1 // Copyright 2017 The etcd Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 package cpuutil 16 17 import ( 18 "encoding/binary" 19 "unsafe" 20 ) 21 22 const intWidth int = int(unsafe.Sizeof(0)) 23 24 var byteOrder binary.ByteOrder 25 26 // ByteOrder returns the byte order for the CPU's native endianness. 27 func ByteOrder() binary.ByteOrder { return byteOrder } 28 29 func init() { 30 i := int(0x1) 31 if v := (*[intWidth]byte)(unsafe.Pointer(&i)); v[0] == 0 { 32 byteOrder = binary.BigEndian 33 } else { 34 byteOrder = binary.LittleEndian 35 } 36 } 37