  Exploring diverse planetary atmospheres requires modeling tools that are both
accurate and flexible. Here, we develop a three-dimensional general circulation
model (3D GCM) that for the first time uses a line-by-line approach to describe
the radiative transfer. We validate our GCM by comparing with published results
done by different 1D and 3D models. To demonstrate the versatility of the
model, we apply the GCM to the hot Earth-sized exoplanet GJ 1132b and study its
climate and circulation assuming an atmosphere dominated by abiotic oxygen
(O$_2$). Our simulations show that a minor CO$_2$ composition can change the
circulation pattern substantially, intensifying the equatorial superrotation in
particular. Computation of the phase-resolved spectroscopy indicates that the
vertical profile of the superrotating jet could be inferred in future
spectro-photometric observations by the phase shift of the hotspot in the
CO$_2$ principle absorption band centered at 667 cm$^{-1}$. We also show that
atmospheric mass could potentially be constrained by the phase amplitude in the
O$_2$ vibrational fundamental band for planets with O$_2$-rich atmospheres,
although further experimental and/or theoretical O$_2$-O$_2$ collision-induced
absorption data at high temperatures is needed to confirm this. More physical
schemes such as moist dynamics will be implemented in the GCM in the future so
that it can be used to tackle a wide variety of planetary climate problems.
