Code speed

[Jan Kroken <jankr at ifi dot uio dot no>]

To test gcc 3.0's performance, I tried to compile gawk-3.1.0 with
different versions of gcc, and different flags, on a Pentium III
computer (linux-2.2.12,glibc-2.1.2).

The versions of gcc I have are gcc-2.95.2 (probably compiled with
gcc-2.95 or 2.95.1, I don't remember), and the gcc snapshot from
2001-06-04 (3.0), compiled withy gcc-2.95.2. All test runs of gawk are
run several times to avoid bad/good luck. In the list below, I have
included "representative" test runs.

I then tested the speed of the compiled gawk by runnign a simple
script on a log file of about 1.2 mb, with the time command.

in all cases, awk is compiled with
./configure --prefix=... ;make;make install


Here are the results:


CC=gcc-2.95.2, CFLAGS=

% time awk -f test.awk numberofproducts.log
110587
awk -f test.awk numberofproducts.log  0.62s user 0.03s system 101% cpu 0.640 total



CC=gcc-2.95.2, CFLAGS=-march=i686

% time /usr/test/march/bin/awk -f test.awk numberofproducts.log
110587
/usr/test/march/bin/awk -f test.awk numberofproducts.log  1.06s user 0.02s system 97% cpu 1.105 total



CC=gcc-2.95.2, CFLAGS=-march=i686 -O3

% time /usr/test/march_o3/bin/awk -f test.awk numberofproducts.log
110587
/usr/test/march_o3/bin/awk -f test.awk numberofproducts.log  0.67s user 0.04s system 106% cpu 0.666 total



CC=gcc-3.0, CFLAGS=

% time /usr/test/gcc3/bin/awk -f test.awk numberofproducts.log
110587
/usr/test/gcc3/bin/awk -f test.awk numberofproducts.log  0.90s user 0.02s system 106% cpu 0.867 total



CC=gcc-3.0, CFLAGS="-march=i686 -O3"

% time /usr/test/gcc3_march_o3/bin/awk -f test.awk numberofproducts.log
110587
/usr/test/gcc3_march_o3/bin/awk -f test.awk numberofproducts.log  0.79s user 0.04s system 108% cpu 0.765 total




AWK script:

BEGIN { N=0 ; }
/23/ { N=N+$3 ; }
END { print N ; }

Detailed system specification

% rpm -qa | grep glibc
glibc-2.1.2-11
glibc-devel-2.1.2-11

% more /proc/version 
Linux version 2.2.12-20 (root@porky.devel.redhat.com) (gcc version egcs-2.91.66 
19990314/Linux (egcs-1.1.2 release)) #1 Mon Sep 27 10:40:35 EDT 1999

% more /proc/cpuinfo 
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 7
model name      : Pentium III (Katmai)
stepping        : 3
cpu MHz         : 599.938468
cache size      : 512 KB
fdiv_bug        : no
hlt_bug         : no
sep_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 3
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov pat p
se36 psn mmx osfxsr kni
bogomips        : 598.02


-- 
                                                     -jk