On Tue, 10 Aug 2021 13:16:42 GMT, Сергей Цыпанов <github.com+10835776+stsypa...@openjdk.org> wrote:
> The code in `Integer.decode()` and `Long.decode()` might allocate two > instances of Integer/Long for the negative values less than -127: > > Integer result; > > result = Integer.valueOf(nm.substring(index), radix); > result = negative ? Integer.valueOf(-result.intValue()) : result; > > To avoid this we can declare 'result' as `int` and use `Integer.parseInt()` > method. Same applicable for `Long` and some other classes. Looks fine to me. Could you consider adding microbenchmarks for Integer/Long.decode? src/java.base/share/classes/java/lang/Integer.java line 1450: > 1448: > 1449: try { > 1450: result = parseInt(nm.substring(index), radix); Possibly a follow-up, but I think using `parseInt/-Long(nm, index, nm.length(), radix)` could give an additional speed-up in these cases (by avoiding a substring allocation). ------------- Marked as reviewed by redestad (Reviewer). PR: https://git.openjdk.java.net/jdk/pull/5068