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Don't use a newfangled auto initializer. Initialize everything by

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assignment to avoid one bug and several pessimizations.

In the old version, gcc-2.6.3 (i386 version) generates 16 bytes
of static data and copies it using 4 4-byte load-stores.  gcc-2.7.2
generates 2 1-byte stores and calls memset() to zero 14 bytes.
Linking fails because memset() doesn't exist in the kernel.

In both versions, the 2 bytes stored directly are all that is
actually used unless the null padding at the end is used, since
the 3 4-byte words in the middle are initialized again by struct
assignment.  These words are misaligned.  gcc generates misaligned
load-stores for (small) misaligned struct copies.

Submitted by:	Bruce Evans
This commit is contained in:
John Hay 1996-04-13 14:37:22 +00:00
parent c9b9c54d1f
commit 01a95d942e
1 changed files with 6 additions and 2 deletions
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8
sys/netipx/ipx_usrreq.c
View File

@ -33,7 +33,7 @@
*
* @(#)ipx_usrreq.c
*
* $Id: ipx_usrreq.c,v 1.4 1995/11/04 09:03:24 julian Exp $
* $Id: ipx_usrreq.c,v 1.5 1996/03/11 15:13:57 davidg Exp $
*/
#include <sys/param.h>
@ -75,7 +75,7 @@ ipx_input(m, ipxp)
{
register struct ipx *ipx = mtod(m, struct ipx *);
struct ifnet *ifp = m->m_pkthdr.rcvif;
struct sockaddr_ipx ipx_ipx = { sizeof(ipx_ipx), AF_IPX };
struct sockaddr_ipx ipx_ipx;
if (ipxp==0)
panic("No ipxpcb");
@ -83,7 +83,11 @@ ipx_input(m, ipxp)
* Construct sockaddr format source address.
* Stuff source address and datagram in user buffer.
*/
ipx_ipx.sipx_len = sizeof(ipx_ipx);
ipx_ipx.sipx_family = AF_IPX;
ipx_ipx.sipx_addr = ipx->ipx_sna;
ipx_ipx.sipx_zero[0] = '\0';
ipx_ipx.sipx_zero[1] = '\0';
if (ipx_neteqnn(ipx->ipx_sna.x_net, ipx_zeronet) && ifp) {
register struct ifaddr *ifa;