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Subjectstrncpy optimalisation? (lib/string.c)
Hi,

In lib/string.c we have:

char *strncpy(char *dest, const char *src, size_t count)
{
char *tmp = dest;
while (count) {
if ((*tmp = *src) != 0)
src++;
tmp++;
count--;
}
return dest;
}
now I wonder isn't this ineffecient when strlen(src) < count? It would
then, if I'm correct, iterate count-strlen(src) times doing useless
increment/decrement. And since there are aprox. 580 instances in the
2.6.18.2 source, maybe some efficency can be won here.
Wouldn't it be better to do:
if ((*tmp = *src) == 0x00)
break;
So that would be:
--- lib/string.c 2006-11-04 02:33:58.000000000 +0100
+++ string-new.c 2006-12-10 21:50:05.000000000 +0100
@@ -97,8 +97,8 @@
char *tmp = dest;

while (count) {
- if ((*tmp = *src) != 0)
- src++;
+ if ((*tmp = *src) == 0x00)
+ break;
tmp++;
count--;
}

Folkert van Heusden

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