19 lines
459 B
C
19 lines
459 B
C
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#include <stdlib.h>
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/* 2^31 + 2^29 - 2^25 + 2^22 - 2^19 - 2^16 + 1 */
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#define GOLDEN_RATIO_PRIME_32 0x9e370001UL
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/* *
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* hash32 - generate a hash value in the range [0, 2^@bits - 1]
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* @val: the input value
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* @bits: the number of bits in a return value
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*
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* High bits are more random, so we use them.
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* */
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uint32_t
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hash32(uint32_t val, unsigned int bits) {
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uint32_t hash = val * GOLDEN_RATIO_PRIME_32;
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return (hash >> (32 - bits));
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}
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