deep recursion into PhaseIdealLoop::spinup: atg core dumped with fastdebug build

atg core dumped when running with 0921's fastdebug build in C2 mode on solaris x86

Test machine: jtg-lx50-2
# uname -a
SunOS jtg-lx50-2 5.9 Generic_112234-03 i86pc i386 i86pc
# /usr/j2se_b20/bin/java -server -version
java version "1.5.0-beta"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0-beta-b20)
Java HotSpot(TM) Server VM (build 20030921183238.robertg.baseline-fastdebug-debug, mixed mode)


JVM flags used: -server -XX:+DeoptimizeALot -XX:+SafepointALot

Fastdebug build is get from
/net/balvenie.sfbay/export/imgr_home/archive/main/master/2003/20030921183238.robertg.baseline

How to reproduce the problem:
1. telnet jtg-lx50-2.sfbay
2. export JAVA_HOME=<jdk installation>
3. execute the script
/net/jtgb4u4c.sfbay/export/sail8/bigapps/tests/runatg.ksh -server -XX:+DeoptimizeALot -XX:+SafepointALot

core file will be found under /bt/atg*/home within half an hour.

###@###.### 2003-09-24

# dbx /usr/j2se_b20/bin/java core
t@0 (l@7) terminated by signal SEGV (Segmentation Fault)
(dbx) where | more
  [1] Node::operator new(0x38, 0x3), at 0xdc66fad6
  [2] PhiNode::make_blank(0x885de14, 0x9c2e5e8), at 0xdc66874e
  [3] PhaseIdealLoop::spinup(0xd96fed88, 0xacfe974, 0x89d4990, 0x89d4abc, 0x885d
e14, 0x9c2e5e8, 0xd96fe830), at 0xdcc29ace

###@###.### 2003-09-24

Another snippet from stack trace:

  [1] PhaseIdealLoop::idom_no_update(0xd96aec88, 0x89fb5f0), at 0xdcc2b989
  [2] PhaseIdealLoop::spinup(0xd96aec88, 0x9d1f344, 0xac628c4, 0xac629f0, 0x89fb5f0, 0x89f8b28, 0xd96ae730), at 0xdcc29a24
  [3] PhaseIdealLoop::spinup(0xd96aec88, 0x9d1f344, 0xac628c4, 0xac629f0, 0xaa1bde0, 0x89f8b28, 0xd96ae730), at 0xdcc29b66
  [4] PhaseIdealLoop::spinup(0xd96aec88, 0x9d1f344, 0xac628c4, 0xac629f0, 0xaa1c354, 0x89f8b28, 0xd96ae730), at 0xdcc29b66
  [5] PhaseIdealLoop::spinup(0xd96aec88, 0x9d1f344, 0xac628c4, 0xac629f0, 0xaa1bde0, 0x89f8b28, 0xd96ae730), at 0xdcc29b66
......
......
  [98] PhaseIdealLoop::spinup(0xd96aec88, 0x9d1f344, 0xac628c4, 0xac629f0, 0xaa1c354, 0x89f8b28, 0xd96ae730), at 0xdcc29b66
  [99] PhaseIdealLoop::spinup(0xd96aec88, 0x9d1f344, 0xac628c4, 0xac629f0, 0xaa1bde0, 0x89f8b28, 0xd96ae730), at 0xdcc29b66
=>[100] PhaseIdealLoop::spinup(0xd96aec88, 0x9d1f344, 0xac628c4, 0xac629f0, 0xaa1c354, 0x89f8b28, 0xd96ae730), at 0xdcc29b66

###@###.### 2003-09-26