@Rajesh: In binary, mask = 111...100000 (with 4-byte ints, this is 27
1-bits followed by 5 0-bits). The logical product of num with mask zeros
out the low order 5 bits while retaining the high order 27 bits. Thus, res
is num truncated to the largest multiple of 32 that does not exceed num. 56
= (1*32 + 24) goes to 1*32 = 32, 64 (=2*32 + 0) stays at 2*32 = 64, and 127
(=3*32 + 31) goes to 3*32 = 96.
Dave
On Saturday, November 24, 2012 2:45:24 AM UTC-6, rajesh pandey wrote:
> void dosomething(int num)
> {
> int mask=~(1<<5-1);
> int res=num&mask;
> printf("%d",res);
> }
> int main()
> {
> dosomething(56);
> dosomething(64);
> dosomething(127);
> return 0;
> }
>
> please explain the logic behind the output.
>
> Thanks,
> Rajesh
>
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