Re: [PATCH] Pass manager: add support for termination of pass list

[Richard Biener <richard dot guenther at gmail dot com>]

On Wed, Nov 4, 2015 at 11:38 AM, Martin LiÅka <mliska@suse.cz> wrote:
> On 11/03/2015 03:44 PM, Richard Biener wrote:
>> On Tue, Nov 3, 2015 at 3:13 PM, Martin LiÅka <mliska@suse.cz> wrote:
>>> On 11/03/2015 02:46 PM, Richard Biener wrote:
>>>> On Fri, Oct 30, 2015 at 1:53 PM, Martin LiÅka <mliska@suse.cz> wrote:
>>>>> On 10/30/2015 01:13 PM, Richard Biener wrote:
>>>>>> So I suggest to do the push/pop of cfun there.
>>>>>> do_per_function_toporder can be made static btw.
>>>>>>
>>>>>> Richard.
>>>>>
>>>>> Right, I've done that and it works (bootstrap has been currently running),
>>>>> feasible for HSA branch too.
>>>>>
>>>>> tree-pass.h:
>>>>>
>>>>> /* Declare for plugins.  */
>>>>> extern void do_per_function_toporder (void (*) (function *, void *), void *);
>>>>>
>>>>> Attaching the patch that I'm going to test.
>>>>
>>>> Err.
>>>>
>>>> +      cgraph_node::get (current_function_decl)->release_body ();
>>>> +
>>>> +      current_function_decl = NULL;
>>>> +      set_cfun (NULL);
>>>>
>>>> I'd have expected
>>>>
>>>>       tree fn = cfun->decl;
>>>>       pop_cfun ();
>>>>       gcc_assert (!cfun);
>>>>       cgraph_node::get (fn)->release_body ();
>>>>
>>>> here.
>>>
>>> Yeah, that works, but we have to add following hunk:
>>>
>>> diff --git a/gcc/function.c b/gcc/function.c
>>> index aaf49a4..4718fe1 100644
>>> --- a/gcc/function.c
>>> +++ b/gcc/function.c
>>> @@ -4756,6 +4756,13 @@ push_cfun (struct function *new_cfun)
>>>  void
>>>  pop_cfun (void)
>>>  {
>>> +  if (cfun_stack.is_empty ())
>>> +    {
>>> +      set_cfun (NULL);
>>> +      current_function_decl = NULL_TREE;
>>> +      return;
>>> +    }
>>> +
>>>    struct function *new_cfun = cfun_stack.pop ();
>>>    /* When in_dummy_function, we do have a cfun but current_function_decl is
>>>       NULL.  We also allow pushing NULL cfun and subsequently changing
>>
>> Why again?  cfun should be set via push_cfun here so what's having cfun == NULL
>> at the pop_cfun point?  Or rather, what code used set_cfun () instead
>> of push_cfun ()?
>>
>>>
>>> If you are fine with that, looks we've fixed all issues related to the change, right?
>>> Updated version of the is attached.
>>>
>>> Martin
>>>
>>>>
>>>>> Martin
>>>>>
>>>
>
> Hi Richard.
>
> There's the patch we talked about yesterday. It contains a few modification that
> were necessary to make it working:
>
> 1) cgraph_node::expand_thunk uses just set_cfun (NULL) & current_function_decl = NULL because
>
>       bb = then_bb = else_bb = return_bb
>         = init_lowered_empty_function (thunk_fndecl, true, count);
>
> in last branch of expand_thunk which calls allocate_struct_function.
>
> 2) i386.c and rs6000.c call init_function_start, as I move preamble to callers, I did the same
> for these two functions
>
> I've been running regression test and bootstrap.

Looks good to me.

Thanks,
Richard.

> Martin