mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-11-26 19:01:44 +02:00
e1a5ee25e0
* qatar/master: arm: Add assembly version of h264_find_start_code_candidate Merged-by: Michael Niedermayer <michaelni@gmx.at>
254 lines
7.4 KiB
ArmAsm
254 lines
7.4 KiB
ArmAsm
/*
|
|
* Copyright (c) 2013 RISC OS Open Ltd
|
|
* Author: Ben Avison <bavison@riscosopen.org>
|
|
*
|
|
* 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
|
|
*/
|
|
|
|
#include "libavutil/arm/asm.S"
|
|
|
|
RESULT .req a1
|
|
BUF .req a1
|
|
SIZE .req a2
|
|
PATTERN .req a3
|
|
PTR .req a4
|
|
DAT0 .req v1
|
|
DAT1 .req v2
|
|
DAT2 .req v3
|
|
DAT3 .req v4
|
|
TMP0 .req v5
|
|
TMP1 .req v6
|
|
TMP2 .req ip
|
|
TMP3 .req lr
|
|
|
|
#define PRELOAD_DISTANCE 4
|
|
|
|
.macro innerloop4
|
|
ldr DAT0, [PTR], #4
|
|
subs SIZE, SIZE, #4 @ C flag survives rest of macro
|
|
sub TMP0, DAT0, PATTERN, lsr #14
|
|
bic TMP0, TMP0, DAT0
|
|
ands TMP0, TMP0, PATTERN
|
|
.endm
|
|
|
|
.macro innerloop16 decrement, do_preload
|
|
ldmia PTR!, {DAT0,DAT1,DAT2,DAT3}
|
|
.ifnc "\do_preload",""
|
|
pld [PTR, #PRELOAD_DISTANCE*32]
|
|
.endif
|
|
.ifnc "\decrement",""
|
|
subs SIZE, SIZE, #\decrement @ C flag survives rest of macro
|
|
.endif
|
|
sub TMP0, DAT0, PATTERN, lsr #14
|
|
sub TMP1, DAT1, PATTERN, lsr #14
|
|
bic TMP0, TMP0, DAT0
|
|
bic TMP1, TMP1, DAT1
|
|
sub TMP2, DAT2, PATTERN, lsr #14
|
|
sub TMP3, DAT3, PATTERN, lsr #14
|
|
ands TMP0, TMP0, PATTERN
|
|
bic TMP2, TMP2, DAT2
|
|
it eq
|
|
andseq TMP1, TMP1, PATTERN
|
|
bic TMP3, TMP3, DAT3
|
|
itt eq
|
|
andseq TMP2, TMP2, PATTERN
|
|
andseq TMP3, TMP3, PATTERN
|
|
.endm
|
|
|
|
/* int ff_h264_find_start_code_candidate_armv6(const uint8_t *buf, int size) */
|
|
function ff_h264_find_start_code_candidate_armv6, export=1
|
|
push {v1-v6,lr}
|
|
mov PTR, BUF
|
|
@ Ensure there are at least (PRELOAD_DISTANCE+2) complete cachelines to go
|
|
@ before using code that does preloads
|
|
cmp SIZE, #(PRELOAD_DISTANCE+3)*32 - 1
|
|
blo 60f
|
|
|
|
@ Get to word-alignment, 1 byte at a time
|
|
tst PTR, #3
|
|
beq 2f
|
|
1: ldrb DAT0, [PTR], #1
|
|
sub SIZE, SIZE, #1
|
|
teq DAT0, #0
|
|
beq 90f
|
|
tst PTR, #3
|
|
bne 1b
|
|
2: @ Get to 4-word alignment, 1 word at a time
|
|
ldr PATTERN, =0x80008000
|
|
setend be
|
|
tst PTR, #12
|
|
beq 4f
|
|
3: innerloop4
|
|
bne 91f
|
|
tst PTR, #12
|
|
bne 3b
|
|
4: @ Get to cacheline (8-word) alignment
|
|
tst PTR, #16
|
|
beq 5f
|
|
innerloop16 16
|
|
bne 93f
|
|
5: @ Check complete cachelines, with preloading
|
|
@ We need to stop when there are still (PRELOAD_DISTANCE+1)
|
|
@ complete cachelines to go
|
|
sub SIZE, SIZE, #(PRELOAD_DISTANCE+2)*32
|
|
6: innerloop16 , do_preload
|
|
bne 93f
|
|
innerloop16 32
|
|
bne 93f
|
|
bcs 6b
|
|
@ Preload trailing part-cacheline, if any
|
|
tst SIZE, #31
|
|
beq 7f
|
|
pld [PTR, #(PRELOAD_DISTANCE+1)*32]
|
|
@ Check remaining data without doing any more preloads. First
|
|
@ do in chunks of 4 words:
|
|
7: adds SIZE, SIZE, #(PRELOAD_DISTANCE+2)*32 - 16
|
|
bmi 9f
|
|
8: innerloop16 16
|
|
bne 93f
|
|
bcs 8b
|
|
@ Then in words:
|
|
9: adds SIZE, SIZE, #16 - 4
|
|
bmi 11f
|
|
10: innerloop4
|
|
bne 91f
|
|
bcs 10b
|
|
11: setend le
|
|
@ Check second byte of final halfword
|
|
ldrb DAT0, [PTR, #-1]
|
|
teq DAT0, #0
|
|
beq 90f
|
|
@ Check any remaining bytes
|
|
tst SIZE, #3
|
|
beq 13f
|
|
12: ldrb DAT0, [PTR], #1
|
|
sub SIZE, SIZE, #1
|
|
teq DAT0, #0
|
|
beq 90f
|
|
tst SIZE, #3
|
|
bne 12b
|
|
@ No candidate found
|
|
13: sub RESULT, PTR, BUF
|
|
b 99f
|
|
|
|
60: @ Small buffer - simply check by looping over bytes
|
|
subs SIZE, SIZE, #1
|
|
bcc 99f
|
|
61: ldrb DAT0, [PTR], #1
|
|
subs SIZE, SIZE, #1
|
|
teq DAT0, #0
|
|
beq 90f
|
|
bcs 61b
|
|
@ No candidate found
|
|
sub RESULT, PTR, BUF
|
|
b 99f
|
|
|
|
90: @ Found a candidate at the preceding byte
|
|
sub RESULT, PTR, BUF
|
|
sub RESULT, RESULT, #1
|
|
b 99f
|
|
|
|
91: @ Found a candidate somewhere in the preceding 4 bytes
|
|
sub RESULT, PTR, BUF
|
|
sub RESULT, RESULT, #4
|
|
sub TMP0, DAT0, #0x20000
|
|
bics TMP0, TMP0, DAT0
|
|
itt pl
|
|
ldrbpl DAT0, [PTR, #-3]
|
|
addpl RESULT, RESULT, #2
|
|
bpl 92f
|
|
teq RESULT, #0
|
|
beq 98f @ don't look back a byte if found at first byte in buffer
|
|
ldrb DAT0, [PTR, #-5]
|
|
92: teq DAT0, #0
|
|
it eq
|
|
subeq RESULT, RESULT, #1
|
|
b 98f
|
|
|
|
93: @ Found a candidate somewhere in the preceding 16 bytes
|
|
sub RESULT, PTR, BUF
|
|
sub RESULT, RESULT, #16
|
|
teq TMP0, #0
|
|
beq 95f @ not in first 4 bytes
|
|
sub TMP0, DAT0, #0x20000
|
|
bics TMP0, TMP0, DAT0
|
|
itt pl
|
|
ldrbpl DAT0, [PTR, #-15]
|
|
addpl RESULT, RESULT, #2
|
|
bpl 94f
|
|
teq RESULT, #0
|
|
beq 98f @ don't look back a byte if found at first byte in buffer
|
|
ldrb DAT0, [PTR, #-17]
|
|
94: teq DAT0, #0
|
|
it eq
|
|
subeq RESULT, RESULT, #1
|
|
b 98f
|
|
95: add RESULT, RESULT, #4
|
|
teq TMP1, #0
|
|
beq 96f @ not in next 4 bytes
|
|
sub TMP1, DAT1, #0x20000
|
|
bics TMP1, TMP1, DAT1
|
|
itee mi
|
|
ldrbmi DAT0, [PTR, #-13]
|
|
ldrbpl DAT0, [PTR, #-11]
|
|
addpl RESULT, RESULT, #2
|
|
teq DAT0, #0
|
|
it eq
|
|
subeq RESULT, RESULT, #1
|
|
b 98f
|
|
96: add RESULT, RESULT, #4
|
|
teq TMP2, #0
|
|
beq 97f @ not in next 4 bytes
|
|
sub TMP2, DAT2, #0x20000
|
|
bics TMP2, TMP2, DAT2
|
|
itee mi
|
|
ldrbmi DAT0, [PTR, #-9]
|
|
ldrbpl DAT0, [PTR, #-7]
|
|
addpl RESULT, RESULT, #2
|
|
teq DAT0, #0
|
|
it eq
|
|
subeq RESULT, RESULT, #1
|
|
b 98f
|
|
97: add RESULT, RESULT, #4
|
|
sub TMP3, DAT3, #0x20000
|
|
bics TMP3, TMP3, DAT3
|
|
itee mi
|
|
ldrbmi DAT0, [PTR, #-5]
|
|
ldrbpl DAT0, [PTR, #-3]
|
|
addpl RESULT, RESULT, #2
|
|
teq DAT0, #0
|
|
it eq
|
|
subeq RESULT, RESULT, #1
|
|
@ drop through to 98f
|
|
98: setend le
|
|
99: pop {v1-v6,pc}
|
|
.endfunc
|
|
|
|
.unreq RESULT
|
|
.unreq BUF
|
|
.unreq SIZE
|
|
.unreq PATTERN
|
|
.unreq PTR
|
|
.unreq DAT0
|
|
.unreq DAT1
|
|
.unreq DAT2
|
|
.unreq DAT3
|
|
.unreq TMP0
|
|
.unreq TMP1
|
|
.unreq TMP2
|
|
.unreq TMP3
|