/*
next -> [entry_point]
[size]
[return address] -- x86 only, backend adds 1 to each spill location
[spill area]
...
frame -> [entry_point]
[size]
*/
void operator()(stack_frame *frame)
{
cell return_address = parent->frame_offset(frame);
if(return_address == (cell)-1)
return;
code_block *compiled = visitor->fixup.translate_code(parent->frame_code(frame));
gc_info *info = compiled->block_gc_info();
assert(return_address < compiled->size());
cell callsite = info->return_address_index(return_address);
if(callsite == (cell)-1)
return;
#ifdef DEBUG_GC_MAPS
std::cout << "call frame code block " << compiled << " with offset " << return_address << std::endl;
#endif
cell *stack_pointer = (cell *)(parent->frame_successor(frame) + 1);
u8 *bitmap = info->gc_info_bitmap();
/* Subtract old value of base pointer from every derived pointer. */
for(cell spill_slot = 0; spill_slot < info->derived_root_count; spill_slot++)
{
u32 base_pointer = info->lookup_base_pointer(callsite, spill_slot);
if(base_pointer != (u32)-1)
{
#ifdef DEBUG_GC_MAPS
std::cout << "visiting derived root " << spill_slot
<< " with base pointer " << base_pointer
<< std::endl;
#endif
stack_pointer[spill_slot] -= stack_pointer[base_pointer];
}
}
/* Update all GC roots, including base pointers. */
cell callsite_gc_roots = info->callsite_gc_roots(callsite);
for(cell spill_slot = 0; spill_slot < info->gc_root_count; spill_slot++)
{
if(bitmap_p(bitmap,callsite_gc_roots + spill_slot))
{
#ifdef DEBUG_GC_MAPS
std::cout << "visiting GC root " << spill_slot << std::endl;
#endif
visitor->visit_handle(stack_pointer + spill_slot);
}
}
/* Add the base pointers to obtain new derived pointer values. */
for(cell spill_slot = 0; spill_slot < info->derived_root_count; spill_slot++)
{
u32 base_pointer = info->lookup_base_pointer(callsite, spill_slot);
if(base_pointer != (u32)-1)
stack_pointer[spill_slot] += stack_pointer[base_pointer];
}
}
/*
next -> [entry_point]
[size]
[return address] -- x86 only, backend adds 1 to each spill location
[spill area]
...
frame -> [entry_point]
[size]
*/
void operator()(stack_frame *frame)
{
cell return_address = parent->frame_offset(frame);
if(return_address == (cell)-1)
return;
code_block *compiled = visitor->fixup.translate_code(parent->frame_code(frame));
gc_info *info = compiled->block_gc_info();
assert(return_address < compiled->size());
int index = info->return_address_index(return_address);
if(index == -1)
return;
u8 *bitmap = info->gc_info_bitmap();
cell base = info->spill_slot_base(index);
cell *stack_pointer = (cell *)(parent->frame_successor(frame) + 1);
for(cell spill_slot = 0; spill_slot < info->gc_root_count; spill_slot++)
{
if(bitmap_p(bitmap,base + spill_slot))
visitor->visit_handle(&stack_pointer[spill_slot]);
}
}
