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 pDst a0
59#define pSrc a1
60#define iLength a2
61#define pDstPtr a3
62
63#define iVL a4
64#define iCurrentVL a5
65#define iActiveElemPos a6
66
67#define ELEM_LMUL_SETTING m1
68#define vMask1 v0
69#define vMask2 v1
70#define vStr1 v8
71#define vStr2 v16
72
73ENTRY(strncat_v)
74
75    mv pDstPtr, pDst
76
77    // the strlen of dst
78L(strlen_loop):
79    vsetvli iVL, zero, e8, ELEM_LMUL_SETTING, ta, ma
80
81    vle8ff.v vStr1, (pDstPtr)
82    // find the '\0'
83    vmseq.vx vMask1, vStr1, zero
84    csrr iCurrentVL, vl
85    vfirst.m iActiveElemPos, vMask1
86    add pDstPtr, pDstPtr, iCurrentVL
87    bltz iActiveElemPos, L(strlen_loop)
88
89    sub pDstPtr, pDstPtr, iCurrentVL
90    add pDstPtr, pDstPtr, iActiveElemPos
91
92    // copy pSrc to pDstPtr
93L(strcpy_loop):
94    vsetvli iVL, iLength, e8, ELEM_LMUL_SETTING, ta, ma
95
96    vle8ff.v vStr1, (pSrc)
97    vmseq.vx vMask2, vStr1, zero
98    csrr iCurrentVL, vl
99    vfirst.m iActiveElemPos, vMask2
100    vmsif.m vMask1, vMask2
101    add pSrc, pSrc, iCurrentVL
102    sub iLength, iLength, iCurrentVL
103    vse8.v vStr1, (pDstPtr), vMask1.t
104    add pDstPtr, pDstPtr, iCurrentVL
105    beqz iLength, L(fill_zero)
106    bltz iActiveElemPos, L(strcpy_loop)
107
108    ret
109
110L(fill_zero):
111    bgez iActiveElemPos, L(fill_zero_end)
112    sb zero, (pDstPtr)
113
114L(fill_zero_end):
115    ret
116
117END(strncat_v)
118