[benchmark] Extract setup from ArrayAppend*

ArrayAppendStrings had setup overhead of 10ms (42%). ArrayAppendLazyMap had setup overhead of 24 μs (1%).

ArrayAppendOptionals and ArrayAppendArrayOfInt also had barely visible, small overhead of ~18μs, that was mostly hidden in measurement noise, but I’ve extracted the setup from all places that had 10 000 element array initializations, in preparation for more precise measurement in the future.

Author: palimondo

benchmark/single-source/ArrayAppend.swift

@@ -17,29 +17,50 @@ import TestsUtils
 let t: [BenchmarkCategory] = [.validation, .api, .Array]
 public let ArrayAppend = [
   BenchmarkInfo(name: "ArrayAppend", runFunction: run_ArrayAppend, tags: t),
-  BenchmarkInfo(name: "ArrayAppendArrayOfInt", runFunction: run_ArrayAppendArrayOfInt, tags: t),
+  BenchmarkInfo(name: "ArrayAppendArrayOfInt", runFunction: run_ArrayAppendArrayOfInt, tags: t,
+    setUpFunction: ones, tearDownFunction: releaseOnes),
   BenchmarkInfo(name: "ArrayAppendAscii", runFunction: run_ArrayAppendAscii, tags: t),
   BenchmarkInfo(name: "ArrayAppendAsciiSubstring", runFunction: run_ArrayAppendAsciiSubstring, tags: t),
-  BenchmarkInfo(name: "ArrayAppendFromGeneric", runFunction: run_ArrayAppendFromGeneric, tags: t),
-  BenchmarkInfo(name: "ArrayAppendGenericStructs", runFunction: run_ArrayAppendGenericStructs, tags: t),
+  BenchmarkInfo(name: "ArrayAppendFromGeneric", runFunction: run_ArrayAppendFromGeneric, tags: t,
+    setUpFunction: ones, tearDownFunction: releaseOnes),
+  BenchmarkInfo(name: "ArrayAppendGenericStructs", runFunction: run_ArrayAppendGenericStructs, tags: t,
+    setUpFunction: { otherStructs = Array(repeating: S(x: 3, y: 4.2), count: 10_000) },
+    tearDownFunction: {  otherStructs = nil } ),
   BenchmarkInfo(name: "ArrayAppendLatin1", runFunction: run_ArrayAppendLatin1, tags: t),
   BenchmarkInfo(name: "ArrayAppendLatin1Substring", runFunction: run_ArrayAppendLatin1Substring, tags: t),
-  BenchmarkInfo(name: "ArrayAppendLazyMap", runFunction: run_ArrayAppendLazyMap, tags: t),
-  BenchmarkInfo(name: "ArrayAppendOptionals", runFunction: run_ArrayAppendOptionals, tags: t),
+  BenchmarkInfo(name: "ArrayAppendLazyMap", runFunction: run_ArrayAppendLazyMap, tags: t,
+    setUpFunction: { blackHole(array) }),
+  BenchmarkInfo(name: "ArrayAppendOptionals", runFunction: run_ArrayAppendOptionals, tags: t,
+    setUpFunction: { otherOptionalOnes = Array(repeating: 1, count: 10_000) },
+    tearDownFunction: {  otherOptionalOnes = nil } ),
   BenchmarkInfo(name: "ArrayAppendRepeatCol", runFunction: run_ArrayAppendRepeatCol, tags: t),
   BenchmarkInfo(name: "ArrayAppendReserved", runFunction: run_ArrayAppendReserved, tags: t),
   BenchmarkInfo(name: "ArrayAppendSequence", runFunction: run_ArrayAppendSequence, tags: t),
-  BenchmarkInfo(name: "ArrayAppendStrings", runFunction: run_ArrayAppendStrings, tags: t),
-  BenchmarkInfo(name: "ArrayAppendToFromGeneric", runFunction: run_ArrayAppendToFromGeneric, tags: t),
-  BenchmarkInfo(name: "ArrayAppendToGeneric", runFunction: run_ArrayAppendToGeneric, tags: t),
+  BenchmarkInfo(name: "ArrayAppendStrings", runFunction: run_ArrayAppendStrings, tags: t,
+    setUpFunction: { otherStrings = stride(from: 0, to: 10_000, by: 1).map { "\($0)" } },
+    tearDownFunction: {  otherStrings = nil } ),
+  BenchmarkInfo(name: "ArrayAppendToFromGeneric", runFunction: run_ArrayAppendToFromGeneric, tags: t,
+    setUpFunction: ones, tearDownFunction: releaseOnes),
+  BenchmarkInfo(name: "ArrayAppendToGeneric", runFunction: run_ArrayAppendToGeneric, tags: t,
+    setUpFunction: ones, tearDownFunction: releaseOnes),
   BenchmarkInfo(name: "ArrayAppendUTF16", runFunction: run_ArrayAppendUTF16, tags: t),
   BenchmarkInfo(name: "ArrayAppendUTF16Substring", runFunction: run_ArrayAppendUTF16Substring, tags: t),
-  BenchmarkInfo(name: "ArrayPlusEqualArrayOfInt", runFunction: run_ArrayPlusEqualArrayOfInt, tags: t),
+  BenchmarkInfo(name: "ArrayPlusEqualArrayOfInt", runFunction: run_ArrayPlusEqualArrayOfInt, tags: t,
+    setUpFunction: ones, tearDownFunction: releaseOnes),
   BenchmarkInfo(name: "ArrayPlusEqualFiveElementCollection", runFunction: run_ArrayPlusEqualFiveElementCollection, tags: t),
   BenchmarkInfo(name: "ArrayPlusEqualSingleElementCollection", runFunction: run_ArrayPlusEqualSingleElementCollection, tags: t),
   BenchmarkInfo(name: "ArrayPlusEqualThreeElements", runFunction: run_ArrayPlusEqualThreeElements, tags: t),
 ]
 
+var otherOnes: [Int]!
+var otherOptionalOnes: [Int?]!
+var otherStrings: [String]!
+var otherStructs: [S<Int, Double>]!
+let array = Array(0..<10_000)
+
+func ones() { otherOnes = Array(repeating: 1, count: 10_000) }
+func releaseOnes() { otherOnes = nil }
+
 // Append single element
 @inline(never)
 public func run_ArrayAppend(_ N: Int) {
@@ -87,7 +108,8 @@ public func run_ArrayAppendSequence(_ N: Int) {
 // can pre-reserve capacity.
 @inline(never)
 public func run_ArrayAppendArrayOfInt(_ N: Int) {
-  let other = Array(repeating: 1, count: 10_000)
+  let other: [Int] = otherOnes
+
   for _ in 0..<N {
     for _ in 0..<10 {
       var nums = [Int]()
@@ -102,7 +124,8 @@ public func run_ArrayAppendArrayOfInt(_ N: Int) {
 // except +=, to check equally performant.
 @inline(never)
 public func run_ArrayPlusEqualArrayOfInt(_ N: Int) {
-  let other = Array(repeating: 1, count: 10_000)
+  let other: [Int] = otherOnes
+
   for _ in 0..<N {
     for _ in 0..<10 {
       var nums = [Int]()
@@ -117,7 +140,8 @@ public func run_ArrayPlusEqualArrayOfInt(_ N: Int) {
 // can pre-reserve capacity.
 @inline(never)
 public func run_ArrayAppendStrings(_ N: Int) {
-  let other = stride(from: 0, to: 10_000, by: 1).map { "\($0)" }
+  let other: [String] = otherStrings
+
   for _ in 0..<N {
     for _ in 0..<10 {
       var nums = [String]()
@@ -138,7 +162,8 @@ struct S<T,U> {
 // can pre-reserve capacity.
 @inline(never)
 public func run_ArrayAppendGenericStructs(_ N: Int) {
-  let other = Array(repeating: S(x: 3, y: 4.2), count: 10_000)
+  let other: [S<Int, Double>] = otherStructs
+
   for _ in 0..<N {
     for _ in 0..<10 {
       var nums = [S<Int, Double>]()
@@ -153,7 +178,7 @@ public func run_ArrayAppendGenericStructs(_ N: Int) {
 // can pre-reserve capacity.
 @inline(never)
 public func run_ArrayAppendOptionals(_ N: Int) {
-  let other: [Int?] = Array(repeating: 1, count: 10_000)
+  let other: [Int?] = otherOptionalOnes
 
   for _ in 0..<N {
     for _ in 0..<10 {
@@ -170,7 +195,7 @@ public func run_ArrayAppendOptionals(_ N: Int) {
 // can pre-reserve capacity, but no optimization points used.
 @inline(never)
 public func run_ArrayAppendLazyMap(_ N: Int) {
-  let other = Array(0..<10_000).lazy.map { $0 * 2 }
+  let other = array.lazy.map { $0 * 2 }
 
   for _ in 0..<N {
     for _ in 0..<10 {
@@ -210,7 +235,7 @@ public func appendFromGeneric<
 
 @inline(never)
 public func run_ArrayAppendFromGeneric(_ N: Int) {
-  let other = Array(repeating: 1, count: 10_000)
+  let other: [Int] = otherOnes
 
   for _ in 0..<N {
     for _ in 0..<10 {
@@ -232,7 +257,7 @@ public func appendToGeneric<
 
 @inline(never)
 public func run_ArrayAppendToGeneric(_ N: Int) {
-  let other = Array(repeating: 1, count: 10_000)
+  let other: [Int] = otherOnes
 
   for _ in 0..<N {
     for _ in 0..<10 {
@@ -256,7 +281,7 @@ where R.Element == S.Element {
 
 @inline(never)
 public func run_ArrayAppendToFromGeneric(_ N: Int) {
-  let other = Array(repeating: 1, count: 10_000)
+  let other: [Int] = otherOnes
 
   for _ in 0..<N {
     for _ in 0..<10 {