adr

Form PC-relative Address (Thumb)

ADR <Rd>, <label>

Adds an immediate value to the PC (Thumb).

Pseudocode Operation

Rd ← Align(PC, 4) + (imm8 << 2)

Example

ADR r0, label

Encoding

Binary Layout

1010

15:12

10:8

imm8

7:0

Format Thumb Data Proc

Opcode 0xA000

Extension T32 (Thumb)

Operands

Rd
Destination general-purpose register
label
Label

Other forms of adr

adr Form PC-relative Address
adr Form PC-relative Address (A32)

Reference

View in Arm A64 ISA Reference ↗ Arm AArch32 ISA

Instruction Forms

Encoding	Instruction	ISA	Bit pattern
0x028F0000	ADR{<c>}{<q>} <Rd>, <label>	A32	cond \| 0010 \| 100 \| 0 \| 1111 \| Rd \| imm12
0x024F0000	ADR{<c>}{<q>} <Rd>, <label>	A32	cond \| 0010 \| 010 \| 0 \| 1111 \| Rd \| imm12
0xA000	ADR{<c>}{<q>} <Rd>, <label>	T32	1010 \| 0 \| Rd \| imm8
0xF2AF0000	ADR{<c>}{<q>} <Rd>, <label>	T32	11110 \| i \| 10 \| 1 \| 0 \| 1 \| 0 \| 1111 \| 0 \| imm3 \| Rd \| imm8
0xF20F0000	ADR{<c>}.W <Rd>, <label>	T32	11110 \| i \| 10 \| 0 \| 0 \| 0 \| 0 \| 1111 \| 0 \| imm3 \| Rd \| imm8

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

if ConditionPassed() then
    EncodingSpecificOperations();
    result = if add then (Align(PC,4) + imm32) else (Align(PC,4) - imm32);
    if d == 15 then          // Can only occur for A32 encodings
        ALUWritePC(result);
    else
        R[d] = result;

adr