From 6c91e303fe844ec9a795216bb9e4d39e760cecb8 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Mon, 5 Dec 2011 09:05:21 +0100 Subject: Teach the compiler the 'no_dead' option To facilitate debugging of compiler bugs, teach the compiler the 'no_dead' option. Since the beam_dead pass used to do the necessary splitting of basic blocks to expose all labels, we must move that splitting into a separate pass that is always run. --- lib/compiler/src/Makefile | 1 + lib/compiler/src/beam_dead.erl | 65 ++---------------------------- lib/compiler/src/beam_split.erl | 85 +++++++++++++++++++++++++++++++++++++++ lib/compiler/src/compile.erl | 4 +- lib/compiler/src/compiler.app.src | 1 + 5 files changed, 93 insertions(+), 63 deletions(-) create mode 100644 lib/compiler/src/beam_split.erl (limited to 'lib') diff --git a/lib/compiler/src/Makefile b/lib/compiler/src/Makefile index 1238d113e1..7a237608ad 100644 --- a/lib/compiler/src/Makefile +++ b/lib/compiler/src/Makefile @@ -59,6 +59,7 @@ MODULES = \ beam_opcodes \ beam_peep \ beam_receive \ + beam_split \ beam_trim \ beam_type \ beam_utils \ diff --git a/lib/compiler/src/beam_dead.erl b/lib/compiler/src/beam_dead.erl index 9f81a6ab43..5f12a98f09 100644 --- a/lib/compiler/src/beam_dead.erl +++ b/lib/compiler/src/beam_dead.erl @@ -131,10 +131,9 @@ -import(lists, [mapfoldl/3,reverse/1]). module({Mod,Exp,Attr,Fs0,_}, _Opts) -> - Fs1 = [split_blocks(F) || F <- Fs0], - {Fs2,Lc1} = beam_clean:clean_labels(Fs1), - {Fs,Lc} = mapfoldl(fun function/2, Lc1, Fs2), - %%{Fs,Lc} = {Fs2,Lc1}, + {Fs1,Lc1} = beam_clean:clean_labels(Fs0), + {Fs,Lc} = mapfoldl(fun function/2, Lc1, Fs1), + %%{Fs,Lc} = {Fs1,Lc1}, {ok,{Mod,Exp,Attr,Fs,Lc}}. function({function,Name,Arity,CLabel,Is0}, Lc0) -> @@ -160,64 +159,6 @@ function({function,Name,Arity,CLabel,Is0}, Lc0) -> erlang:raise(Class, Error, Stack) end. -%% We must split the basic block when we encounter instructions with labels, -%% such as catches and BIFs. All labels must be visible outside the blocks. - -split_blocks({function,Name,Arity,CLabel,Is0}) -> - Is = split_blocks(Is0, []), - {function,Name,Arity,CLabel,Is}. - -split_blocks([{block,Bl}|Is], Acc0) -> - Acc = split_block(Bl, [], Acc0), - split_blocks(Is, Acc); -split_blocks([I|Is], Acc) -> - split_blocks(Is, [I|Acc]); -split_blocks([], Acc) -> reverse(Acc). - -split_block([{set,[R],[_,_,_]=As,{bif,is_record,{f,Lbl}}}|Is], Bl, Acc) -> - %% is_record/3 must be translated by beam_clean; therefore, - %% it must be outside of any block. - split_block(Is, [], [{bif,is_record,{f,Lbl},As,R}|make_block(Bl, Acc)]); -split_block([{set,[R],As,{bif,N,{f,Lbl}=Fail}}|Is], Bl, Acc) when Lbl =/= 0 -> - split_block(Is, [], [{bif,N,Fail,As,R}|make_block(Bl, Acc)]); -split_block([{set,[R],As,{alloc,Live,{gc_bif,N,{f,Lbl}=Fail}}}|Is], Bl, Acc) - when Lbl =/= 0 -> - split_block(Is, [], [{gc_bif,N,Fail,Live,As,R}|make_block(Bl, Acc)]); -split_block([{set,[R],[],{'catch',L}}|Is], Bl, Acc) -> - split_block(Is, [], [{'catch',R,L}|make_block(Bl, Acc)]); -split_block([{set,[],[],{line,_}=Line}|Is], Bl, Acc) -> - split_block(Is, [], [Line|make_block(Bl, Acc)]); -split_block([I|Is], Bl, Acc) -> - split_block(Is, [I|Bl], Acc); -split_block([], Bl, Acc) -> make_block(Bl, Acc). - -make_block([], Acc) -> Acc; -make_block([{set,[D],Ss,{bif,Op,Fail}}|Bl]=Bl0, Acc) -> - %% If the last instruction in the block is a comparison or boolean operator - %% (such as '=:='), move it out of the block to facilitate further - %% optimizations. - Arity = length(Ss), - case erl_internal:comp_op(Op, Arity) orelse - erl_internal:new_type_test(Op, Arity) orelse - erl_internal:bool_op(Op, Arity) of - false -> - [{block,reverse(Bl0)}|Acc]; - true -> - I = {bif,Op,Fail,Ss,D}, - case Bl =:= [] of - true -> [I|Acc]; - false -> [I,{block,reverse(Bl)}|Acc] - end - end; -make_block([{set,[Dst],[Src],move}|Bl], Acc) -> - %% Make optimization of {move,Src,Dst}, {jump,...} possible. - I = {move,Src,Dst}, - case Bl =:= [] of - true -> [I|Acc]; - false -> [I,{block,reverse(Bl)}|Acc] - end; -make_block(Bl, Acc) -> [{block,reverse(Bl)}|Acc]. - %% 'move' instructions outside of blocks may thwart the jump optimizer. %% Move them back into the block. diff --git a/lib/compiler/src/beam_split.erl b/lib/compiler/src/beam_split.erl new file mode 100644 index 0000000000..cacaaebffe --- /dev/null +++ b/lib/compiler/src/beam_split.erl @@ -0,0 +1,85 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2011. All Rights Reserved. +%% +%% The contents of this file are subject to the Erlang Public License, +%% Version 1.1, (the "License"); you may not use this file except in +%% compliance with the License. You should have received a copy of the +%% Erlang Public License along with this software. If not, it can be +%% retrieved online at http://www.erlang.org/. +%% +%% Software distributed under the License is distributed on an "AS IS" +%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See +%% the License for the specific language governing rights and limitations +%% under the License. +%% +%% %CopyrightEnd% +%% + +-module(beam_split). +-export([module/2]). + +-import(lists, [reverse/1]). + +module({Mod,Exp,Attr,Fs0,Lc}, _Opts) -> + Fs = [split_blocks(F) || F <- Fs0], + {ok,{Mod,Exp,Attr,Fs,Lc}}. + +%% We must split the basic block when we encounter instructions with labels, +%% such as catches and BIFs. All labels must be visible outside the blocks. + +split_blocks({function,Name,Arity,CLabel,Is0}) -> + Is = split_blocks(Is0, []), + {function,Name,Arity,CLabel,Is}. + +split_blocks([{block,Bl}|Is], Acc0) -> + Acc = split_block(Bl, [], Acc0), + split_blocks(Is, Acc); +split_blocks([I|Is], Acc) -> + split_blocks(Is, [I|Acc]); +split_blocks([], Acc) -> reverse(Acc). + +split_block([{set,[R],[_,_,_]=As,{bif,is_record,{f,Lbl}}}|Is], Bl, Acc) -> + %% is_record/3 must be translated by beam_clean; therefore, + %% it must be outside of any block. + split_block(Is, [], [{bif,is_record,{f,Lbl},As,R}|make_block(Bl, Acc)]); +split_block([{set,[R],As,{bif,N,{f,Lbl}=Fail}}|Is], Bl, Acc) when Lbl =/= 0 -> + split_block(Is, [], [{bif,N,Fail,As,R}|make_block(Bl, Acc)]); +split_block([{set,[R],As,{alloc,Live,{gc_bif,N,{f,Lbl}=Fail}}}|Is], Bl, Acc) + when Lbl =/= 0 -> + split_block(Is, [], [{gc_bif,N,Fail,Live,As,R}|make_block(Bl, Acc)]); +split_block([{set,[R],[],{'catch',L}}|Is], Bl, Acc) -> + split_block(Is, [], [{'catch',R,L}|make_block(Bl, Acc)]); +split_block([{set,[],[],{line,_}=Line}|Is], Bl, Acc) -> + split_block(Is, [], [Line|make_block(Bl, Acc)]); +split_block([I|Is], Bl, Acc) -> + split_block(Is, [I|Bl], Acc); +split_block([], Bl, Acc) -> make_block(Bl, Acc). + +make_block([], Acc) -> Acc; +make_block([{set,[D],Ss,{bif,Op,Fail}}|Bl]=Bl0, Acc) -> + %% If the last instruction in the block is a comparison or boolean operator + %% (such as '=:='), move it out of the block to facilitate further + %% optimizations. + Arity = length(Ss), + case erl_internal:comp_op(Op, Arity) orelse + erl_internal:new_type_test(Op, Arity) orelse + erl_internal:bool_op(Op, Arity) of + false -> + [{block,reverse(Bl0)}|Acc]; + true -> + I = {bif,Op,Fail,Ss,D}, + case Bl =:= [] of + true -> [I|Acc]; + false -> [I,{block,reverse(Bl)}|Acc] + end + end; +make_block([{set,[Dst],[Src],move}|Bl], Acc) -> + %% Make optimization of {move,Src,Dst}, {jump,...} possible. + I = {move,Src,Dst}, + case Bl =:= [] of + true -> [I|Acc]; + false -> [I,{block,reverse(Bl)}|Acc] + end; +make_block(Bl, Acc) -> [{block,reverse(Bl)}|Acc]. diff --git a/lib/compiler/src/compile.erl b/lib/compiler/src/compile.erl index 8815cfb26f..a17a10046e 100644 --- a/lib/compiler/src/compile.erl +++ b/lib/compiler/src/compile.erl @@ -633,7 +633,9 @@ asm_passes() -> {iff,dbool,{listing,"bool"}}, {unless,no_topt,{pass,beam_type}}, {iff,dtype,{listing,"type"}}, - {pass,beam_dead}, %Must always run since it splits blocks. + {pass,beam_split}, + {iff,dsplit,{listing,"split"}}, + {unless,no_dead,{pass,beam_dead}}, {iff,ddead,{listing,"dead"}}, {unless,no_jopt,{pass,beam_jump}}, {iff,djmp,{listing,"jump"}}, diff --git a/lib/compiler/src/compiler.app.src b/lib/compiler/src/compiler.app.src index 4ac879c9a4..efa25fe039 100644 --- a/lib/compiler/src/compiler.app.src +++ b/lib/compiler/src/compiler.app.src @@ -34,6 +34,7 @@ beam_opcodes, beam_peep, beam_receive, + beam_split, beam_trim, beam_type, beam_utils, -- cgit v1.2.3