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lib/rand.c 497 Bytes
83d290c56   Tom Rini   SPDX: Convert all...
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  // SPDX-License-Identifier: GPL-2.0+
9acf1ca50   Michael Walle   lib: add rand() f...
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  /*
   * Simple xorshift PRNG
   *   see http://www.jstatsoft.org/v08/i14/paper
   *
   * Copyright (c) 2012 Michael Walle
   * Michael Walle <michael@walle.cc>
9acf1ca50   Michael Walle   lib: add rand() f...
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   */
  
  #include <common.h>
840ef4d43   Simon Glass   common: Move rand...
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  #include <rand.h>
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  static unsigned int y = 1U;
  
  unsigned int rand_r(unsigned int *seedp)
  {
  	*seedp ^= (*seedp << 13);
  	*seedp ^= (*seedp >> 17);
  	*seedp ^= (*seedp << 5);
  
  	return *seedp;
  }
  
  unsigned int rand(void)
  {
  	return rand_r(&y);
  }
  
  void srand(unsigned int seed)
  {
  	y = seed;
  }