[13] RFR (S): 8188133: C2: Static field accesses in clinit can trigger deoptimizations

[Vladimir Ivanov]

http://cr.openjdk.java.net/~vlivanov/8188133/webrev.00
https://bugs.openjdk.java.net/browse/JDK-8188133

The test case in the bug demonstrates a pathological case with 
long-running static initializer: though it's allowed to access static 
fields from the thread performing the initialization, C2 can't prove 
that in general.

While solving the general problem doesn't seem worth the effort 
(requires barriers on method entries), I propose to extend the logic to 
cover simple cases: when static initializer is the root of the 
compilation, all accesses to static fields of the corresponding class 
are allowed. It extends the coverage to all inlinees from OSR 
compilation of clinit.

Testing: hs-precheckin-comp, tier1-5

Best regards,
Vladimir Ivanov