On Sat, 8 Jun 2024 15:51:13 GMT, Brett Okken <[email protected]> wrote:
>> Shaojin Wen has updated the pull request incrementally with one additional
>> commit since the last revision:
>>
>> add comments
>
> src/java.base/share/classes/jdk/internal/util/HexDigits.java line 117:
>
>> 115:
>> 116: /**
>> 117: * Insert the int into the buffer as 4 hexadecimal digits
>
> 4 hex digits is 2 bytes, right?
> should this take a short instead?
> At a minimum, seems documentation should be clear as to which 2 bytes are
> used.
Yes, 4 hex digits requires 2 bytes of input integer; we always take the least
significant bytes. I think taking an int is better than taking a short, as
subint types are int in bytecode, and short's signedness may be bug-prone.
> src/java.base/share/classes/jdk/internal/util/HexDigits.java line 122:
>
>> 120: * @param value to convert
>> 121: */
>> 122: public static void putHex(byte[] buffer, int off, int i) {
>
> Should there be 2 methods - for 2 and 4 bytes respectively?
> Does c2 optimize 8 byte writes as well?
The 4-byte unsigned int input for 8-byte write sounds plausible, I personally
am fine either with or without it.
> Does c2 optimize 8 byte writes as well?
>From the first few lines of #16245:
> Merging multiple consecutive small stores (e.g. 8 byte stores) into larger
> stores (e.g. one long store) can lead to speedup.
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PR Review Comment: https://git.openjdk.org/jdk/pull/19610#discussion_r1632081700
PR Review Comment: https://git.openjdk.org/jdk/pull/19610#discussion_r1632082369
