From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FROM,HTML_MESSAGE,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 5509 invoked from network); 2 Jul 2021 18:08:33 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 2 Jul 2021 18:08:33 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 1F1549C87F; Sat, 3 Jul 2021 04:08:31 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id C0A8B9C864; Sat, 3 Jul 2021 04:07:42 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="r4MFXWrx"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 4314B9C864; Sat, 3 Jul 2021 04:07:41 +1000 (AEST) Received: from mail-yb1-f170.google.com (mail-yb1-f170.google.com [209.85.219.170]) by minnie.tuhs.org (Postfix) with ESMTPS id 236E59C861 for ; Sat, 3 Jul 2021 04:07:40 +1000 (AEST) Received: by mail-yb1-f170.google.com with SMTP id i18so17642819yba.13 for ; Fri, 02 Jul 2021 11:07:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=IeIdMByhTt8iJco0SkOFl9jBi7fUZUor4TXbR5yroVQ=; b=r4MFXWrxx8rultJrKjycmXemLoz32eoy8tBodb7AFcCeeUBKmp63Lz3rqtQBD9oDZ0 vLQ8e9kGyawX7AqSvMsDyzPu8jO3iPGd9IbR2EgXZbanStZtRwqfwabuK3tdI3FB1LTw s/ycN9DK7UiyEtkkLqNJcFCuCEd1U0GLaBTEPVgf1kFsb92kdOXqs2YyD5FUNEaobhgF 28b31mq/I0lcJLwvUq3MTljCyo9Fvm0P7i/ZWVCSLhBiZg/eKJB/dG4GcwZrVwnZn/t1 FRtnHmDyBxhFBsz675RcursjzvjEm81ZsFG1Fds52bjts4FMm8TbmyBAEopczGPicmWF fJDw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=IeIdMByhTt8iJco0SkOFl9jBi7fUZUor4TXbR5yroVQ=; b=XHpVPBLchcQl9iPMMJZseMepp/z1Ac5N04KJEBFpjBaNeCrrn4a2cgfuhyzJlTJnjP vokgXkJZRz+b93M6z88pksGQswoVqE8Dc0nFq748jOkJKDCZV8VqxYUpT5b1Y4jyTitu 9k0k5PsGCRfAUWwdW6CaP4AWbWOBDu7Bh8QhC+SZHgUBsx5UPHNGoDGACjg4NGImiEMX 0vMKDGLAtFA1LfDK4bqgIH5Xq8BDOYCUcjlqNYKj6E1yB06Z0DgvLknYx94MawgO2fF2 AxgTr0WKpHuus5FxnSUVjKyrMtPG91NipB0zG1u42pdHMGZ3dMgPSksYOtlCNi3+qkN9 4z5w== X-Gm-Message-State: AOAM533GaBTtxk9gFg/vl0u6jCG9+eG39dOPgi/QH6Q4u0L+aC5DoqDc 9JiHA99M7FmITN8aUtfi/kwmAgFwz4dMFGp1FQs= X-Google-Smtp-Source: ABdhPJyN2hAF0JDHP+zF76//rWewI7CnYnkXYQ4AxNnSbnKT9qoK7nP3lyl/mxYWvk4tDgP0hd3oREMgjcCfQda3UtY= X-Received: by 2002:a25:b741:: with SMTP id e1mr849804ybm.347.1625249259045; Fri, 02 Jul 2021 11:07:39 -0700 (PDT) MIME-Version: 1.0 References: <0f8af9213f5e8a3c536047e580a9e5c8@yaccman.com> In-Reply-To: From: "John P. Linderman" Date: Fri, 2 Jul 2021 14:07:27 -0400 Message-ID: To: Paul Winalski Content-Type: multipart/alternative; boundary="000000000000c1c43505c627d482" Subject: Re: [TUHS] Disassemblers X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: The Eunuchs Hysterical Society Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" --000000000000c1c43505c627d482 Content-Type: text/plain; charset="UTF-8" On a related (optimization) theme, https://research.swtch.com/hwmm On Fri, Jul 2, 2021 at 12:58 PM Paul Winalski wrote: > I sent a reply to this message to the TUHS mailing list but gmail may > have rejected it and flagged it as spam. > > Please email me privately to let me know if the message made it to the > list. > > -Paul W.. > > On 7/1/21, scj@yaccman.com wrote: > > I saw this post and it reminded me of a meeting that Dennis and I had > > with Bill Wulf. At one point, Dennis decided to write an optimizer but > > gave up after a week or two because when he had coded the data > > structures he needed he had filled up the PDP-11 memory! It was a very > > strong part of the Unix meme that Unix and C would run on small > > computers since most of the universities couldn't afford bigger ones at > > the time. > > > > When PCC came along and started running on 32-bit machines, I started > > thinking about algorithms for optimization. A problem that I had no > > good solution for could be illustrated by a simple piece of code: > > > > x = *p; > > > > y = *q; > > > > q gets changed > > > > *q = z; > > > > The question is, do I need to reload x now because q might have been > > changed to point to the same place as p? At around this time, Al Aho > > was invited to go to CMU and give a talk, and he invited me to come with > > him. We spent about an hour and a half one-on-one with Bill Wulf -- I > > seem to remember a lot of mutual respect going on. But when I asked him > > about my problem, he really didn't have much to say about it. I finally > > got him to agree that his compiler had a bug. But he said there was a > > flag they could set on the compiler that would turn of optimization and > > if your program had mysterious bugs, you should use the flag. > > > > I recall that Al, always in search of better algorithms, was a bit > > disappointed -- I was a bit more pragmatic about it. On the whole, it > > was a good meeting, and the "Engineering ... Compiler" book was one of > > my favorites when it came out. > > > > Steve > --000000000000c1c43505c627d482 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
On = a related (optimization) theme,
https://resear= ch.swtch.com/hwmm


On Fri, Jul 2, 2021 at 12:58 PM Paul Winalski <paul.winalski@gmail.com> wrot= e:
I sent a repl= y to this message to the TUHS mailing list but gmail may
have rejected it and flagged it as spam.

Please email me privately to let me know if the message made it to the list= .

-Paul W..

On 7/1/21, scj@yaccman= .com <scj@yaccm= an.com> wrote:
> I saw this post and it reminded me of a meeting that Dennis and I had<= br> > with Bill Wulf.=C2=A0 At one point, Dennis decided to write an optimiz= er but
> gave up after a week or two because when he had coded the data
> structures he needed he had filled up the PDP-11 memory!=C2=A0 =C2=A0I= t was a very
> strong part of the Unix meme that Unix and C would run on small
> computers since most of the universities couldn't afford bigger on= es at
> the time.
>
> When PCC came along and started running on 32-bit machines, I started<= br> > thinking about algorithms for optimization.=C2=A0 A problem that I had= no
> good solution for could be illustrated by a simple piece of code:
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 x =3D *p;
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 y =3D *q;
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 q gets changed
>
>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 *q =3D z;
>
> The question is, do I need to reload x now because q might have been > changed to point to the same place as p?=C2=A0 =C2=A0At around this ti= me, Al Aho
> was invited to go to CMU and give a talk, and he invited me to come wi= th
> him.=C2=A0 We spent about an hour and a half one-on-one with Bill Wulf= -- I
> seem to remember a lot of mutual respect going on.=C2=A0 But when I as= ked him
> about my problem, he really didn't have much to say about it.=C2= =A0 I finally
> got him to agree that his compiler had a bug.=C2=A0 But he said there = was a
> flag they could set on the compiler that would turn of optimization an= d
> if your program had mysterious bugs, you should use the flag.
>
> I recall that Al, always in search of better algorithms, was a bit
> disappointed -- I was a bit more pragmatic about it.=C2=A0 On the whol= e, it
> was a good meeting, and the "Engineering ... Compiler" book = was one of
> my favorites when it came out.
>
> Steve
--000000000000c1c43505c627d482--