Re: New post-LTO OpenACC pass

[Bernd Schmidt <bschmidt@redhat.com>]

On 09/23/2015 02:14 PM, Nathan Sidwell wrote:
> On 09/23/15 06:59, Bernd Schmidt wrote:
>> On 09/22/2015 05:16 PM, Nathan Sidwell wrote:
>>> +    if (gimple_call_builtin_p (call, BUILT_IN_ACC_ON_DEVICE))
>>> +      /* acc_on_device must be evaluated at compile time for
>>> +         constant arguments.  */
>>> +      {
>>> +        oacc_xform_on_device (call);
>>> +        rescan = true;
>>> +      }
>>
>> Is there a reason this is not done as part of pass_fold_builtins? (It
>> looks like
>> maybe adding this to fold_call_stmt in builtins.c would be sufficient
>> too).
>
> Perhaps it could be.  I'll need to check where  that pass happens.
> Anyway, the main thrust of this patch is the new pass, which I thought
> might be easier to review with minimal additional  clutter.

There's no issue adding a new pass if there's a demonstrated need for 
it, but I think builtin folding doesn't quite meet that criterion given 
that we already have a pass that does that. Unless you really need it to 
happen very early in the pipeline - fold_builtins runs pretty late, but 
I checked and fold_call_stmt gets called from pass_forwprop and possibly 
from elsewhere too.


Bernd