> > "Daniel Berlin" <[EMAIL PROTECTED]> writes: > > > Just to address the other compiler issue > >> > >> No, they will work on other compilers, since 'configure' > >> won't use -O2 with those other compilers. > > > > icc defaults to -O2 without any options, so unless you are passing > > -O0, it will enable this. > > Thanks, I didn't know that (I don't use icc). > > If -O0 is the only way to convince icc to give us wraparound > arithmetic, then I guess we'll have to default to -O0 for icc.
What about XYZCC? I don't see why defaulting to -O0 for ICC will help here at all. You are just giving up on the undefined issue instead of fixing it in the source. I gave a way how to do this loop in a portable way and I have not got comments back from you saying it is a good idea or not. Since there the way you define the loop right now is not portable at all given Daniel's comments about both ICC and XLC, I don't see why you are trying to hide the issue. I don't see why we are getting away from the real issue of autoconf depending on undefined behavior code that might be miscompiled with any compiler, might not be GCC but could any? Here at Sony, we get reports about aliasing issues and we actually help the developers fix their code so it is portable and works correctly. In fact recently I have been asked about aliasing issues in code even if GCC did not create the "wrong" code yet. The developer was able to fix his code before he even started to compile the code. Thanks, Andrew Pinski
