diff options
Diffstat (limited to 'lib/compiler/src/v3_codegen.erl')
-rw-r--r-- | lib/compiler/src/v3_codegen.erl | 83 |
1 files changed, 42 insertions, 41 deletions
diff --git a/lib/compiler/src/v3_codegen.erl b/lib/compiler/src/v3_codegen.erl index 34c67b16ca..6f1912c616 100644 --- a/lib/compiler/src/v3_codegen.erl +++ b/lib/compiler/src/v3_codegen.erl @@ -827,21 +827,24 @@ select_extract_bin([{var,Hd},{var,Tl}], Size0, Unit, Type, Flags, Vf, {bs_save2,CtxReg,{Ctx,Tl}}],Int1} end, {Es,clear_dead(Aft, I, Vdb),St}; -select_extract_bin([{var,Hd}], Size0, Unit, binary, Flags, Vf, +select_extract_bin([{var,Hd}], Size, Unit, binary, Flags, Vf, I, Vdb, Bef, Ctx, Body, St) -> - SizeReg = get_bin_size_reg(Size0, Bef), + %% Match the last segment of a binary. We KNOW that the size + %% must be 'all'. + Size = {atom,all}, %Assertion. {Es,Aft} = case vdb_find(Hd, Vdb) of {_,_,Lhd} when Lhd =< I -> + %% The result will not be used. Furthermore, since we + %% we are at the end of the binary, the position will + %% not be used again; thus, it is safe to do a cheaper + %% test of the unit. CtxReg = fetch_var(Ctx, Bef), - {case SizeReg =:= {atom,all} andalso is_context_unused(Body) of - true when Unit =:= 1 -> + {case Unit of + 1 -> []; - true -> - [{test,bs_test_unit,{f,Vf},[CtxReg,Unit]}]; - false -> - [{test,bs_skip_bits2,{f,Vf}, - [CtxReg,SizeReg,Unit,{field_flags,Flags}]}] + _ -> + [{test,bs_test_unit,{f,Vf},[CtxReg,Unit]}] end,Bef}; {_,_,_} -> case is_context_unused(Body) of @@ -853,7 +856,7 @@ select_extract_bin([{var,Hd}], Size0, Unit, binary, Flags, Vf, Name = bs_get_binary2, Live = max_reg(Bef#sr.reg), {[{test,Name,{f,Vf},Live, - [CtxReg,SizeReg,Unit,{field_flags,Flags}],Rhd}], + [CtxReg,Size,Unit,{field_flags,Flags}],Rhd}], Int1}; true -> %% Since the matching context will not be used again, @@ -868,7 +871,7 @@ select_extract_bin([{var,Hd}], Size0, Unit, binary, Flags, Vf, Name = bs_get_binary2, Live = max_reg(Int1#sr.reg), {[{test,Name,{f,Vf},Live, - [CtxReg,SizeReg,Unit,{field_flags,Flags}],CtxReg}], + [CtxReg,Size,Unit,{field_flags,Flags}],CtxReg}], Int1} end end, @@ -1327,12 +1330,13 @@ bif_cg(Bif, As, [{var,V}], Le, Vdb, Bef, St0) -> %% that we save any variable that will be live after this BIF call. MayFail = not erl_bifs:is_safe(erlang, Bif, length(As)), - {Sis,Int0} = case St0#cg.in_catch andalso - St0#cg.bfail =:= 0 andalso - MayFail of - true -> adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb); - false -> {[],Bef} - end, + {Sis,Int0} = + case MayFail of + true -> + maybe_adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb, St0); + false -> + {[],Bef} + end, Int1 = clear_dead(Int0, Le#l.i, Vdb), Reg = put_reg(V, Int1#sr.reg), Int = Int1#sr{reg=Reg}, @@ -1363,11 +1367,7 @@ gc_bif_cg(Bif, As, [{var,V}], Le, Vdb, Bef, St0) -> %% Currently, we are somewhat pessimistic in %% that we save any variable that will be live after this BIF call. - {Sis,Int0} = - case St0#cg.in_catch andalso St0#cg.bfail =:= 0 of - true -> adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb); - false -> {[],Bef} - end, + {Sis,Int0} = maybe_adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb, St0), Int1 = clear_dead(Int0, Le#l.i, Vdb), Reg = put_reg(V, Int1#sr.reg), @@ -1512,8 +1512,7 @@ set_cg([{var,R}], {cons,Es}, Le, Vdb, Bef, St) -> Int1 = Int0#sr{reg=put_reg(R, Int0#sr.reg)}, Ret = fetch_reg(R, Int1#sr.reg), {[{put_list,S1,S2,Ret}], Int1, St}; -set_cg([{var,R}], {binary,Segs}, Le, Vdb, Bef, - #cg{in_catch=InCatch, bfail=Bfail}=St) -> +set_cg([{var,R}], {binary,Segs}, Le, Vdb, Bef, #cg{bfail=Bfail}=St) -> %% At run-time, binaries are constructed in three stages: %% 1) First the size of the binary is calculated. %% 2) Then the binary is allocated. @@ -1532,11 +1531,7 @@ set_cg([{var,R}], {binary,Segs}, Le, Vdb, Bef, %% First generate the code that constructs each field. Fail = {f,Bfail}, PutCode = cg_bin_put(Segs, Fail, Bef), - {Sis,Int1} = - case InCatch of - true -> adjust_stack(Int0, Le#l.i, Le#l.i+1, Vdb); - false -> {[],Int0} - end, + {Sis,Int1} = maybe_adjust_stack(Int0, Le#l.i, Le#l.i+1, Vdb, St), MaxRegs = max_reg(Bef#sr.reg), Aft = clear_dead(Int1, Le#l.i, Vdb), @@ -1545,14 +1540,11 @@ set_cg([{var,R}], {binary,Segs}, Le, Vdb, Bef, {Sis++Code,Aft,St}; % Map single variable key set_cg([{var,R}], {map,Op,Map,[{map_pair,{var,_}=K,V}]}, Le, Vdb, Bef, - #cg{in_catch=InCatch,bfail=Bfail}=St) -> + #cg{bfail=Bfail}=St) -> Fail = {f,Bfail}, - {Sis,Int0} = - case InCatch of - true -> adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb); - false -> {[],Bef} - end, + {Sis,Int0} = maybe_adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb, St), + SrcReg = cg_reg_arg(Map,Int0), Line = line(Le#l.a), @@ -1573,17 +1565,13 @@ set_cg([{var,R}], {map,Op,Map,[{map_pair,{var,_}=K,V}]}, Le, Vdb, Bef, % Map (possibly) multiple literal keys set_cg([{var,R}], {map,Op,Map,Es}, Le, Vdb, Bef, - #cg{in_catch=InCatch,bfail=Bfail}=St) -> + #cg{bfail=Bfail}=St) -> %% assert key literals [] = [Var||{map_pair,{var,_}=Var,_} <- Es], Fail = {f,Bfail}, - {Sis,Int0} = - case InCatch of - true -> adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb); - false -> {[],Bef} - end, + {Sis,Int0} = maybe_adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb, St), SrcReg = cg_reg_arg(Map,Int0), Line = line(Le#l.a), @@ -2038,6 +2026,19 @@ trim_free([R|Rs0]) -> end; trim_free([]) -> []. +%% maybe_adjust_stack(Bef, FirstBefore, LastFrom, Vdb, St) -> {[Ainstr],Aft}. +%% Adjust the stack, but only if the code is inside a catch and not +%% inside a guard. Use this funtion before instructions that may +%% cause an exception. + +maybe_adjust_stack(Bef, Fb, Lf, Vdb, St) -> + case St of + #cg{in_catch=true,bfail=0} -> + adjust_stack(Bef, Fb, Lf, Vdb); + #cg{} -> + {[],Bef} + end. + %% adjust_stack(Bef, FirstBefore, LastFrom, Vdb) -> {[Ainstr],Aft}. %% Do complete stack adjustment by compressing stack and adding %% variables to be saved. Try to optimise ordering on stack by |