Re: Rep:Re: [f-cpu] Manual 0.2.6

[Michael Riepe <michael@stud.uni-hannover.de>]

On Sun, Aug 04, 2002 at 09:21:38PM +0200, cedric wrote:

[... cshift instruction...]
> I think you are right, because we have the mix/expand instruction. Currently 
> we must do something like this for 8 bits :
> 	mixl.b r1, r2, r9
> 	mixl.b r3, r4, r10
> 	mixl.b r5, r6, r11
> 	mixl.b r7, r8, r12
> 	mixl.d r9, r10, r13
> 	mixl.d r11, r12, r14
> 	mixl.q r13, r14, r15

Right.

> 7 cycles for 8 chunks, that's quite good. So no need of a more complex 
> instruction for small chunk and the cshift[l/r] will be enough (perhaps a 
> immediate version will be usefull).

An immediate version (cshift[rl]i) is not a problem.

I think an `arithmetic' right shift (cshiftra) is not useful; but what
about rotates (crotl/crotr)?

-- 
 Michael "Tired" Riepe <Michael.Riepe@stud.uni-hannover.de>
 "All I wanna do is have a little fun before I die"
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