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From: David Lamb <dalamb@cs.queensu.ca>
Newsgroups: comp.lang.java.programmer
Subject: Re: Java processors
Date: Mon, 16 Jul 2012 13:22:21 -0400
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On 08/07/2012 8:56 PM, Lew wrote:
> It wouldn't make sense to keep old compilations around. They're based on
> runtime conditions that by definition have changed or the old one would
> still be valid.

It has been a long time since I worked on optimizing compiler 
technology, but my fragmented memories suggest that it's not "all or 
nothing" with regard to what information you need for optimization. Some 
intra-procedural data flow analysis remains valid even if 
inter-procedural or inter-class information changes, and some 
optimization only depend on local information.