This is the mail archive of the gcc-bugs@gcc.gnu.org mailing list for the GCC project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: gcc 4.0.0 on amd64: problem with -O2?

From: Andrew Pinski <pinskia at physics dot uc dot edu>
To: Harald Dunkel <harald dot dunkel at t-online dot de>
Cc: gcc-bugs at gcc dot gnu dot org, aj at andaco dot de
Date: Sat, 7 May 2005 15:31:52 -0400
Subject: Re: gcc 4.0.0 on amd64: problem with -O2?
References: <427D0339.7030904@t-online.de> <680cf3ff627ea4ce82861a8253bb08b7@physics.uc.edu> <427D1619.3070705@t-online.de>

On May 7, 2005, at 3:25 PM, Harald Dunkel wrote:

Andrew Pinski wrote:


Stop right there, you said it warns, well this is a case where
you are violating C89/C99/C++ aliasing rules so it is a bug in your
code and not in GCC.


This is not my code. It is XFree86 4.3. I am just trying to
help by investigating a problem and providing an easy testcase.

If you read my report, then you will recognize that it is
a problem of the optimizer.


Wrong, try again.  Violating aliasing rules cause undefined behavior
so seg faulting is an okay thing to do.

-- Pinski

Follow-Ups:
- Re: gcc 4.0.0 on amd64: problem with -O2?
  - From: Harald Dunkel

References:
- gcc 4.0.0 on amd64: problem with -O2?
  - From: Harald Dunkel
- Re: gcc 4.0.0 on amd64: problem with -O2?
  - From: Andrew Pinski
- Re: gcc 4.0.0 on amd64: problem with -O2?
  - From: Harald Dunkel

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]