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=-0.8 required=5.0 tests=DKIM_INVALID,DKIM_SIGNED, MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 3083 invoked from network); 1 Dec 2021 21:23:16 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 1 Dec 2021 21:23:16 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id EB96C9CF12; Thu, 2 Dec 2021 07:23:13 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 988199C78B; Thu, 2 Dec 2021 07:20:54 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=serissa.com header.i=@serissa.com header.b="mkOJD9S4"; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=messagingengine.com header.i=@messagingengine.com header.b="cVog9/DO"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id A69B89C78B; Thu, 2 Dec 2021 07:20:52 +1000 (AEST) X-Greylist: delayed 404 seconds by postgrey-1.36 at minnie.tuhs.org; Thu, 02 Dec 2021 07:20:51 AEST Received: from out5-smtp.messagingengine.com (out5-smtp.messagingengine.com [66.111.4.29]) by minnie.tuhs.org (Postfix) with ESMTPS id B260294502 for ; Thu, 2 Dec 2021 07:20:51 +1000 (AEST) Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.nyi.internal (Postfix) with ESMTP id 8BD2A5C019F; Wed, 1 Dec 2021 16:14:06 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute1.internal (MEProxy); Wed, 01 Dec 2021 16:14:06 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=serissa.com; h= content-type:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; s=fm1; bh=C ZxLqKjWocKmqcxL+DUQz8+fqS0Kx5zT2NldYKBb6gw=; b=mkOJD9S4rQ5Rd53jU Pb8tW+uSIcKQUGSzQjOCULwRYAaUZvYB2bUhNYMjpljhJiHxDpuvUcUkM6bVHgZf u+S1B9a8caflzJJqvtSxIwp3jCstN/kg0CGixPNsRfExo74oRFSMLC3uP28yqKdY HPaeDW7Y8NLTz3xs5ySvKeiaLl5qC3WDqdWyisyiLPgeRJYilFQaMKiDVu/8Le6L 1iiMDu55Qx9mmDhq8ZJeIeM864UOW/jpbPMzp+A8qawsuFx/a9ZbcCcWzC5SAE2j NHXSngFgjjolgAnGFnEawJP2Nx6LWDYvwY2m6nDUrzTfQZJ+Yfk3nis2MZFiYscS oIZTw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm1; bh=CZxLqKjWocKmqcxL+DUQz8+fqS0Kx5zT2NldYKBb6 gw=; b=cVog9/DO/YOe2HLvxyAqkqenkNYp2rMZJmPgPogdF4XspUSt+W06JyTil woGNQC53XiLkZ3UcKjgILQDGBfaObJmjHQsGKGAfaUQJnW4syuGQwR1Y1YLzlyui bvAFx/YVMrptF3vhKbysC8GBmOgu6m94g6Ac/VgIHXKdSqL8h8gMJdFwbrf2VdUo 2+yhErznL0WdW2HMT0MdeT1ffiEqs+UD4paNZPiuAZ4dPmDqyDkJ6TxUTlYkl+dQ d4KZTQktNhqwY03tj+dig28HfpeeX0aorJNloCSz5HZBzjcS6cTJVSiuO9rTkZzW G4TtfHooiUf/UwGXqapPM/jsWQnPw== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvuddrieefgddugeejucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurheptggguffhjgffgffkfhfvofesthhqmhdthhdtjeenucfhrhhomhepnfgrfihr vghntggvucfuthgvfigrrhhtuceoshhtvgifrghrthesshgvrhhishhsrgdrtghomheqne cuggftrfgrthhtvghrnhepgefgjefftdejieefheevkefffffhueehieeiiedvjeefleel keeuvedvffeihfdvnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilh hfrhhomhepshhtvgifrghrthesshgvrhhishhsrgdrtghomh X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Wed, 1 Dec 2021 16:14:06 -0500 (EST) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 15.0 \(3693.20.0.1.32\)) From: Lawrence Stewart In-Reply-To: Date: Wed, 1 Dec 2021 16:14:02 -0500 Content-Transfer-Encoding: quoted-printable Message-Id: <4FA7E5AA-C673-491F-9874-26E2165F51A7@serissa.com> References: To: Douglas McIlroy X-Mailer: Apple Mail (2.3693.20.0.1.32) Subject: Re: [TUHS] Encoding an ISA: Random Logic vs. Control Stores 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: TUHS main list Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" > On 2021, Dec 1, at 9:55 AM, Douglas McIlroy = wrote: >=20 > My take on defining random logic >=20 > random logic : hardware :: spaghetti code : software >=20 > Doug I don=E2=80=99t think this is right. The irregular parts of die = photographs didn=E2=80=99t get that way because the hardware engineers = were writing bad (spaghetti) code. They got that way due to several = levels of optimizing tools working over quite sensible RTL or System C = code or whatever. You might as well ding the output of -O3 for being = incomprehensible. You might get the same logic by writing a clean state machine and = letting the tools minimize the control rom into gates (good) or by = writing the gates yourself (bad). You can=E2=80=99t tell without = looking at the sources. Software coding: You write the conrol flow and the compiler generates = the datapath Hardware coding: You write the datapath and the compiler does the = control logic.