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-Thread: 103376,eb896440a3af23cf X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news4.google.com!news.glorb.com!border1.nntp.dca.giganews.com!nntp.giganews.com!local1.nntp.dca.giganews.com!nntp.megapath.net!news.megapath.net.POSTED!not-for-mail NNTP-Posting-Date: Wed, 10 Nov 2004 18:05:39 -0600 From: "Randy Brukardt" Newsgroups: comp.lang.ada References: Subject: Re: large arrays Date: Wed, 10 Nov 2004 18:07:14 -0600 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.50.4807.1700 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4910.0300 Message-ID: <8YydnRLh6b1OMQ_cRVn-uw@megapath.net> NNTP-Posting-Host: 64.32.209.38 X-Trace: sv3-vh4GFHcb/D+Ev3QktaaQaCLKPA8lHOyGrKZiqmA3tcwkzEXTiakjNw2Ptha05+0SYOaFiPabG1URlvf!aQSqoOuqHf7SSDkrvdJDiVUG1ySLEAuxPdbQT2G7EafwOD5DqhxfFQu4f8JZovTFaLdtBaPePl01 X-Complaints-To: abuse@megapath.net X-DMCA-Complaints-To: abuse@megapath.net X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.20 Xref: g2news1.google.com comp.lang.ada:6132 Date: 2004-11-10T18:07:14-06:00 List-Id: "Jeff C r e e.m" wrote in message news:kNckd.488755$mD.84928@attbi_s02... > From the GNAT RM (6.2) > > The largest Size value permitted in GNAT is 2**31-1. Since this is a Size > in bits, this corresponds to an object of size 256 megabytes (minus one). > This limitation is true on all targets. The reason for this limitation is > that it improves the quality of the code in many cases if it is known that a > Size value can be accommodated in an object of type Integer. For what it's worth (probably nothing :-), Janus/Ada doesn't limit objects on 32-bit architectures. We manage everything in terms of bytes, and only calculate 'Size if someone asks for it (which might raise Constraint_Error for really large objects). But I have to sympathize with GNAT; the allocate-in-bytes designs needs a lot of hacks to make it work for all of the sorts of representation items, and I certainly can see why someone wouldn't want to do that. Someone also complained that this limitation exists on all targets; I'm sure that's because the compiler front-end uses 32-bit values for 'Size on all targets. Otherwise, you'd have to have a 64-bit compiler before you could compile the 64-bit compiler (we faced this same issue on the 36-bit Unisys system). Randy.