Fate compiler #553

Merged
zxq9 merged 87 commits from fate-compiler into master 2019-05-07 22:48:47 +09:00
Showing only changes of commit ac25a8fc55 - Show all commits

View File

@ -10,6 +10,7 @@
-module(aeso_fcode_to_fate). -module(aeso_fcode_to_fate).
-export([compile/2]). -export([compile/2]).
-compile([export_all, no_warn_export_all]).
%% -- Preamble --------------------------------------------------------------- %% -- Preamble ---------------------------------------------------------------
@ -226,7 +227,7 @@ ann_writes([{ifte, Then, Else} | Code], Writes, Acc) ->
Writes1 = ordsets:union(Writes, ordsets:intersection(WritesThen, WritesElse)), Writes1 = ordsets:union(Writes, ordsets:intersection(WritesThen, WritesElse)),
ann_writes(Code, Writes1, [{ifte, Then1, Else1} | Acc]); ann_writes(Code, Writes1, [{ifte, Then1, Else1} | Acc]);
ann_writes([I | Code], Writes, Acc) -> ann_writes([I | Code], Writes, Acc) ->
#{ write := Ws } = attributes(I), Ws = var_writes(I),
Writes1 = ordsets:union(Writes, Ws), Writes1 = ordsets:union(Writes, Ws),
Ann = #{ writes_in => Writes, writes_out => Writes1 }, Ann = #{ writes_in => Writes, writes_out => Writes1 },
ann_writes(Code, Writes1, [{Ann, I} | Acc]); ann_writes(Code, Writes1, [{Ann, I} | Acc]);
@ -241,14 +242,14 @@ ann_reads([{ifte, Then, Else} | Code], Reads, Acc) ->
ann_reads(Code, Reads1, [{ifte, Then1, Else1} | Acc]); ann_reads(Code, Reads1, [{ifte, Then1, Else1} | Acc]);
ann_reads([{Ann, I} | Code], Reads, Acc) -> ann_reads([{Ann, I} | Code], Reads, Acc) ->
#{ writes_in := WritesIn, writes_out := WritesOut } = Ann, #{ writes_in := WritesIn, writes_out := WritesOut } = Ann,
#{ read := Rs, write := Ws, pure := Pure } = attributes(I), #{ read := Rs, write := W, pure := Pure } = attributes(I),
Reads1 = Reads1 =
case Pure andalso length(Ws) == 1 andalso not ordsets:is_element(hd(Ws), Reads) of case {W, Pure andalso not ordsets:is_element(W, Reads)} of
%% This is a little bit dangerous: if writing to a dead variable, we ignore %% This is a little bit dangerous: if writing to a dead variable, we ignore
%% the reads. Relies on dead writes to be removed by the %% the reads. Relies on dead writes to be removed by the
%% optimisations below (r_write_to_dead_var). %% optimisations below (r_write_to_dead_var).
true -> Reads; {{var, _}, true} -> Reads;
false -> ordsets:union(Reads, Rs) _ -> ordsets:union(Reads, Rs)
end, end,
LiveIn = ordsets:intersection(Reads1, WritesIn), LiveIn = ordsets:intersection(Reads1, WritesIn),
LiveOut = ordsets:intersection(Reads, WritesOut), LiveOut = ordsets:intersection(Reads, WritesOut),
@ -256,127 +257,151 @@ ann_reads([{Ann, I} | Code], Reads, Acc) ->
ann_reads(Code, Reads1, [{Ann1, I} | Acc]); ann_reads(Code, Reads1, [{Ann1, I} | Acc]);
ann_reads([], Reads, Acc) -> {Acc, Reads}. ann_reads([], Reads, Acc) -> {Acc, Reads}.
%% Read/write to variables and purity. %% Instruction attributes: reads, writes and purity (pure means no side-effects
%% aside from the reads and writes).
attributes(I) -> attributes(I) ->
Set = fun(L) when is_list(L) -> ordsets:from_list([X || X <- L, X /= ?a]); Set = fun(L) when is_list(L) -> ordsets:from_list(L);
(X) -> ordsets:from_list([X || X /= ?a]) end, (X) -> ordsets:from_list([X]) end,
WR = fun(W, R) -> #{read => Set(R), write => Set(W), pure => false} end, Attr = fun(W, R, P) -> #{read => Set(R), write => W, pure => P} end,
R = fun(X) -> WR([], X) end, Pure = fun(W, R) -> Attr(W, R, true) end,
W = fun(X) -> WR(X, []) end, Impure = fun(W, R) -> Attr(W, R, false) end,
None = WR([], []),
Pure = fun(A) -> A#{ pure := true } end,
case I of case I of
'RETURN' -> None; 'RETURN' -> Impure(pc, []);
{'RETURNR', A} -> R(A); {'RETURNR', A} -> Impure(pc, A);
{'CALL', _} -> None; {'CALL', _} -> Impure(?a, []);
{'CALL_R', A, _} -> R(A); {'CALL_R', A, _} -> Impure(?a, A);
{'CALL_T', _} -> None; {'CALL_T', _} -> Impure(pc, []);
{'CALL_TR', A, _} -> R(A); {'CALL_TR', A, _} -> Impure(pc, A);
{'JUMP', _} -> Pure(None); {'JUMP', _} -> Impure(pc, []);
{'JUMPIF', A, _} -> Pure(R(A)); {'JUMPIF', A, _} -> Impure(pc, A);
{'SWITCH_V2', A, _, _} -> Pure(R(A)); {'SWITCH_V2', A, _, _} -> Impure(pc, A);
{'SWITCH_V3', A, _, _, _} -> Pure(R(A)); {'SWITCH_V3', A, _, _, _} -> Impure(pc, A);
{'SWITCH_VN', A, _} -> Pure(R(A)); {'SWITCH_VN', A, _} -> Impure(pc, A);
{'PUSH', A} -> Pure(R(A)); {'PUSH', A} -> Pure(?a, A);
'DUPA' -> Pure(None); 'DUPA' -> Pure(?a, []);
{'DUP', A} -> Pure(R(A)); {'DUP', A} -> Pure(?a, A);
{'POP', A} -> Pure(W(A)); {'POP', A} -> Pure(A, ?a);
{'STORE', A, B} -> Pure(WR(A, B)); {'STORE', A, B} -> Pure(A, B);
'INCA' -> Pure(None); 'INCA' -> Pure(?a, ?a);
{'INC', A} -> Pure(WR(A, A)); {'INC', A} -> Pure(A, A);
'DECA' -> Pure(None); 'DECA' -> Pure(?a, []);
{'DEC', A} -> Pure(WR(A, A)); {'DEC', A} -> Pure(A, A);
{'ADD', A, B, C} -> Pure(WR(A, [B, C])); {'ADD', A, B, C} -> Pure(A, [B, C]);
{'SUB', A, B, C} -> Pure(WR(A, [B, C])); {'SUB', A, B, C} -> Pure(A, [B, C]);
{'MUL', A, B, C} -> Pure(WR(A, [B, C])); {'MUL', A, B, C} -> Pure(A, [B, C]);
{'DIV', A, B, C} -> Pure(WR(A, [B, C])); {'DIV', A, B, C} -> Pure(A, [B, C]);
{'MOD', A, B, C} -> Pure(WR(A, [B, C])); {'MOD', A, B, C} -> Pure(A, [B, C]);
{'POW', A, B, C} -> Pure(WR(A, [B, C])); {'POW', A, B, C} -> Pure(A, [B, C]);
{'LT', A, B, C} -> Pure(WR(A, [B, C])); {'LT', A, B, C} -> Pure(A, [B, C]);
{'GT', A, B, C} -> Pure(WR(A, [B, C])); {'GT', A, B, C} -> Pure(A, [B, C]);
{'EQ', A, B, C} -> Pure(WR(A, [B, C])); {'EQ', A, B, C} -> Pure(A, [B, C]);
{'ELT', A, B, C} -> Pure(WR(A, [B, C])); {'ELT', A, B, C} -> Pure(A, [B, C]);
{'EGT', A, B, C} -> Pure(WR(A, [B, C])); {'EGT', A, B, C} -> Pure(A, [B, C]);
{'NEQ', A, B, C} -> Pure(WR(A, [B, C])); {'NEQ', A, B, C} -> Pure(A, [B, C]);
{'AND', A, B, C} -> Pure(WR(A, [B, C])); {'AND', A, B, C} -> Pure(A, [B, C]);
{'OR', A, B, C} -> Pure(WR(A, [B, C])); {'OR', A, B, C} -> Pure(A, [B, C]);
{'NOT', A, B} -> Pure(WR(A, B)); {'NOT', A, B} -> Pure(A, B);
{'TUPLE', _} -> Pure(None); {'TUPLE', _} -> Pure(?a, []);
{'ELEMENT', A, B, C} -> Pure(WR(A, [B, C])); {'ELEMENT', A, B, C} -> Pure(A, [B, C]);
{'MAP_EMPTY', A} -> Pure(W(A)); {'MAP_EMPTY', A} -> Pure(A, []);
{'MAP_LOOKUP', A, B, C} -> Pure(WR(A, [B, C])); {'MAP_LOOKUP', A, B, C} -> Pure(A, [B, C]);
{'MAP_LOOKUPD', A, B, C, D} -> Pure(WR(A, [B, C, D])); {'MAP_LOOKUPD', A, B, C, D} -> Pure(A, [B, C, D]);
{'MAP_UPDATE', A, B, C, D} -> Pure(WR(A, [B, C, D])); {'MAP_UPDATE', A, B, C, D} -> Pure(A, [B, C, D]);
{'MAP_DELETE', A, B, C} -> Pure(WR(A, [B, C])); {'MAP_DELETE', A, B, C} -> Pure(A, [B, C]);
{'MAP_MEMBER', A, B, C} -> Pure(WR(A, [B, C])); {'MAP_MEMBER', A, B, C} -> Pure(A, [B, C]);
{'MAP_FROM_LIST', A, B} -> Pure(WR(A, B)); {'MAP_FROM_LIST', A, B} -> Pure(A, B);
{'NIL', A} -> Pure(W(A)); {'NIL', A} -> Pure(A, []);
{'IS_NIL', A, B} -> Pure(WR(A, B)); {'IS_NIL', A, B} -> Pure(A, B);
{'CONS', A, B, C} -> Pure(WR(A, [B, C])); {'CONS', A, B, C} -> Pure(A, [B, C]);
{'HD', A, B} -> Pure(WR(A, B)); {'HD', A, B} -> Pure(A, B);
{'TL', A, B} -> Pure(WR(A, B)); {'TL', A, B} -> Pure(A, B);
{'LENGTH', A, B} -> Pure(WR(A, B)); {'LENGTH', A, B} -> Pure(A, B);
{'STR_EQ', A, B, C} -> Pure(WR(A, [B, C])); {'STR_EQ', A, B, C} -> Pure(A, [B, C]);
{'STR_JOIN', A, B, C} -> Pure(WR(A, [B, C])); {'STR_JOIN', A, B, C} -> Pure(A, [B, C]);
{'INT_TO_STR', A, B} -> Pure(WR(A, B)); {'INT_TO_STR', A, B} -> Pure(A, B);
{'ADDR_TO_STR', A, B} -> Pure(WR(A, B)); {'ADDR_TO_STR', A, B} -> Pure(A, B);
{'STR_REVERSE', A, B} -> Pure(WR(A, B)); {'STR_REVERSE', A, B} -> Pure(A, B);
{'INT_TO_ADDR', A, B} -> Pure(WR(A, B)); {'INT_TO_ADDR', A, B} -> Pure(A, B);
{'VARIANT', A, B, C, D} -> Pure(WR(A, [B, C, D])); {'VARIANT', A, B, C, D} -> Pure(A, [B, C, D]);
{'VARIANT_TEST', A, B, C} -> Pure(WR(A, [B, C])); {'VARIANT_TEST', A, B, C} -> Pure(A, [B, C]);
{'VARIANT_ELEMENT', A, B, C} -> Pure(WR(A, [B, C])); {'VARIANT_ELEMENT', A, B, C} -> Pure(A, [B, C]);
'BITS_NONEA' -> Pure(None); 'BITS_NONEA' -> Pure(?a, []);
{'BITS_NONE', A} -> Pure(W(A)); {'BITS_NONE', A} -> Pure(A, []);
'BITS_ALLA' -> Pure(None); 'BITS_ALLA' -> Pure(?a, []);
{'BITS_ALL', A} -> Pure(W(A)); {'BITS_ALL', A} -> Pure(A, []);
{'BITS_ALL_N', A, B} -> Pure(WR(A, B)); {'BITS_ALL_N', A, B} -> Pure(A, B);
{'BITS_SET', A, B, C} -> Pure(WR(A, [B, C])); {'BITS_SET', A, B, C} -> Pure(A, [B, C]);
{'BITS_CLEAR', A, B, C} -> Pure(WR(A, [B, C])); {'BITS_CLEAR', A, B, C} -> Pure(A, [B, C]);
{'BITS_TEST', A, B, C} -> Pure(WR(A, [B, C])); {'BITS_TEST', A, B, C} -> Pure(A, [B, C]);
{'BITS_SUM', A, B} -> Pure(WR(A, B)); {'BITS_SUM', A, B} -> Pure(A, B);
{'BITS_OR', A, B, C} -> Pure(WR(A, [B, C])); {'BITS_OR', A, B, C} -> Pure(A, [B, C]);
{'BITS_AND', A, B, C} -> Pure(WR(A, [B, C])); {'BITS_AND', A, B, C} -> Pure(A, [B, C]);
{'BITS_DIFF', A, B, C} -> Pure(WR(A, [B, C])); {'BITS_DIFF', A, B, C} -> Pure(A, [B, C]);
{'ADDRESS', A} -> Pure(W(A)); {'ADDRESS', A} -> Pure(A, []);
{'BALANCE', A} -> Pure(W(A)); {'BALANCE', A} -> Pure(A, []);
{'ORIGIN', A} -> Pure(W(A)); {'ORIGIN', A} -> Pure(A, []);
{'CALLER', A} -> Pure(W(A)); {'CALLER', A} -> Pure(A, []);
{'GASPRICE', A} -> Pure(W(A)); {'GASPRICE', A} -> Pure(A, []);
{'BLOCKHASH', A} -> Pure(W(A)); {'BLOCKHASH', A} -> Pure(A, []);
{'BENEFICIARY', A} -> Pure(W(A)); {'BENEFICIARY', A} -> Pure(A, []);
{'TIMESTAMP', A} -> Pure(W(A)); {'TIMESTAMP', A} -> Pure(A, []);
{'GENERATION', A} -> Pure(W(A)); {'GENERATION', A} -> Pure(A, []);
{'MICROBLOCK', A} -> Pure(W(A)); {'MICROBLOCK', A} -> Pure(A, []);
{'DIFFICULTY', A} -> Pure(W(A)); {'DIFFICULTY', A} -> Pure(A, []);
{'GASLIMIT', A} -> Pure(W(A)); {'GASLIMIT', A} -> Pure(A, []);
{'GAS', A} -> Pure(W(A)); {'GAS', A} -> Impure(?a, A);
{'LOG0', A, B} -> R([A, B]); {'LOG0', A, B} -> Impure(none, [A, B]);
{'LOG1', A, B, C} -> R([A, B, C]); {'LOG1', A, B, C} -> Impure(none, [A, B, C]);
{'LOG2', A, B, C, D} -> R([A, B, C, D]); {'LOG2', A, B, C, D} -> Impure(none, [A, B, C, D]);
{'LOG3', A, B, C, D, E} -> R([A, B, C, D, E]); {'LOG3', A, B, C, D, E} -> Impure(none, [A, B, C, D, E]);
{'LOG4', A, B, C, D, E, F} -> R([A, B, C, D, E, F]); {'LOG4', A, B, C, D, E, F} -> Impure(none, [A, B, C, D, E, F]);
'DEACTIVATE' -> None; 'DEACTIVATE' -> Impure(none, []);
{'SPEND', A, B} -> R([A, B]); {'SPEND', A, B} -> Impure(none, [A, B]);
{'ORACLE_REGISTER', A, B, C, D, E, F} -> WR(A, [B, C, D, E, F]); {'ORACLE_REGISTER', A, B, C, D, E, F} -> Impure(A, [B, C, D, E, F]);
'ORACLE_QUERY' -> None; %% TODO 'ORACLE_QUERY' -> Impure(?a, []); %% TODO
'ORACLE_RESPOND' -> None; %% TODO 'ORACLE_RESPOND' -> Impure(?a, []); %% TODO
'ORACLE_EXTEND' -> None; %% TODO 'ORACLE_EXTEND' -> Impure(?a, []); %% TODO
'ORACLE_GET_ANSWER' -> None; %% TODO 'ORACLE_GET_ANSWER' -> Impure(?a, []); %% TODO
'ORACLE_GET_QUESTION' -> None; %% TODO 'ORACLE_GET_QUESTION' -> Impure(?a, []); %% TODO
'ORACLE_QUERY_FEE' -> None; %% TODO 'ORACLE_QUERY_FEE' -> Impure(?a, []); %% TODO
'AENS_RESOLVE' -> None; %% TODO 'AENS_RESOLVE' -> Impure(?a, []); %% TODO
'AENS_PRECLAIM' -> None; %% TODO 'AENS_PRECLAIM' -> Impure(?a, []); %% TODO
'AENS_CLAIM' -> None; %% TODO 'AENS_CLAIM' -> Impure(?a, []); %% TODO
'AENS_UPDATE' -> None; %% TODO 'AENS_UPDATE' -> Impure(?a, []); %% TODO
'AENS_TRANSFER' -> None; %% TODO 'AENS_TRANSFER' -> Impure(?a, []); %% TODO
'AENS_REVOKE' -> None; %% TODO 'AENS_REVOKE' -> Impure(?a, []); %% TODO
'ECVERIFY' -> Pure(None); %% TODO 'ECVERIFY' -> Pure(?a, []); %% TODO
'SHA3' -> Pure(None); %% TODO 'SHA3' -> Pure(?a, []); %% TODO
'SHA256' -> Pure(None); %% TODO 'SHA256' -> Pure(?a, []); %% TODO
'BLAKE2B' -> Pure(None); %% TODO 'BLAKE2B' -> Pure(?a, []); %% TODO
{'ABORT', A} -> R(A); {'ABORT', A} -> Impure(pc, A);
{'EXIT', A} -> R(A); {'EXIT', A} -> Impure(pc, A);
'NOP' -> Pure(None) 'NOP' -> Pure(none, [])
end.
var_writes(I) ->
#{ write := W } = attributes(I),
case W of
{var, _} -> [W];
_ -> []
end.
independent({ifte, _, _}, _) -> false;
independent(_, {ifte, _, _}) -> false;
independent(I, J) ->
#{ write := WI, read := RI, pure := PureI } = attributes(I),
#{ write := WJ, read := RJ, pure := PureJ } = attributes(J),
StackI = lists:member(?a, [WI | RI]),
StackJ = lists:member(?a, [WJ | RJ]),
if WI == pc; WJ == pc -> false; %% no jumps
not (PureI or PureJ) -> false; %% at least one is pure
StackI and StackJ -> false; %% cannot both use the stack
true ->
%% and cannot write to each other's inputs
not lists:member(WI, RJ) andalso
not lists:member(WJ, RI)
end. end.
merge_ann(#{ live_in := LiveIn }, #{ live_out := LiveOut }) -> merge_ann(#{ live_in := LiveIn }, #{ live_out := LiveOut }) ->
@ -404,27 +429,38 @@ simpl_s(I, _) -> I.
simpl_top(I, Code, Options) -> simpl_top(I, Code, Options) ->
apply_rules(rules(), I, Code, Options). apply_rules(rules(), I, Code, Options).
apply_rules([], I, Code, _) -> apply_rules(Rules, I, Code, Options) ->
[I | Code];
apply_rules([{_RName, Rule} | Rules], I, Code, Options) ->
Cons = fun(X, Xs) -> simpl_top(X, Xs, Options) end, Cons = fun(X, Xs) -> simpl_top(X, Xs, Options) end,
case Rule(I, Code) of case apply_rules_once(Rules, I, Code) of
false -> apply_rules(Rules, I, Code, Options); false -> [I | Code];
{New, Rest} -> {RName, New, Rest} ->
debug(opt_rules, Options, "Applied ~p:\n~s ==>\n~s", [_RName, pp_ann(" ", [I | Code]), pp_ann(" ", New ++ Rest)]), debug(opt_rules, Options, "Applied ~p:\n~s ==>\n~s", [RName, pp_ann(" ", [I | Code]), pp_ann(" ", New ++ Rest)]),
lists:foldr(Cons, Rest, New) lists:foldr(Cons, Rest, New)
end. end.
apply_rules_once([], _, _) ->
false;
apply_rules_once([{RName, Rule} | Rules], I, Code) ->
case Rule(I, Code) of
false -> apply_rules_once(Rules, I, Code);
{New, Rest} -> {RName, New, Rest}
end.
-define(RULE(Name), {Name, fun Name/2}). -define(RULE(Name), {Name, fun Name/2}).
rules() -> merge_rules() ->
[?RULE(r_push_consume), [?RULE(r_push_consume),
?RULE(r_dup_to_push),
?RULE(r_swap_instrs),
?RULE(r_one_shot_var), ?RULE(r_one_shot_var),
?RULE(r_write_to_dead_var) ?RULE(r_write_to_dead_var)
]. ].
rules() ->
merge_rules() ++
[?RULE(r_dup_to_push),
?RULE(r_swap_push),
?RULE(r_swap_write)
].
%% Removing pushes that are immediately consumed. %% Removing pushes that are immediately consumed.
r_push_consume({Ann1, {'PUSH', A}}, [{Ann2, {Op, R, ?a, B}} | Code]) when ?IsBinOp(Op) -> r_push_consume({Ann1, {'PUSH', A}}, [{Ann2, {Op, R, ?a, B}} | Code]) when ?IsBinOp(Op) ->
{[{merge_ann(Ann1, Ann2), {Op, R, A, B}}], Code}; {[{merge_ann(Ann1, Ann2), {Op, R, A, B}}], Code};
@ -442,27 +478,45 @@ r_push_consume({Ann1, {Op, ?a, A, B}}, [{Ann2, {'STORE', R, ?a}} | Code]) when ?
r_push_consume(_, _) -> false. r_push_consume(_, _) -> false.
%% Changing PUSH A, DUPA to PUSH A, PUSH A enables further optimisations %% Changing PUSH A, DUPA to PUSH A, PUSH A enables further optimisations
r_dup_to_push(I = {Ann, {'PUSH', A}}, [{_, 'DUPA'} | Code]) -> r_dup_to_push({Ann1, Push={'PUSH', _}}, [{Ann2, 'DUPA'} | Code]) ->
#{ live_in := Live } = Ann, #{ live_in := LiveIn } = Ann1,
Ann1 = #{ live_in => Live, live_out => Live }, Ann1_ = Ann1#{ live_out => LiveIn },
{[{Ann1, {'PUSH', A}}, I], Code}; Ann2_ = Ann2#{ live_in => LiveIn },
{[{Ann1_, Push}, {Ann2_, Push}], Code};
r_dup_to_push(_, _) -> false. r_dup_to_push(_, _) -> false.
%% Move PUSH A past an operator. Make sure the next instruction isn't writing %% Move PUSH A past non-stack instructions.
%% to A, pushing to the stack or reading the accumulator. r_swap_push({Ann1, Push = {'PUSH', _}}, [{Ann2, I} | Code]) ->
r_swap_instrs({Ann1, {'PUSH', A}}, [{Ann2, I = {Op, R, B, C}} | Code]) when ?IsBinOp(Op), A /= R, A /= ?a, B /= ?a, C /= ?a -> case independent(Push, I) of
{Ann1_, Ann2_} = swap_ann(Ann1, Ann2), true ->
{[{Ann1_, I}, {Ann2_, {'PUSH', A}}], Code}; {Ann1_, Ann2_} = swap_ann(Ann1, Ann2),
{[{Ann1_, I}, {Ann2_, Push}], Code};
false -> false
end;
r_swap_push(_, _) -> false.
%% Move writes to a variable as late as possible %% Match up writes to variables with instructions further down.
r_swap_instrs({Ann1, I1 = {Op1, R = {var, _}, A, B}}, [{Ann2, I2 = {Op2, S, C, D}} | Code]) r_swap_write({AnnI, I}, [{AnnJ, J} | Code]) ->
when ?IsBinOp(Op1), ?IsBinOp(Op2), case {var_writes(I), independent(I, J)} of
element(1, S) /= var orelse S < R, {[_], true} ->
S /= A, S /= B, C /= R, D /= R, {AnnJ_, AnnI_} = swap_ann(AnnI, AnnJ),
A /= ?a andalso B /= ?a orelse S /= ?a andalso C /= ?a andalso D /= ?a -> r_swap_write([{AnnJ_, J}], {AnnI_, I}, Code);
{Ann1_, Ann2_} = swap_ann(Ann1, Ann2), _ -> false
{[{Ann1_, I2}, {Ann2_, I1}], Code}; end;
r_swap_instrs(_, _) -> false. r_swap_write(_, _) -> false.
r_swap_write(Pre, {AnnI, I}, Code0 = [{AnnJ, J} | Code]) ->
case apply_rules_once(merge_rules(), {AnnI, I}, Code0) of
{_, New, Rest} -> {lists:reverse(Pre) ++ New, Rest};
false ->
case independent(I, J) of
false -> false;
true ->
{AnnJ_, AnnI_} = swap_ann(AnnI, AnnJ),
r_swap_write([{AnnJ_, J} | Pre], {AnnI_, I}, Code)
end
end;
r_swap_write(_, _, []) -> false.
%% Shortcut write followed by final read %% Shortcut write followed by final read
r_one_shot_var({Ann1, {Op, R = {var, _}, A, B}}, [{Ann2, J} | Code]) when ?IsBinOp(Op) -> r_one_shot_var({Ann1, {Op, R = {var, _}, A, B}}, [{Ann2, J} | Code]) when ?IsBinOp(Op) ->