A method for secure, simple, and fast speculative execution crossing trust domains

A method of verifying the safety of a speculative instruction, comprising:

• a processor speculatively arriving at execution of an instruction, the instruction associated with i) a source representing a range of source virtual or physical memory addresses holding the instruction to be executed, and ii) a destination representing a ranges of destination virtual or physical memory addresses holding data of which one or more addresses are to be loaded onto a register with execution of the instruction in the source, the source and destination representing a pair of information (PAIR);
• during instruction execution checking the PAIR against one or more memory tables associated with previous combinations of the PAIR that have successfully cleared as non-speculative,
• maintaining the one or more tables in a safe state,
• if the speculation of the source instruction clears the checking the PAIR step as safe, then allowing the execution of the speculative instruction to proceed, and
• if the speculation of the source instruction does not clear the checking as safe, then execution of the speculative instruction is delayed until such execution becomes non-speculative.