On Wed, 1 Mar 2023 14:28:55 GMT, Eirik Bjorsnos <d...@openjdk.org> wrote:
>> This PR suggests we add a vectorized equalsIgnoreCase benchmark to the set
>> of benchmarks in `org.openjdk.bench.jdk.incubator.vector`. This benchmark
>> serves as an example of how vectorization can be useful also in the area of
>> text processing. It takes advantage of the fact that ASCII and Latin-1 were
>> designed to optimize case-twiddling operations.
>>
>> The code came about during the work on #12632, where vectorization was
>> deemed out of scope.
>>
>> Benchmark results:
>>
>>
>> Benchmark (size) Mode Cnt Score Error
>> Units
>> EqualsIgnoreCaseBenchmark.scalar 16 avgt 15 21.575 ± 0.365
>> ns/op
>> EqualsIgnoreCaseBenchmark.scalar 32 avgt 15 43.199 ± 2.786
>> ns/op
>> EqualsIgnoreCaseBenchmark.scalar 64 avgt 15 71.389 ± 0.891
>> ns/op
>> EqualsIgnoreCaseBenchmark.scalar 128 avgt 15 146.827 ± 1.115
>> ns/op
>> EqualsIgnoreCaseBenchmark.scalar 1024 avgt 15 1062.759 ± 9.331
>> ns/op
>> EqualsIgnoreCaseBenchmark.vectorized 16 avgt 15 21.483 ± 0.121
>> ns/op
>> EqualsIgnoreCaseBenchmark.vectorized 32 avgt 15 10.538 ± 0.125
>> ns/op
>> EqualsIgnoreCaseBenchmark.vectorized 64 avgt 15 13.182 ± 0.177
>> ns/op
>> EqualsIgnoreCaseBenchmark.vectorized 128 avgt 15 19.192 ± 0.421
>> ns/op
>> EqualsIgnoreCaseBenchmark.vectorized 1024 avgt 15 92.521 ± 3.494
>> ns/op
>
> Eirik Bjorsnos has updated the pull request incrementally with one additional
> commit since the last revision:
>
> Use GT, LT, EQ operations since they seem to outperform GE, LE, NE.
Benchmark looks good.
I think you need to look at the generated code and perf data to get more
insight into the differences you are observing.
Sometimes array alignment can add variance to the results (which may not be the
case here), and to rule that out i sometimes run vector tests with the HotSpot
option `-XX:ObjectAlignmentInBytes` e.g. `-XX:ObjectAlignmentInBytes=32`.
test/micro/org/openjdk/bench/jdk/incubator/vector/EqualsIgnoreCaseBenchmark.java
line 111:
> 109: .or(letter.and(upperA.eq(upperB)));
> 110:
> 111: if(equalsIgnoreCase.allTrue()) {
Suggestion:
if (equalsIgnoreCase.allTrue()) {
-------------
PR: https://git.openjdk.org/jdk/pull/12790
