-/*-
- * Copyright (c) 1990 The Regents of the University of California.
+/*
+ * Copyright (c) 1993 Winning Strategies, Inc.
* 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:
* 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
- 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
+
+ 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