Fix for 32-bit platforms

Author: mdboom

Include/internal/pycore_runtime_init.h

@@ -27,6 +27,7 @@ extern "C" {
 #include "pycore_runtime_init_generated.h"  // _Py_bytes_characters_INIT
 #include "pycore_signal.h"        // _signals_RUNTIME_INIT
 #include "pycore_tracemalloc.h"   // _tracemalloc_runtime_state_INIT
+#include "pycore_tuple.h"         // _PyTuple_HASH_EMPTY
 
 
 extern PyTypeObject _PyExc_MemoryError;
@@ -106,9 +107,7 @@ extern PyTypeObject _PyExc_MemoryError;
                 }, \
                 .tuple_empty = { \
                     .ob_base = _PyVarObject_HEAD_INIT(&PyTuple_Type, 0), \
-                    /* Using the hash constants in tupleobject.c
-                       _PyHASH_XXPRIME_5 + (_PyHASH_XXPRIME_5 ^ 3527539UL) */ \
-                    .ob_hash = 5740354900026072187, \
+                    .ob_hash = _PyTuple_HASH_EMPTY, \
                 }, \
                 .hamt_bitmap_node_empty = { \
                     .ob_base = _PyVarObject_HEAD_INIT(&_PyHamt_BitmapNode_Type, 0), \

Include/internal/pycore_tuple.h

@@ -47,6 +47,25 @@ _PyTuple_Recycle(PyObject *op)
     }
 }
 
+/* Below are the official constants from the xxHash specification. Optimizing
+   compilers should emit a single "rotate" instruction for the
+   _PyTuple_HASH_XXROTATE() expansion. If that doesn't happen for some important
+   platform, the macro could be changed to expand to a platform-specific rotate
+   spelling instead.
+*/
+#if SIZEOF_PY_UHASH_T > 4
+#define _PyTuple_HASH_XXPRIME_1 ((Py_uhash_t)11400714785074694791ULL)
+#define _PyTuple_HASH_XXPRIME_2 ((Py_uhash_t)14029467366897019727ULL)
+#define _PyTuple_HASH_XXPRIME_5 ((Py_uhash_t)2870177450012600261ULL)
+#define _PyTuple_HASH_XXROTATE(x) ((x << 31) | (x >> 33))  /* Rotate left 31 bits */
+#else
+#define _PyTuple_HASH_XXPRIME_1 ((Py_uhash_t)2654435761UL)
+#define _PyTuple_HASH_XXPRIME_2 ((Py_uhash_t)2246822519UL)
+#define _PyTuple_HASH_XXPRIME_5 ((Py_uhash_t)374761393UL)
+#define _PyTuple_HASH_XXROTATE(x) ((x << 13) | (x >> 19))  /* Rotate left 13 bits */
+#endif
+#define _PyTuple_HASH_EMPTY (_PyTuple_HASH_XXPRIME_5 + (_PyTuple_HASH_XXPRIME_5 ^ 3527539UL))
+
 #ifdef __cplusplus
 }
 #endif

Objects/tupleobject.c

@@ -301,23 +301,8 @@ tuple_repr(PyObject *self)
    For the xxHash specification, see
    https://github.com/Cyan4973/xxHash/blob/master/doc/xxhash_spec.md
 
-   Below are the official constants from the xxHash specification. Optimizing
-   compilers should emit a single "rotate" instruction for the
-   _PyHASH_XXROTATE() expansion. If that doesn't happen for some important
-   platform, the macro could be changed to expand to a platform-specific rotate
-   spelling instead.
+   The constants for the hard function are defined in pycore_tuple.h.
 */
-#if SIZEOF_PY_UHASH_T > 4
-#define _PyHASH_XXPRIME_1 ((Py_uhash_t)11400714785074694791ULL)
-#define _PyHASH_XXPRIME_2 ((Py_uhash_t)14029467366897019727ULL)
-#define _PyHASH_XXPRIME_5 ((Py_uhash_t)2870177450012600261ULL)
-#define _PyHASH_XXROTATE(x) ((x << 31) | (x >> 33))  /* Rotate left 31 bits */
-#else
-#define _PyHASH_XXPRIME_1 ((Py_uhash_t)2654435761UL)
-#define _PyHASH_XXPRIME_2 ((Py_uhash_t)2246822519UL)
-#define _PyHASH_XXPRIME_5 ((Py_uhash_t)374761393UL)
-#define _PyHASH_XXROTATE(x) ((x << 13) | (x >> 19))  /* Rotate left 13 bits */
-#endif
 
 static Py_hash_t
 tuple_hash(PyObject *op)
@@ -330,19 +315,19 @@ tuple_hash(PyObject *op)
 
     Py_ssize_t len = Py_SIZE(v);
     PyObject **item = v->ob_item;
-    Py_uhash_t acc = _PyHASH_XXPRIME_5;
+    Py_uhash_t acc = _PyTuple_HASH_XXPRIME_5;
     for (Py_ssize_t i = 0; i < len; i++) {
         Py_uhash_t lane = PyObject_Hash(item[i]);
         if (lane == (Py_uhash_t)-1) {
             return -1;
         }
-        acc += lane * _PyHASH_XXPRIME_2;
-        acc = _PyHASH_XXROTATE(acc);
-        acc *= _PyHASH_XXPRIME_1;
+        acc += lane * _PyTuple_HASH_XXPRIME_2;
+        acc = _PyTuple_HASH_XXROTATE(acc);
+        acc *= _PyTuple_HASH_XXPRIME_1;
     }
 
     /* Add input length, mangled to keep the historical value of hash(()). */
-    acc += len ^ (_PyHASH_XXPRIME_5 ^ 3527539UL);
+    acc += len ^ (_PyTuple_HASH_XXPRIME_5 ^ 3527539UL);
 
     if (acc == (Py_uhash_t)-1) {
         acc = 1546275796;