Re: [Amforth-devel] Floating point - f* f/ in asm

[pito <pi...@vo...>]

Hi, the last one is f-. Even the amforth overhead compared to asm
float primitives is huge I did f- in asm too (all measurements
@25MHz):

> > test_empty_loop
> 4.0894465E-5 sec per empty loop operation ok

f- :

> test_sub_asm
4.0894465E-5 sec per fsub-asm operation ok
> _pi _pi f* _pi f- fs.
6.728013  ok
> _pi _pi f+ _pi f- fs.
3.141593  ok
> -10000 s>f -20000 s>f f- fs.
1.0E4  ok
>

PS: I am still thinking why the amforth overhead is so big?? It
seems from my naive measurements a typical forth word takes ~7us
plus minus.
This is about 175 clock cycles @25MHz, or aprox 100 instructions -
could it be so much? Just a stupid Q. Pito