Disable aggregate walking in ipa code for optimize_debug

[Jan Hubicka <hubicka@ucw.cz>]

Martin,
with optimize_debug or when FRE is disabled propagating aggregates is
useless since we are not going to use them.  I think we should also
avoid working hard on the jump functions.
This patch disables it in ipa_load_from_param_agg, but I am not sure if
there are other ways ipa-prop can do the memory walk?

Bootstrapped/regtested x86_64. Makes sense?

Honza

	* ipa-fnsummary.c (vrp_will_run_p): Export.
	* ipa-fnsummary.h (vrp_will_run_p): Declare.
	* ipa-prop.c (ipa_load_from_parm_agg): Use it.
diff --git a/gcc/ipa-fnsummary.c b/gcc/ipa-fnsummary.c
index d96c8e9b03c..e5f43078c27 100644
--- a/gcc/ipa-fnsummary.c
+++ b/gcc/ipa-fnsummary.c
@@ -522,7 +522,7 @@ vrp_will_run_p (struct cgraph_node *node)
 
 /* Similarly about FRE.  */
 
-static bool
+bool
 fre_will_run_p (struct cgraph_node *node)
 {
   return (opt_for_fn (node->decl, optimize)
diff --git a/gcc/ipa-fnsummary.h b/gcc/ipa-fnsummary.h
index c6ddc9f3199..f4e1fd0cc86 100644
--- a/gcc/ipa-fnsummary.h
+++ b/gcc/ipa-fnsummary.h
@@ -371,6 +371,7 @@ void evaluate_properties_for_edge (struct cgraph_edge *e,
 void ipa_fnsummary_c_finalize (void);
 HOST_WIDE_INT ipa_get_stack_frame_offset (struct cgraph_node *node);
 void ipa_remove_from_growth_caches (struct cgraph_edge *edge);
+bool fre_will_run_p (struct cgraph_node *);
 
 /* Return true if EDGE is a cross module call.  */
 
diff --git a/gcc/ipa-prop.c b/gcc/ipa-prop.c
index 71ac0e104d2..7f654f3aea3 100644
--- a/gcc/ipa-prop.c
+++ b/gcc/ipa-prop.c
@@ -1091,6 +1091,12 @@ ipa_load_from_parm_agg (struct ipa_func_body_info *fbi,
   int index;
   HOST_WIDE_INT size;
   bool reverse;
+
+  /* Do not bother to do analysis when we are not doing propagation of
+     aggregates anyway.  */
+  if (!fre_will_run_p (cgraph_node::get (current_function_decl)))
+    return false;
+
   tree base = get_ref_base_and_extent_hwi (op, offset_p, &size, &reverse);
 
   if (!base)