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 autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 9095 invoked from network); 1 Dec 2021 22:11:45 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 1 Dec 2021 22:11:45 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id DCD2D9CF1F; Thu, 2 Dec 2021 08:11:42 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 6450A9C78B; Thu, 2 Dec 2021 08:09:32 +1000 (AEST) Received: by minnie.tuhs.org (Postfix, from userid 112) id 97FFD9C78B; Thu, 2 Dec 2021 08:09:30 +1000 (AEST) Received: from darkstar.fourwinds.com (fourwinds.com [63.64.179.162]) by minnie.tuhs.org (Postfix) with ESMTPS id 6230094502 for ; Thu, 2 Dec 2021 08:09:29 +1000 (AEST) Received: from darkstar.fourwinds.com (localhost [127.0.0.1]) by darkstar.fourwinds.com (8.16.1/8.15.2) with ESMTP id 1B1M9SVm123403 for ; Wed, 1 Dec 2021 14:09:28 -0800 Received: from darkstar.fourwinds.com (jon@localhost) by darkstar.fourwinds.com (8.16.1/8.15.2/Submit) with ESMTP id 1B1M9SbS123400 for ; Wed, 1 Dec 2021 14:09:28 -0800 Message-Id: <202112012209.1B1M9SbS123400@darkstar.fourwinds.com> From: Jon Steinhart To: TUHS main list In-reply-to: <4FA7E5AA-C673-491F-9874-26E2165F51A7@serissa.com> References: <4FA7E5AA-C673-491F-9874-26E2165F51A7@serissa.com> Comments: In-reply-to Lawrence Stewart message dated "Wed, 01 Dec 2021 16:14:02 -0500." MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-ID: <123398.1638396568.1@darkstar.fourwinds.com> Content-Transfer-Encoding: 8bit Date: Wed, 01 Dec 2021 14:09:28 -0800 X-JON-SPAM: local delivery 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: , Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" Lawrence Stewart writes: > I don’t think this is right. The irregular parts of die photographs didn’t > 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. Yes and no. The irregular parts of die photographs are from the instantiation of random logic. The point that I obviously failed to make earlier is that it looks way different than the instantiation of more regular logic. But there's also a historical element here and I was living in the past. Sure, what you say is true of modern designs which I haven't been involved with; my current history is limited to FPGA designs. But, going back a while, look up Rubylith (no relation to Ruby) which is how ICs were laid out pre-CAD days. The regular and random parts look remarkably similar to the way that they do today. No compilers needed to make things look that way. Just for some more BTL history, I started doing work on CAD software around 1985. I'm thinking that it was maybe 1988 or 1989 when a bunch of area 10 folks (Carl, Greg, Hal, ...) left BTL to found what I think was called Silicon Design Labs which eventually merged with Silicon Compilers (or the other way around). I think that they were later bought out by one of the current big CAD system survivors. Jon