gotosocial/vendor/github.com/dolthub/swiss/bits_amd64.go
kim c06e6fb656
[performance] update go-structr and go-mutexes with memory usage improvements (#2909)
* update go-structr and go-mutexes with memory usage improvements

* bump to go-structr v0.8.4
2024-05-13 08:05:46 +00:00

51 lines
1.2 KiB
Go

// Copyright 2023 Dolthub, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//go:build amd64 && !nosimd
package swiss
import (
"math/bits"
_ "unsafe"
"github.com/dolthub/swiss/simd"
)
const (
groupSize = 16
maxAvgGroupLoad = 14
)
type bitset uint16
func metaMatchH2(m *metadata, h h2) bitset {
b := simd.MatchMetadata((*[16]int8)(m), int8(h))
return bitset(b)
}
func metaMatchEmpty(m *metadata) bitset {
b := simd.MatchMetadata((*[16]int8)(m), empty)
return bitset(b)
}
func nextMatch(b *bitset) (s uint32) {
s = uint32(bits.TrailingZeros16(uint16(*b)))
*b &= ^(1 << s) // clear bit |s|
return
}
//go:linkname fastrand runtime.fastrand
func fastrand() uint32