diff options
Diffstat (limited to 'lib/compiler/src/beam_a.erl')
| -rw-r--r-- | lib/compiler/src/beam_a.erl | 29 |
1 files changed, 27 insertions, 2 deletions
diff --git a/lib/compiler/src/beam_a.erl b/lib/compiler/src/beam_a.erl index 6fd4ace540..dd2537a699 100644 --- a/lib/compiler/src/beam_a.erl +++ b/lib/compiler/src/beam_a.erl @@ -39,14 +39,29 @@ function({function,Name,Arity,CLabel,Is0}) -> %% Remove unusued labels for cleanliness and to help %% optimization passes and HiPE. - Is = beam_jump:remove_unused_labels(Is1), - {function,Name,Arity,CLabel,Is} + Is2 = beam_jump:remove_unused_labels(Is1), + + %% Some optimization passes can't handle consecutive labels. + %% Coalesce multiple consecutive labels. + Is = coalesce_consecutive_labels(Is2, [], []), + + {function,Name,Arity,CLabel,Is} catch Class:Error:Stack -> io:fwrite("Function: ~w/~w\n", [Name,Arity]), erlang:raise(Class, Error, Stack) end. +rename_instrs([{test,is_eq_exact,_,[Dst,Src]}=Test, + {move,Src,Dst}|Is]) -> + %% The move instruction is not needed. + rename_instrs([Test|Is]); +rename_instrs([{test,is_eq_exact,_,[Same,Same]}|Is]) -> + %% Same literal or same register. Will always succeed. + rename_instrs(Is); +rename_instrs([{loop_rec,{f,Fail},{x,0}},{loop_rec_end,_},{label,Fail}|Is]) -> + %% This instruction sequence does nothing. + rename_instrs(Is); rename_instrs([{apply_last,A,N}|Is]) -> [{apply,A},{deallocate,N},return|rename_instrs(Is)]; rename_instrs([{call_last,A,F,N}|Is]) -> @@ -113,6 +128,8 @@ rename_instr({put_map_exact,Fail,S,D,R,L}) -> {put_map,Fail,exact,S,D,R,L}; rename_instr({test,has_map_fields,Fail,Src,{list,List}}) -> {test,has_map_fields,Fail,[Src|List]}; +rename_instr({test,is_nil,Fail,[Src]}) -> + {test,is_eq_exact,Fail,[Src,nil]}; rename_instr({select_val=I,Reg,Fail,{list,List}}) -> {select,I,Reg,Fail,List}; rename_instr({select_tuple_arity=I,Reg,Fail,{list,List}}) -> @@ -120,3 +137,11 @@ rename_instr({select_tuple_arity=I,Reg,Fail,{list,List}}) -> rename_instr(send) -> {call_ext,2,send}; rename_instr(I) -> I. + +coalesce_consecutive_labels([{label,L}=Lbl,{label,Alias}|Is], Replace, Acc) -> + coalesce_consecutive_labels([Lbl|Is], [{Alias,L}|Replace], Acc); +coalesce_consecutive_labels([I|Is], Replace, Acc) -> + coalesce_consecutive_labels(Is, Replace, [I|Acc]); +coalesce_consecutive_labels([], Replace, Acc) -> + D = maps:from_list(Replace), + beam_utils:replace_labels(Acc, [], D, fun(L) -> L end). |