[src/trunk]: src/sbin/fsck_msdos PR/50908: David Binderman: Optimize memset's

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/379fa02596b1
branches:  trunk
changeset: 343968:379fa02596b1
user:      christos <christos%NetBSD.org@localhost>
date:      Mon Mar 07 14:47:25 2016 +0000

description:
PR/50908: David Binderman: Optimize memset's

diffstat:

 sbin/fsck_msdos/dir.c |  14 ++++++++------
 1 files changed, 8 insertions(+), 6 deletions(-)

diffs (46 lines):

diff -r 5b43606e4e7b -r 379fa02596b1 sbin/fsck_msdos/dir.c
--- a/sbin/fsck_msdos/dir.c     Mon Mar 07 14:35:39 2016 +0000
+++ b/sbin/fsck_msdos/dir.c     Mon Mar 07 14:47:25 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: dir.c,v 1.27 2015/01/02 06:21:28 mlelstv Exp $ */
+/*     $NetBSD: dir.c,v 1.28 2016/03/07 14:47:25 christos Exp $        */
 
 /*
  * Copyright (C) 1995, 1996, 1997 Wolfgang Solfrank
@@ -30,7 +30,7 @@
 
 #include <sys/cdefs.h>
 #ifndef lint
-__RCSID("$NetBSD: dir.c,v 1.27 2015/01/02 06:21:28 mlelstv Exp $");
+__RCSID("$NetBSD: dir.c,v 1.28 2016/03/07 14:47:25 christos Exp $");
 #endif /* not lint */
 
 #include <stdio.h>
@@ -929,6 +929,7 @@
 reconnect(int dosfs, struct bootblock *boot, struct fatEntry *fat, cl_t head)
 {
        struct dosDirEntry d;
+       int len;
        u_char *p;
 
        if (!ask(1, "Reconnect"))
@@ -980,14 +981,15 @@
        boot->NumFiles++;
        /* Ensure uniqueness of entry here!                             XXX */
        memset(&d, 0, sizeof d);
-       (void)snprintf(d.name, sizeof(d.name), "%u", head);
+       /* worst case -1 = 4294967295, 10 digits */
+       len = snprintf(d.name, sizeof(d.name), "%u", head);
        d.flags = 0;
        d.head = head;
        d.size = fat[head].length * boot->ClusterSize;
 
-       memset(p, 0, 32);
-       memset(p, ' ', 11);
-       memcpy(p, d.name, strlen(d.name));
+       memcpy(p, d.name, len);
+       memset(p + len, ' ', 11 - len);
+       memset(p + 11, 0, 32 - 11);
        p[26] = (u_char)d.head;
        p[27] = (u_char)(d.head >> 8);
        if (boot->ClustMask == CLUST32_MASK) {