Re: gothic_moth, codlin_moth failures on REL8_2_STABLE

Tom Lane píše v čt 11. 03. 2010 v 11:37 -0500:
> Zdenek Kotala <Zdenek(dot)Kotala(at)Sun(dot)COM> writes:
> > "-xO4 -xalias_level=basic" generates problem.
> > "-xO3 -xalias_level=basic" works fine
> > "-xO5" works fine
>
> > As documentation say:
>
> > Cite from Sun studio compiler guide:
> > http://docs.sun.com/app/docs/doc/819-5265/bjapp?a=view
>
> > xalias_level=basic
> > ------------------
> > If you use the -xalias_level=basic option, the compiler assumes that
> > memory references that involve different C basic types do not alias each
> > other. The compiler also assumes that references to all other types can
> > alias each other as well as any C basic type. The compiler assumes that
> > references using char * can alias any other type.
>
> > For example, at the -xalias_level=basic level, the compiler assumes that
> > a pointer variable of type int * is not going to access a float object.
> > Therefore it is safe for the compiler to perform optimizations that
> > assume a pointer of type float * will not alias the same memory that is
> > referenced with a pointer of type int *.
>
> I think you need to turn that off. On gcc we use -fno-strict-aliasing
> which disables the type of compiler assumption that this is talking about.
> I'm not sure exactly how that might create the specific failure we are
> seeing here, but I can point you to lots and lots of places in the
> sources where such an assumption would break things.

Reconfigured and both animal are green.

Zdenek