* Paul Koning:
>> On Sep 21, 2018, at 2:17 PM, Florian Weimer <fwei...@redhat.com> wrote:
>>
>> * Segher Boessenkool:
>>
>>> On Fri, Sep 21, 2018 at 12:59:27PM +0200, Florian Weimer wrote:
>>>> 2018-09-21 Florian Weimer <fwei...@redhat.com>
>>>>
>>>> PR middle-end/81035
>>>> * doc/extend.texi (Common Function Attributes): Mention that
>>>> noreturn suppresses tail call optimization.
>>>
>>>> +In order to preserve backtraces, GCC will never turn calls to
>>>> +@code{noreturn} functions into tail calls.
>>>
>>> Should we document this? Shouldn't we fix it, instead?
>>
>> Fix how? What is currently broken?
>>
>> For things like assertion failures, we do not want to replace the
>> current stack frame with that of __assert_fail, I think.
>
> I agree. Also, tailcalls are optimizations. Speed optimizing
> noreturn calls is obviously not interesting. Calls to noreturn
> functions are short, and turning them into a jump probably makes no
> difference in size, or if it does, not enough to matter.
The example in the bug report shows that tail calls can avoid setting up
a stack frame, leading to smaller code size and CFI.
Thanks,
Florian
