Mode : -Xcomp
Platforms : Solsparc 5.6
JAVA_HOME : /net/sqesvr.eng/export/vsn/VM/merlin/weekahead/jdk/latest/{OS}

Steps to reproduce
1) cd /net/sqesvr.eng/export/vsn/GammaBase/Bugs/{Bugid}
2) sh doit {JAVA_HOME}

{OR}

Make a runList.dat file with the following testcases and run next command-line.

$TESTBASE/jck/jck-13a/JCK/javatest.jar;$TESTBASE/jck/jck-13a/JCK/classes javasoft.sqe.tests.api.java.lang.StringIndexOutOfBoundsException.serial.ConstructorTests
$TESTBASE/jck/jck-13a/JCK/javatest.jar;$TESTBASE/jck/jck-13a/JCK/classes javasoft.sqe.tests.api.java.lang.StringBuffer.NewTests

${JAVA_HOME}/bin/java -server -Xcomp -Xss4m -classpath /net/sqesvr/export/vsn/VM/testbase/runThese/classes $* runThese -thread 1 -repeat 1 -iter 1 -D:gc=5 -D:TESTBASE=/net/sqesvr/export/vsn/VM/testbase/runThese/tests -runList runList.dat

Output:
java version "1.4.0-beta_refresh"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-beta_refresh-b66)
Java HotSpot(TM) Server VM (build 20010606101740.jcoomes.baseline-debug, compiled mode)

[Enter:javasoft.sqe.tests.api.java.lang.StringIndexOutOfBoundsException.serial.ConstructorTests]
Checking for assertion
Creating StreamObject from object
Verifying for JDK version : 1.1
Creating the spec class
Verifying the constraints on the serial fields
Verifying for JDK version : 1.2
Creating the spec class
Verifying the constraints on the serial fields
ConstructorTest0001 passed
ConstructorTest0001: Passed.
Creating StreamObject from object
Verifying for JDK version : 1.1
Creating the spec class
Verifying the constraints on the serial fields
Verifying for JDK version : 1.2
Creating the spec class
Verifying the constraints on the serial fields
ConstructorTest0002 passed
ConstructorTest0002: Passed.
Checking for assertion
Creating StreamObject from object
Verifying for JDK version : 1.1
Creating the spec class
Verifying the constraints on the serial fields
Verifying for JDK version : 1.2
Creating the spec class
Verifying the constraints on the serial fields
ConstructorTest0003 passed
ConstructorTest0003: Passed.
Creating StreamObject from object
Verifying for JDK version : 1.1
Creating the spec class
Verifying the constraints on the serial fields
Verifying for JDK version : 1.2
Creating the spec class
Verifying the constraints on the serial fields
ConstructorTest0004 passed
ConstructorTest0004: Passed.
Creating StreamObject from object
Verifying for JDK version : 1.1
Creating the spec class
Verifying the constraints on the serial fields
Verifying for JDK version : 1.2
Creating the spec class
Verifying the constraints on the serial fields
ConstructorTest0005 passed
ConstructorTest0005: Passed.
STATUS:Passed.tests: 5; passed: 5
#Passed; javasoft.sqe.tests.api.java.lang.StringIndexOutOfBoundsException.serial.ConstructorTests; (1,1,0,0,0)
[Exit:javasoft.sqe.tests.api.java.lang.StringIndexOutOfBoundsException.serial.ConstructorTests]
......................................
[Enter:javasoft.sqe.tests.api.java.lang.StringBuffer.NewTests]
#
# HotSpot Virtual Machine Error, assertion failure
# Please report this error at
# http://java.sun.com/cgi-bin/bugreport.cgi
#
# Java VM: Java HotSpot(TM) Server VM (20010606101740.jcoomes.baseline-debug compiled mode)
#
# assert(old_idx, "must find old")
#
# Error ID: /export/imgr_home/ws/20010606101740.jcoomes.baseline/src/share/vm/opto/postaloc.cpp, 87 [ Patched ]
#
# Problematic Thread: prio=5 tid=0x11ac78 nid=0xb runnable
#
Dumping core....
Abort - core dumped

NOTE: Test passes in -Xint and -Xmixed modes.