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-rw-r--r--lib/compiler/src/beam_utils.erl22
1 files changed, 16 insertions, 6 deletions
diff --git a/lib/compiler/src/beam_utils.erl b/lib/compiler/src/beam_utils.erl
index 8ca368c167..3249024854 100644
--- a/lib/compiler/src/beam_utils.erl
+++ b/lib/compiler/src/beam_utils.erl
@@ -26,6 +26,8 @@
code_at/2,bif_to_test/3,is_pure_test/1,
live_opt/1,delete_live_annos/1,combine_heap_needs/2]).
+-export([join_even/2,split_even/1]).
+
-import(lists, [member/2,sort/1,reverse/1,splitwith/2]).
-record(live,
@@ -185,7 +187,7 @@ is_pure_test({test,is_lt,_,[_,_]}) -> true;
is_pure_test({test,is_nil,_,[_]}) -> true;
is_pure_test({test,is_nonempty_list,_,[_]}) -> true;
is_pure_test({test,test_arity,_,[_,_]}) -> true;
-is_pure_test({test,has_map_fields,_,[_,{list,_}]}) -> true;
+is_pure_test({test,has_map_fields,_,[_|_]}) -> true;
is_pure_test({test,Op,_,Ops}) ->
erl_internal:new_type_test(Op, length(Ops)).
@@ -756,13 +758,9 @@ live_opt([{line,_}=I|Is], Regs, D, Acc) ->
live_opt(Is, Regs, D, [I|Acc]);
%% The following instructions can occur if the "compilation" has been
-%% started from a .S file using the 'asm' option.
+%% started from a .S file using the 'from_asm' option.
live_opt([{trim,_,_}=I|Is], Regs, D, Acc) ->
live_opt(Is, Regs, D, [I|Acc]);
-live_opt([{allocate,_,Live}=I|Is], _, D, Acc) ->
- live_opt(Is, live_call(Live), D, [I|Acc]);
-live_opt([{allocate_heap,_,_,Live}=I|Is], _, D, Acc) ->
- live_opt(Is, live_call(Live), D, [I|Acc]);
live_opt([{'%',_}=I|Is], Regs, D, Acc) ->
live_opt(Is, Regs, D, [I|Acc]);
live_opt([{recv_set,_}=I|Is], Regs, D, Acc) ->
@@ -832,3 +830,15 @@ x_live([_|Rs], Regs) -> x_live(Rs, Regs);
x_live([], Regs) -> Regs.
is_live(X, Regs) -> ((Regs bsr X) band 1) =:= 1.
+
+%% split_even/1
+%% [1,2,3,4,5,6] -> {[1,3,5],[2,4,6]}
+split_even(Rs) -> split_even(Rs,[],[]).
+split_even([],Ss,Ds) -> {reverse(Ss),reverse(Ds)};
+split_even([S,D|Rs],Ss,Ds) ->
+ split_even(Rs,[S|Ss],[D|Ds]).
+
+%% join_even/1
+%% {[1,3,5],[2,4,6]} -> [1,2,3,4,5,6]
+join_even([],[]) -> [];
+join_even([S|Ss],[D|Ds]) -> [S,D|join_even(Ss,Ds)].