The trend toward high-level language instructions has led to the development of more efficient compilers to convert high-level language instructions to machine code. Primary measures of compiler efficiency are the compactness of its generated code and the shortness of its execution time.

During the development of more efficient compilers, analysis of instruction streams revealed that the greatest amount of time was spent executing simple instructions and performing load and store operations, while the more complex instructions were used less frequently. It was also learned that compilers produce code that is often a narrow subset of the processor instruction set architecture (ISA). A compiler works more efficiently with instructions that perform simple, well-defined operations and generate minimal side-effects. Compilers do not use complex instructions and features; the more complex, powerful instructions are either too difficult for the compiler to employ or those instructions do not precisely fit high-level language requirements.

Thus, a natural match exists between RISC architectures and efficient, optimizing compilers. This match makes it easier for compilers to generate the most effective sequences of machine instructions to accomplish tasks defined by the high-level language.