RFR: 8139340: SuperWord enhancement to support vector conditional move (CMovVD ) on Intel AVX cpu.

[Civlin, Jan]

Please review this patch.


Hi All,

We would like to contribute the SuperWord enhancement  to support vector conditional move (CMovVD ) on Intel AVX cpu.
The contribution Bug ID:  8139340.

Please review this patch:



Bug-id:            https://bugs.openjdk.java.net/browse/JDK-8139340

webrev:           http://cr.openjdk.java.net/~iveresov/vector-cmove/webrev.00/


Description:
SuperWord enhancement  to support vector conditional move (CMovVD) on Intel AVX cpu.
The SuperWord optimization bails out on counted loops that contain any conditional statement other than the loop exit, and this prevents vectorization of many compute bound loops.
The proposed enhancement enables generation of CMovD on demand (-XX:+UseCMov), and further  vectorization of CMovD (into CMovVD ) in SuperWord optimization.

The performance gain observed on a simplified Monte Carlo Option Calculation was up to 2x speed-up.

Thank you,

Jan.


From: Igor Veresov [mailto:igor.veresov at oracle.com]
Sent: Friday, October 9, 2015 3:22 PM
To: Civlin, Jan
Cc: hotspot compiler; Vladimir Kozlov
Subject: Re: SuperWord enhancement to support vector conditional move (CMovVD ) on Intel AVX cpu.

Here it is: https://bugs.openjdk.java.net/browse/JDK-8139340

igor

On Oct 9, 2015, at 2:57 PM, Civlin, Jan <jan.civlin at intel.com<mailto:jan.civlin at intel.com>> wrote:

Thank you, Igor.
What is the RFR for this?

From: Igor Veresov [mailto:igor.veresov at oracle.com]
Sent: Friday, October 9, 2015 2:53 PM
To: Civlin, Jan
Cc: hotspot compiler; Vladimir Kozlov
Subject: Re: SuperWord enhancement to support vector conditional move (CMovVD ) on Intel AVX cpu.

Here the webrev: http://cr.openjdk.java.net/~iveresov/vector-cmove/webrev.00/

igor

On Oct 9, 2015, at 1:15 PM, Civlin, Jan <jan.civlin at intel.com<mailto:jan.civlin at intel.com>> wrote:

Igor,

Please create RFR and upload this patch. You may need to rename ancnav.js.remove_this_extention back to ancnav.js (I have to rename it for passing the mail server filters).

Description:
SuperWord enhancement  to support vector conditional move (CMovVD) on Intel AVX cpu.
The SuperWord optimization bails out on counted loops that contain any conditional statement other than the loop exit, and this prevents vectorization of many compute bound loops.
The proposed enhancement enables generation of CMovD on demand (-XX:+UseCMov), and further  vectorization of CMovD (into CMovVD ) in SuperWord optimization.

The performance gain observed on a simplified Monte Carlo Option Calculation was up to 2x speed-up.

Thank you,

Jan.

<webrev-r9162-9157.tar.bz2>

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