[fpc-devel] Question on updating FPC packages

[Florian Klämpfl]

Am 27.10.19 um 07:32 schrieb J. Gareth Moreton:
> I guess you're right.  It just seems weird because the System V ABI was 
> designed from the start to use the MM registers fully, so long as the 
> data is aligned.  In effect, it had vectorcall wrapped into its design 
> from the start.  Granted, vectorcall has some advantages and can deal 
> with relatively complex aggregates that the System V ABI cannot handle 
> (for example, a record type that contains a normal vector and 
> information relating to bump mapping).
> 
> I just hoped that making updates to uComplex, while ensuring existing 
> Pascal code still compiles, would help take advantage of modern ABI designs.

Is there currently any example which shows that vectorcall has any 
advantage with FPC? Else I would propose first to make FPC able to take 
advantage of it and then talk about if we really add vectorcall. 
Currently I fear, FPC gets only into trouble when using vectorcall as it 
tries first to push everything into one xmm register and then splits 
this again in the callee.