Merge pull request #15337 from lorentey/wordcount-is-flaky

[benchmark] WordCount: Initialize global variables in setUpFunction.

Author: lorentey

benchmark/single-source/WordCount.swift

@@ -26,28 +26,39 @@ public let WordCount = [
   BenchmarkInfo(
     name: "WordSplitASCII",
     runFunction: run_WordSplitASCII,
-    tags: [.validation, .api, .String, .algorithm]),
+    tags: [.validation, .api, .String, .algorithm],
+    setUpFunction: { buildWorkload() }
+  ),
   BenchmarkInfo(
     name: "WordSplitUTF16",
     runFunction: run_WordSplitUTF16,
-    tags: [.validation, .api, .String, .algorithm]),
+    tags: [.validation, .api, .String, .algorithm],
+    setUpFunction: { buildWorkload() }
+  ),
   BenchmarkInfo(
     name: "WordCountUniqueASCII",
     runFunction: run_WordCountUniqueASCII,
-    tags: [.validation, .api, .String, .Dictionary, .algorithm]),
+    tags: [.validation, .api, .String, .Dictionary, .algorithm],
+    setUpFunction: { buildWorkload() }
+  ),
   BenchmarkInfo(
     name: "WordCountUniqueUTF16",
     runFunction: run_WordCountUniqueUTF16,
-    tags: [.validation, .api, .String, .Dictionary, .algorithm]),
+    tags: [.validation, .api, .String, .Dictionary, .algorithm],
+    setUpFunction: { buildWorkload() }
+  ),
   BenchmarkInfo(
     name: "WordCountHistogramASCII",
     runFunction: run_WordCountHistogramASCII,
-    tags: [.validation, .api, .String, .Dictionary, .algorithm]),
+    tags: [.validation, .api, .String, .Dictionary, .algorithm],
+    setUpFunction: { buildWorkload() }
+  ),
   BenchmarkInfo(
     name: "WordCountHistogramUTF16",
     runFunction: run_WordCountHistogramUTF16,
-    tags: [.validation, .api, .String, .Dictionary, .algorithm]),
-  
+    tags: [.validation, .api, .String, .Dictionary, .algorithm],
+    setUpFunction: { buildWorkload() }
+  ),
 ]
 
 let asciiText = """
@@ -129,6 +140,13 @@ source code and over 20 GB of disk space for thé build artifacts. A clean build
 can take multiple hours, but incremental builds will finish much faster.
 """
 
+@inline(never)
+func buildWorkload() {
+  blackHole(someAlphanumerics)
+  blackHole(asciiWords)
+  blackHole(utf16Words)
+}
+
 // A partial set of Unicode alphanumeric characters. (ASCII letters with at most
 // one diacritic (of a limited selection), plus ASCII digits.)
 let someAlphanumerics: Set<Character> = {
@@ -184,16 +202,18 @@ struct Words: IteratorProtocol, Sequence {
 @inline(never)
 public func run_WordSplitASCII(_ N: Int) {
   for _ in 1...10*N {
-    let count = Array(Words(identity(asciiText))).count
-    CheckResults(count == 280)
+    let words = Array(Words(identity(asciiText)))
+    CheckResults(words.count == 280)
+    blackHole(words)
   }
 }
 
 @inline(never)
 public func run_WordSplitUTF16(_ N: Int) {
   for _ in 1...10*N {
-    let count = Array(Words(identity(utf16Text))).count
-    CheckResults(count == 280)
+    let words = Array(Words(identity(utf16Text)))
+    CheckResults(words.count == 280)
+    blackHole(words)
   }
 }