Difference between signed and unsigned on bitwise operations
bit-manipulation, bitwise-operators, signed, unsigned
Solution
Assuming 2's complement is used for signed numbers, operations that care about signedness (ie they are different for the signed and unsigned interpretation of a bitstring) are:
- division
- modulo
- right shift
- comparisons (except equality)
- double-width multiplication (rare outside of assembly)
Operations for which signedness is irrelevant are:
- addition
- subtraction
- negation (`-x` means `~x + 1`)
- bitwise and
- bitwise or
- bitwise xor
- bitwise not (`~x` means `-x - 1`)
- left shift
- multiplication
- comparison (equality only)
Problem
Is there any difference between signed and unsigned variables on bitwise operations? For example,when dealing with unsigned numbers: `AND 00000111, 00001101` will result 00000101. But what would happen when dealing with signed numbers?