gmp_cmp
If you're using one's compliment (bitwise NOT) to flip all $a's bits, don't forget that you need to use a mask to specify how many bits you expect in your result:
<?php gmp_and(gmp_com('1234'), '2047') ?>
>> 813 // 01100101101 in binary
I chose 2047 because 1234 is an 11-bit binary number and 2047 is the maximum an 11-bit register can hold:
11111111111 (2047)
10011010010 (1234)
01100101101 (813)
gmp_com
(PHP 4 >= 4.0.4, PHP 5)
gmp_com — Calculates one's complement
Description
resource gmp_com
( resource
$a
)
Returns the one's complement of a.
Parameters
-
a -
It can be either a GMP number resource, or a numeric string given that it is possible to convert the latter to a number.
Return Values
Returns the one's complement of a, as a GMP number.
Examples
Example #1 gmp_com() example
<?php
$com = gmp_com("1234");
echo gmp_strval($com) . "\n";
?>
The above example will output:
-1235
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User Contributed Notes
gmp_com - [1 notes]
xo at jdbartlett dot com ¶
3 years ago