AVR-Chat

On Jul 17, 2009, at 5:43 PM, Adeilton Oliveira wrote:

> I don't know how the division operation is internally implemented,  
> but I
> think in your case you can use >>4 instead of /16.


Its a simple matter to examine the generated assembly with the  
debugger in AVR Studio. Or to ask avr-gcc (WinAVR) to leave the  
assembly laying around after a compile, or to generate a disassembly  
from the object file.

Think you will find avr-gcc is smart enough to >>4 for a constant / 
16. I know it will replace /2 with a right shift.

Meanwhile using the division in one's source is usually the right  
thing to do for human comprehension. Replacing division with shifts  
is one of those things that makes assembly harder for someone other  
than the original author to understand. Makes it harder for the  
original author to understand 6 months after it was written.

--
David Kelly N4HHE, dkelly@HiWAAY.net
========================================================================
Whom computers would destroy, they must first drive mad.