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| author | Raymond Hettinger <python@rcn.com> | 2003-01-06 22:42:41 (GMT) |
|---|---|---|
| committer | Raymond Hettinger <python@rcn.com> | 2003-01-06 22:42:41 (GMT) |
| commit | 0a2f849b791d13cf0dde97dce2e71a19e2d60465 (patch) | |
| tree | d52434d1d5aab5dc4a919018edf12b432a20c0f2 /Objects | |
| parent | 2720b0dff80650a04f8ebb3cc7163ec6897e02dd (diff) | |
| download | cpython-0a2f849b791d13cf0dde97dce2e71a19e2d60465.zip cpython-0a2f849b791d13cf0dde97dce2e71a19e2d60465.tar.gz cpython-0a2f849b791d13cf0dde97dce2e71a19e2d60465.tar.bz2 | |
GvR's idea to use memset() for the most common special case of repeating
a single character. Shaves another 10% off the running time by avoiding
the lg2(N) loops and cache effects for the other cases.
Diffstat (limited to 'Objects')
| -rw-r--r-- | Objects/stringobject.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/Objects/stringobject.c b/Objects/stringobject.c index acfce8b..1a4a754 100644 --- a/Objects/stringobject.c +++ b/Objects/stringobject.c @@ -966,6 +966,11 @@ string_repeat(register PyStringObject *a, register int n) PyObject_INIT_VAR(op, &PyString_Type, size); op->ob_shash = -1; op->ob_sstate = SSTATE_NOT_INTERNED; + op->ob_sval[size] = '\0'; + if (a->ob_size == 1 && n > 0) { + memset(op->ob_sval, a->ob_sval[0] , n); + return (PyObject *) op; + } i = 0; if (i < size) { memcpy(op->ob_sval, a->ob_sval, (int) a->ob_size); @@ -976,7 +981,6 @@ string_repeat(register PyStringObject *a, register int n) memcpy(op->ob_sval+i, op->ob_sval, j); i += j; } - op->ob_sval[size] = '\0'; return (PyObject *) op; } |