/*
* Copyright (c) 2016 Clément Bœsch
* Copyright (c) 2016 Matthieu Bouron
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/arm/asm.S"
function ff_yuv2planeX_8_neon, export=1
push {r4-r12, lr}
vpush {q4-q7}
ldr r4, [sp, #104] @ dstW
ldr r5, [sp, #108] @ dither
ldr r6, [sp, #112] @ offset
vld1.8 {d0}, [r5] @ load 8x8-bit dither values
cmp r6, #0 @ check offsetting which can be 0 or 3 only
beq 1f
vext.u8 d0, d0, d0, #3 @ honor offseting which can be 3 only
1: vmovl.u8 q0, d0 @ extend dither to 16-bit
vshll.u16 q1, d0, #12 @ extend dither to 32-bit with left shift by 12 (part 1)
vshll.u16 q2, d1, #12 @ extend dither to 32-bit with left shift by 12 (part 2)
mov r7, #0 @ i = 0
2: vmov.u8 q3, q1 @ initialize accumulator with dithering values (part 1)
vmov.u8 q4, q2 @ initialize accumulator with dithering values (part 2)
mov r8, r1 @ tmpFilterSize = filterSize
mov r9, r2 @ srcp
mov r10, r0 @ filterp
3: ldr r11, [r9], #4 @ get pointer @ src[j]
ldr r12, [r9], #4 @ get pointer @ src[j+1]
add r11, r11, r7, lsl #1 @ &src[j][i]
add r12, r12, r7, lsl #1 @ &src[j+1][i]
vld1.16 {q5}, [r11] @ read 8x16-bit @ src[j ][i + {0..7}]: A,B,C,D,E,F,G,H
vld1.16 {q6}, [r12] @ read 8x16-bit @ src[j+1][i + {0..7}]: I,J,K,L,M,N,O,P
ldr r11, [r10], #4 @ read 2x16-bit coeffs (X, Y) at (filter[j], filter[j+1])
vmov.16 q7, q5 @ copy 8x16-bit @ src[j ][i + {0..7}] for following inplace zip instruction
vmov.16 q8, q6 @ copy 8x16-bit @ src[j+1][i + {0..7}] for following inplace zip instruction
vzip.16 q7, q8 @ A,I,B,J,C,K,D,L,E,M,F,N,G,O,H,P
vdup.32 q15, r11 @ X,Y,X,Y,X,Y,X,Y
vmull.s16 q9, d14, d30 @ A*X,I*Y,B*X,J*Y
vmull.s16 q10, d15, d31 @ C*X,K*Y,D*X,L*Y
vmull.s16 q11, d16, d30 @ E*X,M*Y,F*X,N*Y
vmull.s16 q12, d17, d31 @ G*X,O*Y,H*X,P*Y
vpadd.s32 d10, d18, d19 @ A*X+I*Y,B*X+J*Y
vpadd.s32 d11, d20, d21 @ C*X+K*Y,D*X+L*Y
vpadd.s32 d12, d22, d23 @ E*X+M*Y,F*X+N*Y
vpadd.s32 d13, d24, d25 @ G*X+O*Y,H*X+P*Y
vadd.s32 q3, q5 @ update val accumulator (part 1)
vadd.s32 q4, q6 @ update val accumulator (part 2)
subs r8, #2 @ tmpFilterSize -= 2
bgt 3b @ loop until filterSize is consumed
vshr.s32 q3, q3, #19 @ val>>19 (part 1)
vshr.s32 q4, q4, #19 @ val>>19 (part 2)
vqmovun.s32 d6, q3 @ clip16(val>>19) (part 1)
vqmovun.s32 d7, q4 @ clip16(val>>19) (part 2)
vqmovn.u16 d6, q3 @ merge part 1 and part 2
vst1.8 {d6}, [r3]! @ write destination
add r7, #8 @ i += 8
subs r4, r4, #8 @ dstW -= 8
bgt 2b @ loop until width is consumed
vpop {q4-q7}
pop {r4-r12, lr}
mov pc, lr
endfunc