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

[Chandler Carruth via llvm-dev]

Does the regression seem acceptable to you? Have you done any analysis of
what changed and why it regresses?

On Thu, Jun 1, 2017 at 4:47 AM Nema, Ashutosh <Ashutosh.Nema at amd.com> wrote:

> Hi,
>
>
>
> We enabled “vectorizer-maximize-bandwidth” and ran SPEC CPU2006
> (base,rate) on Ryzen 8 core, 16 copies with below config:
>
>
>
> Base: -m64 -O3 -march=znver1 -mavx2
>
> Base + VMB: -m64 -O3 -march=znver1 -mavx2  -mllvm
> -vectorizer-maximize-bandwidth
>
>
>
> There’s a small uplift for gcc and some small regression for sjeng. Others
> are within noise levels.
>
>
>
> CPU2006 Results:
>
> Benchmark
>
> Base/(Base + VMB)
>
> 400.perlbench
>
> 1
>
> 401.bzip2
>
> 1
>
> 403.gcc
>
> 1.01517
>
> 429.mcf
>
> 1.00222
>
> 445.gobmk
>
> 1
>
> 456.hmmer
>
> 1
>
> 458.sjeng
>
> 0.98641
>
> 462.libquantum
>
> 1
>
> 464.h264ref
>
> 1.01005
>
> 471.omnetpp
>
> 1.00187
>
> 473.astar
>
> 1
>
> 483.xalancbmk
>
> 1.00149
>
> 433.milc
>
> 1
>
> 444.namd
>
> 1
>
> 447.dealII
>
> 1
>
> 450.soplex
>
> 1
>
> 453.povray
>
> 1.00515
>
> 470.lbm
>
> 1
>
> 482.sphinx3
>
> 1
>
>
>
> *  Ratio more than 1 indicates vectorizer-maximize-bandwidth is improving
> the performance
>
> *  Ratio less than 1 indicates vectorizer-maximize-bandwidth is regressing
> the performance.
>
> *  Ratio 1 indicates no change.
>
>
>
> Regards,
>
> Ashutosh
>
>
>
> *From:* llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org] *On Behalf Of *Adam
> Nemet via llvm-dev
> *Sent:* Tuesday, May 30, 2017 9:47 PM
> *To:* Chandler Carruth <chandlerc at gmail.com>
>
>
> *Cc:* llvm-dev <llvm-dev at lists.llvm.org>
> *Subject:* Re: [llvm-dev] Enable vectorizer-maximize-bandwidth by default?
>
>
>
>
>
> On May 30, 2017, at 12:58 AM, Chandler Carruth <chandlerc at gmail.com>
> 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…
>
> I was going to test spec but this does not seem to trigger on spec
> according to Dehao, so there is really no reason for me to test this.  We
> have some spec perf bots that test trunk; if there is some unexpected
> regression we should pick it up.  Sorry for not being explicit about this.
>
>
>
> Adam
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20170601/d6da8614/attachment-0001.html>