Re: optimization/9767 - question on inlining functions vs. member functions

Re: optimization/9767 - question on inlining functions vs. member functions

[Jason Merrill]

The following reply was made to PR optimization/9767; it has been noted by GNATS.

From: Jason Merrill <jason@redhat.com>
To: Benjamin Kosnik <bkoz@redhat.com>
Cc: rth@redhat.com, gcc-gnats@gcc.gnu.org
Subject: Re: optimization/9767 - question on inlining functions vs. member
 functions
Date: Fri, 28 Feb 2003 15:20:54 -0500

 OK, the problem is with the design of the inliner.  In many cases, whether
 or not a function gets inlined depends on whether or not it has already
 been expanded--and as a result, had inline expansion done on it.  _M_write
 has 14 statements before optimize_inline_calls, and 49 after, which makes
 it no longer a candidate for inlining.  In your explicit instantiation
 testcase, instantiating the whole class instantiates _M_write before write,
 so _M_write can't be inlined; if you just instantiate write, _M_write has
 not been expanded, so it can still be inlined.
 
 One fix would be to keep a copy of the original function trees for use in
 inlining.  Optimal inlining strategy is still a topic of debate...
 
 Jason