ctz

CTZ <Wd>, <Wn>

Count Trailing Zeros.

Pseudocode Operation

No pseudocode available.

Encoding

Binary Layout

11010110

28:21

00000

20:16

000110

15:10

9:5

4:0

Format CSSC

Opcode 0x5AC01800

Extension CSSC

Reference

View in Arm A64 ISA Reference ↗ Arm A64 ISA

Instruction Forms

Encoding	Instruction		ISA		Bit pattern
0x5AC01800	CTZ <Wd>, <Wn>		A64		0 \| 1 \| 0 \| 11010110 \| 00000 \| 000110 \| Rn \| Rd
0xDAC01800	CTZ <Xd>, <Xn>		A64		1 \| 1 \| 0 \| 11010110 \| 00000 \| 000110 \| Rn \| Rd

Description

Count Trailing Zeros counts the number of consecutive binary zero bits, starting from the least significant bit in the source register, and places the count in the destination register.

Operation

bits(datasize) operand1 = X[n, datasize];
integer result = CountLeadingZeroBits(BitReverse(operand1));
X[d, datasize] = result<datasize-1:0>;

ctz