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one question about bit operator

one question about bit operator# JobHunting - 待字闺中

c*g2012-03-18 07:03

1 楼

what's the different between
n >> 1;
and
n >>= 1;
I am quite confused about this

d*e2012-03-18 07:03

2 楼

the second one should be like
a = n >> 1;
n = a;

【在 c***g 的大作中提到】

: what's the different between
: n >> 1;
: and
: n >>= 1;
: I am quite confused about this

z*42012-03-18 07:03

3 楼

第二个需要temporary memory？

【在 c***g 的大作中提到】

: what's the different between
: n >> 1;
: and
: n >>= 1;
: I am quite confused about this

p*i2012-03-18 07:03

4 楼

n >> 1 is an expression that does not change the value of n.
n >>= 1 is equivalent to n = n >> 1, which basically assigns the result of
the expression (n>>1) back to n
At the machine level, "n>>=1" can be a single instruction (depending the
instruction set)
n >> 1 may need temporary storage. again, these stuff heavily depend on the
architecture and the instruction set.

【在 c***g 的大作中提到】

: what's the different between
: n >> 1;
: and
: n >>= 1;
: I am quite confused about this