library/version_array.m:
Add the above function.
Minor fixes to some comments.
tests/hard_coded/version_array_test.{m,exp}:
Extend this test to cover from_reverse_list/1 and
from_list/1.
NEWS:
Announce the addition.
The old version_array rewind code used linear stack space in order to
perform it's updates in the right order (newest to oldest) by following the
structure's next pointers (which are a oldest to newest list). I previously
introduced week prev pointers so that walking over this structure newest to
oldest could be done with constant stack space. However that is less
efficient than the method suggested by Peter Wang.
Peter suggested using a bitmap and traversing oldest-to-newest, marking
each update in the bitmap and checking the bitmap before making any update.
Thus preserving older values over newer ones (which is good, this code
_rewinds_ updates). This patch implements Peter's suggestion and removes
the prev pointers from the structure for C and Java backends.
Thanks to Peter Wang for giving me a hand with C#.
library/version_array.m:
As above.
runtime/mercury_bitmap.h:
Add some macros for initialising bitmaps and testing, setting and clearing
their bits.
library/bitmap.m:
java/runtime/MercuryBitmap.java:
Move the Java MercuryBitmap class into the runtime library. This makes
it easier for other standard library modules to use this Java class.
library/bitmap.m:
runtime/mercury_dotnet.cs.in:
Move C# MercuryBitmap class into runtime/mercury_dotnet.cs
library/bitmap.m:
Add extra methods to the C# MercuryBitmap class.
tests/hard_coded/version_array_test.exp:
tests/hard_coded/version_array_test.m:
Ensure that the test verifies that rolling back updates to a version
array rolls back changes in the correct order: If two updates modify the
same cell, then the older one should be visible in the result.
Use longer arrays so that the bitmap used in the rollback code is more
than one byte in length.
Although rewinding version arrays should be rare it is better if this code
uses constant stack space to avoid crashes. Currently the list of updates
made in a version array is kept in a singly linked list. This list needs to
be walked backwards to unwind updates, such as when updating an old version
of an array (to fork into two separate arrays). The stack is used to
perform this backwards work and can overflow for long histories.
This patch makes these lists doubly-linked so that they can be traversed in
either direction. The back pointers are implemented using weak pointers in
all backends. This avoids unnecessary memory retention when a programmer
only maintains a reference to the lastest version of the array, which is the
common case.
library/version_array.m:
As above; I developed this algorithm in the C implementation first and
then replicated the changes in the Java and C# implementations.
tests/hard_coded/version_array_test.m:
tests/hard_coded/version_array_test.exp:
Extend the test case to exercise implicitly unwinding a version array by
updating an old version of an array. Note that the implicit and
explicit unwind codepaths are different as they are out-of-place and
in-place respectively.
library/array.m:
library/version_array.m:
Add the above predicates.
NEWS:
Announce the new predicates.
tests/hard_coded/Mmakefile:
tests/hard_coded/array_all_tf.{m,exp}:
Test the new predicates.
tests/hard_coded/version_array_test.{m,exp}:
Extend this test case to cover the new predicates.
Estimated 3ours taken: 4
Branches: main
compiler/prog_data.m:
Make vartypes an abstract data type, in preparation for exploring
better representations for it.
compiler/mode_util.m:
Provide two different versions of a predicate. The generic version
continues to use map lookups. The other version knows it works on
prog_vars, so it can use the abstract operations on them provided
by prog_data.m.
compiler/accumulator.m:
compiler/add_class.m:
compiler/add_heap_ops.m:
compiler/add_pragma.m:
compiler/add_pred.m:
compiler/add_trail_ops.m:
compiler/arg_info.m:
compiler/builtin_lib_types.m:
compiler/bytecode_gen.m:
compiler/call_gen.m:
compiler/clause_to_proc.m:
compiler/closure_analysis.m:
compiler/code_info.m:
compiler/common.m:
compiler/complexity.m:
compiler/const_prop.m:
compiler/constraint.m:
compiler/continuation_info.m:
compiler/cse_detection.m:
compiler/ctgc.datastruct.m:
compiler/ctgc.util.m:
compiler/deep_profiling.m:
compiler/deforest.m:
compiler/dep_par_conj.m:
compiler/det_analysis.m:
compiler/det_report.m:
compiler/det_util.m:
compiler/disj_gen.m:
compiler/equiv_type_hlds.m:
compiler/erl_call_gen.m:
compiler/erl_code_gen.m:
compiler/erl_code_util.m:
compiler/exception_analysis.m:
compiler/float_regs.m:
compiler/follow_vars.m:
compiler/format_call.m:
compiler/goal_path.m:
compiler/goal_util.m:
compiler/hhf.m:
compiler/higher_order.m:
compiler/hlds_clauses.m:
compiler/hlds_goal.m:
compiler/hlds_out_goal.m:
compiler/hlds_out_pred.m:
compiler/hlds_pred.m:
compiler/hlds_rtti.m:
compiler/inlining.m:
compiler/instmap.m:
compiler/intermod.m:
compiler/interval.m:
compiler/lambda.m:
compiler/lco.m:
compiler/live_vars.m:
compiler/liveness.m:
compiler/lookup_switch.m:
compiler/mercury_to_mercury.m:
compiler/ml_accurate_gc.m:
compiler/ml_closure_gen.m:
compiler/ml_code_gen.m:
compiler/ml_code_util.m:
compiler/ml_disj_gen.m:
compiler/ml_lookup_switch.m:
compiler/ml_proc_gen.m:
compiler/ml_unify_gen.m:
compiler/mode_info.m:
compiler/modecheck_call.m:
compiler/modecheck_conj.m:
compiler/modecheck_goal.m:
compiler/modecheck_unify.m:
compiler/modecheck_util.m:
compiler/modes.m:
compiler/par_loop_control.m:
compiler/pd_info.m:
compiler/pd_util.m:
compiler/polymorphism.m:
compiler/post_typecheck.m:
compiler/prog_type_subst.m:
compiler/prop_mode_constraints.m:
compiler/purity.m:
compiler/qual_info.m:
compiler/rbmm.points_to_info.m:
compiler/rbmm.region_liveness_info.m:
compiler/rbmm.region_transformation.m:
compiler/saved_vars.m:
compiler/simplify.m:
compiler/size_prof.m:
compiler/ssdebug.m:
compiler/stack_alloc.m:
compiler/stack_opt.m:
compiler/store_alloc.m:
compiler/structure_reuse.analysis.m:
compiler/structure_reuse.direct.choose_reuse.m:
compiler/structure_reuse.direct.detect_garbage.m:
compiler/structure_reuse.indirect.m:
compiler/structure_sharing.analysis.m:
compiler/structure_sharing.domain.m:
compiler/switch_detection.m:
compiler/table_gen.m:
compiler/term_constr_build.m:
compiler/term_constr_util.m:
compiler/term_traversal.m:
compiler/term_util.m:
compiler/trace_gen.m:
compiler/trailing_analysis.m:
compiler/try_expand.m:
compiler/tupling.m:
compiler/type_constraints.m:
compiler/type_util.m:
compiler/typecheck.m:
compiler/typecheck_errors.m:
compiler/typecheck_info.m:
compiler/unify_gen.m:
compiler/unify_proc.m:
compiler/unique_modes.m:
compiler/untupling.m:
compiler/unused_args.m:
compiler/var_locn.m:
Conform to the above.
compiler/prog_type.m:
compiler/rbmm.points_to_graph.m:
Conform to the above.
Move some comments where they belong.
compiler/stm_expand.m:
Conform to the above.
Do not export a predicate that is not used outside this module.
Disable some debugging output unless it is asked for.
Remove unnecessary prefixes on variable names.
library/version_array.m:
Instead writing code for field access lookalike functions and defining
lookup, set etc in terms of them, write code for lookup, set etc,
and define the field access lookalike functions in terms of them.
Change argument orders of some internal predicates to be
more state variable friendly.
Fix typos in comments.
tests/hard_coded/version_array_test.exp:
Conform to the change to version_array.m.
Branches: main, 11.07
library/array2d.m:
When implementing unsafe array2d operations call the
corresponding unsafe operations in the array module.
tests/hard_coded/version_array_test.exp:
Conform to recent changes to the version_array module.
Estimated hours taken: 0.5
Branches: main
library/version_array.m:
Fix a bug which caused negative indices to be allowed
when updating a version_array.
tests/hard_coded/version_array_test.{m,exp}:
Add test cases.
Estimated hours taken: 80
Branches: main
Improvements for bitmap.m, to make it useable as a general container
for binary data.
library/bitmap.m:
runtime/mercury_bitmap.c:
runtime/mercury_bitmap.h:
Specialize the representation of bitmaps to an array of unsigned
bytes defined as a foreign type.
This is better than building on top of array(int) because it:
- is better for interfacing with foreign code
- has a more sensible machine-independent comparison order
(same as array(bool))
- avoids storing the size twice
- has more efficient copying, unification, comparison and tabling
(although we should probably specialize the handling of array(int)
and isomorphic types as well)
- uses GC_MALLOC_ATOMIC to avoid problems with bit patterns that look
like pointers (although we should do that for array(int) as well)
XXX The code for the Java and IL backends is untested.
Building the library in grade Java with Sun JDK 1.6 failed (but
at least passed error checking), and I don't have access to a
copy of MSVS.NET. The foreign code that needs to be tested is
trivial.
Add fields `bit', `bits' and `byte' to get/set a single bit,
multiple bits (from an int) or an 8 bit byte.
Add functions for converting bitmaps to hex strings and back,
for use by stream.string_writer.write and deconstruct.functor/4.
bitmap.intersect was buggy in the case where the input bitmaps
had a different size. Given that bitmaps are implemented with
a fixed domain (lookups out of range throw an exception), it
makes more sense to throw an exception in that case anyway,
so all of the set operations do that now.
The difference operation actually performed xor. Fix it and
add an xor function.
library/version_bitmap.m:
This hasn't been fully updated to be the same as bitmap.m.
The payoff would be much less because foreign code can't
really do anything with version_bitmaps.
Add a `bit' field.
Deprecate the `get/2' function in favour of the `bit' field.
Fix the union, difference, intersection and xor functions
as for bitmap.m.
Fix comparison of version_arrays so that it uses the same
method as array.m: compare size then elements in order.
The old code found version_arrays to be equal if one was
a suffix of the other.
library/char.m:
Add predicates for converting between hex digits and integers.
library/io.m:
library/stream.string_writer.m:
library/term.m:
Read and write bitmaps.
runtime/mercury_type_info.h:
runtime/mercury_deep_copy_body.h:
runtime/mercury_mcpp.h:
runtime/mercury_table_type_body.h:
runtime/mercury_tabling_macros.h:
runtime/mercury_unify_compare_body.h:
runtime/mercury_construct.c:
runtime/mercury_deconstruct.c:
runtime/mercury_term_size.c:
runtime/mercury_string.h:
library/construct.m:
library/deconstruct.m
compiler/prog_type.m:
compiler/mlds_to_gcc.m:
compiler/rtti.m:
Add a MR_TypeCtorRep for bitmaps, and handle it in the library
and runtinme.
library/Mercury.options:
Compile bitmap.m with `--no-warn-insts-without-matching-type'.
runtime/mercury_type_info.h:
Bump MR_RTTI_VERSION.
NEWS:
Document the changes.
tests/hard_coded/Mmakefile:
tests/hard_coded/bitmap_test.m:
tests/hard_coded/bitmap_simple.m:
tests/hard_coded/bitmap_tester.m:
tests/hard_coded/bitmap_test.exp:
tests/tabling/Mmakefile:
tests/tabling/expand_bitmap.m:
tests/tabling/expand_bitmap.exp:
tests/hard_coded/version_array_test.m:
tests/hard_coded/version_array_test.exp:
Test cases.
Estimated hours taken: 2
Branches: main
Added a test case for version_array.m and fixed a few bugs.
library/version_array.m:
Bug in version_array.rewind fixed.
tests/hard_coded/Mmakefile:
tests/hard_coded/version_array_test.m:
tests/hard_coded/version_array_test.exp:
Test case added.
