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FFmpeg/libavcodec/arm/ac3dsp_armv6.S
Mans Rullgard 62634158b7 ARM: generate position independent code to access data symbols
This creates proper position independent code when accessing
data symbols if CONFIG_PIC is set.

References to external symbols should now use the movrelx macro.
Some additional code changes are required since this macro may
need a register to hold the GOT pointer.

Signed-off-by: Mans Rullgard <mans@mansr.com>
2012-07-01 11:25:06 +01:00

85 lines
3.4 KiB
ArmAsm

/*
* Copyright (c) 2011 Mans Rullgard <mans@mansr.com>
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/arm/asm.S"
function ff_ac3_bit_alloc_calc_bap_armv6, export=1
ldr r12, [sp]
cmp r12, #-960
beq 4f
push {r4-r11,lr}
add r5, sp, #40
movrelx r4, X(ff_ac3_bin_to_band_tab), r11
movrelx lr, X(ff_ac3_band_start_tab)
ldm r5, {r5-r7}
ldrb r4, [r4, r2]
add r1, r1, r2, lsl #1 @ psd + start
add r0, r0, r4, lsl #1 @ mask + band
add r4, lr, r4
add r7, r7, r2 @ bap + start
1:
ldrsh r9, [r0], #2 @ mask[band]
mov r8, #0xff0
sub r9, r9, r12 @ - snr_offset
ldrb r10, [r4, #1]! @ band_start_tab[++band]
subs r9, r9, r5 @ - floor
it lt
movlt r9, #0
cmp r10, r3 @ - end
and r9, r9, r8, lsl #1 @ & 0x1fe0
ite gt
subgt r8, r3, r2
suble r8, r10, r2
mov r2, r10
add r9, r9, r5 @ + floor => m
tst r8, #1
add r11, r7, r8
bne 3f
b 5f
2:
ldrsh r8, [r1], #2
ldrsh lr, [r1], #2
sub r8, r8, r9
sub lr, lr, r9
usat r8, #6, r8, asr #5 @ address
usat lr, #6, lr, asr #5
ldrb r8, [r6, r8] @ bap_tab[address]
ldrb lr, [r6, lr]
strb r8, [r7], #1 @ bap[bin]
strb lr, [r7], #1
5: cmp r7, r11
blo 2b
cmp r3, r10
bgt 1b
pop {r4-r11,pc}
3:
ldrsh r8, [r1], #2 @ psd[bin]
sub r8, r8, r9 @ - m
usat r8, #6, r8, asr #5 @ address
ldrb r8, [r6, r8] @ bap_tab[address]
strb r8, [r7], #1 @ bap[bin]
b 5b
4:
ldr r0, [sp, #12]
mov r1, #0
mov r2, #256
b X(memset)
endfunc