On Wed, 8 Sep 2010 08:35:42 -0600 Paul Gilmartin <[email protected]> wrote:
:>On Sep 8, 2010, at 05:39, robin wrote: :>> From: "Tony Harminc" :>> Sent: Wednesday, 8 September 2010 9:20 AM :>>> It's also how "classic" (base & displacement) addressing arithmetic, :>>> which we all know deals only with unsigned values, can subtract. :>> Classic base-displacement atithmetic is always addition, :>> never subtraction. :>Ahem. :> LH R1,=H'-4096' :> USING -4096,R1 :> LA R2,* :> LA R3,-4(,R2) :>What does R3 now address? Whatever it was addressing before the instruction. LA does not accept a negative displacement. :>This caused a great deal of debate on this list several years :>ago. Very few contributors got it right. -- Binyamin Dissen <[email protected]> http://www.dissensoftware.com Director, Dissen Software, Bar & Grill - Israel Should you use the mailblocks package and expect a response from me, you should preauthorize the dissensoftware.com domain. I very rarely bother responding to challenge/response systems, especially those from irresponsible companies.
