About the most time consuming compiler process

[Gengyulei (Gengyl)]

Hi, 
   I want to find the most consuming compiler process, the time report is as following:

  	                usr	    sys      wall
 TOTAL           	759.59	92.92	1396.19
 phase generate	    498.34	31.1     870.94
 template instantiation	90.49	13.9  	469.89
 phase parsing	    245.56	59.55	465.9
 phase cgraph	    418.14	21.59	443.51

why the phase parsing is spent so much time, it only do the parsing job. the proportion should be small. 

How to explain it?

Thank you.

Best Regards.

Geng.