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Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 4f384a75344..7e619d6d1e5 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -821,6 +821,13 @@ split_tree (tree in, enum tree_code code, tree *conp, tree *litp, if (neg_var_p) var = negate_expr (var); } + else if (TREE_CODE (in) == BIT_NOT_EXPR + && code == PLUS_EXPR) + { + /* -X - 1 is folded to ~X, undo that here. */ + *minus_litp = build_one_cst (TREE_TYPE (in)); + var = negate_expr (TREE_OPERAND (in, 0)); + } else if (TREE_CONSTANT (in)) *conp = in; else |