diff options
| -rw-r--r-- | Objects/floatobject.c | 95 | ||||
| -rw-r--r-- | Python/pystrtod.c | 14 |
2 files changed, 27 insertions, 82 deletions
diff --git a/Objects/floatobject.c b/Objects/floatobject.c index a433697..58f27e6 100644 --- a/Objects/floatobject.c +++ b/Objects/floatobject.c @@ -299,63 +299,6 @@ PyFloat_AsDouble(PyObject *op) /* Methods */ -static void -format_float(char *buf, size_t buflen, PyFloatObject *v, int precision) -{ - register char *cp; - int i; - - /* Subroutine for float_repr and float_print. - We want float numbers to be recognizable as such, - i.e., they should contain a decimal point or an exponent. - However, %g may print the number as an integer; - in such cases, we append ".0" to the string. */ - - assert(PyFloat_Check(v)); - _PyOS_double_to_string(buf, buflen, v->ob_fval, 'g', precision, - 0, NULL); - cp = buf; - if (*cp == '-') - cp++; - for (; *cp != '\0'; cp++) { - /* Any non-digit means it's not an integer; - this takes care of NAN and INF as well. */ - if (!isdigit(Py_CHARMASK(*cp))) - break; - } - if (*cp == '\0') { - *cp++ = '.'; - *cp++ = '0'; - *cp++ = '\0'; - return; - } - /* Checking the next three chars should be more than enough to - * detect inf or nan, even on Windows. We check for inf or nan - * at last because they are rare cases. - */ - for (i=0; *cp != '\0' && i<3; cp++, i++) { - if (isdigit(Py_CHARMASK(*cp)) || *cp == '.') - continue; - /* found something that is neither a digit nor point - * it might be a NaN or INF - */ -#ifdef Py_NAN - if (Py_IS_NAN(v->ob_fval)) { - strcpy(buf, "nan"); - } - else -#endif - if (Py_IS_INFINITY(v->ob_fval)) { - cp = buf; - if (*cp == '-') - cp++; - strcpy(cp, "inf"); - } - break; - } - -} - /* XXX PyFloat_AsStringEx should not be a public API function (for one XXX thing, its signature passes a buffer without a length; for another, XXX it isn't useful outside this file). @@ -363,7 +306,8 @@ format_float(char *buf, size_t buflen, PyFloatObject *v, int precision) void PyFloat_AsStringEx(char *buf, PyFloatObject *v, int precision) { - format_float(buf, 100, v, precision); + _PyOS_double_to_string(buf, 100, v->ob_fval, 'g', precision, + Py_DTSF_ADD_DOT_0, NULL); } /* Macro and helper that convert PyObject obj to a C double and store @@ -402,36 +346,21 @@ convert_to_double(PyObject **v, double *dbl) return 0; } -/* Precisions used by repr() and str(), respectively. - - The repr() precision (17 significant decimal digits) is the minimal number - that is guaranteed to have enough precision so that if the number is read - back in the exact same binary value is recreated. This is true for IEEE - floating point by design, and also happens to work for all other modern - hardware. - - The str() precision is chosen so that in most cases, the rounding noise - created by various operations is suppressed, while giving plenty of - precision for practical use. - -*/ - -#define PREC_REPR 17 -#define PREC_STR 12 - /* XXX PyFloat_AsString and PyFloat_AsReprString should be deprecated: XXX they pass a char buffer without passing a length. */ void PyFloat_AsString(char *buf, PyFloatObject *v) { - format_float(buf, 100, v, PREC_STR); + _PyOS_double_to_string(buf, 100, v->ob_fval, 's', 0, + Py_DTSF_ADD_DOT_0, NULL); } void PyFloat_AsReprString(char *buf, PyFloatObject *v) { - format_float(buf, 100, v, PREC_REPR); + _PyOS_double_to_string(buf, 100, v->ob_fval, 'r', 0, + Py_DTSF_ADD_DOT_0, NULL); } /* ARGSUSED */ @@ -439,8 +368,9 @@ static int float_print(PyFloatObject *v, FILE *fp, int flags) { char buf[100]; - format_float(buf, sizeof(buf), v, - (flags & Py_PRINT_RAW) ? PREC_STR : PREC_REPR); + _PyOS_double_to_string(buf, sizeof(buf), v->ob_fval, + (flags & Py_PRINT_RAW) ? 's' : 'r', + 0, Py_DTSF_ADD_DOT_0, NULL); Py_BEGIN_ALLOW_THREADS fputs(buf, fp); Py_END_ALLOW_THREADS @@ -451,8 +381,8 @@ static PyObject * float_repr(PyFloatObject *v) { char buf[100]; - format_float(buf, sizeof(buf), v, PREC_REPR); - + _PyOS_double_to_string(buf, sizeof(buf), v->ob_fval, 'r', 0, + Py_DTSF_ADD_DOT_0, NULL); return PyString_FromString(buf); } @@ -460,7 +390,8 @@ static PyObject * float_str(PyFloatObject *v) { char buf[100]; - format_float(buf, sizeof(buf), v, PREC_STR); + _PyOS_double_to_string(buf, sizeof(buf), v->ob_fval, 's', 0, + Py_DTSF_ADD_DOT_0, NULL); return PyString_FromString(buf); } diff --git a/Python/pystrtod.c b/Python/pystrtod.c index 2df4e3d..30dd4e5 100644 --- a/Python/pystrtod.c +++ b/Python/pystrtod.c @@ -595,6 +595,20 @@ PyOS_ascii_formatd(char *buffer, return buffer; } +/* Precisions used by repr() and str(), respectively. + + The repr() precision (17 significant decimal digits) is the minimal number + that is guaranteed to have enough precision so that if the number is read + back in the exact same binary value is recreated. This is true for IEEE + floating point by design, and also happens to work for all other modern + hardware. + + The str() precision (12 significant decimal digits) is chosen so that in + most cases, the rounding noise created by various operations is suppressed, + while giving plenty of precision for practical use. + +*/ + PyAPI_FUNC(void) _PyOS_double_to_string(char *buf, size_t buf_len, double val, char format_code, int precision, |