The changes in JDK-8336999 introduced a regression of around 4% in C2 execution time across the DaCapo 23 benchmarks, see the detailed results in the attached spreadsheet.

The regression was found on linux-x64 by comparing C2's bytes/s as reported by -XX:+CITime (averaged over a number of repetitions) before and after the integration of JDK-8336999, using the JVM flags -Xbatch -XX:-TieredCompilation for stability.