vm/gc_info.hpp

   1 namespace factor {
   2
   3 struct gc_info {
   4   u32 scrub_d_count;
   5   u32 scrub_r_count;
   6   u32 gc_root_count;
   7   u32 derived_root_count;
   8   u32 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   u32* return_addresses() { return (u32*)this - return_address_count; }
  21
  22   u32* base_pointer_map() {
  23     return return_addresses() - return_address_count * derived_root_count;
  24   }
  25
  26   u8* gc_info_bitmap() {
  27     return (u8*)base_pointer_map() - total_bitmap_bytes();
  28   }
  29
  30   cell callsite_scrub_d(cell index) { return index * scrub_d_count; }
  31
  32   cell callsite_scrub_r(cell index) {
  33     return return_address_count * scrub_d_count + index * scrub_r_count;
  34   }
  35
  36   cell callsite_gc_roots(cell index) {
  37     return return_address_count * scrub_d_count +
  38            return_address_count * scrub_r_count + index * gc_root_count;
  39   }
  40
  41   u32 lookup_base_pointer(cell index, cell derived_root) {
  42     return base_pointer_map()[index * derived_root_count + derived_root];
  43   }
  44
  45   cell return_address_index(cell return_address);
  46 };
  47
  48 }