[GOOGLE] Fix uninitialized memory in AutoFDO implementation

[Dehao Chen]

This patch fixes an uninitialized memory error and a hashtable
comparison bug in AutoFDO.

Bootstrapped and passed regression test.

OK for google branches?

Thanks,
Dehao

Index: gcc/auto-profile.c
===================================================================
--- gcc/auto-profile.c (revision 199461)
+++ gcc/auto-profile.c (working copy)
@@ -310,10 +310,11 @@ afdo_stack_eq (const void *p, const void *q)
       if (s2->callee_name != NULL)
  return 0;
     }
-  else if (s2->callee_name != NULL
-   && strcmp (afdo_get_bfd_name (s1->callee_name),
-      afdo_get_bfd_name (s2->callee_name)))
+  else if (s2->callee_name == NULL)
     return 0;
+  else if (strcmp (afdo_get_bfd_name (s1->callee_name),
+   afdo_get_bfd_name (s2->callee_name)))
+    return 0;

   i = afdo_get_original_name_size (s1->func_name);
   if (i != afdo_get_original_name_size (s2->func_name))
@@ -1214,6 +1215,8 @@ process_auto_profile (void)
       new_stack->num_inst = 0;
       new_stack->count = 0;
       new_stack->max_count = 0;
+      new_stack->hist_size = 0;
+      new_stack->hist = NULL;
       stack_slot = (struct gcov_stack **)
   htab_find_slot (stack_htab, new_stack, INSERT);
       if (!*stack_slot)