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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 2d750f6..962ebd3 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -8839,6 +8839,13 @@ fold_binary (enum tree_code code, tree type, tree op0, tree op1) /* If one arg is a real or integer constant, put it last. */ if (tree_swap_operands_p (arg0, arg1, true)) return fold_build2 (swap_tree_comparison (code), type, op1, op0); + + /* ~a != C becomes a != ~C where C is a constant. Likewise for ==. */ + if (TREE_CODE (arg0) == BIT_NOT_EXPR && TREE_CODE (arg1) == INTEGER_CST + && (code == NE_EXPR || code == EQ_EXPR)) + return fold_build2 (code, type, TREE_OPERAND (arg0, 0), + fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), + arg1)); /* bool_var != 0 becomes bool_var. */ if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1) |