vm/gc_info.hpp

   1 namespace factor
   2 {
   3
   4 const u32 gc_info_missing_value = (u32)-1;
   5
   6 struct gc_info {
   7         u32 scrub_d_count;
   8         u32 scrub_r_count;
   9         u32 gc_root_count;
  10         u32 derived_root_count;
  11         u32 return_address_count;
  12
  13         cell callsite_bitmap_size()
  14         {
  15                 return scrub_d_count + scrub_r_count + gc_root_count;
  16         }
  17
  18         cell total_bitmap_size()
  19         {
  20                 return return_address_count * callsite_bitmap_size();
  21         }
  22
  23         cell total_bitmap_bytes()
  24         {
  25                 return ((total_bitmap_size() + 7) / 8);
  26         }
  27
  28         u32 *return_addresses()
  29         {
  30                 return (u32 *)this - return_address_count;
  31         }
  32
  33         u32 *base_pointer_map()
  34         {
  35                 return return_addresses() - return_address_count * derived_root_count;
  36         }
  37
  38         u8 *gc_info_bitmap()
  39         {
  40                 return (u8 *)base_pointer_map() - total_bitmap_bytes();
  41         }
  42
  43         cell callsite_scrub_d(cell index)
  44         {
  45                 return index * scrub_d_count;
  46         }
  47
  48         cell callsite_scrub_r(cell index)
  49         {
  50                 return return_address_count * scrub_d_count +
  51                         index * scrub_r_count;
  52         }
  53
  54         cell callsite_gc_roots(cell index)
  55         {
  56                 return return_address_count * scrub_d_count
  57                         + return_address_count * scrub_r_count
  58                         + index * gc_root_count;
  59         }
  60
  61         cell lookup_base_pointer(cell index, cell derived_root)
  62         {
  63                 return base_pointer_map()[index * derived_root_count + derived_root];
  64         }
  65
  66         cell return_address_index(cell return_address);
  67 };
  68
  69 }