Author: fredrik.lundh
Date: Mon May 22 19:12:58 2006
New Revision: 46079
Modified:
python/trunk/Include/unicodeobject.h
python/trunk/Objects/unicodeobject.c
Log:
needforspeed: use memcpy for "long" strings; use a better algorithm
for long repeats.
Modified: python/trunk/Include/unicodeobject.h
==============================================================================
--- python/trunk/Include/unicodeobject.h (original)
+++ python/trunk/Include/unicodeobject.h Mon May 22 19:12:58 2006
@@ -352,14 +352,19 @@
Py_UNICODE_ISDIGIT(ch) || \
Py_UNICODE_ISNUMERIC(ch))
+/* memcpy has a considerable setup overhead on many platforms; use a
+ loop for short strings (the "16" below is pretty arbitary) */
#define Py_UNICODE_COPY(target, source, length) do\
- {int i; Py_UNICODE *t = (target); const Py_UNICODE *s = (source);\
- for (i = 0; i < (length); i++) t[i] = s[i];\
+ {Py_ssize_t i_; Py_UNICODE *t_ = (target); const Py_UNICODE *s_ = (source);\
+ if (length > 16)\
+ memcpy(t_, s_, (length)*sizeof(Py_UNICODE));\
+ else\
+ for (i_ = 0; i_ < (length); i_++) t_[i_] = s_[i_];\
} while (0)
#define Py_UNICODE_FILL(target, value, length) do\
- {int i; Py_UNICODE *t = (target); Py_UNICODE v = (value);\
- for (i = 0; i < (length); i++) t[i] = v;\
+ {Py_ssize_t i_; Py_UNICODE *t_ = (target); Py_UNICODE v_ = (value);\
+ for (i_ = 0; i_ < (length); i_++) t_[i_] = v_;\
} while (0)
#define Py_UNICODE_MATCH(string, offset, substring)\
Modified: python/trunk/Objects/unicodeobject.c
==============================================================================
--- python/trunk/Objects/unicodeobject.c (original)
+++ python/trunk/Objects/unicodeobject.c Mon May 22 19:12:58 2006
@@ -5900,11 +5900,18 @@
if (str->length == 1 && len > 0) {
Py_UNICODE_FILL(p, str->str[0], len);
- } else
- while (len-- > 0) {
+ } else {
+ int done = 0; /* number of characters copied this far */
+ if (done < nchars) {
Py_UNICODE_COPY(p, str->str, str->length);
- p += str->length;
- }
+ done = str->length;
+ }
+ while (done < nchars) {
+ int n = (done <= nchars-done) ? done : nchars-done;
+ Py_UNICODE_COPY(p+done, p, n);
+ done += n;
+ }
+ }
return (PyObject*) u;
}