(fold, truth_andor): Disable optimization for side effects on RHS.

From-SVN: r14047

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 84e098a..45311c9 100644 (file)
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -4791,12 +4791,14 @@ fold (expr)
         to A || (B && C).  Note that either operator can be any of the four
         truth and/or operations and the transformation will still be
         valid.   Also note that we only care about order for the
-        ANDIF and ORIF operators.  */
+        ANDIF and ORIF operators.  If B contains side effects, this
+        might change the truth-value of A. */
       if (TREE_CODE (arg0) == TREE_CODE (arg1)
          && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
              || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
              || TREE_CODE (arg0) == TRUTH_AND_EXPR
-             || TREE_CODE (arg0) == TRUTH_OR_EXPR))
+             || TREE_CODE (arg0) == TRUTH_OR_EXPR)
+         && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
        {
          tree a00 = TREE_OPERAND (arg0, 0);
          tree a01 = TREE_OPERAND (arg0, 1);