1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
//! tzcnt
/// Counts trailing zero bits
pub trait Tzcnt {
/// Counts the number of trailing least significant zero bits.
///
/// When the source operand is 0, it returns its size in bits.
///
/// This is equivalent to searching for the least significant set bit and
/// returning its index.
///
/// **Keywords**: Count trailing zeros, Bit scan forward, find first set.
///
/// # Instructions
///
/// - [`TZCNT`](http://www.felixcloutier.com/x86/TZCNT.html):
/// - Description: Count the number of trailing zero bits.
/// - Architecture: x86.
/// - Instruction set: BMI.
/// - Registers: 16/32/64 bit.
///
/// # Example
///
/// ```
/// # use bitintr::*;
/// assert_eq!(0b1001_0000_u16.tzcnt(), 4_u16);
/// assert_eq!(0b0000_0000_u32.tzcnt(), 32_u32);
/// assert_eq!(0b0000_0001_u64.tzcnt(), 0_u64);
/// ```
fn tzcnt(self) -> Self;
}
macro_rules! impl_tzcnt {
($id:ident) => {
impl Tzcnt for $id {
#[inline]
fn tzcnt(self) -> Self {
self.trailing_zeros() as Self
}
}
};
}
impl_all!(impl_tzcnt: u8, u16, u32, u64, i8, i16, i32, i64);