Re: [PATCH x86_64] Optimize access to globals in "-fpie -pie" builds with copy relocations

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Tue, Dec 2, 2014 at 12:01 PM, Uros Bizjak <ubizjak@gmail.com> wrote:
> On Tue, Dec 2, 2014 at 8:40 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>> On Tue, Dec 2, 2014 at 11:19 AM, Uros Bizjak <ubizjak@gmail.com> wrote:
>>> Hello!
>>>
>>>> Ping.
>>>>> Ping.
>>>>>> Ping.
>>>>>>> Ping.
>>>
>>> It would probably help reviewers if you pointed to actual path
>>> submission [1], which unfortunately contains the explanation in the
>>> patch itself [2], which further explains that this functionality is
>>> currently only supported with gold, patched with [3].
>>>
>>> [1] https://gcc.gnu.org/ml/gcc-patches/2014-09/msg00645.html
>>> [2] https://gcc.gnu.org/ml/gcc-patches/2014-09/txt2CHtu81P1O.txt
>>> [3] https://sourceware.org/ml/binutils/2014-05/msg00092.html
>>>
>>> After a bit of the above detective work, I think that new gcc option
>>> is not necessary. The configure should detect if new functionality is
>>> supported in the linker, and auto-configure gcc to use it when
>>> appropriate.
>>
>> I think GCC option is needed since one can use -fuse-ld= to
>> change linker.
>
> IMO, nobody will use this highly special x86_64-only option. It would
> be best for gnu-ld to reach feature parity with gold as far as this
> functionality is concerned. In this case, the optimization would be
> auto-configured, and would fire automatically, without any user
> intervention.
>

Let's do it.  I implemented the same feature in bfd linker on both
master and 2.25 branch.

-- 
H.J.