github.com/saintwish/kv@v1.0.4/swiss/bits_amd64.go (about) 1 // From https://github.com/dolthub/swiss 2 // Copyright 2023 Dolthub, Inc. 3 // 4 // Licensed under the Apache License, Version 2.0 (the "License"); 5 // you may not use this file except in compliance with the License. 6 // You may obtain a copy of the License at 7 // 8 // http://www.apache.org/licenses/LICENSE-2.0 9 // 10 // Unless required by applicable law or agreed to in writing, software 11 // distributed under the License is distributed on an "AS IS" BASIS, 12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 // See the License for the specific language governing permissions and 14 // limitations under the License. 15 16 //go:build amd64 && !nosimd 17 18 package swiss 19 20 import ( 21 "math/bits" 22 _ "unsafe" 23 24 "github.com/saintwish/kv/swiss/simd" 25 ) 26 27 const ( 28 groupSize = 16 29 maxAvgGroupLoad = 14 30 ) 31 32 type bitset uint16 33 34 func metaMatchH2(m *metadata, h h2) bitset { 35 b := simd.MatchMetadata((*[16]int8)(m), int8(h)) 36 return bitset(b) 37 } 38 39 func metaMatchEmpty(m *metadata) bitset { 40 b := simd.MatchMetadata((*[16]int8)(m), empty) 41 return bitset(b) 42 } 43 44 func nextMatch(b *bitset) (s uint32) { 45 s = uint32(bits.TrailingZeros16(uint16(*b))) 46 *b &= ^(1 << s) // clear bit |s| 47 return 48 } 49 50 //go:linkname fastrand runtime.fastrand 51 func fastrand() uint32