Generation of LIR has the subtle invariant that fixed intervals containing oops should never be alive across a safepoint.  The current logic that checks this is too weak.
Posted Date : 2009-04-08 19:53:27.0

N/A

The purpose of the assert is to check that there are no live intervals using fixed registers spanning a safepoint that aren't used by the op itself.  So we walk to current op id and find all the fixed intervals that are live across the current op.  Then we scan the op itself to see if it is using that interval.  If it is then the interval is safe.  If it's not then there's a bug because that fixed interval won't show up in an oop map.  Basically we're checking that the set of live fixed intervals is subset of the intervals used by the op.
Posted Date : 2009-04-08 19:53:27.0

http://hg.openjdk.java.net/jdk7/hotspot-comp/hotspot/rev/a134d9824964
Posted Date : 2009-04-17 03:53:55.0