FreeBSD ABI?

[b. f.]

> > Where is it documented?
> > Are there differences with the linux ABI?
> >
> > Particularly I am interested in stack alignment requirement. For example
> > i386 Solaris, Linux and MacOS have 16 bit stack alignment for procedure
> > calls. This is reflected in LLVM sources:
> >
> >   if (isTargetDarwin() || isTargetLinux() || isTargetSolaris() || Is64Bit)
> >     stackAlignment = 16;
> >
> >
> > But FreeBSD is excluded there. Is this a bug in LLVM which magically
> > doesn't cause crashes or this is correct and FreeBSD doesn't have 16 bit
> > alignment?
>
> the alignment is specified in bytes but yes, I wonder too, what is the
> stack alignment on freebsd on amd64/i386?
>
>

Isn't it supposed to [1] conform to:

http://www.sco.com/developers/devspecs/abi386-4.pdf
http://www.x86-64.org/documentation/abi.pdf

?

[1] See, for example:

http://lists.freebsd.org/pipermail/freebsd-hackers/2011-January/034045.html
http://www.freebsd.org/cgi/cvsweb.cgi/src/lib/csu/i386-elf/crt1_s.S
http://lists.freebsd.org/pipermail/svn-src-head/2010-December/023065.html