CLS

Operation

Counts leading one bits in the selected-width source and writes the count.

Assembler Syntax

CLS.{B|W|L|Q}(z) <ea>(e), Rn(d)

CLS.{B|W|L|Q}(z) Rn(s), Rn(d)

Privilege

Unprivileged

Repeat eligibility

REP eligible; REPcc observes dst

Counts the leading one bits within the selected operand size and writes the count to the destination register. A zero operand returns 0; an operand whose selected bits are all one returns the operand width in bits.

2.75in

Encodings

CLS.{B|W|L|Q}(z) <ea>(e), Rn(d)

Format: Instruction format for CLS.{B|W|L|Q}(z) <ea>(e), Rn(d)

2.75in CLS.{B|W|L|Q}(z) Rn(s), Rn(d)

Format: Instruction format for CLS.{B|W|L|Q}(z) Rn(s), Rn(d)