github.com/apache/arrow/go/v7@v7.0.1/parquet/internal/utils/unpack_bool_amd64.go (about)

     1  // Licensed to the Apache Software Foundation (ASF) under one
     2  // or more contributor license agreements.  See the NOTICE file
     3  // distributed with this work for additional information
     4  // regarding copyright ownership.  The ASF licenses this file
     5  // to you under the Apache License, Version 2.0 (the
     6  // "License"); you may not use this file except in compliance
     7  // with the License.  You may obtain a copy of the License at
     8  //
     9  // http://www.apache.org/licenses/LICENSE-2.0
    10  //
    11  // Unless required by applicable law or agreed to in writing, software
    12  // distributed under the License is distributed on an "AS IS" BASIS,
    13  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14  // See the License for the specific language governing permissions and
    15  // limitations under the License.
    16  
    17  // +build !noasm
    18  
    19  package utils
    20  
    21  import "golang.org/x/sys/cpu"
    22  
    23  var byteToBoolFunc func([]byte, []bool)
    24  
    25  func init() {
    26  	// if the cpu supports AVX2 or SSE4 then use SIMD to accelerate the conversion
    27  	// of a bitmap to a slice of bools in an optimized fashion, otherwise fallback
    28  	// to the pure go implementation
    29  	if cpu.X86.HasAVX2 {
    30  		byteToBoolFunc = bytesToBoolsAVX2
    31  	} else if cpu.X86.HasSSE42 {
    32  		byteToBoolFunc = bytesToBoolsSSE4
    33  	} else {
    34  		byteToBoolFunc = bytesToBoolsGo
    35  	}
    36  }
    37  
    38  // BytesToBools efficiently populates a slice of booleans from an input bitmap
    39  func BytesToBools(in []byte, out []bool) {
    40  	byteToBoolFunc(in, out)
    41  }