[05/46] Fix make_ssa_name call in vectorizable_reduction

The usual vectoriser dance to create new assignments is:

    new_stmt = gimple_build_assign (vec_dest, ...);
    new_temp = make_ssa_name (vec_dest, new_stmt);
    gimple_assign_set_lhs (new_stmt, new_temp);

but one site in vectorizable_reduction used:

    new_temp = make_ssa_name (vec_dest, new_stmt);

before creating new_stmt.

This method of creating statements probably needs cleaning up, but
that's for another day...

2018-07-31  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-vect-loop.c (vectorizable_reduction): Fix an instance in
	which make_ssa_name was called with new_stmt before new_stmt
	had been created.

From-SVN: r263120

gcc/ChangeLog

 2018-07-31  Richard Sandiford  <richard.sandiford@arm.com>
 
+	* tree-vect-loop.c (vectorizable_reduction): Fix an instance in
+	which make_ssa_name was called with new_stmt before new_stmt
+	had been created.
+
+2018-07-31  Richard Sandiford  <richard.sandiford@arm.com>
+
 	* tree-vect-loop.c (vect_valid_reduction_input_p): New function,
 	split out from...
 	(vect_is_slp_reduction): ...here...

gcc/tree-vect-loop.c

@@ -7210,9 +7210,10 @@ vectorizable_reduction (gimple *stmt, gimple_stmt_iterator *gsi,
 	      if (op_type == ternary_op)
 		vop[2] = vec_oprnds2[i];
 
-	      new_temp = make_ssa_name (vec_dest, new_stmt);
-	      new_stmt = gimple_build_assign (new_temp, code,
+	      new_stmt = gimple_build_assign (vec_dest, code,
 					      vop[0], vop[1], vop[2]);
+	      new_temp = make_ssa_name (vec_dest, new_stmt);
+	      gimple_assign_set_lhs (new_stmt, new_temp);
 	    }
 	  vect_finish_stmt_generation (stmt, new_stmt, gsi);