[fpc-devel] Question on updating FPC packages

[J. Gareth Moreton]

On 29/10/2019 14:24, Michael Van Canneyt wrote:
>
>
> On Tue, 29 Oct 2019, J. Gareth Moreton wrote:
>
>> Please note that only Marco's e-mails are making the list.  I don't 
>> see Michael's responses.
>
> That's probably because I am not responding ;-)
>
> Michael.

Yep, just noticed that Marco was responding to your messages from a few 
days ago!  Perception fail!

In regards to passing everything into XMM0, try running 
"tests/test/cg/tvectorcall1.pp" on Linux.  It's a bit of a weird test 
because there's a lot of Win64 stuff that's not compiled since it tests 
aggregates, something that only vectorcall takes advantage of.

Nevertheless, if you get an error such as 'FAIL: 
HorizontalAddSingle(HVA) has the vector in the wrong register.', then 
the System V ABI is not passing the __m128 type properly. The way it 
tests this is via a pair of functions, one in Pascal and one in assembler:

function HorizontalAddSingle(V: TM128): Single; vectorcall;
begin
   HorizontalAddSingle := V.M128_F32[0] + V.M128_F32[1] + V.M128_F32[2] 
+ V.M128_F32[3];
end;

function HorizontalAddSingle_ASM(V: TM128): Single; vectorcall; 
assembler; nostackframe;
asm
   HADDPS XMM0, XMM0
   HADDPS XMM0, XMM0
end;

If the results are not equal, then the entire vector isn't in XMM0.  I 
haven't tested it on Linux as much as I would like because I have to 
boot into a virtual machine to do so, and I'm still a bit of a Linux 
novice.  I'm curious to know what the assembler dump is though.

Gareth aka. Kit


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