The present invention extends to methods, systems, and computer program products for reconstructing program control flow. Embodiments include implementing or morphing a control flow graph (“CFG”) into an arbitrary loop structure to reconstruct (preserve) control flow from original source code. Loop structures can be optimized and can adhere to target platform constraints. In some embodiments, C++ source code (a first higher level format) is translated into a CFG (a lower level format). The CFG is then translated into High Level Shader Language (“HLSL”) source code (a second different higher level format) for subsequent compilation into SLSL bytecode (that can then be executed at a Graphical Processing Unit (“GPU”)). The control flow from the C++ source code is preserved in the HLSL source code.