Automatic generation of microarchitecture simulators

We describe the UPFAST system that automatically generates a cycle level simulator, an assembler and a disassembler from a microarchitecture specification written in a domain specific language called the Architecture Description Language (ADL). Using the UPFAST system, it is easy to retarget a simulator for an existing architecture to a modified architecture since one has to simply modify the input specification and the new simulator is generated automatically. UPFAST also allows porting of simulators to different platforms with minimal effort. We have been able to develop three simulators ranging from simple pipelined processors to complicated out-of-order issue processors over a short period of three months. While the specifications of the architectures varied from 5000 to 6000 lines of ADL code, the sizes of automatically generated software varied from 20000 to 300000 lines of C++ code. The automatically generated simulators are less than 2 times slower than hand coded simulators for similar architectures