hashtable.c (465B)
1
2 #include "libsheepyObject.h"
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4 u32 ilog2Hashtable(u32 value);
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6 u32 ilog2Hashtable(u32 value) {
7 //u32 n = (__builtin_clz(value) ^ 31) + 1;
8 if (!value) return 4;
9 // compute log2 of value
10 u32 n;
11 asm ("bsrl %1, %0" : "=r" (n) : "r" (value));
12 n++;
13 // keep size at 16 for values under 17
14 if (n <= 4) n = 4;
15 // if value is a power of 2, keep the size down
16 else if ((value & (value-1)) == 0) n--;
17 /*else if (value == (1<<(n-1))) n--;*/
18 return n;
19 }
20