[google] Patch to add compiler flag to dump callgraph edge profiles in special .note sections

[Sriraman, 2011-06-08 02:05:06]

Patch Description: ================= I am working on a project to do global function layout in the linker where the linker reads the callgraph edge profile information, generated by FDO, and uses that to find a ordering of functions that will place functions calling each other frequently closer, like the Pettis-Hansen code ordering algorithm described in the paper "Profile-guided Code Poisitioning" in PLDI 1990. This patch adds a flag that allows the callgraph edge profile information to be stored .note sections called ".note.callgraph.text". The new compiler flag -fcallgraph-profiles-sections generates these sections and must be used along with -fprofile-use. I have added a PARAM to only output callgraph edges greater than a specified threshold. Once this is available, the linker can read these sections and generate a global callgraph which can be used to determine a global function ordering. I am adding plugin support in the gold linker to allow linker plugins to be able to read the contents of sections and also adding plugin hooks to specify a desired ordering of functions to the linker. The linker patch is available here : http://sourceware.org/ml/binutils/2011-03/msg00043.html. Once this is available, linker plugins can be used to determine the function layout, like the Pettis-Hansen algorithm, of the final binary. Example: The new .note.callgraph.text sections looks like this for a function foo that calls bar 100 times and zap 50 times: **************************** .section	.note.callgraph.text._Z3foov,"",@progbits	.string "Function _Z3foov"	.string "_Z3barv"	.string "100"	.string "_Z3zapv"	.string "50" *************************** For now, this is for google/main. I will re-submit for review to trunk along with data layout. Google ref 41940 2011-06-07 Sriraman Tallam <tmsriram@google.com>	* doc/invoke.texi: document option -fcallgraph-profiles-sections.	* final.c (dump_cgraph_profiles): New function.	(rest_of_handle_final): Create new section '.note.callgraph.text'	with compiler flag -fcallgraph-profiles-sections	* common.opt: New option -fcallgraph-profiles-sections.	* params.def (DEFPARAM): New param PARAM_NOTE_CGRAPH_SECTION_EDGE_THRESHOLD. Index: doc/invoke.texi =================================================================== --- doc/invoke.texi	(revision 174789) +++ doc/invoke.texi	(working copy) @@ -351,7 +351,7 @@ Objective-C and Objective-C++ Dialects}. -falign-labels[=@var{n}] -falign-loops[=@var{n}] -fassociative-math @gol -fauto-inc-dec -fbranch-probabilities -fbranch-target-load-optimize @gol -fbranch-target-load-optimize2 -fbtr-bb-exclusive -fcaller-saves @gol --fcheck-data-deps -fclone-hot-version-paths @gol +-fcallgraph-profiles-sections -fcheck-data-deps -fclone-hot-version-paths @gol -fcombine-stack-adjustments -fconserve-stack @gol -fcompare-elim -fcprop-registers -fcrossjumping @gol -fcse-follow-jumps -fcse-skip-blocks -fcx-fortran-rules @gol @@ -8114,6 +8114,15 @@ Do not promote static functions with always inline @opindex fripa-verbose Enable printing of verbose information about dynamic inter-procedural optimizations. This is used in conjunction with the @option{-fripa}. + +@item -fcallgraph-profiles-sections +@opindex fcallgraph-profiles-sections +Emit call graph edge profile counts in .note.callgraph.text sections. This is +used in conjunction with @option{-fprofile-use}. A new .note.callgraph.text +section is created for each function. This section lists every callee and the +number of times it is called. The params variable +"note-cgraph-section-edge-threshold" can be used to only list edges above a +certain threshold. @end table The following options control compiler behavior regarding floating Index: final.c =================================================================== --- final.c	(revision 174789) +++ final.c	(working copy) @@ -4321,13 +4321,37 @@ debug_free_queue (void) symbol_queue_size = 0; } } - + +/* List the call graph profiled edges whise value is greater than + PARAM_NOTE_CGRAPH_SECTION_EDGE_THRESHOLD in the + ".note.callgraph.text" section. */ +static void +dump_cgraph_profiles (void) +{ + struct cgraph_node *node = cgraph_node (current_function_decl); + struct cgraph_edge *e; + struct cgraph_node *callee; + + for (e = node->callees; e != NULL; e = e->next_callee) + { + if (e->count <= PARAM_VALUE (PARAM_NOTE_CGRAPH_SECTION_EDGE_THRESHOLD)) + continue; + callee = e->callee; + fprintf (asm_out_file, "\t.string \"%s\"\n", + IDENTIFIER_POINTER (decl_assembler_name (callee->decl))); + fprintf (asm_out_file, "\t.string \"" HOST_WIDEST_INT_PRINT_DEC "\"\n", + e->count); + } +} + /* Turn the RTL into assembly. */ static unsigned int rest_of_handle_final (void) { rtx x; const char *fnname; + char *profile_fnname; + unsigned int flags; /* Get the function's name, as described by its RTL. This may be different from the DECL_NAME name used in the source file. */ @@ -4387,6 +4411,21 @@ rest_of_handle_final (void) targetm.asm_out.destructor (XEXP (DECL_RTL (current_function_decl), 0),	decl_fini_priority_lookup (current_function_decl)); + + /* With -fcgraph-section, add ".note.callgraph.text" section for storing + profiling information. */ + if (flag_callgraph_profiles_sections + && flag_profile_use + && cgraph_node (current_function_decl) != NULL) + { + flags = SECTION_DEBUG; + asprintf (&profile_fnname, ".note.callgraph.text.%s", fnname); + switch_to_section (get_section (profile_fnname, flags, NULL)); + fprintf (asm_out_file, "\t.string \"Function %s\"\n", fnname); + dump_cgraph_profiles (); + free (profile_fnname); + } + return 0; } Index: common.opt =================================================================== --- common.opt	(revision 174789) +++ common.opt	(working copy) @@ -907,6 +907,10 @@ fcaller-saves Common Report Var(flag_caller_saves) Optimization Save registers around function calls +fcallgraph-profiles-sections +Common Report Var(flag_callgraph_profiles_sections) Init(0) +Generate .note.callgraph.text sections listing callees and edge counts. + fcheck-data-deps Common Report Var(flag_check_data_deps) Compare the results of several data dependence analyzers. Index: params.def =================================================================== --- params.def	(revision 174789) +++ params.def	(working copy) @@ -1002,6 +1002,15 @@ DEFPARAM (PARAM_MVERSN_CLONE_CGRAPH_DEPTH, "maximum length of the call graph path to be cloned " "while doing multiversioning", 2, 0, 5) + +/* Only output those call graph edges in .note.callgraph.text sections + whose count is greater than this value. */ +DEFPARAM (PARAM_NOTE_CGRAPH_SECTION_EDGE_THRESHOLD, + "note-cgraph-section-edge-threshold", + "minimum call graph edge count for inclusion in " + ".note.callgraph.text section", + 0, 0, 0) + /* Local variables: mode:c -- This patch is available for review at http://codereview.appspot.com/4591045 

[Sriraman, 2011-06-08 16:13:34]

+davidxl On Tue, Jun 7, 2011 at 7:05 PM, Sriraman Tallam <tmsriram@google.com> wrote: > Patch Description: > ================= > > I am working on a project to do global function layout in the linker where the linker reads the callgraph edge profile information, generated by FDO, and uses that to find a ordering of functions that will place functions calling each other frequently closer, like the Pettis-Hansen code ordering algorithm described in the paper "Profile-guided Code Poisitioning" in PLDI 1990. > > This patch adds a flag that allows the callgraph edge profile information to be stored .note sections called ".note.callgraph.text". The new compiler flag -fcallgraph-profiles-sections generates these sections and must be used along with -fprofile-use. I have added a PARAM to only output callgraph edges greater than a specified threshold. Once this is available, the linker can read these sections and generate a global callgraph which can be used to determine a global function ordering. > > I am adding plugin support in the gold linker to allow linker plugins to be able to read the contents of sections and also adding plugin hooks to specify a desired ordering of functions to the linker. The linker patch is available here : http://sourceware.org/ml/binutils/2011-03/msg00043.html. Once this is available, linker plugins can be used to determine the function layout, like the Pettis-Hansen algorithm, of the final binary. > > Example: The new .note.callgraph.text sections looks like this for a function foo that calls bar 100 times and zap 50 times: > **************************** > .section        .note.callgraph.text._Z3foov,"",@progbits >        .string "Function _Z3foov" >        .string "_Z3barv" >        .string "100" >        .string "_Z3zapv" >        .string "50" > *************************** > > For now, this is for google/main. I will re-submit for review to trunk along with data layout. > > Google ref 41940 > > 2011-06-07  Sriraman Tallam  <tmsriram@google.com> > >        * doc/invoke.texi: document option -fcallgraph-profiles-sections. >        * final.c  (dump_cgraph_profiles): New function. >        (rest_of_handle_final): Create new section '.note.callgraph.text' >        with compiler flag -fcallgraph-profiles-sections >        * common.opt: New option -fcallgraph-profiles-sections. >        * params.def (DEFPARAM): New param >        PARAM_NOTE_CGRAPH_SECTION_EDGE_THRESHOLD. > > Index: doc/invoke.texi > =================================================================== > --- doc/invoke.texi     (revision 174789) > +++ doc/invoke.texi     (working copy) > @@ -351,7 +351,7 @@ Objective-C and Objective-C++ Dialects}. >  -falign-labels[=@var{n}] -falign-loops[=@var{n}] -fassociative-math @gol >  -fauto-inc-dec -fbranch-probabilities -fbranch-target-load-optimize @gol >  -fbranch-target-load-optimize2 -fbtr-bb-exclusive -fcaller-saves @gol > --fcheck-data-deps -fclone-hot-version-paths @gol > +-fcallgraph-profiles-sections -fcheck-data-deps -fclone-hot-version-paths @gol >  -fcombine-stack-adjustments -fconserve-stack @gol >  -fcompare-elim -fcprop-registers -fcrossjumping @gol >  -fcse-follow-jumps -fcse-skip-blocks -fcx-fortran-rules @gol > @@ -8114,6 +8114,15 @@ Do not promote static functions with always inline >  @opindex fripa-verbose >  Enable printing of verbose information about dynamic inter-procedural optimizations. >  This is used in conjunction with the @option{-fripa}. > + > +@item -fcallgraph-profiles-sections > +@opindex fcallgraph-profiles-sections > +Emit call graph edge profile counts in .note.callgraph.text sections. This is > +used in conjunction with @option{-fprofile-use}. A new .note.callgraph.text > +section is created for each function. This section lists every callee and the > +number of times it is called. The params variable > +"note-cgraph-section-edge-threshold" can be used to only list edges above a > +certain threshold. >  @end table > >  The following options control compiler behavior regarding floating > Index: final.c > =================================================================== > --- final.c     (revision 174789) > +++ final.c     (working copy) > @@ -4321,13 +4321,37 @@ debug_free_queue (void) >       symbol_queue_size = 0; >     } >  } > - > + > +/* List the call graph profiled edges whise value is greater than > +   PARAM_NOTE_CGRAPH_SECTION_EDGE_THRESHOLD in the > +   ".note.callgraph.text" section. */ > +static void > +dump_cgraph_profiles (void) > +{ > +  struct cgraph_node *node = cgraph_node (current_function_decl); > +  struct cgraph_edge *e; > +  struct cgraph_node *callee; > + > +  for (e = node->callees; e != NULL; e = e->next_callee) > +    { > +      if (e->count <= PARAM_VALUE (PARAM_NOTE_CGRAPH_SECTION_EDGE_THRESHOLD)) > +        continue; > +      callee = e->callee; > +      fprintf (asm_out_file, "\t.string \"%s\"\n", > +               IDENTIFIER_POINTER (decl_assembler_name (callee->decl))); > +      fprintf (asm_out_file, "\t.string \"" HOST_WIDEST_INT_PRINT_DEC "\"\n", > +               e->count); > +    } > +} > + >  /* Turn the RTL into assembly.  */ >  static unsigned int >  rest_of_handle_final (void) >  { >   rtx x; >   const char *fnname; > +  char *profile_fnname; > +  unsigned int flags; > >   /* Get the function's name, as described by its RTL.  This may be >      different from the DECL_NAME name used in the source file.  */ > @@ -4387,6 +4411,21 @@ rest_of_handle_final (void) >     targetm.asm_out.destructor (XEXP (DECL_RTL (current_function_decl), 0), >                                decl_fini_priority_lookup >                                  (current_function_decl)); > + > +  /* With -fcgraph-section, add ".note.callgraph.text" section for storing > +     profiling information. */ > +  if (flag_callgraph_profiles_sections > +      && flag_profile_use > +      && cgraph_node (current_function_decl) != NULL) > +    { > +      flags = SECTION_DEBUG; > +      asprintf (&profile_fnname, ".note.callgraph.text.%s", fnname); > +      switch_to_section (get_section (profile_fnname, flags, NULL)); > +      fprintf (asm_out_file, "\t.string \"Function %s\"\n", fnname); > +      dump_cgraph_profiles (); > +      free (profile_fnname); > +    } > + >   return 0; >  } > > Index: common.opt > =================================================================== > --- common.opt  (revision 174789) > +++ common.opt  (working copy) > @@ -907,6 +907,10 @@ fcaller-saves >  Common Report Var(flag_caller_saves) Optimization >  Save registers around function calls > > +fcallgraph-profiles-sections > +Common Report Var(flag_callgraph_profiles_sections) Init(0) > +Generate .note.callgraph.text sections listing callees and edge counts. > + >  fcheck-data-deps >  Common Report Var(flag_check_data_deps) >  Compare the results of several data dependence analyzers. > Index: params.def > =================================================================== > --- params.def  (revision 174789) > +++ params.def  (working copy) > @@ -1002,6 +1002,15 @@ DEFPARAM (PARAM_MVERSN_CLONE_CGRAPH_DEPTH, >          "maximum length of the call graph path to be cloned " >           "while doing multiversioning", >          2, 0, 5) > + > +/* Only output those call graph edges in .note.callgraph.text sections > +   whose count is greater than this value. */ > +DEFPARAM (PARAM_NOTE_CGRAPH_SECTION_EDGE_THRESHOLD, > +         "note-cgraph-section-edge-threshold", > +         "minimum call graph edge count for inclusion in " > +          ".note.callgraph.text section", > +         0, 0, 0) > + >  /* >  Local variables: >  mode:c > > -- > This patch is available for review at http://codereview.appspot.com/4591045 > 

[davidxl, 2011-06-08 16:16:11]

ok for google/main. David On Wed, Jun 8, 2011 at 9:13 AM, Sriraman Tallam <tmsriram@google.com> wrote: > +davidxl > > On Tue, Jun 7, 2011 at 7:05 PM, Sriraman Tallam <tmsriram@google.com> wrote: >> Patch Description: >> ================= >> >> I am working on a project to do global function layout in the linker where the linker reads the callgraph edge profile information, generated by FDO, and uses that to find a ordering of functions that will place functions calling each other frequently closer, like the Pettis-Hansen code ordering algorithm described in the paper "Profile-guided Code Poisitioning" in PLDI 1990. >> >> This patch adds a flag that allows the callgraph edge profile information to be stored .note sections called ".note.callgraph.text". The new compiler flag -fcallgraph-profiles-sections generates these sections and must be used along with -fprofile-use. I have added a PARAM to only output callgraph edges greater than a specified threshold. Once this is available, the linker can read these sections and generate a global callgraph which can be used to determine a global function ordering. >> >> I am adding plugin support in the gold linker to allow linker plugins to be able to read the contents of sections and also adding plugin hooks to specify a desired ordering of functions to the linker. The linker patch is available here : http://sourceware.org/ml/binutils/2011-03/msg00043.html. Once this is available, linker plugins can be used to determine the function layout, like the Pettis-Hansen algorithm, of the final binary. >> >> Example: The new .note.callgraph.text sections looks like this for a function foo that calls bar 100 times and zap 50 times: >> **************************** >> .section        .note.callgraph.text._Z3foov,"",@progbits >>        .string "Function _Z3foov" >>        .string "_Z3barv" >>        .string "100" >>        .string "_Z3zapv" >>        .string "50" >> *************************** >> >> For now, this is for google/main. I will re-submit for review to trunk along with data layout. >> >> Google ref 41940 >> >> 2011-06-07  Sriraman Tallam  <tmsriram@google.com> >> >>        * doc/invoke.texi: document option -fcallgraph-profiles-sections. >>        * final.c  (dump_cgraph_profiles): New function. >>        (rest_of_handle_final): Create new section '.note.callgraph.text' >>        with compiler flag -fcallgraph-profiles-sections >>        * common.opt: New option -fcallgraph-profiles-sections. >>        * params.def (DEFPARAM): New param >>        PARAM_NOTE_CGRAPH_SECTION_EDGE_THRESHOLD. >> >> Index: doc/invoke.texi >> =================================================================== >> --- doc/invoke.texi     (revision 174789) >> +++ doc/invoke.texi     (working copy) >> @@ -351,7 +351,7 @@ Objective-C and Objective-C++ Dialects}. >>  -falign-labels[=@var{n}] -falign-loops[=@var{n}] -fassociative-math @gol >>  -fauto-inc-dec -fbranch-probabilities -fbranch-target-load-optimize @gol >>  -fbranch-target-load-optimize2 -fbtr-bb-exclusive -fcaller-saves @gol >> --fcheck-data-deps -fclone-hot-version-paths @gol >> +-fcallgraph-profiles-sections -fcheck-data-deps -fclone-hot-version-paths @gol >>  -fcombine-stack-adjustments -fconserve-stack @gol >>  -fcompare-elim -fcprop-registers -fcrossjumping @gol >>  -fcse-follow-jumps -fcse-skip-blocks -fcx-fortran-rules @gol >> @@ -8114,6 +8114,15 @@ Do not promote static functions with always inline >>  @opindex fripa-verbose >>  Enable printing of verbose information about dynamic inter-procedural optimizations. >>  This is used in conjunction with the @option{-fripa}. >> + >> +@item -fcallgraph-profiles-sections >> +@opindex fcallgraph-profiles-sections >> +Emit call graph edge profile counts in .note.callgraph.text sections. This is >> +used in conjunction with @option{-fprofile-use}. A new .note.callgraph.text >> +section is created for each function. This section lists every callee and the >> +number of times it is called. The params variable >> +"note-cgraph-section-edge-threshold" can be used to only list edges above a >> +certain threshold. >>  @end table >> >>  The following options control compiler behavior regarding floating >> Index: final.c >> =================================================================== >> --- final.c     (revision 174789) >> +++ final.c     (working copy) >> @@ -4321,13 +4321,37 @@ debug_free_queue (void) >>       symbol_queue_size = 0; >>     } >>  } >> - >> + >> +/* List the call graph profiled edges whise value is greater than >> +   PARAM_NOTE_CGRAPH_SECTION_EDGE_THRESHOLD in the >> +   ".note.callgraph.text" section. */ >> +static void >> +dump_cgraph_profiles (void) >> +{ >> +  struct cgraph_node *node = cgraph_node (current_function_decl); >> +  struct cgraph_edge *e; >> +  struct cgraph_node *callee; >> + >> +  for (e = node->callees; e != NULL; e = e->next_callee) >> +    { >> +      if (e->count <= PARAM_VALUE (PARAM_NOTE_CGRAPH_SECTION_EDGE_THRESHOLD)) >> +        continue; >> +      callee = e->callee; >> +      fprintf (asm_out_file, "\t.string \"%s\"\n", >> +               IDENTIFIER_POINTER (decl_assembler_name (callee->decl))); >> +      fprintf (asm_out_file, "\t.string \"" HOST_WIDEST_INT_PRINT_DEC "\"\n", >> +               e->count); >> +    } >> +} >> + >>  /* Turn the RTL into assembly.  */ >>  static unsigned int >>  rest_of_handle_final (void) >>  { >>   rtx x; >>   const char *fnname; >> +  char *profile_fnname; >> +  unsigned int flags; >> >>   /* Get the function's name, as described by its RTL.  This may be >>      different from the DECL_NAME name used in the source file.  */ >> @@ -4387,6 +4411,21 @@ rest_of_handle_final (void) >>     targetm.asm_out.destructor (XEXP (DECL_RTL (current_function_decl), 0), >>                                decl_fini_priority_lookup >>                                  (current_function_decl)); >> + >> +  /* With -fcgraph-section, add ".note.callgraph.text" section for storing >> +     profiling information. */ >> +  if (flag_callgraph_profiles_sections >> +      && flag_profile_use >> +      && cgraph_node (current_function_decl) != NULL) >> +    { >> +      flags = SECTION_DEBUG; >> +      asprintf (&profile_fnname, ".note.callgraph.text.%s", fnname); >> +      switch_to_section (get_section (profile_fnname, flags, NULL)); >> +      fprintf (asm_out_file, "\t.string \"Function %s\"\n", fnname); >> +      dump_cgraph_profiles (); >> +      free (profile_fnname); >> +    } >> + >>   return 0; >>  } >> >> Index: common.opt >> =================================================================== >> --- common.opt  (revision 174789) >> +++ common.opt  (working copy) >> @@ -907,6 +907,10 @@ fcaller-saves >>  Common Report Var(flag_caller_saves) Optimization >>  Save registers around function calls >> >> +fcallgraph-profiles-sections >> +Common Report Var(flag_callgraph_profiles_sections) Init(0) >> +Generate .note.callgraph.text sections listing callees and edge counts. >> + >>  fcheck-data-deps >>  Common Report Var(flag_check_data_deps) >>  Compare the results of several data dependence analyzers. >> Index: params.def >> =================================================================== >> --- params.def  (revision 174789) >> +++ params.def  (working copy) >> @@ -1002,6 +1002,15 @@ DEFPARAM (PARAM_MVERSN_CLONE_CGRAPH_DEPTH, >>          "maximum length of the call graph path to be cloned " >>           "while doing multiversioning", >>          2, 0, 5) >> + >> +/* Only output those call graph edges in .note.callgraph.text sections >> +   whose count is greater than this value. */ >> +DEFPARAM (PARAM_NOTE_CGRAPH_SECTION_EDGE_THRESHOLD, >> +         "note-cgraph-section-edge-threshold", >> +         "minimum call graph edge count for inclusion in " >> +          ".note.callgraph.text section", >> +         0, 0, 0) >> + >>  /* >>  Local variables: >>  mode:c >> >> -- >> This patch is available for review at http://codereview.appspot.com/4591045 >> > 

[Sriraman, 2011-06-08 16:30:04]

On Wed, Jun 8, 2011 at 9:16 AM, Xinliang David Li <davidxl@google.com> wrote: > ok for google/main. Thanks, the patch is now committed. > > David > > On Wed, Jun 8, 2011 at 9:13 AM, Sriraman Tallam <tmsriram@google.com> wrote: >> +davidxl >> >> On Tue, Jun 7, 2011 at 7:05 PM, Sriraman Tallam <tmsriram@google.com> wrote: >>> Patch Description: >>> ================= >>> >>> I am working on a project to do global function layout in the linker where the linker reads the callgraph edge profile information, generated by FDO, and uses that to find a ordering of functions that will place functions calling each other frequently closer, like the Pettis-Hansen code ordering algorithm described in the paper "Profile-guided Code Poisitioning" in PLDI 1990. >>> >>> This patch adds a flag that allows the callgraph edge profile information to be stored .note sections called ".note.callgraph.text". The new compiler flag -fcallgraph-profiles-sections generates these sections and must be used along with -fprofile-use. I have added a PARAM to only output callgraph edges greater than a specified threshold. Once this is available, the linker can read these sections and generate a global callgraph which can be used to determine a global function ordering. >>> >>> I am adding plugin support in the gold linker to allow linker plugins to be able to read the contents of sections and also adding plugin hooks to specify a desired ordering of functions to the linker. The linker patch is available here : http://sourceware.org/ml/binutils/2011-03/msg00043.html. Once this is available, linker plugins can be used to determine the function layout, like the Pettis-Hansen algorithm, of the final binary. >>> >>> Example: The new .note.callgraph.text sections looks like this for a function foo that calls bar 100 times and zap 50 times: >>> **************************** >>> .section        .note.callgraph.text._Z3foov,"",@progbits >>>        .string "Function _Z3foov" >>>        .string "_Z3barv" >>>        .string "100" >>>        .string "_Z3zapv" >>>        .string "50" >>> *************************** >>> >>> For now, this is for google/main. I will re-submit for review to trunk along with data layout. >>> >>> Google ref 41940 >>> >>> 2011-06-07  Sriraman Tallam  <tmsriram@google.com> >>> >>>        * doc/invoke.texi: document option -fcallgraph-profiles-sections. >>>        * final.c  (dump_cgraph_profiles): New function. >>>        (rest_of_handle_final): Create new section '.note.callgraph.text' >>>        with compiler flag -fcallgraph-profiles-sections >>>        * common.opt: New option -fcallgraph-profiles-sections. >>>        * params.def (DEFPARAM): New param >>>        PARAM_NOTE_CGRAPH_SECTION_EDGE_THRESHOLD. >>> >>> Index: doc/invoke.texi >>> =================================================================== >>> --- doc/invoke.texi     (revision 174789) >>> +++ doc/invoke.texi     (working copy) >>> @@ -351,7 +351,7 @@ Objective-C and Objective-C++ Dialects}. >>>  -falign-labels[=@var{n}] -falign-loops[=@var{n}] -fassociative-math @gol >>>  -fauto-inc-dec -fbranch-probabilities -fbranch-target-load-optimize @gol >>>  -fbranch-target-load-optimize2 -fbtr-bb-exclusive -fcaller-saves @gol >>> --fcheck-data-deps -fclone-hot-version-paths @gol >>> +-fcallgraph-profiles-sections -fcheck-data-deps -fclone-hot-version-paths @gol >>>  -fcombine-stack-adjustments -fconserve-stack @gol >>>  -fcompare-elim -fcprop-registers -fcrossjumping @gol >>>  -fcse-follow-jumps -fcse-skip-blocks -fcx-fortran-rules @gol >>> @@ -8114,6 +8114,15 @@ Do not promote static functions with always inline >>>  @opindex fripa-verbose >>>  Enable printing of verbose information about dynamic inter-procedural optimizations. >>>  This is used in conjunction with the @option{-fripa}. >>> + >>> +@item -fcallgraph-profiles-sections >>> +@opindex fcallgraph-profiles-sections >>> +Emit call graph edge profile counts in .note.callgraph.text sections. This is >>> +used in conjunction with @option{-fprofile-use}. A new .note.callgraph.text >>> +section is created for each function. This section lists every callee and the >>> +number of times it is called. The params variable >>> +"note-cgraph-section-edge-threshold" can be used to only list edges above a >>> +certain threshold. >>>  @end table >>> >>>  The following options control compiler behavior regarding floating >>> Index: final.c >>> =================================================================== >>> --- final.c     (revision 174789) >>> +++ final.c     (working copy) >>> @@ -4321,13 +4321,37 @@ debug_free_queue (void) >>>       symbol_queue_size = 0; >>>     } >>>  } >>> - >>> + >>> +/* List the call graph profiled edges whise value is greater than >>> +   PARAM_NOTE_CGRAPH_SECTION_EDGE_THRESHOLD in the >>> +   ".note.callgraph.text" section. */ >>> +static void >>> +dump_cgraph_profiles (void) >>> +{ >>> +  struct cgraph_node *node = cgraph_node (current_function_decl); >>> +  struct cgraph_edge *e; >>> +  struct cgraph_node *callee; >>> + >>> +  for (e = node->callees; e != NULL; e = e->next_callee) >>> +    { >>> +      if (e->count <= PARAM_VALUE (PARAM_NOTE_CGRAPH_SECTION_EDGE_THRESHOLD)) >>> +        continue; >>> +      callee = e->callee; >>> +      fprintf (asm_out_file, "\t.string \"%s\"\n", >>> +               IDENTIFIER_POINTER (decl_assembler_name (callee->decl))); >>> +      fprintf (asm_out_file, "\t.string \"" HOST_WIDEST_INT_PRINT_DEC "\"\n", >>> +               e->count); >>> +    } >>> +} >>> + >>>  /* Turn the RTL into assembly.  */ >>>  static unsigned int >>>  rest_of_handle_final (void) >>>  { >>>   rtx x; >>>   const char *fnname; >>> +  char *profile_fnname; >>> +  unsigned int flags; >>> >>>   /* Get the function's name, as described by its RTL.  This may be >>>      different from the DECL_NAME name used in the source file.  */ >>> @@ -4387,6 +4411,21 @@ rest_of_handle_final (void) >>>     targetm.asm_out.destructor (XEXP (DECL_RTL (current_function_decl), 0), >>>                                decl_fini_priority_lookup >>>                                  (current_function_decl)); >>> + >>> +  /* With -fcgraph-section, add ".note.callgraph.text" section for storing >>> +     profiling information. */ >>> +  if (flag_callgraph_profiles_sections >>> +      && flag_profile_use >>> +      && cgraph_node (current_function_decl) != NULL) >>> +    { >>> +      flags = SECTION_DEBUG; >>> +      asprintf (&profile_fnname, ".note.callgraph.text.%s", fnname); >>> +      switch_to_section (get_section (profile_fnname, flags, NULL)); >>> +      fprintf (asm_out_file, "\t.string \"Function %s\"\n", fnname); >>> +      dump_cgraph_profiles (); >>> +      free (profile_fnname); >>> +    } >>> + >>>   return 0; >>>  } >>> >>> Index: common.opt >>> =================================================================== >>> --- common.opt  (revision 174789) >>> +++ common.opt  (working copy) >>> @@ -907,6 +907,10 @@ fcaller-saves >>>  Common Report Var(flag_caller_saves) Optimization >>>  Save registers around function calls >>> >>> +fcallgraph-profiles-sections >>> +Common Report Var(flag_callgraph_profiles_sections) Init(0) >>> +Generate .note.callgraph.text sections listing callees and edge counts. >>> + >>>  fcheck-data-deps >>>  Common Report Var(flag_check_data_deps) >>>  Compare the results of several data dependence analyzers. >>> Index: params.def >>> =================================================================== >>> --- params.def  (revision 174789) >>> +++ params.def  (working copy) >>> @@ -1002,6 +1002,15 @@ DEFPARAM (PARAM_MVERSN_CLONE_CGRAPH_DEPTH, >>>          "maximum length of the call graph path to be cloned " >>>           "while doing multiversioning", >>>          2, 0, 5) >>> + >>> +/* Only output those call graph edges in .note.callgraph.text sections >>> +   whose count is greater than this value. */ >>> +DEFPARAM (PARAM_NOTE_CGRAPH_SECTION_EDGE_THRESHOLD, >>> +         "note-cgraph-section-edge-threshold", >>> +         "minimum call graph edge count for inclusion in " >>> +          ".note.callgraph.text section", >>> +         0, 0, 0) >>> + >>>  /* >>>  Local variables: >>>  mode:c >>> >>> -- >>> This patch is available for review at http://codereview.appspot.com/4591045 >>> >> >