vm/gc_info.hpp

   1 namespace factor {
   2
   3 struct gc_info {
   4   uint32_t scrub_d_count;
   5   uint32_t scrub_r_count;
   6   uint32_t gc_root_count;
   7   uint32_t derived_root_count;
   8   uint32_t return_address_count;
   9
  10   cell callsite_bitmap_size() {
  11     return scrub_d_count + scrub_r_count + gc_root_count;
  12   }
  13
  14   cell total_bitmap_size() {
  15     return return_address_count * callsite_bitmap_size();
  16   }
  17
  18   cell total_bitmap_bytes() { return ((total_bitmap_size() + 7) / 8); }
  19
  20   uint32_t* return_addresses() {
  21     return (uint32_t*)this - return_address_count;
  22   }
  23
  24   uint32_t* base_pointer_map() {
  25     return return_addresses() - return_address_count * derived_root_count;
  26   }
  27
  28   uint8_t* gc_info_bitmap() {
  29     return (uint8_t*)base_pointer_map() - total_bitmap_bytes();
  30   }
  31
  32   cell callsite_scrub_d(cell index) { return index * scrub_d_count; }
  33
  34   cell callsite_scrub_r(cell index) {
  35     return return_address_count * scrub_d_count + index * scrub_r_count;
  36   }
  37
  38   cell callsite_gc_roots(cell index) {
  39     return return_address_count * scrub_d_count +
  40            return_address_count * scrub_r_count + index * gc_root_count;
  41   }
  42
  43   uint32_t lookup_base_pointer(cell index, cell derived_root) {
  44     return base_pointer_map()[index * derived_root_count + derived_root];
  45   }
  46
  47   cell return_address_index(cell return_address);
  48 };
  49
  50 }