NAME

Math::Int64 - Manipulate 64 bits integers in Perl

SYNOPSIS

  use Math::Int64 qw(int64);

  my $i = int64(1);
  my $j = $i << 40;
  my $k = int64("12345678901234567890");
  print($i + $j * 1000000);

DESCRIPTION

This module adds support for 64 bit integers, signed and unsigned, to Perl.

Exportable functions

int64()

int64($value)

Creates a new int64 value and initializes it to $value, where $value can be a Perl number or a string containing a number.

For instance:

  $i = int64(34);
  $j = int64("-123454321234543212345");

  $k = int64(1234567698478483938988988); # wrong!!!
                                         #  the unquoted number would
                                         #  be converted first to a
                                         #  real number causing it to
                                         #  loose some precision.

Once the int64 number is created it can be manipulated as any other Perl value supporting all the standard operations (addition, negation, multiplication, postincrement, etc.).

net_to_int64($str)

Converts an 8 bytes string containing an int64 in network order to the internal representation used by this module.

int64_to_net($int64)

Returns an 8 bytes string with the representation of the int64 value in network order.

native_to_int64($str)

int64_to_native($int64)

similar to net_to_int64 and int64_to_net, but using the native CPU order.

int64_to_number($int64)

returns the optimum representation of the int64 value using Perl internal types (IV, UV or NV). Precision may be lost.

For instance:

  for my $l (10, 20, 30, 40, 50, 60) {
    my $i = int64(1) << $l;
    my $n = int64_to_number($i);
    print "int64:$i => perl:$n\n";
  }

uint64

uint64_to_number

net_to_uint64

uint64_to_net

native_to_uint64

uint64_to_native

These functions are similar to their int64 counterparts, but manipulate 64 bit unsigned integers.

Fallback to native 64bit support if available

If the tag :native_if_available is added to the import list and the version of perl used has native support for 64bit integers, the functions exported by the module to create 64bit intgers will return regular perl scalars.

Usage example:

  use Math::Int64 qw( :native_if_available int64 );

This feature is not enabled by default because the semantics for perl scalars and for 64 bit integers as implemented in this module are not identical. Perl is prone to coerze integers into floats while this module keeps then always as 64bit integers. Specifically, the division operation and overflows are the most problematic cases.

Besides that, in most situations it is safe to use the native fallback.

BUGS AND SUPPORT

The fallback to native 64bit integers feature is experimental.

This module requires int64 support from the C compiler.

For bug reports, feature requests or just help using this module, use the RT system at http://rt.cpan.org or send my and email or both!

The source code of this module is hosted at GitHub: http://github.com/salva/p5-Math-Int64.

SEE ALSO

Other modules that allow Perl to support larger integers or numbers are Math::BigInt, Math::BigRat and Math::Big, Math::BigInt::BitVect, Math::BigInt::Pari and Math::BigInt::GMP.

COPYRIGHT AND LICENSE

Copyright © 2007, 2009, 2011 by Salvador Fandiño (sfandino@yahoo.com)

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.8 or, at your option, any later version of Perl 5 you may have available.