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mirror of https://github.com/golang/go synced 2024-11-22 10:24:41 -07:00
go/api
Russ Cox 8abde68f19 math/rand/v2: delete Mitchell/Reeds source
These slowdowns are because we are now using PCG instead of the
Mitchell/Reeds LFSR for the benchmarks. PCG is in fact a bit slower
(but generates statically far better random numbers).

goos: linux
goarch: amd64
pkg: math/rand/v2
cpu: AMD Ryzen 9 7950X 16-Core Processor
                        │ 01ff938549.amd64 │           afa459a2f0.amd64           │
                        │      sec/op      │    sec/op     vs base                │
PCG_DXSM-32                    1.490n ± 0%    1.488n ± 2%        ~ (p=0.408 n=20)
SourceUint64-32                1.352n ± 1%    1.450n ± 3%   +7.21% (p=0.000 n=20)
GlobalInt64-32                 2.083n ± 0%    2.067n ± 2%        ~ (p=0.223 n=20)
GlobalInt64Parallel-32        0.1035n ± 1%   0.1044n ± 2%        ~ (p=0.010 n=20)
GlobalUint64-32                2.038n ± 1%    2.085n ± 0%   +2.28% (p=0.000 n=20)
GlobalUint64Parallel-32       0.1006n ± 1%   0.1008n ± 1%        ~ (p=0.733 n=20)
Int64-32                       1.687n ± 2%    1.779n ± 1%   +5.48% (p=0.000 n=20)
Uint64-32                      1.674n ± 2%    1.854n ± 2%  +10.69% (p=0.000 n=20)
GlobalIntN1000-32              3.135n ± 1%    3.140n ± 3%        ~ (p=0.794 n=20)
IntN1000-32                    2.478n ± 1%    2.496n ± 1%   +0.73% (p=0.006 n=20)
Int64N1000-32                  2.455n ± 1%    2.510n ± 2%   +2.22% (p=0.000 n=20)
Int64N1e8-32                   2.467n ± 2%    2.471n ± 2%        ~ (p=0.050 n=20)
Int64N1e9-32                   2.454n ± 1%    2.488n ± 2%   +1.39% (p=0.000 n=20)
Int64N2e9-32                   2.482n ± 1%    2.478n ± 2%        ~ (p=0.066 n=20)
Int64N1e18-32                  3.349n ± 2%    3.088n ± 1%   -7.81% (p=0.000 n=20)
Int64N2e18-32                  3.537n ± 1%    3.493n ± 1%   -1.24% (p=0.002 n=20)
Int64N4e18-32                  4.917n ± 0%    5.060n ± 2%   +2.91% (p=0.000 n=20)
Int32N1000-32                  2.386n ± 1%    2.620n ± 1%   +9.76% (p=0.000 n=20)
Int32N1e8-32                   2.366n ± 1%    2.652n ± 0%  +12.11% (p=0.000 n=20)
Int32N1e9-32                   2.355n ± 2%    2.644n ± 1%  +12.32% (p=0.000 n=20)
Int32N2e9-32                   2.371n ± 1%    2.619n ± 2%  +10.48% (p=0.000 n=20)
Float32-32                     2.245n ± 2%    2.261n ± 1%        ~ (p=0.625 n=20)
Float64-32                     2.235n ± 1%    2.241n ± 2%        ~ (p=0.393 n=20)
ExpFloat64-32                  3.813n ± 3%    3.716n ± 1%   -2.53% (p=0.000 n=20)
NormFloat64-32                 3.652n ± 2%    3.718n ± 1%   +1.79% (p=0.006 n=20)
Perm3-32                       33.12n ± 3%    34.11n ± 2%        ~ (p=0.021 n=20)
Perm30-32                      205.1n ± 1%    200.6n ± 0%   -2.17% (p=0.000 n=20)
Perm30ViaShuffle-32            110.8n ± 1%    109.7n ± 1%   -0.99% (p=0.002 n=20)
ShuffleOverhead-32             113.0n ± 1%    107.2n ± 1%   -5.09% (p=0.000 n=20)
Concurrent-32                  2.100n ± 0%    2.108n ± 6%        ~ (p=0.103 n=20)

goos: darwin
goarch: arm64
pkg: math/rand/v2
                       │ 01ff938549.arm64 │           afa459a2f0.arm64           │
                       │      sec/op      │    sec/op     vs base                │
PCG_DXSM-8                    2.531n ± 0%    2.531n ± 0%        ~ (p=0.763 n=20)
SourceUint64-8                2.258n ± 1%    2.531n ± 0%  +12.09% (p=0.000 n=20)
GlobalInt64-8                 2.167n ± 0%    2.177n ± 1%        ~ (p=0.213 n=20)
GlobalInt64Parallel-8        0.4310n ± 0%   0.4319n ± 0%        ~ (p=0.027 n=20)
GlobalUint64-8                2.182n ± 1%    2.185n ± 1%        ~ (p=0.683 n=20)
GlobalUint64Parallel-8       0.4297n ± 0%   0.4295n ± 1%        ~ (p=0.941 n=20)
Int64-8                       2.472n ± 1%    4.104n ± 0%  +66.00% (p=0.000 n=20)
Uint64-8                      2.449n ± 1%    4.080n ± 0%  +66.60% (p=0.000 n=20)
GlobalIntN1000-8              2.814n ± 2%    2.814n ± 1%        ~ (p=0.972 n=20)
IntN1000-8                    2.998n ± 2%    4.140n ± 0%  +38.09% (p=0.000 n=20)
Int64N1000-8                  2.949n ± 2%    4.139n ± 0%  +40.35% (p=0.000 n=20)
Int64N1e8-8                   2.953n ± 2%    4.140n ± 0%  +40.22% (p=0.000 n=20)
Int64N1e9-8                   2.950n ± 0%    4.139n ± 0%  +40.32% (p=0.000 n=20)
Int64N2e9-8                   2.946n ± 2%    4.140n ± 0%  +40.53% (p=0.000 n=20)
Int64N1e18-8                  3.779n ± 1%    5.273n ± 0%  +39.52% (p=0.000 n=20)
Int64N2e18-8                  4.370n ± 1%    6.059n ± 0%  +38.65% (p=0.000 n=20)
Int64N4e18-8                  6.544n ± 1%    8.803n ± 0%  +34.52% (p=0.000 n=20)
Int32N1000-8                  2.950n ± 0%    4.131n ± 0%  +40.06% (p=0.000 n=20)
Int32N1e8-8                   2.950n ± 2%    4.131n ± 0%  +40.03% (p=0.000 n=20)
Int32N1e9-8                   2.951n ± 2%    4.131n ± 0%  +39.99% (p=0.000 n=20)
Int32N2e9-8                   2.950n ± 2%    4.131n ± 0%  +40.03% (p=0.000 n=20)
Float32-8                     3.441n ± 0%    4.110n ± 0%  +19.44% (p=0.000 n=20)
Float64-8                     3.442n ± 0%    4.104n ± 0%  +19.24% (p=0.000 n=20)
ExpFloat64-8                  4.481n ± 0%    5.338n ± 0%  +19.11% (p=0.000 n=20)
NormFloat64-8                 4.725n ± 0%    5.731n ± 0%  +21.28% (p=0.000 n=20)
Perm3-8                       26.55n ± 0%    26.62n ± 0%   +0.28% (p=0.000 n=20)
Perm30-8                      181.9n ± 0%    194.6n ± 2%   +6.98% (p=0.000 n=20)
Perm30ViaShuffle-8            142.9n ± 0%    156.4n ± 0%   +9.45% (p=0.000 n=20)
ShuffleOverhead-8             120.8n ± 2%    125.8n ± 0%   +4.10% (p=0.000 n=20)
Concurrent-8                  2.421n ± 6%    2.654n ± 6%   +9.67% (p=0.002 n=20)

goos: linux
goarch: 386
pkg: math/rand/v2
cpu: AMD Ryzen 9 7950X 16-Core Processor
                        │ 01ff938549.386 │            afa459a2f0.386             │
                        │     sec/op     │    sec/op     vs base                 │
PCG_DXSM-32                  7.613n ± 1%    7.793n ± 2%    +2.38% (p=0.000 n=20)
SourceUint64-32              2.069n ± 0%    7.680n ± 1%  +271.19% (p=0.000 n=20)
GlobalInt64-32               3.456n ± 1%    3.474n ± 3%         ~ (p=0.654 n=20)
GlobalInt64Parallel-32      0.3252n ± 0%   0.3253n ± 0%         ~ (p=0.952 n=20)
GlobalUint64-32              3.573n ± 1%    3.433n ± 2%    -3.92% (p=0.000 n=20)
GlobalUint64Parallel-32     0.3159n ± 0%   0.3156n ± 0%         ~ (p=0.223 n=20)
Int64-32                     2.562n ± 2%    7.707n ± 1%  +200.74% (p=0.000 n=20)
Uint64-32                    2.592n ± 0%    7.714n ± 1%  +197.65% (p=0.000 n=20)
GlobalIntN1000-32            6.266n ± 2%    6.236n ± 1%         ~ (p=0.039 n=20)
IntN1000-32                  4.724n ± 2%   10.410n ± 1%  +120.39% (p=0.000 n=20)
Int64N1000-32                5.490n ± 2%   10.975n ± 2%   +99.89% (p=0.000 n=20)
Int64N1e8-32                 5.513n ± 2%   10.980n ± 1%   +99.15% (p=0.000 n=20)
Int64N1e9-32                 5.476n ± 1%   10.950n ± 0%   +99.96% (p=0.000 n=20)
Int64N2e9-32                 5.501n ± 2%   11.110n ± 1%  +101.96% (p=0.000 n=20)
Int64N1e18-32                9.043n ± 2%   15.180n ± 2%   +67.86% (p=0.000 n=20)
Int64N2e18-32                9.601n ± 2%   15.610n ± 1%   +62.60% (p=0.000 n=20)
Int64N4e18-32                12.00n ± 1%    19.23n ± 2%   +60.14% (p=0.000 n=20)
Int32N1000-32                4.829n ± 2%   10.345n ± 1%  +114.25% (p=0.000 n=20)
Int32N1e8-32                 4.825n ± 2%   10.330n ± 1%  +114.09% (p=0.000 n=20)
Int32N1e9-32                 4.830n ± 2%   10.350n ± 1%  +114.26% (p=0.000 n=20)
Int32N2e9-32                 4.750n ± 2%   10.345n ± 1%  +117.81% (p=0.000 n=20)
Float32-32                   10.89n ± 4%    13.57n ± 1%   +24.61% (p=0.000 n=20)
Float64-32                   19.60n ± 4%    22.95n ± 4%   +17.12% (p=0.000 n=20)
ExpFloat64-32                12.96n ± 3%    15.23n ± 2%   +17.47% (p=0.000 n=20)
NormFloat64-32               7.516n ± 1%   13.780n ± 1%   +83.34% (p=0.000 n=20)
Perm3-32                     36.78n ± 2%    46.62n ± 2%   +26.72% (p=0.000 n=20)
Perm30-32                    238.9n ± 2%    400.7n ± 1%   +67.73% (p=0.000 n=20)
Perm30ViaShuffle-32          189.7n ± 2%    350.5n ± 1%   +84.79% (p=0.000 n=20)
ShuffleOverhead-32           159.8n ± 1%    326.0n ± 2%  +104.01% (p=0.000 n=20)
Concurrent-32                3.286n ± 1%    3.290n ± 0%         ~ (p=0.743 n=20)

On the other hand, compared to the original "update benchmarks" CL,
the cleanups we've made more than compensate for PCG being a bit
slower than LFSR, at least on 64-bit x86. ARM64 (Apple M1) is a bit
slower: perhaps the 64x64→128 multiply is slower there for some reason.
386 is noticeably slower, but it's also a non-SSA backend.

goos: linux
goarch: amd64
pkg: math/rand/v2
cpu: AMD Ryzen 9 7950X 16-Core Processor
                        │ 220860f76f.amd64 │            afa459a2f0.amd64            │
                        │      sec/op      │    sec/op     vs base                  │
SourceUint64-32                1.555n ± 1%    1.450n ± 3%   -6.78% (p=0.000 n=20)
GlobalInt64-32                 2.071n ± 1%    2.067n ± 2%        ~ (p=0.673 n=20)
GlobalInt63Parallel-32        0.1023n ± 1%
GlobalInt64Parallel-32                       0.1044n ± 2%
GlobalUint64-32                5.193n ± 1%    2.085n ± 0%  -59.86% (p=0.000 n=20)
GlobalUint64Parallel-32       0.2341n ± 0%   0.1008n ± 1%  -56.93% (p=0.000 n=20)
Int64-32                       2.056n ± 2%    1.779n ± 1%  -13.47% (p=0.000 n=20)
Uint64-32                      2.077n ± 2%    1.854n ± 2%  -10.74% (p=0.000 n=20)
GlobalIntN1000-32              4.077n ± 2%    3.140n ± 3%  -22.98% (p=0.000 n=20)
IntN1000-32                    3.476n ± 2%    2.496n ± 1%  -28.19% (p=0.000 n=20)
Int64N1000-32                  3.059n ± 1%    2.510n ± 2%  -17.96% (p=0.000 n=20)
Int64N1e8-32                   2.942n ± 1%    2.471n ± 2%  -15.98% (p=0.000 n=20)
Int64N1e9-32                   2.932n ± 1%    2.488n ± 2%  -15.14% (p=0.000 n=20)
Int64N2e9-32                   2.925n ± 1%    2.478n ± 2%  -15.30% (p=0.000 n=20)
Int64N1e18-32                  3.116n ± 1%    3.088n ± 1%        ~ (p=0.013 n=20)
Int64N2e18-32                  4.067n ± 1%    3.493n ± 1%  -14.11% (p=0.000 n=20)
Int64N4e18-32                  4.054n ± 1%    5.060n ± 2%  +24.80% (p=0.000 n=20)
Int32N1000-32                  2.951n ± 1%    2.620n ± 1%  -11.22% (p=0.000 n=20)
Int32N1e8-32                   3.102n ± 1%    2.652n ± 0%  -14.50% (p=0.000 n=20)
Int32N1e9-32                   3.535n ± 1%    2.644n ± 1%  -25.20% (p=0.000 n=20)
Int32N2e9-32                   3.514n ± 1%    2.619n ± 2%  -25.47% (p=0.000 n=20)
Float32-32                     2.760n ± 1%    2.261n ± 1%  -18.06% (p=0.000 n=20)
Float64-32                     2.284n ± 1%    2.241n ± 2%        ~ (p=0.016 n=20)
ExpFloat64-32                  3.757n ± 1%    3.716n ± 1%        ~ (p=0.034 n=20)
NormFloat64-32                 3.837n ± 1%    3.718n ± 1%   -3.09% (p=0.000 n=20)
Perm3-32                       35.23n ± 2%    34.11n ± 2%   -3.19% (p=0.000 n=20)
Perm30-32                      208.8n ± 1%    200.6n ± 0%   -3.93% (p=0.000 n=20)
Perm30ViaShuffle-32            111.7n ± 1%    109.7n ± 1%   -1.84% (p=0.000 n=20)
ShuffleOverhead-32             101.1n ± 1%    107.2n ± 1%   +6.03% (p=0.000 n=20)
Concurrent-32                  2.108n ± 7%    2.108n ± 6%        ~ (p=0.644 n=20)
PCG_DXSM-32                                   1.488n ± 2%

goos: darwin
goarch: arm64
pkg: math/rand/v2
cpu: Apple M1
                       │ 220860f76f.arm64 │            afa459a2f0.arm64            │
                       │      sec/op      │    sec/op     vs base                  │
SourceUint64-8                2.316n ± 1%    2.531n ± 0%   +9.33% (p=0.000 n=20)
GlobalInt64-8                 2.183n ± 1%    2.177n ± 1%        ~ (p=0.533 n=20)
GlobalInt63Parallel-8        0.4331n ± 0%
GlobalInt64Parallel-8                       0.4319n ± 0%
GlobalUint64-8                4.377n ± 2%    2.185n ± 1%  -50.07% (p=0.000 n=20)
GlobalUint64Parallel-8       0.9237n ± 0%   0.4295n ± 1%  -53.50% (p=0.000 n=20)
Int64-8                       2.538n ± 1%    4.104n ± 0%  +61.68% (p=0.000 n=20)
Uint64-8                      2.604n ± 1%    4.080n ± 0%  +56.68% (p=0.000 n=20)
GlobalIntN1000-8              3.857n ± 2%    2.814n ± 1%  -27.04% (p=0.000 n=20)
IntN1000-8                    3.822n ± 2%    4.140n ± 0%   +8.32% (p=0.000 n=20)
Int64N1000-8                  3.318n ± 0%    4.139n ± 0%  +24.74% (p=0.000 n=20)
Int64N1e8-8                   3.349n ± 1%    4.140n ± 0%  +23.64% (p=0.000 n=20)
Int64N1e9-8                   3.317n ± 2%    4.139n ± 0%  +24.80% (p=0.000 n=20)
Int64N2e9-8                   3.317n ± 2%    4.140n ± 0%  +24.81% (p=0.000 n=20)
Int64N1e18-8                  3.542n ± 1%    5.273n ± 0%  +48.85% (p=0.000 n=20)
Int64N2e18-8                  5.087n ± 0%    6.059n ± 0%  +19.12% (p=0.000 n=20)
Int64N4e18-8                  5.084n ± 0%    8.803n ± 0%  +73.16% (p=0.000 n=20)
Int32N1000-8                  3.208n ± 2%    4.131n ± 0%  +28.79% (p=0.000 n=20)
Int32N1e8-8                   3.610n ± 1%    4.131n ± 0%  +14.43% (p=0.000 n=20)
Int32N1e9-8                   4.235n ± 0%    4.131n ± 0%   -2.44% (p=0.000 n=20)
Int32N2e9-8                   4.229n ± 1%    4.131n ± 0%   -2.33% (p=0.000 n=20)
Float32-8                     3.468n ± 0%    4.110n ± 0%  +18.50% (p=0.000 n=20)
Float64-8                     3.447n ± 0%    4.104n ± 0%  +19.05% (p=0.000 n=20)
ExpFloat64-8                  4.567n ± 0%    5.338n ± 0%  +16.86% (p=0.000 n=20)
NormFloat64-8                 4.821n ± 0%    5.731n ± 0%  +18.89% (p=0.000 n=20)
Perm3-8                       28.89n ± 0%    26.62n ± 0%   -7.84% (p=0.000 n=20)
Perm30-8                      175.7n ± 0%    194.6n ± 2%  +10.76% (p=0.000 n=20)
Perm30ViaShuffle-8            153.5n ± 0%    156.4n ± 0%   +1.86% (p=0.000 n=20)
ShuffleOverhead-8             119.8n ± 1%    125.8n ± 0%   +4.97% (p=0.000 n=20)
Concurrent-8                  2.433n ± 3%    2.654n ± 6%   +9.13% (p=0.001 n=20)
PCG_DXSM-8                                   2.531n ± 0%

goos: linux
goarch: 386
pkg: math/rand/v2
cpu: AMD Ryzen 9 7950X 16-Core Processor
                        │ 220860f76f.386 │             afa459a2f0.386              │
                        │     sec/op     │    sec/op     vs base                   │
SourceUint64-32             2.370n ±  1%    7.680n ± 1%  +224.05% (p=0.000 n=20)
GlobalInt64-32              3.569n ±  1%    3.474n ± 3%    -2.66% (p=0.001 n=20)
GlobalInt63Parallel-32     0.3221n ±  1%
GlobalInt64Parallel-32                     0.3253n ± 0%
GlobalUint64-32             8.797n ± 10%    3.433n ± 2%   -60.98% (p=0.000 n=20)
GlobalUint64Parallel-32    0.6351n ±  0%   0.3156n ± 0%   -50.31% (p=0.000 n=20)
Int64-32                    2.612n ±  2%    7.707n ± 1%  +195.04% (p=0.000 n=20)
Uint64-32                   3.350n ±  1%    7.714n ± 1%  +130.25% (p=0.000 n=20)
GlobalIntN1000-32           5.892n ±  1%    6.236n ± 1%    +5.82% (p=0.000 n=20)
IntN1000-32                 4.546n ±  1%   10.410n ± 1%  +128.97% (p=0.000 n=20)
Int64N1000-32               14.59n ±  1%    10.97n ± 2%   -24.75% (p=0.000 n=20)
Int64N1e8-32                14.76n ±  2%    10.98n ± 1%   -25.58% (p=0.000 n=20)
Int64N1e9-32                16.57n ±  1%    10.95n ± 0%   -33.90% (p=0.000 n=20)
Int64N2e9-32                14.54n ±  1%    11.11n ± 1%   -23.62% (p=0.000 n=20)
Int64N1e18-32               16.14n ±  1%    15.18n ± 2%    -5.95% (p=0.000 n=20)
Int64N2e18-32               18.10n ±  1%    15.61n ± 1%   -13.73% (p=0.000 n=20)
Int64N4e18-32               18.65n ±  1%    19.23n ± 2%    +3.08% (p=0.000 n=20)
Int32N1000-32               3.560n ±  1%   10.345n ± 1%  +190.55% (p=0.000 n=20)
Int32N1e8-32                3.770n ±  2%   10.330n ± 1%  +174.01% (p=0.000 n=20)
Int32N1e9-32                4.098n ±  0%   10.350n ± 1%  +152.53% (p=0.000 n=20)
Int32N2e9-32                4.179n ±  1%   10.345n ± 1%  +147.52% (p=0.000 n=20)
Float32-32                  21.18n ±  4%    13.57n ± 1%   -35.93% (p=0.000 n=20)
Float64-32                  20.60n ±  2%    22.95n ± 4%   +11.41% (p=0.000 n=20)
ExpFloat64-32               13.07n ±  0%    15.23n ± 2%   +16.48% (p=0.000 n=20)
NormFloat64-32              7.738n ±  2%   13.780n ± 1%   +78.08% (p=0.000 n=20)
Perm3-32                    36.73n ±  1%    46.62n ± 2%   +26.91% (p=0.000 n=20)
Perm30-32                   211.9n ±  1%    400.7n ± 1%   +89.05% (p=0.000 n=20)
Perm30ViaShuffle-32         165.2n ±  1%    350.5n ± 1%  +112.20% (p=0.000 n=20)
ShuffleOverhead-32          133.9n ±  1%    326.0n ± 2%  +143.37% (p=0.000 n=20)
Concurrent-32               3.287n ±  2%    3.290n ± 0%         ~ (p=0.365 n=20)
PCG_DXSM-32                                 7.793n ± 2%

For #61716.

Change-Id: I4e9c0525b5f84a2ac46f23da9e365495e2d05777
Reviewed-on: https://go-review.googlesource.com/c/go/+/502506
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Russ Cox <rsc@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2023-10-30 17:09:26 +00:00
..
next math/rand/v2: delete Mitchell/Reeds source 2023-10-30 17:09:26 +00:00
except.txt crypto/tls: implement Extended Master Secret 2023-05-25 00:13:30 +00:00
go1.1.txt strconv: quote rune 007F as \x7f, not \u007f 2022-03-31 20:37:15 +00:00
go1.2.txt
go1.3.txt
go1.4.txt
go1.5.txt
go1.6.txt
go1.7.txt
go1.8.txt
go1.9.txt cmd/api: set architecture sizes when type checking 2021-10-04 20:20:20 +00:00
go1.10.txt
go1.11.txt
go1.12.txt
go1.13.txt api/go1.13: add debug/elf.Symbol fields added in CL 184099 2019-08-08 18:44:16 +00:00
go1.14.txt cmd/api: add API checks for freebsd/arm64 2023-02-17 20:31:46 +00:00
go1.15.txt go/printer: remove exported StdFormat flag 2020-07-17 02:15:01 +00:00
go1.16.txt cmd/api: track darwin arm64 port 2022-12-02 16:30:41 +00:00
go1.17.txt cmd/api: add API checks for freebsd/arm64 2023-02-17 20:31:46 +00:00
go1.18.txt cmd/api: add API checks for freebsd/arm64 2023-02-17 20:31:46 +00:00
go1.19.txt cmd/api: track deprecations 2022-12-02 16:29:41 +00:00
go1.20.txt cmd/api: add API checks for freebsd/riscv64 2023-02-17 21:23:32 +00:00
go1.21.txt go/ast: deprecate Object 2023-08-07 09:39:17 +00:00
go1.txt
README cmd/api: require proposal # for new API features 2022-03-14 21:43:16 +00:00

Files in this directory are data for Go's API checker ("go tool api", in src/cmd/api).

Each file is a list of API features, one per line.

go1.txt (and similarly named files) are frozen once a version has been
shipped. Each file adds new lines but does not remove any.

except.txt lists features that may disappear without breaking true
compatibility.

Starting with go1.19.txt, each API feature line must end in "#nnnnn"
giving the GitHub issue number of the proposal issue that accepted
the new API. This helps with our end-of-cycle audit of new APIs.
The same requirement applies to next/* (described below), which will
become a go1.XX.txt for XX >= 19.

The next/ directory contains the only files intended to be mutated.
Each file in that directory contains a list of features that may be added
to the next release of Go. The files in this directory only affect the
warning output from the go api tool. Each file should be named
nnnnn.txt, after the issue number for the accepted proposal.
(The #nnnnn suffix must also appear at the end of each line in the file;
that will be preserved when next/*.txt is concatenated into go1.XX.txt.)