On Tue, 14 Feb 2023 01:48:37 GMT, Sandhya Viswanathan
<sviswanat...@openjdk.org> wrote:
>> Scott Gibbons has updated the pull request incrementally with one additional
>> commit since the last revision:
>>
>> Add URL to microbenchmark
>
> src/hotspot/cpu/x86/stubGenerator_x86_64.cpp line 2399:
>
>> 2397: VM_Version::supports_avx512bw()) {
>> 2398: __ cmpl(length, 31); // 32-bytes is break-even for AVX-512
>> 2399: __ jcc(Assembler::lessEqual, L_bruteForce);
>
> The avx2 code needs the length to be atleast 0x2c (44) bytes. We could
> directly go to non-avx code instead of L_bruteForce here. We will save one
> subtract/branch.
Done.
> src/hotspot/cpu/x86/stubGenerator_x86_64.cpp line 2658:
>
>> 2656: // Check for buffer too small (for algorithm)
>> 2657: __ subl(length, 0x2c);
>> 2658: __ jcc(Assembler::lessEqual, L_tailProc);
>
> This could be Assembler::less instead of Assembler::lessEqual.
Why? There is no performance difference and the intent is clear. Is this just
a "style" thing?
> src/hotspot/cpu/x86/stubGenerator_x86_64.cpp line 2699:
>
>> 2697: __ addptr(dest, 0x18);
>> 2698: __ subl(length, 0x20);
>> 2699: __ jcc(Assembler::lessEqual, L_tailProc);
>
> This could be Assembler::less instead of Assembler::lessEqual.
Why? There is no performance difference and the intent is clear. Is this just
a "style" thing?
-------------
PR: https://git.openjdk.org/jdk/pull/12126
