Commit Graph

44 Commits

Author SHA1 Message Date
Zoltan Somogyi
d49f6eab84 Add missing imports of parent modules.
These imports were missing from source files, but were included in imported
modules' .int3 files. An upcoming change will delete these from those .int3
files.
2019-03-20 03:57:10 +11:00
Zoltan Somogyi
15aa457e12 Delete $module arg from calls to unexpected. 2018-04-07 18:25:43 +10:00
Zoltan Somogyi
8a4bd3e454 Convert (C->T;E) to (if C then T else E). 2015-10-25 08:17:42 +11:00
Zoltan Somogyi
13b6f03f46 Module qualify end_module declarations.
compiler/*.m:
    Module qualify the end_module declarations. In some cases, add them.

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

compiler/add_pragma.m:
    Give some predicates more meaningful names.
2014-09-04 00:24:52 +02:00
Zoltan Somogyi
7c5fe1e988 Record the number of instructions in each basic block.
Estimated hours taken: 1
Branches: main

compiler/basic_block.m:
	Record the number of instructions in each basic block.

compiler/use_local_vars.m:
	Do not perform this quadratic optimization on basic blocks
	on which it would take too long.

compiler/dupelim.m:
	Don't try to detect duplicates in big blocks; the attempt is expensive,
	and also very likely to fail. (Big blocks are unlikely to duplicated;
	the optimization was meant for redundant copies of the procedure
	epilogue.)

compiler/livemap.m:
	Put a limit on the number of iterations done by the fixpoint algorithm.
2011-05-25 08:04:27 +00:00
Zoltan Somogyi
295415090e Convert almost all remaining modules in the compiler to use
Estimated hours taken: 6
Branches: main

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

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	contained an incorrect, out-of-date or cut-and-pasted predicate name.

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

Change the argument ordering of predicates in the set module.

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

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

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

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

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

NEWS:
	Announce the above changes.
2011-05-06 05:03:29 +00:00
Julien Fischer
9f68c330f0 Change the argument order of many of the predicates in the map, bimap, and
Branches: main

Change the argument order of many of the predicates in the map, bimap, and
multi_map modules so they are more conducive to the use of state variable
notation, i.e. make the order the same as in the sv* modules.

Prepare for the deprecation of the sv{bimap,map,multi_map} modules by
removing their use throughout the system.

library/bimap.m:
library/map.m:
library/multi_map.m:
	As above.
NEWS:
	Announce the change.

	Separate out the "highlights" from the "detailed listing" for
	the post-11.01 NEWS.

	Reorganise the announcement of the Unicode support.

benchmarks/*/*.m:
browser/*.m:
compiler/*.m:
deep_profiler/*.m:
extras/*/*.m:
mdbcomp/*.m:
profiler/*.m:
tests/*/*.m:
ssdb/*.m:
samples/*/*.m
slice/*.m:
	Conform to the above change.

	Remove any dependencies on the sv{bimap,map,multi_map} modules.
2011-05-03 04:35:04 +00:00
Zoltan Somogyi
1c3bc03415 Make the system compiler with --warn-unused-imports.
Estimated hours taken: 2
Branches: main, release

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

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

	In some files, do some minor cleanup along the way.
2010-12-30 11:18:04 +00:00
Zoltan Somogyi
8a28e40c9b Add the predicates sorry, unexpected and expect to library/error.m.
Estimated hours taken: 2
Branches: main

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

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

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

compiler/*.m:
	Change imports as needed.

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

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

NEWS:
	Mention the new predicates in the standard library.
2010-12-15 06:30:36 +00:00
Zoltan Somogyi
672f77c4ec Add a new compiler option. --inform-ite-instead-of-switch.
Estimated hours taken: 20
Branches: main

Add a new compiler option. --inform-ite-instead-of-switch. If this is enabled,
the compiler will generate informational messages about if-then-elses that
it thinks should be converted to switches for the sake of program reliability.

Act on the output generated by this option.

compiler/simplify.m:
	Implement the new option.

	Fix an old bug that could cause us to generate warnings about code
	that was OK in one duplicated copy but not in another (where a switch
	arm's code is duplicated due to the case being selected for more than
	one cons_id).

compiler/options.m:
	Add the new option.

	Add a way to test for the bug fix in simplify.

doc/user_guide.texi:
	Document the new option.

NEWS:
	Mention the new option.

library/*.m:
mdbcomp/*.m:
browser/*.m:
compiler/*.m:
deep_profiler/*.m:
	Convert if-then-elses to switches at most of the sites suggested by the
	new option. At the remaining sites, switching to switches would have
	nontrivial downsides. This typically happens with the switched-on type
	has many functors, and we treat one or two specially (e.g. cons/2 in
	the cons_id type).

	Perform misc cleanups in the vicinity of the if-then-else to switch
	conversions.

	In a few cases, improve the error messages generated.

compiler/accumulator.m:
compiler/hlds_goal.m:
	(Rename and) move insts for particular kinds of goal from
	accumulator.m to hlds_goal.m, to allow them to be used in other
	modules. Using these insts allowed us to eliminate some if-then-elses
	entirely.

compiler/exprn_aux.m:
	Instead of fixing some if-then-elses, delete the predicates containing
	them, since they aren't used, and (as pointed out by the new option)
	would need considerable other fixing if they were ever needed again.

compiler/lp_rational.m:
	Add prefixes to the names of the function symbols on some types,
	since without those prefixes, it was hard to figure out what type
	the switch corresponding to an old if-then-else was switching on.

tests/invalid/reserve_tag.err_exp:
	Expect a new, improved error message.
2007-11-23 07:36:01 +00:00
Zoltan Somogyi
ba93a52fe7 This diff changes a few types from being defined as equivalent to a pair
Estimated hours taken: 10
Branches: main

This diff changes a few types from being defined as equivalent to a pair
to being discriminated union types with their own function symbol. This
was motivated by an error message (one of many, but the one that broke
the camel's back) about "-" being used in an ambiguous manner. It will
reduce the number of such messages in the future, and will make compiler
data structures easier to inspect in the debugger.

The most important type changed by far is hlds_goal, whose function symbol
is now "hlds_goal". Second and third in importance are llds.instruction
(function symbol "llds_instr") and prog_item.m's item_and_context (function
symbol "item_and_context"). There are some others as well.

In several places, I rearranged predicates to factor the deconstruction of
goals into hlds_goal_expr and hlds_goal_into out of each clause into a single
point. In many places, I changed variable names that used "Goal" to refer
to just hlds_goal_exprs to use "GoalExpr" instead. I also changed variable
names that used "Item" to refer to item_and_contexts to use "ItemAndContext"
instead. This should make reading such code less confusing.

I renamed some function symbols and predicates to avoid ambiguities.

I only made one algorithmic change (at least intentionally).
In assertion.m, comparing two goals for equality now ignores goal_infos
for all kinds of goals, whereas previously it ignored them for most kinds
of goals, but for shorthand goals it was insisting on them being equal.
This seemed to me to be a bug. Pete, can you confirm this?
2007-01-06 09:23:59 +00:00
Zoltan Somogyi
d66ed699a1 Add fields to structures representing the C code itself that says whether
Estimated hours taken: 4
Branches: main

Add fields to structures representing the C code itself that says whether
or not the C code affects the liveness of lvals. This is intended as the basis
for future improvements in the optimization of such code.

Implement a new foreign_proc attribute that allows programmers to set
the value of this field.

Eliminate names referring to `pragma c_code' in the LLDS backend in favor
of names referring to foreign_procs.

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

	Consistently put the field containing C code last in the function
	symbols that contain them.

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

	Rename some other function symbols to avoid ambiguity.

compiler/prog_io_pragma.m:
	Parse the new foreign_proc attribute.

doc/reference_manual.texi:
	Document the new attribute.

compiler/pragma_c_gen.m:
	Rename the main predicates.

compiler/opt_util.m:
	Change some predicates into functions, for more convenient invocation.

compiler/livemap.m:
	Rename the predicates in this module to avoid ambiguity and the need
	for module qualification.

compiler/*.m:
	Conform to the changes above.
2007-01-03 07:20:47 +00:00
Zoltan Somogyi
42bddbeeca This module looks for an optimizes three code patterns, only one
Estimated hours taken: 2
Branches: main

compiler/use_local_vars.m:
	This module looks for an optimizes three code patterns, only one
	of which depends on knowledge of which registers are live at which
	labels. So instead of giving up totally if we cannot compute the
	live register map (due to the presence of foreign language code),
	give up on only the optimization that requires the unavailable
	information.

compiler/basic_block.m:
	Fix grammar in a comment.

compiler/mercury_compile.m:
	Add a missing progress message.
2006-12-27 03:22:27 +00:00
Julien Fischer
b4c3bb1387 Clean up in unused module imports in the Mercury system detected
Estimated hours taken: 3
Branches: main

Clean up in unused module imports in the Mercury system detected
by --warn-unused-imports.

analysis/*.m:
browser/*.m:
deep_profiler/*.m:
compiler/*.m:
library/*.m:
mdbcomp/*.m:
profiler/*.m:
slice/*.m:
	Remove unused module imports.

	Fix some minor departures from our coding standards.

analysis/Mercury.options:
browser/Mercury.options:
deep_profiler/Mercury.options:
compiler/Mercury.options:
library/Mercury.options:
mdbcomp/Mercury.options:
profiler/Mercury.options:
slice/Mercury.options:
	Set --no-warn-unused-imports for those modules that are used as
	packages or otherwise break --warn-unused-imports, e.g. because they
	contain predicates with both foreign and Mercury clauses and some of
	the imports only depend on the latter.
2006-12-01 15:04:40 +00:00
Zoltan Somogyi
e21193c283 Rename a bunch of predicates and function symbols to eliminate
Estimated hours taken: 6
Branches: main

browser/*.m:
compiler/*.m:
	Rename a bunch of predicates and function symbols to eliminate
	ambiguities.

	The only real change is factoring out some common code in the mlds
	and llds code generators, replacing them with single definitions
	in switch_util.m.
2006-10-15 23:26:56 +00:00
Julien Fischer
aeeedd2c13 Standardize formatting of comments at the beginning of modules.
compiler/*.m:
	Standardize formatting of comments at the beginning of modules.
2006-07-31 08:32:11 +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
be5b71861b Convert almost all the compiler modules to use . instead of __ as
Estimated hours taken: 6
Branches: main

compiler/*.m:
	Convert almost all the compiler modules to use . instead of __ as
	the module qualifier.

	In some cases, change the names of predicates and types to make them
	meaningful without the module qualifier. In particular, most of the
	types that used to be referred to with an "mlds__" prefix have been
	changed to have a "mlds_" prefix instead of changing the prefix to
	"mlds.".

	There are no algorithmic changes.
2006-03-17 01:40:46 +00:00
Julien Fischer
45fdb6c451 Use expect/3 in place of require/2 throughout most of the
Estimated hours taken: 4
Branches: main

compiler/*.m:
	Use expect/3 in place of require/2 throughout most of the
	compiler.

	Use unexpected/2 (or sorry/2) in place of error/1 in more
	places.

	Fix more dodgy assertion error messages.

	s/map(prog_var, mer_type)/vartypes/ where the latter is meant.
2005-11-28 04:11:59 +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
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
2dcc936a74 Convert these modules to four-space indentation to reduce the number
Estimated hours taken: 1
Branches: main

compiler/abstract_mode_constraints.m:
compiler/accumulator.m:
compiler/arg_info.m:
compiler/assertion.m:
compiler/atsort.m:
compiler/basic_block.m:
compiler/build_mode_constraints.m:
compiler/call_gen.m:
compiler/clause_to_proc.m:
	Convert these modules to four-space indentation to reduce the number
	of bad line breaks.

	Various minor cleanups.

	There are no algorithmic changes.
2005-08-08 02:57:09 +00:00
Zoltan Somogyi
c08ca7fbc8 Import only one module per line in the modules of the compiler
Estimated hours taken: 3
Branches: main

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

	Misc other cleanups.

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

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

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

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

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

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

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

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

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

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

browser/:
compiler/:
	Many changes to account for movement of types, and the change to
	proc_label.
2005-01-19 03:11:22 +00:00
Zoltan Somogyi
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
5e25af41f7 This diff changes the LLDS backend to make it easier to read and to maintain,
Estimated hours taken: 6
Branches: main

This diff changes the LLDS backend to make it easier to read and to maintain,
but contains no changes in algorithms whatsoever.

compiler/basic_block.m:
compiler/dupelim.m:
compiler/frameopt.m:
compiler/jumpopt.m:
compiler/layout_out.m:
compiler/livemap.m:
compiler/peephole.m:
compiler/reassign.m:
compiler/rtti_out.m:
compiler/use_local_vars.m:
	Convert these modules to our current coding standards. Use state
	variable notation when appropriate, reordering arguments as necessary.

compiler/llds_out.m:
	Convert these modules to our current coding standards. Use state
	variable notation when appropriate, reordering arguments as necessary.

	Delete predicates which are just specialized forms of foldl, using
	foldl (or foldl2 etc) directly instead.

	Factor out some common code.

compiler/livemap.m:
	Convert these modules to our current coding standards. Use state
	variable notation when appropriate, reordering arguments as necessary.

	Remove some special case handling that used to be required by the value
	numbering pass.

library/bintree_set.m:
	Provide a function version of the initialization predicate.
2003-11-11 03:35:13 +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
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
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
Simon Taylor
51732e925d Reverse the order of the arguments of internal labels
Estimated hours taken: 0.25

compiler/llds.m:
compiler/*.m:
	Reverse the order of the arguments of internal labels
	to make comparison more efficient (the proc_labels will
	almost always be equal). This change reduces the time
	taken by `mmc -C make_hlds' by 1-2%.
2000-10-31 02:15:48 +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
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
89065f0a1e Fix a bug in frameopt reported by Serge Varennes on April 15, 1999.
Estimated hours taken: 8

Fix a bug in frameopt reported by Serge Varennes on April 15, 1999.

The bug was that frameopt recognized that a procedure did not need a
stack frame, and deleted the frame setup code, but did not redirect the
failure branches inside inlined model_semi pragma_c instructions,
so that they still led to code that deallocated the (now nonexistent)
stack frame. This meant that calls to this procedure violated the
invariant which says that calls leave MR_sp unchanged.

compiler/llds.m:
	Add a new pragma C component (pragma_c_fail_to) that represents the
	branch to a label on failure of a model_semi piece of C code, instead
	of handling this by generating a string containing the C code that
	branches to this label. Record the failure label as a new field
	in pragma_c instructions.

	The point of this change is that it makes it possible to substitute
	the failure label in frameopt.

	Add also a pragma_c_noop component to make the generated code somewhat
	better optimizable.

compiler/pragma_c_gen.m:
	Generate the new LLDS components.

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

	Move a predicate declaration away from the middle of another predicate.

compiler/frameopt.m:
	Perform substitutions on pragma C code labels that occur only
	in pragma_c_fail_to components.

	If a pragma_c instruction has any other references to labels, we now
	assume that the block containing the instruction needs a stack frame,
	since those labels can't be substituted with their non-teardown
	parallels if this block is moved to a context without a stack frame.

compiler/basic_block.m:
compiler/dupelim.m:
compiler/frameopt.m:
compiler/opt_util.m:
	Both basic_block.m and dupelim.m had code that substantially
	duplicated code in frameopt.m. This change factors out the differences
	among the versions and moves the unified predicates to opt_util.m.

compiler/code_gen.m:
compiler/code_info.m:
compiler/dupelim.m:
compiler/livemap.m:
compiler/llds_common.m:
compiler/middle_rec.m:
compiler/opt_debug.m:
compiler/trace.m:
compiler/value_number.m:
compiler/vn_*.m:
	Trivial updates to conform to the changes in llds.m.

tests/hard_coded/frameopt_pragma_redirect.{m,exp}:
	A new test case that exhibits the problem. (It is not the original
	test cases submitted by Serge Varennes, because that code depended
	on non-standard functions in ieeefp.h.)

tests/hard_coded/Mmakefile:
	Enable the new test case.
1999-11-12 03:47:08 +00:00
Zoltan Somogyi
ed063bcc00 Extend the new failure handling method to optionally preserve an invariant
Estimated hours taken: 30

Extend the new failure handling method to optionally preserve an invariant
required by accurate gc: always being able to tell with respect to what MR_sp
or MR_curfr to interpret the stackvars and framevars referred to by the label
whose address is the redoip slot of a nondet stack frame. This basically
requires limitations on the hijacking of redoip/redofr slot pairs.

compiler/notes/failure.html:
	Describe the new extension.

	Change the terminology to conform to what is used in the code.

compiler/llds.m:
	For each temporary frame on the nondet stack, specify the native
	stack of the procedure that created it. This is so that we know
	whether the temporary frame ought to have the fourth slot that
	specifies the right value of MR_sp. (The fourth slot is included
	only in temporary nondet stack frames created procedures that live
	on the det stack; procedures that live on the nondet stack never
	have any of their variables on the det stack.)

	Remove the modframe llds instruction, since it does not specify
	what frame's redoip slot it is assigning to. This is error-prone
	(see peephole.m below). We were not using modframe much anyway.

compiler/llds_out.m:
compiler/opt_debug.m:
	Emit either mktempframe or mkdettempframe depending on the new
	field in temp_frame.

compiler/code_info.m:
	Add a fourth item to the failure state, which states whether
	the top frame of the nondet stack may be hijacked. Initialize
	it from the option --allow-hijacks. If about to do a hijack
	but the failure state says no, create a temporary frame instead.

	Separate out the code for creating temporary frames, since it
	is now called from more than one place. Generalize the code
	to handle the new type of temp frame.

compiler/code_info.m:
compiler/ite_gen.m:
	Simplify the way we transmit information about the location
	of the address of the nondet stack frame in which the soft cut
	is performed from the start of the condition to its end.

	Remove the predicate code_info__maybe_push_temp_frame;
	its functionality is now achieved in code_info.m by disabling
	and restoring --allow-hijacks around the generation of code
	for the condition. This also allows us to get rid of the code
	that finds out whether the condition can do any hijacking.

compiler/opt_util.m:
	Rename next_modframe as next_assign_to_redoip, and add an additional
	argument that says which frame's redoip we are after.

compiler/peephole.m:
	Use the new argument of opt_util__next_assign_to_redoip to fix a bug
	where a mkframe of a temporary frame (which leaves curfr unchanged)
	that was followed a modframe (which assigns to the redoip of curfr)
	was incorrectly optimized (the assignment to the redoip slot was
	applied to the temporary frame, not the ordinary one).

compiler/*.m:
	Minor changes to accommodate the disappearance of modframe.

runtime/mercury_stacks.h:
	Add macros to support four-word temp frames on the nondet stack.

	Make the macros that access nondet stack frame slots start with MR_,
	while keeping (redefined) macros needed for backward compatibility.

	Remove the modframe macro.

	Fix a dangling reference to PREDNM instead of MR_PREDNM.

runtime/mercury_stack_trace.c:
	Modify the stack tracing code to allow for the new four-word temp
	frames.

	Use the new MR_ prefixed variants of the macros.

runtime/mercury_debug.h:
runtime/mercury_misc.[ch]:
	Remove references to modframe.

tests/general/complex_failure.{m,exp}:
	A new test case to tickle the various ways of handling nested
	disjunctions and if-then-elses in the new code generator.

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

tests/{general,hard_coded}/space.{m,exp}:
	Move this test case from general to hard_coded. Although NU-Prolog
	can execute it, it does not give the same answers as Mercury due to
	a different default ordering and a difference in integer size (26-bit
	integers in NU-Prolog) that changes the behavior of the pseudo
	random-number generator.

tests/hard_coded/cycles2.exp:
	Add the missing .exp file for this existing test case.

tests/hard_coded/Mmakefile:
	Enable the old test cases cycles, cycles2 and space, since
	we now pass them.
1998-07-29 08:57:09 +00:00
Zoltan Somogyi
d1855187e5 Implement new methods of handling failures and the end points of branched
Estimated hours taken: 260

Implement new methods of handling failures and the end points of branched
control structures.

compiler/notes/failure.html:
	Fix an omission about the handling of resume_is_known in if-then-elses.
	(This omission lead to a bug in the implementation.)

	Optimize cuts across multi goals when curfr is known to be equal
	to maxfr.

	Clarify the wording in several places.

compiler/code_info.m:
	Completely rewrite the methods for handling failure.

	Separate the fields of code_info into three classes: those which
	do not change after initialization, those which record state that
	depends on where in the HLDS goal we are, and those which contain
	persistent data such as label and cell counters.

	Rename grab_code_info and slap_code_info as remember_position
	and reset_to_position, and add a wrapper around the remembered
	code_info to make it harder to make mistakes in its use.
	(Only the location-dependent fields of the remembered code_info
	are used, but putting only them into a separate data structure would
	result in more, not less, memory being allocated.)

	Gather the predicates that deal with handling branched control
	structures into a submodule.

	Reorder the declarations and definitions of access predicates
	to conform to the new order of fields.

	Reorder the declarations and definitions of the failure handling
	submodule to better reflect the separation of higher-level and
	lower-level predicates.

compiler/code_gen.m:
	Replace code_gen__generate_{det,semi,non}_goal_2 with a single
	predicate, since for most HLDS constructs the code here is the same
	anyway (the called preds check the code model when needed).

	Move classification of the various kinds of unifications to unify_gen,
	since that is where it belongs.

	Move responsibility for initializing the code generator's trace
	info to code_info.

	Move the generation of code for negations to ite_gen, since the
	handling of negations is a cut-down version of the handling of
	negations. This should make the required double maintenance easier,
	and more likely to happen.

compiler/disj_gen.m:
compiler/ite_gen.m:
	These are the two modules that handle most failures; they have
	undergone a significant rewrite. As part of this rewrite, factor
	out the remaining common code between model_non and model_{det,semi}
	goals.

compiler/unify_gen.m:
	Move classification of the various kinds of unifications here from
	code_gen. This allows us to keep several previously exported
	predicates private.

compiler/call_gen.m:
	Factor out some code that was common to ordinary calls, higher order
	calls and method calls. Move the common code that checks whether
	we are doing tracing to trace.m.

	Replace call_gen__generate_{det,semi,nondet}_builtin with a single
	predicate.

	Delete the commented out call_gen__generate_complicated_unify,
	since it will never be needed and in any case suffered from
	significant code rot.

compiler/llds.m:
	Change the mkframe instruction so that depending on one of its
	arguments, it can create either ordinary frames, or the cut-down
	frames used by the new failure handling algorithm (they have only
	three fixed fields: prevfr, redoip and redofr).

compiler/llds_out.m:
	Emit a #define MR_USE_REDOFR before including mercury_imp.h, to
	tell the runtime we are using the new failure handling scheme.
	This effectively changes the grade of the compiled module.

	Emit MR_stackvar and MR_framevar instead of detstackvar and framevar.
	This is a step towards cleaning up the name-space, and a step towards
	making both start numbering at 0. For the time being, the compiler
	internally still starts counting framevars at 0; the code in llds_out.m
	adds a +1 offset.

compiler/trace.m:
	Change the way trace info is initialized to fit in with the new
	requirements of code_info.m.

	Move the "are we tracing" check from the callers to the implementation
	of trace__prepare_for_call.

compiler/*.m:
	Minor changes in accordance with the major ones above.

compiler/options.m:
	Introduce a new option, allow_hijacks, which is set to "yes" by
	default. It is not used yet, but the idea is that when it is set to no,
	the code generator will not generate code that hijacks the nondet
	stack frame of another procedure invocation; instead, it will create
	a new temporary nondet stack frame. If the current procedure is
	model_non, it will have three fields: prevfr, redoip and redofr.
	If the current procedure is model_det or model_semi, it will have
	a fourth field that is set to the value of MR_sp. The idea is that
	the runtime system, which will be able to distinguish between
	ordinary frames (whose size is at least 5 words), 3-word and 4-word
	temporary frames, will now be able to use the redofr slots of
	all three kinds of frames and the fourth slot values of 4-word
	temporary frames as the addresses relative to which framevars
	and detstackvars respectively ought to be offset in stack layouts.

compiler/handle_options.m:
	Turn off allow_hijacks if the gc method is accurate.

runtime/mercury_stacks.h:
	Change the definitions for the nondet stack handling macros
	to accommodate the new nondet stack handling discipline.
	Define a new macro for creating temp nondet frames.

	Define MR_based_stackvar and MR_based_framevar (both of which start
	numbering slots at 1), and express other references, including
	MR_stackvar and MR_framevar and backward compatible definitions of
	detstackvar and framevar for hand-written C code, in terms of those
	two.

runtime/mercury_stack_trace.[ch]:
	Add a new function to print a dump of the fixed elements nondet stack,
	for debugging my changes. (The dump does not include variable values.)

runtime/mercury_trace_internal.c:
	Add a new undocumented command "D" for dumping the nondet stack
	(users should not know about this command, since the output is
	intelligible only to implementors).

	Add a new command "toggle_echo" that can cause the debugger to echo
	all commands. When the input to the debugger is redirected, this
	echo causes the output of the session to be much more readable.

runtime/mercury_wrapper.c:
	Save the address of the artificial bottom nondet stack frame,
	so that the new function in mercury_stack_trace.c can find out
	where to stop.

runtime/mercury_engine.c:
runtime/mercury_wrapper.c:
	Put MR_STACK_TRACE_THIS_MODULE at the tops of these modules, so that
	the labels they define (e.g. do_fail and global_success) are registered
	in the label table when their module initialization functions are
	called. This is necessary for a meaningful nondet stack dump.

runtime/mercury_grade.h:
	Add a new component to the grade string that specifies whether
	the code was compiled with the old or the new method of handling
	the nondet stack. This is important, because modules compiled
	with different nondet stack handling disciplines are not compatible.
	This component depends on whether MR_USE_REDOFR is defined or not.

runtime/mercury_imp.h:
	If MR_DISABLE_REDOFR is defined, undefine off MR_USE_REDOFR before
	including mercury_grade.h. This is to allow people to continue
	working on un-updated workspaces after this change is installed;
	they should put "EXTRA_CFLAGS = -DMR_DISABLE_REDOFR" into
	Mmake.stage.params. (This way their stage1 will use the new method
	of handling failure, while their stage2 2&3 will use the old one.)

	This change should be undone once all our workspaces have switched
	over to the new failure handling method.

tests/hard_coded/cut_test.{m,exp}:
	A new test case to tickle the various ways of handling cuts in the
	new code generator.

tests/hard_coded/Mmakefile:
	Enable the new test case.
1998-07-20 10:04:02 +00:00
Thomas Conway
a70b59e83c Add a test to find the number of words needed to represent a
configure.in:
        Add a test to find the number of words needed to represent a
        synchronization term.

boehm_gc/gc.h:
        fix a declaration by replacing the args () with (void).
boehm_gc/solaris_pthreads.c:
        add a missing include
        check the return values of pthread calls.

compiler/*.m:
        Add handling for the new HLDS goal type par_conj.
        Add handling for the four new LLDS instructions:
                init_sync_term
                fork
                join_and_terminate
                join_and_continue

compiler/code_info.m:
        add a new alternative for slot_contents - sync_term.

compiler/handle_options.m:
        add .par as part of the grade

compiler/hlds_goal.m:
        add the new goal type par_conj.

compiler/instmap.m:
        add instmap__unify which takes a list of instmaps
                and abstractly unifies them.
        add unify_instmap_delta which tajes two instmap deltas
                and abstractly unifies them.

compiler/llds.m:
        add the new llds instructions.

compiler/mode_info.m:
        add par_conj as a lock reason.

library/Makefile:
        work around a bug in the solaris version pthread.h

library/benchmarking.m:
        reference the stack zones from the engine structure
        rather than from global variables.

library/{nc,sp}_builtin.nl:
        add an op declaration for &.

library/std_util.m:
        change references to global variables to references inside
        the engine structure.

runtime/Mmakefile:
        add mercury_thread.{c,h}
        add THREADLIBS to the libraries

runtime/*.{c,h}
        Remove some old junk from the previous processes/shrd-mem
        changes that found their way into the repository.
        Add MR_ prefixes to lots of names.

runtime/mercury_context.c:
        Add init_thread_stuff for creating and initializing a
        context structure for the current thread.

runtime/mercury_context.h:
        add a field to the mercury context which stores the thread id
        of the thread where this context originated.
        add various macros for implementing the new llds instructions.

runtime/mercury_engine.c:
        initialize the engine structure, rather than a bunch of globals.

runtime/mercury_engine.h:
        declare the mercury_engine structure.

runtime/mercury_regorder.h:
        if MR_THREAD_SAFE, and there is at least one global register
        then use mr0 as a pointer to the mercury engine structure.

scripts/init_grade_options.sh-subr
        add thread_safe

scripts/mgnuc.in
        add THREAD_OPTS

scripts/ml.in:
        add THREAD_LIBS
1998-06-09 02:16:31 +00:00
Zoltan Somogyi
d10af74168 This change introduces interface tracing, and makes it possible to successfully
Estimated hours taken: 50

This change introduces interface tracing, and makes it possible to successfully
bootstrap the compiler with tracing (either interface or full).

compiler/options.m:
	Change the bool options --generate-trace into a string option --trace
	with three valid values: minimal, interface and full. The last two mean
	what they say; the intention is that eventually minimal will mean
	no tracing in non-tracing grades and interface tracing in tracing
	grades.

compiler/globals.m:
	Add a new global for the trace level.

compiler/handle_options.m:
	Convert the argument of --trace to a trace level.

	Use only consistent 4-space indentation in the deeply nested
	if-then-else.

compiler/trace.m:
	Implement interface tracing.

	Rename trace__generate_depth_reset_code as trace__prepare_for_call,
	since it does more than reset the depth if this module is compiled
	with interface tracing.

	Do not check whether tracing is enabled before calling MR_trace;
	let MR_trace make the check. This trades increased non-tracing
	execution time for a substantial code size reduction (which may
	in turn benefit execution time).

compiler/call_gen.m:
	Call trace__generate_depth_reset_code by its new name.

compiler/code_info.m:
	Fix a bug in the handling of non/semi commits. When entering a commit,
	we used to push a clone of whatever the top failure continuation was.
	However, the resume setup for this continuation could have started
	with a label that assumed that the resume vars were in their original
	locations (which are often registers), whereas the method of
	backtracking to that point only guarantees the survival of stack slots,
	not registers.

	(This bug caused two lines of incorrect code to be generated among
	the approx 30 million lines of code in the stage 2 compiler when
	compiled with tracing.)

	Fix another bug (previously untriggered as far as I know) in the
	handling of multi/det commits. This one was breaking the invariant
	that the resume vars set of each entry on the failure continuation
	stack included the resume vars set of every other entry below it,
	which meant that the values of these resume vars were not guaranteed
	to be preserved.

compiler/stack_layout.m:
	Make layout structures local to their module. They are not (yet)
	referred to by name from other modules, and by declaring them
	to be global we caused their names to be included even in stripped
	executables, adding several megabytes to the size of the binary.
	(The names are not stripped because a dynamically linked library
	may want to refer to them.)

	Change the mercury_data__stack_layout__ prefix on the names of
	generated globals vars to just mercury_data__layout__. It is now
	merely too long instead of far too long.

	Include the label number in the label layout structure and the number
	of typeinfo variables in a var_info structure only with native gc.
	Their only use is in debugging native gc.

	Fix some documentation rot.

compiler/llds.m:
	Add a new field to the pragma_c instruction that says whether the
	compiler-generated C code fragments access any stack variables.

compiler/frameopt.m:
	Use the new field in pragma_c's to avoid a bug. Because frameopt was
	assuming that the pragma_c instruction that filled in the stack slots
	containing the call sequence number and depth did not access the stack,
	it moved the pragma_c before the incr_sp that allocates the frame
	(it was trying to get it out of the loop).

compiler/*.m:
	Minor changes to set or ignore the extra field in pragma_c, to refer
	to layout structures via the new prefix, or to handle the --trace
	option.

doc/user_guide.texi:
	Update the documentation for --trace.

runtime/mercury_types.h:
	Add the type Unsigned.

runtime/mercury_goto.h:
	Use the shorter layout prefix.

runtime/mercury_stack_layout.h:
	Use the shorter layout prefix, and include the label number only with
	native gc.

runtime/mercury_trace.[ch]:
runtime/mercury_trace_internal.[ch]:
runtime/mercury_trace_external.[ch]:
runtime/mercury_trace_util.[ch]:
	Divide the old mercury_trace.[ch] into several components, with one
	module for the internal debugger, one for the interface to the
	external debugger, one for utilities needed by both. Mercury_trace.c
	now has only the top-level stuff that steers between the two
	debuggers.

runtime/mercury_trace.[ch]:
	Add the new global variable MR_trace_from_full. Before each call,
	the calling procedure assigns TRUE to this variable if the caller
	is fully traced, and FALSE otherwise. Interface traced procedures
	generate trace events only if this variable is TRUE when they are
	called (fully traced callee procedures ignore the initial value of
	the variable).

	Make MR_trace return immediately without doing anything unless
	tracing is enabled and a new extra argument to MR_trace is TRUE.
	This extra argument is always TRUE for trace events in fully traced
	procedures, while for trace events from interface traced procedures,
	its value is set from the value of MR_trace_from_full at the time
	that the procedure was called (i.e. the event is ignored unless the
	interface traced procedure was called from a fully traced procedure).

runtime/mercury_trace.[ch]:
runtime/mercury_trace_internal.[ch]:
	For global variables that are stored in stack slots, make their type
	Word rather than int.

	Use a new function MR_trace_event_report instead of calling
	MR_trace_event with a NULL command structure pointer to indicate
	that the event is to be reported but there is to be no user
	interaction.

	Use %ld formats in printfs and casts to long for better portability.

runtime/mercury_trace_internal.c:
	Save trace-related globals across calls to Mercury library code
	in the debugger, since otherwise any trace events in this code
	could screw up e.g. the event number or the call number sequence.

	Create separate functions for printing port names and determinisms.

runtime/mercury_wrapper.h:
	Disable the tracing of the initialization and finalization code
	written in Mercury.

runtime/Mmakefile:
	Update for the new source and header files.

tests/debugger/{debugger_regs,interpreter,queens}_lib.{m,inp,exp}:
	One new copy of each existing test case. These ones are intended
	to be used when the stage 2 library is compiled with tracing, which
	affects the tests by adding events for the library procedures called
	from the test programs.

	The .m files are the same as before; one of the .inp files is a bit
	different; the .exp files reflect the correct output when the library
	is compiled with full tracing.

tests/debugger/Mmakefile:
	Provide separate targets for the new set of test cases.

	Use --trace full instead of --generate-trace.

tests/debugger/runtests:
	Try both the new set of test cases if the old set fails, and report
	failure only if both sets fail. This is simpler than trying to figure
	out which set should be really tested, and the probability of a false
	positive is negligible.
1998-05-16 07:31:33 +00:00
Zoltan Somogyi
5013dd9c76 Implement nondet pragma C codes.
Estimated hours taken: 40

Implement nondet pragma C codes.

runtime/mercury_stacks.h:
	Define a new macro, mkpragmaframe, for use in the implementation
	of nondet pragma C codes. This new macro includes space for a
	struct with a given sruct tag in the nondet stack frame being created.

compiler/{prog_data.m,hlds_goal.m}:
	Revise the representation of pragma C codes, both as the item and
	in the HLDS.

compiler/prog_io_pragma.m:
	Parse nondet pragma C declarations.

	Fix the indentation in some places.

compiler/llds.m:
	Include an extra argument in mkframe instructions. This extra argument
	gives the details of the C structure (if any) to be included in the
	nondet stack frame to be created.

	Generalize the LLDS representation of pragma C codes. Instead of a
	fixed sequence of <assign from inputs, user c code, assign to outputs>,
	let the sequence contain these elements, as well as arbitrary
	compiler-generated C code, in any order and possibly with repetitions.
	This flexibility is needed for nondet pragma C codes.

	Add a field to pragma C codes to say whether they can call Mercury.
	Some optimizations can do a better job if they know that a pragma C
	code cannot call Mercury.

	Add another field to pragma C codes to give the name of the label
	they refer to (if any). This is needed to prevent labelopt from
	incorrectly optimizing away the label definition.

	Add a new alternative to the type pragma_c_decl, to describe the
	declaration of the local variable that points to the save struct.

compiler/llds_out.m:
	Output mkframe instructions that specify a struct as invoking the new
	mkpragmaframe macro, and make sure that the struct is declared just
	before the procedure that uses it.

	Other minor changes to keep up with the changes to the representation
	of pragma C code in the LLDS, and to make the output look a bit nicer.

compiler/pragma_c_gen.m:
	Add code to generate code for nondet pragma C codes. Revise the utility
	predicates and their data structures a bit to make this possible.

compiler/code_gen.m:
	Add code for the necessary special handling of prologs and epilogs
	of procedures defined by nondet pragma C codes. The prologs need
	to be modified to include a programmer-defined C structure in the
	nondet stack frame and to communicate the location of this structure
	to the pragma C code, whereas the functionality of the epilog is
	taken care of by the pragma C code itself.

compiler/make_hlds.m:
	When creating a proc_info for a procedure defined by a pragma C code,
	we used to insert unifications between the headvars and the vars of
	the pragma C code into the body goal. We now perform substitutions
	instead. This removes a factor that would complicate the generation
	of code for nondet pragma C codes.

	Pass a moduleinfo down the procedures that warn about singletons
	(and other basic scope errors). When checking whether to warn about
	an argument of a pragma C code not being mentioned in the C code
	fragment, we need to know whether the argument is input or output,
	since input variables should appear in some code fragments in a
	nondet pragma C code and must not appear in others. The
	mode_is_{in,out}put checks need the moduleinfo.

	(We do not need to check for any variables being mentioned where
	they shouldn't be. The C compiler will fail in the presence of any
	errors of that type, and since those variables could be referred
	to via macros whose definitions we do not see, we couldn't implement
	a reliable test anyway.)

compiler/opt_util.m:
	Recognize that some sorts of pragma_c codes cannot affect the data
	structures that control backtracking. This allows peepholing to
	do a better job on code sequences produced for nondet pragma C codes.

	Recognize that the C code strings inside some pragma_c codes refer to
	other labels in the procedure. This prevents labelopt from incorrectly
	optimizing away these labels.

compiler/dupelim.m:
	If a label is referred to from within a C code string, then do not
	attempt to optimize it away.

compiler/det_analysis.m:
	Remove a now incorrect part of an error message.

compiler/*.m:
	Minor changes to conform to changes to the HLDS and LLDS data
	structures.
1998-01-13 10:14:23 +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