A method for analyzing data reordering operations in Single Issue Multiple Data source code and generating executable code therefrom is provided. Input is received. One or more data reordering operations in the input are identified and each data reordering operation in the input is abstracted into a corresponding virtual shuffle operation so that each virtual shuffle operation forms part of an expression tree. One or more virtual shuffle trees are collapsed by combining virtual shuffle operations within at least one of the one or more virtual shuffle trees to form one or more combined virtual shuffle operations, wherein each virtual shuffle tree is a subtree of the expression tree that only contains virtual shuffle operations. Then code is generated for the one or more combined virtual shuffle operations.