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10 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Zoltan Somogyi
|
7c296404bb |
Add "Opt level N automatically sets --xyz" ...
... to the user guide entries of the affected optimization options.
compiler/print_help.m:
Implement the above.
doc/user_guide.texi:
Expect the additions, both from this diff, and earlier ones.
tools/make_optimization_options_middle:
compiler/optimization_options.m:
To make the above slightly simpler to implement, add a subtype
of the option_data type, and change the type of the predicate
that returns the options enabled at each optimization level
to use this subtype.
configure.ac:
Require the installed compiler to support the fix without which
the subtype definition would make the automatically-generated
contents of libs.optimization_options.int2 invalid.
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||
|
Zoltan Somogyi
|
51b1304b0d |
Record the initial values of the bool_special options ...
... which are managed by tools/make_optimization_options.
tools/make_optimization_options_middle:
When creating compiler/optimization_options.m, put into it
a new predicate that records, for each bool_special option
managed by this module, its initial value.
compiler/print_help.m:
Handle bool_special options whose initial value this new predicate
makes known the same way we now handle plain bool options.
The difference this makes is that bool_special options that
default to "yes" will now have their --no-xyz form listed as
the user-visible form of the option, not their --xyz form.
tools/make_optimization_options_db:
tools/make_optimization_options_end:
Fix a discrepancy that made documenting the smart indexing
unnecessarily complicated. The first such option defaulted to "no",
but was switched to "yes" at -O0, while the others all defaulted
to "yes". Allow these options to be documented in the same manner
by making them *all* default to "no", and switch them all on at -O0.
compiler/optimization_options.m:
Rebuilt with the updated make_optimization_options.
compiler/options.m:
Many of the bool_special options that default to "yes" had
help text that already assumed that this text followed
the option name being printed as --no-xyz.
For the others, which assumed that they followed --xyz,
change the help text to be appropriate when following
the --no-xyz form.
tests/warnings/help_text.err_exp:
Expect the updated help texts.
doc/user_guide.texi:
Expect the updated help texts, from this and earlier commits.
tests/warnings/help_opt_level.err_exp:
Expect the added level-enabled options.
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|
Zoltan Somogyi
|
96022cee60 |
Prepare to document optimization levels ...
... by having the automatically-generated optimization_options.m module
export the information we will need for that documentation.
tools/make_optimization_options_end:
Modify the predicate that lists the options at each optimization level
in two distinct ways:
- by turning the existing comments documenting the meaning of each
optimization level into strings that we can include the documentation,
and
- by adding next to each optimization_option setting, which cannot be
easily turned into the user-facing names of the options being set,
the option and its new value, which can be turned into that.
There was another possible way to get the second job done. This was
to have tools/make_optimization_options_middle generate TWO versions
of the code that is now bodily included in options.m between
INCLUDE_HANDLER_FILE_{START,END}: the one we have there now,
and one that can do the conversion in the reverse direction.
I judged this extra 500+ lines of code to be too much, even if
automatically generated.
(Putting the code as the body of a predicate with two modes would work,
but this would separate the parts of switch on Option inside the
special_handler that are automatically generated from the parts
which are hand-written, and would therefore allow any accidental
duplicate arms (options handled in both parts) to be undetected.
I judged this to be unacceptable also.)
The method I chose does duplicate some code (each level lists the
same info in two different ways), but since the consistency is trivial
to check visually, and we update levels so rarely, this should not matter.
tools/make_optimization_options_middle:
tools/make_optimization_options_start:
Conform to the changes above.
tools/make_optimization_options_db:
compiler/options.m:
Rename the optopt_everything_in_one_c_function option to the name
it has inside optimization_options.m, optopt_use_just_one_c_func.
Since this did not break anything, move the option to the
oc_unused category.
compiler/optimization_options.m:
Automatic update after the changes in tools/make_optimization_options*.
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||
|
Zoltan Somogyi
|
88d4bccdba |
Add new optimization option --split-switch-arms.
Given a switch arm that matches several cons_ids, and which contains
one or more switches on the *same* variable, such as the arm for
f1/f2/f3/f4 below,
(
(X = f1 ; X = f2 ; X = f3 ; X = f4),
...
(
X = f1,
...
;
(X = f2 ; X = f3),
...
;
X = f4,
...
),
...
;
...
)
this new optimization
- partitions the set of cons_id in that arm (in this case, {f1,f2,f3,f4})
as finely as needed by any other the switches on X in that arm
(in this case, that is three partitions containing {f1}, {f2,f3} and {f4}),
- splits that original switch arm into N arms, one arm for each partition,
making a copy of the switch arm's goal for each partition,
- restricts any switches on the original switch variable (in this case, X)
inside the copy of the arm goal inside each new case to only the cons_ids
in that case's partition, and then replacing any resulting one-arm switches
with the just goal inside that one arm.
The code resulting from these three steps will include some code duplication
(some of the pieces of code denoted by ... in the example above would be
duplicated), but it will need to execute fewer transfers of control.
This is worthwhile because (a) the branch instructions used to implement
switches are hard to predict unless most paths through the nested switches
are rarely if ever taken, and (b) the pipeline breaks caused by branches
that are not correctly predicted are one of the two major contributors
to the runtime of Mercury programs. (The other major contributors are
data cache misses.)
The implementation of this option has two major parts.
- Part 1 consists of discovering whether a procedure body contains
any code in which a switch on a variable is nested inside an arm
of another switch on that same variable. For any instance of such
a pair of switches, it records the identity of the variable and
the set of cons_ids of the outermost arm.
- Part 2 consists of actually transforming the procedure body
by splitting each outermost switch arm thus recorded. (This part
contains all three of the steps above.)
We integrate part 1 with the usual procedure body traversal of the
simplification pass, which makes it quite cheap. In most procedure bodies,
it won't find any nested switches meeting its criteria. We execute part 2,
which is relatively expensive, only if it does.
compiler/simplify_info.m:
Add a new type, switch_arm, which represents one arm of a switch.
Add a new field to the simplify_nested_context type. Its type
is list(switch_arm), and it represents the stack of switch arms (if any)
that the goal currently being simplified is inside. simplify_goal_switch.m
uses this field to detect switches that occur inside an arm of an
ancestor goal that is also a switch on the same variable.
Add a new field to the simplify_info, a set of switch_arms,
that denotes the set of switch arms from which that detection
has actually happened, and which should therefore be
partitioned and split.
compiler/simplify_goal_switch.m:
Add the code for doing the detection and recording mentioned just above.
This is the Part 1 mentioned above.
compiler/split_switch_arms.m:
This new module implements the splitting up process.
This is the Part 2 mentioned above.
compiler/simplify.m:
Include the new module in the simplify subpackage of the check_hlds
package.
compiler/notes/compiler_design.html:
Document the new module.
compiler/simplify_proc.m:
Invoke split_switch_arms.m (part 2) if the part of simplify_goal_switch.m
implementing part 1 has found any work for it to do.
compiler/simplify_tasks.m:
Add split_switch_arms as one of the tasks that simplification
may be asked to do. Set its default value from the value of
a new optimization option that, when specified, calls for it to be done.
compiler/options.m:
Add this option, --split-switch-arms.
Change the internal name of an existing option,
everything_in_one_c_function, to the one expected by
tools/make_optimization_options_middle.
Replace the part of this file that is constructed by
tools/make_optimization_options_middle.
doc/user_guide.texi:
Document the new option.
tools/make_optimization_options_db:
Add --split-switch-arms to the optimization tuple.
Fix software rot by
- renaming optimize_tailcalls to optimize_mlds_tailcalls inside the
optimization tuple, as it has been in options.m, and
- deleting erlang_switch_on_strings_as_atoms from the opt_tuple,
as it has been from options.m.
tools/make_optimization_options_end:
Enable the new option by default at optimization level 2.
tools/make_optimization_options_middle:
Fix bugs in this script, which generates compiler/optimization_options.m.
One bug was that it referred to the opt_level and opt_space options
by the wrong name (optopt_level and optopt_space respectively).
The other bug was that it expected opt_level to be a string_special option,
when it is an int_special option.
Make the handler_file this script generates easier to put into options.m
by not generating a line that (a) already exists in options.m, and
(b) would need to have a comma put after it, if one wanted this line
to replace the copy already in options.m.
compiler/optimization_options.m:
Rebuild this file after the changes above.
compiler/simplify_goal_unify.m:
Conform to the changes above.
compiler/inst_merge.m:
Mark two predicates, inst_merge_[34], to be inlined. The intention
is that inst_merge_4 should be inlined into inst_merge_3, and then
inst_merge_3 should be inlined inside inst_merge_2; that would then
generate six levels of switches, three on one of the insts to be
merged and three on the other, which the new optimization could
then flatten. Unfortunately, inlining does not do this yet.
tests/hard_coded/test_split_switch_arms.{m,exp}:
A new test case for the the new transformation.
tests/hard_coded/Mmakefile:
tests/hard_coded/Mercury.options:
Enable the new test case, and specify the new option for it.
|
||
|
Peter Wang
|
1dcebc891b |
Fix -O<n> options below default optimisation level.
The default optimisation level was implemented by having the
Mercury.config file add a -O<n> option to the DEFAULT_MCFLAGS variable.
This allowed the user to override the default optimisation level
by setting the MERCURY_DEFAULT_OPT_LEVEL environment variable.
Commit
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Zoltan Somogyi
|
d493841c99 | Move imports from interface to implementation. | ||
|
Zoltan Somogyi
|
409cbcb6a3 |
Unify getopt.m and getopt_io.m ...
... using an approach proposed by Peter, with an extra twist from Julien.
Instead of having two modules, getopt.m and getopt_io.m, with the former
defining predicates that do not take an I/O state pair, and the latter
defining predicates that do take an I/O state pair, put both kinds of
predicates into a single module. The versions with an I/O state pair
have an "_io" suffix added to their names for disambiguation.
Both versions are a veneer on top of a common infrastructure,
which relies on a simple type class to implement the operation
"give the contents of the file with this name". The predicate versions
with I/O state pairs have a normal implementation of this typeclass,
while the predicate versions that do not have I/O state pairs
have an implementation that always returns an error indication.
The above change just about doubles the number of exported predicates.
We already had two versions of most exported predicates that differed
in whether we returned errors in the form of a string, or in the form
of a structured representation, with names of the latter having
an "_se" suffix. Since we agreed that the structured representation
is the form we want to encourage, this diff deletes the string versions,
and deletes the "_se" suffix from the predicate names that used to have them.
(It still remains at the end of the name of a type.) This "undoubling"
should offset the effect of the doubling in the previous paragraph.
Eventually, we want to have just one module, getopt.m, containing
the updated code described above, but for now, we put the same code
into both getopt_io.m and getopt.m to prevent too big a shock to
people with existing code that uses getopt_io.m.
library/getopt.m:
library/getopt_io.m:
Make the changes described above.
library/Mmakefile:
Instead of building both getopt_io.m and getopt.m from getopt_template,
build getopt.m from getopt_io.m.
tools/bootcheck:
Delete references to getopt_template.
compiler/typecheck_errors.m:
When a type error involves one of the getopt/getopt_io predicates
whose interfaces are changed by this diff, tell the user about
how these changes could have caused the error, and thus what the
probable fix is.
compiler/handle_options.m:
browser/parse.m:
deep_profiler/mdprof_cgi.m:
deep_profiler/mdprof_create_feedback.m:
deep_profiler/mdprof_dump.m:
deep_profiler/mdprof_procrep.m:
deep_profiler/mdprof_report_feedback.m:
deep_profiler/mdprof_test.m:
profiler/mercury_profile.m:
slice/mcov.m:
slice/mdice.m:
slice/mslice.m:
slice/mtc_diff.m:
slice/mtc_union.m:
tests/hard_coded/space.m:
Use the updated getopt interface.
compiler/compile_target_code.m:
compiler/compute_grade.m:
compiler/deforest.m:
compiler/det_report.m:
compiler/format_call.m:
compiler/globals.m:
compiler/goal_expr_to_goal.m:
compiler/make.build.m:
compiler/make.m:
compiler/make.module_dep_file.m:
compiler/make.program_target.m:
compiler/make.util.m:
compiler/mercury_compile_main.m:
compiler/ml_top_gen.m:
compiler/module_cmds.m:
compiler/op_mode.m:
compiler/optimization_options.m:
compiler/options.m:
compiler/write_module_interface_files.m:
tools/make_optimization_options_middle:
tools/make_optimization_options_start:
Replace references to getopt_io.m with references to getopt.m.
tests/invalid/getopt_io_old.{m,err_exp}:
tests/invalid/getopt_old.{m,err_exp}:
tests/invalid/getopt_old_se.{m, err_exp}:
New test cases for the extra help
tests/invalid/Mmakefile:
Enable the new test cases.
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Zoltan Somogyi
|
223c6eddbc |
Break up a large predicate to avoid JVM limits.
tools/make_optimization_options_middle:
Generate a separate predicate for each arm of the switch
in update_opt_tuple that handles a bool or int option.
These form the vast majority of switch arms. This means that
so that the Java code we generate for update_opt_tuple,
which used to break the 64k limit on the maximum bytecode size
of a method (Mantis bug #522), should not break it anymore.
compiler/optimization_options.m:
Rebuild the contents of this file using the updated generator script
above.
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Zoltan Somogyi
|
81cddd5572 |
Make --optx=N work after -O... sets it to >N.
tools/make_optimization_options_middle:
tools/make_optimization_options_end:
Differentiate between an option being set explicitly and an option
being set implicitly by -O<N>. In the explicit case, always set integer
values exactly as they are, which allows such options to both increase
and decrease their values. In the implicit case, set the maximum of
the old and new values, which allows -O<N> to increase their values
but not to decrease them.
compiler/optimization_options.m:
Update the auto-generated code.
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Zoltan Somogyi
|
181ada0dbf |
Avoid -O<n> resetting previously set options.
This implements Mantis feature request #495. NEWS: Announce the change. compiler/optimization_options.m: A new module for managing optimization options. It defines a separate bespoke type for every boolean optimization option to make it harder to confuse them. It defines a tuple type (opt_tuple) for accessing optimization options quickly. It implements the turning on (but NOT turning off) of optimizations when a given optimization level is selected. tools/make_optimization_options_middle: tools/make_optimization_options_db: The script that generates the meat of optimization_options.m, and the database of option names, kinds and initial values that it uses as its input. The script also generates some code for the special_handler predicate in compiler/options.m. tools/make_optimization_options_start: tools/make_optimization_options_end: The handwritten initial and final parts of optimization_options.m. tools/make_optimization_options: The script that pulls these parts together to form optimization_options.m. compiler/options.m: Make every optimization option a special option, to be handled by the special_handler predicate. That handling consists of simply adding a representation of the option to the end of a cord of optimization options, to be processed later by optimization_options.m. That processing will record the values of these options in the opt_tuple, which is where every other part of the compiler should get them from. Change the interface of special_handler to make the above possible. Add an "optopt_" (optimization option) prefix to the name of every optimization option, to make them inaccessible to the rest of the compiler under their old name, and thus help enforce the switch to using the opt_tuple. Any access to these options to look up their values would fail anyway, since the option data would no longer be e.g. bool(yes), but bool_special, but the name change makes this failure happen at compile time, not runtime. Reclassify a few options to make the above make sense. Some options (unneeded_code_debug, unneeded_code_debug_pred_name, and common_struct_preds) were classified as oc_opt even though they control only the *debugging* of optimizations, while some options (c_optimize and inline_alloc) were not classified as oc_opt even though we do set them automatically at some optimization levels. Delete the opt_level_number option, since it was not used anywhere. Delete the code for handling -ON and --opt-space, since that is now done in optimization_options.m. Add some XXXs. compiler/handle_options.m: Switch to using getopt_io.process_options_userdata_se, as required by the new interface of the special_handler in options.m. In the absence of errors, invoke optimization_options.m to initialize the opt_tuple. Then update the opt_tuple incrementally when processing option implications that affect optimization options. compiler/globals.m: Put the opt_tuple into a new field of the globals structure. compiler/accumulator.m: compiler/add_pragma_type_spec.m: compiler/add_trail_ops.m: compiler/code_info.m: compiler/code_loc_dep.m: compiler/compile_target_code.m: compiler/const_struct.m: compiler/deforest.m: compiler/dep_par_conj.m: compiler/disj_gen.m: compiler/erl_code_gen.m: compiler/format_call.m: compiler/global_data.m: compiler/grab_modules.m: compiler/higher_order.m: compiler/hlds_pred.m: compiler/inlining.m: compiler/intermod.m: compiler/ite_gen.m: compiler/jumpopt.m: compiler/libs.m: compiler/llds_out_code_addr.m: compiler/llds_out_data.m: compiler/llds_out_file.m: compiler/llds_out_instr.m: compiler/llds_out_util.m: compiler/matching.m: compiler/mercury_compile_front_end.m: compiler/mercury_compile_llds_back_end.m: compiler/mercury_compile_main.m: compiler/mercury_compile_middle_passes.m: compiler/mercury_compile_mlds_back_end.m: compiler/ml_disj_gen.m: compiler/ml_gen_info.m: compiler/ml_lookup_switch.m: compiler/ml_optimize.m: compiler/ml_proc_gen.m: compiler/ml_simplify_switch.m: compiler/ml_switch_gen.m: compiler/ml_unify_gen_construct.m: compiler/optimize.m: compiler/pd_util.m: compiler/peephole.m: compiler/polymorphism.m: compiler/proc_gen.m: compiler/simplify_goal_call.m: compiler/simplify_goal_scope.m: compiler/simplify_info.m: compiler/simplify_proc.m: compiler/simplify_tasks.m: compiler/stack_layout.m: compiler/stack_opt.m: compiler/switch_gen.m: compiler/switch_util.m: compiler/tag_switch.m: compiler/tupling.m: compiler/unify_gen_construct.m: compiler/unneeded_code.m: compiler/unused_args.m: Conform to the changes above, mostly by looking up optimization options in the opt_tuple. In some places, replace bools containing optimization options with the bespoke type of that specific optimization option. library/getopt_template: Fix a bug that screwed up an error message. The bug happened when processing a --file option. If one of the options in the file was a special option whose special handler failed, the code handling that failing option returned both an error indication, and the rest of the argument list read in from the file. The code handling the --file option then *ignored* the error indication from the failed special option, and returned an error message of its own complaining about the unconsumed remaining arguments in the file, believing them to be non-option arguments, even though these arguments were never looked it to see if they were options. The fix is for the code handling --flag options to check whether the code processing the file contents found any errors, and if so, return that error *without* looking at the list of remaining arguments. In an unrelated change, factor out a duplicate call. |