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ffmpeg-4.2.2/libavcodec/arm/fft_vfp.S 18.7 KB
aac5773f   hucm   功能基本完成,接口待打磨
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  /*
   * 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"
  
  @ The fftx_internal_vfp versions of the functions obey a modified AAPCS:
  @ VFP is in RunFast mode, vector length 4, stride 1 thoroughout, and
  @ all single-precision VFP registers may be corrupted on exit. The a2
  @ register may not be clobbered in these functions, as it holds the
  @ stored original FPSCR.
  
  function ff_fft_calc_vfp, export=1
          ldr     ip, [a1, #0]    @ nbits
          mov     a1, a2
          movrel  a2, (fft_tab_vfp - 8)
          ldr     pc, [a2, ip, lsl #2]
  endfunc
  const   fft_tab_vfp, relocate=1
          .word   fft4_vfp
          .word   fft8_vfp
          .word   X(ff_fft16_vfp)     @ this one alone is exported
          .word   fft32_vfp
          .word   fft64_vfp
          .word   fft128_vfp
          .word   fft256_vfp
          .word   fft512_vfp
          .word   fft1024_vfp
          .word   fft2048_vfp
          .word   fft4096_vfp
          .word   fft8192_vfp
          .word   fft16384_vfp
          .word   fft32768_vfp
          .word   fft65536_vfp
  endconst
  
  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 .Lfft8_internal_vfp
          macro_fft8_head
          macro_fft8_tail
          bx      lr
  endfunc
  
  function fft8_vfp
          ldr     a3, =0x03030000     @ RunFast mode, vector length 4, stride 1
          fmrx    a2, FPSCR
          fmxr    FPSCR, a3
          vpush   {s16-s31}
          mov     ip, lr
          bl      .Lfft8_internal_vfp
          vpop    {s16-s31}
          fmxr    FPSCR, a2
          bx      ip
  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 .Lfft16_internal_vfp
          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]
  
          bx      lr
  endfunc
  
  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}
          mov     ip, lr
          bl      .Lfft16_internal_vfp
          vpop    {s16-s31}
          fmxr    FPSCR, a2
          bx      ip
  endfunc
  
  .macro pass n, z0, z1, z2, z3
          add     v6, v5, #4*2*\n
          @ TRANSFORM_ZERO(z[0],z[o1],z[o2],z[o3])
              @ TRANSFORM(z[1],z[o1+1],z[o2+1],z[o3+1],wre[1],wim[-1])
                  @ TRANSFORM(z[0],z[o1],z[o2],z[o3],wre[0],wim[0])
                      @ TRANSFORM(z[1],z[o1+1],z[o2+1],z[o3+1],wre[1],wim[-1])
              vldr    d8, [\z2, #8*(o2+1)]        @ s16,s17
              vldmdb  v6!, {s2}
              vldr    d9, [\z3, #8*(o3+1)]        @ s18,s19
              vldmia  v5!, {s0,s1}                @ s0 is unused
          vldr    s7, [\z2, #8*o2]            @ t1
              vmul.f  s20, s16, s2                @ vector * scalar
          vldr    s0, [\z3, #8*o3]            @ t5
          vldr    s6, [\z2, #8*o2+4]          @ t2
          vldr    s3, [\z3, #8*o3+4]          @ t6
              vmul.f  s16, s16, s1                @ vector * scalar
          ldr     a4, =\n-1
  1:      add     \z0, \z0, #8*2
   .if \n*4*2 >= 512
          add     \z1, \z1, #8*2
   .endif
   .if \n*4*2 >= 256
          add     \z2, \z2, #8*2
   .endif
   .if \n*4*2 >= 512
          add     \z3, \z3, #8*2
   .endif
          @ up to 2 stalls (VFP vector issuing / waiting for s0)
          @ depending upon whether this is the first iteration and
          @ how many add instructions are inserted above
          vadd.f  s4, s0, s7                  @ t5
          vadd.f  s5, s6, s3                  @ t6
          vsub.f  s6, s6, s3                  @ t4
          vsub.f  s7, s0, s7                  @ t3
          vldr    d6, [\z0, #8*0-8*2]         @ s12,s13
              vadd.f  s0, s16, s21                @ t1
          vldr    d7, [\z1, #8*o1-8*2]        @ s14,s15
              vsub.f  s1, s18, s23                @ t5
          vadd.f  s8, s4, s12                 @ vector + vector
          @ stall (VFP vector issuing)
          @ stall (VFP vector issuing)
          @ stall (VFP vector issuing)
          vsub.f  s4, s12, s4
          vsub.f  s5, s13, s5
          vsub.f  s6, s14, s6
          vsub.f  s7, s15, s7
              vsub.f  s2, s17, s20                @ t2
              vadd.f  s3, s19, s22                @ t6
          vstr    d4, [\z0, #8*0-8*2]         @ s8,s9
          vstr    d5, [\z1, #8*o1-8*2]        @ s10,s11
          @ stall (waiting for s5)
          vstr    d2, [\z2, #8*o2-8*2]        @ s4,s5
              vadd.f  s4, s1, s0                  @ t5
          vstr    d3, [\z3, #8*o3-8*2]        @ s6,s7
              vsub.f  s7, s1, s0                  @ t3
              vadd.f  s5, s2, s3                  @ t6
              vsub.f  s6, s2, s3                  @ t4
              vldr    d6, [\z0, #8*1-8*2]         @ s12,s13
              vldr    d7, [\z1, #8*(o1+1)-8*2]    @ s14,s15
                  vldr    d4, [\z2, #8*o2]            @ s8,s9
                  vldmdb  v6!, {s2,s3}
                  vldr    d5, [\z3, #8*o3]            @ s10,s11
              vadd.f  s20, s4, s12                @ vector + vector
                  vldmia  v5!, {s0,s1}
                      vldr    d8, [\z2, #8*(o2+1)]        @ s16,s17
              @ stall (VFP vector issuing)
              vsub.f  s4, s12, s4
              vsub.f  s5, s13, s5
              vsub.f  s6, s14, s6
              vsub.f  s7, s15, s7
                  vmul.f  s12, s8, s3                 @ vector * scalar
              vstr    d10, [\z0, #8*1-8*2]        @ s20,s21
                      vldr    d9, [\z3, #8*(o3+1)]        @ s18,s19
              vstr    d11, [\z1, #8*(o1+1)-8*2]   @ s22,s23
                  vmul.f  s8, s8, s0                  @ vector * scalar
              vstr    d2, [\z2, #8*(o2+1)-8*2]    @ s4,s5
              @ stall (waiting for s7)
              vstr    d3, [\z3, #8*(o3+1)-8*2]    @ s6,s7
                      vmul.f  s20, s16, s2                @ vector * scalar
                  @ stall (VFP vector issuing)
                  @ stall (VFP vector issuing)
                  @ stall (VFP vector issuing)
                  vadd.f  s7, s8, s13                 @ t1
                  vsub.f  s6, s9, s12                 @ t2
                  vsub.f  s0, s10, s15                @ t5
                  vadd.f  s3, s11, s14                @ t6
                      vmul.f  s16, s16, s1                @ vector * scalar
          subs    a4, a4, #1
          bne     1b
          @ What remains is identical to the first two indentations of
          @ the above, but without the increment of z
          vadd.f  s4, s0, s7                  @ t5
          vadd.f  s5, s6, s3                  @ t6
          vsub.f  s6, s6, s3                  @ t4
          vsub.f  s7, s0, s7                  @ t3
          vldr    d6, [\z0, #8*0]             @ s12,s13
              vadd.f  s0, s16, s21                @ t1
          vldr    d7, [\z1, #8*o1]            @ s14,s15
              vsub.f  s1, s18, s23                @ t5
          vadd.f  s8, s4, s12                 @ vector + vector
          vsub.f  s4, s12, s4
          vsub.f  s5, s13, s5
          vsub.f  s6, s14, s6
          vsub.f  s7, s15, s7
              vsub.f  s2, s17, s20                @ t2
              vadd.f  s3, s19, s22                @ t6
          vstr    d4, [\z0, #8*0]             @ s8,s9
          vstr    d5, [\z1, #8*o1]            @ s10,s11
          vstr    d2, [\z2, #8*o2]            @ s4,s5
              vadd.f  s4, s1, s0                  @ t5
          vstr    d3, [\z3, #8*o3]            @ s6,s7
              vsub.f  s7, s1, s0                  @ t3
              vadd.f  s5, s2, s3                  @ t6
              vsub.f  s6, s2, s3                  @ t4
              vldr    d6, [\z0, #8*1]             @ s12,s13
              vldr    d7, [\z1, #8*(o1+1)]        @ s14,s15
              vadd.f  s20, s4, s12                @ vector + vector
              vsub.f  s4, s12, s4
              vsub.f  s5, s13, s5
              vsub.f  s6, s14, s6
              vsub.f  s7, s15, s7
              vstr    d10, [\z0, #8*1]            @ s20,s21
              vstr    d11, [\z1, #8*(o1+1)]       @ s22,s23
              vstr    d2, [\z2, #8*(o2+1)]        @ s4,s5
              vstr    d3, [\z3, #8*(o3+1)]        @ s6,s7
  .endm
  
  .macro  def_fft n, n2, n4
  function .Lfft\n\()_internal_vfp
   .if \n >= 512
          push    {v1-v6,lr}
   .elseif \n >= 256
          push    {v1-v2,v5-v6,lr}
   .else
          push    {v1,v5-v6,lr}
   .endif
          mov     v1, a1
          bl      .Lfft\n2\()_internal_vfp
          add     a1, v1, #8*(\n/4)*2
          bl      .Lfft\n4\()_internal_vfp
          movrelx v5, X(ff_cos_\n), a1
          add     a1, v1, #8*(\n/4)*3
          bl      .Lfft\n4\()_internal_vfp
   .if \n >= 512
    .set o1, 0*(\n/4/2)
    .set o2, 0*(\n/4/2)
    .set o3, 0*(\n/4/2)
          add     v2, v1, #8*2*(\n/4/2)
          add     v3, v1, #8*4*(\n/4/2)
          add     v4, v1, #8*6*(\n/4/2)
          pass    (\n/4/2), v1, v2, v3, v4
          pop     {v1-v6,pc}
   .elseif \n >= 256
    .set o1, 2*(\n/4/2)
    .set o2, 0*(\n/4/2)
    .set o3, 2*(\n/4/2)
          add     v2, v1, #8*4*(\n/4/2)
          pass    (\n/4/2), v1, v1, v2, v2
          pop     {v1-v2,v5-v6,pc}
   .else
    .set o1, 2*(\n/4/2)
    .set o2, 4*(\n/4/2)
    .set o3, 6*(\n/4/2)
          pass    (\n/4/2), v1, v1, v1, v1
          pop     {v1,v5-v6,pc}
   .endif
  endfunc
  
  function fft\n\()_vfp
          ldr     a3, =0x03030000 /* RunFast mode, vector length 4, stride 1 */
          fmrx    a2, FPSCR
          fmxr    FPSCR, a3
          vpush   {s16-s31}
          mov     ip, lr
          bl      .Lfft\n\()_internal_vfp
          vpop    {s16-s31}
          fmxr    FPSCR, a2
          bx      ip
  endfunc
  
  .ltorg
  .endm
  
          def_fft    32,    16,     8
          def_fft    64,    32,    16
          def_fft   128,    64,    32
          def_fft   256,   128,    64
          def_fft   512,   256,   128
          def_fft  1024,   512,   256
          def_fft  2048,  1024,   512
          def_fft  4096,  2048,  1024
          def_fft  8192,  4096,  2048
          def_fft 16384,  8192,  4096
          def_fft 32768, 16384,  8192
          def_fft 65536, 32768, 16384