vpx/vp8/common/arm/neon/iwalsh_neon.asm
Scott LaVarnway 4a91541c94 Modified the inverse walsh to output directly
to the dqcoeff or qcoeff buffer.  The encoder would
populate the dc coeffs of the y blocks as a separate
stage (recon_dcblock) and the decoder would use a special
version of the idct.  This change eliminates the extra copy
and reduces the code footprint.

[Tero] Added needed changes to armv6 and NEON assembly.

Change-Id: I83202ffdbaf83f6e5dd69f4ba2519fcf0b13b3ba
2011-11-25 09:24:04 +02:00

88 lines
2.2 KiB
NASM

;
; Copyright (c) 2010 The WebM project authors. All Rights Reserved.
;
; Use of this source code is governed by a BSD-style license
; that can be found in the LICENSE file in the root of the source
; tree. An additional intellectual property rights grant can be found
; in the file PATENTS. All contributing project authors may
; be found in the AUTHORS file in the root of the source tree.
;
EXPORT |vp8_short_inv_walsh4x4_neon|
ARM
REQUIRE8
PRESERVE8
AREA |.text|, CODE, READONLY ; name this block of code
;short vp8_short_inv_walsh4x4_neon(short *input, short *mb_dqcoeff)
|vp8_short_inv_walsh4x4_neon| PROC
; read in all four lines of values: d0->d3
vld1.i16 {q0-q1}, [r0@128]
; first for loop
vadd.s16 d4, d0, d3 ;a = [0] + [12]
vadd.s16 d6, d1, d2 ;b = [4] + [8]
vsub.s16 d5, d0, d3 ;d = [0] - [12]
vsub.s16 d7, d1, d2 ;c = [4] - [8]
vadd.s16 q0, q2, q3 ; a+b d+c
vsub.s16 q1, q2, q3 ; a-b d-c
vtrn.32 d0, d2 ;d0: 0 1 8 9
;d2: 2 3 10 11
vtrn.32 d1, d3 ;d1: 4 5 12 13
;d3: 6 7 14 15
vtrn.16 d0, d1 ;d0: 0 4 8 12
;d1: 1 5 9 13
vtrn.16 d2, d3 ;d2: 2 6 10 14
;d3: 3 7 11 15
; second for loop
vadd.s16 d4, d0, d3 ;a = [0] + [3]
vadd.s16 d6, d1, d2 ;b = [1] + [2]
vsub.s16 d5, d0, d3 ;d = [0] - [3]
vsub.s16 d7, d1, d2 ;c = [1] - [2]
vmov.i16 q8, #3
vadd.s16 q0, q2, q3 ; a+b d+c
vsub.s16 q1, q2, q3 ; a-b d-c
vadd.i16 q0, q0, q8 ;e/f += 3
vadd.i16 q1, q1, q8 ;g/h += 3
vshr.s16 q0, q0, #3 ;e/f >> 3
vshr.s16 q1, q1, #3 ;g/h >> 3
mov r2, #64
add r3, r1, #32
vst1.i16 d0[0], [r1],r2
vst1.i16 d1[0], [r3],r2
vst1.i16 d2[0], [r1],r2
vst1.i16 d3[0], [r3],r2
vst1.i16 d0[1], [r1],r2
vst1.i16 d1[1], [r3],r2
vst1.i16 d2[1], [r1],r2
vst1.i16 d3[1], [r3],r2
vst1.i16 d0[2], [r1],r2
vst1.i16 d1[2], [r3],r2
vst1.i16 d2[2], [r1],r2
vst1.i16 d3[2], [r3],r2
vst1.i16 d0[3], [r1],r2
vst1.i16 d1[3], [r3],r2
vst1.i16 d2[3], [r1]
vst1.i16 d3[3], [r3]
bx lr
ENDP ; |vp8_short_inv_walsh4x4_neon|
END