http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51727
--- Comment #25 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> 2012-10-15 14:14:12 UTC --- Just to provide some additional numbers on how important this patch is for practical development (and of course to +1 on backports).... for a 'typical code change' on a CP2K tree (add an unused local variable to a subroutine) the speedup due to avoided recompilation (on a 32 core server) can be obtained from the following compile timings (repeatable for various tries): 4.6(unpatched) real 1m45.064s 4.7(patched) real 0m14.958s I really think this is a pretty substantial bug fix of an existing feature.
