VCTZ

Operation

Counts consecutive zero bits from the low end of each active element.

Assembler Syntax

VCTZ.{B|W|L|Q}(z) Pn(p), Vn(v)

VCTZ.{B|W|L|Q}(z) Pn(p), <ea>(e), Vn(v)

VCTZ.{B|W|L|Q}(z) Pn(p), Vn(v), <ea>(e)

Privilege

Unprivileged

Required CPUID flags

VECTOR

The register form replaces each active destination lane with the count of consecutive zero bits at the low end of its old selected-width value. The memory-source form counts trailing zero bits in each active memory element and writes the result to the corresponding destination lane. An inactive destination lane retains its previous value.

The memory-destination form counts trailing zero bits in each active source-register lane and writes the result to the corresponding memory element. An inactive memory element remains unchanged. If every bit in an element is zero, the result equals the element width in bits.

2.75in

Encodings

VCTZ.{B|W|L|Q}(z) Pn(p), Vn(v)

Format: Instruction format for VCTZ.{B|W|L|Q}(z) Pn(p), Vn(v)

2.75in VCTZ.{B|W|L|Q}(z) Pn(p), <ea>(e), Vn(v)

Format: Instruction format for VCTZ.{B|W|L|Q}(z) Pn(p), <ea>(e), Vn(v)

2.75in VCTZ.{B|W|L|Q}(z) Pn(p), Vn(v), <ea>(e)

Format: Instruction format for VCTZ.{B|W|L|Q}(z) Pn(p), Vn(v), <ea>(e)

dst — excluded: immediate [invalid_destination]