On 12/9/20 3:24 AM, Hongtao Liu via Gcc-patches wrote:
> On Wed, Dec 9, 2020 at 5:22 PM Prathamesh Kulkarni via Gcc-patches
> <gcc-patches@gcc.gnu.org> wrote:
>> On Wed, 9 Dec 2020 at 00:29, sunil.k.pandey <skpan...@sc.intel.com> wrote:
>>> On Linux/x86_64,
>>>
>>> 3a6e3ad38a17a03ee0139b49a0946e7b9ded1eb1 is the first bad commit
>>> commit 3a6e3ad38a17a03ee0139b49a0946e7b9ded1eb1
>>> Author: Prathamesh Kulkarni <prathamesh.kulka...@linaro.org>
>>> Date: Tue Dec 8 14:30:04 2020 +0530
>>>
>>> gimple-isel: Fold x CMP y ? -1 : 0 to x CMP y [PR97872]
>>>
>>> caused
>>>
>>> FAIL: gcc.target/i386/pr78102.c scan-assembler-times pcmpeqq 3
>> Hi,
>> This is a known issue with the patch, and discussed here:
>> https://gcc.gnu.org/pipermail/gcc/2020-December/234438.html
>> I guess Hongtao will check in a fix for that soon.
>>
> According to https://uops.info/table.html,
> both pcmpeqq and pcmpeqd use only port 1, so i think there's no
> performance difference between
>
> vpcmpeqq %xmm1, %xmm0, %xmm0
> vpxor %xmm1, %xmm1, %xmm1
> vpcmpeqq %xmm1, %xmm0, %xmm0
>
> and
>
> vpcmpeqq %xmm1, %xmm0, %xmm0
> vpcmpeqd %xmm1, %xmm1, %xmm1
> vpandn %xmm1, %xmm0, %xmm0
>
> So fix up testcase as below.
>
> gcc/testsuite
>
> * gcc.target/i386/i386/pr78102.c: Adjust testcase.
OK
jeff
