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strconv: optimize int-to-decimal and use consistently
Integer-to-decimal conversion is hand-written in multiple
places in this package, with different incomplete optimizations
in different copies. This CL establishes a single implementation,
formatBase10, accurately optimized for a variety of systems,
and then uses it consistently.
Removed the fastSmalls const, which has been true since 2017.
Also renamed smallsString to smalls.
benchmark \ host local linux-arm64 s7 linux-amd64 linux-ppc64le linux-s390x linux-arm s7:GOARCH=386 linux-386
vs base vs base vs base vs base vs base vs base vs base vs base vs base
AppendFloat/Decimal ~ ~ ~ ~ ~ ~ +0.99% ~ ~
AppendFloat/Float ~ ~ ~ +2.67% ~ ~ -0.17% ~ ~
AppendFloat/Exp ~ ~ ~ ~ -5.01% -0.88% -0.14% ~ ~
AppendFloat/NegExp ~ ~ ~ +1.80% ~ -1.55% -0.67% ~ ~
AppendFloat/LongExp ~ ~ ~ -1.36% -2.34% ~ +0.41% ~ ~
AppendFloat/Big ~ ~ ~ -3.94% -2.66% -0.61% +1.01% ~ ~
AppendFloat/BinaryExp -5.86% -2.20% -3.27% -17.16% -6.89% ~ -61.81% -33.80% -27.61%
AppendFloat/32Integer ~ ~ ~ ~ ~ ~ +0.74% ~ ~
AppendFloat/32ExactFraction ~ ~ ~ +2.96% ~ ~ +0.09% +1.62% ~
AppendFloat/32Point ~ ~ ~ ~ ~ ~ +1.31% ~ ~
AppendFloat/32Exp ~ ~ ~ ~ -4.05% ~ -0.05% ~ ~
AppendFloat/32NegExp ~ ~ ~ -0.86% -4.97% ~ +0.23% ~ ~
AppendFloat/32Shortest ~ ~ ~ ~ ~ ~ +0.72% ~ ~
AppendFloat/32Fixed8Hard +4.58% +1.94% +2.77% -4.39% ~ +4.39% -9.36% -11.97% -15.71%
AppendFloat/32Fixed9Hard +4.52% +5.41% +4.13% +3.10% -4.84% +14.34% -3.83% -1.84% -6.42%
AppendFloat/64Fixed1 +3.37% +3.45% +1.31% ~ +6.93% +4.79% -2.99% -2.07% -5.51%
AppendFloat/64Fixed2 +3.44% +3.46% +0.80% ~ +6.03% +6.51% -3.07% -2.23% -6.47%
AppendFloat/64Fixed3 +5.27% +3.06% ~ +2.08% ~ +6.20% -2.85% -3.07% -6.21%
AppendFloat/64Fixed4 +7.82% +3.70% +2.25% +2.01% +5.18% +5.68% -2.18% -1.31% -3.55%
AppendFloat/64Fixed12 +3.81% +3.67% ~ +3.91% ~ +5.71% -9.49% -12.13% -11.63%
AppendFloat/64Fixed16 -6.26% -1.42% -3.37% -3.15% -2.03% +1.15% -16.18% -21.43% -20.40%
AppendFloat/64Fixed12Hard ~ +2.34% -1.44% ~ -1.99% +9.96% -10.34% -13.89% -13.23%
AppendFloat/64Fixed17Hard -3.86% -0.96% -3.23% -2.85% -5.54% +9.12% -15.76% -19.37% -18.01%
AppendFloat/64Fixed18Hard ~ ~ -1.34% ~ ~ ~ ~ ~ ~
AppendFloat/Slowpath64 ~ ~ ~ ~ ~ -0.63% +0.94% ~ ~
AppendFloat/SlowpathDenormal64 ~ ~ ~ -0.96% ~ -0.53% +0.65% +1.08% ~
AppendUint -5.10% +2.64% -4.21% -8.75% -1.69% -9.73% -60.54% -18.30% -22.34%
AppendUintVarlen/digits=1 +2.91% +4.79% -7.80% ~ +7.60% ~ -4.13% ~ +3.56%
AppendUintVarlen/digits=2 ~ -0.36% ~ ~ ~ +0.99% -5.45% ~ +2.71%
AppendUintVarlen/digits=3 -3.69% -9.19% -5.28% -11.24% -12.90% -28.62% -42.12% -43.20% -32.72%
AppendUintVarlen/digits=4 -5.18% -14.79% -6.11% -11.44% -17.82% -31.59% -39.66% -40.86% -27.99%
AppendUintVarlen/digits=5 ~ -8.76% -11.18% -15.73% -6.94% -16.84% -37.31% -40.43% -29.18%
AppendUintVarlen/digits=6 -1.48% -8.18% -11.67% -15.29% -5.74% -16.51% -38.73% -39.42% -26.00%
AppendUintVarlen/digits=7 -9.34% -9.38% -14.86% -18.42% -4.30% -12.42% -35.23% -38.90% -26.84%
AppendUintVarlen/digits=8 -10.37% -8.50% -17.32% -17.57% -6.52% -21.17% -35.56% -37.64% -22.88%
AppendUintVarlen/digits=9 -15.94% -10.40% -16.51% -21.68% -8.14% -12.55% -33.50% -36.50% -23.86%
AppendUintVarlen/digits=10 -4.16% +7.58% -6.11% -7.51% -5.73% -7.21% -40.04% -26.20% -25.59%
AppendUintVarlen/digits=11 -9.66% -3.38% -12.55% -14.52% -5.92% -16.85% -46.87% -34.70% -32.89%
AppendUintVarlen/digits=12 -7.75% +3.13% -5.16% -11.19% -5.28% -9.87% -52.39% -33.95% -33.40%
AppendUintVarlen/digits=13 -14.43% -6.62% -12.24% -16.02% -3.26% -18.73% -57.28% -33.80% -31.58%
AppendUintVarlen/digits=14 -8.62% +0.74% -7.87% -13.63% -3.57% -10.55% -62.94% -34.30% -35.06%
AppendUintVarlen/digits=15 -14.52% -6.86% -14.08% -17.37% -4.55% -23.38% -61.99% -33.33% -32.28%
AppendUintVarlen/digits=16 -10.77% -2.06% -7.70% -15.64% -4.43% -13.30% -64.95% -33.08% -32.25%
AppendUintVarlen/digits=17 -14.18% -8.84% -12.96% -18.62% -7.55% -21.40% -66.71% -31.96% -31.40%
AppendUintVarlen/digits=18 -11.04% -3.66% -8.43% -16.19% -5.77% -11.42% -71.09% -31.44% -32.31%
AppendUintVarlen/digits=19 -8.62% +0.33% -9.66% -12.56% -5.37% -11.96% -71.30% -23.09% -31.52%
AppendUintVarlen/digits=20 -9.26% +0.36% -6.55% -12.95% -6.83% -13.41% -74.49% -31.80% -38.76%
host: local
│ 428dc15ab39 │ c6ec0aa13de │
│ sec/op │ sec/op vs base │
AppendFloat/Decimal-4 40.13n ± 2% 40.15n ± 2% ~ (p=0.773 n=40)
AppendFloat/Float-4 56.98n ± 1% 57.27n ± 1% ~ (p=0.394 n=40)
AppendFloat/Exp-4 61.46n ± 1% 61.52n ± 1% ~ (p=0.829 n=40)
AppendFloat/NegExp-4 60.24n ± 1% 59.99n ± 2% ~ (p=0.912 n=40)
AppendFloat/LongExp-4 62.09n ± 2% 62.37n ± 2% ~ (p=0.394 n=40)
AppendFloat/Big-4 67.41n ± 1% 66.99n ± 1% ~ (p=0.292 n=40)
AppendFloat/BinaryExp-4 32.27n ± 2% 30.38n ± 2% -5.86% (p=0.000 n=40)
AppendFloat/32Integer-4 39.68n ± 1% 39.34n ± 1% ~ (p=0.233 n=40)
AppendFloat/32ExactFraction-4 57.95n ± 1% 57.88n ± 2% ~ (p=0.900 n=40)
AppendFloat/32Point-4 56.40n ± 1% 56.58n ± 2% ~ (p=0.196 n=40)
AppendFloat/32Exp-4 63.12n ± 2% 63.39n ± 1% ~ (p=0.082 n=40)
AppendFloat/32NegExp-4 59.64n ± 1% 60.29n ± 1% ~ (p=0.192 n=40)
AppendFloat/32Shortest-4 51.58n ± 1% 51.98n ± 0% ~ (p=0.082 n=40)
AppendFloat/32Fixed8Hard-4 39.91n ± 1% 41.74n ± 1% +4.58% (p=0.000 n=40)
AppendFloat/32Fixed9Hard-4 43.56n ± 1% 45.53n ± 1% +4.52% (p=0.000 n=40)
AppendFloat/64Fixed1-4 34.61n ± 2% 35.77n ± 2% +3.37% (p=0.000 n=40)
AppendFloat/64Fixed2-4 33.91n ± 1% 35.07n ± 1% +3.44% (p=0.000 n=40)
AppendFloat/64Fixed3-4 35.36n ± 1% 37.23n ± 1% +5.27% (p=0.000 n=40)
AppendFloat/64Fixed4-4 33.95n ± 1% 36.60n ± 1% +7.82% (p=0.000 n=40)
AppendFloat/64Fixed12-4 57.03n ± 1% 59.20n ± 2% +3.81% (p=0.000 n=40)
AppendFloat/64Fixed16-4 51.82n ± 1% 48.58n ± 0% -6.26% (p=0.000 n=40)
AppendFloat/64Fixed12Hard-4 48.32n ± 1% 49.00n ± 0% ~ (p=0.118 n=40)
AppendFloat/64Fixed17Hard-4 57.40n ± 2% 55.18n ± 5% -3.86% (p=0.000 n=40)
AppendFloat/64Fixed18Hard-4 3.298µ ± 1% 3.291µ ± 1% ~ (p=0.927 n=40)
AppendFloat/Slowpath64-4 61.94n ± 3% 62.08n ± 3% ~ (p=0.324 n=40)
AppendFloat/SlowpathDenormal64-4 59.94n ± 1% 59.82n ± 1% ~ (p=0.288 n=40)
AppendUint-4 180.6n ± 2% 171.3n ± 2% -5.10% (p=0.000 n=40)
AppendUintVarlen/digits=1-4 4.475n ± 0% 4.605n ± 0% +2.91% (p=0.000 n=40)
AppendUintVarlen/digits=2-4 4.424n ± 1% 4.486n ± 1% ~ (p=0.025 n=40)
AppendUintVarlen/digits=3-4 12.46n ± 4% 12.00n ± 4% -3.69% (p=0.000 n=40)
AppendUintVarlen/digits=4-4 11.68n ± 2% 11.08n ± 2% -5.18% (p=0.000 n=40)
AppendUintVarlen/digits=5-4 11.89n ± 0% 11.82n ± 0% ~ (p=0.001 n=40)
AppendUintVarlen/digits=6-4 12.18n ± 0% 12.00n ± 0% -1.48% (p=0.000 n=40)
AppendUintVarlen/digits=7-4 13.49n ± 2% 12.23n ± 2% -9.34% (p=0.000 n=40)
AppendUintVarlen/digits=8-4 13.21n ± 1% 11.84n ± 2% -10.37% (p=0.000 n=40)
AppendUintVarlen/digits=9-4 15.21n ± 2% 12.79n ± 2% -15.94% (p=0.000 n=40)
AppendUintVarlen/digits=10-4 15.49n ± 3% 14.85n ± 2% -4.16% (p=0.000 n=40)
AppendUintVarlen/digits=11-4 16.82n ± 1% 15.20n ± 1% -9.66% (p=0.000 n=40)
AppendUintVarlen/digits=12-4 17.42n ± 2% 16.07n ± 3% -7.75% (p=0.000 n=40)
AppendUintVarlen/digits=13-4 18.75n ± 2% 16.05n ± 2% -14.43% (p=0.000 n=40)
AppendUintVarlen/digits=14-4 18.90n ± 1% 17.27n ± 2% -8.62% (p=0.000 n=40)
AppendUintVarlen/digits=15-4 20.49n ± 2% 17.52n ± 1% -14.52% (p=0.000 n=40)
AppendUintVarlen/digits=16-4 21.08n ± 1% 18.81n ± 1% -10.77% (p=0.000 n=40)
AppendUintVarlen/digits=17-4 22.64n ± 1% 19.43n ± 1% -14.18% (p=0.000 n=40)
AppendUintVarlen/digits=18-4 22.96n ± 2% 20.42n ± 3% -11.04% (p=0.000 n=40)
AppendUintVarlen/digits=19-4 24.58n ± 0% 22.46n ± 0% -8.62% (p=0.000 n=40)
AppendUintVarlen/digits=20-4 25.23n ± 2% 22.89n ± 0% -9.26% (p=0.000 n=40)
geomean 33.23n 32.17n -3.18%
host: linux-arm64
│ 428dc15ab39 │ c6ec0aa13de │
│ sec/op │ sec/op vs base │
AppendFloat/Decimal-4 61.13n ± 0% ¹ 61.15n ± 0% ¹ ~ (p=0.006 n=40)
AppendFloat/Float-4 88.90n ± 0% ¹ 88.88n ± 0% ¹ ~ (p=0.528 n=40)
AppendFloat/Exp-4 92.87n ± 0% ¹ 92.87n ± 0% ¹ ~ (p=0.795 n=40)
AppendFloat/NegExp-4 93.06n ± 0% ¹ 93.10n ± 0% ¹ ~ (p=0.031 n=40)
AppendFloat/LongExp-4 100.3n ± 0% ¹ 100.3n ± 0% ¹ ~ (p=0.184 n=40)
AppendFloat/Big-4 105.5n ± 0% ¹ 105.6n ± 0% ¹ ~ (p=0.007 n=40)
AppendFloat/BinaryExp-4 47.80n ± 0% ¹ 46.75n ± 0% ¹ -2.20% (p=0.000 n=40)
AppendFloat/32Integer-4 61.24n ± 0% ¹ 61.24n ± 0% ¹ ~ (p=0.809 n=40)
AppendFloat/32ExactFraction-4 85.63n ± 0% ¹ 85.69n ± 0% ¹ ~ (p=0.002 n=40)
AppendFloat/32Point-4 83.23n ± 0% ¹ 83.24n ± 0% ¹ ~ (p=0.410 n=40)
AppendFloat/32Exp-4 92.18n ± 0% ¹ 92.19n ± 0% ¹ ~ (p=0.104 n=40)
AppendFloat/32NegExp-4 87.69n ± 0% ¹ 87.70n ± 0% ¹ ~ (p=0.106 n=40)
AppendFloat/32Shortest-4 77.13n ± 0% ¹ 77.12n ± 0% ¹ ~ (p=0.599 n=40)
AppendFloat/32Fixed8Hard-4 54.55n ± 0% ¹ 55.61n ± 0% ¹ +1.94% (p=0.000 n=40)
AppendFloat/32Fixed9Hard-4 60.91n ± 0% ¹ 64.21n ± 0% ¹ +5.41% (p=0.000 n=40)
AppendFloat/64Fixed1-4 51.37n ± 0% ¹ 53.14n ± 0% ¹ +3.45% (p=0.000 n=40)
AppendFloat/64Fixed2-4 50.34n ± 0% ¹ 52.08n ± 0% ¹ +3.46% (p=0.000 n=40)
AppendFloat/64Fixed3-4 50.91n ± 0% ¹ 52.47n ± 0% ¹ +3.06% (p=0.000 n=40)
AppendFloat/64Fixed4-4 48.59n ± 0% ¹ 50.39n ± 0% ¹ +3.70% (p=0.000 n=40)
AppendFloat/64Fixed12-4 81.00n ± 0% ¹ 83.98n ± 0% ¹ +3.67% (p=0.000 n=40)
AppendFloat/64Fixed16-4 71.60n ± 0% ¹ 70.59n ± 0% ¹ -1.42% (p=0.000 n=40)
AppendFloat/64Fixed12Hard-4 66.07n ± 0% ¹ 67.62n ± 0% ¹ +2.34% (p=0.000 n=40)
AppendFloat/64Fixed17Hard-4 79.00n ± 0% ¹ 78.24n ± 0% ¹ -0.96% (p=0.000 n=40)
AppendFloat/64Fixed18Hard-4 4.290µ ± 0% ¹ 4.291µ ± 0% ¹ ~ (p=0.674 n=40)
AppendFloat/Slowpath64-4 97.87n ± 0% ¹ 97.88n ± 0% ¹ ~ (p=0.847 n=40)
AppendFloat/SlowpathDenormal64-4 95.66n ± 0% ¹ 95.66n ± 0% ¹ ~ (p=0.519 n=40)
AppendUint-4 269.2n ± 0% ¹ 276.3n ± 0% ¹ +2.64% (p=0.000 n=40)
AppendUintVarlen/digits=1-4 6.106n ± 0% ¹ 6.398n ± 0% ¹ +4.79% (p=0.000 n=40)
AppendUintVarlen/digits=2-4 6.082n ± 0% ¹ 6.060n ± 0% ¹ -0.36% (p=0.000 n=40)
AppendUintVarlen/digits=3-4 13.39n ± 0% ¹ 12.16n ± 0% ¹ -9.19% (p=0.000 n=40)
AppendUintVarlen/digits=4-4 15.01n ± 0% ¹ 12.79n ± 0% ¹ -14.79% (p=0.000 n=40)
AppendUintVarlen/digits=5-4 15.92n ± 0% ¹ 14.52n ± 0% ¹ -8.76% (p=0.000 n=40)
AppendUintVarlen/digits=6-4 16.25n ± 0% ¹ 14.92n ± 0% ¹ -8.18% (p=0.000 n=40)
AppendUintVarlen/digits=7-4 18.71n ± 0% ¹ 16.96n ± 0% ¹ -9.38% (p=0.000 n=40)
AppendUintVarlen/digits=8-4 18.94n ± 0% ¹ 17.33n ± 0% ¹ -8.50% (p=0.000 n=40)
AppendUintVarlen/digits=9-4 21.73n ± 0% ¹ 19.47n ± 0% ¹ -10.40% (p=0.000 n=40)
AppendUintVarlen/digits=10-4 22.02n ± 0% ¹ 23.69n ± 0% ¹ +7.58% (p=0.000 n=40)
AppendUintVarlen/digits=11-4 24.85n ± 0% ¹ 24.01n ± 0% ¹ -3.38% (p=0.000 n=40)
AppendUintVarlen/digits=12-4 25.21n ± 0% ¹ 26.00n ± 0% ¹ +3.13% (p=0.000 n=40)
AppendUintVarlen/digits=13-4 28.01n ± 0% ¹ 26.15n ± 0% ¹ -6.62% (p=0.000 n=40)
AppendUintVarlen/digits=14-4 28.36n ± 0% ¹ 28.57n ± 0% ¹ +0.74% (p=0.000 n=40)
AppendUintVarlen/digits=15-4 31.20n ± 0% ¹ 29.06n ± 0% ¹ -6.86% (p=0.000 n=40)
AppendUintVarlen/digits=16-4 31.55n ± 0% ¹ 30.90n ± 0% ¹ -2.06% (p=0.000 n=40)
AppendUintVarlen/digits=17-4 35.05n ± 0% ¹ 31.95n ± 0% ¹ -8.84% (p=0.000 n=40)
AppendUintVarlen/digits=18-4 35.50n ± 0% ¹ 34.20n ± 0% ¹ -3.66% (p=0.000 n=40)
AppendUintVarlen/digits=19-4 38.22n ± 0% ¹ 38.34n ± 0% ¹ +0.33% (p=0.000 n=40)
AppendUintVarlen/digits=20-4 38.68n ± 0% ¹ 38.82n ± 0% ¹ +0.36% (p=0.000 n=40)
geomean 48.25n 47.59n -1.36%
¹ benchmarks vary in cpu
host: s7
│ 428dc15ab39 │ c6ec0aa13de │
│ sec/op │ sec/op vs base │
AppendFloat/Decimal-4 23.81n ± 1% 23.76n ± 1% ~ (p=0.885 n=40)
AppendFloat/Float-4 36.85n ± 1% 36.97n ± 1% ~ (p=0.002 n=40)
AppendFloat/Exp-4 36.82n ± 1% 36.59n ± 1% ~ (p=0.292 n=40)
AppendFloat/NegExp-4 37.44n ± 1% 37.41n ± 1% ~ (p=0.596 n=40)
AppendFloat/LongExp-4 39.82n ± 1% 39.78n ± 1% ~ (p=0.025 n=40)
AppendFloat/Big-4 41.94n ± 1% 41.81n ± 1% ~ (p=0.054 n=40)
AppendFloat/BinaryExp-4 20.18n ± 1% 19.52n ± 0% -3.27% (p=0.000 n=40)
AppendFloat/32Integer-4 23.88n ± 0% 23.92n ± 0% ~ (p=0.408 n=40)
AppendFloat/32ExactFraction-4 36.45n ± 1% 36.26n ± 0% ~ (p=0.088 n=40)
AppendFloat/32Point-4 35.23n ± 1% 35.33n ± 1% ~ (p=0.470 n=40)
AppendFloat/32Exp-4 38.04n ± 1% 37.89n ± 1% ~ (p=0.885 n=40)
AppendFloat/32NegExp-4 36.20n ± 0% 36.21n ± 1% ~ (p=0.923 n=40)
AppendFloat/32Shortest-4 32.55n ± 0% 32.42n ± 1% ~ (p=0.238 n=40)
AppendFloat/32Fixed8Hard-4 24.70n ± 0% 25.38n ± 1% +2.77% (p=0.000 n=40)
AppendFloat/32Fixed9Hard-4 27.13n ± 0% 28.25n ± 1% +4.13% (p=0.000 n=40)
AppendFloat/64Fixed1-4 21.40n ± 0% 21.68n ± 1% +1.31% (p=0.000 n=40)
AppendFloat/64Fixed2-4 21.17n ± 0% 21.33n ± 1% +0.80% (p=0.001 n=40)
AppendFloat/64Fixed3-4 22.09n ± 1% 22.29n ± 1% ~ (p=0.003 n=40)
AppendFloat/64Fixed4-4 21.38n ± 1% 21.86n ± 1% +2.25% (p=0.000 n=40)
AppendFloat/64Fixed12-4 35.17n ± 0% 35.28n ± 1% ~ (p=0.125 n=40)
AppendFloat/64Fixed16-4 32.02n ± 1% 30.94n ± 1% -3.37% (p=0.000 n=40)
AppendFloat/64Fixed12Hard-4 29.79n ± 1% 29.36n ± 0% -1.44% (p=0.000 n=40)
AppendFloat/64Fixed17Hard-4 34.79n ± 1% 33.66n ± 0% -3.23% (p=0.000 n=40)
AppendFloat/64Fixed18Hard-4 1.983µ ± 1% 1.956µ ± 1% -1.34% (p=0.000 n=40)
AppendFloat/Slowpath64-4 38.15n ± 0% 37.84n ± 1% ~ (p=0.039 n=40)
AppendFloat/SlowpathDenormal64-4 38.06n ± 1% 38.24n ± 1% ~ (p=0.025 n=40)
AppendUint-4 121.0n ± 0% 115.9n ± 1% -4.21% (p=0.000 n=40)
AppendUintVarlen/digits=1-4 2.557n ± 1% 2.358n ± 4% -7.80% (p=0.000 n=40)
AppendUintVarlen/digits=2-4 2.387n ± 4% 2.405n ± 4% ~ (p=0.149 n=40)
AppendUintVarlen/digits=3-4 6.198n ± 1% 5.871n ± 1% -5.28% (p=0.000 n=40)
AppendUintVarlen/digits=4-4 6.196n ± 0% 5.817n ± 1% -6.11% (p=0.000 n=40)
AppendUintVarlen/digits=5-4 6.773n ± 1% 6.016n ± 1% -11.18% (p=0.000 n=40)
AppendUintVarlen/digits=6-4 6.948n ± 1% 6.136n ± 1% -11.67% (p=0.000 n=40)
AppendUintVarlen/digits=7-4 8.157n ± 1% 6.944n ± 1% -14.86% (p=0.000 n=40)
AppendUintVarlen/digits=8-4 8.364n ± 1% 6.915n ± 0% -17.32% (p=0.000 n=40)
AppendUintVarlen/digits=9-4 9.740n ± 1% 8.132n ± 1% -16.51% (p=0.000 n=40)
AppendUintVarlen/digits=10-4 9.836n ± 1% 9.235n ± 1% -6.11% (p=0.000 n=40)
AppendUintVarlen/digits=11-4 11.000n ± 1% 9.620n ± 0% -12.55% (p=0.000 n=40)
AppendUintVarlen/digits=12-4 11.14n ± 1% 10.57n ± 1% -5.16% (p=0.000 n=40)
AppendUintVarlen/digits=13-4 12.30n ± 1% 10.79n ± 1% -12.24% (p=0.000 n=40)
AppendUintVarlen/digits=14-4 12.44n ± 1% 11.46n ± 0% -7.87% (p=0.000 n=40)
AppendUintVarlen/digits=15-4 13.71n ± 1% 11.78n ± 1% -14.08% (p=0.000 n=40)
AppendUintVarlen/digits=16-4 13.82n ± 1% 12.76n ± 1% -7.70% (p=0.000 n=40)
AppendUintVarlen/digits=17-4 14.97n ± 1% 13.03n ± 0% -12.96% (p=0.000 n=40)
AppendUintVarlen/digits=18-4 15.36n ± 1% 14.06n ± 1% -8.43% (p=0.000 n=40)
AppendUintVarlen/digits=19-4 16.40n ± 1% 14.81n ± 1% -9.66% (p=0.000 n=40)
AppendUintVarlen/digits=20-4 16.48n ± 0% 15.40n ± 1% -6.55% (p=0.000 n=40)
geomean 20.56n 19.65n -4.42%
host: linux-amd64
│ 428dc15ab39 │ c6ec0aa13de │
│ sec/op │ sec/op vs base │
AppendFloat/Decimal-4 64.49n ± 0% 64.79n ± 2% ~ (p=0.169 n=40)
AppendFloat/Float-4 95.98n ± 4% 98.54n ± 4% +2.67% (p=0.000 n=40)
AppendFloat/Exp-4 97.10n ± 1% 97.99n ± 4% ~ (p=0.002 n=40)
AppendFloat/NegExp-4 98.10n ± 0% 99.87n ± 4% +1.80% (p=0.000 n=40)
AppendFloat/LongExp-4 106.7n ± 4% 105.3n ± 4% -1.36% (p=0.001 n=40)
AppendFloat/Big-4 116.8n ± 3% 112.3n ± 4% -3.94% (p=0.001 n=40)
AppendFloat/BinaryExp-4 57.70n ± 3% 47.79n ± 3% -17.16% (p=0.000 n=40)
AppendFloat/32Integer-4 64.75n ± 3% 64.71n ± 3% ~ (p=0.700 n=40)
AppendFloat/32ExactFraction-4 91.48n ± 2% 94.19n ± 3% +2.96% (p=0.000 n=40)
AppendFloat/32Point-4 92.48n ± 2% 92.73n ± 4% ~ (p=0.389 n=40)
AppendFloat/32Exp-4 103.6n ± 2% 103.4n ± 1% ~ (p=0.069 n=40)
AppendFloat/32NegExp-4 95.16n ± 1% 94.33n ± 0% -0.86% (p=0.001 n=40)
AppendFloat/32Shortest-4 85.43n ± 4% 84.89n ± 1% ~ (p=0.082 n=40)
AppendFloat/32Fixed8Hard-4 64.42n ± 3% 61.59n ± 0% -4.39% (p=0.000 n=40)
AppendFloat/32Fixed9Hard-4 69.74n ± 3% 71.91n ± 4% +3.10% (p=0.000 n=40)
AppendFloat/64Fixed1-4 59.70n ± 3% 59.16n ± 4% ~ (p=0.051 n=40)
AppendFloat/64Fixed2-4 58.73n ± 2% 58.03n ± 0% ~ (p=0.110 n=40)
AppendFloat/64Fixed3-4 57.92n ± 4% 59.13n ± 4% +2.08% (p=0.000 n=40)
AppendFloat/64Fixed4-4 55.21n ± 3% 56.33n ± 4% +2.01% (p=0.000 n=40)
AppendFloat/64Fixed12-4 87.98n ± 3% 91.42n ± 1% +3.91% (p=0.000 n=40)
AppendFloat/64Fixed16-4 80.05n ± 3% 77.52n ± 4% -3.15% (p=0.000 n=40)
AppendFloat/64Fixed12Hard-4 75.03n ± 4% 74.99n ± 0% ~ (p=0.641 n=40)
AppendFloat/64Fixed17Hard-4 87.45n ± 1% 84.96n ± 2% -2.85% (p=0.000 n=40)
AppendFloat/64Fixed18Hard-4 4.903µ ± 3% 4.912µ ± 3% ~ (p=0.829 n=40)
AppendFloat/Slowpath64-4 101.8n ± 1% 101.4n ± 4% ~ (p=0.268 n=40)
AppendFloat/SlowpathDenormal64-4 101.0n ± 4% 100.1n ± 3% -0.96% (p=0.000 n=40)
AppendUint-4 336.7n ± 1% 307.2n ± 0% -8.75% (p=0.000 n=40)
AppendUintVarlen/digits=1-4 6.069n ± 1% 6.069n ± 1% ~ (p=0.904 n=40)
AppendUintVarlen/digits=2-4 5.920n ± 3% 5.925n ± 3% ~ (p=0.010 n=40)
AppendUintVarlen/digits=3-4 16.33n ± 1% 14.49n ± 2% -11.24% (p=0.000 n=40)
AppendUintVarlen/digits=4-4 16.70n ± 2% 14.79n ± 2% -11.44% (p=0.000 n=40)
AppendUintVarlen/digits=5-4 19.33n ± 1% 16.29n ± 1% -15.73% (p=0.000 n=40)
AppendUintVarlen/digits=6-4 20.15n ± 2% 17.07n ± 1% -15.29% (p=0.000 n=40)
AppendUintVarlen/digits=7-4 22.78n ± 2% 18.58n ± 1% -18.42% (p=0.000 n=40)
AppendUintVarlen/digits=8-4 23.56n ± 3% 19.43n ± 2% -17.57% (p=0.000 n=40)
AppendUintVarlen/digits=9-4 27.12n ± 3% 21.24n ± 3% -21.68% (p=0.000 n=40)
AppendUintVarlen/digits=10-4 27.10n ± 2% 25.07n ± 3% -7.51% (p=0.000 n=40)
AppendUintVarlen/digits=11-4 29.72n ± 3% 25.41n ± 3% -14.52% (p=0.000 n=40)
AppendUintVarlen/digits=12-4 30.35n ± 3% 26.95n ± 4% -11.19% (p=0.000 n=40)
AppendUintVarlen/digits=13-4 32.98n ± 0% 27.70n ± 3% -16.02% (p=0.000 n=40)
AppendUintVarlen/digits=14-4 33.89n ± 2% 29.28n ± 3% -13.63% (p=0.000 n=40)
AppendUintVarlen/digits=15-4 36.45n ± 3% 30.11n ± 1% -17.37% (p=0.000 n=40)
AppendUintVarlen/digits=16-4 37.12n ± 0% 31.31n ± 1% -15.64% (p=0.000 n=40)
AppendUintVarlen/digits=17-4 39.84n ± 1% 32.42n ± 0% -18.62% (p=0.000 n=40)
AppendUintVarlen/digits=18-4 40.53n ± 0% 33.97n ± 3% -16.19% (p=0.000 n=40)
AppendUintVarlen/digits=19-4 43.20n ± 4% 37.78n ± 0% -12.56% (p=0.000 n=40)
AppendUintVarlen/digits=20-4 43.87n ± 1% 38.19n ± 0% -12.95% (p=0.000 n=40)
geomean 54.70n 51.10n -6.58%
host: linux-ppc64le
│ 428dc15ab39 │ c6ec0aa13de │
│ sec/op │ sec/op vs base │
AppendFloat/Decimal-4 55.69n ± 3% 56.06n ± 3% ~ (p=0.821 n=40)
AppendFloat/Float-4 79.23n ± 1% 77.13n ± 3% ~ (p=0.019 n=40)
AppendFloat/Exp-4 91.14n ± 2% 86.58n ± 2% -5.01% (p=0.000 n=40)
AppendFloat/NegExp-4 90.77n ± 1% 85.43n ± 6% ~ (p=0.003 n=40)
AppendFloat/LongExp-4 93.40n ± 2% 91.21n ± 2% -2.34% (p=0.000 n=40)
AppendFloat/Big-4 101.55n ± 3% 98.84n ± 2% -2.66% (p=0.000 n=40)
AppendFloat/BinaryExp-4 45.16n ± 3% 42.05n ± 2% -6.89% (p=0.000 n=40)
AppendFloat/32Integer-4 56.50n ± 3% 57.45n ± 2% ~ (p=0.821 n=40)
AppendFloat/32ExactFraction-4 80.94n ± 2% 80.60n ± 1% ~ (p=0.106 n=40)
AppendFloat/32Point-4 77.03n ± 3% 76.69n ± 2% ~ (p=0.242 n=40)
AppendFloat/32Exp-4 92.44n ± 1% 88.70n ± 1% -4.05% (p=0.000 n=40)
AppendFloat/32NegExp-4 89.50n ± 2% 85.06n ± 2% -4.97% (p=0.000 n=40)
AppendFloat/32Shortest-4 74.63n ± 2% 72.75n ± 4% ~ (p=0.042 n=40)
AppendFloat/32Fixed8Hard-4 58.18n ± 2% 56.86n ± 1% ~ (p=0.002 n=40)
AppendFloat/32Fixed9Hard-4 64.17n ± 1% 61.06n ± 1% -4.84% (p=0.000 n=40)
AppendFloat/64Fixed1-4 47.56n ± 2% 50.86n ± 1% +6.93% (p=0.000 n=40)
AppendFloat/64Fixed2-4 47.87n ± 4% 50.75n ± 2% +6.03% (p=0.000 n=40)
AppendFloat/64Fixed3-4 50.84n ± 2% 51.68n ± 1% ~ (p=0.014 n=40)
AppendFloat/64Fixed4-4 46.29n ± 3% 48.69n ± 4% +5.18% (p=0.000 n=40)
AppendFloat/64Fixed12-4 79.97n ± 1% 85.03n ± 4% ~ (p=0.001 n=40)
AppendFloat/64Fixed16-4 73.18n ± 1% 71.70n ± 2% -2.03% (p=0.000 n=40)
AppendFloat/64Fixed12Hard-4 68.41n ± 4% 67.06n ± 1% -1.99% (p=0.000 n=40)
AppendFloat/64Fixed17Hard-4 81.02n ± 1% 76.54n ± 1% -5.54% (p=0.000 n=40)
AppendFloat/64Fixed18Hard-4 5.184µ ± 0% 5.215µ ± 1% ~ (p=0.056 n=40)
AppendFloat/Slowpath64-4 89.16n ± 2% 88.85n ± 2% ~ (p=0.405 n=40)
AppendFloat/SlowpathDenormal64-4 84.27n ± 3% 84.38n ± 1% ~ (p=0.424 n=40)
AppendUint-4 277.5n ± 1% 272.9n ± 1% -1.69% (p=0.000 n=40)
AppendUintVarlen/digits=1-4 5.044n ± 3% 5.428n ± 1% +7.60% (p=0.000 n=40)
AppendUintVarlen/digits=2-4 5.051n ± 1% 5.038n ± 2% ~ (p=0.613 n=40)
AppendUintVarlen/digits=3-4 12.13n ± 4% 10.57n ± 2% -12.90% (p=0.000 n=40)
AppendUintVarlen/digits=4-4 13.33n ± 3% 10.95n ± 1% -17.82% (p=0.000 n=40)
AppendUintVarlen/digits=5-4 14.05n ± 2% 13.08n ± 3% -6.94% (p=0.000 n=40)
AppendUintVarlen/digits=6-4 14.46n ± 2% 13.63n ± 2% -5.74% (p=0.000 n=40)
AppendUintVarlen/digits=7-4 17.11n ± 4% 16.38n ± 1% -4.30% (p=0.000 n=40)
AppendUintVarlen/digits=8-4 17.34n ± 5% 16.20n ± 1% -6.52% (p=0.000 n=40)
AppendUintVarlen/digits=9-4 21.06n ± 2% 19.34n ± 2% -8.14% (p=0.000 n=40)
AppendUintVarlen/digits=10-4 21.11n ± 2% 19.90n ± 1% -5.73% (p=0.000 n=40)
AppendUintVarlen/digits=11-4 24.25n ± 4% 22.81n ± 1% -5.92% (p=0.000 n=40)
AppendUintVarlen/digits=12-4 24.53n ± 3% 23.23n ± 2% -5.28% (p=0.000 n=40)
AppendUintVarlen/digits=13-4 27.14n ± 5% 26.26n ± 1% -3.26% (p=0.000 n=40)
AppendUintVarlen/digits=14-4 27.72n ± 6% 26.73n ± 0% -3.57% (p=0.000 n=40)
AppendUintVarlen/digits=15-4 31.23n ± 3% 29.80n ± 1% -4.55% (p=0.000 n=40)
AppendUintVarlen/digits=16-4 30.78n ± 3% 29.41n ± 1% -4.43% (p=0.000 n=40)
AppendUintVarlen/digits=17-4 35.04n ± 1% 32.39n ± 0% -7.55% (p=0.000 n=40)
AppendUintVarlen/digits=18-4 35.10n ± 7% 33.08n ± 0% -5.77% (p=0.000 n=40)
AppendUintVarlen/digits=19-4 38.26n ± 6% 36.21n ± 0% -5.37% (p=0.000 n=40)
AppendUintVarlen/digits=20-4 39.24n ± 3% 36.56n ± 0% -6.83% (p=0.000 n=40)
geomean 46.39n 44.95n -3.11%
host: linux-s390x
│ 428dc15ab39 │ c6ec0aa13de │
│ sec/op │ sec/op vs base │
AppendFloat/Decimal-4 70.92n ± 0% ¹ 70.81n ± 1% ¹ ~ (p=0.668 n=40)
AppendFloat/Float-4 111.5n ± 0% ¹ 111.8n ± 0% ¹ ~ (p=0.143 n=40)
AppendFloat/Exp-4 119.1n ± 1% ¹ 118.1n ± 1% ¹ -0.88% (p=0.000 n=40)
AppendFloat/NegExp-4 119.7n ± 0% ¹ 117.8n ± 0% ¹ -1.55% (p=0.000 n=40)
AppendFloat/LongExp-4 128.1n ± 0% ¹ 127.8n ± 1% ¹ ~ (p=0.181 n=40)
AppendFloat/Big-4 131.3n ± 1% ¹ 130.5n ± 1% ¹ -0.61% (p=0.001 n=40)
AppendFloat/BinaryExp-4 58.47n ± 0% ¹ 58.29n ± 0% ¹ ~ (p=0.189 n=40)
AppendFloat/32Integer-4 72.66n ± 0% ¹ 72.31n ± 1% ¹ ~ (p=0.012 n=40)
AppendFloat/32ExactFraction-4 108.6n ± 0% ¹ 108.5n ± 1% ¹ ~ (p=0.754 n=40)
AppendFloat/32Point-4 108.6n ± 1% ¹ 108.2n ± 0% ¹ ~ (p=0.073 n=40)
AppendFloat/32Exp-4 116.9n ± 1% ¹ 117.8n ± 0% ¹ ~ (p=0.008 n=40)
AppendFloat/32NegExp-4 117.9n ± 0% ¹ 118.0n ± 0% ¹ ~ (p=0.954 n=40)
AppendFloat/32Shortest-4 107.7n ± 1% ¹ 107.0n ± 1% ¹ ~ (p=0.106 n=40)
AppendFloat/32Fixed8Hard-4 71.77n ± 1% ¹ 74.92n ± 1% ¹ +4.39% (p=0.000 n=40)
AppendFloat/32Fixed9Hard-4 73.49n ± 0% ¹ 84.03n ± 0% ¹ +14.34% (p=0.000 n=40)
AppendFloat/64Fixed1-4 63.55n ± 1% ¹ 66.59n ± 1% ¹ +4.79% (p=0.000 n=40)
AppendFloat/64Fixed2-4 61.74n ± 1% ¹ 65.77n ± 1% ¹ +6.51% (p=0.000 n=40)
AppendFloat/64Fixed3-4 63.84n ± 2% ¹ 67.80n ± 1% ¹ +6.20% (p=0.000 n=40)
AppendFloat/64Fixed4-4 60.41n ± 1% ¹ 63.84n ± 1% ¹ +5.68% (p=0.000 n=40)
AppendFloat/64Fixed12-4 98.06n ± 0% ¹ 103.65n ± 0% ¹ +5.71% (p=0.000 n=40)
AppendFloat/64Fixed16-4 86.71n ± 0% ¹ 87.70n ± 0% ¹ +1.15% (p=0.000 n=40)
AppendFloat/64Fixed12Hard-4 80.62n ± 1% ¹ 88.65n ± 1% ¹ +9.96% (p=0.000 n=40)
AppendFloat/64Fixed17Hard-4 89.77n ± 1% ¹ 97.96n ± 1% ¹ +9.12% (p=0.000 n=40)
AppendFloat/64Fixed18Hard-4 4.791µ ± 0% ¹ 4.790µ ± 0% ¹ ~ (p=0.973 n=40)
AppendFloat/Slowpath64-4 126.0n ± 0% ¹ 125.2n ± 0% ¹ -0.63% (p=0.000 n=40)
AppendFloat/SlowpathDenormal64-4 121.7n ± 0% ¹ 121.1n ± 0% ¹ -0.53% (p=0.001 n=40)
AppendUint-4 374.6n ± 1% ¹ 338.2n ± 0% ¹ -9.73% (p=0.000 n=40)
AppendUintVarlen/digits=1-4 5.433n ± 0% ¹ 5.416n ± 0% ¹ ~ (p=0.032 n=40)
AppendUintVarlen/digits=2-4 5.357n ± 0% ¹ 5.410n ± 0% ¹ +0.99% (p=0.000 n=40)
AppendUintVarlen/digits=3-4 17.45n ± 0% ¹ 12.46n ± 0% ¹ -28.62% (p=0.000 n=40)
AppendUintVarlen/digits=4-4 17.38n ± 0% ¹ 11.89n ± 0% ¹ -31.59% (p=0.000 n=40)
AppendUintVarlen/digits=5-4 21.38n ± 0% ¹ 17.78n ± 1% ¹ -16.84% (p=0.000 n=40)
AppendUintVarlen/digits=6-4 21.60n ± 0% ¹ 18.03n ± 1% ¹ -16.51% (p=0.000 n=40)
AppendUintVarlen/digits=7-4 26.44n ± 0% ¹ 23.15n ± 0% ¹ -12.42% (p=0.000 n=40)
AppendUintVarlen/digits=8-4 26.60n ± 0% ¹ 20.97n ± 1% ¹ -21.17% (p=0.000 n=40)
AppendUintVarlen/digits=9-4 31.44n ± 0% ¹ 27.49n ± 0% ¹ -12.55% (p=0.000 n=40)
AppendUintVarlen/digits=10-4 31.26n ± 1% ¹ 29.00n ± 0% ¹ -7.21% (p=0.000 n=40)
AppendUintVarlen/digits=11-4 35.90n ± 0% ¹ 29.84n ± 0% ¹ -16.85% (p=0.000 n=40)
AppendUintVarlen/digits=12-4 35.95n ± 0% ¹ 32.40n ± 0% ¹ -9.87% (p=0.000 n=40)
AppendUintVarlen/digits=13-4 40.98n ± 0% ¹ 33.31n ± 0% ¹ -18.73% (p=0.000 n=40)
AppendUintVarlen/digits=14-4 38.96n ± 0% ¹ 34.85n ± 0% ¹ -10.55% (p=0.000 n=40)
AppendUintVarlen/digits=15-4 45.51n ± 0% ¹ 34.87n ± 0% ¹ -23.38% (p=0.000 n=40)
AppendUintVarlen/digits=16-4 45.05n ± 0% ¹ 39.05n ± 0% ¹ -13.30% (p=0.000 n=40)
AppendUintVarlen/digits=17-4 50.76n ± 0% ¹ 39.89n ± 0% ¹ -21.40% (p=0.000 n=40)
AppendUintVarlen/digits=18-4 49.86n ± 1% ¹ 44.16n ± 0% ¹ -11.42% (p=0.000 n=40)
AppendUintVarlen/digits=19-4 54.68n ± 0% ¹ 48.14n ± 0% ¹ -11.96% (p=0.000 n=40)
AppendUintVarlen/digits=20-4 55.48n ± 0% ¹ 48.04n ± 0% ¹ -13.41% (p=0.000 n=40)
geomean 62.00n 58.40n -5.80%
¹ benchmarks vary in cpu
host: linux-arm
│ 428dc15ab39 │ c6ec0aa13de │
│ sec/op │ sec/op vs base │
AppendFloat/Decimal-4 121.6n ± 0% 122.8n ± 0% +0.99% (p=0.000 n=40)
AppendFloat/Float-4 209.1n ± 0% 208.8n ± 0% -0.17% (p=0.000 n=40)
AppendFloat/Exp-4 208.8n ± 0% 208.5n ± 0% -0.14% (p=0.000 n=40)
AppendFloat/NegExp-4 210.1n ± 0% 208.7n ± 0% -0.67% (p=0.000 n=40)
AppendFloat/LongExp-4 217.5n ± 0% 218.4n ± 0% +0.41% (p=0.000 n=40)
AppendFloat/Big-4 237.8n ± 0% 240.2n ± 0% +1.01% (p=0.000 n=40)
AppendFloat/BinaryExp-4 226.90n ± 0% 86.66n ± 0% -61.81% (p=0.000 n=40)
AppendFloat/32Integer-4 121.9n ± 0% 122.8n ± 0% +0.74% (p=0.000 n=40)
AppendFloat/32ExactFraction-4 174.0n ± 0% 174.1n ± 0% +0.09% (p=0.000 n=40)
AppendFloat/32Point-4 171.9n ± 0% 174.2n ± 0% +1.31% (p=0.000 n=40)
AppendFloat/32Exp-4 195.4n ± 0% 195.3n ± 0% -0.05% (p=0.000 n=40)
AppendFloat/32NegExp-4 174.0n ± 0% 174.4n ± 0% +0.23% (p=0.000 n=40)
AppendFloat/32Shortest-4 167.5n ± 0% 168.7n ± 0% +0.72% (p=0.000 n=40)
AppendFloat/32Fixed8Hard-4 115.4n ± 0% 104.6n ± 0% -9.36% (p=0.000 n=40)
AppendFloat/32Fixed9Hard-4 144.9n ± 0% 139.3n ± 0% -3.83% (p=0.000 n=40)
AppendFloat/64Fixed1-4 127.3n ± 0% 123.5n ± 0% -2.99% (p=0.000 n=40)
AppendFloat/64Fixed2-4 123.6n ± 0% 119.8n ± 0% -3.07% (p=0.000 n=40)
AppendFloat/64Fixed3-4 122.8n ± 0% 119.3n ± 0% -2.85% (p=0.000 n=40)
AppendFloat/64Fixed4-4 114.5n ± 0% 112.0n ± 0% -2.18% (p=0.000 n=40)
AppendFloat/64Fixed12-4 161.3n ± 0% 146.0n ± 0% -9.49% (p=0.000 n=40)
AppendFloat/64Fixed16-4 168.7n ± 0% 141.4n ± 0% -16.18% (p=0.000 n=40)
AppendFloat/64Fixed12Hard-4 152.3n ± 0% 136.6n ± 0% -10.34% (p=0.000 n=40)
AppendFloat/64Fixed17Hard-4 182.7n ± 0% 153.9n ± 0% -15.76% (p=0.000 n=40)
AppendFloat/64Fixed18Hard-4 7.976µ ± 0% 7.977µ ± 0% ~ (p=0.093 n=40)
AppendFloat/Slowpath64-4 213.4n ± 0% 215.4n ± 0% +0.94% (p=0.000 n=40)
AppendFloat/SlowpathDenormal64-4 214.0n ± 0% 215.4n ± 0% +0.65% (p=0.000 n=40)
AppendUint-4 1526.0n ± 0% 602.1n ± 0% -60.54% (p=0.000 n=40)
AppendUintVarlen/digits=1-4 9.338n ± 0% 8.953n ± 0% -4.13% (p=0.000 n=40)
AppendUintVarlen/digits=2-4 9.789n ± 0% 9.256n ± 0% -5.45% (p=0.000 n=40)
AppendUintVarlen/digits=3-4 46.42n ± 0% 26.87n ± 0% -42.12% (p=0.000 n=40)
AppendUintVarlen/digits=4-4 49.23n ± 0% 29.70n ± 0% -39.66% (p=0.000 n=40)
AppendUintVarlen/digits=5-4 51.45n ± 0% 32.25n ± 0% -37.31% (p=0.000 n=40)
AppendUintVarlen/digits=6-4 51.02n ± 0% 31.26n ± 0% -38.73% (p=0.000 n=40)
AppendUintVarlen/digits=7-4 55.45n ± 0% 35.91n ± 0% -35.23% (p=0.000 n=40)
AppendUintVarlen/digits=8-4 57.11n ± 0% 36.80n ± 0% -35.56% (p=0.000 n=40)
AppendUintVarlen/digits=9-4 59.28n ± 0% 39.42n ± 0% -33.50% (p=0.000 n=40)
AppendUintVarlen/digits=10-4 71.62n ± 0% 42.94n ± 0% -40.04% (p=0.000 n=40)
AppendUintVarlen/digits=11-4 91.41n ± 0% 48.57n ± 0% -46.87% (p=0.000 n=40)
AppendUintVarlen/digits=12-4 106.50n ± 0% 50.70n ± 0% -52.39% (p=0.000 n=40)
AppendUintVarlen/digits=13-4 121.90n ± 0% 52.07n ± 0% -57.28% (p=0.000 n=40)
AppendUintVarlen/digits=14-4 129.70n ± 0% 48.07n ± 0% -62.94% (p=0.000 n=40)
AppendUintVarlen/digits=15-4 148.50n ± 0% 56.45n ± 0% -61.99% (p=0.000 n=40)
AppendUintVarlen/digits=16-4 167.40n ± 0% 58.67n ± 0% -64.95% (p=0.000 n=40)
AppendUintVarlen/digits=17-4 179.70n ± 0% 59.83n ± 0% -66.71% (p=0.000 n=40)
AppendUintVarlen/digits=18-4 186.00n ± 0% 53.78n ± 0% -71.09% (p=0.000 n=40)
AppendUintVarlen/digits=19-4 216.50n ± 0% 62.13n ± 0% -71.30% (p=0.000 n=40)
AppendUintVarlen/digits=20-4 246.80n ± 0% 62.96n ± 0% -74.49% (p=0.000 n=40)
geomean 136.3n 95.52n -29.95%
host: s7:GOARCH=386
│ 428dc15ab39 │ c6ec0aa13de │
│ sec/op │ sec/op vs base │
AppendFloat/Decimal-4 51.07n ± 1% 51.05n ± 0% ~ (p=0.346 n=40)
AppendFloat/Float-4 94.44n ± 1% 95.05n ± 0% ~ (p=0.343 n=40)
AppendFloat/Exp-4 97.89n ± 0% 98.59n ± 0% ~ (p=0.271 n=40)
AppendFloat/NegExp-4 98.22n ± 1% 99.27n ± 0% ~ (p=0.283 n=40)
AppendFloat/LongExp-4 100.3n ± 0% 101.4n ± 0% ~ (p=0.001 n=40)
AppendFloat/Big-4 109.1n ± 0% 110.0n ± 1% ~ (p=0.141 n=40)
AppendFloat/BinaryExp-4 53.98n ± 1% 35.74n ± 1% -33.80% (p=0.000 n=40)
AppendFloat/32Integer-4 49.90n ± 0% 50.41n ± 0% ~ (p=0.005 n=40)
AppendFloat/32ExactFraction-4 78.22n ± 0% 79.49n ± 0% +1.62% (p=0.000 n=40)
AppendFloat/32Point-4 75.75n ± 1% 75.90n ± 0% ~ (p=0.119 n=40)
AppendFloat/32Exp-4 89.74n ± 1% 90.58n ± 0% ~ (p=0.088 n=40)
AppendFloat/32NegExp-4 79.34n ± 1% 80.22n ± 0% ~ (p=0.005 n=40)
AppendFloat/32Shortest-4 74.46n ± 1% 74.43n ± 1% ~ (p=1.000 n=40)
AppendFloat/32Fixed8Hard-4 47.28n ± 1% 41.62n ± 0% -11.97% (p=0.000 n=40)
AppendFloat/32Fixed9Hard-4 64.92n ± 1% 63.72n ± 1% -1.84% (p=0.000 n=40)
AppendFloat/64Fixed1-4 58.40n ± 1% 57.19n ± 1% -2.07% (p=0.000 n=40)
AppendFloat/64Fixed2-4 55.79n ± 1% 54.55n ± 1% -2.23% (p=0.000 n=40)
AppendFloat/64Fixed3-4 56.70n ± 1% 54.95n ± 0% -3.07% (p=0.000 n=40)
AppendFloat/64Fixed4-4 51.85n ± 1% 51.18n ± 0% -1.31% (p=0.000 n=40)
AppendFloat/64Fixed12-4 74.00n ± 0% 65.02n ± 0% -12.13% (p=0.000 n=40)
AppendFloat/64Fixed16-4 80.23n ± 1% 63.04n ± 0% -21.43% (p=0.000 n=40)
AppendFloat/64Fixed12Hard-4 70.64n ± 1% 60.83n ± 1% -13.89% (p=0.000 n=40)
AppendFloat/64Fixed17Hard-4 86.02n ± 1% 69.36n ± 0% -19.37% (p=0.000 n=40)
AppendFloat/64Fixed18Hard-4 3.736µ ± 1% 3.795µ ± 0% ~ (p=0.010 n=40)
AppendFloat/Slowpath64-4 99.18n ± 1% 100.25n ± 0% ~ (p=0.003 n=40)
AppendFloat/SlowpathDenormal64-4 97.35n ± 1% 98.41n ± 0% +1.08% (p=0.001 n=40)
AppendUint-4 356.3n ± 1% 291.2n ± 0% -18.30% (p=0.000 n=40)
AppendUintVarlen/digits=1-4 3.923n ± 0% 3.919n ± 1% ~ (p=0.061 n=40)
AppendUintVarlen/digits=2-4 3.917n ± 1% 3.924n ± 0% ~ (p=0.048 n=40)
AppendUintVarlen/digits=3-4 17.205n ± 0% 9.772n ± 0% -43.20% (p=0.000 n=40)
AppendUintVarlen/digits=4-4 17.18n ± 0% 10.16n ± 1% -40.86% (p=0.000 n=40)
AppendUintVarlen/digits=5-4 18.33n ± 1% 10.92n ± 0% -40.43% (p=0.000 n=40)
AppendUintVarlen/digits=6-4 18.67n ± 1% 11.31n ± 0% -39.42% (p=0.000 n=40)
AppendUintVarlen/digits=7-4 19.77n ± 1% 12.08n ± 0% -38.90% (p=0.000 n=40)
AppendUintVarlen/digits=8-4 19.95n ± 1% 12.44n ± 1% -37.64% (p=0.000 n=40)
AppendUintVarlen/digits=9-4 21.44n ± 1% 13.61n ± 1% -36.50% (p=0.000 n=40)
AppendUintVarlen/digits=10-4 24.31n ± 0% 17.94n ± 0% -26.20% (p=0.000 n=40)
AppendUintVarlen/digits=11-4 27.75n ± 1% 18.12n ± 0% -34.70% (p=0.000 n=40)
AppendUintVarlen/digits=12-4 28.76n ± 1% 18.99n ± 0% -33.95% (p=0.000 n=40)
AppendUintVarlen/digits=13-4 29.12n ± 1% 19.28n ± 0% -33.80% (p=0.000 n=40)
AppendUintVarlen/digits=14-4 30.56n ± 0% 20.07n ± 1% -34.30% (p=0.000 n=40)
AppendUintVarlen/digits=15-4 30.71n ± 1% 20.48n ± 0% -33.33% (p=0.000 n=40)
AppendUintVarlen/digits=16-4 31.86n ± 0% 21.32n ± 0% -33.08% (p=0.000 n=40)
AppendUintVarlen/digits=17-4 31.51n ± 1% 21.43n ± 1% -31.96% (p=0.000 n=40)
AppendUintVarlen/digits=18-4 32.46n ± 0% 22.26n ± 1% -31.44% (p=0.000 n=40)
AppendUintVarlen/digits=19-4 35.42n ± 1% 27.25n ± 1% -23.09% (p=0.000 n=40)
AppendUintVarlen/digits=20-4 39.50n ± 2% 26.94n ± 1% -31.80% (p=0.000 n=40)
geomean 48.59n 39.98n -17.73%
host: linux-386
│ 428dc15ab39 │ c6ec0aa13de │
│ sec/op │ sec/op vs base │
AppendFloat/Decimal-4 148.4n ± 2% 147.8n ± 1% ~ (p=0.053 n=40)
AppendFloat/Float-4 284.1n ± 2% 281.9n ± 1% ~ (p=0.001 n=40)
AppendFloat/Exp-4 294.5n ± 3% 292.7n ± 1% ~ (p=0.035 n=40)
AppendFloat/NegExp-4 295.4n ± 1% 295.9n ± 3% ~ (p=0.799 n=40)
AppendFloat/LongExp-4 305.8n ± 2% 304.9n ± 2% ~ (p=0.186 n=40)
AppendFloat/Big-4 340.1n ± 3% 340.8n ± 4% ~ (p=0.069 n=40)
AppendFloat/BinaryExp-4 139.1n ± 0% 100.7n ± 1% -27.61% (p=0.000 n=40)
AppendFloat/32Integer-4 149.2n ± 2% 148.4n ± 3% ~ (p=0.450 n=40)
AppendFloat/32ExactFraction-4 247.1n ± 4% 249.9n ± 3% ~ (p=0.005 n=40)
AppendFloat/32Point-4 231.5n ± 4% 233.9n ± 2% ~ (p=0.288 n=40)
AppendFloat/32Exp-4 286.9n ± 3% 284.5n ± 0% ~ (p=0.015 n=40)
AppendFloat/32NegExp-4 244.5n ± 1% 244.3n ± 4% ~ (p=0.637 n=40)
AppendFloat/32Shortest-4 227.4n ± 0% 227.2n ± 1% ~ (p=0.161 n=40)
AppendFloat/32Fixed8Hard-4 146.8n ± 1% 123.7n ± 2% -15.71% (p=0.000 n=40)
AppendFloat/32Fixed9Hard-4 218.7n ± 3% 204.7n ± 1% -6.42% (p=0.000 n=40)
AppendFloat/64Fixed1-4 194.3n ± 0% 183.7n ± 3% -5.51% (p=0.000 n=40)
AppendFloat/64Fixed2-4 184.8n ± 1% 172.8n ± 0% -6.47% (p=0.000 n=40)
AppendFloat/64Fixed3-4 186.1n ± 3% 174.6n ± 3% -6.21% (p=0.000 n=40)
AppendFloat/64Fixed4-4 164.9n ± 3% 159.1n ± 3% -3.55% (p=0.000 n=40)
AppendFloat/64Fixed12-4 233.9n ± 2% 206.7n ± 3% -11.63% (p=0.000 n=40)
AppendFloat/64Fixed16-4 253.2n ± 4% 201.5n ± 1% -20.40% (p=0.000 n=40)
AppendFloat/64Fixed12Hard-4 224.0n ± 1% 194.4n ± 1% -13.23% (p=0.000 n=40)
AppendFloat/64Fixed17Hard-4 282.4n ± 2% 231.5n ± 4% -18.01% (p=0.000 n=40)
AppendFloat/64Fixed18Hard-4 15.92µ ± 3% 15.73µ ± 2% ~ (p=0.172 n=40)
AppendFloat/Slowpath64-4 305.2n ± 2% 300.0n ± 3% ~ (p=0.016 n=40)
AppendFloat/SlowpathDenormal64-4 297.1n ± 2% 294.0n ± 1% ~ (p=0.075 n=40)
AppendUint-4 1218.5n ± 1% 946.2n ± 1% -22.34% (p=0.000 n=40)
AppendUintVarlen/digits=1-4 8.735n ± 2% 9.046n ± 3% +3.56% (p=0.000 n=40)
AppendUintVarlen/digits=2-4 8.752n ± 1% 8.990n ± 1% +2.71% (p=0.000 n=40)
AppendUintVarlen/digits=3-4 32.45n ± 2% 21.84n ± 1% -32.72% (p=0.000 n=40)
AppendUintVarlen/digits=4-4 33.23n ± 1% 23.93n ± 3% -27.99% (p=0.000 n=40)
AppendUintVarlen/digits=5-4 39.00n ± 3% 27.61n ± 2% -29.18% (p=0.000 n=40)
AppendUintVarlen/digits=6-4 38.87n ± 2% 28.76n ± 2% -26.00% (p=0.000 n=40)
AppendUintVarlen/digits=7-4 42.55n ± 1% 31.13n ± 3% -26.84% (p=0.000 n=40)
AppendUintVarlen/digits=8-4 43.13n ± 3% 33.26n ± 1% -22.88% (p=0.000 n=40)
AppendUintVarlen/digits=9-4 48.54n ± 3% 36.96n ± 1% -23.86% (p=0.000 n=40)
AppendUintVarlen/digits=10-4 68.81n ± 1% 51.20n ± 1% -25.59% (p=0.000 n=40)
AppendUintVarlen/digits=11-4 78.96n ± 1% 52.99n ± 1% -32.89% (p=0.000 n=40)
AppendUintVarlen/digits=12-4 83.14n ± 2% 55.37n ± 2% -33.40% (p=0.000 n=40)
AppendUintVarlen/digits=13-4 83.74n ± 1% 57.30n ± 2% -31.58% (p=0.000 n=40)
AppendUintVarlen/digits=14-4 90.47n ± 1% 58.75n ± 3% -35.06% (p=0.000 n=40)
AppendUintVarlen/digits=15-4 90.35n ± 3% 61.18n ± 1% -32.28% (p=0.000 n=40)
AppendUintVarlen/digits=16-4 94.12n ± 1% 63.77n ± 2% -32.25% (p=0.000 n=40)
AppendUintVarlen/digits=17-4 93.81n ± 0% 64.35n ± 3% -31.40% (p=0.000 n=40)
AppendUintVarlen/digits=18-4 99.25n ± 1% 67.18n ± 3% -32.31% (p=0.000 n=40)
AppendUintVarlen/digits=19-4 118.70n ± 0% 81.28n ± 1% -31.52% (p=0.000 n=40)
AppendUintVarlen/digits=20-4 135.90n ± 1% 83.23n ± 1% -38.76% (p=0.000 n=40)
geomean 140.3n 117.7n -16.12%
Change-Id: If5e2151c397701b23dbc69f20e57b99728898e90
Reviewed-on: https://go-review.googlesource.com/c/go/+/712662
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Alan Donovan <adonovan@google.com>
This commit is contained in:
Russ Cox
parent
e5688d0bdd
commit
8378276d66
3 changed files with 204 additions and 116 deletions
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@ -483,7 +483,7 @@ func fmtB(dst []byte, neg bool, mant uint64, exp int, flt *floatInfo) []byte {
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}
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// mantissa
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dst, _ = formatBits(dst, mant, 10, false, true)
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dst = AppendUint(dst, mant, 10)
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// p
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dst = append(dst, 'p')
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@ -493,7 +493,7 @@ func fmtB(dst []byte, neg bool, mant uint64, exp int, flt *floatInfo) []byte {
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if exp >= 0 {
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dst = append(dst, '+')
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}
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dst, _ = formatBits(dst, uint64(exp), 10, exp < 0, true)
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dst = AppendInt(dst, int64(exp), 10)
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return dst
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}
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@ -192,30 +192,9 @@ func formatDecimal(d *decimalSlice, m uint64, trunc bool, roundUp bool, prec int
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m /= 10
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trimmed++
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}
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// render digits (similar to formatBits)
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n := uint(prec)
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// render digits
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formatBase10(d.d[:prec], m)
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d.nd = prec
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v := m
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for v >= 100 {
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var v1, v2 uint64
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if v>>32 == 0 {
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v1, v2 = uint64(uint32(v)/100), uint64(uint32(v)%100)
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} else {
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v1, v2 = v/100, v%100
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}
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n -= 2
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d.d[n+1] = smallsString[2*v2+1]
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d.d[n+0] = smallsString[2*v2+0]
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v = v1
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}
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if v > 0 {
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n--
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d.d[n] = smallsString[2*v+1]
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}
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if v >= 10 {
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n--
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d.d[n] = smallsString[2*v]
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}
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for d.d[d.nd-1] == '0' {
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d.nd--
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trimmed++
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@ -448,8 +427,8 @@ func ryuDigits32(d *decimalSlice, lower, central, upper uint32,
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n := endindex
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for n > d.nd {
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v1, v2 := v/100, v%100
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d.d[n] = smallsString[2*v2+1]
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d.d[n-1] = smallsString[2*v2+0]
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d.d[n] = smalls[2*v2+1]
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d.d[n-1] = smalls[2*v2+0]
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n -= 2
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v = v1
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}
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@ -535,7 +514,7 @@ func divisibleByPower5(m uint64, k int) bool {
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// divmod1e9 computes quotient and remainder of division by 1e9,
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// avoiding runtime uint64 division on 32-bit platforms.
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func divmod1e9(x uint64) (uint32, uint32) {
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if !host32bit {
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if host64bit {
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return uint32(x / 1e9), uint32(x % 1e9)
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}
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// Use the same sequence of operations as the amd64 compiler.
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@ -4,17 +4,23 @@
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package strconv
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import "math/bits"
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const fastSmalls = true // enable fast path for small integers
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import (
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"math/bits"
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"runtime"
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)
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// FormatUint returns the string representation of i in the given base,
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// for 2 <= base <= 36. The result uses the lower-case letters 'a' to 'z'
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// for digit values >= 10.
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func FormatUint(i uint64, base int) string {
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if fastSmalls && i < nSmalls && base == 10 {
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if base == 10 {
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if i < nSmalls {
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return small(int(i))
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}
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var a [24]byte
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j := formatBase10(a[:], i)
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return string(a[j:])
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}
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_, s := formatBits(nil, i, base, false, false)
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return s
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}
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@ -23,9 +29,22 @@ func FormatUint(i uint64, base int) string {
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// for 2 <= base <= 36. The result uses the lower-case letters 'a' to 'z'
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// for digit values >= 10.
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func FormatInt(i int64, base int) string {
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if fastSmalls && 0 <= i && i < nSmalls && base == 10 {
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if base == 10 {
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if 0 <= i && i < nSmalls {
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return small(int(i))
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}
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var a [24]byte
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u := uint64(i)
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if i < 0 {
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u = -u
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}
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j := formatBase10(a[:], u)
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if i < 0 {
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j--
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a[j] = '-'
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}
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return string(a[j:])
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}
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_, s := formatBits(nil, uint64(i), base, i < 0, false)
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return s
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}
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@ -38,46 +57,29 @@ func Itoa(i int) string {
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// AppendInt appends the string form of the integer i,
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// as generated by [FormatInt], to dst and returns the extended buffer.
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func AppendInt(dst []byte, i int64, base int) []byte {
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if fastSmalls && 0 <= i && i < nSmalls && base == 10 {
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return append(dst, small(int(i))...)
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u := uint64(i)
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if i < 0 {
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dst = append(dst, '-')
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u = -u
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}
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dst, _ = formatBits(dst, uint64(i), base, i < 0, true)
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return dst
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return AppendUint(dst, u, base)
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}
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// AppendUint appends the string form of the unsigned integer i,
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// as generated by [FormatUint], to dst and returns the extended buffer.
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func AppendUint(dst []byte, i uint64, base int) []byte {
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if fastSmalls && i < nSmalls && base == 10 {
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if base == 10 {
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if i < nSmalls {
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return append(dst, small(int(i))...)
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}
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var a [24]byte
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j := formatBase10(a[:], i)
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return append(dst, a[j:]...)
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}
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dst, _ = formatBits(dst, i, base, false, true)
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return dst
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}
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// small returns the string for an i with 0 <= i < nSmalls.
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func small(i int) string {
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if i < 10 {
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return digits[i : i+1]
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}
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return smallsString[i*2 : i*2+2]
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}
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const nSmalls = 100
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const smallsString = "00010203040506070809" +
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"10111213141516171819" +
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"20212223242526272829" +
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"30313233343536373839" +
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"40414243444546474849" +
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"50515253545556575859" +
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"60616263646566676869" +
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"70717273747576777879" +
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"80818283848586878889" +
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"90919293949596979899"
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const host32bit = ^uint(0)>>32 == 0
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const digits = "0123456789abcdefghijklmnopqrstuvwxyz"
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// formatBits computes the string representation of u in the given base.
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@ -85,15 +87,15 @@ const digits = "0123456789abcdefghijklmnopqrstuvwxyz"
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// set, the string is appended to dst and the resulting byte slice is
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// returned as the first result value; otherwise the string is returned
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// as the second result value.
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// The caller is expected to have handled base 10 separately for speed.
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func formatBits(dst []byte, u uint64, base int, neg, append_ bool) (d []byte, s string) {
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if base < 2 || base > len(digits) {
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if base < 2 || base == 10 || base > len(digits) {
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panic("strconv: illegal AppendInt/FormatInt base")
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}
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// 2 <= base && base <= len(digits)
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var a [64 + 1]byte // +1 for sign of 64bit value in base 2
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i := len(a)
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if neg {
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u = -u
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}
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@ -101,56 +103,7 @@ func formatBits(dst []byte, u uint64, base int, neg, append_ bool) (d []byte, s
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// convert bits
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// We use uint values where we can because those will
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// fit into a single register even on a 32bit machine.
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if base == 10 {
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// common case: use constants for / because
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// the compiler can optimize it into a multiply+shift
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if host32bit {
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// convert the lower digits using 32bit operations
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for u >= 1e9 {
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// Avoid using r = a%b in addition to q = a/b
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// since 64bit division and modulo operations
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// are calculated by runtime functions on 32bit machines.
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q := u / 1e9
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us := uint(u - q*1e9) // u % 1e9 fits into a uint
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for j := 4; j > 0; j-- {
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is := us % 100 * 2
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us /= 100
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i -= 2
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a[i+1] = smallsString[is+1]
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a[i+0] = smallsString[is+0]
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}
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// us < 10, since it contains the last digit
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// from the initial 9-digit us.
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i--
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a[i] = smallsString[us*2+1]
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u = q
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}
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// u < 1e9
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}
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// u guaranteed to fit into a uint
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us := uint(u)
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for us >= 100 {
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is := us % 100 * 2
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us /= 100
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i -= 2
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a[i+1] = smallsString[is+1]
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a[i+0] = smallsString[is+0]
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}
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// us < 100
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is := us * 2
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i--
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a[i] = smallsString[is+1]
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if us >= 10 {
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i--
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a[i] = smallsString[is]
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}
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} else if isPowerOfTwo(base) {
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if isPowerOfTwo(base) {
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// Use shifts and masks instead of / and %.
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shift := uint(bits.TrailingZeros(uint(base)))
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b := uint64(base)
|
||||
|
|
@ -197,3 +150,159 @@ func formatBits(dst []byte, u uint64, base int, neg, append_ bool) (d []byte, s
|
|||
func isPowerOfTwo(x int) bool {
|
||||
return x&(x-1) == 0
|
||||
}
|
||||
|
||||
const nSmalls = 100
|
||||
|
||||
// smalls is the formatting of 00..99 concatenated.
|
||||
// It is then padded out with 56 x's to 256 bytes,
|
||||
// so that smalls[x&0xFF] has no bounds check.
|
||||
//
|
||||
// TODO(rsc): Once the compiler does a better job
|
||||
// at tracking mod bounds, the &0xFF should not be needed:
|
||||
// go.dev/issue/75954 and go.dev/issue/63110.
|
||||
const smalls = "00010203040506070809" +
|
||||
"10111213141516171819" +
|
||||
"20212223242526272829" +
|
||||
"30313233343536373839" +
|
||||
"40414243444546474849" +
|
||||
"50515253545556575859" +
|
||||
"60616263646566676869" +
|
||||
"70717273747576777879" +
|
||||
"80818283848586878889" +
|
||||
"90919293949596979899" +
|
||||
"xxxxxxxxxxxxxxxxxxxx" +
|
||||
"xxxxxxxxxxxxxxxxxxxx" +
|
||||
"xxxxxxxxxxxxxxxxxxxx" +
|
||||
"xxxxxxxxxxxxxxxxxxxx" +
|
||||
"xxxxxxxxxxxxxxxxxxxx" +
|
||||
"xxxxxx"
|
||||
|
||||
const host64bit = ^uint(0)>>32 != 0
|
||||
|
||||
// small returns the string for an i with 0 <= i < nSmalls.
|
||||
func small(i int) string {
|
||||
if i < 10 {
|
||||
return digits[i : i+1]
|
||||
}
|
||||
return smalls[i*2 : i*2+2]
|
||||
}
|
||||
|
||||
// formatBase10 formats the decimal representation of u into the tail of a
|
||||
// and returns the offset of the first byte written to a. That is, after
|
||||
//
|
||||
// i := formatBase10(a, u)
|
||||
//
|
||||
// the decimal representation is in a[i:].
|
||||
func formatBase10(a []byte, u uint64) int {
|
||||
// Decide implementation strategy based on architecture.
|
||||
const (
|
||||
// 64-bit systems can work in 64-bit math the whole time
|
||||
// or can split the uint64 into uint32-sized chunks.
|
||||
// On most systems, the uint32 math is faster, but not all.
|
||||
// The decision here is based on benchmarking.
|
||||
itoaPure64 = host64bit && runtime.GOARCH != "amd64" && runtime.GOARCH != "arm64" && runtime.GOARCH != "s390x"
|
||||
|
||||
// 64-bit systems can all use 64-bit div and mod by a constant,
|
||||
// which the compiler rewrites to use 64x64→128-bit multiplies.
|
||||
itoaDivMod64 = host64bit // can use 64-bit div/mod by constant
|
||||
)
|
||||
|
||||
if itoaPure64 {
|
||||
// Convert 2 digits at a time, using 64-bit math.
|
||||
i := len(a)
|
||||
u := uint(u)
|
||||
for u >= 100 {
|
||||
var dd uint
|
||||
u, dd = u/100, (u%100)*2
|
||||
i -= 2
|
||||
a[i+0], a[i+1] = smalls[(dd+0)&0xFF], smalls[(dd+1)&0xFF]
|
||||
}
|
||||
|
||||
dd := u * 2
|
||||
i--
|
||||
a[i] = smalls[(dd+1)&0xFF]
|
||||
if u >= 10 {
|
||||
i--
|
||||
a[i] = smalls[(dd+0)&0xFF]
|
||||
}
|
||||
return i
|
||||
}
|
||||
|
||||
// Convert 9-digit chunks using 32-bit math.
|
||||
// Most numbers are small, so the comparison u >= 1e9 is usually pure overhead,
|
||||
// so we approximate it by u>>29 != 0, which is usually faster and good enough.
|
||||
i := len(a)
|
||||
for (host64bit && u>>29 != 0) || (!host64bit && (u>>32 != 0 || uint32(u)>>29 != 0)) {
|
||||
var lo uint32
|
||||
if itoaDivMod64 {
|
||||
u, lo = u/1e9, uint32(u%1e9)
|
||||
} else {
|
||||
// On 64-bit systems the compiler rewrites the div and mod above
|
||||
// into a 64x64→128-bit multiply (https://godbolt.org/z/EPnK8zvMK):
|
||||
// hi, _ := bits.Mul64(u>>1, 0x89705f4136b4a598)
|
||||
// q := hi >> 28
|
||||
// lo = uint32(u - q*1e9)
|
||||
// u = q
|
||||
// On 32-bit systems, the compiler invokes a uint64 software divide,
|
||||
// which is quite slow. We could write the bits.Mul64 code above
|
||||
// but even that is slower than we'd like, since it calls a software mul64
|
||||
// instead of having a hardware instruction to use.
|
||||
// Instead we inline bits.Mul64 here and change y0/y1 to constants.
|
||||
// The compiler does use direct 32x32→64-bit multiplies for this code.
|
||||
//
|
||||
// For lots more about division by multiplication see Warren, _Hacker's Delight_.
|
||||
// For a concise overview, see the first two sections of
|
||||
// https://ridiculousfish.com/blog/posts/labor-of-division-episode-iii.html.
|
||||
const mask32 = 1<<32 - 1
|
||||
x0 := ((u >> 1) & mask32)
|
||||
x1 := (u >> 1) >> 32
|
||||
const y0 = 0x36b4a598
|
||||
const y1 = 0x89705f41
|
||||
w0 := x0 * y0
|
||||
t := x1*y0 + w0>>32
|
||||
w1 := t & mask32
|
||||
w2 := t >> 32
|
||||
w1 += x0 * y1
|
||||
hi := x1*y1 + w2 + w1>>32
|
||||
q := hi >> 28
|
||||
|
||||
lo = uint32(u) - uint32(q)*1e9 // uint32(u - q*1e9) but faster
|
||||
u = q
|
||||
}
|
||||
|
||||
// Convert 9 digits.
|
||||
for range 4 {
|
||||
var dd uint32
|
||||
lo, dd = lo/100, (lo%100)*2
|
||||
i -= 2
|
||||
a[i+0], a[i+1] = smalls[(dd+0)&0xFF], smalls[(dd+1)&0xFF]
|
||||
}
|
||||
i--
|
||||
a[i] = smalls[(lo*2+1)&0xFF]
|
||||
|
||||
// If we'd been using u >= 1e9 then we would be guaranteed that u/1e9 > 0,
|
||||
// but since we used u>>29 != 0, u/1e9 might be 0, so we might be done.
|
||||
// (If u is now 0, then at the start we had 2²⁹ ≤ u < 10⁹, so it was still correct
|
||||
// to write 9 digits; we have not accidentally written any leading zeros.)
|
||||
if u == 0 {
|
||||
return i
|
||||
}
|
||||
}
|
||||
|
||||
// Convert final chunk, at most 8 digits.
|
||||
lo := uint32(u)
|
||||
for lo >= 100 {
|
||||
var dd uint32
|
||||
lo, dd = lo/100, (lo%100)*2
|
||||
i -= 2
|
||||
a[i+0], a[i+1] = smalls[(dd+0)&0xFF], smalls[(dd+1)&0xFF]
|
||||
}
|
||||
i--
|
||||
dd := lo * 2
|
||||
a[i] = smalls[(dd+1)&0xFF]
|
||||
if lo >= 10 {
|
||||
i--
|
||||
a[i] = smalls[(dd+0)&0xFF]
|
||||
}
|
||||
return i
|
||||
}
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue