Hi Andrew, > > I might need your help later as a loop optimizer expert. I just found > > yesterday that tree-ssa-loop-im.c:schedule_sm is using stmt_ann before > > a statement proper is linked to a basic block. Specifically, it > > creates a statement, attaches a stmt_ann, and puts it on edge. We > > probably have to one of the following. > > > > 1) delay the creation of stmt_ann until after a statement is linked, > > > > 2) create a stmt_ann just like we do now, and then copy its contents > > to stmt_ann embedded in tree_statement_list_node, or > > > > 3) create a tree_statement_list_node in schedule_sm, which contains > > stmt_ann, and link it to a basic block. (This option would require > > bigger changes as we are currently supposed to put a statement in > > PENDING_STMT, not a tree_statement_list_node. Plus, bsi_insert_* > > and tsi_link_* stuff all expect a statement.) > > > > Right now I am just instrumenting stmt_ann to see where people are > > using stmt_ann while a statement is not linked to a basic block. > > These are in fact issues with immediate_uses too. I fixed the ones I > found that were causing problems, but the stmt annotation and operands > should *NOT* be created until a stmt is actually linked the program via > a bsi_ routine or some such thing.
Ah, so we should go with 1) above wherever possible. Once these uses of stmt_ann are fixed, we can arrange things so that we *CANNOT POSSIBLY* create stmt_ann and operands (except maybe in create_ssa_artficial_load). Then the actual work of embedding stmt_ann into tree_statement_list_node shouldn't be difficult. Kazu Hirata
