn (mpq_t OP) |
Set RES to the greatest common divisor of OPERAND1 and OPERAND2. |
Return +1 if OP > 0, 0 if OP = 0, and -1 if OP < 0. |
|
|
- Function: int mcmp (MINT *OPERAND1, MINT *OPERAND2) |
This function is actually implemented as a macro. It evaluates its |
Compare OPERAND1 and OPERAND2. Return a positive value if |
arguments multiple times. |
OPERAND1 > OPERAND2, zero if OPERAND1 = OPERAND2, and a negative |
|
value if OPERAND1 < OPERAND2. |
|
|
|
- Function: void min (MINT *DEST) |
- Function: int mpq_equal (mpq_t OP1, mpq_t OP2) |
Input a decimal string from `stdin', and put the read integer in |
Return non-zero if OP1 and OP2 are equal, zero if they are |
DEST. SPC and TAB are allowed in the number string, and are |
non-equal. Although `mpq_cmp' can be used for the same purpose, |
ignored. |
this function is much faster. |
|
|
- Function: void mout (MINT *SRC) |
|
Output SRC to `stdout', as a decimal string. Also output a |
File: gmp.info, Node: Applying Integer Functions, Next: I/O of Rationals, Prev: Comparing Rationals, Up: Rational Number Functions |
newline. |
|
|
|
- Function: char * mtox (MINT *OPERAND) |
Applying Integer Functions to Rationals |
Convert OPERAND to a hexadecimal string, and return a pointer to |
======================================= |
the string. The returned string is allocated using the default |
|
memory allocation function, `malloc' by default. |
|
|
|
- Function: void mfree (MINT *OPERAND) |
The set of `mpq' functions is quite small. In particular, there are |
De-allocate, the space used by OPERAND. *This function should |
few functions for either input or output. The following functions give |
only be passed a value returned by `itom' or `xtom'.* |
direct access to the numerator and denominator of an `mpq_t'. |
|
|
|
Note that if an assignment to the numerator and/or denominator could |
|
take an `mpq_t' out of the canonical form described at the start of |
|
this chapter (*note Rational Number Functions::) then |
|
`mpq_canonicalize' must be called before any other `mpq' functions are |
|
applied to that `mpq_t'. |
|
|
|
- Macro: mpz_t mpq_numref (mpq_t OP) |
|
- 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. |
|
|
|
- Function: void mpq_get_num (mpz_t NUMERATOR, mpq_t RATIONAL) |
|
- Function: void mpq_get_den (mpz_t DENOMINATOR, mpq_t RATIONAL) |
|
- Function: void mpq_set_num (mpq_t RATIONAL, mpz_t NUMERATOR) |
|
- Function: void mpq_set_den (mpq_t RATIONAL, mpz_t DENOMINATOR) |
|
Get or set the numerator or denominator of a rational. These |
|
functions are equivalent to calling `mpz_set' with an appropriate |
|
`mpq_numref' or `mpq_denref'. Direct use of `mpq_numref' or |
|
`mpq_denref' is recommended instead of these functions. |
|
|
|
|
File: gmp.info, Node: Custom Allocation, Next: Contributors, Prev: BSD Compatible Functions, Up: Top |
File: gmp.info, Node: I/O of Rationals, Prev: Applying Integer Functions, Up: Rational Number Functions |
|
|
Custom Allocation |
Input and Output Functions |
***************** |
========================== |
|
|
By default, GMP uses `malloc', `realloc' and `free' for memory |
When using any of these functions, it's a good idea to include |
allocation. If `malloc' or `realloc' fails, GMP prints a message to |
`stdio.h' before `gmp.h', since that will allow `gmp.h' to define |
the standard error output and terminates execution. |
prototypes for these functions. |
|
|
Some applications might want to allocate memory in other ways, or |
Passing a `NULL' pointer for a STREAM argument to any of these |
might not want a fatal error when there is no more memory available. |
functions will make them read from `stdin' and write to `stdout', |
To accomplish this, you can specify alternative memory allocation |
respectively. |
functions. |
|
|
|
This can be done in the Berkeley compatibility library as well as |
- Function: size_t mpq_out_str (FILE *STREAM, int BASE, mpq_t OP) |
the main GMP library. |
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'. |
|
|
- Function: void mp_set_memory_functions ( |
Return the number of bytes written, or if an error occurred, |
void *(*ALLOC_FUNC_PTR) (size_t), |
return 0. |
void *(*REALLOC_FUNC_PTR) (void *, size_t, size_t), |
|
void (*FREE_FUNC_PTR) (void *, size_t)) |
|
Replace the current allocation functions from the arguments. If |
|
an argument is `NULL', the corresponding default function is |
|
retained. |
|
|
|
*Be sure to call this function only when there are no active GMP |
- Function: size_t mpq_inp_str (mpq_t ROP, FILE *STREAM, int BASE) |
objects allocated using the previous memory functions! Usually, |
Read a string of digits from STREAM and convert them to a rational |
that means that you have to call this function before any other |
in ROP. Any initial white-space characters are read and |
GMP function.* |
discarded. Return the number of characters read (including white |
|
space), or 0 if a rational could not be read. |
|
|
The functions you supply should fit the following declarations: |
The input can be a fraction like `17/63' or just an integer like |
|
`123'. Reading stops at the first character not in this form, and |
|
white space is not permitted within the string. If the input |
|
might not be in canonical form, then `mpq_canonicalize' must be |
|
called (*note Rational Number Functions::). |
|
|
- Function: void * allocate_function (size_t ALLOC_SIZE) |
The BASE can be between 2 and 36, or can be 0 in which case the |
This function should return a pointer to newly allocated space |
leading characters of the string determine the base, `0x' or `0X' |
with at least ALLOC_SIZE storage units. |
for hexadecimal, `0' for octal, or decimal otherwise. The leading |
|
characters are examined separately for the numerator and |
|
denominator of a fraction, so for instance `0x10/11' is 16/11, |
|
whereas `0x10/0x11' is 16/17. |
|
|
- Function: void * reallocate_function (void *PTR, size_t OLD_SIZE, |
|
size_t NEW_SIZE) |
File: gmp.info, Node: Floating-point Functions, Next: Low-level Functions, Prev: Rational Number Functions, Up: Top |
This function should return a pointer to newly allocated space of |
|
at least NEW_SIZE storage units, after copying at least the first |
|
OLD_SIZE storage units from PTR. It should also de-allocate the |
|
space at PTR. |
|
|
|
You can assume that the space at PTR was formerly returned from |
Floating-point Functions |
`allocate_function' or `reallocate_function', for a request for |
************************ |
OLD_SIZE storage units. |
|
|
|
- Function: void deallocate_function (void *PTR, size_t SIZE) |
GMP floating point numbers are stored in objects of type `mpf_t' and |
De-allocate the space pointed to by PTR. |
functions operating on them have an `mpf_' prefix. |
|
|
You can assume that the space at PTR was formerly returned from |
The mantissa of each float has a user-selectable precision, limited |
`allocate_function' or `reallocate_function', for a request for |
only by available memory. Each variable has its own precision, and |
SIZE storage units. |
that can be increased or decreased at any time. |
|
|
(A "storage unit" is the unit in which the `sizeof' operator returns |
The exponent of each float is a fixed precision, one machine word on |
the size of an object, normally an 8 bit byte.) |
most systems. In the current implementation the exponent is a count of |
|
limbs, so for example on a 32-bit system this means a range of roughly |
|
2^-68719476768 to 2^68719476736, or on a 64-bit system this will be |
|
greater. Note however `mpf_get_str' can only return an exponent which |
|
fits an `mp_exp_t' and currently `mpf_set_str' doesn't accept exponents |
|
bigger than a `long'. |
|
|
|
Each variable keeps a size for the mantissa data actually in use. |
|
This means that if a float is exactly represented in only a few bits |
|
then only those bits will be used in a calculation, even if the |
|
selected precision is high. |
|
|
|
All calculations are performed to the precision of the destination |
|
variable. Each function is defined to calculate with "infinite |
|
precision" followed by a truncation to the destination precision, but |
|
of course the work done is only what's needed to determine a result |
|
under that definition. |
|
|
|
The precision selected for a variable is a minimum value, GMP may |
|
increase it a little to facilitate efficient calculation. Currently |
|
this means rounding up to a whole limb, and then sometimes having a |
|
further partial limb, depending on the high limb of the mantissa. But |
|
applications shouldn't be concerned by such details. |
|
|
|
The mantissa in stored in binary, as might be imagined from the fact |
|
precisions are expressed in bits. One consequence of this is that |
|
decimal fractions like 0.1 cannot be represented exactly. The same is |
|
true of plain IEEE `double' floats. This makes both highly unsuitable |
|
for calculations involving money or other values that should be exact |
|
decimal fractions. (Suitably scaled integers, or perhaps rationals, |
|
are better choices.) |
|
|
|
`mpf' functions and variables have no special notion of infinity or |
|
not-a-number, and applications must take care not to overflow the |
|
exponent or results will be unpredictable. This might change in a |
|
future release. |
|
|
|
Note that the `mpf' functions are _not_ intended as a smooth |
|
extension to IEEE P754 arithmetic. In particular results obtained on |
|
one computer often differ from the results on a computer with a |
|
different word size. |
|
|
|
* Menu: |
|
|
|
* Initializing Floats:: |
|
* Assigning Floats:: |
|
* Simultaneous Float Init & Assign:: |
|
* Converting Floats:: |
|
* Float Arithmetic:: |
|
* Float Comparison:: |
|
* I/O of Floats:: |
|
* Miscellaneous Float Functions:: |
|
|
|
|
File: gmp.info, Node: Contributors, Next: References, Prev: Custom Allocation, Up: Top |
File: gmp.info, Node: Initializing Floats, Next: Assigning Floats, Prev: Floating-point Functions, Up: Floating-point Functions |
|
|
Contributors |
Initialization Functions |
************ |
======================== |
|
|
Torbjorn Granlund wrote the original GMP library and is still |
- Function: void mpf_set_default_prec (unsigned long int PREC) |
developing and maintaining it. Several other individuals and |
Set the default precision to be *at least* PREC bits. All |
organizations have contributed to GMP in various ways. Here is a list |
subsequent calls to `mpf_init' will use this precision, but |
in chronological order: |
previously initialized variables are unaffected. |
|
|
Gunnar Sjoedin and Hans Riesel helped with mathematical problems in |
- Function: unsigned long int mpf_get_default_prec (void) |
early versions of the library. |
Return the default default precision actually used. |
|
|
Richard Stallman contributed to the interface design and revised the |
An `mpf_t' object must be initialized before storing the first value |
first version of this manual. |
in it. The functions `mpf_init' and `mpf_init2' are used for that |
|
purpose. |
|
|
Brian Beuning and Doug Lea helped with testing of early versions of |
- Function: void mpf_init (mpf_t X) |
the library and made creative suggestions. |
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'. |
|
|
John Amanatides of York University in Canada contributed the function |
- Function: void mpf_init2 (mpf_t X, unsigned long int PREC) |
`mpz_probab_prime_p'. |
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. |
|
|
Paul Zimmermann of Inria sparked the development of GMP 2, with his |
- Function: void mpf_clear (mpf_t X) |
comparisons between bignum packages. |
Free the space occupied by X. Make sure to call this function for |
|
all `mpf_t' variables when you are done with them. |
|
|
Ken Weber (Kent State University, Universidade Federal do Rio Grande |
Here is an example on how to initialize floating-point variables: |
do Sul) contributed `mpz_gcd', `mpz_divexact', `mpn_gcd', and |
{ |
`mpn_bdivmod', partially supported by CNPq (Brazil) grant 301314194-2. |
mpf_t x, y; |
|
mpf_init (x); /* use default precision */ |
|
mpf_init2 (y, 256); /* precision _at least_ 256 bits */ |
|
... |
|
/* Unless the program is about to exit, do ... */ |
|
mpf_clear (x); |
|
mpf_clear (y); |
|
} |
|
|
Per Bothner of Cygnus Support helped to set up GMP to use Cygnus' |
The following three functions are useful for changing the precision |
configure. He has also made valuable suggestions and tested numerous |
during a calculation. A typical use would be for adjusting the |
intermediary releases. |
precision gradually in iterative algorithms like Newton-Raphson, making |
|
the computation precision closely match the actual accurate part of the |
|
numbers. |
|
|
Joachim Hollman was involved in the design of the `mpf' interface, |
- Function: unsigned long int mpf_get_prec (mpf_t OP) |
and in the `mpz' design revisions for version 2. |
Return the current precision of OP, in bits. |
|
|
Bennet Yee contributed the functions `mpz_jacobi' and `mpz_legendre'. |
- Function: void mpf_set_prec (mpf_t ROP, unsigned long int PREC) |
|
Set the precision of ROP to be *at least* PREC bits. The value in |
|
ROP will be truncated to the new precision. |
|
|
Andreas Schwab contributed the files `mpn/m68k/lshift.S' and |
This function requires a call to `realloc', and so should not be |
`mpn/m68k/rshift.S'. |
used in a tight loop. |
|
|
The development of floating point functions of GNU MP 2, were |
- Function: void mpf_set_prec_raw (mpf_t ROP, unsigned long int PREC) |
supported in part by the ESPRIT-BRA (Basic Research Activities) 6846 |
Set the precision of ROP to be *at least* PREC bits, without |
project POSSO (POlynomial System SOlving). |
changing the memory allocated. |
|
|
GNU MP 2 was finished and released by SWOX AB (formerly known as TMG |
PREC must be no more than the allocated precision for ROP, that |
Datakonsult), Swedenborgsgatan 23, SE-118 27 STOCKHOLM, SWEDEN, in |
being the precision when ROP was initialized, or in the most recent |
cooperation with the IDA Center for Computing Sciences, USA. |
`mpf_set_prec'. |
|
|
Robert Harley of Inria, France and David Seal of ARM, England, |
The value in ROP is unchanged, and in particular if it had a higher |
suggested clever improvements for population count. |
precision than PREC it will retain that higher precision. New |
|
values written to ROP will use the new PREC. |
|
|
Robert Harley also wrote highly optimized Karatsuba and 3-way Toom |
Before calling `mpf_clear' or the full `mpf_set_prec', another |
multiplication functions for GMP 3. He also contributed the ARM |
`mpf_set_prec_raw' call must be made to restore ROP to its original |
assembly code. |
allocated precision. Failing to do so will have unpredictable |
|
results. |
|
|
Torsten Ekedahl of the Mathematical department of Stockholm |
`mpf_get_prec' can be used before `mpf_set_prec_raw' to get the |
University provided significant inspiration during several phases of |
original allocated precision. After `mpf_set_prec_raw' it |
the GMP development. His mathematical expertise helped improve several |
reflects the PREC value set. |
algorithms. |
|
|
|
Paul Zimmermann wrote the Burnikel-Ziegler division code, the REDC |
`mpf_set_prec_raw' is an efficient way to use an `mpf_t' variable |
code, the REDC-based mpz_powm code, and the FFT multiply code. The |
at different precisions during a calculation, perhaps to gradually |
ECMNET project Paul is organizing has been a driving force behind many |
increase precision in an iteration, or just to use various |
of the optimization of GMP 3. |
different precisions for different purposes during a calculation. |
|
|
Linus Nordberg wrote the new configure system based on autoconf and |
|
implemented the new random functions. |
File: gmp.info, Node: Assigning Floats, Next: Simultaneous Float Init & Assign, Prev: Initializing Floats, Up: Floating-point Functions |
|
|
Kent Boortz made the Macintosh port. |
Assignment Functions |
|
==================== |
|
|
Kevin Ryde wrote a lot of very high quality x86 code, optimized for |
These functions assign new values to already initialized floats |
most CPU variants. He also made countless other valuable contributions. |
(*note Initializing Floats::). |
|
|
Steve Root helped write the optimized alpha 21264 assembly code. |
- Function: void mpf_set (mpf_t ROP, mpf_t OP) |
|
- Function: void mpf_set_ui (mpf_t ROP, unsigned long int OP) |
|
- Function: void mpf_set_si (mpf_t ROP, signed long int OP) |
|
- Function: void mpf_set_d (mpf_t ROP, double OP) |
|
- Function: void mpf_set_z (mpf_t ROP, mpz_t OP) |
|
- Function: void mpf_set_q (mpf_t ROP, mpq_t OP) |
|
Set the value of ROP from OP. |
|
|
GNU MP 3.1 was finished and released by Torbjorn Granlund and Kevin |
- Function: int mpf_set_str (mpf_t ROP, char *STR, int BASE) |
Ryde. Torbjorn's work was partially funded by the IDA Center for |
Set the value of ROP from the string in STR. The string is of the |
Computing Sciences, USA. |
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 decimal |
|
point expected is taken from the current locale, on systems |
|
providing `localeconv'. |
|
|
(This list is chronological, not ordered after significance. If you |
The argument BASE may be in the ranges 2 to 36, or -36 to -2. |
have contributed to GMP but are not listed above, please tell |
Negative values are used to specify that the exponent is in |
<tege@swox.com> about the omission!) |
decimal. |
|
|
|
Unlike the corresponding `mpz' function, the base will not be |
|
determined from the leading characters of the string if BASE is 0. |
|
This is so that numbers like `0.23' are not interpreted as octal. |
|
|
|
White space is allowed in the string, and is simply ignored. |
|
[This is not really true; white-space is ignored in the beginning |
|
of the string and within the mantissa, but not in other places, |
|
such as after a minus sign or in the exponent. We are considering |
|
changing the definition of this function, making it fail when |
|
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 |
|
really want it to accept "3 14" as meaning 314 as it does now?] |
|
|
|
This function returns 0 if the entire string is a valid number in |
|
base BASE. Otherwise it returns -1. |
|
|
|
- Function: void mpf_swap (mpf_t ROP1, mpf_t ROP2) |
|
Swap ROP1 and ROP2 efficiently. Both the values and the |
|
precisions of the two variables are swapped. |
|
|
|
|
File: gmp.info, Node: References, Next: Concept Index, Prev: Contributors, Up: Top |
File: gmp.info, Node: Simultaneous Float Init & Assign, Next: Converting Floats, Prev: Assigning Floats, Up: Floating-point Functions |
|
|
References |
Combined Initialization and Assignment Functions |
********** |
================================================ |
|
|
* Donald E. Knuth, "The Art of Computer Programming", vol 2, |
For convenience, GMP provides a parallel series of |
"Seminumerical Algorithms", 3rd edition, Addison-Wesley, 1988. |
initialize-and-set functions which initialize the output and then store |
|
the value there. These functions' names have the form `mpf_init_set...' |
|
|
* John D. Lipson, "Elements of Algebra and Algebraic Computing", The |
Once the float has been initialized by any of the `mpf_init_set...' |
Benjamin Cummings Publishing Company Inc, 1981. |
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! |
|
|
* Richard M. Stallman, "Using and Porting GCC", Free Software |
- Function: void mpf_init_set (mpf_t ROP, mpf_t OP) |
Foundation, 1999, available online |
- Function: void mpf_init_set_ui (mpf_t ROP, unsigned long int OP) |
`http://www.gnu.org/software/gcc/onlinedocs/', and in the GCC |
- Function: void mpf_init_set_si (mpf_t ROP, signed long int OP) |
package `ftp://ftp.gnu.org/pub/gnu/gcc/'. |
- Function: void mpf_init_set_d (mpf_t ROP, double OP) |
|
Initialize ROP and set its value from OP. |
|
|
* Peter L. Montgomery, "Modular Multiplication Without Trial |
The precision of ROP will be taken from the active default |
Division", in Mathematics of Computation, volume 44, number 170, |
precision, as set by `mpf_set_default_prec'. |
April 1985. |
|
|
|
* Torbjorn Granlund and Peter L. Montgomery, "Division by Invariant |
- Function: int mpf_init_set_str (mpf_t ROP, char *STR, int BASE) |
Integers using Multiplication", in Proceedings of the SIGPLAN |
Initialize ROP and set its value from the string in STR. See |
PLDI'94 Conference, June 1994. Available online, |
`mpf_set_str' above for details on the assignment operation. |
`ftp://ftp.cwi.nl/pub/pmontgom/divcnst.psa4.gz' (and .psl.gz too). |
|
|
|
* Tudor Jebelean, "An algorithm for exact division", Journal of |
Note that ROP is initialized even if an error occurs. (I.e., you |
Symbolic Computation, v. 15, 1993, pp. 169-180. Research report |
have to call `mpf_clear' for it.) |
version available online |
|
`ftp://ftp.risc.uni-linz.ac.at/pub/techreports/1992/92-35.ps.gz' |
|
|
|
* Kenneth Weber, "The accelerated integer GCD algorithm", ACM |
The precision of ROP will be taken from the active default |
Transactions on Mathematical Software, v. 21 (March), 1995, pp. |
precision, as set by `mpf_set_default_prec'. |
111-122. |
|
|
|
* Christoph Burnikel and Joachim Ziegler, "Fast Recursive Division", |
|
Max-Planck-Institut fuer Informatik Research Report |
File: gmp.info, Node: Converting Floats, Next: Float Arithmetic, Prev: Simultaneous Float Init & Assign, Up: Floating-point Functions |
MPI-I-98-1-022, |
|
`http://www.mpi-sb.mpg.de/~ziegler/TechRep.ps.gz'. |
|
|
|
* Alfred J. Menezes, Paul C. van Oorschot and Scott A. Vanstone, |
Conversion Functions |
"Handbook of Applied Cryptography", |
==================== |
`http://cacr.math.uwaterloo.ca/hac/'. |
|
|
|
* Henri Cohen, "A Course in Computational Algebraic Number Theory", |
- Function: double mpf_get_d (mpf_t OP) |
Graduate Texts in Mathematics number 138, Springer-Verlag, 1993. |
Convert OP to a `double'. |
Errata available online |
|
`http://www.math.u-bordeaux.fr/~cohen' |
|
|
|
|
- Function: double mpf_get_d_2exp (signed long int *EXP, mpf_t OP) |
|
Find D and EXP such that D times 2 raised to EXP, with |
|
0.5<=abs(D)<1, is a good approximation to OP. This is similar to |
|
the standard C function `frexp'. |
|
|
|
- Function: long mpf_get_si (mpf_t OP) |
|
- Function: unsigned long mpf_get_ui (mpf_t OP) |
|
Convert OP to a `long' or `unsigned long', truncating any fraction |
|
part. If OP is too big for the return type, the result is |
|
undefined. |
|
|
|
See also `mpf_fits_slong_p' and `mpf_fits_ulong_p' (*note |
|
Miscellaneous Float Functions::). |
|
|
|
- Function: char * mpf_get_str (char *STR, mp_exp_t *EXPPTR, int BASE, |
|
size_t N_DIGITS, mpf_t OP) |
|
Convert OP to a string of digits in base BASE. BASE can be 2 to |
|
36. Up to N_DIGITS digits will be generated. Trailing zeros are |
|
not returned. No more digits than can be accurately represented |
|
by OP are ever generated. If N_DIGITS is 0 then that accurate |
|
maximum number of digits are generated. |
|
|
|
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 N_DIGITS + 2 |
|
bytes, that being enough for the mantissa, a possible minus sign, |
|
and a null-terminator. When N_DIGITS is 0 to get all significant |
|
digits, an application won't be able to know the space required, |
|
and STR should be `NULL' in that case. |
|
|
|
The generated string is a fraction, with an implicit radix point |
|
immediately to the left of the first digit. The applicable |
|
exponent is written through the EXPPTR pointer. For example, the |
|
number 3.1416 would be returned as string "31416" and exponent 1. |
|
|
|
When OP is zero, an empty string is produced and the exponent |
|
returned is 0. |
|
|
|
A pointer to the result string is returned, being either the |
|
allocated block or the given STR. |
|
|
|
|
File: gmp.info, Node: Concept Index, Next: Function Index, Prev: References, Up: Top |
File: gmp.info, Node: Float Arithmetic, Next: Float Comparison, Prev: Converting Floats, Up: Floating-point Functions |
|
|
Concept Index |
Arithmetic Functions |
************* |
==================== |
|
|
* Menu: |
- Function: void mpf_add (mpf_t ROP, mpf_t OP1, mpf_t OP2) |
|
- Function: void mpf_add_ui (mpf_t ROP, mpf_t OP1, unsigned long int |
|
OP2) |
|
Set ROP to OP1 + OP2. |
|
|
* ABI: ABI and ISA. |
- Function: void mpf_sub (mpf_t ROP, mpf_t OP1, mpf_t OP2) |
* About this manual: Introduction to GMP. |
- Function: void mpf_ui_sub (mpf_t ROP, unsigned long int OP1, mpf_t |
* alloca: Build Options. |
OP2) |
* Allocation of memory: Custom Allocation. |
- Function: void mpf_sub_ui (mpf_t ROP, mpf_t OP1, unsigned long int |
* Anonymous FTP of latest version: Getting the Latest Version of GMP. |
OP2) |
* Arithmetic functions <1>: Float Arithmetic. |
Set ROP to OP1 - OP2. |
* Arithmetic functions <2>: Rational Arithmetic. |
|
* Arithmetic functions: Integer Arithmetic. |
- Function: void mpf_mul (mpf_t ROP, mpf_t OP1, mpf_t OP2) |
* Assignment functions <1>: Assigning Floats. |
- Function: void mpf_mul_ui (mpf_t ROP, mpf_t OP1, unsigned long int |
* Assignment functions: Assigning Integers. |
OP2) |
* Basics: GMP Basics. |
Set ROP to OP1 times OP2. |
* Berkeley MP compatible functions: BSD Compatible Functions. |
|
* Binomial coefficient functions: Number Theoretic Functions. |
Division is undefined if the divisor is zero, and passing a zero |
* Bit manipulation functions: Integer Logic and Bit Fiddling. |
divisor to the divide functions will make these functions intentionally |
* Bit shift left: Integer Arithmetic. |
divide by zero. This lets the user handle arithmetic exceptions in |
* Bit shift right: Integer Division. |
these functions in the same manner as other arithmetic exceptions. |
* Bits per limb: Useful Macros and Constants. |
|
* BSD MP compatible functions: BSD Compatible Functions. |
- Function: void mpf_div (mpf_t ROP, mpf_t OP1, mpf_t OP2) |
* Bug reporting: Reporting Bugs. |
- Function: void mpf_ui_div (mpf_t ROP, unsigned long int OP1, mpf_t |
* Build notes for binary packaging: Notes for Package Builds. |
OP2) |
* Build notes for particular systems: Notes for Particular Systems. |
- Function: void mpf_div_ui (mpf_t ROP, mpf_t OP1, unsigned long int |
* Build options: Build Options. |
OP2) |
* Build problems known: Known Build Problems. |
Set ROP to OP1/OP2. |
* Comparison functions <1>: Integer Comparisons. |
|
* Comparison functions <2>: Comparing Rationals. |
- Function: void mpf_sqrt (mpf_t ROP, mpf_t OP) |
* Comparison functions: Float Comparison. |
- Function: void mpf_sqrt_ui (mpf_t ROP, unsigned long int OP) |
* Compatibility with older versions: Compatibility with older versions. |
Set ROP to the square root of OP. |
* Conditions for copying GNU MP: Copying. |
|
* Configuring GMP: Installing GMP. |
- Function: void mpf_pow_ui (mpf_t ROP, mpf_t OP1, unsigned long int |
* Constants: Useful Macros and Constants. |
OP2) |
* Contributors: Contributors. |
Set ROP to OP1 raised to the power OP2. |
* Conventions for variables: GMP Variable Conventions. |
|
* Conversion functions <1>: Converting Integers. |
- Function: void mpf_neg (mpf_t ROP, mpf_t OP) |
* Conversion functions: Converting Floats. |
Set ROP to -OP. |
* Copying conditions: Copying. |
|
* CPUs supported: Introduction to GMP. |
- Function: void mpf_abs (mpf_t ROP, mpf_t OP) |
* Custom allocation: Custom Allocation. |
Set ROP to the absolute value of OP. |
* Demonstration programs: Build Options. |
|
* Division functions <1>: Integer Division. |
- Function: void mpf_mul_2exp (mpf_t ROP, mpf_t OP1, unsigned long int |
* Division functions <2>: Rational Arithmetic. |
OP2) |
* Division functions: Float Arithmetic. |
Set ROP to OP1 times 2 raised to OP2. |
* Exact division functions: Integer Division. |
|
* Example programs: Build Options. |
- Function: void mpf_div_2exp (mpf_t ROP, mpf_t OP1, unsigned long int |
* Exponentiation functions <1>: Float Arithmetic. |
OP2) |
* Exponentiation functions: Integer Exponentiation. |
Set ROP to OP1 divided by 2 raised to OP2. |
* Extended GCD: Number Theoretic Functions. |
|
* Factorial functions: Number Theoretic Functions. |
|
* Fibonacci sequence functions: Number Theoretic Functions. |
File: gmp.info, Node: Float Comparison, Next: I/O of Floats, Prev: Float Arithmetic, Up: Floating-point Functions |
* Float arithmetic functions: Float Arithmetic. |
|
* Float assignment functions: Assigning Floats. |
Comparison Functions |
* Float comparison functions: Float Comparison. |
==================== |
* Float conversion functions: Converting Floats. |
|
* Float functions: Floating-point Functions. |
- Function: int mpf_cmp (mpf_t OP1, mpf_t OP2) |
* Float init and assign functions: Simultaneous Float Init & Assign. |
- Function: int mpf_cmp_d (mpf_t OP1, double OP2) |
* Float initialization functions: Initializing Floats. |
- Function: int mpf_cmp_ui (mpf_t OP1, unsigned long int OP2) |
* Float input and output functions: I/O of Floats. |
- Function: int mpf_cmp_si (mpf_t OP1, signed long int OP2) |
* Float miscellaneous functions: Miscellaneous Float Functions. |
Compare OP1 and OP2. Return a positive value if OP1 > OP2, zero |
* Floating-point functions: Floating-point Functions. |
if OP1 = OP2, and a negative value if OP1 < OP2. |
* Floating-point number: Nomenclature and Types. |
|
* FTP of latest version: Getting the Latest Version of GMP. |
- Function: int mpf_eq (mpf_t OP1, mpf_t OP2, unsigned long int op3) |
* Function classes: Function Classes. |
Return non-zero if the first OP3 bits of OP1 and OP2 are equal, |
* GMP version number: Useful Macros and Constants. |
zero otherwise. I.e., test of OP1 and OP2 are approximately equal. |
* gmp.h: GMP Basics. |
|
* Greatest common divisor functions: Number Theoretic Functions. |
Caution: Currently only whole limbs are compared, and only in an |
* Home page: Introduction to GMP. |
exact fashion. In the future values like 1000 and 0111 may be |
* I/O functions <1>: I/O of Rationals. |
considered the same to 3 bits (on the basis that their difference |
* I/O functions <2>: I/O of Integers. |
is that small). |
* I/O functions: I/O of Floats. |
|
* Initialization and assignment functions <1>: Initializing Rationals. |
- Function: void mpf_reldiff (mpf_t ROP, mpf_t OP1, mpf_t OP2) |
* Initialization and assignment functions <2>: Simultaneous Float Init & Assign. |
Compute the relative difference between OP1 and OP2 and store the |
* Initialization and assignment functions: Simultaneous Integer Init & Assign. |
result in ROP. This is abs(OP1-OP2)/OP1. |
* Initialization functions <1>: Initializing Integers. |
|
* Initialization functions: Initializing Floats. |
- Macro: int mpf_sgn (mpf_t OP) |
* Input functions <1>: I/O of Floats. |
Return +1 if OP > 0, 0 if OP = 0, and -1 if OP < 0. |
* Input functions <2>: I/O of Rationals. |
|
* Input functions: I/O of Integers. |
This function is actually implemented as a macro. It evaluates |
* Installing GMP: Installing GMP. |
its arguments multiple times. |
* Integer: Nomenclature and Types. |
|
* Integer arithmetic functions: Integer Arithmetic. |
|
* Integer assignment functions: Assigning Integers. |
File: gmp.info, Node: I/O of Floats, Next: Miscellaneous Float Functions, Prev: Float Comparison, Up: Floating-point Functions |
* Integer bit manipulation functions: Integer Logic and Bit Fiddling. |
|
* Integer comparison functions: Integer Comparisons. |
Input and Output Functions |
* Integer conversion functions: Converting Integers. |
========================== |
* Integer division functions: Integer Division. |
|
* Integer exponentiation functions: Integer Exponentiation. |
Functions that perform input from a stdio stream, and functions that |
* Integer functions: Integer Functions. |
output to a stdio stream. Passing a `NULL' pointer for a STREAM |
* Integer init and assign: Simultaneous Integer Init & Assign. |
argument to any of these functions will make them read from `stdin' and |
* Integer initialization functions: Initializing Integers. |
write to `stdout', respectively. |
* Integer input and output functions: I/O of Integers. |
|
* Integer miscellaneous functions: Miscellaneous Integer Functions. |
When using any of these functions, it is a good idea to include |
* Integer random number functions: Integer Random Numbers. |
`stdio.h' before `gmp.h', since that will allow `gmp.h' to define |
* Integer root functions: Integer Roots. |
prototypes for these functions. |
* Introduction: Introduction to GMP. |
|
* ISA: ABI and ISA. |
- Function: size_t mpf_out_str (FILE *STREAM, int BASE, size_t |
* Jabobi symbol functions: Number Theoretic Functions. |
N_DIGITS, mpf_t OP) |
* Kronecker symbol functions: Number Theoretic Functions. |
Print OP to STREAM, as a string of digits. Return the number of |
* Latest version of GMP: Getting the Latest Version of GMP. |
bytes written, or if an error occurred, return 0. |
* Least common multiple functions: Number Theoretic Functions. |
|
* Libtool versioning: Notes for Package Builds. |
The mantissa is prefixed with an `0.' and is in the given BASE, |
* Limb: Nomenclature and Types. |
which may vary from 2 to 36. An exponent then printed, separated |
* Limb size: Useful Macros and Constants. |
by an `e', or if BASE is greater than 10 then by an `@'. The |
* Logical functions: Integer Logic and Bit Fiddling. |
exponent is always in decimal. The decimal point follows the |
* Low-level functions: Low-level Functions. |
current locale, on systems providing `localeconv'. |
* Mailing list: Introduction to GMP. |
|
* Memory allocation: Custom Allocation. |
Up to N_DIGITS will be printed from the mantissa, except that no |
* Miscellaneous float functions: Miscellaneous Float Functions. |
more digits than are accurately representable by OP will be |
* Miscellaneous integer functions: Miscellaneous Integer Functions. |
printed. N_DIGITS can be 0 to select that accurate maximum. |
* Miscellaneous rational functions: Miscellaneous Rational Functions. |
|
* Modular inverse functions: Number Theoretic Functions. |
- Function: size_t mpf_inp_str (mpf_t ROP, FILE *STREAM, int BASE) |
* mp.h: BSD Compatible Functions. |
Read a string in base BASE from STREAM, and put the read float in |
* Multi-threading: GMP and Reentrancy. |
ROP. The string is of the form `M@N' or, if the base is 10 or |
* Nomenclature: Nomenclature and Types. |
less, alternatively `MeN'. `M' is the mantissa and `N' is the |
* Number theoretic functions: Number Theoretic Functions. |
exponent. The mantissa is always in the specified base. The |
* Numerator and denominator: Applying Integer Functions. |
exponent is either in the specified base or, if BASE is negative, |
* Output functions <1>: I/O of Floats. |
in decimal. The decimal point expected is taken from the current |
* Output functions <2>: I/O of Integers. |
locale, on systems providing `localeconv'. |
* Output functions: I/O of Rationals. |
|
* Packaged builds: Notes for Package Builds. |
The argument BASE may be in the ranges 2 to 36, or -36 to -2. |
* Parameter conventions: GMP Variable Conventions. |
Negative values are used to specify that the exponent is in |
* Precision of floats: Floating-point Functions. |
decimal. |
* Prime testing functions: Number Theoretic Functions. |
|
* Random number functions <1>: Integer Random Numbers. |
Unlike the corresponding `mpz' function, the base will not be |
* Random number functions: Random Number Functions. |
determined from the leading characters of the string if BASE is 0. |
* Random number state: Random State Initialization. |
This is so that numbers like `0.23' are not interpreted as octal. |
* Rational arithmetic functions: Rational Arithmetic. |
|
* Rational comparison functions: Comparing Rationals. |
Return the number of bytes read, or if an error occurred, return 0. |
* Rational init and assign: Initializing Rationals. |
|
* Rational input and output functions: I/O of Rationals. |
|
* Rational miscellaneous functions: Miscellaneous Rational Functions. |
|
* Rational number: Nomenclature and Types. |
|
* Rational number functions: Rational Number Functions. |
|
* Rational numerator and denominator: Applying Integer Functions. |
|
* Reentrancy: GMP and Reentrancy. |
|
* References: References. |
|
* Reporting bugs: Reporting Bugs. |
|
* Root extraction functions <1>: Float Arithmetic. |
|
* Root extraction functions: Integer Roots. |
|
* Stack overflow segfaults: Build Options. |
|
* Stripped libraries: Known Build Problems. |
|
* Thread safety: GMP and Reentrancy. |
|
* Types: Nomenclature and Types. |
|
* Upward compatibility: Compatibility with older versions. |
|
* Useful macros and constants: Useful Macros and Constants. |
|
* User-defined precision: Floating-point Functions. |
|
* Variable conventions: GMP Variable Conventions. |
|
* Version number: Useful Macros and Constants. |
|
* Web page: Introduction to GMP. |
|
|
|