From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from web23412.mail.ird.yahoo.com (web23412.mail.ird.yahoo.com [217.146.189.97]) by ozlabs.org (Postfix) with SMTP id 906BBDDDCA for ; Mon, 19 Feb 2007 19:51:45 +1100 (EST) Date: Mon, 19 Feb 2007 09:45:04 +0100 (CET) From: Patrice Bouchand Subject: mcpu options for AMCC440 with fpu To: linuxppc-embedded@ozlabs.org MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-1467494991-1171874704=:55072" Message-ID: <600461.55072.qm@web23412.mail.ird.yahoo.com> List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --0-1467494991-1171874704=:55072 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Hello, I was searching for the best mcpu option for amcc440, compiling and running a small program you can find here: http://magnux.free.fr/gcc/mandelbrot.c. My distro is a ppc fedora core 6, and results are obviously the same using DENX4.0. -------------------- -bash-3.00# gcc -O2 ./mandelbrot.c -o ./mandelbrot && time ./mandelbrot && rm -f ./mandelbrot real 1m15.059s user 1m14.996s sys 0m0.060s -bash-3.00# gcc -O2 -mcpu=440 ./mandelbrot.c -o ./mandelbrot && time ./mandelbrot && rm -f ./mandelbrot real 0m39.606s user 0m39.552s sys 0m0.028s -bash-3.00# gcc -O2 -mcpu=440fp ./mandelbrot.c -o ./mandelbrot && time ./mandelbrot && rm -f ./mandelbrot real 1m15.016s user 1m14.988s sys 0m0.024s -bash-3.00# gcc -O2 -msoft-float ./mandelbrot.c -o ./mandelbrot && time ./mandelbrot && rm -f ./mandelbrot real 0m39.577s user 0m39.544s sys 0m0.032s -------------------- * I do not explain why not using FPU gives better results ? * I did also a test with bzip2.c ( http://pag.csail.mit.edu/~smcc/projects/single-file-programs/bzip2.c ). ---------------------- -bash-3.00# gcc -O2 ./bzip2.c -o ./bzip2 && time ./bzip2 ./oggenc.c && ./bzip2 -d ./oggenc.c.bz2 && rm ./bzip2 real 0m18.478s user 0m18.216s sys 0m0.152s -bash-3.00# gcc -O2 -mcpu=440 ./bzip2.c -o ./bzip2 && time ./bzip2 ./oggenc.c && ./bzip2 -d ./oggenc.c.bz2 && rm ./bzip2 real 0m18.786s user 0m18.544s sys 0m0.128s -bash-3.00# gcc -O2 -mcpu=440fp ./bzip2.c -o ./bzip2 && time ./bzip2 ./oggenc.c && ./bzip2 -d ./oggenc.c.bz2 && rm ./bzip2 real 0m18.811s user 0m18.548s sys 0m0.144s -bash-3.00# gcc -O2 -mcpu=G3 ./bzip2.c -o ./bzip2 && time ./bzip2 ./oggenc.c && ./bzip2 -d ./oggenc.c.bz2 && rm ./bzip2 real 0m18.871s user 0m18.644s sys 0m0.104s ---------------------- * mcpu option seems to not have any effect ? * My third test was to compile and run mplayer. - With default options (no mcpu specified), my test mpeg was smooth. - With mcpu=440fp, my test mpeg was not smooth. Can anybody bring me some lights about the right gcc mcpu option for amcc440 ? Best regards, Patrice Bouchand --------------------------------- Découvrez une nouvelle façon d'obtenir des réponses à toutes vos questions ! Profitez des connaissances, des opinions et des expériences des internautes sur Yahoo! Questions/Réponses. --0-1467494991-1171874704=:55072 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Hello,

   I was searching for the best mcpu option for amcc440, compiling and running a small program you can find here:
http://magnux.free.fr/gcc/mandelbrot.c. My distro is a ppc fedora core 6, and results are obviously the same using DENX4.0.

--------------------
-bash-3.00# gcc -O2 ./mandelbrot.c -o ./mandelbrot && time ./mandelbrot && rm -f ./mandelbrot

real    1m15.059s
user    1m14.996s
sys     0m0.060s
-bash-3.00# gcc -O2 -mcpu=440 ./mandelbrot.c -o ./mandelbrot && time ./mandelbrot && rm -f ./mandelbrot

real    0m39.606s
user    0m39.552s
sys     0m0.028s
-bash-3.00# gcc -O2 -mcpu=440fp ./mandelbrot.c -o ./mandelbrot && time ./mandelbrot && rm -f ./mandelbrot

real    1m15.016s
user    1m14.988s
sys     0m0.024s
-bash-3.00# gcc -O2 -msoft-float ./mandelbrot.c -o ./mandelbrot && time ./mandelbrot && rm -f ./mandelbrot

real    0m39.577s
user    0m39.544s
sys     0m0.032s
--------------------

* I do not explain why not using FPU gives better results ?

* I did also a test with bzip2.c ( http://pag.csail.mit.edu/~smcc/projects/single-file-programs/bzip2.c ).

----------------------
-bash-3.00# gcc -O2 ./bzip2.c -o ./bzip2 && time ./bzip2 ./oggenc.c && ./bzip2 -d ./oggenc.c.bz2 && rm ./bzip2

real    0m18.478s
user    0m18.216s
sys     0m0.152s
-bash-3.00# gcc -O2 -mcpu=440 ./bzip2.c -o ./bzip2 && time ./bzip2 ./oggenc.c && ./bzip2 -d ./oggenc.c.bz2 && rm ./bzip2

real    0m18.786s
user    0m18.544s
sys     0m0.128s
-bash-3.00# gcc -O2 -mcpu=440fp ./bzip2.c -o ./bzip2 && time ./bzip2 ./oggenc.c && ./bzip2 -d ./oggenc.c.bz2 && rm ./bzip2

real    0m18.811s
user    0m18.548s
sys     0m0.144s
-bash-3.00# gcc -O2 -mcpu=G3 ./bzip2.c -o ./bzip2 && time ./bzip2 ./oggenc.c && ./bzip2 -d ./oggenc.c.bz2 && rm ./bzip2

real    0m18.871s
user    0m18.644s
sys     0m0.104s
----------------------

* mcpu option seems to not have any effect ?

*  My third test was to compile and run mplayer.
- With default options (no mcpu specified), my test mpeg was smooth.
- With mcpu=440fp, my test mpeg was not smooth.

 Can anybody bring me some lights about the right gcc mcpu option for amcc440 ?

Best regards,

       Patrice Bouchand

Découvrez une nouvelle façon d'obtenir des réponses à toutes vos questions ! Profitez des connaissances, des opinions et des expériences des internautes sur Yahoo! Questions/Réponses. --0-1467494991-1171874704=:55072--