From 0a2f849b791d13cf0dde97dce2e71a19e2d60465 Mon Sep 17 00:00:00 2001 From: Raymond Hettinger Date: Mon, 6 Jan 2003 22:42:41 +0000 Subject: [PATCH] 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. --- Objects/stringobject.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/Objects/stringobject.c b/Objects/stringobject.c index acfce8b104..1a4a7547de 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; } -- 2.40.0