On Tue, 7 Jan 2025 22:16:19 GMT, Francesco Nigro <d...@openjdk.org> wrote:
>> In PR #22928, UUID introduced long-based vectorized hexadecimal to string >> conversion, which can also be used in Integer::toHexString and >> Long::toHexString to eliminate table lookups. The benefit of eliminating >> table lookups is that the performance is better when cache misses occur. > > src/java.base/share/classes/jdk/internal/util/HexDigits.java line 204: > >> 202: */ >> 203: public static long hex8(long i) { >> 204: long x = Long.expand(i, 0x0F0F_0F0F_0F0F_0F0FL); > > x86 should use pepd - but aarch64? Seems there is no good way to do so on aarch; raw shifts and going through VPU both seem to be slower. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/22942#discussion_r1906141022