[GOOGLE] Fix LIPO COMDAT fixup and gcov-tool interactions
Teresa Johnson
tejohnson@google.com
Tue Sep 16 14:57:00 GMT 2014
On Mon, Sep 15, 2014 at 9:29 PM, Xinliang David Li <davidxl@google.com> wrote:
> 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?
The zero_counts array is used to pass info back to the caller in
libgcov-driver.cc (dyn_cgraph_node), which is where it is allocated.
That routine does not have access to the dyn-ipa cgraph.
Teresa
>
> David
>
> On Fri, Sep 12, 2014 at 4:31 PM, Teresa Johnson <tejohnson@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 <tejohnson@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 | tejohnson@google.com | 408-460-2413
--
Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413
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