From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,db5c6b2ef47d4b9e X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-06-21 17:01:41 PST Path: archiver1.google.com!newsfeed.google.com!newsfeed.stanford.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!newsfeed.cwix.com!sjc-peer.news.verio.net!news.verio.net!iad-read.news.verio.net.POSTED!kilgallen From: Kilgallen@eisner.decus.org.nospam (Larry Kilgallen) Newsgroups: comp.lang.ada Subject: Re: short-circuit control forms (& 'long names are doom') Message-ID: References: <3B30F836.D700DAA3@raytheon.com> <3B32038D.F1296C79@cadence.com> Organization: LJK Software Date: 21 Jun 2001 20:01:33 -0500 NNTP-Posting-Host: 216.44.122.34 X-Complaints-To: abuse@verio.net X-Trace: iad-read.news.verio.net 993168095 216.44.122.34 (Fri, 22 Jun 2001 00:01:35 GMT) NNTP-Posting-Date: Fri, 22 Jun 2001 00:01:35 GMT Xref: archiver1.google.com comp.lang.ada:9016 Date: 2001-06-21T20:01:33-05:00 List-Id: In article , Charles Hixson writes: > Short-Cut Booleans: Sometimes these are mandatory. They rarely > do harm in current code. But they may limit the optimization > that will be possible in the future. I can quite imagine a > compiler that decides that a multi-processor should run the > logic tests in parallel, unless they were simple expressions or > short-cut forms. There is no need to look to the future or restrict the venue only to multiprocessors. Some modern uniprocessor systems have chips that are capable of "out of order" execution. Compilers for such machines must take explicit action to prevent this if mandated by shortcut bookean expressions.