[PATCH 5/5] RISC-V: tree-optimization/65518 - extend fix to SLP

[PATCH 5/5] RISC-V: tree-optimization/65518 - extend fix to SLP

[Richard Biener]

This extends the PR65518 workaround to also apply for single-lane SLP.

	* tree-vect-stmts.cc (get_group_load_store_type): For SLP also
	check for the PR65518 single-element interleaving case as done in
	vect_grouped_load_supported.
---
 gcc/tree-vect-stmts.cc | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index 1c30a0388ca..a01099d3456 100644
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -2154,6 +2154,23 @@ get_group_load_store_type (vec_info *vinfo, stmt_vec_info stmt_info,
 		}
 	      overrun_p = true;
 	    }
+
+	  /* If this is single-element interleaving with an element
+	     distance that leaves unused vector loads around punt - we
+	     at least create very sub-optimal code in that case (and
+	     blow up memory, see PR65518).  */
+	  if (loop_vinfo
+	      && *memory_access_type == VMAT_CONTIGUOUS
+	      && SLP_TREE_LOAD_PERMUTATION (slp_node).exists ()
+	      && single_element_p
+	      && maybe_gt (group_size, TYPE_VECTOR_SUBPARTS (vectype)))
+	    {
+	      if (dump_enabled_p ())
+		dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+				 "single-element interleaving not supported "
+				 "for not adjacent vector loads\n");
+	      return false;
+	    }
 	}
     }
   else
-- 
2.35.3