Move SLP nodes to an alloc-pool

This introduces a global alloc-pool for SLP nodes to reduce overhead
on SLP allocation churn which will get worse and to eventually release
SLP cycles which will retain a refcount of one and thus are never
freed at the moment.

2020-10-26  Richard Biener  <rguenther@suse.de>

	* tree-vectorizer.h (slp_tree_pool): Declare.
	(_slp_tree::operator new): Likewise.
	(_slp_tree::operator delete): Likewise.
	* tree-vectorizer.c (vectorize_loops): Allocate and free the
	slp_tree_pool.
	(pass_slp_vectorize::execute): Likewise.
	* tree-vect-slp.c (slp_tree_pool): Define.
	(_slp_tree::operator new): Likewise.
	(_slp_tree::operator delete): Likewise.

1 files changed, 9 insertions, 0 deletions

diff --git a/gcc/tree-vectorizer.c b/gcc/tree-vectorizer.c
index 778177a..0e08652 100644
--- a/gcc/tree-vectorizer.c
+++ b/gcc/tree-vectorizer.c
@@ -1170,6 +1170,8 @@ vectorize_loops (void)
   if (vect_loops_num <= 1)
     return 0;
 
+  slp_tree_pool = new object_allocator<_slp_tree> ("SLP nodes for vect");
+
   if (cfun->has_simduid_loops)
     note_simd_array_uses (&simd_array_to_simduid_htab);
 
@@ -1292,6 +1294,8 @@ vectorize_loops (void)
     shrink_simd_arrays (simd_array_to_simduid_htab, simduid_to_vf_htab);
   delete simduid_to_vf_htab;
   cfun->has_simduid_loops = false;
+  delete slp_tree_pool;
+  slp_tree_pool = NULL;
 
   if (num_vectorized_loops > 0)
     {
@@ -1427,8 +1431,13 @@ pass_slp_vectorize::execute (function *fun)
 	}
     }
 
+  slp_tree_pool = new object_allocator<_slp_tree> ("SLP nodes for slp");
+
   vect_slp_function (fun);
 
+  delete slp_tree_pool;
+  slp_tree_pool = NULL;
+
   if (!in_loop_pipeline)
     {
       scev_finalize ();