Bugs found during limbo compiler work - Ref counting mistakes in vm_array copy_from() - document perf opportunity - Multiple bugs in addc instruction - set_rune() on vm_string was creating non-null terminated strings - Add support for '*', 'c', and 'u' flags in print formatting

arr committed 9 years ago

Commit 57e9d241 parent 3f81a2c4 files · +86 −44Browse files

Showing the changes to src/vm/array.cpp (1 of 4 files). Show all

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@@ -171,18 +171,26 @@ void vm_array_t::copy_from(const vm_array_t &source, word_t this_begin_index) · 170 unmodified lines
171	171
172	172	auto dest_arr = _arr + (this_begin_index * _element_type->size_in_bytes);
173	173
174		− // Increment all pointers if we have reference types.
	174	+ // If we have reference types, increment references in the
	175	+ // source array and decrement them in the destination array.
175	176	if (_element_type->map_in_bytes != 0)
176	177	{
177		− auto &type_desc = *_element_type;
	178	+ // [PERF] There is a chance this copy is within the same array, therefore
	179	+ // a check could be made to not ref count memory that is going to be moved.
	180	+ // The Inferno implementation of slicela handles this case (libinterp/xec.c).
	181	+ const auto &type_desc = *_element_type;
178	182	auto source_array_element = source._arr;
	183	+ auto dest_array_element = dest_arr;
179	184	for (auto i = word_t{ 0 }; i < source._length; ++i)
180	185	{
181		− source_array_element += (i * type_desc.size_in_bytes);
182	186	inc_ref_count_in_memory(type_desc, source_array_element);
	187	+ source_array_element += type_desc.size_in_bytes;
	188	+
	189	+ destroy_memory(type_desc, dest_array_element);
	190	+ dest_array_element += type_desc.size_in_bytes;
183	191	}
184	192	}
185	193
186		− // Moving data within the same array is permitted so use memmove().
	194	+ // Copy data from within the same array is permitted.
187	195	std::memmove(dest_arr, source._arr, (source._length * _element_type->size_in_bytes));
188	196	}