From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="iso-8859-1" From: "Kevin B. Hendricks" To: Franz Sirl Subject: Re: asm inline Date: Mon, 2 Dec 2002 10:11:55 -0500 Cc: Andreas Schwab , linuxppc-dev@lists.linuxppc.org References: <5.2.0.9.2.20021202154112.0512a008@mail.lauterbach.com> In-Reply-To: <5.2.0.9.2.20021202154112.0512a008@mail.lauterbach.com> MIME-Version: 1.0 Message-Id: <200212021011.55105.kevin.hendricks@sympatico.ca> Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: Hi, Here is what Sun's Hamburg developers wrote in reply... > Hi Kevin, > > -fstrict-aliasing is in -O2 optimization since gcc-3.0.x. And no, our > code is not strict alias safe. You'll get some problems, I know of at > least one place in sc. I bet there are more. > > I recommend to use -O2 -fno-strict-aliasing. This is what Hamburg > release engineering currently uses. > > If someone is able to identify all strict alias violating places I would > be more than happy to propose that we change these (or add the > -fno-strict-alias to just these files). > > Heiner So it looks like Solaris and Win must not detect these issues already. So a backport of the gcc 3.3 warning flag would certainly be a big help to the OOo project as well. Thanks, Kevin On December 2, 2002 09:51, Franz Sirl wrote: > At 15:37 02.12.2002, Kevin B. Hendricks wrote: > >Hi, > > > > > |> Is there any warning flag that can be enabled to help find these > > > |> cases (the OOo source base is simply huge)? > > > > > > gcc 3.3 implements such a warning, but it may give many false > > > positives. > > > >Any chance we can get this flag backported so that it appears in gcc > > 3.2.2? > > > >False positives are a whole lot better than code that quietly does the > > an unexpected thing. > > Well, are you sure OO is really affected? strict-aliasing is the default > since gcc-2.96 which means that everything since redhat-7.0 would be > affected on x86 for example. Also GCC has been very late to make this > the default at all, I think that Sun and MS compilers do this for years > already. I would be very surprised if a multiplatform project like OO > still contained reasonable amounts of aliasing-unsafe code. > > Franz. > > ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/