diff options
Diffstat (limited to 'lib/libc/i386/string/strncmp.S')
| -rw-r--r-- | lib/libc/i386/string/strncmp.S | 172 |
1 files changed, 0 insertions, 172 deletions
diff --git a/lib/libc/i386/string/strncmp.S b/lib/libc/i386/string/strncmp.S deleted file mode 100644 index 0efc6ac..0000000 --- a/lib/libc/i386/string/strncmp.S +++ /dev/null @@ -1,172 +0,0 @@ -/* - * Copyright (c) 1993,94 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. - * - * $FreeBSD$ - */ - -#if defined(LIBC_RCS) && !defined(lint) - .text - .asciz "$FreeBSD$" -#endif /* LIBC_RCS and not lint */ - -#include "DEFS.h" - -/* - * strncmp(s1, s2, n) - * return an integer greater than, equal to, or less than 0, - * according as the first n characters of string s1 is greater - * than, equal to, or less than the string s2. - * - * %eax - pointer to s1 - * %ecx - pointer to s2 - * %edx - length - * - * 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. - * - * TODO: change all the jz's back to je for consistency. - */ - -ENTRY(strncmp) - pushl %ebx - movl 8(%esp),%eax - movl 12(%esp),%ecx - movl 16(%esp),%edx - testl %edx,%edx - jmp L2 /* Jump into the loop! */ - - .align 2,0x90 -L1: incl %eax - incl %ecx - decl %edx -L2: jz L4 /* strings are equal */ - movb (%eax),%bl - testb %bl,%bl - jz L3 - cmpb %bl,(%ecx) - jne L3 - -/* - * XXX it might be best to move the next 4 instructions to the end of the - * unrolled part of the loop. The unrolled part would then be - * movb n(%eax),%bl; testb %bl, %bl; je L3; cmpb n(%ecx); jne L3 - * or maybe better - * movb n(%eax),%bl; cmpb n(%ecx); jne L3; testb %bl,%bl; je return_0 - * for n = 0, 1, ..., 8. The end of the loop would be - * L1: addl $8,%eax; addl $8,%ecx; subl $8,%edx; cmpl $8,%edx; jae Lx - * where residual counts of 0 to 7 are handled at Lx. However, this would - * be slower for short strings. Cache effects are probably not so - * important because we are only handling a byte at a time. - */ - incl %eax - incl %ecx - decl %edx - jz L4 - movb (%eax),%bl - testb %bl,%bl - jz L3 - cmpb %bl,(%ecx) - jne L3 - - incl %eax - incl %ecx - decl %edx - jz L4 - movb (%eax),%bl - testb %bl,%bl - jz L3 - cmpb %bl,(%ecx) - jne L3 - - incl %eax - incl %ecx - decl %edx - jz L4 - movb (%eax),%bl - testb %bl,%bl - jz L3 - cmpb %bl,(%ecx) - jne L3 - - incl %eax - incl %ecx - decl %edx - jz L4 - movb (%eax),%bl - testb %bl,%bl - jz L3 - cmpb %bl,(%ecx) - jne L3 - - incl %eax - incl %ecx - decl %edx - jz L4 - movb (%eax),%bl - testb %bl,%bl - jz L3 - cmpb %bl,(%ecx) - jne L3 - - incl %eax - incl %ecx - decl %edx - jz L4 - movb (%eax),%bl - testb %bl,%bl - jz L3 - cmpb %bl,(%ecx) - jne L3 - - incl %eax - incl %ecx - decl %edx - jz L4 - movb (%eax),%bl - testb %bl,%bl - jz L3 - cmpb %bl,(%ecx) - je L1 - - .align 2,0x90 -L3: movzbl (%eax),%eax /* unsigned comparison */ - movzbl (%ecx),%ecx - subl %ecx,%eax - popl %ebx - ret - .align 2,0x90 -L4: xorl %eax,%eax - popl %ebx - ret |
