Function philox_next

numpy/random/src/philox/philox.h:202–230

} philox_state;

static inline uint64_t philox_next(philox_state *state) {
  uint64_t out;
  int i;
  philox4x64_ctr_t ct;

  if (state->buffer_pos < PHILOX_BUFFER_SIZE) {
    out = state->buffer[state->buffer_pos];
    state->buffer_pos++;
    return out;
  }
  /* generate 4 new uint64_t */
  state->ctr->v[0]++;
  /* Handle carry */
  if (state->ctr->v[0] == 0) {
    state->ctr->v[1]++;
    if (state->ctr->v[1] == 0) {
      state->ctr->v[2]++;
      if (state->ctr->v[2] == 0) {
        state->ctr->v[3]++;
      }
    }
  }
  ct = philox4x64_R(philox4x64_rounds, *state->ctr, *state->key);
  for (i = 0; i < 4; i++) {
    state->buffer[i] = ct.v[i];
  }
  state->buffer_pos = 1;
  return state->buffer[0];
}

static inline uint64_t philox_next64(philox_state *state) {
  return philox_next(state);