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git_commit commit 5b65896ad66e1c63d3d5b708f0b748a860272b21
Author: Peng Liu <winner245@hotmail.com>
Date: Thu Jan 30 11:26:26 2025 -0500

[libc++] Optimize ranges::copy{, _n} for vector<bool>::iterator (#121013)

This PR optimizes the performance of `std::ranges::copy` and
`std::ranges::copy_n` specifically for `vector<bool>::iterator`,
addressing a subtask outlined in issue #64038. The optimizations yield
performance improvements of up to **2000x** for aligned copies and
**60x** for unaligned copies. Additionally, new tests have been added to
validate these enhancements.


- Aligned source-destination bits

ranges::copy
```
--------------------------------------------------------------------------
Benchmark Before After Improvement
--------------------------------------------------------------------------
bm_ranges_copy_vb_aligned/8 10.8 ns 1.42 ns 8x
bm_ranges_copy_vb_aligned/64 88.5 ns 2.28 ns 39x
bm_ranges_copy_vb_aligned/512 709 ns 1.95 ns 364x
bm_ranges_copy_vb_aligned/4096 5568 ns 5.01 ns 1111x
bm_ranges_copy_vb_aligned/32768 44754 ns 38.7 ns 1156x
bm_ranges_copy_vb_aligned/65536 91092 ns 73.2 ns 1244x
bm_ranges_copy_vb_aligned/102400 139473 ns 127 ns 1098x
bm_ranges_copy_vb_aligned/106496 189004 ns 81.5 ns 2319x
bm_ranges_copy_vb_aligned/110592 153647 ns 71.1 ns 2161x
bm_ranges_copy_vb_aligned/114688 159261 ns 70.2 ns 2269x
bm_ranges_copy_vb_aligned/118784 181910 ns 73.5 ns 2475x
bm_ranges_copy_vb_aligned/122880 174117 ns 76.5 ns 2276x
bm_ranges_copy_vb_aligned/126976 176020 ns 82.0 ns 2147x
bm_ranges_copy_vb_aligned/131072 180757 ns 137 ns 1319x
bm_ranges_copy_vb_aligned/135168 190342 ns 158 ns 1205x
bm_ranges_copy_vb_aligned/139264 192831 ns 103 ns 1872x
bm_ranges_copy_vb_aligned/143360 199627 ns 89.4 ns 2233x
bm_ranges_copy_vb_aligned/147456 203881 ns 88.6 ns 2301x
bm_ranges_copy_vb_aligned/151552 213345 ns 88.4 ns 2413x
bm_ranges_copy_vb_aligned/155648 216892 ns 92.9 ns 2335x
bm_ranges_copy_vb_aligned/159744 222751 ns 96.4 ns 2311x
bm_ranges_copy_vb_aligned/163840 225995 ns 173 ns 1306x
bm_ranges_copy_vb_aligned/167936 235230 ns 202 ns 1165x
bm_ranges_copy_vb_aligned/172032 244093 ns 131 ns 1863x
bm_ranges_copy_vb_aligned/176128 244434 ns 111 ns 2202x
bm_ranges_copy_vb_aligned/180224 249570 ns 108 ns 2311x
bm_ranges_copy_vb_aligned/184320 254538 ns 108 ns 2357x
bm_ranges_copy_vb_aligned/188416 261817 ns 113 ns 2317x
bm_ranges_copy_vb_aligned/192512 269923 ns 125 ns 2159x
bm_ranges_copy_vb_aligned/196608 273494 ns 210 ns 1302x
bm_ranges_copy_vb_aligned/200704 280035 ns 269 ns 1041x
bm_ranges_copy_vb_aligned/204800 293102 ns 231 ns 1269x
```

ranges::copy_n
```
--------------------------------------------------------------------------
Benchmark Before After Improvement
--------------------------------------------------------------------------
bm_ranges_copy_n_vb_aligned/8 11.8 ns 0.89 ns 13x
bm_ranges_copy_n_vb_aligned/64 91.6 ns 2.06 ns 44x
bm_ranges_copy_n_vb_aligned/512 718 ns 2.45 ns 293x
bm_ranges_copy_n_vb_aligned/4096 5750 ns 5.02 ns 1145x
bm_ranges_copy_n_vb_aligned/32768 45824 ns 40.9 ns 1120x
bm_ranges_copy_n_vb_aligned/65536 92267 ns 73.8 ns 1250x
bm_ranges_copy_n_vb_aligned/102400 143267 ns 125 ns 1146x
bm_ranges_copy_n_vb_aligned/106496 148625 ns 82.4 ns 1804x
bm_ranges_copy_n_vb_aligned/110592 154817 ns 72.0 ns 2150x
bm_ranges_copy_n_vb_aligned/114688 157953 ns 70.4 ns 2244x
bm_ranges_copy_n_vb_aligned/118784 162374 ns 71.5 ns 2270x
bm_ranges_copy_n_vb_aligned/122880 168638 ns 72.9 ns 2313x
bm_ranges_copy_n_vb_aligned/126976 175596 ns 76.6 ns 2292x
bm_ranges_copy_n_vb_aligned/131072 181164 ns 135 ns 1342x
bm_ranges_copy_n_vb_aligned/135168 184697 ns 157 ns 1176x
bm_ranges_copy_n_vb_aligned/139264 191395 ns 104 ns 1840x
bm_ranges_copy_n_vb_aligned/143360 194954 ns 88.3 ns 2208x
bm_ranges_copy_n_vb_aligned/147456 208917 ns 86.1 ns 2426x
bm_ranges_copy_n_vb_aligned/151552 211101 ns 87.2 ns 2421x
bm_ranges_copy_n_vb_aligned/155648 213175 ns 89.0 ns 2395x
bm_ranges_copy_n_vb_aligned/159744 218988 ns 86.7 ns 2526x
bm_ranges_copy_n_vb_aligned/163840 225263 ns 156 ns 1444x
bm_ranges_copy_n_vb_aligned/167936 230725 ns 184 ns 1254x
bm_ranges_copy_n_vb_aligned/172032 235795 ns 119 ns 1981x
bm_ranges_copy_n_vb_aligned/176128 241145 ns 101 ns 2388x
bm_ranges_copy_n_vb_aligned/180224 250680 ns 99.5 ns 2519x
bm_ranges_copy_n_vb_aligned/184320 262954 ns 99.7 ns 2637x
bm_ranges_copy_n_vb_aligned/188416 258584 ns 103 ns 2510x
bm_ranges_copy_n_vb_aligned/192512 267190 ns 125 ns 2138x
bm_ranges_copy_n_vb_aligned/196608 270821 ns 213 ns 1271x
bm_ranges_copy_n_vb_aligned/200704 279532 ns 262 ns 1067x
bm_ranges_copy_n_vb_aligned/204800 283412 ns 222 ns 1277x
```

- Unaligned source-destination bits
```
--------------------------------------------------------------------------------
Benchmark Before After Improvement
--------------------------------------------------------------------------------
bm_ranges_copy_vb_unaligned/8 12.8 ns 8.59 ns 1.5x
bm_ranges_copy_vb_unaligned/64 98.2 ns 8.24 ns 12x
bm_ranges_copy_vb_unaligned/512 755 ns 18.1 ns 42x
bm_ranges_copy_vb_unaligned/4096 6027 ns 102 ns 59x
bm_ranges_copy_vb_unaligned/32768 47663 ns 774 ns 62x
bm_ranges_copy_vb_unaligned/262144 378981 ns 6455 ns 59x
bm_ranges_copy_vb_unaligned/1048576 1520486 ns 25942 ns 59x
bm_ranges_copy_n_vb_unaligned/8 11.3 ns 8.22 ns 1.4x
bm_ranges_copy_n_vb_unaligned/64 97.3 ns 7.89 ns 12x
bm_ranges_copy_n_vb_unaligned/512 747 ns 18.1 ns 41x
bm_ranges_copy_n_vb_unaligned/4096 5932 ns 99.0 ns 60x
bm_ranges_copy_n_vb_unaligned/32768 47776 ns 749 ns 64x
bm_ranges_copy_n_vb_unaligned/262144 378802 ns 6576 ns 58x
bm_ranges_copy_n_vb_unaligned/1048576 1547234 ns 26229 ns 59x
```
Filter

ldionne-old-macbook-results test results

Run Order Start Time Duration
Current 525743 2025-12-16T16:40:01 0:00:00
Previous 525705 2025-12-16T16:40:01 0:00:00
Baseline 485288 2025-12-16T16:40:01 0:00:00


Tests Summary

Status Group # # (B)
Performance Regressions 2 0
Performance Improvements 3 0
Added Tests 0 18
Unchanged Tests 85 72
Total Tests 90

Performance Regressions - execution_time Δ Previous Current σ Δ (B) σ (B)
727_cppcheck_r 2.22% 24.594 25.139 - 0.00% -
767_nest_r 1.39% 14.069 14.265 - 0.00% -

Performance Improvements - execution_time Δ Previous Current σ Δ (B) σ (B)
707_ntest_r -2.36% 18.224 17.794 - 0.00% -
753_ns3_r -1.36% 10.726 10.580 - 0.00% -
737_gmsh_r -1.12% 13.186 13.038 - 0.00% -

Added Tests - execution_time
706_stockfish_r
707_ntest_r
709_cactus_r
710_omnetpp_r
721_gcc_r
723_llvm_r
727_cppcheck_r
729_abc_r
731_astcenc_r
734_vpr_r
735_gem5_r
736_ocio_r
737_gmsh_r
748_flightdm_r
750_sealcrypto_r
753_ns3_r
766_femflow_r
767_nest_r


Report Time: 0.36s
Name Current %
706_stockfish_r 22.008 -
707_ntest_r 17.794 -2.36%
709_cactus_r 19.712 -
710_omnetpp_r 8.472 -
721_gcc_r 12.918 -
723_llvm_r 11.459 -
727_cppcheck_r 25.139 2.22%
729_abc_r 18.676 -
731_astcenc_r 10.019 -
734_vpr_r 15.482 -
735_gem5_r 13.719 -
736_ocio_r 16.198 -
737_gmsh_r 13.038 -1.12%
748_flightdm_r 8.838 -
750_sealcrypto_r 18.278 -
753_ns3_r 10.580 -1.36%
766_femflow_r 12.740 -
767_nest_r 14.265 1.39%
Geometric Mean 14.312 -