diff options
| -rw-r--r-- | lib/compiler/src/beam_jump.erl | 43 |
1 files changed, 24 insertions, 19 deletions
diff --git a/lib/compiler/src/beam_jump.erl b/lib/compiler/src/beam_jump.erl index 8b0e3e32f8..6f50bfdb9c 100644 --- a/lib/compiler/src/beam_jump.erl +++ b/lib/compiler/src/beam_jump.erl @@ -182,18 +182,20 @@ eliminate_moves(Is) -> eliminate_moves([{select,select_val,Reg,_,List}=I|Is], D0, Acc) -> D = update_value_dict(List, Reg, D0), eliminate_moves(Is, D, [I|Acc]); -eliminate_moves([{label,Lbl},{block,[{set,[Dst],[Lit],move}|BlkIs]}=Blk0|Is], - D, Acc0) -> +eliminate_moves([{test,is_eq_exact,_,[Reg,Val]}=I, + {block,BlkIs0}|Is], D0, Acc) -> + D = update_unsafe_labels(I, D0), + RegVal = {Reg,Val}, + BlkIs = eliminate_moves_blk(BlkIs0, RegVal), + eliminate_moves([{block,BlkIs}|Is], D, [I|Acc]); +eliminate_moves([{label,Lbl},{block,BlkIs0}=Blk|Is], D, Acc0) -> Acc = [{label,Lbl}|Acc0], - case already_has_value(Lit, Lbl, Dst, D) andalso - no_fallthrough(Acc0) of - true -> - %% Remove redundant 'move' instruction. - Blk = {block,BlkIs}, - eliminate_moves([Blk|Is], D, Acc); - false -> - %% Keep 'move' instruction. - eliminate_moves([Blk0|Is], D, Acc) + case {no_fallthrough(Acc0),D} of + {true,#{Lbl:={_,_}=RegVal}} -> + BlkIs = eliminate_moves_blk(BlkIs0, RegVal), + eliminate_moves([{block,BlkIs}|Is], D, Acc); + {_,_} -> + eliminate_moves([Blk|Is], D, Acc) end; eliminate_moves([{block,[]}|Is], D, Acc) -> %% Empty blocks can prevent further jump optimizations. @@ -203,17 +205,20 @@ eliminate_moves([I|Is], D0, Acc) -> eliminate_moves(Is, D, [I|Acc]); eliminate_moves([], _, Acc) -> reverse(Acc). +eliminate_moves_blk([{set,[Dst],[_],move}|_]=Is, {_,Dst}) -> + Is; +eliminate_moves_blk([{set,[Dst],[Lit],move}|Is], {Dst,Lit}) -> + %% Remove redundant 'move' instruction. + Is; +eliminate_moves_blk([{set,[Dst],[_],move}|_]=Is, {Dst,_}) -> + Is; +eliminate_moves_blk([{set,[_],[_],move}=I|Is], {_,_}=RegVal) -> + [I|eliminate_moves_blk(Is, RegVal)]; +eliminate_moves_blk(Is, _) -> Is. + no_fallthrough([I|_]) -> is_unreachable_after(I). -already_has_value(Lit, Lbl, Reg, D) -> - case D of - #{Lbl:={Reg,Lit}} -> - true; - #{} -> - false - end. - update_value_dict([Lit,{f,Lbl}|T], Reg, D0) -> D = case D0 of #{Lbl:=unsafe} -> D0; |