+/* Fold a binary bitwise/truth expression of code CODE and type TYPE with
+ operands OP0 and OP1. LOC is the location of the resulting expression.
+ ARG0 and ARG1 are the NOP_STRIPed results of OP0 and OP1.
+ Return the folded expression if folding is successful. Otherwise,
+ return NULL_TREE. */
+static tree
+fold_truth_andor (location_t loc, enum tree_code code, tree type,
+ tree arg0, tree arg1, tree op0, tree op1)
+{
+ tree tem;
+
+ /* We only do these simplifications if we are optimizing. */
+ if (!optimize)
+ return NULL_TREE;
+
+ /* Check for things like (A || B) && (A || C). We can convert this
+ 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. 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_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
+ {
+ tree a00 = TREE_OPERAND (arg0, 0);
+ tree a01 = TREE_OPERAND (arg0, 1);
+ tree a10 = TREE_OPERAND (arg1, 0);
+ tree a11 = TREE_OPERAND (arg1, 1);
+ int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
+ || TREE_CODE (arg0) == TRUTH_AND_EXPR)
+ && (code == TRUTH_AND_EXPR
+ || code == TRUTH_OR_EXPR));
+
+ if (operand_equal_p (a00, a10, 0))
+ return fold_build2_loc (loc, TREE_CODE (arg0), type, a00,
+ fold_build2_loc (loc, code, type, a01, a11));
+ else if (commutative && operand_equal_p (a00, a11, 0))
+ return fold_build2_loc (loc, TREE_CODE (arg0), type, a00,
+ fold_build2_loc (loc, code, type, a01, a10));
+ else if (commutative && operand_equal_p (a01, a10, 0))
+ return fold_build2_loc (loc, TREE_CODE (arg0), type, a01,
+ fold_build2_loc (loc, code, type, a00, a11));
+
+ /* This case if tricky because we must either have commutative
+ operators or else A10 must not have side-effects. */
+
+ else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
+ && operand_equal_p (a01, a11, 0))
+ return fold_build2_loc (loc, TREE_CODE (arg0), type,
+ fold_build2_loc (loc, code, type, a00, a10),
+ a01);
+ }
+
+ /* See if we can build a range comparison. */
+ if (0 != (tem = fold_range_test (loc, code, type, op0, op1)))
+ return tem;
+
+ if ((code == TRUTH_ANDIF_EXPR && TREE_CODE (arg0) == TRUTH_ORIF_EXPR)
+ || (code == TRUTH_ORIF_EXPR && TREE_CODE (arg0) == TRUTH_ANDIF_EXPR))
+ {
+ tem = merge_truthop_with_opposite_arm (loc, arg0, arg1, true);
+ if (tem)
+ return fold_build2_loc (loc, code, type, tem, arg1);
+ }
+
+ if ((code == TRUTH_ANDIF_EXPR && TREE_CODE (arg1) == TRUTH_ORIF_EXPR)
+ || (code == TRUTH_ORIF_EXPR && TREE_CODE (arg1) == TRUTH_ANDIF_EXPR))
+ {
+ tem = merge_truthop_with_opposite_arm (loc, arg1, arg0, false);
+ if (tem)
+ return fold_build2_loc (loc, code, type, arg0, tem);
+ }
+
+ /* Check for the possibility of merging component references. If our
+ lhs is another similar operation, try to merge its rhs with our
+ rhs. Then try to merge our lhs and rhs. */
+ if (TREE_CODE (arg0) == code
+ && 0 != (tem = fold_truthop (loc, code, type,
+ TREE_OPERAND (arg0, 1), arg1)))
+ return fold_build2_loc (loc, code, type, TREE_OPERAND (arg0, 0), tem);
+
+ if ((tem = fold_truthop (loc, code, type, arg0, arg1)) != 0)
+ return tem;
+
+ return NULL_TREE;
+}
+