The issue is reproduced also on 32 client sparc.
To reproduce run:
/net/sqenfs-1.sfbay/export1/jdk/re/6u18/promoted/all/b01/binaries/solaris-sparcv9/fastdebug//bin/java -server -d64 -XX:-ShowMessageBoxOnError -Xverify:all -XX:+CompileTheWorld -XX:CompileTheWorldStartAt=1314 -XX:CompileTheWorldStopAt=1414 -Xbootclasspath/p:/net/sqenfs-1.sfbay/export1/comp/vm/testbase/ctw/build/../jars/ibiblio/maven2/org/codehaus/groovy/groovy-all-jdk14/1.6.0/groovy-all-jdk14-1.6.0.jar

----------------------------------------------------------------------------
-->/net/sqenfs-1.sfbay/export1/jdk/re/6u18/promoted/all/b01/binaries/solaris-sparc/fastdebug//bin/java -client -XX:-ShowMessageBoxOnError -Xverify:all -XX:+CompileTheWorld -XX:CompileTheWorldStartAt=1314 -XX:CompileTheWorldStopAt=1414 -Xbootclasspath/p:/net/sqenfs-1.sfbay/export1/comp/vm/testbase/ctw/build/../jars/ibiblio/maven2/org/codehaus/groovy/groovy-all-jdk14/1.6.0/groovy-all-jdk14-1.6.0.jar
VM option '-ShowMessageBoxOnError'
VM option '+CompileTheWorld'
VM option 'CompileTheWorldStartAt=1314'
VM option 'CompileTheWorldStopAt=1414'
Warning: Cannot open log file: hotspot.log
Warning: Forcing option -XX:LogFile=/tmp//hs_pid1041.log
CompileTheWorld : Compiling all classes in /net/sqenfs-1.sfbay/export1/comp/vm/testbase/ctw/jars/ibiblio/maven2/org/codehaus/groovy/groovy-all-jdk14/1.6.0/groovy-all-jdk14-1.6.0.jar

Preloading failed for (13) groovy/grape/GrapeIvy$_getDependencies_closure2
Preloading failed for (17) groovy/grape/GrapeIvy
Preloading failed for (268) groovy/servlet/GroovyServlet$1
Preloading failed for (274) groovy/servlet/ServletBinding$ServletOutput
Preloading failed for (275) groovy/servlet/ServletBinding
Preloading failed for (276) groovy/servlet/ServletCategory
Preloading failed for (277) groovy/servlet/TemplateServlet$TemplateCacheEntry
Preloading failed for (525) groovy/ui/InteractiveShell
Preloading failed for (598) groovy/util/AntBuilder
Preloading failed for (602) groovy/util/CliBuilder$_option_closure1
Preloading failed for (603) groovy/util/CliBuilder
Preloading failed for (686) groovy/util/OptionAccessor
CompileTheWorld (1314) : groovyjarjarbackport/java/util/concurrent/locks/ReentrantLock$Sync
# To suppress the following error report, specify this argument
# after -XX: or in .hotspotrc: SuppressErrorAt=/assembler_sparc.hpp:845
#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/BUILD_AREA/jdk6_18/hotspot/src/cpu/sparc/vm/assembler_sparc.hpp:845), pid=1041, tid=7
# Error: assert(nbits == 32 || -(1 << nbits-1) <= x && x < ( 1 << nbits-1),"value out of range")
#
# JRE version: 6.0_18-b01
# Java VM: Java HotSpot(TM) Client VM (16.0-b08-fastdebug mixed mode solaris-sparc )
# An error report file with more information is saved as:
# /tmp/hs_err_pid1041.log
#
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
#
Current thread is 7
Dumping core ...
Abort