RFR: 8320448: Accelerate IndexOf using AVX2 [v27]

[Scott Gibbons]

On Wed, 22 May 2024 20:36:25 GMT, Sandhya Viswanathan <sviswanathan at openjdk.org> wrote:

>> Scott Gibbons has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Revert last change to IndexOf.java
>
> src/hotspot/cpu/x86/stubGenerator_x86_64_string.cpp line 1218:
> 
>> 1216: // isU - true if argument encoding is either UU or UL
>> 1217: // eq_mask - The bit mask returned that holds the result of the comparison
>> 1218: // needleLen - a temporary register.  Only used if isUL true
> 
> needleLen is not a temporary register. needleLen is used to read the kThByte from haystack below when !sizeKnown so must hold valid info.

Fixed.

> src/hotspot/cpu/x86/stubGenerator_x86_64_string.cpp line 1439:
> 
>> 1437:   // back to last valid read position
>> 1438:   __ cmpq(hsPtrRet, last);
>> 1439:   __ jb_b(L_midLoop);
> 
> could be  jbe_b?

Fixed.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/16753#discussion_r1614127526
PR Review Comment: https://git.openjdk.org/jdk/pull/16753#discussion_r1614127356