>
> I added CVS tree a new fft routine and table lookup method to calculate
> pow(2.0, ..).
>
> The speed is about 10% faster on my celeron linux box.
> ---
> Takehiro TOMINAGA // may the source be with you!
> --
I made the pow() table lookup a #define, set in machine.h:
#define POW20(x) pow20[x]
/*
#define POW20(x) pow(2.0,((double)(x)-210)*.25)
#define POW20(x) exp( ((double)(x)-210)*(.25*LOG2) )
*/
#define IPOW20(x) ipow20[x]
/*
#define IPOW20(x) exp( -((double)(x)-210)*.1875*LOG2 )
#define IPOW20(x) pow(2.0,-((double)(x)-210)*.1875)
*/
So the default will be table lookup, but you can go back to the old code
if you want.
All the noncritical pow() computations (like initialization data from
parameters given in db, or when it was outside of a loop) I reverted
back to pow(10.0,x) because this shouldn't effect speed, and it makes
it clearer that we are converting to/from db.
Mark
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