vm/gc_info.hpp

   1 namespace factor {
   2
   3 // gc_info should be kept in sync with:
   4 //   basis/compiler/codegen/gc-maps/gc-maps.factor
   5 //   basis/vm/vm.factor
   6 struct gc_info {
   7   uint32_t gc_root_count;
   8   uint32_t derived_root_count;
   9   uint32_t return_address_count;
  10
  11   cell callsite_bitmap_size() {
  12     return gc_root_count;
  13   }
  14
  15   cell total_bitmap_size() {
  16     return return_address_count * callsite_bitmap_size();
  17   }
  18
  19   cell total_bitmap_bytes() { return ((total_bitmap_size() + 7) / 8); }
  20
  21   uint32_t* return_addresses() {
  22     return (uint32_t*)this - return_address_count;
  23   }
  24
  25   uint32_t* base_pointer_map() {
  26     return return_addresses() - return_address_count * derived_root_count;
  27   }
  28
  29   uint8_t* gc_info_bitmap() {
  30     return (uint8_t*)base_pointer_map() - total_bitmap_bytes();
  31   }
  32
  33
  34   cell callsite_gc_roots(cell index) {
  35     return index * gc_root_count;
  36   }
  37
  38   uint32_t lookup_base_pointer(cell index, cell derived_root) {
  39     return base_pointer_map()[index * derived_root_count + derived_root];
  40   }
  41
  42   cell return_address_index(cell return_address) {
  43     uint32_t* return_address_array = return_addresses();
  44
  45     for (cell i = 0; i < return_address_count; i++) {
  46       if (return_address == return_address_array[i])
  47         return i;
  48     }
  49
  50     return (cell)-1;
  51   }
  52 };
  53
  54 }