// val div by two => x*2
// delay q32
int32_t val(uint32_t p32) {
  uint8_t p0 = p32 >> 24;
  p0 += ind;
  uint8_t p1 = p0 + 1;
  // return ___SMMLA((delay & 0x00FFFFFF)<<7, d[p1] - d[p0], d[p0]>>1);
  return ___SMMLA((delay << 7) & 0x7FFFFFFF, d[p1] - d[p0], d[p0] >> 1);
}
int32_t d[256];
int32_t delay;
uint8_t ind;
int32_t y, dc;

delay = ind = y = dc = 0;

int32_t ndelay = __USAT(inlet_delay, 27); // sq27
// 1/3     = 1431655765 q32
// 1/5     =  858993459 q32
// 1/6 715827882
// 1/sqrt5 = 1920767766 q32
ndelay = ___SMMUL(ndelay, 1431655765); //  1/3
int32_t ddelay = (ndelay - delay) >> 4;
int32_t fb = __USAT(inlet_fb, 27) << 4;

ind--;
// int32_t x = inlet_in>>3;
int32_t x = ___SMMLA(__SSAT(y, 27), fb, inlet_in >> 1) << 1;
d[ind] = x << 1;
delay += ddelay;
uint32_t p32 = delay << 5; // uq32

// outlet_out = (x+val(p32))>>1;
outlet_out = y = (x + 2 * val(p32) + val(2 * p32)) >> 2;
dc = ___SMMLA(0x00200000, y - dc, dc);
y -= dc;

// outlet_out = y = x + 3 * (val(p32) + val(2*p32)) + val(3*p32);
// outlet_out = y = x + 3 * (-val(p32) + val(2*p32)) - val(3*p32);
/*
outlet_out = y = x + 4 * (val(p32) + val(3*p32)) + 6*val(2*p32) + val(4*p32);

*/