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,ecc38b3271b36b88 X-Google-NewGroupId: yes X-Google-Attributes: gida07f3367d7,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news1.google.com!news2.google.com!news.glorb.com!xmission!newsswitch.lcs.mit.edu!nntp.TheWorld.com!not-for-mail From: Robert A Duff Newsgroups: comp.lang.ada Subject: Re: What is the warning about builtin-function on gcc-4.6.0 ? Date: Tue, 29 Mar 2011 14:35:27 -0400 Organization: The World Public Access UNIX, Brookline, MA Message-ID: References: <87aagiclte.fsf@mid.deneb.enyo.de> <475d10ca-5d4e-490c-9b88-e12cd3cd3faa@b13g2000prf.googlegroups.com> <87d3lejjyv.fsf@mid.deneb.enyo.de> <6c748f70-7e75-49b4-a467-d1d2d6b24323@w9g2000prg.googlegroups.com> <87k4flhoeg.fsf@mid.deneb.enyo.de> <8762r5hl2u.fsf@mid.deneb.enyo.de> <87vcz5ot5z.fsf@mid.deneb.enyo.de> <87sju8lcis.fsf@mid.deneb.enyo.de> NNTP-Posting-Host: shell01.theworld.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: pcls6.std.com 1301423727 7064 192.74.137.71 (29 Mar 2011 18:35:27 GMT) X-Complaints-To: abuse@TheWorld.com NNTP-Posting-Date: Tue, 29 Mar 2011 18:35:27 +0000 (UTC) User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.3 (irix) Cancel-Lock: sha1:xMi0qHkv5Qf0q2II0Lhw+R3RGhI= Xref: g2news1.google.com comp.lang.ada:18582 Date: 2011-03-29T14:35:27-04:00 List-Id: "Randy Brukardt" writes: > "Robert A Duff" wrote in message > news:wccsju8fptr.fsf@shell01.TheWorld.com... >> But "EQUAL (ABS I, I)" can return False. The test calls FAILED >> (twice) if it does, so the test is wrong. > > Doesn't that depend on the implementation of EQUAL? It's just a function > call, it doesn't necessarily have the same semantics as "=". (I think the > intent is that the result is the same as "=" for valid values, but I doubt > anything is guaranteed about invalid values.) > > The actual implementation of EQUAL is full of recursion (it's intended to be > an optimization blocker), and it's hard to tell whether or not one of the > inner calls would cause some other results for invalid values (such as > raising Constraint_Error). > > And if it didn't do that, the implementor could change the function to > include 'Valid on the operands to ensure that they're not invalid. Sure, EQUAL can raise C_E on invalid values. But I don't think it can return True for invalid values that are not mathematically equal. (If it can, I think it's a mistake in the REPORT package.) I'm too lazy to inspect it right now. Has EQUAL changed since Ada 83 days? Just curious. > I suspect that there are lot of tests that might fail if the rules for valid > values are taken to the limit -- any test that intentionally raises an > exception is always at risk for optimization problems (and that is what > 13.9.1 is ultimately about). Yes, and I'll bet an agressive implementation of 11.6 would find some wrong ACATS tests. - Bob