[9] RFR (S): 8150186: Folding mismatched accesses with @Stable is incorrect

[Vladimir Ivanov]

Vladimir, John, Aleksey, thanks for the reviews.

Best regards,
Vladimir Ivanov

On 2/25/16 7:56 AM, John Rose wrote:
> Reviewed.
>
> – John
>
>> On Feb 24, 2016, at 8:06 AM, Vladimir Ivanov <vladimir.x.ivanov at oracle.com> wrote:
>>
>> http://cr.openjdk.java.net/~vlivanov/8150186/webrev.00/
>> https://bugs.openjdk.java.net/browse/JDK-8150186
>>
>> Constant folding from stable arrays doesn't check for mismatched accesses.
>>
>> The fix is to disable the optimization for mismatched accesses.
>>
>> Also, added missing range checks in ciArray::element_value_by_offset.
>>
>> Testing: failing tests, JPRT
>>
>> Best regards,
>> Vladimir Ivanov
>>
>> PS: I considered converting is_mismatched_access check in fold_stable_ary_elem into an assert, but I spotted some quirks in mismatched access detection (filed JDK-8150543 [1]). So, I'd prefer to keep the check and refine the code as part of JDK-8150543 when more test coverage is available.
>>
>> [1] https://bugs.openjdk.java.net/browse/JDK-8150543