Estimated hours taken: 1
Another fix to make `any' insts work better.
det_util.m, constraint.m:
Change the way we check for no_output_vars so that it takes
into account non-local variables that are not in the instmap
delta, because a non-local variable whose initial and final
insts are both `any' will not be recorded in the instmap delta,
yet it may get further instantiated by the goal.
Estimated hours taken: 45
Module qualification of types, insts and modes.
Added a new interface file - <module>.int3. This contains the
short interface qualified as much as possible given the information
in the current module.
When producing the .int and .int2 files for a module, the compiler uses
the information in the .int3 files of modules imported in the interface
to fully module qualify all items. The .int2 file is just a fully
qualified version of the .int3 file. The .int3 file cannot be overwritten
by the fully qualified version in the .int2 file because then mmake would
not be able to tell when the interface files that depend on that .int3
file really need updating.
The --warn-interface-imports option can be used to check whether
a module imported in the interface really needs to be imported in
the interface.
compiler/module_qual.m
Module qualify all types, insts and modes. Also checks for modules
imported in the interface of a module that do not need to be.
compiler/modules.m
The .int file for a module now depends on the .int3 files of imported
modules. Added code to generate the make rule for the .int file in the
.d file. There is now a file .date2 which records the last time the
.int2 file was updated.
The .int3 files are made using the --make-short-interface option
introduced a few weeks ago.
compiler/options.m
Added option --warn-interface-imports to enable warning about interface
imports which need not be in the interface. This is off by default
because a lot of modules in the library import list.m when they only
need the type list, which is defined in mercury_builtin.m.
Removed option --builtin-module, since the mercury_builtin name is wired
into the compiler in a large number of places.
compiler/prog_util.m
Added a predicates construct_qualified_term/3 and construct_qualfied_term/4
which take a sym_name, a list of argument term and a context for the /4
version and give a :/2 term.
compiler/type_util.m
Modified type_to_type_id to handle qualified types. Also added predicates
construct_type/3 and construct_type/4 which take a sym_name and a list of
types and return a type by calling prog_util:construct_qualified_term.
compiler/modes.m
On the first iteration of mode analysis, module qualify the modes of
lambda expressions.
compiler/mode_info.m
Added field to mode_info used to decide whether or not to module qualify
lambda expressions.
compiler/mode_errors.m
Added dummy mode error for when module qualification fails so that mode
analysis will stop.
Added code to strip mercury_builtin qualifiers from error messages to
improve readability.
compiler/typecheck.m
Strip builtin qualifiers from error messages.
compiler/llds.m
compiler/llds_out.m
compiler/opt_util.m
compiler/opt_debug.m
Change the format of labels produced for the predicates to use the
qualified version of the type name.
compiler/mercury_compile.pp
Call module_qual__module_qualify_items and make_short_interface.
Remove references to undef_modes.m and undef_types.m
compiler/undef_modes.m
compiler/undef_types.m
Removed, since their functionality is now in module_qual.m.
compiler/prog_io.m
Changed to qualify the subjects of type, mode and inst declarations.
compiler/*.m
Changes to stop various parts of the compiler from throwing away
module qualifiers.
Qualified various mercury_builtin builtins, e.g. in, out, term etc.
where they are wired in to the compiler.
compiler/hlds_data.m
The mode_table and user_inst_table are now abstract types each
storing the {mode | inst}_id to hlds__{mode | inst}_defn maps
and a list of mode_ids or inst_ids. This was done to improve the
efficiency of module qualifying the modes of lambda expressions
during mode analysis.
module_info_optimize/2 now sorts the lists of ids.
The hlds_module interface to the mode and inst tables has not changed.
compiler/hlds_module.m
Added yet another predicate to search the predicate table.
predicate_table_search_pf_sym_arity searches for predicates or
functions matching the given sym_name, arity and pred_or_func.
compiler/higher_order.m
Changed calls to solutions/2 to list__filter/3. Eliminated unnecessary
requantification of goals.
compiler/unused_args.m
Improved abstraction slightly.
Estimated hours taken: 4
Implement `recursive' and `non_recursive' pragma c_code declarations.
This allows the compiler to optimize cases when the C code
is known to not call Mercury code. It's also necessary
to allow C code which modifies the hp register to work
(such code must be declared `non_recursive', otherwise
the registers will be saved and restored over it).
To make things bootstrap OK, the old pragma c_code declarations
default to `non_recursive'.
prog_data.m, hlds_goal.m:
Add new field c_is_recursive to pragma c_code goals.
prog_io.m:
Parse the new `recursive' and `non_recursive' pragma c_code
declarations.
make_hlds.m:
Pass the c_is_recursive field from the parse tree to the HLDS.
live_vars.m:
For non-recursive C code, don't save variables on the stack.
code_gen.pp:
For non-recursive C code, don't save variables on the stack,
don't mark the succip as needing to be saved, and don't
call save_registers() and restore_registers().
*.m:
Change c_code/5 to c_code/6.
Estimated hours taken: 24
Treat higher-order predicate calls as a new sort of goal,
rather than as calls to the special predicate call/N, in order to
remove the fixed limit on the number of arguments and on the modes
for call/N.
Also, remove the restriction on output arguments preceding input arguments
in lambda expressions.
hlds_goal.m:
Add new functor higher_order_call/6 to the hlds__goal type.
*.m:
Handle new functor higher_order_call/6.
arg_info.m:
Abstract things a bit more: the argument passing convention
for a procedure may be affected by that procedure's types,
modes, and code_model, as well as the arg_method.
follow_vars.m:
Pass down the args_method, since it is now needed for figuring
out the arg_info for unifications and higher-order calls.
follow_code.m:
Treat complicated unifications in the same way as calls.
lambda.m:
When creating lambda predicates, permute the arguments so
that all input arguments come before all output arguments.
call_gen.m:
When generating higher-order predicate calls, don't abort
if outputs precede inputs; instead, generate code assuming
that the called predicate's args have been permuted so that
the inputs to come before all the outputs.
Estimated hours taken: 8
options.m:
Rename branch_delay_slot to have_delay_slot.
Set optimize_delay_slot in -O2 only if have_delay_slot was set earlier.
This is possible now because the default optimization level is now
set in mc.
mercury_compile:
Change verbose output a bit to be more consistent.
dead_proc_elim:
Export the predicates that will eventually be needed by inlining.m.
inlining.m:
Use the information about the number of times each procedure is called
to inline local nonrecursive procedures that are called exactly once.
EXCEPT that this is turned off at the moment, since the inlining of
parse_dcg_goal_2 in prog_io, which this change enables, causes the
compiler to emit incorrect code.
prog_io:
Moved the data type definitions to prog_data. (Even though prog_io.m
is ten times the size of prog_data.m, the sizes of the .c files are
not too dissimilar.)
Estimated hours taken: 3
options:
Add a new option, --branch-delay-slot, intended for use by mc on
the basis of the configuattion script. It says whether the machine
architecture has delays slots on branches.
The setting of option should affect whether we set
--optimize-delay-slots at -O2, but this doesn't work yet.
hlds_goal:
Add an extra field to hold follow_vars infromation to disjunctions,
switches and if-then-elses. I intend to use this information to
generate better code.
*.m:
Changes to accommodate the extra field.
Estimated hours taken: 10
hlds, hlds_module, hlds_pred, hlds_goal, hlds_data:
Divided the old hlds.m into four files:
hlds_module.m defines the data structures that deal with issues
that are wider than a single predicate. These data structures are
the module_info structure, dependency_info, the predicate table
and the shape table.
hlds_pred.m defined pred_info and proc_info, pred_id and proc_id.
hlds_goal.m defines hlds__goal, hlds__goal_{expr,info}, and the
other parts of goal structures.
hlsd_data.m defines the HLDS types that deal with issues related
to data and its representation: function symbols, types, insts, modes.
It also defines the types related to determinism.
hlds.m is now an empty module. I have not removed it from CVS
because we may need the name hlds.m again, and CVS does not like
the reuse of a name once removed.
other modules:
Import the necessary part of hlds.
det_analysis:
Define a type that was up to now improperly defined in hlds.m.
prog_io:
Move the definition of type determinism to hlds_data. This decision
may need to be revisited when prog_io is broken up.
dnf, lambda:
Simplify the task of defining predicates.
llds:
Fix some comments.
mercury_compile:
If the option -d all is given, dump all HLDS stages.
shape, unused_args:
Fix formatting.
Estimated hours taken: 12
Implement functional syntax. You can now use `:- func' in a similar manner
to `:- pred'. For example, `:- func foo(int, int) = int.' declares a function,
and `:- mode foo(in, in) = out.' defines a mode for it. You can write clauses
for functions, such as `foo(X, Y) = Z :- Z is 2*X + Y.' Any term in the
head or body of a clause can be a function call, e.g. `bar(X, Y, foo(X, Y))'.
Until we have implemented a proper Mercury debugger, this syntax
should not be used (except that I might reimplement the functions
provided by Prolog's is/2 predicate using this syntax, rather than
the current special-case hack in the parser).
prog_io.m:
Add syntax for declaring and defining functions.
Disallow the use of `=' to define modes, as in `:- mode foo = bar.'
(Instead, you should use `::'. `==' is also allowed.)
Also, use higher-order predicates to simplify some of the rather
repetitious parsing code.
mercury_to_mercury.m, mercury_to_goedel.m, make_hlds.m, modules.m:
Handle new functional syntax.
typecheck.m:
Add support for functions, function types such as `func(int) = int',
and currying. (But there's currently no equivalent to call/N for
functions, so function types and currying aren't very useful yet.)
undef_types.m:
Add support for function types.
modes.m:
Convert function calls into predicate calls.
(This must be done after typechecking is complete,
so I put it in mode analysis.)
hlds.m:
Add new field `pred_or_func' to the pred_info.
hlds_out.m:
Print out the `pred_or_func' field.
higher_order.m, unused_args.m, lambda.m, dnf.m:
Pass extra pred_or_func argument to pred_info_init to specify that
the thing being created is a predicate, not a function.
constraint.m, dependency_graph.m, hlds_out.m:
`mercury_output_mode_subdecl' has been renamed
`mercury_output_pred_mode_subdecl'.
prog_util.m:
Add new predicate split_type_and_mode/3.
llds.m:
Print out
/* code for predicate '*'/3 in mode 0 */
rather than
/* code for predicate */3 in mode 0 */
to avoid a syntax error in the generated C code.
Estimated hours taken: 8
mercury_compile:
Fix the pass structure, and start using a loose sequence of stage
numbers, to make it easier to add new stages without having to fiddle
stage numbers.
THIS DOES MEAN THAT ALL STAGE NUMBERS HAVE CHANGED NOW.
The stage number assignment scheme assigns 1 to 25 to the front end,
26 to 50 to the middle passes, and 51 to 99 to the back end.
hlds:
We had two types that combined a pred_id and a proc_id. One,
pred_proc_id, used a simple pair; the other, procedure_id, had a better
definition using a specific function symbol but was not used
anywhere else. I standardized on the name pred_proc_id, but using the
definition with a dedicated function symbol (proc).
I also defined a type pred_proc_list as a list of pred_proc_id.
To prepare for memoing, I added a new field to pred_info, which is
a list of markers, each requesting a specific transformation on the
predicate or indicating that the transformation has been done.
The inline request is now represented using such a marker. However,
the interface is backwards compatible.
constraint, dead_proc_elim, dependency_graph, det_analysis, det_report,
higher_order, unused_args:
Changes to conform to the new definition of pred_proc_id.
In two places removed definitions of predproclist, whose
equivalent pred_proc_list is now defined in hlds.m.
hlds_out, make_hlds, mercury_to_mercury, prog_io:
Add code to handle memo pragma declarations, using whenever possible
a version of the existing code for handling inline requests, but
generalized for handling any pragma that sets a marker.
switch_detection:
Rename the type cases_list to sorted_cases_list. This avoids a
name clash that creates a duplicate label and therefore screws up
the profiler, and is a better name anyway.
options:
Add a new option, --opt-space, that turns on optimizations that save
space and turns off optimizations that squander space.
handle_options:
Pass the special option handler to getopt.
frameopt:
For each labelled code sequence that tears down the stack frame but
does not use it, we used to create a parallel code sequence that omits
the teardown code, for use by gotos from locations that did not have
a stack frame. However, peepholing may discover that it is better
not to tear down the stack frame at the site of the goto after all,
so we need the original code sequence as well.
The current change fixes a bug that occurs if the original code
sequence is modified by another part of frameopt to omit teardown
code. In such cases, which are produced by --pred-value-number,
peepholing redirects a goto to a code sequence that it thinks tears
down the stack frame, but actually doesn't.
With this change, --pred-value-number now works.
llds:
Fix typos in a comment.
Estimated hours taken: 6
arg_info:
Add support for the compact argument passing convention. The proper
handling of higher order calls etc is still missing.
globals:
Added a third global type, args_method, current either "old" or
"compact".
passes_aux:
Moved some auxiliary predicates from mercury_compile and options
to passes_aux.
constraint, det_analysis, make_hlds, modules, optimize, undef_types:
Import and refer to passes_aux.
mercury_compile, handle_options:
Remove the predicates moved to passes_aux. Also move the option
postprocessing code to a new module, handle_options.
Another change is that we stop after syntax errors if the new option
--halt-at-syntax-errors is set.
handle_option:
New module for option postprocessing.
options:
Remove the option lookup predicates, which were obsolete.
Add new options --args, --halt-at-syntax-errors and --opt-level.
Add a special handler for --opt-level.
lookup_switch:
Call getopt to look up options, not options.
value_number, vn_block:
Extended basic blocks with more than one incr_hp pose a problem for
value numbering when using boehm_gc, because value numbering coalesces
all the allocations into one. Previously we did not optimize such
sequences. I modified value numbering to divide up such blocks into
smaller blocks, each with at most one incr_hp, and optimize these.
At the moment, some of these blocks contain deeply nested field
refs, which value numbering is very slow to handle; code_exprn
should be modified to fix these.
value_number:
Rename usemap to useset, since this is more accurate.
Fixed a bug in --pred-value-number, which manifested itself as
the generation of duplicate labels.
labelopt:
Rename usemap to useset, since this is more accurate.
Estimated hours taken: 1.5
Undo dylan's changes in the names of some library entities,
by applying the following sed script
s/term_atom/term__atom/g
s/term_string/term__string/g
s/term_integer/term__integer/g
s/term_float/term__float/g
s/term_context/term__context/g
s/term_functor/term__functor/g
s/term_variable/term__variable/g
s/_term__/_term_/g
s/std_util__bool_/bool__/g
to all the `.m' and `.pp' files in the compiler and library directories.
The reason for undoing these changes was to minimize incompatibilities
with 0.4 (and besides, the changes were not a really good idea in the first
place).
I also moved `bool' to a separate module.
The main reason for that change is to ensure that the `__' prefix is
only used when it genuinely represents a module qualifier.
(That's what dylan's changes were trying to acheive, but `term__'
does genuinely represent a module qualifier.)
compiler/*.m:
Apply sed script above;
where appropriate, add `bool' to the list of imported modules.
Estimated hours taken: 0.25
Fix new warnings detected by the latest version of the compiler.
constraint.m, mercury_to_mercury.m, mercury_to_goedel.m:
Eliminate `condition in if-then-else cannot fail' warnings.
Estimated hours taken: _2___
Change names with badly placed double underscores (ie where the part of
a name before a double underscore is not the same as the module name.)
Reflect changes in the library interface.
compiler/*:
Use the newer, more correct form of the term and bool names.
Predicates "bool__" are now "std_util__bool" and labels of
the term ADT are now "term_" instead of "term__".
compiler/vn*.m:
change all names "vn__*" to a correct module prefix. All the
names remain qualified.
compiler/hlds.m:
s/\<is_builtin__/hlds__is_builtin_/g
s/\<dependency_info__/hlds__dependency_info_/g
compiler/unify_proc.m:
s/\<unify_proc_info__/unify_proc__info_/g
compiler/transform.m:
s/\<reschedule__conj/transform__reschedule_conj/g
excess:
A new pass to remove unnecessary assignment unifications.
mercury_compile:
Call the new excess assignment module.
options:
Add a new option, excess_assign, to control the new optimization.
Add another, num-real-regs, to specify how many of r1, r2 etc are
actually real registers. The default is now set to 5 for kryten;
later it should be supplied by the mc script, with a value determined
at configuration time.
tag_switch:
Use num-real-regs to figure out whether it is likely to be worthwhile
to eliminate the common subexpression of taking the primary tag of
a variable. Also fix an old performance bug: the test for when a
jump table is worthwhile was reversed.
value_number, vn_block:
Do value numbering on extended basic blocks, not basic blocks.
vn_debug:
Modify an information message.
labelopt:
Clean up an export an internal predicate for value numbering. Replace
bintree_set with set.
middle_rec:
Prepare for the generalization of middle recursion optimization
to include predicates with an if-then-else structure.
cse_detection:
Fix a bug: when hoisting a common desconstruction X = f(Yi), create
new variables for the Yi. This avoids problems with any of the Yis
appearing in other branches of the code.
goal_util:
Add a new predicate for use by cse_detection.
common:
Fix a bug: recompute instmap deltas, since they may be affected by the
optimization of common structures.
code_info:
Make an error message more explicit.
det_analysis:
Restrict import list to the needed modules.
*.m:
Import assoc_list.
inst_match.m:
Add new predicate `inst_matches_binding'.
This is like `inst_matches_final', except that it ignores
differences in uniqueness.
modes.m, det_report.m, constraint.m:
Use `inst_matches_binding' rather than `inst_matches_final'
when testing whether a goal has no output variables.
This avoids some problems with unique modes.
The changes made allow declarations of the form:
:- pragma(c_code, predname(Varname1::mode1, Varname2::mode2, ...),
"Some C code to execute instead of a mercury clause;").
There are still a couple of minor problems to be fixed in the near future:
If there is a regular clause given as well as a pragma(c_code, ...) dec, it
is not handled well, and variables names '_' are not handled well.
prog_io.m:
parse the pragma(c_code, ...) dec.
hlds.m:
define a new hlds__goal_expr 'pragma_c_code'.
make_hlds.m:
insert the pragma(c_code, ...) dec. as a pragma_c_code into the hlds.
det_analysis.m:
infer that pragma_c_code goals are det.
modes.m:
convince the mode checker that the correct pragma variables are bound
etc.
quantification.m:
quantify the variables in the pragma(c_code, ...) dec.
code_gen.pp:
convert pragma_c_code into pragma_c (in the llds).
llds.m:
define a new instr, pragma_c. Output the pragma_c
hlds_out.m:
mercury_to_mercury.m:
mercury_to_goedel.m:
spit out pragma(c_code, ...) decs properly
*.m: handle the new pragma_c_code in the hlds or the new pragma_c in the llds
modes.m, unify_proc.m:
Fix obscure "map_lookup failed" bug triggered by a partially
instantiated mode of a complicated unification predicate, whose
procedure body contained a call the the same complicated
unification predicate in a different partially instantiated
mode.
constraint.m, cse_detection.m:
Change calls to modecheck to match new simplified interface.
context of the unification from which call was made. We we use this to generate
significantly better error messages. (There should be no more messages of the
form "call to __Unify__(blah blah blah) can fail".) Most of the files are
changed just to reflect this.
An unrelated change in det_analysis is that we now ensure the absence of
cycles by modifying the new inferred determinism in the light of the old
one, ensuring that any changes are monotonic.
In hlds_out, inhibit the printing of pseudo-imported predicates (unifications)
since nobody cares about them except sometimes Fergus.
unifications. See the comments at the top of unify_proc.m for
details of how it's done.
hlds.m:
Add new export statuses `pseudo_imported' and `pseudo_exported'
to handle unification predicates, which can now have complicated
modes.
code_gen.pp, code_info.m, common.m, constraint.m, cse_detection.m,
follow_code.m, follow_vars.m, hlds_out.m, inlining.m, live_vars,
make_hlds.m, mercury_compile.pp, modes.m, store_alloc.m,
switch_detection.m:
Handle pseudo_imported predicates.
modes.m, constraint.m:
Change modecheck to return an updated module_info, since
modechecking may insert new entries into the unify_requests
queue in the module_info. Make sure that modechecking
never inserts requests into the unify_requests queue
for code that has mode errors (or needs rescheduling).
call_gen.m, polymorphism.m:
Move duplicated code into unify_proc.m.
clause_to_proc.m:
Add new predicate clauses_to_proc for use by unify_proc.m.
unify_proc.m:
Implement complicated unifications with complicated modes.
