[PATCH] Optimize vector codegen for invariant loads, fix SLP support

[Richard Biener via Gcc-patches]

The following avoids creating duplicate stmts for invariant loads
which was necessary when the vector stmts were in a linked list.
It also fixes SLP support which didn't correctly create the
appropriate number of copies.

Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.

        * tree-vect-stmts.cc (vectorizable_load): Avoid useless
        copies of VMAT_INVARIANT vectorized stmts, fix SLP support.
---
 gcc/tree-vect-stmts.cc | 39 +++++++++++++++++++--------------------
 1 file changed, 19 insertions(+), 20 deletions(-)

diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index 1b160cecfce..b1b08238dc3 100644
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -9612,27 +9612,26 @@ vectorizable_load (vec_info *vinfo,
          gimple_set_vuse (new_stmt, vuse);
          gsi_insert_on_edge_immediate (pe, new_stmt);
        }
-      /* These copies are all equivalent, but currently the representation
-        requires a separate STMT_VINFO_VEC_STMT for each one.  */
-      gimple_stmt_iterator gsi2 = *gsi;
-      gsi_next (&gsi2);
-      for (j = 0; j < ncopies; j++)
+      /* These copies are all equivalent.  */
+      if (hoist_p)
+       new_temp = vect_init_vector (vinfo, stmt_info, scalar_dest,
+                                    vectype, NULL);
+      else
        {
-         if (hoist_p)
-           new_temp = vect_init_vector (vinfo, stmt_info, scalar_dest,
-                                        vectype, NULL);
-         else
-           new_temp = vect_init_vector (vinfo, stmt_info, scalar_dest,
-                                        vectype, &gsi2);
-         gimple *new_stmt = SSA_NAME_DEF_STMT (new_temp);
-         if (slp)
-           SLP_TREE_VEC_STMTS (slp_node).quick_push (new_stmt);
-         else
-           {
-             if (j == 0)
-               *vec_stmt = new_stmt;
-             STMT_VINFO_VEC_STMTS (stmt_info).safe_push (new_stmt);
-           }
+         gimple_stmt_iterator gsi2 = *gsi;
+         gsi_next (&gsi2);
+         new_temp = vect_init_vector (vinfo, stmt_info, scalar_dest,
+                                      vectype, &gsi2);
+       }
+      gimple *new_stmt = SSA_NAME_DEF_STMT (new_temp);
+      if (slp)
+       for (j = 0; j < (int) SLP_TREE_NUMBER_OF_VEC_STMTS (slp_node); ++j)
+         SLP_TREE_VEC_STMTS (slp_node).quick_push (new_stmt);
+      else
+       {
+         for (j = 0; j < ncopies; ++j)
+           STMT_VINFO_VEC_STMTS (stmt_info).safe_push (new_stmt);
+         *vec_stmt = new_stmt;
        }
       return true;
     }
-- 
2.35.3