github.com/apache/arrow/go/v7@v7.0.1/parquet/internal/utils/bit_packing_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 (
    22  	"io"
    23  
    24  	"golang.org/x/sys/cpu"
    25  )
    26  
    27  var unpack32 func(io.Reader, []uint32, int) int
    28  
    29  func init() {
    30  	if cpu.X86.HasAVX2 {
    31  		unpack32 = unpack32Avx2
    32  	} else { // default to the pure go implementation if no avx2 available
    33  		unpack32 = unpack32Default
    34  	}
    35  }