tree-optimization/117556 - SLP of live stmts from load-lanes

The following fixes SLP live lane generation for load-lanes which
fails to analyze for gcc.dg/vect/vect-live-slp-3.c because the
VLA division doesn't work out but it would also wrongly use the
transposed vector defs I think.  The following properly disables
the actual load-lanes SLP node from live lane processing and instead
relies on the SLP permute node representing the live lane where we
can use extract-last to extract the last lane.  This also fixes
the reported Ada miscompile.

	PR tree-optimization/117556
	PR tree-optimization/117553
	* tree-vect-stmts.cc (vect_analyze_stmt): Do not analyze
	the SLP load-lanes node for live lanes, but only the
	permute node.
	(vect_transform_stmt): Likewise for the transform.

	* gcc.dg/vect/vect-live-slp-3.c: Expect us to SLP even for
	VLA vectors (in single-lane mode).

diff --git a/gcc/testsuite/gcc.dg/vect/vect-live-slp-3.c b/gcc/testsuite/gcc.dg/vect/vect-live-slp-3.c
index e37822406751b99b3e5e7b33722dcb1912483345..3caeea71ad7f8858e20a1551b8a0eef573366e96 100644 (file)
--- a/gcc/testsuite/gcc.dg/vect/vect-live-slp-3.c
+++ b/gcc/testsuite/gcc.dg/vect/vect-live-slp-3.c
@@ -73,5 +73,5 @@ main (void)
 }
 
 /* { dg-final { scan-tree-dump-times "vectorized 1 loops" 4 "vect" } } */
-/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 4 "vect" { xfail vect_variable_length } } } */
+/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 4 "vect" } } */
 /* { dg-final { scan-tree-dump-times "vec_stmt_relevant_p: stmt live but not relevant" 4 "vect" } } */

diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index f77a223b0c4fc8e576de459c3c1163a31add1cea..2b3dd52a607d6e294418e04b804bd94fff7b848a 100644 (file)
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -13594,6 +13594,7 @@ vect_analyze_stmt (vec_info *vinfo,
   if (!bb_vinfo
       && STMT_VINFO_TYPE (stmt_info) != reduc_vec_info_type
       && STMT_VINFO_TYPE (stmt_info) != lc_phi_info_type
+      && (!node || !node->ldst_lanes || SLP_TREE_CODE (node) == VEC_PERM_EXPR)
       && !can_vectorize_live_stmts (as_a <loop_vec_info> (vinfo),
                                    stmt_info, node, node_instance,
                                    false, cost_vec))
@@ -13756,7 +13757,10 @@ vect_transform_stmt (vec_info *vinfo,
   if (!slp_node && vec_stmt)
     gcc_assert (STMT_VINFO_VEC_STMTS (stmt_info).exists ());
 
-  if (STMT_VINFO_TYPE (stmt_info) != store_vec_info_type)
+  if (STMT_VINFO_TYPE (stmt_info) != store_vec_info_type
+      && (!slp_node
+         || !slp_node->ldst_lanes
+         || SLP_TREE_CODE (slp_node) == VEC_PERM_EXPR))
     {
       /* Handle stmts whose DEF is used outside the loop-nest that is
         being vectorized.  */