From: Joe Buck <jbuck@Synopsys.COM>
To: davem@redhat.com (David S. Miller)
Cc: mark@codesourcery.com, jason@cygnus.com,
martin@mira.isdn.cs.tu-berlin.de, egcs@egcs.cygnus.com
Subject: Re: Linux and aliasing?
Date: Wed, 30 Jun 1999 15:43:00 -0000 [thread overview]
Message-ID: <199906071629.JAA26620@atrus.synopsys.com> (raw)
Message-ID: <19990630154300.rbRUYP9f3ipdu2x_owfohQg6l6uYTnhpHTrARcicyG8@z> (raw)
In-Reply-To: <199906071545.IAA07099@pizda.davem.net>
David Miller writes:
> One issue which seems to not be mentioned explicitly, is that such a
> change is typically not of the "flag day" variety, which turning it on
> for the next release seems to imply.
>
> Other compiler vendors seem to have done it in two stages:
> 1) Ok, the strict aliasing is there, but not a default optimization,
> you have to enable it explicitly. But come next release it will be
> on by default and thus you have ample time to fixup your code.
> 2) It's on by default in this new subsequent release, we warned you.
I'm inclined to agree with you. This is why I suggested that it perhaps
shouldn't be the default for gcc-2.95. This is still a possibility (it's
a couple of lines of code at most to flip the default).
One question we don't really have data on is how many programs will break.
If it's only the Linux kernel and a couple of others, we can just use
-fno-strict-aliasing for the affected programs. If many programs are
affected, we don't want to break them all, causing massive inconvenience
to users and developers and damaging the reputation of egcs/gcc.
next prev parent reply other threads:[~1999-06-30 15:43 UTC|newest]
Thread overview: 218+ messages / expand[flat|nested] mbox.gz Atom feed top
1999-06-03 10:23 Chip Salzenberg
1999-06-03 10:37 ` mark
1999-06-03 11:26 ` David S. Miller
1999-06-03 12:03 ` mark
1999-06-03 12:25 ` David S. Miller
1999-06-03 20:06 ` craig
1999-06-03 23:03 ` Linus Torvalds
1999-06-03 23:45 ` mark
1999-06-04 0:04 ` Linus Torvalds
1999-06-04 1:08 ` Branko Cibej
1999-06-30 15:43 ` Branko Cibej
1999-06-04 1:24 ` Joe Buck
1999-06-04 1:50 ` Linus Torvalds
1999-06-04 5:46 ` craig
1999-06-04 7:22 ` burley (was Re: Linux and aliasing?) Mark Hahn
1999-06-04 8:16 ` craig
1999-06-30 15:43 ` craig
1999-06-30 15:43 ` Mark Hahn
1999-06-04 8:35 ` Linux and aliasing? Linus Torvalds
1999-06-04 10:04 ` Joe Buck
1999-06-04 10:22 ` Jeffrey A Law
1999-06-04 10:31 ` Joe Buck
1999-06-04 10:53 ` Jeffrey A Law
1999-06-30 15:43 ` Jeffrey A Law
1999-06-30 15:43 ` Joe Buck
1999-07-11 10:55 ` Jeffrey A Law
1999-07-31 23:33 ` Jeffrey A Law
1999-06-04 11:11 ` Toon Moene
1999-06-04 12:20 ` Jeffrey A Law
1999-06-05 5:45 ` Toon Moene
1999-06-05 6:23 ` Andi Kleen
1999-06-05 10:32 ` Toon Moene
1999-06-05 13:26 ` Jamie Lokier
1999-06-05 19:35 ` Linus Torvalds
1999-06-06 1:18 ` Martin v. Loewis
1999-06-06 10:46 ` Linus Torvalds
1999-06-30 15:43 ` Linus Torvalds
1999-06-06 17:56 ` Jason Merrill
1999-06-06 19:24 ` Tim Hollebeek
1999-06-30 15:43 ` Tim Hollebeek
1999-06-06 22:23 ` Jeffrey A Law
1999-06-30 15:43 ` Jeffrey A Law
[not found] ` <199906070645.IAA00615@mira.isdn.cs.tu-berlin.de>
1999-06-07 2:14 ` Jason Merrill
1999-06-07 8:02 ` mark
1999-06-07 8:41 ` David S. Miller
1999-06-07 9:24 ` Jeffrey A Law
1999-06-07 9:29 ` David S. Miller
1999-06-30 15:43 ` David S. Miller
1999-06-30 15:43 ` Jeffrey A Law
1999-06-07 9:32 ` Joe Buck [this message]
1999-06-30 15:43 ` Joe Buck
1999-06-30 15:43 ` David S. Miller
1999-06-30 15:43 ` mark
1999-06-07 13:11 ` Jeffrey A Law
1999-06-30 15:43 ` Jeffrey A Law
1999-06-30 15:43 ` Jason Merrill
1999-06-30 15:43 ` Jason Merrill
1999-06-30 15:43 ` Martin v. Loewis
1999-06-30 15:43 ` Linus Torvalds
1999-06-30 15:43 ` Jamie Lokier
1999-06-05 18:48 ` Linus Torvalds
1999-06-30 15:43 ` Linus Torvalds
1999-06-30 15:43 ` Toon Moene
1999-06-05 10:37 ` mark
1999-06-05 11:09 ` David S. Miller
1999-06-05 12:11 ` Toon Moene
1999-06-05 12:21 ` David S. Miller
1999-06-05 16:51 ` mark
1999-06-30 15:43 ` mark
1999-06-30 15:43 ` David S. Miller
1999-06-30 15:43 ` Toon Moene
1999-06-07 6:01 ` Joern Rennecke
1999-06-30 15:43 ` Joern Rennecke
1999-06-30 15:43 ` David S. Miller
1999-06-05 11:35 ` Andi Kleen
1999-06-30 15:43 ` Andi Kleen
1999-06-05 12:41 ` Jamie Lokier
1999-06-05 14:43 ` Martin v. Loewis
1999-06-30 15:43 ` Martin v. Loewis
1999-06-05 16:53 ` mark
1999-06-07 2:36 ` Jamie Lokier
1999-06-07 8:04 ` mark
1999-06-30 15:43 ` mark
1999-06-30 15:43 ` Jamie Lokier
1999-06-30 15:43 ` mark
1999-06-30 15:43 ` Jamie Lokier
1999-06-30 15:43 ` mark
1999-06-30 15:43 ` Andi Kleen
1999-06-06 23:12 ` f77 vs type based alias analysis Jeffrey A Law
1999-06-30 15:43 ` Jeffrey A Law
1999-06-06 23:20 ` Linux and aliasing? Jeffrey A Law
1999-06-30 15:43 ` Jeffrey A Law
1999-06-30 15:43 ` Toon Moene
1999-06-30 15:43 ` Jeffrey A Law
1999-06-05 4:05 ` Andi Kleen
1999-06-30 15:43 ` Andi Kleen
1999-06-30 15:43 ` Toon Moene
1999-06-30 15:43 ` Jeffrey A Law
1999-06-04 11:49 ` Linus Torvalds
1999-06-04 13:03 ` Gabriel Dos_Reis
1999-06-04 13:13 ` Joe Buck
1999-06-30 15:43 ` Joe Buck
1999-06-30 15:43 ` Gabriel Dos_Reis
1999-06-30 15:43 ` Linus Torvalds
1999-06-04 12:59 ` Alexandre Oliva
1999-06-04 13:29 ` Joe Buck
1999-06-04 13:39 ` Alexandre Oliva
1999-06-30 15:43 ` Alexandre Oliva
1999-06-30 15:43 ` Joe Buck
1999-06-30 15:43 ` Alexandre Oliva
1999-06-30 15:43 ` Joe Buck
1999-06-30 15:43 ` Linus Torvalds
1999-06-30 15:43 ` craig
1999-06-30 15:43 ` Linus Torvalds
1999-06-30 15:43 ` Joe Buck
1999-06-04 5:47 ` craig
1999-06-30 15:43 ` craig
1999-06-04 7:11 ` mark
1999-06-04 8:38 ` Linus Torvalds
1999-06-30 15:43 ` Linus Torvalds
1999-06-30 15:43 ` mark
1999-06-04 8:41 ` Tim Hollebeek
1999-06-04 8:53 ` Jeffrey A Law
1999-06-30 15:43 ` Jeffrey A Law
1999-06-30 15:43 ` Tim Hollebeek
1999-06-30 15:43 ` Linus Torvalds
1999-06-30 15:43 ` mark
1999-06-04 5:47 ` craig
1999-06-04 8:17 ` Linus Torvalds
1999-06-04 8:49 ` craig
1999-06-04 8:57 ` Linus Torvalds
1999-06-04 9:02 ` Jean-Pierre Radley
1999-06-30 15:43 ` Jean-Pierre Radley
1999-06-30 15:43 ` Linus Torvalds
1999-06-30 15:43 ` craig
1999-06-30 15:43 ` Linus Torvalds
1999-06-30 15:43 ` craig
1999-06-04 8:39 ` Tim Hollebeek
1999-06-04 8:55 ` Linus Torvalds
1999-06-04 15:20 ` Richard Henderson
1999-06-05 9:50 ` Linus Torvalds
1999-06-05 11:00 ` mark
1999-06-06 10:30 ` Linus Torvalds
1999-06-06 10:44 ` mark
1999-06-06 14:17 ` Linus Torvalds
1999-06-06 17:41 ` mark
1999-06-07 8:58 ` Linus Torvalds
1999-06-07 9:18 ` mark
1999-06-07 9:29 ` Linus Torvalds
1999-06-07 9:38 ` Tim Hollebeek
1999-06-07 10:05 ` Jamie Lokier
1999-06-30 15:43 ` Jamie Lokier
1999-06-07 10:44 ` Linus Torvalds
1999-06-07 11:22 ` Jeffrey A Law
1999-06-08 1:34 ` Nick Ing-Simmons
1999-06-08 1:48 ` Jeffrey A Law
1999-06-30 15:43 ` Jeffrey A Law
1999-06-30 15:43 ` Nick Ing-Simmons
1999-06-30 15:43 ` Jeffrey A Law
1999-06-30 15:43 ` Linus Torvalds
1999-06-30 15:43 ` Tim Hollebeek
1999-06-30 15:43 ` Linus Torvalds
1999-06-30 15:43 ` mark
1999-06-07 13:34 ` Jamie Lokier
1999-06-30 15:43 ` Jamie Lokier
1999-06-30 15:43 ` Linus Torvalds
1999-06-30 15:43 ` mark
1999-06-30 15:43 ` Linus Torvalds
1999-06-30 15:43 ` mark
1999-06-30 15:43 ` Linus Torvalds
1999-06-30 15:43 ` mark
1999-06-30 15:43 ` Linus Torvalds
1999-06-30 15:43 ` Richard Henderson
1999-06-30 15:43 ` Linus Torvalds
1999-06-30 15:43 ` Tim Hollebeek
1999-06-04 15:02 ` Richard Henderson
1999-06-04 16:50 ` Bernd Schmidt
1999-06-30 15:43 ` Bernd Schmidt
1999-06-05 9:35 ` Linus Torvalds
1999-06-05 13:34 ` Richard Henderson
1999-06-05 18:40 ` Linus Torvalds
1999-06-30 15:43 ` Linus Torvalds
1999-06-05 21:38 ` Jakub Jelinek
1999-06-30 15:43 ` Jakub Jelinek
1999-06-30 15:43 ` Richard Henderson
1999-06-30 15:43 ` Linus Torvalds
1999-06-30 15:43 ` Richard Henderson
1999-06-30 15:43 ` Linus Torvalds
1999-06-03 23:53 ` Martin v. Loewis
1999-06-30 15:43 ` Martin v. Loewis
[not found] ` <v04205101b37d700fbf8d@[192.168.1.254]>
1999-06-04 7:01 ` craig
1999-06-30 15:43 ` craig
1999-06-30 15:43 ` craig
1999-06-30 15:43 ` David S. Miller
1999-06-03 13:31 ` Andi Kleen
1999-06-30 15:43 ` Andi Kleen
1999-06-30 15:43 ` mark
1999-06-30 15:43 ` David S. Miller
1999-06-03 12:02 ` Andi Kleen
1999-06-03 15:38 ` Martin v. Loewis
1999-06-30 15:43 ` Martin v. Loewis
1999-06-30 15:43 ` Andi Kleen
1999-06-30 15:43 ` mark
1999-06-30 15:43 ` Chip Salzenberg
1999-06-04 11:54 Mike Stump
1999-06-04 12:13 ` Jeffrey A Law
1999-06-04 13:25 ` Sylvain Pion
1999-06-04 13:32 ` Jeffrey A Law
1999-06-30 15:43 ` Jeffrey A Law
1999-06-30 15:43 ` Sylvain Pion
1999-06-30 15:43 ` Jeffrey A Law
1999-06-30 15:43 ` Mike Stump
1999-06-06 15:08 Ross Harvey
1999-06-06 15:46 ` Linus Torvalds
1999-06-30 15:43 ` Linus Torvalds
1999-06-06 17:29 ` David S. Miller
1999-06-30 15:43 ` David S. Miller
1999-06-30 15:43 ` Ross Harvey
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