Bit shifting internals

[Gayathri Jagannathan]

hai,
can anyone please explain the internal logic of the bit shifting operators as there are a few doubts like the bit -5<<1 why gives the resulyt of -3 when it shud give -1
this site gives few details but not the whole picture
www.jchq.net/tutorial/BitShift.htm
Thanx in advance

[Randall Twede]

dont worry too much about this. if you understand the basics of >>,<<, and >>> you will have no problem with any question about bit shifting. they dont try to trick you.

[Manfred Leonhardt]

Gayathri,
To answer your question if we shift any integer to the left once we actually double the number. Your example answers are both wrong! The answer we would expect is -10.
Here's why:
-5: 0xFFFFFFFB
1111 1111 1111 1111 1111 1111 1111 1011
<< 1: (add one zero to right side) FFFFFFF6
1111 1111 1111 1111 1111 1111 1111 0110
The final result is -10. For negatives it is easier to see value by taking twos complement and just add negative sign:
~: 0000 0000 0000 0000 0000 0000 0000 1001
+1: 0000 0000 0000 0000 0000 0000 0000 1010
0xA = 10 decimal.
Whoa,
Manfred.
[This message has been edited by Manfred Leonhardt (edited January 19, 2001).]