[fpc-devel] Question on updating FPC packages
florian at freepascal.org
Sun Oct 27 09:02:54 CET 2019
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.
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