Trait bitintr::Lzcnt [−] [src]

pub trait Lzcnt {
    fn clz(self) -> Self;

    fn lzcnt(self) -> Self;
}

Count leading zeros

Required Methods

Count Leading Zeros.

See lzcnt.

Counts the leading most significant zero bits.

When the operand is zero, it returns its size in bits.

Keywords: Leading Zeros Count, Count Leading Zeros, Bit Scan Severse, Find Last Set.

See also arm::v7::clz.

Instructions

  • LZCNT:

    • Description: Count the number of leading zero bits.
    • Architecture: x86.
    • Instruction set: ABM, BMI.
    • Registers: 16/32/64 bit.

  • Note: This instruction is officially part of BMI1 but Intel (and AMD) CPUs advertise it as being part of ABM.

  • CLZ:

    • Description: Count Leading Zeros.
    • Architecture: ARM.
    • Instruction set: v7.
    • Registers: 8/16/32 bit.

Example

assert_eq!(0b0101_1010u16.clz(), 9u16);
assert_eq!(0b0101_1010u16.lzcnt(), 9u16);

Implementors