Mailing-List: contact harmony-dev-help@incubator.apache.org; run by ezmlm
Precedence: bulk
Reply-To: harmony-dev@incubator.apache.org
Received-SPF: pass (herse.apache.org: domain of gcjhd-harmony-dev@m.gmane.org
 designates 80.91.229.2 as permitted sender)
To: harmony-dev@incubator.apache.org
From: "Natalya Golovleva" <natalya.golovleva@gmail.com>
Subject: [drlvm][jit][ia-32]escape analysis based scalar replacement
Date: Fri, 17 Nov 2006 17:21:26 +0600
Lines: 47
Message-ID: <ejk5vn$9js$1@sea.gmane.org>
Sender: news <news@sea.gmane.org>

Hello all,


JIT Development Tasks list among other tasks contains new optimization - 
EA-based scalar replacement.


EA determinates for every reference object used in the method its state: 
local, argument escaped and global escaped.

Escape analysis (EA) is already committed to harmony.


Scalar replacement optimization may be done for local objects (class 
instances and arrays) that satisfy to:

-        class should not have finalizer, class instance initializer should 
not have side effects;

-        optimized array may have only one array element usage.


I am going to implement EA-based scalar replacement for IA-32.


The proposal is:

  1.. to perform scalar replacement for specified above local objects.
  2.. using devirtualization and inlining change method code to create the 
object only when it is used as a parameter of virtual call and perform 
scalar replacement for branches with inlined direct calls.


Any comments are welcome.


Thank you,

Natalya.