Description of Problem:

See attached source.

When compiling with -O2, a large virtual member function of a derived 
class that is defined as inlined in .cpp source, not header file, is not 
compiled, and an unresolved external reference is made instead.

Since the function is defined in the .cpp file (and is only called from 
within that same file), it won't get compiled elsewhere either. The end 
result is that the function is undefined and the program using the class 
cannot link.

How Reproducible:
[alane@wwweasel alane]$ rpm -q gcc
gcc-2.96-81
[alane@wwweasel alane]$ rpm -q gcc-c++
gcc-c++-2.96-81
[alane@wwweasel alane]$ g++ -O2 -c alzheimer.cpp
[alane@wwweasel alane]$ nm alzheimer.o
         U Oops_I_forgot_to_compile_this__9Mpegtoraw
00000000 ? __FRAME_BEGIN__
00000000 t gcc2_compiled.
00000000 T subbandsynthesis__9MpegtorawPfT1
[alane@wwweasel alane]$

Additional Information:

Removing the virtual function from either the parent class or the derived 
class (or making the function non-virtual) eliminates the error.

Compiling without -O2 also produces the correct result.

This code is from a package called avifile. I have stripped it down to 
the smallest bit that would still exhibit the problem. Although I have 
not tested it, it would seem likely that this problem does not present on 
gcc-2.95, as I believe that is what the package author is using.