static void check_frame(stack_frame *frame)
{
#ifdef FACTOR_DEBUG
check_code_pointer((cell)frame->xt);
assert(frame->size != 0);
#endif
}
void factor_vm::check_frame(stack_frame *frame)
{
#ifdef FACTOR_DEBUG
check_code_pointer((cell)frame->entry_point);
assert(frame->size != 0);
#endif
}
/* The cache_entries parameter is either f (on cold call site) or an array (on cache miss).
Called from assembly with the actual return address */
void *factor_vm::inline_cache_miss(cell return_address)
{
check_code_pointer(return_address);
/* Since each PIC is only referenced from a single call site,
if the old call target was a PIC, we can deallocate it immediately,
instead of leaving dead PICs around until the next GC. */
deallocate_inline_cache(return_address);
gc_root<array> cache_entries(dpop(),this);
fixnum index = untag_fixnum(dpop());
gc_root<array> methods(dpop(),this);
gc_root<word> generic_word(dpop(),this);
gc_root<object> object(((cell *)ds)[-index],this);
void *xt;
cell pic_size = inline_cache_size(cache_entries.value());
update_pic_transitions(pic_size);
if(pic_size >= max_pic_size)
xt = megamorphic_call_stub(generic_word.value());
else
{
cell klass = object_class(object.value());
cell method = lookup_method(object.value(),methods.value());
gc_root<array> new_cache_entries(add_inline_cache_entry(
cache_entries.value(),
klass,
method),this);
xt = compile_inline_cache(index,
generic_word.value(),
methods.value(),
new_cache_entries.value(),
tail_call_site_p(return_address))->xt();
}
/* Install the new stub. */
set_call_target(return_address,xt);
#ifdef PIC_DEBUG
printf("Updated %s call site 0x%lx with 0x%lx\n",
tail_call_site_p(return_address) ? "tail" : "non-tail",
return_address,
(cell)xt);
#endif
return xt;
}
void factor_vm::deallocate_inline_cache(cell return_address)
{
/* Find the call target. */
void *old_xt = get_call_target(return_address);
check_code_pointer((cell)old_xt);
code_block *old_block = (code_block *)old_xt - 1;
cell old_type = old_block->type();
#ifdef FACTOR_DEBUG
/* The call target was either another PIC,
or a compiled quotation (megamorphic stub) */
assert(old_type == PIC_TYPE || old_type == QUOTATION_TYPE);
#endif
if(old_type == PIC_TYPE)
code->code_heap_free(old_block);
}
