diff options
| -rw-r--r-- | lib/compiler/src/beam_block.erl | 19 | ||||
| -rw-r--r-- | lib/compiler/src/beam_dead.erl | 16 | ||||
| -rw-r--r-- | lib/compiler/src/cerl.erl | 3 | ||||
| -rw-r--r-- | lib/compiler/src/sys_core_fold.erl | 124 | ||||
| -rw-r--r-- | lib/compiler/test/andor_SUITE.erl | 12 |
5 files changed, 133 insertions, 41 deletions
diff --git a/lib/compiler/src/beam_block.erl b/lib/compiler/src/beam_block.erl index 92f09e400c..5216f39296 100644 --- a/lib/compiler/src/beam_block.erl +++ b/lib/compiler/src/beam_block.erl @@ -252,13 +252,6 @@ combine_alloc({_,Ns,Nh1,Init}, {_,nostack,Nh2,[]}) -> %% opt([Instruction]) -> [Instruction] %% Optimize the instruction stream inside a basic block. -opt([{set,[Dst],As,{bif,Bif,Fail}}=I1, - {set,[Dst],[Dst],{bif,'not',Fail}}=I2|Is]) -> - %% Get rid of the 'not' if the operation can be inverted. - case inverse_comp_op(Bif) of - none -> [I1,I2|opt(Is)]; - RevBif -> [{set,[Dst],As,{bif,RevBif,Fail}}|opt(Is)] - end; opt([{set,[X],[X],move}|Is]) -> opt(Is); opt([{set,_,_,{line,_}}=Line1, {set,[D1],[{integer,Idx1},Reg],{bif,element,{f,0}}}=I1, @@ -428,18 +421,6 @@ x_live([{x,N}|Rs], Regs) -> x_live(Rs, Regs bor (1 bsl N)); x_live([_|Rs], Regs) -> x_live(Rs, Regs); x_live([], Regs) -> Regs. -%% inverse_comp_op(Op) -> none|RevOp - -inverse_comp_op('=:=') -> '=/='; -inverse_comp_op('=/=') -> '=:='; -inverse_comp_op('==') -> '/='; -inverse_comp_op('/=') -> '=='; -inverse_comp_op('>') -> '=<'; -inverse_comp_op('<') -> '>='; -inverse_comp_op('>=') -> '<'; -inverse_comp_op('=<') -> '>'; -inverse_comp_op(_) -> none. - %%% %%% Evaluation of constant bit fields. %%% diff --git a/lib/compiler/src/beam_dead.erl b/lib/compiler/src/beam_dead.erl index 7cd07dc3be..7f28575a65 100644 --- a/lib/compiler/src/beam_dead.erl +++ b/lib/compiler/src/beam_dead.erl @@ -234,10 +234,8 @@ backward([{select,select_val,Reg,{f,Fail0},List0}|Is], D, Acc) -> Fail = shortcut_bs_test(Fail1, Is, D), Sel = {select,select_val,Reg,{f,Fail},List}, backward(Is, D, [Sel|Acc]); -backward([{jump,{f,To0}},{move,Src0,Reg}|Is], D, Acc) -> - To1 = shortcut_select_label(To0, Reg, Src0, D), - {To,Src} = shortcut_boolean_label(To1, Reg, Src0, D), - Move = {move,Src,Reg}, +backward([{jump,{f,To0}},{move,Src,Reg}=Move|Is], D, Acc) -> + To = shortcut_select_label(To0, Reg, Src, D), Jump = {jump,{f,To}}, case beam_utils:is_killed_at(Reg, To, D) of false -> backward([Move|Is], D, [Jump|Acc]); @@ -330,16 +328,6 @@ shortcut_label(To0, D) -> shortcut_select_label(To, Reg, Lit, D) -> shortcut_rel_op(To, is_ne_exact, [Reg,Lit], D). -shortcut_boolean_label(To0, Reg, {atom,Bool0}=Lit, D) when is_boolean(Bool0) -> - case beam_utils:code_at(To0, D) of - [{line,_},{bif,'not',_,[Reg],Reg},{jump,{f,To}}|_] -> - Bool = {atom,not Bool0}, - {shortcut_select_label(To, Reg, Bool, D),Bool}; - _ -> - {To0,Lit} - end; -shortcut_boolean_label(To, _, Bool, _) -> {To,Bool}. - %% Replace a comparison operator with a test instruction and a jump. %% For example, if we have this code: %% diff --git a/lib/compiler/src/cerl.erl b/lib/compiler/src/cerl.erl index 3d4b9ee0c6..8367a1e19e 100644 --- a/lib/compiler/src/cerl.erl +++ b/lib/compiler/src/cerl.erl @@ -138,7 +138,8 @@ ]). -export_type([c_binary/0, c_bitstr/0, c_call/0, c_clause/0, c_cons/0, c_fun/0, - c_literal/0, c_map/0, c_map_pair/0, c_module/0, c_tuple/0, + c_let/0, c_literal/0, c_map/0, c_map_pair/0, + c_module/0, c_tuple/0, c_values/0, c_var/0, cerl/0, var_name/0]). -include("core_parse.hrl"). diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index 68272689c2..dc996dc73f 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -1965,6 +1965,107 @@ letify(Bs, Body) -> cerl:ann_c_let(Ann, [V], Val, B) end, Body, Bs). +%% opt_not_in_let(Let) -> Cerl +%% Try to optimize away a 'not' operator in a 'let'. + +-spec opt_not_in_let(cerl:c_let()) -> cerl:cerl(). + +opt_not_in_let(#c_let{vars=[_]=Vs0,arg=Arg0,body=Body0}=Let) -> + case opt_not_in_let(Vs0, Arg0, Body0) of + {[],#c_values{es=[]},Body} -> + Body; + {Vs,Arg,Body} -> + Let#c_let{vars=Vs,arg=Arg,body=Body} + end; +opt_not_in_let(Let) -> Let. + +%% opt_not_in_let(Vs, Arg, Body) -> {Vs',Arg',Body'} +%% Try to optimize away a 'not' operator in a 'let'. + +-spec opt_not_in_let([cerl:c_var()], cerl:cerl(), cerl:cerl()) -> + {[cerl:c_var()],cerl:cerl(),cerl:cerl()}. + +opt_not_in_let([#c_var{name=V}]=Vs0, Arg0, Body0) -> + case cerl:type(Body0) of + call -> + %% let <V> = Expr in not V ==> + %% let <> = <> in notExpr + case opt_not_in_let_1(V, Body0, Arg0) of + no -> + {Vs0,Arg0,Body0}; + {yes,Body} -> + {[],#c_values{es=[]},Body} + end; + 'let' -> + %% let <V> = Expr in let <Var> = not V in Body ==> + %% let <Var> = notExpr in Body + %% V must not be used in Body. + LetArg = cerl:let_arg(Body0), + case opt_not_in_let_1(V, LetArg, Arg0) of + no -> + {Vs0,Arg0,Body0}; + {yes,Arg} -> + LetBody = cerl:let_body(Body0), + case core_lib:is_var_used(V, LetBody) of + true -> + {Vs0,Arg0,Body0}; + false -> + LetVars = cerl:let_vars(Body0), + {LetVars,Arg,LetBody} + end + end; + _ -> + {Vs0,Arg0,Body0} + end; +opt_not_in_let(Vs, Arg, Body) -> + {Vs,Arg,Body}. + +opt_not_in_let_1(V, Call, Body) -> + case Call of + #c_call{module=#c_literal{val=erlang}, + name=#c_literal{val='not'}, + args=[#c_var{name=V}]} -> + opt_not_in_let_2(Body); + _ -> + no + end. + +opt_not_in_let_2(#c_case{clauses=Cs0}=Case) -> + Vars = make_vars([], 1), + Body = #c_call{module=#c_literal{val=erlang}, + name=#c_literal{val='not'}, + args=Vars}, + Cs = [begin + Let = #c_let{vars=Vars,arg=B,body=Body}, + C#c_clause{body=opt_not_in_let(Let)} + end || #c_clause{body=B}=C <- Cs0], + {yes,Case#c_case{clauses=Cs}}; +opt_not_in_let_2(#c_call{}=Call0) -> + invert_call(Call0); +opt_not_in_let_2(_) -> no. + +invert_call(#c_call{module=#c_literal{val=erlang}, + name=#c_literal{val=Name0}, + args=[_,_]}=Call) -> + case inverse_rel_op(Name0) of + no -> no; + Name -> {yes,Call#c_call{name=#c_literal{val=Name}}} + end; +invert_call(#c_call{}) -> no. + +%% inverse_rel_op(Op) -> no | RevOp + +inverse_rel_op('=:=') -> '=/='; +inverse_rel_op('=/=') -> '=:='; +inverse_rel_op('==') -> '/='; +inverse_rel_op('/=') -> '=='; +inverse_rel_op('>') -> '=<'; +inverse_rel_op('<') -> '>='; +inverse_rel_op('>=') -> '<'; +inverse_rel_op('=<') -> '>'; +inverse_rel_op(_) -> no. + + %% opt_case_in_let(LetExpr) -> LetExpr' opt_case_in_let(#c_let{vars=Vs,arg=Arg,body=B}=Let, Sub) -> @@ -2272,19 +2373,28 @@ is_failing_clause(#c_clause{body=B}) -> %% Optimize a let construct that does not contain any lets in %% in its argument. -opt_simple_let(#c_let{arg=Arg0}=Let, Ctxt, Sub0) -> - Arg = body(Arg0, value, Sub0), %This is a body +opt_simple_let(Let0, Ctxt, Sub) -> + case opt_not_in_let(Let0) of + #c_let{}=Let -> + opt_simple_let_0(Let, Ctxt, Sub); + Expr -> + expr(Expr, Ctxt, Sub) + end. + +opt_simple_let_0(#c_let{arg=Arg0}=Let, Ctxt, Sub) -> + Arg = body(Arg0, value, Sub), %This is a body case will_fail(Arg) of true -> Arg; - false -> opt_simple_let_1(Let, Arg, Ctxt, Sub0) + false -> opt_simple_let_1(Let, Arg, Ctxt, Sub) end. 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), - B = body(B0, Ctxt, BodySub), - Arg = core_lib:make_values(Args), + {Vs1,Args,Sub1} = let_substs(Vs0, Arg0, Sub0), + BodySub = update_let_types(Vs1, Args, Sub1), + B1 = body(B0, Ctxt, BodySub), + Arg1 = core_lib:make_values(Args), + {Vs,Arg,B} = opt_not_in_let(Vs1, Arg1, B1), opt_simple_let_2(Let, Vs, Arg, B, B0, Ctxt, Sub1). opt_simple_let_2(Let0, Vs0, Arg0, Body, PrevBody, Ctxt, Sub) -> diff --git a/lib/compiler/test/andor_SUITE.erl b/lib/compiler/test/andor_SUITE.erl index 3199440d84..4d7f444c4f 100644 --- a/lib/compiler/test/andor_SUITE.erl +++ b/lib/compiler/test/andor_SUITE.erl @@ -370,6 +370,11 @@ combined(Config) when is_list(Config) -> ?line true = ?COMB(false, blurf, true), ?line true = ?COMB(true, true, blurf), + false = simple_comb(false, false), + false = simple_comb(false, true), + false = simple_comb(true, false), + true = simple_comb(true, true), + ok. -undef(COMB). @@ -396,6 +401,13 @@ comb(A, B, C) -> end, id(Res). +simple_comb(A, B) -> + %% Use Res twice, to ensure that a careless optimization of 'not' + %% doesn't leave Res as a free variable. + Res = A andalso B, + _ = id(not Res), + Res. + %% Test that a boolean expression in a case expression is properly %% optimized (in particular, that the error behaviour is correct). in_case(Config) when is_list(Config) -> |