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From: "fw at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/67999] Wrong optimization of pointer comparisons
Date: Mon, 19 Oct 2015 08:26:00 -0000	[thread overview]
Message-ID: <bug-67999-4-HxPv381tUI@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-67999-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67999

--- Comment #8 from Florian Weimer <fw at gcc dot gnu.org> ---
(In reply to Alexander Cherepanov from comment #4)

> Am I right that the C standards do not allow for such a limitation (and
> hence this should not be reported to glibc as a bug) and gcc is not
> standards-compliant in this regard? Or I'm missing something?

The standard explicitly acknowledges the possibility of arrays that have more
than PTRDIFF_MAX elements (it says that the difference of two pointers within
the same array is not necessarily representable in ptrdiff_t).

I'm hesitant to put in artificial limits into glibc because in the mast, there
was significant demand for huge mappings in 32-bit programs (to the degree that
Red Hat even shipped special kernels for this purpose).


  parent reply	other threads:[~2015-10-19  8:26 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <bug-67999-4@http.gcc.gnu.org/bugzilla/>
2015-10-17  8:03 ` glisse at gcc dot gnu.org
2015-10-17  8:14 ` pinskia at gcc dot gnu.org
2015-10-17  8:35 ` schwab@linux-m68k.org
2015-10-17 12:52 ` ch3root at openwall dot com
2015-10-19  2:30 ` danielmicay at gmail dot com
2015-10-19  5:36 ` bugdal at aerifal dot cx
2015-10-19  8:17 ` fw at gcc dot gnu.org
2015-10-19  8:26 ` fw at gcc dot gnu.org [this message]
2015-10-19  8:41 ` danielmicay at gmail dot com
2015-10-19  8:47 ` danielmicay at gmail dot com
2015-10-19  9:05 ` fw at gcc dot gnu.org
2015-10-19  9:09 ` fw at gcc dot gnu.org
2015-10-19  9:12 ` danielmicay at gmail dot com
2015-10-19  9:26 ` danielmicay at gmail dot com
2015-10-19  9:55 ` danielmicay at gmail dot com
2015-10-19  9:56 ` rguenth at gcc dot gnu.org
2015-10-19 10:12 ` jakub at gcc dot gnu.org
2015-10-21  2:09 ` ch3root at openwall dot com
2015-10-21  2:18 ` ch3root at openwall dot com
2015-10-21  3:21 ` danielmicay at gmail dot com
2015-10-28  0:12 ` joseph at codesourcery dot com
2015-10-28  0:20 ` bugdal at aerifal dot cx
2015-10-28  2:29 ` joseph at codesourcery dot com
2015-10-28 18:26 ` ch3root at openwall dot com

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