[22.2/32] module flags

[Nathan Sidwell]

On 11/13/20 9:27 AM, Richard Biener wrote:
> On Fri, Nov 13, 2020 at 3:04 PM Nathan Sidwell <nathan@acm.org> wrote:
>>

>   struct GTY(()) lang_decl_base {
> -  /* Larger than necessary for faster access.  */
> -  ENUM_BITFIELD(lang_decl_selector) selector : 16;
> +  ENUM_BITFIELD(lang_decl_selector) selector : 3;
> ...
> +  unsigned attached_decls_p : 1;
> +
> +  /* 10 spare bits.  */
> 
> so for "faster access' you could still make selector 8 bits, reducing
> spare bits to 5.

could do -- we always know what kind of lang_decl to expect from the 
originating tree's code.  It's only for the garbage collector that we 
need the selector. (+ the checkers)
> Can you add comments (like on some other bits var / fn / type)
> what kind of decls the new bits are used on?  Maybe some
> bits can be overloaded if spare bits are needed.

sure.  For the record it's VAR_DECL, TYPE_DECL, FUNCTION_DECL, 
CONCEPT_DECL, TEMPLATE_DECL, NAMESPACE_DECL (that's to many for a 
TREE_CHECK, we only go to 5).

> 
> Thanks,
> Richard.
> 
>> nathan
>>
>> --
>> Nathan Sidwell


-- 
Nathan Sidwell