RFR(M): 8024069: replace_in_map() should operate on parent maps

Christian Thalinger christian.thalinger at oracle.com
Tue Oct 15 11:50:15 PDT 2013

On Oct 12, 2013, at 2:31 PM, Roland Westrelin <roland.westrelin at oracle.com> wrote:

> The improved type coming from a type check when it is done inside an inlined method may be lost once compilation exits from the inlinee because GraphKit::replace_in_map() doesn't update the maps of caller methods.
> When updating the parent maps, the replacement must be safe. This is done 1) by following the control edges to check that the control of the inlinee's map post dominate the control of the parent's maps 2) not doing any update in parent maps if the replace_in_map is called inside a PreserveJVMState block because PreserveJVMState doesn't do a deep copy of the caller states.

What if we would do a deep-clone?  Are there any potential performance or memory issues?

> The update itself must be done in the exits maps of the Parsers of the caller. I've added code to chain them together so that replace_in_map can iterate over the Parsers of callers.
> http://cr.openjdk.java.net/~roland/8024069/webrev.00/
> Roland.

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