1. A method, in a data processing system having a processor, for performing data parallel function calls in code during runtime, comprising: executing, in the processor, a portion of code having a data parallel function call to a target portion of code, wherein the portion of code having the data parallel function call is calling code; determining, at runtime by the processor, whether the target portion of code is a data parallel portion of code or a scalar portion of code; determining, at runtime by the processor, whether the calling code is data parallel code or scalar code; and executing the target portion of code based on the determination of whether the target portion of code is a data parallel portion of code or a scalar portion of code, and the determination of whether the calling code is data parallel code or scalar code.