[9] RFR (XS): 8072422: Change a number of flags controlling loop optimizations to 'develop'

Vladimir Kozlov vladimir.kozlov at oracle.com
Wed Mar 23 22:58:27 UTC 2016

These flags were added when I fixed long standing C2 problem with counted loops: 5091921.
They were added to have ability to revert back to original code if new code cause a problem.
Looks like the old code which executed with these flags switched off become rotten.

Zoltan, did you find what cause the crash? Looks like product VM was used in the bug report. What result gives fastdebug VM?
Converting flags to develop will not prevent problems happening with fastdebug VM where these flags could be switched off even when they are develop.

If the problem with original code (flags are off) is something fundamental we may simple remove old code and remove these flags and have only new code. 5 years already passed since 5091921 was fixed.


On 3/23/16 6:26 AM, Zoltán Majó wrote:
> Hi,
> please review the patch for 8072422.
> https://bugs.openjdk.java.net/browse/JDK-8072422
> Problem: Some flags controlling loop optimizations are currently 'diagnostic'. Even though these flags are useful mostly for compiler-related development, their value can be changed not only in
> fastdebug, but also also in release builds,
> Solution: Change the flags to 'develop'.
> Webrev:
> http://cr.openjdk.java.net/~zmajo/8072422/webrev.00/
> Testing:
> - locally built/started VM;
> - locally executed runtime/CommandLine/OptionsValidation/TestOptionsWithRanges.java.
> Thank you and best regards,
> Zoltan

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