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Diffstat (limited to 'examples/redis-unstable/src/rand.c')
| -rw-r--r-- | examples/redis-unstable/src/rand.c | 93 |
1 files changed, 0 insertions, 93 deletions
diff --git a/examples/redis-unstable/src/rand.c b/examples/redis-unstable/src/rand.c deleted file mode 100644 index 6256c3b..0000000 --- a/examples/redis-unstable/src/rand.c +++ /dev/null @@ -1,93 +0,0 @@ -/* Pseudo random number generation functions derived from the drand48() - * function obtained from pysam source code. - * - * This functions are used in order to replace the default math.random() - * Lua implementation with something having exactly the same behavior - * across different systems (by default Lua uses libc's rand() that is not - * required to implement a specific PRNG generating the same sequence - * in different systems if seeded with the same integer). - * - * The original code appears to be under the public domain. - * I modified it removing the non needed functions and all the - * 1960-style C coding stuff... - * - * ---------------------------------------------------------------------------- - * - * Copyright (c) 2010-current, Redis Ltd. - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions are met: - * - * * Redistributions of source code must retain the above copyright notice, - * this list of conditions and the following disclaimer. - * * Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * * Neither the name of Redis nor the names of its contributors may be used - * to endorse or promote products derived from this software without - * specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" - * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE - * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR - * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF - * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS - * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN - * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) - * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE - * POSSIBILITY OF SUCH DAMAGE. - */ - -#include <stdint.h> - -#define N 16 -#define MASK ((1 << (N - 1)) + (1 << (N - 1)) - 1) -#define LOW(x) ((unsigned)(x) & MASK) -#define HIGH(x) LOW((x) >> N) -#define MUL(x, y, z) { int32_t l = (long)(x) * (long)(y); \ - (z)[0] = LOW(l); (z)[1] = HIGH(l); } -#define CARRY(x, y) ((int32_t)(x) + (long)(y) > MASK) -#define ADDEQU(x, y, z) (z = CARRY(x, (y)), x = LOW(x + (y))) -#define X0 0x330E -#define X1 0xABCD -#define X2 0x1234 -#define A0 0xE66D -#define A1 0xDEEC -#define A2 0x5 -#define C 0xB -#define SET3(x, x0, x1, x2) ((x)[0] = (x0), (x)[1] = (x1), (x)[2] = (x2)) -#define SETLOW(x, y, n) SET3(x, LOW((y)[n]), LOW((y)[(n)+1]), LOW((y)[(n)+2])) -#define SEED(x0, x1, x2) (SET3(x, x0, x1, x2), SET3(a, A0, A1, A2), c = C) -#define REST(v) for (i = 0; i < 3; i++) { xsubi[i] = x[i]; x[i] = temp[i]; } \ - return (v); -#define HI_BIT (1L << (2 * N - 1)) - -static uint32_t x[3] = { X0, X1, X2 }, a[3] = { A0, A1, A2 }, c = C; -static void next(void); - -int32_t redisLrand48(void) { - next(); - return (((int32_t)x[2] << (N - 1)) + (x[1] >> 1)); -} - -void redisSrand48(int32_t seedval) { - SEED(X0, LOW(seedval), HIGH(seedval)); -} - -static void next(void) { - uint32_t p[2], q[2], r[2], carry0, carry1; - - MUL(a[0], x[0], p); - ADDEQU(p[0], c, carry0); - ADDEQU(p[1], carry0, carry1); - MUL(a[0], x[1], q); - ADDEQU(p[1], q[0], carry0); - MUL(a[1], x[0], r); - x[2] = LOW(carry0 + carry1 + CARRY(p[1], r[0]) + q[1] + r[1] + - a[0] * x[2] + a[1] * x[1] + a[2] * x[0]); - x[1] = LOW(p[1] + r[0]); - x[0] = LOW(p[0]); -} |