Re: [OpenACC] declare directive

[James Norris <jnorris@codesourcery.com>]

Jakub,

On 11/06/2015 01:22 PM, Jakub Jelinek wrote:
> On Fri, Nov 06, 2015 at 08:03:52PM +0100, Jakub Jelinek wrote:
>> What exactly do you want to achieve?  Why do you record it
>> in gimplify_omp_ctx, but then only look at it in gimplify_body?
>> The way you abuse gimplify_omp_ctx for that is just too ugly.
>> All the gimplification code expects that when you enter some OpenMP/OpenACC
>> construct, you create new context if it needs one, then process the body
>> of the construct, then pop it up.  The declare_returns stuff
>> violates all of this.  Do you want to enqueue all the statements
>> at the end of the body?  Then just stick it into some gimple_seq
>> outside of the gimplify_omp_ctx, and process in there.  Or if you
>> want to process it when leaving some construct, arrange for that.
> If the unmap operation is supposed to sit where the corresponding variable
> goes out of scope, supposedly you would need to find out in which bind
> (gimplify_ctx (not omp!)) the variable is declared and arrange for the
> statement to be added as a cleanup of that region.
> If you queue everything to the end of function, I'm afraid with e.g.
> void foo (void)
> {
>    {
>      char buf[2048];
>      #acc declare whatever(buf)
>      // ...
>    }
>    {
>      char buf2[2048];
>      #acc declare whatever(buf2)
>      // ...
>    }
> }
> both vars will be assigned overlapping ranges and you might run into
> trouble trying to map buf2 while buf is still mapped.
>
> 	Jakub

Good point.

Thank you again,
Jim