1/* 2 * This file is part of FFmpeg. 3 * 4 * FFmpeg is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU Lesser General Public 6 * License as published by the Free Software Foundation; either 7 * version 2.1 of the License, or (at your option) any later version. 8 * 9 * FFmpeg is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * Lesser General Public License for more details. 13 * 14 * You should have received a copy of the GNU Lesser General Public 15 * License along with FFmpeg; if not, write to the Free Software 16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 17 */ 18 19#ifndef AVCODEC_ARM_CABAC_H 20#define AVCODEC_ARM_CABAC_H 21 22#include "config.h" 23#if HAVE_ARMV6T2_INLINE 24 25#include "libavutil/attributes.h" 26#include "libavutil/internal.h" 27#include "libavcodec/cabac.h" 28 29#define get_cabac_inline get_cabac_inline_arm 30static av_always_inline int get_cabac_inline_arm(CABACContext *c, 31 uint8_t *const state) 32{ 33 int bit; 34 void *reg_b, *reg_c, *tmp; 35 36 __asm__ volatile( 37 "ldrb %[bit] , [%[state]] \n\t" 38 "add %[r_b] , %[tables] , %[lps_off] \n\t" 39 "mov %[tmp] , %[range] \n\t" 40 "and %[range] , %[range] , #0xC0 \n\t" 41 "add %[r_b] , %[r_b] , %[bit] \n\t" 42 "ldrb %[range] , [%[r_b], %[range], lsl #1] \n\t" 43 "add %[r_b] , %[tables] , %[norm_off] \n\t" 44 "sub %[r_c] , %[tmp] , %[range] \n\t" 45 "lsl %[tmp] , %[r_c] , #17 \n\t" 46 "cmp %[tmp] , %[low] \n\t" 47 "it gt \n\t" 48 "movgt %[range] , %[r_c] \n\t" 49 "itt cc \n\t" 50 "mvncc %[bit] , %[bit] \n\t" 51 "subcc %[low] , %[low] , %[tmp] \n\t" 52 "add %[r_c] , %[tables] , %[mlps_off] \n\t" 53 "ldrb %[tmp] , [%[r_b], %[range]] \n\t" 54 "ldrb %[r_b] , [%[r_c], %[bit]] \n\t" 55 "lsl %[low] , %[low] , %[tmp] \n\t" 56 "lsl %[range] , %[range] , %[tmp] \n\t" 57 "uxth %[r_c] , %[low] \n\t" 58 "strb %[r_b] , [%[state]] \n\t" 59 "tst %[r_c] , %[r_c] \n\t" 60 "bne 2f \n\t" 61 "ldr %[r_c] , [%[c], %[byte]] \n\t" 62#if UNCHECKED_BITSTREAM_READER 63 "ldrh %[tmp] , [%[r_c]] \n\t" 64 "add %[r_c] , %[r_c] , #2 \n\t" 65 "str %[r_c] , [%[c], %[byte]] \n\t" 66#else 67 "ldr %[r_b] , [%[c], %[end]] \n\t" 68 "ldrh %[tmp] , [%[r_c]] \n\t" 69 "cmp %[r_c] , %[r_b] \n\t" 70 "itt lt \n\t" 71 "addlt %[r_c] , %[r_c] , #2 \n\t" 72 "strlt %[r_c] , [%[c], %[byte]] \n\t" 73#endif 74 "sub %[r_c] , %[low] , #1 \n\t" 75 "add %[r_b] , %[tables] , %[norm_off] \n\t" 76 "eor %[r_c] , %[low] , %[r_c] \n\t" 77 "rev %[tmp] , %[tmp] \n\t" 78 "lsr %[r_c] , %[r_c] , #15 \n\t" 79 "lsr %[tmp] , %[tmp] , #15 \n\t" 80 "ldrb %[r_c] , [%[r_b], %[r_c]] \n\t" 81 "movw %[r_b] , #0xFFFF \n\t" 82 "sub %[tmp] , %[tmp] , %[r_b] \n\t" 83 "rsb %[r_c] , %[r_c] , #7 \n\t" 84 "lsl %[tmp] , %[tmp] , %[r_c] \n\t" 85 "add %[low] , %[low] , %[tmp] \n\t" 86 "2: \n\t" 87 : [bit]"=&r"(bit), 88 [low]"+&r"(c->low), 89 [range]"+&r"(c->range), 90 [r_b]"=&r"(reg_b), 91 [r_c]"=&r"(reg_c), 92 [tmp]"=&r"(tmp) 93 : [c]"r"(c), 94 [state]"r"(state), 95 [tables]"r"(ff_h264_cabac_tables), 96 [byte]"M"(offsetof(CABACContext, bytestream)), 97 [end]"M"(offsetof(CABACContext, bytestream_end)), 98 [norm_off]"I"(H264_NORM_SHIFT_OFFSET), 99 [lps_off]"I"(H264_LPS_RANGE_OFFSET), 100 [mlps_off]"I"(H264_MLPS_STATE_OFFSET + 128) 101 : "memory", "cc" 102 ); 103 104 return bit & 1; 105} 106#endif /* HAVE_ARMV6T2_INLINE */ 107 108#endif /* AVCODEC_ARM_CABAC_H */ 109