aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/go/_std_1.22/src/math/rand/v2
diff options
context:
space:
mode:
authormaxim-yurchuk <maxim-yurchuk@yandex-team.com>2024-10-09 12:29:46 +0300
committermaxim-yurchuk <maxim-yurchuk@yandex-team.com>2024-10-09 13:14:22 +0300
commit9731d8a4bb7ee2cc8554eaf133bb85498a4c7d80 (patch)
treea8fb3181d5947c0d78cf402aa56e686130179049 /contrib/go/_std_1.22/src/math/rand/v2
parenta44b779cd359f06c3ebbef4ec98c6b38609d9d85 (diff)
downloadydb-9731d8a4bb7ee2cc8554eaf133bb85498a4c7d80.tar.gz
publishFullContrib: true for ydb
<HIDDEN_URL> commit_hash:c82a80ac4594723cebf2c7387dec9c60217f603e
Diffstat (limited to 'contrib/go/_std_1.22/src/math/rand/v2')
-rw-r--r--contrib/go/_std_1.22/src/math/rand/v2/chacha8.go46
-rw-r--r--contrib/go/_std_1.22/src/math/rand/v2/exp.go222
-rw-r--r--contrib/go/_std_1.22/src/math/rand/v2/normal.go157
-rw-r--r--contrib/go/_std_1.22/src/math/rand/v2/pcg.go121
-rw-r--r--contrib/go/_std_1.22/src/math/rand/v2/rand.go363
-rw-r--r--contrib/go/_std_1.22/src/math/rand/v2/ya.make14
-rw-r--r--contrib/go/_std_1.22/src/math/rand/v2/zipf.go77
7 files changed, 1000 insertions, 0 deletions
diff --git a/contrib/go/_std_1.22/src/math/rand/v2/chacha8.go b/contrib/go/_std_1.22/src/math/rand/v2/chacha8.go
new file mode 100644
index 0000000000..6b9aa72782
--- /dev/null
+++ b/contrib/go/_std_1.22/src/math/rand/v2/chacha8.go
@@ -0,0 +1,46 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package rand
+
+import "internal/chacha8rand"
+
+// A ChaCha8 is a ChaCha8-based cryptographically strong
+// random number generator.
+type ChaCha8 struct {
+ state chacha8rand.State
+}
+
+// NewChaCha8 returns a new ChaCha8 seeded with the given seed.
+func NewChaCha8(seed [32]byte) *ChaCha8 {
+ c := new(ChaCha8)
+ c.state.Init(seed)
+ return c
+}
+
+// Seed resets the ChaCha8 to behave the same way as NewChaCha8(seed).
+func (c *ChaCha8) Seed(seed [32]byte) {
+ c.state.Init(seed)
+}
+
+// Uint64 returns a uniformly distributed random uint64 value.
+func (c *ChaCha8) Uint64() uint64 {
+ for {
+ x, ok := c.state.Next()
+ if ok {
+ return x
+ }
+ c.state.Refill()
+ }
+}
+
+// UnmarshalBinary implements the encoding.BinaryUnmarshaler interface.
+func (c *ChaCha8) UnmarshalBinary(data []byte) error {
+ return chacha8rand.Unmarshal(&c.state, data)
+}
+
+// MarshalBinary implements the encoding.BinaryMarshaler interface.
+func (c *ChaCha8) MarshalBinary() ([]byte, error) {
+ return chacha8rand.Marshal(&c.state), nil
+}
diff --git a/contrib/go/_std_1.22/src/math/rand/v2/exp.go b/contrib/go/_std_1.22/src/math/rand/v2/exp.go
new file mode 100644
index 0000000000..ed7f7277bc
--- /dev/null
+++ b/contrib/go/_std_1.22/src/math/rand/v2/exp.go
@@ -0,0 +1,222 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package rand
+
+import (
+ "math"
+)
+
+/*
+ * Exponential distribution
+ *
+ * See "The Ziggurat Method for Generating Random Variables"
+ * (Marsaglia & Tsang, 2000)
+ * https://www.jstatsoft.org/v05/i08/paper [pdf]
+ */
+
+const (
+ re = 7.69711747013104972
+)
+
+// ExpFloat64 returns an exponentially distributed float64 in the range
+// (0, +math.MaxFloat64] with an exponential distribution whose rate parameter
+// (lambda) is 1 and whose mean is 1/lambda (1).
+// To produce a distribution with a different rate parameter,
+// callers can adjust the output using:
+//
+// sample = ExpFloat64() / desiredRateParameter
+func (r *Rand) ExpFloat64() float64 {
+ for {
+ u := r.Uint64()
+ j := uint32(u)
+ i := uint8(u >> 32)
+ x := float64(j) * float64(we[i])
+ if j < ke[i] {
+ return x
+ }
+ if i == 0 {
+ return re - math.Log(r.Float64())
+ }
+ if fe[i]+float32(r.Float64())*(fe[i-1]-fe[i]) < float32(math.Exp(-x)) {
+ return x
+ }
+ }
+}
+
+var ke = [256]uint32{
+ 0xe290a139, 0x0, 0x9beadebc, 0xc377ac71, 0xd4ddb990,
+ 0xde893fb8, 0xe4a8e87c, 0xe8dff16a, 0xebf2deab, 0xee49a6e8,
+ 0xf0204efd, 0xf19bdb8e, 0xf2d458bb, 0xf3da104b, 0xf4b86d78,
+ 0xf577ad8a, 0xf61de83d, 0xf6afb784, 0xf730a573, 0xf7a37651,
+ 0xf80a5bb6, 0xf867189d, 0xf8bb1b4f, 0xf9079062, 0xf94d70ca,
+ 0xf98d8c7d, 0xf9c8928a, 0xf9ff175b, 0xfa319996, 0xfa6085f8,
+ 0xfa8c3a62, 0xfab5084e, 0xfadb36c8, 0xfaff0410, 0xfb20a6ea,
+ 0xfb404fb4, 0xfb5e2951, 0xfb7a59e9, 0xfb95038c, 0xfbae44ba,
+ 0xfbc638d8, 0xfbdcf892, 0xfbf29a30, 0xfc0731df, 0xfc1ad1ed,
+ 0xfc2d8b02, 0xfc3f6c4d, 0xfc5083ac, 0xfc60ddd1, 0xfc708662,
+ 0xfc7f8810, 0xfc8decb4, 0xfc9bbd62, 0xfca9027c, 0xfcb5c3c3,
+ 0xfcc20864, 0xfccdd70a, 0xfcd935e3, 0xfce42ab0, 0xfceebace,
+ 0xfcf8eb3b, 0xfd02c0a0, 0xfd0c3f59, 0xfd156b7b, 0xfd1e48d6,
+ 0xfd26daff, 0xfd2f2552, 0xfd372af7, 0xfd3eeee5, 0xfd4673e7,
+ 0xfd4dbc9e, 0xfd54cb85, 0xfd5ba2f2, 0xfd62451b, 0xfd68b415,
+ 0xfd6ef1da, 0xfd750047, 0xfd7ae120, 0xfd809612, 0xfd8620b4,
+ 0xfd8b8285, 0xfd90bcf5, 0xfd95d15e, 0xfd9ac10b, 0xfd9f8d36,
+ 0xfda43708, 0xfda8bf9e, 0xfdad2806, 0xfdb17141, 0xfdb59c46,
+ 0xfdb9a9fd, 0xfdbd9b46, 0xfdc170f6, 0xfdc52bd8, 0xfdc8ccac,
+ 0xfdcc542d, 0xfdcfc30b, 0xfdd319ef, 0xfdd6597a, 0xfdd98245,
+ 0xfddc94e5, 0xfddf91e6, 0xfde279ce, 0xfde54d1f, 0xfde80c52,
+ 0xfdeab7de, 0xfded5034, 0xfdefd5be, 0xfdf248e3, 0xfdf4aa06,
+ 0xfdf6f984, 0xfdf937b6, 0xfdfb64f4, 0xfdfd818d, 0xfdff8dd0,
+ 0xfe018a08, 0xfe03767a, 0xfe05536c, 0xfe07211c, 0xfe08dfc9,
+ 0xfe0a8fab, 0xfe0c30fb, 0xfe0dc3ec, 0xfe0f48b1, 0xfe10bf76,
+ 0xfe122869, 0xfe1383b4, 0xfe14d17c, 0xfe1611e7, 0xfe174516,
+ 0xfe186b2a, 0xfe19843e, 0xfe1a9070, 0xfe1b8fd6, 0xfe1c8289,
+ 0xfe1d689b, 0xfe1e4220, 0xfe1f0f26, 0xfe1fcfbc, 0xfe2083ed,
+ 0xfe212bc3, 0xfe21c745, 0xfe225678, 0xfe22d95f, 0xfe234ffb,
+ 0xfe23ba4a, 0xfe241849, 0xfe2469f2, 0xfe24af3c, 0xfe24e81e,
+ 0xfe25148b, 0xfe253474, 0xfe2547c7, 0xfe254e70, 0xfe25485a,
+ 0xfe25356a, 0xfe251586, 0xfe24e88f, 0xfe24ae64, 0xfe2466e1,
+ 0xfe2411df, 0xfe23af34, 0xfe233eb4, 0xfe22c02c, 0xfe22336b,
+ 0xfe219838, 0xfe20ee58, 0xfe20358c, 0xfe1f6d92, 0xfe1e9621,
+ 0xfe1daef0, 0xfe1cb7ac, 0xfe1bb002, 0xfe1a9798, 0xfe196e0d,
+ 0xfe1832fd, 0xfe16e5fe, 0xfe15869d, 0xfe141464, 0xfe128ed3,
+ 0xfe10f565, 0xfe0f478c, 0xfe0d84b1, 0xfe0bac36, 0xfe09bd73,
+ 0xfe07b7b5, 0xfe059a40, 0xfe03644c, 0xfe011504, 0xfdfeab88,
+ 0xfdfc26e9, 0xfdf98629, 0xfdf6c83b, 0xfdf3ec01, 0xfdf0f04a,
+ 0xfdedd3d1, 0xfdea953d, 0xfde7331e, 0xfde3abe9, 0xfddffdfb,
+ 0xfddc2791, 0xfdd826cd, 0xfdd3f9a8, 0xfdcf9dfc, 0xfdcb1176,
+ 0xfdc65198, 0xfdc15bb3, 0xfdbc2ce2, 0xfdb6c206, 0xfdb117be,
+ 0xfdab2a63, 0xfda4f5fd, 0xfd9e7640, 0xfd97a67a, 0xfd908192,
+ 0xfd8901f2, 0xfd812182, 0xfd78d98e, 0xfd7022bb, 0xfd66f4ed,
+ 0xfd5d4732, 0xfd530f9c, 0xfd48432b, 0xfd3cd59a, 0xfd30b936,
+ 0xfd23dea4, 0xfd16349e, 0xfd07a7a3, 0xfcf8219b, 0xfce7895b,
+ 0xfcd5c220, 0xfcc2aadb, 0xfcae1d5e, 0xfc97ed4e, 0xfc7fe6d4,
+ 0xfc65ccf3, 0xfc495762, 0xfc2a2fc8, 0xfc07ee19, 0xfbe213c1,
+ 0xfbb8051a, 0xfb890078, 0xfb5411a5, 0xfb180005, 0xfad33482,
+ 0xfa839276, 0xfa263b32, 0xf9b72d1c, 0xf930a1a2, 0xf889f023,
+ 0xf7b577d2, 0xf69c650c, 0xf51530f0, 0xf2cb0e3c, 0xeeefb15d,
+ 0xe6da6ecf,
+}
+var we = [256]float32{
+ 2.0249555e-09, 1.486674e-11, 2.4409617e-11, 3.1968806e-11,
+ 3.844677e-11, 4.4228204e-11, 4.9516443e-11, 5.443359e-11,
+ 5.905944e-11, 6.344942e-11, 6.7643814e-11, 7.1672945e-11,
+ 7.556032e-11, 7.932458e-11, 8.298079e-11, 8.654132e-11,
+ 9.0016515e-11, 9.3415074e-11, 9.674443e-11, 1.0001099e-10,
+ 1.03220314e-10, 1.06377254e-10, 1.09486115e-10, 1.1255068e-10,
+ 1.1557435e-10, 1.1856015e-10, 1.2151083e-10, 1.2442886e-10,
+ 1.2731648e-10, 1.3017575e-10, 1.3300853e-10, 1.3581657e-10,
+ 1.3860142e-10, 1.4136457e-10, 1.4410738e-10, 1.4683108e-10,
+ 1.4953687e-10, 1.5222583e-10, 1.54899e-10, 1.5755733e-10,
+ 1.6020171e-10, 1.6283301e-10, 1.6545203e-10, 1.6805951e-10,
+ 1.7065617e-10, 1.732427e-10, 1.7581973e-10, 1.7838787e-10,
+ 1.8094774e-10, 1.8349985e-10, 1.8604476e-10, 1.8858298e-10,
+ 1.9111498e-10, 1.9364126e-10, 1.9616223e-10, 1.9867835e-10,
+ 2.0119004e-10, 2.0369768e-10, 2.0620168e-10, 2.087024e-10,
+ 2.1120022e-10, 2.136955e-10, 2.1618855e-10, 2.1867974e-10,
+ 2.2116936e-10, 2.2365775e-10, 2.261452e-10, 2.2863202e-10,
+ 2.311185e-10, 2.3360494e-10, 2.360916e-10, 2.3857874e-10,
+ 2.4106667e-10, 2.4355562e-10, 2.4604588e-10, 2.485377e-10,
+ 2.5103128e-10, 2.5352695e-10, 2.560249e-10, 2.585254e-10,
+ 2.6102867e-10, 2.6353494e-10, 2.6604446e-10, 2.6855745e-10,
+ 2.7107416e-10, 2.7359479e-10, 2.761196e-10, 2.7864877e-10,
+ 2.8118255e-10, 2.8372119e-10, 2.8626485e-10, 2.888138e-10,
+ 2.9136826e-10, 2.939284e-10, 2.9649452e-10, 2.9906677e-10,
+ 3.016454e-10, 3.0423064e-10, 3.0682268e-10, 3.0942177e-10,
+ 3.1202813e-10, 3.1464195e-10, 3.1726352e-10, 3.19893e-10,
+ 3.2253064e-10, 3.251767e-10, 3.2783135e-10, 3.3049485e-10,
+ 3.3316744e-10, 3.3584938e-10, 3.3854083e-10, 3.4124212e-10,
+ 3.4395342e-10, 3.46675e-10, 3.4940711e-10, 3.5215003e-10,
+ 3.5490397e-10, 3.5766917e-10, 3.6044595e-10, 3.6323455e-10,
+ 3.660352e-10, 3.6884823e-10, 3.7167386e-10, 3.745124e-10,
+ 3.773641e-10, 3.802293e-10, 3.8310827e-10, 3.860013e-10,
+ 3.8890866e-10, 3.918307e-10, 3.9476775e-10, 3.9772008e-10,
+ 4.0068804e-10, 4.0367196e-10, 4.0667217e-10, 4.09689e-10,
+ 4.1272286e-10, 4.1577405e-10, 4.1884296e-10, 4.2192994e-10,
+ 4.250354e-10, 4.281597e-10, 4.313033e-10, 4.3446652e-10,
+ 4.3764986e-10, 4.408537e-10, 4.4407847e-10, 4.4732465e-10,
+ 4.5059267e-10, 4.5388301e-10, 4.571962e-10, 4.6053267e-10,
+ 4.6389292e-10, 4.6727755e-10, 4.70687e-10, 4.741219e-10,
+ 4.7758275e-10, 4.810702e-10, 4.845848e-10, 4.8812715e-10,
+ 4.9169796e-10, 4.9529775e-10, 4.989273e-10, 5.0258725e-10,
+ 5.0627835e-10, 5.100013e-10, 5.1375687e-10, 5.1754584e-10,
+ 5.21369e-10, 5.2522725e-10, 5.2912136e-10, 5.330522e-10,
+ 5.370208e-10, 5.4102806e-10, 5.45075e-10, 5.491625e-10,
+ 5.532918e-10, 5.5746385e-10, 5.616799e-10, 5.6594107e-10,
+ 5.7024857e-10, 5.746037e-10, 5.7900773e-10, 5.834621e-10,
+ 5.8796823e-10, 5.925276e-10, 5.971417e-10, 6.018122e-10,
+ 6.065408e-10, 6.113292e-10, 6.1617933e-10, 6.2109295e-10,
+ 6.260722e-10, 6.3111916e-10, 6.3623595e-10, 6.4142497e-10,
+ 6.4668854e-10, 6.5202926e-10, 6.5744976e-10, 6.6295286e-10,
+ 6.6854156e-10, 6.742188e-10, 6.79988e-10, 6.858526e-10,
+ 6.9181616e-10, 6.978826e-10, 7.04056e-10, 7.103407e-10,
+ 7.167412e-10, 7.2326256e-10, 7.2990985e-10, 7.366886e-10,
+ 7.4360473e-10, 7.5066453e-10, 7.5787476e-10, 7.6524265e-10,
+ 7.7277595e-10, 7.80483e-10, 7.883728e-10, 7.9645507e-10,
+ 8.047402e-10, 8.1323964e-10, 8.219657e-10, 8.309319e-10,
+ 8.401528e-10, 8.496445e-10, 8.594247e-10, 8.6951274e-10,
+ 8.799301e-10, 8.9070046e-10, 9.018503e-10, 9.134092e-10,
+ 9.254101e-10, 9.378904e-10, 9.508923e-10, 9.644638e-10,
+ 9.786603e-10, 9.935448e-10, 1.0091913e-09, 1.025686e-09,
+ 1.0431306e-09, 1.0616465e-09, 1.08138e-09, 1.1025096e-09,
+ 1.1252564e-09, 1.1498986e-09, 1.1767932e-09, 1.206409e-09,
+ 1.2393786e-09, 1.276585e-09, 1.3193139e-09, 1.3695435e-09,
+ 1.4305498e-09, 1.508365e-09, 1.6160854e-09, 1.7921248e-09,
+}
+var fe = [256]float32{
+ 1, 0.9381437, 0.90046996, 0.87170434, 0.8477855, 0.8269933,
+ 0.8084217, 0.7915276, 0.77595687, 0.7614634, 0.7478686,
+ 0.7350381, 0.72286767, 0.71127474, 0.70019263, 0.6895665,
+ 0.67935055, 0.6695063, 0.66000086, 0.65080583, 0.6418967,
+ 0.63325197, 0.6248527, 0.6166822, 0.60872537, 0.60096896,
+ 0.5934009, 0.58601034, 0.5787874, 0.57172304, 0.5648092,
+ 0.5580383, 0.5514034, 0.5448982, 0.5385169, 0.53225386,
+ 0.5261042, 0.52006316, 0.5141264, 0.50828975, 0.5025495,
+ 0.496902, 0.49134386, 0.485872, 0.48048335, 0.4751752,
+ 0.46994483, 0.46478975, 0.45970762, 0.45469615, 0.44975325,
+ 0.44487688, 0.44006512, 0.43531612, 0.43062815, 0.42599955,
+ 0.42142874, 0.4169142, 0.41245446, 0.40804818, 0.403694,
+ 0.3993907, 0.39513698, 0.39093173, 0.38677382, 0.38266218,
+ 0.37859577, 0.37457356, 0.37059465, 0.3666581, 0.362763,
+ 0.35890847, 0.35509375, 0.351318, 0.3475805, 0.34388044,
+ 0.34021714, 0.3365899, 0.33299807, 0.32944095, 0.32591796,
+ 0.3224285, 0.3189719, 0.31554767, 0.31215525, 0.30879408,
+ 0.3054636, 0.3021634, 0.29889292, 0.2956517, 0.29243928,
+ 0.28925523, 0.28609908, 0.28297043, 0.27986884, 0.27679393,
+ 0.2737453, 0.2707226, 0.2677254, 0.26475343, 0.26180625,
+ 0.25888354, 0.25598502, 0.2531103, 0.25025907, 0.24743107,
+ 0.24462597, 0.24184346, 0.23908329, 0.23634516, 0.23362878,
+ 0.23093392, 0.2282603, 0.22560766, 0.22297576, 0.22036438,
+ 0.21777324, 0.21520215, 0.21265087, 0.21011916, 0.20760682,
+ 0.20511365, 0.20263945, 0.20018397, 0.19774707, 0.19532852,
+ 0.19292815, 0.19054577, 0.1881812, 0.18583426, 0.18350479,
+ 0.1811926, 0.17889754, 0.17661946, 0.17435817, 0.17211354,
+ 0.1698854, 0.16767362, 0.16547804, 0.16329853, 0.16113494,
+ 0.15898713, 0.15685499, 0.15473837, 0.15263714, 0.15055119,
+ 0.14848037, 0.14642459, 0.14438373, 0.14235765, 0.14034624,
+ 0.13834943, 0.13636707, 0.13439907, 0.13244532, 0.13050574,
+ 0.1285802, 0.12666863, 0.12477092, 0.12288698, 0.12101672,
+ 0.119160056, 0.1173169, 0.115487166, 0.11367077, 0.11186763,
+ 0.11007768, 0.10830083, 0.10653701, 0.10478614, 0.10304816,
+ 0.101323, 0.09961058, 0.09791085, 0.09622374, 0.09454919,
+ 0.09288713, 0.091237515, 0.08960028, 0.087975375, 0.08636274,
+ 0.08476233, 0.083174095, 0.081597984, 0.08003395, 0.07848195,
+ 0.076941945, 0.07541389, 0.07389775, 0.072393484, 0.07090106,
+ 0.069420435, 0.06795159, 0.066494495, 0.06504912, 0.063615434,
+ 0.062193416, 0.060783047, 0.059384305, 0.057997175,
+ 0.05662164, 0.05525769, 0.053905312, 0.052564494, 0.051235236,
+ 0.049917534, 0.048611384, 0.047316793, 0.046033762, 0.0447623,
+ 0.043502413, 0.042254124, 0.041017443, 0.039792392,
+ 0.038578995, 0.037377283, 0.036187284, 0.035009038,
+ 0.033842582, 0.032687962, 0.031545233, 0.030414443, 0.02929566,
+ 0.02818895, 0.027094385, 0.026012046, 0.024942026, 0.023884421,
+ 0.022839336, 0.021806888, 0.020787204, 0.019780423, 0.0187867,
+ 0.0178062, 0.016839107, 0.015885621, 0.014945968, 0.014020392,
+ 0.013109165, 0.012212592, 0.011331013, 0.01046481, 0.009614414,
+ 0.008780315, 0.007963077, 0.0071633533, 0.006381906,
+ 0.0056196423, 0.0048776558, 0.004157295, 0.0034602648,
+ 0.0027887989, 0.0021459677, 0.0015362998, 0.0009672693,
+ 0.00045413437,
+}
diff --git a/contrib/go/_std_1.22/src/math/rand/v2/normal.go b/contrib/go/_std_1.22/src/math/rand/v2/normal.go
new file mode 100644
index 0000000000..ea1ae409b4
--- /dev/null
+++ b/contrib/go/_std_1.22/src/math/rand/v2/normal.go
@@ -0,0 +1,157 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package rand
+
+import (
+ "math"
+)
+
+/*
+ * Normal distribution
+ *
+ * See "The Ziggurat Method for Generating Random Variables"
+ * (Marsaglia & Tsang, 2000)
+ * http://www.jstatsoft.org/v05/i08/paper [pdf]
+ */
+
+const (
+ rn = 3.442619855899
+)
+
+func absInt32(i int32) uint32 {
+ if i < 0 {
+ return uint32(-i)
+ }
+ return uint32(i)
+}
+
+// NormFloat64 returns a normally distributed float64 in
+// the range -math.MaxFloat64 through +math.MaxFloat64 inclusive,
+// with standard normal distribution (mean = 0, stddev = 1).
+// To produce a different normal distribution, callers can
+// adjust the output using:
+//
+// sample = NormFloat64() * desiredStdDev + desiredMean
+func (r *Rand) NormFloat64() float64 {
+ for {
+ u := r.Uint64()
+ j := int32(u) // Possibly negative
+ i := u >> 32 & 0x7F
+ x := float64(j) * float64(wn[i])
+ if absInt32(j) < kn[i] {
+ // This case should be hit better than 99% of the time.
+ return x
+ }
+
+ if i == 0 {
+ // This extra work is only required for the base strip.
+ for {
+ x = -math.Log(r.Float64()) * (1.0 / rn)
+ y := -math.Log(r.Float64())
+ if y+y >= x*x {
+ break
+ }
+ }
+ if j > 0 {
+ return rn + x
+ }
+ return -rn - x
+ }
+ if fn[i]+float32(r.Float64())*(fn[i-1]-fn[i]) < float32(math.Exp(-.5*x*x)) {
+ return x
+ }
+ }
+}
+
+var kn = [128]uint32{
+ 0x76ad2212, 0x0, 0x600f1b53, 0x6ce447a6, 0x725b46a2,
+ 0x7560051d, 0x774921eb, 0x789a25bd, 0x799045c3, 0x7a4bce5d,
+ 0x7adf629f, 0x7b5682a6, 0x7bb8a8c6, 0x7c0ae722, 0x7c50cce7,
+ 0x7c8cec5b, 0x7cc12cd6, 0x7ceefed2, 0x7d177e0b, 0x7d3b8883,
+ 0x7d5bce6c, 0x7d78dd64, 0x7d932886, 0x7dab0e57, 0x7dc0dd30,
+ 0x7dd4d688, 0x7de73185, 0x7df81cea, 0x7e07c0a3, 0x7e163efa,
+ 0x7e23b587, 0x7e303dfd, 0x7e3beec2, 0x7e46db77, 0x7e51155d,
+ 0x7e5aabb3, 0x7e63abf7, 0x7e6c222c, 0x7e741906, 0x7e7b9a18,
+ 0x7e82adfa, 0x7e895c63, 0x7e8fac4b, 0x7e95a3fb, 0x7e9b4924,
+ 0x7ea0a0ef, 0x7ea5b00d, 0x7eaa7ac3, 0x7eaf04f3, 0x7eb3522a,
+ 0x7eb765a5, 0x7ebb4259, 0x7ebeeafd, 0x7ec2620a, 0x7ec5a9c4,
+ 0x7ec8c441, 0x7ecbb365, 0x7ece78ed, 0x7ed11671, 0x7ed38d62,
+ 0x7ed5df12, 0x7ed80cb4, 0x7eda175c, 0x7edc0005, 0x7eddc78e,
+ 0x7edf6ebf, 0x7ee0f647, 0x7ee25ebe, 0x7ee3a8a9, 0x7ee4d473,
+ 0x7ee5e276, 0x7ee6d2f5, 0x7ee7a620, 0x7ee85c10, 0x7ee8f4cd,
+ 0x7ee97047, 0x7ee9ce59, 0x7eea0eca, 0x7eea3147, 0x7eea3568,
+ 0x7eea1aab, 0x7ee9e071, 0x7ee98602, 0x7ee90a88, 0x7ee86d08,
+ 0x7ee7ac6a, 0x7ee6c769, 0x7ee5bc9c, 0x7ee48a67, 0x7ee32efc,
+ 0x7ee1a857, 0x7edff42f, 0x7ede0ffa, 0x7edbf8d9, 0x7ed9ab94,
+ 0x7ed7248d, 0x7ed45fae, 0x7ed1585c, 0x7ece095f, 0x7eca6ccb,
+ 0x7ec67be2, 0x7ec22eee, 0x7ebd7d1a, 0x7eb85c35, 0x7eb2c075,
+ 0x7eac9c20, 0x7ea5df27, 0x7e9e769f, 0x7e964c16, 0x7e8d44ba,
+ 0x7e834033, 0x7e781728, 0x7e6b9933, 0x7e5d8a1a, 0x7e4d9ded,
+ 0x7e3b737a, 0x7e268c2f, 0x7e0e3ff5, 0x7df1aa5d, 0x7dcf8c72,
+ 0x7da61a1e, 0x7d72a0fb, 0x7d30e097, 0x7cd9b4ab, 0x7c600f1a,
+ 0x7ba90bdc, 0x7a722176, 0x77d664e5,
+}
+var wn = [128]float32{
+ 1.7290405e-09, 1.2680929e-10, 1.6897518e-10, 1.9862688e-10,
+ 2.2232431e-10, 2.4244937e-10, 2.601613e-10, 2.7611988e-10,
+ 2.9073963e-10, 3.042997e-10, 3.1699796e-10, 3.289802e-10,
+ 3.4035738e-10, 3.5121603e-10, 3.616251e-10, 3.7164058e-10,
+ 3.8130857e-10, 3.9066758e-10, 3.9975012e-10, 4.08584e-10,
+ 4.1719309e-10, 4.2559822e-10, 4.338176e-10, 4.418672e-10,
+ 4.497613e-10, 4.5751258e-10, 4.651324e-10, 4.7263105e-10,
+ 4.8001775e-10, 4.87301e-10, 4.944885e-10, 5.015873e-10,
+ 5.0860405e-10, 5.155446e-10, 5.2241467e-10, 5.2921934e-10,
+ 5.359635e-10, 5.426517e-10, 5.4928817e-10, 5.5587696e-10,
+ 5.624219e-10, 5.6892646e-10, 5.753941e-10, 5.818282e-10,
+ 5.882317e-10, 5.946077e-10, 6.00959e-10, 6.072884e-10,
+ 6.135985e-10, 6.19892e-10, 6.2617134e-10, 6.3243905e-10,
+ 6.386974e-10, 6.449488e-10, 6.511956e-10, 6.5744005e-10,
+ 6.6368433e-10, 6.699307e-10, 6.7618144e-10, 6.824387e-10,
+ 6.8870465e-10, 6.949815e-10, 7.012715e-10, 7.075768e-10,
+ 7.1389966e-10, 7.202424e-10, 7.266073e-10, 7.329966e-10,
+ 7.394128e-10, 7.4585826e-10, 7.5233547e-10, 7.58847e-10,
+ 7.653954e-10, 7.719835e-10, 7.7861395e-10, 7.852897e-10,
+ 7.920138e-10, 7.987892e-10, 8.0561924e-10, 8.125073e-10,
+ 8.194569e-10, 8.2647167e-10, 8.3355556e-10, 8.407127e-10,
+ 8.479473e-10, 8.55264e-10, 8.6266755e-10, 8.7016316e-10,
+ 8.777562e-10, 8.8545243e-10, 8.932582e-10, 9.0117996e-10,
+ 9.09225e-10, 9.174008e-10, 9.2571584e-10, 9.341788e-10,
+ 9.427997e-10, 9.515889e-10, 9.605579e-10, 9.697193e-10,
+ 9.790869e-10, 9.88676e-10, 9.985036e-10, 1.0085882e-09,
+ 1.0189509e-09, 1.0296151e-09, 1.0406069e-09, 1.0519566e-09,
+ 1.063698e-09, 1.0758702e-09, 1.0885183e-09, 1.1016947e-09,
+ 1.1154611e-09, 1.1298902e-09, 1.1450696e-09, 1.1611052e-09,
+ 1.1781276e-09, 1.1962995e-09, 1.2158287e-09, 1.2369856e-09,
+ 1.2601323e-09, 1.2857697e-09, 1.3146202e-09, 1.347784e-09,
+ 1.3870636e-09, 1.4357403e-09, 1.5008659e-09, 1.6030948e-09,
+}
+var fn = [128]float32{
+ 1, 0.9635997, 0.9362827, 0.9130436, 0.89228165, 0.87324303,
+ 0.8555006, 0.8387836, 0.8229072, 0.8077383, 0.793177,
+ 0.7791461, 0.7655842, 0.7524416, 0.73967725, 0.7272569,
+ 0.7151515, 0.7033361, 0.69178915, 0.68049186, 0.6694277,
+ 0.658582, 0.6479418, 0.63749546, 0.6272325, 0.6171434,
+ 0.6072195, 0.5974532, 0.58783704, 0.5783647, 0.56903,
+ 0.5598274, 0.5507518, 0.54179835, 0.5329627, 0.52424055,
+ 0.5156282, 0.50712204, 0.49871865, 0.49041483, 0.48220766,
+ 0.4740943, 0.46607214, 0.4581387, 0.45029163, 0.44252872,
+ 0.43484783, 0.427247, 0.41972435, 0.41227803, 0.40490642,
+ 0.39760786, 0.3903808, 0.3832238, 0.37613547, 0.36911446,
+ 0.3621595, 0.35526937, 0.34844297, 0.34167916, 0.33497685,
+ 0.3283351, 0.3217529, 0.3152294, 0.30876362, 0.30235484,
+ 0.29600215, 0.28970486, 0.2834622, 0.2772735, 0.27113807,
+ 0.2650553, 0.25902456, 0.2530453, 0.24711695, 0.241239,
+ 0.23541094, 0.22963232, 0.2239027, 0.21822165, 0.21258877,
+ 0.20700371, 0.20146611, 0.19597565, 0.19053204, 0.18513499,
+ 0.17978427, 0.17447963, 0.1692209, 0.16400786, 0.15884037,
+ 0.15371831, 0.14864157, 0.14361008, 0.13862377, 0.13368265,
+ 0.12878671, 0.12393598, 0.119130544, 0.11437051, 0.10965602,
+ 0.104987256, 0.10036444, 0.095787846, 0.0912578, 0.08677467,
+ 0.0823389, 0.077950984, 0.073611505, 0.06932112, 0.06508058,
+ 0.06089077, 0.056752663, 0.0526674, 0.048636295, 0.044660863,
+ 0.040742867, 0.03688439, 0.033087887, 0.029356318,
+ 0.025693292, 0.022103304, 0.018592102, 0.015167298,
+ 0.011839478, 0.008624485, 0.005548995, 0.0026696292,
+}
diff --git a/contrib/go/_std_1.22/src/math/rand/v2/pcg.go b/contrib/go/_std_1.22/src/math/rand/v2/pcg.go
new file mode 100644
index 0000000000..77708d799e
--- /dev/null
+++ b/contrib/go/_std_1.22/src/math/rand/v2/pcg.go
@@ -0,0 +1,121 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package rand
+
+import (
+ "errors"
+ "math/bits"
+)
+
+// https://numpy.org/devdocs/reference/random/upgrading-pcg64.html
+// https://github.com/imneme/pcg-cpp/commit/871d0494ee9c9a7b7c43f753e3d8ca47c26f8005
+
+// A PCG is a PCG generator with 128 bits of internal state.
+// A zero PCG is equivalent to NewPCG(0, 0).
+type PCG struct {
+ hi uint64
+ lo uint64
+}
+
+// NewPCG returns a new PCG seeded with the given values.
+func NewPCG(seed1, seed2 uint64) *PCG {
+ return &PCG{seed1, seed2}
+}
+
+// Seed resets the PCG to behave the same way as NewPCG(seed1, seed2).
+func (p *PCG) Seed(seed1, seed2 uint64) {
+ p.hi = seed1
+ p.lo = seed2
+}
+
+// binary.bigEndian.Uint64, copied to avoid dependency
+func beUint64(b []byte) uint64 {
+ _ = b[7] // bounds check hint to compiler; see golang.org/issue/14808
+ return uint64(b[7]) | uint64(b[6])<<8 | uint64(b[5])<<16 | uint64(b[4])<<24 |
+ uint64(b[3])<<32 | uint64(b[2])<<40 | uint64(b[1])<<48 | uint64(b[0])<<56
+}
+
+// binary.bigEndian.PutUint64, copied to avoid dependency
+func bePutUint64(b []byte, v uint64) {
+ _ = b[7] // early bounds check to guarantee safety of writes below
+ b[0] = byte(v >> 56)
+ b[1] = byte(v >> 48)
+ b[2] = byte(v >> 40)
+ b[3] = byte(v >> 32)
+ b[4] = byte(v >> 24)
+ b[5] = byte(v >> 16)
+ b[6] = byte(v >> 8)
+ b[7] = byte(v)
+}
+
+// MarshalBinary implements the encoding.BinaryMarshaler interface.
+func (p *PCG) MarshalBinary() ([]byte, error) {
+ b := make([]byte, 20)
+ copy(b, "pcg:")
+ bePutUint64(b[4:], p.hi)
+ bePutUint64(b[4+8:], p.lo)
+ return b, nil
+}
+
+var errUnmarshalPCG = errors.New("invalid PCG encoding")
+
+// UnmarshalBinary implements the encoding.BinaryUnmarshaler interface.
+func (p *PCG) UnmarshalBinary(data []byte) error {
+ if len(data) != 20 || string(data[:4]) != "pcg:" {
+ return errUnmarshalPCG
+ }
+ p.hi = beUint64(data[4:])
+ p.lo = beUint64(data[4+8:])
+ return nil
+}
+
+func (p *PCG) next() (hi, lo uint64) {
+ // https://github.com/imneme/pcg-cpp/blob/428802d1a5/include/pcg_random.hpp#L161
+ //
+ // Numpy's PCG multiplies by the 64-bit value cheapMul
+ // instead of the 128-bit value used here and in the official PCG code.
+ // This does not seem worthwhile, at least for Go: not having any high
+ // bits in the multiplier reduces the effect of low bits on the highest bits,
+ // and it only saves 1 multiply out of 3.
+ // (On 32-bit systems, it saves 1 out of 6, since Mul64 is doing 4.)
+ const (
+ mulHi = 2549297995355413924
+ mulLo = 4865540595714422341
+ incHi = 6364136223846793005
+ incLo = 1442695040888963407
+ )
+
+ // state = state * mul + inc
+ hi, lo = bits.Mul64(p.lo, mulLo)
+ hi += p.hi*mulLo + p.lo*mulHi
+ lo, c := bits.Add64(lo, incLo, 0)
+ hi, _ = bits.Add64(hi, incHi, c)
+ p.lo = lo
+ p.hi = hi
+ return hi, lo
+}
+
+// Uint64 return a uniformly-distributed random uint64 value.
+func (p *PCG) Uint64() uint64 {
+ hi, lo := p.next()
+
+ // XSL-RR would be
+ // hi, lo := p.next()
+ // return bits.RotateLeft64(lo^hi, -int(hi>>58))
+ // but Numpy uses DXSM and O'Neill suggests doing the same.
+ // See https://github.com/golang/go/issues/21835#issuecomment-739065688
+ // and following comments.
+
+ // DXSM "double xorshift multiply"
+ // https://github.com/imneme/pcg-cpp/blob/428802d1a5/include/pcg_random.hpp#L1015
+
+ // https://github.com/imneme/pcg-cpp/blob/428802d1a5/include/pcg_random.hpp#L176
+ const cheapMul = 0xda942042e4dd58b5
+ hi ^= hi >> 32
+ hi *= cheapMul
+ hi ^= hi >> 48
+ hi *= (lo | 1)
+ return hi
+}
diff --git a/contrib/go/_std_1.22/src/math/rand/v2/rand.go b/contrib/go/_std_1.22/src/math/rand/v2/rand.go
new file mode 100644
index 0000000000..f490408472
--- /dev/null
+++ b/contrib/go/_std_1.22/src/math/rand/v2/rand.go
@@ -0,0 +1,363 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package rand implements pseudo-random number generators suitable for tasks
+// such as simulation, but it should not be used for security-sensitive work.
+//
+// Random numbers are generated by a [Source], usually wrapped in a [Rand].
+// Both types should be used by a single goroutine at a time: sharing among
+// multiple goroutines requires some kind of synchronization.
+//
+// Top-level functions, such as [Float64] and [Int],
+// are safe for concurrent use by multiple goroutines.
+//
+// This package's outputs might be easily predictable regardless of how it's
+// seeded. For random numbers suitable for security-sensitive work, see the
+// crypto/rand package.
+package rand
+
+import (
+ "math/bits"
+ _ "unsafe" // for go:linkname
+)
+
+// A Source is a source of uniformly-distributed
+// pseudo-random uint64 values in the range [0, 1<<64).
+//
+// A Source is not safe for concurrent use by multiple goroutines.
+type Source interface {
+ Uint64() uint64
+}
+
+// A Rand is a source of random numbers.
+type Rand struct {
+ src Source
+}
+
+// New returns a new Rand that uses random values from src
+// to generate other random values.
+func New(src Source) *Rand {
+ return &Rand{src: src}
+}
+
+// Int64 returns a non-negative pseudo-random 63-bit integer as an int64.
+func (r *Rand) Int64() int64 { return int64(r.src.Uint64() &^ (1 << 63)) }
+
+// Uint32 returns a pseudo-random 32-bit value as a uint32.
+func (r *Rand) Uint32() uint32 { return uint32(r.src.Uint64() >> 32) }
+
+// Uint64 returns a pseudo-random 64-bit value as a uint64.
+func (r *Rand) Uint64() uint64 { return r.src.Uint64() }
+
+// Int32 returns a non-negative pseudo-random 31-bit integer as an int32.
+func (r *Rand) Int32() int32 { return int32(r.src.Uint64() >> 33) }
+
+// Int returns a non-negative pseudo-random int.
+func (r *Rand) Int() int { return int(uint(r.src.Uint64()) << 1 >> 1) }
+
+// Int64N returns, as an int64, a non-negative pseudo-random number in the half-open interval [0,n).
+// It panics if n <= 0.
+func (r *Rand) Int64N(n int64) int64 {
+ if n <= 0 {
+ panic("invalid argument to Int64N")
+ }
+ return int64(r.uint64n(uint64(n)))
+}
+
+// Uint64N returns, as a uint64, a non-negative pseudo-random number in the half-open interval [0,n).
+// It panics if n == 0.
+func (r *Rand) Uint64N(n uint64) uint64 {
+ if n == 0 {
+ panic("invalid argument to Uint64N")
+ }
+ return r.uint64n(n)
+}
+
+// uint64n is the no-bounds-checks version of Uint64N.
+func (r *Rand) uint64n(n uint64) uint64 {
+ if is32bit && uint64(uint32(n)) == n {
+ return uint64(r.uint32n(uint32(n)))
+ }
+ if n&(n-1) == 0 { // n is power of two, can mask
+ return r.Uint64() & (n - 1)
+ }
+
+ // Suppose we have a uint64 x uniform in the range [0,2⁶⁴)
+ // and want to reduce it to the range [0,n) preserving exact uniformity.
+ // We can simulate a scaling arbitrary precision x * (n/2⁶⁴) by
+ // the high bits of a double-width multiply of x*n, meaning (x*n)/2⁶⁴.
+ // Since there are 2⁶⁴ possible inputs x and only n possible outputs,
+ // the output is necessarily biased if n does not divide 2⁶⁴.
+ // In general (x*n)/2⁶⁴ = k for x*n in [k*2⁶⁴,(k+1)*2⁶⁴).
+ // There are either floor(2⁶⁴/n) or ceil(2⁶⁴/n) possible products
+ // in that range, depending on k.
+ // But suppose we reject the sample and try again when
+ // x*n is in [k*2⁶⁴, k*2⁶⁴+(2⁶⁴%n)), meaning rejecting fewer than n possible
+ // outcomes out of the 2⁶⁴.
+ // Now there are exactly floor(2⁶⁴/n) possible ways to produce
+ // each output value k, so we've restored uniformity.
+ // To get valid uint64 math, 2⁶⁴ % n = (2⁶⁴ - n) % n = -n % n,
+ // so the direct implementation of this algorithm would be:
+ //
+ // hi, lo := bits.Mul64(r.Uint64(), n)
+ // thresh := -n % n
+ // for lo < thresh {
+ // hi, lo = bits.Mul64(r.Uint64(), n)
+ // }
+ //
+ // That still leaves an expensive 64-bit division that we would rather avoid.
+ // We know that thresh < n, and n is usually much less than 2⁶⁴, so we can
+ // avoid the last four lines unless lo < n.
+ //
+ // See also:
+ // https://lemire.me/blog/2016/06/27/a-fast-alternative-to-the-modulo-reduction
+ // https://lemire.me/blog/2016/06/30/fast-random-shuffling
+ hi, lo := bits.Mul64(r.Uint64(), n)
+ if lo < n {
+ thresh := -n % n
+ for lo < thresh {
+ hi, lo = bits.Mul64(r.Uint64(), n)
+ }
+ }
+ return hi
+}
+
+// uint32n is an identical computation to uint64n
+// but optimized for 32-bit systems.
+func (r *Rand) uint32n(n uint32) uint32 {
+ if n&(n-1) == 0 { // n is power of two, can mask
+ return uint32(r.Uint64()) & (n - 1)
+ }
+ // On 64-bit systems we still use the uint64 code below because
+ // the probability of a random uint64 lo being < a uint32 n is near zero,
+ // meaning the unbiasing loop almost never runs.
+ // On 32-bit systems, here we need to implement that same logic in 32-bit math,
+ // both to preserve the exact output sequence observed on 64-bit machines
+ // and to preserve the optimization that the unbiasing loop almost never runs.
+ //
+ // We want to compute
+ // hi, lo := bits.Mul64(r.Uint64(), n)
+ // In terms of 32-bit halves, this is:
+ // x1:x0 := r.Uint64()
+ // 0:hi, lo1:lo0 := bits.Mul64(x1:x0, 0:n)
+ // Writing out the multiplication in terms of bits.Mul32 allows
+ // using direct hardware instructions and avoiding
+ // the computations involving these zeros.
+ x := r.Uint64()
+ lo1a, lo0 := bits.Mul32(uint32(x), n)
+ hi, lo1b := bits.Mul32(uint32(x>>32), n)
+ lo1, c := bits.Add32(lo1a, lo1b, 0)
+ hi += c
+ if lo1 == 0 && lo0 < uint32(n) {
+ n64 := uint64(n)
+ thresh := uint32(-n64 % n64)
+ for lo1 == 0 && lo0 < thresh {
+ x := r.Uint64()
+ lo1a, lo0 = bits.Mul32(uint32(x), n)
+ hi, lo1b = bits.Mul32(uint32(x>>32), n)
+ lo1, c = bits.Add32(lo1a, lo1b, 0)
+ hi += c
+ }
+ }
+ return hi
+}
+
+// Int32N returns, as an int32, a non-negative pseudo-random number in the half-open interval [0,n).
+// It panics if n <= 0.
+func (r *Rand) Int32N(n int32) int32 {
+ if n <= 0 {
+ panic("invalid argument to Int32N")
+ }
+ return int32(r.uint64n(uint64(n)))
+}
+
+// Uint32N returns, as a uint32, a non-negative pseudo-random number in the half-open interval [0,n).
+// It panics if n == 0.
+func (r *Rand) Uint32N(n uint32) uint32 {
+ if n == 0 {
+ panic("invalid argument to Uint32N")
+ }
+ return uint32(r.uint64n(uint64(n)))
+}
+
+const is32bit = ^uint(0)>>32 == 0
+
+// IntN returns, as an int, a non-negative pseudo-random number in the half-open interval [0,n).
+// It panics if n <= 0.
+func (r *Rand) IntN(n int) int {
+ if n <= 0 {
+ panic("invalid argument to IntN")
+ }
+ return int(r.uint64n(uint64(n)))
+}
+
+// UintN returns, as a uint, a non-negative pseudo-random number in the half-open interval [0,n).
+// It panics if n == 0.
+func (r *Rand) UintN(n uint) uint {
+ if n == 0 {
+ panic("invalid argument to UintN")
+ }
+ return uint(r.uint64n(uint64(n)))
+}
+
+// Float64 returns, as a float64, a pseudo-random number in the half-open interval [0.0,1.0).
+func (r *Rand) Float64() float64 {
+ // There are exactly 1<<53 float64s in [0,1). Use Intn(1<<53) / (1<<53).
+ return float64(r.Uint64()<<11>>11) / (1 << 53)
+}
+
+// Float32 returns, as a float32, a pseudo-random number in the half-open interval [0.0,1.0).
+func (r *Rand) Float32() float32 {
+ // There are exactly 1<<24 float32s in [0,1). Use Intn(1<<24) / (1<<24).
+ return float32(r.Uint32()<<8>>8) / (1 << 24)
+}
+
+// Perm returns, as a slice of n ints, a pseudo-random permutation of the integers
+// in the half-open interval [0,n).
+func (r *Rand) Perm(n int) []int {
+ p := make([]int, n)
+ for i := range p {
+ p[i] = i
+ }
+ r.Shuffle(len(p), func(i, j int) { p[i], p[j] = p[j], p[i] })
+ return p
+}
+
+// Shuffle pseudo-randomizes the order of elements.
+// n is the number of elements. Shuffle panics if n < 0.
+// swap swaps the elements with indexes i and j.
+func (r *Rand) Shuffle(n int, swap func(i, j int)) {
+ if n < 0 {
+ panic("invalid argument to Shuffle")
+ }
+
+ // Fisher-Yates shuffle: https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle
+ // Shuffle really ought not be called with n that doesn't fit in 32 bits.
+ // Not only will it take a very long time, but with 2³¹! possible permutations,
+ // there's no way that any PRNG can have a big enough internal state to
+ // generate even a minuscule percentage of the possible permutations.
+ // Nevertheless, the right API signature accepts an int n, so handle it as best we can.
+ for i := n - 1; i > 0; i-- {
+ j := int(r.uint64n(uint64(i + 1)))
+ swap(i, j)
+ }
+}
+
+/*
+ * Top-level convenience functions
+ */
+
+// globalRand is the source of random numbers for the top-level
+// convenience functions.
+var globalRand = &Rand{src: &runtimeSource{}}
+
+//go:linkname runtime_rand runtime.rand
+func runtime_rand() uint64
+
+// runtimeSource is a Source that uses the runtime fastrand functions.
+type runtimeSource struct{}
+
+func (*runtimeSource) Uint64() uint64 {
+ return runtime_rand()
+}
+
+// Int64 returns a non-negative pseudo-random 63-bit integer as an int64
+// from the default Source.
+func Int64() int64 { return globalRand.Int64() }
+
+// Uint32 returns a pseudo-random 32-bit value as a uint32
+// from the default Source.
+func Uint32() uint32 { return globalRand.Uint32() }
+
+// Uint64N returns, as a uint64, a pseudo-random number in the half-open interval [0,n)
+// from the default Source.
+// It panics if n <= 0.
+func Uint64N(n uint64) uint64 { return globalRand.Uint64N(n) }
+
+// Uint32N returns, as a uint32, a pseudo-random number in the half-open interval [0,n)
+// from the default Source.
+// It panics if n <= 0.
+func Uint32N(n uint32) uint32 { return globalRand.Uint32N(n) }
+
+// Uint64 returns a pseudo-random 64-bit value as a uint64
+// from the default Source.
+func Uint64() uint64 { return globalRand.Uint64() }
+
+// Int32 returns a non-negative pseudo-random 31-bit integer as an int32
+// from the default Source.
+func Int32() int32 { return globalRand.Int32() }
+
+// Int returns a non-negative pseudo-random int from the default Source.
+func Int() int { return globalRand.Int() }
+
+// Int64N returns, as an int64, a pseudo-random number in the half-open interval [0,n)
+// from the default Source.
+// It panics if n <= 0.
+func Int64N(n int64) int64 { return globalRand.Int64N(n) }
+
+// Int32N returns, as an int32, a pseudo-random number in the half-open interval [0,n)
+// from the default Source.
+// It panics if n <= 0.
+func Int32N(n int32) int32 { return globalRand.Int32N(n) }
+
+// IntN returns, as an int, a pseudo-random number in the half-open interval [0,n)
+// from the default Source.
+// It panics if n <= 0.
+func IntN(n int) int { return globalRand.IntN(n) }
+
+// UintN returns, as a uint, a pseudo-random number in the half-open interval [0,n)
+// from the default Source.
+// It panics if n <= 0.
+func UintN(n uint) uint { return globalRand.UintN(n) }
+
+// N returns a pseudo-random number in the half-open interval [0,n) from the default Source.
+// The type parameter Int can be any integer type.
+// It panics if n <= 0.
+func N[Int intType](n Int) Int {
+ if n <= 0 {
+ panic("invalid argument to N")
+ }
+ return Int(globalRand.uint64n(uint64(n)))
+}
+
+type intType interface {
+ ~int | ~int8 | ~int16 | ~int32 | ~int64 |
+ ~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr
+}
+
+// Float64 returns, as a float64, a pseudo-random number in the half-open interval [0.0,1.0)
+// from the default Source.
+func Float64() float64 { return globalRand.Float64() }
+
+// Float32 returns, as a float32, a pseudo-random number in the half-open interval [0.0,1.0)
+// from the default Source.
+func Float32() float32 { return globalRand.Float32() }
+
+// Perm returns, as a slice of n ints, a pseudo-random permutation of the integers
+// in the half-open interval [0,n) from the default Source.
+func Perm(n int) []int { return globalRand.Perm(n) }
+
+// Shuffle pseudo-randomizes the order of elements using the default Source.
+// n is the number of elements. Shuffle panics if n < 0.
+// swap swaps the elements with indexes i and j.
+func Shuffle(n int, swap func(i, j int)) { globalRand.Shuffle(n, swap) }
+
+// NormFloat64 returns a normally distributed float64 in the range
+// [-math.MaxFloat64, +math.MaxFloat64] with
+// standard normal distribution (mean = 0, stddev = 1)
+// from the default Source.
+// To produce a different normal distribution, callers can
+// adjust the output using:
+//
+// sample = NormFloat64() * desiredStdDev + desiredMean
+func NormFloat64() float64 { return globalRand.NormFloat64() }
+
+// ExpFloat64 returns an exponentially distributed float64 in the range
+// (0, +math.MaxFloat64] with an exponential distribution whose rate parameter
+// (lambda) is 1 and whose mean is 1/lambda (1) from the default Source.
+// To produce a distribution with a different rate parameter,
+// callers can adjust the output using:
+//
+// sample = ExpFloat64() / desiredRateParameter
+func ExpFloat64() float64 { return globalRand.ExpFloat64() }
diff --git a/contrib/go/_std_1.22/src/math/rand/v2/ya.make b/contrib/go/_std_1.22/src/math/rand/v2/ya.make
new file mode 100644
index 0000000000..709d17ea4d
--- /dev/null
+++ b/contrib/go/_std_1.22/src/math/rand/v2/ya.make
@@ -0,0 +1,14 @@
+SUBSCRIBER(g:contrib)
+
+GO_LIBRARY()
+IF (TRUE)
+ SRCS(
+ chacha8.go
+ exp.go
+ normal.go
+ pcg.go
+ rand.go
+ zipf.go
+ )
+ENDIF()
+END()
diff --git a/contrib/go/_std_1.22/src/math/rand/v2/zipf.go b/contrib/go/_std_1.22/src/math/rand/v2/zipf.go
new file mode 100644
index 0000000000..f04c814eb7
--- /dev/null
+++ b/contrib/go/_std_1.22/src/math/rand/v2/zipf.go
@@ -0,0 +1,77 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// W.Hormann, G.Derflinger:
+// "Rejection-Inversion to Generate Variates
+// from Monotone Discrete Distributions"
+// http://eeyore.wu-wien.ac.at/papers/96-04-04.wh-der.ps.gz
+
+package rand
+
+import "math"
+
+// A Zipf generates Zipf distributed variates.
+type Zipf struct {
+ r *Rand
+ imax float64
+ v float64
+ q float64
+ s float64
+ oneminusQ float64
+ oneminusQinv float64
+ hxm float64
+ hx0minusHxm float64
+}
+
+func (z *Zipf) h(x float64) float64 {
+ return math.Exp(z.oneminusQ*math.Log(z.v+x)) * z.oneminusQinv
+}
+
+func (z *Zipf) hinv(x float64) float64 {
+ return math.Exp(z.oneminusQinv*math.Log(z.oneminusQ*x)) - z.v
+}
+
+// NewZipf returns a Zipf variate generator.
+// The generator generates values k ∈ [0, imax]
+// such that P(k) is proportional to (v + k) ** (-s).
+// Requirements: s > 1 and v >= 1.
+func NewZipf(r *Rand, s float64, v float64, imax uint64) *Zipf {
+ z := new(Zipf)
+ if s <= 1.0 || v < 1 {
+ return nil
+ }
+ z.r = r
+ z.imax = float64(imax)
+ z.v = v
+ z.q = s
+ z.oneminusQ = 1.0 - z.q
+ z.oneminusQinv = 1.0 / z.oneminusQ
+ z.hxm = z.h(z.imax + 0.5)
+ z.hx0minusHxm = z.h(0.5) - math.Exp(math.Log(z.v)*(-z.q)) - z.hxm
+ z.s = 1 - z.hinv(z.h(1.5)-math.Exp(-z.q*math.Log(z.v+1.0)))
+ return z
+}
+
+// Uint64 returns a value drawn from the Zipf distribution described
+// by the Zipf object.
+func (z *Zipf) Uint64() uint64 {
+ if z == nil {
+ panic("rand: nil Zipf")
+ }
+ k := 0.0
+
+ for {
+ r := z.r.Float64() // r on [0,1]
+ ur := z.hxm + r*z.hx0minusHxm
+ x := z.hinv(ur)
+ k = math.Floor(x + 0.5)
+ if k-x <= z.s {
+ break
+ }
+ if ur >= z.h(k+0.5)-math.Exp(-math.Log(k+z.v)*z.q) {
+ break
+ }
+ }
+ return uint64(k)
+}