Embedded systems generally have a small amount of memory and slow CPUs. Therefore it is desirable to increase the speed of JavaScript virtual machines (VMs) without increasing memory footprint. In this research, we introduce superinstructions, combinations of constant load instructions and arithmetic, logical, and relational (ALR) instructions to increase execution speed. Introducing superinstructions increases the size of a VM. Thus, we designed superinstructions so that they would share their implementation code with the ALR instructions, from which they are made. Furthermore, we simplified their type-based dispatching code through specialization to the datatypes of their constant operands. We developed a VM generator that creates VMs that have superinstructions in accordance with this approach and a compiler that compiles JavaScript programs using them.

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