diff options
Diffstat (limited to 'lib/compiler')
-rw-r--r-- | lib/compiler/src/beam_a.erl | 3 | ||||
-rw-r--r-- | lib/compiler/src/beam_block.erl | 10 | ||||
-rw-r--r-- | lib/compiler/src/beam_record.erl | 2 | ||||
-rw-r--r-- | lib/compiler/src/beam_type.erl | 13 | ||||
-rw-r--r-- | lib/compiler/src/beam_utils.erl | 54 | ||||
-rw-r--r-- | lib/compiler/src/sys_core_fold.erl | 159 | ||||
-rw-r--r-- | lib/compiler/test/core_fold_SUITE.erl | 38 |
7 files changed, 178 insertions, 101 deletions
diff --git a/lib/compiler/src/beam_a.erl b/lib/compiler/src/beam_a.erl index 6f09dc4be4..7df2edd714 100644 --- a/lib/compiler/src/beam_a.erl +++ b/lib/compiler/src/beam_a.erl @@ -58,7 +58,8 @@ rename_instrs([{call_only,A,F}|Is]) -> rename_instrs([{call_ext_only,A,F}|Is]) -> [{call_ext,A,F},return|rename_instrs(Is)]; rename_instrs([{'%live',_}|Is]) -> - %% When compiling from old .S files. + %% Ignore old type of live annotation. Only happens when compiling + %% from very old .S files. rename_instrs(Is); rename_instrs([I|Is]) -> [rename_instr(I)|rename_instrs(Is)]; diff --git a/lib/compiler/src/beam_block.erl b/lib/compiler/src/beam_block.erl index 488485c17a..39ae8d5347 100644 --- a/lib/compiler/src/beam_block.erl +++ b/lib/compiler/src/beam_block.erl @@ -47,7 +47,7 @@ function({function,Name,Arity,CLabel,Is0}, Blockify) -> Is4 = move_allocates(Is3), Is5 = beam_utils:live_opt(Is4), Is6 = opt_blocks(Is5), - Is7 = beam_utils:delete_live_annos(Is6), + Is7 = beam_utils:delete_annos(Is6), Is = opt_allocs(Is7), %% Done. @@ -143,7 +143,7 @@ embed_lines([], Acc) -> Acc. opt_blocks([{block,Bl0}|Is]) -> %% The live annotation at the beginning is not useful. - [{'%live',_,_}|Bl] = Bl0, + [{'%anno',_}|Bl] = Bl0, [{block,opt_block(Bl)}|opt_blocks(Is)]; opt_blocks([I|Is]) -> [I|opt_blocks(Is)]; @@ -202,7 +202,7 @@ move_allocates([I|Is]) -> [I|move_allocates(Is)]; move_allocates([]) -> []. -move_allocates_1([{'%def',_}|Is], Acc) -> +move_allocates_1([{'%anno',_}|Is], Acc) -> move_allocates_1(Is, Acc); move_allocates_1([I|Is], [{set,[],[],{alloc,Live0,Info}}|Acc]=Acc0) -> case alloc_may_pass(I) of @@ -253,7 +253,7 @@ opt([{set,[D1],[{integer,Idx1},Reg],{bif,element,{f,L}}}=I1, opt([{set,Ds0,Ss,Op}|Is0]) -> {Ds,Is} = opt_moves(Ds0, Is0), [{set,Ds,Ss,Op}|opt(Is)]; -opt([{'%live',_,_}=I|Is]) -> +opt([{'%anno',_}=I|Is]) -> [I|opt(Is)]; opt([]) -> []. @@ -535,7 +535,7 @@ x_live([], Regs) -> Regs. %% Given a reversed instruction stream, determine the %% the registers that are defined. -defined_regs([{'%def',Def}|_], Regs) -> +defined_regs([{'%anno',{def,Def}}|_], Regs) -> Def bor Regs; defined_regs([{set,Ds,_,{alloc,Live,_}}|_], Regs) -> x_live(Ds, Regs bor ((1 bsl Live) - 1)); diff --git a/lib/compiler/src/beam_record.erl b/lib/compiler/src/beam_record.erl index db1053e48c..58a6de6775 100644 --- a/lib/compiler/src/beam_record.erl +++ b/lib/compiler/src/beam_record.erl @@ -71,7 +71,7 @@ rewrite([{test,test_arity,Fail,[Src,N]}=TA, I = {test,is_tagged_tuple,Fail,[Src,N,Atom]}, rewrite(Is, Idx, Def, [I|Acc]) end; -rewrite([{block,[{'%def',Def}|Bl]}|Is], Idx, _Def, Acc) -> +rewrite([{block,[{'%anno',{def,Def}}|Bl]}|Is], Idx, _Def, Acc) -> rewrite(Is, Idx, Def, [{block,Bl}|Acc]); rewrite([{label,L}=I|Is], Idx0, Def, Acc) -> Idx = beam_utils:index_label(L, Acc, Idx0), diff --git a/lib/compiler/src/beam_type.erl b/lib/compiler/src/beam_type.erl index 14fe22fd27..3b6bf49961 100644 --- a/lib/compiler/src/beam_type.erl +++ b/lib/compiler/src/beam_type.erl @@ -40,7 +40,7 @@ function({function,Name,Arity,CLabel,Asm0}) -> Asm1 = beam_utils:live_opt(Asm0), Asm2 = opt(Asm1, [], tdb_new()), Asm3 = beam_utils:live_opt(Asm2), - Asm = beam_utils:delete_live_annos(Asm3), + Asm = beam_utils:delete_annos(Asm3), {function,Name,Arity,CLabel,Asm} catch Class:Error:Stack -> @@ -300,7 +300,7 @@ clearerror([], OrigIs) -> [{set,[],[],fclearerror}|OrigIs]. %% Combine two blocks and eliminate any move instructions that assign %% to registers that are killed later in the block. %% -merge_blocks(B1, [{'%live',_,_}|B2]) -> +merge_blocks(B1, [{'%anno',_}|B2]) -> merge_blocks_1(B1++[{set,[],[],stop_here}|B2]). merge_blocks_1([{set,[],_,stop_here}|Is]) -> Is; @@ -355,7 +355,7 @@ flt_need_heap_2({set,_,_,{alloc,_,_}}, H, Fl) -> {flt_alloc(H, Fl),0,0}; flt_need_heap_2({set,_,_,{set_tuple_element,_}}, H, Fl) -> {flt_alloc(H, Fl),0,0}; -flt_need_heap_2({'%live',_,_}, H, Fl) -> +flt_need_heap_2({'%anno',_}, H, Fl) -> {flt_alloc(H, Fl),0,0}; %% All other instructions are "neutral". We just pass them. flt_need_heap_2(_, H, Fl) -> @@ -382,7 +382,7 @@ build_alloc(Words, Floats) -> {alloc,[{words,Words},{floats,Floats}]}. %% is not continous at an allocation function (e.g. if {x,0} and {x,2} %% are live, but not {x,1}). -flt_liveness([{'%live',_Live,Regs}=LiveInstr|Is]) -> +flt_liveness([{'%anno',{used,Regs}}=LiveInstr|Is]) -> flt_liveness_1(Is, Regs, [LiveInstr]). flt_liveness_1([{set,Ds,Ss,{alloc,Live0,Alloc}}|Is], Regs0, Acc) -> @@ -394,7 +394,7 @@ flt_liveness_1([{set,Ds,Ss,{alloc,Live0,Alloc}}|Is], Regs0, Acc) -> flt_liveness_1([{set,Ds,_,_}=I|Is], Regs0, Acc) -> Regs = x_live(Ds, Regs0), flt_liveness_1(Is, Regs, [I|Acc]); -flt_liveness_1([{'%live',_,_}], _Regs, Acc) -> +flt_liveness_1([{'%anno',_}], _Regs, Acc) -> reverse(Acc). init_regs(Live) -> @@ -418,7 +418,8 @@ x_live([], Regs) -> Regs. %% Update the type database to account for executing an instruction. %% %% First the cases for instructions inside basic blocks. -update({'%live',_,_}, Ts) -> Ts; +update({'%anno',_}, Ts) -> + Ts; update({set,[D],[S],move}, Ts) -> tdb_copy(S, D, Ts); update({set,[D],[{integer,I},Reg],{bif,element,_}}, Ts0) -> diff --git a/lib/compiler/src/beam_utils.erl b/lib/compiler/src/beam_utils.erl index 2080a79986..901588ee3b 100644 --- a/lib/compiler/src/beam_utils.erl +++ b/lib/compiler/src/beam_utils.erl @@ -25,7 +25,7 @@ is_not_used/3,usage/3, empty_label_index/0,index_label/3,index_labels/1,replace_labels/4, code_at/2,bif_to_test/3,is_pure_test/1, - live_opt/1,delete_live_annos/1,combine_heap_needs/2, + live_opt/1,delete_annos/1,combine_heap_needs/2, anno_defs/1, split_even/1 ]). @@ -95,7 +95,7 @@ is_killed_block({x,X}, [{set,_,_,{alloc,Live,_}}|_]) -> X >= Live; is_killed_block(R, [{set,Ds,Ss,_Op}|Is]) -> not member(R, Ss) andalso (member(R, Ds) orelse is_killed_block(R, Is)); -is_killed_block(R, [{'%live',_,Regs}|Is]) -> +is_killed_block(R, [{'%anno',{used,Regs}}|Is]) -> case R of {x,X} when (Regs bsr X) band 1 =:= 0 -> true; _ -> is_killed_block(R, Is) @@ -270,7 +270,7 @@ is_pure_test({test,Op,_,Ops}) -> %% Go through the instruction sequence in reverse execution %% order, keep track of liveness and remove 'move' instructions %% whose destination is a register that will not be used. -%% Also insert {'%live',Live,Regs} annotations at the beginning +%% Also insert {used,Regs} annotations at the beginning %% and end of each block. -spec live_opt([instruction()]) -> [instruction()]. @@ -285,22 +285,22 @@ live_opt(Is0) -> Bef ++ [Fi|live_opt(reverse(Is), 0, D, [])]. -%% delete_live_annos([Instruction]) -> [Instruction]. -%% Delete all live annotations. +%% delete_annos([Instruction]) -> [Instruction]. +%% Delete all annotations. --spec delete_live_annos([instruction()]) -> [instruction()]. +-spec delete_annos([instruction()]) -> [instruction()]. -delete_live_annos([{block,Bl0}|Is]) -> - case delete_live_annos(Bl0) of - [] -> delete_live_annos(Is); - [_|_]=Bl -> [{block,Bl}|delete_live_annos(Is)] +delete_annos([{block,Bl0}|Is]) -> + case delete_annos(Bl0) of + [] -> delete_annos(Is); + [_|_]=Bl -> [{block,Bl}|delete_annos(Is)] end; -delete_live_annos([{'%live',_,_}|Is]) -> - delete_live_annos(Is); -delete_live_annos([I|Is]) -> - [I|delete_live_annos(Is)]; -delete_live_annos([]) -> []. - +delete_annos([{'%anno',_}|Is]) -> + delete_annos(Is); +delete_annos([I|Is]) -> + [I|delete_annos(Is)]; +delete_annos([]) -> []. + %% combine_heap_needs(HeapNeed1, HeapNeed2) -> HeapNeed %% Combine the heap need for two allocation instructions. @@ -316,7 +316,7 @@ combine_heap_needs(H1, H2) -> %% anno_defs(Instructions) -> Instructions' -%% Add {'%def',RegisterBitmap} annotations to the beginning of +%% Add {def,RegisterBitmap} annotations to the beginning of %% each block. Iff bit X is set in the the bitmap, it means %% that {x,X} is defined when the block is entered. @@ -668,7 +668,7 @@ check_liveness_ret(_, _, St) -> {killed,St}. %% alloc_used - Used only in an allocate instruction %% used - Reg is explicitly used by an instruction %% -%% '%live' annotations are not allowed. +%% Annotations are not allowed. %% %% (Unknown instructions will cause an exception.) @@ -865,9 +865,9 @@ live_opt([{test,bs_start_match2,Fail,Live,[Src,_],_}=I|Is], _, D, Acc) -> %% Other instructions. live_opt([{block,Bl0}|Is], Regs0, D, Acc) -> - Live0 = {'%live',live_regs(Regs0),Regs0}, + Live0 = make_anno({used,Regs0}), {Bl,Regs} = live_opt_block(reverse(Bl0), Regs0, D, [Live0]), - Live = {'%live',live_regs(Regs),Regs}, + Live = make_anno({used,Regs}), live_opt(Is, Regs, D, [{block,[Live|Bl]}|Acc]); live_opt([build_stacktrace=I|Is], _, D, Acc) -> live_opt(Is, live_call(1), D, [I|Acc]); @@ -1005,7 +1005,7 @@ live_opt_block([{set,Ds,Ss,Op0}|Is], Regs0, D, Acc) -> _ -> live_opt_block(Is, Regs, D, [I|Acc]) end; -live_opt_block([{'%live',_,_}|Is], Regs, D, Acc) -> +live_opt_block([{'%anno',_}|Is], Regs, D, Acc) -> live_opt_block(Is, Regs, D, Acc); live_opt_block([], Regs, _, Acc) -> {Acc,Regs}. @@ -1080,7 +1080,7 @@ defs([{bif,_,{f,Fail},_Src,Dst}=I|Is], Regs0, D) -> [I|defs(Is, Regs, update_regs(Fail, Regs0, D))]; defs([{block,Block0}|Is], Regs0, D0) -> {Block,Regs,D} = defs_list(Block0, Regs0, D0), - [{block,[{'%def',Regs0}|Block]}|defs(Is, Regs, D)]; + [{block,[make_anno({def,Regs0})|Block]}|defs(Is, Regs, D)]; defs([{bs_init,{f,L},_,_,_,Dst}=I|Is], Regs0, D) -> Regs = def_regs([Dst], Regs0), [I|defs(Is, Regs, update_regs(L, Regs, D))]; @@ -1270,3 +1270,13 @@ update_regs(L, Regs0, D) -> all_defined(Live, Regs) -> All = (1 bsl Live) - 1, Regs band All =:= All. + +%%% +%%% Utilities. +%%% + +%% make_anno(Anno) -> WrappedAnno. +%% Wrap an annotation term. + +make_anno(Anno) -> + {'%anno',Anno}. diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index e28d48acf5..46816fe24a 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -145,14 +145,9 @@ find_fixpoint(OptFun, Core0, Max) -> body(Body, Sub) -> body(Body, value, Sub). -body(#c_values{anno=A,es=Es0}, Ctxt, Sub) -> - Es1 = expr_list(Es0, Ctxt, Sub), - case Ctxt of - value -> - #c_values{anno=A,es=Es1}; - effect -> - make_effect_seq(Es1, Sub) - end; +body(#c_values{anno=A,es=Es0}, value, Sub) -> + Es1 = expr_list(Es0, value, Sub), + #c_values{anno=A,es=Es1}; body(E, Ctxt, Sub) -> ?ASSERT(verify_scope(E, Sub)), expr(E, Ctxt, Sub). @@ -313,9 +308,15 @@ expr(#c_seq{arg=Arg0,body=B0}=Seq0, Ctxt, Sub) -> false -> %% Arg cannot be "values" here - only a single value %% make sense here. - case is_safe_simple(Arg, Sub) of - true -> B1; - false -> Seq0#c_seq{arg=Arg,body=B1} + case {Ctxt,is_safe_simple(Arg, Sub)} of + {effect,true} -> B1; + {effect,false} -> + case is_safe_simple(B1, Sub) of + true -> Arg; + false -> Seq0#c_seq{arg=Arg,body=B1} + end; + {value,true} -> B1; + {value,false} -> Seq0#c_seq{arg=Arg,body=B1} end end; expr(#c_let{}=Let0, Ctxt, Sub) -> @@ -379,10 +380,7 @@ expr(#c_case{}=Case0, Ctxt, Sub) -> Case = Case1#c_case{arg=Arg2,clauses=Cs2}, warn_no_clause_match(Case1, Case), Expr = eval_case(Case, Sub), - case move_case_into_arg(Case, Sub) of - impossible -> Expr; - Other -> Other - end; + move_case_into_arg(Expr, Sub); Other -> expr(Other, Ctxt, Sub) end; @@ -2664,53 +2662,93 @@ opt_simple_let_1(#c_let{vars=Vs0,body=B0}=Let, Arg0, Ctxt, Sub0) -> %% Optimise let and add new substitutions. {Vs,Args,Sub1} = let_substs(Vs0, Arg0, Sub0), BodySub = update_let_types(Vs, Args, Sub1), + Sub = Sub1#sub{v=[],s=cerl_sets:new()}, B = body(B0, Ctxt, BodySub), Arg = core_lib:make_values(Args), - opt_simple_let_2(Let, Vs, Arg, B, B0, Ctxt, Sub1). + opt_simple_let_2(Let, Vs, Arg, B, B0, Sub). + + +%% opt_simple_let_2(Let0, Vs0, Arg0, Body, PrevBody, Ctxt, Sub) -> Core. +%% Do final simplifications of the let. +%% +%% Note that the substitutions and scope in Sub have been cleared +%% and should not be used. -opt_simple_let_2(Let0, Vs0, Arg0, Body, PrevBody, Ctxt, Sub) -> +opt_simple_let_2(Let0, Vs0, Arg0, Body, PrevBody, Sub) -> case {Vs0,Arg0,Body} of - {[#c_var{name=N1}],Arg1,#c_var{name=N2}} -> - case N1 =:= N2 of - true -> - %% let <Var> = Arg in <Var> ==> Arg - Arg1; - false -> - %% let <Var> = Arg in <OtherVar> ==> seq Arg OtherVar - Arg = maybe_suppress_warnings(Arg1, Vs0, PrevBody), - #c_seq{arg=Arg,body=Body} - end; + {[#c_var{name=V}],Arg1,#c_var{name=V}} -> + %% let <Var> = Arg in <Var> ==> Arg + Arg1; {[],#c_values{es=[]},_} -> %% No variables left. Body; - {Vs,Arg1,#c_literal{}} -> - Arg = maybe_suppress_warnings(Arg1, Vs, PrevBody), - case Ctxt of - effect -> - %% Throw away the literal body. - Arg; - value -> - %% Since the variable is not used in the body, we - %% can rewrite the let to a sequence. - %% let <Var> = Arg in Literal ==> seq Arg Literal - #c_seq{arg=Arg,body=Body} - end; - {Vs,Arg1,Body} -> - %% If none of the variables are used in the body, we can - %% rewrite the let to a sequence: - %% let <Var> = Arg in BodyWithoutVar ==> - %% seq Arg BodyWithoutVar - case is_any_var_used(Vs, Body) of - false -> - Arg = maybe_suppress_warnings(Arg1, Vs, PrevBody), - #c_seq{arg=Arg,body=Body}; - true -> - Let1 = Let0#c_let{vars=Vs,arg=Arg1,body=Body}, - opt_bool_case_in_let(Let1, Sub) + {[#c_var{name=V}=Var|Vars]=Vars0,Arg1,Body} -> + case core_lib:is_var_used(V, Body) of + false when Vars =:= [] -> + %% If the variable is not used in the body, we can + %% rewrite the let to a sequence: + %% let <Var> = Arg in BodyWithoutVar ==> + %% seq Arg BodyWithoutVar + Arg = maybe_suppress_warnings(Arg1, Var, PrevBody), + #c_seq{arg=Arg,body=Body}; + false -> + %% There are multiple values returned by the argument + %% and the first value is not used (this is a 'case' + %% with exported variables, but the return value is + %% ignored). We can remove the first variable and the + %% the first value returned from the 'let' argument. + Arg2 = remove_first_value(Arg1, Sub), + Let1 = Let0#c_let{vars=Vars,arg=Arg2,body=Body}, + post_opt_let(Let1, Sub); + true -> + Let1 = Let0#c_let{vars=Vars0,arg=Arg1,body=Body}, + post_opt_let(Let1, Sub) end end. -%% maybe_suppress_warnings(Arg, [#c_var{}], PreviousBody) -> Arg' +%% post_opt_let(Let, Sub) +%% Final optimizations of the let. +%% +%% Note that the substitutions and scope in Sub have been cleared +%% and should not be used. + +post_opt_let(Let, Sub) -> + opt_bool_case_in_let(Let, Sub). + + +%% remove_first_value(Core0, Sub) -> Core. +%% Core0 is an expression that returns at least two values. +%% Remove the first value returned from Core0. + +remove_first_value(#c_values{es=[V|Vs]}, Sub) -> + Values = core_lib:make_values(Vs), + case is_safe_simple(V, Sub) of + false -> + #c_seq{arg=V,body=Values}; + true -> + Values + end; +remove_first_value(#c_case{clauses=Cs0}=Core, Sub) -> + Cs = remove_first_value_cs(Cs0, Sub), + Core#c_case{clauses=Cs}; +remove_first_value(#c_receive{clauses=Cs0,action=Act0}=Core, Sub) -> + Cs = remove_first_value_cs(Cs0, Sub), + Act = remove_first_value(Act0, Sub), + Core#c_receive{clauses=Cs,action=Act}; +remove_first_value(#c_let{body=B}=Core, Sub) -> + Core#c_let{body=remove_first_value(B, Sub)}; +remove_first_value(#c_seq{body=B}=Core, Sub) -> + Core#c_seq{body=remove_first_value(B, Sub)}; +remove_first_value(#c_primop{}=Core, _Sub) -> + Core; +remove_first_value(#c_call{}=Core, _Sub) -> + Core. + +remove_first_value_cs(Cs, Sub) -> + [C#c_clause{body=remove_first_value(B, Sub)} || + #c_clause{body=B}=C <- Cs]. + +%% maybe_suppress_warnings(Arg, #c_var{}, PreviousBody) -> Arg' %% Try to suppress false warnings when a variable is not used. %% For instance, we don't expect a warning for useless building in: %% @@ -2721,12 +2759,12 @@ opt_simple_let_2(Let0, Vs0, Arg0, Body, PrevBody, Ctxt, Sub) -> %% referenced in the original unoptimized code. If they were, we will %% consider the warning false and suppress it. -maybe_suppress_warnings(Arg, Vs, PrevBody) -> +maybe_suppress_warnings(Arg, #c_var{name=V}, PrevBody) -> case should_suppress_warning(Arg) of true -> Arg; %Already suppressed. false -> - case is_any_var_used(Vs, PrevBody) of + case core_lib:is_var_used(V, PrevBody) of true -> suppress_warning([Arg]); false -> @@ -2815,7 +2853,7 @@ move_case_into_arg(#c_case{arg=#c_case{arg=OuterArg, Outer#c_case{arg=OuterArg, clauses=[OuterCa,OuterCb]}; false -> - impossible + Inner0 end; move_case_into_arg(#c_case{arg=#c_seq{arg=OuterArg,body=InnerArg}=Outer, clauses=InnerClauses}=Inner, _Sub) -> @@ -2831,15 +2869,8 @@ move_case_into_arg(#c_case{arg=#c_seq{arg=OuterArg,body=InnerArg}=Outer, %% Outer#c_seq{arg=OuterArg, body=Inner#c_case{arg=InnerArg,clauses=InnerClauses}}; -move_case_into_arg(_, _) -> - impossible. - -is_any_var_used([#c_var{name=V}|Vs], Expr) -> - case core_lib:is_var_used(V, Expr) of - false -> is_any_var_used(Vs, Expr); - true -> true - end; -is_any_var_used([], _) -> false. +move_case_into_arg(Expr, _) -> + Expr. %%% %%% Retrieving information about types. diff --git a/lib/compiler/test/core_fold_SUITE.erl b/lib/compiler/test/core_fold_SUITE.erl index 262967d03d..4fd1f84569 100644 --- a/lib/compiler/test/core_fold_SUITE.erl +++ b/lib/compiler/test/core_fold_SUITE.erl @@ -27,7 +27,7 @@ multiple_aliases/1,redundant_boolean_clauses/1, mixed_matching_clauses/1,unnecessary_building/1, no_no_file/1,configuration/1,supplies/1, - redundant_stack_frame/1]). + redundant_stack_frame/1,export_from_case/1]). -export([foo/0,foo/1,foo/2,foo/3]). @@ -47,7 +47,7 @@ groups() -> multiple_aliases,redundant_boolean_clauses, mixed_matching_clauses,unnecessary_building, no_no_file,configuration,supplies, - redundant_stack_frame]}]. + redundant_stack_frame,export_from_case]}]. init_per_suite(Config) -> @@ -551,4 +551,38 @@ do_redundant_stack_frame(Map) -> end, {X, Y}. +%% Cover some clauses in sys_core_fold:remove_first_value/2. + +-record(export_from_case, {val}). + +export_from_case(_Config) -> + a = export_from_case_1(true), + b = export_from_case_1(false), + + R = #export_from_case{val=0}, + {ok,R} = export_from_case_2(false, R), + {ok,#export_from_case{val=42}} = export_from_case_2(true, R), + + ok. + +export_from_case_1(Bool) -> + case Bool of + true -> + id(42), + Result = a; + false -> + Result = b + end, + id(Result). + +export_from_case_2(Bool, Rec) -> + case Bool of + false -> + Result = Rec; + true -> + Result = Rec#export_from_case{val=42} + end, + {ok,Result}. + + id(I) -> I. |