Make more use of gimple-fold.h in tree-vect-loop.c

[Richard Sandiford]

This patch makes the vectoriser use the gimple-fold.h routines
in more cases, instead of vect_init_vector.  Later patches want
to use the same interface to handle variable-length vectors.

Tested on aarch64-linux-gnu, x86_64-linux-gnu and powerpc64le-linux-gnu.
OK to install?

Richard


2017-09-14  Richard Sandiford  <richard.sandif...@linaro.org>
            Alan Hayward  <alan.hayw...@arm.com>
            David Sherwood  <david.sherw...@arm.com>

gcc/
        * tree-vect-loop.c (vectorizable_induction): Use gimple_build instead
        of vect_init_vector.

Index: gcc/tree-vect-loop.c
===================================================================
--- gcc/tree-vect-loop.c        2017-09-14 11:26:37.599804415 +0100
+++ gcc/tree-vect-loop.c        2017-09-14 11:27:16.962234838 +0100
@@ -6839,18 +6839,21 @@ vectorizable_induction (gimple *phi,
     {
       /* iv_loop is the loop to be vectorized. Generate:
          vec_step = [VF*S, VF*S, VF*S, VF*S]  */
+      gimple_seq seq = NULL;
       if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (step_expr)))
        {
          expr = build_int_cst (integer_type_node, vf);
-         expr = fold_convert (TREE_TYPE (step_expr), expr);
+         expr = gimple_build (&seq, FLOAT_EXPR, TREE_TYPE (step_expr), expr);
        }
       else
        expr = build_int_cst (TREE_TYPE (step_expr), vf);
-      new_name = fold_build2 (MULT_EXPR, TREE_TYPE (step_expr),
-                             expr, step_expr);
-      if (TREE_CODE (step_expr) == SSA_NAME)
-       new_name = vect_init_vector (phi, new_name,
-                                    TREE_TYPE (step_expr), NULL);
+      new_name = gimple_build (&seq, MULT_EXPR, TREE_TYPE (step_expr),
+                              expr, step_expr);
+      if (seq)
+       {
+         new_bb = gsi_insert_seq_on_edge_immediate (pe, seq);
+         gcc_assert (!new_bb);
+       }
     }
 
   t = unshare_expr (new_name);
@@ -6899,6 +6902,7 @@ vectorizable_induction (gimple *phi,
 
   if (ncopies > 1)
     {
+      gimple_seq seq = NULL;
       stmt_vec_info prev_stmt_vinfo;
       /* FORNOW. This restriction should be relaxed.  */
       gcc_assert (!nested_in_vect_loop);
@@ -6907,15 +6911,18 @@ vectorizable_induction (gimple *phi,
       if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (step_expr)))
        {
          expr = build_int_cst (integer_type_node, nunits);
-         expr = fold_convert (TREE_TYPE (step_expr), expr);
+         expr = gimple_build (&seq, FLOAT_EXPR, TREE_TYPE (step_expr), expr);
        }
       else
        expr = build_int_cst (TREE_TYPE (step_expr), nunits);
-      new_name = fold_build2 (MULT_EXPR, TREE_TYPE (step_expr),
-                             expr, step_expr);
-      if (TREE_CODE (step_expr) == SSA_NAME)
-       new_name = vect_init_vector (phi, new_name,
-                                    TREE_TYPE (step_expr), NULL);
+      new_name = gimple_build (&seq, MULT_EXPR, TREE_TYPE (step_expr),
+                              expr, step_expr);
+      if (seq)
+       {
+         new_bb = gsi_insert_seq_on_edge_immediate (pe, seq);
+         gcc_assert (!new_bb);
+       }
+
       t = unshare_expr (new_name);
       gcc_assert (CONSTANT_CLASS_P (new_name)
                  || TREE_CODE (new_name) == SSA_NAME);