On Tue, 12 Mar 2024 19:09:27 GMT, Shaojin Wen <d...@openjdk.org> wrote:
>> The current BigDecimal(String) constructor calls String#toCharArray, which
>> has a memory allocation.
>>
>>
>> public BigDecimal(String val) {
>> this(val.toCharArray(), 0, val.length()); // allocate char[]
>> }
>>
>>
>> When the length is greater than 18, create a char[]
>>
>>
>> boolean isCompact = (len <= MAX_COMPACT_DIGITS); // 18
>> if (!isCompact) {
>> // ...
>> } else {
>> char[] coeff = new char[len]; // allocate char[]
>> // ...
>> }
>>
>>
>> This PR eliminates the two memory allocations mentioned above, resulting in
>> an approximate 60% increase in performance..
>
> Shaojin Wen has updated the pull request incrementally with one additional
> commit since the last revision:
>
> one CharArraySequence
test/micro/org/openjdk/bench/java/math/BigDecimals.java line 103:
> 101: stringInputs[i] = "" + value;
> 102: stringHugeInputs[i] = "" + -(i + 1) * 5434543453454355e100;
> 103: stringLargeInputs[i] = "" + -(i + 1) * 5434543453454355e100;
These two are the same?
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PR Review Comment: https://git.openjdk.org/jdk/pull/18177#discussion_r1522286067
