int8_t s = (param_gain >> 24) + 4;
uint8_t ei = param_gain >> 16;
int32_t gain;
if (s >= 0)
  gain = expt[ei] << s;
else
  gain = expt[ei] >> (-s);

// reads from the lookup table (interpolated)
bool invert = (inlet_in <= 0.0);
s32 fractional;
s32 left;
s32 right;
s32 inputRect = ___SMMUL(gain, (invert ? -inlet_in : inlet_in)) << 6;

if (inputRect <= (8 << 21)) {
  s32 integral = (inputRect >> 15);
  s32 tableIdx = (integral > 0x1FF) ? 0x1FF : integral;
  fractional = (inputRect - (integral << 15)) << 12;
  left = lutTSGDiodeSatSmall[tableIdx];
  right = lutTSGDiodeSatSmall[tableIdx + 1];
} else {
  s32 integral = (inputRect >> 19);
  s32 tableIdx = (integral > 0x1FF) ? 0x1FF : integral;
  fractional = (inputRect - (integral << 19)) << 10;
  // lowest 64 indices are contained in the small table
  // to avoid duplicate data
  left = lutTSGDiodeSatBig[tableIdx - 64];
  right = lutTSGDiodeSatBig[tableIdx - 64 + 1];
}

int64_t a = (int64_t)right * fractional;
a += (int64_t)left * ((64 << 21) - fractional);
outlet_out = a >> 27;

if (invert)
  outlet_out = -outlet_out;