A computer binary translator translates at least a segment of a binary representation of a program from a first instruction set architecture to a second instruction set architecture. A sequence of side-effects in the translation differs from a sequence of side-effects in the original. The translation distinguishes memory loads that are believed to be directed to well-behaved memory from memory loads that are believed to be directed to non-well-behaved memory device(s). Instruction execution circuitry identifies a memory reference that has a side-effect that has been reordered by translation, the memory reference having been believed at translation time to be directed to well-behaved memory but at execution it is found that the reference cannot be guaranteed to be well-behaved. The instruction execution circuitry identifies whether the difference in side-effect order may have a material effect on the execution of the program. A roll-back program state is established, and execution of the original code resumes.