RFR: 8220502: Inefficient pre-sizing of PhiResolverState arrays in c1_LIRGenerator

Claes Redestad claes.redestad at oracle.com
Wed Mar 13 11:03:24 UTC 2019


Hi,

the PhiResolverState arrays are pre-sized to the maximum possible number
of nodes that can be put into them, which when instrumenting turns out
to be quite excessive. By not pre-sizing to the theoretical maximum I
can measure a substantial improvements in calling methods.

Webrev: http://cr.openjdk.java.net/~redestad/8220502/open.00/
Bug:    https://bugs.openjdk.java.net/browse/JDK-8220502

Testing: tier1-3

On a set of startup and footprint benchmarks, 60% of collected metrics
show 0.2-2% statistically significant improvements, with no
regression on any metric.

Thanks!

/Claes


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