Add VEC_SERIES_EXPR and associated optab

Similarly to the VEC_DUPLICATE_EXPR, this patch adds a tree code
equivalent of the VEC_SERIES rtx code: VEC_SERIES_EXPR.

2017-12-16  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* doc/generic.texi (VEC_SERIES_EXPR): Document.
	* doc/md.texi (vec_series@var{m}): Document.
	* tree.def (VEC_SERIES_EXPR): New tree code.
	* tree.h (build_vec_series): Declare.
	* tree.c (build_vec_series): New function.
	* cfgexpand.c (expand_debug_expr): Handle VEC_SERIES_EXPR.
	* tree-pretty-print.c (dump_generic_node): Likewise.
	* gimple-pretty-print.c (dump_binary_rhs): Likewise.
	* tree-inline.c (estimate_operator_cost): Likewise.
	* expr.c (expand_expr_real_2): Likewise.
	* optabs-tree.c (optab_for_tree_code): Likewise.
	* tree-cfg.c (verify_gimple_assign_binary): Likewise.
	* fold-const.c (const_binop): Fold VEC_SERIES_EXPRs of constants.
	* expmed.c (make_tree): Handle VEC_SERIES.
	* optabs.def (vec_series_optab): New optab.
	* optabs.h (expand_vec_series_expr): Declare.
	* optabs.c (expand_vec_series_expr): New function.
	* tree-vect-generic.c (expand_vector_operations_1): Check that
	the operands also have vector type.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r255741

1 files changed, 24 insertions, 0 deletions

diff --git a/gcc/tree.c b/gcc/tree.c
index 8e0313c..b43a3fd 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -1797,6 +1797,30 @@ build_vector_from_val (tree vectype, tree sc)
     }
 }
 
+/* Build a vector series of type TYPE in which element I has the value
+   BASE + I * STEP.  The result is a constant if BASE and STEP are constant
+   and a VEC_SERIES_EXPR otherwise.  */
+
+tree
+build_vec_series (tree type, tree base, tree step)
+{
+  if (integer_zerop (step))
+    return build_vector_from_val (type, base);
+  if (TREE_CODE (base) == INTEGER_CST && TREE_CODE (step) == INTEGER_CST)
+    {
+      tree_vector_builder builder (type, 1, 3);
+      tree elt1 = wide_int_to_tree (TREE_TYPE (base),
+				    wi::to_wide (base) + wi::to_wide (step));
+      tree elt2 = wide_int_to_tree (TREE_TYPE (base),
+				    wi::to_wide (elt1) + wi::to_wide (step));
+      builder.quick_push (base);
+      builder.quick_push (elt1);
+      builder.quick_push (elt2);
+      return builder.build ();
+    }
+  return build2 (VEC_SERIES_EXPR, type, base, step);
+}
+
 /* Something has messed with the elements of CONSTRUCTOR C after it was built;
    calculate TREE_CONSTANT and TREE_SIDE_EFFECTS.  */