On 13.09.2011 00:59, John Rose wrote:
This exposes the question of liveness: JVMs routinely nullify
non-live variables, but what if the only remaining use is the
getLocalArray intrinsic? Shouldn't it count as a weak reference? Or
will we allow it to reanimate all local values? That
From Thomas
(e.g., they could
use the Java expression stack as their own expression stack
implementation).
I believe that this is both used and necessary to create reasonable
performance implementation
of Smalltalk on the jvm. I do this in Rtalk today mapping the Smalltalk
On Sep 14, 2011, at 10:10 AM, Thomas Wuerthinger wrote:
On 13.09.2011 00:59, John Rose wrote:
This exposes the question of liveness: JVMs routinely nullify
non-live variables, but what if the only remaining use is the
getLocalArray intrinsic? Shouldn't it count as a weak reference? Or
On 9/14/11 10:20 PM, Tom Rodriguez wrote:
On Sep 14, 2011, at 10:10 AM, Thomas Wuerthinger wrote:
On 13.09.2011 00:59, John Rose wrote:
This exposes the question of liveness: JVMs routinely nullify
non-live variables, but what if the only remaining use is the
getLocalArray intrinsic?
On Sep 14, 2011, at 3:05 PM, Thomas Wuerthinger wrote:
But one could maybe disable the local variable liveness maps
for the methods that use this functionality (i.e., the extended
exception stack trace or the getLocalArray)?
Yes, of course. But this will increase spilling throughout those
On 09.09.2011 03:00, John Rose wrote:
On Sep 8, 2011, at 5:35 PM, Thomas Wuerthinger wrote:
The operand stack and locals manipulation in the generated bytecodes
must exactly match the manipulations done by the scripting
interpreter, but I think that it is possible to align those (although
On Sep 12, 2011, at 10:23 AM, Thomas Wuerthinger wrote:
If this special exception class is declared as a checked exception, a method
would itself chose if its stack is exposed or not based on its throws
clause. I think in that case the possible exploitations are less than
reflection
I've taken the time to write a small prototype (by hand :( )
see http://www-igm.univ-mlv.fr/~forax/tmp/jsr292-deopt.zip
using Fibonacci as John suggest.
The idea is to transfer the control from fibo written using
ints to fibo written using Object (BigInteger at runtime).
If an operation
On Sep 8, 2011, at 4:57 AM, Thomas Wuerthinger wrote:
Why not the following code pattern? Does it generate too many bytecodes?
That's a reasonable alternative.
It generates data movement bytecodes O(L * M), where L is the average number of
live values at deopt points and M is the number of
On 09/08/2011 01:12 AM, John Rose wrote:
On Sep 7, 2011, at 3:28 PM, Rémi Forax wrote:
On 09/07/2011 10:38 PM, John Rose wrote:
Object l0, l1, l2, ...;
l0 = l1 = l2 = ... null; // these are required only for definite
assignment in the catch body
try {
...do fast path...
On 08.09.2011 21:47, John Rose wrote:
On Sep 8, 2011, at 4:57 AM, Thomas Wuerthinger wrote:
Why not the following code pattern? Does it generate too many bytecodes?
That's a reasonable alternative.
It generates data movement bytecodes O(L * M), where L is the average
number of live values
On Sep 8, 2011, at 4:06 PM, Thomas Wuerthinger wrote:
Here an example for a scripting method that performs a+b and is guessed to
not overflow.
Your example is simplified by the fact that, in the handler, there is only one
possible deopt point. What if there are two?
E.g., what if your code
On Sep 8, 2011, at 3:06 PM, Rémi Forax wrote:
but you can get live value unless you allow to insert live values to the
constant pool
when linking the class (another old dream).
Can we make a solution from ClassValue? -- John
___
mlvm-dev mailing
If we have coroutine, yes!
Remi
John Rose john.r.r...@oracle.com wrote:
On Sep 8, 2011, at 3:06 PM, Rémi Forax wrote:
but you can get live value unless you allow to insert live values to the
constant pool
when linking the class (another old dream).
Can we make a solution from ClassValue?
On 09.09.2011 01:21, John Rose wrote:
On Sep 8, 2011, at 4:06 PM, Thomas Wuerthinger wrote:
Here an example for a scripting method that performs a+b and is
guessed to not overflow.
Your example is simplified by the fact that, in the handler, there is
only one possible deopt point. What if
On Sep 8, 2011, at 5:35 PM, Thomas Wuerthinger wrote:
The operand stack and locals manipulation in the generated bytecodes must
exactly match the manipulations done by the scripting interpreter, but I
think that it is possible to align those (although there might be some
complexity due to
On 09/06/2011 08:07 PM, Charles Oliver Nutter wrote:
I also thought of an existing API that would benefit from this, and
perhaps there's a path to getting something in JDK 7 (unofficially)
and JDK 8 (officially): BigInteger. Ideally BigInteger should only use
a primitive long (or int?) up to
On Sep 7, 2011, at 12:00 AM, Per Bothner wrote:
I assume this is one reason why Kawa's IntNum is (mostly) faster than
BigInteger.
Yes, that's probably true.
Here's a dirty secret: As you can see from the OpenJDK sources, BigDecimal,
but not BigInteger, has this optimization (see private
On 09/07/2011 09:08 AM, John Rose wrote:
On Sep 7, 2011, at 12:00 AM, Per Bothner wrote:
I assume this is one reason why Kawa's IntNum is (mostly) faster than
BigInteger.
Yes, that's probably true.
Here's a dirty secret: As you can see from the OpenJDK sources,
BigDecimal, but not
...@openjdk.java.net
[mailto:mlvm-dev-boun...@openjdk.java.net] On Behalf Of John Rose
Sent: 06 September 2011 21:05
To: Da Vinci Machine Project
Subject: Re: Hotspot loves PHP.reboot
On Sep 6, 2011, at 8:51 AM, Charles Oliver Nutter wrote:
Did we ever figure out if it's possible to trick
On Sep 7, 2011, at 11:15 AM, Rémi Forax wrote:
On 09/07/2011 09:08 AM, John Rose wrote:
On Sep 7, 2011, at 12:00 AM, Per Bothner wrote:
I assume this is one reason why Kawa's IntNum is (mostly) faster than
BigInteger.
Yes, that's probably true.
Here's a dirty secret: As you can
*Sent:* 06 September 2011 21:05
*To:* Da Vinci Machine Project
*Subject:* Re: Hotspot loves PHP.reboot
On Sep 6, 2011, at 8:51 AM, Charles Oliver Nutter wrote:
Did we ever figure out if it's possible to trick Hotspot into doing a
JO instead of the raw bit-level operations? John/Christian/Tom
On 09/07/2011 01:22 PM, Christian Thalinger wrote:
On Sep 7, 2011, at 11:15 AM, Rémi Forax wrote:
On 09/07/2011 09:08 AM, John Rose wrote:
On Sep 7, 2011, at 12:00 AM, Per Bothner wrote:
I assume this is one reason why Kawa's IntNum is (mostly) faster than
BigInteger.
Yes, that's
On 09/07/2011 05:07 AM, Charles Oliver Nutter wrote:
On Tue, Sep 6, 2011 at 6:10 PM, John Rosejohn.r.r...@oracle.com wrote:
Yes. Your request for JO makes me think some users would be happy with a
boolean test, a la addWouldOverflow.
It's what happens after the test that differs widely
On Sep 7, 2011, at 7:24 AM, Rémi Forax wrote:
so the VM knows that only methods *DetectingOverflow are able to throw that
specific exception.
int addDetectingOverflow(int x, int y) throws IntegerOverflowException
This also have the advantage that the inlining heuristic can be tweaked
to not
On Sep 7, 2011, at 12:33 PM, Thomas Wuerthinger wrote:
This would probably also mean that the exception object created for capturing
the slow-case program state needs to be escape-analyzed and removed in the
optimized code that deoptimizes on overflow?
Yes. And in the case of user-defined
On 09/07/2011 09:32 PM, Per Bothner wrote:
On 09/07/2011 02:15 AM, Rémi Forax wrote:
This remember me that we don't have any benchmarks using dynamic languages
which is, as you explain, not good on the long term.
What about having 10 to 12 benchs, one by language, provided by each
language
On 09/07/2011 02:25 PM, Charles Oliver Nutter wrote:
On Wed, Sep 7, 2011 at 2:00 AM, Per Bothnerp...@bothner.com wrote:
Kawa's gnu.math.IntNum already does this. It has only two fields:
Yeah, I think I remember you mentioning this in one of the
arbitrary-precision math threads on JVM-L. I
On 09/07/2011 03:02 PM, Rémi Forax wrote:
On 09/07/2011 09:32 PM, Per Bothner wrote:
On 09/07/2011 02:15 AM, Rémi Forax wrote:
What about having 10 to 12 benchs, one by language, provided by each
language runtime developer
as a good bench for their runtime ?
Well, there are the Computer
On Sep 7, 2011, at 3:28 PM, Rémi Forax wrote:
On 09/07/2011 10:38 PM, John Rose wrote:
Object l0, l1, l2, ...;
l0 = l1 = l2 = ... null; // these are required only for definite
assignment in the catch body
try {
...do fast path...
if (...constraint violated...) throw new
It would be really nice if you could have a class that was something like
Double with overflow check initially and then when you detect an overflow
substitute in something like BigDecimal instead, i.e. hot swapping of the
object's class. This saves having to have a class with two fields and
Awesome numbers, especially promising for impls like JRuby that will
never have type annotations and for which type inference will be very
limited. Getting within 3x Java while still fully boxed is amazing.
Perhaps the next big thing for InDy will be getting EA working across
invokedynamic
On Tue, Sep 6, 2011 at 10:39 AM, Rémi Forax fo...@univ-mlv.fr wrote:
Yes, but don't forget that PHP.reboot has no overflow check.
Did we ever figure out if it's possible to trick Hotspot into doing a
JO instead of the raw bit-level operations? John/Christian/Tom: what
would it take to get HS to
On Sep 6, 2011, at 5:51 PM, Charles Oliver Nutter wrote:
On Tue, Sep 6, 2011 at 10:39 AM, Rémi Forax fo...@univ-mlv.fr wrote:
Yes, but don't forget that PHP.reboot has no overflow check.
Did we ever figure out if it's possible to trick Hotspot into doing a
JO instead of the raw bit-level
On 09/06/2011 07:33 PM, Christian Thalinger wrote:
On Sep 6, 2011, at 5:51 PM, Charles Oliver Nutter wrote:
On Tue, Sep 6, 2011 at 10:39 AM, Rémi Foraxfo...@univ-mlv.fr wrote:
Yes, but don't forget that PHP.reboot has no overflow check.
Did we ever figure out if it's possible to trick
On 09/06/2011 05:51 PM, Charles Oliver Nutter wrote:
On Tue, Sep 6, 2011 at 10:39 AM, Rémi Foraxfo...@univ-mlv.fr wrote:
Yes, but don't forget that PHP.reboot has no overflow check.
Did we ever figure out if it's possible to trick Hotspot into doing a
JO instead of the raw bit-level
On Tue, Sep 6, 2011 at 12:33 PM, Christian Thalinger
christian.thalin...@oracle.com wrote:
We already talked a bit about that some while ago. I think matching that
double-xor-trick (or whatever it's called) is too risky. A JDK method that
does the check (and the math?) would be nice so we
On Tue, Sep 6, 2011 at 12:36 PM, Rémi Forax fo...@univ-mlv.fr wrote:
If you have specialize for -2/+2, you should reuse exactly the same code
for +n/-n.
see
https://code.google.com/p/jsr292-cookbook/source/browse/trunk/binary-operation/src/jsr292/cookbook/binop/RT.java#11
You're right. I'll
On Sep 6, 2011, at 8:51 AM, Charles Oliver Nutter wrote:
Did we ever figure out if it's possible to trick Hotspot into doing a
JO instead of the raw bit-level operations? John/Christian/Tom: what
would it take to get HS to know that we're doing an integer
overflow-after-maths check and do the
On Tue, Sep 6, 2011 at 3:04 PM, John Rose john.r.r...@oracle.com wrote:
(1) Write a compelling API for something like Integer.addDetectingOverflow.
(2) Roll it into JDK 8+epsilon.
(3) Do the JIT work.
People have thought on and off about (1) for many years, but with no clear
winner.
On Sep 6, 2011, at 12:58 PM, John Rose wrote:
What's needed here is a way to get 33 bits out of a 32-bit add intrinsic.
There's no fully natural way to do this, and about 4 kludgey ways. Because
there are so many poor ways to shape the API, it's hard to pick the best one
to invest in.
On 09/06/2011 10:19 PM, John Rose wrote:
On Sep 6, 2011, at 12:58 PM, John Rose wrote:
What's needed here is a way to get 33 bits out of a 32-bit add
intrinsic. There's no fully natural way to do this, and about 4
kludgey ways. Because there are so many poor ways to shape the API,
it's
On Tue, Sep 6, 2011 at 3:36 PM, Rémi Forax fo...@univ-mlv.fr wrote:
An exception is perhaps more easier to use,
because if it overflow you may have to deoptimize, for that you need the
stack and local values,
it's easier to jump to a exception handler that will push all these values
and call
On Tue, Sep 6, 2011 at 6:10 PM, John Rose john.r.r...@oracle.com wrote:
Yes. Your request for JO makes me think some users would be happy with a
boolean test, a la addWouldOverflow.
It's what happens after the test that differs widely among applications, so
why not just standardize the test.
On Sep 5, 2011, at 1:11 AM, Rémi Forax wrote:
I've just compiled the hotspot (64bits server) using the hotspot-comp
workspace of hotspot express (hsx)
http://hg.openjdk.java.net/hsx/hotspot-comp/hotspot/
Here are the result when running PHP.reboot on fibonacci
(-server is the server VM
On 09/05/2011 12:22 PM, Christian Thalinger wrote:
On Sep 5, 2011, at 1:11 AM, Rémi Forax wrote:
I've just compiled the hotspot (64bits server) using the hotspot-comp
workspace of hotspot express (hsx)
http://hg.openjdk.java.net/hsx/hotspot-comp/hotspot/
Here are the result when running
I've just compiled the hotspot (64bits server) using the hotspot-comp
workspace of hotspot express (hsx)
http://hg.openjdk.java.net/hsx/hotspot-comp/hotspot/
Here are the result when running PHP.reboot on fibonacci
(-server is the server VM of jdk1.7.0):
Java:
java -server bigfibo4.45
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