blob: 180c48abbf20abfef936953363c00913a5a279e9
| 1 | /* vi: set sw=4 ts=4: */ |
| 2 | /* |
| 3 | * $RANDOM support. |
| 4 | * |
| 5 | * Copyright (C) 2009 Denys Vlasenko |
| 6 | * |
| 7 | * Licensed under GPLv2, see file LICENSE in this source tree. |
| 8 | */ |
| 9 | #ifndef SHELL_RANDOM_H |
| 10 | #define SHELL_RANDOM_H 1 |
| 11 | |
| 12 | PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN |
| 13 | |
| 14 | typedef struct random_t { |
| 15 | /* Random number generators */ |
| 16 | int32_t galois_LFSR; /* Galois LFSR (fast but weak). signed! */ |
| 17 | uint32_t LCG; /* LCG (fast but weak) */ |
| 18 | } random_t; |
| 19 | |
| 20 | #define UNINITED_RANDOM_T(rnd) \ |
| 21 | ((rnd)->galois_LFSR == 0) |
| 22 | |
| 23 | #define INIT_RANDOM_T(rnd, nonzero, v) \ |
| 24 | ((rnd)->galois_LFSR = (nonzero), (rnd)->LCG = (v)) |
| 25 | |
| 26 | #define CLEAR_RANDOM_T(rnd) \ |
| 27 | ((rnd)->galois_LFSR = 0) |
| 28 | |
| 29 | uint32_t next_random(random_t *rnd) FAST_FUNC; |
| 30 | |
| 31 | POP_SAVED_FUNCTION_VISIBILITY |
| 32 | |
| 33 | #endif |
| 34 |