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A new table to help string->integer conversion was added yesterday to

Browse source 
both mystrtoul.c and longobject.c.  Share the table instead.  Also
cut its size by 64 entries (they had been used for an inscrutable
trick originally, but the code no longer tries to use that trick).
This commit is contained in:
Tim Peters 2006-05-25 17:34:03 +00:00
parent e68955cf32
commit da53afa1b0
3 changed files with 16 additions and 44 deletions
Download patch file Download diff file Expand all files Collapse all files

1
Include/longobject.h
View file

@ -25,6 +25,7 @@ PyAPI_FUNC(unsigned long) PyLong_AsUnsignedLongMask(PyObject *);
PyAPI_FUNC(Py_ssize_t) _PyLong_AsSsize_t(PyObject *);
PyAPI_FUNC(PyObject *) _PyLong_FromSize_t(size_t);
PyAPI_FUNC(PyObject *) _PyLong_FromSsize_t(Py_ssize_t);
PyAPI_DATA(int) _PyLong_DigitValue[256];
/* _PyLong_AsScaledDouble returns a double x and an exponent e such that
the true value is approximately equal to x * 2**(SHIFT*e). e is >= 0.

27
Objects/longobject.c
View file

@ -1304,7 +1304,14 @@ long_format(PyObject *aa, int base, int addL)
return (PyObject *)str;
}
static int digval[] = {
/* Table of digit values for 8-bit string -> integer conversion.
* '0' maps to 0, ..., '9' maps to 9.
* 'a' and 'A' map to 10, ..., 'z' and 'Z' map to 35.
* All other indices map to 37.
* Note that when converting a base B string, a char c is a legitimate
* base B digit iff _PyLong_DigitValue[Py_CHARMASK(c)] < B.
*/
int _PyLong_DigitValue[256] = {
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
@ -1321,14 +1328,6 @@ static int digval[] = {
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37
};
/* *str points to the first digit in a string of base `base` digits. base
@ -1355,7 +1354,7 @@ long_from_binary_base(char **str, int base)
n >>= 1;
/* n <- total # of bits needed, while setting p to end-of-string */
n = 0;
while (digval[Py_CHARMASK(*p)] < base)
while (_PyLong_DigitValue[Py_CHARMASK(*p)] < base)
++p;
*str = p;
n = (p - start) * bits_per_char;
@ -1376,7 +1375,7 @@ long_from_binary_base(char **str, int base)
bits_in_accum = 0;
pdigit = z->ob_digit;
while (--p >= start) {
int k = digval[Py_CHARMASK(*p)];
int k = _PyLong_DigitValue[Py_CHARMASK(*p)];
assert(k >= 0 && k < base);
accum |= (twodigits)(k << bits_in_accum);
bits_in_accum += bits_per_char;
@ -1503,7 +1502,7 @@ where B = convmultmax_base[base].
/* Find length of the string of numeric characters. */
scan = str;
while (digval[Py_CHARMASK(*scan)] < base)
while (_PyLong_DigitValue[Py_CHARMASK(*scan)] < base)
++scan;
/* Create a long object that can contain the largest possible
@ -1527,10 +1526,10 @@ where B = convmultmax_base[base].
/* Work ;-) */
while (str < scan) {
/* grab up to convwidth digits from the input string */
c = (digit)digval[Py_CHARMASK(*str++)];
c = (digit)_PyLong_DigitValue[Py_CHARMASK(*str++)];
for (i = 1; i < convwidth && str != scan; ++i, ++str) {
c = (twodigits)(c * base +
digval[Py_CHARMASK(*str)]);
_PyLong_DigitValue[Py_CHARMASK(*str)]);
assert(c < BASE);
}

32
Python/mystrtoul.c
View file

@ -75,34 +75,6 @@ static int digitlimit[] = {
7, 7, 7, 7, 6, 6, 6, 6, 6, 6, /* 20 - 29 */
6, 6, 6, 6, 6, 6, 6}; /* 30 - 36 */
/* char-to-digit conversion for bases 2-36; all non-digits are 37 */
static int digitlookup[] = {
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 37, 37, 37, 37, 37, 37,
37, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24,
25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 37, 37, 37, 37, 37,
37, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24,
25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37,
37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37
};
/*
** strtoul
** This is a general purpose routine for converting
@ -167,7 +139,7 @@ PyOS_strtoul(register char *str, char **ptr, int base)
ovlimit = digitlimit[base];
/* do the conversion until non-digit character encountered */
while ((c = digitlookup[Py_CHARMASK(*str)]) < base) {
while ((c = _PyLong_DigitValue[Py_CHARMASK(*str)]) < base) {
if (ovlimit > 0) /* no overflow check required */
result = result * base + c;
else { /* requires overflow check */
@ -204,7 +176,7 @@ PyOS_strtoul(register char *str, char **ptr, int base)
overflowed:
if (ptr) {
/* spool through remaining digit characters */
while (digitlookup[Py_CHARMASK(*str)] < base)
while (_PyLong_DigitValue[Py_CHARMASK(*str)] < base)
++str;
*ptr = str;
}