A method and apparatus are provided to control the order of execution of load and store operations. Also provided is a computer readable storage device encoded with data for adapting a manufacturing facility to create the apparatus. One embodiment of the method includes determining whether a first group, comprising at least one or more instructions, is to be selected from a scheduling queue of a processor for execution using either a first execution mode or a second execution mode. The method also includes, responsive to determining that the first group is to be selected for execution using the second execution mode, preventing selection of the first group until a second group, comprising at least one or more instructions, that entered the scheduling queue prior to the first group is selected for execution.