mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-08-30 21:48:47 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 7

Several optimizations and speed improvements.

Browse source 
cstubs: Use Matrix type instead of float[4][4].
This commit is contained in:
Sjoerd Mullender 1993-10-22 12:04:32 +00:00
parent a75d306e2b
commit 3bb8a05947
10 changed files with 216 additions and 63 deletions
Download patch file Download diff file Expand all files Collapse all files

136
Objects/stringobject.c
View file

@ -26,21 +26,76 @@ OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
#include "allobjects.h"
#ifdef COUNT_ALLOCS
int null_strings, one_strings;
#endif
#ifdef __STDC__
#include <limits.h>
#else
#ifndef UCHAR_MAX
#define UCHAR_MAX 255
#endif
#endif
static stringobject *characters[UCHAR_MAX + 1];
static stringobject *nullstring;
/*
Newsizedstringobject() and newstringobject() try in certain cases
to share string objects. When the size of the string is zero,
these routines always return a pointer to the same string object;
when the size is one, they return a pointer to an already existing
object if the contents of the string is known. For
newstringobject() this is always the case, for
newsizedstringobject() this is the case when the first argument in
not NULL.
A common practice to allocate a string and then fill it in or
change it must be done carefully. It is only allowed to change the
contents of the string if the obect was gotten from
newsizedstringobject() with a NULL first argument, because in the
future these routines may try to do even more sharing of objects.
*/
object *
newsizedstringobject(str, size)
char *str;
int size;
{
register stringobject *op = (stringobject *)
register stringobject *op;
if (size == 0 && (op = nullstring) != NULL) {
#ifdef COUNT_ALLOCS
null_strings++;
#endif
INCREF(op);
return op;
}
if (size == 1 && str != NULL && (op = characters[*str & UCHAR_MAX]) != NULL) {
#ifdef COUNT_ALLOCS
one_strings++;
#endif
INCREF(op);
return op;
}
op = (stringobject *)
malloc(sizeof(stringobject) + size * sizeof(char));
if (op == NULL)
return err_nomem();
op->ob_type = &Stringtype;
op->ob_size = size;
#ifdef CACHE_HASH
op->ob_shash = -1;
#endif
NEWREF(op);
if (str != NULL)
memcpy(op->ob_sval, str, size);
op->ob_sval[size] = '\0';
if (size == 0) {
nullstring = op;
INCREF(op);
} else if (size == 1 && str != NULL) {
characters[*str & UCHAR_MAX] = op;
INCREF(op);
}
return (object *) op;
}
@ -49,14 +104,39 @@ newstringobject(str)
char *str;
{
register unsigned int size = strlen(str);
register stringobject *op = (stringobject *)
register stringobject *op;
if (size == 0 && (op = nullstring) != NULL) {
#ifdef COUNT_ALLOCS
null_strings++;
#endif
INCREF(op);
return op;
}
if (size == 1 && (op = characters[*str & UCHAR_MAX]) != NULL) {
#ifdef COUNT_ALLOCS
one_strings++;
#endif
INCREF(op);
return op;
}
op = (stringobject *)
malloc(sizeof(stringobject) + size * sizeof(char));
if (op == NULL)
return err_nomem();
op->ob_type = &Stringtype;
op->ob_size = size;
#ifdef CACHE_HASH
op->ob_shash = -1;
#endif
NEWREF(op);
strcpy(op->ob_sval, str);
if (size == 0) {
nullstring = op;
INCREF(op);
} else if (size == 1) {
characters[*str & UCHAR_MAX] = op;
INCREF(op);
}
return (object *) op;
}
@ -189,6 +269,9 @@ string_concat(a, bb)
return err_nomem();
op->ob_type = &Stringtype;
op->ob_size = size;
#ifdef CACHE_HASH
op->ob_shash = -1;
#endif
NEWREF(op);
memcpy(op->ob_sval, a->ob_sval, (int) a->ob_size);
memcpy(op->ob_sval + a->ob_size, b->ob_sval, (int) b->ob_size);
@ -218,6 +301,9 @@ string_repeat(a, n)
return err_nomem();
op->ob_type = &Stringtype;
op->ob_size = size;
#ifdef CACHE_HASH
op->ob_shash = -1;
#endif
NEWREF(op);
for (i = 0; i < size; i += a->ob_size)
memcpy(op->ob_sval+i, a->ob_sval, (int) a->ob_size);
@ -247,16 +333,6 @@ string_slice(a, i, j)
return newsizedstringobject(a->ob_sval + i, (int) (j-i));
}
#ifdef __STDC__
#include <limits.h>
#else
#ifndef UCHAR_MAX
#define UCHAR_MAX 255
#endif
#endif
static object *characters[UCHAR_MAX + 1];
static object *
string_item(a, i)
stringobject *a;
@ -269,12 +345,16 @@ string_item(a, i)
return NULL;
}
c = a->ob_sval[i] & UCHAR_MAX;
v = characters[c];
v = (object *) characters[c];
#ifdef COUNT_ALLOCS
if (v != NULL)
one_strings++;
#endif
if (v == NULL) {
v = newsizedstringobject((char *)NULL, 1);
if (v == NULL)
return NULL;
characters[c] = v;
characters[c] = (stringobject *) v;
((stringobject *)v)->ob_sval[0] = c;
}
INCREF(v);
@ -287,9 +367,14 @@ string_compare(a, b)
{
int len_a = a->ob_size, len_b = b->ob_size;
int min_len = (len_a < len_b) ? len_a : len_b;
int cmp = memcmp(a->ob_sval, b->ob_sval, min_len);
if (cmp != 0)
return cmp;
int cmp;
if (min_len > 0) {
cmp = *a->ob_sval - *b->ob_sval;
if (cmp == 0)
cmp = memcmp(a->ob_sval, b->ob_sval, min_len);
if (cmp != 0)
return cmp;
}
return (len_a < len_b) ? -1 : (len_a > len_b) ? 1 : 0;
}
@ -297,14 +382,25 @@ static long
string_hash(a)
stringobject *a;
{
register int len = a->ob_size;
register unsigned char *p = (unsigned char *) a->ob_sval;
register long x = *p << 7;
register int len;
register unsigned char *p;
register long x;
#ifdef CACHE_HASH
if (a->ob_shash != -1)
return a->ob_shash;
#endif
len = a->ob_size;
p = (unsigned char *) a->ob_sval;
x = *p << 7;
while (--len >= 0)
x = (x + x + x) ^ *p++;
x ^= a->ob_size;
if (x == -1)
x = -2;
#ifdef CACHE_HASH
a->ob_shash = x;
#endif
return x;
}