[PATCH 06/12] ipa-cp: Leave removal of unused parameters to IPA-SRA

[Martin Jambor <mjambor@suse.cz>]

Hi,

looking at some benchmarks I have noticed many cases when IPA-CP
cloned a function for all contexts just because it knew that some
parameters were not used at all.  Then IPA-SRA looked at the function
and cloned it again to split another parameter or two.  The latter
pass is better equipped to detect when parameters can be altogether
removed and so the IPA-CP cloning was for no good reason.

This patch simply alters the IPA-CP not to do that in the situations
where IPA-SRA can (for nodes which can be made local).

Bootstrapped and tested on x86_64-linux.  OK for master?

Thanks,

Martin


gcc/ChangeLog:

2022-11-11  Martin Jambor  <mjambor@suse.cz>

	* ipa-cp.cc (estimate_local_effects): Do not clone potentionally local
	nodes for all contexts just to remove unused parameters.
---
 gcc/ipa-cp.cc | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/gcc/ipa-cp.cc b/gcc/ipa-cp.cc
index 02bd6a0fd1a..eb4474eb8b3 100644
--- a/gcc/ipa-cp.cc
+++ b/gcc/ipa-cp.cc
@@ -3722,7 +3722,10 @@ estimate_local_effects (struct cgraph_node *node)
 						    &removable_params_cost);
   int devirt_bonus = devirtualization_time_bonus (node, &avals);
   if (always_const || devirt_bonus
-      || (removable_params_cost && node->can_change_signature))
+      || (removable_params_cost
+	  && node->can_change_signature
+	  /* If IPA-SRA can do it, it can do it better.  */
+	  && !node->can_be_local_p ()))
     {
       struct caller_statistics stats;
       ipa_call_estimates estimates;
-- 
2.38.0