From b1726b022ad260497a1edc1cceb94935a06804e5 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?John=20H=C3=B6gberg?= Date: Wed, 19 Sep 2018 10:33:12 +0200 Subject: beam_ssa: Add helper functions and export more types get_anno/3: as get_anno but with a default value definitions/1-2: returns a map of variable definitions (#b_set{}) uses/1-2: returns a map of all uses of a given variable mapfold_blocks_rpo/4: mapfolds over blocks --- lib/compiler/src/beam_ssa.erl | 87 ++++++++++++++++++++++++++++++++++++++----- 1 file changed, 78 insertions(+), 9 deletions(-) (limited to 'lib/compiler/src') diff --git a/lib/compiler/src/beam_ssa.erl b/lib/compiler/src/beam_ssa.erl index 9d10d4aec3..6e0f5fffe3 100644 --- a/lib/compiler/src/beam_ssa.erl +++ b/lib/compiler/src/beam_ssa.erl @@ -20,12 +20,15 @@ %% Purpose: Type definitions and utilities for the SSA format. -module(beam_ssa). --export([add_anno/3,get_anno/2, - clobbers_xregs/1,def/2,def_used/2,dominators/1, +-export([add_anno/3,get_anno/2,get_anno/3, + clobbers_xregs/1,def/2,def_used/2, + definitions/1, + dominators/1, 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, @@ -35,14 +38,17 @@ split_blocks/3, successors/1,successors/2, trim_unreachable/1, - update_phi_labels/4,used/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]). + 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"). @@ -56,6 +62,9 @@ -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{}. @@ -76,6 +85,11 @@ -type anno() :: #{atom() := any()}. -type block_map() :: #{label():=b_blk()}. +-type dominator_map() :: #{label():=ordsets:ordset(label())}. +-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 @@ -103,14 +117,14 @@ %% Primops only used internally during code generation. -type cg_prim_op() :: 'bs_get' | 'bs_match_string' | 'bs_restore' | 'bs_skip' | -'copy' | 'put_tuple_arity' | 'put_tuple_element'. + 'copy' | 'put_tuple_arity' | 'put_tuple_element'. -import(lists, [foldl/3,keyfind/3,mapfoldl/3,member/2,reverse/1]). -spec add_anno(Key, Value, Construct) -> Construct when Key :: atom(), Value :: any(), - Construct :: b_function() | b_blk() | b_set() | terminator(). + Construct :: construct(). add_anno(Key, Val, #b_function{anno=Anno}=Bl) -> Bl#b_function{anno=Anno#{Key=>Val}}; @@ -125,11 +139,17 @@ add_anno(Key, Val, #b_ret{anno=Anno}=Bl) -> add_anno(Key, Val, #b_switch{anno=Anno}=Bl) -> Bl#b_switch{anno=Anno#{Key=>Val}}. --spec get_anno(atom(), b_blk()|b_set()|terminator()) -> any(). +-spec get_anno(atom(), construct()) -> any(). get_anno(Key, Construct) -> maps: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; @@ -169,6 +189,7 @@ no_side_effect(#b_set{op=Op}) -> bs_match -> true; bs_start_match -> true; bs_test_tail -> true; + bs_get_tail -> true; bs_put -> true; extract -> true; get_hd -> true; @@ -306,7 +327,7 @@ def_used(Ls, Blocks) -> -spec dominators(Blocks) -> Result when Blocks :: block_map(), - Result :: #{label():=ordsets:ordset(label())}. + Result :: dominator_map(). dominators(Blocks) -> Preds = predecessors(Blocks), @@ -327,6 +348,26 @@ 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 = maps:get(Lbl, Blocks0), + {Block, Acc} = Fun(Lbl, Block0, Acc0), + Blocks = maps:put(Lbl, Block, Blocks0), + {Blocks, Acc}. + -spec mapfold_instrs_rpo(Fun, From, Acc0, Blocks0) -> {Blocks,Acc} when Fun :: fun((b_blk()|terminator(), any()) -> any()), From :: [label()], @@ -442,7 +483,7 @@ rpo(From, Blocks) -> Ls. -spec rename_vars(Rename, [label()], block_map()) -> block_map() when - Rename :: [{var_name(),value()}] | #{var_name():=value()}. + Rename :: rename_map() | rename_proplist(). rename_vars(Rename, From, Blocks) when is_list(Rename) -> rename_vars(maps:from_list(Rename), From, Blocks); @@ -535,6 +576,34 @@ used(#b_switch{arg=#b_var{}=V}) -> [V]; used(_) -> []. +-spec definitions(Blocks :: block_map()) -> definition_map(). +definitions(Blocks) -> + beam_ssa:fold_instrs_rpo(fun(#b_set{ dst = Var }=I, Acc) -> + maps:put(Var, I, Acc); + (_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) -> + beam_ssa: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, beam_ssa:used(I)) + end, + F(Last, foldl(F, UseMap0, Is)). + %%% %%% Internal functions. %%% -- cgit v1.2.3