apps/plugins/fft/math.h

   1 #ifndef __MATH_H_
   2 #define __MATH_H_
   3
   4 #include <inttypes.h>
   5 #include <math.h>
   6 #include "lib/fixedpoint.h"
   7
   8 #define Q_MUL(a, b, bits) (( (int64_t) (a) * (int64_t) (b) ) >> (bits))
   9 #define Q15_MUL(a, b) Q_MUL(a,b,15)
  10 #define Q16_MUL(a, b) Q_MUL(a,b,16)
  11
  12 #define Q_DIV(a, b, bits) ( (((int64_t) (a)) << (bits)) / (b) )
  13 #define Q15_DIV(a, b) Q_DIV(a,b,15)
  14 #define Q16_DIV(a, b) Q_DIV(a,b,16)
  15
  16 #define float_q(a, bits) (int32_t)( ((float)(a)) *(1<<(bits)))
  17 #define float_q15(a) float_q(a, 15)
  18 #define float_q16(a) float_q(a, 16)
  19
  20 /**
  21  * Fixed point square root via Newton-Raphson.
  22  * @param a square root argument.
  23  * @param fracbits specifies number of fractional bits in argument.
  24  * @return Square root of argument in same fixed point format as input.
  25  */
  26 int64_t fsqrt64(int64_t a, unsigned int fracbits);
  27
  28 #endif