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Re: [PATCH] [AArch64] Implement popcount pattern
- From: Andrew Pinski <pinskia at gmail dot com>
- To: James Greenhalgh <james dot greenhalgh at arm dot com>
- Cc: "Hurugalawadi, Naveen" <Naveen dot Hurugalawadi at cavium dot com>, Kyrill Tkachov <kyrylo dot tkachov at foss dot arm dot com>, "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>, "Pinski, Andrew" <Andrew dot Pinski at cavium dot com>, Marcus Shawcroft <marcus dot shawcroft at arm dot com>, Richard Earnshaw <Richard dot Earnshaw at arm dot com>, "nd at arm dot com" <nd at arm dot com>
- Date: Thu, 2 Feb 2017 21:56:30 -0800
- Subject: Re: [PATCH] [AArch64] Implement popcount pattern
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- References: <CO2PR07MB26944CDE12E84FD22A41F68583870@CO2PR07MB2694.namprd07.prod.outlook.com> <CO2PR07MB2694C853BCFC5E83EF1E3D3583980@CO2PR07MB2694.namprd07.prod.outlook.com> <584E81A9.8000402@foss.arm.com> <SN2PR07MB27028DC0EDBA36D4C0E9671E839B0@SN2PR07MB2702.namprd07.prod.outlook.com> <584FE2A8.2080908@foss.arm.com> <20170201135635.GA1848@arm.com> <CO2PR07MB26945D8A042A09F438F06844834C0@CO2PR07MB2694.namprd07.prod.outlook.com> <20170202115540.GB37031@arm.com>
On Thu, Feb 2, 2017 at 3:55 AM, James Greenhalgh
<james.greenhalgh@arm.com> wrote:
> On Thu, Feb 02, 2017 at 04:03:42AM +0000, Hurugalawadi, Naveen wrote:
>> Hi James and Kyrill,
>>
>> Thanks for the review and comments on the patch.
>>
>> >> On ILP32 systems this would still use the SImode patterns,
>> >> so I suggest you use __builtin_popcountll and
>> >> an unsigned long long return type to ensure you always exercise the 64-bit code.
>>
>> Sorry for not commenting on this part.
>> The issue is that code generates "__popcountdi2" for all the codes in testcase
>> for LP64 and ILP32 variants.
>> __builtin_popcount, __builtin_popcountl and __builtin_popcount.
>>
>> Hence, modified the patch to check for "popcount".
>
> I don't understand this comment and how it relates to your updated
> patch (which still checks for CNT).
Now I understand Kyrill's comments as Naveen and I did not understand
before. What Naveen was trying to test was that there was no longer
any call to __popcountdi2 or __popcountsi2 any more for all three:
__builtin_popcount, __builtin_popcountl and __builtin_popcountll.
Kyrill was asking him to change the test for __builtin_popcountl to
__builtin_popcountll even though there was already one test in that
file already. Now of course what should change still is the argument
types to foo1/foo2 so they take long and long long respectively. He
will post a new version of the patch soon.
>
>> Bootstrapped and regression tested on AArch64-Thunderx-Linux machine.
>>
>> Please find attached the modified patch and let us know if its okay?
>
> Could you please clarify what you meant above? The patch looks fine (though
> possibly not for Stage 4), but I'm not sure of your intent.
What he meant was he tested on aarch64-linux-gnu with no regressions.
Is it ok for when stage 1 opens with the change of the testcase?
Thanks,
Andrew
>
> Thanks,
> James