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Optimize inner loops for subscript, repeat, and concat.

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This commit is contained in:
Raymond Hettinger 2004-03-09 13:05:22 +00:00
parent f889e10c19
commit a6366fe085
2 changed files with 59 additions and 36 deletions
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66
Objects/listobject.c
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@ -382,6 +382,7 @@ list_concat(PyListObject *a, PyObject *bb)
{
int size;
int i;
PyObject **src, **dest;
PyListObject *np;
if (!PyList_Check(bb)) {
PyErr_Format(PyExc_TypeError,
@ -397,15 +398,19 @@ list_concat(PyListObject *a, PyObject *bb)
if (np == NULL) {
return NULL;
}
src = a->ob_item;
dest = np->ob_item;
for (i = 0; i < a->ob_size; i++) {
PyObject *v = a->ob_item[i];
PyObject *v = src[i];
Py_INCREF(v);
np->ob_item[i] = v;
dest[i] = v;
}
src = b->ob_item;
dest = np->ob_item + a->ob_size;
for (i = 0; i < b->ob_size; i++) {
PyObject *v = b->ob_item[i];
PyObject *v = src[i];
Py_INCREF(v);
np->ob_item[i + a->ob_size] = v;
dest[i] = v;
}
return (PyObject *)np;
#undef b
@ -417,7 +422,7 @@ list_repeat(PyListObject *a, int n)
int i, j;
int size;
PyListObject *np;
PyObject **p;
PyObject **p, **items;
PyObject *elem;
if (n < 0)
n = 0;
@ -430,18 +435,20 @@ list_repeat(PyListObject *a, int n)
if (np == NULL)
return NULL;
items = np->ob_item;
if (a->ob_size == 1) {
elem = a->ob_item[0];
for (i = 0; i < n; i++) {
np->ob_item[i] = elem;
items[i] = elem;
Py_INCREF(elem);
}
return (PyObject *) np;
}
p = np->ob_item;
items = a->ob_item;
for (i = 0; i < n; i++) {
for (j = 0; j < a->ob_size; j++) {
*p = a->ob_item[j];
*p = items[j];
Py_INCREF(*p);
p++;
}
@ -590,11 +597,12 @@ list_inplace_repeat(PyListObject *self, int n)
return NULL;
p = size;
items = self->ob_item;
for (i = 1; i < n; i++) { /* Start counting at 1, not 0 */
for (j = 0; j < size; j++) {
PyObject *o = PyList_GET_ITEM(self, j);
PyObject *o = items[j];
Py_INCREF(o);
PyList_SET_ITEM(self, p++, o);
items[p++] = o;
}
}
Py_INCREF(self);
@ -2404,6 +2412,7 @@ list_subscript(PyListObject* self, PyObject* item)
int start, stop, step, slicelength, cur, i;
PyObject* result;
PyObject* it;
PyObject **src, **dest;
if (PySlice_GetIndicesEx((PySliceObject*)item, self->ob_size,
&start, &stop, &step, &slicelength) < 0) {
@ -2417,11 +2426,13 @@ list_subscript(PyListObject* self, PyObject* item)
result = PyList_New(slicelength);
if (!result) return NULL;
src = self->ob_item;
dest = ((PyListObject *)result)->ob_item;
for (cur = start, i = 0; i < slicelength;
cur += step, i++) {
it = PyList_GET_ITEM(self, cur);
it = src[cur];
Py_INCREF(it);
PyList_SET_ITEM(result, i, it);
dest[i] = it;
}
return result;
@ -2466,7 +2477,7 @@ list_ass_subscript(PyListObject* self, PyObject* item, PyObject* value)
if (value == NULL) {
/* delete slice */
PyObject **garbage;
int cur, i, j;
int cur, i;
if (slicelength <= 0)
return 0;
@ -2493,17 +2504,17 @@ list_ass_subscript(PyListObject* self, PyObject* item, PyObject* value)
lim = self->ob_size - cur - 1;
}
for (j = 0; j < lim; j++) {
PyList_SET_ITEM(self, cur + j - i,
PyList_GET_ITEM(self,
cur + j + 1));
}
memmove(self->ob_item + cur - i,
self->ob_item + cur + 1,
lim * sizeof(PyObject *));
}
for (cur = start + slicelength*step + 1;
cur < self->ob_size; cur++) {
PyList_SET_ITEM(self, cur - slicelength,
PyList_GET_ITEM(self, cur));
}
self->ob_size -= slicelength;
list_resize(self, self->ob_size);
@ -2516,7 +2527,7 @@ list_ass_subscript(PyListObject* self, PyObject* item, PyObject* value)
}
else {
/* assign slice */
PyObject **garbage, *ins, *seq;
PyObject **garbage, *ins, *seq, **seqitems, **selfitems;
int cur, i;
/* protect against a[::-1] = a */
@ -2525,11 +2536,8 @@ list_ass_subscript(PyListObject* self, PyObject* item, PyObject* value)
PyList_GET_SIZE(value));
}
else {
char msg[256];
PyOS_snprintf(msg, sizeof(msg),
"must assign sequence (not \"%.200s\") to extended slice",
value->ob_type->tp_name);
seq = PySequence_Fast(value, msg);
seq = PySequence_Fast(value,
"must assign iterable to extended slice");
if (!seq)
return -1;
}
@ -2551,13 +2559,17 @@ list_ass_subscript(PyListObject* self, PyObject* item, PyObject* value)
garbage = (PyObject**)
PyMem_MALLOC(slicelength*sizeof(PyObject*));
selfitems = self->ob_item;
if (PyList_Check(seq))
seqitems = ((PyListObject *)seq)->ob_item;
else
seqitems = ((PyTupleObject *)seq)->ob_item;
for (cur = start, i = 0; i < slicelength;
cur += step, i++) {
garbage[i] = PyList_GET_ITEM(self, cur);
ins = PySequence_Fast_GET_ITEM(seq, i);
garbage[i] = selfitems[cur];
ins = seqitems[i];
Py_INCREF(ins);
PyList_SET_ITEM(self, cur, ins);
selfitems[cur] = ins;
}
for (i = 0; i < slicelength; i++) {