One or more architected registers are restored from a snapshot previously taken of the one or more architected registers. The snapshot indicates one or more physical registers previously assigned to the one or more architected registers. The restoring replaces the one or more physical registers currently assigned to the one or more architected registers with the one or more physical registers previously assigned to the one or more architected registers as indicated by the snapshot. A determination is made as to the validity of the one or more architected registers restored using the snapshot. The determining validity includes checking memory locations associated with the one or more architected registers to determine whether contents of the one or more architected registers have changed since the snapshot was taken. If the contents of the one or more architected registers have not changed, the one or more architected registers are valid.