Module core::core_arch::x86_64::abm

🔬This is a nightly-only experimental API. (stdsimd #48556)

Available on x86-64 only.

Advanced Bit Manipulation (ABM) instructions

The POPCNT and LZCNT have their own CPUID bits to indicate support.

The references are:

• Intel 64 and IA-32 Architectures Software Developer’s Manual Volume 2: Instruction Set Reference, A-Z.
• AMD64 Architecture Programmer’s Manual, Volume 3: General-Purpose and System Instructions.

Wikipedia provides a quick overview of the instructions available.

Functions

• _lzcnt_u64^⚠lzcnt
  Counts the leading most significant zero bits.
• _popcnt64^⚠popcnt
  Counts the bits that are set.