# [Bf-committers] sqrt code snippet

**Janek Kozicki
**
bf-committers@blender.org

*Sun, 30 May 2004 16:28:49 +0200*

I wrote this piece of code to benchmark speed of sqrt(). I did it in
three minutes, so don't flame me for... umm? bad code ;)
Uncomment respective lines then compile.
#include <math.h>
main()
{
// float a,b,c,d;
// double a,b,c,d;
long double a,b,c,d;
for(a=0.1;a<2000000;a+=0.1)
{
// b=sqrtf(a);
// b=sqrt(a);
b=sqrtl(a);
// to fool compiler optimizations....
// without this line a compiler may completely ignore above sqrt()
c=b;d=c;b=d;
}
};
I launched 'time test' several times, and averaged results for
my PIII 600Mhz are:
float: 2.96s, double: 3.76s, long double 5.49s
I compiled with `g++ -o test test` if you want to ask why g++, then I
can answer only: I was in hurry :)
--
Janek Kozicki |