Also, UseCompressedOops was supposed to be turned on by default in hs14, bug somehow that changeset was lost.
Coleen Phillimore - Sun Microsystems wrote:
> On 09/26/08 20:07, Vladimir Kozlov wrote:
>> First, UseParNewGC does not work with compressed oops:
> It is supposed to. Is it broken or just not performant?
>> pf-t5120-1% gamma -XX:InlineSmallCode=1400 -XX:FreqInlineSize=210 -XX:+UseCompressedOops -XX:+AggressiveOpts -XX:ParallelGCThreads=40 -XX:+UseLargePages -XX:LargePageSizeInBytes=256m -XX:+AlwaysPreTouch -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -Xmx28g -Xms28g -Xmn22g -XX:+UseParNewGC -XX:+PrintTenuringDistribution -Xss256k -cp jbb.jar:check.jar spec.jbb.JBBmain
>> Exception in thread "main" java.lang.ClassCastException: java.util.LinkedHashMap$Entry cannot be cast to java.util.Map$Entry
>> at java.security.Provider.ensureLegacyParsed(Provider.java:536)
6760773: UseCompressedOops is broken with UseParNewGC
Summary: sparc code for gen_subtype_check was doing an ld for a compressed oop with the sign bit set so not comparing, leading to a ClassCastException.
Reviewed-by: phh, never, acorn, kvn, xlu
Fixed in b08, I think.