Abstract

ing from Machine Details In order to derive a verified compiler, Muller-Olm first defines the effect of target machine (in this case transputer) instructions by simple source language processes, consisting mainly of delays indicating time consumption (as taken from the reference manual [Inm88]), assignments to variables representing the machine state, and some assertions. As an example, let us look at the definition of the effect of "jump" instructions: E 0 (j) w \Delta 3 ; IP; A; B; C; OReg:= IP + OReg; ?; ?; ?; 0 (1) This refinement relationship expresses that one may assume at least (w) the following about the basic effect (E 0 ) of a jump instruction (whose mnemonic is j): It takes up to 3 clock cycles, adds the contents of the operand register to the instruction pointer, makes the registers A, B, and C undefined, and clears the operand register. After this machine level has been defined, abstractions are introduced that correspond to increasingly abstract assembler languages. Th...

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