rockbox/lib/rbcodec/dsp/dsp_arm_v6.S
Sean Bartell b5716df4cb Build librbcodec with DSP and metadata.
All associated files are moved to /lib/rbcodec.

Change-Id: I572ddd2b8a996aae1e98c081d06b1ed356dce222
2012-03-18 12:00:39 +01:00

127 lines
5.8 KiB
ArmAsm

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2010 Michael Sevakis
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
/****************************************************************************
* void sample_output_mono(int count, struct dsp_data *data,
* const int32_t *src[], int16_t *dst)
*/
.section .text, "ax", %progbits
.align 2
.global sample_output_mono
.type sample_output_mono, %function
sample_output_mono:
@ input: r0 = count, r1 = data, r2 = src, r3 = dst
stmfd sp!, { r4, lr } @
@
ldr r1, [r1] @ r1 = data->output_scale
ldr r2, [r2] @ r2 = src[0]
@
mov r4, #1 @ r4 = 1 << (scale - 1)
mov r4, r4, lsl r1 @
subs r0, r0, #1 @ odd: end at 0; even: end at -1
mov r4, r4, lsr #1 @
beq 2f @ Zero? Only one sample!
@
1: @
ldmia r2!, { r12, r14 } @ load Mi0, Mi1
qadd r12, r12, r4 @ round, scale, saturate and
qadd r14, r14, r4 @ pack Mi0 to So0, Mi1 to So1
mov r12, r12, asr r1 @
mov r14, r14, asr r1 @
ssat r12, #16, r12 @
ssat r14, #16, r14 @
pkhbt r12, r12, r12, asl #16 @
pkhbt r14, r14, r14, asl #16 @
subs r0, r0, #2 @
stmia r3!, { r12, r14 } @ store So0, So1
bgt 1b @
@
ldmltfd sp!, { r4, pc } @ if count was even, we're done
@
2: @
ldr r12, [r2] @ round, scale, saturate
qadd r12, r12, r4 @ and pack Mi to So
mov r12, r12, asr r1 @
ssat r12, #16, r12 @
pkhbt r12, r12, r12, asl #16 @
str r12, [r3] @ store So
@
ldmfd sp!, { r4, pc } @
.size sample_output_mono, .-sample_output_mono
/****************************************************************************
* void sample_output_stereo(int count, struct dsp_data *data,
* const int32_t *src[], int16_t *dst)
*/
.section .text, "ax", %progbits
.align 2
.global sample_output_stereo
.type sample_output_stereo, %function
sample_output_stereo:
@ input: r0 = count, r1 = data, r2 = src, r3 = dst
stmfd sp!, { r4-r7, lr } @
@
ldr r1, [r1] @ r1 = data->output_scale
ldmia r2, { r2, r4 } @ r2 = src[0], r4 = src[1]
@
mov r5, #1 @ r5 = 1 << (scale - 1)
mov r5, r5, lsl r1 @
subs r0, r0, #1 @ odd: end at 0; even: end at -1
mov r5, r5, lsr #1 @
beq 2f @ Zero? Only one sample!
@
1: @
ldmia r2!, { r6, r7 } @ r6, r7 = Li0, Li1
ldmia r4!, { r12, r14 } @ r12, r14 = Ri0, Ri1
qadd r6, r6, r5 @ round, scale, saturate and pack
qadd r7, r7, r5 @ Li0+Ri0 to So0, Li1+Ri1 to So1
qadd r12, r12, r5 @
qadd r14, r14, r5 @
mov r6, r6, asr r1 @
mov r7, r7, asr r1 @
mov r12, r12, asr r1 @
mov r14, r14, asr r1 @
ssat r6, #16, r6 @
ssat r12, #16, r12 @
ssat r7, #16, r7 @
ssat r14, #16, r14 @
pkhbt r6, r6, r12, asl #16 @
pkhbt r7, r7, r14, asl #16 @
subs r0, r0, #2 @
stmia r3!, { r6, r7 } @ store So0, So1
bgt 1b @
@
ldmltfd sp!, { r4-r7, pc } @ if count was even, we're done
@
2: @
ldr r6, [r2] @ r6 = Li
ldr r12, [r4] @ r12 = Ri
qadd r6, r6, r5 @ round, scale, saturate
qadd r12, r12, r5 @ and pack Li+Ri to So
mov r6, r6, asr r1 @
mov r12, r12, asr r1 @
ssat r6, #16, r6 @
ssat r12, #16, r12 @
pkhbt r6, r6, r12, asl #16 @
str r6, [r3] @ store So
@
ldmfd sp!, { r4-r7, pc } @
.size sample_output_stereo, .-sample_output_stereo