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Re: [RFC] libgcov.c re-factoring and offline profile-tool
- From: Teresa Johnson <tejohnson at google dot com>
- To: Xinliang David Li <davidxl at google dot com>
- Cc: Jan Hubicka <hubicka at ucw dot cz>, Rong Xu <xur at google dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Tue, 17 Dec 2013 07:48:50 -0800
- Subject: Re: [RFC] libgcov.c re-factoring and offline profile-tool
- Authentication-results: sourceware.org; auth=none
- References: <20131111150245 dot GB6009 at atrey dot karlin dot mff dot cuni dot cz> <CAF1bQ=RSUQdE0tkeqeHnbiNkC=PFPDU6O+zLFNA6jUxqV_aAbg at mail dot gmail dot com> <CAF1bQ=SCtewMrgjcYg4v21jA8uWy_9U=9sB9ULznS=9tdJD8mQ at mail dot gmail dot com> <CAF1bQ=TyNC_rAo1V8Zk9ovOvYAtpqVtep_h7WNLk6v6ZerdcaQ at mail dot gmail dot com> <20131206142319 dot GC32664 at kam dot mff dot cuni dot cz> <CAAe5K+UouGttAzYMwqHtyMSu2sD=KSVhGZ=5oySq=a-7oy2rwg at mail dot gmail dot com> <CAAe5K+XCo9S4Sx3wbeQcPHvyssPGV9Njoz3s7EK6j+kFkZZ9dg at mail dot gmail dot com> <CAAkRFZJ12Z_DOLgbGNqk0iFkx=aai4JxWgp2vaZdM2-4VWPWKg at mail dot gmail dot com> <CAAe5K+WZTGm-7=L-p2FO9qY4xOCteNQDsE=Eb_bPo+FPdvMR1g at mail dot gmail dot com> <CAAkRFZKq90ULrKLL30dGtHuHmX+BuRytdMzcCfz4kjy_5=JF3w at mail dot gmail dot com> <20131216223441 dot GC2519 at kam dot mff dot cuni dot cz> <CAAkRFZJ0XdzDvT4XPvHum+0ArzjYDUpepkJwJMg0=UfRk1GJiw at mail dot gmail dot com>
On Mon, Dec 16, 2013 at 2:48 PM, Xinliang David Li <davidxl@google.com> wrote:
> Ok -- gcov_write_counter and gcov_write_tag_length are qualified as
> low level primitives for basic gcov format and probably should be kept
> in gcov-io.c.
>
> gcov_rewrite is petty much libgcov runtime implementation details so I
> think it should be moved out. gcov_write_summary is not related to
> gcov low level format either, neither is gcov_seek. Ok for them to be
> moved?
After looking at these some more, with the idea that gcov-io.c should
encapsulate the lower level IO routines, then I think all of these
(including gcov_rewrite) should remain in gcov-io.c. I think
gcov_write_summary belongs there since all of the other gcov_write_*
are there. And gcov_seek and gcov_rewrite are both adjusting gcov_var
fields to affect the file IO operations. And there are currently no
references to gcov_var within libgcc/libgcov* files.
So I think we should leave the patch as-is. Honza, is the current
patch ok for trunk?
Thanks,
Teresa
>
> thanks,
>
> David
>
>
> On Mon, Dec 16, 2013 at 2:34 PM, Jan Hubicka <hubicka@ucw.cz> wrote:
>>> I think so -- they are private to libgcov. Honza, what do you think?
>>
>> Hmm, the purpose of gcov-io was to be low level IO library for the basic
>> gcov file format. I am not sure if gcov_write_tag_length should really resist
>> in other file than gcov_write_tag.
>>
>> I see a desire to isolate actual stdio calls so one can have replacement driver
>> for i.e. Linux kernel. For that reason things like gcov_seek and friends probably
>> should be separated, but what is reason for splitting the file handling itself?
>>
>> Honza
>>>
>>> thanks,
>>>
>>> David
>>>
>>> On Mon, Dec 16, 2013 at 1:17 PM, Teresa Johnson <tejohnson@google.com> wrote:
>>> > On Mon, Dec 16, 2013 at 12:55 PM, Xinliang David Li <davidxl@google.com> wrote:
>>> >> gcov_rewrite function is only needed (and defined) with IN_LIBGCOV.
>>> >> Should it be moved from common file gcov-io.c to libgcov.c?
>>> >
>>> > Possibly. I just looked through gcov-io.c and there are several
>>> > additional functions that are only defined under "#ifdef IN_LIBGCOV"
>>> > and only used in libgcov*c (or each other):
>>> >
>>> > gcov_write_counter
>>> > gcov_write_tag_length
>>> > gcov_write_summary
>>> > gcov_seek
>>> >
>>> > Should they all, plus gcov_rewrite, be moved to libgcov-driver.c?
>>> >
>>> > Teresa
>>> >
>>> >>
>>> >>
>>> >> David
>>> >>
>>> >> On Thu, Dec 12, 2013 at 12:11 PM, Teresa Johnson <tejohnson@google.com> wrote:
>>> >>> On Wed, Dec 11, 2013 at 10:05 PM, Teresa Johnson <tejohnson@google.com> wrote:
>>> >>>> On Fri, Dec 6, 2013 at 6:23 AM, Jan Hubicka <hubicka@ucw.cz> wrote:
>>> >>>>>> Hi, all
>>> >>>>>>
>>> >>>>>> This is the new patch for gcov-tool (previously profile-tool).
>>> >>>>>>
>>> >>>>>> Honza: can you comment on the new merge interface? David posted some
>>> >>>>>> comments in an earlier email and we want to know what's your opinion.
>>> >>>>>>
>>> >>>>>> Test patch has been tested with boostrap, regresssion,
>>> >>>>>> profiledbootstrap and SPEC2006.
>>> >>>>>>
>>> >>>>>> Noticeable changes from the earlier version:
>>> >>>>>>
>>> >>>>>> 1. create a new file libgcov.h and move libgcov-*.h headers to libgcov.h
>>> >>>>>> So we can included multiple libgcov-*.c without adding new macros.
>>> >>>>>>
>>> >>>>>> 2. split libgcov.h specific code in gcvo-io.h to libcc/libgcov.h
>>> >>>>>> Avoid multiple-page of code under IN_LIBGCOV macro -- this
>>> >>>>>> improves the readability.
>>> >>>>>>
>>> >>>>>> 3. make gcov_var static, and move the definition from gcov-io.h to
>>> >>>>>> gcov-io.c. Also
>>> >>>>>> move some static functions accessing gcov_var to gcvo-io.c
>>> >>>>>> Current code rely on GCOV_LINKAGE tricks to avoid multi-definition. I don't see
>>> >>>>>> a reason that gcov_var needs to exposed as a global.
>>> >>>>>>
>>> >>>>>> 4. expose gcov_write_strings() and gcov_sync() to gcov_tool usage
>>> >>>>>>
>>> >>>>>> 5. rename profile-tool to gcov-tool per Honza's suggestion.
>>> >>>>>>
>>> >>>>>> Thanks,
>>> >>>>>
>>> >>>>> Hi,
>>> >>>>> I did not read in deatil the gcov-tool source itself, but lets first make the interface changes
>>> >>>>> needed.
>>> >>>>>
>>> >>>>>> 2013-11-18 Rong Xu <xur@google.com>
>>> >>>>>>
>>> >>>>>> * gcc/gcov-io.c (gcov_var): Moved from gcov-io.h and make it static.
>>> >>>>>> (gcov_position): Move from gcov-io.h
>>> >>>>>> (gcov_is_error): Ditto.
>>> >>>>>> (gcov_rewrite): Ditto.
>>> >>>>>> * gcc/gcov-io.h: Re-factoring. Move gcov_var to gcov-io.h and
>>> >>>>>> move the libgcov only part of libgcc/libgcov.h.
>>> >>>>>> * libgcc/libgcov.h: New common header files for libgcov-*.h
>>> >>>>>> * libgcc/Makefile.in: Add dependence to libgcov.h
>>> >>>>>> * libgcc/libgcov-profiler.c: Use libgcov.h
>>> >>>>>> * libgcc/libgcov-driver.c: Ditto.
>>> >>>>>> * libgcc/libgcov-interface.c: Ditto.
>>> >>>>>> * libgcc/libgcov-driver-system.c (allocate_filename_struct): use
>>> >>>>>> xmalloc instread of malloc.
>>> >>>>>> * libgcc/libgcov-merge.c (void __gcov_merge_delta): Add more
>>> >>>>>> parameters to merge function.
>>> >>>>>> (__gcov_merge_add): Ditto.
>>> >>>>>> (__gcov_merge_ior): Ditto.
>>> >>>>>> (__gcov_merge_time_profile): Ditto.
>>> >>>>>> (__gcov_merge_single): Ditto.
>>> >>>>>> (__gcov_merge_delta): Ditto.
>>> >>>>>> * libgcc/libgcov-tool.c (void gcov_tool_set_verbose): New for
>>> >>>>>> gcov-tool support.
>>> >>>>>> (set_fn_ctrs): Ditto.
>>> >>>>>> (tag_function): Ditto.
>>> >>>>>> (tag_blocks): Ditto.
>>> >>>>>> (tag_arcs): Ditto.
>>> >>>>>> (tag_lines): Ditto.
>>> >>>>>> (tag_counters): Ditto.
>>> >>>>>> (tag_summary): Ditto.
>>> >>>>>> (read_gcda_finalize): Ditto.
>>> >>>>>> (read_gcda_file): Ditto.
>>> >>>>>> (ftw_read_file): Ditto.
>>> >>>>>> (read_profile_dir_init) Ditto.:
>>> >>>>>> (gcov_read_profile_dir): Ditto.
>>> >>>>>> (gcov_merge): Ditto.
>>> >>>>>> (find_match_gcov_inf Ditto.o):
>>> >>>>>> (gcov_profile_merge): Ditto.
>>> >>>>>> (__gcov_scale_add): Ditto.
>>> >>>>>> (__gcov_scale_ior): Ditto.
>>> >>>>>> (__gcov_scale_delta): Ditto.
>>> >>>>>> (__gcov_scale_single): Ditto.
>>> >>>>>> (gcov_profile_scale): Ditto.
>>> >>>>>> (gcov_profile_normalize): Ditto.
>>> >>>>>> (__gcov_scale2_add): Ditto.
>>> >>>>>> (__gcov_scale2_ior): Ditto.
>>> >>>>>> (__gcov_scale2_delta): Ditto.
>>> >>>>>> (__gcov_scale2_single): Ditto.
>>> >>>>>> (gcov_profile_scale2): Ditto.
>>> >>>>>> * gcc/gcov-tool.c (unlink_file): Gcov-tool driver support.
>>> >>>>>> (unlink_dir): Ditto.
>>> >>>>>> (profile_merge): Ditto.
>>> >>>>>> (print_merge_usage_message): Ditto.
>>> >>>>>> (merge_usage): Ditto.
>>> >>>>>> (do_merge): Ditto.
>>> >>>>>> (profile_rewrite2): Ditto.
>>> >>>>>> (profile_rewrite): Ditto.
>>> >>>>>> (print_rewrite_usage_message): Ditto.
>>> >>>>>> (rewrite_usage): Ditto.
>>> >>>>>> (do_rewrite): Ditto.
>>> >>>>>> (print_usage): Ditto.
>>> >>>>>> (print_version): Ditto.
>>> >>>>>> (process_args): Ditto.
>>> >>>>>> (main): Ditto.
>>> >>>>>> * gcc/Makefile.in: Build and install gcov-tool.
>>> >>>>>
>>> >>>>>> Index: gcc/gcov-io.c
>>> >>>>>> ===================================================================
>>> >>>>>> --- gcc/gcov-io.c (revision 204895)
>>> >>>>>> +++ gcc/gcov-io.c (working copy)
>>> >>>>>> @@ -36,6 +36,37 @@ static const gcov_unsigned_t *gcov_read_words (uns
>>> >>>>>> static void gcov_allocate (unsigned);
>>> >>>>>> #endif
>>> >>>>>>
>>> >>>>>> +/* Moved for gcov-io.h and make it static. */
>>> >>>>>> +static struct gcov_var gcov_var;
>>> >>>>>
>>> >>>>> This is more an changelog message than a comment in source file.
>>> >>>>> Just describe what gcov_var is.
>>> >>>>
>>> >>>> I changed this so gcov_var is no longer static, but global as before.
>>> >>>>
>>> >>>>>
>>> >>>>> Do you know how the size of libgcov changed with your patch?
>>> >>>>> Quick check of current mainline on compiling empty main gives:
>>> >>>>>
>>> >>>>> jh@gcc10:~/trunk/build/gcc$ cat t.c
>>> >>>>> main()
>>> >>>>> {
>>> >>>>> }
>>> >>>>> jh@gcc10:~/trunk/build/gcc$ ./xgcc -B ./ -O2 -fprofile-generate -o a.out-new --static t.c
>>> >>>>> jh@gcc10:~/trunk/build/gcc$ gcc -O2 -fprofile-generate -o a.out-old --static t.c
>>> >>>>> jh@gcc10:~/trunk/build/gcc$ size a.out-old
>>> >>>>> text data bss dec hex filename
>>> >>>>> 608141 3560 16728 628429 996cd a.out-old
>>> >>>>> jh@gcc10:~/trunk/build/gcc$ size a.out-new
>>> >>>>> text data bss dec hex filename
>>> >>>>> 612621 3688 22880 639189 9c0d5 a.out-new
>>> >>>>>
>>> >>>>> Without profiling I get:
>>> >>>>> jh@gcc10:~/trunk/build/gcc$ size a.out-new-no
>>> >>>>> jh@gcc10:~/trunk/build/gcc$ size a.out-old-no
>>> >>>>> text data bss dec hex filename
>>> >>>>> 599719 3448 12568 615735 96537 a.out-old-no
>>> >>>>> text data bss dec hex filename
>>> >>>>> 600247 3448 12568 616263 96747 a.out-new-no
>>> >>>>>
>>> >>>>> Quite big for empty program, but mostly glibc fault, I suppose
>>> >>>>> (that won't be an issue for embedded platforms). But anyway
>>> >>>>> we increased text size overhead from 8k to 12k, BSS size
>>> >>>>> overhead from 4k to 10k and data by another 1k.
>>> >>>>>
>>> >>>>> text data bss dec hex filename
>>> >>>>> 126 0 0 126 7e _gcov_merge_add.o (ex libgcov.a)
>>> >>>>> 251 0 0 251 fb _gcov_merge_single.o (ex libgcov.a)
>>> >>>>> 242 0 0 242 f2 _gcov_merge_delta.o (ex libgcov.a)
>>> >>>>> 126 0 0 126 7e _gcov_merge_ior.o (ex libgcov.a)
>>> >>>>> 156 0 0 156 9c _gcov_merge_time_profile.o (ex libgcov.a)
>>> >>>>> 89 0 0 89 59 _gcov_interval_profiler.o (ex libgcov.a)
>>> >>>>> 69 0 0 69 45 _gcov_pow2_profiler.o (ex libgcov.a)
>>> >>>>> 115 0 0 115 73 _gcov_one_value_profiler.o (ex libgcov.a)
>>> >>>>> 122 0 0 122 7a _gcov_indirect_call_profiler.o (ex libgcov.a)
>>> >>>>> 57 0 0 57 39 _gcov_average_profiler.o (ex libgcov.a)
>>> >>>>> 52 0 0 52 34 _gcov_ior_profiler.o (ex libgcov.a)
>>> >>>>> 178 0 16 194 c2 _gcov_indirect_call_profiler_v2.o (ex libgcov.a)
>>> >>>>> 77 0 8 85 55 _gcov_time_profiler.o (ex libgcov.a)
>>> >>>>> 126 0 40 166 a6 _gcov_flush.o (ex libgcov.a)
>>> >>>>> 101 0 0 101 65 _gcov_fork.o (ex libgcov.a)
>>> >>>>> 471 0 0 471 1d7 _gcov_execl.o (ex libgcov.a)
>>> >>>>> 471 0 0 471 1d7 _gcov_execlp.o (ex libgcov.a)
>>> >>>>> 524 0 0 524 20c _gcov_execle.o (ex libgcov.a)
>>> >>>>> 98 0 0 98 62 _gcov_execv.o (ex libgcov.a)
>>> >>>>> 98 0 0 98 62 _gcov_execvp.o (ex libgcov.a)
>>> >>>>> 108 0 0 108 6c _gcov_execve.o (ex libgcov.a)
>>> >>>>> 66 0 0 66 42 _gcov_reset.o (ex libgcov.a)
>>> >>>>> 66 0 0 66 42 _gcov_dump.o (ex libgcov.a)
>>> >>>>> 9505 0 6144 15649 3d21 _gcov.o (ex libgcov.a)
>>> >>>>>
>>> >>>>> I think we definitely need to move those 6k of bss space out. I think those are new
>>> >>>>> static vars you introduced that I think are unsafe anyway because multiple streaming
>>> >>>>> may run at once in threaded program where locking mechanizm fails.
>>> >>>>> (it will probably do other bad things, but definitely we do not want to
>>> >>>>> conflict on things like filename to write into).
>>> >>>>>
>>> >>>>> Compared to my system gcov:
>>> >>>>> text data bss dec hex filename
>>> >>>>> 9765 0 64 9829 2665 _gcov.o (ex ./lib64/gcc/x86_64-suse-linux/4.8/libgcov.a)
>>> >>>>> 125 0 0 125 7d _gcov_merge_add.o (ex ./lib64/gcc/x86_64-suse-linux/4.8/libgcov.a)
>>> >>>>> 251 0 0 251 fb _gcov_merge_single.o (ex ./lib64/gcc/x86_64-suse-linux/4.8/libgcov.a)
>>> >>>>> 242 0 0 242 f2 _gcov_merge_delta.o (ex ./lib64/gcc/x86_64-suse-linux/4.8/libgcov.a)
>>> >>>>> 101 0 0 101 65 _gcov_fork.o (ex ./lib64/gcc/x86_64-suse-linux/4.8/libgcov.a)
>>> >>>>> 471 0 0 471 1d7 _gcov_execl.o (ex ./lib64/gcc/x86_64-suse-linux/4.8/libgcov.a)
>>> >>>>> 471 0 0 471 1d7 _gcov_execlp.o (ex ./lib64/gcc/x86_64-suse-linux/4.8/libgcov.a)
>>> >>>>> 524 0 0 524 20c _gcov_execle.o (ex ./lib64/gcc/x86_64-suse-linux/4.8/libgcov.a)
>>> >>>>> 98 0 0 98 62 _gcov_execv.o (ex ./lib64/gcc/x86_64-suse-linux/4.8/libgcov.a)
>>> >>>>> 98 0 0 98 62 _gcov_execvp.o (ex ./lib64/gcc/x86_64-suse-linux/4.8/libgcov.a)
>>> >>>>> 108 0 0 108 6c _gcov_execve.o (ex ./lib64/gcc/x86_64-suse-linux/4.8/libgcov.a)
>>> >>>>> 72 0 0 72 48 _gcov_reset.o (ex ./lib64/gcc/x86_64-suse-linux/4.8/libgcov.a)
>>> >>>>> 72 0 0 72 48 _gcov_dump.o (ex ./lib64/gcc/x86_64-suse-linux/4.8/libgcov.a)
>>> >>>>> 89 0 0 89 59 _gcov_interval_profiler.o (ex ./lib64/gcc/x86_64-suse-linux/4.8/libgcov.a)
>>> >>>>> 69 0 0 69 45 _gcov_pow2_profiler.o (ex ./lib64/gcc/x86_64-suse-linux/4.8/libgcov.a)
>>> >>>>> 115 0 0 115 73 _gcov_one_value_profiler.o (ex ./lib64/gcc/x86_64-suse-linux/4.8/libgcov.a)
>>> >>>>> 122 0 0 122 7a _gcov_indirect_call_profiler.o (ex ./lib64/gcc/x86_64-suse-linux/4.8/libgcov.a)
>>> >>>>> 57 0 0 57 39 _gcov_average_profiler.o (ex ./lib64/gcc/x86_64-suse-linux/4.8/libgcov.a)
>>> >>>>> 52 0 0 52 34 _gcov_ior_profiler.o (ex ./lib64/gcc/x86_64-suse-linux/4.8/libgcov.a)
>>> >>>>> 125 0 0 125 7d _gcov_merge_ior.o (ex ./lib64/gcc/x86_64-suse-linux/4.8/libgcov.a)
>>> >>>>>
>>> >>>>>> Index: gcc/gcov-io.h
>>> >>>>>> ===================================================================
>>> >>>>>> --- gcc/gcov-io.h (revision 204895)
>>> >>>>>> +++ gcc/gcov-io.h (working copy)
>>> >>>>>> @@ -164,51 +164,7 @@ see the files COPYING3 and COPYING.RUNTIME respect
>>> >>>>>> #ifndef GCC_GCOV_IO_H
>>> >>>>>> #define GCC_GCOV_IO_H
>>> >>>>>>
>>> >>>>>> -#if IN_LIBGCOV
>>> >>>>>> -/* About the target */
>>> >>>>>> -
>>> >>>>>> -#if BITS_PER_UNIT == 8
>>> >>>>>> -typedef unsigned gcov_unsigned_t __attribute__ ((mode (SI)));
>>> >>>>>> -typedef unsigned gcov_position_t __attribute__ ((mode (SI)));
>>> >>>>>> -#if LONG_LONG_TYPE_SIZE > 32
>>> >>>>>> -typedef signed gcov_type __attribute__ ((mode (DI)));
>>> >>>>>> -typedef unsigned gcov_type_unsigned __attribute__ ((mode (DI)));
>>> >>>>>> -#else
>>> >>>>>> -typedef signed gcov_type __attribute__ ((mode (SI)));
>>> >>>>>> -typedef unsigned gcov_type_unsigned __attribute__ ((mode (SI)));
>>> >>>>>> -#endif
>>> >>>>>> -#else
>>> >>>>>> -#if BITS_PER_UNIT == 16
>>> >>>>>> -typedef unsigned gcov_unsigned_t __attribute__ ((mode (HI)));
>>> >>>>>> -typedef unsigned gcov_position_t __attribute__ ((mode (HI)));
>>> >>>>>> -#if LONG_LONG_TYPE_SIZE > 32
>>> >>>>>> -typedef signed gcov_type __attribute__ ((mode (SI)));
>>> >>>>>> -typedef unsigned gcov_type_unsigned __attribute__ ((mode (SI)));
>>> >>>>>> -#else
>>> >>>>>> -typedef signed gcov_type __attribute__ ((mode (HI)));
>>> >>>>>> -typedef unsigned gcov_type_unsigned __attribute__ ((mode (HI)));
>>> >>>>>> -#endif
>>> >>>>>> -#else
>>> >>>>>> -typedef unsigned gcov_unsigned_t __attribute__ ((mode (QI)));
>>> >>>>>> -typedef unsigned gcov_position_t __attribute__ ((mode (QI)));
>>> >>>>>> -#if LONG_LONG_TYPE_SIZE > 32
>>> >>>>>> -typedef signed gcov_type __attribute__ ((mode (HI)));
>>> >>>>>> -typedef unsigned gcov_type_unsigned __attribute__ ((mode (HI)));
>>> >>>>>> -#else
>>> >>>>>> -typedef signed gcov_type __attribute__ ((mode (QI)));
>>> >>>>>> -typedef unsigned gcov_type_unsigned __attribute__ ((mode (QI)));
>>> >>>>>> -#endif
>>> >>>>>> -#endif
>>> >>>>>> -#endif
>>> >>>>>
>>> >>>>> So this part basically moves libgcov specific bits into libgcov.h? That OK fine by
>>> >>>>> itself.
>>> >>>>>> Index: libgcc/libgcov-profiler.c
>>> >>>>>> ===================================================================
>>> >>>>>> --- libgcc/libgcov-profiler.c (revision 204895)
>>> >>>>>> +++ libgcc/libgcov-profiler.c (working copy)
>>> >>>>>> @@ -23,15 +23,8 @@ a copy of the GCC Runtime Library Exception along
>>> >>>>>> 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 "libgcov.h"
>>> >>>>>> #if !defined(inhibit_libc)
>>> >>>>>> -#define IN_LIBGCOV 1
>>> >>>>>> -#include "gcov-io.h"
>>> >>>>>
>>> >>>>> I did not pay that much attention into the current include file changes, but wasn't
>>> >>>>> idea to avoid #include file to include random other #includes?
>>> >>>>> So perhaps the first block of includes should stay, followed by libgcov.h and gcov-io.h
>>> >>>>> last?
>>> >>>>
>>> >>>> I'm not sure I understand the issue here? The patch basically moves
>>> >>>> the same includes into libgcov.h, and includes that instead. I see
>>> >>>> many other header files in gcc that include other headers.
>>> >>>>
>>> >>>>>> @@ -325,6 +311,9 @@ static struct gcov_summary all_prg;
>>> >>>>>> #endif
>>> >>>>>> /* crc32 for this program. */
>>> >>>>>> static gcov_unsigned_t crc32;
>>> >>>>>> +/* Use this summary checksum rather the computed one if the value is
>>> >>>>>> + * non-zero. */
>>> >>>>>> +static gcov_unsigned_t saved_summary_checksum;
>>> >>>>>
>>> >>>>> Why do you need to save the checksum? Won't it reset summary back with multiple streaming?
>>> >>>>
>>> >>>> This has been removed.
>>> >>>>
>>> >>>>>
>>> >>>>> I would really like to avoid introducing those static vars that are used exclusively
>>> >>>>> by gcov_exit. What about putting them into an gcov_context structure that
>>> >>>>> is passed around the functions that was broken out?
>>> >>>>>> Index: libgcc/libgcov-merge.c
>>> >>>>>> ===================================================================
>>> >>>>>> --- libgcc/libgcov-merge.c (revision 204895)
>>> >>>>>> +++ libgcc/libgcov-merge.c (working copy)
>>> >>>>>> @@ -23,107 +23,150 @@ a copy of the GCC Runtime Library Exception along
>>> >>>>>> 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 "libgcov.h"
>>> >>>>>>
>>> >>>>>> -#if defined(inhibit_libc)
>>> >>>>>> -#define IN_LIBGCOV (-1)
>>> >>>>>> -#else
>>> >>>>>> -#define IN_LIBGCOV 1
>>> >>>>>> +#include "gcov-io-libgcov.h"
>>> >>>>>> #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))) {}
>>> >>>>>> + unsigned n_counters __attribute__ ((unused)),
>>> >>>>>> + unsigned gcov_type *src __attribute__ ((unused)),
>>> >>>>>> + unsigned w __attribute__ ((unused))) {}
>>> >>>>>> #endif
>>> >>>>>>
>>> >>>>>> #ifdef L_gcov_merge_single
>>> >>>>>> void __gcov_merge_single (gcov_type *counters __attribute__ ((unused)),
>>> >>>>>> - unsigned n_counters __attribute__ ((unused))) {}
>>> >>>>>> + unsigned n_counters __attribute__ ((unused)),
>>> >>>>>> + unsigned gcov_type *src __attribute__ ((unused)),
>>> >>>>>> + unsigned w __attribute__ ((unused))) {}
>>> >>>>>> #endif
>>> >>>>>>
>>> >>>>>> #ifdef L_gcov_merge_delta
>>> >>>>>> void __gcov_merge_delta (gcov_type *counters __attribute__ ((unused)),
>>> >>>>>> - unsigned n_counters __attribute__ ((unused))) {}
>>> >>>>>> + unsigned n_counters __attribute__ ((unused)),
>>> >>>>>> + unsigned gcov_type *src __attribute__ ((unused)),
>>> >>>>>> + unsigned w __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. */
>>> >>>>>> + an array COUNTERS of N_COUNTERS old counters.
>>> >>>>>> + When SRC==NULL, it reads the same number of counters from the gcov file.
>>> >>>>>> + Otherwise, it reads from SRC array. These read values will be multiplied
>>> >>>>>> + by weight W before adding to the old counters. */
>>> >>>>>> void
>>> >>>>>> -__gcov_merge_add (gcov_type *counters, unsigned n_counters)
>>> >>>>>> +__gcov_merge_add (gcov_type *counters, unsigned n_counters,
>>> >>>>>> + gcov_type *src, unsigned w)
>>> >>>>>> {
>>> >>>>>> + int in_mem = (src != 0);
>>> >>>>>> +
>>> >>>>>> for (; n_counters; counters++, n_counters--)
>>> >>>>>> - *counters += gcov_read_counter ();
>>> >>>>>> + {
>>> >>>>>> + gcov_type value;
>>> >>>>>> +
>>> >>>>>> + if (in_mem)
>>> >>>>>> + value = *(src++);
>>> >>>>>> + else
>>> >>>>>> + value = gcov_read_counter ();
>>> >>>>>> +
>>> >>>>>> + *counters += w * value;
>>> >>>>>> + }
>>> >>>>>> }
>>> >>>>>> #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. */
>>> >>>>>> + an array COUNTERS of N_COUNTERS old counters.
>>> >>>>>> + When SRC==NULL, it reads the same number of counters from the gcov file.
>>> >>>>>> + Otherwise, it reads from SRC array. */
>>> >>>>>> void
>>> >>>>>> -__gcov_merge_ior (gcov_type *counters, unsigned n_counters)
>>> >>>>>> +__gcov_merge_ior (gcov_type *counters, unsigned n_counters,
>>> >>>>>> + gcov_type *src, unsigned w __attribute__ ((unused)))
>>> >>>>>
>>> >>>>> So the new in-memory variants are introduced for merging tool, while libgcc use gcov_read_counter
>>> >>>>> interface?
>>> >>>>> Perhaps we can actually just duplicate the functions to avoid runtime to do all the scalling
>>> >>>>> and in_mem tests it won't need?
>>> >>>>>
>>> >>>>> I would suggest going with libgcov.h changes and clenaups first, with interface changes next
>>> >>>>> and the gcov-tool is probably quite obvious at the end?
>>> >>>>> Do you think you can split the patch this way?
>>> >>>>>
>>> >>>>> Thanks and sorry for taking long to review. I should have more time again now.
>>> >>>>> Honza
>>> >>>>
>>> >>>> The libgcov.h related changes are in the attached patch. I think it
>>> >>>> addresses your concerns. Bootstrapped and tested on
>>> >>>> x86-64-unknown-linux-gnu. A profiledbootstrap is in progress.
>>> >>>>
>>> >>>> Ok for trunk if profiledbootstrap passes?
>>> >>>
>>> >>> Both a profiledbootstrap and LTO profiledbootstrap pass.
>>> >>>
>>> >>> Teresa
>>> >>>
>>> >>>>
>>> >>>> Thanks,
>>> >>>> Teresa
>>> >>>>
>>> >>>>
>>> >>>> --
>>> >>>> Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413
>>> >>>
>>> >>>
>>> >>>
>>> >>> --
>>> >>> Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413
>>> >
>>> >
>>> >
>>> > --
>>> > Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413
--
Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413