CODEWITHSUNDEEP
php64-bitinteger
nonopolarity
nonopolarity

Reputation: 151036

How can I have a 64-bit integer in PHP?

How can I have a 64-bit integer in PHP?

It seems like it is not by a config file, but rather it might be a compile-time option, and it depends on the platform.

Upvotes: 64

Views: 79091

Answers (5)

Anatol Belski
Anatol Belski

Reputation: 690

Now you should get PHP 7 - fully consistent 64-bit support. Not only integers, but also all the fstat, I/O, etc. PHP 7 on Windows is true 64-bit.

Upvotes: 4

tmont
tmont

Reputation: 2620

UPDATE: It does now (tested on AMD quad core, Windows 8.1).

Note that PHP on Windows does not support 64-bit integers at all, even if both the hardware and PHP are 64-bit. See this link for details:

On Windows x86_64, PHP_INT_MAX is 2147483647. This is because in the underlying C code, a long is 32 bit.

However, Linux on x86_64 uses a 64-bit long, so PHP_INT_MAX is going to be 9223372036854775807.

Upvotes: 54

Milen A. Radev
Milen A. Radev

Reputation: 62593

Maybe you could use either the GMP or BCMath extension.

Upvotes: 9

scotts
scotts

Reputation: 4097

Native 64-bit integers require 64-bit hardware AND the 64-bit version of PHP.

On 32-bit hardware:

$ php -r 'echo PHP_INT_MAX;'
2147483647

On 64-bit hardware:

$ php -r 'echo PHP_INT_MAX;'
9223372036854775807

Upvotes: 86

Josh Curren
Josh Curren

Reputation: 10226

PHP int size is platform-dependent. There is a function called unpack() which essentially allows to convert different types of data from binary strings to PHP variables. It seems to be the only way to store as 64 bit is to store it as a string.

I found the following code at: http://www.mysqlperformanceblog.com/2007/03/27/integers-in-php-running-with-scissors-and-portability/

/// portably build 64bit id from 32bit hi and lo parts
function _Make64 ( $hi, $lo )
{

        // on x64, we can just use int
        if ( ((int)4294967296)!=0 )
            return (((int)$hi)<<32) + ((int)$lo);

        // workaround signed/unsigned braindamage on x32
        $hi = sprintf ( "%u", $hi );
        $lo = sprintf ( "%u", $lo );

        // use GMP or bcmath if possible
        if ( function_exists("gmp_mul") )
            return gmp_strval ( gmp_add ( gmp_mul ( $hi, "4294967296" ), $lo ) );

        if ( function_exists("bcmul") )
            return bcadd ( bcmul ( $hi, "4294967296" ), $lo );

        // compute everything manually
        $a = substr ( $hi, 0, -5 );
        $b = substr ( $hi, -5 );
        $ac = $a*42949; // hope that float precision is enough
        $bd = $b*67296;
        $adbc = $a*67296+$b*42949;
        $r4 = substr ( $bd, -5 ) +  + substr ( $lo, -5 );
        $r3 = substr ( $bd, 0, -5 ) + substr ( $adbc, -5 ) + substr ( $lo, 0, -5 );
        $r2 = substr ( $adbc, 0, -5 ) + substr ( $ac, -5 );
        $r1 = substr ( $ac, 0, -5 );
        while ( $r4>100000 ) { $r4-=100000; $r3++; }
        while ( $r3>100000 ) { $r3-=100000; $r2++; }
        while ( $r2>100000 ) { $r2-=100000; $r1++; }

        $r = sprintf ( "%d%05d%05d%05d", $r1, $r2, $r3, $r4 );
        $l = strlen($r);
        $i = 0;
        while ( $r[$i]=="0" && $i<$l-1 )
            $i++;
        return substr ( $r, $i );         
    }

    list(,$a) = unpack ( "N", "\xff\xff\xff\xff" );
    list(,$b) = unpack ( "N", "\xff\xff\xff\xff" );
    $q = _Make64($a,$b);
    var_dump($q);

Upvotes: 9

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