This looks good, and we have done a significant number of test runs to verify its integrity.
I say ship it. +1 We know that there are some issues with sun.misc.ValueConversion.castReference and similar internal methods not being inlined, but as far as I can understand this is a separate issue that will be addressed. By rewriting a guard for Nashorn to not use castReference in the fast case, I get record indy performance with your catch combinator. /M (jdk9 reviewer) On 19 Feb 2014, at 22:46, Vladimir Ivanov <vladimir.x.iva...@oracle.com> wrote: > http://cr.openjdk.java.net/~vlivanov/8027827/final/webrev.00 > https://jbs.oracle.com/bugs/browse/JDK-8027827 > 354 lines changed: 193 ins; 91 del; 70 mod > > OVERVIEW > > MethodHandles.catchException combinator implementation is based on generic > invokers (MethodHandleImpl$GuardWithCatch.invoke_*). It is significantly > slower than a Java equivalent (try-catch). > > Future Nashorn performance improvements require catchException combinator > speed to be on par with try-catch in Java. > > So, it should be represented in a more efficient form. > > I chose the following lambda form representation: > > t_{i}:L=ValueConversions.array(a1:L,...,a_{k}:L); > t_{i+1}:L=MethodHandleImpl.guardWithCatch(t_{p1}, t_{p2}, t_{p3}, t_{i}:L); > t_{i+2}:I=ValueConversions.unbox(t7:L); > OR :L=ValueConversions.identity(t_{n+1}) > OR :V=ValueConversions.ignore(t_{n+1}) > > where: > a1, ..., a_{k} - arguments > t_{p1}, t_{p2}, t_{p3} - target method handle, exception class, catcher > method handle respectively; passed as bounded parameters; > > During lambda form compilation it is converted into bytecode equivalent of > the following Java code: > try { > return target.invokeBasic(...); > } catch(Throwable e) { > if (!exClass.isInstance(e)) throw e; > return catcher.invokeBasic(e, ...); > } > > There's a set of microbenchmarks (attached to the bug) I wrote to verify > performance characteristics of new implementation. > > FURTHER WORK > > What is missing is lambda form caching. The plan is to have a single lambda > form per basic type, but it needs more work - current representation is > suitable for sharing on bytecode level, but lambda form interpretation > doesn't work well (arguments boxing + result unboxing are problematic). > > TESTING > > Tests: microbenchmarks, jdk/java/lang/invoke/, nashorn with optimistic types > (unit tests, octane). > > Tested in 2 modes: > * COMPILE_THRESHOLD=30 > * COMPILE_THRESHOLD=0 -Xverify:all > > OTHER > > 1) Update of cached name and member in LF compilation loop (see > InvokerBytecodeGenerator.generateCustomizedCodeBytes) fixes a bug during > compilation of selectAlternative when running with COMPILE_THRESHOLD=0. > > 2) As part of this change, I fix existing bug [1], so I add regression test > for it. > > Thanks! > > Best regards, > Vladimir Ivanov > > [1] https://bugs.openjdk.java.net/browse/JDK-8034120 _______________________________________________ mlvm-dev mailing list mlvm-dev@openjdk.java.net http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev
