Re: [google] Patch to add compiler flag to dump callgraph edge profiles in special .note sections (issue4591045)
+davidxl
On Tue, Jun 7, 2011 at 7:05 PM, Sriraman Tallam tmsri...@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 tmsri...@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);
+ }
+}
+
/*
Re: [google] Patch to add compiler flag to dump callgraph edge profiles in special .note sections (issue4591045)
On Wed, Jun 8, 2011 at 9:16 AM, Xinliang David Li davi...@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 tmsri...@google.com wrote:
+davidxl
On Tue, Jun 7, 2011 at 7:05 PM, Sriraman Tallam tmsri...@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 tmsri...@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
[google] Patch to add compiler flag to dump callgraph edge profiles in special .note sections (issue4591045)
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 tmsri...@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
