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-rw-r--r--lib/compiler/src/beam_asm.erl2
-rw-r--r--lib/compiler/src/beam_dead.erl20
-rw-r--r--lib/compiler/src/core_lint.erl6
-rw-r--r--lib/compiler/src/sys_core_fold.erl10
-rw-r--r--lib/compiler/src/v3_codegen.erl460
-rw-r--r--lib/compiler/src/v3_core.erl4
-rw-r--r--lib/compiler/src/v3_kernel.erl17
-rw-r--r--lib/compiler/src/v3_kernel.hrl2
8 files changed, 333 insertions, 188 deletions
diff --git a/lib/compiler/src/beam_asm.erl b/lib/compiler/src/beam_asm.erl
index 3dff51d7f6..453e00fce3 100644
--- a/lib/compiler/src/beam_asm.erl
+++ b/lib/compiler/src/beam_asm.erl
@@ -24,7 +24,7 @@
-export([module/4]).
-export([encode/2]).
--export_type([fail/0,label/0,reg/0,src/0,module_code/0,function_name/0]).
+-export_type([fail/0,label/0,reg/0,reg_num/0,src/0,module_code/0,function_name/0]).
-import(lists, [map/2,member/2,keymember/3,duplicate/2,splitwith/2]).
-include("beam_opcodes.hrl").
diff --git a/lib/compiler/src/beam_dead.erl b/lib/compiler/src/beam_dead.erl
index d379fdc4eb..1b152a2d6f 100644
--- a/lib/compiler/src/beam_dead.erl
+++ b/lib/compiler/src/beam_dead.erl
@@ -272,7 +272,8 @@ backward([{jump,{f,To0}},{move,Src,Reg}=Move|Is], D, Acc) ->
end;
backward([{jump,{f,To}}=J|[{bif,Op,{f,BifFail},Ops,Reg}|Is]=Is0], D, Acc) ->
try replace_comp_op(To, Reg, Op, Ops, D) of
- I -> backward(Is, D, I++Acc)
+ {Test,Jump} ->
+ backward([Jump,Test|Is], D, Acc)
catch
throw:not_possible ->
case To =:= BifFail of
@@ -446,7 +447,7 @@ prune_redundant([], _) -> [].
replace_comp_op(To, Reg, Op, Ops, D) ->
False = comp_op_find_shortcut(To, Reg, {atom,false}, D),
True = comp_op_find_shortcut(To, Reg, {atom,true}, D),
- [bif_to_test(Op, Ops, False),{jump,{f,True}}].
+ {bif_to_test(Op, Ops, False),{jump,{f,True}}}.
comp_op_find_shortcut(To0, Reg, Val, D) ->
case shortcut_select_label(To0, Reg, Val, D) of
@@ -483,15 +484,22 @@ not_possible() -> throw(not_possible).
%% F1: is_eq_exact F2 Reg Lit2 F1: is_eq_exact F2 Reg Lit2
%% L2: .... L2:
%%
-combine_eqs(To, [Reg,{Type,_}=Lit1]=Ops, D, [{label,L1}|_])
- when Type =:= atom; Type =:= integer ->
+combine_eqs(To, [Reg,{Type,_}=Lit1]=Ops, D, Acc)
+ when Type =:= atom; Type =:= integer ->
+ Next = case Acc of
+ [{label,Lbl}|_] -> Lbl;
+ [{jump,{f,Lbl}}|_] -> Lbl
+ end,
case beam_utils:code_at(To, D) of
[{test,is_eq_exact,{f,F2},[Reg,{Type,_}=Lit2]},
{label,L2}|_] when Lit1 =/= Lit2 ->
- {select,select_val,Reg,{f,F2},[Lit1,{f,L1},Lit2,{f,L2}]};
+ {select,select_val,Reg,{f,F2},[Lit1,{f,Next},Lit2,{f,L2}]};
+ [{test,is_eq_exact,{f,F2},[Reg,{Type,_}=Lit2]},
+ {jump,{f,L2}}|_] when Lit1 =/= Lit2 ->
+ {select,select_val,Reg,{f,F2},[Lit1,{f,Next},Lit2,{f,L2}]};
[{select,select_val,Reg,{f,F2},[{Type,_}|_]=List0}|_] ->
List = remove_from_list(Lit1, List0),
- {select,select_val,Reg,{f,F2},[Lit1,{f,L1}|List]};
+ {select,select_val,Reg,{f,F2},[Lit1,{f,Next}|List]};
_Is ->
{test,is_eq_exact,{f,To},Ops}
end;
diff --git a/lib/compiler/src/core_lint.erl b/lib/compiler/src/core_lint.erl
index 7d3513c0ba..6e2114be56 100644
--- a/lib/compiler/src/core_lint.erl
+++ b/lib/compiler/src/core_lint.erl
@@ -353,12 +353,6 @@ expr(#c_case{arg=Arg,clauses=Cs}, Def, Rt, St0) ->
Pc = case_patcount(Cs),
St1 = body(Arg, Def, Pc, St0),
clauses(Cs, Def, Pc, Rt, St1);
-expr(#c_receive{clauses=Cs,timeout=#c_literal{val=infinity},
- action=#c_literal{}},
- Def, Rt, St) ->
- %% If the timeout is 'infinity', the after code can never
- %% be reached. We don't care if the return count is wrong.
- clauses(Cs, Def, 1, Rt, St);
expr(#c_receive{clauses=Cs,timeout=T,action=A}, Def, Rt, St0) ->
St1 = expr(T, Def, 1, St0),
St2 = body(A, Def, Rt, St1),
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl
index 6da68f1f4e..f8a467d6a9 100644
--- a/lib/compiler/src/sys_core_fold.erl
+++ b/lib/compiler/src/sys_core_fold.erl
@@ -2624,9 +2624,13 @@ delay_build_expr_1(#c_receive{clauses=Cs0,
timeout=Timeout,
action=A0}=Rec, TypeSig) ->
Cs = delay_build_cs(Cs0, TypeSig),
- A = case Timeout of
- #c_literal{val=infinity} -> A0;
- _ -> delay_build_expr(A0, TypeSig)
+ A = case {Timeout,A0} of
+ {#c_literal{val=infinity},#c_literal{}} ->
+ {_Type,Arity} = TypeSig,
+ Es = lists:duplicate(Arity, A0),
+ core_lib:make_values(Es);
+ _ ->
+ delay_build_expr(A0, TypeSig)
end,
Rec#c_receive{clauses=Cs,action=A};
delay_build_expr_1(#c_seq{body=B0}=Seq, TypeSig) ->
diff --git a/lib/compiler/src/v3_codegen.erl b/lib/compiler/src/v3_codegen.erl
index 9bcd6987bf..74d64e1456 100644
--- a/lib/compiler/src/v3_codegen.erl
+++ b/lib/compiler/src/v3_codegen.erl
@@ -51,7 +51,7 @@ set_kanno(Kthing, Anno) -> setelement(2, Kthing, Anno).
%% Stack/register state record.
-record(sr, {reg=[], %Register table
stk=[], %Stack table
- res=[]}). %Reserved regs: [{reserved,I,V}]
+ res=[]}). %Registers to reserve
%% Internal records.
-record(cg_need_heap, {anno=[] :: term(),
@@ -77,10 +77,15 @@ functions(Forms, AtomMod) ->
function(#k_fdef{anno=#k{a=Anno},func=Name,arity=Arity,
vars=As,body=Kb}, AtomMod, St0) ->
try
- %% Annotate kernel records with variable usage.
#k_match{} = Kb, %Assertion.
+
+ %% Try to suppress the stack frame unless it is
+ %% really needed.
+ Body0 = avoid_stack_frame(Kb),
+
+ %% Annotate kernel records with variable usage.
Vdb0 = init_vars(As),
- {Body,_,Vdb} = body(Kb, 1, Vdb0),
+ {Body,_,Vdb} = body(Body0, 1, Vdb0),
%% Generate the BEAM assembly code.
{Asm,EntryLabel,St} = cg_fun(Body, As, Vdb, AtomMod,
@@ -94,6 +99,112 @@ function(#k_fdef{anno=#k{a=Anno},func=Name,arity=Arity,
erlang:raise(Class, Error, Stack)
end.
+
+%% avoid_stack_frame(Kernel) -> Kernel'
+%% If possible, avoid setting up a stack frame. Functions
+%% that only do matching, calls to guard BIFs, and tail-recursive
+%% calls don't need a stack frame.
+
+avoid_stack_frame(#k_match{body=Body}=M) ->
+ try
+ M#k_match{body=avoid_stack_frame_1(Body)}
+ catch
+ impossible ->
+ M
+ end.
+
+avoid_stack_frame_1(#k_alt{first=First0,then=Then0}=Alt) ->
+ First = avoid_stack_frame_1(First0),
+ Then = avoid_stack_frame_1(Then0),
+ Alt#k_alt{first=First,then=Then};
+avoid_stack_frame_1(#k_bif{op=Op}=Bif) ->
+ case Op of
+ #k_internal{} ->
+ %% Most internal BIFs clobber the X registers.
+ throw(impossible);
+ _ ->
+ Bif
+ end;
+avoid_stack_frame_1(#k_break{anno=Anno,args=Args}) ->
+ #k_guard_break{anno=Anno,args=Args};
+avoid_stack_frame_1(#k_guard_break{}=Break) ->
+ Break;
+avoid_stack_frame_1(#k_enter{}=Enter) ->
+ %% Tail-recursive calls don't need a stack frame.
+ Enter;
+avoid_stack_frame_1(#k_guard{clauses=Cs0}=Guard) ->
+ Cs = avoid_stack_frame_list(Cs0),
+ Guard#k_guard{clauses=Cs};
+avoid_stack_frame_1(#k_guard_clause{guard=G0,body=B0}=C) ->
+ G = avoid_stack_frame_1(G0),
+ B = avoid_stack_frame_1(B0),
+ C#k_guard_clause{guard=G,body=B};
+avoid_stack_frame_1(#k_match{anno=A,vars=Vs,body=B0,ret=Ret}) ->
+ %% Use #k_guard_match{} instead to avoid saving the X registers
+ %% to the stack before matching.
+ B = avoid_stack_frame_1(B0),
+ #k_guard_match{anno=A,vars=Vs,body=B,ret=Ret};
+avoid_stack_frame_1(#k_guard_match{body=B0}=M) ->
+ B = avoid_stack_frame_1(B0),
+ M#k_guard_match{body=B};
+avoid_stack_frame_1(#k_protected{arg=Arg0}=Prot) ->
+ Arg = avoid_stack_frame_1(Arg0),
+ Prot#k_protected{arg=Arg};
+avoid_stack_frame_1(#k_put{}=Put) ->
+ Put;
+avoid_stack_frame_1(#k_return{}=Ret) ->
+ Ret;
+avoid_stack_frame_1(#k_select{var=#k_var{anno=Vanno},types=Types0}=Select) ->
+ case member(reuse_for_context, Vanno) of
+ false ->
+ Types = avoid_stack_frame_list(Types0),
+ Select#k_select{types=Types};
+ true ->
+ %% Including binary patterns that overwrite the register containing
+ %% the binary with the match context may not be safe. For example,
+ %% bs_match_SUITE:bin_tail_e/1 with inlining will be rejected by
+ %% beam_validator.
+ %%
+ %% Essentially the following code is produced:
+ %%
+ %% bs_match {x,0} => {x,0}
+ %% ...
+ %% bs_match {x,0} => {x,1} %% ILLEGAL
+ %%
+ %% A bs_match instruction will only accept a match context as the
+ %% source operand if the source and destination registers are the
+ %% the same (as in the first bs_match instruction above).
+ %% The second bs_match instruction is therefore illegal.
+ %%
+ %% This situation is avoided if there is a stack frame:
+ %%
+ %% move {x,0} => {y,0}
+ %% bs_match {x,0} => {x,0}
+ %% ...
+ %% bs_match {y,0} => {x,1} %% LEGAL
+ %%
+ throw(impossible)
+ end;
+avoid_stack_frame_1(#k_seq{arg=A0,body=B0}=Seq) ->
+ A = avoid_stack_frame_1(A0),
+ B = avoid_stack_frame_1(B0),
+ Seq#k_seq{arg=A,body=B};
+avoid_stack_frame_1(#k_test{}=Test) ->
+ Test;
+avoid_stack_frame_1(#k_type_clause{values=Values0}=TC) ->
+ Values = avoid_stack_frame_list(Values0),
+ TC#k_type_clause{values=Values};
+avoid_stack_frame_1(#k_val_clause{body=B0}=VC) ->
+ B = avoid_stack_frame_1(B0),
+ VC#k_val_clause{body=B};
+avoid_stack_frame_1(_Body) ->
+ throw(impossible).
+
+avoid_stack_frame_list([H|T]) ->
+ [avoid_stack_frame_1(H)|avoid_stack_frame_list(T)];
+avoid_stack_frame_list([]) -> [].
+
+
%% This pass creates beam format annotated with variable lifetime
%% information. Each thing is given an index and for each variable we
%% store the first and last index for its occurrence. The variable
@@ -219,10 +330,8 @@ expr(#k_put{anno=A}=Put, I, _Vdb) ->
Put#k_put{anno=#l{i=I,a=A#k.a}};
expr(#k_break{anno=A}=Break, I, _Vdb) ->
Break#k_break{anno=#l{i=I,a=A#k.a}};
-expr(#k_guard_break{anno=A}=Break, I, Vdb) ->
- Locked = [V || {V,_,_} <- Vdb],
- L = #l{i=I,a=A#k.a},
- Break#k_guard_break{anno=L,locked=Locked};
+expr(#k_guard_break{anno=A}=Break, I, _Vdb) ->
+ Break#k_guard_break{anno=#l{i=I,a=A#k.a}};
expr(#k_return{anno=A}=Ret, I, _Vdb) ->
Ret#k_return{anno=#l{i=I,a=A#k.a}}.
@@ -246,14 +355,9 @@ match(#k_alt{anno=A,first=Kf,then=Kt}, Ls, I, Vdb0) ->
F = match(Kf, Ls, I+1, Vdb1),
T = match(Kt, Ls, I+1, Vdb1),
#k_alt{anno=[],first=F,then=T};
-match(#k_select{anno=A,var=V,types=Kts}=Select, Ls0, I, Vdb0) ->
- Vanno = get_kanno(V),
- Ls1 = case member(no_usage, Vanno) of
- false -> add_element(V#k_var.name, Ls0);
- true -> Ls0
- end,
- Vdb1 = use_vars(union(A#k.us, Ls1), I, Vdb0),
- Ts = [type_clause(Tc, Ls1, I+1, Vdb1) || Tc <- Kts],
+match(#k_select{anno=A,types=Kts}=Select, Ls, I, Vdb0) ->
+ Vdb1 = use_vars(union(A#k.us, Ls), I, Vdb0),
+ Ts = [type_clause(Tc, Ls, I+1, Vdb1) || Tc <- Kts],
Select#k_select{anno=[],types=Ts};
match(#k_guard{anno=A,clauses=Kcs}, Ls, I, Vdb0) ->
Vdb1 = use_vars(union(A#k.us, Ls), I, Vdb0),
@@ -388,8 +492,8 @@ cg(#k_return{anno=Le,args=Rs}, Vdb, Bef, St) ->
return_cg(Rs, Le, Vdb, Bef, St);
cg(#k_break{anno=Le,args=Bs}, Vdb, Bef, St) ->
break_cg(Bs, Le, Vdb, Bef, St);
-cg(#k_guard_break{anno=Le,args=Bs,locked=N}, Vdb, Bef, St) ->
- guard_break_cg(Bs, N, Le, Vdb, Bef, St);
+cg(#k_guard_break{anno=Le,args=Bs}, Vdb, Bef, St) ->
+ guard_break_cg(Bs, Le, Vdb, Bef, St);
cg(#cg_need_heap{h=H}, _Vdb, Bef, St) ->
{[{test_heap,H,max_reg(Bef#sr.reg)}],Bef,St}.
@@ -487,7 +591,10 @@ match_cg(M, Rs, Le, Vdb, Bef, St0) ->
guard_match_cg(M, Rs, Le, Vdb, Bef, St0) ->
I = Le#l.i,
{B,St1} = new_label(St0),
- #cg{bfail=Fail} = St1,
+ Fail = case St0 of
+ #cg{bfail=0,ultimate_failure=Fail0} -> Fail0;
+ #cg{bfail=Fail0} -> Fail0
+ end,
{Mis,Aft,St2} = match_cg(M, Fail, Bef, St1#cg{break=B}),
%% Update the register descriptors for the return registers.
Reg = guard_match_regs(Aft#sr.reg, Rs),
@@ -593,9 +700,6 @@ bsm_rename_ctx(#k_protected{arg=Ts0}=Prot, Old, New, _InProt) ->
InProt = true,
Ts = bsm_rename_ctx_list(Ts0, Old, New, InProt),
bsm_forget_var(Prot#k_protected{arg=Ts}, Old);
-bsm_rename_ctx(#k_match{body=Ms0}=Match, Old, New, InProt) ->
- Ms = bsm_rename_ctx(Ms0, Old, New, InProt),
- Match#k_match{body=Ms};
bsm_rename_ctx(#k_guard_match{body=Ms0}=Match, Old, New, InProt) ->
Ms = bsm_rename_ctx(Ms0, Old, New, InProt),
Match#k_guard_match{body=Ms};
@@ -612,9 +716,8 @@ bsm_rename_ctx(#cg_block{es=Es0}=Block, Old, New, true) ->
%% inside the block.
Es = bsm_rename_ctx_list(Es0, Old, New, true),
bsm_forget_var(Block#cg_block{es=Es}, Old);
-bsm_rename_ctx(#k_guard_break{locked=Locked0}=Break, Old, _New, _InProt) ->
- Locked = Locked0 -- [Old],
- bsm_forget_var(Break#k_guard_break{locked=Locked}, Old).
+bsm_rename_ctx(#k_guard_break{}=Break, Old, _New, _InProt) ->
+ bsm_forget_var(Break, Old).
bsm_rename_ctx_list([C|Cs], Old, New, InProt) ->
[bsm_rename_ctx(C, Old, New, InProt)|
@@ -679,129 +782,158 @@ basic_block([Ke|Kes], Acc) ->
no_block -> {reverse(Acc, [Ke]),Kes}
end.
-%% #k_put{} instructions that may garbage collect are not allowed in basic blocks.
-
-collect_block(#k_put{arg=#k_binary{}}) ->
- no_block;
-collect_block(#k_put{arg=#k_map{}}) ->
- no_block;
-collect_block(#k_put{}) ->
- include;
-collect_block(#k_call{op=#k_var{}=Var,args=As}) ->
- {block_end,As++[Var]};
+collect_block(#k_put{arg=Arg}) ->
+ %% #k_put{} instructions that may garbage collect are not allowed
+ %% in basic blocks.
+ case Arg of
+ #k_binary{} -> no_block;
+ #k_map{} -> no_block;
+ _ -> include
+ end;
collect_block(#k_call{op=Func,args=As}) ->
{block_end,As++func_vars(Func)};
-collect_block(#k_enter{op=#k_var{}=Var,args=As}) ->
- {block_end,As++[Var]};
collect_block(#k_enter{op=Func,args=As}) ->
{block_end,As++func_vars(Func)};
collect_block(#k_return{args=Rs}) ->
{block_end,Rs};
collect_block(#k_break{args=Bs}) ->
{block_end,Bs};
-collect_block(_) -> no_block.
+collect_block(_) -> no_block.
+func_vars(#k_var{}=Var) ->
+ [Var];
func_vars(#k_remote{mod=M,name=F})
when is_record(M, k_var); is_record(F, k_var) ->
[M,F];
func_vars(_) -> [].
-%% cg_basic_block([Kexpr], FirstI, LastI, As, Vdb, StackReg, State) ->
+%% cg_basic_block([Kexpr], FirstI, LastI, Arguments, Vdb, StackReg, State) ->
%% {[Ainstr],StackReg,State}.
+%%
+%% Do a specialized code generation for a basic block of #put{}
+%% instructions (that don't do any garbage collection) followed by a
+%% call, break, or return.
+%%
+%% 'Arguments' is a list of the variables that must be loaded into
+%% consecutive X registers before the last instruction in the block.
+%% The point of this specialized code generation is to try put the
+%% all of the variables in 'Arguments' into the correct X register
+%% to begin with, instead of putting them into the first available
+%% X register and having to move them to the correct X register
+%% later.
+%%
+%% To achieve that, we attempt to reserve the X registers that the
+%% variables in 'Arguments' will need to be in when the block ends.
+%%
+%% To make it more likely that reservations will be successful, we
+%% will try to save variables that need to be saved to the stack as
+%% early as possible (if an X register needed by a variable in
+%% Arguments is occupied by another variable, the value in the
+%% X register can be evicted if it is saved on the stack).
+%%
+%% We will take care not to increase the size of stack frame compared
+%% to what the standard code generator would have done (that is, to
+%% save all X registers at the last possible moment). We will do that
+%% by extending the stack frame to the minimal size needed to save
+%% all that needs to be saved using extend_stack/4, and use
+%% save_carefully/4 during code generation to only save the variables
+%% that can be saved without growing the stack frame.
cg_basic_block(Kes, Fb, Lf, As, Vdb, Bef, St0) ->
- Res = make_reservation(As, 0),
- Regs0 = reserve(Res, Bef#sr.reg, Bef#sr.stk),
- Stk = extend_stack(Bef, Lf, Lf+1, Vdb),
- Int0 = Bef#sr{reg=Regs0,stk=Stk,res=Res},
- X0_v0 = x0_vars(As, Fb, Lf, Vdb),
- {Keis,{Aft,_,St1}} =
+ Int0 = reserve_arg_regs(As, Bef),
+ Int = extend_stack(Int0, Lf, Lf+1, Vdb),
+ {Keis,{Aft,St1}} =
flatmapfoldl(fun(Ke, St) -> cg_basic_block(Ke, St, Lf, Vdb) end,
- {Int0,X0_v0,St0}, need_heap(Kes, Fb)),
+ {Int,St0}, need_heap(Kes, Fb)),
{Keis,Aft,St1}.
-cg_basic_block(#cg_need_heap{}=Ke, {Inta,X0v,Sta}, _Lf, Vdb) ->
- {Keis,Intb,Stb} = cg(Ke, Vdb, Inta, Sta),
- {Keis, {Intb,X0v,Stb}};
-cg_basic_block(Ke, {Inta,X0_v1,Sta}, Lf, Vdb) ->
+cg_basic_block(#cg_need_heap{}=Ke, {Bef,St0}, _Lf, Vdb) ->
+ {Keis,Aft,St1} = cg(Ke, Vdb, Bef, St0),
+ {Keis,{Aft,St1}};
+cg_basic_block(Ke, {Bef,St0}, Lf, Vdb) ->
#l{i=I} = get_kanno(Ke),
- {Sis,Intb} = save_carefully(Inta, I, Lf+1, Vdb),
- {X0_v2,Intc} = allocate_x0(X0_v1, I, Intb),
- Intd = reserve(Intc),
- {Keis,Inte,Stb} = cg(Ke, Vdb, Intd, Sta),
- {Sis ++ Keis, {Inte,X0_v2,Stb}}.
-make_reservation([], _) -> [];
-make_reservation([#k_var{name=V}|As], I) -> [{I,V}|make_reservation(As, I+1)];
-make_reservation([A|As], I) -> [{I,A}|make_reservation(As, I+1)].
-
-reserve(Sr) -> Sr#sr{reg=reserve(Sr#sr.res, Sr#sr.reg, Sr#sr.stk)}.
-
-reserve([{I,V}|Rs], [free|Regs], Stk) -> [{reserved,I,V}|reserve(Rs, Regs, Stk)];
-reserve([{I,V}|Rs], [{I,V}|Regs], Stk) -> [{I,V}|reserve(Rs, Regs, Stk)];
-reserve([{I,V}|Rs], [{I,Var}|Regs], Stk) ->
+ %% Save all we can to increase the possibility that reserving
+ %% registers will succeed.
+ {Sis,Int0} = save_carefully(Bef, I, Lf+1, Vdb),
+ Int1 = reserve(Int0),
+ {Keis,Aft,St1} = cg(Ke, Vdb, Int1, St0),
+ {Sis ++ Keis,{Aft,St1}}.
+
+%% reserve_arg_regs([Argument], Bef) -> Aft.
+%% Try to reserve the X registers for all arguments. All registers
+%% that we wish to reserve will be saved in Bef#sr.res.
+
+reserve_arg_regs(As, Bef) ->
+ Res = reserve_arg_regs_1(As, 0),
+ reserve(Bef#sr{res=Res}).
+
+reserve_arg_regs_1([#k_var{name=V}|As], I) ->
+ [{I,V}|reserve_arg_regs_1(As, I+1)];
+reserve_arg_regs_1([A|As], I) ->
+ [{I,A}|reserve_arg_regs_1(As, I+1)];
+reserve_arg_regs_1([], _) -> [].
+
+%% reserve(Bef) -> Aft.
+%% Try to reserve more registers. The registers we wish to reserve
+%% are found in Bef#sr.res.
+
+reserve(#sr{reg=Regs,stk=Stk,res=Res}=Sr) ->
+ Sr#sr{reg=reserve_1(Res, Regs, Stk)}.
+
+reserve_1([{I,V}|Rs], [free|Regs], Stk) ->
+ [{reserved,I,V}|reserve_1(Rs, Regs, Stk)];
+reserve_1([{I,V}|Rs], [{I,V}|Regs], Stk) ->
+ [{I,V}|reserve_1(Rs, Regs, Stk)];
+reserve_1([{I,V}|Rs], [{I,Var}|Regs], Stk) ->
case on_stack(Var, Stk) of
- true -> [{reserved,I,V}|reserve(Rs, Regs, Stk)];
- false -> [{I,Var}|reserve(Rs, Regs, Stk)]
+ true -> [{reserved,I,V}|reserve_1(Rs, Regs, Stk)];
+ false -> [{I,Var}|reserve_1(Rs, Regs, Stk)]
end;
-reserve([{I,V}|Rs], [{reserved,I,_}|Regs], Stk) ->
- [{reserved,I,V}|reserve(Rs, Regs, Stk)];
-%reserve([{I,V}|Rs], [Other|Regs], Stk) -> [Other|reserve(Rs, Regs, Stk)];
-reserve([{I,V}|Rs], [], Stk) -> [{reserved,I,V}|reserve(Rs, [], Stk)];
-reserve([], Regs, _) -> Regs.
-
-extend_stack(Bef, Fb, Lf, Vdb) ->
- Stk0 = clear_dead_stk(Bef#sr.stk, Fb, Vdb),
- Saves = [V || {V,F,L} <- Vdb,
- F < Fb,
- L >= Lf,
- not on_stack(V, Stk0)],
- Stk1 = foldl(fun (V, Stk) -> put_stack(V, Stk) end, Stk0, Saves),
- Bef#sr.stk ++ lists:duplicate(length(Stk1) - length(Bef#sr.stk), free).
-
-save_carefully(Bef, Fb, Lf, Vdb) ->
- Stk = Bef#sr.stk,
- %% New variables that are in use but not on stack.
- New = [VFL || {V,F,L} = VFL <- Vdb,
- F < Fb,
- L >= Lf,
- not on_stack(V, Stk)],
- Saves = [V || {V,_,_} <- keysort(2, New)],
- save_carefully(Saves, Bef, []).
-
-save_carefully([], Bef, Acc) -> {reverse(Acc),Bef};
-save_carefully([V|Vs], Bef, Acc) ->
- case put_stack_carefully(V, Bef#sr.stk) of
- error -> {reverse(Acc),Bef};
+reserve_1([{I,V}|Rs], [{reserved,I,_}|Regs], Stk) ->
+ [{reserved,I,V}|reserve_1(Rs, Regs, Stk)];
+reserve_1([{I,V}|Rs], [], Stk) ->
+ [{reserved,I,V}|reserve_1(Rs, [], Stk)];
+reserve_1([], Regs, _) -> Regs.
+
+%% extend_stack(Bef, FirstBefore, LastFrom, Vdb) -> Aft.
+%% Extend the stack enough to fit all variables alive past LastFrom
+%% and not already on the stack.
+
+extend_stack(#sr{stk=Stk0}=Bef, Fb, Lf, Vdb) ->
+ Stk1 = clear_dead_stk(Stk0, Fb, Vdb),
+ New = new_not_on_stack(Stk1, Fb, Lf, Vdb),
+ Stk2 = foldl(fun ({V,_,_}, Stk) -> put_stack(V, Stk) end, Stk1, New),
+ Stk = Stk0 ++ lists:duplicate(length(Stk2) - length(Stk0), free),
+ Bef#sr{stk=Stk}.
+
+%% save_carefully(Bef, FirstBefore, LastFrom, Vdb) -> {[SaveVar],Aft}.
+%% Save variables which are used past current point and which are not
+%% already on the stack, but only if the variables can be saved without
+%% growing the stack frame.
+
+save_carefully(#sr{stk=Stk}=Bef, Fb, Lf, Vdb) ->
+ New0 = new_not_on_stack(Stk, Fb, Lf, Vdb),
+ New = keysort(2, New0),
+ save_carefully_1(New, Bef, []).
+
+save_carefully_1([{V,_,_}|Vs], #sr{reg=Regs,stk=Stk0}=Bef, Acc) ->
+ case put_stack_carefully(V, Stk0) of
+ error ->
+ {reverse(Acc),Bef};
Stk1 ->
- SrcReg = fetch_reg(V, Bef#sr.reg),
+ SrcReg = fetch_reg(V, Regs),
Move = {move,SrcReg,fetch_stack(V, Stk1)},
{x,_} = SrcReg, %Assertion - must be X register.
- save_carefully(Vs, Bef#sr{stk=Stk1}, [Move|Acc])
- end.
+ save_carefully_1(Vs, Bef#sr{stk=Stk1}, [Move|Acc])
+ end;
+save_carefully_1([], Bef, Acc) ->
+ {reverse(Acc),Bef}.
-x0_vars([], _Fb, _Lf, _Vdb) -> [];
-x0_vars([#k_var{name=V}|_], Fb, _Lf, Vdb) ->
- {V,F,_L} = VFL = vdb_find(V, Vdb),
- x0_vars1([VFL], Fb, F, Vdb);
-x0_vars([X0|_], Fb, Lf, Vdb) ->
- x0_vars1([{X0,Lf,Lf}], Fb, Lf, Vdb).
-
-x0_vars1(X0, Fb, Xf, Vdb) ->
- Vs0 = [VFL || {_V,F,L}=VFL <- Vdb,
- F >= Fb,
- L < Xf],
- Vs1 = keysort(3, Vs0),
- keysort(2, X0++Vs1).
-
-allocate_x0([], _, Bef) -> {[],Bef#sr{res=[]}};
-allocate_x0([{_,_,L}|Vs], I, Bef) when L =< I ->
- allocate_x0(Vs, I, Bef);
-allocate_x0([{V,_F,_L}=VFL|Vs], _, Bef) ->
- {[VFL|Vs],Bef#sr{res=reserve_x0(V, Bef#sr.res)}}.
-
-reserve_x0(V, [_|Res]) -> [{0,V}|Res];
-reserve_x0(V, []) -> [{0,V}].
+%% top_level_block([Instruction], Bef, MaxRegs, St) -> [Instruction].
+%% For the top-level block, allocate a stack frame a necessary,
+%% adjust Y register numbering and instructions that return
+%% from the function.
top_level_block(Keis, #sr{stk=[]}, _MaxRegs, #cg{need_frame=false}) ->
Keis;
@@ -1349,8 +1481,6 @@ guard_clause_cg(#k_guard_clause{anno=#l{vdb=Vdb},guard=G,body=B}, Fail, Bef, St0
guard_cg(#k_protected{arg=Ts,ret=Rs,anno=#l{i=I,vdb=Pdb}}, Fail, _Vdb, Bef, St) ->
protected_cg(Ts, Rs, Fail, I, Pdb, Bef, St);
-guard_cg(#cg_block{es=Ts,anno=#l{i=I,vdb=Bdb}}, Fail, _Vdb, Bef, St) ->
- guard_cg_list(Ts, Fail, I, Bdb, Bef, St);
guard_cg(#k_test{anno=#l{i=I},op=Test0,args=As,inverted=Inverted},
Fail, Vdb, Bef, St0) ->
#k_remote{mod=#k_atom{val=erlang},name=#k_atom{val=Test}} = Test0,
@@ -1368,6 +1498,18 @@ guard_cg(G, _Fail, Vdb, Bef, St) ->
%%ok = io:fwrite("cg ~w: ~p~n", [?LINE,{Aft}]),
{Gis,Aft,St1}.
+%% guard_cg_list([Kexpr], Fail, I, Vdb, StackReg, St) ->
+%% {[Ainstr],StackReg,St}.
+
+guard_cg_list(Kes, Fail, I, Vdb, Bef, St0) ->
+ {Keis,{Aft,St1}} =
+ flatmapfoldl(fun (Ke, {Inta,Sta}) ->
+ {Keis,Intb,Stb} =
+ guard_cg(Ke, Fail, Vdb, Inta, Sta),
+ {Keis,{Intb,Stb}}
+ end, {Bef,St0}, need_heap(Kes, I)),
+ {Keis,Aft,St1}.
+
%% protected_cg([Kexpr], [Ret], Fail, I, Vdb, Bef, St) -> {[Ainstr],Aft,St}.
%% Do a protected. Protecteds without return values are just done
%% for effect, the return value is not checked, success passes on to
@@ -1424,18 +1566,6 @@ test_cg(Test, As, Fail, I, Vdb, Bef, St) ->
Aft = clear_dead(Bef, I, Vdb),
{[beam_utils:bif_to_test(Test, Args, {f,Fail})],Aft,St}.
-%% guard_cg_list([Kexpr], Fail, I, Vdb, StackReg, St) ->
-%% {[Ainstr],StackReg,St}.
-
-guard_cg_list(Kes, Fail, I, Vdb, Bef, St0) ->
- {Keis,{Aft,St1}} =
- flatmapfoldl(fun (Ke, {Inta,Sta}) ->
- {Keis,Intb,Stb} =
- guard_cg(Ke, Fail, Vdb, Inta, Sta),
- {Keis,{Intb,Stb}}
- end, {Bef,St0}, need_heap(Kes, I)),
- {Keis,Aft,St1}.
-
%% match_fmf(Fun, LastFail, State, [Clause]) -> {Is,Aft,State}.
%% This is a special flatmapfoldl for match code gen where we
%% generate a "failure" label for each clause. The last clause uses
@@ -2202,13 +2332,12 @@ break_cg(Bs, Le, Vdb, Bef, St) ->
{Ms ++ [{jump,{f,St#cg.break}}],
Int#sr{reg=clear_regs(Int#sr.reg)},St}.
-guard_break_cg(Bs, Locked, #l{i=I}, Vdb, #sr{reg=Reg0}=Bef, St) ->
- RegLocked = get_locked_regs(Reg0, Locked),
- #sr{reg=Reg1} = Int = clear_dead(Bef#sr{reg=RegLocked}, I, Vdb),
+guard_break_cg(Bs, #l{i=I}, Vdb, #sr{reg=Reg0}=Bef, St) ->
+ #sr{reg=Reg1} = Int = clear_dead(Bef, I, Vdb),
Reg2 = trim_free(Reg1),
NumLocked = length(Reg2),
Moves0 = gen_moves(Bs, Bef, NumLocked, []),
- Moves = order_moves(Moves0, find_scratch_reg(RegLocked)),
+ Moves = order_moves(Moves0, find_scratch_reg(Reg0)),
{BreakVars,_} = mapfoldl(fun(_, RegNum) ->
{{RegNum,gbreakvar},RegNum+1}
end, length(Reg2), Bs),
@@ -2216,20 +2345,6 @@ guard_break_cg(Bs, Locked, #l{i=I}, Vdb, #sr{reg=Reg0}=Bef, St) ->
Aft = Int#sr{reg=Reg},
{Moves ++ [{jump,{f,St#cg.break}}],Aft,St}.
-get_locked_regs([R|Rs0], Preserve) ->
- case {get_locked_regs(Rs0, Preserve),R} of
- {[],{_,V}} ->
- case lists:member(V, Preserve) of
- true -> [R];
- false -> []
- end;
- {[],_} ->
- [];
- {Rs,_} ->
- [R|Rs]
- end;
-get_locked_regs([], _) -> [].
-
%% cg_reg_arg(Arg0, Info) -> Arg
%% cg_reg_args([Arg0], Info) -> [Arg]
%% Convert argument[s] into registers. Literal values are returned unchanged.
@@ -2370,21 +2485,21 @@ break_up_cycle1(Dst, [M|Path], LastMove) ->
%% clear_dead(Sr, Until, Vdb) -> Aft.
%% Remove all variables in Sr which have died AT ALL so far.
-clear_dead(Sr, Until, Vdb) ->
- Sr#sr{reg=clear_dead_reg(Sr, Until, Vdb),
- stk=clear_dead_stk(Sr#sr.stk, Until, Vdb)}.
+clear_dead(#sr{stk=Stk}=Sr0, Until, Vdb) ->
+ Sr = Sr0#sr{reg=clear_dead_reg(Sr0, Until, Vdb),
+ stk=clear_dead_stk(Stk, Until, Vdb)},
+ reserve(Sr).
clear_dead_reg(Sr, Until, Vdb) ->
- Reg = [case R of
- {_I,V} = IV ->
- case vdb_find(V, Vdb) of
- {V,_,L} when L > Until -> IV;
- _ -> free %Remove anything else
- end;
- {reserved,_I,_V} = Reserved -> Reserved;
- free -> free
- end || R <- Sr#sr.reg],
- reserve(Sr#sr.res, Reg, Sr#sr.stk).
+ [case R of
+ {_I,V} = IV ->
+ case vdb_find(V, Vdb) of
+ {V,_,L} when L > Until -> IV;
+ _ -> free %Remove anything else
+ end;
+ {reserved,_I,_V}=Reserved -> Reserved;
+ free -> free
+ end || R <- Sr#sr.reg].
clear_dead_stk(Stk, Until, Vdb) ->
[case S of
@@ -2456,16 +2571,25 @@ adjust_stack(Bef, Fb, Lf, Vdb) ->
save_stack(Stk0, Fb, Lf, Vdb) ->
%% New variables that are in use but not on stack.
- New = [VFL || {V,F,L} = VFL <- Vdb,
- F < Fb,
- L >= Lf,
- not on_stack(V, Stk0)],
+ New = new_not_on_stack(Stk0, Fb, Lf, Vdb),
+
%% Add new variables that are not just dropped immediately.
%% N.B. foldr works backwards from the end!!
Saves = [V || {V,_,_} <- keysort(3, New)],
Stk1 = foldr(fun (V, Stk) -> put_stack(V, Stk) end, Stk0, Saves),
{Stk1,Saves}.
+%% new_not_on_stack(Stack, FirstBefore, LastFrom, Vdb) ->
+%% [{Variable,First,Last}]
+%% Return information about all variables that are used past current
+%% point and that are not already on the stack.
+
+new_not_on_stack(Stk, Fb, Lf, Vdb) ->
+ [VFL || {V,F,L} = VFL <- Vdb,
+ F < Fb,
+ L >= Lf,
+ not on_stack(V, Stk)].
+
%% saves([SaveVar], Reg, Stk) -> [{move,Reg,Stk}].
%% Generate move instructions to save variables onto stack. The
%% stack/reg info used is that after the new stack has been made.
diff --git a/lib/compiler/src/v3_core.erl b/lib/compiler/src/v3_core.erl
index cc8ea475d2..6029b91cdc 100644
--- a/lib/compiler/src/v3_core.erl
+++ b/lib/compiler/src/v3_core.erl
@@ -2482,9 +2482,11 @@ cexpr(#icase{anno=A,args=Largs,clauses=Lcs,fc=Lfc}, As, St0) ->
cexpr(#ireceive1{anno=A,clauses=Lcs}, As, St0) ->
Exp = intersection(A#a.ns, As), %Exports
{Ccs,St1} = cclauses(Lcs, Exp, St0),
+ True = #c_literal{val=true},
+ Action = core_lib:make_values(lists:duplicate(1+length(Exp), True)),
{#c_receive{anno=A#a.anno,
clauses=Ccs,
- timeout=#c_literal{val=infinity},action=#c_literal{val=true}},
+ timeout=#c_literal{val=infinity},action=Action},
Exp,A#a.us,St1};
cexpr(#ireceive2{anno=A,clauses=Lcs,timeout=Lto,action=Les}, As, St0) ->
Exp = intersection(A#a.ns, As), %Exports
diff --git a/lib/compiler/src/v3_kernel.erl b/lib/compiler/src/v3_kernel.erl
index 3eea058153..23625b1f2e 100644
--- a/lib/compiler/src/v3_kernel.erl
+++ b/lib/compiler/src/v3_kernel.erl
@@ -108,6 +108,7 @@ copy_anno(Kdst, Ksrc) ->
-record(iclause, {anno=[],isub,osub,pats,guard,body}).
-record(ireceive_accept, {anno=[],arg}).
-record(ireceive_next, {anno=[],arg}).
+-record(ignored, {anno=[]}).
-type warning() :: term(). % XXX: REFINE
@@ -489,7 +490,7 @@ make_alt(First0, Then0) ->
Then1 = pre_seq(droplast(Then0), last(Then0)),
First2 = make_protected(First1),
Then2 = make_protected(Then1),
- Body = #k_atom{val=ignored},
+ Body = #ignored{},
First3 = #k_guard_clause{guard=First2,body=Body},
Then3 = #k_guard_clause{guard=Then2,body=Body},
First = #k_guard{clauses=[First3]},
@@ -2225,7 +2226,9 @@ ubody(E, return, St0) ->
{Ea,Pa,St1} = force_atomic(E, St0),
ubody(pre_seq(Pa, #ivalues{args=[Ea]}), return, St1)
end;
-ubody(E, {break,_Rs} = Break, St0) ->
+ubody(#ignored{}, {break,_} = Break, St) ->
+ ubody(#ivalues{args=[]}, Break, St);
+ubody(E, {break,[_]} = Break, St0) ->
%%ok = io:fwrite("ubody ~w:~p~n", [?LINE,{E,Br}]),
%% Exiting expressions need no trailing break.
case is_exit_expr(E) of
@@ -2233,6 +2236,16 @@ ubody(E, {break,_Rs} = Break, St0) ->
false ->
{Ea,Pa,St1} = force_atomic(E, St0),
ubody(pre_seq(Pa, #ivalues{args=[Ea]}), Break, St1)
+ end;
+ubody(E, {break,Rs}=Break, St0) ->
+ case is_exit_expr(E) of
+ true ->
+ uexpr(E, return, St0);
+ false ->
+ {Vs,St1} = new_vars(length(Rs), St0),
+ Iset = #iset{vars=Vs,arg=E},
+ PreSeq = pre_seq([Iset], #ivalues{args=Vs}),
+ ubody(PreSeq, Break, St1)
end.
iletrec_funs(#iletrec{defs=Fs}, St0) ->
diff --git a/lib/compiler/src/v3_kernel.hrl b/lib/compiler/src/v3_kernel.hrl
index 87011b7680..7cd30b25a8 100644
--- a/lib/compiler/src/v3_kernel.hrl
+++ b/lib/compiler/src/v3_kernel.hrl
@@ -79,7 +79,7 @@
-record(k_guard_clause, {anno=[],guard,body}).
-record(k_break, {anno=[],args=[]}).
--record(k_guard_break, {anno=[],args=[],locked=[]}).
+-record(k_guard_break, {anno=[],args=[]}).
-record(k_return, {anno=[],args=[]}).
%%k_get_anno(Thing) -> element(2, Thing).