With a sense resistor of 0 ohms, the IC switch current limit will limit peak *input* current to between 1.5 and 2.8A with a typical of 2.1A. These are the datasheet min/max/typ values. Output current will be less, determined by the Vin/Vout ratio and circuit efficiency. Efficiency will be pretty good with Vin close to Vout and fairly low with Vin small relative to Vout.