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Re: [Help-gsl] Speed problem
- From: Dirk Eddelbuettel <edd at debian dot org>
- To: Jochen Küpper <jochen at fhi-berlin dot mpg dot de>
- Cc: gsl-discuss at sources dot redhat dot com
- Date: Wed, 25 May 2005 19:37:54 -0500
- Subject: Re: [Help-gsl] Speed problem
- References: <42944CB0.8030106@paolo.zavarise.name><m3d5rfm2rc.fsf@doze.jochen-kuepper.de>
On 25 May 2005 at 23:09, Jochen Küpper wrote:
| Paolo Zavarise <physics@paolo.zavarise.name> writes:
|
| > GSL 1.6 compiled by myself is five/ten time slower than GSL included in
| > ubuntu (1.5.90, same one I think). I've compiled with configure/make, no
| > options, and installed in a non-default dir.
Is that a recompiled Ubuntu version, or the "straight" Debian package I
maintain? In that case, the flags we use are
DEB_BUILD_GNU_TYPE = $(shell dpkg-architecture -qDEB_BUILD_GNU_TYPE)
DEB_HOST_GNU_TYPE = $(shell dpkg-architecture -qDEB_HOST_GNU_TYPE)
ifneq ($(DEB_BUILD_GNU_TYPE),$(DEB_HOST_GNU_TYPE))
CONFARGS = --host=$(DEB_HOST_GNU_TYPE)
endif
[...]
compilerflags = "-O2 -D_REENTRANT"
[...]
./configure --prefix=/usr \
--enable-shared \
--enable-static \
--with-gnu-ld \
$(CONFARGS)
[...]
$(MAKE) CFLAGS=$(compilerflags)
i.e. it is basically just doing a regular -O2. (-D_REENTRANT is mandated by
Debian Policy as it should make multi-threaded apps behave better, as I
recall, as has no performance implications.)
| Did you compile with optimizations? If not, try setting CFLAGS, i.e.
| ,----
| | export CFLAGS="-g -O2 -pipe -Wall"
| `----
| Best would be to look at the GCC manual...
Also, what are you using as the benchmark, and how are you comparing this?
On a dual-boot system where you may have Atlas under Ubuntu but not on the
second system? Just a thought.
Dirk
--
Statistics: The (futile) attempt to offer certainty about uncertainty.
-- Roger Koenker, 'Dictionary of Received Ideas of Statistics'