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Diffstat (limited to 'lib/compiler/src/beam_ssa.erl')
| -rw-r--r-- | lib/compiler/src/beam_ssa.erl | 898 |
1 files changed, 898 insertions, 0 deletions
diff --git a/lib/compiler/src/beam_ssa.erl b/lib/compiler/src/beam_ssa.erl new file mode 100644 index 0000000000..6492d1e1bf --- /dev/null +++ b/lib/compiler/src/beam_ssa.erl @@ -0,0 +1,898 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2018. 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% +%% +%% Purpose: Type definitions and utilities for the SSA format. + +-module(beam_ssa). +-export([add_anno/3,get_anno/2,get_anno/3, + clobbers_xregs/1,def/2,def_used/2, + definitions/1, + dominators/1,common_dominators/3, + flatmapfold_instrs_rpo/4, + fold_po/3,fold_po/4,fold_rpo/3,fold_rpo/4, + fold_instrs_rpo/4, + linearize/1, + mapfold_blocks_rpo/4, + mapfold_instrs_rpo/4, + normalize/1, + no_side_effect/1, + predecessors/1, + rename_vars/3, + rpo/1,rpo/2, + split_blocks/3, + successors/1,successors/2, + trim_unreachable/1, + update_phi_labels/4,used/1, + uses/1,uses/2]). + +-export_type([b_module/0,b_function/0,b_blk/0,b_set/0, + b_ret/0,b_br/0,b_switch/0,terminator/0, + b_var/0,b_literal/0,b_remote/0,b_local/0, + value/0,argument/0,label/0, + var_name/0,var_base/0,literal_value/0, + op/0,anno/0,block_map/0,dominator_map/0, + rename_map/0,rename_proplist/0,usage_map/0, + definition_map/0]). + +-include("beam_ssa.hrl"). + +-type b_module() :: #b_module{}. +-type b_function() :: #b_function{}. +-type b_blk() :: #b_blk{}. +-type b_set() :: #b_set{}. + +-type b_br() :: #b_br{}. +-type b_ret() :: #b_ret{}. +-type b_switch() :: #b_switch{}. +-type terminator() :: b_br() | b_ret() | b_switch(). + +-type construct() :: b_module() | b_function() | b_blk() | b_set() | + terminator(). + +-type b_var() :: #b_var{}. +-type b_literal() :: #b_literal{}. +-type b_remote() :: #b_remote{}. +-type b_local() :: #b_local{}. + +-type value() :: b_var() | b_literal(). +-type phi_value() :: {value(),label()}. +-type argument() :: value() | b_remote() | b_local() | phi_value(). +-type label() :: non_neg_integer(). + +-type var_name() :: var_base() | {var_base(),non_neg_integer()}. +-type var_base() :: atom() | non_neg_integer(). + +-type literal_value() :: atom() | integer() | float() | list() | + nil() | tuple() | map() | binary(). + +-type op() :: {'bif',atom()} | {'float',float_op()} | prim_op() | cg_prim_op(). +-type anno() :: #{atom() := any()}. + +-type block_map() :: #{label():=b_blk()}. +-type dominator_map() :: #{label():=[label()]}. +-type numbering_map() :: #{label():=non_neg_integer()}. +-type usage_map() :: #{b_var():=[{label(),b_set() | terminator()}]}. +-type definition_map() :: #{b_var():=b_set()}. +-type rename_map() :: #{b_var():=value()}. +-type rename_proplist() :: [{b_var(),value()}]. + +%% Note: By default, dialyzer will collapse this type to atom(). +%% To avoid the collapsing, change the value of SET_LIMIT to 50 in the +%% file erl_types.erl in the hipe application. + +-type prim_op() :: 'bs_add' | 'bs_extract' | 'bs_get_tail' | + 'bs_init' | 'bs_init_writable' | + 'bs_match' | 'bs_put' | 'bs_start_match' | 'bs_test_tail' | + 'bs_utf16_size' | 'bs_utf8_size' | 'build_stacktrace' | + 'call' | 'catch_end' | + 'extract' | + 'get_hd' | 'get_map_element' | 'get_tl' | 'get_tuple_element' | + 'has_map_field' | + 'is_nonempty_list' | 'is_tagged_tuple' | + 'kill_try_tag' | + 'landingpad' | + 'make_fun' | 'new_try_tag' | + 'peek_message' | 'phi' | 'put_list' | 'put_map' | 'put_tuple' | + 'raw_raise' | 'recv_next' | 'remove_message' | 'resume' | + 'succeeded' | + 'timeout' | + 'wait' | 'wait_timeout'. + +-type float_op() :: 'checkerror' | 'clearerror' | 'convert' | 'get' | 'put' | + '+' | '-' | '*' | '/'. + +%% Primops only used internally during code generation. +-type cg_prim_op() :: 'bs_get' | 'bs_get_position' | 'bs_match_string' | + 'bs_restore' | 'bs_save' | 'bs_set_position' | 'bs_skip' | + 'copy' | 'put_tuple_arity' | 'put_tuple_element' | + 'put_tuple_elements' | 'set_tuple_element'. + +-import(lists, [foldl/3,keyfind/3,mapfoldl/3,member/2,reverse/1,umerge/1]). + +-spec add_anno(Key, Value, Construct) -> Construct when + Key :: atom(), + Value :: any(), + Construct :: construct(). + +add_anno(Key, Val, #b_function{anno=Anno}=Bl) -> + Bl#b_function{anno=Anno#{Key=>Val}}; +add_anno(Key, Val, #b_blk{anno=Anno}=Bl) -> + Bl#b_blk{anno=Anno#{Key=>Val}}; +add_anno(Key, Val, #b_set{anno=Anno}=Bl) -> + Bl#b_set{anno=Anno#{Key=>Val}}; +add_anno(Key, Val, #b_br{anno=Anno}=Bl) -> + Bl#b_br{anno=Anno#{Key=>Val}}; +add_anno(Key, Val, #b_ret{anno=Anno}=Bl) -> + Bl#b_ret{anno=Anno#{Key=>Val}}; +add_anno(Key, Val, #b_switch{anno=Anno}=Bl) -> + Bl#b_switch{anno=Anno#{Key=>Val}}. + +-spec get_anno(atom(), construct()) -> any(). + +get_anno(Key, Construct) -> + map_get(Key, get_anno(Construct)). + +-spec get_anno(atom(), construct(),any()) -> any(). + +get_anno(Key, Construct, Default) -> + maps:get(Key, get_anno(Construct), Default). + +get_anno(#b_function{anno=Anno}) -> Anno; +get_anno(#b_blk{anno=Anno}) -> Anno; +get_anno(#b_set{anno=Anno}) -> Anno; +get_anno(#b_br{anno=Anno}) -> Anno; +get_anno(#b_ret{anno=Anno}) -> Anno; +get_anno(#b_switch{anno=Anno}) -> Anno. + +%% clobbers_xregs(#b_set{}) -> true|false. +%% Test whether the instruction invalidates all X registers. + +-spec clobbers_xregs(b_set()) -> boolean(). + +clobbers_xregs(#b_set{op=Op}) -> + case Op of + bs_init_writable -> true; + build_stacktrace -> true; + call -> true; + landingpad -> true; + make_fun -> true; + peek_message -> true; + raw_raise -> true; + _ -> false + end. + +%% no_side_effect(#b_set{}) -> true|false. +%% Test whether this instruction has no side effect and thus is safe +%% not to execute if its value is not used. Note that even if `true` +%% is returned, the instruction could still be impure (e.g. bif:get). + +-spec no_side_effect(b_set()) -> boolean(). + +no_side_effect(#b_set{op=Op}) -> + case Op of + {bif,_} -> true; + {float,get} -> true; + bs_init -> true; + bs_extract -> true; + bs_match -> true; + bs_start_match -> true; + bs_test_tail -> true; + bs_get_tail -> true; + bs_put -> true; + extract -> true; + get_hd -> true; + get_tl -> true; + get_map_element -> true; + get_tuple_element -> true; + has_map_field -> true; + is_nonempty_list -> true; + is_tagged_tuple -> true; + make_fun -> true; + put_map -> true; + put_list -> true; + put_tuple -> true; + succeeded -> true; + _ -> false + end. + +-spec predecessors(Blocks) -> #{BlockNumber:=[Predecessor]} when + Blocks :: block_map(), + BlockNumber :: label(), + Predecessor :: label(). + +predecessors(Blocks) -> + P0 = [{S,L} || {L,Blk} <- maps:to_list(Blocks), + S <- successors(Blk)], + P1 = sofs:relation(P0), + P2 = sofs:rel2fam(P1), + P3 = sofs:to_external(P2), + P = [{0,[]}|P3], + maps:from_list(P). + +-spec successors(b_blk()) -> [label()]. + +successors(#b_blk{last=Terminator}) -> + case Terminator of + #b_br{bool=#b_literal{val=true},succ=Succ} -> + [Succ]; + #b_br{bool=#b_literal{val=false},fail=Fail} -> + [Fail]; + #b_br{succ=Succ,fail=Fail} -> + [Fail,Succ]; + #b_switch{fail=Fail,list=List} -> + [Fail|[L || {_,L} <- List]]; + #b_ret{} -> + [] + end. + +%% normalize(Instr0) -> Instr. +%% Normalize instructions to help optimizations. +%% +%% For commutative operators (such as '+' and 'or'), always +%% place a variable operand before a literal operand. +%% +%% Normalize #b_br{} to one of the following forms: +%% +%% #b_br{b_literal{val=true},succ=Label,fail=Label} +%% #b_br{b_var{},succ=Label1,fail=Label2} where Label1 =/= Label2 +%% +%% Simplify a #b_switch{} with a literal argument to a #b_br{}. +%% +%% Simplify a #b_switch{} with a variable argument and an empty +%% switch list to a #b_br{}. + +-spec normalize(b_set() | terminator()) -> + b_set() | terminator(). + +normalize(#b_set{op={bif,Bif},args=Args}=Set) -> + case {is_commutative(Bif),Args} of + {false,_} -> + Set; + {true,[#b_literal{}=Lit,#b_var{}=Var]} -> + Set#b_set{args=[Var,Lit]}; + {true,_} -> + Set + end; +normalize(#b_set{}=Set) -> + Set; +normalize(#b_br{}=Br) -> + case Br of + #b_br{bool=Bool,succ=Same,fail=Same} -> + case Bool of + #b_literal{val=true} -> + Br; + _ -> + Br#b_br{bool=#b_literal{val=true}} + end; + #b_br{bool=#b_literal{val=true},succ=Succ} -> + Br#b_br{fail=Succ}; + #b_br{bool=#b_literal{val=false},fail=Fail} -> + Br#b_br{bool=#b_literal{val=true},succ=Fail}; + #b_br{} -> + Br + end; +normalize(#b_switch{arg=Arg,fail=Fail,list=List}=Sw) -> + case Arg of + #b_literal{} -> + case keyfind(Arg, 1, List) of + false -> + #b_br{bool=#b_literal{val=true},succ=Fail,fail=Fail}; + {Arg,L} -> + #b_br{bool=#b_literal{val=true},succ=L,fail=L} + end; + #b_var{} when List =:= [] -> + #b_br{bool=#b_literal{val=true},succ=Fail,fail=Fail}; + #b_var{} -> + Sw + end; +normalize(#b_ret{}=Ret) -> + Ret. + +-spec successors(label(), block_map()) -> [label()]. + +successors(L, Blocks) -> + successors(map_get(L, Blocks)). + +-spec def(Ls, Blocks) -> Def when + Ls :: [label()], + Blocks :: block_map(), + Def :: ordsets:ordset(var_name()). + +def(Ls, Blocks) -> + Top = rpo(Ls, Blocks), + Blks = [map_get(L, Blocks) || L <- Top], + def_1(Blks, []). + +-spec def_used(Ls, Blocks) -> {Def,Used} when + Ls :: [label()], + Blocks :: block_map(), + Def :: ordsets:ordset(var_name()), + Used :: ordsets:ordset(var_name()). + +def_used(Ls, Blocks) -> + Top = rpo(Ls, Blocks), + Blks = [map_get(L, Blocks) || L <- Top], + Preds = cerl_sets:from_list(Top), + def_used_1(Blks, Preds, [], []). + +%% dominators(BlockMap) -> {Dominators,Numbering}. +%% Calculate the dominator tree, returning a map where each entry +%% in the map is a list that gives the path from that block to +%% the top of the dominator tree. (Note that the suffixes of the +%% paths are shared with each other, which make the representation +%% of the dominator tree highly memory-efficient.) +%% +%% The implementation is based on: +%% +%% http://www.hipersoft.rice.edu/grads/publications/dom14.pdf +%% Cooper, Keith D.; Harvey, Timothy J; Kennedy, Ken (2001). +%% A Simple, Fast Dominance Algorithm. + +-spec dominators(Blocks) -> Result when + Blocks :: block_map(), + Result :: {dominator_map(), numbering_map()}. +dominators(Blocks) -> + Preds = predecessors(Blocks), + Top0 = rpo(Blocks), + Df = maps:from_list(number(Top0, 0)), + [{0,[]}|Top] = [{L,map_get(L, Preds)} || L <- Top0], + + %% The flow graph for an Erlang function is reducible, and + %% therefore one traversal in reverse postorder is sufficient. + Acc = #{0=>[0]}, + {dominators_1(Top, Df, Acc),Df}. + +%% common_dominators([Label], Dominators, Numbering) -> [Label]. +%% Calculate the common dominators for the given list of blocks +%% and Dominators and Numbering as returned from dominators/1. + +-spec common_dominators([label()], dominator_map(), numbering_map()) -> [label()]. +common_dominators(Ls, Dom, Numbering) -> + Doms = [map_get(L, Dom) || L <- Ls], + dom_intersection(Doms, Numbering). + +-spec fold_instrs_rpo(Fun, From, Acc0, Blocks) -> any() when + Fun :: fun((b_blk()|terminator(), any()) -> any()), + From :: [label()], + Acc0 :: any(), + Blocks :: block_map(). + +fold_instrs_rpo(Fun, From, Acc0, Blocks) -> + Top = rpo(From, Blocks), + fold_instrs_rpo_1(Top, Fun, Blocks, Acc0). + +%% Like mapfold_instrs_rpo but at the block level to support lookahead and +%% scope-dependent transformations. +-spec mapfold_blocks_rpo(Fun, From, Acc, Blocks) -> Result when + Fun :: fun((label(), b_blk(), any()) -> {b_blk(), any()}), + From :: [label()], + Acc :: any(), + Blocks :: block_map(), + Result :: {block_map(), any()}. +mapfold_blocks_rpo(Fun, From, Acc, Blocks) -> + Successors = rpo(From, Blocks), + foldl(fun(Lbl, A) -> + mapfold_blocks_rpo_1(Fun, Lbl, A) + end, {Blocks, Acc}, Successors). + +mapfold_blocks_rpo_1(Fun, Lbl, {Blocks0, Acc0}) -> + Block0 = map_get(Lbl, Blocks0), + {Block, Acc} = Fun(Lbl, Block0, Acc0), + Blocks = Blocks0#{Lbl:=Block}, + {Blocks, Acc}. + +-spec mapfold_instrs_rpo(Fun, From, Acc0, Blocks0) -> {Blocks,Acc} when + Fun :: fun((b_blk()|terminator(), any()) -> any()), + From :: [label()], + Acc0 :: any(), + Acc :: any(), + Blocks0 :: block_map(), + Blocks :: block_map(). + +mapfold_instrs_rpo(Fun, From, Acc0, Blocks) -> + Top = rpo(From, Blocks), + mapfold_instrs_rpo_1(Top, Fun, Blocks, Acc0). + +-spec flatmapfold_instrs_rpo(Fun, From, Acc0, Blocks0) -> {Blocks,Acc} when + Fun :: fun((b_blk()|terminator(), any()) -> any()), + From :: [label()], + Acc0 :: any(), + Acc :: any(), + Blocks0 :: block_map(), + Blocks :: block_map(). + +flatmapfold_instrs_rpo(Fun, From, Acc0, Blocks) -> + Top = rpo(From, Blocks), + flatmapfold_instrs_rpo_1(Top, Fun, Blocks, Acc0). + +-type fold_fun() :: fun((label(), b_blk(), any()) -> any()). + +%% fold_rpo(Fun, [Label], Acc0, Blocks) -> Acc. +%% Fold over all blocks a reverse postorder traversal of the block +%% graph; that is, first visit a block, then visit its successors. + +-spec fold_rpo(Fun, Acc0, Blocks) -> any() when + Fun :: fold_fun(), + Acc0 :: any(), + Blocks :: #{label():=b_blk()}. + +fold_rpo(Fun, Acc0, Blocks) -> + fold_rpo(Fun, [0], Acc0, Blocks). + +%% fold_rpo(Fun, [Label], Acc0, Blocks) -> Acc. Fold over all blocks +%% reachable from a given set of labels in a reverse postorder +%% traversal of the block graph; that is, first visit a block, then +%% visit its successors. + +-spec fold_rpo(Fun, Labels, Acc0, Blocks) -> any() when + Fun :: fold_fun(), + Labels :: [label()], + Acc0 :: any(), + Blocks :: #{label():=b_blk()}. + +fold_rpo(Fun, From, Acc0, Blocks) -> + Top = rpo(From, Blocks), + fold_rpo_1(Top, Fun, Blocks, Acc0). + +%% fold_po(Fun, Acc0, Blocks) -> Acc. +%% Fold over all blocks in a postorder traversal of the block graph; +%% that is, first visit all successors of block, then the block +%% itself. + +-spec fold_po(Fun, Acc0, Blocks) -> any() when + Fun :: fold_fun(), + Acc0 :: any(), + Blocks :: #{label():=b_blk()}. + +%% fold_po(Fun, From, Acc0, Blocks) -> Acc. +%% Fold over the blocks reachable from the block numbers given +%% by From in a postorder traversal of the block graph. + +fold_po(Fun, Acc0, Blocks) -> + fold_po(Fun, [0], Acc0, Blocks). + +-spec fold_po(Fun, Labels, Acc0, Blocks) -> any() when + Fun :: fold_fun(), + Labels :: [label()], + Acc0 :: any(), + Blocks :: block_map(). + +fold_po(Fun, From, Acc0, Blocks) -> + Top = reverse(rpo(From, Blocks)), + fold_rpo_1(Top, Fun, Blocks, Acc0). + +%% linearize(Blocks) -> [{BlockLabel,#b_blk{}}]. +%% Linearize the intermediate representation of the code. +%% Unreachable blocks will be discarded, and phi nodes will +%% be adjusted so that they no longer refers to discarded +%% blocks or to blocks that no longer are predecessors of +%% the phi node block. + +-spec linearize(Blocks) -> Linear when + Blocks :: block_map(), + Linear :: [{label(),b_blk()}]. + +linearize(Blocks) -> + Seen = cerl_sets:new(), + {Linear0,_} = linearize_1([0], Blocks, Seen, []), + Linear = fix_phis(Linear0, #{}), + Linear. + +-spec rpo(Blocks) -> [Label] when + Blocks :: block_map(), + Label :: label(). + +rpo(Blocks) -> + rpo([0], Blocks). + +-spec rpo(From, Blocks) -> Labels when + From :: [label()], + Blocks :: block_map(), + Labels :: [label()]. + +rpo(From, Blocks) -> + Seen = cerl_sets:new(), + {Ls,_} = rpo_1(From, Blocks, Seen, []), + Ls. + +-spec rename_vars(Rename, [label()], block_map()) -> block_map() when + Rename :: rename_map() | rename_proplist(). + +rename_vars(Rename, From, Blocks) when is_list(Rename) -> + rename_vars(maps:from_list(Rename), From, Blocks); +rename_vars(Rename, From, Blocks) when is_map(Rename)-> + Top = rpo(From, Blocks), + Preds = cerl_sets:from_list(Top), + F = fun(#b_set{op=phi,args=Args0}=Set) -> + Args = rename_phi_vars(Args0, Preds, Rename), + Set#b_set{args=Args}; + (#b_set{args=Args0}=Set) -> + Args = [rename_var(A, Rename) || A <- Args0], + Set#b_set{args=Args}; + (#b_switch{arg=Bool}=Sw) -> + Sw#b_switch{arg=rename_var(Bool, Rename)}; + (#b_br{bool=Bool}=Br) -> + Br#b_br{bool=rename_var(Bool, Rename)}; + (#b_ret{arg=Arg}=Ret) -> + Ret#b_ret{arg=rename_var(Arg, Rename)} + end, + map_instrs_1(Top, F, Blocks). + +%% split_blocks(Predicate, Blocks0, Count0) -> {Blocks,Count}. +%% Call Predicate(Instruction) for each instruction in all +%% blocks. If Predicate/1 returns true, split the block +%% before this instruction. + +-spec split_blocks(Pred, Blocks0, Count0) -> {Blocks,Count} when + Pred :: fun((b_set()) -> boolean()), + Blocks :: block_map(), + Count0 :: beam_ssa:label(), + Blocks0 :: block_map(), + Blocks :: block_map(), + Count :: beam_ssa:label(). + +split_blocks(P, Blocks, Count) -> + Ls = beam_ssa:rpo(Blocks), + split_blocks_1(Ls, P, Blocks, Count). + +-spec trim_unreachable(Blocks0) -> Blocks when + Blocks0 :: block_map(), + Blocks :: block_map(). + +%% trim_unreachable(Blocks0) -> Blocks. +%% Remove all unreachable blocks. Adjust all phi nodes so +%% they don't refer to blocks that has been removed or no +%% no longer branch to the phi node in question. + +trim_unreachable(Blocks) -> + %% Could perhaps be optimized if there is any need. + maps:from_list(linearize(Blocks)). + +%% update_phi_labels([BlockLabel], Old, New, Blocks0) -> Blocks. +%% In the given blocks, replace label Old in with New in all +%% phi nodes. This is useful after merging or splitting +%% blocks. + +-spec update_phi_labels(From, Old, New, Blocks0) -> Blocks when + From :: [label()], + Old :: label(), + New :: label(), + Blocks0 :: block_map(), + Blocks :: block_map(). + +update_phi_labels([L|Ls], Old, New, Blocks0) -> + case Blocks0 of + #{L:=#b_blk{is=[#b_set{op=phi}|_]=Is0}=Blk0} -> + Is = update_phi_labels_is(Is0, Old, New), + Blk = Blk0#b_blk{is=Is}, + Blocks = Blocks0#{L:=Blk}, + update_phi_labels(Ls, Old, New, Blocks); + #{L:=#b_blk{}} -> + %% No phi nodes in this block. + update_phi_labels(Ls, Old, New, Blocks0) + end; +update_phi_labels([], _, _, Blocks) -> Blocks. + +-spec used(b_blk() | b_set() | terminator()) -> [var_name()]. + +used(#b_blk{is=Is,last=Last}) -> + used_1([Last|Is], ordsets:new()); +used(#b_br{bool=#b_var{}=V}) -> + [V]; +used(#b_ret{arg=#b_var{}=V}) -> + [V]; +used(#b_set{op=phi,args=Args}) -> + ordsets:from_list([V || {#b_var{}=V,_} <- Args]); +used(#b_set{args=Args}) -> + ordsets:from_list(used_args(Args)); +used(#b_switch{arg=#b_var{}=V}) -> + [V]; +used(_) -> []. + +-spec definitions(Blocks :: block_map()) -> definition_map(). +definitions(Blocks) -> + fold_instrs_rpo(fun(#b_set{ dst = Var }=I, Acc) -> + Acc#{Var => I}; + (_Terminator, Acc) -> + Acc + end, [0], #{}, Blocks). + +-spec uses(Blocks :: block_map()) -> usage_map(). +uses(Blocks) -> + uses([0], Blocks). + +-spec uses(From, Blocks) -> usage_map() when + From :: [label()], + Blocks :: block_map(). +uses(From, Blocks) -> + fold_rpo(fun fold_uses_block/3, From, #{}, Blocks). + +fold_uses_block(Lbl, #b_blk{is=Is,last=Last}, UseMap0) -> + F = fun(I, UseMap) -> + foldl(fun(Var, Acc) -> + Uses0 = maps:get(Var, Acc, []), + Uses = [{Lbl, I} | Uses0], + maps:put(Var, Uses, Acc) + end, UseMap, used(I)) + end, + F(Last, foldl(F, UseMap0, Is)). + +%%% +%%% Internal functions. +%%% + +is_commutative('and') -> true; +is_commutative('or') -> true; +is_commutative('xor') -> true; +is_commutative('band') -> true; +is_commutative('bor') -> true; +is_commutative('bxor') -> true; +is_commutative('+') -> true; +is_commutative('*') -> true; +is_commutative('=:=') -> true; +is_commutative('==') -> true; +is_commutative('=/=') -> true; +is_commutative('/=') -> true; +is_commutative(_) -> false. + +def_used_1([#b_blk{is=Is,last=Last}|Bs], Preds, Def0, UsedAcc) -> + {Def,Used} = def_used_is(Is, Preds, Def0, used(Last)), + case Used of + [] -> + def_used_1(Bs, Preds, Def, UsedAcc); + [_|_] -> + def_used_1(Bs, Preds, Def, [Used|UsedAcc]) + end; +def_used_1([], _Preds, Def0, UsedAcc) -> + Def = ordsets:from_list(Def0), + Used = umerge(UsedAcc), + {Def,Used}. + +def_used_is([#b_set{op=phi,dst=Dst,args=Args}|Is], + Preds, Def0, Used0) -> + Def = [Dst|Def0], + %% We must be careful to only include variables that will + %% be used when arriving from one of the predecessor blocks + %% in Preds. + Used1 = [V || {#b_var{}=V,L} <- Args, cerl_sets:is_element(L, Preds)], + Used = ordsets:union(ordsets:from_list(Used1), Used0), + def_used_is(Is, Preds, Def, Used); +def_used_is([#b_set{dst=Dst}=I|Is], Preds, Def0, Used0) -> + Def = [Dst|Def0], + Used = ordsets:union(used(I), Used0), + def_used_is(Is, Preds, Def, Used); +def_used_is([], _Preds, Def, Used) -> + {Def,Used}. + +def_1([#b_blk{is=Is}|Bs], Def0) -> + Def = def_is(Is, Def0), + def_1(Bs, Def); +def_1([], Def) -> + ordsets:from_list(Def). + +def_is([#b_set{dst=Dst}|Is], Def) -> + def_is(Is, [Dst|Def]); +def_is([], Def) -> Def. + +dominators_1([{L,Preds}|Ls], Df, Doms) -> + DomPreds = [map_get(P, Doms) || P <- Preds, is_map_key(P, Doms)], + Dom = [L|dom_intersection(DomPreds, Df)], + dominators_1(Ls, Df, Doms#{L=>Dom}); +dominators_1([], _Df, Doms) -> Doms. + +dom_intersection([S], _Df) -> + S; +dom_intersection([S|Ss], Df) -> + dom_intersection(S, Ss, Df). + +dom_intersection(S1, [S2|Ss], Df) -> + dom_intersection(dom_intersection_1(S1, S2, Df), Ss, Df); +dom_intersection(S, [], _Df) -> S. + +dom_intersection_1([E1|Es1]=Set1, [E2|Es2]=Set2, Df) -> + %% Blocks are numbered in the order they are found in + %% reverse postorder. + #{E1:=Df1,E2:=Df2} = Df, + if Df1 > Df2 -> + dom_intersection_1(Es1, Set2, Df); + Df2 > Df1 -> + dom_intersection_1(Es2, Set1, Df); %switch arguments! + true -> %Set1 == Set2 + %% The common suffix of the sets is the intersection. + Set1 + end. + +number([L|Ls], N) -> + [{L,N}|number(Ls, N+1)]; +number([], _) -> []. + +fold_rpo_1([L|Ls], Fun, Blocks, Acc0) -> + Block = map_get(L, Blocks), + Acc = Fun(L, Block, Acc0), + fold_rpo_1(Ls, Fun, Blocks, Acc); +fold_rpo_1([], _, _, Acc) -> Acc. + +fold_instrs_rpo_1([L|Ls], Fun, Blocks, Acc0) -> + #b_blk{is=Is,last=Last} = map_get(L, Blocks), + Acc1 = foldl(Fun, Acc0, Is), + Acc = Fun(Last, Acc1), + fold_instrs_rpo_1(Ls, Fun, Blocks, Acc); +fold_instrs_rpo_1([], _, _, Acc) -> Acc. + +mapfold_instrs_rpo_1([L|Ls], Fun, Blocks0, Acc0) -> + #b_blk{is=Is0,last=Last0} = Block0 = map_get(L, Blocks0), + {Is,Acc1} = mapfoldl(Fun, Acc0, Is0), + {Last,Acc} = Fun(Last0, Acc1), + Block = Block0#b_blk{is=Is,last=Last}, + Blocks = Blocks0#{L:=Block}, + mapfold_instrs_rpo_1(Ls, Fun, Blocks, Acc); +mapfold_instrs_rpo_1([], _, Blocks, Acc) -> + {Blocks,Acc}. + +flatmapfold_instrs_rpo_1([L|Ls], Fun, Blocks0, Acc0) -> + #b_blk{is=Is0,last=Last0} = Block0 = map_get(L, Blocks0), + {Is,Acc1} = flatmapfoldl(Fun, Acc0, Is0), + {[Last],Acc} = Fun(Last0, Acc1), + Block = Block0#b_blk{is=Is,last=Last}, + Blocks = Blocks0#{L:=Block}, + flatmapfold_instrs_rpo_1(Ls, Fun, Blocks, Acc); +flatmapfold_instrs_rpo_1([], _, Blocks, Acc) -> + {Blocks,Acc}. + +linearize_1([L|Ls], Blocks, Seen0, Acc0) -> + case cerl_sets:is_element(L, Seen0) of + true -> + linearize_1(Ls, Blocks, Seen0, Acc0); + false -> + Seen1 = cerl_sets:add_element(L, Seen0), + Block = map_get(L, Blocks), + Successors = successors(Block), + {Acc,Seen} = linearize_1(Successors, Blocks, Seen1, Acc0), + linearize_1(Ls, Blocks, Seen, [{L,Block}|Acc]) + end; +linearize_1([], _, Seen, Acc) -> + {Acc,Seen}. + +fix_phis([{L,Blk0}|Bs], S) -> + Blk = case Blk0 of + #b_blk{is=[#b_set{op=phi}|_]=Is0} -> + Is = fix_phis_1(Is0, L, S), + Blk0#b_blk{is=Is}; + #b_blk{} -> + Blk0 + end, + Successors = successors(Blk), + [{L,Blk}|fix_phis(Bs, S#{L=>Successors})]; +fix_phis([], _) -> []. + +fix_phis_1([#b_set{op=phi,args=Args0}=I|Is], L, S) -> + Args = [{Val,Pred} || {Val,Pred} <- Args0, + is_successor(L, Pred, S)], + [I#b_set{args=Args}|fix_phis_1(Is, L, S)]; +fix_phis_1(Is, _, _) -> Is. + +is_successor(L, Pred, S) -> + case S of + #{Pred:=Successors} -> + member(L, Successors); + #{} -> + %% This block has been removed. + false + end. + +rpo_1([L|Ls], Blocks, Seen0, Acc0) -> + case cerl_sets:is_element(L, Seen0) of + true -> + rpo_1(Ls, Blocks, Seen0, Acc0); + false -> + Block = map_get(L, Blocks), + Seen1 = cerl_sets:add_element(L, Seen0), + Successors = successors(Block), + {Acc,Seen} = rpo_1(Successors, Blocks, Seen1, Acc0), + rpo_1(Ls, Blocks, Seen, [L|Acc]) + end; +rpo_1([], _, Seen, Acc) -> + {Acc,Seen}. + +rename_var(#b_var{}=Old, Rename) -> + case Rename of + #{Old:=New} -> New; + #{} -> Old + end; +rename_var(#b_remote{mod=Mod0,name=Name0}=Remote, Rename) -> + Mod = rename_var(Mod0, Rename), + Name = rename_var(Name0, Rename), + Remote#b_remote{mod=Mod,name=Name}; +rename_var(Old, _) -> Old. + +rename_phi_vars([{Var,L}|As], Preds, Ren) -> + case cerl_sets:is_element(L, Preds) of + true -> + [{rename_var(Var, Ren),L}|rename_phi_vars(As, Preds, Ren)]; + false -> + [{Var,L}|rename_phi_vars(As, Preds, Ren)] + end; +rename_phi_vars([], _, _) -> []. + +map_instrs_1([L|Ls], Fun, Blocks0) -> + #b_blk{is=Is0,last=Last0} = Blk0 = map_get(L, Blocks0), + Is = [Fun(I) || I <- Is0], + Last = Fun(Last0), + Blk = Blk0#b_blk{is=Is,last=Last}, + Blocks = Blocks0#{L:=Blk}, + map_instrs_1(Ls, Fun, Blocks); +map_instrs_1([], _, Blocks) -> Blocks. + +flatmapfoldl(F, Accu0, [Hd|Tail]) -> + {R,Accu1} = F(Hd, Accu0), + {Rs,Accu2} = flatmapfoldl(F, Accu1, Tail), + {R++Rs,Accu2}; +flatmapfoldl(_, Accu, []) -> {[],Accu}. + +split_blocks_1([L|Ls], P, Blocks0, Count0) -> + #b_blk{is=Is0} = Blk = map_get(L, Blocks0), + case split_blocks_is(Is0, P, []) of + {yes,Bef,Aft} -> + NewLbl = Count0, + Count = Count0 + 1, + Br = #b_br{bool=#b_literal{val=true},succ=NewLbl,fail=NewLbl}, + BefBlk = Blk#b_blk{is=Bef,last=Br}, + NewBlk = Blk#b_blk{is=Aft}, + Blocks1 = Blocks0#{L:=BefBlk,NewLbl=>NewBlk}, + Successors = successors(NewBlk), + Blocks = update_phi_labels(Successors, L, NewLbl, Blocks1), + split_blocks_1([NewLbl|Ls], P, Blocks, Count); + no -> + split_blocks_1(Ls, P, Blocks0, Count0) + end; +split_blocks_1([], _, Blocks, Count) -> + {Blocks,Count}. + +split_blocks_is([I|Is], P, []) -> + split_blocks_is(Is, P, [I]); +split_blocks_is([I|Is], P, Acc) -> + case P(I) of + true -> + {yes,reverse(Acc),[I|Is]}; + false -> + split_blocks_is(Is, P, [I|Acc]) + end; +split_blocks_is([], _, _) -> no. + +update_phi_labels_is([#b_set{op=phi,args=Args0}=I0|Is], Old, New) -> + Args = [{Arg,rename_label(Lbl, Old, New)} || {Arg,Lbl} <- Args0], + I = I0#b_set{args=Args}, + [I|update_phi_labels_is(Is, Old, New)]; +update_phi_labels_is(Is, _, _) -> Is. + +rename_label(Old, Old, New) -> New; +rename_label(Lbl, _Old, _New) -> Lbl. + +used_args([#b_var{}=V|As]) -> + [V|used_args(As)]; +used_args([#b_remote{mod=Mod,name=Name}|As]) -> + used_args([Mod,Name|As]); +used_args([_|As]) -> + used_args(As); +used_args([]) -> []. + +used_1([H|T], Used0) -> + Used = ordsets:union(used(H), Used0), + used_1(T, Used); +used_1([], Used) -> Used. |