tree cdce2df918426058d931d298368cc1c3fc54475b
parent 5ff0b531748fcdc88d6667e55e021fe02e0c0089
author go101 <tapir.liu@gmail.com> 1700726164 +0000
committer Gopher Robot <gobot@golang.org> 1714138326 +0000

slices: optimize Compact and CompactFunc

Try to save a comparison in the loop bodies of Compact and CompactFunc.

Note: due to #64272, some bound checks still fail to be removed.

                            │ old.txt  │             new.txt              │
                            │   sec/op    │   sec/op     vs base                │
Compact/nil-4                 4.191n ± 9%   3.402n ± 1%  -18.84% (p=0.000 n=10)
Compact/one-4                 5.289n ± 2%   4.553n ± 2%  -13.93% (p=0.000 n=10)
Compact/sorted-4              9.865n ± 0%   6.882n ± 1%  -30.24% (p=0.000 n=10)
Compact/2_items-4             11.10n ± 2%   12.11n ± 2%   +9.00% (p=0.000 n=10)
Compact/unsorted-4            9.831n ± 3%   6.918n ± 2%  -29.62% (p=0.000 n=10)
Compact/many-4                16.40n ± 4%   14.90n ± 1%   -9.20% (p=0.000 n=10)
Compact/dup_start-4           29.87n ± 0%   28.06n ± 3%   -6.04% (p=0.001 n=10)
Compact_Large/all_dup-4       13.11µ ± 0%   13.12µ ± 0%        ~ (p=0.971 n=10)
Compact_Large/no_dup-4        6.972µ ± 0%   5.806µ ± 0%  -16.73% (p=0.000 n=10)
CompactFunc/nil-4             5.300n ± 0%   5.309n ± 1%        ~ (p=0.289 n=10)
CompactFunc/one-4             6.051n ± 1%   6.442n ± 3%   +6.46% (p=0.000 n=10)
CompactFunc/sorted-4          16.24n ± 1%   12.79n ± 2%  -21.24% (p=0.000 n=10)
CompactFunc/2_items-4         17.89n ± 1%   17.75n ± 0%   -0.75% (p=0.000 n=10)
CompactFunc/unsorted-4        16.26n ± 0%   12.83n ± 1%  -21.07% (p=0.000 n=10)
CompactFunc/many-4            30.71n ± 1%   29.07n ± 0%   -5.32% (p=0.000 n=10)
CompactFunc/dup_start-4       78.94n ± 1%   67.19n ± 1%  -14.89% (p=0.000 n=10)
CompactFunc_Large/all_dup-4   3.277m ± 0%   3.692m ± 2%  +12.67% (p=0.000 n=10)
CompactFunc_Large/no_dup-4    4.019m ± 0%   2.826m ± 1%  -29.68% (p=0.000 n=10)
geomean                       109.6n        96.99n       -11.47%

Change-Id: Ia4c78fa62e7e9f4ff6a39d0e0a0a84cecf79b9cb
GitHub-Last-Rev: cea3d93155f9761d5e7b93f9880fa4e1ec7b4b72
GitHub-Pull-Request: golang/go#64273
Reviewed-on: https://go-review.googlesource.com/c/go/+/543661
Reviewed-by: Keith Randall <khr@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Joedian Reid <joedian@google.com>
Auto-Submit: Keith Randall <khr@golang.org>