   }
 }
 
-func benchmark_MutateBytes(_ N: Int, _ data_: Data) {
-  for _ in 0..<10000*N {
-    var data = data_
-    data.withUnsafeMutableBytes { (ptr: UnsafeMutablePointer<UInt8>) in
+@inline(never)
+func withUnsafeMutableBytes(_ N: Int, data: Data) {
+  for _ in 0..<10000*N {
+    var copy = data
+    copy.withUnsafeMutableBytes { (ptr: UnsafeMutablePointer<UInt8>) in
       // Mutate a byte
       ptr.pointee = 42
     }

    runFunction: { withUnsafeBytes($0, data: medium) }, tags: d),

  BenchmarkInfo(name: "DataMutateBytesSmall",
    runFunction: run_MutateBytesSmall, tags: d),
  BenchmarkInfo(name: "DataMutateBytesMedium",
    runFunction: run_MutateBytesMedium, tags: d),

  BenchmarkInfo(name: "DataCopyBytesSmall",
    runFunction: run_CopyBytesSmall, tags: d),

    copy.count = count
    copy.count = orig
  }
}

@inline(never)
