mirror of https://github.com/python/cpython
Merged revisions 69634 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk ........ r69634 | mark.dickinson | 2009-02-15 10:13:41 +0000 (Sun, 15 Feb 2009) | 6 lines Issue #5260: Various portability and standards compliance fixes, optimizations and cleanups in Objects/longobject.c. The most significant change is that longs now use less memory: average savings are 2 bytes per long on 32-bit systems and 6 bytes per long on 64-bit systems. (This memory saving already exists in py3k.) ........
This commit is contained in:
Mark Dickinson
parent
32732e3fbd
commit
5a74bf6354
|
|
@ -19,14 +19,13 @@ extern "C" {
|
|||
long_pow() requires that SHIFT be divisible by 5. */
|
||||
|
||||
typedef unsigned short digit;
|
||||
typedef unsigned int wdigit; /* digit widened to parameter size */
|
||||
#define BASE_TWODIGITS_TYPE long
|
||||
typedef unsigned BASE_TWODIGITS_TYPE twodigits;
|
||||
typedef BASE_TWODIGITS_TYPE stwodigits; /* signed variant of twodigits */
|
||||
|
||||
#define PyLong_SHIFT 15
|
||||
#define PyLong_BASE ((digit)1 << PyLong_SHIFT)
|
||||
#define PyLong_MASK ((int)(PyLong_BASE - 1))
|
||||
#define PyLong_MASK ((digit)(PyLong_BASE - 1))
|
||||
|
||||
#if PyLong_SHIFT % 5 != 0
|
||||
#error "longobject.c requires that SHIFT be divisible by 5"
|
||||
|
|
|
|||
|
|
@ -6,6 +6,7 @@
|
|||
#include "longintrepr.h"
|
||||
|
||||
#include <ctype.h>
|
||||
#include <stddef.h>
|
||||
|
||||
#ifndef NSMALLPOSINTS
|
||||
#define NSMALLPOSINTS 257
|
||||
|
|
@ -90,12 +91,6 @@ maybe_small_long(PyLongObject *v)
|
|||
#define MAX(x, y) ((x) < (y) ? (y) : (x))
|
||||
#define MIN(x, y) ((x) > (y) ? (y) : (x))
|
||||
|
||||
/* Forward */
|
||||
static PyLongObject *long_normalize(PyLongObject *);
|
||||
static PyLongObject *mul1(PyLongObject *, wdigit);
|
||||
static PyLongObject *muladd1(PyLongObject *, wdigit, wdigit);
|
||||
static PyLongObject *divrem1(PyLongObject *, digit, digit *);
|
||||
|
||||
#define SIGCHECK(PyTryBlock) \
|
||||
if (--_Py_Ticker < 0) { \
|
||||
_Py_Ticker = _Py_CheckInterval; \
|
||||
|
|
@ -122,25 +117,29 @@ long_normalize(register PyLongObject *v)
|
|||
/* Allocate a new long int object with size digits.
|
||||
Return NULL and set exception if we run out of memory. */
|
||||
|
||||
#define MAX_LONG_DIGITS \
|
||||
((PY_SSIZE_T_MAX - offsetof(PyLongObject, ob_digit))/sizeof(digit))
|
||||
|
||||
PyLongObject *
|
||||
_PyLong_New(Py_ssize_t size)
|
||||
{
|
||||
PyLongObject *result;
|
||||
/* Can't use sizeof(PyLongObject) here, since the
|
||||
compiler takes padding at the end into account.
|
||||
As the consequence, this would waste 2 bytes on
|
||||
a 32-bit system, and 6 bytes on a 64-bit system.
|
||||
This computation would be incorrect on systems
|
||||
which have padding before the digits; with 16-bit
|
||||
digits this should not happen. */
|
||||
result = PyObject_MALLOC(sizeof(PyVarObject) +
|
||||
/* Number of bytes needed is: offsetof(PyLongObject, ob_digit) +
|
||||
sizeof(digit)*size. Previous incarnations of this code used
|
||||
sizeof(PyVarObject) instead of the offsetof, but this risks being
|
||||
incorrect in the presence of padding between the PyVarObject header
|
||||
and the digits. */
|
||||
if (size > MAX_LONG_DIGITS) {
|
||||
PyErr_SetString(PyExc_OverflowError,
|
||||
"too many digits in integer");
|
||||
return NULL;
|
||||
}
|
||||
result = PyObject_MALLOC(offsetof(PyLongObject, ob_digit) +
|
||||
size*sizeof(digit));
|
||||
if (!result) {
|
||||
PyErr_NoMemory();
|
||||
return NULL;
|
||||
}
|
||||
/* XXX(nnorwitz): This can overflow --
|
||||
PyObject_NEW_VAR / _PyObject_VAR_SIZE need to detect overflow */
|
||||
return (PyLongObject*)PyObject_INIT_VAR(result, &PyLong_Type, size);
|
||||
}
|
||||
|
||||
|
|
@ -297,8 +296,8 @@ PyLong_FromDouble(double dval)
|
|||
return NULL;
|
||||
frac = ldexp(frac, (expo-1) % PyLong_SHIFT + 1);
|
||||
for (i = ndig; --i >= 0; ) {
|
||||
long bits = (long)frac;
|
||||
v->ob_digit[i] = (digit) bits;
|
||||
digit bits = (digit)frac;
|
||||
v->ob_digit[i] = bits;
|
||||
frac = frac - (double)bits;
|
||||
frac = ldexp(frac, PyLong_SHIFT);
|
||||
}
|
||||
|
|
@ -667,9 +666,9 @@ _PyLong_FromByteArray(const unsigned char* bytes, size_t n,
|
|||
int incr; /* direction to move pstartbyte */
|
||||
const unsigned char* pendbyte; /* MSB of bytes */
|
||||
size_t numsignificantbytes; /* number of bytes that matter */
|
||||
size_t ndigits; /* number of Python long digits */
|
||||
Py_ssize_t ndigits; /* number of Python long digits */
|
||||
PyLongObject* v; /* result */
|
||||
int idigit = 0; /* next free index in v->ob_digit */
|
||||
Py_ssize_t idigit = 0; /* next free index in v->ob_digit */
|
||||
|
||||
if (n == 0)
|
||||
return PyLong_FromLong(0L);
|
||||
|
|
@ -712,12 +711,16 @@ _PyLong_FromByteArray(const unsigned char* bytes, size_t n,
|
|||
}
|
||||
|
||||
/* How many Python long digits do we need? We have
|
||||
8*numsignificantbytes bits, and each Python long digit has PyLong_SHIFT
|
||||
bits, so it's the ceiling of the quotient. */
|
||||
8*numsignificantbytes bits, and each Python long digit has
|
||||
PyLong_SHIFT bits, so it's the ceiling of the quotient. */
|
||||
/* catch overflow before it happens */
|
||||
if (numsignificantbytes > (PY_SSIZE_T_MAX - PyLong_SHIFT) / 8) {
|
||||
PyErr_SetString(PyExc_OverflowError,
|
||||
"byte array too long to convert to int");
|
||||
return NULL;
|
||||
}
|
||||
ndigits = (numsignificantbytes * 8 + PyLong_SHIFT - 1) / PyLong_SHIFT;
|
||||
if (ndigits > (size_t)INT_MAX)
|
||||
return PyErr_NoMemory();
|
||||
v = _PyLong_New((int)ndigits);
|
||||
v = _PyLong_New(ndigits);
|
||||
if (v == NULL)
|
||||
return NULL;
|
||||
|
||||
|
|
@ -746,8 +749,9 @@ _PyLong_FromByteArray(const unsigned char* bytes, size_t n,
|
|||
accumbits += 8;
|
||||
if (accumbits >= PyLong_SHIFT) {
|
||||
/* There's enough to fill a Python digit. */
|
||||
assert(idigit < (int)ndigits);
|
||||
v->ob_digit[idigit] = (digit)(accum & PyLong_MASK);
|
||||
assert(idigit < ndigits);
|
||||
v->ob_digit[idigit] = (digit)(accum &
|
||||
PyLong_MASK);
|
||||
++idigit;
|
||||
accum >>= PyLong_SHIFT;
|
||||
accumbits -= PyLong_SHIFT;
|
||||
|
|
@ -756,7 +760,7 @@ _PyLong_FromByteArray(const unsigned char* bytes, size_t n,
|
|||
}
|
||||
assert(accumbits < PyLong_SHIFT);
|
||||
if (accumbits) {
|
||||
assert(idigit < (int)ndigits);
|
||||
assert(idigit < ndigits);
|
||||
v->ob_digit[idigit] = (digit)accum;
|
||||
++idigit;
|
||||
}
|
||||
|
|
@ -1409,19 +1413,11 @@ v_isub(digit *x, Py_ssize_t m, digit *y, Py_ssize_t n)
|
|||
/* Multiply by a single digit, ignoring the sign. */
|
||||
|
||||
static PyLongObject *
|
||||
mul1(PyLongObject *a, wdigit n)
|
||||
{
|
||||
return muladd1(a, n, (digit)0);
|
||||
}
|
||||
|
||||
/* Multiply by a single digit and add a single digit, ignoring the sign. */
|
||||
|
||||
static PyLongObject *
|
||||
muladd1(PyLongObject *a, wdigit n, wdigit extra)
|
||||
mul1(PyLongObject *a, digit n)
|
||||
{
|
||||
Py_ssize_t size_a = ABS(Py_SIZE(a));
|
||||
PyLongObject *z = _PyLong_New(size_a+1);
|
||||
twodigits carry = extra;
|
||||
twodigits carry = 0;
|
||||
Py_ssize_t i;
|
||||
|
||||
if (z == NULL)
|
||||
|
|
@ -2034,8 +2030,6 @@ PyLong_FromUnicode(Py_UNICODE *u, Py_ssize_t length, int base)
|
|||
static PyLongObject *x_divrem
|
||||
(PyLongObject *, PyLongObject *, PyLongObject **);
|
||||
static PyObject *long_long(PyObject *v);
|
||||
static int long_divrem(PyLongObject *, PyLongObject *,
|
||||
PyLongObject **, PyLongObject **);
|
||||
|
||||
/* Long division with remainder, top-level routine */
|
||||
|
||||
|
|
@ -2293,14 +2287,12 @@ long_hash(PyLongObject *v)
|
|||
sign = -1;
|
||||
i = -(i);
|
||||
}
|
||||
#define LONG_BIT_PyLong_SHIFT (8*sizeof(long) - PyLong_SHIFT)
|
||||
/* The following loop produces a C unsigned long x such that x is
|
||||
congruent to the absolute value of v modulo ULONG_MAX. The
|
||||
resulting x is nonzero if and only if v is. */
|
||||
while (--i >= 0) {
|
||||
/* Force a native long #-bits (32 or 64) circular shift */
|
||||
x = ((x << PyLong_SHIFT) & ~PyLong_MASK) |
|
||||
((x >> LONG_BIT_PyLong_SHIFT) & PyLong_MASK);
|
||||
x = (x >> (8*SIZEOF_LONG-PyLong_SHIFT)) | (x << PyLong_SHIFT);
|
||||
x += v->ob_digit[i];
|
||||
/* If the addition above overflowed we compensate by
|
||||
incrementing. This preserves the value modulo
|
||||
|
|
@ -2308,11 +2300,10 @@ long_hash(PyLongObject *v)
|
|||
if (x < v->ob_digit[i])
|
||||
x++;
|
||||
}
|
||||
#undef LONG_BIT_PyLong_SHIFT
|
||||
x = x * sign;
|
||||
if (x == -1)
|
||||
x = -2;
|
||||
return x;
|
||||
if (x == (unsigned long)-1)
|
||||
x = (unsigned long)-2;
|
||||
return (long)x;
|
||||
}
|
||||
|
||||
|
||||
|
|
@ -3566,12 +3557,12 @@ long_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
|
|||
/* Since PyLong_FromString doesn't have a length parameter,
|
||||
* check here for possible NULs in the string. */
|
||||
char *string;
|
||||
int size = Py_SIZE(x);
|
||||
Py_ssize_t size = Py_SIZE(x);
|
||||
if (PyByteArray_Check(x))
|
||||
string = PyByteArray_AS_STRING(x);
|
||||
else
|
||||
string = PyBytes_AS_STRING(x);
|
||||
if (strlen(string) != size) {
|
||||
if (strlen(string) != (size_t)size) {
|
||||
/* We only see this if there's a null byte in x,
|
||||
x is a bytes or buffer, *and* a base is given. */
|
||||
PyErr_Format(PyExc_ValueError,
|
||||
|
|
@ -3784,7 +3775,7 @@ long_sizeof(PyLongObject *v)
|
|||
{
|
||||
Py_ssize_t res;
|
||||
|
||||
res = sizeof(PyVarObject) + abs(Py_SIZE(v))*sizeof(digit);
|
||||
res = offsetof(PyLongObject, ob_digit) + ABS(Py_SIZE(v))*sizeof(digit);
|
||||
return PyLong_FromSsize_t(res);
|
||||
}
|
||||
|
||||
|
|
@ -3959,9 +3950,7 @@ static PyNumberMethods long_as_number = {
|
|||
PyTypeObject PyLong_Type = {
|
||||
PyVarObject_HEAD_INIT(&PyType_Type, 0)
|
||||
"int", /* tp_name */
|
||||
/* See _PyLong_New for why this isn't
|
||||
sizeof(PyLongObject) - sizeof(digit) */
|
||||
sizeof(PyVarObject), /* tp_basicsize */
|
||||
offsetof(PyLongObject, ob_digit), /* tp_basicsize */
|
||||
sizeof(digit), /* tp_itemsize */
|
||||
long_dealloc, /* tp_dealloc */
|
||||
0, /* tp_print */
|
||||
|
|
|
|||
Loading…
Reference in New Issue