| Message ID | ZfKxA1c19VV3lb4V@tucnak |
|---|---|
| State | New |
| Headers | show |
| Series | gimple-iterator: Some gsi_safe_insert_*before fixes | expand |
On Thu, 14 Mar 2024, Jakub Jelinek wrote: > Hi! > > When trying to use the gsi_safe_insert*before APIs in bitint lowering, > I've discovered 3 issues and the following patch addresses those: > > 1) both split_block and split_edge update CDI_DOMINATORS if they are > available, but because edge_before_returns_twice_call first splits > and then adds an extra EDGE_ABNORMAL edge and then removes another > one, the immediate dominators of both the new bb and the bb with > returns_twice call need to change > 2) the new EDGE_ABNORMAL edge had uninitialized probability; this patch > copies the probability from the edge that is going to be removed > and similarly copies other flags (EDGE_EXECUTABLE, EDGE_DFS_BACK, > EDGE_IRREDUCIBLE_LOOP etc.) > 3) if edge_before_returns_twice_call splits a block, then the bb with > returns_twice call changes, so the gimple_stmt_iterator for it is > no longer accurate, it points to the right statement, but gsi_bb > and gsi_seq are no longer correct; the patch updates it > > Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? OK > 2024-03-14 Jakub Jelinek <jakub@redhat.com> > > * gimple-iterator.cc (edge_before_returns_twice_call): Copy all > flags and probability from ad_edge to e edge. If CDI_DOMINATORS > are computed, recompute immediate dominator of other_edge->src > and other_edge->dest. > (gsi_safe_insert_before, gsi_safe_insert_seq_before): Update *iter > for the returns_twice call case to the gsi_for_stmt (stmt) to deal > with update it for bb splitting. > > --- gcc/gimple-iterator.cc.jj 2024-03-13 13:03:08.073117732 +0100 > +++ gcc/gimple-iterator.cc 2024-03-13 15:16:45.294317700 +0100 > @@ -997,7 +997,18 @@ edge_before_returns_twice_call (basic_bl > add_phi_arg (new_phi, gimple_phi_arg_def_from_edge (phi, ad_edge), > e, gimple_phi_arg_location_from_edge (phi, ad_edge)); > } > + e->flags = ad_edge->flags; > + e->probability = ad_edge->probability; > remove_edge (ad_edge); > + if (dom_info_available_p (CDI_DOMINATORS)) > + { > + set_immediate_dominator (CDI_DOMINATORS, other_edge->src, > + recompute_dominator (CDI_DOMINATORS, > + other_edge->src)); > + set_immediate_dominator (CDI_DOMINATORS, other_edge->dest, > + recompute_dominator (CDI_DOMINATORS, > + other_edge->dest)); > + } > } > return other_edge; > } > @@ -1045,6 +1056,7 @@ gsi_safe_insert_before (gimple_stmt_iter > if (new_bb) > e = single_succ_edge (new_bb); > adjust_before_returns_twice_call (e, g); > + *iter = gsi_for_stmt (stmt); > } > else > gsi_insert_before (iter, g, GSI_SAME_STMT); > @@ -1075,6 +1087,7 @@ gsi_safe_insert_seq_before (gimple_stmt_ > if (g == l) > break; > } > + *iter = gsi_for_stmt (stmt); > } > else > gsi_insert_seq_before (iter, seq, GSI_SAME_STMT); > > Jakub > >
--- gcc/gimple-iterator.cc.jj 2024-03-13 13:03:08.073117732 +0100 +++ gcc/gimple-iterator.cc 2024-03-13 15:16:45.294317700 +0100 @@ -997,7 +997,18 @@ edge_before_returns_twice_call (basic_bl add_phi_arg (new_phi, gimple_phi_arg_def_from_edge (phi, ad_edge), e, gimple_phi_arg_location_from_edge (phi, ad_edge)); } + e->flags = ad_edge->flags; + e->probability = ad_edge->probability; remove_edge (ad_edge); + if (dom_info_available_p (CDI_DOMINATORS)) + { + set_immediate_dominator (CDI_DOMINATORS, other_edge->src, + recompute_dominator (CDI_DOMINATORS, + other_edge->src)); + set_immediate_dominator (CDI_DOMINATORS, other_edge->dest, + recompute_dominator (CDI_DOMINATORS, + other_edge->dest)); + } } return other_edge; } @@ -1045,6 +1056,7 @@ gsi_safe_insert_before (gimple_stmt_iter if (new_bb) e = single_succ_edge (new_bb); adjust_before_returns_twice_call (e, g); + *iter = gsi_for_stmt (stmt); } else gsi_insert_before (iter, g, GSI_SAME_STMT); @@ -1075,6 +1087,7 @@ gsi_safe_insert_seq_before (gimple_stmt_ if (g == l) break; } + *iter = gsi_for_stmt (stmt); } else gsi_insert_seq_before (iter, seq, GSI_SAME_STMT);