Commit Graph

227 Commits

Author SHA1 Message Date
Zoltan Somogyi
f7355f708b Move var_db and var_{name,type}_source to var_db.m.
In the process, restrict the use of these types to just those modules
that need to provide services both other modules that use var_tables,
and modules that do not. The latter are modules that either can,
or always do, execute before var_tables are set up.

In some cases, code that previously operated on e.g. var_name_sources
had all its callers converted to use var_tables. In those cases, replace
the use of var_name_sources with var_tables directly.

In other cases, code that previously operated on e.g. var_name_sources
still has some callers that use varsets. In those cases,

- provide versions using var_tables if most callers use var_tables,
  renaming predicates/functions to make this the version seem the default,

- leave the operation to work on var_name_sources if some its callers
  also have only var_name_sources,

- if there are no such callers, keep just the two versions operating
  on varsets and var_tables respectively.

compiler/var_db.m:
compiler/var_table.m:
    Move the part of var_table.m that contains the definitions
    of the above three types, and the operations on them, to the
    new module var_db.m. Only 25 modules currently need var_db.m,
    compared to 176 for var_table.m.

compiler/parse_tree.m:
compiler/notes/compiler_design.html:
    Add and document the new module.

compiler/parse_tree_out_term.m:
    Add a "_vs" suffix to the names of operations that print variables
    or terms using varsets, and reuse their old names for versions
    that use var_table arguments. For the operations that need var_name_source
    versions, make it just select between the varset and var_table versions.

compiler/hlds_out_goal.m:
compiler/instmap.m:
compiler/hlds_out_mode.m:
compiler/hlds_out_util.m:
compiler/hlds_pred.m:
compiler/pd_info.m:
    Change some predicates that used to operate on var_{name,type}_sources
    to operate on var_tables.

    In hlds_out_mode.m, delete some unused predicates, and stop exporting
    a predicate whose only caller is local.

compiler/*.m:
    Conform to the changes above.
2022-08-19 10:44:39 +10:00
Zoltan Somogyi
2a1c2bb88a Make quantification using var_tables the default.
compiler/quantification.m:
    Add a "_vs" suffix to the names of predicates that use varsets, and
    delete the "_vt" suffix from the names of predicates that use var_tables.

    Keep private a predicate that now has no callers outside this module.

    Shorten the names of some function symbols.

compiler/recompute_instmap_deltas.m:
    Shorten the names of some function symbols.

compiler/equiv_type_hlds.m:
    Give a predicate a more meaningful name.

compiler/*.m:
    Conform to the change above.
2022-08-18 20:36:18 +10:00
Zoltan Somogyi
d787ee9355 Store var_tables in proc_infos.
This fixes the performance problem reported in Mantis bug #562.

compiler/hlds_pred.m:
    Instead of storing a varset and a vartypes in each proc_info,
    store just a var_table. Update the predicates that create
    or clone procedures accordingly.

    Where we had operations on proc_infos that had two versions,
    one operating on a varset/vartypes pair and one operating on var_table,
    keep only the latter, with the (shorter) name of the former.

    Delete the arity argument of proc_info_init, because the only
    valid value of that argument is the length of the list of the
    argument types. (In other words, this arg has been redundant
    all along.)

    Change the operations that create new variables in a procedure
    to get the caller to specify the (base) name of the new variable
    up front.

    Delete the unused predicate proc_info_ensure_unique_names.

compiler/type_util.m:
    Due to the change above, we now construct var_tables during the
    construction of the HLDS. The code that does that needs to fill in
    the field that says whether the type of each variable in the table
    is a dummy type or not. However, at this time, the pass that decides
    type representations has not been run yet. The code of is_type_a_dummy
    used to throw an exception in such situations.

    Change this so that in such situations, is_type_a_dummy returns
    a placeholder, not-guaranteed-to-be-correct value. Document why
    this is ok.

compiler/post_typecheck.m:
    Replace the placeholder values in vte_is_dummy fields in all
    the entries in the var_tables in all (valid) predicates with valid data.
    (If there are any invalid predicates, the compilation will fail anyway.)
    The clause_to_proc pass will copy these updated var_tables
    to be the initial var_tables in procedures.

compiler/make_goal.m:
    Change the operations that create new variables in a procedure
    to get the caller to specify the (base) name of the new variable
    up front. This is simpler than the old method, which created new
    variables without a name, and had the caller give them a name as
    a separate operation. And since var_tables need this info,
    get the caller to also specify whether the type is a dummy,
    if the type is not a builtin type which is known not to be a dummy.

compiler/var_table.m:
    Document the times when the types and is_dummy fields in var_table
    entries become meaningful.

    Fix a potential bug: when performing type substitutions in
    var_table entries, updating a variable's type may change whether
    that variable is a dummy or not, so recompute that info.
    It is quite possible that we *never* replace a nondummy type
    with a dummy type or vice versa, but in the absence of a convincing
    correctness argument for that proposition, better safe than sorry.

    Export the previously-private predicate transform_var_table
    to post_typecheck.

    Add code to implement the unused predicate deleted from hlds_pred.m:
    at the time I wrote it, I haven't yet realised that it was unused.
    The code I wrote here is therefore unused as well, so it is commented out.
    I did not delete it, because it may be useful later on.

compiler/direct_arg_in_out.m:
    Don't make and split var_tables, since it is no longer needed.

compiler/accumulator.m:
compiler/add_class.m:
compiler/add_clause.m:
compiler/add_heap_ops.m:
compiler/add_pred.m:
compiler/add_special_pred.m:
compiler/add_trail_ops.m:
compiler/arg_info.m:
compiler/build_mode_constraints.m:
compiler/bytecode_gen.m:
compiler/check_typeclass.m:
compiler/clause_to_proc.m:
compiler/closure_analysis.m:
compiler/code_gen.m:
compiler/code_loc_dep.m:
compiler/complexity.m:
compiler/continuation_info.m:
compiler/cse_detection.m:
compiler/ctgc.livedata.m:
compiler/deep_profiling.m:
compiler/default_func_mode.m:
compiler/deforest.m:
compiler/delay_construct.m:
compiler/delay_partial_inst.m:
compiler/dep_par_conj.m:
compiler/det_analysis.m:
compiler/det_report.m:
compiler/distance_granularity.m:
compiler/equiv_type_hlds.m:
compiler/exception_analysis.m:
compiler/float_regs.m:
compiler/follow_code.m:
compiler/goal_mode.m:
compiler/goal_path.m:
compiler/higher_order.m:
compiler/hlds_out_pred.m:
compiler/hlds_rtti.m:
compiler/hlds_statistics.m:
compiler/inlining.m:
compiler/intermod.m:
compiler/intermod_analysis.m:
compiler/introduce_exists_casts.m:
compiler/introduce_parallelism.m:
compiler/lambda.m:
compiler/lco.m:
compiler/live_vars.m:
compiler/liveness.m:
compiler/loop_inv.m:
compiler/mark_tail_calls.m:
compiler/ml_accurate_gc.m:
compiler/ml_args_util.m:
compiler/ml_closure_gen.m:
compiler/ml_gen_info.m:
compiler/ml_proc_gen.m:
compiler/mode_errors.m:
compiler/mode_info.m:
compiler/modecheck_goal.m:
compiler/par_loop_control.m:
compiler/pd_debug.m:
compiler/pd_info.m:
compiler/pd_util.m:
compiler/polymorphism_info.m:
compiler/post_typecheck.m:
compiler/proc_gen.m:
compiler/proc_requests.m:
compiler/purity.m:
compiler/push_goals_together.m:
compiler/quantification.m:
compiler/rbmm.add_rbmm_goal_infos.m:
compiler/rbmm.live_variable_analysis.m:
compiler/rbmm.points_to_analysis.m:
compiler/rbmm.points_to_graph.m:
compiler/rbmm.points_to_info.m:
compiler/rbmm.region_liveness_info.m:
compiler/rbmm.region_transformation.m:
compiler/recompute_instmap_deltas.m:
compiler/saved_vars.m:
compiler/simplify_goal_unify.m:
compiler/simplify_info.m:
compiler/simplify_proc.m:
compiler/size_prof.m:
compiler/ssdebug.m:
compiler/stack_alloc.m:
compiler/stack_layout.m:
compiler/stack_opt.m:
compiler/stm_expand.m:
compiler/store_alloc.m:
compiler/structure_reuse.analysis.m:
compiler/structure_reuse.direct.choose_reuse.m:
compiler/structure_reuse.direct.detect_garbage.m:
compiler/structure_reuse.domain.m:
compiler/structure_reuse.indirect.m:
compiler/structure_reuse.lbu.m:
compiler/structure_reuse.lfu.m:
compiler/structure_reuse.versions.m:
compiler/structure_sharing.analysis.m:
compiler/structure_sharing.domain.m:
compiler/switch_detection.m:
compiler/table_gen.m:
compiler/tabling_analysis.m:
compiler/term_constr_build.m:
compiler/term_constr_initial.m:
compiler/term_errors.m:
compiler/term_pass1.m:
compiler/term_pass2.m:
compiler/trace_gen.m:
compiler/trailing_analysis.m:
compiler/try_expand.m:
compiler/tupling.m:
compiler/unneeded_code.m:
compiler/untupling.m:
compiler/unused_args.m:
compiler/unused_imports.m:
    Conform to the changes above. Mostly this means

    - not passing a module_info to get a var_table out of a proc_info, but
    - having to pass a module_info to code that either constructs a var_table,
      or adds entries to a var_table (since we now need the type table
      to figure out whether variables' types are dummies).
2022-08-18 18:53:15 +10:00
Zoltan Somogyi
4c9d04434a Classify pred_names into four categories.
compiler/pred_name.m:
    Group pred_origins into four categories, giving each category its own
    function symbol. The categories are

    - predicates that contain, or may contain, code directly written
      by the user;
    - predicates created wholly by the compiler,
    - predicates created by the compiler by transforming a predicate, and
    - predicates created by the compiler by transforming a procedure.

    We distinguish between the first two because we want to report
    errors only in user-written code, since reporting an error that
    the user is powerless to fix is not a good idea.

    We distinguish between the last two just to allow us to store
    the proc_id of the transformed procedure next to its pred_id.

compiler/higher_order.m:
    Replace a boolean with value of a bespoke type.

    Rename some predicates to avoid ambiguity.

compiler/*.m:
    Conform to the changes above.
2022-07-23 09:28:40 +10:00
Zoltan Somogyi
1eb1e239b3 Move the pred_origin type to pred_name.m.
compiler/pred_name.m:
    Add the pred_origin type and its component types, moved here from
    hlds_pred.m and hlds_rtti.m.

    Also, add the functions and predicates that convert pred_origins to
    strings, moved here from hlds_pred.m, hlds_out_util.m and layout_out.m.

compiler/hlds_pred.m:
    Delete the pred_origin type moved to pred_name.m.

compiler/hlds_rtti.m:
    Delete the instance_method_constraints type moved to pred_name.m.
    It has nothing to do with RTTI, and was not used in hlds_rtti.m itself.
    The only data structure it is part of is pred_origin, though
    it is used as temporary data by a few other modules.

compiler/hlds_out_util.m:
compiler/hlds_pred.m:
compiler/layout_out.m:
    Delete the functions and predicates moved to pred_name.m.

compiler/*.m:
    Conform to the change above, mostly by adding imports of pred_name.m,
    in a few cases replacing hlds_pred.m or hlds_rtti.m.
2022-07-21 05:02:44 +10:00
Zoltan Somogyi
28f0000487 Rename predicates to avoid ambiguities. 2022-07-06 14:33:10 +10:00
Zoltan Somogyi
404fea1bd2 Start removing non-var_table versions of predicates.
compiler/arg_info.m:
compiler/goal_util.m:
compiler/hlds_rtti.m:
compiler/instmap.m:
compiler/recompute_instmap_deltas.m:
compiler/type_util.m:
    For predicates which had both varset/vartypes and var_table versions,
    but the former is not used anymore because all its callers have been
    switched to the latter,

    - delete the former, and
    - rename the latter to the name of the former.

    In goal_util.m, switch two currently-unused predicates to use var_tables
    instead of varsets/vartypes, in case they are needed again.

compiler/hlds_pred.m:
    Likewise replace define_new_pred with define_new_pred_vt, but also
    change its implementation to use var_table for everything except
    the final construction of the proc_info.

compiler/accumulator.m:
compiler/call_gen.m:
compiler/code_loc_dep.m:
compiler/constraint.m:
compiler/deforest.m:
compiler/delay_construct.m:
compiler/dep_par_conj.m:
compiler/det_analysis.m:
compiler/det_util.m:
compiler/float_regs.m:
compiler/follow_code.m:
compiler/higher_order.m:
compiler/interval.m:
compiler/lambda.m:
compiler/lco.m:
compiler/live_vars.m:
compiler/liveness.m:
compiler/loop_inv.m:
compiler/ml_code_gen.m:
compiler/modes.m:
compiler/pd_info.m:
compiler/pd_util.m:
compiler/push_goals_together.m:
compiler/rbmm.region_liveness_info.m:
compiler/saved_vars.m:
compiler/simplify_goal.m:
compiler/simplify_proc.m:
compiler/size_prof.m:
compiler/ssdebug.m:
compiler/structure_reuse.indirect.m:
compiler/structure_reuse.lbu.m:
compiler/structure_reuse.lfu.m:
compiler/table_gen.m:
compiler/tupling.m:
compiler/unneeded_code.m:
compiler/untupling.m:
    Conform to the changes above.
2022-05-15 21:40:10 +10:00
Zoltan Somogyi
b106006977 Prep for storing variable types in clauses_infos.
compiler/hlds_clauses.m:
    Provide a mechanism for code that creates clauses_infos to specify the
    types of the arguments. Comment it out for now, with an explanation of
    *why*.

compiler/higher_order.m:
    Similarly, write but comment out code that would create clauses_infos
    with filled in variable types.

    Encode the invariant that new predicates have one argument type
    for each argument (duh) into the higher order specialization request.

    Change the prefix on a type's function symbols in order to avoid
    ambiguity.

    Fix some misleading predicate and variable names.

    Replace a semidet function with a predicate.

compiler/arg_info.m:
    Switch a predicate to use var_tables instead of vartypes.

    Fix argument order.

compiler/table_gen.m:
    Switch a predicate to use var_tables instead of varsets/vartypes.

compiler/add_pred.m:
compiler/add_special_pred.m:
compiler/instance_method_clauses.m:
compiler/liveness.m:
compiler/stack_opt.m:
compiler/tupling.m:
    Conform to the changes above.
2022-05-15 17:15:05 +10:00
Zoltan Somogyi
d667194642 Introduce a new type for effective trace levels.
We have two main notions of trace levels. The first is the global trace level,
which is set by compiler options, and the second is the effective trace level
for a given procedure. The two are different not just in that the effective
trace level for a procedure may differ from the global trace level, but also
in that there exist effective trace levels that cannot be specified using
compiler options.

compiler/trace_params.m:
    Add the new type eff_trace_level for representing effective trace levels.
    (Old code has long used "Eff" as an abbreviation for "effective".)
    Use it where relevant.

    Delete functions that (a) first compute the effective trace level
    for a procedure, and (b) then test that effective trace level,
    and replace each of them with a function that does only (b).
    There was already a function that did only (a); rename it to avoid
    an ambiguity.

compiler/code_info.m:
    Store the effective trace level of the procedure being translated
    in the code_info, to save it from having to be recomputed many times.

compiler/code_loc_dep.m:
    Get the effective trace level for the procedure being compiled
    from code_info.

compiler/hlds_out_pred.m:
    Write out each procedure's effective trace level.

compiler/llds.m:
    Include the effective trace level in generated c_procs, for use by
    continuation_info.m.

compiler/continuation_info.m:
    Rename a predicate to avoid a name clash.

    Conform to the changes above.

compiler/handle_options.m:
    Note a non-problem.

compiler/globals.m:
compiler/layout.m:
compiler/layout_out.m:
compiler/liveness.m:
compiler/optimize.m:
compiler/proc_gen.m:
compiler/simplify_goal_conj.m:
compiler/simplify_goal_scope.m:
compiler/simplify_info.m:
compiler/stack_alloc.m:
compiler/stack_layout.m:
compiler/store_alloc.m:
compiler/trace_gen.m:
compiler/transform_llds.m:
    Conform to the changes above.

compiler/mercury_compile_front_end.m:
    Fix a misleading predicate name.

compiler/hlds_out_module.m:
    Simplify some code.

runtime/mercury_goto.h:
    Fix misplaced/wrong casts and stray backslashes in macros that are usually
    only used when debugging the debugger.
2022-05-01 05:34:10 +10:00
Zoltan Somogyi
33870445b8 Convert more modules to use var_tables.
compiler/follow_vars.m:
compiler/liveness.m:
compiler/saved_vars.m:
compiler/stack_alloc.m:
compiler/store_alloc.m:
compiler/try_expand.m:
compiler/unused_imports.m:
compiler/var_locn.m:
    Convert these modules to use var_tables.

    In many predicates, fix argument order.

compiler/live_vars.m:
    Change the way that this support module keeps track of which
    variables to treat as dummy variables. Instead of an array with
    effectively a boolean slot for each variable, use a var_table,
    but with provision for a user of live_vars.m to specify that
    *no* variable is to be treated as a dummy, not even variables
    whose types are dummy types. (Some modules that import live_vars.m
    want this option.)

compiler/hlds_rtti.m:
    Provide var_table-using versions of existing predicates,
    and fix their argument order.

compiler/code_loc_dep.m:
compiler/delay_construct.m:
compiler/stack_opt.m:
compiler/tupling.m:
    Conform to the changes above.
2022-04-30 13:27:02 +10:00
Zoltan Somogyi
ea4f95a7ed Use var_tables in lco.m, and when dumping goals.
Since this is the first converted module that dumps out goals when
debugging trace flags are enabled, this required generalizing the code
that does that, to take either varsets or var_tables as a means of
specifying the names of variables. We do this via a new type,
var_name_source, which contains either a varset or a var_table.

Almost all of this diff is there to implement this generalization.
A large part of it affects code in the parse_tree package that we use
to write out the parts of HLDS goals that are defined by types defined
in that package. Since we want to avoid making any part of the parse_tree
package dependent on the hlds package, this required defining the
var_name_source type in the parse_tree package, which in turn requires
var_table.m to be in that same package.

compiler/lco.m:
    Convert this module to use var_tables instead of varsets and vartypes.

compiler/var_table.m:
    Move this module from the hlds package to the parse_tree package.

    To make this, possible, move the parts that required access to the HLDS
    to hlds_pred.m, from where it was usually invoked.

    Export some utility predicates to allow the moved code to work
    in hlds_pred.m without access to the actual definition of the
    var_table type.

    Define the var_name_source type.

    Add some utility functions for use by code writing out variable names.

compiler/hlds_pred.m:
    Add the code moved from var_table.m.

compiler/vartypes.m:
    Move this module from the hlds package to the parse_tree package,
    for symmetry with var_table.m. It did not depend on being in hlds
    in any way.

compiler/hlds.m:
compiler/parse_tree.m:
    Move vartypes.m and var_table.m from the hlds package
    to the parse_tree package.

compiler/hlds_out_goal.m:
    Change all the predicates in this module to take a var_name_source
    instead of a prog_varset.

    Fix some comments.

compiler/hlds_out_util.m:
    Change some of the predicates in this module (those called from
    hlds_out_goal.m) to take a var_name_source instead of a prog_varset.

compiler/parse_tree_out_term.m:
    Provide variants of some existing predicates and functions that take
    var_name_sources instead of varsets. The code of the copies
    duplicates the logic of the originals, though I hope that this
    duplication can be done away with at the end of the transition.
    (The best solution would be to use a typeclass with methods
    that convert vars to their names, but we would want to ensure
    that the compiler can specialize all the affected predicates
    and functions to the two instances of this typeclass, which is
    something that we cannot do yet. In the meantime, the lack of
    any generalization in the old versions preserves their performance.)

tools/sort_imports:
tools/filter_sort_imports:
    A new tool that automatically sorts any occurrences of consecutive
    ":- import_module" declarations in the named files. The sorting is done
    in filter_sort_imports; sort_imports loops over the named files.

    After automatically replacing all occurrences of hlds.{vartypes,var_table}
    in import_module declarations with their parse_tree versions, the updated
    import_module declarations were usually out of order with respect to
    their neighbours. I used this script to fix that, and some earlier
    out-of-order imports.

compiler/accumulator.m:
compiler/add_class.m:
compiler/add_clause.m:
compiler/add_foreign_proc.m:
compiler/add_heap_ops.m:
compiler/add_pragma_type_spec.m:
compiler/add_pred.m:
compiler/add_trail_ops.m:
compiler/analysis.m:
compiler/arg_info.m:
compiler/build_mode_constraints.m:
compiler/bytecode_gen.m:
compiler/call_gen.m:
compiler/check_promise.m:
compiler/closure_analysis.m:
compiler/closure_gen.m:
compiler/code_info.m:
compiler/code_loc_dep.m:
compiler/common.m:
compiler/compile_target_code.m:
compiler/complexity.m:
compiler/const_prop.m:
compiler/constraint.m:
compiler/continuation_info.m:
compiler/convert_parse_tree.m:
compiler/coverage_profiling.m:
compiler/cse_detection.m:
compiler/ctgc.datastruct.m:
compiler/ctgc.util.m:
compiler/dead_proc_elim.m:
compiler/deep_profiling.m:
compiler/deforest.m:
compiler/delay_construct.m:
compiler/delay_partial_inst.m:
compiler/dep_par_conj.m:
compiler/det_analysis.m:
compiler/det_report.m:
compiler/det_util.m:
compiler/direct_arg_in_out.m:
compiler/disj_gen.m:
compiler/distance_granularity.m:
compiler/equiv_type_hlds.m:
compiler/exception_analysis.m:
compiler/file_names.m:
compiler/float_regs.m:
compiler/follow_vars.m:
compiler/format_call.m:
compiler/generate_dep_d_files.m:
compiler/get_dependencies.m:
compiler/goal_expr_to_goal.m:
compiler/goal_mode.m:
compiler/goal_path.m:
compiler/goal_store.m:
compiler/goal_util.m:
compiler/granularity.m:
compiler/hhf.m:
compiler/higher_order.m:
compiler/hlds_clauses.m:
compiler/hlds_code_util.m:
compiler/hlds_error_util.m:
compiler/hlds_goal.m:
compiler/hlds_llds.m:
compiler/hlds_out_pred.m:
compiler/hlds_rtti.m:
compiler/hlds_statistics.m:
compiler/inlining.m:
compiler/inst_check.m:
compiler/inst_test.m:
compiler/inst_user.m:
compiler/instance_method_clauses.m:
compiler/instmap.m:
compiler/intermod.m:
compiler/intermod_analysis.m:
compiler/interval.m:
compiler/introduce_exists_casts.m:
compiler/introduce_parallelism.m:
compiler/item_util.m:
compiler/lambda.m:
compiler/live_vars.m:
compiler/liveness.m:
compiler/llds.m:
compiler/llds_out_data.m:
compiler/llds_out_file.m:
compiler/llds_out_util.m:
compiler/lookup_switch.m:
compiler/loop_inv.m:
compiler/make.module_target.m:
compiler/make.util.m:
compiler/make_goal.m:
compiler/make_hlds_separate_items.m:
compiler/make_hlds_types.m:
compiler/mark_tail_calls.m:
compiler/mercury_compile_mlds_back_end.m:
compiler/middle_rec.m:
compiler/ml_accurate_gc.m:
compiler/ml_args_util.m:
compiler/ml_call_gen.m:
compiler/ml_closure_gen.m:
compiler/ml_code_gen.m:
compiler/ml_code_util.m:
compiler/ml_commit_gen.m:
compiler/ml_disj_gen.m:
compiler/ml_foreign_proc_gen.m:
compiler/ml_gen_info.m:
compiler/ml_lookup_switch.m:
compiler/ml_proc_gen.m:
compiler/ml_simplify_switch.m:
compiler/ml_switch_gen.m:
compiler/ml_tag_switch.m:
compiler/ml_unify_gen.m:
compiler/ml_unify_gen_construct.m:
compiler/ml_unify_gen_deconstruct.m:
compiler/ml_unify_gen_test.m:
compiler/ml_unify_gen_util.m:
compiler/mlds_to_c_data.m:
compiler/mlds_to_c_func.m:
compiler/mlds_to_c_global.m:
compiler/mlds_to_cs_class.m:
compiler/mlds_to_cs_file.m:
compiler/mlds_to_java_data.m:
compiler/mlds_to_java_file.m:
compiler/mlds_to_java_stmt.m:
compiler/mlds_to_java_type.m:
compiler/mmc_analysis.m:
compiler/mode_comparison.m:
compiler/mode_constraints.m:
compiler/mode_debug.m:
compiler/mode_errors.m:
compiler/mode_info.m:
compiler/mode_ordering.m:
compiler/modecheck_call.m:
compiler/modecheck_coerce.m:
compiler/modecheck_goal.m:
compiler/modecheck_unify.m:
compiler/modecheck_util.m:
compiler/modes.m:
compiler/module_cmds.m:
compiler/old_type_constraints.m:
compiler/opt_debug.m:
compiler/optimize.m:
compiler/options_file.m:
compiler/ordering_mode_constraints.m:
compiler/par_loop_control.m:
compiler/parse_item.m:
compiler/parse_string_format.m:
compiler/parse_tree_out_inst.m:
compiler/parse_tree_to_term.m:
compiler/parse_util.m:
compiler/pd_debug.m:
compiler/pd_info.m:
compiler/pd_util.m:
compiler/peephole.m:
compiler/polymorphism.m:
compiler/polymorphism_info.m:
compiler/polymorphism_lambda.m:
compiler/polymorphism_type_class_info.m:
compiler/polymorphism_type_info.m:
compiler/post_typecheck.m:
compiler/pragma_c_gen.m:
compiler/pred_name.m:
compiler/pred_table.m:
compiler/prog_item.m:
compiler/prog_rep.m:
compiler/prop_mode_constraints.m:
compiler/purity.m:
compiler/push_goals_together.m:
compiler/qual_info.m:
compiler/quantification.m:
compiler/rbmm.execution_path.m:
compiler/rbmm.m:
compiler/rbmm.points_to_analysis.m:
compiler/rbmm.points_to_graph.m:
compiler/rbmm.points_to_info.m:
compiler/rbmm.region_resurrection_renaming.m:
compiler/rbmm.region_transformation.m:
compiler/recompilation.used_file.m:
compiler/recompilation.version.m:
compiler/recompute_instmap_deltas.m:
compiler/resolve_unify_functor.m:
compiler/rtti.m:
compiler/rtti_out.m:
compiler/rtti_to_mlds.m:
compiler/saved_vars.m:
compiler/set_of_var.m:
compiler/simplify_goal_call.m:
compiler/simplify_goal_conj.m:
compiler/simplify_goal_disj.m:
compiler/simplify_goal_ite.m:
compiler/simplify_goal_scope.m:
compiler/simplify_goal_switch.m:
compiler/simplify_goal_unify.m:
compiler/simplify_info.m:
compiler/simplify_proc.m:
compiler/size_prof.m:
compiler/smm_common.m:
compiler/ssdebug.m:
compiler/stack_alloc.m:
compiler/stack_layout.m:
compiler/stack_opt.m:
compiler/stm_expand.m:
compiler/store_alloc.m:
compiler/structure_reuse.analysis.m:
compiler/structure_reuse.direct.choose_reuse.m:
compiler/structure_reuse.direct.detect_garbage.m:
compiler/structure_reuse.domain.m:
compiler/structure_reuse.indirect.m:
compiler/structure_reuse.lbu.m:
compiler/structure_reuse.lfu.m:
compiler/structure_sharing.analysis.m:
compiler/structure_sharing.domain.m:
compiler/superhomogeneous.m:
compiler/switch_detection.m:
compiler/switch_gen.m:
compiler/switch_util.m:
compiler/table_gen.m:
compiler/tabling_analysis.m:
compiler/term_constr_build.m:
compiler/term_constr_data.m:
compiler/term_constr_initial.m:
compiler/term_constr_main.m:
compiler/term_constr_main_types.m:
compiler/term_constr_util.m:
compiler/term_pass1.m:
compiler/term_traversal.m:
compiler/term_util.m:
compiler/trace_gen.m:
compiler/trailing_analysis.m:
compiler/transform_llds.m:
compiler/try_expand.m:
compiler/tupling.m:
compiler/type_assign.m:
compiler/type_ctor_info.m:
compiler/type_util.m:
compiler/typecheck.m:
compiler/typecheck_debug.m:
compiler/typecheck_errors.m:
compiler/typecheck_info.m:
compiler/unify_gen_construct.m:
compiler/unify_gen_deconstruct.m:
compiler/unify_proc.m:
compiler/unique_modes.m:
compiler/unneeded_code.m:
compiler/untupling.m:
compiler/unused_args.m:
compiler/unused_imports.m:
compiler/var_locn.m:
compiler/write_deps_file.m:
compiler/write_module_interface_files.m:
    Conform to the changes above.
2022-04-18 02:00:38 +10:00
Zoltan Somogyi
3f3045c9e2 Get and set varsets/vartypes in proc_infos together.
compiler/hlds_pred.m:
    We eventually want to replace the varset and vartypes fields in
    each proc_info with a var_table, but it is not practical to do so
    at once; it will have to be done gradually, a few modules at most
    at a time. During this process, we will need a way either

    - to let already converted modules get a var_table out of the proc_info,
      and put an updated var_table back into a proc_info, even though
      proc_infos still contain varset and vartypes fields, or

    - to let not-yet-converted modules get varsets and vartypes out of the
      proc_info, and put updated varsets and vartypes back into a proc_info,
      even though proc_infos already store a var_table.

    The latter cannot be done in two halves (i.e. set the varset half
    of the var_table, and then set its vartypes half), and while the former
    *can* be done that way, it is more efficient to do them at the same time.

    Therefore as a first step, this diff replaces the indiviual getter
    and setter predicates of the varset and vartypes fields of proc_info
    with a getter that gets both and a setter that sets both.

    Put the varset and vartypes next to each other in a structure.

compiler/code_info.m:
    Delete a function that duplicates a function in var_table.m.

    Conform to the change above.

compiler/det_report.m:
    Factor out some common code.

    Conform to the change above.

compiler/det_util.m:
    Delete a no-longer-needed predicate.

    Conform to the change above.

compiler/higher_order.m:
    Fix an old oversight: when deleting variables from the vartypes,
    delete them from the varset as well.

    Conform to the change above.

compiler/liveness.m:
    Avoid constructing and traversing a list unnecessarily.

    Conform to the change above.

compiler/accumulator.m:
compiler/add_heap_ops.m:
compiler/add_trail_ops.m:
compiler/arg_info.m:
compiler/build_mode_constraints.m:
compiler/bytecode_gen.m:
compiler/call_gen.m:
compiler/clause_to_proc.m:
compiler/closure_analysis.m:
compiler/code_gen.m:
compiler/code_loc_dep.m:
compiler/complexity.m:
compiler/continuation_info.m:
compiler/cse_detection.m:
compiler/ctgc.datastruct.m:
compiler/ctgc.util.m:
compiler/deep_profiling.m:
compiler/deforest.m:
compiler/delay_construct.m:
compiler/delay_partial_inst.m:
compiler/dep_par_conj.m:
compiler/det_analysis.m:
compiler/direct_arg_in_out.m:
compiler/disj_gen.m:
compiler/equiv_type_hlds.m:
compiler/exception_analysis.m:
compiler/float_regs.m:
compiler/follow_code.m:
compiler/goal_mode.m:
compiler/goal_path.m:
compiler/hlds_out_pred.m:
compiler/hlds_rtti.m:
compiler/hlds_statistics.m:
compiler/inlining.m:
compiler/intermod.m:
compiler/intermod_analysis.m:
compiler/introduce_exists_casts.m:
compiler/introduce_parallelism.m:
compiler/lambda.m:
compiler/lco.m:
compiler/live_vars.m:
compiler/loop_inv.m:
compiler/mark_tail_calls.m:
compiler/ml_accurate_gc.m:
compiler/ml_args_util.m:
compiler/ml_closure_gen.m:
compiler/ml_gen_info.m:
compiler/ml_proc_gen.m:
compiler/mode_info.m:
compiler/modecheck_goal.m:
compiler/modes.m:
compiler/par_loop_control.m:
compiler/pd_debug.m:
compiler/pd_info.m:
compiler/pd_util.m:
compiler/polymorphism_info.m:
compiler/proc_gen.m:
compiler/purity.m:
compiler/push_goals_together.m:
compiler/quantification.m:
compiler/rbmm.add_rbmm_goal_infos.m:
compiler/rbmm.live_variable_analysis.m:
compiler/rbmm.points_to_graph.m:
compiler/rbmm.points_to_info.m:
compiler/rbmm.region_liveness_info.m:
compiler/rbmm.region_transformation.m:
compiler/recompute_instmap_deltas.m:
compiler/saved_vars.m:
compiler/simplify_goal_unify.m:
compiler/simplify_info.m:
compiler/simplify_proc.m:
compiler/size_prof.m:
compiler/ssdebug.m:
compiler/stack_alloc.m:
compiler/stack_layout.m:
compiler/stack_opt.m:
compiler/stm_expand.m:
compiler/store_alloc.m:
compiler/structure_reuse.analysis.m:
compiler/structure_reuse.direct.choose_reuse.m:
compiler/structure_reuse.direct.detect_garbage.m:
compiler/structure_reuse.indirect.m:
compiler/structure_reuse.lbu.m:
compiler/structure_reuse.lfu.m:
compiler/structure_sharing.analysis.m:
compiler/structure_sharing.domain.m:
compiler/switch_detection.m:
compiler/table_gen.m:
compiler/tabling_analysis.m:
compiler/term_constr_build.m:
compiler/term_constr_initial.m:
compiler/term_errors.m:
compiler/term_pass1.m:
compiler/term_pass2.m:
compiler/trace_gen.m:
compiler/trailing_analysis.m:
compiler/try_expand.m:
compiler/tupling.m:
compiler/unneeded_code.m:
compiler/untupling.m:
compiler/unused_args.m:
compiler/unused_imports.m:
    Conform to the change above.
2022-04-07 21:22:21 +10:00
Zoltan Somogyi
8ebe125a6a Introduce var_table.m.
Most compiler passes need to know both the names and the types
of the variables they operate on. Until now, they had to pass along
two separate data structures for that, the varset and the vartypes,
and many operations required looking a variable up in both of these.

The var table is a single data structure that records for each variable

- its name, as the varset has traditionally done,
- its type, as the vartypes has traditionally done,
- the is_dummy_type flag which says whether its type is a dummy type,
  which traditionally had to computed afresh at each lookup.

Switch the MLDS code generator to use var_tables instead of varsets and
vartypes. The code generator often needs to know the name and the type
of a variable at the same time, and it often needs to know which variables'
types are dummies, often enough that precomputing this info should be a win.

compiler/var_table.m:
    Add this new module which defines the var_table.

    Its operations are modelled after the operation in var_types.m.

compiler/hlds.m:
compiler/notes/compiler_design.html:
    Add the new module to the hlds package.

compiler/prog_type.m:
compiler/type_util.m:
    Move the is_dummy_type from type_util.m, which is in the
    check_hlds package, to prog_type.m, which in the parse_tree package,
    to avoid having this part of the hlds package depend on check_hlds.
    (It already depends on parse_tree, for a lot of different things.)

    Given a function and a predicate that each took a vartypes arg,
    make new versions that take a var_table arg instead.
    Rationalize the argument list of the function.

compiler/ml_gen_info.m:
    Replace the varset and vartypes fields of the ml_gen_info with a
    var_table field.

compiler/ml_code_util.m:
    Replace code that used to operate on varsets and vartypes with code
    that operates on var_tables.

    Create new versions of a few operations to exploit the info in var_tables.

    Give some predicates more meaningful names.

compiler/ml_accurate_gc.m:
compiler/ml_args_util.m:
compiler/ml_call_gen.m:
compiler/ml_closure_gen.m:
compiler/ml_code_gen.m:
compiler/ml_commit_gen.m:
compiler/ml_disj_gen.m:
compiler/ml_foreign_proc_gen.m:
compiler/ml_lookup_switch.m:
compiler/ml_proc_gen.m:
compiler/ml_switch_gen.m:
compiler/ml_tag_switch.m:
compiler/ml_unify_gen.m:
compiler/ml_unify_gen_construct.m:
compiler/ml_unify_gen_deconstruct.m:
compiler/ml_unify_gen_test.m:
compiler/ml_unify_gen_util.m:
    Replace code that used to operate on varsets and vartypes with code
    that operates on var_tables.

    In ml_switch_gen.m and ml_tag_switch.m, put some predicates' arguments
    into an reasonable order by moving related args next to each other.

compiler/vartypes.m:
    Delete an operation that was only needed in the MLDS backend,
    in code that this diff replaces.

compiler/switch_util.m:
    Put the larger input first in the arg list of a predicate.

compiler/closure_gen.m:
compiler/code_info.m:
compiler/code_loc_dep.m:
compiler/export.m:
compiler/lambda.m:
compiler/live_vars.m:
compiler/liveness.m:
compiler/llds.m:
compiler/llds_out_instr.m:
compiler/mark_tail_calls.m:
compiler/opt_debug.m:
compiler/opt_util.m:
compiler/stack_alloc.m:
compiler/stack_layout.m:
compiler/tag_switch.m:
compiler/term_constr_util.m:
compiler/tupling.m:
compiler/unify_gen.m:
compiler/unify_gen_deconstruct.m:
compiler/var_locn.m:
    Conform to the changes above.
2022-03-28 10:20:49 +11:00
Zoltan Somogyi
eecab63251 Improve programming style. 2022-02-15 01:12:53 +11:00
Zoltan Somogyi
d76c7bf617 Break up inst_util.m and mode_util.m.
This step significantly improves module cohesion.

compiler/inst_abstract_unify.m:
    New module carved out of inst_util.m, which does abstract unifications
    on insts.

compiler/inst_merge.m:
    New module carved out of inst_util.m, which merges insts.

compiler/inst_lookup.m:
    New module carved partly out of inst_util.m and partly out of mode_util.m,
    which looks up insts in the module_info, and then possibly expands out
    the result.

compiler/mode_test.m:
    New module carved out of mode_util.m, whose predicates
    perform tests on modes.

compiler/mode_top_functor.m:
    New module carved out of mode_util.m, which computes top_functor_modes
    from modes.

compiler/inst_mode_type_prop.m:
    New module carved out of mode_util.m, which propagates type information
    into both insts and modes.

compiler/recompute_instmap_deltas.m:
    New module carved out of mode_util.m, which recomputes goals'
    instmap_deltas.

compiler/inst_test.m:
    Move here the predicates in inst_util.m that perform tests on insts.

compiler/inst_util.m:
compiler/mode_util.m:
    Delete the code that this diff moves to other modules.

compiler/check_hlds.m:
    Add the new modules to the check_hlds package, the package that also
    contains inst_util.m and mode_util.m. (Some of these modules could
    be argued to fit better in the hlds package, but moving them there
    would not be desirable while they depend on code that is still in the
    check_hlds package.)

compiler/notes/compiler_design.html:
    Document the new modules.

compiler/add_pragma_tabling.m:
compiler/arg_info.m:
compiler/bytecode_gen.m:
compiler/closure_analysis.m:
compiler/complexity.m:
compiler/deep_profiling.m:
compiler/deforest.m:
compiler/dep_par_conj.m:
compiler/det_report.m:
compiler/direct_arg_in_out.m:
compiler/distance_granularity.m:
compiler/equiv_type_hlds.m:
compiler/error_msg_inst.m:
compiler/fact_table.m:
compiler/float_regs.m:
compiler/follow_code.m:
compiler/goal_util.m:
compiler/higher_order.m:
compiler/hlds_pred.m:
compiler/hlds_rtti.m:
compiler/inlining.m:
compiler/inst_match.m:
compiler/inst_user.m:
compiler/instmap.m:
compiler/intermod.m:
compiler/interval.m:
compiler/introduce_exists_casts.m:
compiler/lambda.m:
compiler/lco.m:
compiler/liveness.m:
compiler/lookup_util.m:
compiler/loop_inv.m:
compiler/mark_tail_calls.m:
compiler/ml_args_util.m:
compiler/ml_code_util.m:
compiler/ml_foreign_proc_gen.m:
compiler/ml_unify_gen_construct.m:
compiler/ml_unify_gen_util.m:
compiler/mode_constraints.m:
compiler/mode_errors.m:
compiler/modecheck_call.m:
compiler/modecheck_coerce.m:
compiler/modecheck_goal.m:
compiler/modecheck_unify.m:
compiler/modecheck_util.m:
compiler/modes.m:
compiler/oisu_check.m:
compiler/par_conj_gen.m:
compiler/pd_util.m:
compiler/post_typecheck.m:
compiler/pragma_c_gen.m:
compiler/proc_requests.m:
compiler/prog_rep.m:
compiler/push_goals_together.m:
compiler/rbmm.region_transformation.m:
compiler/saved_vars.m:
compiler/simplify_goal_switch.m:
compiler/simplify_proc.m:
compiler/size_prof.m:
compiler/ssdebug.m:
compiler/stack_opt.m:
compiler/stm_expand.m:
compiler/stratify.m:
compiler/structure_reuse.versions.m:
compiler/structure_sharing.domain.m:
compiler/superhomogeneous.m:
compiler/table_gen.m:
compiler/term_constr_build.m:
compiler/term_pass2.m:
compiler/term_util.m:
compiler/tupling.m:
compiler/unify_gen_construct.m:
compiler/unify_gen_util.m:
compiler/unique_modes.m:
compiler/unneeded_code.m:
compiler/untupling.m:
compiler/unused_args.m:
    Conform to the changes above by importing the required new modules,
    sometimes in addition to inst_util.m or mode_util.m, but more usually
    instead of them.
2021-12-16 01:31:35 +11:00
Zoltan Somogyi
48e714d43f Make constant prop work with loop invariant opt.
compiler/common.m:
    The code that tries to optimize X = f(...) into X = Y if Y already
    contains f(...) used to insist on the X = f(...) construction unification
    being marked as a dynamic unification, i.e. one that constructs a term
    on the heap on each invocation. This was part of the fix of Mantis bug
    #493, which affected only the MLDS code generator, but for LLDS backend,
    in the presence of --loop-invariants, it prevented a constant propagation
    optimization that we had a test for (tests/hard_coded/constant_prop_2).
    So make both backends happy by insisting on construct_dynamically
    only for the MLDS backend.

compiler/simplify_info.m:
    Record for common.m whether the backend we are targeting pays
    any attention to whether a cell is construct_dynamically.

    Replace some bools with bespoke types, to eliminate the risk of confusion.

compiler/hlds_goal.m:
    For each construction unification marked construct_statically, record
    whether the term was "born static" by being created as a static term
    by a compiler pass, or whether it is a user-written unification that was
    "marked static" by mark_static_terms.m. Document the meaning of both.
    (I originally thought this distinction would be useful in the bug fix,
    but it turned out not to be.)

compiler/deep_profiling.m:
compiler/dep_par_conj.m:
compiler/modecheck_goal.m:
compiler/modecheck_unify.m:
compiler/polymorphism.m:
compiler/polymorphism_type_info.m:
    Record compiler-generated static terms as born static.

compiler/mark_static_terms.m:
    Mark discovered-to-be-static terms as marked static.

compiler/hlds_out_goal.m:
compiler/interval.m:
compiler/liveness.m:
compiler/loop_inv.m:
compiler/ml_unify_gen_construct.m:
compiler/quantification.m:
compiler/rbmm.add_rbmm_goal_infos.m:
compiler/simplify_goal.m:
compiler/simplify_goal_conj.m:
compiler/simplify_goal_disj.m:
compiler/simplify_goal_scope.m:
compiler/structure_reuse.indirect.m:
compiler/structure_reuse.versions.m:
compiler/unify_gen_construct.m:
compiler/var_locn.m:
    Conform to the changes above.

tests/hard_coded/constant_prop_loop_inv.{m,exp}:
    A new test case. It contains the part of the constant_prop_2 test case
    that used to fail in LLDS grades with --loop-invariants.

tests/hard_coded/Mercury.options:
    Specify --loop-invariants for the new test case, even if it is not
    specified for constant_prop_2.

tests/hard_coded/Mmakefile:
    Enable the new test case.

tests/hard_coded/constant_prop_2.m:
    Fix programming style.
2021-05-13 13:34:07 +10:00
Zoltan Somogyi
5f50259d16 Write to explicitly named streams in many modules.
Right now, most parts of the compiler write to the "current output stream".
This was a pragmatic choice at the time, but has not aged well. The problem
is that the answer to the question "where is the current output stream going?"
is not obvious in *all* places in the compiler (although it is obvious in
most). When using such implicit streams, finding where the output is going
to in a given predicate requires inspecting not just the ancestors of that
predicate, but also all their older siblings (since any of them could have
changed the current stream), *including* their entire call trees. This is
usually an infeasible task. By constrast, if we explicitly pass streams
to all output operations, we need only follow the places where the variable
representing that stream is bound, which the mode system makes easy.

This diff switches large parts of the compiler over to doing output only
to explicitly passed streams, never to the implicit "current output stream".
The parts it switches over are the parts that rely to a significant degree
on the innermost change, which is to the "output" typeclass in
parse_tree_out_info.m. This is the part that has to be switched over to
explicit streams first, because (a) many modules such as mercury_to_mercury.m
rely on the output typeclass, and (b) most other modules that do output
call predicates in these modules. Starting anywhere else would be like
building a skyscraper starting at the top.

This typeclass, output(U), has two instances: output(io), and output(string),
so you could output either to the current output stream, or to a string.
To allow the specification of the destination stream in the first case,
this diff changes the typeclass to output(S, U) with a functional dependency
from U to S, with the two instances being output(io.text_output_stream, io)
and output(unit, string). (The unit arg is ignored in the second case.)

There is a complication with the output typeclass method, add_list, that
outputs a list of items. The complication is that each item is output
by a predicate supplied by the caller, but the separator between the items
(usually a comma) is output by add_list itself. We don't want to give
callers of this method the opportunity to screw up by specifying (possibly
implicitly) two different output streams for these two purposes, so we want
(a) the caller to tell add_list where to put the separators, and then
(b) for add_list, not its caller, tell the user-supplied predicate what
stream to write to. This works only if the stream argument is just before
the di,uo pair of I/O state arguments, which differs from our usual practice
of passing the stream at or near the left edge of the argument list,
not near the right. The result of this complication is that two categories
of predicates that are and are not used to print items in a list differ
in where they put the stream in their argument lists. This makes it easy
to pass the stream in the wrong argument position if you call a predicate
without looking up its signature, and may require *changing* the argument
order when a predicate is used to print an item in a list for the first time.
A complete switch over to always passing the stream just before !IO
would fix this inconsistency, but is far to big a change to make all at once.

compiler/parse_tree_out_info.m:
    Make the changes described above.

    Add write_out_list, which is a variant of io.write_list specifically
    designed to address the "complication" described above. It also has
    the arguments in an order that is better suited for higher-order use.

    Make the same change to argument order in the class method add_list
    as well.

Almost all of the following changes consist of passing an extra stream
argument to output predicates. In some places, where I thought this would
aid readability, I replaced sequences of calls to output predicates
with a single io.format.

compiler/prog_out.m:
    This module had many predicates that wrote things to the current output
    stream. This diff adds versions of these predicates that take an
    explicit stream argument.

    If the originals are still needed after the changes to the other modules,
    keep them, but add "_to_cur_stream" to the end of their names.
    Otherwise, delete them. (Many of the changes below replace
    write_xyz(..., !IO) with io.write_string(Stream, xyz_to_string(...), !IO),
    especially when write_xyz did nothing except call xyz_to_string
    and wrote out the result.)

compiler/c_util.m:
    Add either an explicit stream argument to the argument list, or a
    "_current_stream" suffix to the name, of every predicate defined
    in this module that does output.

    Add a new predicate to print out the block comment containing
    input for mkinit. This factors out common code in the LLDS and MLDS
    backends.

compiler/name_mangle.m:
    Delete all predicates that used to write to the current output stream,
    after replacing them if necessary with functions that return a string,
    which the caller can print to wherever it wants. (The "if necessary"
    part is there because some of the "replacement" functions already
    existed.)

    When converting a proc_label to a string, *always* require the caller
    to say whether the label prefix should be added to the string,
    instead of silently assuming "yes, add it", as calls to one of the old,
    now deleted predicates had it.

compiler/file_util.m:
    Add output_to_file_stream, a version of output_to_file which
    simply passes the output file stream it opens to the predicate
    that is intended to define the contents of the newly created or
    updated file. The existing output_to_file, which instead sets
    and resets the current output stream around the equivalent
    predicate call, is still needed e.g. by the MLDS backend,
    but hopefully for not too long.

compiler/mercury_to_mercury.m:
compiler/parse_tree_out.m:
compiler/parse_tree_out_clause.m:
compiler/parse_tree_out_inst.m:
compiler/parse_tree_out_pragma.m:
compiler/parse_tree_out_pred_decl.m:
compiler/parse_tree_out_term.m:
compiler/parse_tree_out_type_repn.m:
    Change the code writing out parse trees to explicitly pass a stream
    to every predicate that does output.

    In some places, this allows us to avoid changing the identity
    of the current output stream.

compiler/hlds_out.m:
compiler/hlds_out_goal.m:
compiler/hlds_out_mode.m:
compiler/hlds_out_module.m:
compiler/hlds_out_pred.m:
compiler/hlds_out_util.m:
compiler/intermod.m:
    Change the code writing out HLDS code to explicitly pass a stream
    to every predicate that does output. (The changes to these modules
    belong in this diff because these modules call many of the output
    predicates in the parse tree package.)

    In hlds_out_util.m, delete some write_to_xyz(...) predicates that wrote
    the result of xyz_to_string(...) to the current output stream.
    Replace calls to the deleted predicates with calls to io.write_string
    with the string being written being computed by xyz_to_string.

    Add a predicate to hlds_out_util.m that outputs a comment containing
    the current context, if it is valid. This factors out code that used
    to be common to several of the other modules.

    In a few places in hlds_out_module.m, the new code generates a
    slighly different set of blank lines, but this should not be a problem.

compiler/layout_out.m:
compiler/llds_out_code_addr.m:
compiler/llds_out_data.m:
compiler/llds_out_file.m:
compiler/llds_out_global.m:
compiler/llds_out_instr.m:
compiler/llds_out_util.m:
compiler/opt_debug.m:
compiler/rtti_out.m:
    Change the code writing out the LLDS to explicitly pass a stream
    to every predicate that does output. (The changes to these modules
    belong in this diff because layout_out.m and rtti_out.m call
    many of the output predicates in the parse tree package,
    and through them, the rest of the LLDS backend is affected as well.)

compiler/make.module_dep_file.m:
compiler/mercury_compile_main.m:
compiler/mercury_compile_middle_passes.m:
    Replace code that sets and resets the current output stream
    with code that simply passes an explicit output stream to a
    predicate that now *takes* an explicit stream as an argument.

compiler/accumulator.m:
compiler/add_clause.m:
compiler/code_gen.m:
compiler/code_loc_dep.m:
compiler/cse_detection.m:
compiler/delay_partial_inst.m:
compiler/dep_par_conj.m:
compiler/det_analysis.m:
compiler/error_msg_inst.m:
compiler/export.m:
compiler/format_call.m:
compiler/goal_expr_to_goal.m:
compiler/ite_gen.m:
compiler/lco.m:
compiler/liveness.m:
compiler/lp_rational.m:
compiler/mercury_compile_front_end.m:
compiler/mercury_compile_llds_back_end.m:
compiler/mlds_to_c_file.m:
compiler/mlds_to_c_global.m:
compiler/mode_debug.m:
compiler/mode_errors.m:
compiler/modes.m:
compiler/optimize.m:
compiler/passes_aux.m:
compiler/pd_debug.m:
compiler/pragma_c_gen.m:
compiler/proc_gen.m:
compiler/prog_ctgc.m:
compiler/push_goals_together.m:
compiler/rat.m:
compiler/recompilation.m:
compiler/recompilation.usage.m:
compiler/recompilation.version.m:
compiler/rtti.m:
compiler/saved_vars.m:
compiler/simplify_goal_conj.m:
compiler/stack_opt.m:
compiler/structure_reuse.analysis.m:
compiler/structure_reuse.domain.m:
compiler/structure_reuse.indirect.m:
compiler/structure_sharing.analysis.m:
compiler/superhomogeneous.m:
compiler/term_constr_build.m:
compiler/term_constr_data.m:
compiler/term_constr_fixpoint.m:
compiler/term_constr_pass2.m:
compiler/term_constr_util.m:
compiler/tupling.m:
compiler/type_assign.m:
compiler/unneeded_code.m:
compiler/write_deps_file.m:
    Conform to the changes above, mostly by passing streams explicitly.

compiler/hlds_dependency_graph.m:
    Conform to the changes above, mostly by passing streams explicitly.
    Move a predicate's definition next it only use.

compiler/Mercury.options:
    Specify --warn-implicit-stream-calls for all the modules in which
    this diff has replaced all implicit streams with explicit streams.
    (Unfortunately, debugging this diff has shown that --warn-implicit-
    stream-calls detects only *some*, and not *all*, uses of implicit
    streams.)

library/term_io.m:
    Fix documentation.
2020-11-14 15:07:55 +11:00
Zoltan Somogyi
206cc8503b Revisit valid vs all proc_ids in a pred_info.
compiler/hlds_pred.m:
    We have several predicates that retrieve selected subsets of all
    the proc_ids in a pred_info. For those that retrieve the proc_ids
    of only valid procedures, put "valid" into their names.

    Fix a bug in the implementation of pred_info_all_non_imported_proc_ids,
    which, despite its name, used to return the proc_ids of only the
    *valid* non-imported procedures.

    The distinction between all procedures and only valid procedures
    only really matters between mode analysis and the end of the front end.
    A procedure is valid if it has no mode errors, so before mode analysis,
    all procedures are valid by default, and if any procedure has any
    mode errors, the compiler should terminate after the front end is done.

    However, the distinction matters for readability, so this diff changes
    things so that we get all proc_ids in code executed before mode analysis,
    and valid proc_ids after the front end, with calls handled on a case-by-
    case basis in between.

    The distinction also matters in the presence of errors. For example,
    we shouldn't tell users that a predicate has no modes when it has
    modes that all happen to be invalid, and we should dump procedures
    into .hlds_dump files even if they are invalid, since their invalidity
    may be exactly what the user is trying to debug.

compiler/*.m:
    Make the changes described above.

    In some places, fix bad programming style.
2020-07-30 19:46:14 +10:00
Zoltan Somogyi
9d6c8d1780 Improve programming style.
compiler/hlds_llds.m:
    Give some function symbols more meaningful names.

compiler/code_loc_dep.m:
    Give some function symbols and variables more meaningful names.

    Replace list(prog_var) with set_of_progvar in the signatures
    of some predicates to express the invariant that the argument
    should not contain any duplicates.

    Provide a utility predicate for ite_gen.m.

    Generate more readable debug output.

compiler/ite_gen.m:
    Factor out some common code.

    Optimize some tests.

    Break up a predicate to reduce the level of indentation.

    Add some module qualifications to reduce type ambiguity.

compiler/var_locn.m:
    Separate the two use cases of init_var_locn_state_2, since one needs
    more work than the other. Factor out the parts that are common to both.

compiler/llds.m:
    Define a bespoke type to control whether auto-comments are printed or not.

compiler/code_gen.m:
compiler/disj_gen.m:
compiler/frameopt.m:
compiler/hlds_out_goal.m:
compiler/layout_out.m:
compiler/live_vars.m:
compiler/live_vars.m:
compiler/liveness.m:
compiler/liveness.m:
compiler/llds_out_file.m:
compiler/llds_out_instr.m:
compiler/llds_out_util.m:
compiler/lookup_switch.m:
compiler/lookup_switch.m:
compiler/opt_debug.m:
compiler/optimize.m:
compiler/use_local_vars.m:
    Conform to the changes above.
2020-07-17 10:48:13 +10:00
Zoltan Somogyi
4ef4402ecf Make --warn-inconsistent-pred-order-clauses default for the compiler.
compiler/COMP_FLAGS.in:
    As above.

compiler/Mercury.options:
    List the modules for we need --no-warn-inconsistent-pred-order-clauses
    for now.

compiler/call_gen.m:
compiler/code_util.m:
compiler/deep_profiling.m:
compiler/equiv_type.m:
compiler/error_util.m:
compiler/exprn_aux.m:
compiler/get_dependencies.m:
compiler/global_data.m:
compiler/layout_out.m:
compiler/liveness.m:
compiler/ll_pseudo_type_info.m:
compiler/llds.m:
compiler/llds_out_code_addr.m:
compiler/llds_out_data.m:
compiler/module_cmds.m:
compiler/module_qual.m:
compiler/module_qual.qualify_items.m:
compiler/opt_debug.m:
compiler/parse_class.m:
compiler/parse_goal.m:
compiler/parse_sym_name.m:
compiler/parse_type_defn.m:
compiler/rtti_out.m:
compiler/stack_layout.m:
compiler/trace_gen.m:
    Fix issues reported by --warn-inconsistent-pred-order-clauses
    for these modules.
2019-08-23 18:36:18 +10:00
Zoltan Somogyi
24b98fdafe Pack sub-word-sized ints and dummies in terms.
Previously, the only situation in which we could pack two or more arguments
of a term into a single word was when all those arguments are enums. This diff
changes that, so that the arguments can also be sub-word-sized integers
(signed or unsigned), or values of dummy types (which occupy zero bits).

This diff also records, for each argument of a function symbol, not just
whether, and if yes, how it is packed into a word, but also at *what offset*
that word is in the term's heap cell. It is more economical to compute this
once, when the representation of the type is being decided, than to compute
it over and over again when terms with that function symbol are being
constructed or deconstructed. However, for a transition period, we compute
these offsets at *both* times, to check the consistency of the new algorithm
for computing offsets that is run at "decide representation time" with
the old algorithms run at "generate code for a unification time".

compiler/du_type_layout.m:
    Make the changes described above: pack sub-word-sized integers and
    dummy values into argument words, if possible, and if the relevant
    new option allows it. These options are temporary. If we find no problems
    with the new packing algorithm in a few weeks, we should be able to
    delete them.

    Allow 64 bit ints and uints to be stored in unboxed in two words
    on 32 bit platforms, if the relevant new option allows it. Support
    for this is not yet complete, but it makes sense to implement the
    RTTI changes for both this change and one described in the above
    paragraph together.

    For each packed argument, record not just its width, its shift and
    the mask, but also the number of bits the argument takes. Previously,
    we computed this on demand from the mask, but there is no real need
    for that when simply storing this info is so cheap.

    For all arguments, packed or not, record its offset, relative to both
    the start of the arguments, and the start of the memory cell. (The two
    are different if the arguments are preceded by either a remote secondary
    tag, the typeinfos and/or typeclass_infos describing some existentially
    typed arguments, or both.) The reason for this is given at the top.

    Centralize the decision of the parameters of packing in one predicate.

    If the option --inform-suboptimal-packing is given, print an informational
    message whenever the code deciding type representations finds that
    reordering the arguments of a function symbol would allow it to pack
    the arguments of that function symbol into less space.

compiler/options.m:
    Add the option --allow-packing-ints which controls whether
    du_type_layout.m will attempt to pack {int,uint}{8,16,32} arguments
    alongside enum arguments.

    Add the option --allow-packing-dummies which controls whether
    du_type_layout.m will optimize away (in other words, represent in 0 bits)
    arguments of dummy types.

    Add the option --allow-double-word-ints which controls whether
    du_type_layout.m will store arguments of the types int64 and uint64
    unboxed in two words on 32 bit platforms, the way it currently stores
    double precision floats.

    All three those options are off by default, which preserves binary
    compatibility with existing code. However, the first two are ready
    to be switched on (the third is not).

    All three options are intended to be present in the compiler
    only until these changes are tested. Once we deem them sufficiently
    tested, I will modify the compiler to always do the packing they control,
    at which point we can delete these options. This is why they are not
    documented.

    Add the option --inform-suboptimal-packing, whose meaning is described
    above.

doc/user_guide.texi:
    Document --inform-suboptimal-packing.

compiler/prog_data.m:
    For each argument of a function symbol in a type definition, use
    a new type called arg_pos_width to record the extra information
    mentioned above in (offsets for all arguments, and number of bits
    for packed arguments).

    For each function symbol that has some existential type constraints,
    record the extra information mentioned for parse_type_defn.m below.

compiler/hlds_data.m:
    Include the position, as well as the width, in the representation
    of the arguments of function symbols.

    Previously, we used the integer 0 as a tag for dummies. Add a tag to
    represent dummy values, since this gives more information to any code
    that sees that tag.

compiler/ml_unify_gen.m:
compiler/unify_gen.m:
    Handle the packing of dummy values, and of sub-word-sized ints and uints.

    Compare the cell offset of each argument computed using existing
    algorithms here with the cell offset recorded in the argument's
    representation, and abort if they are different.

    In some cases, restructure code a bit to make it possible.
    For example, for tuples and closures, this means that instead of
    simply recording that each tuple argument or closure element
    is a full word, we must record its correct offset as well.

    Handle the new dummy_tag.

    Add prelim (not yet finished) support for double-word int64s/uint64s
    on 32 bit platforms.

    When packing the values of two or more variables (or constants) into a
    single word in a memory cell, optimize away operations that are no-ops,
    such as shifting anything by zero bits, shifting the constant zero
    by any number of bits, and ORing anything with zero. This makes the
    generated code easier to read. It is probably also faster for us
    to do it here than to write out a bigger expression, have the C compiler
    read in the bigger expression, and then later make the same optimization.

    In ml_unify_gen.m, avoid the unnecessary use of a list of the argument
    variables' types separate from the list of the argument variables
    themselves; just look up the type of each argument variable when it is
    processed.

compiler/add_special_pred.m:
    When creating special (unify and compare) predicates for tuples,
    include the offsets in the representation of their arguments.

    Delete an unused predicate.

compiler/llds.m:
    Add a new way to create an rval: a cast. We use it to implement
    the extraction of signed sub-word-sized integers from packed argument
    words in terms. Masking the right N bits out of the packed word
    leaves the other 32-N or 64-N bits as zeroes; a cast to int8_t,
    int16_t or int32_t will copy the sign bit to these bits.
    Likewise, when we pack signed int{8,16,32} values into words,
    we cast them to their unsigned versions to throw away any sign-extension
    bits in their original word-sized representations.

    No similar change is needed for the MLDS, since that already had
    a mechanism for casts.

compiler/mlds.m:
    Note a potential simplification in the MLDS.

compiler/builtin_lib_types.m:
    Add functions to return the Mercury representation of the int64
    and uint64 types.

compiler/foreign.m:
    Export a specialized version of an existing predicate, to allow
    ml_unify_gen.m to avoid the costs of the more general version.

compiler/hlds_out_module.m:
    Always print the representations of all arguments, since the
    inclusion of position information in those representation means that
    the representations of even all-full-word-argument terms are of potential
    interest when debugging term representations.

compiler/lco.m:
    Do not try to apply LCO to arguments of dummy types. (We could optimize
    them differently, by filling them in before they are "computed", but
    that is a separate optimization, which is of *very* low priority.)

compiler/liveness.m:
    Do not include variables of dummy types in resume points.

    The reason for this is that the code that establishes a resume point
    returns, for each such variable, a list of *lvals* where that variable
    can be found. The new code in unify_gen.m will optimize away assignments
    to values of dummy types, so there is *no* lval where they can be found.
    We could allocate one, but doing so would be a pessimization. Instead,
    we simply don't save and restore such values. When their value (which is
    always 0) is needed, we can create them out of thin air.

compiler/ml_global_data.m:
    Include the target language in the ml_global_data structure, to prevent
    some of its users having to look it up in the module_info.

    Add notes about the specializing the implementation of arrays of
    int64s/uint64s on 32 bit platforms.

compiler/check_typeclass.m:
compiler/ml_type_gen.m:
    Add sanity checks of the new precomputed fields of exist_constraints.

    Conform to the changes above.

compiler/mlds_to_c.m:
    Add prelim (not yet finished) support for double-word int64s/uint64s
    on 32 bit platforms.

    Add notes about possible optimizations.

compiler/parse_type_defn.m:
    When a function symbol in a type definition contains existential
    arguments, precompute and store the set of constrained and unconstrained
    type variables. The code in du_type_layout.m needs this information
    to compute the number of slots occupied by typeinfos and typeclass_infos
    in memory cells for this function symbol, and several other places
    in the compiler do too. It is easier and faster to compute this
    information just once, and this is the earliest time what that can be done.

compiler/type_ctor_info.m:
    Use the prerecorded information about existential types to simplify
    the code here

compiler/polymorphism.m:
    Add an XXX about possibly using the extra info we now record in
    exist_constraints to simplify the job of polymorphism.m.

compiler/pragma_c_gen.m:
compiler/var_locn.m:
    Create the values of dummy variables from scratch, if needed.

compiler/rtti.m:
    Replace a bool with a bespoke type.

compiler/rtti_out.m:
compiler/rtti_to_mlds.m:
    When generating RTTI information for the LLDS and MLDS backends
    respectively, record new kinds of arguments as needing special
    treatment. These are int64s and uint64s stored unboxed in two words
    on 32 bit platforms, {int,uint}{8,16,32} values packed into words,
    and dummy arguments. Each of these has a special code: its own negative
    negative value in the num_bits field of the argument.

    Generate slightly better formatted output.

compiler/type_util.m:
    Delete a predicate that isn't needed anymore.

compiler/opt_util.m:
    Delete a function that hasn't been needed for a while.

    Conform to the changes above.

compiler/arg_pack.m:
compiler/bytecode_gen.m:
compiler/call_gen.m:
compiler/code_util.m:
compiler/ctgc.selector.m:
compiler/dupelim.m:
compiler/dupproc.m:
compiler/equiv_type.m:
compiler/equiv_type_hlds.m:
compiler/erl_code_gen.m:
compiler/erl_rtti.m:
compiler/export.m:
compiler/exprn_aux.m:
compiler/global_data.m:
compiler/jumpopt.m:
compiler/livemap.m:
compiler/llds_out_data.m:
compiler/middle_rec.m:
compiler/ml_closure_gen.m:
compiler/ml_switch_gen.m:
compiler/ml_top_gen.m:
compiler/module_qual.qualify_items.m:
compiler/opt_debug.m:
compiler/parse_tree_out.m:
compiler/peephole.m:
compiler/recompilation.usage.m:
compiler/resolve_unify_functor.m:
compiler/stack_layout.m:
compiler/structure_reuse.direct.choose_reuse.m:
compiler/switch_util.m:
compiler/typecheck.m:
compiler/unify_proc.m:
compiler/unused_imports.m:
compiler/xml_documentation.m:
    Conform to the changes above.

compiler/llds_out_util.m:
    Add a comment.

compiler/ml_code_util.m:
    Factor out some common code.

runtime/mercury_type_info.h:
    Allocate special values of the MR_arg_bits field of the MR_DuArgLocn type
    to designate arguments as two word int64/uint64s, as sub-word-sized
    arguments of types {int,uint}{8,16,32}, or as arguments of dummy types.
    (We already had a special value for two word float arguments.)

    Document the list of places that know about this code, so that they
    can be updated if and when it changes.

library/construct.m:
    Handle the construction of terms with two-word int64/uint64 arguments,
    with packed {int,uint}{8,16,32} arguments, and with dummy arguments.

    Factor out the code common to the sectag-present and sectag-absent cases,
    to make it possible to do the above in just *one* place.

library/store.m:
    Add an XXX to a place that I don't think handles two word arguments
    correctly. (I think this is an old bug.)

runtime/mercury_deconstruct.c:
    Handle the deconstruction of terms with two-word int64/uint64 arguments,
    with packed {int,uint}{8,16,32} arguments, and with dummy arguments.

runtime/mercury_deep_copy_body.h:
    Handle the copying of terms with two-word int64/uint64 arguments,
    with packed {int,uint}{8,16,32} arguments, and with dummy arguments.

    Give a macro a more descriptive name.

runtime/mercury_type_info.c:
    Handle taking the size of terms with two-word int64/uint64 arguments,
    with packed {int,uint}{8,16,32} arguments, and with dummy arguments.

runtime/mercury.h:
    Put related definitions next to each other.

runtime/mercury_deconstruct.h:
runtime/mercury_ml_expand_body.h:
    Fix indentation.

tests/hard_coded/construct_test.{m,exp}:
    Add to this test case a test of the construction, via the library's
    construct.m module, of terms containing packed sub-word-sized integers,
    and packed dummies.

tests/hard_coded/deconstruct_arg.{m,exp}:
    Convert the source code of this test case to state variable notation,
    and update the line number references (in the names of predicates created
    from lambda expressions) accordingly.

tests/hard_coded/uint64_ground_term.{m,exp}:
    A new test case to check that uint64 values too large to be int64 values
    can be stored in static structures.

tests/hard_coded/Mmakefile:
    Enable the new test case.
2018-05-05 13:22:19 +02:00
Zoltan Somogyi
15aa457e12 Delete $module arg from calls to unexpected. 2018-04-07 18:25:43 +10:00
Zoltan Somogyi
cfcfde1db7 Simplify the representation of modes of unifications.
Unifications (x = y) have long had two descriptions of their modes.
One is the unify_mode, which used to look like this:
    (initx -> finalx) - (inity -> finaly)
and other is the uni_mode, which used to look like this:
    (initx - inity) -> (finalx - finaly)
Each unification had one unify_mode, and each unification that includes
a function symbol had one uni_mode per argument of that function symbol.

The two forms of mode information looked similar enough to be easily
confusable, but were subtly different. As it turns out, there was no
particular reason for the difference, so this diff eliminates the
uni_mode type, and the difference along with it.

What rationale there was for the uni_mode type was that the two modes
it represented (one for each side of the unification) both had their
initial and final insts directly available. This is not true for modes
in general: a value of the mer_mode type could have the form
"InitInst -> FinalInst" (which this diff renames "from_to_mode(InitInst,
FinalInst)", but could also be a "user_defined_inst(...)", which required
a table lookup to turn it into an initial/final pair of insts. This matters,
because almost all code that processes the modes of unifications
works with the initial and final insts.

This diff therefore creates a new type, from_to_insts, which represents
mode information only in the form of terms such as "from_to_insts(InitInst,
FinalInst)", and makes a unify_mode take two values of this type, not mer_mode,
as arguments.

As discussed on m-rev, this diff also renames the old, deceptively named
"arg_mode" type: its new name is "top_functor_mode".

compiler/prog_data.m:
compiler/hlds_goal.m:
    As mentioned above, avoid using "->" as a function symbol, and replace
    both -> and - with bespoke function symbols.

compiler/mode_util.m:
    Add some utility predicates and functions on the new types, and
    delete the old utility routines that operated on uni_modes.

    Code that uses the new functions and predicates should have a higher level
    of abstraction than the code that used to do the same job "manually".

compiler/*.m:
    Conform to the changes above, using the new utility predicates and
    functions where relevant. In several cases, this required fixing
    confusion of the kind described at the top. In all but one case,
    the confusion affected only variable names, but in one case,
    deconstruct_functor in make_goal.m, it caused a bug. The bug has
    had no effect up till now because deconstruct_functor is called
    only from three places: try_expand.m, stm_expand.m, and untupling.m.
    The incorrect mode (which was the nonsensical ground -> free)
    generated by the code of try_expand.m itself was discarded and
    overwritten when try_expand.m invoked the modechecker. (I don't
    know whether this bugfix makes that invocation redundant or not.)
    The other two modules, stm_expand.m and untupling.m, may do something
    similar, but in any case, they don't yet work for other reasons.
    (A bootcheck with --untupling causes a compiler abort when compiling
    deep_profiler/query.m in stage 2 both without and with this fix.)

    Delete no-longer-needed imports of the pair module (and of some other
    modules).

    Put the arguments of some predicates into a more logical order.

    In bytecode_gen.m, replace clauses with disjunctions, and delete the
    arguments that this step has revealed to be unused.
2016-05-19 10:43:24 +10:00
Zoltan Somogyi
5de235065d Fix too-long lines. 2015-11-16 00:09:26 +11:00
Zoltan Somogyi
bf324f88cc Fix Mantis bug 50.
compiler/liveness.m:
    The bug was a violation of an invariant required by delay_death_proc_body.
    Document the requirement that this invariant places on cse_detection.m,
    the requirement whose non-fulfillment caused the bug.

compiler/cse_detection.m:
    When hoisting a deconstruction unification and creating new variables
    for its arguments, if any of the arguments were named variables holding
    type_infos, typeclass_infos or their components, then give a name
    to the variable holding the corresponding argument as well. This fixes
    the bug by fixing the violation of the above invariant. Add a pointer
    to the invariant in liveness.m.

    Document the reason why another change that looks like a potential fix
    wouldn't actually work.

    Give some predicates better names and argument orders.

    Update the module qualifier (from : to .) in an example. We haven't used
    : in a LONG time.

compiler/continuation_info.m:
    Simplify the code where the bug originally caused the compiler to crash.
    (This code was not actually in error.)

compiler/simplify_goal_conj.m:
    Fix a small performance bug I noted while hunting the bug. When the
    excess_assign optimization replaced all occurrences of a variable,
    it delete the variable from the varset, but not the vartypes,
    leaving lookups on it slower than necessary.

    Record the reason why do not choose to fix a potential performance bug
    that to the best of my knowledge, we haven't actually seen yet in the wild.

compiler/hlds_goal.m:
    Define a type as a shorter and more meaningful synonym for a particular
    type used in a predicate (incremental_rename_vars_in_goal) that I thought
    would have been useful to implement the change to cse_detection.m
    that turned out to be NOT a good fix.

compiler/state_var.m:
    Use the new type synonym.

tests/valid/bug50_full.m:
tests/valid/bug50.m:
    Two versions of the Mantis test case; the original version (slightly
    cleaned up), and the minimal version I actually debugged. The latter
    has a detailed description of the bug.

tests/valid/Mercury.options:
tests/valid/Mmakefile:
    Enable the new test cases.
2015-11-15 23:13:02 +11:00
Zoltan Somogyi
cb4158fa71 Make initial_liveness a bit faster.
compiler/liveness.m:
    Instead of looking up the pred_info for the procedure being processed,
    get our caller to give it to us.

    Put the arguments of some predicates in a more logical order.

compiler/stack_alloc.m:
compiler/stack_opt.m:
compiler/store_alloc.m:
compiler/tupling.m:
    Pass the pred_info instead of a pred_id to initial_liveness. In all
    these callers, the pred_info was already available.
2015-11-15 16:52:14 +11:00
Zoltan Somogyi
cc9912faa8 Don't import anything in packages.
Packages are modules whose only job is to serve as a container for submodules.
Modules like top_level.m, hlds.m, parse_tree.m and ll_backend.m are packages
in this (informal) sense.

Besides the include_module declarations for their submodules, most of the
packages in the compiler used to import some modules, mostly other packages
whose component modules their submodules may need. For example, ll_backend.m
used to import parse_tree.m. This meant that modules in the ll_backend package
did not have to import parse_tree.m before importing modules in the parse_tree
package.

However, this had a price. When we add a new module to the parse_tree package,
parse_tree.int would change, and this would require the recompilation of ALL
the modules in the ll_backend package, even the ones that did NOT import ANY
of the modules in the parse_tree package.

This happened even at one remove. Pretty much all modules in every one
of the backend have to import one or more modules in the hlds package,
and they therefore have import hlds.m. Since hlds.m imported transform_hlds.m,
any addition of a new middle pass to the transform_hlds package required
the recompilation of all backend modules, even in the usual case of the two
having nothing to do with each other.

This diff removes all import_module declarations from the packages,
and replaces them with import_module declarations in the modules that need
them. This includes only a SUBSET of their child modules and of the non-child
modules that import them.
2015-11-13 15:03:20 +11:00
Zoltan Somogyi
04daa04751 Delete some unused imports. 2015-09-14 04:35:40 +10:00
Zoltan Somogyi
f2acc09ce6 Speed up operations on special pred maps.
The special_pred_map type used to have a pair of a special_pred_id and a
type_ctor as its key. This meant that we compared the special_pred_ids
on every level of a lookup. Since there are only four special_pred_ids
(for unify, index, compare and solver init predicates), this is wasteful.

Replace the special_pred_map type with the special_pred_maps type,
which is a tuple of four maps, one for each special_pred_id, in which
the keys are just type_ctors. Looking at the special_pred_id just once
should speed up operations.

compiler/special_pred.m:
    As above.

    Provide search and lookup predicates on the special_pred_maps type,
    since it is no longer just a simple map.search or map.lookup.

    Put the definitions of predicates into the same order as their
    declarations.

compiler/hlds_pred.m:
    Remove an unnecessary cell from the representation of origin_special_pred.

compiler/add_special_pred.m:
    Conform to the above changes.

    Use map.det_insert instead of map.set when adding new entries
    to the special_pred_maps.

compiler/deep_profiling.m:
compiler/det_report.m:
compiler/elds_to_erlang.m:
compiler/exception_analysis.m:
compiler/float_regs.m:
compiler/hlds_error_util.m:
compiler/hlds_module.m:
compiler/hlds_out_pred.m:
compiler/hlds_out_util.m:
compiler/intermod.m:
compiler/layout_out.m:
compiler/liveness.m:
compiler/ml_code_util.m:
compiler/mode_errors.m:
compiler/oisu_check.m:
compiler/polymorphism.m:
compiler/post_term_analysis.m:
compiler/post_typecheck.m:
compiler/proc_gen.m:
compiler/proc_label.m:
compiler/simplify_goal_unify.m:
compiler/smm_common.m:
compiler/structure_reuse.direct.m:
compiler/structure_reuse.indirect.m:
compiler/structure_sharing.domain.m:
compiler/term_constr_initial.m:
compiler/termination.m:
compiler/trace_params.m:
compiler/type_constraints.m:
compiler/type_ctor_info.m:
compiler/typecheck.m:
compiler/unify_gen.m:
compiler/unify_proc.m:
compiler/unused_args.m:
    Conform to the above changes.
2015-09-12 12:04:18 +10:00
Zoltan Somogyi
bbb2535eb5 Break up mercury_to_mercury.m.
With almost 6000 lines, mercury_to_mercury.m was one of the biggest modules
of compiler, but it was far from cohesive. This diff carves seven new modules
out of it, each of which is much more cohesive. The stuff remaining in
mercury_to_mercury.m is still not as cohesive as one would like, but it is
now small enough that moving its individually-cohesive parts into modules
of their own would be overkill.

Three consequences of the old mercury_to_mercury.m's lack of cohesion
were that

- the order of predicate declarations often did not match the order of
  their implementation;
- related predicates were not grouped together;
- even when they were grouped together, the order of those groups
  was often random.

This diff fixes all three of these problems for all eight successor modules
of mercury_to_mercury.m: the seven new modules, and the new
mercury_to_mercury.m itself.

In some cases, this diff adds or improves the documentation of the predicates
in mercury_to_mercury.m's successor modules. In some other cases, it just
documents the lack of documentation :-(. In yet other cases, it removes
"documentation" that says nothing that isn't obvious from the predicate's name.

There are some algorithmic changes, but they are all trivial.

compiler/parse_tree_out.m:
    New module containing the code to print out the top levels of parse trees,
    including most sorts of items.

compiler/parse_tree_out_clause.m:
    New module containing the code to print out clauses and goals.

compiler/parse_tree_out_pragma.m:
    New module containing the code to print out pragmas.

compiler/parse_tree_out_pred_decl.m:
    New module containing the code to print out predicate, function and
    mode declarations. It is separate from parse_tree_out.m because a
    significant number of compiler modules need only its functionality,
    and not parse_tree_out.m's functionality.

compiler/parse_tree_out_inst.m:
    New module containing the code to print out insts and modes.

compiler/parse_tree_out_term.m:
    New module containing the code to print out variables and terms.

compiler/parse_tree_out_info.m:
    New module containing the infrastructure of both mercury_to_mercury.m
    and the other new modules.

compiler/parse_tree.m:
    Include the new modules.

compiler/notes/compiler_design.html:
    Document the new modules.

compiler/Mercury.options:
    Transfer an option from mercury_to_mercury.m to the successor module
    that needs it.

compiler/*.m:
    Import one of the new modules either as well as, or instead of,
    mercury_to_mercury.m. In most cases, we need to import only one
    or two of mercury_to_mercury.m's successor modules; nowhere do we
    need to import all eight.

    Clean up some code in termination.m around a call to one of the
    new modules.

tools/speedtest:
    Replace mercury_to_mercury.m on the list of the ten largest modules
    of the compiler.
2015-09-06 21:01:11 +10:00
Zoltan Somogyi
c34f6dd4e8 Let the compiler bootstrap in decldebug grades again.
The big diff that replaced the item list with proper parse trees included code
that the compiler couldn't handle in decldebug grades, aborting with a message
about liveness mismatch between different switch arms. The problem occurred
when compiling this code in generate_missing_start_section_warning_int,
which is one arm of a switch on !.MissingStartSectionWarning:

    !.MissingStartSectionWarning =
        have_not_given_missing_section_start_warning,
    !:MissingStartSectionWarning =
        have_given_missing_section_start_warning,
    Pieces = [invis_order_default_start(1), ...],
    _Spec = error_spec(severity_error, phase_term_to_parse_tree,
        [simple_msg(Context, [always(Pieces)])])

The problem was liveness.m's handling of the from_ground_term_construct
scope that is generated for the assigmnet of the ground term to Pieces.

compiler/liveness.m:
    During the first pass through the procedure body, the liveness pass,
    replace with the empty conjunction any from_ground_term_construct scopes
    that construct terms to assign to dead variables. This prevents the
    second pass, the deadness pass, from including the dead variable
    (Pieces in the above example, after the assignment to _Spec was
    optimized away by earlier passes) in the set of variables that
    have been seen, since obviously, they won't be seen in the other arms.
    This inclusion was the cause of the assertion failure that led to
    the compiler abort.

    Improve the existing debugging infrastructure to help find bugs like this,
    by printing out what the selected procedure's body looks like before
    as well as after the initial requantification.

compiler/quantification.m:
    Replace from_ground_term_construct scopes whose ground term is assigned
    to a dead variable with empty conjunctions, so that the compiler passes
    between the first quantification after mode checking and the liveness
    pass also see a smaller HLDS.

    Implement an unrelated improvement whose possibility I discovered when
    investigating why a version of the test case *without* the from_ground_term
    scope wasn't getting the abort. When processing unifications, build up the
    set of variables in the unification directly, not by recording a bunch
    of maybe(somethings)s and then processing the somethings, if they existed,
    later. This yields code that is shorter, simpler *and* faster.

tests/valid/liveness_disagree.m:
    A new test case for this bug. It is a cut-down version of
    generate_missing_start_section_warning_int.

tests/valid/Mmakefile:
tests/valid/Mercury.options:
    Enable the new test case, and try to compile it in a declarative debugging
    grade.

compiler/assertion.m:
compiler/deep_profiling.m:
compiler/lookup_switch.m:
compiler/par_loop_control.m:
    Add module qualifications in several places. I found the need for these
    when I temporarily redefined the set_of_var type to use sets instead of
    sparse_bitsets, to make debugging the bug in liveness.m easier; without
    them, I got errors about excessive overloading.

    Do some other cleanups as well.

tests/debugger/all_solutions.exp4:
tests/debugger/exception_cmd.exp3:
tests/debugger/loopcheck.exp3:
tests/debugger/uci_index.exp2:
tests/declarative_debugger/Mmakefile:
tests/declarative_debugger/builtin_call_rep.exp:
tests/declarative_debugger/catch_retry.exp:
tests/declarative_debugger/condition_bug.exp:
tests/declarative_debugger/find_origin.exp3:
tests/declarative_debugger/lpe_example.exp3:
tests/declarative_debugger/priv_builtin_bug.exp:
tests/declarative_debugger/solns.exp3:
tests/declarative_debugger/sort.exp:
tests/declarative_debugger/track_through_catch.exp:
tests/declarative_debugger/typed_unify.exp:
    Update all these expected outputs for the changes in line numbers
    caused by my cleanups of the test cases early in 2015.

    For the declarative_debugger/{condition_bug,sort} test cases, also
    update them for the change to print the types and values of foreign types.

tests/hard_coded/type_qual.{m,exp}:
    This test case failed for an earlier version of this diff, so add some
    context to its outputs, to make such failures easier to debug.
    To make *that* easier, bring it to date in programming style.
2015-08-29 13:07:01 +10:00
Zoltan Somogyi
e796f94866 Convert (C->T;E) to (if C then T else E). 2015-08-28 21:31:52 +10:00
Zoltan Somogyi
62ec97d443 Report imports shadowed by other imports.
If a module has two or more import_module or use_module declarations
for the same module, (typically, but not always, one being in its interface
and one in its implementation), generate an informational message about
each redundant declaration if --warn-unused-imports is enabled.

compiler/hlds_module.m:
    We used to record the set of imported/used modules, and the set of
    modules imported/used in the interface of the current module. However,
    these sets

    - did not record the distinction between imports and uses;
    - did not allow distinction between single and multiple imports/uses;
    - did not record the locations of the imports/uses.

    The first distinction was needed only by module_qual.m, which *did*
    pay attention to it; the other two were not needed at all.

    To generate messages for imports/uses shadowing other imports/uses,
    we need all three, so change the data structure storing such information
    for *direct* imports to one that records all three of the above kinds
    of information. (For imports made by read-in interface and optimization
    files, the old set of modules approach is fine, and this diff leaves
    the set of thus *indirectly* imported module names alone.)

compiler/unused_imports.m:
    Use the extra information now available to generate a
    severity_informational message about any import or use that is made
    redundant by an earlier, more general import or use.

    Fix two bugs in the code that generated warnings for just plain unused
    modules.

    (1) It did not consider that a use of the builtin type char justified
    an import of char.m, but without that import, the type is not visible.

    (2) It scanned cons_ids in goals in procedure bodies, but did not scan
    cons_ids that have been put into the const_struct_db. (I did not update
    the code here when I added the const_struct_db.)

    Also, add a (hopefully temporary) workaround for a bug in
    make_hlds_passes.m, which is noted below.

    However, there are at least three problems that prevent us from enabling
    --warn-unused-imports by default.

    (1) In some places, the import of a module is used only by clauses for
    a predicate that also has foreign procs. When compiled in a grade that
    selects one of those foreign_procs as the implementation of the predicate,
    the clauses are discarded *without* being added to the HLDS at all.
    This leads unused_imports.m to generate an uncalled-for warning in such
    cases. To fix this, we would need to preserve the Mercury clauses for
    *all* predicates, even those with foreign procs, and do all the semantic
    checks on them before throwing them away. (I tried to do this once, and
    failed, but the task should be easier after the item list change.)

    (2) We have two pieces of code to generate import warnings. The one in
    unused_imports.m operates on the HLDS after type and mode checking,
    while module_qual.m operates on the parse tree before the creation of
    the HLDS. The former is more powerful, since it knows e.g. what types and
    modes are used in the bodies of predicates, and hence can generate warnings
    about an import being unused *anywhere* in a module, as opposed to just
    unused in its interface.

    If --warn-unused-imports is enabled, we will get two separate set of
    reports about an interface import being unused in the interface,
    *unless* we get a type or mode error, in which case unused_imports.m
    won't be invoked. But in case we do get such errors, we don't want to
    throw away the warnings from module_qual.m. We could store them and
    throw them away only after we know we won't need them, or just get
    the two modules to generate identical error_specs for each warning,
    so that the sort_and_remove_dups of the error specs will do the
    throwing away for us for free, if we get that far.

    (3) The valid/bug100.m test case was added as a regression test for a bug
    that was fixed in module_qual.m. However the bug is still present in
    unused_imports.m.

compiler/make_hlds_passes.m:
    Give hlds_module.m the extra information it now needs for each item_avail.

    Add an XXX for a bug that cannot be fixed right now: the setting of
    the status of abstract instances to abstract_imported. (The "abstract"
    part is correct; the "imported" part may not be.)

compiler/intermod.m:
compiler/try_expand.m:
compiler/xml_documentation.m:
    Conform to the change in hlds_module.m.

compiler/module_qual.m:
    Update the documentation of the relationship of this module
    with unused_imports.m.

compiler/hlds_data.m:
    Document a problem with the status of instance definitions.

compiler/hlds_out_module.m:
    Update the code that prints out the module_info to conform to the change
    to hlds_module.m.

    Print status information about instances, which was needed to diagnose
    one of the bugs in unused_imports.m. Format the output for instances
    nicer.

compiler/prog_item.m:
    Add a convenience predicate.

compiler/prog_data.m:
    Remove a type synonym that makes things harder to understand, not easier.

compiler/modules.m:
    Delete an XXX that asks for the feature this diff implements.
    Add another XXX about how that feature could be improved.

compiler/Mercury.options.m:
    Add some more modules to the list of modules on which the compiler
    should be invoked with --no-warn-unused-imports.

compiler/*.m:
library/*.m:
mdbcomp/*.m:
browser/*.m:
deep_profiler/*.m:
mfilterjavac/*.m:
    Delete unneeded imports. Many of these shadow other imports, and some
    are just plain unneeded, as shown by --warn-unused-imports. In a few
    modules, there were a *lot* of unneeded imports, but most had just
    one or two.

    In a few cases, removing an import from a module, because it *itself*
    does not need it, required adding that same import to those of its
    submodules which *do* need it.

    In a few cases, conform to other changes above.

tests/invalid/Mercury.options:
    Test the generation of messages about import shadowing on the existing
    import_in_parent.m test case (although it was also tested very thoroughly
    when giving me the information needed for the deletion of all the
    unneeded imports above).

tests/*/*.{m,*exp}:
    Delete unneeded imports, and update any expected error messages
    to expect the now-smaller line numbers.
2015-08-25 00:38:49 +10:00
Zoltan Somogyi
1aee1b8ade Don't put variable names in clauses in .opt files.
After this diff, a change in the source file that affects only variable names
won't cause the recompilation of the other modules that use the changed
module's .opt file. (I got a bunch of such unnecessary recompilations when
giving new names to many of varset.m's variables.)

compiler/prog_data.m:
    Add a new type named var_name_print to replace the boolean that used
    to specify whether we wanted to print the variable number as a suffix
    after the variable name. This new type allows us to specify not just that
    e.g. a variable numbered 10 and named Example should be printed as
    Example or as Example_10, but also as V_10.

compiler/intermod.m:
    Use this capability to print variables in only the V_N form when
    putting clauses in .opt files. After this diff, a change in the source
    file that affects only variable names won't cause the recompilation
    of the other modules that use the change module's .opt file.

    Convert (C->T;E) into (if C then T else E).

compiler/mercury_to_mercury.m:
compiler/hlds_out_goal.m:
compiler/hlds_out_mode.m:
compiler/hlds_out_module.m:
compiler/hlds_out_pred.m:
compiler/hlds_out_util.m:
    Generalize mercury_var_to_string, and the predicates that call it
    directly or indirectly, to take an argument of the var_name_print type
    instead of the old AppendVarNum boolean.

    Put the argument lists of the affected predicates in a better order,
    with related parameters being next to each other, and moving more global
    parameters before more local parameters.

    Add versions of mercury_var_to_string to mercury_vars_to_string
    that assume the print_name_only value for the var_name_print parameter,
    since this is typically what we want when we generate error messages.

    In hlds_out_pred.m, add another type, write_which_modes, to replace
    another boolean parameter.

compiler/add_foreign_proc.m:
compiler/add_pragma_type_spec.m:
compiler/check_typeclass.m:
compiler/code_loc_dep.m:
compiler/dep_par_conj.m:
compiler/det_analysis.m:
compiler/det_report.m:
compiler/field_access.m:
compiler/format_call.m:
compiler/goal_expr_to_goal.m:
compiler/hlds_desc.m:
compiler/layout_out.m:
compiler/liveness.m:
compiler/llds_out_instr.m:
compiler/make_hlds_warn.m:
compiler/mercury_to_mercury.m:
compiler/mode_debug.m:
compiler/mode_errors.m:
compiler/pd_debug.m:
compiler/post_typecheck.m:
compiler/prog_ctgc.m:
compiler/prog_io_item.m:
compiler/prog_io_mutable.m:
compiler/prog_io_type_defn.m:
compiler/prog_io_typeclass.m:
compiler/prog_util.m:
compiler/purity.m:
compiler/push_goals_together.m:
compiler/rbmm.live_variable_analysis.m:
compiler/recompilation.usage.m:
compiler/recompilation.version.m:
compiler/saved_vars.m:
compiler/stack_opt.m:
compiler/structure_reuse.indirect.m:
compiler/type_assign.m:
compiler/type_constraints.m:
compiler/typecheck.m:
compiler/typecheck_errors.m:
compiler/unneeded_code.m:
compiler/unused_args.m:
    Conform to the above changes.
2015-08-22 14:42:28 +10:00
Zoltan Somogyi
04dec8c205 Carve vartypes.m, prog_detism.m and prog_rename.m out of prog_data.m.
Besides defining most of the types representing the smaller parts of
parse trees (parts smaller than items), prog_data.m also has many utility
predicates that operate on values of these types. Carve the three substantial
clusters of predicates out of prog_data.m, and move them into their own
modules, which are each imported by fewer modules than prog_data.m itself.

compiler/vartypes.m:
    New module containing the vartypes type and the predicates that operate
    on it. The new module has *much* better cohesion than the old prog_data.m.

    The vartypes type does not appear in any parse tree; it is used only
    in the HLDS. So make vartypes.m part of the hlds.m package, not
    parse_tree.m.

    Move three predicates that perform renamings and substitutions on vartypes
    here from prog_type_subst.m, since the latter is part of the parse_tree.m
    package, and thus doesn't have access to hlds.vartypes. Make private
    the service predicate that these three moved predicates used to rely on,
    since it has no other callers.

compiler/prog_detism.m:
    New module containing utility predicates that operate on determinisms
    and determinism components.

compiler/prog_rename.m:
    New module containing utility predicates that rename variables in
    various data structures.

compiler/prog_data.m:
    Remove the stuff now in the three new modules.

compiler/prog_type_subst.m:
    Remove the three predicates now in vartypes.m.

compiler/mercury_to_mercury.m:
    Delete an unneded predicate, which was the only part of this module
    that referred to vartypes.

compiler/prog_type.m:
compiler/builtin_lib_types.m:
compiler/type_util.m:
    Move some utility predicates that refer to vartypes from prog_type.m
    and builtin_lib_types.m (both part of parse_tree.m) to type_util.m
    (part of check_hlds.m).

compiler/parse_tree.m:
compiler/hlds.m:
compiler/notes/compiler_design.html:
    Mention the new modules.

compiler/accumulator.m:
compiler/add_class.m:
compiler/add_clause.m:
compiler/add_foreign_proc.m:
compiler/add_heap_ops.m:
compiler/add_pragma_type_spec.m:
compiler/add_pred.m:
compiler/add_trail_ops.m:
compiler/arg_info.m:
compiler/bytecode_gen.m:
compiler/call_gen.m:
compiler/clause_to_proc.m:
compiler/closure_analysis.m:
compiler/code_info.m:
compiler/code_loc_dep.m:
compiler/common.m:
compiler/complexity.m:
compiler/const_prop.m:
compiler/constraint.m:
compiler/continuation_info.m:
compiler/coverage_profiling.m:
compiler/cse_detection.m:
compiler/ctgc.datastruct.m:
compiler/ctgc.util.m:
compiler/deep_profiling.m:
compiler/deforest.m:
compiler/delay_construct.m:
compiler/delay_partial_inst.m:
compiler/dep_par_conj.m:
compiler/det_analysis.m:
compiler/det_report.m:
compiler/det_util.m:
compiler/disj_gen.m:
compiler/equiv_type_hlds.m:
compiler/erl_call_gen.m:
compiler/erl_code_gen.m:
compiler/erl_code_util.m:
compiler/exception_analysis.m:
compiler/float_regs.m:
compiler/follow_code.m:
compiler/follow_vars.m:
compiler/format_call.m:
compiler/goal_expr_to_goal.m:
compiler/goal_path.m:
compiler/goal_store.m:
compiler/goal_util.m:
compiler/headvar_names.m:
compiler/hhf.m:
compiler/higher_order.m:
compiler/hlds_clauses.m:
compiler/hlds_goal.m:
compiler/hlds_llds.m:
compiler/hlds_out_goal.m:
compiler/hlds_out_module.m:
compiler/hlds_out_pred.m:
compiler/hlds_pred.m:
compiler/hlds_rtti.m:
compiler/inlining.m:
compiler/inst_util.m:
compiler/instmap.m:
compiler/intermod.m:
compiler/interval.m:
compiler/lambda.m:
compiler/lco.m:
compiler/live_vars.m:
compiler/liveness.m:
compiler/lookup_switch.m:
compiler/make_goal.m:
compiler/mark_tail_calls.m:
compiler/ml_accurate_gc.m:
compiler/ml_code_gen.m:
compiler/ml_code_util.m:
compiler/ml_disj_gen.m:
compiler/ml_gen_info.m:
compiler/ml_lookup_switch.m:
compiler/ml_proc_gen.m:
compiler/ml_unify_gen.m:
compiler/mode_constraints.m:
compiler/mode_info.m:
compiler/mode_util.m:
compiler/modecheck_call.m:
compiler/modecheck_conj.m:
compiler/modecheck_goal.m:
compiler/modecheck_unify.m:
compiler/modecheck_util.m:
compiler/modes.m:
compiler/par_loop_control.m:
compiler/pd_info.m:
compiler/pd_util.m:
compiler/polymorphism.m:
compiler/post_typecheck.m:
compiler/prog_rep.m:
compiler/prop_mode_constraints.m:
compiler/purity.m:
compiler/qual_info.m:
compiler/quantification.m:
compiler/rbmm.points_to_graph.m:
compiler/rbmm.points_to_info.m:
compiler/rbmm.region_liveness_info.m:
compiler/rbmm.region_transformation.m:
compiler/saved_vars.m:
compiler/set_of_var.m:
compiler/simplify_goal_call.m:
compiler/simplify_goal_conj.m:
compiler/simplify_goal_disj.m:
compiler/simplify_goal_ite.m:
compiler/simplify_goal_scope.m:
compiler/simplify_goal_switch.m:
compiler/simplify_goal_unify.m:
compiler/simplify_info.m:
compiler/simplify_proc.m:
compiler/size_prof.m:
compiler/ssdebug.m:
compiler/stack_alloc.m:
compiler/stack_layout.m:
compiler/stack_opt.m:
compiler/stm_expand.m:
compiler/store_alloc.m:
compiler/structure_reuse.analysis.m:
compiler/structure_reuse.direct.choose_reuse.m:
compiler/structure_reuse.direct.detect_garbage.m:
compiler/structure_reuse.indirect.m:
compiler/structure_reuse.lbu.m:
compiler/structure_reuse.lfu.m:
compiler/structure_sharing.analysis.m:
compiler/structure_sharing.domain.m:
compiler/switch_detection.m:
compiler/table_gen.m:
compiler/tabling_analysis.m:
compiler/term_constr_build.m:
compiler/term_constr_initial.m:
compiler/term_constr_util.m:
compiler/term_pass1.m:
compiler/term_traversal.m:
compiler/term_util.m:
compiler/trace_gen.m:
compiler/trailing_analysis.m:
compiler/try_expand.m:
compiler/tupling.m:
compiler/type_assign.m:
compiler/type_constraints.m:
compiler/typecheck.m:
compiler/typecheck_errors.m:
compiler/unify_gen.m:
compiler/unify_proc.m:
compiler/unique_modes.m:
compiler/unneeded_code.m:
compiler/untupling.m:
compiler/unused_args.m:
compiler/var_locn.m:
    Conform to the above changes, mostly by importing some of the
    three new modules as well as, or instead of, prog_data.m.
2015-08-09 19:02:12 +10:00
Zoltan Somogyi
05f5ec7d41 Fix a bug that put $typed_insts in .opt files.
compiler/mercury_to_mercury.m:
    Make the predicates that output insts take a parameter that says whether
    we are trying to print valid Mercury code (in which case we strip any
    $typed_inst wrappers around other insts), or as-informative-as-possible
    representations of insts for debugging, in which case we do NOT strip
    those wrappers. When invoked on insts that CANNOT be printed as valid
    Mercury even though valid Mercury is being requested, abort.

    Rationalize the argument order of the involved predicates.

    Move the output_lang type here from hlds_out_util.m to make the above
    possible. Change the flag that governs whether item names are qualified
    or not from a bool to a bespoke enum type. Fix a bug involving that bool.

compiler/hlds_out_mode.m:
    This module also has a predicate that output insts, though it already had
    a valid mercury/debug output flag. If it is asked to print valid Mercury,
    make it strip $typed_inst wrappers, and abort on insts that cannot be
    printed as valid Mercury.

    A better fix would be to eliminate this predicate, and other predicates
    in this module that also duplicate predicates in mercury_to_mercury.m,
    after generalizing the latter as needed, but that would take more time.

compiler/add_clause.m:
compiler/add_mutable_aux_preds.m:
compiler/dep_par_conj.m:
compiler/dependency_graph.m:
compiler/format_call.m:
compiler/goal_expr_to_goal.m:
compiler/hlds_error_util.m:
compiler/hlds_out_goal.m:
compiler/hlds_out_module.m:
compiler/hlds_out_pred.m:
compiler/hlds_out_util.m:
compiler/intermod.m:
compiler/liveness.m:
compiler/make_hlds_error.m:
compiler/mercury_to_mercury.m:
compiler/mode_errors.m:
compiler/passes_aux.m:
compiler/pd_debug.m:
compiler/push_goals_together.m:
compiler/saved_vars.m:
compiler/stack_opt.m:
compiler/structure_reuse.analysis.m:
compiler/structure_sharing.analysis.m:
compiler/term_constr_main.m:
compiler/termination.m:
compiler/unneeded_code.m:
    Conform to the above.

compiler/mode_constraint_robdd.m:
compiler/mode_constraints.m:
    Fix an unrelated problem that ALSO prevented a bootcheck with -O5
    --intermodule-optimization, which is that with these options, several
    predicates in both these modules accumulated enough type ambiguities
    for the type checker to throw up its hands in despair.

    The type checker should NOT be influenced by the additional types, data
    constructors, field names, functions and predicates added by these options
    to their respective tables, but it is. Fixing that bug is future work.
    For now, just reduce the ambiguities to the allowable level, mostly
    by adding module qualifiers, and by converting some function calls to
    predicate calls. (Function calls introduce ambiguities, since the
    typechecker thinks they may be partially applied predicate calls.)
2015-04-02 12:09:42 +11:00
Zoltan Somogyi
89628ae791 More speedups of inst handling code.
On tools/speedtest -l -m, my tests show a speedup of about 2%, but
on Dirk's stress test module, for which the compiler (used to) spend
almost all its time handling insts, the speedup is about 40%.

This diff also contains some small incidental changes I stumbled upon
the "need" for while working on the main change.

compiler/prog_data.m:
    The existing inst_test_results type used to be able to hold the results
    of four tests about a bound inst. Add two more: the set of inst vars that
    may occur in the inst, and whether a type constructor has already been
    propagated into the cons_ids of the bound insts.

    Put the fields of the the unify_inst and merge_inst inst_names into
    a more sensible order.

    Define types that hold the information stored in specific kinds of
    inst_names, for use by hlds_data.m (see below).

compiler/inst_user.m:
    For each user defined bound inst that matches exactly one parameterless
    type, propagate its type constructor into it, and record the fact that
    it has been done. This avoids having to do it many times later.
    Also record the set of inst vars in each inst, again to avoid having
    to repeat the test many times later.

compiler/mercury_compile_front_end.m:
    Invoke the inst_user module as soon after inst_check.m as we can.

compiler/hlds_data.m:
    Make the structure of six subtables of the inst table private, to allow
    them to be experimented with (and possibly changed) without code changes
    being required in other modules.

    The unify_inst_table, the ground_inst_table and the any_inst_table
    used to be maps whose keys were inst_names, but they were each only ever
    used with one kind of inst_name. Change their keys to the new types
    unify_inst_info, ground_inst_info and any_inst_info, which each contain
    the information in the unify_inst, ground_inst and any_inst inst_names
    respectively. That way, the searches in the maps will perform comparisons
    that don't need to switch on what kind of inst_name they are dealing with,
    and instead go directly to comparing the arguments.

    With the unify_inst_table, also go a step further. The unify_inst_info
    has two fields that are equivalent to booleans. Comparing these
    at every level of the map is wasteful, so switch the representation
    of the unify_inst_table from one map to four maps, one map for each
    possible combination of those booleans. This way, the two booleans
    in the unify_inst_info key are tested just once, when the applicable map
    is selected.

    The merge_inst_table used to have a pair of insts as keys. Replace that
    with the merge_inst_info type, which also holds a pair of insts,
    but on which comparisons should be a bit faster, since it is not
    polymorphic, and thus does not need an implicit typeinfo passed along.

    Provide a combined search_insert operation on each of the inst_tables,
    since their pattern of use is exactly that: search the table, and if
    the key is not found, insert a marker that says the entry is being
    worked on. This avoid one traversal of a possibly-large tree, with
    its associated (possibly very expensive) comparisons.

    For each inst table, provide conversion predicates to and from
    sorted association lists, for use by equiv_type_hlds.m

compiler/equiv_type_hlds.m:
    Expand equivalence types in the new structure of the inst tables.

compiler/inst_util.m:
    Use the new search_insert predicates for the various inst_tables.

    If one of the two insts being unified is free, then avoid using
    the unify_inst_table, since just doing the abstract unification
    is faster, and does not pollute the unify_inst_table.

    If both insts being merged are bound insts, then avoid using the
    merge_inst_table, since (a) the lookup is slower than just doing
    the merge, and (b) it can pollute the merge_inst_table to the extent
    that *all other lookups* in it become very slow.

compiler/inst_match.m:
    Use test result information in bound insts to speed up the corresponding
    tests.

compiler/set_of_var.m:
    Change the representation of sets of vars back to sparse_bitsets.
    I changed them to tree_bitsets several years ago to avoid some bad
    worst-case behavior with sparse_bitsets (which occurred when repeatedly
    appending to the "ends" of sets), but other algorithmic changes have
    since avoiding using set_of_vars in ways that induce that behavior,
    and now my benchmarking tells me that the bottleneck operation is
    conversion of set_of_vars to lists of vars. This is faster with
    sparse_bitsets, since unlike tree_bitsets, they don't have to unravel
    a tree structure.

compiler/mode_util.m:
    Export a predicate now needed by inst_user.m, and clean up the code a bit,
    factoring out repeated code.

compiler/modecheck_util.m:
    Modify an equality comparison of two insts to compare the instantiation
    states themselves, but NOT the test results about those instantiation
    states, since these can differ if the two insts have different histories.

compiler/hlds_code_util.m:
compiler/hlds_out_mode.m:
compiler/hlds_out_module.m:
compiler/mercury_to_mercury.m:
compiler/module_qual.m:
compiler/polymorphism.m:
compiler/prog_mode.m:
compiler/recompilation.usage.m:
compiler/unused_imports.m:
compiler/xml_documentation.m:
    Conform to the changes above.

The following changes are mostly incidental.

compiler/hlds_args.m:
    Speed up a predicate by avoiding the materialization of a list
    that is needed only for a test.

compiler/instmap.m:
    Clarify some code.

compiler/liveness.m:
    Avoid computing some value when it is not needed.

compiler/mode_errors.m:
    Avoid referring to "arguments" (plural) for errors involving *one*
    argument.

compiler/mode_info.m:
    Move the documentation of some predicates to their declarations.

compiler/modecheck_unify.m:
    Compute some data closer to where it is needed, to reduce the number
    of stack slots needed.

tests/invalid/constrained_poly_insts2.err_exp:
    Expect the updated error message from mode_errors.m (with "argument"
    in singular), as well as module qualified insts, since having inst_user.m
    push type_ctors into the definitions of named inst module qualifies
    the bound_insts inside those definitions.
2015-03-05 20:01:00 +11:00
Zoltan Somogyi
c1402f8b99 Clean up hlds_module.m.
compiler/hlds_module.m:
    Put related fields of the module_sub_info next to each other.

    Some of those fields contained lists that were built reversed,
    in order to avoid O(N^2) behavior when repeatedly adding new items
    to the end of the list. Replace these with cords, which did not exist
    when those fields were first added.

    Give some fields and their getter/setter predicates more descriptive
    names.

    Separate out both the declarations and definitions of the getter and
    setter predicates, and put them into the same order as the (updated)
    order of the fields. Put the utility predicates (those that are more
    complicated than just getters or setters) into an order based on
    what fields they work on, following the same order.

    Improve the operation of some of the utility predicates, e.g. replacing
    a nondet predicate with a det predicate returning a set.

    Delete an unused type.

    Conform to the changes in the modules imported by hlds_module.m,
    e.g. pred_table.m, prog_data.m and prog_foreign.m.

compiler/pred_table.m:
    We used to store the set of valid pred ids as two lists, again to avoid
    O(N^2) behavior. Replace the two lists with a set. This allows
    looking up the set *without* updating the pred_table, or, when
    the pred_table is within the module_info, updating the module_info.

    Instead of allowing callers to replace the set of valid pred ids wholesale,
    enforce the documented invariant on that set by only allowing deletions.

    Conform to the changes above.

compiler/add_pragma.m:
compiler/bytecode_gen.m:
compiler/check_typeclass.m:
compiler/compile_target_code.m:
compiler/cse_detection.m:
compiler/dead_proc_elim.m:
compiler/deep_profiling.m:
compiler/dep_par_conj.m:
compiler/dependency_graph.m:
compiler/deps_map.m:
compiler/det_analysis.m:
compiler/distance_granularity.m:
compiler/equiv_type_hlds.m:
compiler/erl_code_gen.m:
compiler/exception_analysis.m:
compiler/export.m:
compiler/float_regs.m:
compiler/foreign.m:
compiler/higher_order.m:
compiler/hlds_module.m:
compiler/inlining.m:
compiler/intermod.m:
compiler/introduce_parallelism.m:
compiler/lambda.m:
compiler/liveness.m:
    Conform to the changes above.

    In many places, the change to how the valid pred ids are stored
    allows us to avoid creating new module_infos.

    In some places, fix style issues I noticed while working on the above.

compiler/llds.m:
compiler/mercury_compile_llds_back_end.m:
    Conform to the changes above.

    Move a type from llds.m to mercury_compile_llds_back_end.m, since
    only the latter uses it.

compiler/prog_data.m:
compiler/prog_foreign.m:
    Replace some types that used to hold reversed lists with cords.

    In prog_foreign.m, represent the two kinds of foreign code that
    do NOT define procedures with similarly named types.

    Delete a type (user_foreign_code) that duplicated another type.

    Replace an equivalence type with a notag type, for safety.

compiler/recompilation.usage.m:
compiler/typecheck.m:
compiler/typecheck_errors.m:
    Now that we have direct access to the set of visible modules,
    simplify the logic of some code dealing with those modules.

compiler/module_imports.m:
    Put some related fields next to each other.

compiler/llds_out_file.m:
compiler/make.dependencies.m:
compiler/make.module_dep_file.m:
compiler/make_hlds_passes.m:
compiler/mark_tail_calls.m:
compiler/mercury_compile_front_end.m:
compiler/mercury_compile_middle_passes.m:
compiler/ml_proc_gen.m:
compiler/mlds.m:
compiler/mlds_to_c.m:
compiler/mlds_to_cs.m:
compiler/mlds_to_il.m:
compiler/mlds_to_java.m:
compiler/mlds_to_managed.m:
compiler/mode_constraints.m:
compiler/modes.m:
compiler/modules.m:
compiler/passes_aux.m:
compiler/polymorphism.m:
compiler/post_typecheck.m:
compiler/pred_table.m:
compiler/proc_gen.m:
compiler/prog_item.m:
compiler/purity.m:
compiler/rbmm.condition_renaming.m:
compiler/rbmm.execution_path.m:
compiler/rbmm.live_region_analysis.m:
compiler/rbmm.live_variable_analysis.m:
compiler/rbmm.points_to_analysis.m:
compiler/rbmm.region_arguments.m:
compiler/rbmm.region_instruction.m:
compiler/ssdebug.m:
compiler/stm_expand.m:
compiler/stratify.m:
compiler/structure_reuse.analysis.m:
compiler/structure_reuse.direct.m:
compiler/structure_reuse.domain.m:
compiler/structure_sharing.analysis.m:
compiler/structure_sharing.domain.m:
compiler/switch_detection.m:
compiler/tabling_analysis.m:
compiler/term_constr_initial.m:
compiler/term_constr_main.m:
compiler/termination.m:
compiler/trailing_analysis.m:
compiler/trans_opt.m:
compiler/try_expand.m:
compiler/type_constraints.m:
compiler/untupling.m:
compiler/unused_args.m:
compiler/write_deps_file.m:
2014-12-29 22:18:51 +11:00
Zoltan Somogyi
13b6f03f46 Module qualify end_module declarations.
compiler/*.m:
    Module qualify the end_module declarations. In some cases, add them.

compiler/table_gen.m:
    Remove an unused predicate, and inline another in the only place
    where it is used.

compiler/add_pragma.m:
    Give some predicates more meaningful names.
2014-09-04 00:24:52 +02:00
Peter Wang
d67f1f87e9 Fix compiler abort during liveness detection.
The compiler would abort during liveness detection on an if-then-else goal
with an unreachable Then branch, due to the Then goal not having its
liveness-related fields initialised.  Bug #51.

compiler/liveness.m:
	    As above.

tests/valid/Mercury.options:
tests/valid/Mmakefile:
tests/valid/bug51.m:
	    Add test case.

NEWS:
	    Announce the change.
2013-09-09 16:17:28 +10:00
Zoltan Somogyi
16bd4acd2f Shorten lines longer than 79 characters.
Estimated hours taken: 2
Branches: main

compiler/*.m:
	Shorten lines longer than 79 characters.
2012-10-24 05:49:47 +00:00
Zoltan Somogyi
6d1bc24d0b Make vartypes an abstract data type, in preparation for exploring
Estimated hours taken: 4
Branches: main

compiler/prog_data.m:
	Make vartypes an abstract data type, in preparation for exploring
	better representations for it.

compiler/mode_util.m:
	Provide two different versions of a predicate. The generic version
	continues to use map lookups. The other version knows it works on
	prog_vars, so it can use the abstract operations on them provided
	by prog_data.m.

compiler/accumulator.m:
compiler/add_class.m:
compiler/add_heap_ops.m:
compiler/add_pragma.m:
compiler/add_pred.m:
compiler/add_trail_ops.m:
compiler/arg_info.m:
compiler/builtin_lib_types.m:
compiler/bytecode_gen.m:
compiler/call_gen.m:
compiler/clause_to_proc.m:
compiler/closure_analysis.m:
compiler/code_info.m:
compiler/common.m:
compiler/complexity.m:
compiler/const_prop.m:
compiler/constraint.m:
compiler/continuation_info.m:
compiler/cse_detection.m:
compiler/ctgc.datastruct.m:
compiler/ctgc.util.m:
compiler/deep_profiling.m:
compiler/deforest.m:
compiler/dep_par_conj.m:
compiler/det_analysis.m:
compiler/det_report.m:
compiler/det_util.m:
compiler/disj_gen.m:
compiler/equiv_type_hlds.m:
compiler/erl_call_gen.m:
compiler/erl_code_gen.m:
compiler/erl_code_util.m:
compiler/exception_analysis.m:
compiler/float_regs.m:
compiler/follow_vars.m:
compiler/format_call.m:
compiler/goal_path.m:
compiler/goal_util.m:
compiler/hhf.m:
compiler/higher_order.m:
compiler/hlds_clauses.m:
compiler/hlds_goal.m:
compiler/hlds_out_goal.m:
compiler/hlds_out_pred.m:
compiler/hlds_pred.m:
compiler/hlds_rtti.m:
compiler/inlining.m:
compiler/instmap.m:
compiler/intermod.m:
compiler/interval.m:
compiler/lambda.m:
compiler/lco.m:
compiler/live_vars.m:
compiler/liveness.m:
compiler/lookup_switch.m:
compiler/mercury_to_mercury.m:
compiler/ml_accurate_gc.m:
compiler/ml_closure_gen.m:
compiler/ml_code_gen.m:
compiler/ml_code_util.m:
compiler/ml_disj_gen.m:
compiler/ml_lookup_switch.m:
compiler/ml_proc_gen.m:
compiler/ml_unify_gen.m:
compiler/mode_info.m:
compiler/modecheck_call.m:
compiler/modecheck_conj.m:
compiler/modecheck_goal.m:
compiler/modecheck_unify.m:
compiler/modecheck_util.m:
compiler/modes.m:
compiler/par_loop_control.m:
compiler/pd_info.m:
compiler/pd_util.m:
compiler/polymorphism.m:
compiler/post_typecheck.m:
compiler/prog_type_subst.m:
compiler/prop_mode_constraints.m:
compiler/purity.m:
compiler/qual_info.m:
compiler/rbmm.points_to_info.m:
compiler/rbmm.region_liveness_info.m:
compiler/rbmm.region_transformation.m:
compiler/saved_vars.m:
compiler/simplify.m:
compiler/size_prof.m:
compiler/ssdebug.m:
compiler/stack_alloc.m:
compiler/stack_opt.m:
compiler/store_alloc.m:
compiler/structure_reuse.analysis.m:
compiler/structure_reuse.direct.choose_reuse.m:
compiler/structure_reuse.direct.detect_garbage.m:
compiler/structure_reuse.indirect.m:
compiler/structure_sharing.analysis.m:
compiler/structure_sharing.domain.m:
compiler/switch_detection.m:
compiler/table_gen.m:
compiler/term_constr_build.m:
compiler/term_constr_util.m:
compiler/term_traversal.m:
compiler/term_util.m:
compiler/trace_gen.m:
compiler/trailing_analysis.m:
compiler/try_expand.m:
compiler/tupling.m:
compiler/type_constraints.m:
compiler/type_util.m:
compiler/typecheck.m:
compiler/typecheck_errors.m:
compiler/typecheck_info.m:
compiler/unify_gen.m:
compiler/unify_proc.m:
compiler/unique_modes.m:
compiler/untupling.m:
compiler/unused_args.m:
compiler/var_locn.m:
	Conform to the above.

compiler/prog_type.m:
compiler/rbmm.points_to_graph.m:
	Conform to the above.

	Move some comments where they belong.

compiler/stm_expand.m:
	Conform to the above.

	Do not export a predicate that is not used outside this module.

	Disable some debugging output unless it is asked for.

	Remove unnecessary prefixes on variable names.

library/version_array.m:
	Instead writing code for field access lookalike functions and defining
	lookup, set etc in terms of them, write code for lookup, set etc,
	and define the field access lookalike functions in terms of them.

	Change argument orders of some internal predicates to be
	more state variable friendly.

	Fix typos in comments.

tests/hard_coded/version_array_test.exp:
	Conform to the change to version_array.m.
2012-07-02 01:16:39 +00:00
Peter Wang
b86f973fa9 Allow the use of Mercury abstract machine float registers for passing
Branches: main

Allow the use of Mercury abstract machine float registers for passing
double-precision float arguments in higher order calls.

In of itself this is not so useful for typical Mercury code.  However, as
all non-local procedures are potentially the targets of higher order calls,
without this change first order calls to non-local procedures could not use
float registers either.  That is the actual motivation for this change.

The basic mechanism is straightforward.  As before, do_call_closure_* is
invoked to place the closure's hidden arguments into r1, ..., rN, and extra
input arguments shifted into rN+1, etc.  With float registers, extra input
arguments may also be in f1, f2, etc. and the closure may also have hidden
float arguments.  Optimising for calls, we order the closure's hidden
arguments so that all float register arguments come after all regular
register arguments in the vector.  Having the arguments out of order does
complicate code which needs to deconstruct closures, but that is not so
important.

Polymorphism complicates things.  A closure with type pred(float) may be
passed to a procedure expecting pred(T).  Due to the `float' argument type,
the closure expects its argument in a float register.  But when passed to the
procedure, the polymorphic argument type means it would be called with the
argument in a regular register.

Higher-order insts already contain information about the calling convention,
without which a higher-order term cannot be called.  We extend higher-order
insts to include information about the register class required for each
argument.  For example, we can distinguish between:

	pred(in) is semidet /* arg regs: [reg_f] */
and
	pred(in) is semidet /* arg regs: [reg_r] */

Using this information, we can create a wrapper around a higher-order
variable if it appears in a context requiring a different calling convention.
We do this in a new HLDS pass, called float_regs.m.

Note: Mercury code has a tendency to lose insts for higher-order terms, then
"recover" them by hacky means.  The float_regs pass depends on higher-order
insts; it is impossible to create a wrapper for a procedure without knowing
how to call it.  The float_regs pass will report errors which we otherwise
accepted, due to higher-order insts being unavailable.  It should be possible
for the user to adjust the code to satisfy the pass, though the user may not
understand why it should be necessary.  In most cases, it probably really
*is* unnecessary.  We may be able to make the float_regs pass more tolerant
of missing higher-order insts in the future.

Class method calls do not use float registers because I didn't want to deal
with them yet.


compiler/options.m:
compiler/handle_options.m:
	Always enable float registers in low-level C grades when floats are
	wider than a word.

compiler/make_hlds_passes.m:
	Always allow double word floats to be stored unboxed in cells on C
	grades.

compiler/hlds_goal.m:
	Add an extra field to `generic_call' which gives the register class
	to use for each argument.  This is set by the float_regs pass.

compiler/prog_data.m:
	Add an extra field to `pred_inst_info' which records the register class
	to use for each argument.  This is set by the float_regs pass.

compiler/hlds_pred.m:
	Add a field to `proc_sub_info' which lists the headvars which must be
	passed via regular registers despite their types.

	Add a field to `pred_sub_info' to record the original unsubstituted
	argument types for instance method predicates.

compiler/check_typeclass.m:
	In the pred_info of an instance method predicate, record the original
	argument types before substituting the type variables for the instance.

compiler/float_regs.m:
compiler/transform_hlds.m:
	Add the new HLDS pass.

compiler/mercury_compile_middle_passes.m:
	Run the new pass if float registers are enabled.

compiler/lambda.m:
	Export the predicate to produce a predicate from a lambda.
	This is reused by float_regs.m to create wrapper closures.

	Add an argument to `expand_lambda' to set the reg_r_headvars field on
	the newly created procedure.

	Delete some unused fields from `lambda_info'.

compiler/arg_info.m:
	Make `generate_proc_arg_info' no longer always use regular registers
	for calls to exported procedures.  Do always use regular registers for
	class methods calls.

	Add a version of `make_arg_infos' which takes an explicit list of
	argument registers.  Rename the previous version.

	Add `generic_call_arg_reg_types' to return the argument registers
	for a generic call.

	Add a version of `compute_in_and_out_vars' which additionally separates
	arguments for float and regular registers.

compiler/call_gen.m:
	Use float registers for argument passing in higher-order calls, as
	directed by the new field in `generic_call'.

compiler/code_util.m:
	Add a function to encode the number of regular and float register
	arguments when making a higher-order call.

compiler/llds.m:
	Say that the `do_call_closure_N' functions only work for zero float
	register arguments.

compiler/follow_vars.m:
compiler/interval.m:
	Account for the use of float registers by generic call goals in these
	passes.

compiler/unify_gen.m:
	Move float register arguments to the end of a closure's hidden
	arguments vector, after regular register arguments.

	Count hidden regular and float register arguments separately, but
	encode them in the same word in the closure.  This is preferable to
	using two words because it reduces the differences between grades
	with and without float registers present.

	Disable generating code which creates a closure from an existing
	closure, if float registers exist.  That code does not understand the
	reordered hidden arguments vector yet.

compiler/continuation_info.m:
	Replace an argument's type_info in the closure layout if the argument
	is a float *and* is passed via a regular register, when floats are
	normally passed via float registers.  Instead, give it the type_info
	for `private_builtin.float_box'.

compiler/builtin_lib_types.m:
	Add function to return the type of `private_builtin.float_box/0'.

compiler/hlds_out_goal.m:
compiler/hlds_out_pred.m:
compiler/mercury_to_mercury.m:
	Dump the new fields added to `generic_call', `pred_inst_info' and
	`proc_sub_info'.

compiler/prog_type.m:
	Add helper predicate.

compiler/*.m:
	Conform to changes.

library/private_builtin.m:
	Add a type `float_box'.

runtime/mercury_ho_call.h:
	Describe the modified closure representation.

	Rename the field which counts the number of hidden arguments to prevent
	it being used incorrectly, as it now encodes two numbers (potentially).

	Add macros to unpack the encoded field.

runtime/mercury_ho_call.c:
	Update the description of how higher-order calls work.

	Update code which extracts closure arguments to take account the
	arguments being reordered in the hidden arguments vector.

runtime/mercury_deep_copy.c:
runtime/mercury_deep_copy_body.h:
runtime/mercury_layout_util.c:
runtime/mercury_ml_expand_body.h:
	Update code which extracts closure arguments to take account the
	arguments being reordered in the hidden arguments vector.

runtime/mercury_type_info.c:
runtime/mercury_type_info.h:
	Add helper function.

tools/make_spec_ho_call:
	Update the generated do_call_closure_* functions to place float
	register arguments.

tests/hard_coded/Mercury.options:
tests/hard_coded/Mmakefile:
tests/hard_coded/ho_float_reg.exp:
tests/hard_coded/ho_float_reg.m:
	Add new test case.

tests/hard_coded/copy_pred.exp:
tests/hard_coded/copy_pred.m:
tests/hard_coded/deconstruct_arg.exp:
tests/hard_coded/deconstruct_arg.exp2:
tests/hard_coded/deconstruct_arg.m:
	Extend test cases with float arguments in closures.

tests/debugger/higher_order.exp2:
	Add alternative output, changed due to closure wrapping.

tests/hard_coded/ho_univ_to_type.m:
	Adjust test case so that the float_regs pass does not report errors
	about missing higher-order insts.

compiler/notes/compiler_design.html:
	Describe the new module.

	Delete a duplicated paragraph.

compiler/notes/todo.html:
TODO:
	Delete one hundred billion year old todos.
2012-02-13 00:11:57 +00:00
Zoltan Somogyi
585c1d623c Fix a problem with from_ground_term scopes.
Estimated hours taken: 20
Branches: main

Fix a problem with from_ground_term scopes. When they are built, the scopes
are tentantively marked as from_ground_term_construct scopes, and the
unifications inside them are in a top down order. Mode analysis therefore
expected the unifications inside from_ground_term_construct scopes to have
that order.

The problem was that mode analysis, when it confirmed that a
from_ground_term scope is indeed a from_ground_term_construct scope,
itself reversed the order of the unifications, putting them in a bottom up
order. When mode analysis is reinvoked, either for unique mode checking, or
after cse_detection finds common subexpressions, this meant that
mode analysis found the unifications in the "wrong" order, and therefore
disregarded the scope, discarding all its performance benefits.

This diff separates out the two notions that we previously conflated.
The scope kind from_ground_term_construct now refers only to scopes
which are definitely known to construct ground terms. We can know that
only after mode analysis. Until then, from_ground_term scopes are now marked
as from_ground_term_initial. The two kinds have different though overlapping
sets of invariants; in particular, they promise different orderings of the
unifications in the scope.

This diff reduces the time needed to compile mas_objects.data.m
from about 221 seconds to about 8.

compiler/hlds_goal.m:
	Add the from_ground_term_initial kind. Document the invariants
	that each kind of from_ground_term scope promises.

compiler/superhomogeneous.m:
	Mark from_ground_term scopes initially as from_ground_term_initial,
	not from_ground_term_construct.

compiler/post_typecheck.m:
	Make the predicate that converts function calls that look like
	unifications (such as X = int.min) into actual function calls
	say whether it performed such a conversion.

compiler/purity.m:
	Use the new functionality in post_typecheck.m to convert
	from_ground_term_initial scopes into from_ground_term_other scopes
	if the conversion of a unification into a call means that we have to
	break an invariant expected of from_ground_term_initial scopes.

compiler/cse_detection.m:
compiler/switch_detection.m:
	Maintain the invariants we now expect of from_ground_term_deconstruct
	scopes.

compiler/modecheck_goal.m:
	Maintain the invariants we now expect of the different
	from_ground_term scopes.

	Avoid traversing such scopes if a previous invocation of mode analysis
	says we can.

	Optimize away from_ground_term_construct scopes if the variable being
	constructed is not needed later.

compiler/quantification.m:
	If the variable named in a from_ground_term_initial or
	from_ground_term_construct scope is not referred to outside the scope,
	set the nonlocals set of the scope to empty, which allows later
	compiler passes to optimize it away.

	Avoid some unnecessary work by the compiler.

compiler/add_trail_ops.m:
compiler/closure_analysis.m:
compiler/constraint.m:
compiler/dead_proc_elim.m:
compiler/deep_profile.m:
compiler/deforest.m:
compiler/delay_construct.m:
compiler/delay_partial_inst.m:
compiler/dep_par_conj.m:
compiler/dependency_graph.m:
compiler/exception_analysis.m:
compiler/follow_code.m:
compiler/follow_vars.m:
compiler/goal_form.m:
compiler/goal_util.m:
compiler/granularity.m:
compiler/inlining.m:
compiler/interval.m:
compiler/lambda.m:
compiler/lco.m:
compiler/middle_rec.m:
compiler/mode_util.m:
compiler/parallel_to_plain.m:
compiler/simplify.m:
compiler/stm_expand.m:
compiler/stratify.m:
compiler/tabling_analysis.m:
compiler/term_pass1.m:
compiler/try_expand.m:
compiler/tupling.m:
compiler/untupling.m:
compiler/unused_args.m:
	Avoid traversing from_ground_term_deconstruct scopes in cases
	where the invariants that now hold (mainly the absence of anything
	but deconstruct unifications) make such traversals unnecessary.

compiler/live_vars.m:
compiler/liveness.m:
compiler/structure_reuse.lbu.m:
	Add comments about exploiting from_ground_term_deconstruct scopes.

compiler/det_analysis.m:
compiler/hlds_out_goal.m:
compiler/polymorphism.m:
compiler/saved_vars.m:
compiler/unique_modes.m:
	Handle from_ground_term_initial scopes.

compiler/handle_options.m:
	Add a dump verbosity option that is useful for comparing HLDS dumps
	created by two different compilers.

compiler/type_util.m:
	Minor speedup.

compiler/mode_info.m:
compiler/modecheck_conj.m:
compiler/prog_data.m:
compiler/rbmm.region_transformation.m:
compiler/typecheck.m:
	Improve documentation.
2011-08-31 07:59:35 +00:00
Zoltan Somogyi
d00ea69529 Switch from using set(prog_var), which is represented using set_ordlist,
Estimated hours taken: 12
Branches: main

Switch from using set(prog_var), which is represented using set_ordlist,
to set_of_progvar, which is represented using tree_bitset, for most sets
of variables in the compiler, including the nonlocals sets in goal_infos.

This diff yields about a 5% speedup when compiling the training_cars_full.m
stress test, but also about a 1% slowdown on tools/speedtest. Both of these
are with the current default state in which tree_bitset is compiled with
a whole bunch of sanity checks. If these are disabled, we get roughly a 1%
speedup on tools/speedtest. I intend to disable those sanity checks after
a shakedown period of a week or two in which the updated version of the
compiler is installed on our platforms.

compiler/hlds_goal.m:
	Replace almost all occurrences of set(prog_var) with set_of_progvar.
	The main exceptions are the types supporting rbmm.

compiler/set_of_var.m:
	Add some more predicates and functions that previous existed on sets
	but not yet on set_of_vars.

compiler/*.m:
	Conform to the change in hlds_goal.m, and make similar changes
	in set representations.

library/bag.m:
	Add a predicate and function for creating a bag from a sorted list.
	We already had them for creating a bag from a set, but a set_of_progvar
	shouldn't have to be converted to a set.

library/robdd.m:
	Fix deviations from our programming style.
2011-08-16 03:26:40 +00:00
Zoltan Somogyi
79da38363f Do not delay the death of variables in debug grades if the number
Estimated hours taken: 2
Branches: main

compiler/liveness.m:
	Do not delay the death of variables in debug grades if the number
	of variables in the procedure exceeds a configurable threshold.
	Delaying the death of variables means that at later and later calls,
	there are more and more variables whose values need to be saved on the
	stack. This has several bad consequences in large procedures:

	- some data structures, such as the livevals instructions we generate
	  before calls, have size that is linear in both the number of calls
	  and the number of variables, and therefore they tend to be quadratic
	  overall in size;
	- computing these data structures will take time that is at least
	  quadratic, and maybe worse;
	- since we generate both more and bigger live sets, the stack slot
	  allocation pass will take time that seems to be at least qubic;
	- the algorithm for trying to compress the pseudo-typeinfo array
	  describing all the stack slots at all the call sites will definitely
	  take qubic time;
	- it will also generate HUGE arrays, leading to HUGE .c files
	  (almost one GIGABYTE for zm_enums.m);
	- these huge files will take a long time to write out, and to compile
	  and link.

	The impact of this change on debuggability should be small, since
	the first step in debugging such huge procedures do is almost
	certainly breaking them up into small, understandable pieces.

compiler/options.m:
	Add an option, --delay-death-max-vars=N, to control the cutoff in
	liveness.m. Set the default value to 1000. This affects only a few
	predicates in the compiler, such as the huge switches in options.m,
	and the many-page predicate in handle_options.m.

doc/user_guide.texi:
	Document the new option.

	Fix the formatting of the text for a nearby existing option.

library/term.m:
library/varset.m:
	Add utility functions now needed by liveness.m.
2011-07-25 07:54:21 +00:00
Zoltan Somogyi
7487590f2d Predicates with many variables, such as some of those in zm_enums.m,
Estimated hours taken: 24
Branches: main

Predicates with many variables, such as some of those in zm_enums.m,
tickle pretty bad behavior in the liveness and stack_alloc passes.
This is because those passes manipulate sets of variables, which in
such cases are large sets of variables, and the quadratic behavior
of repeated operations on sets represents as sorted lists hurts us.

This diff changes the representation of the sets of variables involved
in those two passes, which are the prebirth, postbirth, predeath and postdeath
sets in goal_infos, to be values of an abstract type (set_of_progvar).
By default, these are implemented using tree_bitsets, which have much better
worst case behaviour that set_ordlists.

When compiling zm_enums with debugging enabled, this diff speeds up
the liveness pass by about half and the stack alloc pass by about a third,
with the overall speedup being about 6% (due to some other expensive passes).

On tools/speedtest -l, the result is a 3.4% slowdown. Since the slowdown
worsens slightly if I make the abstract representation of sets of prog_vars
be the existing representation (an ordinary set), I think this slowdown is
due to the conversions that are now required in some places between the
abstract representation and an explicit set(prog_var) representation.
As such, as other uses of set(progvar) get converted to set_of_progvar,
this slowdown should disappear.

compiler/set_of_var.m:
	The new module that contains the set_of_progvar abstract data type.

	This module also contains a copy of the code of the graph_colour
	module. Since the set_of_progvar type is private, this is necessary
	if we want all the set operations done by graph colouring (which does
	the bulk of the work of the stack alloc pass) to use the preferred
	set representation.

compiler/graph_colour.m:
	Note that this module is no longer used.

compiler/stack_alloc.m:
compiler/liveness.m:
	Switch over to using the new module.

compiler/parse_tree.m:
	Include set_of_var among the modules of this package. (It is in this
	package because the prog_var type is defined in this package.)

compiler/test_bitset.m:
	A module that allows new set implementations to be tested. It is
	an extended and specialized version of the bitset_tester module
	from tests/hard_coded.

compiler/hlds_llds.m:
	Use the set_of_progvar type for the prebirth, postbirth, predeath
	and postdeath sets in goal_infos, and for other liveness-related
	sets of variables.

compiler/code_info.m:
	Some of the fields of the code_info structure represent sets of
	variables, and some of the predicates defined by this module have
	arguments that are sets of variables. If these sets represent entities
	that are computed from prebirth, postbirth, predeath and postdeath
	sets or from other goal_info fields that have been changed to the
	set_of_progvar representation, change them to use the set_of_progvar
	representation as well, or, in a few cases, to plain sorted lists.

	Conform to the above change.

compiler/proc_type.m:
	Add a utility predicate to operate of set_of_progvar.

	Replace a lambda expression with a named predicate.

compiler/quantification.m:
	Until now, quantification.m used its own private abstract type
	(defined as tree_bitset) to represent sets. Make it use set_of_progvar
	instead, since it has the same purpose. This eliminates a potential
	maintenance problem.

compiler/call_gen.m:
compiler/code_gen.m:
compiler/commit_gen.m:
compiler/delay_construct.m:
compiler/disj_gen.m:
compiler/hlds_out_goal.m:
compiler/hlds_rtti.m:
compiler/interval.m:
compiler/ite_gen.m:
compiler/live_vars.m:
compiler/lookup_switch.m:
compiler/lookup_util.m:
compiler/matching.m:
compiler/pd_util.m:
compiler/polymorphism.m:
compiler/pragma_c_gen.m:
compiler/proc_gen.m:
compiler/simplify.m:
compiler/stack_opt.m:
compiler/store_alloc.m:
compiler/string_switch.m:
compiler/structure_reuse.lbu.m:
compiler/structure_reuse.lfu.m:
compiler/structure_sharing.domain.m:
compiler/switch_util.m:
compiler/trace_gen.m:
compiler/tupling.m:
compiler/unify_gen.m:
compiler/unused_args.m:
	Conform to the above change.

library/map.m:
	Add a utility predicate, map.select_sorted_list, which functions the
	same way as map.select, but takes a sorted list as argument instead of
	a set.

library/set_ordlist.m:
	Bring the interface of this module closer to set.m and tree_bitset.m
	to make them more easily interchangeable. This required adding the
	predicates is_non_empty and is_singleton, as well as adding predicate
	forms of union_list and intersect_list.

	I also added missing type_spec pragmas for some predicates frequently
	used by the compiler.

library/tree_bitset.m:
	Bring the interface of this module closer to set.m and set_ordlist.m
	to make them more easily interchangeable. This required adding the
	predicates is_non_empty and is_singleton, and both function and
	predicate forms of union_list and intersect_list.

	Fix an old bug in the difference operation. Given SetA - SetB,
	if SetA was the empty set, then this operation would correctly
	return the empty set if SetB was small (represented by a leaf list),
	but would incorrectly return SetB if it was large (represented by
	an interior node list).
2011-07-21 06:58:34 +00:00
Zoltan Somogyi
295415090e Convert almost all remaining modules in the compiler to use
Estimated hours taken: 6
Branches: main

compiler/*.m:
	Convert almost all remaining modules in the compiler to use
	"$module, $pred" instead of "this_file" in error messages.

	In a few cases, the old error message was misleading, since it
	contained an incorrect, out-of-date or cut-and-pasted predicate name.

tests/invalid/unresolved_overloading.err_exp:
	Update an expected output containing an updated error message.
2011-05-23 05:08:24 +00:00
Julien Fischer
9ae7fe6b70 Change the argument ordering of predicates in the set module.
Branches: main

Change the argument ordering of predicates in the set module.

library/set.m:
	Change predicate argument orders to match the versions
	in the svset module.

	Group function definitions with the corresponding predicates
	rather than at the end of the file.

	Delete Ralph's comments regarding the argument order in the
	module interface: readers of the library reference guide are
	unlikely to be interested in his opinion of the argument ordering
	ten or so years ago.

	Add extra modes for set.map/3 and set.map_fold/5.

library/svset.m:
library/eqvclass.m:
library/tree234.m:
library/varset.m:
browser/*.m:
compiler/*.m:
deep_profiler/*.m:
mdbcomp/trace_counts.m:
extras/moose/grammar.m:
extras/moose/lalr.m:
extras/moose/moose.m:
tests/hard_coded/bitset_tester.m:
	Conform to the above change.

NEWS:
	Announce the above changes.
2011-05-06 05:03:29 +00:00
Zoltan Somogyi
1c3bc03415 Make the system compiler with --warn-unused-imports.
Estimated hours taken: 2
Branches: main, release

Make the system compiler with --warn-unused-imports.

browser/*.m:
library/*.m:
compiler/*.m:
	Remove unnecesary imports as flagged by --warn-unused-imports.

	In some files, do some minor cleanup along the way.
2010-12-30 11:18:04 +00:00