Re: [Getfem-users] Compilation options

[Torquil Macdonald Sørensen]

On 05/06/13 22:05, Michel Dupront wrote:

hello,

I installed the getfem++ dev library on my ubuntu 12.04 platform
using synaptic.
I supposed that the c++ code has been compiled with optimization
options.
How can I know what options have been used ?
Thanks in advance.

Here is how I think it can be done:

First, go to this Ubuntu page for getfem++:

https://launchpad.net/ubuntu/+source/getfem++/

Then, near the bottom you'll find a link to the 12.04 version (called Lucid). Click on the little triangle next to the link "4.0.0-3" within that section. Then click on the link called "amd64" that has just emerged. That sends you to a page with a link called "buildlog".

Within that file I search for e.g. for "./configure" to find the detailed configure command that was run on the Ubuntu build server. It was:

./configure --build x86_64-linux-gnu --prefix=/usr --enable-boost --enable-shared --with-pic --enable-python --disable-matlab --disable-superlu CFLAGS="-g -O2"

So you can see that these options were used for the configure script, and the last item tells us that "-g -O2" were used as options for GCC. However, there is something slightly strange there, because if you inspect the g++ commands in detail further down in the buildlog, it shows that -O3 is used as well. E.g.:

g++ -DHAVE_CONFIG_H -I. -I.. -I../src -I../src -I.. -DGMM_USES_BLAS -g -O2 -O3 -Wall -W -fmessage-length=0 -ftemplate-depth-40 -pedantic -Wshadow -Wpointer-arith -Wcast-qual -Wwrite-strings -Wconversion -Wredundant-decls -Wno-long-long -MT bgeot_poly.lo -MD -MP -MF .deps/bgeot_poly.Tpo -c bgeot_poly.cc  -fPIC -DPIC -o .libs/bgeot_poly.o

All g++ invocations seem to use "-g -O2 -O3".

Hope this helps.

Best regards
Torquil Sørensen