1/*
2 * Copyright (C) 2010 Mans Rullgard <mans@mansr.com>
3 *
4 * This file is part of Libav.
5 *
6 * Libav is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * Libav is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with Libav; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#ifndef AVCODEC_ARM_VP56_ARITH_H
22#define AVCODEC_ARM_VP56_ARITH_H
23
24#if CONFIG_THUMB
25#   define A(x)
26#   define T(x) x
27#else
28#   define A(x) x
29#   define T(x)
30#endif
31
32#if HAVE_ARMV6 && HAVE_INLINE_ASM
33
34#define vp56_rac_get_prob vp56_rac_get_prob_armv6
35static inline int vp56_rac_get_prob_armv6(VP56RangeCoder *c, int pr)
36{
37    unsigned shift     = ff_vp56_norm_shift[c->high];
38    unsigned code_word = c->code_word << shift;
39    unsigned high      = c->high << shift;
40    unsigned bit;
41
42    __asm__ ("adds    %3,  %3,  %0           \n"
43             "itt     cs                     \n"
44             "cmpcs   %7,  %4                \n"
45           A("ldrcsh  %2,  [%4], #2          \n")
46           T("ldrhcs  %2,  [%4], #2          \n")
47             "rsb     %0,  %6,  #256         \n"
48             "smlabb  %0,  %5,  %6,  %0      \n"
49           T("itttt   cs                     \n")
50             "rev16cs %2,  %2                \n"
51           T("lslcs   %2,  %2,  %3           \n")
52           T("orrcs   %1,  %1,  %2           \n")
53           A("orrcs   %1,  %1,  %2,  lsl %3  \n")
54             "subcs   %3,  %3,  #16          \n"
55             "lsr     %0,  %0,  #8           \n"
56             "cmp     %1,  %0,  lsl #16      \n"
57             "ittte   ge                     \n"
58             "subge   %1,  %1,  %0,  lsl #16 \n"
59             "subge   %0,  %5,  %0           \n"
60             "movge   %2,  #1                \n"
61             "movlt   %2,  #0                \n"
62             : "=&r"(c->high), "=&r"(c->code_word), "=&r"(bit),
63               "+&r"(c->bits), "+&r"(c->buffer)
64             : "r"(high), "r"(pr), "r"(c->end - 1),
65               "0"(shift), "1"(code_word)
66             : "cc");
67
68    return bit;
69}
70
71#define vp56_rac_get_prob_branchy vp56_rac_get_prob_branchy_armv6
72static inline int vp56_rac_get_prob_branchy_armv6(VP56RangeCoder *c, int pr)
73{
74    unsigned shift     = ff_vp56_norm_shift[c->high];
75    unsigned code_word = c->code_word << shift;
76    unsigned high      = c->high << shift;
77    unsigned low;
78    unsigned tmp;
79
80    __asm__ ("adds    %3,  %3,  %0           \n"
81             "itt     cs                     \n"
82             "cmpcs   %7,  %4                \n"
83           A("ldrcsh  %2,  [%4], #2          \n")
84           T("ldrhcs  %2,  [%4], #2          \n")
85             "rsb     %0,  %6,  #256         \n"
86             "smlabb  %0,  %5,  %6,  %0      \n"
87           T("itttt   cs                     \n")
88             "rev16cs %2,  %2                \n"
89           T("lslcs   %2,  %2,  %3           \n")
90           T("orrcs   %1,  %1,  %2           \n")
91           A("orrcs   %1,  %1,  %2,  lsl %3  \n")
92             "subcs   %3,  %3,  #16          \n"
93             "lsr     %0,  %0,  #8           \n"
94             "lsl     %2,  %0,  #16          \n"
95             : "=&r"(low), "+&r"(code_word), "=&r"(tmp),
96               "+&r"(c->bits), "+&r"(c->buffer)
97             : "r"(high), "r"(pr), "r"(c->end - 1), "0"(shift)
98             : "cc");
99
100    if (code_word >= tmp) {
101        c->high      = high - low;
102        c->code_word = code_word - tmp;
103        return 1;
104    }
105
106    c->high      = low;
107    c->code_word = code_word;
108    return 0;
109}
110
111#endif
112
113#endif /* AVCODEC_ARM_VP56_ARITH_H */
114