List of platforms supported by the C standard

Question

Does anyone know of any platforms supported by the C standard, for which there is still active development work, but which are:

• not 2\'s complement or

Answer 1

My two cents. Please don't blame hard, this is from my experience, I'm not a theoretic:

• not 2's complement

All of the existing CPU's are 2's complement

• the integer width is not 32 bits or 64 bits

There are 8 and 16 bits architectures too. 8 bit AVR MCU's is a good example.

• some integer types have padding bits

I am not aware of any system, that pads integers. Floating numbers - is a different story.

• if you worked on a 2's complement machine, the bit pattern with sign bit 1 and all value bits zero is not a valid negative number
• integer conversion from signed to unsigned (and vice versa) is not via verbatim copying of bit patterns
• right shift of integer is not arithmetic shift
• the number of value bits in an unsigned type is not the number of value bits in the corresponding signed type + 1
• conversion from a wider int type to a smaller type is not by truncation of the left most bits which would not fit

All of the above - not aware of any, and I assume there is no such machine.