1/***
2  This file is part of PulseAudio.
3
4  Copyright 2004-2006 Lennart Poettering
5  Copyright 2009 Wim Taymans <wim.taymans@collabora.co.uk>
6
7  PulseAudio is free software; you can redistribute it and/or modify
8  it under the terms of the GNU Lesser General Public License as published
9  by the Free Software Foundation; either version 2.1 of the License,
10  or (at your option) any later version.
11
12  PulseAudio is distributed in the hope that it will be useful, but
13  WITHOUT ANY WARRANTY; without even the implied warranty of
14  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  General Public License for more details.
16
17  You should have received a copy of the GNU Lesser General Public License
18  along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
19***/
20
21#ifdef HAVE_CONFIG_H
22#include <config.h>
23#endif
24
25#include <pulsecore/random.h>
26#include <pulsecore/macro.h>
27#include <pulsecore/endianmacros.h>
28
29#include "cpu-arm.h"
30
31#include "sample-util.h"
32
33#if defined (__arm__) && defined (HAVE_ARMV6)
34
35#define MOD_INC() \
36    " subs  r0, r6, %2              \n\t" \
37    " itt cs                        \n\t" \
38    " addcs r0, %1                  \n\t" \
39    " movcs r6, r0                  \n\t"
40
41static pa_do_volume_func_t _volume_ref;
42
43static void pa_volume_s16ne_arm(int16_t *samples, const int32_t *volumes, unsigned channels, unsigned length) {
44    /* Channels must be at least 4, and always a multiple of the original number.
45     * This is also the max amount we overread the volume array, which should
46     * have enough padding. */
47    const int32_t *ve = volumes + (channels == 3 ? 6 : PA_MAX (4U, channels));
48    unsigned rem = PA_ALIGN((size_t) samples) - (size_t) samples;
49
50    /* Make sure we're word-aligned, else performance _really_ sucks */
51    if (rem) {
52        _volume_ref(samples, volumes, channels, rem < length ? rem : length);
53
54        if (rem < length) {
55            length -= rem;
56            samples += rem / sizeof(*samples);
57        } else
58            return; /* we're done */
59    }
60
61    __asm__ __volatile__ (
62        " mov r6, %4                      \n\t" /* r6 = volumes + rem */
63        " mov %3, %3, LSR #1              \n\t" /* length /= sizeof (int16_t) */
64
65        " cmp %3, #4                      \n\t" /* check for 4+ samples */
66        " blt 2f                          \n\t"
67
68        /* See final case for how the multiplication works */
69
70        "1:                               \n\t"
71        " ldrd r2, [r6], #8               \n\t" /* 4 samples at a time */
72        " ldrd r4, [r6], #8               \n\t"
73        " ldrd r0, [%0]                   \n\t"
74
75#ifdef WORDS_BIGENDIAN
76        " smulwt r2, r2, r0               \n\t"
77        " smulwb r3, r3, r0               \n\t"
78        " smulwt r4, r4, r1               \n\t"
79        " smulwb r5, r5, r1               \n\t"
80#else
81        " smulwb r2, r2, r0               \n\t"
82        " smulwt r3, r3, r0               \n\t"
83        " smulwb r4, r4, r1               \n\t"
84        " smulwt r5, r5, r1               \n\t"
85#endif
86
87        " ssat r2, #16, r2                \n\t"
88        " ssat r3, #16, r3                \n\t"
89        " ssat r4, #16, r4                \n\t"
90        " ssat r5, #16, r5                \n\t"
91
92#ifdef WORDS_BIGENDIAN
93        " pkhbt r0, r3, r2, LSL #16       \n\t"
94        " pkhbt r1, r5, r4, LSL #16       \n\t"
95#else
96        " pkhbt r0, r2, r3, LSL #16       \n\t"
97        " pkhbt r1, r4, r5, LSL #16       \n\t"
98#endif
99        " strd  r0, [%0], #8              \n\t"
100
101        MOD_INC()
102
103        " subs %3, %3, #4                 \n\t"
104        " cmp %3, #4                      \n\t"
105        " bge 1b                          \n\t"
106
107        "2:                               \n\t"
108        " cmp %3, #2                      \n\t"
109        " blt 3f                          \n\t"
110
111        " ldrd r2, [r6], #8               \n\t" /* 2  samples at a time */
112        " ldr  r0, [%0]                   \n\t"
113
114#ifdef WORDS_BIGENDIAN
115        " smulwt r2, r2, r0               \n\t"
116        " smulwb r3, r3, r0               \n\t"
117#else
118        " smulwb r2, r2, r0               \n\t"
119        " smulwt r3, r3, r0               \n\t"
120#endif
121
122        " ssat r2, #16, r2                \n\t"
123        " ssat r3, #16, r3                \n\t"
124
125#ifdef WORDS_BIGENDIAN
126        " pkhbt r0, r3, r2, LSL #16       \n\t"
127#else
128        " pkhbt r0, r2, r3, LSL #16       \n\t"
129#endif
130        " str  r0, [%0], #4               \n\t"
131
132        MOD_INC()
133
134        " subs %3, %3, #2                 \n\t"
135
136        "3:                               \n\t" /* check for odd # of samples */
137        " cmp %3, #1                      \n\t"
138        " bne 4f                          \n\t"
139
140        " ldr  r0, [r6], #4               \n\t" /* r0 = volume */
141        " ldrh r2, [%0]                   \n\t" /* r2 = sample */
142
143        " smulwb r0, r0, r2               \n\t" /* r0 = (r0 * r2) >> 16 */
144        " ssat r0, #16, r0                \n\t" /* r0 = PA_CLAMP(r0, 0x7FFF) */
145
146        " strh r0, [%0], #2               \n\t" /* sample = r0 */
147
148        "4:                               \n\t"
149
150        : "+r" (samples), "+r" (volumes), "+r" (ve), "+r" (length)
151        : "r" (volumes + ((rem / sizeof(*samples)) % channels))
152        : "r6", "r5", "r4", "r3", "r2", "r1", "r0", "cc"
153    );
154}
155
156#endif /* defined (__arm__) && defined (HAVE_ARMV6) */
157
158void pa_volume_func_init_arm(pa_cpu_arm_flag_t flags) {
159#if defined (__arm__) && defined (HAVE_ARMV6)
160    pa_log_info("Initialising ARM optimized volume functions.");
161
162    if (!_volume_ref)
163        _volume_ref = pa_get_volume_func(PA_SAMPLE_S16NE);
164
165    pa_set_volume_func(PA_SAMPLE_S16NE, (pa_do_volume_func_t) pa_volume_s16ne_arm);
166#endif /* defined (__arm__) && defined (HAVE_ARMV6) */
167}
168