Whether evaluating that expression results in undefined behaviour also depends on the basic execution character set and the bit width of the machine byte.
I worked with some MCUs whose only redeeming quality was their cost that had CHAR_BIT=16. The answer is basically everything. It made string processing was profoundly annoying, even for C.
No, it was with xap [1] chips. TI is also on my list of annoying chip vendors because they're one of the few companies still making big endian ARM chips, which should die in a fire.
