Commit Graph

56 Commits

Author SHA1 Message Date
Zoltan Somogyi
d5d5986472 Implement lookup switches in which a switch arm may contain more than one
Estimated hours taken: 40
Branches: main

Implement lookup switches in which a switch arm may contain more than one
solution, such as this code here:

	p(d, "four", f1, 4.4).
	p(e, "five", f2, 5.5).
	p(e, "five2", f3(5), 55.5).
	p(f, "six", f4("hex"), 6.6).
	p(g, "seven", f5(77.7), 7.7).
	p(g, "seven2", f1, 777.7).
	p(g, "seven3", f2, 7777.7).

Such code occurs frequently in benchmark programs used to evaluate the
performance of tabled logic programming systems.

Change frameopt.m, which previously worked only on det and semidet code,
to also work for nondet code. For predicates such as the one above, frameopt
can now arrange for the predicate's nondet stack frame to be created only
when a switch arm that has more than one solution is selected.

compiler/lookup_switch.m:
	Extend the existing code for recognizing and implementing lookup
	switches to recognize and implement them even if they are model_non.

compiler/lookup_util.m:
	New module containing utility predicates useful for implementing
	both lookup switches, and in the future, lookup disjunctions (i.e.
	disjunctions that correspond to a nondet arm of a lookup switch).

compiler/ll_backend.m:
	Include the new module.

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

compiler/global_data.m:
	Move the job of filling in dummy slots to our caller, in this case
	lookup_switch.m.

compiler/frameopt.m:
	Generalize the existing code for delaying stack frame creation,
	which worked only on predicates that live on the det stack, to work
	also on predicates that live on the nondet stack. Without this,
	predicates whose bodies are model_non lookup switches would create
	a nonstack stack frame before the switch is ever entered, which
	is wasteful if the selected switch arm has at most one solution.

	Since the structure of model_non predicates is more complex (you can
	cause a branch to a label by storing its address in a redoip slot,
	you can succeed from the frame without removing the frame), this
	required considerable extra work. To make the new code debuggable,
	record, for each basic block that needs a stack frame, *why* it
	needs that stack frame.

compiler/opt_util.m:
	Be more conservative about what refers to the stack. Export some
	previously internal functionality for frameopt. Turn some predicates
	into functions, and rename them to better reflect their purpose.

compiler/opt_debug.m:
	Print much more information about pragma_c and call LLDS instructions.

compiler/prog_data.m:
	Add an extra attribute to foreign_procs that says that the code
	of the foreign_proc assumes the existence of a stack frame.
	This is needed to avoid frameopt optimizing the stack frame away.

compiler/add_pragma.m:
	When processing fact tables, we create foreign_procs that assume
	the existence of the stack frame, so set the new attribute.

compiler/pragma_c_gen.m:
	When processing foreign_procs, transmit the information in the
	attribute to the generated LLDS code.

compiler/llds.m:
	Rename the function symbols referring to the fixed slots in nondet
	stack frames to make them clearer and to avoid overloading function
	symbols such as curfr and succip.

	Rename the function symbols of the call_model type to avoid overloading
	the function symbols of the code_model type.

	Add a new field to the c_procedure type giving the code_model of the
	procedure, and give names to all the fields.

	Describe the stack slots used by lookup switches to the debugger
	and native gc.

compiler/options.m:
doc/user_guide.texi:
	Add a new option, --debug-opt-pred-name, that does when the existing
	--debug-opt-pred-id options does, but taking a user-friendly predicate
	name rather than a pred_id as its argument.

compiler/handle_options.m:
	Process --debug-opt-pred-name, and make --frameopt-comments imply
	--auto-comments, since it is not useful without it.

	Reformat some existing comments that were written in the days of
	8-space indentation.

compiler/optimize.m:
	Implement the new option.

	Use the new field of the c_procedure type to try only the version
	of frameopt appropriate for the code model of the current procedure.

	Do a peephole pass after frameopt, since frameopt can generate code
	sequences that peephole can optimize.

	Make the mechanism for recording the process of optimizing procedure
	bodies more easily usable by including the name of the optimization
	that created a given version of the code in the name of the file
	that contains that version of the code, and ensuring that all numbers
	are two characters long, so that "vi procname*.opt*" looks at the
	relevant files in the proper chronological sequence, instead of having
	version 11 appear before version 2.

compiler/peephole.m:
	Add a new optimization pattern: a "mkframe, goto fail" pair (which
	can be generated by frameopt) should be replaced by a simple "goto
	redo".

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

compiler/llds_out.m:
	Ensure that C comments nested inside comment(_) LLDS instructions
	aren't emitted as nested C comments, since C compilers cannot handle
	these.

compiler/code_info.m:
compiler/code_util.m:
compiler/continuation_info.m:
compiler/dupelim.m:
compiler/exprn_aux.m:
compiler/jumpopt.m:
compiler/livemap.m:
compiler/llds_out.m:
compiler/mercury_compile.m:
compiler/middle_rec.m:
compiler/ml_code_gen.m:
compiler/opt_debug.m:
compiler/opt_util.m:
compiler/peephole.m:
compiler/stack_layout.m:
compiler/transform_llds.m:
compiler/var_locn.m:
	Conform to the change to prog_data.m, opt_util.m and/or llds.m.

compiler/handle_options.m:
	Don't execute the code in stdlabel.m if doing so would cause a compiler
	abort.

tests/hard_coded/dense_lookup_switch_non.{m,exp}:
	New test case to exercise the new algorithm.

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

tests/hard_coded/cycles.m:
	Make this test case conform to our coding convention.
2006-04-26 03:06:29 +00:00
Zoltan Somogyi
e8832be3a5 A new module that contains code to standardize labels in the LLDS.
Estimated hours taken: 1
Branches: main

compiler/stdlabel.m:
	A new module that contains code to standardize labels in the LLDS.

compiler/ll_backend.m:
	Include the new module in this package.

compiler/options.m:
	Add an option that governs whether stdlabel.m is invoked or not.

compiler/optimize.m:
	If the option is set, invoke stdlabel.m.

compiler/opt_util.m:
	Add an option to opt_util.replace_labels_instruction_list to allow
	it to replace labels in label instructions themselves.

compiler/dupelim.m:
	Conform to the changes in opt_util.m

compiler/notes/compiler_design.html:
	Document the new module.
2006-04-10 04:28:24 +00:00
Julien Fischer
459847a064 Move the univ, maybe, pair and unit types from std_util into their own
Estimated hours taken: 18
Branches: main

Move the univ, maybe, pair and unit types from std_util into their own
modules.  std_util still contains the general purpose higher-order programming
constructs.

library/std_util.m:
	Move univ, maybe, pair and unit (plus any other related types
	and procedures) into their own modules.

library/maybe.m:
	New module.  This contains the maybe and maybe_error types and
	the associated procedures.

library/pair.m:
	New module.  This contains the pair type and associated procedures.

library/unit.m:
	New module. This contains the types unit/0 and unit/1.

library/univ.m:
	New module. This contains the univ type and associated procedures.

library/library.m:
	Add the new modules.

library/private_builtin.m:
	Update the declaration of the type_ctor_info struct for univ.

runtime/mercury.h:
	Update the declaration for the type_ctor_info struct for univ.

runtime/mercury_mcpp.h:
runtime/mercury_hlc_types.h:
	Update the definition of MR_Univ.

runtime/mercury_init.h:
	Fix a comment: ML_type_name is now exported from type_desc.m.

compiler/mlds_to_il.m:
	Update the the name of the module that defines univs (which are
	handled specially by the il code generator.)

library/*.m:
compiler/*.m:
browser/*.m:
mdbcomp/*.m:
profiler/*.m:
deep_profiler/*.m:
	Conform to the above changes.  Import the new modules where they
	are needed; don't import std_util where it isn't needed.

	Fix formatting in lots of modules.  Delete duplicate module
	imports.

tests/*:
	Update the test suite to confrom to the above changes.
2006-03-29 08:09:58 +00:00
Zoltan Somogyi
9736a7c600 Fix a bug reported by Samrith, which is that some of the files in
Estimated hours taken: 1
Branches: main

Fix a bug reported by Samrith, which is that some of the files in
benchmarks/progs/icfp2000, e.g. eval.m, got a compiler abort when compiled
with -O0 --optimize-repeat=0 --optimize-saved-vars. This was because
--optimize-saved-vars relied on jump optimization being done, but
--optimize-repeat=0 disables jump optimization.

compiler/handle_options.m:
	Make --optimize-repeat at least one if some other optimization
	requires the optimizations controlled by --optimize-repeat.

compiler/optimize.m:
compiler/use_local_vars.m:
	Rename some predicates to make their unqualified names more meaningful.

	Delete unnecessary module qualifications. Switch to using . instead of
	__ as module qualifier.

compiler/mercury_compile.m:
	Conform to the change to optimize.m.

compiler/modules.m:
	Rename a predicate to avoid a confusing overloading.

compiler/compile_target_code.m:
	Conform to the change to modules.m.

tests/valid/eval.m:
	New test case to check the fix.

tests/valid/Mmakefile:
	Enable the new test case.
2006-01-31 05:20:45 +00:00
Julien Fischer
5f589e98fb Various cleanups for the modules in the compiler directory.
Estimated hours taken: 4
Branches: main

Various cleanups for the modules in the compiler directory.  The are
no changes to algorithms except the replacement of some if-then-elses
that would naturally be switches with switches and the replacement of
most of the calls to error/1.

compiler/*.m:
	Convert calls to error/1 to calls to unexpected/2 or sorry/2 as
	appropriate throughout most or the compiler.

	Fix inaccurate assertion failure messages, e.g. identifying the
	assertion failure as taking place in the wrong module.

	Add :- end_module declarations.

	Fix formatting problems and bring the positioning of comments
	into line with our current coding standards.

	Fix some overlong lines.

	Convert some more modules to 4-space indentation.  Fix some spots
	where previous conversions to 4-space indentation have stuffed
	the formatting of the code up.

	Fix a bunch of typos in comments.

	Use state variables in more places; use library predicates
	from the sv* modules where appropriate.

	Delete unnecessary and duplicate module imports.

	Misc. other small cleanups.
2005-11-17 15:57:34 +00:00
Zoltan Somogyi
f9fe8dcf61 Improve the error messages generated for determinism errors involving committed
Estimated hours taken: 8
Branches: main

Improve the error messages generated for determinism errors involving committed
choice contexts. Previously, we printed a message to the effect that e.g.
a cc pred is called in context that requires all solutions, but we didn't say
*why* the context requires all solutions. We now keep track of all the goals
to the right that could fail, since it is these goals that may reject the first
solution of a committed choice goal.

The motivation for this diff was the fact that I found that locating the
failing goal can be very difficult if the conjunction to the right is
a couple of hundred lines long. This would have been a nontrivial problem,
since (a) unifications involving values of user-defined types are committed
choice goals, and (b) we can expect uses of user-defined types to increase.

compiler/det_analysis.m:
	Keep track of goals to the right of the current goal that could fail,
	and include them in the error representation if required.

compiler/det_report.m:
	Include the list of failing goals to the right in the representations
	of determinism errors involving committed committed choice goals.

	Convert the last part of this module that wasn't using error_util
	to use error_util. Make most parts of this module just construct
	error message specifications; print those specifications (using
	error_util) in only a few places.

compiler/hlds_out.m:
	Add a function for use by the new code in det_report.m.

compiler/error_util.m:
	Add a function for use by the new code in det_report.m.

compiler/error_util.m:
compiler/compiler_util.m:
	Error_util is still changing reasonably often, and yet it is
	included in lots of modules, most of which need only a few simple
	non-parse-tree-related predicates from it (e.g. unexpected).
	Move those predicates to a new module, compiler_util.m. This also
	eliminates some undesirable dependencies from libs to parse_tree.

compiler/libs.m:
	Include compiler_util.m.

compiler/notes/compiler_design.html:
	Document compiler_util.m, and fix the documentation of some other
	modules.

compiler/*.m:
	Import compiler_util instead of or in addition to error_util.
	To make this easier, consistently use . instead of __ for module
	qualifying module names.

tests/invalid/det_errors_cc.{m,err_exp}:
	Add this new test case to test the error messages for cc contexts.

tests/invalid/det_errors_deet.{m,err_exp}:
	Add this new test case to test the error messages for unifications
	inside function symbols.

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

tests/invalid/det_errors.err_exp:
tests/invalid/magicbox.err_exp:
	Change the expected output to conform to the change in det_report.m,
	which is now more consistent.
2005-10-28 02:11:03 +00:00
Zoltan Somogyi
c745c93c1d Fix an old bug: when invoking the compiler with -vS, many of the statistics
Estimated hours taken: 1
Branches: main

Fix an old bug: when invoking the compiler with -vS, many of the statistics
printed didn't say what they are for, because the relevant messages were
enabled only with -V.

compiler/options.m:
	Add a new option, detailed_statistics. This option is not visible
	to users.

compiler/handle_options.m:
	Set detailed_statistics only if -v and -S are both set.

compiler/mercury_compile.m:
compiler/modes.m:
compiler/modules.m:
compiler/optimize.m:
compiler/typecheck_errors.m:
	In a bunch of places where progress messages are enabled only with -V
	and not with -v, consult detailed_statistics instead of statistics
	to decide whether to print statistics, in order to make sure you
	get only interpretable statistics.

compiler/make_hlds_passes.m:
	Print messages before two statistics reports, because otherwise the
	statistics are not interpretable. Don't print stats for module
	optimization, since it is now a no-op.

compiler/cse_detection.m:
	Print statistics if detailed_statistics is set. This is useful because
	in some cases, cse_detection can be expensive (it reruns mode
	analysis).

compiler/simplify.m:
	Print statistics if detailed_statistics is set. This is useful because
	in some cases, simplify can be expensive.
2005-10-25 06:33:03 +00:00
Zoltan Somogyi
753d9755ae When returning from det and semidet predicates, load the return address into a
Estimated hours taken: 3
Branches: main

When returning from det and semidet predicates, load the return address into a
local C variable instead of the succip abstract machine "register" before
popping the stack frame and returning. This gives the C compiler more freedom
to reorder instructions.

This diff gets a 1.4% speed increase on the compiler.

runtime/mercury_stacks.h:
	Provide a new macro, MR_decr_sp_and_return, to do the combined job that
	its name describes.

compiler/llds.m:
	Add a new LLDS instruction that corresponds to the new macro.

compiler/llds_out.m:
	Output the new LLDS instruction.

compiler/peephole.m:
	Add a predicate that looks for and exploits opportunities for using
	the new instruction.

compiler/optimize.m:
	Invoke the new peephole predicate as the next-to-last optimization
	pass. (The last is wrapping up blocks created by --use-local-vars.)

compiler/*.m:
	Minor changes to handle the new instruction.
2005-09-14 01:29:21 +00:00
Zoltan Somogyi
f0dbbcaa34 Generate better code for base relations such as the ones in the transitive
Estimated hours taken: 16
Branches: main

Generate better code for base relations such as the ones in the transitive
closure benchmarkings in the paper on minimal model tabling. These improvements
yield speedups ranging from 5 to 25% on those benchmarks.

compiler/use_local_vars.m:
	Make this optimization operate on extended basic blocks instead of
	plain basic blocks. The greater length of extended basic blocks
	allows the local variables to have maximum scope possible. The price
	is that the test for whether assignment to a given lvalue can be
	avoided or not is now dependent on which of the constituent basic
	blocks of extended basic block contains the assignment, and thus the
	test has to be evaluate once for each assignment we try to optimize
	instead of once per block.

	Don't allocate temporary variables if the optimization they are
	intended for turns out not to be allowed. This change avoids having
	declarations for unused temporary variables in the resulting C code.

	If --auto-comments is set, insert use_local_vars.m's main data
	structure, the livemap, into the generated LLDS code as a comment.

compiler/peephole.m:
	Look for the pattern

		mkframe(Size, Redoip)
		<straight line instructions that don't use stack slots>
		succeed

	and optimize away the mkframe. This pattern always arises for
	procedures that are actually semidet but are declared nondet (such
	as the base relations in the tabling benchmarks), and may also arise
	for semidet branches of nondet procedures.

compiler/llds.m:
	Allow an existing peephole pattern to work better. The pattern is

		mkframe(Seize, do_fail)
		<straight line instructions>
		redoip(curfr) = Redoip

	Previously, if some compiler-generated C code was among the straight
	line instructions, the pattern couldn't be applied, since peephole.m
	couldn't know whether it branched away through the redoip slot of the
	frame. This diff adds an extra slot to the relevant pragma_c component
	that tells peephole.m (actually, the predicate in opt_util.m that
	peephole relies on) whether this is the case.

compiler/basic_block.m:
	Provide functionality for merging basic blocks into extended basic
	blocks.

compiler/dupelim.m:
	Conform to the change in basic_block.m's interface.

	Convert to four-space indentation, and fix departures from our style
	guidelines.

compiler/opt_util.m:
	Provide extra information now needed by use_local_vars.

	Convert to four-space indentation, and fix departures from our style
	guidelines.

compiler/opt_debug.m:
	Show the user friendly versions of label names when dumping livemaps
	and instructions.

	Shorten the dumped descriptions of registers and stack slots.

	Dump instructions inside blocks.

compiler/frameopt.m:
	Conform to the changes in opt_util and opt_debug's interfaces.

compiler/optimize.m:
	Use the facilities of opt_debug instead of llds_out when dumping the
	LLDS after each optimization, since these are now more compact and
	thus reader friendly.

	Print unmangled names when writing progress messages.

	Put the dump files we generate with --opt-debug in a separate
	subdirectory, since when compiling e.g. tree234.m, the process
	can generate more than a thousand files. Give the dump files
	minimally mangled names.

compiler/code_gen.m:
compiler/pragma_c_gen.m:
	Convert to four-space indentation, and fix departures from our style
	guidelines.

	Conform to the change in llds.m.

compiler/code_info.m:
compiler/exprn_aux.m:
compiler/ite_gen.m:
compiler/jumpopt.m:
compiler/livemap.m:
compiler/llds_out.m:
compiler/middle_rec.m:
compiler/trace.m:
	Conform to the change in llds.m.
2005-09-07 06:51:57 +00:00
Zoltan Somogyi
828d969e67 Significantly improve the capabilities of the LLDS optimization that tries
Estimated hours taken: 20
Branches: main

Significantly improve the capabilities of the LLDS optimization that tries
to delay the creation of the stack frame, in the hope that on some computation
paths the frame won't need to be created at all. Previously, the delayed
setup of the stack frame could take place only when a block without a stack
frame fell through to a block that needed a stack frame. If block B1 jumped
to another block B2 that needed a frame, this was taken as meaning that B1
also had to have a frame. This was a problem, because if B1 ends with a
computed goto, some of whose targets need stack frames and some do not,
this limitation effectively gave all of them a stack frame, whether they
wanted it or not, and thus required them to execute the stack frame teardown
code.

This diff removes the limitation, optimization allows B1 in this case to not
have a stack frame. Instead of jumping to B2, B1 will not jump to a label B3
it inserts immediately before B2, the code at B3 setting up the stack frame
and falling through to B2. (We also insert code to jump around B3 if the
code immediately preceding it could fall into it accidentally.)

The new code in frameopt is conceptually cleaner than it was before, because
we now handle transitions from blocks that don't have a stack stack to blocks
that do in a much more uniform manner.

Most of the changes to other modules are to make the change to frameopt.m
easier to debug.

The motivation for the change was that we were beaten by YAP (Yet Another
Prolog) on the deriv benchmark due to the limitation of frameopt. I haven't
measured against YAP yet, but the runtime for 1.5 million iterations has been
reduced from about 20 seconds to about 13.

Since the compiler doesn't have any predicates that are both frequently used
and can benefit from the removal of that old limitation (which is why the
limitation wasn't really noticed before), there is no measurable effect
on the speed of the compiler itself.

compiler/frameopt.m:
	Effectively rewrite the optimization that delays stack frame creation
	along the lines above. The code for the optimization that keeps the
	stack frame for recursive calls if possible is unaffected.

	If the new option --frameopt-comments is specified, insert into the
	generated LLDS code a nicely formatted description of the main
	frameopt.m data structures. These are much easier to read that the
	term browser in the debugger.

compiler/options.m:
	Add the new developer-only option --frameopt-comments.

compiler/llds_out.m:
	Change the way we output comments to make the coments generated by
	frameopt.m easier to read. (We output comments only if --auto-comments
	is given, which it usually isn't.)

compiler/opt_debug.m:
	Provide the functionality of printing local labels in an easier-to-read
	form that doesn't repeat the (possibly long) procedure name. Local
	labels can now be printed as e.g. local_15.

	Rewrite the module to use functions instead of predicates for appending
	strings, since this makes the code shorter, easier to use and to read.
	The original code was written before Mercury had functions.

compiler/switch_util.m:
	When gathering information about switches, return the cons_id with each
	goal.

	Switch to four-space indentation.

compiler/tag_switch.m:
	When generating code for switches, insert a comment at the start of
	each case saying what cons_id it is for, using the new information from
	switch_util. This is to make the generated code easier to understand.

	Switch to four-space indentation.

compiler/ml_tag_switch.m:
	Conform to the change in switch_util.

compiler/optimize.m:
	Conform to the slightly modified interface of frameopt.m.

	Switch to four-space indentation.

compiler/peephole.m:
	Switch to four-space indentation, and fix some coding style issues.

compiler/basic_block.m:
	When dividing a procedure body into basic blocks, remember for each
	block whether it could be fallen into. This modification is not
	strictly required for this change, since frameopt has its own
	(specialized) code for creating basic blocks, but it could be useful
	in the future.

compiler/dupelim.m:
compiler/use_local_vars.m:
	Conform to the change in basic_block.m.
2005-08-25 03:19:48 +00:00
Zoltan Somogyi
3c60c0e485 Change a bunch of modules to import only one module per line, even
Estimated hours taken: 4
Branches: main

compiler/*.m:
	Change a bunch of modules to import only one module per line, even
	from the library.

compiler/mlds_to_il.m:
compiler/mlds_to_managed.m:
	Convert these modules to our current coding style. Use state variables
	where appropriate. Use predmode declarations where possible.
2005-03-22 06:40:32 +00:00
Julien Fischer
601fe20aba Simplify the structure of the compiler by removing the cycle
Estimated hours taken: 3.5
Branches: main

Simplify the structure of the compiler by removing the cycle
parse_tree -> backend_libs -> check_hlds -> parse_tree
from the package dependency graph.

I've done this by factoring out the code in backend_libs.foreign
and backend_libs.name_mangle that is needed by the frontend of
the compiler and putting it in a new module, parse_tree.prog_foreign.
This removes the dependency between the parse_tree and backend_libs
packages.

The obvious downside to this is that the name mangler is now
split in two, although such a division was always in implicit
in the predicates of the name_mangle module anyway, ie. between
those bits that operate on the HLDS/MLDS/LLDS level data structures
and those that don't.

compiler/name_mangle.m:
compiler/foreign.m:
compiler/prog_foreign.m:
	Move code for dealing with foreign language procedures that
	is required by the parse_tree package into a new module,
	prog_foreign.

	Update the formatting in some of these modules so that
	they match our current coding standard.

compiler/*.m:
	Update to reflect the above change.

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

	Fix some spelling errors.
2005-03-21 04:45:51 +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
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
cc508c83de Perform frame optimization on nondet predicates.
Estimated hours taken: 6
Branches: main

Perform frame optimization on nondet predicates. The need for this was revealed
by benchmarking in Uppsala, which initially showed Mercury to take three to
five times as long as XSB on some tabling benchmarks. One major contributor
was the fact that the predicate returning answers out of answer table
was creating and destroying a nondet stack frame for every answer it returned.

To make this change easier, make the representation of labels more reader
friendly, classifying them primarily on whether they represent entry or
internal labels, and only secondarily on the scope in which they represent
valid references to the label.

compiler/frameopt.m:
	Add a predicate to perform frame optimization on model_non predicates.
	This optimization involves separating the steps of creating the frame
	(done once) and setting the redoip (potentially done on every
	iteration).

compiler/optimize.m:
	Invoke this new predicate. Reorder the arguments of predicates in this
	file, and the top level predicates of the optimizations it invokes,
	to allow the use of state variable notation.

runtime/mercury_stacks.h:
	Provide macros for creating nondet stack frames that do not fill in the
	redoip slot.

compiler/llds.m:
	Make the setting of redoip optional in mkframe operations.

	Make the representation of labels more reader friendly.

compiler/layout_out.m:
	Change the representation of label layouts to enforce the invariant
	that these can refer only to internal labels. (The layout structures
	of entry labels are proc layout structures, whose design enforces the
	relevant invariant already.)

compiler/jumpopt.m:
	Add an optimization that improves code that matches a new pattern:

	% Attempt to transform code such as
	%
	%       if (Cond) L1
	%       goto L2
	%
	% into
	%
	%       if (! Cond) L2
	%       <code at L1>
	%
	% when we know the code at L1 and don't know the code at L2.

	The new frame optimization creates instances of this pattern, usually
	with L2 being do_fail.

compiler/*.m:
	Minor diffs to conform to the changes above.
2004-05-23 23:14:37 +00:00
Zoltan Somogyi
e64c6cab22 Bring this module up to date with our current coding standards.
Estimated hours taken: 2
Branches: main

compiler/mercury_compile.m:
	Bring this module up to date with our current coding standards. Use
	predmode declarations and state variable syntax where appropriate.
	Reorder predicate arguments where this is needed for the use of state
	variable syntax. Replace lambda expressions with explicitly named
	predicates where appropriate. Break up predicates that are excessively
	long and/or excessively deeply indented. Fix inconsistent indentation
	and wrap 80+ column lines.

	The only algorithmic change is the replacement of some calls to
	io__write with calls to predicates in error_util.

compiler/error_util.m:
	Add a predicate for printing messages without context, for use by
	mercury_compile.m to report problems that are not specific to
	a single predicate, e.g. inconsistent options.

	Bring this module up to date with our coding standards. Use predmode
	declarations and state variable syntax where appropriate.

compiler/check_typeclass.m:
compiler/dnf.m:
compiler/optimize.m:
	Reorder arguments of predicates exported to mercury_compile.m to
	allow the use of state variable syntax.

compiler/globals.m:
	Wrap an 80+ column line.
2004-01-30 06:00:45 +00:00
Fergus Henderson
f3e08a26d5 Another step towards supporting accurate GC for the LLDs back-end:
Estimated hours taken: 3
Branches: main

Another step towards supporting accurate GC for the LLDs back-end:
modify the LLDS code generator to allocate the proper forwarding pointer
slots for type_infos and typeclass_infos.

compiler/unify_gen.m:
compiler/code_info.m:
compiler/var_locn.m:
	When allocating type_infos or typeclass_infos on the heap,
	if accurate garbage collection is enabled then ensure that we
	reserve a word before the start of the object.  This word is
	used by the collector to store a forwarding pointer.
	For ordinary objects, we store the forwarding pointer in the
	old copy of the object, but we can't clobber the old copies of
	type_infos and typeclass_infos, since they might be used _during_
	garbage collection.
2004-01-08 06:52:36 +00:00
Zoltan Somogyi
599ef915d9 Instead of being relied on all over the place, centralize the compiler's
Estimated hours taken: 16
Branches: main

Instead of being relied on all over the place, centralize the compiler's
knowledge of the names of unify, compare and index predicates in one place,
special_pred.m. This should make it easy to change the naming scheme once
we switch over to compiler-generated type_ctor_infos for builtin types,
which will eliminate the runtime system's knowledge of the naming scheme.

compiler/hlds_pred.m:
	Add a field to pred_infos that says whether the predicate is a unify,
	compare or index predicate, and if so, for which type constructor.
	Code that used to test the predicate's name for __Unify__ etc now
	tests this field instead. Similarly the code that used to employ
	devious tricks to find out the type the unify/compare/index predicate
	is for.

compiler/rtti.m:
	Include this field in rtti_proc_labels as well as pred_infos.

compiler/make_hlds.m:
	Fill in this field as appropriate.

compiler/proc_label.m:
	Replace the predicate name with special_pred_id in the proc_labels
	of unify, index and compare preds.

compiler/special_pred.m:
	Narrow the interface to prevent reliance on the naming scheme
	for compiler-generated unify, compare and index predicates,
	except when absolutely necessary, i.e. when creating names for
	them.

	Narrow the mechanism required to reverse-engineer the type constructor
	a unify/compare/index predicate is for from the types to the
	functionality required by higher_order.m.

compiler/code_gen.m:
compiler/det_report.m:
compiler/higher_order.m:
compiler/intermod.m:
compiler/layout_out.m:
compiler/magic_util.m:
compiler/ml_code_util.m:
compiler/name_mangle.m:
compiler/opt_debug.m:
compiler/opt_util.m:
compiler/optimize.m:
compiler/polymorphism.m:
compiler/post_typecheck.m:
compiler/proc_label.m:
compiler/rl_exprn.m:
compiler/rl_key.m:
compiler/simplify.m:
compiler/termination.m:
compiler/typecheck.m:
compiler/unify_proc.m:
compiler/unused_args.m:
	Update code and comments to conform to the changes above.

compiler/hlds_out.m:
	Don't refer to the 'type' that a unify, compare or index predicate
	is for; refer to the type *constructor*.

compiler/mlds_to_java.m:
	Delete an unused predicate.

tests/invalid/purity/purity.err_exp:
	Update this expected output for the change in hlds_out.m.
2003-05-27 05:57:30 +00:00
Zoltan Somogyi
8e96ed11ac Add two new options that can help reduce the amount of clutter you have to
Estimated hours taken: 0.5
Branches: main

Add two new options that can help reduce the amount of clutter you have to
wade through when debugging.

doc/user_guide.texi:
compiler/options.m:
	Add two new options, --dump-hlds-pred-id and --debug-opt-pred-id.
	Both take an integer argument, and treat it as a pred_id.
	--dump-hlds-pred-id restricts all HLDS dumps to the specified pred,
	and --debug-opt-pred-id similarly restricts the output of --debug-opt
	to the specified pred.

compiler/hlds_out.m:
compiler/handle_options.m:
	Implement --dump-hlds-pred-id.

compiler/optimize.m:
	Implement --debug-opt-pred-id.
2003-05-10 05:03:58 +00:00
Zoltan Somogyi
92045bdc78 Simplify the handling of static ground terms in the LLDS backend.
Estimated hours taken: 5
Branches: main

Simplify the handling of static ground terms in the LLDS backend. Instead of
creating code, rtti and layout structures all containing create rvals and then
converting those rvals to static cells, create the static cells directly.

compiler/llds.m:
	Remove the create alternative from rvals, and the types used only by
	create.

	Delete the code handling the global_data type, which has been moved to
	global_data.m.

compiler/global_data.m:
	A new module handling static data structures for the LLDS backend.
	The basis of this module is the code that used to be in llds.m handling
	the global_data type, but this has been augmented to manage static
	cells as well as the data structures defined in rtti.m and layout.m.

	Also, rename the non_common_data field of global_data, which no longer
	makes sense, to refer to deep profiling, since it holds deep profiling
	data structures.

compiler/llds_common.m:
	Delete this file, since it is no longer needed. The operative part
	is now in global data.m; the rest (including the code to traverse code
	and data structures looking for create rvals) is no longer needed.

compiler/ll_backend.m:
	Delete the deleted module, and add the added module.
	XXX These changes should be also be documented in
	notes/compiler_design.html when Fergus finishes his changes
	to that file.

compiler/code_info.m:
	Add the database of static cells to the code generator state.

compiler/code_gen.m:
compiler/ll_pseudo_type_info.m:
compiler/lookup_switch.m:
compiler/mercury_compile.m:
compiler/stack_layout.m:
compiler/static_term.m:
compiler/string_switch.m:
compiler/unify_gen.m:
compiler/var_locn.m:
	Instead of creating create rvals, create static cells and return
	references to those cells. The static cell database ensures that we
	never create duplicate cells (unless --no-common-data forces us
	to do so). Pass around the static cell database.

compiler/code_util.m:
compiler/continuation_info.m:
compiler/dupelim.m:
compiler/exprn_aux.m:
compiler/jumpopt.m:
compiler/livemap.m:
compiler/llds_out.m:
compiler/middle_rec.m:
compiler/opt_debug.m:
compiler/opt_util.m:
compiler/optimize.m:
	Minor changes to conform to the above, mostly consisting of the
	deletion of code that handled create rvals.
2003-05-09 05:51:52 +00:00
Zoltan Somogyi
1cb657b998 Reduce inappropriate dependencies on ll_backend modules.
Estimated hours taken: 3
Branches: main

Reduce inappropriate dependencies on ll_backend modules. Except for
simplification of unnecessarily complicated logic in dependency_graph.m,
this change only moves functionality around.

compiler/llds_out.m:
compiler/c_util.m:
compiler/name_mangle.m:
	Move predicates that are used by multiple backends from
	ll_backend__llds_out to backend_libs__c_util and to a new module
	backend_libs__name_mangle. Make the relevant ones functions,
	and give some of them more meaningful names.

compiler/trace.m:
compiler/hlds_goal.m:
	Move a backend-independent predicate from ll_backend__trace
	to hlds__hlds_goal.

compiler/llds.m:
compiler/trace_params.m:
	Move the definition of the trace_port type from ll_backend__llds
	to libs__trace_params to avoid having libs__trace_params depend on
	ll_backend.

compiler/exprn_aux.m:
compiler/globals.m:
	Move the definition of the imported_is_constant from
	ll_backend__exprn_aux to libs__globals to avoid having libs__globals
	depend on ll_backend.

compiler/*.m:
	Conform to the above changes. This removes many inappropriate
	dependencies on the LLDS backend.
2003-03-16 08:01:31 +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
Zoltan Somogyi
4954da84cc Reduce the dependence of the MLDS backend on the LLDS backend by moving
Estimated hours taken: 2
Branches: main

Reduce the dependence of the MLDS backend on the LLDS backend by moving
functionality dealing with proc_labels from the LLDS backend (code_util.m)
to a new module, proc_label.m, which is part of backend_libs.

compiler/code_util.m:
compiler/proc_label.m:
	Move a type and some code from code_util to the new module. Convert
	predicates to functions as relevant. (The old code was written before
	functions were available).

compiler/backend_libs.m:
	Add proc_label to the list of submodules.

compiler/rtti.m:
	Rename a function to avoid a name clash with a function in
	proc_label.m.

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

	Ensure that all imports of modules in the compiler directory are on
	lines of their own, to make CVS merges easier. Sort the imports.
2003-03-14 08:10:12 +00:00
Zoltan Somogyi
ed83fe4623 Optimize shallow traced modules by not adding calls to MR_trace to shallow
Estimated hours taken: 12
Branches: main

Optimize shallow traced modules by not adding calls to MR_trace to shallow
traced procedures which cannot be called from a deep traced environment.
A shallow traced procedure can be optimized in this way if it is neither
exported from its defining module nor has its address taken.

The main purpose of this optimization is not the avoidance of the cost of the
MR_trace calls as much as it is the restoration of tail recursion optimization.
Previously, compiling a program in a debug grade would disable all tail
recursion in the program (since debug grades require at least shallow tracing
every module). This was a problem because it limited the sizes of the inputs
the debugged program could process before running out of memory. As long as
the procedures that recurse on the input are in the implementation section
of a shallow traced module, this should no longer happen.

compiler/trace_params.m:
	Introduce the concept of a procedure's effective trace level. This is
	identical to the global trace level, except if the procedure is not
	exported and doesn't have its address taken, and the global trace level
	is shallow. In that case, we say that the procedure's effective trace
	level is none.

	Computing a procedure's effective trace level requires its proc_info
	and its parent pred_info, so require callers to supply these as
	parameters.

compiler/code_info.m:
	Store the current pred_info as well as the current proc_info, for
	trace parameter lookups.

compiler/continuation_info.m:
compiler/code_gen.m:
	Record the required trace parameters of a procedure in its layout
	structure, since it can no longer be computed from the global trace
	level.

compiler/stack_layout.m:
	Use the trace parameters in procedures' layout structures, instead of
	trying to compute them from the global trace level.

compiler/inlining.m:
compiler/liveness.m:
compiler/stack_alloc.m:
compiler/store_alloc.m:
compiler/trace.m:
	Use procedures' effective trace level instead of the global trace level
	where relevant.

compiler/llds.m:
	Record the required trace parameter of a procedure in its c_procedure
	representation, since it can no longer be computed from the global
	trace level.

	Delete an obsolete field.

compiler/optimize.m:
compiler/jumpopt.m:
	Use a required trace parameter of a procedure in its c_procedure
	representation, since it can no longer be computed from the global
	trace level.

compiler/compile_target_code.m:
compiler/handle_options.m:
compiler/llds_out.m:
compiler/mercury_compile.m:
	Trivial changes to conform to updated interfaces.

compiler/stack_opt.m:
	Use the option opt_no_return_calls, instead of approximating it
	with the trace level. (The old code was a holdover from before the
	creation of the option.)

tests/debugger/shallow.m:
tests/debugger/shallow2.m:
tests/debugger/shallow.{inp,exp*}:
	Divide the old test case in shallow.m in two. The top level predicates
	stay in shallow.m and continue to be shallow traced. The two bottom
	predicates move to shallow2.m and are now deep traced.

	The new test input checks whether the debugger can walk across the
	stack frames of procedures in shallow traced modules whose effective
	trace level is "none" (such as queen/2).
2002-07-30 08:25:20 +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
Zoltan Somogyi
2980737352 A new LLDS->LLDS transformation that optimizes instruction sequences such
Estimated hours taken: 24
Branches: main

A new LLDS->LLDS transformation that optimizes instruction sequences such
as the following extract from tree234__search:

	MR_r1 = MR_stackvar(3);
	MR_r2 = MR_stackvar(4);
	MR_r3 = MR_const_field(MR_mktag(1), MR_stackvar(1), (MR_Integer) 2);
	MR_r4 = MR_stackvar(2);
	MR_succip = (MR_Code *) MR_stackvar(5);
	if ((MR_tag(MR_r3) != MR_mktag((MR_Integer) 1))) {
		MR_GOTO_LABEL(mercury__x3__search_3_0_i1);
	}
	MR_stackvar(1) = MR_r3;
	MR_stackvar(2) = MR_r4;
	MR_stackvar(3) = MR_r1;
	MR_stackvar(4) = MR_r2;
	MR_r2 = MR_r4;
	MR_r3 = MR_const_field(MR_mktag(1), MR_r3, (MR_Integer) 0);
	MR_call_localret(...)

The code before the if-then-else is part of the procedure epilogue; the code
after it is the code from the initial part of the procedure that fulljump
optimization replaces the self-tail-call with.

The transformation deletes the redundant assignments to stackvars 2, 3 and 4.
It reduces both the size and the runtime of the compiler by about 0.5%.

compiler/reassign.m:
	The new module that does the work.

compiler/optimize.m:
	Invoke the new module if the optimization is enabled. Invoke it after
	most other optimizations have been run, since they may create more
	opportunities for it.

compiler/option.m:
	Add a new option to control whether the new optimization is enabled.
	Turn on the new optimization at optimization level 3.

doc/user_guide.texi:
	Document the new option.

compiler/notes/compiler_design.html:
	Document the new module.
2002-03-13 01:01:15 +00:00
Simon Taylor
9c9601808d Add an alternative implementation of Mmake as part of the compiler.
Estimated hours taken: 500

Add an alternative implementation of Mmake as part of the compiler.
The advantages of this are
	- more accurate dependencies
	- no `mmake depend' step
	- less process creation (no processes are created to
		build interface files).

Still to do:
	- handle --split-c-files
	- handle the IL backend properly
	- library installation
	- allow the compiler to be built and the nightly tests
	  to be run with `mmc --make'

compiler/make.m:
	Control the build process.

compiler/make.program_target.m:
	Build executables and libraries.

compiler/make.module_target.m:
	Build C files, object files, interface files etc.

compiler/make.dependencies.m:
	Work out the depenendencies between targets.

compiler/make.module_dep_file.m:
	Record the inter-module dependencies between invocations of mmc.

compiler/make.util.m:
	Utility predicates used by `mmc --make'.

compiler/compile_target_code.m:
	This module will eventually contain the predicates used
	to compile the target code files generated by the compiler
	which are now in mercury_compile.m. (That will be done
	as a separate change for ease of reviewing).

	For now compile_target_code.m

compiler/mercury_compile.m:
	Export the predicates used to compile target code.

	Call make.m.

	Pass the name of the top-level module in the source file to modules.m.
	It is needed when generating the `.module_dep' files.

	Lookup the option defaults (which will eventually be stored in
	DEFAULT_MCFLAGS by the mmc script) before compiling. Up until now
	the option defaults have been passed on the command line by the
	mmc script, but with `mmc --make' the default options need
	to be overridden by the value of the MCFLAGS make variable, but
	the MCFLAGS make variable is overridden by command line options.

	Pass the value of `--link-flags' to c2init.

	Remove some uninformative messages printed when a C, IL, etc.
	compilation fails.

compiler/options_file.m:
	Read files containing Make style variable assignments.

compiler/options.m:
doc/user_guide.texi:
	Add a new options category: build system options.

	Add some extra options:
	--warn-undefined-options-variables - like mmake --warn-undefined-vars
	--verbose-commands - print commands that the user might be
		interested in, like C compilation, but not things
		like mercury_update_interface.
	--output-compile-error-lines - print the first n lines
		of the error file generated by a command.
	--generate-mmc-make-modules-dependencies - generate dependencies
		for use by `mmc --make' even when using Mmake.

	--il-assembler, --ilasm-flags, --mcpp-compiler, --mcpp-flags,
	--csharp-compiler, --csharp-flags, --install-prefix,
	--install-command, --libgrades, --options-files,
	--options-search-directories.

compiler/modules.m:
	Add fields to the `module_imports' type for use by make.*m.

	Don't try to fill in fields of the module_imports structure
	lazily. It's error prone, and probably doesn't save much
	anyway.

	Clean up the code to compute what foreign languages
	are used by a list of item.

	Simplify the handling of fact tables by recording that a module
	containing fact tables has foreign code to implement them,
	rather than requiring separate checks everywhere.

	Generalise predicates like get_interface so that they
	work even after the imported items have been read.

	Fix the handling of header files with the LLDS backend.

	Install the `.module_dep' files created for use by
	`mmc --make'.

compiler/*.m:
	Use record syntax rather than explicit deconstruction to
	refer to fields of the `module_imports' type.

compiler/*.m:
	Be more careful about where output goes.
	mercury_compile.m sets the output stream to be io__stderr_stream
	at the start of compilation, so remove all explicit writes to
	io__stderr_stream (with `--make' the error output stream may be
	a `.err' file, not io__stderr_stream).

	Change all occurrences of io__tell/io__told to use
	io__open_output/io__close_output (io__told restores the current
	output stream to io__stdout_stream, not the previous value).

compiler/passes_aux.m:
	Make the output from system commands go to the current
	output stream, not C stdout and stderr.

	Allow commands to be printed with `--verbose-commands'.

	Remove uninformative error messages when a command fails.

compiler/timestamp.m:
	Add functions oldest_timestamp and newest_timestamp.

compiler/llds_out.m:
	Record the number of C files written with `--split-c-files'
	in <module>.num_split.

compiler/prog_io.m:
compiler/*.m:
	`search_for_file' now returns the directory in which the
	file was found.

compiler/foreign.m:
	Use sub-typing to make some calls to predicates in this
	module `det' rather than `semidet'.

compiler/handle_options.m:
	Return the option arguments.

compiler/Mmakefile:
	make.util.m refers to kill() and `struct sigaction' which
	are not exported from <signal.h> unless `--no-ansi' is
	passed to gcc.

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

runtime/mercury_signal.h:
runtime/mercury_signal.c:
	Add a function MR_signal_should_restart() which alters
	whether a signal restarts or interrupts system calls.
	In general restarting is the preferred behaviour, but
	the wait() for a child process needs to be interruptible.

scripts/Mmake.vars.in:
	Add subdirs for `.module_dep', `.err_date'
	and `.num_split' files.

library/io.m:
	Add a version of io_call_system which returns the signal
	that killed the command rather than converting it into
	an error message.

	Add a predicate to interpret the result of system() or wait().

library/list.m:
	Add list__map_foldl2 and a unique mode for list__foldl3.

NEWS:
	Document the new library predicates.

configure.in:
runtime/mercury_conf.h.in:
	Check for siginterrupt().

doc/user_guide.texi:
	Document the new options.

	Add a description of `mmc --make' to the "Using Mmake" chapter.
2002-03-12 16:33:37 +00:00
Zoltan Somogyi
04e614485d Implement deep profiling; merge the changes on the deep2 branch back
Estimated hours taken: 500
Branches: main

Implement deep profiling; merge the changes on the deep2 branch back
onto the trunk.

The main documentation on the general architecture of the deep profiler
is the deep profiling paper.

doc/user_guide.texi:
	Document how to use the deep profiler.

deep_profiler:
deep_profiler/Mmakefile:
	A new directory holding the deep profiler and its mmakefile.

Mmakefile:
	Add targets for the new directory.

	Add support for removing inappropriate files from directories.

deep_profiler/interface.m:
	The deep profiler consists of two programs: mdprof_cgi.m, which acts
	as a CGI "script", and mdprof_server.m, which implements the server
	process that the CGI script talks to. Interface.m defines the
	interface between them.

script/mdprof.in:
	A shell script template. ../configure uses it to generate mdprof,
	which is a wrapper around mdprof_cgi that tells it how to find
	mdprof_server.

deep_profiler/mdprof_cgi.m:
	The CGI "script" program.

deep_profiler/mdprof_server.m:
	The top level predicates of the server.

deep_profiler/profile.m:
	The main data structures of the server and their operations.

deep_profiler/read_profile.m:
	Code for reading in profiling data files.

deep_profiler/startup.m:
	Code for post-processing the information in profiling data files,
	propagating costs from procedures to their ancestors and performing
	various kinds of summaries.

deep_profiler/server.m:
	Code for responding to requests from the CGI script.

deep_profiler/cliques.m:
	Code to find cliques in graphs.

deep_profiler/array_util.m:
deep_profiler/util.m:
	Utility predicates.

deep_profiler/dense_bitset.m:
	An implementation of (part of) the set ADT with dense bit vectors.

deep_profiler/measurements.m:
	Operations on profiling measurements.

deep_profiler/timeout.m:
	An implementation of a timeout facility.

deep_profiler/conf.m:
	Functions that depend on autoconfigured settings.

configure.in:
	Find out what command to use to find the name of the local host.

	Install deep profiling versions of the standard library along with the
	other profiling versions.

runtime/mercury_conf.h.in:
	Add some macros for deep_profiler/conf.m to use.

library/profiling_builtin.m:
runtime/mercury_deep_call_port_body.h:
runtime/mercury_deep_leave_port_body.h:
runtime/mercury_deep_redo_port_body.h:
	A new library module that implements deep profiling primitives.
	Some of these primitives have many versions, whose common code is
	factor is factored out in three new include files in the runtime.

compiler/deep_profiling.m:
	New module to perform the program transformations described in the
	paper.

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

compiler/mercury_compiler.m:
	Invoke the new module in deep profiling grades. Allow global static
	data to be generated by deep_profiling.m.

compiler/options.m:
	Add options to turn on deep profiling and (for benchmarking purposes)
	control its implementation.

	Add an optiooption disable tailcall optimization in the LLDS backend,
	to help benchmarking deep profiling.

compiler/jumpopt.m:
compiler/optimize.m:
	Obey the option to disable tailcalls.

compiler/handle_options.m:
	Handle the implications of deep profiling.

compiler/modules.m:
	In deep profiling grades, automatically import profiling_builtin.m.

compiler/prog_util.m:
doc/Makefile:
library/library.m:
	Handle the new builtin module.

compiler/export.m:
	In deep profiling grades, wrap deep profiling code around exported
	procedures to handle the "unscheduled call" aspects of callbacks to
	Mercury from the foreign language.

compiler/higher_order.m:
profiler/demangle.m:
util/demangle.c:
	When creating a name for a higher-order-specialized predicate, include
	the mode number in the name.

compiler/add_trail_ops.m:
compiler/type_util.m:
	Move c_pointer_type from add_trail_ops to type_util, so it can also be
	used by deep_profiling.m.

compiler/hlds_goal.m:
	Add a new goal feature that marks a tail call, for use by
	deep_profiling.m.

compiler/hlds_pred.m:
	Add a new field to proc_info structures for use by deep_profiling.m.

	Add a mechanism for getting proc_ids for procedure clones.

	Remove next_proc_id, an obsolete and unused predicate.

compiler/hlds_data.m:
	Add a new cons_id to refer to the proc_static structure of a procedure.

compiler/bytecode_gen.m:
compiler/code_util.m:
compiler/dependency_graph.m:
compiler/hlds_out.m:
compiler/mercury_to_mercury.m:
compiler/ml_unify_gen.m:
compiler/opt_debug.m:
compiler/prog_rep.m:
compiler/rl_exprn.m:
compiler/switch_util.m:
compiler/unify_gen.m:
	Trivial changes to handle the new cons_id, goal feature and/or
	proc_info argument.

compiler/rtti.m:
	Add a utility predicate for extracting pred_id and proc_id from an
	rtti_proc_label, for use by hlds_out.m

compiler/layout.m:
compiler/layout_out.m:
compiler/llds.m:
compiler/llds_common.m:
	Add support for proc_static and call_site_static structures.

compiler/layout_out.m:
compiler/llds_out.m:
	Add code for the output of proc_static structures.

compiler/code_util.m:
	Make code_util__make_proc_label_from_rtti a function, and export it.

util/mkinit.c:
compiler/llds_out.m:
compiler/layout.m:
compiler/modules.m:
	Add support for a fourth per-module C function, for writing out
	proc_static structures (and the call_site_static structures they
	contains).

	Since proc_static structures can be referred to from LLDS code (and not
	just from other static structures and compiler-generated C code),
	reorganize the declarations of static structures slightly.

	Change the schema for the name of the first per-module C function
	slightly, to make it the addition of the fourth function easier.
	The scheme now is:

		mercury__<modulename>__init
		mercury__<modulename>__init_type_tables
		mercury__<modulename>__init_debugger
		mercury__<modulename>__write_out_proc_statics

	Improve formatting of the generated C code.

library/*.m:
runtime/mercury.c:
runtime/mercury_context.c:
runtime/mercury_engine.c:
runtime/mercury_ho_call.c:
runtime/mercury_tabling.c:
runtime/mercury_trace_base.c:
runtime/mercury_wrapper.c:
trace/mercrury_trace.[ch]:
trace/mercrury_trace_declarative.c:
trace/mercrury_trace_external.c:
trace/mercrury_trace_internal.c:
	Conform to the new scheme for initialization functions for hand-written
	modules.

compiler/mercury_compile.m:
library/benchmarking.m:
runtime/mercury_conf_param.h:
runtime/mercury.h:
runtime/mercury_engine.c:
runtime/mercury_goto.c:
runtime/mercury_grade.h:
runtime/mercury_ho_call.c:
runtime/mercury_label.[ch]:
runtime/mercury_prof.[ch]:
	Add an MR_MPROF_ prefix in front of the C macros used to control the
	old profiler.

compiler/handle_options.m:
runtime/mercury_grade.h:
scripts/canonical_grade.sh-subr:
scripts/init_grade_options.sh-subr:
scripts/parse_grade_options.sh-subr:
	Make deep profiling completely separate from the old profiling system,
	by making the deep profiling grade independent of MR_MPROF_PROFILE_TIME
	and the compiler option --profile-time.

library/array.m:
library/builtin.m:
library/std_util.m:
runtime/mercury_hand_unify_body.h:
runtime/mercury_hand_compare_body.h:
	In deep profiling grades, wrap the deep profiling call, exit, fail
	and redo codes around the bodies of hand-written unification
	and comparison procedures.

	Make the reporting of array bounds violations switchable between
	making them fatal errors, as we currently, and reporting them by
	throwing an exception. Throwing an exception makes debugging code
	using arrays easier, but since exceptions aren't (yet) propagated
	across engine boundaries, we keep the old behaviour as the default;
	the new behaviour is for implementors.

runtime/mercury_deep_profiling_hand.h:
	New file that defines macros for use in Mercury predicates whose
	definition is in hand-written C code.

library/exception.m:
runtime/mercury_exception_catch_body.h:
runtime/mercury_stacks.h:
	In deep profiling grades, wrap the deep profiling call, exit, fail
	and redo codes around the bodies of the various modes of builtin_catch.

	Provide a function that C code can use to throw exceptions.

library/benchmarking.m:
library/exception.m:
library/gc.m:
library/std_util.m:
runtime/mercury_context.[ch]:
runtime/mercury_engine.[ch]:
runtime/mercury_debug.c:
runtime/mercury_deep_copy.c:
runtime/mercury_overflow.h:
runtime/mercury_regs.h:
runtime/mercury_stacks.h:
runtime/mercury_thread.c:
runtime/mercury_wrapper.c:
	Add prefixes to the names of the fields in the engine and context
	structures, to make code using them easier to understand and modify.

runtime/mercury_deep_profiling.[ch]:
	New module containing support functions for deep profiling and
	functions for writing out a deep profiling data file at the end of
	execution.

runtime/mercury_debug.[ch]:
	Add support for debugging deep profiling.

	Add support for watching the value at a given address.

	Make the buffered/unbuffered nature of debugging output controllable
	via the -du option.

	Print register contents only if -dr is specified.

runtime/mercury_goto.h:
runtime/mercury_std.h:
	Use the macros in mercury_std.h instead of defining local variants.

runtime/mercury_goto.h:
runtime/mercury_stack_layout.h:
runtime/mercury_stack_trace.c:
runtime/mercury_tabling.c:
trace/mercury_trace.c:
trace/mercury_trace_declarative.c:
trace/mercury_trace_external.c:
trace/mercury_trace_vars.c:
	Standardize some of the macro names with those used in the debugger
	paper.

runtime/mercury_heap.h:
	Add support for memory profiling with the deep profiler.

runtime/mercury_prof.[ch]:
runtime/mercury_prof_time.[ch]:
	Move the functionality that both the old profiler and the deep profiler
	need into the new module mercury_prof_time. Leave mercury_prof
	containing stuff that is only relevant to the old profiler.

runtime/mercury_prof.[ch]:
runtime/mercury_strerror.[ch]:
	Move the definition of strerror from mercury_prof to its own file.

runtime/mercury_wrapper.[ch]:
	Add support for deep profiling.

	Add suppory for controlling whether debugging output is buffered or
	not.

	Add support for watching the value at a given address.

runtime/Mmakefile:
	Mention all the added files.

scripts/mgnuc.in:
	Add an option for turning on deep profiling.

	Add options for controlling the details of deep profiling. These
	are not documented because they are intended only for benchmarking
	the deep profiler itself, for the paper; they are not for general use.

tools/bootcheck:
	Compile the deep_profiler directory as well as the other directories
	containing Mercury code.

	Turn off the creation of deep profiling data files during bootcheck,
	since all but one of these in each directory will be overwritten
	anyway.

	Add support for turning on --keep-objs by default in a workspace.

tools/speedtest:
	Preserve any deep profiling data files created by the tests.

trace/mercury_trace.c:
	Trap attempts to perform retries in deep profiling grades, since they
	would lead to core dumps otherwise.

util/Mmakefile:
	Avoid compile-time warnings when compiling getopt.

tests/*/Mmakefile:
tests/*/*/Mmakefile:
	In deep profiling grades, switch off the tests that test features
	that don't work with deep profiling, either by design or because
	the combination hasn't been implemented yet.
2001-05-31 06:00:27 +00:00
Zoltan Somogyi
7add5e0b0d Disable value numbering, now that it is no longer needed.
Estimated hours taken: 0.5
Branches: main

Disable value numbering, now that it is no longer needed. The value numbering
source files are not deleted from the CVS repository, since that would make
their restoration (in the unlikely event that this is needed) inconvenient,
but they will no longer be compiled or included in compiler executables.

doc/user_guide.texi:
compiler/options.m:
	Delete the options dealing with value numbering.

compiler/optimize.m:
	Do not invoke value numbering.

compiler/handle_options.m:
	Delete code that handles implications involving value numbering.

compiler/opt_debug.m:
	Delete code for debugging value numbering, since leaving it in
	would require importing value numbering modules and would thus drag
	them into the compiler executable.

compiler/value_number.m:
compiler/vn_block.m:
compiler/vn_cost.m:
compiler/vn_debug.m:
compiler/vn_filter.m:
compiler/vn_flush.m:
compiler/vn_order.m:
compiler/vn_table.m:
compiler/vn_temploc.m:
compiler/vn_type.m:
compiler/vn_util.m:
compiler/vn_verify.m:
	Delete these now obsolete modules.

compiler/notes/compiler_design.html:
	Delete mentions of value numbering and its modules.

tests/general/accumulator/Mmakefile:
tests/hard_coded/Mmakefile:
	Remove references to options removed by this change.
2001-05-15 07:12:04 +00:00
Zoltan Somogyi
9c58f97e3b Add a new optimization, --use-local-vars, to the LLDS backend.
Estimated hours taken: 20
Branches: main

Add a new optimization, --use-local-vars, to the LLDS backend. This
optimization is intended to replace references to fake registers and stack
slots with references to temporary variables in C code, since accessing these
should be cheaper.

With this optimization and one for delaying construction unifications,
the eager code generator should generate code at least good as that produced by
the old value numbering pass. This should make it possible to get rid of value
numbering, which is much harder to maintain.

compiler/use_local_vars.m:
	New module containing the optimization.

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

compiler/exprn_aux.m:
	Add new utility predicates for use by use_local_vars.

	If --debug-opt is specified, do not dump instruction sequences to
	standard output. Instead, put them in separate files, where they can be
	compared more easily.

compiler/options.m:
	Add the --use-local-vars option to control whether the use_local_vars
	pass gets run.

compiler/llds.m:
	Add liveness information to the c_code and pragma_foreign_code LLDS
	instructions, in order to allow use_local_vars to work in the presence
	of automatically-generated C code (e.g. by debugging).

compiler/livemap.m:
	Use the new liveness information to generate useful livemap information
	even in the presence of automatically generated C code.

compiler/code_gen.m:
compiler/code_info.m:
compiler/dupelim.m:
compiler/frameopt.m:
compiler/llds_common.m:
compiler/llds_out.m:
compiler/middle_rec.m:
compiler/opt_debug.m:
compiler/opt_util.m:
compiler/pragma_c_gen.m:
compiler/trace.m:
compiler/vn_block.m:
compiler/vn_cost.m:
compiler/vn_filter.m:
compiler/vn_verify.m:
	Provide and/or ignore this additional liveness information.

compiler/wrap_block.m:
	The post_value_number pass wraps LLDS instruction sequences
	using temporaries in a block instruction which actually declares
	those temporaries. It used to be used only by value numbering;
	it is now also used by use_local_vars. It has therefore been renamed
	and put in its own file.

compiler/optimize.m:
	Invoke use_local_vars if required, and call wrap_blocks instead of
	post_value_number.

compiler/value_number.m:
	Since the value numbering pass still cannot handle automatically
	generated C code, check for it explicitly now that livemap carries out
	only a weaker check.

compiler/basic_block.m:
	Add a module qualification.

library/set.m:
library/set_bbbtree.m:
library/set_ordlist.m:
library/set_unordlist.m:
	Add a new predicate, union_list, to each implementation of sets,
	for use by some of the new code above.

tests/general/array_test.m:
	Print out the result of each operation as soon as it is done, so that
	if you get a seg fault, you know which operations have completed and
	which haven't.
2001-04-24 03:59:13 +00:00
Zoltan Somogyi
c32e129db0 Add field names for the proc_layout_info type.
Estimated hours taken: 1

compiler/continuation_info.m:
	Add field names for the proc_layout_info type.

compiler/optimize.m:
	Use the new field names.
2000-08-21 09:42:01 +00:00
Zoltan Somogyi
12af7b3793 Consistently use counters to allocate label numbers and cell numbers
Estimated hours taken: 12

Consistently use counters to allocate label numbers and cell numbers
throughout the LLDS backend.

compiler/hlds_module.m:
	Change the module_info structure to store a counter instead of an
	integer for cell numbers.

compiler/llds.m:
	Change the c_procedure structure to include a proc_label and a counter,
	to allow LLDS to LLDS optimizations to use this counter to allocate
	new label numbers. (The labels also include the proc_label.)

compiler/code_info.m:
	Change the code_info structure to store counters instead of integers
	for both label numbers and cell numbers.

compiler/code_gen.m:
	When creating the c_procedure, copy the final value of the counter
	from code_info to the c_procedure.

compiler/opt_util.m:
	Delete the existing, inefficient procedure for allocating label
	numbers, and modify the interface of the get_prologue predicate
	to no longer return the proc_label (since it can now be looked up
	more directly).

compiler/*.m:
	Minor changes to conform to the new data structures and to use
	counters instead of direct addition.
2000-08-11 08:19:24 +00:00
Zoltan Somogyi
e46e2d5eb1 Remove calls to !.
Estimated hours taken: 0.5

library/*.m:
compiler/*.m:
	Remove calls to !.
2000-03-28 03:40:39 +00:00
Simon Taylor
17c24d9cf9 Restrict value numbering on procedures containing reconstructions.
Estimated hours taken: 1

Restrict value numbering on procedures containing reconstructions.
Without this change, value numbering could reorder instructions
which extract fields from a cell with the instructions which update
the values of those fields.

compiler/llds.m:
	Add a field to each `c_procedure' to record whether the
	procedure contains a reconstruction.

compiler/code_gen.m:
	Fill in the field.

compiler/value_number.m:
	Wrap labels around all field assignments in procedures which
	contain reconstructions.

compiler/*.m:
	Handle the extra field of the `c_procedure' constructor.
2000-02-10 04:37:40 +00:00
Zoltan Somogyi
0642a10ff8 Reduce the number of arguments of MR_trace() to one.
Estimated hours taken: 24

WARNING: this change affects binary compatibility for debuggable code;
the debuggable modules of the program and the runtime linked into the
executable must either all come from before this change, or they must all
come from after this change. However, this change does *not* affect binary
compatibility for non-debuggable executables.

Reduce the number of arguments of MR_trace() to one. Two of the arguments,
the port and the goal path, move into the label layout structure, as 16-bit
numbers; the port as a simple enumeration type, and the goal path as an
index into the module-wide string table. (The latter will eventually allow the
debugger to support the placement of breakpoints on labels with specific goal
paths.) The third argument, the number of the highest-numbered rN register in
use at the label, has been moved into the proc layout structure. In theory,
this will require more register saves and restores, since the number in the
proc layout is conservative (it is the max of the numbers that would be
required at the individual labels). However, this is not important, for two
reasons. First, we always save and restore all the rM registers that
appear in the mrM array before the last special-purpose register, and in
most cases this dictates how many registers we save/restore. Second, we
save/restore registers only when the debugger starts interaction, so
save/restore is a time critical activity only for the external debugger.

This change reduces the execution time of debuggable executables by about
4-5% when executing outside mdb and 3-4% when executing under mdb. It also
reduces executable sizes, but only by about 0.7% on x86.

This change eliminates the --trace-just-in-case compiler option, since
we now have the best of both --trace-just-in-case and --no-trace-just-in-case.

The drawback of this scheme is slightly increased executable size with the
accurage garbage collector, but that seems a small enough price to pay.

compiler/code_gen.m:
compiler/code_info.m:
	Record the number of the highest numbered rN register live at a trace
	label.

compiler/continuation_info.m:
	Record the number of the highest numbered rN register live at a trace
	label, and the port and goal path associated with the labels of trace
	events.

compiler/stack_layout.m:
	Put the number of the highest numbered rN register live at a trace
	label into proc layouts, and the port and goal path into label layouts.

	Since we are breaking binary compatibility with old debuggable modules
	anyway, compress the procedure id parts of proc layouts by using
	only 16 bits to store the procedure's arity and mode number, instead
	of 32 or 64.

compiler/trace.m:
	Update the handling of ports, goal paths and max live register numbers,
	so that instead of being passed as MR_trace arguments, they are
	recorded in data structures.

	Generate separate labels and layouts for the fail and redo events.
	Although they still have the same layout information, they now record
	different ports.

compiler/llds.m:
	Since trace.m now generates a label layout structure for the redo
	event, we must include redo events in the llds goal path type.

compiler/hlds_goal.m:
	Since the code for handling the port type for nondet pragma events
	has moved from the nondet-pragma-specific to the generic part of
	trace.m, we must now include their event types in the hlds goal path
	type.

compiler/llds_out.m:
	Add a predicate for converting ports into numbers, now that we
	must store ports in static data. Using their symbolic names would
	be better, but that would require complications in the llds type
	system, which would be inadvisable just before the release.

compiler/options.m:
compiler/handle_options.m:
doc/user_guide.texi:
	Eliminate --trace-just-in-case.

compiler/llds.m:
compiler/llds_common.m:
compiler/llds_out.m:
	Eliminate the data structure needed by --trace-just-in-case.

compiler/optimize.m:
	Trivial update to conform to data structure changes.

library/exception.m:
	Update the call to MR_trace.

runtime/mercury_stack_layout.h:
	Update the C structure declarations for the layout structures
	as discussed above.

runtime/mercury_init.h:
	Update the declarations of MR_trace_real and MR_trace_fake
	to use only one argument.

runtime/mercury_wrapper.[ch]:
	Update the declaration of MR_trace_func to use only one argument.

runtime/mercury_trace_base.[ch]:
	Update the declarations of MR_trace, MR_trace_real and MR_trace_fake
	to use only one argument.

	Delete MR_trace_struct(); since we deleted --trace-just-in-case, there
	will not be calls to it anymore.

	Since we are breaking binary compatibility anyway, move the exception
	port to be with the other interface ports. This should speed up a
	frequently executed test in the debugger.

	Update the handling of redo events.

trace/mercury_trace.h:
	Simplify and speed up the macro that tests a port for being an
	interface port, now that exceptions are grouped with other interface
	events.

trace/mercury_trace.c:
	Update the definition of MR_trace_real to use only one argument.
	The port is pulled out of the label layout structure only when
	needed to perform the termination tests for the current debugger
	command, and the goal path and the max live register number are
	looked up only when the termination test succeeds.
1999-12-14 04:54:38 +00:00
Zoltan Somogyi
e9fa3f8792 Fix two related bugs in the debugger. The first was that the code in jumpopt.m
Estimated hours taken: 3

Fix two related bugs in the debugger. The first was that the code in jumpopt.m
for preventing the redirecting of call returns away from labels with layout
structures was only partially effective, since some call return sites have
their layout structures generated only *after* optimization. The second bug
was that the exception events generated by library/exception.m took the label
layouts of call return sites within a predicate and passed them to MR_trace
as if they were the layouts of compiler-generated trace events. However,
while at compiler-generated trace events, all the variables mentioned in the
associated layout structure are supposed to be live, at return sites only
the variables stored in stack slots are live.

compiler/jumpopt.m:
	Do not redirect call returns if execution tracing is enabled.

compiler/optimize.m:
	Pass the trace level to jumpopt.m.

trace/mercury_trace_vars.[ch]:
	Remember the port type of the event, and do not consider the registers
	to contain valid contents even at ancestor level zero if the port type
	is exception.

trace/mercury_trace_{in,ex}ternal.c:
	Pass the port type to mercury_trace_vars.c.

tests/debugger/exception_vars.{m,inp,exp,exp2}:
	Regression test for the fixed bugs. The .exp2 file is not yet filled
	in.

tests/debugger/Mmakefile:
	Enable the new test case.
1999-12-10 04:24:09 +00:00
Zoltan Somogyi
f0964815a3 Support line numbers in the debugger. You now get contexts (filename:lineno
Estimated hours taken: 40

Support line numbers in the debugger. You now get contexts (filename:lineno
pairs) printed in several circumstances, and you can put breakpoints on
contexts, when they correspond to trace events or to calls. The latter are
implemented as breakpoints on the label layouts of the return sites.

This required extending the debugging RTTI, so that associated with each
module there is now a new data structure listing the source file names that
contribute labels with layout structures to the code of the module. For each
such source file, this table gives a list of all such labels arising from
that file. The table entry for a label gives the line number within the file,
and the pointer to the label layout structure.

compiler/llds.m:
	Add a context field to the call instruction.

compiler/continuation_info.m:
	Instead of the old division of continuation info about labels into
	trace ports and everything else, divide them into trace ports, resume
	points and return sites. Record contexts with trace ports, and record
	contexts and called procedure information with return sites.

compiler/code_info.m:
	Conform to the changes in continuation_info.m.

compiler/options.m:
	Add a new option that allows us to disable the generation of line
	number information for size benchmarking (it has no other use).

compiler/stack_layout.m:
	Generate the new components of the RTTI, unless the option says not to.

compiler/code_gen.m:
compiler/pragma_c_gen.m:
compiler/trace.m:
	Include contexts in the information we gather for the layouts
	associated with the events we generate.

compiler/call_gen.m:
	Include contexts in the call LLDS instructions, for association
	with the return site's label layout structure (which is done after
	code generation is finished).

compiler/handle_options.m:
	Delete the code that tests or sets the deleted options.

compiler/mercury_compile.m:
	Delete the code that tests the deleted options.

compiler/basic_block.m:
compiler/dupelim.m:
compiler/frameopt.m:
compiler/livemap.m:
compiler/llds_common.m:
compiler/llds_out.m:
compiler/middle_rec.m:
compiler/opt_debug.m:
compiler/opt_util.m:
compiler/value_number.m:
compiler/vn_*.m:
	Trivial changes to conform to the changes to llds.m.

compiler/jumpopt.m:
	Do not optimize away jumps to labels with layout structures.
	The jumps we are particularly concerned about now are the jumps
	that return from procedure calls. Previously, it was okay to redirect
	returns from several calls so that all go to the same label, since
	the live variable information associated with the labels could be
	merged. However, we now also associate line numbers with calls, and
	these cannot be usefully merged.

compiler/optimize.m:
	Pass the information required by jumpopt to it.

doc/user_guide.texi:
	Document that you can now break at line numbers.

	Document the new "context" command, and the -d or --detailed option
	of the stack command and the commands that set ancestor levels.

runtime/mercury_stack_layout.h:
	Extend the module layout structure definition with the new tables.

	Remove the conditional facility for including label numbers in label
	layout structures. It hasn't been used in a long time, and neither
	Tyson or me expect to use it to debug either gc or the debugger itself,
	so it has no uses left; the line numbers have superseded it.

runtime/mercury_stack_trace.[ch]:
	Extend the code to print stack traces to also optionally print
	contexts.

	Add some utility predicates currently used by the debugger that could
	also be use for debugging gc or for more detailed stack traces.

trace/mercury_trace_internal.c:
	Implement the "break <context>" command, the "context" command, and
	the -d or --detailed option of the stack command and the commands
	that set ancestor levels.

	Conditionally define a conditionally used variable.

trace/mercury_trace_external.c:
	Minor changes to keep up with the changes to stack traces.

	Delete an unused variable.

trace/mercury_trace_spy.[ch]:
	Check for breakpoints on contexts.

trace/mercury_trace_tables.[ch]:
	Add functions to search the RTTI data structures for labels
	corresponding to a given context.

trace/mercury_trace_vars.[ch]:
	Remember the context of the current environment.

tests/debugger/queen.{inp,exp}:
	Test the new capabilities of the debugger.

tests/debugger/*.{inp,exp}:
	Update the expected output of the debugger to account for contexts.
	In some cases, modify the input script to put contexts where they don't
	overflow lines.
1999-11-15 00:43:59 +00:00
Zoltan Somogyi
0b35ee3f56 Add a new option, --checked-nondet-tailcalls, that enables the use of
Estimated hours taken: 8

Add a new option, --checked-nondet-tailcalls, that enables the use of
Prolog style nondet tail calls (which check whether the current frame is
on top of the nondet stack and only do a tail call if it is).

This option is not likely to help Mercury code, since most of the time
the test will fail, which means we incurred its cost and did not gain
the benefit of the tailcall. However, HAL often has predicates that are
declared nondet but are det or semidet most of the time, and these can
benefit.

compiler/options.m:
doc/user_guide.texi:
	Add the new option, which is not on by default and is not turned on
	at any optimization level; you have to give it explicitly.

compiler/llds.m:
	Modify the call_model type to distinguish the new style nondet tail
	call from the old (which does not do a runtime test).

compiler/code_info.m:
	Check the fail state whether it is suitable for new style nondet
	tail calls.

compiler/call_gen.m:
	Put the result from code_info.m into the generated LLDS.

compiler/jumpopt.m:
	Use the new status field in the LLDS to perform the optimization,
	if the option is given.

	Document the main predicate and its new argument.

compiler/optimize.m:
	Pass the value of the new option to jumpopt.

tests/hard_coded/checked_nondet_tailcall.{m,exp}:
	A new test case to check that the code we generate with the new
	option works correctly. (Checking whether it actually reduces
	nondet stack usage would be harder.)
1999-09-30 08:55:51 +00:00
Fergus Henderson
d66c8481ae Some more changes to minimize the complexity of the intermodule dependencies.
Estimated hours taken: 4

Some more changes to minimize the complexity of the intermodule dependencies.
In particular, ensure that hlds_module.m does not need to import llds.m.

compiler/hlds_module.m:
compiler/llds.m:
	Move the definition of the c_interface_info type (and the types
	used for all its fields) from llds.m into hlds_module.m, since
	this type contains high-level information about the user-level
	C interface stuff that is not directly related to the LLDS and
	is needed by other back-ends.

compiler/hlds_module.m:
compiler/llds.m:
compiler/mercury_compile.m:
compiler/code_gen.m:
compiler/stack_layout.m:
compiler/table_gen.m:
	Move the `global_data' type from hlds_module.m into llds.m,
	since this type contains low-level stuff that is dependent on
	the LLDS.  Delete the `global_data' field of the module_info,
	instead passing it around as a separate argument where needed.
	Move the code for inserting llds__tabling_pointer_vars into the
	global_data from table_gen.m to code_gen.m, since this is
	dependent on the LLDS and table_gen.m should be a pure
	HLDS->HLDS transformation, so that it can work with other
	back-ends.

compiler/continuation_info.m:
	Update some comments which this change makes obsolete.

compiler/optimize.m:
	Delete the import of module hlds_data, since it is no longer needed.
1999-07-12 06:21:25 +00:00
Zoltan Somogyi
e33efd211a Allow the native collector to work for nondet code, by generating layout
Estimated hours taken: 10

Allow the native collector to work for nondet code, by generating layout
structures for the resumption points whose addresses can be put into
redoip slots in nondet stack frames.

If the program is compiled with both native gc and debugging, entries
to disjunctions will have two labels and two layout structures, one
for gc and one for the debugger. At the moment we make no attempt
to try to combine the two structures, since doing so would add significant
extra complexity. Optimizing this option combination will not be important
for a while yet anyway.

compiler/code_info.m:
	Update the code that generates resume points to also optionally
	generate layout structures for the stack labels.

compiler/disj_gen.m:
	When we save the heap pointer, update not only the current code_info
	but the saved code_info that represents the branch start position
	as well, since the slot containing the saved heap pointer will be
	live in each of the following disjuncts.

compiler/labelopt.m:
compiler/mercury_compile.m:
compiler/optimize.m:
compiler/value_number.m:
	Arrange to pass the global_data structure to the label elimination
	and value numbering passes. This is to (a) prevent the label
	elimination pass from removing labels (e.g. stack resume labels)
	that have layout structures, and (b) to prevent value numbering
	for moving computations across such labels, since that would
	invalidate the layout structure.

	(The presence of pragma_c_code fragments in the generated code avoids
	both these potential problems for layout structures that correspond
	to trace events, but that solution would be suboptimal for resume
	labels.)

compiler/hlds_module.m:
	Add a utility predicate needed by optimize.m.
1999-03-12 05:53:29 +00:00
Tyson Dowd
319d1952f9 Turn off frame optimizations for accurate GC.
Estimated hours taken: 2

Turn off frame optimizations for accurate GC.
We need the stack frames present so we can replace the succip on the
stack to schedule accurate GC.

compiler/handle_options.m:
	Make accurate GC imply --no-optimize-frames.

compiler/optimize.m:
compiler/peephole.m:
compiler/value_number.m:
	If doing accurate GC, don't peephole optimize incr_sp...decr_sp
	code.
1998-06-16 06:11:42 +00:00
Fergus Henderson
11d8161692 Add support for nested modules.
Estimated hours taken: 50

Add support for nested modules.

- module names may themselves be module-qualified
- modules may contain `:- include_module' declarations
  which name sub-modules
- a sub-module has access to all the declarations in the
  parent module (including its implementation section).

This support is not yet complete; see the BUGS and LIMITATIONS below.

LIMITATIONS
- source file names must match module names
	(just as they did previously)
- mmc doesn't allow path names on the command line any more
	(e.g. `mmc --make-int ../library/foo.m').
- import_module declarations must use the fully-qualified module name
- module qualifiers must use the fully-qualified module name
- no support for root-qualified module names
	(e.g. `:parent:child' instead of `parent:child').
- modules may not be physically nested (only logical nesting, via
  `include_module').

BUGS
- doesn't check that the parent module is imported/used before allowing
	import/use of its sub-modules.
- doesn't check that there is an include_module declaration in the
	parent for each module claiming to be a child of that parent
- privacy of private modules is not enforced

-------------------

NEWS:
	Mention that we support nested modules.

library/ops.m:
library/nc_builtin.nl:
library/sp_builtin.nl:
compiler/mercury_to_mercury.m:
	Add `include_module' as a new prefix operator.
	Change the associativity of `:' from xfy to yfx
	(since this made parsing module qualifiers slightly easier).

compiler/prog_data.m:
	Add new `include_module' declaration.
	Change the `module_name' and `module_specifier' types
	from strings to sym_names, so that module names can
	themselves be module qualified.

compiler/modules.m:
	Add predicates module_name_to_file_name/2 and
	file_name_to_module_name/2.
	Lots of changes to handle parent module dependencies,
	to create parent interface (`.int0') files, to read them in,
	to output correct dependencies information for them to the
	`.d' and `.dep' files, etc.
	Rewrite a lot of the code to improve the readability
	(add comments, use subroutines, better variable names).
	Also fix a couple of bugs:
	- generate_dependencies was using the transitive implementation
	  dependencies rather than the transitive interface dependencies
	  to compute the `.int3' dependencies when writing `.d' files
	  (this bug was introduced during crs's changes to support
	  `.trans_opt' files)
	- when creating the `.int' file, it was reading in the
	  interfaces for modules imported in the implementation section,
	  not just those in the interface section.
	  This meant that the compiler missed a lot of errors.

library/graph.m:
library/lexer.m:
library/term.m:
library/term_io.m:
library/varset.m:
compiler/*.m:
	Add `:- import_module' declarations to the interface needed
	by declarations in the interface.  (The previous version
	of the compiler did not detect these missing interface imports,
	due to the above-mentioned bug in modules.m.)

compiler/mercury_compile.m:
compiler/intermod.m:
	Change mercury_compile__maybe_grab_optfiles and
	intermod__grab_optfiles so that they grab the opt files for
	parent modules as well as the ones for imported modules.

compiler/mercury_compile.m:
	Minor changes to handle parent module dependencies.
	(Also improve the wording of the warning about trans-opt
	dependencies.)

compiler/make_hlds.m:
compiler/module_qual.m:
	Ignore `:- include_module' declarations.

compiler/module_qual.m:
	A couple of small changes to handle nested module names.

compiler/prog_out.m:
compiler/prog_util.m:
	Add new predicates string_to_sym_name/3 (prog_util.m) and
	sym_name_to_string/{2,3} (prog_out.m).

compiler/*.m:
	Replace many occurrences of `string' with `module_name'.
	Change code that prints out module names or converts
	them to strings or filenames to handle the fact that
	module names are now sym_names intead of strings.
	Also change a few places (e.g. in intermod.m, hlds_module.m)
	where the code assumed that any qualified symbol was
	fully-qualified.

compiler/prog_io.m:
compiler/prog_io_goal.m:
	Move sym_name_and_args/3, parse_qualified_term/4 and
	parse_qualified_term/5 preds from prog_io_goal.m to prog_io.m,
	since they are very similar to the parse_symbol_name/2 predicate
	already in prog_io.m.  Rewrite these predicates, both
	to improve maintainability, and to handle the newly
	allowed syntax (module-qualified module names).
	Rename parse_qualified_term/5 as `parse_implicit_qualified_term'.

compiler/prog_io.m:
	Rewrite the handling of `:- module' and `:- end_module'
	declarations, so that it can handle nested modules.
	Add code to parse `include_module' declarations.

compiler/prog_util.m:
compiler/*.m:
	Add new predicates mercury_public_builtin_module/1 and
	mercury_private_builtin_module/1 in prog_util.m.
	Change most of the hard-coded occurrences of "mercury_builtin"
	to call mercury_private_builtin_module/1 or
	mercury_public_builtin_module/1 or both.

compiler/llds_out.m:
	Add llds_out__sym_name_mangle/2, for mangling module names.

compiler/special_pred.m:
compiler/mode_util.m:
compiler/clause_to_proc.m:
compiler/prog_io_goal.m:
compiler/lambda.m:
compiler/polymorphism.m:
	Move the predicates in_mode/1, out_mode/1, and uo_mode/1
	from special_pred.m to mode_util.m, and change various
	hard-coded definitions to instead call these predicates.

compiler/polymorphism.m:
	Ensure that the type names `type_info' and `typeclass_info' are
	module-qualified in the generated code.  This avoids a problem
	where the code generated by polymorphism.m was not considered
	type-correct, due to the type `type_info' not matching
	`mercury_builtin:type_info'.

compiler/check_typeclass.m:
	Simplify the code for check_instance_pred and
	get_matching_instance_pred_ids.

compiler/mercury_compile.m:
compiler/modules.m:
	Disallow directory names in command-line arguments.

compiler/options.m:
compiler/handle_options.m:
compiler/mercury_compile.m:
compiler/modules.m:
	Add a `--make-private-interface' option.
	The private interface file `<module>.int0' contains
	all the declarations in the module; it is used for
	compiling sub-modules.

scripts/Mmake.rules:
scripts/Mmake.vars.in:
	Add support for creating `.int0' and `.date0' files
	by invoking mmc with `--make-private-interface'.

doc/user_guide.texi:
	Document `--make-private-interface' and the `.int0'
	and `.date0' file extensions.

doc/reference_manual.texi:
	Document nested modules.

util/mdemangle.c:
profiler/demangle.m:
	Demangle names with multiple module qualifiers.

tests/general/Mmakefile:
tests/general/string_format_test.m:
tests/general/string_format_test.exp:
tests/general/string__format_test.m:
tests/general/string__format_test.exp:
tests/general/.cvsignore:
	Change the `:- module string__format_test' declaration in
	`string__format_test.m' to `:- module string_format_test',
	because with the original declaration the `__' was taken
	as a module qualifier, which lead to an error message.
	Hence rename the file accordingly, to avoid the warning
	about file name not matching module name.

tests/invalid/Mmakefile:
tests/invalid/missing_interface_import.m:
tests/invalid/missing_interface_import.err_exp:
	Regression test to check that the compiler reports
	errors for missing `import_module' in the interface section.

tests/invalid/*.err_exp:
tests/warnings/unused_args_test.exp:
tests/warnings/unused_import.exp:
	Update the expected diagnostics output for the test cases to
	reflect a few minor changes to the warning messages.

tests/hard_coded/Mmakefile:
tests/hard_coded/parent.m:
tests/hard_coded/parent.child.m:
tests/hard_coded/parent.exp:
tests/hard_coded/parent2.m:
tests/hard_coded/parent2.child.m:
tests/hard_coded/parent2.exp:
	Two simple tests case for the use of nested modules with
	separate compilation.
1998-03-03 17:48:14 +00:00
Fergus Henderson
73131e8df3 Undo Zoltan's bogus update of all the copyright dates.
Estimated hours taken: 0.75

library/*.m:
compiler/*.m:
	Undo Zoltan's bogus update of all the copyright dates.
	The dates in the copyright header should reflect the years
	in which the file was modified (and no, changes to the
	copyright header itself don't count as modifications).
1998-01-23 12:57:08 +00:00
Zoltan Somogyi
bb4442ddc1 Update copyright dates for 1998.
Estimated hours taken: 0.5

compiler/*.m:
	Update copyright dates for 1998.
1998-01-13 10:06:08 +00:00
Zoltan Somogyi
42c540ad67 Give duplicate code elimination more teeth in dealing with similar arguments
Estimated hours taken: 20

Give duplicate code elimination more teeth in dealing with similar arguments
of different function symbols. For the source code

	:- type t1	--->	f(int)
			;	g(int, int).

	:- pred p1(t1::in, int::out) is det.

	p1(f(Y), Y).
	p1(g(Y, _), Y).

we now generate the C code

	Define_entry(mercury__xdup__p1_2_0);
		r1 = const_mask_field(r1, (Integer) 0);
		proceed();

thus avoiding the cost of testing the function symbol.

runtime/mercury_tags.h:
	Add two new macros, mask_field and const_mask_field, that behave
	just like field and const_field except that instead of stripping
	off a known tag from the pointer, they strip (mask) off an unknown
	tag.

compiler/llds.m:
	Change the first argument of the lval field/3 from tag to maybe(tag).

	Make the comments on some types more readable.

compiler/llds_out.m:
	If the first arg of the lval field/3 is no, emit a (const_)mask_field
	macro; otherwise, emit a (const_)field macro.

compiler/basic_block.m:
	New module to convert sequences of instructions to sequences of
	basic blocks and vice versa. Used in the new dupelim.m.

compiler/dupelim.m:
	Complete rewrite to give duplicate code elimination more teeth.
	Whereas previously we eliminated blocks of code only if they exactly
	duplicated other blocks of code, we now look for blocks that can be
	"anti-unified". For example, the blocks

	r1 = field(mktag(0), r2, 0)
	goto L1

	and

	r1 = field(mktag(1), r2, 0)
	<fall through to L1>

	anti-unify, with the most specific common generalization being

	r1 = mask_field(r2, 0)
	goto L1

	If several basic blocks antiunify, we replace one copy with the
	antiunified block and try to eliminate the others. We do not
	eliminate blocks that can be fallen into, since eliminating them
	would require introducing a goto, which would slow the code down.

compiler/peephole,m:
	If a conditional branch to a label is followed by that label or
	by an unconditional branch to that label, eliminate the branch.
	Dupelim produces this kind of code.

compiler/{code_exprn,exprn_aux,lookup_switch,opt_debug,unify_gen}.m:
	Minor changes required by the change to field/3.

compiler/{frameopt,jumpopt,labelopt,mercury_compile,optimize,value_number}.m:
	s/__main/_main/ in predicate names.

compiler/jumpopt.m:
	Add some documentation.

compiler/unify_gen.m:
	Fix a module qualified predicate name reference that would not
	work in Prolog.

compiler/notes/compiler_design.html:
	Document the new file basic_block.m.
1997-12-22 06:59:25 +00:00
Tyson Dowd
24954933b5 Fix some problems Fergus pointed out after reviewing my
Estimated hours taken: 1

Fix some problems Fergus pointed out after reviewing my
stack layouts change.

compiler/continuation_info.m:
	Separate library imports from compiler imports.

compiler/handle_options.m:
compiler/options.m:
	Add some comments to explain the stack_layouts option.
	Comment out the documentation of the stack-layouts option,
	as it is a developer only option.

compiler/code_gen.m:
compiler/llds.m:
compiler/llds_common.m:
compiler/llds_out.m:
compiler/mercury_compile.m:
compiler/optimize.m:
	Remove llds_proc_id from c_procedure, as pred_proc_id is
	available instead.
1997-12-10 07:15:49 +00:00
Tyson Dowd
2a97f96d1a Generate stack layouts for accurate garbage collection.
Estimated hours taken: 50

Generate stack layouts for accurate garbage collection.

compiler/base_type_layout.m:
	Change the order of some arguments so that threaded data
	structures are more often in the final two arguments (allows
	easy use of higher order predicates).
	Simplify some code using higher order preds.
	Export base_type_layout__construct_pseudo_type_info, as
	stack_layout.m needs to be able to generate pseudo_type_infos
	too.
	Fix problems with cell numbers being re-used -- get the next
	cell number from module_info, and update module_info
	after processing base_type_layouts.

compiler/code_gen.m:
	Add information about each procedure to the continuation info.
	Handle new field in c_procedure.

compiler/continuation_info.m:
	Redesign most of this module to deal with labels
	that are continuation points for multiple calls.
	Change the order of some arguments so that threaded data
	structures are in the final two arguments.
	Cleaned up and documented code.

compiler/dupelim.m:
compiler/exprn_aux.m:
	Handle new label_entry data type.

compiler/export.m:
compiler/opt_debug.m:
	Handle new label_entry and general data types.

compiler/llds_out.m:
	Add an argument to get_proc_label to control whether a
	"mercury_" prefix is wanted.
	Handle new label_entry and general data types.

compiler/llds.m:
	Add a new alternative for data_const - a label_entry.
	Add a new alternative for data_name - general, which
	allows any sort of data, with names generated elsewhere.
	Add the pred_proc_id as a field of c_procedure.

compiler/optimize.m:
compiler/llds_common.m:
compiler/optimize.m:
	Handle new field in c_procedure.

compiler/mercury_compile.m:
	Generate layout information after code has been generated,
	and output stack layouts.

compiler/notes/compiler_design.html:
	Document new stack_layout module.

compiler/stack_layout.m:
	New file - generates the LLDS code that defines
	global constants to hold the stack_layout structures.

compiler/options.m:
compiler/handle_options.m:
	Add --stack-layout option which outputs stack layouts.
	Make accurate gc imply stack_layout.
1997-11-08 13:12:08 +00:00
Fergus Henderson
04b720630b Update the copyright messages so that (a) they contain the correct years
and (b) they say "Copyright (C) ... _The_ University of Melbourne".
1997-07-27 15:09:59 +00:00
Tyson Dowd
cbcb23d17b Enable --warn-interface-imports by default.
Estimated hours taken: 3

Enable --warn-interface-imports by default. This was turned off while
list and term were defined in mercury_builtin.m, since it caused many
warnings.

Fix all the unused interface imports that have been added since then.

compiler/options.m:
	Enable --warn-interface-imports by default.

compiler/module_qual.m:
	Fix formatting inconsistencies with module names in warning
	messages. (".m" was not appended to module names if there was
	only one module).

compiler/*.m:
library/*.m:
tests/invalid/type_loop.m:
tests/warnings/*.m:
	Remove usused interface imports, or move them into
	implementation (mostly bool, list and std_util).
1997-05-21 02:16:53 +00:00