File 2867-Remove-the-beam_peep-pass.patch of Package erlang
From 8e4c66243cbb724c10c975a4ba9fd7b0bd81fc5d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Fri, 20 Aug 2021 07:19:57 +0200
Subject: [PATCH 7/7] Remove the beam_peep pass
All optimizations in `beam_peep` have either been reimplemented as
optimizations on SSA code or moved to other passes.
---
lib/compiler/src/Makefile | 1 -
lib/compiler/src/beam_clean.erl | 4 -
lib/compiler/src/beam_peep.erl | 223 ----------------------------
lib/compiler/src/compile.erl | 3 -
lib/compiler/src/compiler.app.src | 1 -
lib/compiler/test/compile_SUITE.erl | 1 -
lib/compiler/test/misc_SUITE.erl | 11 --
7 files changed, 244 deletions(-)
delete mode 100644 lib/compiler/src/beam_peep.erl
diff --git a/lib/compiler/src/Makefile b/lib/compiler/src/Makefile
index f195e16dc6..24414fef77 100644
--- a/lib/compiler/src/Makefile
+++ b/lib/compiler/src/Makefile
@@ -58,7 +58,6 @@ MODULES = \
beam_jump \
beam_listing \
beam_opcodes \
- beam_peep \
beam_ssa \
beam_ssa_bc_size \
beam_ssa_bool \
diff --git a/lib/compiler/src/beam_clean.erl b/lib/compiler/src/beam_clean.erl
index 643cc1c386..e771818d10 100644
--- a/lib/compiler/src/beam_clean.erl
+++ b/lib/compiler/src/beam_clean.erl
@@ -22,7 +22,6 @@
-module(beam_clean).
-export([module/2]).
--export([clean_labels/1]).
-spec module(beam_utils:module_code(), [compile:option()]) ->
{'ok',beam_utils:module_code()}.
@@ -98,9 +97,6 @@ add_to_work_list(F, {Fs,Used}=Sets) ->
lc :: non_neg_integer() %Label counter
}).
--spec clean_labels([beam_utils:instruction()]) ->
- {[beam_utils:instruction()],pos_integer()}.
-
clean_labels(Fs0) ->
St0 = #st{lmap=[],entry=1,lc=1},
{Fs1,#st{lmap=Lmap0,lc=Lc}} = function_renumber(Fs0, St0, []),
diff --git a/lib/compiler/src/beam_peep.erl b/lib/compiler/src/beam_peep.erl
deleted file mode 100644
index da59aea2bd..0000000000
--- a/lib/compiler/src/beam_peep.erl
+++ /dev/null
@@ -1,223 +0,0 @@
-%%
-%% %CopyrightBegin%
-%%
-%% Copyright Ericsson AB 2008-2020. All Rights Reserved.
-%%
-%% Licensed under the Apache License, Version 2.0 (the "License");
-%% you may not use this file except in compliance with the License.
-%% You may obtain a copy of the License at
-%%
-%% http://www.apache.org/licenses/LICENSE-2.0
-%%
-%% Unless required by applicable law or agreed to in writing, software
-%% distributed under the License is distributed on an "AS IS" BASIS,
-%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-%% See the License for the specific language governing permissions and
-%% limitations under the License.
-%%
-%% %CopyrightEnd%
-%%
-
--module(beam_peep).
-
--export([module/2]).
-
--import(lists, [reverse/1,member/2,usort/1]).
-
--spec module(beam_utils:module_code(), [compile:option()]) ->
- {'ok',beam_utils:module_code()}.
-
-module({Mod,Exp,Attr,Fs0,_}, _Opts) ->
- %% First coalesce adjacent labels.
- {Fs1,Lc} = beam_clean:clean_labels(Fs0),
-
- %% Do the peep hole optimizations.
- Fs = [function(F) || F <- Fs1],
- {ok,{Mod,Exp,Attr,Fs,Lc}}.
-
-function({function,Name,Arity,CLabel,Is0}) ->
- try
- Is1 = peep(Is0),
- Is = beam_jump:remove_unused_labels(Is1),
- {function,Name,Arity,CLabel,Is}
- catch
- Class:Error:Stack ->
- io:fwrite("Function: ~w/~w\n", [Name,Arity]),
- erlang:raise(Class, Error, Stack)
- end.
-
-
-%% Peep-hole optimizations suitable to perform when most of the
-%% optimations passes have been run.
-%%
-%% (1) In a sequence of tests, we can remove any test instruction
-%% that has been previously seen, because it will certainly
-%% succeed.
-%%
-%% For instance, in the following code sequence
-%%
-%% is_eq_exact _Fail SomeRegister SomeLiteral
-%% is_ne_exact _Fail SomeOtherRegister SomeOtherLiteral
-%% is_eq_exact _Fail SomeRegister SomeLiteral
-%% is_ne_exact _Fail SomeOtherRegister StillSomeOtherLiteral
-%%
-%% the third test is redundant. The code sequence will be produced
-%% by a combination of semicolon and command guards, such as
-%%
-%% InEncoding =:= latin1, OutEncoding =:= unicode;
-%% InEncoding =:= latin1, OutEncoding =:= utf8 ->
-%%
-
-peep(Is) ->
- peep(Is, gb_sets:empty(), []).
-
-peep([{bif,tuple_size,_,[_]=Ops,Dst}=I|Is], SeenTests0, Acc) ->
- %% Pretend that we have seen {test,is_tuple,_,Ops}.
- SeenTests1 = gb_sets:add({is_tuple,Ops}, SeenTests0),
- %% Kill all remembered tests that depend on the destination register.
- SeenTests = kill_seen(Dst, SeenTests1),
- peep(Is, SeenTests, [I|Acc]);
-peep([{bif,map_get,_,[Key,Map],Dst}=I|Is], SeenTests0, Acc) ->
- %% Pretend that we have seen {test,has_map_fields,_,[Map,Key]}
- SeenTests1 = gb_sets:add({has_map_fields,[Map,Key]}, SeenTests0),
- %% Kill all remembered tests that depend on the destination register.
- SeenTests = kill_seen(Dst, SeenTests1),
- peep(Is, SeenTests, [I|Acc]);
-peep([{bif,_,_,_,Dst}=I|Is], SeenTests0, Acc) ->
- %% Kill all remembered tests that depend on the destination register.
- SeenTests = kill_seen(Dst, SeenTests0),
- peep(Is, SeenTests, [I|Acc]);
-peep([{gc_bif,_,_,_,_,Dst}=I|Is], SeenTests0, Acc) ->
- %% Kill all remembered tests that depend on the destination register.
- SeenTests = kill_seen(Dst, SeenTests0),
- peep(Is, SeenTests, [I|Acc]);
-peep([{jump,{f,L}},{label,L}=I|Is], _, Acc) ->
- %% Sometimes beam_jump has missed this optimization.
- peep(Is, gb_sets:empty(), [I|Acc]);
-peep([{select,select_val,R,F,Vls0}|Is], SeenTests0, Acc0) ->
- case prune_redundant_values(Vls0, F) of
- [] ->
- %% No values left. Must convert to plain jump.
- I = {jump,F},
- peep([I|Is], gb_sets:empty(), Acc0);
- [{atom,_}=Value,Lbl] ->
- %% Single value left. Convert to regular test.
- Is1 = [{test,is_eq_exact,F,[R,Value]},{jump,Lbl}|Is],
- peep(Is1, SeenTests0, Acc0);
- [{integer,_}=Value,Lbl] ->
- %% Single value left. Convert to regular test.
- Is1 = [{test,is_eq_exact,F,[R,Value]},{jump,Lbl}|Is],
- peep(Is1, SeenTests0, Acc0);
- [{atom,B1},Lbl,{atom,B2},Lbl] when B1 =:= not B2 ->
- %% Replace with is_boolean test.
- Is1 = [{test,is_boolean,F,[R]},{jump,Lbl}|Is],
- peep(Is1, SeenTests0, Acc0);
- [_|_]=Vls ->
- I = {select,select_val,R,F,Vls},
- peep(Is, gb_sets:empty(), [I|Acc0])
- end;
-peep([{get_map_elements,Fail,Src,List}=I|Is], _SeenTests, Acc0) ->
- SeenTests = gb_sets:empty(),
- case simplify_get_map_elements(Fail, Src, List, Acc0) of
- {ok,Acc} ->
- peep(Is, SeenTests, Acc);
- error ->
- peep(Is, SeenTests, [I|Acc0])
- end;
-peep([{test,has_map_fields,Fail,Ops}=I|Is], SeenTests, Acc0) ->
- case simplify_has_map_fields(Fail, Ops, Acc0) of
- {ok,Acc} ->
- peep(Is, SeenTests, Acc);
- error ->
- peep(Is, SeenTests, [I|Acc0])
- end;
-peep([{test,Op,_,Ops}=I|Is], SeenTests0, Acc) ->
- case beam_utils:is_pure_test(I) of
- false ->
- %% Bit syntax matching, which may modify registers and/or
- %% match state. Clear all information about tests that
- %% has succeeded.
- peep(Is, gb_sets:empty(), [I|Acc]);
- true ->
- case is_test_redundant(Op, Ops, SeenTests0) of
- true ->
- %% This test or a similar test has already succeeded and
- %% is therefore redundant.
- peep(Is, SeenTests0, Acc);
- false ->
- %% Remember that we have seen this test.
- Test = {Op,Ops},
- SeenTests = gb_sets:insert(Test, SeenTests0),
- peep(Is, SeenTests, [I|Acc])
- end
- end;
-peep([I|Is], _, Acc) ->
- %% An unknown instruction. Throw away all information we
- %% have collected about test instructions.
- peep(Is, gb_sets:empty(), [I|Acc]);
-peep([], _, Acc) -> reverse(Acc).
-
-is_test_redundant(Op, Ops, Seen) ->
- gb_sets:is_element({Op,Ops}, Seen) orelse
- is_test_redundant_1(Op, Ops, Seen).
-
-is_test_redundant_1(is_boolean, [R], Seen) ->
- gb_sets:is_element({is_eq_exact,[R,{atom,false}]}, Seen) orelse
- gb_sets:is_element({is_eq_exact,[R,{atom,true}]}, Seen);
-is_test_redundant_1(_, _, _) -> false.
-
-kill_seen(Dst, Seen0) ->
- gb_sets:from_ordset(kill_seen_1(gb_sets:to_list(Seen0), Dst)).
-
-kill_seen_1([{_,Ops}=Test|T], Dst) ->
- case member(Dst, Ops) of
- true -> kill_seen_1(T, Dst);
- false -> [Test|kill_seen_1(T, Dst)]
- end;
-kill_seen_1([], _) -> [].
-
-prune_redundant_values([_Val,F|Vls], F) ->
- prune_redundant_values(Vls, F);
-prune_redundant_values([Val,Lbl|Vls], F) ->
- [Val,Lbl|prune_redundant_values(Vls, F)];
-prune_redundant_values([], _) -> [].
-
-simplify_get_map_elements(Fail, Src, {list,[Key,Dst]},
- [{get_map_elements,Fail,Src,{list,List1}}|Acc]) ->
- case are_keys_literals([Key]) andalso are_keys_literals(List1) andalso
- not is_source_overwritten(Src, List1) of
- true ->
- case member(Key, List1) of
- true ->
- %% The key is already in the other list. That is
- %% very unusual, because there are optimizations to get
- %% rid of duplicate keys. Therefore, don't try to
- %% do anything smart here; just keep the
- %% get_map_elements instructions separate.
- error;
- false ->
- List = [Key,Dst|List1],
- {ok,[{get_map_elements,Fail,Src,{list,List}}|Acc]}
- end;
- false ->
- error
- end;
-simplify_get_map_elements(_, _, _, _) -> error.
-
-simplify_has_map_fields(Fail, [Src|Keys0],
- [{test,has_map_fields,Fail,[Src|Keys1]}|Acc]) ->
- case are_keys_literals(Keys0) andalso are_keys_literals(Keys1) of
- true ->
- Keys = usort(Keys0 ++ Keys1),
- {ok,[{test,has_map_fields,Fail,[Src|Keys]}|Acc]};
- false ->
- error
- end;
-simplify_has_map_fields(_, _, _) -> error.
-
-are_keys_literals([{x,_}|_]) -> false;
-are_keys_literals([{y,_}|_]) -> false;
-are_keys_literals([_|_]) -> true.
-
-is_source_overwritten(Src, [_Key,Src]) -> true;
-is_source_overwritten(_, _) -> false.
diff --git a/lib/compiler/src/compile.erl b/lib/compiler/src/compile.erl
index 7a36c6333a..ef421c20e7 100644
--- a/lib/compiler/src/compile.erl
+++ b/lib/compiler/src/compile.erl
@@ -916,8 +916,6 @@ asm_passes() ->
{iff,dblk,{listing,"block"}},
{unless,no_jopt,{pass,beam_jump}},
{iff,djmp,{listing,"jump"}},
- {unless,no_peep_opt,{pass,beam_peep}},
- {iff,dpeep,{listing,"peep"}},
{pass,beam_clean},
{iff,dclean,{listing,"clean"}},
{unless,no_stack_trimming,{pass,beam_trim}},
@@ -2020,7 +2018,6 @@ pre_load() ->
beam_jump,
beam_kernel_to_ssa,
beam_opcodes,
- beam_peep,
beam_ssa,
beam_ssa_bc_size,
beam_ssa_bool,
diff --git a/lib/compiler/src/compiler.app.src b/lib/compiler/src/compiler.app.src
index 08827c66b3..6aa4009645 100644
--- a/lib/compiler/src/compiler.app.src
+++ b/lib/compiler/src/compiler.app.src
@@ -34,7 +34,6 @@
beam_kernel_to_ssa,
beam_listing,
beam_opcodes,
- beam_peep,
beam_ssa,
beam_ssa_bc_size,
beam_ssa_bool,
diff --git a/lib/compiler/test/compile_SUITE.erl b/lib/compiler/test/compile_SUITE.erl
index 7ab621fab5..d9f1ba0a9d 100644
--- a/lib/compiler/test/compile_SUITE.erl
+++ b/lib/compiler/test/compile_SUITE.erl
@@ -486,7 +486,6 @@ do_file_listings(DataDir, PrivDir, [File|Files]) ->
{dblk, ".block"},
{djmp, ".jump"},
{dclean, ".clean"},
- {dpeep, ".peep"},
{dopt, ".optimize"},
{diffable, ".S"}],
p_listings(List, Simple, TargetDir),
diff --git a/lib/compiler/test/misc_SUITE.erl b/lib/compiler/test/misc_SUITE.erl
index 5f24fb1f27..ae5fff2ed3 100644
--- a/lib/compiler/test/misc_SUITE.erl
+++ b/lib/compiler/test/misc_SUITE.erl
@@ -257,17 +257,6 @@ silly_coverage(Config) when is_list(Config) ->
TrimInput = BlockInput,
expect_error(fun() -> beam_trim:module(TrimInput, []) end),
- %% beam_peep. This is tricky. Use a select instruction with
- %% an odd number of elements in the list to crash
- %% prune_redundant_values/2 but not beam_clean:clean_labels/1.
- PeepInput = {?MODULE,[{foo,0}],[],
- [{function,foo,0,2,
- [{label,1},
- {func_info,{atom,?MODULE},{atom,foo},0},
- {label,2},{select,select_val,r,{f,2},[{f,2}]}]}],
- 2},
- expect_error(fun() -> beam_peep:module(PeepInput, []) end),
-
BeamZInput = {?MODULE,[{foo,0}],[],
[{function,foo,0,2,
[{label,1},
--
2.31.1
