The following heap parameters cause "zero based Compressed Oops" to be used, while "zero based Compressed Oops, 32-bits Oops" are expected:

.../solaris-sparcv9//bin/java -d64 -server -Xmixed -XX:+UseSerialGC -XX:ObjectAlignmentInBytes=8 -Xmx32m -XX:MaxPermSize=32m -XX:+UnlockDiagnosticVMOptions -XX:+PrintCompressedOopsMode -version

heap address: 0x00000007fc000000, size: 64 MB, zero based Compressed Oops

It is specific to solaris-sparcv9.