intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 2601 insertions, 0 deletions

diff --git a/contrib/tools/python3/src/Objects/floatobject.c b/contrib/tools/python3/src/Objects/floatobject.c
new file mode 100644
index 0000000000..8538a051b1
--- /dev/null
+++ b/contrib/tools/python3/src/Objects/floatobject.c
@@ -0,0 +1,2601 @@
+/* Float object implementation */
+
+/* XXX There should be overflow checks here, but it's hard to check
+   for any kind of float exception without losing portability. */
+
+#include "Python.h"
+#include "pycore_dtoa.h"
+
+#include <ctype.h>
+#include <float.h>
+
+/*[clinic input]
+class float "PyObject *" "&PyFloat_Type"
+[clinic start generated code]*/
+/*[clinic end generated code: output=da39a3ee5e6b4b0d input=dd0003f68f144284]*/
+
+#include "clinic/floatobject.c.h"
+
+/* Special free list
+   free_list is a singly-linked list of available PyFloatObjects, linked
+   via abuse of their ob_type members.
+*/
+
+#ifndef PyFloat_MAXFREELIST
+#define PyFloat_MAXFREELIST    100
+#endif
+static int numfree = 0;
+static PyFloatObject *free_list = NULL;
+
+double
+PyFloat_GetMax(void)
+{
+    return DBL_MAX;
+}
+
+double
+PyFloat_GetMin(void)
+{
+    return DBL_MIN;
+}
+
+static PyTypeObject FloatInfoType;
+
+PyDoc_STRVAR(floatinfo__doc__,
+"sys.float_info\n\
+\n\
+A named tuple holding information about the float type. It contains low level\n\
+information about the precision and internal representation. Please study\n\
+your system's :file:`float.h` for more information.");
+
+static PyStructSequence_Field floatinfo_fields[] = {
+    {"max",             "DBL_MAX -- maximum representable finite float"},
+    {"max_exp",         "DBL_MAX_EXP -- maximum int e such that radix**(e-1) "
+                    "is representable"},
+    {"max_10_exp",      "DBL_MAX_10_EXP -- maximum int e such that 10**e "
+                    "is representable"},
+    {"min",             "DBL_MIN -- Minimum positive normalized float"},
+    {"min_exp",         "DBL_MIN_EXP -- minimum int e such that radix**(e-1) "
+                    "is a normalized float"},
+    {"min_10_exp",      "DBL_MIN_10_EXP -- minimum int e such that 10**e is "
+                    "a normalized"},
+    {"dig",             "DBL_DIG -- digits"},
+    {"mant_dig",        "DBL_MANT_DIG -- mantissa digits"},
+    {"epsilon",         "DBL_EPSILON -- Difference between 1 and the next "
+                    "representable float"},
+    {"radix",           "FLT_RADIX -- radix of exponent"},
+    {"rounds",          "FLT_ROUNDS -- rounding mode"},
+    {0}
+};
+
+static PyStructSequence_Desc floatinfo_desc = {
+    "sys.float_info",           /* name */
+    floatinfo__doc__,           /* doc */
+    floatinfo_fields,           /* fields */
+    11
+};
+
+PyObject *
+PyFloat_GetInfo(void)
+{
+    PyObject* floatinfo;
+    int pos = 0;
+
+    floatinfo = PyStructSequence_New(&FloatInfoType);
+    if (floatinfo == NULL) {
+        return NULL;
+    }
+
+#define SetIntFlag(flag) \
+    PyStructSequence_SET_ITEM(floatinfo, pos++, PyLong_FromLong(flag))
+#define SetDblFlag(flag) \
+    PyStructSequence_SET_ITEM(floatinfo, pos++, PyFloat_FromDouble(flag))
+
+    SetDblFlag(DBL_MAX);
+    SetIntFlag(DBL_MAX_EXP);
+    SetIntFlag(DBL_MAX_10_EXP);
+    SetDblFlag(DBL_MIN);
+    SetIntFlag(DBL_MIN_EXP);
+    SetIntFlag(DBL_MIN_10_EXP);
+    SetIntFlag(DBL_DIG);
+    SetIntFlag(DBL_MANT_DIG);
+    SetDblFlag(DBL_EPSILON);
+    SetIntFlag(FLT_RADIX);
+    SetIntFlag(FLT_ROUNDS);
+#undef SetIntFlag
+#undef SetDblFlag
+
+    if (PyErr_Occurred()) {
+        Py_CLEAR(floatinfo);
+        return NULL;
+    }
+    return floatinfo;
+}
+
+PyObject *
+PyFloat_FromDouble(double fval)
+{
+    PyFloatObject *op = free_list;
+    if (op != NULL) {
+        free_list = (PyFloatObject *) Py_TYPE(op);
+        numfree--;
+    } else {
+        op = (PyFloatObject*) PyObject_MALLOC(sizeof(PyFloatObject));
+        if (!op)
+            return PyErr_NoMemory();
+    }
+    /* Inline PyObject_New */
+    (void)PyObject_INIT(op, &PyFloat_Type);
+    op->ob_fval = fval;
+    return (PyObject *) op;
+}
+
+static PyObject *
+float_from_string_inner(const char *s, Py_ssize_t len, void *obj)
+{
+    double x;
+    const char *end;
+    const char *last = s + len;
+    /* strip space */
+    while (s < last && Py_ISSPACE(*s)) {
+        s++;
+    }
+
+    while (s < last - 1 && Py_ISSPACE(last[-1])) {
+        last--;
+    }
+
+    /* We don't care about overflow or underflow.  If the platform
+     * supports them, infinities and signed zeroes (on underflow) are
+     * fine. */
+    x = PyOS_string_to_double(s, (char **)&end, NULL);
+    if (end != last) {
+        PyErr_Format(PyExc_ValueError,
+                     "could not convert string to float: "
+                     "%R", obj);
+        return NULL;
+    }
+    else if (x == -1.0 && PyErr_Occurred()) {
+        return NULL;
+    }
+    else {
+        return PyFloat_FromDouble(x);
+    }
+}
+
+PyObject *
+PyFloat_FromString(PyObject *v)
+{
+    const char *s;
+    PyObject *s_buffer = NULL;
+    Py_ssize_t len;
+    Py_buffer view = {NULL, NULL};
+    PyObject *result = NULL;
+
+    if (PyUnicode_Check(v)) {
+        s_buffer = _PyUnicode_TransformDecimalAndSpaceToASCII(v);
+        if (s_buffer == NULL)
+            return NULL;
+        assert(PyUnicode_IS_ASCII(s_buffer));
+        /* Simply get a pointer to existing ASCII characters. */
+        s = PyUnicode_AsUTF8AndSize(s_buffer, &len);
+        assert(s != NULL);
+    }
+    else if (PyBytes_Check(v)) {
+        s = PyBytes_AS_STRING(v);
+        len = PyBytes_GET_SIZE(v);
+    }
+    else if (PyByteArray_Check(v)) {
+        s = PyByteArray_AS_STRING(v);
+        len = PyByteArray_GET_SIZE(v);
+    }
+    else if (PyObject_GetBuffer(v, &view, PyBUF_SIMPLE) == 0) {
+        s = (const char *)view.buf;
+        len = view.len;
+        /* Copy to NUL-terminated buffer. */
+        s_buffer = PyBytes_FromStringAndSize(s, len);
+        if (s_buffer == NULL) {
+            PyBuffer_Release(&view);
+            return NULL;
+        }
+        s = PyBytes_AS_STRING(s_buffer);
+    }
+    else {
+        PyErr_Format(PyExc_TypeError,
+            "float() argument must be a string or a number, not '%.200s'",
+            Py_TYPE(v)->tp_name);
+        return NULL;
+    }
+    result = _Py_string_to_number_with_underscores(s, len, "float", v, v,
+                                                   float_from_string_inner);
+    PyBuffer_Release(&view);
+    Py_XDECREF(s_buffer);
+    return result;
+}
+
+static void
+float_dealloc(PyFloatObject *op)
+{
+    if (PyFloat_CheckExact(op)) {
+        if (numfree >= PyFloat_MAXFREELIST)  {
+            PyObject_FREE(op);
+            return;
+        }
+        numfree++;
+        Py_SET_TYPE(op, (PyTypeObject *)free_list);
+        free_list = op;
+    }
+    else
+        Py_TYPE(op)->tp_free((PyObject *)op);
+}
+
+double
+PyFloat_AsDouble(PyObject *op)
+{
+    PyNumberMethods *nb;
+    PyObject *res;
+    double val;
+
+    if (op == NULL) {
+        PyErr_BadArgument();
+        return -1;
+    }
+
+    if (PyFloat_Check(op)) {
+        return PyFloat_AS_DOUBLE(op);
+    }
+
+    nb = Py_TYPE(op)->tp_as_number;
+    if (nb == NULL || nb->nb_float == NULL) {
+        if (nb && nb->nb_index) {
+            PyObject *res = PyNumber_Index(op);
+            if (!res) {
+                return -1;
+            }
+            double val = PyLong_AsDouble(res);
+            Py_DECREF(res);
+            return val;
+        }
+        PyErr_Format(PyExc_TypeError, "must be real number, not %.50s",
+                     Py_TYPE(op)->tp_name);
+        return -1;
+    }
+
+    res = (*nb->nb_float) (op);
+    if (res == NULL) {
+        return -1;
+    }
+    if (!PyFloat_CheckExact(res)) {
+        if (!PyFloat_Check(res)) {
+            PyErr_Format(PyExc_TypeError,
+                         "%.50s.__float__ returned non-float (type %.50s)",
+                         Py_TYPE(op)->tp_name, Py_TYPE(res)->tp_name);
+            Py_DECREF(res);
+            return -1;
+        }
+        if (PyErr_WarnFormat(PyExc_DeprecationWarning, 1,
+                "%.50s.__float__ returned non-float (type %.50s).  "
+                "The ability to return an instance of a strict subclass of float "
+                "is deprecated, and may be removed in a future version of Python.",
+                Py_TYPE(op)->tp_name, Py_TYPE(res)->tp_name)) {
+            Py_DECREF(res);
+            return -1;
+        }
+    }
+
+    val = PyFloat_AS_DOUBLE(res);
+    Py_DECREF(res);
+    return val;
+}
+
+/* Macro and helper that convert PyObject obj to a C double and store
+   the value in dbl.  If conversion to double raises an exception, obj is
+   set to NULL, and the function invoking this macro returns NULL.  If
+   obj is not of float or int type, Py_NotImplemented is incref'ed,
+   stored in obj, and returned from the function invoking this macro.
+*/
+#define CONVERT_TO_DOUBLE(obj, dbl)                     \
+    if (PyFloat_Check(obj))                             \
+        dbl = PyFloat_AS_DOUBLE(obj);                   \
+    else if (convert_to_double(&(obj), &(dbl)) < 0)     \
+        return obj;
+
+/* Methods */
+
+static int
+convert_to_double(PyObject **v, double *dbl)
+{
+    PyObject *obj = *v;
+
+    if (PyLong_Check(obj)) {
+        *dbl = PyLong_AsDouble(obj);
+        if (*dbl == -1.0 && PyErr_Occurred()) {
+            *v = NULL;
+            return -1;
+        }
+    }
+    else {
+        Py_INCREF(Py_NotImplemented);
+        *v = Py_NotImplemented;
+        return -1;
+    }
+    return 0;
+}
+
+static PyObject *
+float_repr(PyFloatObject *v)
+{
+    PyObject *result;
+    char *buf;
+
+    buf = PyOS_double_to_string(PyFloat_AS_DOUBLE(v),
+                                'r', 0,
+                                Py_DTSF_ADD_DOT_0,
+                                NULL);
+    if (!buf)
+        return PyErr_NoMemory();
+    result = _PyUnicode_FromASCII(buf, strlen(buf));
+    PyMem_Free(buf);
+    return result;
+}
+
+/* Comparison is pretty much a nightmare.  When comparing float to float,
+ * we do it as straightforwardly (and long-windedly) as conceivable, so
+ * that, e.g., Python x == y delivers the same result as the platform
+ * C x == y when x and/or y is a NaN.
+ * When mixing float with an integer type, there's no good *uniform* approach.
+ * Converting the double to an integer obviously doesn't work, since we
+ * may lose info from fractional bits.  Converting the integer to a double
+ * also has two failure modes:  (1) an int may trigger overflow (too
+ * large to fit in the dynamic range of a C double); (2) even a C long may have
+ * more bits than fit in a C double (e.g., on a 64-bit box long may have
+ * 63 bits of precision, but a C double probably has only 53), and then
+ * we can falsely claim equality when low-order integer bits are lost by
+ * coercion to double.  So this part is painful too.
+ */
+
+static PyObject*
+float_richcompare(PyObject *v, PyObject *w, int op)
+{
+    double i, j;
+    int r = 0;
+
+    assert(PyFloat_Check(v));
+    i = PyFloat_AS_DOUBLE(v);
+
+    /* Switch on the type of w.  Set i and j to doubles to be compared,
+     * and op to the richcomp to use.
+     */
+    if (PyFloat_Check(w))
+        j = PyFloat_AS_DOUBLE(w);
+
+    else if (!Py_IS_FINITE(i)) {
+        if (PyLong_Check(w))
+            /* If i is an infinity, its magnitude exceeds any
+             * finite integer, so it doesn't matter which int we
+             * compare i with.  If i is a NaN, similarly.
+             */
+            j = 0.0;
+        else
+            goto Unimplemented;
+    }
+
+    else if (PyLong_Check(w)) {
+        int vsign = i == 0.0 ? 0 : i < 0.0 ? -1 : 1;
+        int wsign = _PyLong_Sign(w);
+        size_t nbits;
+        int exponent;
+
+        if (vsign != wsign) {
+            /* Magnitudes are irrelevant -- the signs alone
+             * determine the outcome.
+             */
+            i = (double)vsign;
+            j = (double)wsign;
+            goto Compare;
+        }
+        /* The signs are the same. */
+        /* Convert w to a double if it fits.  In particular, 0 fits. */
+        nbits = _PyLong_NumBits(w);
+        if (nbits == (size_t)-1 && PyErr_Occurred()) {
+            /* This long is so large that size_t isn't big enough
+             * to hold the # of bits.  Replace with little doubles
+             * that give the same outcome -- w is so large that
+             * its magnitude must exceed the magnitude of any
+             * finite float.
+             */
+            PyErr_Clear();
+            i = (double)vsign;
+            assert(wsign != 0);
+            j = wsign * 2.0;
+            goto Compare;
+        }
+        if (nbits <= 48) {
+            j = PyLong_AsDouble(w);
+            /* It's impossible that <= 48 bits overflowed. */
+            assert(j != -1.0 || ! PyErr_Occurred());
+            goto Compare;
+        }
+        assert(wsign != 0); /* else nbits was 0 */
+        assert(vsign != 0); /* if vsign were 0, then since wsign is
+                             * not 0, we would have taken the
+                             * vsign != wsign branch at the start */
+        /* We want to work with non-negative numbers. */
+        if (vsign < 0) {
+            /* "Multiply both sides" by -1; this also swaps the
+             * comparator.
+             */
+            i = -i;
+            op = _Py_SwappedOp[op];
+        }
+        assert(i > 0.0);
+        (void) frexp(i, &exponent);
+        /* exponent is the # of bits in v before the radix point;
+         * we know that nbits (the # of bits in w) > 48 at this point
+         */
+        if (exponent < 0 || (size_t)exponent < nbits) {
+            i = 1.0;
+            j = 2.0;
+            goto Compare;
+        }
+        if ((size_t)exponent > nbits) {
+            i = 2.0;
+            j = 1.0;
+            goto Compare;
+        }
+        /* v and w have the same number of bits before the radix
+         * point.  Construct two ints that have the same comparison
+         * outcome.
+         */
+        {
+            double fracpart;
+            double intpart;
+            PyObject *result = NULL;
+            PyObject *vv = NULL;
+            PyObject *ww = w;
+
+            if (wsign < 0) {
+                ww = PyNumber_Negative(w);
+                if (ww == NULL)
+                    goto Error;
+            }
+            else
+                Py_INCREF(ww);
+
+            fracpart = modf(i, &intpart);
+            vv = PyLong_FromDouble(intpart);
+            if (vv == NULL)
+                goto Error;
+
+            if (fracpart != 0.0) {
+                /* Shift left, and or a 1 bit into vv
+                 * to represent the lost fraction.
+                 */
+                PyObject *temp;
+
+                temp = _PyLong_Lshift(ww, 1);
+                if (temp == NULL)
+                    goto Error;
+                Py_DECREF(ww);
+                ww = temp;
+
+                temp = _PyLong_Lshift(vv, 1);
+                if (temp == NULL)
+                    goto Error;
+                Py_DECREF(vv);
+                vv = temp;
+
+                temp = PyNumber_Or(vv, _PyLong_One);
+                if (temp == NULL)
+                    goto Error;
+                Py_DECREF(vv);
+                vv = temp;
+            }
+
+            r = PyObject_RichCompareBool(vv, ww, op);
+            if (r < 0)
+                goto Error;
+            result = PyBool_FromLong(r);
+         Error:
+            Py_XDECREF(vv);
+            Py_XDECREF(ww);
+            return result;
+        }
+    } /* else if (PyLong_Check(w)) */
+
+    else        /* w isn't float or int */
+        goto Unimplemented;
+
+ Compare:
+    switch (op) {
+    case Py_EQ:
+        r = i == j;
+        break;
+    case Py_NE:
+        r = i != j;
+        break;
+    case Py_LE:
+        r = i <= j;
+        break;
+    case Py_GE:
+        r = i >= j;
+        break;
+    case Py_LT:
+        r = i < j;
+        break;
+    case Py_GT:
+        r = i > j;
+        break;
+    }
+    return PyBool_FromLong(r);
+
+ Unimplemented:
+    Py_RETURN_NOTIMPLEMENTED;
+}
+
+static Py_hash_t
+float_hash(PyFloatObject *v)
+{
+    return _Py_HashDouble(v->ob_fval);
+}
+
+static PyObject *
+float_add(PyObject *v, PyObject *w)
+{
+    double a,b;
+    CONVERT_TO_DOUBLE(v, a);
+    CONVERT_TO_DOUBLE(w, b);
+    a = a + b;
+    return PyFloat_FromDouble(a);
+}
+
+static PyObject *
+float_sub(PyObject *v, PyObject *w)
+{
+    double a,b;
+    CONVERT_TO_DOUBLE(v, a);
+    CONVERT_TO_DOUBLE(w, b);
+    a = a - b;
+    return PyFloat_FromDouble(a);
+}
+
+static PyObject *
+float_mul(PyObject *v, PyObject *w)
+{
+    double a,b;
+    CONVERT_TO_DOUBLE(v, a);
+    CONVERT_TO_DOUBLE(w, b);
+    a = a * b;
+    return PyFloat_FromDouble(a);
+}
+
+static PyObject *
+float_div(PyObject *v, PyObject *w)
+{
+    double a,b;
+    CONVERT_TO_DOUBLE(v, a);
+    CONVERT_TO_DOUBLE(w, b);
+    if (b == 0.0) {
+        PyErr_SetString(PyExc_ZeroDivisionError,
+                        "float division by zero");
+        return NULL;
+    }
+    a = a / b;
+    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;
+    }
+    mod = fmod(vx, wx);
+    if (mod) {
+        /* ensure the remainder has the same sign as the denominator */
+        if ((wx < 0) != (mod < 0)) {
+            mod += wx;
+        }
+    }
+    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. */
+        mod = copysign(0.0, wx);
+    }
+    return PyFloat_FromDouble(mod);
+}
+
+static void
+_float_div_mod(double vx, double wx, double *floordiv, double *mod)
+{
+    double div;
+    *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. */
+        *mod = copysign(0.0, wx);
+    }
+    /* 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 */
+        *floordiv = copysign(0.0, vx / wx); /* zero w/ sign of vx/wx */
+    }
+}
+
+static PyObject *
+float_divmod(PyObject *v, PyObject *w)
+{
+    double vx, wx;
+    double mod, floordiv;
+    CONVERT_TO_DOUBLE(v, vx);
+    CONVERT_TO_DOUBLE(w, wx);
+    if (wx == 0.0) {
+        PyErr_SetString(PyExc_ZeroDivisionError, "float divmod()");
+        return NULL;
+    }
+    _float_div_mod(vx, wx, &floordiv, &mod);
+    return Py_BuildValue("(dd)", floordiv, mod);
+}
+
+static PyObject *
+float_floor_div(PyObject *v, PyObject *w)
+{
+    double vx, wx;
+    double mod, floordiv;
+    CONVERT_TO_DOUBLE(v, vx);
+    CONVERT_TO_DOUBLE(w, wx);
+    if (wx == 0.0) {
+        PyErr_SetString(PyExc_ZeroDivisionError, "float floor division by zero");
+        return NULL;
+    }
+    _float_div_mod(vx, wx, &floordiv, &mod);
+    return PyFloat_FromDouble(floordiv);
+}
+
+/* determine whether x is an odd integer or not;  assumes that
+   x is not an infinity or nan. */
+#define DOUBLE_IS_ODD_INTEGER(x) (fmod(fabs(x), 2.0) == 1.0)
+
+static PyObject *
+float_pow(PyObject *v, PyObject *w, PyObject *z)
+{
+    double iv, iw, ix;
+    int negate_result = 0;
+
+    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 */
+        return PyFloat_FromDouble(1.0);
+    }
+    if (Py_IS_NAN(iv)) {        /* nan**w = nan, unless w == 0 */
+        return PyFloat_FromDouble(iv);
+    }
+    if (Py_IS_NAN(iw)) {        /* v**nan = nan, unless v == 1; 1**nan = 1 */
+        return PyFloat_FromDouble(iv == 1.0 ? 1.0 : iw);
+    }
+    if (Py_IS_INFINITY(iw)) {
+        /* v**inf is: 0.0 if abs(v) < 1; 1.0 if abs(v) == 1; inf if
+         *     abs(v) > 1 (including case where v infinite)
+         *
+         * v**-inf is: inf if abs(v) < 1; 1.0 if abs(v) == 1; 0.0 if
+         *     abs(v) > 1 (including case where v infinite)
+         */
+        iv = fabs(iv);
+        if (iv == 1.0)
+            return PyFloat_FromDouble(1.0);
+        else if ((iw > 0.0) == (iv > 1.0))
+            return PyFloat_FromDouble(fabs(iw)); /* return inf */
+        else
+            return PyFloat_FromDouble(0.0);
+    }
+    if (Py_IS_INFINITY(iv)) {
+        /* (+-inf)**w is: inf for w positive, 0 for w negative; in
+         *     both cases, we need to add the appropriate sign if w is
+         *     an odd integer.
+         */
+        int iw_is_odd = DOUBLE_IS_ODD_INTEGER(iw);
+        if (iw > 0.0)
+            return PyFloat_FromDouble(iw_is_odd ? iv : fabs(iv));
+        else
+            return PyFloat_FromDouble(iw_is_odd ?
+                                      copysign(0.0, iv) : 0.0);
+    }
+    if (iv == 0.0) {  /* 0**w is: 0 for w positive, 1 for w zero
+                         (already dealt with above), and an error
+                         if w is negative. */
+        int iw_is_odd = DOUBLE_IS_ODD_INTEGER(iw);
+        if (iw < 0.0) {
+            PyErr_SetString(PyExc_ZeroDivisionError,
+                            "0.0 cannot be raised to a "
+                            "negative power");
+            return NULL;
+        }
+        /* use correct sign if iw is odd */
+        return PyFloat_FromDouble(iw_is_odd ? iv : 0.0);
+    }
+
+    if (iv < 0.0) {
+        /* Whether this is an error is a mess, and bumps into libm
+         * bugs so we have to figure it out ourselves.
+         */
+        if (iw != floor(iw)) {
+            /* Negative numbers raised to fractional powers
+             * become complex.
+             */
+            return PyComplex_Type.tp_as_number->nb_power(v, w, z);
+        }
+        /* iw is an exact integer, albeit perhaps a very large
+         * one.  Replace iv by its absolute value and remember
+         * to negate the pow result if iw is odd.
+         */
+        iv = -iv;
+        negate_result = DOUBLE_IS_ODD_INTEGER(iw);
+    }
+
+    if (iv == 1.0) { /* 1**w is 1, even 1**inf and 1**nan */
+        /* (-1) ** large_integer also ends up here.  Here's an
+         * extract from the comments for the previous
+         * implementation explaining why this special case is
+         * necessary:
+         *
+         * -1 raised to an exact integer should never be exceptional.
+         * Alas, some libms (chiefly glibc as of early 2003) return
+         * NaN and set EDOM on pow(-1, large_int) if the int doesn't
+         * happen to be representable in a *C* integer.  That's a
+         * bug.
+         */
+        return PyFloat_FromDouble(negate_result ? -1.0 : 1.0);
+    }
+
+    /* Now iv and iw are finite, iw is nonzero, and iv is
+     * positive and not equal to 1.0.  We finally allow
+     * the platform pow to step in and do the rest.
+     */
+    errno = 0;
+    ix = pow(iv, iw);
+    Py_ADJUST_ERANGE1(ix);
+    if (negate_result)
+        ix = -ix;
+
+    if (errno != 0) {
+        /* We don't expect any errno value other than ERANGE, but
+         * the range of libm bugs appears unbounded.
+         */
+        PyErr_SetFromErrno(errno == ERANGE ? PyExc_OverflowError :
+                             PyExc_ValueError);
+        return NULL;
+    }
+    return PyFloat_FromDouble(ix);
+}
+
+#undef DOUBLE_IS_ODD_INTEGER
+
+static PyObject *
+float_neg(PyFloatObject *v)
+{
+    return PyFloat_FromDouble(-v->ob_fval);
+}
+
+static PyObject *
+float_abs(PyFloatObject *v)
+{
+    return PyFloat_FromDouble(fabs(v->ob_fval));
+}
+
+static int
+float_bool(PyFloatObject *v)
+{
+    return v->ob_fval != 0.0;
+}
+
+/*[clinic input]
+float.is_integer
+
+Return True if the float is an integer.
+[clinic start generated code]*/
+
+static PyObject *
+float_is_integer_impl(PyObject *self)
+/*[clinic end generated code: output=7112acf95a4d31ea input=311810d3f777e10d]*/
+{
+    double x = PyFloat_AsDouble(self);
+    PyObject *o;
+
+    if (x == -1.0 && PyErr_Occurred())
+        return NULL;
+    if (!Py_IS_FINITE(x))
+        Py_RETURN_FALSE;
+    errno = 0;
+    o = (floor(x) == x) ? Py_True : Py_False;
+    if (errno != 0) {
+        PyErr_SetFromErrno(errno == ERANGE ? PyExc_OverflowError :
+                             PyExc_ValueError);
+        return NULL;
+    }
+    Py_INCREF(o);
+    return o;
+}
+
+/*[clinic input]
+float.__trunc__
+
+Return the Integral closest to x between 0 and x.
+[clinic start generated code]*/
+
+static PyObject *
+float___trunc___impl(PyObject *self)
+/*[clinic end generated code: output=dd3e289dd4c6b538 input=591b9ba0d650fdff]*/
+{
+    return PyLong_FromDouble(PyFloat_AS_DOUBLE(self));
+}
+
+/*[clinic input]
+float.__floor__
+
+Return the floor as an Integral.
+[clinic start generated code]*/
+
+static PyObject *
+float___floor___impl(PyObject *self)
+/*[clinic end generated code: output=e0551dbaea8c01d1 input=77bb13eb12e268df]*/
+{
+    double x = PyFloat_AS_DOUBLE(self);
+    return PyLong_FromDouble(floor(x));
+}
+
+/*[clinic input]
+float.__ceil__
+
+Return the ceiling as an Integral.
+[clinic start generated code]*/
+
+static PyObject *
+float___ceil___impl(PyObject *self)
+/*[clinic end generated code: output=a2fd8858f73736f9 input=79e41ae94aa0a516]*/
+{
+    double x = PyFloat_AS_DOUBLE(self);
+    return PyLong_FromDouble(ceil(x));
+}
+
+/* double_round: rounds a finite double to the closest multiple of
+   10**-ndigits; here ndigits is within reasonable bounds (typically, -308 <=
+   ndigits <= 323).  Returns a Python float, or sets a Python error and
+   returns NULL on failure (OverflowError and memory errors are possible). */
+
+#ifndef PY_NO_SHORT_FLOAT_REPR
+/* version of double_round that uses the correctly-rounded string<->double
+   conversions from Python/dtoa.c */
+
+static PyObject *
+double_round(double x, int ndigits) {
+
+    double rounded;
+    Py_ssize_t buflen, mybuflen=100;
+    char *buf, *buf_end, shortbuf[100], *mybuf=shortbuf;
+    int decpt, sign;
+    PyObject *result = NULL;
+    _Py_SET_53BIT_PRECISION_HEADER;
+
+    /* round to a decimal string */
+    _Py_SET_53BIT_PRECISION_START;
+    buf = _Py_dg_dtoa(x, 3, ndigits, &decpt, &sign, &buf_end);
+    _Py_SET_53BIT_PRECISION_END;
+    if (buf == NULL) {
+        PyErr_NoMemory();
+        return NULL;
+    }
+
+    /* Get new buffer if shortbuf is too small.  Space needed <= buf_end -
+    buf + 8: (1 extra for '0', 1 for sign, 5 for exp, 1 for '\0').  */
+    buflen = buf_end - buf;
+    if (buflen + 8 > mybuflen) {
+        mybuflen = buflen+8;
+        mybuf = (char *)PyMem_Malloc(mybuflen);
+        if (mybuf == NULL) {
+            PyErr_NoMemory();
+            goto exit;
+        }
+    }
+    /* copy buf to mybuf, adding exponent, sign and leading 0 */
+    PyOS_snprintf(mybuf, mybuflen, "%s0%se%d", (sign ? "-" : ""),
+                  buf, decpt - (int)buflen);
+
+    /* and convert the resulting string back to a double */
+    errno = 0;
+    _Py_SET_53BIT_PRECISION_START;
+    rounded = _Py_dg_strtod(mybuf, NULL);
+    _Py_SET_53BIT_PRECISION_END;
+    if (errno == ERANGE && fabs(rounded) >= 1.)
+        PyErr_SetString(PyExc_OverflowError,
+                        "rounded value too large to represent");
+    else
+        result = PyFloat_FromDouble(rounded);
+
+    /* done computing value;  now clean up */
+    if (mybuf != shortbuf)
+        PyMem_Free(mybuf);
+  exit:
+    _Py_dg_freedtoa(buf);
+    return result;
+}
+
+#else /* PY_NO_SHORT_FLOAT_REPR */
+
+/* fallback version, to be used when correctly rounded binary<->decimal
+   conversions aren't available */
+
+static PyObject *
+double_round(double x, int ndigits) {
+    double pow1, pow2, y, z;
+    if (ndigits >= 0) {
+        if (ndigits > 22) {
+            /* pow1 and pow2 are each safe from overflow, but
+               pow1*pow2 ~= pow(10.0, ndigits) might overflow */
+            pow1 = pow(10.0, (double)(ndigits-22));
+            pow2 = 1e22;
+        }
+        else {
+            pow1 = pow(10.0, (double)ndigits);
+            pow2 = 1.0;
+        }
+        y = (x*pow1)*pow2;
+        /* if y overflows, then rounded value is exactly x */
+        if (!Py_IS_FINITE(y))
+            return PyFloat_FromDouble(x);
+    }
+    else {
+        pow1 = pow(10.0, (double)-ndigits);
+        pow2 = 1.0; /* unused; silences a gcc compiler warning */
+        y = x / pow1;
+    }
+
+    z = round(y);
+    if (fabs(y-z) == 0.5)
+        /* halfway between two integers; use round-half-even */
+        z = 2.0*round(y/2.0);
+
+    if (ndigits >= 0)
+        z = (z / pow2) / pow1;
+    else
+        z *= pow1;
+
+    /* if computation resulted in overflow, raise OverflowError */
+    if (!Py_IS_FINITE(z)) {
+        PyErr_SetString(PyExc_OverflowError,
+                        "overflow occurred during round");
+        return NULL;
+    }
+
+    return PyFloat_FromDouble(z);
+}
+
+#endif /* PY_NO_SHORT_FLOAT_REPR */
+
+/* round a Python float v to the closest multiple of 10**-ndigits */
+
+/*[clinic input]
+float.__round__
+
+    ndigits as o_ndigits: object = None
+    /
+
+Return the Integral closest to x, rounding half toward even.
+
+When an argument is passed, work like built-in round(x, ndigits).
+[clinic start generated code]*/
+
+static PyObject *
+float___round___impl(PyObject *self, PyObject *o_ndigits)
+/*[clinic end generated code: output=374c36aaa0f13980 input=fc0fe25924fbc9ed]*/
+{
+    double x, rounded;
+    Py_ssize_t ndigits;
+
+    x = PyFloat_AsDouble(self);
+    if (o_ndigits == Py_None) {
+        /* single-argument round or with None ndigits:
+         * round to nearest integer */
+        rounded = round(x);
+        if (fabs(x-rounded) == 0.5)
+            /* halfway case: round to even */
+            rounded = 2.0*round(x/2.0);
+        return PyLong_FromDouble(rounded);
+    }
+
+    /* interpret second argument as a Py_ssize_t; clips on overflow */
+    ndigits = PyNumber_AsSsize_t(o_ndigits, NULL);
+    if (ndigits == -1 && PyErr_Occurred())
+        return NULL;
+
+    /* nans and infinities round to themselves */
+    if (!Py_IS_FINITE(x))
+        return PyFloat_FromDouble(x);
+
+    /* Deal with extreme values for ndigits. For ndigits > NDIGITS_MAX, x
+       always rounds to itself.  For ndigits < NDIGITS_MIN, x always
+       rounds to +-0.0.  Here 0.30103 is an upper bound for log10(2). */
+#define NDIGITS_MAX ((int)((DBL_MANT_DIG-DBL_MIN_EXP) * 0.30103))
+#define NDIGITS_MIN (-(int)((DBL_MAX_EXP + 1) * 0.30103))
+    if (ndigits > NDIGITS_MAX)
+        /* return x */
+        return PyFloat_FromDouble(x);
+    else if (ndigits < NDIGITS_MIN)
+        /* return 0.0, but with sign of x */
+        return PyFloat_FromDouble(0.0*x);
+    else
+        /* finite x, and ndigits is not unreasonably large */
+        return double_round(x, (int)ndigits);
+#undef NDIGITS_MAX
+#undef NDIGITS_MIN
+}
+
+static PyObject *
+float_float(PyObject *v)
+{
+    if (PyFloat_CheckExact(v))
+        Py_INCREF(v);
+    else
+        v = PyFloat_FromDouble(((PyFloatObject *)v)->ob_fval);
+    return v;
+}
+
+/*[clinic input]
+float.conjugate
+
+Return self, the complex conjugate of any float.
+[clinic start generated code]*/
+
+static PyObject *
+float_conjugate_impl(PyObject *self)
+/*[clinic end generated code: output=8ca292c2479194af input=82ba6f37a9ff91dd]*/
+{
+    return float_float(self);
+}
+
+/* turn ASCII hex characters into integer values and vice versa */
+
+static char
+char_from_hex(int x)
+{
+    assert(0 <= x && x < 16);
+    return Py_hexdigits[x];
+}
+
+static int
+hex_from_char(char c) {
+    int x;
+    switch(c) {
+    case '0':
+        x = 0;
+        break;
+    case '1':
+        x = 1;
+        break;
+    case '2':
+        x = 2;
+        break;
+    case '3':
+        x = 3;
+        break;
+    case '4':
+        x = 4;
+        break;
+    case '5':
+        x = 5;
+        break;
+    case '6':
+        x = 6;
+        break;
+    case '7':
+        x = 7;
+        break;
+    case '8':
+        x = 8;
+        break;
+    case '9':
+        x = 9;
+        break;
+    case 'a':
+    case 'A':
+        x = 10;
+        break;
+    case 'b':
+    case 'B':
+        x = 11;
+        break;
+    case 'c':
+    case 'C':
+        x = 12;
+        break;
+    case 'd':
+    case 'D':
+        x = 13;
+        break;
+    case 'e':
+    case 'E':
+        x = 14;
+        break;
+    case 'f':
+    case 'F':
+        x = 15;
+        break;
+    default:
+        x = -1;
+        break;
+    }
+    return x;
+}
+
+/* convert a float to a hexadecimal string */
+
+/* TOHEX_NBITS is DBL_MANT_DIG rounded up to the next integer
+   of the form 4k+1. */
+#define TOHEX_NBITS DBL_MANT_DIG + 3 - (DBL_MANT_DIG+2)%4
+
+/*[clinic input]
+float.hex
+
+Return a hexadecimal representation of a floating-point number.
+
+>>> (-0.1).hex()
+'-0x1.999999999999ap-4'
+>>> 3.14159.hex()
+'0x1.921f9f01b866ep+1'
+[clinic start generated code]*/
+
+static PyObject *
+float_hex_impl(PyObject *self)
+/*[clinic end generated code: output=0ebc9836e4d302d4 input=bec1271a33d47e67]*/
+{
+    double x, m;
+    int e, shift, i, si, esign;
+    /* Space for 1+(TOHEX_NBITS-1)/4 digits, a decimal point, and the
+       trailing NUL byte. */
+    char s[(TOHEX_NBITS-1)/4+3];
+
+    CONVERT_TO_DOUBLE(self, x);
+
+    if (Py_IS_NAN(x) || Py_IS_INFINITY(x))
+        return float_repr((PyFloatObject *)self);
+
+    if (x == 0.0) {
+        if (copysign(1.0, x) == -1.0)
+            return PyUnicode_FromString("-0x0.0p+0");
+        else
+            return PyUnicode_FromString("0x0.0p+0");
+    }
+
+    m = frexp(fabs(x), &e);
+    shift = 1 - Py_MAX(DBL_MIN_EXP - e, 0);
+    m = ldexp(m, shift);
+    e -= shift;
+
+    si = 0;
+    s[si] = char_from_hex((int)m);
+    si++;
+    m -= (int)m;
+    s[si] = '.';
+    si++;
+    for (i=0; i < (TOHEX_NBITS-1)/4; i++) {
+        m *= 16.0;
+        s[si] = char_from_hex((int)m);
+        si++;
+        m -= (int)m;
+    }
+    s[si] = '\0';
+
+    if (e < 0) {
+        esign = (int)'-';
+        e = -e;
+    }
+    else
+        esign = (int)'+';
+
+    if (x < 0.0)
+        return PyUnicode_FromFormat("-0x%sp%c%d", s, esign, e);
+    else
+        return PyUnicode_FromFormat("0x%sp%c%d", s, esign, e);
+}
+
+/* Convert a hexadecimal string to a float. */
+
+/*[clinic input]
+@classmethod
+float.fromhex
+
+    string: object
+    /
+
+Create a floating-point number from a hexadecimal string.
+
+>>> float.fromhex('0x1.ffffp10')
+2047.984375
+>>> float.fromhex('-0x1p-1074')
+-5e-324
+[clinic start generated code]*/
+
+static PyObject *
+float_fromhex(PyTypeObject *type, PyObject *string)
+/*[clinic end generated code: output=46c0274d22b78e82 input=0407bebd354bca89]*/
+{
+    PyObject *result;
+    double x;
+    long exp, top_exp, lsb, key_digit;
+    const char *s, *coeff_start, *s_store, *coeff_end, *exp_start, *s_end;
+    int half_eps, digit, round_up, negate=0;
+    Py_ssize_t length, ndigits, fdigits, i;
+
+    /*
+     * For the sake of simplicity and correctness, we impose an artificial
+     * limit on ndigits, the total number of hex digits in the coefficient
+     * The limit is chosen to ensure that, writing exp for the exponent,
+     *
+     *   (1) if exp > LONG_MAX/2 then the value of the hex string is
+     *   guaranteed to overflow (provided it's nonzero)
+     *
+     *   (2) if exp < LONG_MIN/2 then the value of the hex string is
+     *   guaranteed to underflow to 0.
+     *
+     *   (3) if LONG_MIN/2 <= exp <= LONG_MAX/2 then there's no danger of
+     *   overflow in the calculation of exp and top_exp below.
+     *
+     * More specifically, ndigits is assumed to satisfy the following
+     * inequalities:
+     *
+     *   4*ndigits <= DBL_MIN_EXP - DBL_MANT_DIG - LONG_MIN/2
+     *   4*ndigits <= LONG_MAX/2 + 1 - DBL_MAX_EXP
+     *
+     * If either of these inequalities is not satisfied, a ValueError is
+     * raised.  Otherwise, write x for the value of the hex string, and
+     * assume x is nonzero.  Then
+     *
+     *   2**(exp-4*ndigits) <= |x| < 2**(exp+4*ndigits).
+     *
+     * Now if exp > LONG_MAX/2 then:
+     *
+     *   exp - 4*ndigits >= LONG_MAX/2 + 1 - (LONG_MAX/2 + 1 - DBL_MAX_EXP)
+     *                    = DBL_MAX_EXP
+     *
+     * so |x| >= 2**DBL_MAX_EXP, which is too large to be stored in C
+     * double, so overflows.  If exp < LONG_MIN/2, then
+     *
+     *   exp + 4*ndigits <= LONG_MIN/2 - 1 + (
+     *                      DBL_MIN_EXP - DBL_MANT_DIG - LONG_MIN/2)
+     *                    = DBL_MIN_EXP - DBL_MANT_DIG - 1
+     *
+     * and so |x| < 2**(DBL_MIN_EXP-DBL_MANT_DIG-1), hence underflows to 0
+     * when converted to a C double.
+     *
+     * It's easy to show that if LONG_MIN/2 <= exp <= LONG_MAX/2 then both
+     * exp+4*ndigits and exp-4*ndigits are within the range of a long.
+     */
+
+    s = PyUnicode_AsUTF8AndSize(string, &length);
+    if (s == NULL)
+        return NULL;
+    s_end = s + length;
+
+    /********************
+     * Parse the string *
+     ********************/
+
+    /* leading whitespace */
+    while (Py_ISSPACE(*s))
+        s++;
+
+    /* infinities and nans */
+    x = _Py_parse_inf_or_nan(s, (char **)&coeff_end);
+    if (coeff_end != s) {
+        s = coeff_end;
+        goto finished;
+    }
+
+    /* optional sign */
+    if (*s == '-') {
+        s++;
+        negate = 1;
+    }
+    else if (*s == '+')
+        s++;
+
+    /* [0x] */
+    s_store = s;
+    if (*s == '0') {
+        s++;
+        if (*s == 'x' || *s == 'X')
+            s++;
+        else
+            s = s_store;
+    }
+
+    /* coefficient: <integer> [. <fraction>] */
+    coeff_start = s;
+    while (hex_from_char(*s) >= 0)
+        s++;
+    s_store = s;
+    if (*s == '.') {
+        s++;
+        while (hex_from_char(*s) >= 0)
+            s++;
+        coeff_end = s-1;
+    }
+    else
+        coeff_end = s;
+
+    /* ndigits = total # of hex digits; fdigits = # after point */
+    ndigits = coeff_end - coeff_start;
+    fdigits = coeff_end - s_store;
+    if (ndigits == 0)
+        goto parse_error;
+    if (ndigits > Py_MIN(DBL_MIN_EXP - DBL_MANT_DIG - LONG_MIN/2,
+                         LONG_MAX/2 + 1 - DBL_MAX_EXP)/4)
+        goto insane_length_error;
+
+    /* [p <exponent>] */
+    if (*s == 'p' || *s == 'P') {
+        s++;
+        exp_start = s;
+        if (*s == '-' || *s == '+')
+            s++;
+        if (!('0' <= *s && *s <= '9'))
+            goto parse_error;
+        s++;
+        while ('0' <= *s && *s <= '9')
+            s++;
+        exp = strtol(exp_start, NULL, 10);
+    }
+    else
+        exp = 0;
+
+/* for 0 <= j < ndigits, HEX_DIGIT(j) gives the jth most significant digit */
+#define HEX_DIGIT(j) hex_from_char(*((j) < fdigits ?            \
+                     coeff_end-(j) :                                    \
+                     coeff_end-1-(j)))
+
+    /*******************************************
+     * Compute rounded value of the hex string *
+     *******************************************/
+
+    /* Discard leading zeros, and catch extreme overflow and underflow */
+    while (ndigits > 0 && HEX_DIGIT(ndigits-1) == 0)
+        ndigits--;
+    if (ndigits == 0 || exp < LONG_MIN/2) {
+        x = 0.0;
+        goto finished;
+    }
+    if (exp > LONG_MAX/2)
+        goto overflow_error;
+
+    /* Adjust exponent for fractional part. */
+    exp = exp - 4*((long)fdigits);
+
+    /* top_exp = 1 more than exponent of most sig. bit of coefficient */
+    top_exp = exp + 4*((long)ndigits - 1);
+    for (digit = HEX_DIGIT(ndigits-1); digit != 0; digit /= 2)
+        top_exp++;
+
+    /* catch almost all nonextreme cases of overflow and underflow here */
+    if (top_exp < DBL_MIN_EXP - DBL_MANT_DIG) {
+        x = 0.0;
+        goto finished;
+    }
+    if (top_exp > DBL_MAX_EXP)
+        goto overflow_error;
+
+    /* lsb = exponent of least significant bit of the *rounded* value.
+       This is top_exp - DBL_MANT_DIG unless result is subnormal. */
+    lsb = Py_MAX(top_exp, (long)DBL_MIN_EXP) - DBL_MANT_DIG;
+
+    x = 0.0;
+    if (exp >= lsb) {
+        /* no rounding required */
+        for (i = ndigits-1; i >= 0; i--)
+            x = 16.0*x + HEX_DIGIT(i);
+        x = ldexp(x, (int)(exp));
+        goto finished;
+    }
+    /* rounding required.  key_digit is the index of the hex digit
+       containing the first bit to be rounded away. */
+    half_eps = 1 << (int)((lsb - exp - 1) % 4);
+    key_digit = (lsb - exp - 1) / 4;
+    for (i = ndigits-1; i > key_digit; i--)
+        x = 16.0*x + HEX_DIGIT(i);
+    digit = HEX_DIGIT(key_digit);
+    x = 16.0*x + (double)(digit & (16-2*half_eps));
+
+    /* round-half-even: round up if bit lsb-1 is 1 and at least one of
+       bits lsb, lsb-2, lsb-3, lsb-4, ... is 1. */
+    if ((digit & half_eps) != 0) {
+        round_up = 0;
+        if ((digit & (3*half_eps-1)) != 0 || (half_eps == 8 &&
+                key_digit+1 < ndigits && (HEX_DIGIT(key_digit+1) & 1) != 0))
+            round_up = 1;
+        else
+            for (i = key_digit-1; i >= 0; i--)
+                if (HEX_DIGIT(i) != 0) {
+                    round_up = 1;
+                    break;
+                }
+        if (round_up) {
+            x += 2*half_eps;
+            if (top_exp == DBL_MAX_EXP &&
+                x == ldexp((double)(2*half_eps), DBL_MANT_DIG))
+                /* overflow corner case: pre-rounded value <
+                   2**DBL_MAX_EXP; rounded=2**DBL_MAX_EXP. */
+                goto overflow_error;
+        }
+    }
+    x = ldexp(x, (int)(exp+4*key_digit));
+
+  finished:
+    /* optional trailing whitespace leading to the end of the string */
+    while (Py_ISSPACE(*s))
+        s++;
+    if (s != s_end)
+        goto parse_error;
+    result = PyFloat_FromDouble(negate ? -x : x);
+    if (type != &PyFloat_Type && result != NULL) {
+        Py_SETREF(result, PyObject_CallOneArg((PyObject *)type, result));
+    }
+    return result;
+
+  overflow_error:
+    PyErr_SetString(PyExc_OverflowError,
+                    "hexadecimal value too large to represent as a float");
+    return NULL;
+
+  parse_error:
+    PyErr_SetString(PyExc_ValueError,
+                    "invalid hexadecimal floating-point string");
+    return NULL;
+
+  insane_length_error:
+    PyErr_SetString(PyExc_ValueError,
+                    "hexadecimal string too long to convert");
+    return NULL;
+}
+
+/*[clinic input]
+float.as_integer_ratio
+
+Return integer ratio.
+
+Return a pair of integers, whose ratio is exactly equal to the original float
+and with a positive denominator.
+
+Raise OverflowError on infinities and a ValueError on NaNs.
+
+>>> (10.0).as_integer_ratio()
+(10, 1)
+>>> (0.0).as_integer_ratio()
+(0, 1)
+>>> (-.25).as_integer_ratio()
+(-1, 4)
+[clinic start generated code]*/
+
+static PyObject *
+float_as_integer_ratio_impl(PyObject *self)
+/*[clinic end generated code: output=65f25f0d8d30a712 input=e21d08b4630c2e44]*/
+{
+    double self_double;
+    double float_part;
+    int exponent;
+    int i;
+
+    PyObject *py_exponent = NULL;
+    PyObject *numerator = NULL;
+    PyObject *denominator = NULL;
+    PyObject *result_pair = NULL;
+    PyNumberMethods *long_methods = PyLong_Type.tp_as_number;
+
+    CONVERT_TO_DOUBLE(self, self_double);
+
+    if (Py_IS_INFINITY(self_double)) {
+        PyErr_SetString(PyExc_OverflowError,
+                        "cannot convert Infinity to integer ratio");
+        return NULL;
+    }
+    if (Py_IS_NAN(self_double)) {
+        PyErr_SetString(PyExc_ValueError,
+                        "cannot convert NaN to integer ratio");
+        return NULL;
+    }
+
+    float_part = frexp(self_double, &exponent);        /* self_double == float_part * 2**exponent exactly */
+
+    for (i=0; i<300 && float_part != floor(float_part) ; i++) {
+        float_part *= 2.0;
+        exponent--;
+    }
+    /* self == float_part * 2**exponent exactly and float_part is integral.
+       If FLT_RADIX != 2, the 300 steps may leave a tiny fractional part
+       to be truncated by PyLong_FromDouble(). */
+
+    numerator = PyLong_FromDouble(float_part);
+    if (numerator == NULL)
+        goto error;
+    denominator = PyLong_FromLong(1);
+    if (denominator == NULL)
+        goto error;
+    py_exponent = PyLong_FromLong(Py_ABS(exponent));
+    if (py_exponent == NULL)
+        goto error;
+
+    /* fold in 2**exponent */
+    if (exponent > 0) {
+        Py_SETREF(numerator,
+                  long_methods->nb_lshift(numerator, py_exponent));
+        if (numerator == NULL)
+            goto error;
+    }
+    else {
+        Py_SETREF(denominator,
+                  long_methods->nb_lshift(denominator, py_exponent));
+        if (denominator == NULL)
+            goto error;
+    }
+
+    result_pair = PyTuple_Pack(2, numerator, denominator);
+
+error:
+    Py_XDECREF(py_exponent);
+    Py_XDECREF(denominator);
+    Py_XDECREF(numerator);
+    return result_pair;
+}
+
+static PyObject *
+float_subtype_new(PyTypeObject *type, PyObject *x);
+
+/*[clinic input]
+@classmethod
+float.__new__ as float_new
+    x: object(c_default="_PyLong_Zero") = 0
+    /
+
+Convert a string or number to a floating point number, if possible.
+[clinic start generated code]*/
+
+static PyObject *
+float_new_impl(PyTypeObject *type, PyObject *x)
+/*[clinic end generated code: output=ccf1e8dc460ba6ba input=540ee77c204ff87a]*/
+{
+    if (type != &PyFloat_Type)
+        return float_subtype_new(type, x); /* Wimp out */
+    /* If it's a string, but not a string subclass, use
+       PyFloat_FromString. */
+    if (PyUnicode_CheckExact(x))
+        return PyFloat_FromString(x);
+    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 *x)
+{
+    PyObject *tmp, *newobj;
+
+    assert(PyType_IsSubtype(type, &PyFloat_Type));
+    tmp = float_new_impl(&PyFloat_Type, x);
+    if (tmp == NULL)
+        return NULL;
+    assert(PyFloat_Check(tmp));
+    newobj = type->tp_alloc(type, 0);
+    if (newobj == NULL) {
+        Py_DECREF(tmp);
+        return NULL;
+    }
+    ((PyFloatObject *)newobj)->ob_fval = ((PyFloatObject *)tmp)->ob_fval;
+    Py_DECREF(tmp);
+    return newobj;
+}
+
+/*[clinic input]
+float.__getnewargs__
+[clinic start generated code]*/
+
+static PyObject *
+float___getnewargs___impl(PyObject *self)
+/*[clinic end generated code: output=873258c9d206b088 input=002279d1d77891e6]*/
+{
+    return Py_BuildValue("(d)", ((PyFloatObject *)self)->ob_fval);
+}
+
+/* this is for the benefit of the pack/unpack routines below */
+
+typedef enum {
+    unknown_format, ieee_big_endian_format, ieee_little_endian_format
+} float_format_type;
+
+static float_format_type double_format, float_format;
+static float_format_type detected_double_format, detected_float_format;
+
+/*[clinic input]
+@classmethod
+float.__getformat__
+
+    typestr: str
+        Must be 'double' or 'float'.
+    /
+
+You probably don't want to use this function.
+
+It exists mainly to be used in Python's test suite.
+
+This function returns whichever of 'unknown', 'IEEE, big-endian' or 'IEEE,
+little-endian' best describes the format of floating point numbers used by the
+C type named by typestr.
+[clinic start generated code]*/
+
+static PyObject *
+float___getformat___impl(PyTypeObject *type, const char *typestr)
+/*[clinic end generated code: output=2bfb987228cc9628 input=d5a52600f835ad67]*/
+{
+    float_format_type r;
+
+    if (strcmp(typestr, "double") == 0) {
+        r = double_format;
+    }
+    else if (strcmp(typestr, "float") == 0) {
+        r = float_format;
+    }
+    else {
+        PyErr_SetString(PyExc_ValueError,
+                        "__getformat__() argument 1 must be "
+                        "'double' or 'float'");
+        return NULL;
+    }
+
+    switch (r) {
+    case unknown_format:
+        return PyUnicode_FromString("unknown");
+    case ieee_little_endian_format:
+        return PyUnicode_FromString("IEEE, little-endian");
+    case ieee_big_endian_format:
+        return PyUnicode_FromString("IEEE, big-endian");
+    default:
+        PyErr_SetString(PyExc_RuntimeError,
+                        "insane float_format or double_format");
+        return NULL;
+    }
+}
+
+/*[clinic input]
+@classmethod
+float.__set_format__
+
+    typestr: str
+        Must be 'double' or 'float'.
+    fmt: str
+        Must be one of 'unknown', 'IEEE, big-endian' or 'IEEE, little-endian',
+        and in addition can only be one of the latter two if it appears to
+        match the underlying C reality.
+    /
+
+You probably don't want to use this function.
+
+It exists mainly to be used in Python's test suite.
+
+Override the automatic determination of C-level floating point type.
+This affects how floats are converted to and from binary strings.
+[clinic start generated code]*/
+
+static PyObject *
+float___set_format___impl(PyTypeObject *type, const char *typestr,
+                          const char *fmt)
+/*[clinic end generated code: output=504460f5dc85acbd input=5306fa2b81a997e4]*/
+{
+    float_format_type f;
+    float_format_type detected;
+    float_format_type *p;
+
+    if (strcmp(typestr, "double") == 0) {
+        p = &double_format;
+        detected = detected_double_format;
+    }
+    else if (strcmp(typestr, "float") == 0) {
+        p = &float_format;
+        detected = detected_float_format;
+    }
+    else {
+        PyErr_SetString(PyExc_ValueError,
+                        "__setformat__() argument 1 must "
+                        "be 'double' or 'float'");
+        return NULL;
+    }
+
+    if (strcmp(fmt, "unknown") == 0) {
+        f = unknown_format;
+    }
+    else if (strcmp(fmt, "IEEE, little-endian") == 0) {
+        f = ieee_little_endian_format;
+    }
+    else if (strcmp(fmt, "IEEE, big-endian") == 0) {
+        f = ieee_big_endian_format;
+    }
+    else {
+        PyErr_SetString(PyExc_ValueError,
+                        "__setformat__() argument 2 must be "
+                        "'unknown', 'IEEE, little-endian' or "
+                        "'IEEE, big-endian'");
+        return NULL;
+
+    }
+
+    if (f != unknown_format && f != detected) {
+        PyErr_Format(PyExc_ValueError,
+                     "can only set %s format to 'unknown' or the "
+                     "detected platform value", typestr);
+        return NULL;
+    }
+
+    *p = f;
+    Py_RETURN_NONE;
+}
+
+static PyObject *
+float_getreal(PyObject *v, void *closure)
+{
+    return float_float(v);
+}
+
+static PyObject *
+float_getimag(PyObject *v, void *closure)
+{
+    return PyFloat_FromDouble(0.0);
+}
+
+/*[clinic input]
+float.__format__
+
+  format_spec: unicode
+  /
+
+Formats the float according to format_spec.
+[clinic start generated code]*/
+
+static PyObject *
+float___format___impl(PyObject *self, PyObject *format_spec)
+/*[clinic end generated code: output=b260e52a47eade56 input=2ece1052211fd0e6]*/
+{
+    _PyUnicodeWriter writer;
+    int ret;
+
+    _PyUnicodeWriter_Init(&writer);
+    ret = _PyFloat_FormatAdvancedWriter(
+        &writer,
+        self,
+        format_spec, 0, PyUnicode_GET_LENGTH(format_spec));
+    if (ret == -1) {
+        _PyUnicodeWriter_Dealloc(&writer);
+        return NULL;
+    }
+    return _PyUnicodeWriter_Finish(&writer);
+}
+
+static PyMethodDef float_methods[] = {
+    FLOAT_CONJUGATE_METHODDEF
+    FLOAT___TRUNC___METHODDEF
+    FLOAT___FLOOR___METHODDEF
+    FLOAT___CEIL___METHODDEF
+    FLOAT___ROUND___METHODDEF
+    FLOAT_AS_INTEGER_RATIO_METHODDEF
+    FLOAT_FROMHEX_METHODDEF
+    FLOAT_HEX_METHODDEF
+    FLOAT_IS_INTEGER_METHODDEF
+    FLOAT___GETNEWARGS___METHODDEF
+    FLOAT___GETFORMAT___METHODDEF
+    FLOAT___SET_FORMAT___METHODDEF
+    FLOAT___FORMAT___METHODDEF
+    {NULL,              NULL}           /* sentinel */
+};
+
+static PyGetSetDef float_getset[] = {
+    {"real",
+     float_getreal, (setter)NULL,
+     "the real part of a complex number",
+     NULL},
+    {"imag",
+     float_getimag, (setter)NULL,
+     "the imaginary part of a complex number",
+     NULL},
+    {NULL}  /* Sentinel */
+};
+
+
+static PyNumberMethods float_as_number = {
+    float_add,          /* nb_add */
+    float_sub,          /* nb_subtract */
+    float_mul,          /* nb_multiply */
+    float_rem,          /* nb_remainder */
+    float_divmod,       /* nb_divmod */
+    float_pow,          /* nb_power */
+    (unaryfunc)float_neg, /* nb_negative */
+    float_float,        /* nb_positive */
+    (unaryfunc)float_abs, /* nb_absolute */
+    (inquiry)float_bool, /* nb_bool */
+    0,                  /* nb_invert */
+    0,                  /* nb_lshift */
+    0,                  /* nb_rshift */
+    0,                  /* nb_and */
+    0,                  /* nb_xor */
+    0,                  /* nb_or */
+    float___trunc___impl, /* nb_int */
+    0,                  /* nb_reserved */
+    float_float,        /* nb_float */
+    0,                  /* nb_inplace_add */
+    0,                  /* nb_inplace_subtract */
+    0,                  /* nb_inplace_multiply */
+    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 */
+};
+
+PyTypeObject PyFloat_Type = {
+    PyVarObject_HEAD_INIT(&PyType_Type, 0)
+    "float",
+    sizeof(PyFloatObject),
+    0,
+    (destructor)float_dealloc,                  /* tp_dealloc */
+    0,                                          /* tp_vectorcall_offset */
+    0,                                          /* tp_getattr */
+    0,                                          /* tp_setattr */
+    0,                                          /* tp_as_async */
+    (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 */
+    0,                                          /* tp_str */
+    PyObject_GenericGetAttr,                    /* tp_getattro */
+    0,                                          /* tp_setattro */
+    0,                                          /* tp_as_buffer */
+    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,   /* tp_flags */
+    float_new__doc__,                           /* tp_doc */
+    0,                                          /* tp_traverse */
+    0,                                          /* tp_clear */
+    float_richcompare,                          /* tp_richcompare */
+    0,                                          /* tp_weaklistoffset */
+    0,                                          /* tp_iter */
+    0,                                          /* tp_iternext */
+    float_methods,                              /* tp_methods */
+    0,                                          /* tp_members */
+    float_getset,                               /* 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 */
+};
+
+int
+_PyFloat_Init(void)
+{
+    /* We attempt to determine if this machine is using IEEE
+       floating point formats by peering at the bits of some
+       carefully chosen values.  If it looks like we are on an
+       IEEE platform, the float packing/unpacking routines can
+       just copy bits, if not they resort to arithmetic & shifts
+       and masks.  The shifts & masks approach works on all finite
+       values, but what happens to infinities, NaNs and signed
+       zeroes on packing is an accident, and attempting to unpack
+       a NaN or an infinity will raise an exception.
+
+       Note that if we're on some whacked-out platform which uses
+       IEEE formats but isn't strictly little-endian or big-
+       endian, we will fall back to the portable shifts & masks
+       method. */
+
+#if SIZEOF_DOUBLE == 8
+    {
+        double x = 9006104071832581.0;
+        if (memcmp(&x, "\x43\x3f\xff\x01\x02\x03\x04\x05", 8) == 0)
+            detected_double_format = ieee_big_endian_format;
+        else if (memcmp(&x, "\x05\x04\x03\x02\x01\xff\x3f\x43", 8) == 0)
+            detected_double_format = ieee_little_endian_format;
+        else
+            detected_double_format = unknown_format;
+    }
+#else
+    detected_double_format = unknown_format;
+#endif
+
+#if SIZEOF_FLOAT == 4
+    {
+        float y = 16711938.0;
+        if (memcmp(&y, "\x4b\x7f\x01\x02", 4) == 0)
+            detected_float_format = ieee_big_endian_format;
+        else if (memcmp(&y, "\x02\x01\x7f\x4b", 4) == 0)
+            detected_float_format = ieee_little_endian_format;
+        else
+            detected_float_format = unknown_format;
+    }
+#else
+    detected_float_format = unknown_format;
+#endif
+
+    double_format = detected_double_format;
+    float_format = detected_float_format;
+
+    /* Init float info */
+    if (FloatInfoType.tp_name == NULL) {
+        if (PyStructSequence_InitType2(&FloatInfoType, &floatinfo_desc) < 0) {
+            return 0;
+        }
+    }
+    return 1;
+}
+
+void
+_PyFloat_ClearFreeList(void)
+{
+    PyFloatObject *f = free_list, *next;
+    for (; f; f = next) {
+        next = (PyFloatObject*) Py_TYPE(f);
+        PyObject_FREE(f);
+    }
+    free_list = NULL;
+    numfree = 0;
+}
+
+void
+_PyFloat_Fini(void)
+{
+    _PyFloat_ClearFreeList();
+}
+
+/* Print summary info about the state of the optimized allocator */
+void
+_PyFloat_DebugMallocStats(FILE *out)
+{
+    _PyDebugAllocatorStats(out,
+                           "free PyFloatObject",
+                           numfree, sizeof(PyFloatObject));
+}
+
+
+/*----------------------------------------------------------------------------
+ * _PyFloat_{Pack,Unpack}{2,4,8}.  See floatobject.h.
+ * To match the NPY_HALF_ROUND_TIES_TO_EVEN behavior in:
+ * https://github.com/numpy/numpy/blob/master/numpy/core/src/npymath/halffloat.c
+ * We use:
+ *       bits = (unsigned short)f;    Note the truncation
+ *       if ((f - bits > 0.5) || (f - bits == 0.5 && bits % 2)) {
+ *           bits++;
+ *       }
+ */
+
+int
+_PyFloat_Pack2(double x, unsigned char *p, int le)
+{
+    unsigned char sign;
+    int e;
+    double f;
+    unsigned short bits;
+    int incr = 1;
+
+    if (x == 0.0) {
+        sign = (copysign(1.0, x) == -1.0);
+        e = 0;
+        bits = 0;
+    }
+    else if (Py_IS_INFINITY(x)) {
+        sign = (x < 0.0);
+        e = 0x1f;
+        bits = 0;
+    }
+    else if (Py_IS_NAN(x)) {
+        /* There are 2046 distinct half-precision NaNs (1022 signaling and
+           1024 quiet), but there are only two quiet NaNs that don't arise by
+           quieting a signaling NaN; we get those by setting the topmost bit
+           of the fraction field and clearing all other fraction bits. We
+           choose the one with the appropriate sign. */
+        sign = (copysign(1.0, x) == -1.0);
+        e = 0x1f;
+        bits = 512;
+    }
+    else {
+        sign = (x < 0.0);
+        if (sign) {
+            x = -x;
+        }
+
+        f = frexp(x, &e);
+        if (f < 0.5 || f >= 1.0) {
+            PyErr_SetString(PyExc_SystemError,
+                            "frexp() result out of range");
+            return -1;
+        }
+
+        /* Normalize f to be in the range [1.0, 2.0) */
+        f *= 2.0;
+        e--;
+
+        if (e >= 16) {
+            goto Overflow;
+        }
+        else if (e < -25) {
+            /* |x| < 2**-25. Underflow to zero. */
+            f = 0.0;
+            e = 0;
+        }
+        else if (e < -14) {
+            /* |x| < 2**-14. Gradual underflow */
+            f = ldexp(f, 14 + e);
+            e = 0;
+        }
+        else /* if (!(e == 0 && f == 0.0)) */ {
+            e += 15;
+            f -= 1.0; /* Get rid of leading 1 */
+        }
+
+        f *= 1024.0; /* 2**10 */
+        /* Round to even */
+        bits = (unsigned short)f; /* Note the truncation */
+        assert(bits < 1024);
+        assert(e < 31);
+        if ((f - bits > 0.5) || ((f - bits == 0.5) && (bits % 2 == 1))) {
+            ++bits;
+            if (bits == 1024) {
+                /* The carry propagated out of a string of 10 1 bits. */
+                bits = 0;
+                ++e;
+                if (e == 31)
+                    goto Overflow;
+            }
+        }
+    }
+
+    bits |= (e << 10) | (sign << 15);
+
+    /* Write out result. */
+    if (le) {
+        p += 1;
+        incr = -1;
+    }
+
+    /* First byte */
+    *p = (unsigned char)((bits >> 8) & 0xFF);
+    p += incr;
+
+    /* Second byte */
+    *p = (unsigned char)(bits & 0xFF);
+
+    return 0;
+
+  Overflow:
+    PyErr_SetString(PyExc_OverflowError,
+                    "float too large to pack with e format");
+    return -1;
+}
+
+int
+_PyFloat_Pack4(double x, unsigned char *p, int le)
+{
+    if (float_format == unknown_format) {
+        unsigned char sign;
+        int e;
+        double f;
+        unsigned int fbits;
+        int incr = 1;
+
+        if (le) {
+            p += 3;
+            incr = -1;
+        }
+
+        if (x < 0) {
+            sign = 1;
+            x = -x;
+        }
+        else
+            sign = 0;
+
+        f = frexp(x, &e);
+
+        /* Normalize f to be in the range [1.0, 2.0) */
+        if (0.5 <= f && f < 1.0) {
+            f *= 2.0;
+            e--;
+        }
+        else if (f == 0.0)
+            e = 0;
+        else {
+            PyErr_SetString(PyExc_SystemError,
+                            "frexp() result out of range");
+            return -1;
+        }
+
+        if (e >= 128)
+            goto Overflow;
+        else if (e < -126) {
+            /* Gradual underflow */
+            f = ldexp(f, 126 + e);
+            e = 0;
+        }
+        else if (!(e == 0 && f == 0.0)) {
+            e += 127;
+            f -= 1.0; /* Get rid of leading 1 */
+        }
+
+        f *= 8388608.0; /* 2**23 */
+        fbits = (unsigned int)(f + 0.5); /* Round */
+        assert(fbits <= 8388608);
+        if (fbits >> 23) {
+            /* The carry propagated out of a string of 23 1 bits. */
+            fbits = 0;
+            ++e;
+            if (e >= 255)
+                goto Overflow;
+        }
+
+        /* First byte */
+        *p = (sign << 7) | (e >> 1);
+        p += incr;
+
+        /* Second byte */
+        *p = (char) (((e & 1) << 7) | (fbits >> 16));
+        p += incr;
+
+        /* Third byte */
+        *p = (fbits >> 8) & 0xFF;
+        p += incr;
+
+        /* Fourth byte */
+        *p = fbits & 0xFF;
+
+        /* Done */
+        return 0;
+
+    }
+    else {
+        float y = (float)x;
+        int i, incr = 1;
+
+        if (Py_IS_INFINITY(y) && !Py_IS_INFINITY(x))
+            goto Overflow;
+
+        unsigned char s[sizeof(float)];
+        memcpy(s, &y, sizeof(float));
+
+        if ((float_format == ieee_little_endian_format && !le)
+            || (float_format == ieee_big_endian_format && le)) {
+            p += 3;
+            incr = -1;
+        }
+
+        for (i = 0; i < 4; i++) {
+            *p = s[i];
+            p += incr;
+        }
+        return 0;
+    }
+  Overflow:
+    PyErr_SetString(PyExc_OverflowError,
+                    "float too large to pack with f format");
+    return -1;
+}
+
+int
+_PyFloat_Pack8(double x, unsigned char *p, int le)
+{
+    if (double_format == unknown_format) {
+        unsigned char sign;
+        int e;
+        double f;
+        unsigned int fhi, flo;
+        int incr = 1;
+
+        if (le) {
+            p += 7;
+            incr = -1;
+        }
+
+        if (x < 0) {
+            sign = 1;
+            x = -x;
+        }
+        else
+            sign = 0;
+
+        f = frexp(x, &e);
+
+        /* Normalize f to be in the range [1.0, 2.0) */
+        if (0.5 <= f && f < 1.0) {
+            f *= 2.0;
+            e--;
+        }
+        else if (f == 0.0)
+            e = 0;
+        else {
+            PyErr_SetString(PyExc_SystemError,
+                            "frexp() result out of range");
+            return -1;
+        }
+
+        if (e >= 1024)
+            goto Overflow;
+        else if (e < -1022) {
+            /* Gradual underflow */
+            f = ldexp(f, 1022 + e);
+            e = 0;
+        }
+        else if (!(e == 0 && f == 0.0)) {
+            e += 1023;
+            f -= 1.0; /* Get rid of leading 1 */
+        }
+
+        /* fhi receives the high 28 bits; flo the low 24 bits (== 52 bits) */
+        f *= 268435456.0; /* 2**28 */
+        fhi = (unsigned int)f; /* Truncate */
+        assert(fhi < 268435456);
+
+        f -= (double)fhi;
+        f *= 16777216.0; /* 2**24 */
+        flo = (unsigned int)(f + 0.5); /* Round */
+        assert(flo <= 16777216);
+        if (flo >> 24) {
+            /* The carry propagated out of a string of 24 1 bits. */
+            flo = 0;
+            ++fhi;
+            if (fhi >> 28) {
+                /* And it also propagated out of the next 28 bits. */
+                fhi = 0;
+                ++e;
+                if (e >= 2047)
+                    goto Overflow;
+            }
+        }
+
+        /* First byte */
+        *p = (sign << 7) | (e >> 4);
+        p += incr;
+
+        /* Second byte */
+        *p = (unsigned char) (((e & 0xF) << 4) | (fhi >> 24));
+        p += incr;
+
+        /* Third byte */
+        *p = (fhi >> 16) & 0xFF;
+        p += incr;
+
+        /* Fourth byte */
+        *p = (fhi >> 8) & 0xFF;
+        p += incr;
+
+        /* Fifth byte */
+        *p = fhi & 0xFF;
+        p += incr;
+
+        /* Sixth byte */
+        *p = (flo >> 16) & 0xFF;
+        p += incr;
+
+        /* Seventh byte */
+        *p = (flo >> 8) & 0xFF;
+        p += incr;
+
+        /* Eighth byte */
+        *p = flo & 0xFF;
+        /* p += incr; */
+
+        /* Done */
+        return 0;
+
+      Overflow:
+        PyErr_SetString(PyExc_OverflowError,
+                        "float too large to pack with d format");
+        return -1;
+    }
+    else {
+        const unsigned char *s = (unsigned char*)&x;
+        int i, incr = 1;
+
+        if ((double_format == ieee_little_endian_format && !le)
+            || (double_format == ieee_big_endian_format && le)) {
+            p += 7;
+            incr = -1;
+        }
+
+        for (i = 0; i < 8; i++) {
+            *p = *s++;
+            p += incr;
+        }
+        return 0;
+    }
+}
+
+double
+_PyFloat_Unpack2(const unsigned char *p, int le)
+{
+    unsigned char sign;
+    int e;
+    unsigned int f;
+    double x;
+    int incr = 1;
+
+    if (le) {
+        p += 1;
+        incr = -1;
+    }
+
+    /* First byte */
+    sign = (*p >> 7) & 1;
+    e = (*p & 0x7C) >> 2;
+    f = (*p & 0x03) << 8;
+    p += incr;
+
+    /* Second byte */
+    f |= *p;
+
+    if (e == 0x1f) {
+#ifdef PY_NO_SHORT_FLOAT_REPR
+        if (f == 0) {
+            /* Infinity */
+            return sign ? -Py_HUGE_VAL : Py_HUGE_VAL;
+        }
+        else {
+            /* NaN */
+#ifdef Py_NAN
+            return sign ? -Py_NAN : Py_NAN;
+#else
+            PyErr_SetString(
+                PyExc_ValueError,
+                "can't unpack IEEE 754 NaN "
+                "on platform that does not support NaNs");
+            return -1;
+#endif  /* #ifdef Py_NAN */
+        }
+#else
+        if (f == 0) {
+            /* Infinity */
+            return _Py_dg_infinity(sign);
+        }
+        else {
+            /* NaN */
+            return _Py_dg_stdnan(sign);
+        }
+#endif  /* #ifdef PY_NO_SHORT_FLOAT_REPR */
+    }
+
+    x = (double)f / 1024.0;
+
+    if (e == 0) {
+        e = -14;
+    }
+    else {
+        x += 1.0;
+        e -= 15;
+    }
+    x = ldexp(x, e);
+
+    if (sign)
+        x = -x;
+
+    return x;
+}
+
+double
+_PyFloat_Unpack4(const unsigned char *p, int le)
+{
+    if (float_format == unknown_format) {
+        unsigned char sign;
+        int e;
+        unsigned int f;
+        double x;
+        int incr = 1;
+
+        if (le) {
+            p += 3;
+            incr = -1;
+        }
+
+        /* First byte */
+        sign = (*p >> 7) & 1;
+        e = (*p & 0x7F) << 1;
+        p += incr;
+
+        /* Second byte */
+        e |= (*p >> 7) & 1;
+        f = (*p & 0x7F) << 16;
+        p += incr;
+
+        if (e == 255) {
+            PyErr_SetString(
+                PyExc_ValueError,
+                "can't unpack IEEE 754 special value "
+                "on non-IEEE platform");
+            return -1;
+        }
+
+        /* Third byte */
+        f |= *p << 8;
+        p += incr;
+
+        /* Fourth byte */
+        f |= *p;
+
+        x = (double)f / 8388608.0;
+
+        /* XXX This sadly ignores Inf/NaN issues */
+        if (e == 0)
+            e = -126;
+        else {
+            x += 1.0;
+            e -= 127;
+        }
+        x = ldexp(x, e);
+
+        if (sign)
+            x = -x;
+
+        return x;
+    }
+    else {
+        float x;
+
+        if ((float_format == ieee_little_endian_format && !le)
+            || (float_format == ieee_big_endian_format && le)) {
+            char buf[4];
+            char *d = &buf[3];
+            int i;
+
+            for (i = 0; i < 4; i++) {
+                *d-- = *p++;
+            }
+            memcpy(&x, buf, 4);
+        }
+        else {
+            memcpy(&x, p, 4);
+        }
+
+        return x;
+    }
+}
+
+double
+_PyFloat_Unpack8(const unsigned char *p, int le)
+{
+    if (double_format == unknown_format) {
+        unsigned char sign;
+        int e;
+        unsigned int fhi, flo;
+        double x;
+        int incr = 1;
+
+        if (le) {
+            p += 7;
+            incr = -1;
+        }
+
+        /* First byte */
+        sign = (*p >> 7) & 1;
+        e = (*p & 0x7F) << 4;
+
+        p += incr;
+
+        /* Second byte */
+        e |= (*p >> 4) & 0xF;
+        fhi = (*p & 0xF) << 24;
+        p += incr;
+
+        if (e == 2047) {
+            PyErr_SetString(
+                PyExc_ValueError,
+                "can't unpack IEEE 754 special value "
+                "on non-IEEE platform");
+            return -1.0;
+        }
+
+        /* Third byte */
+        fhi |= *p << 16;
+        p += incr;
+
+        /* Fourth byte */
+        fhi |= *p  << 8;
+        p += incr;
+
+        /* Fifth byte */
+        fhi |= *p;
+        p += incr;
+
+        /* Sixth byte */
+        flo = *p << 16;
+        p += incr;
+
+        /* Seventh byte */
+        flo |= *p << 8;
+        p += incr;
+
+        /* Eighth byte */
+        flo |= *p;
+
+        x = (double)fhi + (double)flo / 16777216.0; /* 2**24 */
+        x /= 268435456.0; /* 2**28 */
+
+        if (e == 0)
+            e = -1022;
+        else {
+            x += 1.0;
+            e -= 1023;
+        }
+        x = ldexp(x, e);
+
+        if (sign)
+            x = -x;
+
+        return x;
+    }
+    else {
+        double x;
+
+        if ((double_format == ieee_little_endian_format && !le)
+            || (double_format == ieee_big_endian_format && le)) {
+            char buf[8];
+            char *d = &buf[7];
+            int i;
+
+            for (i = 0; i < 8; i++) {
+                *d-- = *p++;
+            }
+            memcpy(&x, buf, 8);
+        }
+        else {
+            memcpy(&x, p, 8);
+        }
+
+        return x;
+    }
+}