diff options
Diffstat (limited to 'lib/libc/i386/string/strcpy.S')
-rw-r--r-- | lib/libc/i386/string/strcpy.S | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/lib/libc/i386/string/strcpy.S b/lib/libc/i386/string/strcpy.S new file mode 100644 index 0000000..a474ec1 --- /dev/null +++ b/lib/libc/i386/string/strcpy.S @@ -0,0 +1,89 @@ +/* + * 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 without 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. + */ + +#include <machine/asm.h> +__FBSDID("$FreeBSD$"); + +/* + * strcpy (dst, src) + * copy the string src to dst. + * + * 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 + * cache. + */ + +ENTRY(strcpy) + movl 4(%esp),%ecx /* dst address */ + movl 8(%esp),%edx /* src address */ + pushl %ecx /* push 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 dst address */ + ret |