[8u] Request for approval: Backport of 8147548: need comprehensive fix for unconstrained ConvI2L with narrowed type

[Vladimir Kozlov]

RFR for 8u should use original 6675699 bug id and also use it in 8u the 
changeset comment:

https://bugs.openjdk.java.net/browse/JDK-6675699

parse2.cpp  I noticed that JDK9 change remove -1 from "num_cases-1". Was 
it intentional?

graphKit.cpp fast_size_limit is used in jdk9 but not in 8u. Why?

Thanks,
Vladimir

On 1/25/16 1:59 AM, Tobias Hartmann wrote:
> Hi,
>
> please approve and review the following backport to 8u.
>
> 8147548: need comprehensive fix for unconstrained ConvI2L with narrowed type
> https://bugs.openjdk.java.net/browse/JDK-8147548
> http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2016-January/020810.html
> http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/bfb7a8a004de
>
> The fix was pushed to hs-comp on January, 18 and nightly testing showed no problems. Unfortunately, the changes do not apply cleanly to 8u-dev because several enhancements that affect related code were not backported to 8. Here is a new webrev:
> http://cr.openjdk.java.net/~thartmann/6675699_8u/webrev.00/
>
> I did additional performance and correctness testing to verify that the backport works fine and does not introduce a regression.
>
> Thanks,
> Tobias
>