Dave Korn wrote:
Agner Fog wrote on 24 July 2008 09:04:
Tim Prince wrote:
>you identify the library you tested only as "ubuntu g++ 4.2.3."
Where can I see the libc version?
Use whichever package manager ubuntu provides to check the version of the
glibc package. Here's an example fron a centos (using rpm):
On most Linux systems, in addition of using the package manager, the
libc.so file is executable, and when executed, shows info, so on my
Debian/Sid/AMD64 I'm getting
% /lib/libc.so.6
GNU C Library stable release version 2.7, by Roland McGrath et al.
Copyright (C) 2007 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
Compiled by GNU CC version 4.3.1 20080523 (prerelease).
Compiled on a Linux >>2.6.25-2-amd64<< system on 2008-06-02.
Available extensions:
crypt add-on version 2.1 by Michael Glad and others
GNU Libidn by Simon Josefsson
Native POSIX Threads Library by Ulrich Drepper et al
BIND-8.2.3-T5B
For bug reporting instructions, please see:
<http://www.gnu.org/software/libc/bugs.html>.
Of course, on Ubuntu & Debian, you can query the package system
% dpkg -l libc6
Desired=Unknown/Install/Remove/Purge/Hold
|
Status=Not/Inst/Cfg-files/Unpacked/Failed-cfg/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err:
uppercase=bad)
||/ Name Version Description
+++-==============-==============-============================================
ii libc6 2.7-12 GNU C Library: Shared libraries
Regarding the original thread (performance of GCC & standard functions)
it should be stressed that gcc would probably compile them better if
passed machine specific flags.
At last, at the recent (july 2008) GCC summit, someone (sorry I forgot
who, probably someone from SuSE) proposed in a BOFS to have architecture
and machine specific hand-tuned (or even hand-written assembly) low
level libraries for such basic things as memset etc..
Thanks for reading
--
Basile STARYNKEVITCH http://starynkevitch.net/Basile/
email: basile<at>starynkevitch<dot>net mobile: +33 6 8501 2359
8, rue de la Faiencerie, 92340 Bourg La Reine, France
*** opinions {are only mines, sont seulement les miennes} ***
