This commit was manufactured by cvs2svn to create tag 'FreeBSD-release/1.0'.

[unix-history] / lib / libc / i386 / string / bzero.s

diff --git a/lib/libc/i386/string/bzero.s b/lib/libc/i386/string/bzero.s
index d876e69..9881d30 100644 (file)
--- a/lib/libc/i386/string/bzero.s
+++ b/lib/libc/i386/string/bzero.s
@@ -1,10 +1,7 @@
-/*-
- * Copyright (c) 1990 The Regents of the University of California.
+/*
+ * Copyright (c) 1993 Winning Strategies, Inc.

  * All rights reserved.
  *
  * All rights reserved.
  *

- * This code is derived from software contributed to Berkeley by
- * William Jolitz.
- *

  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:


@@ -15,39 +12,75 @@
  *    documentation and/or other materials provided with the distribution.
  * 3. All advertising materials mentioning features or use of this software
  *    must display the following acknowledgement:
  *    documentation and/or other materials provided with the distribution.
  * 3. All advertising materials mentioning features or use of this software
  *    must display the following acknowledgement:

- *     This product includes software developed by the University of
- *     California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
- *    may be used to endorse or promote products derived from this software
- *    without specific prior written permission.
+ *      This product includes software developed by Winning Strategies, Inc.
+ * 4. The name of the author may not be used to endorse or promote products
+ *    derived from this software withough specific prior written permission
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

  *
  *

- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
+ *     $Id: bzero.s,v 1.6 1993/08/16 17:06:29 jtc Exp $

  */
 
  */
 

-#if defined(LIBC_SCCS) && !defined(lint)
-       .asciz "@(#)bzero.s     5.1 (Berkeley) 4/23/90"
-#endif /* LIBC_SCCS and not lint */
+#if defined(LIBC_RCS) && !defined(lint)
+        .asciz "$Id: bzero.s,v 1.6 1993/08/16 17:06:29 jtc Exp $"
+#endif /* LIBC_RCS and not lint */

 
 

-/* bzero (base,cnt) */
+#include "DEFS.h"

 
 

-       .globl _bzero
-_bzero:
+/*
+ * bzero (void *b, size_t len)
+ *     write len zero bytes to the string b.
+ *
+ * Written by:
+ *     J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc.
+ */
+
+ENTRY(bzero)

        pushl   %edi
        pushl   %edi

-       movl    8(%esp),%edi
-       movl    12(%esp),%ecx
-       movb    $0x00,%al
-       cld
+       pushl   %ebx
+       movl    12(%esp),%edi
+       movl    16(%esp),%ecx
+
+       cld                             /* set fill direction forward */
+       xorl    %eax,%eax               /* set fill data to 0 */
+
+       /*
+        * if the string is too short, it's really not worth the overhead
+        * of aligning to word boundries, etc.  So we jump to a plain 
+        * unaligned set.
+        */
+       cmpl    $0x0f,%ecx
+       jle     L1
+
+       movl    %edi,%edx               /* compute misalignment */
+       negl    %edx
+       andl    $3,%edx
+       movl    %ecx,%ebx
+       subl    %edx,%ebx
+
+       movl    %edx,%ecx               /* zero until word aligned */

        rep
        stosb
        rep
        stosb

+
+       movl    %ebx,%ecx               /* zero by words */
+       shrl    $2,%ecx
+       rep
+       stosl
+
+       movl    %ebx,%ecx
+       andl    $3,%ecx                 /* zero remainder by bytes */
+L1:    rep
+       stosb
+
+       popl    %ebx

        popl    %edi
        ret
        popl    %edi
        ret