ViewVC Help
View File | Revision Log | Show Annotations | Download File | Root Listing
root/Development/ray/src/common/urand.c
(Generate patch)

Comparing ray/src/common/urand.c (file contents):
Revision 2.9 by greg, Sun May 16 14:49:42 2004 UTC vs.
Revision 2.12 by greg, Thu Apr 21 02:52:40 2022 UTC

# Line 7 | Line 7 | static const char      RCSid[] = "$Id$";
7  
8   #include "copyright.h"
9  
10 < #include  <stdlib.h>
11 <
12 < #include  "standard.h"
10 > #include  "rterror.h"
11   #include  "random.h"
12  
13   #undef initurand
14  
15   #define  MAXORDER       (8*sizeof(unsigned short))
16  
17 < unsigned short  *urperm = NULL; /* urand() permutation */
20 < int  urmask;            /* bits used in permutation */
17 > static unsigned short  empty_tab = 0;
18  
19 + unsigned short  *urperm = &empty_tab;   /* urand() permutation */
20 + int  urmask = 0;                        /* bits used in permutation */
21 +
22 +
23 + long
24 + irandom(                        /* better than using random() % modulus */
25 +        long modulus
26 + )
27 + {
28 +        static const int        isize = sizeof(int);
29 +        static const int        lsize = sizeof(long);
30 +        static const int        llsize = sizeof(long long);
31 +
32 +        if ((lsize == 8) | (isize == 8))
33 +                return((random()*modulus)>>31);
34 +
35 +        if (llsize == 8)
36 +                return((random()*(long long)modulus)>>31);
37 +
38 +        return(random() % modulus);
39 + }
40 +
41   int
42 < initurand(size)         /* initialize urand() for size entries */
43 < int  size;
42 > initurand(                      /* initialize urand() for size entries */
43 >        int  size
44 > )
45   {
46          int  order, n;
47 <        register int  i, offset;
47 >        int  i, offset;
48  
49 <        if (urperm != NULL)
49 >        if ((urperm != NULL) & (urperm != &empty_tab))
50                  free((void *)urperm);
51          if (--size <= 0) {
52 <                urperm = NULL;
52 >                empty_tab = 0;
53 >                urperm = &empty_tab;
54                  urmask = 0;
55                  return(0);
56          }
# Line 57 | Line 78 | int  size;
78  
79  
80   int
81 < ilhash(d, n)                    /* hash a set of integer values */
82 < register int  *d;
83 < register int  n;
81 > ilhash(                         /* hash a set of integer values */
82 >        int  *d,
83 >        int  n
84 > )
85   {
86 <        static int  tab[8] = {13623,353,1637,5831,2314,3887,5832,8737};
87 <        register int  hval;
86 >        static int  tab[8] = {103699,96289,73771,65203,81119,87037,92051,98899};
87 >        int  hval;
88  
89          hval = 0;
90          while (n-- > 0)
91 <                hval += *d++ * tab[n&7];
92 <        return(hval);
91 >                hval ^= *d++ * tab[n&7];
92 >        return(hval & 0x7fffffff);
93   }

Diff Legend

– Removed lines
+ Added lines
< Changed lines (old)
> Changed lines (new)