2 * rand.c - random number generation routines
4 * this source was part of the avr-lib library
5 * modified for SDCC/pic16 by Vangelis Rokas, 2005 <vrokas AT users.sourceforge.net>
8 * Copyright (c) 1990, 1993
9 * The Regents of the University of California. All rights reserved.
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39 * Posix rand_r function added May 1999 by Wes Peters <wes@softweyr.com>.
44 static long do_rand(unsigned long *ctx)
46 return ((*ctx = *ctx * 1103515245UL + 12345UL) % ((unsigned long)RAND_MAX + 1));
49 long rand_r(unsigned long *ctx)
51 unsigned long val = (unsigned long) *ctx;
57 static unsigned long next = 1;
61 return do_rand(&next);
64 void srand(unsigned long seed)
76 stdout = STREAM_GPSIM;
78 printf("seeding rand with 0x19610910: \n");
81 printf("generating three pseudo-random numbers:\n");
82 for (i = 0; i < 10; i++)
84 printf("next random number = %ld\n", rand());
87 printf("generating the same sequence with rand_r:\n");
89 for (i = 0; i < 10; i++)
91 printf("next random number = %ld\n", rand_r(&myseed));