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|
/*
libdemac - A Monkey's Audio decoder
$Id$
Copyright (C) Dave Chapman 2007
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 program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110, USA
*/
.section .text,"ax",%progbits
.align 2
.global predictor_decode_stereo
.type predictor_decode_stereo,%function
/* NOTE: The following need to be kept in sync with parser.h */
#define HISTORY_SIZE 512
#define YDELAYA 200
#define YDELAYB 168
#define XDELAYA 136
#define XDELAYB 104
#define YADAPTCOEFFSA 72
#define XADAPTCOEFFSA 56
#define YADAPTCOEFFSB 40
#define XADAPTCOEFFSB 20
/* struct predictor_t members: */
#define buf 0 /* int32_t* buf */
#define YlastA 4 /* int32_t YlastA; */
#define XlastA 8 /* int32_t XlastA; */
#define YfilterB 12 /* int32_t YfilterB; */
#define XfilterA 16 /* int32_t XfilterA; */
#define XfilterB 20 /* int32_t XfilterB; */
#define YfilterA 24 /* int32_t YfilterA; */
#define YcoeffsA 28 /* int32_t YcoeffsA[4]; */
#define XcoeffsA 44 /* int32_t XcoeffsA[4]; */
#define YcoeffsB 60 /* int32_t YcoeffsB[5]; */
#define XcoeffsB 80 /* int32_t XcoeffsB[5]; */
#define historybuffer 100 /* int32_t historybuffer[] */
@ Register usage:
@
@ r0-r11 - scratch
@ r12 - struct predictor_t* p
@ r14 - int32_t* p->buf
@ void predictor_decode_stereo(struct predictor_t* p,
@ int32_t* decoded0,
@ int32_t* decoded1,
@ int count)
predictor_decode_stereo:
stmdb sp!, {r1-r11, lr}
@ r1 (decoded0) is [sp]
@ r2 (decoded1) is [sp, #4]
@ r3 (count) is [sp, #8]
mov r12, r0 @ r12 := p
ldr r14, [r0] @ r14 := p->buf
loop:
@@@@@@@@@@@@@@@@@@@@@@@@@@@ PREDICTOR Y
@ Predictor Y, Filter A
ldr r10, [r12, #YlastA] @ r10 := p->YlastA
add r11, r14, #YDELAYA-12 @ r11 := &p->buf[YDELAYA-3]
ldmia r11, { r2 - r4 } @ r2 := p->buf[YDELAYA-3]
@ r3 := p->buf[YDELAYA-2]
@ r4 := p->buf[YDELAYA-1]
subs r4, r10, r4 @ r4 := r10 - r4
add r1, r12, #YcoeffsA
ldmia r1, {r6 - r9} @ r6 := p->YcoeffsA[0]
@ r7 := p->YcoeffsA[1]
@ r8 := p->YcoeffsA[2]
@ r9 := p->YcoeffsA[3]
mul r0, r10, r6 @ r0 := p->buf[YDELAYA] * p->YcoeffsA[0]
mla r0, r4, r7, r0 @ r0 += p->buf[YDELAYA-1] * p->YcoeffsA[1]
mla r0, r3, r8, r0 @ r0 += p->buf[YDELAYA-2] * p->YcoeffsA[2]
mla r0, r2, r9, r0 @ r0 += p->buf[YDELAYA-3] * p->YcoeffsA[3]
add r11, r14, #YDELAYA-4
stmia r11, { r4, r10 } @ p->buf[YDELAYA-1] = r4
@ p->buf[YDELAYA] = r10
@ flags were set above, in the subs instruction
mvngt r4, #0
movlt r4, #1 @ r4 := SIGN(r4) (see .c for SIGN macro)
cmp r10, #0
mvngt r10, #0
movlt r10, #1 @ r10 := SIGN(r10) (see .c for SIGN macro)
add r1, r14, #YADAPTCOEFFSA-4
stmia r1, {r4, r10} @ p->buf[YADAPTCOEFFSA-1] := r4
@ p->buf[YADAPTCOEFFSA] := r10
@ NOTE: r0 now contains predictionA - don't overwrite.
@ Predictor Y, Filter B
add r2, r12, #YfilterB
ldmia r2, {r2, r11} @ r2 := p->YfilterB
@ r11 := p->XfilterA
rsb r2, r2, r2, lsl #5 @ r2 := r2 * 32 - r2 ( == r2*31)
sub r10, r11, r2, asr #5 @ r10 (p->buf[YDELAYB]) := r11 - (r2 >> 5)
str r11, [r12, #YfilterB] @ p->YfilterB := r11 (p->XfilterA)
add r11, r14, #YDELAYB-16 @ r11 := &p->buf[YDELAYB-4]
ldmia r11, { r2 - r5 } @ r2 := p->buf[YDELAYB-4]
@ r3 := p->buf[YDELAYB-3]
@ r4 := p->buf[YDELAYB-2]
@ r5 := p->buf[YDELAYB-1]
subs r5, r10, r5 @ r5 := r10 - r5
add r1, r12, #YcoeffsB
ldmia r1, {r6,r7,r8,r9,r11} @ r6 := p->YcoeffsB[0]
@ r7 := p->YcoeffsB[1]
@ r8 := p->YcoeffsB[2]
@ r9 := p->YcoeffsB[3]
@ r11 := p->YcoeffsB[4]
mul r1, r10, r6 @ r1 := p->buf[YDELAYB] * p->YcoeffsB[0]
mla r1, r5, r7, r1 @ r1 += p->buf[YDELAYB-1] * p->YcoeffsB[1]
mla r1, r4, r8, r1 @ r1 += p->buf[YDELAYB-2] * p->YcoeffsB[2]
mla r1, r3, r9, r1 @ r1 += p->buf[YDELAYB-3] * p->YcoeffsB[3]
mla r1, r2, r11, r1 @ r1 += p->buf[YDELAYB-4] * p->YcoeffsB[4]
add r2, r14, #YDELAYB-4 @ r2 := &p->buf[YDELAYB-1]
stmia r2, { r5, r10 } @ p->buf[YDELAYB-1] = r5
@ p->buf[YDELAYB] = r10
@ flags were set above, in the subs instruction
mvngt r5, #0
movlt r5, #1 @ r5 := SIGN(r5) (see .c for SIGN macro)
cmp r10, #0
mvngt r10, #0
movlt r10, #1 @ r10 := SIGN(r10) (see .c for SIGN macro)
add r2, r14, #YADAPTCOEFFSB-4
stmia r2, {r5, r10} @ p->buf[YADAPTCOEFFSB-1] := r5
@ p->buf[YADAPTCOEFFSB] := r10
@ r0 still contains predictionA
@ r1 contains predictionB
@ Finish Predictor Y
ldr r2, [sp] @ r2 := decoded0
add r0, r0, r1, asr #1 @ r0 := r0 + (r1 >> 1)
ldr r3, [r2] @ r3 := *decoded0
add r1, r3, r0, asr #10 @ r1 := r3 + (r0 >> 10)
str r1, [r12, #YlastA] @ p->YlastA := r1
ldr r4, [r12, #YfilterA] @ r4 := p->YfilterA
rsb r4, r4, r4, lsl #5 @ r4 := r4 * 32 - r4 ( == r4*31)
add r1, r1, r4, asr #5 @ r1 := r1 + (r4 >> 5)
str r1, [r12, #YfilterA] @ p->YfilterA := r1
@ r1 contains p->YfilterA
@ r2 contains decoded0
@ r3 contains *decoded0
@ r6, r7, r8, r9, r11 contain p->YcoeffsB[0..4]
@ r5, r10 contain p->buf[YADAPTCOEFFSB-1] and p->buf[YADAPTCOEFFSB]
cmp r3, #0
stmia r2!, {r1} @ *(decoded0++) := r1 (p->YfilterA)
str r2, [sp] @ save decoded0
beq 2f
add r1, r14, #YADAPTCOEFFSB-16
ldmia r1, { r2, r3, r4 } @ r2 := p->buf[YADAPTCOEFFSB-4]
@ r3 := p->buf[YADAPTCOEFFSB-3]
@ r4 := p->buf[YADAPTCOEFFSB-2]
blt 1f
@ *decoded0 > 0
sub r6, r6, r10 @ r6 := p->YcoeffsB[0] - p->buf[YADAPTCOEFFSB]
sub r7, r7, r5 @ r7 := p->YcoeffsB[1] - p->buf[YADAPTCOEFFSB-1]
sub r8, r8, r4 @ r8 := p->YcoeffsB[2] - p->buf[YADAPTCOEFFSB-2]
sub r9, r9, r3 @ r9 := p->YcoeffsB[3] - p->buf[YADAPTCOEFFSB-3]
sub r11, r11, r2 @ r11 := p->YcoeffsB[4] - p->buf[YADAPTCOEFFSB-4]
add r0, r12, #YcoeffsB
stmia r0, {r6,r7,r8,r9,r11} @ Save p->YcoeffsB[]
add r1, r12, #YcoeffsA
ldmia r1, { r2-r5 } @ r2 := p->YcoeffsA[0]
@ r3 := p->YcoeffsA[1]
@ r4 := p->YcoeffsA[2]
@ r5 := p->YcoeffsA[3]
add r0, r14, #YADAPTCOEFFSA-12
ldmia r0, { r6-r9} @ r6 := p->buf[YADAPTCOEFFSA-3]
@ r7 := p->buf[YADAPTCOEFFSA-2]
@ r8 := p->buf[YADAPTCOEFFSA-1]
@ r9 := p->buf[YADAPTCOEFFSA]
sub r2, r2, r9 @ r2 := p->YcoeffsA[0] - p->buf[YADAPTCOEFFSA]
sub r3, r3, r8 @ r3 := p->YcoeffsA[1] - p->buf[YADAPTCOEFFSA-1]
sub r4, r4, r7 @ r4 := p->YcoeffsA[2] - p->buf[YADAPTCOEFFSA-2]
sub r5, r5, r6 @ r5 := p->YcoeffsA[3] - p->buf[YADAPTCOEFFSA-3]
stmia r1, {r2-r5} @ Save p->YcoeffsA
b 2f
1: @ *decoded0 < 0
add r6, r6, r10 @ r6 := p->YcoeffsB[0] + p->buf[YADAPTCOEFFSB]
add r7, r7, r5 @ r7 := p->YcoeffsB[1] + p->buf[YADAPTCOEFFSB-1]
add r8, r8, r4 @ r8 := p->YcoeffsB[2] + p->buf[YADAPTCOEFFSB-2]
add r9, r9, r3 @ r9 := p->YcoeffsB[3] + p->buf[YADAPTCOEFFSB-3]
add r11, r11, r2 @ r11 := p->YcoeffsB[4] + p->buf[YADAPTCOEFFSB-4]
add r0, r12, #YcoeffsB
stmia r0, {r6,r7,r8,r9,r11} @ Save p->YcoeffsB[]
add r1, r12, #YcoeffsA
ldmia r1, { r2-r5 } @ r2 := p->YcoeffsA[0]
@ r3 := p->YcoeffsA[1]
@ r4 := p->YcoeffsA[2]
@ r5 := p->YcoeffsA[3]
add r0, r14, #YADAPTCOEFFSA-12
ldmia r0, { r6-r9} @ r6 := p->buf[YADAPTCOEFFSA-3]
@ r7 := p->buf[YADAPTCOEFFSA-2]
@ r8 := p->buf[YADAPTCOEFFSA-1]
@ r9 := p->buf[YADAPTCOEFFSA]
add r2, r2, r9 @ r2 := p->YcoeffsA[0] + p->buf[YADAPTCOEFFSA]
add r3, r3, r8 @ r3 := p->YcoeffsA[1] + p->buf[YADAPTCOEFFSA-1]
add r4, r4, r7 @ r4 := p->YcoeffsA[2] + p->buf[YADAPTCOEFFSA-2]
add r5, r5, r6 @ r5 := p->YcoeffsA[3] + p->buf[YADAPTCOEFFSA-3]
stmia r1, {r2-r5} @ Save p->YcoeffsA
2:
@@@@@@@@@@@@@@@@@@@@@@@@@@@ PREDICTOR X
@ Predictor X, Filter A
ldr r10, [r12, #XlastA] @ r10 := p->XlastA
add r11, r14, #XDELAYA-12 @ r11 := &p->buf[XDELAYA-3]
ldmia r11, { r2 - r4 } @ r2 := p->buf[XDELAYA-3]
@ r3 := p->buf[XDELAYA-2]
@ r4 := p->buf[XDELAYA-1]
subs r4, r10, r4 @ r4 := r10 - r4
add r1, r12, #XcoeffsA
ldmia r1, {r6 - r9} @ r6 := p->XcoeffsA[0]
@ r7 := p->XcoeffsA[1]
@ r8 := p->XcoeffsA[2]
@ r9 := p->XcoeffsA[3]
mul r0, r10, r6 @ r0 := p->buf[XDELAYA] * p->XcoeffsA[0]
mla r0, r4, r7, r0 @ r0 += p->buf[XDELAYA-1] * p->XcoeffsA[1]
mla r0, r3, r8, r0 @ r0 += p->buf[XDELAYA-2] * p->XcoeffsA[2]
mla r0, r2, r9, r0 @ r0 += p->buf[XDELAYA-3] * p->XcoeffsA[3]
add r11, r14, #XDELAYA-4
stmia r11, { r4, r10 } @ p->buf[XDELAYA-1] = r4
@ p->buf[XDELAYA] = r10
@ flags were set above, in the subs instruction
mvngt r4, #0
movlt r4, #1 @ r4 := SIGN(r4) (see .c for SIGN macro)
cmp r10, #0
mvngt r10, #0
movlt r10, #1 @ r10 := SIGN(r10) (see .c for SIGN macro)
add r1, r14, #XADAPTCOEFFSA-4
stmia r1, {r4, r10} @ p->buf[XADAPTCOEFFSA-1] := r4
@ p->buf[XADAPTCOEFFSA] := r10
@ NOTE: r0 now contains predictionA - don't overwrite.
@ Predictor X, Filter B
add r2, r12, #XfilterB
ldmia r2, {r2, r11} @ r2 := p->XfilterB
@ r11 := p->YfilterA
rsb r2, r2, r2, lsl #5 @ r2 := r2 * 32 - r2 ( == r2*31)
sub r10, r11, r2, asr #5 @ r10 (p->buf[XDELAYB]) := r11 - (r2 >> 5)
str r11, [r12, #XfilterB] @ p->XfilterB := r11 (p->YfilterA)
add r11, r14, #XDELAYB-16 @ r11 := &p->buf[XDELAYB-4]
ldmia r11, { r2 - r5 } @ r2 := p->buf[XDELAYB-4]
@ r3 := p->buf[XDELAYB-3]
@ r4 := p->buf[XDELAYB-2]
@ r5 := p->buf[XDELAYB-1]
subs r5, r10, r5 @ r5 := r10 - r5
add r1, r12, #XcoeffsB
ldmia r1, {r6,r7,r8,r9,r11} @ r6 := p->XcoeffsB[0]
@ r7 := p->XcoeffsB[1]
@ r8 := p->XcoeffsB[2]
@ r9 := p->XcoeffsB[3]
@ r11 := p->XcoeffsB[4]
mul r1, r10, r6 @ r1 := p->buf[XDELAYB] * p->XcoeffsB[0]
mla r1, r5, r7, r1 @ r1 += p->buf[XDELAYB-1] * p->XcoeffsB[1]
mla r1, r4, r8, r1 @ r1 += p->buf[XDELAYB-2] * p->XcoeffsB[2]
mla r1, r3, r9, r1 @ r1 += p->buf[XDELAYB-3] * p->XcoeffsB[3]
mla r1, r2, r11, r1 @ r1 += p->buf[XDELAYB-4] * p->XcoeffsB[4]
add r2, r14, #XDELAYB-4 @ r2 := &p->buf[XDELAYB-1]
stmia r2, { r5, r10 } @ p->buf[XDELAYB-1] = r5
@ p->buf[XDELAYB] = r10
@ flags were set above, in the subs instruction
mvngt r5, #0
movlt r5, #1 @ r5 := SIGN(r5) (see .c for SIGN macro)
cmp r10, #0
mvngt r10, #0
movlt r10, #1 @ r10 := SIGN(r10) (see .c for SIGN macro)
add r2, r14, #XADAPTCOEFFSB-4
stmia r2, {r5, r10} @ p->buf[XADAPTCOEFFSB-1] := r5
@ p->buf[XADAPTCOEFFSB] := r10
@ r0 still contains predictionA
@ r1 contains predictionB
@ Finish Predictor X
ldr r2, [sp, #4] @ r2 := decoded1
add r0, r0, r1, asr #1 @ r0 := r0 + (r1 >> 1)
ldr r3, [r2] @ r3 := *decoded1
add r1, r3, r0, asr #10 @ r1 := r3 + (r0 >> 10)
str r1, [r12, #XlastA] @ p->XlastA := r1
ldr r4, [r12, #XfilterA] @ r4 := p->XfilterA
rsb r4, r4, r4, lsl #5 @ r4 := r4 * 32 - r4 ( == r4*31)
add r1, r1, r4, asr #5 @ r1 := r1 + (r4 >> 5)
str r1, [r12, #XfilterA] @ p->XfilterA := r1
@ r1 contains p->XfilterA
@ r2 contains decoded1
@ r3 contains *decoded1
@ r6, r7, r8, r9, r11 contain p->XcoeffsB[0..4]
@ r5, r10 contain p->buf[XADAPTCOEFFSB-1] and p->buf[XADAPTCOEFFSB]
cmp r3, #0
stmia r2!, {r1} @ *(decoded1++) := r1 (p->XfilterA)
str r2, [sp, #4] @ save decoded1
beq 2f
add r1, r14, #XADAPTCOEFFSB-16
ldmia r1, { r2, r3, r4 } @ r2 := p->buf[XADAPTCOEFFSB-4]
@ r3 := p->buf[XADAPTCOEFFSB-3]
@ r4 := p->buf[XADAPTCOEFFSB-2]
blt 1f
@ *decoded1 > 0
sub r6, r6, r10 @ r6 := p->XcoeffsB[0] - p->buf[XADAPTCOEFFSB]
sub r7, r7, r5 @ r7 := p->XcoeffsB[1] - p->buf[XADAPTCOEFFSB-1]
sub r8, r8, r4 @ r8 := p->XcoeffsB[2] - p->buf[XADAPTCOEFFSB-2]
sub r9, r9, r3 @ r9 := p->XcoeffsB[3] - p->buf[XADAPTCOEFFSB-3]
sub r11, r11, r2 @ r11 := p->XcoeffsB[4] - p->buf[XADAPTCOEFFSB-4]
add r0, r12, #XcoeffsB
stmia r0, {r6,r7,r8,r9,r11} @ Save p->XcoeffsB[]
add r1, r12, #XcoeffsA
ldmia r1, { r2-r5 } @ r2 := p->XcoeffsA[0]
@ r3 := p->XcoeffsA[1]
@ r4 := p->XcoeffsA[2]
@ r5 := p->XcoeffsA[3]
add r0, r14, #XADAPTCOEFFSA-12
ldmia r0, { r6-r9} @ r6 := p->buf[XADAPTCOEFFSA-3]
@ r7 := p->buf[XADAPTCOEFFSA-2]
@ r8 := p->buf[XADAPTCOEFFSA-1]
@ r9 := p->buf[XADAPTCOEFFSA]
sub r2, r2, r9 @ r2 := p->XcoeffsA[0] - p->buf[XADAPTCOEFFSA]
sub r3, r3, r8 @ r3 := p->XcoeffsA[1] - p->buf[XADAPTCOEFFSA-1]
sub r4, r4, r7 @ r4 := p->XcoeffsA[2] - p->buf[XADAPTCOEFFSA-2]
sub r5, r5, r6 @ r5 := p->XcoeffsA[3] - p->buf[XADAPTCOEFFSA-3]
stmia r1, {r2-r5} @ Save p->XcoeffsA
b 2f
1: @ *decoded1 < 0
add r6, r6, r10 @ r6 := p->XcoeffsB[0] + p->buf[XADAPTCOEFFSB]
add r7, r7, r5 @ r7 := p->XcoeffsB[1] + p->buf[XADAPTCOEFFSB-1]
add r8, r8, r4 @ r8 := p->XcoeffsB[2] + p->buf[XADAPTCOEFFSB-2]
add r9, r9, r3 @ r9 := p->XcoeffsB[3] + p->buf[XADAPTCOEFFSB-3]
add r11, r11, r2 @ r11 := p->XcoeffsB[4] + p->buf[XADAPTCOEFFSB-4]
add r0, r12, #XcoeffsB
stmia r0, {r6,r7,r8,r9,r11} @ Save p->XcoeffsB[]
add r1, r12, #XcoeffsA
ldmia r1, { r2-r5 } @ r2 := p->XcoeffsA[0]
@ r3 := p->XcoeffsA[1]
@ r4 := p->XcoeffsA[2]
@ r5 := p->XcoeffsA[3]
add r0, r14, #XADAPTCOEFFSA-12
ldmia r0, { r6-r9} @ r6 := p->buf[XADAPTCOEFFSA-3]
@ r7 := p->buf[XADAPTCOEFFSA-2]
@ r8 := p->buf[XADAPTCOEFFSA-1]
@ r9 := p->buf[XADAPTCOEFFSA]
add r2, r2, r9 @ r2 := p->XcoeffsA[0] + p->buf[XADAPTCOEFFSA]
add r3, r3, r8 @ r3 := p->XcoeffsA[1] + p->buf[XADAPTCOEFFSA-1]
add r4, r4, r7 @ r4 := p->XcoeffsA[2] + p->buf[XADAPTCOEFFSA-2]
add r5, r5, r6 @ r5 := p->XcoeffsA[3] + p->buf[XADAPTCOEFFSA-3]
stmia r1, {r2-r5} @ Save p->XcoeffsA
2:
@@@@@@@@@@@@@@@@@@@@@@@@@@@ COMMON
add r14, r14, #4 @ p->buf++
add r11, r12, #historybuffer @ r11 := &p->historybuffer[0]
sub r10, r14, #HISTORY_SIZE*4 @ r10 := p->buf - HISTORY_SIZE
cmp r10, r11
bne endofloop
@ The history buffer is full, we need to do a memmove:
@ dest = r11 (p->historybuffer)
@ src = r14 (p->buf)
@ n = 200
ldmia r14!, {r0-r9} @ 40 bytes
stmia r11!, {r0-r9}
ldmia r14!, {r0-r9} @ 40 bytes
stmia r11!, {r0-r9}
ldmia r14!, {r0-r9} @ 40 bytes
stmia r11!, {r0-r9}
ldmia r14!, {r0-r9} @ 40 bytes
stmia r11!, {r0-r9}
ldmia r14!, {r0-r9} @ 40 bytes
stmia r11!, {r0-r9}
add r14, r12, #historybuffer @ p->buf = &p->historybuffer[0]
endofloop:
@ Check loop count
ldr r0, [sp, #8]
subs r0, r0, #1
strne r0, [sp, #8]
bne loop
done:
str r14, [r12] @ Save value of p->buf
add sp, sp, #12 @ Don't bother restoring r1-r3
ldmia sp!, {r4-r11, pc}
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