This patch makes two-operation SLP handle but reject variable-length
vectors. Adding support for this is a post-GCC8 thing.
2017-10-23 Richard Sandiford <richard.sandif...@linaro.org>
Alan Hayward <alan.hayw...@arm.com>
David Sherwood <david.sherw...@arm.com>
gcc/
* tree-vect-slp.c (vect_build_slp_tree_1): Handle polynomial
numbers of units.
(vect_schedule_slp_instance): Likewise.
Index: gcc/tree-vect-slp.c
===================================================================
--- gcc/tree-vect-slp.c 2017-10-23 17:22:42.827179461 +0100
+++ gcc/tree-vect-slp.c 2017-10-23 17:22:43.865071801 +0100
@@ -903,10 +903,19 @@ vect_build_slp_tree_1 (vec_info *vinfo,
/* If we allowed a two-operation SLP node verify the target can cope
with the permute we are going to use. */
+ poly_uint64 nunits = TYPE_VECTOR_SUBPARTS (vectype);
if (alt_stmt_code != ERROR_MARK
&& TREE_CODE_CLASS (alt_stmt_code) != tcc_reference)
{
- unsigned int count = TYPE_VECTOR_SUBPARTS (vectype);
+ unsigned HOST_WIDE_INT count;
+ if (!nunits.is_constant (&count))
+ {
+ if (dump_enabled_p ())
+ dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+ "Build SLP failed: different operations "
+ "not allowed with variable-length SLP.\n");
+ return false;
+ }
auto_vec_perm_indices sel (count);
for (i = 0; i < count; ++i)
{
@@ -3796,6 +3805,7 @@ vect_schedule_slp_instance (slp_tree nod
/* VECTYPE is the type of the destination. */
vectype = STMT_VINFO_VECTYPE (stmt_info);
+ poly_uint64 nunits = TYPE_VECTOR_SUBPARTS (vectype);
group_size = SLP_INSTANCE_GROUP_SIZE (instance);
if (!SLP_TREE_VEC_STMTS (node).exists ())
@@ -3858,13 +3868,16 @@ vect_schedule_slp_instance (slp_tree nod
unsigned k = 0, l;
for (j = 0; j < v0.length (); ++j)
{
- unsigned int nunits = TYPE_VECTOR_SUBPARTS (vectype);
- auto_vec<tree, 32> melts (nunits);
- for (l = 0; l < nunits; ++l)
+ /* Enforced by vect_build_slp_tree, which rejects variable-length
+ vectors for SLP_TREE_TWO_OPERATORS. */
+ unsigned int const_nunits = nunits.to_constant ();
+ auto_vec<tree, 32> melts (const_nunits);
+ for (l = 0; l < const_nunits; ++l)
{
if (k >= group_size)
k = 0;
- tree t = build_int_cst (meltype, mask[k++] * nunits + l);
+ tree t = build_int_cst (meltype,
+ mask[k++] * const_nunits + l);
melts.quick_push (t);
}
tmask = build_vector (mvectype, melts);
