| Message ID | 000001cfbc74$6dbf1020$493d3060$@com |
|---|---|
| State | New |
| Headers | show |
From what is worth, this is similar optimization I pushed for powerpc (which some more arch-specific tunings) and looks ok. PS: try to send patch as inline instead of attachments. On 20-08-2014 09:44, Wilco Dijkstra wrote: > Hi, > > This patch improves strncat performance by using strlen. Strlen has a fast C implementation, so this > will improve performance even on targets which don't have an optimized strlen. It is about twice as > fast as the original strncat in bench-strncat. > > ChangeLog: > 2014-08-20 Wilco Dijkstra <wdijkstr@arm.com> > > * string/strncat.c (strncat): Improve performance by using strlen. > --- > string/strncat.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/string/strncat.c b/string/strncat.c > index 7ac4456..6d29114 100644 > --- a/string/strncat.c > +++ b > @@ -33,13 +33,11 @@ STRNCAT (char *s1, const char *s2, size_t n) > char *s = s1; > > /* Find the end of S1. */ > - do > - c = *s1++; > - while (c != '\0'); > + s1 += strlen (s1); > > /* Make S1 point before next character, so we can increment > it while memory is read (wins on pipelined cpus). */ > - s1 -= 2; > + s1 -= 1; > > if (n >= 4) > { > -- 1.7.9.5
diff --git a/string/strncat.c b/string/strncat.c index 7ac4456..6d29114 100644 --- a/string/strncat.c +++ b/string/strncat.c @@ -33,13 +33,11 @@ STRNCAT (char *s1, const char *s2, size_t n) char *s = s1; /* Find the end of S1. */ - do - c = *s1++; - while (c != '\0'); + s1 += strlen (s1); /* Make S1 point before next character, so we can increment it while memory is read (wins on pipelined cpus). */ - s1 -= 2; + s1 -= 1; if (n >= 4) {