Is it necessary to declare zero_counts array at all? Can a flag field
be added to dyn_cgraph_node structure to indicate if it is fixed up?
David
On Fri, Sep 12, 2014 at 4:31 PM, Teresa Johnson <tejohn...@google.com> wrote:
> This patch addresses issues when running gcov-tool after performing
> COMDAT fixup during dyn-ipa. Functions that were previously all zero
> counts are marked, and the counts are discarded when being read in
> by gcov-tool before recalculating module groups and summary info.
>
> While here, cleaned up the gcov-tool output (remove an overly-verbose output,
> make all output consistently go to stderr).
>
> Passes regression tests and manual tests. Ok for google branches?
>
> 2014-09-12 Teresa Johnson <tejohn...@google.com>
>
> * gcc/coverage.c (read_counts_file): Handle new section.
> * gcc/gcov.c (read_count_file): Ditto.
> * gcc/gcov-dump.c (dump_gcov_file): Ditto.
> (tag_function): Ditto.
> (tag_zero_fixup): New function.
> * gcc/gcov-io.c (gcov_read_comdat_zero_fixup): Ditto.
> * gcc/gcov-io.h (gcov_read_comdat_zero_fixup): Ditto.
> * libgcc/dyn-ipa.c (struct checksum_alias): Change flag to pointer.
> (new_checksum_alias): Ditto.
> (cfg_checksum_insert): Ditto.
> (checksum_set_insert): Ditto.
> (gcov_build_callgraph): New parameter.
> (gcov_collect_imported_modules): Add assert for duplicate gcda reads.
> (gcov_fixup_counters_checksum): Change flag to pointer to flag, set
> it.
> (__gcov_compute_module_groups): New parameter.
> * libgcc/libgcov-driver.c (set_gcov_fn_fixed_up): New function.
> (get_gcov_fn_fixed_up): Ditto.
> (gcov_exit_merge_gcda): Handle new section.
> (gcov_write_comdat_zero_fixup): Ditto.
> (gcov_write_build_info): Ditto.
> (gcov_write_comdat_zero_fixup): New function.
> (gcov_write_func_counters): Fix indent.
> (gcov_dump_module_info): Write new flag section.
> * libgcc/libgcov.h (gcov_get_counter): Clear fixed-up counters.
> (gcov_get_counter_target): Ditto.
> * libgcc/libgcov-util.c (tag_function): Annotate fixed-up functions,
> remove overly verbose output.
> (tag_counters): Clear fixed-up counters.
> (lipo_process_substitute_string_1): Send all verbose output to stderr.
> (tag_zero_fixup): New function.
> (read_gcda_file): Deallocate flag array.
> (gcov_profile_scale): Send all verbose output to stderr.
> (gcov_profile_normalize): Ditto.
>
> Index: gcc/coverage.c
> ===================================================================
> --- gcc/coverage.c (revision 215230)
> +++ gcc/coverage.c (working copy)
> @@ -820,6 +820,14 @@ read_counts_file (const char *da_file_name, unsign
> free (build_info_strings[i]);
> free (build_info_strings);
> }
> + else if (tag == GCOV_TAG_COMDAT_ZERO_FIXUP)
> + {
> + /* Zero-profile fixup flags are not used by the compiler, read and
> + ignore. */
> + gcov_unsigned_t num_fn;
> + int *zero_fixup_flags = gcov_read_comdat_zero_fixup
> (length, &num_fn);
> + free (zero_fixup_flags);
> + }
> else if (GCOV_TAG_IS_COUNTER (tag) && fn_ident)
> {
> counts_entry_t **slot, *entry, elt;
> Index: gcc/gcov.c
> ===================================================================
> --- gcc/gcov.c (revision 215230)
> +++ gcc/gcov.c (working copy)
> @@ -1441,6 +1441,12 @@ read_count_file (function_t *fns)
> free (build_info_strings[i]);
> free (build_info_strings);
> }
> + else if (tag == GCOV_TAG_COMDAT_ZERO_FIXUP)
> + {
> + gcov_unsigned_t num_fn;
> + int *zero_fixup_flags = gcov_read_comdat_zero_fixup
> (length, &num_fn);
> + free (zero_fixup_flags);
> + }
> else if (tag == GCOV_TAG_FUNCTION && !length)
> ; /* placeholder */
> else if (tag == GCOV_TAG_FUNCTION && length ==
> GCOV_TAG_FUNCTION_LENGTH)
> Index: gcc/gcov-dump.c
> ===================================================================
> --- gcc/gcov-dump.c (revision 215230)
> +++ gcc/gcov-dump.c (working copy)
> @@ -42,6 +42,7 @@ static void tag_summary (const char *, unsigned, u
> static void tag_module_info (const char *, unsigned, unsigned);
> static void dump_working_sets (const char *filename ATTRIBUTE_UNUSED,
> const struct gcov_ctr_summary *summary);
> +static void tag_zero_fixup (const char *, unsigned, unsigned);
> static void tag_build_info (const char *, unsigned, unsigned);
> extern int main (int, char **);
>
> @@ -57,6 +58,9 @@ static int flag_dump_positions = 0;
> static int flag_dump_aux_modules_only = 0;
> static int flag_dump_working_sets = 0;
>
> +static unsigned num_fn_info;
> +static int *zero_fixup_flags = NULL;
> +
> static const struct option options[] =
> {
> { "help", no_argument, NULL, 'h' },
> @@ -79,6 +83,7 @@ static const tag_format_t tag_table[] =
> {GCOV_TAG_OBJECT_SUMMARY, "OBJECT_SUMMARY", tag_summary},
> {GCOV_TAG_PROGRAM_SUMMARY, "PROGRAM_SUMMARY", tag_summary},
> {GCOV_TAG_MODULE_INFO, "MODULE INFO", tag_module_info},
> + {GCOV_TAG_COMDAT_ZERO_FIXUP, "ZERO FIXUP", tag_zero_fixup},
> {GCOV_TAG_BUILD_INFO, "BUILD INFO", tag_build_info},
> {0, NULL, NULL}
> };
> @@ -274,6 +279,8 @@ dump_gcov_file (const char *filename)
> printf ("%s:stamp %lu\n", filename, (unsigned long)stamp);
> }
>
> + num_fn_info = 0;
> +
> while (1)
> {
> gcov_position_t base, position = gcov_position ();
> @@ -341,6 +348,7 @@ dump_gcov_file (const char *filename)
> break;
> }
> }
> + free (zero_fixup_flags);
> gcov_close ();
> }
>
> @@ -354,7 +362,9 @@ tag_function (const char *filename ATTRIBUTE_UNUSE
> printf (" placeholder");
> else
> {
> - printf (" ident=%u", gcov_read_unsigned ());
> + int had_fixup = zero_fixup_flags && zero_fixup_flags[num_fn_info];
> + printf (" ident=%u%s", gcov_read_unsigned (),
> + had_fixup ? " (Was 0-count COMDAT)" : "");
> printf (", lineno_checksum=0x%08x", gcov_read_unsigned ());
> printf (", cfg_checksum=0x%08x", gcov_read_unsigned ());
>
> @@ -369,6 +379,7 @@ tag_function (const char *filename ATTRIBUTE_UNUSE
> printf (":%u", gcov_read_unsigned ());
> }
> }
> + num_fn_info++;
> }
>
> static void
> @@ -600,6 +611,32 @@ tag_module_info (const char *filename ATTRIBUTE_UN
> }
>
> static void
> +tag_zero_fixup (const char *filename,
> + unsigned tag ATTRIBUTE_UNUSED, unsigned length)
> +{
> + gcov_unsigned_t num_fns = 0;
> + zero_fixup_flags = gcov_read_comdat_zero_fixup (length, &num_fns);
> + if (!zero_fixup_flags)
> + {
> + printf ("%s:error reading zero fixup flags\n", filename);
> + return;
> + }
> + printf (" num_fns=%u", num_fns);
> + for (unsigned i = 0; i < num_fns; i++)
> + {
> + if (!(i % 32))
> + {
> + printf ("\n");
> + print_prefix (filename, 0, 0);
> + printf ("\t\t");
> + }
> + if (!(i % 8))
> + printf ("%s%4u:", (i%32)?" ":"", i);
> + printf ("%u", zero_fixup_flags[i]);
> + }
> +}
> +
> +static void
> tag_build_info (const char *filename,
> unsigned tag ATTRIBUTE_UNUSED, unsigned length)
> {
> Index: gcc/gcov-io.c
> ===================================================================
> --- gcc/gcov-io.c (revision 215230)
> +++ gcc/gcov-io.c (working copy)
> @@ -691,6 +691,36 @@ gcov_read_summary (struct gcov_summary *summary)
> }
> }
>
> +/* Read LENGTH words (unsigned type) from a zero profile fixup record with
> the
> + number of function flags saved in NUM_FNS. Returns the int flag
> array, which
> + should be deallocated by caller, or NULL on error. */
> +
> +GCOV_LINKAGE int *
> +gcov_read_comdat_zero_fixup (gcov_unsigned_t length,
> + gcov_unsigned_t *num_fns)
> +{
> + unsigned ix, f_ix;
> + gcov_unsigned_t num = gcov_read_unsigned ();
> + /* The length consists of 1 word to hold the number of functions,
> + plus enough 32-bit words to hold 1 bit/function. */
> + gcc_assert ((num + 31) / 32 + 1 == length);
> + int *zero_fixup_flags = (int *) xcalloc (num, sizeof (int));
> + for (ix = 0; ix < length - 1; ix++)
> + {
> + gcov_unsigned_t bitvector = gcov_read_unsigned ();
> + f_ix = ix * 32;
> + while (bitvector)
> + {
> + if (bitvector & 0x1)
> + zero_fixup_flags[f_ix] = 1;
> + f_ix++;
> + bitvector >>= 1;
> + }
> + }
> + *num_fns = num;
> + return zero_fixup_flags;
> +}
> +
> /* Read NUM_STRINGS strings (as an unsigned array) in STRING_ARRAY, and
> return
> the number of words read. */
>
> Index: gcc/gcov-io.h
> ===================================================================
> --- gcc/gcov-io.h (revision 215230)
> +++ gcc/gcov-io.h (working copy)
> @@ -129,7 +129,7 @@ see the files COPYING3 and COPYING.RUNTIME respect
> blocks they are for.
>
> The data file contains the following records.
> - data: {unit summary:program* build_info function-data*}*
> + data: {unit summary:program* build_info zero_fixup function-data*}*
> unit: header int32:checksum
> function-data: announce_function present counts
> announce_function: header int32:ident
> @@ -142,6 +142,7 @@ see the files COPYING3 and COPYING.RUNTIME respect
> histogram: {int32:bitvector}8 histogram-buckets*
> histogram-buckets: int32:num int64:min int64:sum
> build_info: string:info*
> + zero_fixup: int32:num int32:bitvector*
>
> The ANNOUNCE_FUNCTION record is the same as that in the note file,
> but without the source location. The COUNTS gives the
> @@ -158,6 +159,12 @@ see the files COPYING3 and COPYING.RUNTIME respect
> build. For example, it can be used to include source revision
> information that is useful in diagnosing profile mis-matches.
>
> + ZERO_FIXUP record contains a count of functions in the gcda file
> + and an array of bitvectors indexed by the function index's in the
> + function-data section. Each bit flags whether the function was a
> + COMDAT that had all-zero profiles that was fixed up by dyn-ipa
> + using profiles from functions with matching checksums in other modules.
> +
> This file is included by both the compiler, gcov tools and the
> runtime support library libgcov. IN_LIBGCOV and IN_GCOV are used to
> distinguish which case is which. If IN_LIBGCOV is nonzero,
> @@ -261,6 +268,9 @@ typedef unsigned HOST_WIDEST_INT gcov_type_unsigne
> #define GCOV_TAG_COUNTER_NUM(LENGTH) ((LENGTH) / 2)
> #define GCOV_TAG_OBJECT_SUMMARY ((gcov_unsigned_t)0xa1000000) /* Obsolete */
> #define GCOV_TAG_PROGRAM_SUMMARY ((gcov_unsigned_t)0xa3000000)
> +#define GCOV_TAG_COMDAT_ZERO_FIXUP ((gcov_unsigned_t)0xa9000000)
> +/* Ceiling divide by 32 bit word size, plus one word to hold NUM. */
> +#define GCOV_TAG_COMDAT_ZERO_FIXUP_LENGTH(NUM) (1 + (NUM + 31) / 32)
> #define GCOV_TAG_SUMMARY_LENGTH(NUM) \
> (1 + GCOV_COUNTERS_SUMMABLE * (10 + 3 * 2) + (NUM) * 5)
> #define GCOV_TAG_BUILD_INFO ((gcov_unsigned_t)0xa7000000)
> @@ -441,6 +451,9 @@ GCOV_LINKAGE int gcov_close (void) ATTRIBUTE_HIDDE
> GCOV_LINKAGE gcov_unsigned_t gcov_read_unsigned (void) ATTRIBUTE_HIDDEN;
> GCOV_LINKAGE gcov_type gcov_read_counter (void) ATTRIBUTE_HIDDEN;
> GCOV_LINKAGE void gcov_read_summary (struct gcov_summary *) ATTRIBUTE_HIDDEN;
> +GCOV_LINKAGE int *gcov_read_comdat_zero_fixup (gcov_unsigned_t,
> + gcov_unsigned_t *)
> + ATTRIBUTE_HIDDEN;
> GCOV_LINKAGE char **gcov_read_build_info (gcov_unsigned_t, gcov_unsigned_t *)
> ATTRIBUTE_HIDDEN;
> GCOV_LINKAGE const char *gcov_read_string (void);
> Index: libgcc/dyn-ipa.c
> ===================================================================
> --- libgcc/dyn-ipa.c (revision 215230)
> +++ libgcc/dyn-ipa.c (working copy)
> @@ -107,8 +107,9 @@ struct checksum_alias
> struct checksum_alias *next_alias;
> gcov_type guid;
> const struct gcov_fn_info *fi_ptr;
> - /* Does this function have all-zero arc counts? */
> - int zero_counts;
> + /* Non-NULL pointer to flag if this function has all-zero arc counts, to be
> + set if we perform fixup. */
> + int *zero_count_fixup;
> };
>
> /* Module info is stored in dyn_caph->sup_modules
> @@ -178,10 +179,10 @@ extern gcov_unsigned_t __gcov_lipo_merge_modu_edge
> extern gcov_unsigned_t __gcov_lipo_weak_inclusion;
>
> #if defined(inhibit_libc)
> -void __gcov_build_callgraph (void) {}
> +void __gcov_build_callgraph (int **zero_counts) {}
> #else
>
> -int __gcov_compute_module_groups (void) ATTRIBUTE_HIDDEN;
> +int __gcov_compute_module_groups (int **zero_counts) ATTRIBUTE_HIDDEN;
> void __gcov_finalize_dyn_callgraph (void) ATTRIBUTE_HIDDEN;
> static void gcov_dump_callgraph (gcov_type);
> static void gcov_dump_cgraph_node_short (struct dyn_cgraph_node *node);
> @@ -378,18 +379,19 @@ lineno_checksum_get_key (const void *p)
> }
>
> /* Create a new checksum_alias struct for function with GUID, FI_PTR,
> - and ZERO_COUNTS flag. Prepends to list NEXT and returns new struct. */
> + and ZERO_COUNT_FIXUP flag pointer. Prepends to list NEXT and returns
> + new struct. */
>
> static struct checksum_alias *
> new_checksum_alias (gcov_type guid, const struct gcov_fn_info *fi_ptr,
> - int zero_counts,
> + int *zero_count_fixup,
> struct checksum_alias *next)
> {
> struct checksum_alias *alias = XNEW (struct checksum_alias);
> alias->next_alias = next;
> alias->fi_ptr = fi_ptr;
> alias->guid = guid;
> - alias->zero_counts = zero_counts;
> + alias->zero_count_fixup = zero_count_fixup;
> return alias;
> }
>
> @@ -407,11 +409,12 @@ find_cfg_checksum (struct checksum_alias_info *lis
> }
>
> /* Insert a new checksum_alias struct into LIST for function with
> - CFG_CHECKSUM and associated GUID, FI_PTR, and ZERO_COUNTS flag. */
> + CFG_CHECKSUM and associated GUID, FI_PTR, and ZERO_COUNT_FIXUP
> + flag pointer. */
>
> static struct checksum_alias_info *
> cfg_checksum_insert (unsigned cfg_checksum, gcov_type guid,
> - const struct gcov_fn_info *fi_ptr, int zero_counts,
> + const struct gcov_fn_info *fi_ptr, int
> *zero_count_fixup,
> struct checksum_alias_info *list)
> {
> struct checksum_alias_info *alias_info;
> @@ -419,7 +422,8 @@ cfg_checksum_insert (unsigned cfg_checksum, gcov_t
> if (alias_info)
> {
> gcc_assert (alias_info->alias_list);
> - alias_info->alias_list = new_checksum_alias (guid, fi_ptr, zero_counts,
> + alias_info->alias_list = new_checksum_alias (guid, fi_ptr,
> + zero_count_fixup,
> alias_info->alias_list);
> return list;
> }
> @@ -428,7 +432,8 @@ cfg_checksum_insert (unsigned cfg_checksum, gcov_t
> alias_info = XNEW (struct checksum_alias_info);
> alias_info->next_cfg_checksum = list;
> alias_info->cfg_checksum = cfg_checksum;
> - alias_info->alias_list = new_checksum_alias (guid, fi_ptr, zero_counts,
> + alias_info->alias_list = new_checksum_alias (guid, fi_ptr,
> + zero_count_fixup,
> NULL);
> return alias_info;
> }
> @@ -436,12 +441,12 @@ cfg_checksum_insert (unsigned cfg_checksum, gcov_t
>
> /* Insert a new checksum_alias struct into lineno_pointer_sets for
> function with
> LINENO_CHECKSUM and CFG_CHECKSUM with associated GUID, FI_PTR, and
> - ZERO_COUNTS flag. */
> + ZERO_COUNT_FIXUP flag pointer. */
>
> static void
> checksum_set_insert (unsigned lineno_checksum, unsigned cfg_checksum,
> gcov_type guid, const struct gcov_fn_info *fi_ptr,
> - int zero_counts)
> + int *zero_count_fixup)
> {
> struct dyn_pointer_set *p = the_dyn_call_graph.lineno_pointer_sets;
> if (!p)
> @@ -452,7 +457,7 @@ checksum_set_insert (unsigned lineno_checksum, uns
> if (*m)
> {
> (*m)->cfg_checksum_list = cfg_checksum_insert (cfg_checksum, guid,
> - fi_ptr, zero_counts,
> + fi_ptr,
> zero_count_fixup,
>
> (*m)->cfg_checksum_list);
> }
> else
> @@ -460,7 +465,8 @@ checksum_set_insert (unsigned lineno_checksum, uns
> *m = XNEW (struct lineno_checksum_alias);
> (*m)->lineno_checksum = lineno_checksum;
> (*m)->cfg_checksum_list = cfg_checksum_insert (cfg_checksum, guid,
> - fi_ptr,
> zero_counts, NULL);
> + fi_ptr,
> zero_count_fixup,
> + NULL);
> p->n_elements++;
> }
> }
> @@ -801,10 +807,10 @@ gcov_build_callgraph_ic_fn (struct dyn_cgraph_node
> }
> }
>
> -/* Build the dynamic call graph. */
> +/* Build the dynamic call graph and update ZERO_COUNTS flags. */
>
> static void
> -gcov_build_callgraph (void)
> +gcov_build_callgraph (int **zero_counts)
> {
> struct gcov_info *gi_ptr;
> unsigned m_ix;
> @@ -852,9 +858,19 @@ static void
> if (total_arc_count != 0)
> the_dyn_call_graph.num_nodes_executed++;
> if (fixup_type)
> - checksum_set_insert (fi_ptr->lineno_checksum,
> - fi_ptr->cfg_checksum, caller->guid,
> - fi_ptr, total_arc_count == 0);
> + {
> + int *zero_count_fixup = NULL;
> + /* Passing in a non-NULL zero_count_fixup pointer
> + indicates that the counts were all zero for this
> + function, and the fixup routine will set the flag
> + if the function's counters are updated to non-zero
> + values. */
> + if (total_arc_count == 0)
> + zero_count_fixup = &zero_counts[m_ix][f_ix];
> + checksum_set_insert (fi_ptr->lineno_checksum,
> + fi_ptr->cfg_checksum,
> caller->guid,
> + fi_ptr, zero_count_fixup);
> + }
> }
> ci_ptr++;
> }
> @@ -1251,7 +1267,14 @@ gcov_collect_imported_modules (const void *value,
> out_array = (struct gcov_import_mod_array *) data1;
>
> if (m->imp_mod != out_array->importing_module)
> + {
> out_array->imported_modules[out_array->len++] = m;
> + /* Sanity check that the importing (primary) module is not
> + actually the same as the new aux module. This could happen if
> + we accidentally read in the same gcda file twice. */
> + gcc_assert (m->imp_mod->mod_info->ident !=
> + out_array->importing_module->mod_info->ident);
> + }
>
> return 1;
> }
> @@ -2957,7 +2980,7 @@ gcov_fixup_counters_checksum (const struct checksu
> for (alias = info->alias_list; alias;
> alias = alias->next_alias)
> {
> - if (alias->zero_counts)
> + if (alias->zero_count_fixup)
> {
> found = 1;
> break;
> @@ -2972,7 +2995,7 @@ gcov_fixup_counters_checksum (const struct checksu
> for (alias = info->alias_list; alias;
> alias = alias->next_alias)
> {
> - if (alias->zero_counts)
> + if (alias->zero_count_fixup)
> continue;
> merge_ctrs (merged_ctrs, alias->fi_ptr->ctrs, alias->guid);
> found = 1;
> @@ -2990,9 +3013,10 @@ gcov_fixup_counters_checksum (const struct checksu
> for (alias = info->alias_list; alias;
> alias = alias->next_alias)
> {
> - if (!alias->zero_counts)
> + if (!alias->zero_count_fixup)
> continue;
> copy_ctrs (alias->fi_ptr->ctrs, alias->guid, merged_ctrs);
> + *alias->zero_count_fixup = 1;
> }
>
> return 1;
> @@ -3040,11 +3064,13 @@ gcov_fixup_zero_counters (void)
> return changed;
> }
>
> -/* Compute module groups needed for L-IPO compilation. Returns 1 if any
> - counter fixups were applied, requiring a profile rewrite, 0 otherwise. */
> +/* Compute module groups needed for L-IPO compilation. The ZERO_COUNTS
> + flags are set for functions with zero count fixups applied. Returns 1
> + if any counter fixups were applied, requiring a profile rewrite,
> + 0 otherwise. */
>
> int
> -__gcov_compute_module_groups (void)
> +__gcov_compute_module_groups (int **zero_counts)
> {
> gcov_type cut_off_count;
> char *seed = getenv ("LIPO_RANDOM_GROUPING");
> @@ -3091,7 +3117,7 @@ int
> fixup_type = atoi (do_fixup);
>
> /* First compute dynamic call graph. */
> - gcov_build_callgraph ();
> + gcov_build_callgraph (zero_counts);
>
> cut_off_count = gcov_compute_cutoff_count ();
>
> Index: libgcc/libgcov-driver.c
> ===================================================================
> --- libgcc/libgcov-driver.c (revision 215230)
> +++ libgcc/libgcov-driver.c (working copy)
> @@ -55,7 +55,7 @@ static gcov_unsigned_t gcov_cur_module_id = 0;
>
>
> /* Dynamic call graph build and form module groups. */
> -int __gcov_compute_module_groups (void) ATTRIBUTE_HIDDEN;
> +int __gcov_compute_module_groups (int **zero_counts) ATTRIBUTE_HIDDEN;
> void __gcov_finalize_dyn_callgraph (void) ATTRIBUTE_HIDDEN;
>
> /* The following functions can be called from outside of this file. */
> @@ -129,6 +129,24 @@ set_gcov_list (struct gcov_info *head)
> __gcov_list = head;
> }
>
> +/* Flag if the current function being read was marked as having fixed-up
> + zero counters. */
> +static int __gcov_curr_fn_fixed_up;
> +
> +/* Set function fixed up flag. */
> +void
> +set_gcov_fn_fixed_up (int fixed_up)
> +{
> + __gcov_curr_fn_fixed_up = fixed_up;
> +}
> +
> +/* Return function fixed up flag. */
> +int
> +get_gcov_fn_fixed_up (void)
> +{
> + return __gcov_curr_fn_fixed_up;
> +}
> +
> /* Size of the longest file name. */
> /* We need to expose this static variable when compiling for gcov-tool. */
> #ifndef IN_GCOV_TOOL
> @@ -564,6 +582,7 @@ gcov_exit_merge_gcda (struct gcov_info *gi_ptr,
> int error = 0;
> struct gcov_fn_buffer **fn_tail = &fn_buffer;
> struct gcov_summary_buffer **sum_tail = &sum_buffer;
> + int *zero_fixup_flags = NULL;
>
> length = gcov_read_unsigned ();
> if (!gcov_version (gi_ptr, length, gi_filename))
> @@ -625,6 +644,21 @@ gcov_exit_merge_gcda (struct gcov_info *gi_ptr,
> tag = gcov_read_unsigned ();
> }
>
> + if (tag == GCOV_TAG_COMDAT_ZERO_FIXUP)
> + {
> + length = gcov_read_unsigned ();
> + gcov_unsigned_t num_fns = 0;
> + zero_fixup_flags = gcov_read_comdat_zero_fixup (length, &num_fns);
> + if (!zero_fixup_flags)
> + {
> + gcov_error ("profiling:%s:Error reading zero fixup flags\n",
> + gi_filename);
> + return -1;
> + }
> +
> + tag = gcov_read_unsigned ();
> + }
> +
> /* Merge execution counts for each function. */
> for (f_ix = 0; (unsigned)f_ix != gi_ptr->n_functions;
> f_ix++, tag = gcov_read_unsigned ())
> @@ -658,6 +692,9 @@ gcov_exit_merge_gcda (struct gcov_info *gi_ptr,
> continue;
> }
>
> + if (zero_fixup_flags)
> + set_gcov_fn_fixed_up (zero_fixup_flags[f_ix]);
> +
> length = gcov_read_unsigned ();
> if (length != gfi_ptr->ident)
> goto read_mismatch;
> @@ -689,6 +726,7 @@ gcov_exit_merge_gcda (struct gcov_info *gi_ptr,
> if ((error = gcov_is_error ()))
> goto read_error;
> }
> + free (zero_fixup_flags);
>
> if (tag && tag != GCOV_TAG_MODULE_INFO)
> {
> @@ -706,6 +744,34 @@ read_error:
> return -1;
> }
>
> +
> +/* Write NUM_FNS ZERO_COUNTS fixup flags to a gcda file starting from its
> + current location. */
> +
> +static void
> +gcov_write_comdat_zero_fixup (int *zero_counts, unsigned num_fns)
> +{
> + unsigned f_ix;
> + gcov_unsigned_t len = GCOV_TAG_COMDAT_ZERO_FIXUP_LENGTH (num_fns);
> + gcov_write_tag_length (GCOV_TAG_COMDAT_ZERO_FIXUP, len);
> +
> + gcov_write_unsigned (num_fns);
> + gcov_unsigned_t bitvector = 0, b_ix = 0;
> + for (f_ix = 0; f_ix != num_fns; f_ix++)
> + {
> + if (zero_counts[f_ix])
> + bitvector |= 1 << b_ix;
> + if (++b_ix == 32)
> + {
> + gcov_write_unsigned (bitvector);
> + b_ix = 0;
> + bitvector = 0;
> + }
> + }
> + if (b_ix > 0)
> + gcov_write_unsigned (bitvector);
> +}
> +
> /* Write build_info strings from GI_PTR to a gcda file starting from
> its current
> location. */
>
> @@ -758,7 +824,7 @@ gcov_write_func_counters (struct gcov_info *gi_ptr
> if (gfi_ptr && gfi_ptr->key == gi_ptr)
> length = GCOV_TAG_FUNCTION_LENGTH;
> else
> - length = 0;
> + length = 0;
> }
>
> gcov_write_tag_length (GCOV_TAG_FUNCTION, length);
> @@ -1104,9 +1170,24 @@ gcov_dump_module_info (struct gcov_filename_aux *g
> {
> struct gcov_info *gi_ptr;
>
> + unsigned max_module_id = 0;
> + for (gi_ptr = __gcov_list; gi_ptr; gi_ptr = gi_ptr->next)
> + {
> + unsigned mod_id = gi_ptr->mod_info->ident;
> + if (max_module_id < mod_id)
> + max_module_id = mod_id;
> + }
> + int **zero_counts = (int **) xcalloc (max_module_id, sizeof (int *));
> + for (gi_ptr = __gcov_list; gi_ptr; gi_ptr = gi_ptr->next)
> + {
> + unsigned mod_id = gi_ptr->mod_info->ident;
> + zero_counts[mod_id-1] = (int *) xcalloc (gi_ptr->n_functions,
> + sizeof (int));
> + }
> +
> /* Compute the module groups and record whether there were any
> counter fixups applied that require rewriting the counters. */
> - int changed = __gcov_compute_module_groups ();
> + int changed = __gcov_compute_module_groups (zero_counts);
>
> /* Now write out module group info. */
> for (gi_ptr = __gcov_list; gi_ptr; gi_ptr = gi_ptr->next)
> @@ -1129,8 +1210,15 @@ gcov_dump_module_info (struct gcov_filename_aux *g
> gcov_position_t eof_pos = gi_ptr->eof_pos;
> gcov_rewrite ();
> gcov_seek (summary_end_pos);
> +
> + unsigned mod_id = gi_ptr->mod_info->ident;
> + gcov_write_comdat_zero_fixup (zero_counts[mod_id-1],
> + gi_ptr->n_functions);
> + gcov_position_t zero_fixup_eof_pos = gcov_position ();
> +
> gcov_write_func_counters (gi_ptr);
> - gcc_assert (eof_pos == gi_ptr->eof_pos);
> + gcc_assert (eof_pos + (zero_fixup_eof_pos - summary_end_pos)
> + == gi_ptr->eof_pos);
> }
> }
> else
> @@ -1149,7 +1237,11 @@ gcov_dump_module_info (struct gcov_filename_aux *g
> "profiling:%s:Error writing\n",
> gi_filename);
> gcov_write_import_file (gi_filename, gi_ptr);
> + free (zero_counts[gi_ptr->mod_info->ident-1]);
> }
> +
> + free (zero_counts);
> +
> __gcov_finalize_dyn_callgraph ();
> }
>
> Index: libgcc/libgcov.h
> ===================================================================
> --- libgcc/libgcov.h (revision 215230)
> +++ libgcc/libgcov.h (working copy)
> @@ -349,6 +349,9 @@ gcov_get_sorted_import_module_array (struct gcov_i
> ATTRIBUTE_HIDDEN;
> GCOV_LINKAGE inline void gcov_rewrite (void);
>
> +extern void set_gcov_fn_fixed_up (int fixed_up);
> +extern int get_gcov_fn_fixed_up (void);
> +
> /* "Counts" stored in gcda files can be a real counter value, or
> an target address. When differentiate these two types because
> when manipulating counts, we should only change real counter values,
> @@ -361,7 +364,13 @@ gcov_get_counter (void)
> /* This version is for reading count values in libgcov runtime:
> we read from gcda files. */
>
> - return gcov_read_counter ();
> + if (get_gcov_fn_fixed_up ())
> + {
> + gcov_read_counter ();
> + return 0;
> + }
> + else
> + return gcov_read_counter ();
> #else
> /* This version is for gcov-tool. We read the value from memory and
> multiply it by the merge weight. */
> @@ -380,7 +389,13 @@ gcov_get_counter_target (void)
> /* This version is for reading count target values in libgcov runtime:
> we read from gcda files. */
>
> - return gcov_read_counter ();
> + if (get_gcov_fn_fixed_up ())
> + {
> + gcov_read_counter ();
> + return 0;
> + }
> + else
> + return gcov_read_counter ();
> #else
> /* This version is for gcov-tool. We read the value from memory
> and we do NOT
> multiply it by the merge weight. */
> Index: libgcc/libgcov-util.c
> ===================================================================
> --- libgcc/libgcov-util.c (revision 215230)
> +++ libgcc/libgcov-util.c (working copy)
> @@ -66,6 +66,7 @@ static void tag_lines (unsigned, unsigned);
> static void tag_counters (unsigned, unsigned);
> static void tag_summary (unsigned, unsigned);
> static void tag_module_info (unsigned, unsigned);
> +static void tag_zero_fixup (unsigned, unsigned);
>
> /* The gcov_info for the first module. */
> static struct gcov_info *curr_gcov_info;
> @@ -88,6 +89,8 @@ static int k_ctrs_types;
> /* The longest length of all the filenames. */
> static int max_filename_len;
>
> +static int *zero_fixup_flags = NULL;
> +
> /* Merge functions for counters. Similar to __gcov_dyn_ipa_merge_*
> functions in dyn-ipa.c, which were derived from these, except
> the versions in dyn-ipa are used when merging from another array. */
> @@ -143,6 +146,7 @@ static const tag_format_t tag_table[] =
> {GCOV_TAG_OBJECT_SUMMARY, "OBJECT_SUMMARY", tag_summary},
> {GCOV_TAG_PROGRAM_SUMMARY, "PROGRAM_SUMMARY", tag_summary},
> {GCOV_TAG_MODULE_INFO, "MODULE INFO", tag_module_info},
> + {GCOV_TAG_COMDAT_ZERO_FIXUP, "ZERO FIXUP", tag_zero_fixup},
> {0, NULL, NULL}
> };
>
> @@ -169,14 +173,18 @@ tag_function (unsigned tag ATTRIBUTE_UNUSED, unsig
> k_ctrs[i].num = 0;
> k_ctrs_types = 0;
>
> + if (zero_fixup_flags)
> + {
> + set_gcov_fn_fixed_up (zero_fixup_flags[num_fn_info]);
> + if (get_gcov_fn_fixed_up () && verbose)
> + fprintf (stderr, "Function id=%d fixed up\n", curr_fn_info->ident);
> + }
> +
> curr_fn_info->key = curr_gcov_info;
> curr_fn_info->ident = gcov_read_unsigned ();
> curr_fn_info->lineno_checksum = gcov_read_unsigned ();
> curr_fn_info->cfg_checksum = gcov_read_unsigned ();
> num_fn_info++;
> -
> - if (verbose)
> - fnotice (stdout, "tag one function id=%d\n", curr_fn_info->ident);
> }
>
> /* Handler for reading block tag. */
> @@ -226,7 +234,13 @@ tag_counters (unsigned tag, unsigned length)
> gcc_assert (values);
>
> for (ix = 0; ix != n_counts; ix++)
> - values[ix] = gcov_read_counter ();
> + {
> + gcov_type val = gcov_read_counter ();
> + if (!get_gcov_fn_fixed_up ())
> + values[ix] = val;
> + else
> + values[ix] = 0;
> + }
> }
>
> /* Handler for reading summary tag. */
> @@ -323,7 +337,7 @@ lipo_process_substitute_string_1 (char *input_str,
> char *t;
>
> if (verbose)
> - printf ("Substitute: %s \n", input_str);
> + fprintf (stderr, "Substitute: %s \n", input_str);
> t = (char*) xmalloc (strlen (input_str) + 1
> + strlen (new_str) - strlen (cur_str));
> *p = 0;
> @@ -332,7 +346,7 @@ lipo_process_substitute_string_1 (char *input_str,
> strcat (t, new_str);
> strcat (t, p + strlen (cur_str));
> if (verbose)
> - printf (" --> %s\n", t);
> + fprintf (stderr, " --> %s\n", t);
> return t;
> }
>
> @@ -397,6 +411,16 @@ tag_module_info (unsigned tag ATTRIBUTE_UNUSED, un
> free (mod_info);
> }
>
> +/* Handler for reading the COMDAT zero-profile fixup section. */
> +
> +static void
> +tag_zero_fixup (unsigned tag ATTRIBUTE_UNUSED, unsigned length)
> +{
> + gcov_unsigned_t num_fns = 0;
> + zero_fixup_flags = gcov_read_comdat_zero_fixup (length, &num_fns);
> + gcc_assert (zero_fixup_flags);
> +}
> +
> /* Read the content of a gcda file FILENAME, and return a gcov_info
> data structure.
> Program level summary CURRENT_SUMMARY will also be updated. */
>
> @@ -520,6 +544,7 @@ read_gcda_file (const char *filename)
> }
>
> read_gcda_finalize (obj_info);
> + free (zero_fixup_flags);
> gcov_close ();
>
> return obj_info;
> @@ -1099,7 +1124,7 @@ gcov_profile_scale (struct gcov_info *profile, flo
> unsigned f_ix;
>
> if (verbose)
> - fnotice (stdout, "scale_factor is %f or %d/%d\n", scale_factor, n, d);
> + fnotice (stderr, "scale_factor is %f or %d/%d\n", scale_factor, n, d);
>
> /* Scaling the counters. */
> for (gi_ptr = profile; gi_ptr; gi_ptr = gi_ptr->next)
> @@ -1167,7 +1192,7 @@ gcov_profile_normalize (struct gcov_info *profile,
> scale_factor = (float)max_val / curr_max_val;
> #if !defined (_WIN32)
> if (verbose)
> - fnotice (stdout, "max_val is %lld\n", (long long) curr_max_val);
> + fnotice (stderr, "max_val is %lld\n", (long long) curr_max_val);
> #endif
>
> return gcov_profile_scale (profile, scale_factor, 0, 0);
>
> --
> Teresa Johnson | Software Engineer | tejohn...@google.com | 408-460-2413
