RFR: 8320448: Accelerate IndexOf using AVX2 [v20]

[Scott Gibbons]

On Tue, 21 May 2024 22:39:42 GMT, Sandhya Viswanathan <sviswanathan at openjdk.org> wrote:

>> Scott Gibbons has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Addressing lots of comments.  Interim commit.
>
> src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp line 4737:
> 
>> 4735:     bind(COMPARE_BYTE);
>> 4736:   } else {
>> 4737:     lea(ary1, Address(ary1, expand_ary2 ? 4 : 2));
> 
> This change is not required. expand_ary2 code doesn't come here.

Right.  Fixed.

> src/hotspot/cpu/x86/stubGenerator_x86_64_string.cpp line 1233:
> 
>> 1231:   __ andq(eq_mask, rTmp);
>> 1232: 
>> 1233:   __ testl(eq_mask, eq_mask);
> 
> Mismatch of operation size q vs l: andq and testl.

Fixed.

> src/hotspot/cpu/x86/stubGenerator_x86_64_string.cpp line 1623:
> 
>> 1621:     ////////////////////////////////////////////////////////////////////////////////////////
>> 1622:     //
>> 1623:     // Small haystack (<32 bytes) switch
> 
> This should be <= 32 bytes.

Fixed.

> src/hotspot/cpu/x86/stubGenerator_x86_64_string.cpp line 1709:
> 
>> 1707:     //  XMM_BYTE_K - last element of needle, broadcast
>> 1708:     //
>> 1709:     //  The haystack is >= 32 bytes
> 
> Should this be > 32 bytes?

Fixed.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/16753#discussion_r1614114763
PR Review Comment: https://git.openjdk.org/jdk/pull/16753#discussion_r1614127986
PR Review Comment: https://git.openjdk.org/jdk/pull/16753#discussion_r1614127889
PR Review Comment: https://git.openjdk.org/jdk/pull/16753#discussion_r1614127781