一段位操作代码
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//buf 数组区,pos从左到右数的位数#define TEST_ARRAY_BIT(buf,pos) (!!(buf[(pos)/8] & (1UL<<(7-((pos)%8)))))#define SET_ARRAY_BIT(buf,pos) (buf[(pos)/8] = (buf[(pos)/8] | (1UL<<(7-((pos)%8)))))//v 数值,pos从右到左数的位数#define TEST_BIT(v,pos) (!!(((unsigned long)v) & (1UL<<(pos))))//将数值v放置到buf数组第start位开始的长度为length的二进制区域内static void sn_set_bits(IN char buf[],IN int start,IN int length,IN int v){int i;for(i=0;i<length;i++){if(TEST_BIT(v,i)){SET_ARRAY_BIT(buf,start+length-i-1);}}}//获取buf数组中第start位开始的长度为length的二进制位所表示的数值static int sn_get_bits(IN char buf[],IN int start,IN int length){int i,v=0;for(i=0;i<length;i++){v += (TEST_ARRAY_BIT(buf,start+i) * (1UL<<(length-1-i)));}return v;}