1/*      $NetBSD: strncmp.S,v 1.2 2013/08/19 00:57:25 matt Exp $ */
2
3/*
4 * Copyright (c) 2002 ARM Ltd
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. The name of the company may not be used to endorse or promote
16 *    products derived from this software without specific prior written
17 *    permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY ARM LTD ``AS IS'' AND ANY EXPRESS OR IMPLIED
20 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL ARM LTD BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
24 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
25 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
26 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
27 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
28 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <machine/asm.h>
32
33RCSID("$NetBSD: strncmp.S,v 1.2 2013/08/19 00:57:25 matt Exp $")
34
35ENTRY(strncmp)
36/* if ((len - 1) < 0) return 0 */
37          subs      r2, r2, #1
38#ifdef __thumb__
39          bmi       5f
40#else
41          movmi     r0, #0
42          RETc(mi)
43#endif
44
45/* ip == last src address to compare */
46#ifdef __thumb__
47          adds      r3, r0, r2
48          mov       ip, r3
49          subs      r1, r1, r0
50#else
51          add       ip, r0, r2
52#endif
531:
54#ifdef __thumb__
55          ldrb      r2, [r0]
56          ldrb      r3, [r1, r0]
57          adds      r0, r0, #1
58          cmp       ip, r0              /* exhausted length? */
59          bcc       4f                  /*   yes, we're done */
60          cmp       r2, #1              /* NUL? */
61          bcc       4f                  /*   yes, we're done */
62          cmp       r2, r3              /* different? */
63#else
64          ldrb      r2, [r0], #1
65          ldrb      r3, [r1], #1
66          cmp       ip, r0
67          cmpcs     r2, #1
68          cmpcs     r2, r3
69#endif
70          beq       1b
714:        subs      r0, r2, r3
72          RET
73#ifdef __thumb__
745:        movs      r0, #0
75          RET
76#endif
77END(strncmp)
78