On Tue, 12 Mar 2024 10:34:33 GMT, Shaojin Wen <[email protected]> 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:
>
> refactor CharArraySequence
src/java.base/share/classes/java/math/BigDecimal.java line 846:
> 844: @Override
> 845: public char charAt(int offset) {
> 846: return array[offset];
Good refactor and correctness fix to change this to `offset, length`, but this
method looks incorrect now. The parameter should be the `offset`-relative
index, no?
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PR Review Comment: https://git.openjdk.org/jdk/pull/18177#discussion_r1521303532
