[fpc-devel] [Suggestion] Enumeration range-check intrinsic

[Sven Barth]

Am 14.07.2019 um 04:08 schrieb J. Gareth Moreton:
>
> Just a thought that I'd chuck in on this... I did wonder how practical 
> it would be to store checksums of all compiled procedures and the like 
> and to look for collisions.  When studying how the compiler is built, 
> I noticed a lot of the internal methods, due to conditional defines, 
> would compile into identical code, so merging them would reduce the 
> binary size if the linker is able to strip out procedures that are 
> never called.  Granted, I haven't done research on how Free Pascal 
> does Whole Program Optimisation yet, especially as it requiring a 
> separate compilation pass has always put me off.  I would have thought 
> that the linker should be able to handle it right there and then 
> because it has all the information it needs.
>
That would be a possible approach to use if the output format does not 
support combining equal sections. PE/COFF's COMDAT sections do have a 
flag that says that they need to have equal content (there are also 
other possibilities). Don't know right now whether ELF does.

Regards,
Sven