common.opt (flag_evaluation_order): Remove.

2016-11-09  Richard Biener  <rguenther@suse.de>

	* common.opt (flag_evaluation_order): Remove.
	* expr.c (expand_operands): Remove code guarded by
	flag_evaluation_order.
	* fold-const.c (reorder_operands_p): Remove, it always returns
	true.
	(negate_expr_p): Remove calls to reorder_operands_p.
	(fold_negate_expr): Likewise.
	(tree_swap_operands_p): Likewise.
	(fold_binary_loc): Likewise.

From-SVN: r241998

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7c94651..cfdf5a5 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,15 @@
+2016-11-09  Richard Biener  <rguenther@suse.de>
+
+       * common.opt (flag_evaluation_order): Remove.
+       * expr.c (expand_operands): Remove code guarded by
+       flag_evaluation_order.
+       * fold-const.c (reorder_operands_p): Remove, it always returns
+       true.
+       (negate_expr_p): Remove calls to reorder_operands_p.
+       (fold_negate_expr): Likewise.
+       (tree_swap_operands_p): Likewise.
+       (fold_binary_loc): Likewise.
+
 2016-11-09  Andreas Schwab  <schwab@suse.de>
 
        PR target/78254

diff --git a/gcc/common.opt b/gcc/common.opt
index a60bebf..314145a 100644 (file)
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -58,10 +58,6 @@ int flag_incremental_link = 0
 Variable
 int flag_complex_method = 1
 
-; Nonzero if subexpressions must be evaluated from left-to-right.
-Variable
-int flag_evaluation_order = 0
-
 ; Language specific warning pass for unused results.
 Variable
 bool flag_warn_unused_result = false

diff --git a/gcc/expr.c b/gcc/expr.c
index e925fca..0b0946d 100644 (file)
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -7681,10 +7681,6 @@ 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);
     }

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 603aff0..b78b6d8 100644 (file)
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -133,7 +133,6 @@ static tree fold_binary_op_with_conditional_arg (location_t,
                                                 tree, tree,
                                                 tree, tree, int);
 static tree fold_div_compare (location_t, enum tree_code, tree, tree, tree);
-static bool reorder_operands_p (const_tree, const_tree);
 static tree fold_negate_const (tree, tree);
 static tree fold_not_const (const_tree, tree);
 static tree fold_relational_const (enum tree_code, tree, tree, tree);
@@ -435,9 +434,7 @@ negate_expr_p (tree t)
              && ! TYPE_OVERFLOW_WRAPS (type)))
        return false;
       /* -(A + B) -> (-B) - A.  */
-      if (negate_expr_p (TREE_OPERAND (t, 1))
-         && reorder_operands_p (TREE_OPERAND (t, 0),
-                                TREE_OPERAND (t, 1)))
+      if (negate_expr_p (TREE_OPERAND (t, 1)))
        return true;
       /* -(A + B) -> (-A) - B.  */
       return negate_expr_p (TREE_OPERAND (t, 0));
@@ -447,9 +444,7 @@ negate_expr_p (tree t)
       return !HONOR_SIGN_DEPENDENT_ROUNDING (element_mode (type))
             && !HONOR_SIGNED_ZEROS (element_mode (type))
             && (! INTEGRAL_TYPE_P (type)
-                || TYPE_OVERFLOW_WRAPS (type))
-            && reorder_operands_p (TREE_OPERAND (t, 0),
-                                   TREE_OPERAND (t, 1));
+                || TYPE_OVERFLOW_WRAPS (type));
 
     case MULT_EXPR:
       if (TYPE_UNSIGNED (type))
@@ -606,9 +601,7 @@ fold_negate_expr (location_t loc, tree t)
          && !HONOR_SIGNED_ZEROS (element_mode (type)))
        {
          /* -(A + B) -> (-B) - A.  */
-         if (negate_expr_p (TREE_OPERAND (t, 1))
-             && reorder_operands_p (TREE_OPERAND (t, 0),
-                                    TREE_OPERAND (t, 1)))
+         if (negate_expr_p (TREE_OPERAND (t, 1)))
            {
              tem = negate_expr (TREE_OPERAND (t, 1));
              return fold_build2_loc (loc, MINUS_EXPR, type,
@@ -628,8 +621,7 @@ fold_negate_expr (location_t loc, tree t)
     case MINUS_EXPR:
       /* - (A - B) -> B - A  */
       if (!HONOR_SIGN_DEPENDENT_ROUNDING (element_mode (type))
-         && !HONOR_SIGNED_ZEROS (element_mode (type))
-         && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
+         && !HONOR_SIGNED_ZEROS (element_mode (type)))
        return fold_build2_loc (loc, MINUS_EXPR, type,
                            TREE_OPERAND (t, 1), TREE_OPERAND (t, 0));
       break;
@@ -6761,27 +6753,12 @@ fold_single_bit_test (location_t loc, enum tree_code code,
   return NULL_TREE;
 }
 
-/* Check whether we are allowed to reorder operands arg0 and arg1,
-   such that the evaluation of arg1 occurs before arg0.  */
-
-static bool
-reorder_operands_p (const_tree arg0, const_tree arg1)
-{
-  if (! flag_evaluation_order)
-      return true;
-  if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
-    return true;
-  return ! TREE_SIDE_EFFECTS (arg0)
-        && ! TREE_SIDE_EFFECTS (arg1);
-}
-
 /* Test whether it is preferable two swap two operands, ARG0 and
    ARG1, for example because ARG0 is an integer constant and ARG1
-   isn't.  If REORDER is true, only recommend swapping if we can
-   evaluate the operands in reverse order.  */
+   isn't.  */
 
 bool
-tree_swap_operands_p (const_tree arg0, const_tree arg1, bool reorder)
+tree_swap_operands_p (const_tree arg0, const_tree arg1, bool)
 {
   if (CONSTANT_CLASS_P (arg1))
     return 0;
@@ -6796,10 +6773,6 @@ tree_swap_operands_p (const_tree arg0, const_tree arg1, bool reorder)
   if (TREE_CONSTANT (arg0))
     return 1;
 
-  if (reorder && flag_evaluation_order
-      && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
-    return 0;
-
   /* It is preferable to swap two SSA_NAME to ensure a canonical form
      for commutative and comparison operators.  Ensuring a canonical
      form allows the optimizers to find additional redundancies without
@@ -9224,8 +9197,7 @@ fold_binary_loc (location_t loc,
          return build2_loc (loc, COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
                             tem);
        }
-      if (TREE_CODE (arg1) == COMPOUND_EXPR
-         && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
+      if (TREE_CODE (arg1) == COMPOUND_EXPR)
        {
          tem = fold_build2_loc (loc, code, type, op0,
                             fold_convert_loc (loc, TREE_TYPE (op1),
@@ -9714,8 +9686,7 @@ fold_binary_loc (location_t loc,
     case MINUS_EXPR:
       /* (-A) - B -> (-B) - A  where B is easily negated and we can swap.  */
       if (TREE_CODE (arg0) == NEGATE_EXPR
-         && negate_expr_p (op1)
-         && reorder_operands_p (arg0, arg1))
+         && negate_expr_p (op1))
        return fold_build2_loc (loc, MINUS_EXPR, type,
                                negate_expr (op1),
                                fold_convert_loc (loc, type,