diff -r 0d41a1b4c4fe Modules/_struct.c
--- a/Modules/_struct.c	Mon Oct 08 07:46:11 2012 +0200
+++ b/Modules/_struct.c	Mon Oct 08 20:17:25 2012 +0300
@@ -1199,12 +1199,11 @@
     case '!': /* Network byte order is big-endian */
         return bigendian_table;
     case '=': { /* Host byte order -- different from native in alignment! */
-        int n = 1;
-        char *p = (char *) &n;
-        if (*p == 1)
-            return lilendian_table;
-        else
-            return bigendian_table;
+#ifdef WORDS_BIGENDIAN
+        return bigendian_table;
+#else
+        return lilendian_table;
+#endif
     }
     default:
         --*pfmt; /* Back out of pointer increment */
@@ -2088,13 +2087,13 @@
 
     /* Check endian and swap in faster functions */
     {
-        int one = 1;
         formatdef *native = native_table;
         formatdef *other, *ptr;
-        if ((int)*(unsigned char*)&one)
-            other = lilendian_table;
-        else
-            other = bigendian_table;
+#ifdef WORDS_BIGENDIAN
+        other = bigendian_table;
+#else
+        other = lilendian_table;
+#endif
         /* Scan through the native table, find a matching
            entry in the endian table and swap in the
            native implementations whenever possible
diff -r 0d41a1b4c4fe Objects/longobject.c
--- a/Objects/longobject.c	Mon Oct 08 07:46:11 2012 +0200
+++ b/Objects/longobject.c	Mon Oct 08 20:17:25 2012 +0300
@@ -988,7 +988,11 @@
  * rewritten to use the newer PyLong_{As,From}ByteArray API.
  */
 
-#define IS_LITTLE_ENDIAN (int)*(unsigned char*)&one
+#ifdef WORDS_BIGENDIAN
+#define IS_LITTLE_ENDIAN 0
+#else
+#define IS_LITTLE_ENDIAN 1
+#endif
 #define PY_ABS_LLONG_MIN (0-(unsigned PY_LONG_LONG)PY_LLONG_MIN)
 
 /* Create a new long int object from a C PY_LONG_LONG int. */
@@ -1141,7 +1145,6 @@
 {
     PyLongObject *v;
     PY_LONG_LONG bytes;
-    int one = 1;
     int res;
 
     if (vv == NULL) {
@@ -1193,7 +1196,6 @@
 {
     PyLongObject *v;
     unsigned PY_LONG_LONG bytes;
-    int one = 1;
     int res;
 
     if (vv == NULL) {
diff -r 0d41a1b4c4fe Objects/stringlib/codecs.h
--- a/Objects/stringlib/codecs.h	Mon Oct 08 07:46:11 2012 +0200
+++ b/Objects/stringlib/codecs.h	Mon Oct 08 20:17:25 2012 +0300
@@ -47,18 +47,7 @@
                     unsigned long value = *(unsigned long *) _s;
                     if (value & ASCII_CHAR_MASK)
                         break;
-#ifdef BYTEORDER_IS_LITTLE_ENDIAN
-                    _p[0] = (STRINGLIB_CHAR)(value & 0xFFu);
-                    _p[1] = (STRINGLIB_CHAR)((value >> 8) & 0xFFu);
-                    _p[2] = (STRINGLIB_CHAR)((value >> 16) & 0xFFu);
-                    _p[3] = (STRINGLIB_CHAR)((value >> 24) & 0xFFu);
-# if SIZEOF_LONG == 8
-                    _p[4] = (STRINGLIB_CHAR)((value >> 32) & 0xFFu);
-                    _p[5] = (STRINGLIB_CHAR)((value >> 40) & 0xFFu);
-                    _p[6] = (STRINGLIB_CHAR)((value >> 48) & 0xFFu);
-                    _p[7] = (STRINGLIB_CHAR)((value >> 56) & 0xFFu);
-# endif
-#else
+#ifdef WORDS_BIGENDIAN
 # if SIZEOF_LONG == 8
                     _p[0] = (STRINGLIB_CHAR)((value >> 56) & 0xFFu);
                     _p[1] = (STRINGLIB_CHAR)((value >> 48) & 0xFFu);
@@ -74,6 +63,17 @@
                     _p[2] = (STRINGLIB_CHAR)((value >> 8) & 0xFFu);
                     _p[3] = (STRINGLIB_CHAR)(value & 0xFFu);
 # endif
+#else
+                    _p[0] = (STRINGLIB_CHAR)(value & 0xFFu);
+                    _p[1] = (STRINGLIB_CHAR)((value >> 8) & 0xFFu);
+                    _p[2] = (STRINGLIB_CHAR)((value >> 16) & 0xFFu);
+                    _p[3] = (STRINGLIB_CHAR)((value >> 24) & 0xFFu);
+# if SIZEOF_LONG == 8
+                    _p[4] = (STRINGLIB_CHAR)((value >> 32) & 0xFFu);
+                    _p[5] = (STRINGLIB_CHAR)((value >> 40) & 0xFFu);
+                    _p[6] = (STRINGLIB_CHAR)((value >> 48) & 0xFFu);
+                    _p[7] = (STRINGLIB_CHAR)((value >> 56) & 0xFFu);
+# endif
 #endif
                     _s += SIZEOF_LONG;
                     _p += SIZEOF_LONG;
@@ -454,10 +454,10 @@
     const unsigned char *q = *inptr;
     STRINGLIB_CHAR *p = dest + *outpos;
     /* Offsets from q for retrieving byte pairs in the right order. */
-#ifdef BYTEORDER_IS_LITTLE_ENDIAN
+#ifdef WORDS_BIGENDIAN
+    int ihi = !native_ordering, ilo = !!native_ordering;
+#else
     int ihi = !!native_ordering, ilo = !native_ordering;
-#else
-    int ihi = !native_ordering, ilo = !!native_ordering;
 #endif
     --e;
 
@@ -485,7 +485,17 @@
                     block = SWAB(block);
 #endif
                 }
-#ifdef BYTEORDER_IS_LITTLE_ENDIAN
+#ifdef WORDS_BIGENDIAN
+# if SIZEOF_LONG == 4
+                p[0] = (STRINGLIB_CHAR)(block >> 16);
+                p[1] = (STRINGLIB_CHAR)(block & 0xFFFFu);
+# elif SIZEOF_LONG == 8
+                p[0] = (STRINGLIB_CHAR)(block >> 48);
+                p[1] = (STRINGLIB_CHAR)((block >> 32) & 0xFFFFu);
+                p[2] = (STRINGLIB_CHAR)((block >> 16) & 0xFFFFu);
+                p[3] = (STRINGLIB_CHAR)(block & 0xFFFFu);
+# endif
+#else
 # if SIZEOF_LONG == 4
                 p[0] = (STRINGLIB_CHAR)(block & 0xFFFFu);
                 p[1] = (STRINGLIB_CHAR)(block >> 16);
@@ -495,16 +505,6 @@
                 p[2] = (STRINGLIB_CHAR)((block >> 32) & 0xFFFFu);
                 p[3] = (STRINGLIB_CHAR)(block >> 48);
 # endif
-#else
-# if SIZEOF_LONG == 4
-                p[0] = (STRINGLIB_CHAR)(block >> 16);
-                p[1] = (STRINGLIB_CHAR)(block & 0xFFFFu);
-# elif SIZEOF_LONG == 8
-                p[0] = (STRINGLIB_CHAR)(block >> 48);
-                p[1] = (STRINGLIB_CHAR)((block >> 32) & 0xFFFFu);
-                p[2] = (STRINGLIB_CHAR)((block >> 16) & 0xFFFFu);
-                p[3] = (STRINGLIB_CHAR)(block & 0xFFFFu);
-# endif
 #endif
                 _q += SIZEOF_LONG;
                 p += SIZEOF_LONG / 2;
diff -r 0d41a1b4c4fe Objects/unicodeobject.c
--- a/Objects/unicodeobject.c	Mon Oct 08 07:46:11 2012 +0200
+++ b/Objects/unicodeobject.c	Mon Oct 08 20:17:25 2012 +0300
@@ -47,14 +47,6 @@
 #include <windows.h>
 #endif
 
-/* Endianness switches; defaults to little endian */
-
-#ifdef WORDS_BIGENDIAN
-# define BYTEORDER_IS_BIG_ENDIAN
-#else
-# define BYTEORDER_IS_LITTLE_ENDIAN
-#endif
-
 /* --- Globals ------------------------------------------------------------
 
    The globals are initialized by the _PyUnicode_Init() API and should
@@ -4813,10 +4805,10 @@
     int bo = 0;       /* assume native ordering by default */
     const char *errmsg = "";
     /* Offsets from q for retrieving bytes in the right order. */
-#ifdef BYTEORDER_IS_LITTLE_ENDIAN
+#ifdef WORDS_BIGENDIAN
+    int iorder[] = {3, 2, 1, 0};
+#else
     int iorder[] = {0, 1, 2, 3};
-#else
-    int iorder[] = {3, 2, 1, 0};
 #endif
     PyObject *errorHandler = NULL;
     PyObject *exc = NULL;
@@ -4835,7 +4827,16 @@
         if (size >= 4) {
             const Py_UCS4 bom = (q[iorder[3]] << 24) | (q[iorder[2]] << 16) |
                 (q[iorder[1]] << 8) | q[iorder[0]];
-#ifdef BYTEORDER_IS_LITTLE_ENDIAN
+#ifdef WORDS_BIGENDIAN
+            if (bom == 0x0000FEFF) {
+                q += 4;
+                bo = 1;
+            }
+            else if (bom == 0xFFFE0000) {
+                q += 4;
+                bo = -1;
+            }
+#else
             if (bom == 0x0000FEFF) {
                 q += 4;
                 bo = -1;
@@ -4844,15 +4845,6 @@
                 q += 4;
                 bo = 1;
             }
-#else
-            if (bom == 0x0000FEFF) {
-                q += 4;
-                bo = 1;
-            }
-            else if (bom == 0xFFFE0000) {
-                q += 4;
-                bo = -1;
-            }
 #endif
         }
     }
@@ -4949,10 +4941,10 @@
     unsigned char *p;
     Py_ssize_t nsize, i;
     /* Offsets from p for storing byte pairs in the right order. */
-#ifdef BYTEORDER_IS_LITTLE_ENDIAN
+#ifdef WORDS_BIGENDIAN
+    int iorder[] = {3, 2, 1, 0};
+#else
     int iorder[] = {0, 1, 2, 3};
-#else
-    int iorder[] = {3, 2, 1, 0};
 #endif
 
 #define STORECHAR(CH)                           \
@@ -5092,10 +5084,10 @@
         return unicode_empty;
     }
 
-#ifdef BYTEORDER_IS_LITTLE_ENDIAN
+#ifdef WORDS_BIGENDIAN
+    native_ordering = bo >= 0;
+#else
     native_ordering = bo <= 0;
-#else
-    native_ordering = bo >= 0;
 #endif
 
     /* Note: size will always be longer than the resulting Unicode
diff -r 0d41a1b4c4fe Python/marshal.c
--- a/Python/marshal.c	Mon Oct 08 07:46:11 2012 +0200
+++ b/Python/marshal.c	Mon Oct 08 20:17:25 2012 +0300
@@ -570,17 +570,15 @@
         result = PyLong_FromLong(x);
 #else
         unsigned char buf[8];
-        int one = 1;
-        int is_little_endian = (int)*(char*)&one;
-        if (is_little_endian) {
-            memcpy(buf, &lo4, 4);
-            memcpy(buf+4, &hi4, 4);
-        }
-        else {
-            memcpy(buf, &hi4, 4);
-            memcpy(buf+4, &lo4, 4);
-        }
-        result = _PyLong_FromByteArray(buf, 8, is_little_endian, 1);
+#ifdef WORDS_BIGENDIAN
+        memcpy(buf, &hi4, 4);
+        memcpy(buf+4, &lo4, 4);
+        result = _PyLong_FromByteArray(buf, 8, 0, 1);
+#else
+        memcpy(buf, &lo4, 4);
+        memcpy(buf+4, &hi4, 4);
+        result = _PyLong_FromByteArray(buf, 8, 1, 1);
+#endif
 #endif
     }
     return result;
diff -r 0d41a1b4c4fe Python/sysmodule.c
--- a/Python/sysmodule.c	Mon Oct 08 07:46:11 2012 +0200
+++ b/Python/sysmodule.c	Mon Oct 08 20:17:25 2012 +0300
@@ -1561,7 +1561,6 @@
 _PySys_Init(void)
 {
     PyObject *m, *v, *sysdict, *version_info;
-    char *s;
 
     m = PyModule_Create(&sysmodule);
     if (m == NULL)
@@ -1638,20 +1637,13 @@
                         PyLong_FromLong(0x10FFFF));
     SET_SYS_FROM_STRING("builtin_module_names",
                         list_builtin_module_names());
-    {
-        /* Assumes that longs are at least 2 bytes long.
-           Should be safe! */
-        unsigned long number = 1;
-        char *value;
-
-        s = (char *) &number;
-        if (s[0] == 0)
-            value = "big";
-        else
-            value = "little";
-        SET_SYS_FROM_STRING("byteorder",
-                            PyUnicode_FromString(value));
-    }
+#ifdef WORDS_BIGENDIAN
+    SET_SYS_FROM_STRING("byteorder",
+                        PyUnicode_FromString("big"));
+#else
+    SET_SYS_FROM_STRING("byteorder",
+                        PyUnicode_FromString("little"));
+#endif
 #ifdef MS_COREDLL
     SET_SYS_FROM_STRING("dllhandle",
                         PyLong_FromVoidPtr(PyWin_DLLhModule));