Request for reviews (L): 7125896: Eliminate nested locks
vladimir.kozlov at oracle.com
Thu Dec 29 13:20:09 PST 2011
7125896: Eliminate nested locks
Nested locks elimination done before lock nodes expansion by looking for outer
locks of the same object. Commoning (GVN) of BoxLock nodes is switched off
because nested locks elimination requires separate BoxLock node for each locked
region to generated correct debug info for deoptimization. As result there could
be merges (and Phi nodes) of BoxLock nodes. One such merge generated by
ciTypeFlow (cloning loop head) is avoided but there could be other cases so new
code is added to handle it.
New code is under new product flag EliminateNestedLocks.
Also added missed KILL effect for box register in fastlock and fastunlock mach
Tested with full CTW, nsk, jtreg tests, refworkload.
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