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-rw-r--r--gcc/fold-const.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 2c90d0c..2ed556b 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -7015,6 +7015,20 @@ fold_unary (enum tree_code code, tree type, tree op0)
|| (TREE_CODE (arg0) == PLUS_EXPR
&& integer_all_onesp (TREE_OPERAND (arg0, 1)))))
return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
+ /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
+ else if (TREE_CODE (arg0) == BIT_XOR_EXPR
+ && (tem = fold_unary (BIT_NOT_EXPR, type,
+ fold_convert (type,
+ TREE_OPERAND (arg0, 0)))))
+ return fold_build2 (BIT_XOR_EXPR, type, tem,
+ fold_convert (type, TREE_OPERAND (arg0, 1)));
+ else if (TREE_CODE (arg0) == BIT_XOR_EXPR
+ && (tem = fold_unary (BIT_NOT_EXPR, type,
+ fold_convert (type,
+ TREE_OPERAND (arg0, 1)))))
+ return fold_build2 (BIT_XOR_EXPR, type,
+ fold_convert (type, TREE_OPERAND (arg0, 0)), tem);
+
return NULL_TREE;
case TRUTH_NOT_EXPR: