Re: [boost] [config] [chrono] consexpr workaround

Subject: Re: [boost] [config] [chrono] consexpr workaround
From: Vicente J. Botet Escriba (vicente.botet_at_[hidden])
Date: 2013-03-20 17:39:05

Le 20/03/13 18:57, Krzysztof Czainski a écrit :
> 2013/3/19 Vicente J. Botet Escriba <vicente.botet_at_[hidden]>
>
>> Le 19/03/13 22:25, Krzysztof Czainski a écrit :
>>
>>   2013/3/19 Vicente J. Botet Escriba <vicente.botet_at_[hidden]>
>>>   Le 19/03/13 17:00, Krzysztof Czainski a écrit :
>>>> So now, narrowing the question to use of
>>>>
>>>>   BOOST_CONSTEXPR in Boost.Chrono:
>>>>> 1. Could the functions marked BOOST_CONSTEXPR be also marked inline (and
>>>>> this question probably applies to other Boost libraries)?
>>>>> 2. This is probably related only to the TI compiler I use: marking
>>>>> constructors inline doesn't work for me, they need to be marked
>>>>> BOOST_FORCEINLINE (I've configured it), so could the constexpr
>>>>> constructors
>>>>> in Boost.Chrono be marked with BOOST_FORCEINLINE as well?
>>>>>
>>>>>    Hi,
>>>>>
>>>> could you point me to the cases that need to be inlined that the compiler
>>>> doesn't inline by itself?
>>>>
>>>> Please create a ticket so that I don't forget it.
>>>>
>>>> Best,
>>>> Vicente
>>>>
>>> Hi Vincente,
>>>
>>> Thanks for looking at this.
>>>
>>> I think this TI compiler doesn't inline anything not marked inline.
>>> Additionally it doesn't seem to inline constructors, unless marked
>>> BOOST_FORCEINLINE [1].
>>>
>>> So if there aren't any thoughts against this, I suggest all constexpr
>>> functions in duration and time_point to be marked inline, and constexpr
>>> constructors to be marked forceinline. Or should I just touch the cases,
>>> that need to be inline in my example situation? I'd prefer the former ;-)
>>>
>>> I'll create a ticket and supply a patch shortly.
>>>
>>> Cheers,
>>> Kris
>>>
>>> [1] The TI compiler supports the GCC extension attribute forceinline.
>>>
>>>
>>>   What makes the consexpr functions different from the other functions
>> that the compiler could inline and it doesn't?
>> Are you proposing that all the boost libraries uses BOOST_FORCEINLINE on
>> all the functions defined in the declaration?
>>
>> Vicente
>>
> I misread those files, all constexpr function are already inline ;-)
>
> So I'm only talking about constructors (3 constructors of class duration,
> and 3 constructors of class time_point), and constexpr doesn't have much to
> do with this, sorry for the noise.

I don't understand the conditions that need to use BOOST_FORCEINLINE . 
There are a lot of functions that are not marked inline and I expect the 
compiler to inline as e.g.

         BOOST_CONSTEXPR
         duration time_since_epoch() const
         {
             return d_;
         }

Should I add BOOST_FORCEINLINE to this kind of code also?
> Ticket #8318 created with a patch.
>
I will apply the patch soon.

Best,
Vicente