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From: Mark Mitchell <mark@codesourcery.com>
To: Michael Matz <matz@suse.de>
Cc: Richard Guenther <richard.guenther@gmail.com>,
	 Mike Stump <mikestump@comcast.net>,
	Nathan Sidwell <nathan@codesourcery.com>,
	 GCC Patches <gcc-patches@gcc.gnu.org>
Subject: Re: [gimple] assignments to volatile
Date: Sat, 26 Jun 2010 19:57:00 -0000	[thread overview]
Message-ID: <4C263A61.1040704@codesourcery.com> (raw)
In-Reply-To: <Pine.LNX.4.64.1006261912420.18619@wotan.suse.de>

Michael Matz wrote:

> Trying 3.3, and this testcase:

Thanks for doing this research!

Would you be willing to make a Wiki page with this information on it?

I think if we can fill in a table showing which compilers do what, that
would be extremely helpful.  If we had each of the examples you
collected in rows, and columns showing whether each compiler reads the
volatile variable, we could see just how much consensus there is.

> ICC 11.0 and 11.1 only generate a read of vobj5 (i.e. no re-reading occurs 
> at all) for the C language, and no read at all for the C++ language.

That's interesting.  Of course, ICC is not terribly heavily used as an
embedded compiler, which is where there is the most use of volatile.
(Of course, volatile is used in multi-threaded non-embedded programs as
well, though there the exact number of reads/writes is probably less
important to many users.)

Thanks,

-- 
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713

  reply	other threads:[~2010-06-26 17:35 UTC|newest]

Thread overview: 81+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-06-21 12:44 Nathan Sidwell
2010-06-21 13:26 ` Richard Guenther
2010-06-21 13:55   ` Michael Matz
2010-06-21 14:07     ` Richard Guenther
2010-06-21 14:09     ` Nathan Sidwell
2010-06-21 14:17       ` Michael Matz
2010-06-21 14:19         ` Richard Guenther
2010-06-21 14:53           ` Michael Matz
2010-06-21 14:17     ` IainS
2010-06-21 14:24       ` Michael Matz
2010-06-21 14:50         ` Nathan Sidwell
2010-06-21 15:24           ` Michael Matz
2010-06-22 11:36             ` Dave Korn
2010-06-23 20:16             ` Mike Stump
2010-06-24 11:51               ` Michael Matz
2010-06-21 15:24         ` Nathan Sidwell
2010-06-21 15:46           ` Michael Matz
2010-06-22 15:37     ` Mark Mitchell
2010-06-22 15:37       ` Jakub Jelinek
2010-06-22 15:57         ` Paul Koning
2010-06-22 15:47       ` Michael Matz
2010-06-22 15:58         ` Mark Mitchell
2010-06-23 11:38           ` Nathan Sidwell
2010-06-23 14:05             ` Mark Mitchell
2010-06-23 14:06               ` Michael Matz
2010-06-23 16:00                 ` Richard Guenther
2010-06-23 16:25               ` Paul Koning
2010-06-23 17:13                 ` Mark Mitchell
2010-06-23 19:16               ` Mike Stump
2010-06-24 10:22                 ` Mark Mitchell
2010-06-24 15:53                   ` Mike Stump
2010-06-24 16:00                     ` Mark Mitchell
2010-06-24 19:37                       ` Mike Stump
2010-06-25  9:37                         ` Nathan Sidwell
2010-06-25 19:06                           ` Mike Stump
2010-06-25 21:33                             ` Mark Mitchell
2010-06-26  9:35                               ` Mike Stump
2010-06-26 10:18                                 ` Mark Mitchell
2010-06-26 12:18                                   ` Richard Guenther
2010-06-26 19:52                                     ` Michael Matz
2010-06-26 19:57                                       ` Mark Mitchell [this message]
2010-06-26 20:08                                         ` Michael Matz
2010-06-26 22:13                                           ` Mark Mitchell
2010-06-28  9:20                                             ` Nathan Sidwell
2010-06-28  9:27                                               ` Nathan Sidwell
2010-06-26 10:20                                 ` Richard Kenner
2010-06-28  9:52                             ` Nathan Sidwell
2010-06-30 22:52                               ` Mike Stump
2010-07-05  8:59                                 ` Nathan Sidwell
2010-07-09  5:27                                   ` Mike Stump
2010-07-09  7:22                                     ` Nathan Sidwell
2010-07-16  8:10                                       ` Nathan Sidwell
2010-07-16 15:20                                         ` Mark Mitchell
2010-07-19  8:41                                           ` Nathan Sidwell
2010-08-13  9:56                                           ` Nathan Sidwell
2010-08-18 15:32                                             ` Mark Mitchell
2010-08-18 16:18                                               ` Richard Guenther
2010-08-18 18:04                                                 ` Mike Stump
2010-08-19 11:11                                               ` Nathan Sidwell
2010-08-20  4:22                                                 ` Mark Mitchell
2010-08-20 16:59                                                   ` Mike Stump
2010-08-20 18:00                                             ` H.J. Lu
2010-08-20 18:33                                               ` Nathan Sidwell
2010-06-25  9:20                       ` Nathan Sidwell
2010-06-24 10:23                 ` Nathan Sidwell
2010-06-24 17:05                   ` Mike Stump
2010-06-24 17:29                     ` Paul Koning
2010-06-25  9:26                     ` Nathan Sidwell
2010-06-25 18:20                       ` Mike Stump
2010-06-28  8:49                         ` Nathan Sidwell
2010-07-01  1:02                           ` Mike Stump
2010-07-05  9:02                             ` Nathan Sidwell
2010-07-09  5:14                               ` Mike Stump
2010-07-09  7:20                                 ` Nathan Sidwell
2010-06-22 15:56       ` Paul Koning
2010-06-22 12:08   ` Nathan Sidwell
2010-06-22 12:25     ` Richard Guenther
2010-06-22 13:12     ` Michael Matz
2010-06-22 13:54       ` Nathan Sidwell
2010-06-22 15:21         ` Michael Matz
2010-06-22 16:12           ` Joseph S. Myers

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