py/modbuiltins: Implement abs() by dispatching to MP_UNARY_OP_ABS.

This allows user classes to implement __abs__ special method, and saves
code size (104 bytes for x86_64), even though during refactor, an issue
was fixed and few optimizations were made:

* abs() of minimum (negative) small int value is calculated properly.
* objint_longlong and objint_mpz avoid allocating new object is the
  argument is already non-negative.

1 files changed, 5 insertions, 0 deletions

diff --git a/py/objcomplex.c b/py/objcomplex.c
index 07b9d5d41..e7a3c244a 100644
--- a/py/objcomplex.c
+++ b/py/objcomplex.c
@@ -124,6 +124,11 @@ STATIC mp_obj_t complex_unary_op(mp_unary_op_t op, mp_obj_t o_in) {
         case MP_UNARY_OP_HASH: return MP_OBJ_NEW_SMALL_INT(mp_float_hash(o->real) ^ mp_float_hash(o->imag));
         case MP_UNARY_OP_POSITIVE: return o_in;
         case MP_UNARY_OP_NEGATIVE: return mp_obj_new_complex(-o->real, -o->imag);
+        case MP_UNARY_OP_ABS: {
+            mp_float_t real, imag;
+            mp_obj_complex_get(o_in, &real, &imag);
+            return mp_obj_new_float(MICROPY_FLOAT_C_FUN(sqrt)(real*real + imag*imag));
+        }
         default: return MP_OBJ_NULL; // op not supported
     }
 }