bitwise and misbehaving with & 0xffffff00

Bug #7755	bitwise and misbehaving with & 0xffffff00
Submitted:	2000-11-10 22:29 UTC	Modified:	2001-05-13 05:33 UTC
From:	roland at astrofoto dot org	Assigned:
Status:	Closed	Package:	Math related
PHP Version:	4.0.3pl1	OS:	Linux, RedHat 7.0
Private report:	No	CVE-ID:	None

[2000-11-10 22:29 UTC] roland at astrofoto dot org

I have the following snippet of code

$w = ip2long("192.168.2.35");
$x = $w & 0xffffff00;
$y = $w & (0xffffff << 8);
$z = ip2long("192.168.2.0");
printf ("w = %s<br>", dechex($w));
printf ("x = %s<br>", dechex($x));
printf ("y = %s<br>", dechex($y));
printf ("z = %s<br>", dechex($z));

which outputs this:

w = c0a80223
x = 80000000
y = c0a80200
z = c0a80200

I can't come up with any reason why $x should be set as it is....

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[2000-11-14 12:04 UTC] stas@php.net

Please try latest CVS version (also available from
snaps.php.net) and report if it works better.

[2000-11-23 07:41 UTC] stas@php.net

Still not working, possibly won't for some time - since PHP
numbers are 32-bits signed, so they don't work well as
32-bit unsigned.

[2000-12-12 05:56 UTC] stas@php.net

I suspend this bug since PHP has no good solution for it in
the foreseeable future. Please use GMP functions for this.