(PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)
gmp_com — Calculates one's complement
num
A GMP object, an int,
or a string that can be interpreted as a number following the same logic
as if the string was used in gmp_init() with automatic
base detection (i.e. when base is equal to 0).
Returns the one's complement of num, as a GMP number.
Example #1 gmp_com() example
<?php
$com = gmp_com("1234");
echo gmp_strval($com) . "\n";
?>The above example will output:
-1235
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)