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  /*! \file silk_Inlines.h
   *  \brief silk_Inlines.h defines OPUS_INLINE signal processing functions.
   */
  
  #ifndef SILK_FIX_INLINES_H
  #define SILK_FIX_INLINES_H
  
  #ifdef  __cplusplus
  extern "C"
  {
  #endif
  
  /* count leading zeros of opus_int64 */
  static OPUS_INLINE opus_int32
  silk_CLZ64( opus_int64
  in )
  {
  opus_int32 in_upper;
  
  in_upper = (opus_int32) silk_RSHIFT64(in, 32);
  if (in_upper == 0) {
  /* Search in the lower 32 bits */
  return 32 +
  silk_CLZ32((opus_int32)
  in );
  } else {
  /* Search in the upper 32 bits */
  return
  silk_CLZ32( in_upper );
  }
  }
  
  /* get number of leading zeros and fractional part (the bits right after the leading one */
  static OPUS_INLINE void silk_CLZ_FRAC(
          opus_int32 in,            /* I  input                               */
          opus_int32 *lz,           /* O  number of leading zeros             */
          opus_int32 *frac_Q7       /* O  the 7 bits right after the leading one */
  ) {
      opus_int32 lzeros = silk_CLZ32(in);
  
      *lz = lzeros;
      *frac_Q7 = silk_ROR32(in, 24 - lzeros) & 0x7f;
  }
  
  /* Approximation of square root                                          */
  /* Accuracy: < +/- 10%  for output values > 15                           */
  /*           < +/- 2.5% for output values > 120                          */
  static OPUS_INLINE opus_int32
  silk_SQRT_APPROX( opus_int32
  x )
  {
  opus_int32 y, lz, frac_Q7;
  
  if( x <= 0 ) {
  return 0;
  }
  
  silk_CLZ_FRAC(x, &lz, &frac_Q7
  );
  
  if( lz & 1 ) {
  y = 32768;
  } else {
  y = 46214;        /* 46214 = sqrt(2) * 32768 */
  }
  
  /* get scaling right */
  y >>=
  silk_RSHIFT(lz,
  1);
  
  /* increment using fractional part of input */
  y = silk_SMLAWB(y, y, silk_SMULBB(213, frac_Q7));
  
  return
  y;
  }
  
  /* Divide two int32 values and return result as int32 in a given Q-domain */
  static OPUS_INLINE opus_int32
  
  silk_DIV32_varQ(   /* O    returns a good approximation of "(a32 << Qres) / b32" */
          const opus_int32 a32,               /* I    numerator (Q0)                  */
          const opus_int32 b32,               /* I    denominator (Q0)                */
          const opus_int Qres               /* I    Q-domain of result (>= 0)       */
  ) {
      opus_int a_headrm, b_headrm, lshift;
      opus_int32 b32_inv, a32_nrm, b32_nrm, result;
  
      silk_assert(b32 != 0);
      silk_assert(Qres >= 0);
  
      /* Compute number of bits head room and normalize inputs */
      a_headrm = silk_CLZ32(silk_abs(a32)) - 1;
      a32_nrm = silk_LSHIFT(a32,
                            a_headrm);                                       /* Q: a_headrm                  */
      b_headrm = silk_CLZ32(silk_abs(b32)) - 1;
      b32_nrm = silk_LSHIFT(b32,
                            b_headrm);                                       /* Q: b_headrm                  */
  
      /* Inverse of b32, with 14 bits of precision */
      b32_inv = silk_DIV32_16(silk_int32_MAX >> 2,
                              silk_RSHIFT(b32_nrm, 16));   /* Q: 29 + 16 - b_headrm        */
  
      /* First approximation */
      result = silk_SMULWB(a32_nrm,
                           b32_inv);                                     /* Q: 29 + a_headrm - b_headrm  */
  
      /* Compute residual by subtracting product of denominator and first approximation */
      /* It's OK to overflow because the final value of a32_nrm should always be small */
      a32_nrm = silk_SUB32_ovflw(a32_nrm, silk_LSHIFT_ovflw(silk_SMMUL(b32_nrm, result),
                                                            3));  /* Q: a_headrm   */
  
      /* Refinement */
      result = silk_SMLAWB(result, a32_nrm,
                           b32_inv);                             /* Q: 29 + a_headrm - b_headrm  */
  
      /* Convert to Qres domain */
      lshift = 29 + a_headrm - b_headrm - Qres;
      if (lshift < 0) {
          return silk_LSHIFT_SAT32(result, -lshift);
      } else {
          if (lshift < 32) {
              return silk_RSHIFT(result, lshift);
          } else {
              /* Avoid undefined result */
              return 0;
          }
      }
  }
  
  /* Invert int32 value and return result as int32 in a given Q-domain */
  static OPUS_INLINE opus_int32
  
  silk_INVERSE32_varQ(   /* O    returns a good approximation of "(1 << Qres) / b32" */
          const opus_int32 b32,                   /* I    denominator (Q0)                */
          const opus_int Qres                   /* I    Q-domain of result (> 0)        */
  ) {
      opus_int b_headrm, lshift;
      opus_int32 b32_inv, b32_nrm, err_Q32, result;
  
      silk_assert(b32 != 0);
      silk_assert(Qres > 0);
  
      /* Compute number of bits head room and normalize input */
      b_headrm = silk_CLZ32(silk_abs(b32)) - 1;
      b32_nrm = silk_LSHIFT(b32,
                            b_headrm);                                       /* Q: b_headrm                */
  
      /* Inverse of b32, with 14 bits of precision */
      b32_inv = silk_DIV32_16(silk_int32_MAX >> 2,
                              silk_RSHIFT(b32_nrm, 16));   /* Q: 29 + 16 - b_headrm    */
  
      /* First approximation */
      result = silk_LSHIFT(b32_inv,
                           16);                                          /* Q: 61 - b_headrm            */
  
      /* Compute residual by subtracting product of denominator and first approximation from one */
      err_Q32 = silk_LSHIFT(((opus_int32) 1 << 29) - silk_SMULWB(b32_nrm, b32_inv),
                            3);        /* Q32                        */
  
      /* Refinement */
      result = silk_SMLAWW(result, err_Q32,
                           b32_inv);                             /* Q: 61 - b_headrm            */
  
      /* Convert to Qres domain */
      lshift = 61 - b_headrm - Qres;
      if (lshift <= 0) {
          return silk_LSHIFT_SAT32(result, -lshift);
      } else {
          if (lshift < 32) {
              return silk_RSHIFT(result, lshift);
          } else {
              /* Avoid undefined result */
              return 0;
          }
      }
  }
  
  #ifdef  __cplusplus
  }
  #endif
  
  #endif /* SILK_FIX_INLINES_H */
  