From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <88b41190969914dbec1b2ec70f7b923c@terzarima.net> To: 9fans@cse.psu.edu Subject: Re: [9fans] fp: stack underflow error From: Charles Forsyth Date: Fri, 2 Jul 2004 11:53:48 +0100 In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="upas-lmxuwxwaeiwtrjycozupqjdlgx" Topicbox-Message-UUID: b35e6724-eacd-11e9-9e20-41e7f4b1d025 This is a multi-part message in MIME format. --upas-lmxuwxwaeiwtrjycozupqjdlgx Content-Disposition: inline Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit i assumed the list of opcodes and short instruction descriptions was correct, and that indeed, being a manly lot, the floating-point implementers who wrote that section loftily regarded 32-bits as being the bare minimum for a `word', and included decent 64-bits within the term. (hence the reference to `short-integer' for the 16-bit runts.) still, in this case i think the 8.out 708: suicide: sys: fp: stack underflow fppc=0x1118 status=0x80a1 pc=0x0000118f is saying stack underflow only because /sys/src/9/pc/main.c isn't reading the status correctly, unless i'm getting the bits wrong myself compared to the handbook. i think it's `inexact result (precision error)'. 0x40 is set for stack fault; it's checking for (status & 0x30), although perhaps (status & 0x30) == 0 was intended, to avoid masking other faults? the exception flags are sticky. that would be good because i couldn't see the incorrect stacking in the 8c code. --upas-lmxuwxwaeiwtrjycozupqjdlgx Content-Type: message/rfc822 Content-Disposition: inline Received: from mail.cse.psu.edu ([130.203.4.6]) by lavoro; Fri Jul 2 11:27:51 BST 2004 Received: from psuvax1.cse.psu.edu (localhost [127.0.0.1]) by mail.cse.psu.edu (CSE Mail Server) with ESMTP id 909821A1B2 for ; Fri, 2 Jul 2004 06:25:57 -0400 (EDT) X-Original-To: 9fans@cse.psu.edu Delivered-To: 9fans@cse.psu.edu Received: from localhost (neuromancer.cse.psu.edu [130.203.4.2]) by mail.cse.psu.edu (CSE Mail Server) with ESMTP id B501F19F49 for <9fans@cse.psu.edu>; Fri, 2 Jul 2004 06:25:44 -0400 (EDT) Received: from mail.cse.psu.edu ([130.203.4.6]) by localhost (neuromancer [130.203.4.2]) (amavisd-new, port 10024) with LMTP id 10405-01-32 for <9fans@cse.psu.edu>; Fri, 2 Jul 2004 06:25:43 -0400 (EDT) Received: from collyer.net (unknown [216.240.55.168]) by mail.cse.psu.edu (CSE Mail Server) with ESMTP id 0089D19F15 for <9fans@cse.psu.edu>; Fri, 2 Jul 2004 06:25:42 -0400 (EDT) Message-ID: To: 9fans@cse.psu.edu Subject: Re: [9fans] fp: stack underflow error From: Geoff Collyer Date: Fri, 2 Jul 2004 03:25:41 -0700 In-Reply-To: <626179c9c80b6b82cfbaa9789a485bac@terzarima.net> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Virus-Scanned: by amavisd-new at cse.psu.edu X-BeenThere: 9fans@cse.psu.edu X-Mailman-Version: 2.1.5 Precedence: list Reply-To: Fans of the OS Plan 9 from Bell Labs <9fans@cse.psu.edu> List-Id: Fans of the OS Plan 9 from Bell Labs <9fans.cse.psu.edu> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: 9fans-bounces+forsyth=terzarima.net@cse.psu.edu Errors-To: 9fans-bounces+forsyth=terzarima.net@cse.psu.edu `word- or short-integer format' only can't be right, since `word' in intel manuals means 16-bits (even in their 64-bit processor manuals, I imagine), and 32-bit signed integers do work. --upas-lmxuwxwaeiwtrjycozupqjdlgx--