diff --git a/benchmark/single-source/ArrayAppend.swift b/benchmark/single-source/ArrayAppend.swift
index ead10b2da63bf..78cee2d5d1207 100644
--- a/benchmark/single-source/ArrayAppend.swift
+++ b/benchmark/single-source/ArrayAppend.swift
@@ -42,15 +42,14 @@ public func run_ArrayAppendReserved(_ N: Int) {
 }
 
 // Append a sequence. Length of sequence unknown so
-// can't pre-reserve capacity. Should be comparable
-// to append single elements.
+// can't pre-reserve capacity. 
 @inline(never)
 public func run_ArrayAppendSequence(_ N: Int) {
   let seq = stride(from: 0, to: 10_000, by: 1)
   for _ in 0..<N {
     for _ in 0..<10 {
       var nums = [Int]()
-      for _ in 0..<4 {
+      for _ in 0..<8 {
         nums.append(contentsOf: seq)
       }
     }
@@ -60,16 +59,102 @@ public func run_ArrayAppendSequence(_ N: Int) {
 // Append another array. Length of sequence known so
 // can pre-reserve capacity.
 @inline(never)
-public func run_ArrayAppendArray(_ N: Int) {
+public func run_ArrayAppendArrayOfInt(_ N: Int) {
   let other = Array(repeating: 1, count: 10_000)
   for _ in 0..<N {
     for _ in 0..<10 {
       var nums = [Int]()
+      for _ in 0..<8 {
+        nums += other
+      }
+    }
+  }
+}
+
+// Append another array. Length of sequence known so
+// can pre-reserve capacity.
+@inline(never)
+public func run_ArrayAppendStrings(_ N: Int) {
+  let other = stride(from: 0, to: 10_000, by: 1).map { "\($0)" }
+  for _ in 0..<N {
+    for _ in 0..<10 {
+      var nums = [String]()
+      // lower inner count due to string slowness
       for _ in 0..<4 {
-        // note, this uses += rather than append(contentsOf:),
-        // to ensure operator doesn't introduce inefficiency
         nums += other
       }
     }
   }
 }
+
+struct S<T,U> {
+  var x: T
+  var y: U
+}
+
+// Append another array. Length of sequence known so
+// 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)
+  for _ in 0..<N {
+    for _ in 0..<10 {
+      var nums = [S<Int,Double>]()
+      for _ in 0..<8 {
+        nums += other
+      }
+    }
+  }
+}
+
+// Append another array. Length of sequence known so
+// can pre-reserve capacity.
+@inline(never)
+public func run_ArrayAppendOptionals(_ N: Int) {
+  let other: [Int?] = Array(repeating: 1, count: 10_000)
+
+  for _ in 0..<N {
+    for _ in 0..<10 {
+      var nums = [Int?]()
+      for _ in 0..<8 {
+        nums += other
+      }
+    }
+  }
+}
+
+
+// Append a lazily-mapped array. Length of sequence known so
+// 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 }
+
+  for _ in 0..<N {
+    for _ in 0..<10 {
+      var nums = [Int]()
+      for _ in 0..<8 {
+        nums += other
+      }
+    }
+  }
+}
+
+
+// Append a Repeat collection. Length of sequence known so
+// can pre-reserve capacity, but no optimization points used.
+@inline(never)
+public func run_ArrayAppendRepeatCol(_ N: Int) {
+  let other = repeatElement(1, count: 10_000)
+
+  for _ in 0..<N {
+    for _ in 0..<10 {
+      var nums = [Int]()
+      for _ in 0..<8 {
+        nums += other
+      }
+    }
+  }
+}
+
+
diff --git a/benchmark/utils/main.swift b/benchmark/utils/main.swift
index 3be49b0997c5a..4269525fc60b6 100644
--- a/benchmark/utils/main.swift
+++ b/benchmark/utils/main.swift
@@ -107,7 +107,12 @@ precommitTests = [
   "ArrayAppend": run_ArrayAppend,
   "ArrayAppendReserved": run_ArrayAppendReserved,
   "ArrayAppendSequence": run_ArrayAppendSequence,
-  "ArrayAppendArray": run_ArrayAppendArray,
+  "ArrayAppendArrayOfInt": run_ArrayAppendArrayOfInt,
+  "ArrayAppendStrings": run_ArrayAppendStrings,
+  "ArrayAppendGenericStructs": run_ArrayAppendGenericStructs,
+  "ArrayAppendOptionals": run_ArrayAppendOptionals,
+  "ArrayAppendLazyMap": run_ArrayAppendLazyMap,
+  "ArrayAppendRepeatCol": run_ArrayAppendRepeatCol,
   "ArrayInClass": run_ArrayInClass,
   "ArrayLiteral": run_ArrayLiteral,
   "ArrayOfGenericPOD": run_ArrayOfGenericPOD,