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| author | Guido van Rossum <guido@python.org> | 2007-08-31 00:27:03 (GMT) |
|---|---|---|
| committer | Guido van Rossum <guido@python.org> | 2007-08-31 00:27:03 (GMT) |
| commit | 6deb1bf83f93fc4d0b2433b94a28293e0ae6bc90 (patch) | |
| tree | 8d4ba92470efad16df8d79344316ce320258e818 | |
| parent | 74e68c751f148d6d41dd74d004ff19f05e244859 (diff) | |
| download | cpython-6deb1bf83f93fc4d0b2433b94a28293e0ae6bc90.zip cpython-6deb1bf83f93fc4d0b2433b94a28293e0ae6bc90.tar.gz cpython-6deb1bf83f93fc4d0b2433b94a28293e0ae6bc90.tar.bz2 | |
Use pow() instead of repeated multiplication by 10 in round(x, n).
| -rw-r--r-- | Objects/floatobject.c | 20 |
1 files changed, 5 insertions, 15 deletions
diff --git a/Objects/floatobject.c b/Objects/floatobject.c index f74b19d..c060d8b 100644 --- a/Objects/floatobject.c +++ b/Objects/floatobject.c @@ -771,10 +771,9 @@ float_round(PyObject *v, PyObject *args) { #define UNDEF_NDIGITS (-0x7fffffff) /* Unlikely ndigits value */ double x; - double f; + double f = 1.0; double flr, cil; double rounded; - int i; int ndigits = UNDEF_NDIGITS; if (!PyArg_ParseTuple(args, "|i", &ndigits)) @@ -783,14 +782,8 @@ float_round(PyObject *v, PyObject *args) x = PyFloat_AsDouble(v); if (ndigits != UNDEF_NDIGITS) { - f = 1.0; - i = abs(ndigits); - while (--i >= 0) - f = f*10.0; - if (ndigits < 0) - x /= f; - else - x *= f; + f = pow(10.0, ndigits); + x *= f; } flr = floor(x); @@ -798,16 +791,13 @@ float_round(PyObject *v, PyObject *args) if (x-flr > 0.5) rounded = cil; - else if (x-flr == 0.5) + else if (x-flr == 0.5) rounded = fmod(flr, 2) == 0 ? flr : cil; else rounded = flr; if (ndigits != UNDEF_NDIGITS) { - if (ndigits < 0) - rounded *= f; - else - rounded /= f; + rounded /= f; return PyFloat_FromDouble(rounded); } |