http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50960
--- Comment #14 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-11-03 14:17:52 UTC --- (In reply to comment #13) > Patch for the issue of comment 5: Constants (PARAMETER) which are exists as > global static variables were not marked as TREE_READONLY. > > With the patch below (not regtested), the function call is optimized away in: > > module m > integer, parameter :: PARA(*) = [1,2,3,4,5,6,7,8,9,10] > end module m > > subroutine test() > use m > integer :: i > i = 1 > if (para(i) /= 1) call I_am_optimized_away() > end > > > --- a/gcc/fortran/trans-decl.c > +++ b/gcc/fortran/trans-decl.c > @@ -517,6 +517,9 @@ gfc_finish_var_decl (tree decl, gfc_symbol * sym) > /* If it wasn't used we wouldn't be getting it. */ > TREE_USED (decl) = 1; > > + if (sym->attr.flavor == FL_PARAMETER) > + TREE_READONLY (decl) = 1; > + > /* Chain this decl to the pending declarations. Don't do pushdecl() > because this would add them to the current scope rather than the > function scope. */ Yes, that should work iff Fortran does not allow parameter initializers that require runtime init (like / foo() /, thus a function call result).
