Shark generic inliner

[Gary Benson]

Hi all,

After messing around with inlining accessor methods and empty methods
last week I realised there are a lot of methods that are generally
inlinable.  Over the last few days I've been experimenting with a more
generic inliner, which I'm about to commit.  Quick and dirty SPECjvm98
numbers (not produced in compliance with the SPECjvm98 run rules and
so not comparable with SPECjvm98 metrics) look like this:

              Original   Inlining    Speedup
  compress      11.676     11.680       0.0%
  jess           8.907      8.438       5.3%
  db            16.604     16.300       1.8%
  javac         13.770     13.041       5.3%
  mpegaudio      8.137      7.857       3.4%
  mtrt           7.817      7.833      -0.2%
  jack          10.116      9.947       1.7%

The numbers aren't great, but they're better than nothing.  I suspect
that's because the number of methods available for inlining is small
compared with the number of methods in total.  Partly this is down to
the Java language itself -- a lot of calls are virtual or interface,
and most of these can't be inlined -- and partly this is because of
restrictions in Shark which I'm going to see if I can work around.

I'm not going to attach a patch to this message.  The inliner itself
is small, 700 lines or so, but to make it work I needed to refactor
a lot of SharkBlock and SharkState.  The code is all the same, just
in different places.

The main part of the refactoring is that I split SharkBlock into three
classes, one of them new.  The new class heirachy is as follows:

  SharkBlock (in sharkBlock.[ch]pp)
   +- SharkTopLevelBlock (in sharkTopLevelBlock.[ch]pp)
   +- SharkInlineBlock (in sharkInliner.cpp)

SharkBlock is all the common code, SharkTopLevelBlock extends that
for non-inlined blocks, and SharkInlineBlock extends that for inlined
blocks.

The other part of the refactoring is that all the code in the slightly
odd class SharkTrackingState is now in SharkState, and the two other
subclasses of SharkState (SharkEntryState and SharkPHIState) have been
moved into the files in which they're used (sharkFunction.cpp and
sharkTopLevelBlock.cpp respectively).

Enjoy!

Cheers,
Gary
  
-- 
http://gbenson.net/