Avoid SSA copies from vect_add_slp_permutation

In the past we needed a stmt_vec_info for all vector defs.  Not
anymore.

	* tree-vect-slp.cc (vect_add_slp_permutation): We no longer
	need a copy when the extraction is readily available.
	(vect_schedule_slp_node): Handle default defs or constants
	in vector defs.

diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index 8057a10ff807f58c7b8a9611f5f34de4457c5db4..e350d8040f5ec201a8fe5fc5f6c2fa6b465f2978 100644 (file)
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -11365,7 +11365,6 @@ vect_add_slp_permutation (vec_info *vinfo, gimple_stmt_iterator *gsi,
       first_def = gimple_assign_lhs (conv_stmt);
     }
   gassign *perm_stmt;
-  tree perm_dest = make_ssa_name (vectype);
   if (mask_vec)
     {
       if (operand_equal_p (TYPE_SIZE (TREE_TYPE (first_def)),
@@ -11379,6 +11378,7 @@ vect_add_slp_permutation (vec_info *vinfo, gimple_stmt_iterator *gsi,
          vect_finish_stmt_generation (vinfo, NULL, conv_stmt, gsi);
          second_def = gimple_assign_lhs (conv_stmt);
        }
+      tree perm_dest = make_ssa_name (vectype);
       perm_stmt = gimple_build_assign (perm_dest, VEC_PERM_EXPR,
                                       first_def, second_def,
                                       mask_vec);
@@ -11396,6 +11396,7 @@ vect_add_slp_permutation (vec_info *vinfo, gimple_stmt_iterator *gsi,
        {
          /* For identity permutes we still need to handle the case
             of offsetted extracts or concats.  */
+         tree perm_dest = make_ssa_name (vectype);
          unsigned HOST_WIDE_INT c;
          if (known_le (TYPE_VECTOR_SUBPARTS (vectype), def_nunits))
            {
@@ -11420,9 +11421,9 @@ vect_add_slp_permutation (vec_info *vinfo, gimple_stmt_iterator *gsi,
        }
       else
        {
-         /* We need a copy here in case the def was external.  */
          gcc_assert (known_eq (eltno, 0U));
-         perm_stmt = gimple_build_assign (perm_dest, def);
+         node->push_vec_def (def);
+         return;
        }
     }
   vect_finish_stmt_generation (vinfo, NULL, perm_stmt, gsi);
@@ -11929,17 +11930,19 @@ vect_schedule_slp_node (vec_info *vinfo,
            unsigned j;
            tree vdef;
            FOR_EACH_VEC_ELT (SLP_TREE_VEC_DEFS (child), j, vdef)
-             {
-               gimple *vstmt = SSA_NAME_DEF_STMT (vdef);
-               if (!last_stmt)
-                 last_stmt = vstmt;
-               else if (vect_stmt_dominates_stmt_p (last_stmt, vstmt))
-                 last_stmt = vstmt;
-               else if (vect_stmt_dominates_stmt_p (vstmt, last_stmt))
-                 ;
-               else
-                 gcc_unreachable ();
-             }
+             if (TREE_CODE (vdef) == SSA_NAME
+                 && !SSA_NAME_IS_DEFAULT_DEF (vdef))
+               {
+                 gimple *vstmt = SSA_NAME_DEF_STMT (vdef);
+                 if (!last_stmt)
+                   last_stmt = vstmt;
+                 else if (vect_stmt_dominates_stmt_p (last_stmt, vstmt))
+                   last_stmt = vstmt;
+                 else if (vect_stmt_dominates_stmt_p (vstmt, last_stmt))
+                   ;
+                 else
+                   gcc_unreachable ();
+               }
          }
        else if (!SLP_TREE_VECTYPE (child))
          {