1. An analysis system for reducing a flow control divergence in a GPU, said GPU comprises a computing unit and a hardware performance profiling support unit. the computing unit is used to count a number of at least one branch, a number of at least one cycle, and to calculate at least one direction ratio of a counting program code, and to send an information to a hardware performance profiling support unit, said analysis system comprises: a compiling unit, said compiling unit loads said counting program code; a profiler unit, said profiler unit is connected to said compiling unit, said profiler unit receiving said number of branch, said number of cycle, and said direction ratio transmitted by said hardware performance profiling support unit, said profiler unit determining whether said counting program code having an optimized sub-flow control structure and an optimized specific branch instruction in accordance with said number of branch, said number of cycle, and said direction ratio; and an optimization unit, said optimization unit being connected to said profiler unit; wherein, when said profiler unit determines whether said counting program code having said optimized sub-flow control structure and said specific branch instruction or not, said profiler unit calculating said branch ratio of said each branch and a number of a specific branch instruction, an optimization unit determining to use a transform pattern to transform said sub-flow control structure in accordance with said branch ratio and said number of said specific branch instruction.