cpython/Objects/intobject.c at 2.7 · python-emscripten/cpython · GitHub

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/* Integer object implementation */

#include "Python.h"

#include <ctype.h>

#include <float.h>

static PyObject *int_int(PyIntObject *v);

long

PyInt_GetMax(void)

{

return LONG_MAX; /* To initialize sys.maxint */

}

/* Integers are quite normal objects, to make object handling uniform.

(Using odd pointers to represent integers would save much space

but require extra checks for this special case throughout the code.)

Since a typical Python program spends much of its time allocating

and deallocating integers, these operations should be very fast.

Therefore we use a dedicated allocation scheme with a much lower

overhead (in space and time) than straight malloc(): a simple

dedicated free list, filled when necessary with memory from malloc().

block_list is a singly-linked list of all PyIntBlocks ever allocated,

linked via their next members. PyIntBlocks are never returned to the

system before shutdown (PyInt_Fini).

free_list is a singly-linked list of available PyIntObjects, linked

via abuse of their ob_type members.

#define BLOCK_SIZE 1000 /* 1K less typical malloc overhead */

#define BHEAD_SIZE 8 /* Enough for a 64-bit pointer */

#define N_INTOBJECTS ((BLOCK_SIZE - BHEAD_SIZE) / sizeof(PyIntObject))

struct _intblock {

struct _intblock *next;

PyIntObject objects[N_INTOBJECTS];

};

typedef struct _intblock PyIntBlock;

static PyIntBlock *block_list = NULL;

static PyIntObject *free_list = NULL;

static PyIntObject *

fill_free_list(void)

{

PyIntObject *p, *q;

/* Python's object allocator isn't appropriate for large blocks. */

p = (PyIntObject *) PyMem_MALLOC(sizeof(PyIntBlock));

if (p == NULL)

return (PyIntObject *) PyErr_NoMemory();

((PyIntBlock *)p)->next = block_list;

block_list = (PyIntBlock *)p;

/* Link the int objects together, from rear to front, then return

the address of the last int object in the block. */

p = &((PyIntBlock *)p)->objects[0];

q = p + N_INTOBJECTS;

while (--q > p)

Py_TYPE(q) = (struct _typeobject *)(q-1);

Py_TYPE(q) = NULL;

return p + N_INTOBJECTS - 1;

}

#ifndef NSMALLPOSINTS

#define NSMALLPOSINTS 257

#endif

#ifndef NSMALLNEGINTS

#define NSMALLNEGINTS 5

#endif

#if NSMALLNEGINTS + NSMALLPOSINTS > 0

/* References to small integers are saved in this array so that they

can be shared.

The integers that are saved are those in the range

-NSMALLNEGINTS (inclusive) to NSMALLPOSINTS (not inclusive).

static PyIntObject *small_ints[NSMALLNEGINTS + NSMALLPOSINTS];

#endif

#ifdef COUNT_ALLOCS

Py_ssize_t quick_int_allocs;

Py_ssize_t quick_neg_int_allocs;

#endif

PyObject *

PyInt_FromLong(long ival)

{

#if NSMALLNEGINTS + NSMALLPOSINTS > 0

if (-NSMALLNEGINTS <= ival && ival < NSMALLPOSINTS) {

v = small_ints[ival + NSMALLNEGINTS];

Py_INCREF(v);

#ifdef COUNT_ALLOCS

if (ival >= 0)

quick_int_allocs++;

else

quick_neg_int_allocs++;

#endif

return (PyObject *) v;

}

#endif

if (free_list == NULL) {

if ((free_list = fill_free_list()) == NULL)

return NULL;

}

/* Inline PyObject_New */

v = free_list;

free_list = (PyIntObject *)Py_TYPE(v);

(void)PyObject_INIT(v, &PyInt_Type);

v->ob_ival = ival;

return (PyObject *) v;

}

PyObject *

PyInt_FromSize_t(size_t ival)

{

if (ival <= LONG_MAX)

return PyInt_FromLong((long)ival);

return _PyLong_FromSize_t(ival);

}

PyObject *

PyInt_FromSsize_t(Py_ssize_t ival)

{

if (ival >= LONG_MIN && ival <= LONG_MAX)

return PyInt_FromLong((long)ival);

return _PyLong_FromSsize_t(ival);

}

static void

int_dealloc(PyIntObject *v)

{

if (PyInt_CheckExact(v)) {

Py_TYPE(v) = (struct _typeobject *)free_list;

free_list = v;

}

else

Py_TYPE(v)->tp_free((PyObject *)v);

}

long

PyInt_AsLong(register PyObject *op)

{

PyNumberMethods *nb;

PyIntObject *io;

long val;

if (op && PyInt_Check(op))

return PyInt_AS_LONG((PyIntObject*) op);

if (op == NULL || (nb = Py_TYPE(op)->tp_as_number) == NULL ||

nb->nb_int == NULL) {

PyErr_SetString(PyExc_TypeError, "an integer is required");

return -1;

}

if (PyLong_CheckExact(op)) {

/* avoid creating temporary int object */

return PyLong_AsLong(op);

}

io = (PyIntObject*) (*nb->nb_int) (op);

if (io == NULL)

return -1;

if (!PyInt_Check(io)) {

if (PyLong_Check(io)) {

/* got a long? => retry int conversion */

val = PyLong_AsLong((PyObject *)io);

Py_DECREF(io);

return val;

}

else

{

Py_DECREF(io);

PyErr_SetString(PyExc_TypeError,

"__int__ method should return an integer");

return -1;

}

val = PyInt_AS_LONG(io);

Py_DECREF(io);

return val;

}

int

_PyInt_AsInt(PyObject *obj)

{

long result = PyInt_AsLong(obj);

if (result == -1 && PyErr_Occurred())

return -1;

if (result > INT_MAX || result < INT_MIN) {

PyErr_SetString(PyExc_OverflowError,

"Python int too large to convert to C int");

return -1;

}

return (int)result;

}

Py_ssize_t

PyInt_AsSsize_t(register PyObject *op)

{

#if SIZEOF_SIZE_T != SIZEOF_LONG

PyNumberMethods *nb;

PyObject *io;

Py_ssize_t val;

#endif

if (op == NULL) {

PyErr_SetString(PyExc_TypeError, "an integer is required");

return -1;

}

if (PyInt_Check(op))

return PyInt_AS_LONG((PyIntObject*) op);

if (PyLong_Check(op))

return _PyLong_AsSsize_t(op);

#if SIZEOF_SIZE_T == SIZEOF_LONG

return PyInt_AsLong(op);

#else

if ((nb = Py_TYPE(op)->tp_as_number) == NULL ||

(nb->nb_int == NULL && nb->nb_long == 0)) {

PyErr_SetString(PyExc_TypeError, "an integer is required");

return -1;

}

if (nb->nb_long != 0)

io = (*nb->nb_long)(op);

else

io = (*nb->nb_int)(op);

if (io == NULL)

return -1;

if (!PyInt_Check(io)) {

if (PyLong_Check(io)) {

/* got a long? => retry int conversion */

val = _PyLong_AsSsize_t(io);

Py_DECREF(io);

if ((val == -1) && PyErr_Occurred())

return -1;

return val;

}

else

{

Py_DECREF(io);

PyErr_SetString(PyExc_TypeError,

"__int__ method should return an integer");

return -1;

}

val = PyInt_AS_LONG(io);

Py_DECREF(io);

return val;

#endif

}

unsigned long

PyInt_AsUnsignedLongMask(register PyObject *op)

{

PyNumberMethods *nb;

PyIntObject *io;

unsigned long val;

if (op && PyInt_Check(op))

return PyInt_AS_LONG((PyIntObject*) op);

if (op && PyLong_Check(op))

return PyLong_AsUnsignedLongMask(op);

if (op == NULL || (nb = Py_TYPE(op)->tp_as_number) == NULL ||

nb->nb_int == NULL) {

PyErr_SetString(PyExc_TypeError, "an integer is required");

return (unsigned long)-1;

}

io = (PyIntObject*) (*nb->nb_int) (op);

if (io == NULL)

return (unsigned long)-1;

if (!PyInt_Check(io)) {

if (PyLong_Check(io)) {

val = PyLong_AsUnsignedLongMask((PyObject *)io);

Py_DECREF(io);

if (PyErr_Occurred())

return (unsigned long)-1;

return val;

}

else

{

Py_DECREF(io);

PyErr_SetString(PyExc_TypeError,

"__int__ method should return an integer");

return (unsigned long)-1;

}

val = PyInt_AS_LONG(io);

Py_DECREF(io);

return val;

}

#ifdef HAVE_LONG_LONG

unsigned PY_LONG_LONG

PyInt_AsUnsignedLongLongMask(register PyObject *op)

{

PyNumberMethods *nb;

PyIntObject *io;

unsigned PY_LONG_LONG val;

if (op && PyInt_Check(op))

return PyInt_AS_LONG((PyIntObject*) op);

if (op && PyLong_Check(op))

return PyLong_AsUnsignedLongLongMask(op);

if (op == NULL || (nb = Py_TYPE(op)->tp_as_number) == NULL ||

nb->nb_int == NULL) {

PyErr_SetString(PyExc_TypeError, "an integer is required");

return (unsigned PY_LONG_LONG)-1;

}

io = (PyIntObject*) (*nb->nb_int) (op);

if (io == NULL)

return (unsigned PY_LONG_LONG)-1;

if (!PyInt_Check(io)) {

if (PyLong_Check(io)) {

val = PyLong_AsUnsignedLongLongMask((PyObject *)io);

Py_DECREF(io);

if (PyErr_Occurred())

return (unsigned PY_LONG_LONG)-1;

return val;

}

else

{

Py_DECREF(io);

PyErr_SetString(PyExc_TypeError,

"__int__ method should return an integer");

return (unsigned PY_LONG_LONG)-1;

}

val = PyInt_AS_LONG(io);

Py_DECREF(io);

return val;

}

#endif

PyObject *

PyInt_FromString(char *s, char **pend, int base)

{

char *end;

long x;

Py_ssize_t slen;

PyObject *sobj, *srepr;

if ((base != 0 && base < 2) || base > 36) {

PyErr_SetString(PyExc_ValueError,

"int() base must be >= 2 and <= 36, or 0");

return NULL;

}

while (*s && isspace(Py_CHARMASK(*s)))

s++;

errno = 0;

if (base == 0 && s[0] == '0') {

x = (long) PyOS_strtoul(s, &end, base);

if (x < 0)

return PyLong_FromString(s, pend, base);

}

else

x = PyOS_strtol(s, &end, base);

if (end == s || !isalnum(Py_CHARMASK(end[-1])))

goto bad;

while (*end && isspace(Py_CHARMASK(*end)))

end++;

if (*end != '\0') {

bad:

slen = strlen(s) < 200 ? strlen(s) : 200;

sobj = PyString_FromStringAndSize(s, slen);

if (sobj == NULL)

return NULL;

srepr = PyObject_Repr(sobj);

Py_DECREF(sobj);

if (srepr == NULL)

return NULL;

PyErr_Format(PyExc_ValueError,

"invalid literal for int() with base %d: %s",

base, PyString_AS_STRING(srepr));

Py_DECREF(srepr);

return NULL;

}

else if (errno != 0)

return PyLong_FromString(s, pend, base);

if (pend)

*pend = end;

return PyInt_FromLong(x);

}

#ifdef Py_USING_UNICODE

PyObject *

PyInt_FromUnicode(Py_UNICODE *s, Py_ssize_t length, int base)

{

PyObject *result;

char *buffer = (char *)PyMem_MALLOC(length+1);

if (buffer == NULL)

return PyErr_NoMemory();

if (PyUnicode_EncodeDecimal(s, length, buffer, NULL)) {

PyMem_FREE(buffer);

return NULL;

}

result = PyInt_FromString(buffer, NULL, base);

PyMem_FREE(buffer);

return result;

}

#endif

/* Methods */

/* Integers are seen as the "smallest" of all numeric types and thus

don't have any knowledge about conversion of other types to

integers. */

#define CONVERT_TO_LONG(obj, lng) \

if (PyInt_Check(obj)) { \

lng = PyInt_AS_LONG(obj); \

} \

else { \

Py_INCREF(Py_NotImplemented); \

return Py_NotImplemented; \

}

/* ARGSUSED */

static int

int_print(PyIntObject *v, FILE *fp, int flags)

/* flags -- not used but required by interface */

{

long int_val = v->ob_ival;

Py_BEGIN_ALLOW_THREADS

fprintf(fp, "%ld", int_val);

Py_END_ALLOW_THREADS

return 0;

}

static int

int_compare(PyIntObject *v, PyIntObject *w)

{

return (i < j) ? -1 : (i > j) ? 1 : 0;

}

static long

int_hash(PyIntObject *v)

{

/* XXX If this is changed, you also need to change the way

Python's long, float and complex types are hashed. */

long x = v -> ob_ival;

if (x == -1)

x = -2;

return x;

}

static PyObject *

int_add(PyIntObject *v, PyIntObject *w)

{

CONVERT_TO_LONG(v, a);

CONVERT_TO_LONG(w, b);

/* casts in the line below avoid undefined behaviour on overflow */

x = (long)((unsigned long)a + b);

if ((x^a) >= 0 || (x^b) >= 0)

return PyInt_FromLong(x);

return PyLong_Type.tp_as_number->nb_add((PyObject *)v, (PyObject *)w);

}

static PyObject *

int_sub(PyIntObject *v, PyIntObject *w)

{

CONVERT_TO_LONG(v, a);

CONVERT_TO_LONG(w, b);

/* casts in the line below avoid undefined behaviour on overflow */

x = (long)((unsigned long)a - b);

if ((x^a) >= 0 || (x^~b) >= 0)

return PyInt_FromLong(x);

return PyLong_Type.tp_as_number->nb_subtract((PyObject *)v,

(PyObject *)w);

}

Integer overflow checking for * is painful: Python tried a couple ways, but

they didn't work on all platforms, or failed in endcases (a product of

-sys.maxint-1 has been a particular pain).

Here's another way:

The native long product x*y is either exactly right or *way* off, being

just the last n bits of the true product, where n is the number of bits

in a long (the delivered product is the true product plus i*2**n for

some integer i).

The native double product (double)x * (double)y is subject to three

rounding errors: on a sizeof(long)==8 box, each cast to double can lose

info, and even on a sizeof(long)==4 box, the multiplication can lose info.

But, unlike the native long product, it's not in *range* trouble: even

if sizeof(long)==32 (256-bit longs), the product easily fits in the

dynamic range of a double. So the leading 50 (or so) bits of the double

product are correct.

We check these two ways against each other, and declare victory if they're

approximately the same. Else, because the native long product is the only

one that can lose catastrophic amounts of information, it's the native long

product that must have overflowed.

static PyObject *

int_mul(PyObject *v, PyObject *w)

{

long a, b;

long longprod; /* a*b in native long arithmetic */

double doubled_longprod; /* (double)longprod */

double doubleprod; /* (double)a * (double)b */

CONVERT_TO_LONG(v, a);

CONVERT_TO_LONG(w, b);

/* casts in the next line avoid undefined behaviour on overflow */

longprod = (long)((unsigned long)a * b);

doubleprod = (double)a * (double)b;

doubled_longprod = (double)longprod;

/* Fast path for normal case: small multiplicands, and no info

is lost in either method. */

if (doubled_longprod == doubleprod)

return PyInt_FromLong(longprod);

/* Somebody somewhere lost info. Close enough, or way off? Note

that a != 0 and b != 0 (else doubled_longprod == doubleprod == 0).

The difference either is or isn't significant compared to the

true value (of which doubleprod is a good approximation).

{

const double diff = doubled_longprod - doubleprod;

const double absdiff = diff >= 0.0 ? diff : -diff;

const double absprod = doubleprod >= 0.0 ? doubleprod :

-doubleprod;

/* absdiff/absprod <= 1/32 iff

32 * absdiff <= absprod -- 5 good bits is "close enough" */

if (32.0 * absdiff <= absprod)

return PyInt_FromLong(longprod);

else

return PyLong_Type.tp_as_number->nb_multiply(v, w);

}

/* Integer overflow checking for unary negation: on a 2's-complement

* box, -x overflows iff x is the most negative long. In this case we

* get -x == x. However, -x is undefined (by C) if x /is/ the most

* negative long (it's a signed overflow case), and some compilers care.

* So we cast x to unsigned long first. However, then other compilers

* warn about applying unary minus to an unsigned operand. Hence the

* weird "0-".

#define UNARY_NEG_WOULD_OVERFLOW(x) \

((x) < 0 && (unsigned long)(x) == 0-(unsigned long)(x))

/* Return type of i_divmod */

enum divmod_result {

DIVMOD_OK, /* Correct result */

DIVMOD_OVERFLOW, /* Overflow, try again using longs */

DIVMOD_ERROR /* Exception raised */

};

static enum divmod_result

i_divmod(register long x, register long y,

long *p_xdivy, long *p_xmody)

{

long xdivy, xmody;

if (y == 0) {

PyErr_SetString(PyExc_ZeroDivisionError,

"integer division or modulo by zero");

return DIVMOD_ERROR;

}

/* (-sys.maxint-1)/-1 is the only overflow case. */

if (y == -1 && UNARY_NEG_WOULD_OVERFLOW(x))

return DIVMOD_OVERFLOW;

xdivy = x / y;

/* xdiv*y can overflow on platforms where x/y gives floor(x/y)

* for x and y with differing signs. (This is unusual

* behaviour, and C99 prohibits it, but it's allowed by C89;

* for an example of overflow, take x = LONG_MIN, y = 5 or x =

* LONG_MAX, y = -5.) However, x - xdivy*y is always

* representable as a long, since it lies strictly between

* -abs(y) and abs(y). We add casts to avoid intermediate

* overflow.

xmody = (long)(x - (unsigned long)xdivy * y);

/* If the signs of x and y differ, and the remainder is non-0,

* C89 doesn't define whether xdivy is now the floor or the

* ceiling of the infinitely precise quotient. We want the floor,

* and we have it iff the remainder's sign matches y's.

if (xmody && ((y ^ xmody) < 0) /* i.e. and signs differ */) {

xmody += y;

--xdivy;

assert(xmody && ((y ^ xmody) >= 0));

}

*p_xdivy = xdivy;

*p_xmody = xmody;

return DIVMOD_OK;

}

static PyObject *

int_div(PyIntObject *x, PyIntObject *y)

{

long xi, yi;

long d, m;

CONVERT_TO_LONG(x, xi);

CONVERT_TO_LONG(y, yi);

switch (i_divmod(xi, yi, &d, &m)) {

case DIVMOD_OK:

return PyInt_FromLong(d);

case DIVMOD_OVERFLOW:

return PyLong_Type.tp_as_number->nb_divide((PyObject *)x,

(PyObject *)y);

default:

return NULL;

}

static PyObject *

int_classic_div(PyIntObject *x, PyIntObject *y)

{

long xi, yi;

long d, m;

CONVERT_TO_LONG(x, xi);

CONVERT_TO_LONG(y, yi);

if (Py_DivisionWarningFlag &&

PyErr_Warn(PyExc_DeprecationWarning, "classic int division") < 0)

return NULL;

switch (i_divmod(xi, yi, &d, &m)) {

case DIVMOD_OK:

return PyInt_FromLong(d);

case DIVMOD_OVERFLOW:

return PyLong_Type.tp_as_number->nb_divide((PyObject *)x,

(PyObject *)y);

default:

return NULL;

}

static PyObject *

int_true_divide(PyIntObject *x, PyIntObject *y)

{

long xi, yi;

/* If they aren't both ints, give someone else a chance. In

particular, this lets int/long get handled by longs, which

underflows to 0 gracefully if the long is too big to convert

to float. */

CONVERT_TO_LONG(x, xi);

CONVERT_TO_LONG(y, yi);

if (yi == 0) {

PyErr_SetString(PyExc_ZeroDivisionError,

"division by zero");

return NULL;

}

if (xi == 0)

return PyFloat_FromDouble(yi < 0 ? -0.0 : 0.0);

#define WIDTH_OF_ULONG (CHAR_BIT*SIZEOF_LONG)

#if DBL_MANT_DIG < WIDTH_OF_ULONG

if ((xi >= 0 ? 0UL + xi : 0UL - xi) >> DBL_MANT_DIG ||

(yi >= 0 ? 0UL + yi : 0UL - yi) >> DBL_MANT_DIG)

/* Large x or y. Use long integer arithmetic. */

return PyLong_Type.tp_as_number->nb_true_divide(

(PyObject *)x, (PyObject *)y);

else

#endif

/* Both ints can be exactly represented as doubles. Do a

floating-point division. */

return PyFloat_FromDouble((double)xi / (double)yi);

}

static PyObject *

int_mod(PyIntObject *x, PyIntObject *y)

{

long xi, yi;

long d, m;

CONVERT_TO_LONG(x, xi);

CONVERT_TO_LONG(y, yi);

switch (i_divmod(xi, yi, &d, &m)) {

case DIVMOD_OK:

return PyInt_FromLong(m);

case DIVMOD_OVERFLOW:

return PyLong_Type.tp_as_number->nb_remainder((PyObject *)x,

(PyObject *)y);

default:

return NULL;

}

static PyObject *

int_divmod(PyIntObject *x, PyIntObject *y)

{

long xi, yi;

long d, m;

CONVERT_TO_LONG(x, xi);

CONVERT_TO_LONG(y, yi);

switch (i_divmod(xi, yi, &d, &m)) {

case DIVMOD_OK:

return Py_BuildValue("(ll)", d, m);

case DIVMOD_OVERFLOW:

return PyLong_Type.tp_as_number->nb_divmod((PyObject *)x,

(PyObject *)y);

default:

return NULL;

}

static PyObject *

int_pow(PyIntObject *v, PyIntObject *w, PyIntObject *z)

{

CONVERT_TO_LONG(v, iv);

CONVERT_TO_LONG(w, iw);

if (iw < 0) {

if ((PyObject *)z != Py_None) {

PyErr_SetString(PyExc_TypeError, "pow() 2nd argument "

"cannot be negative when 3rd argument specified");

return NULL;

}

/* Return a float. This works because we know that

this calls float_pow() which converts its

arguments to double. */

return PyFloat_Type.tp_as_number->nb_power(

(PyObject *)v, (PyObject *)w, (PyObject *)z);

}

if ((PyObject *)z != Py_None) {

CONVERT_TO_LONG(z, iz);

if (iz == 0) {

PyErr_SetString(PyExc_ValueError,

"pow() 3rd argument cannot be 0");

return NULL;

}

* XXX: The original exponentiation code stopped looping

* when temp hit zero; this code will continue onwards

* unnecessarily, but at least it won't cause any errors.

* Hopefully the speed improvement from the fast exponentiation

* will compensate for the slight inefficiency.

* XXX: Better handling of overflows is desperately needed.

temp = iv;

ix = 1;

while (iw > 0) {

prev = ix; /* Save value for overflow check */

if (iw & 1) {

* The (unsigned long) cast below ensures that the multiplication

* is interpreted as an unsigned operation rather than a signed one

* (C99 6.3.1.8p1), thus avoiding the perils of undefined behaviour

* from signed arithmetic overflow (C99 6.5p5). See issue #12973.

ix = (unsigned long)ix * temp;

if (temp == 0)

break; /* Avoid ix / 0 */

if (ix / temp != prev) {

return PyLong_Type.tp_as_number->nb_power(

(PyObject *)v,

(PyObject *)w,

(PyObject *)z);

}

iw >>= 1; /* Shift exponent down by 1 bit */

if (iw==0) break;

prev = temp;

temp = (unsigned long)temp * temp; /* Square the value of temp */

if (prev != 0 && temp / prev != prev) {

return PyLong_Type.tp_as_number->nb_power(

(PyObject *)v, (PyObject *)w, (PyObject *)z);

}

if (iz) {

/* If we did a multiplication, perform a modulo */

ix = ix % iz;

temp = temp % iz;

}

if (iz) {

long div, mod;

switch (i_divmod(ix, iz, &div, &mod)) {

case DIVMOD_OK:

ix = mod;

break;

case DIVMOD_OVERFLOW:

return PyLong_Type.tp_as_number->nb_power(

(PyObject *)v, (PyObject *)w, (PyObject *)z);

default:

return NULL;

}

return PyInt_FromLong(ix);

}

static PyObject *

int_neg(PyIntObject *v)

{

a = v->ob_ival;

/* check for overflow */

if (UNARY_NEG_WOULD_OVERFLOW(a)) {

PyObject *o = PyLong_FromLong(a);

if (o != NULL) {

PyObject *result = PyNumber_Negative(o);

Py_DECREF(o);

return result;

}

return NULL;

}

return PyInt_FromLong(-a);

}

static PyObject *

int_abs(PyIntObject *v)

{

if (v->ob_ival >= 0)

return int_int(v);

else

return int_neg(v);

}

static int

int_nonzero(PyIntObject *v)

{

return v->ob_ival != 0;

}

static PyObject *

int_invert(PyIntObject *v)

{

return PyInt_FromLong(~v->ob_ival);

}

static PyObject *

int_lshift(PyIntObject *v, PyIntObject *w)

{

long a, b, c;

PyObject *vv, *ww, *result;

CONVERT_TO_LONG(v, a);

CONVERT_TO_LONG(w, b);

if (b < 0) {

PyErr_SetString(PyExc_ValueError, "negative shift count");

return NULL;

}

if (a == 0 || b == 0)

return int_int(v);

if (b >= LONG_BIT) {

vv = PyLong_FromLong(PyInt_AS_LONG(v));

if (vv == NULL)

return NULL;

ww = PyLong_FromLong(PyInt_AS_LONG(w));

if (ww == NULL) {

Py_DECREF(vv);

return NULL;

}

result = PyNumber_Lshift(vv, ww);

Py_DECREF(vv);

Py_DECREF(ww);

return result;

}

c = a << b;

if (a != Py_ARITHMETIC_RIGHT_SHIFT(long, c, b)) {

vv = PyLong_FromLong(PyInt_AS_LONG(v));

if (vv == NULL)

return NULL;

ww = PyLong_FromLong(PyInt_AS_LONG(w));

if (ww == NULL) {

Py_DECREF(vv);

return NULL;

}

result = PyNumber_Lshift(vv, ww);

Py_DECREF(vv);

Py_DECREF(ww);

return result;

}

return PyInt_FromLong(c);

}

static PyObject *

int_rshift(PyIntObject *v, PyIntObject *w)

{

CONVERT_TO_LONG(v, a);

CONVERT_TO_LONG(w, b);

if (b < 0) {

PyErr_SetString(PyExc_ValueError, "negative shift count");

return NULL;

}

if (a == 0 || b == 0)

return int_int(v);

if (b >= LONG_BIT) {

if (a < 0)

a = -1;

else

a = 0;

}

else {

a = Py_ARITHMETIC_RIGHT_SHIFT(long, a, b);

}

return PyInt_FromLong(a);

}

static PyObject *

int_and(PyIntObject *v, PyIntObject *w)

{

CONVERT_TO_LONG(v, a);

CONVERT_TO_LONG(w, b);

return PyInt_FromLong(a & b);

}

static PyObject *

int_xor(PyIntObject *v, PyIntObject *w)

{

CONVERT_TO_LONG(v, a);

CONVERT_TO_LONG(w, b);

return PyInt_FromLong(a ^ b);

}

static PyObject *

int_or(PyIntObject *v, PyIntObject *w)

{

CONVERT_TO_LONG(v, a);

CONVERT_TO_LONG(w, b);

return PyInt_FromLong(a | b);

}

static int

int_coerce(PyObject **pv, PyObject **pw)

{

if (PyInt_Check(*pw)) {

Py_INCREF(*pv);

Py_INCREF(*pw);

return 0;

}

return 1; /* Can't do it */

}

static PyObject *

int_int(PyIntObject *v)

{

if (PyInt_CheckExact(v))

Py_INCREF(v);

else

v = (PyIntObject *)PyInt_FromLong(v->ob_ival);

return (PyObject *)v;

}

static PyObject *

int_long(PyIntObject *v)

{

return PyLong_FromLong((v -> ob_ival));

}

static const unsigned char BitLengthTable[32] = {

0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4,

5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5

};

static int

bits_in_ulong(unsigned long d)

{

int d_bits = 0;

while (d >= 32) {

d_bits += 6;

d >>= 6;

}

d_bits += (int)BitLengthTable[d];

return d_bits;

}

#if 8*SIZEOF_LONG-1 <= DBL_MANT_DIG

/* Every Python int can be exactly represented as a float. */

static PyObject *

int_float(PyIntObject *v)

{

return PyFloat_FromDouble((double)(v -> ob_ival));

}

#else

/* Here not all Python ints are exactly representable as floats, so we may

View remainder of file in raw view

cpython/Objects/intobject.c at 2.7 · python-emscripten/cpython · GitHub

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