github.com/apache/arrow/go/v10@v10.0.1/parquet/internal/bmi/bmi_arm64.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 bmi
    20  
    21  import (
    22  	"os"
    23  	"strings"
    24  )
    25  import (
    26  	"golang.org/x/sys/cpu"
    27  )
    28  
    29  func init() {
    30      // Added ability to enable extension via environment:
    31  	// ARM_ENABLE_EXT=NEON go test
    32  	if ext, ok := os.LookupEnv("ARM_ENABLE_EXT"); ok {
    33  		exts := strings.Split(ext, ",")
    34  
    35  		for _, x := range exts {
    36  			switch x {
    37  			case "NEON":
    38  				cpu.ARM64.HasASIMD = true
    39  			case "AES":
    40  				cpu.ARM64.HasAES = true
    41  			case "PMULL":
    42  				cpu.ARM64.HasPMULL = true
    43  			default:
    44  				cpu.ARM64.HasASIMD = false
    45  				cpu.ARM64.HasAES = false
    46  				cpu.ARM64.HasPMULL = false
    47  			}
    48  		}
    49  	}
    50  	if cpu.ARM64.HasASIMD {
    51  		funclist.extractBits = extractBitsNEON
    52  		funclist.gtbitmap = greaterThanBitmapNEON
    53  	} else {
    54  		funclist.extractBits = extractBitsGo
    55  		funclist.gtbitmap = greaterThanBitmapGo
    56  	}
    57  }