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| author | Damien George <damien.p.george@gmail.com> | 2015-12-08 12:28:11 +0000 |
|---|---|---|
| committer | Damien George <damien.p.george@gmail.com> | 2015-12-10 22:19:48 +0000 |
| commit | bdbe8c9ae21559f6dc0b8e1ad84b7bbec2a04726 (patch) | |
| tree | 3c603ca42bd10e7d5bbd037d85d6b57735d39393 /py/runtime.c | |
| parent | e242b1785f9e25b36f5d225652c679cd7cec6ec0 (diff) | |
py: Make UNARY_OP_NOT a first-class op, to agree with Py not semantics.
Fixes #1684 and makes "not" match Python semantics. The code is also
simplified (the separate MP_BC_NOT opcode is removed) and the patch saves
68 bytes for bare-arm/ and 52 bytes for minimal/.
Previously "not x" was implemented as !mp_unary_op(x, MP_UNARY_OP_BOOL),
so any given object only needs to implement MP_UNARY_OP_BOOL (and the VM
had a special opcode to do the ! bit).
With this patch "not x" is implemented as mp_unary_op(x, MP_UNARY_OP_NOT),
but this operation is caught at the start of mp_unary_op and dispatched as
!mp_obj_is_true(x). mp_obj_is_true has special logic to test for
truthness, and is the correct way to handle the not operation.
Diffstat (limited to 'py/runtime.c')
| -rw-r--r-- | py/runtime.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/py/runtime.c b/py/runtime.c index 58b5a5dd1..c9a56f635 100644 --- a/py/runtime.c +++ b/py/runtime.c @@ -184,7 +184,10 @@ void mp_delete_global(qstr qst) { mp_obj_t mp_unary_op(mp_uint_t op, mp_obj_t arg) { DEBUG_OP_printf("unary " UINT_FMT " %p\n", op, arg); - if (MP_OBJ_IS_SMALL_INT(arg)) { + if (op == MP_UNARY_OP_NOT) { + // "not x" is the negative of whether "x" is true per Python semantics + return mp_obj_new_bool(mp_obj_is_true(arg) == 0); + } else if (MP_OBJ_IS_SMALL_INT(arg)) { mp_int_t val = MP_OBJ_SMALL_INT_VALUE(arg); switch (op) { case MP_UNARY_OP_BOOL: |