diff -r 46e2755b022c Doc/c-api/arg.rst
--- a/Doc/c-api/arg.rst	Fri Nov 25 11:59:52 2016 +0100
+++ b/Doc/c-api/arg.rst	Fri Nov 25 13:29:08 2016 +0100
@@ -275,6 +275,11 @@ Numbers
 ``n`` (:class:`int`) [Py_ssize_t]
    Convert a Python integer to a C :c:type:`Py_ssize_t`.
 
+``m`` (:class:`int`) [intmax_t]
+   Convert a Python integer to a C :c:type:`intmax_t`.
+
+   .. versionadded:: 3.7
+
 ``c`` (:class:`bytes` or :class:`bytearray` of length 1) [char]
    Convert a Python byte, represented as a :class:`bytes` or
    :class:`bytearray` object of length 1, to a C :c:type:`char`.
@@ -600,6 +605,9 @@ Building values
    ``n`` (:class:`int`) [Py_ssize_t]
       Convert a C :c:type:`Py_ssize_t` to a Python integer.
 
+   ``m`` (:class:`int`) [intmax_t]
+      Convert a C :c:type:`intmax_t` to a Python integer.
+
    ``c`` (:class:`bytes` of length 1) [char]
       Convert a C :c:type:`int` representing a byte to a Python :class:`bytes` object of
       length 1.
@@ -653,6 +661,11 @@ Building values
    If there is an error in the format string, the :exc:`SystemError` exception is
    set and *NULL* returned.
 
+   .. versionchanged:: 3.7
+
+      Added ``m`` format for ``intmax_t``.
+
+
 .. c:function:: PyObject* Py_VaBuildValue(const char *format, va_list vargs)
 
    Identical to :c:func:`Py_BuildValue`, except that it accepts a va_list
diff -r 46e2755b022c Include/longobject.h
--- a/Include/longobject.h	Fri Nov 25 11:59:52 2016 +0100
+++ b/Include/longobject.h	Fri Nov 25 13:29:08 2016 +0100
@@ -17,14 +17,19 @@ PyAPI_DATA(PyTypeObject) PyLong_Type;
 
 PyAPI_FUNC(PyObject *) PyLong_FromLong(long);
 PyAPI_FUNC(PyObject *) PyLong_FromUnsignedLong(unsigned long);
+PyAPI_FUNC(PyObject *) PyLong_FromIntMax(intmax_t);
+PyAPI_FUNC(PyObject *) PyLong_FromUIntMax(uintmax_t);
 PyAPI_FUNC(PyObject *) PyLong_FromSize_t(size_t);
 PyAPI_FUNC(PyObject *) PyLong_FromSsize_t(Py_ssize_t);
 PyAPI_FUNC(PyObject *) PyLong_FromDouble(double);
 PyAPI_FUNC(long) PyLong_AsLong(PyObject *);
 PyAPI_FUNC(long) PyLong_AsLongAndOverflow(PyObject *, int *);
+PyAPI_FUNC(intmax_t) PyLong_AsIntMax(PyObject *);
+PyAPI_FUNC(intmax_t) PyLong_AsIntMaxAndOverflow(PyObject *, int *);
 PyAPI_FUNC(Py_ssize_t) PyLong_AsSsize_t(PyObject *);
 PyAPI_FUNC(size_t) PyLong_AsSize_t(PyObject *);
 PyAPI_FUNC(unsigned long) PyLong_AsUnsignedLong(PyObject *);
+PyAPI_FUNC(uintmax_t) PyLong_AsUIntMax(PyObject *);
 PyAPI_FUNC(unsigned long) PyLong_AsUnsignedLongMask(PyObject *);
 #ifndef Py_LIMITED_API
 PyAPI_FUNC(int) _PyLong_AsInt(PyObject *);
diff -r 46e2755b022c Lib/test/test_getargs2.py
--- a/Lib/test/test_getargs2.py	Fri Nov 25 11:59:52 2016 +0100
+++ b/Lib/test/test_getargs2.py	Fri Nov 25 13:29:08 2016 +0100
@@ -3,7 +3,7 @@ import math
 import sys
 from test import support
 # Skip this test if the _testcapi module isn't available.
-support.import_module('_testcapi')
+_testcapi = support.import_module('_testcapi')
 from _testcapi import getargs_keywords, getargs_keyword_only
 
 # > How about the following counterproposal. This also changes some of
@@ -128,222 +128,120 @@ class DictSubclass(dict):
     pass
 
 
-class Unsigned_TestCase(unittest.TestCase):
-    def test_b(self):
-        from _testcapi import getargs_b
-        # b returns 'unsigned char', and does range checking (0 ... UCHAR_MAX)
-        self.assertRaises(TypeError, getargs_b, 3.14)
-        self.assertEqual(99, getargs_b(Int()))
-        self.assertEqual(0, getargs_b(IntSubclass()))
-        self.assertRaises(TypeError, getargs_b, BadInt())
-        with self.assertWarns(DeprecationWarning):
-            self.assertEqual(1, getargs_b(BadInt2()))
-        self.assertEqual(0, getargs_b(BadInt3()))
+class UnsignedLong_TestCase:
+    getargs = None
+    MIN = 0
+    MAX = 1
+    SUPPORT_INT = False
 
-        self.assertRaises(OverflowError, getargs_b, -1)
-        self.assertEqual(0, getargs_b(0))
-        self.assertEqual(UCHAR_MAX, getargs_b(UCHAR_MAX))
-        self.assertRaises(OverflowError, getargs_b, UCHAR_MAX + 1)
+    def test_basic(self):
+        self.assertEqual(42, self.getargs(42))
+        self.assertEqual(self.MIN, self.getargs(self.MIN))
+        self.assertEqual(self.MAX, self.getargs(self.MAX))
 
-        self.assertEqual(42, getargs_b(42))
-        self.assertRaises(OverflowError, getargs_b, VERY_LARGE)
+    def test_types(self):
+        self.assertRaises(TypeError, self.getargs, 3.14)
+        self.assertRaises(TypeError, self.getargs, "Hello")
+        self.assertEqual(0, self.getargs(IntSubclass()))
 
-    def test_B(self):
-        from _testcapi import getargs_B
-        # B returns 'unsigned char', no range checking
-        self.assertRaises(TypeError, getargs_B, 3.14)
-        self.assertEqual(99, getargs_B(Int()))
-        self.assertEqual(0, getargs_B(IntSubclass()))
-        self.assertRaises(TypeError, getargs_B, BadInt())
-        with self.assertWarns(DeprecationWarning):
-            self.assertEqual(1, getargs_B(BadInt2()))
-        self.assertEqual(0, getargs_B(BadInt3()))
+    def test_int(self):
+        if self.SUPPORT_INT:
+            self.assertEqual(99, self.getargs(Int()))
+            self.assertRaises(TypeError, self.getargs, BadInt())
+            with self.assertWarns(DeprecationWarning):
+                self.assertEqual(1, self.getargs(BadInt2()))
+        else:
+            self.assertRaises(TypeError, self.getargs, Int())
+            self.assertRaises(TypeError, self.getargs, BadInt())
+            self.assertRaises(TypeError, self.getargs, BadInt2())
 
-        self.assertEqual(UCHAR_MAX, getargs_B(-1))
-        self.assertEqual(0, getargs_B(0))
-        self.assertEqual(UCHAR_MAX, getargs_B(UCHAR_MAX))
-        self.assertEqual(0, getargs_B(UCHAR_MAX+1))
+        self.assertEqual(0, self.getargs(BadInt3()))
 
-        self.assertEqual(42, getargs_B(42))
-        self.assertEqual(UCHAR_MAX & VERY_LARGE, getargs_B(VERY_LARGE))
+    def test_overflow(self):
+        for value in (self.MIN - 1, self.MAX + 1):
+            self.assertEqual(value & self.MAX, self.getargs(value))
+        self.assertEqual(VERY_LARGE & self.MAX, self.getargs(VERY_LARGE))
 
-    def test_H(self):
-        from _testcapi import getargs_H
-        # H returns 'unsigned short', no range checking
-        self.assertRaises(TypeError, getargs_H, 3.14)
-        self.assertEqual(99, getargs_H(Int()))
-        self.assertEqual(0, getargs_H(IntSubclass()))
-        self.assertRaises(TypeError, getargs_H, BadInt())
-        with self.assertWarns(DeprecationWarning):
-            self.assertEqual(1, getargs_H(BadInt2()))
-        self.assertEqual(0, getargs_H(BadInt3()))
 
-        self.assertEqual(USHRT_MAX, getargs_H(-1))
-        self.assertEqual(0, getargs_H(0))
-        self.assertEqual(USHRT_MAX, getargs_H(USHRT_MAX))
-        self.assertEqual(0, getargs_H(USHRT_MAX+1))
+class SignedLong_TestCase(UnsignedLong_TestCase):
+    MIN = -1
+    SUPPORT_INT = True
 
-        self.assertEqual(42, getargs_H(42))
+    def test_overflow(self):
+        self.assertRaises(OverflowError, self.getargs, self.MIN - 1)
+        self.assertRaises(OverflowError, self.getargs, self.MAX + 1)
+        self.assertRaises(OverflowError, self.getargs, VERY_LARGE)
 
-        self.assertEqual(VERY_LARGE & USHRT_MAX, getargs_H(VERY_LARGE))
 
-    def test_I(self):
-        from _testcapi import getargs_I
-        # I returns 'unsigned int', no range checking
-        self.assertRaises(TypeError, getargs_I, 3.14)
-        self.assertEqual(99, getargs_I(Int()))
-        self.assertEqual(0, getargs_I(IntSubclass()))
-        self.assertRaises(TypeError, getargs_I, BadInt())
-        with self.assertWarns(DeprecationWarning):
-            self.assertEqual(1, getargs_I(BadInt2()))
-        self.assertEqual(0, getargs_I(BadInt3()))
+class Long_b(SignedLong_TestCase, unittest.TestCase):
+    getargs = _testcapi.getargs_b
+    MIN = 0
+    MAX = UCHAR_MAX
 
-        self.assertEqual(UINT_MAX, getargs_I(-1))
-        self.assertEqual(0, getargs_I(0))
-        self.assertEqual(UINT_MAX, getargs_I(UINT_MAX))
-        self.assertEqual(0, getargs_I(UINT_MAX+1))
 
-        self.assertEqual(42, getargs_I(42))
+class Long_h(SignedLong_TestCase, unittest.TestCase):
+    getargs = _testcapi.getargs_h
+    MIN = SHRT_MIN
+    MAX = SHRT_MAX
 
-        self.assertEqual(VERY_LARGE & UINT_MAX, getargs_I(VERY_LARGE))
 
-    def test_k(self):
-        from _testcapi import getargs_k
-        # k returns 'unsigned long', no range checking
-        # it does not accept float, or instances with __int__
-        self.assertRaises(TypeError, getargs_k, 3.14)
-        self.assertRaises(TypeError, getargs_k, Int())
-        self.assertEqual(0, getargs_k(IntSubclass()))
-        self.assertRaises(TypeError, getargs_k, BadInt())
-        self.assertRaises(TypeError, getargs_k, BadInt2())
-        self.assertEqual(0, getargs_k(BadInt3()))
+class Long_i(SignedLong_TestCase, unittest.TestCase):
+    getargs = _testcapi.getargs_i
+    MIN = INT_MIN
+    MAX = INT_MAX
 
-        self.assertEqual(ULONG_MAX, getargs_k(-1))
-        self.assertEqual(0, getargs_k(0))
-        self.assertEqual(ULONG_MAX, getargs_k(ULONG_MAX))
-        self.assertEqual(0, getargs_k(ULONG_MAX+1))
 
-        self.assertEqual(42, getargs_k(42))
+class Long_l(SignedLong_TestCase, unittest.TestCase):
+    getargs = _testcapi.getargs_l
+    MIN = LONG_MIN
+    MAX = LONG_MAX
 
-        self.assertEqual(VERY_LARGE & ULONG_MAX, getargs_k(VERY_LARGE))
 
-class Signed_TestCase(unittest.TestCase):
-    def test_h(self):
-        from _testcapi import getargs_h
-        # h returns 'short', and does range checking (SHRT_MIN ... SHRT_MAX)
-        self.assertRaises(TypeError, getargs_h, 3.14)
-        self.assertEqual(99, getargs_h(Int()))
-        self.assertEqual(0, getargs_h(IntSubclass()))
-        self.assertRaises(TypeError, getargs_h, BadInt())
-        with self.assertWarns(DeprecationWarning):
-            self.assertEqual(1, getargs_h(BadInt2()))
-        self.assertEqual(0, getargs_h(BadInt3()))
+class LongLong_L(SignedLong_TestCase, unittest.TestCase):
+    getargs = _testcapi.getargs_L
+    MIN = LLONG_MIN
+    MAX = LLONG_MAX
 
-        self.assertRaises(OverflowError, getargs_h, SHRT_MIN-1)
-        self.assertEqual(SHRT_MIN, getargs_h(SHRT_MIN))
-        self.assertEqual(SHRT_MAX, getargs_h(SHRT_MAX))
-        self.assertRaises(OverflowError, getargs_h, SHRT_MAX+1)
 
-        self.assertEqual(42, getargs_h(42))
-        self.assertRaises(OverflowError, getargs_h, VERY_LARGE)
+class Long_n(SignedLong_TestCase, unittest.TestCase):
+    getargs = _testcapi.getargs_n
+    MIN = PY_SSIZE_T_MIN
+    MAX = PY_SSIZE_T_MAX
+    SUPPORT_INT = False
 
-    def test_i(self):
-        from _testcapi import getargs_i
-        # i returns 'int', and does range checking (INT_MIN ... INT_MAX)
-        self.assertRaises(TypeError, getargs_i, 3.14)
-        self.assertEqual(99, getargs_i(Int()))
-        self.assertEqual(0, getargs_i(IntSubclass()))
-        self.assertRaises(TypeError, getargs_i, BadInt())
-        with self.assertWarns(DeprecationWarning):
-            self.assertEqual(1, getargs_i(BadInt2()))
-        self.assertEqual(0, getargs_i(BadInt3()))
 
-        self.assertRaises(OverflowError, getargs_i, INT_MIN-1)
-        self.assertEqual(INT_MIN, getargs_i(INT_MIN))
-        self.assertEqual(INT_MAX, getargs_i(INT_MAX))
-        self.assertRaises(OverflowError, getargs_i, INT_MAX+1)
+class Long_B(UnsignedLong_TestCase, unittest.TestCase):
+    getargs = _testcapi.getargs_B
+    MAX = UCHAR_MAX
+    SUPPORT_INT = True
 
-        self.assertEqual(42, getargs_i(42))
-        self.assertRaises(OverflowError, getargs_i, VERY_LARGE)
 
-    def test_l(self):
-        from _testcapi import getargs_l
-        # l returns 'long', and does range checking (LONG_MIN ... LONG_MAX)
-        self.assertRaises(TypeError, getargs_l, 3.14)
-        self.assertEqual(99, getargs_l(Int()))
-        self.assertEqual(0, getargs_l(IntSubclass()))
-        self.assertRaises(TypeError, getargs_l, BadInt())
-        with self.assertWarns(DeprecationWarning):
-            self.assertEqual(1, getargs_l(BadInt2()))
-        self.assertEqual(0, getargs_l(BadInt3()))
+class Long_H(UnsignedLong_TestCase, unittest.TestCase):
+    getargs = _testcapi.getargs_H
+    MAX = USHRT_MAX
+    SUPPORT_INT = True
 
-        self.assertRaises(OverflowError, getargs_l, LONG_MIN-1)
-        self.assertEqual(LONG_MIN, getargs_l(LONG_MIN))
-        self.assertEqual(LONG_MAX, getargs_l(LONG_MAX))
-        self.assertRaises(OverflowError, getargs_l, LONG_MAX+1)
 
-        self.assertEqual(42, getargs_l(42))
-        self.assertRaises(OverflowError, getargs_l, VERY_LARGE)
+class Long_I(UnsignedLong_TestCase, unittest.TestCase):
+    getargs = _testcapi.getargs_I
+    MAX = UINT_MAX
+    SUPPORT_INT = True
 
-    def test_n(self):
-        from _testcapi import getargs_n
-        # n returns 'Py_ssize_t', and does range checking
-        # (PY_SSIZE_T_MIN ... PY_SSIZE_T_MAX)
-        self.assertRaises(TypeError, getargs_n, 3.14)
-        self.assertRaises(TypeError, getargs_n, Int())
-        self.assertEqual(0, getargs_n(IntSubclass()))
-        self.assertRaises(TypeError, getargs_n, BadInt())
-        self.assertRaises(TypeError, getargs_n, BadInt2())
-        self.assertEqual(0, getargs_n(BadInt3()))
 
-        self.assertRaises(OverflowError, getargs_n, PY_SSIZE_T_MIN-1)
-        self.assertEqual(PY_SSIZE_T_MIN, getargs_n(PY_SSIZE_T_MIN))
-        self.assertEqual(PY_SSIZE_T_MAX, getargs_n(PY_SSIZE_T_MAX))
-        self.assertRaises(OverflowError, getargs_n, PY_SSIZE_T_MAX+1)
+class Long_k(UnsignedLong_TestCase, unittest.TestCase):
+    getargs = _testcapi.getargs_k
+    MAX = ULONG_MAX
 
-        self.assertEqual(42, getargs_n(42))
-        self.assertRaises(OverflowError, getargs_n, VERY_LARGE)
 
+class LongLong_K(UnsignedLong_TestCase, unittest.TestCase):
+    getargs = _testcapi.getargs_K
+    MAX = ULLONG_MAX
 
-class LongLong_TestCase(unittest.TestCase):
-    def test_L(self):
-        from _testcapi import getargs_L
-        # L returns 'long long', and does range checking (LLONG_MIN
-        # ... LLONG_MAX)
-        self.assertRaises(TypeError, getargs_L, 3.14)
-        self.assertRaises(TypeError, getargs_L, "Hello")
-        self.assertEqual(99, getargs_L(Int()))
-        self.assertEqual(0, getargs_L(IntSubclass()))
-        self.assertRaises(TypeError, getargs_L, BadInt())
-        with self.assertWarns(DeprecationWarning):
-            self.assertEqual(1, getargs_L(BadInt2()))
-        self.assertEqual(0, getargs_L(BadInt3()))
 
-        self.assertRaises(OverflowError, getargs_L, LLONG_MIN-1)
-        self.assertEqual(LLONG_MIN, getargs_L(LLONG_MIN))
-        self.assertEqual(LLONG_MAX, getargs_L(LLONG_MAX))
-        self.assertRaises(OverflowError, getargs_L, LLONG_MAX+1)
-
-        self.assertEqual(42, getargs_L(42))
-        self.assertRaises(OverflowError, getargs_L, VERY_LARGE)
-
-    def test_K(self):
-        from _testcapi import getargs_K
-        # K return 'unsigned long long', no range checking
-        self.assertRaises(TypeError, getargs_K, 3.14)
-        self.assertRaises(TypeError, getargs_K, Int())
-        self.assertEqual(0, getargs_K(IntSubclass()))
-        self.assertRaises(TypeError, getargs_K, BadInt())
-        self.assertRaises(TypeError, getargs_K, BadInt2())
-        self.assertEqual(0, getargs_K(BadInt3()))
-
-        self.assertEqual(ULLONG_MAX, getargs_K(ULLONG_MAX))
-        self.assertEqual(0, getargs_K(0))
-        self.assertEqual(0, getargs_K(ULLONG_MAX+1))
-
-        self.assertEqual(42, getargs_K(42))
-
-        self.assertEqual(VERY_LARGE & ULLONG_MAX, getargs_K(VERY_LARGE))
+class Long_IntMax_m(SignedLong_TestCase, unittest.TestCase):
+    getargs = _testcapi.getargs_m
+    MIN = _testcapi.INTMAX_MIN
+    MAX = _testcapi.INTMAX_MAX
 
 
 class Float_TestCase(unittest.TestCase):
diff -r 46e2755b022c Modules/_lzmamodule.c
--- a/Modules/_lzmamodule.c	Fri Nov 25 11:59:52 2016 +0100
+++ b/Modules/_lzmamodule.c	Fri Nov 25 13:29:08 2016 +0100
@@ -1442,9 +1442,9 @@ static PyModuleDef _lzmamodule = {
 /* Some of our constants are more than 32 bits wide, so PyModule_AddIntConstant
    would not work correctly on platforms with 32-bit longs. */
 static int
-module_add_int_constant(PyObject *m, const char *name, long long value)
+module_add_int_constant(PyObject *m, const char *name, intmax_t value)
 {
-    PyObject *o = PyLong_FromLongLong(value);
+    PyObject *o = PyLong_FromIntMax(value);
     if (o == NULL)
         return -1;
     if (PyModule_AddObject(m, name, o) == 0)
diff -r 46e2755b022c Modules/_testcapimodule.c
--- a/Modules/_testcapimodule.c	Fri Nov 25 11:59:52 2016 +0100
+++ b/Modules/_testcapimodule.c	Fri Nov 25 13:29:08 2016 +0100
@@ -61,6 +61,7 @@ test_config(PyObject *self)
     CHECK_SIZEOF(SIZEOF_VOID_P, void*);
     CHECK_SIZEOF(SIZEOF_TIME_T, time_t);
     CHECK_SIZEOF(SIZEOF_LONG_LONG, long long);
+    CHECK_SIZEOF(SIZEOF_INTMAX_T, intmax_t);
 
 #undef CHECK_SIZEOF
 
@@ -392,6 +393,7 @@ raise_test_long_error(const char* msg)
 
 #define TESTNAME        test_long_api_inner
 #define TYPENAME        long
+#define UTYPENAME       unsigned long
 #define F_S_TO_PY       PyLong_FromLong
 #define F_PY_TO_S       PyLong_AsLong
 #define F_U_TO_PY       PyLong_FromUnsignedLong
@@ -407,11 +409,46 @@ test_long_api(PyObject* self)
 
 #undef TESTNAME
 #undef TYPENAME
+#undef UTYPENAME
 #undef F_S_TO_PY
 #undef F_PY_TO_S
 #undef F_U_TO_PY
 #undef F_PY_TO_U
 
+/* intmax_t */
+
+static PyObject *
+raise_test_long_intmax_error(const char* msg)
+{
+    return raiseTestError("test_long_intmax_api", msg);
+}
+
+#define TESTNAME        test_long_intmax_api_inner
+#define TYPENAME        intmax_t
+#define UTYPENAME       uintmax_t
+#define F_S_TO_PY       PyLong_FromIntMax
+#define F_PY_TO_S       PyLong_AsIntMax
+#define F_U_TO_PY       PyLong_FromUIntMax
+#define F_PY_TO_U       PyLong_AsUIntMax
+
+#include "testcapi_long.h"
+
+static PyObject *
+test_long_intmax_api(PyObject* self, PyObject *args)
+{
+    return TESTNAME(raise_test_long_intmax_error);
+}
+
+#undef TESTNAME
+#undef TYPENAME
+#undef UTYPENAME
+#undef F_S_TO_PY
+#undef F_PY_TO_S
+#undef F_U_TO_PY
+#undef F_PY_TO_U
+
+/* long long */
+
 static PyObject *
 raise_test_longlong_error(const char* msg)
 {
@@ -420,6 +457,7 @@ raise_test_longlong_error(const char* ms
 
 #define TESTNAME        test_longlong_api_inner
 #define TYPENAME        long long
+#define UTYPENAME       unsigned long long
 #define F_S_TO_PY       PyLong_FromLongLong
 #define F_PY_TO_S       PyLong_AsLongLong
 #define F_U_TO_PY       PyLong_FromUnsignedLongLong
@@ -435,6 +473,7 @@ test_longlong_api(PyObject* self, PyObje
 
 #undef TESTNAME
 #undef TYPENAME
+#undef UTYPENAME
 #undef F_S_TO_PY
 #undef F_PY_TO_S
 #undef F_U_TO_PY
@@ -1160,6 +1199,15 @@ getargs_K(PyObject *self, PyObject *args
     return PyLong_FromUnsignedLongLong(value);
 }
 
+static PyObject *
+getargs_m(PyObject *self, PyObject *args)
+{
+    intmax_t value;
+    if (!PyArg_ParseTuple(args, "m", &value))
+        return NULL;
+    return PyLong_FromIntMax(value);
+}
+
 /* This function not only tests the 'k' getargs code, but also the
    PyLong_AsUnsignedLongMask() and PyLong_AsUnsignedLongMask() functions. */
 static PyObject *
@@ -4018,6 +4066,7 @@ static PyMethodDef TestMethods[] = {
     {"dict_getitem_knownhash",  dict_getitem_knownhash,          METH_VARARGS},
     {"test_lazy_hash_inheritance",      (PyCFunction)test_lazy_hash_inheritance,METH_NOARGS},
     {"test_long_api",           (PyCFunction)test_long_api,      METH_NOARGS},
+    {"test_long_intmax_api",           (PyCFunction)test_long_intmax_api,      METH_NOARGS},
     {"test_xincref_doesnt_leak",(PyCFunction)test_xincref_doesnt_leak,      METH_NOARGS},
     {"test_incref_doesnt_leak", (PyCFunction)test_incref_doesnt_leak,      METH_NOARGS},
     {"test_xdecref_doesnt_leak",(PyCFunction)test_xdecref_doesnt_leak,      METH_NOARGS},
@@ -4066,6 +4115,7 @@ static PyMethodDef TestMethods[] = {
     {"getargs_p",               getargs_p,                       METH_VARARGS},
     {"getargs_L",               getargs_L,                       METH_VARARGS},
     {"getargs_K",               getargs_K,                       METH_VARARGS},
+    {"getargs_m",               getargs_m,                       METH_VARARGS},
     {"test_longlong_api",       test_longlong_api,               METH_NOARGS},
     {"test_long_long_and_overflow",
         (PyCFunction)test_long_long_and_overflow, METH_NOARGS},
@@ -4603,7 +4653,10 @@ PyInit__testcapi(void)
     PyModule_AddObject(m, "UINT_MAX",  PyLong_FromUnsignedLong(UINT_MAX));
     PyModule_AddObject(m, "LONG_MAX", PyLong_FromLong(LONG_MAX));
     PyModule_AddObject(m, "LONG_MIN", PyLong_FromLong(LONG_MIN));
+    PyModule_AddObject(m, "INTMAX_MAX", PyLong_FromIntMax(INTMAX_MAX));
+    PyModule_AddObject(m, "INTMAX_MIN", PyLong_FromIntMax(INTMAX_MIN));
     PyModule_AddObject(m, "ULONG_MAX", PyLong_FromUnsignedLong(ULONG_MAX));
+    PyModule_AddObject(m, "UINTMAX_MAX", PyLong_FromUIntMax(UINTMAX_MAX));
     PyModule_AddObject(m, "FLT_MAX", PyFloat_FromDouble(FLT_MAX));
     PyModule_AddObject(m, "FLT_MIN", PyFloat_FromDouble(FLT_MIN));
     PyModule_AddObject(m, "DBL_MAX", PyFloat_FromDouble(DBL_MAX));
diff -r 46e2755b022c Modules/_tkinter.c
--- a/Modules/_tkinter.c	Fri Nov 25 11:59:52 2016 +0100
+++ b/Modules/_tkinter.c	Fri Nov 25 13:29:08 2016 +0100
@@ -1182,8 +1182,9 @@ fromWideIntObj(PyObject* tkapp, Tcl_Obj 
 {
         Tcl_WideInt wideValue;
         if (Tcl_GetWideIntFromObj(Tkapp_Interp(tkapp), value, &wideValue) == TCL_OK) {
-            if (sizeof(wideValue) <= SIZEOF_LONG_LONG)
-                return PyLong_FromLongLong(wideValue);
+            if (sizeof(wideValue) <= SIZEOF_INTMAX_T) {
+                return PyLong_FromIntMax(wideValue);
+            }
             return _PyLong_FromByteArray((unsigned char *)(void *)&wideValue,
                                          sizeof(wideValue),
                                          PY_LITTLE_ENDIAN,
diff -r 46e2755b022c Modules/clinic/posixmodule.c.h
--- a/Modules/clinic/posixmodule.c.h	Fri Nov 25 11:59:52 2016 +0100
+++ b/Modules/clinic/posixmodule.c.h	Fri Nov 25 13:29:08 2016 +0100
@@ -3533,7 +3533,7 @@ os_lseek(PyObject *module, PyObject *arg
     if ((_return_value == -1) && PyErr_Occurred()) {
         goto exit;
     }
-    return_value = PyLong_FromPy_off_t(_return_value);
+    return_value = PyLong_FromIntMax(_return_value);
 
 exit:
     return return_value;
@@ -6352,4 +6352,4 @@ exit:
 #ifndef OS_GETRANDOM_METHODDEF
     #define OS_GETRANDOM_METHODDEF
 #endif /* !defined(OS_GETRANDOM_METHODDEF) */
-/*[clinic end generated code: output=61abf6df195aa5f1 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=949da9b5a6eceeab input=a9049054013a1b77]*/
diff -r 46e2755b022c Modules/mmapmodule.c
--- a/Modules/mmapmodule.c	Fri Nov 25 11:59:52 2016 +0100
+++ b/Modules/mmapmodule.c	Fri Nov 25 13:29:08 2016 +0100
@@ -433,7 +433,7 @@ mmap_size_method(mmap_object *self,
 #ifdef MS_WINDOWS
     if (self->file_handle != INVALID_HANDLE_VALUE) {
         DWORD low,high;
-        long long size;
+        intmax_t size;
         low = GetFileSize(self->file_handle, &high);
         if (low == INVALID_FILE_SIZE) {
             /* It might be that the function appears to have failed,
@@ -444,8 +444,8 @@ mmap_size_method(mmap_object *self,
         }
         if (!high && low < LONG_MAX)
             return PyLong_FromLong((long)low);
-        size = (((long long)high)<<32) + low;
-        return PyLong_FromLongLong(size);
+        size = (((intmax_t)high)<<32) + low;
+        return PyLong_FromIntMax(size);
     } else {
         return PyLong_FromSsize_t(self->size);
     }
@@ -456,11 +456,7 @@ mmap_size_method(mmap_object *self,
         struct _Py_stat_struct status;
         if (_Py_fstat(self->fd, &status) == -1)
             return NULL;
-#ifdef HAVE_LARGEFILE_SUPPORT
-        return PyLong_FromLongLong(status.st_size);
-#else
-        return PyLong_FromLong(status.st_size);
-#endif
+        return PyLong_FromIntMax(status.st_size);
     }
 #endif /* UNIX */
 }
diff -r 46e2755b022c Modules/posixmodule.c
--- a/Modules/posixmodule.c	Fri Nov 25 11:59:52 2016 +0100
+++ b/Modules/posixmodule.c	Fri Nov 25 13:29:08 2016 +0100
@@ -649,7 +649,7 @@ fail:
 #endif /* MS_WINDOWS */
 
 
-#define _PyLong_FromDev PyLong_FromLongLong
+#define _PyLong_FromDev PyLong_FromIntMax
 
 
 #if defined(HAVE_MKNOD) && defined(HAVE_MAKEDEV)
@@ -1168,16 +1168,6 @@ Py_off_t_converter(PyObject *arg, void *
     return 1;
 }
 
-static PyObject *
-PyLong_FromPy_off_t(Py_off_t offset)
-{
-#ifdef HAVE_LARGEFILE_SUPPORT
-    return PyLong_FromLongLong(offset);
-#else
-    return PyLong_FromLong(offset);
-#endif
-}
-
 #ifdef MS_WINDOWS
 
 static int
@@ -1929,12 +1919,7 @@ static PyObject*
         return NULL;
 
     PyStructSequence_SET_ITEM(v, 0, PyLong_FromLong((long)st->st_mode));
-#ifdef HAVE_LARGEFILE_SUPPORT
-    PyStructSequence_SET_ITEM(v, 1,
-                              PyLong_FromLongLong((long long)st->st_ino));
-#else
-    PyStructSequence_SET_ITEM(v, 1, PyLong_FromLong((long)st->st_ino));
-#endif
+    PyStructSequence_SET_ITEM(v, 1, PyLong_FromIntMax(st->st_ino));
 #ifdef MS_WINDOWS
     PyStructSequence_SET_ITEM(v, 2, PyLong_FromUnsignedLong(st->st_dev));
 #else
@@ -1948,12 +1933,7 @@ static PyObject*
     PyStructSequence_SET_ITEM(v, 4, _PyLong_FromUid(st->st_uid));
     PyStructSequence_SET_ITEM(v, 5, _PyLong_FromGid(st->st_gid));
 #endif
-#ifdef HAVE_LARGEFILE_SUPPORT
-    PyStructSequence_SET_ITEM(v, 6,
-                              PyLong_FromLongLong((long long)st->st_size));
-#else
-    PyStructSequence_SET_ITEM(v, 6, PyLong_FromLong(st->st_size));
-#endif
+    PyStructSequence_SET_ITEM(v, 6, PyLong_FromIntMax(st->st_size));
 
 #if defined(HAVE_STAT_TV_NSEC)
     ansec = st->st_atim.tv_nsec;
@@ -2358,7 +2338,7 @@ class Py_off_t_converter(CConverter):
 
 class Py_off_t_return_converter(long_return_converter):
     type = 'Py_off_t'
-    conversion_fn = 'PyLong_FromPy_off_t'
+    conversion_fn = 'PyLong_FromIntMax'
 
 class path_confname_converter(CConverter):
     type="int"
@@ -2376,7 +2356,7 @@ class sched_param_converter(CConverter):
     impl_by_reference = True;
 
 [python start generated code]*/
-/*[python end generated code: output=da39a3ee5e6b4b0d input=418fce0e01144461]*/
+/*[python end generated code: output=da39a3ee5e6b4b0d input=6810f54d2201a416]*/
 
 /*[clinic input]
 
@@ -9156,18 +9136,12 @@ static PyObject*
 #else
     PyStructSequence_SET_ITEM(v, 0, PyLong_FromLong((long) st.f_bsize));
     PyStructSequence_SET_ITEM(v, 1, PyLong_FromLong((long) st.f_frsize));
-    PyStructSequence_SET_ITEM(v, 2,
-                              PyLong_FromLongLong((long long) st.f_blocks));
-    PyStructSequence_SET_ITEM(v, 3,
-                              PyLong_FromLongLong((long long) st.f_bfree));
-    PyStructSequence_SET_ITEM(v, 4,
-                              PyLong_FromLongLong((long long) st.f_bavail));
-    PyStructSequence_SET_ITEM(v, 5,
-                              PyLong_FromLongLong((long long) st.f_files));
-    PyStructSequence_SET_ITEM(v, 6,
-                              PyLong_FromLongLong((long long) st.f_ffree));
-    PyStructSequence_SET_ITEM(v, 7,
-                              PyLong_FromLongLong((long long) st.f_favail));
+    PyStructSequence_SET_ITEM(v, 2, PyLong_FromIntMax(st.f_blocks));
+    PyStructSequence_SET_ITEM(v, 3, PyLong_FromIntMax(st.f_bfree));
+    PyStructSequence_SET_ITEM(v, 4, PyLong_FromIntMax(st.f_bavail));
+    PyStructSequence_SET_ITEM(v, 5, PyLong_FromIntMax(st.f_files));
+    PyStructSequence_SET_ITEM(v, 6, PyLong_FromIntMax(st.f_ffree));
+    PyStructSequence_SET_ITEM(v, 7, PyLong_FromIntMax(st.f_favail));
     PyStructSequence_SET_ITEM(v, 8, PyLong_FromLong((long) st.f_flag));
     PyStructSequence_SET_ITEM(v, 9, PyLong_FromLong((long) st.f_namemax));
 #endif
@@ -11409,13 +11383,9 @@ os_DirEntry_inode_impl(DirEntry *self)
         self->win32_file_index = stat.st_ino;
         self->got_file_index = 1;
     }
-    return PyLong_FromLongLong((long long)self->win32_file_index);
+    return PyLong_FromIntMax(self->win32_file_index);
 #else /* POSIX */
-#ifdef HAVE_LARGEFILE_SUPPORT
-    return PyLong_FromLongLong((long long)self->d_ino);
-#else
-    return PyLong_FromLong((long)self->d_ino);
-#endif
+    return PyLong_FromIntMax(self->d_ino);
 #endif
 }
 
diff -r 46e2755b022c Modules/resource.c
--- a/Modules/resource.c	Fri Nov 25 11:59:52 2016 +0100
+++ b/Modules/resource.c	Fri Nov 25 13:29:08 2016 +0100
@@ -436,12 +436,7 @@ PyInit_resource(void)
     PyModule_AddIntMacro(m, RLIMIT_NPTS);
 #endif
 
-    if (sizeof(RLIM_INFINITY) > sizeof(long)) {
-        v = PyLong_FromLongLong((long long) RLIM_INFINITY);
-    } else
-    {
-        v = PyLong_FromLong((long) RLIM_INFINITY);
-    }
+    v = PyLong_FromIntMax(RLIM_INFINITY);
     if (v) {
         PyModule_AddObject(m, "RLIM_INFINITY", v);
     }
diff -r 46e2755b022c Modules/testcapi_long.h
--- a/Modules/testcapi_long.h	Fri Nov 25 11:59:52 2016 +0100
+++ b/Modules/testcapi_long.h	Fri Nov 25 13:29:08 2016 +0100
@@ -1,6 +1,7 @@
 /* Poor-man's template.  Macros used:
    TESTNAME     name of the test (like test_long_api_inner)
    TYPENAME     the signed type (like long)
+   UTYPENAME    the unsigned type (like unsigned long)
    F_S_TO_PY    convert signed to pylong; TYPENAME -> PyObject*
    F_PY_TO_S    convert pylong to signed; PyObject* -> TYPENAME
    F_U_TO_PY    convert unsigned to pylong; unsigned TYPENAME -> PyObject*
@@ -11,7 +12,7 @@ static PyObject *
 TESTNAME(PyObject *error(const char*))
 {
     const int NBITS = sizeof(TYPENAME) * 8;
-    unsigned TYPENAME base;
+    UTYPENAME base;
     PyObject *pyresult;
     int i;
 
@@ -30,7 +31,7 @@ TESTNAME(PyObject *error(const char*))
         int j;
         for (j = 0; j < 6; ++j) {
             TYPENAME in, out;
-            unsigned TYPENAME uin, uout;
+            UTYPENAME uin, uout;
 
             /* For 0, 1, 2 use base; for 3, 4, 5 use -base */
             uin = j < 3 ? base : 0U - base;
@@ -39,7 +40,7 @@ TESTNAME(PyObject *error(const char*))
              * For 1 & 4, leave alone.
              * For 2 & 5, add 1.
              */
-            uin += (unsigned TYPENAME)(TYPENAME)(j % 3 - 1);
+            uin += (UTYPENAME)(TYPENAME)(j % 3 - 1);
 
             pyresult = F_U_TO_PY(uin);
             if (pyresult == NULL)
@@ -47,7 +48,7 @@ TESTNAME(PyObject *error(const char*))
                  "unsigned unexpected null result");
 
             uout = F_PY_TO_U(pyresult);
-            if (uout == (unsigned TYPENAME)-1 && PyErr_Occurred())
+            if (uout == (UTYPENAME)-1 && PyErr_Occurred())
                 return error(
                     "unsigned unexpected -1 result");
             if (uout != uin)
@@ -79,7 +80,7 @@ TESTNAME(PyObject *error(const char*))
     {
         PyObject *one, *x, *y;
         TYPENAME out;
-        unsigned TYPENAME uout;
+        UTYPENAME uout;
 
         one = PyLong_FromLong(1);
         if (one == NULL)
@@ -93,7 +94,7 @@ TESTNAME(PyObject *error(const char*))
                 "unexpected NULL from PyNumber_Negative");
 
         uout = F_PY_TO_U(x);
-        if (uout != (unsigned TYPENAME)-1 || !PyErr_Occurred())
+        if (uout != (UTYPENAME)-1 || !PyErr_Occurred())
             return error(
                 "PyLong_AsUnsignedXXX(-1) didn't complain");
         if (!PyErr_ExceptionMatches(PyExc_OverflowError))
@@ -116,7 +117,7 @@ TESTNAME(PyObject *error(const char*))
                 "unexpected NULL from PyNumber_Lshift");
 
         uout = F_PY_TO_U(x);
-        if (uout != (unsigned TYPENAME)-1 || !PyErr_Occurred())
+        if (uout != (UTYPENAME)-1 || !PyErr_Occurred())
             return error(
                 "PyLong_AsUnsignedXXX(2**NBITS) didn't "
                 "complain");
@@ -179,7 +180,7 @@ TESTNAME(PyObject *error(const char*))
     /* Test F_PY_TO_{S,U} on non-pylong input. This should raise a TypeError. */
     {
         TYPENAME out;
-        unsigned TYPENAME uout;
+        UTYPENAME uout;
 
         Py_INCREF(Py_None);
 
@@ -192,7 +193,7 @@ TESTNAME(PyObject *error(const char*))
         PyErr_Clear();
 
         uout = F_PY_TO_U(Py_None);
-        if (uout != (unsigned TYPENAME)-1 || !PyErr_Occurred())
+        if (uout != (UTYPENAME)-1 || !PyErr_Occurred())
             return error("PyLong_AsXXX(None) didn't complain");
         if (!PyErr_ExceptionMatches(PyExc_TypeError))
             return error("PyLong_AsXXX(None) raised "
diff -r 46e2755b022c Objects/longobject.c
--- a/Objects/longobject.c	Fri Nov 25 11:59:52 2016 +0100
+++ b/Objects/longobject.c	Fri Nov 25 13:29:08 2016 +0100
@@ -295,6 +295,76 @@ PyLong_FromLong(long ival)
     return (PyObject *)v;
 }
 
+/* Create a new int object from a C intmax_t */
+
+PyObject *
+PyLong_FromIntMax(intmax_t ival)
+{
+    PyLongObject *v;
+    uintmax_t abs_ival;
+    uintmax_t t;  /* unsigned so >> doesn't propagate sign bit */
+    int ndigits = 0;
+    int sign;
+
+    CHECK_SMALL_INT(ival);
+
+    if (ival < 0) {
+        /* negate: can't write this as abs_ival = -ival since that
+           invokes undefined behaviour when ival is LONG_MIN */
+        abs_ival = 0U-(uintmax_t)ival;
+        sign = -1;
+    }
+    else {
+        abs_ival = (uintmax_t)ival;
+        sign = ival == 0 ? 0 : 1;
+    }
+
+    /* Fast path for single-digit ints */
+    if (!(abs_ival >> PyLong_SHIFT)) {
+        v = _PyLong_New(1);
+        if (v) {
+            Py_SIZE(v) = sign;
+            v->ob_digit[0] = Py_SAFE_DOWNCAST(
+                abs_ival, uintmax_t, digit);
+        }
+        return (PyObject*)v;
+    }
+
+#if PyLong_SHIFT==15
+    /* 2 digits */
+    if (!(abs_ival >> 2*PyLong_SHIFT)) {
+        v = _PyLong_New(2);
+        if (v) {
+            Py_SIZE(v) = 2*sign;
+            v->ob_digit[0] = Py_SAFE_DOWNCAST(
+                abs_ival & PyLong_MASK, uintmax_t, digit);
+            v->ob_digit[1] = Py_SAFE_DOWNCAST(
+                  abs_ival >> PyLong_SHIFT, uintmax_t, digit);
+        }
+        return (PyObject*)v;
+    }
+#endif
+
+    /* Larger numbers: loop to determine number of digits */
+    t = abs_ival;
+    while (t) {
+        ++ndigits;
+        t >>= PyLong_SHIFT;
+    }
+    v = _PyLong_New(ndigits);
+    if (v != NULL) {
+        digit *p = v->ob_digit;
+        Py_SIZE(v) = ndigits*sign;
+        t = abs_ival;
+        while (t) {
+            *p++ = Py_SAFE_DOWNCAST(
+                t & PyLong_MASK, uintmax_t, digit);
+            t >>= PyLong_SHIFT;
+        }
+    }
+    return (PyObject *)v;
+}
+
 /* Create a new int object from a C unsigned long int */
 
 PyObject *
@@ -306,12 +376,44 @@ PyLong_FromUnsignedLong(unsigned long iv
 
     if (ival < PyLong_BASE)
         return PyLong_FromLong(ival);
+
     /* Count the number of Python digits. */
-    t = (unsigned long)ival;
+    t = ival;
     while (t) {
         ++ndigits;
         t >>= PyLong_SHIFT;
     }
+
+    v = _PyLong_New(ndigits);
+    if (v != NULL) {
+        digit *p = v->ob_digit;
+        while (ival) {
+            *p++ = (digit)(ival & PyLong_MASK);
+            ival >>= PyLong_SHIFT;
+        }
+    }
+    return (PyObject *)v;
+}
+
+/* Create a new int object from a C intmax_t */
+
+PyObject *
+PyLong_FromUIntMax(uintmax_t ival)
+{
+    PyLongObject *v;
+    uintmax_t t;
+    int ndigits = 0;
+
+    if (ival < PyLong_BASE)
+        return PyLong_FromLong(ival);
+
+    /* Count the number of Python digits. */
+    t = ival;
+    while (t) {
+        ++ndigits;
+        t >>= PyLong_SHIFT;
+    }
+
     v = _PyLong_New(ndigits);
     if (v != NULL) {
         digit *p = v->ob_digit;
@@ -463,7 +565,104 @@ PyLong_AsLongAndOverflow(PyObject *vv, i
     return res;
 }
 
+/* Checking for overflow in PyLong_AsIntMax is a PITA since C doesn't define
+ * anything about what happens when a signed integer operation overflows,
+ * and some compilers think they're doing you a favor by being "clever"
+ * then.  The bit pattern for the largest positive signed long is
+ * (unsigned long)INTMAX_MAX, and for the smallest negative signed long
+ * it is abs(INTMAX_MIN), which we could write -(unsigned long)INTMAX_MIN.
+ * However, some other compilers warn about applying unary minus to an
+ * unsigned operand.  Hence the weird "0-".
+ */
+#define PY_ABS_INTMAX_MIN         (0-(uintmax_t)INTMAX_MIN)
+
 /* Get a C long int from an int object or any object that has an __int__
+   method.
+
+   On overflow, return -1 and set *overflow to 1 or -1 depending on the sign of
+   the result.  Otherwise *overflow is 0.
+
+   For other errors (e.g., TypeError), return -1 and set an error condition.
+   In this case *overflow will be 0.
+*/
+
+intmax_t
+PyLong_AsIntMaxAndOverflow(PyObject *vv, int *overflow)
+{
+    /* This version by Tim Peters */
+    PyLongObject *v;
+    uintmax_t x, prev;
+    intmax_t res;
+    Py_ssize_t i;
+    int sign;
+    int do_decref = 0; /* if nb_int was called */
+
+    *overflow = 0;
+    if (vv == NULL) {
+        PyErr_BadInternalCall();
+        return -1;
+    }
+
+    if (PyLong_Check(vv)) {
+        v = (PyLongObject *)vv;
+    }
+    else {
+        v = _PyLong_FromNbInt(vv);
+        if (v == NULL)
+            return -1;
+        do_decref = 1;
+    }
+
+    res = -1;
+    i = Py_SIZE(v);
+
+    switch (i) {
+    case -1:
+        res = -(sdigit)v->ob_digit[0];
+        break;
+    case 0:
+        res = 0;
+        break;
+    case 1:
+        res = v->ob_digit[0];
+        break;
+    default:
+        sign = 1;
+        x = 0;
+        if (i < 0) {
+            sign = -1;
+            i = -(i);
+        }
+        while (--i >= 0) {
+            prev = x;
+            x = (x << PyLong_SHIFT) | v->ob_digit[i];
+            if ((x >> PyLong_SHIFT) != prev) {
+                *overflow = sign;
+                goto exit;
+            }
+        }
+        /* Haven't lost any bits, but casting to intmax_t requires extra
+         * care (see comment above).
+         */
+        if (x <= (uintmax_t)INTMAX_MAX) {
+            res = (intmax_t)x * sign;
+        }
+        else if (sign < 0 && x == PY_ABS_INTMAX_MIN) {
+            res = INTMAX_MIN;
+        }
+        else {
+            *overflow = sign;
+            /* res is already set to -1 */
+        }
+    }
+  exit:
+    if (do_decref) {
+        Py_DECREF(v);
+    }
+    return res;
+}
+
+/* Get a C long int from a Python int object or any object that has an __int__
    method.  Return -1 and set an error if overflow occurs. */
 
 long
@@ -480,6 +679,23 @@ PyLong_AsLong(PyObject *obj)
     return result;
 }
 
+/* Get a C intmax_t from a Python int object or any object that has an __int__
+   method.  Return -1 and set an error if overflow occurs. */
+
+long
+PyLong_AsIntMax(PyObject *obj)
+{
+    int overflow;
+    long result = PyLong_AsIntMaxAndOverflow(obj, &overflow);
+    if (overflow) {
+        /* XXX: could be cute and give a different
+           message for overflow == -1 */
+        PyErr_SetString(PyExc_OverflowError,
+                        "Python int too large to convert to C long");
+    }
+    return result;
+}
+
 /* Get a C int from an int object or any object that has an __int__
    method.  Return -1 and set an error if overflow occurs. */
 
@@ -553,7 +769,7 @@ PyLong_AsSsize_t(PyObject *vv) {
     return -1;
 }
 
-/* Get a C unsigned long int from an int object.
+/* Get a C unsigned long int from a Python int object.
    Returns -1 and sets an error condition if overflow occurs. */
 
 unsigned long
@@ -597,6 +813,50 @@ PyLong_AsUnsignedLong(PyObject *vv)
     return x;
 }
 
+/* Get a C uintmax_t int from a Python int object.
+   Returns -1 and sets an error condition if overflow occurs. */
+
+uintmax_t
+PyLong_AsUIntMax(PyObject *vv)
+{
+    PyLongObject *v;
+    uintmax_t x, prev;
+    Py_ssize_t i;
+
+    if (vv == NULL) {
+        PyErr_BadInternalCall();
+        return (uintmax_t)-1;
+    }
+    if (!PyLong_Check(vv)) {
+        PyErr_SetString(PyExc_TypeError, "an integer is required");
+        return (uintmax_t)-1;
+    }
+
+    v = (PyLongObject *)vv;
+    i = Py_SIZE(v);
+    x = 0;
+    if (i < 0) {
+        PyErr_SetString(PyExc_OverflowError,
+                        "can't convert negative value to uintmax_t");
+        return (uintmax_t) -1;
+    }
+    switch (i) {
+    case 0: return 0;
+    case 1: return v->ob_digit[0];
+    }
+    while (--i >= 0) {
+        prev = x;
+        x = (x << PyLong_SHIFT) | v->ob_digit[i];
+        if ((x >> PyLong_SHIFT) != prev) {
+            PyErr_SetString(PyExc_OverflowError,
+                            "Python int too large to convert "
+                            "to C uintmax_t");
+            return (uintmax_t) -1;
+        }
+    }
+    return x;
+}
+
 /* Get a C size_t from an int object. Returns (size_t)-1 and sets
    an error condition if overflow occurs. */
 
@@ -1007,16 +1267,7 @@ int
 PyObject *
 PyLong_FromVoidPtr(void *p)
 {
-#if SIZEOF_VOID_P <= SIZEOF_LONG
-    return PyLong_FromUnsignedLong((unsigned long)(uintptr_t)p);
-#else
-
-#if SIZEOF_LONG_LONG < SIZEOF_VOID_P
-#   error "PyLong_FromVoidPtr: sizeof(long long) < sizeof(void*)"
-#endif
-    return PyLong_FromUnsignedLongLong((unsigned long long)(uintptr_t)p);
-#endif /* SIZEOF_VOID_P <= SIZEOF_LONG */
-
+    return PyLong_FromUIntMax((uintptr_t)p);
 }
 
 /* Get a C pointer from an int object. */
@@ -1024,30 +1275,27 @@ PyLong_FromVoidPtr(void *p)
 void *
 PyLong_AsVoidPtr(PyObject *vv)
 {
-#if SIZEOF_VOID_P <= SIZEOF_LONG
-    long x;
-
-    if (PyLong_Check(vv) && _PyLong_Sign(vv) < 0)
-        x = PyLong_AsLong(vv);
-    else
-        x = PyLong_AsUnsignedLong(vv);
-#else
-
-#if SIZEOF_LONG_LONG < SIZEOF_VOID_P
-#   error "PyLong_AsVoidPtr: sizeof(long long) < sizeof(void*)"
-#endif
-    long long x;
-
-    if (PyLong_Check(vv) && _PyLong_Sign(vv) < 0)
-        x = PyLong_AsLongLong(vv);
-    else
-        x = PyLong_AsUnsignedLongLong(vv);
-
-#endif /* SIZEOF_VOID_P <= SIZEOF_LONG */
-
-    if (x == -1 && PyErr_Occurred())
-        return NULL;
-    return (void *)x;
+    uintptr_t u;
+
+    if (PyLong_Check(vv) && _PyLong_Sign(vv) < 0) {
+        intmax_t x = PyLong_AsIntMax(vv);
+        if (x == -1 && PyErr_Occurred()) {
+            return NULL;
+        }
+
+        Py_BUILD_ASSERT(sizeof(uintptr_t) == sizeof(intmax_t));
+        u = (uintptr_t)x;
+    }
+    else {
+        uintmax_t x = PyLong_AsUIntMax(vv);
+        if (x == (uintmax_t)-1 && PyErr_Occurred()) {
+            return NULL;
+        }
+
+        Py_BUILD_ASSERT(sizeof(uintptr_t) == sizeof(uintmax_t));
+        u = (uintptr_t)x;
+    }
+    return (void *)u;
 }
 
 /* Initial long long support by Chris Herborth (chrish@qnx.com), later
diff -r 46e2755b022c PC/pyconfig.h
--- a/PC/pyconfig.h	Fri Nov 25 11:59:52 2016 +0100
+++ b/PC/pyconfig.h	Fri Nov 25 13:29:08 2016 +0100
@@ -346,6 +346,7 @@ Py_NO_ENABLE_SHARED to find out.  Also s
 #define SIZEOF_LONG_LONG 8
 #define SIZEOF_DOUBLE 8
 #define SIZEOF_FLOAT 4
+#define SIZEOF_INTMAX_T 8
 
 /* VC 7.1 has them and VC 6.0 does not.  VC 6.0 has a version number of 1200.
    Microsoft eMbedded Visual C++ 4.0 has a version number of 1201 and doesn't
diff -r 46e2755b022c Python/getargs.c
--- a/Python/getargs.c	Fri Nov 25 11:59:52 2016 +0100
+++ b/Python/getargs.c	Fri Nov 25 13:29:08 2016 +0100
@@ -757,6 +757,7 @@ convertsimple(PyObject *arg, const char 
         *p = ival;
         break;
     }
+
     case 'l': {/* long int */
         long *p = va_arg(*p_va, long *);
         long ival;
@@ -805,6 +806,22 @@ convertsimple(PyObject *arg, const char 
         break;
     }
 
+    case 'm': { /* intmax_t */
+        intmax_t *p = va_arg(*p_va, intmax_t *);
+        intmax_t ival;
+        if (float_argument_error(arg)) {
+            RETURN_ERR_OCCURRED;
+        }
+        ival = PyLong_AsIntMax(arg);
+        if (ival == -1 && PyErr_Occurred()) {
+            RETURN_ERR_OCCURRED;
+        }
+        else {
+            *p = ival;
+        }
+        break;
+    }
+
     case 'f': {/* float */
         float *p = va_arg(*p_va, float *);
         double dval = PyFloat_AsDouble(arg);
@@ -2237,6 +2254,7 @@ skipitem(const char **p_format, va_list 
     case 'L': /* long long */
     case 'K': /* long long sized bitfield */
     case 'n': /* Py_ssize_t */
+    case 'm': /* intmax_t */
     case 'f': /* float */
     case 'd': /* double */
     case 'D': /* complex double */
diff -r 46e2755b022c Python/modsupport.c
--- a/Python/modsupport.c	Fri Nov 25 11:59:52 2016 +0100
+++ b/Python/modsupport.c	Fri Nov 25 13:29:08 2016 +0100
@@ -253,6 +253,9 @@ do_mkvalue(const char **p_format, va_lis
         case 'l':
             return PyLong_FromLong(va_arg(*p_va, long));
 
+        case 'm':
+            return PyLong_FromIntMax(va_arg(*p_va, intmax_t));
+
         case 'k':
         {
             unsigned long n;
diff -r 46e2755b022c Python/pytime.c
--- a/Python/pytime.c	Fri Nov 25 11:59:52 2016 +0100
+++ b/Python/pytime.c	Fri Nov 25 13:29:08 2016 +0100
@@ -38,31 +38,28 @@ error_time_t_overflow(void)
 time_t
 _PyLong_AsTime_t(PyObject *obj)
 {
-#if SIZEOF_TIME_T == SIZEOF_LONG_LONG
-    long long val;
-    val = PyLong_AsLongLong(obj);
-#else
-    long val;
-    Py_BUILD_ASSERT(sizeof(time_t) <= sizeof(long));
-    val = PyLong_AsLong(obj);
-#endif
+    intmax_t val;
+    time_t t;
+
+    val = PyLong_AsIntMax(obj);
     if (val == -1 && PyErr_Occurred()) {
         if (PyErr_ExceptionMatches(PyExc_OverflowError))
             error_time_t_overflow();
         return -1;
     }
-    return (time_t)val;
+
+    t = (time_t)val;
+    if ((intmax_t)t != val) {
+        error_time_t_overflow();
+        return -1;
+    }
+    return t;
 }
 
 PyObject *
 _PyLong_FromTime_t(time_t t)
 {
-#if SIZEOF_TIME_T == SIZEOF_LONG_LONG
-    return PyLong_FromLongLong((long long)t);
-#else
-    Py_BUILD_ASSERT(sizeof(time_t) <= sizeof(long));
-    return PyLong_FromLong((long)t);
-#endif
+    return PyLong_FromIntMax(t);
 }
 
 /* Round to nearest with ties going to nearest even integer
@@ -358,8 +355,7 @@ double
 PyObject *
 _PyTime_AsNanosecondsObject(_PyTime_t t)
 {
-    Py_BUILD_ASSERT(sizeof(long long) >= sizeof(_PyTime_t));
-    return PyLong_FromLongLong((long long)t);
+    return PyLong_FromIntMax(t);
 }
 
 static _PyTime_t
diff -r 46e2755b022c configure
--- a/configure	Fri Nov 25 11:59:52 2016 +0100
+++ b/configure	Fri Nov 25 13:29:08 2016 +0100
@@ -784,7 +784,6 @@ infodir
 docdir
 oldincludedir
 includedir
-runstatedir
 localstatedir
 sharedstatedir
 sysconfdir
@@ -895,7 +894,6 @@ datadir='${datarootdir}'
 sysconfdir='${prefix}/etc'
 sharedstatedir='${prefix}/com'
 localstatedir='${prefix}/var'
-runstatedir='${localstatedir}/run'
 includedir='${prefix}/include'
 oldincludedir='/usr/include'
 docdir='${datarootdir}/doc/${PACKAGE_TARNAME}'
@@ -1148,15 +1146,6 @@ do
   | -silent | --silent | --silen | --sile | --sil)
     silent=yes ;;
 
-  -runstatedir | --runstatedir | --runstatedi | --runstated \
-  | --runstate | --runstat | --runsta | --runst | --runs \
-  | --run | --ru | --r)
-    ac_prev=runstatedir ;;
-  -runstatedir=* | --runstatedir=* | --runstatedi=* | --runstated=* \
-  | --runstate=* | --runstat=* | --runsta=* | --runst=* | --runs=* \
-  | --run=* | --ru=* | --r=*)
-    runstatedir=$ac_optarg ;;
-
   -sbindir | --sbindir | --sbindi | --sbind | --sbin | --sbi | --sb)
     ac_prev=sbindir ;;
   -sbindir=* | --sbindir=* | --sbindi=* | --sbind=* | --sbin=* \
@@ -1294,7 +1283,7 @@ fi
 for ac_var in	exec_prefix prefix bindir sbindir libexecdir datarootdir \
 		datadir sysconfdir sharedstatedir localstatedir includedir \
 		oldincludedir docdir infodir htmldir dvidir pdfdir psdir \
-		libdir localedir mandir runstatedir
+		libdir localedir mandir
 do
   eval ac_val=\$$ac_var
   # Remove trailing slashes.
@@ -1447,7 +1436,6 @@ Fine tuning of the installation director
   --sysconfdir=DIR        read-only single-machine data [PREFIX/etc]
   --sharedstatedir=DIR    modifiable architecture-independent data [PREFIX/com]
   --localstatedir=DIR     modifiable single-machine data [PREFIX/var]
-  --runstatedir=DIR       modifiable per-process data [LOCALSTATEDIR/run]
   --libdir=DIR            object code libraries [EPREFIX/lib]
   --includedir=DIR        C header files [PREFIX/include]
   --oldincludedir=DIR     C header files for non-gcc [/usr/include]
@@ -8738,6 +8726,39 @@ cat >>confdefs.h <<_ACEOF
 _ACEOF
 
 
+# The cast to long int works around a bug in the HP C Compiler
+# version HP92453-01 B.11.11.23709.GP, which incorrectly rejects
+# declarations like `int a3[[(sizeof (unsigned char)) >= 0]];'.
+# This bug is HP SR number 8606223364.
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking size of intmax_t" >&5
+$as_echo_n "checking size of intmax_t... " >&6; }
+if ${ac_cv_sizeof_intmax_t+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if ac_fn_c_compute_int "$LINENO" "(long int) (sizeof (intmax_t))" "ac_cv_sizeof_intmax_t"        "$ac_includes_default"; then :
+
+else
+  if test "$ac_cv_type_intmax_t" = yes; then
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error 77 "cannot compute sizeof (intmax_t)
+See \`config.log' for more details" "$LINENO" 5; }
+   else
+     ac_cv_sizeof_intmax_t=0
+   fi
+fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_sizeof_intmax_t" >&5
+$as_echo "$ac_cv_sizeof_intmax_t" >&6; }
+
+
+
+cat >>confdefs.h <<_ACEOF
+#define SIZEOF_INTMAX_T $ac_cv_sizeof_intmax_t
+_ACEOF
+
+
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for long double support" >&5
 $as_echo_n "checking for long double support... " >&6; }
diff -r 46e2755b022c configure.ac
--- a/configure.ac	Fri Nov 25 11:59:52 2016 +0100
+++ b/configure.ac	Fri Nov 25 13:29:08 2016 +0100
@@ -2203,6 +2203,7 @@ AC_CHECK_SIZEOF(fpos_t, 4)
 AC_CHECK_SIZEOF(size_t, 4)
 AC_CHECK_SIZEOF(pid_t, 4)
 AC_CHECK_SIZEOF(uintptr_t)
+AC_CHECK_SIZEOF(intmax_t)
 
 AC_MSG_CHECKING(for long double support)
 have_long_double=no
diff -r 46e2755b022c pyconfig.h.in
--- a/pyconfig.h.in	Fri Nov 25 11:59:52 2016 +0100
+++ b/pyconfig.h.in	Fri Nov 25 13:29:08 2016 +0100
@@ -1278,6 +1278,9 @@
 /* The size of `int', as computed by sizeof. */
 #undef SIZEOF_INT
 
+/* The size of `intmax_t', as computed by sizeof. */
+#undef SIZEOF_INTMAX_T
+
 /* The size of `long', as computed by sizeof. */
 #undef SIZEOF_LONG