This is the mail archive of the gcc@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]

Re: Proposal: -O4 -> strict-aliasing

To: nbecker at fred dot net
Subject: Re: Proposal: -O4 -> strict-aliasing
From: Mark Mitchell <mark at codesourcery dot com>
Date: Thu, 28 Oct 1999 08:20:14 -0700
Cc: gcc at gcc dot gnu dot org
Organization: CodeSourcery, LLC
References: <x88emei5n4d.fsf@rpppc2.hns.com><19991026085631W.mitchell@codesourcery.com><x88d7tzbr7o.fsf@rpppc2.hns.com>


>>>>> "Mark" == Mark Mitchell <mark@codesourcery.com> writes:

  4) potentially dangerous opt

But I don't think we should encourage people to think of
-fstrict-aliasing this way.  As we've discussed, lots of previous
optimizations broke code that "always worked" before.

It's OK that we've disabled -fstrict-aliasing by default; hopefully,
at some point, it will be culturally acceptable to turn it back on.
But, when we do, it should be at O2, not at something beyond O3.  It's
an:

  2) extensive/expensive opt

--
Mark Mitchell                   mark@codesourcery.com
CodeSourcery, LLC               http://www.codesourcery.com

References:
- Proposal: -O4 -> strict-aliasing
  - From: nbecker
- Re: Proposal: -O4 -> strict-aliasing
  - From: Mark Mitchell
- Re: Proposal: -O4 -> strict-aliasing
  - From: nbecker

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