Method and system for instruction-set architecture simulation using just in time compilation

A computer implemented method of simulating the execution of a set of instructions comprising:

• a) accessing a first instruction to be simulated;
• b) determining if compiled data relating to said first instruction is present in a memory stored table;
• c) if said compiled data relating to said first instruction is present in said memory stored table, providing said compiled data to a simulator for execution thereof by a computer system;
• and
• d) if said compiled data relating to said first instruction is not present in said memory stored table, compiling said first instruction to produce a compiled result and providing said compiled result to said simulator for execution thereof by a computer system.

A computer implemented method of simulating the execution of a set of instructions comprising:

• a) when an instruction of a program simulation is to be executed by a simulator at run-time, determining if information to simulate said instruction is stored in a memory table;
• b) if said information is not therein, determining said information to be used to simulate said instruction;
• c) determining if a location in said memory table to which said information is to be written is protected;
• d) if said location is not protected, storing said information in said memory table location and returning said information to said simulator;
• and
• e) if said location is protected, returning said information to said simulator without storing said information in said memory table.

A computer system for simulating a program, comprising:

• a cache table for storing information for specifying operations to simulate an instruction-set architecture;
• an instruction compiler for decoding instructions to be simulated, determining said information, and storing said information in said cache table;
• and
• a program simulator for using said information to simulate said instruction-set architecture.

A computer readable medium having stored therein instructions which when executed on a general purpose processor implement a method of simulating a processor, said method comprising:

• a) determining if compiled data used in simulating an instruction is stored in a memory table of compiled instructions, in response to a request for said compiled data;
• b) if said compiled data is not is said memory table:
• b1) decoding said instruction;
• b2) determining said compiled data;
• b3) storing said compiled data in said memory table;
• and
• c) returning said compiled data to a simulator for executing a program simulation.