| /* |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #ifndef AVCODEC_ARM_CABAC_H |
| #define AVCODEC_ARM_CABAC_H |
| |
| #include "config.h" |
| #if HAVE_ARMV6T2_INLINE |
| |
| #include "libavutil/attributes.h" |
| #include "libavutil/internal.h" |
| #include "libavcodec/cabac.h" |
| |
| #define get_cabac_inline get_cabac_inline_arm |
| static av_always_inline int get_cabac_inline_arm(CABACContext *c, |
| uint8_t *const state) |
| { |
| int bit; |
| void *reg_b, *reg_c, *tmp; |
| |
| __asm__ volatile( |
| "ldrb %[bit] , [%[state]] \n\t" |
| "add %[r_b] , %[tables] , %[lps_off] \n\t" |
| "mov %[tmp] , %[range] \n\t" |
| "and %[range] , %[range] , #0xC0 \n\t" |
| "add %[r_b] , %[r_b] , %[bit] \n\t" |
| "ldrb %[range] , [%[r_b], %[range], lsl #1] \n\t" |
| "add %[r_b] , %[tables] , %[norm_off] \n\t" |
| "sub %[r_c] , %[tmp] , %[range] \n\t" |
| "lsl %[tmp] , %[r_c] , #17 \n\t" |
| "cmp %[tmp] , %[low] \n\t" |
| "it gt \n\t" |
| "movgt %[range] , %[r_c] \n\t" |
| "itt cc \n\t" |
| "mvncc %[bit] , %[bit] \n\t" |
| "subcc %[low] , %[low] , %[tmp] \n\t" |
| "add %[r_c] , %[tables] , %[mlps_off] \n\t" |
| "ldrb %[tmp] , [%[r_b], %[range]] \n\t" |
| "ldrb %[r_b] , [%[r_c], %[bit]] \n\t" |
| "lsl %[low] , %[low] , %[tmp] \n\t" |
| "lsl %[range] , %[range] , %[tmp] \n\t" |
| "uxth %[r_c] , %[low] \n\t" |
| "strb %[r_b] , [%[state]] \n\t" |
| "tst %[r_c] , %[r_c] \n\t" |
| "bne 2f \n\t" |
| "ldr %[r_c] , [%[c], %[byte]] \n\t" |
| #if UNCHECKED_BITSTREAM_READER |
| "ldrh %[tmp] , [%[r_c]] \n\t" |
| "add %[r_c] , %[r_c] , #2 \n\t" |
| "str %[r_c] , [%[c], %[byte]] \n\t" |
| #else |
| "ldr %[r_b] , [%[c], %[end]] \n\t" |
| "ldrh %[tmp] , [%[r_c]] \n\t" |
| "cmp %[r_c] , %[r_b] \n\t" |
| "itt lt \n\t" |
| "addlt %[r_c] , %[r_c] , #2 \n\t" |
| "strlt %[r_c] , [%[c], %[byte]] \n\t" |
| #endif |
| "sub %[r_c] , %[low] , #1 \n\t" |
| "add %[r_b] , %[tables] , %[norm_off] \n\t" |
| "eor %[r_c] , %[low] , %[r_c] \n\t" |
| "rev %[tmp] , %[tmp] \n\t" |
| "lsr %[r_c] , %[r_c] , #15 \n\t" |
| "lsr %[tmp] , %[tmp] , #15 \n\t" |
| "ldrb %[r_c] , [%[r_b], %[r_c]] \n\t" |
| "movw %[r_b] , #0xFFFF \n\t" |
| "sub %[tmp] , %[tmp] , %[r_b] \n\t" |
| "rsb %[r_c] , %[r_c] , #7 \n\t" |
| "lsl %[tmp] , %[tmp] , %[r_c] \n\t" |
| "add %[low] , %[low] , %[tmp] \n\t" |
| "2: \n\t" |
| : [bit]"=&r"(bit), |
| [low]"+&r"(c->low), |
| [range]"+&r"(c->range), |
| [r_b]"=&r"(reg_b), |
| [r_c]"=&r"(reg_c), |
| [tmp]"=&r"(tmp) |
| : [c]"r"(c), |
| [state]"r"(state), |
| [tables]"r"(ff_h264_cabac_tables), |
| [byte]"M"(offsetof(CABACContext, bytestream)), |
| [end]"M"(offsetof(CABACContext, bytestream_end)), |
| [norm_off]"I"(H264_NORM_SHIFT_OFFSET), |
| [lps_off]"I"(H264_LPS_RANGE_OFFSET), |
| [mlps_off]"I"(H264_MLPS_STATE_OFFSET + 128) |
| : "memory", "cc" |
| ); |
| |
| return bit & 1; |
| } |
| #endif /* HAVE_ARMV6T2_INLINE */ |
| |
| #endif /* AVCODEC_ARM_CABAC_H */ |
