%---------------------------------------------------------------------------% % Copyright (C) 1994-2001 The University of Melbourne. % This file may only be copied under the terms of the GNU General % Public License - see the file COPYING in the Mercury distribution. %---------------------------------------------------------------------------% % % File: code_info.m % % Main authors: conway, zs. % % This file defines the code_info type and various operations on it. % The code_info structure is the 'state' of the code generator. % % This file is organized into nine submodules: % % - the code_info structure and its access predicates % - simple wrappers around access predicates % - handling branched control structures % - handling failure continuations % - handling liveness issues % - saving and restoring heap pointers, trail tickets etc % - interfacing to code_exprn % - managing the info required by garbage collection and value numbering % - managing stack slots % %---------------------------------------------------------------------------% :- module code_info. :- interface. :- import_module prog_data. :- import_module hlds_module, hlds_pred, hlds_goal, hlds_data, instmap. :- import_module code_model. :- import_module llds, continuation_info, trace. :- import_module globals. :- import_module bool, set, list, map, std_util, assoc_list, counter. :- implementation. :- import_module prog_out. :- import_module type_util, mode_util. :- import_module arg_info, code_util, code_exprn, exprn_aux, var_locn. :- import_module trace_params, llds_out. :- import_module options, tree. :- import_module term, varset. :- import_module set, stack. :- import_module string, require, char, bimap, int. %---------------------------------------------------------------------------% % Submodule for the code_info type and its access predicates. % % This submodule has the following components: % % declarations for exported access predicates % declarations for non-exported access predicates % the definition of the type and the init predicate % the definition of the get access predicates % the definition of the set access predicates % % Please keep the order of mention of the various fields % consistent in each of these five components. :- interface. :- type code_info. % Create a new code_info structure. Also return the % outermost resumption point, and info about the non-fixed % stack slots used for tracing purposes. :- pred code_info__init(bool::in, globals::in, pred_id::in, proc_id::in, proc_info::in, follow_vars::in, module_info::in, counter::in, resume_point_info::out, trace_slot_info::out, code_info::out) is det. % Get the globals table. :- pred code_info__get_globals(globals::out, code_info::in, code_info::out) is det. % Get the HLDS of the entire module. :- pred code_info__get_module_info(module_info::out, code_info::in, code_info::out) is det. % Get the id of the predicate we are generating code for. :- pred code_info__get_pred_id(pred_id::out, code_info::in, code_info::out) is det. % Get the id of the procedure we are generating code for. :- pred code_info__get_proc_id(proc_id::out, code_info::in, code_info::out) is det. % Get the HLDS of the procedure we are generating code for. :- pred code_info__get_proc_info(proc_info::out, code_info::in, code_info::out) is det. % Get the variables for the current procedure. :- pred code_info__get_varset(prog_varset::out, code_info::in, code_info::out) is det. :- pred code_info__get_maybe_trace_info(maybe(trace_info)::out, code_info::in, code_info::out) is det. % Get the set of currently forward-live variables. :- pred code_info__get_forward_live_vars(set(prog_var)::out, code_info::in, code_info::out) is det. % Set the set of currently forward-live variables. :- pred code_info__set_forward_live_vars(set(prog_var)::in, code_info::in, code_info::out) is det. % Get the table mapping variables to the current % instantiation states. :- pred code_info__get_instmap(instmap::out, code_info::in, code_info::out) is det. % Set the table mapping variables to the current % instantiation states. :- pred code_info__set_instmap(instmap::in, code_info::in, code_info::out) is det. % The number of the last local label allocated. :- pred code_info__get_label_counter(counter::out, code_info::in, code_info::out) is det. % The current value of the counter we use to give % each "create" rval its unique cell number, for use % in case the cell can be allocated statically. :- pred code_info__get_cell_counter(counter::out, code_info::in, code_info::out) is det. :- pred code_info__set_cell_counter(counter::in, code_info::in, code_info::out) is det. % Get the flag that indicates whether succip is used or not. :- pred code_info__get_succip_used(bool::out, code_info::in, code_info::out) is det. % Get the label layout information created by tracing % during code generation. :- pred code_info__get_layout_info(map(label, internal_layout_info)::out, code_info::in, code_info::out) is det. % Get the global static data structures that have % been created during code generation and which do % not have to be scanned by llds_common, since they % have no common parts by construction. :- pred code_info__get_closure_layouts(list(comp_gen_c_data)::out, code_info::in, code_info::out) is det. :- pred code_info__get_max_reg_in_use_at_trace(int::out, code_info::in, code_info::out) is det. :- pred code_info__set_max_reg_in_use_at_trace(int::in, code_info::in, code_info::out) is det. % Get the flag which is true iff the procedure has so far % emitted code that creates a temporary nondet stack frame. :- pred code_info__get_created_temp_frame(bool::out, code_info::in, code_info::out) is det. %---------------------------------------------------------------------------% :- implementation. :- pred code_info__get_var_slot_count(int::out, code_info::in, code_info::out) is det. :- pred code_info__set_maybe_trace_info(maybe(trace_info)::in, code_info::in, code_info::out) is det. :- pred code_info__get_zombies(set(prog_var)::out, code_info::in, code_info::out) is det. :- pred code_info__set_zombies(set(prog_var)::in, code_info::in, code_info::out) is det. :- pred code_info__get_var_locns_info(var_locns_info::out, code_info::in, code_info::out) is det. :- pred code_info__set_var_locns_info(var_locns_info::in, code_info::in, code_info::out) is det. :- pred code_info__get_temps_in_use(set(lval)::out, code_info::in, code_info::out) is det. :- pred code_info__set_temps_in_use(set(lval)::in, code_info::in, code_info::out) is det. :- pred code_info__get_fail_info(fail_info::out, code_info::in, code_info::out) is det. :- pred code_info__set_fail_info(fail_info::in, code_info::in, code_info::out) is det. :- pred code_info__set_label_counter(counter::in, code_info::in, code_info::out) is det. :- pred code_info__set_succip_used(bool::in, code_info::in, code_info::out) is det. :- pred code_info__set_layout_info(map(label, internal_layout_info)::in, code_info::in, code_info::out) is det. :- pred code_info__get_max_temp_slot_count(int::out, code_info::in, code_info::out) is det. :- pred code_info__set_max_temp_slot_count(int::in, code_info::in, code_info::out) is det. :- pred code_info__get_temp_content_map(map(lval, slot_contents)::out, code_info::in, code_info::out) is det. :- pred code_info__set_temp_content_map(map(lval, slot_contents)::in, code_info::in, code_info::out) is det. :- pred code_info__set_closure_layouts(list(comp_gen_c_data)::in, code_info::in, code_info::out) is det. :- pred code_info__get_closure_seq_counter(counter::out, code_info::in, code_info::out) is det. :- pred code_info__set_closure_seq_counter(counter::in, code_info::in, code_info::out) is det. :- pred code_info__set_created_temp_frame(bool::in, code_info::in, code_info::out) is det. %---------------------------------------------------------------------------% % The code_info structure has three groups of fields. % % Some fields are static; they are set when the code_info structure % is initialized, and never changed afterwards. % % Some fields record information about the state of the code generator % at a particular location in the HLDS code of the current procedure. % At the start of the branched control structure, the code generator % remembers the values of these fields, and starts generating code % for each branch from the same location-dependent state. % % Some fields record persistent information that does not depend % on a code location. Updates to these fields must remain effective % even when the code generator resets its location-dependent state. :- type code_info ---> code_info( code_info_static :: code_info_static, code_info_loc_dep :: code_info_loc_dep, code_info_persistent :: code_info_persistent ). :- type code_info_static ---> code_info_static( globals :: globals, % For the code generation options. module_info :: module_info, % The module_info structure - you just % never know when you might need it. pred_id :: pred_id, % The id of the current predicate. proc_id :: proc_id, % The id of the current procedure. proc_info :: proc_info, % The proc_info for the this procedure. varset :: prog_varset, % The variables in this procedure. var_slot_count :: int, % The number of stack slots allocated. % for storing variables. % (Some extra stack slots are used % for saving and restoring registers.) maybe_trace_info :: maybe(trace_info) % Information about which stack slots % the call sequence number and depth % are stored in, provided tracing is % switched on. ). :- type code_info_loc_dep ---> code_info_loc_dep( forward_live_vars :: set(prog_var), % Variables that are forward live % after this goal. instmap :: instmap, % Current insts of the live variables. zombies :: set(prog_var), % Zombie variables; variables that are not % forward live but which are protected by % an enclosing resume point. var_locns_info :: var_locns_info, % A map storing the information about % the status of each known variable. % (Known vars = forward live vars + zombies) temps_in_use :: set(lval), % The set of temporary locations currently in % use. These lvals must be all be keys in the % map of temporary locations ever used, which % is one of the persistent fields below. Any % keys in that map which are not in this set % are free for reuse. fail_info :: fail_info % Information about how to manage failures. ). :- type code_info_persistent ---> code_info_persistent( label_num_src :: counter, % Counter for the local labels used % by this procedure. cell_num_src :: counter, % Counter for cells in this proc. store_succip :: bool, % do we need to store succip? label_info :: map(label, internal_layout_info), % Information on which values % are live and where at which labels, % for tracing and/or accurate gc. stackslot_max :: int, % The maximum number of extra % temporary stackslots that have been % used during the procedure. temp_contents :: map(lval, slot_contents), % The temporary locations that have ever been % used on the stack, and what they contain. % Once we have used a stack slot to store % e.g. a ticket, we never reuse that slot % to hold something else, e.g. a saved hp. % This policy prevents us from making such % conflicting choices in parallel branches, % which would make it impossible to describe % to gc what the slot contains after the end % of the branched control structure. closure_layout_seq :: counter, closure_layouts :: list(comp_gen_c_data), % Closure layout structures generated by this % procedure. max_reg_used :: int, % At each call to MR_trace, we compute the % highest rN register number that contains % a useful value. This slot contains the % maximum of these highest values. Therefore % at all calls to MR_trace in the procedure, % we need only save the registers whose numbers % are equal to or smaller than this field. % This slot contains -1 if tracing is not % enabled. created_temp_frame:: bool % True iff the procedure has created one or % more temporary nondet frames. ). :- type var_locns_info ---> exprn_info(exprn_info) ; var_locn_info(var_locn_info). %---------------------------------------------------------------------------% code_info__init(SaveSuccip, Globals, PredId, ProcId, ProcInfo, FollowVars, ModuleInfo, CellCounter, ResumePoint, TraceSlotInfo, CodeInfo) :- proc_info_get_initial_instmap(ProcInfo, ModuleInfo, InstMap), proc_info_liveness_info(ProcInfo, Liveness), proc_info_headvars(ProcInfo, HeadVars), proc_info_arg_info(ProcInfo, ArgInfos), proc_info_interface_code_model(ProcInfo, CodeModel), assoc_list__from_corresponding_lists(HeadVars, ArgInfos, Args), arg_info__build_input_arg_list(Args, ArgList), proc_info_varset(ProcInfo, VarSet), proc_info_stack_slots(ProcInfo, StackSlots), globals__lookup_bool_option(Globals, lazy_code, LazyCode), globals__get_options(Globals, Options), globals__get_trace_level(Globals, TraceLevel), ( trace_level_is_none(TraceLevel) = no -> trace__fail_vars(ModuleInfo, ProcInfo, FailVars), MaybeFailVars = yes(FailVars), set__union(Liveness, FailVars, EffLiveness) ; MaybeFailVars = no, EffLiveness = Liveness ), ( LazyCode = yes, ArgRvalList = assoc_list__map_values( exprn_aux__var_lval_to_rval, ArgList), code_exprn__init_state(ArgRvalList, VarSet, StackSlots, FollowVars, Options, ExprnInfo), VarLocnsInfo = exprn_info(ExprnInfo) ; LazyCode = no, var_locn__init_state(ArgList, EffLiveness, VarSet, StackSlots, FollowVars, Options, VarLocnInfo), VarLocnsInfo = var_locn_info(VarLocnInfo) ), stack__init(ResumePoints), globals__lookup_bool_option(Globals, allow_hijacks, AllowHijack), ( AllowHijack = yes, Hijack = allowed ; AllowHijack = no, Hijack = not_allowed ), DummyFailInfo = fail_info(ResumePoints, resume_point_unknown, may_be_different, not_inside_non_condition, Hijack), map__init(TempContentMap), set__init(TempsInUse), set__init(Zombies), map__init(LayoutMap), code_info__max_var_slot(StackSlots, VarSlotMax), trace__reserved_slots(ModuleInfo, ProcInfo, Globals, FixedSlots, _), int__max(VarSlotMax, FixedSlots, SlotMax), CodeInfo0 = code_info( code_info_static( Globals, ModuleInfo, PredId, ProcId, ProcInfo, VarSet, SlotMax, no ), code_info_loc_dep( Liveness, InstMap, Zombies, VarLocnsInfo, TempsInUse, DummyFailInfo % code_info__init_fail_info % will override this dummy value ), code_info_persistent( counter__init(1), CellCounter, SaveSuccip, LayoutMap, 0, TempContentMap, counter__init(1), [], -1, no ) ), code_info__init_maybe_trace_info(TraceLevel, Globals, ProcInfo, ModuleInfo, TraceSlotInfo, CodeInfo0, CodeInfo1), code_info__init_fail_info(CodeModel, MaybeFailVars, ResumePoint, CodeInfo1, CodeInfo). :- pred code_info__init_maybe_trace_info(trace_level::in, globals::in, proc_info::in, module_info::in, trace_slot_info::out, code_info::in, code_info::out) is det. code_info__init_maybe_trace_info(TraceLevel, Globals, ProcInfo, ModuleInfo, TraceSlotInfo) --> ( { trace_level_is_none(TraceLevel) = no } -> trace__setup(ModuleInfo, ProcInfo, Globals, TraceSlotInfo, TraceInfo), code_info__set_maybe_trace_info(yes(TraceInfo)) ; { TraceSlotInfo = trace_slot_info(no, no, no, no, no, no) } ). %---------------------------------------------------------------------------% code_info__get_globals(CI^code_info_static^globals, CI, CI). code_info__get_module_info(CI^code_info_static^module_info, CI, CI). code_info__get_pred_id(CI^code_info_static^pred_id, CI, CI). code_info__get_proc_id(CI^code_info_static^proc_id, CI, CI). code_info__get_proc_info(CI^code_info_static^proc_info, CI, CI). code_info__get_varset(CI^code_info_static^varset, CI, CI). code_info__get_var_slot_count(CI^code_info_static^var_slot_count, CI, CI). code_info__get_maybe_trace_info(CI^code_info_static^maybe_trace_info, CI, CI). code_info__get_forward_live_vars(CI^code_info_loc_dep^forward_live_vars, CI, CI). code_info__get_instmap(CI^code_info_loc_dep^instmap, CI, CI). code_info__get_zombies(CI^code_info_loc_dep^zombies, CI, CI). code_info__get_var_locns_info(CI^code_info_loc_dep^var_locns_info, CI, CI). code_info__get_temps_in_use(CI^code_info_loc_dep^temps_in_use, CI, CI). code_info__get_fail_info(CI^code_info_loc_dep^fail_info, CI, CI). code_info__get_label_counter(CI^code_info_persistent^label_num_src, CI, CI). code_info__get_cell_counter(CI^code_info_persistent^cell_num_src, CI, CI). code_info__get_succip_used(CI^code_info_persistent^store_succip, CI, CI). code_info__get_layout_info(CI^code_info_persistent^label_info, CI, CI). code_info__get_max_temp_slot_count(CI^code_info_persistent^stackslot_max, CI, CI). code_info__get_temp_content_map(CI^code_info_persistent^temp_contents, CI, CI). code_info__get_closure_seq_counter(CI^code_info_persistent^closure_layout_seq, CI, CI). code_info__get_closure_layouts(CI^code_info_persistent^closure_layouts, CI, CI). code_info__get_max_reg_in_use_at_trace(CI^code_info_persistent^max_reg_used, CI, CI). code_info__get_created_temp_frame(CI^code_info_persistent^created_temp_frame, CI, CI). %---------------------------------------------------------------------------% code_info__set_maybe_trace_info(TI, CI, CI^code_info_static^maybe_trace_info := TI). code_info__set_forward_live_vars(LV, CI, CI^code_info_loc_dep^forward_live_vars := LV). code_info__set_instmap(IM, CI, CI^code_info_loc_dep^instmap := IM). code_info__set_zombies(Zs, CI, CI^code_info_loc_dep^zombies := Zs). code_info__set_var_locns_info(EI, CI, CI^code_info_loc_dep^var_locns_info := EI). code_info__set_temps_in_use(TI, CI, CI^code_info_loc_dep^temps_in_use := TI). code_info__set_fail_info(FI, CI, CI^code_info_loc_dep^fail_info := FI). code_info__set_label_counter(LC, CI, CI^code_info_persistent^label_num_src := LC). code_info__set_cell_counter(CC, CI, CI^code_info_persistent^cell_num_src := CC). code_info__set_succip_used(SU, CI, CI^code_info_persistent^store_succip := SU). code_info__set_layout_info(LI, CI, CI^code_info_persistent^label_info := LI). code_info__set_max_temp_slot_count(TM, CI, CI^code_info_persistent^stackslot_max := TM). code_info__set_temp_content_map(CM, CI, CI^code_info_persistent^temp_contents := CM). code_info__set_closure_seq_counter(CLS, CI, CI^code_info_persistent^closure_layout_seq := CLS). code_info__set_closure_layouts(CG, CI, CI^code_info_persistent^closure_layouts := CG). code_info__set_max_reg_in_use_at_trace(MR, CI, CI^code_info_persistent^max_reg_used := MR). code_info__set_created_temp_frame(MR, CI, CI^code_info_persistent^created_temp_frame := MR). %---------------------------------------------------------------------------% %---------------------------------------------------------------------------% % Submodule for simple wrappers around access predicates. :- interface. % Get the hlds mapping from variables to stack slots :- pred code_info__get_stack_slots(stack_slots, code_info, code_info). :- mode code_info__get_stack_slots(out, in, out) is det. % Get the table that contains advice about where % variables should be put. :- pred code_info__get_follow_var_map(follow_vars_map, code_info, code_info). :- mode code_info__get_follow_var_map(out, in, out) is det. % Get the integer that gives the number of the next % non-reserved register. :- pred code_info__get_next_non_reserved(int, code_info, code_info). :- mode code_info__get_next_non_reserved(out, in, out) is det. % Set the table that contains advice about where % variables should be put. :- pred code_info__set_follow_vars(follow_vars, code_info, code_info). :- mode code_info__set_follow_vars(in, in, out) is det. % code_info__pre_goal_update(GoalInfo, Atomic, OldCodeInfo, NewCodeInfo) % updates OldCodeInfo to produce NewCodeInfo with the changes % specified by GoalInfo. :- pred code_info__pre_goal_update(hlds_goal_info, bool, code_info, code_info). :- mode code_info__pre_goal_update(in, in, in, out) is det. % code_info__post_goal_update(GoalInfo, OldCodeInfo, NewCodeInfo) % updates OldCodeInfo to produce NewCodeInfo with the changes described % by GoalInfo. :- pred code_info__post_goal_update(hlds_goal_info, code_info, code_info). :- mode code_info__post_goal_update(in, in, out) is det. % Find out whether the body of the current procedure should use % typeinfo liveness. :- pred code_info__body_typeinfo_liveness(bool::out, code_info::in, code_info::out) is det. % Find out the type of the given variable. :- pred code_info__variable_type(prog_var, type, code_info, code_info). :- mode code_info__variable_type(in, out, in, out) is det. :- pred code_info__lookup_type_defn(type, hlds_type_defn, code_info, code_info). :- mode code_info__lookup_type_defn(in, out, in, out) is det. % Given a constructor id, and a variable (so that we can work out the % type of the constructor), determine correct tag (representation) % of that constructor. :- pred code_info__cons_id_to_tag(prog_var, cons_id, cons_tag, code_info, code_info). :- mode code_info__cons_id_to_tag(in, in, out, in, out) is det. % Get the code model of the current procedure. :- pred code_info__get_proc_model(code_model, code_info, code_info). :- mode code_info__get_proc_model(out, in, out) is det. % Get the list of the head variables of the current procedure. :- pred code_info__get_headvars(list(prog_var), code_info, code_info). :- mode code_info__get_headvars(out, in, out) is det. % Get the call argument information for the current procedure :- pred code_info__get_arginfo(list(arg_info), code_info, code_info). :- mode code_info__get_arginfo(out, in, out) is det. % Get the call argument info for a given mode of a given predicate :- pred code_info__get_pred_proc_arginfo(pred_id, proc_id, list(arg_info), code_info, code_info). :- mode code_info__get_pred_proc_arginfo(in, in, out, in, out) is det. % Get the set of variables currently needed by the resume % points of enclosing goals. :- pred code_info__current_resume_point_vars(set(prog_var), code_info, code_info). :- mode code_info__current_resume_point_vars(out, in, out) is det. :- pred code_info__variable_to_string(prog_var, string, code_info, code_info). :- mode code_info__variable_to_string(in, out, in, out) is det. % Create a code address which holds the address of the specified % procedure. % The fourth argument should be `no' if the the caller wants the % returned address to be valid from everywhere in the program. % If being valid from within the current procedure is enough, % this argument should be `yes' wrapped around the value of the % --procs-per-c-function option and the current procedure id. % Using an address that is only valid from within the current % procedure may make jumps more efficient. % % If the procs_per_c_function option tells us to put more than one % procedure into each C function, but not all procedures in the module % are in one function, then we would like to be able to use the % fast form of reference to a procedure for references not only from % within the same procedure but also from other procedures within % the same C function. However, at the time of code generation, % we do not yet know which procedures will be put into the same % C functions, and so we cannot do this. :- pred code_info__make_entry_label(module_info, pred_id, proc_id, bool, code_addr, code_info, code_info). :- mode code_info__make_entry_label(in, in, in, in, out, in, out) is det. % Generate the next local label in sequence. :- pred code_info__get_next_label(label, code_info, code_info). :- mode code_info__get_next_label(out, in, out) is det. % Generate the next cell number in sequence. :- pred code_info__get_next_cell_number(int, code_info, code_info). :- mode code_info__get_next_cell_number(out, in, out) is det. % Note that the succip slot is used, and thus cannot be % optimized away. :- pred code_info__succip_is_used(code_info, code_info). :- mode code_info__succip_is_used(in, out) is det. :- pred code_info__add_trace_layout_for_label(label, term__context, trace_port, goal_path, layout_label_info, code_info, code_info). :- mode code_info__add_trace_layout_for_label(in, in, in,in, in, in, out) is det. :- pred code_info__get_cur_proc_label(proc_label, code_info, code_info). :- mode code_info__get_cur_proc_label(out, in, out) is det. :- pred code_info__get_next_closure_seq_no(int, code_info, code_info). :- mode code_info__get_next_closure_seq_no(out, in, out) is det. :- pred code_info__add_closure_layout(comp_gen_c_data, code_info, code_info). :- mode code_info__add_closure_layout(in, in, out) is det. %---------------------------------------------------------------------------% :- implementation. :- pred code_info__add_resume_layout_for_label(label, layout_label_info, code_info, code_info). :- mode code_info__add_resume_layout_for_label(in, in, in, out) is det. code_info__get_stack_slots(StackSlots, CI, CI) :- code_info__get_var_locns_info(VarInfo, CI, _), ( VarInfo = exprn_info(ExprnInfo), code_exprn__get_stack_slots(StackSlots, ExprnInfo, _) ; VarInfo = var_locn_info(VarLocnInfo), var_locn__get_stack_slots(StackSlots, VarLocnInfo, _) ). code_info__get_follow_var_map(FollowVarMap, CI, CI) :- code_info__get_var_locns_info(VarInfo, CI, _), ( VarInfo = exprn_info(ExprnInfo), code_exprn__get_follow_vars(FollowVars, ExprnInfo, _), FollowVars = follow_vars(FollowVarMap, _) ; VarInfo = var_locn_info(VarLocnInfo), var_locn__get_follow_var_map(FollowVarMap, VarLocnInfo, _) ). code_info__get_next_non_reserved(NextNonReserved, CI, CI) :- code_info__get_var_locns_info(VarInfo, CI, _), ( VarInfo = exprn_info(ExprnInfo), code_exprn__get_follow_vars(FollowVars, ExprnInfo, _), FollowVars = follow_vars(_, NextNonReserved) ; VarInfo = var_locn_info(VarLocnInfo), var_locn__get_next_non_reserved(NextNonReserved, VarLocnInfo, _) ). code_info__set_follow_vars(FollowVars, CI0, CI) :- code_info__get_var_locns_info(VarInfo0, CI0, _), ( VarInfo0 = exprn_info(ExprnInfo0), code_exprn__set_follow_vars(FollowVars, ExprnInfo0, ExprnInfo), VarInfo = exprn_info(ExprnInfo) ; VarInfo0 = var_locn_info(VarLocnInfo0), var_locn__set_follow_vars(FollowVars, VarLocnInfo0, VarLocnInfo), VarInfo = var_locn_info(VarLocnInfo) ), code_info__set_var_locns_info(VarInfo, CI0, CI). %-----------------------------------------------------------------------------% % Update the code info structure to be consistent % immediately prior to generating a goal. code_info__pre_goal_update(GoalInfo, Atomic) --> % The liveness pass puts resume_point annotations on some kinds % of goals. The parts of the code generator that handle those kinds % of goals should handle the resume point annotation as well; % when they do, they remove the annotation. The following code % is a sanity check to make sure that this has in fact been done. { goal_info_get_resume_point(GoalInfo, ResumePoint) }, ( { ResumePoint = no_resume_point } ; { ResumePoint = resume_point(_, _) }, { error("pre_goal_update with resume point") } ), { goal_info_get_follow_vars(GoalInfo, MaybeFollowVars) }, ( { MaybeFollowVars = yes(FollowVars) }, code_info__set_follow_vars(FollowVars) ; { MaybeFollowVars = no } ), % note: we must be careful to apply deaths before births { goal_info_get_pre_deaths(GoalInfo, PreDeaths) }, code_info__rem_forward_live_vars(PreDeaths), code_info__maybe_make_vars_forward_dead(PreDeaths, no), { goal_info_get_pre_births(GoalInfo, PreBirths) }, code_info__add_forward_live_vars(PreBirths), ( { Atomic = yes } -> { goal_info_get_post_deaths(GoalInfo, PostDeaths) }, code_info__rem_forward_live_vars(PostDeaths) ; [] ). % Update the code info structure to be consistent % immediately after generating a goal. code_info__post_goal_update(GoalInfo) --> % note: we must be careful to apply deaths before births { goal_info_get_post_deaths(GoalInfo, PostDeaths) }, code_info__rem_forward_live_vars(PostDeaths), code_info__maybe_make_vars_forward_dead(PostDeaths, no), { goal_info_get_post_births(GoalInfo, PostBirths) }, code_info__add_forward_live_vars(PostBirths), code_info__make_vars_forward_live(PostBirths), { goal_info_get_instmap_delta(GoalInfo, InstMapDelta) }, code_info__get_instmap(InstMap0), { instmap__apply_instmap_delta(InstMap0, InstMapDelta, InstMap) }, code_info__set_instmap(InstMap). %---------------------------------------------------------------------------% code_info__body_typeinfo_liveness(TypeInfoLiveness) --> code_info__get_module_info(ModuleInfo), code_info__get_pred_id(PredId), { module_info_pred_info(ModuleInfo, PredId, PredInfo) }, code_info__get_globals(Globals), { body_should_use_typeinfo_liveness(PredInfo, Globals, TypeInfoLiveness) }. :- pred code_info__get_var_types(map(prog_var, type), code_info, code_info). :- mode code_info__get_var_types(out, in, out) is det. code_info__get_var_types(VarTypes) --> code_info__get_proc_info(ProcInfo), { proc_info_vartypes(ProcInfo, VarTypes) }. code_info__variable_type(Var, Type) --> code_info__get_var_types(VarTypes), { map__lookup(VarTypes, Var, Type) }. code_info__lookup_type_defn(Type, TypeDefn) --> code_info__get_module_info(ModuleInfo), { type_to_type_id(Type, TypeIdPrime, _) -> TypeId = TypeIdPrime ; error("unknown type in code_info__lookup_type_defn") }, { module_info_types(ModuleInfo, TypeTable) }, { map__lookup(TypeTable, TypeId, TypeDefn) }. code_info__cons_id_to_tag(Var, ConsId, ConsTag) --> code_info__variable_type(Var, Type), code_info__get_module_info(ModuleInfo), { code_util__cons_id_to_tag(ConsId, Type, ModuleInfo, ConsTag) }. %---------------------------------------------------------------------------% code_info__get_proc_model(CodeModel) --> code_info__get_proc_info(ProcInfo), { proc_info_interface_code_model(ProcInfo, CodeModel) }. code_info__get_headvars(HeadVars) --> code_info__get_module_info(ModuleInfo), code_info__get_pred_id(PredId), code_info__get_proc_id(ProcId), { module_info_pred_proc_info(ModuleInfo, PredId, ProcId, _, ProcInfo) }, { proc_info_headvars(ProcInfo, HeadVars) }. code_info__get_arginfo(ArgInfo) --> code_info__get_pred_id(PredId), code_info__get_proc_id(ProcId), code_info__get_pred_proc_arginfo(PredId, ProcId, ArgInfo). code_info__get_pred_proc_arginfo(PredId, ProcId, ArgInfo) --> code_info__get_module_info(ModuleInfo), { module_info_pred_proc_info(ModuleInfo, PredId, ProcId, _, ProcInfo) }, { proc_info_arg_info(ProcInfo, ArgInfo) }. code_info__current_resume_point_vars(ResumeVars) --> code_info__get_fail_info(FailInfo), { FailInfo = fail_info(ResumePointStack, _, _, _, _) }, { stack__top_det(ResumePointStack, ResumePointInfo) }, { code_info__pick_first_resume_point(ResumePointInfo, ResumeMap, _) }, { map__keys(ResumeMap, ResumeMapVarList) }, { set__list_to_set(ResumeMapVarList, ResumeVars) }. code_info__variable_to_string(Var, Name) --> code_info__get_varset(Varset), { varset__lookup_name(Varset, Var, Name) }. %---------------------------------------------------------------------------% code_info__make_entry_label(ModuleInfo, PredId, ProcId, Immed0, PredAddress) --> ( { Immed0 = no }, { Immed = no } ; { Immed0 = yes }, code_info__get_globals(Globals), { globals__lookup_int_option(Globals, procs_per_c_function, ProcsPerFunc) }, code_info__get_pred_id(CurPredId), code_info__get_proc_id(CurProcId), { Immed = yes(ProcsPerFunc - proc(CurPredId, CurProcId)) } ), { code_util__make_entry_label(ModuleInfo, PredId, ProcId, Immed, PredAddress) }. code_info__get_next_label(Label) --> code_info__get_module_info(ModuleInfo), code_info__get_pred_id(PredId), code_info__get_proc_id(ProcId), code_info__get_label_counter(C0), { counter__allocate(N, C0, C) }, code_info__set_label_counter(C), { code_util__make_internal_label(ModuleInfo, PredId, ProcId, N, Label) }. code_info__get_next_cell_number(N) --> code_info__get_cell_counter(C0), { counter__allocate(N, C0, C) }, code_info__set_cell_counter(C). code_info__succip_is_used --> code_info__set_succip_used(yes). code_info__add_trace_layout_for_label(Label, Context, Port, Path, Layout) --> code_info__get_layout_info(Internals0), { Exec = yes(trace_port_layout_info(Context, Port, Path, Layout)) }, { map__search(Internals0, Label, Internal0) -> Internal0 = internal_layout_info(Exec0, Resume, Return), ( Exec0 = no -> true ; error("adding trace layout for already known label") ), Internal = internal_layout_info(Exec, Resume, Return), map__set(Internals0, Label, Internal, Internals) ; Internal = internal_layout_info(Exec, no, no), map__det_insert(Internals0, Label, Internal, Internals) }, code_info__set_layout_info(Internals). code_info__add_resume_layout_for_label(Label, LayoutInfo) --> code_info__get_layout_info(Internals0), { Resume = yes(LayoutInfo) }, { map__search(Internals0, Label, Internal0) -> Internal0 = internal_layout_info(Exec, Resume0, Return), ( Resume0 = no -> true ; error("adding gc layout for already known label") ), Internal = internal_layout_info(Exec, Resume, Return), map__set(Internals0, Label, Internal, Internals) ; Internal = internal_layout_info(no, Resume, no), map__det_insert(Internals0, Label, Internal, Internals) }, code_info__set_layout_info(Internals). :- pred code_info__get_active_temps_data(assoc_list(lval, slot_contents), code_info, code_info). :- mode code_info__get_active_temps_data(out, in, out) is det. code_info__get_active_temps_data(Temps) --> code_info__get_temps_in_use(TempsInUse), code_info__get_temp_content_map(TempContentMap), { map__select(TempContentMap, TempsInUse, TempsInUseContentMap) }, { map__to_assoc_list(TempsInUseContentMap, Temps) }. code_info__get_cur_proc_label(ProcLabel) --> code_info__get_module_info(ModuleInfo), code_info__get_pred_id(PredId), code_info__get_proc_id(ProcId), { code_util__make_proc_label(ModuleInfo, PredId, ProcId, ProcLabel) }. code_info__get_next_closure_seq_no(SeqNo) --> code_info__get_closure_seq_counter(C0), { counter__allocate(SeqNo, C0, C) }, code_info__set_closure_seq_counter(C). code_info__add_closure_layout(ClosureLayout) --> code_info__get_closure_layouts(ClosureLayouts), code_info__set_closure_layouts([ClosureLayout | ClosureLayouts]). %---------------------------------------------------------------------------% %---------------------------------------------------------------------------% % Submodule for handling branched control structures. :- interface. :- type position_info. :- type branch_end_info. :- type branch_end == maybe(branch_end_info). :- pred code_info__remember_position(position_info, code_info, code_info). :- mode code_info__remember_position(out, in, out) is det. :- pred code_info__reset_to_position(position_info, code_info, code_info). :- mode code_info__reset_to_position(in, in, out) is det. :- pred code_info__reset_resume_known(position_info, code_info, code_info). :- mode code_info__reset_resume_known(in, in, out) is det. :- pred code_info__generate_branch_end(store_map, branch_end, branch_end, code_tree, code_info, code_info). :- mode code_info__generate_branch_end(in, in, out, out, in, out) is det. :- pred code_info__after_all_branches(store_map, branch_end, code_info, code_info). :- mode code_info__after_all_branches(in, in, in, out) is det. :- pred code_info__save_hp_in_branch(code_tree, lval, position_info, position_info). :- mode code_info__save_hp_in_branch(out, out, in, out) is det. :- implementation. :- type position_info ---> position_info( code_info % The code_info at a given position % in the code of the procedure. ). :- type branch_end_info ---> branch_end_info( code_info % The code_info at the end of a branch. ). code_info__remember_position(position_info(C), C, C). code_info__reset_to_position(position_info(PosCI), CurCI, NextCI) :- PosCI = code_info(_, LocDep, _), CurCI = code_info(Static, _, Persistent), NextCI = code_info(Static, LocDep, Persistent). code_info__reset_resume_known(BranchStart) --> { BranchStart = position_info(BranchStartCI) }, { code_info__get_fail_info(BranchStartFailInfo, BranchStartCI, _) }, { BranchStartFailInfo = fail_info(_, BSResumeKnown, _, _, _) }, code_info__get_fail_info(CurFailInfo), { CurFailInfo = fail_info(CurFailStack, _, CurCurfMaxfr, CurCondEnv, CurHijack) }, { NewFailInfo = fail_info(CurFailStack, BSResumeKnown, CurCurfMaxfr, CurCondEnv, CurHijack) }, code_info__set_fail_info(NewFailInfo). code_info__generate_branch_end(StoreMap, MaybeEnd0, MaybeEnd, Code) --> { map__to_assoc_list(StoreMap, VarLocs) }, code_info__get_var_locns_info(VarInfo), ( { VarInfo = exprn_info(_) } ; % The eager code generator generates better code % if it knows in advance where each variable should % go. We don't need to reset the follow_vars % afterwards, since every goal following a branched % control structure must in any case be annotated with % its own follow_var set. { VarInfo = var_locn_info(_) }, { map__from_assoc_list(VarLocs, FollowVarsMap) }, { assoc_list__values(VarLocs, Locs) }, { code_util__max_mentioned_reg(Locs, MaxMentionedReg) }, code_info__set_follow_vars(follow_vars(FollowVarsMap, MaxMentionedReg + 1)) ), code_info__place_vars(VarLocs, Code), =(EndCodeInfo1), { MaybeEnd0 = no, EndCodeInfo = EndCodeInfo1 ; MaybeEnd0 = yes(branch_end_info(EndCodeInfo0)), % Make sure the left context we leave the % branched structure with is valid for all branches. code_info__get_fail_info(FailInfo0, EndCodeInfo0, _), code_info__get_fail_info(FailInfo1, EndCodeInfo1, _), FailInfo0 = fail_info(_, ResumeKnown0, CurfrMaxfr0, CondEnv0, Hijack0), FailInfo1 = fail_info(R, ResumeKnown1, CurfrMaxfr1, CondEnv1, Hijack1), ( ResumeKnown0 = resume_point_known(Redoip0), ResumeKnown1 = resume_point_known(Redoip1) -> ResumeKnown = resume_point_known(Redoip0), require(unify(Redoip0, Redoip1), "redoip mismatch in generate_branch_end") ; ResumeKnown = resume_point_unknown ), ( CurfrMaxfr0 = must_be_equal, CurfrMaxfr1 = must_be_equal -> CurfrMaxfr = must_be_equal ; CurfrMaxfr = may_be_different ), ( Hijack0 = allowed, Hijack1 = allowed -> Hijack = allowed ; Hijack = not_allowed ), require(unify(CondEnv0, CondEnv1), "some but not all branches inside a non condition"), FailInfo = fail_info(R, ResumeKnown, CurfrMaxfr, CondEnv0, Hijack), code_info__set_fail_info(FailInfo, EndCodeInfo1, EndCodeInfoA), % Make sure the "temps in use" set at the end of the % branched control structure includes every slot % in use at the end of any branch. code_info__get_temps_in_use(TempsInUse0, EndCodeInfo0, _), code_info__get_temps_in_use(TempsInUse1, EndCodeInfo1, _), set__union(TempsInUse0, TempsInUse1, TempsInUse), code_info__set_temps_in_use(TempsInUse, EndCodeInfoA, EndCodeInfo) }, { MaybeEnd = yes(branch_end_info(EndCodeInfo)) }. code_info__after_all_branches(StoreMap, MaybeEnd, CI0, CI) :- ( MaybeEnd = yes(BranchEnd), BranchEnd = branch_end_info(BranchEndCodeInfo), code_info__reset_to_position(position_info(BranchEndCodeInfo), CI0, CI1), code_info__remake_with_store_map(StoreMap, CI1, CI) ; MaybeEnd = no, error("no branches in branched control structure") ). % code_info__remake_with_store_map throws away the var_info data % structure, forgetting the current locations of all variables, % and rebuilds it from scratch based on the given store map. % The new var_info will know about only the variables present % in the store map, and will believe they are where the store map % says they are. :- pred code_info__remake_with_store_map(store_map, code_info, code_info). :- mode code_info__remake_with_store_map(in, in, out) is det. code_info__remake_with_store_map(StoreMap) --> { map__to_assoc_list(StoreMap, VarLvals) }, code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(Exprn0), VarRvals = assoc_list__map_values(exprn_aux__var_lval_to_rval, VarLvals), code_exprn__reinit_state(VarRvals, Exprn0, Exprn), VarInfo = exprn_info(Exprn) ; VarInfo0 = var_locn_info(VarLocnInfo0), var_locn__reinit_state(VarLvals, VarLocnInfo0, VarLocnInfo), VarInfo = var_locn_info(VarLocnInfo) }, code_info__set_var_locns_info(VarInfo). code_info__save_hp_in_branch(Code, Slot, Pos0, Pos) :- Pos0 = position_info(CodeInfo0), code_info__save_hp(Code, Slot, CodeInfo0, CodeInfo), Pos = position_info(CodeInfo). %---------------------------------------------------------------------------% %---------------------------------------------------------------------------% % Submodule for the handling of failure continuations. % The principles underlying this submodule of code_info.m are % documented in the file compiler/notes/failure.html, which also % defines terms such as "quarter hijack"). Some parts of the submodule % also require knowledge of compiler/notes/allocation.html. :- interface. :- type resume_map. :- type resume_point_info. % `prepare_for_disj_hijack' should be called before entering % a disjunction. It saves the values of any nondet stack slots % the disjunction may hijack, and if necessary, sets the redofr % slot of the top frame to point to this frame. The code at the % start of the individual disjuncts will override the redoip slot. % % `undo_disj_hijack' should be called before entering the last % disjunct of a disjunction. It undoes the effects of % `prepare_for_disj_hijack'. :- type disj_hijack_info. :- pred code_info__prepare_for_disj_hijack(code_model::in, disj_hijack_info::out, code_tree::out, code_info::in, code_info::out) is det. :- pred code_info__undo_disj_hijack(disj_hijack_info::in, code_tree::out, code_info::in, code_info::out) is det. % `prepare_for_ite_hijack' should be called before entering % an if-then-else. It saves the values of any nondet stack slots % the if-then-else may hijack, and if necessary, sets the redofr % slot of the top frame to point to this frame. Our caller % will then override the redoip slot to point to the start of % the else part before generating the code of the condition. % % `ite_enter_then', which should be called generating code for % the condition, sets up the failure state of the code generator % for generating the then-part, and returns the code sequences % to be used at the starts of the then-part and the else-part % to undo the effects of any hijacking. :- type ite_hijack_info. :- pred code_info__prepare_for_ite_hijack(code_model::in, ite_hijack_info::out, code_tree::out, code_info::in, code_info::out) is det. :- pred code_info__ite_enter_then(ite_hijack_info::in, code_tree::out, code_tree::out, code_info::in, code_info::out) is det. % `enter_simple_neg' and `leave_simple_neg' should be called before % and after generating the code for a negated unification, in % situations where failure is a direct branch. We handle this case % specially, because it occurs frequently and should not require % a flushing of the expression cache, whereas the general way of % handling negations does require a flush. These two predicates % handle all aspects of the negation except for the unification % itself. :- type simple_neg_info. :- pred code_info__enter_simple_neg(set(prog_var)::in, hlds_goal_info::in, simple_neg_info::out, code_info::in, code_info::out) is det. :- pred code_info__leave_simple_neg(hlds_goal_info::in, simple_neg_info::in, code_info::in, code_info::out) is det. % `prepare_for_det_commit' and `generate_det_commit' should be % called before and after generating the code for the multi goal % being cut across. If the goal succeeds, the commit will cut % any choice points generated in the goal. :- type det_commit_info. :- pred code_info__prepare_for_det_commit(det_commit_info::out, code_tree::out, code_info::in, code_info::out) is det. :- pred code_info__generate_det_commit(det_commit_info::in, code_tree::out, code_info::in, code_info::out) is det. % `prepare_for_semi_commit' and `generate_semi_commit' should be % called before and after generating the code for the nondet goal % being cut across. If the goal succeeds, the commit will cut % any choice points generated in the goal. :- type semi_commit_info. :- pred code_info__prepare_for_semi_commit(semi_commit_info::out, code_tree::out, code_info::in, code_info::out) is det. :- pred code_info__generate_semi_commit(semi_commit_info::in, code_tree::out, code_info::in, code_info::out) is det. % Put the given resume point into effect, by pushing it on to % the resume point stack, and if necessary generating code to % override the redoip of the top nondet stack frame. :- pred code_info__effect_resume_point(resume_point_info::in, code_model::in, code_tree::out, code_info::in, code_info::out) is det. :- pred code_info__pop_resume_point(code_info::in, code_info::out) is det. % Return the details of the resume point currently on top of the % failure continuation stack. :- pred code_info__top_resume_point(resume_point_info::out, code_info::in, code_info::out) is det. % Call this predicate to say "we have just left a disjunction; % we don't know what address the following code will need to % backtrack to". :- pred code_info__set_resume_point_to_unknown(code_info::in, code_info::out) is det. % Call this predicate to say "we have just returned a model_non call; % we don't know what address the following code will need to % backtrack to, and there may now be nondet frames on top of ours % that do not have their redofr slots pointing to our frame". :- pred code_info__set_resume_point_and_frame_to_unknown(code_info::in, code_info::out) is det. % Generate code for executing a failure that is appropriate for the % current failure environment. :- pred code_info__generate_failure(code_tree::out, code_info::in, code_info::out) is det. % Generate code that checks if the given rval is false, and if yes, % executes a failure that is appropriate for the current failure % environment. :- pred code_info__fail_if_rval_is_false(rval::in, code_tree::out, code_info::in, code_info::out) is det. % Checks whether the appropriate code for failure in the current % failure environment is a direct branch. :- pred code_info__failure_is_direct_branch(code_addr::out, code_info::in, code_info::out) is semidet. % Checks under what circumstances the current failure environment % would allow a model_non call at this point to be turned into a % tail call, provided of course that the return from the call is % followed immediately by succeed(). :- pred code_info__may_use_nondet_tailcall(nondet_tail_call::out, code_info::in, code_info::out) is det. % Materialize the given variables into registers or stack slots. :- pred code_info__produce_vars(set(prog_var)::in, resume_map::out, code_tree::out, code_info::in, code_info::out) is det. % Put the variables needed in enclosing failure continuations % into their stack slots. :- pred code_info__flush_resume_vars_to_stack(code_tree::out, code_info::in, code_info::out) is det. % Set up the resume_point_info structure. :- pred code_info__make_resume_point(set(prog_var)::in, resume_locs::in, resume_map::in, resume_point_info::out, code_info::in, code_info::out) is det. % Generate the code for a resume point. :- pred code_info__generate_resume_point(resume_point_info::in, code_tree::out, code_info::in, code_info::out) is det. % List the variables that need to be preserved for the given % resume point. :- pred code_info__resume_point_vars(resume_point_info::in, list(prog_var)::out) is det. % See whether the given resume point includes a code address % that presumes all the resume point variables to be in their % stack slots. If yes, return that code address; otherwise, % abort the compiler. :- pred code_info__resume_point_stack_addr(resume_point_info::in, code_addr::out) is det. %---------------------------------------------------------------------------% :- implementation. % The part of the code generator state that says how to handle % failures; also called the failure continuation stack. :- type fail_info ---> fail_info( stack(resume_point_info), resume_point_known, curfr_vs_maxfr, condition_env, hijack_allowed ). % A resumption point has one or two labels associated with it. % Backtracking can arrive at either label. The code following % each label will assume that the variables needed at the resumption % point are in the locations given by the resume_map associated with % the given label and nowhere else. Any code that can cause % backtracking to a label must make sure that those variables are % in the positions expected by the label. % % The only time when a code_addr in a resume_point info is not a label % is when the code_addr is do_fail, which indicates that the resumption % point is not in (this invocation of) this procedure. :- type resume_point_info ---> orig_only(resume_map, code_addr) ; stack_only(resume_map, code_addr) ; orig_and_stack(resume_map, code_addr, resume_map, code_addr) ; stack_and_orig(resume_map, code_addr, resume_map, code_addr). % A resume map maps the variables that will be needed at a resumption % point to the locations in which they will be. :- type resume_map == map(prog_var, set(lval)). :- type redoip_update ---> has_been_done ; wont_be_done. :- type resume_point_known ---> resume_point_known(redoip_update) ; resume_point_unknown. :- type curfr_vs_maxfr ---> must_be_equal ; may_be_different. :- type condition_env ---> inside_non_condition ; not_inside_non_condition. :- type hijack_allowed ---> allowed ; not_allowed. %---------------------------------------------------------------------------% :- type disj_hijack_info ---> disj_no_hijack ; disj_temp_frame ; disj_quarter_hijack ; disj_half_hijack( lval % The stack slot in which we saved % the value of the hijacked redoip. ) ; disj_full_hijack( lval, % The stack slot in which we saved % the value of the hijacked redoip. lval % The stack slot in which we saved % the value of the hijacked redofr. ). code_info__prepare_for_disj_hijack(CodeModel, HijackInfo, Code) --> code_info__get_fail_info(FailInfo), { FailInfo = fail_info(_, ResumeKnown, CurfrMaxfr, CondEnv, Allow) }, ( { CodeModel \= model_non } -> { HijackInfo = disj_no_hijack }, { Code = node([ comment("disj no hijack") - "" ]) } ; { Allow = not_allowed ; CondEnv = inside_non_condition } -> { HijackInfo = disj_temp_frame }, code_info__create_temp_frame(do_fail, "prepare for disjunction", Code) ; { CurfrMaxfr = must_be_equal }, { ResumeKnown = resume_point_known(has_been_done) } -> { HijackInfo = disj_quarter_hijack }, { Code = node([ comment("disj quarter hijack") - "" ]) } ; { CurfrMaxfr = must_be_equal } -> % Here ResumeKnown must be resume_point_unknown % or resume_point_known(wont_be_done). code_info__acquire_temp_slot(lval(redoip(lval(curfr))), RedoipSlot), { HijackInfo = disj_half_hijack(RedoipSlot) }, { Code = node([ assign(RedoipSlot, lval(redoip(lval(curfr)))) - "prepare for half disj hijack" ]) } ; % Here CurfrMaxfr must be may_be_different. code_info__acquire_temp_slot(lval(redoip(lval(maxfr))), RedoipSlot), code_info__acquire_temp_slot(lval(redofr(lval(maxfr))), RedofrSlot), { HijackInfo = disj_full_hijack(RedoipSlot, RedofrSlot) }, { Code = node([ assign(RedoipSlot, lval(redoip(lval(maxfr)))) - "prepare for full disj hijack", assign(RedofrSlot, lval(redofr(lval(maxfr)))) - "prepare for full disj hijack", assign(redofr(lval(maxfr)), lval(curfr)) - "prepare for full disj hijack" ]) } ). code_info__undo_disj_hijack(HijackInfo, Code) --> code_info__get_fail_info(FailInfo0), { FailInfo0 = fail_info(ResumePoints, ResumeKnown, CurfrMaxfr, CondEnv, Allow) }, ( { HijackInfo = disj_no_hijack }, { Code = empty } ; { HijackInfo = disj_temp_frame }, { Code = node([ assign(maxfr, lval(prevfr(lval(maxfr)))) - "restore maxfr for temp frame disj" ]) } ; { HijackInfo = disj_quarter_hijack }, { require(unify(CurfrMaxfr, must_be_equal), "maxfr may differ from curfr in disj_quarter_hijack") }, { stack__top_det(ResumePoints, ResumePoint) }, { code_info__pick_stack_resume_point(ResumePoint, _, StackLabel) }, { LabelConst = const(code_addr_const(StackLabel)) }, { Code = node([ assign(redoip(lval(curfr)), LabelConst) - "restore redoip for quarter disj hijack" ]) } ; { HijackInfo = disj_half_hijack(RedoipSlot) }, { require(unify(ResumeKnown, resume_point_unknown), "resume point known in disj_half_hijack") }, { require(unify(CurfrMaxfr, must_be_equal), "maxfr may differ from curfr in disj_half_hijack") }, { Code = node([ assign(redoip(lval(curfr)), lval(RedoipSlot)) - "restore redoip for half disj hijack" ]) } ; { HijackInfo = disj_full_hijack(RedoipSlot, RedofrSlot) }, { require(unify(CurfrMaxfr, may_be_different), "maxfr same as curfr in disj_full_hijack") }, { Code = node([ assign(redoip(lval(maxfr)), lval(RedoipSlot)) - "restore redoip for full disj hijack", assign(redofr(lval(maxfr)), lval(RedofrSlot)) - "restore redofr for full disj hijack" ]) } ), ( % HijackInfo \= disj_no_hijack if and only if % the disjunction is model_non. { HijackInfo \= disj_no_hijack }, { CondEnv = inside_non_condition } -> { FailInfo = fail_info(ResumePoints, resume_point_unknown, CurfrMaxfr, CondEnv, Allow) }, code_info__set_fail_info(FailInfo) ; [] ). %---------------------------------------------------------------------------% :- type ite_hijack_info ---> ite_info( resume_point_known, condition_env, ite_hijack_type ). :- type ite_hijack_type ---> ite_no_hijack ; ite_temp_frame( lval % The stack slot in which we saved % the value of maxfr. ) ; ite_quarter_hijack ; ite_half_hijack( lval % The stack slot in which we saved % the value of the hijacked redoip. ) ; ite_full_hijack( lval, % The stack slot in which we saved % the value of the hijacked redoip. lval, % The stack slot in which we saved % the value of the hijacked redofr. lval % The stack slot in which we saved % the value of maxfr. ). code_info__prepare_for_ite_hijack(EffCodeModel, HijackInfo, Code) --> code_info__get_fail_info(FailInfo), { FailInfo = fail_info(_, ResumeKnown, CurfrMaxfr, CondEnv, Allow) }, ( { EffCodeModel \= model_non } -> { HijackType = ite_no_hijack }, { Code = node([ comment("ite no hijack") - "" ]) } ; { Allow = not_allowed ; CondEnv = inside_non_condition } -> code_info__acquire_temp_slot(lval(maxfr), MaxfrSlot), { HijackType = ite_temp_frame(MaxfrSlot) }, code_info__create_temp_frame(do_fail, "prepare for ite", TempFrameCode), { MaxfrCode = node([ assign(MaxfrSlot, lval(maxfr)) - "prepare for ite" ]) }, { Code = tree(TempFrameCode, MaxfrCode) } ; { CurfrMaxfr = must_be_equal }, { ResumeKnown = resume_point_known(_) } -> { HijackType = ite_quarter_hijack }, { Code = node([ comment("ite quarter hijack") - "" ]) } ; { CurfrMaxfr = must_be_equal } -> % Here ResumeKnown must be resume_point_unknown. code_info__acquire_temp_slot(lval(redoip(lval(curfr))), RedoipSlot), { HijackType = ite_half_hijack(RedoipSlot) }, { Code = node([ assign(RedoipSlot, lval(redoip(lval(curfr)))) - "prepare for half ite hijack" ]) } ; % Here CurfrMaxfr must be may_be_different. code_info__acquire_temp_slot(lval(redoip(lval(maxfr))), RedoipSlot), code_info__acquire_temp_slot(lval(redofr(lval(maxfr))), RedofrSlot), code_info__acquire_temp_slot(lval(maxfr), MaxfrSlot), { HijackType = ite_full_hijack(RedoipSlot, RedofrSlot, MaxfrSlot) }, { Code = node([ assign(MaxfrSlot, lval(maxfr)) - "prepare for full ite hijack", assign(RedoipSlot, lval(redoip(lval(maxfr)))) - "prepare for full ite hijack", assign(RedofrSlot, lval(redofr(lval(maxfr)))) - "prepare for full ite hijack", assign(redofr(lval(maxfr)), lval(curfr)) - "prepare for full ite hijack" ]) } ), { HijackInfo = ite_info(ResumeKnown, CondEnv, HijackType) }, ( { EffCodeModel = model_non } -> code_info__inside_non_condition ; [] ). code_info__ite_enter_then(HijackInfo, ThenCode, ElseCode) --> code_info__get_fail_info(FailInfo0), { FailInfo0 = fail_info(ResumePoints0, ResumeKnown0, CurfrMaxfr, _, Allow) }, { stack__pop_det(ResumePoints0, _, ResumePoints) }, { HijackInfo = ite_info(HijackResumeKnown, OldCondEnv, HijackType) }, { HijackType = ite_no_hijack, ThenCode = empty, ElseCode = ThenCode ; HijackType = ite_temp_frame(MaxfrSlot), ThenCode = node([ % We can't remove the frame, it may not be on top. assign(redoip(lval(MaxfrSlot)), const(code_addr_const(do_fail))) - "soft cut for temp frame ite" ]), ElseCode = node([ assign(maxfr, lval(prevfr(lval(MaxfrSlot)))) - "restore maxfr for temp frame ite" ]) ; HijackType = ite_quarter_hijack, stack__top_det(ResumePoints, ResumePoint), ( code_info__maybe_pick_stack_resume_point(ResumePoint, _, StackLabel) -> LabelConst = const(code_addr_const(StackLabel)), ThenCode = node([ assign(redoip(lval(curfr)), LabelConst) - "restore redoip for quarter ite hijack" ]) ; % This can happen only if ResumePoint is unreachable % from here. ThenCode = empty ), ElseCode = ThenCode ; HijackType = ite_half_hijack(RedoipSlot), ThenCode = node([ assign(redoip(lval(curfr)), lval(RedoipSlot)) - "restore redoip for half ite hijack" ]), ElseCode = ThenCode ; HijackType = ite_full_hijack(RedoipSlot, RedofrSlot, MaxfrSlot), ThenCode = node([ assign(redoip(lval(MaxfrSlot)), lval(RedoipSlot)) - "restore redoip for full ite hijack", assign(redofr(lval(MaxfrSlot)), lval(RedofrSlot)) - "restore redofr for full ite hijack" ]), ElseCode = node([ assign(redoip(lval(maxfr)), lval(RedoipSlot)) - "restore redoip for full ite hijack", assign(redofr(lval(maxfr)), lval(RedofrSlot)) - "restore redofr for full ite hijack" ]) }, { ResumeKnown0 = resume_point_unknown -> ResumeKnown = resume_point_unknown ; ResumeKnown = HijackResumeKnown }, { FailInfo = fail_info(ResumePoints, ResumeKnown, CurfrMaxfr, OldCondEnv, Allow) }, code_info__set_fail_info(FailInfo). %---------------------------------------------------------------------------% :- type simple_neg_info == fail_info. code_info__enter_simple_neg(ResumeVars, GoalInfo, FailInfo0) --> code_info__get_fail_info(FailInfo0), % The only reason why we push a resume point at all % is to protect the variables in ResumeVars from becoming % unknown; by including them in the domain of the resume point, % we guarantee that they will become zombies instead of % unknown if they die in the pre- or post-goal updates. % Therefore the only part of ResumePoint that matters % is the set of variables in the resume map; the other % parts of ResumePoint (the locations, the code address) % will not be referenced. { set__to_sorted_list(ResumeVars, ResumeVarList) }, { map__init(ResumeMap0) }, { code_info__make_fake_resume_map(ResumeVarList, ResumeMap0, ResumeMap) }, { ResumePoint = orig_only(ResumeMap, do_redo) }, code_info__effect_resume_point(ResumePoint, model_semi, Code), { require(unify(Code, empty), "nonempty code for simple neg") }, code_info__pre_goal_update(GoalInfo, yes). code_info__leave_simple_neg(GoalInfo, FailInfo) --> code_info__post_goal_update(GoalInfo), code_info__set_fail_info(FailInfo). :- pred code_info__make_fake_resume_map(list(prog_var)::in, map(prog_var, set(lval))::in, map(prog_var, set(lval))::out) is det. code_info__make_fake_resume_map([], ResumeMap, ResumeMap). code_info__make_fake_resume_map([Var | Vars], ResumeMap0, ResumeMap) :- % a visibly fake location set__singleton_set(Locns, reg(r, -1)), map__det_insert(ResumeMap0, Var, Locns, ResumeMap1), code_info__make_fake_resume_map(Vars, ResumeMap1, ResumeMap). %---------------------------------------------------------------------------% :- type det_commit_info ---> det_commit_info( maybe(lval), % Location of saved maxfr. maybe(pair(lval)) % Location of saved ticket % counter and trail pointer. ). code_info__prepare_for_det_commit(DetCommitInfo, Code) --> code_info__get_fail_info(FailInfo0), { FailInfo0 = fail_info(_, _, CurfrMaxfr, _, _) }, ( { CurfrMaxfr = may_be_different }, code_info__acquire_temp_slot(lval(maxfr), MaxfrSlot), { SaveMaxfrCode = node([ assign(MaxfrSlot, lval(maxfr)) - "save the value of maxfr" ]) }, { MaybeMaxfrSlot = yes(MaxfrSlot) } ; { CurfrMaxfr = must_be_equal }, { SaveMaxfrCode = empty }, { MaybeMaxfrSlot = no } ), code_info__maybe_save_trail_info(MaybeTrailSlots, SaveTrailCode), { DetCommitInfo = det_commit_info(MaybeMaxfrSlot, MaybeTrailSlots) }, { Code = tree(SaveMaxfrCode, SaveTrailCode) }. code_info__generate_det_commit(DetCommitInfo, Code) --> { DetCommitInfo = det_commit_info(MaybeMaxfrSlot, MaybeTrailSlots) }, ( { MaybeMaxfrSlot = yes(MaxfrSlot) }, { RestoreMaxfrCode = node([ assign(maxfr, lval(MaxfrSlot)) - "restore the value of maxfr - perform commit" ]) }, code_info__release_temp_slot(MaxfrSlot) ; { MaybeMaxfrSlot = no }, { RestoreMaxfrCode = node([ assign(maxfr, lval(curfr)) - "restore the value of maxfr - perform commit" ]) } ), code_info__maybe_restore_trail_info(MaybeTrailSlots, CommitTrailCode, _), { Code = tree(RestoreMaxfrCode, CommitTrailCode) }. %---------------------------------------------------------------------------% :- type semi_commit_info ---> semi_commit_info( fail_info, % Fail_info on entry. resume_point_info, commit_hijack_info, maybe(pair(lval)) % Location of saved ticket % counter and trail pointer. ). :- type commit_hijack_info ---> commit_temp_frame( lval, % The stack slot in which we saved % the old value of maxfr. bool % Do we bracket the goal with % MR_commit_mark and MR_commit_cut? ) ; commit_quarter_hijack ; commit_half_hijack( lval % The stack slot in which we saved % the value of the hijacked redoip. ) ; commit_full_hijack( lval, % The stack slot in which we saved % the value of the hijacked redoip. lval, % The stack slot in which we saved % the value of the hijacked redofr. lval % The stack slot in which we saved % the value of maxfr. ). code_info__prepare_for_semi_commit(SemiCommitInfo, Code) --> code_info__get_fail_info(FailInfo0), { FailInfo0 = fail_info(ResumePoints0, ResumeKnown, CurfrMaxfr, CondEnv, Allow) }, { stack__top_det(ResumePoints0, TopResumePoint) }, code_info__clone_resume_point(TopResumePoint, NewResumePoint), { stack__push(ResumePoints0, NewResumePoint, ResumePoints) }, { FailInfo = fail_info(ResumePoints, resume_point_known(has_been_done), CurfrMaxfr, CondEnv, Allow) }, code_info__set_fail_info(FailInfo), { code_info__pick_stack_resume_point(NewResumePoint, _, StackLabel) }, { StackLabelConst = const(code_addr_const(StackLabel)) }, ( { Allow = not_allowed ; CondEnv = inside_non_condition } -> code_info__acquire_temp_slot(lval(maxfr), MaxfrSlot), { MaxfrCode = node([ assign(MaxfrSlot, lval(maxfr)) - "prepare for temp frame commit" ]) }, code_info__create_temp_frame(StackLabel, "prepare for temp frame commit", TempFrameCode), code_info__get_globals(Globals), { globals__lookup_bool_option(Globals, use_minimal_model, UseMinimalModel) }, { HijackInfo = commit_temp_frame(MaxfrSlot, UseMinimalModel) }, { UseMinimalModel = yes, % If the code we are committing across starts but % does not complete the evaluation of a tabled subgoal, % the cut will remove the generator's choice point, % so that the evaluation of the subgoal will never % be completed. We handle such "dangling" generators % by removing them from the subgoal trie of the % tabled procedure. This requires knowing what % tabled subgoals are started inside commits, % which is why we wrap the goal being committed across % inside MR_commit_{mark,cut}. Components = [ pragma_c_raw_code( "\tMR_save_transient_registers();\n", live_lvals_info(set__init)), pragma_c_raw_code( "\tMR_commit_mark();\n", live_lvals_info(set__init)), pragma_c_raw_code( "\tMR_restore_transient_registers();\n", live_lvals_info(set__init)) ], MarkCode = node([ pragma_c([], Components, will_not_call_mercury, no, no, no, no, no) - "" ]) ; UseMinimalModel = no, MarkCode = empty }, { HijackCode = tree(MaxfrCode, tree(TempFrameCode, MarkCode)) } ; { ResumeKnown = resume_point_known(has_been_done) }, { CurfrMaxfr = must_be_equal } -> { HijackInfo = commit_quarter_hijack }, { HijackCode = node([ assign(redoip(lval(curfr)), StackLabelConst) - "hijack the redofr slot" ]) } ; { CurfrMaxfr = must_be_equal } -> % Here ResumeKnown must be resume_point_unknown or % resume_point_known(wont_be_done). code_info__acquire_temp_slot(lval(redoip(lval(curfr))), RedoipSlot), { HijackInfo = commit_half_hijack(RedoipSlot) }, { HijackCode = node([ assign(RedoipSlot, lval(redoip(lval(curfr)))) - "prepare for half commit hijack", assign(redoip(lval(curfr)), StackLabelConst) - "hijack the redofr slot" ]) } ; % Here CurfrMaxfr must be may_be_different. code_info__acquire_temp_slot(lval(redoip(lval(maxfr))), RedoipSlot), code_info__acquire_temp_slot(lval(redofr(lval(maxfr))), RedofrSlot), code_info__acquire_temp_slot(lval(maxfr), MaxfrSlot), { HijackInfo = commit_full_hijack(RedoipSlot, RedofrSlot, MaxfrSlot) }, { HijackCode = node([ assign(RedoipSlot, lval(redoip(lval(maxfr)))) - "prepare for full commit hijack", assign(RedofrSlot, lval(redofr(lval(maxfr)))) - "prepare for full commit hijack", assign(MaxfrSlot, lval(maxfr)) - "prepare for full commit hijack", assign(redofr(lval(maxfr)), lval(curfr)) - "hijack the redofr slot", assign(redoip(lval(maxfr)), StackLabelConst) - "hijack the redoip slot" ]) } ), code_info__maybe_save_trail_info(MaybeTrailSlots, SaveTrailCode), { SemiCommitInfo = semi_commit_info(FailInfo0, NewResumePoint, HijackInfo, MaybeTrailSlots) }, { Code = tree(HijackCode, SaveTrailCode) }. code_info__generate_semi_commit(SemiCommitInfo, Code) --> { SemiCommitInfo = semi_commit_info(FailInfo, ResumePoint, HijackInfo, MaybeTrailSlots) }, code_info__set_fail_info(FailInfo), % XXX should release the temp slots in each arm of the switch ( { HijackInfo = commit_temp_frame(MaxfrSlot, UseMinimalModel) }, { MaxfrCode = node([ assign(maxfr, lval(MaxfrSlot)) - "restore maxfr for temp frame hijack" ]) }, { UseMinimalModel = yes, % See the comment in prepare_for_semi_commit above. Components = [ pragma_c_raw_code("\tMR_commit_cut();\n", live_lvals_info(set__init)) ], CutCode = node([ pragma_c([], Components, will_not_call_mercury, no, no, no, no, no) - "commit for temp frame hijack" ]) ; UseMinimalModel = no, CutCode = empty }, { SuccessUndoCode = tree(MaxfrCode, CutCode) }, { FailureUndoCode = tree(MaxfrCode, CutCode) } ; { HijackInfo = commit_quarter_hijack }, { FailInfo = fail_info(ResumePoints, _, _, _, _) }, { stack__top_det(ResumePoints, TopResumePoint) }, { code_info__pick_stack_resume_point(TopResumePoint, _, StackLabel) }, { StackLabelConst = const(code_addr_const(StackLabel)) }, { SuccessUndoCode = node([ assign(maxfr, lval(curfr)) - "restore maxfr for quarter commit hijack", assign(redoip(lval(maxfr)), StackLabelConst) - "restore redoip for quarter commit hijack" ]) }, { FailureUndoCode = node([ assign(redoip(lval(maxfr)), StackLabelConst) - "restore redoip for quarter commit hijack" ]) } ; { HijackInfo = commit_half_hijack(RedoipSlot) }, { SuccessUndoCode = node([ assign(maxfr, lval(curfr)) - "restore maxfr for half commit hijack", assign(redoip(lval(maxfr)), lval(RedoipSlot)) - "restore redoip for half commit hijack" ]) }, { FailureUndoCode = node([ assign(redoip(lval(maxfr)), lval(RedoipSlot)) - "restore redoip for half commit hijack" ]) } ; { HijackInfo = commit_full_hijack(RedoipSlot, RedofrSlot, MaxfrSlot) }, { SuccessUndoCode = node([ assign(maxfr, lval(MaxfrSlot)) - "restore maxfr for full commit hijack", assign(redoip(lval(maxfr)), lval(RedoipSlot)) - "restore redoip for full commit hijack", assign(redofr(lval(maxfr)), lval(RedofrSlot)) - "restore redofr for full commit hijack" ]) }, { FailureUndoCode = node([ assign(redoip(lval(maxfr)), lval(RedoipSlot)) - "restore redoip for full commit hijack", assign(redofr(lval(maxfr)), lval(RedofrSlot)) - "restore redofr for full commit hijack" ]) } ), code_info__remember_position(AfterCommit), code_info__generate_resume_point(ResumePoint, ResumePointCode), code_info__generate_failure(FailCode), code_info__reset_to_position(AfterCommit), code_info__maybe_restore_trail_info(MaybeTrailSlots, CommitTrailCode, RestoreTrailCode), code_info__get_next_label(SuccLabel), { GotoSuccLabel = node([ goto(label(SuccLabel)) - "Jump to success continuation" ]) }, { SuccLabelCode = node([ label(SuccLabel) - "Success continuation" ]) }, { SuccessCode = tree(SuccessUndoCode, CommitTrailCode) }, { FailureCode = tree(ResumePointCode, tree(FailureUndoCode, tree(RestoreTrailCode, FailCode))) }, { Code = tree(SuccessCode, tree(GotoSuccLabel, tree(FailureCode, SuccLabelCode))) }. %---------------------------------------------------------------------------% :- pred code_info__inside_non_condition(code_info::in, code_info::out) is det. code_info__inside_non_condition --> code_info__get_fail_info(FailInfo0), { FailInfo0 = fail_info(ResumePoints, ResumeKnown, CurfrMaxfr, _, Allow) }, { FailInfo = fail_info(ResumePoints, ResumeKnown, CurfrMaxfr, inside_non_condition, Allow) }, code_info__set_fail_info(FailInfo). :- pred code_info__create_temp_frame(code_addr::in, string::in, code_tree::out, code_info::in, code_info::out) is det. code_info__create_temp_frame(Redoip, Comment, Code) --> code_info__get_proc_model(ProcModel), { ProcModel = model_non -> Kind = nondet_stack_proc ; Kind = det_stack_proc }, { Code = node([ mkframe(temp_frame(Kind), Redoip) - Comment ]) }, code_info__set_created_temp_frame(yes), code_info__get_fail_info(FailInfo0), { FailInfo0 = fail_info(ResumePoints, ResumeKnown, _, CondEnv, Allow) }, { FailInfo = fail_info(ResumePoints, ResumeKnown, may_be_different, CondEnv, Allow) }, code_info__set_fail_info(FailInfo). %---------------------------------------------------------------------------% code_info__effect_resume_point(ResumePoint, CodeModel, Code) --> code_info__get_fail_info(FailInfo0), { FailInfo0 = fail_info(ResumePoints0, _ResumeKnown, CurfrMaxfr, CondEnv, Allow) }, { stack__top(ResumePoints0, OldResumePoint) -> code_info__pick_first_resume_point(OldResumePoint, OldMap, _), code_info__pick_first_resume_point(ResumePoint, NewMap, _), map__keys(OldMap, OldKeys), map__keys(NewMap, NewKeys), set__list_to_set(OldKeys, OldKeySet), set__list_to_set(NewKeys, NewKeySet), require(set__subset(OldKeySet, NewKeySet), "non-nested resume point variable sets") ; true }, { stack__push(ResumePoints0, ResumePoint, ResumePoints) }, ( { CodeModel = model_non } -> { code_info__pick_stack_resume_point(ResumePoint, _, StackLabel) }, { LabelConst = const(code_addr_const(StackLabel)) }, { Code = node([ assign(redoip(lval(maxfr)), LabelConst) - "hijack redoip to effect resume point" ]) }, { RedoipUpdate = has_been_done } ; { Code = empty }, { RedoipUpdate = wont_be_done } ), { FailInfo = fail_info(ResumePoints, resume_point_known(RedoipUpdate), CurfrMaxfr, CondEnv, Allow) }, code_info__set_fail_info(FailInfo). code_info__pop_resume_point --> code_info__get_fail_info(FailInfo0), { FailInfo0 = fail_info(ResumePoints0, ResumeKnown, CurfrMaxfr, CondEnv, Allow) }, { stack__pop_det(ResumePoints0, _, ResumePoints) }, { FailInfo = fail_info(ResumePoints, ResumeKnown, CurfrMaxfr, CondEnv, Allow) }, code_info__set_fail_info(FailInfo). %---------------------------------------------------------------------------% code_info__top_resume_point(ResumePoint) --> code_info__get_fail_info(FailInfo), { FailInfo = fail_info(ResumePoints, _, _, _, _) }, { stack__top_det(ResumePoints, ResumePoint) }. code_info__set_resume_point_to_unknown --> code_info__get_fail_info(FailInfo0), { FailInfo0 = fail_info(ResumePoints, _, CurfrMaxfr, CondEnv, Allow) }, { FailInfo = fail_info(ResumePoints, resume_point_unknown, CurfrMaxfr, CondEnv, Allow) }, code_info__set_fail_info(FailInfo). code_info__set_resume_point_and_frame_to_unknown --> code_info__get_fail_info(FailInfo0), { FailInfo0 = fail_info(ResumePoints, _, _, CondEnv, Allow) }, { FailInfo = fail_info(ResumePoints, resume_point_unknown, may_be_different, CondEnv, Allow) }, code_info__set_fail_info(FailInfo). %---------------------------------------------------------------------------% code_info__generate_failure(Code) --> code_info__get_fail_info(FailInfo), { FailInfo = fail_info(ResumePoints, ResumeKnown, _, _, _) }, ( { ResumeKnown = resume_point_known(_) }, { stack__top_det(ResumePoints, TopResumePoint) }, ( code_info__pick_matching_resume_addr(TopResumePoint, FailureAddress0) -> { FailureAddress = FailureAddress0 }, { PlaceCode = empty } ; { code_info__pick_first_resume_point(TopResumePoint, Map, FailureAddress) }, { map__to_assoc_list(Map, AssocList) }, code_info__remember_position(CurPos), code_info__pick_and_place_vars(AssocList, _, PlaceCode), code_info__reset_to_position(CurPos) ), { BranchCode = node([goto(FailureAddress) - "fail"]) }, { Code = tree(PlaceCode, BranchCode) } ; { ResumeKnown = resume_point_unknown }, { Code = node([goto(do_redo) - "fail"]) } ). code_info__fail_if_rval_is_false(Rval0, Code) --> code_info__get_fail_info(FailInfo), { FailInfo = fail_info(ResumePoints, ResumeKnown, _, _, _) }, ( { ResumeKnown = resume_point_known(_) }, { stack__top_det(ResumePoints, TopResumePoint) }, ( code_info__pick_matching_resume_addr(TopResumePoint, FailureAddress0) -> % We branch away if the test *fails* { code_util__neg_rval(Rval0, Rval) }, { Code = node([ if_val(Rval, FailureAddress0) - "Test for failure" ]) } ; { code_info__pick_first_resume_point(TopResumePoint, Map, FailureAddress) }, { map__to_assoc_list(Map, AssocList) }, code_info__get_next_label(SuccessLabel), code_info__remember_position(CurPos), code_info__pick_and_place_vars(AssocList, _, PlaceCode), code_info__reset_to_position(CurPos), { SuccessAddress = label(SuccessLabel) }, % We branch away if the test *fails*, % therefore if the test succeeds, we branch % around the code that moves variables to % their failure locations and branches away % to the failure continuation { TestCode = node([ if_val(Rval0, SuccessAddress) - "Test for failure" ]) }, { TailCode = node([ goto(FailureAddress) - "Goto failure", label(SuccessLabel) - "Success continuation" ]) }, { Code = tree(TestCode, tree(PlaceCode, TailCode)) } ) ; { ResumeKnown = resume_point_unknown }, % We branch away if the test *fails* { code_util__neg_rval(Rval0, Rval) }, { Code = node([ if_val(Rval, do_redo) - "Test for failure" ]) } ). %---------------------------------------------------------------------------% code_info__failure_is_direct_branch(CodeAddr) --> code_info__get_fail_info(FailInfo), { FailInfo = fail_info(ResumePoints, resume_point_known(_), _, _, _) }, { stack__top(ResumePoints, TopResumePoint) }, code_info__pick_matching_resume_addr(TopResumePoint, CodeAddr). code_info__may_use_nondet_tailcall(TailCallStatus) --> code_info__get_fail_info(FailInfo), { FailInfo = fail_info(ResumePoints0, ResumeKnown, _, _, _) }, { stack__pop(ResumePoints0, ResumePoint1, ResumePoints1), stack__is_empty(ResumePoints1), ResumePoint1 = stack_only(_, do_fail) -> ( ResumeKnown = resume_point_known(_), TailCallStatus = unchecked_tail_call ; ResumeKnown = resume_point_unknown, TailCallStatus = checked_tail_call ) ; TailCallStatus = no_tail_call }. %---------------------------------------------------------------------------% % See whether the current locations of variables match the locations % associated with any of the options in the given failure map. % If yes, return the code_addr of that option. :- pred code_info__pick_matching_resume_addr(resume_point_info::in, code_addr::out, code_info::in, code_info::out) is semidet. code_info__pick_matching_resume_addr(ResumeMaps, Addr) --> code_info__variable_locations(CurLocs), { ResumeMaps = orig_only(Map1, Addr1), ( code_info__match_resume_loc(Map1, CurLocs) -> Addr = Addr1 ; fail ) ; ResumeMaps = stack_only(Map1, Addr1), ( code_info__match_resume_loc(Map1, CurLocs) -> Addr = Addr1 ; fail ) ; ResumeMaps = orig_and_stack(Map1, Addr1, Map2, Addr2), ( code_info__match_resume_loc(Map1, CurLocs) -> Addr = Addr1 ; code_info__match_resume_loc(Map2, CurLocs) -> Addr = Addr2 ; fail ) ; ResumeMaps = stack_and_orig(Map1, Addr1, Map2, Addr2), ( code_info__match_resume_loc(Map1, CurLocs) -> Addr = Addr1 ; code_info__match_resume_loc(Map2, CurLocs) -> Addr = Addr2 ; fail ) }. :- pred code_info__match_resume_loc(resume_map::in, resume_map::in) is semidet. code_info__match_resume_loc(Map, Locations0) :- map__keys(Map, KeyList), set__list_to_set(KeyList, Keys), map__select(Locations0, Keys, Locations), map__to_assoc_list(Locations, List), \+ ( list__member(Var - Actual, List), \+ ( map__search(Map, Var, Lvals), set__subset(Lvals, Actual) ) ). :- pred code_info__pick_first_resume_point(resume_point_info::in, resume_map::out, code_addr::out) is det. code_info__pick_first_resume_point(orig_only(Map, Addr), Map, Addr). code_info__pick_first_resume_point(stack_only(Map, Addr), Map, Addr). code_info__pick_first_resume_point(orig_and_stack(Map, Addr, _, _), Map, Addr). code_info__pick_first_resume_point(stack_and_orig(Map, Addr, _, _), Map, Addr). :- pred code_info__pick_stack_resume_point(resume_point_info::in, resume_map::out, code_addr::out) is det. code_info__pick_stack_resume_point(ResumePoint, Map, Addr) :- ( code_info__maybe_pick_stack_resume_point(ResumePoint, Map1, Addr1) -> Map = Map1, Addr = Addr1 ; error("no stack resume point") ). :- pred code_info__maybe_pick_stack_resume_point(resume_point_info::in, resume_map::out, code_addr::out) is semidet. code_info__maybe_pick_stack_resume_point(stack_only(Map, Addr), Map, Addr). code_info__maybe_pick_stack_resume_point(orig_and_stack(_, _, Map, Addr), Map, Addr). code_info__maybe_pick_stack_resume_point(stack_and_orig(Map, Addr, _, _), Map, Addr). %---------------------------------------------------------------------------% code_info__produce_vars(Vars, Map, Code) --> { set__to_sorted_list(Vars, VarList) }, code_info__produce_vars_2(VarList, Map, Code). :- pred code_info__produce_vars_2(list(prog_var)::in, map(prog_var, set(lval))::out, code_tree::out, code_info::in, code_info::out) is det. code_info__produce_vars_2([], Map, empty) --> { map__init(Map) }. code_info__produce_vars_2([V | Vs], Map, Code) --> code_info__produce_vars_2(Vs, Map0, Code0), code_info__produce_variable_in_reg_or_stack(V, Code1, Lval), { set__singleton_set(Lvals, Lval) }, { map__set(Map0, V, Lvals, Map) }, { Code = tree(Code0, Code1) }. code_info__flush_resume_vars_to_stack(Code) --> code_info__compute_resume_var_stack_locs(VarLocs), code_info__place_vars(VarLocs, Code). :- pred compute_resume_var_stack_locs(assoc_list(prog_var, lval)::out, code_info::in, code_info::out) is det. code_info__compute_resume_var_stack_locs(VarLocs) --> code_info__get_fail_info(FailInfo), { FailInfo = fail_info(ResumePointStack, _, _, _, _) }, { stack__top_det(ResumePointStack, ResumePoint) }, { code_info__pick_stack_resume_point(ResumePoint, StackMap, _) }, { map__to_assoc_list(StackMap, VarLocSets) }, { code_info__pick_var_places(VarLocSets, VarLocs) }. %---------------------------------------------------------------------------% :- pred code_info__init_fail_info(code_model::in, maybe(set(prog_var))::in, resume_point_info::out, code_info::in, code_info::out) is det. code_info__init_fail_info(CodeModel, MaybeFailVars, ResumePoint) --> ( { CodeModel = model_det }, code_info__get_next_label(ResumeLabel), { ResumeAddress = label(ResumeLabel) }, { ResumeKnown = resume_point_unknown }, { CurfrMaxfr = may_be_different } ; { CodeModel = model_semi }, % The resume point for this label % will be part of the procedure epilog. code_info__get_next_label(ResumeLabel), { ResumeAddress = label(ResumeLabel) }, { ResumeKnown = resume_point_known(wont_be_done) }, { CurfrMaxfr = may_be_different } ; { CodeModel = model_non }, ( { MaybeFailVars = yes(_) } -> code_info__get_next_label(ResumeLabel), { ResumeAddress = label(ResumeLabel) } ; { ResumeAddress = do_fail } ), { ResumeKnown = resume_point_known(has_been_done) }, { CurfrMaxfr = must_be_equal } ), ( { MaybeFailVars = yes(FailVars) } -> code_info__get_stack_slots(StackSlots), { map__select(StackSlots, FailVars, StackMap0) }, { map__to_assoc_list(StackMap0, StackList0) }, { code_info__make_singleton_sets(StackList0, StackList) }, { map__from_assoc_list(StackList, StackMap) } ; { map__init(StackMap) } ), { ResumePoint = stack_only(StackMap, ResumeAddress) }, { stack__init(ResumeStack0) }, { stack__push(ResumeStack0, ResumePoint, ResumeStack) }, code_info__get_fail_info(FailInfo0), { FailInfo0 = fail_info(_, _, _, _, Allow) }, { FailInfo = fail_info(ResumeStack, ResumeKnown, CurfrMaxfr, not_inside_non_condition, Allow) }, code_info__set_fail_info(FailInfo). %---------------------------------------------------------------------------% code_info__make_resume_point(ResumeVars, ResumeLocs, FullMap, ResumePoint) --> code_info__get_stack_slots(StackSlots), { map__select(FullMap, ResumeVars, OrigMap) }, ( { ResumeLocs = orig_only }, code_info__get_next_label(OrigLabel), { OrigAddr = label(OrigLabel) }, { ResumePoint = orig_only(OrigMap, OrigAddr) } ; { ResumeLocs = stack_only }, { map__select(StackSlots, ResumeVars, StackMap0) }, { map__to_assoc_list(StackMap0, StackList0) }, { code_info__make_singleton_sets(StackList0, StackList) }, { map__from_assoc_list(StackList, StackMap) }, code_info__get_next_label(StackLabel), { StackAddr = label(StackLabel) }, { ResumePoint = stack_only(StackMap, StackAddr) } ; { ResumeLocs = orig_and_stack }, { map__select(StackSlots, ResumeVars, StackMap0) }, { map__to_assoc_list(StackMap0, StackList0) }, { code_info__make_singleton_sets(StackList0, StackList) }, { map__from_assoc_list(StackList, StackMap) }, code_info__get_next_label(OrigLabel), { OrigAddr = label(OrigLabel) }, code_info__get_next_label(StackLabel), { StackAddr = label(StackLabel) }, { ResumePoint = orig_and_stack(OrigMap, OrigAddr, StackMap, StackAddr) } ; { ResumeLocs = stack_and_orig }, { map__select(StackSlots, ResumeVars, StackMap0) }, { map__to_assoc_list(StackMap0, StackList0) }, { code_info__make_singleton_sets(StackList0, StackList) }, { map__from_assoc_list(StackList, StackMap) }, code_info__get_next_label(StackLabel), { StackAddr = label(StackLabel) }, code_info__get_next_label(OrigLabel), { OrigAddr = label(OrigLabel) }, { ResumePoint = stack_and_orig(StackMap, StackAddr, OrigMap, OrigAddr) } ). :- pred code_info__make_singleton_sets(assoc_list(prog_var, lval)::in, assoc_list(prog_var, set(lval))::out) is det. code_info__make_singleton_sets([], []). code_info__make_singleton_sets([V - L | Rest0], [V - Ls | Rest]) :- set__singleton_set(Ls, L), code_info__make_singleton_sets(Rest0, Rest). %---------------------------------------------------------------------------% % The code we generate for a resumption point looks like this: % % label(StackLabel) % % % label(OrigLabel) % % % Failures at different points may cause control to arrive at % the resumption point via either label, which is why the last % line is necessary. % % The idea is that failures from other procedures will go to % StackLabel, and that failures from this procedure while % everything is in its original place will go to OrigLabel. % Failures from this procedure where not everything is in its % original place can go to either, after moving the resume variables % to the places where the label expects them. % % The above layout (stack, then orig) is the most common. However, % liveness.m may decide that one or other of the two labels will % never be referred to (e.g. because there are no calls inside % the range of effect of the resumption point or because a call % follows immediately after the establishment of the resumption % point), or that it would be more efficient to put the two labels % in the other order (e.g. because the code after the resumption point % needs most of the variables in their stack slots). code_info__generate_resume_point(ResumePoint, Code) --> ( { ResumePoint = orig_only(Map1, Addr1) }, { extract_label_from_code_addr(Addr1, Label1) }, { Code = node([ label(Label1) - "orig only failure continuation" ]) }, code_info__set_var_locations(Map1) ; { ResumePoint = stack_only(Map1, Addr1) }, { extract_label_from_code_addr(Addr1, Label1) }, { Code = node([ label(Label1) - "stack only failure continuation" ]) }, code_info__set_var_locations(Map1), code_info__generate_resume_layout(Label1, Map1) ; { ResumePoint = stack_and_orig(Map1, Addr1, Map2, Addr2) }, { extract_label_from_code_addr(Addr1, Label1) }, { extract_label_from_code_addr(Addr2, Label2) }, { Label1Code = node([ label(Label1) - "stack failure continuation before orig" ]) }, code_info__set_var_locations(Map1), code_info__generate_resume_layout(Label1, Map1), { map__to_assoc_list(Map2, AssocList2) }, code_info__place_resume_vars(AssocList2, PlaceCode), { Label2Code = node([ label(Label2) - "orig failure continuation after stack" ]) }, code_info__set_var_locations(Map2), { Code = tree(Label1Code, tree(PlaceCode, Label2Code)) } ; { ResumePoint = orig_and_stack(Map1, Addr1, Map2, Addr2) }, { extract_label_from_code_addr(Addr1, Label1) }, { extract_label_from_code_addr(Addr2, Label2) }, { Label1Code = node([ label(Label1) - "orig failure continuation before stack" ]) }, code_info__set_var_locations(Map1), { map__to_assoc_list(Map2, AssocList2) }, code_info__place_resume_vars(AssocList2, PlaceCode), { Label2Code = node([ label(Label2) - "stack failure continuation after orig" ]) }, code_info__set_var_locations(Map2), code_info__generate_resume_layout(Label2, Map2), { Code = tree(Label1Code, tree(PlaceCode, Label2Code)) } ). :- pred extract_label_from_code_addr(code_addr::in, label::out) is det. extract_label_from_code_addr(CodeAddr, Label) :- ( CodeAddr = label(Label0) -> Label = Label0 ; error("extract_label_from_code_addr: non-label!") ). :- pred code_info__place_resume_vars(assoc_list(prog_var, set(lval))::in, code_tree::out, code_info::in, code_info::out) is det. code_info__place_resume_vars([], empty) --> []. code_info__place_resume_vars([Var - TargetSet | Rest], Code) --> { set__to_sorted_list(TargetSet, Targets) }, code_info__place_resume_var(Var, Targets, FirstCode), { Code = tree(FirstCode, RestCode) }, code_info__place_resume_vars(Rest, RestCode). :- pred code_info__place_resume_var(prog_var::in, list(lval)::in, code_tree::out, code_info::in, code_info::out) is det. code_info__place_resume_var(_Var, [], empty) --> []. code_info__place_resume_var(Var, [Target | Targets], Code) --> code_info__place_var(Var, Target, FirstCode), code_info__place_resume_var(Var, Targets, RestCode), { Code = tree(FirstCode, RestCode) }. % Reset the code generator's database of what is where. % Remember that the variables in the map are available in their % associated rvals; forget about all other variables. :- pred code_info__set_var_locations(resume_map::in, code_info::in, code_info::out) is det. code_info__set_var_locations(Map) --> { map__to_assoc_list(Map, LvalList0) }, { code_info__flatten_varlval_list(LvalList0, LvalList) }, code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(Exprn0), RvalList = assoc_list__map_values(exprn_aux__var_lval_to_rval, LvalList), code_exprn__reinit_state(RvalList, Exprn0, Exprn), VarInfo = exprn_info(Exprn) ; VarInfo0 = var_locn_info(VarLocnInfo0), var_locn__reinit_state(LvalList, VarLocnInfo0, VarLocnInfo), VarInfo = var_locn_info(VarLocnInfo) }, code_info__set_var_locns_info(VarInfo). :- pred code_info__flatten_varlval_list(assoc_list(prog_var, set(lval))::in, assoc_list(prog_var, lval)::out) is det. code_info__flatten_varlval_list([], []). code_info__flatten_varlval_list([V - Rvals | Rest0], All) :- code_info__flatten_varlval_list(Rest0, Rest), set__to_sorted_list(Rvals, RvalList), code_info__flatten_varlval_list_2(RvalList, V, Rest1), list__append(Rest1, Rest, All). :- pred code_info__flatten_varlval_list_2(list(lval)::in, prog_var::in, assoc_list(prog_var, lval)::out) is det. code_info__flatten_varlval_list_2([], _V, []). code_info__flatten_varlval_list_2([R | Rs], V, [V - R | Rest]) :- code_info__flatten_varlval_list_2(Rs, V, Rest). code_info__resume_point_vars(ResumePoint, Vars) :- code_info__pick_first_resume_point(ResumePoint, ResumeMap, _), map__keys(ResumeMap, Vars). code_info__resume_point_stack_addr(ResumePoint, StackAddr) :- code_info__pick_stack_resume_point(ResumePoint, _, StackAddr). %---------------------------------------------------------------------------% :- pred code_info__maybe_save_trail_info(maybe(pair(lval))::out, code_tree::out, code_info::in, code_info::out) is det. code_info__maybe_save_trail_info(MaybeTrailSlots, SaveTrailCode) --> code_info__get_globals(Globals), { globals__lookup_bool_option(Globals, use_trail, UseTrail) }, ( { UseTrail = yes } -> code_info__acquire_temp_slot(ticket_counter, CounterSlot), code_info__acquire_temp_slot(ticket, TrailPtrSlot), { MaybeTrailSlots = yes(CounterSlot - TrailPtrSlot) }, { SaveTrailCode = node([ mark_ticket_stack(CounterSlot) - "save the ticket counter", store_ticket(TrailPtrSlot) - "save the trail pointer" ]) } ; { MaybeTrailSlots = no }, { SaveTrailCode = empty } ). :- pred code_info__maybe_restore_trail_info(maybe(pair(lval))::in, code_tree::out, code_tree::out, code_info::in, code_info::out) is det. code_info__maybe_restore_trail_info(MaybeTrailSlots, CommitCode, RestoreCode) --> ( { MaybeTrailSlots = no }, { CommitCode = empty }, { RestoreCode = empty } ; { MaybeTrailSlots = yes(CounterSlot - TrailPtrSlot) }, { CommitCode = node([ reset_ticket(lval(TrailPtrSlot), commit) - "discard trail entries and restore trail ptr", prune_tickets_to(lval(CounterSlot)) - "restore ticket counter (but not high water mark)" ]) }, { RestoreCode = node([ reset_ticket(lval(TrailPtrSlot), undo) - "apply trail entries and restore trail ptr", discard_ticket - "restore ticket counter and high water mark" ]) }, code_info__release_temp_slot(CounterSlot), code_info__release_temp_slot(TrailPtrSlot) ). %---------------------------------------------------------------------------% :- pred code_info__clone_resume_point(resume_point_info::in, resume_point_info::out, code_info::in, code_info::out) is det. code_info__clone_resume_point(ResumePoint0, ResumePoint) --> ( { ResumePoint0 = orig_only(_, _) }, { error("cloning orig_only resume point") } ; { ResumePoint0 = stack_only(Map1, _) }, code_info__get_next_label(Label1), { Addr1 = label(Label1) }, { ResumePoint = stack_only(Map1, Addr1) } ; { ResumePoint0 = stack_and_orig(Map1, _, Map2, _) }, code_info__get_next_label(Label1), { Addr1 = label(Label1) }, code_info__get_next_label(Label2), { Addr2 = label(Label2) }, { ResumePoint = stack_and_orig(Map1, Addr1, Map2, Addr2) } ; { ResumePoint0 = orig_and_stack(Map1, _, Map2, _) }, code_info__get_next_label(Label2), { Addr2 = label(Label2) }, code_info__get_next_label(Label1), { Addr1 = label(Label1) }, { ResumePoint = stack_and_orig(Map2, Addr2, Map1, Addr1) } ). %---------------------------------------------------------------------------% %---------------------------------------------------------------------------% % Submodule to deal with liveness issues. % The principles underlying this submodule of code_info.m are % documented in the file compiler/notes/allocation.html. :- interface. :- pred code_info__get_known_variables(list(prog_var), code_info, code_info). :- mode code_info__get_known_variables(out, in, out) is det. :- pred code_info__variable_is_forward_live(prog_var, code_info, code_info). :- mode code_info__variable_is_forward_live(in, in, out) is semidet. :- pred code_info__make_vars_forward_dead(set(prog_var), code_info, code_info). :- mode code_info__make_vars_forward_dead(in, in, out) is det. :- pred code_info__pickup_zombies(set(prog_var), code_info, code_info). :- mode code_info__pickup_zombies(out, in, out) is det. %---------------------------------------------------------------------------% :- implementation. :- pred code_info__add_forward_live_vars(set(prog_var), code_info, code_info). :- mode code_info__add_forward_live_vars(in, in, out) is det. :- pred code_info__rem_forward_live_vars(set(prog_var), code_info, code_info). :- mode code_info__rem_forward_live_vars(in, in, out) is det. % Make these variables appear magically live. % We don't care where they are put. :- pred code_info__make_vars_forward_live(set(prog_var), code_info, code_info). :- mode code_info__make_vars_forward_live(in, in, out) is det. code_info__get_known_variables(VarList) --> code_info__get_forward_live_vars(ForwardLiveVars), code_info__current_resume_point_vars(ResumeVars), { set__union(ForwardLiveVars, ResumeVars, Vars) }, { set__to_sorted_list(Vars, VarList) }. code_info__variable_is_forward_live(Var) --> code_info__get_forward_live_vars(Liveness), { set__member(Var, Liveness) }. code_info__add_forward_live_vars(Births) --> code_info__get_forward_live_vars(Liveness0), { set__union(Liveness0, Births, Liveness) }, code_info__set_forward_live_vars(Liveness). code_info__rem_forward_live_vars(Deaths) --> code_info__get_forward_live_vars(Liveness0), { set__difference(Liveness0, Deaths, Liveness) }, code_info__set_forward_live_vars(Liveness). code_info__make_vars_forward_live(Vars) --> code_info__get_stack_slots(StackSlots), code_info__get_var_locns_info(VarInfo0), { set__to_sorted_list(Vars, VarList) }, { code_info__make_vars_forward_live_2(VarList, StackSlots, 1, VarInfo0, VarInfo) }, code_info__set_var_locns_info(VarInfo). :- pred code_info__make_vars_forward_live_2(list(prog_var), stack_slots, int, var_locns_info, var_locns_info). :- mode code_info__make_vars_forward_live_2(in, in, in, in, out) is det. code_info__make_vars_forward_live_2([], _, _, VarInfo, VarInfo). code_info__make_vars_forward_live_2([Var | Vars], StackSlots, N0, VarInfo0, VarInfo) :- ( map__search(StackSlots, Var, Lval0) -> Lval = Lval0, N1 = N0 ; code_info__find_unused_reg(N0, VarInfo0, N1), Lval = reg(r, N1) ), ( VarInfo0 = exprn_info(Exprn0), code_exprn__maybe_set_var_location(Var, Lval, Exprn0, Exprn1), VarInfo1 = exprn_info(Exprn1) ; VarInfo0 = var_locn_info(VarLocn0), var_locn__set_magic_var_location(Var, Lval, VarLocn0, VarLocn1), VarInfo1 = var_locn_info(VarLocn1) ), code_info__make_vars_forward_live_2(Vars, StackSlots, N1, VarInfo1, VarInfo). :- pred code_info__find_unused_reg(int, var_locns_info, int). :- mode code_info__find_unused_reg(in, in, out) is det. code_info__find_unused_reg(N0, VarInfo0, N) :- ( VarInfo0 = exprn_info(Exprn0), code_info__find_unused_reg_lazy(N0, Exprn0, N) ; VarInfo0 = var_locn_info(VarLocn0), code_info__find_unused_reg_eager(N0, VarLocn0, N) ). :- pred code_info__find_unused_reg_eager(int, var_locn_info, int). :- mode code_info__find_unused_reg_eager(in, in, out) is det. code_info__find_unused_reg_eager(N0, Exprn0, N) :- ( var_locn__lval_in_use(reg(r, N0), Exprn0, _) -> N1 is N0 + 1, code_info__find_unused_reg_eager(N1, Exprn0, N) ; N = N0 ). :- pred code_info__find_unused_reg_lazy(int, exprn_info, int). :- mode code_info__find_unused_reg_lazy(in, in, out) is det. code_info__find_unused_reg_lazy(N0, Exprn0, N) :- ( code_exprn__lval_in_use(reg(r, N0), Exprn0, _) -> N1 is N0 + 1, code_info__find_unused_reg_lazy(N1, Exprn0, N) ; N = N0 ). code_info__make_vars_forward_dead(Vars) --> code_info__maybe_make_vars_forward_dead(Vars, yes). :- pred code_info__maybe_make_vars_forward_dead(set(prog_var), bool, code_info, code_info). :- mode code_info__maybe_make_vars_forward_dead(in, in, in, out) is det. code_info__maybe_make_vars_forward_dead(Vars0, FirstTime) --> code_info__current_resume_point_vars(ResumeVars), { set__intersect(Vars0, ResumeVars, FlushVars) }, code_info__get_zombies(Zombies0), { set__union(Zombies0, FlushVars, Zombies) }, code_info__set_zombies(Zombies), { set__difference(Vars0, Zombies, Vars) }, { set__to_sorted_list(Vars, VarList) }, code_info__maybe_make_vars_forward_dead_2(VarList, FirstTime). :- pred code_info__maybe_make_vars_forward_dead_2(list(prog_var), bool, code_info, code_info). :- mode code_info__maybe_make_vars_forward_dead_2(in, in, in, out) is det. code_info__maybe_make_vars_forward_dead_2([], _) --> []. code_info__maybe_make_vars_forward_dead_2([V | Vs], FirstTime) --> code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(Exprn0), code_exprn__var_becomes_dead(V, Exprn0, Exprn), VarInfo = exprn_info(Exprn) ; VarInfo0 = var_locn_info(VarLocn0), var_locn__var_becomes_dead(V, FirstTime, VarLocn0, VarLocn), VarInfo = var_locn_info(VarLocn) }, code_info__set_var_locns_info(VarInfo), code_info__maybe_make_vars_forward_dead_2(Vs, FirstTime). code_info__pickup_zombies(Zombies) --> code_info__get_zombies(Zombies), { set__init(Empty) }, code_info__set_zombies(Empty). %---------------------------------------------------------------------------% %---------------------------------------------------------------------------% % Submodule for handling the saving and restoration % of trail tickets, heap pointers, stack pointers etc. :- interface. :- pred code_info__save_hp(code_tree, lval, code_info, code_info). :- mode code_info__save_hp(out, out, in, out) is det. :- pred code_info__restore_hp(lval, code_tree, code_info, code_info). :- mode code_info__restore_hp(in, out, in, out) is det. :- pred code_info__release_hp(lval, code_info, code_info). :- mode code_info__release_hp(in, in, out) is det. :- pred code_info__restore_and_release_hp(lval, code_tree, code_info, code_info). :- mode code_info__restore_and_release_hp(in, out, in, out) is det. :- pred code_info__maybe_save_hp(bool, code_tree, maybe(lval), code_info, code_info). :- mode code_info__maybe_save_hp(in, out, out, in, out) is det. :- pred code_info__maybe_restore_hp(maybe(lval), code_tree, code_info, code_info). :- mode code_info__maybe_restore_hp(in, out, in, out) is det. :- pred code_info__maybe_release_hp(maybe(lval), code_info, code_info). :- mode code_info__maybe_release_hp(in, in, out) is det. :- pred code_info__maybe_restore_and_release_hp(maybe(lval), code_tree, code_info, code_info). :- mode code_info__maybe_restore_and_release_hp(in, out, in, out) is det. :- pred code_info__save_ticket(code_tree, lval, code_info, code_info). :- mode code_info__save_ticket(out, out, in, out) is det. :- pred code_info__reset_ticket(lval, reset_trail_reason, code_tree, code_info, code_info). :- mode code_info__reset_ticket(in, in, out, in, out) is det. :- pred code_info__release_ticket(lval, code_info, code_info). :- mode code_info__release_ticket(in, in, out) is det. :- pred code_info__reset_and_prune_ticket(lval, reset_trail_reason, code_tree, code_info, code_info). :- mode code_info__reset_and_prune_ticket(in, in, out, in, out) is det. :- pred code_info__reset_prune_and_release_ticket(lval, reset_trail_reason, code_tree, code_info, code_info). :- mode code_info__reset_prune_and_release_ticket(in, in, out, in, out) is det. :- pred code_info__reset_and_discard_ticket(lval, reset_trail_reason, code_tree, code_info, code_info). :- mode code_info__reset_and_discard_ticket(in, in, out, in, out) is det. :- pred code_info__reset_discard_and_release_ticket(lval, reset_trail_reason, code_tree, code_info, code_info). :- mode code_info__reset_discard_and_release_ticket(in, in, out, in, out) is det. :- pred code_info__maybe_save_ticket(bool, code_tree, maybe(lval), code_info, code_info). :- mode code_info__maybe_save_ticket(in, out, out, in, out) is det. :- pred code_info__maybe_reset_ticket(maybe(lval), reset_trail_reason, code_tree, code_info, code_info). :- mode code_info__maybe_reset_ticket(in, in, out, in, out) is det. :- pred code_info__maybe_release_ticket(maybe(lval), code_info, code_info). :- mode code_info__maybe_release_ticket(in, in, out) is det. :- pred code_info__maybe_reset_and_prune_ticket(maybe(lval), reset_trail_reason, code_tree, code_info, code_info). :- mode code_info__maybe_reset_and_prune_ticket(in, in, out, in, out) is det. :- pred code_info__maybe_reset_prune_and_release_ticket(maybe(lval), reset_trail_reason, code_tree, code_info, code_info). :- mode code_info__maybe_reset_prune_and_release_ticket(in, in, out, in, out) is det. :- pred code_info__maybe_reset_and_discard_ticket(maybe(lval), reset_trail_reason, code_tree, code_info, code_info). :- mode code_info__maybe_reset_and_discard_ticket(in, in, out, in, out) is det. :- pred code_info__maybe_reset_discard_and_release_ticket(maybe(lval), reset_trail_reason, code_tree, code_info, code_info). :- mode code_info__maybe_reset_discard_and_release_ticket(in, in, out, in, out) is det. %---------------------------------------------------------------------------% :- implementation. code_info__save_hp(Code, HpSlot) --> code_info__acquire_temp_slot(lval(hp), HpSlot), { Code = node([ mark_hp(HpSlot) - "Save heap pointer" ]) }. code_info__restore_hp(HpSlot, Code) --> { Code = node([ restore_hp(lval(HpSlot)) - "Restore heap pointer" ]) }. code_info__release_hp(HpSlot) --> code_info__release_temp_slot(HpSlot). code_info__restore_and_release_hp(HpSlot, Code) --> { Code = node([ restore_hp(lval(HpSlot)) - "Release heap pointer" ]) }, code_info__release_hp(HpSlot). %---------------------------------------------------------------------------% code_info__maybe_save_hp(Maybe, Code, MaybeHpSlot) --> ( { Maybe = yes } -> code_info__save_hp(Code, HpSlot), { MaybeHpSlot = yes(HpSlot) } ; { Code = empty }, { MaybeHpSlot = no } ). code_info__maybe_restore_hp(MaybeHpSlot, Code) --> ( { MaybeHpSlot = yes(HpSlot) } -> code_info__restore_hp(HpSlot, Code) ; { Code = empty } ). code_info__maybe_release_hp(MaybeHpSlot) --> ( { MaybeHpSlot = yes(HpSlot) } -> code_info__release_hp(HpSlot) ; [] ). code_info__maybe_restore_and_release_hp(MaybeHpSlot, Code) --> ( { MaybeHpSlot = yes(HpSlot) } -> code_info__restore_and_release_hp(HpSlot, Code) ; { Code = empty } ). %---------------------------------------------------------------------------% code_info__save_ticket(Code, TicketSlot) --> code_info__acquire_temp_slot(ticket, TicketSlot), { Code = node([ store_ticket(TicketSlot) - "Save trail state" ]) }. code_info__reset_ticket(TicketSlot, Reason, Code) --> { Code = node([ reset_ticket(lval(TicketSlot), Reason) - "Reset trail" ]) }. code_info__release_ticket(TicketSlot) --> code_info__release_temp_slot(TicketSlot). code_info__reset_and_prune_ticket(TicketSlot, Reason, Code) --> { Code = node([ reset_ticket(lval(TicketSlot), Reason) - "Restore trail", prune_ticket - "Prune ticket stack" ]) }. code_info__reset_prune_and_release_ticket(TicketSlot, Reason, Code) --> { Code = node([ reset_ticket(lval(TicketSlot), Reason) - "Release trail", prune_ticket - "Prune ticket stack" ]) }, code_info__release_temp_slot(TicketSlot). code_info__reset_and_discard_ticket(TicketSlot, Reason, Code) --> { Code = node([ reset_ticket(lval(TicketSlot), Reason) - "Restore trail", discard_ticket - "Pop ticket stack" ]) }. code_info__reset_discard_and_release_ticket(TicketSlot, Reason, Code) --> { Code = node([ reset_ticket(lval(TicketSlot), Reason) - "Release trail", discard_ticket - "Pop ticket stack" ]) }, code_info__release_temp_slot(TicketSlot). %---------------------------------------------------------------------------% code_info__maybe_save_ticket(Maybe, Code, MaybeTicketSlot) --> ( { Maybe = yes } -> code_info__save_ticket(Code, TicketSlot), { MaybeTicketSlot = yes(TicketSlot) } ; { Code = empty }, { MaybeTicketSlot = no } ). code_info__maybe_reset_ticket(MaybeTicketSlot, Reason, Code) --> ( { MaybeTicketSlot = yes(TicketSlot) } -> code_info__reset_ticket(TicketSlot, Reason, Code) ; { Code = empty } ). code_info__maybe_release_ticket(MaybeTicketSlot) --> ( { MaybeTicketSlot = yes(TicketSlot) } -> code_info__release_ticket(TicketSlot) ; [] ). code_info__maybe_reset_and_prune_ticket(MaybeTicketSlot, Reason, Code) --> ( { MaybeTicketSlot = yes(TicketSlot) } -> code_info__reset_and_prune_ticket(TicketSlot, Reason, Code) ; { Code = empty } ). code_info__maybe_reset_prune_and_release_ticket(MaybeTicketSlot, Reason, Code) --> ( { MaybeTicketSlot = yes(TicketSlot) } -> code_info__reset_prune_and_release_ticket(TicketSlot, Reason, Code) ; { Code = empty } ). code_info__maybe_reset_and_discard_ticket(MaybeTicketSlot, Reason, Code) --> ( { MaybeTicketSlot = yes(TicketSlot) } -> code_info__reset_and_discard_ticket(TicketSlot, Reason, Code) ; { Code = empty } ). code_info__maybe_reset_discard_and_release_ticket(MaybeTicketSlot, Reason, Code) --> ( { MaybeTicketSlot = yes(TicketSlot) } -> code_info__reset_discard_and_release_ticket(TicketSlot, Reason, Code) ; { Code = empty } ). %---------------------------------------------------------------------------% %---------------------------------------------------------------------------% % Submodule to deal with code_exprn. :- interface. :- pred code_info__variable_locations(map(prog_var, set(lval))::out, code_info::in, code_info::out) is det. :- pred code_info__set_var_location(prog_var::in, lval::in, code_info::in, code_info::out) is det. :- pred code_info__assign_var_to_var(prog_var::in, prog_var::in, code_info::in, code_info::out) is det. :- pred code_info__assign_lval_to_var(prog_var::in, lval::in, code_tree::out, code_info::in, code_info::out) is det. :- pred code_info__assign_const_to_var(prog_var::in, rval::in, code_info::in, code_info::out) is det. :- pred code_info__assign_expr_to_var(prog_var::in, rval::in, code_tree::out, code_info::in, code_info::out) is det. :- pred code_info__assign_cell_to_var(prog_var::in, tag::in, list(maybe(rval))::in, string::in, code_tree::out, code_info::in, code_info::out) is det. :- pred code_info__place_var(prog_var::in, lval::in, code_tree::out, code_info::in, code_info::out) is det. :- pred code_info__produce_variable(prog_var::in, code_tree::out, rval::out, code_info::in, code_info::out) is det. :- pred code_info__produce_variable_in_reg(prog_var::in, code_tree::out, lval::out, code_info::in, code_info::out) is det. :- pred code_info__produce_variable_in_reg_or_stack(prog_var::in, code_tree::out, lval::out, code_info::in, code_info::out) is det. :- pred code_info__materialize_vars_in_rval(rval::in, rval::out, code_tree::out, code_info::in, code_info::out) is det. :- pred code_info__acquire_reg_for_var(prog_var::in, lval::out, code_info::in, code_info::out) is det. :- pred code_info__acquire_reg(reg_type::in, lval::out, code_info::in, code_info::out) is det. :- pred code_info__release_reg(lval::in, code_info::in, code_info::out) is det. :- pred code_info__reserve_r1(code_tree::out, code_info::in, code_info::out) is det. :- pred code_info__clear_r1(code_tree::out, code_info::in, code_info::out) is det. :- type call_direction ---> caller ; callee. % Move variables to where they need to be at the time of the call: % % - The variables that need to be saved across the call (either because % they are forward live after the call or because they are protected % by an enclosing resumption point) will be saved on the stack. % % - The input arguments will be moved to their registers. :- pred code_info__setup_call(hlds_goal_info::in, assoc_list(prog_var, arg_info)::in, set(lval)::out, code_tree::out, code_info::in, code_info::out) is det. % Move the output arguments of the current procedure to where % they need to be at return. :- pred code_info__setup_return(assoc_list(prog_var, arg_info)::in, set(lval)::out, code_tree::out, code_info::in, code_info::out) is det. :- pred code_info__eager_lock_regs(int::in, assoc_list(prog_var, lval)::in, code_info::in, code_info::out) is det. :- pred code_info__eager_unlock_regs(code_info::in, code_info::out) is det. :- pred code_info__clear_all_registers(code_info::in, code_info::out) is det. :- pred code_info__clobber_regs(list(lval)::in, code_info::in, code_info::out) is det. :- pred code_info__save_variables(set(prog_var)::in, set(lval)::out, code_tree::out, code_info::in, code_info::out) is det. :- pred code_info__save_variables_on_stack(list(prog_var)::in, code_tree::out, code_info::in, code_info::out) is det. :- pred code_info__max_reg_in_use(int::out, code_info::in, code_info::out) is det. %---------------------------------------------------------------------------% :- implementation. :- pred code_info__pick_and_place_vars(assoc_list(prog_var, set(lval))::in, set(lval)::out, code_tree::out, code_info::in, code_info::out) is det. :- pred code_info__place_vars(assoc_list(prog_var, lval)::in, code_tree::out, code_info::in, code_info::out) is det. code_info__variable_locations(Lvals) --> code_info__get_var_locns_info(VarInfo), { VarInfo = exprn_info(Exprn), code_exprn__get_varlocs(Exprn, Rvals), Lvals = map__map_values(code_info__rval_map_to_lval_map, Rvals) ; VarInfo = var_locn_info(VarLocn), var_locn__get_var_locations(VarLocn, Lvals) }. :- func code_info__rval_map_to_lval_map(prog_var, set(rval)) = set(lval). code_info__rval_map_to_lval_map(_Var, Rvals) = set__filter_map(code_info__rval_is_lval, Rvals). :- func code_info__rval_is_lval(rval) = lval is semidet. code_info__rval_is_lval(lval(Lval)) = Lval. code_info__set_var_location(Var, Lval) --> code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(Exprn0), code_exprn__set_var_location(Var, Lval, Exprn0, Exprn), VarInfo = exprn_info(Exprn) ; VarInfo0 = var_locn_info(VarLocn0), var_locn__check_and_set_magic_var_location(Var, Lval, VarLocn0, VarLocn), VarInfo = var_locn_info(VarLocn) }, code_info__set_var_locns_info(VarInfo). code_info__assign_var_to_var(Var, AssignedVar) --> code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(Exprn0), code_exprn__cache_exprn(Var, var(AssignedVar), Exprn0, Exprn), VarInfo = exprn_info(Exprn) ; VarInfo0 = var_locn_info(VarLocInfo0), var_locn__assign_var_to_var(Var, AssignedVar, VarLocInfo0, VarLocInfo), VarInfo = var_locn_info(VarLocInfo) }, code_info__set_var_locns_info(VarInfo). code_info__assign_lval_to_var(Var, Lval, Code) --> code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(Exprn0), code_exprn__cache_exprn(Var, lval(Lval), Exprn0, Exprn), Code = empty, VarInfo = exprn_info(Exprn) ; VarInfo0 = var_locn_info(VarLocInfo0), var_locn__assign_lval_to_var(Var, Lval, Code, VarLocInfo0, VarLocInfo), VarInfo = var_locn_info(VarLocInfo) }, code_info__set_var_locns_info(VarInfo). code_info__assign_const_to_var(Var, ConstRval) --> code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(Exprn0), code_exprn__cache_exprn(Var, ConstRval, Exprn0, Exprn), VarInfo = exprn_info(Exprn) ; VarInfo0 = var_locn_info(VarLocInfo0), var_locn__assign_const_to_var(Var, ConstRval, VarLocInfo0, VarLocInfo), VarInfo = var_locn_info(VarLocInfo) }, code_info__set_var_locns_info(VarInfo). code_info__assign_expr_to_var(Var, Rval, Code) --> code_info__get_var_locns_info(VarInfo0), { code_util__lvals_in_rval(Rval, Lvals), Lvals = [] -> ( VarInfo0 = exprn_info(Exprn0), code_exprn__cache_exprn(Var, Rval, Exprn0, Exprn), VarInfo = exprn_info(Exprn), Code = empty ; VarInfo0 = var_locn_info(VarLocInfo0), var_locn__assign_expr_to_var(Var, Rval, Code, VarLocInfo0, VarLocInfo), VarInfo = var_locn_info(VarLocInfo) ) ; error("code_info__assign_expr_to_var: non-var lvals") }, code_info__set_var_locns_info(VarInfo). code_info__assign_cell_to_var(Var, Ptag, Vector, TypeMsg, Code) --> code_info__get_var_locns_info(VarInfo0), code_info__get_next_cell_number(CellNum), { VarInfo0 = exprn_info(Exprn0), % XXX Later we will need to worry about % whether the cell must be unique or not. Reuse = no, Rval = create(Ptag, Vector, uniform(no), can_be_either, CellNum, TypeMsg, Reuse), code_exprn__cache_exprn(Var, Rval, Exprn0, Exprn), VarInfo = exprn_info(Exprn), Code = empty ; VarInfo0 = var_locn_info(VarLocInfo0), var_locn__assign_cell_to_var(Var, Ptag, Vector, CellNum, TypeMsg, Code, VarLocInfo0, VarLocInfo), VarInfo = var_locn_info(VarLocInfo) }, code_info__set_var_locns_info(VarInfo). code_info__place_var(Var, Lval, Code) --> code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(Exprn0), code_exprn__place_var(Var, Lval, Code, Exprn0, Exprn), VarInfo = exprn_info(Exprn) ; VarInfo0 = var_locn_info(VarLocn0), var_locn__place_var(Var, Lval, Code, VarLocn0, VarLocn), VarInfo = var_locn_info(VarLocn) }, code_info__set_var_locns_info(VarInfo). code_info__pick_and_place_vars(VarLocSets, LiveLocs, Code) --> { code_info__pick_var_places(VarLocSets, VarLocs) }, { assoc_list__values(VarLocs, Locs) }, { set__list_to_set(Locs, LiveLocs) }, code_info__place_vars(VarLocs, Code). :- pred code_info__pick_var_places(assoc_list(prog_var, set(lval))::in, assoc_list(prog_var, lval)::out) is det. code_info__pick_var_places([], []). code_info__pick_var_places([Var - LvalSet | VarLvalSets], VarLvals) :- code_info__pick_var_places(VarLvalSets, VarLvals0), ( set__to_sorted_list(LvalSet, LvalList), LvalList = [Lval | _] -> VarLvals = [Var - Lval | VarLvals0] ; VarLvals = VarLvals0 ). code_info__place_vars(VarLocs, Code) --> code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(Exprn0), code_exprn__place_vars(VarLocs, Code, Exprn0, Exprn), VarInfo = exprn_info(Exprn) ; VarInfo0 = var_locn_info(VarLocn0), var_locn__place_vars(VarLocs, Code, VarLocn0, VarLocn), VarInfo = var_locn_info(VarLocn) }, code_info__set_var_locns_info(VarInfo). code_info__produce_variable(Var, Code, Rval) --> code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(Exprn0), code_exprn__produce_var(Var, Rval, Code, Exprn0, Exprn), VarInfo = exprn_info(Exprn) ; VarInfo0 = var_locn_info(VarLocn0), var_locn__produce_var(Var, Rval, Code, VarLocn0, VarLocn), VarInfo = var_locn_info(VarLocn) }, code_info__set_var_locns_info(VarInfo). code_info__produce_variable_in_reg(Var, Code, Lval) --> code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(Exprn0), code_exprn__produce_var_in_reg(Var, Lval, Code, Exprn0, Exprn), VarInfo = exprn_info(Exprn) ; VarInfo0 = var_locn_info(VarLocn0), var_locn__produce_var_in_reg(Var, Lval, Code, VarLocn0, VarLocn), VarInfo = var_locn_info(VarLocn) }, code_info__set_var_locns_info(VarInfo). code_info__produce_variable_in_reg_or_stack(Var, Code, Lval) --> code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(Exprn0), code_exprn__produce_var_in_reg_or_stack(Var, Lval, Code, Exprn0, Exprn), VarInfo = exprn_info(Exprn) ; VarInfo0 = var_locn_info(VarLocn0), var_locn__produce_var_in_reg_or_stack(Var, Lval, Code, VarLocn0, VarLocn), VarInfo = var_locn_info(VarLocn) }, code_info__set_var_locns_info(VarInfo). code_info__materialize_vars_in_rval(Rval0, Rval, Code) --> code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(Exprn0), code_exprn__materialize_vars_in_rval(Rval0, Rval, Code, Exprn0, Exprn), VarInfo = exprn_info(Exprn) ; VarInfo0 = var_locn_info(VarLocnInfo0), ( Rval0 = lval(Lval0) -> var_locn__materialize_vars_in_lval(Lval0, Lval, Code, VarLocnInfo0, VarLocnInfo), Rval = lval(Lval), VarInfo = var_locn_info(VarLocnInfo) ; exprn_aux__vars_in_rval(Rval0, []) -> Rval = Rval0, Code = empty, VarInfo = VarInfo0 ; error("eager code_info__materialize_vars_in_rval") ) }, code_info__set_var_locns_info(VarInfo). code_info__acquire_reg_for_var(Var, Lval) --> code_info__get_follow_var_map(FollowVarsMap), code_info__get_next_non_reserved(NextNonReserved), code_info__get_var_locns_info(VarInfo0), { map__search(FollowVarsMap, Var, PrefLval), PrefLval = reg(PrefRegType, PrefRegNum), PrefRegNum >= 1 -> ( VarInfo0 = exprn_info(Exprn0), code_exprn__acquire_reg_prefer_given(PrefRegType, PrefRegNum, Lval, Exprn0, Exprn), VarInfo = exprn_info(Exprn) ; VarInfo0 = var_locn_info(VarLocn0), require(unify(PrefRegType, r), "acquire non-r reg"), var_locn__acquire_reg_prefer_given(PrefRegNum, Lval, VarLocn0, VarLocn), VarInfo = var_locn_info(VarLocn) ) ; % XXX We should only get a register if the map__search % succeeded; otherwise we should put the var in its stack slot. ( VarInfo0 = exprn_info(Exprn0), code_exprn__acquire_reg(r, Lval, Exprn0, Exprn), VarInfo = exprn_info(Exprn) ; VarInfo0 = var_locn_info(VarLocn0), var_locn__acquire_reg_start_at_given( NextNonReserved, Lval, VarLocn0, VarLocn), VarInfo = var_locn_info(VarLocn) ) }, code_info__set_var_locns_info(VarInfo). code_info__acquire_reg(Type, Lval) --> code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(Exprn0), code_exprn__acquire_reg(Type, Lval, Exprn0, Exprn), VarInfo = exprn_info(Exprn) ; VarInfo0 = var_locn_info(VarLocnInfo0), require(unify(Type, r), "code_info__acquire_reg: unknown reg type"), var_locn__acquire_reg(Lval, VarLocnInfo0, VarLocnInfo), VarInfo = var_locn_info(VarLocnInfo) }, code_info__set_var_locns_info(VarInfo). code_info__release_reg(Lval) --> code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(Exprn0), code_exprn__release_reg(Lval, Exprn0, Exprn), VarInfo = exprn_info(Exprn) ; VarInfo0 = var_locn_info(VarLocnInfo0), var_locn__release_reg(Lval, VarLocnInfo0, VarLocnInfo), VarInfo = var_locn_info(VarLocnInfo) }, code_info__set_var_locns_info(VarInfo). code_info__reserve_r1(Code) --> code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(_Exprn0), VarInfo = VarInfo0, Code = empty ; VarInfo0 = var_locn_info(VarLocnInfo0), var_locn__clear_r1(Code, VarLocnInfo0, VarLocnInfo1), var_locn__acquire_reg_require_given(reg(r, 1), VarLocnInfo1, VarLocnInfo), VarInfo = var_locn_info(VarLocnInfo) }, code_info__set_var_locns_info(VarInfo). code_info__clear_r1(Code) --> code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(Exprn0), code_exprn__clear_r1(Code, Exprn0, Exprn), VarInfo = exprn_info(Exprn) ; VarInfo0 = var_locn_info(VarLocnInfo0), var_locn__release_reg(reg(r, 1), VarLocnInfo0, VarLocnInfo), VarInfo = var_locn_info(VarLocnInfo), Code = empty }, code_info__set_var_locns_info(VarInfo). %---------------------------------------------------------------------------% code_info__setup_return(VarArgInfos, OutLocs, Code) --> code_info__setup_call_args(VarArgInfos, callee, OutLocs, Code). code_info__setup_call(GoalInfo, ArgInfos, LiveLocs, Code) --> { partition_args(ArgInfos, InArgInfos, OutArgInfos, _UnusedArgInfos) }, { assoc_list__keys(OutArgInfos, OutVars) }, { set__list_to_set(OutVars, OutVarSet) }, code_info__compute_forward_live_var_saves(OutVarSet, ForwardVarLocs), { goal_info_get_code_model(GoalInfo, CodeModel) }, ( { CodeModel = model_non } -> % Save variables protected by the nearest resumption % point on the stack. XXX This should be unnecessary; % with the current setup, the code that established % the resume point should have saved those variables % on the stack already. However, later we should % arrange things so that this saving of the resume vars % on the stack is delayed until the first call after % the setup of the resume point. code_info__compute_resume_var_stack_locs(ResumeVarLocs), { list__append(ResumeVarLocs, ForwardVarLocs, StackVarLocs) } ; { StackVarLocs = ForwardVarLocs } ), code_info__get_var_locns_info(VarInfo0), ( { VarInfo0 = exprn_info(_) }, code_info__place_vars(StackVarLocs, StackCode), { assoc_list__values(StackVarLocs, StackLocs) }, { set__list_to_set(StackLocs, StackLiveLocs) }, code_info__setup_call_args_lazy(InArgInfos, caller, ArgLiveLocs, ArgCode), { set__union(StackLiveLocs, ArgLiveLocs, LiveLocs) }, { Code = tree(StackCode, ArgCode) } ; { VarInfo0 = var_locn_info(VarLocnInfo0) }, { code_info__var_arg_info_to_lval(InArgInfos, InArgLocs) }, { list__append(StackVarLocs, InArgLocs, AllLocs) }, { var_locn__place_vars(AllLocs, Code, VarLocnInfo0, VarLocnInfo) }, code_info__set_var_locns_info(var_locn_info(VarLocnInfo)), { assoc_list__values(AllLocs, LiveLocList) }, { set__list_to_set(LiveLocList, LiveLocs) } % { assoc_list__keys(InArgLocs, InArgVars) }, % { set__init(DeadVars0) }, % code_info__which_variables_are_forward_live(InArgVars, % DeadVars0, DeadVars), % code_info__make_vars_forward_dead(DeadVars) ). :- pred code_info__setup_call_args(assoc_list(prog_var, arg_info)::in, call_direction::in, set(lval)::out, code_tree::out, code_info::in, code_info::out) is det. code_info__setup_call_args(VarArgInfos, Direction, LiveLocs, Code) --> code_info__get_var_locns_info(VarInfo0), ( { VarInfo0 = exprn_info(_) }, code_info__setup_call_args_lazy(VarArgInfos, Direction, LiveLocs, Code) ; { VarInfo0 = var_locn_info(_) }, code_info__setup_call_args_eager(VarArgInfos, Direction, LiveLocs, Code) ). :- pred code_info__setup_call_args_eager(assoc_list(prog_var, arg_info)::in, call_direction::in, set(lval)::out, code_tree::out, code_info::in, code_info::out) is det. code_info__setup_call_args_eager(AllArgsInfos, Direction, LiveLocs, Code) --> { list__filter(code_info__call_arg_in_selected_dir(Direction), AllArgsInfos, ArgsInfos) }, { code_info__var_arg_info_to_lval(ArgsInfos, ArgsLocns) }, code_info__get_eager_var_locns_info(VarLocnInfo0), { var_locn__place_vars(ArgsLocns, Code, VarLocnInfo0, VarLocnInfo1) }, code_info__set_var_locns_info(var_locn_info(VarLocnInfo1)), { assoc_list__values(ArgsLocns, LiveLocList) }, { set__list_to_set(LiveLocList, LiveLocs) }, { assoc_list__keys(ArgsLocns, ArgVars) }, { set__init(DeadVars0) }, code_info__which_variables_are_forward_live(ArgVars, DeadVars0, DeadVars), code_info__make_vars_forward_dead(DeadVars). :- pred code_info__var_arg_info_to_lval(assoc_list(prog_var, arg_info)::in, assoc_list(prog_var, lval)::out) is det. code_info__var_arg_info_to_lval([], []). code_info__var_arg_info_to_lval([Var - ArgInfo | RestInfos], [Var - Lval | RestLvals]) :- ArgInfo = arg_info(Loc, _Mode), code_util__arg_loc_to_register(Loc, Lval), code_info__var_arg_info_to_lval(RestInfos, RestLvals). :- pred code_info__which_variables_are_forward_live(list(prog_var)::in, set(prog_var)::in, set(prog_var)::out, code_info::in, code_info::out) is det. code_info__which_variables_are_forward_live([], DeadVars, DeadVars) --> []. code_info__which_variables_are_forward_live([Var | Vars], DeadVars0, DeadVars) --> ( code_info__variable_is_forward_live(Var) -> { DeadVars1 = DeadVars0 } ; { set__insert(DeadVars0, Var, DeadVars1) } ), code_info__which_variables_are_forward_live(Vars, DeadVars1, DeadVars). :- pred code_info__setup_call_args_lazy(assoc_list(prog_var, arg_info)::in, call_direction::in, set(lval)::out, code_tree::out, code_info::in, code_info::out) is det. code_info__setup_call_args_lazy([], _Direction, set__init, empty) --> []. code_info__setup_call_args_lazy([First | Rest], Direction, LiveLocs, Code) --> ( { code_info__call_arg_in_selected_dir(Direction, First) } -> { First = V - arg_info(Loc, _Mode) }, { code_util__arg_loc_to_register(Loc, Reg) }, code_info__get_lazy_var_locns_info(Exprn0), { code_exprn__place_var(V, Reg, Code0, Exprn0, Exprn1) }, % We need to test that either the variable % is live OR it occurs in the remaining arguments % because of a bug in polymorphism.m which % causes some compiler generated code to violate % superhomogeneous form ( code_info__variable_is_forward_live(V) -> { IsLive = yes } ; { IsLive = no } ), { list__member(Vtmp - _, Rest), V = Vtmp -> Occurs = yes ; Occurs = no }, ( % We can't simply use a disj here % because of bugs in modes/det_analysis { bool__or(Occurs, IsLive, yes) } -> { code_exprn__lock_reg(Reg, Exprn1, Exprn2) }, code_info__set_var_locns_info(exprn_info(Exprn2)), code_info__setup_call_args_lazy(Rest, Direction, LiveLocs1, Code1), code_info__get_lazy_var_locns_info(Exprn3), { code_exprn__unlock_reg(Reg, Exprn3, Exprn) }, code_info__set_var_locns_info(exprn_info(Exprn)), { Code = tree(Code0, Code1) } ; { code_exprn__lock_reg(Reg, Exprn1, Exprn2) }, code_info__set_var_locns_info(exprn_info(Exprn2)), { set__singleton_set(Vset, V) }, code_info__make_vars_forward_dead(Vset), code_info__setup_call_args_lazy(Rest, Direction, LiveLocs1, Code1), code_info__get_lazy_var_locns_info(Exprn4), { code_exprn__unlock_reg(Reg, Exprn4, Exprn) }, code_info__set_var_locns_info(exprn_info(Exprn)), { Code = tree(Code0, Code1) } ), { set__insert(LiveLocs1, Reg, LiveLocs) } ; code_info__setup_call_args_lazy(Rest, Direction, LiveLocs, Code) ). :- pred code_info__call_arg_in_selected_dir(call_direction::in, pair(prog_var, arg_info)::in) is semidet. code_info__call_arg_in_selected_dir(Direction, _ - arg_info(_, Mode)) :- ( Mode = top_in, Direction = caller ; Mode = top_out, Direction = callee ). code_info__eager_lock_regs(N, Exceptions) --> code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(_), VarInfo = VarInfo0 ; VarInfo0 = var_locn_info(VarLocnInfo0), var_locn__lock_regs(N, Exceptions, VarLocnInfo0, VarLocnInfo), VarInfo = var_locn_info(VarLocnInfo) }, code_info__set_var_locns_info(VarInfo). code_info__eager_unlock_regs --> code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(_), VarInfo = VarInfo0 ; VarInfo0 = var_locn_info(VarLocnInfo0), var_locn__unlock_regs(VarLocnInfo0, VarLocnInfo), VarInfo = var_locn_info(VarLocnInfo) }, code_info__set_var_locns_info(VarInfo). :- pred code_info__get_eager_var_locns_info(var_locn_info::out, code_info::in, code_info::out) is det. code_info__get_eager_var_locns_info(VarLocnInfo) --> code_info__get_var_locns_info(VarInfo), { VarInfo = exprn_info(_), error("lazy code_info__get_eager_var_locns_info") ; VarInfo = var_locn_info(VarLocnInfo) }. :- pred code_info__get_lazy_var_locns_info(exprn_info::out, code_info::in, code_info::out) is det. code_info__get_lazy_var_locns_info(Exprn) --> code_info__get_var_locns_info(VarInfo), { VarInfo = exprn_info(Exprn) ; VarInfo = var_locn_info(_), error("eager code_info__get_lazy_var_locns_info") }. % As a sanity check, we could test whether any known variable % has its only value in a register, but we do so only with eager % code generation. code_info__clear_all_registers --> code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(Exprn0), code_exprn__clobber_regs([], Exprn0, Exprn), VarInfo = exprn_info(Exprn) ; VarInfo0 = var_locn_info(VarLocn0), var_locn__clobber_all_regs(VarLocn0, VarLocn), VarInfo = var_locn_info(VarLocn) }, code_info__set_var_locns_info(VarInfo). code_info__clobber_regs(Regs) --> code_info__get_var_locns_info(VarInfo0), { VarInfo0 = exprn_info(_Exprn0), % The clobber_regs predicate has no function except to ensure % that sanity check in eager code generation does not fail % when it shouldn't. Since lazy code generation lacks this % sanity check, it doesn't need to do anything. VarInfo = VarInfo0 ; VarInfo0 = var_locn_info(VarLocn0), var_locn__clobber_regs(Regs, VarLocn0, VarLocn), VarInfo = var_locn_info(VarLocn) }, code_info__set_var_locns_info(VarInfo). code_info__save_variables(OutArgs, SavedLocs, Code) --> code_info__compute_forward_live_var_saves(OutArgs, VarLocs), { assoc_list__values(VarLocs, SavedLocList) }, { set__list_to_set(SavedLocList, SavedLocs) }, code_info__place_vars(VarLocs, Code). code_info__save_variables_on_stack(Vars, Code) --> list__map_foldl(code_info__associate_stack_slot, Vars, VarLocs), code_info__place_vars(VarLocs, Code). :- pred code_info__compute_forward_live_var_saves(set(prog_var)::in, assoc_list(prog_var, lval)::out, code_info::in, code_info::out) is det. code_info__compute_forward_live_var_saves(OutArgs, VarLocs) --> code_info__get_known_variables(Variables0), { set__list_to_set(Variables0, Vars0) }, code_info__body_typeinfo_liveness(TypeInfoLiveness), code_info__get_proc_info(ProcInfo), { proc_info_vartypes(ProcInfo, VarTypes) }, { proc_info_typeinfo_varmap(ProcInfo, TVarMap) }, { proc_info_maybe_complete_with_typeinfo_vars(Vars0, TypeInfoLiveness, VarTypes, TVarMap, Vars1) }, { set__difference(Vars1, OutArgs, Vars) }, { set__to_sorted_list(Vars, Variables) }, list__map_foldl(code_info__associate_stack_slot, Variables, VarLocs). :- pred code_info__associate_stack_slot(prog_var::in, pair(prog_var, lval)::out, code_info::in, code_info::out) is det. code_info__associate_stack_slot(Var, Var - Slot) --> code_info__get_variable_slot(Var, Slot). code_info__max_reg_in_use(Max) --> code_info__get_var_locns_info(VarInfo), { VarInfo = exprn_info(Exprn), code_exprn__max_reg_in_use(Exprn, Max) ; VarInfo = var_locn_info(VarLocn), var_locn__max_reg_in_use(VarLocn, Max) }. %---------------------------------------------------------------------------% %---------------------------------------------------------------------------% % Submodule for dealing with the recording of variable liveness % information around calls. % % Value numbering needs to know what locations are live before calls; % the garbage collector and the debugger need to know what locations % are live containing what types of values after calls. :- interface. :- pred code_info__generate_call_vn_livevals(list(arg_loc)::in, set(prog_var)::in, set(lval)::out, code_info::in, code_info::out) is det. :- pred code_info__generate_return_live_lvalues( assoc_list(prog_var, arg_loc)::in, instmap::in, list(liveinfo)::out, code_info::in, code_info::out) is det. %---------------------------------------------------------------------------% :- implementation. code_info__generate_call_vn_livevals(InputArgLocs, OutputArgs, LiveVals) --> code_info__generate_call_stack_vn_livevals(OutputArgs, StackLiveVals), { code_info__generate_input_var_vn(InputArgLocs, StackLiveVals, LiveVals) }. :- pred code_info__generate_call_stack_vn_livevals(set(prog_var)::in, set(lval)::out, code_info::in, code_info::out) is det. code_info__generate_call_stack_vn_livevals(OutputArgs, LiveVals) --> code_info__get_known_variables(KnownVarList), { set__list_to_set(KnownVarList, KnownVars) }, { set__difference(KnownVars, OutputArgs, LiveVars) }, { set__to_sorted_list(LiveVars, LiveVarList) }, { set__init(LiveVals0) }, code_info__generate_stack_var_vn(LiveVarList, LiveVals0, LiveVals1), code_info__get_active_temps_data(Temps), { code_info__generate_call_temp_vn(Temps, LiveVals1, LiveVals) }. :- pred code_info__generate_stack_var_vn(list(prog_var)::in, set(lval)::in, set(lval)::out, code_info::in, code_info::out) is det. code_info__generate_stack_var_vn([], Vals, Vals) --> []. code_info__generate_stack_var_vn([V | Vs], Vals0, Vals) --> code_info__get_variable_slot(V, Lval), { set__insert(Vals0, Lval, Vals1) }, code_info__generate_stack_var_vn(Vs, Vals1, Vals). :- pred code_info__generate_call_temp_vn(assoc_list(lval, slot_contents)::in, set(lval)::in, set(lval)::out) is det. code_info__generate_call_temp_vn([], Vals, Vals). code_info__generate_call_temp_vn([Lval - _ | Temps], Vals0, Vals) :- set__insert(Vals0, Lval, Vals1), code_info__generate_call_temp_vn(Temps, Vals1, Vals). :- pred code_info__generate_input_var_vn(list(arg_loc)::in, set(lval)::in, set(lval)::out) is det. code_info__generate_input_var_vn([], Vals, Vals). code_info__generate_input_var_vn([InputArgLoc | InputArgLocs], Vals0, Vals) :- code_util__arg_loc_to_register(InputArgLoc, Lval), set__insert(Vals0, Lval, Vals1), code_info__generate_input_var_vn(InputArgLocs, Vals1, Vals). %---------------------------------------------------------------------------% code_info__generate_return_live_lvalues(OutputArgLocs, ReturnInstMap, LiveLvalues) --> code_info__variable_locations(VarLocs), code_info__get_known_variables(Vars), code_info__get_active_temps_data(Temps), code_info__get_proc_info(ProcInfo), code_info__get_globals(Globals), code_info__get_module_info(ModuleInfo), { continuation_info__generate_return_live_lvalues(OutputArgLocs, ReturnInstMap, Vars, VarLocs, Temps, ProcInfo, ModuleInfo, Globals, LiveLvalues) }. :- pred code_info__generate_resume_layout(label::in, resume_map::in, code_info::in, code_info::out) is det. code_info__generate_resume_layout(Label, ResumeMap) --> code_info__get_globals(Globals), { globals__lookup_bool_option(Globals, agc_stack_layout, AgcStackLayout) }, ( { AgcStackLayout = yes } -> code_info__get_active_temps_data(Temps), code_info__get_instmap(InstMap), code_info__get_proc_info(ProcInfo), code_info__get_module_info(ModuleInfo), { continuation_info__generate_resume_layout(ResumeMap, Temps, InstMap, ProcInfo, ModuleInfo, Layout) }, code_info__add_resume_layout_for_label(Label, Layout) ; [] ). %---------------------------------------------------------------------------% %---------------------------------------------------------------------------% % Submodule for managing stack slots. % Det stack frames are organized as follows. % % ... unused ... % sp ---> % % ... local vars ... % % % ... temporaries ... % % % % The stack pointer points to the first free location at the % top of the stack. % % `code_info__succip_is_used' determines whether we need a slot to % hold the succip. % % Nondet stack frames also have the local variables above the % temporaries, but contain several fixed slots on top, and the % saved succip is stored in one of these. % % For both kinds of stack frames, the slots holding variables % are allocated during the live_vars pass, while the slots holding % temporaries are acquired (and if possible, released) on demand % during code generation. :- interface. % Returns the total stackslot count, but not including space for % succip. This total can change in the future if this call is % followed by further allocations of temp slots. :- pred code_info__get_total_stackslot_count(int, code_info, code_info). :- mode code_info__get_total_stackslot_count(out, in, out) is det. % Acquire a stack slot for storing a temporary. The slot_contents % description is for accurate gc. :- pred code_info__acquire_temp_slot(slot_contents, lval, code_info, code_info). :- mode code_info__acquire_temp_slot(in, out, in, out) is det. % Release a stack slot acquired earlier for a temporary value. :- pred code_info__release_temp_slot(lval, code_info, code_info). :- mode code_info__release_temp_slot(in, in, out) is det. % Return the lval of the stack slot in which the given variable % is stored. Aborts if the variable does not have a stack slot % an assigned to it. :- pred code_info__get_variable_slot(prog_var, lval, code_info, code_info). :- mode code_info__get_variable_slot(in, out, in, out) is det. %---------------------------------------------------------------------------% %---------------------------------------------------------------------------% :- implementation. code_info__acquire_temp_slot(Item, StackVar) --> code_info__get_temps_in_use(TempsInUse0), { IsTempUsable = lambda([TempContent::in, Lval::out] is semidet, ( TempContent = Lval - ContentType, ContentType = Item, \+ set__member(Lval, TempsInUse0) )) }, code_info__get_temp_content_map(TempContentMap0), { map__to_assoc_list(TempContentMap0, TempContentList) }, { list__filter_map(IsTempUsable, TempContentList, UsableLvals) }, ( { UsableLvals = [UsableLval | _] }, { StackVar = UsableLval } ; { UsableLvals = [] }, code_info__get_var_slot_count(VarSlots), code_info__get_max_temp_slot_count(TempSlots0), { TempSlots is TempSlots0 + 1 }, { Slot is VarSlots + TempSlots }, code_info__stack_variable(Slot, StackVar), code_info__set_max_temp_slot_count(TempSlots), { map__det_insert(TempContentMap0, StackVar, Item, TempContentMap) }, code_info__set_temp_content_map(TempContentMap) ), { set__insert(TempsInUse0, StackVar, TempsInUse) }, code_info__set_temps_in_use(TempsInUse). code_info__release_temp_slot(StackVar) --> code_info__get_temps_in_use(TempsInUse0), { set__delete(TempsInUse0, StackVar, TempsInUse) }, code_info__set_temps_in_use(TempsInUse). %---------------------------------------------------------------------------% code_info__get_variable_slot(Var, Slot) --> code_info__get_stack_slots(StackSlots), ( { map__search(StackSlots, Var, SlotPrime) } -> { Slot = SlotPrime } ; code_info__variable_to_string(Var, Name), { term__var_to_int(Var, Num) }, { string__int_to_string(Num, NumStr) }, { string__append_list([ "code_info__get_variable_slot: variable `", Name, "' (", NumStr, ") not found"], Str) }, { error(Str) } ). code_info__get_total_stackslot_count(NumSlots) --> code_info__get_var_slot_count(SlotsForVars), code_info__get_max_temp_slot_count(SlotsForTemps), { NumSlots is SlotsForVars + SlotsForTemps }. :- pred code_info__max_var_slot(stack_slots, int). :- mode code_info__max_var_slot(in, out) is det. code_info__max_var_slot(StackSlots, SlotCount) :- map__values(StackSlots, StackSlotList), code_info__max_var_slot_2(StackSlotList, 0, SlotCount). :- pred code_info__max_var_slot_2(list(lval), int, int). :- mode code_info__max_var_slot_2(in, in, out) is det. code_info__max_var_slot_2([], Max, Max). code_info__max_var_slot_2([L | Ls], Max0, Max) :- ( L = stackvar(N) -> int__max(N, Max0, Max1) ; L = framevar(N) -> int__max(N, Max0, Max1) ; Max1 = Max0 ), code_info__max_var_slot_2(Ls, Max1, Max). :- pred code_info__stack_variable(int, lval, code_info, code_info). :- mode code_info__stack_variable(in, out, in, out) is det. code_info__stack_variable(Num, Lval) --> code_info__get_proc_model(CodeModel), ( { CodeModel = model_non } -> { Lval = framevar(Num) } ; { Lval = stackvar(Num) } ). :- pred code_info__stack_variable_reference(int, rval, code_info, code_info). :- mode code_info__stack_variable_reference(in, out, in, out) is det. code_info__stack_variable_reference(Num, mem_addr(Ref)) --> code_info__get_proc_model(CodeModel), ( { CodeModel = model_non } -> { Ref = framevar_ref(Num) } ; { Ref = stackvar_ref(Num) } ). %---------------------------------------------------------------------------% %---------------------------------------------------------------------------%