Платформа ЦРНП "Мирокод" для разработки проектов
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43 lines
1.5 KiB
43 lines
1.5 KiB
package numeric |
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var interleaveMagic = []uint64{ |
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0x5555555555555555, |
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0x3333333333333333, |
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0x0F0F0F0F0F0F0F0F, |
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0x00FF00FF00FF00FF, |
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0x0000FFFF0000FFFF, |
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0x00000000FFFFFFFF, |
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0xAAAAAAAAAAAAAAAA, |
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} |
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var interleaveShift = []uint{1, 2, 4, 8, 16} |
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// Interleave the first 32 bits of each uint64 |
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// apdated from org.apache.lucene.util.BitUtil |
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// which was adapted from: |
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// http://graphics.stanford.edu/~seander/bithacks.html#InterleaveBMN |
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func Interleave(v1, v2 uint64) uint64 { |
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v1 = (v1 | (v1 << interleaveShift[4])) & interleaveMagic[4] |
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v1 = (v1 | (v1 << interleaveShift[3])) & interleaveMagic[3] |
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v1 = (v1 | (v1 << interleaveShift[2])) & interleaveMagic[2] |
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v1 = (v1 | (v1 << interleaveShift[1])) & interleaveMagic[1] |
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v1 = (v1 | (v1 << interleaveShift[0])) & interleaveMagic[0] |
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v2 = (v2 | (v2 << interleaveShift[4])) & interleaveMagic[4] |
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v2 = (v2 | (v2 << interleaveShift[3])) & interleaveMagic[3] |
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v2 = (v2 | (v2 << interleaveShift[2])) & interleaveMagic[2] |
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v2 = (v2 | (v2 << interleaveShift[1])) & interleaveMagic[1] |
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v2 = (v2 | (v2 << interleaveShift[0])) & interleaveMagic[0] |
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return (v2 << 1) | v1 |
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} |
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// Deinterleave the 32-bit value starting at position 0 |
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// to get the other 32-bit value, shift it by 1 first |
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func Deinterleave(b uint64) uint64 { |
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b &= interleaveMagic[0] |
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b = (b ^ (b >> interleaveShift[0])) & interleaveMagic[1] |
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b = (b ^ (b >> interleaveShift[1])) & interleaveMagic[2] |
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b = (b ^ (b >> interleaveShift[2])) & interleaveMagic[3] |
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b = (b ^ (b >> interleaveShift[3])) & interleaveMagic[4] |
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b = (b ^ (b >> interleaveShift[4])) & interleaveMagic[5] |
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return b |
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}
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