On Tue, 28 Feb 2023 22:19:46 GMT, Sandhya Viswanathan
<sviswanat...@openjdk.org> wrote:
>> Eirik Bjorsnos has updated the pull request incrementally with one
>> additional commit since the last revision:
>>
>> Use GE, LE, NE operations instead of the lt,not combinations. Use
>> uppercase in vectorized code to match the scalar version.
>
> test/micro/org/openjdk/bench/jdk/incubator/vector/EqualsIgnoreCaseBenchmark.java
> line 85:
>
>> 83:
>> 84: // ASCII and Latin-1 were designed to optimize
>> case-twiddling operations
>> 85: ByteVector lowerA = va.or((byte) 0x20);
>
> Just curious, here you use lower whereas in scalar code upper is being used.
> Any reasons?
I can't remember the exact reason. Perhaps I thought I could get simpler range
checking of the Latin-1 code points because they are almost at the end of the
Latin-1 range.
I changed the vectorized version to use uppercase for better alignment with the
scalar version.
> test/micro/org/openjdk/bench/jdk/incubator/vector/EqualsIgnoreCaseBenchmark.java
> line 88:
>
>> 86:
>> 87: // Determine which bytes represent ASCII or Latin-1 letters:
>> 88: VectorMask<Byte> asciiLetter = lowerA.lt((byte)
>> '{').and(lowerA.lt((byte) 0x60).not());
>
> We do have GT/GE/NE etc comparison operators supported in Vector API, which
> you can use here and other places in this benchmark. e.g.
> You could do lowerA.compare(GE, (byte)0x60) instead of using lt() followed
> not(). BTW did you mean to use GT here?
>
> You will need to do the following import:
> import static jdk.incubator.vector.VectorOperators.*;
Thanks, that's a lot more readable! This checks that bytes are in the range =>
(byte) 'A', <= (byte) 'A', so I think this "not less than" was a poor man's
compare(GE, (byte) 'A') here.
I've updated the code to use LE, GE, NE where appropriate
-------------
PR: https://git.openjdk.org/jdk/pull/12790
