aboutsummaryrefslogtreecommitdiffstats
path: root/lib/compiler
diff options
context:
space:
mode:
authorBjörn Gustavsson <[email protected]>2019-02-26 13:31:16 +0100
committerBjörn Gustavsson <[email protected]>2019-02-28 12:18:23 +0100
commit72b503485b0d029f615c80c3e64680419cd690d9 (patch)
tree6df81eca7b82eb45f863eb3b809ad7fc9fb78d80 /lib/compiler
parent300c64460d6ea19eb34f9d345a7e7770db7fa538 (diff)
downloadotp-72b503485b0d029f615c80c3e64680419cd690d9.tar.gz
otp-72b503485b0d029f615c80c3e64680419cd690d9.tar.bz2
otp-72b503485b0d029f615c80c3e64680419cd690d9.zip
beam_ssa_opt: Use is_tagged_tuple more
Consider this code: foo(X) -> case X of {ok,A} -> A; error -> X end. The `is_tagged_tuple` instruction would not be used because not all instructions in the tuple matching sequence had the same failure label: function t:foo(_0) { 0: @ssa_bool:7 = bif:is_tuple _0 br @ssa_bool:7, label 8, label 4 8: @ssa_arity = bif:tuple_size _0 @ssa_bool:9 = bif:'=:=' @ssa_arity, literal 2 br @ssa_bool:9, label 6, label 3 6: _4 = get_tuple_element _0, literal 0 @ssa_bool = bif:'=:=' _4, literal ok br @ssa_bool, label 5, label 3 5: _3 = get_tuple_element _0, literal 1 ret _3 4: @ssa_bool:11 = bif:'=:=' _0, literal error br @ssa_bool:11, label 10, label 3 10: ret _0 3: _2 = put_tuple literal case_clause, _0 %% t.erl:5 @ssa_ret:12 = call remote (literal erlang):(literal error)/1, _2 ret @ssa_ret:12 } Enhance the ssa_opt_record optimization to use `is_tagged_tuple` even if all failure labels are not the same: function t:foo(_0) { 0: @ssa_bool:7 = bif:is_tuple _0 br @ssa_bool:7, label 8, label 4 8: @ssa_bool:9 = is_tagged_tuple _0, literal 2, literal ok br @ssa_bool:9, label 6, label 3 6: _3 = get_tuple_element _0, literal 1 ret _3 4: @ssa_bool:11 = bif:'=:=' _0, literal error br @ssa_bool:11, label 10, label 3 10: ret _0 3: _2 = put_tuple literal case_clause, _0 %% t.erl:5 @ssa_ret:12 = call remote (literal erlang):(literal error)/1, _2 ret @ssa_ret:12 } The tuple test will be repeated, but since four instructions are replaced by two instructions, the code will still be faster and smaller.
Diffstat (limited to 'lib/compiler')
-rw-r--r--lib/compiler/src/beam_ssa_opt.erl51
1 files changed, 30 insertions, 21 deletions
diff --git a/lib/compiler/src/beam_ssa_opt.erl b/lib/compiler/src/beam_ssa_opt.erl
index ff9d562d67..bcf55f3fda 100644
--- a/lib/compiler/src/beam_ssa_opt.erl
+++ b/lib/compiler/src/beam_ssa_opt.erl
@@ -683,6 +683,14 @@ record_opt_is([#b_set{op={bif,is_tuple},dst=Bool,args=[Tuple]}=Set],
no ->
[Set]
end;
+record_opt_is([I|Is]=Is0, #b_br{bool=Bool}=Last, Blocks) ->
+ case is_tagged_tuple_1(Is0, Last, Blocks) of
+ {yes,_Fail,Tuple,Arity,Tag} ->
+ Args = [Tuple,Arity,Tag],
+ [I#b_set{op=is_tagged_tuple,dst=Bool,args=Args}];
+ no ->
+ [I|record_opt_is(Is, Last, Blocks)]
+ end;
record_opt_is([I|Is], Last, Blocks) ->
[I|record_opt_is(Is, Last, Blocks)];
record_opt_is([], _Last, _Blocks) -> [].
@@ -690,29 +698,30 @@ record_opt_is([], _Last, _Blocks) -> [].
is_tagged_tuple(#b_var{}=Tuple, Bool,
#b_br{bool=Bool,succ=Succ,fail=Fail},
Blocks) ->
- SuccBlk = map_get(Succ, Blocks),
- is_tagged_tuple_1(SuccBlk, Tuple, Fail, Blocks);
+ #b_blk{is=Is,last=Last} = map_get(Succ, Blocks),
+ case is_tagged_tuple_1(Is, Last, Blocks) of
+ {yes,Fail,Tuple,Arity,Tag} ->
+ {yes,Arity,Tag};
+ _ ->
+ no
+ end;
is_tagged_tuple(_, _, _, _) -> no.
-is_tagged_tuple_1(#b_blk{is=Is,last=Last}, Tuple, Fail, Blocks) ->
- case Is of
- [#b_set{op={bif,tuple_size},dst=ArityVar,
- args=[#b_var{}=Tuple]},
- #b_set{op={bif,'=:='},
- dst=Bool,
- args=[ArityVar, #b_literal{val=ArityVal}=Arity]}]
- when is_integer(ArityVal) ->
- case Last of
- #b_br{bool=Bool,succ=Succ,fail=Fail} ->
- SuccBlk = map_get(Succ, Blocks),
- case is_tagged_tuple_2(SuccBlk, Tuple, Fail) of
- no ->
- no;
- {yes,Tag} ->
- {yes,Arity,Tag}
- end;
- _ ->
- no
+is_tagged_tuple_1(Is, Last, Blocks) ->
+ case {Is,Last} of
+ {[#b_set{op={bif,tuple_size},dst=ArityVar,
+ args=[#b_var{}=Tuple]},
+ #b_set{op={bif,'=:='},
+ dst=Bool,
+ args=[ArityVar, #b_literal{val=ArityVal}=Arity]}],
+ #b_br{bool=Bool,succ=Succ,fail=Fail}}
+ when is_integer(ArityVal) ->
+ SuccBlk = map_get(Succ, Blocks),
+ case is_tagged_tuple_2(SuccBlk, Tuple, Fail) of
+ no ->
+ no;
+ {yes,Tag} ->
+ {yes,Fail,Tuple,Arity,Tag}
end;
_ ->
no