[xproto: PATCH] Xmd.h: amd64-x32 ABI defines sizeof(long) == sizeof (void*) == 4

[Sergei Trofimovich]

> On 12/20/11 12:26, Sergei Trofimovich wrote:
> > What would you prefer?
> 
> I'd prefer not supporting broken hacks pretending to be new ABI models.
> 
> Is there any real benefit to "AMD64-x32" over simply x86-32

Whole AMD64 ISA is accessible: twice as much registers (including xmm/ymm),
instruction extensions available only in "long mode".

It helps help codecs embedded into browsers and players.
C calling convention uses registers (first six integer parameters go to registers)
which reduces stack memory traffic.

Quite nice comparing to what we have in ia32.

> or AMD64 for X applications?

Pointer memory footprint is on ia32 level. Saves Dcache and RAM for huge programs
with large amount of references (like firefox and KDE).

-- 

  Sergei
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 198 bytes
Desc: not available
URL: <http://lists.x.org/archives/xorg-devel/attachments/20111221/52920a88/attachment.pgp>