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Re: [PATCH, ARM] Enable ldrd/strd peephole rules unconditionally


On 18 November 2016 at 16:50, Bernd Edlinger <bernd.edlinger@hotmail.de> wrote:
> On 11/18/16 12:58, Christophe Lyon wrote:
>> On 17 November 2016 at 10:23, Kyrill Tkachov
>> <kyrylo.tkachov@foss.arm.com> wrote:
>>>
>>> On 09/11/16 12:58, Bernd Edlinger wrote:
>>>>
>>>> Hi!
>>>>
>>>>
>>>> This patch enables the ldrd/strd peephole rules unconditionally.
>>>>
>>>> It is meant to fix cases, where the patch to reduce the sha512
>>>> stack usage splits ldrd/strd instructions into separate ldr/str insns,
>>>> but is technically independent from the other patch:
>>>>
>>>> See https://gcc.gnu.org/ml/gcc-patches/2016-11/msg00523.html
>>>>
>>>> It was necessary to change check_effective_target_arm_prefer_ldrd_strd
>>>> to retain the true prefer_ldrd_strd tuning flag.
>>>>
>>>>
>>>> Bootstrapped and reg-tested on arm-linux-gnueabihf.
>>>> Is it OK for trunk?
>>>
>>>
>>> This is ok.
>>> Thanks,
>>> Kyrill
>>>
>>
>> Hi Bernd,
>>
>> Since you committed this patch (r242549), I'm seeing the new test
>> failing on some arm*-linux-gnueabihf configurations:
>>
>> FAIL:  gcc.target/arm/pr53447-5.c scan-assembler-times ldrd 10
>> FAIL:  gcc.target/arm/pr53447-5.c scan-assembler-times strd 9
>>
>> See http://people.linaro.org/~christophe.lyon/cross-validation/gcc/trunk/242549/report-build-info.html
>> for a map of failures.
>>
>> Am I missing something?
>
> Hi Christophe,
>
> as always many thanks for your testing...
>
> I have apparently only looked at the case -mfloat-abi=soft here, which
> is what my other patch is going to address.  But all targets with
> -mfpu=neon -mfloat-abi=hard can also use vldr.64 instead of ldrd
> and vstr.64 instead of strd, which should be accepted as well.
>
> So the attached patch should fix at least most of the fallout.
>

I've tested it, and indeed it fixes the failures I've reported.

Thanks

> Is it OK for trunk?
>
>
> Thanks
> Bernd.


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