* [Bug libc/5807] strlen() not effective
2008-02-29 0:43 [Bug libc/5807] New: strlen() not effective egmont at gmail dot com
@ 2008-03-02 3:30 ` carlos at codesourcery dot com
2008-03-02 3:34 ` carlos at codesourcery dot com
` (5 subsequent siblings)
6 siblings, 0 replies; 10+ messages in thread
From: carlos at codesourcery dot com @ 2008-03-02 3:30 UTC (permalink / raw)
To: glibc-bugs
------- Additional Comments From carlos at codesourcery dot com 2008-03-02 03:29 -------
The math is wrong.
It looks glibc has a broken version of Alan Mycroft's HAKMEMC postings.
See: http://www.cl.cam.ac.uk/~am21/progtricks.html
The solution is "((x - 0x01010101) & ~x & 0x80808080)", but the "& ~x" is
missing from the glibc version.
The "#if 0" was added Tue Jan 21 03:39:54 1992 UTC (16 years, 1 month ago) by
roland, and the patch looked like this:
http://sources.redhat.com/cgi-bin/cvsweb.cgi/libc/sysdeps/generic/Attic/strlen.c.diff?r1=1.1&r2=1.2&cvsroot=glibc
I can reproduce this on cvs head. The generic strlen function is horribly
inefficient.
Roland can you comment on this?
What's the legal status of using that algorithm?
--
What |Removed |Added
----------------------------------------------------------------------------
AssignedTo|drepper at redhat dot com |roland at redhat dot com
Status|NEW |ASSIGNED
http://sourceware.org/bugzilla/show_bug.cgi?id=5807
------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug libc/5807] strlen() not effective
2008-02-29 0:43 [Bug libc/5807] New: strlen() not effective egmont at gmail dot com
2008-03-02 3:30 ` [Bug libc/5807] " carlos at codesourcery dot com
@ 2008-03-02 3:34 ` carlos at codesourcery dot com
2008-03-02 15:12 ` carlos at codesourcery dot com
` (4 subsequent siblings)
6 siblings, 0 replies; 10+ messages in thread
From: carlos at codesourcery dot com @ 2008-03-02 3:34 UTC (permalink / raw)
To: glibc-bugs
--
What |Removed |Added
----------------------------------------------------------------------------
OtherBugsDependingO| |5806
nThis| |
http://sourceware.org/bugzilla/show_bug.cgi?id=5807
------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug libc/5807] strlen() not effective
2008-02-29 0:43 [Bug libc/5807] New: strlen() not effective egmont at gmail dot com
2008-03-02 3:30 ` [Bug libc/5807] " carlos at codesourcery dot com
2008-03-02 3:34 ` carlos at codesourcery dot com
@ 2008-03-02 15:12 ` carlos at codesourcery dot com
2008-04-17 19:56 ` stas dot yakovlev at gmail dot com
` (3 subsequent siblings)
6 siblings, 0 replies; 10+ messages in thread
From: carlos at codesourcery dot com @ 2008-03-02 15:12 UTC (permalink / raw)
To: glibc-bugs
------- Additional Comments From carlos at codesourcery dot com 2008-03-02 15:12 -------
Note: All the string/* operations should use the corrected algorithm, and the
old comments should be removed.
--
http://sourceware.org/bugzilla/show_bug.cgi?id=5807
------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug libc/5807] strlen() not effective
2008-02-29 0:43 [Bug libc/5807] New: strlen() not effective egmont at gmail dot com
` (2 preceding siblings ...)
2008-03-02 15:12 ` carlos at codesourcery dot com
@ 2008-04-17 19:56 ` stas dot yakovlev at gmail dot com
2008-04-22 13:04 ` carlos at codesourcery dot com
` (2 subsequent siblings)
6 siblings, 0 replies; 10+ messages in thread
From: stas dot yakovlev at gmail dot com @ 2008-04-17 19:56 UTC (permalink / raw)
To: glibc-bugs
------- Additional Comments From stas dot yakovlev at gmail dot com 2008-04-17 19:55 -------
Created an attachment (id=2703)
--> (http://sourceware.org/bugzilla/attachment.cgi?id=2703&action=view)
Alan Mycroft's hack for strlen()
Hi All.
I know that you only accept patches if
contributor signs an assignment.
But do you accept small bug fix without an
assignment, like that I attached to the bug ?
This is a fix for strlen() only
(I can do it for all other functions if you can accept
patches like this). It deletes old comments,
and adds Alan Mycroft's hack.
Stas.
--
http://sourceware.org/bugzilla/show_bug.cgi?id=5807
------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug libc/5807] strlen() not effective
2008-02-29 0:43 [Bug libc/5807] New: strlen() not effective egmont at gmail dot com
` (3 preceding siblings ...)
2008-04-17 19:56 ` stas dot yakovlev at gmail dot com
@ 2008-04-22 13:04 ` carlos at codesourcery dot com
2008-04-23 15:49 ` stas dot yakovlev at gmail dot com
2009-03-15 8:50 ` drepper at redhat dot com
6 siblings, 0 replies; 10+ messages in thread
From: carlos at codesourcery dot com @ 2008-04-22 13:04 UTC (permalink / raw)
To: glibc-bugs
------- Additional Comments From carlos at codesourcery dot com 2008-04-22 13:03 -------
Stas,
The changes are more than trivial, you would need a copyright assignment for
glibc on file with the FSF.
--
http://sourceware.org/bugzilla/show_bug.cgi?id=5807
------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug libc/5807] strlen() not effective
2008-02-29 0:43 [Bug libc/5807] New: strlen() not effective egmont at gmail dot com
` (4 preceding siblings ...)
2008-04-22 13:04 ` carlos at codesourcery dot com
@ 2008-04-23 15:49 ` stas dot yakovlev at gmail dot com
2009-03-15 8:50 ` drepper at redhat dot com
6 siblings, 0 replies; 10+ messages in thread
From: stas dot yakovlev at gmail dot com @ 2008-04-23 15:49 UTC (permalink / raw)
To: glibc-bugs
------- Additional Comments From stas dot yakovlev at gmail dot com 2008-04-23 15:48 -------
Carlos,
Thanks for reply.
--
http://sourceware.org/bugzilla/show_bug.cgi?id=5807
------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug libc/5807] strlen() not effective
2008-02-29 0:43 [Bug libc/5807] New: strlen() not effective egmont at gmail dot com
` (5 preceding siblings ...)
2008-04-23 15:49 ` stas dot yakovlev at gmail dot com
@ 2009-03-15 8:50 ` drepper at redhat dot com
6 siblings, 0 replies; 10+ messages in thread
From: drepper at redhat dot com @ 2009-03-15 8:50 UTC (permalink / raw)
To: glibc-bugs
------- Additional Comments From drepper at redhat dot com 2009-03-15 08:50 -------
I changed the code. Although noboy seems to use it.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution| |FIXED
http://sourceware.org/bugzilla/show_bug.cgi?id=5807
------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.
^ permalink raw reply [flat|nested] 10+ messages in thread