[m-dev.] questions about grades

[Julien Fischer]

Hi Zoltan,

Peter has already answered your other questsion.

On Tue, 23 Feb 2016, Zoltan Somogyi wrote:

> The version of the grade we use for link-time consistency checks records
> the number of tag bits we use, together with whether we use low primary tags
> (the default), high primary tags, or neither, but the user visible grades
> do not: instead, we always use low tags with 3 tags bits if available
> (except with .pregen), and 2 tag bits if the third is not available.
>
> I would also like to know what constraints govern the use of the .regparm
> grade component (which is applicable only when targeting high level C).
> Does anyone know? Does anyone ever use .regparm in any way other than
> via autoconfiguration?

The only way to use it is to manually set:

     CFLAGS = -DMR_USE_REGPARM

Other than that, it isn't used.  It's not something that (currently) appears in
user visible grades in any case.

...

> Do I understand correctly that the .picreg grade component is not intended
> to be specified as part of a grade, but is rather intended to be specified
> only via an autoconfigured set of extra C #defines when generating object files
> that are intended to go into shared libraries? This set of #defines may
> be empty (on platforms on which nothing special needs to be done to compile
> code into shared libraries), or not. Am I right in believing that while
> we may need the picreg grade component in the grade we use for our link-time
> grade consisteny check, we never need to include it in any user-visible grade?

Correct.

Julien.