Fix SLP permute propagation error

This fixes SLP permute propagation to not propagate across operations
that have different semantics on different lanes like for example
the recently added COMPLEX_ADD_ROT90.

2021-06-24  Richard Biener  <rguenther@suse.de>

	* tree-vect-slp.c (vect_optimize_slp): Do not propagate
	across operations that have different semantics on different
	lanes.

diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c
index 29db56e..69ee8fa 100644 (file)
--- a/gcc/tree-vect-slp.c
+++ b/gcc/tree-vect-slp.c
@@ -3680,18 +3680,34 @@ vect_optimize_slp (vec_info *vinfo)
        {
          int idx = ipo[i-1];
          slp_tree node = vertices[idx].node;
-         /* For leafs there's nothing to do - we've seeded permutes
-            on those above.  */
-         if (SLP_TREE_DEF_TYPE (node) != vect_internal_def)
+
+         /* Handle externals and constants optimistically throughout the
+            iteration.  */
+         if (SLP_TREE_DEF_TYPE (node) == vect_external_def
+             || SLP_TREE_DEF_TYPE (node) == vect_constant_def)
            continue;
 
          vertices[idx].visited = 1;
 
-         /* We cannot move a permute across a store.  */
-         if (STMT_VINFO_DATA_REF (SLP_TREE_REPRESENTATIVE (node))
-             && DR_IS_WRITE
-                  (STMT_VINFO_DATA_REF (SLP_TREE_REPRESENTATIVE (node))))
+         /* We do not handle stores with a permutation.  */
+         stmt_vec_info rep = SLP_TREE_REPRESENTATIVE (node);
+         if (STMT_VINFO_DATA_REF (rep)
+             && DR_IS_WRITE (STMT_VINFO_DATA_REF (rep)))
            continue;
+         /* We cannot move a permute across an operation that is
+            not independent on lanes.  Note this is an explicit
+            negative list since that's much shorter than the respective
+            positive one but it's critical to keep maintaining it.  */
+         if (is_gimple_call (STMT_VINFO_STMT (rep)))
+           switch (gimple_call_combined_fn (STMT_VINFO_STMT (rep)))
+             {
+             case CFN_COMPLEX_ADD_ROT90:
+             case CFN_COMPLEX_ADD_ROT270:
+             case CFN_COMPLEX_MUL:
+             case CFN_COMPLEX_MUL_CONJ:
+               continue;
+             default:;
+             }
 
          int perm = -1;
          for (graph_edge *succ = slpg->vertices[idx].succ;