floatobject.c

python s60 1.4.5版本的源代码

	PyFPE_START_PROTECT("divide", return 0)
	a = a / b;
	PyFPE_END_PROTECT(a)
	return PyFloat_FromDouble(a);
}

static PyObject *
float_rem(PyObject *v, PyObject *w)
{
	double vx, wx;
	double mod;
 	CONVERT_TO_DOUBLE(v, vx);
 	CONVERT_TO_DOUBLE(w, wx);
	if (wx == 0.0) {
		PyErr_SetString(PyExc_ZeroDivisionError, "float modulo");
		return NULL;
	}
	PyFPE_START_PROTECT("modulo", return 0)
	mod = fmod(vx, wx);
	/* note: checking mod*wx < 0 is incorrect -- underflows to
	   0 if wx < sqrt(smallest nonzero double) */
	if (mod && ((wx < 0) != (mod < 0))) {
		mod += wx;
	}
	PyFPE_END_PROTECT(mod)
	return PyFloat_FromDouble(mod);
}

static PyObject *
float_divmod(PyObject *v, PyObject *w)
{
	double vx, wx;
	double div, mod, floordiv;
 	CONVERT_TO_DOUBLE(v, vx);
 	CONVERT_TO_DOUBLE(w, wx);
	if (wx == 0.0) {
		PyErr_SetString(PyExc_ZeroDivisionError, "float divmod()");
		return NULL;
	}
	PyFPE_START_PROTECT("divmod", return 0)
	mod = fmod(vx, wx);
	/* fmod is typically exact, so vx-mod is *mathematically* an
	   exact multiple of wx.  But this is fp arithmetic, and fp
	   vx - mod is an approximation; the result is that div may
	   not be an exact integral value after the division, although
	   it will always be very close to one.
	*/
	div = (vx - mod) / wx;
	if (mod) {
		/* ensure the remainder has the same sign as the denominator */
		if ((wx < 0) != (mod < 0)) {
			mod += wx;
			div -= 1.0;
		}
	}
	else {
		/* the remainder is zero, and in the presence of signed zeroes
		   fmod returns different results across platforms; ensure
		   it has the same sign as the denominator; we'd like to do
		   "mod = wx * 0.0", but that may get optimized away */
		mod *= mod;  /* hide "mod = +0" from optimizer */
		if (wx < 0.0)
			mod = -mod;
	}
	/* snap quotient to nearest integral value */
	if (div) {
		floordiv = floor(div);
		if (div - floordiv > 0.5)
			floordiv += 1.0;
	}
	else {
		/* div is zero - get the same sign as the true quotient */
		div *= div;	/* hide "div = +0" from optimizers */
		floordiv = div * vx / wx; /* zero w/ sign of vx/wx */
	}
	PyFPE_END_PROTECT(floordiv)
	return Py_BuildValue("(dd)", floordiv, mod);
}

static PyObject *
float_floor_div(PyObject *v, PyObject *w)
{
	PyObject *t, *r;

	t = float_divmod(v, w);
	if (t == NULL || t == Py_NotImplemented)
		return t;
	assert(PyTuple_CheckExact(t));
	r = PyTuple_GET_ITEM(t, 0);
	Py_INCREF(r);
	Py_DECREF(t);
	return r;
}

static PyObject *
float_pow(PyObject *v, PyObject *w, PyObject *z)
{
	double iv, iw, ix;

	if ((PyObject *)z != Py_None) {
		PyErr_SetString(PyExc_TypeError, "pow() 3rd argument not "
			"allowed unless all arguments are integers");
		return NULL;
	}

	CONVERT_TO_DOUBLE(v, iv);
	CONVERT_TO_DOUBLE(w, iw);

	/* Sort out special cases here instead of relying on pow() */
	if (iw == 0) { 		/* v**0 is 1, even 0**0 */
		PyFPE_START_PROTECT("pow", return NULL)
		if ((PyObject *)z != Py_None) {
			double iz;
			CONVERT_TO_DOUBLE(z, iz);
			ix = fmod(1.0, iz);
			if (ix != 0 && iz < 0)
				ix += iz;
		}
		else
			ix = 1.0;
		PyFPE_END_PROTECT(ix)
		return PyFloat_FromDouble(ix);
	}
	if (iv == 0.0) {  /* 0**w is error if w<0, else 1 */
		if (iw < 0.0) {
			PyErr_SetString(PyExc_ZeroDivisionError,
					"0.0 cannot be raised to a negative power");
			return NULL;
		}
		return PyFloat_FromDouble(0.0);
	}
	if (iv < 0.0 && iw != floor(iw)) {
		PyErr_SetString(PyExc_ValueError,
				"negative number cannot be raised to a fractional power");
		return NULL;
	}
	errno = 0;
	PyFPE_START_PROTECT("pow", return NULL)
	ix = pow(iv, iw);
	PyFPE_END_PROTECT(ix)
	Py_ADJUST_ERANGE1(ix);
	if (errno != 0) {
		assert(errno == ERANGE);
		PyErr_SetFromErrno(PyExc_OverflowError);
		return NULL;
	}
	return PyFloat_FromDouble(ix);
}

static PyObject *
float_neg(PyFloatObject *v)
{
	return PyFloat_FromDouble(-v->ob_fval);
}

static PyObject *
float_pos(PyFloatObject *v)
{
	if (PyFloat_CheckExact(v)) {
		Py_INCREF(v);
		return (PyObject *)v;
	}
	else
		return PyFloat_FromDouble(v->ob_fval);
}

static PyObject *
float_abs(PyFloatObject *v)
{
	return PyFloat_FromDouble(fabs(v->ob_fval));
}

static int
float_nonzero(PyFloatObject *v)
{
	return v->ob_fval != 0.0;
}

static int
float_coerce(PyObject **pv, PyObject **pw)
{
	if (PyInt_Check(*pw)) {
		long x = PyInt_AsLong(*pw);
		*pw = PyFloat_FromDouble((double)x);
		Py_INCREF(*pv);
		return 0;
	}
	else if (PyLong_Check(*pw)) {
		*pw = PyFloat_FromDouble(PyLong_AsDouble(*pw));
		Py_INCREF(*pv);
		return 0;
	}
	else if (PyFloat_Check(*pw)) {
		Py_INCREF(*pv);
		Py_INCREF(*pw);
		return 0;
	}
	return 1; /* Can't do it */
}

static PyObject *
float_int(PyObject *v)
{
	double x = PyFloat_AsDouble(v);
	double wholepart;	/* integral portion of x, rounded toward 0 */
	long aslong;		/* (long)wholepart */

	(void)modf(x, &wholepart);
#ifdef RISCOS
	/* conversion from floating to integral type would raise exception */
	if (wholepart>LONG_MAX || wholepart<LONG_MIN) {
		PyErr_SetString(PyExc_OverflowError, "float too large to convert");
		return NULL;
	}
#endif
	/* doubles may have more bits than longs, or vice versa; and casting
	   to long may yield gibberish in either case.  What really matters
	   is whether converting back to double again reproduces what we
	   started with. */
	aslong = (long)wholepart;
	if ((double)aslong == wholepart)
		return PyInt_FromLong(aslong);
	PyErr_SetString(PyExc_OverflowError, "float too large to convert");
	return NULL;
}

static PyObject *
float_long(PyObject *v)
{
	double x = PyFloat_AsDouble(v);
	return PyLong_FromDouble(x);
}

static PyObject *
float_float(PyObject *v)
{
	Py_INCREF(v);
	return v;
}


staticforward PyObject *
float_subtype_new(PyTypeObject *type, PyObject *args, PyObject *kwds);

static PyObject *
float_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
	PyObject *x = Py_False; /* Integer zero */
	static const char *const kwlist[] = {"x", 0};

	if (type != &PyFloat_Type)
		return float_subtype_new(type, args, kwds); /* Wimp out */
	if (!PyArg_ParseTupleAndKeywords(args, kwds, "|O:float", kwlist, &x))
		return NULL;
	if (PyString_Check(x))
		return PyFloat_FromString(x, NULL);
	return PyNumber_Float(x);
}

/* Wimpy, slow approach to tp_new calls for subtypes of float:
   first create a regular float from whatever arguments we got,
   then allocate a subtype instance and initialize its ob_fval
   from the regular float.  The regular float is then thrown away.
*/
static PyObject *
float_subtype_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
	PyObject *tmp, *new;

	assert(PyType_IsSubtype(type, &PyFloat_Type));
	tmp = float_new(&PyFloat_Type, args, kwds);
	if (tmp == NULL)
		return NULL;
	assert(PyFloat_CheckExact(tmp));
	new = type->tp_alloc(type, 0);
	if (new == NULL)
		return NULL;
	((PyFloatObject *)new)->ob_fval = ((PyFloatObject *)tmp)->ob_fval;
	Py_DECREF(tmp);
	return new;
}

const static char float_doc[] =
#ifdef SYMBIAN
"";
#else
"float(x) -> floating point number\n\
\n\
Convert a string or number to a floating point number, if possible.";
#endif


const static PyNumberMethods float_as_number = {
	(binaryfunc)float_add, /*nb_add*/
	(binaryfunc)float_sub, /*nb_subtract*/
	(binaryfunc)float_mul, /*nb_multiply*/
	(binaryfunc)float_classic_div, /*nb_divide*/
	(binaryfunc)float_rem, /*nb_remainder*/
	(binaryfunc)float_divmod, /*nb_divmod*/
	(ternaryfunc)float_pow, /*nb_power*/
	(unaryfunc)float_neg, /*nb_negative*/
	(unaryfunc)float_pos, /*nb_positive*/
	(unaryfunc)float_abs, /*nb_absolute*/
	(inquiry)float_nonzero, /*nb_nonzero*/
	0,		/*nb_invert*/
	0,		/*nb_lshift*/
	0,		/*nb_rshift*/
	0,		/*nb_and*/
	0,		/*nb_xor*/
	0,		/*nb_or*/
	(coercion)float_coerce, /*nb_coerce*/
	(unaryfunc)float_int, /*nb_int*/
	(unaryfunc)float_long, /*nb_long*/
	(unaryfunc)float_float, /*nb_float*/
	0,		/* nb_oct */
	0,		/* nb_hex */
	0,		/* nb_inplace_add */
	0,		/* nb_inplace_subtract */
	0,		/* nb_inplace_multiply */
	0,		/* nb_inplace_divide */
	0,		/* nb_inplace_remainder */
	0, 		/* nb_inplace_power */
	0,		/* nb_inplace_lshift */
	0,		/* nb_inplace_rshift */
	0,		/* nb_inplace_and */
	0,		/* nb_inplace_xor */
	0,		/* nb_inplace_or */
	float_floor_div, /* nb_floor_divide */
	float_div,	/* nb_true_divide */
	0,		/* nb_inplace_floor_divide */
	0,		/* nb_inplace_true_divide */
};

#ifndef SYMBIAN
PyTypeObject PyFloat_Type = {
	PyObject_HEAD_INIT(&PyType_Type)
#else
const PyTypeObject c_PyFloat_Type = {
	PyObject_HEAD_INIT(NULL)
#endif
	0,
	"float",
	sizeof(PyFloatObject),
	0,
	(destructor)float_dealloc,		/* tp_dealloc */
	(printfunc)float_print, 		/* tp_print */
	0,					/* tp_getattr */
	0,					/* tp_setattr */
	(cmpfunc)float_compare, 		/* tp_compare */
	(reprfunc)float_repr,			/* tp_repr */
	&float_as_number,			/* tp_as_number */
	0,					/* tp_as_sequence */
	0,					/* tp_as_mapping */
	(hashfunc)float_hash,			/* tp_hash */
	0,					/* tp_call */
	(reprfunc)float_str,			/* tp_str */
	PyObject_GenericGetAttr,		/* tp_getattro */
	0,					/* tp_setattro */
	0,					/* tp_as_buffer */
	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_CHECKTYPES |
		Py_TPFLAGS_BASETYPE,		/* tp_flags */
	float_doc,				/* tp_doc */
 	0,					/* tp_traverse */
	0,					/* tp_clear */
	0,					/* tp_richcompare */
	0,					/* tp_weaklistoffset */
	0,					/* tp_iter */
	0,					/* tp_iternext */
	0,					/* tp_methods */
	0,					/* tp_members */
	0,					/* tp_getset */
	0,					/* tp_base */
	0,					/* tp_dict */
	0,					/* tp_descr_get */
	0,					/* tp_descr_set */
	0,					/* tp_dictoffset */
	0,					/* tp_init */
	0,					/* tp_alloc */
	float_new,				/* tp_new */
};

DL_EXPORT(void)
PyFloat_Fini(void)
{
	PyFloatObject *p;
	PyFloatBlock *list, *next;
	int i;
	int bc, bf;	/* block count, number of freed blocks */
	int frem, fsum;	/* remaining unfreed floats per block, total */

#ifdef SYMBIAN
	SPy_Python_globals* pyglobals = PYTHON_GLOBALS; // avoid TLS reads
#endif

	bc = 0;
	bf = 0;
	fsum = 0;
	list = block_list;
	block_list = NULL;
	free_list = NULL;
	while (list != NULL) {
		bc++;
		frem = 0;
		for (i = 0, p = &list->objects[0];
		     i < N_FLOATOBJECTS;
		     i++, p++) {
			if (PyFloat_CheckExact(p) && p->ob_refcnt != 0)
				frem++;
		}
		next = list->next;
		if (frem) {
			list->next = block_list;
			block_list = list;
			for (i = 0, p = &list->objects[0];
			     i < N_FLOATOBJECTS;
			     i++, p++) {
				if (!PyFloat_CheckExact(p) ||
				    p->ob_refcnt == 0) {
					p->ob_type = (struct _typeobject *)
						free_list;
					free_list = p;
				}
			}
		}
		else {
			PyMem_FREE(list); /* XXX PyObject_FREE ??? */
			bf++;
		}
		fsum += frem;
		list = next;
	}
	if (!Py_VerboseFlag)
		return;
	fprintf(stderr, "# cleanup floats");
	if (!fsum) {
		fprintf(stderr, "\n");
	}
	else {
		fprintf(stderr,
			": %d unfreed float%s in %d out of %d block%s\n",
			fsum, fsum == 1 ? "" : "s",
			bc - bf, bc, bc == 1 ? "" : "s");
	}
	if (Py_VerboseFlag > 1) {
		list = block_list;
		while (list != NULL) {
			for (i = 0, p = &list->objects[0];
			     i < N_FLOATOBJECTS;
			     i++, p++) {
				if (PyFloat_CheckExact(p) &&
				    p->ob_refcnt != 0) {
					char buf[100];
					PyFloat_AsString(buf, p);
					fprintf(stderr,
			     "#   <float at %p, refcnt=%d, val=%s>\n",
						p, p->ob_refcnt, buf);
				}
			}
			list = list->next;
		}
	}
}