1/*
2 * Copyright (C) 2023 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *  * Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *  * Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in
12 *    the documentation and/or other materials provided with the
13 *    distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28/*
29 * Copyright (c) 2023 SiFive, Inc.
30 * All rights reserved.
31 *
32 * Redistribution and use in source and binary forms, with or without
33 * modification, are permitted provided that the following conditions
34 * are met:
35 * 1. Redistributions of source code must retain the above copyright
36 *    notice, this list of conditions and the following disclaimer.
37 * 2. Redistributions in binary form must reproduce the above copyright
38 *    notice, this list of conditions and the following disclaimer in the
39 *    documentation and/or other materials provided with the distribution.
40 * 3. The name of the company may not be used to endorse or promote
41 *    products derived from this software without specific prior written
42 *    permission.
43 *
44 * THIS SOFTWARE IS PROVIDED BY SIFIVE INC ``AS IS'' AND ANY EXPRESS OR IMPLIED
45 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
46 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
47 * IN NO EVENT SHALL SIFIVE INC BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
48 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
49 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
50 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
51 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
52 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
53 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
54 */
55
56#include <private/bionic_asm.h>
57
58#define pStr a0
59#define pCopyStr a2
60#define iRetValue a0
61#define iMaxlen a1
62#define iCurrentVL a3
63#define iEndOffset a4
64
65#define ELEM_LMUL_SETTING m1
66#define vStr v0
67#define vMaskEnd v8
68
69ENTRY(strnlen_v)
70
71    mv pCopyStr, pStr
72    mv iRetValue, iMaxlen
73L(strnlen_loop):
74    beqz iMaxlen, L(end_strnlen_loop)
75    vsetvli zero, iMaxlen, e8, ELEM_LMUL_SETTING, ta, ma
76    vle8ff.v vStr, (pCopyStr)
77    vmseq.vi vMaskEnd, vStr, 0
78    vfirst.m iEndOffset, vMaskEnd /* first occurrence of \0 */
79    csrr iCurrentVL, vl
80    add pCopyStr, pCopyStr, iCurrentVL
81    sub iMaxlen, iMaxlen, iCurrentVL
82    bltz iEndOffset, L(strnlen_loop)
83    add iMaxlen, iMaxlen, iCurrentVL
84    sub iRetValue, iRetValue, iMaxlen
85    add iRetValue, iRetValue, iEndOffset
86L(end_strnlen_loop):
87    ret
88
89END(strnlen_v)
90