RFR(M) 8152496: Blended code generation

Berg, Michael C michael.c.berg at intel.com
Fri Mar 25 18:44:07 UTC 2016

Here is the webrev with the changes from below.



-----Original Message-----
From: Aleksey Shipilev [mailto:aleksey.shipilev at oracle.com] 
Sent: Thursday, March 24, 2016 11:32 AM
To: Christian Thalinger <christian.thalinger at oracle.com>; Berg, Michael C <michael.c.berg at intel.com>
Cc: hotspot-compiler-dev at openjdk.java.net
Subject: Re: RFR(M) 8152496: Blended code generation

On 03/24/2016 08:55 PM, Christian Thalinger wrote:
>> On Mar 24, 2016, at 7:50 AM, Berg, Michael C 
>> <michael.c.berg at intel.com <mailto:michael.c.berg at intel.com>> wrote:
>> Hi All,
>> I would like to contribute blended code generation.  On EVEX enabled 
>> platforms that have sufficient CPUID support, it is a boon to mix 
>> code generation to keep size manageable when emitting EVEX code, we 
>> can migrate compatible versions to AVX when resources allow, this 
>> enables an uplift of as much as 12% on known metrics such as those in 
>> SpecJvm2008. Reportable score uplift on a base run is enhanced 
>> nominally by 6%.
>> These changes uplift performance via 64-bit and 32-bit code 
>> generation generically wherever scalar or vector SIMD is present.

Oh wow.

>> Bug-id: https://bugs.openjdk.java.net/browse/JDK-8152496
>> webrev:
>> http://cr.openjdk.java.net/~mcberg/8152496/webrev.01/
>> <http://cr.openjdk.java.net/%7Emcberg/8152496/webrev.01/>

This is suspicious, should be 0x79?
  6187     emit_int8(79)

Only x86_32.ad changes, no x86_64.ad?

is_managed is cryptic, and probably deserves a comment.


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