1. A method, comprising: compiling source code having an inner loop body using a graphics processing unit (GPU) compiler; when more than one machine code instruction of compiled source code under-utilizes GPU instruction bandwidth limitations; peeling the first iteration of the inner loop body out of the loop; lowering the type of operands in the source code; and reducing instructions of arbitrary vector lengths into graphics processing unit (GPU) supported vector lengths in the peeled out inner loop body of a source code using vector strip mining to obtain optimized source code.