On Wed, 4 Jan 2023 15:20:10 GMT, Pavel Rappo <pra...@openjdk.org> wrote:
>> Currently Set.copyOf allocates both a HashSet and a new empty array when the >> input collection is empty. >> >> This patch avoids allocating anything for the case where the parameter >> collection's isEmpty returns true. > > Curious: how bad was that "needless allocation" that it was required to be > optimized away? @pavelrappo Fair question! I guess it depends on what dominates the benchmark: given that the copyOf methods goes to some length to try to avoid allocating new instances of the immutable sets the proposed patch seemed like rather low-hanging fruit. I found this as I was running some (to be fair, rather specific) benches which drew my attention to it. ------------- PR: https://git.openjdk.org/jdk/pull/11847
