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C++ C_SUB函数代码示例

本文整理汇总了C++中C_SUB函数的典型用法代码示例。如果您正苦于以下问题：C++ C_SUB函数的具体用法？C++ C_SUB怎么用？C++ C_SUB使用的例子？那么恭喜您, 这里精选的函数代码示例或许可以为您提供帮助。


在下文中一共展示了C_SUB函数的12个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。

示例1: kf_bfly5

static void kf_bfly5(
        kiss_fft_cpx * Fout,
        const size_t fstride,
        const kiss_fft_cfg st,
        int m
        )
{
    kiss_fft_cpx *Fout0,*Fout1,*Fout2,*Fout3,*Fout4;
    int u;
    kiss_fft_cpx scratch[13];
    kiss_fft_cpx * twiddles = st->twiddles;
    kiss_fft_cpx *tw;
    kiss_fft_cpx ya,yb;
    ya = twiddles[fstride*m];
    yb = twiddles[fstride*2*m];

    Fout0=Fout;
    Fout1=Fout0+m;
    Fout2=Fout0+2*m;
    Fout3=Fout0+3*m;
    Fout4=Fout0+4*m;

    tw=st->twiddles;
    for ( u=0; u<m; ++u ) {
        C_FIXDIV( *Fout0,5); C_FIXDIV( *Fout1,5); C_FIXDIV( *Fout2,5); C_FIXDIV( *Fout3,5); C_FIXDIV( *Fout4,5);
        scratch[0] = *Fout0;

        C_MUL(scratch[1] ,*Fout1, tw[u*fstride]);
        C_MUL(scratch[2] ,*Fout2, tw[2*u*fstride]);
        C_MUL(scratch[3] ,*Fout3, tw[3*u*fstride]);
        C_MUL(scratch[4] ,*Fout4, tw[4*u*fstride]);

        C_ADD( scratch[7],scratch[1],scratch[4]);
        C_SUB( scratch[10],scratch[1],scratch[4]);
        C_ADD( scratch[8],scratch[2],scratch[3]);
        C_SUB( scratch[9],scratch[2],scratch[3]);

        Fout0->r += scratch[7].r + scratch[8].r;
        Fout0->i += scratch[7].i + scratch[8].i;

        scratch[5].r = scratch[0].r + S_MUL(scratch[7].r,ya.r) + S_MUL(scratch[8].r,yb.r);
        scratch[5].i = scratch[0].i + S_MUL(scratch[7].i,ya.r) + S_MUL(scratch[8].i,yb.r);

        scratch[6].r =  S_MUL(scratch[10].i,ya.i) + S_MUL(scratch[9].i,yb.i);
        scratch[6].i = -S_MUL(scratch[10].r,ya.i) - S_MUL(scratch[9].r,yb.i);

        C_SUB(*Fout1,scratch[5],scratch[6]);
        C_ADD(*Fout4,scratch[5],scratch[6]);

        scratch[11].r = scratch[0].r + S_MUL(scratch[7].r,yb.r) + S_MUL(scratch[8].r,ya.r);
        scratch[11].i = scratch[0].i + S_MUL(scratch[7].i,yb.r) + S_MUL(scratch[8].i,ya.r);
        scratch[12].r = - S_MUL(scratch[10].i,yb.i) + S_MUL(scratch[9].i,ya.i);
        scratch[12].i = S_MUL(scratch[10].r,yb.i) - S_MUL(scratch[9].r,ya.i);

        C_ADD(*Fout2,scratch[11],scratch[12]);
        C_SUB(*Fout3,scratch[11],scratch[12]);

        ++Fout0;++Fout1;++Fout2;++Fout3;++Fout4;
    }
}
开发者ID:Arcko，项目名称:xbmc，代码行数:60，代码来源:kiss_fft.c

示例2: kf_bfly2

static void kf_bfly2(
                     kiss_fft_cpx * Fout,
                     int m,
                     int N
                    )
{
   kiss_fft_cpx * Fout2;
   int i;
   (void)m;
#ifdef CUSTOM_MODES
   if (m==1)
   {
      celt_assert(m==1);
      for (i=0;i<N;i++)
      {
         kiss_fft_cpx t;
         Fout2 = Fout + 1;
         t = *Fout2;
         C_SUB( *Fout2 ,  *Fout , t );
         C_ADDTO( *Fout ,  t );
         Fout += 2;
      }
   } else
#endif
   {
      opus_val16 tw;
      tw = QCONST16(0.7071067812f, 15);
      /* We know that m==4 here because the radix-2 is just after a radix-4 */
      celt_assert(m==4);
      for (i=0;i<N;i++)
      {
         kiss_fft_cpx t;
         Fout2 = Fout + 4;
         t = Fout2[0];
         C_SUB( Fout2[0] ,  Fout[0] , t );
         C_ADDTO( Fout[0] ,  t );

         t.r = S_MUL(ADD32_ovflw(Fout2[1].r, Fout2[1].i), tw);
         t.i = S_MUL(SUB32_ovflw(Fout2[1].i, Fout2[1].r), tw);
         C_SUB( Fout2[1] ,  Fout[1] , t );
         C_ADDTO( Fout[1] ,  t );

         t.r = Fout2[2].i;
         t.i = -Fout2[2].r;
         C_SUB( Fout2[2] ,  Fout[2] , t );
         C_ADDTO( Fout[2] ,  t );

         t.r = S_MUL(SUB32_ovflw(Fout2[3].i, Fout2[3].r), tw);
         t.i = S_MUL(NEG32_ovflw(ADD32_ovflw(Fout2[3].i, Fout2[3].r)), tw);
         C_SUB( Fout2[3] ,  Fout[3] , t );
         C_ADDTO( Fout[3] ,  t );
         Fout += 8;
      }
   }
}
开发者ID:Appsgeyser，项目名称:Custom-messenger，代码行数:55，代码来源:kiss_fft.c

示例3: kf_bfly4

static void kf_bfly4(
    kiss_fft_cpx * Fout,
    const size_t fstride,
    const kiss_fft_cfg st,
    const size_t m
)
{
    kiss_fft_cpx *tw1,*tw2,*tw3;
    kiss_fft_cpx scratch[6];
    size_t k=m;
    const size_t m2=2*m;
    const size_t m3=3*m;


    tw3 = tw2 = tw1 = st->twiddles;

    do {
        C_FIXDIV(*Fout,4);
        C_FIXDIV(Fout[m],4);
        C_FIXDIV(Fout[m2],4);
        C_FIXDIV(Fout[m3],4);

        C_MUL(scratch[0],Fout[m] , *tw1 );
        C_MUL(scratch[1],Fout[m2] , *tw2 );
        C_MUL(scratch[2],Fout[m3] , *tw3 );

        C_SUB( scratch[5] , *Fout, scratch[1] );
        C_ADDTO(*Fout, scratch[1]);
        C_ADD( scratch[3] , scratch[0] , scratch[2] );
        C_SUB( scratch[4] , scratch[0] , scratch[2] );
        C_SUB( Fout[m2], *Fout, scratch[3] );
        tw1 += fstride;
        tw2 += fstride*2;
        tw3 += fstride*3;
        C_ADDTO( *Fout , scratch[3] );

        if(st->inverse) {
            Fout[m].r = scratch[5].r - scratch[4].i;
            Fout[m].i = scratch[5].i + scratch[4].r;
            Fout[m3].r = scratch[5].r + scratch[4].i;
            Fout[m3].i = scratch[5].i - scratch[4].r;
        } else {
            Fout[m].r = scratch[5].r + scratch[4].i;
            Fout[m].i = scratch[5].i - scratch[4].r;
            Fout[m3].r = scratch[5].r - scratch[4].i;
            Fout[m3].i = scratch[5].i + scratch[4].r;
        }
        ++Fout;
    } while(--k);
}
开发者ID:Biohazard90，项目名称:CorsairRGBSpectrumVisualizer，代码行数:50，代码来源:kiss_fft.c

示例4: kf_bfly4

static void kf_bfly4(
                     kiss_fft_cpx * Fout,
                     const size_t fstride,
                     const kiss_fft_state *st,
                     int m,
                     int N,
                     int mm
                    )
{
   const kiss_twiddle_cpx *tw1,*tw2,*tw3;
   kiss_fft_cpx scratch[6];
   const size_t m2=2*m;
   const size_t m3=3*m;
   int i, j;

   kiss_fft_cpx * Fout_beg = Fout;
   for (i=0;i<N;i++)
   {
      Fout = Fout_beg + i*mm;
      tw3 = tw2 = tw1 = st->twiddles;
      for (j=0;j<m;j++)
      {
         C_MUL4(scratch[0],Fout[m] , *tw1 );
         C_MUL4(scratch[1],Fout[m2] , *tw2 );
         C_MUL4(scratch[2],Fout[m3] , *tw3 );
             
         Fout->r = PSHR(Fout->r, 2);
         Fout->i = PSHR(Fout->i, 2);
         C_SUB( scratch[5] , *Fout, scratch[1] );
         C_ADDTO(*Fout, scratch[1]);
         C_ADD( scratch[3] , scratch[0] , scratch[2] );
         C_SUB( scratch[4] , scratch[0] , scratch[2] );
         Fout[m2].r = PSHR(Fout[m2].r, 2);
         Fout[m2].i = PSHR(Fout[m2].i, 2);
         C_SUB( Fout[m2], *Fout, scratch[3] );
         tw1 += fstride;
         tw2 += fstride*2;
         tw3 += fstride*3;
         C_ADDTO( *Fout , scratch[3] );
             
         Fout[m].r = scratch[5].r + scratch[4].i;
         Fout[m].i = scratch[5].i - scratch[4].r;
         Fout[m3].r = scratch[5].r - scratch[4].i;
         Fout[m3].i = scratch[5].i + scratch[4].r;
         ++Fout;
      }
   }
}
开发者ID:FreshLeaf8865，项目名称:mumble，代码行数:48，代码来源:kiss_fft.c

示例5: ki_bfly2

static void ki_bfly2(
                     kiss_fft_cpx * Fout,
                     const size_t fstride,
                     const kiss_fft_state *st,
                     int m,
                     int N,
                     int mm
                    )
{
   kiss_fft_cpx * Fout2;
   const kiss_twiddle_cpx * tw1;
   kiss_fft_cpx t;
   int i,j;
   kiss_fft_cpx * Fout_beg = Fout;
   for (i=0;i<N;i++)
   {
      Fout = Fout_beg + i*mm;
      Fout2 = Fout + m;
      tw1 = st->twiddles;
      for(j=0;j<m;j++)
      {
         C_MULC (t,  *Fout2 , *tw1);
         tw1 += fstride;
         C_SUB( *Fout2 ,  *Fout , t );
         C_ADDTO( *Fout ,  t );
         ++Fout2;
         ++Fout;
      }
   }
}
开发者ID:FreshLeaf8865，项目名称:mumble，代码行数:30，代码来源:kiss_fft.c

示例6: kf_bfly2

static void kf_bfly2(
        kiss_fft_cpx * Fout,
        const size_t fstride,
        const kiss_fft_cfg st,
        int m,
        int N,
        int mm
        )
{
    kiss_fft_cpx * Fout2;
    kiss_fft_cpx * tw1;
    kiss_fft_cpx t;
    if (!st->inverse) {
       int i,j;
       kiss_fft_cpx * Fout_beg = Fout;
       for (i=0;i<N;i++)
       {
          Fout = Fout_beg + i*mm;
          Fout2 = Fout + m;
          tw1 = st->twiddles;
          for(j=0;j<m;j++)
          {
             /* Almost the same as the code path below, except that we divide the input by two
              (while keeping the best accuracy possible) */
             ms_word32_t tr, ti;
             tr = SHR32(SUB32(MULT16_16(Fout2->r , tw1->r),MULT16_16(Fout2->i , tw1->i)), 1);
             ti = SHR32(ADD32(MULT16_16(Fout2->i , tw1->r),MULT16_16(Fout2->r , tw1->i)), 1);
             tw1 += fstride;
             Fout2->r = PSHR32(SUB32(SHL32(EXTEND32(Fout->r), 14), tr), 15);
             Fout2->i = PSHR32(SUB32(SHL32(EXTEND32(Fout->i), 14), ti), 15);
             Fout->r = PSHR32(ADD32(SHL32(EXTEND32(Fout->r), 14), tr), 15);
             Fout->i = PSHR32(ADD32(SHL32(EXTEND32(Fout->i), 14), ti), 15);
             ++Fout2;
             ++Fout;
          }
       }
    } else {
       int i,j;
       kiss_fft_cpx * Fout_beg = Fout;
       for (i=0;i<N;i++)
       {
          Fout = Fout_beg + i*mm;
          Fout2 = Fout + m;
          tw1 = st->twiddles;
          for(j=0;j<m;j++)
          {
             C_MUL (t,  *Fout2 , *tw1);
             tw1 += fstride;
             C_SUB( *Fout2 ,  *Fout , t );
             C_ADDTO( *Fout ,  t );
             ++Fout2;
             ++Fout;
          }
       }
    }
}
开发者ID:Amini-Philips，项目名称:mediastreamer2，代码行数:56，代码来源:kiss_fft.c

示例7: kf_bfly3

static void kf_bfly3(
                     kiss_fft_cpx * Fout,
                     const size_t fstride,
                     const kiss_fft_state *st,
                     int m,
                     int N,
                     int mm
                    )
{
   int i;
   size_t k;
   const size_t m2 = 2*m;
   const kiss_twiddle_cpx *tw1,*tw2;
   kiss_fft_cpx scratch[5];
   kiss_twiddle_cpx epi3;

   kiss_fft_cpx * Fout_beg = Fout;
#ifdef FIXED_POINT
   /*epi3.r = -16384;*/ /* Unused */
   epi3.i = -28378;
#else
   epi3 = st->twiddles[fstride*m];
#endif
   for (i=0;i<N;i++)
   {
      Fout = Fout_beg + i*mm;
      tw1=tw2=st->twiddles;
      /* For non-custom modes, m is guaranteed to be a multiple of 4. */
      k=m;
      do {

         C_MUL(scratch[1],Fout[m] , *tw1);
         C_MUL(scratch[2],Fout[m2] , *tw2);

         C_ADD(scratch[3],scratch[1],scratch[2]);
         C_SUB(scratch[0],scratch[1],scratch[2]);
         tw1 += fstride;
         tw2 += fstride*2;

         Fout[m].r = SUB32_ovflw(Fout->r, HALF_OF(scratch[3].r));
         Fout[m].i = SUB32_ovflw(Fout->i, HALF_OF(scratch[3].i));

         C_MULBYSCALAR( scratch[0] , epi3.i );

         C_ADDTO(*Fout,scratch[3]);

         Fout[m2].r = ADD32_ovflw(Fout[m].r, scratch[0].i);
         Fout[m2].i = SUB32_ovflw(Fout[m].i, scratch[0].r);

         Fout[m].r = SUB32_ovflw(Fout[m].r, scratch[0].i);
         Fout[m].i = ADD32_ovflw(Fout[m].i, scratch[0].r);

         ++Fout;
      } while(--k);
   }
}
开发者ID:Appsgeyser，项目名称:Custom-messenger，代码行数:56，代码来源:kiss_fft.c

示例8: kf_bfly3

static void kf_bfly3(
                     kiss_fft_cpx * Fout,
                     const size_t fstride,
                     const kiss_fft_state *st,
                     int m,
                     int N,
                     int mm
                    )
{
   int i;
   size_t k;
   const size_t m2 = 2*m;
   const kiss_twiddle_cpx *tw1,*tw2;
   kiss_fft_cpx scratch[5];
   kiss_twiddle_cpx epi3;

   kiss_fft_cpx * Fout_beg = Fout;
   epi3 = st->twiddles[fstride*m];
   for (i=0;i<N;i++)
   {
      Fout = Fout_beg + i*mm;
      tw1=tw2=st->twiddles;
      k=m;
      do {
         C_FIXDIV(*Fout,3); C_FIXDIV(Fout[m],3); C_FIXDIV(Fout[m2],3);

         C_MUL(scratch[1],Fout[m] , *tw1);
         C_MUL(scratch[2],Fout[m2] , *tw2);

         C_ADD(scratch[3],scratch[1],scratch[2]);
         C_SUB(scratch[0],scratch[1],scratch[2]);
         tw1 += fstride;
         tw2 += fstride*2;

         Fout[m].r = Fout->r - HALF_OF(scratch[3].r);
         Fout[m].i = Fout->i - HALF_OF(scratch[3].i);

         C_MULBYSCALAR( scratch[0] , epi3.i );

         C_ADDTO(*Fout,scratch[3]);

         Fout[m2].r = Fout[m].r + scratch[0].i;
         Fout[m2].i = Fout[m].i - scratch[0].r;

         Fout[m].r -= scratch[0].i;
         Fout[m].i += scratch[0].r;

         ++Fout;
      } while(--k);
   }
}
开发者ID:FreshLeaf8865，项目名称:mumble，代码行数:51，代码来源:kiss_fft.c

示例9: kf_bfly2

static void kf_bfly2(kiss_fft_cpx *Fout, const size_t fstride,
                     const kiss_fft_cfg st, int m) {
  kiss_fft_cpx *Fout2;
  kiss_fft_cpx *tw1 = st->twiddles;
  kiss_fft_cpx t;
  Fout2 = Fout + m;
  do {
    C_FIXDIV(*Fout, 2);
    C_FIXDIV(*Fout2, 2);

    C_MUL(t, *Fout2, *tw1);
    tw1 += fstride;
    C_SUB(*Fout2, *Fout, t);
    C_ADDTO(*Fout, t);
    ++Fout2;
    ++Fout;
  } while (--m);
}
开发者ID:AdmiralCurtiss，项目名称:dolphin，代码行数:18，代码来源:KissFFT.cpp

示例10: kf_bfly5

static void kf_bfly5(
                     kiss_fft_cpx * Fout,
                     const size_t fstride,
                     const kiss_fft_state *st,
                     int m,
                     int N,
                     int mm
                    )
{
   kiss_fft_cpx *Fout0,*Fout1,*Fout2,*Fout3,*Fout4;
   int i, u;
   kiss_fft_cpx scratch[13];
   const kiss_twiddle_cpx *tw;
   kiss_twiddle_cpx ya,yb;
   kiss_fft_cpx * Fout_beg = Fout;

#ifdef FIXED_POINT
   ya.r = 10126;
   ya.i = -31164;
   yb.r = -26510;
   yb.i = -19261;
#else
   ya = st->twiddles[fstride*m];
   yb = st->twiddles[fstride*2*m];
#endif
   tw=st->twiddles;

   for (i=0;i<N;i++)
   {
      Fout = Fout_beg + i*mm;
      Fout0=Fout;
      Fout1=Fout0+m;
      Fout2=Fout0+2*m;
      Fout3=Fout0+3*m;
      Fout4=Fout0+4*m;

      /* For non-custom modes, m is guaranteed to be a multiple of 4. */
      for ( u=0; u<m; ++u ) {
         scratch[0] = *Fout0;

         C_MUL(scratch[1] ,*Fout1, tw[u*fstride]);
         C_MUL(scratch[2] ,*Fout2, tw[2*u*fstride]);
         C_MUL(scratch[3] ,*Fout3, tw[3*u*fstride]);
         C_MUL(scratch[4] ,*Fout4, tw[4*u*fstride]);

         C_ADD( scratch[7],scratch[1],scratch[4]);
         C_SUB( scratch[10],scratch[1],scratch[4]);
         C_ADD( scratch[8],scratch[2],scratch[3]);
         C_SUB( scratch[9],scratch[2],scratch[3]);

         Fout0->r = ADD32_ovflw(Fout0->r, ADD32_ovflw(scratch[7].r, scratch[8].r));
         Fout0->i = ADD32_ovflw(Fout0->i, ADD32_ovflw(scratch[7].i, scratch[8].i));

         scratch[5].r = ADD32_ovflw(scratch[0].r, ADD32_ovflw(S_MUL(scratch[7].r,ya.r), S_MUL(scratch[8].r,yb.r)));
         scratch[5].i = ADD32_ovflw(scratch[0].i, ADD32_ovflw(S_MUL(scratch[7].i,ya.r), S_MUL(scratch[8].i,yb.r)));

         scratch[6].r =  ADD32_ovflw(S_MUL(scratch[10].i,ya.i), S_MUL(scratch[9].i,yb.i));
         scratch[6].i = NEG32_ovflw(ADD32_ovflw(S_MUL(scratch[10].r,ya.i), S_MUL(scratch[9].r,yb.i)));

         C_SUB(*Fout1,scratch[5],scratch[6]);
         C_ADD(*Fout4,scratch[5],scratch[6]);

         scratch[11].r = ADD32_ovflw(scratch[0].r, ADD32_ovflw(S_MUL(scratch[7].r,yb.r), S_MUL(scratch[8].r,ya.r)));
         scratch[11].i = ADD32_ovflw(scratch[0].i, ADD32_ovflw(S_MUL(scratch[7].i,yb.r), S_MUL(scratch[8].i,ya.r)));
         scratch[12].r = SUB32_ovflw(S_MUL(scratch[9].i,ya.i), S_MUL(scratch[10].i,yb.i));
         scratch[12].i = SUB32_ovflw(S_MUL(scratch[10].r,yb.i), S_MUL(scratch[9].r,ya.i));

         C_ADD(*Fout2,scratch[11],scratch[12]);
         C_SUB(*Fout3,scratch[11],scratch[12]);

         ++Fout0;++Fout1;++Fout2;++Fout3;++Fout4;
      }
   }
}
开发者ID:Appsgeyser，项目名称:Custom-messenger，代码行数:74，代码来源:kiss_fft.c

示例11: kf_bfly4

static void kf_bfly4(
                     kiss_fft_cpx * Fout,
                     const size_t fstride,
                     const kiss_fft_state *st,
                     int m,
                     int N,
                     int mm
                    )
{
   int i;

   if (m==1)
   {
      /* Degenerate case where all the twiddles are 1. */
      for (i=0;i<N;i++)
      {
         kiss_fft_cpx scratch0, scratch1;

         C_SUB( scratch0 , *Fout, Fout[2] );
         C_ADDTO(*Fout, Fout[2]);
         C_ADD( scratch1 , Fout[1] , Fout[3] );
         C_SUB( Fout[2], *Fout, scratch1 );
         C_ADDTO( *Fout , scratch1 );
         C_SUB( scratch1 , Fout[1] , Fout[3] );

         Fout[1].r = ADD32_ovflw(scratch0.r, scratch1.i);
         Fout[1].i = SUB32_ovflw(scratch0.i, scratch1.r);
         Fout[3].r = SUB32_ovflw(scratch0.r, scratch1.i);
         Fout[3].i = ADD32_ovflw(scratch0.i, scratch1.r);
         Fout+=4;
      }
   } else {
      int j;
      kiss_fft_cpx scratch[6];
      const kiss_twiddle_cpx *tw1,*tw2,*tw3;
      const int m2=2*m;
      const int m3=3*m;
      kiss_fft_cpx * Fout_beg = Fout;
      for (i=0;i<N;i++)
      {
         Fout = Fout_beg + i*mm;
         tw3 = tw2 = tw1 = st->twiddles;
         /* m is guaranteed to be a multiple of 4. */
         for (j=0;j<m;j++)
         {
            C_MUL(scratch[0],Fout[m] , *tw1 );
            C_MUL(scratch[1],Fout[m2] , *tw2 );
            C_MUL(scratch[2],Fout[m3] , *tw3 );

            C_SUB( scratch[5] , *Fout, scratch[1] );
            C_ADDTO(*Fout, scratch[1]);
            C_ADD( scratch[3] , scratch[0] , scratch[2] );
            C_SUB( scratch[4] , scratch[0] , scratch[2] );
            C_SUB( Fout[m2], *Fout, scratch[3] );
            tw1 += fstride;
            tw2 += fstride*2;
            tw3 += fstride*3;
            C_ADDTO( *Fout , scratch[3] );

            Fout[m].r = ADD32_ovflw(scratch[5].r, scratch[4].i);
            Fout[m].i = SUB32_ovflw(scratch[5].i, scratch[4].r);
            Fout[m3].r = SUB32_ovflw(scratch[5].r, scratch[4].i);
            Fout[m3].i = ADD32_ovflw(scratch[5].i, scratch[4].r);
            ++Fout;
         }
      }
   }
}
开发者ID:Appsgeyser，项目名称:Custom-messenger，代码行数:68，代码来源:kiss_fft.c

示例12: ki_bfly5

static void ki_bfly5(
                     kiss_fft_cpx * Fout,
                     const size_t fstride,
                     const kiss_fft_state *st,
                     int m,
                     int N,
                     int mm
                    )
{
   kiss_fft_cpx *Fout0,*Fout1,*Fout2,*Fout3,*Fout4;
   int i, u;
   kiss_fft_cpx scratch[13];
   const kiss_twiddle_cpx * twiddles = st->twiddles;
   const kiss_twiddle_cpx *tw;
   kiss_twiddle_cpx ya,yb;
   kiss_fft_cpx * Fout_beg = Fout;

   ya = twiddles[fstride*m];
   yb = twiddles[fstride*2*m];
   tw=st->twiddles;

   for (i=0;i<N;i++)
   {
      Fout = Fout_beg + i*mm;
      Fout0=Fout;
      Fout1=Fout0+m;
      Fout2=Fout0+2*m;
      Fout3=Fout0+3*m;
      Fout4=Fout0+4*m;

      for ( u=0; u<m; ++u ) {
         scratch[0] = *Fout0;

         C_MULC(scratch[1] ,*Fout1, tw[u*fstride]);
         C_MULC(scratch[2] ,*Fout2, tw[2*u*fstride]);
         C_MULC(scratch[3] ,*Fout3, tw[3*u*fstride]);
         C_MULC(scratch[4] ,*Fout4, tw[4*u*fstride]);

         C_ADD( scratch[7],scratch[1],scratch[4]);
         C_SUB( scratch[10],scratch[1],scratch[4]);
         C_ADD( scratch[8],scratch[2],scratch[3]);
         C_SUB( scratch[9],scratch[2],scratch[3]);

         Fout0->r += scratch[7].r + scratch[8].r;
         Fout0->i += scratch[7].i + scratch[8].i;

         scratch[5].r = scratch[0].r + S_MUL(scratch[7].r,ya.r) + S_MUL(scratch[8].r,yb.r);
         scratch[5].i = scratch[0].i + S_MUL(scratch[7].i,ya.r) + S_MUL(scratch[8].i,yb.r);

         scratch[6].r = -S_MUL(scratch[10].i,ya.i) - S_MUL(scratch[9].i,yb.i);
         scratch[6].i =  S_MUL(scratch[10].r,ya.i) + S_MUL(scratch[9].r,yb.i);

         C_SUB(*Fout1,scratch[5],scratch[6]);
         C_ADD(*Fout4,scratch[5],scratch[6]);

         scratch[11].r = scratch[0].r + S_MUL(scratch[7].r,yb.r) + S_MUL(scratch[8].r,ya.r);
         scratch[11].i = scratch[0].i + S_MUL(scratch[7].i,yb.r) + S_MUL(scratch[8].i,ya.r);
         scratch[12].r =  S_MUL(scratch[10].i,yb.i) - S_MUL(scratch[9].i,ya.i);
         scratch[12].i = -S_MUL(scratch[10].r,yb.i) + S_MUL(scratch[9].r,ya.i);

         C_ADD(*Fout2,scratch[11],scratch[12]);
         C_SUB(*Fout3,scratch[11],scratch[12]);

         ++Fout0;++Fout1;++Fout2;++Fout3;++Fout4;
      }
   }
}
开发者ID:FreshLeaf8865，项目名称:mumble，代码行数:67，代码来源:kiss_fft.c


注：本文中的C_SUB函数示例由纯净天空整理自Github/MSDocs等开源代码及文档管理平台，相关代码片段筛选自各路编程大神贡献的开源项目，源码版权归原作者所有，传播和使用请参考对应项目的License；未经允许，请勿转载。