[benchmark] Add String.init UTF-8 decoding benchmarks

benchmark/single-source/UTF8Decode.swift

@@ -11,26 +11,61 @@
 //===----------------------------------------------------------------------===//
 
 import TestsUtils
+import Foundation
+
+public let UTF8Decode = [
+    BenchmarkInfo(
+      name: "UTF8Decode",
+      runFunction: run_UTF8Decode,
+      tags: [.validation, .api, .String]),
+    BenchmarkInfo(
+      name: "UTF8Decode_InitFromData",
+      runFunction: run_UTF8Decode_InitFromData,
+      tags: [.validation, .api, .String]),
+    BenchmarkInfo(
+      name: "UTF8Decode_InitDecoding",
+      runFunction: run_UTF8Decode_InitDecoding,
+      tags: [.validation, .api, .String]),
+    BenchmarkInfo(
+      name: "UTF8Decode_InitFromBytes",
+      runFunction: run_UTF8Decode_InitFromBytes,
+      tags: [.validation, .api, .String]),
+    BenchmarkInfo(
+      name: "UTF8Decode_InitFromData_ascii",
+      runFunction: run_UTF8Decode_InitFromData_ascii,
+      tags: [.validation, .api, .String]),
+    BenchmarkInfo(
+      name: "UTF8Decode_InitDecoding_ascii",
+      runFunction: run_UTF8Decode_InitDecoding_ascii,
+      tags: [.validation, .api, .String]),
+    BenchmarkInfo(
+      name: "UTF8Decode_InitFromBytes_ascii",
+      runFunction: run_UTF8Decode_InitFromBytes_ascii,
+      tags: [.validation, .api, .String]),
+]
+
+// 1-byte sequences
+// This test case is the longest as it's the most performance sensitive.
+let ascii = "Swift is a multi-paradigm, compiled programming language created for iOS, OS X, watchOS, tvOS and Linux development by Apple Inc. Swift is designed to work with Apple's Cocoa and Cocoa Touch frameworks and the large body of existing Objective-C code written for Apple products. Swift is intended to be more resilient to erroneous code (\"safer\") than Objective-C and also more concise. It is built with the LLVM compiler framework included in Xcode 6 and later and uses the Objective-C runtime, which allows C, Objective-C, C++ and Swift code to run within a single program."
+let asciiBytes: [UInt8] = Array(ascii.utf8)
+let asciiData: Data = Data(asciiBytes)
+
+// 2-byte sequences
+let russian = "Ру́сский язы́к один из восточнославянских языков, национальный язык русского народа."
+// 3-byte sequences
+let japanese = "日本語（にほんご、にっぽんご）は、主に日本国内や日本人同士の間で使われている言語である。"
+// 4-byte sequences
+// Most commonly emoji, which are usually mixed with other text.
+let emoji = "Panda 🐼, Dog 🐶, Cat 🐱, Mouse 🐭."
+
+let allStrings = [ascii, russian, japanese, emoji].map { Array($0.utf8) }
+let allStringsBytes: [UInt8] = Array(allStrings.joined())
+let allStringsData: Data = Data(allStringsBytes)
 
-public let UTF8Decode = BenchmarkInfo(
-  name: "UTF8Decode",
-  runFunction: run_UTF8Decode,
-  tags: [.validation, .api, .String])
 
 @inline(never)
 public func run_UTF8Decode(_ N: Int) {
-  // 1-byte sequences
-  // This test case is the longest as it's the most performance sensitive.
-  let ascii = "Swift is a multi-paradigm, compiled programming language created for iOS, OS X, watchOS, tvOS and Linux development by Apple Inc. Swift is designed to work with Apple's Cocoa and Cocoa Touch frameworks and the large body of existing Objective-C code written for Apple products. Swift is intended to be more resilient to erroneous code (\"safer\") than Objective-C and also more concise. It is built with the LLVM compiler framework included in Xcode 6 and later and uses the Objective-C runtime, which allows C, Objective-C, C++ and Swift code to run within a single program."
-  // 2-byte sequences
-  let russian = "Ру́сский язы́к один из восточнославянских языков, национальный язык русского народа."
-  // 3-byte sequences
-  let japanese = "日本語（にほんご、にっぽんご）は、主に日本国内や日本人同士の間で使われている言語である。"
-  // 4-byte sequences
-  // Most commonly emoji, which are usually mixed with other text.
-  let emoji = "Panda 🐼, Dog 🐶, Cat 🐱, Mouse 🐭."
-
-  let strings = [ascii, russian, japanese, emoji].map { Array($0.utf8) }
+  let strings = allStrings
 
   func isEmpty(_ result: UnicodeDecodingResult) -> Bool {
     switch result {
@@ -49,3 +84,49 @@ public func run_UTF8Decode(_ N: Int) {
     }
   }
 }
+
+@inline(never)
+public func run_UTF8Decode_InitFromData(_ N: Int) {
+  let input = allStringsData
+  for _ in 0..<200*N {
+    blackHole(String(data: input, encoding: .utf8))
+  }
+}
+@inline(never)
+public func run_UTF8Decode_InitDecoding(_ N: Int) {
+  let input = allStringsBytes
+  for _ in 0..<200*N {
+    blackHole(String(decoding: input, as: UTF8.self))
+  }
+}
+@inline(never)
+public func run_UTF8Decode_InitFromBytes(_ N: Int) {
+  let input = allStringsBytes
+  for _ in 0..<200*N {
+    blackHole(String(bytes: input, encoding: .utf8))
+  }
+}
+
+@inline(never)
+public func run_UTF8Decode_InitFromData_ascii(_ N: Int) {
+  let input = asciiData
+  for _ in 0..<1_000*N {
+    blackHole(String(data: input, encoding: .utf8))
+  }
+}
+@inline(never)
+public func run_UTF8Decode_InitDecoding_ascii(_ N: Int) {
+  let input = asciiBytes
+  for _ in 0..<1_000*N {
+    blackHole(String(decoding: input, as: UTF8.self))
+  }
+}
+@inline(never)
+public func run_UTF8Decode_InitFromBytes_ascii(_ N: Int) {
+  let input = asciiBytes
+  for _ in 0..<1_000*N {
+    blackHole(String(bytes: input, encoding: .utf8))
+  }
+}
+
+