public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "johnvb at broadcom dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/51709] armv7 target is not using unaligned access to packed fields sometimes (halfwords, loads?)
Date: Fri, 13 Jan 2012 18:59:00 -0000	[thread overview]
Message-ID: <bug-51709-4-baCfdfs8Bi@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-51709-4@http.gcc.gnu.org/bugzilla/>

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51709

--- Comment #5 from John A. Van Boxtel <johnvb at broadcom dot com> 2012-01-13 18:39:43 UTC ---
Sorry about not understanding CS vs GNU release numbering and time
relationship.  I now understand that CS versions may precede introduction into
the GNC source.  I will also try to work with CS on reporting the bug.

I noticed this bug was listed as a code generation enhancement which I could
understand in a strict sense, i.e. the code generated works.  But given that
the compiler does create unaligned access to half words sometimes and in armv7,
there is no unaligned restrictions on normal half (or full) word access, this
seems like a significant code geneation issue for armv7 and makes one wonder if
the root cause might be more serious.

Constrast this with an architecture like x86 where unaligned access has always
been legal but if somehow the code generator used byte acesses, shifts and
and/or's to access (half) words.  This would be view as pretty "buggy".

Bottom line: I am just trying to make sure that the "enhancement" attribute
doesn't disqualify this from the current release cycle.  From that point of
view this seems like a bug to be fixed, not a future enhancement request.

Regards,

John A. Van Boxtel


      parent reply	other threads:[~2012-01-13 18:40 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-12-30  2:27 [Bug target/51709] New: " johnvb at broadcom dot com
2011-12-30  2:28 ` [Bug target/51709] " johnvb at broadcom dot com
2011-12-30  2:28 ` johnvb at broadcom dot com
2011-12-30  3:24 ` johnvb at broadcom dot com
2012-01-13 15:41 ` ramana at gcc dot gnu.org
2012-01-13 18:59 ` johnvb at broadcom dot com [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=bug-51709-4-baCfdfs8Bi@http.gcc.gnu.org/bugzilla/ \
    --to=gcc-bugzilla@gcc.gnu.org \
    --cc=gcc-bugs@gcc.gnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).