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-rw-r--r--lib/libc/i386/string/strcat.S105
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diff --git a/lib/libc/i386/string/strcat.S b/lib/libc/i386/string/strcat.S
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+/*
+ * Copyright (c) 1993 Winning Strategies, Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * 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 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.
+ *
+ * $Id: strcat.S,v 1.1 1993/12/05 13:01:56 ats Exp $
+ */
+
+#if defined(LIBC_RCS) && !defined(lint)
+ .asciz "$Id: strcat.S,v 1.1 1993/12/05 13:01:56 ats Exp $"
+#endif /* LIBC_RCS and not lint */
+
+#include "DEFS.h"
+
+/*
+ * strcat(s, append)
+ * append a copy of the null-terminated string "append" to the end
+ * of the null-terminated string s, then add a terminating `\0'.
+ *
+ * Written by:
+ * J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc.
+ */
+
+/*
+ * I've unrolled the loop eight times: large enough to make a
+ * significant difference, and small enough not to totally trash the
+ * cashe.
+ */
+
+ENTRY(strcat)
+ pushl %edi /* save edi */
+ movl 8(%esp),%edi /* dst address */
+ movl 12(%esp),%edx /* src address */
+ pushl %edi /* push destination address */
+
+ cld /* set search forward */
+ xorl %eax,%eax /* set search for null terminator */
+ movl $-1,%ecx /* set search for lots of characters */
+ repne /* search! */
+ scasb
+
+ leal -1(%edi),%ecx /* correct dst address */
+
+ .align 2,0x90
+L1: movb (%edx),%al /* unroll loop, but not too much */
+ movb %al,(%ecx)
+ testb %al,%al
+ je L2
+ movb 1(%edx),%al
+ movb %al,1(%ecx)
+ testb %al,%al
+ je L2
+ movb 2(%edx),%al
+ movb %al,2(%ecx)
+ testb %al,%al
+ je L2
+ movb 3(%edx),%al
+ movb %al,3(%ecx)
+ testb %al,%al
+ je L2
+ movb 4(%edx),%al
+ movb %al,4(%ecx)
+ testb %al,%al
+ je L2
+ movb 5(%edx),%al
+ movb %al,5(%ecx)
+ testb %al,%al
+ je L2
+ movb 6(%edx),%al
+ movb %al,6(%ecx)
+ testb %al,%al
+ je L2
+ movb 7(%edx),%al
+ movb %al,7(%ecx)
+ addl $8,%edx
+ addl $8,%ecx
+ testb %al,%al
+ jne L1
+L2: popl %eax /* pop destination address */
+ popl %edi /* restore edi */
+ ret
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