1/*
2 * Optimization of some functions from mpegvideo.c for armv5te
3 * Copyright (c) 2007 Siarhei Siamashka <ssvb@users.sourceforge.net>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22#include "config.h"
23#include "asm.S"
24
25/*
26 * Special optimized version of dct_unquantize_h263_helper_c, it
27 * requires the block to be at least 8 bytes aligned, and may process
28 * more elements than requested.  But it is guaranteed to never
29 * process more than 64 elements provided that count argument is <= 64,
30 * so it is safe. This function is optimized for a common distribution
31 * of values for nCoeffs (they are mostly multiple of 8 plus one or
32 * two extra elements). So this function processes data as 8 elements
33 * per loop iteration and contains optional 2 elements processing in
34 * the end.
35 *
36 * Inner loop should take 6 cycles per element on arm926ej-s (Nokia 770)
37 */
38function ff_dct_unquantize_h263_armv5te, export=1
39        push            {r4-r9,lr}
40        mov             ip, #0
41        subs            r3, r3, #2
42        ble             2f
43        ldrd            r4, [r0, #0]
441:
45        ldrd            r6, [r0, #8]
46
47        rsbs            r9, ip, r4, asr #16
48        addgt           r9, r2, #0
49        rsblt           r9, r2, #0
50        smlatbne        r9, r4, r1, r9
51
52        rsbs            lr, ip, r5, asr #16
53        addgt           lr, r2, #0
54        rsblt           lr, r2, #0
55        smlatbne        lr, r5, r1, lr
56
57        rsbs            r8, ip, r4, asl #16
58        addgt           r8, r2, #0
59        rsblt           r8, r2, #0
60        smlabbne        r4, r4, r1, r8
61
62        rsbs            r8, ip, r5, asl #16
63        addgt           r8, r2, #0
64        rsblt           r8, r2, #0
65        smlabbne        r5, r5, r1, r8
66
67        strh            r4, [r0], #2
68        strh            r9, [r0], #2
69        strh            r5, [r0], #2
70        strh            lr, [r0], #2
71
72        rsbs            r9, ip, r6, asr #16
73        addgt           r9, r2, #0
74        rsblt           r9, r2, #0
75        smlatbne        r9, r6, r1, r9
76
77        rsbs            lr, ip, r7, asr #16
78        addgt           lr, r2, #0
79        rsblt           lr, r2, #0
80        smlatbne        lr, r7, r1, lr
81
82        rsbs            r8, ip, r6, asl #16
83        addgt           r8, r2, #0
84        rsblt           r8, r2, #0
85        smlabbne        r6, r6, r1, r8
86
87        rsbs            r8, ip, r7, asl #16
88        addgt           r8, r2, #0
89        rsblt           r8, r2, #0
90        smlabbne        r7, r7, r1, r8
91
92        strh            r6, [r0], #2
93        strh            r9, [r0], #2
94        strh            r7, [r0], #2
95        strh            lr, [r0], #2
96
97        subs            r3, r3, #8
98        ldrgtd          r4, [r0, #0] /* load data early to avoid load/use pipeline stall */
99        bgt             1b
100
101        adds            r3, r3, #2
102        pople           {r4-r9,pc}
1032:
104        ldrsh           r9, [r0, #0]
105        ldrsh           lr, [r0, #2]
106        mov             r8, r2
107        cmp             r9, #0
108        rsblt           r8, r2, #0
109        smlabbne        r9, r9, r1, r8
110        mov             r8, r2
111        cmp             lr, #0
112        rsblt           r8, r2, #0
113        smlabbne        lr, lr, r1, r8
114        strh            r9, [r0], #2
115        strh            lr, [r0], #2
116        pop             {r4-r9,pc}
117        .endfunc
118