[gcc r14-2039] Optimize vector codegen for invariant loads, fix SLP support

[Richard Biener <rguenth@gcc.gnu.org>]

https://gcc.gnu.org/g:efc7fadff587b675552cd130cffe8c96c0feb4fc

commit r14-2039-gefc7fadff587b675552cd130cffe8c96c0feb4fc
Author: Richard Biener <rguenther@suse.de>
Date:   Fri Jun 23 09:28:34 2023 +0200

    Optimize vector codegen for invariant loads, fix SLP support
    
    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.
    
            * tree-vect-stmts.cc (vectorizable_load): Avoid useless
            copies of VMAT_INVARIANT vectorized stmts, fix SLP support.

Diff:
---
 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 9e046ced7c6..e6649789540 100644
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -9593,27 +9593,26 @@ 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;
     }