diff -r 024827a9db64 Modules/_ctypes/cfield.c
--- a/Modules/_ctypes/cfield.c	Fri Jun 24 20:52:27 2011 +0200
+++ b/Modules/_ctypes/cfield.c	Fri Jun 24 22:40:15 2011 -0700
@@ -429,12 +429,7 @@
 #define LOW_BIT(x)  ((x) & 0xFFFF)
 #define NUM_BITS(x) ((x) >> 16)
 
-/* This seems nore a compiler issue than a Windows/non-Windows one */
-#ifdef MS_WIN32
-#  define BIT_MASK(size) ((1 << NUM_BITS(size))-1)
-#else
-#  define BIT_MASK(size) ((1LL << NUM_BITS(size))-1)
-#endif
+#define BIT_MASK(size) ((1LL << NUM_BITS(size))-1)
 
 /* This macro CHANGES the first parameter IN PLACE. For proper sign handling,
    we must first shift left, then right.
@@ -462,17 +457,6 @@
       ( (v & 0x00FF0000) >>  8 ) |  \
       ( ((v >> 24) & 0xFF)) )
 
-#ifdef _MSC_VER
-#define SWAP_8(v)                               \
-    ( ( (v & 0x00000000000000FFL) << 56 ) |  \
-      ( (v & 0x000000000000FF00L) << 40 ) |  \
-      ( (v & 0x0000000000FF0000L) << 24 ) |  \
-      ( (v & 0x00000000FF000000L) <<  8 ) |  \
-      ( (v & 0x000000FF00000000L) >>  8 ) |  \
-      ( (v & 0x0000FF0000000000L) >> 24 ) |  \
-      ( (v & 0x00FF000000000000L) >> 40 ) |  \
-      ( ((v >> 56) & 0xFF)) )
-#else
 #define SWAP_8(v)                               \
     ( ( (v & 0x00000000000000FFLL) << 56 ) |  \
       ( (v & 0x000000000000FF00LL) << 40 ) |  \
@@ -482,7 +466,6 @@
       ( (v & 0x0000FF0000000000LL) >> 24 ) |  \
       ( (v & 0x00FF000000000000LL) >> 40 ) |  \
       ( ((v >> 56) & 0xFF)) )
-#endif
 
 #define SWAP_INT SWAP_4