Request for review (L): 7071653: JSR 292: call site change notification should be pushed not pulled

[Rémi Forax]

Cool :)

Rémi

On 08/05/2011 03:32 PM, Christian Thalinger wrote:
> http://cr.openjdk.java.net/~twisti/7071653
>
> 7071653: JSR 292: call site change notification should be pushed not pulled
> Reviewed-by:
>
> Currently every speculatively inlined method handle call site has a
> guard that compares the current target of the CallSite object to the
> inlined one.  This per-invocation overhead can be removed if the
> notification is changed from pulled to pushed (i.e. deoptimization).
>
> I had to change the logic in TemplateTable::patch_bytecode to skip
> bytecode quickening for putfield instructions when the put_code
> written to the constant pool cache is zero.  This is required so that
> every execution of a putfield to CallSite.target calls out to
> InterpreterRuntime::resolve_get_put to do the deoptimization of
> depending compiled methods.
>
> I also had to change the dependency machinery to understand other
> dependencies than class hierarchy ones.  DepChange got the super-type
> of two new dependencies, KlassDepChange and CallSiteDepChange.
>
> Tested with JRuby tests and benchmarks, hand-written testcases, JDK
> tests and vm.mlvm tests.
>
> Here is the speedup for the JRuby fib benchmark (first is JDK 7 b147,
> second with 7071653).  Since the CallSite targets don't change during
> the runtime of this benchmark we can see the performance benefit of
> eliminating the guard:
>
> $ jruby --server bench/bench_fib_recursive.rb 5 35
>    0.883000   0.000000   0.883000 (  0.854000)
>    0.715000   0.000000   0.715000 (  0.715000)
>    0.712000   0.000000   0.712000 (  0.712000)
>    0.713000   0.000000   0.713000 (  0.713000)
>    0.713000   0.000000   0.713000 (  0.712000)
>
> $ jruby --server bench/bench_fib_recursive.rb 5 35
>    0.772000   0.000000   0.772000 (  0.742000)
>    0.624000   0.000000   0.624000 (  0.624000)
>    0.621000   0.000000   0.621000 (  0.621000)
>    0.622000   0.000000   0.622000 (  0.622000)
>    0.622000   0.000000   0.622000 (  0.621000)
>