1. An analysis system for reducing a flow control divergence in a graphics processing unit (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 and a number of at least one cycle, and to calculate at least a direction ratio of a counting program code, and to send an information to said 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, wherein said profiler unit receiving a number of branch, a number of cycle, and a direction ratio transmitted by said hardware performance profiling support unit, said profiler unit determines whether said counting program code has 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, said optimization unit comprising an optimization decision unit, said optimization decision unit determines which transform pattern is used for transforming said sub-flow control structure in accordance with a branch ratio and said number of said specific branch instruction; wherein, when said profiler unit determines whether said counting program code has said optimized sub-flow control structure and said specific branch instruction or not, said profiler unit calculates said branch ratio of said each branch and a number of a specific branch instruction.