[Bug gas/24546] x86-64 far jump/call encoding issues

[andrew.cooper3 at citrix dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=24546

--- Comment #4 from Andrew Cooper <andrew.cooper3 at citrix dot com> ---
(In reply to H.J. Lu from comment #3)
> AMD64 manual says:
> 
> CALL FAR pntr16:16 9A cd Far call direct, with the target specified by a far
> pointer
> contained in the instruction. (Invalid in 64-bit mode.)
> CALL FAR pntr16:32 9A cp Far call direct, with the target specified by a far
> pointer
> contained in the instruction. (Invalid in 64-bit mode.)
> CALL FAR mem16:16 FF /3 Far call indirect, with the target specified by a
> far pointer
> in memory.
> CALL FAR mem16:32 FF /3 Far call indirect, with the target specified by a
> far pointer
> in memory.

After some experimentation, it turns out that it really is only Intel
processors which implement the mem16:64 form.  AMD processors ignore the REX
prefix and use mem16:32 form, even when REX-encoded.

-- 
You are receiving this mail because:
You are on the CC list for the bug.