diff options
Diffstat (limited to 'lib/hipe/icode')
| -rw-r--r-- | lib/hipe/icode/Makefile | 2 | ||||
| -rw-r--r-- | lib/hipe/icode/hipe_icode_call_elim.erl | 78 |
2 files changed, 79 insertions, 1 deletions
diff --git a/lib/hipe/icode/Makefile b/lib/hipe/icode/Makefile index a5edb10d90..c86562a981 100644 --- a/lib/hipe/icode/Makefile +++ b/lib/hipe/icode/Makefile @@ -59,7 +59,7 @@ DOC_MODULES = hipe_beam_to_icode \ hipe_icode_pp hipe_icode_primops \ hipe_icode_range \ hipe_icode_split_arith \ - hipe_icode_ssa hipe_icode_ssa_const_prop \ + hipe_icode_ssa hipe_icode_ssa_const_prop hipe_icode_call_elim \ hipe_icode_ssa_copy_prop hipe_icode_ssa_struct_reuse \ hipe_icode_type $(HIPE_MODULES) diff --git a/lib/hipe/icode/hipe_icode_call_elim.erl b/lib/hipe/icode/hipe_icode_call_elim.erl new file mode 100644 index 0000000000..6a22133962 --- /dev/null +++ b/lib/hipe/icode/hipe_icode_call_elim.erl @@ -0,0 +1,78 @@ +%% -*- erlang-indent-level: 2 -*- +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2016. 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% +%% +%%---------------------------------------------------------------------- +%% File : hipe_icode_call_elim.erl +%% Authors : Daniel S. McCain <[email protected]>, +%% Magnus Lång <[email protected]> +%% Created : 14 Apr 2014 by Magnus Lång <[email protected]> +%% Purpose : Eliminate calls to BIFs that are side-effect free only when +%% executed on some argument types. +%%---------------------------------------------------------------------- +-module(hipe_icode_call_elim). +-export([cfg/1]). + +-include("hipe_icode.hrl"). +-include("../flow/cfg.hrl"). + +-spec cfg(cfg()) -> cfg(). + +cfg(IcodeSSA) -> + lists:foldl(fun (Lbl, CFG1) -> + BB1 = hipe_icode_cfg:bb(CFG1, Lbl), + Code1 = hipe_bb:code(BB1), + Code2 = lists:map(fun elim_insn/1, Code1), + BB2 = hipe_bb:code_update(BB1, Code2), + hipe_icode_cfg:bb_add(CFG1, Lbl, BB2) + end, IcodeSSA, hipe_icode_cfg:labels(IcodeSSA)). + +-spec elim_insn(icode_instr()) -> icode_instr(). +elim_insn(Insn=#icode_call{'fun'={_,_,_}=MFA, args=Args, type=remote, + dstlist=[Dst=#icode_variable{ + annotation={type_anno, RetType, _}}]}) -> + Opaques = 'universe', + case erl_types:t_is_singleton(RetType, Opaques) of + true -> + ArgTypes = [case Arg of + #icode_variable{annotation={type_anno, Type, _}} -> Type; + #icode_const{} -> + erl_types:t_from_term(hipe_icode:const_value(Arg)) + end || Arg <- Args], + case can_be_eliminated(MFA, ArgTypes) of + true -> + Const = hipe_icode:mk_const( + erl_types:t_singleton_to_term(RetType, Opaques)), + #icode_move{dst=Dst, src=Const}; + false -> Insn + end; + false -> Insn + end; +elim_insn(Insn) -> Insn. + + +%% A function can be eliminated for some argument types if it has no side +%% effects when run on arguments of those types. + +-spec can_be_eliminated(mfa(), [erl_types:erl_type()]) -> boolean(). + +can_be_eliminated({maps, is_key, 2}, [_K, M]) -> + erl_types:t_is_map(M); +can_be_eliminated(_, _) -> + false. |