11.13 ADRL pseudo-instruction

Load a PC-relative or register-relative address into a register.

Syntax

ADRL{cond} Rd,label

where:

cond

is an optional condition code.

Rd

is the register to load.

label

is a PC-relative or register-relative expression.

Usage

ADRL always assembles to two 32-bit instructions. Even if the address can be reached in a single instruction, a second, redundant instruction is produced.

If the assembler cannot construct the address in two instructions, it generates an error message and the assembly fails. You can use the LDR pseudo-instruction for loading a wider range of addresses.

ADRL is similar to the ADR instruction, except ADRL can load a wider range of addresses because it generates two data processing instructions.

ADRL produces position-independent code, because the address is PC-relative or register-relative.

If label is PC-relative, it must evaluate to an address in the same assembler area as the ADRL pseudo-instruction.

If you use ADRL to generate a target for a BX or BLX instruction, it is your responsibility to set the Thumb bit (bit 0) of the address if the target contains Thumb instructions.

Architectures and range

The available range depends on the instruction set in use:

ARM

The range of the instruction is any value that can be generated by two ADD or two SUB instructions. That is, any value that can be produced by the addition of two values, each of which is 8 bits rotated right by any even number of bits within a 32-bit word.

Thumb, 32-bit encoding

±1MB bytes to a byte, halfword, or word-aligned address.

Thumb, 16-bit encoding

ADRL is not available.

The given range is relative to a point four bytes (in Thumb code) or two words (in ARM code) after the address of the current instruction.

Note:

When assembling Thumb instructions, ADRL is only available in ARMv6T2 and later.

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