http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2017-January/025231.html

Java 9 has JEP 158: Unified JVM Logging.
This JEP describes that existing 'tty->print...' logging should use unified logging as output. However, JIT compilers does not seem to use it.

-XX:PrintCompilation, -XX:PrintInlining, and -XX:+PrintIntrinsics should be migrated to Unified Logging.