AdaptiveMap.cpp

#include "AdaptiveMap.hpp"

AdaptiveMap::AdaptiveMap(const Shared* const sh, const int n, const int lim) : shared(sh), t(n), limit(lim) {
#ifdef VERBOSE
  printf("Created AdaptiveMap with n = %d, lim = %d\n", n, lim);
#endif
  dt = DivisionTable::getDT();
}

void AdaptiveMap::update(uint32_t *const p) {
  uint32_t p0 = p[0];
  const int n = p0 & 1023U; //count
  const int pr = p0 >> 10U; //prediction (22-bit fractional part)
  if( n < limit ) {
    ++p0;
  } else {
    p0 = (p0 & 0xfffffc00U) | limit;
  }
  INJECT_SHARED_y
  const int target = y << 22U; //(22-bit fractional part)
  const int delta = ((target - pr) >> 3U) * dt[n]; //the larger the count (n) the less it should adapt pr+=(target-pr)/(n+1.5)
  p0 += delta & 0xfffffc00U;
  p[0] = p0;
}

void AdaptiveMap::setLimit(const int lim) { limit = lim; }