middle-end: Refactor and expose some vectorizer helper functions.

This is a small refactoring which exposes some helper functions in the
vectorizer so they can be used in other places.

gcc/ChangeLog:

	* tree-vect-patterns.c (vect_mark_pattern_stmts): Remove static inline.
	* tree-vect-slp.c (vect_create_new_slp_node): Remove static and only
	set smts if valid.
	* tree-vectorizer.c (vec_info::add_pattern_stmt): New.
	(vec_info::set_vinfo_for_stmt): Optionally enforce read-only.
	* tree-vectorizer.h (struct _slp_tree): Use new types.
	(lane_permutation_t, lane_permutation_t): New.
	(vect_create_new_slp_node, vect_mark_pattern_stmts): New.

gcc/tree-vect-patterns.c

@@ -5281,7 +5281,7 @@ const unsigned int NUM_PATTERNS = ARRAY_SIZE (vect_vect_recog_func_ptrs);
 
 /* Mark statements that are involved in a pattern.  */
 
-static inline void
+void
 vect_mark_pattern_stmts (vec_info *vinfo,
 			 stmt_vec_info orig_stmt_info, gimple *pattern_stmt,
                          tree pattern_vectype)

gcc/tree-vect-slp.c

@@ -176,15 +176,18 @@ vect_free_slp_instance (slp_instance instance)
 
 /* Create an SLP node for SCALAR_STMTS.  */
 
-static slp_tree
+slp_tree
 vect_create_new_slp_node (slp_tree node,
 			  vec<stmt_vec_info> scalar_stmts, unsigned nops)
 {
   SLP_TREE_SCALAR_STMTS (node) = scalar_stmts;
   SLP_TREE_CHILDREN (node).create (nops);
   SLP_TREE_DEF_TYPE (node) = vect_internal_def;
-  SLP_TREE_REPRESENTATIVE (node) = scalar_stmts[0];
+  if (scalar_stmts.exists ())
-  SLP_TREE_LANES (node) = scalar_stmts.length ();
+    {
+      SLP_TREE_REPRESENTATIVE (node) = scalar_stmts[0];
+      SLP_TREE_LANES (node) = scalar_stmts.length ();
+    }
   return node;
 }
 

gcc/tree-vectorizer.c

@@ -525,6 +525,19 @@ vec_info::add_stmt (gimple *stmt)
   return res;
 }
 
+/* Record that STMT belongs to the vectorizable region.  Create a new
+   stmt_vec_info and mark VECINFO as being related and return the new
+   stmt_vec_info.  */
+
+stmt_vec_info
+vec_info::add_pattern_stmt (gimple *stmt, stmt_vec_info stmt_info)
+{
+  stmt_vec_info res = new_stmt_vec_info (stmt);
+  set_vinfo_for_stmt (stmt, res, false);
+  STMT_VINFO_RELATED_STMT (res) = stmt_info;
+  return res;
+}
+
 /* If STMT has an associated stmt_vec_info, return that vec_info, otherwise
    return null.  It is safe to call this function on any statement, even if
    it might not be part of the vectorizable region.  */
@@ -702,12 +715,12 @@ vec_info::new_stmt_vec_info (gimple *stmt)
 /* Associate STMT with INFO.  */
 
 void
-vec_info::set_vinfo_for_stmt (gimple *stmt, stmt_vec_info info)
+vec_info::set_vinfo_for_stmt (gimple *stmt, stmt_vec_info info, bool check_ro)
 {
   unsigned int uid = gimple_uid (stmt);
   if (uid == 0)
     {
-      gcc_assert (!stmt_vec_info_ro);
+      gcc_assert (!check_ro || !stmt_vec_info_ro);
       gcc_checking_assert (info);
       uid = stmt_vec_infos.length () + 1;
       gimple_set_uid (stmt, uid);

gcc/tree-vectorizer.h

@@ -114,6 +114,8 @@ typedef hash_map<tree_operand_hash,
   SLP
  ************************************************************************/
 typedef struct _slp_tree *slp_tree;
+typedef vec<std::pair<unsigned, unsigned> > lane_permutation_t;
+typedef vec<unsigned> load_permutation_t;
 
 /* A computation tree of an SLP instance.  Each node corresponds to a group of
    stmts to be packed in a SIMD stmt.  */
@@ -134,11 +136,11 @@ struct _slp_tree {
 
   /* Load permutation relative to the stores, NULL if there is no
      permutation.  */
-  vec<unsigned> load_permutation;
+  load_permutation_t load_permutation;
   /* Lane permutation of the operands scalar lanes encoded as pairs
      of { operand number, lane number }.  The number of elements
      denotes the number of output lanes.  */
-  vec<std::pair<unsigned, unsigned> > lane_permutation;
+  lane_permutation_t lane_permutation;
 
   tree vectype;
   /* Vectorized stmt/s.  */
@@ -362,6 +364,7 @@ public:
   ~vec_info ();
 
   stmt_vec_info add_stmt (gimple *);
+  stmt_vec_info add_pattern_stmt (gimple *, stmt_vec_info);
   stmt_vec_info lookup_stmt (gimple *);
   stmt_vec_info lookup_def (tree);
   stmt_vec_info lookup_single_use (tree);
@@ -407,7 +410,7 @@ public:
 
 private:
   stmt_vec_info new_stmt_vec_info (gimple *stmt);
-  void set_vinfo_for_stmt (gimple *, stmt_vec_info);
+  void set_vinfo_for_stmt (gimple *, stmt_vec_info, bool = true);
   void free_stmt_vec_infos ();
   void free_stmt_vec_info (stmt_vec_info);
 };
@@ -2005,8 +2008,12 @@ extern void duplicate_and_interleave (vec_info *, gimple_seq *, tree,
 				      vec<tree>, unsigned int, vec<tree> &);
 extern int vect_get_place_in_interleaving_chain (stmt_vec_info, stmt_vec_info);
 extern bool vect_update_shared_vectype (stmt_vec_info, tree);
+extern slp_tree vect_create_new_slp_node (vec<stmt_vec_info>, unsigned);
 
 /* In tree-vect-patterns.c.  */
+extern void
+vect_mark_pattern_stmts (vec_info *, stmt_vec_info, gimple *, tree);
+
 /* Pattern recognition functions.
    Additional pattern recognition functions can (and will) be added
    in the future.  */