RFR: 8279282: [vectorapi] Matcher::supports_vector_comparison_unsigned is not needed on x86

Wed Jan 5 21:22:15 UTC 2022

On Wed, 5 Jan 2022 10:30:46 GMT, Quan Anh Mai <duke at openjdk.java.net> wrote:

> Hi,
> 
> Currently, unsigned comparison on AVX is implemented by zero extending elements and comparing the results. This leads to unnecessary complexity. This patch changes the implementation to use the identity existing in `Integer/Long.compareUnsigned`, that is `compareUnsigned(x, y) == compare(x ^ min_value, y ^ min_value)`.
> 
> Thank you very much.

Do we have tests which verify correctness of unsigned compare?

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PR: https://git.openjdk.java.net/jdk/pull/6966