Re: Mathematical Funktions for H8/300h - double ?

["Kai Ruottu" <karuottu@freenet.hut.fi>]

> After playing around with gdb and the evaluation board I tried the 
> math functions to see, how exact they are with the small program (at 
> the end of this message) for both the float and the double type. 
> 
> Does anybody know what the reasons for this problem are ? Is there 
> no double precision calculation this way on the h8/300 for some 
> reason.

 Yes, the 'double' is the same 32-bit type as 'float'. The reason seems
to be that a 8/16-bit processor is not expected to be used in 'number 
crunching'. Handling 64-bit floating point numbers will be quite slow.

 I cannot say if adding the support for a real 64-bit 'double' needs more
than changing the fiddlings with the 'fp-bit.c'/'dp-bit.c' (if the '.md'
file generates code for 64-bit entities like 64-bit 'long' and 'double').
Has anyone tried adding the 64-bit 'double' ?

Cheers, Kai
_______________________________________________
New CrossGCC FAQ: http://www.objsw.com/CrossGCC
_______________________________________________
To remove yourself from the crossgcc list, send
mail to crossgcc-request@cygnus.com with the
text 'unsubscribe' (without the quotes) in the
body of the message.