RFR: 8310929: Optimization for Integer.toString [v12]

[Chen Liang]

On Tue, 18 Jul 2023 01:26:55 GMT, 温绍锦 <duke at openjdk.org> wrote:

>> src/java.base/share/classes/java/lang/Integer.java line 528:
>> 
>>> 526:             i = q;
>>> 527:             charPos -= 2;
>>> 528:             UNSAFE.putShortUnaligned(buf, Unsafe.ARRAY_BYTE_BASE_OFFSET + charPos, PACKED_DIGITS[r], false);
>> 
>> When switching to use Unsafe, `getChars` should do the array bounds check in the loop of the store index.
>
> The value range of the r variable is 0-99, and the length of PACKED_DIGITS is 100, There is no need to check the array boundary here.

I think he means to check the `charPos` to ensure it is not out of bounds.

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PR Review Comment: https://git.openjdk.org/jdk/pull/14699#discussion_r1266080264