Re: [patch] update function comments for lto_symtab_encoder_encode_*

[Richard Biener <richard.guenther@gmail.com>]

On Wed, Jan 14, 2015 at 5:58 PM, Aldy Hernandez <aldyh@redhat.com> wrote:
> On 01/14/2015 01:06 AM, Richard Biener wrote:
>
>>> Whenever I get to the LTO part of this project, I promise to start
>>> documenting things better.  This whole thing is a mystery.
>>
>>
>> Well - mostly to me as well ;)  I'll let Honza answer this...
>
>
> Ha, you're being too modest!  I get the feeling that no one wants to own up
> to LTO :).
>
> So...
>
> Would anyone mind if I removed all references of "WHOPR" in the
> documentation (doc/lto.texi) and in *most* of the comments in the source?
> AFAICT, WHOPR has been the default LTO mode since Richard's linker plugin
> patch here:
>
> https://gcc.gnu.org/ml/gcc-patches/2014-03/msg00157.html
>
> From what I can see, WHOPR is the default unless no partitions were found,
> but otherwise there is no way to disable it.  It's just confusing to have
> this nomenclature that is mostly not applicable.

You can disable WHOPR with -flto-partition=none, otherwise partitions
are always "found" (thus even if we identify only a single partition
we use a separate ltrans process).

> I obviously wouldn't change actual code, since we're past stage1, but
> comments/documentation are fair game.  Eventually, I'd like to change the
> code to something like "LTO partitioning mode" or something (at the next
> stage1).
>
> Would this be acceptable?

I'm not sure what you propose to change?  The references to "WHOPR"
may be historical (refering to the design document), and re-wording
the user-level and internals documentation to make it the default behavior
and maybe cite non-whopr mode as optimization in case of a single
partition is ok.

Note that we still have the issue that we want to exercise both
WHOPR and non-WHOPR in the testsuite but all testcases are so
small that we'd automagically would use non-WHOPR mode (if
such automatism was implemented...).

Richard.

> Aldy