This isn't a bad rule of thumb, but I'd add a caveat: * If you know one concrete shape will always fit the execution, emit the bytecode IFF it's of a reasonable size
Because method handles can blur the lines between methods and dodge some JVM inlining/optimization thresholds, they're often useful for encapsulating nontrivial logic that would bloat up a method body. For example, if you have a lot of pre/post setup for a given call or you have a more complicated expression you want to run as a unit repeatedly, you might be better off shoving that into handles and letting the JVM decide what to inline. Emitting the bytecode in-place is basically like hand inlining...to be used with caution. - Charlie On Mon, May 28, 2012 at 12:45 PM, Attila Szegedi <szege...@gmail.com> wrote: > My rule of thumb is: if you know that one concrete code shape will > always fit the execution, I'd just emit the bytecode. Invokedynamic is > great for cases where the executed code needs to change from time to > time. You can also combine it - the invocation of actual property > getters "getA()", "getB()" etc. are invokeDynamic linked, and the > branching is in bytecode; i.e. if you know that the sequence at that > point in the code will always be "a.b.c.d". > > Attila. > > On Sun, May 27, 2012 at 11:12 AM, Dain Sundstrom <d...@iq80.com> wrote: >> Hi all, >> >> I have a general strategy question about using invoke dynamic. Say I have a >> dynamic language that has null safe property chaining where "a.b.c.d" >> results in null if a null is encountered anywhere in the chain. I could >> implement this two ways, 1) generate byte code that checks for nulls or 2) >> use a guarded method handle at each step that takes care of the nulls. >> Either option is ok with me, but I'd rather not write both versions to and >> then try to figure out which one will make the JVM angry. >> >> As a broader question, there are lots of places where I can make this type >> of decision (e.g., pass by value parameters, copy on assignment value >> classes), is there a rule of thumb for going with traditional byte code over >> branching method handles? >> >> Thanks, >> >> -dain >> _______________________________________________ >> mlvm-dev mailing list >> mlvm-dev@openjdk.java.net >> http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev > _______________________________________________ > mlvm-dev mailing list > mlvm-dev@openjdk.java.net > http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev _______________________________________________ mlvm-dev mailing list mlvm-dev@openjdk.java.net http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev
