[fpc-devel] fpc trunk / parentfp for debugger / missing

[Yuriy Sydorov]

On 20.06.2020 15:49, Jonas Maebe wrote:
> On 20/06/2020 14:31, Yuriy Sydorov wrote:
>> On 20.06.2020 14:38, Jonas Maebe wrote:
>>> On 20/06/2020 13:15, Yuriy Sydorov wrote:
>>>> On 20.06.2020 2:04, Martin wrote:
>>>>> I just updated to fpc trunk 45658
>>>>>
>>>>> It seems sometime in the last 3 or 4 month a change was made that
>>>>> leads to "parentfp" being optimized away.
>>>>> Even with -O- or -O1 (many users do O1 for debugging)
>>>>
>>>> I've turned off optimization of parentfp when -O- in r45661.
>>>
>>> Maybe it can be tied to the -Oostackframe optimisation setting.
>>
>> Some CPU targets - jvm at least - doesn't support cs_opt_stackframe, but
>> the parentfp optimization applies for any CPU target.
> 
> At first sight, the only thing that needs to be done to "support"
> cs_opt_stackframe for the JVM target is to always set
> pi_has_stackparameter there.

Yes, but currently it is not supported. :)

>> The parentfp optimization need to be tied to some generic optimization.
>> cs_opt_remove_empty_proc looks good for this.
> 
> That feels rather unrelated to me.

cs_opt_stackframe also is only vaguely related to the parentfp optimization.

Maybe implement this in a clean way by adding a new generic optimization cs_opt_hiddenpara?
Enable it for -O2. It may be used in future to optimize unused $self.

Yuriy.