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29 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Peter Wang
|
2be2e7468c |
Do not use _snprintf functions directly in place of snprintf functions.
The Windows _snprintf family of functions do not guarantee null
termination when the output is truncated so cannot be used as direct
replacements for the snprintf functions. Also, the _snprintf functions
have different return values from the C99 snprintf functions when output
is truncated (like some older snprintf implementations).
Furthermore, on Windows snprintf/vsnprintf may be synonyms for
_snprintf/_vsnprintf so cannot be relied upon to terminate their outputs
either, even if the functions exist.
runtime/mercury_string.c:
runtime/mercury_string.h:
Define MR_snprintf and MR_vsnprintf as macro synonyms for
snprintf/vsnprintf ONLY if _snprintf/_vsnprintf do not exist.
Otherwise, implement MR_snprintf and MR_vsnprintf functions
that behave like the C99 functions, in terms of _vsnprintf.
Require that either snprintf/vsnprintf or _snprintf/_vsnprintf
are available. This should be true on all systems still in use.
runtime/mercury_debug.c:
runtime/mercury_ml_expand_body.h:
runtime/mercury_runtime_util.c:
runtime/mercury_stack_layout.c:
runtime/mercury_stack_trace.c:
runtime/mercury_stacks.c:
runtime/mercury_tabling.c:
runtime/mercury_threadscope.c:
runtime/mercury_trace_base.c:
runtime/mercury_wrapper.c:
trace/mercury_trace_completion.c:
trace/mercury_trace_internal.c:
trace/mercury_trace_spy.c:
trace/mercury_trace_vars.c:
bytecode/mb_disasm.c:
Use MR_snprintf instead of snprintf/_snprintf
and MR_vsnprintf instead of vsnprintf/_vsnprintf.
Drop code paths using sprintf as a fallback.
|
||
|
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.
|
||
|
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.
|
||
|
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. |
||
|
Zoltan Somogyi
|
c7ffc1c7bd | Fix a comment. | ||
|
Zoltan Somogyi
|
41e75fcc78 |
Fix breakage.
runtime/mercury_stacks.c: Fix typo. |
||
|
Zoltan Somogyi
|
f6fafa150d |
Fix Mantis bug 314 for temp frames created by nondet procedures.
Also fix some bugs in related code, and improve the related debugging
infrastructure.
-------------------
runtime/mercury_stacks.[ch]:
Fix bug 314 for temp frames created by nondet procedures. The fix will
probably also work for *det* procedures that create temp frames on the
nondet stack, but I can't think of a way to test that, because det
procedures create such frames only in very specific circumstances,
and I cannot think of a way to nest a recursive call inside those
circumstances.
The problem was that when we were creating new temp frames on
the nondet stack, we did not check whether the current nondet stack segment
had room for them. We now do.
The stack trace tracing code needs to know the size of each nondet stack
frame, since it uses the size to classify frames as temp or ordinary.
The size is given by the difference in address between the address of the
frame and the address of the previous frame. This difference would yield
an incorrect size and hence an incorrect frame classification if a temp
frame were allowed to have a frame on a different segment as its
immediate predecessor.
We prevent this by putting an ordinary (i.e. non-temp) frame at the bottom
of every new nondet stack segment as a sentinel. We hand-build this frame,
since it is not an "ordinary" ordinary frame. It is not created by a call,
so it has no meaningful success continuation, and since it does not make
any calls, no other frame's success continuation can point to it either.
If backtracking reaches this sentinel frame, we use this fact to free
all the segments beyond the one the sentinel frame is in, but keep the
frame the sentinel frame is in, since we are likely to need it again.
Document the reason why MR_incr_sp_leaf() does not have to check
whether a new stack segment is needed. (See the fix to llds_out_instr.m
below.)
runtime/mercury_stack_trace.[ch]:
When traversing the nondet stack, treat the sentinel frame specially.
We have to, since it is an ordinary frame (i.e. it is not a temp frame),
but it is not an "ordinary" ordinary frame: it does not make calls,
and hence calls cannot return to it, and it does not return to any
other frame either. It therefore does not have the layout structures
(label and proc) that the nondet stack traversal expects to find.
Fix an old bug: the nondet stack traversal used a simple directional
pointer comparison to check whether it has reached the bottom of the nondet
stack. This is NOT guaranteed to work in the presence of stack segments:
depending on exactly what addresses new stack segments get, a stack frame
can have an address BELOW the address of the initial stack frame
even if it is logically ABOVE that stack frame.
Another old bug was that a difference between two pointers, which could
be 64 bit, was stored in an int, which could be 32 bit.
The nondet stack traversal code used a similar directional comparison
to implement optionally stopping at an arbitrary point on the nondet stack.
Fixing this facility (the limit_addr parameter of MR_dump_nondet_stack)
while preserving reasonable efficiency would not be trivial, but it would
also be pointless, since the facility is not actually used. This diff
deletes the parameter instead.
Move some loop invariant code out of its loop.
trace/mercury_trace_cmd_developer.c:
trace/mercury_trace_external.c:
Don't pass the now-deleted parameter to mercury_stack_trace.c.
runtime/mercury_wrapper.c:
Record the zone of the initial nondet stack frame, since the fix
of mercury_stack_trace.c needs that info, and it is much more efficient
to set it up just once.
tests/hard_coded/bug314.{m,exp}:
The regression test for this bug.
tests/hard_coded/Mercury.options:
Compile the new test case with the options it needs.
tests/hard_coded/Mmakefile:
Enable the new test case.
-------------------
runtime/mercury_wrapper.c:
The compiler knows the number of words in a stack frame it is creating,
not necessarily the number of bytes (though it could put bounds on that
from the number of tag bits). Since this size must sync with the runtime,
change the runtime's variable holding this size to also be in words.
Note that similar changes would also be beneficial for other sizes.
compiler/llds_out_instr.m:
Conform to the change in mercury_wrapper.c, fixing an old bug
(mercury_wrapper.c reserved 128 BYTES for leaf procedures, but
llds_out_instr.m was using that space for procedures whose frames
were up to 128 WORDS in size.)
compiler/mercury_memory.c:
Conform to the change in mercury_wrapper.c.
-------------------
runtime/mercury_memory_zones.h:
Instead of starting to use EVERY zone at a different offset, do this
only for the INITIAL zones in each memory area, since only on these
is it useful. When the program first starts up, it WILL be using
the initial parts of the det stack, nondet stack and heap, so it is
useful to make sure that these do not collide in the cache. However,
when we allocate e.g. the second zone in e.g. the nondet stack, we are
no more likely to be beating on the initial part of any segment
of the det stack than on any other part of such segments.
If a new debug macro, MR_DEBUG_STACK_SEGMENTS_SET_SIZE is set (to an int),
use only that many words in each segment. This allows the segment switchover
code to be exercised and debugged with smaller test cases.
runtime/mercury_conf_param.h:
Document the MR_DEBUG_STACK_SEGMENTS_SET_SIZE macro.
Convert this file to four-space indentation with tabs expanded.
-------------------
runtime/mercury_overflow.h:
Make abort messages from overflows and underflows more useful by including
more information.
runtime/mercury_overflow.c:
Add a new function to help with the better abort messages.
Since this file did not exist before, create it.
runtime/Mmakefile:
Add the new source file to the list of source files.
-------------------
runtime/mercury_debug.[ch]:
Fix problems with the formatting of the debugging output from existing
functions.
Add new functions for dumping info about memory zones.
Factor out some common code.
Convert the header file to four-space indentation.
-------------------
runtime/mercury_grade.c:
Generate an error if stack segments are specified together with stack
extension
-------------------
trace/.gitignore:
util/.gitignore:
tests/debugger/.gitignore:
List some more files.
-------------------
runtime/mercury_context.c:
runtime/mercury_engine.[ch]:
runtime/mercury_misc.h:
compiler/notes/failure.html:
Fix white space.
|
||
|
Peter Wang
|
7e26b55e74 |
Implement a new form of memory profiling, which tells the user what memory
Branches: main
Implement a new form of memory profiling, which tells the user what memory
is being retained during a program run. This is done by allocating an extra
word before each cell, which is used to "attribute" the cell to an
allocation site. The attribution, or "allocation id", is an address to an
MR_AllocSiteInfo structure generated by the Mercury compiler, giving the
procedure, filename and line number of the allocation, and the type
constructor and arity of the cell that it allocates.
The user must manually instrument the program with calls to
`benchmarking.report_memory_attribution', which forces a GC and summarises
the live objects on the heap using the attributions. The mprof tool is
extended with a new mode to parse and present that data.
Objects which are unattributed (e.g. by hand-written C code which hasn't
been updated) are still accounted for, but show up in profiles as "unknown".
Currently this profiling mode only works in conjunction with the Boehm
garbage collector, though in principle it can work with any memory allocator
for which we can access a list of the live objects. Since term size
profiling relies on the same technique of using an extra word per memory
cell, the two profiling modes are incompatible.
The output from `mprof -s' looks like this:
------ [1] some label ------
cells words cumul procedure / type (location)
14150 38872 total
* 1949/ 13.8% 4872/ 12.5% 12.5% <predicate `parser.parse_rest/7' mode 0>
975/ 6.9% 1950/ 5.0% list.list/1 (parser.m:502)
487/ 3.4% 1948/ 5.0% term.term/1 (parser.m:501)
487/ 3.4% 974/ 2.5% term.const/0 (parser.m:501)
* 1424/ 10.1% 4272/ 11.0% 23.5% <predicate `parser.parse_simple_term_2/6' mode 0>
708/ 5.0% 2832/ 7.3% term.term/1 (parser.m:643)
708/ 5.0% 1416/ 3.6% term.const/0 (parser.m:643)
...
boehm_gc/alloc.c:
boehm_gc/include/gc.h:
boehm_gc/misc.c:
boehm_gc/reclaim.c:
Add a callback function to be called for every live object after a GC.
Add a function to write out the GC_size_map array.
compiler/layout.m:
Define the alloc_site_info type which is equivalent to the
MR_AllocSiteInfo C structure.
Add alloc_site_array as a kind of "layout" array.
compiler/llds.m:
Add allocation sites to `cfile' structure.
Replace TypeMsg argument (which was also for profiling) on `incr_hp'
instructions by an allocation site identifier.
Add a new foreign_proc_component for allocation site ids.
compiler/code_info.m:
compiler/global_data.m:
compiler/proc_gen.m:
Keep the set of allocation sites in the code_info and global_data
structures.
compiler/unify_gen.m:
Add allocation sites to LLDS allocation instructions.
compiler/layout_out.m:
compiler/llds_out_file.m:
compiler/llds_out_instr.m:
Output MR_AllocSiteInfo arrays in generated C files.
Output code to register the MR_AllocSiteInfo array with the Mercury
runtime.
Output allocation site ids for memory allocation instructions.
compiler/llds_out_util.m:
Add allocation sites to llds_out_info.
compiler/pragma_c_gen.m:
compiler/ml_foreign_proc_gen.m:
Generate a macro MR_ALLOC_ID which resolves to an allocation site
structure, for every foreign_proc whose C code contains the string
"MR_ALLOC_ID". This is to be used by hand-written C code which
allocates memory.
MR_PROC_LABELs are retained for backwards compatibility. Though
they were introduced for profiling, they seem to have been co-opted
for printf-debugging since then.
compiler/ml_global_data.m:
Add allocation site structures to the MLDS global data.
compiler/mlds.m:
compiler/ml_unify_gen.m:
Add allocation site id to `new_object' instruction.
compiler/mlds_to_c.m:
Output allocation site arrays and allocation ids in high-level C code.
Output a call to register the allocation site array with the Mercury
runtime.
Delete an unused predicate.
compiler/exprn_aux.m:
compiler/jumpopt.m:
compiler/livemap.m:
compiler/mercury_compile_llds_back_end.m:
compiler/middle_rec.m:
compiler/ml_accurate_gc.m:
compiler/ml_elim_nested.m:
compiler/ml_optimize.m:
compiler/ml_util.m:
compiler/mlds_to_cs.m:
compiler/mlds_to_gcc.m:
compiler/mlds_to_il.m:
compiler/mlds_to_java.m:
compiler/mlds_to_managed.m:
compiler/opt_debug.m:
compiler/opt_util.m:
compiler/use_local_vars.m:
compiler/var_locn.m:
Conform to changes.
compiler/pickle.m:
compiler/prog_event.m:
compiler/timestamp.m:
Conform to changes in memory allocation macros.
library/benchmarking.m:
Add the `report_memory_attribution' instrumentation predicates.
Conform to changes to MR_memprof_record.
library/array.m:
library/bit_buffer.m:
library/bitmap.m:
library/construct.m:
library/deconstruct.m:
library/dir.m:
library/io.m:
library/mutvar.m:
library/store.m:
library/string.m:
library/thread.semaphore.m:
library/version_array.m:
Use attributed memory allocation throughout the standard library so
that objects don't show up in the memory profile as "unknown".
Replace MR_PROC_LABEL by MR_ALLOC_ID.
mdbcomp/program_representation.m:
mdbcomp/rtti_access.m:
Replace MR_PROC_LABEL by MR_ALLOC_ID.
profiler/Mercury.options:
profiler/globals.m:
profiler/mercury_profile.m:
profiler/options.m:
profiler/output.m:
profiler/snapshots.m:
Add a new mode to `mprof' to parse and present the data from
`Prof.Snapshots' files.
Add options for the new profiling mode.
profiler/process_file.m:
Fix a typo.
runtime/mercury_conf_param.h:
#define MR_MPROF_PROFILE_MEMORY_ATTRIBUTION if memory profiling
is enabled and we are using Boehm GC.
runtime/mercury.h:
Make MR_new_object take an allocation id argument.
Conform to changes in memory allocation macros.
runtime/mercury_memory.c:
runtime/mercury_memory.h:
runtime/mercury_types.h:
Define MR_AllocSiteInfo.
Add memory allocation functions and macros which take into the
account the additional word necessary for the new profiling mode.
These should be used in preferences to the raw memory allocation
functions wherever possible so that objects do not show up in the
profile as "unknown".
Add analogues of realloc/free which take into account the offset
introduced by the attribution word.
Add function versions of the MR_new_object macros, which can't be
written in standard C. They are only used when necessary.
Add built-in allocation site ids, to be used in the runtime and
other hand-written code when context-specific ids are unavailable.
runtime/mercury_heap.h:
Make MR_tag_offset_incr_hp_msg and MR_tag_offset_incr_hp_atomic_msg
allocate an extra word when memory attribution is desired, and store
the allocation id there.
Similarly for MR_create{1,2,3}_msg.
Replace proclabel arguments in allocation macros by alloc_id
arguments.
Replace MR_hp_alloc_atomic by MR_hp_alloc_atomic_msg. It was only
used for boxing floats.
Conform to change to MR_new_object macro.
runtime/mercury_bootstrap.h:
Delete obsolete macro hp_alloc_atomic.
runtime/mercury_heap_profile.c:
runtime/mercury_heap_profile.h:
Add the code to summarise the live objects on the Boehm GC heap and
writes out the data to `Prof.Snapshots', for display by mprof.
Don't store the procedure name in MR_memprof_record: the procedure
address is enough and faster to compare.
runtime/mercury_prof.c:
Finish and close the `Prof.Snapshots' file when the program
terminates.
Conform to changes in MR_memprof_record.
runtime/mercury_misc.h:
Add a macro to expand to the name of the allocation sites array
in LLDS grades.
runtime/mercury_bitmap.c:
runtime/mercury_bitmap.h:
Pass allocation id through bitmap allocation functions.
Delete unused function MR_string_to_bitmap.
runtime/mercury_string.h:
Add MR_make_aligned_string_copy_msg.
Make string allocation macros take allocation id arguments.
runtime/mercury.c:
runtime/mercury_array_macros.h:
runtime/mercury_context.c:
runtime/mercury_deconstruct.c:
runtime/mercury_deconstruct_macros.h:
runtime/mercury_dlist.c:
runtime/mercury_engine.c:
runtime/mercury_float.h:
runtime/mercury_hash_table.c:
runtime/mercury_ho_call.c:
runtime/mercury_label.c:
runtime/mercury_prof_mem.c:
runtime/mercury_stacks.c:
runtime/mercury_stm.c:
runtime/mercury_string.c:
runtime/mercury_thread.c:
runtime/mercury_trace_base.c:
runtime/mercury_trail.c:
runtime/mercury_type_desc.c:
runtime/mercury_type_info.c:
runtime/mercury_wsdeque.c:
Use attributed memory allocation throughout the runtime so that
objects don't show up in the profile as "unknown".
runtime/mercury_memory_zones.c:
Attribute memory zones to the Mercury runtime.
runtime/mercury_tabling.c:
runtime/mercury_tabling.h:
Use attributed memory allocation macros for tabling structures.
Delete unused MR_table_realloc_* and MR_table_copy_bytes macros.
runtime/mercury_deep_copy_body.h:
Try to retain the original attribution word when copying values.
runtime/mercury_ml_expand_body.h:
Conform to changes in memory allocation macros.
runtime/mercury_tags.h:
Replace proclabel arguments by alloc_id arguments in allocation macros.
runtime/mercury_wrapper.c:
If memory attribution is enabled, tell Boehm GC that pointers may be
displaced by an extra word.
trace/mercury_trace.c:
trace/mercury_trace_tables.c:
Conform to changes in memory allocation macros.
extras/net/tcp.m:
extras/solver_types/library/any_array.m:
extras/trailed_update/tr_array.m:
Conform to changes in memory allocation macros.
doc/user_guide.texi:
Document the new profiling mode.
doc/reference_manual.texi:
Update a commented out example.
|
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|
Paul Bone
|
ca7878f01a |
Make improvements to stack segments code.
The main benefits of these changes are:
Stack segments (and other memory zones) are cached when they are released
and can be re-used.
Some thread safety-fixes have been added.
All stack segments on all stacks are now the same size:
Small contexts (which had small stacks) aren't used with stack
segments.
The first segment on any stack is the same size as any other segment.
The first segment on any stack no-longer has a redzone.
Hard zones on all memory zones have been set to the minimum of one page
rather than one MR_unit which is usually two pages.
The caching of stack segments results in the following benchmark results. The
benefit is negligible under normal circumstances, but becomes important when
small segment sizes are used. Small segment sizes are common in
asm_fast.gc.par.stseg configurations as they reduce the memory required for
suspended contexts.
Non-segmented stack (32MB)
asm_fast.gc average of 5 with ignore=1 18.16 (1.00)
With 512KB (normal) segments:
asm_fast.gc.stseg and NO caching average of 5 with ignore=1 19.20 (1.06)
asm_fast.gc.stseg WITH caching average of 5 with ignore=1 19.16 (1.06)
With 4KB segments:
asm_fast.gc.stseg and NO caching average of 5 with ignore=1 20.66 (1.14)
asm_fast.gc.stseg WITH caching average of 5 with ignore=1 19.66 (1.08)
Other changes include corrections in code comments, clearer function names and
a documentation fix.
runtime/mercury_memory_zones.h:
runtime/mercury_memory_zones.c:
Re-write a lot of the code that managed the zone lists. The old code did
not re-use previously allocated but saved zones. The changes ensure that
MR_create_or_reuse_zone (formerly MR_create_zone) checks for a free zone
of at least the required size before allocating a new one. When zones are
released they are put on the free list.
As above MR_create_zone is now MR_create_or_reuse_zone,
MR_unget_zone is now MR_release_zone.
MR_construct_zone has been removed, it was only ever called by
MR_create_or_reuse_zone. MR_create_or_reuse_zone now contains the code for
MR_construct_zone.
To avoid an unnecessary sychronisation in parallel code some zones are not
added to the used list. The only zones put on the used list are those that
are useful to have on the used list because they have a non-default signal
handler or a redzone.
Updates to used_memory_zones now use a pthread mutex so that only one
thread may be updating the list at once. This lock is shared with the
free_memory_zones structure.
Updates to used_memory_zones now use memory barriers to guarantee that
concurrent reads always read a consistent, but possibly incomplete,
data-structure. This is necessary because it is read from a signal handler
which cannot call pthread_mutex().
Rename MR_get_used_memory_zones() to MR_get_used_memory_zones_readonly()
and document that the zone lists may be incomplete.
Make the MR_zone_next field of the MR_MemoryZone_Struct structure volatile.
Remove MAX_ZONES, it wasn't being used anywhere.
Insert some calls to MR_debug_log_message to help with debugging.
Use the correct printf integer length modifier for MR_Unsigned values.
Rename MR_context_id_counter to zone_id_counter, protect it with a lock in
HLC thread safe grades and use atomic operations in LLC thread-safe
grades..
The offset at which we start using a memory zone is allocated in sequence
from a table. This table was protected by Mercury's global lock, this is
now a CAS operation which prevents deadlocks when using trail segment,
parallel grades.
runtime/mercury_stacks.c:
Conform to changes in mercury_memory_zones.c.
Use MR_debug_log_message for printf-style debugging rather than printf.
runtime/mercury_wrapper.h:
runtime/mercury_wrapper.c:
Remove support for the smaller sized stacks in grades with stack segments.
Disable redzones when using stack segments. The MR_(non)detstack_zone_size
variables affect the first segment on every stack. Regardless of the type
of contaxt that owns that stack.
Conform to changes in runtime/mercury_memory_zones.h.
runtime/mercury_context.h:
runtime/mercury_context.c:
Removed an extra declaration for MR_init_context_maybe_generator
Small contexts are problematic since it's unclear to the programmer which
computations will be executed on smaller contexts and therefore whether
their stacks would overflow.
Conform to changes in runtime/mercury_memory_zones.h.
Conform to changes in runtime/mercury_wrapper.h.
runtime/mercury_memory.c:
Adjust the definition of MR_unit. It is now guaranteed to be a multiple of
the page size which is required by its use in mercury_memory_zones.c
Conform to changes in mercury_wrapper.h.
runtime/mercury_engine.c:
runtime/mercury_memory_handlers.c:
runtime/mercury_trail.c:
Conform to changes in runtime/mercury_memory_zones.h.
runtime/mercury_memory_handlers.c:
Use the correct printf integer length modifier for MR_Unsigned values.
runtime/mercury_misc.c:
Print out the meaning of errno if it is nonzero in MR_fatal_error.
Use the correct printf integer length modifier for MR_Unsigned values.
runtime/mercury_atomic_ops.h:
Define MR_THREADSAFE_VOLATILE to expand to volatile when MR_THREADSAFE is
defined. Otherwise it expands to nothing.
Make memory fences macros and atomic operations available in all thread safe
grades, not just low level C grades.
doc/user_guide.texi:
Corrected the default detstack size.
|
||
|
Peter Wang
|
1d5d7406ad |
Fix bug #126. The runtime could not be built in a stack segments grade when
Branches: main Fix bug #126. The runtime could not be built in a stack segments grade when mprotect() is unavailable. runtime/mercury_stacks.c: Don't refer to the `MR_zone_redzone' field directly as it may not be defined. Use the `MR_zone_end' macro instead. |
||
|
Peter Wang
|
122579d906 |
Nondet stack segments didn't work properly using the placeholder frame trick
Branches: main Nondet stack segments didn't work properly using the placeholder frame trick at the base of nondet stack segments. i.e. when we jump to special procedure (MR_pop_nondetstack_segment) stored in the succip slot of the base frame, it should free the top stack segment, set maxfr to the correct value and jump to the real succip. However, we were reading values of maxfr and succip from the *det* stack which is clearly wrong. After fixing that, it still didn't work properly. Nondet execution seems to be too haphazard for the trick to work. MR_pop_nondetstack_segment() can be entered not only when the top stack segment can be deallocated, which complicates things. Instead, switch to a simpler method to deallocate nondet stack frames. When creating a nondet frame, we know that all stack segments above that which `maxfr' points into can be freed. In the common case, `maxfr' *will* point into the top stack segment and that can be checked with just one additional test. After deallocating excess stack segments, the new frame can be created as before. See also Mantis bug #65. runtime/mercury_stacks.h: Make `MR_nondetstack_extend_and_check' check that `maxfr' still lives on the top nondet stack segment. If not, or if a new segment is required, call `MR_nondetstack_segment_extend_slow_path'. runtime/mercury_stacks.c: Rename `MR_new_detstack_segment' to `MR_nondetstack_segment_extend_slow_path'. Make it free excess nondet stack segments. Fix a bug where `MR_NONDET_FIXED_SIZE' was added twice to the number of slots required for a new frame. Delete `MR_pop_nondetstack_segment' which is no longer used. Don't use red zones for new det and nondet stack segments. Add missing parameters to some debugging code. runtime/mercury_stack_trace.c: Delete reference to `MR_pop_nondetstack_segment'. runtime/mercury_memory_zones.c: Add sanity checks for small memory zone sizes, e.g. they may be too small to fit all of the usable zone area, red zone and cache offset. NEWS: Announce stack segment support as it should be stable now. |
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Zoltan Somogyi
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ecf1ee3117 |
Add a mechanism for growing the stacks on demand by adding new segments
Estimated hours taken: 20 Branches: main Add a mechanism for growing the stacks on demand by adding new segments to them. You can ask for the new mechanism via a new grade component, stseg (short for "stack segments"). The mechanism works by adding a test to each increment of a stack pointer (sp or maxfr). If the test indicates that we are about to run out of stack, we allocate a new stack segment, allocate a placeholder frame on the new segment, and then allocate the frame we wanted in the first place on top of the placeholder. We also override succip to make it point code that will (1) release the new segment when the newly created stack frame returns, and then (2) go to the place indicated by the original, overridden succip. For leaf procedures on the det stack, we optimize away the check of the stack pointer. We can do this because we reserve some space on each stack for the use of such stack frames. My intention is that doc/user_guide.texi and NEWS will be updated once we have used the feature ourselves for a while and it seems to be stable. runtime/mercury_grade.h: Add the new grade component. runtime/mercury_conf_param.h: Document the new grade component, and the option used to debug stack segments. runtime/mercury_context.[ch]: Add new fields to contexts to hold the list of previous segments of the det and nondet stacks. runtime/mercury_memory_zones.[ch]: Include a threshold in all zones, for use in stack segments. Set it when a zone is allocated. Restore the previous #ifdef'd out function MR_unget_zone, for use when freeing stack segments execution has fallen out of. runtime/mercury_debug.[ch]: When printing the offsets of pointers into the det and nondet stacks, print the number of the segment the pointer points into (unless it is the first, in which case we suppress this in the interest of brevity and simplicity). Make all the functions in this module take a FILE * as an input argument; don't print to stdout by default. runtime/mercury_stacks.[ch]: Modify the macros that allocate stack frames to invoke the code for adding new stack segments when we are about to run out of stack. Standardize on "nondet" over "nond" as the abbreviation referring to the nondet stack. Conform to the changes in mercury_debug.c. runtime/mercury_stack_trace.c: When traversing the stack, step over the placeholder stack frames at the bottoms of stack segments. Conform to the changes in mercury_debug.c. runtime/mercury_wrapper.[ch]: Make the default stack size small in grades that support stack segments. Standardize on "nondet" over "nond" as the abbreviation referring to the nondet stack. Conform to the changes in mercury_debug.c. runtime/mercury_memory.c: Standardize on "nondet" over "nond" as the abbreviation referring to the nondet stack. runtime/mercury_engine.[ch]: runtime/mercury_overflow.h: Standardize on "nondet" over "nond" as the abbreviation referring to the nondet stack. Convert these files to four-space indentation. runtime/mercury_minimal_model.c: trace/mercury_trace.c: trace/mercury_trace_util.c: Conform to the changes in mercury_debug.c. compiler/options.m: Add the new grade option for stack segments. compiler/compile_target_code.m: compiler/handle_options.m: Add the new grade component, and handle its exclusions with other grade components and optimizations. compiler/llds.m: Extend the incr_sp instruction to record whether the stack frame is for a leaf procedure. compiler/llds_out.m: Output the extended incr_sp instruction. compiler/proc_gen.m: Fill in the extra slot in incr_sp instructions. compiler/goal_util.m: Provide a predicate for testing whether a procedure body is a leaf. compiler/delay_slot.m: compiler/dupelim.m: compiler/dupproc.m: compiler/exprn_aux.m: compiler/frameopt.m: compiler/global_data.m: compiler/jumpopt.m: compiler/middle_rec.m: compiler/opt_debug.m: compiler/opt_util.m: compiler/peephole.m: compiler/reassign.m: compiler/use_local_vars.m: Conform to the change in llds.m. scripts/canonicate_grade.sh-subr: scripts/init_grade_options.sh-subr: scripts/parse_grade_options.sh-subr: scripts/final_grade_options.sh-subr: scripts/mgnuc.in: Handle the new grade component. Convert parse_grade_options.sh-subr to four-space indentation. Mmake.workspace: Fix an old bug that prevented bootcheck from working in the new grade: when computing the gc grade, use the workspace's version of ml (which in this case understands the new grade components), rather than the installed ml (which does not). (This was a devil to track down, because neither make --debug nor strace on make revealed how the installed ml was being invoked, and there was no explicit invocation in the Makefile either; the error message appeared to come out of thin air just before the completion of the stage 2 library. It turned out the invocation happened implicitly, as a result of expanding a make variable.) |
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Zoltan Somogyi
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e404069258 |
Provide better error messages when minimal model code cannot be evaluated
Estimated hours taken: 3 Branches: main Provide better error messages when minimal model code cannot be evaluated due to the limits of our current program transformation technique. runtime/mercury_stacks.[ch]: Add an extra argument, a string, to MR_pneg_enter_else. If MR_pneg_enter_else has to abort, print this string first. compiler/ite_gen.m: When generating the wrappers around possibly negated contexts, add an argument to MR_pneg_enter_else that gives the current context. library/std_util.m: Add the argument to a hand-written call to MR_pneg_enter_else. tests/.mgnuc_opts: New file that turns off the searching of the standard (i.e. the installed) directories for header files. It is needed because without it, gcc would find the old, no-argument MR_pneg_enter_else declaration in the installed mercury_stacks.h. This is ok because the already existing .mgnuc_copts file tells gcc to look for header files in the relevant stage directories. tools/bootcheck: Copt tests/.mgnuc_opts to the various test directories. tests/tabling/consumer_in_solutions.exp: Update the expected output of this test case. |
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Zoltan Somogyi
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1ed891b7b1 |
Introduce a mechanism for extending the det and nondet stacks when needed.
Estimated hours taken: 24
Branches: main
Introduce a mechanism for extending the det and nondet stacks when needed.
The mechanism takes the form of a new grade component, .exts ("extend stacks").
While the new mechanism may be useful in its own right, it is intended mainly
to support a new implementation of minimal model tabling, which will use a
separate Mercury context for each distinct subgoal. Each context has its own
det and nondet stack. Clearly, we can't have hundreds of contexts each with
megabyte sized det stacks. The intention is that the stacks of the subgoals
will start small, and be expanded when needed.
The runtime expansion of stacks doesn't work yet, but it is unnecessarily
hard to debug without an installed compiler that understands the new grade
component, which is why this diff will be committed before that is fixed.
compiler/handle_options.m:
compiler/options.m:
runtime/mercury_grade.h:
scripts/canonical_grade.sh-subr
scripts/init_grade_options.sh-subr
scripts/parse_grade_options.sh-subr
scripts/mgnuc.in
Handle the new grade component.
runtime/mercury_memory_zones.h:
Add MR_ prefixes to the names of the fields of the zone structure.
Record not just the actual size of each zone, which includes various
kinds of buffers, but also the desired size of the zone exclusive of
buffers.
Format the documentation of the zone structure fields more
comprehensibly.
runtime/mercury_memory_zones.c:
Instead of implementing memalign if it is not provided by the operating
system, implement a function that allows us to reallocate the returned
area of memory.
Provide a prototype implementation of memory zone extension. It doesn't
work yet.
Factor out the code for setting up redzones, since it is now needed
in more than place.
Convert to four space indentation.
Make the debugging functions a bit more flexible.
runtime/mercury_wrapper.c:
Conform to the improved interface of the debugging functions.
runtime/mercury_overflow.h:
runtime/mercury_std.h:
Move a generally useful macro from mercury_overflow.h to mercury_std.h.
runtime/mercury_stacks.c:
Add functions to extend the stacks.
runtime/mercury_stacks.h:
Add the tests required to invoke the functions that extend the stacks.
Add the macros needed by the change to compiler/llds.m.
Convert to four space indentation.
runtime/mercury_conf.h.in:
Prepare for the use of the posix_memalign function, which is the
current replacement of the obsolete memalign library function.
We don't yet use it.
runtime/mercury_context.h:
Format the documentation of the context structure fields more
comprehensibly.
Put MR_ prefixes on the names of the fields of some structures
that didn't previously have them.
Conform to the new names of the fields of the zone structure.
runtime/mercury_context.c:
runtime/mercury_debug.c:
runtime/mercury_deep_copy.c:
runtime/mercury_engine.c:
runtime/mercury_memory_handlers.c:
library/benchmarking.m:
library/exception.m:
Conform to the new names of the fields of the zone structure.
In some cases, add missing MR_ prefixes to function names
and/or convert to four space indentation.
runtime/mercury_engine.h:
Add a new low level debug flag for debugging stack extensions.
Format the documentation of the engine structure fields more
comprehensibly.
Convert to four space indentation.
runtime/mercury_conf_param.h:
Document a new low level debug flag for debugging stack extensions.
compiler/compile_target_code.m:
compiler/handle_options.m:
compiler/options.m:
Handle the new grade component.
compiler/llds.m:
Add two new kinds of LLDS instructions, save_maxfr and restore_maxfr.
These are needed because the nondet stack may be relocated between
saving and the restoring of maxfr, and the saved maxfr may point to
the old stack. In .exts grades, these instructions will save not a
pointer but the offset of maxfr from the start of the nondet stack,
since offsets are not affected by the movement of the nondet stack.
compiler/code_info.m:
Use the new instructions where relevant. (Some more work may be
needed on this score; the relevant places are marked with XXX.)
compiler/dupelim.m:
compiler/dupproc.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/reassign.m:
compiler/use_local_vars.m:
Handle the new LLDS instructions.
tools/bootcheck:
Provide a mechanism for setting the initial stack sizes for a
bootcheck.
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Zoltan Somogyi
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e854a5f9d9 |
Major improvements to tabling, of two types.
Estimated hours taken: 32
Branches: main
Major improvements to tabling, of two types. The first is the implementation
of the loopcheck and memo forms of tabling for model_non procedures, and the
second is a start on the implementation of a new method of implementing
minimal model tabling, one that has the potential for a proper fix of the
problem that we currently merely detect with the pneg stack (the detection
is followed by a runtime abort). Since this new method relies on giving each
own generator its own stack, the grade component denoting it is "mmos"
(minimal model own stack). The true name of the existing method is changed
from "mm" to "mmsc" (minimal model stack copy). The grade component "mm"
is now a shorthand for "mmsc"; when the new method works, "mm" will be changed
to be a shorthand for "mmos".
configure.in:
scripts/canonical_grade.sh-subr:
scripts/init_grade_options.sh-subr:
scripts/parse_grade_options.sh-subr:
scripts/final_grade_options.sh-subr:
compiler/options.m:
Handle the new way of handling minimal model grades.
scripts/mgnuc.in:
compiler/compile_target_code.m:
Conform to the changes in minimal model grade options.
compiler/table_gen.m:
Implement the transformations required by the loopcheck and memo
tabling of model_non procedures, and the minimal model own stack
transformation.
The new implementation transformations use foreign_procs with extra
args, since there is no point in implementing them both that way and
with separate calls to library predicates. This required making the
choice of which method to use at the top level of each transformation.
Fix an oversight that hasn't caused problems yet but may in the future:
mark goals wrapping the original goals as not impure for determinism
computations.
compiler/handle_options.m:
Handle the new arrangement of the options for minimal model tabling.
Detect simultaneous calls for both forms of minimal model tabling,
and generate an error message. Allow for more than one error message
generated at once; report them all once rather than separately.
compiler/globals.m:
Add a mechanism to allow a fix a problem detected by the changes
to handle_options: the fact that we currently may generate a usage
message more than once for invocations with more than one error.
compiler/mercury_compile.m:
compiler/make.program_target.m:
compiler/make.util.m:
Use the new mechanism in handle_options to avoid generating duplicate
usage messages.
compiler/error_util.m:
Add a utility predicate for use by handle_options.
compiler/hlds_pred.m:
Allow memo tabling for model_non predicates, and handle own stack
tabling.
compiler/hlds_out.m:
Print information about the modes of the arguments of foreign_procs,
since this is useful in debugging transformations such as tabling
that generate them.
compiler/prog_data.m:
compiler/layout_out.m:
compiler/prog_out.m:
runtime/mercury_stack_layout.h:
Mention the new evaluation method.
compiler/goal_util.m:
Change the predicates for creating calls and foreign_procs to allow
more than one goal feature to be attached to the new goal. table_gen.m
now uses this capability.
compiler/add_heap_ops.m:
compiler/add_trail_ops.m:
compiler/polymorphism.m:
compiler/simplify.m:
compiler/size_prof.m:
compiler/typecheck.m:
compiler/unify_proc.m:
Conform to the changes in goal_util.
compiler/code_info.m:
compiler/make_hlds.m:
compiler/modules.m:
compiler/prog_io_pragma.m:
Conform to the new the options controlling minimal model
tabling.
compiler/prog_util.m:
Add a utility predicate for use by table_gen.m.
library/std_util.m:
Conform to the changes in the macros for minimal model tabling grades.
library/table_builtin.m:
Add the types and predicates required by the new transformations.
Delete an obsolete comment.
runtime/mercury_grade.h:
Handle the new minimal model grade component.
runtime/mercury_conf_param.h:
List macros controlling minimal model grades.
runtime/mercury_tabling.[ch]:
Define the types needed by the new transformations,
Implement the performance-critical predicates that need to be
hand-written for memo tabling of model_non predicates.
Add utility predicates for debugging.
runtime/mercury_tabling_preds.h:
Add the implementations of the predicates required by the new
transformations.
runtime/mercury_mm_own_stacks.[ch]:
This new module contains the first draft of the implementation
of the own stack implementation of minimal model tabling.
runtime/mercury_imp.h:
Include the new file if the grade needs it.
runtime/Mmakefile:
Mention the new files, and sort the lists of filenames.
runtime/mercury_tabling_macros.h:
Add a macro for allocating answer blocks without requiring them to be
pointed to directly by trie nodes.
runtime/mercury_minimal_model.[ch]:
The structure type holding answer lists is now in mercury_tabling.h,
since it is now also needed by memo tabling of model_non predicates.
It no longer has a field for an answer num, because while it is ok
to require a separate grade for debugging minimal model tabling,
it is not ok to require a separate grade for debugging memo tabling
of model_non predicates. Instead of printing the answer numbers,
print the answers themselves when we need to identify solutions
for debugging.
Change function names, macro names, error messages etc where this is
useful to distinguish the two kinds of minimal model tabling.
Fix some oversights wrt transient registers.
runtime/mercury_context.[ch]:
runtime/mercury_engine.[ch]:
runtime/mercury_memory.[ch]:
runtime/mercury_wrapper.[ch]:
With own stack tabling, each subgoal has its own context, so record
the identity of the subgoal owning a context in the context itself.
The main computation's context is the exception: it has no owner.
Record not just the main context, but also the contexts of subgoals
in the engine.
Add variables for holding the sizes of the det and nondet stacks
of the contexts of subgoals (which should in general be smaller
than the sizes of the corresponding stacks of the main context),
and initialize them as needed.
Initialize the variables holding the sizes of the gen, cut and pneg
stacks, even in grades where the stacks are not used, for safety.
Fix some out-of-date documentation, and conform to our coding
guidelines.
runtime/mercury_memory_zones.[ch]:
Add a function to test whether a pointer is in a zone, to help
debugging.
runtime/mercury_debug.[ch]:
Add some functions to help debugging in the presence of multiple
contexts, and factor out some common code to help with this.
Delete the obsolete, unused function MR_printdetslot_as_label.
runtime/mercury_context.h:
runtime/mercury_bootstrap.h:
Move a bootstrapping #define from mercury_context.h to
mercury_bootstrap.h.
runtime/mercury_context.h:
runtime/mercury_bootstrap.h:
Move a bootstrapping #define from mercury_context.h to
mercury_bootstrap.h.
runtime/mercury_types.h:
Add some more forward declarations of type names.
runtime/mercury_dlist.[ch]:
Rename a field to avoid assignments that dereference NULL.
runtime/mercury_debug.c:
runtime/mercury_memory.c:
runtime/mercury_ml_expand_body.h:
runtime/mercury_stack_trace.c:
runtime/mercury_stacks.[ch]:
trace/mercury_trace_util.c
Update uses of the macros that control minimal model tabling.
runtime/mercury_stack_trace.c:
Provide a mechanism to allow stack traces to be suppressed entirely.
The intention is that by using this mechanism, by the testing system
won't have to provide separate .exp files for hlc grades, nondebug
LLDS grades and debug LLDS grades, as we do currently. The mechanism
is the environment variable MERCURY_SUPPRESS_STACK_TRACE.
tools/bootcheck:
tools/test_mercury:
Specify MERCURY_SUPPRESS_STACK_TRACE.
trace/mercury_trace.c:
When performing retries across tabled calls, handle memo tabled
model_non predicates, for which the call table tip variable holds
a record with a back pointer to a trie node, instead of the trie node
itself.
trace/mercury_trace_internal.c:
When printing tables, handle memo tabled model_non predicates. Delete
the code now moved to runtime/mercury_tabling.c.
Add functions for printing the data structures for own stack minimal
model tabling.
tests/debugger/print_table.{m,inp,exp}:
Update this test case to also test the printing of tables for
memo tabled model_non predicates.
tests/debugger/retry.{m,inp,exp}:
Update this test case to also test retries across memo tabled
model_non predicates.
tests/tabling/loopcheck_nondet.{m,exp}:
tests/tabling/loopcheck_nondet_non_loop.{m,exp}:
New test cases to test loopcheck tabled model_non predicates.
One test case has a loop to detect, one doesn't.
tests/tabling/memo_non.{m,exp}:
tests/tabling/tc_memo.{m,exp}:
tests/tabling/tc_memo2.{m,exp}:
New test cases to test memo tabled model_non predicates.
One test case has a loop to detect, one has a need for minimal model
tabling to detect, and the third doesn't have either.
tests/tabling/Mmakefile:
Add the new test cases, and reenable the existing tc_loop test case.
Rename some make variables and targets to make them better reflect
their meaning.
tests/tabling/test_mercury:
Conform to the change in the name of the make target.
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Zoltan Somogyi
|
8190c16181 |
Get Mercury to work with gcc 3.4. This required fixing several problems.
Estimated hours taken: 16 Branches: main Get Mercury to work with gcc 3.4. This required fixing several problems. One problem that caused errors is that gcc 3.4 is smart enough to figure out that in LLDS grades with gcc gotos, the C functions containing our code are not referred to, and so it optimizes them away. The fix is to ensure that mercury_<module>_init is defined always to call those functions, even if the macro that usually controls this, MR_MAY_NEED_INITIALIZATION, is not defined. The mercury_<module>_init won't be called from the init_modules function in the program's _init.c file, so there is no impact on initialization time, but gcc doesn't know this when compiling a module's .c file, so it doesn't optimize away the code we need. The cost of this change is thus only a small amount of code space. It is worth paying this cost even with compilers other than gcc 3.4 for simplicity. Actually, this size increase seems to be slightly smaller than the size reduction due to the better optimization capabilities of gcc 3.4 compared to gcc 3.2.2. A second problem is that gcc 3.4 warns about casts in lvalues being a deprecated feature. This gave lots of warnings, since we used to define several Mercury abstract machine registers, including MR_succip, MR_hp, MR_sp, MR_maxfr and MR_curfr using lvalue casts. The fix is to have two macros for each of these abstract machine registers, one of type MR_Word that you can assign to (e.g. MR_sp_word), and one of the original type that is of the right type but not an lvalue (e.g. MR_sp). The lvalue itself can't be made the right type, because MR_sp isn't a variable in its own right, but possibly defined to be a machine register. The machine register could made the right type, but only at the cost of a lot of complexity. This problem doesn't apply to the special-purpose Mercury abstract machine registers that can't be allocated to machine registers. Instead of #defining these to slots in MR_fake_reg, we make them global variables of the natural type. This should also make it easier to debug code using these registers. We treat these global variables as if they were machine registers in that MR_save_registers copies values from these global variables to slots reserved for them in the MR_fake_reg array, to allow code to loop over all Mercury abstract machine registers. These saved slots must of course be of type MR_Word, so we again need two macros to refer to them, a lvalue of type MR_Word and an rvalue with the right type. A third problem is that gcc 3.4 warns about conditionals in lvalues being a deprecated feature. This gave a few warnings, since we used to define MR_virtual_reg and MR_saved_reg using lvalues using conditionals. The fix is to have one macro (MR_virtual_reg_value) for use in rvalues and a separate macro which uses an if-then-else instead of a conditional expression (MR_virtual_reg_assign), for assignments. A fourth problem is that gcc 3.4 warns about comma operators in lvalues being a deprecated feature. This gave warnings in the few places where we refer to MR_r(N) for values of N that can map to fake registers directly, since in those cases we preceded the reference to the fake_reg array with a range check of the array index. The fix to this is to move the test to compile time for compiler-generated code. Hand-written code never refers to MR_r(N) for these values, and is very unlikely to do so in the future; instead, it refers to the underlying fake_reg array directly, since that way it doesn't have to worry about which fake registers have their own MR_rN macro and which don't. Therefore no check mechanism for hand-written code is necessary. This change mean that changing the number of MR_rN registers now requires change to the compiler as well as to the runtime system. A fifth problem is that gcc 3.4 by default assumes -fstrict-aliasing at -O2. Since we cast between integers and pointers of different types all the time, and changing that is not practical, at least in the short term, we need to disable -fstrict-aliasing when we enable -O2. NEWS: Note that Mercury now works with gcc 3.4. configure.in: scripts/mgnuc.in: Detect whether the compiler supports -fstrict-aliasing, and if so, whether it assumes it by default with -O2. If the answer is yes to both, make mgnuc specify -fno-strict-aliasing when it specifies -O2. By including it in CFLAGS_FOR_OPT, which gets put into Mercury.config, we also get -f-no-strict-aliasing when mmc invokes the C compiler directly. compiler/llds_out.m: Don't generate #ifdef MR_MAY_NEED_INITIALIZATION around the definitions and calls to the bunch functions, which call the functions we don't want the C compiler to optimize away. Generate the newly required lvalues on the left sides of assignments. We still have code to generate LVALUE_CASTs in some cases, but I don't think those cases ever arise. Add a compile-time check of register numbers. Ideally, the code generator should use stack slots instead of registers beyond the max number, but I don't recall us ever bumping into this limit by accident. compiler/fact_table.m: Use the newly required lvalues on the left sides of assignments in some hand-written C code included in generated .c files. runtime/mercury_regs.h: Make the changes described above to fix the second, third and fourth problems. We still use comma operators in lvalues when counting references to registers, but it is OK to require anyone who wants to enable this feature to use a compiler version that supports comma operators in lvalues or to ignore the warnings. Use the same mapping from Mercury abstract machine registers to the register count array as to the MR_fake_reg array. Have this mapping depend as little as possible on whether we need a real machine register to store MR_engine base, even if it costs a wasted slot in MR_fake_reg. Fix an old inconsistency: treat the Mercury abstract machine registers used for trailing the same way as the other Mercury abstract machine registers, by making MR_save_registers/MR_restore_registers copy them to and from their global variable homes. Document the requirement for the match between the runtime's and the compiler's notions of the maximum MR_rN register number. This requirement makes it harder for users to increase the number of virtual registers, but as far as I know noone has wanted to do this. Change the names of some of the macros to make them clearer. Reorder some parts of this file, and add some documentation, also in the interest of clarity. runtime/mercury_regorder.h: Delete this file after moving its contents, in much modified form, to mercury_regs.h. mercury_regorder.h was always logically part of mercury_regs.h, but was separated out to make it easier to change the mapping from Mercury abstract machine registers to machine registers. However, the cost of incompatibility caused by any such changes would be much greater that any likely performance benefit. runtime/Mmakefile: Remove the reference to mercury_regorder.h. runtime/mercury_regs.[ch]: runtime/mercury_memory_zones.[ch]: Move some functionality dealing with registers from mercury_memory_zones to mercury_regs, since it belongs there. runtime/mercury_regs.[ch]: Add a function to make it easiler to debug changes to map from Mercury abstract machine to MR_fake_reg slots. runtime/mercury_regs.[ch]: runtime/mercury_wrapper.c: Move the code to print counts of register uses from mercury_wrapper.c to mercury_regs.c. Make mercury_wrapper.c call the debugging function in mercury_regs.c if -X is specified in MERCURY_OPTIONS. runtime/mercury_bootstrap.h: Move the old MR_saved_reg and MR_virtual_reg macros from mercury_regs.h to mercury_bootstrap.h to prevent their accidental use. Since they shouldn't be used by user code, move them to the section that is not enabled by default. runtime/mercury_stacks.[ch]: Add _word versions of the macros for stack slots, for the same reason why we need them for Mercury abstract machine registers, and use them. Add global variables for the Mercury abstract machine registers for the gen, cut and pneg stacks. runtime/mercury_heap.h: Change the macros for allocating memory to assign to MR_hp_word instead of MR_hp. runtime/mercury_string.h: Change the macros for allocating strings to accomodate the updates to mercury_heap.h. Also change the expected type of the target to make it MR_String instead of MR_ConstString, since the latter requires casts in the caller. runtime/mercury_trail.h: runtime/mercury_types.h: Move the definition of the type MR_TrailEntry from mercury_trail.h to mercury_types.h, since it is now used in mercury_regs.h. runtime/mercury_accurate_gc.c: runtime/mercury_agc_debug.c: runtime/mercury_calls.h: runtime/mercury_context.[ch]: runtime/mercury_deconstruct_macros.h: runtime/mercury_deep_copy_body.h: runtime/mercury_engine.[ch]: runtime/mercury_hand_compare_body.h: runtime/mercury_hand_unify_body.h: runtime/mercury_ho_call.c: runtime/mercury_layout_util.c: runtime/mercury_make_type_info_body.h: runtime/mercury_minimal_model.c: runtime/mercury_ml_deconstruct_body.h: runtime/mercury_ml_functor_body.h: runtime/mercury_stack_layout.h: runtime/mercury_type_desc.c: runtime/mercury_type_info.c: runtime/mercury_unify_compare_body.h: runtime/mercury_wrapper.c: Conform to the changes in the rest of the runtime. In some cases, fix inconsistencies in indentation. runtime/mercury_stack_trace.c: Add some conditionally compiled debugging code controlled by the macro MR_ADDR_DEBUG, to help debug some problems with stored stack pointers. runtime/mercury_grade.h: Increment the binary compatibility version number. This is needed to avoid potential problems when a Mercury module and the debugger are compiled with different versions of the macros in mercury_regs.h. library/exception.m: Update the code that assigns to abstract machine registers. library/array.m: library/construct.m: library/dir.m: library/io.m: library/string.m: Conform to the new definitions of allocation macros. library/time.m: Delete an unnecessary #include. trace/mercury_trace.c: trace/mercury_trace_declarative.c: trace/mercury_trace_util.c: Conform to the changes in the rest of the runtime. tests/hard_coded/qual_test_is_imported.m: tests/hard_coded/aditi_private_builtin.m: Remove an unnecessary import to avoid a warning. tools/makebatch: Add an option --save-stage2-on-error, that saves the stage2 directory if a bootcheck fails. scripts/ml.in: Make ml more robust in the face of garbage files. |
||
|
Zoltan Somogyi
|
cdf0383b52 |
Fix a bunch of problems with tabling that I identified in Uppsala.
Estimated hours taken: 32
Branches: main
Fix a bunch of problems with tabling that I identified in Uppsala. These fall
into two categories.
First, the tabling transformations we were using were dividing work up
too finely. This had three bad effects. First, it caused too much time to be
spent on transmitting data to and from library predicates. Second, it made the
transformations hard to document and hard to explain in a paper. Third, it
caused us to misidentify just what the various forms of tabling have in common,
and what forms of tabling work for what determinisms. To fix this problem,
this diff reorients table_builtin.m and table_gen.m from being divided
primarily by determinism to being divided by evaluation method.
Second, we weren't being careful in separating out the parts of the tabling
data structures that are needed only for debugging the tabling system itself.
The fix for this is to introduce a new grade flag, MR_MINIMAL_MODEL_DEBUG,
intended for use by implementors only, to govern whether the tabling data
structures include debug-only components. (If this flag weren't a grade flag,
the sizes of data structures created in files with different values of this
flag could be inconsistent, which is something you don't want when debugging
the complex code of the tabling infrastructure.)
compiler/table_gen.m:
Reorganize the simple (loopcheck and memo) tabling transformations
completely. Instead of separate transformations for model_det and
model_semi predicates, have separate transformations for loopcheck
and memo predicates, since this makes it easier to see (and to ensure)
that the transformation follows the required scheme. Instead of
generating nested if-then-elses, generate switches when possible.
For model_semi loopcheck and memo predicates, generate Mercury code
that obeys our scope rules by not binding output variables in the
condition of the one remaining if-then-else.
Finetune the minimal model tabling transformation by combining some
operations where this improves clarity and performance.
Order the transformation predicates logically, and move the
documentation of each form of tabling next to the code implementing
that form of tabling.
Attach call_table_gen markers to the setup goals that now all
loopcheck, memo and minimal model tabled predicates have,
to avoid having to special case the last lookup goal, and to avoid
having to have separate code for lookups in call tables versus answer
tables.
Generate unique and more meaningful variable names. Change some
predicate names to be more meaningful, both here and in the
transformed code.
Factor out some common code, e.g. for generating lookup goals,
for generating instmap_deltas and for attaching hide_debug_event
markers to goals.
Report errors in cases where the arguments of a tabled predicate
aren't completely input or output.
compiler/hlds_pred.m:
Be more strict about the determinisms of tabled predicates; permit
only the determinisms we really support in all cases, and do not
permit the ones that may happen to work in some cases.
Conform to the change of the name of a builtin.
compiler/det_report.m:
Improve the error message for cases when the determinism is
incompatible with the selected tabling mechanism.
compiler/compile_target_code.m:
compiler/handle_options.m:
compiler/options.m:
Handle the new grade component.
library/private_builtin.m:
Provide a semipure analog of the imp predicate, a call to which makes
predicates semipure rather than impure, for use in table_builtin.m.
library/table_builtin.m:
runtime/mercury_tabling_preds.h:
Change the tabling primitives in the ways required by the changes to
the tabling transformations.
Group the primitives by the tabling methods they support, and change
their names to reflect this.
Change the implementation of each of the affected predicates to be
nothing more than the invocation of a macro defined in the new header
file runtime/mercury_tabling_preds.h. The objective of this change
is to make it possible for table_gen.m to replace sequences of calls
to predicates in table_builtin.m with a single extended foreign_proc
goal whose body just invokes the corresponding macros in sequence.
That change should improve performance by allowing the variables
that flow from one tabling primitive to another to stay in x86
registers, instead of being copied to and from Mercury abstract
machines registers, which on the x86 aren't real machine registers.
Benchmarking in Uppsala verified that this is a major cost.
Mark the foreign types used for tabling as can_pass_as_mercury_type;
this was the intended use of that assertion. Make them private to the
module, since the rest of the compiler can now handle this.
Delete the implementations of the predicates for duplicate checking
and for returning answers for completed subgoals. Profiling with gprof
has shown their performance to be critical to the performance of
minimal model tabling overall, and even with our recent changes,
the compiler still can't create optimal C code for them. They are
now implemented with handwritten code in mercury_minimal_model.c.
library/term.m:
Add two utility predicates for use by table_gen.m.
library/Mmakefile:
Since much of the implementation of table_builtin.m is now in
runtime/mercury_tabling_preds.h, make its object files depend
on that header file.
runtime/mercury_conf_params.h:
runtime/mercury_grade.h:
Include MR_MINIMAL_MODEL_DEBUG when computing the grade.
runtime/mercury_minimal_model.[ch]:
Add handwritten code to implement the predicates declared as external
in table_builtin.m.
Conform to the new names of the suspension and completion predicates.
Conform to the presence of debugging fields in tabling data structures
only if MR_MINIMAL_MODEL_DEBUG is defined.
Collect a lot more statistics than before.
Reorder some functions.
Instead of saving the whole generator stack each time, which the new
statistics showed to have O(n^2) behavior on some benchmarks, save only
the segment we need to save.
runtime/mercury_tabling.h:
Conform to the fact that loopcheck and memo predicates now have
separate sets of status values, and import mercury_tabling_preds.h.
runtime/mercury_tabling.c:
runtime/mercury_hash_lookup_or_add_body.h:
Move a huge macro out of mercury_tabling.c to the new file
mercury_hash_lookup_or_add_body.h for ease of editing, and modify it to
gather more statistics.
Make the statistics report easier to read.
runtime/Mmakefile:
Mention mercury_tabling_preds.h and mercury_hash_lookup_or_add_body.h.
runtime/mercury_wrapper.h:
Provide a mechanism (--tabling-statistics in MERCURY_OPTIONS)
that causes the runtime to print tabling statistics at the ends of
executions, for use in benchmarking.
doc/user_guide.texi:
Document --tabling-statistics. (Minimal model tabling is not yet
stable enough to be documented, which is why .dmm isn't documented
either.)
scripts/canonical_grade.sh-subr:
scripts/init_grade_options.sh-subr:
scripts/parse_grade_options.sh-subr:
scripts/mgnuc.in:
Implement the new grade component.
trace/mercury_trace.c:
trace/mercury_trace_internal.c:
Conform to changes in the runtime.
tests/debugger/*.m:
Avoid now invalid combinations of determinism and evaluation method.
tests/debugger/*.exp:
Conform to new goal paths in procedures transformed by tabling.
tests/tabling/*.m:
For tests which had predicate whose determinisms isn't compatible
with the evaluation method, change the determinism if possible,
and the evaluation method otherwise, if either is possible.
Bring these tests up to date with our coding guidelines, since they
may now appear in papers.
tests/tabling/Mmakefile:
Disable the tests whose combination of determinism and evaluation
method is no longer supported, and in which neither one can be changed.
tests/tabling/loopcheck_no_loop.{m,exp}:
Make this test case tougher.
tests/tabling/test_tabling:
Make this script more robust in the face of different kinds of
test case failures.
tests/invalid/loopcheck.{m,err_exp}:
tests/invalid/Mmakefile:
Test that we get the expected error message for an invalid combination
of determinism and evaluation method. The new test invalid/loopcheck.m
is the old test tabling/loopcheck.m.
tests/valid/Mmakefile:
Use a more general pattern to test for minimal model grades,
now that we also use .dmm as a grade component.
|
||
|
Zoltan Somogyi
|
7fda11f65a |
Our existing mechanism for detecting when the failure out of a negated context
Estimated hours taken: 8
Branches: main
Our existing mechanism for detecting when the failure out of a negated context
is due to the suspension of a consumer, and not to genuine failure was flawed
in two ways. First, it did not consider all-solutions predicates to be negated
contexts; second, in some circumstances it could rely on out-of-date data.
library/std_util.m:
Wrap predicates called in contexts where all solutions are required
with calls to the routines wrapping negated contexts. Since the
routines have empty definitions in all grades except minimal model
grades, there is extra overhead only in minimal model grades.
runtime/mercury_stacks.[ch]:
When processing suspensions of consumers in a possibly negated context
and checking that their generators are complete, disregard consumers
that have logically been deleted together with their generators
when execution reached the end of the committed-choice contexts in
which they were created. Without this change, the generator_in_commit
test case would get an unnecessary abort.
Register consumers instead of generators in pneg stack entries,
and make the generator reachable from the consumer, instead of
registering just the consumer's generator. The old arrangement
hid information that could be useful during debugging.
runtime/mercury_minimal_model.c:
Conform to the change to the mercury_stacks module.
Rename "pickling" to pruning right branches, since this expresses
the intent of the operation more directly.
Fix a bug in the printing of the addresses of the redoip slots
of pruned stack frames.
Delete unneeded code.
tests/tabling/Mmakefile:
Record the fact that we now get the expected error in the
consumer_in_solutions test case.
tests/tabling/consumer_in_solutions.{exp,exp2}:
Update the expected output in this test case. The old contents of the
.exp file is the ideal expected output, but it is not achievable with
our current approach to implementing minimal model tabling. It has
therefore been moved to the new .exp2 file.
tests/tabling/generator_in_commit.{m,exp}:
Make this test case do less computation, to make it more useful in
tracking down errors. The new version still tests everything the old
version tested, just not so many times.
|
||
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Zoltan Somogyi
|
8b9d436cbb |
More improvements for minimal model tabling.
Estimated hours taken: 12
Branches: main
More improvements for minimal model tabling.
runtime/mercury_engine.[ch]:
Provide a debug flag to control the printing of debug stack slots
in nondet stack dumps.
runtime/mercury_stack_trace.[ch]:
Provide a mechanism that allows a dump of the nondet stack to print
the principal debugging stack slots of the stack frames of procedures
that were compiled with debugging, to help debug problems where
these are overwritten during stack segment saves/restores.
Add a mechanism for limiting the output of a nondet stack trace
to a segment of the nondet stack.
runtime/mercury_minimal_model.[ch]:
Limit the output of a diagnostic nondet stack trace to just the
segment being saved or restored.
Provide a label layout structure for the entry point of the suspend
predicate, since this is necessary for correct nondet stack traces
at suspensions and resumptions.
Store the layout structure of the top nondet stack frame with each
saved state, to allow the saved nondet stack segment to be dumped
at resumptions as well as suspensions.
Fix an old bug: when extending a saved stack segment, use the same
algorithm for determining its lower bound as when the stack segment
was created in the first place.
Factor out some repeated definitions.
Note problems to be fixed later.
Improve debugging output.
runtime/mercury_stacks.[ch]:
Move the documentation of the generator stack, the cut stack and the
pneg stack from the source file to the header file, and expand it
considerably.
Make the routines for printing entries of these stacks generate more
consistently formatted output.
Simplify some code.
runtime/mercury_stack_layout.h:
Provide a macro for use by mercury_minimal_model.c.
runtime/mercury_trace_base.[ch]:
Save and restore the global variables holding event numbers,
call sequence numbers and call depths across debugging Mercury code.
We already used to do this for Mercury code invoked by the debugger,
but now that we can invoke Mercury code to print the values of
variables as diagnostics from within the suspend and resume predicates
*outside* the debugger, we need to do it more generally.
trace/mercury_trace.c:
Fix a bug: provide the layout structure of the current procedure
to the diagnostic routines for minimal model tabling even if the
debugger doesn't stop at that procedure.
trace/mercury_trace_internal.c:
Add two new mdb commands to help debug minimal model tabling.
The "mm_stack" command has the same effect as the existing commands
"gen_stack", "cut_stack" and "pneg_stack" executed in sequence.
The "debug_vars" command prints the counters for event numbers,
call sequence numbers and call depths, both from their global variables
and their saved copies, for debugging problems where they are
overwritten, such as the one fixed by the changes to
mercury_trace_base.[ch] above.
Reorder some code for consistency.
trace/mercury_trace_util.[ch]:
Add a function to implement the "debug_vars" command.
doc/user_guide.texi:
Document the new mdb commands.
doc/mdb_categories:
Add the new mdb commands to the list of developer commands, as well
some others previously left out.
tests/debugger/mdb_command_test.inp:
Test the documentation of the new mdb commands.
tests/tabling/combine.m:
Change the code of this test case to what was intended, so that it now
matches the old expected output.
tests/tabling/completed_consumer_in_solutions.{m,exp}:
New test case, an easier version of consumer_in_solutions.
tests/tabling/consumer_in_commit.{m,exp}:
Extend this test case and update the expected output; we can execute
both the original code and the extension without runtime exceptions.
tests/tabling/seq2.m:
Fix Kostis's new test case.
tests/tabling/seq4.exp:
Fix the expected output of Kostis's new test case.
tests/tabling/Mmakefile:
Enable the new test cases, and some old test cases that we now pass.
|
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|
Zoltan Somogyi
|
9489e15291 | *** empty log message *** | ||
|
Zoltan Somogyi
|
168500343c |
This change adds new facilities for debugging minimal model tabling, and
Estimated hours taken: 160 Branches: main This change adds new facilities for debugging minimal model tabling, and has several bug fixes found with the aid of those facilities. Most of the diff affects the behavior of the system only in minimal model grades and/or when debugging flags are defined. compiler/ite_gen.m: In minimal model grades, surround the conditions of if-then-elses with calls to three functions. These functions detect when a condition fails due to one or more suspensions, and abort the program. (After resumptions, the condition may actually have solutions, but by then the computation has committed to the wrong path.) compiler/table_gen.m: Change the program transformation for model_non predicates to use a switch instead of nested if-then-elses, to avoid the overhead of wrapping the condition. The version with switches is also a bit easier to debug. The transformation for model_det and model_semi predicates stays as before, because for such predicates finding the status (which we want to switch on) requires computation, not just a lookup. Switch to state variable syntax in the affected predicates. Make the error message for an internal error in loopcheck predicates more precise. Mark the code fragments that modify tabling data structures as impure and code fragments that examine tabling data structures as semipure. runtime/mercury_stacks.[ch]: Implement the new stack of possibly negated contexts that we use to detect false failures due to suspensions in negated contexts. Fix a bug: don't refer to MR_cut_stack[-1]. Shorten the name of the generator stack. runtime/mercury_context.[ch]: runtime/mercury_memory.c: runtime/mercury_wrapper.[ch]: Allocate memory for the new stack of possibly negated contexts. Use the shortened name of the generator stack. runtime/mercury_regorder.h: Allocate a pointer for the new stack of possibly negated contexts. runtime/mercury_minimal_model.[ch]: A new module holding the part of mercury_tabling.[ch] that is specific to minimal model tabling. This version contains tools to help debugging of minimal model tabling, as well as some bug fixes found with the aid of those tools. runtime/mercury_tabling.[ch]: Remove the code moved to mercury_minimal_model.[ch], and add the code moved here from trace/mercury_trace_internal.c. Add prefixes to a bunch of structure fields to make it easier to read code accessing those fields. Add mechanisms to allocate and copy tabling structures with type safety. runtime/mercury_imp.h: #include the new header file, if it is needed. runtime/Mmakefile: Mention the new module, and fix sortedness errors. runtime/mercury_stack_trace.c: Fix a bug that sometimes caused stack traces to abort in minimal model grades: they were trying to get layout information from labels that do not have them, such as do_fail. If MR_TABLE_DEBUG is defined, print the locations of stack frames when doing stack dumps. runtime/mercury_trace_base.h: Export to mercury_stack_trace.c the labels that we use to let the debugger get control at redos and fails, since they don't have layout information. runtime/mercury_types.h: Move typedefs here from mercury_tabling.h, and add typedefs for some newly added types. runtime/mercury_engine.[ch]: Add a table mapping debugging flags to their offsets in the MR_debugflag array, for use in the debugger. runtime/mercury_misc.c: Make the formatting of det stack pointers the same as nondet stack pointers in debugging output. runtime/mercury_debug.[ch]: Add conditionally compiled debugging output when creating temp frames on the nondet stack. library/table_builtin.m: Conform to the new names of some fields. Add a predicate to return the status of a subgoal. Add conditionally compiled debugging code. library/Mmakefile: Make table_builtin.m depend on runtime/mercury_minimal_model.h. trace/mercury_trace.c: Conform to the new names of some fields. trace/mercury_trace_internal.c: Add two new mdb commands, to print the cut stack and the new possibly negated context stack. Add two new mdb commands to print a subgoal and a consumer. Move some of the code to print tabling-related data structures to runtime/mercury_tabling.[ch]. Add a new mdb command to report the values of debugging flags and to set and clear them. Previously, one had to turn on these debugging flags with environment variables, which were problematic because they turned on diagnostic printouts even in Mercury programs that *weren't* being debugged, such as the Mercury compiler when being used to generate the program to be debugged. Now the flags can be turned on from a .mdbrc file, which eliminates much setting and unsetting of environment variables. doc/user_guide.tex: Document the new mdb commands. tests/debugger/mdb_command_test.inp: Test the documentation of the new mdb commands. tests/debugger/completion.exp: Expect the new commands in the command completion test. tests/debugger//nondet_stack.exp*: Expect the new format of det stack pointers. tests/debugger/all_solutions.exp3: tests/debugger/exception_value.exp3: tests/debugger/declarative/catch.exp3: tests/debugger/declarative/ho5.exp3: tests/debugger/declarative/throw.exp3: New expected test cases for use in minimal model grades. They differ from existing expected output files only in the precise phrasing of error messages. tests/debugger/declarative/Mmakefile: Disable the untraced_subgoal test case in .mm grades, since we don't pass it yet. tests/tabling/Mmakefile: Enable the mday test case, now that we pass it. |
||
|
Zoltan Somogyi
|
678fa1075f |
Add a capability for measuring statistics about the stack frame usage
Estimated hours taken: 6
Branches: main
Add a capability for measuring statistics about the stack frame usage
of a program.
configure.in:
Find out the symbolic names of the max values for the 16 and 32 bit
integer types.
runtime/mercury_conf.h.in:
Include MR_{UINT,INT}_LEAST{16,32}_MAX among the macros whose values
are determined by autoconfiguration.
runtime/mercury_conf_param.h:
Document MR_STACK_FRAME_STATS as a macro whose definition causes the
program to collect statistics on stack frame sizes.
Fix an obsolete reference: PARALLEL was renamed MR_THREAD_SAFE a long
time ago.
Document the incompatibility between MR_THREAD_SAFE and the statistics
collection flags.
runtime/mercury_stacks.h:
If MR_STACK_FRAME_STATS is defined, then record statistics every time
we create a stack frame.
runtime/mercury_stacks.c:
Define the global variables and functions needed for stack frame
statistics.
runtime/mercury_heap_profile.h:
runtime/mercury_dword.h:
Move the macros for managing 64-bit counters from
mercury_heap_profile.h to a new header file, mercury_dword.h,
since mercury_stacks.h now needs such counters too.
Rewrite the macros to make fewer assumptions, using MR_int_least64_t
and MR_int_least32_t instead of "long long" and "int".
Add expression-like forms of some of the macros for use in
mercury_stacks.h.
Rename the type MR_dword as MR_Dword.
runtime/mercury_heap_profile.c:
#include the new header file.
runtime/mercury_prof.c:
Conform to the change from MR_dword to MR_Dword.
runtime/Mmakefile:
Add the new header file to the list of header files.
runtime/mercury_wrapper.c:
If MR_STACK_FRAME_STATS is defined, initialize the stack frame stats
before execution starts and write out the statistics when execution
ends.
tools/speedtest:
Add an option that when set, causes the script to report stack frame
stats for each variant being tested.
|
||
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Zoltan Somogyi
|
090552c993 |
Make everything in the runtime use MR_ prefixes, and make the compiler
Estimated hours taken: 10 Make everything in the runtime use MR_ prefixes, and make the compiler bootstrap with -DMR_NO_BACKWARDS_COMPAT. runtime/mercury_*.[ch] Add MR_ prefixes to all functions, global variables and almost all macros that could pollute the namespace. The (intentional) exceptions are 1. some function, variable, type and label names that already start with MR_, mercury_, Mercury or _entry; 2. some standard C macros in mercury_std.h; 3. the macros used in autoconfiguration (since they are used in scripts as well as the runtime, the MR_ prefix may not be appropriate for those). In some cases, I deleted things instead of adding prefixes if the "things" were obsolete and not user visible. runtime/mercury_bootstrap.h: Provide MR_-less forms of the macros for bootstrapping and for backward compatibility for user code. runtime/mercury_debug.[ch]: Add a FILE * parameter to a function that needs it. compiler/code_info.m: compiler/export.m: compiler/fact_table.m: compiler/llds.m: compiler/llds_out.m: compiler/pragma_c_gen.m: compiler/trace.m: Add MR_ prefixes to the C code generated by the compiler. library/*.m: Add MR_ prefixes to handwritten code. trace/mercury_trace_*.c: util/mkinit.c: Add MR_ prefixes as necessary. extras/concurrency/semaphore.m: Add MR_ prefixes as necessary. |
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Tyson Dowd
|
db64a3588d |
Add MR_ prefixes to the types used when generating C code.
Estimated hours taken: 4 Add MR_ prefixes to the types used when generating C code. This means types such as Word, String, Bool, Float become MR_Word, MR_String, MR_Bool, MR_Float. Also define MR_Box for both the LLDS and MLDS backends so we can use it uniformly. This is very important in environments where String or Bool have already been used as system types (for example, managed C++). And besides, we should do it anyway as part of the grand namespace cleanup. I have fixed all of the uses of the non-prefixed types in the runtime and trace directories. I haven't done it for the library and compiler directories yet (no promises that I will do it in future either). But if you see a non-prefixed type in code from now on, please consider it a bug and fix it. mercury_bootstrap.h contains #defines to map the non-prefixed types into the prefixed ones. Like many of the other namespace cleaning backwards compatibility macros, this can be turned off with MR_NO_BACKWARDS_COMPAT. This shouldn't break any code, but this kind of change affects so many things that of course there could be problems lurking in there somewhere. If you start getting errors from the C compiler after this change is installed, you will want to make sure you at least have the runtime system updated so that you are getting the backwards compatibility definitions in mercury_bootstrap.h. Then if you continue to have problems you can bug me about it. compiler/export.m: compiler/llds_out.m: compiler/mlds_to_c.m: Use MR_Word, MR_Float, MR_Bool, etc when generating C. doc/reference_manual.texi: Update the reference manual to talk about MR_Word, MR_String, MR_Char, etc. runtime/mercury_bootstrap.h: Add bootstrapping typedefs. runtime/*: trace/*: Change Word, Float, Bool, Code, String, etc to MR_Word, MR_Float, MR_Bool, MR_Code, MR_String. |
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Zoltan Somogyi
|
1eb831eb34 |
A major cleanup of the internals of tabling.
Estimated hours taken: 40
A major cleanup of the internals of tabling.
Tabling builds up two kinds of tables, both conceptually tries. For call
tables, there is one layer in the trie for each input argument; for answer
tables, there is one layer in the trie for each output argument. However,
the way each trie node is implemented depends on the type of the relevant
argument. In addition, what is stored at the tips of the call and answer tables
also depends on what kind of tabling (e.g. loopcheck, memo, minimal model)
is being performed on the current predicate, and (in some cases) on what
stage the execution of the current predicate has reached.
Previously, all trie nodes were declared with the C type Word **, and were
cast to their actual types at the point of use, with the casts mostly being
hidden inside macros. This arrangement lacked readability and was highly
error prone. I have replaced it with a system in which trie nodes are declared
with a C type which is a pointer to a union of all the possible actual types.
There are very few casts left in the internals of the tabling system; this
change replaces them with casts at the interface (in the predicates of
private_builtin.m) and the use of the various fields of the union.
library/private_builtin.m:
Changes to conform to the changed types in mercury_tabling.h.
In some cases, improve the debugging support.
Do not table the typeinfos of polymorphic types in the
table_lookup_insert_poly predicate; since those typeinfos
are also arguments, and since they appear before the polymorphic
arguments, they have already been tabled by the time
table_lookup_insert_poly is called.
library/private_builtin.m:
library/io.m:
Add an interface to a new function in the runtime to report
statistics about the operation of the tabling system.
runtime/mercury_tabling.h:
Define and document the new types.
Add macros for allocating memory for holding one or more structures.
Make the existing macros call the versions that check for malloc
returning NULL.
runtime/mercury_tabling_macros.h:
This new file contains macros that used to be part of the file
mercury_tabling.h. The macros call the functions defined in
mercury_tabling.c, but they also optionally print debugging messages.
runtime/Mmakefile:
Add mercury_tabling_macros.h to the list of header files.
runtime/mercury_tabling.c:
Conform to the new system of C types.
Recode the hash table routines to achieve code commonality, better
debugging and statistics gathering support, much greater readability,
and the following three performance benefits:
1. The old code used open addressing to resolve collisions. In many
uses of tabling, successive searches specify keys that have
neighboring hash values, which frequently leads to very long
searches (I have observed searches that searched more than half
the slots of the hash table.) The new code uses separate chaining
to resolve collisions.
2. The old code called GC_malloc whenever it inserted a new element
into the table. The new code amortizes this overhead over a
substantial (and configurable) number of insertions.
3. In order to check whether the hash table should be expanded, the
old code was executing a float multiplication and a float comparison
on every hash table access. The new code executes the float
multiplication only when the table size is changed; in the usual
case it only executes an integer comparison, which is much cheaper.
Recode the routines for tabling typeinfos for higher speed. Instead
of storing them in a binary search tree, which requires lots of
comparisons, store the address of the type_ctor_info in a hash table
and chain its argument typeinfos from that.
Add support for expandable tables, which are implemented as arrays
indexed by key - start. This is not used yet, but will be used for
I/O tabling soon.
runtime/mercury_stacks.c:
Conform to the new system of C types for tabling.
Improve the debugging support.
runtime/mercury_wrapper.c:
When debugging tabling, set stdout to be line buffered.
runtime/mercury_engine.h:
runtime/mercury_wrapper.c:
Add a new debugging flag, -dH, for debugging the operation of hash
tables.
In mercury_wrapper.c, sort the code fragments for for processing
the arguments of -d.
runtime/mercury_trace_base.c:
Disable the generation of nuisance debugging messages from Mercury
initialization code called before main, which may have been compiled
with MR_TABLE_DEBUG enabled.
runtime/mercury_conf_param.h:
Document MR_TABLE_STATISTICS as well as MR_TABLE_DEBUG.
trace/mercury_trace_internal.c:
Disable the generation of nuisance debugging messages from Mercury
code called by the debugger that may have been compiled with
MR_TABLE_DEBUG enabled, by turning off MR_tabledebug when MR_trace
is entered. We then turn MR_tabledebug back on (even if it wasn't
turned on in the first place) when executing debugger commands
that require it to be turned on in order to work.
tests/tabling/fib.m:
Improve the (commented out) debugging support. Start the search
for the right problem size closer to its probable end point.
tests/tabling/fib_{float,string,list}.{m,exp}:
New test cases to test the low-level routines for tabling floats,
strings, and user-defined types; they are all modified versions of fib.
tests/tabling/expand.{m,exp}:
tests/tabling/expand_float.{m,exp}:
tests/tabling/expand_poly.{m,exp}:
New test cases to test the code for resizing (i.e. expanding)
hash tables, and the code for handling polymorphic arguments.
tests/tabling/Mmakefile:
Enable the new test cases.
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Fergus Henderson
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88a513b580 |
Reorganize the routines for allocating and deallocating memory:
Estimated hours taken: 8
Reorganize the routines for allocating and deallocating memory:
runtime/mercury_std.h:
runtime/mercury_misc.c:
runtime/mercury_memory.h:
runtime/mercury_memory.c:
- Put the routines in the proper place.
Previously the declarations and definitions of the memory
allocation/deallocation routines were spread amoungst
all four of these files; I moved the ones in mercury_std.h
and mercury_misc.c so that they are now all defined
in mercury_memory.{h,c}
- Avoid unnecessary duplication
The following routines did exactly the same thing,
modulo bugs(!):
allocate_bytes() and newmem()
deallocate_bytes() and oldmem()
make() and allocate_object()
make_many() and allocate_array()
- Use appropriate names.
I added `MR_' prefixes, and ensured that macros that are not
function-like macros use all uppercase. I also used a more
consistent naming scheme.
Previously the names used were
(1) checked_malloc, checked_realloc
(2a) allocate_bytes, deallocate_bytes, reallocate_bytes,
allocate_object, allocate_array, resize_array
(2b) newmem, oldmem, resizemem,
make, make_many, resize_many
The new names are
(1) MR_malloc, MR_free, MR_realloc,
MR_NEW, MR_NEW_ARRAY, MR_RESIZE_ARRAY
(2) MR_GC_malloc, MR_GC_free, MR_GC_realloc,
MR_GC_NEW, MR_GC_NEW_ARRAY, MR_GC_RESIZE_ARRAY
runtime/*.[ch]:
trace/*.[ch]:
library/array.m:
library/benchmarking.m:
library/io.m:
library/std_util.m:
extras/odbc/odbc.m:
extras/aditi/aditi.m:
Use the new names.
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Zoltan Somogyi
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a02bb2c0b5 |
Improve the diagnostics for the tabling stacks.
Estimated hours taken: 0.2 runtime/mercury_stacks.c: Improve the diagnostics for the tabling stacks. |
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Zoltan Somogyi
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a92b478979 |
Fix incorrect debugging message.
Estimated hours taken: 0.1 Fix incorrect debugging message. |
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Fergus Henderson
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62f779e874 |
New file.
Estimated hours taken: 0.25 runtime/mercury_stacks.c: New file. Zoltan forgot to commit this as part of his previous change. |