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88 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Zoltan Somogyi
|
df229e6237 |
Don't pass an unused variable.
compiler/var_locn.m:
Many predicates in var_locn.m took a code_info argument that they
seemed to use, but it turned out that *all* they used this argument for
is to pass them to each other. Delete the unneeded code_info arguments.
compiler/call_gen.m:
compiler/closure_gen.m:
compiler/code_loc_dep.m:
compiler/dense_switch.m:
compiler/disj_gen.m:
compiler/ite_gen.m:
compiler/lookup_switch.m:
compiler/lookup_util.m:
compiler/middle_rec.m:
compiler/par_conj_gen.m:
compiler/pragma_c_gen.m:
compiler/proc_gen.m:
compiler/string_switch.m:
compiler/switch_case.m:
compiler/switch_gen.m:
compiler/trace_gen.m:
compiler/unify_gen.m:
compiler/unify_gen_construct.m:
compiler/unify_gen_deconstruct.m:
Don't pass the unneeded code_info arguments. In predicates that
as a result of this don't need a code_info argument anymore,
delete their code_info arguments as well, and recurse.
Disambiguate empty as cord.empty in the places where the error messages
about too many arguments also mentioned such ambiguity.
In code_loc_dep.m, add more detail to debugging output.
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||
|
Zoltan Somogyi
|
b06b2621b3 |
Move towards packing args with secondary tags.
compiler/hlds_data.m:
Add bespoke types to record information about local and remote secondary
tags. The one for local secondary tags includes the value of the
primary and secondary tag together, since construct unifications
need to assign this value, and it is better to compute this once,
instead leaving the target language compiler to do it, potentially
many times.
Use a wrapped uint8 to record primary tag values, and wrapped uints
to record secondary tag values. The wrap is to prevent any accidental
confusion with other values. The use of uint8 and uint has two purposes.
First, using the tighest possible representation. Tags are never negative,
and primary tags cannot exceed 7. Second, using these types in the compiler
help us eat our own dogfood; if a change causes a problem affecting
these types, its bootcheck should fail, alerting us to the problem.
Add commented-out types and fields that will be needed for packing
sub-word-sized arguments together with both local and remote secondary
tags.
compiler/du_type_layout.m:
Generate references to tags in the new format.
compiler/ml_unify_gen.m:
compiler/unify_gen.m:
compiler/modecheck_goal.m:
Conform to the changes above.
Fix an old bug: the inst corresponding to a constant with a primary
and a local secondary tag is not the secondary tag alone, but both tags
together.
compiler/bytecode.m:
compiler/bytecode_gen.m:
compiler/closure_gen.m:
compiler/disj_gen.m:
compiler/export.m:
compiler/hlds_code_util.m:
compiler/jumpopt.m:
compiler/lco.m:
compiler/llds_out_data.m:
compiler/llds_out_instr.m:
compiler/lookup_switch.m:
compiler/lookup_util.m:
compiler/ml_accurate_gc.m:
compiler/ml_call_gen.m:
compiler/ml_closure_gen.m:
compiler/ml_code_util.m:
compiler/ml_elim_nested.m:
compiler/ml_string_switch.m:
compiler/ml_switch_gen.m:
compiler/ml_tag_switch.m:
compiler/ml_type_gen.m:
compiler/mlds_dump.m:
compiler/mlds_to_c_data.m:
compiler/mlds_to_c_stmt.m:
compiler/opt_debug.m:
compiler/peephole.m:
compiler/rtti.m:
compiler/rtti_out.m:
compiler/rtti_to_mlds.m:
compiler/string_switch.m:
compiler/switch_util.m:
compiler/tag_switch.m:
compiler/type_ctor_info.m:
Conform to the change to hlds_data.m.
In two places, in rtti_out.m and rtti_to_mlds.m, delete old code
that was needed only to implement reserved tags, which we have
stopped supporting a few months ago.
library/uint8.m:
library/uint16.m:
library/uint32.m:
library/uint64.m:
Add predicates to cast from each of these types to uint.
|
||
|
Zoltan Somogyi
|
15aa457e12 | Delete $module arg from calls to unexpected. | ||
|
Julien Fischer
|
8a240ba3f0 |
Add builtin 8, 16 and 32 bit integer types -- Part 1.
Add the new builtin types: int8, uint8, int16, uint16, int32 and uint32.
Support for these new types will need to be bootstrapped over several changes.
This is the first such change and does the following:
- Extends the compiler to recognise 'int8', 'uint8', 'int16', 'uint16', 'int32'
and 'uint32' as builtin types.
- Extends the set of builtin arithmetic, bitwise and relational operators to
cover the new types.
- Extends all of the code generators to handle new types. There currently lots
of limitations and placeholders marked by 'XXX FIXED SIZE INT'. These will
be lifted in later changes.
- Extends the runtimes to support the new types.
- Adds new modules to the standard library intended to hold the basic
operations on the new types. (These are currently empty and not documented.)
This change does not introduce the two 64-bit types, 'int64' and 'uint64'.
Their implementation is more complicated and is best left to a separate change.
compiler/prog_type.m:
compiler/prog_data.m:
compiler/builtin_lib_types.m:
Recognise int8, uint8, int16, uint16, int32 and uint32 as builtin types.
Add new type, int_type/0,that enumerates all the possible integer types.
Extend the cons_id/0 type to cover the new types.
compiler/builtin_ops.m:
Parameterize the integer operations in the unary_op/0 and binary_op/0
types by the new int_type/0 type.
Add builtin operations for all the new types.
compiler/hlds_data.m:
Add new tag types for the new types.
compiler/hlds_pred.m:
Parameterize integers in the table_trie_step/0 type.
compiler/ctgc.selector.m:
compiler/dead_proc_elim.m:
compiler/export.m:
compiler/foreign.m:
compiler/goal_util.m:
compiler/higher_order.m:
compiler/hlds_code_util.m:
compiler/hlds_dependency_graph.m:
compiler/hlds_out_pred.m:
compiler/hlds_out_util.m:
compiler/implementation_defined_literals.m:
compiler/inst_check.m:
compiler/mercury_to_mercury.m:
compiler/mode_util.m:
compiler/module_qual.qualify_items.m:
compiler/opt_debug.m:
compiler/opt_util.m:
compiler/parse_tree_out_info.m:
compiler/parse_tree_to_term.m:
compiler/parse_type_name.m:
compiler/polymorphism.m:
compiler/prog_out.m:
compiler/prog_rep.m:
compiler/prog_rep_tables.m:
compiler/prog_util.m:
compiler/rbmm.exection_path.m:
compiler/rtti.m:
compiler/rtti_to_mlds.m:
compiler/switch_util.m:
compiler/table_gen.m:
compiler/type_constraints.m:
compiler/type_ctor_info.m:
compiler/type_util.m:
compiler/typecheck.m:
compiler/unify_gen.m:
compiler/unify_proc.m:
compiler/unused_imports.m:
compiler/xml_documentation.m:
Conform to the above changes to the parse tree and HLDS.
compiler/c_util.m:
Support generating the builtin operations for the new types.
doc/reference_manual.texi:
Add the new types to the list of reserved type names.
Add the mapping from the new types to their target language types.
These are commented out for now.
compiler/llds.m:
Replace the lt_integer/0 and lt_unsigned functors of the llds_type/0,
with a single lt_int/1 functor that is parameterized by the int_type/0
type.
Add a representations for constants of the new types to the LLDS.
compiler/call_gen.m:
compiler/dupproc.m:
compiler/exprn_aux.m:
compiler/global_data.m:
compiler/jumpopt.m:
compiler/llds_out_data.m:
compiler/llds_out_global.m:
compiler/llds_out_instr.m:
compiler/lookup_switch.m:
compiler/middle_rec.m:
compiler/peephole.m:
compiler/pragma_c_gen.m:
compiler/stack_layout.m:
compiler/string_switch.m:
compiler/switch_gen.m:
compiler/tag_switch.m:
compiler/trace_gen.m:
compiler/transform_llds.m:
Support the new types in the LLDS code generator.
compiler/mlds.m:
Support constants of the new types in the MLDS.
compiler/ml_accurate_gc.m:
compiler/ml_call_gen.m:
compiler/ml_code_util.m:
compiler/ml_disj_gen.m:
compiler/ml_foreign_proc_gen.m:
compiler/ml_global_data.m:
compiler/ml_lookup_switch.m:
compiler/ml_simplify_switch.m:
compiler/ml_string_switch.m:
compiler/ml_switch_gen.m:
compiler/ml_tailcall.m:
compiler/ml_type_gen.m:
compiler/ml_unify_gen.m:
compiler/ml_util.m:
compiler/mlds_to_target_util.m:
Conform to the above changes to the MLDS.
compiler/mlds_to_c.m:
compiler/mlds_to_cs.m:
compiler/mlds_to_java.m:
Generate the appropriate target code for constants of the new
types and operations involving them.
compiler/bytecode.m:
compiler/bytecode_gen.m:
Handle the new types in the bytecode generator; we just abort if we
encounter them for now.
compiler/elds.m:
compiler/elds_to_erlang.m:
compiler/erl_call_gen.m:
compiler/erl_code_util.m:
compiler/erl_rtti.m:
compiler/erl_unify_gen.m:
Handle the new types in the Erlang code generator.
library/private_builtin.m:
Add placeholders for the builtin unify and compare operations for
the new types. Since the bootstrapping compiler will not recognise
the new types we give the polymorphic arguments. These can be
replaced after this change has bootstrapped.
Update the Java list of TypeCtorRep constants.
library/int8.m:
library/int16.m:
library/int32.m:
library/uint8.m:
library/uint16.m:
library/uint32.m:
New modules that will eventually contain builtin operations
on the new types.
library/library.m:
library/MODULES_UNDOC:
Do not include the above modules in the library documentation
for now.
library/construct.m:
library/erlang_rtti_implementation.m:
library/rtti_implementation.m:
deep_profiler/program_representation_utils.m:
mdbcomp/program_representation.m:
Handle the new types.
runtime/mercury_dotnet.cs.in:
java/runtime/TypeCtorRep.java:
runtime/mercury_type_info.h:
Update the list of TypeCtorReps.
configure.ac:
runtime/mercury_conf.h.in:
Check for the header stdint.h.
runtime/mercury_std.h:
Include stdint.h; abort if that header is no present.
runtime/mercury_builtin_types.[ch]:
runtime/mercury_builtin_types_proc_layouts.h:
runtime/mercury_construct.c:
runtime/mercury_deconstruct.c:
runtime/mercury_deep_copy_body.h:
runtime/mercury_ml_expand_body.h
runtime/mercury_table_type_body.h:
runtime/mercury_tabling_macros.h:
runtime/mercury_tabling_preds.h:
runtime/mercury_term_size.c:
runtime/mercury_unify_compare_body.h:
Add the new builtin types and handle them throughout the runtime.
|
||
|
Zoltan Somogyi
|
cc9912faa8 |
Don't import anything in packages.
Packages are modules whose only job is to serve as a container for submodules. Modules like top_level.m, hlds.m, parse_tree.m and ll_backend.m are packages in this (informal) sense. Besides the include_module declarations for their submodules, most of the packages in the compiler used to import some modules, mostly other packages whose component modules their submodules may need. For example, ll_backend.m used to import parse_tree.m. This meant that modules in the ll_backend package did not have to import parse_tree.m before importing modules in the parse_tree package. However, this had a price. When we add a new module to the parse_tree package, parse_tree.int would change, and this would require the recompilation of ALL the modules in the ll_backend package, even the ones that did NOT import ANY of the modules in the parse_tree package. This happened even at one remove. Pretty much all modules in every one of the backend have to import one or more modules in the hlds package, and they therefore have import hlds.m. Since hlds.m imported transform_hlds.m, any addition of a new middle pass to the transform_hlds package required the recompilation of all backend modules, even in the usual case of the two having nothing to do with each other. This diff removes all import_module declarations from the packages, and replaces them with import_module declarations in the modules that need them. This includes only a SUBSET of their child modules and of the non-child modules that import them. |
||
|
Zoltan Somogyi
|
81b8c91910 | Convert (C->T;E) to (if C then T else E). | ||
|
Zoltan Somogyi
|
62ec97d443 |
Report imports shadowed by other imports.
If a module has two or more import_module or use_module declarations
for the same module, (typically, but not always, one being in its interface
and one in its implementation), generate an informational message about
each redundant declaration if --warn-unused-imports is enabled.
compiler/hlds_module.m:
We used to record the set of imported/used modules, and the set of
modules imported/used in the interface of the current module. However,
these sets
- did not record the distinction between imports and uses;
- did not allow distinction between single and multiple imports/uses;
- did not record the locations of the imports/uses.
The first distinction was needed only by module_qual.m, which *did*
pay attention to it; the other two were not needed at all.
To generate messages for imports/uses shadowing other imports/uses,
we need all three, so change the data structure storing such information
for *direct* imports to one that records all three of the above kinds
of information. (For imports made by read-in interface and optimization
files, the old set of modules approach is fine, and this diff leaves
the set of thus *indirectly* imported module names alone.)
compiler/unused_imports.m:
Use the extra information now available to generate a
severity_informational message about any import or use that is made
redundant by an earlier, more general import or use.
Fix two bugs in the code that generated warnings for just plain unused
modules.
(1) It did not consider that a use of the builtin type char justified
an import of char.m, but without that import, the type is not visible.
(2) It scanned cons_ids in goals in procedure bodies, but did not scan
cons_ids that have been put into the const_struct_db. (I did not update
the code here when I added the const_struct_db.)
Also, add a (hopefully temporary) workaround for a bug in
make_hlds_passes.m, which is noted below.
However, there are at least three problems that prevent us from enabling
--warn-unused-imports by default.
(1) In some places, the import of a module is used only by clauses for
a predicate that also has foreign procs. When compiled in a grade that
selects one of those foreign_procs as the implementation of the predicate,
the clauses are discarded *without* being added to the HLDS at all.
This leads unused_imports.m to generate an uncalled-for warning in such
cases. To fix this, we would need to preserve the Mercury clauses for
*all* predicates, even those with foreign procs, and do all the semantic
checks on them before throwing them away. (I tried to do this once, and
failed, but the task should be easier after the item list change.)
(2) We have two pieces of code to generate import warnings. The one in
unused_imports.m operates on the HLDS after type and mode checking,
while module_qual.m operates on the parse tree before the creation of
the HLDS. The former is more powerful, since it knows e.g. what types and
modes are used in the bodies of predicates, and hence can generate warnings
about an import being unused *anywhere* in a module, as opposed to just
unused in its interface.
If --warn-unused-imports is enabled, we will get two separate set of
reports about an interface import being unused in the interface,
*unless* we get a type or mode error, in which case unused_imports.m
won't be invoked. But in case we do get such errors, we don't want to
throw away the warnings from module_qual.m. We could store them and
throw them away only after we know we won't need them, or just get
the two modules to generate identical error_specs for each warning,
so that the sort_and_remove_dups of the error specs will do the
throwing away for us for free, if we get that far.
(3) The valid/bug100.m test case was added as a regression test for a bug
that was fixed in module_qual.m. However the bug is still present in
unused_imports.m.
compiler/make_hlds_passes.m:
Give hlds_module.m the extra information it now needs for each item_avail.
Add an XXX for a bug that cannot be fixed right now: the setting of
the status of abstract instances to abstract_imported. (The "abstract"
part is correct; the "imported" part may not be.)
compiler/intermod.m:
compiler/try_expand.m:
compiler/xml_documentation.m:
Conform to the change in hlds_module.m.
compiler/module_qual.m:
Update the documentation of the relationship of this module
with unused_imports.m.
compiler/hlds_data.m:
Document a problem with the status of instance definitions.
compiler/hlds_out_module.m:
Update the code that prints out the module_info to conform to the change
to hlds_module.m.
Print status information about instances, which was needed to diagnose
one of the bugs in unused_imports.m. Format the output for instances
nicer.
compiler/prog_item.m:
Add a convenience predicate.
compiler/prog_data.m:
Remove a type synonym that makes things harder to understand, not easier.
compiler/modules.m:
Delete an XXX that asks for the feature this diff implements.
Add another XXX about how that feature could be improved.
compiler/Mercury.options.m:
Add some more modules to the list of modules on which the compiler
should be invoked with --no-warn-unused-imports.
compiler/*.m:
library/*.m:
mdbcomp/*.m:
browser/*.m:
deep_profiler/*.m:
mfilterjavac/*.m:
Delete unneeded imports. Many of these shadow other imports, and some
are just plain unneeded, as shown by --warn-unused-imports. In a few
modules, there were a *lot* of unneeded imports, but most had just
one or two.
In a few cases, removing an import from a module, because it *itself*
does not need it, required adding that same import to those of its
submodules which *do* need it.
In a few cases, conform to other changes above.
tests/invalid/Mercury.options:
Test the generation of messages about import shadowing on the existing
import_in_parent.m test case (although it was also tested very thoroughly
when giving me the information needed for the deletion of all the
unneeded imports above).
tests/*/*.{m,*exp}:
Delete unneeded imports, and update any expected error messages
to expect the now-smaller line numbers.
|
||
|
Zoltan Somogyi
|
4d2788ff9e |
Separate out the location-dependent parts of the code_info.
The code_info type was originally designed to be a single data structure
that holds all of the state of the LLDS code generator. It HAD to be a single
data structure then, because the DCGs we used to pass state around only
supported passing around ONE piece of state. Nevertheless, it contained
three separate kinds of information:
1 static information, which never changed during the lifetime of a code_info
structure (such as the pred and proc id of the procedure being compiled),
2 persistent information, whose updates were never undone (such as the maximum
number of temporaries that were ever needed at any one time), and
3 location dependent information, such as "which variables are stored where",
whose updates *can* be undone when the code generator jumps back to
a previously visited point in the code, e.g. to start generating code
for the next disjunct in a disjunction.
Originally, these three kinds of fields were all jumbled up together, but
about ten years ago, I grouped all the fields of the same kind together,
into substructures of code_info named code_info_static, code_info_persistent
and code_info_loc_dep respectively. This improved matters, but some problems
remained, the most important of which is that the code_info always contained
the location dependent information, even when it wasn't meaningful, and there
was no way of indicating this fact. (After initialization, the other two parts
are always meaningful.)
This diff separates out the location dependent part of the code_info
into a new type, code_loc_dep, that can be passed around independently
of the code_info, which now contains only the first two kinds of information
above. In places where the location-dependent information is not meaningful,
you don't need to have a current code_loc_dep.
This separation also makes it easier to see what updates to the code generator
state change only the persistent part (the updated code_info type), only
the location-dependent part (the new code_loc_dep type), or both.
In the process of making this change, I found several places where the
location-dependent part of the code_info (now the code_loc_dep) was being
updated, only for those updates to be thrown away, unread, a short time later.
This happened at the ends of branches in e.g. switches, with the updated
code_loc_deps being thrown away when code generation started working on
the next branch.
compiler/code_loc_dep.m:
New module containing the location-dependent part of the LLDS code
generator state. Its contents are derived from those parts of the
old contents of code_info.m that deal with location-dependent state.
Many of the predicates moved here work on only on the code_loc_dep
structure, some others work on both the code_info and code_loc_dep
structure, and a few work only on the code_info. Predicates in the last
category are in code_loc_dep.m only if they are either (a) used only
in this module, or (b) used only with other predicates in this module.
compiler/ll_backend.m:
compiler/notes/compiler_design.html:
Mention the new module.
compiler/code_info.m:
Delete the code now in code_loc_dep.m.
Make the vartypes a field in the static part of the code_info, since it is
used quite often. (We used to look it up in the proc_info every time.)
Put the declarations and definitions of the access predicates in an order
that is consistent with the order of the fields they work on.
Give some fields and predicates more descriptive names.
compiler/call_gen.m:
compiler/code_gen.m:
compiler/commit_gen.m:
compiler/dense_switch.m:
compiler/disj_gen.m:
compiler/ite_gen.m:
compiler/ll_backend.m:
compiler/lookup_switch.m:
compiler/lookup_util.m:
compiler/middle_rec.m:
compiler/par_conj_gen.m:
compiler/pragma_c_gen.m:
compiler/proc_gen.m:
compiler/string_switch.m:
compiler/switch_case.m:
compiler/switch_gen.m:
compiler/tag_switch.m:
compiler/trace_gen.m:
compiler/unify_gen.m:
compiler/var_locn.m:
Conform to and take advantage of the changes above.
Often this required passing an in/out pair of code_loc_deps as well as
an in/out pair of code_infos, but in many cases, one or more of these
would not be needed.
Don't make changes to the code_loc_dep at the end of an arm of a branched
control structure if those updates are about be thrown away when we
start generating code for the next arm.
In several cases, switch to a strategy of taking a snapshot of the
code_loc_dep before entering a branched control structure as a whole,
and restoring that state at the start of each arm. We used to take
a snapshot at the start of each branch, and restore it at its end,
to be ready for the next branch. The former is easier to make
correctness arguments about, since the code_loc_dep in an arm
often has limited scope.
Make some minor unrelated improvements, such as eliminating the
unnecessary use of solutions/2, and reordering tests for slightly
better performance.
|
||
|
Zoltan Somogyi
|
d041b83943 |
Implement string switches via tries for the MLDS backend.
The code we emit to decide which arm of the switch is selected looks like this:
case_num = -1;
switch (MR_nth_code_unit(switchvar, 0)) {
case '98':
switch (MR_nth_code_unit(switchvar, 1)) {
case '99':
if (MR_offset_streq(2, switchvar, "abc"))
case_num = 0;
break;
case '100':
if (MR_offset_streq(2, switchvar, "aceg"))
case_num = 1;
break;
}
break;
case '99':
if (MR_offset_streq(2, switchvar, "bbb"))
case_num = 2;
break;
}
The part that acts on this will look like this for lookup switches:
if (case_num < 0)
succeeded = MR_FALSE;
else {
outvar1 = vector_common[case_num].f1;
...
outvarn = vector_common[case_num].fn;
succeeded = MR_TRUE;
}
and like this for non-lookup switches:
switch (case_num) {
case 0:
<code for case 0>
break;
...
case n:
<code for case n>
break;
default: /* if the switch is can_fail */
<code for failure>
break;
}
compiler/ml_string_switch.m:
Implement both non-lookup and lookup string switches via tries,
along the lines shown above.
compiler/ml_switch_gen.m:
Invoke the predicates that implement string switches via tries
in the circumstances in which option values call for them.
For now, we generate tries only for the C backend. Once the
problems identified for mlds_to_{cs,java,managed} below are fixed,
we can enable them on those backends as well.
compiler/options.m:
doc/user_guide.texi:
Add an option that governs the minimum size of trie switches.
compiler/ml_lookup_switch.m:
Factor out the code common to the implementation of all model-non
lookup switches, both in ml_lookup_switch.m and ml_string_switch.m,
and put it all into a new exported predicate.
The previously existing MLDS implementation methods for lookup switches
all build their lookup tables from maps that maps each cons_id
in the switch cases to the values of the output arguments of those cases.
For switch cases that apply to more than one cons_id, this map had
one entry for each of those cons_ids. For tries, we need a map
from *case ids*, not *cons ids* to the outputs. Since it is
easier to convert the one-to-one case_id->outputs map to the
many-to-one cons_id->outputs map than vice versa, change the
main data structure from which lookup tables are built to store data
in a case_id->outputs format, and provide predicates for its conversion
to the other (previously the only) format.
Rename ml_gen_lookup_switch to ml_gen_atomic_lookup_swith to distinguish
it from other predicates that also generate (other kinds of) lookup
switches.
compiler/switch_util.m:
Have the types representating lookup tables represent their contents
as a map, not as the assoc list derived from the map. Previously,
we didn't do anything with the map other than flatten it to the assoc list,
but for the MLDS backend, we may now also need to convert it to another
form of map (see immediately above).
compiler/builtin_ops.m:
Add two new builtin ops. The first, string_unsafe_index_code_unit,
returns the nth code unit in a string; the second, offset_str_eq,
does a string equality test on the nth and later code units of
two strings. They are used in the implementation of tries.
compiler/c_util.m:
Add a new binop category for each new binop, since they are not like
existing binops.
Put some existing binops into their own categories as well, since
bundling them with the other ops they were bundled with seems like
a bad idea.
compiler/hlds_goal.m:
Make the identifier of switch arms in tagged_cases a separate type
from int.
compiler/mlds_to_c.m:
compiler/llds_out_data.m:
Handle the new kinds of binops.
When writing out binop expressions, we used to do a switch on the binop
to get its category, and then another switch on the category. We now
switch on the binop directory, since this much harder to write out
code using new binops badly, and should be faster to boot.
In mlds_to_c.m, also make some cosmetic changes to the output to make it
easier to read, and thus to debug.
compiler/mlds_to_il.m:
Handle the new kinds of binops.
compiler/mlds_to_cs.m:
compiler/mlds_to_java.m:
compiler/mlds_to_managed.m:
Do not handle the new kinds of binops, since doing so would require
changing the whole approach of how these modules handle binops.
Clean up some predicates.
compiler/bytecode.m:
compiler/erl_call_gen.m:
compiler/lookup_switch.m:
compiler/ml_global_data.m:
compiler/ml_optimize.m:
compiler/ml_tag_switch.m:
compiler/opt_debug.m:
compiler/string_switch.m:
Conform to the changes above.
compiler/ml_code_gen.m:
Put the predicates of this module into a consistent order.
library/string.m:
Fix white space.
runtime/mercury_string.h:
Add a macro for each of the two new builtin operations.
|
||
|
Peter Wang
|
2ccac171dd |
Add float registers to the Mercury abstract machine, implemented as an
Branches: main Add float registers to the Mercury abstract machine, implemented as an array of MR_Float in the Mercury engine structure. Float registers are only useful if a Mercury `float' is wider than a word (i.e. when using double precision floats on 32-bit platforms) so we let them exist only then. In other cases floats may simply be passed via the regular registers, as before. Currently, higher order calls still require the use of the regular registers for all arguments. As all exported procedures are potentially the target of higher order calls, exported procedures must use only the regular registers for argument passing. This can lead to more (un)boxing than if floats were simply always boxed. Until this is solved, float registers must be enabled explicitly with the developer only option `--use-float-registers'. The other aspect of this change is using two consecutive stack slots to hold a single double variable. Without that, the benefit of passing unboxed floats via dedicated float registers would be largely eroded. compiler/options.m: Add developer option `--use-float-registers'. compiler/handle_options.m: Disable `--use-float-registers' if floats are not wider than words. compiler/make_hlds_passes.m: If `--use-float-registers' is in effect, enable a previous change that allows float constructor arguments to be stored unboxed in structures. compiler/hlds_llds.m: Move `reg_type' here from llds.m and `reg_f' option. Add stack slot width to `stack_slot' type. Add register type and stack slot width to `abs_locn' type. Remember next available float register in `abs_follow_vars'. compiler/hlds_pred.m: Add register type to `arg_loc' type. compiler/llds.m: Add a new kind of lval: double-width stack slots. These are used to hold double-precision floating point values only. Record setting of `--use-float-registers' in exprn_opts. Conform to addition of float registers and double stack slots. compiler/code_info.m: Make predicates take the register type as an argument, where it can no longer be assumed. Remember whether float registers are being used. Remember max float register for calls to MR_trace. Count double width stack slots as two slots. compiler/arg_info.m: Allocate float registers for procedure arguments when appropriate. Delete unused predicates. compiler/var_locn.m: Make predicates working with registers either take the register type as an argument, or handle both register types at once. Select float registers for variables when appropriate. compiler/call_gen.m: Explicitly use regular registers for all higher-order calls, which was implicit before. compiler/pragma_c_gen.m: Use float registers, when available, at the interface between Mercury code and C foreign_procs. compiler/export.m: Whether a float rval needs to be boxed/unboxed when assigned to/from a register depends on the register type. compiler/fact_table.m: Use float registers for arguments to predicates defined by fact tables. compiler/stack_alloc.m: Allocate two consecutive stack slots for float variables when appropriate. compiler/stack_layout.m: Represent double-width stack slots in procedure layout structures. Conform to changes. compiler/store_alloc.m: Allocate float registers (if they exist) for float variables. compiler/use_local_vars.m: Substitute float abstract machine registers with MR_Float local variables. compiler/llds_out_data.m: compiler/llds_out_instr.m: Output float registers and double stack slots. compiler/code_util.m: compiler/follow_vars.m: Count float registers separately from regular registers. compiler/layout.m: compiler/layout_out.m: compiler/trace_gen.m: Remember the max used float register for calls to MR_trace(). compiler/builtin_lib_types.m: Fix incorrect definition of float_type_ctor. compiler/bytecode_gen.m: compiler/continuation_info.m: compiler/disj_gen.m: compiler/dupelim.m: compiler/exprn_aux.m: compiler/global_data.m: compiler/hlds_out_goal.m: compiler/jumpopt.m: compiler/llds_to_x86_64.m: compiler/lookup_switch.m: compiler/opt_debug.m: compiler/opt_util.m: compiler/par_conj_gen.m: compiler/proc_gen.m: compiler/string_switch.m: compiler/tag_switch.m: compiler/tupling.m: compiler/x86_64_regs.m: Conform to changes. runtime/mercury_engine.h: Add an array of fake float "registers" to the Mercury engine structure, when MR_Float is wider than MR_Word. runtime/mercury_regs.h: Document float registers in the Mercury abstract machine. Add macros to access float registers in the Mercury engine. runtime/mercury_stack_layout.h: Add new MR_LongLval cases to represent double-width stack slots. MR_LONG_LVAL_TAGBITS had to be increased to accomodate the new cases, which increases the number of integers in [0, 2^MR_LONG_LVAL_TAGBITS) equal to 0 modulo 4. These are the new MR_LONG_LVAL_TYPE_CONS_n cases. Add max float register field to MR_ExecTrace. runtime/mercury_layout_util.c: runtime/mercury_layout_util.h: Extend MR_copy_regs_to_saved_regs and MR_copy_saved_regs_to_regs for float registers. Understand how to look up new kinds of MR_LongLval: MR_LONG_LVAL_TYPE_F (previously unused), MR_LONG_LVAL_TYPE_DOUBLE_STACKVAR, MR_LONG_LVAL_TYPE_DOUBLE_FRAMEVAR. Conform to the new MR_LONG_LVAL_TYPE_CONS_n cases. runtime/mercury_float.h: Delete redundant #ifdef. runtime/mercury_accurate_gc.c: runtime/mercury_agc_debug.c: Conform to changes (untested). trace/mercury_trace.c: trace/mercury_trace.h: trace/mercury_trace_declarative.c: trace/mercury_trace_external.c: trace/mercury_trace_internal.c: trace/mercury_trace_spy.c: trace/mercury_trace_vars.c: trace/mercury_trace_vars.h: Handle float registers in the trace subsystem. This is mostly a matter of saving/restoring them as with regular registers. |
||
|
Peter Wang
|
4c2846593a |
Make it possible to store double-precision `float' constructor arguments in
Branches: main Make it possible to store double-precision `float' constructor arguments in unboxed form, in low-level C grades on 32-bit platforms, i.e. `float' (and equivalent) arguments may occupy two machine words. However, until we implement float registers, this does more harm than good so it remains disabled. compiler/llds.m: Add a type `cell_arg' to hold information about an argument of a cell being constructed. Change `heap_ref' so that we can refer to a pointer with an unknown tag. compiler/unify_gen.m: Use the `cell_arg' type to simplify code related to generating constructions. Handle double word arguments in constructions and deconstructions. Update enumeration packing code to account for the presence of double width arguments and the `cell_arg' type. Take double width arguments into account when generating ground terms. compiler/code_info.m: Extend `assign_field_lval_expr_to_var' to work for expressions involving multiple field lvals of the same variable. Make `assign_cell_to_var' conform to changes. compiler/code_util.m: Add a predicate to calculate the size of a cell given its cell_args. compiler/var_locn.m: Conform to the use of the `cell_arg' type and the presense of double width arguments. Calculate cell size correctly in places. Move sanity checking from `var_locn_assign_field_lval_expr_to_var' to `code_info.assign_field_lval_expr_to_var'. compiler/global_data.m: Make `rval_type_as_arg' take into account the width of the argument. Conform to changes. compiler/c_util.m: Add a new binop category. Unlike the existing macro_binop category, the arguments of macros in this category cannot all be assumed to be of integral types. compiler/llds_out_data.m: compiler/llds_out_instr.m: Output calls to the macros `MR_float_word_bits', `MR_float_from_dword' and `MR_float_from_dword_ptr' which were introduced previously. When a `heap_ref' has an unknown tag, make the generated code mask off the tag bits. compiler/lco.m: Disable the optimisation when float arguments are present, on the basis of whether Mercury floats are wider than a machine word. The comments about when floats are stored in boxed form are out of date. compiler/arg_pack.m: Rename a predicate. compiler/make_hlds_passes.m: Update a comment. compiler/disj_gen.m: compiler/exprn_aux.m: compiler/global_data.m: compiler/llds_to_x86_64.m: compiler/lookup_switch.m: compiler/mlds_to_c.m: compiler/opt_debug.m: compiler/opt_util.m: compiler/stack_layout.m: compiler/string_switch.m: Conform to changes. runtime/mercury_float.h: Add a cast to `MR_float_word_bits' to avoid a gcc error. tests/hard_coded/Mercury.options: tests/hard_coded/Mmakefile: tests/hard_coded/heap_ref_mask_tag.exp: tests/hard_coded/heap_ref_mask_tag.m: tests/hard_coded/reuse_double.exp: tests/hard_coded/reuse_double.m: Add test cases. tests/hard_coded/lookup_disj.exp: tests/hard_coded/lookup_disj.m: Extend existing test case. |
||
|
Zoltan Somogyi
|
de56f9b77c |
Implement lookup table versions of hash and binary search switches for strings
Estimated hours taken: 24 Branches: main Implement lookup table versions of hash and binary search switches for strings in the MLDS backend (those versions already exist in the LLDS backend). compiler/ml_string_switch.m: Make the above change. Where possible, factor out and reuse existing code. compiler/ml_lookup_switch.m: Break up the predicate that used to both test a switch whether it is a lookup switch and also generate code for it if it was, into two parts, each doing just one job. The first part is now useful for switches on strings as well. Group auxiliary predicates with the main predicates they support. Factor out some code into new predicates, and export them for use by the new code in ml_string_switch.m. Make some predicates tail recursive. Remove some predicates made unnecessary by changes to lookup_switch.m. compiler/ml_switch_gen.m: Invoke the new code when appropriate, and conform to the updated interface of ml_lookup_switch.m. compiler/switch_util.m: Change some types, and the predicates that operate on them, to make them useful for lookup switches for the MLDS backend as well the LLDS backend. Add some utility predicates. compiler/lookup_switch.m: Change the interface of some of the predicates in this module to allow us to factor out some common code from the higher order values passed by callers. Conform to the changes in switch_util.m. compiler/string_switch.m: Conform to changes in switch_util.m. compiler/switch_gen.m: Conform to changes in lookup_switch.m. |
||
|
Zoltan Somogyi
|
6dabcc0aa1 |
Implement binary search switches for strings in the MLDS backend (they already
Estimated hours taken: 16 Branches: main Implement binary search switches for strings in the MLDS backend (they already exist in the LLDS backend). Binary search switches have higher big-O complexity than hash table search switches, but lower startup costs, and so are appropriate for switches involving a smaller tables of strings. compiler/ml_string_switch.m: Implement binary search switches. Where possible, factor out and reuse code that already existed for implementing hash switches. compiler/ml_switch_gen.m: Invoke the new code when appropriate. compiler/switch_gen.m: Avoid executing the same test (NumArms > 1) more than once. compiler/mlds.m: Fix a typo in a comment. compiler/string_switch.m: Delete stray text from a comment. |
||
|
Zoltan Somogyi
|
b4092d2e4e |
Further improvements in the implementation of string switches, along with
Estimated hours taken: 12 Branches: main Further improvements in the implementation of string switches, along with some bug fixes. If the chosen hash function does not yield any collisions for the strings in the switch arms, then we can optimize away the table column that we would otherwise need for open addressing. This was implemented in a previous diff. For an ordinary (non-lookup) string switch, the hash table has two columns in the presence of collisions and one column in their absence. Therefore if doubling the size of the table allows us to eliminate collisions, the table size is unaffected, though the corresponding array of labels we have to put into the computed_goto instruction we generate has to double as well. Thus the only cost of such doubling is an increase in "code" size, and for small tables, the elimination of the open addressing loop may compensate for this, at least partially. For lookup string switches, doubling the table size this way has a bigger space cost, but the elimination of the open addressing loop still brings a useful speed boost. We therefore now DO double the table size if this eliminates collisions. In the library, compiler etc directories, this eliminates collisions in 19 out of 47 switch switches that had collisions with the standard table size. compiler/switch_util.m: Replace the separate sets of predicates we used to have for computing hash maps (one for lookup switches and one for non-lookup switches) with a single set that works for both. Change this set to double the table size if this eliminates collisions. This requires it to decide the table size, a task previously done separately by each of its callers. One version of this set had an old bug, which caused it to effectively ignore the second and third string hash functions. This diff fixes it. There were two bugs in my previous diff: the unneeded table column was not being optimized away from several_soln lookup switches, and the lookup code for one_soln lookup switches used the wrong column offset. This diff fixes these too. Since doubling the table size requires recalculating all the hash values, decouple the computation of the hash values from generating code for each switch arm, since the latter shouldn't be done more than once. Add a note on an old problem. compiler/ml_string_switch.m: compiler/string_switch.m: Bring the code for generating code for the arms of string switches here from switch_util.m. tests/hard_coded/Mmakefile: Fix the reason why the bugs mentioned above were not detected: the relevant test cases weren't enabled. tests/hard_coded/string_hash.m: Update this test case to test the correspondence of the compiler's and the runtime's versions of not just the first hash function, but also the second and third. runtime/mercury_string.h: Fix a typo in a comment. |
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|
Zoltan Somogyi
|
fe566dbf42 |
When doing hash table lookup as part of the implementation of switches on
Estimated hours taken: 8 Branches: main When doing hash table lookup as part of the implementation of switches on strings, we use open addressing to handle collisions. However, if the chosen hash function does not yield any collisions for the strings in the switch arms, then open addressing is unnecessary: if a lookup does not find the string bound to the switch variable in its home bucket, it won't be in the hash table at all. This diff optimizes such cases, by not generating for them the loop we would otherwise use for open addressing, and optimizing away the table column telling that loop where to check next. compiler/string_switch.m: Implement the above optimization both for ordinary switches on strings, and for lookup table switches (both one_soln and several_soln) on strings. compiler/ml_string_switch.m: Implement the above optimization for ordinary switches on strings. This module does not (yet) implement lookup table switches on strings. compiler/switch_util.m: When deciding what hash function to use, return the number of collisions for string_switch and ml_string_switch to use. Rename the other_switch category to float_switch, since the only type category it covers is switches on floats. compiler/switch_gen.m: compiler/ml_switch_gen.m: Make the module header comments more organized, and use the same template for both, so one can see the differences more easily. Put the switch arms for the smart indexing methods into the same order in both files. Fix an old problem in ml_switch_gen.m: the test to see whether we can apply a smart indexing method that uses switches on integers was testing not the availability of int switches in the target, but the availability of computed gotos. While ml_simplify_switch would transform the int-switch-using code to computed-goto-using code or an if-then-else chain in *some* cases, it would not do so in *all* cases. In ml_switch_gen.m, remove a test that could not succeed, and a procedure that was used only in that test. Conform to the changes in switch_util.m. compiler/lookup_switch.m: compiler/ml_simplify_switch.m: Update comments. |
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|
Zoltan Somogyi
|
7487590f2d |
Predicates with many variables, such as some of those in zm_enums.m,
Estimated hours taken: 24 Branches: main Predicates with many variables, such as some of those in zm_enums.m, tickle pretty bad behavior in the liveness and stack_alloc passes. This is because those passes manipulate sets of variables, which in such cases are large sets of variables, and the quadratic behavior of repeated operations on sets represents as sorted lists hurts us. This diff changes the representation of the sets of variables involved in those two passes, which are the prebirth, postbirth, predeath and postdeath sets in goal_infos, to be values of an abstract type (set_of_progvar). By default, these are implemented using tree_bitsets, which have much better worst case behaviour that set_ordlists. When compiling zm_enums with debugging enabled, this diff speeds up the liveness pass by about half and the stack alloc pass by about a third, with the overall speedup being about 6% (due to some other expensive passes). On tools/speedtest -l, the result is a 3.4% slowdown. Since the slowdown worsens slightly if I make the abstract representation of sets of prog_vars be the existing representation (an ordinary set), I think this slowdown is due to the conversions that are now required in some places between the abstract representation and an explicit set(prog_var) representation. As such, as other uses of set(progvar) get converted to set_of_progvar, this slowdown should disappear. compiler/set_of_var.m: The new module that contains the set_of_progvar abstract data type. This module also contains a copy of the code of the graph_colour module. Since the set_of_progvar type is private, this is necessary if we want all the set operations done by graph colouring (which does the bulk of the work of the stack alloc pass) to use the preferred set representation. compiler/graph_colour.m: Note that this module is no longer used. compiler/stack_alloc.m: compiler/liveness.m: Switch over to using the new module. compiler/parse_tree.m: Include set_of_var among the modules of this package. (It is in this package because the prog_var type is defined in this package.) compiler/test_bitset.m: A module that allows new set implementations to be tested. It is an extended and specialized version of the bitset_tester module from tests/hard_coded. compiler/hlds_llds.m: Use the set_of_progvar type for the prebirth, postbirth, predeath and postdeath sets in goal_infos, and for other liveness-related sets of variables. compiler/code_info.m: Some of the fields of the code_info structure represent sets of variables, and some of the predicates defined by this module have arguments that are sets of variables. If these sets represent entities that are computed from prebirth, postbirth, predeath and postdeath sets or from other goal_info fields that have been changed to the set_of_progvar representation, change them to use the set_of_progvar representation as well, or, in a few cases, to plain sorted lists. Conform to the above change. compiler/proc_type.m: Add a utility predicate to operate of set_of_progvar. Replace a lambda expression with a named predicate. compiler/quantification.m: Until now, quantification.m used its own private abstract type (defined as tree_bitset) to represent sets. Make it use set_of_progvar instead, since it has the same purpose. This eliminates a potential maintenance problem. compiler/call_gen.m: compiler/code_gen.m: compiler/commit_gen.m: compiler/delay_construct.m: compiler/disj_gen.m: compiler/hlds_out_goal.m: compiler/hlds_rtti.m: compiler/interval.m: compiler/ite_gen.m: compiler/live_vars.m: compiler/lookup_switch.m: compiler/lookup_util.m: compiler/matching.m: compiler/pd_util.m: compiler/polymorphism.m: compiler/pragma_c_gen.m: compiler/proc_gen.m: compiler/simplify.m: compiler/stack_opt.m: compiler/store_alloc.m: compiler/string_switch.m: compiler/structure_reuse.lbu.m: compiler/structure_reuse.lfu.m: compiler/structure_sharing.domain.m: compiler/switch_util.m: compiler/trace_gen.m: compiler/tupling.m: compiler/unify_gen.m: compiler/unused_args.m: Conform to the above change. library/map.m: Add a utility predicate, map.select_sorted_list, which functions the same way as map.select, but takes a sorted list as argument instead of a set. library/set_ordlist.m: Bring the interface of this module closer to set.m and tree_bitset.m to make them more easily interchangeable. This required adding the predicates is_non_empty and is_singleton, as well as adding predicate forms of union_list and intersect_list. I also added missing type_spec pragmas for some predicates frequently used by the compiler. library/tree_bitset.m: Bring the interface of this module closer to set.m and set_ordlist.m to make them more easily interchangeable. This required adding the predicates is_non_empty and is_singleton, and both function and predicate forms of union_list and intersect_list. Fix an old bug in the difference operation. Given SetA - SetB, if SetA was the empty set, then this operation would correctly return the empty set if SetB was small (represented by a leaf list), but would incorrectly return SetB if it was large (represented by an interior node list). |
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|
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. |
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|
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. |
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|
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. |
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|
Zoltan Somogyi
|
59989c95a8 |
Fix Mantis bug #170.
Estimated hours taken: 4 Branches: main Fix Mantis bug #170. The problem involved a string switch inlined into the condition of an if-then-else in the predicate execute_cmd_string. The switched-on variable, CmdWord, is not used in or after the switch in the condition or the then part, so it becomes forward dead in the switch, but it IS used in the else part. This requires it to be made a zombie when it forward dies, so it can be resurrected at the start of the else part. The initial implementation of string hash lookup switches did not do that. compiler/string_switch.m: Fix the bug by making all variables being made forward dead into zombies if they are needed by an enclosing resume point. compiler/lookup_switch.m: Fix the same bug in switches on atomic types. compiler/var_locn.m: Fix the format of some documentation. ssdb/Mercury.options: Remove the workaround for bug #170, since it won't be needed once the diff to the compiler is installed. tests/hard_coded/lookup_switch_simple_cond.{m,exp}: A version of the existing lookup_switch_simple test case that puts the switch in a condition, to test the fix to lookup_switch.m. The compilation of ssdb/ssdb.m with -O5 is the test case for the fix to string_switch.m. tests/hard_coded/Mmakefile: Enable the new test case. |
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Zoltan Somogyi
|
bf5c9a79a5 |
Until now, all hash tables on strings used a single standard hash function.
Estimated hours taken: 3 Branches: main Until now, all hash tables on strings used a single standard hash function. However, any single hash function has a pretty good probability of generating collisions on small hash tables. This diff adds two new hash functions on strings. When generating hash tables, we now try out all three hash functions, and use the one that generates the fewest collisions. runtime/mercury_string.h: Add C implementations of the new hash functions. library/string.m: Add Mercury implementations of the new hash functions. compiler/builtin_ops.m: Add the new hash functions as builtin operations. compiler/switch_util.m: Select the best hash function for each hash switch on strings. compiler/ml_string_switch.m: compiler/string_switch.m: Use the selected hash function for each hash table. compiler/bytecode.m: compiler/c_util.m: compiler/java_util.m: compiler/llds.m: compiler/llds_tox86_64.m: compiler/mlds_to_gcc.m: compiler/mlds_to_il.m: compiler/opt_debumlds_to_ilg.m: Conform to the presence of the new hash functions. |
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Zoltan Somogyi
|
4db9b2adbf |
Until now, the only indexing we did for switches on strings was using a hash
Estimated hours taken: 40
Branches: main
Until now, the only indexing we did for switches on strings was using a hash
table containing jump targets (represented as indices into a list of labels).
This diff supplements this with
- binary searches of tables containing jump targets,
- binary searches of tables containing values (lookup tables), and
- hash searches of tables containing values (lookup tables).
For now, the new methods exist in the LLDS backend only.
NEWS:
Mention the new capability.
compiler/string_switch.m:
Add predicates that implement the new indexing methods on strings.
Factor out code from existing predicates as required for this.
compiler/switch_gen.m:
Invoke the new predicates in string_switch.m when relevant.
Avoid passing the constant "no" as the initial value of !MaybeEnd
to predicates where we know this will ALWAYS happen.
compiler/options.m:
doc/user_guide.texi:
Add an option to control when we use binary searches for switches
on strings.
compiler/lookup_switch.m:
This module previously handled lookup switches on integers.
Generalize it so that pieces of it are now also usable to help
implement lookup switches on strings. Rename the predicates specific
to switches on integers to make clear this specificity, and separate
them from the predicates that help implement lookup switches on
variables of all the supported types.
Export some types, predicates and functions for use in string_switch.m.
Fix the code so that it correctly handles det switches, which
can happen e.g. if we know the possible set of values of the
switched-on variable.
Use tail-recursive code to handle the list of switch arms, to allow us
to handle very large switches.
Remove an obsolete comment from the top about a previously implemented
optimization.
compiler/lookup_util.m:
Make set_liveness_and_end_branch update MaybeEnd, to account for the
reservation of stack slots for holding the current and last rows in
later solutions tables for model_non lookup switches.
compiler/switch_util.m:
Make the exported predicates of this module more general, making them
usable for switches on strings as well as ints. Also make them easier
to use. In one case this meant bundling two predicates that were always
used together into one predicate. In another, it meant splitting one
predicate into two, since some of its callers needed an intermediate
result. In the case of a type, it means reordering its fields
to make the order match the order of their use in the implementation.
Add some predicates specifically for switches on strings.
compiler/ml_lookup_switch.m:
compiler/ml_string_switch.m:
compiler/ml_switch_gen.m:
Conform to the changes to switch_util.m.
compiler/jumpopt.m:
If the comment associated with a label ends with "nofulljump", then
inhibit fulljump optimization of jumps to that label. That
optimization would replace the jumps with the code starting at that
label. This is avoids the overhead of jump instructions, and it is a
good idea in the usual case of forward jumps. However, for the few
backward jumps we generate, the block that replaces the jump
instruction can actually END with the same jump instruction (which may
be conditionally executed), which means that our usual repeated
invocation of jumpopt can replace the original jump instruction
with MANY copies of the block it jumps to. In some cases, such as those
in hash switches, you get more copies than can ever be executed in any
actual execution. Lookup switches therefore now mark the labels that
are targets of backward jumps with this marker.
compiler/llds.m:
Document the new behavior of jumpopt.
compiler/code_info.m:
Export a predicate for use in improving the code we generate for lookup
switches.
Make some other predicates simpler and/or more efficient.
compiler/builtin_ops.m:
Add a builtin op for doing string comparisons by calling strcmp.
This is to prevent the need for two traversals of the strings being
compared in each iteration of binary search.
compiler/bytecode.m:
compiler/c_util.m:
compiler/mlds_to_gcc.m:
compiler/mlds_to_il.m:
compiler/llds.m:
compiler/llds_to_x86_64.m:
Conform to the change in builtin_ops.m.
compiler/disj_gen.m:
Conform to the change in lookup_util.m
compiler/frameopt.m:
compiler/proc_gen.m:
compiler/unify_gen.m:
Take advantage of the change in fulljump optimization.
compiler/opt_debug.m:
Improve the string representation of rvals by recording the types of
the operands of binary operations, and making the output a bit more
consistent looking.
compiler/dupproc.m:
compiler/var_locn.m:
Minor style fixes.
runtime/mercury_string.h:
Add a version of strcmp for use by our code generator. This version
casts the arguments before calling the real strcmp. We need it since we
usually specify the arguments as r1, r2 etc, which are declared as
MR_Word, not char *.
tests/hard_coded/lookup_disj.{m,exp}:
tests/hard_coded/string_switch.{m,exp}:
Make these existing tests significantly tougher by making them exercise
a wider range of use scenarios.
tests/hard_coded/string_switch{2,3}.{m,exp}:
tests/hard_coded/Mercury.options
While the string_switch test case tests the handling of jump switches,
these two new test cases test the handling of binary search tables and
hash tables respectively. Their code is identical to the code of
the string_switch test case, but Mercury.options causes them to be
compiled with different options.
tests/hard_coded/int_switch.{m,exp}:
A new test case, equivalent in structure to the string switch test
cases, to test the handling of lookup switches on atomic values.
|
||
|
Zoltan Somogyi
|
00ea415659 |
Implement scalar and vector global data for the MLDS backend, modelled on
Estimated hours taken: 32
Branches: main
Implement scalar and vector global data for the MLDS backend, modelled on
the implementation of global data for the LLDS backend. Use scalar global
data to eliminate redundant copies of static memory cells. Use vector global
data to implement lookup switches, and to implement string switches more
efficiently.
The diff reduces the compiler executable's size by 3.3% by eliminating
duplicate copies of static cells. The diff can reduce the sizes of object files
not only through this reduction in the size of read-only data, but also through
reductions in the size of the needed relocation info: even in the absence of
duplicated cells, using one global variable that holds an array of all the
cells of the same type requires less relocation info than a whole bunch of
separate global variables each holding one cell. If C debugging is enabled,
we can also expect a significant reduction in the size of the debug information
stored in object files AND in executables, for the same reason. (This was the
original motivation for scalar static data on the LLDS backend; the large
amount of relocation information in object files, especially if Mercury
debugging was enabled, led to long link times.)
compiler/ml_global_data.m:
Make the changes described above.
compiler/ml_lookup_switch.m:
This new module implements lookup switches for the MLDS backend.
For now, it implements only model_det and model_semi switches.
compiler/ml_switch_gen.m:
Call the new module when appropriate.
Do not require the switch generation methods that never generate
definitions to return an empty list of definitions.
compiler/ml_backend.m:
Add the new module.
compiler/notes/compiler_design.html:
Mention the new module, and fix some documentation rot.
compiler/mlds.m:
Extend the relevant types to allow the generated MLDS code to refer
to both scalar and vector global data.
Move a predicate that belongs here from ml_code_util.m.
Rename a predicate to avoid ambiguity with its own return type.
Give the functors of some types distinguishing prefixes.
compiler/ml_util.m:
Replace some semidet predicates with functions returning bool,
since the semidet predicates silently did the wrong thing on the new
additions to the MLDS.
compiler/ml_code_gen.m:
Ensure that we do not generate references to scalar and vector common
cells on platforms which do not (yet) support them. At the moment,
they are supported only when generating C.
Put some code into a predicate of its own.
compiler/builtin_ops.m:
Extend the type that represents array elements to allow them to be
structures, which they are for vector globals.
compiler/ml_code_util.m:
Add some new utility predicates and functions.
Move some predicates that are now needed in more than one module here.
Remove the predicates moved to mlds.m.
Conform to the changes above.
compiler/ml_string_switch.m:
compiler/string_switch.m:
Instead of two separate arrays, use one array of structures (a static
vector), since they way, the string and the next slot indicator,
which are accesses together, are next to each other and thus
in the same cache block.
compiler/lookup_switch.m:
compiler/switch_util.m:
Move several predicates from lookup_switch.m to switch_util.m,
since now ml_lookup_switch.m needs them too. Parameterize the moved
predicates as needed.
Conform to the changes above.
compiler/llds.m:
Add prefixes to some functor names to avoid ambiguities.
compiler/llds_out.m:
compiler/lookup_util.m:
compiler/mercury_compile.m:
Minor style improvements.
compiler/global_data.m:
Minor cleanups. Give names to some data types, and add prefixes to some
field names.
Conform to the changes above.
compiler/jumpopt.m:
Minor style improvements.
Conform to the changes above.
compiler/opt_debug.m:
Fix some misleading variable names.
compiler/reassign.m:
Factor out some duplicated code.
compiler/ll_pseudo_type_info.m:
compiler/ml_closure_gen.m:
compiler/ml_elim_nested.m:
compiler/ml_optimize.m:
compiler/ml_tag_switch.m:
compiler/ml_tailcall.m:
compiler/ml_unify_gen.m:
compiler/mlds_to_c.m:
compiler/mlds_to_gcc.m:
compiler/mlds_to_il.m:
compiler/mlds_to_java.m:
compiler/mlds_to_managed.m:
compiler/rtti_to_mlds.m:
compiler/stack_layout.m:
compiler/unify_gen.m:
Conform to the changes above.
tests/hard_coded/lookup_switch_simple.{m,exp}:
tests/hard_coded/lookup_switch_simple_bitvec.{m,exp}:
tests/hard_coded/lookup_switch_simple_non.{m,exp}:
tests/hard_coded/lookup_switch_simple_opt.{m,exp}:
New test cases to exercise the new functionality.
tests/hard_coded/Mmakefile:
tests/hard_coded/Mercury.options:
Enable the new tests.
|
||
|
Zoltan Somogyi
|
1373003785 |
Delete the old tree.m module (which did a small subset of what cords now do),
Estimated hours taken: 6 Branches: main Delete the old tree.m module (which did a small subset of what cords now do), and switch to using cords instead. This is more standard, as well as very slightly more efficient, because with cords, e.g. concatenating ten code fragments of which eight are empty doesn't allocate ten cons cells. My measurements show a 0.1% reduction in executable size and a 0.3% reduction in compilation time. Both of those are in the noise; the main reason for the change is more convenient coding. compiler/tree.m: Remove this module. compiler/libs.m: Remove the inclusion of tree.m. compiler/notes/compiler_design.html: Remove the description of tree.m. compiler/bytecode.m: Switch to using cords to represent code in the bytecode backend. compiler/llds.m: Switch to using cords to represent code in the LLDS backend. compiler/mlds_to_il.m: Switch to using cords to represent IL code being built. compiler/bytecode_gen.m: compiler/call_gen.m: compiler/code_gen.m: compiler/code_info.m: compiler/commit_gen.m: compiler/dense_switch.m: compiler/disj_gen.m: compiler/ite_gen.m: compiler/lookup_switch.m: compiler/lookup_util.m: compiler/middle_rec.m: compiler/par_conj_gen.m: compiler/pragma_c_gen.m: compiler/proc_gen.m: compiler/string_switch.m: compiler/switch_case.m: compiler/switch_gen.m: compiler/tag_switch.m: compiler/trace_gen.m: compiler/unify_gen.m: compiler/var_locn.m: Conform to the changes above. library/cord.m: Add a predicate form of map. |
||
|
Zoltan Somogyi
|
cc88711d63 |
Implement true multi-cons_id arm switches, i.e. switches in which we associate
Estimated hours taken: 40
Branches: main
Implement true multi-cons_id arm switches, i.e. switches in which we associate
more than one cons_id with a switch arm. Previously, for switches like this:
(
X = a,
goal1
;
( X = b
; X = c
),
goal2
)
we duplicated goal2. With this diff, goal2 won't be duplicated. We still
duplicate goals when that is necessary, i.e. in cases which the inner
disjunction contains code other than a functor test on the switched-on var,
like this:
(
X = a,
goal1
;
(
X = b,
goalb
;
X = c
goalc
),
goal2
)
For now, true multi-cons_id arm switches are supported only by the LLDS
backend. Supporting them on the MLDS backend is trickier, because some MLDS
target languages (e.g. Java) don't support the concept at all. So when
compiling to MLDS, we still duplicate the goal in switch detection (although
we could delay the duplication to just before code generation, if we wanted.)
compiler/options.m:
Add an internal option that tells switch detection whether to look for
multi-cons_id switch arms.
compiler/handle_options.m:
Set this option based on the back end.
Add a version of the "trans" dump level that doesn't print unification
details.
compiler/hlds_goal.m:
Extend the representation of switch cases to allow more than one
cons_id for a switch arm.
Add a type for representing switches that also includes tag information
(for use by the backends).
compiler/hlds_data.m:
For du types, record whether it is possible to speed up tests for one
cons_id (e.g. cons) by testing for the other (nil) and negating the
result. Recording this information once is faster than having
unify_gen.m trying to compute it from scratch for every single
tag test.
Add a type for representing a cons_id together with its tag.
compiler/hlds_out.m:
Print out the cheaper_tag_test information for types, and possibly
several cons_ids for each switch arm.
Add some utility predicates for describing switch arms in terms of
which cons_ids they are for.
Replace some booleans with purpose-specific types.
Make hlds_out honor is documentation, and not print out detailed
information about unifications (e.g. uniqueness and static allocation)
unless the right character ('u') is present in the control string.
compiler/add_type.m:
Fill in the information about cheaper tag tests when adding a du type.
compiler/switch_detection.m:
Extend the switch detection algorithm to detect multi-cons_id switch
arms.
When entering a switch arm, update the instmap to reflect that the
switched-on variable can now be bound only to the cons_ids that this
switch arm is for. We now need to do this, because if the arm contains
another switch on the same variable, computing the can_fail field of
that switch correctly requires us to know this information.
(Obviously, an arm for a single cons_id is unlikely to have switch on
the same variable, and for arms for several cons_ids, we previously
duplicated the arm and left the unification with the cons_id in each
copy, and this unification allowed the correct handling of any later
switches. However, the code of a multi-cons_id switch arm obviously
cannot have a unification with each cons_id in it, which is why
we now need to get the binding information from the switch itself.)
Replace some booleans with purpose-specific types, and give some
predicates better names.
compiler/instmap.m:
Provide predicates for recording that a switched-on variable has
one of several given cons_ids, for use at the starts of switch arms.
Give some predicates better names.
compiler/modes.m:
Provide predicates for updating the mode_info at the start of a
multi-cons_id switch arm.
compiler/det_report.m:
Handle multi-cons_id switch arms.
Update the instmap when entering each switch arm, since this is needed
to provide good (i.e. non-misleading) error messages when one switch on
a variable exists inside another switch on the same variable.
Since updating the instmap requires updating the module_info (since
the new inst may require a new entry in an inst table), thread the
det_info through as updateable state.
Replace some multi-clause predicate definitions with single clauses,
to make it easier to print the arguments in mdb.
Fix some misleading variable names.
compiler/det_analysis.m:
Update the instmap when entering each switch arm and thread the
det_info through as updateable state, since the predicates we call
in det_report.m require this.
compiler/det_util.m:
Handle multi-cons_id switch arms.
Rationalize the argument order of some access predicates.
compiler/switch_util.m:
Change the parts of this module that deal with string and tag switches
to optionally convert each arm to an arbitrary representation of the
arm. In the LLDS backend, the conversion process generated code for
the arm, and the arm's representation is the label at the start of
this code. This way, we can duplicate the label without duplicating
the code.
Add a new part of this module that associates each cons_id with its
tag, and (during the same pass) checks whether all the cons_ids are
integers, and if so what are min and max of these integers (needed
for dense switches). This scan is needed because the old way of making
this test had single-cons_id switch arms as one of its basic
assumptions, and doing it while adding tags to each case reduces
the number of traversals required.
Give better names to some predicates.
compiler/switch_case.m:
New module to handle the tasks associated with managing multi-cons_id
switch arms, including representing them for switch_util.m.
compiler/ll_backend.m:
Include the new module.
compiler/notes/compiler_design.html:
Note the new module.
compiler/llds.m:
Change the computed goto instruction to take a list of maybe labels
instead of a list of labels, with any missing labels meaning "not
reached".
compiler/string_switch.m:
compiler/tag_switch.m:
Reorganize the way these modules work. We can't generate the code of
each arm in place anymore, since it is now possible for more than one
cons_id to call for the execution of the same code. Instead, in
string_switch.m, we generate the codes of all the arms all at once,
and construct the hash index afterwards. (This approach simplifies
the code significantly.)
In tag switches (unlike string switches), we can get locality benefits
if the code testing for a cons_id is close to the code for that
cons_id, so we still try to put them next to each other when such
a locality benefit is available.
In both modules, the new approach uses a utility predicate in
switch_case.m to actually generate the code of each switch arm,
eliminating several copies the same code in the old versions of these
modules.
In tag_switch.m, don't create a local label that simply jumps to the
code address do_not_reached. Previously, we had to do this for
positions in jump tables that corresponded to cons_ids that the switch
variable could not be bound to. With the change to llds.m, we now
simply generate a "no" instead.
compiler/lookup_switch.m:
Get the info about int switch limits from our caller; don't compute it
here.
Give some variables better names.
compiler/dense_switch.m:
Generate the codes of the cases all at once, then assemble the table,
duplicate the labels as needed. This separation of concerns allows
significant simplifications.
Pack up all the information shared between the predicate that detects
whether a dense switch is appropriate and the predicate that actually
generates the dense switch.
Move some utility predicates to switch_util.
compiler/switch_gen.m:
Delete the code for tagging cons_ids, since that functionality is now
in switch_util.m.
The old version of this module could call the code generator to produce
(i.e. materialize) the switched-on variable repeatedly. We now produce
the variable once, and do the switch on the resulting rval.
compiler/unify_gen.m:
Use the information about cheaper tag tests in the type constructor's
entry in the HLDS type table, instead of trying to recompute it
every time.
Provide the predicates switch_gen.m now needs to perform tag tests
on rvals, as opposed to variables, and against possible more than one
cons_id.
Allow the caller to provide the tag corresponding to the cons_id(s)
in tag tests, since when we are generating code for switches, the
required computations have already been done.
Factor out some code to make all this possible.
Give better names to some predicates.
compiler/code_info.m:
Provide some utility predicates for the new code in other modules.
Give better names to some existing predicates.
compiler/hlds_code_util.m:
Rationalize the argument order of some predicates.
Replace some multi-clause predicate definitions with single clauses,
to make it easier to print the arguments in mdb.
compiler/accumulator.m:
compiler/add_heap_ops.m:
compiler/add_pragma.m:
compiler/add_trail_ops.m:
compiler/assertion.m:
compiler/build_mode_constraints.m:
compiler/check_typeclass.m:
compiler/closure_analysis.m:
compiler/code_util.m:
compiler/constraint.m:
compiler/cse_detection.m:
compiler/dead_proc_elim.m:
compiler/deep_profiling.m:
compiler/deforest.m:
compiler/delay_construct.m:
compiler/delay_partial_inst.m:
compiler/dep_par_conj.m:
compiler/distance_granularity.m:
compiler/dupproc.m:
compiler/equiv_type_hlds.m:
compiler/erl_code_gen.m:
compiler/exception_analysis.m:
compiler/export.m:
compiler/follow_code.m:
compiler/follow_vars.m:
compiler/foreign.m:
compiler/format_call.m:
compiler/frameopt.m:
compiler/goal_form.m:
compiler/goal_path.m:
compiler/goal_util.m:
compiler/granularity.m:
compiler/hhf.m:
compiler/higher_order.m:
compiler/implicit_parallelism.m:
compiler/inlining.m:
compiler/inst_check.m:
compiler/intermod.m:
compiler/interval.m:
compiler/lambda.m:
compiler/lambda.m:
compiler/lambda.m:
compiler/lco.m:
compiler/live_vars.m:
compiler/livemap.m:
compiler/liveness.m:
compiler/llds_out.m:
compiler/llds_to_x86_64.m:
compiler/loop_inv.m:
compiler/make_hlds_warn.m:
compiler/mark_static_terms.m:
compiler/middle_rec.m:
compiler/ml_tag_switch.m:
compiler/ml_type_gen.m:
compiler/ml_unify_gen.m:
compiler/mode_constraints.m:
compiler/mode_errors.m:
compiler/mode_util.m:
compiler/opt_debug.m:
compiler/opt_util.m:
compiler/pd_cost.m:
compiler/pd_into.m:
compiler/pd_util.m:
compiler/peephole.m:
compiler/polymorphism.m:
compiler/post_term_analysis.m:
compiler/post_typecheck.m:
compiler/purity.m:
compiler/quantification.m:
compiler/rbmm.actual_region_arguments.m:
compiler/rbmm.add_rbmm_goal_infos.m:
compiler/rbmm.condition_renaming.m:
compiler/rbmm.execution_paths.m:
compiler/rbmm.points_to_analysis.m:
compiler/rbmm.region_transformation.m:
compiler/recompilation.usage.m:
compiler/saved_vars.m:
compiler/simplify.m:
compiler/size_prof.m:
compiler/ssdebug.m:
compiler/store_alloc.m:
compiler/stratify.m:
compiler/structure_reuse.direct.choose_reuse.m:
compiler/structure_reuse.indirect.m:
compiler/structure_reuse.lbu.m:
compiler/structure_reuse.lfu.m:
compiler/structure_reuse.versions.m:
compiler/structure_sharing.analysis.m:
compiler/table_gen.m:
compiler/tabling_analysis.m:
compiler/term_constr_build.m:
compiler/term_norm.m:
compiler/term_pass1.m:
compiler/term_traversal.m:
compiler/trailing_analysis.m:
compiler/transform_llds.m:
compiler/tupling.m:
compiler/type_ctor_info.m:
compiler/type_util.m:
compiler/unify_proc.m:
compiler/unique_modes.m:
compiler/unneeded_code.m:
compiler/untupling.m:
compiler/unused_args.m:
compiler/unused_imports.m:
compiler/xml_documentation.m:
Make the changes necessary to conform to the changes above, principally
to handle multi-cons_id arm switches.
compiler/ml_string_switch.m:
Make the changes necessary to conform to the changes above, principally
to handle multi-cons_id arm switches.
Give some predicates better names.
compiler/dependency_graph.m:
Make the changes necessary to conform to the changes above, principally
to handle multi-cons_id arm switches. Change the order of arguments
of some predicates to make this easier.
compiler/bytecode.m:
compiler/bytecode_data.m:
compiler/bytecode_gen.m:
Make the changes necessary to conform to the changes above, principally
to handle multi-cons_id arm switches. (The bytecode interpreter
has not been updated.)
compiler/prog_rep.m:
mdbcomp/program_representation.m:
Change the byte sequence representation of goals to allow switch arms
with more than one cons_id. compiler/prog_rep.m now writes out the
updated representation, while mdbcomp/program_representation.m reads in
the updated representation.
deep_profiler/mdbprof_procrep.m:
Conform to the updated program representation.
tools/binary:
Fix a bug: if the -D option was given, the stage 2 directory wasn't
being initialized.
Abort if users try to give that option more than once.
compiler/Mercury.options:
Work around bug #32 in Mantis.
|
||
|
Zoltan Somogyi
|
342bacfee9 |
Remove a bunch of unnecessary module qualifications on calls to
Estimated hours taken: 0.1 Branches: main compiler/*.m: Remove a bunch of unnecessary module qualifications on calls to predicates in code_info.m, since they tend to cause bad line breaks. |
||
|
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? |
||
|
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. |
||
|
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. |
||
|
Zoltan Somogyi
|
00741b0162 |
This diff contains no algorithmic changes.
Estimated hours taken: 6 Branches: main This diff contains no algorithmic changes. It merely renames apart a bunch more function symbols to reduce ambiguity. After this diff, the summary line from the mdb command "ambiguity -f" is Total: 351 names used 975 times, maximum 31, average: 2.78 browser/*.m: compiler/*.m: Rename function symbols to eliminate ambiguities. tests/debugger/declarative/dependency.exp: tests/debugger/declarative/dependency2.exp: Update the expected out where some internal function symbol names appear in the output of the debugger. (This output is meant for implementors only.) |
||
|
Zoltan Somogyi
|
2b2f3d3cbe |
This diff contains no algorithmic changes.
Estimated hours taken: 8 Branches: main This diff contains no algorithmic changes. It merely renames apart a bunch of function symbols to reduce ambiguity. Basically I went through prog_data.m, prog_item.m, hlds_data.m, hlds_goal.m and hlds_pred.m looking for type definitions containing function symbol names that were either language "keywords" (e.g. "terminates", which is an annotation on foreign_procs), used with slightly different meanings in several types (e.g. "sym"), or both (e.g. "call"). When I found such type definitions, I changed the names of the function symbols, usually by adding a prefix or suffix indicating the type to all function symbols of the type. For example, the old function symbol "foreign_proc" in type "pragma_type" is now named "pragma_foreign_proc", and the names of all other function symbols in that type also start with "pragma_". All of this should yield simpler compiler error messages when we make mistakes, and will make it more likely that looking up a function symbol using a tags file will take you to the actual definition of the relevant instance of that function symbol. However, the most important benefit is the increase in the readability of unfamiliar code; the reader won't have to emulate the compiler's type ambiguity resolution algorithm (which in many cases used to require distinguishing between f/14 and f/15 by counting the arguments, e.g. for "pred_or_func"). compiler/prog_data.m: compiler/prog_item.m: compiler/hlds_data.m: compiler/hlds_goal.m: compiler/hlds_pred.m: Rename function symbols as explained above. compiler/*.m: Conform to the function symbol renames. In some cases, rename other function symbols as well. Minor style fixes, e.g. replace if-then-elses with switches, or simple det predicates with functions. |
||
|
Julien Fischer
|
aeeedd2c13 |
Standardize formatting of comments at the beginning of modules.
compiler/*.m: Standardize formatting of comments at the beginning of modules. |
||
|
Zoltan Somogyi
|
9d23d8e2e7 |
Implement the trace goal construct we discussed, for now for the LLDS backends
Estimated hours taken: 70
Branches: main
Implement the trace goal construct we discussed, for now for the LLDS backends
only.
Since the syntax of trace goals is non-trivial, useful feedback on syntax
errors inside trace goal attributes is essential. With the previous setup, this
wasn't possible, since the code that turned terms into parse tree goals turned
*all* terms into goals; it couldn't recognize any errors, sweeping them under
the rug as calls. This diff changes that. Now, if this code recognizes a
keyword that indicates a particular construct, it insists on the rest of the
code following the syntax required for that construct, and returns error
messages if it doesn't.
We handle the trace goal attributes that specify state variables to be threaded
through the trace goal (either the I/O state or a mutable variable) in
add_clause.m, at the point at which we transform the list of items to the HLDS.
We handle the compile-time condition on trace goals in the invocation of
simplify at the end of semantics analysis, by eliminating the goal if the
compile-time condition isn't met. We handle run-time conditions on trace goals
partially in the same invocation of simplify: we transform trace goals with
runtime conditions into an if-then-else with the trace goal as the then part
and `true' as the else part, the condition being a foreign_proc that is handled
specially by the code generator, that special handling being to replace
the actual code of the foreign_proc (which is a dummy) with the evaluation of
the runtime condition.
Since these changes require significant changes to some of our key data
structures, I took the liberty of doing some renaming of function symbols
at the same time to avoid using ambiguities with respect to language keywords.
library/ops.m:
Add "trace" as an operator.
compiler/prog_data.m:
Define data types to represent the various attributes of trace goals.
Rename some function symbols to avoid ambiguities.
compiler/prog_item.m:
Extend the parse tree representation of goals with a trace goal.
compiler/mercury_to_mercury.m:
Output the new kind of goal and its components.
compiler/hlds_goal.m:
Extend the HLDS representation of scopes with a scope_reason
representing trace goals.
Add a mechanism (an extra argument in foreign_procs) to allow
the representation of goals that evaluate runtime trace conditions.
Since this requires modifying all code that traverses the HLDS,
do some renames that were long overdue: rename not as negation,
rename call as plain_call, and rename foreign_proc as
call_foreign_proc. These renames all avoid using language keywords
as function symbols.
Change the way we record goals' purities. Instead of optional features
to indicate impure or semipure, which is error-prone, use a plain
field in the goal_info, accessed in the usual way.
Add a way to represent that a goal contains a trace goal, and should
therefore be treated as if it were impure when considering whether to
optimize it away.
Reformat some comments describing function symbols.
compiler/hlds_out.m:
Output the new construct in the HLDS.
compiler/prog_io_util.m:
Generalize the maybe[123] types to allow the representation of more
than one error message. Add functions to extract the error messages.
Add a maybe4 type. Rename the function symbols of these types to
avoid massive ambiguity.
Change the order of some predicates to bring related predicates
next to each other.
compiler/prog_io.m:
compiler/prog_io_dcg.m:
compiler/prog_io_goal.m:
compiler/prog_io_pragma.m:
Rework these modules almost completely to find and accumulate syntax
errors as terms are being parsed. In some cases, this allowed us to
replace "XXX this is a hack" markers with meaningful error-reporting
code.
In prog_io_goal.m, add code for parsing trace goals.
In a bunch of places, update obsolete coding practices, such as using
nested chains of closures instead of simple sequential code, and
using A0 and A to refer to values of different types (terms and goals
respectively). Use more meaningful variable names.
Break up some too-large predicates.
compiler/superhomogeneous.m:
Find and accumulate syntax errors as terms are being parsed.
compiler/add_clause.m:
Add code to transform trace goals from the parse tree to the HLDS.
This is where the IO state and mutable variable attributes of trace
goals are handled.
Eliminate the practice of using the naming scheme Body0 and Body
to refer to values of different types (prog_item.goal and hlds_goal
respectively).
Use error_util for some error messages.
library/private_builtin.m:
Add the predicates referred to by the transformation in add_clause.m.
compiler/goal_util.m:
Rename a predicate to avoid ambiguity.
compiler/typecheck.m:
Do not print error messages about missing clauses if some errors have
been detected previously.
compiler/purity.m:
Instead of just computing purity, compute (and record) also whether
a goal contains a trace goal. However, treat trace goals as pure.
compiler/mode_info.m:
Add trace goals as a reason for locking variables.
Rename some function symbols to avoid ambiguity.
compiler/modes.m:
When analyzing trace goal scopes, lock the scope's nonlocal variables
to prevent them from being further instantiated.
compiler/det_analysis.m:
Insist on the code in trace goal scopes being det or cc_multi.
compiler/det_report.m:
Generate the error message if the code in a trace goal scope isn't det
or cc_multi.
compiler/simplify.m:
At the end of the front end, eliminate trace goal scopes if their
compile-time condition is false. Transform trace goals with runtime
conditions as described at the top.
Treat goals that contain trace goals as if they were impure when
considering whether to optimize them away.
compiler/mercury_compile.m:
Tell simplify when it is being invoked at the end of the front end.
Rename a predicate to avoid ambiguity.
compiler/trace_params.m:
Provide the predicates simplify.m need to be able to evaluate the trace
goal conditions regarding trace levels.
compiler/trace.m:
compiler/trace_gen.m:
Rename the trace module as trace_gen, since "trace" is now an operator.
Rename some predicates exported by the module, now that it is no longer
possible to preface calls with "trace." as a module qualifier.
compiler/notes/compiler_design.html:
Document this name change.
compiler/options.m:
Rename the trace option as trace_level internally, since "trace"
is now an operator. The user-visible name remains the same.
Add the new --trace-flag option.
Delete an obsolete option.
compiler/handle_options.m:
Rename the function symbols of the grade_component type,
since "trace" is now an operator.
compiler/llds.m:
Extend the LLDS with a mechanism to refer to C global variables.
For now, these are used to refer to C globals that will be created
by mkinit to represent the initial values of the environment variables
referred to by trace goals.
compiler/commit_gen.m:
Check that no trace goal with a runtime condition survives to code
generation; they should have been transformed by simplify.m.
compiler/code_gen.m:
Tell commit_gen.m what kind of scope it is generating code for.
compiler/pragma_c_gen.m:
Generate code for runtime conditions when handling the foreign_procs
created by simplify.m.
compiler/code_info.m:
Allow pragma_c_gen.m to record what environment variables it has
generated references to.
compiler/proc_gen.m:
Record the set of environment variables a procedure refers to
in the LLDS procedure header, for efficient access by llds_out.m.
compiler/llds_out.m:
Handle the new LLDS construct, and tell mkinit which environment
variables need C globals created for them.
compiler/pd_util.m:
Rename some predicates to avoid ambiguity.
compiler/*.m:
Conform to the changes above, mainly the renames of function symbols
and predicates, the changed signatures of some predicates, and the new
handling of purity.
util/mkinit.c:
Generate the definitions and the initializations of any C globals
representing the initial status (set or not set) of environment
variables needed by trace goals.
library/assoc_list.m:
Add some predicates that are useful in prog_io*.m.
library/term_io.m:
Minor cleanup.
tests/hard_coded/trace_goal_{1,2}.{m,exp}:
New test cases to test the new construct, identical except for whether
the trace goal is enabled at compile time.
tests/hard_coded/trace_goal_env_{1,2}.{m,exp}:
New test cases to test the new construct, identical except for whether
the trace goal is enabled at run time.
tests/hard_coded/Mercury.options:
tests/hard_coded/Mmakefile:
Enable the new test cases.
tests/invalid/*.err_exp:
Update the expected output for the new versions of the error messages
now being generated.
|
||
|
Zoltan Somogyi
|
4fe703c7b9 |
Implement a more cache-friendly translation of lookup switches.
Estimated hours taken: 8
Branches: main
Implement a more cache-friendly translation of lookup switches. Previously,
for a switch such as the one in
:- pred p(foo::in, string::out, bar::out, float::out) is semidet.
p(d, "four", f1, 4.4).
p(e, "five", f2, 5.5).
p(f, "six", f4("hex"), 6.6).
p(g, "seven", f5(77.7), 7.7).
we generated three static cells, one for each argument, and then indexed
into each one in turn to get the values of HeadVar__2, HeadVar__3 and
HeadVar__4. The different static cells each represent a column here.
Each of the loads accessing the columns will access a different cache block,
so with this technique we expect to get as many cache misses as there are
output variables.
This diff changes the code we generate to use a vector of static cells
where each cell represents a row. The assignments to the output variables
will now access the different fields of a row, which will be next to each
other. We thus expect only one cache miss irrespective of the number of output
variables, at least up to the number of variables that actually fit into one
cache block.
compiler/global_data.m:
Provide a mechanism for creating not just single (scalar) static cells,
but arrays (vectors) of them.
compiler/lookup_switch.m:
Use the new mechanism to generate code along the lines described above.
Put the information passed between the two halves of the lookup switch
implementation (detection and code generation) into an opaque data
structure.
compiler/switch_gen.m:
Conform to the new interface of lookup_switch.m.
compiler/ll_pseudo_type_info.m:
compiler/stack_layout.m:
compiler/string_switch.m:
compiler/unify_gen.m:
compiler/var_locn.m:
Conform to the change to global_data.m.
compiler/llds.m:
Define the data structures for holding vectors of static cells. Rename
the function symbols we used to use to refer to static cells to make
clear that they apply to scalar cells only. Provide similar mechanisms
for representing static cell vectors and references to them.
Generalize heap_ref heap references to allow the index to be computed
at runtime, not compile time. For symmetry's sake, do likewise
for stack references.
compiler/llds_out.m:
Add the code required to write out static cell vectors.
Rename decl_ids to increase clarity and avoid ambiguity.
compiler/code_util.m:
compiler/exprn_aux.m:
Modify code that traverses rvals to now also traverse the new rvals
inside memory references.
compiler/name_mangle.m:
Provide the prefix for static cell vectors.
compiler/layout_out.m:
compiler/rtti_out.m:
compiler/opt_debug.m:
Conform to the change to data_addrs and decl_ids.
compiler/code_info.m:
Provide access to the new functionality in global_data.m, and conform
to the change to llds.m.
Provide a utility predicate needed by lookup_switch.m.
compiler/hlds_llds.m:
Fix the formatting of some comments.
tools/binary:
tools/binary_step:
Fix the bit rot that has set in since they were last used (the rest
of the system has changed quite a lot since then). I had to do so
to debug one part of this change.
tests/hard_coded/dense_lookup_switch2.{m,exp}:
tests/hard_coded/dense_lookup_switch3.{m,exp}:
New test cases to exercise the new algorithm.
tests/hard_coded/Mmakefile:
Enable the new test cases, as well as an old one (from 1997!)
that seems never to have been enabled.
|
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|
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. |
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|
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. |
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|
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. |
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|
Zoltan Somogyi
|
21685c9e22 |
Improve the error messages generated for determinism errors involving committed
Estimated hours taken: 6
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.
|
||
|
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.
|
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|
Zoltan Somogyi
|
b2012c0c0e |
Rename the types 'type', 'inst' and 'mode' to 'mer_type', 'mer_inst'
Estimated hours taken: 8 Branches: main compiler/*.m: Rename the types 'type', 'inst' and 'mode' to 'mer_type', 'mer_inst' and 'mer_mode'. This is to avoid the need to parenthesize these type names in some contexts, and to prepare for the possibility of a parser that considers those words to be reserved words. Rename some other uses of those names (e.g. as item types in recompilation.m). Delete some redundant synonyms (prog_type, mercury_type) for mer_type. Change some type names (e.g. mlds__type) and predicate names (e.g. deforest__goal) to make them unique even without module qualification. Rename the function symbols (e.g. pure, &) that need to be renamed to avoid the need to parenthesize them. Make their replacement names more expressive. Convert some more modules to four space indentation. Avoid excessively long lines, such as those resulting from the automatic substitution of 'mer_type' for 'type'. |
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|
Zoltan Somogyi
|
905e4a114f |
Convert a bunch of modules to four-space indentation.
Estimated hours taken: 4 Branches: main compiler/*.m: Convert a bunch of modules to four-space indentation. In the process, fix departures from our coding standards. In some cases, do minor other cleanups such as changing argument orders to be friendly to state variables. There are no algorithmic changes. |
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|
Zoltan Somogyi
|
3c60c0e485 |
Change a bunch of modules to import only one module per line, even
Estimated hours taken: 4 Branches: main compiler/*.m: Change a bunch of modules to import only one module per line, even from the library. compiler/mlds_to_il.m: compiler/mlds_to_managed.m: Convert these modules to our current coding style. Use state variables where appropriate. Use predmode declarations where possible. |
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|
Zoltan Somogyi
|
5d6fd3bd6f |
Reduce the dependence of earlier parts of the compiler on the later ones.
Estimated hours taken: 4 Branches: main Reduce the dependence of earlier parts of the compiler on the later ones. Unnecessary import_module declarations in top level modules such as hlds.m cause unnecessary recompilations when adding new types in later modules, such as submodules of ll_backend.m. This change reduces the number of such unnecessary imports. There are no changes in algorithms, only functionality being moved around. compiler/code_model.m: Change this module from being a submodule of backend_libs.m to being a submodule of hlds.m, since nothing in it is dependent on any backend. compiler/arg_info.m: compiler/code_util.m: Change arg_info.m from being a submodule of ll_backend.m to being a submodule of hlds.m, since most of it is applicable to all current and foreseeable backends. Move the one exported predicate that is ll_backend dependent, and its support predicates, to code_util.m. compiler/backend_libs.m: compiler/ll_backend.m: compiler/hlds.m: Update include_module declarations in accordance with the above. compiler/prog_data.m: compiler/term_util.m: Instead of defining two separate types for holding argument size and termination information, one including HLDS-specific information (in term_util.m) and one not (in prog_data.m), use a polymorphic type defined in prog_data.m and two monomorphic instances. compiler/termination.m: compiler/mercury_to_mercury.m: Change the predicates for writing out argument size and termination information to handle the polymorphic type (we don't need special handling of the monomorphic versions), and move them from termination.m to mercury_to_mercury.m, since this allows us to avoid some undesirable dependencies. compiler/base_typeclass_info.m: compiler/hlds_code_util.m: Move the predicate make_instance_string from base_typeclass_info.m to hlds_code_util.m, again because it allows us to remove some undesirable dependencies. compiler/top_level.m: compiler/backend_libs.m: compiler/check_hlds.m: compiler/hlds.m: compiler/ll_backend.m: compiler/parse_tree.m: compiler/transform_hlds.m: Delete some import_module declarations of other top level modules in these top level modules. Some imports were totally unnecessary. Some imports were useful in only a small minority of submodules; those submodules now import the necessary top level modules directly. Move remaining import_module declarations to the implementation section where this is feasible. Where we still need to import modules we ideally shouldn't, note why. compiler/*.m: Update imports of code_util and arg_info. In some cases, import top level modules no longer imported by the parent module. In some cases, delete unnecessary imports. |
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|
Zoltan Somogyi
|
c8e4004825 |
This diff makes code_info.m and many callers of its predicates easier to read
Estimated hours taken: 4 Branches: main This diff makes code_info.m and many callers of its predicates easier to read and to maintain, but contains no changes in algorithms whatsoever. compiler/code_info.m: Bring this module into line with our current coding standards. Use predmode declarations, functions, and state variable syntax when appropriate. Reorder arguments of predicates where necessary for the use of state variable syntax, and where this improves readability. Where a predicate returned its input code_info unchanged, purely to allow the convenient use of DCG notation in the caller, delete the unnecessary output argument. This should make the caller somewhat more efficient, since it can avoid updating the stack slot holding the current code_info. Replace old-style lambdas with new-style lambdas or with partially applied named procedures. compiler/*.m: Conform to the changes in code_info.m. This mostly means using the new argument orders of predicates exported by hlds_pred.m, and using state variable notation. |
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|
Zoltan Somogyi
|
f007b45df8 |
Implement the infrastructure for term size profiling.
Estimated hours taken: 400
Branches: main
Implement the infrastructure for term size profiling. This means adding two
new grade components, tsw and tsc, and implementing them in the LLDS code
generator. In grades including tsw (term size words), each term is augmented
with an extra word giving the number of heap words it contains; in grades
including tsc (term size cells), each term is augmented with an extra word
giving the number of heap cells it contains. The extra word is at the start,
at offset -1, to leave almost all of the machinery for accessing the heap
unchanged.
For now, the only way to access term sizes is with a new mdb command,
"term_size <varspec>". Later, we will use term sizes in conjunction with
deep profiling to do experimental complexity analysis, but that requires
a lot more research. This diff is a necessary first step.
The implementation of term size profiling consists of three main parts:
- a source-to-source transform that computes the size of each heap cell
when it is constructed (and increments it in the rare cases when a free
argument of an existing heap cell is bound),
- a relatively small change to the code generator that reserves the extra
slot in new heap cells, and
- extensions to the facilities for creating cells from C code to record
the extra information we now need.
The diff overhauls polymorphism.m to make the source-to-source transform
possible. This overhaul includes separating type_ctor_infos and type_infos
as strictly as possible from each other, converting type_ctor_infos into
type_infos only as necessary. It also includes separating type_ctor_infos,
type_infos, base_typeclass_infos and typeclass_infos (as well as voids,
for clarity) from plain user-defined type constructors in type categorizations.
This change needs this separation because values of those four types do not
have size slots, but they ought to be treated specially in other situations
as well (e.g. by tabling).
The diff adds a new mdb command, term_size. It also replaces the proc_body
mdb command with new ways of using the existing print and browse commands
("print proc_body" and "browse proc_body") in order to make looking at
procedure bodies more controllable. This was useful in debugging the effect
of term size profiling on some test case outputs. It is not strictly tied
to term size profiling, but turns out to be difficult to disentangle.
compiler/size_prof.m:
A new module implementing the source-to-source transform.
compiler/notes/compiler_design.html:
Mention the new module.
compiler/transform_hlds.m:
Include size_prof as a submodule of transform_hlds.
compiler/mercury_compile.m:
If term size profiling is enabled, invoke its source-to-source
transform.
compiler/hlds_goal.m:
Extend construction unifications with an optional slot for recording
the size of the term if the size is a constant, or the identity of the
variable holding the size, if the size is not constant. This is
needed by the source-to-source transform.
compiler/quantification.m:
Treat the variable reference that may be in this slot as a nonlocal
variable of construction unifications, since the code generator needs
this.
compiler/compile_target_code.m:
Handle the new grade components.
compiler/options.m:
Implement the options that control term size profiling.
doc/user_guide.texi:
Document the options and grade components that control term size
profiling, and the term_size mdb command. The documentation is
commented out for now.
Modify the wording of the 'u' HLDS dump flag to include other details
of unifications (e.g. term size info) rather than just unification
categories.
Document the new alternatives of the print and browse commands. Since
they are for developers only, the documentation is commented out.
compiler/handle_options.m:
Handle the implications of term size profiling grades.
Add a -D flag value to print HLDS components relevant to HLDS
transformations.
compiler/modules.m:
Import the new builtin library module that implements the operations
needed by term size profiling automatically in term size profiling
grades.
Switch the predicate involved to use state var syntax.
compiler/prog_util.m:
Add predicates and functions that return the sym_names of the modules
needed by term size profiling.
compiler/code_info.m:
compiler/unify_gen.m:
compiler/var_locn.m:
Reserve an extra slot in heap cells and fill them in in unifications
marked by size_prof.
compiler/builtin_ops.m:
Add term_size_prof_builtin.term_size_plus as a builtin, with the same
implementation as int.+.
compiler/make_hlds.m:
Disable warnings about clauses for builtins while the change to
builtin_ops is bootstrapped.
compiler/polymorphism.m:
Export predicates that generate goals to create type_infos and
type_ctor_infos to add_to_construct.m. Rewrite their documentation
to make it more detailed.
Make orders of arguments amenable to the use of state variable syntax.
Consolidate knowledge of which type categories have builtin unify and
compare predicates in one place.
Add code to leave the types of type_ctor_infos alone: instead of
changing their types to type_info when used as arguments of other
type_infos, create a new variable of type type_info instead, and
use an unsafe_cast. This would make the HLDS closer to being type
correct, but this new code is currently commented out, for two
reasons. First, common.m is currently not smart enough to figure out
that if X and Y are equal, then similar unsafe_casts of X and Y
are also equal, and this causes the compiler do not detect some
duplicate calls it used to detect. Second, the code generators
are also not smart enough to know that if Z is an unsafe_cast of X,
then X and Z do not need separate stack slots, but can use the same
slot.
compiler/type_util.m:
Add utility predicates for returning the types of type_infos and
type_ctor_infos, for use by new code in polymorphism.m.
Move some utility predicates here from other modules, since they
are now used by more than one module.
Rename the type `builtin_type' as `type_category', to better reflect
what it does. Extend it to put the type_info, type_ctor_info,
typeclass_info, base_typeclass_info and void types into categories
of their own: treating these types as if they were a user-defined
type (which is how they used to be classified) is not always correct.
Rename the functor polymorphic_type to variable_type, since types
such as list(T) are polymorphic, but they fall into the user-defined
category. Rename user_type as user_ctor_type, since list(int) is not
wholly user-defined but falls into this category. Rename pred_type
as higher_order_type, since it also encompasses functions.
Replace code that used to check for a few of the alternatives
of this type with code that does a full switch on the type,
to ensure that they are updated if the type definition ever
changes again.
compiler/pseudo_type_info.m:
Delete a predicate whose updated implementation is now in type_util.m.
compiler/mlds_to_c.m:
compiler/mlds_to_gcc.m:
compiler/mlds_to_il.m:
compiler/mlds_to_java.m:
Still treat type_infos, type_ctor_infos, typeclass_infos and
base_typeclass_infos as user-defined types, but prepare for when
they won't be.
compiler/hlds_pred.m:
Require interface typeinfo liveness when term size profiling is
enabled.
Add term_size_profiling_builtin.increase_size as a
no_type_info_builtin.
compiler/hlds_out.m:
Print the size annotations on unifications if HLDS dump flags call
for unification details. (The flag test is in the caller of the
modified predicate.)
compiler/llds.m:
Extend incr_hp instructions and data_addr_consts with optional fields
that allow the code generator to refer to N words past the start of
a static or dynamic cell. Term size profiling uses this with N=1.
compiler/llds_out.m:
When allocating memory on the heap, use the macro variants that
specify an optional offset, and specify the offset when required.
compiler/bytecode_gen.m:
compiler/dense_switch.m:
compiler/dupelim.m:
compiler/exprn_aux.m:
compiler/goal_form.m:
compiler/goal_util.m:
compiler/higher_order.m:
compiler/inst_match.m:
compiler/intermod.m:
compiler/jumpopt.m:
compiler/lambda.m:
compiler/livemap.m:
compiler/ll_pseudo_type_info.m:
compiler/lookup_switch.m:
compiler/magic_util.m:
compiler/middle_rec.m:
compiler/ml_code_util.m:
compiler/ml_switch_gen.m:
compiler/ml_unify_gen.m:
compiler/mlds.m:
compiler/mlds_to_c.m:
compiler/mlds_to_gcc.m:
compiler/mlds_to_il.m:
compiler/mlds_to_java.m:
compiler/modecheck_unify.m:
compiler/opt_debug.m:
compiler/opt_util.m:
compiler/par_conj_gen.m:
compiler/post_typecheck.m:
compiler/reassign.m:
compiler/rl.m:
compiler/rl_key.m:
compiler/special_pred.m:
compiler/stack_layout.m:
compiler/static_term.m:
compiler/string_switch.m:
compiler/switch_gen.m:
compiler/switch_util.m:
compiler/table_gen.m:
compiler/term_util.m:
compiler/type_ctor_info.m:
compiler/unused_args.m:
compiler/use_local_vars.m:
Minor updates to conform to the changes above.
library/term_size_prof_builtin.m:
New module containing helper predicates for term size profiling.
size_prof.m generates call to these predicates.
library/library.m:
Include the new module in the library.
doc/Mmakefile:
Do not include the term_size_prof_builtin module in the library
documentation.
library/array.m:
library/benchmarking.m:
library/construct.m:
library/deconstruct.m:
library/io.m:
library/sparse_bitset.m:
library/store.m:
library/string.m:
Replace all uses of MR_incr_hp with MR_offset_incr_hp, to ensure
that we haven't overlooked any places where offsets may need to be
specified.
Fix formatting of foreign_procs.
Use new macros defined by the runtime system when constructing
terms (which all happen to be lists) in C code. These new macros
specify the types of the cell arguments, allowing the implementation
to figure out the size of the new cell based on the sizes of its
fields.
library/private_builtin.m:
Define some constant type_info structures for use by these macros.
They cannot be defined in the runtime, since they refer to types
defined in the library (list.list and std_util.univ).
util/mkinit.c:
Make the addresses of these type_info structures available to the
runtime.
runtime/mercury_init.h:
Declare these type_info structures, for use in mkinit-generated
*_init.c files.
runtime/mercury_wrapper.[ch]:
Declare and define the variables that hold these addresses, for use
in the new macros for constructing typed lists.
Since term size profiling can refer to a memory cell by a pointer
that is offset by one word, register the extra offsets with the Boehm
collector if is being used.
Document the incompatibility of MR_HIGHTAGS and the Boehm collector.
runtime/mercury_tags.h:
Define new macros for constructing typed lists.
Provide macros for preserving the old interface presented by this file
to the extent possible. Uses of the old MR_list_cons macro will
continue to work in grades without term size profiling. In term
size profiling grades, their use will get a C compiler error.
Fix a bug caused by a missing backslash.
runtime/mercury_heap.h:
Change the basic macros for allocating new heap cells to take
an optional offset argument. If this is nonzero, the macros
increment the returned address by the given number of words.
Term size profiling specifies offset=1, reserving the extra
word at the start (which is ignored by all components of the
system except term size profiling) for holding the size of the term.
Provide macros for preserving the old interface presented by this file
to the extent possible. Since the old MR_create[123] and MR_list_cons
macros did not specify type information, they had to be changed
to take additional arguments. This affects only hand-written C code.
Call new diagnostic macros that can help debug heap allocations.
Document why the macros in this files must expand to expressions
instead of statements, evn though the latter would be preferable
(e.g. by allowing them to declare and use local variables without
depending on gcc extensions).
runtime/mercury_debug.[ch]:
Add diagnostic macros to debug heap allocations, and the functions
behind them if MR_DEBUG_HEAP_ALLOC is defined.
Update the debugging routines for hand-allocated cells to print the
values of the term size slot as well as the other slots in the relevant
grades.
runtime/mercury_string.h:
Provide some needed variants of the macro for copying strings.
runtime/mercury_deconstruct_macros.h:
runtime/mercury_type_info.c:
Supply type information when constructing terms.
runtime/mercury_deep_copy_body.h:
Preserve the term size slot when copying terms.
runtime/mercury_deep_copy_body.h:
runtime/mercury_ho_call.c:
runtime/mercury_ml_expand_body.h:
Use MR_offset_incr_hp instead of MR_incr_hp to ensure that all places
that allocate cells also allocate space for the term size slot if
necessary.
Reduce code duplication by using a now standard macro for copying
strings.
runtime/mercury_grade.h:
Handle the two new grade components.
runtime/mercury_conf_param.h:
Document the C macros used to control the two new grade components,
as well as MR_DEBUG_HEAP_ALLOC.
Detect incompatibilities between high level code and profiling.
runtime/mercury_term_size.[ch]:
A new module to house a function to find and return term sizes
stored in heap cells.
runtime/mercury_proc_id.h:
runtime/mercury_univ.h:
New header files. mercury_proc_id.h contains the (unchanged)
definition of MR_Proc_Id, while mercury_univ.h contains the
definitions of the macros for manipulating univs that used to be
in mercury_type_info.h, updated to use the new macros for allocating
memory.
In the absence of these header files, the following circularity
would ensue:
mercury_deep_profiling.h includes mercury_stack_layout.h
- needs definition of MR_Proc_Id
mercury_stack_layout.h needs mercury_type_info.h
- needs definition of MR_PseudoTypeInfo
mercury_type_info.h needs mercury_heap.h
- needs heap allocation macros for MR_new_univ_on_hp
mercury_heap.h includes mercury_deep_profiling.h
- needs MR_current_call_site_dynamic for recording allocations
Breaking the circular dependency in two places, not just one, is to
minimize similar problems in the future.
runtime/mercury_stack_layout.h:
Delete the definition of MR_Proc_Id, which is now in mercury_proc_id.h.
runtime/mercury_type_info.h:
Delete the macros for manipulating univs, which are now in
mercury_univ.h.
runtime/Mmakefile:
Mention the new files.
runtime/mercury_imp.h:
runtime/mercury.h:
runtime/mercury_construct.c:
runtime/mercury_deep_profiling.h:
Include the new files at appropriate points.
runtime/mercury.c:
Change the names of the functions that create heap cells for
hand-written code, since the interface to hand-written code has
changed to include type information.
runtime/mercury_tabling.h:
Delete some unused macros.
runtime/mercury_trace_base.c:
runtime/mercury_type_info.c:
Use the new macros supplying type information when constructing lists.
scripts/canonical_grade_options.sh-subr:
Fix an undefined sh variable bug that could cause error messages
to come out without identifying the program they were from.
scripts/init_grade_options.sh-subr:
scripts/parse_grade_options.sh-subr:
scripts/canonical_grade_options.sh-subr:
scripts/mgnuc.in:
Handle the new grade components and the options controlling them.
trace/mercury_trace_internal.c:
Implement the mdb command "term_size <varspec>", which is like
"print <varspec>", but prints the size of a term instead of its value.
In non-term-size-profiling grades, it prints an error message.
Replace the "proc_body" command with optional arguments to the "print"
and "browse" commands.
doc/user_guide.tex:
Add documentation of the term_size mdb command. Since the command is
for implementors only, and works only in grades that are not yet ready
for public consumption, the documentation is commented out.
Add documentation of the new arguments of the print and browse mdb
commands. Since they are for implementors only, the documentation
is commented out.
trace/mercury_trace_vars.[ch]:
Add the functions needed to implement the term_size command, and
factor out the code common to the "size" and "print"/"browse" commands.
Decide whether to print the name of a variable before invoking the
supplied print or browse predicate on it based on a flag design for
this purpose, instead of overloading the meaning of the output FILE *
variable. This arrangement is much clearer.
trace/mercury_trace_browse.c:
trace/mercury_trace_external.c:
trace/mercury_trace_help.c:
Supply type information when constructing terms.
browser/program_representation.m:
Since the new library module term_size_prof_builtin never generates
any events, mark it as such, so that the declarative debugger doesn't
expect it to generate any.
Do the same for the deep profiling builtin module.
tests/debugger/term_size_words.{m,inp,exp}:
tests/debugger/term_size_cells.{m,inp,exp}:
Two new test cases, each testing one of the new grades.
tests/debugger/Mmakefile:
Enable the two new test cases in their grades.
Disable the tests sensitive to stack frame sizes in term size profiling
grades.
tests/debugger/completion.exp:
Add the new "term_size" mdb command to the list of command completions,
and delete "proc_body".
tests/debugger/declarative/dependency.{inp,exp}:
Use "print proc_body" instead of "proc_body".
tests/hard_coded/nondet_c.m:
tests/hard_coded/pragma_inline.m:
Use MR_offset_incr_hp instead of MR_incr_hp to ensure that all places
that allocate cells also allocate space for the term size slot if
necessary.
tests/valid/Mmakefile:
Disable the IL tests in term size profiling grades, since the term size
profiling primitives haven't been (and probably won't be) implemented
for the MLDS backends, and handle_options causes a compiler abort
for grades that combine term size profiling and any one of IL, Java
and high level C.
|
||
|
Zoltan Somogyi
|
92045bdc78 |
Simplify the handling of static ground terms in the LLDS backend.
Estimated hours taken: 5 Branches: main Simplify the handling of static ground terms in the LLDS backend. Instead of creating code, rtti and layout structures all containing create rvals and then converting those rvals to static cells, create the static cells directly. compiler/llds.m: Remove the create alternative from rvals, and the types used only by create. Delete the code handling the global_data type, which has been moved to global_data.m. compiler/global_data.m: A new module handling static data structures for the LLDS backend. The basis of this module is the code that used to be in llds.m handling the global_data type, but this has been augmented to manage static cells as well as the data structures defined in rtti.m and layout.m. Also, rename the non_common_data field of global_data, which no longer makes sense, to refer to deep profiling, since it holds deep profiling data structures. compiler/llds_common.m: Delete this file, since it is no longer needed. The operative part is now in global data.m; the rest (including the code to traverse code and data structures looking for create rvals) is no longer needed. compiler/ll_backend.m: Delete the deleted module, and add the added module. XXX These changes should be also be documented in notes/compiler_design.html when Fergus finishes his changes to that file. compiler/code_info.m: Add the database of static cells to the code generator state. compiler/code_gen.m: compiler/ll_pseudo_type_info.m: compiler/lookup_switch.m: compiler/mercury_compile.m: compiler/stack_layout.m: compiler/static_term.m: compiler/string_switch.m: compiler/unify_gen.m: compiler/var_locn.m: Instead of creating create rvals, create static cells and return references to those cells. The static cell database ensures that we never create duplicate cells (unless --no-common-data forces us to do so). Pass around the static cell database. compiler/code_util.m: compiler/continuation_info.m: compiler/dupelim.m: compiler/exprn_aux.m: compiler/jumpopt.m: compiler/livemap.m: compiler/llds_out.m: compiler/middle_rec.m: compiler/opt_debug.m: compiler/opt_util.m: compiler/optimize.m: Minor changes to conform to the above, mostly consisting of the deletion of code that handled create rvals. |
||
|
Zoltan Somogyi
|
9b0aa613c4 |
Delete the cell number field from create rvals, since we don't need
Estimated hours taken: 1 Branches: main compiler/llds.m: Delete the cell number field from create rvals, since we don't need it anymore. compiler/*.m: Conform to the change above, and simplify predicate interfaces by deleting arguments whose sole purpose was the allocation of cell numbers. |
||
|
Zoltan Somogyi
|
9551640f55 |
Import only one compiler module per line. Sort the blocks of imports.
Estimated hours taken: 2 Branches: main compiler/*.m: Import only one compiler module per line. Sort the blocks of imports. This makes it easier to merge in changes. In a couple of places, remove unnecessary imports. |
||
|
Zoltan Somogyi
|
d869c5505b |
Hide the events associated with the goals inserted by tabling transformations,
Estimated hours taken: 2 Branches: main Hide the events associated with the goals inserted by tabling transformations, since ordinary programmers shouldn't be exposed to the details of the transformation. (A later diff will adjust the goal paths of the events associated with the original code back to what they would have been without the transformation.) Add a new mdb command, unhide_events, that allows the programmer to expose hidden events. This is intended for implementors only. compiler/hlds_goal.m: Add a new goal feature, hide_debug_event. If a nonatomic goal has this feature, then the associated trace events will be hidden. compiler/trace.m: Respect the new goal feature. compiler/table_gen.m: Add the new goal feature to the compound goals created by tabling transformations. compiler/code_gen.m: compiler/dense_switch.m: compiler/disj_gen.m: compiler/ite_gen.m: compiler/string_switch.m: compiler/switch_gen.m: compiler/tag_switch.m: Pass the required goal_info to trace.m, to allow it to hide events as required. runtime/mercury_trace_base.[ch]: Add two global boolean variables. One says whether we are exposing hidden events, the other says whether we have ever exposed hidden events. trace/mercury_trace.c: Hide hidden events, unless the programmer has asked for them to be exposed. trace/mercury_trace_internal.c: Implement the unhide_events command. Make "dd" check whether we have ever exposed hidden events. Fix some unclear code in "print_optionals". doc/user_guide.texi: Doument the unhide_events command. doc/mdb_categories: Mention the unhide_events command. tests/debugger/mdb_command_test.inp: Test the documentation of the unhide_events command. |
||
|
Zoltan Somogyi
|
189b9215ae |
This diff implements stack slot optimization for the LLDS back end based on
Estimated hours taken: 400
Branches: main
This diff implements stack slot optimization for the LLDS back end based on
the idea that after a unification such as A = f(B, C, D), saving the
variable A on the stack indirectly also saves the values of B, C and D.
Figuring out what subset of {B,C,D} to access via A and what subset to access
via their own stack slots is a tricky optimization problem. The algorithm we
use to solve it is described in the paper "Using the heap to eliminate stack
accesses" by Zoltan Somogyi and Peter Stuckey, available in ~zs/rep/stackslot.
That paper also describes (and has examples of) the source-to-source
transformation that implements the optimization.
The optimization needs to know what variables are flushed at call sites
and at program points that establish resume points (e.g. entries to
disjunctions and if-then-elses). We already had code to compute this
information in live_vars.m, but this code was being invoked too late.
This diff modifies live_vars.m to allow it to be invoked both by the stack
slot optimization transformation and by the code generator, and allows its
function to be tailored to the requirements of each invocation.
The information computed by live_vars.m is specific to the LLDS back end,
since the MLDS back ends do not (yet) have the same control over stack
frame layout. We therefore store this information in a new back end specific
field in goal_infos. For uniformity, we make all the other existing back end
specific fields in goal_infos, as well as the similarly back end specific
store map field of goal_exprs, subfields of this new field. This happens
to significantly reduce the sizes of goal_infos.
To allow a more meaningful comparison of the gains produced by the new
optimization, do not save any variables across erroneous calls even if
the new optimization is not enabled.
compiler/stack_opt.m:
New module containing the code that performs the transformation
to optimize stack slot usage.
compiler/matching.m:
New module containing an algorithm for maximal matching in bipartite
graphs, specialized for the graphs needed by stack_opt.m.
compiler/mercury_compile.m:
Invoke the new optimization if the options ask for it.
compiler/stack_alloc.m:
New module containing code that is shared between the old,
non-optimizing stack slot allocation system and the new, optimizing
stack slot allocation system, and the code for actually allocating
stack slots in the absence of optimization.
Live_vars.m used to have two tasks: find out what variables need to be
saved on the stack, and allocating those variables to stack slots.
Live_vars.m now does only the first task; stack_alloc.m now does
the second, using code that used to be in live_vars.m.
compiler/trace_params:
Add a new function to test the trace level, which returns yes if we
want to preserve the values of the input headvars.
compiler/notes/compiler_design.html:
Document the new modules (as well as trace_params.m, which wasn't
documented earlier).
compiler/live_vars.m:
Delete the code that is now in stack_alloc.m and graph_colour.m.
Separate out the kinds of stack uses due to nondeterminism: the stack
slots used by nondet calls, and the stack slots used by resumption
points, in order to allow the reuse of stack slots used by resumption
points after execution has left their scope. This should allow the
same stack slots to be used by different variables in the resumption
point at the start of an else branch and nondet calls in the then
branch, since the resumption point of the else branch is not in effect
when the then branch is executed.
If the new option --opt-no-return-calls is set, then say that we do not
need to save any values across erroneous calls.
Use type classes to allow the information generated by this module
to be recorded in the way required by its invoker.
Package up the data structures being passed around readonly into a
single tuple.
compiler/store_alloc.m:
Allow this module to be invoked by stack_opt.m without invoking the
follow_vars transformation, since applying follow_vars before the form
of the HLDS code is otherwise final can be a pessimization.
Make the module_info a part of the record containing the readonly data
passed around during the traversal.
compiler/common.m:
Do not delete or move around unifications created by stack_opt.m.
compiler/call_gen.m:
compiler/code_info.m:
compiler/continuation_info.m:
compiler/var_locn.m:
Allow the code generator to delete its last record of the location
of a value when generating code to make an erroneous call, if the new
--opt-no-return-calls option is set.
compiler/code_gen.m:
Use a more useful algorithm to create the messages/comments that
we put into incr_sp instructions, e.g. by distinguishing between
predicates and functions. This is to allow the new scripts in the
tool directory to gather statistics about the effect of the
optimization on stack frame sizes.
library/exception.m:
Make a hand-written incr_sp follow the new pattern.
compiler/arg_info.m:
Add predicates to figure out the set of input, output and unused
arguments of a procedure in several different circumstances.
Previously, variants of these predicates were repeated in several
places.
compiler/goal_util.m:
Export some previously private utility predicates.
compiler/handle_options.m:
Turn off stack slot optimizations when debugging, unless
--trace-optimized is set.
Add a new dump format useful for debugging --optimize-saved-vars.
compiler/hlds_llds.m:
New module for handling all the stuff specific to the LLDS back end
in HLDS goal_infos.
compiler/hlds_goal.m:
Move all the relevant stuff into the new back end specific field
in goal_infos.
compiler/notes/allocation.html:
Update the documentation of store maps to reflect their movement
into a subfield of goal_infos.
compiler/*.m:
Minor changes to accomodate the placement of all back end specific
information about goals from goal_exprs and individual fields of
goal_infos into a new field in goal_infos that gathers together
all back end specific information.
compiler/use_local_vars.m:
Look for sequences in which several instructions use a fake register
or stack slot as a base register pointing to a cell, and make those
instructions use a local variable instead.
Without this, a key assumption of the stack slot optimization,
that accessing a field in a cell costs only one load or store
instruction, would be much less likely to be true. (With this
optimization, the assumption will be false only if the C compiler's
code generator runs out of registers in a basic block, which for
the code we generate should be unlikely even on x86s.)
compiler/options.m:
Make the old option --optimize-saved-vars ask for both the old stack
slot optimization (implemented by saved_vars.m) that only eliminates
the storing of constants in stack slots, and the new optimization.
Add two new options --optimize-saved-vars-{const,cell} to turn on
the two optimizations separately.
Add a bunch of options to specify the parameters of the new
optimizations, both in stack_opt.m and use_local_vars.m. These are
for implementors only; they are deliberately not documented.
Add a new option, --opt-no-return-cells, that governs whether we avoid
saving variables on the stack at calls that cannot return, either by
succeeding or by failing. This is for implementors only, and thus
deliberately documented only in comments. It is enabled by default.
compiler/optimize.m:
Transmit the value of a new option to use_local_vars.m.
doc/user_guide.texi:
Update the documentation of --optimize-saved-vars.
library/tree234.m:
Undo a previous change of mine that effectively applied this
optimization by hand. That change complicated the code, and now
the compiler can do the optimization automatically.
tools/extract_incr_sp:
A new script for extracting stack frame sizes and messages from
stack increment operations in the C code for LLDS grades.
tools/frame_sizes:
A new script that uses extract_incr_sp to extract information about
stack frame sizes from the C files saved from a stage 2 directory
by makebatch and summarizes the resulting information.
tools/avg_frame_size:
A new script that computes average stack frame sizes from the files
created by frame_sizes.
tools/compare_frame_sizes:
A new script that compares the stack frame size information
extracted from two different stage 2 directories by frame_sizes,
reporting on both average stack frame sizes and on specific procedures
that have different stack frame sizes in the two versions.
|