alf: Speed up match_token() slightly. Still too slow.

1 files changed, 6 insertions, 4 deletions

diff --git a/src/alf.c b/src/alf.c
index 1d634ab..f3c4e0c 100644
--- a/src/alf.c
+++ b/src/alf.c
@@ -239,13 +239,15 @@ int match_token(int pos) {
 
 		/* inline memcmp replacement of sorts. I don't think it's really
 		   faster than memcmp(), it only seems that way because there's
-		   no function call overhead. ~20% speedup. */
+		   no function call overhead. ~20% speedup.
+		   making it search backwards gives a further ~25% speedup.
+		 */
 		len = t->length;
-		p = &input_buf[pos];
-		q = t->start;
+		p = &input_buf[pos] + len - 1;
+		q = t->start + len - 1;
 		while(len) {
 			if(*p != *q) break;
-			p++; q++;
+			p--; q--;
 			len--;
 		}
 		if(!len) return i;