[Python-checkins] GH-100485: Add math.sumprod() (GH-100677)
rhettinger
webhook-mailer at python.org
Sat Jan 7 13:46:50 EST 2023
https://github.com/python/cpython/commit/47b9f83a83db288c652e43567c7b0f74d87a29be
commit: 47b9f83a83db288c652e43567c7b0f74d87a29be
branch: main
author: Raymond Hettinger <rhettinger at users.noreply.github.com>
committer: rhettinger <rhettinger at users.noreply.github.com>
date: 2023-01-07T12:46:35-06:00
summary:
GH-100485: Add math.sumprod() (GH-100677)
files:
A Misc/NEWS.d/next/Library/2023-01-01-21-54-46.gh-issue-100485.geNrHS.rst
M Doc/library/itertools.rst
M Doc/library/math.rst
M Lib/test/test_math.py
M Modules/clinic/mathmodule.c.h
M Modules/mathmodule.c
diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst
index 4ad679dfccdb..e7d2e13626fa 100644
--- a/Doc/library/itertools.rst
+++ b/Doc/library/itertools.rst
@@ -33,7 +33,7 @@ by combining :func:`map` and :func:`count` to form ``map(f, count())``.
These tools and their built-in counterparts also work well with the high-speed
functions in the :mod:`operator` module. For example, the multiplication
operator can be mapped across two vectors to form an efficient dot-product:
-``sum(map(operator.mul, vector1, vector2))``.
+``sum(starmap(operator.mul, zip(vec1, vec2, strict=True)))``.
**Infinite iterators:**
@@ -838,10 +838,6 @@ which incur interpreter overhead.
"Returns the sequence elements n times"
return chain.from_iterable(repeat(tuple(iterable), n))
- def dotproduct(vec1, vec2):
- "Compute a sum of products."
- return sum(starmap(operator.mul, zip(vec1, vec2, strict=True)))
-
def convolve(signal, kernel):
# See: https://betterexplained.com/articles/intuitive-convolution/
# convolve(data, [0.25, 0.25, 0.25, 0.25]) --> Moving average (blur)
@@ -852,7 +848,7 @@ which incur interpreter overhead.
window = collections.deque([0], maxlen=n) * n
for x in chain(signal, repeat(0, n-1)):
window.append(x)
- yield dotproduct(kernel, window)
+ yield math.sumprod(kernel, window)
def polynomial_from_roots(roots):
"""Compute a polynomial's coefficients from its roots.
@@ -1211,9 +1207,6 @@ which incur interpreter overhead.
>>> list(ncycles('abc', 3))
['a', 'b', 'c', 'a', 'b', 'c', 'a', 'b', 'c']
- >>> dotproduct([1,2,3], [4,5,6])
- 32
-
>>> data = [20, 40, 24, 32, 20, 28, 16]
>>> list(convolve(data, [0.25, 0.25, 0.25, 0.25]))
[5.0, 15.0, 21.0, 29.0, 29.0, 26.0, 24.0, 16.0, 11.0, 4.0]
diff --git a/Doc/library/math.rst b/Doc/library/math.rst
index aeebcaf6ab08..0e888c4d4e42 100644
--- a/Doc/library/math.rst
+++ b/Doc/library/math.rst
@@ -291,6 +291,22 @@ Number-theoretic and representation functions
.. versionadded:: 3.7
+.. function:: sumprod(p, q)
+
+ Return the sum of products of values from two iterables *p* and *q*.
+
+ Raises :exc:`ValueError` if the inputs do not have the same length.
+
+ Roughly equivalent to::
+
+ sum(itertools.starmap(operator.mul, zip(p, q, strict=true)))
+
+ For float and mixed int/float inputs, the intermediate products
+ and sums are computed with extended precision.
+
+ .. versionadded:: 3.12
+
+
.. function:: trunc(x)
Return *x* with the fractional part
diff --git a/Lib/test/test_math.py b/Lib/test/test_math.py
index bf0d0a56e6ac..65fe169671ea 100644
--- a/Lib/test/test_math.py
+++ b/Lib/test/test_math.py
@@ -4,6 +4,7 @@
from test.support import verbose, requires_IEEE_754
from test import support
import unittest
+import fractions
import itertools
import decimal
import math
@@ -1202,6 +1203,171 @@ def testLog10(self):
self.assertEqual(math.log(INF), INF)
self.assertTrue(math.isnan(math.log10(NAN)))
+ def testSumProd(self):
+ sumprod = math.sumprod
+ Decimal = decimal.Decimal
+ Fraction = fractions.Fraction
+
+ # Core functionality
+ self.assertEqual(sumprod(iter([10, 20, 30]), (1, 2, 3)), 140)
+ self.assertEqual(sumprod([1.5, 2.5], [3.5, 4.5]), 16.5)
+ self.assertEqual(sumprod([], []), 0)
+
+ # Type preservation and coercion
+ for v in [
+ (10, 20, 30),
+ (1.5, -2.5),
+ (Fraction(3, 5), Fraction(4, 5)),
+ (Decimal(3.5), Decimal(4.5)),
+ (2.5, 10), # float/int
+ (2.5, Fraction(3, 5)), # float/fraction
+ (25, Fraction(3, 5)), # int/fraction
+ (25, Decimal(4.5)), # int/decimal
+ ]:
+ for p, q in [(v, v), (v, v[::-1])]:
+ with self.subTest(p=p, q=q):
+ expected = sum(p_i * q_i for p_i, q_i in zip(p, q, strict=True))
+ actual = sumprod(p, q)
+ self.assertEqual(expected, actual)
+ self.assertEqual(type(expected), type(actual))
+
+ # Bad arguments
+ self.assertRaises(TypeError, sumprod) # No args
+ self.assertRaises(TypeError, sumprod, []) # One arg
+ self.assertRaises(TypeError, sumprod, [], [], []) # Three args
+ self.assertRaises(TypeError, sumprod, None, [10]) # Non-iterable
+ self.assertRaises(TypeError, sumprod, [10], None) # Non-iterable
+
+ # Uneven lengths
+ self.assertRaises(ValueError, sumprod, [10, 20], [30])
+ self.assertRaises(ValueError, sumprod, [10], [20, 30])
+
+ # Error in iterator
+ def raise_after(n):
+ for i in range(n):
+ yield i
+ raise RuntimeError
+ with self.assertRaises(RuntimeError):
+ sumprod(range(10), raise_after(5))
+ with self.assertRaises(RuntimeError):
+ sumprod(raise_after(5), range(10))
+
+ # Error in multiplication
+ class BadMultiply:
+ def __mul__(self, other):
+ raise RuntimeError
+ def __rmul__(self, other):
+ raise RuntimeError
+ with self.assertRaises(RuntimeError):
+ sumprod([10, BadMultiply(), 30], [1, 2, 3])
+ with self.assertRaises(RuntimeError):
+ sumprod([1, 2, 3], [10, BadMultiply(), 30])
+
+ # Error in addition
+ with self.assertRaises(TypeError):
+ sumprod(['abc', 3], [5, 10])
+ with self.assertRaises(TypeError):
+ sumprod([5, 10], ['abc', 3])
+
+ # Special values should give the same as the pure python recipe
+ self.assertEqual(sumprod([10.1, math.inf], [20.2, 30.3]), math.inf)
+ self.assertEqual(sumprod([10.1, math.inf], [math.inf, 30.3]), math.inf)
+ self.assertEqual(sumprod([10.1, math.inf], [math.inf, math.inf]), math.inf)
+ self.assertEqual(sumprod([10.1, -math.inf], [20.2, 30.3]), -math.inf)
+ self.assertTrue(math.isnan(sumprod([10.1, math.inf], [-math.inf, math.inf])))
+ self.assertTrue(math.isnan(sumprod([10.1, math.nan], [20.2, 30.3])))
+ self.assertTrue(math.isnan(sumprod([10.1, math.inf], [math.nan, 30.3])))
+ self.assertTrue(math.isnan(sumprod([10.1, math.inf], [20.3, math.nan])))
+
+ # Error cases that arose during development
+ args = ((-5, -5, 10), (1.5, 4611686018427387904, 2305843009213693952))
+ self.assertEqual(sumprod(*args), 0.0)
+
+
+ @requires_IEEE_754
+ @unittest.skipIf(HAVE_DOUBLE_ROUNDING,
+ "sumprod() accuracy not guaranteed on machines with double rounding")
+ @support.cpython_only # Other implementations may choose a different algorithm
+ def test_sumprod_accuracy(self):
+ sumprod = math.sumprod
+ self.assertEqual(sumprod([0.1] * 10, [1]*10), 1.0)
+ self.assertEqual(sumprod([0.1] * 20, [True, False] * 10), 1.0)
+ self.assertEqual(sumprod([1.0, 10E100, 1.0, -10E100], [1.0]*4), 2.0)
+
+ def test_sumprod_stress(self):
+ sumprod = math.sumprod
+ product = itertools.product
+ Decimal = decimal.Decimal
+ Fraction = fractions.Fraction
+
+ class Int(int):
+ def __add__(self, other):
+ return Int(int(self) + int(other))
+ def __mul__(self, other):
+ return Int(int(self) * int(other))
+ __radd__ = __add__
+ __rmul__ = __mul__
+ def __repr__(self):
+ return f'Int({int(self)})'
+
+ class Flt(float):
+ def __add__(self, other):
+ return Int(int(self) + int(other))
+ def __mul__(self, other):
+ return Int(int(self) * int(other))
+ __radd__ = __add__
+ __rmul__ = __mul__
+ def __repr__(self):
+ return f'Flt({int(self)})'
+
+ def baseline_sumprod(p, q):
+ """This defines the target behavior including expections and special values.
+ However, it is subject to rounding errors, so float inputs should be exactly
+ representable with only a few bits.
+ """
+ total = 0
+ for p_i, q_i in zip(p, q, strict=True):
+ total += p_i * q_i
+ return total
+
+ def run(func, *args):
+ "Make comparing functions easier. Returns error status, type, and result."
+ try:
+ result = func(*args)
+ except (AssertionError, NameError):
+ raise
+ except Exception as e:
+ return type(e), None, 'None'
+ return None, type(result), repr(result)
+
+ pools = [
+ (-5, 10, -2**20, 2**31, 2**40, 2**61, 2**62, 2**80, 1.5, Int(7)),
+ (5.25, -3.5, 4.75, 11.25, 400.5, 0.046875, 0.25, -1.0, -0.078125),
+ (-19.0*2**500, 11*2**1000, -3*2**1500, 17*2*333,
+ 5.25, -3.25, -3.0*2**(-333), 3, 2**513),
+ (3.75, 2.5, -1.5, float('inf'), -float('inf'), float('NaN'), 14,
+ 9, 3+4j, Flt(13), 0.0),
+ (13.25, -4.25, Decimal('10.5'), Decimal('-2.25'), Fraction(13, 8),
+ Fraction(-11, 16), 4.75 + 0.125j, 97, -41, Int(3)),
+ (Decimal('6.125'), Decimal('12.375'), Decimal('-2.75'), Decimal(0),
+ Decimal('Inf'), -Decimal('Inf'), Decimal('NaN'), 12, 13.5),
+ (-2.0 ** -1000, 11*2**1000, 3, 7, -37*2**32, -2*2**-537, -2*2**-538,
+ 2*2**-513),
+ (-7 * 2.0 ** -510, 5 * 2.0 ** -520, 17, -19.0, -6.25),
+ (11.25, -3.75, -0.625, 23.375, True, False, 7, Int(5)),
+ ]
+
+ for pool in pools:
+ for size in range(4):
+ for args1 in product(pool, repeat=size):
+ for args2 in product(pool, repeat=size):
+ args = (args1, args2)
+ self.assertEqual(
+ run(baseline_sumprod, *args),
+ run(sumprod, *args),
+ args,
+ )
+
def testModf(self):
self.assertRaises(TypeError, math.modf)
diff --git a/Misc/NEWS.d/next/Library/2023-01-01-21-54-46.gh-issue-100485.geNrHS.rst b/Misc/NEWS.d/next/Library/2023-01-01-21-54-46.gh-issue-100485.geNrHS.rst
new file mode 100644
index 000000000000..9f6e593113bb
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2023-01-01-21-54-46.gh-issue-100485.geNrHS.rst
@@ -0,0 +1 @@
+Add math.sumprod() to compute the sum of products.
diff --git a/Modules/clinic/mathmodule.c.h b/Modules/clinic/mathmodule.c.h
index 9fac1037e525..1f9725883b98 100644
--- a/Modules/clinic/mathmodule.c.h
+++ b/Modules/clinic/mathmodule.c.h
@@ -333,6 +333,43 @@ math_dist(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
return return_value;
}
+PyDoc_STRVAR(math_sumprod__doc__,
+"sumprod($module, p, q, /)\n"
+"--\n"
+"\n"
+"Return the sum of products of values from two iterables p and q.\n"
+"\n"
+"Roughly equivalent to:\n"
+"\n"
+" sum(itertools.starmap(operator.mul, zip(p, q, strict=True)))\n"
+"\n"
+"For float and mixed int/float inputs, the intermediate products\n"
+"and sums are computed with extended precision.");
+
+#define MATH_SUMPROD_METHODDEF \
+ {"sumprod", _PyCFunction_CAST(math_sumprod), METH_FASTCALL, math_sumprod__doc__},
+
+static PyObject *
+math_sumprod_impl(PyObject *module, PyObject *p, PyObject *q);
+
+static PyObject *
+math_sumprod(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
+{
+ PyObject *return_value = NULL;
+ PyObject *p;
+ PyObject *q;
+
+ if (!_PyArg_CheckPositional("sumprod", nargs, 2, 2)) {
+ goto exit;
+ }
+ p = args[0];
+ q = args[1];
+ return_value = math_sumprod_impl(module, p, q);
+
+exit:
+ return return_value;
+}
+
PyDoc_STRVAR(math_pow__doc__,
"pow($module, x, y, /)\n"
"--\n"
@@ -917,4 +954,4 @@ math_ulp(PyObject *module, PyObject *arg)
exit:
return return_value;
}
-/*[clinic end generated code: output=c2c2f42452d63734 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=899211ec70e4506c input=a9049054013a1b77]*/
diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index 49c0293d4f5c..0bcb336efbb0 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -68,6 +68,7 @@ raised for division by zero and mod by zero.
#include <float.h>
/* For _Py_log1p with workarounds for buggy handling of zeros. */
#include "_math.h"
+#include <stdbool.h>
#include "clinic/mathmodule.c.h"
@@ -2819,6 +2820,329 @@ For example, the hypotenuse of a 3/4/5 right triangle is:\n\
5.0\n\
");
+/** sumprod() ***************************************************************/
+
+/* Forward declaration */
+static inline int _check_long_mult_overflow(long a, long b);
+
+static inline bool
+long_add_would_overflow(long a, long b)
+{
+ return (a > 0) ? (b > LONG_MAX - a) : (b < LONG_MIN - a);
+}
+
+/*
+Double length extended precision floating point arithmetic
+based on ideas from three sources:
+
+ Improved Kahan–Babuška algorithm by Arnold Neumaier
+ https://www.mat.univie.ac.at/~neum/scan/01.pdf
+
+ A Floating-Point Technique for Extending the Available Precision
+ by T. J. Dekker
+ https://csclub.uwaterloo.ca/~pbarfuss/dekker1971.pdf
+
+ Ultimately Fast Accurate Summation by Siegfried M. Rump
+ https://www.tuhh.de/ti3/paper/rump/Ru08b.pdf
+
+The double length routines allow for quite a bit of instruction
+level parallelism. On a 3.22 Ghz Apple M1 Max, the incremental
+cost of increasing the input vector size by one is 6.25 nsec.
+
+dl_zero() returns an extended precision zero
+dl_split() exactly splits a double into two half precision components.
+dl_add() performs compensated summation to keep a running total.
+dl_mul() implements lossless multiplication of doubles.
+dl_fma() implements an extended precision fused-multiply-add.
+dl_to_d() converts from extended precision to double precision.
+
+*/
+
+typedef struct{ double hi; double lo; } DoubleLength;
+
+static inline DoubleLength
+dl_zero()
+{
+ return (DoubleLength) {0.0, 0.0};
+}
+static inline DoubleLength
+dl_add(DoubleLength total, double x)
+{
+ double s = total.hi + x;
+ double c = total.lo;
+ if (fabs(total.hi) >= fabs(x)) {
+ c += (total.hi - s) + x;
+ } else {
+ c += (x - s) + total.hi;
+ }
+ return (DoubleLength) {s, c};
+}
+
+static inline DoubleLength
+dl_split(double x) {
+ double t = x * 134217729.0; /* Veltkamp constant = float(0x8000001) */
+ double hi = t - (t - x);
+ double lo = x - hi;
+ return (DoubleLength) {hi, lo};
+}
+
+static inline DoubleLength
+dl_mul(double x, double y)
+{
+ /* Dekker mul12(). Section (5.12) */
+ DoubleLength xx = dl_split(x);
+ DoubleLength yy = dl_split(y);
+ double p = xx.hi * yy.hi;
+ double q = xx.hi * yy.lo + xx.lo * yy.hi;
+ double z = p + q;
+ double zz = p - z + q + xx.lo * yy.lo;
+ return (DoubleLength) {z, zz};
+}
+
+static inline DoubleLength
+dl_fma(DoubleLength total, double p, double q)
+{
+ DoubleLength product = dl_mul(p, q);
+ total = dl_add(total, product.hi);
+ return dl_add(total, product.lo);
+}
+
+static inline double
+dl_to_d(DoubleLength total)
+{
+ return total.hi + total.lo;
+}
+
+/*[clinic input]
+math.sumprod
+
+ p: object
+ q: object
+ /
+
+Return the sum of products of values from two iterables p and q.
+
+Roughly equivalent to:
+
+ sum(itertools.starmap(operator.mul, zip(p, q, strict=True)))
+
+For float and mixed int/float inputs, the intermediate products
+and sums are computed with extended precision.
+[clinic start generated code]*/
+
+static PyObject *
+math_sumprod_impl(PyObject *module, PyObject *p, PyObject *q)
+/*[clinic end generated code: output=6722dbfe60664554 input=82be54fe26f87e30]*/
+{
+ PyObject *p_i = NULL, *q_i = NULL, *term_i = NULL, *new_total = NULL;
+ PyObject *p_it, *q_it, *total;
+ iternextfunc p_next, q_next;
+ bool p_stopped = false, q_stopped = false;
+ bool int_path_enabled = true, int_total_in_use = false;
+ bool flt_path_enabled = true, flt_total_in_use = false;
+ long int_total = 0;
+ DoubleLength flt_total = dl_zero();
+
+ p_it = PyObject_GetIter(p);
+ if (p_it == NULL) {
+ return NULL;
+ }
+ q_it = PyObject_GetIter(q);
+ if (q_it == NULL) {
+ Py_DECREF(p_it);
+ return NULL;
+ }
+ total = PyLong_FromLong(0);
+ if (total == NULL) {
+ Py_DECREF(p_it);
+ Py_DECREF(q_it);
+ return NULL;
+ }
+ p_next = *Py_TYPE(p_it)->tp_iternext;
+ q_next = *Py_TYPE(q_it)->tp_iternext;
+ while (1) {
+ bool finished;
+
+ assert (p_i == NULL);
+ assert (q_i == NULL);
+ assert (term_i == NULL);
+ assert (new_total == NULL);
+
+ assert (p_it != NULL);
+ assert (q_it != NULL);
+ assert (total != NULL);
+
+ p_i = p_next(p_it);
+ if (p_i == NULL) {
+ if (PyErr_Occurred()) {
+ if (!PyErr_ExceptionMatches(PyExc_StopIteration)) {
+ goto err_exit;
+ }
+ PyErr_Clear();
+ }
+ p_stopped = true;
+ }
+ q_i = q_next(q_it);
+ if (q_i == NULL) {
+ if (PyErr_Occurred()) {
+ if (!PyErr_ExceptionMatches(PyExc_StopIteration)) {
+ goto err_exit;
+ }
+ PyErr_Clear();
+ }
+ q_stopped = true;
+ }
+ if (p_stopped != q_stopped) {
+ PyErr_Format(PyExc_ValueError, "Inputs are not the same length");
+ goto err_exit;
+ }
+ finished = p_stopped & q_stopped;
+
+ if (int_path_enabled) {
+
+ if (!finished && PyLong_CheckExact(p_i) & PyLong_CheckExact(q_i)) {
+ int overflow;
+ long int_p, int_q, int_prod;
+
+ int_p = PyLong_AsLongAndOverflow(p_i, &overflow);
+ if (overflow) {
+ goto finalize_int_path;
+ }
+ int_q = PyLong_AsLongAndOverflow(q_i, &overflow);
+ if (overflow) {
+ goto finalize_int_path;
+ }
+ if (_check_long_mult_overflow(int_p, int_q)) {
+ goto finalize_int_path;
+ }
+ int_prod = int_p * int_q;
+ if (long_add_would_overflow(int_total, int_prod)) {
+ goto finalize_int_path;
+ }
+ int_total += int_prod;
+ int_total_in_use = true;
+ Py_CLEAR(p_i);
+ Py_CLEAR(q_i);
+ continue;
+ }
+
+ finalize_int_path:
+ // # We're finished, overflowed, or have a non-int
+ int_path_enabled = false;
+ if (int_total_in_use) {
+ term_i = PyLong_FromLong(int_total);
+ if (term_i == NULL) {
+ goto err_exit;
+ }
+ new_total = PyNumber_Add(total, term_i);
+ if (new_total == NULL) {
+ goto err_exit;
+ }
+ Py_SETREF(total, new_total);
+ new_total = NULL;
+ Py_CLEAR(term_i);
+ int_total = 0; // An ounce of prevention, ...
+ int_total_in_use = false;
+ }
+ }
+
+ if (flt_path_enabled) {
+
+ if (!finished) {
+ double flt_p, flt_q;
+ bool p_type_float = PyFloat_CheckExact(p_i);
+ bool q_type_float = PyFloat_CheckExact(q_i);
+ if (p_type_float && q_type_float) {
+ flt_p = PyFloat_AS_DOUBLE(p_i);
+ flt_q = PyFloat_AS_DOUBLE(q_i);
+ } else if (p_type_float && (PyLong_CheckExact(q_i) || PyBool_Check(q_i))) {
+ /* We care about float/int pairs and int/float pairs because
+ they arise naturally in several use cases such as price
+ times quantity, measurements with integer weights, or
+ data selected by a vector of bools. */
+ flt_p = PyFloat_AS_DOUBLE(p_i);
+ flt_q = PyLong_AsDouble(q_i);
+ if (flt_q == -1.0 && PyErr_Occurred()) {
+ PyErr_Clear();
+ goto finalize_flt_path;
+ }
+ } else if (q_type_float && (PyLong_CheckExact(p_i) || PyBool_Check(q_i))) {
+ flt_q = PyFloat_AS_DOUBLE(q_i);
+ flt_p = PyLong_AsDouble(p_i);
+ if (flt_p == -1.0 && PyErr_Occurred()) {
+ PyErr_Clear();
+ goto finalize_flt_path;
+ }
+ } else {
+ goto finalize_flt_path;
+ }
+ DoubleLength new_flt_total = dl_fma(flt_total, flt_p, flt_q);
+ if (isfinite(new_flt_total.hi)) {
+ flt_total = new_flt_total;
+ flt_total_in_use = true;
+ Py_CLEAR(p_i);
+ Py_CLEAR(q_i);
+ continue;
+ }
+ }
+
+ finalize_flt_path:
+ // We're finished, overflowed, have a non-float, or got a non-finite value
+ flt_path_enabled = false;
+ if (flt_total_in_use) {
+ term_i = PyFloat_FromDouble(dl_to_d(flt_total));
+ if (term_i == NULL) {
+ goto err_exit;
+ }
+ new_total = PyNumber_Add(total, term_i);
+ if (new_total == NULL) {
+ goto err_exit;
+ }
+ Py_SETREF(total, new_total);
+ new_total = NULL;
+ Py_CLEAR(term_i);
+ flt_total = dl_zero();
+ flt_total_in_use = false;
+ }
+ }
+
+ assert(!int_total_in_use);
+ assert(!flt_total_in_use);
+ if (finished) {
+ goto normal_exit;
+ }
+ term_i = PyNumber_Multiply(p_i, q_i);
+ if (term_i == NULL) {
+ goto err_exit;
+ }
+ new_total = PyNumber_Add(total, term_i);
+ if (new_total == NULL) {
+ goto err_exit;
+ }
+ Py_SETREF(total, new_total);
+ new_total = NULL;
+ Py_CLEAR(p_i);
+ Py_CLEAR(q_i);
+ Py_CLEAR(term_i);
+ }
+
+ normal_exit:
+ Py_DECREF(p_it);
+ Py_DECREF(q_it);
+ return total;
+
+ err_exit:
+ Py_DECREF(p_it);
+ Py_DECREF(q_it);
+ Py_DECREF(total);
+ Py_XDECREF(p_i);
+ Py_XDECREF(q_i);
+ Py_XDECREF(term_i);
+ Py_XDECREF(new_total);
+ return NULL;
+}
+
+
/* pow can't use math_2, but needs its own wrapper: the problem is
that an infinite result can arise either as a result of overflow
(in which case OverflowError should be raised) or as a result of
@@ -3933,6 +4257,7 @@ static PyMethodDef math_methods[] = {
{"sqrt", math_sqrt, METH_O, math_sqrt_doc},
{"tan", math_tan, METH_O, math_tan_doc},
{"tanh", math_tanh, METH_O, math_tanh_doc},
+ MATH_SUMPROD_METHODDEF
MATH_TRUNC_METHODDEF
MATH_PROD_METHODDEF
MATH_PERM_METHODDEF
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