diff mbox

[RFC] libgcov.c re-factoring and offline profile-tool

Message ID CAF1bQ=THYY8NqoJ0XDYxnFS9=j9P6-5nLwA6nX1bA+0v1zmUoQ@mail.gmail.com
State New
Headers show

Commit Message

Rong Xu Nov. 4, 2013, 10:43 p.m. UTC
Honza, Thanks for the comments!
Attached is the patch.
Passed spec2006 fdo build and profiledbootstrap in gcc.
I'm doing some other tests.

-Rong

On Mon, Nov 4, 2013 at 1:55 AM, Jan Hubicka <hubicka@ucw.cz> wrote:
>> Thanks! Can you attach the patch file for the proposed change?
>>
>> David
>>
>> On Fri, Nov 1, 2013 at 2:08 PM, Rong Xu <xur@google.com> wrote:
>> > libgcov.c is the main file to generate libgcov.a. This single source generates
>> > 21 object files and then archives to a library. These objects are of
>> > very different purposes but they are in the same file guarded by various macros.
>> > The source file becomes quite large and its readability becomes very
>> > low. In its current state:
>> > 1) The code is very hard to understand by new developers;
>
> Agreed, libgcov has became hard to maintain since several parts are written
> in very low-level way.
>> > 2) It makes regressions more likely when making simple changes;
>> > More importantly,
>> > 3) it makes code reuse/sharing very difficult. For instance, Using
>> > libgcov to implement an offline profile tool (see below); kernel FDO
>> > support etc.
>
> Yep, it was my longer term plan to do this, too.
>> >
>> > We came to this issue when working on an offline tool to handle
>> > profile counters.
>> > Our plan is to have a profile-tool can merge, diff, collect statistics, and
>> > better dump raw profile counters. This is one of the most requested features
>> > from out internal users. This tool can also be very useful for any FDO/coverage
>> > users. In the first part of tool, we want to have the weight
>> > merge. Again, to reuse the code, we have to change libgcov.c. But we don't want
>> > to further diverge libgcov.a in our google branches from the trunk.
>> >
>> > Another issue in libgcov.c is function gcov_exit(). It is a huge function
>> > with about 467 lines of code. This function traverses gcov_list and dumps all
>> > the gcda files. The code for merging the gcda files also sits in the same
>> >  function. The structure makes the code-reuse and extension really difficult
>> > (like in kernel FDO, we have to break this function to reuse some of the code).
>> >
>> > We propose to break gcov_exit into smaller functions and split libgcov.c into
>> > several files. Our plan for profile-tool is listed in (3).
>> >
>> > 1. break gcov_exit() into the following structure:
>> >    gcov_exit()
>> >       --> gcov_exit_compute_summary()
>> >       --> allocate_filename_struct()
>> >           for gi_ptr in gcov_list
>> >             --> gcov_exit_dump_gcov()
>> >                    --> gcov_exit_open_gcda_file()
>> >                    --> gcov_exit_merge_gcda ()
>> >                    --> gcov_exit_write_gcda ()
>
> Just a short comment that summaries are also produced during the merging - i.e. they are
> done on per-file basis. But otherwise I agree.
> We should be cureful to not increase footprint of libgcov much for embedded users, but
> I believe changes like this can be done w/o additional overhead in the optimized library.

The merge of summary has two parts. One is to find the summary to
merge to. That is in gcov_exit_merge_gcda().
The other part of do the actual merging of summary is in gcov_exit_dump_gcov().

I tried to keep the current work flow. So except for a few more calls,
I don't think there is much overhead.

>> >
>> > 2. split libgcov.c into the following files:
>> >      libgcov-profiler.c
>> >      libgcov-merge.c
>> >      libgcov-interface.c
>> >      libgcov-driver.c
>> >        libgcov-driver-system.c (source included into libgcov-driver.c)
>
> Seems resonable.  Splitting i/o stuff into separate module (driver) is something I planned
> for long time.  What is difference in between libgcov-interface and libgcov-driver?

Basically libgcov-driver handles all the dumping of gcov-info.
libgcov-interface is the API used by instrumentation, like the wrapper for fork.


>> >
>> > The details of the splitting:
>> > libgcov-interface.c
>> > /* This file contains API functions to other programs and the supporting
>> >    functions.  */
>> >   __gcov_dump()
>> >   __gcov_execl()
>> >   __gcov_execle()
>> >   __gcov_execlp()
>> >   __gcov_execv()
>> >   __gcov_execve()
>> >   __gcov_execvp()
>> >   __gcov_flush()
>> >   __gcov_fork()
>> >   __gcov_reset()
>> >   init_mx()
>> >   init_mx_once()
>> >
>> > libgcov-profiler.c
>> > /* This file contains runtime profile handlers.  */
>> >   variables:
>> >     __gcov_indirect_call_callee
>> >     __gcov_indirect_call_counters
>> >   functions:
>> >     __gcov_average_profiler()
>> >     __gcov_indirect_call_profiler()
>> >     __gcov_indirect_call_profiler_v2()
>> >     __gcov_interval_profiler()
>> >     __gcov_ior_profiler()
>> >     __gcov_one_value_profiler()
>> >     __gcov_one_value_profiler_body()
>> >     __gcov_pow2_profiler()
>> >
>> > libgcov-merge.c
>> > /* This file contains the merge functions for various counters.  */
>> >   functions:
>> >     __gcov_merge_add()
>> >     __gcov_merge_delta()
>> >     __gcov_merge_ior()
>> >     __gcov_merge_single()
>> >
>> > libcov-driver.c
>> > /* This file contains the gcov dumping functions. We separate the
>> >    system dependent part to libgcov-driver-system.c.  */
>> >   variables:
>> >     gcov_list
>> >     gcov_max_filename
>> >     gcov_dump_complete
>> >     ------ newly added file static variables --
>> >     this_prg
>> >     all_prg
>> >     crc32
>> >     gi_filename
>> >     fn_buffer
>> >     fn_tail
>> >     sum_buffer
>> >     next_sum_buffer
>> >     sum_tail
>> >     ----- end -----
>> >   functions:
>> >     free_fn_data()
>> >     buffer_fn_data()
>> >     crc32_unsigned()
>> >     gcov_version()
>> >     gcov_histogram_insert()
>> >     gcov_compute_histogram()
>> >     gcov_clear()
>> >     __gcov_init()
>> >     gcov_exit()
>> >     ------- newly added static functions --
>> >     gcov_exit_compute_summary ()
>> >     gcov_exit_merge_gcda()
>> >     gcov_exit_write_gcda()
>> >     gcov_exit_dump_gcov()
>> >     ----- end -----
>> >
>> > libgcov-driver-system.c
>> > /* system dependent part of ligcov-driver.c.  */
>> >   functions:
>> >     create_file_directory()
>> >     ------- newly added static functions --
>> >     gcov_error() /* This replaces all fprintf(stderr, ...) */
>> >     allocate_filename_struct()
>> >     gcov_exit_open_gcda_file()
>> >
>> > 3. add offline profile-tool support.
>> >    We will change the interface of merge functions to make it
>> >    take in-memory gcov_info list, and a weight as the arguments.
>> >
>> >    We will add libgcov-tool.c. It has two APIs:
>> >    (1) read_profile_dir(): read a profile directory and reconstruct the
>> >        gcov_info link list in-memory.
>> >    (2) merge_profiles(): merge two in-memory gcov_info link list.
>> >
>> >    We also add profile-tool.c in gcc directory. It will source-include
>> >    libgcov-tool.c and build a host binary. (We don't do library style
>> >    because that will need a hard dependence from gcc to libgcc).
>> >    profile-tool.c will mainly handle user options and the write-out of
>> >    gcov-info link list. Some changes in gcov-io.[ch] will be also needed.
>> >
>> > Thanks,
>
> Thanks, it all looks good to me.  One thing I also always wondered about is why
> libgcov ended up being partly in libgcc and partly in gcc (the headers) directory.
> It would make more sense to have libgcov directory like we have for other runtime
> libraries.
>
I agree with you -- it's better to have a seperate directoy for libgcov.

The other part should be re-refatored is the gcov-io.[ch]. I think they
are even messier than libgcov.c. I plan to clean them after libgcvo.c.

> Honza
>> >
>> > -Rong
2013-11-04  Rong Xu  <xur@google.com>

	* libgcc/libgcov.c: Delete as part of re-factoring.
	* libgcc/libgcov-profiler.c (__gcov_interval_profiler): Moved from
	libgcov.c
	(__gcov_pow2_profiler): Ditto.
	(__gcov_one_value_profiler_body): Ditto.
	(__gcov_one_value_profiler): Ditto.
	(__gcov_indirect_call_profiler): Ditto.
	(__gcov_indirect_call_profiler_v2): Ditto.
	(__gcov_average_profiler): Ditto.
	(__gcov_ior_profiler): Ditto.
	* libgcc/libgcov-driver.c (this_prg): Make it file scope
	static variable.
	(all_prg): Ditto.
	(crc32): Ditto.
	(gi_filename): Ditto.
	(fn_buffer): Ditto.
	(sum_buffer): Ditto.
        (struct gcov_filename_aux): New types to store auxiliary information
        for gi_filename.
	(gcov_version): Moved from libgcov.c.
	(crc32_unsigned): Ditto.
	(gcov_histogram_insert): Ditto.
	(gcov_compute_histogram): Ditto.
	(gcov_exit): Ditto.
	(gcov_clear): Ditto.
	(__gcov_init): Ditto.
	(gcov_exit_compute_summary): New function split from gcov_exit().
	(gcov_exit_merge_gcda): Ditto.
	(gcov_exit_write_gcda): Ditto.
	(gcov_exit_dump_gcov): Ditto.
	* libgcc/libgcov-interface.c (init_mx): Moved from libgcov.c.
	(init_mx_once): Ditto.
	(__gcov_flush): Ditto.
	(__gcov_reset): Ditto.
	(__gcov_dump): Ditto.
	(__gcov_fork): Ditto.
	(__gcov_execl): Ditto.
	(__gcov_execlp): Ditto.
	(__gcov_execle): Ditto.
	(__gcov_execv): Ditto.
	(__gcov_execvp): Ditto.
	(__gcov_execve): Ditto.
	* libgcc/libgcov-driver-system.c (gcov_error): New utility function.
	(allocate_filename_struct): New function split from gcov_exit().
	(gcov_exit_open_gcda_file): Ditto.
        (create_file_directory): Moved from libgcov.c.
	* libgcc/libgcov-merge.c:
	(__gcov_merge_add): Moved from libgcov.c.
	(__gcov_merge_ior): Ditto.
	(__gcov_merge_single): Ditto.
	(__gcov_merge_delta): Ditto.
	* libgcc/Makefile.in: Change to build newly added files. 
	* gcc/gcov-io.h (__gcov_merge_ior): Add the decl to avoid warning.

Comments

Rong Xu Nov. 4, 2013, 10:48 p.m. UTC | #1
BTW, this part of patch only does the re-factoring work.
I haven't finished the porting of profile-tool part of patch to the
trunk. They should be in a separate patch anyway.

-Rong

On Mon, Nov 4, 2013 at 2:43 PM, Rong Xu <xur@google.com> wrote:
> Honza, Thanks for the comments!
> Attached is the patch.
> Passed spec2006 fdo build and profiledbootstrap in gcc.
> I'm doing some other tests.
>
> -Rong
>
> On Mon, Nov 4, 2013 at 1:55 AM, Jan Hubicka <hubicka@ucw.cz> wrote:
>>> Thanks! Can you attach the patch file for the proposed change?
>>>
>>> David
>>>
>>> On Fri, Nov 1, 2013 at 2:08 PM, Rong Xu <xur@google.com> wrote:
>>> > libgcov.c is the main file to generate libgcov.a. This single source generates
>>> > 21 object files and then archives to a library. These objects are of
>>> > very different purposes but they are in the same file guarded by various macros.
>>> > The source file becomes quite large and its readability becomes very
>>> > low. In its current state:
>>> > 1) The code is very hard to understand by new developers;
>>
>> Agreed, libgcov has became hard to maintain since several parts are written
>> in very low-level way.
>>> > 2) It makes regressions more likely when making simple changes;
>>> > More importantly,
>>> > 3) it makes code reuse/sharing very difficult. For instance, Using
>>> > libgcov to implement an offline profile tool (see below); kernel FDO
>>> > support etc.
>>
>> Yep, it was my longer term plan to do this, too.
>>> >
>>> > We came to this issue when working on an offline tool to handle
>>> > profile counters.
>>> > Our plan is to have a profile-tool can merge, diff, collect statistics, and
>>> > better dump raw profile counters. This is one of the most requested features
>>> > from out internal users. This tool can also be very useful for any FDO/coverage
>>> > users. In the first part of tool, we want to have the weight
>>> > merge. Again, to reuse the code, we have to change libgcov.c. But we don't want
>>> > to further diverge libgcov.a in our google branches from the trunk.
>>> >
>>> > Another issue in libgcov.c is function gcov_exit(). It is a huge function
>>> > with about 467 lines of code. This function traverses gcov_list and dumps all
>>> > the gcda files. The code for merging the gcda files also sits in the same
>>> >  function. The structure makes the code-reuse and extension really difficult
>>> > (like in kernel FDO, we have to break this function to reuse some of the code).
>>> >
>>> > We propose to break gcov_exit into smaller functions and split libgcov.c into
>>> > several files. Our plan for profile-tool is listed in (3).
>>> >
>>> > 1. break gcov_exit() into the following structure:
>>> >    gcov_exit()
>>> >       --> gcov_exit_compute_summary()
>>> >       --> allocate_filename_struct()
>>> >           for gi_ptr in gcov_list
>>> >             --> gcov_exit_dump_gcov()
>>> >                    --> gcov_exit_open_gcda_file()
>>> >                    --> gcov_exit_merge_gcda ()
>>> >                    --> gcov_exit_write_gcda ()
>>
>> Just a short comment that summaries are also produced during the merging - i.e. they are
>> done on per-file basis. But otherwise I agree.
>> We should be cureful to not increase footprint of libgcov much for embedded users, but
>> I believe changes like this can be done w/o additional overhead in the optimized library.
>
> The merge of summary has two parts. One is to find the summary to
> merge to. That is in gcov_exit_merge_gcda().
> The other part of do the actual merging of summary is in gcov_exit_dump_gcov().
>
> I tried to keep the current work flow. So except for a few more calls,
> I don't think there is much overhead.
>
>>> >
>>> > 2. split libgcov.c into the following files:
>>> >      libgcov-profiler.c
>>> >      libgcov-merge.c
>>> >      libgcov-interface.c
>>> >      libgcov-driver.c
>>> >        libgcov-driver-system.c (source included into libgcov-driver.c)
>>
>> Seems resonable.  Splitting i/o stuff into separate module (driver) is something I planned
>> for long time.  What is difference in between libgcov-interface and libgcov-driver?
>
> Basically libgcov-driver handles all the dumping of gcov-info.
> libgcov-interface is the API used by instrumentation, like the wrapper for fork.
>
>
>>> >
>>> > The details of the splitting:
>>> > libgcov-interface.c
>>> > /* This file contains API functions to other programs and the supporting
>>> >    functions.  */
>>> >   __gcov_dump()
>>> >   __gcov_execl()
>>> >   __gcov_execle()
>>> >   __gcov_execlp()
>>> >   __gcov_execv()
>>> >   __gcov_execve()
>>> >   __gcov_execvp()
>>> >   __gcov_flush()
>>> >   __gcov_fork()
>>> >   __gcov_reset()
>>> >   init_mx()
>>> >   init_mx_once()
>>> >
>>> > libgcov-profiler.c
>>> > /* This file contains runtime profile handlers.  */
>>> >   variables:
>>> >     __gcov_indirect_call_callee
>>> >     __gcov_indirect_call_counters
>>> >   functions:
>>> >     __gcov_average_profiler()
>>> >     __gcov_indirect_call_profiler()
>>> >     __gcov_indirect_call_profiler_v2()
>>> >     __gcov_interval_profiler()
>>> >     __gcov_ior_profiler()
>>> >     __gcov_one_value_profiler()
>>> >     __gcov_one_value_profiler_body()
>>> >     __gcov_pow2_profiler()
>>> >
>>> > libgcov-merge.c
>>> > /* This file contains the merge functions for various counters.  */
>>> >   functions:
>>> >     __gcov_merge_add()
>>> >     __gcov_merge_delta()
>>> >     __gcov_merge_ior()
>>> >     __gcov_merge_single()
>>> >
>>> > libcov-driver.c
>>> > /* This file contains the gcov dumping functions. We separate the
>>> >    system dependent part to libgcov-driver-system.c.  */
>>> >   variables:
>>> >     gcov_list
>>> >     gcov_max_filename
>>> >     gcov_dump_complete
>>> >     ------ newly added file static variables --
>>> >     this_prg
>>> >     all_prg
>>> >     crc32
>>> >     gi_filename
>>> >     fn_buffer
>>> >     fn_tail
>>> >     sum_buffer
>>> >     next_sum_buffer
>>> >     sum_tail
>>> >     ----- end -----
>>> >   functions:
>>> >     free_fn_data()
>>> >     buffer_fn_data()
>>> >     crc32_unsigned()
>>> >     gcov_version()
>>> >     gcov_histogram_insert()
>>> >     gcov_compute_histogram()
>>> >     gcov_clear()
>>> >     __gcov_init()
>>> >     gcov_exit()
>>> >     ------- newly added static functions --
>>> >     gcov_exit_compute_summary ()
>>> >     gcov_exit_merge_gcda()
>>> >     gcov_exit_write_gcda()
>>> >     gcov_exit_dump_gcov()
>>> >     ----- end -----
>>> >
>>> > libgcov-driver-system.c
>>> > /* system dependent part of ligcov-driver.c.  */
>>> >   functions:
>>> >     create_file_directory()
>>> >     ------- newly added static functions --
>>> >     gcov_error() /* This replaces all fprintf(stderr, ...) */
>>> >     allocate_filename_struct()
>>> >     gcov_exit_open_gcda_file()
>>> >
>>> > 3. add offline profile-tool support.
>>> >    We will change the interface of merge functions to make it
>>> >    take in-memory gcov_info list, and a weight as the arguments.
>>> >
>>> >    We will add libgcov-tool.c. It has two APIs:
>>> >    (1) read_profile_dir(): read a profile directory and reconstruct the
>>> >        gcov_info link list in-memory.
>>> >    (2) merge_profiles(): merge two in-memory gcov_info link list.
>>> >
>>> >    We also add profile-tool.c in gcc directory. It will source-include
>>> >    libgcov-tool.c and build a host binary. (We don't do library style
>>> >    because that will need a hard dependence from gcc to libgcc).
>>> >    profile-tool.c will mainly handle user options and the write-out of
>>> >    gcov-info link list. Some changes in gcov-io.[ch] will be also needed.
>>> >
>>> > Thanks,
>>
>> Thanks, it all looks good to me.  One thing I also always wondered about is why
>> libgcov ended up being partly in libgcc and partly in gcc (the headers) directory.
>> It would make more sense to have libgcov directory like we have for other runtime
>> libraries.
>>
> I agree with you -- it's better to have a seperate directoy for libgcov.
>
> The other part should be re-refatored is the gcov-io.[ch]. I think they
> are even messier than libgcov.c. I plan to clean them after libgcvo.c.
>
>> Honza
>>> >
>>> > -Rong
Xinliang David Li Nov. 4, 2013, 10:50 p.m. UTC | #2
On Mon, Nov 4, 2013 at 2:43 PM, Rong Xu <xur@google.com> wrote:
> Honza, Thanks for the comments!
> Attached is the patch.
> Passed spec2006 fdo build and profiledbootstrap in gcc.
> I'm doing some other tests.
>
> -Rong
>
> On Mon, Nov 4, 2013 at 1:55 AM, Jan Hubicka <hubicka@ucw.cz> wrote:
>>> Thanks! Can you attach the patch file for the proposed change?
>>>
>>> David
>>>
>>> On Fri, Nov 1, 2013 at 2:08 PM, Rong Xu <xur@google.com> wrote:
>>> > libgcov.c is the main file to generate libgcov.a. This single source generates
>>> > 21 object files and then archives to a library. These objects are of
>>> > very different purposes but they are in the same file guarded by various macros.
>>> > The source file becomes quite large and its readability becomes very
>>> > low. In its current state:
>>> > 1) The code is very hard to understand by new developers;
>>
>> Agreed, libgcov has became hard to maintain since several parts are written
>> in very low-level way.
>>> > 2) It makes regressions more likely when making simple changes;
>>> > More importantly,
>>> > 3) it makes code reuse/sharing very difficult. For instance, Using
>>> > libgcov to implement an offline profile tool (see below); kernel FDO
>>> > support etc.
>>
>> Yep, it was my longer term plan to do this, too.
>>> >
>>> > We came to this issue when working on an offline tool to handle
>>> > profile counters.
>>> > Our plan is to have a profile-tool can merge, diff, collect statistics, and
>>> > better dump raw profile counters. This is one of the most requested features
>>> > from out internal users. This tool can also be very useful for any FDO/coverage
>>> > users. In the first part of tool, we want to have the weight
>>> > merge. Again, to reuse the code, we have to change libgcov.c. But we don't want
>>> > to further diverge libgcov.a in our google branches from the trunk.
>>> >
>>> > Another issue in libgcov.c is function gcov_exit(). It is a huge function
>>> > with about 467 lines of code. This function traverses gcov_list and dumps all
>>> > the gcda files. The code for merging the gcda files also sits in the same
>>> >  function. The structure makes the code-reuse and extension really difficult
>>> > (like in kernel FDO, we have to break this function to reuse some of the code).
>>> >
>>> > We propose to break gcov_exit into smaller functions and split libgcov.c into
>>> > several files. Our plan for profile-tool is listed in (3).
>>> >
>>> > 1. break gcov_exit() into the following structure:
>>> >    gcov_exit()
>>> >       --> gcov_exit_compute_summary()
>>> >       --> allocate_filename_struct()
>>> >           for gi_ptr in gcov_list
>>> >             --> gcov_exit_dump_gcov()
>>> >                    --> gcov_exit_open_gcda_file()
>>> >                    --> gcov_exit_merge_gcda ()
>>> >                    --> gcov_exit_write_gcda ()
>>
>> Just a short comment that summaries are also produced during the merging - i.e. they are
>> done on per-file basis. But otherwise I agree.
>> We should be cureful to not increase footprint of libgcov much for embedded users, but
>> I believe changes like this can be done w/o additional overhead in the optimized library.
>
> The merge of summary has two parts. One is to find the summary to
> merge to. That is in gcov_exit_merge_gcda().
> The other part of do the actual merging of summary is in gcov_exit_dump_gcov().
>
> I tried to keep the current work flow. So except for a few more calls,
> I don't think there is much overhead.
>
>>> >
>>> > 2. split libgcov.c into the following files:
>>> >      libgcov-profiler.c
>>> >      libgcov-merge.c
>>> >      libgcov-interface.c
>>> >      libgcov-driver.c
>>> >        libgcov-driver-system.c (source included into libgcov-driver.c)
>>
>> Seems resonable.  Splitting i/o stuff into separate module (driver) is something I planned
>> for long time.  What is difference in between libgcov-interface and libgcov-driver?
>
> Basically libgcov-driver handles all the dumping of gcov-info.
> libgcov-interface is the API used by instrumentation, like the wrapper for fork.

Those are profiling related APIs exposed to user program.

David



>
>
>>> >
>>> > The details of the splitting:
>>> > libgcov-interface.c
>>> > /* This file contains API functions to other programs and the supporting
>>> >    functions.  */
>>> >   __gcov_dump()
>>> >   __gcov_execl()
>>> >   __gcov_execle()
>>> >   __gcov_execlp()
>>> >   __gcov_execv()
>>> >   __gcov_execve()
>>> >   __gcov_execvp()
>>> >   __gcov_flush()
>>> >   __gcov_fork()
>>> >   __gcov_reset()
>>> >   init_mx()
>>> >   init_mx_once()
>>> >
>>> > libgcov-profiler.c
>>> > /* This file contains runtime profile handlers.  */
>>> >   variables:
>>> >     __gcov_indirect_call_callee
>>> >     __gcov_indirect_call_counters
>>> >   functions:
>>> >     __gcov_average_profiler()
>>> >     __gcov_indirect_call_profiler()
>>> >     __gcov_indirect_call_profiler_v2()
>>> >     __gcov_interval_profiler()
>>> >     __gcov_ior_profiler()
>>> >     __gcov_one_value_profiler()
>>> >     __gcov_one_value_profiler_body()
>>> >     __gcov_pow2_profiler()
>>> >
>>> > libgcov-merge.c
>>> > /* This file contains the merge functions for various counters.  */
>>> >   functions:
>>> >     __gcov_merge_add()
>>> >     __gcov_merge_delta()
>>> >     __gcov_merge_ior()
>>> >     __gcov_merge_single()
>>> >
>>> > libcov-driver.c
>>> > /* This file contains the gcov dumping functions. We separate the
>>> >    system dependent part to libgcov-driver-system.c.  */
>>> >   variables:
>>> >     gcov_list
>>> >     gcov_max_filename
>>> >     gcov_dump_complete
>>> >     ------ newly added file static variables --
>>> >     this_prg
>>> >     all_prg
>>> >     crc32
>>> >     gi_filename
>>> >     fn_buffer
>>> >     fn_tail
>>> >     sum_buffer
>>> >     next_sum_buffer
>>> >     sum_tail
>>> >     ----- end -----
>>> >   functions:
>>> >     free_fn_data()
>>> >     buffer_fn_data()
>>> >     crc32_unsigned()
>>> >     gcov_version()
>>> >     gcov_histogram_insert()
>>> >     gcov_compute_histogram()
>>> >     gcov_clear()
>>> >     __gcov_init()
>>> >     gcov_exit()
>>> >     ------- newly added static functions --
>>> >     gcov_exit_compute_summary ()
>>> >     gcov_exit_merge_gcda()
>>> >     gcov_exit_write_gcda()
>>> >     gcov_exit_dump_gcov()
>>> >     ----- end -----
>>> >
>>> > libgcov-driver-system.c
>>> > /* system dependent part of ligcov-driver.c.  */
>>> >   functions:
>>> >     create_file_directory()
>>> >     ------- newly added static functions --
>>> >     gcov_error() /* This replaces all fprintf(stderr, ...) */
>>> >     allocate_filename_struct()
>>> >     gcov_exit_open_gcda_file()
>>> >
>>> > 3. add offline profile-tool support.
>>> >    We will change the interface of merge functions to make it
>>> >    take in-memory gcov_info list, and a weight as the arguments.
>>> >
>>> >    We will add libgcov-tool.c. It has two APIs:
>>> >    (1) read_profile_dir(): read a profile directory and reconstruct the
>>> >        gcov_info link list in-memory.
>>> >    (2) merge_profiles(): merge two in-memory gcov_info link list.
>>> >
>>> >    We also add profile-tool.c in gcc directory. It will source-include
>>> >    libgcov-tool.c and build a host binary. (We don't do library style
>>> >    because that will need a hard dependence from gcc to libgcc).
>>> >    profile-tool.c will mainly handle user options and the write-out of
>>> >    gcov-info link list. Some changes in gcov-io.[ch] will be also needed.
>>> >
>>> > Thanks,
>>
>> Thanks, it all looks good to me.  One thing I also always wondered about is why
>> libgcov ended up being partly in libgcc and partly in gcc (the headers) directory.
>> It would make more sense to have libgcov directory like we have for other runtime
>> libraries.
>>
> I agree with you -- it's better to have a seperate directoy for libgcov.
>
> The other part should be re-refatored is the gcov-io.[ch]. I think they
> are even messier than libgcov.c. I plan to clean them after libgcvo.c.
>
>> Honza
>>> >
>>> > -Rong
Xinliang David Li Nov. 5, 2013, 12:13 a.m. UTC | #3
I wonder if it makes sense to get rid of the conditional compile such as

#ifdef L_gcov_xxxxx
..

#endif

This has the advantage of producing slightly smaller instrumented
binary, but this benefit can also be achieved via -ffunction-sections
and let linker to garbage collect unused functions.

(probably as a follow up if it makes sense).

David

On Mon, Nov 4, 2013 at 2:43 PM, Rong Xu <xur@google.com> wrote:
> Honza, Thanks for the comments!
> Attached is the patch.
> Passed spec2006 fdo build and profiledbootstrap in gcc.
> I'm doing some other tests.
>
> -Rong
>
> On Mon, Nov 4, 2013 at 1:55 AM, Jan Hubicka <hubicka@ucw.cz> wrote:
>>> Thanks! Can you attach the patch file for the proposed change?
>>>
>>> David
>>>
>>> On Fri, Nov 1, 2013 at 2:08 PM, Rong Xu <xur@google.com> wrote:
>>> > libgcov.c is the main file to generate libgcov.a. This single source generates
>>> > 21 object files and then archives to a library. These objects are of
>>> > very different purposes but they are in the same file guarded by various macros.
>>> > The source file becomes quite large and its readability becomes very
>>> > low. In its current state:
>>> > 1) The code is very hard to understand by new developers;
>>
>> Agreed, libgcov has became hard to maintain since several parts are written
>> in very low-level way.
>>> > 2) It makes regressions more likely when making simple changes;
>>> > More importantly,
>>> > 3) it makes code reuse/sharing very difficult. For instance, Using
>>> > libgcov to implement an offline profile tool (see below); kernel FDO
>>> > support etc.
>>
>> Yep, it was my longer term plan to do this, too.
>>> >
>>> > We came to this issue when working on an offline tool to handle
>>> > profile counters.
>>> > Our plan is to have a profile-tool can merge, diff, collect statistics, and
>>> > better dump raw profile counters. This is one of the most requested features
>>> > from out internal users. This tool can also be very useful for any FDO/coverage
>>> > users. In the first part of tool, we want to have the weight
>>> > merge. Again, to reuse the code, we have to change libgcov.c. But we don't want
>>> > to further diverge libgcov.a in our google branches from the trunk.
>>> >
>>> > Another issue in libgcov.c is function gcov_exit(). It is a huge function
>>> > with about 467 lines of code. This function traverses gcov_list and dumps all
>>> > the gcda files. The code for merging the gcda files also sits in the same
>>> >  function. The structure makes the code-reuse and extension really difficult
>>> > (like in kernel FDO, we have to break this function to reuse some of the code).
>>> >
>>> > We propose to break gcov_exit into smaller functions and split libgcov.c into
>>> > several files. Our plan for profile-tool is listed in (3).
>>> >
>>> > 1. break gcov_exit() into the following structure:
>>> >    gcov_exit()
>>> >       --> gcov_exit_compute_summary()
>>> >       --> allocate_filename_struct()
>>> >           for gi_ptr in gcov_list
>>> >             --> gcov_exit_dump_gcov()
>>> >                    --> gcov_exit_open_gcda_file()
>>> >                    --> gcov_exit_merge_gcda ()
>>> >                    --> gcov_exit_write_gcda ()
>>
>> Just a short comment that summaries are also produced during the merging - i.e. they are
>> done on per-file basis. But otherwise I agree.
>> We should be cureful to not increase footprint of libgcov much for embedded users, but
>> I believe changes like this can be done w/o additional overhead in the optimized library.
>
> The merge of summary has two parts. One is to find the summary to
> merge to. That is in gcov_exit_merge_gcda().
> The other part of do the actual merging of summary is in gcov_exit_dump_gcov().
>
> I tried to keep the current work flow. So except for a few more calls,
> I don't think there is much overhead.
>
>>> >
>>> > 2. split libgcov.c into the following files:
>>> >      libgcov-profiler.c
>>> >      libgcov-merge.c
>>> >      libgcov-interface.c
>>> >      libgcov-driver.c
>>> >        libgcov-driver-system.c (source included into libgcov-driver.c)
>>
>> Seems resonable.  Splitting i/o stuff into separate module (driver) is something I planned
>> for long time.  What is difference in between libgcov-interface and libgcov-driver?
>
> Basically libgcov-driver handles all the dumping of gcov-info.
> libgcov-interface is the API used by instrumentation, like the wrapper for fork.
>
>
>>> >
>>> > The details of the splitting:
>>> > libgcov-interface.c
>>> > /* This file contains API functions to other programs and the supporting
>>> >    functions.  */
>>> >   __gcov_dump()
>>> >   __gcov_execl()
>>> >   __gcov_execle()
>>> >   __gcov_execlp()
>>> >   __gcov_execv()
>>> >   __gcov_execve()
>>> >   __gcov_execvp()
>>> >   __gcov_flush()
>>> >   __gcov_fork()
>>> >   __gcov_reset()
>>> >   init_mx()
>>> >   init_mx_once()
>>> >
>>> > libgcov-profiler.c
>>> > /* This file contains runtime profile handlers.  */
>>> >   variables:
>>> >     __gcov_indirect_call_callee
>>> >     __gcov_indirect_call_counters
>>> >   functions:
>>> >     __gcov_average_profiler()
>>> >     __gcov_indirect_call_profiler()
>>> >     __gcov_indirect_call_profiler_v2()
>>> >     __gcov_interval_profiler()
>>> >     __gcov_ior_profiler()
>>> >     __gcov_one_value_profiler()
>>> >     __gcov_one_value_profiler_body()
>>> >     __gcov_pow2_profiler()
>>> >
>>> > libgcov-merge.c
>>> > /* This file contains the merge functions for various counters.  */
>>> >   functions:
>>> >     __gcov_merge_add()
>>> >     __gcov_merge_delta()
>>> >     __gcov_merge_ior()
>>> >     __gcov_merge_single()
>>> >
>>> > libcov-driver.c
>>> > /* This file contains the gcov dumping functions. We separate the
>>> >    system dependent part to libgcov-driver-system.c.  */
>>> >   variables:
>>> >     gcov_list
>>> >     gcov_max_filename
>>> >     gcov_dump_complete
>>> >     ------ newly added file static variables --
>>> >     this_prg
>>> >     all_prg
>>> >     crc32
>>> >     gi_filename
>>> >     fn_buffer
>>> >     fn_tail
>>> >     sum_buffer
>>> >     next_sum_buffer
>>> >     sum_tail
>>> >     ----- end -----
>>> >   functions:
>>> >     free_fn_data()
>>> >     buffer_fn_data()
>>> >     crc32_unsigned()
>>> >     gcov_version()
>>> >     gcov_histogram_insert()
>>> >     gcov_compute_histogram()
>>> >     gcov_clear()
>>> >     __gcov_init()
>>> >     gcov_exit()
>>> >     ------- newly added static functions --
>>> >     gcov_exit_compute_summary ()
>>> >     gcov_exit_merge_gcda()
>>> >     gcov_exit_write_gcda()
>>> >     gcov_exit_dump_gcov()
>>> >     ----- end -----
>>> >
>>> > libgcov-driver-system.c
>>> > /* system dependent part of ligcov-driver.c.  */
>>> >   functions:
>>> >     create_file_directory()
>>> >     ------- newly added static functions --
>>> >     gcov_error() /* This replaces all fprintf(stderr, ...) */
>>> >     allocate_filename_struct()
>>> >     gcov_exit_open_gcda_file()
>>> >
>>> > 3. add offline profile-tool support.
>>> >    We will change the interface of merge functions to make it
>>> >    take in-memory gcov_info list, and a weight as the arguments.
>>> >
>>> >    We will add libgcov-tool.c. It has two APIs:
>>> >    (1) read_profile_dir(): read a profile directory and reconstruct the
>>> >        gcov_info link list in-memory.
>>> >    (2) merge_profiles(): merge two in-memory gcov_info link list.
>>> >
>>> >    We also add profile-tool.c in gcc directory. It will source-include
>>> >    libgcov-tool.c and build a host binary. (We don't do library style
>>> >    because that will need a hard dependence from gcc to libgcc).
>>> >    profile-tool.c will mainly handle user options and the write-out of
>>> >    gcov-info link list. Some changes in gcov-io.[ch] will be also needed.
>>> >
>>> > Thanks,
>>
>> Thanks, it all looks good to me.  One thing I also always wondered about is why
>> libgcov ended up being partly in libgcc and partly in gcc (the headers) directory.
>> It would make more sense to have libgcov directory like we have for other runtime
>> libraries.
>>
> I agree with you -- it's better to have a seperate directoy for libgcov.
>
> The other part should be re-refatored is the gcov-io.[ch]. I think they
> are even messier than libgcov.c. I plan to clean them after libgcvo.c.
>
>> Honza
>>> >
>>> > -Rong
Jan Hubicka Nov. 5, 2013, 9:18 a.m. UTC | #4
> I wonder if it makes sense to get rid of the conditional compile such as
> 
> #ifdef L_gcov_xxxxx
> ..
> 
> #endif
> 
> This has the advantage of producing slightly smaller instrumented
> binary, but this benefit can also be achieved via -ffunction-sections
> and let linker to garbage collect unused functions.
> 
> (probably as a follow up if it makes sense).

I believe we use this funny scheme primarily for targets that have no function
section support (and also the hand made splitting can be more sane).
For a low-level library like libgcov is that is supposed to have small footprint,
I guess the current scheme is resonable thing to do....

Honza
Jakub Jelinek Nov. 5, 2013, 9:23 a.m. UTC | #5
On Tue, Nov 05, 2013 at 10:18:50AM +0100, Jan Hubicka wrote:
> > I wonder if it makes sense to get rid of the conditional compile such as
> > 
> > #ifdef L_gcov_xxxxx
> > ..
> > 
> > #endif
> > 
> > This has the advantage of producing slightly smaller instrumented
> > binary, but this benefit can also be achieved via -ffunction-sections
> > and let linker to garbage collect unused functions.
> > 
> > (probably as a follow up if it makes sense).
> 
> I believe we use this funny scheme primarily for targets that have no function
> section support (and also the hand made splitting can be more sane).
> For a low-level library like libgcov is that is supposed to have small footprint,
> I guess the current scheme is resonable thing to do....

I think the #ifdef L* stuff is there mainly so that we have small
granularity in the *.a libraries (one function per object file), so that one
links only what is really required (at least, that is why libgcc.a does
that).  Of course, if there are many interdependencies between the functions
and you always essentially link in everything, the usefulness of that is
lower.

	Jakub
Xinliang David Li Nov. 5, 2013, 4:58 p.m. UTC | #6
Those functions are not referencing each other, but they get used in
different logical groups, so at least control granularity can be
improved. For instance,
1) all gcov user interfaces such as gcov_dump, gcov_flush, gcov_reset
are either not used at all, or all of them are used -- there is no
need to split this group. After Rong's refactoring (move them into a
separate file), the guarding macro can be removed for them
2) _gcov_merge_add is used by 4 different profilers, so it is almost
always linked in

It is unclear how other value profilers are used on other targets. For
x86, they are on by default, so the profiler bodies and merge
functions are also always linked in.

David

On Tue, Nov 5, 2013 at 1:23 AM, Jakub Jelinek <jakub@redhat.com> wrote:
> On Tue, Nov 05, 2013 at 10:18:50AM +0100, Jan Hubicka wrote:
>> > I wonder if it makes sense to get rid of the conditional compile such as
>> >
>> > #ifdef L_gcov_xxxxx
>> > ..
>> >
>> > #endif
>> >
>> > This has the advantage of producing slightly smaller instrumented
>> > binary, but this benefit can also be achieved via -ffunction-sections
>> > and let linker to garbage collect unused functions.
>> >
>> > (probably as a follow up if it makes sense).
>>
>> I believe we use this funny scheme primarily for targets that have no function
>> section support (and also the hand made splitting can be more sane).
>> For a low-level library like libgcov is that is supposed to have small footprint,
>> I guess the current scheme is resonable thing to do....
>
> I think the #ifdef L* stuff is there mainly so that we have small
> granularity in the *.a libraries (one function per object file), so that one
> links only what is really required (at least, that is why libgcc.a does
> that).  Of course, if there are many interdependencies between the functions
> and you always essentially link in everything, the usefulness of that is
> lower.
>
>         Jakub
Jan Hubicka Nov. 11, 2013, 3:02 p.m. UTC | #7
> 2013-11-04  Rong Xu  <xur@google.com>
> 
> 	* libgcc/libgcov.c: Delete as part of re-factoring.
> 	* libgcc/libgcov-profiler.c (__gcov_interval_profiler): Moved from
> 	libgcov.c
> 	(__gcov_pow2_profiler): Ditto.
> 	(__gcov_one_value_profiler_body): Ditto.
> 	(__gcov_one_value_profiler): Ditto.
> 	(__gcov_indirect_call_profiler): Ditto.
> 	(__gcov_indirect_call_profiler_v2): Ditto.
> 	(__gcov_average_profiler): Ditto.
> 	(__gcov_ior_profiler): Ditto.
> 	* libgcc/libgcov-driver.c (this_prg): Make it file scope
> 	static variable.
> 	(all_prg): Ditto.
> 	(crc32): Ditto.
> 	(gi_filename): Ditto.
> 	(fn_buffer): Ditto.
> 	(sum_buffer): Ditto.
>         (struct gcov_filename_aux): New types to store auxiliary information
>         for gi_filename.
> 	(gcov_version): Moved from libgcov.c.
> 	(crc32_unsigned): Ditto.
> 	(gcov_histogram_insert): Ditto.
> 	(gcov_compute_histogram): Ditto.
> 	(gcov_exit): Ditto.
> 	(gcov_clear): Ditto.
> 	(__gcov_init): Ditto.
> 	(gcov_exit_compute_summary): New function split from gcov_exit().
> 	(gcov_exit_merge_gcda): Ditto.
> 	(gcov_exit_write_gcda): Ditto.
> 	(gcov_exit_dump_gcov): Ditto.
> 	* libgcc/libgcov-interface.c (init_mx): Moved from libgcov.c.
> 	(init_mx_once): Ditto.
> 	(__gcov_flush): Ditto.
> 	(__gcov_reset): Ditto.
> 	(__gcov_dump): Ditto.
> 	(__gcov_fork): Ditto.
> 	(__gcov_execl): Ditto.
> 	(__gcov_execlp): Ditto.
> 	(__gcov_execle): Ditto.
> 	(__gcov_execv): Ditto.
> 	(__gcov_execvp): Ditto.
> 	(__gcov_execve): Ditto.
> 	* libgcc/libgcov-driver-system.c (gcov_error): New utility function.
> 	(allocate_filename_struct): New function split from gcov_exit().
> 	(gcov_exit_open_gcda_file): Ditto.
>         (create_file_directory): Moved from libgcov.c.
> 	* libgcc/libgcov-merge.c:
> 	(__gcov_merge_add): Moved from libgcov.c.
> 	(__gcov_merge_ior): Ditto.
> 	(__gcov_merge_single): Ditto.
> 	(__gcov_merge_delta): Ditto.
> 	* libgcc/Makefile.in: Change to build newly added files. 
> 	* gcc/gcov-io.h (__gcov_merge_ior): Add the decl to avoid warning.
> 

Hi,
the patch looks resonable. I take your word on the fact that there are no changes
in the code, I did not read it all ;)))
> Index: libgcc/Makefile.in
> ===================================================================
> --- libgcc/Makefile.in	(revision 204285)
> +++ libgcc/Makefile.in	(working copy)
> @@ -853,17 +853,37 @@ include $(iterator)
>  # Build libgcov components.
>  
>  # Defined in libgcov.c, included only in gcov library
> -LIBGCOV = _gcov _gcov_merge_add _gcov_merge_single _gcov_merge_delta \
> -    _gcov_fork _gcov_execl _gcov_execlp _gcov_execle \
> -    _gcov_execv _gcov_execvp _gcov_execve _gcov_reset _gcov_dump \
> -    _gcov_interval_profiler _gcov_pow2_profiler _gcov_one_value_profiler \
> +##LIBGCOV = _gcov _gcov_merge_add _gcov_merge_single _gcov_merge_delta \
> +##    _gcov_fork _gcov_execl _gcov_execlp _gcov_execle \
> +##    _gcov_execv _gcov_execvp _gcov_execve _gcov_reset _gcov_dump \
> +##    _gcov_interval_profiler _gcov_pow2_profiler _gcov_one_value_profiler \
> +##    _gcov_indirect_call_profiler _gcov_average_profiler _gcov_ior_profiler \
> +##    _gcov_merge_ior _gcov_indirect_call_profiler_v2

Probably no need for this commnet block.
> +
> +LIBGCOV_MERGE = _gcov_merge_add _gcov_merge_single _gcov_merge_delta _gcov_merge_ior
> +LIBGCOV_PROFILER = _gcov_interval_profiler _gcov_pow2_profiler _gcov_one_value_profiler \
>      _gcov_indirect_call_profiler _gcov_average_profiler _gcov_ior_profiler \
> -    _gcov_merge_ior _gcov_indirect_call_profiler_v2
> +    _gcov_indirect_call_profiler_v2
> +LIBGCOV_INTERFACE = _gcov_flush _gcov_fork _gcov_execl _gcov_execlp _gcov_execle \
> +    _gcov_execv _gcov_execvp _gcov_execve _gcov_reset _gcov_dump
> +LIBGCOV_DRIVER = _gcov 
>  
> -libgcov-objects = $(patsubst %,%$(objext),$(LIBGCOV))
> +libgcov-merge-objects = $(patsubst %,%$(objext),$(LIBGCOV_MERGE))
> +libgcov-profiler-objects = $(patsubst %,%$(objext),$(LIBGCOV_PROFILER))
> +libgcov-interface-objects = $(patsubst %,%$(objext),$(LIBGCOV_INTERFACE))
> +libgcov-driver-objects = $(patsubst %,%$(objext),$(LIBGCOV_DRIVER))
> +libgcov-objects = $(libgcov-merge-objects) $(libgcov-profiler-objects) \
> +                 $(libgcov-interface-objects) $(libgcov-driver-objects)
>  
> -$(libgcov-objects): %$(objext): $(srcdir)/libgcov.c
> -	$(gcc_compile) -DL$* -c $(srcdir)/libgcov.c
> +$(libgcov-merge-objects): %$(objext): $(srcdir)/libgcov-merge.c
> +	$(gcc_compile) -DL$* -c $(srcdir)/libgcov-merge.c
> +$(libgcov-profiler-objects): %$(objext): $(srcdir)/libgcov-profiler.c
> +	$(gcc_compile) -DL$* -c $(srcdir)/libgcov-profiler.c
> +$(libgcov-interface-objects): %$(objext): $(srcdir)/libgcov-interface.c
> +	$(gcc_compile) -DL$* -c $(srcdir)/libgcov-interface.c
> +$(libgcov-driver-objects): %$(objext): $(srcdir)/libgcov-driver.c \
> +  $(srcdir)/libgcov-driver-system.c
> +	$(gcc_compile) -DL$* -c $(srcdir)/libgcov-driver.c
>  
>  
>  # Static libraries.
> Index: gcc/gcov-io.h
> ===================================================================
> --- gcc/gcov-io.h	(revision 204285)
> +++ gcc/gcov-io.h	(working copy)
> @@ -515,6 +515,8 @@ extern void __gcov_merge_ior (gcov_type *, unsigne
>  extern void __gcov_interval_profiler (gcov_type *, gcov_type, int, unsigned);
>  extern void __gcov_pow2_profiler (gcov_type *, gcov_type);
>  extern void __gcov_one_value_profiler (gcov_type *, gcov_type);
> +extern void __gcov_indirect_call_profiler (gcov_type*, gcov_type,
> +                                           void*, void*);
>  extern void __gcov_indirect_call_profiler_v2 (gcov_type, void *);
>  extern void __gcov_average_profiler (gcov_type *, gcov_type);
>  extern void __gcov_ior_profiler (gcov_type *, gcov_type);

The patch is OK with the change above.
Honza
Rong Xu Nov. 11, 2013, 6:19 p.m. UTC | #8
On Mon, Nov 11, 2013 at 7:02 AM, Jan Hubicka <hubicka@ucw.cz> wrote:
>> 2013-11-04  Rong Xu  <xur@google.com>
>>
>>       * libgcc/libgcov.c: Delete as part of re-factoring.
>>       * libgcc/libgcov-profiler.c (__gcov_interval_profiler): Moved from
>>       libgcov.c
>>       (__gcov_pow2_profiler): Ditto.
>>       (__gcov_one_value_profiler_body): Ditto.
>>       (__gcov_one_value_profiler): Ditto.
>>       (__gcov_indirect_call_profiler): Ditto.
>>       (__gcov_indirect_call_profiler_v2): Ditto.
>>       (__gcov_average_profiler): Ditto.
>>       (__gcov_ior_profiler): Ditto.
>>       * libgcc/libgcov-driver.c (this_prg): Make it file scope
>>       static variable.
>>       (all_prg): Ditto.
>>       (crc32): Ditto.
>>       (gi_filename): Ditto.
>>       (fn_buffer): Ditto.
>>       (sum_buffer): Ditto.
>>         (struct gcov_filename_aux): New types to store auxiliary information
>>         for gi_filename.
>>       (gcov_version): Moved from libgcov.c.
>>       (crc32_unsigned): Ditto.
>>       (gcov_histogram_insert): Ditto.
>>       (gcov_compute_histogram): Ditto.
>>       (gcov_exit): Ditto.
>>       (gcov_clear): Ditto.
>>       (__gcov_init): Ditto.
>>       (gcov_exit_compute_summary): New function split from gcov_exit().
>>       (gcov_exit_merge_gcda): Ditto.
>>       (gcov_exit_write_gcda): Ditto.
>>       (gcov_exit_dump_gcov): Ditto.
>>       * libgcc/libgcov-interface.c (init_mx): Moved from libgcov.c.
>>       (init_mx_once): Ditto.
>>       (__gcov_flush): Ditto.
>>       (__gcov_reset): Ditto.
>>       (__gcov_dump): Ditto.
>>       (__gcov_fork): Ditto.
>>       (__gcov_execl): Ditto.
>>       (__gcov_execlp): Ditto.
>>       (__gcov_execle): Ditto.
>>       (__gcov_execv): Ditto.
>>       (__gcov_execvp): Ditto.
>>       (__gcov_execve): Ditto.
>>       * libgcc/libgcov-driver-system.c (gcov_error): New utility function.
>>       (allocate_filename_struct): New function split from gcov_exit().
>>       (gcov_exit_open_gcda_file): Ditto.
>>         (create_file_directory): Moved from libgcov.c.
>>       * libgcc/libgcov-merge.c:
>>       (__gcov_merge_add): Moved from libgcov.c.
>>       (__gcov_merge_ior): Ditto.
>>       (__gcov_merge_single): Ditto.
>>       (__gcov_merge_delta): Ditto.
>>       * libgcc/Makefile.in: Change to build newly added files.
>>       * gcc/gcov-io.h (__gcov_merge_ior): Add the decl to avoid warning.
>>
>
> Hi,
> the patch looks resonable. I take your word on the fact that there are no changes
> in the code, I did not read it all ;)))

We did split gcov_exit() into more functions.
But, semantically the code is the same.

>> Index: libgcc/Makefile.in
>> ===================================================================
>> --- libgcc/Makefile.in        (revision 204285)
>> +++ libgcc/Makefile.in        (working copy)
>> @@ -853,17 +853,37 @@ include $(iterator)
>>  # Build libgcov components.
>>
>>  # Defined in libgcov.c, included only in gcov library
>> -LIBGCOV = _gcov _gcov_merge_add _gcov_merge_single _gcov_merge_delta \
>> -    _gcov_fork _gcov_execl _gcov_execlp _gcov_execle \
>> -    _gcov_execv _gcov_execvp _gcov_execve _gcov_reset _gcov_dump \
>> -    _gcov_interval_profiler _gcov_pow2_profiler _gcov_one_value_profiler \
>> +##LIBGCOV = _gcov _gcov_merge_add _gcov_merge_single _gcov_merge_delta \
>> +##    _gcov_fork _gcov_execl _gcov_execlp _gcov_execle \
>> +##    _gcov_execv _gcov_execvp _gcov_execve _gcov_reset _gcov_dump \
>> +##    _gcov_interval_profiler _gcov_pow2_profiler _gcov_one_value_profiler \
>> +##    _gcov_indirect_call_profiler _gcov_average_profiler _gcov_ior_profiler \
>> +##    _gcov_merge_ior _gcov_indirect_call_profiler_v2
>
> Probably no need for this commnet block.

Yes. I ready remove in the most recently patch.

>> +
>> +LIBGCOV_MERGE = _gcov_merge_add _gcov_merge_single _gcov_merge_delta _gcov_merge_ior
>> +LIBGCOV_PROFILER = _gcov_interval_profiler _gcov_pow2_profiler _gcov_one_value_profiler \
>>      _gcov_indirect_call_profiler _gcov_average_profiler _gcov_ior_profiler \
>> -    _gcov_merge_ior _gcov_indirect_call_profiler_v2
>> +    _gcov_indirect_call_profiler_v2
>> +LIBGCOV_INTERFACE = _gcov_flush _gcov_fork _gcov_execl _gcov_execlp _gcov_execle \
>> +    _gcov_execv _gcov_execvp _gcov_execve _gcov_reset _gcov_dump
>> +LIBGCOV_DRIVER = _gcov
>>
>> -libgcov-objects = $(patsubst %,%$(objext),$(LIBGCOV))
>> +libgcov-merge-objects = $(patsubst %,%$(objext),$(LIBGCOV_MERGE))
>> +libgcov-profiler-objects = $(patsubst %,%$(objext),$(LIBGCOV_PROFILER))
>> +libgcov-interface-objects = $(patsubst %,%$(objext),$(LIBGCOV_INTERFACE))
>> +libgcov-driver-objects = $(patsubst %,%$(objext),$(LIBGCOV_DRIVER))
>> +libgcov-objects = $(libgcov-merge-objects) $(libgcov-profiler-objects) \
>> +                 $(libgcov-interface-objects) $(libgcov-driver-objects)
>>
>> -$(libgcov-objects): %$(objext): $(srcdir)/libgcov.c
>> -     $(gcc_compile) -DL$* -c $(srcdir)/libgcov.c
>> +$(libgcov-merge-objects): %$(objext): $(srcdir)/libgcov-merge.c
>> +     $(gcc_compile) -DL$* -c $(srcdir)/libgcov-merge.c
>> +$(libgcov-profiler-objects): %$(objext): $(srcdir)/libgcov-profiler.c
>> +     $(gcc_compile) -DL$* -c $(srcdir)/libgcov-profiler.c
>> +$(libgcov-interface-objects): %$(objext): $(srcdir)/libgcov-interface.c
>> +     $(gcc_compile) -DL$* -c $(srcdir)/libgcov-interface.c
>> +$(libgcov-driver-objects): %$(objext): $(srcdir)/libgcov-driver.c \
>> +  $(srcdir)/libgcov-driver-system.c
>> +     $(gcc_compile) -DL$* -c $(srcdir)/libgcov-driver.c
>>
>>
>>  # Static libraries.
>> Index: gcc/gcov-io.h
>> ===================================================================
>> --- gcc/gcov-io.h     (revision 204285)
>> +++ gcc/gcov-io.h     (working copy)
>> @@ -515,6 +515,8 @@ extern void __gcov_merge_ior (gcov_type *, unsigne
>>  extern void __gcov_interval_profiler (gcov_type *, gcov_type, int, unsigned);
>>  extern void __gcov_pow2_profiler (gcov_type *, gcov_type);
>>  extern void __gcov_one_value_profiler (gcov_type *, gcov_type);
>> +extern void __gcov_indirect_call_profiler (gcov_type*, gcov_type,
>> +                                           void*, void*);
>>  extern void __gcov_indirect_call_profiler_v2 (gcov_type, void *);
>>  extern void __gcov_average_profiler (gcov_type *, gcov_type);
>>  extern void __gcov_ior_profiler (gcov_type *, gcov_type);
>
> The patch is OK with the change above.

Thanks for the OK. I'll do some final tests on a clean client. Then I'll commit.

> Honza
Rong Xu Nov. 13, 2013, 12:27 a.m. UTC | #9
The patch was checked in as r204730.

Tested with
configure with --enable-languages=all,obj-c++
(ada is currently broken, so I was not be able test)
bootstrap and profiledbootstrap
regression for -m32 and -m64.
spec2006

The only semantic change is __gcov_flush() used to be under L_gcov.
I put the function to libgcov-interface.c and made it under
L_gcov_flush (newly added).
So if you need this function, you have to enable L_gcov_flush in the
libgcc/Makefile.in.

Thanks,

-Rong

On Mon, Nov 11, 2013 at 10:19 AM, Rong Xu <xur@google.com> wrote:
> On Mon, Nov 11, 2013 at 7:02 AM, Jan Hubicka <hubicka@ucw.cz> wrote:
>>> 2013-11-04  Rong Xu  <xur@google.com>
>>>
>>>       * libgcc/libgcov.c: Delete as part of re-factoring.
>>>       * libgcc/libgcov-profiler.c (__gcov_interval_profiler): Moved from
>>>       libgcov.c
>>>       (__gcov_pow2_profiler): Ditto.
>>>       (__gcov_one_value_profiler_body): Ditto.
>>>       (__gcov_one_value_profiler): Ditto.
>>>       (__gcov_indirect_call_profiler): Ditto.
>>>       (__gcov_indirect_call_profiler_v2): Ditto.
>>>       (__gcov_average_profiler): Ditto.
>>>       (__gcov_ior_profiler): Ditto.
>>>       * libgcc/libgcov-driver.c (this_prg): Make it file scope
>>>       static variable.
>>>       (all_prg): Ditto.
>>>       (crc32): Ditto.
>>>       (gi_filename): Ditto.
>>>       (fn_buffer): Ditto.
>>>       (sum_buffer): Ditto.
>>>         (struct gcov_filename_aux): New types to store auxiliary information
>>>         for gi_filename.
>>>       (gcov_version): Moved from libgcov.c.
>>>       (crc32_unsigned): Ditto.
>>>       (gcov_histogram_insert): Ditto.
>>>       (gcov_compute_histogram): Ditto.
>>>       (gcov_exit): Ditto.
>>>       (gcov_clear): Ditto.
>>>       (__gcov_init): Ditto.
>>>       (gcov_exit_compute_summary): New function split from gcov_exit().
>>>       (gcov_exit_merge_gcda): Ditto.
>>>       (gcov_exit_write_gcda): Ditto.
>>>       (gcov_exit_dump_gcov): Ditto.
>>>       * libgcc/libgcov-interface.c (init_mx): Moved from libgcov.c.
>>>       (init_mx_once): Ditto.
>>>       (__gcov_flush): Ditto.
>>>       (__gcov_reset): Ditto.
>>>       (__gcov_dump): Ditto.
>>>       (__gcov_fork): Ditto.
>>>       (__gcov_execl): Ditto.
>>>       (__gcov_execlp): Ditto.
>>>       (__gcov_execle): Ditto.
>>>       (__gcov_execv): Ditto.
>>>       (__gcov_execvp): Ditto.
>>>       (__gcov_execve): Ditto.
>>>       * libgcc/libgcov-driver-system.c (gcov_error): New utility function.
>>>       (allocate_filename_struct): New function split from gcov_exit().
>>>       (gcov_exit_open_gcda_file): Ditto.
>>>         (create_file_directory): Moved from libgcov.c.
>>>       * libgcc/libgcov-merge.c:
>>>       (__gcov_merge_add): Moved from libgcov.c.
>>>       (__gcov_merge_ior): Ditto.
>>>       (__gcov_merge_single): Ditto.
>>>       (__gcov_merge_delta): Ditto.
>>>       * libgcc/Makefile.in: Change to build newly added files.
>>>       * gcc/gcov-io.h (__gcov_merge_ior): Add the decl to avoid warning.
>>>
>>
>> Hi,
>> the patch looks resonable. I take your word on the fact that there are no changes
>> in the code, I did not read it all ;)))
>
> We did split gcov_exit() into more functions.
> But, semantically the code is the same.
>
>>> Index: libgcc/Makefile.in
>>> ===================================================================
>>> --- libgcc/Makefile.in        (revision 204285)
>>> +++ libgcc/Makefile.in        (working copy)
>>> @@ -853,17 +853,37 @@ include $(iterator)
>>>  # Build libgcov components.
>>>
>>>  # Defined in libgcov.c, included only in gcov library
>>> -LIBGCOV = _gcov _gcov_merge_add _gcov_merge_single _gcov_merge_delta \
>>> -    _gcov_fork _gcov_execl _gcov_execlp _gcov_execle \
>>> -    _gcov_execv _gcov_execvp _gcov_execve _gcov_reset _gcov_dump \
>>> -    _gcov_interval_profiler _gcov_pow2_profiler _gcov_one_value_profiler \
>>> +##LIBGCOV = _gcov _gcov_merge_add _gcov_merge_single _gcov_merge_delta \
>>> +##    _gcov_fork _gcov_execl _gcov_execlp _gcov_execle \
>>> +##    _gcov_execv _gcov_execvp _gcov_execve _gcov_reset _gcov_dump \
>>> +##    _gcov_interval_profiler _gcov_pow2_profiler _gcov_one_value_profiler \
>>> +##    _gcov_indirect_call_profiler _gcov_average_profiler _gcov_ior_profiler \
>>> +##    _gcov_merge_ior _gcov_indirect_call_profiler_v2
>>
>> Probably no need for this commnet block.
>
> Yes. I ready remove in the most recently patch.
>
>>> +
>>> +LIBGCOV_MERGE = _gcov_merge_add _gcov_merge_single _gcov_merge_delta _gcov_merge_ior
>>> +LIBGCOV_PROFILER = _gcov_interval_profiler _gcov_pow2_profiler _gcov_one_value_profiler \
>>>      _gcov_indirect_call_profiler _gcov_average_profiler _gcov_ior_profiler \
>>> -    _gcov_merge_ior _gcov_indirect_call_profiler_v2
>>> +    _gcov_indirect_call_profiler_v2
>>> +LIBGCOV_INTERFACE = _gcov_flush _gcov_fork _gcov_execl _gcov_execlp _gcov_execle \
>>> +    _gcov_execv _gcov_execvp _gcov_execve _gcov_reset _gcov_dump
>>> +LIBGCOV_DRIVER = _gcov
>>>
>>> -libgcov-objects = $(patsubst %,%$(objext),$(LIBGCOV))
>>> +libgcov-merge-objects = $(patsubst %,%$(objext),$(LIBGCOV_MERGE))
>>> +libgcov-profiler-objects = $(patsubst %,%$(objext),$(LIBGCOV_PROFILER))
>>> +libgcov-interface-objects = $(patsubst %,%$(objext),$(LIBGCOV_INTERFACE))
>>> +libgcov-driver-objects = $(patsubst %,%$(objext),$(LIBGCOV_DRIVER))
>>> +libgcov-objects = $(libgcov-merge-objects) $(libgcov-profiler-objects) \
>>> +                 $(libgcov-interface-objects) $(libgcov-driver-objects)
>>>
>>> -$(libgcov-objects): %$(objext): $(srcdir)/libgcov.c
>>> -     $(gcc_compile) -DL$* -c $(srcdir)/libgcov.c
>>> +$(libgcov-merge-objects): %$(objext): $(srcdir)/libgcov-merge.c
>>> +     $(gcc_compile) -DL$* -c $(srcdir)/libgcov-merge.c
>>> +$(libgcov-profiler-objects): %$(objext): $(srcdir)/libgcov-profiler.c
>>> +     $(gcc_compile) -DL$* -c $(srcdir)/libgcov-profiler.c
>>> +$(libgcov-interface-objects): %$(objext): $(srcdir)/libgcov-interface.c
>>> +     $(gcc_compile) -DL$* -c $(srcdir)/libgcov-interface.c
>>> +$(libgcov-driver-objects): %$(objext): $(srcdir)/libgcov-driver.c \
>>> +  $(srcdir)/libgcov-driver-system.c
>>> +     $(gcc_compile) -DL$* -c $(srcdir)/libgcov-driver.c
>>>
>>>
>>>  # Static libraries.
>>> Index: gcc/gcov-io.h
>>> ===================================================================
>>> --- gcc/gcov-io.h     (revision 204285)
>>> +++ gcc/gcov-io.h     (working copy)
>>> @@ -515,6 +515,8 @@ extern void __gcov_merge_ior (gcov_type *, unsigne
>>>  extern void __gcov_interval_profiler (gcov_type *, gcov_type, int, unsigned);
>>>  extern void __gcov_pow2_profiler (gcov_type *, gcov_type);
>>>  extern void __gcov_one_value_profiler (gcov_type *, gcov_type);
>>> +extern void __gcov_indirect_call_profiler (gcov_type*, gcov_type,
>>> +                                           void*, void*);
>>>  extern void __gcov_indirect_call_profiler_v2 (gcov_type, void *);
>>>  extern void __gcov_average_profiler (gcov_type *, gcov_type);
>>>  extern void __gcov_ior_profiler (gcov_type *, gcov_type);
>>
>> The patch is OK with the change above.
>
> Thanks for the OK. I'll do some final tests on a clean client. Then I'll commit.
>
>> Honza
diff mbox

Patch

Index: libgcc/libgcov-profiler.c
===================================================================
--- libgcc/libgcov-profiler.c	(revision 0)
+++ libgcc/libgcov-profiler.c	(revision 0)
@@ -0,0 +1,208 @@ 
+/* Routines required for instrumenting a program.  */
+/* Compile this one with gcc.  */
+/* Copyright (C) 1989-2013 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+#include "tconfig.h"
+#include "tsystem.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "libgcc_tm.h"
+
+#if !defined(inhibit_libc)
+#define IN_LIBGCOV 1
+#include "gcov-io.h"
+
+#ifdef L_gcov_interval_profiler
+/* If VALUE is in interval <START, START + STEPS - 1>, then increases the
+   corresponding counter in COUNTERS.  If the VALUE is above or below
+   the interval, COUNTERS[STEPS] or COUNTERS[STEPS + 1] is increased
+   instead.  */
+
+void
+__gcov_interval_profiler (gcov_type *counters, gcov_type value,
+                          int start, unsigned steps)
+{
+  gcov_type delta = value - start;
+  if (delta < 0)
+    counters[steps + 1]++;
+  else if (delta >= steps)
+    counters[steps]++;
+  else
+    counters[delta]++;
+}
+#endif
+
+#ifdef L_gcov_pow2_profiler
+/* If VALUE is a power of two, COUNTERS[1] is incremented.  Otherwise
+   COUNTERS[0] is incremented.  */
+
+void
+__gcov_pow2_profiler (gcov_type *counters, gcov_type value)
+{
+  if (value & (value - 1))
+    counters[0]++;
+  else
+    counters[1]++;
+}
+#endif
+
+/* Tries to determine the most common value among its inputs.  Checks if the
+   value stored in COUNTERS[0] matches VALUE.  If this is the case, COUNTERS[1]
+   is incremented.  If this is not the case and COUNTERS[1] is not zero,
+   COUNTERS[1] is decremented.  Otherwise COUNTERS[1] is set to one and
+   VALUE is stored to COUNTERS[0].  This algorithm guarantees that if this
+   function is called more than 50% of the time with one value, this value
+   will be in COUNTERS[0] in the end.
+
+   In any case, COUNTERS[2] is incremented.  */
+
+static inline void
+__gcov_one_value_profiler_body (gcov_type *counters, gcov_type value)
+{
+  if (value == counters[0])
+    counters[1]++;
+  else if (counters[1] == 0)
+    {
+      counters[1] = 1;
+      counters[0] = value;
+    }
+  else
+    counters[1]--;
+  counters[2]++;
+}
+
+#ifdef L_gcov_one_value_profiler
+void
+__gcov_one_value_profiler (gcov_type *counters, gcov_type value)
+{
+  __gcov_one_value_profiler_body (counters, value);
+}
+#endif
+
+#ifdef L_gcov_indirect_call_profiler
+/* This function exist only for workaround of binutils bug 14342.
+   Once this compatibility hack is obsolette, it can be removed.  */
+
+/* By default, the C++ compiler will use function addresses in the
+   vtable entries.  Setting TARGET_VTABLE_USES_DESCRIPTORS to nonzero
+   tells the compiler to use function descriptors instead.  The value
+   of this macro says how many words wide the descriptor is (normally 2),
+   but it may be dependent on target flags.  Since we do not have access
+   to the target flags here we just check to see if it is set and use
+   that to set VTABLE_USES_DESCRIPTORS to 0 or 1.
+
+   It is assumed that the address of a function descriptor may be treated
+   as a pointer to a function.  */
+
+#ifdef TARGET_VTABLE_USES_DESCRIPTORS
+#define VTABLE_USES_DESCRIPTORS 1
+#else
+#define VTABLE_USES_DESCRIPTORS 0
+#endif
+
+/* Tries to determine the most common value among its inputs. */
+void
+__gcov_indirect_call_profiler (gcov_type* counter, gcov_type value,
+                               void* cur_func, void* callee_func)
+{
+  /* If the C++ virtual tables contain function descriptors then one
+     function may have multiple descriptors and we need to dereference
+     the descriptors to see if they point to the same function.  */
+  if (cur_func == callee_func
+      || (VTABLE_USES_DESCRIPTORS && callee_func
+          && *(void **) cur_func == *(void **) callee_func))
+    __gcov_one_value_profiler_body (counter, value);
+}
+
+#endif
+#ifdef L_gcov_indirect_call_profiler_v2
+
+/* These two variables are used to actually track caller and callee.  Keep
+   them in TLS memory so races are not common (they are written to often).
+   The variables are set directly by GCC instrumented code, so declaration
+   here must match one in tree-profile.c  */
+
+#if defined(HAVE_CC_TLS) && !defined (USE_EMUTLS)
+__thread
+#endif
+void * __gcov_indirect_call_callee;
+#if defined(HAVE_CC_TLS) && !defined (USE_EMUTLS)
+__thread
+#endif
+gcov_type * __gcov_indirect_call_counters;
+
+/* By default, the C++ compiler will use function addresses in the
+   vtable entries.  Setting TARGET_VTABLE_USES_DESCRIPTORS to nonzero
+   tells the compiler to use function descriptors instead.  The value
+   of this macro says how many words wide the descriptor is (normally 2),
+   but it may be dependent on target flags.  Since we do not have access
+   to the target flags here we just check to see if it is set and use
+   that to set VTABLE_USES_DESCRIPTORS to 0 or 1.
+
+   It is assumed that the address of a function descriptor may be treated
+   as a pointer to a function.  */
+
+#ifdef TARGET_VTABLE_USES_DESCRIPTORS
+#define VTABLE_USES_DESCRIPTORS 1
+#else
+#define VTABLE_USES_DESCRIPTORS 0
+#endif
+
+/* Tries to determine the most common value among its inputs. */
+void
+__gcov_indirect_call_profiler_v2 (gcov_type value, void* cur_func)
+{
+  /* If the C++ virtual tables contain function descriptors then one
+     function may have multiple descriptors and we need to dereference
+     the descriptors to see if they point to the same function.  */
+  if (cur_func == __gcov_indirect_call_callee
+      || (VTABLE_USES_DESCRIPTORS && __gcov_indirect_call_callee
+          && *(void **) cur_func == *(void **) __gcov_indirect_call_callee))
+    __gcov_one_value_profiler_body (__gcov_indirect_call_counters, value);
+}
+#endif
+
+#ifdef L_gcov_average_profiler
+/* Increase corresponding COUNTER by VALUE.  FIXME: Perhaps we want
+   to saturate up.  */
+
+void
+__gcov_average_profiler (gcov_type *counters, gcov_type value)
+{
+  counters[0] += value;
+  counters[1] ++;
+}
+#endif
+
+#ifdef L_gcov_ior_profiler
+/* Bitwise-OR VALUE into COUNTER.  */
+
+void
+__gcov_ior_profiler (gcov_type *counters, gcov_type value)
+{
+  *counters |= value;
+}
+#endif
+
+#endif /* inhibit_libc */
Index: libgcc/libgcov-driver.c
===================================================================
--- libgcc/libgcov-driver.c	(revision 0)
+++ libgcc/libgcov-driver.c	(revision 0)
@@ -0,0 +1,819 @@ 
+/* Routines required for instrumenting a program.  */
+/* Compile this one with gcc.  */
+/* Copyright (C) 1989-2013 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+#include "tconfig.h"
+#include "tsystem.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "libgcc_tm.h"
+
+#if defined(inhibit_libc)
+#define IN_LIBGCOV (-1)
+#else
+#define IN_LIBGCOV 1
+#if defined(L_gcov)
+#define GCOV_LINKAGE /* nothing */
+#endif
+#endif
+#include "gcov-io.h"
+
+#if defined(inhibit_libc)
+/* If libc and its header files are not available, provide dummy functions.  */
+
+#if defined(L_gcov)
+void __gcov_init (struct gcov_info *p __attribute__ ((unused))) {}
+#endif
+
+#else /* inhibit_libc */
+
+#include <string.h>
+#if GCOV_LOCKED
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/stat.h>
+#endif
+
+extern void gcov_clear (void) ATTRIBUTE_HIDDEN;
+extern void gcov_exit (void) ATTRIBUTE_HIDDEN;
+extern int gcov_dump_complete ATTRIBUTE_HIDDEN;
+
+#ifdef L_gcov
+#include "gcov-io.c"
+
+struct gcov_fn_buffer
+{
+  struct gcov_fn_buffer *next;
+  unsigned fn_ix;
+  struct gcov_fn_info info;
+  /* note gcov_fn_info ends in a trailing array.  */
+};
+
+struct gcov_summary_buffer
+{
+  struct gcov_summary_buffer *next;
+  struct gcov_summary summary;
+};
+
+/* Chain of per-object gcov structures.  */
+static struct gcov_info *gcov_list;
+
+/* Size of the longest file name. */
+static size_t gcov_max_filename = 0;
+
+/* Flag when the profile has already been dumped via __gcov_dump().  */
+int gcov_dump_complete = 0;
+
+/* A utility function for outputing errors.  */
+static int gcov_error (const char *, ...);
+
+static struct gcov_fn_buffer *
+free_fn_data (const struct gcov_info *gi_ptr, struct gcov_fn_buffer *buffer,
+              unsigned limit)
+{
+  struct gcov_fn_buffer *next;
+  unsigned ix, n_ctr = 0;
+
+  if (!buffer)
+    return 0;
+  next = buffer->next;
+
+  for (ix = 0; ix != limit; ix++)
+    if (gi_ptr->merge[ix])
+      free (buffer->info.ctrs[n_ctr++].values);
+  free (buffer);
+  return next;
+}
+
+static struct gcov_fn_buffer **
+buffer_fn_data (const char *filename, const struct gcov_info *gi_ptr,
+                struct gcov_fn_buffer **end_ptr, unsigned fn_ix)
+{
+  unsigned n_ctrs = 0, ix = 0;
+  struct gcov_fn_buffer *fn_buffer;
+  unsigned len;
+
+  for (ix = GCOV_COUNTERS; ix--;)
+    if (gi_ptr->merge[ix])
+      n_ctrs++;
+
+  len = sizeof (*fn_buffer) + sizeof (fn_buffer->info.ctrs[0]) * n_ctrs;
+  fn_buffer = (struct gcov_fn_buffer *)malloc (len);
+
+  if (!fn_buffer)
+    goto fail;
+
+  fn_buffer->next = 0;
+  fn_buffer->fn_ix = fn_ix;
+  fn_buffer->info.ident = gcov_read_unsigned ();
+  fn_buffer->info.lineno_checksum = gcov_read_unsigned ();
+  fn_buffer->info.cfg_checksum = gcov_read_unsigned ();
+
+  for (n_ctrs = ix = 0; ix != GCOV_COUNTERS; ix++)
+    {
+      gcov_unsigned_t length;
+      gcov_type *values;
+
+      if (!gi_ptr->merge[ix])
+        continue;
+
+      if (gcov_read_unsigned () != GCOV_TAG_FOR_COUNTER (ix))
+        {
+          len = 0;
+          goto fail;
+        }
+
+      length = GCOV_TAG_COUNTER_NUM (gcov_read_unsigned ());
+      len = length * sizeof (gcov_type);
+      values = (gcov_type *)malloc (len);
+      if (!values)
+        goto fail;
+
+      fn_buffer->info.ctrs[n_ctrs].num = length;
+      fn_buffer->info.ctrs[n_ctrs].values = values;
+
+      while (length--)
+        *values++ = gcov_read_counter ();
+      n_ctrs++;
+    }
+
+  *end_ptr = fn_buffer;
+  return &fn_buffer->next;
+
+fail:
+  gcov_error ("profiling:%s:Function %u %s %u \n", filename, fn_ix,
+              len ? "cannot allocate" : "counter mismatch", len ? len : ix);
+
+  return (struct gcov_fn_buffer **)free_fn_data (gi_ptr, fn_buffer, ix);
+}
+
+/* Add an unsigned value to the current crc */
+
+static gcov_unsigned_t
+crc32_unsigned (gcov_unsigned_t crc32, gcov_unsigned_t value)
+{
+  unsigned ix;
+
+  for (ix = 32; ix--; value <<= 1)
+    {
+      unsigned feedback;
+
+      feedback = (value ^ crc32) & 0x80000000 ? 0x04c11db7 : 0;
+      crc32 <<= 1;
+      crc32 ^= feedback;
+    }
+
+  return crc32;
+}
+
+/* Check if VERSION of the info block PTR matches libgcov one.
+   Return 1 on success, or zero in case of versions mismatch.
+   If FILENAME is not NULL, its value used for reporting purposes
+   instead of value from the info block.  */
+
+static int
+gcov_version (struct gcov_info *ptr, gcov_unsigned_t version,
+              const char *filename)
+{
+  if (version != GCOV_VERSION)
+    {
+      char v[4], e[4];
+
+      GCOV_UNSIGNED2STRING (v, version);
+      GCOV_UNSIGNED2STRING (e, GCOV_VERSION);
+
+      gcov_error ("profiling:%s:Version mismatch - expected %.4s got %.4s\n",
+                  filename? filename : ptr->filename, e, v);
+      return 0;
+    }
+  return 1;
+}
+
+/* Insert counter VALUE into HISTOGRAM.  */
+
+static void
+gcov_histogram_insert(gcov_bucket_type *histogram, gcov_type value)
+{
+  unsigned i;
+
+  i = gcov_histo_index(value);
+  histogram[i].num_counters++;
+  histogram[i].cum_value += value;
+  if (value < histogram[i].min_value)
+    histogram[i].min_value = value;
+}
+
+/* Computes a histogram of the arc counters to place in the summary SUM.  */
+
+static void
+gcov_compute_histogram (struct gcov_summary *sum)
+{
+  struct gcov_info *gi_ptr;
+  const struct gcov_fn_info *gfi_ptr;
+  const struct gcov_ctr_info *ci_ptr;
+  struct gcov_ctr_summary *cs_ptr;
+  unsigned t_ix, f_ix, ctr_info_ix, ix;
+  int h_ix;
+
+  /* This currently only applies to arc counters.  */
+  t_ix = GCOV_COUNTER_ARCS;
+
+  /* First check if there are any counts recorded for this counter.  */
+  cs_ptr = &(sum->ctrs[t_ix]);
+  if (!cs_ptr->num)
+    return;
+
+  for (h_ix = 0; h_ix < GCOV_HISTOGRAM_SIZE; h_ix++)
+    {
+      cs_ptr->histogram[h_ix].num_counters = 0;
+      cs_ptr->histogram[h_ix].min_value = cs_ptr->run_max;
+      cs_ptr->histogram[h_ix].cum_value = 0;
+    }
+
+  /* Walk through all the per-object structures and record each of
+     the count values in histogram.  */
+  for (gi_ptr = gcov_list; gi_ptr; gi_ptr = gi_ptr->next)
+    {
+      if (!gi_ptr->merge[t_ix])
+        continue;
+
+      /* Find the appropriate index into the gcov_ctr_info array
+         for the counter we are currently working on based on the
+         existence of the merge function pointer for this object.  */
+      for (ix = 0, ctr_info_ix = 0; ix < t_ix; ix++)
+        {
+          if (gi_ptr->merge[ix])
+            ctr_info_ix++;
+        }
+      for (f_ix = 0; f_ix != gi_ptr->n_functions; f_ix++)
+        {
+          gfi_ptr = gi_ptr->functions[f_ix];
+
+          if (!gfi_ptr || gfi_ptr->key != gi_ptr)
+            continue;
+
+          ci_ptr = &gfi_ptr->ctrs[ctr_info_ix];
+          for (ix = 0; ix < ci_ptr->num; ix++)
+            gcov_histogram_insert (cs_ptr->histogram, ci_ptr->values[ix]);
+        }
+    }
+}
+
+/* summary for program.  */
+static struct gcov_summary this_prg;
+#if !GCOV_LOCKED
+/* summary for all instances of program.  */
+static struct gcov_summary all_prg;
+#endif
+/* crc32 for this program.  */
+static gcov_unsigned_t crc32;
+/* gcda filename.  */
+static char *gi_filename;
+/* buffer for the fn_data from another program.  */
+static struct gcov_fn_buffer *fn_buffer;
+/* buffer for summary from other programs to be written out. */
+static struct gcov_summary_buffer *sum_buffer;
+
+/* This funtions computes the program level summary and the histo-gram.
+   It initializes ALL_PRG, computes CRC32, and stores the summary in
+   THIS_PRG. All these three variables are file statics.  */
+
+static void
+gcov_exit_compute_summary (void)
+{
+  struct gcov_info *gi_ptr;
+  const struct gcov_fn_info *gfi_ptr;
+  struct gcov_ctr_summary *cs_ptr;
+  const struct gcov_ctr_info *ci_ptr;
+  int f_ix;
+  unsigned t_ix;
+  gcov_unsigned_t c_num;
+
+#if !GCOV_LOCKED
+  memset (&all_prg, 0, sizeof (all_prg));
+#endif
+  /* Find the totals for this execution.  */
+  memset (&this_prg, 0, sizeof (this_prg));
+  for (gi_ptr = gcov_list; gi_ptr; gi_ptr = gi_ptr->next)
+    {
+      crc32 = crc32_unsigned (crc32, gi_ptr->stamp);
+      crc32 = crc32_unsigned (crc32, gi_ptr->n_functions);
+
+      for (f_ix = 0; (unsigned)f_ix != gi_ptr->n_functions; f_ix++)
+        {
+          gfi_ptr = gi_ptr->functions[f_ix];
+
+          if (gfi_ptr && gfi_ptr->key != gi_ptr)
+            gfi_ptr = 0;
+
+          crc32 = crc32_unsigned (crc32, gfi_ptr ? gfi_ptr->cfg_checksum : 0);
+          crc32 = crc32_unsigned (crc32,
+                                  gfi_ptr ? gfi_ptr->lineno_checksum : 0);
+          if (!gfi_ptr)
+            continue;
+
+          ci_ptr = gfi_ptr->ctrs;
+          for (t_ix = 0; t_ix != GCOV_COUNTERS_SUMMABLE; t_ix++)
+            {
+              if (!gi_ptr->merge[t_ix])
+                continue;
+
+              cs_ptr = &this_prg.ctrs[t_ix];
+              cs_ptr->num += ci_ptr->num;
+              crc32 = crc32_unsigned (crc32, ci_ptr->num);
+
+              for (c_num = 0; c_num < ci_ptr->num; c_num++)
+                {
+                  cs_ptr->sum_all += ci_ptr->values[c_num];
+                  if (cs_ptr->run_max < ci_ptr->values[c_num])
+                    cs_ptr->run_max = ci_ptr->values[c_num];
+                }
+              ci_ptr++;
+            }
+        }
+    }
+  gcov_compute_histogram (&this_prg);
+}
+
+/* A struct that bundles all the related information about the
+   gcda filename.  */
+struct gcov_filename_aux{
+  char *gi_filename_up;
+  int gcov_prefix_strip;
+  size_t prefix_length;
+};
+
+/* Including system dependent components. */
+#include "libgcov-driver-system.c"
+
+/* This function merges counters in GI_PTR to an existing gcda file.
+   Return 0 on success.
+   Return -1 on error. In this case, caller will goto read_fatal.  */
+
+static int
+gcov_exit_merge_gcda (struct gcov_info *gi_ptr,
+                      struct gcov_summary *prg_p,
+                      gcov_position_t *summary_pos_p,
+                      gcov_position_t *eof_pos_p)
+{
+  gcov_unsigned_t tag, length;
+  unsigned t_ix;
+  int f_ix;
+  int error = 0;
+  struct gcov_fn_buffer **fn_tail = &fn_buffer;
+  struct gcov_summary_buffer **sum_tail = &sum_buffer;
+
+  length = gcov_read_unsigned ();
+  if (!gcov_version (gi_ptr, length, gi_filename))
+    return -1;
+
+  length = gcov_read_unsigned ();
+  if (length != gi_ptr->stamp)
+    /* Read from a different compilation. Overwrite the file.  */
+    return 0;
+
+  /* Look for program summary.  */
+  for (f_ix = 0;;)
+    {
+      struct gcov_summary tmp;
+
+      *eof_pos_p = gcov_position ();
+      tag = gcov_read_unsigned ();
+      if (tag != GCOV_TAG_PROGRAM_SUMMARY)
+        break;
+
+      f_ix--;
+      length = gcov_read_unsigned ();
+      gcov_read_summary (&tmp);
+      if ((error = gcov_is_error ()))
+        goto read_error;
+      if (*summary_pos_p)
+        {
+          /* Save all summaries after the one that will be
+             merged into below. These will need to be rewritten
+             as histogram merging may change the number of non-zero
+             histogram entries that will be emitted, and thus the
+             size of the merged summary.  */
+          (*sum_tail) = (struct gcov_summary_buffer *)
+              malloc (sizeof(struct gcov_summary_buffer));
+          (*sum_tail)->summary = tmp;
+          (*sum_tail)->next = 0;
+          sum_tail = &((*sum_tail)->next);
+          goto next_summary;
+        }
+      if (tmp.checksum != crc32)
+        goto next_summary;
+
+      for (t_ix = 0; t_ix != GCOV_COUNTERS_SUMMABLE; t_ix++)
+        if (tmp.ctrs[t_ix].num != this_prg.ctrs[t_ix].num)
+          goto next_summary;
+      *prg_p = tmp;
+      *summary_pos_p = *eof_pos_p;
+
+    next_summary:;
+    }
+
+  /* Merge execution counts for each function.  */
+  for (f_ix = 0; (unsigned)f_ix != gi_ptr->n_functions;
+       f_ix++, tag = gcov_read_unsigned ())
+    {
+      const struct gcov_ctr_info *ci_ptr;
+      const struct gcov_fn_info *gfi_ptr = gi_ptr->functions[f_ix];
+
+      if (tag != GCOV_TAG_FUNCTION)
+        goto read_mismatch;
+
+      length = gcov_read_unsigned ();
+      if (!length)
+        /* This function did not appear in the other program.
+           We have nothing to merge.  */
+        continue;
+
+      if (length != GCOV_TAG_FUNCTION_LENGTH)
+        goto read_mismatch;
+
+      if (!gfi_ptr || gfi_ptr->key != gi_ptr)
+        {
+          /* This function appears in the other program.  We
+             need to buffer the information in order to write
+             it back out -- we'll be inserting data before
+             this point, so cannot simply keep the data in the
+             file.  */
+          fn_tail = buffer_fn_data (gi_filename,
+                                    gi_ptr, fn_tail, f_ix);
+          if (!fn_tail)
+            goto read_mismatch;
+          continue;
+        }
+
+      length = gcov_read_unsigned ();
+      if (length != gfi_ptr->ident)
+        goto read_mismatch;
+
+      length = gcov_read_unsigned ();
+      if (length != gfi_ptr->lineno_checksum)
+        goto read_mismatch;
+
+      length = gcov_read_unsigned ();
+      if (length != gfi_ptr->cfg_checksum)
+        goto read_mismatch;
+
+      ci_ptr = gfi_ptr->ctrs;
+      for (t_ix = 0; t_ix < GCOV_COUNTERS; t_ix++)
+        {
+          gcov_merge_fn merge = gi_ptr->merge[t_ix];
+
+          if (!merge)
+            continue;
+
+          tag = gcov_read_unsigned ();
+          length = gcov_read_unsigned ();
+          if (tag != GCOV_TAG_FOR_COUNTER (t_ix)
+              || length != GCOV_TAG_COUNTER_LENGTH (ci_ptr->num))
+            goto read_mismatch;
+          (*merge) (ci_ptr->values, ci_ptr->num);
+          ci_ptr++;
+        }
+      if ((error = gcov_is_error ()))
+        goto read_error;
+    }
+
+  if (tag)
+    {
+    read_mismatch:;
+      gcov_error ("profiling:%s:Merge mismatch for %s %u\n",
+                  gi_filename, f_ix >= 0 ? "function" : "summary",
+                  f_ix < 0 ? -1 - f_ix : f_ix);
+      return -1;
+    }
+  return 0;
+
+read_error:
+  gcov_error ("profiling:%s:%s merging\n", gi_filename,
+              error < 0 ? "Overflow": "Error");
+  return -1;
+}
+
+/* Write counters in GI_PTR and the summary in PRG to a gcda file. In
+   the case of appending to an existing file, SUMMARY_POS will be non-zero.
+   We will write the file starting from SUMMAY_POS.  */
+
+static void
+gcov_exit_write_gcda (const struct gcov_info *gi_ptr,
+                      const struct gcov_summary *prg_p,
+                      const gcov_position_t summary_pos)
+{
+  unsigned f_ix;
+  struct gcov_summary_buffer *next_sum_buffer;
+
+  /* Write out the data.  */
+  if (!summary_pos)
+    {
+      gcov_write_tag_length (GCOV_DATA_MAGIC, GCOV_VERSION);
+      gcov_write_unsigned (gi_ptr->stamp);
+    }
+  else
+    gcov_seek (summary_pos);
+
+  /* Generate whole program statistics.  */
+  gcov_write_summary (GCOV_TAG_PROGRAM_SUMMARY, prg_p);
+
+  /* Rewrite all the summaries that were after the summary we merged
+     into. This is necessary as the merged summary may have a different
+     size due to the number of non-zero histogram entries changing after
+     merging.  */
+
+  while (sum_buffer)
+    {
+      gcov_write_summary (GCOV_TAG_PROGRAM_SUMMARY, &sum_buffer->summary);
+      next_sum_buffer = sum_buffer->next;
+      free (sum_buffer);
+      sum_buffer = next_sum_buffer;
+    }
+
+  /* Write execution counts for each function.  */
+  for (f_ix = 0; f_ix != gi_ptr->n_functions; f_ix++)
+    {
+      unsigned buffered = 0;
+      const struct gcov_fn_info *gfi_ptr;
+      const struct gcov_ctr_info *ci_ptr;
+      gcov_unsigned_t length;
+      unsigned t_ix;
+
+      if (fn_buffer && fn_buffer->fn_ix == f_ix)
+        {
+          /* Buffered data from another program.  */
+          buffered = 1;
+          gfi_ptr = &fn_buffer->info;
+          length = GCOV_TAG_FUNCTION_LENGTH;
+        }
+      else
+        {
+          gfi_ptr = gi_ptr->functions[f_ix];
+          if (gfi_ptr && gfi_ptr->key == gi_ptr)
+            length = GCOV_TAG_FUNCTION_LENGTH;
+          else
+                length = 0;
+        }
+
+      gcov_write_tag_length (GCOV_TAG_FUNCTION, length);
+      if (!length)
+        continue;
+
+      gcov_write_unsigned (gfi_ptr->ident);
+      gcov_write_unsigned (gfi_ptr->lineno_checksum);
+      gcov_write_unsigned (gfi_ptr->cfg_checksum);
+
+      ci_ptr = gfi_ptr->ctrs;
+      for (t_ix = 0; t_ix < GCOV_COUNTERS; t_ix++)
+        {
+          gcov_unsigned_t n_counts;
+          gcov_type *c_ptr;
+
+          if (!gi_ptr->merge[t_ix])
+            continue;
+
+          n_counts = ci_ptr->num;
+          gcov_write_tag_length (GCOV_TAG_FOR_COUNTER (t_ix),
+                                 GCOV_TAG_COUNTER_LENGTH (n_counts));
+          c_ptr = ci_ptr->values;
+          while (n_counts--)
+            gcov_write_counter (*c_ptr++);
+          ci_ptr++;
+        }
+      if (buffered)
+        fn_buffer = free_fn_data (gi_ptr, fn_buffer, GCOV_COUNTERS);
+    }
+
+  gcov_write_unsigned (0);
+}
+
+/* Dump the coverage counts for one gcov_info object. We merge with existing
+   counts when possible, to avoid growing the .da files ad infinitum. We use
+   this program's checksum to make sure we only accumulate whole program
+   statistics to the correct summary. An object file might be embedded
+   in two separate programs, and we must keep the two program
+   summaries separate.  */
+
+static void
+gcov_exit_dump_gcov (struct gcov_info *gi_ptr, struct gcov_filename_aux *gf)
+{
+  struct gcov_summary prg; /* summary for this object over all
+                                  program.  */
+  struct gcov_ctr_summary *cs_prg, *cs_tprg;
+#if !GCOV_LOCKED
+  struct gcov_ctr_summary *cs_all;
+#endif
+  int error = 0, ret;
+  gcov_unsigned_t tag;
+  gcov_position_t summary_pos = 0;
+  gcov_position_t eof_pos = 0;
+  unsigned t_ix;
+
+  fn_buffer = 0;
+  sum_buffer = 0;
+
+  ret = gcov_exit_open_gcda_file (gi_ptr, gf);
+  if (ret != 0)
+    return;
+
+  tag = gcov_read_unsigned ();
+  if (tag)
+    {
+      /* Merge data from file.  */
+      if (tag != GCOV_DATA_MAGIC)
+        {
+          gcov_error ("profiling:%s:Not a gcov data file\n", gi_filename);
+          goto read_fatal;
+        }
+      ret = gcov_exit_merge_gcda (gi_ptr, &prg, &summary_pos, &eof_pos);
+      if (ret == -1)
+        goto read_fatal;
+    }
+
+  gcov_rewrite ();
+
+  if (!summary_pos)
+    {
+      memset (&prg, 0, sizeof (prg));
+      summary_pos = eof_pos;
+    }
+
+  /* Merge the summaries.  */
+  for (t_ix = 0; t_ix < GCOV_COUNTERS_SUMMABLE; t_ix++)
+    {
+      cs_prg = &prg.ctrs[t_ix];
+      cs_tprg = &this_prg.ctrs[t_ix];
+
+      if (gi_ptr->merge[t_ix])
+        {
+          if (!cs_prg->runs++)
+            cs_prg->num = cs_tprg->num;
+          cs_prg->sum_all += cs_tprg->sum_all;
+          if (cs_prg->run_max < cs_tprg->run_max)
+            cs_prg->run_max = cs_tprg->run_max;
+          cs_prg->sum_max += cs_tprg->run_max;
+          if (cs_prg->runs == 1)
+            memcpy (cs_prg->histogram, cs_tprg->histogram,
+                   sizeof (gcov_bucket_type) * GCOV_HISTOGRAM_SIZE);
+          else
+            gcov_histogram_merge (cs_prg->histogram, cs_tprg->histogram);
+        }
+      else if (cs_prg->runs)
+        {
+          gcov_error ("profiling:%s:Merge mismatch for summary.\n",
+                      gi_filename);
+          goto read_fatal;
+        }
+
+#if !GCOV_LOCKED
+      cs_all = &all_prg.ctrs[t_ix];
+      if (!cs_all->runs && cs_prg->runs)
+        {
+          cs_all->num = cs_prg->num;
+          cs_all->runs = cs_prg->runs;
+          cs_all->sum_all = cs_prg->sum_all;
+          cs_all->run_max = cs_prg->run_max;
+          cs_all->sum_max = cs_prg->sum_max;
+        }
+      else if (!all_prg.checksum
+               /* Don't compare the histograms, which may have slight
+                  variations depending on the order they were updated
+                  due to the truncating integer divides used in the
+                  merge.  */
+               && (cs_all->num != cs_prg->num
+                   || cs_all->runs != cs_prg->runs
+                   || cs_all->sum_all != cs_prg->sum_all
+                   || cs_all->run_max != cs_prg->run_max
+                   || cs_all->sum_max != cs_prg->sum_max))
+             {
+               gcov_error ("profiling:%s:Data file mismatch - some "
+                           "data files may have been concurrently "
+                           "updated without locking support\n", gi_filename);
+               all_prg.checksum = ~0u;
+             }
+#endif
+    }
+
+  prg.checksum = crc32;
+  gcov_exit_write_gcda (gi_ptr, &prg, summary_pos);
+  /* fall through */
+
+read_fatal:;
+  while (fn_buffer)
+    fn_buffer = free_fn_data (gi_ptr, fn_buffer, GCOV_COUNTERS);
+
+  if ((error = gcov_close ()))
+    gcov_error (error  < 0 ?
+                "profiling:%s:Overflow writing\n" :
+                "profiling:%s:Error writing\n",
+                gi_filename);
+}
+
+
+/* Dump all the coverage counts for the program. It first computes program
+   summary and then traverses gcov_list list and dumps the gcov_info
+   objects one by one.  */
+
+void
+gcov_exit (void)
+{
+  struct gcov_info *gi_ptr;
+  struct gcov_filename_aux gf;
+
+  /* Prevent the counters from being dumped a second time on exit when the
+     application already wrote out the profile using __gcov_dump().  */
+  if (gcov_dump_complete)
+    return;
+
+  gcov_exit_compute_summary ();
+
+  allocate_filename_struct (&gf);
+
+  /* Now merge each file.  */
+  for (gi_ptr = gcov_list; gi_ptr; gi_ptr = gi_ptr->next)
+    gcov_exit_dump_gcov (gi_ptr, &gf);
+
+  if (gi_filename)
+    free (gi_filename);
+}
+
+/* Reset all counters to zero.  */
+
+void
+gcov_clear (void)
+{
+  const struct gcov_info *gi_ptr;
+
+  for (gi_ptr = gcov_list; gi_ptr; gi_ptr = gi_ptr->next)
+    {
+      unsigned f_ix;
+
+      for (f_ix = 0; f_ix < gi_ptr->n_functions; f_ix++)
+        {
+          unsigned t_ix;
+          const struct gcov_fn_info *gfi_ptr = gi_ptr->functions[f_ix];
+
+          if (!gfi_ptr || gfi_ptr->key != gi_ptr)
+            continue;
+          const struct gcov_ctr_info *ci_ptr = gfi_ptr->ctrs;
+          for (t_ix = 0; t_ix != GCOV_COUNTERS; t_ix++)
+            {
+              if (!gi_ptr->merge[t_ix])
+                continue;
+
+              memset (ci_ptr->values, 0, sizeof (gcov_type) * ci_ptr->num);
+              ci_ptr++;
+            }
+        }
+    }
+}
+
+/* Add a new object file onto the bb chain.  Invoked automatically
+  when running an object file's global ctors.  */
+
+void
+__gcov_init (struct gcov_info *info)
+{
+  if (!info->version || !info->n_functions)
+    return;
+  if (gcov_version (info, info->version, 0))
+    {
+      size_t filename_length = strlen(info->filename);
+
+      /* Refresh the longest file name information */
+      if (filename_length > gcov_max_filename)
+        gcov_max_filename = filename_length;
+
+      if (!gcov_list)
+        atexit (gcov_exit);
+
+      info->next = gcov_list;
+      gcov_list = info;
+    }
+  info->version = 0;
+}
+
+#endif /* L_gcov */
+#endif /* inhibit_libc */
Index: libgcc/libgcov-interface.c
===================================================================
--- libgcc/libgcov-interface.c	(revision 0)
+++ libgcc/libgcov-interface.c	(revision 0)
@@ -0,0 +1,281 @@ 
+/* Routines required for instrumenting a program.  */
+/* Compile this one with gcc.  */
+/* Copyright (C) 1989-2013 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+#include "tconfig.h"
+#include "tsystem.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "libgcc_tm.h"
+#include "gthr.h"
+
+#if defined(inhibit_libc)
+#define IN_LIBGCOV (-1)
+#else
+#define IN_LIBGCOV 1
+#if defined(L_gcov_flush)
+#define GCOV_LINKAGE /* nothing */
+#endif
+#endif
+#include "gcov-io.h"
+
+#if defined(inhibit_libc)
+
+#ifdef L_gcov_flush
+void __gcov_flush (void) {}
+#endif
+
+#ifdef L_gcov_reset
+void __gcov_reset (void) {}
+#endif
+
+#ifdef L_gcov_dump
+void __gcov_dump (void) {}
+#endif
+
+#else
+
+extern void gcov_clear (void) ATTRIBUTE_HIDDEN;
+extern void gcov_exit (void) ATTRIBUTE_HIDDEN;
+extern int gcov_dump_complete ATTRIBUTE_HIDDEN;
+
+#ifdef L_gcov_flush
+
+#ifdef __GTHREAD_MUTEX_INIT
+ATTRIBUTE_HIDDEN __gthread_mutex_t __gcov_flush_mx = __GTHREAD_MUTEX_INIT;
+#define init_mx_once()
+#else
+__gthread_mutex_t __gcov_flush_mx ATTRIBUTE_HIDDEN;
+
+static void
+init_mx (void)
+{
+  __GTHREAD_MUTEX_INIT_FUNCTION (&__gcov_flush_mx);
+}
+static void
+init_mx_once (void)
+{
+  static __gthread_once_t once = __GTHREAD_ONCE_INIT;
+  __gthread_once (&once, init_mx);
+}
+#endif
+
+/* Called before fork or exec - write out profile information gathered so
+   far and reset it to zero.  This avoids duplication or loss of the
+   profile information gathered so far.  */
+
+void
+__gcov_flush (void)
+{
+  init_mx_once ();
+  __gthread_mutex_lock (&__gcov_flush_mx);
+
+  gcov_exit ();
+  gcov_clear ();
+
+  __gthread_mutex_unlock (&__gcov_flush_mx);
+}
+
+#endif /* L_gcov_flush */
+
+#ifdef L_gcov_reset
+
+/* Function that can be called from application to reset counters to zero,
+   in order to collect profile in region of interest.  */
+
+void
+__gcov_reset (void)
+{
+  gcov_clear ();
+  /* Re-enable dumping to support collecting profile in multiple regions
+     of interest.  */
+  gcov_dump_complete = 0;
+}
+
+#endif /* L_gcov_reset */
+
+#ifdef L_gcov_dump
+
+/* Function that can be called from application to write profile collected
+   so far, in order to collect profile in region of interest.  */
+
+void
+__gcov_dump (void)
+{
+  gcov_exit ();
+  /* Prevent profile from being dumped a second time on application exit.  */
+  gcov_dump_complete = 1;
+}
+
+#endif /* L_gcov_dump */
+
+
+#ifdef L_gcov_fork
+/* A wrapper for the fork function.  Flushes the accumulated profiling data, so
+   that they are not counted twice.  */
+
+pid_t
+__gcov_fork (void)
+{
+  pid_t pid;
+  extern __gthread_mutex_t __gcov_flush_mx;
+  __gcov_flush ();
+  pid = fork ();
+  if (pid == 0)
+    __GTHREAD_MUTEX_INIT_FUNCTION (&__gcov_flush_mx);
+  return pid;
+}
+#endif
+
+#ifdef L_gcov_execl
+/* A wrapper for the execl function.  Flushes the accumulated profiling data, so
+   that they are not lost.  */
+
+int
+__gcov_execl (const char *path, char *arg, ...)
+{
+  va_list ap, aq;
+  unsigned i, length;
+  char **args;
+
+  __gcov_flush ();
+
+  va_start (ap, arg);
+  va_copy (aq, ap);
+
+  length = 2;
+  while (va_arg (ap, char *))
+    length++;
+  va_end (ap);
+
+  args = (char **) alloca (length * sizeof (void *));
+  args[0] = arg;
+  for (i = 1; i < length; i++)
+    args[i] = va_arg (aq, char *);
+  va_end (aq);
+
+  return execv (path, args);
+}
+#endif
+
+#ifdef L_gcov_execlp
+/* A wrapper for the execlp function.  Flushes the accumulated profiling data, so
+   that they are not lost.  */
+
+int
+__gcov_execlp (const char *path, char *arg, ...)
+{
+  va_list ap, aq;
+  unsigned i, length;
+  char **args;
+
+  __gcov_flush ();
+
+  va_start (ap, arg);
+  va_copy (aq, ap);
+
+  length = 2;
+  while (va_arg (ap, char *))
+    length++;
+  va_end (ap);
+
+  args = (char **) alloca (length * sizeof (void *));
+  args[0] = arg;
+  for (i = 1; i < length; i++)
+    args[i] = va_arg (aq, char *);
+  va_end (aq);
+
+  return execvp (path, args);
+}
+#endif
+
+#ifdef L_gcov_execle
+/* A wrapper for the execle function.  Flushes the accumulated profiling data, so
+   that they are not lost.  */
+
+int
+__gcov_execle (const char *path, char *arg, ...)
+{
+  va_list ap, aq;
+  unsigned i, length;
+  char **args;
+  char **envp;
+
+  __gcov_flush ();
+
+  va_start (ap, arg);
+  va_copy (aq, ap);
+
+  length = 2;
+  while (va_arg (ap, char *))
+    length++;
+  va_end (ap);
+
+  args = (char **) alloca (length * sizeof (void *));
+  args[0] = arg;
+  for (i = 1; i < length; i++)
+    args[i] = va_arg (aq, char *);
+  envp = va_arg (aq, char **);
+  va_end (aq);
+
+  return execve (path, args, envp);
+}
+#endif
+
+#ifdef L_gcov_execv
+/* A wrapper for the execv function.  Flushes the accumulated profiling data, so
+   that they are not lost.  */
+
+int
+__gcov_execv (const char *path, char *const argv[])
+{
+  __gcov_flush ();
+  return execv (path, argv);
+}
+#endif
+
+#ifdef L_gcov_execvp
+/* A wrapper for the execvp function.  Flushes the accumulated profiling data, so
+   that they are not lost.  */
+
+int
+__gcov_execvp (const char *path, char *const argv[])
+{
+  __gcov_flush ();
+  return execvp (path, argv);
+}
+#endif
+
+#ifdef L_gcov_execve
+/* A wrapper for the execve function.  Flushes the accumulated profiling data, so
+   that they are not lost.  */
+
+int
+__gcov_execve (const char *path, char *const argv[], char *const envp[])
+{
+  __gcov_flush ();
+  return execve (path, argv, envp);
+}
+#endif
+#endif /* inhibit_libc */
Index: libgcc/libgcov.c
===================================================================
--- libgcc/libgcov.c	(revision 204285)
+++ libgcc/libgcov.c	(working copy)
@@ -1,1374 +0,0 @@ 
-/* Routines required for instrumenting a program.  */
-/* Compile this one with gcc.  */
-/* Copyright (C) 1989-2013 Free Software Foundation, Inc.
-
-This file is part of GCC.
-
-GCC is free software; you can redistribute it and/or modify it under
-the terms of the GNU General Public License as published by the Free
-Software Foundation; either version 3, or (at your option) any later
-version.
-
-GCC is distributed in the hope that it will be useful, but WITHOUT ANY
-WARRANTY; without even the implied warranty of MERCHANTABILITY or
-FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
-for more details.
-
-Under Section 7 of GPL version 3, you are granted additional
-permissions described in the GCC Runtime Library Exception, version
-3.1, as published by the Free Software Foundation.
-
-You should have received a copy of the GNU General Public License and
-a copy of the GCC Runtime Library Exception along with this program;
-see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
-<http://www.gnu.org/licenses/>.  */
-
-#include "tconfig.h"
-#include "tsystem.h"
-#include "coretypes.h"
-#include "tm.h"
-#include "libgcc_tm.h"
-#include "gthr.h"
-
-#if defined(inhibit_libc)
-#define IN_LIBGCOV (-1)
-#else
-#define IN_LIBGCOV 1
-#if defined(L_gcov)
-#define GCOV_LINKAGE /* nothing */
-#endif
-#endif
-#include "gcov-io.h"
-
-#if defined(inhibit_libc)
-/* If libc and its header files are not available, provide dummy functions.  */
-
-#ifdef L_gcov
-void __gcov_init (struct gcov_info *p __attribute__ ((unused))) {}
-void __gcov_flush (void) {}
-#endif
-
-#ifdef L_gcov_reset
-void __gcov_reset (void) {}
-#endif
-
-#ifdef L_gcov_dump
-void __gcov_dump (void) {}
-#endif
-
-#ifdef L_gcov_merge_add
-void __gcov_merge_add (gcov_type *counters  __attribute__ ((unused)),
-		       unsigned n_counters __attribute__ ((unused))) {}
-#endif
-
-#ifdef L_gcov_merge_single
-void __gcov_merge_single (gcov_type *counters  __attribute__ ((unused)),
-			  unsigned n_counters __attribute__ ((unused))) {}
-#endif
-
-#ifdef L_gcov_merge_delta
-void __gcov_merge_delta (gcov_type *counters  __attribute__ ((unused)),
-			 unsigned n_counters __attribute__ ((unused))) {}
-#endif
-
-#else
-
-#include <string.h>
-#if GCOV_LOCKED
-#include <fcntl.h>
-#include <errno.h>
-#include <sys/stat.h>
-#endif
-
-extern void gcov_clear (void) ATTRIBUTE_HIDDEN;
-extern void gcov_exit (void) ATTRIBUTE_HIDDEN;
-extern int gcov_dump_complete ATTRIBUTE_HIDDEN;
-
-#ifdef L_gcov
-#include "gcov-io.c"
-
-struct gcov_fn_buffer
-{
-  struct gcov_fn_buffer *next;
-  unsigned fn_ix;
-  struct gcov_fn_info info;
-  /* note gcov_fn_info ends in a trailing array.  */
-};
-
-struct gcov_summary_buffer
-{
-  struct gcov_summary_buffer *next;
-  struct gcov_summary summary;
-};
-
-/* Chain of per-object gcov structures.  */
-static struct gcov_info *gcov_list;
-
-/* Size of the longest file name. */
-static size_t gcov_max_filename = 0;
-
-/* Flag when the profile has already been dumped via __gcov_dump().  */
-int gcov_dump_complete = 0;
-
-/* Make sure path component of the given FILENAME exists, create
-   missing directories. FILENAME must be writable.
-   Returns zero on success, or -1 if an error occurred.  */
-
-static int
-create_file_directory (char *filename)
-{
-#if !defined(TARGET_POSIX_IO) && !defined(_WIN32)
-  (void) filename;
-  return -1;
-#else
-  char *s;
-
-  s = filename;
-
-  if (HAS_DRIVE_SPEC(s))
-    s += 2;
-  if (IS_DIR_SEPARATOR(*s))
-    ++s;
-  for (; *s != '\0'; s++)
-    if (IS_DIR_SEPARATOR(*s))
-      {
-        char sep = *s;
-	*s  = '\0';
-
-        /* Try to make directory if it doesn't already exist.  */
-        if (access (filename, F_OK) == -1
-#ifdef TARGET_POSIX_IO
-            && mkdir (filename, 0755) == -1
-#else
-            && mkdir (filename) == -1
-#endif
-            /* The directory might have been made by another process.  */
-	    && errno != EEXIST)
-	  {
-            fprintf (stderr, "profiling:%s:Cannot create directory\n",
-		     filename);
-            *s = sep;
-	    return -1;
-	  };
-
-	*s = sep;
-      };
-  return 0;
-#endif
-}
-
-static struct gcov_fn_buffer *
-free_fn_data (const struct gcov_info *gi_ptr, struct gcov_fn_buffer *buffer,
-	      unsigned limit)
-{
-  struct gcov_fn_buffer *next;
-  unsigned ix, n_ctr = 0;
-  
-  if (!buffer)
-    return 0;
-  next = buffer->next;
-
-  for (ix = 0; ix != limit; ix++)
-    if (gi_ptr->merge[ix])
-      free (buffer->info.ctrs[n_ctr++].values);
-  free (buffer);
-  return next;
-}
-  
-static struct gcov_fn_buffer **
-buffer_fn_data (const char *filename, const struct gcov_info *gi_ptr,
-		struct gcov_fn_buffer **end_ptr, unsigned fn_ix)
-{
-  unsigned n_ctrs = 0, ix = 0;
-  struct gcov_fn_buffer *fn_buffer;
-  unsigned len;
-
-  for (ix = GCOV_COUNTERS; ix--;)
-    if (gi_ptr->merge[ix])
-      n_ctrs++;
-
-  len = sizeof (*fn_buffer) + sizeof (fn_buffer->info.ctrs[0]) * n_ctrs;
-  fn_buffer = (struct gcov_fn_buffer *)malloc (len);
-
-  if (!fn_buffer)
-    goto fail;
-  
-  fn_buffer->next = 0;
-  fn_buffer->fn_ix = fn_ix;
-  fn_buffer->info.ident = gcov_read_unsigned ();
-  fn_buffer->info.lineno_checksum = gcov_read_unsigned ();
-  fn_buffer->info.cfg_checksum = gcov_read_unsigned ();
-
-  for (n_ctrs = ix = 0; ix != GCOV_COUNTERS; ix++)
-    {
-      gcov_unsigned_t length;
-      gcov_type *values;
-
-      if (!gi_ptr->merge[ix])
-	continue;
-      
-      if (gcov_read_unsigned () != GCOV_TAG_FOR_COUNTER (ix))
-	{
-	  len = 0;
-	  goto fail;
-	}
-
-      length = GCOV_TAG_COUNTER_NUM (gcov_read_unsigned ());
-      len = length * sizeof (gcov_type);
-      values = (gcov_type *)malloc (len);
-      if (!values)
-	goto fail;
-      
-      fn_buffer->info.ctrs[n_ctrs].num = length;
-      fn_buffer->info.ctrs[n_ctrs].values = values;
-
-      while (length--)
-	*values++ = gcov_read_counter ();
-      n_ctrs++;
-    }
-  
-  *end_ptr = fn_buffer;
-  return &fn_buffer->next;
-
- fail:
-  fprintf (stderr, "profiling:%s:Function %u %s %u \n", filename, fn_ix,
-	   len ? "cannot allocate" : "counter mismatch", len ? len : ix);
-
-  return (struct gcov_fn_buffer **)free_fn_data (gi_ptr, fn_buffer, ix);
-}
-
-/* Add an unsigned value to the current crc */
-
-static gcov_unsigned_t
-crc32_unsigned (gcov_unsigned_t crc32, gcov_unsigned_t value)
-{
-  unsigned ix;
-
-  for (ix = 32; ix--; value <<= 1)
-    {
-      unsigned feedback;
-
-      feedback = (value ^ crc32) & 0x80000000 ? 0x04c11db7 : 0;
-      crc32 <<= 1;
-      crc32 ^= feedback;
-    }
-
-  return crc32;
-}
-
-/* Check if VERSION of the info block PTR matches libgcov one.
-   Return 1 on success, or zero in case of versions mismatch.
-   If FILENAME is not NULL, its value used for reporting purposes
-   instead of value from the info block.  */
-
-static int
-gcov_version (struct gcov_info *ptr, gcov_unsigned_t version,
-	      const char *filename)
-{
-  if (version != GCOV_VERSION)
-    {
-      char v[4], e[4];
-
-      GCOV_UNSIGNED2STRING (v, version);
-      GCOV_UNSIGNED2STRING (e, GCOV_VERSION);
-
-      fprintf (stderr,
-	       "profiling:%s:Version mismatch - expected %.4s got %.4s\n",
-	       filename? filename : ptr->filename, e, v);
-      return 0;
-    }
-  return 1;
-}
-
-/* Insert counter VALUE into HISTOGRAM.  */
-
-static void
-gcov_histogram_insert(gcov_bucket_type *histogram, gcov_type value)
-{
-  unsigned i;
-
-  i = gcov_histo_index(value);
-  histogram[i].num_counters++;
-  histogram[i].cum_value += value;
-  if (value < histogram[i].min_value)
-    histogram[i].min_value = value;
-}
-
-/* Computes a histogram of the arc counters to place in the summary SUM.  */
-
-static void
-gcov_compute_histogram (struct gcov_summary *sum)
-{
-  struct gcov_info *gi_ptr;
-  const struct gcov_fn_info *gfi_ptr;
-  const struct gcov_ctr_info *ci_ptr;
-  struct gcov_ctr_summary *cs_ptr;
-  unsigned t_ix, f_ix, ctr_info_ix, ix;
-  int h_ix;
-
-  /* This currently only applies to arc counters.  */
-  t_ix = GCOV_COUNTER_ARCS;
-
-  /* First check if there are any counts recorded for this counter.  */
-  cs_ptr = &(sum->ctrs[t_ix]);
-  if (!cs_ptr->num)
-    return;
-
-  for (h_ix = 0; h_ix < GCOV_HISTOGRAM_SIZE; h_ix++)
-    {
-      cs_ptr->histogram[h_ix].num_counters = 0;
-      cs_ptr->histogram[h_ix].min_value = cs_ptr->run_max;
-      cs_ptr->histogram[h_ix].cum_value = 0;
-    }
-
-  /* Walk through all the per-object structures and record each of
-     the count values in histogram.  */
-  for (gi_ptr = gcov_list; gi_ptr; gi_ptr = gi_ptr->next)
-    {
-      if (!gi_ptr->merge[t_ix])
-        continue;
-
-      /* Find the appropriate index into the gcov_ctr_info array
-         for the counter we are currently working on based on the
-         existence of the merge function pointer for this object.  */
-      for (ix = 0, ctr_info_ix = 0; ix < t_ix; ix++)
-        {
-          if (gi_ptr->merge[ix])
-            ctr_info_ix++;
-        }
-      for (f_ix = 0; f_ix != gi_ptr->n_functions; f_ix++)
-        {
-          gfi_ptr = gi_ptr->functions[f_ix];
-
-          if (!gfi_ptr || gfi_ptr->key != gi_ptr)
-            continue;
-
-          ci_ptr = &gfi_ptr->ctrs[ctr_info_ix];
-          for (ix = 0; ix < ci_ptr->num; ix++)
-            gcov_histogram_insert (cs_ptr->histogram, ci_ptr->values[ix]);
-        }
-    }
-}
-
-/* Dump the coverage counts. We merge with existing counts when
-   possible, to avoid growing the .da files ad infinitum. We use this
-   program's checksum to make sure we only accumulate whole program
-   statistics to the correct summary. An object file might be embedded
-   in two separate programs, and we must keep the two program
-   summaries separate.  */
-
-void
-gcov_exit (void)
-{
-  struct gcov_info *gi_ptr;
-  const struct gcov_fn_info *gfi_ptr;
-  struct gcov_summary this_prg; /* summary for program.  */
-#if !GCOV_LOCKED
-  struct gcov_summary all_prg;  /* summary for all instances of program.  */
-#endif
-  struct gcov_ctr_summary *cs_ptr;
-  const struct gcov_ctr_info *ci_ptr;
-  unsigned t_ix;
-  int f_ix;
-  gcov_unsigned_t c_num;
-  const char *gcov_prefix;
-  int gcov_prefix_strip = 0;
-  size_t prefix_length;
-  char *gi_filename, *gi_filename_up;
-  gcov_unsigned_t crc32 = 0;
-
-  /* Prevent the counters from being dumped a second time on exit when the
-     application already wrote out the profile using __gcov_dump().  */
-  if (gcov_dump_complete)
-    return;
-
-#if !GCOV_LOCKED
-  memset (&all_prg, 0, sizeof (all_prg));
-#endif
-  /* Find the totals for this execution.  */
-  memset (&this_prg, 0, sizeof (this_prg));
-  for (gi_ptr = gcov_list; gi_ptr; gi_ptr = gi_ptr->next)
-    {
-      crc32 = crc32_unsigned (crc32, gi_ptr->stamp);
-      crc32 = crc32_unsigned (crc32, gi_ptr->n_functions);
-      
-      for (f_ix = 0; (unsigned)f_ix != gi_ptr->n_functions; f_ix++)
-	{
-	  gfi_ptr = gi_ptr->functions[f_ix];
-
-	  if (gfi_ptr && gfi_ptr->key != gi_ptr)
-	    gfi_ptr = 0;
-	  
-	  crc32 = crc32_unsigned (crc32, gfi_ptr ? gfi_ptr->cfg_checksum : 0);
-	  crc32 = crc32_unsigned (crc32,
-				  gfi_ptr ? gfi_ptr->lineno_checksum : 0);
-	  if (!gfi_ptr)
-	    continue;
-
-	  ci_ptr = gfi_ptr->ctrs;
-	  for (t_ix = 0; t_ix != GCOV_COUNTERS_SUMMABLE; t_ix++)
-	    {
-	      if (!gi_ptr->merge[t_ix])
-		continue;
-
-	      cs_ptr = &this_prg.ctrs[t_ix];
-	      cs_ptr->num += ci_ptr->num;
-	      crc32 = crc32_unsigned (crc32, ci_ptr->num);
-	      
-	      for (c_num = 0; c_num < ci_ptr->num; c_num++)
-		{
-		  cs_ptr->sum_all += ci_ptr->values[c_num];
-		  if (cs_ptr->run_max < ci_ptr->values[c_num])
-		    cs_ptr->run_max = ci_ptr->values[c_num];
-		}
-	      ci_ptr++;
-	    }
-	}
-    }
-  gcov_compute_histogram (&this_prg);
-
-  {
-    /* Check if the level of dirs to strip off specified. */
-    char *tmp = getenv("GCOV_PREFIX_STRIP");
-    if (tmp)
-      {
-	gcov_prefix_strip = atoi (tmp);
-	/* Do not consider negative values. */
-	if (gcov_prefix_strip < 0)
-	  gcov_prefix_strip = 0;
-      }
-  }
-
-  /* Get file name relocation prefix.  Non-absolute values are ignored. */
-  gcov_prefix = getenv("GCOV_PREFIX");
-  if (gcov_prefix)
-    {
-      prefix_length = strlen(gcov_prefix);
-
-      /* Remove an unnecessary trailing '/' */
-      if (IS_DIR_SEPARATOR (gcov_prefix[prefix_length - 1]))
-	prefix_length--;
-    }
-  else
-    prefix_length = 0;
-
-  /* If no prefix was specified and a prefix stip, then we assume
-     relative.  */
-  if (gcov_prefix_strip != 0 && prefix_length == 0)
-    {
-      gcov_prefix = ".";
-      prefix_length = 1;
-    }
-  /* Allocate and initialize the filename scratch space plus one.  */
-  gi_filename = (char *) alloca (prefix_length + gcov_max_filename + 2);
-  if (prefix_length)
-    memcpy (gi_filename, gcov_prefix, prefix_length);
-  gi_filename_up = gi_filename + prefix_length;
-
-  /* Now merge each file.  */
-  for (gi_ptr = gcov_list; gi_ptr; gi_ptr = gi_ptr->next)
-    {
-      unsigned n_counts;
-      struct gcov_summary prg; /* summary for this object over all
-				  program.  */
-      struct gcov_ctr_summary *cs_prg, *cs_tprg;
-#if !GCOV_LOCKED
-      struct gcov_ctr_summary *cs_all;
-#endif
-      int error = 0;
-      gcov_unsigned_t tag, length;
-      gcov_position_t summary_pos = 0;
-      gcov_position_t eof_pos = 0;
-      const char *fname, *s;
-      struct gcov_fn_buffer *fn_buffer = 0;
-      struct gcov_fn_buffer **fn_tail = &fn_buffer;
-      struct gcov_summary_buffer *next_sum_buffer, *sum_buffer = 0;
-      struct gcov_summary_buffer **sum_tail = &sum_buffer;
-
-      fname = gi_ptr->filename;
-
-      /* Avoid to add multiple drive letters into combined path.  */
-      if (prefix_length != 0 && HAS_DRIVE_SPEC(fname))
-        fname += 2;
-
-      /* Build relocated filename, stripping off leading
-         directories from the initial filename if requested. */
-      if (gcov_prefix_strip > 0)
-        {
-          int level = 0;
-          s = fname;
-          if (IS_DIR_SEPARATOR(*s))
-            ++s;
-
-          /* Skip selected directory levels. */
-	  for (; (*s != '\0') && (level < gcov_prefix_strip); s++)
-	    if (IS_DIR_SEPARATOR(*s))
-	      {
-		fname = s;
-		level++;
-	      }
-        }
-
-      /* Update complete filename with stripped original. */
-      if (prefix_length != 0 && !IS_DIR_SEPARATOR (*fname))
-        {
-          /* If prefix is given, add directory separator.  */
-	  strcpy (gi_filename_up, "/");
-	  strcpy (gi_filename_up + 1, fname);
-	}
-      else
-        strcpy (gi_filename_up, fname);
-
-      if (!gcov_open (gi_filename))
-	{
-	  /* Open failed likely due to missed directory.
-	     Create directory and retry to open file. */
-          if (create_file_directory (gi_filename))
-	    {
-	      fprintf (stderr, "profiling:%s:Skip\n", gi_filename);
-	      continue;
-	    }
-	  if (!gcov_open (gi_filename))
-	    {
-              fprintf (stderr, "profiling:%s:Cannot open\n", gi_filename);
-	      continue;
-	    }
-	}
-
-      tag = gcov_read_unsigned ();
-      if (tag)
-	{
-	  /* Merge data from file.  */
-	  if (tag != GCOV_DATA_MAGIC)
-	    {
-	      fprintf (stderr, "profiling:%s:Not a gcov data file\n",
-		       gi_filename);
-	      goto read_fatal;
-	    }
-	  length = gcov_read_unsigned ();
-	  if (!gcov_version (gi_ptr, length, gi_filename))
-	    goto read_fatal;
-
-	  length = gcov_read_unsigned ();
-	  if (length != gi_ptr->stamp)
-	    /* Read from a different compilation. Overwrite the file.  */
-	    goto rewrite;
-
-	  /* Look for program summary.  */
-	  for (f_ix = 0;;)
-	    {
-	      struct gcov_summary tmp;
-	      
-	      eof_pos = gcov_position ();
-	      tag = gcov_read_unsigned ();
-	      if (tag != GCOV_TAG_PROGRAM_SUMMARY)
-		break;
-
-	      f_ix--;
-	      length = gcov_read_unsigned ();
-	      gcov_read_summary (&tmp);
-	      if ((error = gcov_is_error ()))
-		goto read_error;
-	      if (summary_pos)
-                {
-                  /* Save all summaries after the one that will be
-                     merged into below. These will need to be rewritten
-                     as histogram merging may change the number of non-zero
-                     histogram entries that will be emitted, and thus the
-                     size of the merged summary.  */
-                  (*sum_tail) = (struct gcov_summary_buffer *)
-                      malloc (sizeof(struct gcov_summary_buffer));
-                  (*sum_tail)->summary = tmp;
-                  (*sum_tail)->next = 0;
-                  sum_tail = &((*sum_tail)->next);
-                  goto next_summary;
-                }
-	      if (tmp.checksum != crc32)
-                goto next_summary;
-	      
-	      for (t_ix = 0; t_ix != GCOV_COUNTERS_SUMMABLE; t_ix++)
-		if (tmp.ctrs[t_ix].num != this_prg.ctrs[t_ix].num)
-                  goto next_summary;
-	      prg = tmp;
-	      summary_pos = eof_pos;
-
-	    next_summary:;
-	    }
-	  
-	  /* Merge execution counts for each function.  */
-	  for (f_ix = 0; (unsigned)f_ix != gi_ptr->n_functions;
-	       f_ix++, tag = gcov_read_unsigned ())
-	    {
-	      gfi_ptr = gi_ptr->functions[f_ix];
-
-	      if (tag != GCOV_TAG_FUNCTION)
-		goto read_mismatch;
-
-	      length = gcov_read_unsigned ();
-	      if (!length)
-		/* This function did not appear in the other program.
-		   We have nothing to merge.  */
-		continue;
-
-	      if (length != GCOV_TAG_FUNCTION_LENGTH)
-		goto read_mismatch;
-	      
-	      if (!gfi_ptr || gfi_ptr->key != gi_ptr)
-		{
-		  /* This function appears in the other program.  We
-		     need to buffer the information in order to write
-		     it back out -- we'll be inserting data before
-		     this point, so cannot simply keep the data in the
-		     file.  */
-		  fn_tail = buffer_fn_data (gi_filename,
-					    gi_ptr, fn_tail, f_ix);
-		  if (!fn_tail)
-		    goto read_mismatch;
-		  continue;
-		}
-
-	      length = gcov_read_unsigned ();
-	      if (length != gfi_ptr->ident)
-		goto read_mismatch;
-	      
-	      length = gcov_read_unsigned ();
-	      if (length != gfi_ptr->lineno_checksum)
-		goto read_mismatch;
-	      
-	      length = gcov_read_unsigned ();
-	      if (length != gfi_ptr->cfg_checksum)
-		goto read_mismatch;
-	      
-	      ci_ptr = gfi_ptr->ctrs;
-	      for (t_ix = 0; t_ix < GCOV_COUNTERS; t_ix++)
-		{
-		  gcov_merge_fn merge = gi_ptr->merge[t_ix];
-
-		  if (!merge)
-		    continue;
-
-		  tag = gcov_read_unsigned ();
-		  length = gcov_read_unsigned ();
-		  if (tag != GCOV_TAG_FOR_COUNTER (t_ix)
-		      || length != GCOV_TAG_COUNTER_LENGTH (ci_ptr->num))
-		    goto read_mismatch;
-		  (*merge) (ci_ptr->values, ci_ptr->num);
-		  ci_ptr++;
-		}
-	      if ((error = gcov_is_error ()))
-		goto read_error;
-	    }
-
-	  if (tag)
-	    {
-	    read_mismatch:;
-	      fprintf (stderr, "profiling:%s:Merge mismatch for %s %u\n",
-		       gi_filename, f_ix >= 0 ? "function" : "summary",
-		       f_ix < 0 ? -1 - f_ix : f_ix);
-	      goto read_fatal;
-	    }
-	}
-      goto rewrite;
-
-    read_error:;
-      fprintf (stderr, "profiling:%s:%s merging\n", gi_filename,
-	       error < 0 ? "Overflow": "Error");
-
-      goto read_fatal;
-
-    rewrite:;
-      gcov_rewrite ();
-      if (!summary_pos)
-	{
-	  memset (&prg, 0, sizeof (prg));
-	  summary_pos = eof_pos;
-	}
-
-      /* Merge the summaries.  */
-      for (t_ix = 0; t_ix < GCOV_COUNTERS_SUMMABLE; t_ix++)
-	{
-	  cs_prg = &prg.ctrs[t_ix];
-	  cs_tprg = &this_prg.ctrs[t_ix];
-
-	  if (gi_ptr->merge[t_ix])
-	    {
-	      if (!cs_prg->runs++)
-	        cs_prg->num = cs_tprg->num;
-	      cs_prg->sum_all += cs_tprg->sum_all;
-	      if (cs_prg->run_max < cs_tprg->run_max)
-		cs_prg->run_max = cs_tprg->run_max;
-	      cs_prg->sum_max += cs_tprg->run_max;
-              if (cs_prg->runs == 1)
-                memcpy (cs_prg->histogram, cs_tprg->histogram,
-                        sizeof (gcov_bucket_type) * GCOV_HISTOGRAM_SIZE);
-              else
-                gcov_histogram_merge (cs_prg->histogram, cs_tprg->histogram);
-	    }
-	  else if (cs_prg->runs)
-	    goto read_mismatch;
-
-#if !GCOV_LOCKED
-	  cs_all = &all_prg.ctrs[t_ix];
-	  if (!cs_all->runs && cs_prg->runs)
-            {
-              cs_all->num = cs_prg->num;
-              cs_all->runs = cs_prg->runs;
-              cs_all->sum_all = cs_prg->sum_all;
-              cs_all->run_max = cs_prg->run_max;
-              cs_all->sum_max = cs_prg->sum_max;
-            }
-	  else if (!all_prg.checksum
-                   /* Don't compare the histograms, which may have slight
-                      variations depending on the order they were updated
-                      due to the truncating integer divides used in the
-                      merge.  */
-                   && (cs_all->num != cs_prg->num
-                       || cs_all->runs != cs_prg->runs
-                       || cs_all->sum_all != cs_prg->sum_all
-                       || cs_all->run_max != cs_prg->run_max
-                       || cs_all->sum_max != cs_prg->sum_max))
-	    {
-	      fprintf (stderr,
-                       "profiling:%s:Data file mismatch - some data files may "
-                       "have been concurrently updated without locking support\n",
-		       gi_filename);
-	      all_prg.checksum = ~0u;
-	    }
-#endif
-	}
-
-      prg.checksum = crc32;
-
-      /* Write out the data.  */
-      if (!eof_pos)
-	{
-	  gcov_write_tag_length (GCOV_DATA_MAGIC, GCOV_VERSION);
-	  gcov_write_unsigned (gi_ptr->stamp);
-	}
-
-      if (summary_pos)
-	gcov_seek (summary_pos);
-
-      /* Generate whole program statistics.  */
-      gcov_write_summary (GCOV_TAG_PROGRAM_SUMMARY, &prg);
-
-      /* Rewrite all the summaries that were after the summary we merged
-         into. This is necessary as the merged summary may have a different
-         size due to the number of non-zero histogram entries changing after
-         merging.  */
-      
-      while (sum_buffer)
-        {
-          gcov_write_summary (GCOV_TAG_PROGRAM_SUMMARY, &sum_buffer->summary);
-          next_sum_buffer = sum_buffer->next;
-          free (sum_buffer);
-          sum_buffer = next_sum_buffer;
-        }
-
-      /* Write execution counts for each function.  */
-      for (f_ix = 0; (unsigned)f_ix != gi_ptr->n_functions; f_ix++)
-	{
-	  unsigned buffered = 0;
-
-	  if (fn_buffer && fn_buffer->fn_ix == (unsigned)f_ix)
-	    {
-	      /* Buffered data from another program.  */
-	      buffered = 1;
-	      gfi_ptr = &fn_buffer->info;
-	      length = GCOV_TAG_FUNCTION_LENGTH;
-	    }
-	  else
-	    {
-	      gfi_ptr = gi_ptr->functions[f_ix];
-	      if (gfi_ptr && gfi_ptr->key == gi_ptr)
-		length = GCOV_TAG_FUNCTION_LENGTH;
-	      else
-		length = 0;
-	    }
-	  
-	  gcov_write_tag_length (GCOV_TAG_FUNCTION, length);
-	  if (!length)
-	    continue;
-	  
-	  gcov_write_unsigned (gfi_ptr->ident);
-	  gcov_write_unsigned (gfi_ptr->lineno_checksum);
-	  gcov_write_unsigned (gfi_ptr->cfg_checksum);
-
-	  ci_ptr = gfi_ptr->ctrs;
-	  for (t_ix = 0; t_ix < GCOV_COUNTERS; t_ix++)
-	    {
-	      if (!gi_ptr->merge[t_ix])
-		continue;
-
-	      n_counts = ci_ptr->num;
-	      gcov_write_tag_length (GCOV_TAG_FOR_COUNTER (t_ix),
-				     GCOV_TAG_COUNTER_LENGTH (n_counts));
-	      gcov_type *c_ptr = ci_ptr->values;
-	      while (n_counts--)
-		gcov_write_counter (*c_ptr++);
-	      ci_ptr++;
-	    }
-	  if (buffered)
-	    fn_buffer = free_fn_data (gi_ptr, fn_buffer, GCOV_COUNTERS);
-	}
-
-      gcov_write_unsigned (0);
-
-    read_fatal:;
-      while (fn_buffer)
-	fn_buffer = free_fn_data (gi_ptr, fn_buffer, GCOV_COUNTERS);
-
-      if ((error = gcov_close ()))
-	  fprintf (stderr, error  < 0 ?
-		   "profiling:%s:Overflow writing\n" :
-		   "profiling:%s:Error writing\n",
-		   gi_filename);
-    }
-}
-
-/* Reset all counters to zero.  */
-
-void
-gcov_clear (void)
-{
-  const struct gcov_info *gi_ptr;
-
-  for (gi_ptr = gcov_list; gi_ptr; gi_ptr = gi_ptr->next)
-    {
-      unsigned f_ix;
-
-      for (f_ix = 0; f_ix < gi_ptr->n_functions; f_ix++)
-	{
-	  unsigned t_ix;
-	  const struct gcov_fn_info *gfi_ptr = gi_ptr->functions[f_ix];
-
-	  if (!gfi_ptr || gfi_ptr->key != gi_ptr)
-	    continue;
-	  const struct gcov_ctr_info *ci_ptr = gfi_ptr->ctrs;
-	  for (t_ix = 0; t_ix != GCOV_COUNTERS; t_ix++)
-	    {
-	      if (!gi_ptr->merge[t_ix])
-		continue;
-	      
-	      memset (ci_ptr->values, 0, sizeof (gcov_type) * ci_ptr->num);
-	      ci_ptr++;
-	    }
-	}
-    }
-}
-
-/* Add a new object file onto the bb chain.  Invoked automatically
-   when running an object file's global ctors.  */
-
-void
-__gcov_init (struct gcov_info *info)
-{
-  if (!info->version || !info->n_functions)
-    return;
-  if (gcov_version (info, info->version, 0))
-    {
-      size_t filename_length = strlen(info->filename);
-
-      /* Refresh the longest file name information */
-      if (filename_length > gcov_max_filename)
-        gcov_max_filename = filename_length;
-
-      if (!gcov_list)
-	atexit (gcov_exit);
-
-      info->next = gcov_list;
-      gcov_list = info;
-    }
-  info->version = 0;
-}
-
-#ifdef __GTHREAD_MUTEX_INIT
-ATTRIBUTE_HIDDEN __gthread_mutex_t __gcov_flush_mx = __GTHREAD_MUTEX_INIT;
-#define init_mx_once()
-#else
-__gthread_mutex_t __gcov_flush_mx ATTRIBUTE_HIDDEN;
-
-static void
-init_mx (void)
-{
-  __GTHREAD_MUTEX_INIT_FUNCTION (&__gcov_flush_mx);
-}
-static void
-init_mx_once (void)
-{
-  static __gthread_once_t once = __GTHREAD_ONCE_INIT;
-  __gthread_once (&once, init_mx);
-}
-#endif
-
-/* Called before fork or exec - write out profile information gathered so
-   far and reset it to zero.  This avoids duplication or loss of the
-   profile information gathered so far.  */
-
-void
-__gcov_flush (void)
-{
-  init_mx_once ();
-  __gthread_mutex_lock (&__gcov_flush_mx);
-
-  gcov_exit ();
-  gcov_clear ();
-
-  __gthread_mutex_unlock (&__gcov_flush_mx);
-}
-
-#endif /* L_gcov */
-
-#ifdef L_gcov_reset
-
-/* Function that can be called from application to reset counters to zero,
-   in order to collect profile in region of interest.  */
-
-void
-__gcov_reset (void)
-{
-  gcov_clear ();
-  /* Re-enable dumping to support collecting profile in multiple regions
-     of interest.  */
-  gcov_dump_complete = 0;
-}
-
-#endif /* L_gcov_reset */
-
-#ifdef L_gcov_dump
-
-/* Function that can be called from application to write profile collected
-   so far, in order to collect profile in region of interest.  */
-
-void
-__gcov_dump (void)
-{
-  gcov_exit ();
-  /* Prevent profile from being dumped a second time on application exit.  */
-  gcov_dump_complete = 1;
-}
-
-#endif /* L_gcov_dump */
-
-#ifdef L_gcov_merge_add
-/* The profile merging function that just adds the counters.  It is given
-   an array COUNTERS of N_COUNTERS old counters and it reads the same number
-   of counters from the gcov file.  */
-void
-__gcov_merge_add (gcov_type *counters, unsigned n_counters)
-{
-  for (; n_counters; counters++, n_counters--)
-    *counters += gcov_read_counter ();
-}
-#endif /* L_gcov_merge_add */
-
-#ifdef L_gcov_merge_ior
-/* The profile merging function that just adds the counters.  It is given
-   an array COUNTERS of N_COUNTERS old counters and it reads the same number
-   of counters from the gcov file.  */
-void
-__gcov_merge_ior (gcov_type *counters, unsigned n_counters)
-{
-  for (; n_counters; counters++, n_counters--)
-    *counters |= gcov_read_counter ();
-}
-#endif
-
-#ifdef L_gcov_merge_single
-/* The profile merging function for choosing the most common value.
-   It is given an array COUNTERS of N_COUNTERS old counters and it
-   reads the same number of counters from the gcov file.  The counters
-   are split into 3-tuples where the members of the tuple have
-   meanings:
-
-   -- the stored candidate on the most common value of the measured entity
-   -- counter
-   -- total number of evaluations of the value  */
-void
-__gcov_merge_single (gcov_type *counters, unsigned n_counters)
-{
-  unsigned i, n_measures;
-  gcov_type value, counter, all;
-
-  gcc_assert (!(n_counters % 3));
-  n_measures = n_counters / 3;
-  for (i = 0; i < n_measures; i++, counters += 3)
-    {
-      value = gcov_read_counter ();
-      counter = gcov_read_counter ();
-      all = gcov_read_counter ();
-
-      if (counters[0] == value)
-	counters[1] += counter;
-      else if (counter > counters[1])
-	{
-	  counters[0] = value;
-	  counters[1] = counter - counters[1];
-	}
-      else
-	counters[1] -= counter;
-      counters[2] += all;
-    }
-}
-#endif /* L_gcov_merge_single */
-
-#ifdef L_gcov_merge_delta
-/* The profile merging function for choosing the most common
-   difference between two consecutive evaluations of the value.  It is
-   given an array COUNTERS of N_COUNTERS old counters and it reads the
-   same number of counters from the gcov file.  The counters are split
-   into 4-tuples where the members of the tuple have meanings:
-
-   -- the last value of the measured entity
-   -- the stored candidate on the most common difference
-   -- counter
-   -- total number of evaluations of the value  */
-void
-__gcov_merge_delta (gcov_type *counters, unsigned n_counters)
-{
-  unsigned i, n_measures;
-  gcov_type value, counter, all;
-
-  gcc_assert (!(n_counters % 4));
-  n_measures = n_counters / 4;
-  for (i = 0; i < n_measures; i++, counters += 4)
-    {
-      /* last = */ gcov_read_counter ();
-      value = gcov_read_counter ();
-      counter = gcov_read_counter ();
-      all = gcov_read_counter ();
-
-      if (counters[1] == value)
-	counters[2] += counter;
-      else if (counter > counters[2])
-	{
-	  counters[1] = value;
-	  counters[2] = counter - counters[2];
-	}
-      else
-	counters[2] -= counter;
-      counters[3] += all;
-    }
-}
-#endif /* L_gcov_merge_delta */
-
-#ifdef L_gcov_interval_profiler
-/* If VALUE is in interval <START, START + STEPS - 1>, then increases the
-   corresponding counter in COUNTERS.  If the VALUE is above or below
-   the interval, COUNTERS[STEPS] or COUNTERS[STEPS + 1] is increased
-   instead.  */
-
-void
-__gcov_interval_profiler (gcov_type *counters, gcov_type value,
-			  int start, unsigned steps)
-{
-  gcov_type delta = value - start;
-  if (delta < 0)
-    counters[steps + 1]++;
-  else if (delta >= steps)
-    counters[steps]++;
-  else
-    counters[delta]++;
-}
-#endif
-
-#ifdef L_gcov_pow2_profiler
-/* If VALUE is a power of two, COUNTERS[1] is incremented.  Otherwise
-   COUNTERS[0] is incremented.  */
-
-void
-__gcov_pow2_profiler (gcov_type *counters, gcov_type value)
-{
-  if (value & (value - 1))
-    counters[0]++;
-  else
-    counters[1]++;
-}
-#endif
-
-/* Tries to determine the most common value among its inputs.  Checks if the
-   value stored in COUNTERS[0] matches VALUE.  If this is the case, COUNTERS[1]
-   is incremented.  If this is not the case and COUNTERS[1] is not zero,
-   COUNTERS[1] is decremented.  Otherwise COUNTERS[1] is set to one and
-   VALUE is stored to COUNTERS[0].  This algorithm guarantees that if this
-   function is called more than 50% of the time with one value, this value
-   will be in COUNTERS[0] in the end.
-
-   In any case, COUNTERS[2] is incremented.  */
-
-static inline void
-__gcov_one_value_profiler_body (gcov_type *counters, gcov_type value)
-{
-  if (value == counters[0])
-    counters[1]++;
-  else if (counters[1] == 0)
-    {
-      counters[1] = 1;
-      counters[0] = value;
-    }
-  else
-    counters[1]--;
-  counters[2]++;
-}
-
-#ifdef L_gcov_one_value_profiler
-void
-__gcov_one_value_profiler (gcov_type *counters, gcov_type value)
-{
-  __gcov_one_value_profiler_body (counters, value);
-}
-#endif
-
-#ifdef L_gcov_indirect_call_profiler
-/* This function exist only for workaround of binutils bug 14342.
-   Once this compatibility hack is obsolette, it can be removed.  */
-
-/* By default, the C++ compiler will use function addresses in the
-   vtable entries.  Setting TARGET_VTABLE_USES_DESCRIPTORS to nonzero
-   tells the compiler to use function descriptors instead.  The value
-   of this macro says how many words wide the descriptor is (normally 2),
-   but it may be dependent on target flags.  Since we do not have access
-   to the target flags here we just check to see if it is set and use
-   that to set VTABLE_USES_DESCRIPTORS to 0 or 1.
-
-   It is assumed that the address of a function descriptor may be treated
-   as a pointer to a function.  */
-
-#ifdef TARGET_VTABLE_USES_DESCRIPTORS
-#define VTABLE_USES_DESCRIPTORS 1
-#else
-#define VTABLE_USES_DESCRIPTORS 0
-#endif
-
-/* Tries to determine the most common value among its inputs. */
-void
-__gcov_indirect_call_profiler (gcov_type* counter, gcov_type value,
-                               void* cur_func, void* callee_func)
-{
-  /* If the C++ virtual tables contain function descriptors then one
-     function may have multiple descriptors and we need to dereference
-     the descriptors to see if they point to the same function.  */
-  if (cur_func == callee_func
-      || (VTABLE_USES_DESCRIPTORS && callee_func
-          && *(void **) cur_func == *(void **) callee_func))
-    __gcov_one_value_profiler_body (counter, value);
-}
-
-#endif
-#ifdef L_gcov_indirect_call_profiler_v2
-
-/* These two variables are used to actually track caller and callee.  Keep
-   them in TLS memory so races are not common (they are written to often).
-   The variables are set directly by GCC instrumented code, so declaration
-   here must match one in tree-profile.c  */
-
-#if defined(HAVE_CC_TLS) && !defined (USE_EMUTLS)
-__thread 
-#endif
-void * __gcov_indirect_call_callee;
-#if defined(HAVE_CC_TLS) && !defined (USE_EMUTLS) 
-__thread 
-#endif
-gcov_type * __gcov_indirect_call_counters;
-
-/* By default, the C++ compiler will use function addresses in the
-   vtable entries.  Setting TARGET_VTABLE_USES_DESCRIPTORS to nonzero
-   tells the compiler to use function descriptors instead.  The value
-   of this macro says how many words wide the descriptor is (normally 2),
-   but it may be dependent on target flags.  Since we do not have access
-   to the target flags here we just check to see if it is set and use
-   that to set VTABLE_USES_DESCRIPTORS to 0 or 1.
-
-   It is assumed that the address of a function descriptor may be treated
-   as a pointer to a function.  */
-
-#ifdef TARGET_VTABLE_USES_DESCRIPTORS
-#define VTABLE_USES_DESCRIPTORS 1
-#else
-#define VTABLE_USES_DESCRIPTORS 0
-#endif
-
-/* Tries to determine the most common value among its inputs. */
-void
-__gcov_indirect_call_profiler_v2 (gcov_type value, void* cur_func)
-{
-  /* If the C++ virtual tables contain function descriptors then one
-     function may have multiple descriptors and we need to dereference
-     the descriptors to see if they point to the same function.  */
-  if (cur_func == __gcov_indirect_call_callee
-      || (VTABLE_USES_DESCRIPTORS && __gcov_indirect_call_callee
-	  && *(void **) cur_func == *(void **) __gcov_indirect_call_callee))
-    __gcov_one_value_profiler_body (__gcov_indirect_call_counters, value);
-}
-#endif
-
-#ifdef L_gcov_average_profiler
-/* Increase corresponding COUNTER by VALUE.  FIXME: Perhaps we want
-   to saturate up.  */
-
-void
-__gcov_average_profiler (gcov_type *counters, gcov_type value)
-{
-  counters[0] += value;
-  counters[1] ++;
-}
-#endif
-
-#ifdef L_gcov_ior_profiler
-/* Bitwise-OR VALUE into COUNTER.  */
-
-void
-__gcov_ior_profiler (gcov_type *counters, gcov_type value)
-{
-  *counters |= value;
-}
-#endif
-
-#ifdef L_gcov_fork
-/* A wrapper for the fork function.  Flushes the accumulated profiling data, so
-   that they are not counted twice.  */
-
-pid_t
-__gcov_fork (void)
-{
-  pid_t pid;
-  extern __gthread_mutex_t __gcov_flush_mx;
-  __gcov_flush ();
-  pid = fork ();
-  if (pid == 0)
-    __GTHREAD_MUTEX_INIT_FUNCTION (&__gcov_flush_mx);
-  return pid;
-}
-#endif
-
-#ifdef L_gcov_execl
-/* A wrapper for the execl function.  Flushes the accumulated profiling data, so
-   that they are not lost.  */
-
-int
-__gcov_execl (const char *path, char *arg, ...)
-{
-  va_list ap, aq;
-  unsigned i, length;
-  char **args;
-
-  __gcov_flush ();
-
-  va_start (ap, arg);
-  va_copy (aq, ap);
-
-  length = 2;
-  while (va_arg (ap, char *))
-    length++;
-  va_end (ap);
-
-  args = (char **) alloca (length * sizeof (void *));
-  args[0] = arg;
-  for (i = 1; i < length; i++)
-    args[i] = va_arg (aq, char *);
-  va_end (aq);
-
-  return execv (path, args);
-}
-#endif
-
-#ifdef L_gcov_execlp
-/* A wrapper for the execlp function.  Flushes the accumulated profiling data, so
-   that they are not lost.  */
-
-int
-__gcov_execlp (const char *path, char *arg, ...)
-{
-  va_list ap, aq;
-  unsigned i, length;
-  char **args;
-
-  __gcov_flush ();
-
-  va_start (ap, arg);
-  va_copy (aq, ap);
-
-  length = 2;
-  while (va_arg (ap, char *))
-    length++;
-  va_end (ap);
-
-  args = (char **) alloca (length * sizeof (void *));
-  args[0] = arg;
-  for (i = 1; i < length; i++)
-    args[i] = va_arg (aq, char *);
-  va_end (aq);
-
-  return execvp (path, args);
-}
-#endif
-
-#ifdef L_gcov_execle
-/* A wrapper for the execle function.  Flushes the accumulated profiling data, so
-   that they are not lost.  */
-
-int
-__gcov_execle (const char *path, char *arg, ...)
-{
-  va_list ap, aq;
-  unsigned i, length;
-  char **args;
-  char **envp;
-
-  __gcov_flush ();
-
-  va_start (ap, arg);
-  va_copy (aq, ap);
-
-  length = 2;
-  while (va_arg (ap, char *))
-    length++;
-  va_end (ap);
-
-  args = (char **) alloca (length * sizeof (void *));
-  args[0] = arg;
-  for (i = 1; i < length; i++)
-    args[i] = va_arg (aq, char *);
-  envp = va_arg (aq, char **);
-  va_end (aq);
-
-  return execve (path, args, envp);
-}
-#endif
-
-#ifdef L_gcov_execv
-/* A wrapper for the execv function.  Flushes the accumulated profiling data, so
-   that they are not lost.  */
-
-int
-__gcov_execv (const char *path, char *const argv[])
-{
-  __gcov_flush ();
-  return execv (path, argv);
-}
-#endif
-
-#ifdef L_gcov_execvp
-/* A wrapper for the execvp function.  Flushes the accumulated profiling data, so
-   that they are not lost.  */
-
-int
-__gcov_execvp (const char *path, char *const argv[])
-{
-  __gcov_flush ();
-  return execvp (path, argv);
-}
-#endif
-
-#ifdef L_gcov_execve
-/* A wrapper for the execve function.  Flushes the accumulated profiling data, so
-   that they are not lost.  */
-
-int
-__gcov_execve (const char *path, char *const argv[], char *const envp[])
-{
-  __gcov_flush ();
-  return execve (path, argv, envp);
-}
-#endif
-#endif /* inhibit_libc */
Index: libgcc/libgcov-driver-system.c
===================================================================
--- libgcc/libgcov-driver-system.c	(revision 0)
+++ libgcc/libgcov-driver-system.c	(revision 0)
@@ -0,0 +1,203 @@ 
+/* Routines required for instrumenting a program.  */
+/* Compile this one with gcc.  */
+/* Copyright (C) 1989-2013 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+/* A utility function for outputing errors.  */
+
+static int
+gcov_error (const char *fmt, ...)
+{
+  int ret;
+  va_list argp;
+  va_start (argp, fmt);
+  ret = vfprintf (stderr, fmt, argp);
+  va_end (argp);
+  return ret;
+}
+
+/* Make sure path component of the given FILENAME exists, create
+   missing directories. FILENAME must be writable.
+   Returns zero on success, or -1 if an error occurred.  */
+
+static int
+create_file_directory (char *filename)
+{
+#if !defined(TARGET_POSIX_IO) && !defined(_WIN32)
+  (void) filename;
+  return -1;
+#else
+  char *s;
+
+  s = filename;
+
+  if (HAS_DRIVE_SPEC(s))
+    s += 2;
+  if (IS_DIR_SEPARATOR(*s))
+    ++s;
+  for (; *s != '\0'; s++)
+    if (IS_DIR_SEPARATOR(*s))
+      {
+        char sep = *s;
+        *s  = '\0';
+
+        /* Try to make directory if it doesn't already exist.  */
+        if (access (filename, F_OK) == -1
+#ifdef TARGET_POSIX_IO
+            && mkdir (filename, 0755) == -1
+#else
+            && mkdir (filename) == -1
+#endif
+            /* The directory might have been made by another process.  */
+            && errno != EEXIST)
+          {
+            gcov_error ("profiling:%s:Cannot create directory\n", filename);
+            *s = sep;
+            return -1;
+          };
+
+        *s = sep;
+      };
+  return 0;
+#endif
+}
+
+static void
+allocate_filename_struct (struct gcov_filename_aux *gf)
+{
+  const char *gcov_prefix;
+  int gcov_prefix_strip = 0;
+  size_t prefix_length;
+  char *gi_filename_up;
+
+  gcc_assert (gf);
+  {
+    /* Check if the level of dirs to strip off specified. */
+    char *tmp = getenv("GCOV_PREFIX_STRIP");
+    if (tmp)
+      {
+        gcov_prefix_strip = atoi (tmp);
+        /* Do not consider negative values. */
+        if (gcov_prefix_strip < 0)
+          gcov_prefix_strip = 0;
+      }
+  }
+
+  /* Get file name relocation prefix.  Non-absolute values are ignored. */
+  gcov_prefix = getenv("GCOV_PREFIX");
+  if (gcov_prefix)
+    {
+      prefix_length = strlen(gcov_prefix);
+
+      /* Remove an unnecessary trailing '/' */
+      if (IS_DIR_SEPARATOR (gcov_prefix[prefix_length - 1]))
+        prefix_length--;
+    }
+  else
+    prefix_length = 0;
+
+  /* If no prefix was specified and a prefix stip, then we assume
+     relative.  */
+  if (gcov_prefix_strip != 0 && prefix_length == 0)
+    {
+      gcov_prefix = ".";
+      prefix_length = 1;
+    }
+  /* Allocate and initialize the filename scratch space plus one.  */
+  gi_filename = (char *) malloc (prefix_length + gcov_max_filename + 2);
+  if (prefix_length)
+    memcpy (gi_filename, gcov_prefix, prefix_length);
+  gi_filename_up = gi_filename + prefix_length;
+
+  gf->gi_filename_up = gi_filename_up;
+  gf->prefix_length = prefix_length;
+  gf->gcov_prefix_strip = gcov_prefix_strip;
+}
+
+/* Open a gcda file specified by GI_FILENAME.
+   Return -1 on error.  Return 0 on success.  */
+
+static int
+gcov_exit_open_gcda_file (struct gcov_info *gi_ptr, struct gcov_filename_aux *gf)
+{
+  int gcov_prefix_strip;
+  size_t prefix_length;
+  char *gi_filename_up;
+  const char *fname, *s;
+
+  gcov_prefix_strip = gf->gcov_prefix_strip;
+  gi_filename_up = gf->gi_filename_up;
+  prefix_length = gf->prefix_length;
+  fname = gi_ptr->filename;
+
+  /* Avoid to add multiple drive letters into combined path.  */
+  if (prefix_length != 0 && HAS_DRIVE_SPEC(fname))
+    fname += 2;
+
+  /* Build relocated filename, stripping off leading
+     directories from the initial filename if requested. */
+  if (gcov_prefix_strip > 0)
+    {
+      int level = 0;
+
+      s = fname;
+      if (IS_DIR_SEPARATOR(*s))
+        ++s;
+
+      /* Skip selected directory levels. */
+      for (; (*s != '\0') && (level < gcov_prefix_strip); s++)
+        if (IS_DIR_SEPARATOR(*s))
+          {
+            fname = s;
+            level++;
+          }
+    }
+
+  /* Update complete filename with stripped original. */
+  if (prefix_length != 0 && !IS_DIR_SEPARATOR (*fname))
+    {
+      /* If prefix is given, add directory separator.  */
+      strcpy (gi_filename_up, "/");
+      strcpy (gi_filename_up + 1, fname);
+    }
+  else
+    strcpy (gi_filename_up, fname);
+
+  if (!gcov_open (gi_filename))
+    {
+      /* Open failed likely due to missed directory.
+         Create directory and retry to open file. */
+      if (create_file_directory (gi_filename))
+        {
+          fprintf (stderr, "profiling:%s:Skip\n", gi_filename);
+          return -1;
+        }
+      if (!gcov_open (gi_filename))
+        {
+          fprintf (stderr, "profiling:%s:Cannot open\n", gi_filename);
+          return -1;
+        }
+    }
+
+  return 0;
+}
Index: libgcc/libgcov-merge.c
===================================================================
--- libgcc/libgcov-merge.c	(revision 0)
+++ libgcc/libgcov-merge.c	(revision 0)
@@ -0,0 +1,161 @@ 
+/* Routines required for instrumenting a program.  */
+/* Compile this one with gcc.  */
+/* Copyright (C) 1989-2013 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+#include "tconfig.h"
+#include "tsystem.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "libgcc_tm.h"
+
+#if defined(inhibit_libc)
+#define IN_LIBGCOV (-1)
+#else
+#define IN_LIBGCOV 1
+#endif
+
+#include "gcov-io.h"
+
+#if defined(inhibit_libc)
+/* If libc and its header files are not available, provide dummy functions.  */
+
+#ifdef L_gcov_merge_add
+void __gcov_merge_add (gcov_type *counters  __attribute__ ((unused)),
+                       unsigned n_counters __attribute__ ((unused))) {}
+#endif
+
+#ifdef L_gcov_merge_single
+void __gcov_merge_single (gcov_type *counters  __attribute__ ((unused)),
+                          unsigned n_counters __attribute__ ((unused))) {}
+#endif
+
+#ifdef L_gcov_merge_delta
+void __gcov_merge_delta (gcov_type *counters  __attribute__ ((unused)),
+                         unsigned n_counters __attribute__ ((unused))) {}
+#endif
+
+#else
+
+#ifdef L_gcov_merge_add
+/* The profile merging function that just adds the counters.  It is given
+   an array COUNTERS of N_COUNTERS old counters and it reads the same number
+   of counters from the gcov file.  */
+void
+__gcov_merge_add (gcov_type *counters, unsigned n_counters)
+{
+  for (; n_counters; counters++, n_counters--)
+    *counters += gcov_read_counter ();
+}
+#endif /* L_gcov_merge_add */
+
+#ifdef L_gcov_merge_ior
+/* The profile merging function that just adds the counters.  It is given
+   an array COUNTERS of N_COUNTERS old counters and it reads the same number
+   of counters from the gcov file.  */
+void
+__gcov_merge_ior (gcov_type *counters, unsigned n_counters)
+{
+  for (; n_counters; counters++, n_counters--)
+    *counters |= gcov_read_counter ();
+}
+#endif
+
+#ifdef L_gcov_merge_single
+/* The profile merging function for choosing the most common value.
+   It is given an array COUNTERS of N_COUNTERS old counters and it
+   reads the same number of counters from the gcov file.  The counters
+   are split into 3-tuples where the members of the tuple have
+   meanings:
+
+   -- the stored candidate on the most common value of the measured entity
+   -- counter
+   -- total number of evaluations of the value  */
+void
+__gcov_merge_single (gcov_type *counters, unsigned n_counters)
+{
+  unsigned i, n_measures;
+  gcov_type value, counter, all;
+
+  gcc_assert (!(n_counters % 3));
+  n_measures = n_counters / 3;
+  for (i = 0; i < n_measures; i++, counters += 3)
+    {
+      value = gcov_read_counter ();
+      counter = gcov_read_counter ();
+      all = gcov_read_counter ();
+
+      if (counters[0] == value)
+        counters[1] += counter;
+      else if (counter > counters[1])
+        {
+          counters[0] = value;
+          counters[1] = counter - counters[1];
+        }
+      else
+        counters[1] -= counter;
+      counters[2] += all;
+    }
+}
+#endif /* L_gcov_merge_single */
+
+#ifdef L_gcov_merge_delta
+/* The profile merging function for choosing the most common
+   difference between two consecutive evaluations of the value.  It is
+   given an array COUNTERS of N_COUNTERS old counters and it reads the
+   same number of counters from the gcov file.  The counters are split
+   into 4-tuples where the members of the tuple have meanings:
+
+   -- the last value of the measured entity
+   -- the stored candidate on the most common difference
+   -- counter
+   -- total number of evaluations of the value  */
+void
+__gcov_merge_delta (gcov_type *counters, unsigned n_counters)
+{
+  unsigned i, n_measures;
+  gcov_type value, counter, all;
+
+  gcc_assert (!(n_counters % 4));
+  n_measures = n_counters / 4;
+  for (i = 0; i < n_measures; i++, counters += 4)
+    {
+      /* last = */ gcov_read_counter ();
+      value = gcov_read_counter ();
+      counter = gcov_read_counter ();
+      all = gcov_read_counter ();
+
+      if (counters[1] == value)
+        counters[2] += counter;
+      else if (counter > counters[2])
+        {
+          counters[1] = value;
+          counters[2] = counter - counters[2];
+        }
+      else
+        counters[2] -= counter;
+      counters[3] += all;
+    }
+}
+#endif /* L_gcov_merge_delta */
+#endif /* inhibit_libc */
Index: libgcc/Makefile.in
===================================================================
--- libgcc/Makefile.in	(revision 204285)
+++ libgcc/Makefile.in	(working copy)
@@ -853,17 +853,37 @@  include $(iterator)
 # Build libgcov components.
 
 # Defined in libgcov.c, included only in gcov library
-LIBGCOV = _gcov _gcov_merge_add _gcov_merge_single _gcov_merge_delta \
-    _gcov_fork _gcov_execl _gcov_execlp _gcov_execle \
-    _gcov_execv _gcov_execvp _gcov_execve _gcov_reset _gcov_dump \
-    _gcov_interval_profiler _gcov_pow2_profiler _gcov_one_value_profiler \
+##LIBGCOV = _gcov _gcov_merge_add _gcov_merge_single _gcov_merge_delta \
+##    _gcov_fork _gcov_execl _gcov_execlp _gcov_execle \
+##    _gcov_execv _gcov_execvp _gcov_execve _gcov_reset _gcov_dump \
+##    _gcov_interval_profiler _gcov_pow2_profiler _gcov_one_value_profiler \
+##    _gcov_indirect_call_profiler _gcov_average_profiler _gcov_ior_profiler \
+##    _gcov_merge_ior _gcov_indirect_call_profiler_v2
+
+LIBGCOV_MERGE = _gcov_merge_add _gcov_merge_single _gcov_merge_delta _gcov_merge_ior
+LIBGCOV_PROFILER = _gcov_interval_profiler _gcov_pow2_profiler _gcov_one_value_profiler \
     _gcov_indirect_call_profiler _gcov_average_profiler _gcov_ior_profiler \
-    _gcov_merge_ior _gcov_indirect_call_profiler_v2
+    _gcov_indirect_call_profiler_v2
+LIBGCOV_INTERFACE = _gcov_flush _gcov_fork _gcov_execl _gcov_execlp _gcov_execle \
+    _gcov_execv _gcov_execvp _gcov_execve _gcov_reset _gcov_dump
+LIBGCOV_DRIVER = _gcov 
 
-libgcov-objects = $(patsubst %,%$(objext),$(LIBGCOV))
+libgcov-merge-objects = $(patsubst %,%$(objext),$(LIBGCOV_MERGE))
+libgcov-profiler-objects = $(patsubst %,%$(objext),$(LIBGCOV_PROFILER))
+libgcov-interface-objects = $(patsubst %,%$(objext),$(LIBGCOV_INTERFACE))
+libgcov-driver-objects = $(patsubst %,%$(objext),$(LIBGCOV_DRIVER))
+libgcov-objects = $(libgcov-merge-objects) $(libgcov-profiler-objects) \
+                 $(libgcov-interface-objects) $(libgcov-driver-objects)
 
-$(libgcov-objects): %$(objext): $(srcdir)/libgcov.c
-	$(gcc_compile) -DL$* -c $(srcdir)/libgcov.c
+$(libgcov-merge-objects): %$(objext): $(srcdir)/libgcov-merge.c
+	$(gcc_compile) -DL$* -c $(srcdir)/libgcov-merge.c
+$(libgcov-profiler-objects): %$(objext): $(srcdir)/libgcov-profiler.c
+	$(gcc_compile) -DL$* -c $(srcdir)/libgcov-profiler.c
+$(libgcov-interface-objects): %$(objext): $(srcdir)/libgcov-interface.c
+	$(gcc_compile) -DL$* -c $(srcdir)/libgcov-interface.c
+$(libgcov-driver-objects): %$(objext): $(srcdir)/libgcov-driver.c \
+  $(srcdir)/libgcov-driver-system.c
+	$(gcc_compile) -DL$* -c $(srcdir)/libgcov-driver.c
 
 
 # Static libraries.
Index: gcc/gcov-io.h
===================================================================
--- gcc/gcov-io.h	(revision 204285)
+++ gcc/gcov-io.h	(working copy)
@@ -515,6 +515,8 @@  extern void __gcov_merge_ior (gcov_type *, unsigne
 extern void __gcov_interval_profiler (gcov_type *, gcov_type, int, unsigned);
 extern void __gcov_pow2_profiler (gcov_type *, gcov_type);
 extern void __gcov_one_value_profiler (gcov_type *, gcov_type);
+extern void __gcov_indirect_call_profiler (gcov_type*, gcov_type,
+                                           void*, void*);
 extern void __gcov_indirect_call_profiler_v2 (gcov_type, void *);
 extern void __gcov_average_profiler (gcov_type *, gcov_type);
 extern void __gcov_ior_profiler (gcov_type *, gcov_type);