http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50346
--- Comment #4 from Ryan Johnson <scovich at gmail dot com> 2011-10-12 12:40:25 UTC --- (In reply to comment #3) > Well, it's a tree optimization issue. It's simple - the local aggregate f > escapes the function via the member function call to baz: > > <bb 5>: > foo::baz (&f); > > and as our points-to analysis is not flow-sensitive for memory/calls this > causes f to be clobbered by the call to bar Is flow-sensitive analysis within single functions prohibitively expensive? All the papers I can find talk about whole-program analysis, where it's very expensive in both time and space; the best I could find (CGO'11 best paper) gets it down to 20-30ms and 2-3MB per kLoC for up to ~300kLoC. > > as neither the bodies of baz nor bar are visible there is nothing we can do Would knowing the body of bar() help if the latter cannot be inlined?
