Re: [PATCH v10 1/2] Add condition coverage (MC/DC)

[Jan Hubicka <hubicka@ucw.cz>]

> gcc/ChangeLog:
> 
> 	* builtins.cc (expand_builtin_fork_or_exec): Check
> 	  condition_coverage_flag.
> 	* collect2.cc (main): Add -fno-condition-coverage to OBSTACK.
> 	* common.opt: Add new options -fcondition-coverage and
> 	  -Wcoverage-too-many-conditions.
> 	* doc/gcov.texi: Add --conditions documentation.
> 	* doc/invoke.texi: Add -fcondition-coverage documentation.
> 	* function.cc (free_after_compilation): Free cond_uids.
> 	* function.h (struct function): Add cond_uids.
> 	* gcc.cc: Link gcov on -fcondition-coverage.
> 	* gcov-counter.def (GCOV_COUNTER_CONDS): New.
> 	* gcov-dump.cc (tag_conditions): New.
> 	* gcov-io.h (GCOV_TAG_CONDS): New.
> 	(GCOV_TAG_CONDS_LENGTH): New.
> 	(GCOV_TAG_CONDS_NUM): New.
> 	* gcov.cc (class condition_info): New.
> 	(condition_info::condition_info): New.
> 	(condition_info::popcount): New.
> 	(struct coverage_info): New.
> 	(add_condition_counts): New.
> 	(output_conditions): New.
> 	(print_usage): Add -g, --conditions.
> 	(process_args): Likewise.
> 	(output_intermediate_json_line): Output conditions.
> 	(read_graph_file): Read condition counters.
> 	(read_count_file): Likewise.
> 	(file_summary): Print conditions.
> 	(accumulate_line_info): Accumulate conditions.
> 	(output_line_details): Print conditions.
> 	* gimplify.cc (next_cond_uid): New.
> 	(reset_cond_uid): New.
> 	(shortcut_cond_r): Set condition discriminator.
> 	(tag_shortcut_cond): New.
> 	(gimple_associate_condition_with_expr): New.
> 	(shortcut_cond_expr): Set condition discriminator.
> 	(gimplify_cond_expr): Likewise.
> 	(gimplify_function_tree): Call reset_cond_uid.
> 	* ipa-inline.cc (can_early_inline_edge_p): Check
> 	  condition_coverage_flag.
> 	* ipa-split.cc (pass_split_functions::gate): Likewise.
> 	* passes.cc (finish_optimization_passes): Likewise.
> 	* profile.cc (struct condcov): New declaration.
> 	(cov_length): Likewise.
> 	(cov_blocks): Likewise.
> 	(cov_masks): Likewise.
> 	(cov_maps): Likewise.
> 	(cov_free): Likewise.
> 	(instrument_decisions): New.
> 	(read_thunk_profile): Control output to file.
> 	(branch_prob): Call find_conditions, instrument_decisions.
> 	(init_branch_prob): Add total_num_conds.
> 	(end_branch_prob): Likewise.
> 	* tree-core.h (struct tree_exp): Add condition_uid.
> 	* tree-profile.cc (struct conds_ctx): New.
> 	(CONDITIONS_MAX_TERMS): New.
> 	(EDGE_CONDITION): New.
> 	(topological_cmp): New.
> 	(index_of): New.
> 	(single_p): New.
> 	(single_edge): New.
> 	(contract_edge_up): New.
> 	(struct outcomes): New.
> 	(conditional_succs): New.
> 	(condition_index): New.
> 	(condition_uid): New.
> 	(masking_vectors): New.
> 	(emit_assign): New.
> 	(emit_bitwise_op): New.
> 	(make_top_index_visit): New.
> 	(make_top_index): New.
> 	(paths_between): New.
> 	(struct condcov): New.
> 	(cov_length): New.
> 	(cov_blocks): New.
> 	(cov_masks): New.
> 	(cov_maps): New.
> 	(cov_free): New.
> 	(find_conditions): New.
> 	(struct counters): New.
> 	(find_counters): New.
> 	(resolve_counter): New.
> 	(resolve_counters): New.
> 	(instrument_decisions): New.
> 	(tree_profiling): Check condition_coverage_flag.
> 	(pass_ipa_tree_profile::gate): Likewise.
> 	* tree.h (SET_EXPR_UID): New.
> 	(EXPR_COND_UID): New.
> 
> libgcc/ChangeLog:
> 
> 	* libgcov-merge.c (__gcov_merge_ior): New.
> 
> gcc/testsuite/ChangeLog:
> 
> 	* lib/gcov.exp: Add condition coverage test function.
> 	* g++.dg/gcov/gcov-18.C: New test.
> 	* gcc.misc-tests/gcov-19.c: New test.
> 	* gcc.misc-tests/gcov-20.c: New test.
> 	* gcc.misc-tests/gcov-21.c: New test.
> 	* gcc.misc-tests/gcov-22.c: New test.
> 	* gcc.misc-tests/gcov-23.c: New test.
> ---
>  gcc/builtins.cc                        |    2 +-
>  gcc/collect2.cc                        |    7 +-
>  gcc/common.opt                         |    9 +
>  gcc/doc/gcov.texi                      |   38 +
>  gcc/doc/invoke.texi                    |   21 +
>  gcc/function.cc                        |    1 +
>  gcc/function.h                         |    4 +
>  gcc/gcc.cc                             |    4 +-
>  gcc/gcov-counter.def                   |    3 +
>  gcc/gcov-dump.cc                       |   24 +
>  gcc/gcov-io.h                          |    3 +
>  gcc/gcov.cc                            |  209 ++-
>  gcc/gimplify.cc                        |  123 +-
>  gcc/ipa-inline.cc                      |    2 +-
>  gcc/ipa-split.cc                       |    2 +-
>  gcc/passes.cc                          |    3 +-
>  gcc/profile.cc                         |   76 +-
>  gcc/testsuite/g++.dg/gcov/gcov-18.C    |  282 ++++
>  gcc/testsuite/gcc.misc-tests/gcov-19.c | 1737 ++++++++++++++++++++++++
>  gcc/testsuite/gcc.misc-tests/gcov-20.c |   22 +
>  gcc/testsuite/gcc.misc-tests/gcov-21.c |   16 +
>  gcc/testsuite/gcc.misc-tests/gcov-22.c |  103 ++
>  gcc/testsuite/gcc.misc-tests/gcov-23.c |  361 +++++
>  gcc/testsuite/lib/gcov.exp             |  259 +++-
>  gcc/tree-core.h                        |    3 +
>  gcc/tree-profile.cc                    | 1058 ++++++++++++++-
>  gcc/tree.h                             |    4 +
>  libgcc/libgcov-merge.c                 |    5 +
>  28 files changed, 4339 insertions(+), 42 deletions(-)
>  create mode 100644 gcc/testsuite/g++.dg/gcov/gcov-18.C
>  create mode 100644 gcc/testsuite/gcc.misc-tests/gcov-19.c
>  create mode 100644 gcc/testsuite/gcc.misc-tests/gcov-20.c
>  create mode 100644 gcc/testsuite/gcc.misc-tests/gcov-21.c
>  create mode 100644 gcc/testsuite/gcc.misc-tests/gcov-22.c
>  create mode 100644 gcc/testsuite/gcc.misc-tests/gcov-23.c
> 
> ---
> Changes since v9:
> 
> * function->cond_uid is no longer in ggc memory
> * function->cond_uid and condition annotation is only done when coverage
>   is requested
> * A few new test cases, notably interactions with C++ constexpr
> * Updated comments based on review feedback
> ---
> 

> diff --git a/gcc/ipa-inline.cc b/gcc/ipa-inline.cc
> index dc120e6da5a..9502a21c741 100644
> --- a/gcc/ipa-inline.cc
> +++ b/gcc/ipa-inline.cc
> @@ -682,7 +682,7 @@ can_early_inline_edge_p (struct cgraph_edge *e)
>      }
>    gcc_assert (gimple_in_ssa_p (DECL_STRUCT_FUNCTION (e->caller->decl))
>  	      && gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee->decl)));
> -  if (profile_arc_flag
> +  if ((profile_arc_flag || condition_coverage_flag)
>        && ((lookup_attribute ("no_profile_instrument_function",
>  			    DECL_ATTRIBUTES (caller->decl)) == NULL_TREE)
>  	  != (lookup_attribute ("no_profile_instrument_function",

tree-inline should also copy the cond tags, since always_inline
functions are inlined even at -O0.  But I think this can be done
incrementally.

Patch is OK.
Thanks a lot and sorry for taking so long on this one.
Honza