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-rw-r--r--lib/compiler/src/sys_core_fold.erl50
1 files changed, 15 insertions, 35 deletions
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl
index c83dd3c0a1..7d1819ea15 100644
--- a/lib/compiler/src/sys_core_fold.erl
+++ b/lib/compiler/src/sys_core_fold.erl
@@ -2272,31 +2272,7 @@ opt_simple_let_1(#c_let{vars=Vs0,body=B0}=Let, Arg0, Ctxt, Sub0) ->
Arg = core_lib:make_values(Args),
opt_simple_let_2(Let, Vs, Arg, B, Ctxt, Sub1).
-opt_simple_let_2(Let0, Vs0, Arg0, Body0, effect, Sub) ->
- case {Vs0,Arg0,Body0} of
- {[],#c_values{es=[]},Body} ->
- %% No variables left (because of substitutions).
- Body;
- {[_|_],Arg,#c_literal{}} ->
- %% The body is a literal. That means that we can ignore
- %% it and that the return value is Arg revisited in
- %% effect context.
- body(Arg, effect, sub_new_preserve_types(Sub));
- {Vs,Arg,Body} ->
- %% Since we are in effect context, there is a chance
- %% that the body no longer references the variables.
- %% In that case we can construct a sequence and visit
- %% that in effect context:
- %% let <Var> = Arg in BodyWithoutVar ==> seq Arg BodyWithoutVar
- case is_any_var_used(Vs, Body) of
- false ->
- expr(#c_seq{arg=Arg,body=Body}, effect, sub_new_preserve_types(Sub));
- true ->
- Let = Let0#c_let{vars=Vs,arg=Arg,body=Body},
- opt_case_in_let_arg(opt_case_in_let(Let, Sub), effect, Sub)
- end
- end;
-opt_simple_let_2(Let0, Vs0, Arg0, Body, value, Sub) ->
+opt_simple_let_2(Let0, Vs0, Arg0, Body, Ctxt, Sub) ->
case {Vs0,Arg0,Body} of
{[#c_var{name=N1}],Arg,#c_var{name=N2}} ->
case N1 =:= N2 of
@@ -2305,26 +2281,30 @@ opt_simple_let_2(Let0, Vs0, Arg0, Body, value, Sub) ->
Arg;
false ->
%% let <Var> = Arg in <OtherVar> ==> seq Arg OtherVar
- expr(#c_seq{arg=Arg,body=Body}, value, sub_new_preserve_types(Sub))
+ expr(#c_seq{arg=Arg,body=Body}, Ctxt,
+ sub_new_preserve_types(Sub))
end;
{[],#c_values{es=[]},_} ->
%% No variables left.
Body;
{_,Arg,#c_literal{}} ->
- %% The variable is not used in the body. The argument
- %% can be evaluated in effect context to simplify it.
- expr(#c_seq{arg=Arg,body=Body}, value, sub_new_preserve_types(Sub));
- {Vs,Arg,Body} ->
- %% If none of the variables are used in the body, we can rewrite the
+ %% Since the variable is not used in the body, we can rewrite the
%% let to a sequence:
- %% let <Var> = Arg in BodyWithoutVar ==> seq Arg BodyWithoutVar
+ %% let <Var> = Arg in Literal ==> seq Arg Literal
+ expr(#c_seq{arg=Arg,body=Body}, Ctxt, sub_new_preserve_types(Sub));
+ {Vs,Arg,Body} ->
+ %% If none of the variables are used in the body, we can
+ %% rewrite the let to a sequence:
+ %% let <Var> = Arg in BodyWithoutVar ==>
+ %% seq Arg BodyWithoutVar
case is_any_var_used(Vs, Body) of
false ->
- expr(#c_seq{arg=Arg,body=Body}, value,
+ expr(#c_seq{arg=Arg,body=Body}, Ctxt,
sub_new_preserve_types(Sub));
true ->
- Let = Let0#c_let{vars=Vs,arg=Arg,body=Body},
- opt_case_in_let_arg(opt_case_in_let(Let, Sub), value, Sub)
+ Let1 = Let0#c_let{vars=Vs,arg=Arg,body=Body},
+ Let2 = opt_case_in_let(Let1, Sub),
+ opt_case_in_let_arg(Let2, Ctxt, Sub)
end
end.