Consolidate the occurrances of the prime used as the multiplier when hashing.

This commit is contained in:
Gregory P. Smith 2012-01-14 15:45:13 -08:00
commit f5b62a9b31
4 changed files with 7 additions and 4 deletions

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@ -131,6 +131,9 @@ Used in: PY_LONG_LONG
#endif
#endif
/* Prime multiplier used in string and various other hashes. */
#define _PyHASH_MULTIPLIER 1000003 /* 0xf4243 */
/* Parameters used for the numeric hash implementation. See notes for
_Py_HashDouble in Objects/object.c. Numeric hashes are based on
reduction modulo the prime 2**_PyHASH_BITS - 1. */
@ -143,7 +146,7 @@ Used in: PY_LONG_LONG
#define _PyHASH_MODULUS (((size_t)1 << _PyHASH_BITS) - 1)
#define _PyHASH_INF 314159
#define _PyHASH_NAN 0
#define _PyHASH_IMAG 1000003UL
#define _PyHASH_IMAG _PyHASH_MULTIPLIER
/* uintptr_t is the C9X name for an unsigned integral type such that a
* legitimate void* can be cast to uintptr_t and then back to void* again

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@ -761,7 +761,7 @@ _Py_HashBytes(unsigned char *p, Py_ssize_t len)
x = (Py_uhash_t) *p << 7;
for (i = 0; i < len; i++)
x = (1000003U * x) ^ (Py_uhash_t) *p++;
x = (_PyHASH_MULTIPLIER * x) ^ (Py_uhash_t) *p++;
x ^= (Py_uhash_t) len;
if (x == -1)
x = -2;

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@ -316,7 +316,7 @@ tuplehash(PyTupleObject *v)
register Py_hash_t y;
register Py_ssize_t len = Py_SIZE(v);
register PyObject **p;
Py_uhash_t mult = 1000003;
Py_uhash_t mult = _PyHASH_MULTIPLIER;
x = 0x345678;
p = v->ob_item;
while (--len >= 0) {

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@ -11210,7 +11210,7 @@ unicode_hash(PyObject *self)
#define HASH(P) \
x = (Py_uhash_t)*P << 7; \
while (--len >= 0) \
x = (1000003*x) ^ (Py_uhash_t)*P++;
x = (_PyHASH_MULTIPLIER*x) ^ (Py_uhash_t)*P++;
switch (PyUnicode_KIND(self)) {
case PyUnicode_1BYTE_KIND: {