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

Civlin, Jan jan.civlin at intel.com
Fri Oct 9 21:57:30 UTC 2015


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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