What you say is in line with my understanding, however when I instrument the execute function of ipa-function-and-variable-visibility (local_function_and_variable_visibility()) I note that:
gcc -flto a.c b.c causes the pass to be called twice (presumably once per file). If I split the compilation into two stages, then in the link stage gcc -flto a.o b.o the pass is never called. Conversely, the gate of IPA-Points-to does seem to be called three times at link time (presumably once for each file and then once for all together). I cannot discover the cause of the different behaviours here. Diego Novillo-3 wrote: > > On Wed, Jul 13, 2011 at 10:22, AJM-2 <mcpherson...@gmail.com> wrote: > >> My question is whether LTO can be used in this way, to have a simple ipa >> pass called once at link time with access to the function bodies, and if >> so >> how is this achieved? Â cgraph_function_body_availability seems to only be >> half the story. > > Yes, it can. You seem to be describing what GCC calls "simple IPA > pass". These are passes that cannot run in partitioned LTO mode, as > they require the function bodies to operate. Look for passes like > pass_ipa_function_and_variable_visibility for an example of a simple > IPA pass. > > > Diego. > > -- View this message in context: http://old.nabble.com/IPA-and-LTO-tp32052838p32054720.html Sent from the gcc - Dev mailing list archive at Nabble.com.
