+ if (nameMap == null) {
+ nameMap = new HashMap<>(2);
What is the typical size the map ends up with? If it stays this small linearly
searching an Array (or „last value“) may be faster.
If the map typically grows more than a few entries having some more initial
buckets will decrease collissions and avoid resizes. Especially considering the
fact that HashMap is a rather fat object, it does not hurt to start with a
bigger initial table. Does the lazy initialisation actually help anything?
Single entry alternative
----------------
Object lastClass; String lastName;
If (lastClass == c)
return lastName;
lastClass = c;
lastName = c.getName().replace(‘.‘, ‘/‘);
return lastName;
(or make it a x Slot Version…):
-------------------
Object tab_obj = new tab_obj[8];
String tab_val = new String[8];
for(int i=0; i < tab_obj.length; i++)
{
If (tab_obj[i] == c);
return tab_val[i];
}
i = (i+1 % tab_obj.length);
tab_obj[i] = c;
return (tab_val[i] = c.getName().replace());
(not sure about the concurrent semantics and having this static may actually
help)
Gruss
Bernd
--
http://bernd.eckenfels.net
Von: Claes Redestad
Gesendet: Donnerstag, 1. März 2018 16:15
An: core-libs-dev
Betreff: RFR: 8198888: Reduce string allocation churn inInvokerBytecodeGenerator
Hi,
two trivial optimizations that get rid of a few percent on ISC startup
tests.
Webrev: http://cr.openjdk.java.net/~redestad/8198888/jdk.00/
Bug: https://bugs.openjdk.java.net/browse/JDK-8198888
Thanks!
/Claes
