On Thu, 12 Oct 2023 09:19:35 GMT, Shaojin Wen <d...@openjdk.org> wrote:
>> Let's not forget that `Character.digit()` has a pretty decent fast path for
>> Latin1, including a 256 bytes lookup-table.
>
> CharacterDataLatin1.digit is for multi-radix, and the performance when radix
> = 10 is not good enough.
If we reuse CharacterDataLatin1#DIGITS, the performance will be slower, the
performance numbers are as follows
class CharacterDataLatin1 {
static int digit(int ch) {
int value = DIGITS[ch & 0xFF];
return (value >= 0 && value < 10) ? value : -1;
}
}
Benchmark (size) Mode Cnt Score Error Units (baseline)
Integers.parseInt 500 avgt 15 2.614 ? 0.003 us/op
Benchmark (size) Mode Cnt Score Error Units (use
CharacterDataLatin1#digit)
Integers.parseInt 500 avgt 15 2.399 ? 0.008 us/op
Benchmark (size) Mode Cnt Score Error Units (c3e878a)
Integers.parseInt 500 avgt 15 2.251 ? 0.010 us/op
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/16112#discussion_r1356582378
