2014-01-09: precompute 2**32

precompute 2**32

diff --git a/examples/tinyenc.w b/examples/tinyenc.w
--- a/examples/tinyenc.w
+++ b/examples/tinyenc.w
@@ -11,10 +11,11 @@ use-syntax : ice-9 syncase
 ; http://en.wikipedia.org/wiki/Tiny_Encryption_Algorithm#toctitle
 
 define delta #x9e3779b9
+define uint32-max : integer-expt 2 32
 
 define : uint32 number
   . "ensure that the number fits a uint32"
-  modulo number : integer-expt 2 32
+  modulo number uint32-limit
 
 define : v0change k0 v1 sum k1
          logxor