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=-1.0 required=5.0 tests=MAILING_LIST_MULTI, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 32189 invoked from network); 1 Apr 2022 17:17:12 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 1 Apr 2022 17:17:12 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id A4CDD9D6FD; Sat, 2 Apr 2022 03:17:07 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 2BAF39D6FA; Sat, 2 Apr 2022 03:15:20 +1000 (AEST) Received: by minnie.tuhs.org (Postfix, from userid 112) id F0F9D9D6FA; Sat, 2 Apr 2022 03:15:15 +1000 (AEST) Received: from mail-oa1-f50.google.com (mail-oa1-f50.google.com [209.85.160.50]) by minnie.tuhs.org (Postfix) with ESMTPS id 0B6B19D6F9 for ; Sat, 2 Apr 2022 03:15:15 +1000 (AEST) Received: by mail-oa1-f50.google.com with SMTP id 586e51a60fabf-d6e29fb3d7so3376188fac.7 for ; Fri, 01 Apr 2022 10:15:15 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :reply-to:content-transfer-encoding:message-id:references:to; bh=ZQOIyOtObYVURiCYkEbz8Pyqv2n7FeG1VnTSyiEj9B0=; b=gvkqUznkG2wOlt09JyvVXAUu8kBvl+PkNxauoHekc9C1joss6n2iD1/Kb3iFAgmzKW WxSKKdsXClr42IdI44z3qT2wysWIERubXxmoSRMckJrElG8MGR2rbosNE40EyOrhKYB8 ZTryYQ9T7xuLbaYdnDvmVyEY5Jwn1PMHsgJiGOhl9k1c+lfsoGeswqk06OtxXN/qHYyV K/NPAoT2Hp4RiZslooTuMlKU2auUkIljo+qSlNgpncpFYXCzckT3+JcewOAeR6TM3tBM FjsVy2NXodRkNMUDrzfhaFCeG1fi4ymN0HA4gioGK/5WiEar5ntd55Vw0JpGGDiahUzP FJmQ== X-Gm-Message-State: AOAM532x9NeoXo1tCOF9cDJUfywVXlfSo8aU1l55D2UXUl+lpxCLkkh3 PUp/Q4Zd+Hl/F4QzczNL/+o= X-Google-Smtp-Source: ABdhPJxO52/HE829ygKSmv/m0ouAfVjdSEG4+MhY6XYgp176FUcwtAfYCSxvVSqmSGe0Q9cVErSzlg== X-Received: by 2002:a05:6870:4182:b0:da:b3f:322c with SMTP id y2-20020a056870418200b000da0b3f322cmr5449738oac.220.1648833314233; Fri, 01 Apr 2022 10:15:14 -0700 (PDT) Received: from kdbarto.org (107-193-50-41.lightspeed.sndgca.sbcglobal.net. [107.193.50.41]) by smtp.gmail.com with ESMTPSA id t19-20020a05687044d300b000de4e33171csm1163138oai.34.2022.04.01.10.15.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 01 Apr 2022 10:15:13 -0700 (PDT) Received: from smtpclient.apple (zaphod.local [IPv6:fe80::24:a9bd:b16c:97e1]) by kdbarto.org (Postfix) with ESMTPS id E1D3C2CCEA9F; Fri, 1 Apr 2022 10:15:11 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 15.0 \(3693.60.0.1.1\)) From: David Barto In-Reply-To: Date: Fri, 1 Apr 2022 10:15:11 -0700 Content-Transfer-Encoding: quoted-printable Message-Id: <44FEFAE6-720F-4449-84DB-228B7A6C097C@kdbarto.org> References: To: Douglas McIlroy X-Mailer: Apple Mail (2.3693.60.0.1.1) Subject: Re: [TUHS] A Reiser tour de force 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: , Reply-To: david@kdbarto.org Cc: TUHS main list Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" > On Apr 1, 2022, at 8:59 AM, Douglas McIlroy = wrote: >=20 > The recent discussion about Research choosing BSD's paging over > Reiser-London's brought to mind a stunning program by Reiser that > Research did adopt. >=20 > A critical primitive in the Blit terminal was bitblt (block transfer > of a rectangular area). It was used ubiquitously, for example to > refresh data when window-stacking changed, to move data within a > window, or to pop up a menu.. The display memory was word-oriented, so > bitblt was fraught with niggling details about bit alignment and > overlap of source and destination. A general bitblt subroutine was a > rats' nest of conditionals--grossly inefficient for important special > cases like scrolling. >=20 > Bitblt got refined (i.e. elaborated) several times before Reiser did > away with it entirely. Instead he wrote a just-in-time generator of > optimal code. Thousands of distinct variants, which varied in size > from 16 to 72 bytes, could be produced by the same 400 lines of > assembler code. >=20 > Doug Does this exist for the rest of us to study? David=