1/*
2 * Copyright (C) 2008 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#include <private/bionic_asm.h>
30
31/*
32 * This code assumes it is running on a processor that supports all arm v7
33 * instructions, that supports neon instructions, and that supports
34 * unaligned neon instruction accesses to memory.
35 */
36
37    .fpu    neon
38    .syntax unified
39
40ENTRY(__memset_chk_krait)
41        cmp         r2, r3
42        bls         memset
43
44        // Preserve lr for backtrace.
45        push        {lr}
46        .cfi_def_cfa_offset 4
47        .cfi_rel_offset lr, 0
48
49        bl          __memset_chk_fail
50END(__memset_chk_krait)
51
52/* memset() returns its first argument.  */
53ENTRY(memset_krait)
54        mov         r3, r0
55        vdup.8      q0, r1
56
57        /* make sure we have at least 32 bytes to write */
58        subs        r2, r2, #32
59        blo         2f
60        vmov        q1, q0
61
621:      /* The main loop writes 32 bytes at a time */
63        subs        r2, r2, #32
64        vst1.8      {d0 - d3}, [r3]!
65        bhs         1b
66
672:      /* less than 32 left */
68        add         r2, r2, #32
69        tst         r2, #0x10
70        beq         3f
71
72        // writes 16 bytes, 128-bits aligned
73        vst1.8      {d0, d1}, [r3]!
743:      /* write up to 15-bytes (count in r2) */
75        movs        ip, r2, lsl #29
76        bcc         1f
77        vst1.8      {d0}, [r3]!
781:      bge         2f
79        vst1.32     {d0[0]}, [r3]!
802:      movs        ip, r2, lsl #31
81        strbmi      r1, [r3], #1
82        strbcs      r1, [r3], #1
83        strbcs      r1, [r3], #1
84        bx          lr
85END(memset_krait)
86