RFR: 8250745: Fix a potential bug on AVX512 machines with assert(eval_map.contains(n)) failed: absent

[Vladimir Kozlov]

On 7/29/20 2:20 AM, Vladimir Ivanov wrote:
>> Webrev: http://cr.openjdk.java.net/~jiefu/8250745/webrev.00/
> 
> Looks good.

+1

> 
> FTR the bug was introduced by JDK-8241040, but I don't see a way it can be hit by auto-vectorizer: before it kicks in, 
> scalar code is strongly normalized and constants are pushed to the right. It leads to the shape where (Replicate -1) is 
> always the second input of bitwise NOT shape (XorV v (Replicate -1)). Since there are no GVN transformations happening 
> for vector nodes, both left-hand and right-hand variants become possible with Vector API.

So it is difficult to write a test?

Thanks,
Vladimir K

> 
> Best regards,
> Vladimir Ivanov