Full Text Bug Listing

Jarred Sumner

Reported 2022-09-28 14:12:17 PDT

Created attachment 462692 [details] array-map.mjs A lot of modern JS uses .map and .forEach. Many codebases use these functions more frequently than for loops. For small array literals with constant values, V8 is about 3x faster than what JSC is doing. I've attached a benchmark script Bun using a copy of JSC from September 17th, 2022: cpu: Apple M1 Max runtime: bun 0.1.14 (arm64-darwin) benchmark time (avg) (min … max) p75 p99 p995 ------------------------------------------------------------- ----------------------------- Array.map x 0 50.91 ns/iter (45.7 ns … 274.74 ns) 47.35 ns 113.15 ns 131.34 ns Array.map x 1 55.15 ns/iter (51.91 ns … 453.84 ns) 52.44 ns 101.3 ns 119.57 ns Array.map x 2 58.1 ns/iter (51.91 ns … 183.54 ns) 52.77 ns 116.05 ns 151.96 ns Array.map x 3 52.16 ns/iter (46.56 ns … 152.19 ns) 47.15 ns 105.3 ns 125.74 ns Array.map x 4 78.14 ns/iter (51.94 ns … 164.94 ns) 83.45 ns 129.8 ns 139.77 ns Array.map x 5 54.94 ns/iter (51.36 ns … 226.1 ns) 53.67 ns 101.87 ns 109.88 ns Array.map x 6 55.97 ns/iter (51.9 ns … 257.6 ns) 54.43 ns 105.08 ns 165.98 ns Array.map x 7 55.5 ns/iter (51.84 ns … 162.09 ns) 54.43 ns 102.56 ns 112.98 ns Array.map x 8 57.03 ns/iter (51.84 ns … 476.93 ns) 54.97 ns 121.98 ns 148.4 ns Array.map x 9 56.4 ns/iter (51.85 ns … 370.1 ns) 54.74 ns 116.15 ns 131.97 ns Array.map x 10 56.05 ns/iter (51.86 ns … 212.73 ns) 54.53 ns 103.42 ns 108.92 ns Array.map x 11 55.92 ns/iter (51.86 ns … 187.18 ns) 54.53 ns 103.99 ns 133.61 ns Array.map x 12 55.93 ns/iter (51.88 ns … 272.41 ns) 54.48 ns 107.03 ns 120.77 ns Array.map x 13 56.08 ns/iter (51.86 ns … 174.88 ns) 54.64 ns 115.71 ns 127.24 ns Array.map x 14 55.97 ns/iter (51.88 ns … 191.69 ns) 54.55 ns 110.09 ns 119.5 ns Array.map x 15 55.87 ns/iter (51.86 ns … 357.33 ns) 54.51 ns 102.73 ns 111.7 ns Array.map x 16 55.98 ns/iter (51.85 ns … 181.74 ns) 54.52 ns 106.4 ns 117.05 ns Array.map x 17 56.25 ns/iter (51.88 ns … 380.5 ns) 54.54 ns 106.85 ns 117.7 ns Array.map x 18 55.41 ns/iter (51.85 ns … 127.13 ns) 54.54 ns 97.5 ns 103.66 ns Array.map x 19 55.73 ns/iter (51.87 ns … 267.85 ns) 54.61 ns 100.46 ns 106.79 ns inline Array.map x 0 31.8 ns/iter (28.91 ns … 239.6 ns) 31.2 ns 73.13 ns 84.8 ns inline Array.map x 1 33.6 ns/iter (30.74 ns … 106.19 ns) 33.89 ns 77.63 ns 90.15 ns inline Array.map x 2 34.59 ns/iter (31.94 ns … 239.49 ns) 34.82 ns 75.1 ns 85.36 ns inline Array.map x 3 36.49 ns/iter (33.39 ns … 151.94 ns) 36.17 ns 79.87 ns 93.93 ns inline Array.map x 4 38.94 ns/iter (35.6 ns … 295.58 ns) 38.79 ns 87.57 ns 93.78 ns inline Array.map x 5 40.37 ns/iter (36.88 ns … 268.68 ns) 39.93 ns 92.47 ns 97.58 ns inline Array.map x 6 43.33 ns/iter (39.58 ns … 272.25 ns) 42.77 ns 93.85 ns 101.4 ns inline Array.map x 7 44.73 ns/iter (40.56 ns … 505.39 ns) 43.34 ns 99.42 ns 138.26 ns inline Array.map x 8 41.82 ns/iter (37.98 ns … 161.33 ns) 41.22 ns 89.9 ns 98.47 ns inline Array.map x 9 42.2 ns/iter (38.85 ns … 104.19 ns) 41.62 ns 87.07 ns 92.6 ns inline Array.map x 10 54.53 ns/iter (49.97 ns … 185.29 ns) 53.61 ns 105.6 ns 113.41 ns inline Array.map x 11 55.63 ns/iter (50.92 ns … 251.47 ns) 54.47 ns 103.83 ns 173.58 ns inline Array.map x 12 56.66 ns/iter (51.74 ns … 278.88 ns) 56.14 ns 105.58 ns 107.75 ns inline Array.map x 13 57.31 ns/iter (52.67 ns … 212.94 ns) 56.72 ns 103.72 ns 115.22 ns inline Array.map x 14 53.85 ns/iter (48.2 ns … 203.39 ns) 54 ns 107.08 ns 115.79 ns inline Array.map x 15 55.64 ns/iter (48.61 ns … 265.81 ns) 55.93 ns 107.91 ns 114.97 ns inline Array.map x 16 56.43 ns/iter (49.25 ns … 408.1 ns) 55.23 ns 111.18 ns 137.67 ns inline Array.map x 17 57.4 ns/iter (50.05 ns … 143.59 ns) 56.14 ns 110.2 ns 116.92 ns inline Array.map x 18 58.43 ns/iter (51.64 ns … 267.74 ns) 58.65 ns 112.74 ns 121.68 ns inline Array.map x 19 59.89 ns/iter (51.9 ns … 476.5 ns) 59.19 ns 109.14 ns 112.25 ns Node v18.9.1: benchmark time (avg) (min … max) p75 p99 p995 ------------------------------------------------------------- ----------------------------- Array.map x 0 34.04 ns/iter (29.44 ns … 467.84 ns) 33.85 ns 42.88 ns 43.56 ns Array.map x 1 40.11 ns/iter (30.09 ns … 244.13 ns) 41.4 ns 109.83 ns 130.5 ns Array.map x 2 35.94 ns/iter (25.49 ns … 533.06 ns) 39.04 ns 47.24 ns 47.97 ns Array.map x 3 34.42 ns/iter (28.05 ns … 42.55 ns) 35.67 ns 39.95 ns 40.68 ns Array.map x 4 32.94 ns/iter (28 ns … 45.35 ns) 33.4 ns 38.43 ns 40.02 ns Array.map x 5 36.87 ns/iter (28.02 ns … 51.1 ns) 38.55 ns 45.81 ns 47.34 ns Array.map x 6 34.6 ns/iter (28.05 ns … 47.17 ns) 36.35 ns 41.41 ns 42.43 ns Array.map x 7 32.59 ns/iter (28 ns … 40.6 ns) 32.58 ns 37.35 ns 38.05 ns Array.map x 8 32.49 ns/iter (28.05 ns … 45.3 ns) 32.5 ns 36.84 ns 37.49 ns Array.map x 9 32.61 ns/iter (28 ns … 49.33 ns) 32.5 ns 38.6 ns 42.77 ns Array.map x 10 32.45 ns/iter (28.01 ns … 39.56 ns) 32.42 ns 36.15 ns 36.83 ns Array.map x 11 34.8 ns/iter (28.02 ns … 404.71 ns) 34.34 ns 66.5 ns 84.86 ns Array.map x 12 32.45 ns/iter (28.02 ns … 46.71 ns) 32.46 ns 35.9 ns 37.15 ns Array.map x 13 32.37 ns/iter (27.99 ns … 41.37 ns) 32.42 ns 37.14 ns 38.39 ns Array.map x 14 32.52 ns/iter (27.99 ns … 42.66 ns) 32.52 ns 36.39 ns 38.6 ns Array.map x 15 31.69 ns/iter (28.01 ns … 55.96 ns) 32.58 ns 34.9 ns 39.68 ns Array.map x 16 30.77 ns/iter (28.13 ns … 40.82 ns) 33.07 ns 35.27 ns 36.27 ns Array.map x 17 30.73 ns/iter (28.13 ns … 40.67 ns) 33 ns 35.59 ns 36.96 ns Array.map x 18 30.77 ns/iter (28.13 ns … 39.08 ns) 33.2 ns 34.04 ns 34.35 ns Array.map x 19 31.03 ns/iter (28.11 ns … 46.27 ns) 33.08 ns 37.92 ns 42.6 ns inline Array.map x 0 7.59 ns/iter (6.05 ns … 415.02 ns) 10.49 ns 11.85 ns 13.33 ns inline Array.map x 1 6.01 ns/iter (5.25 ns … 20.8 ns) 5.45 ns 10.9 ns 11.81 ns inline Array.map x 2 7.41 ns/iter (6.56 ns … 15.85 ns) 6.75 ns 11.69 ns 11.84 ns inline Array.map x 3 9.02 ns/iter (8.1 ns … 22.63 ns) 8.31 ns 13.24 ns 13.82 ns inline Array.map x 4 11.25 ns/iter (10.13 ns … 25.14 ns) 10.54 ns 16.12 ns 17.26 ns inline Array.map x 5 12.33 ns/iter (10.62 ns … 22.12 ns) 11.62 ns 16.96 ns 17.82 ns inline Array.map x 6 13.37 ns/iter (11.57 ns … 27.57 ns) 12.72 ns 17.59 ns 18.2 ns inline Array.map x 7 14.45 ns/iter (13.08 ns … 29.82 ns) 17.48 ns 19.14 ns 20.86 ns inline Array.map x 8 15.47 ns/iter (14.03 ns … 25.82 ns) 18.61 ns 19.32 ns 20.18 ns inline Array.map x 9 16.58 ns/iter (15 ns … 33.03 ns) 19.65 ns 20.6 ns 21.1 ns inline Array.map x 10 17.6 ns/iter (15.88 ns … 28.53 ns) 20.45 ns 22.87 ns 23.76 ns inline Array.map x 11 18.26 ns/iter (16.79 ns … 51.02 ns) 21.28 ns 24.35 ns 25.29 ns inline Array.map x 12 18.79 ns/iter (17.72 ns … 35.87 ns) 17.79 ns 23.95 ns 24.26 ns inline Array.map x 13 19.9 ns/iter (18.65 ns … 33.07 ns) 19.28 ns 26.57 ns 29.35 ns inline Array.map x 14 20.79 ns/iter (19.58 ns … 31.04 ns) 19.68 ns 25.87 ns 26.63 ns inline Array.map x 15 21.73 ns/iter (20.52 ns … 40.35 ns) 20.59 ns 26.63 ns 27.52 ns inline Array.map x 16 22.82 ns/iter (21.45 ns … 35.67 ns) 22.2 ns 29.01 ns 30.38 ns inline Array.map x 17 23.75 ns/iter (22.39 ns … 34.28 ns) 22.57 ns 28.8 ns 29.43 ns inline Array.map x 18 24.75 ns/iter (23.32 ns … 35.58 ns) 23.55 ns 29.62 ns 30.4 ns inline Array.map x 19 25.69 ns/iter (24.25 ns … 36.99 ns) 25.53 ns 30.86 ns 31.65 ns

Radar WebKit Bug Importer

Comment 1 2022-09-28 20:27:29 PDT

<rdar://problem/100541275>

Yusuke Suzuki

Comment 2 2022-10-01 03:39:33 PDT

WIP cpu: unknown runtime: unknown (unknown) benchmark time (avg) (min … max) p75 p99 p995 ------------------------------------------------------------- ----------------------------- Array.map x 0 28.49 ns/iter (26.84 ns … 148.08 ns) 27.63 ns 59.3 ns 76.17 ns Array.map x 1 33.21 ns/iter (31.63 ns … 97.94 ns) 32.53 ns 62.02 ns 83.18 ns Array.map x 2 32.17 ns/iter (27.21 ns … 130.01 ns) 31.69 ns 73.57 ns 78.73 ns Array.map x 3 45.48 ns/iter (27.2 ns … 127.62 ns) 69.28 ns 81.28 ns 98.59 ns Array.map x 4 28.96 ns/iter (27.14 ns … 94.2 ns) 28.05 ns 64.62 ns 76.08 ns Array.map x 5 28.55 ns/iter (27.17 ns … 91.72 ns) 28.03 ns 39 ns 64.9 ns Array.map x 6 28.46 ns/iter (27.17 ns … 80.81 ns) 28.04 ns 39.17 ns 57.07 ns Array.map x 7 28.88 ns/iter (27.17 ns … 93.39 ns) 28.1 ns 62.61 ns 72.78 ns Array.map x 8 29.12 ns/iter (27.18 ns … 161.94 ns) 28.07 ns 67.97 ns 82.15 ns Array.map x 9 28.59 ns/iter (27.18 ns … 85.14 ns) 28.05 ns 47 ns 64.41 ns Array.map x 10 28.52 ns/iter (27.19 ns … 78.88 ns) 28.09 ns 39.6 ns 58.16 ns Array.map x 11 29.13 ns/iter (27.17 ns … 110.19 ns) 28.13 ns 79.15 ns 84.6 ns Array.map x 12 29.03 ns/iter (27.15 ns … 91.61 ns) 28.22 ns 65.89 ns 80.31 ns Array.map x 13 29.14 ns/iter (27.18 ns … 93.42 ns) 28.17 ns 69.51 ns 82.66 ns Array.map x 14 29.16 ns/iter (27.16 ns … 99.3 ns) 28.18 ns 70.8 ns 82.09 ns Array.map x 15 29.07 ns/iter (27.18 ns … 94.77 ns) 28.15 ns 65.42 ns 81.82 ns Array.map x 16 29.27 ns/iter (27.17 ns … 97.29 ns) 28.2 ns 71.23 ns 79.35 ns Array.map x 17 29.23 ns/iter (27.19 ns … 97.42 ns) 28.23 ns 67.93 ns 76.22 ns Array.map x 18 29.18 ns/iter (27.17 ns … 91.88 ns) 28.22 ns 71.79 ns 80.78 ns Array.map x 19 29.26 ns/iter (27.2 ns … 94.75 ns) 28.17 ns 71.42 ns 81.85 ns inline Array.map x 0 32.57 ns/iter (31.2 ns … 84.23 ns) 32.45 ns 41.88 ns 47.78 ns inline Array.map x 1 32.66 ns/iter (31.48 ns … 101.39 ns) 32.6 ns 42.28 ns 43.43 ns inline Array.map x 2 33.92 ns/iter (32.6 ns … 91.01 ns) 33.83 ns 44.92 ns 58.12 ns inline Array.map x 3 34.96 ns/iter (33.48 ns … 103.55 ns) 34.86 ns 45.21 ns 54.17 ns inline Array.map x 4 37.74 ns/iter (35.86 ns … 95.65 ns) 37.72 ns 48.17 ns 59.15 ns inline Array.map x 5 38.56 ns/iter (36.45 ns … 100.56 ns) 38.18 ns 54.9 ns 74.98 ns inline Array.map x 6 29.37 ns/iter (28.24 ns … 51.83 ns) 29.28 ns 38.95 ns 39.67 ns inline Array.map x 7 30.77 ns/iter (29.32 ns … 56.58 ns) 30.72 ns 40.22 ns 40.66 ns inline Array.map x 8 27.2 ns/iter (25.83 ns … 82.72 ns) 27.17 ns 37.07 ns 37.49 ns inline Array.map x 9 27.97 ns/iter (26.78 ns … 52.23 ns) 27.91 ns 37.84 ns 38.38 ns inline Array.map x 10 34.38 ns/iter (32.41 ns … 68.93 ns) 34.26 ns 44.48 ns 44.83 ns inline Array.map x 11 36.91 ns/iter (34.84 ns … 79.72 ns) 36.84 ns 47.31 ns 47.94 ns inline Array.map x 12 36.76 ns/iter (34.66 ns … 111.31 ns) 36.54 ns 46.86 ns 47.39 ns inline Array.map x 13 32.41 ns/iter (30.93 ns … 69.17 ns) 32.26 ns 43.06 ns 43.51 ns inline Array.map x 14 33.86 ns/iter (32.17 ns … 76.42 ns) 33.71 ns 43.96 ns 44.37 ns inline Array.map x 15 34.65 ns/iter (33.05 ns … 68.21 ns) 34.45 ns 44.38 ns 44.65 ns inline Array.map x 16 35.84 ns/iter (34.27 ns … 58.6 ns) 35.66 ns 45.48 ns 45.77 ns inline Array.map x 17 36.43 ns/iter (34.9 ns … 61.27 ns) 36.23 ns 46.1 ns 46.3 ns inline Array.map x 18 37.62 ns/iter (36.07 ns … 93.94 ns) 37.4 ns 47.55 ns 47.75 ns inline Array.map x 19 38.46 ns/iter (36.96 ns … 63.12 ns) 38.29 ns 47.67 ns 48.23 ns

Yusuke Suzuki

Comment 3 2022-10-02 00:01:52 PDT

Probably this is good enough since non-inline one is more important use case than inline case. inline one can be improved if we introduce a bit more complicated MovHint analysis. benchmark time (avg) (min … max) p75 p99 p995 ------------------------------------------------------------- ----------------------------- Array.map x 0 24.54 ns/iter (22.94 ns … 131.96 ns) 23.7 ns 52.89 ns 72.85 ns Array.map x 1 29.48 ns/iter (28.38 ns … 91.36 ns) 29.17 ns 39.09 ns 40.02 ns Array.map x 2 27.35 ns/iter (23.62 ns … 108.33 ns) 24.51 ns 68.3 ns 70.45 ns Array.map x 3 39.27 ns/iter (23.61 ns … 136.4 ns) 64.96 ns 76.57 ns 78.4 ns Array.map x 4 24.36 ns/iter (23.29 ns … 49.6 ns) 24.05 ns 34.45 ns 34.77 ns Array.map x 5 24.56 ns/iter (23.29 ns … 76.57 ns) 24.07 ns 36.74 ns 50.33 ns Array.map x 6 24.4 ns/iter (23.31 ns … 35.53 ns) 24.1 ns 34.31 ns 34.61 ns Array.map x 7 24.61 ns/iter (23.29 ns … 84.06 ns) 24.1 ns 34.63 ns 49.02 ns Array.map x 8 24.47 ns/iter (23.29 ns … 65.72 ns) 24.13 ns 34.63 ns 36.55 ns Array.map x 9 24.39 ns/iter (23.27 ns … 35.66 ns) 24.11 ns 34.44 ns 34.56 ns Array.map x 10 24.46 ns/iter (23.28 ns … 68.06 ns) 24.13 ns 34.26 ns 34.59 ns Array.map x 11 24.45 ns/iter (23.28 ns … 87.8 ns) 24.17 ns 34.46 ns 34.82 ns Array.map x 12 24.5 ns/iter (23.28 ns … 70.95 ns) 24.16 ns 34.5 ns 35.24 ns Array.map x 13 24.47 ns/iter (23.28 ns … 75.69 ns) 24.12 ns 34.26 ns 34.57 ns Array.map x 14 24.54 ns/iter (23.29 ns … 89.96 ns) 24.14 ns 34.45 ns 35.22 ns Array.map x 15 24.47 ns/iter (23.28 ns … 57.91 ns) 24.19 ns 34.42 ns 34.66 ns Array.map x 16 24.62 ns/iter (23.29 ns … 69.3 ns) 24.22 ns 34.65 ns 49 ns Array.map x 17 24.6 ns/iter (23.27 ns … 73.38 ns) 24.18 ns 34.9 ns 43.3 ns Array.map x 18 24.65 ns/iter (23.29 ns … 90.89 ns) 24.2 ns 35.15 ns 42.95 ns Array.map x 19 24.58 ns/iter (23.28 ns … 80.27 ns) 24.21 ns 34.79 ns 37.04 ns inline Array.map x 0 19.7 ns/iter (18.96 ns … 33.95 ns) 19.6 ns 28.68 ns 29.1 ns inline Array.map x 1 23.67 ns/iter (22.77 ns … 53.31 ns) 23.57 ns 33.13 ns 33.54 ns inline Array.map x 2 24.75 ns/iter (23.66 ns … 66.57 ns) 24.56 ns 35.31 ns 35.83 ns inline Array.map x 3 26.4 ns/iter (24.76 ns … 113.46 ns) 25.85 ns 50.35 ns 55.89 ns inline Array.map x 4 26.9 ns/iter (25.72 ns … 61.44 ns) 26.7 ns 36.27 ns 36.78 ns inline Array.map x 5 26.71 ns/iter (25.53 ns … 77.83 ns) 26.63 ns 36.52 ns 37.21 ns inline Array.map x 6 28.69 ns/iter (27.15 ns … 61.93 ns) 28.81 ns 38.05 ns 38.55 ns inline Array.map x 7 32.51 ns/iter (30.23 ns … 77.6 ns) 33 ns 44.39 ns 44.99 ns inline Array.map x 8 26.38 ns/iter (25.42 ns … 94.17 ns) 26.2 ns 35.94 ns 36.53 ns inline Array.map x 9 26.95 ns/iter (26.03 ns … 48.96 ns) 26.85 ns 36.67 ns 37.02 ns inline Array.map x 10 29.16 ns/iter (28.09 ns … 54.53 ns) 28.98 ns 38.25 ns 38.58 ns inline Array.map x 11 30.03 ns/iter (29 ns … 52.77 ns) 29.88 ns 38.81 ns 39.3 ns inline Array.map x 12 31.15 ns/iter (30.15 ns … 69.39 ns) 30.95 ns 39.96 ns 40.58 ns inline Array.map x 13 31.98 ns/iter (30.96 ns … 54.88 ns) 31.78 ns 41.58 ns 41.92 ns inline Array.map x 14 33.01 ns/iter (31.87 ns … 49.52 ns) 32.68 ns 42.47 ns 42.64 ns inline Array.map x 15 33.81 ns/iter (32.65 ns … 58.02 ns) 33.47 ns 43.13 ns 43.36 ns inline Array.map x 16 35.03 ns/iter (33.81 ns … 62.9 ns) 34.71 ns 44.63 ns 45.16 ns inline Array.map x 17 35.81 ns/iter (34.46 ns … 118.63 ns) 35.45 ns 45.33 ns 45.87 ns inline Array.map x 18 36.77 ns/iter (35.35 ns … 58.17 ns) 36.57 ns 46.85 ns 47.06 ns inline Array.map x 19 37.95 ns/iter (36.56 ns … 65.8 ns) 37.68 ns 48.07 ns 48.39 ns

Yusuke Suzuki

Comment 4 2022-10-02 00:04:26 PDT

Pull request: https://github.com/WebKit/WebKit/pull/4909

EWS

Comment 5 2022-10-03 18:47:12 PDT

Committed 255105@main (3c9c31d0fd7c): <https://commits.webkit.org/255105@main> Reviewed commits have been landed. Closing PR #4909 and removing active labels.

Attachments
array-map.mjs (1.90 KB, text/plain) 2022-09-28 14:12 PDT, Jarred Sumner	no flags	Details
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Bug 245797