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fb183076a3
function old new delta next_random 68 113 +45 change_random 103 121 +18 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
42 lines
871 B
C
42 lines
871 B
C
/* vi: set sw=4 ts=4: */
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/*
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* $RANDOM support.
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*
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* Copyright (C) 2009 Denys Vlasenko
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*
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* Licensed under GPLv2, see file LICENSE in this source tree.
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*/
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#ifndef SHELL_RANDOM_H
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#define SHELL_RANDOM_H 1
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PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
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typedef struct random_t {
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/* State of random number generators: */
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/* Galois LFSR (fast but weak) */
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int32_t galois_LFSR; /* must be signed! */
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/* LCG (fast but weak) */
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uint32_t LCG;
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/* 64-bit xorshift (fast, moderate strength) */
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uint32_t xs64_x;
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uint32_t xs64_y;
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} random_t;
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#define UNINITED_RANDOM_T(rnd) \
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((rnd)->galois_LFSR == 0)
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#define INIT_RANDOM_T(rnd, nonzero, v) \
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((rnd)->galois_LFSR = (rnd)->xs64_x = (nonzero), (rnd)->LCG = (rnd)->xs64_y = (v))
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#define CLEAR_RANDOM_T(rnd) \
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((rnd)->galois_LFSR = 0)
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uint32_t next_random(random_t *rnd) FAST_FUNC;
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POP_SAVED_FUNCTION_VISIBILITY
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#endif
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