From: "Stefan Kanthak" <stefan.kanthak@nexgo.de>
To: "Andrew Pinski" <pinskia@gmail.com>
Cc: "Jakub Jelinek" <jakub@redhat.com>, <gcc@gnu.org>
Subject: Re: Another epic optimiser failure
Date: Sun, 28 May 2023 00:00:41 +0200 [thread overview]
Message-ID: <71FF9C7056554132A16BCFD05CAB116C@H270> (raw)
In-Reply-To: <CA+=Sn1nE+FVpOfDp=iDoPo-bijkGmv6T6X_0iA-VUTMyoqr3yQ@mail.gmail.com>
"Andrew Pinski" <pinskia@gmail.com> wrote:
> On Sat, May 27, 2023 at 2:38 PM Stefan Kanthak <stefan.kanthak@nexgo.de> wrote:
>>
>> "Jakub Jelinek" <jakub@redhat.com> wrote, completely clueless:
>>
>>> On Sat, May 27, 2023 at 11:04:11PM +0200, Stefan Kanthak wrote:
>>>> OUCH: popcnt writes the WHOLE result register, there is ABSOLUTELY
>>>> no need to clear it beforehand nor to clear the higher 24 bits
>>>> afterwards!
>>>
>>> Except that there is. See https://gcc.gnu.org/PR62011 for details.
>>
>> GUESS WHY I EXPLICITLY WROTE
>>
>> | JFTR: before GCC zealots write nonsense: see -march= or -mtune=
>>
>> NOT AMUSED ABOUT YOUR CRYING INCOMPETENCE!
>
> So you want to complain about GCC knowing about an Intel performance errata????
Ever heard about cargo cult?
Read the options I used CAREFULLY
| gcc -m32 -march=alderlake -O3
| gcc -m32 -march=sapphirerapids -O3
| gcc -m32 -mpopcnt -mtune=sapphirerapids -O3
> If you read that bug report, you would have learned why the zeroing is
> done. I am sorry you hate GCC for actually following advice from the
> processor maker after all.
HSD146 does NOT apply to Alder Lake or Sapphire Rapids!
NOT AMUSED ABOUT YOUR INCOMPETENCE TOO!
Stefan
next prev parent reply other threads:[~2023-05-27 22:03 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-27 21:04 Stefan Kanthak
2023-05-27 21:20 ` Jakub Jelinek
2023-05-27 21:28 ` Stefan Kanthak
2023-05-27 21:42 ` Andrew Pinski
2023-05-27 22:00 ` Stefan Kanthak [this message]
2023-05-27 22:46 ` Jonathan Wakely
2023-05-28 6:28 ` Nicholas Vinson
2023-05-28 7:50 Julian Waters
2023-05-29 19:01 ` Dave Blanchard
2023-05-29 23:44 ` Nicholas Vinson
2023-05-30 4:04 ` Julian Waters
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