[PATCH] MIPS gas: Support for drol/dror macros (was: Re: [PATCH] MIPS gas: 64 bit aware rol/ror macros)

[Paul Koning]

Excerpt of message (sent 15 May 2002) by Thiemo Seufer:
> Eric Christopher wrote:
> > Do we need yet another macro instruction?
> 
> Probably the compiler will never use any rotate macro, but it's useful
> for assembler programmers creating e.g. efficient cryptography routines.

I doubt that.  One of the hassles for assembly language programming on
MIPS is the constant struggle to remember what's a real instruction
and what's a macro.  If you code in assembler for very low level stuff
(bootstraps etc.) that doesn't matter.  If you're coding for ultimate
efficiency, it matters a whole lot.  I certainly would not use a ROTx
macro for the rotates in crypto, because I would want to schedule the
code myself, and the macros only get in the way when you do that.

In fact, the performance critical loop of an assembler routine I'm
working on right now is going to get a .set nomacro in effect on the
whole thing for this precise reason.

     paul