adr

Form PC-relative Address

ADR <Xd>, <label>

Calculates the address of a label (PC +/- 1MB range).

Details

Forms a PC-relative address by adding a signed 21-bit offset to the current PC and stores the result in the destination register. The immediate is composed of immhi (19 bits) and immlo (2 bits) and supports label references within ±1 MB. This is an AArch64-only instruction that does not affect condition flags.

Pseudocode Operation

Xd ← PC + SignExtend(immhi:immlo, 21)

Example

ADR x0, label

Encoding

Binary Layout

immlo

10000

immhi

Format PC-rel

Opcode 0x10000000

Extension Base

Operands

Xd
Destination 64-bit integer register
label
Label

Reference (Arm A64 ISA)

Instruction Forms

Encoding	Instruction	ISA	Bit pattern
0x10000000	ADR <Xd>, <label>	A64	0 \| immlo \| 10000 \| immhi \| Rd
0x04A0A000	ADR <Zd>.<T>, [<Zn>.<T>, <Zm>.<T>{, <mod> <amount>}]	A64	00000100 \| 1 \| sz \| 1 \| Zm \| 1010 \| msz \| Zn \| Zd
0x0420A000	ADR <Zd>.D, [<Zn>.D, <Zm>.D, SXTW{ <amount>}]	A64	00000100 \| 0 \| 0 \| 1 \| Zm \| 1010 \| msz \| Zn \| Zd
0x0460A000	ADR <Zd>.D, [<Zn>.D, <Zm>.D, UXTW{ <amount>}]	A64	00000100 \| 0 \| 1 \| 1 \| Zm \| 1010 \| msz \| Zn \| Zd

Description

Form PC-relative address adds an immediate value to the PC value to form a PC-relative address, and writes the result to the destination register.

Operation

X[d, 64] = PC64 + imm;