With the growing complexity of computer software and the growing reliance on software systems in everyday life and business, there is an increasing need for a high performance in the execution of the software. Performance of software, such as program simulators and emulators, is often crucial since these programs are meant to simulate a system or, like an emulator, to mimic the behavior of a specific system embedded in a larger program complex. The execution of software programs depends on the operation of compilers and interpreters that translates or interprets instruction sets to machine executable code. To achieve high performance of an interactive simulator in cases when instruction sets are not easily decoded, the best practice is to translate the instruction into an internal format, which in this text is called an intermediate format. The intermediate format code is faster to decode and execute for a software-implemented interpreter and can be used directly if the instruction is decoded and executed again.
To achieve high performance, prior art software interpreters usually limit parameter space to an instruction, for example by mapping an instruction to different service routines depending on the parameters given to the instruction. For example, the sparc instruction ‘add’ may be mapped to two different service routines, one that adds two registers and one that adds a register with a constant. Therefore, the number of service routines will typically be higher than the number of instructions in the simulated instruction set. When the number of service routines grow to a large number, certain compiler optimizations with a high time complexity will make compilation times unacceptable or will fail completely.
USPTO Backgrounds
USPTO Backgrounds