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9eb2743dd9
A Dictionary.removeValue(forKey:) benchmark regressed 35% because recent changes in this PR caused an _UnsafeBitMap member to not be inlined in its implementation. (This was probably triggered by moving a method from Dictionary._Variant to _NativeDictionary.) Add @inline(__always) to _UnsafeBitMap members. While we’re at it, make _UnsafeBitMap @usableFromInline. It’s only public for testing purposes.
88 lines
2.5 KiB
Swift
88 lines
2.5 KiB
Swift
//===----------------------------------------------------------------------===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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/// A wrapper around a bitmap storage with room for at least `bitCount` bits.
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@_fixed_layout
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@usableFromInline // @testable
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internal struct _UnsafeBitMap {
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@usableFromInline
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internal let values: UnsafeMutablePointer<UInt>
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@usableFromInline
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internal let bitCount: Int
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@inlinable
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@inline(__always)
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internal static func wordIndex(_ i: Int) -> Int {
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// Note: We perform the operation on UInts to get faster unsigned math
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// (shifts).
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return Int(bitPattern: UInt(bitPattern: i) / UInt(UInt.bitWidth))
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}
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@inlinable
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@inline(__always)
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internal static func bitIndex(_ i: Int) -> UInt {
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// Note: We perform the operation on UInts to get faster unsigned math
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// (shifts).
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return UInt(bitPattern: i) % UInt(UInt.bitWidth)
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}
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@inlinable
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@inline(__always)
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internal static func sizeInWords(forSizeInBits bitCount: Int) -> Int {
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return (bitCount + Int.bitWidth - 1) / Int.bitWidth
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}
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@inlinable
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@inline(__always)
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internal init(storage: UnsafeMutablePointer<UInt>, bitCount: Int) {
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self.bitCount = bitCount
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self.values = storage
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}
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@inlinable
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internal var numberOfWords: Int {
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@inline(__always)
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get {
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return _UnsafeBitMap.sizeInWords(forSizeInBits: bitCount)
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}
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}
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@inlinable
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@inline(__always)
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internal func initializeToZero() {
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values.initialize(repeating: 0, count: numberOfWords)
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}
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@inlinable
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internal subscript(i: Int) -> Bool {
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@inline(__always)
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get {
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_sanityCheck(i < Int(bitCount) && i >= 0, "index out of bounds")
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let word = values[_UnsafeBitMap.wordIndex(i)]
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let bit = word & (1 << _UnsafeBitMap.bitIndex(i))
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return bit != 0
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}
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@inline(__always)
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nonmutating set {
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_sanityCheck(i < Int(bitCount) && i >= 0, "index out of bounds")
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let wordIdx = _UnsafeBitMap.wordIndex(i)
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let bitMask = (1 as UInt) &<< _UnsafeBitMap.bitIndex(i)
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if newValue {
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values[wordIdx] = values[wordIdx] | bitMask
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} else {
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values[wordIdx] = values[wordIdx] & ~bitMask
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}
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}
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}
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}
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