github.com/apache/arrow/go/v7@v7.0.1/parquet/internal/bmi/bitmap_bmi2_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 bmi
    20  
    21  import "unsafe"
    22  
    23  //go:noescape
    24  func _extract_bits(bitmap, selectBitmap uint64) (res uint64)
    25  
    26  // extractBitsBMI2 uses BMI2 to call the pext instruction, Parallel Bits Extract
    27  // in order to quickly and efficiently extract the bits selected in a parallel
    28  // fashion. See the definition of the PEXT instruction for x86/x86-64 cpus
    29  func extractBitsBMI2(bitmap, selectBitmap uint64) uint64 {
    30  	return _extract_bits(bitmap, selectBitmap)
    31  }
    32  
    33  //go:noescape
    34  func _levels_to_bitmap(levels unsafe.Pointer, numLevels int, rhs int16) (res uint64)
    35  
    36  // greaterThanBitmapBMI2 builds a bitmap where each set bit indicates the corresponding level
    37  // is greater than the rhs value.
    38  func greaterThanBitmapBMI2(levels []int16, rhs int16) uint64 {
    39  	if len(levels) == 0 {
    40  		return 0
    41  	}
    42  
    43  	var (
    44  		p1 = unsafe.Pointer(&levels[0])
    45  		p2 = len(levels)
    46  		p3 = rhs
    47  	)
    48  
    49  	return _levels_to_bitmap(p1, p2, p3)
    50  }