[PATCH][AArch64][GCC 6] PR target/79041: Correct -mpc-relative-literal-loads logic in aarch64_classify_symbol

[Yvan Roux]

On 27 June 2017 at 13:14, Yvan Roux <yvan.roux@linaro.org> wrote:
> Hi Wilco
>
> On 27 June 2017 at 12:53, Wilco Dijkstra <Wilco.Dijkstra@arm.com> wrote:
>> Hi Yvan,
>>
>>> Here is the backport of Wilco's patch (r237607) along with Kyrill's
>>> one (r244643, which removed the remaining occurences of
>>> aarch64_nopcrelative_literal_loads).  To fix the issue the original
>>> patch has to be modified, to keep aarch64_pcrelative_literal_loads
>>> test for large models in aarch64_classify_symbol.
>>
>> The patch looks good to me, however I can't approve it.
>
> ok thanks for the review.
>
>>> On trunk and gcc-7-branch the :lo12: relocations are not generated
>>> because of Wilco's fix for pr78733 (r243456 and 243486), but my
>>> understanding is that the bug is still present since compiling
>>> gcc.target/aarch64/pr78733.c with -mcmodel=large brings back the
>>> :lo12: relocations (I'll submit a patch to add the test back if my
>>> understanding is correct).
>>
>> You're right, eventhough -mpc-relative-literal-loads doesn't make much sense
>> in the large memory model, it seems best to keep the option orthogonal to
>> enable the workaround. I've prepared a patch to fix this on trunk/GCC7.
>> It also adds a test which we should add to your changes to GCC6 too.
>
> ok, I think it is what kugan's proposed earlier today in:
>
> https://gcc.gnu.org/ml/gcc-patches/2017-06/msg01967.html
>
> I agree that -mpc-relative-literal-loads and large memory model
> doesn't make much sense, now it is what is used in kernel build
> system, but if you handle that in a bigger fix already, that's awesome
> :)

ping?
https://gcc.gnu.org/ml/gcc-patches/2017-06/msg01708.html

> Thanks
> Yvan
>
>> Wilco