2 Commits

Author	SHA1	Message	Date
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.	2004-03-12 06:02:19 +00:00
Zoltan Somogyi	dc03496d06	Rewrite significant parts of minimal model tabling so that it works ... Estimated hours taken: 130 Rewrite significant parts of minimal model tabling so that it works in a much wider variety of situations, including coups. Also, clean up the tabling implementation to make it more maintainable, and introduce a new grade component, .mm, that enables minimal model tabling. (Minimal model tabling requires distributed fat, and we don't want to incur such costs unless necessary.) compiler/options.m: Add a new option --use-minimal-model, which for now is documented as "not for general use". This option is a grade option, and is required if minimal model tabling is to work. compiler/handle_options.m: When --use-minimal-model is given, do not allow nondet frame hijacks, since minimal model tabling cannot cope with hijacks. Make --use-minimal-model a grade component. compiler/code_info.m: When --use-minimal-model is given, insert calls to MR_commit_{mark,cut} around goals being committed across. This is now necessary, so that we can detect and handle sitations where a goal being committed across starts but does not complete a tabled goal. compiler/table_gen.m: Rename many of the tabling helper predicates, using a naming scheme that separates predicates used for model_non procedures from those used to implement simpler forms of tabling, while bringing out the parallels between these two sets of predicates. When calls to two tabling helper predicates always occur one after the other, merge the two into one. Generate and use more meaningful variable names; having all of the several variables inserted by this transformation named TableVar was quite confusing. library/private_builtin.m: Reorganize this file, to separate out the different sections. The contents of the non-tabling sections were not modified, only moved around. Rename the predicates referred to by table_gen.m. Move most of the type declarations and complex code out of here, into runtime/mercury_tabling.c. This makes it easier to debug them, since (a) creating a new executable is quicker, since you don't have to wait for lots of mercury compiler invocations, and (b) gdb doesn't get confused by #line directives. It also makes it easier to write them, since you don't have to !&(*U&( remember to double all your double quotes and to backslash all your backslashes. runtime/mercury_grade.h: Include a grade component reflecting whether MR_USE_MINIMAL_MODEL is defined. runtime/mercury_conf_param.h: Document MR_USE_MINIMAL_MODEL. runtime/mercury_stacks.[ch]: The changes to tabling require the addition of two new stacks, the generator stack and the cut stack. This module defines the structures of the frames of these stacks and provides the operations on these stacks. The header file also contains some additional macros that return the addresses of fixed nondet stack slots, not their contents, for use by tabling code. runtime/mercury_context.[ch]: runtime/mercury_memory.[ch]: runtime/mercury_wrapper.[ch]: Declare and set up the two new stacks, both in saved contexts and in the active context, if MR_USE_MINIMAL_MODEL is defined. runtime/mercury_regorder.h: Add four new global virtual machine registers to hold pointers to the memory areas of the two new stacks and the current offsets within them. These are defined whether MR_USE_MINIMAL_MODEL is defined or not, since the cost is minimal and the potential bugs we avoid would be hard to track down. runtime/mercury_engine.h: runtime/mercury_wrapper.c: Add support for a new debugging flag, -dS, which prints the contents of the nondet stack at several points during tabling. runtime/mercury_tabling.[ch]: The implementation of the new tabling system. Much of the new code here is stuff moved from library/private_builtin.m, but in a significantly rewritten form. There is also substantial new code, e.g. to handle the extension of saved stack segments, and to manage dependencies between subgoals in general. Improve the documentation considerably. Replace lists stored as Mercury data structures with lists stored as linked structures in the usual C fashion. This allows us to use debuggers such as ddd on these data structures, whose complexity requires this. Ensure that global names start with MR_. runtime/mercury_init.h: Explicitly include mercury_regs.h at the start. Without this, we get an error, because now mercury_wrappers.h, which mercury_init.h includes, also includes mercury_regs.h, but not before functions have been declared. runtime/Mmakefile: Refer to the new file mercury_stacks.c (mercury_stacks.h already existed, but the module consisted entirely of macros.) Fix a sorting error. scripts/{init,parse,final}_grade_options.sh-subr: scripts/mgnuc.in: Handle the new grade component. tests/tabling/* Add several new test cases that we now pass, most of which we couldn't pass before. Also add some new test cases that we don't pass yet, due to interactions between tabling and negated contexts. trace/mercury_trace_internal.c: If MR_USE_MINIMAL_MODEL is defined, add a new command to print the generator stack. (The new command is deliberately not documented in doc/mdb_doc yet, since (a) it is intended for developers only, and (b) there is no way to test MR_USE_MINIMAL_MODEL in mdb_doc.)	1999-04-20 11:48:56 +00:00