Re: [PATCH] ppc32 use simplified mmenonics

Vincent Hanquez
2004-08-22T19:17:33Z

On Sun, Aug 22, 2004 at 10:29:00AM -0400, Albert Cahalan wrote:
> That comes to 2304. Subtract the 456 "simplified"
> instruction names you have. That leaves 1848 that
> you are unable to access.
>
> Take a look at the crand instruction. It uses numbers.
> Now, just imagine mixing that with branch instructions
> that hide the numbers. I hope you see the problem.

I never said we should use simplified instructions everywhere there are
instructions. Hence I don't see why we care here about 1848 instructions
not beeing accessible. Most of thoses 1848 instructions probably fit in the
'not so much' used, and thus doesn't need a simplified mmenonic.

> It doesn't appear to be so. He wrote:
>
> : Oh well.. I've got quite used to tweaking rlwinm directly
> : but I suppose it's more clear for others to go to clrrwi.
>
> So I'd like him to know that others like rlwinm directly too.

sure.

and some other prefer simplified instructions. I guess we're hitting a
wall here :)

But as clrrwi is already use in the kernel (as a lot of others simplified
instructions), either send a patch to remove them or don't say that this
is madness.

> Using instructions that are in the index makes sense.
> Using a zillion poorly documented alternatives is madness.

Maybe then you should rewrite all part of kernels, gcc, objdump and gdb that
use/disassemble the code with simplified instructions (mr, li, b*, etc...) too.
(clrrwi is as documented as mr)

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