 
 @inline(never)
 public func run_ByteSwap(_ N: Int) {
-  for _ in 1...100*N {
+  var s: UInt64 = 0
+  for _ in 1...10000*N {
     // Check some results.
-    CheckResults(byteswap_logn(byteswap_n(2457)) == 2457)
-    CheckResults(byteswap_logn(byteswap_n(9129)) == 9129)
-    CheckResults(byteswap_logn(byteswap_n(3333)) == 3333)
+    let x : UInt64 = UInt64(getInt(0))
+    s = s &+ byteswap_logn(byteswap_n(x &+ 2457))
+          &+ byteswap_logn(byteswap_n(x &+ 9129))
+          &+ byteswap_logn(byteswap_n(x &+ 3333))
   }
+  CheckResults(s == (2457 &+ 9129 &+ 3333) &* 10000 &* N)
 }

}

// a O(logn) implementation of byteswap.
func byteswap_logn(_ a: UInt64) -> UInt64 {
  var a = a
  a = (a & 0x00000000FFFFFFFF) << 32 | (a & 0xFFFFFFFF00000000) >> 32

import TestsUtils

// a naive O(n) implementation of byteswap.
@inline(never)
func byteswap_n(_ a: UInt64) -> UInt64 {
#if swift(>=4)
  return ((a & 0x00000000000000FF) &<< 56) |
