pre compiled headers

[harsha@vishvakannada.com]

 I am compiling a big poject using gcc
 I want to create pre compiled headers automatically
 Now all my headers are compiling each time for each cpp file
can you tell me how can i specify pre compiled header file
name and what is the command line argument to create
automatic pch files ?

Regards,

 harsha@vishvakannada.com
 Harsha Kodnad
 Tally Solutions Pvt. Ltd.
 Bangalore.
 India