On Tuesday, 22 July 2014 at 08:10:31 UTC, Russel Winder via
Digitalmars-d wrote:
On Tue, 2014-07-22 at 06:35 +0000, Paulo Pinto via
Digitalmars-d wrote:
[…]
Yes it can, if developers bother to do PGO + AOT instead and
learn the compiler flags.
I used to have a stronger opinion on JIT, but given how many
JITs perform and do not actually use the hardware as they, in
theory could, JIT tend to only be an advantage for dynamic
languages not strong typed ones.
With JIT, writing the code in a way that makes the JIT
compiler happy is a lost battle, as it depends on the exact
same JIT implementation being available on the deployment
system.
I think you have to make good on this claim since the JVM JIT is
intended for Java which is supposedly a static, strongly typed
language.
The JVM JIT was originally targeted to SELF, not Java.
Moreover, evidence from Groovy is the JVM JIT provides only
patchy
benefit. The biggest benefit all round is invokedynamic for
both static
and dynamic languages. Java 8 would be nothing without
invokedynamic.
Functional programming languages have AOT compilers and they
perform quite well, almost to C level in many use case cases.
As for Groovy, I always felt the implementation was always
lacking in performance.
I avoid touching Gradle.
But maybe we should take this off this list as it is way off
topic.
Clearly we can use JMH for benchmarking. I have a couple of
codes I
could use to try things out.
So:
1. How to compile and execute to get full AOT *and* switch off
the JIT.
2. How to compile and execute to get no AOT and have JIT on
full.
then we can begin to compare.
I was discussing JIT vs AOT in abstract.
To be able to perform such a tests you need:
- A programming language X
- The state of the art JIT compiler implementation for the given
language
- The state of the art AOT compiler implementation for the given
language
I know a few commercial AOT compilers for Java, not sure which
one would be the best one to choose.
But the proof is Microsoft adding .NET Native to their toolchain,
Google replacing Dalvik with AOT and Oracle has added AOT
compilation (Substract) to Graal, the candidate to Hotspot
replacement.
So apparently they all agree AOT still wins in many scenarios.
--
Paulo
