NAME

Math::GMPz - perl interface to the GMP library's integer (mpz) functions.

DEPENDENCIES

This module needs the GMP C library - available from:
http://gmplib.org

DESCRIPTION

A bignum module utilising the Gnu MP (GMP) library.
Basically this module simply wraps nearly all of
the integer functions provided by that library.
The documentation below extensively plagiarises
the documentation at http://gmplib.org.
See the Math::GMPz test suite for examples of
usage.

SYNOPSIS

use Math::GMPz qw(:mpz :primes :supp);

my $string = 'fa9eeeeeeeeeeeeea1234dcbaef1';
my $base = 16;

# Create the Math::GMPz object
my $bn1 = Rmpz_init_set_str($string, $base);

# Create another Math::GMPz object that holds
# an initial value of zero, but has enough 
# memory allocated to store a 131-bit number.
# If 131 bits turns out to be insufficient, it
# doesn't matter - additional memory is allocated
# automatically to Math::GMPz objects as needed
# by the GMP library.
my $bn2 = Rmpz_init2(131);

# Create another Math::GMPz object initialised to 0.
my $bn3 = Rmpz_init();

# or use the new() function:
my $bn4 = Math::GMPz->new(12345);

# Perform some operations ... see 'FUNCTIONS' below.

.
.

# print out the value held by $bn1 (in octal):
print Rmpz_get_str($bn1, 8), "\n";

# print out the value held by $bn1 (in decimal):
print Rmpz_get_str($bn1, 10);

# print out the value held by $bn1 (in base 29)
# using the (alternative) Rmpz_out_str()
# function. (This function doesn't print a newline.)
Rmpz_out_str($bn1, 29);

MEMORY MANAGEMENT

Objects created with the Rmpz_init* functions have
been blessed into package Math::GMPz. They will
therefore be automatically cleaned up by the DESTROY()
function whenever they go out of scope.

For each Rmpz_init* function there is a corresponding function
called Rmpz_init*_nobless which returns an
unblessed object. If you create Math::GMPz objects
using the '_nobless' versions, it will then be up to you
to clean up the memory associated with these objects by
calling Rmpz_clear($op) for each object. Alternatively
such objects will be cleaned up when the script ends.
I don't know why you would want to create unblessed 
objects. The point is that you can if you want to.  

FUNCTIONS

  See the GMP documentation at http://gmplib.org.

  These next 3 functions are demonstrated above:
  $rop   = Rmpz_init_set_str($str, $base); # 1 < $base < 37
  $rop   = Rmpz_init2($bits); # $bits > 0
  $str = Rmpz_get_str($r, $base); # 1 < $base < 37 

  The following functions are simply wrappers around a GMP
  function of the same name. eg. Rmpz_swap() is a wrapper around
  mpz_swap().

  "$rop", "$op1", "$op2", etc. are Math::GMPz objects - the
  return values of one of the Rmpz_init* functions.
  They are in fact references to GMP structures.
  The "$rop" argument(s) contain the result(s) of the calculation
  being done, the "$op" argument(s) being the input(s) into that 
  calculation.
  Generally, $rop, $op1, $op2, etc. can be the same perl variable,
  though usually they will be distinct perl variables
  referencing distinct GMP structures.
  Eg something like Rmpz_add($r1, $r1, $r1),
  where $r1 *is* the same reference to the same GMP structure,
  would add $r1 to itself and store the result in $r1. Think of it
  as $r1 += $r1. Otoh, Rmpz_add($r1, $r2, $r3), where each of the
  arguments is a different reference to a different GMP structure
  would add $r2 to $r3 and store the result in $r1. Think of it as
  $r1 = $r2 + $r3.
  Mostly, the first argument is the argument that 
  stores the result and subsequent arguments provide the input values.
  Exceptions to this can be found in some of the functions that
  actually return a value, and, eg., the div_qr functions (which
  yield both quotient and remainder as their first *two* arguments). 
  Like I say, see the GMP manual for details. I hope it's 
  intuitively obvious or quickly becomes so. Also see the test
  suite that comes with the distro for some examples of usage.

  "$ui" means any integer that will fit into a C 'unsigned long int'.

  "$si" means any integer that will fit into a C 'signed long int'.

  "$double" means any number (not necessarily integer) that will fit
  into a C 'double'.

  "$bool" means a value (usually a 'signed long int') in which
  the only interest is whether it evaluates as true or not.

  "$str" simply means a string of symbols that represent a number,
  eg "1234567890987654321234567" which might be a base 10 number,
  or "zsa34760sdfgq123r5" which would have to represent at least
  a base 36 number (because "z" is a valid digit only in bases 36
  and higher). Valid bases for GMP numbers are 0 and 2..62 .

  "$NULL" is $Math::GMPz::NULL (the NULL mpz type).

  #####################

  INITIALIZING INTEGERS

  Normally, a variable should be initialized once only or at least be
  cleared, using `Rmpz_clear', between initializations.
  'DESTROY' (which calls 'Rmpz_clear') is automatically called on 
  blessed objects whenever they go out of scope.

  First read the section 'MEMORY MANAGEMENT' (above).

  $rop = Math::GMPz::new();
  $rop = Math::GMPz->new();
  $rop = new Math::GMPz();
  $rop = Rmpz_init();
  $rop = Rmpz_init_nobless();
   Initialize $rop, and set its value to 0.

  $rop = Rmpz_init2($bits);
  $rop = Rmpz_init2_nobless($bits);
   Initialize $rop, with space for $bits bits, and set its value
   to 0. $bits is only the initial space, $rop will grow
   automatically if necessary, for subsequent values stored.
   `Rmpz_init2' makes it possible to avoid such reallocations if a
   maximum size is known in advance.

  Rmpz_realloc2($rop, $ui);
   Change the space allocated for $rop to $ui bits.  The value in
   $rop is preserved if it fits, or is set to 0 if not.

  ##################

  ASSIGNING INTEGERS


  Rmpz_set($rop, $op); 
   Assign the value in $op to $rop.

  Rmpz_set_si($rop, $si);
   Assign the 'signed int', $si, to $rop.

  Rmpz_set_ui($rop, $ui);
   Assign the 'unsigned int', $ui, to $rop.

  Rmpz_set_d($rop, $double);
   Assign $double to $rop. (Truncate to an integer if necessary.)

  Rmpz_set_q($rop, $q); # $q is a Math::GMPq or GMP::Mpq object
   Assign $q to $rop. (Truncate to an integer if necessary.)

  Rmpz_set_f($rop, $f); # $f is a Math::GMPf or GMP::Mpf object
   Assign $f to $rop. (Truncate to an integer if necessary.)

  Rmpz_set_str($rop, $str, $base); 
   Set $rop to the base $base value of $str. $base may vary from
   2 to 62.  If $base is 0, the actual base is determined from the
   leading characters: if the first two characters are "0x" or "0X",
   hexadecimal is assumed, otherwise if the first character is "0",
   octal is assumed, otherwise decimal is assumed.

  Rmpz_swap($rop1, $rop2); # swap the values

  ######################################

  COMBINED INITIALIZATION AND ASSIGNMENT

  NOTE: Do NOT use these functions if $rop has already
  been initialised. Instead use the Rmpz_set* functions 
  in 'Assigning Integers' (above)

  First read the section 'MEMORY MANAGEMENT' (above).

  $rop = Math::GMPz->new($arg);
  $rop = Math::GMPz::new($arg);
  $rop = new Math::GMPz($arg);
   Returns a Math::GMPz object with the value of $arg.
   $arg can be either an integer (signed integer, unsigned
   integer, signed fraction or unsigned fraction) or a string that 
   represents a numeric value. If $arg is a string, an optional
   additional argument that specifies the base of the number can be
   supplied to new(). If base is 0 (or not supplied) then the leading
   characters of the string are used: 0x or 0X for hex, 0b or 0B for
   binary, 0 for octal, or decimal otherwise. Legal values for the 
   base are 0 and 2..62 .

  $rop = Rmpz_init_set($op);
  $rop = Rmpz_init_set_nobless($op);
  $rop = Rmpz_init_set_ui($ui);
  $rop = Rmpz_init_set_ui_nobless($ui);
  $rop = Rmpz_init_set_si($si);
  $rop = Rmpz_init_set_si_nobless($si);
  $rop = Rmpz_init_set_d($double);
  $rop = Rmpz_init_set_d_nobless($double);
  $rop = Rmpz_init_set_str($str, $base);
  $rop = Rmpz_init_set_str_nobless($str, $base);

  ###################

  CONVERTING INTEGERS


  $ui = Rmpz_get_ui($op);
   Return the value of $op as an `unsigned long'.
   The sign of $op is ignored, only the absolute value is used.

  $si = Rmpz_get_si($op); 
   If $op fits into a `signed long int' return the value of $op.
   Otherwise return the least significant part of OP, with the
   same sign as $op. If $op is too big to fit in a `signed long
   int', the returned result is probably not very useful.  To
   find out if the value will fit, use the function 
   `Rmpz_fits_slong_p'.

  $double = Rmpz_get_d($op);
    Place the value of $op into a normal perl scalar.

  ($double, $si) = Rmpz_get_d_2exp($op); 
   Find $double and $si such that $double times 2 raised to 
   $si, with 0.5<=abs($double)<1, is a good approximation to $op.

  $ul = Rmpz_getlimbn($op, $ui);
   Return limb number $ui from $op.  The sign of $op is ignored,
   just the absolute value is used.  The least significant limb 
   is number 0. `Rmpz_size' can be used to find how many limbs
   make up $op. `Rmpz_getlimbn' returns zero if $ui is outside the
   range 0 to `Rmpz_size($op)-1'.

  $str = Rmpz_get_str($op, $base);
   Convert $op to a string of digits in base $base.
   The base may vary from -36..-2, 2..62. 

  ##################

  INTEGER ARITHMETIC

  Rmpz_add($rop, $op1, $op2); 
  Rmpz_add_ui($rop, $op, $ui); 
   $rop = 2nd arg + 3rd arg.

  Rmpz_sub($rop, $op1, $op2); 
  Rmpz_sub_ui($rop, $op, $ui); 
  Rmpz_ui_sub($rop, $ui, $op);
   $rop = 2nd arg - 3rd arg.

  Rmpz_mul($rop, $op1, $op2); 
  Rmpz_mul_si($rop, $op, $si); 
  Rmpz_mul_ui($rop, $op, $ui);
   $rop = 2nd arg * 3rd arg.

  Rmpz_addmul($rop, $op1, $op2);
  Rmpz_addmul_ui($rop, $op, $ui);
   $rop += 2nd arg * 3rd arg.

  Rmpz_submul($rop, $op1, $op2); 
  Rmpz_submul_ui($rop, $op, $ui);
   $rop -= 2nd arg * 3rd arg.

  Rmpz_mul_2exp($rop, $op, $ui);
   Set $rop to $op * (2 ** $ui).  This operation can
   also be defined as a left shift by $ui bits.

  Rmpz_div_2exp($rop, $op, $ui); # Same as Rmpz_fdiv_q_2exp
   Set $rop to $op / (2 ** $ui).  This operation can
   also be defined as a right shift by $ui bits.

  Rmpz_neg($rop, $op);
   $rop = -$op.

  Rmpz_abs($rop, $op);
   $rop = abs($op).

  ################

  INTEGER DIVISION

  `cdiv' rounds quotient up towards +infinity, and remainder
         will have the opposite sign to divisor.
        The `c' stands for "ceil".

  `fdiv' rounds quotient down towards -infinity, and remainder
         will have the same sign as divisor.
         The `f' stands for "floor".

  `tdiv' rounds quotient towards zero, and remainder
         will have the same sign as the number. 
         The `t' stands for "truncate".

  Rmpz_div($rop, $op1, $op2); # Same as Rmpz_fdiv_q
  Rmpz_cdiv_q($rop, $op1, $op2);
  Rmpz_fdiv_q($rop, $op1, $op2);
  Rmpz_tdiv_q($rop, $op1, $op2); 
   $rop = $op1 / $op2.

  Rmpz_cdiv_r($rop, $op1, $op2);
  Rmpz_fdiv_r($rop, $op1, $op2);
  Rmpz_tdiv_r($rop, $op1, $op2);
   $rop = $op1 % $op2.

  Rmpz_divmod($rop1, $rop2m $op1, $op2); # Same as Rmpz_fdiv_qr
  Rmpz_cdiv_qr($rop1, $rop2, $op1, $op2);
  Rmpz_fdiv_qr($rop1, $rop2, $op1, $op2);
  Rmpz_tdiv_qr($rop1, $rop1, $op1, $op2);
   $rop1 = $op1 / $op2.
   $rop2 = $op1 % $op2.

  $ul = Rmpz_div_ui($rop, $op, $ui); # Same as Rmpz_fdiv_q_ui
  $ul = Rmpz_cdiv_q_ui($rop, $op, $ui);
  $ul = Rmpz_fdiv_q_ui($rop, $op, $ui);
  $ul = Rmpz_tdiv_q_ui($rop, $op, $ui);
   $rop = $op / $ui.
   $ul = $op % $ui.

  $ul = Rmpz_cdiv_r_ui($rop, $op, $ui);
  $ul = Rmpz_fdiv_r_ui($rop $op, $ui);
  $ul = Rmpz_tdiv_r_ui($rop, $op, $ui);
   $rop = $op % $ui.
   $ul = $op % $ui.

  $ul = Rmpz_divmod_ui($rop1, $rop2, $op1, $ui); # Same as Rmpz_fdiv_qr_ui
  $ul = Rmpz_cdiv_qr_ui($rop1, $rop2, $op, $ui);
  $ul = Rmpz_fdiv_qr_ui($rop1, $rop2, $op, $ui);
  $ul = Rmpz_tdiv_qr_ui($rop1, $rop2, $op, $ui);
   $rop1 = $op / $ui.
   $rop2 = $op % $ui.
   $ul = $op % $ui.

  $ul = Rmpz_cdiv_ui($op, $ui);
  $ul = Rmpz_fdiv_ui($op, $ui);
  $ul = Rmpz_tdiv_ui($op, $ui);
   $ul = $op % $ui.

  Rmpz_cdiv_q_2exp($rop, $op, $ui);
  Rmpz_fdiv_q_2exp($rop, $op, $ui);
  Rmpz_tdiv_q_2exp($rop, $op, $ui);
   $rop = $op / (2 ** $ui). ie $rop is $op right-shifted
   by $ui bits.

  Rmpz_mod_2exp($rop, $op, $ui); # Same as Rmpz_fdiv_r_2exp
  Rmpz_cdiv_r_2exp($rop, $op, $ui); 
  Rmpz_fdiv_r_2exp($rop, $op, $ui);
  Rmpz_tdiv_r_2exp($rop, $op, $ui); 
   $rop = $op % (2 ** $ui).

  Rmpz_mod($rop, $op1, $op2);
   $rop = $op1 % $op2. The sign of the divisor is ignored.
   The result is never negative.

  $ul = Rmpz_mod_ui($rop, $op, $ui); 
   $rop = $op % $ui.
   $ul = $op % $ui.
   The sign of the divisor is ignored. The result is never negative.   

  Rmpz_divexact($rop, $op1, $op2); 
  Rmpz_divexact_ui($rop, $op, $ui); 
   $rop = 2nd arg / 3rd arg.
   These 2 functions provide correct results only when it
   is known that the 3rd arg divides the 2nd arg.

  $bool = Rmpz_divisible_p($op1, $op2); 
  $bool = Rmpz_divisible_ui_p($op, $ui);
  $bool = Rmpz_divisible_2exp_p($op, $ui);
   Return non-zero if 1st arg is exactly divisible by 2nd arg,
   or in the case of `Rmpz_divisible_2exp_p' by 2 ** 2nd arg.

  $bool = Rmpz_congruent_p($op1, $op2, $op3); 
  $bool = Rmpz_congruent_ui_p($op, $ui, $ui); 
  $bool = Rmpz_congruent_2exp_p($op1, $op2, $ui);
   Return non-zero if 1st arg is congruent to 2nd arg modulo 
   3rd arg, or in the case of `Rmpz_congruent_2exp_p' modulo
   2 ** 3rd arg.

  ######################

  INTEGER EXPONENTIATION

  Rmpz_powm($rop, $op1, $op2, $op3);
  Rmpz_powm_sec($rop, $op1, $op2, $op3); # gmp-5.0 and later only
   $rop = ($op1 ** $op2 ) % $op3 
   In the case of Rmpz_powm_sec, $op2 must be > 0, and $op3 must
   be odd.

  Rmpz_powm_ui($rop, $op1, $ui, $op2);
   $rop = ($op1 ** $ui) % $op2 

  Rmpz_pow_ui($rop, $op, $ui);
   $rop = $op ** $ui

  Rmpz_ui_pow_ui($rop, $ui1, $ui2);
   $rop = $ui1 ** $ui2

  #############

  INTEGER ROOTS

  Rmpz_root($rop, $op, $ui);
   $rop = $op ** (1 / $ui).

  Rmpz_sqrt($rop, $op);
   $rop = $op ** 0.5.

  Rmpz_sqrtrem($rop1, $rop2, $op);
   $rop1 = $op ** 0.5.
   $op = $rop2 + ($rop1 ** 2). 

  $bool = Rmpz_perfect_power_p($op);
   Return zero if $op is not a perfect power.
   Else return non-zero.

  $bool = Rmpz_perfect_square_p($op);
   Return zero if $op is not a perfect square.
   Else return non-zero.

  ##########################

  NUMBER THEORETIC FUNCTIONS

  $si = Rmpz_probab_prime_p($rop, $ui); 
   Determine whether $rop is prime. Return 2 if $rop is
   definitely prime, return 1 if $rop is probably prime 
   (without being certain), or return 0 if $rop is definitely
   composite. This function does some trial divisions, then
   some Miller-Rabin probabilistic primality tests.  $ui 
   controls how many such tests are done, 5 to 10 is a 
   reasonable number, more will reduce the chances of a
   composite being returned as "probably prime".
   Miller-Rabin and similar tests can be more properly called
   compositeness tests.  Numbers which fail are known to be 
   composite but those which pass might be prime or might be
   composite. Only a few composites pass, hence those which
   pass are considered probably prime.

  Rmpz_nextprime($rop, $op); 
   This function uses a probabilistic algorithm to identify
   primes. For practical purposes it's adequate, the chance
   of a composite passing will be extremely small.

  Rmpz_gcd($rop, $op1, $op2); 
   Set $rop to the greatest common divisor of $op1 and $op2. 
   The result is always positive even if one or both input
   operands are negative.

  $ui2 = Rmpz_gcd_ui($rop, $op, $ui1);  # GCD in $ui2 & $rop
  $ui2 = Rmpz_gcd_ui($NULL, $op, $ui1); # GCD in $ui2 only
   Compute the greatest common divisor of $op and $ui1.
   Store the result in $rop (iff $rop is not $Math::GMPz::NULL).
   If the result is small enough to fit in an `unsigned long
   int', it is returned.  If the result does not fit, 0 is
   returned, and the result is equal to the argument $op.
   Note that the result will always fit if $ui1 is non-zero.

  Rmpz_gcdext($rop1, $rop2, $rop3, $op1, $op2);
  Rmpz_gcdext($rop1, $rop2, $NULL, $op1, $op2);
   Set $rop1 to the greatest common divisor of $op1 and $op2,
   and in addition set $rop2 and $rop3 to coefficients
   satisfying $op1*$rop2 + $op2*$rop3 = $rop1. $rop1 is
   always positive, even if one or both of $op1 and $op2 
   are negative.
   If $rop3 is $Math::GMPz::NULL then that value is not
   computed.

  Rmpz_lcm($rop, $op1, $op2); 
  Rmpz_lcm_ui($rop, $op, $ui);
   Set $rop to the least common multiple of 2nd and 3rd args.
   $rop is always positive, irrespective of the signs of the
   2nd and 3rd args. $rop will be zero if either 
   2nd or 3rd arg is zero.

  $bool = Rmpz_invert($rop, $op1, $op2);
   Compute the inverse of $op1 modulo $op2 and put the result
   in $rop. If the inverse exists, the return value is 
   non-zero and $rop will satisfy 0 <= $rop < $op2.
   If an inverse doesn't exist the return value is zero and
   $rop is undefined.

  $si = Rmpz_jacobi($op1, $op2);
   Calculate the Jacobi symbol ($op1/$op2). This is defined
   only for $op2 odd.

  $si = Rmpz_legendre($op1, $op2); 
   Calculate the Legendre symbol ($op1/$op2). This is defined
   only for $op2 an odd positive prime, and for such $op2
   it's identical to the Jacobi symbol.

  $si = Rmpz_kronecker($op1, $op2); 
  $si = Rmpz_kronecker_si($op, $si); 
  $si = Rmpz_kronecker_ui($op, $ui); 
  $si = Rmpz_si_kronecker($si, $op); 
  $si = Rmpz_ui_kronecker($ui, $op);
   Calculate the Jacobi symbol (1st arg/2nd arg) with the 
   Kronecker extension (a/2)=(2/a) when a odd, or (a/2)=0
   when a even. When 2nd arg is odd the Jacobi symbol and
   Kronecker symbol are identical, so `mpz_kronecker_ui'
   etc can be used for mixed precision Jacobi symbols too.

  $ui = Rmpz_remove($rop, $op1, $op2); 
   Remove all occurrences of the factor $op2 from $op1 and
   store the result in $rop.  The return value is how many
   such occurrences were removed.

  Rmpz_fac_ui($rop, $ui); 
   Set $rop to the factorial of $ui.

  Rmpz_2fac_ui($rop, $ui); # Available only with gmp-5.1.0
                           # or later
   Set $rop to the double-factorial (n!!) of $ui.

  Rmpz_mfac_uiui($rop, $ui1, $u2); # Available only with
                                   # gmp-5.1.0 or later 
   Set $rop to the $ui2-multi-factorial of $ui1, $ui2.

  Rmpz_primorial_ui($rop, $ui); # Available only with gmp-5.1.0
                                # or later
   Set $rop to the primorial of $ui, i.e. the product of all
   positive prime numbers smaller than or equal to $ui.

  Rmpz_bin_ui($rop, $op, $ui); 
  Rmpz_bin_uiui($rop, $ui, $ui); 
   Compute the binomial coefficient 2nd arg over 3rd arg and
   store the result in $rop.  Negative values of 2nd arg are
   supported by `mpz_bin_ui', using the identity
   bin(-n,k) = (-1)^k * bin(n+k-1,k), see Knuth volume 1
   section 1.2.6 part G.

  Rmpz_fib_ui($rop, $ui); 
  Rmpz_fib2_ui($rop1, $rop2, $ui);
   `Rmpz_fib_ui' sets $rop to to F[$ui], the $ui'th 
   Fibonacci number. `Rmpz_fib2_ui' sets $rop1 to F[$ui],
   and $rop2 to F[$ui-1]. These functions are designed for
   calculating isolated Fibonacci numbers.  When a sequence
   of values is wanted it's best to start with `Rmpz_fib2_ui'
   and iterate the defining F[n+1]=F[n]+F[n-1] or similar.

  Rmpz_lucnum_ui($rop, $ui); 
  Rmpz_lucnum2_ui($rop1, $rop2, $ui); 
   `Rmpz_lucnum_ui' sets $rop to to L[$ui], the $ui'th 
   Lucas number. `Rmpz_lucnum2_ui' sets $rop1 to L[$ui],
   and $rop2 to L[$ui-1]. These functions are designed for
   calculating isolated Lucas numbers.  When a sequence of
   values is wanted it's best to start with `Rmpz_lucnum2_ui'
   and iterate the defining L[n+1]=L[n]+L[n-1] or similar.

  ###################

  INTEGER COMPARISONS

  $si = Rmpz_cmp($op1, $op2); 
  $si = Rmpz_cmp_d($op, $double); 
  $si = Rmpz_cmp_si($op, $si); 
  $si = Rmpz_cmp_ui($op, $ui);
   Compare 1st and 2nd args.  Return a positive value if
   1st arg > 2nd arg, zero if 1st arg = 2nd arg, or a 
   negative value if 1st arg < 2nd arg.

  $si = Rmpz_cmpabs($op1, $op2); 
  $si = Rmpz_cmpabs_d($op, $double); 
  $si = Rmpz_cmpabs_ui($op, $ui);
   Compare the absolute values of 1st and 2nd args.  Return 
   a positive value if abs(1st arg) > abs(2nd arg), zero if
   abs(1st arg) = abs(2nd arg), or a negative value if
   abs(1st arg) < abs(2nd arg). 

  $si = Rmpz_sgn($op); 
   Return +1 if $op > 0, 0 if $opP = 0, and -1 if $op < 0.

  ##############################

  INTEGER LOGIC AND BIT FIDDLING

  Rmpz_and($rop, $op1, $op2);
   Set $rop to $op1 logical-and $op2.

  Rmpz_ior($rop, $op1, $op2); 
   Set $rop to $op1 inclusive-or $op2.

  Rmpz_xor($rop, $op1, $op2);
   Set $rop to $op1 exclusive-or $op2.

  Rmpz_com($rop, $op); 
   Set $rop to the one's complement of $op.

  $ui = Rmpz_popcount($op); 
   If $op>=0, return the population count of $op, which is the 
   number of 1 bits in the binary representation.  If $op<0, the
   number of 1s is infinite, and the return value is MAX_ULONG,
   the largest possible `unsigned long'.

  $ui = Rmpz_hamdist($op1, $op2);
   If $op1 and $op2 are both >=0 or both <0, return the hamming
   distance between the two operands, which is the number of bit
   positions where $op1 and $op2 have different bit values.  If
   one operand is >=0 and the other <0 then the number of bits
   different is infinite, and the return value is MAX_ULONG, 
   the largest possible `unsigned long'.

  $ui = Rmpz_scan0($op, $ui); 
  $ui = Rmpz_scan1($op, $ui);
   Scan $op, starting from bit index $ui, towards more
   significant bits, until the first 0 or 1 bit (respectively)
   is found.  Return the index of the found bit. If the bit at
   index $ui is already what's sought, then $ui is returned.
   If there's no bit found, then MAX_ULONG is returned.  This
   will happen in `Rmpz_scan0' past the end of a positive 
   number, or `Rmpz_scan1' past the end of a negative. 

  Rmpz_setbit($rop, $ui);
   Set bit index $ui in $rop. 

  Rmpz_clrbit($rop, $ui); 
   Clear bit index $ui in $rop.

  $si = Rmpz_tstbit($op, $ui);
   Test bit index $ui in $op and return 0 or 1 accordingly.

  ###############

  I/O of INTEGERS

  $bytes_written = Rmpz_out_str([$prefix,] $op, $base [, $suffix]);
   BEST TO USE TRmpz_out_str INSTEAD.
   Output $op to STDOUT, as a string of digits in base $base.
   The base may vary from -36..-2, 2..62. Return the number 
   of bytes written, or if an error occurred,return 0.
   The optional arguments ($prefix and $suffix) are strings
   that will be prepended/appended to the mpz_out_str output.
   $bytes_written does not include the bytes contained in
   $prefix and $suffix.

  $bytes_written = TRmpz_out_str([$prefix,] $stream, $base, $op, [, $suffix]);
   As for Rmpz_out_str, except that there's the capability to print
   to somewhere other than STDOUT. Note that the order of the args
   is different (to match the order of the mpz_out_str args).
   To print to STDERR:
      TRmpz_out_str(*stderr, $base, $digits, $op);
   To print to an open filehandle (let's call it FH):
      TRmpz_out_str(\*FH, $base, $digits, $op);

  $bytes_written = Rmpz_out_raw(\*FH, $op);
   Output $op to filehandle FH, 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 output 
   can be read with mpz_inp_raw.

  $bytes_read = Rmpz_inp_str($rop, $base);
   BEST TO USE TRmpz_inp_str instead.
   Input a string in base $base from STDIN, and put the read
   integer in $rop. The base may vary from 2 to 62.  If $base
   is 0, the actual base is determined from the leading
   characters: if the first two characters are `0x' or `0X',
   hexadecimal is assumed, otherwise if the first character is
  `0', octal is assumed, otherwise decimal is assumed.
   Return the number of bytes read, or if an error occurred, return 0.

  $bytes_read = TRmpz_inp_str($rop, $stream, $base);
   As for Rmpz_inp_str, except that there's the capability to read
   from somewhere other than STDIN.
   To read from STDIN:
      TRmpz_inp_str($rop, *stdin, $base);
   To read from an open filehandle (let's call it FH):
      TRmpz_inp_str($rop, \*FH, $base);

   $bytes_read = Rmpz_inp_raw($rop, \*FH);
    Input from filehandle FH in the format written by Rmpz_out_raw,
    and put the result in $rop. Return the number of bytes read, or
    if an error occurred, return 0.


  #######################

  RANDOM NUMBER FUNCTIONS

  In the random number functions, @r is an array of 
  Math::GMPz objects (one for each random number that is
  required). $how_many is the number of random numbers you 
  want and must be equal to scalar(@r). $bits is simply the
  number of random bits required. Before calling the random
  number functions, $state must be initialised and seeded.

  $state = rand_init($op); # $op is the seed.
   Initialises and seeds $state, ready for use with the random
   number functions. However, $state has not been blessed into
   any package, and therefore does not get cleaned up when it 
   goes out of scope. To avoid memory leaks you therefore need
   to call 'rand_clear($state);' once you have finished with it
   and before it goes out of scope. Also, it uses the default
   algorithm. Consider using the following initialisation and
   seeding routines - they provide a choice of algorithm, and
   there's no need to call rand_clear() when you've finished with
   them.

  $state = zgmp_randinit_default();
   This is the Math::GMPz interface to the gmp library function
  'gmp_randinit_default'.
   $state is blessed into package Math::GMPz::Random and will be
   automatically cleaned up when it goes out of scope.
   Initialize $state with a default algorithm. This will be a
   compromise between speed and randomness, and is recommended for
   applications with no special requirements. Currently this is
   the gmp_randinit_mt function (Mersenne Twister algorithm).

  $state = zgmp_randinit_mt();
   This is the Math::GMPz interface to the gmp library function
  'gmp_randinit_mt'.
   Currently identical to zgmp_randinit_default().

  $state = zgmp_randinit_lc_2exp($mpz, $ui, $m2exp);
   This is the Math::GMPz interface to the gmp library function
  'gmp_randinit_lc_2exp'.
   $state is blessed into package Math::GMPz::Random and will be
   automatically cleaned up when it goes out of scope.
   Initialize $state with a linear congruential algorithm
   X = ($mpz*X + $ui) mod (2 ** $m2exp). The low bits of X in this
   algorithm are not very random. The least significant bit will have a
   period no more than 2, and the second bit no more than 4, etc. For
   this reason only the high half of each X is actually used. 
   When a random number of more than m2exp/2 bits is to be generated,
   multiple iterations of the recurrence are used and the results
   concatenated. 

  $state = zgmp_randinit_lc_2exp_size($ui);
   This is the Math::GMPz interface to the gmp library function
  'gmp_randinit_lc_2exp_size'.
   $state is blessed into package Math::GMPz::Random and will be
   automatically cleaned up when it goes out of scope.
   Initialize state for a linear congruential algorithm as per
   gmp_randinit_lc_2exp. a, c and m2exp are selected from a table,
   chosen so that $ui bits (or more) of each X will be used,
   ie. m2exp/2 >= $ui. 
   If $ui is bigger than the table data provides then the function fails
   and dies with an appropriate error message. The maximum value for $ui
   currently supported is 128. 

  $state2 = zgmp_randinit_set($state1);
   This is the Math::GMPz interface to the gmp library function
  'gmp_randinit_set'.
   $state2 is blessed into package Math::GMPz::Random and will be
   automatically cleaned up when it goes out of scope.
   Initialize $state2 with a copy of the algorithm and state from
   $state1.

  $state = zgmp_randinit_default_nobless();
  $state = zgmp_randinit_mt_nobless();
  $state = zgmp_randinit_lc_2exp_nobless($mpz, $ui, $m2exp);
  $state2 = zgmp_randinit_set_nobless($state1);
   As for the above comparable function, but $state is not blessed into
   any package. (Generally not useful - but they're available if you
   want them.)

  zgmp_randseed($state, $mpz);
  zgmp_randseed_ui($state, $ui);
   These are the Math::GMPz interfaces to the gmp library functions
  'gmp_randseed' and 'gmp_randseed_ui'.
   Seed an initialised (but not yet seeded) $state with $mpz/$ui. 

  $ui = zgmp_urandomb_ui($state, $bits);
   This is the Math::GMPz interface to the gmp library function
   'gmp_urandomb_ui'.
   Return a uniformly distributed random number of $bits bits, ie. in
   the range 0 to 2 ** ($bits - 1) inclusive. $bits must be less than or
   equal to the number of bits in an unsigned long. 

  $ui2 = zgmp_urandomm_ui($state, $ui1);
   This is the Math::GMPz interface to the gmp library function
   'gmp_urandomm_ui'.
   Return a uniformly distributed random number in the range 0 to
   $ui1 - 1, inclusive.   

  Rmpz_urandomm(@r, $state, $mpz, $how_many);
   Generate $how_many uniform random integers in the range
   0 to $op-1, inclusive.

  Rmpz_urandomb(@r, $state, $bits, $how_many);
   Generate $how_many uniformly distributed random integers
   in the range 0 to 2**($bits-1), inclusive.

  Rmpz_rrandomb(@r, $state, $bits, $how_many);
   Generate $how_many random integers with long strings of 
   zeros and ones in the binary representation. Useful for 
   testing functions and algorithms, since this kind of random
   numbers have proven to be more likely to trigger corner-case bugs.
   The random number will be in the range 0 to 2**($bits-1), inclusive.

  zgmp_randclear($state);
  rand_clear($state);
   Destroys $state, as also does Math::GMPz::Random::DESTROY - three
   identical functions.
   Use only if $state is an unblessed object - ie if it was initialised
   using rand_init() or one of the zgmp_randinit*_nobless functions.                     

  #########################

  INTEGER IMPORT AND EXPORT

  Rmpz_import($rop, $len, $order, $size, $endian, $nails, $bstr);

   Take a binary string ("$bstr") and convert it to a GMP
   bignum structure, treating the string as a base 256
   number. "$rop" is a Math::GMPz object holding that number.
   "$len" is the length of the string segment to be 
   converted to the GMP bignum. Normally, $len = length($bstr),
   but you can opt not to take the entire string if you like.

   Usually ($order, $size, $endian, $nails) = (1, 1, 0, 0);

   See the GMP manual for a full explanation of what these 
   variables mean.

  $bstr = Rmpz_export($order, $size, $endian, $nails, $op);

   Rmpz_export() is simply the reverse of Rmpz_import().
   It returns a base 256 string representation of the  
   number held by the Math::GMPz object, "$op".

  ###############################

  MISCELLANEOUS INTEGER FUNCTIONS

  $bool = Rmpz_fits_ulong_p($op); 
  $bool = Rmpz_fits_slong_p($op); 
  $bool = Rmpz_fits_uint_p($op); 
  $bool = Rmpz_fits_sint_p($op);
  $bool = Rmpz_fits_ushort_p($op); 
  $bool = Rmpz_fits_sshort_p($op);
   Return non-zero iff the value of $op fits an `unsigned long int',
   `signed long int', `unsigned int', `signed int', `unsigned short
   int', or `signed short int', respectively. Otherwise, return zero.

  $bool = Rmpz_odd_p($op); 
  $bool = Rmpz_even_p($op);
   Determine whether $op is odd or even, respectively.
   Return non-zero if yes, zero if no.

  $ui = Rmpz_size($op); 
   Return the size of $op measured in number of limbs.
   If $op is zero, the returned value will be zero.

  $ui = Rmpz_sizeinbase($op, $base);
   Return the size of $op measured in number of digits in base
   $base. The base may vary from 2 to 62.  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.

  ####################

  OPERATOR OVERLOADING

   Overloading works with numbers, strings, Math::GMPz objects
   and, to a limited extent, Math::MPFR objects (iff version 3.13
   or later of Math::MPFR has been installed).

  The following operators are overloaded:
   + - * / %
   += -= *= /= %=
   << >> <<= >>=
   & | ^ ~
   &= |= ^= 
   < <= > >= == != <=>
   ! abs

   Division uses 'tdiv' (see 'Integer Division', above).
   Check that '~', '%', and '%=' are working as you expect
   (especially in relation to negative values).

   Atempting to use the overloaded operators with objects that
   have been blessed into some package other than 'Math::GMPz'
   or 'Math::MPFR' (limited applications) will not work.
   Math::MPFR objects can be used only with '+', '-', '*', '/'
   and '**' operators, and will work only if Math::MPFR is at
   version 3.13 or later - in which case the operation will
   return a Math::MPFR object.

   In those situations where the overload subroutine operates on 2
   perl variables, then obviously one of those perl variables is
   a Math::GMPz object. To determine the value of the other variable
   the subroutine works through the following steps (in order),
   using the first value it finds, or croaking if it gets
   to step 6:

   1. If the variable is an unsigned long then that value is used.
      The variable is considered to be an unsigned long if 
      (perl 5.8) the UOK flag is set or if (perl 5.6) SvIsUV() 
      returns true.

   2. If the variable is a signed long int, then that value is used.
      The variable is considered to be a signed long int if the
      IOK flag is set. (In the case of perls built with
      -Duse64bitint, the variable is treated as a signed long long
      int if the IOK flag is set.)

   3. If the variable is a double, then that value is used. The
      variable is considered to be a double if the NOK flag is set.

   4. If the variable is a string (ie the POK flag is set) then the
      value of that string is used. Octal strings must begin with
      '0', hex strings must begin with either '0x' or '0X' - 
      otherwise the string is assumed to be decimal. If the POK 
      flag is set, but the string is not a valid base 8, 10, or 16
      number, the subroutine croaks with an appropriate error
      message.

   5. If the variable is a Math::GMPz object (or, for operators
      specified above, a Math::MPFR object) then the value of that
      object is used.

   6. If none of the above is true, then the second variable is
      deemed to be of an invalid type. The subroutine croaks with
      an appropriate error message.

   If the second operand is a 'double' (ie if the other
   operand's NOK flag is set) then it is first truncated
   to an integer value before the operation is performed.

   For example:
   my $x = Rmpz_init_set_ui(112);
   $x *= 2.9;
   print "$x"; # prints 224 

   Atempting to use the overloaded operators with objects that
   have been blessed into some package other than 'Math::GMPz'
   will not work.

  #####

  OTHER

  $GMP_version = Math::GMPz::gmp_v;
   Returns the version of the GMP library (eg 4.2.3) being used by
   Math::GMPz. The function is not exportable.  

  $GMP_cc = Math::GMPz::__GMP_CC;
  $GMP_cflags = Math::GMPz::__GMP_CFLAGS;
   If Math::GMPz has been built against gmp-4.2.3 or later,
   returns respectively the CC and CFLAGS settings that were used
   to compile the gmp library against which Math::GMPz was built.
   (Values are as specified in the gmp.h that was used to build
   Math::GMPz.)
   Returns undef if Math::GMPz has been built against an earlier
   version of the gmp library.
   (These functions are in @EXPORT_OK and are therefore exportable
   by request. They are not listed under the ":mpz" tag.)   
   

  $major = Math::GMPz::__GNU_MP_VERSION;
  $minor = Math::GMPz::__GNU_MP_VERSION_MINOR;
  $patchlevel = Math::GMPz::__GNU_MP_VERSION_PATCHLEVEL;
   Returns respectively the major, minor, and patchlevel numbers
   for the GMP library version used to build Math::GMPz. Values are
   as specified in the gmp.h that was used to build Math::GMPz.
   (These functions are in @EXPORT_OK and are therefore exportable
   by request. They are not listed under the ":mpz" tag.)  

  ################

  FORMATTED OUTPUT

  NOTE: The format specification can be found at:
  http://gmplib.org/manual/Formatted-Output-Strings.html#Formatted-Output-Strings
  However, the use of '*' to take an extra variable for width and
  precision is not allowed in this implementation. Instead, it is
  necessary to interpolate the variable into the format string - ie,
  instead of:
    Rmpz_printf("%*Zd\n", $width, $mpz);
  we need:
    Rmpz_printf("%${width}Zd\n", $mpz);

  $si = Rmpz_printf($format_string, $var);

   This function changed with the release of Math-GMPz-0.27.
   Now (unlike the GMP counterpart), it is limited to taking 2
   arguments - the format string, and the variable to be formatted.
   That is, you can format only one variable at a time.
   If there is no variable to be formatted, then the final arg
   can be omitted - a suitable dummy arg will be passed to the XS
   code for you. ie the following will work:
    Rmpz_printf("hello world\n");
   Returns the number of characters written, or -1 if an error
   occurred.  

  $si = Rmpz_fprintf($fh, $format_string, $var);

   This function (unlike the GMP counterpart) is limited to taking
   3 arguments - the filehandle, the format string, and the variable
   to be formatted. That is, you can format only one variable at a time.
   If there is no variable to be formatted, then the final arg
   can be omitted - a suitable dummy arg will be passed to the XS
   code for you. ie the following will work:
    Rmpz_printf($fh, "hello world\n");
   Returns the number of characters written, or -1 if an error
   occurred.

  $si = Rmpz_sprintf($buffer, $format_string, $var);

   This function (unlike the GMP counterpart) is limited to taking
   3 arguments - the buffer, the format string, and the variable
   to be formatted. If there is no variable to be formatted, then the
   final arg can be omitted - a suitable dummy arg will be passed to
   the XS code for you. ie the following will work:
    Rmpz_sprintf($buffer, "hello world\n");
   $buffer must be large enough to accommodate the formatted string,
   and is truncated to the length of that formatted string.
   If you prefer to have the resultant string returned (rather
   than stored in $buffer), use Rmpz_sprintf_ret instead - which will
   also leave the length of $buffer unaltered.
   Returns the number of characters written, or -1 if an error
   occurred.

  $string = Rmpz_sprintf_ret($buffer, $format_string, $var);

   As for Rmpz_sprintf, but returns the formatted string, as well as
   storing it in $buffer. $buffer needs to be large enough to 
   accommodate the formatted string. The length of $buffer will be
   unaltered.

  $si = Rmpz_snprintf($buffer, $bytes, $format_string, $var);

   Form a null-terminated string in $buffer. No more than $bytes 
   bytes will be written. To get the full output, $bytes must be
   enough for the string and null-terminator. $buffer must be large
   enough to accommodate the string and null-terminator, and is
   truncated to the length of that string (and null-terminator).
   The return value is the total number of characters which ought
   to have been produced, excluding the terminating null.
   If $si >= $bytes then the actual output has been truncated to
   the first $bytes-1 characters, and a null appended.
   This function (unlike the GMP counterpart) is limited to taking
   4 arguments - the buffer, the maximum number of bytes to be
   returned, the format string, and the variable to be formatted.
   If there is no variable to be formatted, then the final arg can
   be omitted - a suitable dummy arg will be passed to the XS code
   for you. ie the following will work:
    Rmpz_snprintf($buffer, 12, "hello world");
   If you prefer to have the resultant string returned (rather
   than stored in $buffer), use Rmpz_snprintf_ret instead - which will
   also leave the length of $buffer unaltered.

  $string = Rmpz_snprintf_ret($buffer, $bytes, $format_string, $var);

   As for Rmpz_snprintf, but returns the formatted string, as well as
   storing it in $buffer. $buffer needs to be large enough to 
   accommodate the formatted string. The length of $buffer will be
   unaltered. The length of $string (as reported by perl's length
   function) will be no greater than $bytes.

  ###################
   

BUGS

You can get segfaults if you pass the wrong type of
argument to the functions - so if you get a segfault, the
first thing to do is to check that the argument types 
you have supplied are appropriate.

LICENSE

This program is free software; you may redistribute it and/or 
modify it under the same terms as Perl itself.
Copyright 2006-20011, 2013 Sisyphus

AUTHOR

Sisyphus <sisyphus at(@) cpan dot (.) org>