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authorBjörn Gustavsson <[email protected]>2019-02-28 16:52:55 +0100
committerBjörn Gustavsson <[email protected]>2019-03-01 12:55:20 +0100
commit7095bf55f41f3f843da147a3deeea34c5ce2db7f (patch)
tree720f790ed857ab2183f6b15839fce178991997df /lib/compiler/src
parent7dce10bc84e0e8f88233cf5d8e659d5e2f58496c (diff)
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Do some minor optimizations of compilation times
The general complexity of the shortcut sub pass of `beam_ssa_dead` is quadratic, but those optimizations will reduce the constant factor somewhat.
Diffstat (limited to 'lib/compiler/src')
-rw-r--r--lib/compiler/src/beam_ssa_dead.erl37
1 files changed, 26 insertions, 11 deletions
diff --git a/lib/compiler/src/beam_ssa_dead.erl b/lib/compiler/src/beam_ssa_dead.erl
index dc0381f105..c573c869cf 100644
--- a/lib/compiler/src/beam_ssa_dead.erl
+++ b/lib/compiler/src/beam_ssa_dead.erl
@@ -59,7 +59,7 @@ opt(Linear) ->
Blocks0 = maps:from_list(Linear),
St0 = #st{bs=Blocks0,us=Used,skippable=Skippable},
St = shortcut_opt(St0),
- #st{bs=Blocks} = combine_eqs(St),
+ #st{bs=Blocks} = combine_eqs(St#st{us=#{}}),
beam_ssa:linearize(Blocks).
%%%
@@ -391,7 +391,7 @@ is_forbidden(L, St) ->
eval_is([#b_set{op=phi,dst=Dst,args=Args}|Is], Bs0, St) ->
From = map_get(from, Bs0),
- [Val] = [Val || {Val,Pred} <- Args, Pred =:= From],
+ Val = get_phi_arg(Args, From),
Bs = bind_var(Dst, Val, Bs0),
eval_is(Is, Bs, St);
eval_is([#b_set{op={bif,_},dst=Dst}=I0|Is], Bs, St) ->
@@ -424,6 +424,9 @@ eval_is([#b_set{}=I|Is], Bs, St) ->
end;
eval_is([], Bs, _St) -> Bs.
+get_phi_arg([{Val,From}|_], From) -> Val;
+get_phi_arg([_|As], From) -> get_phi_arg(As, From).
+
eval_terminator(#b_br{bool=#b_var{}=Bool}=Br, Bs, _St) ->
Val = get_value(Bool, Bs),
beam_ssa:normalize(Br#b_br{bool=Val});
@@ -492,20 +495,31 @@ eval_bif(#b_set{op={bif,Bif},args=Args}, St) ->
false ->
none;
true ->
- case [Lit || #b_literal{val=Lit} <- Args] of
- LitArgs when length(LitArgs) =:= Arity ->
+ case get_lit_args(Args) of
+ none ->
+ %% Not literal arguments. Try to evaluate
+ %% it based on a previous relational operator.
+ eval_rel_op({bif,Bif}, Args, St);
+ LitArgs ->
try apply(erlang, Bif, LitArgs) of
Val -> #b_literal{val=Val}
catch
error:_ -> none
- end;
- _ ->
- %% Not literal arguments. Try to evaluate
- %% it based on a previous relational operator.
- eval_rel_op({bif,Bif}, Args, St)
+ end
end
end.
+get_lit_args([#b_literal{val=Lit1}]) ->
+ [Lit1];
+get_lit_args([#b_literal{val=Lit1},
+ #b_literal{val=Lit2}]) ->
+ [Lit1,Lit2];
+get_lit_args([#b_literal{val=Lit1},
+ #b_literal{val=Lit2},
+ #b_literal{val=Lit3}]) ->
+ [Lit1,Lit2,Lit3];
+get_lit_args(_) -> none.
+
%%%
%%% Handling of relational operators.
%%%
@@ -1041,11 +1055,12 @@ used_vars_is([], Used) ->
sub(#b_set{args=Args}=I, Sub) ->
I#b_set{args=[sub_arg(A, Sub) || A <- Args]}.
-sub_arg(Old, Sub) ->
+sub_arg(#b_var{}=Old, Sub) ->
case Sub of
#{Old:=New} -> New;
#{} -> Old
- end.
+ end;
+sub_arg(Old, _Sub) -> Old.
rel2fam(S0) ->
S1 = sofs:relation(S0),