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=unavailable autolearn_force=no version=3.4.4 Path: buffer1.nntp.dca1.giganews.com!border1.nntp.dca1.giganews.com!nntp.giganews.com!newspeer1.nac.net!feeder.erje.net!eu.feeder.erje.net!eternal-september.org!feeder.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Simon Clubley Newsgroups: comp.lang.ada Subject: Re: Integer Overflow Question. Date: Mon, 25 Aug 2014 13:09:35 +0000 (UTC) Organization: A noiseless patient Spider Message-ID: References: <9c5de333-276c-4e3a-be5a-4e5a98cdaa1d@googlegroups.com> <440bf1f1-3e98-47ac-b0c0-f73f170a3603@googlegroups.com> Injection-Date: Mon, 25 Aug 2014 13:09:35 +0000 (UTC) Injection-Info: mx05.eternal-september.org; posting-host="e458ff8b81bc0c159989eb0e36c6e372"; logging-data="10800"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+lM8VOHjKW4craNHb+VoXiMfEEUCM93ok=" User-Agent: slrn/0.9.8.1 (VMS/Multinet) Cancel-Lock: sha1:lKBzQ9rGIg6FAQkMr8L2DarOFQA= Xref: number.nntp.dca.giganews.com comp.lang.ada:188650 Date: 2014-08-25T13:09:35+00:00 List-Id: On 2014-08-25, austin.obyrne769@btinternet.com wrote: > On Monday, August 25, 2014 12:46:01 PM UTC+1, G.B. wrote: >> On 25.08.14 13:21, austin.obyrne769@btinternet.com wrote: >> >> > I have had to put a bound on the maximum integer size output of computations at 2^31 which of course is the maximum positive integer that 32-bit computers can handle. >> >> >> >> Would this not be 2^31 - 1? >> >> >> >> Also, how does your program respond when translated with -gnato? > >>Would this not be 2^31 - 1? - NO > > The max, POS integer is 2^(32-1) > Signed or unsigned integers ? > I understand the the max NEG integer is -[2^32-1)+1] > I think you understand incorrectly. The sign bit is a part of the 32 bit value so the range you can express is cut approx in half. Simon. -- Simon Clubley, clubley@remove_me.eisner.decus.org-Earth.UFP Microsoft: Bringing you 1980s technology to a 21st century world