From owner-sc22wg5@open-std.org Thu Nov 6 02:04:11 2008 Return-Path: X-Original-To: sc22wg5-dom7 Delivered-To: sc22wg5-dom7@www2.open-std.org Received: by www2.open-std.org (Postfix, from userid 521) id 52ACACA343A; Thu, 6 Nov 2008 02:04:11 +0100 (CET) X-Original-To: sc22wg5@open-std.org Delivered-To: sc22wg5@open-std.org X-Greylist: delayed 542 seconds by postgrey-1.18 at www2.open-std.org; Thu, 06 Nov 2008 02:04:10 CET Received: from brmea-mail-1.sun.com (brmea-mail-1.Sun.COM [192.18.98.31]) by www2.open-std.org (Postfix) with ESMTP id 58BBCCA3434 for ; Thu, 6 Nov 2008 02:04:09 +0100 (CET) Received: from dm-sfbay-01.sfbay.sun.com ([129.145.155.118]) by brmea-mail-1.sun.com (8.13.6+Sun/8.12.9) with ESMTP id mA60t5rA003379 for ; Thu, 6 Nov 2008 00:55:06 GMT Received: from ranma.sfbay.sun.com (ranma.SFBay.Sun.COM [129.146.84.89]) by dm-sfbay-01.sfbay.sun.com (8.13.8+Sun/8.13.8/ENSMAIL,v2.2) with ESMTP id mA60t5aA019399 for ; Wed, 5 Nov 2008 16:55:05 -0800 (PST) Received: (from michaeli@localhost) by ranma.sfbay.sun.com (8.11.7p1+Sun/8.11.7) id mA60t5s10241 for sc22wg5@open-std.org; Wed, 5 Nov 2008 16:55:05 -0800 (PST) Date: Wed, 5 Nov 2008 16:55:05 -0800 (PST) From: Michael Ingrassia Message-Id: <200811060055.mA60t5s10241@ranma.sfbay.sun.com> To: sc22wg5@open-std.org Subject: N1751 X-Sun-Charset: US-ASCII Sender: owner-sc22wg5@open-std.org Precedence: bulk There's a premiss in N1751.txt that I'm not sure I believe, although I may be reading it wrong. >Segments Pi and Qj are unordered, and it is therefore permitted for a >processor to execute segment Qj to completion before starting segment Pi. I accept that in theory, there is no argument based solely on segment ordering to disallow a processor to execute segment Qj to completion before starting segment Pi. But do we actually say that a processor is permitted to predicate the start of segment Pi on the completion of a different segment? I didn't think so. And if not, then doesn't the principle of Get On With It (or whatever you might call it) say that the processor has to eventually start Pi? After all, we don't worry that the PRINT will never happen in R = SIN(3.04789232) PRINT *, R because the processor might never get around to advancing the program counter. Maybe the principle is that an implementation risks being incorrect if it introduces extra segment orderings (Qj must precede Pi) not implied by the standard. In other words, this is a processor problem not a user problem. What am I missing? --Michael I.