bpo-26163: Frozenset hash improvement (#5194) · python/cpython@b44c516 (original) (raw)

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Misc/NEWS.d/next/Core and Builtins

2 files changed

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Original file line number	Diff line number	Diff line change
@@ -0,0 +1,2 @@
	1	+Improved frozenset() hash to create more distinct hash values when faced
	2	+with datasets containing many similar values.

Original file line number	Diff line number	Diff line change
@@ -795,6 +795,7 @@ frozenset_hash(PyObject *self)
795	795	hash ^= ((Py_uhash_t)PySet_GET_SIZE(self) + 1) * 1927868237UL;
796	796
797	797	/* Disperse patterns arising in nested frozensets */
	798	+hash ^= (hash >> 11) ^ (~hash >> 25);
798	799	hash = hash * 69069U + 907133923UL;
799	800
800	801	/* -1 is reserved as an error code */