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#include <stdio.h>
unsigned int reverse_bits(unsigned int value)
{
unsigned int answer;
unsigned int i;
answer = 0;
for(i=1;i!=0;i<<=1){ //´ËÑ»·¿ÉÒÔºöÂÔ»úÆ÷µÄ²îÒì¡£64λºÍ32λ½Ô¿ÉÓã¬ÔöÇ¿´Ë´úÂëµÄ¿ÉÒÆÖ²ÐÔ
answer <<=1;
if(value & 1)
answer |= 1;
value >>=1;
}
return answer;
}
int main(void)
{
unsigned int get_answer=reverse_bits(13);
int i=31;
char t;
while(i)
{
t ='0'+ ((get_answer >> i) & 1);
printf("%c",t);
i--;
}
}
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Linux 2.6 kernelÖеÄset_bit²Ù×÷£º
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static inline void set_bit(int nr, volatile unsigned long *addr)
{
int *a = (int *)addr;
int mask;
//unsigned long flags;
a += nr >> 5;
mask = 1 << (nr & 0x1f);
//local_irq_save_hw(flags);
*a |= mask;
//local_irq_restore_hw(flags);
}
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