-7 >> 1 It turns out -4.
It was 1000 0111 , moved to the right. Like it should turn out 1000 0011 . How did it happen that it turned out 1000 0100 ? What did I miss?
For simplicity, let it be byte .
Oleg Oleg
1,103 five sixteen
- 2And why did you decide that -7 is exactly what is written down?) Read about the additional code. - pavel
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1 answer
Actually, -7 in the additional code will be not 1000 0111 , but 1111 1001 . After a shift to the right, 1111 1100 obtained, which is equal to -4. That's right, the computer was not wrong.
PS be careful with such shifts. In C ++, they give UB.
Pavel Mayorov Pavel Mayorov
48.9k five 50 110
- The question now is why the sign bit multiplies and how to avoid it. - pavel
- And what exactly is UB here? - Flowneee
- @Flowneee bit shift according to the standard only in unsigned apply. - pavel
- @Flowneee negative number shift - Pavel Mayorov
- @PavelMayorov and pavel thank you (sorry you can’t normally have 2 participants put in the message normally) - Flowneee
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