예제 #1
0
// The cache_entries parameter is empty (on cold call site) or has entries
// (on cache miss). Called from assembly with the actual return address.
// Compilation of the inline cache may trigger a GC, which may trigger a
// compaction;
// also, the block containing the return address may now be dead. Use a
// code_root to take care of the details.
// Allocates memory
cell factor_vm::inline_cache_miss(cell return_address_) {
  code_root return_address(return_address_, this);
  bool tail_call_site = tail_call_site_p(return_address.value);

#ifdef PIC_DEBUG
  FACTOR_PRINT("Inline cache miss at "
               << (tail_call_site ? "tail" : "non-tail")
               << " call site 0x" << std::hex << return_address.value
               << std::dec);
  print_callstack();
#endif

  data_root<array> cache_entries(ctx->pop(), this);
  fixnum index = untag_fixnum(ctx->pop());
  data_root<array> methods(ctx->pop(), this);
  data_root<word> generic_word(ctx->pop(), this);
  data_root<object> object(((cell*)ctx->datastack)[-index], this);

  cell pic_size = array_capacity(cache_entries.untagged()) / 2;

  update_pic_transitions(pic_size);

  cell xt = generic_word->entry_point;
  if (pic_size < max_pic_size) {
    cell klass = object_class(object.value());
    cell method = lookup_method(object.value(), methods.value());

    data_root<array> new_cache_entries(
        add_inline_cache_entry(cache_entries.value(), klass, method), this);

    inline_cache_jit jit(generic_word.value(), this);
    jit.emit_inline_cache(index, generic_word.value(), methods.value(),
                          new_cache_entries.value(), tail_call_site);
    code_block* code = jit.to_code_block(CODE_BLOCK_PIC, JIT_FRAME_SIZE);
    initialize_code_block(code);
    xt = code->entry_point();
  }

  // Install the new stub.
  if (return_address.valid) {
    // 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.value);
    set_call_target(return_address.value, xt);

#ifdef PIC_DEBUG
    FACTOR_PRINT("Updated " << (tail_call_site ? "tail" : "non-tail")
                 << " call site 0x" << std::hex << return_address.value << std::dec
                 << " with 0x" << std::hex << (cell)xt << std::dec);
    print_callstack();
#endif
  }

  return xt;
}
예제 #2
0
/* 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;
}