Commit Graph

33 Commits

Author SHA1 Message Date
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
404fea1bd2 Start removing non-var_table versions of predicates.
compiler/arg_info.m:
compiler/goal_util.m:
compiler/hlds_rtti.m:
compiler/instmap.m:
compiler/recompute_instmap_deltas.m:
compiler/type_util.m:
    For predicates which had both varset/vartypes and var_table versions,
    but the former is not used anymore because all its callers have been
    switched to the latter,

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

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

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

compiler/accumulator.m:
compiler/call_gen.m:
compiler/code_loc_dep.m:
compiler/constraint.m:
compiler/deforest.m:
compiler/delay_construct.m:
compiler/dep_par_conj.m:
compiler/det_analysis.m:
compiler/det_util.m:
compiler/float_regs.m:
compiler/follow_code.m:
compiler/higher_order.m:
compiler/interval.m:
compiler/lambda.m:
compiler/lco.m:
compiler/live_vars.m:
compiler/liveness.m:
compiler/loop_inv.m:
compiler/ml_code_gen.m:
compiler/modes.m:
compiler/pd_info.m:
compiler/pd_util.m:
compiler/push_goals_together.m:
compiler/rbmm.region_liveness_info.m:
compiler/saved_vars.m:
compiler/simplify_goal.m:
compiler/simplify_proc.m:
compiler/size_prof.m:
compiler/ssdebug.m:
compiler/structure_reuse.indirect.m:
compiler/structure_reuse.lbu.m:
compiler/structure_reuse.lfu.m:
compiler/table_gen.m:
compiler/tupling.m:
compiler/unneeded_code.m:
compiler/untupling.m:
    Conform to the changes above.
2022-05-15 21:40:10 +10:00
Zoltan Somogyi
d667194642 Introduce a new type for effective trace levels.
We have two main notions of trace levels. The first is the global trace level,
which is set by compiler options, and the second is the effective trace level
for a given procedure. The two are different not just in that the effective
trace level for a procedure may differ from the global trace level, but also
in that there exist effective trace levels that cannot be specified using
compiler options.

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

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

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

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

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

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

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

    Conform to the changes above.

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

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

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

compiler/hlds_out_module.m:
    Simplify some code.

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

    In many predicates, fix argument order.

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

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

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

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

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

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

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

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

    Define the var_name_source type.

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

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

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

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

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

    Fix some comments.

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

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

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

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

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

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

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

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

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

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

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

    Conform to the change above.

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

    Conform to the change above.

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

    Conform to the change above.

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

    Conform to the change above.

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

    Conform to the change above.

compiler/accumulator.m:
compiler/add_heap_ops.m:
compiler/add_trail_ops.m:
compiler/arg_info.m:
compiler/build_mode_constraints.m:
compiler/bytecode_gen.m:
compiler/call_gen.m:
compiler/clause_to_proc.m:
compiler/closure_analysis.m:
compiler/code_gen.m:
compiler/code_loc_dep.m:
compiler/complexity.m:
compiler/continuation_info.m:
compiler/cse_detection.m:
compiler/ctgc.datastruct.m:
compiler/ctgc.util.m:
compiler/deep_profiling.m:
compiler/deforest.m:
compiler/delay_construct.m:
compiler/delay_partial_inst.m:
compiler/dep_par_conj.m:
compiler/det_analysis.m:
compiler/direct_arg_in_out.m:
compiler/disj_gen.m:
compiler/equiv_type_hlds.m:
compiler/exception_analysis.m:
compiler/float_regs.m:
compiler/follow_code.m:
compiler/goal_mode.m:
compiler/goal_path.m:
compiler/hlds_out_pred.m:
compiler/hlds_rtti.m:
compiler/hlds_statistics.m:
compiler/inlining.m:
compiler/intermod.m:
compiler/intermod_analysis.m:
compiler/introduce_exists_casts.m:
compiler/introduce_parallelism.m:
compiler/lambda.m:
compiler/lco.m:
compiler/live_vars.m:
compiler/loop_inv.m:
compiler/mark_tail_calls.m:
compiler/ml_accurate_gc.m:
compiler/ml_args_util.m:
compiler/ml_closure_gen.m:
compiler/ml_gen_info.m:
compiler/ml_proc_gen.m:
compiler/mode_info.m:
compiler/modecheck_goal.m:
compiler/modes.m:
compiler/par_loop_control.m:
compiler/pd_debug.m:
compiler/pd_info.m:
compiler/pd_util.m:
compiler/polymorphism_info.m:
compiler/proc_gen.m:
compiler/purity.m:
compiler/push_goals_together.m:
compiler/quantification.m:
compiler/rbmm.add_rbmm_goal_infos.m:
compiler/rbmm.live_variable_analysis.m:
compiler/rbmm.points_to_graph.m:
compiler/rbmm.points_to_info.m:
compiler/rbmm.region_liveness_info.m:
compiler/rbmm.region_transformation.m:
compiler/recompute_instmap_deltas.m:
compiler/saved_vars.m:
compiler/simplify_goal_unify.m:
compiler/simplify_info.m:
compiler/simplify_proc.m:
compiler/size_prof.m:
compiler/ssdebug.m:
compiler/stack_alloc.m:
compiler/stack_layout.m:
compiler/stack_opt.m:
compiler/stm_expand.m:
compiler/store_alloc.m:
compiler/structure_reuse.analysis.m:
compiler/structure_reuse.direct.choose_reuse.m:
compiler/structure_reuse.direct.detect_garbage.m:
compiler/structure_reuse.indirect.m:
compiler/structure_reuse.lbu.m:
compiler/structure_reuse.lfu.m:
compiler/structure_sharing.analysis.m:
compiler/structure_sharing.domain.m:
compiler/switch_detection.m:
compiler/table_gen.m:
compiler/tabling_analysis.m:
compiler/term_constr_build.m:
compiler/term_constr_initial.m:
compiler/term_errors.m:
compiler/term_pass1.m:
compiler/term_pass2.m:
compiler/trace_gen.m:
compiler/trailing_analysis.m:
compiler/try_expand.m:
compiler/tupling.m:
compiler/unneeded_code.m:
compiler/untupling.m:
compiler/unused_args.m:
compiler/unused_imports.m:
    Conform to the change above.
2022-04-07 21:22:21 +10:00
Zoltan Somogyi
361c42caef Put predicates' args into a better order.
compiler/continuation_info.m:
    As above: put bigger inputs before smaller ones.

compiler/code_loc_dep.m:
compiler/proc_gen.m:
compiler/trace_gen.m:
    Conform to the changes above.
2022-03-28 12:23:59 +11:00
Zoltan Somogyi
99fa99fffe Use var_table.m in the LLDS code generator.
compiler/code_info.m:
    Replace the varset and vartypes fields of the code_info with a var_table.

compiler/var_table.m:
    Add some routines to format variable names in various ways.

compiler/arg_info.m:
    Delete an unneeded vartypes argument from a predicate.

    For some other predicates that took vartypes, create versions
    that take var_tables instead. Simplify the code of some of the
    duplicated predicates.

    Where some predicates took lists of variable and lists of their types,
    modify them to take either a vartypes or a var_table argument instead
    (in different versions). This

    - saves the memory needed for the list of types,
    - saves the traversal needed to build the list of types, and
    - avoids the possibility of a length mismatch between the two lists.

compiler/call_gen.m:
compiler/closure_gen.m:
compiler/code_gen.m:
compiler/code_loc_dep.m:
compiler/disj_gen.m:
compiler/follow_vars.m:
compiler/hlds_llds.m:
compiler/interval.m:
compiler/lco.m:
compiler/lookup_switch.m:
compiler/middle_rec.m:
compiler/ml_code_util.m:
compiler/pragma_c_gen.m:
compiler/proc_gen.m:
compiler/rbmm.region_liveness_info.m:
compiler/switch_gen.m:
compiler/trace_gen.m:
compiler/tupling.m:
compiler/type_util.m:
compiler/unify_gen_construct.m:
compiler/unify_gen_deconstruct.m:
    Conform to the changes above.
2022-03-28 11:36:49 +11:00
Zoltan Somogyi
8ebe125a6a Introduce var_table.m.
Most compiler passes need to know both the names and the types
of the variables they operate on. Until now, they had to pass along
two separate data structures for that, the varset and the vartypes,
and many operations required looking a variable up in both of these.

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

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

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

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

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

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

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

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

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

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

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

    Give some predicates more meaningful names.

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

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

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

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

compiler/closure_gen.m:
compiler/code_info.m:
compiler/code_loc_dep.m:
compiler/export.m:
compiler/lambda.m:
compiler/live_vars.m:
compiler/liveness.m:
compiler/llds.m:
compiler/llds_out_instr.m:
compiler/mark_tail_calls.m:
compiler/opt_debug.m:
compiler/opt_util.m:
compiler/stack_alloc.m:
compiler/stack_layout.m:
compiler/tag_switch.m:
compiler/term_constr_util.m:
compiler/tupling.m:
compiler/unify_gen.m:
compiler/unify_gen_deconstruct.m:
compiler/var_locn.m:
    Conform to the changes above.
2022-03-28 10:20:49 +11:00
Zoltan Somogyi
5b97566f8c Make pred declaration and definition order match. 2021-03-25 04:27:30 +11:00
Zoltan Somogyi
25b89ea8c6 Put bigger inputs first.
compiler/hlds_pred.m:
    Put a module_info input before a proc_info input.

compiler/*.m:
    Conform to the above.
2020-11-30 17:34:42 +11:00
Zoltan Somogyi
5f50259d16 Write to explicitly named streams in many modules.
Right now, most parts of the compiler write to the "current output stream".
This was a pragmatic choice at the time, but has not aged well. The problem
is that the answer to the question "where is the current output stream going?"
is not obvious in *all* places in the compiler (although it is obvious in
most). When using such implicit streams, finding where the output is going
to in a given predicate requires inspecting not just the ancestors of that
predicate, but also all their older siblings (since any of them could have
changed the current stream), *including* their entire call trees. This is
usually an infeasible task. By constrast, if we explicitly pass streams
to all output operations, we need only follow the places where the variable
representing that stream is bound, which the mode system makes easy.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

library/term_io.m:
    Fix documentation.
2020-11-14 15:07:55 +11:00
Zoltan Somogyi
0be7bdd5be Simplify implications of debugging.
compiler/handle_options.m:
    Having debugging enabled affects several classes of options the same way.
    Record this effect in one flag per class, not on every option
    separately.

compiler/trace_params.m:
    Replace given_trace_level_is_none, which used to return a bool, with
    is_exec_trace_enabled_at_given_trace_level, which now returns either
    exec_trace_is_not_enabled or exec_trace_is_enabled. This should
    allow peopl to read code calling the function without having to
    process double negatives in their head.

compiler/code_info.m:
compiler/code_loc_dep.m:
compiler/compile_target_code.m:
compiler/llds_out_file.m:
compiler/proc_gen.m:
compiler/trace_gen.m:
    Conform to the change to trace_params.m.

compiler/inlining.m:
    Conform to the change to trace_params.m by deleting any reference
    to trace levels. None of these references in the old code were used.
2020-10-13 01:54:43 +11:00
Zoltan Somogyi
d493841c99 Move imports from interface to implementation. 2020-10-11 11:44:13 +11:00
Zoltan Somogyi
181ada0dbf Avoid -O<n> resetting previously set options.
This implements Mantis feature request #495.

NEWS:
    Announce the change.

compiler/optimization_options.m:
    A new module for managing optimization options.

    It defines a separate bespoke type for every boolean optimization option
    to make it harder to confuse them. It defines a tuple type (opt_tuple)
    for accessing optimization options quickly. It implements the turning on
    (but NOT turning off) of optimizations when a given optimization level
    is selected.

tools/make_optimization_options_middle:
tools/make_optimization_options_db:
    The script that generates the meat of optimization_options.m,
    and the database of option names, kinds and initial values
    that it uses as its input. The script also generates some code
    for the special_handler predicate in compiler/options.m.

tools/make_optimization_options_start:
tools/make_optimization_options_end:
    The handwritten initial and final parts of optimization_options.m.

tools/make_optimization_options:
    The script that pulls these parts together to form optimization_options.m.

compiler/options.m:
    Make every optimization option a special option, to be handled by
    the special_handler predicate. That handling consists of simply
    adding a representation of the option to the end of a cord of
    optimization options, to be processed later by optimization_options.m.
    That processing will record the values of these options in the opt_tuple,
    which is where every other part of the compiler should get them from.

    Change the interface of special_handler to make the above possible.

    Add an "optopt_" (optimization option) prefix to the name of
    every optimization option, to make them inaccessible to the rest
    of the compiler under their old name, and thus help enforce the switch
    to using the opt_tuple. Any access to these options to look up
    their values would fail anyway, since the option data would no longer be
    e.g. bool(yes), but bool_special, but the name change makes this failure
    happen at compile time, not runtime.

    Reclassify a few options to make the above make sense. Some options
    (unneeded_code_debug, unneeded_code_debug_pred_name, and
    common_struct_preds) were classified as oc_opt even though they
    control only the *debugging* of optimizations, while some options
    (c_optimize and inline_alloc) were not classified as oc_opt
    even though we do set them automatically at some optimization levels.

    Delete the opt_level_number option, since it was not used anywhere.

    Delete the code for handling -ON and --opt-space, since that is now
    done in optimization_options.m.

    Add some XXXs.

compiler/handle_options.m:
    Switch to using getopt_io.process_options_userdata_se, as required
    by the new interface of the special_handler in options.m.
    In the absence of errors, invoke optimization_options.m to initialize
    the opt_tuple. Then update the opt_tuple incrementally when processing
    option implications that affect optimization options.

compiler/globals.m:
    Put the opt_tuple into a new field of the globals structure.

compiler/accumulator.m:
compiler/add_pragma_type_spec.m:
compiler/add_trail_ops.m:
compiler/code_info.m:
compiler/code_loc_dep.m:
compiler/compile_target_code.m:
compiler/const_struct.m:
compiler/deforest.m:
compiler/dep_par_conj.m:
compiler/disj_gen.m:
compiler/erl_code_gen.m:
compiler/format_call.m:
compiler/global_data.m:
compiler/grab_modules.m:
compiler/higher_order.m:
compiler/hlds_pred.m:
compiler/inlining.m:
compiler/intermod.m:
compiler/ite_gen.m:
compiler/jumpopt.m:
compiler/libs.m:
compiler/llds_out_code_addr.m:
compiler/llds_out_data.m:
compiler/llds_out_file.m:
compiler/llds_out_instr.m:
compiler/llds_out_util.m:
compiler/matching.m:
compiler/mercury_compile_front_end.m:
compiler/mercury_compile_llds_back_end.m:
compiler/mercury_compile_main.m:
compiler/mercury_compile_middle_passes.m:
compiler/mercury_compile_mlds_back_end.m:
compiler/ml_disj_gen.m:
compiler/ml_gen_info.m:
compiler/ml_lookup_switch.m:
compiler/ml_optimize.m:
compiler/ml_proc_gen.m:
compiler/ml_simplify_switch.m:
compiler/ml_switch_gen.m:
compiler/ml_unify_gen_construct.m:
compiler/optimize.m:
compiler/pd_util.m:
compiler/peephole.m:
compiler/polymorphism.m:
compiler/proc_gen.m:
compiler/simplify_goal_call.m:
compiler/simplify_goal_scope.m:
compiler/simplify_info.m:
compiler/simplify_proc.m:
compiler/simplify_tasks.m:
compiler/stack_layout.m:
compiler/stack_opt.m:
compiler/switch_gen.m:
compiler/switch_util.m:
compiler/tag_switch.m:
compiler/tupling.m:
compiler/unify_gen_construct.m:
compiler/unneeded_code.m:
compiler/unused_args.m:
    Conform to the changes above, mostly by looking up optimization options
    in the opt_tuple. In some places, replace bools containing optimization
    options with the bespoke type of that specific optimization option.

library/getopt_template:
    Fix a bug that screwed up an error message.

    The bug happened when processing a --file option. If one of the
    options in the file was a special option whose special handler failed,
    the code handling that failing option returned both an error indication,
    and the rest of the argument list read in from the file. The code
    handling the --file option then *ignored* the error indication from
    the failed special option, and returned an error message of its own
    complaining about the unconsumed remaining arguments in the file,
    believing them to be non-option arguments, even though these arguments
    were never looked it to see if they were options.

    The fix is for the code handling --flag options to check whether
    the code processing the file contents found any errors, and if so,
    return that error *without* looking at the list of remaining arguments.

    In an unrelated change, factor out a duplicate call.
2020-09-28 18:16:13 +10:00
Zoltan Somogyi
3e030cc064 Flush resume vars to stack before entering a disjunct.
compiler/disj_gen.m:
    When generating code for a non-final disjunct, if the resume point
    across that disjunct may require the resume variables to be
    in their stack slots, flush them to those stack slots *before*
    entering the code of the disjunct, not after. Flushing them
    too late was the cause of Mantis bug #513, which this diff fixes.

    Fix indentation.

compiler/code_gen.m:
compiler/ite_gen.m:
    Flush debug output as soon as it is finished being written,
    that this output appears in the expected order relative to
    mdb events when the compiler is executed in the debugger.

compiler/code_loc_dep.m:
    Add conditionally-compiled debug code to hekp debug the generation
    of code for failures.

    Make some debug output more readable.

    Give a predicate and a bunch of variables a more meaningful names.

compiler/opt_debug.m:
    When dumping instructions for debugging purposes, indent it by four spaces
    instead of tabs. Use more readable code to do the dumping.
2020-07-28 23:51:11 +10:00
Zoltan Somogyi
df229e6237 Don't pass an unused variable.
compiler/var_locn.m:
    Many predicates in var_locn.m took a code_info argument that they
    seemed to use, but it turned out that *all* they used this argument for
    is to pass them to each other. Delete the unneeded code_info arguments.

compiler/call_gen.m:
compiler/closure_gen.m:
compiler/code_loc_dep.m:
compiler/dense_switch.m:
compiler/disj_gen.m:
compiler/ite_gen.m:
compiler/lookup_switch.m:
compiler/lookup_util.m:
compiler/middle_rec.m:
compiler/par_conj_gen.m:
compiler/pragma_c_gen.m:
compiler/proc_gen.m:
compiler/string_switch.m:
compiler/switch_case.m:
compiler/switch_gen.m:
compiler/trace_gen.m:
compiler/unify_gen.m:
compiler/unify_gen_construct.m:
compiler/unify_gen_deconstruct.m:
    Don't pass the unneeded code_info arguments. In predicates that
    as a result of this don't need a code_info argument anymore,
    delete their code_info arguments as well, and recurse.

    Disambiguate empty as cord.empty in the places where the error messages
    about too many arguments also mentioned such ambiguity.

    In code_loc_dep.m, add more detail to debugging output.
2020-07-17 14:25:08 +10:00
Zoltan Somogyi
9d6c8d1780 Improve programming style.
compiler/hlds_llds.m:
    Give some function symbols more meaningful names.

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

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

    Provide a utility predicate for ite_gen.m.

    Generate more readable debug output.

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

    Optimize some tests.

    Break up a predicate to reduce the level of indentation.

    Add some module qualifications to reduce type ambiguity.

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

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

compiler/code_gen.m:
compiler/disj_gen.m:
compiler/frameopt.m:
compiler/hlds_out_goal.m:
compiler/layout_out.m:
compiler/live_vars.m:
compiler/live_vars.m:
compiler/liveness.m:
compiler/liveness.m:
compiler/llds_out_file.m:
compiler/llds_out_instr.m:
compiler/llds_out_util.m:
compiler/lookup_switch.m:
compiler/lookup_switch.m:
compiler/opt_debug.m:
compiler/optimize.m:
compiler/use_local_vars.m:
    Conform to the changes above.
2020-07-17 10:48:13 +10:00
Zoltan Somogyi
17d684a11e Better arg orders in instmap.m.
compiler/instmap.m:
    Replace a non-state-var-friendly and a state-var-friendly pair
    of predicates with just one state-var-friendly predicate.

    Improve the arg order of another predicate as well.

    Improve documentation.

compiler/accumulator.m:
compiler/call_gen.m:
compiler/code_loc_dep.m:
compiler/constraint.m:
compiler/cse_detection.m:
compiler/delay_construct.m:
compiler/dep_par_conj.m:
compiler/erl_code_gen.m:
compiler/erl_code_util.m:
compiler/float_regs.m:
compiler/goal_mode.m:
compiler/goal_util.m:
compiler/hlds_pred.m:
compiler/introduce_parallelism.m:
compiler/lookup_util.m:
compiler/loop_inv.m:
compiler/mode_util.m:
compiler/modecheck_unify.m:
compiler/par_conj_gen.m:
compiler/pd_info.m:
compiler/pd_util.m:
compiler/prog_rep.m:
compiler/stm_expand.m:
compiler/transform.m:
compiler/try_expand.m:
compiler/unneeded_code.m:
    Conform to the change above. Delete unneeded module qualifications.
2019-08-24 17:18:14 +10:00
Zoltan Somogyi
624aaa01f1 Pack subword-sized arguments next to a local sectag.
compiler/du_type_layout.m:
    If a new option is set, then try to represent function symbols with
    only subword-sized arguments by packing those arguments into the same word
    as the primary tag and (if it is needed) a secondary tag.

    If there are too many such function symbols for the available number of
    bits, pick the ones that need the least number of bits, in order to
    allow us to use this representation for as many such function symbols
    as possible.

    This diff implements this packing only for types that have more than one
    argument, because implementing it for types that have only one argument
    has two extra complications. One is the need for another new cons_id
    (see below), which would make this diff bigger and harder to review.
    The other is the need to consider interactions with the direct_arg
    optimization.

    Don't invoke the code for deciding the representation of arguments
    if either (a) the function symbol has no arguments, or (b) its cons_id
    alone dictates how we will treat its argument (in such cases, there is
    always exactly one).

    Fix a bug in computing the number of bits needed to distinguish N things.

    Store the value of the "experiment" option in the params for now,
    since it has helped track down bugs in this change, and may do the same
    for my next change. It costs next to nothing.

compiler/options.m:
    Add an option that controls whether we allow du_type_layout to pack
    arguments next to local secondary tags. The default value is "no",
    since "yes" may break binary compatibility.

    Add an option that controls whether we allow du_type_layout to pack
    arguments next to remote secondary tags. This option is not yet used.

compiler/hlds_data.m:
    Add a new cons_id, shared_local_tag_with_args, to represent function
    symbols in which the arguments are packed next to a local secondary tag.
    Rename the existing shared_local_tag cons_id as shared_local_tag_no_args,
    to clarify the distinction.

    Redesign the representation of secondary tags a bit, to meet the
    requirements I discovered while implementing the new data representation.

compiler/prog_data.m:
    Document the now-expanded uses of the arg_pos_width type.

compiler/ml_unify_gen.m:
compiler/unify_gen.m:
    Implement unifications involving the new cons_id.

compiler/var_locn.m:
    Implement deconstruction unifications involving both right-to-left data
    flow and the new cons_id for the LLDS backend requires var_locn.m
    to implement a new kind of assignment to a variable: one that updates
    its old value. Add a predicate for this. (Previously, deconstructions
    with right-to-left flow could update the old value of a word in a
    memory cell, whose state var_locn.m does *not* track.)

compiler/code_loc_dep.m:
    Provide the interface between unify_gen. and var_locn.m.

compiler/code_info.m:
    Store the number of primary tag bits in the code_info, to save it looking
    up in the globals structure, since with its new code, unify_gen.m needs it
    more often now.

compiler/hlds_out_module.m:
doc/user_guide.texi:
    Implement the capability of restricting the dump of the type table
    to only the types defined in the module being compiled. Without this,
    the type table is cluttered with information about types in other
    modules, including the automatically-included builtin modules.

compiler/handle_options.m:
    Add a new value of the -D option. The new value, du, asks for the
    dumping out of the representations of only the locally defined types.

compiler/ml_gen_info.m:
    Store the number of primary tag bits as a uint8, not as int.

compiler/ml_tag_switch.m:
compiler/switch_util.m:
compiler/tag_switch.m:
    Update the code that generates switches on du types to handle
    local secondary tags that must be masked off before use.

compiler/rtti.m:
    Update the compiler's representation of RTTI information to account for
    the new data representation.

compiler/type_ctor_info.m:
    Construct the updated RTTI representation.

compiler/bytecode_gen.m:
compiler/export.m:
compiler/ml_switch_gen.m:
compiler/ml_type_gen.m:
compiler/modecheck_goal.m:
compiler/rtti_out.m:
compiler/rtti_to_mlds.m:
    Conform for the changes above.

runtime/mercury_type_info.h:
    Extend the representation of du functors in the RTTI to account for
    the new data representation scheme. The extensions add only to the
    *ends* of structures, or to lists of enum values, with the extensions
    only being used if the representation is actually used, which should
    allow the updated runtime to also work with .c files that were compiled
    with a compiler that does *not* have this diff. For the same reason,
    make the old enum value MR_SECTAG_LOCAL a synonym for the new
    MR_SECTAG_LOCAL_REST_OF_WORD, which expresses a distinction that
    did not previously exist.

    Delete a reference to a file that no longer exists.

runtime/mercury_dotnet.cs.in:
library/rtti_implementation.m:
    Update the C# and Mercury mirrors of the types updated in
    mercury_type_info.h.

runtime/mercury_deconstruct.c:
runtime/mercury_deconstruct_macros.h:
runtime/mercury_ml_expand_body.h:
    Implement the deconstruction of terms using the new data representation.

runtime/mercury_deep_copy_body.h:
    Implement the copying of terms using the new data representation.

runtime/mercury_table_type_body.h:
    Implement the tabling of terms using the new data representation.

runtime/mercury_term_size.c:
    Implement computing the size of terms using the new data representation.

runtime/mercury_unify_compare_body.h:
    Implement RTTI-based unifications of terms using the new data
    representation. (Or at least make a first attempt at this implementation.
    We never use RTTI-based unification, so this code has not been tested,
    but it is not clear that it *needs* to be tested.)

library/construct.m:
    Implement the construction of terms using the new data representation.

library/private_builtin.m:
    List MR_SECTAG_LOCAL_REST_OF_WORD as a synonym of MR_SECTAG_LOCAL for Java,
    since rtti_to_mlds.m will now emit the new version.

    Note that the new data representation is not applicable to Java (or C#),
    so it should never see the other kind of sectag (MR_SECTAG_LOCAL_BITS).

tests/hard_coded/sectag_bits.{m,exp}:
tests/hard_coded/sectag_bits_test_data:
    A new test case to test the reading in and writing out (and therefore
    the construction and deconstruction) of terms containing arguments
    packed with a local sectag.

tests/hard_coded/Mmakefile:
    Enable the new test case.
2018-07-08 17:54:11 +02:00
Zoltan Somogyi
901732ce13 Record which variable are dummies at the start.
compiler/var_locn.m:
    We initialize the var_locn_info when the LLDS backend start to
    generate code for a procedure. This change makes the initialization
    record, for every variable in the procedure, whether it is of a dummy type,
    and changes the code executed later to check this record instead of
    repeating the test.

compiler/vartypes.m:
    Change the name of a predicate to make it clearer.

compiler/code_loc_dep.m:
compiler/lambda.m:
compiler/live_vars.m:
compiler/post_typecheck.m:
    Conform to the change in vartypes.m.
2018-04-07 21:11:25 +10:00
Zoltan Somogyi
15aa457e12 Delete $module arg from calls to unexpected. 2018-04-07 18:25:43 +10:00
Zoltan Somogyi
16fb9f9edf Delete the backends' own ptag types.
compiler/llds.m:
compiler/mlds.m:
    Delete the tag type from llds.m, and the mlds_ptag type from mlds.m.
    Replace their uses with the ptag type defined in hlds_data.m.

compiler/code_loc_dep.m:
compiler/llds_out_data.m:
compiler/llds_out_instr.m:
compiler/ml_unify_gen.m:
compiler/mlds_to_c.m:
compiler/peephole.m:
compiler/unify_gen.m:
compiler/var_locn.m:
    Conform to the changes above.
2018-03-07 18:09:50 +11:00
Zoltan Somogyi
955a69efff Give better names to some functions.
compiler/type_util.m:
    Rename the "check_dummy_type" function to "is_type_a_dummy", since this
    expresses its job more clearly.

    Make the implementation of "is_type_a_dummy" slightly more efficient,
    by avoiding some redundant actions.

    Provide a new function "is_either_type_a_dummy" that does
    what its name says, and which is somewhat more efficient than
    two separate calls to "is_type_a_dummy".

compiler/prog_type.m:
    Rename the "check_builtin_dummy_type_ctor" function to
    "is_type_ctor_a_builtin_dummy", since this expresses its job
    more clearly.

compiler/ml_unify_gen.m:
    Conform to the name changes.

    Use the new function where relevant to simplify some code.

    Fix some comments.

compiler/code_info.m:
compiler/code_loc_dep.m:
compiler/continuation_info.m:
compiler/erl_call_gen.m:
compiler/erl_code_gen.m:
compiler/erl_code_util.m:
compiler/erl_unify_gen.m:
compiler/export.m:
compiler/higher_order.m:
compiler/hlds_pred.m:
compiler/live_vars.m:
compiler/llds_out_instr.m:
compiler/mark_tail_calls.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_foreign_proc_gen.m:
compiler/pragma_c_gen.m:
compiler/stack_layout.m:
compiler/term_constr_util.m:
compiler/trace_gen.m:
compiler/unify_gen.m:
compiler/unify_proc.m:
compiler/var_locn.m:
compiler/write_module_interface_files.m:
    Use the new function where relevant.
2018-02-28 13:48:44 +11:00
Zoltan Somogyi
7a2e8257da Encode some invariants in data structures.
compiler/unify_gen.m:
    A unification of the form X = f(Y1, ..., Yn) requires unifying
    X's fields with the variables Yi, while unifications of the form X = Y
    unify two variables. The predicate that generated code for all
    these unifications was set up to unify any two uni_vals, each of which
    could be either a variable or an lval. This setup allowed the expression of

    - field-to-field unifications,
    - variable-to-lval unifications where that lval was not a field, and
    - unifications in which the number of Yi differed from the number of
      the corresponding fields of X,

    none of which should ever happen.

    Replace this setup with another that encodes all three invariants
    in data structures, making the unwanted unification forms impossible
    to express.

    Don't create a list of types of the Yi, whose length we then have to
    match against the length of the list of the Yi itself, and of list
    of their modes. Instead, look up each type only when it is needed.

    Factor out commonalities between X = f(Y1, ..., Yn) unifications
    where f is represented by an single_functor_tag, unshared_tag,
    and shared_remote_tag.

    Merge a couple of xyz_2 predicates into their parent xyz predicate.
    The _2 version was needed only in the distant past, when the only way
    to execute the same code for e.g. single_functor_tag and unshared_tag(0)
    without code duplication was to have the switch arm for one call the _2
    predicate recursively with arguments that lead to the execution of the
    other.

    Use a more consistent naming scheme in the predicates affected by the
    above changes.

compiler/code_loc_dep.m:
compiler/var_locn.m:
    Export a predicate from var_locn.m through code_loc_dep.m to unify_gen.m.
2018-02-22 22:47:36 +11:00
Zoltan Somogyi
4ebc3ffa04 Carve four modules out of prog_data.m.
The prog_data.m module is imported by most modules of the compiler; by
359 modules out of 488, to be exact. Yet it has many parts that most of
those 359 modules don't need. This diff puts those parts into four new
modules. The number of imports of these modules:

    348 modules import prog_data.m
     84 modules import prog_data_foreign.m
     62 modules import prog_data_pragma.m
     12 modules import prog_data_event.m
      5 modules import prog_data_used_modules.m

compiler/prog_data_event.m:
compiler/prog_data_foreign.m:
compiler/prog_data_pragma.m:
compiler/prog_data_used_modules.m:
    New modules. They contain the parts of the parse tree that deal
    respectively with the specification of events and event sets,
    interfacing to foreign languages, pragmas, and the sets of used
    (i.e. not unused) modules.

compiler/prog_data.m:
    Delete the stuff that is now in the new modules. Put the remaining parts
    of the module into a logical order.

compiler/parse_tree.m:
compiler/notes/compiler_design.html:
    Include and document the new modules.

compiler/globals.m:
    Move a type here from prog_data.m, since this is where it belongs.

compiler/add_foreign_proc.m:
compiler/add_mutable_aux_preds.m:
compiler/add_pragma.m:
compiler/add_solver.m:
compiler/add_trail_ops.m:
compiler/call_gen.m:
compiler/code_gen.m:
compiler/code_loc_dep.m:
compiler/comp_unit_interface.m:
compiler/compile_target_code.m:
compiler/complexity.m:
compiler/continuation_info.m:
compiler/coverage_profiling.m:
compiler/ctgc.datastruct.m:
compiler/ctgc.livedata.m:
compiler/ctgc.selector.m:
compiler/deep_profiling.m:
compiler/dep_par_conj.m:
compiler/deps_map.m:
compiler/det_analysis.m:
compiler/det_report.m:
compiler/elds_to_erlang.m:
compiler/equiv_type.m:
compiler/erl_call_gen.m:
compiler/exception_analysis.m:
compiler/export.m:
compiler/fact_table.m:
compiler/foreign.m:
compiler/frameopt.m:
compiler/get_dependencies.m:
compiler/goal_form.m:
compiler/goal_util.m:
compiler/granularity.m:
compiler/hlds_goal.m:
compiler/hlds_module.m:
compiler/hlds_out_goal.m:
compiler/hlds_out_module.m:
compiler/hlds_out_pred.m:
compiler/hlds_pred.m:
compiler/inlining.m:
compiler/intermod.m:
compiler/ite_gen.m:
compiler/item_util.m:
compiler/jumpopt.m:
compiler/layout.m:
compiler/layout_out.m:
compiler/live_vars.m:
compiler/livemap.m:
compiler/llds.m:
compiler/llds_out_file.m:
compiler/llds_out_global.m:
compiler/llds_out_instr.m:
compiler/make.dependencies.m:
compiler/make.module_dep_file.m:
compiler/make_hlds.m:
compiler/make_hlds_warn.m:
compiler/mark_tail_calls.m:
compiler/mercury_compile_llds_back_end.m:
compiler/mercury_compile_main.m:
compiler/ml_call_gen.m:
compiler/ml_code_gen.m:
compiler/ml_code_util.m:
compiler/ml_foreign_proc_gen.m:
compiler/ml_proc_gen.m:
compiler/ml_tailcall.m:
compiler/ml_unify_gen.m:
compiler/mlds.m:
compiler/mlds_to_c.m:
compiler/mlds_to_cs.m:
compiler/mlds_to_java.m:
compiler/modecheck_goal.m:
compiler/module_imports.m:
compiler/module_qual.m:
compiler/module_qual.qualify_items.m:
compiler/modules.m:
compiler/opt_debug.m:
compiler/par_conj_gen.m:
compiler/parse_pragma.m:
compiler/parse_tree_out_info.m:
compiler/parse_tree_out_pragma.m:
compiler/pd_cost.m:
compiler/polymorphism.m:
compiler/pragma_c_gen.m:
compiler/proc_gen.m:
compiler/prog_ctgc.m:
compiler/prog_event.m:
compiler/prog_foreign.m:
compiler/prog_item.m:
compiler/prog_out.m:
compiler/prog_util.m:
compiler/purity.m:
compiler/rbmm.points_to_analysis.m:
compiler/rbmm.points_to_graph.m:
compiler/simplify_goal_call.m:
compiler/simplify_goal_scope.m:
compiler/simplify_proc.m:
compiler/smm_common.m:
compiler/stack_layout.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_sharing.analysis.m:
compiler/structure_sharing.domain.m:
compiler/table_gen.m:
compiler/tabling_analysis.m:
compiler/term_constr_build.m:
compiler/term_constr_initial.m:
compiler/term_constr_main.m:
compiler/term_constr_main_types.m:
compiler/term_constr_pass2.m:
compiler/term_constr_util.m:
compiler/term_errors.m:
compiler/term_pass1.m:
compiler/term_pass2.m:
compiler/term_traversal.m:
compiler/term_util.m:
compiler/termination.m:
compiler/trace_gen.m:
compiler/trailing_analysis.m:
compiler/type_constraints.m:
compiler/typecheck.m:
compiler/unique_modes.m:
compiler/unused_args.m:
compiler/unused_imports.m:
compiler/use_local_vars.m:
compiler/write_deps_file.m:
    Conform to the changes above.
2016-03-13 18:19:31 +11:00
Zoltan Somogyi
5de235065d Fix too-long lines. 2015-11-16 00:09:26 +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
1d109cc26b Remove unused predicates. 2015-09-16 13:40:02 +10:00
Zoltan Somogyi
bbb2535eb5 Break up mercury_to_mercury.m.
With almost 6000 lines, mercury_to_mercury.m was one of the biggest modules
of compiler, but it was far from cohesive. This diff carves seven new modules
out of it, each of which is much more cohesive. The stuff remaining in
mercury_to_mercury.m is still not as cohesive as one would like, but it is
now small enough that moving its individually-cohesive parts into modules
of their own would be overkill.

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

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

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

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

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

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

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

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

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

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

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

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

compiler/parse_tree.m:
    Include the new modules.

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

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

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

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

tools/speedtest:
    Replace mercury_to_mercury.m on the list of the ten largest modules
    of the compiler.
2015-09-06 21:01:11 +10:00
Zoltan Somogyi
1aee1b8ade Don't put variable names in clauses in .opt files.
After this diff, a change in the source file that affects only variable names
won't cause the recompilation of the other modules that use the changed
module's .opt file. (I got a bunch of such unnecessary recompilations when
giving new names to many of varset.m's variables.)

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

compiler/accumulator.m:
compiler/add_class.m:
compiler/add_clause.m:
compiler/add_foreign_proc.m:
compiler/add_heap_ops.m:
compiler/add_pragma_type_spec.m:
compiler/add_pred.m:
compiler/add_trail_ops.m:
compiler/arg_info.m:
compiler/bytecode_gen.m:
compiler/call_gen.m:
compiler/clause_to_proc.m:
compiler/closure_analysis.m:
compiler/code_info.m:
compiler/code_loc_dep.m:
compiler/common.m:
compiler/complexity.m:
compiler/const_prop.m:
compiler/constraint.m:
compiler/continuation_info.m:
compiler/coverage_profiling.m:
compiler/cse_detection.m:
compiler/ctgc.datastruct.m:
compiler/ctgc.util.m:
compiler/deep_profiling.m:
compiler/deforest.m:
compiler/delay_construct.m:
compiler/delay_partial_inst.m:
compiler/dep_par_conj.m:
compiler/det_analysis.m:
compiler/det_report.m:
compiler/det_util.m:
compiler/disj_gen.m:
compiler/equiv_type_hlds.m:
compiler/erl_call_gen.m:
compiler/erl_code_gen.m:
compiler/erl_code_util.m:
compiler/exception_analysis.m:
compiler/float_regs.m:
compiler/follow_code.m:
compiler/follow_vars.m:
compiler/format_call.m:
compiler/goal_expr_to_goal.m:
compiler/goal_path.m:
compiler/goal_store.m:
compiler/goal_util.m:
compiler/headvar_names.m:
compiler/hhf.m:
compiler/higher_order.m:
compiler/hlds_clauses.m:
compiler/hlds_goal.m:
compiler/hlds_llds.m:
compiler/hlds_out_goal.m:
compiler/hlds_out_module.m:
compiler/hlds_out_pred.m:
compiler/hlds_pred.m:
compiler/hlds_rtti.m:
compiler/inlining.m:
compiler/inst_util.m:
compiler/instmap.m:
compiler/intermod.m:
compiler/interval.m:
compiler/lambda.m:
compiler/lco.m:
compiler/live_vars.m:
compiler/liveness.m:
compiler/lookup_switch.m:
compiler/make_goal.m:
compiler/mark_tail_calls.m:
compiler/ml_accurate_gc.m:
compiler/ml_code_gen.m:
compiler/ml_code_util.m:
compiler/ml_disj_gen.m:
compiler/ml_gen_info.m:
compiler/ml_lookup_switch.m:
compiler/ml_proc_gen.m:
compiler/ml_unify_gen.m:
compiler/mode_constraints.m:
compiler/mode_info.m:
compiler/mode_util.m:
compiler/modecheck_call.m:
compiler/modecheck_conj.m:
compiler/modecheck_goal.m:
compiler/modecheck_unify.m:
compiler/modecheck_util.m:
compiler/modes.m:
compiler/par_loop_control.m:
compiler/pd_info.m:
compiler/pd_util.m:
compiler/polymorphism.m:
compiler/post_typecheck.m:
compiler/prog_rep.m:
compiler/prop_mode_constraints.m:
compiler/purity.m:
compiler/qual_info.m:
compiler/quantification.m:
compiler/rbmm.points_to_graph.m:
compiler/rbmm.points_to_info.m:
compiler/rbmm.region_liveness_info.m:
compiler/rbmm.region_transformation.m:
compiler/saved_vars.m:
compiler/set_of_var.m:
compiler/simplify_goal_call.m:
compiler/simplify_goal_conj.m:
compiler/simplify_goal_disj.m:
compiler/simplify_goal_ite.m:
compiler/simplify_goal_scope.m:
compiler/simplify_goal_switch.m:
compiler/simplify_goal_unify.m:
compiler/simplify_info.m:
compiler/simplify_proc.m:
compiler/size_prof.m:
compiler/ssdebug.m:
compiler/stack_alloc.m:
compiler/stack_layout.m:
compiler/stack_opt.m:
compiler/stm_expand.m:
compiler/store_alloc.m:
compiler/structure_reuse.analysis.m:
compiler/structure_reuse.direct.choose_reuse.m:
compiler/structure_reuse.direct.detect_garbage.m:
compiler/structure_reuse.indirect.m:
compiler/structure_reuse.lbu.m:
compiler/structure_reuse.lfu.m:
compiler/structure_sharing.analysis.m:
compiler/structure_sharing.domain.m:
compiler/switch_detection.m:
compiler/table_gen.m:
compiler/tabling_analysis.m:
compiler/term_constr_build.m:
compiler/term_constr_initial.m:
compiler/term_constr_util.m:
compiler/term_pass1.m:
compiler/term_traversal.m:
compiler/term_util.m:
compiler/trace_gen.m:
compiler/trailing_analysis.m:
compiler/try_expand.m:
compiler/tupling.m:
compiler/type_assign.m:
compiler/type_constraints.m:
compiler/typecheck.m:
compiler/typecheck_errors.m:
compiler/unify_gen.m:
compiler/unify_proc.m:
compiler/unique_modes.m:
compiler/unneeded_code.m:
compiler/untupling.m:
compiler/unused_args.m:
compiler/var_locn.m:
    Conform to the above changes, mostly by importing some of the
    three new modules as well as, or instead of, prog_data.m.
2015-08-09 19:02:12 +10:00
Zoltan Somogyi
4d2788ff9e Separate out the location-dependent parts of the code_info.
The code_info type was originally designed to be a single data structure
that holds all of the state of the LLDS code generator. It HAD to be a single
data structure then, because the DCGs we used to pass state around only
supported passing around ONE piece of state. Nevertheless, it contained
three separate kinds of information:

1 static information, which never changed during the lifetime of a code_info
  structure (such as the pred and proc id of the procedure being compiled),

2 persistent information, whose updates were never undone (such as the maximum
  number of temporaries that were ever needed at any one time), and

3 location dependent information, such as "which variables are stored where",
  whose updates *can* be undone when the code generator jumps back to
  a previously visited point in the code, e.g. to start generating code
  for the next disjunct in a disjunction.

Originally, these three kinds of fields were all jumbled up together, but
about ten years ago, I grouped all the fields of the same kind together,
into substructures of code_info named code_info_static, code_info_persistent
and code_info_loc_dep respectively. This improved matters, but some problems
remained, the most important of which is that the code_info always contained
the location dependent information, even when it wasn't meaningful, and there
was no way of indicating this fact. (After initialization, the other two parts
are always meaningful.)

This diff separates out the location dependent part of the code_info
into a new type, code_loc_dep, that can be passed around independently
of the code_info, which now contains only the first two kinds of information
above. In places where the location-dependent information is not meaningful,
you don't need to have a current code_loc_dep.

This separation also makes it easier to see what updates to the code generator
state change only the persistent part (the updated code_info type), only
the location-dependent part (the new code_loc_dep type), or both.

In the process of making this change, I found several places where the
location-dependent part of the code_info (now the code_loc_dep) was being
updated, only for those updates to be thrown away, unread, a short time later.
This happened at the ends of branches in e.g. switches, with the updated
code_loc_deps being thrown away when code generation started working on
the next branch.

compiler/code_loc_dep.m:
    New module containing the location-dependent part of the LLDS code
    generator state. Its contents are derived from those parts of the
    old contents of code_info.m that deal with location-dependent state.

    Many of the predicates moved here work on only on the code_loc_dep
    structure, some others work on both the code_info and code_loc_dep
    structure, and a few work only on the code_info. Predicates in the last
    category are in code_loc_dep.m only if they are either (a) used only
    in this module, or (b) used only with other predicates in this module.

compiler/ll_backend.m:
compiler/notes/compiler_design.html:
    Mention the new module.

compiler/code_info.m:
    Delete the code now in code_loc_dep.m.

    Make the vartypes a field in the static part of the code_info, since it is
    used quite often. (We used to look it up in the proc_info every time.)

    Put the declarations and definitions of the access predicates in an order
    that is consistent with the order of the fields they work on.

    Give some fields and predicates more descriptive names.

compiler/call_gen.m:
compiler/code_gen.m:
compiler/commit_gen.m:
compiler/dense_switch.m:
compiler/disj_gen.m:
compiler/ite_gen.m:
compiler/ll_backend.m:
compiler/lookup_switch.m:
compiler/lookup_util.m:
compiler/middle_rec.m:
compiler/par_conj_gen.m:
compiler/pragma_c_gen.m:
compiler/proc_gen.m:
compiler/string_switch.m:
compiler/switch_case.m:
compiler/switch_gen.m:
compiler/tag_switch.m:
compiler/trace_gen.m:
compiler/unify_gen.m:
compiler/var_locn.m:
    Conform to and take advantage of the changes above.

    Often this required passing an in/out pair of code_loc_deps as well as
    an in/out pair of code_infos, but in many cases, one or more of these
    would not be needed.

    Don't make changes to the code_loc_dep at the end of an arm of a branched
    control structure if those updates are about be thrown away when we
    start generating code for the next arm.

    In several cases, switch to a strategy of taking a snapshot of the
    code_loc_dep before entering a branched control structure as a whole,
    and restoring that state at the start of each arm. We used to take
    a snapshot at the start of each branch, and restore it at its end,
    to be ready for the next branch. The former is easier to make
    correctness arguments about, since the code_loc_dep in an arm
    often has limited scope.

    Make some minor unrelated improvements, such as eliminating the
    unnecessary use of solutions/2, and reordering tests for slightly
    better performance.
2015-07-28 10:19:42 +10:00