From b22d6cc592e5488619a7d3d7875d360465f714d3 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Mon, 12 Dec 2005 22:42:58 +0000
Subject: [PATCH] (struct irand_state, irand_init, irand32, irand_mod): Move to
 shred.c.

---
 src/rand-isaac.c | 60 ------------------------------------------------
 1 file changed, 60 deletions(-)

diff --git a/src/rand-isaac.c b/src/rand-isaac.c
index 4bd99d2551..3fc6b62fa8 100644
--- a/src/rand-isaac.c
+++ b/src/rand-isaac.c
@@ -333,63 +333,3 @@ isaac_seed (struct isaac_state *s)
 
   isaac_seed_finish (s);
 }
-
-/* Single-word RNG built on top of ISAAC */
-struct irand_state
-{
-  uint32_t r[ISAAC_WORDS];
-  unsigned int numleft;
-  struct isaac_state *s;
-};
-
-static void
-irand_init (struct irand_state *r, struct isaac_state *s)
-{
-  r->numleft = 0;
-  r->s = s;
-}
-
-/*
- * We take from the end of the block deliberately, so if we need
- * only a small number of values, we choose the final ones which are
- * marginally better mixed than the initial ones.
- */
-static uint32_t
-irand32 (struct irand_state *r)
-{
-  if (!r->numleft)
-    {
-      isaac_refill (r->s, r->r);
-      r->numleft = ISAAC_WORDS;
-    }
-  return r->r[--r->numleft];
-}
-
-/*
- * Return a uniformly distributed random number between 0 and n,
- * inclusive.  Thus, the result is modulo n+1.
- *
- * Theory of operation: as x steps through every possible 32-bit number,
- * x % n takes each value at least 2^32 / n times (rounded down), but
- * the values less than 2^32 % n are taken one additional time.  Thus,
- * x % n is not perfectly uniform.  To fix this, the values of x less
- * than 2^32 % n are disallowed, and if the RNG produces one, we ask
- * for a new value.
- */
-static uint32_t
-irand_mod (struct irand_state *r, uint32_t n)
-{
-  uint32_t x;
-  uint32_t lim;
-
-  if (!++n)
-    return irand32 (r);
-
-  lim = -n % n;			/* == (2**32-n) % n == 2**32 % n */
-  do
-    {
-      x = irand32 (r);
-    }
-  while (x < lim);
-  return x % n;
-}
-- 
2.47.3