Req #45688 [Com]: 64bit unsigned integers, or provide a workaround.
| From: | ajf@php.net | Date: | Fri, 09 Jan 2015 01:23:18 +0000 |
| Subject: | Req #45688 [Com]: 64bit unsigned integers, or provide a workaround. | ||
| References: | 1 | Groups: | php.bugs |
| Request: | Send a blank email to php-bugs+get-189816@lists.php.net to get a copy of this message | ||
Edit report at https://bugs.php.net/bug.php?id=45688&edit=1
ID: 45688
Comment by: ajf@php.net
Reported by: andy at haveland dot com
Summary: 64bit unsigned integers, or provide a workaround.
Status: Open
Type: Feature/Change Request
Package: Feature/Change Request
Operating System: Linux 2.6.25.11-97.fc9.x86_64
PHP Version: 5.2.6
Block user comment: N
Private report: N
New Comment:
This RFC would deal with this, indirectly: http://wiki.php.net/rfc/bigint
Previous Comments:
------------------------------------------------------------------------
[2008-08-02 14:14:23] andy at haveland dot com
Description:
------------
I've had a look at some bogus bug reports on unsigned integers and rounding precision, and
understand the issues and reasons but want to add my voice to request better integer support.
bcmaths is overkill for simple bit operations.
I'm trying to use php to process thousands of random 64-bit ids supplied in decimal and half
have the high bit set.
As they are keys in a database mapped to hierarchical directories, accuracy, speed and repeatability
is a big issue. Renaming to 63 bit ids is not an option!
You may consider this as a bogus request, but I think lack of unsigned support is a serious issue.
Any bit operations that touch the high bit turn to mush if set, and limits php to 31 or 63 bit
program!
If perl can deal correctly with this, then shouldn't php be able to as well?
Andy.
Reproduce code:
---------------
$id = 11791849344837931437;
print "\$id = $id\n";
printf("\$id = 0x%x (%20u)\n", $id, $id);
f($id);
f(($id & 0xf000000000000000) >> 60);
$idhi= $id >> 32;
$idlo= $id & 0xffffffff;
f2($idhi, $idlo);
function f($id) {
printf ("f(\$id) = 0x%x (%20u)\n", $id, $id);
}
function f2($idhi, $idlo) {
printf ("\$idhi = 0x%x (%20u)\n", $idhi, $idhi);
printf ("\$idlo = 0x%x (%20u)\n", $idlo, $idlo);
}
(Perl code is practically identical, apart from s/function/sub/ and param passing)
Expected result:
----------------
# perl showbug.pl
$id = 11791849344837931437
$id = 0xa3a51080d3fcd1ad (11791849344837931437)
f($id) = 0xa3a51080d3fcd1ad (11791849344837931437)
f($id) = 0xa ( 10)
$idhi = 0xa3a51080 ( 2745503872)
$idlo = 0xd3fcd1ad ( 3556561325)
Actual result:
--------------
# php showbug.php
$id = 1.1791849344838E+19
$id = 0xa3a51080d3fcd000 (11791849344837931008)
f($id) = 0xa3a51080d3fcd000 (11791849344837931008)
f($id) = 0xfffffffffffffffa (18446744073709551610)
$idhi = 0xffffffffa3a51080 (18446744072160088192)
$idlo = 0xd3fcd000 ( 3556560896)
------------------------------------------------------------------------
--
Edit this bug report at https://bugs.php.net/bug.php?id=45688&edit=1