[Coin-ipopt] Ipopt in amd 64bit tricks/tips

[Andreas Waechter]

Hi Rodrigo,

It depends on the default settings for your compiler, but on the Opteron 
systems I have been working on, GCC automatically compiles 64bit 
executables.  You probably don't have to do anything special to compile 
64bit code (to verify, see what the 'file' command ways for your ipopt 
executable - for me, it say something like:

ELF 64-bit LSB executable, AMD x86-64, version 1 (SYSV), for GNU/Linux 
2.4.1, dynamically linked (uses shared libs), not stripped

But the default compiler flags set by the COIN configure scripts do not 
try to find the most aggressive flags for the platform they are running 
on, and you might be able to improve performance by specifying additional 
compiler flags (using the ADD_CXXFLAGS, ADD_CFLAGS, ADD_FFLAGS, see 
https://projects.coin-or.org/BuildTools/wiki/user-configure#VariableArgumentsforconfigure),
such as -mtune and -march; see the GCC compiler documentation for 
details.

I hope this answers your questions,

Andreas

On Wed, 12 Dec 2007, [UTF-8] Rodrigo López Negrete de la Fuente wrote:

> Hi all,

I've recently compiled Ipopt in an AMD Opteron (64 bit) computer running
Ubuntu Gusty for 64 Bits without any problems. I simply used

$ ./configure
$ make && make test
$ make install

My question is: are there any combination of flags for the C++ and/or
Fortran compilers that will take full advantage of the 64 bit technology?

Any suggestions will be very welcome!


Thanks to all,
  Rodrigo

-- 
Rodrigo López Negrete de la Fuente
Email: r.lopez.negrete at gmail.com
Carnegie Mellon University
Department of Chemical Engineering
5000 Forbes Ave.
Pittsburgh, PA 15213-3890
USA