1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101
|
//===----------------------------------------------------------------------===//
//
// This source file is part of the SwiftNIO open source project
//
// Copyright (c) 2021 Apple Inc. and the SwiftNIO project authors
// Licensed under Apache License v2.0
//
// See LICENSE.txt for license information
// See CONTRIBUTORS.txt for the list of SwiftNIO project authors
//
// SPDX-License-Identifier: Apache-2.0
//
//===----------------------------------------------------------------------===//
@usableFromInline
enum _IntegerBitPacking {}
extension _IntegerBitPacking {
@inlinable
static func packUU<Left: FixedWidthInteger & UnsignedInteger,
Right: FixedWidthInteger & UnsignedInteger,
Result: FixedWidthInteger & UnsignedInteger>(_ left: Left,
_ right: Right,
type: Result.Type = Result.self) -> Result {
assert(MemoryLayout<Left>.size + MemoryLayout<Right>.size <= MemoryLayout<Result>.size)
let resultLeft = Result(left)
let resultRight = Result(right)
let result = (resultLeft << Right.bitWidth) | resultRight
assert(result.nonzeroBitCount == left.nonzeroBitCount + right.nonzeroBitCount)
return result
}
@inlinable
static func unpackUU<Input: FixedWidthInteger & UnsignedInteger,
Left: FixedWidthInteger & UnsignedInteger,
Right: FixedWidthInteger & UnsignedInteger>(_ input: Input,
leftType: Left.Type = Left.self,
rightType: Right.Type = Right.self) -> (Left, Right) {
assert(MemoryLayout<Left>.size + MemoryLayout<Right>.size <= MemoryLayout<Input>.size)
let leftMask = Input(Left.max)
let rightMask = Input(Right.max)
let right = input & rightMask
let left = (input >> Right.bitWidth) & leftMask
assert(input.nonzeroBitCount == left.nonzeroBitCount + right.nonzeroBitCount)
return (Left(left), Right(right))
}
}
@usableFromInline
enum IntegerBitPacking {}
extension IntegerBitPacking {
@inlinable
static func packUInt32UInt16UInt8(_ left: UInt32, _ middle: UInt16, _ right: UInt8) -> UInt64 {
return _IntegerBitPacking.packUU(
_IntegerBitPacking.packUU(right, middle, type: UInt32.self),
left
)
}
@inlinable
static func unpackUInt32UInt16UInt8(_ value: UInt64) -> (UInt32, UInt16, UInt8) {
let leftRight = _IntegerBitPacking.unpackUU(value, leftType: UInt32.self, rightType: UInt32.self)
let left = _IntegerBitPacking.unpackUU(leftRight.0, leftType: UInt8.self, rightType: UInt16.self)
return (leftRight.1, left.1, left.0)
}
@inlinable
static func packUInt8UInt8(_ left: UInt8, _ right: UInt8) -> UInt16 {
return _IntegerBitPacking.packUU(left, right)
}
@inlinable
static func unpackUInt8UInt8(_ value: UInt16) -> (UInt8, UInt8) {
return _IntegerBitPacking.unpackUU(value)
}
@inlinable
static func packUInt16UInt8(_ left: UInt16, _ right: UInt8) -> UInt32 {
return _IntegerBitPacking.packUU(left, right)
}
@inlinable
static func unpackUInt16UInt8(_ value: UInt32) -> (UInt16, UInt8) {
return _IntegerBitPacking.unpackUU(value)
}
@inlinable
static func packUInt32CInt(_ left: UInt32, _ right: CInt) -> UInt64 {
return _IntegerBitPacking.packUU(left, UInt32(truncatingIfNeeded: right))
}
@inlinable
static func unpackUInt32CInt(_ value: UInt64) -> (UInt32, CInt) {
let unpacked = _IntegerBitPacking.unpackUU(value, leftType: UInt32.self, rightType: UInt32.self)
return (unpacked.0, CInt(truncatingIfNeeded: unpacked.1))
}
}
|