Clean up dead condition for operators in DCE.

2019-08-15  Martin Liska  <mliska@suse.cz>

	* tree-ssa-dce.c (propagate_necessity): We can't reach now
	operators with no arguments.
	(eliminate_unnecessary_stmts): Likewise here.

From-SVN: r274529

gcc/ChangeLog

+2019-08-15  Martin Liska  <mliska@suse.cz>
+
+	* tree-ssa-dce.c (propagate_necessity): We can't reach now
+	operators with no arguments.
+	(eliminate_unnecessary_stmts): Likewise here.
+
 2019-08-15  Uroš Bizjak  <ubizjak@gmail.com>
 
 	* config/i386/i386-features.c (general_scalar_chain::convert_insn)

gcc/tree-ssa-dce.c

@@ -810,11 +810,6 @@ propagate_necessity (bool aggressive)
 	  if (is_delete_operator
 	      || gimple_call_builtin_p (stmt, BUILT_IN_FREE))
 	    {
-	      /* It can happen that a user delete operator has the pointer
-		 argument optimized out already.  */
-	      if (gimple_call_num_args (stmt) == 0)
-		continue;
-
 	      tree ptr = gimple_call_arg (stmt, 0);
 	      gimple *def_stmt;
 	      tree def_callee;
@@ -1328,18 +1323,13 @@ eliminate_unnecessary_stmts (void)
 		  || (is_gimple_call (stmt)
 		      && gimple_call_operator_delete_p (as_a <gcall *> (stmt)))))
 	    {
-	      /* It can happen that a user delete operator has the pointer
-		 argument optimized out already.  */
-	      if (gimple_call_num_args (stmt) > 0)
+	      tree ptr = gimple_call_arg (stmt, 0);
+	      if (TREE_CODE (ptr) == SSA_NAME)
 		{
-		  tree ptr = gimple_call_arg (stmt, 0);
-		  if (TREE_CODE (ptr) == SSA_NAME)
-		    {
-		      gimple *def_stmt = SSA_NAME_DEF_STMT (ptr);
-		      if (!gimple_nop_p (def_stmt)
-			  && !gimple_plf (def_stmt, STMT_NECESSARY))
-			gimple_set_plf (stmt, STMT_NECESSARY, false);
-		    }
+		  gimple *def_stmt = SSA_NAME_DEF_STMT (ptr);
+		  if (!gimple_nop_p (def_stmt)
+		      && !gimple_plf (def_stmt, STMT_NECESSARY))
+		    gimple_set_plf (stmt, STMT_NECESSARY, false);
 		}
 	    }