METHOD FOR PROCESSING STACK OF PROLOG MACHINE

摘要

PURPOSE:To simplify an allocating processing by determining a survival sequence from the variable used for the argument of a main body part goal with a compiler and executing the allocation to the value cell permanent variable register of an environment frame in the generation sequence. CONSTITUTION:At a stack area, the selecting point frame of a procedure (p) is formed, and a B register is set so as to show a frame top. A first clause (p) is developed to a machine instruction column. The clause has four permanent variables, and consequently, the formation of the environment frame is necessary. In an allocate instruction 6, is helded for an operand and the whole size of the environment frame including four words of a permanent variable cell part is designated. Here, into the stack area, a pointer to a continuous environment frame and a code address corresponding to the goal to be executed after the execution of said clause is normally completed are stored, and under it, the value cells corresponding to variables A, B, C and D are allocated.