Skip to content

bpo-38639: Optimize floor(), ceil() and trunc() for floats.#16991

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
serhiy-storchaka merged 3 commits into from
Nov 16, 2019
Merged

bpo-38639: Optimize floor(), ceil() and trunc() for floats. #16991

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
d80f7bd
bpo-38639: Optimize floor(), ceil() and trunc() for floats.
serhiy-storchaka Oct 30, 2019
265271a
Get rid of math_1_to_int.
serhiy-storchaka Oct 30, 2019
864845a
Add tests.
serhiy-storchaka Nov 7, 2019
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
61 changes: 40 additions & 21 deletions Lib/test/test_math.py
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -240,6 +240,13 @@ def result_check(expected, got, ulp_tol=5, abs_tol=0.0):
else:
return None

class FloatLike:
def __init__(self, value):
self.value = value

def __float__(self):
return self.value

class IntSubclass(int):
pass

Expand DownExpand Up@@ -397,22 +404,29 @@ def testAtan2(self):
def testCeil(self):
self.assertRaises(TypeError, math.ceil)
self.assertEqual(int, type(math.ceil(0.5)))
self.ftest('ceil(0.5)', math.ceil(0.5), 1)
self.ftest('ceil(1.0)', math.ceil(1.0), 1)
self.ftest('ceil(1.5)', math.ceil(1.5), 2)
self.ftest('ceil(-0.5)', math.ceil(-0.5), 0)
self.ftest('ceil(-1.0)', math.ceil(-1.0), -1)
self.ftest('ceil(-1.5)', math.ceil(-1.5), -1)
self.assertEqual(math.ceil(0.5), 1)
self.assertEqual(math.ceil(1.0), 1)
self.assertEqual(math.ceil(1.5), 2)
self.assertEqual(math.ceil(-0.5), 0)
self.assertEqual(math.ceil(-1.0), -1)
self.assertEqual(math.ceil(-1.5), -1)
self.assertEqual(math.ceil(0.0), 0)
self.assertEqual(math.ceil(-0.0), 0)
#self.assertEqual(math.ceil(INF), INF)
#self.assertEqual(math.ceil(NINF), NINF)
#self.assertTrue(math.isnan(math.ceil(NAN)))

class TestCeil:
def __ceil__(self):
return 42
class FloatCeil(float):
def __ceil__(self):
return 42
class TestNoCeil:
pass
self.ftest('ceil(TestCeil())', math.ceil(TestCeil()), 42)
self.assertEqual(math.ceil(TestCeil()), 42)
self.assertEqual(math.ceil(FloatCeil()), 42)
self.assertEqual(math.ceil(FloatLike(42.5)), 43)
self.assertRaises(TypeError, math.ceil, TestNoCeil())

t = TestNoCeil()
Expand DownExpand Up@@ -536,26 +550,27 @@ def testFactorialHugeInputs(self):
def testFloor(self):
self.assertRaises(TypeError, math.floor)
self.assertEqual(int, type(math.floor(0.5)))
self.ftest('floor(0.5)', math.floor(0.5), 0)
self.ftest('floor(1.0)', math.floor(1.0), 1)
self.ftest('floor(1.5)', math.floor(1.5), 1)
self.ftest('floor(-0.5)', math.floor(-0.5), -1)
self.ftest('floor(-1.0)', math.floor(-1.0), -1)
self.ftest('floor(-1.5)', math.floor(-1.5), -2)
# pow() relies on floor() to check for integers
# This fails on some platforms - so check it here
self.ftest('floor(1.23e167)', math.floor(1.23e167), 1.23e167)
self.ftest('floor(-1.23e167)', math.floor(-1.23e167), -1.23e167)
self.assertEqual(math.floor(0.5), 0)
self.assertEqual(math.floor(1.0), 1)
self.assertEqual(math.floor(1.5), 1)
self.assertEqual(math.floor(-0.5), -1)
self.assertEqual(math.floor(-1.0), -1)
self.assertEqual(math.floor(-1.5), -2)
#self.assertEqual(math.ceil(INF), INF)
#self.assertEqual(math.ceil(NINF), NINF)
#self.assertTrue(math.isnan(math.floor(NAN)))

class TestFloor:
def __floor__(self):
return 42
class FloatFloor(float):
def __floor__(self):
return 42
class TestNoFloor:
pass
self.ftest('floor(TestFloor())', math.floor(TestFloor()), 42)
self.assertEqual(math.floor(TestFloor()), 42)
self.assertEqual(math.floor(FloatFloor()), 42)
self.assertEqual(math.floor(FloatLike(41.9)), 41)
self.assertRaises(TypeError, math.floor, TestNoFloor())

t = TestNoFloor()
Expand DownExpand Up@@ -1448,17 +1463,21 @@ def test_trunc(self):
self.assertEqual(math.trunc(-0.999999), -0)
self.assertEqual(math.trunc(-100.999), -100)

class TestTrunc(object):
class TestTrunc:
def __trunc__(self):
return 23

class TestNoTrunc(object):
class FloatTrunc(float):
def __trunc__(self):
return 23
class TestNoTrunc:
pass

self.assertEqual(math.trunc(TestTrunc()), 23)
self.assertEqual(math.trunc(FloatTrunc()), 23)

self.assertRaises(TypeError, math.trunc)
self.assertRaises(TypeError, math.trunc, 1, 2)
self.assertRaises(TypeError, math.trunc, FloatLike(23.5))
self.assertRaises(TypeError, math.trunc, TestNoTrunc())

def testIsfinite(self):
Expand Down
2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Core and Builtins/2019-10-30-11-31-47.bpo-38639.9-vKtO.rst
View file
Open in desktop
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,2 @@
Optimized :func:`math.floor()`, :func:`math.ceil()` and :func:`math.trunc()`
for floats.
48 changes: 28 additions & 20 deletions Modules/mathmodule.c
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -1013,12 +1013,6 @@ math_1(PyObject *arg, double (*func) (double), int can_overflow)
return math_1_to_whatever(arg, func, PyFloat_FromDouble, can_overflow);
}

static PyObject *
math_1_to_int(PyObject *arg, double (*func) (double), int can_overflow)
{
return math_1_to_whatever(arg, func, PyLong_FromDouble, can_overflow);
}

static PyObject *
math_2(PyObject *const *args, Py_ssize_t nargs,
double (*func) (double, double), const char *funcname)
Expand DownExpand Up@@ -1112,17 +1106,22 @@ math_ceil(PyObject *module, PyObject *number)
/*[clinic end generated code: output=6c3b8a78bc201c67 input=2725352806399cab]*/
{
_Py_IDENTIFIER(__ceil__);
PyObject *method, *result;

method = _PyObject_LookupSpecial(number, &PyId___ceil__);
if (method == NULL){
if (!PyFloat_CheckExact(number)){
PyObject *method = _PyObject_LookupSpecial(number, &PyId___ceil__);
if (method != NULL){
PyObject *result = _PyObject_CallNoArg(method);
Py_DECREF(method);
return result;
}
if (PyErr_Occurred())
return NULL;
return math_1_to_int(number, ceil, 0);
}
result = _PyObject_CallNoArg(method);
Py_DECREF(method);
return result;
double x = PyFloat_AsDouble(number);
if (x == -1.0 && PyErr_Occurred())
return NULL;

return PyLong_FromDouble(ceil(x));
}

FUNC2(copysign, copysign,
Expand DownExpand Up@@ -1170,17 +1169,22 @@ math_floor(PyObject *module, PyObject *number)
/*[clinic end generated code: output=c6a65c4884884b8a input=63af6b5d7ebcc3d6]*/
{
_Py_IDENTIFIER(__floor__);
PyObject *method, *result;

method = _PyObject_LookupSpecial(number, &PyId___floor__);
if (method == NULL){
if (!PyFloat_CheckExact(number)){
PyObject *method = _PyObject_LookupSpecial(number, &PyId___floor__);
if (method != NULL){
PyObject *result = _PyObject_CallNoArg(method);
Py_DECREF(method);
return result;
}
if (PyErr_Occurred())
return NULL;
return math_1_to_int(number, floor, 0);
}
result = _PyObject_CallNoArg(method);
Py_DECREF(method);
return result;
double x = PyFloat_AsDouble(number);
if (x == -1.0 && PyErr_Occurred())
return NULL;

return PyLong_FromDouble(floor(x));
}

FUNC1A(gamma, m_tgamma,
Expand DownExpand Up@@ -2061,6 +2065,10 @@ math_trunc(PyObject *module, PyObject *x)
_Py_IDENTIFIER(__trunc__);
PyObject *trunc, *result;

if (PyFloat_CheckExact(x)){
return PyFloat_Type.tp_as_number->nb_int(x);
}

if (Py_TYPE(x)->tp_dict == NULL){
if (PyType_Ready(Py_TYPE(x)) < 0)
return NULL;
Expand Down