Forgot to mention the changes:
* cgraphbuild.c (remove_cgraph_callee_edges): Preserve callee edges if
callgraph profiles are needed.
* final.c (rest_of_handle_final): Rename .note.callgraph sections as
.gnu.callgraph sections.
* tree-optimize.c (gate_all_optimizations): Set
cgraph_callee_edges_final_cleanup to true.
(cgraph_callee_edges_final_cleanup): New global variable.
* g++.dg/tree-prof/callgraph-profiles.C: New test.
On Thu, Sep 22, 2011 at 4:01 PM, Sriraman Tallam <tmsri...@google.com> wrote:
> This patch preserves cgraph callee edges till pass_final if callgraph
> edge profiles sections are requested. It also renames callgraph edge
> profile sections to be .gnu.callgraph instead of .note.callgraph
>
>
> Index: cgraphbuild.c
> ===================================================================
> --- cgraphbuild.c (revision 179098)
> +++ cgraphbuild.c (working copy)
> @@ -697,10 +697,18 @@ struct gimple_opt_pass pass_rebuild_cgraph_edges =
> }
> };
>
> +/* Defined in tree-optimize.c */
> +extern bool cgraph_callee_edges_final_cleanup;
>
> static unsigned int
> remove_cgraph_callee_edges (void)
> {
> + /* The -fcallgraph-profiles-sections flag needs the call-graph preserved
> + till pass_final. */
> + if (cgraph_callee_edges_final_cleanup
> + && flag_callgraph_profiles_sections)
> + return 0;
> +
> cgraph_node_remove_callees (cgraph_node (current_function_decl));
> return 0;
> }
> Index: final.c
> ===================================================================
> --- final.c (revision 179098)
> +++ final.c (working copy)
> @@ -4425,10 +4425,11 @@ rest_of_handle_final (void)
> profiling information. */
> if (flag_callgraph_profiles_sections
> && flag_profile_use
> - && cgraph_node (current_function_decl) != NULL)
> + && cgraph_node (current_function_decl) != NULL
> + && (cgraph_node (current_function_decl))->callees != NULL)
> {
> flags = SECTION_DEBUG;
> - asprintf (&profile_fnname, ".note.callgraph.text.%s", fnname);
> + asprintf (&profile_fnname, ".gnu.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 ();
> Index: testsuite/g++.dg/tree-prof/callgraph-profiles.C
> ===================================================================
> --- testsuite/g++.dg/tree-prof/callgraph-profiles.C (revision 0)
> +++ testsuite/g++.dg/tree-prof/callgraph-profiles.C (revision 0)
> @@ -0,0 +1,29 @@
> +/* Verify if call-graph profile sections are created
> + with -fcallgraph-profiles-sections. */
> +/* { dg-options "-O2 -fcallgraph-profiles-sections -ffunction-sections
> --save-temps" } */
> +
> +int __attribute__ ((noinline))
> +foo ()
> +{
> + return 1;
> +}
> +
> +int __attribute__ ((noinline))
> +bar ()
> +{
> + return 0;
> +}
> +
> +int main ()
> +{
> + int sum;
> + for (int i = 0; i< 1000; i++)
> + {
> + sum = foo () + bar();
> + }
> + return sum * bar ();
> +}
> +
> +/* { dg-final-use { scan-assembler "\.gnu\.callgraph\.text\.main" } } */
> +/* { dg-final-use { scan-assembler "\.string \"1000\"" } } */
> +/* { dg-final-use { cleanup-saved-temps } } */
> Index: tree-optimize.c
> ===================================================================
> --- tree-optimize.c (revision 179098)
> +++ tree-optimize.c (working copy)
> @@ -48,11 +48,17 @@ along with GCC; see the file COPYING3. If not see
> #include "plugin.h"
> #include "regset.h" /* FIXME: For reg_obstack. */
>
> +/* Decides if the cgraph callee edges are being cleaned up for the
> + last time. */
> +bool cgraph_callee_edges_final_cleanup = false;
> +
> /* Gate: execute, or not, all of the non-trivial optimizations. */
>
> static bool
> gate_all_optimizations (void)
> {
> + /* The cgraph callee edges can be cleaned up for the last time. */
> + cgraph_callee_edges_final_cleanup = true;
> return (optimize >= 1
> /* Don't bother doing anything if the program has errors.
> We have to pass down the queue if we already went into SSA */
>
> --
> This patch is available for review at http://codereview.appspot.com/5101042
>
