[benchmark] Unbreaking the complex expression in ByteSwap

Fixes: <rdar://problem/31543153>
whylovejp · May 17, 2017 · d818008 · d818008
1 parent 78768d8
commit d818008
Showing 1 changed file with 19 additions and 9 deletions.
diff --git a/benchmark/single-source/ByteSwap.swift b/benchmark/single-source/ByteSwap.swift
@@ -18,15 +18,25 @@ import TestsUtils
 
 // a naive O(n) implementation of byteswap.
 func byteswap_n(_ a: UInt64) -> UInt64 {
-  var result = ((a & 0x00000000000000FF) << 56)
-  result |=    ((a & 0x000000000000FF00) << 40)
-  result |=    ((a & 0x0000000000FF0000) << 24)
-  result |=    ((a & 0x00000000FF000000) <<  8)
-  result |=    ((a & 0x000000FF00000000) >>  8)
-  result |=    ((a & 0x0000FF0000000000) >> 24)
-  result |=    ((a & 0x00FF000000000000) >> 40)
-  result |=    ((a & 0xFF00000000000000) >> 56)
-  return result
+#if swift(>=4)
+  return ((a & 0x00000000000000FF) &<< 56) |
+         ((a & 0x000000000000FF00) &<< 40) |
+         ((a & 0x0000000000FF0000) &<< 24) |
+         ((a & 0x00000000FF000000) &<<  8) |
+         ((a & 0x000000FF00000000) &>>  8) |
+         ((a & 0x0000FF0000000000) &>> 24) |
+         ((a & 0x00FF000000000000) &>> 40) |
+         ((a & 0xFF00000000000000) &>> 56)
+#else
+  return ((a & 0x00000000000000FF) << 56) |
+         ((a & 0x000000000000FF00) << 40) |
+         ((a & 0x0000000000FF0000) << 24) |
+         ((a & 0x00000000FF000000) <<  8) |
+         ((a & 0x000000FF00000000) >>  8) |
+         ((a & 0x0000FF0000000000) >> 24) |
+         ((a & 0x00FF000000000000) >> 40) |
+         ((a & 0xFF00000000000000) >> 56)
+#endif
 }
 
 // a O(logn) implementation of byteswap.