This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: type based aliasing again
- To: jbuck@synopsys.com (Joe Buck)
- Subject: Re: type based aliasing again
- From: Joe Buck <jbuck@synopsys.COM>
- Date: Wed, 8 Sep 99 20:42:51 PDT
- Cc: gcc@gcc.gnu.org, rms@gnu.org
I made an oops:
> As of gcc 2.95, optimizations that take advantage of this rule are turned
> on by default. The problem is that there is a good deal of
> technically-invalid code out there (that, for example, reads and writes
> long data as pairs of shorts, without using unions). gcc 2.95 may
> malfunction on such code unless the flag -fno-strict-aliasing is provided.
As has been pointed out to me, "malfunction" implies a compiler bug,
while the bug is in the invalid code. I hope that this didn't cause
any confusion; I know of no bugs in the type-based aliasing code.