From f5c4671bfbad96bf346bd7e9a21fc4317b4959df Mon Sep 17 00:00:00 2001 From: Indrajith K L Date: Sat, 3 Dec 2022 17:00:20 +0530 Subject: Adds most of the tools --- v_windows/v/old/vlib/rand/pcg32/pcg32.v | 226 ++++++++++++++++++++++++++++++++ 1 file changed, 226 insertions(+) create mode 100644 v_windows/v/old/vlib/rand/pcg32/pcg32.v (limited to 'v_windows/v/old/vlib/rand/pcg32/pcg32.v') diff --git a/v_windows/v/old/vlib/rand/pcg32/pcg32.v b/v_windows/v/old/vlib/rand/pcg32/pcg32.v new file mode 100644 index 0000000..25a83f7 --- /dev/null +++ b/v_windows/v/old/vlib/rand/pcg32/pcg32.v @@ -0,0 +1,226 @@ +// Copyright (c) 2019-2021 Alexander Medvednikov. All rights reserved. +// Use of this source code is governed by an MIT license +// that can be found in the LICENSE file. +module pcg32 + +import rand.seed +import rand.constants + +// PCG32RNG ported from http://www.pcg-random.org/download.html, +// https://github.com/imneme/pcg-c-basic/blob/master/pcg_basic.c, and +// https://github.com/imneme/pcg-c-basic/blob/master/pcg_basic.h +pub struct PCG32RNG { +mut: + state u64 = u64(0x853c49e6748fea9b) ^ seed.time_seed_64() + inc u64 = u64(0xda3e39cb94b95bdb) ^ seed.time_seed_64() +} + +// seed seeds the PCG32RNG with 4 `u32` values. +// The first 2 represent the 64-bit initial state as `[lower 32 bits, higher 32 bits]` +// The last 2 represent the 64-bit stream/step of the PRNG. +pub fn (mut rng PCG32RNG) seed(seed_data []u32) { + if seed_data.len != 4 { + eprintln('PCG32RNG needs 4 u32s to be seeded. First two the initial state and the last two the stream/step. Both in little endian format: [lower, higher].') + exit(1) + } + init_state := u64(seed_data[0]) | (u64(seed_data[1]) << 32) + init_seq := u64(seed_data[2]) | (u64(seed_data[3]) << 32) + rng.state = u64(0) + rng.inc = (init_seq << u64(1)) | u64(1) + rng.u32() + rng.state += init_state + rng.u32() +} + +// u32 returns a pseudorandom unsigned `u32`. +[inline] +pub fn (mut rng PCG32RNG) u32() u32 { + oldstate := rng.state + rng.state = oldstate * (6364136223846793005) + rng.inc + xorshifted := u32(((oldstate >> u64(18)) ^ oldstate) >> u64(27)) + rot := u32(oldstate >> u64(59)) + return ((xorshifted >> rot) | (xorshifted << ((-rot) & u32(31)))) +} + +// u64 returns a pseudorandom 64-bit unsigned `u64`. +[inline] +pub fn (mut rng PCG32RNG) u64() u64 { + return u64(rng.u32()) | (u64(rng.u32()) << 32) +} + +// u32n returns a pseudorandom 32-bit unsigned `u32` in range `[0, max)`. +[inline] +pub fn (mut rng PCG32RNG) u32n(max u32) u32 { + if max == 0 { + eprintln('max must be positive') + exit(1) + } + // To avoid bias, we need to make the range of the RNG a multiple of + // max, which we do by dropping output less than a threshold. + threshold := (-max % max) + // Uniformity guarantees that loop below will terminate. In practice, it + // should usually terminate quickly; on average (assuming all max's are + // equally likely), 82.25% of the time, we can expect it to require just + // one iteration. In practice, max's are typically small and only a + // tiny amount of the range is eliminated. + for { + r := rng.u32() + if r >= threshold { + return (r % max) + } + } + return u32(0) +} + +// u64n returns a pseudorandom 64-bit unsigned `u64` in range `[0, max)`. +[inline] +pub fn (mut rng PCG32RNG) u64n(max u64) u64 { + if max == 0 { + eprintln('max must be positive') + exit(1) + } + threshold := (-max % max) + for { + r := rng.u64() + if r >= threshold { + return (r % max) + } + } + return u64(0) +} + +// u32_in_range returns a pseudorandom 32-bit unsigned `u32` in range `[min, max)`. +[inline] +pub fn (mut rng PCG32RNG) u32_in_range(min u32, max u32) u32 { + if max <= min { + eprintln('max must be greater than min') + exit(1) + } + return min + rng.u32n(u32(max - min)) +} + +// u64_in_range returns a pseudorandom 64-bit unsigned `u64` in range `[min, max)`. +[inline] +pub fn (mut rng PCG32RNG) u64_in_range(min u64, max u64) u64 { + if max <= min { + eprintln('max must be greater than min') + exit(1) + } + return min + rng.u64n(max - min) +} + +// int returns a 32-bit signed (possibly negative) `int`. +[inline] +pub fn (mut rng PCG32RNG) int() int { + return int(rng.u32()) +} + +// i64 returns a 64-bit signed (possibly negative) `i64`. +[inline] +pub fn (mut rng PCG32RNG) i64() i64 { + return i64(rng.u64()) +} + +// int31 returns a 31-bit positive pseudorandom `int`. +[inline] +pub fn (mut rng PCG32RNG) int31() int { + return int(rng.u32() >> 1) +} + +// int63 returns a 63-bit positive pseudorandom `i64`. +[inline] +pub fn (mut rng PCG32RNG) int63() i64 { + return i64(rng.u64() >> 1) +} + +// intn returns a 32-bit positive `int` in range `[0, max)`. +[inline] +pub fn (mut rng PCG32RNG) intn(max int) int { + if max <= 0 { + eprintln('max has to be positive.') + exit(1) + } + return int(rng.u32n(u32(max))) +} + +// i64n returns a 64-bit positive `i64` in range `[0, max)`. +[inline] +pub fn (mut rng PCG32RNG) i64n(max i64) i64 { + if max <= 0 { + eprintln('max has to be positive.') + exit(1) + } + return i64(rng.u64n(u64(max))) +} + +// int_in_range returns a 32-bit positive `int` in range `[0, max)`. +[inline] +pub fn (mut rng PCG32RNG) int_in_range(min int, max int) int { + if max <= min { + eprintln('max must be greater than min.') + exit(1) + } + return min + rng.intn(max - min) +} + +// i64_in_range returns a 64-bit positive `i64` in range `[0, max)`. +[inline] +pub fn (mut rng PCG32RNG) i64_in_range(min i64, max i64) i64 { + if max <= min { + eprintln('max must be greater than min.') + exit(1) + } + return min + rng.i64n(max - min) +} + +// f32 returns a pseudorandom `f32` value in range `[0, 1)`. +[inline] +pub fn (mut rng PCG32RNG) f32() f32 { + return f32(rng.u32()) / constants.max_u32_as_f32 +} + +// f64 returns a pseudorandom `f64` value in range `[0, 1)`. +[inline] +pub fn (mut rng PCG32RNG) f64() f64 { + return f64(rng.u64()) / constants.max_u64_as_f64 +} + +// f32n returns a pseudorandom `f32` value in range `[0, max)`. +[inline] +pub fn (mut rng PCG32RNG) f32n(max f32) f32 { + if max <= 0 { + eprintln('max has to be positive.') + exit(1) + } + return rng.f32() * max +} + +// f64n returns a pseudorandom `f64` value in range `[0, max)`. +[inline] +pub fn (mut rng PCG32RNG) f64n(max f64) f64 { + if max <= 0 { + eprintln('max has to be positive.') + exit(1) + } + return rng.f64() * max +} + +// f32_in_range returns a pseudorandom `f32` in range `[min, max)`. +[inline] +pub fn (mut rng PCG32RNG) f32_in_range(min f32, max f32) f32 { + if max <= min { + eprintln('max must be greater than min') + exit(1) + } + return min + rng.f32n(max - min) +} + +// i64_in_range returns a pseudorandom `i64` in range `[min, max)`. +[inline] +pub fn (mut rng PCG32RNG) f64_in_range(min f64, max f64) f64 { + if max <= min { + eprintln('max must be greater than min') + exit(1) + } + return min + rng.f64n(max - min) +} -- cgit v1.2.3