FETCHANDN

Operation

Atomically clears memory bits selected by a source and returns the old value.

Assembler Syntax

FETCHANDN.{B|W|L|Q}(z)/order(o) Rn(s), <ea>(e)

Privilege

Unprivileged

Required CPUID flags

FETCHANDN

Atomically replaces memory with \(\mathit{oldMemory} \mathbin{\&} \lnot \mathit{source}\) and returns the old memory value in the source register. The encoded memory-order selector governs the complete operation.

2.75in

Encodings

FETCHANDN.{B|W|L|Q}(z)/order(o) Rn(s), <ea>(e)

Format: Instruction format for FETCHANDN.{B|W|L|Q}(z)/order(o) Rn(s), <ea>(e)

order — allowed: 0x0..0x4 [memory_order_reserved_reclaimed]

memory — excluded: immediate [memory_operand_required]