在Rust中,可以使用内建函数__builtin_clzll来计算一个64位整数的前导零位数。该函数返回一个无符号整数,表示给定整数的二进制表示中从最高位开始连续的零的个数。 要在Rust中使用__builtin_clzll,可以使用内联汇编来调用该函数。以下是一个示例代码: 代码语言:txt 复制 #[cfg(target_arch = "x86_64")]
1 __builtin_ctz( ) / __buitlin_ctzll( ) 用法:返回括号内数的二进制表示数末尾0的个数 //eg:#include<bits/stdc++.h>usingnamespacestd ;intmain(){ cout<< __builtin_ctz(8) <<endl ;return0; } 输出:3 8 = 1000 , 末尾有3个0 2 __buitlin_clz( ) / __buitlin_clzll( ) 用法:...
如果输入的值为零,__builtin_clz和__builtin_clzll的行为是未定义的。这可能会导致程序崩溃或产生不可预测的结果。 解决方法: 在使用前检查输入值是否为零,并进行相应的处理: 代码语言:txt 复制 int leading_zeros(unsigned int x) { return x == 0 ? 32 : __builtin_clz(x); } int main() { uns...
int n = 15;//⼆进制为1111 int m = 7;//111 cout<<__builtin_parity(n)<<endl;//偶数个，输出0 cout<<__builtin_parity(m)<<endl;//奇数个，输出1 此外，这些函数都有相应的usigned long和usigned long long版本，只需要在函数名后⾯加上l或ll就可以了，⽐如int __builtin_clzll。
int__builtin_clz (unsignedintx) Returns the number of leading0-bits in x, starting at the most significant bit position. If x is0, the result is undefined.int__builtin_clzl (unsignedlong) Similar to __builtin_clz, except the argument type isunsignedlong.int__builtin_clzll (unsignedlon...
cout<<__builtin_clzll(8)<<endl; return0; } 输出:60 长整型(long long)为64位,有60个前导0 3 __builtin_popcount( ) 用法:返回括号内数的二进制表示数1的个数 //eg: #include<bits/stdc++.h> usingnamespacestd; intmain(){ cout<<__builtin_popcount(15)<<endl; ...
2 __buitlin_clz( ) / __buitlin_clzll( ) 3 __builtin_popcount( ) 4 __builtin_parity( ) 5 __builtin_ffs( ) 6 __builtin_sqrt( ) 以__builtin 开头的函数,是一种相当神奇的位运算函数,下面本人盘点了一下这些以 __builtin 开头的函数,希望可以帮到大家。 1 __builtin_ctz( ) / _...
__cntlz4, __builtin_clz, __cntlz8, __builtin_clzll Purpose Count Leading Zeros, 4/8-byte integer Prototype int __builtin_clz (unsigned int); int __builtin_clzll (unsigned long long); int __cntlz4 (unsigned int); int __cntlz8 (unsigned long long);...
# __builtin_clzll # __builtin_complex # __builtin_constant_p # __builtin_ctz # __builtin_ctzl # __builtin_ctzll # __builtin_expect # __builtin_ffs # __builtin_ffsl # __builtin_ffsll # __builtin_fpclassify # __builtin_huge_val # __builtin_huge_valf # __builtin_huge...
— Built-in Function: int __builtin_clzll (unsigned long long) Similar to __builtin_clz, except the argument type is unsigned long long. — Built-in Function: int __builtin_ctzll (unsigned long long) Similar to __builtin_ctz, except the argument type is unsigned long long. ...