bpo-26163: Frozenset hash improvement (GH-5194) (#5198) · python/cpython@e7dbd06 (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
@@ -790,6 +790,7 @@ frozenset_hash(PyObject *self)
790	790	hash ^= ((Py_uhash_t)PySet_GET_SIZE(self) + 1) * 1927868237UL;
791	791
792	792	/* Disperse patterns arising in nested frozensets */
	793	+hash ^= (hash >> 11) ^ (~hash >> 25);
793	794	hash = hash * 69069U + 907133923UL;
794	795
795	796	/* -1 is reserved as an error code */