---

yaml
---
r: 341966
b: refs/heads/rxwei-patch-1
c: 6d73ed3
h: refs/heads/master

Author: rintaro

[refs]

@@ -1015,7 +1015,7 @@ refs/tags/swift-DEVELOPMENT-SNAPSHOT-2018-08-18-a: b10b1fce14385faa6d44f6b933e95
 refs/heads/rdar-43033749-fix-batch-mode-no-diags-swift-5.0-branch: a14e64eaad30de89f0f5f0b2a782eed7ecdcb255
 refs/heads/revert-19006-error-bridging-integer-type: 8a9065a3696535305ea53fe9b71f91cbe6702019
 refs/heads/revert-19050-revert-19006-error-bridging-integer-type: ecf752d54b05dd0a20f510f0bfa54a3fec3bcaca
-refs/heads/rxwei-patch-1: 2cfe8ad52a0f2162808381101b6b80cb75a2b118
+refs/heads/rxwei-patch-1: 6d73ed368ebb1f1abe616c437dae1a9864d44aed
 refs/heads/shahmishal-patch-1: e58ec0f7488258d42bef51bc3e6d7b3dc74d7b2a
 refs/heads/typelist-existential: 4046359efd541fb5c72d69a92eefc0a784df8f5e
 refs/tags/swift-4.2-DEVELOPMENT-SNAPSHOT-2018-08-20-a: 4319ba09e4fb8650ee86061075c74a016b6baab9

branches/rxwei-patch-1/CHANGELOG.md

@@ -26,27 +26,24 @@ CHANGELOG
 Swift Next
 ----------
 
-* [SR-8974][]:
+* [SR-4206][]:
 
-  Duplicate tuple element labels are no longer allowed, because it leads
-  to incorrect behavior. For example:
+  A method override is no longer allowed to have a generic signature with 
+  requirements not imposed by the base method. For example:
 
   ```
-  let dupLabels: (foo: Int, foo: Int) = (foo: 1, foo: 2)
-
-  enum Foo { case bar(x: Int, x: Int) }
-  let f: Foo = .bar(x: 0, x: 1)
+  protocol P {}
+  
+  class Base {
+    func foo<T>(arg: T) {}
+  }
+  
+  class Derived: Base {
+    override func foo<T: P>(arg: T) {}
+  }
   ```
 
-  will now be diagnosed as an error. 
-
-  Note: You can still use duplicate labels when declaring functions and
-  subscripts, as long as the internal labels are different. For example:
-
-  ```
-  func foo(bar x: Int, bar y: Int) {}
-  subscript(a x: Int, a y: Int) -> Int {}
-  ```
+  will now be diagnosed as an error.
 
 * [SR-6118][]:
 
@@ -68,6 +65,28 @@ Swift Next
 Swift 5.1
 ---------
 
+* [SR-8974][]:
+
+  Duplicate tuple element labels are no longer allowed, because it leads
+  to incorrect behavior. For example:
+
+  ```
+  let dupLabels: (foo: Int, foo: Int) = (foo: 1, foo: 2)
+
+  enum Foo { case bar(x: Int, x: Int) }
+  let f: Foo = .bar(x: 0, x: 1)
+  ```
+
+  will now be diagnosed as an error. 
+
+  Note: You can still use duplicate argument labels when declaring functions and
+  subscripts, as long as the internal parameter names are different. For example:
+
+  ```
+  func foo(bar x: Int, bar y: Int) {}
+  subscript(a x: Int, a y: Int) -> Int {}
+  ```
+
 * [SE-0244][]:
 
   Functions can now hide their concrete return type by declaring what protocols
@@ -7708,6 +7727,7 @@ Swift 1.0
 [SR-2608]: <https://bugs.swift.org/browse/SR-2608>
 [SR-2672]: <https://bugs.swift.org/browse/SR-2672>
 [SR-2688]: <https://bugs.swift.org/browse/SR-2688>
+[SR-4206]: <https://bugs.swift.org/browse/SR-4206>
 [SR-4248]: <https://bugs.swift.org/browse/SR-4248>
 [SR-5581]: <https://bugs.swift.org/browse/SR-5581>
 [SR-5719]: <https://bugs.swift.org/browse/SR-5719>

branches/rxwei-patch-1/README.md

@@ -17,7 +17,7 @@
 |**[Debian 9.1 (Raspberry Pi)](https://github.com/apple/swift-community-hosted-continuous-integration/blob/master/nodes/armv7_debian_stretch.json)** | ARMv7 | [![Build Status](https://ci-external.swift.org/job/oss-swift-RA-linux-debian-9_1/lastCompletedBuild/badge/icon)](https://ci-external.swift.org/job/oss-swift-RA-linux-debian-9_1)|
 |**[Fedora 27](https://github.com/apple/swift-community-hosted-continuous-integration/blob/master/nodes/x86_64_fedora_27.json)** | x86_64 |[![Build Status](https://ci-external.swift.org/job/oss-swift-RA-linux-fedora-27/lastCompletedBuild/badge/icon)](https://ci-external.swift.org/job/oss-swift-RA-linux-fedora-27)|
 |**[Ubuntu 16.04](https://github.com/apple/swift-community-hosted-continuous-integration/blob/master/nodes/x86_64_ubuntu_16_04.json)** | x86_64 |[![Build Status](https://ci-external.swift.org/job/oss-swift-RA-linux-ubuntu-16.04/lastCompletedBuild/badge/icon)](https://ci-external.swift.org/job/oss-swift-RA-linux-ubuntu-16.04)|
-|**[Ubuntu 16.04 ](https://github.com/apple/swift-community-hosted-continuous-integration/blob/master/nodes/ppc64le_ubuntu_16_04.json)** | PPC64LE |[![Build Status](https://ci-external.swift.org/job/oss-swift-4.1-RA-linux-ubuntu-16.04-ppc64le/lastCompletedBuild/badge/icon)](https://ci-external.swift.org/job/oss-swift-4.1-RA-linux-ubuntu-16.04-ppc64le)|
+|**[Ubuntu 16.04 ](https://github.com/apple/swift-community-hosted-continuous-integration/blob/master/nodes/ppc64le_ubuntu_16_04.json)** | PPC64LE |[![Build Status](https://ci-external.swift.org/job/oss-swift-5.1-RA-linux-ubuntu-16.04-ppc64le/lastCompletedBuild/badge/icon)](https://ci-external.swift.org/job/oss-swift-5.1-RA-linux-ubuntu-16.04-ppc64le)|
 |**[Ubuntu 16.04 ](https://github.com/apple/swift-community-hosted-continuous-integration/blob/master/nodes/aarch64_ubuntu_16.04.json)** | AArch64 |[![Build Status](https://ci-external.swift.org/job/oss-swift-RA-linux-ubuntu-16.04-aarch64/lastCompletedBuild/badge/icon)](https://ci-external.swift.org/job/oss-swift-RA-linux-ubuntu-16.04-aarch64)|
 |**[Android](https://github.com/apple/swift-community-hosted-continuous-integration/blob/master/nodes/x86_64_ubuntu_16_04_LTS_android.json)** | ARMv7 |[![Build Status](https://ci-external.swift.org/job/oss-swift-RA-linux-ubuntu-16.04-android/lastCompletedBuild/badge/icon)](https://ci-external.swift.org/job/oss-swift-RA-linux-ubuntu-16.04-android)|
 |**[Android](https://github.com/apple/swift-community-hosted-continuous-integration/blob/master/nodes/x86_64_ubuntu_16_04_LTS_android.json)** | AArch64 |[![Build Status](https://ci-external.swift.org/job/oss-swift-RA-linux-ubuntu-16.04-android-arm64/lastCompletedBuild/badge/icon)](https://ci-external.swift.org/job/oss-swift-RA-linux-ubuntu-16.04-android-arm64)|

branches/rxwei-patch-1/benchmark/CMakeLists.txt

@@ -78,6 +78,8 @@ set(SWIFT_BENCH_MODULES
     single-source/DictionaryRemove
     single-source/DictionarySubscriptDefault
     single-source/DictionarySwap
+    single-source/Diffing
+    single-source/DiffingMyers
     single-source/DropFirst
     single-source/DropLast
     single-source/DropWhile

branches/rxwei-patch-1/benchmark/single-source/AngryPhonebook.swift

@@ -13,13 +13,60 @@
 // This test is based on single-source/Phonebook, with
 // to test uppercase and lowercase ASCII string fast paths.
 import TestsUtils
-import Foundation
 
-public let AngryPhonebook = BenchmarkInfo(
-  name: "AngryPhonebook",
-  runFunction: run_AngryPhonebook,
-  tags: [.validation, .api, .String],
-  legacyFactor: 7)
+let t: [BenchmarkCategory] = [.validation, .api, .String]
+
+public let AngryPhonebook = [
+  BenchmarkInfo(
+    name: "AngryPhonebook",
+    runFunction: run_AngryPhonebook,
+    tags: t,
+    legacyFactor: 7),
+
+  // Small String Workloads
+  BenchmarkInfo(
+    name: "AngryPhonebook.ASCII.Small",
+    runFunction: { angryPhonebook($0, ascii) },
+    tags: t,
+    setUpFunction: { blackHole(ascii) }),
+  BenchmarkInfo(
+    name: "AngryPhonebook.Strasse.Small",
+    runFunction: { angryPhonebook($0, strasse) },
+    tags: t,
+    setUpFunction: { blackHole(strasse) }),
+  BenchmarkInfo(
+    name: "AngryPhonebook.Armenian.Small",
+    runFunction: { angryPhonebook($0, armenian) },
+    tags: t,
+    setUpFunction: { blackHole(armenian) }),
+  BenchmarkInfo(
+    name: "AngryPhonebook.Cyrillic.Small",
+    runFunction: { angryPhonebook($0, cyrillic) },
+    tags: t,
+    setUpFunction: { blackHole(cyrillic) }),
+
+  // Regular String Workloads
+  BenchmarkInfo(
+    name: "AngryPhonebook.ASCII",
+    runFunction: { angryPhonebook($0, precomposed: longASCII) },
+    tags: t,
+    setUpFunction: { blackHole(longASCII) }),
+  BenchmarkInfo(
+    name: "AngryPhonebook.Strasse",
+    runFunction: { angryPhonebook($0, precomposed: longStrasse) },
+    tags: t,
+    setUpFunction: { blackHole(longStrasse) }),
+  BenchmarkInfo(
+    name: "AngryPhonebook.Armenian",
+    runFunction: { angryPhonebook($0, precomposed: longArmenian) },
+    tags: t,
+    setUpFunction: { blackHole(longArmenian) }),
+  BenchmarkInfo(
+    name: "AngryPhonebook.Cyrillic",
+    runFunction: { angryPhonebook($0, precomposed: longCyrillic) },
+    tags: t,
+    setUpFunction: { blackHole(longCyrillic) })
+]
 
 let words = [
   "James", "John", "Robert", "Michael", "William", "David", "Richard", "Joseph",
@@ -39,3 +86,67 @@ public func run_AngryPhonebook(_ N: Int) {
     }
   }
 }
+
+// Workloads for various scripts. Always 20 names for 400 pairings.
+// To keep the performance of various scripts roughly comparable, aim for
+// a total length of approximately 120 characters.
+// E.g.: `ascii.joined(separator: "").count == 124`
+// Every name should fit in 15-bytes UTF-8 encoded, to excercise the small
+// string optimization.
+// E.g.: `armenian.allSatisfy { $0._guts.isSmall } == true`
+
+// Workload Size Statistics
+//   SMALL  | UTF-8 | UTF-16 |    REGULAR   |  UTF-8  | UTF-16
+// ---------|-------|--------|--------------|---------|--------
+//    ascii | 124 B |  248 B |    longASCII |  6158 B | 12316 B
+//  strasse | 140 B |  240 B |  longStrasse |  6798 B | 11996 B
+// armenian | 232 B |  232 B | longArmenian | 10478 B | 11676 B
+// cyrillic | 238 B |  238 B | longCyrillic | 10718 B | 11916 B
+
+let ascii = Array(words.prefix(20))
+// Pathological case, uppercase: ß -> SS
+let strasse = Array(repeating: "Straße", count: 20)
+
+let armenian = [
+  "Արմեն", "Աննա", "Հարութ", "Միքայել", "Մարիա", "Դավիթ", "Վարդան",
+  "Նարինե", "Տիգրան", "Տաթևիկ", "Թագուհի", "Թամարա", "Ազնաուր", "Գրիգոր",
+  "Կոմիտաս", "Հայկ", "Գառնիկ", "Վահրամ", "Վահագն", "Գևորգ"]
+
+let cyrillic = [
+  "Ульяна", "Аркадий", "Аня", "Даниил", "Дмитрий", "Эдуард", "Юрій", "Давид",
+  "Анна", "Дмитрий", "Евгений", "Борис", "Ксения", "Артур", "Аполлон",
+  "Соломон", "Николай", "Кристи", "Надежда", "Спартак"]
+
+/// Precompose the phonebook into one large string of comma separated names.
+func phonebook(_ names: [String]) -> String {
+  names.map { firstName in
+    names.map { lastName in
+      firstName + " " + lastName
+    }.joined(separator: ", ")
+  }.joined(separator: ", ")
+}
+
+let longASCII = phonebook(ascii)
+let longStrasse = phonebook(strasse)
+let longArmenian = phonebook(armenian)
+let longCyrillic = phonebook(cyrillic)
+
+@inline(never)
+public func angryPhonebook(_ N: Int, _ names: [String]) {
+  assert(names.count == 20)
+  // Permute the names.
+  for _ in 1...N {
+    for firstname in names {
+      for lastname in names {
+        blackHole((firstname.uppercased(), lastname.lowercased()))
+      }
+    }
+  }
+}
+
+@inline(never)
+public func angryPhonebook(_ N: Int, precomposed names: String) {
+  for _ in 1...N {
+    blackHole((names.uppercased(), names.lowercased()))
+  }
+}

branches/rxwei-patch-1/benchmark/single-source/BinaryFloatingPointConversionFromBinaryInteger.swift

@@ -13,7 +13,6 @@
 // This test checks performance of generic binary floating-point conversion from
 // a binary integer.
 
-import Foundation
 import TestsUtils
 
 #if swift(>=4.2)
@@ -110,7 +109,7 @@ extension MockBinaryInteger : BinaryInteger {
   var trailingZeroBitCount: Int {
     return _value.trailingZeroBitCount
   }
-  
+
   func isMultiple(of other: MockBinaryInteger<T>) -> Bool {
     return _value.isMultiple(of: other._value)
   }
@@ -211,4 +210,3 @@ public func run_BinaryFloatingPointConversionFromBinaryInteger(_ N: Int) {
 }
 
 #endif
-

branches/rxwei-patch-1/benchmark/single-source/BinaryFloatingPointProperties.swift

@@ -10,7 +10,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-import Foundation
 import TestsUtils
 
 public let BinaryFloatingPointPropertiesBinade = BenchmarkInfo(

branches/rxwei-patch-1/benchmark/single-source/BitCount.swift

@@ -13,7 +13,6 @@
 // This test checks performance of Swift bit count.
 // and mask operator.
 // rdar://problem/22151678
-import Foundation
 import TestsUtils
 
 public let BitCount = BenchmarkInfo(

branches/rxwei-patch-1/benchmark/single-source/BucketSort.swift

@@ -16,17 +16,16 @@
 // https://github.com/raywenderlich/swift-algorithm-club/tree/master/Bucket%20Sort
 //
 // It sorts an array of generic `SortableItem`s. If the type of `sortingAlgo`
-// is not known to the call site at line 90, the `sort` method can not be
+// is not known to the call site at line 89, the `sort` method can not be
 // specialized to integer array sorting, which will lead to a huge performance
 // loss. Since `SortingAlgorithm` and `InsertionSort` are declared to be
-// `public` and the lines 89-91 can not be inlined in `bucketSort` (due to
+// `public` and the lines 88-90 can not be inlined in `bucketSort` (due to
 // inlining heuristic limitations), compiler without ExistentialSpecializer
 // optimization can not achieve this feat. With ExistentialSpecializer which
 // enables generic specialization recursively in a call chain, we're able to
-// specialize line 90 for `InsertionSort` on integers.
+// specialize line 89 for `InsertionSort` on integers.
 
 import TestsUtils
-import Foundation
 
 public let BucketSort = BenchmarkInfo(
   name: "BucketSort",
@@ -117,7 +116,8 @@ let items: [Int] = {
 let buckets: [Bucket<Int>] = {
   let bucketCount = 10
   let maxValue = items.max()!.convertToInt()
-  let maxCapacity = Int(ceil(Double(maxValue + 1) / Double(bucketCount)))
+  let maxCapacity = Int(
+    (Double(maxValue + 1) / Double(bucketCount)).rounded(.up))
   return (0..<bucketCount).map { _ in Bucket<Int>(capacity: maxCapacity) }
 }()
 

branches/rxwei-patch-1/benchmark/single-source/ByteSwap.swift

@@ -13,7 +13,6 @@
 // This test checks performance of Swift byte swap.
 // rdar://problem/22151907
 
-import Foundation
 import TestsUtils
 
 public let ByteSwap = BenchmarkInfo(

branches/rxwei-patch-1/benchmark/single-source/CString.swift

@@ -13,6 +13,8 @@
 import TestsUtils
 #if os(Linux)
 import Glibc
+#elseif os(Windows)
+import MSVCRT
 #else
 import Darwin
 #endif

branches/rxwei-patch-1/benchmark/single-source/Calculator.swift

@@ -11,7 +11,6 @@
 //===----------------------------------------------------------------------===//
 
 import TestsUtils
-import Foundation
 
 public let Calculator = BenchmarkInfo(
   name: "Calculator",
@@ -53,4 +52,3 @@ public func run_Calculator(_ N: Int) {
   }
   CheckResults(c == 0)
 }
-