From owner-freebsd-questions  Fri May 19  3: 1:57 2000
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Date: Fri, 19 May 2000 12:01:35 +0200
From: Hans Weber <weber@mt.luth.se>
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Subject: gcc_debian_linux_code_on_freebsd
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Dear Sirs

I have a rather odd problem with gcc. (version 2.95.1)

Code compiled on a Debian linux machine with gcc (2.95) is 20 %
faster on my freebsd machine compared to if I compile on my
freebsd machine and then run it on my freebsd machine. I have
linux compat enabled.

I would like to get at least equally fast code from gcc freebsd as I get
from
gcc on debian.

     The program is a molecular dynamics program doing lots of floats.

      The times are typically:
       compiled and run on freebsd   36 seconds
       compiled on debian and run on freebsd 30 seconds

I have tried some tricks with setenv  and a variable with
lots of characters this can result in (I got this from tip from a
friend)

        compiled and run on freebsd becoming 34.5 seconds

Compile is done with on both debian and freebsd.
gcc -O -o langevin langevin.c -lm

and these are the includes in my program.
# include <stdio.h>
# include <math.h>
# include <stdlib.h>
# include <limits.h>

I have just added smp and taken out i386 and i486 from build
fysik3 102> cat motd
FreeBSD 4.0-RELEASE (SMPKERNEL) #1: Tue May  9 13:24:58 CEST 2000

Welcome to FreeBSD!

Best regards
HAns Weber




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