From: Tim Peters <tim.peters@gmail.com>
Date: Thu, 25 May 2006 17:34:03 +0000 (+0000)
Subject: A new table to help string->integer conversion was added yesterday to
X-Git-Tag: v2.5b1~533
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=da53afa1b09218c0fb7ce8803cd783a43ee9d319;p=thirdparty%2FPython%2Fcpython.git

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

diff --git a/Include/longobject.h b/Include/longobject.h
index 77544ef158b1..eef4e9b4bcb8 100644
--- a/Include/longobject.h
+++ b/Include/longobject.h
@@ -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.
diff --git a/Objects/longobject.c b/Objects/longobject.c
index dc2311a435b7..9b1a0b977726 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -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);
 			}
 
diff --git a/Python/mystrtoul.c b/Python/mystrtoul.c
index 272f827c8cf4..380b37da9033 100644
--- a/Python/mystrtoul.c
+++ b/Python/mystrtoul.c
@@ -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;
 	}