poly_int: vect_get_constant_vectors

For now, vect_get_constant_vectors can only cope with constant-length
vectors, although a patch after the main SVE submission relaxes this.
This patch adds an appropriate guard for variable-length vectors.
The TYPE_VECTOR_SUBPARTS use in vect_get_constant_vectors will then
have a to_constant call when TYPE_VECTOR_SUBPARTS becomes a poly_int.

2018-01-03  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* tree-vect-slp.c (vect_get_and_check_slp_defs): Reject
	constant and extern definitions for variable-length vectors.
	(vect_get_constant_vectors): Note that the number of units
	is known to be constant.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>
From-SVN: r256140

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 87c70af60f2eba7a142326cdfe2da1947550b5c8..c25eb15242cb6f84e06e040df3fb02d48bac7b46 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2018-01-03  Richard Sandiford  <richard.sandiford@linaro.org>
+           Alan Hayward  <alan.hayward@arm.com>
+           David Sherwood  <david.sherwood@arm.com>
+
+       * tree-vect-slp.c (vect_get_and_check_slp_defs): Reject
+       constant and extern definitions for variable-length vectors.
+       (vect_get_constant_vectors): Note that the number of units
+       is known to be constant.
+
 2018-01-03  Richard Sandiford  <richard.sandiford@linaro.org>
            Alan Hayward  <alan.hayward@arm.com>
            David Sherwood  <david.sherwood@arm.com>

diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c
index 7d8c3522050f1f438eb3f7df5f83231c3ae44091..4aa816f7886305e103c7807219003ce38613c5f3 100644 (file)
--- a/gcc/tree-vect-slp.c
+++ b/gcc/tree-vect-slp.c
@@ -405,6 +405,20 @@ again:
        {
        case vect_constant_def:
        case vect_external_def:
+         /* We must already have set a vector size by now.  */
+         gcc_checking_assert (maybe_ne (current_vector_size, 0U));
+         if (!current_vector_size.is_constant ())
+           {
+             if (dump_enabled_p ())
+               {
+                 dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+                                  "Build SLP failed: invalid type of def "
+                                  "for variable-length SLP ");
+                 dump_generic_expr (MSG_MISSED_OPTIMIZATION, TDF_SLIM, oprnd);
+                 dump_printf (MSG_MISSED_OPTIMIZATION, "\n");
+               }
+             return -1;
+           }
          break;
 
        case vect_reduction_def:
@@ -3233,6 +3247,7 @@ vect_get_constant_vectors (tree op, slp_tree slp_node,
       = build_same_sized_truth_vector_type (STMT_VINFO_VECTYPE (stmt_vinfo));
   else
     vector_type = get_vectype_for_scalar_type (TREE_TYPE (op));
+  /* Enforced by vect_get_and_check_slp_defs.  */
   nunits = TYPE_VECTOR_SUBPARTS (vector_type);
 
   if (STMT_VINFO_DATA_REF (stmt_vinfo))