Subject: Re: rc5des on NetBSD/vax
To: Ignatios Souvatzis <email@example.com>
From: Johnny Billquist <bqt@Update.UU.SE>
Date: 02/23/1999 20:17:26
On Tue, 23 Feb 1999, Ignatios Souvatzis wrote:
> On Sun, Feb 21, 1999 at 04:13:18PM -0500, Dave McGuire wrote:
> > >Opcode 9C, ROTL - rotate long. There are also shift instructions for 32
> > >and 64bit operands: ASHL and ASHQ. I'd guess that with some hand
> > >optimized assembler we'd see better performance. God only knows what
> > >other VAX instructions could be used or abused into speeding up things.
> RC5 needs 4 basic operations:
> - ADD
> - XOR
> - ROT by the constant 3
> - ROT by (a variable % 32)
> Are all available?
Yes. ROT can rotate an arbitrary number of places to the right or left.
VAX is the ultimate CISC, if a VAX can't do it, it most likely can't be
done with one intruction...
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: firstname.lastname@example.org || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol