[8u-dev] Request for approval: Backport of 8011858

[Vladimir Kozlov]

On 9/14/15 7:31 AM, Zoltán Majó wrote:
> Hi,
>
>
> I would like to request the backport of the fix for JDK-8011858 to 8u-dev. The fix can help reducing the memory usage of
> the C2 compiler and is therefore needed to fix JDK-8129847.
>
> Original (9) bug: https://bugs.openjdk.java.net/browse/JDK-8011858
> Original changeset: http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/af60f1cb36f2
>
> Unfortunately, the fix does not apply cleanly, as two affected files are different in 9 and in 8u-dev. Here are the
> changes that I did not (could not) apply to the 8u-dev tree:

Can you scan jdk8u C2 code for other cases where C->unique() is used for stack. May be some were removed in jdk9. But we 
still need to fix them.

> - http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/af60f1cb36f2#l6.8
> - http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/af60f1cb36f2#l9.8

node.cpp has next code in dump_nodes() which you should fix (I look on jdk8u/jdk8u/hotspot code):

GrowableArray <Node *> nstack(C->unique());

Thanks,
Vladimir

>
> Webrev: http://cr.openjdk.java.net/~zmajo/8011858_8u/webrev.00/
>
> Testing:
> - the fix was pushed into 9 on Aug 11 and did not cause any nightly failures;
> - all JPRT tests pass;
> - all JTREG tests pass that pass with the unmodified VM.
>
> Thank you and best regards,
>
>
> Zoltan
>