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

[Yvan Roux <yvan.roux@linaro.org>]

On 3 July 2017 at 12:48, Yvan Roux <yvan.roux@linaro.org> wrote:
> 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

ping

>> Thanks
>> Yvan
>>
>>> Wilco