Reverted a change that should have gone into another branch.

Author: fibrechannelscsi

benchmark/single-source/KeyPathPerformanceTests.swift

@@ -66,12 +66,6 @@ public let benchmarks = [
     tags: [.validation, .api],
     setUpFunction: setupKeyPathNestedStructs
   ),
-  BenchmarkInfo(
-    name: "KeyPathClassStructs",
-    runFunction: run_KeyPathClassStructs,
-    tags: [.validation, .api],
-    setUpFunction: setupKeyPathNestedStructs
-  ),
 ]
 
 /**
@@ -103,7 +97,6 @@ class FixedSizeArrayHolder {
   var fixedSizeArray100: FixedSizeArray100<ElementType>
   var fixedSizeArray10: FixedSizeArray10<ElementType>
   var mainArrayForNestedStructs: [A]
-  var mainArrayForClassStructs: [D1]
   var arrayForMutatingGetset: [MutatingGetsetNested1]
   var arrayForGet: [GetNested1]
   var arrayForOptionals: [Optional1]
@@ -114,7 +107,6 @@ class FixedSizeArrayHolder {
   var keypathForOptional: KeyPath<Optional1, Int?>
   var keypathForNestedClasses: KeyPath<C1, Int>
   var keypathForNonMutatingGetset: WritableKeyPath<M, Int>
-  var keypathForClassStructs: WritableKeyPath<D1, Int>
 
   // Same order as in KeyPathWritePerformance
   var kp46: WritableKeyPath<FixedSizeArray100<ElementType>, ElementType>
@@ -184,7 +176,6 @@ class FixedSizeArrayHolder {
     fixedSizeArray100 = initializeFixedSizeArray100()
     fixedSizeArray10 = initializeFixedSizeArray10()
     mainArrayForNestedStructs = [A]()
-    mainArrayForClassStructs = [D1]()
     arrayForMutatingGetset = [MutatingGetsetNested1]()
     arrayForGet = [GetNested1]()
     arrayForOptionals = [Optional1]()
@@ -261,7 +252,6 @@ class FixedSizeArrayHolder {
       ._nestedItemStorage?!._nestedItemStorage?!._storage)
     keypathForNestedClasses = identity(\C1.r.r.r.r.a)
     keypathForNonMutatingGetset = identity(\M.n.o.p.q.q)
-    keypathForClassStructs = identity(\D1.b.c.d.e.e)
   }
 }
 
@@ -272,10 +262,6 @@ public func setupKeyPathNestedStructs() {
     let instance = A(a: 0, b: B(b: 0, c: C(c: 0, d: D(d: 0, e: E(e: expectedIntForNestedItems)))))
     holder.mainArrayForNestedStructs.append(instance)
 
-    let classStructInstance = D1(b: D2(b: 0, c: D3(c: 0, d: D4(d: 0,
-      e: D5(e: expectedIntForNestedItems)))))
-    holder.mainArrayForClassStructs.append(classStructInstance)
-      
     var mutatingGetsetInstance = MutatingGetsetNested1()
     mutatingGetsetInstance.nestedItem.nestedItem.nestedItem.nestedItem
       .storage = expectedIntForNestedItems
@@ -347,36 +333,6 @@ struct E {
   var e: Int
 }
 
-// Used for run_KeyPathClassStruct().
-class D1 {
-  var a: Int
-  var b: D2
-  init(b: D2)
-  {
-    a = 0
-    self.b = b
-  }
-}
-
-struct D2 {
-  var b: Int
-  var c: D3
-}
-
-struct D3 {
-  var c: Int
-  var d: D4
-}
-
-struct D4 {
-  var d: Int
-  var e: D5
-}
-
-struct D5 {
-  var e: Int
-}
-
 // Used for run_KeyPathNestedClasses()
 class C1 {
   let a: Int = 0
@@ -1370,36 +1326,6 @@ public func run_KeyPathNestedStructs(n: Int) {
   check(sum == iterationMultipier * n * expectedIntForNestedItems)
 }
 
-// This measures the performance of keypath reads where a block of
-// trivially-typed memory is preceded by something else (optionals, reference
-// types, etc.)
-@inline(never)
-public func run_KeyPathClassStructs(n: Int) {
-  var sum = 0
-  var index = 0
-  let iterationMultipier = 2000
-
-  let singleHopKeyPath0: WritableKeyPath<D1, D2> = \D1.b
-  let singleHopKeyPath1: WritableKeyPath<D2, D3> = \D2.c
-  let singleHopKeyPath2: WritableKeyPath<D3, D4> = \D3.d
-  let singleHopKeyPath3: WritableKeyPath<D4, D5> = \D4.e
-  let singleHopKeyPath4: WritableKeyPath<D5, Int> = \D5.e
-
-  let appendedKeyPath = identity(singleHopKeyPath0.appending(path: singleHopKeyPath1)
-    .appending(path: singleHopKeyPath2).appending(path: singleHopKeyPath3)
-    .appending(path: singleHopKeyPath4))
-
-  let elementCount = FixedSizeArrayHolder.shared.mainArrayForClassStructs.count
-  for _ in 1 ... iterationMultipier * n {
-    let element = FixedSizeArrayHolder.shared.mainArrayForClassStructs[index]
-    sum += element[keyPath: appendedKeyPath]
-    index = (index + 1) % elementCount
-  }
-  check(sum == iterationMultipier * n * expectedIntForNestedItems)
-}
-
-
-
 // This is meant as a baseline, from a timing perspective,
 // for run_testKeyPathReadPerformance() and run_testKeyPathWritePerformance().
 // It's currently set to ".skip", but is useful for comparing the performance between keypath operations and direct dot-notation.