Commit Graph

17 Commits

Author SHA1 Message Date
Zoltan Somogyi
8b8b3b7d3f Replace the some() HLDS goal with a more general scope() goal, which can be
Estimated hours taken: 12
Branches: main

Replace the some() HLDS goal with a more general scope() goal, which can be
used not just for existential quantification but also for other purposes.

The main such purposes are new goal types that allow the programmer
to annotate arbitrary goals, and not just whole procedure bodies, with the
equivalents of promise_pure/promise_semipure and promise_only_solution:

	promise_pure ( <impure/semipure goal> )
	promise_semipure ( <impure goal> )

	promise_equivalent_solutions [OutVar1, OutVar2] (
		<cc_multi/cc_nondet goal that computed OutVar1 & OutVar2>
	)

Both are intended to be helpful in writing constraint solvers, as well as in
other situations.

doc/reference_manual.texi:
	Document the new constructs.

library/ops.m:
	Add the keywords of the new constructs to the list of operators.
	Since they work similarly to the "some" operator, they have the same
	precedence.

compiler/hlds_goal.m:
	Replace the some(Vars, SubGoal) HLDS construct, with its optional
	keep_this_commit attribute, with the new scope(Reason, SubGoal)
	construct. The Reason argument may say that this scope is an
	existential quantification, but it can also say that it represents
	a purity promise, the introduction of a single-solution context
	with promise_equivalent_solutions, or a decision by a compiler pass.

	It can also say that the scope represents a set of goals that all arise
	from the unraveling of a unification between a variable and a ground
	term. This was intended to speed up mode checking by significantly
	reducing the number of delays and wakeups, but the cost of the scopes
	themselves turned out to be bigger than the gain in modechecking speed.

	Update the goal_path_step type to refer to scope goals instead of just
	existential quantification.

compiler/prog_data.m:
	Add new function symbols to the type we use to represent goals in items
	to stand for the new Mercury constructs.

compiler/prog_io_goal.m:
	Add code to read in the new language constructs.

compiler/prog_io_util.m:
	Add a utility predicate for use by the new code in prog_io_goal.m.

compiler/make_hlds.m:
	Convert the item representation of the new constructs to the HLDS
	representation.

	Document how the from_ground_term scope reason would work, but do not
	enable the code.

compiler/purity.m:
	When checking the purity of goals, respect the new promise_pure and
	promise_semipure scopes. Generate warnings if such scopes are
	redundant.

compiler/det_analysis.m:
	Make the insides of promise_equivalent_solutions goals single solution
	contexts.

compiler/det_report.m:
	Provide mechanisms for reporting inappropriate usage of
	promise_equivalent_solutions goals.

compiler/instmap.m:
	Add a utility predicate for use by one of the modules above.

compiler/deep_profiling.m:
	Use one of the new scope reasons to prevent simplify from optimizing
	away commits of goals that have been made impure, instead of the old
	keep_this_commit goal feature.

compiler/modes.m:
	Handle from_ground_term scopes when present; for now, they won't be
	present, since make_hlds isn't creating them.

compiler/options.m:
	Add two new compiler options, for use by implementors only, to allow
	finer control over the amount of output one gets with --debug-modes.
	(I used them when debugging the performance of the from_ground_term
	scope reason.) The options are --debug-modes-minimal and
	--debug-modes-verbose.

compiler/handle_options.m:
	Make the options that are meaningful only in the presence of
	--debug-modes imply --debug-modes, since this allows more convenient
	(shorter) invocations.

compiler/mode_debug.m:
	Respect the new options when deciding how much data to print
	when debugging of the mode checking process is enabled.

compiler/switch_detect.m:
	Rename a predicate to make it differ from another predicate by more
	than just its arity.

compiler/passes_aux.m:
	Bring this module up to date with our current style guidelines,
	by using state variable syntax where appropriate.

compiler/*.m:
	Minor changes to conform to the change in the HLDS and/or parse tree
	goal type.

mdbcomp/program_representation.m:
	Rename the some goal to the scope goal, and the same for path steps,
	to keep them in sync with the HLDS.

browser/declarative_tree.m:
	Conform to the change in goal representations.

tests/hard_coded/promise_equivalent_solutions_test.{m,exp}:
	A new test case to test the handling of the
	promise_equivalent_solutions construct.

tests/hard_coded/Mmakefile:
	Enable the new test.

tests/hard_coded/purity/promise_pure_test.{m,exp}:
	A new test case to test the handling of the promise_pure and
	promise_semipure constructs.

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

tests/invalid/promise_equivalent_solutions.{m,err_exp}:
	A new test case to test the error messages for improper use of the
	promise_pure and promise_semipure constructs.

tests/invalid/Mmakefile:
	Enable the new test.
2005-03-24 05:34:41 +00:00
Zoltan Somogyi
c08ca7fbc8 Import only one module per line in the modules of the compiler
Estimated hours taken: 3
Branches: main

compiler/*.m:
	Import only one module per line in the modules of the compiler
	where my previous diff did not already do so.

	Misc other cleanups.

	Where relevant, use the new mechanism in tree.m.

compiler/tree.m:
	Fix a performance problem I noticed while update :- import_module
	items. Instead of supplying a function to convert lists of trees
	to a tree, make the tree data structure able to hold a list of
	subtrees directly. This reduces the number of times where we have to
	convert list of trees to trees that are sticks just to stay within
	the old definition of what a tree is.
2005-03-24 02:00:43 +00:00
Peter Wang
59d2d4a573 This adds a module mdbcomp__trace_counts that reads in the
Estimated hours taken: 17
Branches: main

This adds a module mdbcomp__trace_counts that reads in the
.mercury_trace_counts files produced by the compiler's trace mechanism.
The format of said files was slightly changed.

As the new module is to be used by the compiler and the debugger, it is
placed in the mdbcomp module.  This required bringing some types from the
compiler into a new module within mdbcomp.

browser/trace_counts.m:
	New module for reading execution trace summaries.

browser/prim_data.m:
	New module holding types and predicates moved in from the compiler.
	Types:
		pred_or_func, sym_name, module_name, proc_label,
		special_pred_id, trace_port
	Predicates:
		string_to_sym_name, insert_module_qualifier

	The mode field of proc_label is now an int instead of a proc_id
	to avoid pulling proc_id into mdbcomp.

browser/mdbcomp.m:
	Add trace_counts and prim_data to the mdbcomp module.

browser/declarative_execution.m:
	Renamed mdb's definition of module_name to flat_module_name
	to avoid conflicts with the definition in mdbcomp__prim_data.

runtime/mercury_trace_base.c:
	In the format of .mercury_trace_counts, write module and predicate
	names now use quoted atom syntax so that names with spaces and
	non-printable characters can be machine-parsed.

browser/:
compiler/:
	Many changes to account for movement of types, and the change to
	proc_label.
2005-01-19 03:11:22 +00:00
Zoltan Somogyi
e854a5f9d9 Major improvements to tabling, of two types.
Estimated hours taken: 32
Branches: main

Major improvements to tabling, of two types. The first is the implementation
of the loopcheck and memo forms of tabling for model_non procedures, and the
second is a start on the implementation of a new method of implementing
minimal model tabling, one that has the potential for a proper fix of the
problem that we currently merely detect with the pneg stack (the detection
is followed by a runtime abort). Since this new method relies on giving each
own generator its own stack, the grade component denoting it is "mmos"
(minimal model own stack). The true name of the existing method is changed
from "mm" to "mmsc" (minimal model stack copy). The grade component "mm"
is now a shorthand for "mmsc"; when the new method works, "mm" will be changed
to be a shorthand for "mmos".

configure.in:
scripts/canonical_grade.sh-subr:
scripts/init_grade_options.sh-subr:
scripts/parse_grade_options.sh-subr:
scripts/final_grade_options.sh-subr:
compiler/options.m:
	Handle the new way of handling minimal model grades.

scripts/mgnuc.in:
compiler/compile_target_code.m:
	Conform to the changes in minimal model grade options.

compiler/table_gen.m:
	Implement the transformations required by the loopcheck and memo
	tabling of model_non procedures, and the minimal model own stack
	transformation.

	The new implementation transformations use foreign_procs with extra
	args, since there is no point in implementing them both that way and
	with separate calls to library predicates. This required making the
	choice of which method to use at the top level of each transformation.

	Fix an oversight that hasn't caused problems yet but may in the future:
	mark goals wrapping the original goals as not impure for determinism
	computations.

compiler/handle_options.m:
	Handle the new arrangement of the options for minimal model tabling.
	Detect simultaneous calls for both forms of minimal model tabling,
	and generate an error message. Allow for more than one error message
	generated at once; report them all once rather than separately.

compiler/globals.m:
	Add a mechanism to allow a fix a problem detected by the changes
	to handle_options: the fact that we currently may generate a usage
	message more than once for invocations with more than one error.

compiler/mercury_compile.m:
compiler/make.program_target.m:
compiler/make.util.m:
	Use the new mechanism in handle_options to avoid generating duplicate
	usage messages.

compiler/error_util.m:
	Add a utility predicate for use by handle_options.

compiler/hlds_pred.m:
	Allow memo tabling for model_non predicates, and handle own stack
	tabling.

compiler/hlds_out.m:
	Print information about the modes of the arguments of foreign_procs,
	since this is useful in debugging transformations such as tabling
	that generate them.

compiler/prog_data.m:
compiler/layout_out.m:
compiler/prog_out.m:
runtime/mercury_stack_layout.h:
	Mention the new evaluation method.

compiler/goal_util.m:
	Change the predicates for creating calls and foreign_procs to allow
	more than one goal feature to be attached to the new goal. table_gen.m
	now uses this capability.

compiler/add_heap_ops.m:
compiler/add_trail_ops.m:
compiler/polymorphism.m:
compiler/simplify.m:
compiler/size_prof.m:
compiler/typecheck.m:
compiler/unify_proc.m:
	Conform to the changes in goal_util.

compiler/code_info.m:
compiler/make_hlds.m:
compiler/modules.m:
compiler/prog_io_pragma.m:
	Conform to the new the options controlling minimal model
	tabling.

compiler/prog_util.m:
	Add a utility predicate for use by table_gen.m.

library/std_util.m:
	Conform to the changes in the macros for minimal model tabling grades.

library/table_builtin.m:
	Add the types and predicates required by the new transformations.

	Delete an obsolete comment.

runtime/mercury_grade.h:
	Handle the new minimal model grade component.

runtime/mercury_conf_param.h:
	List macros controlling minimal model grades.

runtime/mercury_tabling.[ch]:
	Define the types needed by the new transformations,

	Implement the performance-critical predicates that need to be
	hand-written for memo tabling of model_non predicates.

	Add utility predicates for debugging.

runtime/mercury_tabling_preds.h:
	Add the implementations of the predicates required by the new
	transformations.

runtime/mercury_mm_own_stacks.[ch]:
	This new module contains the first draft of the implementation
	of the own stack implementation of minimal model tabling.

runtime/mercury_imp.h:
	Include the new file if the grade needs it.

runtime/Mmakefile:
	Mention the new files, and sort the lists of filenames.

runtime/mercury_tabling_macros.h:
	Add a macro for allocating answer blocks without requiring them to be
	pointed to directly by trie nodes.

runtime/mercury_minimal_model.[ch]:
	The structure type holding answer lists is now in mercury_tabling.h,
	since it is now also needed by memo tabling of model_non predicates.
	It no longer has a field for an answer num, because while it is ok
	to require a separate grade for debugging minimal model tabling,
	it is not ok to require a separate grade for debugging memo tabling
	of model_non predicates. Instead of printing the answer numbers,
	print the answers themselves when we need to identify solutions
	for debugging.

	Change function names, macro names, error messages etc where this is
	useful to distinguish the two kinds of minimal model tabling.

	Fix some oversights wrt transient registers.

runtime/mercury_context.[ch]:
runtime/mercury_engine.[ch]:
runtime/mercury_memory.[ch]:
runtime/mercury_wrapper.[ch]:
	With own stack tabling, each subgoal has its own context, so record
	the identity of the subgoal owning a context in the context itself.
	The main computation's context is the exception: it has no owner.

	Record not just the main context, but also the contexts of subgoals
	in the engine.

	Add variables for holding the sizes of the det and nondet stacks
	of the contexts of subgoals (which should in general be smaller
	than the sizes of the corresponding stacks of the main context),
	and initialize them as needed.

	Initialize the variables holding the sizes of the gen, cut and pneg
	stacks, even in grades where the stacks are not used, for safety.

	Fix some out-of-date documentation, and conform to our coding
	guidelines.

runtime/mercury_memory_zones.[ch]:
	Add a function to test whether a pointer is in a zone, to help
	debugging.

runtime/mercury_debug.[ch]:
	Add some functions to help debugging in the presence of multiple
	contexts, and factor out some common code to help with this.

	Delete the obsolete, unused function MR_printdetslot_as_label.

runtime/mercury_context.h:
runtime/mercury_bootstrap.h:
	Move a bootstrapping #define from mercury_context.h to
	mercury_bootstrap.h.

runtime/mercury_context.h:
runtime/mercury_bootstrap.h:
	Move a bootstrapping #define from mercury_context.h to
	mercury_bootstrap.h.

runtime/mercury_types.h:
	Add some more forward declarations of type names.

runtime/mercury_dlist.[ch]:
	Rename a field to avoid assignments that dereference NULL.

runtime/mercury_debug.c:
runtime/mercury_memory.c:
runtime/mercury_ml_expand_body.h:
runtime/mercury_stack_trace.c:
runtime/mercury_stacks.[ch]:
trace/mercury_trace_util.c
	Update uses of the macros that control minimal model tabling.

runtime/mercury_stack_trace.c:
	Provide a mechanism to allow stack traces to be suppressed entirely.
	The intention is that by using this mechanism, by the testing system
	won't have to provide separate .exp files for hlc grades, nondebug
	LLDS grades and debug LLDS grades, as we do currently. The mechanism
	is the environment variable MERCURY_SUPPRESS_STACK_TRACE.

tools/bootcheck:
tools/test_mercury:
	Specify MERCURY_SUPPRESS_STACK_TRACE.

trace/mercury_trace.c:
	When performing retries across tabled calls, handle memo tabled
	model_non predicates, for which the call table tip variable holds
	a record with a back pointer to a trie node, instead of the trie node
	itself.

trace/mercury_trace_internal.c:
	When printing tables, handle memo tabled model_non predicates. Delete
	the code now moved to runtime/mercury_tabling.c.

	Add functions for printing the data structures for own stack minimal
	model tabling.

tests/debugger/print_table.{m,inp,exp}:
	Update this test case to also test the printing of tables for
	memo tabled model_non predicates.

tests/debugger/retry.{m,inp,exp}:
	Update this test case to also test retries across memo tabled
	model_non predicates.

tests/tabling/loopcheck_nondet.{m,exp}:
tests/tabling/loopcheck_nondet_non_loop.{m,exp}:
	New test cases to test loopcheck tabled model_non predicates.
	One test case has a loop to detect, one doesn't.

tests/tabling/memo_non.{m,exp}:
tests/tabling/tc_memo.{m,exp}:
tests/tabling/tc_memo2.{m,exp}:
	New test cases to test memo tabled model_non predicates.
	One test case has a loop to detect, one has a need for minimal model
	tabling to detect, and the third doesn't have either.

tests/tabling/Mmakefile:
	Add the new test cases, and reenable the existing tc_loop test case.

	Rename some make variables and targets to make them better reflect
	their meaning.

tests/tabling/test_mercury:
	Conform to the change in the name of the make target.
2004-07-20 04:41:55 +00:00
Zoltan Somogyi
885fd4a387 Remove almost all dependencies by the modules of parse_tree.m on the modules
Estimated hours taken: 12
Branches: main

Remove almost all dependencies by the modules of parse_tree.m on the modules
of hlds.m. The only such dependencies remaining now are on type_util.m.

compiler/hlds_data.m:
compiler/prog_data.m:
	Move the cons_id type from hlds_data to prog_data, since several parts
	of the parse tree data structure depend on it (particularly insts).
	Remove the need to import HLDS modules in prog_data.m by making the
	cons_ids that refer to procedure ids refer to them via a new type
	that contains shrouded pred_ids and proc_ids. Since pred_ids and
	proc_ids are abstract types in hlds_data, add predicates to hlds_data
	to shroud and unshroud them.

	Also move some other types, e.g. mode_id and class_id, from hlds_data
	to prog_data.

compiler/hlds_data.m:
compiler/prog_util.m:
	Move predicates for manipulating cons_ids from hlds_data to prog_util.

compiler/inst.m:
compiler/prog_data.m:
	Move the contents of inst.m to prog_data.m, since that is where it
	belongs, and since doing so eliminates a circular dependency.
	The separation doesn't serve any purpose any more, since we don't
	need to import hlds_data.m anymore to get access to the cons_id type.

compiler/mode_util.m:
compiler/prog_mode.m:
compiler/parse_tree.m:
	Move the predicates in mode_util that don't depend on the HLDS to a new
	module prog_mode, which is part of parse_tree.m.

compiler/notes/compiler_design.m:
	Mention prog_mode.m, and delete the mention of inst.m.

compiler/mercury_to_mercury.m:
compiler/hlds_out.m:
	Move the predicates that depend on HLDS out of mercury_to_mercury.m
	to hlds_out.m. Export from mercury_to_mercury.m the predicates needed
	by the moved predicates.

compiler/hlds_out.m:
compiler/prog_out.m:
	Move predicates for printing parts of the parse tree out of hlds_out.m
	to prog_out.m, since mercury_to_mercury.m needs to use them.

compiler/purity.m:
compiler/prog_out.m:
	Move predicates for printing purities from purity.m, which is part
	of check_hlds.m, to prog_out.m, since mercury_to_mercury.m needs to use
	them.

compiler/passes_aux.m:
compiler/prog_out.m:
	Move some utility predicates (e.g. for printing progress messages) from
	passes_aux.m to prog_out.m, since some predicates in submodules of
	parse_tree.m need to use them.

compiler/foreign.m:
compiler/prog_data.m:
	Move some types from foreign.m to prog_data.m to allow the elimination
	of some dependencies on foreign.m from submodules of parse_tree.m.

compiler/*.m:
	Conform to the changes above, mostly by updating lists of imported
	modules and module qualifications. In some cases, also do some local
	cleanups such as converting predicate declarations to predmode syntax
	and fixing white space.
2004-06-14 04:17:03 +00:00
Zoltan Somogyi
7bf0cd03af Reduce the overhead of all forms of tabling by eliminating in many cases
Estimated hours taken: 32
Branches: main

Reduce the overhead of all forms of tabling by eliminating in many cases
the overhead of transferring data across the C/Mercury boundary. These
involve lots of control transfers as well as assignments to and from
Mercury abstract machine registers, which are not real machine registers
on x86 machines. Benchmarking in Uppsala revealed this overhead to be
a real problem.

The way we do that is by changing the tabling transformation so that instead
of generating sequences of calls to predicates from library/table_builtin.m,
we generate sequences of calls to C macros from runtime/mercury_tabling_pred.h,
and emit the resulting code string as the body of a foreign_proc goal.
(The old transformation is still available via a new option,
--no-tabling-via-extra-args.)

Since the number of inputs and outputs of the resulting C code sequences
are not always fixed (they can depend on the number of input or output
arguments of predicate being transformed), implementing this required
adding to foreign_procs a new field that allows the specification of extra
arguments to be passed to and from the given foreign code fragment. For now,
this mechanism is implemented only by the C backends, since it is needed
only by the C backends. (We don't support yet tabling on other backends.)

To simplify the new implementation of the field on foreign_procs, consolidate
three existing fields into one. Each of these fields was a list with one
element per argument, so turning them into a single list with a combined record
per argument should also improve reliability, since it reduces the likelyhood
of updates leaving the data structure inconsistent.

The goal paths of components of a tabled predicate depend on whether
-no-tabling-via-extra-args was specified. To enable the expected outputs
of the debugger test cases testing tabling, we add a new mdb command,
goal_paths, that controls whether goal paths are printed by the debugger
at events, and turn off the printing of events in the relevant test cases.

Also, prepare for a future change to optimize the trie structure for
user-defined types by handling type_infos (and once we support them,
typeclass_infos) specially.

compiler/table_gen.m:
	Change the tabling transformation along the lines described above.

	To allow us to factor out as much of the new code as possible,
	we change the meaning of the call_table_tip variable for minimal
	model subgoals: instead of the trie node at the end of the answer
	table, it is not now the subgoal reachable from it. This change
	has no effect as yet, because we use call_table_tip variables
	only to perform resets across retries in the debugger, and we
	don't do retries across calls to minimal model tabled predicates.

	Put predicates into logical groups.

library/table_builtin.m:
runtime/mercury_tabling_preds.h:
	When the new transformations in table_gen.m generate foreign_procs
	with variable numbers of arguments, the interfaces of those
	foreign_procs often do not match the interfaces of the existing
	library predicates at their core: they frequently have one more
	or one fewer argument. To prevent any possible confusion, in such
	cases we add a new variant of the predicate. These predicates
	have the suffix _shortcut in their name. Their implementations
	are dummy macros that do nothing; they serve merely as placeholders
	before or after which the macros that actually do the work are
	inserted.

	Move the definitions of the lookup, save and restore predicates
	into mercury_tabling_preds.h. Make the naming scheme of their
	arguments more regular.

runtime/mercury_minimal_model.c:
runtime/mercury_tabling_preds.h:
	Move the definition of a predicate from mercury_minimal_model.c
	to mercury_tabling_preds.h, since the compiler now needs to be
	able to generate an inlined version of it.

compiler/hlds_goal.m:
	Replace the three existing fields describing the arguments of
	foreign_procs with one, and add a new field describing the extra
	arguments that may be inserted by table_gen.m.

	Add utility predicates for processing the arguments of foreign_procs.

	Change the order of some existing groups of declarations make it
	more logical.

compiler/hlds_pred.m:
runtime/mercury_stack_layout.h:
	Extend the data structures recording the structure of tabling tries
	to allow the representation of trie steps for type_infos and
	typeclass_infos.

runtime/mercury_tabling_macros.c:
	Fix a bug regarding the tabling of typeclass_infos, which is now
	required for a clean compile.

compiler/pragma_c_gen.m:
compiler/ml_code_gen.m:
	Modify the generation of code for foreign_procs to handle extra
	arguments, and to conform to the new data structures for foreign_proc
	arguments.

compiler/llds.m:
	The tabling transformations can now generate significantly sized
	foreign_procs bodies, which the LLDS code generator translates to
	pragma_c instructions. Duplicating these by jump optimization
	may lose more by worsening locality than it gains in avoiding jumps,
	so we add an extra field to pragma_c instructions that tells jumpopt
	not to duplicate code sequences containing such pragma_cs.

compiler/jumpopt.m:
	Respect the new flag on pragma_cs.

compiler/goal_util.m:
	Add a predicate to create foreign_procs with specified contents,
	modelled on the existing predicate to create calls.

	Change the order of the arguments of that existing predicate
	to make it more logical.

compiler/polymorphism.m:
	Conform to the new definition of foreign_procs. Try to simplify
	the mechanism for generating the type_info and typeclass_info
	arguments of foreign_proc goals, but it is not clear that this
	code is even ever executed.

compiler/aditi_builtin_ops.m:
compiler/assertion.m:
compiler/bytecode_gen.m:
compiler/clause_to_proc.m:
compiler/code_gen.m:
compiler/code_info.m:
compiler/code_util.m:
compiler/constraint.m:
compiler/deep_profiling.m:
compiler/deforest.m:
compiler/delay_construct.m:
compiler/dependency_graph.m:
compiler/det_analysis.m:
compiler/det_report.m:
compiler/dnf.m:
compiler/dupelim.m:
compiler/equiv_type_hlds.m:
compiler/exprn_aux.m:
compiler/follow_code.m:
compiler/follow_vars.m:
compiler/frameopt.m:
compiler/goal_form.m:
compiler/goal_path.m:
compiler/higher_order.m:
compiler/higher_order.m:
compiler/hlds_module.m:
compiler/hlds_out.m:
compiler/inlining.m:
compiler/ite_gen.m:
compiler/layout_out.m:
compiler/livemap.m:
compiler/liveness.m:
compiler/llds_out.m:
compiler/loop_inv.m:
compiler/magic.m:
compiler/make_hlds.m:
compiler/mark_static_terms.m:
compiler/middle_rec.m:
compiler/modes.m:
compiler/modules.m:
compiler/opt_debug.m:
compiler/pd_cost.m:
compiler/prog_rep.m:
compiler/purity.m:
compiler/quantification.m:
compiler/reassign.m:
compiler/rl_exprn.m:
compiler/saved_vars.m:
compiler/simplify.m:
compiler/size_prof.m:
compiler/store_alloc.m:
compiler/stratify.m:
compiler/switch_detection.m:
compiler/term_pass1.m:
compiler/term_traversal.m:
compiler/termination.m:
compiler/trace.m:
compiler/typecheck.m:
compiler/unify_proc.m:
compiler/unique_modes.m:
compiler/unneeed_code.m:
compiler/unused_args.m:
compiler/use_local_vars.m:
	Conform to the new definition of foreign_procs, pragma_cs and/or
	table trie steps, or to changed argument orders.

compiler/add_heap_ops.m:
compiler/add_trail_ops.m:
compiler/cse_detection.m:
compiler/dead_proc_elim.m:
compiler/equiv_type.m:
compiler/intermod.m:
compiler/lambda.m:
compiler/lco.m:
compiler/module_util.m:
compiler/opt_util.m:
compiler/stack_opt.m:
compiler/trans_opt.m:
	Conform to the new definition of foreign_procs.

	Bring these modules up to date with our current code style guidelines,
	using predmode declarations, state variable syntax and unification
	expressions as appropriate.

compiler/mercury_compile.m:
	Conform to the changed argument order of a predicate in trans_opt.m.

compiler/options.m:
	Add the --no-tabling-via-extra-args option, but leave the
	documentation commented out since the option is for developers only.

doc/user_guide.texi:
	Document --no-tabling-via-extra-args option, though leave the
	documentation commented out since the option is for developers only.

doc/user_guide.texi:
doc/mdb_categories:
	Document the new goal_paths mdb command.

trace/mercury_trace_internals.c:
	Implement the new goal_paths mdb command.

tests/debugger/completion.exp:
	Conform to the presence of the goal_paths mdb command.

tests/debugger/mdb_command_test.inp:
	Test the existence of documentation for the goal_paths mdb command.

tests/debugger/print_table.{inp,exp*}:
tests/debugger/retry.{inp,exp*}:
	Use the goal_paths command to avoid having the expected output
	depend on the presence or absence of --tabling-via-extra-args.

tests/tabling/table_foreign_output.{m,exp}:
	Add a new test case to test the save/restore of arguments of foreign
	types.

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

tests/tabling/test_tabling:
	Make this script more robust.

	Add an option for testing only the standard model forms of tabling.
2004-06-07 09:07:23 +00:00
Zoltan Somogyi
5d6fd3bd6f Reduce the dependence of earlier parts of the compiler on the later ones.
Estimated hours taken: 4
Branches: main

Reduce the dependence of earlier parts of the compiler on the later ones.
Unnecessary import_module declarations in top level modules such as hlds.m
cause unnecessary recompilations when adding new types in later modules,
such as submodules of ll_backend.m. This change reduces the number of such
unnecessary imports.

There are no changes in algorithms, only functionality being moved around.

compiler/code_model.m:
	Change this module from being a submodule of backend_libs.m to being a
	submodule of hlds.m, since nothing in it is dependent on any backend.

compiler/arg_info.m:
compiler/code_util.m:
	Change arg_info.m from being a submodule of ll_backend.m to being a
	submodule of hlds.m, since most of it is applicable to all current
	and foreseeable backends. Move the one exported predicate that is
	ll_backend dependent, and its support predicates, to code_util.m.

compiler/backend_libs.m:
compiler/ll_backend.m:
compiler/hlds.m:
	Update include_module declarations in accordance with the above.

compiler/prog_data.m:
compiler/term_util.m:
	Instead of defining two separate types for holding argument size and
	termination information, one including HLDS-specific information (in
	term_util.m) and one not (in prog_data.m), use a polymorphic type
	defined in prog_data.m and two monomorphic instances.

compiler/termination.m:
compiler/mercury_to_mercury.m:
	Change the predicates for writing out argument size and termination
	information to handle the polymorphic type (we don't need special
	handling of the monomorphic versions), and move them from termination.m
	to mercury_to_mercury.m, since this allows us to avoid some
	undesirable dependencies.

compiler/base_typeclass_info.m:
compiler/hlds_code_util.m:
	Move the predicate make_instance_string from base_typeclass_info.m
	to hlds_code_util.m, again because it allows us to remove some
	undesirable dependencies.

compiler/top_level.m:
compiler/backend_libs.m:
compiler/check_hlds.m:
compiler/hlds.m:
compiler/ll_backend.m:
compiler/parse_tree.m:
compiler/transform_hlds.m:
	Delete some import_module declarations of other top level modules
	in these top level modules. Some imports were totally unnecessary.
	Some imports were useful in only a small minority of submodules;
	those submodules now import the necessary top level modules directly.

	Move remaining import_module declarations to the implementation section
	where this is feasible.

	Where we still need to import modules we ideally shouldn't, note why.

compiler/*.m:
	Update imports of code_util and arg_info.

	In some cases, import top level modules no longer imported by the
	parent module.

	In some cases, delete unnecessary imports.
2004-03-23 10:52:14 +00:00
Zoltan Somogyi
8693e293a2 This diff makes hlds_pred.m and many callers of its predicates easier to read
Estimated hours taken: 4
Branches: main

This diff makes hlds_pred.m and many callers of its predicates easier to read
and to maintain, but contains no changes in algorithms whatsoever.

compiler/hlds_pred.m:
	Bring this module into line with our current coding standards.
	Use predmode declarations, functions, and state variable syntax
	when appropriate.

	Reorder arguments of predicates where necessary for the use of state
	variable syntax, and where this improves readability.

	Replace old-style lambdas with new-style lambdas or with partially
	applied named procedures.

	Standardize indentation.

compiler/*.m:
	Conform to the changes in hlds_pred.m. This mostly means using the
	new argument orders of predicates exported by hlds_pred.m. Where this
	is now conveniently possible, change predicates to use state
	variable notation.

	In some modules, using state variable notation required changing the
	orders of arguments in the module's top predicate.

compiler/passes_aux.m:
	Change the order of arguments in the calls this module makes to
	allow the callees to use state variable notation.

	Convert this module to state variable notation too.
2003-10-24 06:17:51 +00:00
Zoltan Somogyi
1790c3b505 When generating calls, specify whether the call is to a predicate or
Estimated hours taken: 1
Branches: main

compiler/goal_util.m:
compiler/hlds_module.m:
	When generating calls, specify whether the call is to a predicate or
	function.

compiler/goal_util.m:
compiler/unify_proc.m:
	Move a predicate that generates unsafe casts from unify_proc to
	goal_util, since polymorphism may also want to use it someday.

compiler/add_heap_ops.m:
compiler/add_trail_ops.m:
compiler/aditi_builtin_ops.m:
compiler/deep_profiling.m:
compiler/det_analysis.m:
compiler/higher_order.m:
compiler/polymorphism.m:
compiler/simplify.m:
compiler/table_gen.m:
compiler/type_ctor_info.m:
compiler/type_util.m:
compiler/typecheck.m:
	Trivial diffs to conform to the changes above.
2003-05-29 18:17:16 +00:00
Zoltan Somogyi
d3e315ffd2 Move functionality that is not part of the LLDS backend from
Estimated hours taken: 1
Branches: main

compiler/code_util.m:
compiler/goal_form.m:
compiler/hlds_code_util.m:
	Move functionality that is not part of the LLDS backend from
	ll_backend__code_util to hlds__goal_form and to hlds__hlds_code_util.

	Turn some predicates into functions.

compiler/*.m:
	Conform to the changes above.
2003-03-15 07:11:56 +00:00
Zoltan Somogyi
9551640f55 Import only one compiler module per line. Sort the blocks of imports.
Estimated hours taken: 2
Branches: main

compiler/*.m:
	Import only one compiler module per line. Sort the blocks of imports.
	This makes it easier to merge in changes.

	In a couple of places, remove unnecessary imports.
2003-03-15 03:09:14 +00:00
Ralph Becket
54255f93e7 Make the Prolog term comparison operators (@<, @=<, @>, @>=)
Estimated hours taken: 32
Branches: main

Make the Prolog term comparison operators (@<, @=<, @>, @>=)
builtin since they're often useful and calling compare/3
can look a little awkward.

Simplification now applies the following transformations on the
new builtin operators:

	X  @< Y    --->    some [R] (compare(R, X, Y), R  = (<))
	X @=< Y    --->    some [R] (compare(R, X, Y), R \= (>))
	X @>  Y    --->    some [R] (compare(R, X, Y), R  = (>))
	X @>= Y    --->    some [R] (compare(R, X, Y), R \= (<))

compiler/add_heap_ops.m:
compiler/add_trail_ops.m:
compiler/table_gen.m:
	Added `only_mode' argument to calls to
	goal_util__generate_simple_call which now has an extra parameter.

compiler/goal_util.m:
	Added a new parameter, ModeNo, to goal_util__generate_simple_call.
	ModeNo is either
	- `only_mode' in which case the predicate in question is expected to
	  have exactly one mode or
	- `mode_no(N)' in which case mode number N (counting from 0) is
	  used.
	The inequality transformation uses this to handle calls to compare/3
	with unique arguments (even though the builtin inequality modes don't
	yet handle ui arguments...)

compiler/simplify.m:
	simplify__goal_2 for calls now makes a decision as to whether to
	call simplify__call_goal or simplify__inequality_goal.  The bulk
	of simplify__goal_2 is now in simplify__call_goal.  The
	inequality transformation is handled in simplify__inequality_goal.

compiler/type_util.m:
	Added comparison_result_type constant.

compiler/NEWS:
	Mention these changes.

library/builtin.m:
	Added the inequalities as built-ins.
	Added the function ordering/2.

library/prolog.m:
	Removed the definitions for @< etc.
2002-11-01 07:07:01 +00:00
Zoltan Somogyi
189b9215ae This diff implements stack slot optimization for the LLDS back end based on
Estimated hours taken: 400
Branches: main

This diff implements stack slot optimization for the LLDS back end based on
the idea that after a unification such as A = f(B, C, D), saving the
variable A on the stack indirectly also saves the values of B, C and D.

Figuring out what subset of {B,C,D} to access via A and what subset to access
via their own stack slots is a tricky optimization problem. The algorithm we
use to solve it is described in the paper "Using the heap to eliminate stack
accesses" by Zoltan Somogyi and Peter Stuckey, available in ~zs/rep/stackslot.
That paper also describes (and has examples of) the source-to-source
transformation that implements the optimization.

The optimization needs to know what variables are flushed at call sites
and at program points that establish resume points (e.g. entries to
disjunctions and if-then-elses). We already had code to compute this
information in live_vars.m, but this code was being invoked too late.
This diff modifies live_vars.m to allow it to be invoked both by the stack
slot optimization transformation and by the code generator, and allows its
function to be tailored to the requirements of each invocation.

The information computed by live_vars.m is specific to the LLDS back end,
since the MLDS back ends do not (yet) have the same control over stack
frame layout. We therefore store this information in a new back end specific
field in goal_infos. For uniformity, we make all the other existing back end
specific fields in goal_infos, as well as the similarly back end specific
store map field of goal_exprs, subfields of this new field. This happens
to significantly reduce the sizes of goal_infos.

To allow a more meaningful comparison of the gains produced by the new
optimization, do not save any variables across erroneous calls even if
the new optimization is not enabled.

compiler/stack_opt.m:
	New module containing the code that performs the transformation
	to optimize stack slot usage.

compiler/matching.m:
	New module containing an algorithm for maximal matching in bipartite
	graphs, specialized for the graphs needed by stack_opt.m.

compiler/mercury_compile.m:
	Invoke the new optimization if the options ask for it.

compiler/stack_alloc.m:
	New module containing code that is shared between the old,
	non-optimizing stack slot allocation system and the new, optimizing
	stack slot allocation system, and the code for actually allocating
	stack slots in the absence of optimization.

	Live_vars.m used to have two tasks: find out what variables need to be
	saved on the stack, and allocating those variables to stack slots.
	Live_vars.m now does only the first task; stack_alloc.m now does
	the second, using code that used to be in live_vars.m.

compiler/trace_params:
	Add a new function to test the trace level, which returns yes if we
	want to preserve the values of the input headvars.

compiler/notes/compiler_design.html:
	Document the new modules (as well as trace_params.m, which wasn't
	documented earlier).

compiler/live_vars.m:
	Delete the code that is now in stack_alloc.m and graph_colour.m.

	Separate out the kinds of stack uses due to nondeterminism: the stack
	slots used by nondet calls, and the stack slots used by resumption
	points, in order to allow the reuse of stack slots used by resumption
	points after execution has left their scope. This should allow the
	same stack slots to be used by different variables in the resumption
	point at the start of an else branch and nondet calls in the then
	branch, since the resumption point of the else branch is not in effect
	when the then branch is executed.

	If the new option --opt-no-return-calls is set, then say that we do not
	need to save any values across erroneous calls.

	Use type classes to allow the information generated by this module
	to be recorded in the way required by its invoker.

	Package up the data structures being passed around readonly into a
	single tuple.

compiler/store_alloc.m:
	Allow this module to be invoked by stack_opt.m without invoking the
	follow_vars transformation, since applying follow_vars before the form
	of the HLDS code is otherwise final can be a pessimization.

	Make the module_info a part of the record containing the readonly data
	passed around during the traversal.

compiler/common.m:
	Do not delete or move around unifications created by stack_opt.m.

compiler/call_gen.m:
compiler/code_info.m:
compiler/continuation_info.m:
compiler/var_locn.m:
	Allow the code generator to delete its last record of the location
	of a value when generating code to make an erroneous call, if the new
	--opt-no-return-calls option is set.

compiler/code_gen.m:
	Use a more useful algorithm to create the messages/comments that
	we put into incr_sp instructions, e.g. by distinguishing between
	predicates and functions. This is to allow the new scripts in the
	tool directory to gather statistics about the effect of the
	optimization on stack frame sizes.

library/exception.m:
	Make a hand-written incr_sp follow the new pattern.

compiler/arg_info.m:
	Add predicates to figure out the set of input, output and unused
	arguments of a procedure in several different circumstances.
	Previously, variants of these predicates were repeated in several
	places.

compiler/goal_util.m:
	Export some previously private utility predicates.

compiler/handle_options.m:
	Turn off stack slot optimizations when debugging, unless
	--trace-optimized is set.

	Add a new dump format useful for debugging --optimize-saved-vars.

compiler/hlds_llds.m:
	New module for handling all the stuff specific to the LLDS back end
	in HLDS goal_infos.

compiler/hlds_goal.m:
	Move all the relevant stuff into the new back end specific field
	in goal_infos.

compiler/notes/allocation.html:
	Update the documentation of store maps to reflect their movement
	into a subfield of goal_infos.

compiler/*.m:
	Minor changes to accomodate the placement of all back end specific
	information about goals from goal_exprs and individual fields of
	goal_infos into a new field in goal_infos that gathers together
	all back end specific information.

compiler/use_local_vars.m:
	Look for sequences in which several instructions use a fake register
	or stack slot as a base register pointing to a cell, and make those
	instructions use a local variable instead.

	Without this, a key assumption of the stack slot optimization,
	that accessing a field in a cell costs only one load or store
	instruction, would be much less likely to be true. (With this
	optimization, the assumption will be false only if the C compiler's
	code generator runs out of registers in a basic block, which for
	the code we generate should be unlikely even on x86s.)

compiler/options.m:
	Make the old option --optimize-saved-vars ask for both the old stack
	slot optimization (implemented by saved_vars.m) that only eliminates
	the storing of constants in stack slots, and the new optimization.

	Add two new options --optimize-saved-vars-{const,cell} to turn on
	the two optimizations separately.

	Add a bunch of options to specify the parameters of the new
	optimizations, both in stack_opt.m and use_local_vars.m. These are
	for implementors only; they are deliberately not documented.

	Add a new option, --opt-no-return-cells, that governs whether we avoid
	saving variables on the stack at calls that cannot return, either by
	succeeding or by failing. This is for implementors only, and thus
	deliberately documented only in comments. It is enabled by default.

compiler/optimize.m:
	Transmit the value of a new option to use_local_vars.m.

doc/user_guide.texi:
	Update the documentation of --optimize-saved-vars.

library/tree234.m:
	Undo a previous change of mine that effectively applied this
	optimization by hand. That change complicated the code, and now
	the compiler can do the optimization automatically.

tools/extract_incr_sp:
	A new script for extracting stack frame sizes and messages from
	stack increment operations in the C code for LLDS grades.

tools/frame_sizes:
	A new script that uses extract_incr_sp to extract information about
	stack frame sizes from the C files saved from a stage 2 directory
	by makebatch and summarizes the resulting information.

tools/avg_frame_size:
	A new script that computes average stack frame sizes from the files
	created by frame_sizes.

tools/compare_frame_sizes:
	A new script that compares the stack frame size information
	extracted from two different stage 2 directories by frame_sizes,
	reporting on both average stack frame sizes and on specific procedures
	that have different stack frame sizes in the two versions.
2002-03-28 03:44:41 +00:00
Fergus Henderson
7597790760 Use sub-modules to structure the modules in the Mercury compiler directory.
The main aim of this change is to make the overall, high-level structure
of the compiler clearer, and to encourage better encapsulation of the
major components.

compiler/libs.m:
compiler/backend_libs.m:
compiler/parse_tree.m:
compiler/hlds.m:
compiler/check_hlds.m:
compiler/transform_hlds.m:
compiler/bytecode_backend.m:
compiler/aditi_backend.m:
compiler/ml_backend.m:
compiler/ll_backend.m:
compiler/top_level.m:
	New files.  One module for each of the major components of the
	Mercury compiler.  These modules contain (as separate sub-modules)
	all the other modules in the Mercury compiler, except gcc.m and
	mlds_to_gcc.m.

Mmakefile:
compiler/Mmakefile:
	Handle the fact that the top-level module is now `top_level',
	not `mercury_compile' (since `mercury_compile' is a sub-module
	of `top_level').

compiler/Mmakefile:
	Update settings of *FLAGS-<modulename> to use the appropriate
	nested module names.

compiler/recompilation_check.m:
compiler/recompilation_version.m:
compiler/recompilation_usage.m:
compiler/recompilation.check.m:
compiler/recompilation.version.m:
compiler/recompilation.version.m:
	Convert the `recompilation_*' modules into sub-modules of the
	`recompilation' module.

compiler/*.m:
compiler/*.pp:
	Module-qualify the module names in `:- module', `:- import_module',
	and `:- use_module' declarations.

compiler/base_type_info.m:
compiler/base_type_layout.m:
	Deleted these unused empty modules.

compiler/prog_data.m:
compiler/globals.m:
	Move the `foreign_language' type from prog_data to globals.

compiler/mlds.m:
compiler/ml_util.m:
compiler/mlds_to_il.m:
	Import `globals', for `foreign_language'.

Mmake.common.in:
trace/Mmakefile:
runtime/Mmakefile:
	Rename the %.check.c targets as %.check_hdr.c,
	to avoid conflicts with compiler/recompilation.check.c.
2002-03-20 12:37:56 +00:00
Fergus Henderson
7622e889e0 Define the `heap_pointer' type in private_builtin.m as a new builtin
Estimated hours taken: 2
Branches: main

Define the `heap_pointer' type in private_builtin.m as a new builtin
type with representation MR_TYPECTOR_REP_HP, rather than as equivalent
to `c_pointer'.  This is needed so that the accurate garbage collector
can tell saved heap pointer values apart from other c_pointer values,
which it needs to do in order to handle saved heap pointer values.

library/private_builtin.m:
runtime/mercury.h:
runtime/mercury.c:
	Define the type_ctor_info etc. for the heap_pointer type.

compiler/type_util.m:
	Add a new function `heap_pointer_type'.

compiler/add_heap_ops.m:
	Use `heap_pointer_type' from type_util.m.
2002-02-05 09:14:55 +00:00
Fergus Henderson
6c6082a3ac Avoid saving and restoring the heap pointer across goals which
Estimated hours taken: 2
Branches: main

compiler/add_heap_ops.m:
	Avoid saving and restoring the heap pointer across goals which
	are known not to allocate any heap space.
2001-11-27 15:59:28 +00:00
Fergus Henderson
95acb0d8a2 Implement heap reclamation on failure for the MLDS back-end.
Branches: main
Estimated hours taken: 8

Implement heap reclamation on failure for the MLDS back-end.

library/private_builtin.m:
	Add impure procedures for saving and restoring the heap pointer.

compiler/add_heap_ops.m:
	New file, similar to add_trail_ops.m.
	An HLDS->HLDS transformation to add heap reclamation operations.

compiler/mercury_compile.m:
	Call the new pass.

compiler/notes/compiler_design.html:
	Mention the new pass.

compiler/add_trail_ops.m:
compiler/table_gen.m:
compiler/goal_util.m:
	Abstract out the common code from `generate_call' in table_gen.m,
	add_trail_ops.m, and add_heap_ops.m, and put it in a new procedure
	`generate_simple_goal' in goal_util.m.

compiler/add_heap_ops.m:
compiler/add_trail_ops.m:
	Apply a review suggestion from Peter Ross: when putting code
	in places that should not be reachable, insert code that calls
	private_builtin__unused (which calls error/1) rather
	than just inserting `true'.
2001-11-26 09:31:06 +00:00