diff --git a/Lib/test/test_long.py b/Lib/test/test_long.py
index f336d49fa4f008..c206c9e02a9fbc 100644
--- a/Lib/test/test_long.py
+++ b/Lib/test/test_long.py
@@ -1693,5 +1693,22 @@ class MyInt(int):
# GH-117195 -- This shouldn't crash
object.__sizeof__(1)
+ def test_hash(self):
+ # gh-136599
+ self.assertEqual(hash(-1), -2)
+ self.assertEqual(hash(0), 0)
+ self.assertEqual(hash(10), 10)
+
+ self.assertEqual(hash(sys.hash_info.modulus - 2), sys.hash_info.modulus - 2)
+ self.assertEqual(hash(sys.hash_info.modulus - 1), sys.hash_info.modulus - 1)
+ self.assertEqual(hash(sys.hash_info.modulus), 0)
+ self.assertEqual(hash(sys.hash_info.modulus + 1), 1)
+
+ self.assertEqual(hash(-sys.hash_info.modulus - 2), -2)
+ self.assertEqual(hash(-sys.hash_info.modulus - 1), -2)
+ self.assertEqual(hash(-sys.hash_info.modulus), 0)
+ self.assertEqual(hash(-sys.hash_info.modulus + 1), - (sys.hash_info.modulus - 1))
+
+
if __name__ == "__main__":
unittest.main()
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-07-13-21-21-17.gh-issue-136599.sLhm2O.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-07-13-21-21-17.gh-issue-136599.sLhm2O.rst
new file mode 100644
index 00000000000000..9bcb13f9e20caf
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-07-13-21-21-17.gh-issue-136599.sLhm2O.rst
@@ -0,0 +1 @@
+Improve performance of :class:`int` hash calculations.
diff --git a/Objects/longobject.c b/Objects/longobject.c
index 581db10b54ab57..e5e36cdb01b0eb 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -3676,7 +3676,20 @@ long_hash(PyObject *obj)
}
i = _PyLong_DigitCount(v);
sign = _PyLong_NonCompactSign(v);
- x = 0;
+
+ // unroll first two digits
+#if ( PyHASH_BITS > PyLong_SHIFT )
+ assert(i>=2);
+ --i;
+ x = v->long_value.ob_digit[i];
+ assert(x < _PyHASH_MODULUS);
+#endif
+#if ( PyHASH_BITS > (2 * PyLong_SHIFT) )
+ --i;
+ x = ((x << PyLong_SHIFT));
+ x += v->long_value.ob_digit[i];
+ assert(x < _PyHASH_MODULUS);
+#endif
while (--i >= 0) {
/* Here x is a quantity in the range [0, _PyHASH_MODULUS); we
want to compute x * 2**PyLong_SHIFT + v->long_value.ob_digit[i] modulo
pFad - Phonifier reborn
Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.
Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.
Alternative Proxies:
Alternative Proxy
pFad Proxy
pFad v3 Proxy
pFad v4 Proxy