An analysis of 8086 instruction set usage in MS DOS programs

1. Introduction An architectural evaluation must be based upon real programs in an actual operating environment. The ubiquitous IBM** personal computer running MS DOS@ represents an excellent test bed for architectural evaluation of Intel@ 8086 systems. There are many programs and tools available to evaluate the performance of IBM Personal Computers and compatibles; these evaluation tools are intended to relate the performance of one machine to another. Very little data is available on dynamic instruction traces in systems using an 8086. This paper reports on dynamic traces of 8086/88 programs obtained using software tracing tools (described below). The objective of this work is to analyze instruction usage and addressing modes used in actual software. The system used to obtain the dynamic instruction frequencies was a compatible running MS DOS* 3.1 with a Softpatch@ BIOS. To illustrate the RISC argument that only a few instruction types are sufficient, the 8086 results are compared with similar studies on the Motorola* 68ooO and the Digital Equipment VAX-1 l@'.