kernel/utility.cpp


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#include <mercury/kernel/utility.hpp>

namespace mercury::kernel::utility {

  void mark_bitmap_region_zero(
      uint64_t *bitmap, uint64_t start_i, uint64_t end_i) {

    if (start_i % 64 != 0) {
      uint64_t keep = (1 << (start_i % 64)) - 1;
      bitmap[start_i / 64] &= keep;
      start_i = (start_i / 64 + 1) * 64;
    }

    if (end_i % 64 != 0) {
      uint64_t replace = (1 << (end_i % 64)) - 1;
      bitmap[end_i / 64] &= ~replace;
      end_i = (end_i / 64) * 64;
    }

    for (uint64_t i = start_i / 64; i < end_i / 64; ++i)
      bitmap[i] = 0;

  }

  void mark_bitmap_region_one(
      uint64_t *bitmap, uint64_t start_i, uint64_t end_i) {

    if (start_i % 64 != 0) {
      uint64_t keep = (1 << (start_i % 64)) - 1;
      bitmap[start_i / 64] |= ~keep;
      start_i = (start_i / 64 + 1) * 64;
    }

    if (end_i % 64 != 0) {
      uint64_t replace = (1 << (end_i % 64)) - 1;
      bitmap[end_i / 64] |= replace;
      end_i = (end_i / 64) * 64;
    }

    for (uint64_t i = start_i / 64; i < end_i / 64; ++i)
      bitmap[i] = 0xffffffffffffffff;

  }

}