Speed Impact experiment on GCJ
Andrew Haley
aph@redhat.com
Wed Feb 15 16:23:00 GMT 2006
Thomas Hallgren writes:
> Andrew Haley wrote:
>
> [thhal@localhost gcjtest]$ time java -server Client task.test servers.d result.d
>
> real 0m0.510s
> user 0m0.073s
> sys 0m0.393s
>
> 200.0 39
> 300.0 1
> 400.0 0
> 500.0 1
>
> REMARK: Obviously, the JIT discovers that the loop is not really a loop sometime
> during the first iterations and decides to optimize pretty hard...
Indeed. :-)
One thing we've all laearned about benchmarks: for a test to be in any
way meaningful it has to actually *do* something.
For what it's worth, I was quite suprised that gcj didn't spot the
same opportunity. Maybe this is part of the value range propagation
optimizations that aren't yet in core gcc.
Andrew.
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