Strange float behaviour on Arduino Mega

[robtillaart]

@GolamMostafa

MEGA has no floating point co-processor. Then, is it the IDE/Compiler or the board that maps the given float number into binary32 format?

IIRC the compiler does handle the compile time (float) constants to appropriate value. For the remaining it is the AVR floating point library that does the math.
(math.h)