Commit Graph

183 Commits

Author SHA1 Message Date
Zoltan Somogyi
4fc654143f Improve style. 2023-04-07 04:31:53 +10:00
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
93bf6018d5 More changes making using var_tables the default.
compiler/goal_util.m:
    Add a "_vs" suffix to the names of predicates that use varsets, and
    delete the "_table" suffix from the names of predicates that use
    var_tables.

compiler/hlds_out_pred.m:
    Delete one of two predicates that write out var tables, and use only
    the other one.

compiler/prog_util.m:
    Delete make_n_fresh_vars_vt, since it put dummy information in
    new var_table_entries, requiring them to be filled in with real info later.
    All users of it switched to constructing var_table_entries with
    real information from the start.

compiler/*.m:
    Conform to the changes above.
2022-08-18 22:44:23 +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
28f0000487 Rename predicates to avoid ambiguities. 2022-07-06 14:33:10 +10:00
Zoltan Somogyi
de9a82e97e Convert inlining and deforestation to var_tables.
compiler/constraint.m:
compiler/deforest.m:
compiler/inlining.m:
compiler/pd_info.m:
compiler/pd_util.m:
    Convert the inlining and deforestation passes to var_tables.
    (constraint.m, pd_info.m and pd_util.m are part of deforestation.)

    Improve the argument order of a few predicates.

compiler/goal_util.m:
    Add back a bit of flexibility to clone_variables that its var table
    versions have not needed until now: the ability to take the data
    of the var being cloned from a var_table that is separate from
    the one being updated.

compiler/dep_par_conj.m:
compiler/quantification.m:
    Conform to the changes above.

compiler/var_table.m:
    Add a utility function.
2022-04-19 04:23:12 +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
02f0128c5a Use var_tables in more of the later passes.
compiler/add_heap_ops.m:
compiler/add_trail_ops.m:
compiler/float_regs.m:
compiler/lambda.m:
compiler/mark_tail_calls.m:
    Convert these passes to use var_tables instead of varsets and vartypes.

compiler/hlds_pred.m:
    Provide predicates to get and set "the var_table" of a procedure.
    The proc_info still stores varsets and vartypes, but these new predicates
    do the required conversions between representations. Likewise, provide
    a version of proc_info_create that takes a var_table argument instead
    of a varset and vartypes arguments. The new predicates should reduce
    the need for such conversions to be done elsewhere during the transition.

compiler/var_table.m:
    Provide a predicate to turn a var_table back into
    a <varset, vartypes> pair.

    Provide two transitional types, var_db and var_type_source, that
    provide either
    - the functionality of both a varset and a vartypes, or
    - just the functionality of a vartypes,
    using either those structure(s), or a var_table.

    Make it possible to allocate new variables from a var_table,
    by including in it a counter that takes on the role played by
    the var_supply in varsets.

    Provide a predicate to look up the types of several variables at once.

    Provide a way to construct a var_table from a reverse sorted assoc list.

compiler/vartypes.m:
    Provide a way to construct a var_table from a reverse sorted assoc list,
    to allow code to operate the same way on vartypes as on var_tables.

library/varset.m:
    Provide predicates to make the changes in var_table.m possible.
    They have to be exported, but they are in the second interface section,
    so they are not publicly documented.

compiler/quantification.m:
compiler/recompute_instmap_deltas.m:
compiler/goal_util.m:
    Provide versions of some exported predicates that take var_tables
    instead of varsets and vartypes, for use by the modules above.

    Rationalize the argument order of some predicates.

compiler/instmap.m:
    Generalize some existing predicates to take type information
    from either vartypes or var_tables, using a transitional mechanism
    now provided by var_table.m.

    Rationalize the argument order of some predicates.

compiler/inlining.m:
    Fix an unrelated bug that just happened to be tickled by the
    rest of this diff. When inlining a call, set the flag that calls
    for rerunning determinism analysis on the procedure in which the
    inlining takes place if the call has an argument variable that
    does not occur outside the call. We need to do this because
    ignoring the last output argument(s) of a call can reduce
    the max possible number of solutions of the call to one.

compiler/set_of_var.m:
    Provide a predicate needed by the fix in inlining.m.

compiler/prog_type.m:
    Give some predicates meaningful names, and create versions that
    return the same info in a different form (set instead of list).

compiler/add_pragma_type_spec.m:
compiler/check_typeclass.m:
compiler/code_info.m:
compiler/continuation_info.m:
compiler/deforest.m:
compiler/error_util.m:
compiler/follow_code.m:
compiler/higher_order.m:
compiler/hlds_class.m:
compiler/hlds_rtti.m:
compiler/ml_gen_info.m:
compiler/old_type_constraints.m:
compiler/parse_class.m:
compiler/parse_type_defn.m:
compiler/pd_util.m:
compiler/polymorphism.m:
compiler/polymorphism_type_class_info.m:
compiler/post_typecheck.m:
compiler/push_goals_together.m:
compiler/qual_info.m:
compiler/saved_vars.m:
compiler/simplify_goal_disj.m:
compiler/simplify_goal_ite.m:
compiler/simplify_goal_switch.m:
compiler/simplify_proc.m:
compiler/size_prof.m:
compiler/table_gen.m:
compiler/trace_gen.m:
compiler/type_assign.m:
compiler/type_ctor_info.m:
compiler/typecheck.m:
compiler/typeclasses.m:
compiler/unneeded_code.m:
compiler/unused_args.m:
    Conform to the changes above.
2022-04-17 13:44:10 +10:00
Zoltan Somogyi
fc3ce053ee Shorten long predicate names.
Rename another predicate to avoid an ambiguity.

Put the nonlocals_to_recompute parameter first consistently.
2022-04-14 00:21:29 +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
1ce46c2797 Pair lambda arg vars with their modes.
compiler/hlds_goal.m:
    This enforces the invariant that the there is one mode par argument var.

    Document that that "nonlocals" field of the lambda actually contains
    the variables that will be put into the closure.

compiler/assertion.m:
compiler/build_mode_constraints.m:
compiler/check_promise.m:
compiler/cse_detection.m:
compiler/dead_proc_elim.m:
compiler/delay_partial_inst.m:
compiler/det_analysis.m:
compiler/det_report.m:
compiler/det_util.m:
compiler/float_regs.m:
compiler/format_call.m:
compiler/goal_path.m:
compiler/goal_util.m:
compiler/hhf.m:
compiler/hlds_out_goal.m:
compiler/hlds_out_util.m:
compiler/hlds_statistics.m:
compiler/implementation_defined_literals.m:
compiler/instmap.m:
compiler/intermod.m:
compiler/lambda.m:
compiler/lco.m:
compiler/loop_inv.m:
compiler/make_hlds_warn.m:
compiler/mode_constraints.m:
compiler/mode_errors.m:
compiler/mode_ordering.m:
compiler/mode_util.m:
compiler/modecheck_unify.m:
compiler/old_type_constraints.m:
compiler/polymorphism.m:
compiler/polymorphism_lambda.m:
compiler/pre_quantification.m:
compiler/purity.m:
compiler/qual_info.m:
compiler/quantification.m:
compiler/simplify_goal_unify.m:
compiler/stratify.m:
compiler/superhomogeneous.m:
compiler/switch_detection.m:
compiler/try_expand.m:
compiler/typecheck.m:
compiler/unused_args.m:
compiler/unused_imports.m:
    Conform to the change above.
2021-08-21 17:49:42 +10:00
Zoltan Somogyi
0d7c8a7654 Specify pred or func for all pragmas.
*/*.m:
    As above.

configure.ac:
    Require the installed compiler to support this capability.
2021-06-16 15:23:58 +10:00
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
b6d4d3f30d Fix more issues reported by --warn-inconsistent-pred-order-clauses. 2019-08-24 07:53:41 +10:00
Zoltan Somogyi
9c003409a8 Fix comments. 2019-05-29 11:36:44 +02:00
Zoltan Somogyi
15aa457e12 Delete $module arg from calls to unexpected. 2018-04-07 18:25:43 +10:00
Zoltan Somogyi
d9e576a2b2 Specify the type for inst definitions.
browser/*.m:
compiler/*.m:
deep_profiler/*.m:
library/*.m:
mdbcomp/*.m:
ssdb/*.m:
    Specify the type constructor for every inst definition that lists
    the functors that values of that type may be bound to.

    In library/maybe.m, delete the inst maybe_errors/1, because
    (a) its name is misleading, since it is for the maybe_error/1 type (no s),
    and (b) there is already an inst with the non-misleading name maybe_error
    which had an identical definition.

    In compiler/dep_par_conj.m, delete two insts that were duplicates
    of insts defined in hlds_goal.m, and replace references to them
    accordingly.
2017-11-08 16:54:18 +11:00
Zoltan Somogyi
c88a777501 Delete some dead predicates.
compiler/*.m:
    Delete dead predicates that don't look likely to be used in the future
    in their current form.

    For dead predicates that may be needed in the future, shut up warnings
    about them by adding a consider_used pragma for them.

    In intermod.m, delete two unused fields in a structure.
2017-07-11 02:53:35 +02:00
Zoltan Somogyi
1e0a9bebef Fix some comments. 2017-06-29 13:28:24 +02:00
Zoltan Somogyi
10fc22ba92 Optimize a common case. 2017-06-16 19:12:20 +02:00
Zoltan Somogyi
3125b9b399 Improve quantification.m.
compiler/quantification.m:
    Break a 300-line predicate into smaller pieces.

    Put the pieces into a logical order.

    Put the quant_info type next to its access predicates.

    Put related fields of the quant_info type next to each other.

    Optimize updates to quant_infos that turn out to be no-ops.
2017-06-16 16:47:30 +02:00
Zoltan Somogyi
41c2fe79e8 Add a new language construct, the disable_warnings scope.
Its syntax is

    disable_warnings [warning_category1, ...] Goal

Its semantics is identical to Goal's semantics, with the only difference
being that the compiler will not generate warnings belonging to the listed
categories for code inside Goal.

At the moment, we support the disabling of two warning categories:
singleton variable warnings, and warnings about recursive calls that are not
*tail* recursive. However, the documentation of the latter is commented out
until we use the same code for generating such warnings regardless of what
backend generates code.

doc/reference_manual.texi:
    Document the new language extension.

NEWS:
    Mention the new language extension.

library/ops.m:
    Make "disable_warnings" (and its "disable_warning" variant) binary prefix
    operators, as required for the syntax of the new scope.

compiler/prog_item.m:
    Add disable_warnings_expr as a new kind of goal in the parse tree.

compiler/hlds_goal.m:
    Add disable_warnings as a new kind of scope goal in the HLDS.

compiler/prog_data.m:
    Add a type that represents the set of warnings that may be disabled.

    This type cannot be in prog_item.m, because it is needed by the HLDS,
    and we don't want the HLDS to depend on prog_item.m.

compiler/parse_goal.m:
    Parse the new kind of goal, transforming it from source code to parse tree.

compiler/goal_expr_to_goal.m:
    Transform the new kind of goal from parse tree to HLDS.

compiler/prog_out.m:
compiler/parse_tree_out_clause.m:
compiler/hlds_out_goal.m:
    Output the new kinds of parse tree and HLDS goals.

compiler/make_hlds_warn.m:
    Disable singleton variable warnings when the new scope asks for that.

compiler/mark_tail_calls.m:
    Disable warnings about non-tail-recursive recursive calls
    when the new scope asks for that.

    Improve a warning message.

compiler/ml_tailcall.m:
    Document why this sort-of-duplicate implementation of the
    warnings about non-tail-recursive recursive calls cannot respect
    the new scope. (I believe this sort-of-duplicate code should be deleted.)

    Improve the same warning message as in mark_tail_calls.m.

compiler/constraint.m:
compiler/det_analysis.m:
compiler/det_report.m:
compiler/erl_code_gen.m:
compiler/get_dependencies.m:
compiler/goal_util.m:
compiler/hlds_desc.m:
compiler/interval.m:
compiler/lambda.m:
compiler/modecheck_goal.m:
compiler/module_qual.collect_mq_info.m:
compiler/polymorphism.m:
compiler/prog_item_stats.m:
compiler/prog_util.m:
compiler/purity.m:
compiler/quantification.m:
compiler/saved_vars.m:
compiler/simplify_goal_scope.m:
compiler/simplify_proc.m:
compiler/stm_expand.m:
compiler/switch_detection.m:
compiler/try_expand.m:
compiler/typecheck.m:
compiler/unique_modes.m:
    Handle the new kind of scope.

    In a couple of places, fix comments.

tests/invalid/require_tailrec_1.{m,err_exp}:
    Wrap a disable_warnings scope around one of the non-tail-recursive
    recursive calls we used to get a warning about, and expect that
    we don't get this warning anymore. (We still do get this warning in grades
    that use ml_tailcall.m instead of mark_tail_calls.m to generate such
    warnings, as mentioned above.)

    Specify Mercury syntax highlighting for the source file.
    Expect the improved wording of a warning.

tests/invalid/require_tailrec_2.{m,err_exp}:
    Specify Mercury syntax highlighting for the source file.
    Expect the improved wording of a warning.

tests/warnings/singleton_test.m:
    Add a test of a singleton variable whose warning is disabled.
2017-01-11 02:00:32 +11:00
Zoltan Somogyi
a0760327b6 Do stricter checking of mode and determinism declarations.
Specifically, we now do three new checks:

BAD_DETISM: We now generate error messages for predicate declarations
that specify a determinism without also specifying argument modes.

BAD_PREDMODE: We now generate error messages for standalone mode declarations
for predicates whose predicate declaration includes modes for the arguments.

BAD_MODE_SECTION: We now generate error messages for standalone mode
declarations that are not in the same section as the predicate's (or
function's) type declaration.

compiler/hlds_pred.m:
    Add a slot to the pred_sub_info. If the predicate is explicitly defined by
    the user in the current module, this contains the id of the section that
    contains its predicate declaration (for the BAD_MODE_SECTION check)
    and whether that predicate declaration also had modes for the arguments
    (for the BAD_PREDMODE check).

compiler/add_pred.m:
    When adding adding new predicate declarations, perform the BAD_DETISM
    check, and record the info needed for the BAD_PREDMODE and BAD_MODE_SECTION
    checks.

    When adding adding new mode declarations, perform the BAD_PREDMODE
    and BAD_MODE_SECTION checks.

compiler/add_class.m:
compiler/add_mutable_aux_preds.m:
compiler/add_pragma_tabling.m:
compiler/add_pragma_type_spec.m:
compiler/add_solver.m:
compiler/add_special_pred.m:
compiler/check_typeclass.m:
compiler/dep_par_conj.m:
compiler/higher_order.m:
compiler/make_hlds_passes.m:
compiler/table_gen.m:
compiler/unused_args.m:
    Conform to the changes above.

mdbcomp/builtin_modules.m:
    Add a utility predicate for use by new code in add_pred.m.

compiler/comp_unit_interface.m:
compiler/goal_util.m:
compiler/prog_rename.m:
compiler/quantification.m:
deep_profiler/program_representation_utils.m:
library/calendar.m:
library/mutvar.m:
library/pretty_printer.m:
library/random.m:
library/set_ctree234.m:
library/solutions.m:
library/stream.string_writer.m:
profiler/globals.m:
tests/accumulator/nonrec.m:
tests/accumulator/out_to_in.m:
tests/declarative_debugging/library_forwarding.m:
tests/dppd/applast_impl.m:
tests/dppd/grammar_impl.m:
tests/dppd/regexp.m:
tests/dppd/transpose_impl.m:
tests/hard_coded/copy_pred.m:
tests/hard_coded/ho_func_default_inst.m:
tests/recompilation/unchanged_pred_nr_2.m.1:
tests/recompilation/unchanged_pred_nr_2.m.2:
tests/valid/det_switch.m:
tests/valid/inlining_bug.m:
    Delete determinism declarations from predicate and function declarations
    that have no argument mode information, since the BAD_DETISM check
    now makes these errors.

tests/valid/two_pragma_c_codes.m:
    Move some mode declarations to the right section, since the
    BAD_MODE_SECTION check now generates an error for the old code.

tests/invalid/typeclass_bad_method_mode.{m,err_exp}:
    New test case to test for the BAD_PREDMODE check.

tests/invalid/mode_decl_in_wrong_section.{m,err_exp}:
    New test case to test for the BAD_MODE_SECTION check.

tests/invalid/bad_detism.err_exp:
    Add an expected output for this old, but never enabled test case,
    which tests for new check BAD_DETISM.

tests/invalid/Mmakefile:
    Enable the new test cases.

tests/invalid/typeclass_dup_method_mode.m:
    This test case used to have two bugs. One is now by itself in the new
    typeclass_bad_method_mode.m test case, so modify it to contain only
    the other (indistinguishable modes).

tests/invalid/func_errors.err_exp:
tests/invalid/tc_err1.err_exp:
tests/invalid/undef_lambda_mode.err_exp:
tests/invalid/undef_type_mode_qual.err_exp:
    Expect an extra error message from the BAD_DETISM check.
2016-01-13 02:03:16 +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
ae17b527c9 Convert (C->T;E) to (if C then T else E).
In goal_util.m, process all goal types in tests, not just some.

Some other simplifications.
2015-10-26 00:06:53 +11:00
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
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
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
3080515d3a Add require_switch_arms_{det,semidet,...} to the language.
The new construct looks like this:

    require_switch_arms_det [C] (
        (
            C = 'a',
            ... compute Out ...
        ;
            C = 'b',
            ... compute Out ...
        )
    )

If any of the goals computing Out are not det, the compiler will generate
an error message. The det at the end of the keyword can be replaced
by any of the other seven determinisms, though I don't think either
require_switch_arms_failure or require_switch_arms_erroneous will see much use.

This diff adds only the implementation. I will add the documentation
and the NEWS item after we all had a chance to install this diff and
try it out.

compiler/hlds_goal.m:
    Add a scope representing this kind of goal in the HLDS.

compiler/prog_item.m:
    Add a goal expression for this kind of goal in the parse tree.

compiler/prog_io_goal.m:
    Look for the new kind of goal expression in terms when creating
    the parse tree.

    Factor out some commonalities between the parsing of the new goal
    expression and existing types of goal expressions.

compiler/goal_expr_to_goal.m:
    Convert the new kind of goal expression to the new scope in the HLDS.

compiler/det_report.m:
    Implement the checks that the new goal type calls for.

    Factor out some commonalities between the implementation of the new goal
    type and existing goal types.

    Move the types and predicates dealing with comparisons of determinisms
    from here to prog_data.m, due to the sort-of-bugfix to modecheck_call.m.

compiler/prog_data.m:
    Move the types and predicates dealing with comparisons of determinisms
    from det_report.m to here. The old code for this was intended for only one
    requirement, and did not deal well with comparisons of two determinisms
    in which each determinism makes an assertion the other does not make.
    Create a way to represent such comparison results.

compiler/modecheck_call.m:
    When deciding which mode of a procedure to call, we prefer determinisms
    that make more assertions about solution counts. However, when comparing
    incomparable determinisms (such as semidet vs multi, each of which makes
    an assertion the other doesn't), the algorithm chose based solely
    on the ORDER of the modes. We now explicitly prefer modes that promise
    lower maximum solution counts, giving less importance to cannot_fail
    assertions.

compiler/*.m:
    Conform to the change to hlds_goal.m or prog_item.m.

library/ops.m:
    Add the new keywords as operators.

tests/hard_coded/require_scopes.{m,exp}:
    Extend this test case to test the new construct in the absence of errors.

tests/invalid/require_scopes.{m,exp}:
    Extend this test case to test the new construct in the presence of errors.
2014-11-14 12:46:46 +11:00
Zoltan Somogyi
e55ee1d838 Document the quant_warning type's reason for being.
compiler/quantification.m:
    As above.

compiler/make_hlds_warn.m:
    Give the predicates translating quant_warnings into actual error messages
    more meaningful names, and a more rational argument order.

compiler/add_class.m:
compiler/add_clause.m:
    Conform to the above.
2014-09-10 17:51:35 +02:00
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
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
Paul Bone
0e6792f106 Prepare to enable tail recursion in loop controlled code.
This patch prevents dep_par_conj.m from inserting get_future goals where they
are not necessary.  These goals where preventing tail recursion in examples
such as map_foldl (not the library predicate, but the one in our paper).

This patch also modifies the loop control scope reason, adding an extra field
that says if the spawned off code may use the parent stack or should setup a
new stack frame.

This patch makes it possible for Zoltan to begin contributing the missing parts
in the code generator.  Meanwhile I will work on the runtime system and the
par_loop_control.m code.

compiler/dep_par_conj.m:
    Don't insert calls to get_future if they're not needed.

    They prevent tail recursion from being possible and are not being optimized
    away.

compiler/hlds_goal.m:
    Add a new field to the loop_control scope reason, lc_use_parent_stack.
    This field is used to tell the code generator if it should generate
    references to the parent stack frame or if it should create a new stack
    frame on the child's stack.

compiler/code_gen.m:
compiler/par_conj_gen.m:
    Pass UseParentStack to the generate_loop_control predicate, and place some
    notes in this predicate about how to handle the different values of
    UseParentStack.

compiler/constraint.m:
compiler/det_analysis.m:
compiler/det_report.m:
compiler/erl_code_gen.m:
compiler/goal_util.m:
compiler/hlds_desc.m:
compiler/hlds_out_goal.m:
compiler/interval.m:
compiler/lambda.m:
compiler/make_hlds_warn.m:
compiler/modecheck_goal.m:
compiler/par_loop_control.m:
compiler/polymorphism.m:
compiler/quantification.m:
compiler/saved_vars.m:
compiler/simplify.m:
compiler/stm_expand.m:
compiler/try_expand.m:
compiler/typecheck.m:
compiler/unique_modes.m:
    Conform to changes in hlds_goal.m

compiler/live_vars.m:
    Conform to changes and make a revisit note about stack slot allocation when
    we don't use the parent's stack frame.

compiler/purity.m:
    Conform to changes and remove a revisit note.
2011-10-19 01:08:30 +00:00
Julien Fischer
cc6c1b38b7 Shift a construction unifiction so that it occurs after all its
Branches: main

compiler/quantification.m:
	Shift a construction unifiction so that it occurs after all its
	arguments have been produced.  (The compiler doesn't care but
	it does make this code quite difficult to read.)
2011-10-02 07:51:32 +00:00
Paul Bone
138ac7f0c4 Propose changes to the HLDS that are needed by the loop control transformation.
The loop control transformation will introduce code that needs to be executed
by a different context, This code will need to communicate with the context
that created it, for parallel conjunctions this is done using an extra stack
pointer, the parent stack pointer.  We've chosen to use the same communication
mechanism for loop control, this means that the code generator must generate
instructions that use the parent stack pointer instead of the normal stack
pointer.  A extra labels and a join_and_terminate call must also be inserted by
the code generator.

So that the code generator can do this we've introduced a new scope reason,
code that would be forked off will be contained within such a scope, informing
the code generator that special code needs to be generated.  The scope reason
also contains two variables, the loop control and loop control slot variables.
These variables are needed by the join and terminate code.

compiler/hlds_goal.m:
    Introduce new scope reason that marks code that must be handled differently
    during code generation Such code has had the loop control transformation
    applied to it and must be forked off to be executed on a different context.

compiler/constraint.m:
compiler/det_analysis.m:
compiler/det_report.m:
compiler/erl_code_gen.m:
compiler/goal_util.m:
compiler/hlds_desc.m:
compiler/hlds_out_goal.m:
compiler/interval.m:
compiler/lambda.m:
compiler/make_hlds_warn.m:
compiler/modecheck_goal.m:
compiler/polymorphism.m:
compiler/saved_vars.m:
compiler/simplify.m:
compiler/stm_expand.m:
compiler/try_expand.m:
compiler/typecheck.m:
compiler/unique_modes.m:
    Conform to changes in hlds_goal.m

compiler/purity.m:
    Merge switch alternatives that perform the same actions.

    Conform to changes in hlds_goal.m

compiler/quantification.m:
    Remove a complete switch whose branches are all no-ops.

    Conform to changes in hlds_goal.m
2011-09-13 06:07:15 +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
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
d751977fca Change the argument order of predicates in the tree_bitset module to make it
Branches: main

Change the argument order of predicates in the tree_bitset module to make it
more conducive to the use of state variable notation.

library/tree_bitset.m:
	As above.

	Add the usual modes with (mostly-)unique accumulators
	to foldl/4.

compiler/quantification.m:
	Conform to the above change.

NEWS:
	Announce the above change.
2011-05-19 16:20:55 +00:00
Zoltan Somogyi
022b559584 Make error messages for require_complete_switch scopes report the missing
Estimated hours taken: 8
Branches: main

Make error messages for require_complete_switch scopes report the missing
functors.

Knowing which functors are missing requires knowing not only the set of
functors in the switched-on variable's type, but also which of these functors
have been eliminated by earlier tests, which requires having the instmap at
the point of entry to the switch. Simplification, which initially detected
unmet require_complete_switch requirements, does not have the instmap, and
threading the instmap through it would make it significantly less efficient.
So instead we now detect any problems with require_complete_switch scopes
(and require_detism scopes, which are similar) during determinism checking.

compiler/det_report.m:
	Factor out the code for finding the missing functors in conventional
	determinism errors, to allow it to be used for this new purpose.

	Check whether the requirements of require_complete_switch and
	require_detism scopes are met IF the predicate has any such scopes.

compiler/det_analysis.m:
compiler/det_util.m:
	Record whether the predicate has any such scopes.

compiler/hlds_pred.m:
	Add a predicate marker that allows this recording.

compiler/simplify.m:
	Delete the code that checks the require_complete_switch and
	require_detism scopes. Keep the code that deletes those scopes.
	(We have to do that here because determinism error reporting
	never updates the goal).

compiler/prog_out.m:
	Delete an unused predicate.

compiler/*.m:
	Remove unnecesary imports as flagged by --warn-unused-imports.
2011-01-02 14:38:08 +00:00
Zoltan Somogyi
e77bcdc4ba Add two new kinds of scopes to the language: one that requires the goal inside
Estimated hours taken: 12
Branches: main

Add two new kinds of scopes to the language: one that requires the goal inside
the scope to have a given determinism, and one that requires it
to be complete, i.e. to have arms for all the function symbols in the type of
the switched-on variable.

The first kind of scope adds the keywords

	require_det require_semidet
	require_multi require_nondet
	require_cc_multi require_cc_nondet
	require_erroneous require_failure

to the language. They are intended to be used like this:

	test_detism_scope(A, !IO) :-
	    (
		A > 10,
		require_det (
		    B = A * 2,
		    C = B mod 3
		),
		C = 1
	    ->
		X = C
	    ;
		X = A
	    ),
	    io.format("test_detism_scope(%d) = %d\n", [i(A), i(X)], !IO).

The second kind of scope adds the keyword require_complete_switch to
the language. They are intended to be used like this:

	do_test_switch_scope(A, X) :-
	    require_complete_switch [A] (
		(
		    A = f1,
		    fail
		;
		    A = f2,
		    ( X = 1
		    ; X = 2
		    )
		;
		    A = f3(B),
		    ( X = 3
		    ; X = B
		    ; X = B + 1
		    )
		)
	    ).

NEWS:
	Announce the new scopes.

doc/reference_manual.texi:
	Document the new scopes.

library/ops.m:
	Add the new keywords as operators.

compiler/hlds_goal.m:
	Add the new kinds of scopes to the HLDS.

compiler/prog_item.m:
	Add the new kinds of scopes to the parse tree type.

compiler/prog_io_goal.m:
	Recognize the new keywords. When we find a term with one of these
	keywords as the function symbol, generate the corresponding parse tree
	goal expression.

compiler/add_clause.m:
	Convert these goal expressions to HLDS.

compiler/simplify.m:
	Check the requirements expressed by the new scopes. If the requirement
	is met, delete the scope wrapper. If the requirement is not met,
	generate an error message and then delete the scope wrapper.

compiler/error_util.m:
	Add a new format_component, words_qoute, which is like quote, but
	yields words, not fixed, after quoting.

compiler/constraint.m:
compiler/det_analysis.m:
compiler/erl_code_gen.m:
compiler/goal_util.m:
compiler/hlds_desc.m:
compiler/hlds_out_goal.m:
compiler/interval.m:
compiler/lambda.m:
compiler/make_hlds_warn.m:
compiler/mercury_to_mercury.m:
compiler/mode_errors.m:
compiler/modecheck_goal.m:
compiler/module_imports.m:
compiler/module_qual.m:
compiler/polymorphism.m:
compiler/prog_util.m:
compiler/purity.m:
compiler/quantification.m:
compiler/saved_vars.m:
compiler/stm_expand.m:
compiler/try_expand.m:
compiler/typecheck.m:
	Conform to the changes to the parse tree and HLDS goal types.
	In one module, take advantage of the new format_component.

tests/hard_coded/require_scopes.{m,exp}:
	A new test case to test the handling of the new scopes when their
	requirements are met.

tests/hard_coded/Mmakefile:
	Add the new test.

tests/invalid/require_scopes.{m,err_exp}:
	A new test case to test the handling of the new scopes when their
	requirements are NOT met.

tests/invalid/Mmakefile:
	Add the new test.
2010-12-29 04:52:23 +00:00
Zoltan Somogyi
8a28e40c9b Add the predicates sorry, unexpected and expect to library/error.m.
Estimated hours taken: 2
Branches: main

Add the predicates sorry, unexpected and expect to library/error.m.

compiler/compiler_util.m:
library/error.m:
	Move the predicates sorry, unexpected and expect from compiler_util
	to error.

	Put the predicates in error.m into the same order as their
	declarations.

compiler/*.m:
	Change imports as needed.

compiler/lp.m:
compiler/lp_rational.m:
	Change imports as needed, and some minor cleanups.

deep_profiler/*.m:
	Switch to using the new library predicates, instead of calling error
	directly. Some other minor cleanups.

NEWS:
	Mention the new predicates in the standard library.
2010-12-15 06:30:36 +00:00
Zoltan Somogyi
4aaaabf847 Fix an inadvertent commit of a change neded only for debugging,
Estimated hours taken: 0.1
Branches: main

compiler/quantification.m:
	Fix an inadvertent commit of a change neded only for debugging,
	which made quantification use the readable but slow set_ordlist,
	instead of the fast tree_bitset implementation of sets.
2010-10-01 08:09:05 +00:00
Zoltan Somogyi
ea2240197f Note a problem with our current data structure design.
Estimated hours taken: 1
Branches: main

compiler/hlds_rtti.m:
	Note a problem with our current data structure design.

compiler/hlds_rtti.m:
compiler/quantification.m:
	Fix some issues of programming style.
2010-09-15 07:02:01 +00:00
Peter Wang
9f17a8ef60 Fix some problems with `atomic' scopes. In particular, state variables in
Branches: main

Fix some problems with `atomic' scopes.  In particular, state variables in
atomic scopes now works (again?)

compiler/hlds_goal.m:
compiler/saved_vars.m:
        Add a goal feature to indicate when a goal within an atomic scope has
        stm_from_outer_to_inner/stm_from_inner_to_outer calls added.

compiler/quantification.m:
        Add a predicate to quantify goals inside an atomic scope.
        Quantification may occur before the calls to stm_from_*_to_* are
        inserted.  If that is not taken into account, the nonlocal set for
        an atomic goal won't include its inner interface variables, causing
        problems (e.g. variables being renamed away).

        Don't explicitly delete inner variables from the nonlocal vars of
        atomic scope; this has no effect.  [Also, it only deleted the inner
        variables for the main atomic goal.  The inner variables of the or_else
        goals probably needed to be deleted as well.]

compiler/purity.m:
        Remove code that checks STM inner variables are not used outside of the
        atomic scope, and outer variables not used within.  The changes in
        quantification.m broke the assumption that inner variables don't appear
        in the nonlocals of their respective atomic goals.  Mode checking
        should catch the same errors anyway.

        Add the new goal feature after inserting stm_from_*_to_* calls.

compiler/state_var.m:
        In svar_start_inner_atomic_scope, return the "dot" variable as inner
        `di' variable.  Before, it returned the "colon" variable which resulted
        in an incorrect ordering in the expanded goal.

        In svar_finish_inner_atomic_scope, use the "dot" variable as the
        inner `uo' variable.

compiler/typecheck.m:
        Unify the types of the outer variables on an atomic scope.

tests/stm/Mmakefile:
tests/stm/atomic_conj.exp:
tests/stm/atomic_conj.m:
tests/stm/atomic_ite.exp:
tests/stm/atomic_ite.m:
        Add test cases.
2009-11-06 02:22:02 +00:00
Zoltan Somogyi
69644fa7c7 Fix three bugs with from_ground_term scopes, including Mantis bugs 93 and 94.
Estimated hours taken: 14
Branches: main

Fix three bugs with from_ground_term scopes, including Mantis bugs 93 and 94.

compiler/superhomogenenous.m:
	Fix Mantis bug 94. The problem was an overzealous sanity check.

compiler/modes.m:
	Fix Mantis bug 93. When analysing a from_ground_term_construct scope,
	we set the inst of the var being built to ground, since the shared
	nature of static terms requires this. However, some code may require
	the term to be unique. We therefore prepare to do mode analysis twice.
	On the first pass, we consider terms from from_ground_term to be
	ground, as before, but we record the fact that we did so. If
	mode analysis of the procedure yields one or more errors, they could
	have been due to this decision. So we analyze the procedure a second
	time, but this time, after each from_ground_term_construct scope,
	we add a call to builtin.copy, which yields a unique term.

	Note that this may be overkill. Even if e.g. the procedure has three
	from_ground_term_construct scopes, only one of which need to be unique
	for mode analysis to succeed, we will call copy after all three.

compiler/mode_info.m:
	Provide the infrastructure for the fix in modes.m.

compiler/quantification.m:
	Fix the third bug, which is not in Mantis. The bug was that after my
	recent optimization of quantification, we never listed the local
	variables of from_ground_term_construct scopes in the outputs of the
	goal_vars_* family of predicates. However, there is one case where they
	are needed, and this is when we want to duplicate the goal, and need to
	rename *all* the variables in the copy.

	The fix is to add new versions of goal_vars_* and their auxiliary
	predicates that collect this information, and use them when expanding
	out bi_implications.

	This now also expects that bi_implications won't occur in the hLDS
	by the time that lambda expansion has been done. Since lambda expansion
	is done in the middle pass, and bi_implications are expanded out by the
	very first invocation of quantification, even *before* semantic
	analysis starts, this is a safe bet.

compiler/hlds_goal.m:
	Document where bi_implications are expanded out.

compiler/polymorphism.m:
	Minor style improment.

compiler/options.m:
	Set the default from_ground_term threshold to what it was before
	we discovered these problems.

tests/hard_coded/uo_regression1.{m,exp}:
tests/hard_coded/from_ground_term_bug.{m,exp}:
	Slightly modified versions of the Mantis test cases for bugs 93 and 94.

tests/hard_coded/type_qual.{m,exp}:
	This test case was the one that shows the third bug. Expand it
	to put a from_ground_term_construct scope in the LHS as well as RHS
	of a bi-implication.

tests/hard_coded/Mmakefile:
tests/hard_coded/Mercury.options:
	Enable the two new tests, and enable from_ground_term_construct scopes
	on all three tests.
2009-09-22 07:34:20 +00:00
Zoltan Somogyi
77a6a6c10c Implement several more changes that together speed up compilation time
Estimated hours taken: 16
Branches: main

Implement several more changes that together speed up compilation time
on training_cars_full by 12%, and also improve tools/speedtest -h by 7.2%
and tools/speedtest by 1.6%.

The first change is designed to eliminate the time that the compiler spends
constructing error messages that are then ignored. The working predicates of
prog_io_sym_name used to always return a single result, which either gave
a description of the thing being looked, or an error message. However,
in many places, the caller did not consider not finding the thing being looked
for to be an error, and thus threw away the error message, keeping only
the "not found" indication. For each predicate with such callers, this diff
provides a parallel predicate that indicates "not found" simply by failing.
This allows us to eliminate the construction of the error message, the
preparation for the construction of the error message (usually by describing
the context), and the construction of the "ok" wrapper.

The second change is to specialize the handling of from_ground_term_construct
scopes in the termination analyzer. To make this easier, I also cleaned up
of the infrastructure of the termination analyzer.

The third change is to avoid traversing from_ground_term_construct scopes
in quantification.m when finding the variables in a goal, since termination
analysis no longer needs the information it gathers.

The fourth change is to avoid traversing second and later conjuncts in
conjunctions twice. The first step in handling conjunctions is to call
implicitly_quantify_conj, which builds up a data structure that pairs each
conjunct with the variables that occur free in all the conjuncts following it.
However, after this was done and each conjunct was annotated with its
nonlocals, we used to compute the variables that occur free in the conjunction
as a whole from scratch. This diff changes the code so that we now compute that
set based on the information we gathered earlier, avoiding a redundant
traversal.

The fifth change is to create specialized, lower-arity versions of many of
the predicates in quantification.m. These versions are intended for traversals
that take place after the compiler has replaced lambda expressions with
references to separate procedures. These traversals do not need to pass around
arguments representing the variables occurring free in the (now non-existent)
lambda expressions.

compiler/prog_io_sym_name.m:
	Make the first change described above.

	Change some predicate names to adopt a consistent naming scheme
	in which predicates that do the same job and differ only in how they
	handle errors have names that differ only in a "try_" prefix.

	Add some predicate versions that do common tests on the output
	of the base versions. For example, try_parse_sym_name_and_no_args
	is a version of try_parse_sym_name_and_args that insists on finding
	an empty argument list.

	Remove the unused "error term" argument that we used to need a while
	ago.

	Move some predicate definitions to make their order match the order of
	their declarations.

	Turn a predicate into a function for its caller's convenience.

compiler/term_constr_build.m:
	Make the second change described above by modeling each
	from_ground_term_construct scope as a single unification,
	assigning the total size of the ground term to the variable being
	built.

compiler/term_constr_util.m:
	Put the arguments of some predicates into a more standard order.

compiler/lp_rational.m:
	Change the names of some function symbols to avoid both the use of
	graphic characters that require quoting and clashes with other types.

	Change the names of some predicates to make their purpose clear,
	and to avoid ambiguity.

compiler/quantification.m:
	Make the third, fourth and fifth changes described above.

compiler/*.m:
	Conform to the changes above.
2009-09-08 02:43:41 +00:00
Zoltan Somogyi
cc9423e35d Rationalize the way the MLDS code generator handles global data structures.
Estimated hours taken: 80
Branches: main

Rationalize the way the MLDS code generator handles global data structures.
The previous way was somewhat perverse in several respects.

The first respect was that static Mercury terms were translated into global
MLDS definitions, those MLDS definitions were turned into local definitions,
and then later turned back into global definitions. However, while they were
local definitions, they were part of the list of definitions processed
by ml_elim_nested. Since the complexity of ml_elim_nested is at least O(n^2)
and probably O(n^3) or worse, and since the definitions representing static
terms could increase the value of n from dozens or hundred to many thousands,
this was a BAD IDEA, especially since by construction, the MLDS definitions
representing ground terms cannot have other definitions nested inside them.
This problem was the main reason why previously the compiler took effectively
forever to compile any program with large tables of facts in MLDS grades.

The second respect has to do with the fact that terms are represented as tagged
pointers to memory cells. When generating an MLDS definition (a static cell)
for a ground term, ml_unify_gen.m remembered the name of the MLDS variable
representing the static cell, but forgot the tag on the pointer. So when
that ground term was used as an argument in another, bigger ground term,
it had to figure out the tag all over again. The argument of the
construct_statically functor in construct unifications had as its sole purpose
the provision of the data needed by this recomputation.

The third respect was that the code generator could generate duplicate
definitions (same variable name, same content) when two conjoined goals
referred to two or more type_infos or pseudo_type_infos for the same type.
The code generator used to handle it by wrapping a scope around the later
definitions, which (a) wasted memory, and (b) could yield warnings from
the C compiler about shadowed declarations. This problem used to prevent
the compiler from bootchecking in grade hlc_nest.gc; with this diff,
we can again bootcheck in grade hlc_nest.gc.

The fourth respect was that the code generator's record of which variables are
bound to constant terms was inaccurate, because it was never reset. If a
variable was bound to a constant term in one branch of a control structure,
the MLDS code generator state's record of this binding was still there
when the compiler generated code for the later branches of that control
structure. It did not use the record, but it was still there.

The MLDS code generator also used a horribly inefficient algorithm for figuring
out which Mercury variables should have their corresponding MLDS variables
declared at a given goal. It gathered up all the goals's variables, and then
gathered up all the variables in the goal's immediate subgoals. This meant
that the entire goal had to be traversed TWICE, with the second traversal
being needed only because the first one gathered too much information.
Those traversals were a huge performance problem on programs with large static
terms, since their representation is large conjunctions of unifications,
which have large numbers of variables. To add insult to injury, the traversals
used ordered lists to represent the sets, which meant that (given the ascending
variable numbers in from_ground_term scopes), adding the n'th unification's
new variable to the set took O(n) time, with the complexity of the whole
algorithm being quadratic.

Besides fixing these problems, this diff makes the MLDS code generator
handle from_ground_term_construct scopes specially, in a streamlined fashion,
just as the LLDS backend has done for a while now. It also fixes a bunch
of other performance problems pointed out by profiling.

This diff reduces the compilation time on the training_cars_150.m benchmark,
which has nothing but ground terms, from 94+ seconds to less than 2 seconds,
a 98% speedup. (This is with from_ground_term scopes enabled, as is
appropriate.) For ordinary programs, compilation time in grade hlc.gc
is reduced by about 3%.

compiler/ml_global_data.m:
	A new module that manages the MLDS code generator's records about
	static definitions. It separates those definitions into different
	categories based on what kind of processing they need. At the moment,
	the categories are: definitions of cells for ground terms and
	definitions of cells for RTTI, with the latter being subdivided
	into those that may need to be processed by ml_elim_nested
	and those that are known not to need such processing.

	It also records whether we have generated representation for a
	type_info or pseudo_type yet, so that we can avoid generating duplicate
	definitions. This, and the code that uses this, fixes the third
	problem.

compiler/ml_backend.m:
compiler/notes/compiler_design.html:
	Add the new module.

compiler/goal_util.m:
	Add a warning about the bad complexity of goal_vars.

compiler/hlds_goal.m:
	Remove the static_cons type, since it is no longer needed.
	Remove the static_cons argument of the construct_statically
	functor of the how_to_construct type.

	Fix an out-of-date comment about from_ground_term scopes.

compiler/mark_static_terms.m:
	Change the data structure being threaded through this module
	from being a map(prog_var, static_cons) to a set_tree234(prog_var),
	since we no longer need the information stored in static_conses.

compiler/modes.m:
	Do not compute static_conses.

compiler/mlds.m:
	Put the information about global data into a separate field of
	the MLDS, since some classes of such data can have their treatment
	optimized.

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

	Give some function symbol names prefixes to avoid ambiguities.

	Change or add some field name prefixes to avoid ambiguities.

	Avoid the unnecessary use of higher order code in handling the flags of
	MLDS definitions. The new code is simpler as well as faster than the
	old.

compiler/ml_code_util.m:
	Make ml_global_data a part of the MLDS code generator state. This
	allows a bunch of predicates in the MLDS code generator to no longer
	return lists of definitions, since those definitions are now put
	into this new part of ml_gen_info, which ml_elim_nested won't touch.
	This is part of the solution of the first problem.

	Replace the field that mapped vars to the name of the global static
	definition involved in representing the ground term bound to that var
	with a field that maps the var to the actual rval (which will be a
	tagged pointer to that static definition), though we also remember
	the variable's type, since this is needed for making decisions about
	boxing. This is part of the solution for the second problem.

	Rename the extra_defns field of the ml_gen_info to the
	closure_wrapper_defns field, since this is the only thing that
	it is used for.

	Add fields to the ml_gen_info holding the value of the --highlevel-data
	option and the compilation target, since these are needed very often,
	and looking them up in the globals is too slow.

	Access all fields of ml_gen_info via access predicates, not via field
        notation, so that the number of accesses to each field can be measured
        by deep profiling.

        Separate the ml_gen_info structure into a main structure whose fields
        are frequently updated and which fits into an 8-word block of memory,
        and a substructure whose fields are read-only or rarely updated.
        This should help improve memory performance.

	Provide more useful access predicates to some of the counters,
	and make them harder to confuse by using fewer type synonyms.

	Provide some more convenient predicates for creating auxiliary MLDS
	variables (those that do not correspond to Mercury variables).

	Delete ml_join_decls, since fixing the third problem means that it is
	no longer needed.

	Delete some other predicates whose job has been taken over by
	ml_global_data.m.

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

	Rename some predicates to avoid ambiguities.

compiler/ml_code_gen.m:
	As part of the fix for the repeated traversals of parts of the
	procedure body with goal_vars, we now have to run quantification
	before generating MLDS for a procedure. Quantification does in
	one optimized pass what the old code used to do in many unoptimized
	passes. However, since quantification can change the HLDS, this
	requires a small change in the module's interface. HLDS dump 499
	now dumps to the HLDS version *output* by MLDS code generation,
	not the HLDS version that is its input.

	Use the (now guaranteed accurate) nonlocals fields of the goal and
	its immediate subgoals to figure out what variables need to declared at
	each goal. This fixes the fifth problem.

	Special case from_ground_term_construct scopes. (This code recognizes
	such scopes; the code that handles them is in ml_unify_gen.m.)

	Use trace goals to print progress messages.

	Avoid the use of io.format and string.format (see below).

	Group the predicates of this module a bit more meaningfully.
	(A really good order requires more reordering, but that will be
	a separate change.)

	Give some predicates more meaningful names.

	Add predicates that allow the convenient implementation of branched
	control structures.

	Use them in the implementation of the branched control structures
	handled in this module

	Together, these solve the fourth problem.

compiler/ml_switch_gen.m:
compiler/ml_string_switch.m:
	Use them in the implementation of the branched control structures
	handled in these modules.

	Use the new module to generate constant data.

compiler/ml_unify_gen.m:
	Implement the changes described at the top.

	Divide ml_gen_new_object, a predicate that used to be 220 lines long,
        into several pieces, one for each different method of constructing new
	objects (memory cells).

	Delete the (extensive) code that used to recreate the tags on
	pointers to static cells. This code used to also recreate static
	arguments in their entirety if they were NOT pointers to cells,
	e.g. if they were integers or floats or strings, so we now record
	the values of such non-tagged-pointer constant terms also.

	Put the arguments of some predicates into a more logical order.
	In addition, some predicates now need ml_global_data threaded through
	them, but avoid returning lists of definitions.

compiler/ml_call_gen.m:
	Simplify the interface of the predicate that decides on boxing and
	unboxing, making it callable from places that do not have a full code
	generator state (such as the streamlined code in ml_unify_gen handling
	from_ground_term_construct scopes).

	Avoid the unnecessary use of higher order code.

	Rename a predicate to avoid ambiguity.

compiler/ml_closure_gen.m;
	Generate the closure layout information as static global data.

compiler/ml_elim_nested.m:
	Thread the globals through this module instead of the I/O state,
	since the only thing the I/O state was used for was accessing the
	globals.

	Traverse only the small subset of global data that needs to be
	traversed.

compiler/ml_type_gen.m:
	Use trace goals to print progress messages.

	Replace a semidet predicate  with a function returning a tailored type,
	for improved robustness.

	Look up stuff in the globals structure less frequently, by reusing the
	results of past lookups.

compiler/rtti_to_mlds.m:
	Restructure the code in this module in two respects.

	First, instead of having predicates returning lists of
	MLDS definitions, make them add those definitions to a ml_global_data
	data structure threaded through the module. Since the ml_global_data
	structure records which type_infos and pseudo_type_infos we have
	already generated definitions for, this allows us to avoid generating
	duplicate static cells for them. This allows us to avoid the old
	code's roundabout way of handling of such cells.

	Second, several predicates of this module returned initializers,
	which their caller then stuck into a static definition. This diff
	changes things so that wherever possible, the predicate that computes
	the initializers also creates the cell definition. This improves the
	code's cohesion.

	Also, rename some predicates where, after the above changes, their old
	names are no longer appropriate.

compiler/mlds_to_c.m:
	Avoid the use of io.format and string.format, since (after the more
	extensive changes described at the top of this log message) this
	turned out to account for a nontrivial percentage of the compiler's
	runtime.

	Instead of repeatedly looking up the values of some options
	in a copy of the globals obtained from the I/O state, thread
	through this module a term that records all the information
	that this module needs from globals.

	Threading this data through this module instead of looking something
	upo in the I/O state leads to a slight slowdown, but not having to do
	option lookups in large trees leads to a larger speedup.

	Rename some predicates to ambiguity.

	Convert some predicate definitions from multiple clauses into one,
	for clarity.

	Conform to the changes in the structure of the MLDS.

compiler/mlds_to_gcc.m:
	Conform to the changes in the structure of the MLDS.

compiler/mlds_to_il.m:
compiler/mlds_to_ilasm.m:
compiler/mlds_to_java.m:
compiler/mlds_to_managed.m:
	Conform to the changes in the structure of the MLDS.

	Pass the globals to this module instead of looking it up in the
	I/O state.

	Rename some predicates to ambiguity.

	Avoid the unnecessary use of higher order code.

	In mlds_to_managed.m, thread a previously frequently-looked-up value
	through the module.

compiler/typecheck_info.m:
	The code for expanding equivalence types in a procedure's vartypes
	field used to iterate on the keys of the vartypes map, and then
	looked up the associated values in the map. This diff replaces hat
	with new code that iterates on an association list that puts the
	value right next to its key (a list that the old code just threw away).

	The var/type assoc list we compute is still sorted on the variables,
	so create the new vartypes map not by repeated insertion, but
	directly (using map.from_sorted_assoc_list).

compiler/purity.m:
	Add a note about a possible future speedup.

compiler/prog_io_sym_name.m:
	Rename a predicate to avoid an ambiguity, and to make its purpose
	clearer.

compiler/globals.m:
compiler/handle_options.m:
compiler/mlds_to_il.m:
	Check whether the mmc option that specifies the IL version number is
	well formed at the start of the compilation, in handle_options.m,
	when all the other option values are checked if needed, rather than
	when generating IL code. This way, we can generate an error message,
	not a compiler abort.

	The IL version number is now recorded in the globals structure.

compiler/make_hlds_warn.m:
	Do not descend into from_ground_term scopes, since by construction,
	they cannot contain singleton variables.

compiler/analysis.file.m:
compiler/deep_profiling..m:
compiler/field_access.m:
compiler/hlds_out.m:
compiler/interval.m:
compiler/liveness.m:
compiler/loop_inv.m:
compiler/make.module_dep_file.m:
compiler/mercury_compile.m:
compiler/loop_inv.m:
compiler/ml_tailcall.m:
compiler/module_qual.m:
compiler/prog_ctgc.m:
compiler/prog_io_dcg.m:
compiler/prog_io_goal.m:
compiler/prog_io_pragma.m:
compiler/prog_io_typeclass.m:
compiler/prog_io_util.m:
compiler/quantification.m:
compiler/rbmm.add_rbmm_goal_infos.m:
compiler/recompilation.check.m:
compiler/recompilation.version.m:
compiler/structure_reuse.indirect.m:
compiler/superhomogeneous.m:
compiler/var_locn.m:
	Conform to the changes above.

compiler/unused_args.m:
	Fix an ambiguous predicate name.

tests/hard_coded/float_field.{m,exp}:
	Add some more test situations to this test case. These test
	the handling of notag types in static terms more thoroughly
	than before.
2009-09-02 00:30:35 +00:00