diff -r 9214f8440c44 Objects/unicodeobject.c
--- a/Objects/unicodeobject.c	Sat Nov 10 14:52:10 2012 +0000
+++ b/Objects/unicodeobject.c	Sun Nov 11 10:40:55 2012 +0200
@@ -10882,6 +10882,7 @@
 {
     Py_ssize_t len;
     Py_uhash_t x;
+    unsigned char *p;
 
 #ifdef Py_DEBUG
     assert(_Py_HashSecret_Initialized);
@@ -10899,37 +10900,23 @@
         _PyUnicode_HASH(self) = 0;
         return 0;
     }
-
-    /* The hash function as a macro, gets expanded three times below. */
-#define HASH(P)                                            \
-    x ^= (Py_uhash_t) *P << 7;                             \
-    while (--len >= 0)                                     \
-        x = (_PyHASH_MULTIPLIER * x) ^ (Py_uhash_t) *P++;  \
-
+    p = PyUnicode_DATA(self);
     x = (Py_uhash_t) _Py_HashSecret.prefix;
-    switch (PyUnicode_KIND(self)) {
-    case PyUnicode_1BYTE_KIND: {
-        const unsigned char *c = PyUnicode_1BYTE_DATA(self);
-        HASH(c);
-        break;
-    }
-    case PyUnicode_2BYTE_KIND: {
-        const Py_UCS2 *s = PyUnicode_2BYTE_DATA(self);
-        HASH(s);
-        break;
-    }
-    default: {
-        Py_UCS4 *l;
-        assert(PyUnicode_KIND(self) == PyUnicode_4BYTE_KIND &&
-               "Impossible switch case in unicode_hash");
-        l = PyUnicode_4BYTE_DATA(self);
-        HASH(l);
-        break;
-    }
-    }
+    x ^= (Py_uhash_t) *p << 7;
+    len *= PyUnicode_KIND(self);
+    assert(_Py_IS_ALIGNED(p, sizeof(size_t)));
+    if (len >= sizeof(size_t)) {
+        size_t *q = (size_t *)p;
+        size_t *e = (size_t *)_Py_ALIGN_DOWN(p + len, sizeof(size_t));
+        while (q < e)
+            x = (_PyHASH_MULTIPLIER * x) ^ (Py_uhash_t) *q++;
+        len -= (unsigned char *)q - p;
+        p = (unsigned char *)q;
+    }
+    while (len--)
+        x = (_PyHASH_MULTIPLIER * x) ^ (Py_uhash_t) *p++;
     x ^= (Py_uhash_t) PyUnicode_GET_LENGTH(self);
     x ^= (Py_uhash_t) _Py_HashSecret.suffix;
-
     if (x == -1)
         x = -2;
     _PyUnicode_HASH(self) = x;