This PR implements zeros and population count instructions: `clz`/`clzw`/`ctz`/`ctzw`/`cpop`/`cpopw`. New C2 instructions are covered by the following JTREG tests: - test/hotspot/jtreg/compiler/codegen/Test6823354.java - test/hotspot/jtreg/compiler/codegen/Test7100757.java - test/hotspot/jtreg/compiler/codegen/Test8005033.java ------------- Commit messages: - 8279996: riscv: RVB: Add zeros/population count instructions Changes: https://git.openjdk.java.net/riscv-port/pull/45/files Webrev: https://webrevs.openjdk.java.net/?repo=riscv-port&pr=45&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8279996 Stats: 143 lines in 6 files changed: 116 ins; 5 del; 22 mod Patch: https://git.openjdk.java.net/riscv-port/pull/45.diff Fetch: git fetch https://git.openjdk.java.net/riscv-port pull/45/head:pull/45 PR: https://git.openjdk.java.net/riscv-port/pull/45