  Cygnus X-1, the well-known accreting black hole system, exhibits several
observational features hinting at an intricate interplay between the accretion
disk, its atmosphere known as the corona and the putative relativistic jet. It
has been extensively studied using all available observational methods,
including using the newly available technique of sensitive X-ray polarimetry.
X-ray polarization characteristics are distinct for coronal and jet emissions.
The low X-ray polarization measured below $\sim$100 keV is understood as
arising from the corona. In contrast, the high polarization measurements
reported above $\sim$400 keV required a separate jet-dominated spectral
component, which spectroscopy does not demonstrate conclusively. Here we report
precise polarization measurements in the 100-380 keV region made during three
different sub-classes of spectral states of the source using the CZTI
instrument onboard {\em AstroSat}. A high polarization (23$\pm$4 \%) is found
mainly in the Intermediate Hard State of the source, and the energy-resolved
measurements smoothly connect the coronal and the jet regimes. When high
polarization is observed, the simultaneous spectral data hints at a separate
power law component above 100 keV. We examine the possible sources of this
energy-dependent high polarization in Cygnus X-1.
