RFR (S) 8140650: (preliminary) Method::is_accessor should cover getters and setters for all types (original) (raw)

Aleksey Shipilev aleksey.shipilev at oracle.com
Wed Oct 28 15:31:46 UTC 2015

Hi,

I have been reading the compiler code recently to check if setters/getters are actually treated specially in inline policy. They do, and inliner relies on Method::is_accessor to detect them.

But then I realized that Method::is_accessor implementation only accepts the specific shapes of getters, and completely ignores setters (contrary to what is spelled in the "doc" comment!): https://bugs.openjdk.java.net/browse/JDK-8140650

This makes compilers to ignore many trivial methods that we might otherwise inline when all other inline hints have failed. With that in mind, I did a proof-of-concept change, which passes JPRT and a new compiler-specific regression test: http://cr.openjdk.java.net/~shade/8140650/webrev.00/

I'll run more testing, after we figure the fate for interpreter.cpp change. It is prompted by Zero's fast accessor implementation that only accepts the specific getter shape. Now, we can go three routes: a) Ignore the issue, and keep Method::is_simple_accessor; b) Fix Zero's fast accessor to accept all the shapes. c) Remove fast accessors from Zero (I see UseFastAccessorMethods is marked as obsolete), and thus probably remove the notion of "accessor" from interpreter completely (?);

Current patch does (a), and I'm leaning to keep it that way, letting Zero to handle more in future. If we care more about Zero, we might go for (b) -- although it seems to deserve a separate follow-up RFE. And if we don't, we can go for (c).

Thoughts?

Thanks, -Aleksey

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