In low level there is no float or int. All data are stored in consecutive bytes. Are you asking if yout uC performs 32 bit floating operations? Then it will not as it is a 8-bit uC.
Yes. The float operations are performed by the Keil float library, using standard 8-bit 8051 instructions. The float library can run on any 8051 processor, provided it has sufficient code and data memory.