Compiling with GCC using -Wfloat-equal turned on, I get the following warnings:
printf.c:346:18: warning: comparing floating point with == or != is unsafe [-Wfloat-equal]
printf.c:363:20: warning: comparing floating point with == or != is unsafe [-Wfloat-equal]

The code does has a compare to 0.5

Any ideas on how to resolve this?
Thank you for creating this wonderful function!