[PATCH] Create VECTOR_CST instead of CONSTRUCTORs where possible in the vectorizer (PR tree-optimization/33993)

[Jakub Jelinek <jakub at redhat dot com>]

Hi!

On sparc64-linux gcc ICEs on the attached testcase with -O3, because stmt
verification doesn't like <VIEW_CONVERT_EXPR <CONSTRUCTOR <...>>, but
requires a CONSTANT_CLASS_P or is_gimple_lvalue inside of
handled_component_p.  While that verification should be probably to allow
CONSTRUCTORs inside of VIEW_CONVERT_EXPR (guess no other
handled_component_p codes though), or at least some CONSTRUCTORs (which?
is_gimple_min_invariant ones, or only TREE_CONSTANT ones, only vector
ones or something else), this exact problem is because vectorizer is lazy
and creates CONSTRUCTORs even when VECTOR_CSTs should be used instead
(if these were gimplified, the gimplifier would change them to VECTOR_CSTs,
but they are not and also it would be wasteful to create CONSTRUCTORs only
to create VECTOR_CSTs from them immediately afterwards).

In vect_get_constant_vectors the parts can actually be sometimes constants,
sometimes something else, in the latter hunks I'm fairly certain only
constants can be seen among the parts - step_expr is an INTEGER_CST
(otherwise vect_is_simple_iv_evolution would return false and we'd fail
the assertion after it) and in some cases it is multiplied by another
INTEGER_CST.

Regtested on x86_64-linux, tested on the testcase on sparc64-linux.
Ok for trunk?

2007-11-05  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/33993
	* tree-vect-transform.c (vect_get_constant_vectors): Use build_vector
	rather than build_constructor_from_list if all list values are
	constants.
	(get_initial_def_for_induction): Use build_vector instead of
	build_constructor_from_list.

	* gcc.c-torture/compile/20071105-1.c: New test.

--- gcc/tree-vect-transform.c.jj	2007-11-05 09:05:44.000000000 +0100
+++ gcc/tree-vect-transform.c	2007-11-05 11:41:14.000000000 +0100
@@ -1318,6 +1318,7 @@ vect_get_constant_vectors (slp_tree slp_
   bool is_store = false;
   unsigned int number_of_vectors = SLP_TREE_NUMBER_OF_VEC_STMTS (slp_node);
   VEC (tree, heap) *voprnds = VEC_alloc (tree, heap, number_of_vectors);
+  bool constant_p;
 
   if (STMT_VINFO_DATA_REF (stmt_vinfo))
     is_store = true;
@@ -1341,6 +1342,7 @@ vect_get_constant_vectors (slp_tree slp_
   number_of_copies = least_common_multiple (nunits, group_size) / group_size;
 
   number_of_places_left_in_vector = nunits;
+  constant_p = true;
   for (j = 0; j < number_of_copies; j++)
     {
       for (i = group_size - 1; VEC_iterate (tree, stmts, i, stmt); i--)
@@ -1350,6 +1352,8 @@ vect_get_constant_vectors (slp_tree slp_
 	    op = operation;
 	  else
 	    op = TREE_OPERAND (operation, op_num);
+	  if (!CONSTANT_CLASS_P (op))
+	    constant_p = false;
 
           /* Create 'vect_ = {op0,op1,...,opn}'.  */
           t = tree_cons (NULL_TREE, op, t);
@@ -1362,7 +1366,11 @@ vect_get_constant_vectors (slp_tree slp_
 
 	      vector_type = get_vectype_for_scalar_type (TREE_TYPE (op));
               gcc_assert (vector_type);
-              vec_cst = build_constructor_from_list (vector_type, t);
+	      if (constant_p)
+		vec_cst = build_vector (vector_type, t);
+	      else
+		vec_cst = build_constructor_from_list (vector_type, t);
+	      constant_p = true;
               VEC_quick_push (tree, voprnds,
                               vect_init_vector (stmt, vec_cst, vector_type,
 						NULL));
@@ -1617,7 +1625,8 @@ get_initial_def_for_induction (tree iv_p
   t = NULL_TREE;
   for (i = 0; i < nunits; i++)
     t = tree_cons (NULL_TREE, unshare_expr (new_name), t);
-  vec = build_constructor_from_list (vectype, t);
+  gcc_assert (CONSTANT_CLASS_P (new_name));
+  vec = build_vector (vectype, t);
   vec_step = vect_init_vector (iv_phi, vec, vectype, NULL);
 
 
@@ -1673,7 +1682,8 @@ get_initial_def_for_induction (tree iv_p
       t = NULL_TREE;
       for (i = 0; i < nunits; i++)
 	t = tree_cons (NULL_TREE, unshare_expr (new_name), t);
-      vec = build_constructor_from_list (vectype, t);
+      gcc_assert (CONSTANT_CLASS_P (new_name));
+      vec = build_vector (vectype, t);
       vec_step = vect_init_vector (iv_phi, vec, vectype, NULL);
 
       vec_def = induc_def;
--- gcc/testsuite/gcc.c-torture/compile/20071105-1.c.jj	2007-11-05 12:54:14.000000000 +0100
+++ gcc/testsuite/gcc.c-torture/compile/20071105-1.c	2007-11-05 12:53:47.000000000 +0100
@@ -0,0 +1,11 @@
+/* PR tree-optimization/33993 */
+/* Testcase by Martin Michlmayr <tbm@cyrius.com> */
+
+void
+init_full (char *array, int ny)
+{
+  int j;
+  char acc = 128;
+  for (j = 0; j < ny; j++)
+    *array++ = acc++;
+}

	Jakub