/*
* Copyright (c) 2013 RISC OS Open Ltd
* Author: Ben Avison <bavison@riscosopen.org>
*
* 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"
@ TODO: * FFTs wider than 16
@ * dispatch code
function fft4_vfp
vldr d0, [a1, #0*2*4] @ s0,s1 = z[0]
vldr d4, [a1, #1*2*4] @ s8,s9 = z[1]
vldr d1, [a1, #2*2*4] @ s2,s3 = z[2]
vldr d5, [a1, #3*2*4] @ s10,s11 = z[3]
@ stall
vadd.f s12, s0, s8 @ i0
vadd.f s13, s1, s9 @ i1
vadd.f s14, s2, s10 @ i2
vadd.f s15, s3, s11 @ i3
vsub.f s8, s0, s8 @ i4
vsub.f s9, s1, s9 @ i5
vsub.f s10, s2, s10 @ i6
vsub.f s11, s3, s11 @ i7
@ stall
@ stall
vadd.f s0, s12, s14 @ z[0].re
vsub.f s4, s12, s14 @ z[2].re
vadd.f s1, s13, s15 @ z[0].im
vsub.f s5, s13, s15 @ z[2].im
vadd.f s7, s9, s10 @ z[3].im
vsub.f s3, s9, s10 @ z[1].im
vadd.f s2, s8, s11 @ z[1].re
vsub.f s6, s8, s11 @ z[3].re
@ stall
@ stall
vstr d0, [a1, #0*2*4]
vstr d2, [a1, #2*2*4]
@ stall
@ stall
vstr d1, [a1, #1*2*4]
vstr d3, [a1, #3*2*4]
bx lr
endfunc
.macro macro_fft8_head
@ FFT4
vldr d4, [a1, #0 * 2*4]
vldr d6, [a1, #1 * 2*4]
vldr d5, [a1, #2 * 2*4]
vldr d7, [a1, #3 * 2*4]
@ BF
vldr d12, [a1, #4 * 2*4]
vadd.f s16, s8, s12 @ vector op
vldr d14, [a1, #5 * 2*4]
vldr d13, [a1, #6 * 2*4]
vldr d15, [a1, #7 * 2*4]
vsub.f s20, s8, s12 @ vector op
vadd.f s0, s16, s18
vsub.f s2, s16, s18
vadd.f s1, s17, s19
vsub.f s3, s17, s19
vadd.f s7, s21, s22
vsub.f s5, s21, s22
vadd.f s4, s20, s23
vsub.f s6, s20, s23
vsub.f s20, s24, s28 @ vector op
vstr d0, [a1, #0 * 2*4] @ transfer s0-s7 to s24-s31 via memory
vstr d1, [a1, #1 * 2*4]
vldr s0, cos1pi4
vadd.f s16, s24, s28 @ vector op
vstr d2, [a1, #2 * 2*4]
vstr d3, [a1, #3 * 2*4]
vldr d12, [a1, #0 * 2*4]
@ TRANSFORM
vmul.f s20, s20, s0 @ vector x scalar op
vldr d13, [a1, #1 * 2*4]
vldr d14, [a1, #2 * 2*4]
vldr d15, [a1, #3 * 2*4]
@ BUTTERFLIES
vadd.f s0, s18, s16
vadd.f s1, s17, s19
vsub.f s2, s17, s19
vsub.f s3, s18, s16
vadd.f s4, s21, s20
vsub.f s5, s21, s20
vadd.f s6, s22, s23
vsub.f s7, s22, s23
vadd.f s8, s0, s24 @ vector op
vstr d0, [a1, #0 * 2*4] @ transfer s0-s3 to s12-s15 via memory
vstr d1, [a1, #1 * 2*4]
vldr d6, [a1, #0 * 2*4]
vldr d7, [a1, #1 * 2*4]
vadd.f s1, s5, s6
vadd.f s0, s7, s4
vsub.f s2, s5, s6
vsub.f s3, s7, s4
vsub.f s12, s24, s12 @ vector op
vsub.f s5, s29, s1
vsub.f s4, s28, s0
vsub.f s6, s30, s2
vsub.f s7, s31, s3
vadd.f s16, s0, s28 @ vector op
vstr d6, [a1, #4 * 2*4]
vstr d7, [a1, #6 * 2*4]
vstr d4, [a1, #0 * 2*4]
vstr d5, [a1, #2 * 2*4]
vstr d2, [a1, #5 * 2*4]
vstr d3, [a1, #7 * 2*4]
.endm
.macro macro_fft8_tail
vstr d8, [a1, #1 * 2*4]
vstr d9, [a1, #3 * 2*4]
.endm
function fft8_vfp
ldr a3, =0x03030000 @ RunFast mode, vector length 4, stride 1
fmrx a2, FPSCR
fmxr FPSCR, a3
vpush {s16-s31}
macro_fft8_head
macro_fft8_tail
vpop {s16-s31}
fmxr FPSCR, a2
bx lr
endfunc
.align 3
cos1pi4: @ cos(1*pi/4) = sqrt(2)
.float 0.707106769084930419921875
cos1pi8: @ cos(1*pi/8) = sqrt(2+sqrt(2))/2
.float 0.92387950420379638671875
cos3pi8: @ cos(2*pi/8) = sqrt(2-sqrt(2))/2
.float 0.3826834261417388916015625
function ff_fft16_vfp, export=1
ldr a3, =0x03030000 @ RunFast mode, vector length 4, stride 1
fmrx a2, FPSCR
fmxr FPSCR, a3
vpush {s16-s31}
macro_fft8_head
@ FFT4(z+8)
vldr d10, [a1, #8 * 2*4]
vldr d12, [a1, #9 * 2*4]
vldr d11, [a1, #10 * 2*4]
vldr d13, [a1, #11 * 2*4]
macro_fft8_tail
vadd.f s16, s20, s24 @ vector op
@ FFT4(z+12)
vldr d4, [a1, #12 * 2*4]
vldr d6, [a1, #13 * 2*4]
vldr d5, [a1, #14 * 2*4]
vsub.f s20, s20, s24 @ vector op
vldr d7, [a1, #15 * 2*4]
vadd.f s0, s16, s18
vsub.f s4, s16, s18
vadd.f s1, s17, s19
vsub.f s5, s17, s19
vadd.f s7, s21, s22
vsub.f s3, s21, s22
vadd.f s2, s20, s23
vsub.f s6, s20, s23
vadd.f s16, s8, s12 @ vector op
vstr d0, [a1, #8 * 2*4]
vstr d2, [a1, #10 * 2*4]
vstr d1, [a1, #9 * 2*4]
vsub.f s20, s8, s12
vstr d3, [a1, #11 * 2*4]
@ TRANSFORM(z[2],z[6],z[10],z[14],cos1pi4,cos1pi4)
vldr d12, [a1, #10 * 2*4]
vadd.f s0, s16, s18
vadd.f s1, s17, s19
vsub.f s6, s16, s18
vsub.f s7, s17, s19
vsub.f s3, s21, s22
vadd.f s2, s20, s23
vadd.f s5, s21, s22
vsub.f s4, s20, s23
vstr d0, [a1, #12 * 2*4]
vmov s0, s6
@ TRANSFORM(z[1],z[5],z[9],z[13],cos1pi8,cos3pi8)
vldr d6, [a1, #9 * 2*4]
vstr d1, [a1, #13 * 2*4]
vldr d1, cos1pi4 @ s2 = cos1pi4, s3 = cos1pi8
vstr d2, [a1, #15 * 2*4]
vldr d7, [a1, #13 * 2*4]
vadd.f s4, s25, s24
vsub.f s5, s25, s24
vsub.f s6, s0, s7
vadd.f s7, s0, s7
vmul.f s20, s12, s3 @ vector op
@ TRANSFORM(z[3],z[7],z[11],z[15],cos3pi8,cos1pi8)
vldr d4, [a1, #11 * 2*4]
vldr d5, [a1, #15 * 2*4]
vldr s1, cos3pi8
vmul.f s24, s4, s2 @ vector * scalar op
vmul.f s28, s12, s1 @ vector * scalar op
vmul.f s12, s8, s1 @ vector * scalar op
vadd.f s4, s20, s29
vsub.f s5, s21, s28
vsub.f s6, s22, s31
vadd.f s7, s23, s30
vmul.f s8, s8, s3 @ vector * scalar op
vldr d8, [a1, #1 * 2*4]
vldr d9, [a1, #5 * 2*4]
vldr d10, [a1, #3 * 2*4]
vldr d11, [a1, #7 * 2*4]
vldr d14, [a1, #2 * 2*4]
vadd.f s0, s6, s4
vadd.f s1, s5, s7
vsub.f s2, s5, s7
vsub.f s3, s6, s4
vadd.f s4, s12, s9
vsub.f s5, s13, s8
vsub.f s6, s14, s11
vadd.f s7, s15, s10
vadd.f s12, s0, s16 @ vector op
vstr d0, [a1, #1 * 2*4]
vstr d1, [a1, #5 * 2*4]
vldr d4, [a1, #1 * 2*4]
vldr d5, [a1, #5 * 2*4]
vadd.f s0, s6, s4
vadd.f s1, s5, s7
vsub.f s2, s5, s7
vsub.f s3, s6, s4
vsub.f s8, s16, s8 @ vector op
vstr d6, [a1, #1 * 2*4]
vstr d7, [a1, #5 * 2*4]
vldr d15, [a1, #6 * 2*4]
vsub.f s4, s20, s0
vsub.f s5, s21, s1
vsub.f s6, s22, s2
vsub.f s7, s23, s3
vadd.f s20, s0, s20 @ vector op
vstr d4, [a1, #9 * 2*4]
@ TRANSFORM_ZERO(z[0],z[4],z[8],z[12])
vldr d6, [a1, #8 * 2*4]
vstr d5, [a1, #13 * 2*4]
vldr d7, [a1, #12 * 2*4]
vstr d2, [a1, #11 * 2*4]
vldr d8, [a1, #0 * 2*4]
vstr d3, [a1, #15 * 2*4]
vldr d9, [a1, #4 * 2*4]
vadd.f s0, s26, s24
vadd.f s1, s25, s27
vsub.f s2, s25, s27
vsub.f s3, s26, s24
vadd.f s4, s14, s12
vadd.f s5, s13, s15
vsub.f s6, s13, s15
vsub.f s7, s14, s12
vadd.f s8, s0, s28 @ vector op
vstr d0, [a1, #3 * 2*4]
vstr d1, [a1, #7 * 2*4]
vldr d6, [a1, #3 * 2*4]
vldr d7, [a1, #7 * 2*4]
vsub.f s0, s16, s4
vsub.f s1, s17, s5
vsub.f s2, s18, s6
vsub.f s3, s19, s7
vsub.f s12, s28, s12 @ vector op
vadd.f s16, s4, s16 @ vector op
vstr d10, [a1, #3 * 2*4]
vstr d11, [a1, #7 * 2*4]
vstr d4, [a1, #2 * 2*4]
vstr d5, [a1, #6 * 2*4]
vstr d0, [a1, #8 * 2*4]
vstr d1, [a1, #12 * 2*4]
vstr d6, [a1, #10 * 2*4]
vstr d7, [a1, #14 * 2*4]
vstr d8, [a1, #0 * 2*4]
vstr d9, [a1, #4 * 2*4]
vpop {s16-s31}
fmxr FPSCR, a2
bx lr
endfunc