[GOOGLE] Patch to fix AutoFDO LIPO performance regression

[Dehao Chen]

This patch fixup the call graph edge targets during AutoFDO pass, so
that when rebuilding call graph edges, it can find the correct callee.

Bootstrapped and passed regression test. Benchmark tests on-going.

Ok for google-4_8 branch?

Thanks,
Dehao

Index: gcc/Makefile.in
===================================================================
--- gcc/Makefile.in (revision 202725)
+++ gcc/Makefile.in (working copy)
@@ -2960,7 +2960,7 @@ coverage.o : coverage.c $(GCOV_IO_H) $(CONFIG_H) $
 auto-profile.o : auto-profile.c $(CONFIG_H) $(SYSTEM_H) $(FLAGS_H) \
    $(BASIC_BLOCK_H) $(DIAGNOSTIC_CORE_H) $(GCOV_IO_H) $(INPUT_H) profile.h \
    $(LANGHOOKS_H) $(OPTS_H) $(TREE_PASS_H) $(CGRAPH_H) $(GIMPLE_H)
value-prof.h \
-   $(COVERAGE_H) coretypes.h $(TREE_H) $(PARAMS_H) $(AUTO_PROFILE_H)
+   $(COVERAGE_H) coretypes.h $(TREE_H) $(PARAMS_H) l-ipo.h $(AUTO_PROFILE_H)
 cselib.o : cselib.c $(CONFIG_H) $(SYSTEM_H) coretypes.h dumpfile.h
$(TM_H) $(RTL_H) \
    $(REGS_H) hard-reg-set.h $(FLAGS_H) insn-config.h $(RECOG_H) \
    $(EMIT_RTL_H) $(DIAGNOSTIC_CORE_H) $(FUNCTION_H) \
Index: gcc/auto-profile.c
===================================================================
--- gcc/auto-profile.c (revision 202725)
+++ gcc/auto-profile.c (working copy)
@@ -46,6 +46,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "value-prof.h"
 #include "coverage.h"
 #include "params.h"
+#include "l-ipo.h"
 #include "auto-profile.h"

 /* The following routines implements AutoFDO optimization.
@@ -1290,6 +1291,13 @@ auto_profile (void)
   init_node_map ();
   profile_info = autofdo::afdo_profile_info;

+  cgraph_pre_profiling_inlining_done = true;
+  cgraph_process_module_scope_statics ();
+  /* Now perform link to allow cross module inlining.  */
+  cgraph_do_link ();
+  varpool_do_link ();
+  cgraph_unify_type_alias_sets ();
+
   FOR_EACH_FUNCTION (node)
     {
       if (!gimple_has_body_p (node->symbol.decl))
@@ -1301,6 +1309,21 @@ auto_profile (void)

       push_cfun (DECL_STRUCT_FUNCTION (node->symbol.decl));

+      if (L_IPO_COMP_MODE)
+        {
+  basic_block bb;
+  FOR_EACH_BB (bb)
+    {
+      gimple_stmt_iterator gsi;
+      for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+  gimple stmt = gsi_stmt (gsi);
+  if (is_gimple_call (stmt))
+    lipo_fixup_cgraph_edge_call_target (stmt);
+ }
+    }
+ }
+
       autofdo::afdo_annotate_cfg ();
       compute_function_frequency ();
       update_ssa (TODO_update_ssa);
@@ -1309,13 +1332,6 @@ auto_profile (void)
       pop_cfun ();
     }

-  cgraph_pre_profiling_inlining_done = true;
-  cgraph_process_module_scope_statics ();
-  /* Now perform link to allow cross module inlining.  */
-  cgraph_do_link ();
-  varpool_do_link ();
-  cgraph_unify_type_alias_sets ();
-
   return TODO_rebuild_cgraph_edges;
 }