5.6 · exercise

Practice: Memory Addressing Syntax

Fill in the missing mnemonics, registers, or symbols to construct accurate AArch64 memory instructions.

0 of 10 correct

Load a single byte from memory into w20, zero-extending the remaining bits.

w20, [x29, 16]

Store exactly 2 bytes (a halfword) from w21 into memory.

w21, [x29, 20]

Load a 64-bit value using pre-indexed addressing, updating x20 by 10.

ldr x21, [x20, 10]

Load a 32-bit value using post-indexed addressing, moving x28 forward by 8 bytes after the load.

ldr w20, [x28] 8

Add a sign-extended 32-bit register offset (w21) to the base register (x29) during a load.

ldr x22, [x29, w21, ]

Define a macro 'a_s' with a value of 16.

(a_s, 16)

Create an assembler equate that renames register x29 to 'fp'.

fp . x29

Ensure the following machine instruction is properly 4-byte aligned.

. 4

Calculate a stack allocation of -20 bytes while forcing quadword (-16) alignment.

add sp, sp, -20 &

Set the Frame Pointer as a stable anchor at the beginning of a subroutine.

mov , sp