On Thu, 30 May 2024 15:48:50 GMT, Scott Gibbons <sgibb...@openjdk.org> wrote:
>> Re-write the IndexOf code without the use of the pcmpestri instruction, only
>> using AVX2 instructions. This change accelerates String.IndexOf on average
>> 1.3x for AVX2. The benchmark numbers:
>>
>>
>> Benchmark Score
>> Latest
>> StringIndexOf.advancedWithMediumSub 343.573 317.934
>> 0.925375393x
>> StringIndexOf.advancedWithShortSub1 1039.081 1053.96
>> 1.014319384x
>> StringIndexOf.advancedWithShortSub2 55.828 110.541
>> 1.980027943x
>> StringIndexOf.constantPattern 9.361 11.906
>> 1.271872663x
>> StringIndexOf.searchCharLongSuccess 4.216 4.218
>> 1.000474383x
>> StringIndexOf.searchCharMediumSuccess 3.133 3.216
>> 1.02649218x
>> StringIndexOf.searchCharShortSuccess 3.76 3.761
>> 1.000265957x
>> StringIndexOf.success 9.186
>> 9.713 1.057369911x
>> StringIndexOf.successBig 14.341 46.343
>> 3.231504079x
>> StringIndexOfChar.latin1_AVX2_String 6220.918 12154.52
>> 1.953814533x
>> StringIndexOfChar.latin1_AVX2_char 5503.556 5540.044
>> 1.006629895x
>> StringIndexOfChar.latin1_SSE4_String 6978.854 6818.689
>> 0.977049957x
>> StringIndexOfChar.latin1_SSE4_char 5657.499 5474.624
>> 0.967675646x
>> StringIndexOfChar.latin1_Short_String 7132.541
>> 6863.359 0.962260014x
>> StringIndexOfChar.latin1_Short_char 16013.389 16162.437
>> 1.009307711x
>> StringIndexOfChar.latin1_mixed_String 7386.123 14771.622
>> 1.999915517x
>> StringIndexOfChar.latin1_mixed_char 9901.671 9782.245
>> 0.987938803
>
> Scott Gibbons has updated the pull request incrementally with one additional
> commit since the last revision:
>
> Fix bug number in tests
Ok, now it is good for me. But I would definately wait with integration for
after the fork next week.
src/hotspot/cpu/x86/c2_stubGenerator_x86_64_string.cpp line 2:
> 1: /*
> 2: * Copyright (c) 2023, 2024 Intel Corporation. All rights reserved.
Is the 2023 year intentional? I don't know your policy, so you can just ignore
this ;)
src/hotspot/cpu/x86/c2_stubGenerator_x86_64_string.cpp line 334:
> 332: // NUMBER_OF_CASES (currently 10) needle sizes for both big and small.
> There are special
> 333: // routines for handling needle sizes > NUMBER_OF_CASES
> (L_{big,small}CaseDefault). These
> 334: // cases use C@'s arrays_equals() to compare the needle to the
> haystack. The small cases
Suggestion:
// cases use C2's arrays_equals() to compare the needle to the haystack. The
small cases
Randomly spotted this.
src/hotspot/cpu/x86/c2_stubGenerator_x86_64_string.cpp line 773:
> 771: // jae done
> 772: //
> 773: // Final index of start of needle @((16 - (ndlLen %16)) & 0xf) << 1
What is the meaning of the `@`? Maybe `at`. I'd use the same consistently
-------------
Marked as reviewed by epeter (Reviewer).
PR Review: https://git.openjdk.org/jdk/pull/16753#pullrequestreview-2088739965
PR Review Comment: https://git.openjdk.org/jdk/pull/16753#discussion_r1621015782
PR Review Comment: https://git.openjdk.org/jdk/pull/16753#discussion_r1621017548
PR Review Comment: https://git.openjdk.org/jdk/pull/16753#discussion_r1621019611
