diff --git a/benchmark/single-source/RandomValues.swift b/benchmark/single-source/RandomValues.swift
index 6a5a5b4be2075..cea327d02f24a 100644
--- a/benchmark/single-source/RandomValues.swift
+++ b/benchmark/single-source/RandomValues.swift
@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2018 Apple Inc. and the Swift project authors
+// Copyright (c) 2018 - 2020 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
@@ -19,14 +19,35 @@ import TestsUtils
 //
 
 public let RandomValues = [
-  BenchmarkInfo(name: "RandomIntegersDef", runFunction: run_RandomIntegersDef,
-    tags: [.api], legacyFactor: 100),
-  BenchmarkInfo(name: "RandomIntegersLCG", runFunction: run_RandomIntegersLCG,
-    tags: [.api]),
-  BenchmarkInfo(name: "RandomDoubleDef", runFunction: run_RandomDoubleDef,
-    tags: [.api], legacyFactor: 100),
-  BenchmarkInfo(name: "RandomDoubleLCG", runFunction: run_RandomDoubleLCG,
-    tags: [.api], legacyFactor: 2),
+  BenchmarkInfo(name: "RandomIntegersDef",
+    runFunction: run_RandomIntegersDef, tags: [.api], legacyFactor: 100),
+  
+  BenchmarkInfo(name: "RandomIntegersLCG",
+    runFunction: run_RandomIntegersLCG, tags: [.api]),
+  
+  BenchmarkInfo(name: "RandomDoubleDef",
+    runFunction: run_RandomDoubleDef, tags: [.api], legacyFactor: 100),
+  
+  BenchmarkInfo(name: "RandomDoubleLCG",
+    runFunction: run_RandomDoubleLCG, tags: [.api], legacyFactor: 2),
+  
+  BenchmarkInfo(name: "RandomDoubleUnitDef",
+    runFunction: run_RandomDoubleUnitDef, tags: [.api]),
+  
+  BenchmarkInfo(name: "RandomDoubleUnitLCG",
+    runFunction: run_RandomDoubleUnitLCG, tags: [.api]),
+  
+  BenchmarkInfo(name: "RandomDoubleBinadeDef",
+    runFunction: run_RandomDoubleBinadeDef, tags: [.api]),
+  
+  BenchmarkInfo(name: "RandomDoubleBinadeLCG",
+    runFunction: run_RandomDoubleBinadeLCG, tags: [.api]),
+  
+  BenchmarkInfo(name: "RandomDoubleAsymDef",
+    runFunction: run_RandomDoubleAsymDef, tags: [.api]),
+  
+  BenchmarkInfo(name: "RandomDoubleAsymLCG",
+    runFunction: run_RandomDoubleAsymLCG, tags: [.api]),
 ]
 
 /// A linear congruential PRNG.
@@ -89,3 +110,62 @@ public func run_RandomDoubleLCG(_ N: Int) {
     blackHole(x)
   }
 }
+
+@inline(never)
+public func run_RandomDoubleUnitDef(_ N: Int) {
+  randomDoubleHelperDef(N, 0..<1)
+}
+
+@inline(never)
+public func run_RandomDoubleUnitLCG(_ N: Int) {
+  randomDoubleHelperLCG(N, 0..<1)
+}
+
+@inline(never)
+public func run_RandomDoubleBinadeDef(_ N: Int) {
+  randomDoubleHelperDef(N, 1..<2)
+}
+
+@inline(never)
+public func run_RandomDoubleBinadeLCG(_ N: Int) {
+  randomDoubleHelperLCG(N, 1..<2)
+}
+
+@inline(never)
+public func run_RandomDoubleAsymDef(_ N: Int) {
+  let range = -(1.0.nextDown) ..< 0.126
+  randomDoubleHelperDef(N, range)
+}
+
+@inline(never)
+public func run_RandomDoubleAsymLCG(_ N: Int) {
+  let range = -(1.0.nextDown) ..< 0.126
+  randomDoubleHelperLCG(N, range)
+}
+
+@inline(__always)
+private func randomDoubleHelperDef(
+  _ N: Int, _ range: Range<Double>, reps: Int = 1_000
+) {
+  for _ in 0 ..< N {
+    var x = 0.0
+    for _ in 0 ..< reps {
+      x += Double.random(in: range)
+    }
+    blackHole(x)
+  }
+}
+
+@inline(__always)
+private func randomDoubleHelperLCG(
+  _ N: Int, _ range: Range<Double>, reps: Int = 50_000
+) {
+  for _ in 0 ..< N {
+    var x = 0.0
+    var generator = LCRNG(seed: 0)
+    for _ in 0 ..< reps {
+      x += Double.random(in: range, using: &generator)
+    }
+    blackHole(x)
+  }
+}