[PATCH] Add PAREN_EXPR

[Tobias Burnus]

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.)

Tobias