Fix test on 32-bit

Author: vstinner

Lib/test/test_capi/test_hash.py

@@ -4,7 +4,8 @@
 _testcapi = import_helper.import_module('_testcapi')
 
 
-SIZEOF_PY_HASH_T = _testcapi.SIZEOF_VOID_P
+SIZEOF_VOID_P = _testcapi.SIZEOF_VOID_P
+SIZEOF_PY_HASH_T = SIZEOF_VOID_P
 
 
 class CAPITest(unittest.TestCase):
@@ -36,10 +37,8 @@ def test_hash_pointer(self):
         # Test PyHash_Pointer()
         hash_pointer = _testcapi.hash_pointer
 
-        HASH_BITS = 8 * _testcapi.SIZEOF_VOID_P
-        UHASH_T_MASK = ((2 ** HASH_BITS) - 1)
-        HASH_T_MAX = (2 ** (HASH_BITS - 1) - 1)
-        MAX_PTR = UHASH_T_MASK
+        UHASH_T_MASK = ((2 ** (8 * SIZEOF_PY_HASH_T)) - 1)
+        HASH_T_MAX = (2 ** (8 * SIZEOF_PY_HASH_T - 1) - 1)
 
         def uhash_to_hash(x):
             # Convert unsigned Py_uhash_t to signed Py_hash_t
@@ -49,12 +48,25 @@ def uhash_to_hash(x):
                 x = (~x) + 1
             return x
 
-        # Known values
+        # PyHash_Pointer() rotates the pointer bits by 4 bits to the right
+        if SIZEOF_VOID_P == 8:
+            self.assertEqual(hash_pointer(0xABCDEF1234567890),
+                             0x0ABCDEF123456789)
+            self.assertEqual(hash_pointer(0x1234567890ABCDEF),
+                             uhash_to_hash(0xF1234567890ABCDE))
+            self.assertEqual(hash_pointer(0xFEE4ABEDD1CECA5E),
+                             uhash_to_hash(0xEFEE4ABEDD1CECA5))
+        else:
+            self.assertEqual(hash_pointer(0x12345678),
+                             uhash_to_hash(0x81234567))
+            self.assertEqual(hash_pointer(0x1234ABCD),
+                             uhash_to_hash(0xD1234ABC))
+            self.assertEqual(hash_pointer(0xDEADCAFE),
+                             uhash_to_hash(0xEDEADCAF))
+
+        # PyHash_Pointer(NULL) returns 0
         self.assertEqual(hash_pointer(0), 0)
-        self.assertEqual(hash_pointer(MAX_PTR), -2)
-        self.assertEqual(hash_pointer(0xABCDEF1234567890),
-                         0x0ABCDEF123456789)
-        self.assertEqual(hash_pointer(0x1234567890ABCDEF),
-                         uhash_to_hash(0xF1234567890ABCDE))
-        self.assertEqual(hash_pointer(0xFEE4ABEDD1CECA5E),
-                         uhash_to_hash(0xEFEE4ABEDD1CECA5))
+
+        # PyHash_Pointer((void*)(uintptr_t)-1) doesn't return -1 but -2
+        VOID_P_MAX = -1 & (2 ** (8 * SIZEOF_VOID_P) - 1)
+        self.assertEqual(hash_pointer(VOID_P_MAX), -2)