This PR proposes to rewrite the `StringSupport::chunkedStrlen*` methods and move them to the class `SegmentBulkOperations` where other bulk operations reside.
This PR fixes a bug in the `short_strlen` variant for offsets that were odd (`offset % 2 != 0`). This PR also improves performance on modern hardware, as there is no need for pre-looping alignment. Removing this improves performance by about 30% for larger strings. Passes the `jdk_foreign` test suit. Base: Benchmark (size) Mode Cnt Score Error Units InternalStrLen.changedElementQuad 1 avgt 30 2.057 ? 0.012 ns/op InternalStrLen.changedElementQuad 4 avgt 30 3.776 ? 0.031 ns/op InternalStrLen.changedElementQuad 16 avgt 30 6.690 ? 0.060 ns/op InternalStrLen.changedElementQuad 251 avgt 30 48.581 ? 0.764 ns/op InternalStrLen.changedElementQuad 1024 avgt 30 196.188 ? 3.484 ns/op InternalStrLen.chunkedDouble 1 avgt 30 1.903 ? 0.013 ns/op InternalStrLen.chunkedDouble 4 avgt 30 3.446 ? 0.025 ns/op InternalStrLen.chunkedDouble 16 avgt 30 5.759 ? 0.062 ns/op InternalStrLen.chunkedDouble 251 avgt 30 26.892 ? 0.141 ns/op InternalStrLen.chunkedDouble 1024 avgt 30 72.940 ? 1.562 ns/op InternalStrLen.chunkedSingle 1 avgt 30 1.897 ? 0.015 ns/op InternalStrLen.chunkedSingle 4 avgt 30 5.357 ? 0.560 ns/op InternalStrLen.chunkedSingle 16 avgt 30 3.821 ? 0.052 ns/op InternalStrLen.chunkedSingle 251 avgt 30 19.482 ? 0.190 ns/op InternalStrLen.chunkedSingle 1024 avgt 30 38.938 ? 0.411 ns/op InternalStrLen.chunkedSingleMisaligned 1 avgt 30 2.230 ? 0.147 ns/op InternalStrLen.chunkedSingleMisaligned 4 avgt 30 5.424 ? 0.688 ns/op InternalStrLen.chunkedSingleMisaligned 16 avgt 30 9.573 ? 0.063 ns/op InternalStrLen.chunkedSingleMisaligned 251 avgt 30 22.242 ? 0.182 ns/op InternalStrLen.chunkedSingleMisaligned 1024 avgt 30 45.442 ? 0.252 ns/op InternalStrLen.elementByteMisaligned 1 avgt 30 1.616 ? 0.041 ns/op InternalStrLen.elementByteMisaligned 4 avgt 30 2.982 ? 0.018 ns/op InternalStrLen.elementByteMisaligned 16 avgt 30 8.662 ? 0.085 ns/op InternalStrLen.elementByteMisaligned 251 avgt 30 126.644 ? 0.902 ns/op InternalStrLen.elementByteMisaligned 1024 avgt 30 492.736 ? 3.254 ns/op InternalStrLen.elementDouble 1 avgt 30 1.900 ? 0.016 ns/op InternalStrLen.elementDouble 4 avgt 30 3.931 ? 0.027 ns/op InternalStrLen.elementDouble 16 avgt 30 12.310 ? 0.109 ns/op InternalStrLen.elementDouble 251 avgt 30 203.665 ? 6.778 ns/op InternalStrLen.elementDouble 1024 avgt 30 786.320 ? 5.104 ns/op InternalStrLen.elementQuad 1 avgt 30 1.922 ? 0.031 ns/op InternalStrLen.elementQuad 4 avgt 30 4.078 ? 0.175 ns/op InternalStrLen.elementQuad 16 avgt 30 12.538 ? 0.330 ns/op InternalStrLen.elementQuad 251 avgt 30 202.175 ? 3.537 ns/op InternalStrLen.elementQuad 1024 avgt 30 798.846 ? 7.323 ns/op InternalStrLen.elementSingle 1 avgt 30 1.614 ? 0.045 ns/op InternalStrLen.elementSingle 4 avgt 30 2.992 ? 0.010 ns/op InternalStrLen.elementSingle 16 avgt 30 8.773 ? 0.095 ns/op InternalStrLen.elementSingle 251 avgt 30 126.975 ? 1.201 ns/op InternalStrLen.elementSingle 1024 avgt 30 499.057 ? 6.561 ns/op Patch: Benchmark (size) Mode Cnt Score Error Units InternalStrLen.changedElementQuad 1 avgt 30 1.386 ? 0.026 ns/op InternalStrLen.changedElementQuad 4 avgt 30 3.467 ? 0.026 ns/op InternalStrLen.changedElementQuad 16 avgt 30 5.551 ? 0.118 ns/op InternalStrLen.changedElementQuad 251 avgt 30 37.737 ? 0.197 ns/op InternalStrLen.changedElementQuad 1024 avgt 30 180.656 ? 3.920 ns/op InternalStrLen.chunkedDouble 1 avgt 30 2.211 ? 0.022 ns/op InternalStrLen.chunkedDouble 4 avgt 30 2.517 ? 0.024 ns/op InternalStrLen.chunkedDouble 16 avgt 30 3.763 ? 0.024 ns/op InternalStrLen.chunkedDouble 251 avgt 30 22.641 ? 0.790 ns/op InternalStrLen.chunkedDouble 1024 avgt 30 67.525 ? 1.468 ns/op InternalStrLen.chunkedSingle 1 avgt 30 2.360 ? 0.187 ns/op InternalStrLen.chunkedSingle 4 avgt 30 2.846 ? 0.035 ns/op InternalStrLen.chunkedSingle 16 avgt 30 3.450 ? 0.014 ns/op InternalStrLen.chunkedSingle 251 avgt 30 12.478 ? 0.055 ns/op InternalStrLen.chunkedSingle 1024 avgt 30 34.528 ? 0.338 ns/op InternalStrLen.chunkedSingleMisaligned 1 avgt 30 2.505 ? 0.013 ns/op InternalStrLen.chunkedSingleMisaligned 4 avgt 30 3.305 ? 0.063 ns/op InternalStrLen.chunkedSingleMisaligned 16 avgt 30 3.962 ? 0.083 ns/op InternalStrLen.chunkedSingleMisaligned 251 avgt 30 12.971 ? 0.396 ns/op InternalStrLen.chunkedSingleMisaligned 1024 avgt 30 35.891 ? 1.048 ns/op InternalStrLen.elementByteMisaligned 1 avgt 30 1.495 ? 0.042 ns/op InternalStrLen.elementByteMisaligned 4 avgt 30 2.898 ? 0.079 ns/op InternalStrLen.elementByteMisaligned 16 avgt 30 8.632 ? 0.212 ns/op InternalStrLen.elementByteMisaligned 251 avgt 30 128.452 ? 3.210 ns/op InternalStrLen.elementByteMisaligned 1024 avgt 30 508.724 ? 18.041 ns/op InternalStrLen.elementDouble 1 avgt 30 1.852 ? 0.092 ns/op InternalStrLen.elementDouble 4 avgt 30 3.838 ? 0.099 ns/op InternalStrLen.elementDouble 16 avgt 30 12.361 ? 0.327 ns/op InternalStrLen.elementDouble 251 avgt 30 206.742 ? 10.447 ns/op InternalStrLen.elementDouble 1024 avgt 30 793.779 ? 7.499 ns/op InternalStrLen.elementQuad 1 avgt 30 1.790 ? 0.056 ns/op InternalStrLen.elementQuad 4 avgt 30 3.732 ? 0.009 ns/op InternalStrLen.elementQuad 16 avgt 30 12.067 ? 0.250 ns/op InternalStrLen.elementQuad 251 avgt 30 196.458 ? 2.688 ns/op InternalStrLen.elementQuad 1024 avgt 30 811.230 ? 27.569 ns/op InternalStrLen.elementSingle 1 avgt 30 1.465 ? 0.036 ns/op InternalStrLen.elementSingle 4 avgt 30 2.875 ? 0.068 ns/op InternalStrLen.elementSingle 16 avgt 30 8.568 ? 0.176 ns/op InternalStrLen.elementSingle 251 avgt 30 126.605 ? 2.811 ns/op InternalStrLen.elementSingle 1024 avgt 30 494.017 ? 10.106 ns/op ------------- Commit messages: - Clean up - Add int method - Fix benchmark - Move and rewrite strlen methods Changes: https://git.openjdk.org/jdk/pull/22451/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22451&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8345120 Stats: 462 lines in 5 files changed: 212 ins; 183 del; 67 mod Patch: https://git.openjdk.org/jdk/pull/22451.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/22451/head:pull/22451 PR: https://git.openjdk.org/jdk/pull/22451
