From: Tamar Christina <tamar.christina@arm.com>
Date: Thu, 14 Jan 2021 20:49:55 +0000 (+0000)
Subject: slp: elide intermediate nodes for complex add and avoid truncate
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=fe70119531395c8105b098bfa915c003c78be038;p=gcc.git

slp: elide intermediate nodes for complex add and avoid truncate

This applies the same feedback received for MUL and the rest to
ADD which was already committed.  In short it elides the intermediate
nodes vec and avoids the use of truncate on the SLP child.

gcc/ChangeLog:

	* tree-vect-slp-patterns.c (complex_add_pattern::build):
	Elide nodes.
---

diff --git a/gcc/tree-vect-slp-patterns.c b/gcc/tree-vect-slp-patterns.c
index 3903cdb1169..c4fa269baa3 100644
--- a/gcc/tree-vect-slp-patterns.c
+++ b/gcc/tree-vect-slp-patterns.c
@@ -627,23 +627,21 @@ class complex_add_pattern : public complex_pattern
 void
 complex_add_pattern::build (vec_info *vinfo)
 {
-  auto_vec<slp_tree> nodes;
+  SLP_TREE_CHILDREN (*this->m_node).reserve_exact (2);
+
   slp_tree node = this->m_ops[0];
   vec<slp_tree> children = SLP_TREE_CHILDREN (node);
 
   /* First re-arrange the children.  */
-  nodes.create (children.length ());
-  nodes.quick_push (children[0]);
-  nodes.quick_push (vect_build_swap_evenodd_node (children[1]));
+  SLP_TREE_CHILDREN (*this->m_node)[0] = children[0];
+  SLP_TREE_CHILDREN (*this->m_node)[1] =
+    vect_build_swap_evenodd_node (children[1]);
 
-  SLP_TREE_REF_COUNT (nodes[0])++;
-  SLP_TREE_REF_COUNT (nodes[1])++;
+  SLP_TREE_REF_COUNT (SLP_TREE_CHILDREN (*this->m_node)[0])++;
+  SLP_TREE_REF_COUNT (SLP_TREE_CHILDREN (*this->m_node)[1])++;
   vect_free_slp_tree (this->m_ops[0]);
   vect_free_slp_tree (this->m_ops[1]);
 
-  SLP_TREE_CHILDREN (*this->m_node).truncate (0);
-  SLP_TREE_CHILDREN (*this->m_node).safe_splice (nodes);
-
   complex_pattern::build (vinfo);
 }