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Chandler Carruth via llvm-dev

2017-May-30 20:07 UTC

[llvm-dev] Enable vectorizer-maximize-bandwidth by default?

On Tue, May 30, 2017 at 1:40 AM Agabaria, Mohammed via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> We’re seeing nice improvements but also significant degradations on IA,
> which we would like to investigate before the patch is committed.
>
>
>
> Major degradations we see:
>
>
>
> networking
>
>    ip_pktcheckb1m          -6.80 %
>
>    ip_pktcheckb2m          -6.74 %
>
>    ip_pktcheckb4m          -7.57 %
>
>    ip_pktcheckb512k       -6.58 %
>
> Telecom
>
>    autcor00data_1          -78.02 %
>
>    autcor00data_2          -76.80 %
>
>    autcor00data_3          -77.00 %
>
> (on Atom)
>
>
>
> We still working on creating reproducers.
>
> In general we support this patch, just want to have a chance to
> investigate the issues. We need a few days for that.
>
I mean, OK... but keep in mind that Dehao's original email went out over a
week ago, so this patch has already been held up a while. As these
benchmarks aren't readily available, we also can't do anything to help
until a test case is posted.

Have you considered contributing these benchmarks to the LLVM test suite?

>
>
>
>
>
>
> *From:* llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org
> <llvm-dev-bounces at lists.llvm.org>] *On Behalf Of *Chandler Carruth
via
> llvm-dev
> *Sent:* Tuesday, May 30, 2017 11:27
> *To:* Flamedoge <code.kchoi at gmail.com>; Dehao Chen <dehao at
google.com>
> *Cc:* llvm-dev <llvm-dev at lists.llvm.org>
> *Subject:* Re: [llvm-dev] Enable vectorizer-maximize-bandwidth by default?
>
>
>
> If you care about such hardware, please run benchmarks with the flag?
>
>
>
> Dehao has made this flag available. It is important that those who care
> about particular hardware provid ebenchmark results. Not everyone in the
> community will have access to particular hardware variants.
>
>
>
> On Tue, May 30, 2017 at 1:14 AM Flamedoge <code.kchoi at gmail.com>
wrote:
>
> Thank you for running these.
>
>
>
> May I suggest testing on AVX2 capable hardware? That would be Intel
> Haswell, AMD Carrizo and up.
>
> I'm not sure what "vectorizer-maximize-bandwidth" implies,
but doubling
> the vector lanes may help light up parallel regions.
>
>
>
> Kevin
>
>
>
> On Tue, May 30, 2017 at 12:58 AM, Chandler Carruth via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
> On Fri, May 19, 2017 at 4:01 PM Adam Nemet via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
> I will run it on Cyclone/AArch64 next week.
>
>
>
> FYI, we're still waiting on these Adam...
>
>
>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
> ---------------------------------------------------------------------
> Intel Israel (74) Limited
>
> This e-mail and any attachments may contain confidential material for
> the sole use of the intended recipient(s). Any review or distribution
> by others is strictly prohibited. If you are not the intended
> recipient, please contact the sender and delete all copies.
> _______________________________________________
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> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
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Agabaria, Mohammed via llvm-dev

2017-Jun-01 13:12 UTC

head link

[llvm-dev] Enable vectorizer-maximize-bandwidth by default?

Attached the first reproducer of the Atom\SLM arch. degradation.  (~70%
degradation).
Chandler, those are part of EEMBC benchmarks.

From: Chandler Carruth [mailto:chandlerc at gmail.com]
Sent: Tuesday, May 30, 2017 23:07
To: Agabaria, Mohammed <mohammed.agabaria at intel.com>; Flamedoge
<code.kchoi at gmail.com>; Dehao Chen <dehao at google.com>
Cc: llvm-dev <llvm-dev at lists.llvm.org>
Subject: Re: [llvm-dev] Enable vectorizer-maximize-bandwidth by default?

On Tue, May 30, 2017 at 1:40 AM Agabaria, Mohammed via llvm-dev <llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote:
We’re seeing nice improvements but also significant degradations on IA, which we
would like to investigate before the patch is committed.

Major degradations we see:

networking
   ip_pktcheckb1m          -6.80 %
   ip_pktcheckb2m          -6.74 %
   ip_pktcheckb4m          -7.57 %
   ip_pktcheckb512k       -6.58 %
Telecom
   autcor00data_1          -78.02 %
   autcor00data_2          -76.80 %
   autcor00data_3          -77.00 %
(on Atom)

We still working on creating reproducers.
In general we support this patch, just want to have a chance to investigate the
issues. We need a few days for that.

I mean, OK... but keep in mind that Dehao's original email went out over a
week ago, so this patch has already been held up a while. As these benchmarks
aren't readily available, we also can't do anything to help until a test
case is posted.

Have you considered contributing these benchmarks to the LLVM test suite?

From: llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org] On Behalf Of Chandler
Carruth via llvm-dev
Sent: Tuesday, May 30, 2017 11:27
To: Flamedoge <code.kchoi at gmail.com<mailto:code.kchoi at
gmail.com>>; Dehao Chen <dehao at google.com<mailto:dehao at
google.com>>
Cc: llvm-dev <llvm-dev at lists.llvm.org<mailto:llvm-dev at
lists.llvm.org>>
Subject: Re: [llvm-dev] Enable vectorizer-maximize-bandwidth by default?

If you care about such hardware, please run benchmarks with the flag?

Dehao has made this flag available. It is important that those who care about
particular hardware provid ebenchmark results. Not everyone in the community
will have access to particular hardware variants.

On Tue, May 30, 2017 at 1:14 AM Flamedoge <code.kchoi at
gmail.com<mailto:code.kchoi at gmail.com>> wrote:
Thank you for running these.

May I suggest testing on AVX2 capable hardware? That would be Intel Haswell, AMD
Carrizo and up.
I'm not sure what "vectorizer-maximize-bandwidth" implies, but
doubling the vector lanes may help light up parallel regions.

Kevin

On Tue, May 30, 2017 at 12:58 AM, Chandler Carruth via llvm-dev <llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote:
On Fri, May 19, 2017 at 4:01 PM Adam Nemet via llvm-dev <llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote:
I will run it on Cyclone/AArch64 next week.

FYI, we're still waiting on these Adam...

_______________________________________________
LLVM Developers mailing list
llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>
http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev

---------------------------------------------------------------------
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recipient, please contact the sender and delete all copies.
_______________________________________________
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http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
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Dehao Chen via llvm-dev

2017-Jun-02 17:53 UTC

head link

[llvm-dev] Enable vectorizer-maximize-bandwidth by default?

Thanks for the testcase. Could you add some more details about the
regression?

* How to build/run the testcase to reproduce the degradation?
* Is the degradation only exist in ATOM/SLM arch? If yes, could you help
analyze why maximize the bandwidth would make performance worse (as we do
not have these arches to run the perf tests).

Thanks,
Dehao

On Thu, Jun 1, 2017 at 6:12 AM, Agabaria, Mohammed <
mohammed.agabaria at intel.com> wrote:
> Attached the first reproducer of the Atom\SLM arch. degradation.  (~70%
> degradation).
>
> Chandler, those are part of EEMBC benchmarks.
>
>
>
> *From:* Chandler Carruth [mailto:chandlerc at gmail.com]
> *Sent:* Tuesday, May 30, 2017 23:07
> *To:* Agabaria, Mohammed <mohammed.agabaria at intel.com>; Flamedoge
<
> code.kchoi at gmail.com>; Dehao Chen <dehao at google.com>
>
> *Cc:* llvm-dev <llvm-dev at lists.llvm.org>
> *Subject:* Re: [llvm-dev] Enable vectorizer-maximize-bandwidth by default?
>
>
>
> On Tue, May 30, 2017 at 1:40 AM Agabaria, Mohammed via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
> We’re seeing nice improvements but also significant degradations on IA,
> which we would like to investigate before the patch is committed.
>
>
>
> Major degradations we see:
>
>
>
> networking
>
>    ip_pktcheckb1m          -6.80 %
>
>    ip_pktcheckb2m          -6.74 %
>
>    ip_pktcheckb4m          -7.57 %
>
>    ip_pktcheckb512k       -6.58 %
>
> Telecom
>
>    autcor00data_1          -78.02 %
>
>    autcor00data_2          -76.80 %
>
>    autcor00data_3          -77.00 %
>
> (on Atom)
>
>
>
> We still working on creating reproducers.
>
> In general we support this patch, just want to have a chance to
> investigate the issues. We need a few days for that.
>
>
>
> I mean, OK... but keep in mind that Dehao's original email went out
over a
> week ago, so this patch has already been held up a while. As these
> benchmarks aren't readily available, we also can't do anything to
help
> until a test case is posted.
>
>
>
> Have you considered contributing these benchmarks to the LLVM test suite?
>
>
>
>
>
>
>
>
>
> *From:* llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org
> <llvm-dev-bounces at lists.llvm.org>] *On Behalf Of *Chandler Carruth
via
> llvm-dev
> *Sent:* Tuesday, May 30, 2017 11:27
> *To:* Flamedoge <code.kchoi at gmail.com>; Dehao Chen <dehao at
google.com>
> *Cc:* llvm-dev <llvm-dev at lists.llvm.org>
> *Subject:* Re: [llvm-dev] Enable vectorizer-maximize-bandwidth by default?
>
>
>
> If you care about such hardware, please run benchmarks with the flag?
>
>
>
> Dehao has made this flag available. It is important that those who care
> about particular hardware provid ebenchmark results. Not everyone in the
> community will have access to particular hardware variants.
>
>
>
> On Tue, May 30, 2017 at 1:14 AM Flamedoge <code.kchoi at gmail.com>
wrote:
>
> Thank you for running these.
>
>
>
> May I suggest testing on AVX2 capable hardware? That would be Intel
> Haswell, AMD Carrizo and up.
>
> I'm not sure what "vectorizer-maximize-bandwidth" implies,
but doubling
> the vector lanes may help light up parallel regions.
>
>
>
> Kevin
>
>
>
> On Tue, May 30, 2017 at 12:58 AM, Chandler Carruth via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
> On Fri, May 19, 2017 at 4:01 PM Adam Nemet via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
> I will run it on Cyclone/AArch64 next week.
>
>
>
> FYI, we're still waiting on these Adam...
>
>
>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
> ---------------------------------------------------------------------
> Intel Israel (74) Limited
>
> This e-mail and any attachments may contain confidential material for
> the sole use of the intended recipient(s). Any review or distribution
> by others is strictly prohibited. If you are not the intended
> recipient, please contact the sender and delete all copies.
>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
> ---------------------------------------------------------------------
> Intel Israel (74) Limited
>
> This e-mail and any attachments may contain confidential material for
> the sole use of the intended recipient(s). Any review or distribution
> by others is strictly prohibited. If you are not the intended
> recipient, please contact the sender and delete all copies.
>-------------- next part --------------
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Zaks, Ayal via llvm-dev

2017-Jun-06 19:32 UTC

head link

[llvm-dev] Enable vectorizer-maximize-bandwidth by default?

Chandler> Have you considered contributing these benchmarks to the LLVM test
suite?

These benchmarks are not ours to contribute; they’re from the EEMBC standard,
whose availability is similar in nature to that of SPEC.


From: llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org] On Behalf Of Chandler
Carruth via llvm-dev
Sent: Tuesday, May 30, 2017 23:07
To: Agabaria, Mohammed <mohammed.agabaria at intel.com>; Flamedoge
<code.kchoi at gmail.com>; Dehao Chen <dehao at google.com>
Cc: llvm-dev <llvm-dev at lists.llvm.org>
Subject: Re: [llvm-dev] Enable vectorizer-maximize-bandwidth by default?

On Tue, May 30, 2017 at 1:40 AM Agabaria, Mohammed via llvm-dev <llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote:
We’re seeing nice improvements but also significant degradations on IA, which we
would like to investigate before the patch is committed.

Major degradations we see:

networking
   ip_pktcheckb1m          -6.80 %
   ip_pktcheckb2m          -6.74 %
   ip_pktcheckb4m          -7.57 %
   ip_pktcheckb512k       -6.58 %
Telecom
   autcor00data_1          -78.02 %
   autcor00data_2          -76.80 %
   autcor00data_3          -77.00 %
(on Atom)

We still working on creating reproducers.
In general we support this patch, just want to have a chance to investigate the
issues. We need a few days for that.

I mean, OK... but keep in mind that Dehao's original email went out over a
week ago, so this patch has already been held up a while. As these benchmarks
aren't readily available, we also can't do anything to help until a test
case is posted.

Have you considered contributing these benchmarks to the LLVM test suite?




From: llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org] On Behalf Of Chandler
Carruth via llvm-dev
Sent: Tuesday, May 30, 2017 11:27
To: Flamedoge <code.kchoi at gmail.com<mailto:code.kchoi at
gmail.com>>; Dehao Chen <dehao at google.com<mailto:dehao at
google.com>>
Cc: llvm-dev <llvm-dev at lists.llvm.org<mailto:llvm-dev at
lists.llvm.org>>
Subject: Re: [llvm-dev] Enable vectorizer-maximize-bandwidth by default?

If you care about such hardware, please run benchmarks with the flag?

Dehao has made this flag available. It is important that those who care about
particular hardware provid ebenchmark results. Not everyone in the community
will have access to particular hardware variants.

On Tue, May 30, 2017 at 1:14 AM Flamedoge <code.kchoi at
gmail.com<mailto:code.kchoi at gmail.com>> wrote:
Thank you for running these.

May I suggest testing on AVX2 capable hardware? That would be Intel Haswell, AMD
Carrizo and up.
I'm not sure what "vectorizer-maximize-bandwidth" implies, but
doubling the vector lanes may help light up parallel regions.

Kevin

On Tue, May 30, 2017 at 12:58 AM, Chandler Carruth via llvm-dev <llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote:
On Fri, May 19, 2017 at 4:01 PM Adam Nemet via llvm-dev <llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote:
I will run it on Cyclone/AArch64 next week.

FYI, we're still waiting on these Adam...

_______________________________________________
LLVM Developers mailing list
llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>
http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev

---------------------------------------------------------------------
Intel Israel (74) Limited

This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.
_______________________________________________
LLVM Developers mailing list
llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>
http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
---------------------------------------------------------------------
Intel Israel (74) Limited

This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.
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Agabaria, Mohammed via llvm-dev

2017-Jun-07 12:23 UTC

head link

[llvm-dev] Enable vectorizer-maximize-bandwidth by default?

Guys I have uploaded a fix on phabricator which fix the issue in SLM:
https://reviews.llvm.org/D33983

From: Zaks, Ayal
Sent: Tuesday, June 06, 2017 22:32
To: Chandler Carruth <chandlerc at gmail.com>; Agabaria, Mohammed
<mohammed.agabaria at intel.com>; Flamedoge <code.kchoi at
gmail.com>; Dehao Chen <dehao at google.com>
Cc: llvm-dev <llvm-dev at lists.llvm.org>
Subject: RE: [llvm-dev] Enable vectorizer-maximize-bandwidth by default?

Chandler> Have you considered contributing these benchmarks to the LLVM test
suite?

These benchmarks are not ours to contribute; they’re from the EEMBC standard,
whose availability is similar in nature to that of SPEC.

From: llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org] On Behalf Of Chandler
Carruth via llvm-dev
Sent: Tuesday, May 30, 2017 23:07
To: Agabaria, Mohammed <mohammed.agabaria at
intel.com<mailto:mohammed.agabaria at intel.com>>; Flamedoge
<code.kchoi at gmail.com<mailto:code.kchoi at gmail.com>>; Dehao
Chen <dehao at google.com<mailto:dehao at google.com>>
Cc: llvm-dev <llvm-dev at lists.llvm.org<mailto:llvm-dev at
lists.llvm.org>>
Subject: Re: [llvm-dev] Enable vectorizer-maximize-bandwidth by default?

On Tue, May 30, 2017 at 1:40 AM Agabaria, Mohammed via llvm-dev <llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote:
We’re seeing nice improvements but also significant degradations on IA, which we
would like to investigate before the patch is committed.

Major degradations we see:

networking
   ip_pktcheckb1m          -6.80 %
   ip_pktcheckb2m          -6.74 %
   ip_pktcheckb4m          -7.57 %
   ip_pktcheckb512k       -6.58 %
Telecom
   autcor00data_1          -78.02 %
   autcor00data_2          -76.80 %
   autcor00data_3          -77.00 %
(on Atom)

We still working on creating reproducers.
In general we support this patch, just want to have a chance to investigate the
issues. We need a few days for that.

I mean, OK... but keep in mind that Dehao's original email went out over a
week ago, so this patch has already been held up a while. As these benchmarks
aren't readily available, we also can't do anything to help until a test
case is posted.

Have you considered contributing these benchmarks to the LLVM test suite?

From: llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org] On Behalf Of Chandler
Carruth via llvm-dev
Sent: Tuesday, May 30, 2017 11:27
To: Flamedoge <code.kchoi at gmail.com<mailto:code.kchoi at
gmail.com>>; Dehao Chen <dehao at google.com<mailto:dehao at
google.com>>
Cc: llvm-dev <llvm-dev at lists.llvm.org<mailto:llvm-dev at
lists.llvm.org>>
Subject: Re: [llvm-dev] Enable vectorizer-maximize-bandwidth by default?

If you care about such hardware, please run benchmarks with the flag?

Dehao has made this flag available. It is important that those who care about
particular hardware provid ebenchmark results. Not everyone in the community
will have access to particular hardware variants.

On Tue, May 30, 2017 at 1:14 AM Flamedoge <code.kchoi at
gmail.com<mailto:code.kchoi at gmail.com>> wrote:
Thank you for running these.

May I suggest testing on AVX2 capable hardware? That would be Intel Haswell, AMD
Carrizo and up.
I'm not sure what "vectorizer-maximize-bandwidth" implies, but
doubling the vector lanes may help light up parallel regions.

Kevin

On Tue, May 30, 2017 at 12:58 AM, Chandler Carruth via llvm-dev <llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote:
On Fri, May 19, 2017 at 4:01 PM Adam Nemet via llvm-dev <llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote:
I will run it on Cyclone/AArch64 next week.

FYI, we're still waiting on these Adam...

_______________________________________________
LLVM Developers mailing list
llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>
http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev

---------------------------------------------------------------------
Intel Israel (74) Limited

This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.
_______________________________________________
LLVM Developers mailing list
llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>
http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
---------------------------------------------------------------------
Intel Israel (74) Limited

This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
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Agabaria, Mohammed via llvm-dev

2017-Jun-12 10:41 UTC

head link

[llvm-dev] Enable vectorizer-maximize-bandwidth by default?

Guys, Just to clarify that with the current fix in SLM there is no need to wait
for other issues to be fixed (minor issue).
So you can move on with your patch.

From: Agabaria, Mohammed
Sent: Wednesday, June 07, 2017 15:24
To: Zaks, Ayal <ayal.zaks at intel.com>; Chandler Carruth <chandlerc at
gmail.com>; Flamedoge <code.kchoi at gmail.com>; Dehao Chen <dehao
at google.com>
Cc: llvm-dev <llvm-dev at lists.llvm.org>
Subject: RE: [llvm-dev] Enable vectorizer-maximize-bandwidth by default?

Guys I have uploaded a fix on phabricator which fix the issue in SLM:
https://reviews.llvm.org/D33983

From: Zaks, Ayal
Sent: Tuesday, June 06, 2017 22:32
To: Chandler Carruth <chandlerc at gmail.com<mailto:chandlerc at
gmail.com>>; Agabaria, Mohammed <mohammed.agabaria at
intel.com<mailto:mohammed.agabaria at intel.com>>; Flamedoge
<code.kchoi at gmail.com<mailto:code.kchoi at gmail.com>>; Dehao
Chen <dehao at google.com<mailto:dehao at google.com>>
Cc: llvm-dev <llvm-dev at lists.llvm.org<mailto:llvm-dev at
lists.llvm.org>>
Subject: RE: [llvm-dev] Enable vectorizer-maximize-bandwidth by default?

Chandler> Have you considered contributing these benchmarks to the LLVM test
suite?

These benchmarks are not ours to contribute; they’re from the EEMBC standard,
whose availability is similar in nature to that of SPEC.

From: llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org] On Behalf Of Chandler
Carruth via llvm-dev
Sent: Tuesday, May 30, 2017 23:07
To: Agabaria, Mohammed <mohammed.agabaria at
intel.com<mailto:mohammed.agabaria at intel.com>>; Flamedoge
<code.kchoi at gmail.com<mailto:code.kchoi at gmail.com>>; Dehao
Chen <dehao at google.com<mailto:dehao at google.com>>
Cc: llvm-dev <llvm-dev at lists.llvm.org<mailto:llvm-dev at
lists.llvm.org>>
Subject: Re: [llvm-dev] Enable vectorizer-maximize-bandwidth by default?

On Tue, May 30, 2017 at 1:40 AM Agabaria, Mohammed via llvm-dev <llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote:
We’re seeing nice improvements but also significant degradations on IA, which we
would like to investigate before the patch is committed.

Major degradations we see:

networking
   ip_pktcheckb1m          -6.80 %
   ip_pktcheckb2m          -6.74 %
   ip_pktcheckb4m          -7.57 %
   ip_pktcheckb512k       -6.58 %
Telecom
   autcor00data_1          -78.02 %
   autcor00data_2          -76.80 %
   autcor00data_3          -77.00 %
(on Atom)

We still working on creating reproducers.
In general we support this patch, just want to have a chance to investigate the
issues. We need a few days for that.

I mean, OK... but keep in mind that Dehao's original email went out over a
week ago, so this patch has already been held up a while. As these benchmarks
aren't readily available, we also can't do anything to help until a test
case is posted.

Have you considered contributing these benchmarks to the LLVM test suite?

From: llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org] On Behalf Of Chandler
Carruth via llvm-dev
Sent: Tuesday, May 30, 2017 11:27
To: Flamedoge <code.kchoi at gmail.com<mailto:code.kchoi at
gmail.com>>; Dehao Chen <dehao at google.com<mailto:dehao at
google.com>>
Cc: llvm-dev <llvm-dev at lists.llvm.org<mailto:llvm-dev at
lists.llvm.org>>
Subject: Re: [llvm-dev] Enable vectorizer-maximize-bandwidth by default?

If you care about such hardware, please run benchmarks with the flag?

Dehao has made this flag available. It is important that those who care about
particular hardware provid ebenchmark results. Not everyone in the community
will have access to particular hardware variants.

On Tue, May 30, 2017 at 1:14 AM Flamedoge <code.kchoi at
gmail.com<mailto:code.kchoi at gmail.com>> wrote:
Thank you for running these.

May I suggest testing on AVX2 capable hardware? That would be Intel Haswell, AMD
Carrizo and up.
I'm not sure what "vectorizer-maximize-bandwidth" implies, but
doubling the vector lanes may help light up parallel regions.

Kevin

On Tue, May 30, 2017 at 12:58 AM, Chandler Carruth via llvm-dev <llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote:
On Fri, May 19, 2017 at 4:01 PM Adam Nemet via llvm-dev <llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote:
I will run it on Cyclone/AArch64 next week.

FYI, we're still waiting on these Adam...

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