[PATCH 0/5] Add support for R_386_GOT32X/R_X86_64_[REX_]GOTPCRELX

[H.J. Lu]

On Mon, Jan 18, 2016 at 9:14 AM, Rafael Espíndola
<rafael.espindola@gmail.com> wrote:
>> Since for some binop, linker needs to rewrite the REX byte, it needs
>> to know if instruction has a REX byte.  R_X86_64_GOTPCREL doesn't
>> have such information
>
> The byte stream before the R_X86_64_GOTPCREL location does. Checking
> for the REX prefix is not that different from checking if the
> instruction in a mov when converting mov to lea.
>

For mov to lea, linker doesn't need to rewrite the REX byte.  When linker
does need to rewrite the REX byte, it must be sure that the byte before
the opcode is the REX byte, not the part of the displacement of the
previous instruction.


-- 
H.J.