Commit Graph

14 Commits

Author SHA1 Message Date
Zoltan Somogyi
86f563a94d Pack subword-sized arguments next to a remote sectag.
compiler/du_type_layout.m:
    If the --allow-packing-remote-sectag option is set, then try to pack
    an initial subsequence of subword-sized arguments next to remote sectags.

    To allow the polymorphism transformation to put the type_infos and/or
    typeclass_infos it adds to a function symbol's argument list at the
    *front* of that argument list, pack arguments next to remote sectags
    only in function symbols that won't have any such extra arguments
    added to them.

    Do not write all new code for the new optimization; instead, generalize
    the code that already does a very similar job for packing args next to
    local sectags.

    Delete the code we used to have that picked the packed representation
    over the base unpacked representation only if it reduced the
    "rounded-to-even" number of words. A case could be made for its usefulness,
    but in the presence of the new optimization the extra code complexity
    it requires is not worth it (in my opinion).

    Extend the code that informs users about possible argument order
    rearrangements that yield better packing to take packing next to sectags
    into account.

compiler/hlds_data.m:
    Provide a representation for cons_tags that use the new optimization.
    Instead of adding a new cons_tag, we do this by replacing several old
    cons_tags that all represent pointers to memory cells with a single
    cons_tag named remote_args_tag with an argument that selects among
    the old cons_tags being replaced, and adding a new alternative inside
    this new type. The new alternative is remote_args_shared with a
    remote_sectag whose size is rsectag_subword(...).

    Instead of representing the value of the "data" field in classes
    on the Java and C# backends as a strange kind of secondary tag
    that is added to a memory cell by a class constructor instead of
    having to be explicitly added to the front of the argument vector
    by the code of a unification, represent it more directly as separate
    kind of remote_args_tag. Continuing to treat it as a sectag would have
    been very confusing to readers of the code of ml_unify_gen_*.m in the
    presence of the new optimization.

    Replacing several cons_tags that were usually treated similarly with
    one cons_tag simplifies many switches. Instead of an switch with that
    branches to the same switch arm for single_functor_tag, unshared_tag
    and shared_remote_tag, and then switches on these three tags again
    to get e.g. the primary tag of each, the new code of the switch arm
    is executed for just cons_tag value (remote_args_tag), and switches
    on the various kinds of remote args tags only when it needs to.
    In is also more natural to pass around the argument of remote_args_tag
    than to pass around a variable of type cons_tag that can be bound to only
    single_functor_tag, unshared_tag or shared_remote_tag.

    Add an XXX about possible further steps along these lines, such as
    making a new cons_tag named something like "user_const_tag" represent
    all user-visible constants.

compiler/unify_gen_construct.m:
compiler/unify_gen_deconstruct.m:
compiler/unify_gen_test.m:
compiler/unify_gen_util.m:
compiler/ml_unify_gen_construct.m:
compiler/ml_unify_gen_deconstruct.m:
compiler/ml_unify_gen_test.m:
compiler/ml_unify_gen_util.m:
    Implement X = f(Yi) unifications where f uses the new representation,
    i.e. some of its arguments are stored next to a remote sectag.

    Some of the Yi are stored in a tagword (a word that also contains a tag,
    in this case the remote secondary tag), while some are stored in other
    words in a memory cell. This means that such unifications have similarities
    both to unifications involving arguments being packed next to local
    sectags, and to unifications involving ordinary arguments in memory cells.
    Therefore wherever possible, their implemenation uses suitably generalized
    versions of existing code that did those two jobs for two separate kinds of
    cons_tags.

    Making such generalizations possible in some cases required shifting the
    boundary between predicates, moving work from a caller to a callee
    or vice versa.

    In unify_gen_deconstruct.m, stop using uni_vals to represent *either* a var
    *or* a word in a memory cell. While this enabled us to factor out some
    common code, the predicate boundaries it lead to are unsuitable for the
    generalizations we now need.

    Consistently use unsigned ints to represent both the whole and the parts
    of words containing packed arguments (and maybe sectags), except when
    comparing ptag constants with the result of applying the "tag" unop
    to a word, (since that unop returns an int, at least for now).

    In a few cases, avoid the recomputation of some information that we
    already know. The motivation is not efficiency, since the recomputation
    we avoid is usually cheap, but the simplification of the code's correctness
    argument.

    Use more consistent terminology in things such as variable names.

    Note the possibility of further future improvements in several places.

compiler/ml_foreign_proc_gen.m:
    Delete a long unused predicate.

compiler/mlds.m:
    Add an XXX documenting a possible improvement.

compiler/rtti.m:
    Update the compiler's internal representation of RTTI data structures
    to make them able to describe secondary tags that are smaller than
    a full word.

compiler/rtti_out.m:
    Conform to the changes above, and delete a long-unused predicate.

compiler/type_ctor_info.m:
    Use the RTTI's du_hl_rep to represent cons_tags that distinguish
    between function symbols using a field in a class.

compiler/ml_type_gen.m:
    Provide a specialized form of a function for code in ml_unify_gen_*.m.
    Conform to the changes above.

compiler/add_special_pred.m:
compiler/bytecode_gen.m:
compiler/export.m:
compiler/hlds_code_util.m:
compiler/lco.m:
compiler/ml_closure_gen.m:
compiler/ml_switch_gen.m:
compiler/ml_tag_switch.m:
compiler/rtti_to_mlds.m:
compiler/switch_util.m:
compiler/tag_switch.m:
    Conform to the changes above.

runtime/mercury_type_info.h:
    Update the runtime's representation of RTTI data structures to make them
    able to describe remote secondary tags that are smaller than a full word.

runtime/mercury_deconstruct.[ch]:
runtime/mercury_deconstruct.h:
runtime/mercury_deconstruct_macros.h:
runtime/mercury_ml_expand_body.h:
runtime/mercury_ml_arg_body.h:
runtime/mercury_ml_deconstruct_body.h:
runtime/mercury_ml_functor_body.h:
    These modules collectively implement the predicates in deconstruct.m
    in the library, and provide access to its functionality to other C code,
    e.g. in the debugger. Update these to be able to handle terms with the
    new data representation optimization.

    This update requires a significant change in the distribution of work
    between these files for the predicates deconstruct.deconstruct and
    deconstruct.limited_deconstruct. We used to have mercury_ml_expand_body.h
    fill in the fields of their expand_info structures (whose types are
    defined in mercury_deconstruct.h) with pointers to three vectors:
    (a) a vector of arg_locns with one element per argument, with a NULL
    pointer being equivalent to a vector with a given element in every slot;
    (b) a vector of type_infos with one element per argument, constructed
    dynamically (and later freed) if necessary; and (c) a vector of argument
    words. Once upon a time, before double-word and sub-word arguments,
    vector (c) also had one word per argument, but that hasn't been true
    for a while; we added vector (a) help the consumers of the expand_info
    decode the difference. The consumers of this info  always used these
    vectors to build up a Mercury term containing a list of univs,
    with one univ for each argument.

    This structure could be stretched to handle function symbols that store
    *all* their arguments in a tagword next to a local sectag, but I found
    that stretching it to cover function symbols that have *some* of their
    arguments packed next to a remote sectag and *some other* of their
    arguments in a memory cell as usual would have required a well-nigh
    incomprehensibly complex, and therefore almost undebuggable, interface
    between mercury_ml_expand_body.h and the other files above. This diff
    therefore changes the interface to have mercury_ml_expand_body.h
    build the list of univs directly. This make its code relatively simple
    and self-contained, and it should be somewhat faster then the old code
    as well, since it never needs to allocate, fill in and then free
    vectors of type_infos (each such typeinfo now gets put into a univ
    as soon as it is constructed). The downside is that if we ever wanted
    to get all the arguments at once for a purpose other than constructing
    a list of univs from them, it would nevertheless require constructing
    that list of univs anyway as an intermediate data structure. I don't see
    this downside is significant, because (a) I don't think such a use case
    is very likely, and (b) even if one arises, debuggable but a bit slow
    is probably preferable to faster but very hard to debug.

    Reduce the level of indentation of some of these files to make the code
    easier to edit. Do this by

    - not adding an indent level from switch statements to their cases; and
    - not adding an indent level when a case in a switch has a local block.

    Move the break or return ending a case inside that case's block,
    if it has one.

runtime/mercury_deep_copy_body.h:
runtime/mercury_table_type_body.h:
    Update these to enable the copying or tabling of terms whose
    representations uses the new optimization.

    Use the techniques listed above to reduce the level of indentation
    make the code easier to edit.

runtime/mercury_tabling.c:
runtime/mercury_term_size.c:
    Conform to the changes above.

runtime/mercury_unify_compare_body.h:
    Make this code compile after the changes above. It does need to work
    correctly, since we only ever used this code to compare the speed
    of unify-by-rtti with the speed of unify-by-compiler-generated-code,
    and in real life, we always use the latter. (It hasn't been updated
    to work right with previous arg packing changes either.)

library/construct.m:
    Update to enable the code to construct terms whose representations
    uses the new optimization.

    Add some sanity checks.

library/private_builtin.m:
runtime/mercury_dotnet.cs.in:
java/runtime/Sectag_Locn.java:
    Update the list of possible sectag kinds.

library/store.m:
    Conform to the changes above.

trace/mercury_trace_vars.c:
    Conform to the changes above.

tests/hard_coded/deconstruct_arg.{m,exp,exp2}:
    Extend this test to test the deconstruction of terms whose
    representations uses the new optimization.

    Modify some of the existing terms being tested to make them more diverse,
    in order to make the output easier to navigate.

tests/hard_coded/construct_packed.{m,exp}:
    A new test case to test the construction of terms whose
    representations uses the new optimization.

tests/debugger/browse_packed.{m,exp}:
    A new test case to test access to the fields of terms whose
    representations uses the new optimization.

tests/tabling/test_packed.{m,exp}:
    A new test case to test the tabling of terms whose
    representations uses the new optimization.

tests/debugger/Mmakefile:
tests/hard_coded/Mmakefile:
tests/tabling/Mmakefile:
    Enable the new test cases.
2018-08-30 05:14:38 +10:00
Mark Brown
d465fa53cb Update the COPYING.LIB file and references to it.
Discussion of these changes can be found on the Mercury developers
mailing list archives from June 2018.

COPYING.LIB:
    Add a special linking exception to the LGPL.

*:
    Update references to COPYING.LIB.

    Clean up some minor errors that have accumulated in copyright
    messages.
2018-06-09 17:43:12 +10:00
Zoltan Somogyi
24b98fdafe Pack sub-word-sized ints and dummies in terms.
Previously, the only situation in which we could pack two or more arguments
of a term into a single word was when all those arguments are enums. This diff
changes that, so that the arguments can also be sub-word-sized integers
(signed or unsigned), or values of dummy types (which occupy zero bits).

This diff also records, for each argument of a function symbol, not just
whether, and if yes, how it is packed into a word, but also at *what offset*
that word is in the term's heap cell. It is more economical to compute this
once, when the representation of the type is being decided, than to compute
it over and over again when terms with that function symbol are being
constructed or deconstructed. However, for a transition period, we compute
these offsets at *both* times, to check the consistency of the new algorithm
for computing offsets that is run at "decide representation time" with
the old algorithms run at "generate code for a unification time".

compiler/du_type_layout.m:
    Make the changes described above: pack sub-word-sized integers and
    dummy values into argument words, if possible, and if the relevant
    new option allows it. These options are temporary. If we find no problems
    with the new packing algorithm in a few weeks, we should be able to
    delete them.

    Allow 64 bit ints and uints to be stored in unboxed in two words
    on 32 bit platforms, if the relevant new option allows it. Support
    for this is not yet complete, but it makes sense to implement the
    RTTI changes for both this change and one described in the above
    paragraph together.

    For each packed argument, record not just its width, its shift and
    the mask, but also the number of bits the argument takes. Previously,
    we computed this on demand from the mask, but there is no real need
    for that when simply storing this info is so cheap.

    For all arguments, packed or not, record its offset, relative to both
    the start of the arguments, and the start of the memory cell. (The two
    are different if the arguments are preceded by either a remote secondary
    tag, the typeinfos and/or typeclass_infos describing some existentially
    typed arguments, or both.) The reason for this is given at the top.

    Centralize the decision of the parameters of packing in one predicate.

    If the option --inform-suboptimal-packing is given, print an informational
    message whenever the code deciding type representations finds that
    reordering the arguments of a function symbol would allow it to pack
    the arguments of that function symbol into less space.

compiler/options.m:
    Add the option --allow-packing-ints which controls whether
    du_type_layout.m will attempt to pack {int,uint}{8,16,32} arguments
    alongside enum arguments.

    Add the option --allow-packing-dummies which controls whether
    du_type_layout.m will optimize away (in other words, represent in 0 bits)
    arguments of dummy types.

    Add the option --allow-double-word-ints which controls whether
    du_type_layout.m will store arguments of the types int64 and uint64
    unboxed in two words on 32 bit platforms, the way it currently stores
    double precision floats.

    All three those options are off by default, which preserves binary
    compatibility with existing code. However, the first two are ready
    to be switched on (the third is not).

    All three options are intended to be present in the compiler
    only until these changes are tested. Once we deem them sufficiently
    tested, I will modify the compiler to always do the packing they control,
    at which point we can delete these options. This is why they are not
    documented.

    Add the option --inform-suboptimal-packing, whose meaning is described
    above.

doc/user_guide.texi:
    Document --inform-suboptimal-packing.

compiler/prog_data.m:
    For each argument of a function symbol in a type definition, use
    a new type called arg_pos_width to record the extra information
    mentioned above in (offsets for all arguments, and number of bits
    for packed arguments).

    For each function symbol that has some existential type constraints,
    record the extra information mentioned for parse_type_defn.m below.

compiler/hlds_data.m:
    Include the position, as well as the width, in the representation
    of the arguments of function symbols.

    Previously, we used the integer 0 as a tag for dummies. Add a tag to
    represent dummy values, since this gives more information to any code
    that sees that tag.

compiler/ml_unify_gen.m:
compiler/unify_gen.m:
    Handle the packing of dummy values, and of sub-word-sized ints and uints.

    Compare the cell offset of each argument computed using existing
    algorithms here with the cell offset recorded in the argument's
    representation, and abort if they are different.

    In some cases, restructure code a bit to make it possible.
    For example, for tuples and closures, this means that instead of
    simply recording that each tuple argument or closure element
    is a full word, we must record its correct offset as well.

    Handle the new dummy_tag.

    Add prelim (not yet finished) support for double-word int64s/uint64s
    on 32 bit platforms.

    When packing the values of two or more variables (or constants) into a
    single word in a memory cell, optimize away operations that are no-ops,
    such as shifting anything by zero bits, shifting the constant zero
    by any number of bits, and ORing anything with zero. This makes the
    generated code easier to read. It is probably also faster for us
    to do it here than to write out a bigger expression, have the C compiler
    read in the bigger expression, and then later make the same optimization.

    In ml_unify_gen.m, avoid the unnecessary use of a list of the argument
    variables' types separate from the list of the argument variables
    themselves; just look up the type of each argument variable when it is
    processed.

compiler/add_special_pred.m:
    When creating special (unify and compare) predicates for tuples,
    include the offsets in the representation of their arguments.

    Delete an unused predicate.

compiler/llds.m:
    Add a new way to create an rval: a cast. We use it to implement
    the extraction of signed sub-word-sized integers from packed argument
    words in terms. Masking the right N bits out of the packed word
    leaves the other 32-N or 64-N bits as zeroes; a cast to int8_t,
    int16_t or int32_t will copy the sign bit to these bits.
    Likewise, when we pack signed int{8,16,32} values into words,
    we cast them to their unsigned versions to throw away any sign-extension
    bits in their original word-sized representations.

    No similar change is needed for the MLDS, since that already had
    a mechanism for casts.

compiler/mlds.m:
    Note a potential simplification in the MLDS.

compiler/builtin_lib_types.m:
    Add functions to return the Mercury representation of the int64
    and uint64 types.

compiler/foreign.m:
    Export a specialized version of an existing predicate, to allow
    ml_unify_gen.m to avoid the costs of the more general version.

compiler/hlds_out_module.m:
    Always print the representations of all arguments, since the
    inclusion of position information in those representation means that
    the representations of even all-full-word-argument terms are of potential
    interest when debugging term representations.

compiler/lco.m:
    Do not try to apply LCO to arguments of dummy types. (We could optimize
    them differently, by filling them in before they are "computed", but
    that is a separate optimization, which is of *very* low priority.)

compiler/liveness.m:
    Do not include variables of dummy types in resume points.

    The reason for this is that the code that establishes a resume point
    returns, for each such variable, a list of *lvals* where that variable
    can be found. The new code in unify_gen.m will optimize away assignments
    to values of dummy types, so there is *no* lval where they can be found.
    We could allocate one, but doing so would be a pessimization. Instead,
    we simply don't save and restore such values. When their value (which is
    always 0) is needed, we can create them out of thin air.

compiler/ml_global_data.m:
    Include the target language in the ml_global_data structure, to prevent
    some of its users having to look it up in the module_info.

    Add notes about the specializing the implementation of arrays of
    int64s/uint64s on 32 bit platforms.

compiler/check_typeclass.m:
compiler/ml_type_gen.m:
    Add sanity checks of the new precomputed fields of exist_constraints.

    Conform to the changes above.

compiler/mlds_to_c.m:
    Add prelim (not yet finished) support for double-word int64s/uint64s
    on 32 bit platforms.

    Add notes about possible optimizations.

compiler/parse_type_defn.m:
    When a function symbol in a type definition contains existential
    arguments, precompute and store the set of constrained and unconstrained
    type variables. The code in du_type_layout.m needs this information
    to compute the number of slots occupied by typeinfos and typeclass_infos
    in memory cells for this function symbol, and several other places
    in the compiler do too. It is easier and faster to compute this
    information just once, and this is the earliest time what that can be done.

compiler/type_ctor_info.m:
    Use the prerecorded information about existential types to simplify
    the code here

compiler/polymorphism.m:
    Add an XXX about possibly using the extra info we now record in
    exist_constraints to simplify the job of polymorphism.m.

compiler/pragma_c_gen.m:
compiler/var_locn.m:
    Create the values of dummy variables from scratch, if needed.

compiler/rtti.m:
    Replace a bool with a bespoke type.

compiler/rtti_out.m:
compiler/rtti_to_mlds.m:
    When generating RTTI information for the LLDS and MLDS backends
    respectively, record new kinds of arguments as needing special
    treatment. These are int64s and uint64s stored unboxed in two words
    on 32 bit platforms, {int,uint}{8,16,32} values packed into words,
    and dummy arguments. Each of these has a special code: its own negative
    negative value in the num_bits field of the argument.

    Generate slightly better formatted output.

compiler/type_util.m:
    Delete a predicate that isn't needed anymore.

compiler/opt_util.m:
    Delete a function that hasn't been needed for a while.

    Conform to the changes above.

compiler/arg_pack.m:
compiler/bytecode_gen.m:
compiler/call_gen.m:
compiler/code_util.m:
compiler/ctgc.selector.m:
compiler/dupelim.m:
compiler/dupproc.m:
compiler/equiv_type.m:
compiler/equiv_type_hlds.m:
compiler/erl_code_gen.m:
compiler/erl_rtti.m:
compiler/export.m:
compiler/exprn_aux.m:
compiler/global_data.m:
compiler/jumpopt.m:
compiler/livemap.m:
compiler/llds_out_data.m:
compiler/middle_rec.m:
compiler/ml_closure_gen.m:
compiler/ml_switch_gen.m:
compiler/ml_top_gen.m:
compiler/module_qual.qualify_items.m:
compiler/opt_debug.m:
compiler/parse_tree_out.m:
compiler/peephole.m:
compiler/recompilation.usage.m:
compiler/resolve_unify_functor.m:
compiler/stack_layout.m:
compiler/structure_reuse.direct.choose_reuse.m:
compiler/switch_util.m:
compiler/typecheck.m:
compiler/unify_proc.m:
compiler/unused_imports.m:
compiler/xml_documentation.m:
    Conform to the changes above.

compiler/llds_out_util.m:
    Add a comment.

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

runtime/mercury_type_info.h:
    Allocate special values of the MR_arg_bits field of the MR_DuArgLocn type
    to designate arguments as two word int64/uint64s, as sub-word-sized
    arguments of types {int,uint}{8,16,32}, or as arguments of dummy types.
    (We already had a special value for two word float arguments.)

    Document the list of places that know about this code, so that they
    can be updated if and when it changes.

library/construct.m:
    Handle the construction of terms with two-word int64/uint64 arguments,
    with packed {int,uint}{8,16,32} arguments, and with dummy arguments.

    Factor out the code common to the sectag-present and sectag-absent cases,
    to make it possible to do the above in just *one* place.

library/store.m:
    Add an XXX to a place that I don't think handles two word arguments
    correctly. (I think this is an old bug.)

runtime/mercury_deconstruct.c:
    Handle the deconstruction of terms with two-word int64/uint64 arguments,
    with packed {int,uint}{8,16,32} arguments, and with dummy arguments.

runtime/mercury_deep_copy_body.h:
    Handle the copying of terms with two-word int64/uint64 arguments,
    with packed {int,uint}{8,16,32} arguments, and with dummy arguments.

    Give a macro a more descriptive name.

runtime/mercury_type_info.c:
    Handle taking the size of terms with two-word int64/uint64 arguments,
    with packed {int,uint}{8,16,32} arguments, and with dummy arguments.

runtime/mercury.h:
    Put related definitions next to each other.

runtime/mercury_deconstruct.h:
runtime/mercury_ml_expand_body.h:
    Fix indentation.

tests/hard_coded/construct_test.{m,exp}:
    Add to this test case a test of the construction, via the library's
    construct.m module, of terms containing packed sub-word-sized integers,
    and packed dummies.

tests/hard_coded/deconstruct_arg.{m,exp}:
    Convert the source code of this test case to state variable notation,
    and update the line number references (in the names of predicates created
    from lambda expressions) accordingly.

tests/hard_coded/uint64_ground_term.{m,exp}:
    A new test case to check that uint64 values too large to be int64 values
    can be stored in static structures.

tests/hard_coded/Mmakefile:
    Enable the new test case.
2018-05-05 13:22:19 +02:00
Zoltan Somogyi
53b573692a Convert C code to use // style comments.
runtime/*.[ch]:
trace/*.[chyl]:
    As above. In some places, improve comments, e.g. by expanding contractions
    such as "we've". Add #ifndef guards against double inclusion around
    the trace/*.h files that did not already have them.

tools/*:
    Make the corresponding changes in shell scripts that generate .[ch] files
    in the runtime.

tests/*:
    Conform to a slight change in the text of a message.
2016-07-14 13:57:35 +02:00
Zoltan Somogyi
67326f16e4 Fix style issues in the runtime.
Move all .h and .c files to four-space indentation without tabs,
if they weren't there already.

Use the same vim line for all .h and .c files.

Align all backslashes at the ends of lines in macro definitions.
Align close comment signs.

In some places, fix inconsistent indentation.

Fix a bunch of comments. Add XXXs to a few of them.
2016-07-09 12:14:00 +02:00
Zoltan Somogyi
2f4f8c72cd Prepare for printing more info about foreign type values.
runtime/mercury_deconstruct.h:
    Bring this module up to our current standards of programming style,
    by making type names only camelcase, not camelcase AND underscores.

runtime/mercury_deconstruct.c:
runtime/mercury_ml_expand_body.h:
runtime/mercury_ml_functor_body.h:
library/deconstruct.m:
    Conform to the above.

    In mercury_ml_expand_body.h, fix an old mistake in documentation.

library/rtti_implementation.m:
    Bring this module up to our current standards of programming style.
    Note some inconsistencies. Factor out some common code.

tests/hardcoded/foreign_type.m:
    Bring this module up to our current standards of programming style.

tests/debugger/foreign_type.{m,inp,exp}:
    A new test case, to test the printing of values of foreign types.

tests/debugger/Mmakefile:
    Enable the new test case.
2015-05-31 14:22:55 +02:00
Peter Wang
257efbd678 Store double-precision `float' constructor arguments in unboxed form,
Branches: main

Store double-precision `float' constructor arguments in unboxed form,
in high-level C grades on 32-bit platforms, i.e. `float' (and equivalent)
arguments may occupy two machine words.

As the C code generated by the MLDS back-end makes use of MR_Float variables
and parameters, float (un)boxing may be reduced substantially in many programs.

compiler/prog_data.m:
	Add `double_word' as a new option for constructor argument widths,
	only used for float arguments as yet.

compiler/make_hlds_passes.m:
	Set constructor arguments to have `double_word' width if required,
	and possible.

compiler/type_util.m:
	Add helper predicate.

compiler/builtin_ops.m:
compiler/c_util.m:
compiler/llds.m:
	Add two new binary operators used by the MLDS back-end.

compiler/arg_pack.m:
	Handle `double_word' arguments.

compiler/ml_code_util.m:
	Deciding whether or not a float constructor argument requires boxing
	now depends on the width of the field.

compiler/ml_global_data.m:
	When a float constant appears as an initialiser of a generic array
	element, it is now always unboxed, irrespective of --unboxed-float.

compiler/ml_type_gen.m:
	Take double-word arguments into account when generating structure
	fields.

compiler/ml_unify_gen.m:
	Handle double-word float constructor arguments in (de)constructions.
	In some cases we break a float argument into its two words, so
	generating two assignments statements or two separate rvals.

	Take double-word arguments into account when calculating field offsets.

compiler/mlds_to_c.m:
	The new binary operators require no changes here.

	As a special case, write `MR_float_from_dword_ptr(&X)' instead of
	`MR_float_from_dword(X, Y)' when X, Y are consecutive words within a
	field. The definition of `MR_float_from_dword_ptr' is more
	straightforward, and gcc produces better code than if we use the more
	general `MR_float_from_dword'.

compiler/rtti_out.m:
	For double-word arguments, generate MR_DuArgLocn structures with
	MR_arg_bits set to -1.

compiler/rtti_to_mlds.m:
	Handle double-word arguments in field offset calculation.

compiler/unify_gen.m:
	Partially handle double_word arguments in LLDS back-end.

compiler/handle_options.m:
	Set --unboxed-float when targetting Java, C# and Erlang.

compiler/structure_reuse.direct.choose_reuse.m:
	Rename a predicate.

compiler/bytecode.m:
compiler/equiv_type.m:
compiler/equiv_type_hlds.m:
compiler/llds_to_x86_64.m:
compiler/mlds_to_gcc.m:
compiler/mlds_to_il.m:
compiler/opt_debug.m:
	Conform to changes.

library/construct.m:
library/store.m:
	Handle double-word constructor arguments.

runtime/mercury_conf.h.in:
	Clarify what `MR_BOXED_FLOAT' now means.

runtime/mercury_float.h:
	Add helper macros for converting between doubles and word/dwords.

runtime/mercury_deconstruct.c:
runtime/mercury_deconstruct.h:
	Add a macro `MR_arg_value' and a helper function to extract a
	constructor argument value.  This replaces `MR_unpack_arg'.

runtime/mercury_type_info.h:
	Remove `MR_unpack_arg'.

	Document that MR_DuArgLocn.MR_arg_bits may be -1.

runtime/mercury_deconstruct_macros.h:
runtime/mercury_deep_copy_body.h:
runtime/mercury_ml_arg_body.h:
runtime/mercury_table_type_body.h:
runtime/mercury_tabling.c:
runtime/mercury_type_info.c:
	Handle double-word constructor arguments.

tests/hard_coded/Mercury.options:
tests/hard_coded/Mmakefile:
tests/hard_coded/lco_double.exp:
tests/hard_coded/lco_double.m:
tests/hard_coded/pack_args_float.exp:
tests/hard_coded/pack_args_float.m:
	Add test cases.

trace/mercury_trace_vars.c:
	Conform to changes.
2011-09-06 05:20:45 +00:00
Peter Wang
0ae65de577 Pack consecutive enumeration arguments in discriminated union types into a
Branches: main

Pack consecutive enumeration arguments in discriminated union types into a
single word to reduce cell sizes.  Argument packing is only enabled on C
back-ends with low-level data, and reordering arguments to improve
opportunities for packing is not yet attempted.  The RTTI implementations for
other back-ends will need to be updated, but that is best left until after any
argument reordering change.

Modules which import abstract enumeration types are notified so by writing
declarations of the form:

	:- type foo where type_is_abstract_enum(NumBits).

into the interface file for the module which defines the type.


compiler/prog_data.m:
	Add an `arg_width' argument to constructor arguments.

	Replace `is_solver_type' by `abstract_type_details', with an extra
	option for abstract exported enumeration types.

compiler/handle_options.m:
compiler/options.m:
	Add an internal option `--allow-argument-packing'.

compiler/make_hlds_passes.m:
	Determine whether and how to pack enumeration arguments, updating the
	`arg_width' fields of constructor arguments before constructors are
	added to the HLDS.

compiler/mercury_to_mercury.m:
compiler/modules.m:
	Write `where type_is_abstract_enum(NumBits)' to interface files
	for abstract exported enumeration types.

compiler/prog_io_type_defn.m:
	Parse `where type_is_abstract_enum(NumBits)' attributes on type
	definitions.

compiler/arg_pack.m:
compiler/backend_libs.m:
	Add a new module.  This mainly contains a predicate which packs rvals
	according to arg_widths, which is used by both LLDS and MLDS back-ends.

compiler/ml_unify_gen.m:
compiler/unify_gen.m:
	Take argument packing into account when generating code for
	constructions and deconstructions.  Only a relatively small part of the
	compiler actually needs to understand argument packing.  The rest works
	at the HLDS level with constructor arguments and variables, or at the
	LLDS and MLDS levels with structure fields.

compiler/code_info.m:
compiler/var_locn.m:
	Add assign_field_lval_expr_to_var and
	var_locn_assign_field_lval_expr_to_var.

	Allow more kinds of rvals in assign_cell_arg.  I do not know why it was
	previously restricted, except that the other kinds of rvals were not
	encountered as cell arguments before.

compiler/mlds.m:
	We can now rely on the compiler to pack arguments in the
	mlds_decl_flags type instead of doing it manually.  A slight downside
	is that though the type is packed down to a single word cell, it will
	still incur a memory allocation per cell.  However, I did not notice
	any difference in compiler speed.

compiler/rtti.m:
compiler/rtti_out.m:
	Add and output a new field for MR_DuFunctorDesc instances, which, if
	any arguments are packed, points to an array of MR_DuArgLocn.  Each
	array element describes the offset in the cell at which the argument's
	value is held, and which bits of the word it occupies.  In the more
	common case where no arguments are packed, the new field is simply
	null.

compiler/rtti_to_mlds.m:
	Generate the new field to MR_DuFunctorDesc.

compiler/structure_reuse.direct.choose_reuse.m:
	For now, prevent structure reuse reusing a dead cell which has a
	different constructor to the new cell.  The code to determine whether a
	dead cell will hold the arguments of a new cell with a different
	constructor will need to be updated to account for argument packing.

compiler/type_ctor_info.m:
	Bump RTTI version number.

	Conform to changes.

compiler/add_type.m:
compiler/check_typeclass.m:
compiler/equiv_type.m:
compiler/equiv_type_hlds.m:
compiler/erl_rtti.m:
compiler/hlds_data.m:
compiler/hlds_out_module.m:
compiler/intermod.m:
compiler/make_tags.m:
compiler/mlds_to_gcc.m:
compiler/opt_debug.m:
compiler/prog_type.m:
compiler/recompilation.check.m:
compiler/recompilation.version.m:
compiler/special_pred.m:
compiler/type_constraints.m:
compiler/type_util.m:
compiler/unify_proc.m:
compiler/xml_documentation.m:
	Conform to changes.

	Reduce code duplication in classify_type_defn.

compiler/hlds_goal.m:
	Clarify a comment.

library/construct.m:
	Make `construct' pack arguments when necessary.

	Remove an old RTTI version number check as recommended in
	mercury_grade.h.

library/store.m:
	Deal with packed arguments in this module.

runtime/mercury_grade.h:
	Bump binary compatibility version number.

runtime/mercury_type_info.c:
runtime/mercury_type_info.h:
	Bump RTTI version number.

	Add MR_DuArgLocn structure definition.

	Add a macro to unpack an argument as described by MR_DuArgLocn.

	Add a function to determine a cell's size, since the number of
	arguments is no longer correct.

runtime/mercury_deconstruct.c:
runtime/mercury_deconstruct.h:
runtime/mercury_deconstruct_macros.h:
runtime/mercury_ml_arg_body.h:
runtime/mercury_ml_expand_body.h:
	Deal with packed arguments when deconstructing.

	Remove an old RTTI version number check as recommended in
	mercury_grade.h.

runtime/mercury_deep_copy_body.h:
	Deal with packed arguments when copying.

runtime/mercury_table_type_body.h:
	Deal with packed arguments in tabling.

runtime/mercury_dotnet.cs.in:
	Add DuArgLocn field to DuFunctorDesc. Argument packing is not enabled
	for the C# back-end yet so this is unused.

trace/mercury_trace_vars.c:
	Deal with packed arguments in MR_select_specified_subterm,
	use for the `hold' command.

java/runtime/DuArgLocn.java:
java/runtime/DuFunctorDesc.java:
	Add DuArgLocn field to DuFunctorDesc. Argument packing is not enabled
	for the Java back-end yet so this is unused.

extras/trailed_update/tr_store.m:
	Deal with packed arguments in this module (untested).

extras/trailed_update/samples/interpreter.m:
extras/trailed_update/tr_array.m:
	Conform to argument reordering in the array, map and other modules in
	previous changes.

tests/hard_coded/Mercury.options:
tests/hard_coded/Mmakefile:
tests/hard_coded/lco_pack_args.exp:
tests/hard_coded/lco_pack_args.m:
tests/hard_coded/pack_args.exp:
tests/hard_coded/pack_args.m:
tests/hard_coded/pack_args_copy.exp:
tests/hard_coded/pack_args_copy.m:
tests/hard_coded/pack_args_intermod1.exp:
tests/hard_coded/pack_args_intermod1.m:
tests/hard_coded/pack_args_intermod2.m:
tests/hard_coded/pack_args_reuse.exp:
tests/hard_coded/pack_args_reuse.m:
tests/hard_coded/store_ref.exp:
tests/hard_coded/store_ref.m:
tests/invalid/Mmakefile:
tests/invalid/where_abstract_enum.err_exp:
tests/invalid/where_abstract_enum.m:
tests/tabling/Mmakefile:
tests/tabling/pack_args_memo.exp:
tests/tabling/pack_args_memo.m:
	Add new test cases.

tests/hard_coded/deconstruct_arg.exp:
tests/hard_coded/deconstruct_arg.exp2:
tests/hard_coded/deconstruct_arg.m:
	Add constructors with packed arguments to these cases.

tests/invalid/where_direct_arg.err_exp:
	Update expected output.
2011-07-05 03:34:39 +00:00
Simon Taylor
6de3b102ba Add support for deconstructing by functor number rather than name,
Estimated hours taken: 20
Branches: main

Add support for deconstructing by functor number rather than name,
for use by write_binary.

library/deconstruct.m:
runtime/mercury_deconstruct.h:
runtime/mercury_deconstruct.c:
runtime/mercury_ml_expand_body.h:
runtime/mercury_ml_deconstruct_body.h:
	Add predicates deconstruct.functor_number and
	deconstruct.deconstruct.du, which returns a functor number
	suitable for use by construct.construct rather than a functor
	name.

library/construct.m:
library/term.m:
browser/term_rep.m:
extras/quickcheck/qcheck.m:
tests/valid/agc_unbound_typevars.m:
tests/valid/agc_unbound_typevars2.m:
	Add a function get_functor_lex, which returns the lexicographic
	functor number given an ordinal functor number.

	Add equivalence types to make it clearer which ordering is
	being used by which functor numbers.

	Remove a C-ism: num_functors now fails rather than returning -1
	for types without functors.

NEWS:
	Document the new predicates and functions.

runtime/mercury_type_info.h:
runtime/mercury_builtin_types.c:
runtime/mercury_mcpp.h:
compiler/rtti.m:
compiler/rtti_out.m:
compiler/type_ctor_info.m:
compiler/rtti_to_mlds.m:
compiler/opt_debug.m:
	Add a field to MR_TypeCtorInfo which contains a mapping from
	an ordinal functor number to a lexicographic functor number
	which can be passed to construct.construct.

	Bump MR_RTTI_VERSION.

tests/hard_coded/expand.m:
tests/hard_coded/expand.exp:
tests/hard_coded/expand.exp2:
tests/hard_coded/construct_test.m:
tests/hard_coded/construct_test.exp:
tests/hard_coded/construct_test_exist.m:
tests/hard_coded/construct_test_exist.exp:
	Test cases.
2007-01-05 02:19:46 +00:00
Zoltan Somogyi
d1c13d57c5 Fix some layout issues in these files. There are no algorithmic
Estimated hours taken: 0.3
Branches: main

runtime/mercury_accurate_gc.h:
runtime/mercury_agc_debug.h:
runtime/mercury_array_macros.h:
runtime/mercury_construct.h:
runtime/mercury_deconstruct.h:
runtime/mercury_init.h:
runtime/mercury_layout_util.h:
runtime/mercury_stack_layout.h:
runtime/mercury_stack_trace.h:
runtime/mercury_trail.h:
	Fix some layout issues in these files. There are no algorithmic
	changes.
2005-06-21 03:12:03 +00:00
Fergus Henderson
d1edaa88a4 Fix indentation.
Estimated hours taken: 0.1
Branches: main

runtime/mercury_deconstruct.h:
	Fix indentation.
2002-09-15 16:21:22 +00:00
Simon Taylor
b7c4a317e9 Add MR_ prefixes to the remaining non-prefixed symbols.
Estimated hours taken: 4
Branches: main

Add MR_ prefixes to the remaining non-prefixed symbols.

This change will require all workspaces to be updated
The compiler will start generating references to MR_TRUE,
MR_bool, etc., which are not defined in the old runtime
header files.

runtime/mercury_std.h:
	Add MR_ prefixes to bool, TRUE, FALSE, max, min,
	streq, strdiff, strtest, strntest, strneq, strndiff,
	strntest, NO_RETURN.

	Delete a commented out definition of `reg'.

runtime/mercury_tags.h:
	Add an MR_ prefix to TAGBITS.

configure.in:
runtime/mercury_goto.h:
runtime/machdeps/i386_regs.h/mercury_goto.h:
	Add an MR_ prefix to PIC.

runtime/mercury_conf_param.h:
	Allow non-prefixed PIC and HIGHTAGS to be defined on
	the command line.

runtime/mercury_bootstrap.h:
	Add backwards compatibility definitions.

RESERVED_MACRO_NAMES:
	Remove the renamed macros.

compiler/export.m:
compiler/ml_code_gen.m:
	Use MR_bool rather than MR_Bool (MR_Bool is
	meant to be for references to the Mercury type
	bool__bool).

runtime/mercury_types.h:
	Add a comment the MR_Bool is for references to
	bool__bool.

*/*.c:
*/*.h:
*/*.m:
	Add MR_ prefixes.
2002-02-18 07:01:33 +00:00
Zoltan Somogyi
fcccbd166f Reorganize deconstruct.m so that each predicate that deconstructs terms has
Estimated hours taken: 12
Branches: main

Reorganize deconstruct.m so that each predicate that deconstructs terms has
three variants:

- One that aborts when attempting to deconstruct non-canonical terms.

- One that succeeds when attempting to deconstruct a term of a non-canonical
  type, but returns a constant such as "<<noncanonical>>" for such
  deconstructions. It still aborts when deconstructing a noncanonical term
  of an ordinarily canonical type, which can happen with HAL if the term
  is currently a variable.

- One that succeeds when attempting to deconstruct non-canonical terms of both
  kinds, but whose determinism requires its caller to be in a committed choice
  context.

Each of the predicates function, arg, named_arg, deconstruct and
limited_deconstruct now has an extra argument that selects one of the three
variants above. Each of these predicates now has three modes, one for each
value of this argument. The separate predicates with _cc at the ends of their
names are now superseded by one of these modes.

At the same time, I also eliminated the distinction between arg and argument.
Arg used to check if the returned argument was of the expected type, and fail
if it wasn't, while argument used to return a univ. The new arg now returns
a value of an existential type, which the caller can now typecheck or put
into a univ as it pleases.

The descriptions of the changes:

library/deconstruct.m:
	Implement the changes discussed above. Work around a bug by making
	the foreign_procs return a univ from which we later extract the value;
	this inefficiency should be fixed later, when the typechecker has been
	fixed to allow different clauses to return existentially typed values.

library/std_util.m:
	Reimplement the forwarding predicates that call deconstruct.m in terms
	of its new interface.

library/io.m:
	Make use of the new functionality in deconstruct.m to offer versions
	of io__print and io__write that allow the user to choose how to print
	noncanonical terms.

library/private_builtin.m:
	Export the `sorry' predicate for use in deconstruct.m and elsewhere.

runtime/mercury_deconstruct.[ch]:
runtime/mercury_ml_expand_body.h:
runtime/mercury_ml_arg_body.h:
runtime/mercury_ml_deconstruct_body.h:
runtime/mercury_ml_functor_body.h:
	Implement the new functionality.

library/store.m:
extras/trailed_update/tr_store.m:
	Conform to the new interfaces of some functions in the updated files
	in the runtime.

tests/debugger/polymorphic_output.exp*:
	Update for an updated error message.

tests/hard_coded/deconstruct_arg.{m,exp*}:
	Update the test case to test the committed choice versions of the
	deconstruction predicates as well as the usual versions. (The aborting
	versions cannot all be tested in a single test case.)
2002-02-04 05:23:10 +00:00
Zoltan Somogyi
ce62be8669 Add committed choice versions of the functions and predicates that deconstruct
Estimated hours taken: 12
Branches: main

Add committed choice versions of the functions and predicates that deconstruct
terms. These versions succeed even if the the term being deconstructed is of a
non-canonical type.

NEWS:
	Mention the new procedures.

library/std_util.m:
	Add the following procedures: functor_cc, argument_cc, det_argument_cc,
	named_argument_cc, det_named_argument_cc, deconstruct_cc and
	limited_deconstruct_cc.

	To avoid code duplication, factor out the code common to several
	procedures and put it into three new files in the runtime directory,
	mercury_ml_{fuctor,arg,deconstruct__body.h.

	Add arguments to the various expansion functions to control what they
	should do for non-canonical types. Move them to mercury_deconstruct.c
	in the runtime directory to make it easier to access them from other
	places.

	Fix some bugs in the code for det_arg and family in the computation
	of abort messages.

library/store.m:
extras/trailed_update/tr_store.m:
trace/mercury_trace_vars.c:
	Adjust the references to the expansion functions.

runtime/mercury_deconstruct.[ch]:
	A new module to contain the expansion functions.

runtime/mercury_ml_arg_body.h:
runtime/mercury_ml_deconstruct_body.h:
runtime/mercury_ml_functor_body.h:
	New files to contain the bodies of the std_util procedures for
	deconstructing terms.

runtime/mercury_deconstruct_macros.h:
	A new header file for macros used in several places.

library/Mmakefile:
runtime/Mmakefile:
	Add the new files to the required lists.
2002-01-09 06:41:35 +00:00