RFR(L): 8074981 (Integer/FP scalar reduction optimization )

[Vladimir Kozlov]

We want to motivate people to migrate to new releases :)
If you mean loop reduction vectorization we can consider it after it is tested for some time in jdk9.

Vladimir

On 4/7/15 11:55 AM, Vitaly Davidovich wrote:
> Ok, thanks.  That makes sense for avx512 support, but I think having Michael's changes from this thread sooner would be
> nice as it's quite likely that users are already running java 8 on hardware where this may have benefit.  Java 9 is
> still ways away, and even when it's released, the migration process is not always quick (depending on the nature of
> major changes).  But, if backporting it is messy, it's probably not worth it.
>
> On Tue, Apr 7, 2015 at 2:38 PM, Vladimir Kozlov <vladimir.kozlov at oracle.com <mailto:vladimir.kozlov at oracle.com>> wrote:
>
>     Currently it is only jdk9. There are no plans to backport to 8u.
>     The thinking is that we will get jdk9 released when this hardware will be widely available.
>
>     Regards,
>     Vladimir
>
>     On 4/7/15 11:30 AM, Vitaly Davidovich wrote:
>
>         Hi Michael/Vladimir,
>
>         Out of curiosity, is this change and the out-for-review avx512 one going to be (or planned on being) backported
>         to java 8?
>
>         Thanks
>
>         On Tue, Apr 7, 2015 at 2:07 PM, Berg, Michael C <michael.c.berg at intel.com <mailto:michael.c.berg at intel.com>
>         <mailto:michael.c.berg at intel.__com <mailto:michael.c.berg at intel.com>>> wrote:
>
>              Please ignore this one its already checked in…____
>
>              __ __
>
>              *From:* hotspot-compiler-dev [mailto:hotspot-compiler-dev-__bounces at openjdk.java.net
>         <mailto:hotspot-compiler-dev-bounces at openjdk.java.net>
>              <mailto:hotspot-compiler-dev-__bounces at openjdk.java.net
>         <mailto:hotspot-compiler-dev-bounces at openjdk.java.net>>] *On Behalf Of *Berg, Michael C
>              *Sent:* Monday, March 16, 2015 2:18 PM
>              *To:* hotspot-compiler-dev at openjdk.__java.net <mailto:hotspot-compiler-dev at openjdk.java.net>
>         <mailto:hotspot-compiler-dev at __openjdk.java.net <mailto:hotspot-compiler-dev at openjdk.java.net>>
>              *Subject:* RFR(L): 8074981 (Integer/FP scalar reduction optimization )____
>
>              __ __
>
>              Hi All,____
>
>              __ __
>
>              We would like to contribute the Integer/FP scalar reduction optimization from Intel.____
>
>              The contribution is referenced as Bug ID 8074981 as a performance enhancement. ____
>
>              __ __
>
>              Please review this patch:____
>
>              Bug-id: https://bugs.openjdk.java.net/__browse/JDK-8074981
>         <https://bugs.openjdk.java.net/browse/JDK-8074981> ____
>
>              webrev: https://bugs.openjdk.java.net/__secure/attachment/26101/__webrev.zip
>         <https://bugs.openjdk.java.net/secure/attachment/26101/webrev.zip> ____
>
>              __ __
>
>              The optimization achieves as much as 2.3x on integer reductions and supports float and double precision
>              optimizations____
>
>              which also have significant optimization uplift an obey strict fp constraints.____
>
>              __ __
>
>              Nils Eliasson has offered to sponsor this patch.____
>
>              __ __
>
>              Thanks,____
>
>              __ __
>
>              -Michael____
>
>              __ __
>
>
>