diff --git a/benchmark/single-source/DictionaryCompactMapValues.swift b/benchmark/single-source/DictionaryCompactMapValues.swift
index 65dfc2c194ac3..92f24e5c3c31e 100644
--- a/benchmark/single-source/DictionaryCompactMapValues.swift
+++ b/benchmark/single-source/DictionaryCompactMapValues.swift
@@ -1,76 +1,47 @@
-// Dictionary compact map values benchmark
+//===--- DictionaryCompactMapValues.swift ---------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
 import TestsUtils
 
+let size = 100
+let oddNumbers = stride(from: 1, to: size, by: 2)
+let smallOddNumMap: [Int: Int?] =
+  Dictionary(uniqueKeysWithValues: zip(oddNumbers, oddNumbers))
+let compactOddNums: [Int: Int] =
+  Dictionary(uniqueKeysWithValues: zip(oddNumbers, oddNumbers))
+let oddStringMap: [Int: String] = Dictionary(uniqueKeysWithValues:
+  (1...size).lazy.map { ($0, $0 % 2 == 0 ? "dummy" : "\($0)") })
+
+let t: [BenchmarkCategory] = [.validation, .api, .Dictionary]
+
 public let DictionaryCompactMapValues = [
   BenchmarkInfo(name: "DictionaryCompactMapValuesOfNilValue",
-    runFunction: run_DictionaryCompactMapValuesOfNilValue,
-    tags: [.validation, .api, .Dictionary],
+    runFunction: compactMapValues, tags: t,
+    setUpFunction: { blackHole(smallOddNumMap); blackHole(compactOddNums)},
     legacyFactor: 50),
   BenchmarkInfo(name: "DictionaryCompactMapValuesOfCastValue",
-    runFunction: run_DictionaryCompactMapValuesOfCastValue,
-    tags: [.validation, .api, .Dictionary],
-    legacyFactor: 50),
+    runFunction: compactMapValuesInt, tags: t,
+    setUpFunction: { blackHole(oddStringMap); blackHole(compactOddNums)},
+    legacyFactor: 54),
 ]
 
-@inline(never)
-public func run_DictionaryCompactMapValuesOfNilValue(_ N: Int) {
-  let size = 100
-  var dict = [Int: Int?](minimumCapacity: size)
-
-  // Fill Dictionary
-  for i in 1...size {
-    if i % 2 == 0 {
-      dict[i] = nil
-    } else {
-      dict[i] = i
-    }
-  }
-  CheckResults(dict.count == size / 2)
-
-  var refDict = [Int: Int]()
-  for i in stride(from: 1, to: 100, by: 2) {
-    refDict[i] = i
-  }
-
-  var newDict = [Int: Int]()
+func compactMapValues(N: Int) {
   for _ in 1...20*N {
-    newDict = dict.compactMapValues({$0})
-    if newDict != refDict {
-      break
-    }
+    CheckResults(smallOddNumMap.compactMapValues({$0}) == compactOddNums)
   }
-
-  CheckResults(newDict == refDict)
 }
 
-@inline(never)
-public func run_DictionaryCompactMapValuesOfCastValue(_ N: Int) {
-  let size = 100
-  var dict = [Int: String](minimumCapacity: size)
-
-  // Fill Dictionary
-  for i in 1...size {
-    if i % 2 == 0 {
-      dict[i] = "dummy"
-    } else {
-      dict[i] = "\(i)"
-    }
-  }
-
-  CheckResults(dict.count == size)
-
-  var refDict = [Int: Int]()
-  for i in stride(from: 1, to: 100, by: 2) {
-    refDict[i] = i
-  }
-
-  var newDict = [Int: Int]()
+func compactMapValuesInt(N: Int) {
   for _ in 1...20*N {
-    newDict = dict.compactMapValues(Int.init)
-    if newDict != refDict {
-      break
-    }
+    CheckResults(oddStringMap.compactMapValues(Int.init) == compactOddNums)
   }
-
-  CheckResults(newDict == refDict)
 }
diff --git a/benchmark/single-source/DictionaryGroup.swift b/benchmark/single-source/DictionaryGroup.swift
index 927dbe54f8add..562c19b3c5627 100644
--- a/benchmark/single-source/DictionaryGroup.swift
+++ b/benchmark/single-source/DictionaryGroup.swift
@@ -13,21 +13,24 @@
 import TestsUtils
 
 public let DictionaryGroup = [
-  BenchmarkInfo(name: "DictionaryGroup", runFunction: run_DictionaryGroup, tags: [.validation, .api, .Dictionary]),
-  BenchmarkInfo(name: "DictionaryGroupOfObjects", runFunction: run_DictionaryGroupOfObjects, tags: [.validation, .api, .Dictionary],
+  BenchmarkInfo(name: "DictionaryGroup",
+    runFunction: run_DictionaryGroup,
+    tags: [.validation, .api, .Dictionary]),
+  BenchmarkInfo(name: "DictionaryGroupOfObjects",
+    runFunction: run_DictionaryGroupOfObjects,
+    tags: [.validation, .api, .Dictionary],
     setUpFunction: { blackHole(inputObjects) },
-    tearDownFunction: { inputObjects = nil }),
+    tearDownFunction: { inputObjects = nil },
+    legacyFactor: 9
+  ),
 ]
 
-let count = 10_000
-let result = count / 10
-
 @inline(never)
 public func run_DictionaryGroup(_ N: Int) {
   for _ in 1...N {
-    let dict = Dictionary(grouping: 0..<count, by: { $0 % 10 })
+    let dict = Dictionary(grouping: 0..<10_000, by: { $0 % 10 })
     CheckResults(dict.count == 10)
-    CheckResults(dict[0]!.count == result)
+    CheckResults(dict[0]!.count == 1_000)
   }
 }
 
@@ -47,7 +50,7 @@ class Box<T : Hashable> : Hashable {
   }
 }
 
-var inputObjects: [Box<Int>]! = (0..<count).map { Box($0) }
+var inputObjects: [Box<Int>]! = (0..<1_000).lazy.map { Box($0) }
 
 @inline(never)
 public func run_DictionaryGroupOfObjects(_ N: Int) {
@@ -55,6 +58,6 @@ public func run_DictionaryGroupOfObjects(_ N: Int) {
   for _ in 1...N {
     let dict = Dictionary(grouping: objects, by: { Box($0.value % 10) })
     CheckResults(dict.count == 10)
-    CheckResults(dict[Box(0)]!.count == result)
+    CheckResults(dict[Box(0)]!.count == 100)
   }
 }