RFR: 8318509: x86 count_positives intrinsic broken for -XX:AVX3Threshold=0

Mon Oct 23 19:22:54 UTC 2023

On Mon, 23 Oct 2023 08:23:29 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

> But I would suggest that you improve the test as well, or at least add some random example as well (random values in array, random length etc). Currently it is all deterministic, and I'm not sure that the pattern really covers all cases enough.

Ok. I modernized and rewrote the tests to test random array segment lengths and randomly selected negatives. Also added some cases where negatives are only found in the tail.

Also updated TestHasNegatives to run with AVX3Threshold=0 when applicable, and verified both tests still either fail or crash without the patch in this mode.

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PR Comment: https://git.openjdk.org/jdk/pull/16267#issuecomment-1775872898