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authorBjörn Gustavsson <[email protected]>2019-01-30 11:29:08 +0100
committerGitHub <[email protected]>2019-01-30 11:29:08 +0100
commit135f98f4481e57f82c03c74a41ebde649af40f04 (patch)
tree1405d186ab931e7c936f01610a03aadefb8f9ae2 /lib/compiler/src
parent5b0f748c15d6dcdae4cb18c45b9fca92e45a5cc6 (diff)
parent86f82183855d6b21912e0e125b096a28a52bbcf6 (diff)
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Merge pull request #2115 from bjorng/bjorn/compiler/opt-function_clause
Enhance optimization of function_clause exceptions
Diffstat (limited to 'lib/compiler/src')
-rw-r--r--lib/compiler/src/beam_except.erl51
1 files changed, 32 insertions, 19 deletions
diff --git a/lib/compiler/src/beam_except.erl b/lib/compiler/src/beam_except.erl
index 26b193a35b..254a716b81 100644
--- a/lib/compiler/src/beam_except.erl
+++ b/lib/compiler/src/beam_except.erl
@@ -31,7 +31,7 @@
%%% erlang:error(function_clause, Args) => jump FuncInfoLabel
%%%
--import(lists, [reverse/1,seq/2,splitwith/2]).
+-import(lists, [reverse/1,reverse/2,seq/2,splitwith/2]).
-spec module(beam_utils:module_code(), [compile:option()]) ->
{'ok',beam_utils:module_code()}.
@@ -53,7 +53,7 @@ function({function,Name,Arity,CLabel,Is0}) ->
-record(st,
{lbl :: beam_asm:label(), %func_info label
loc :: [_], %location for func_info
- arity :: arity() %arity for function
+ arity :: arity() %arity for function
}).
function_1(Is0) ->
@@ -150,10 +150,15 @@ dig_out_fc(Arity, Is0) ->
(_) -> true
end, Is0),
{Regs,Acc} = dig_out_fc_1(reverse(Is), Regs0, Acc0),
- case is_fc(Arity, Regs) of
- true ->
- {yes,function_clause,Acc};
- false ->
+ case Regs of
+ #{{x,0}:={atom,function_clause},{x,1}:=Args} ->
+ case moves_from_stack(Args, 0, []) of
+ {Moves,Arity} ->
+ {yes,function_clause,reverse(Moves, Acc)};
+ {_,_} ->
+ no
+ end;
+ #{} ->
no
end.
@@ -187,22 +192,30 @@ dig_out_fc_block([], Regs) -> Regs.
prune_xregs(Live, Regs) ->
maps:filter(fun({x,X}, _) -> X < Live end, Regs).
-is_fc(Arity, Regs) ->
- case Regs of
- #{{x,0}:={atom,function_clause},{x,1}:=Args} ->
- is_fc_1(Args, 0) =:= Arity;
- #{} ->
- false
- end.
-
-is_fc_1({cons,{arg,I},T}, I) ->
- is_fc_1(T, I+1);
-is_fc_1(nil, I) ->
- I;
-is_fc_1(_, _) -> -1.
+moves_from_stack({cons,{arg,N},_}, I, _Acc) when N =/= I ->
+ %% Wrong argument. Give up.
+ {[],-1};
+moves_from_stack({cons,H,T}, I, Acc) ->
+ case H of
+ {arg,I} ->
+ moves_from_stack(T, I+1, Acc);
+ _ ->
+ moves_from_stack(T, I+1, [{move,H,{x,I}}|Acc])
+ end;
+moves_from_stack(nil, I, Acc) ->
+ {reverse(Acc),I};
+moves_from_stack({literal,[H|T]}, I, Acc) ->
+ Cons = {cons,tag_literal(H),tag_literal(T)},
+ moves_from_stack(Cons, I, Acc).
get_reg(R, Regs) ->
case Regs of
#{R:=Val} -> Val;
#{} -> R
end.
+
+tag_literal([]) -> nil;
+tag_literal(T) when is_atom(T) -> {atom,T};
+tag_literal(T) when is_float(T) -> {float,T};
+tag_literal(T) when is_integer(T) -> {integer,T};
+tag_literal(T) -> {literal,T}.