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Comment by kbolino

17 hours ago

This distinction does not exist in K&R 2/e which documents ANSI C aka C89, but maybe it was added in a later version of the language (or didn't make it into the book)? According to K&R, all overflow is undefined.

I don't have my copy of K&R handy, but this distinction has existed since the initial codification. From C89:

  3.1.2.5 Types

  [...] A computation involving unsigned operands can never overflow, because a result that cannot be represented by the resulting unsigned integer type is reduced modulo the number that is one greater than the largest value that can be represented by the resulting unsigned integer type.

Source: C89 (draft) at https://port70.net/~nsz/c/c89/c89-draft.txt