From: Richard Biener <rguenther@suse.de>
Date: Wed, 27 Mar 2024 10:37:16 +0000 (+0100)
Subject: tree-optimization/114057 - handle BB reduction remain defs as LIVE
X-Git-Tag: basepoints/gcc-15~452
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0b02da5b99e89347f5f8bf875ec8318f84adff18;p=thirdparty%2Fgcc.git

tree-optimization/114057 - handle BB reduction remain defs as LIVE

The following makes sure to record the scalars we add to the BB
reduction vectorization result as scalar uses for the purpose of
computing live lanes.  This restores vectorization in the
bondfree.c TU of 435.gromacs.

	PR tree-optimization/114057
	* tree-vect-slp.cc (vect_bb_slp_mark_live_stmts): Mark
	BB reduction remain defs as scalar uses.
---

diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index 23f9593191ad..f57684ca6856 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -6646,8 +6646,14 @@ vect_bb_slp_mark_live_stmts (bb_vec_info bb_vinfo)
   auto_vec<slp_tree> worklist;
 
   for (slp_instance instance : bb_vinfo->slp_instances)
-    if (!visited.add (SLP_INSTANCE_TREE (instance)))
-      worklist.safe_push (SLP_INSTANCE_TREE (instance));
+    {
+      if (SLP_INSTANCE_KIND (instance) == slp_inst_kind_bb_reduc)
+	for (tree op : SLP_INSTANCE_REMAIN_DEFS (instance))
+	  if (TREE_CODE (op) == SSA_NAME)
+	    scalar_use_map.put (op, 1);
+      if (!visited.add (SLP_INSTANCE_TREE (instance)))
+	worklist.safe_push (SLP_INSTANCE_TREE (instance));
+    }
 
   do
     {
@@ -6665,7 +6671,8 @@ vect_bb_slp_mark_live_stmts (bb_vec_info bb_vinfo)
 	    if (child && !visited.add (child))
 	      worklist.safe_push (child);
 	}
-    } while (!worklist.is_empty ());
+    }
+  while (!worklist.is_empty ());
 
   visited.empty ();