mirror of
https://github.com/featurebasedb/featurebase.git
synced 2026-08-28 10:54:59 +00:00
68 lines
1.6 KiB
Go
68 lines
1.6 KiB
Go
// Copyright 2017 Pilosa Corp.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package roaring
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// bit population count, take from
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// https://code.google.com/p/go/issues/detail?id=4988#c11
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// credit: https://code.google.com/u/arnehormann/
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func popcntGo(x uint64) (n uint64) {
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x -= (x >> 1) & 0x5555555555555555
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x = (x>>2)&0x3333333333333333 + x&0x3333333333333333
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x += x >> 4
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x &= 0x0f0f0f0f0f0f0f0f
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x *= 0x0101010101010101
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return x >> 56
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}
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func popcntSliceGo(s []uint64) uint64 {
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cnt := uint64(0)
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for _, x := range s {
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cnt += popcntGo(x)
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}
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return cnt
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}
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func popcntMaskSliceGo(s, m []uint64) uint64 {
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cnt := uint64(0)
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for i := range s {
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cnt += popcntGo(s[i] &^ m[i])
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}
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return cnt
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}
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func popcntAndSliceGo(s, m []uint64) uint64 {
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cnt := uint64(0)
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for i := range s {
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cnt += popcntGo(s[i] & m[i])
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}
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return cnt
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}
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func popcntOrSliceGo(s, m []uint64) uint64 {
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cnt := uint64(0)
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for i := range s {
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cnt += popcntGo(s[i] | m[i])
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}
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return cnt
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}
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func popcntXorSliceGo(s, m []uint64) uint64 {
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cnt := uint64(0)
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for i := range s {
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cnt += popcntGo(s[i] ^ m[i])
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}
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return cnt
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}
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