Re: [PATCH 2/6, OpenACC, libgomp] Async re-work, oacc-* parts

[Chung-Lin Tang <chunglin_tang at mentor dot com>]

On 2018/12/14 10:17 PM, Thomas Schwinge wrote:
> Hi Chung-Lin!
>
> On Tue, 25 Sep 2018 21:10:47 +0800, Chung-Lin Tang <chunglin_tang@mentor.com> wrote:
> > --- a/libgomp/oacc-async.c
> > +++ b/libgomp/oacc-async.c
>
> > +attribute_hidden struct goacc_asyncqueue *
> > +lookup_goacc_asyncqueue (struct goacc_thread *thr, bool create, int async)
> > +{
> > +  /* The special value acc_async_noval (-1) maps to the thread-specific
> > +     default async stream.  */
> > +  if (async == acc_async_noval)
> > +    async = thr->default_async;
> > +
> > +  if (async == acc_async_sync)
> > +    return NULL;
> > +
> > +  if (async < 0)
> > +    gomp_fatal ("bad async %d", async);
>
> To make this "resolve" part more obvious, that is, the translation from
> the "async" argument to an "asyncqueue" array index:
>
> > +  if (!create
> > +      && (async >= dev->openacc.async.nasyncqueue
> > +	  || !dev->openacc.async.asyncqueue[async]))
> > +    return NULL;
> > +[...]
>
> ..., I propose adding a "async2id" function for that, and then rename all
> "asyncqueue[async]" to "asyncqueue[id]".

I don't think this is needed. This is the only place in the entire runtime that
does asyncqueue indexing, adding more conceptual layers of re-directed indexing
seems unneeded.

I do think the more descriptive comments are nice though.

> And, this also restores the current trunk behavior, so that
> "acc_async_noval" gets its own, separate "asyncqueue".

Is there a reason we need to restore that behavior right now?

Thanks,
Chung-Lin