diff --git a/Doc/c-api/hash.rst b/Doc/c-api/hash.rst index ddf0b3e15db..7345a048a41 100644 --- a/Doc/c-api/hash.rst +++ b/Doc/c-api/hash.rst @@ -29,6 +29,12 @@ See also the :c:member:`PyTypeObject.tp_hash` member and :ref:`numeric-hash`. .. versionadded:: 3.13 +.. c:macro:: PyHASH_MULTIPLIER + + Prime multiplier used in string and various other hashes. + + .. versionadded:: 3.13 + .. c:macro:: PyHASH_INF The hash value returned for a positive infinity. diff --git a/Include/cpython/pyhash.h b/Include/cpython/pyhash.h index 2f8e12c1423..825c034a8d8 100644 --- a/Include/cpython/pyhash.h +++ b/Include/cpython/pyhash.h @@ -3,7 +3,7 @@ #endif /* Prime multiplier used in string and various other hashes. */ -#define _PyHASH_MULTIPLIER 1000003UL /* 0xf4243 */ +#define PyHASH_MULTIPLIER 1000003UL /* 0xf4243 */ /* Parameters used for the numeric hash implementation. See notes for _Py_HashDouble in Python/pyhash.c. Numeric hashes are based on @@ -17,9 +17,10 @@ #define PyHASH_MODULUS (((size_t)1 << _PyHASH_BITS) - 1) #define PyHASH_INF 314159 -#define PyHASH_IMAG _PyHASH_MULTIPLIER +#define PyHASH_IMAG PyHASH_MULTIPLIER /* Aliases kept for backward compatibility with Python 3.12 */ +#define _PyHASH_MULTIPLIER PyHASH_MULTIPLIER #define _PyHASH_BITS PyHASH_BITS #define _PyHASH_MODULUS PyHASH_MODULUS #define _PyHASH_INF PyHASH_INF diff --git a/Misc/NEWS.d/next/C API/2024-05-20-10-35-22.gh-issue-111389.a6axBk.rst b/Misc/NEWS.d/next/C API/2024-05-20-10-35-22.gh-issue-111389.a6axBk.rst new file mode 100644 index 00000000000..f47662f2e0a --- /dev/null +++ b/Misc/NEWS.d/next/C API/2024-05-20-10-35-22.gh-issue-111389.a6axBk.rst @@ -0,0 +1,2 @@ +Add :c:macro:`PyHASH_MULTIPLIER` constant: prime multiplier used in string +and various other hashes. Patch by Victor Stinner. diff --git a/Objects/codeobject.c b/Objects/codeobject.c index 23fc8a76fd2..55b512b3f1a 100644 --- a/Objects/codeobject.c +++ b/Objects/codeobject.c @@ -2020,7 +2020,7 @@ code_hash(PyCodeObject *co) Py_uhash_t uhash = 20221211; #define SCRAMBLE_IN(H) do { \ uhash ^= (Py_uhash_t)(H); \ - uhash *= _PyHASH_MULTIPLIER; \ + uhash *= PyHASH_MULTIPLIER; \ } while (0) #define SCRAMBLE_IN_HASH(EXPR) do { \ Py_hash_t h = PyObject_Hash(EXPR); \ diff --git a/Python/optimizer.c b/Python/optimizer.c index 8be2c0ffbd7..9dddc43776f 100644 --- a/Python/optimizer.c +++ b/Python/optimizer.c @@ -1496,7 +1496,7 @@ address_to_hash(void *ptr) { uintptr_t addr = (uintptr_t)ptr; for (int i = 0; i < SIZEOF_VOID_P; i++) { uhash ^= addr & 255; - uhash *= (uint64_t)_PyHASH_MULTIPLIER; + uhash *= (uint64_t)PyHASH_MULTIPLIER; addr >>= 8; } return uhash; diff --git a/Python/pyhash.c b/Python/pyhash.c index d508d78092a..5263622ff31 100644 --- a/Python/pyhash.c +++ b/Python/pyhash.c @@ -263,12 +263,12 @@ fnv(const void *src, Py_ssize_t len) x ^= (Py_uhash_t) *p << 7; while (blocks--) { PY_UHASH_CPY(block.bytes, p); - x = (_PyHASH_MULTIPLIER * x) ^ block.value; + x = (PyHASH_MULTIPLIER * x) ^ block.value; p += SIZEOF_PY_UHASH_T; } /* add remainder */ for (; remainder > 0; remainder--) - x = (_PyHASH_MULTIPLIER * x) ^ (Py_uhash_t) *p++; + x = (PyHASH_MULTIPLIER * x) ^ (Py_uhash_t) *p++; x ^= (Py_uhash_t) len; x ^= (Py_uhash_t) _Py_HashSecret.fnv.suffix; if (x == (Py_uhash_t) -1) { diff --git a/Python/tracemalloc.c b/Python/tracemalloc.c index e3ec72062f6..fee7dd0e56d 100644 --- a/Python/tracemalloc.c +++ b/Python/tracemalloc.c @@ -312,7 +312,7 @@ traceback_hash(traceback_t *traceback) /* code based on tuplehash() of Objects/tupleobject.c */ Py_uhash_t x, y; /* Unsigned for defined overflow behavior. */ int len = traceback->nframe; - Py_uhash_t mult = _PyHASH_MULTIPLIER; + Py_uhash_t mult = PyHASH_MULTIPLIER; frame_t *frame; x = 0x345678UL;