50 lines
1.1 KiB
C
50 lines
1.1 KiB
C
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#ifndef _MINIX_HASH_H
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#define _MINIX_HASH_H 1
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#include <stdint.h>
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/* This code is taken from:
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* lookup3.c, by Bob Jenkins, May 2006, Public Domain.
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* (macro names modified)
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*/
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#define hash_rot(x,k) (((x)<<(k)) | ((x)>>(32-(k))))
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#define hash_mix(a,b,c) \
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{ \
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a -= c; a ^= hash_rot(c, 4); c += b; \
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b -= a; b ^= hash_rot(a, 6); a += c; \
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c -= b; c ^= hash_rot(b, 8); b += a; \
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a -= c; a ^= hash_rot(c,16); c += b; \
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b -= a; b ^= hash_rot(a,19); a += c; \
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c -= b; c ^= hash_rot(b, 4); b += a; \
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}
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#define hash_final(a,b,c) \
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{ \
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c ^= b; c -= hash_rot(b,14); \
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a ^= c; a -= hash_rot(c,11); \
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b ^= a; b -= hash_rot(a,25); \
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c ^= b; c -= hash_rot(b,16); \
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a ^= c; a -= hash_rot(c,4); \
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b ^= a; b -= hash_rot(a,14); \
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c ^= b; c -= hash_rot(b,24); \
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}
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#define hash_i_64(a, u, v) { \
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u32_t i1 = (a), i2 = ex64lo(u), i3 = ex64hi(u); \
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hash_mix(i1, i2, i3); \
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hash_final(i1, i2, i3); \
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(v) = i3; \
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}
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#define hash_32(n, v) { \
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u32_t i1 = 0xa5a5a5a5, i2 = 0x12345678, i3 = n; \
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hash_mix(i1, i2, i3); \
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hash_final(i1, i2, i3); \
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(v) = i3; \
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}
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#endif
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