1%% -*- erlang-indent-level: 2 -*- 2%% 3%% Licensed under the Apache License, Version 2.0 (the "License"); 4%% you may not use this file except in compliance with the License. 5%% You may obtain a copy of the License at 6%% 7%% http://www.apache.org/licenses/LICENSE-2.0 8%% 9%% Unless required by applicable law or agreed to in writing, software 10%% distributed under the License is distributed on an "AS IS" BASIS, 11%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12%% See the License for the specific language governing permissions and 13%% limitations under the License. 14%% 15%% ========================================================================== 16%% Module : hipe_spillmin 17%% Purpose : Driver module for minimizing the number of stack slots used 18%% by a function. This is done using an algorithm for register 19%% allocation. The implementation is target-independent and 20%% requires a target-specific interface module as argument. 21%% ========================================================================== 22%% Exported functions (short description): 23%% 24%% stackalloc(CFG, StackSlots, SpillIndex, Options, TgtMod, TgtCtx, 25%% TempMap) -> 26%% {Coloring, NumberOfSpills} 27%% Takes a CFG and the TempMap from register allocation and returns 28%% a coloring of stack slots. 29%% StackSlots should be a list of used stack slots, usually empty at 30%% first call to function. 31%% SpillIndex is the the first position we will spill to, usually 0. 32%% TempMap is the TempMap from the register allocation 33%% 34%% The Coloring will be in the form of the "allocation datastructure" 35%% described below, that is, a list of tuples on the form 36%% {Name, {spill, SpillIndex}} 37%% The NumberOfSpills is either 0 indicating no spill or the 38%% SpillIndex of the last spilled register. 39%% 40%% mapmerge(Map, SpillMap) -> NewMap 41%% 42%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 43 44-module(hipe_spillmin). 45-export([stackalloc/7, stackalloc/8, mapmerge/2]). 46 47%%-define(DEBUG, 1). 48-define(HIPE_INSTRUMENT_COMPILER, true). 49 50%%--------------------------------------------------------------------------- 51 52-include("../main/hipe.hrl"). 53-include("../flow/cfg.hrl"). 54 55-type target_context() :: any(). 56 57%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 58%% 59%% stackalloc(CFG, StackSlots, SpillIndex, Options, Target, TempMap) 60%% Calculates an allocation of stack slots using either a linear scan 61%% or a graph coloring allocation algorithm. 62%% 63%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 64 65-spec stackalloc(#cfg{}, [_], non_neg_integer(), 66 comp_options(), module(), target_context(), hipe_temp_map()) -> 67 {hipe_spill_map(), non_neg_integer()}. 68 69stackalloc(CFG, StackSlots, SpillIndex, Options, TgtMod, TgtCtx, TempMap) -> 70 Liveness = TgtMod:analyze(CFG,TgtCtx), 71 stackalloc(CFG, Liveness, StackSlots, SpillIndex, Options, TgtMod, TgtCtx, TempMap). 72 73-spec stackalloc(#cfg{}, _, [_], non_neg_integer(), 74 comp_options(), module(), target_context(), hipe_temp_map()) -> 75 {hipe_spill_map(), non_neg_integer()}. 76 77stackalloc(CFG, Liveness, StackSlots, SpillIndex, Options, TgtMod, TgtCtx, 78 TempMap) -> 79 case proplists:get_bool(spillmin_color, Options) of 80 false -> 81 ?option_time(hipe_spillmin_scan:stackalloc( 82 CFG, Liveness, StackSlots, SpillIndex, Options, TgtMod, 83 TgtCtx, TempMap), 84 "Spill minimize, linear scan", Options); 85 true -> 86 ?option_time(hipe_spillmin_color:stackalloc( 87 CFG, Liveness, StackSlots, SpillIndex, Options, TgtMod, 88 TgtCtx, TempMap), 89 "Spill minimize, graph coloring", Options) 90 end. 91 92%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 93%% mapmerge(Map, SpillMap) 94%% 95%% stackalloc/6 will only return the subset of the tempmap that contains 96%% the spilled temporaries. This function is used to merge the old 97%% complete tempmap with the new spill information. 98%% Map is the old map (a list of [{R0, C1}, {R1, C2}, ...]). 99%% SpillMap is the new "spill" map. 100%% !! Warning, the function does not work with the maps in another order !! 101%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 102 103%% Combines the map with allocated spills with a map from the register 104%% allocator 105 106-spec mapmerge(hipe_map(), hipe_spill_map()) -> hipe_map(). 107 108mapmerge(TempMap, SpillMap) -> 109 mapmerge(TempMap, SpillMap, []). 110 111mapmerge([], _, Ack) -> 112 lists:reverse(Ack); 113mapmerge([{T1, _}|T1s], [{T2, C}|T2s], Ack) when T1 =:= T2 -> 114 mapmerge(T1s, T2s, [{T1, C}|Ack]); 115mapmerge([{_, unknown}|T1s], T2s, Ack) -> 116 mapmerge(T1s, T2s, Ack); 117mapmerge([T1|T1s], T2s, Ack) -> 118 mapmerge(T1s, T2s, [T1|Ack]). 119