1. A method for executing a non-native code stream on a computing system, the method comprising: forming one or more blocks of emulated mode code for execution on a computing system, each of the one or more blocks including a preamble and a plurality of operators ordered for execution in a predetermined sequence, wherein for a specified block the preamble defines one or more conditions required for uninterrupted execution of the operators included in the specified block; assessing the one or more conditions associated with the specified block; and after assessing the one or more conditions, executing each of the operators included in the specified block without assessing any of the one or more conditions between execution of the operators within the specified block.