* toplev.c (flag_evaluation_order): New global variable.

	* flags.h (flag_evaluation_order): Prototype here.
	* expr.c (expand_operands): If we need to preserve observable
	evaluation order, protect exp1 from clobbering exp0's result.

	* java/lang.c (java_init_options): Set flag_evaluation_order.
	* java/expr.c (force_evaluation_order): Don't attempt to force
	evaluation order of binary operations using save_expr.
	* java/parse.y (java_complete_lhs): No longer need to call
	force_evaluation_order when constructing binary operators.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@71873 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 4 insertions, 0 deletions

diff --git a/gcc/expr.c b/gcc/expr.c
index 6ad93c506ab..26eaab01452 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -6553,6 +6553,10 @@ expand_operands (tree exp0, tree exp1, rtx target, rtx *op0, rtx *op1,
     }
   else
     {
+      /* If we need to preserve evaluation order, copy exp0 into its own
+	 temporary variable so that it can't be clobbered by exp1.  */
+      if (flag_evaluation_order && TREE_SIDE_EFFECTS (exp1))
+	exp0 = save_expr (exp0);
       *op0 = expand_expr (exp0, target, VOIDmode, modifier);
       *op1 = expand_expr (exp1, NULL_RTX, VOIDmode, modifier);
     }