Files
mercury/compiler/code_gen.m
Zoltan Somogyi d609181cb9 Consider types of the form
Estimated hours taken: 30
Branches: main

Consider types of the form

	:- type x ---> f.

to be dummy types, since they contain no information. Optimize them the same
way we currently optimize io.state and store.store.

runtime/mercury_type_info.h:
	Add a new type_ctor_rep for dummy types.

runtime/mercury_tabling.h:
	Add a representation for "tabled" dummy types, which don't actually
	have a level in the trie, so that the runtime system can handle that
	fact.

runtime/mercury_ml_expand_body.h:
	When deconstructing a value of a dummy type, ignore the actual value
	(since it will contain garbage) and instead return the only possible
	value of the type.

runtime/mercury_construct.c:
runtime/mercury_deconstruct.c:
runtime/mercury_deep_copy_body.c:
runtime/mercury_tabling.c:
runtime/mercury_unify_compare_body.h:
library/rtti_implementation.m:
	Handle the type_ctor_rep of dummy types.

runtime/mercury_builtin_types.c:
	Provide a place to record profiling information about unifications and
	comparisons for dummy types.

runtime/mercury_mcpp.h:
java/runtime/TypeCtorRep.java:
library/private_builtin.m:
	Add a new type_ctor_rep for dummy types, and fix some previous
	discrepancies in type_ctor_reps.

mdbcomp/prim_data.m:
	Move a bunch of predicates for manipulating special_pred_ids here from
	the browser and compiler directories.

	Rename the function symbols of the special_pred_id type to avoid the
	need to parenthesize the old `initialise' function symbol.

	Convert to four-space indentation.

mdbcomp/rtti_access.m:
	Don't hardcode the names of special preds: use the predicates in
	prim_data.m.

	Convert to four-space indentation.

browser/declarative_execution.m:
	Delete some predicates whose functionality is now in
	mdbcomp/prim_data.m.

compiler/hlds_data.m:
	Replace the part of du type that says whether a type an enum, which
	used to be a bool, with something that also says whether the type is a
	dummy type.

	Convert to four-space indentation.

compiler/make_tags.m:
	Compute the value for the new field of du type definitions.

compiler/hlds_out.m:
	Write out the new field of du type definitions.

compiler/rtti.m:
	Modify the data structures we use to create type_ctor_infos to allow
	for dummy types.

	Convert to four-space indentation.

compiler/type_ctor_info.m:
	Modify the code that generates type_ctor_infos to handle dummy types.

compiler/type_util.m:
	Provide predicates for recognizing dummy types.

	Convert to four-space indentation.

compiler/unify_proc.m:
	Generate the unify and compare predicates of dummy types using a new
	code scheme that avoids referencing arguments that contain garbage.

	When generating code for unifying or comparing other types, ignore
	any arguments of function symbols that are dummy types.

	Don't use DCG style access predicates.

compiler/higher_order.m:
	Specialize the unification and comparison of values of dummy types.

	Break up an excessively large predicate, and factor out common code
	from the conditions of a chain of if-then-elses.

compiler/llds.m:
	For each input and output of a foreign_proc, include a field saying
	whether the value is of a dummy type.

compiler/pragma_c_gen.m:
	Fill in the new fields in foreign_proc arguments.

compiler/hlds_goal.m:
	Rename some predicates for constructing unifications to avoid
	unnecessary ad-hoc overloading. Clarify their documentation.

	Rename a predicate to make clear the restriction on its use,
	and document the restriction.

	Add a predicate for creating simple tests.

	Add a utility predicate for setting the context of a goal directly.

compiler/modules.m:
	Include dummy types interface files, even if they are private to the
	module. This is necessary because with the MLDS backend, the generated
	code inside the module and outside the module must agree whether a
	function returning a value of the type returns a real value or a void
	value, and this requires them to agree on whether the type is dummy
	or not.

	The impact on interface files is minimal, since very few types are
	dummy types, and changing a type from a dummy type to a non-dummy type
	or vice versa is an ever rarer change.

compiler/hlds_pred.m:
	Provide a representation in the compiler of the trie step for dummy
	types.

compiler/layout_out.m:
	Print the trie step for dummy types.

compiler/table_gen.m:
	Don't table values of dummy types, and record the fact that we don't
	by including a dummy trie step in the list of trie steps.

compiler/add_pragma.m:
compiler/add_special_pred.m:
compiler/add_type.m:
compiler/aditi_builtin_ops.m:
compiler/bytecode.m:
compiler/bytecode_gen.m:
compiler/code_gen.m:
compiler/code_info.m:
compiler/continuation_info.m:
compiler/cse_detection.m:
compiler/det_report.m:
compiler/exception_analysis.m:
compiler/inst_match.m:
compiler/livemap.m:
compiler/llds_out.m:
compiler/llds_out.m:
compiler/middle_rec.m:
compiler/ml_call_gen.m:
compiler/ml_closure_gen.m:
compiler/ml_code_gen.m:
compiler/ml_code_util.m:
compiler/ml_type_gen.m:
compiler/ml_unify_gen.m:
compiler/mlds_to_c.m:
compiler/mlds_to_gcc.m:
compiler/mlds_to_il.m:
compiler/mlds_to_il.m:
compiler/modecheck_unify.m:
compiler/modes.m:
compiler/opt_util.m:
compiler/post_term_analysis.m:
compiler/post_typecheck.m:
compiler/qual_info.m:
compiler/rl.m:
compiler/rl_exprn.m:
compiler/rl_key.m:
compiler/rtti_out.m:
compiler/simplify.m:
compiler/size_prof.m:
compiler/term_constr_initial.m:
compiler/term_constr_util.m:
compiler/term_norm.m:
compiler/termination.m:
compiler/trace.m:
compiler/typecheck.m:
compiler/unify_gen.m:
	Conform to the changes above.

compiler/export.m:
compiler/exprn_aux.m:
compiler/foreign.m:
compiler/polymorphism.m:
compiler/proc_label.m:
compiler/rtti_to_mlds.m:
compiler/special_pred.m:
compiler/stack_alloc.m:
compiler/stack_layout.m:
compiler/state_var.m:
compiler/switch_util.m:
compiler/trace_params.m:
	Conform to the changes above.

	Convert to four-space indentation.

compiler/mlds_to_java.m:
compiler/var_locn.m:
	Conform to the changes above, which requires threading the module_info
	through the module.

	Convert to four-space indentation.

compiler/mercury_compile.m:
	Pass the module_info to mlds_to_java.m.

compiler/ml_util.m:
compiler/polymorphism.m:
compiler/type_ctor_info.m:
compiler/type_util.m:
	Delete some previously missed references to the temporary types used
	to bootstrap the change to the type_info type's arity.

compiler/polymorphism.m:
	Turn back on an optimization that avoids passing parameters (such as
	type_infos) to foreign_procs if they are not actually referred to.

compiler/prog_data.m:
	Convert to four-space indentation.

library/svvarset.m:
	Add a missing predicate.

trace/mercury_trace.c:
	Delete the unused function that used to check for dummy types.

tests/debugger/field_names.{m,inp,exp}:
	Add to this test case a test of the handling of dummy types. Check that
	their values can be printed out during normal execution, and that the
	debugger doesn't consider them live nondummy variables, just as it
	doesn't consider I/O states live nondummy variables.
2005-10-05 06:34:27 +00:00

1385 lines
56 KiB
Mathematica

%---------------------------------------------------------------------------%
% vim: ft=mercury ts=4 sw=4 et
%---------------------------------------------------------------------------%
% Copyright (C) 1994-2005 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.
%---------------------------------------------------------------------------%
%
% Code generation - convert from HLDS to LLDS.
%
% Main authors: conway, zs.
%
% The two main tasks of this module are
%
% 1 to look after the aspects of generating code for a procedure
% that do not involve generating code for a specific goal, and
%
% 2 to provide a generic predicate that can be called from anywhere in
% the code generator to generate code for a goal.
%
% Code_gen forwards most of the actual construction of code for particular
% goals to other modules. The generation of code for unifications is done
% by unify_gen, for calls, higher-order calls and method calls by call_gen,
% for commits by commit_gen, for if-then-elses and negations by ite_gen,
% for switches by switch_gen and its subsidiary modules, for disjunctions
% by disj_gen, and for pragma_c_codes by pragma_c_gen. The only kind of goal
% handled directly by code_gen is the conjunction.
%
%---------------------------------------------------------------------------%
:- module ll_backend__code_gen.
:- interface.
:- import_module hlds__code_model.
:- import_module hlds__hlds_goal.
:- import_module hlds__hlds_module.
:- import_module hlds__hlds_pred.
:- import_module ll_backend__code_info.
:- import_module ll_backend__global_data.
:- import_module ll_backend__llds.
:- import_module io.
:- import_module list.
% Translate a HLDS module to LLDS.
%
:- pred generate_code(module_info::in, global_data::in, global_data::out,
list(c_procedure)::out, io::di, io::uo) is det.
% Translate a HLDS procedure to LLDS, threading through the data structure
% that records information about layout structures.
%
:- pred generate_proc_code(pred_info::in, proc_info::in,
proc_id::in, pred_id::in, module_info::in,
global_data::in, global_data::out, c_procedure::out) is det.
% Translate a HLDS goal to LLDS.
%
:- pred code_gen__generate_goal(code_model::in, hlds_goal::in, code_tree::out,
code_info::in, code_info::out) is det.
% Return the message that identifies the procedure to pass to
% the incr_sp_push_msg macro in the generated C code.
%
:- func code_gen__push_msg(module_info, pred_id, proc_id) = string.
%---------------------------------------------------------------------------%
%---------------------------------------------------------------------------%
:- implementation.
% Parse tree modules
:- import_module parse_tree__error_util.
:- import_module parse_tree__prog_data.
:- import_module parse_tree__prog_out.
:- import_module parse_tree__prog_util.
% HLDS modules
:- import_module check_hlds__mode_util.
:- import_module check_hlds__type_util.
:- import_module hlds__goal_util.
:- import_module hlds__hlds_llds.
:- import_module hlds__hlds_out.
:- import_module hlds__instmap.
:- import_module hlds__passes_aux.
:- import_module hlds__special_pred.
% LLDS code generator modules.
:- import_module ll_backend__call_gen.
:- import_module ll_backend__code_util.
:- import_module ll_backend__commit_gen.
:- import_module ll_backend__continuation_info.
:- import_module ll_backend__disj_gen.
:- import_module ll_backend__ite_gen.
:- import_module ll_backend__layout.
:- import_module ll_backend__llds_out.
:- import_module ll_backend__middle_rec.
:- import_module ll_backend__par_conj_gen.
:- import_module ll_backend__pragma_c_gen.
:- import_module ll_backend__switch_gen.
:- import_module ll_backend__trace.
:- import_module ll_backend__unify_gen.
% Misc compiler modules
:- import_module backend_libs__builtin_ops.
:- import_module backend_libs__proc_label.
:- import_module backend_libs__rtti.
:- import_module libs__globals.
:- import_module libs__options.
:- import_module libs__trace_params.
:- import_module mdbcomp__prim_data.
% Standard library modules
:- import_module assoc_list.
:- import_module bool.
:- import_module char.
:- import_module counter.
:- import_module int.
:- import_module libs__tree.
:- import_module map.
:- import_module require.
:- import_module set.
:- import_module std_util.
:- import_module string.
:- import_module term.
:- import_module varset.
%---------------------------------------------------------------------------%
generate_code(ModuleInfo0, !GlobalData, Procedures, !IO) :-
% Get a list of all the predicate ids for which we will generate code.
module_info_predids(ModuleInfo0, PredIds),
% Now generate the code for each predicate.
generate_pred_list_code(ModuleInfo0, !GlobalData, PredIds,
Procedures, !IO).
% Translate a list of HLDS predicates to LLDS.
%
:- pred generate_pred_list_code(module_info::in,
global_data::in, global_data::out,
list(pred_id)::in, list(c_procedure)::out, io::di, io::uo) is det.
generate_pred_list_code(_ModuleInfo, !GlobalData, [], [], !IO).
generate_pred_list_code(ModuleInfo, !GlobalData, [PredId | PredIds],
Predicates, !IO) :-
generate_maybe_pred_code(ModuleInfo, !GlobalData, PredId,
Predicates0, !IO),
generate_pred_list_code(ModuleInfo, !GlobalData, PredIds,
Predicates1, !IO),
list__append(Predicates0, Predicates1, Predicates).
:- pred generate_maybe_pred_code(module_info::in,
global_data::in, global_data::out, pred_id::in,
list(c_procedure)::out, io::di, io::uo) is det.
% Note that some of the logic of generate_maybe_pred_code is duplicated
% by mercury_compile__backend_pass_by_preds, so modifications here may
% also need to be repeated there.
%
generate_maybe_pred_code(ModuleInfo, !GlobalData, PredId, Predicates, !IO) :-
module_info_preds(ModuleInfo, PredInfos),
map__lookup(PredInfos, PredId, PredInfo),
ProcIds = pred_info_non_imported_procids(PredInfo),
(
( ProcIds = []
; hlds_pred__pred_info_is_aditi_relation(PredInfo)
)
->
Predicates = []
;
module_info_get_globals(ModuleInfo, Globals),
globals__lookup_bool_option(Globals, very_verbose, VeryVerbose),
(
VeryVerbose = yes,
io__write_string("% Generating code for ", !IO),
hlds_out__write_pred_id(ModuleInfo, PredId, !IO),
io__write_string("\n", !IO),
globals__lookup_bool_option(Globals, statistics, Statistics),
maybe_report_stats(Statistics, !IO)
;
VeryVerbose = no
),
generate_pred_code(ModuleInfo, !GlobalData,
PredId, PredInfo, ProcIds, Predicates)
).
% Translate a HLDS predicate to LLDS.
%
:- pred generate_pred_code(module_info::in, global_data::in, global_data::out,
pred_id::in, pred_info::in, list(proc_id)::in, list(c_procedure)::out)
is det.
generate_pred_code(ModuleInfo, !GlobalData, PredId, PredInfo, ProcIds, Code) :-
generate_proc_list_code(ProcIds, PredId, PredInfo, ModuleInfo,
!GlobalData, [], Code).
% Translate all the procedures of a HLDS predicate to LLDS.
%
:- pred generate_proc_list_code(list(proc_id)::in, pred_id::in, pred_info::in,
module_info::in, global_data::in, global_data::out,
list(c_procedure)::in, list(c_procedure)::out) is det.
generate_proc_list_code([], _PredId, _PredInfo, _ModuleInfo,
!GlobalData, !Procs).
generate_proc_list_code([ProcId | ProcIds], PredId, PredInfo, ModuleInfo0,
!GlobalData, !Procs) :-
pred_info_procedures(PredInfo, ProcInfos),
map__lookup(ProcInfos, ProcId, ProcInfo),
generate_proc_code(PredInfo, ProcInfo, ProcId, PredId, ModuleInfo0,
!GlobalData, Proc),
!:Procs = [Proc | !.Procs],
generate_proc_list_code(ProcIds, PredId, PredInfo, ModuleInfo0,
!GlobalData, !Procs).
%---------------------------------------------------------------------------%
% Values of this type hold information about stack frames that is
% generated when generating prologs and is used in generating epilogs
% and when massaging the code generated for the procedure.
:- type frame_info
---> frame(
int, % Number of slots in frame.
maybe(int), % Slot number of succip if succip is
% present in a general slot.
bool % Is this the frame of a model_non
% proc defined via pragma C code?
).
%---------------------------------------------------------------------------%
generate_proc_code(PredInfo, ProcInfo0, ProcId, PredId, ModuleInfo0,
!GlobalData, Proc) :-
% The modified module_info and proc_info are both discarded
% on return from generate_proc_code.
maybe_set_trace_level(PredInfo, ModuleInfo0, ModuleInfo),
ensure_all_headvars_are_named(ProcInfo0, ProcInfo),
proc_info_interface_determinism(ProcInfo, Detism),
proc_info_interface_code_model(ProcInfo, CodeModel),
proc_info_goal(ProcInfo, Goal),
Goal = _ - GoalInfo,
goal_info_get_follow_vars(GoalInfo, MaybeFollowVars),
(
MaybeFollowVars = yes(FollowVars)
;
MaybeFollowVars = no,
map__init(FollowVarsMap),
FollowVars = abs_follow_vars(FollowVarsMap, 1)
),
module_info_get_globals(ModuleInfo, Globals),
continuation_info__basic_stack_layout_for_proc(PredInfo, Globals,
BasicStackLayout, ForceProcId),
SaveSuccip = BasicStackLayout,
% Initialise the code_info structure. Generate_category_code below will use
% the returned OutsideResumePoint as the entry to the code that handles
% the failure of the procedure, if such code is needed. It is never needed
% for model_det procedures, always needed for model_semi procedures, and
% needed for model_non procedures only if we are doing execution tracing.
global_data_get_static_cell_info(!.GlobalData, StaticCellInfo0),
code_info__init(SaveSuccip, Globals, PredId, ProcId, PredInfo,
ProcInfo, FollowVars, ModuleInfo, StaticCellInfo0,
OutsideResumePoint, TraceSlotInfo, CodeInfo0),
% Generate code for the procedure.
generate_category_code(CodeModel, Goal, OutsideResumePoint,
TraceSlotInfo, CodeTree, MaybeTraceCallLabel, FrameInfo,
CodeInfo0, CodeInfo),
code_info__get_max_reg_in_use_at_trace(CodeInfo, MaxTraceReg),
code_info__get_static_cell_info(CodeInfo, StaticCellInfo),
global_data_set_static_cell_info(StaticCellInfo, !GlobalData),
globals__get_trace_level(Globals, TraceLevel),
code_info__get_created_temp_frame(CodeInfo, CreatedTempFrame),
EffTraceIsNone = eff_trace_level_is_none(PredInfo, ProcInfo, TraceLevel),
(
EffTraceIsNone = no,
CreatedTempFrame = yes,
CodeModel \= model_non
->
% If tracing is enabled, the procedure lives on the det stack and the
% code created any temporary nondet stack frames, then we must have
% reserved a stack slot for storing the value of maxfr; if we didn't,
% a retry command in the debugger from a point in the middle of this
% procedure will do the wrong thing.
proc_info_get_need_maxfr_slot(ProcInfo, HaveMaxfrSlot),
require(unify(HaveMaxfrSlot, yes),
"should have reserved a slot for maxfr, but didn't")
;
true
),
% Turn the code tree into a list.
tree__flatten(CodeTree, FragmentList),
% Now the code is a list of code fragments (== list(instr)),
% so we need to do a level of unwinding to get a flat list.
list__condense(FragmentList, Instructions0),
FrameInfo = frame(TotalSlots, MaybeSuccipSlot, _),
(
MaybeSuccipSlot = yes(SuccipSlot),
% The set of recorded live values at calls (for value numbering)
% and returns (for accurate gc and execution tracing) do not yet record
% the stack slot holding the succip, so add it to those sets.
code_gen__add_saved_succip(Instructions0,
SuccipSlot, Instructions)
;
MaybeSuccipSlot = no,
Instructions = Instructions0
),
proc_info_get_maybe_proc_table_info(ProcInfo, MaybeTableInfo),
(
( BasicStackLayout = yes
; MaybeTableInfo = yes(table_io_decl_info(_TableIoDeclInfo))
)
->
% Create the procedure layout structure.
RttiProcLabel = rtti__make_rtti_proc_label(ModuleInfo,
PredId, ProcId),
code_info__get_layout_info(CodeInfo, InternalMap),
code_util__make_local_entry_label(ModuleInfo, PredId, ProcId,
no, EntryLabel),
proc_info_eval_method(ProcInfo, EvalMethod),
proc_info_get_initial_instmap(ProcInfo, ModuleInfo, InstMap0),
proc_info_headvars(ProcInfo, HeadVars),
proc_info_varset(ProcInfo, VarSet),
proc_info_argmodes(ProcInfo, ArgModes),
proc_info_vartypes(ProcInfo, VarTypes),
globals__get_trace_suppress(Globals, TraceSuppress),
(
eff_trace_needs_proc_body_reps(PredInfo, ProcInfo,
TraceLevel, TraceSuppress) = yes
->
NeedGoalRep = yes
;
NeedGoalRep = no
),
NeedsAllNames = eff_trace_needs_all_var_names(PredInfo,
ProcInfo, TraceLevel, TraceSuppress),
proc_info_get_maybe_deep_profile_info(ProcInfo,
MaybeHLDSDeepInfo),
(
MaybeHLDSDeepInfo = yes(HLDSDeepInfo),
DeepProfInfo = generate_deep_prof_info(ProcInfo,
HLDSDeepInfo),
MaybeDeepProfInfo = yes(DeepProfInfo)
;
MaybeHLDSDeepInfo = no,
MaybeDeepProfInfo = no
),
EffTraceLevel = eff_trace_level(PredInfo, ProcInfo, TraceLevel),
ProcLayout = proc_layout_info(RttiProcLabel, EntryLabel,
Detism, TotalSlots, MaybeSuccipSlot, EvalMethod,
EffTraceLevel, MaybeTraceCallLabel, MaxTraceReg,
HeadVars, ArgModes, Goal, NeedGoalRep, InstMap0,
TraceSlotInfo, ForceProcId, VarSet, VarTypes,
InternalMap, MaybeTableInfo, NeedsAllNames,
MaybeDeepProfInfo),
global_data_add_new_proc_layout(proc(PredId, ProcId), ProcLayout,
!GlobalData)
;
true
),
code_info__get_closure_layouts(CodeInfo, ClosureLayouts),
global_data_add_new_closure_layouts(ClosureLayouts, !GlobalData),
ProcLabel = make_proc_label(ModuleInfo, PredId, ProcId),
maybe_add_tabling_pointer_var(ModuleInfo, PredId, ProcId, ProcInfo,
ProcLabel, !GlobalData),
Name = pred_info_name(PredInfo),
Arity = pred_info_orig_arity(PredInfo),
code_info__get_label_counter(CodeInfo, LabelCounter),
(
EffTraceIsNone = yes,
MayAlterRtti = may_alter_rtti
;
EffTraceIsNone = no,
MayAlterRtti = must_not_alter_rtti
),
globals__lookup_bool_option(Globals, generate_bytecode, GenBytecode),
(
% XXX: There is a mass of calls above that the bytecode doesn't need;
% work out which is and isn't needed and put % inside the else case
% below.
GenBytecode = yes,
% We don't generate bytecode for unify and compare preds.
% The automatically generated unify and compare predicates
% are correct by construction; for user-defined unify and
% compare predicates, we *assume* their correctness for now
% (perhaps not wisely).
\+ is_unify_or_compare_pred(PredInfo),
% Don't generate bytecode for procs with foreign code
goal_has_foreign(Goal) = no
->
EmptyLabelCounter = counter__init(0),
code_gen__bytecode_stub(ModuleInfo, PredId, ProcId,
BytecodeInstructions),
Proc = c_procedure(Name, Arity, proc(PredId, ProcId),
BytecodeInstructions, ProcLabel, EmptyLabelCounter, MayAlterRtti)
;
Proc = c_procedure(Name, Arity, proc(PredId, ProcId),
Instructions, ProcLabel, LabelCounter, MayAlterRtti)
).
:- pred maybe_set_trace_level(pred_info::in,
module_info::in, module_info::out) is det.
maybe_set_trace_level(PredInfo, !ModuleInfo) :-
module_info_get_globals(!.ModuleInfo, Globals0),
(
PredModule = pred_info_module(PredInfo),
PredName = pred_info_name(PredInfo),
PredArity = pred_info_orig_arity(PredInfo),
no_type_info_builtin(PredModule, PredName, PredArity)
->
% These predicates should never be traced, since they do not obey
% typeinfo_liveness. Since they may be opt_imported into other
% modules, we must switch off the tracing of such preds on a
% pred-by-pred basis.
globals__set_trace_level_none(Globals0, Globals1),
module_info_set_globals(Globals1, !ModuleInfo)
;
pred_info_get_origin(PredInfo, special_pred(_)),
globals__get_trace_level(Globals0, TraceLevel),
UC_TraceLevel = trace_level_for_unify_compare(TraceLevel)
->
globals__set_trace_level(UC_TraceLevel, Globals0, Globals1),
module_info_set_globals(Globals1, !ModuleInfo)
;
true
).
:- func generate_deep_prof_info(proc_info, deep_profile_proc_info)
= proc_layout_proc_static.
generate_deep_prof_info(ProcInfo, HLDSDeepInfo) = DeepProfInfo :-
HLDSDeepInfo ^ deep_layout = MaybeHLDSDeepLayout,
(
MaybeHLDSDeepLayout = yes(HLDSDeepLayout)
;
MaybeHLDSDeepLayout = no,
unexpected(this_file,
"generate_deep_prof_info: no HLDS deep profiling layout info")
),
HLDSDeepLayout = hlds_deep_layout(HLDSProcStatic, HLDSExcpVars),
HLDSExcpVars = hlds_deep_excp_vars(TopCSDVar, MiddleCSDVar,
MaybeOldOutermostVar),
proc_info_stack_slots(ProcInfo, StackSlots),
( map__search(StackSlots, TopCSDVar, TopCSDSlot) ->
TopCSDSlotNum = stack_slot_num(TopCSDSlot),
map__lookup(StackSlots, MiddleCSDVar, MiddleCSDSlot),
MiddleCSDSlotNum = stack_slot_num(MiddleCSDSlot),
(
MaybeOldOutermostVar = yes(OldOutermostVar),
map__lookup(StackSlots, OldOutermostVar, OldOutermostSlot),
OldOutermostSlotNum = stack_slot_num(OldOutermostSlot)
;
MaybeOldOutermostVar = no,
OldOutermostSlotNum = -1
)
;
TopCSDSlotNum = -1,
MiddleCSDSlotNum = -1,
OldOutermostSlotNum = -1
),
DeepExcpSlots = deep_excp_slots(TopCSDSlotNum, MiddleCSDSlotNum,
OldOutermostSlotNum),
DeepProfInfo = proc_layout_proc_static(HLDSProcStatic, DeepExcpSlots).
:- pred maybe_add_tabling_pointer_var(module_info::in,
pred_id::in, proc_id::in, proc_info::in, proc_label::in,
global_data::in, global_data::out) is det.
maybe_add_tabling_pointer_var(ModuleInfo, PredId, ProcId, ProcInfo, ProcLabel,
!GlobalData) :-
proc_info_eval_method(ProcInfo, EvalMethod),
HasTablingPointer = eval_method_has_per_proc_tabling_pointer(EvalMethod),
(
HasTablingPointer = yes,
module_info_get_name(ModuleInfo, ModuleName),
Var = tabling_pointer_var(ModuleName, ProcLabel),
global_data_add_new_proc_var(proc(PredId, ProcId), Var, !GlobalData)
;
HasTablingPointer = no
).
%---------------------------------------------------------------------------%
%---------------------------------------------------------------------------%
% Generate_category_code generates code for an entire procedure.
% Its algorithm has three or four main stages:
%
% - generate code for the body goal
% - generate code for the procedure entry
% - generate code for the procedure exit
% - generate code for the procedure fail (if needed)
%
% The first three tasks are forwarded to other procedures.
% The fourth task, if needed, is done by generate_category_code.
%
% The only caller of generate_category_code, generate_proc_code,
% has set up the code generator state to reflect what the machine
% state will be on entry to the procedure. Ensuring that the
% machine state at exit will conform to the expectation
% of the caller is the job of code_gen__generate_exit.
%
% The reason why we generate the entry code after the body is that
% information such as the total number of stack slots needed,
% which is needed in the procedure entry prologue, cannot be
% conveniently obtained before generating the body, since the
% code generator may allocate temporary variables to hold values
% such as saved heap and trail pointers.
%
% Code_gen__generate_entry cannot depend on the code generator
% state, since when it is invoked this state is not appropriate
% for the procedure entry. Nor can it change the code generator state,
% since that would confuse code_gen__generate_exit.
%
% Generating CALL trace events is done by generate_category_code,
% since only on entry to generate_category_code is the code generator
% state set up right. Generating EXIT trace events is done by
% code_gen__generate_exit. Generating FAIL trace events is done
% by generate_category_code, since this requires modifying how
% we generate code for the body of the procedure (failures must
% now branch to a different place). Since FAIL trace events are
% part of the failure continuation, generate_category_code takes
% care of the failure continuation as well. (Model_det procedures
% of course have no failure continuation. Model_non procedures have
% a failure continuation, but in the absence of tracing this
% continuation needs no code. Only model_semi procedures need code
% for the failure continuation at all times.)
:- pred generate_category_code(code_model::in, hlds_goal::in,
resume_point_info::in, trace_slot_info::in, code_tree::out,
maybe(label)::out, frame_info::out, code_info::in, code_info::out) is det.
generate_category_code(model_det, Goal, ResumePoint, TraceSlotInfo, Code,
MaybeTraceCallLabel, FrameInfo, !CI) :-
% Generate the code for the body of the procedure.
(
code_info__get_globals(!.CI, Globals),
globals__lookup_bool_option(Globals, middle_rec, yes),
middle_rec__match_and_generate(Goal, MiddleRecCode, !CI)
->
Code = MiddleRecCode,
MaybeTraceCallLabel = no,
FrameInfo = frame(0, no, no)
;
Goal = _ - GoalInfo,
goal_info_get_context(GoalInfo, BodyContext),
code_info__get_maybe_trace_info(!.CI, MaybeTraceInfo),
(
MaybeTraceInfo = yes(TraceInfo),
trace__generate_external_event_code(call, TraceInfo,
BodyContext, MaybeCallExternalInfo, !CI),
(
MaybeCallExternalInfo = yes(CallExternalInfo),
CallExternalInfo = external_event_info(TraceCallLabel, _,
TraceCallCode)
;
MaybeCallExternalInfo = no,
unexpected(this_file,
"generate_category_code: call events suppressed")
),
MaybeTraceCallLabel = yes(TraceCallLabel)
;
MaybeTraceInfo = no,
TraceCallCode = empty,
MaybeTraceCallLabel = no
),
code_gen__generate_goal(model_det, Goal, BodyCode, !CI),
code_gen__generate_entry(!.CI, model_det, Goal, ResumePoint,
FrameInfo, EntryCode),
code_gen__generate_exit(model_det, FrameInfo, TraceSlotInfo,
BodyContext, _, ExitCode, !CI),
Code = tree_list([EntryCode, TraceCallCode, BodyCode, ExitCode])
).
generate_category_code(model_semi, Goal, ResumePoint, TraceSlotInfo, Code,
MaybeTraceCallLabel, FrameInfo, !CI) :-
set__singleton_set(FailureLiveRegs, reg(r, 1)),
FailCode = node([
assign(reg(r, 1), const(false)) - "Fail",
livevals(FailureLiveRegs) - "",
goto(succip) - "Return from procedure call"
]),
Goal = _ - GoalInfo,
goal_info_get_context(GoalInfo, BodyContext),
code_info__get_maybe_trace_info(!.CI, MaybeTraceInfo),
(
MaybeTraceInfo = yes(TraceInfo),
trace__generate_external_event_code(call, TraceInfo, BodyContext,
MaybeCallExternalInfo, !CI),
(
MaybeCallExternalInfo = yes(CallExternalInfo),
CallExternalInfo = external_event_info(TraceCallLabel, _,
TraceCallCode)
;
MaybeCallExternalInfo = no,
unexpected(this_file,
"generate_category_code: call events suppressed")
),
MaybeTraceCallLabel = yes(TraceCallLabel),
code_gen__generate_goal(model_semi, Goal, BodyCode, !CI),
code_gen__generate_entry(!.CI, model_semi, Goal, ResumePoint,
FrameInfo, EntryCode),
code_gen__generate_exit(model_semi, FrameInfo, TraceSlotInfo,
BodyContext, RestoreDeallocCode, ExitCode, !CI),
code_info__generate_resume_point(ResumePoint, ResumeCode, !CI),
code_info__resume_point_vars(ResumePoint, ResumeVarList),
set__list_to_set(ResumeVarList, ResumeVars),
code_info__set_forward_live_vars(ResumeVars, !CI),
% XXX A context that gives the end of the procedure
% definition would be better than BodyContext.
trace__generate_external_event_code(fail, TraceInfo, BodyContext,
MaybeFailExternalInfo, !CI),
(
MaybeFailExternalInfo = yes(FailExternalInfo),
FailExternalInfo = external_event_info(_, _, TraceFailCode)
;
MaybeFailExternalInfo = no,
TraceFailCode = empty
),
Code = tree_list([EntryCode, TraceCallCode, BodyCode, ExitCode,
ResumeCode, TraceFailCode, RestoreDeallocCode, FailCode])
;
MaybeTraceInfo = no,
MaybeTraceCallLabel = no,
code_gen__generate_goal(model_semi, Goal, BodyCode, !CI),
code_gen__generate_entry(!.CI, model_semi, Goal, ResumePoint,
FrameInfo, EntryCode),
code_gen__generate_exit(model_semi, FrameInfo, TraceSlotInfo,
BodyContext, RestoreDeallocCode, ExitCode, !CI),
code_info__generate_resume_point(ResumePoint, ResumeCode, !CI),
Code = tree_list([EntryCode, BodyCode, ExitCode,
ResumeCode, RestoreDeallocCode, FailCode])
).
generate_category_code(model_non, Goal, ResumePoint, TraceSlotInfo, Code,
MaybeTraceCallLabel, FrameInfo, !CI) :-
code_info__get_maybe_trace_info(!.CI, MaybeTraceInfo),
Goal = _ - GoalInfo,
goal_info_get_context(GoalInfo, BodyContext),
(
MaybeTraceInfo = yes(TraceInfo),
trace__generate_external_event_code(call, TraceInfo, BodyContext,
MaybeCallExternalInfo, !CI),
(
MaybeCallExternalInfo = yes(CallExternalInfo),
CallExternalInfo = external_event_info(TraceCallLabel, _,
TraceCallCode)
;
MaybeCallExternalInfo = no,
unexpected(this_file,
"generate_category_code: call events suppressed")
),
MaybeTraceCallLabel = yes(TraceCallLabel),
code_gen__generate_goal(model_non, Goal, BodyCode, !CI),
code_gen__generate_entry(!.CI, model_non, Goal, ResumePoint,
FrameInfo, EntryCode),
code_gen__generate_exit(model_non, FrameInfo, TraceSlotInfo,
BodyContext, _, ExitCode, !CI),
code_info__generate_resume_point(ResumePoint, ResumeCode, !CI),
code_info__resume_point_vars(ResumePoint, ResumeVarList),
set__list_to_set(ResumeVarList, ResumeVars),
code_info__set_forward_live_vars(ResumeVars, !CI),
% XXX A context that gives the end of the procedure
% definition would be better than BodyContext.
trace__generate_external_event_code(fail, TraceInfo, BodyContext,
MaybeFailExternalInfo, !CI),
(
MaybeFailExternalInfo = yes(FailExternalInfo),
FailExternalInfo = external_event_info(_, _, TraceFailCode)
;
MaybeFailExternalInfo = no,
TraceFailCode = empty
),
( TraceSlotInfo ^ slot_trail = yes(_) ->
MaybeFromFull = TraceSlotInfo ^ slot_from_full,
(
MaybeFromFull = yes(FromFullSlot),
% Generate code which discards the ticket only if it was
% allocated, i.e. only if MR_trace_from_full was true on entry.
FromFullSlotLval =
llds__stack_slot_num_to_lval(model_non, FromFullSlot),
code_info__get_next_label(SkipLabel, !CI),
DiscardTraceTicketCode = node([
if_val(unop(not, lval(FromFullSlotLval)),
label(SkipLabel)) - "",
discard_ticket - "discard retry ticket",
label(SkipLabel) - ""
])
;
MaybeFromFull = no,
DiscardTraceTicketCode = node([
discard_ticket - "discard retry ticket"
])
)
;
DiscardTraceTicketCode = empty
),
FailCode = node([
goto(do_fail) - "fail after fail trace port"
]),
Code = tree_list([EntryCode, TraceCallCode, BodyCode, ExitCode,
ResumeCode, TraceFailCode, DiscardTraceTicketCode, FailCode])
;
MaybeTraceInfo = no,
MaybeTraceCallLabel = no,
code_gen__generate_goal(model_non, Goal, BodyCode, !CI),
code_gen__generate_entry(!.CI, model_non, Goal, ResumePoint,
FrameInfo, EntryCode),
code_gen__generate_exit(model_non, FrameInfo, TraceSlotInfo,
BodyContext, _, ExitCode, !CI),
Code = tree_list([EntryCode, BodyCode, ExitCode])
).
%---------------------------------------------------------------------------%
% Generate the prologue for a procedure.
%
% The prologue will contain
%
% a comment to mark prologue start
% a comment explaining the stack layout
% the procedure entry label
% code to allocate a stack frame
% code to fill in some special slots in the stack frame
% a comment to mark prologue end
%
% At the moment the only special slots are the succip slot, and
% the slots holding the call number and call depth for tracing.
%
% Not all frames will have all these components. For example, the code
% to allocate a stack frame will be missing if the procedure doesn't
% need a stack frame, and if the procedure is nondet, then the code
% to fill in the succip slot is subsumed by the mkframe.
:- pred code_gen__generate_entry(code_info::in, code_model::in, hlds_goal::in,
resume_point_info::in, frame_info::out, code_tree::out) is det.
code_gen__generate_entry(CI, CodeModel, Goal, OutsideResumePoint, FrameInfo,
EntryCode) :-
code_info__get_stack_slots(CI, StackSlots),
code_info__get_varset(CI, VarSet),
SlotsComment = explain_stack_slots(StackSlots, VarSet),
StartComment = node([
comment("Start of procedure prologue") - "",
comment(SlotsComment) - ""
]),
code_info__get_total_stackslot_count(CI, MainSlots),
code_info__get_pred_id(CI, PredId),
code_info__get_proc_id(CI, ProcId),
code_info__get_module_info(CI, ModuleInfo),
code_util__make_local_entry_label(ModuleInfo, PredId, ProcId, no, Entry),
LabelCode = node([
label(Entry) - "Procedure entry point"
]),
code_info__get_succip_used(CI, Used),
(
% Do we need to save the succip across calls?
Used = yes,
% Do we need to use a general slot for storing succip?
CodeModel \= model_non
->
SuccipSlot = MainSlots + 1,
SaveSuccipCode = node([
assign(stackvar(SuccipSlot), lval(succip)) - "Save the success ip"
]),
TotalSlots = SuccipSlot,
MaybeSuccipSlot = yes(SuccipSlot)
;
SaveSuccipCode = empty,
TotalSlots = MainSlots,
MaybeSuccipSlot = no
),
code_info__get_maybe_trace_info(CI, MaybeTraceInfo),
(
MaybeTraceInfo = yes(TraceInfo),
trace__generate_slot_fill_code(CI, TraceInfo, TraceFillCode)
;
MaybeTraceInfo = no,
TraceFillCode = empty
),
module_info_pred_info(ModuleInfo, PredId, PredInfo),
ModuleName = pred_info_module(PredInfo),
PredName = pred_info_name(PredInfo),
Arity = pred_info_orig_arity(PredInfo),
PushMsg = code_gen__push_msg(ModuleInfo, PredId, ProcId),
( CodeModel = model_non ->
code_info__resume_point_stack_addr(OutsideResumePoint,
OutsideResumeAddress),
(
Goal = foreign_proc(_, _, _, _, _, PragmaCode) - _,
PragmaCode = nondet(Fields, FieldsContext,
_, _, _, _, _, _, _)
->
pragma_c_gen__struct_name(ModuleName, PredName, Arity, ProcId,
StructName),
Struct = pragma_c_struct(StructName, Fields, FieldsContext),
string__format("#define\tMR_ORDINARY_SLOTS\t%d\n",
[i(TotalSlots)], DefineStr),
DefineComponents = [pragma_c_raw_code(DefineStr,
cannot_branch_away, live_lvals_info(set__init))],
NondetFrameInfo = ordinary_frame(PushMsg, TotalSlots, yes(Struct)),
AllocCode = node([
mkframe(NondetFrameInfo, yes(OutsideResumeAddress))
- "Allocate stack frame",
pragma_c([], DefineComponents, will_not_call_mercury,
no, no, no, no, no, no) - ""
]),
NondetPragma = yes
;
NondetFrameInfo = ordinary_frame(PushMsg, TotalSlots, no),
AllocCode = node([
mkframe(NondetFrameInfo, yes(OutsideResumeAddress))
- "Allocate stack frame"
]),
NondetPragma = no
)
; TotalSlots > 0 ->
AllocCode = node([
incr_sp(TotalSlots, PushMsg) - "Allocate stack frame"
]),
NondetPragma = no
;
AllocCode = empty,
NondetPragma = no
),
FrameInfo = frame(TotalSlots, MaybeSuccipSlot, NondetPragma),
EndComment = node([
comment("End of procedure prologue") - ""
]),
EntryCode = tree_list([StartComment, LabelCode, AllocCode,
SaveSuccipCode, TraceFillCode, EndComment]).
%---------------------------------------------------------------------------%
% Generate the success epilogue for a procedure.
%
% The success epilogue will contain
%
% a comment to mark epilogue start
% code to place the output arguments where their caller expects
% code to restore registers from some special slots
% code to deallocate the stack frame
% code to set r1 to MR_TRUE (for semidet procedures only)
% a jump back to the caller, including livevals information
% a comment to mark epilogue end
%
% The parts of this that restore registers and deallocate the stack
% frame are also part of the failure epilog, which is handled by
% our caller; this is why we return RestoreDeallocCode.
%
% At the moment the only special slots are the succip slot, and
% the tracing slots (holding the call sequence number, call event
% number, call depth, from-full indication, and trail state).
%
% Not all frames will have all these components. For example, for
% nondet procedures we don't deallocate the stack frame before
% success.
%
% Epilogues for procedures defined by nondet pragma C codes do not
% follow the rules above. For such procedures, the normal functions
% of the epilogue are handled when traversing the pragma C code goal;
% we need only #undef a macro defined by the procedure prologue.
:- pred code_gen__generate_exit(code_model::in, frame_info::in,
trace_slot_info::in, prog_context::in, code_tree::out, code_tree::out,
code_info::in, code_info::out) is det.
code_gen__generate_exit(CodeModel, FrameInfo, TraceSlotInfo, BodyContext,
RestoreDeallocCode, ExitCode, !CI) :-
StartComment = node([
comment("Start of procedure epilogue") - ""
]),
EndComment = node([
comment("End of procedure epilogue") - ""
]),
FrameInfo = frame(TotalSlots, MaybeSuccipSlot, NondetPragma),
( NondetPragma = yes ->
UndefStr = "#undef\tMR_ORDINARY_SLOTS\n",
UndefComponents = [pragma_c_raw_code(UndefStr, cannot_branch_away,
live_lvals_info(set__init))],
UndefCode = node([
pragma_c([], UndefComponents, will_not_call_mercury,
no, no, no, no, no, no) - ""
]),
RestoreDeallocCode = empty, % always empty for nondet code
ExitCode = tree_list([StartComment, UndefCode, EndComment])
;
code_info__get_instmap(!.CI, Instmap),
ArgModes = code_info__get_arginfo(!.CI),
HeadVars = code_info__get_headvars(!.CI),
assoc_list__from_corresponding_lists(HeadVars, ArgModes, Args),
( instmap__is_unreachable(Instmap) ->
OutLvals = set__init,
FlushCode = empty
;
code_info__setup_return(Args, OutLvals, FlushCode, !CI)
),
(
MaybeSuccipSlot = yes(SuccipSlot),
RestoreSuccipCode = node([
assign(succip, lval(stackvar(SuccipSlot))) -
"restore the success ip"
])
;
MaybeSuccipSlot = no,
RestoreSuccipCode = empty
),
(
( TotalSlots = 0
; CodeModel = model_non
)
->
DeallocCode = empty
;
DeallocCode = node([
decr_sp(TotalSlots) - "Deallocate stack frame"
])
),
(
TraceSlotInfo ^ slot_trail = yes(_),
CodeModel \= model_non
->
MaybeFromFull = TraceSlotInfo ^ slot_from_full,
(
MaybeFromFull = yes(FromFullSlot),
% Generate code which prunes the ticket only if it was
% allocated, i.e. only if MR_trace_from_full was true on entry.
%
% Note that to avoid duplicating label names, we need to
% generate two different copies of this with different labels;
% this is needed for semidet code, which will get one copy
% in the success epilogue and one copy in the failure epilogue.
%
FromFullSlotLval =
llds__stack_slot_num_to_lval(CodeModel, FromFullSlot),
code_info__get_next_label(SkipLabel, !CI),
code_info__get_next_label(SkipLabelCopy, !CI),
PruneTraceTicketCode = node([
if_val(unop(not, lval(FromFullSlotLval)),
label(SkipLabel)) - "",
prune_ticket - "prune retry ticket",
label(SkipLabel) - ""
]),
PruneTraceTicketCodeCopy = node([
if_val(unop(not, lval(FromFullSlotLval)),
label(SkipLabelCopy)) - "",
prune_ticket - "prune retry ticket",
label(SkipLabelCopy) - ""
])
;
MaybeFromFull = no,
PruneTraceTicketCode = node([
prune_ticket - "prune retry ticket"
]),
PruneTraceTicketCodeCopy = PruneTraceTicketCode
)
;
PruneTraceTicketCode = empty,
PruneTraceTicketCodeCopy = empty
),
RestoreDeallocCode = tree_list([RestoreSuccipCode,
PruneTraceTicketCode, DeallocCode]),
RestoreDeallocCodeCopy = tree_list([RestoreSuccipCode,
PruneTraceTicketCodeCopy, DeallocCode]),
code_info__get_maybe_trace_info(!.CI, MaybeTraceInfo),
(
MaybeTraceInfo = yes(TraceInfo),
% XXX A context that gives the end of the procedure definition
% would be better than CallContext.
trace__generate_external_event_code(exit, TraceInfo, BodyContext,
MaybeExitExternalInfo, !CI),
(
MaybeExitExternalInfo = yes(ExitExternalInfo),
ExitExternalInfo = external_event_info(_, TypeInfoDatas,
TraceExitCode)
;
MaybeExitExternalInfo = no,
TypeInfoDatas = map__init,
TraceExitCode = empty
),
map__values(TypeInfoDatas, TypeInfoLocnSets),
FindBaseLvals = (pred(Lval::out) is nondet :-
list__member(LocnSet, TypeInfoLocnSets),
set__member(Locn, LocnSet),
(
Locn = direct(Lval)
;
Locn = indirect(Lval, _)
)
),
solutions(FindBaseLvals, TypeInfoLvals),
set__insert_list(OutLvals, TypeInfoLvals, LiveLvals)
;
MaybeTraceInfo = no,
TraceExitCode = empty,
LiveLvals = OutLvals
),
(
CodeModel = model_det,
SuccessCode = node([
livevals(LiveLvals) - "",
goto(succip) - "Return from procedure call"
]),
AllSuccessCode = tree_list([TraceExitCode, RestoreDeallocCodeCopy,
SuccessCode])
;
CodeModel = model_semi,
set__insert(LiveLvals, reg(r, 1), SuccessLiveRegs),
SuccessCode = node([
assign(reg(r, 1), const(true)) - "Succeed",
livevals(SuccessLiveRegs) - "",
goto(succip) - "Return from procedure call"
]),
AllSuccessCode = tree_list([TraceExitCode, RestoreDeallocCodeCopy,
SuccessCode])
;
CodeModel = model_non,
(
MaybeTraceInfo = yes(TraceInfo2),
trace__maybe_setup_redo_event(TraceInfo2, SetupRedoCode)
;
MaybeTraceInfo = no,
SetupRedoCode = empty
),
SuccessCode = node([
livevals(LiveLvals) - "",
goto(do_succeed(no)) - "Return from procedure call"
]),
AllSuccessCode = tree_list([SetupRedoCode,
TraceExitCode, SuccessCode])
),
ExitCode = tree_list([StartComment, FlushCode, AllSuccessCode,
EndComment])
).
%---------------------------------------------------------------------------%
code_gen__generate_goal(ContextModel, Goal - GoalInfo, Code, !CI) :-
% Generate a goal. This predicate arranges for the necessary updates of
% the generic data structures before and after the actual code generation,
% which is delegated to goal-specific predicates.
% Make any changes to liveness before Goal
( goal_is_atomic(Goal) ->
IsAtomic = yes
;
IsAtomic = no
),
code_info__pre_goal_update(GoalInfo, IsAtomic, !CI),
code_info__get_instmap(!.CI, Instmap),
( instmap__is_reachable(Instmap) ->
goal_info_get_code_model(GoalInfo, CodeModel),
% Sanity check: code of some code models should occur
% only in limited contexts.
(
CodeModel = model_det
;
CodeModel = model_semi,
( ContextModel \= model_det ->
true
;
error("semidet model in det context")
)
;
CodeModel = model_non,
( ContextModel = model_non ->
true
;
error("nondet model in det/semidet context")
)
),
code_gen__generate_goal_2(Goal, GoalInfo, CodeModel, GoalCode, !CI),
goal_info_get_features(GoalInfo, Features),
code_info__get_proc_info(!.CI, ProcInfo),
% If the predicate's evaluation method is memo, loopcheck or minimal
% model, the goal generated the variable that represents the call table
% tip, *and* tracing is enabled, then we save this variable to its
% stack slot. This is necessary to enable retries across this procedure
% to reset the call table entry to uninitialized, effectively removing
% the call table entry.
%
% If tracing is not enabled, then CallTableVar isn't guaranteed
% to have a stack slot.
(
set__member(call_table_gen, Features),
code_info__get_proc_info(!.CI, ProcInfo),
proc_info_get_call_table_tip(ProcInfo, MaybeCallTableVar),
MaybeCallTableVar = yes(CallTableVar),
code_info__get_maybe_trace_info(!.CI, yes(_))
->
code_info__save_variables_on_stack([CallTableVar], TipSaveCode,
!CI),
CodeUptoTip = tree(GoalCode, TipSaveCode)
;
CodeUptoTip = GoalCode
),
% After the goal that generates the variables needed at the exception
% port, on which deep_profiling.m puts the save_deep_excp_vars feature,
% save those variables in their stack slots. The procedure layout
% structure gives the identity of their slots, and exception.m
% expects to find the variables in their stack slots.
%
% These variables are computed by the call port code and are needed
% by the exit and fail port codes, so their lifetime is the entire
% procedure invocation. If the procedure makes any calls other than
% the ones inserted by deep profiling, then all the variables will have
% stack slots, and we save them all on the stack. If the procedure
% doesn't make any such calls, then the variables won't have stack
% slots, but they won't *need* stack slots either, since there is no
% way for such a leaf procedure to throw an exception. (Throwing
% requires calling exception__throw, directly or indirectly.)
(
set__member(save_deep_excp_vars, Features)
->
DeepSaveVars = compute_deep_save_excp_vars(ProcInfo),
code_info__save_variables_on_stack(DeepSaveVars, DeepSaveCode,
!CI),
Code = tree(CodeUptoTip, DeepSaveCode)
;
Code = CodeUptoTip
),
% Make live any variables which subsequent goals will expect to be
% live, but were not generated.
code_info__set_instmap(Instmap, !CI),
code_info__post_goal_update(GoalInfo, !CI)
;
Code = empty
).
:- func compute_deep_save_excp_vars(proc_info) = list(prog_var).
compute_deep_save_excp_vars(ProcInfo) = DeepSaveVars :-
proc_info_get_maybe_deep_profile_info(ProcInfo, MaybeDeepProfInfo),
(
MaybeDeepProfInfo = yes(DeepProfInfo),
MaybeDeepLayout = DeepProfInfo ^ deep_layout,
MaybeDeepLayout = yes(DeepLayout)
->
ExcpVars = DeepLayout ^ deep_layout_excp,
ExcpVars = hlds_deep_excp_vars(TopCSDVar, MiddleCSDVar,
MaybeOldOutermostVar),
proc_info_stack_slots(ProcInfo, StackSlots),
( map__search(StackSlots, TopCSDVar, _) ->
% If one of these variables has a stack slot, the others must
% have one too.
(
MaybeOldOutermostVar = yes(OldOutermostVar),
DeepSaveVars = [TopCSDVar, MiddleCSDVar, OldOutermostVar]
;
MaybeOldOutermostVar = no,
DeepSaveVars = [TopCSDVar, MiddleCSDVar]
)
;
DeepSaveVars = []
)
;
unexpected(this_file,
"compute_deep_save_excp_vars: inconsistent proc_info")
).
%---------------------------------------------------------------------------%
:- pred code_gen__generate_goal_2(hlds_goal_expr::in, hlds_goal_info::in,
code_model::in, code_tree::out, code_info::in, code_info::out) is det.
code_gen__generate_goal_2(unify(_, _, _, Uni, _), GoalInfo, CodeModel, Code,
!CI) :-
unify_gen__generate_unification(CodeModel, Uni, GoalInfo, Code, !CI).
code_gen__generate_goal_2(conj(Goals), _GoalInfo, CodeModel, Code, !CI) :-
code_gen__generate_goals(Goals, CodeModel, Code, !CI).
code_gen__generate_goal_2(par_conj(Goals), GoalInfo, CodeModel, Code, !CI) :-
par_conj_gen__generate_par_conj(Goals, GoalInfo, CodeModel, Code, !CI).
code_gen__generate_goal_2(disj(Goals), GoalInfo, CodeModel, Code, !CI) :-
disj_gen__generate_disj(CodeModel, Goals, GoalInfo, Code, !CI).
code_gen__generate_goal_2(not(Goal), GoalInfo, CodeModel, Code, !CI) :-
ite_gen__generate_negation(CodeModel, Goal, GoalInfo, Code, !CI).
code_gen__generate_goal_2(if_then_else(_Vars, Cond, Then, Else),
GoalInfo, CodeModel, Code, !CI) :-
ite_gen__generate_ite(CodeModel, Cond, Then, Else, GoalInfo, Code, !CI).
code_gen__generate_goal_2(switch(Var, CanFail, CaseList),
GoalInfo, CodeModel, Code, !CI) :-
switch_gen__generate_switch(CodeModel, Var, CanFail, CaseList,
GoalInfo, Code, !CI).
code_gen__generate_goal_2(scope(_, Goal), _GoalInfo, CodeModel, Code, !CI) :-
commit_gen__generate_commit(CodeModel, Goal, Code, !CI).
code_gen__generate_goal_2(generic_call(GenericCall, Args, Modes, Det),
GoalInfo, CodeModel, Code, !CI) :-
call_gen__generate_generic_call(CodeModel, GenericCall, Args,
Modes, Det, GoalInfo, Code, !CI).
code_gen__generate_goal_2(call(PredId, ProcId, Args, BuiltinState, _,_),
GoalInfo, CodeModel, Code, !CI) :-
( BuiltinState = not_builtin ->
call_gen__generate_call(CodeModel, PredId, ProcId, Args,
GoalInfo, Code, !CI)
;
call_gen__generate_builtin(CodeModel, PredId, ProcId, Args,
Code, !CI)
).
code_gen__generate_goal_2(foreign_proc(Attributes, PredId, ProcId,
Args, ExtraArgs, PragmaCode),
GoalInfo, CodeModel, Code, !CI) :-
( c = foreign_language(Attributes) ->
pragma_c_gen__generate_pragma_c_code(CodeModel, Attributes,
PredId, ProcId, Args, ExtraArgs, GoalInfo, PragmaCode, Code, !CI)
;
unexpected(this_file,
"code_gen__generate_goal_2: foreign code other than C unexpected")
).
code_gen__generate_goal_2(shorthand(_), _, _, _, !CI) :-
% These should have been expanded out by now.
unexpected(this_file, "code_gen__generate_goal_2: unexpected shorthand").
%---------------------------------------------------------------------------%
% Generate a conjoined series of goals. Note of course, that with a
% conjunction, state information flows directly from one conjunct
% to the next.
%
:- pred code_gen__generate_goals(hlds_goals::in, code_model::in,
code_tree::out, code_info::in, code_info::out) is det.
code_gen__generate_goals([], _, empty, !CI).
code_gen__generate_goals([Goal | Goals], CodeModel, Code, !CI) :-
code_gen__generate_goal(CodeModel, Goal, Code1, !CI),
code_info__get_instmap(!.CI, Instmap),
( instmap__is_unreachable(Instmap) ->
Code = Code1
;
code_gen__generate_goals(Goals, CodeModel, Code2, !CI),
Code = tree(Code1, Code2)
).
%---------------------------------------------------------------------------%
% Add the succip to the livevals before and after calls. Traverses the list
% of instructions looking for livevals and calls, adding succip in the
% stackvar number given as an argument.
%
:- pred code_gen__add_saved_succip(list(instruction)::in, int::in,
list(instruction)::out) is det.
code_gen__add_saved_succip([], _StackLoc, []).
code_gen__add_saved_succip([Instrn0 - Comment | Instrns0 ], StackLoc,
[Instrn - Comment | Instrns]) :-
(
Instrn0 = livevals(LiveVals0),
Instrns0 \= [goto(succip) - _ | _]
% XXX We should also test for tailcalls
% once we start generating them directly.
->
set__insert(LiveVals0, stackvar(StackLoc), LiveVals1),
Instrn = livevals(LiveVals1)
;
Instrn0 = call(Target, ReturnLabel, LiveVals0, Context, GP, CM)
->
map__init(Empty),
LiveVals = [live_lvalue(direct(stackvar(StackLoc)),
succip, Empty) | LiveVals0],
Instrn = call(Target, ReturnLabel, LiveVals, Context, GP, CM)
;
Instrn = Instrn0
),
code_gen__add_saved_succip(Instrns0, StackLoc, Instrns).
%---------------------------------------------------------------------------%
:- pred code_gen__bytecode_stub(module_info::in, pred_id::in, proc_id::in,
list(instruction)::out) is det.
code_gen__bytecode_stub(ModuleInfo, PredId, ProcId, BytecodeInstructions) :-
module_info_pred_info(ModuleInfo, PredId, PredInfo),
ModuleSymName = pred_info_module(PredInfo),
sym_name_to_string(ModuleSymName, "__", ModuleName),
code_util__make_local_entry_label(ModuleInfo, PredId, ProcId, no, Entry),
PredName = pred_info_name(PredInfo),
proc_id_to_int(ProcId, ProcNum),
string__int_to_string(ProcNum, ProcStr),
Arity = pred_info_orig_arity(PredInfo),
int_to_string(Arity, ArityStr),
PredOrFunc = pred_info_is_pred_or_func(PredInfo),
CallStructName = "bytecode_call_info",
append_list([
"\t\tstatic MB_Call ", CallStructName, " = {\n",
"\t\t\t(MB_Word)NULL,\n",
"\t\t\t""", ModuleName, """,\n",
"\t\t\t""", PredName, """,\n",
"\t\t\t", ProcStr, ",\n",
"\t\t\t", ArityStr, ",\n",
"\t\t\t", (PredOrFunc = function -> "MR_TRUE" ; "MR_FALSE"), "\n",
"\t\t};\n"
], CallStruct),
append_list([
"\t\tMB_Native_Addr return_addr;\n",
"\t\tMR_save_registers();\n",
"\t\treturn_addr = MB_bytecode_call_entry(", "&",CallStructName,");\n",
"\t\tMR_restore_registers();\n",
"\t\tMR_GOTO(return_addr);\n"
], BytecodeCall),
BytecodeInstructionsComponents = [
pragma_c_raw_code("\t{\n", cannot_branch_away,
live_lvals_info(set__init)),
pragma_c_raw_code(CallStruct, cannot_branch_away,
live_lvals_info(set__init)),
pragma_c_raw_code(BytecodeCall, cannot_branch_away,
no_live_lvals_info),
pragma_c_raw_code("\t}\n", cannot_branch_away,
live_lvals_info(set__init))
],
BytecodeInstructions = [
label(Entry) - "Procedure entry point",
pragma_c([], BytecodeInstructionsComponents, may_call_mercury,
no, no, no, no, no, no) - "Entry stub"
].
%---------------------------------------------------------------------------%
:- type type_giving_arg ---> last_arg ; last_but_one_arg.
code_gen__push_msg(ModuleInfo, PredId, ProcId) = PushMsg :-
module_info_pred_info(ModuleInfo, PredId, PredInfo),
PredOrFunc = pred_info_is_pred_or_func(PredInfo),
ModuleName = pred_info_module(PredInfo),
PredName = pred_info_name(PredInfo),
Arity = pred_info_orig_arity(PredInfo),
pred_info_get_origin(PredInfo, Origin),
( Origin = special_pred(SpecialId - TypeCtor) ->
code_gen__find_arg_type_ctor_name(TypeCtor, TypeName),
SpecialPredName = get_special_pred_id_generic_name(SpecialId),
FullPredName = SpecialPredName ++ "_for_" ++ TypeName
;
FullPredName = PredName
),
% XXX if ModuleNameString ends with [0-9] and/or FullPredName starts with
% [0-9] then ideally we should use "'.'" rather than just ".".
%
PushMsg = pred_or_func_to_str(PredOrFunc) ++ " " ++
sym_name_to_string(ModuleName) ++ "." ++
FullPredName ++ "/" ++ int_to_string(Arity) ++ "-" ++
int_to_string(proc_id_to_int(ProcId)).
:- pred code_gen__find_arg_type_ctor_name((type_ctor)::in, string::out) is det.
code_gen__find_arg_type_ctor_name(TypeCtor, TypeName) :-
TypeCtor = TypeCtorSymName - TypeCtorArity,
mdbcomp__prim_data__sym_name_to_string(TypeCtorSymName, TypeCtorName),
string__int_to_string(TypeCtorArity, ArityStr),
string__append_list([TypeCtorName, "_", ArityStr], TypeName).
%---------------------------------------------------------------------------%
:- func this_file = string.
this_file = "code_gen.m".
%---------------------------------------------------------------------------%