1 /* 2 * Copyright 2021 Google Inc. All rights reserved. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #if !os(WASI) 18 import Foundation 19 #else 20 import SwiftOverlayShims 21 #endif 22 23 extension Int { 24 25 /// Moves the current int into the nearest power of two 26 /// 27 /// This is used since the UnsafeMutableRawPointer will face issues when writing/reading 28 /// if the buffer alignment exceeds that actual size of the buffer 29 var convertToPowerofTwo: Int { 30 guard self > 0 else { return 1 } 31 var n = UOffset(self) 32 33 #if arch(arm) || arch(i386) 34 let max = UInt32(Int.max) 35 #else 36 let max = UInt32.max 37 #endif 38 39 n -= 1 40 n |= n >> 1 41 n |= n >> 2 42 n |= n >> 4 43 n |= n >> 8 44 n |= n >> 16 45 if n != max { 46 n += 1 47 } 48 49 return Int(n) 50 } 51 } 52