The ARMv6 CPU in the Pi has an FPU. Depending on your OS, you can use it in two different ways: * softfp where the float function arguments are passed in using

The ARMv6 CPU in the Pi has an FPU. Depending on your OS, you can use it in two different ways: * softfp where the float function arguments are passed in using integer registers or the stack * hardfp where they are passed in using the FPU registers In the above cases, the float operations are done in hardware in the FPU. There is a 3rd ABI called softfloat where everything is done in software, and thus is very slow.