公开(公告)号：US4454579A

公开(公告)日：1984-06-12

申请号：US302322

申请日：1981-09-11

申请人： John F. Pilat ,  Douglas M. Wells ,  Eric Hamilton ,  J. Theodore Compton

发明人： John F. Pilat ,  Douglas M. Wells ,  Eric Hamilton ,  J. Theodore Compton

IPC分类号： G06F9/40

CPC分类号： G06F9/4425

摘要： An improved system for performing call and return operations in a computer system in which every call and return operation changes the program counter and the frame pointer but some call and return operations change other state. Included in the state which may change in the computer system of the present invention is addresses used in calculating other addresses, an identifier specifying which instruction set the processor is executing, and protection state which determines what data may be accessed during execution of a procedure. In the system, the state saved and restored in the call and return operations is divided into basic state saved and restored on every call and return and extended state saved and restored on only some calls and returns. The frame associated with an execution accordingly contains either saved basic state or saved basic state and saved extended state. The frame further contains a frame type item in each frame which specifies whether it contains only basic state or both basic and extended state. There are two call instructions and a single return instruction. The system responds to one call instruction, the neighborhood call instruction, by saving and setting only basic state; it responds to the other, the general call instruction, by saving and setting both basic state and extended state, and if necessary, saving and setting protection state. The processor responds to the single return instruction and the frame type specifier by restoring the state specified in the frame type specifier.

摘要翻译： 一种用于在计算机系统中执行呼叫和返回操作的改进的系统，其中每个呼叫和返回操作改变程序计数器和帧指针，但是一些调用和返回操作改变其他状态。 包括在本发明的计算机系统中可能改变的状态是用于计算其他地址的地址，指定处理器正在执行哪个指令集的标识符，以及确定在执行过程期间可以访问哪些数据的保护状态。 在系统中，在调用和返回操作中保存和恢复的状态被分为基本状态，每次调用恢复并恢复，并且仅在一些调用和返回时保存并恢复扩展状态。 与执行相关联的帧相应地包含保存的基本状态或保存的基本状态并保存扩展状态。 该帧还包括每帧中的帧类型项目，其指定它是仅包含基本状态还是包含基本状态和扩展状态。 有两个呼叫指令和单个返回指令。 系统通过仅保存和设置基本状态来响应一个呼叫指令，邻居呼叫指令; 它通过保存和设置基本状态和扩展状态来响应另一个通用呼叫指令，如果需要，保存并设置保护状态。 处理器通过恢复帧类型说明符中指定的状态来响应单个返回指令和帧类型说明符。