C2Compiler crash 6.0 u17

We are observing C2Compiler crashes frequently on Solaris 10 amd64 with following stack trace :


t@24 (l@24) terminated by signal SEGV (Segmentation Fault)
0xfffffd7ffb526541: build_loop_late_post+0x1001: movq 0x0000000000000008(%rbx),%r8
(dbx) where
current thread: t@24
=>[1] PhaseIdealLoop::build_loop_late_post(0xfffffd7fe1451a48, 0xf0b5170, 0x0, 0x0, 0x0, 0xf881020), at 0xfffffd7ffb526541
  [2] PhaseIdealLoop::build_loop_late(0x0, 0x0, 0x0, 0x0, 0x0, 0x0), at 0xfffffd7ffb609250
  [3] PhaseIdealLoop::PhaseIdealLoop(0x0, 0x0, 0x0, 0x0, 0x0, 0x0), at 0xfffffd7ffbb0323a
  [4] Compile::Optimize(0x0, 0x0, 0x0, 0x0, 0x0, 0x0), at 0xfffffd7ffb639497
  [5] Compile::Compile(0x0, 0x0, 0x0, 0x0, 0x0, 0x0), at 0xfffffd7ffb83a62d
  [6] C2Compiler::compile_method(0x0, 0x0, 0x0, 0x0, 0x0, 0x0), at 0xfffffd7ffb636d77
  [7] CompileBroker::invoke_compiler_on_method(0x0, 0x0, 0x0, 0x0, 0x0, 0x0), at 0xfffffd7ffb6368d6
  [8] CompileBroker::compiler_thread_loop(0x0, 0x0, 0x0, 0x0, 0x0, 0x0), at 0xfffffd7ffb6bfd68
  [9] compiler_thread_entry(0x0, 0x0, 0x0, 0x0, 0x0, 0x0), at 0xfffffd7ffb6bc199
  [10] JavaThread::thread_main_inner(0x0, 0x0, 0x0, 0x0, 0x0, 0x0), at 0xfffffd7ffb67b08d
  [11] JavaThread::run(0x0, 0x0, 0x0, 0x0, 0x0, 0x0), at 0xfffffd7ffb67ae3a
  [12] java_start(0x0, 0x0, 0x0, 0x0, 0x0, 0x0), at 0xfffffd7ffbb6d619
  [13] _thr_setup(0x0, 0x0, 0x0, 0x0, 0x0, 0x0), at 0xfffffd7ffcd50edb
  [14] _lwp_start(0x0, 0x0, 0x0, 0x0, 0x0, 0x0), at 0xfffffd7ffcd51110

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This crash happens only sometimes but not very infrequent. May be once a day in tinderbox.

Crash location :
Hostname : x1-zone2:

Core file location :
/opt/tinderbox_64/i386/iplanet.core/ias/server/work/B1/SunOS5.9_i86pc_DBG.OBJ/https-test/config/core