Hello, > Here's an example program that you can test and time yourself. > > On my Core 2, I get > > [EMAIL PROTECTED] ~]$ gcc -DCMOV -Wall -O2 t.c > [EMAIL PROTECTED] ~]$ time ./a.out > 600000000 > > real 0m0.194s > user 0m0.192s > sys 0m0.000s > > [EMAIL PROTECTED] ~]$ gcc -Wall -O2 t.c > [EMAIL PROTECTED] ~]$ time ./a.out > 600000000 > > real 0m0.167s > user 0m0.168s > sys 0m0.000s
Test was done on my laptop with gcc 4.1.1 and CPU:
processor : 0
vendor_id : GenuineIntel
cpu family : 15
model : 2
model name : Intel(R) Pentium(R) 4 CPU 2.40GHz
stepping : 9
cpu MHz : 2392.349
cache size : 512 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov pat
pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe cid xtpr
bogomips : 4786.36
clflush size : 64
I wrote a simple script that run each version of your code 100
times measuring the execution time. Then some simple gnuplot
magic was applied. The result is attached (png file).
- cmovne was faster with almost stable execution time (~171ms)
- je-mov was slower and execution time varies
Interpretation is up to you ;-)
--
Regards,
Mariusz Kozlowski
benchmark.png
Description: PNG image
