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Posted to dev@harmony.apache.org by George Timoshenko <ge...@gmail.com> on 2008/04/16 12:40:45 UTC

[drlvm][jit][opt] new feature: switchable autocompress mode

Colleagues,

I created a new JIRA issue with an improvement proposal for Jitrino.OPT.
https://issues.apache.org/jira/browse/HARMONY-5743

In compressed mode OPT always uncompress a ref just after it is loaded 
from memory (from field).
So each reference is uncompressed in the managed code.
It is a convention in HLO. There are not dedicated instructions for 
compression/uncompression.
IRBuilder generates LdField and its dst operand has type - UncompressedRef.

It probably has sense not to uncompress ref if it is loaded just for 
NULL comparison or storing to another field.
To do this we need to generate Compress/Uncompress instructions 
explicitly during byte code translation.

I almost completed this work.
Unfortunately it may happen I will have no ability to complete this work.
I will be happy to see somebody completed the task.


Thank you,
George.


Re: [drlvm][jit][opt] new feature: switchable autocompress mode

Posted by George Timoshenko <ge...@gmail.com>.
Mikhail Fursov wrote:
> Is it possible to integrate it in disabled mode with a command line option
> turned off?

Sure.


Re: [drlvm][jit][opt] new feature: switchable autocompress mode

Posted by Mikhail Fursov <mi...@gmail.com>.
Is it possible to integrate it in disabled mode with a command line option
turned off?
I see that there are a lot of useful changes in the patch and it gets older
every day

On Thu, Apr 17, 2008 at 12:47 PM, George Timoshenko <
george.timoshenko@gmail.com> wrote:

> Mikhail,
>
> It is not complete.
>
> It must be tested carefully.
> One more problem: the patch is outdated.
> It needs to be refreshed.
>
>
>


-- 
Mikhail Fursov

Re: [drlvm][jit][opt] new feature: switchable autocompress mode

Posted by George Timoshenko <ge...@gmail.com>.
Mikhail,

It is not complete.

It must be tested carefully.
One more problem: the patch is outdated.
It needs to be refreshed.



Re: [drlvm][jit][opt] new feature: switchable autocompress mode

Posted by Mikhail Fursov <mi...@gmail.com>.
Thanks, George,
I'm going to review and commit this feature.

On Wed, Apr 16, 2008 at 5:40 PM, George Timoshenko <
george.timoshenko@gmail.com> wrote:

> Colleagues,
>
> I created a new JIRA issue with an improvement proposal for Jitrino.OPT.
> https://issues.apache.org/jira/browse/HARMONY-5743
>
> In compressed mode OPT always uncompress a ref just after it is loaded
> from memory (from field).
> So each reference is uncompressed in the managed code.
> It is a convention in HLO. There are not dedicated instructions for
> compression/uncompression.
> IRBuilder generates LdField and its dst operand has type -
> UncompressedRef.
>
> It probably has sense not to uncompress ref if it is loaded just for NULL
> comparison or storing to another field.
> To do this we need to generate Compress/Uncompress instructions explicitly
> during byte code translation.
>
> I almost completed this work.
> Unfortunately it may happen I will have no ability to complete this work.
> I will be happy to see somebody completed the task.
>
>
> Thank you,
> George.
>
>


-- 
Mikhail Fursov