Where to find amd64 ABI information for FreeBSD?

[Bruce Evans]

On Wed, 6 Apr 2011, Kostik Belousov wrote:

> On Tue, Apr 05, 2011 at 03:10:37PM -0700, Xin LI wrote:
>> Is there a place to find ABI information for GCC on FreeBSD?
>>  Specifically, I'm looking for which registers has to be preserved
>> across function call?  (Or do we follow System V Application Binary

I've always looked at the source code (mainly i386.h and i386.md).  I
don't know of any better way for i386.

>> Interface AMD64 Architecture Processor Supplement Draft Version 0.99.5?)
>
> The parts of the mentioned document that depend on compiler and
> toolchain, are fully valid for FreeBSD. Our non-compliance is mostly
> in the specified bits of the kernel/usermode interface.

Is it still a de-facto standard only at 0.99.x?  I only have 0.95 from
2005.  I guess little has changed.

Bruce