Hi Sergey, hum, it doesn't work :) int.class is compiled by javac as Integer.TYPE, the opcode ldc only works with an object/interface class, not with a primitive type [1].
regards, Rémi [1] https://docs.oracle.com/javase/specs/jvms/se13/html/jvms-6.html#jvms-6.5.ldc ----- Mail original ----- > De: "Сергей Цыпанов" <sergei.tsypa...@yandex.ru> > À: "core-libs-dev" <core-libs-dev@openjdk.java.net> > Envoyé: Mardi 26 Novembre 2019 20:29:06 > Objet: [PATCH] Simplification proposal regarding TYPE-field initialization in > primitive wrappers > Hello, > > while using java.lang.Integer.TYPE I've found out that currently wrapper > classes > for primitives initialize their own TYPE-fields by calling native method > java.lang.Class.getPrimitiveClass(). > > This can be simplified by changing existing declaration (here for > java.lang.Integer) > > @SuppressWarnings("unchecked") > public static final Class<Integer> TYPE = (Class<Integer>) > Class.getPrimitiveClass("int"); > > to > > public static final Class<Integer> TYPE = int.class; > > This is likely to improve start-up time as Class.getPrimitiveClass() is > called 9 > times (8 primitive type wrappers + java.lang.Void), after the change this > method is not called at all and thus can be removed along with its backing C++ > code on VM-side. The fields are initialized purely on Java side. > > I've verified correctness of the substitution with this test run on JDK 11 > > @Test > void name() { > assert void.class == Void.TYPE; > assert boolean.class == Boolean.TYPE; > assert byte.class == Byte.TYPE; > assert char.class == Character.TYPE; > assert short.class == Short.TYPE; > assert int.class == Integer.TYPE; > assert long.class == Long.TYPE; > assert float.class == Float.TYPE; > assert double.class == Double.TYPE; > } > > The patch is attached. > > Regards, > Sergey Tsypanov
