improved the speed somewhat

fixed bug with negative chars in comparisons

lang/cem/libcc.ansi/string/memmove.c

@@ -12,18 +12,21 @@ memmove(void *s1, const void *s2, register size_t n)
 	register char *p1 = s1;
 	register const char *p2 = s2;
 
-	if (p2 <= p1 && p2 + (n-1) >= p1) {
-		/* overlap, copy backwards */
-		p1 += n;
-		p2 += n;
-		while (n > 0) {
-			n--;
-			*--p1 = *--p2;
-		}
-	} else
-		while (n > 0) {
-			n--;
-			*p1++ = *p2++;
+	if (n>0) {
+		if (p2 <= p1 && p2 + n > p1) {
+			/* overlap, copy backwards */
+			p1 += n;
+			p2 += n;
+			n++;
+			while (--n > 0) {
+				*--p1 = *--p2;
+			}
+		} else {
+			n++;
+			while (--n > 0) {
+				*p1++ = *p2++;
+			}
 		}
+	}
 	return s1;
 }