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-rw-r--r--lib/compiler/src/beam_receive.erl92
1 files changed, 40 insertions, 52 deletions
diff --git a/lib/compiler/src/beam_receive.erl b/lib/compiler/src/beam_receive.erl
index 3dd5ed182e..97a9188ee7 100644
--- a/lib/compiler/src/beam_receive.erl
+++ b/lib/compiler/src/beam_receive.erl
@@ -151,20 +151,20 @@ opt_recv(Is, Regs, D) ->
opt_recv([{label,L}=Lbl,{loop_rec,{f,Fail},_}=Loop|Is], D, R0, _, Acc) ->
R = regs_kill_not_live(0, R0),
- case regs_to_list(R) of
- [{y,_}=RefReg] ->
- %% We now have the new reference in the Y register RefReg
+ case regs_empty(R) of
+ false ->
+ %% We now have the new reference in Y registers
%% and the current instruction is the beginning of a
%% receive statement. We must now verify that only messages
%% that contain the reference will be matched.
- case opt_ref_used(Is, RefReg, Fail, D) of
+ case opt_ref_used(Is, R, Fail, D) of
false ->
no;
true ->
RecvSet = {recv_set,{f,L}},
{yes,reverse(Acc, [RecvSet,Lbl,Loop|Is]),L}
end;
- [] ->
+ true ->
no
end;
opt_recv([I|Is], D, R0, L0, Acc) ->
@@ -226,9 +226,9 @@ opt_update_regs_bl([{set,Ds,_,_}|Is], Regs0) ->
opt_update_regs_bl(Is, Regs);
opt_update_regs_bl([], Regs) -> Regs.
-%% opt_ref_used([Instruction], RefRegister, FailLabel, LabelIndex) -> true|false
+%% opt_ref_used([Instruction], RefRegs, FailLabel, LabelIndex) -> true|false
%% Return 'true' if it is certain that only messages that contain the same
-%% reference as in RefRegister can be matched out. Otherwise return 'false'.
+%% reference as in RefRegs can be matched out. Otherwise return 'false'.
%%
%% Basically, we follow all possible paths through the receive statement.
%% If all paths are safe, we return 'true'.
@@ -236,7 +236,7 @@ opt_update_regs_bl([], Regs) -> Regs.
%% A branch to FailLabel is safe, because it exits the receive statement
%% and no further message may be matched out.
%%
-%% If a path hits an comparision between RefRegister and part of the message,
+%% If a path hits an comparision between RefRegs and part of the message,
%% that path is safe (any messages that may be matched further down the
%% path is guaranteed to contain the reference).
%%
@@ -245,11 +245,11 @@ opt_update_regs_bl([], Regs) -> Regs.
%% we hit an unrecognized instruction, we also give up and return
%% 'false' (the optimization may be unsafe).
-opt_ref_used(Is, RefReg, Fail, D) ->
+opt_ref_used(Is, RefRegs, Fail, D) ->
Done = gb_sets:singleton(Fail),
Regs = regs_init_x0(),
try
- _ = opt_ref_used_1(Is, RefReg, D, Done, Regs),
+ _ = opt_ref_used_1(Is, RefRegs, D, Done, Regs),
true
catch
throw:not_used ->
@@ -258,37 +258,39 @@ opt_ref_used(Is, RefReg, Fail, D) ->
%% This functions only returns if all paths through the receive
%% statement are safe, and throws an 'not_used' term otherwise.
-opt_ref_used_1([{block,Bl}|Is], RefReg, D, Done, Regs0) ->
+opt_ref_used_1([{block,Bl}|Is], RefRegs, D, Done, Regs0) ->
Regs = opt_ref_used_bl(Bl, Regs0),
- opt_ref_used_1(Is, RefReg, D, Done, Regs);
-opt_ref_used_1([{test,is_eq_exact,{f,Fail},Args}|Is], RefReg, D, Done0, Regs) ->
- Done = opt_ref_used_at(Fail, RefReg, D, Done0, Regs),
- case is_ref_msg_comparison(Args, RefReg, Regs) of
+ opt_ref_used_1(Is, RefRegs, D, Done, Regs);
+opt_ref_used_1([{test,is_eq_exact,{f,Fail},Args}|Is],
+ RefRegs, D, Done0, Regs) ->
+ Done = opt_ref_used_at(Fail, RefRegs, D, Done0, Regs),
+ case is_ref_msg_comparison(Args, RefRegs, Regs) of
false ->
- opt_ref_used_1(Is, RefReg, D, Done, Regs);
+ opt_ref_used_1(Is, RefRegs, D, Done, Regs);
true ->
%% The instructions that follow (Is) can only be executed
- %% if the message contains the same reference as in RefReg.
+ %% if the message contains the same reference as in RefRegs.
Done
end;
-opt_ref_used_1([{test,is_ne_exact,{f,Fail},Args}|Is], RefReg, D, Done0, Regs) ->
- Done = opt_ref_used_1(Is, RefReg, D, Done0, Regs),
- case is_ref_msg_comparison(Args, RefReg, Regs) of
+opt_ref_used_1([{test,is_ne_exact,{f,Fail},Args}|Is],
+ RefRegs, D, Done0, Regs) ->
+ Done = opt_ref_used_1(Is, RefRegs, D, Done0, Regs),
+ case is_ref_msg_comparison(Args, RefRegs, Regs) of
false ->
- opt_ref_used_at(Fail, RefReg, D, Done, Regs);
+ opt_ref_used_at(Fail, RefRegs, D, Done, Regs);
true ->
Done
end;
-opt_ref_used_1([{test,_,{f,Fail},_}|Is], RefReg, D, Done0, Regs) ->
- Done = opt_ref_used_at(Fail, RefReg, D, Done0, Regs),
- opt_ref_used_1(Is, RefReg, D, Done, Regs);
-opt_ref_used_1([{select,_,_,{f,Fail},List}|_], RefReg, D, Done, Regs) ->
+opt_ref_used_1([{test,_,{f,Fail},_}|Is], RefRegs, D, Done0, Regs) ->
+ Done = opt_ref_used_at(Fail, RefRegs, D, Done0, Regs),
+ opt_ref_used_1(Is, RefRegs, D, Done, Regs);
+opt_ref_used_1([{select,_,_,{f,Fail},List}|_], RefRegs, D, Done, Regs) ->
Lbls = [F || {f,F} <- List] ++ [Fail],
- opt_ref_used_in_all(Lbls, RefReg, D, Done, Regs);
-opt_ref_used_1([{label,Lbl}|Is], RefReg, D, Done, Regs) ->
+ opt_ref_used_in_all(Lbls, RefRegs, D, Done, Regs);
+opt_ref_used_1([{label,Lbl}|Is], RefRegs, D, Done, Regs) ->
case gb_sets:is_member(Lbl, Done) of
true -> Done;
- false -> opt_ref_used_1(Is, RefReg, D, Done, Regs)
+ false -> opt_ref_used_1(Is, RefRegs, D, Done, Regs)
end;
opt_ref_used_1([{loop_rec_end,_}|_], _, _, Done, _) ->
Done;
@@ -296,27 +298,25 @@ opt_ref_used_1([_I|_], _RefReg, _D, _Done, _Regs) ->
%% The optimization may be unsafe.
throw(not_used).
-%% is_ref_msg_comparison(Args, RefReg, RegisterSet) -> true|false.
+%% is_ref_msg_comparison(Args, RefRegs, RegisterSet) -> true|false.
%% Return 'true' if Args denotes a comparison between the
%% reference and message or part of the message.
-is_ref_msg_comparison([R,RefReg], RefReg, Regs) ->
- regs_is_member(R, Regs);
-is_ref_msg_comparison([RefReg,R], RefReg, Regs) ->
- regs_is_member(R, Regs);
-is_ref_msg_comparison([_,_], _, _) -> false.
-
-opt_ref_used_in_all([L|Ls], RefReg, D, Done0, Regs) ->
- Done = opt_ref_used_at(L, RefReg, D, Done0, Regs),
- opt_ref_used_in_all(Ls, RefReg, D, Done, Regs);
+is_ref_msg_comparison([R1,R2], RefRegs, Regs) ->
+ (regs_is_member(R2, RefRegs) andalso regs_is_member(R1, Regs)) orelse
+ (regs_is_member(R1, RefRegs) andalso regs_is_member(R2, Regs)).
+
+opt_ref_used_in_all([L|Ls], RefRegs, D, Done0, Regs) ->
+ Done = opt_ref_used_at(L, RefRegs, D, Done0, Regs),
+ opt_ref_used_in_all(Ls, RefRegs, D, Done, Regs);
opt_ref_used_in_all([], _, _, Done, _) -> Done.
-opt_ref_used_at(Fail, RefReg, D, Done0, Regs) ->
+opt_ref_used_at(Fail, RefRegs, D, Done0, Regs) ->
case gb_sets:is_member(Fail, Done0) of
true ->
Done0;
false ->
Is = beam_utils:code_at(Fail, D),
- Done = opt_ref_used_1(Is, RefReg, D, Done0, Regs),
+ Done = opt_ref_used_1(Is, RefRegs, D, Done0, Regs),
gb_sets:add(Fail, Done)
end.
@@ -408,15 +408,3 @@ regs_all_members([], _) -> true.
regs_is_member({x,N}, {Regs,_}) -> Regs band (1 bsl N) =/= 0;
regs_is_member({y,N}, {_,Regs}) -> Regs band (1 bsl N) =/= 0;
regs_is_member(_, _) -> false.
-
-%% regs_to_list(RegisterSet) -> [Register]
-%% Convert the register set to an explicit list of registers.
-regs_to_list({Xregs,Yregs}) ->
- regs_to_list_1(Xregs, 0, x, regs_to_list_1(Yregs, 0, y, [])).
-
-regs_to_list_1(0, _, _, Acc) ->
- Acc;
-regs_to_list_1(Regs, N, Tag, Acc) when (Regs band 1) =:= 1 ->
- regs_to_list_1(Regs bsr 1, N+1, Tag, [{Tag,N}|Acc]);
-regs_to_list_1(Regs, N, Tag, Acc) ->
- regs_to_list_1(Regs bsr 1, N+1, Tag, Acc).
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-01 21:33:17 +0000