rockbox/apps/dsp_arm.S
Daniel Stenberg 2acc0ac542 Updated our source code header to explicitly mention that we are GPL v2 or
later. We still need to hunt down snippets used that are not. 1324 modified
files...
http://www.rockbox.org/mail/archive/rockbox-dev-archive-2008-06/0060.shtml


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@17847 a1c6a512-1295-4272-9138-f99709370657
2008-06-28 18:10:04 +00:00

383 lines
16 KiB
ArmAsm

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2006-2007 Thom Johansen
*
* 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 channels_process_sound_chan_mono(int count, int32_t *buf[])
*
* NOTE: The following code processes two samples at once. When count is odd,
* there is an additional obsolete sample processed, which will not be
* used by the calling functions.
*/
.section .icode, "ax", %progbits
.align 2
.global channels_process_sound_chan_mono
.type channels_process_sound_chan_mono, %function
channels_process_sound_chan_mono:
@ input: r0 = count, r1 = buf
stmfd sp!, {r4-r6, lr}
ldmia r1, {r2-r3} @ r4 = buf[0], r5 = buf[1]
.monoloop:
ldmia r2, {r4-r5}
ldmia r3, {r6,lr}
mov r4, r4, asr #1 @ r4 = r4/2
add r4, r4, r6, asr #1 @ r4 = r4 + r6/2 = (buf[0]+buf[1])/2
mov r5, r5, asr #1 @ r5 = r5/2
add r5, r5, lr, asr #1 @ r5 = r5 + lr/2 = (buf[0]+buf[1])/2
stmia r2!, {r4-r5}
stmia r3!, {r4-r5}
subs r0, r0, #2
bgt .monoloop
ldmfd sp!, {r4-r6, pc}
.monoend:
.size channels_process_sound_chan_mono,.monoend-channels_process_sound_chan_mono
/****************************************************************************
* void channels_process_sound_chan_karaoke(int count, int32_t *buf[])
* NOTE: The following code processes two samples at once. When count is odd,
* there is an additional obsolete sample processed, which will not be
* used by the calling functions.
*/
.section .icode, "ax", %progbits
.align 2
.global channels_process_sound_chan_karaoke
.type channels_process_sound_chan_karaoke, %function
channels_process_sound_chan_karaoke:
@ input: r0 = count, r1 = buf
stmfd sp!, {r4-r6, lr}
ldmia r1, {r2-r3} @ r4 = buf[0], r5 = buf[1]
.karaokeloop:
ldmia r2, {r4-r5}
ldmia r3, {r6,lr}
mov r6, r6, asr #1 @ r6 = r6/2
rsb r4, r6, r4, asr #1 @ r4 = -r6 + r4/2 = (buf[0]-buf[1])/2
rsb r6, r4, #0 @ r6 = -r4
mov lr, lr, asr #1 @ lr = lr/2
rsb r5, lr, r5, asr #1 @ r5 = -lr + r5/2 = (buf[0]-buf[1])/2
rsb lr, r5, #0 @ lr = -r5
stmia r2!, {r4-r5}
stmia r3!, {r6,lr}
subs r0, r0, #2
bgt .karaokeloop
ldmfd sp!, {r4-r6, pc}
.karaokeend:
.size channels_process_sound_chan_karaoke,.karaokeend-channels_process_sound_chan_karaoke
/****************************************************************************
* void sample_output_mono(int count, struct dsp_data *data,
int32_t *src[], int16_t *dst)
* NOTE: The following code processes two samples at once. When count is odd,
* there is an additional obsolete sample processed, which will not be
* used by the calling functions.
*/
.section .icode, "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-r9, lr}
ldr r4, [r2] @ r4 = src[0]
ldr r5, [r1] @ lr = data->output_scale
sub r1, r5, #1 @ r1 = r5-1
mov r2, #1
mov r2, r2, asl r1 @ r2 = 1<<r1 = 1 << (scale-1)
mvn r1, #0x8000 @ r1 needed for clipping
mov r8, #0xff00
orr r8, r8, #0xff @ r8 needed for masking
.somloop:
ldmia r4!, {r6-r7}
add r6, r6, r2
mov r6, r6, asr r5 @ r6 = (r6 + 1<<(scale-1)) >> scale
mov lr, r6, asr #15
teq lr, lr, asr #31
eorne r6, r1, lr, asr #31 @ Clip (-32768...+32767)
add r7, r7, r2
mov r7, r7, asr r5 @ r7 = (r7 + 1<<(scale-1)) >> scale
mov lr, r7, asr #15
teq lr, lr, asr #31
eorne r7, r1, lr, asr #31 @ Clip (-32768...+32767)
and r6, r6, r8
orr r6, r6, r6, asl #16 @ pack first 2 halfwords into 1 word
and r7, r7, r8
orr r7, r7, r7, asl #16 @ pack last 2 halfwords into 1 word
stmia r3!, {r6-r7}
subs r0, r0, #2
bgt .somloop
ldmfd sp!, {r4-r9, pc}
.somend:
.size sample_output_mono,.somend-sample_output_mono
/****************************************************************************
* void sample_output_stereo(int count, struct dsp_data *data,
int32_t *src[], int16_t *dst)
* NOTE: The following code processes two samples at once. When count is odd,
* there is an additional obsolete sample processed, which will not be
* used by the calling functions.
*/
.section .icode, "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-r11, lr}
ldmia r2, {r4-r5} @ r4 = src[0], r5 = src[1]
ldr r6, [r1] @ r6 = data->output_scale
sub r1, r6, #1 @ r1 = r6-1
mov r2, #1
mov r2, r2, asl r1 @ r2 = 1<<r1 = 1 << (scale-1)
mvn r1, #0x8000 @ r1 needed for clipping
mov r11, #0xff00
orr r11, r11, #0xff @ r11 needed for masking
.sosloop:
ldmia r4!, {r7-r8}
add r7, r7, r2
mov r7, r7, asr r6 @ r7 = (r7 + 1<<(scale-1)) >> scale
mov lr, r7, asr #15
teq lr, lr, asr #31
eorne r7, r1, lr, asr #31 @ Clip (-32768...+32767)
add r8, r8, r2
mov r8, r8, asr r6 @ r8 = (r8 + 1<<(scale-1)) >> scale
mov lr, r8, asr #15
teq lr, lr, asr #31
eorne r8, r1, lr, asr #31 @ Clip (-32768...+32767)
ldmia r5!, {r9-r10}
add r9, r9, r2
mov r9, r9, asr r6 @ r9 = (r9 + 1<<(scale-1)) >> scale
mov lr, r9, asr #15
teq lr, lr, asr #31
eorne r9, r1, lr, asr #31 @ Clip (-32768...+32767)
add r10, r10, r2
mov r10, r10, asr r6 @ r10 = (r10 + 1<<(scale-1)) >> scale
mov lr, r10, asr #15
teq lr, lr, asr #31
eorne r10, r1, lr, asr #31 @ Clip (-32768...+32767)
and r7, r7, r11
orr r9, r7, r9, asl #16 @ pack first 2 halfwords into 1 word
and r8, r8, r11
orr r10, r8, r10, asl #16 @ pack last 2 halfwords into 1 word
stmia r3!, {r9-r10}
subs r0, r0, #2
bgt .sosloop
ldmfd sp!, {r4-r11, pc}
.sosend:
.size sample_output_stereo,.sosend-sample_output_stereo
/****************************************************************************
* void apply_crossfeed(int count, int32_t* src[])
*/
.section .text
.global apply_crossfeed
apply_crossfeed:
@ unfortunately, we ended up in a bit of a register squeeze here, and need
@ to keep the count on the stack :/
stmdb sp!, { r4-r11, lr } @ stack modified regs
ldmia r1, { r2-r3 } @ r2 = src[0], r3 = src[1]
ldr r1, =crossfeed_data
ldmia r1!, { r4-r11 } @ load direct gain and filter data
add r12, r1, #13*4*2 @ calculate end of delay
stmdb sp!, { r0, r12 } @ stack count and end of delay adr
ldr r0, [r1, #13*4*2] @ fetch current delay line address
/* Register usage in loop:
* r0 = &delay[index][0], r1 = accumulator high, r2 = src[0], r3 = src[1],
* r4 = direct gain, r5-r7 = b0, b1, a1 (filter coefs),
* r8-r11 = filter history, r12 = temp, r14 = accumulator low
*/
.cfloop:
smull r14, r1, r6, r8 @ acc = b1*dr[n - 1]
smlal r14, r1, r7, r9 @ acc += a1*y_l[n - 1]
ldr r8, [r0, #4] @ r8 = dr[n]
smlal r14, r1, r5, r8 @ acc += b0*dr[n]
mov r9, r1, lsl #1 @ fix format for filter history
ldr r12, [r2] @ load left input
smlal r14, r1, r4, r12 @ acc += gain*x_l[n]
mov r1, r1, lsl #1 @ fix format
str r1, [r2], #4 @ save result
smull r14, r1, r6, r10 @ acc = b1*dl[n - 1]
smlal r14, r1, r7, r11 @ acc += a1*y_r[n - 1]
ldr r10, [r0] @ r10 = dl[n]
str r12, [r0], #4 @ save left input to delay line
smlal r14, r1, r5, r10 @ acc += b0*dl[n]
mov r11, r1, lsl #1 @ fix format for filter history
ldr r12, [r3] @ load right input
smlal r14, r1, r4, r12 @ acc += gain*x_r[n]
str r12, [r0], #4 @ save right input to delay line
mov r1, r1, lsl #1 @ fix format
str r1, [r3], #4 @ save result
ldr r12, [sp, #4] @ fetch delay line end addr from stack
cmp r0, r12 @ need to wrap to start of delay?
subeq r0, r0, #13*4*2 @ wrap back delay line ptr to start
ldr r1, [sp] @ fetch count from stack
subs r1, r1, #1 @ are we finished?
strne r1, [sp] @ nope, save count back to stack
bne .cfloop
@ save data back to struct
ldr r12, =crossfeed_data + 4*4
stmia r12, { r8-r11 } @ save filter history
str r0, [r12, #30*4] @ save delay line index
add sp, sp, #8 @ remove temp variables from stack
ldmia sp!, { r4-r11, pc }
.cfend:
.size apply_crossfeed,.cfend-apply_crossfeed
/****************************************************************************
* int dsp_downsample(int count, struct dsp_data *data,
* in32_t *src[], int32_t *dst[])
*/
.section .text
.global dsp_downsample
dsp_downsample:
stmdb sp!, { r4-r11, lr } @ stack modified regs
ldmib r1, { r5-r6 } @ r5 = num_channels,r6 = resample_data.delta
sub r5, r5, #1 @ pre-decrement num_channels for use
add r4, r1, #12 @ r4 = &resample_data.phase
mov r12, #0xff
orr r12, r12, #0xff00 @ r12 = 0xffff
.dschannel_loop:
ldr r1, [r4] @ r1 = resample_data.phase
ldr r7, [r2, r5, lsl #2] @ r7 = s = src[ch - 1]
ldr r8, [r3, r5, lsl #2] @ r8 = d = dst[ch - 1]
add r9, r4, #4 @ r9 = &last_sample[0]
ldr r10, [r9, r5, lsl #2] @ r10 = last_sample[ch - 1]
sub r11, r0, #1
ldr r14, [r7, r11, lsl #2] @ load last sample in s[] ...
str r14, [r9, r5, lsl #2] @ and write as next frame's last_sample
movs r9, r1, lsr #16 @ r9 = pos = phase >> 16
ldreq r11, [r7] @ if pos = 0, load src[0] and jump into loop
beq .dsuse_last_start
cmp r9, r0 @ if pos >= count, we're already done
bge .dsloop_skip
@ Register usage in loop:
@ r0 = count, r1 = phase, r4 = &resample_data.phase, r5 = cur_channel,
@ r6 = delta, r7 = s, r8 = d, r9 = pos, r10 = s[pos - 1], r11 = s[pos]
.dsloop:
add r9, r7, r9, lsl #2 @ r9 = &s[pos]
ldmda r9, { r10, r11 } @ r10 = s[pos - 1], r11 = s[pos]
.dsuse_last_start:
sub r11, r11, r10 @ r11 = diff = s[pos] - s[pos - 1]
@ keep frac in lower bits to take advantage of multiplier early termination
and r9, r1, r12 @ frac = phase & 0xffff
smull r9, r14, r11, r9
add r10, r10, r14, lsl #16
add r10, r10, r9, lsr #16 @ r10 = out = s[pos - 1] + frac*diff
str r10, [r8], #4 @ *d++ = out
add r1, r1, r6 @ phase += delta
mov r9, r1, lsr #16 @ pos = phase >> 16
cmp r9, r0 @ pos < count?
blt .dsloop @ yup, do more samples
.dsloop_skip:
subs r5, r5, #1
bpl .dschannel_loop @ if (--ch) >= 0, do another channel
sub r1, r1, r0, lsl #16 @ wrap phase back to start
str r1, [r4] @ store back
ldr r1, [r3] @ r1 = &dst[0]
sub r8, r8, r1 @ dst - &dst[0]
mov r0, r8, lsr #2 @ convert bytes->samples
ldmia sp!, { r4-r11, pc } @ ... and we're out
.dsend:
.size dsp_downsample,.dsend-dsp_downsample
/****************************************************************************
* int dsp_upsample(int count, struct dsp_data *dsp,
* in32_t *src[], int32_t *dst[])
*/
.section .text
.global dsp_upsample
dsp_upsample:
stmdb sp!, { r4-r11, lr } @ stack modified regs
ldmib r1, { r5-r6 } @ r5 = num_channels,r6 = resample_data.delta
sub r5, r5, #1 @ pre-decrement num_channels for use
add r4, r1, #12 @ r4 = &resample_data.phase
stmdb sp!, { r0, r4 } @ stack count and &resample_data.phase
.uschannel_loop:
ldr r12, [r4] @ r12 = resample_data.phase
mov r1, r12, ror #16 @ swap halfword positions, we'll use carry
@ to detect pos increments
ldr r7, [r2, r5, lsl #2] @ r7 = s = src[ch - 1]
ldr r8, [r3, r5, lsl #2] @ r8 = d = dst[ch - 1]
add r9, r4, #4 @ r9 = &last_sample[0]
ldr r10, [r9, r5, lsl #2] @ r10 = last_sample[ch - 1]
sub r11, r0, #1
ldr r14, [r7, r11, lsl #2] @ load last sample in s[] ...
str r14, [r9, r5, lsl #2] @ and write as next frame's last_sample
add r9, r7, r0, lsl #2 @ r9 = src_end = &src[count]
movs r14, r12, lsr #16 @ pos = resample_data.phase >> 16
beq .usstart_0 @ pos = 0
cmp r14, r0 @ if pos >= count, we're already done
bge .usloop_skip
add r7, r7, r14, lsl #2 @ r7 = &s[pos]
ldr r10, [r7, #-4] @ r11 = s[pos - 1]
b .usstart_0
@ Register usage in loop:
@ r0 = count, r1 = phase, r4 = &resample_data.phase, r5 = cur_channel,
@ r6 = delta, r7 = s, r8 = d, r9 = src_end, r10 = s[pos - 1], r11 = s[pos]
.usloop_1:
mov r10, r11 @ r10 = previous sample
.usstart_0:
ldr r11, [r7], #4 @ r11 = next sample
sub r0, r11, r10 @ r0 = s[pos] - s[pos - 1]
.usloop_0:
mov r4, r1, lsr #16 @ r4 = frac = phase >> 16
smull r12, r14, r4, r0
add r14, r10, r14, lsl #16
add r14, r14, r12, lsr #16 @ r14 = out = s[pos - 1] + frac*diff
str r14, [r8], #4 @ *d++ = out
adds r1, r1, r6, lsl #16 @ phase += delta << 16
bcc .usloop_0 @ if carry is set, pos is incremented
cmp r7, r9 @ if s < src_end, do another sample
blo .usloop_1
.usloop_skip:
subs r5, r5, #1
ldmia sp, { r0, r4 } @ reload count and &resample_data.phase
bpl .uschannel_loop @ if (--ch) >= 0, do another channel
mov r1, r1, ror #16 @ wrap phase back to start of next frame
str r1, [r4] @ store back
ldr r1, [r3] @ r1 = &dst[0]
sub r8, r8, r1 @ dst - &dst[0]
mov r0, r8, lsr #2 @ convert bytes->samples
add sp, sp, #8 @ adjust stack for temp variables
ldmia sp!, { r4-r11, pc } @ ... and we're out
.usend:
.size dsp_upsample,.usend-dsp_upsample