60 |
|
hval += *d++ * tab[n&7]; |
61 |
|
return(hval); |
62 |
|
} |
63 |
+ |
|
64 |
+ |
|
65 |
+ |
static char bctab[256] = { |
66 |
+ |
0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, |
67 |
+ |
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, |
68 |
+ |
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, |
69 |
+ |
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, |
70 |
+ |
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, |
71 |
+ |
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, |
72 |
+ |
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, |
73 |
+ |
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, |
74 |
+ |
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, |
75 |
+ |
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, |
76 |
+ |
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, |
77 |
+ |
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, |
78 |
+ |
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, |
79 |
+ |
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, |
80 |
+ |
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, |
81 |
+ |
4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8, |
82 |
+ |
}; |
83 |
+ |
|
84 |
+ |
|
85 |
+ |
#define NBITS 32 |
86 |
+ |
|
87 |
+ |
#if NBITS==32 |
88 |
+ |
#define bitcount(i) (bctab[(i)>>24&0xff]+bctab[(i)>>16&0xff]+ \ |
89 |
+ |
bctab[(i)>>8&0xff]+bctab[(i)&0xff]) |
90 |
+ |
#endif |
91 |
+ |
#if NBITS==16 |
92 |
+ |
#define bitcount(i) (bctab[(i)>>8&0xff]+bctab[(i)&0xff]) |
93 |
+ |
#endif |
94 |
+ |
|
95 |
+ |
|
96 |
+ |
int |
97 |
+ |
urind(s, i) /* compute i'th index from seed s */ |
98 |
+ |
int s, i; |
99 |
+ |
{ |
100 |
+ |
register int ss, k; |
101 |
+ |
int left; |
102 |
+ |
|
103 |
+ |
ss = s*1103515245 + 12345; |
104 |
+ |
left = 0; |
105 |
+ |
for (k = i/NBITS; k--; ) { |
106 |
+ |
left += bitcount(ss); |
107 |
+ |
ss = ss*1103515245 + 12345; |
108 |
+ |
} |
109 |
+ |
for (k = i&(NBITS-1); k--; ss >>= 1) |
110 |
+ |
left += ss & 1; |
111 |
+ |
if (ss & 1) |
112 |
+ |
return(s-left-1); |
113 |
+ |
return(s-left+i); |
114 |
+ |
} |