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,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 29992 invoked from network); 2 Jul 2021 16:57:43 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 2 Jul 2021 16:57:43 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 249929C874; Sat, 3 Jul 2021 02:57:41 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 7B0249C864; Sat, 3 Jul 2021 02:57:19 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="SklC+upi"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id BF0F09C864; Sat, 3 Jul 2021 02:56:42 +1000 (AEST) Received: from mail-ua1-f54.google.com (mail-ua1-f54.google.com [209.85.222.54]) by minnie.tuhs.org (Postfix) with ESMTPS id 39F409C861 for ; Sat, 3 Jul 2021 02:56:42 +1000 (AEST) Received: by mail-ua1-f54.google.com with SMTP id f34so4065877uae.4 for ; Fri, 02 Jul 2021 09:56:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=YgMECl7I/EVBBBR6DuxKgRjqzthTMPWNdaTMz/iz5Hk=; b=SklC+upimXq1wqX0Br9ssLoQt3vy0j9g98Xx9EjUeoc2/gPLGaYsLTBNaM1M8LeGGh i1ngYQd5LPJbwJkOS9m6A9XlNek5cJkNO3MhsUhg5RlmwZrj/IeOK3G4NWSTZL+UJgEN orI3v7hbIsyvS8DJWYvjZEWLXSaKZ1ZCiaAFOWQPu/olhjijHGAOub71+UkPDC81tSLe zU0zQ2a788ALBFAkNkUx8rWMT5w08DM6vWt3eWPU9Tz7t9xA+0vHtAsmPKWJRLciTtcu gkLWzkTciDxftlZ1mVy9Z2YSF4n+kRt6aSthHnEeBhka0RQ3dsu/3kODHq60FI2dsjbq Ot6A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=YgMECl7I/EVBBBR6DuxKgRjqzthTMPWNdaTMz/iz5Hk=; b=jbWTchFcltonff7Ghy1mfbhS7Emou6crZn1zQCay3dtGt5IEHWKMmJTkIZcqLRLa4t 3UX7qHFjmFYnjOtWrns1wfG7eCStuUGwQhGA9xT+Gw/hnPSJ0D4x+qYNwqNboaHt0BNO qhg1QflYlGyHUxZ8sYLO8oC6dzNf1m+wvsDPbxVWnl2L4J4vfYi9J4bbS8WdZv4JjqnV A+npfqJwZwrkolLS7OPVEI0ACq+YGVrSIVCXUmmiWcIGfhVhAgMsx9aXD1J+JCnWe8mT 1Wf16clzE3JR5AV5gj3ak5evqI1403Z2tTGa5oCrELMFm65B2JmIj3qTexPm/E4XXUMh gG7A== X-Gm-Message-State: AOAM533FHmruMWsDYup0gsUDVJ481LBy5zG/8jjWQTzo2ejgU9kV8lmq kyhjETriO9NwpmLgVzdG67MOAC9aSaRhuyZgrvqIFp+z X-Google-Smtp-Source: ABdhPJwkJOcyHdj2BbeZAMJE+yK6ueK+NSn5Q3knc7eWkUeB+YoHyXlixlhLGymyPADzxqHO6UqagbMx9PGyo3hE690= X-Received: by 2002:ab0:20a6:: with SMTP id y6mr1042355ual.133.1625245000874; Fri, 02 Jul 2021 09:56:40 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:ab0:7517:0:0:0:0:0 with HTTP; Fri, 2 Jul 2021 09:56:40 -0700 (PDT) In-Reply-To: <0f8af9213f5e8a3c536047e580a9e5c8@yaccman.com> References: <0f8af9213f5e8a3c536047e580a9e5c8@yaccman.com> From: Paul Winalski Date: Fri, 2 Jul 2021 12:56:40 -0400 Message-ID: To: The Eunuchs Hysterical Society Content-Type: text/plain; charset="UTF-8" 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: , Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" 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