| 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 |
| 30 | static 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 */ |