3 inline cell log2(cell x) {
5 #if defined(FACTOR_X86)
7 _BitScanReverse((unsigned long*)&n, x);
9 asm("bsr %1, %0;" : "=r"(n) : "r"(x));
11 #elif defined(FACTOR_AMD64)
14 _BitScanReverse64((unsigned long*)&n, x);
16 asm("bsr %1, %0;" : "=r"(n) : "r"(x));
18 #elif defined(FACTOR_PPC64)
20 n = (63 - __builtin_clzll(x));
22 #error Unsupported compiler
24 #elif defined(FACTOR_PPC32)
26 n = (31 - __builtin_clz(x));
28 #error Unsupported compiler
31 #error Unsupported CPU
36 inline cell rightmost_clear_bit(cell x) { return log2(~x & (x + 1)); }
38 inline cell rightmost_set_bit(cell x) { return log2(x & (~x + 1)); }
40 inline cell popcount(cell x) {
43 return __builtin_popcountll(x);
45 return __builtin_popcount(x);
49 uint64_t k1 = 0x5555555555555555ll;
50 uint64_t k2 = 0x3333333333333333ll;
51 uint64_t k4 = 0x0f0f0f0f0f0f0f0fll;
52 uint64_t kf = 0x0101010101010101ll;
55 uint32_t k1 = 0x55555555;
56 uint32_t k2 = 0x33333333;
57 uint32_t k4 = 0xf0f0f0f;
58 uint32_t kf = 0x1010101;
62 x = x - ((x >> 1) & k1); // put count of each 2 bits into those 2 bits
63 x = (x & k2) + ((x >> 2) & k2); // put count of each 4 bits into those 4 bits
64 x = (x + (x >> 4)) & k4; // put count of each 8 bits into those 8 bits
65 x = (x * kf) >> ks; // returns 8 most significant bits of x + (x<<8) +
66 // (x<<16) + (x<<24) + ...
72 inline bool bitmap_p(uint8_t* bitmap, cell index) {
73 cell byte = index >> 3;
75 return (bitmap[byte] & (1 << bit)) != 0;