summaryrefslogtreecommitdiffstats
path: root/apps/codecs/libatrac/atrac3_arm.S
blob: 68f8de2c4ec38690ff5f5c15c8c1ab02a852b76e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id: 
 *
 * Copyright (C) 2009 by Andree Buschmann
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/

#include "config.h"

    .section .text, "ax", %progbits

/****************************************************************************
 * void atrac3_iqmf_matrixing(int32_t *dest, 
 *                            int32_t *inlo, 
 *                            int32_t *inhi, 
 *                            unsigned int count);
 * 
 * Matrixing step within iqmf of atrac3 synthesis. Reference implementation:
 *
 * for(i=0; i<counter; i+=2){
 *      dest[2*i+0] = inlo[i  ] + inhi[i  ];
 *      dest[2*i+1] = inlo[i  ] - inhi[i  ];
 *      dest[2*i+2] = inlo[i+1] + inhi[i+1];
 *      dest[2*i+3] = inlo[i+1] - inhi[i+1];
 * }
 * Note: r12 is a scratch register and can be used without restorage.
 ****************************************************************************/
    .align  2
    .global atrac3_iqmf_matrixing
    .type   atrac3_iqmf_matrixing, %function

atrac3_iqmf_matrixing:
    /* r0 = dest */
    /* r1 = inlo */
    /* r2 = inhi */
    /* r3 = counter */
    stmfd   sp!, {r4-r9, lr}       /* save non-scratch registers */
    
.iqmf_matrixing_loop:
    ldmia r1!, { r4, r6, r8, r12}   /* load inlo[0...3] */
    ldmia r2!, { r5, r7, r9, lr }   /* load inhi[0...3] */
    add   r4, r4, r5                /* r4  = inlo[0] + inhi[0] */
    sub   r5, r4, r5, asl #1        /* r5  = inlo[0] - inhi[0] */
    add   r6, r6, r7                /* r6  = inlo[1] + inhi[1] */
    sub   r7, r6, r7, asl #1        /* r7  = inlo[1] - inhi[1] */
    add   r8, r8, r9                /* r8  = inlo[2] + inhi[2] */
    sub   r9, r8, r9, asl #1        /* r9  = inlo[2] - inhi[2] */
    add   r12, r12, lr              /* r12 = inlo[3] + inhi[3] */
    sub   lr , r12, lr, asl #1      /* lr  = inlo[3] - inhi[3] */
    stmia r0!, {r4-r9, r12, lr}     /* store results to dest */
    subs r3, r3, #4                 /* counter -= 4 */
    bgt .iqmf_matrixing_loop
    
    ldmpc   regs=r4-r9              /* restore registers */

.atrac3_iqmf_matrixing_end:
    .size   atrac3_iqmf_matrixing,.atrac3_iqmf_matrixing_end-atrac3_iqmf_matrixing

    
/****************************************************************************
 * atrac3_iqmf_dewindowing(int32_t *out,
 *                         int32_t *in,
 *                         int32_t *win,
 *                         unsigned int nIn);
 * 
 * Dewindowing step within iqmf of atrac3 synthesis. Reference implementation:
 *
 * for (j = nIn; j != 0; j--) {
 *          s1 = fixmul32(in[0], win[0]);
 *          s2 = fixmul32(in[1], win[1]);
 *          for (i = 2; i < 48; i += 2) {
 *              s1 += fixmul32(in[i  ], win[i  ]);
 *              s2 += fixmul32(in[i+1], win[i+1]);
 *          }
 *          out[0] = s2 << 1;
 *          out[1] = s1 << 1;
 *          in += 2;
 *          out += 2;
 *      }
 * Note: r12 is a scratch register and can be used without restorage.
 ****************************************************************************/

/* To be called as first block to call smull for initial filling of the result
 * registers lr/r9 and r12/r8. */
#define DEWIN_8_SAMPLES_MUL_ASM \
    ldmia r2!, {r4, r5};            /* load win[0..1] */ \
    ldmia r1!, {r6, r7};            /* load in [0..1] */ \
    smull lr , r9, r4, r6;          /* s1 = win[0] * in[0] */ \
    smull r12, r8, r5, r7;          /* s2 = win[1] * in[1] */ \
    ldmia r2!, {r4, r5};            /* load win[i..i+1] */ \
    ldmia r1!, {r6, r7};            /* load in [i..i+1] */ \
    smlal lr , r9, r4, r6;          /* s1 = win[i  ] * in[i  ] */ \
    smlal r12, r8, r5, r7;          /* s2 = win[i+1] * in[i+1] */ \
    ldmia r2!, {r4, r5};            /* load win[i..i+1] */ \
    ldmia r1!, {r6, r7};            /* load in [i..i+1] */ \
    smlal lr , r9, r4, r6;          /* s1 = win[i  ] * in[i  ] */ \
    smlal r12, r8, r5, r7;          /* s2 = win[i+1] * in[i+1] */ \
    ldmia r2!, {r4, r5};            /* load win[i..i+1] */ \
    ldmia r1!, {r6, r7};            /* load in [i..i+1] */ \
    smlal lr , r9, r4, r6;          /* s1 = win[i  ] * in[i  ] */ \
    smlal r12, r8, r5, r7;          /* s2 = win[i+1] * in[i+1] */

/* Called after first block. Will always multiply-add to the result registers 
 * lr/r9 and r12/r8. */
#define DEWIN_8_SAMPLES_MLA_ASM \
    ldmia r2!, {r4, r5};            /* load win[i..i+1] */ \
    ldmia r1!, {r6, r7};            /* load in [i..i+1] */ \
    smlal lr , r9, r4, r6;          /* s1 = win[i  ] * in[i  ] */ \
    smlal r12, r8, r5, r7;          /* s2 = win[i+1] * in[i+1] */ \
    ldmia r2!, {r4, r5};            /* load win[i..i+1] */ \
    ldmia r1!, {r6, r7};            /* load in [i..i+1] */ \
    smlal lr , r9, r4, r6;          /* s1 = win[i  ] * in[i  ] */ \
    smlal r12, r8, r5, r7;          /* s2 = win[i+1] * in[i+1] */ \
    ldmia r2!, {r4, r5};            /* load win[i..i+1] */ \
    ldmia r1!, {r6, r7};            /* load in [i..i+1] */ \
    smlal lr , r9, r4, r6;          /* s1 = win[i  ] * in[i  ] */ \
    smlal r12, r8, r5, r7;          /* s2 = win[i+1] * in[i+1] */ \
    ldmia r2!, {r4, r5};            /* load win[i..i+1] */ \
    ldmia r1!, {r6, r7};            /* load in [i..i+1] */ \
    smlal lr , r9, r4, r6;          /* s1 = win[i  ] * in[i  ] */ \
    smlal r12, r8, r5, r7;          /* s2 = win[i+1] * in[i+1] */

    .align  2
    .global atrac3_iqmf_dewindowing
    .type   atrac3_iqmf_dewindowing, %function
    
atrac3_iqmf_dewindowing:
    /* r0 = dest */
    /* r1 = input samples */
    /* r2 = window coefficients */
    /* r3 = counter */
    stmfd   sp!, {r4-r9, lr}        /* save non-scratch registers */
    
.iqmf_dewindow_outer_loop:          /* outer loop 0...counter-1 */
    
    DEWIN_8_SAMPLES_MUL_ASM         /*  0.. 7, use "MUL" macro here! */
    DEWIN_8_SAMPLES_MLA_ASM         /*  8..15 */
    DEWIN_8_SAMPLES_MLA_ASM         /* 16..23 */
    DEWIN_8_SAMPLES_MLA_ASM         /* 24..31 */
    DEWIN_8_SAMPLES_MLA_ASM         /* 32..39 */
    DEWIN_8_SAMPLES_MLA_ASM         /* 40..47 */

    mov   lr , lr , lsr #31
    orr   r9, lr , r9, lsl #1       /* s1 = low>>31 || hi<<1 */
    mov   r12, r12, lsr #31
    orr   r8, r12, r8, lsl #1       /* s2 = low>>31 || hi<<1 */

    stmia r0!, {r8, r9}             /* store result out[0]=s2, out[1]=s1 */
    sub   r1, r1, #184              /* roll back 64 entries = 184 bytes */
    sub   r2, r2, #192              /* roll back 48 entries = 192 bytes = win[0] */

    subs r3, r3, #1                 /* outer loop -= 1 */
    bgt .iqmf_dewindow_outer_loop
    
    ldmpc   regs=r4-r9              /* restore registers */
    
.atrac3_iqmf_dewindowing_end:
    .size   atrac3_iqmf_dewindowing,.atrac3_iqmf_dewindowing_end-atrac3_iqmf_dewindowing