While testing the G1 workspace, I came across the following failure:

# To suppress the following error report, specify this argument
# after -XX: or in .hotspotrc: SuppressErrorAt=/generateOopMap.cpp:947
#
# An unexpected error has been detected by Java Runtime Environment:
#
# Internal Error (/java/east/u2/ap31282/hs-g1-fixes/src/share/vm/oops/generateO
opMap.cpp, 947 [ Patched ]), pid=14729, tid=2
#
# Java VM: Java HotSpot(TM) 64-Bit Server VM (1.7.0-internal-fastdebug mixed mod
e)
#
# Error: assert(bb->_end_bci + bc_len == bb[1]._bci,"unmatched bci info in basic
block")
# An error report file with more information is saved as hs_err_pid14729.log
#
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
#

It's very easily reproduced (i.e., it fails every time) with the G1 workspace (G1 doesn't have to be enabled; ParallelGC also causes it too) and running the eclipse benchmark of the dacapo test suite.

Here's how you reproduce it. You need your own copy of the dacapo test suite (it writes a lot to disk, so you do need your copy on a directory you can write to). Copy the jar file from here:

/java/east/u2/ap31282/gc_test_suite/dacapo/dacapo-2006-10.jar

Then, run it this way:

java -d64 -XX:+PrintGCTimeStamps -XX:+PrintGCDetails -jar dacapo-2006-10.jar -s default eclipse

I have reproduced it on 4 different platforms:

Solaris SPARC C2 64-bit
Solaris AMD64 C2
Linux AMD64 C2 64-bit
Linux AMD64 C2

I was not able to reproduce it with a reasonably up-to-date non-G1 workspace.