[aarch64-port-dev ] RFR(S): 8243597: AArch64: Add support for integer vector abs

[Andrew Haley]

On 05/06/2020 06:52, Yang Zhang wrote:
> The test cases in TestScalar.java  are used to benchmark AbsI.

When I ask for a java program that reproduces your result, it's not
unreasonable for me to expect you to send one. You still haven't, and
I don't understand why your test case wasn't provided.

Can you please add a benchmark to your JMH benchmarks that actually
shows the result you claimed? Thank you?

>   @Benchmark
>   public void testAbsI() {
>      for (int n = 0; n < LOOP_CNT; n++) {
>          for (int i = 0; i < ia.length; i += 4) {  ----------> That stride is *4* will make auto-vectorization fail. Only AbsI node is generated.
>              ic[i] = Math.abs(ia[i] + ib[i]);
>          }
>      }
>   } 

> Or you can also use jmh vector test cases which are used to benchmark vector abs.
> http://cr.openjdk.java.net/~yzhang/8243597/TestVect.java

That is what I have been doing. They do not show the result above.

-- 
Andrew Haley  (he/him)
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
https://keybase.io/andrewhaley
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