rockbox/apps/plugins/mpegplayer/idct_armv6.S
Jens Arnold 0a2197b846 Further ARMv6 imdct optimisation, ~5.5% speedup.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@21884 a1c6a512-1295-4272-9138-f99709370657
2009-07-15 20:36:31 +00:00

295 lines
9.6 KiB
ArmAsm

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2009 by Jens Arnold
*
* 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.
*
****************************************************************************/
.global mpeg2_idct_copy
.type mpeg2_idct_copy, %function
.global mpeg2_idct_add
.type mpeg2_idct_add, %function
/* Custom calling convention:
* r0 contains block pointer and is non-volatile
* all non-volatile c context saved and restored on its behalf
*/
.idct:
str lr, [sp, #-4]! @ lr is used
add r1, r0, #128 @ secondary, transposed temp buffer
mov r14, #8 @ loop counter
.row_loop:
ldmia r0!, {r2, r3, r10, r11} @ fetch f0, f2, f4, f6, f1, f3, f5, f7
ldrd r4, L_W1357 @ load W1, W3, W5, W7
smuad r6, r4, r10 @ b0 = W1 * f1 + W3 * f3
smlad r6, r5, r11, r6 @ + W5 * f5 + W7 * f7
smultt r7, r5, r10 @ b1 = -W7 * f3
smlabb r7, r4, r11, r7 @ + -W1 * f5
smlabt r7, r5, r11, r7 @ + -W5 * f7
rsb r7, r7, #0
smlatb r7, r4, r10, r7 @ + W3 * f1
smulbt r8, r4, r10 @ b2 = -W1 * f3
rsb r8, r8, #0
smlabb r8, r5, r10, r8 @ + W5 * f1
smlatb r8, r5, r11, r8 @ + W7 * f5
smlatt r8, r4, r11, r8 @ + W3 * f7
smusdx r9, r10, r5 @ b3 = f1 * W7 - f3 * W5
smlsdx r9, r11, r4, r9 @ + f5 * W3 - f1 * W1
ldrd r4, L_W0246 @ load W0, W2, W4, W6
add r2, r2, #1 @ f0 += 1
smulbb r10, r4, r2 @ a0' = W0 * f0
smlabb r10, r5, r3, r10 @ + W4 * f4
smultt r12, r4, r2 @ a3' = W2 * f2
smlatt r12, r5, r3, r12 @ + W6 * f6
add r10, r10, r12 @ a0 = a0' + a3'
sub r12, r10, r12, lsl #1 @ a3 = a0 - 2 * a3'
smulbb r11, r5, r3 @ a1' = -W4 * f4
rsb r11, r11, #0
smlabb r11, r4, r2, r11 @ + W0 * f0
smultt r3, r4, r3 @ a2' = -W2 * f6
rsb r3, r3, #0
smlatt r3, r5, r2, r3 @ + W6 * f2
add r11, r11, r3 @ a1 = a1' + a2'
sub r3, r11, r3, lsl #1 @ a2 = a1 - 2 * a2'
@ Special store order for making the column pass calculate columns in
@ the order 0-2-1-3-4-6-5-7, allowing for uxtab16 use in later stages.
sub r2, r10, r6 @ block[7] = (a0 - b0)
mov r2, r2, asr #12 @ >> 12
strh r2, [r1, #7*16]
sub r2, r11, r7 @ block[6] = (a1 - b1)
mov r2, r2, asr #12 @ >> 12
strh r2, [r1, #5*16]
sub r2, r3, r8 @ block[5] = (a2 - b2)
mov r2, r2, asr #12 @ >> 12
strh r2, [r1, #6*16]
sub r2, r12, r9 @ block[4] = (a3 - b3)
mov r2, r2, asr #12 @ >> 12
strh r2, [r1, #4*16]
add r2, r12, r9 @ block[3] = (a3 + b3)
mov r2, r2, asr #12 @ >> 12
strh r2, [r1, #3*16]
add r2, r3, r8 @ block[2] = (a2 + b2)
mov r2, r2, asr #12 @ >> 12
strh r2, [r1, #1*16]
add r2, r11, r7 @ block[1] = (a1 + b1)
mov r2, r2, asr #12 @ >> 12
strh r2, [r1, #2*16]
add r2, r10, r6 @ block[0] = (a0 + b0)
mov r2, r2, asr #12 @ >> 12
strh r2, [r1], #2 @ advance to next temp column
subs r14, r14, #1
bne .row_loop
b .col_start
@placed here because of ldrd's offset limit
L_W1357:
.short 2841
.short 2408
.short 1609
.short 565
L_W0246:
.short 2048
.short 2676
.short 2048
.short 1108
.col_start:
@ r0 now points to the temp buffer, where we need it.
sub r1, r1, #128+16 @ point r1 back to the input block
mov r14, #8 @ loop counter
.col_loop:
ldmia r0!, {r2, r3, r10, r11} @ fetch f0, f2, f4, f6, f1, f3, f5, f7
ldrd r4, L_W1357 @ load W1, W3, W5, W7
smuad r6, r4, r10 @ b0 = W1 * f1 + W3 * f3
smlad r6, r5, r11, r6 @ + W5 * f5 + W7 * f7
smultt r7, r5, r10 @ b1 = -W7 * f3
smlabb r7, r4, r11, r7 @ + -W1 * f5
smlabt r7, r5, r11, r7 @ + -W5 * f7
rsb r7, r7, #0
smlatb r7, r4, r10, r7 @ + W3 * f1
smulbt r8, r4, r10 @ b2 = -W1 * f3
rsb r8, r8, #0
smlabb r8, r5, r10, r8 @ + W5 * f1
smlatb r8, r5, r11, r8 @ + W7 * f5
smlatt r8, r4, r11, r8 @ + W3 * f7
smusdx r9, r10, r5 @ b3 = f1 * W7 - f3 * W5
smlsdx r9, r11, r4, r9 @ + f5 * W3 - f1 * W1
ldrd r4, L_W0246 @ load W0, W2, W4, W6
add r2, r2, #32 @ DC offset: 0.5
smulbb r10, r4, r2 @ a0' = W0 * f0
smlabb r10, r5, r3, r10 @ + W4 * f4
smultt r12, r4, r2 @ a3' = W2 * f2
smlatt r12, r5, r3, r12 @ + W6 * f6
add r10, r10, r12 @ a0 = a0' + a3'
sub r12, r10, r12, lsl #1 @ a3 = a0 - 2 * a3'
smulbb r11, r5, r3 @ a1' = -W4 * f4
rsb r11, r11, #0
smlabb r11, r4, r2, r11 @ + W0 * f0
smultt r3, r4, r3 @ a2' = -W2 * f6
rsb r3, r3, #0
smlatt r3, r5, r2, r3 @ + W6 * f2
add r11, r11, r3 @ a1 = a1' + a2'
sub r3, r11, r3, lsl #1 @ a2 = a1 - 2 * a2'
sub r2, r10, r6 @ block[7] = (a0 - b0)
mov r2, r2, asr #17 @ >> 17
strh r2, [r1, #7*16]
sub r2, r11, r7 @ block[6] = (a1 - b1)
mov r2, r2, asr #17 @ >> 17
strh r2, [r1, #6*16]
sub r2, r3, r8 @ block[5] = (a2 - b2)
mov r2, r2, asr #17 @ >> 17
strh r2, [r1, #5*16]
sub r2, r12, r9 @ block[4] = (a3 - b3)
mov r2, r2, asr #17 @ >> 17
strh r2, [r1, #4*16]
add r2, r12, r9 @ block[3] = (a3 + b3)
mov r2, r2, asr #17 @ >> 17
strh r2, [r1, #3*16]
add r2, r3, r8 @ block[2] = (a2 + b2)
mov r2, r2, asr #17 @ >> 17
strh r2, [r1, #2*16]
add r2, r11, r7 @ block[1] = (a1 + b1)
mov r2, r2, asr #17 @ >> 17
strh r2, [r1, #1*16]
add r2, r10, r6 @ block[0] = (a0 + b0)
mov r2, r2, asr #17 @ >> 17
strh r2, [r1], #2 @ advance to next column
subs r14, r14, #1
bne .col_loop
sub r0, r0, #256 @ point r0 back to the input block
ldr pc, [sp], #4
mpeg2_idct_copy:
stmfd sp!, {r1-r2, r4-r11, lr}
bl .idct
ldmfd sp!, {r1-r2}
add r3, r0, #128
mov r8, #0
mov r9, #0
mov r10, #0
mov r11, #0
1: @ idct data is in order 0-2-1-3-4-6-5-7,
ldmia r0, {r4-r7} @ see above
stmia r0!, {r8-r11}
usat16 r4, #8, r4
usat16 r5, #8, r5
orr r4, r4, r5, lsl #8
usat16 r6, #8, r6
usat16 r7, #8, r7
orr r5, r6, r7, lsl #8
strd r4, [r1] @ r4, r5
add r1, r1, r2
cmp r0, r3
blo 1b
ldmfd sp!, {r4-r11, pc}
mpeg2_idct_add:
cmp r0, #129
mov r0, r1
ldreqsh r1, [r0, #0]
bne 1f
and r1, r1, #0x70
cmp r1, #0x40
bne 3f
1:
stmfd sp!, {r2-r11, lr}
bl .idct
ldmfd sp!, {r1-r2}
add r3, r0, #128
mov r10, #0
mov r11, #0
mov r12, #0
mov lr, #0
ldrd r8, [r1] @ r8, r9
2: @ idct data is in order 0-2-1-3-4-6-5-7,
ldmia r0, {r4-r7} @ see above
stmia r0!, {r10-r12, lr}
uxtab16 r4, r4, r8
uxtab16 r5, r5, r8, ror #8
usat16 r4, #8, r4
usat16 r5, #8, r5
orr r4, r4, r5, lsl #8
uxtab16 r6, r6, r9
uxtab16 r7, r7, r9, ror #8
usat16 r6, #8, r6
usat16 r7, #8, r7
orr r5, r6, r7, lsl #8
strd r4, [r1] @ r4, r5
add r1, r1, r2
cmp r0, r3
ldrlod r8, [r1] @ r8, r9
blo 2b
ldmfd sp!, {r4-r11, pc}
3:
stmfd sp!, {r4, lr}
ldrsh r4, [r0, #0] @ r4 = block[0]
mov r12, #0
strh r12, [r0, #0] @ block[0] = 0
strh r12, [r0, #126] @ block[63] = 0
add r4, r4, #64
mov r4, r4, asr #7 @ r4 = DC
mov r4, r4, lsl #16 @ spread to 2 halfwords
orr r4, r4, r4, lsr #16
ldrd r0, [r2] @ r0, r1
add r12, r2, r3, asl #3
4:
uxtab16 lr, r4, r0, ror #8
uxtab16 r0, r4, r0
usat16 lr, #8, lr
usat16 r0, #8, r0
orr r0, r0, lr, lsl #8
uxtab16 lr, r4, r1, ror #8
uxtab16 r1, r4, r1
usat16 lr, #8, lr
usat16 r1, #8, r1
orr r1, r1, lr, lsl #8
strd r0, [r2] @ r0, r1
add r2, r2, r3
cmp r2, r12
ldrlod r0, [r2] @ r0, r1
blo 4b
ldmfd sp!, {r4, pc}