[PATCH] Add PAREN_EXPR

[Richard Guenther]

On Tue, 19 Feb 2008, Tobias Burnus wrote:

> FX wrote:
> > >         * trans-expr.c (gfc_conv_expr_op): Expand INTRINSIC_PARENTHESES
> > >         as unary PAREN_EXPR for real and complex typed expressions.
> > >         * options.c (gfc_init_options): Enable flag_associative_math if
> > >         it isn't disabled automatically.
> > >
> > >         * gfortran.dg/reassoc_1.f90: New testcase.
> > >         * gfortran.dg/reassoc_2.f90: Likewise.
> > >     
> > Fortran part is OK. Thanks!
> >   
> Thanks also from me. Is it possible to add a flag for disabling the
> PAREN_EXPR? I'm sure some users want to have this to gain some speed. (For
> a/(b*c) the () are often only used because it is easier to read than a/b/c;
> for such programs it might be useful to be able to disable it.)
> 
> (ifort has such an option: -assume noprotect_parens; unfortunately it is
> enabled by default.)

Sure, I think this should be done by the frontend though as we might
want to use PAREN_EXPR internally in the middle-end where it is critical
for correctness (like expanding lround to (long)((x + 2e52) - 2e52) or
similar things).

Richard.