Re: changing "configure" to default to "gcc -g -O2 -fwrapv ..."

[Andrew Pinski]

> 
> Gabriel Dos Reis wrote:
> 
> > I have been looking into infer_loop_bounds_from_signedness() called
> > from infer_loop_bounds_from_undefined().
> > At some places, nowrap_type_p() is used but this function operates
> > only on types, so there will be too many false positive there; yet we
> > will miss warning through that case.
> 
> My inclination is to skip the warning for the loop
> induction variable case. I think this will generate
> lots of false positives, and almost no useful
> warnings (I still think this is the one and only
> case where the undefined optimization should be done,
> in fact I think it would be useful to have a switch
> that says
> 
> -fwrapv-in-all-cases-except-loop-bounds


Again, please don't this the default for Fortran as integer
overflow has been undefined since at least 1977 so I don't think
it is a good idea for GCC in general anyways as evidence of Fortran.

-- Pinski