In this paper, Pythagorean-hodograph (PH) quintic spline curves constructed by several connected PH curves with C2 continuity are used to designing the toolpath in machining operation. To generate the toolpath commands, the acceleration/ deceleration phase of motion and the middle regions of the toolpath are devised by time-dependent and constant velocity interpolation algorithms, respectively. In the aforementioned interpolation algorithm, the exponential functions are employed to modify the feedrate profile and subsequently using the Pattern Search algorithm (PSA), the proposed feedrate profile is optimized to maintain the maximum jerk within allowable physical limits. Finally, high speed CNC machining for two cases of open and closed C2 PH quintic spline curves along with the commonly used feed forward/feedback controller is simulated in Simulink-Matlab software and the contouring error is studied and analyzed.