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 Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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 */
38
39.macro  dequant_t       dst, src, mul, add, tmp
40        rsbs            \tmp, ip, \src, asr #16
41        it              gt
42        addgt           \tmp, \add, #0
43        it              lt
44        rsblt           \tmp, \add, #0
45        it              ne
46        smlatbne        \dst, \src, \mul, \tmp
47.endm
48
49.macro  dequant_b       dst, src, mul, add, tmp
50        rsbs            \tmp, ip, \src, lsl #16
51        it              gt
52        addgt           \tmp, \add, #0
53        it              lt
54        rsblt           \tmp, \add, #0
55        it              ne
56        smlabbne        \dst, \src, \mul, \tmp
57.endm
58
59function ff_dct_unquantize_h263_armv5te, export=1
60        push            {r4-r9,lr}
61        mov             ip, #0
62        subs            r3, r3, #2
63        ble             2f
64        ldrd            r4, [r0, #0]
651:
66        ldrd            r6, [r0, #8]
67
68        dequant_t       r9, r4, r1, r2, r9
69        dequant_t       lr, r5, r1, r2, lr
70        dequant_b       r4, r4, r1, r2, r8
71        dequant_b       r5, r5, r1, r2, r8
72
73        strh            r4, [r0], #2
74        strh            r9, [r0], #2
75        strh            r5, [r0], #2
76        strh            lr, [r0], #2
77
78        dequant_t       r9, r6, r1, r2, r9
79        dequant_t       lr, r7, r1, r2, lr
80        dequant_b       r6, r6, r1, r2, r8
81        dequant_b       r7, r7, r1, r2, r8
82
83        strh            r6, [r0], #2
84        strh            r9, [r0], #2
85        strh            r7, [r0], #2
86        strh            lr, [r0], #2
87
88        subs            r3, r3, #8
89        it              gt
90        ldrdgt          r4, [r0, #0] /* load data early to avoid load/use pipeline stall */
91        bgt             1b
92
93        adds            r3, r3, #2
94        it              le
95        pople           {r4-r9,pc}
962:
97        ldrsh           r9, [r0, #0]
98        ldrsh           lr, [r0, #2]
99        mov             r8, r2
100        cmp             r9, #0
101        it              lt
102        rsblt           r8, r2, #0
103        it              ne
104        smlabbne        r9, r9, r1, r8
105        mov             r8, r2
106        cmp             lr, #0
107        it              lt
108        rsblt           r8, r2, #0
109        it              ne
110        smlabbne        lr, lr, r1, r8
111        strh            r9, [r0], #2
112        strh            lr, [r0], #2
113        pop             {r4-r9,pc}
114endfunc
115