RFR(M): 8181211: C2: Use profiling data to optimize on/off heap unsafe accesses

[Roland Westrelin]

Hi Vladimir,

Thanks for the test results.

> SA jtreg tests failed (tests ran in 2 modes: -Xmixed and -Xcomp):
>
> compiler/ciReplay/TestSAServer.java
> serviceability/sa/TestPrintMdo.java

There's a missing entry in the vmStructs. Once fixed, I verified both
tests pass now.

> Some tests failed because you moved RM:
>
> http://cr.openjdk.java.net/~roland/8181211/webrev.00/src/share/vm/oops/method.cpp.udiff.html

That RM can lead to a dandling pointer if the outputStream argument is
not tty and the buffer that is passed grows under the RM. Anyway, it may
be better to leave that RM in in that change and take care of the bug
separately?

Roland.