From e244c93d21bcacf1a0eedefdcc3018a362274796 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Wed, 17 Apr 2024 00:13:02 +0200
Subject: Adding upstream version 0.36.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 src/isaac_rand/isaac_rand.c | 169 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 169 insertions(+)
 create mode 100644 src/isaac_rand/isaac_rand.c

(limited to 'src/isaac_rand/isaac_rand.c')

diff --git a/src/isaac_rand/isaac_rand.c b/src/isaac_rand/isaac_rand.c
new file mode 100644
index 0000000..c9220e0
--- /dev/null
+++ b/src/isaac_rand/isaac_rand.c
@@ -0,0 +1,169 @@
+/*
+------------------------------------------------------------------------------
+rand.c: By Bob Jenkins.  My random number generator, ISAAC.  Public Domain.
+MODIFIED:
+  960327: Creation (addition of randinit, really)
+  970719: use context, not global variables, for internal state
+  980324: added main (ifdef'ed out), also rearranged randinit()
+  010626: Note that this is public domain
+------------------------------------------------------------------------------
+*/
+#ifndef STANDARD
+#include "isaac_standard.h"
+#endif
+#ifndef RAND
+#include "isaac_rand.h"
+#endif
+
+
+#define ind(mm,x)  (*(ub4 *)((ub1 *)(mm) + ((x) & ((RANDSIZ-1)<<2))))
+#define rngstep(mix,a,b,mm,m,m2,r,x) \
+{ \
+  x = *m;  \
+  a = (a^(mix)) + *(m2++); \
+  *(m++) = y = ind(mm,x) + a + b; \
+  *(r++) = b = ind(mm,y>>RANDSIZL) + x; \
+}
+
+void     isaac(ctx)
+randctx *ctx;
+{
+   register ub4 a,b,x,y,*m,*mm,*m2,*r,*mend;
+   mm=ctx->randmem; 
+   r=ctx->randrsl;
+   a = ctx->randa; 
+   b = ctx->randb + (++ctx->randc);
+   for (m = mm, mend = m2 = m+(RANDSIZ/2); m<mend; )
+   {
+      rngstep( a<<13, a, b, mm, m, m2, r, x);
+      rngstep( a>>6 , a, b, mm, m, m2, r, x);
+      rngstep( a<<2 , a, b, mm, m, m2, r, x);
+      rngstep( a>>16, a, b, mm, m, m2, r, x);
+   }
+   for (m2 = mm; m2<mend; )
+   {
+      rngstep( a<<13, a, b, mm, m, m2, r, x);
+      rngstep( a>>6 , a, b, mm, m, m2, r, x);
+      rngstep( a<<2 , a, b, mm, m, m2, r, x);
+      rngstep( a>>16, a, b, mm, m, m2, r, x);
+   }
+   ctx->randb = b; ctx->randa = a;
+}
+
+
+#define mix(a,b,c,d,e,f,g,h) \
+{ \
+   a^=b<<11; d+=a; b+=c; \
+   b^=c>>2;  e+=b; c+=d; \
+   c^=d<<8;  f+=c; d+=e; \
+   d^=e>>16; g+=d; e+=f; \
+   e^=f<<10; h+=e; f+=g; \
+   f^=g>>4;  a+=f; g+=h; \
+   g^=h<<8;  b+=g; h+=a; \
+   h^=a>>9;  c+=h; a+=b; \
+}
+
+/* if (flag==TRUE), then use the contents of randrsl[] to initialize mm[]. */
+void randinit(ctx, flag)
+randctx *ctx;
+word     flag;
+{
+   word i;
+   ub4 a,b,c,d,e,f,g,h;
+   ub4 *m,*r;
+   ctx->randa = ctx->randb = ctx->randc = 0;
+   m=ctx->randmem;
+   r=ctx->randrsl;
+   a=b=c=d=e=f=g=h=0x9e3779b9;  /* the golden ratio */
+
+   for (i=0; i<4; ++i)          /* scramble it */
+   {
+     mix(a,b,c,d,e,f,g,h);
+   }
+
+   if (flag) 
+   {
+     /* initialize using the contents of r[] as the seed */
+     for (i=0; i<RANDSIZ; i+=8)
+     {
+       a+=r[i  ]; 
+       b+=r[i+1];
+       c+=r[i+2]; 
+       d+=r[i+3];
+       e+=r[i+4]; 
+       f+=r[i+5]; 
+       g+=r[i+6]; 
+       h+=r[i+7];
+       mix(a,b,c,d,e,f,g,h);
+       m[i  ]=a; 
+       m[i+1]=b; 
+       m[i+2]=c; 
+       m[i+3]=d;
+       m[i+4]=e; 
+       m[i+5]=f; 
+       m[i+6]=g; 
+       m[i+7]=h;
+     }
+     /* do a second pass to make all of the seed affect all of m */
+     for (i=0; i<RANDSIZ; i+=8)
+     {
+       a+=m[i  ]; 
+       b+=m[i+1]; 
+       c+=m[i+2]; 
+       d+=m[i+3];
+       e+=m[i+4]; 
+       f+=m[i+5]; 
+       g+=m[i+6]; 
+       h+=m[i+7];
+       mix(a,b,c,d,e,f,g,h);
+       m[i  ]=a; 
+       m[i+1]=b; 
+       m[i+2]=c; 
+       m[i+3]=d;
+       m[i+4]=e; 
+       m[i+5]=f; 
+       m[i+6]=g; 
+       m[i+7]=h;
+     }
+   }
+   else
+   {
+     /* fill in m[] with messy stuff */
+     for (i=0; i<RANDSIZ; i+=8)
+     {
+       mix(a,b,c,d,e,f,g,h);
+       m[i  ]=a; 
+       m[i+1]=b; 
+       m[i+2]=c; 
+       m[i+3]=d;
+       m[i+4]=e; 
+       m[i+5]=f; 
+       m[i+6]=g; 
+       m[i+7]=h;
+     }
+   }
+
+   isaac(ctx);            /* fill in the first set of results */
+   ctx->randcnt=RANDSIZ;  /* prepare to use the first set of results */
+}
+
+
+#ifdef NEVER
+int main()
+{
+  ub4 i,j;
+  randctx ctx;
+  ctx.randa=ctx.randb=ctx.randc=(ub4)0;
+  for (i=0; i<256; ++i) ctx.randrsl[i]=(ub4)0;
+  randinit(&ctx, TRUE);
+  for (i=0; i<2; ++i)
+  {
+    isaac(&ctx);
+    for (j=0; j<256; ++j)
+    {
+      printf("%.8lx",ctx.randrsl[j]);
+      if ((j&7)==7) printf("\n");
+    }
+  }
+}
+#endif
-- 
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