Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!usenet.ukfsn.org!not-for-mail From: Martin Gregorie Newsgroups: comp.lang.java.programmer Subject: Re: Arithmetic overflow checking Date: Sun, 10 Jul 2011 18:07:37 +0000 (UTC) Organization: UK Free Software Network Lines: 40 Message-ID: References: <015aeb15-57db-48ab-9cd4-77f8448b632f@w24g2000yqw.googlegroups.com> <2rydnez7l-H5BYnTnZ2dnUVZ_vGdnZ2d@earthlink.com> <9LWdnZH2hdfmyYvTnZ2dnUVZ_vidnZ2d@posted.palinacquisition> NNTP-Posting-Host: 84.45.235.129 Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Trace: localhost.localdomain 1310321257 20174 84.45.235.129 (10 Jul 2011 18:07:37 GMT) X-Complaints-To: usenet@localhost.localdomain NNTP-Posting-Date: Sun, 10 Jul 2011 18:07:37 +0000 (UTC) User-Agent: Pan/0.133 (House of Butterflies) Xref: x330-a1.tempe.blueboxinc.net comp.lang.java.programmer:6054 On Sun, 10 Jul 2011 10:53:09 -0400, David Lamb wrote: > On 08/07/2011 12:30 AM, Eric Sosman wrote: >> On 7/7/2011 8:51 PM, Peter Duniho wrote: >>> [...] >>> I would not worry about the "simple" or "efficient" criteria. IMHO, if >>> one is deciding to apply overflow checking to every computation, one >>> has already abandoned the hope of efficiency. >> >> I've used machines that raised overflow traps "for free," > ... >> (The machines I speak of were from forty-odd years ago > > When microprocessors started to arrive on the scene, a lot of old-timey > hardware folks said they'd forgotten 30+ years of hardware design. When > operating systems for computers based on said processors came out, a lot > of old-timey software folks said they'd forgotten 30+ years of operating > system design. We seem to still be suffering the consequences. That happened not once, but twice. The first great leap backward was the minicomputer era, when the likes of the PDP-8 arrived with a single user, single tasking OS reminiscent of early computers, except they generally had teletypes instead of banks of switches and flashing lights. By then the better mainframes were multi- user, multitasking beasts. Then the first microcomputers arrived in the mid/late '70s. By this time the better minis had multi-tasking operating systems, but micros had re- implemented the earliest mini OSes - CP/M was near as dammit a copy of the old PDP-8 OS (RSTS?) from the late 60s - and the earliest micros even had switches and flashing lights (KIM-1, IMSAI 8080). By 1980 the minis were running UNIX but the latest and greatest micros had - drumroll - MS- DOS! -- martin@ | Martin Gregorie gregorie. | Essex, UK org |