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@Danappelxx
Created July 4, 2016 19:55
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// 2.2 (xcode 7.3), built with optimizations
final class ArrayPerfTests: XCTestCase {
let source = 0..<300_000
// otherwise, compiler would be able to optimize these loops by inlining.
var map: (Int) -> String = { i in "\(i)" }
// 118 ms (15% STDEV)
func testRepeatedValue() {
measureBlock {
var array = Array(count: self.source.count, repeatedValue: "")
for i in self.source {
array[i] = self.map(i)
}
}
}
// 129 ms (22% STDEV)
func testForLoop() {
measureBlock {
var array = [String]()
array.reserveCapacity(self.source.count)
for i in self.source {
array.append(self.map(i))
}
}
}
// 116 ms (4% STDEV)
func testMap() {
measureBlock {
let array = self.source.map(self.map)
}
}
// 85 ms (5% STDEV)
func testPointer() {
measureBlock {
let pointer = UnsafeMutablePointer<String>.alloc(self.source.count)
for i in self.source {
pointer.advancedBy(i).initialize(self.map(i))
}
let array = Array(UnsafeBufferPointer(start: pointer, count: self.source.count))
}
}
}
// 3.0-preview-1 (xcode 8 beta 1), built with optimizations
final class ArrayPerfTests: XCTestCase {
let source = 0..<300_000
// otherwise, compiler would be able to optimize these loops by inlining.
var map: (Int) -> String = { i in "\(i)" }
// 120 ms (3% STDEV)
func testRepeatedValue() {
measure {
var array = Array(repeating: "", count: self.source.count)
for i in self.source {
array[i] = self.map(i)
}
}
}
// 124 ms (4% STDEV)
func testForLoop() {
measure {
var array = [String]()
array.reserveCapacity(self.source.count)
for i in self.source {
array.append(self.map(i))
}
}
}
// 122 ms (3% STDEV)
func testMap() {
measure {
let array = self.source.map(self.map)
}
}
// 79 ms (3% STDEV)
func testPointer() {
measure {
let pointer = UnsafeMutablePointer<String>.init(allocatingCapacity: self.source.count)
for i in self.source {
pointer.advanced(by: i).initialize(with: self.map(i))
}
let array = Array(UnsafeBufferPointer(start: pointer, count: self.source.count))
}
}
}
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