recently, I use the cedet-1.1 to parse some common OpenGL header files(gl.h gl.ext.h glew.h glut.h) where there is huge numbers(6000+) of functions and constant starting with "gl" or "GL_"), I use the parse result as the backend of auto-complete. when I typed "GL_", I need to wait the cedet to ouput the completion canditates for 20+ seconds and the GNU Emacs freezes.
I think there may be something different with the new version of cedet, and I tried it(version: cedet_snapshot-rev_8499.tar.gz) out last night. I use the Alex Ott's "minimial-cedet-config.el" from "https://gist.github.com/alexott/3930120" to config the cedet. another I did is add the header files(gl.h gl.ext.h glew.h glut.h) dir to the "system include dir". To test it. I just use the `show tag completions`(not as the back end of auto-complete) in the menu items, when I typed "GL_" the time used to wait it responsive is too much(10+ seconds), I mean it is not the first time to wait it complete the parse (it costs more time to complete in the first time). cedet is awesome except that it is not fast enough, I hope some one can make it faster.